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The present invention is related to a new and useful composition of matter comprising a polyisocyanate in conjunction with triacetin or triethylcitrate. It further comprises cellulosic products impregnated with the composition and the method of their preparation and use.
BACKGROUND OF THE INVENTION
Various paper and similar products have been impregnated with polyisocyanates for uses which include decorative paneling and structural skins of products such as foam or honeycomb filled sandwich panels. Hunter, in U.S. Pat. No 5,008,359, describes one method of making such products. A sheeted cellulosic paper, such as kraft linerboard, is at least partially impregnated with an essentially uncatalyzed polyfunctional isocyanate. Normally several sheets so impregnated would be superposed and subsequently cured in a press under heat and considerable pressure to form thin panels. Use of any customary catalysts was avoided since they appeared to cause poor adhesion between various plies of the laminates. Preferred pressing temperatures are in excess of 150° C. with pressures of 3000 kPa or greater. Poly(diphenylmethane diisocyanate) (PMDI) appeared to be preferred as the impregnant.
Hunter et al., in U.S. Pat. No. 5,140,086 describe an apparent improvement on the above process. In order to achieve better and more uniform impregnation of the cellulosic substrate the isocyanate is applied in admixture with a miscible organic solvent. Propylene carbonate is the preferred solvent. This was chosen because of its low toxicity, viscosity and vapor pressure at room temperature, its high boiling point of 242° C., and because it is substantially odorless and colorless. A high boiling point material was desirable to prevent blistering during the heat curing operation. In addition to improving impregnation uniformity, propylene carbonate used in a range of 5-20%, gave improved physical properties. It was speculated that the propylene carbonate also may serve as a copolymerizable reactant to some extent. Curing of the product was done under conditions of heat and pressure similar to those described above. However, in the present case it was permissible to include up to 0.5% of a catalyst with the isocyanate-solvent mixture to accelerate the curing reaction.
A later patent to the same inventors, U.S. Pat. No. 5,280,097, is directed to making laminated panel materials in which the earlier products and methods are used as substrates for decorative overlays. The overlay, such as a melamine resin treated printed paper, could be applied to the isocyanate treated substrate or to a laminate formed from a number of substrate plies. These were then preferably cured simultaneously in a single pressing step.
Dimakis, in U.S. Pat. Nos. 5,220,760 and 5,345,738, describes foam filled structural panels made using skins of kraft paper impregnated as taught in one of the above patents.
All of the above noted methods and products require the use of extremely expensive presses for curing the product. However, it has been known that polyisocyanates impregnated into cellulosic substrates will cure to insoluble polymers over prolonged periods of time at ambient conditions. This is believed to be due to slow reaction with the natural moisture present in the substrate, with atmospheric moisture, and possibly by reaction with hydroxyl groups of the cellulosic substrate. PMDI is generally the isocyanate of choice. Wallick, in U.S. Pat. Nos. 5,292,391 and 5,332,458 teaches application of a material such as PMDI to corrugated medium for strength enhancement of corrugated container board without adversely affecting repulpability of the product. The preferred procedure is to apply the isocyanate by spraying after corrugation but prior to application of adhesive at the single facer of the corrugator. Heat curing is thereafter minimized to enhance repulpability. Curing of the isocyanate impregnant continued well after application of the second liner to the product.
PMDI is composed of a wide range of oligomers and varying amounts, typically 40-60% of monomeric 4,4'-diphenylmethane diisocyanate (MDI). As the curing reaction with water occurs under ambient conditions an intermediate reaction product is 4,4'-diaminodiphenylmethane (MDA). This, in turn, again reacts with available --NCO groups to ultimately form insoluble polyureas. MDA is a relatively toxic chemical and it is desirable that its content, as well as the content of residual unreacted MDI, should be as low as possible. Thus it is highly desirable that cure rates should be relatively rapid and that the curing reaction of the PMDI should approach completion with a minimum of unreacted products. If suitably rapid cure rates could be achieved under ambient conditions numerous applications of the polymer impregnated product would present themselves. In the case of flat panels, elimination of the hot pressing step would considerably reduce the cost. The present invention teaches how to achieve such a product by the use of a new composition of matter for impregnating the substrate material.
SUMMARY OF THE INVENTION
The present invention is directed to a new and useful composition of matter which comprises a polyfunctional isocyanate and from 1-20% by weight of triacetin (glyceryl triacetate), triethyl citrate, or mixtures of these two materials. The invention is further directed to a method of impregnating cellulosic fiber products with the composition and to the products so formed. A further aspect of the invention is a corrugated board product formed with at least one of the linerboards or the corrugated medium being treated with the composition. The isocyanate in the treated products will cure to insoluble polyureas without the inclusion of catalysts and under ambient conditions in times as short as two to four days. Quite unexpectedly, inclusion of the triacetin or triethyl citrate with the isocyanate will rapidly reduce undesirable unreacted products such as MDI and MDA to very low levels in the cured treated fiber products.
Triacetin is a particularly desirable product since it is relatively inexpensive and its toxicity is so low that it is an approved food additive.
The actual part that triacetin or triethyl citrate plays in the curing reaction of the polyisocyanate is not well understood. There is no certainty of significant coreaction between these compounds and the polyisocyanate under the conditions employed. Isocyanates are known to be highly reactive with hydroxyl containing compounds, such as water or primary alcohols. This is not the case with esters or tertiary alcohols such as those of the present invention. PMDI, the preferred polyisocyanate of the present invention, is highly hydrophobic at room temperature. While some reaction does occur when it is in direct contact with water at ambient conditions this reaction is slow and largely limited to the immediate interfacial zone at points of contact. The lack of reactivity is undoubtedly due to the phase separation that occurs and to the resulting poor contact between the liquids. The work of Hunter et al., described in U.S. Pat. No. 5,140,086, attempted to deal with problem by dilution of the PMDI with a solvent that would be mutually compatible with the fiber surface and the isocyanate. The hope was that better fiber wetting should occur with an increase in availability of the moisture within the fiber to the isocyanate as well as better accessibility to hydroxyl groups on the fiber surface. The reasoning was apparently sound since an increase in product physical properties and cure rates was noted. Even so, the improvement was not of large magnitude. When room temperature cures were attempted considerable amounts of MDI and MDA persisted for long periods of time.
Whatever their mode of function, the present inventors have found that triacetin and triethyl citrate, used in conjunction with the polyisocyanate for impregnating cellulosic fiber products, have very significantly and unexpectedly improved cure rates at ambient conditions and greatly reduced the presence and persistence of MDI and MDA. Why these specific compounds perform in superior fashion to other chemically closely related materials is not well understood. While the reason for this is unclear, triacetin and apparently triethyl citrate as well significantly increase the reaction rate of the polyisocyanate with water. Additionally, cellulosic fiber sheets impregnated with 5-30%, preferably 8-20%, of the mixture show improved physical properties at levels that have hot heretofore been achieved in prior similar isocyanate modified products.
The term polyisocyanate or polyfunctional isocyanate is defined as those isocyanate compositions that are at least bifunctional in available --NCO groups. In addition to the preferred poly(diphenylmethane diisocyanate) other lower aliphatic, alicyclic or aromatic polyisocyanates, such as tolylene diisocyanate are also believed to be suitable.
It is an object of the present invention to provide new and useful compositions of matter based on polyfunctional isocyanates modified by 1-20% of triacetin, triethyl citrate, or mixtures of these compounds.
It is another object to provide polyfuntional isocyanate compositions useful for impregnation of cellulosic substrates in order to make products of increased strength and rigidity.
It is an additional object to provide impregnated cellulose-based products in which the isocyanate can be cured to insoluble polyurea compounds under ambient conditions without the need for hot pressing.
It is a further object to provide cellulose substrates impregnated with polyfunctional isocyanate compositions that have greatly reduced residual amounts of unreacted monomeric compounds and reaction byproducts.
These and many other objects will become readily apparent to those skilled in the art upon reading the following detailed description in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing reaction rate of PMDI with three concentrations of triacetin compared with propylene carbonate and neat PMDI.
FIG. 2 is a graph similarly showing reaction rate of PMDI with and without triacetin and propylene carbonate and additionally showing ring crush strength of treated papers.
FIG. 3 is a graph showing residual monomer vs. mount of additive after four days for six chemically related materials including triacetin and triethyl citrate.
FIGS. 4a and 4b are a diagrammatic representation of a corrugating machine in which the present compositions may be employed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A modified cellulosic product was made by impregnating sheets of a 33 lb corrugating medium with 16% of the PMDI isocyanate composition using a gravure roll-type coater. By isocyanate composition is meant the totality of the diisocyanate plus any additive material that might be present. Rate measurements in the work to be described were made by following the disappearance of MDI and/or the change in ring crush strength vs. time.
As was noted before, PMDI contains a large number of oligomers and a substantial amount of monomeric MDI. It was assumed that the reaction rate for MDI would adequately represent the overall diisocyanate reaction rate. Treated paper samples were stored in a freezer at approximately -20° C. for the short time period between impregnation and the commencement of the rate study. After beginning of the rate study samples were stored at room temperature and 50% relative humidity. For MDI determination approximately 1 g samples of the treated paper were first extracted for 2 hours with dry methylene chloride. Aliquots were filtered through a 0.45 μM pore size filter and derivatized with 1-(2-pyridyl)piperazine prior to analysis. This converts all isocyanate to a urea and provides a stable solution for analysis. Samples were then analyzed using high pressure liquid chromatography (HPLC).
FIG. 1 shows disappearance of MDI over time for five different samples. One was impregnated with unmodified (or neat) PMDI. Another used the prior art treatment of a 15% addition of propylene carbonate. The others used 5%, 10%, and 15% additions of triacetin. It will be seen that by four days MDI had dropped to only 2-3% of its original value for all of the triacetin samples. In this same time period MDI in the unmodified sample was still present at a 21% level while that with propylene carbonate had about 14% of the original MDI remaining. Levels of all samples dropped slowly over the next six days of the test period. By 10 days MDI in the triacetin samples was at or below 1% of the original amount present while it was still at about 5% for the other two treatments. It can be assumed that MDA levels in these samples followed those of MDI.
Data for three of these samples is reiterated in FIG. 2 for comparison where development of ting crush strength over time is shown. Ring crush appears to correlate well with the percentage of reacted (or remaining unreacted) MDI. The test is conducted by forming a 12.7 mm by 152.4 mm strip of the paper being tested into a cylinder 49.2 mm in outside diameter. The strip is placed in a grooved holder and top-to-bottom pressure is applied between parallel platens until failure occurs (TAPPI Test Method T 818 om-87). Again, the PMDI with 15% triacetin treated medium proved to be superior in strength development and ultimate strength to PMDI alone or PMDI with 15% propylene carbonate.
FIG. 3 compares triacetin and triethyl citrate with a number of chemically analogous compounds: diacetin, acetyltriethylcitrate, tributyrin, and ethylene glycol diacetate. These were impregnated into 33 lb corrugating medium at usages of 5, 10 and 20% and the percentage of original MDI present determined after four days. Triacetin and triethyl citrate were clearly superior to the other materials except for triethyl citrate at the lowest usage. At 20% usage, based on PMDI, both triacetin and triethyl citrate had less than 0.5% of the original MDI remaining. When measured after only two days, triacetin had only 9% and triethyl citrate 12% of the original MDI remaining. Performance was significantly superior to the other compounds tested with them
The substrate suitable for treatment may be virtually any cellulosic material in sheeted or thin panel form. Chemical pulps such as bleached or unbleached kraft and sulfite, partially delignified materials including semichemical, or thermomechanical pulps, and groundwood or other mechanically defibered pulps have all proved satisfactory. The product of the invention may be sheeted material that is subsequently stored prior to use, during which time significant or full curing will take place, or it may be further manufactured immediately after treatment. The manufacture of corrugated shipping container products is one example of further manufacture immediately after treatment.
At high application speeds to kraft linerboard using a roll coater there was a tendency for air to be entrapped with the isocyanate composition causing foaming. This was alleviated by the addition of a silicone based antifoamer. A treating composition was made using 88 parts by weight of PAPI 2027, a poly(diphenylmethane diisocyanate) material available from Dow Chemical Co., Midland Mich., and 12 parts triacetin. This was used on a rotary coater using a gravure roll and doctor blade and run with a roll speed of 4.6 m/min. While idling without paper being fed through the coater no foaming was observed. However, on feeding 161 g/m 2 kraft liner through the coater heavy foaming was immediately noted. During the next run under similar conditions 0.05% by weight of the isocyanate/triacetin mixture of silicone based Dow Coming Anti-Foam 1400 was added. There was no indication in the coater reservoir of foaming.
EXAMPLE
FIGS. 4a and 4b show a schematic representation of an in-line corrugated board manufacturing process including alternative locations where the isocyanate resin composition can be applied to the board. Briefly, an upstream end is indicated at 10 and a downstream end at 12. At the extreme upstream end of the corrugator is a roll of linerboard 14. It is mounted on stand 16 which allows it to be unrolled continuously. The traveling linerboard sheet is indicated throughout the process flow at 18. Shown positioned on stand 20 is a roll of corrugating medium 22. This is unrolled as a sheet 24 which then proceeds through the process. A second liner stand 26 is positioned downstream from medium stand 20 and has a second roll of linerboard 28 mounted thereon. Extending outward from second liner roll 28 is the sheet of traveling liner 30 which begins its downstream travel and passes through a preheater 31 which serves the same function as preheater 34 explained below. Indicated generally at 32 is a single facer station where the first linerboard sheet 18 is bonded to one side of the fluted corrugating medium 25. Just upstream from single facer station 32 is a preheater 34 and pressure roll 36. Preheater 34 serves to heat the traveling first liner 18 in order to aid in gelation of the starch adhesive normally used to adhere the liner to the fluted medium. Pressure roll 36 serves to keep the sheet under proper tension as it travels into the single facer station 32. Adjacent to single facer station 32 is a pair of corrugating rolls 38, 40 which are standard and web known to those skilled in the art and which serve to form flutes in the incoming corrugating medium 24. Where the corrugating rolls 38, 40 mesh at nip 41, medium 24 will be fluted to become corrugated medium 25. Thereafter the fluted medium is carried around roll 40 where at glue applicator 42 it receives a coating of adhesive on the flute tips. Following this, the fluted medium 25 and first liner 18 are combined at nip 46.
In one embodiment of the invention, at a resin application station generally indicated at 44, the isocyanate composition is sprayed or otherwise applied to all or a portion of the surface of the already fluted traveling medium 25. Alternatively the isocyanate composition may be applied to medium 24 prior to corrugation or to the liner sheet 18. As depicted in FIG. 1, immediately after the isocyanate is applied the typical bonding adhesive, usually a starch-based composition, is applied at nip 46. By applying the adhesive following application of the isocyanate resin composition, the adhesive does not interfere with penetration of the resin into the medium.
In some cases it is advantageous to apply the isocyanate following corrugation to prevent any buildup that might otherwise occur on the corrugator.
At resin application station 44, suitable means are provided, such as a sprayer 48, to apply a predetermined amount of the isocyanate composition to the traveling fluted medium. After the resin is applied to the fluted medium and the medium combined with the first liner 18 and bonded thereto, the traveling singlefaced material 50 moves upwardly and across a bridge station 52 and then further in a downstream direction around a tension and drive station 54 (FIG. 1b). Thereafter, second liner 30 travels upwards toward a nip 56 at the double facer station generally shown at 58. Simultaneously, the single faced material 50 travels toward nip 56 and in the process passes glue applicator 60 where adhesive is applied to the flute tips. As another alternative procedure, the isocyanate composition may be applied upstream from adhesive station 60 by applicator 61. Thereafter, the components are combined at double facer station 58 to form a double backed combined board 70 having two liner sheets with the treated fluted corrugated medium sandwiched between them.
Just downstream from nip 56 is a top pressure roll 62 and beneath the corrugated board is a series of hot plates 64 to further enhance the adhesive bond between second liner 30 and the single faced board 50. Downstream pressure robs 66, 68 apply further light pressure. Following the last hot plate 64 is a cooling section 70. The hot plates typically increase the board temperature to the range of about 93° C. to 120° C. to effect rapid gelation of the starch and evaporation of the water in the adhesive.
Immediately downstream from pressure rolls 66, 68 is a slitting and scoring station 72 and thereafter a cutoff station 74. The flat box blanks are then accumulated on a stacker 76 following which they are ready for further downstream operations which might include application of a manufacturers joint to form a knocked down shipping container.
While in most cases it is preferred to apply the isocyanate composition to the medium, as was noted it may also or alternatively be applied to one or both of the liner sheets.
The inventors have herein disclosed the best mode of operation of their invention as to the time of filing the application. However, it will be readily apparent to those skilled in the art that many variations can be made which are not disclosed herein. These variations should be considered within the scope of the invention insofar as they are included within the encompass of the following claims.
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The invention is directed to a composition of matter useful as a paper impregnant, to the method of its use, and to the products produced by the method. Poly (diphenylmethane diisocyanate) or PMDI has been used in the past as a paper impregnant with or without propylene carbonate as a diluent. These products have generally required pressing under high pressures and at elevated temperatures. It has now been found that triacetin and/or triethyl citrate in usages up to about 20% of PMDI give superior performance in impregnated products. The modified PMDI will cure at essentially ambient conditions in times as short as 1-2 days to insoluble polyureas with low residual amounts of isocyanates and reaction byproducts such as 4,4'-diaminodiphenylmethane. The treated papers can be used in applications of which skins for sandwich panels and high strength corrugated board would be exemplary.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/525,550, entitled “Digital Management of Referral and Provision of Healthcare Services”, filed Nov. 26, 2003, which is incorporated by reference herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates in general to healthcare services referral and management, and more particularly to automatically initiating and tracking referrals of specialty healthcare services as well as tracking intermediate and final results of the specialty services.
[0004] 2. Background Art
[0005] When certain specialty services (whether a diagnostic test or therapeutic procedure) are needed for patient care, it typically takes a series of phone calls, conversations, and the processing of stacks of written notes or printed forms before a medical order for the services is placed by a healthcare referrer, such as a primary care doctor. This manual process is both error-prone and inefficient. It typically takes anywhere from ten to thirty minutes for a referring provider to prepare a patient's order. This time is spent collecting patient demographics, insurance information, and medical records and obtaining insurance authorizations. Much of the communication is done by telephone. Studies show that for a referring provider that is scheduling an average of 10 medial or diagnostic procedures per day it takes an average of three hours per day and 850 hours per year. Missed phone calls, voice mails, and misplaced paper are commonplace and they represent significant waste of human resources. Inefficiency in communication among healthcare referrers, healthcare specialty providers, insurance specialists, and any other relevant parties directly translates into inefficiency in the provision of patient care.
[0006] There are software solutions available today that attempt to address this problem. Physician order entry systems are among them. These systems focus on order creation, and are typically confined to clinical systems or organizations from which a referring provider is operating. The primary objective of these systems is to capture a clinical order and validate its contents for medical accuracy and practice redundancies. These systems, however, do not focus on monitoring intermediate and final results of the order completion.
[0007] Other existing software solutions allow for the display of medical images and diagnostic reports over a web interface. These solutions are typically based on the results of the medical or diagnostic procedure. They are not capable of, for example, placing a medical order and tracking the subsequent follow-up orders that are the recommended course of actions given the results of the services subscribed by the initial order. Thus, none of the existing automated solutions are capable of monitoring the entire life of a specialty order, from its inception to the final completion of the service.
[0008] Accordingly, there is a need for a more efficient mechanism for placing a specialty order and monitoring the results of the completion of the order.
DISCLOSURE OF THE INVENTION
[0009] The above need is met by a referral order management system that captures an initial specialty order from a referral provider office, tracks the relevant patient information regarding the order from a specialty department office, provides automated alerts to physicians and other healthcare professionals at the referral provider office when new order information is available, provides reports on the results of a requested specialty service and follows up with the subsequent recommendations. Such a system facilitates the communications between the referring provider office and the specialty group or department that will be performing the diagnostic or therapeutic procedure.
[0010] In one embodiment, the referral order management system communicates with a referring provider office that creates a specialty order and a specialty department office that will be performing diagnostic or therapeutic procedures indicated in the order and providing updates on the order to the referral order management system. The referral order management system also communicates with an insurance carrier system that services preauthorization requests initiated by the referral order management system. The referral order management system notifies the referring provider office and a specialty department office of the events that are raised as the result of the actions performed on the specialty order. For example, the referral management system provides a notification when a new order is created, when a status of the order is updated, or when the specialty department office has posted results of the procedure indicated in the order.
[0011] In one embodiment, the referral order management system executes various engines to perform the functionality for receiving an initial specialty order, tracking and capturing the relevant patient information regarding the order and providing automatic notifications about the status of the order. These engines include an order processing engine, an eligibility and preauthorization engine, and a notification engine. The order processing engine receives a specialty order from the referral provider office, preferably validates the received order, schedules a procedure indicated in the order, and automatically stores the order.
[0012] The notification engine listens to events that are triggered as the result of the actions performed on the order. In one implementation, the notification engine notifies the referring provider office and the specialty department office of the events, thereby allowing a referring provider office and a specialty department office to monitor the status of the specialty order in real time.
[0013] The eligibility and pre-authorization engine of the referral order management system receives a notification from the notification engine that the new order is stored, preferably determines whether the procedure indicated in the order requires insurance pre-authorization, and sends a request for pre-authorization to an insurance carrier system. The eligibility and pre-authorization engine then receives the pre-authorization information from the insurance carrier system and persists the information into the system. The eligibility and pre-authorization engine also uses eligibility rules to verify whether the procedure indicated in the specialty order is eligible for reimbursement by the insurance carrier.
[0014] Thus, the referral order management system of the present invention tracks the entire life of a specialty referral, from the initial order of the service to the final completion of the service. Such comprehensive digital referral management enables significant reduction of ad hoc or manual communications among specialty service providers, referrers, and patients in order to set up and complete the required specialty services.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a high-level diagram illustrating an environment utilizing an embodiment of the present invention.
[0016] FIG. 2 is a block diagram of the referral order management system.
[0017] FIG. 3 is a block diagram illustrating a more detailed view of a data store of the referral order management system.
[0018] FIG. 4 is an event diagram of a method for ordering specialty services and tracking intermediate and final results of the specialty services.
[0019] FIG. 5 is a flow diagram of the steps performed by the eligibility and authorization engine within the referral order management system.
[0020] FIG. 6 is a flow diagram of the steps performed by the notification engine within the referral order management system.
[0021] The figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 is a high-level block diagram illustrating an environment 100 utilizing an embodiment of the present invention. The illustrated environment 100 includes a referral order management system 190 , a referring provider system 110 , a specialty department system 130 , and an insurance carrier system 170 .
[0023] Referring provider system 110 is a computer system associated with a referring provider's office (not shown in FIG. 1 ). In general, system 110 is an electronic device that allows end-users to interface with referral order management system 190 . System 110 can be, for example, a personal computer system, a portable digital assistant (PDA), a cellular phone, or any other system capable of communicating with referral management system 190 and providing a user interface for displaying information. In one embodiment, system 110 executes a web browser (not shown) such as INTERNET EXPLORER from Microsoft Corp. of Redmond, Wash. Although only one referring provider system 110 is shown in FIG. 1 for purposes of clarity, embodiments of the present invention contemplate any number of referring provider systems interfacing with referral management system 190 . Because in the preferred embodiment the invention is described in the medical context, end-users of system 110 can be physicians, referring provider office administrators, and other medical staff having access to system 110 .
[0024] The referring provider's office uses system 110 to create a specialty referral order 115 a to perform a medical procedure, such as a diagnostic test or a therapeutic procedure, on a patient. System 110 communicates the order 115 a to referral order management system 190 . As used herein, “a specialty order” is a documented direction to perform a medical procedure on a patient. It should be noted that “a specialty order”, “specialty referral order”, and “order” are used herein interchangeably. System 110 includes a user interface that allows a referring physician as well as other members of the referring provider's office staff to monitor the entire life of the order 115 a , from the initial order to the final completion of the procedure listed in the order.
[0025] Specialty department system 130 is a computer system associated with a specialty service provider office (not shown in FIG. 1 ). The specialty service provider performs a medical procedure on a patient as indicated in the specialty referral order. System 130 is adapted to communicate to system 190 any updates 116 a to the status of the order or results of the order. As used herein, “results” are findings ascertained during the performance of the medical procedure. The specialty department office uses system 130 to update the status of an order and add results of the procedure to the order. A specialty service provider office can be an outpatient clinic, a hospital, or any other medical facility that performs diagnostic or therapeutic procedures on patients.
[0026] Referral order management system 190 is adapted to receive a specialty referral order 115 a from system 110 , process the order, perform eligibility and pre-authorization checks, track and capture relevant patient information regarding the specialty service, provide automated alerts 115 b and 116 b to system 110 and 130 respectively when an event occurs. An event can be triggered, for example, when a new order is created, an existing order is updated, results of the order have been submitted, or pre-authorization information is updated on the existing order. Thus, referral order management system 190 tracks and reports to systems 110 and 130 the status of the order at various points of the order processing. Such “real-time” monitoring enables accurate and efficient communications among all entities shown in FIG. 1 participating in the specialty order creation and execution. Various components of referral order management system 190 will be described in more detail below in reference to FIG. 2 .
[0027] System 190 operates in several different modes according to the various embodiments depending on the conditions and needs of a given healthcare information setting. In one embodiment, the referral order management system 190 operates as a web-based system executed on a server (not shown in FIG. 1 ). In another embodiment, the referral order management system 190 is integrated into a third party system or framework (not shown in FIG. 1 ) or a third party portal, and thereby provides to the third party system the functionalities and advantages of automated tracking and management of information surrounding specialty service referral. In yet another embodiment, system 190 operates as a standalone system.
[0028] Whether standalone, embedded in another system, or integrated in a distributed network such as a web framework, the referral order management system 190 tracks the entire process of referring and completing various specialty therapeutic and diagnostic services and thereby allows for easy access of patient information.
[0029] The insurance carrier system 170 is a third party system adapted to receive insurance authorization requests 117 a from system 190 , perform insurance pre-authorization, and provide electronic pre-authorizations 117 b to system 190 for procedures to be to performed on patients. System 170 is associated with an insurance carrier. Although only one system 170 is shown in FIG. 1 , referral order management system 190 can be in communication with any number of insurance carrier systems 170 .
[0030] In one embodiment, system 190 interfaces with systems 110 , 130 , and 170 via networks 119 a , 119 b , and 119 c respectively. Networks 119 a , 119 b , and 119 c allow the electronic exchange of data between system 190 and system 110 and 130 . Networks 119 a , 119 b , and 119 c can be the Internet. However, it will also be appreciated that communication networks 119 a , 119 b , and 119 c can be any known communication network.
[0031] The data exchanged over networks 119 a , 119 b , and 119 c can be represented in various formats, such as the hypertext markup language (HTML), the extensible markup language (XML), or any other representation.
[0000] Referral Order Management System
[0032] Turning now to FIG. 2 , referral order management system 190 includes various engines to perform the functionality of receiving an initial specialty order, tracking and capturing the relevant patient information regarding the order and providing automatic notifications to referring provider system 110 and specialty department system 130 about the status of the order. These engines include an order processing engine 230 , an eligibility and preauthorization engine 240 , a communication engine 250 , a notification engine 210 , and a data store 220 . In one embodiment, these engines are implemented as modules. As used herein, the term “module” refers to computer program code adapted to provide the functionality attributed to the module. The program code is embodied in a random access memory (RAM), a read-only memory (ROM) or other media.
[0033] Order processing engine 230 preferably receives a specialty order from system 110 , validates the received order, schedules a procedure indicated in the order, and automatically stores the order in data store 220 . An exemplary order includes, for example, an order ID, status of the order, patient ID, medical procedure ID, requested physician name, requested date and time when the procedure needs to be performed, and diagnosis. Other data, of course, may be included in the order.
[0034] Data store 220 maintains data utilized by referral order management system 190 to perform its functionality. FIG. 3 is a block diagram of data store 220 . Data store 220 maintains patient records 320 , scheduling records 330 for medical procedures, specialty orders 340 , and insurance data 350 . Data store 220 also keeps track of events 310 that occur within the referral order management system 190 . Data store 220 can be implemented, for example, as a relational database management system (RDMBS) and queries to the data store are accomplished via Standard Query Language (SQL).
[0035] Patient records 320 contain fields for storing data associated with a patient. A field can hold data in the form of numeric, textual, binary information, and any other data type adapted for storage in a data store 220 . In one embodiment, a patient record includes patient identification information, such as patient ID, patient name, Social Security Number (SSN), date of birth, gender, patient insurance information and other patient identification information. Other data may be included as desired.
[0036] Scheduling records 330 include fields for storing data associated with scheduling a procedure. A typical record includes the following fields: an identification of a resource to be used to perform the procedure, date and time when the procedure can be scheduled to perform, and an order ID. As used herein, “a resource” is an entity that is utilized to perform the procedure. A resource can be a room, a piece of equipment, or a person utilized to perform the medical procedure.
[0037] Orders 340 are stored in association with patient records. An order includes, for example, an order ID, patient ID, status, procedure ID, diagnosis, Requesting Physician Name, Requested Date and Time, pre-authorization number, “require pre-authorization” flag, and “require advanced beneficiary notice (ABN)” flag. The ABN is a document that is required to be signed by a patient when the insurance carrier will not pay for the medical procedure. A typical ABN states that the patient has been notified that the insurance carrier will not reimburse the procedure, and the patient is responsible for the payment. In one embodiment, when the “require advanced beneficiary notice (ABN)” flag is set to FALSE, it indicates that the procedure indicated in the order will be reimbursed by the insurance carrier. If the flag is set to TRUE, it indicates that the insurance carrier will not reimburse for the procedure (and hence the patient is required to sign an ABN notice to this effect).
[0038] Insurance data 350 includes information related to various insurance carriers and various insurance plans offered by insurance carriers. This information includes, for example, procedure eligibility, pre-authorization requirements, supported electronic format, co-payment information, and other insurance carrier related information. Exemplary electronic formats supported by various insurance carriers are the Accredited Standards Committee (ASC) X12 protocol and the Health Level Seven (HL7) protocol.
[0039] Data store 220 also stores events 310 that are triggered as the result of the actions performed on the specialty order. Exemplary events are creation of a new order, updating of an existing order, receiving results of the existing order or receiving insurance pre-authorization of the existing order. In one embodiment, stored events have the following format: order ID, event code, and time stamp specifying the time when the event occurred. As will be described in greater details below, notification engine 210 shown in FIG. 2 uses events 310 to provide notifications to referring provider system 110 and specialty department system 130 about the events.
[0040] Referring again to FIG. 2 , referral order management system 190 further executes notification engine 210 . Engine 210 is adapted to listen to data events and perform an action in response to the data events. As previously described, various actions can trigger an event. For example, when order processing system 230 processes the received order and stores the order in data store 220 , a NEWORDER event is triggered. Similarly, when specialty department system 130 communicates to referral order management system 190 results of the medical procedure or simply the status of the medical procedure, RESULTUPDATE and ORDERUPDATE are triggered. Likewise, when insurance authorization engine 240 communicates pre-authorization information to referral management system 190 , a PREAUTHUPDATE event is triggered. These events are stored in data store 220 in association with the identification of the order that triggered the event and the time stamp. In one implementation, engine 210 notifies referring provider system 110 , specialty department system 130 , and eligibility and pre-authorization engine 240 of the events, thereby enabling a referring provider office and a specialty service department to monitor the status of the specialty order in real time. Notifications can be sent using COM interfaces, web service calls, or via XML or HL7 messages.
[0041] Referral order management system 190 further executes eligibility and preauthorization engine 240 . Engine 240 receives notification from engine 210 that a new order is stored, determines whether the procedure indicated in the order requires insurance pre-authorization, and sends a request for pre-authorization to communication engine 250 if the pre-authorization is required. Engine 240 is further adapted to receive pre-authorization information, such as a preauthorization number, from communication engine 250 , and store the information in data store 220 . Engine 240 is also adapted to use eligibility rules to verify whether the procedure is eligible for reimbursement by the insurance carrier. FIG. 5 describes in more detail various steps performed by engine 240 to perform pre-authorization and eligibility processing. Although in the preferred embodiment of the present invention, engine 240 is a part of the referral order management system 190 , other embodiments of the present invention may use third party subsystems for performing the functionality of engine 240 . These systems include those provided by IDX Systems Corporation (www.idx.com) in Burlington, Vt. and WebMD (www.webmd.com) in Elmwood Park, N.J., among others.
[0042] Communication engine 250 is adapted to receive a pre-authorization request from engine 240 , query insurance data 350 in data store 220 for an electronic format that is supported by the insurance carrier whose preauthorization is requested, format the data indicated in the request into the appropriate format, and send the request to system 170 . Communication engine 250 is further adapted to receive pre-authorization information from system 170 and forward the information to engine 240 . In one embodiment, the pre-authorization information includes a pre-authorization number. Engine 250 can be implemented as ConnectR application provided by IDX Systems Corporation of Burlington, Vt.
[0000] Methods of Operation
[0043] FIG. 4 is an event diagram illustrating exemplary transactions among referring provider system 110 , referral order management system 190 , insurance carrier system 170 , and specialty department system 130 . In FIG. 4 , the above entities are listed across the top. Beneath each entity is a vertical line representing the passage of time. The horizontal arrows between the vertical lines represent transactions between the associated entities. It should be noted that not every transaction is shown in FIG. 4 . In other embodiments of the present invention, the order of the transactions can vary.
[0044] Initially, when a referring provider office (not shown in FIG. 4 ) creates a new order for a medical procedure for a patient, the office causes system 110 to send a query 410 to data store 220 within system 190 for data associated with the patient using, for example, the patient ID, patient name, or patient SSN. If the order is created for an existing patient (e.g., the patient ID matches the patient ID of the existing record), then system 110 preferably updates the patient's record in data store 220 with the newly created order. Otherwise, system 110 causes a new patient record to be created in data store 220 and causes the patient record to be populated with the data for the newly created order and other additional information as can be determined.
[0045] Within referral order management system 190 , order processing engine 230 receives 430 the order and processes 440 the order. In one embodiment, processing of the order includes the following steps: validating the order and scheduling the procedure indicated in the order.
[0046] To validate the order, engine 230 preferably determines whether the received order contains enough information to support further processing of the order. In one embodiment, the received order has to include at least one of a patient name, ordered procedure ID, diagnosis, and requesting physician name. Otherwise, engine 230 rejects the order and generates an “incomplete order” event, which is communicated to referring provider system 110 via an event notification. Such a notification may be provided in the form of the electronic message.
[0047] If the order contains enough information to support further processing of the order, engine 230 within system 190 further performs scheduling of the order. As previously described, data store 220 maintains scheduling records 330 . An exemplary scheduling record includes, for example, the following fields: a name of the resource, date and time when the resource is available, and order Id. A resource is an entity that is used to perform the procedure. A resource can be a room, a piece of equipment, or a physician required to perform the ordered procedure. If the resource has already been scheduled, the order ID, for example, is set to “1”. Alternatively, order ID is set to “0”. Thus, scheduling records for resource Cath Lab may look like the one shown in Table 1:
TABLE 1 Exemplary Scheduling Records Name of the Resource Date Time Order ID Cath Lab 1 Jan. 2, 2005 5:15 p.m. 1 Jan. 2, 2005 5:30 p.m. Jan. 2, 2005 5:45 p.m.
[0048] In this example, Cath Lab 1 is not available at 5:15 p.m. because the order ID is set to “1”.
[0049] To schedule the procedure, order processing engine 230 queries data store 220 for the resources that can be used to perform the ordered procedure. Engine 230 loops through scheduling records for each resource and uses the following metrics such as the duration of the procedure and the requested date and time to find an available time slot for the ordered procedure. In one embodiment, engine 230 searches for consecutive records for a given resource having a cumulative duration of time equal or greater to the time specified in the order for the duration of the procedure. If engine 230 does not find an available time slot to schedule the procedure (e.g., the order ID is set to “1”), engine 230 searches scheduling records for another resource that can be used to perform the procedure until the available resource is found.
[0050] Those skilled in the art would appreciate that in other embodiments of the present invention an order may require that more than one resource be available for a procedure to be performed. For example, an order for a Cardiac Intra-Vascular Ultrasound (IVUS) procedure may require that the Cath Lab and the ultrasound equipment be available at the same time. To this end, engine 230 searches scheduling records for more than one resource to find an available time slot so as to schedule the procedure.
[0051] Once order processing engine 230 schedules the procedure indicated in the order, engine 230 stores the processed order in data store 220 . Thus, data store 220 now stores the order along with the scheduled date and time, duration of the procedure, and the resource that will be used to perform the procedure.
[0052] As was previously described, certain actions performed on a specialty order by various entities can trigger events. Thus, when a new order is stored in data store 220 , it triggers an event 450 . System 190 notifies 460 referring provider system 110 of the event. Data store 220 keeps track of events that occur within system 190 . As previously described, in one embodiment, an event is stored in the form of an event code, order ID, and a time stamp indicating when the event took place. Thus, when a new order is created at 5:00 p.m. on Nov. 23, 2004 having the order ID “ 12345 ” the following event will be stored in 310 :
TABLE 2 Exemplary Events stored in Data Store 220. Time Stamp Event Code Order ID Nov. 23, 2004 NEWORDER 12345 5:00 p.m.
[0053] When a patient reports to a specialty department office at the time instructed in the specialty order, the office staff updates the order in the specialty department system 130 . As the patient undergoes the procedure indicated in the order, the specialty department office staff monitors the status of the order and stores the status of the order into the system 130 . For example, when the patient currently undergoes the procedure, the order status is “In-progress”; when the procedure is completed, the order status is “Completed”. In addition, specialty department staff adds results of the procedure to the order. The results are findings that are ascertained after the performance of the medical procedure. The specialty department staff can also include follow-up recommendations. For example, if the ordered procedure is a mammography-screening test, the findings may be abnormal tenderness of the breast tissue. The follow-up recommendation may be a biopsy. The specialty department staff enters the order status, the results, and follow-up recommendations to system 130 . System 130 sends 470 to system 190 a message that preferably includes an order status, an order results, responsible physician, and suggested follow-up recommendations. In one implementation, system 130 updates data store 220 with the new order information.
[0054] When referral order management system 190 receives 470 status order updates or result order updates it triggers 480 an event. When an update to the status of the order is received, a new event is stored in events 310 in association with the order ID with the event code “ORDERUPDATE”. Similarly, when a change was filed on the order result, a new event is stored in events 310 in association with the order ID with an event code “RESULTUPDATE”. As previously described, each event in events 210 has a time stamp specifying the time when the event occurs. In addition, status of the order, results of the order, and follow-up recommendations are persisted to data store 220 .
[0055] Notification engine 210 listens for data events. In one embodiment, engine 210 queries events 310 in data store 220 having a time stamp greater than the time stamp of the last query that was performed by engine 210 .
[0056] In another embodiment, engine 210 subscribes to a message queue mechanism, such as Microsoft Message Queue or IBM MQ Services, to receive new events stored in events 310 .
[0057] FIG. 6 is a flow diagram illustrating the steps performed by notification engine 210 according to one embodiment of the present invention. At step 610 , engine 210 receives a new event. Engine 210 extracts the order ID from the event and queries data store 220 for data associated with the order having the extracted order ID. In response to the query, engine 210 receives the stored order 620 , along with its results and updates, as well as insurance pre-authorization information (as will be described in more detail later). Engine 210 maintains business rules for routing events. As an illustrative example, a rule may indicate that if Event Code=NEWORDER, then route the event to system 110 , system 130 , and engine 240 . If Event Code=ORDERUPDATE, then route the event to system 110 . Engine 210 routes the events responsive to the rules. Thus, if the event code is NEWORDER 630 , engine 210 notifies 640 referring provider system 110 . Engine 210 also notifies 650 specialty department system 130 . The notification includes the updated order. In one implementation, notifications can be sent using COM interfaces, web service calls, or via XML messages. When the referring provider office staff receives the results of the procedure, it enables the staff to initiate a new order request based on the text of the provided result. Engine 210 also notifies 660 eligibility and pre-authorization engine 240 (shown in FIG. 2 ).
[0058] If the event code is ORDERUPDATE or RESULTUPDATE 670 , engine 210 notifies 640 referring provider system 110 . If the event code is PREATHUPDATE, engine 210 notifies 640 referring provider system 110 .
[0059] Referring again to FIG. 4 , within referral order management system 190 , eligibility and preauthorization engine 240 performs 485 eligibility verification and preauthorization. FIG. 5 is a flow diagram illustrating the steps performed by eligibility and pre-authorization engine 240 . Those skilled in the art will recognize that alternative embodiments of engine 240 may perform the illustrated steps in different orders, perform additional steps, or even omit certain steps.
[0060] Engine 240 receives 510 a new event indicating that the new order is stored. Engine 240 also receives data associated with the order. Engine 240 determines 520 if insurance pre-authorization is required for the procedure indicated in the order. In one implementation, engine 240 uses the order ID indicated in the new event notification to determine the patient insurance carrier. Engine 240 determines whether the patient's insurance carrier requires pre-authorization for the procedure indicated in the order. If the insurance carrier requires pre-authorization for the procedure, engine 240 determines 540 whether the insurance carrier supports an electronic request for pre-authorization. If so, engine 240 communicates 550 the request for preauthorization to communication engine 250 within system 190 . The request includes, for example, patient ID, ordered procedure, diagnosis ID, insurance carrier, and requesting physician name.
[0061] If the insurance carrier does not support an electronic request for pre-authorization, engine 240 does not enter a pre-authorization number and sets the “required preauthorization” flag to TRUE in orders 220 . Engine 240 notifies 530 referring provider system 130 that verbal insurance authorization is required for the procedure indicated in the order.
[0062] If the insurance carrier does not require pre-authorization for a procedure indicated in the order, engine 240 does not enter a pre-authorization number in orders 340 and sets the “required preauthorization” flag to FALSE in orders 220 . As part of the eligibility verification, engine 240 then determines 560 whether the procedure requires advanced beneficiary notice (ABN). In one implementation, engine 240 uses insurance data 350 in data store 220 to determine whether the insurance carrier reimburses for the procedure indicated in the order that needs to be performed in connection with a diagnosis indicated in the order. If the insurance carrier reimburses for the procedure for the diagnosis indicated in the order, then the “required ABN” flag in orders 310 is set 580 to FALSE. In the alternative, the “required ABN” flag is set to TRUE for this order, and engine 240 notifies 570 referral provider system 110 that the patient is required to sign the advance beneficiary notice, which indicates that the procedure will not be reimbursed by the insurance carrier and the patient is responsible for the payment.
[0063] In other implementations, engine 240 uses more complex eligibility rules to determine whether a certain procedure is eligible for reimbursement by insurance carrier. For example, eligibility rules may take into account the patient's age, gender and previous orders in considering whether or not a procedure will be reimbursed. For example, to be eligible for a mammography-screening test, a woman must be at a certain age before an insurance carrier will pay for one screening test every 2 years. Once a woman reaches 50 years old, insurance carriers typically pay for one screening annually. If a screening procedure has a result that indicates that a follow-up examination is necessary regardless of the age, the carrier will reimburse for additional procedures provided that the diagnosis requires so (e.g., suspicious abnormality found during physical exam). If a carrier elects not to reimburse the procedure, the patient may elect to have the procedure performed, provided the patient signs an ABN notice and pays for the procedure.
[0064] Referring again to FIG. 4 , within referral order management system 190 , communication engine 250 sends 490 a pre-authorization request to insurance carrier system 170 . The request includes, for example, patient ID, insurance carrier, ordered procedure and diagnosis ID.
[0065] Insurance carrier system 170 receives 490 the preauthorization request and provides the response 492 to communication module 250 within referral order management system 190 , which in turn sends the response to eligibility and pre-authorization engine 240 . The response may include patient ID, ordered procedure, pre-authorization number, and a flag indicating whether the procedure will be reimbursed. Engine 240 associates the received information with the order ID and updates the order in data store 220 with the received information.
[0066] When referral order management system 190 receives 492 a preauthorization response, an event is triggered 494 . The new event having an event code “PREATHUPDATE” in stored in events 310 in association with the order ID with a time stamp specifying the time when the event occurs. Notification engine 240 notifies 496 referring provider system 110 of the new event.
[0067] Thus, the present invention advantageously captures the initial specialty order, tracks the relevant patient information regarding the order, provides automated alerts to physicians and other healthcare, professionals when a new order information is available, communicates the order results, and follows up with the subsequent recommendations and results of the ordered diagnostic tests or therapeutic procedures without paper-based communication with the specialty department office. Thus, some of the benefits of the present invention are in that it significantly reduces paper-based communications between specialty service providers and referrers to initiate a specialty order and complete services prescribed in the order. In addition, the present invention lightens medical staff workload by automating a scheduling procedure.
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According to various embodiments, methods and systems are provided for facilitating and managing communications between healthcare service referrers and healthcare service providers. Such communications are transacted via digital networks in connection with a healthcare information system. Referral of various diagnostic and therapeutic specialties is tracked from the initiation by the referrers to the completion of the services by the specialty service providers. Validation of insurance authorization is performed automatically if needed. Reports on the results of a requested specialty service as well as intermediate recommendations are made available to the referrer or other relevant entities upon completion of the service.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Stage of International Application No. PCT/EP2009/066316 filed on Dec. 3, 2009 which was published in German on Jun. 17, 2010 under International Publication Number WO 2010/066630.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates to a bipolar semiconductor memory device comprising one or more vertical bipolar transistors which have an emitter region, a base region and a collector region, wherein the emitter in standard T-shaped design laterally overlaps the base connection region laterally adjoining the base. The invention also relates to a method for producing such a bipolar semiconductor device.
[0004] 2. Discussion of Related Art
[0005] The performance of silicon-based bipolar transistors (or bipolar junction transistors (BJT)) has been significantly improved in the field of high-speed semiconductors by novel component designs and material components, and by reductions in the size of structures.
[0006] Key features of modern vertical high-speed bipolar transistors are described in K. Washio, “SiGe HBT and BiCMOS Technologies”, IEDM, pp. 113-116, 2003. More advanced embodiments can be found in DE 10 2004 061327 and in US 2005/006724.
[0007] Known designs contain highly conductive base and collector connection regions which conduct the charge-carrying current from the inner region of the transistor to the respective contact regions. High conductivity is achieved with locally well-controlled doping and, in at least one design, with a monocrystalline base connection region. In order to simultaneously ensure a low capacitance between the base connection region and the other electrical connections of the transistor, the semiconductor regions are separated from each other by insulator regions with low dielectric constants, e.g., by silicon dioxide. The resultant overlaps of the emitter and collector regions with the base are kept as small as possible, which is specifically achieved with self-aligning methods.
[0008] “Double polysilicon technology” and “single polysilicon technology” with differential base epitaxy have been established as production methods for silicon-based bipolar (junction) transistors (BJT). The latter method has been developed with technologies for reducing the base resistance and the base-collector capacitance, as described in DE 10 2004 061 327, and with technologies for maximizing the use of self-aligning production methods, as described in US 2005/006724. These methods shall now be discussed in more detail.
[0009] a) Double Polysilicon Technology
[0010] The interrelationships are illustrated first of all for double-polysilicon technology with reference to FIG. 1 , which shows a prior art bipolar transistor in cross-section, the main features of which are the same as the transistor in FIG. 1( a ) in the aforementioned publication by Washio. A collector region 20 is bounded at the bottom by a substrate 10 and laterally by wells 11 in the silicon that are filled with silicon dioxide (SiO 2 ) and which are also called “field isolation regions”. Various prior art embodiments use either shallow field isolation regions in the form of shallow trenches (shallow trench isolation, STI), as shown in FIG. 1 , or, alternatively, deep trenches.
[0011] In the vertical direction, the collector region 20 is composed of a highly doped collector region 21 on the substrate side and a lightly doped collector region 23 above the highly doped region. In the lateral direction, the collector region is adjoined under the STI regions 11 by portions 22 of a collector connection region.
[0012] A collector window 34 is formed above the collector region 20 , in a layer stack comprising a first insulator layer 30 , a polysilicon layer 31 and a second insulator layer 32 . By selectively etching the first insulator layer 30 , a portion of the polysilicon layer 31 projecting laterally beyond the first insulator region 30 is produced at the lateral edge of the window 34 . The end faces of the overhanging portion of polysilicon layer 31 are provided with spacers 50 made of insulator material.
[0013] During a selective epitaxy step for producing a base layer 40 , silicon fronts grow simultaneously from the exposed portions of the polysilicon layer 31 and the collector region 20 toward each other in a vertical direction and close the gap between the polysilicon layer 31 serving as part of the base connection region and the inner transistor region.
[0014] A T-shaped emitter region 60 adjoins the base layer 40 at the bottom with a vertical portion corresponding to the vertical bar of its T-shape, and laterally adjoins the spacers 50 . Deposited over the SiGe layer is a cap layer which can receive dopants diffusing out of the emitter during the production process and which can receive at least part of the base-emitter space charge zone. The boundary of the cap layer on the emitter side is indicated by a broken separating line in the emitter. Portions of the emitter 60 , corresponding to the horizontal bar of the T-shape, rest sideways on the second insulator layer 32 .
[0015] Another typical feature of this known transistor design is a selectively implanted collector (SIC) region in which the level of collector doping is raised locally in order to simultaneously minimize the collector-base transit time, the base-collector capacitance and the collector resistance in a way that permits good high-speed properties on the part of the transistor.
[0016] In this design, various dimensions are self-aligning: firstly, the overlap between the polysilicon layer 31 and the selectively grown base 40 , which simultaneously has an importance share of the base-collector capacitance. The lateral distance between the highly doped polysilicon layer 31 and the emitter window 62 is likewise self-aligned by spacers 50 . The position of the SIC region 33 is likewise self-aligning in relation to the collector window 34 and to the emitter window 62 , in that the opening provided by means of spacers 50 in the polysilicon layer 31 serves as masking.
[0017] b) Single Polysilicon Technology
[0018] FIG. 2 shows a cross-sectional view of another vertical bipolar transistor according to the prior art. A portion of the inner transistor region is shown schematically, as are the adjoining base connection and collector connection regions. The transistor in FIG. 2 has a single-polysilicon structure with a differentially deposited base. Essential features of the collector design are identical to those of the double-polysilicon variant shown in FIG. 1 .
[0019] A collector 120 is enclosed from below by a substrate 110 and toward the sides by STI regions 111 . The collector 120 has a highly doped portion 121 at the substrate side. Toward the surface, the collector has a lightly doped portion 123 . Unlike the double-polysilicon structure shown in FIG. 1 , in which the polysilicon layer 31 is deposited independently of the base layer, the single-polysilicon variant involves depositing polycrystalline semiconductor material 130 during the differential epitaxy step for producing the base on the field isolation regions, wherein said polycrystalline semiconductor material 130 can be used as part of the base connection region.
[0020] For the reasons mentioned further above, an SIC region 133 is used in the same manner as in the double-polysilicon variant. Known single-polysilicon transistor structures also typically have more weakly doped silicon regions in lateral proximity to the SIC region 133 , which cause undesired capacitances between the base connection and collector regions.
[0021] As in the double-polysilicon variant, the emitter is executed as a T-shape, the width of the overlap 161 beyond the emitter window 162 being photolithographically aligned, as in double-polysilicon technology.
[0022] c) Vertically Insulated Monocrystalline Base Connection Region Technology
[0023] FIG. 3 shows a cross-section of a third bipolar transistor according to the prior art. A section of the inner transistor regions is shown schematically, as are the adjacent base connection and collector connection regions. The transistor in FIG. 3 has a single-polysilicon structure with a differentially deposited base, which in contrast to the transistor shown in FIG. 2 permits the formation of a monocrystalline base connection region and has a reduced parasitic base-collector capacitance due to the special structure of the collector region.
[0024] A collector 220 is enclosed from below by a substrate 210 and toward the sides by STI regions 211 . The collector 220 has a highly doped portion 221 on the substrate side.
[0025] The transistor has a first semiconductor electrode which is made of monocrystalline semiconductor material of a second conductivity type and which is disposed in an opening of the insulation region, said electrode being configured either as a collector or as an emitter and having a first vertical portion which is enclosed by the insulation region in a lateral direction perpendicular to the vertical direction, and an adjoining second vertical portion further distanced in the vertical direction from the interior of the substrate, wherein said second portion is not enclosed laterally by the insulation region.
[0026] The transistor also has a second semiconductor electrode made of a semiconductor material of the second conductivity type, which is embodied as the other type of semiconductor electrode, i.e., as an emitter or alternatively as a collector, a base made of monocrystalline semiconductor material of the first conductivity type disposed between the collector and the emitter, and a base connection region which has a monocrystalline portion that surrounds the base in the lateral direction and that, seen from the base, laterally surrounds the second vertical portion of the first semiconductor electrode lying further toward the substrate interior, said portion also resting directly on the insulation region with its underside facing the substrate interior, and which is referred to as a vertically insulated monocrystalline base connection region.
[0027] Here, the emitter window 262 is positioned self-aligningly with respect to the base connection region and with respect to the SIC, whereas the width of the overlap 261 of the emitter beyond the emitter window 262 and the base connection region 230 is photolithographically aligned.
[0028] d) US 2005/006724
[0029] FIG. 4 shows a cross-section of a fourth bipolar transistor according to the prior art. A section of the inner transistor region is shown schematically, as are the adjacent base connection and collector connection regions. The transistor shown in FIG. 4 has a structure with a differentially deposited base, said structure being characterized by extensive use of self-aligning methods.
[0030] A collector 320 is bounded at the bottom by a substrate 310 . In contrast to the preceding embodiments of prior art transistors, the collector 320 is guided over a connection region 321 and under insulation region 311 to the collector contact region 322 .
[0031] The transistor is formed in a window of a base connection region made of polysilicon 331 , said region being opened above the region of the collector 320 .
[0032] By means of differential epitaxy, a monocrystalline base layer stack 307 and a weakly doped cap layer 308 are deposited over the collector region, while a polycrystalline connection 310 is formed at the side walls of the base connection region.
[0033] L-shaped spacers 350 , which are likewise formed inside the window in the base connection region 331 , separate the emitter 360 from the base connection region 331 . In this embodiment, the entire emitter is self-aligning with respect to the opening in the base connection region.
[0034] The width of the region of the T-shaped emitter 360 which projects beyond the emitter window 362 , said region being separated from a base connection region 309 by the lower part of spacers 350 , is aligned with the opening in the base connection region 331 and hence also with the emitter window 362 by the L-shaped spacers 350 .
SUMMARY CRITIQUE OF THE PRIOR ART
[0035] In the field of double-polysilicon technology, the achieved prior art only permits the emitter window to be positioned self-aligningly with the collector window. No such self-alignment is known in the case of single-polysilicon technology.
[0036] As a consequence, it has not been possible until now to self-align the width of lateral overlapping of the generally T-shaped emitter with the base connection region that laterally adjoins the base, in a manner than is independent of other important dimensions of the transistor.
[0037] More specifically, it has not been possible to adjust the extent of lateral overhang of the horizontal bar of the T-shaped emitter self-aligningly with the emitter window, without altering the gap between the emitter window and the base connection region at the same time. In particular, the length of the base connection region, which accounts for a significant proportion of the base resistance, is directly related to the width of the T-shaped emitter.
[0038] In summary, the emitter cannot be designed and optimized independently of the base connection region.
[0039] In known production processes, the position and dimensions of the T-shaped emitter are also adjusted by using a photolithographically positioned mask. This leads to a situation in which the dimensions of the overlap cannot be designed without taking account of the error tolerances associated with the photolithographic process.
[0040] It would be desirable to minimize this overlap region, firstly in order to reduce the parasitic capacitance resulting from the area of the overlap. Secondly, the parasitic resistance of the base connection region could also be reduced in this way, in that highly conductive regions of the base connection can be brought closer to the inner base when the overlap is small than is possible in the prior art. Such regions are, for example, silicide, an epitaxial reinforcement of the base connection region or an additional implantation of the base connection in order to increase the doping level.
[0041] The known transistor arrangements shown in FIGS. 1 , 2 , 3 and 4 also illustrate a second aspect that is worthy of criticism: In FIGS. 1 , 2 and 4 , those parts of the base connection lying on the insulator region consist of polycrystalline material, as a result of which the impedances at contacts and supply lines are noticeably increased in relation to values for monocrystalline material. In FIG. 3 , in contrast, the base connection is produced from monocrystalline material. However, it would be desirable to reduce the resistance of the base connection region even further.
[0042] The aforementioned disadvantages of the prior art stand in the way of any further improvements in the high-frequency characteristics of a bipolar transistor.
[0043] The technical problem addressed by the invention is therefore to specify a semiconductor device for vertical bipolar transistors, in which improved properties for high-speed applications are achieved by reducing or completely preventing the disadvantages of known embodiments, as described above, especially with regard to parasitic capacitances and resistances.
[0044] Another technical problem addressed by the invention is to specify a method for producing a bipolar semiconductor device, with which the disadvantages of known methods, as described above, can be reduced or completely prevented, especially with regard to parasitic capacitances and resistances.
DISCLOSURE OF INVENTION
[0045] These problems are solved by a semiconductor memory device according to claim 1 , comprising, in one embodiment, a substrate layer made of a semiconductor material of a first conductivity type and having a first insulation region, and a vertical bipolar transistor having
a first vertical portion of a collector made of monocrystalline semiconductor material of a second conductivity type and disposed in an opening of the first insulation region, a second insulation region lying partly on the first vertical portion of the collector and partly on the first insulation region and having an opening in the region of the collector, in which opening a second vertical portion of the collector made of monocrystalline material is disposed, said portion including an inner region of the second conductivity type, base made of monocrystalline semiconductor material of the first conductivity type, a base connection region surrounding the base in the lateral direction, a T-shaped emitter made of semiconductor material of the second conductivity type and overlapping the base connection region,
wherein the base connection region, aside from a seeding layer adjacent the substrate or a metallization layer adjacent a base contact, consists of a semiconductor material which differs in its chemical composition from the semiconductor material of the collector, the base and the emitter and in which the majority charge carriers of the first conductivity type have greater mobility compared thereto.
[0051] The semiconductor device according to the invention is distinguished by its bipolar transistor having especially good high-frequency characteristics. These are achieved by a reduced resistance of the base connection region, which due to the inventive structure, especially when using the inventive method described below, is accompanied by an especially low parasitic base-emitter capacitance of the bipolar transistor.
[0052] An essential aspect for reducing the base resistance is that the base connection region is a region with particularly good conductivity. In the semiconductor device according to the invention, this is achieved by producing the base connection region, aside from a seeding layer adjacent the substrate or a metallization layer adjacent a base contact, from a semiconductor material which differs in its chemical composition from the semiconductor material of the collector, the base and the emitter, and in which the majority charge carriers of the first conductivity type have greater mobility compared thereto. In the case of a p-conductive base connection region, the material therefore has higher hole mobility and, in the case of an n-conductive base connection region, enhanced electron mobility.
[0053] The bipolar transistor according to the invention has a low parasitic base-emitter capacitance due to the inventive option, described further below, of self-aligning production of the lateral overlap of the emitter and the base connection region. The overlap region can be made smaller by eliminating the error tolerances that have to be taken into account when aligning with photolithographic methods, as is otherwise common. Due to the horizontal bar of the T-shaped emitter having a smaller overlap, it is possible for highly conductive portions of the base connection region to be brought particularly close to the inner transistor. These highly conductive portions may, for example, be silicided regions, epitaxial reinforcements of the base connection region, or regions that are more highly doped by implantation.
[0054] Basically, this advantage can also be achieved when the base connection region is made from the same material as the functional layers of the inner transistor. When both features are combined, the base connection region of a vertical bipolar transistor is significantly improved with regard to its high-frequency characteristics.
[0055] Embodiments of the inventive semiconductor device shall now be described. As can also be seen from the backward references in the attached claims, the additional features of the embodiments can also be combined with each other to form further embodiments, unless these additional features are disclosed as alternatives to each other.
[0056] The material of the base connection region is preferably silicon germanium, with a germanium content of more than 35%, i.e., Si 1-x Ge x , where x is at least 0.35. Silicon germanium with such a high germanium content is distinguished by a significantly higher hole mobility compared to silicon. In this way, it is possible to achieve a particularly low resistance in the base connection region with materials that are compatible with known industrial production processes. An even stronger effect in this direction can be achieved by using silicon germanium with a germanium content of more than 50% for the base connection region or, with yet further improvement, of more than 80%.
[0057] In one embodiment, the material of the base connection region is germanium (“x=1”), whereas the material of the collector, base and emitter is silicon or silicon germanium. Compared to silicon, germanium has an enhanced hole mobility that is as much as ten times higher. Germanium has a significantly increased hole mobility even in comparison with standard variants of silicon germanium.
[0058] It should be understood that the comparison of hole conductivities of different materials is based on at least approximately equal dopant concentrations, and that only such dopant concentrations that are within a range of interest for transistor production may be considered.
[0059] The use of monocrystalline semiconductor material, as such a material in the base connection region that is different from the material inside the transistor, provides an additional advantage compared to known prior art variants. The base connection region may be wholly or partly monocrystalline in different embodiments of the semiconductor device. For example, the base connection region may contain two subregions, of which only one first subregion in the immediate proximity of the base is monocrystalline, the second subregion being polycrystalline.
[0060] An at least partly monocrystalline base connection region ensures improved conductivity compared with polycrystalline material. “Monocrystalline” refers here to portions that have a uniform crystallographic orientation that is either predefined by the substrate or which correspond to one of the other highly symmetric surface orientations, which in the case of silicon are surface orientations (100), (110), (111) or (311). In contrast thereto, “polycrystalline regions” are regions consisting of a plurality of crystallites with different crystallographic orientations, which border each other at grain boundaries and which may have dimensions ranging from a few nanometers to a few hundred nanometers.
[0061] Further reduction of the base resistance is made possible by increasing the layer thickness of the base connection region at a certain distance from the inner base.
[0062] A buffer layer made of monocrystalline semiconductor material and disposed between the collector and the base is preferred.
[0063] A cap layer made of monocrystalline semiconductor material may be disposed between the base and the emitter.
[0064] If one views a semiconductor memory device having a plurality of vertical bipolar transistors with a structure as defined by the invention, what can be achieved is that the emitter is T-shaped, with the horizontal bar of the T-shape outwardly overlapping the respective base connection region, the lateral extension of said overlap having a maximum variation of 10 nanometers over the total number of said bipolar transistors of the semiconductor memory device. Such a homogenous structure in respect of this overlapping may be achieved by the inventive method, as shall now be described.
[0065] According to a second aspect of the present invention, a method for producing a vertical bipolar transistor is specified, in which
a window is produced in the lateral region of the collector, in a layer stack which is partly deposited on a first vertical portion of a collector ( 420 ) and partly on an insulator region ( 411 ) surrounding the latter, a second vertical portion of the collector and a base stack are deposited in the window, a base connection region laterally adjoining the base stack is produced, a lateral recess extending laterally beyond the window is produced in at least one layer of the layer stack above the base stack, and a T-shaped emitter is produced with the lateral recess being filled thereby, a lateral extension of the horizontal T-bar and its lateral overlap with the base connection region being predefined by the lateral recess.
[0071] With the method according to the invention, a self-aligning adjustment of the width of overlap of the horizontal bar of the T-shaped emitter over the base connection region is achieved. In this context, self-alignment means that the lateral positioning or structural expansion of a region in relation to previously produced regions is not effected by adjusting a photolithographic mask, but rather that the previously produced regions themselves define the positioning and are used as masking for steps in the process, possibly with spacers provided. In this way, positioning errors are eliminated and dimensions such as distances between regions are defined by well-controlled processes such as layer depositions, which on the whole permits significant reduction of distances and dimensions compared to regions which are positioned in relation to each other with photolithography. The error tolerances in the dimensioning of overlaps, that occur with the lithographic methods used hitherto, do not need to be taken into account in the vertical bipolar transistor according to the invention, thus producing the advantages, already described in the foregoing, of especially low parasitic base-emitter capacitance, which improves the high-frequency characteristics of the transistor.
[0072] In one embodiment, the method according to the invention can be carried out in such a way that the base connection region, aside from any seeding layer adjacent the substrate or a metallization layer adjacent a base contact, is produced from a semiconductor material which differs in its chemical composition from the semiconductor material of the collector, the base and the emitter and in which the majority charge carriers of the first conductivity type have greater mobility compared thereto. The advantages of this method have already been described in the foregoing, in connection with embodiments of the inventive semiconductor device. A seeding layer may be used to improve the crystalline properties of the base connection region, in a manner known per se, in particular in the production of a monocrystalline base connection region. However, this is not an absolute necessity. A metallization layer may also be produced without previously covering the base connection region with an additional semiconductor layer, such as silicon, in order to produce a metallization layer made of titanium silicide or cobalt silicide. For germanium, for example, a nickel silicide layer can be produced without having to deposit a silicon layer before forming the silicide. However, it is possible to dispense with producing the metallization layer for some applications that do not exploit the advantage of the metallization layer.
[0073] The method proceeds advantageously, for deposition of the layer stack, from a high-impedance monocrystalline semiconductor substrate of the first conductivity type, which is provided in previous steps of the method with the first vertical portion of a collector region of the second conductivity type, which is laterally bounded by a first insulation region.
[0074] There are two alternative variants available for the subsequent execution of the method.
[0075] In a first variant, the layer stack is produced in the direction of layer growth such that it either contains or consists of the following combination of layers: a second insulation region, a polycrystalline or amorphous semiconductor layer, an insulating layer, a first auxiliary layer and a second auxiliary layer. A detailed description of an embodiment based on this first variant is described in more detail below, with reference to FIGS. 5-12 .
[0076] In a second variant, the layer stack is produced in the direction of layer growth such that it either contains or consists of the following combination of layers: a second insulation region, a first auxiliary layer, a second auxiliary layer and a third auxiliary layer. A detailed description of an embodiment based on this second variant is described in more detail below, with reference to FIGS. 13-21 .
[0077] In the following, embodiments of the first variant shall firstly be described.
[0078] The window is preferably formed in the layer stack in such a way that the window extends in the lateral region of the collector from the second auxiliary layer in the depth direction as far as the boundary surface between the semiconductor layer and the second insulation region. This permits subsequent access to the second insulation region in order to produce the second vertical portion of the collector-base stack in the inner transistor region.
[0079] However, before the second insulation region in the region of the window is opened in order to produce the second vertical portion of the collector, spacers are advantageously formed on the inner walls of the window. By means of the spacers, it is possible to adjust the lateral expansion of a SIC region which is preferably formed in the upper vertical portion of the collector in a subsequent implantation step. They also prevent any lateral “growth” of the window, in particular in the region of the semiconductor layer of the layer stack. Implantation of the SIC region may basically be carried out before or after a base stack is deposited in the window.
[0080] The spacers are also helpful for further execution of the method, however. In the further course of the method, the spacers are therefore removed only partly from the side wall of the semiconductor layer that will form the base connection region, followed by selective epitaxial deposition of the base stack in the region of the window. In one embodiment, the base stack consists of a buffer layer, a base layer and a cap layer. Deposition is now carried out preferably in such a way that a polycrystalline inner region of the base connection region is simultaneously produced at the side wall of the semiconductor layer. This can be achieved, for example, by attacking the spacers from below as well when partly removing them, so that in the region of the semiconductor layer they are fully removed in some portions.
[0081] In this first variant, the recess in one embodiment can be produced by selective, lateral etch-back of the first auxiliary layer in the region of the window, such that a lateral recess extending beyond the window is produced in the first auxiliary layer. This means that the T-shaped emitter is then deposited self-aligningly in the window and in the recess in the first auxiliary layer, wherein the width of the lateral overlap of the emitter and the base connection region, beyond the lateral extension of the window, results in a self-adjusted manner, in accordance with the invention, from the width of the etch-back of the first auxiliary layer.
[0082] Embodiments of the second variant shall now be described.
[0083] Here, too, the window is preferably formed in the layer stack in such a way that the window extends in the lateral region of the collector region in the depth direction as far as the first vertical portion of the latter. Selective epitaxial deposition of a second vertical portion of the collector is then preferably carried out in the region of the window and a base stack. In one embodiment, the base stack consists, in the direction of growth, of a buffer layer, a base layer and a cap layer. The layer stack preferably grows to such an extent that the base layer stack extends, in the direction of growth, at most to the underside of the first auxiliary layer.
[0084] In this second variant, selective, lateral etch-back of the second auxiliary layer in the region of the window is preferably carried out, such that a lateral recess extending beyond the window is produced in the second auxiliary layer.
[0085] In this way, the T-shaped emitter can be deposited in the window and in the recess in the second auxiliary layer in a self-aligning manner, wherein the width of the lateral overlap of the emitter and the base connection region, beyond the lateral extension of the window, results in a self-aligning manner due to the width of the etch-back.
[0086] The second variant of the method is subsequently continued in advantageous manner with the following steps:
removing the third auxiliary layer and covering the emitter with a fourth auxiliary layer, structuring the second and fourth auxiliary layers in such a way that they are only present in the region of the desired base connection region, etching back the first auxiliary layer underneath the second auxiliary layer, to such an extent that the side wall of the base is exposed, and producing the base connection region by selective epitaxial growth.
[0091] In this embodiment, only part of the base connection region is initially grown by selective epitaxial growth, after which the vertical distance between the insulating layer and the second auxiliary layer is increased by isotropic etching, so that the remaining part of the base connection region is produced by selective or differential epitaxy. It is possible in this way to achieve a greater outward layer thickness for the base connection than in the inner region, as a result of which the resistance of the base connection region can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0092] Further features and advantages of the invention can be seen from the following description of embodiments, with reference being made to the Figures, in which:
[0093] FIG. 1 shows a cross-section of a vertical bipolar transistor produced using double-polysilicon technology in accordance with the prior art.
[0094] FIG. 2 shows the cross-section of a vertical bipolar transistor produced in single-polysilicon technology in accordance with the prior art.
[0095] FIG. 3 shows a cross-section of a vertical bipolar transistor produced using vertically insulated monocrystalline base connection region technology in accordance with the prior art.
[0096] FIG. 4 shows a cross-section of a vertical bipolar transistor according to the prior art in US 2005 006724.
[0097] FIG. 5 shows a cross-section of a first embodiment of a vertical bipolar transistor according to the invention.
[0098] FIGS. 6-12 show cross-sections of the vertical bipolar transistor in FIG. 5 in different stages of an embodiment of a method for its production.
[0099] FIG. 13 shows a cross-section of a second embodiment of a vertical bipolar transistor according to the invention.
[0100] FIGS. 14-20 show cross-sections of the vertical bipolar transistor in FIG. 13 in different stages of an embodiment of a method for its production.
[0101] FIG. 21 shows a cross-section of an alternative configuration of the second embodiment of the of a vertical bipolar transistor according to the invention.
DETAILED DESCRIPTION
EXAMPLE 1
[0102] A first embodiment of a semiconductor device comprising a vertical bipolar transistor, in which the overlap between the emitter contact and the base connection region is produced self-aligningly with respect to the emitter window, shall now be described with reference to FIG. 5 , which shows a cross-sectional view of this first embodiment.
[0103] In this example, a vertical NPN bipolar transistor is produced on a high-impedance, monocrystalline P conductive type Si substrate 410 . However, the arrangement described here is not limited to P conductive type Si substrates. The essential features can also be applied to substrates of the opposite conductivity type. CMOS transistors may also be simultaneously present on substrate 410 , but are not shown in FIG. 5 .
[0104] The vertical NPN bipolar transistor shown in FIG. 5 comprises an N conductive type lower collector region 420 , which forms a first vertical portion of a collector of the bipolar transistor, and a likewise N conductive type emitter 460 . The collector is laterally connected via a collector connection region 421 to a collection contact region 422 . Contact structures such as the emitter-base and collector contact are not shown graphically in FIG. 5 for the sake of simple presentation.
[0105] A monocrystalline layer stack is disposed between emitter 460 and the lower collector unit 420 , said stack containing an upper collector region 405 as a second vertical portion of the collector, a base layer stack 407 consisting of a buffer layer 407 a and base layer stack 407 b, and a cap layer 408 .
[0106] The second vertical portion of collector 405 is produced by selective epitaxial growth on collector 420 in the region of a window in insulating layer 430 and may have a thickness of 5 nm to 200 nm, preferably 60 nm to 150 nm. The second vertical portion 405 is n-doped in an inner region 406 . Outside inner region 406 , the second vertical portion 405 is weakly n-doped or weakly p-doped. The n-doping in inner region 406 is produced by ion beam implantation. The inner region is also referred to as a “SIC region”.
[0107] Base layer stack 407 initially contains a buffer layer 407 a. This layer may be 5 nm to 120 nm, preferably 30 nm to 70 nm thick. The p-doped base layer 407 b is produced above the buffer layer. The thickness of the base layer may be 5 nm to 100 nm, preferably 10 nm to 50 nm. Above the base layer stack lies a cap layer 408 that is preferably 5 nm to 100 nm, preferably 10 nm to 50 nm thick, which is likewise produced by selective epitaxial growth.
[0108] Base 407 can preferably be provided in the form of a SiGe alloy. Carbon may also be incorporated in buffer layer 407 a, in base layer 407 b or in cap layer 408 during epitaxy.
[0109] A polycrystalline layer comprising base connection regions 432 and 431 adjoins layers 407 and 408 laterally outwards. The inner base connection region 432 ensues during epitaxial growth of layers 407 and 408 and has a lateral extension of 5 nm to 150 nm and a vertical extension of 5 nm to 150 nm. The outer base connection region 431 has a thickness of 20 nm to 200 nm, preferably 50 nm to 150 nm.
[0110] A first type of insulation region 411 , referred to hereinafter as field insulation regions, projects into the interior of the substrate and laterally bounds the lower collector 420 . “Shallow trench” isolations are used, such as those known from CMOS technology. These are preferably trenches with a depth of 250 to 600 nm, which may be filled with silicon dioxide (SiO 2 ), for example, or also with a combination of insulator material and polysilicon. Alternatively, field insulation regions produced by local oxidation (LOCOS) may also be used. In addition to the shallow field insulation regions, deep trenches filled with SiO 2 , for example, can be used, although these are not provided in the arrangement shown in FIG. 5 .
[0111] The first insulating layer 430 is 20 nm to 200 nm thick and lies partly on insulation region 411 and partly on collector 420 . The insulation layer preferably consists of an insulator material with a low dielectric constant. Silicon dioxide (SiO 2 ), or a different “low-k” material may be used for this purpose.
[0112] A second structured insulating layer 451 is provided above the layer stack consisting of first insulating layer 430 and base connection region 431 . This may preferably consist of a SiO 2 layer with a thickness of 10 nm to 150 nm, preferably 30 nm to 120 nm. However, it may also be composed of a combination of different insulator materials.
[0113] An approximately L-shaped spacer 450 consisting of insulation material ensures the electrical insulation of emitter 460 from base connection region 431 and 432 . The exact profile of the spacer is not exactly L-shaped, as can be seen from the Figures. The spacer could also be described, somewhat more precisely, as Z-shaped or as double L-shaped, but is referred to here as L-shaped, in accordance with the custom in the art, without confining it thereby to an exact L-shape.
[0114] The opening formed by spacers 450 above cap layer 408 defines the emitter window 462 . A highly doped silicon layer of the same conductivity type as the collector, the NPN emitter layer 460 , covers the emitter window, spacers 450 and insulator layer 451 . The NPN emitter layer 460 may be deposited as a polycrystalline, amorphous, partially monocrystalline, partially polycrystalline or as a monocrystalline material and in its final state is polycrystalline, monocrystalline or is polycrystalline or monocrystalline in subregions. During a high-temperature step, n-dopant may be diffused out of the highly doped NPN emitter layer 460 through the emitter window into cap layer 408 , as indicated by an arcuate line in cap layer 408 directly below the emitter. In this case, the emitter comprises the NPN emitter layer 460 and the diffused n-region.
[0115] In a silicidation step that then follows, silicide layers with even better conductivity compared to highly doped Si are formed. In a final step, the surface of the transistor and insulation regions is covered with an insulator layer or combination of insulator layers. Contact holes filled with conductive material, and metal strips lying above them provide the electrical connection to the contact regions of the transistor.
[0116] A method for producing the inventive semiconductor device, as described above in said example, shall now be described with reference to FIGS. 6 to 12 .
[0117] A substrate 410 ( FIG. 6 ), preferably monocrystalline p-conductivity type silicon with a high ohmic resistance (slight p-type doping), forms the basis for production. Processing of substrate 410 begins by generating field insulation regions 411 . In the present example, “shallow trenches” are used as field insulation regions. Islands of Si regions created between the field insulation regions form active regions. When the vertical bipolar transistor has been completed, the active region will accommodate collector region 420 , collector connection region 421 and collector contact region 422 .
[0118] Collector region 420 is doped by ion implantation into the silicon after the field isolation regions have been completed.
[0119] FIG. 6 shows a snapshot during production of the bipolar transistor. Field insulation regions 411 and collector region 420 have already been made. A layer stack, consisting in this embodiment of an insulation layer 430 which forms a second insulation region, a semiconductor layer 431 , a further insulation layer 401 , a first auxiliary layer 402 and a second auxiliary layer 403 , has also been produced and covers the entire wafer. Insulation layer 401 preferably consists of SiO 2 and has a thickness of 20 nm to 200 nm, preferably 80 nm to 120 nm. Semiconductor layer 431 preferably consists of polycrystalline, p-doped silicon and has a thickness of 20 nm to 200 nm, preferably 80 nm to 120 nm. Insulation layer 401 preferably consists of SiO 2 and has a thickness of 10 nm to 100 nm, preferably 30 nm to 70 nm. The first auxiliary layer 402 preferably consists of Si 3 N 4 and is 100 nm to 200 nm, preferably 130 nm to 170 nm thick. The second auxiliary layer 403 preferably consists of SiO 2 and is 150 to 250, preferably 170 nm to 210 nm thick. It should be noted, for all layer thicknesses, that they cannot be selected independently of each other or of other process parameters, especially those of etching processes.
[0120] In one variant of the invention, the second auxiliary layer 403 may be dispensed with in favor of a greater layer thickness of the first auxiliary layer 402 . The initial layer thickness of the first auxiliary layer should then take into account the rate of removal of the first auxiliary layer in an etching process, described below, to form a window 400 , and in an etching process to form a lateral recess in the first auxiliary layer in the region of the window. However, it is assumed for the following description that a second auxiliary layer 403 is present.
[0121] A window, referred to in the following as a transistor window, and structured in a standard photolithographic process, is produced with the aid of standard anisotropic dry etch processes in layers 403 , 402 , 401 and 431 . Ideally, the final dry etch process is designed in such a way that layer 431 is selectively etched to SiO 2 and that etching therefore stops at insulating layer 430 .
[0122] Inside the transistor window, spacers 404 , preferably consisting of Si 3 N 4 , are produced by layer deposition and subsequent anisotropic dry etching. The moment immediately after the spacers have been made is shown in FIG. 7 . The spacers are 50 nm to 130 nm wide, preferably 70 nm to 110 nm.
[0123] In the region of the transistor window, the second insulation region 430 is now opened as well. This is preferably done with a combination of dry and wet chemical etching. Dry etching removes the major part of the material anisotropically. The surface of the silicon of collector 420 is then exposed by wet chemical etching. Wet chemical etching is preferable here because it is particularly gentle on the silicon surface when exposing it, due to high selectivity and the absence of any damage caused by ionizing radiation.
[0124] It is possible to produce the layer 430 to be opened from a layer stack consisting of two layers, wherein the combination of layer materials and etchant are chosen such that a lower of the two layers has a higher etching rate than an upper of the two layers in the wet chemical etching process being used. In this case, isotropic wet chemical etching produces a profile as indicated in FIG. 8 . In this profile, the opening in layer 430 widens in the downward direction, i.e., in a direction toward the substrate interior. This profile may have advantages for the finished transistor, in the form of lower collector resistance and lower collector-base capacitance.
[0125] It should be noted at this point that auxiliary layer 403 is likewise affected by etching of layer 430 , and that layer removal must be taken into account when adjusting the initial layer thickness.
[0126] The next step is to produce a monocrystalline semiconductor layer 405 on the exposed silicon surface of the collector in the region of the transistor window opening by selective epitaxial growth. Said layer is 5 nm to 200 nm, preferably 60 nm to 150 nm thick. Selective growth means that no material is deposited on the materials of which spacers 404 and auxiliary layer 403 consist.
[0127] An inner region 406 of layer 405 is doped with n-type dopant by ion beam implantation. FIG. 8 shows a snapshot of this stage in production. An outer region adjacent the n-doped inner region is preferably weakly n-doped or weakly p-doped in order to achieve advantages with regard to capacitance. This doping is typically performed at the same time as layer 405 is deposited.
[0128] In a wet chemical etching process, spacers 404 are now partly removed from the side wall of semiconductor layer 431 facing toward the inner side of the window. In a lower region of semiconductor layer 431 , the spacers are entirely removed in this step. To allow this to happen, it is possible to choose the thickness of grown layer 405 , for example, or to retract its surface later, in such a way that the spacers are also attacked from below in an etching process.
[0129] In a following step of selective epitaxial deposition of base layer stack 407 and of cap layer 408 , a polycrystalline inner base connection region 432 is simultaneously created that connects the outer base connection region 431 to base 407 b. The stage in production after epitaxial deposition is shown in FIG. 9 .
[0130] In a wet chemical etching process that now follows, spacers 404 are completely removed, and auxiliary layer 402 is laterally removed to produce a recess between layers 401 and 403 . The depth of this recess in the lateral direction, which can be adjusted by varying the duration of the etching process, determines the later overlap of emitter contact 460 and base connection region 431 . The overlap is therefore positioned self-aligningly with respect to the other regions of the bipolar transistor produced in the transistor window. FIG. 10 shows a snapshot after the epitaxial deposition process.
[0131] Inside the transistor window, spacers consisting of a first spacer layer 450 and a second spacer layer 409 are now produced once again by layer deposition and subsequent, mainly anisotropic etching. The last etching step, which exposes the surface of cap layer 408 , is preferably effected by wet chemical etching in order to protect the surface of cap layer 408 .
[0132] The material of the second spacer layer 409 should be chosen such that it can later be selectively removed to the first spacer layer 450 in an isotropic etching process. The second spacer layer 409 is an auxiliary layer that produces the L-shape of the first spacer layer 450 , which is advantageous for the function of the bipolar transistor. The first spacer layer 450 preferably consists of SiO 2 and is 20 nm to 80 nm, preferably 50 nm to 70 nm thick. The second spacer layer 409 preferably consists of Si 3 N 4 and is 50 nm to 130 nm, preferably 70 nm to 110 nm thick. The moment after wet chemical exposure of the surface of cap layer 408 is shown in FIG. 11 .
[0133] The second spacer layer 409 is now removed in a wet chemical etching process. An n-doped semiconductor layer is then deposited that later forms emitter 460 . Deposition may be carried out either as selective deposition of a monocrystalline layer, as deposition of a polycrystalline layer, as differential deposition producing a monocrystalline material on cap layer 408 and polycrystalline material on all other regions, or as differential deposition producing monocrystalline material on cap layer 408 and amorphous material on all other regions. In the case of purely polycrystalline or differential deposition, material deposited outside the transistor window on auxiliary layer 403 is removed immediately after deposition by chemical-mechanical polishing (CMP). Auxiliary layer 403 is also removed by the CMP step and the following etching steps for cleaning the wafer surface. This moment in production is shown in FIG. 12 .
[0134] The following steps are now needed to finish the transistor in the form shown in FIG. 5 .
[0135] Auxiliary layer 401 , insulating layer 401 and base connection region 431 are firstly structured with the aid of a photolithographically produced photoresist mask in such a way that the base connection region obtains its final form. This structuring is effected using standard dry etch processes.
[0136] In a further step, auxiliary layer 402 is selectively removed to the exposed SiO 2 and Si layers in a wet chemical etching process.
[0137] Finally, insulating layer 401 is then removed from the surface of the base connection region and insulating layer 430 is removed from the surface of collector contact region 422 in a preferably anisotropic dry etch process that removes the SiO 2 as selectively as possible with respect to the exposed silicon regions, such as that of the emitter.
[0138] In the rest of the procedure, the bipolar transistor is finished by producing a high level of n-doping (not shown) in the region of collector contact region 422 , preferably by ion beam implantation, by production of a silicide (not shown) to reduce parasitic resistances on the emitter, base and collector contact regions (not shown), and finally by producing contacts in the form of metal contacts (not shown) that connect the bipolar transistor to a system of external conducting lines separated from it by an insulating layer.
EXAMPLE 2
[0139] A second embodiment of a semiconductor device according to the invention, comprising a vertical bipolar transistor in which the overlap between the emitter contact and the base connection region is produced self-aligningly, and in which the base connection region consisting of a different material from that used in the inner transistor may be wholly or partially monocrystalline, shall now be described with reference to FIG. 13 and FIG. 21 . FIG. 13 shows a cross-sectional view of this second embodiment. FIG. 21 shows a variant of the second embodiment. In FIGS. 13 to 21 , which pertain to the two variants of Example 2, the same reference signs are used for the same structural elements as in Example 1 and FIGS. 5 to 12 .
[0140] The structure of the vertical bipolar transistor in this second embodiment is identical in many respects and in both variants to that of the first embodiments, with the exception of the following structural features:
There is no inner polycrystalline portion of the base connection region, which is marked with reference sign 432 in the embodiment shown in FIG. 5 . In the embodiment shown in FIG. 13 , base connection region 431 directly adjoins base layer stack 407 . Base connection region 431 is monocrystalline. In the variant of the Example shown in FIG. 18 , however, the base connection region is only partially monocrystalline. A first region 431 a laterally and directly adjoining base stack 407 is monocrystalline, and a second region 431 b laterally adjoining region 431 a is polycrystalline. The monocrystalline region may be produced by epitaxial growth or by amorphous deposition with subsequent thermal treatment. In the variant shown in FIG. 21 , the base connection region may be embodied in such a way that the second region 431 b has a greater thickness than region 431 a, which advantageously reduces the electrical resistance. The base connection region, in particular the monocrystalline region, may be produced from a different material from the one used in semiconductor layer 405 , in base stack 407 or in cap layer 408 . In contrast to known embodiments according to the prior art, this provides an advantage when selecting a material which is suitable with regard to the electrical function of the transistor.
[0146] A method for producing the inventive semiconductor device, as described above in said example, shall now be described with reference to FIGS. 14 to 20 .
[0147] A substrate 410 ( FIG. 14 ), preferably monocrystalline p-conductivity type silicon with a high ohmic resistance (slight p-type doping) forms the basis for production. Processing of substrate 410 begins by producing field insolation regions 411 . In the present example, “shallow trenches” are used as field isolation regions. Islands of Si regions created between the field isolation regions form active regions. When the vertical bipolar transistor has been completed, the active region will accommodate collector 420 , collector connection region 421 and collector contact region 422 .
[0148] The doping of collector 420 is performed by ion implantation into the silicon after the field isolation regions have been completed.
[0149] FIG. 14 shows a snapshot during production of the bipolar transistor. Field isolation regions 411 and the lower vertical portion 420 of the collector have already been made. A layer stack consisting of insulating layer 430 , a first auxiliary layer 441 , a second auxiliary layer 442 and a third auxiliary layer 443 has also been produced. Insulating layer 401 preferably consists of SiO 2 and is 20 nm to 150 nm, preferably 80 nm to 120 nm thick. The first auxiliary layer 441 preferably consists of Si 3 N 4 and is 20 nm to 150 nm, preferably 50 nm to 120 nm thick. The second auxiliary layer 442 preferably consists of SiO 2 and is 50 nm to 250 nm, preferably 130 nm to 170 nm thick. The third auxiliary layer 443 preferably consists of Si 3 N 4 and is 50 nm to 100 nm, preferably 60 nm to 80 nm thick.
[0150] A window defined by a photolithographic process is now produced in layers 443 , 442 , 441 and 430 ; cf. FIG. 15 . This is preferably done using standard anisotropic dry etch methods, except for removal of the lowermost regions of layer 430 , which are removed as gently as possible with a wet chemical etching method from the monocrystalline region 420 , the lower, first vertical portion of the collector. Analogously to Example 1, the profile may be adjusted thereby in such a way that the transistor window widens toward the substrate.
[0151] At this point, auxiliary layers 441 and 443 may optionally be drawn back with a further wet chemical etching process if they project significantly further into the transistor window than layers 430 and 442 .
[0152] The monocrystalline semiconductor layer 405 , base stack 407 and cap layer 408 are now produced by selective epitaxial growth in the region of the transistor window on the first vertical portion 420 of the collector; cf. FIG. 16 . This growth can be interrupted in the meantime in order to implant SIC region 406 . However, it is also possible to implant the region through the grown base stack at a later stage. In the present embodiment, SIC region 406 is not drawn in until later, in the stage shown in FIG. 18 , but without excluding the variant of earlier implantation as described.
[0153] At this point, auxiliary layer 442 is drawn back laterally by a wet chemical etching process so that a recess is created between layers 441 and 443 ; cf. FIG. 17 . The lateral extension of this recess, which can be adjusted for a given etchant by varying the duration of the etching process, determines the later lateral extension of the overlap between emitter contact 460 and base connection region 431 . The lateral extension of this overlap is therefore self-aligningly positioned with respect to the transistor window and therefore to the other regions of the bipolar transistor produced in the transistor window.
[0154] L-shaped spacers 450 and emitter 460 are now produced analogously to Example 1, in that one space consisting of a SiO 2 and a Si 3 N 4 layer is firstly produced at the inner wall of the transistor window, the Si 3 N 4 is removed and emitter 460 is produced as polycrystalline, monocrystalline or partly monocrystalline and partly polycrystalline, either by selective growth or by a combination of polycrystalline deposition or differential deposition with a CMP step. Auxiliary layer 443 is then removed. This moment in production is shown in FIG. 15 .
[0155] The next step is the deposition of an auxiliary layer 444 , preferably consisting of SiO 2 and 30 nm to 100 nm, preferably 40 nm to 60 nm thick. With the aid of a photolithographically structured photoresist mask, layers 444 and 442 are structured by standard dry etch methods in such a way that they defined the shape of the subsequent base connection region. Auxiliary layer 441 is now laterally removed from under layer 442 , selectively with respect to all the other layers present, and preferably by wet chemical etching, until the side wall of base layer stack 407 is exposed. The state is shown in FIG. 19 .
[0156] Base connection region 431 is now produced. This is preferably done by selective epitaxial growth. However, it can also be produced by depositing an amorphous layer which is made crystalline by thermal treatment. This production state is shown in FIG. 20 .
[0157] Another variant for the design of the base connection region is shown in FIG. 21 . After producing a first, monocrystalline region 431 a of the base connection region, the distance between layers 430 and 442 may be increased by isotropic etching before a further region 431 b is produced, which may be monocrystalline or polycrystalline.
[0158] If the base connection region was not produced exclusively by selective methods, the silicon which is produced outside the actual base connection region is removed in a next step by a dry etch process, which removes the silicon selectively with respect to SiO 2 . During this etching, the base connection region thus remains protected by layer 442 , which serves as a mask during the etching process.
[0159] In a subsequent etching process that removes SiO 2 selectively with respect to silicon, the SiO 2 layers covering the emitter, base and collector contact areas are removed. A cross-section as shown in FIG. 13 is obtained by said process.
[0160] The bipolar transistor is finally completed by producing a high level of n-doping in the region of collector contact 422 , preferably by ion beam implantation, by production of a silicide to reduce parasitic resistances on the emitter, base and collector contact regions, and finally by producing contacts in the form of metal contacts that connect the bipolar transistor to a system of external conducting lines separated from it by an insulating layer.
[0161] Other variants of the method besides those described above are possible, of course. In one variant, for example, the structures are rotated relative to conventional deposition by 45 degrees about an axis perpendicular to the surface of the substrate, thus providing advantages in the selective growth of Si, which ultimately improves the high-speed characteristics of the bipolar transistor as well.
[0162] In addition to bipolar transistors, the semiconductor device may also contain other semiconductor components produced with MOS or CMOS technology. The above description of the Figures was limited to the example of NPN bipolar transistors. However, the invention is not limited to those. A bipolar transistor of a semiconductor device according to the invention may be executed either as an NPN or as a PNP transistor. When selecting the material for the inner transistor and the base connection region, a person skilled in the art can look up the material parameters for electron and hole mobilities of potential semiconductor materials, which are published in standard reference works.
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A semiconductor device, comprising a substrate layer made of a semiconductor material of a first conductivity type and having a first insulation region, and a vertical bipolar transistor having a first vertical portion of a collector made of monocrystalline semiconductor material of a second conductivity type and disposed in an opening of the first insulation region, a second insulation region lying partly on the first vertical portion of the collector and partly on the first insulation region and having an opening in the region of the collector, in which opening a second vertical portion of the collector made of monocrystalline material is disposed, said portion including an inner region of the second conductivity type, a base made of monocrystalline semiconductor material of the first conductivity type, a base connection region surrounding the base in the lateral direction, a T-shaped emitter made of semiconductor material of the second conductivity type and overlapping the base connection region, wherein the base connection region, aside from a seeding layer adjacent the substrate or a metallization layer adjacent a base contact, consists of a semiconductor material which differs in its chemical composition from the semiconductor material of the collector, the base and the emitter and in which the majority charge carriers of the first conductivity type have greater mobility compared thereto.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT Application No. PCT/US2008/088489, filed Dec. 29, 2008, and U.S. patent application Ser. No. 12/345,610, filed Dec. 29, 2008, both of which claim priority to U.S. Provisional Patent Application No. 61/017,473, filed Dec. 28, 2007, all of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to an impact bed for a conveyor belt and, more particularly, to impact bed assemblies that are conventionally known as static and dynamic-type impact beds.
BACKGROUND OF THE INVENTION
Conveyor belts are used in a variety of industries to transport goods and materials from one place to another. Generally, goods are deposited at one end of a conveyor and are transported to the other end, where they are discharged or otherwise removed from the conveyor belt. The belts used are often robust, but are susceptible to damage from a variety of sources. While the discharge of the goods from a conveyor belt does not usually cause damage to the belt, the act of depositing goods and materials onto a conveyor belt has the potential to cause damage. In this regard, when a belt is being used to transport coal, aggregate and other coarse and heavy material, the deposit of these types of rocks onto the belt can generate tremendous impact forces on the belt. For instance, with a 100 lb mass having drop distance of 10 feet from a discharge chute onto a conveyor belt, there is 1,000 ft-pounds of force impacting the belt.
An impact bed is an apparatus which is installed below the area of a conveyor belt on which heavy loads are deposited for absorbing the impact forces generated thereby, as discussed above. Generally, impact beds can be classified as either static or dynamic. Static impact beds have resilient impact bars and an underlying bed framework that includes rigidly connected frame members. For instance, static impact beds typically include at least two support members for supporting the resilient impact bars thereon with the support members extending from either side of the belt inwardly and toward the middle of the belt. The support members are rigidly secured on cross members that span the width of the belt to be rigidly secured to stringers of the conveyor belt frame.
By contrast, dynamic impact beds differ from static impact beds in the manner in which impact forces are absorbed since, rather than using resilient impact bars, dynamic impact beds have torsion bias units mounted under an impact cradle upon which the belt is supported. In this regard, unlike static beds, the bed framework underlying the impact cradles includes frame members resiliently connected together via the torsion bias units secured therebetween.
Generally, there is a trade off between increasing the capacity of the bed to absorb impact forces, such as by using thicker impact bars with static impact beds, and the size of the impact bed. In other words, an impact bed having a compact size for fitting under the belt generally sacrifices in its ability to absorb high impact forces. Given that an impact bed is meant to be installed under the upper or carry run of a belt, a location often without an excess of space, balancing the size and strength of the bed is important. Generally, the vertical height between the carry run of the belt and the upper surface of the conveyor frame stringer member currently is approximately 8.5 to approximately 9.0 inches and cost constraints may tend to shrink the size of this space even further.
In typical static impact beds, several sets of support members will be longitudinally spaced from each other under the area of the belt where materials are deposited thereon for being conveyed thereby. The longitudinally spaced support members have the resilient bars secured thereto to extend thereacross running lengthwise in the belt travel direction and which are operable to absorb the impact forces and to decrease the acceleration of the materials or rocks dropped onto the belt. The resilient bars are subject to wear and damage over repeated impacts with the belt and thus need to be serviced and/or replaced on a regular basis.
In many static impact beds, servicing of the impact bars, particularly for those in the lower central area under a troughed belt, requires that the loading on the impact bed by the heavy conveyor belt thereon be relieved. This allows an operator to unfasten the support members from the cross members so that the support members and impact bars thereon can be removed out from under the belt for servicing.
In some prior static impact beds, the support members upon which the impact bars are secured can be slid in and out from under the conveyor belt along the cross members. However, when the support members are slid out from under the conveyor belt, the relatively heavy support members and impact bars thereon, e.g. approximately 100 to 200 lbs., must be supported, such as by heavy equipment like a crane or other lifting or support mechanism, which allows an operator to safely replace the impact bars.
In prior static impact beds, the support members are secured in their operative positions under the belt by being bolted to the cross members. This requires that an operator reach or climb under the belt to access the bolt locations, which can be of particular difficulty when the bolting needs to occur centrally under a troughed belt at which the belt is at its lowest height and where there is very little work space available between the upper and lower runs of the belt. Similar problems are presented when servicing of the impact bed is necessary and the securing bolts need to be removed.
Thus, prior static impact beds suffer from problems with optimizing size of the bed and their impact absorption capacity, and from difficulty in servicing the resilient impact bars.
Known dynamic impact beds differ from static beds by the provision of torsion bias units, such as Rosta mounts, between the cross members and the upper impact cradles of the beds. In one known dynamic impact bed, the Rosta mounts are secured on elevated platforms extending up from the cross member and connected to outer ends of the support members thereover. In another known dynamic impact bed, a pair of Rosta mounts are linked together, with the lower unit secured to the cross member and the upper unit secured to the impact cradle. In both instances, the profile of the dynamic impact bed above the cross members is undesirably increased due to the location of the Rosta mounts under the belt and over the cross members. In this regard, the impact cradles typically need to have a very low profile and thus utilize low profile impact plates that engage under the belt instead of the thicker, resilient impact bars used with static impact beds.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, an impact bed assembly is provided that provides simpler and easier replacement of impact bars connected to the support members of the impact bed assembly. In this regard, the impact bed assembly has a slide interface between a cross member and a support member for allowing the support member, with impact bars mounted thereon, to translate along the cross member from an operative position under the belt to a predetermined service position on the cross member at which the impact bars can readily be serviced. In the predetermined service position, the support member and impact bars thereon are still securely supported on the cross member thus allowing an operator to replace the impact bars by only sliding the support member out from under the belt to the predetermined service position. In this manner, the securely supported support member on the cross member when in the service position permits safe and easy changing of the impact bars without the need for employing heavy equipment to support or lift the support member for servicing of the impact bars thereon. Accordingly, the slide interface and predetermined service position provided for the present impact bed assembly allows for easier and faster servicing of the impact bars in terms of shifting of the support member in a direction out from under the belt, replacement of the impact bars connected thereto, and shifting of the support member back to its operative position.
Preferably, there are multiple support members that are spaced in the longitudinal, belt travel direction and which have the impact bars extending transversely thereacross and rigidly secured thereon to form one of two identical side impact bed subassemblies that are slid on corresponding cross members from either side of the belt. The support members and impact bars are configured to remain securely upright on the cross members when in the predetermined service position. In particular, when in the predetermined service position the center of mass of the combined mass of the interconnected support members and impact bars is located vertically above the cross members laterally inward from the outer ends thereof so that the support members and resilient bars are securely balanced on the cross members and will not tip over the ends of the cross members.
The predetermined service position can be defined by stops between the cross members and abutment portions of the support members so that when stop members are engaged with the abutment portions, the side impact bed subassemblies are in their predetermined service positions. Further, once in the above-described predetermined service position, the subassemblies can be shifted slightly back toward their operative positions so that the stop members and abutment portions are slightly spaced from each other with apertures of the support members and cross members aligned to allow the subassemblies to be positively secured or fixed to the cross members as by bolting to resist any shifting of the support members while the impact bars are being replaced in a preferred predetermined service position of the subassemblies. Manifestly, the apertures also may be arranged in the support members and cross members so that they are aligned with the stop members and abutment portions engaged.
In another aspect, an impact bed assembly is provided for a troughed belt and has support members that can be slid on underlying cross members to an operative position under the belt via an outer slide interface between the support members and the cross members. However, rather than having to reach or climb under the belt to bolt inner portions of the support members to inner portions of the cross members in the operative position generally under a lowered, central area of the troughed belt so that the greater impact loads received thereat are transferred from the impact bars secured to the support members to the cross members bolted thereto, the present impact bed assembly has automatically operable inner load bearing mechanisms. The inner load bearing mechanism is automatically operable to transfer loading once the support members are slid to their operative positions without the need for bolting thereof to the cross members. This makes the installation of the support members and impact bars easier and faster than the prior bolted support members and cross members.
In another aspect, an impact bed assembly is provided that provides additional capacity for impact absorption without increasing the height of the impact bed assembly. In this regard, the impact bed assembly includes resilient impact bars each having an elongate resilient body and a backing plate connected under the resilient body with the backing plate having depending legs extending away from the resilient body and being configured to be mounted on rigid mounting pads spaced along the support members. In this manner, the depending legs of the backing plate do not restrict the compression of the resilient body as impact forces are absorbed thereby so as to maximize the impact absorption capacity of the resilient impact bars. Further, the spacing of the pads along the support members and gaps provided therebetween into which the depending legs are fit minimize the height of the impact bed assembly.
In another aspect of the invention, a dynamic impact bed assembly is provided that has increased impact absorption capacity over prior dynamic impact bed assemblies without requiring an increase in profile thereof and thus more space therefor under the belt. In prior dynamic bed assemblies, a cross member is rigidly connected to the conveyor frame structure and has a support member for an impact cradle resiliently mounted thereto so that the cross member generally provides a floor that limits the potential downward movement of the support members upon the application of impact forces thereto. Since the space between the conveyor frame members or stringers to which the cross member is secured is typically only approximately 8.5 to approximately 9.0 inches in vertical height, the vertical space for prior dynamic bed assemblies has been even further limited due to the fixed cross beams on the stringers.
Instead of rigidly mounting the cross members to conveyor frame members, the cross members of the preferred dynamic bed assemblies herein are incorporated in a dynamic frame assembly that is mounted to the conveyor frame members via resilient mounts so that the entire dynamic frame assembly including the cross members shifts downwardly when impact forces are received thereby. In this manner, the movement of the dynamic frame assembly is only limited by the freedom provided by the resilient mounting mechanisms, as there are no structural members rigidly connected to the conveyor frame structure extending below the dynamic frame assembly to limit the downward movement thereof. This allows the preferred dynamic bed assemblies to utilize more of the space between the carry and return runs of the conveyor belt which includes not only the space between the upper belt run and the upper surface of the stringers, but also the height of the stringers themselves, e.g. approximately 6 inches to approximately 8 inches.
In another aspect, the present dynamic impact bed assembly has bed frame members or support members that are resiliently mounted to the conveyor frame structure via outer resilient torsion mounts therebetween. The resilient torsion mounts are preferably located laterally beyond the support members. In this manner, when impact forces are taken by the dynamic impact bed assembly causing the support members to resilient shift downward, the outer resilient torsion mounts do not interfere with the range of resilient downward shifting that can be provided thereby. Accordingly, the range of travel for the dynamic impact bed assembly provided by the torsion mounts can be maximized. In addition, since space under the belt is not needed for the outer resilient torsion mounts, impact bars having relatively thick bodies of resilient material, e.g. approximately 3.0 to 4.5 inches thick, and preferably 3.5 to 4.5 inches thick, such as typically used in static impact bed assemblies, can be employed in the present dynamic impact bed assembly to further maximize the impact absorption capacity provided thereby.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an impact bed assembly showing the conveyor belt in phantom supported on impact bars extending thereunder with the impact bars secured to support members and the support members secured on cross members;
FIG. 2 is an end elevational view of another, larger impact bed assembly having a greater number of impact bars for larger width belts and showing one of the cross members mounted to conveyor frame structure on either side of the conveyor belt;
FIG. 3 is an enlarged elevational view of the impact bed assembly of FIG. 2 showing in phantom depending fin projections of the support members in their operative positions on the cross-member with pins of the cross member engaged in notches of the fin projections;
FIG. 4 is an elevational view similar to FIG. 3 but showing the smaller impact assembly of FIG. 1 with one of the support members slid to a predetermined service position on the cross member;
FIG. 4A is a perspective view of the impact bed assembly of FIG. 4 showing a pair of identical side impact bed subassemblies each including multiple support members and impact bars secured thereon with one of the subassemblies slide to the predetermined service position with a securing fastener connecting one of the support members of the assembly to the cross beam thereunder;
FIG. 5 is a perspective view showing a cross member having transverse, end mounting brackets for securing the cross member to conveyor frame side members with resilient pads therebetween;
FIG. 5A is a perspective view of the cross member of FIG. 5 having the mounting brackets reversed when resilient pads are not used;
FIG. 6 is an enlarged, perspective view of the mounting bracket configured as in FIG. 5 showing raised side plate portions under which the resilient pads are fastened;
FIG. 7 is a perspective view of the cross member;
FIG. 8 is a side elevational view of the cross member;
FIG. 9 is side elevational view of the support member showing a lowered central portion and an outer lateral portion having an inclined configuration up from the central portion;
FIG. 10 is a perspective view of the support member of FIG. 9 showing raised pad members spaced therealong;
FIG. 11 is a perspective view of the underside of one the impact bars showing an elastomeric body, a hard covering including a tapered upstream end, a rigid insert, and a backing plate with depending legs with notches for receiving the pad members of the support members;
FIG. 12 is an a fragmentary perspective view of one of the side impact bed subassemblies showing the resilient impact bars secured on the support member with the legs of the backing plates extending down into gaps between the spaced raised pads of the support member;
FIG. 13 is a plan view of an anti-rotation washer for being disposed about a polygonal portion under heads of fasteners that secure the impact bar insert to the backing plate thereof with the washer fitting between and closely adjacent to upstanding side walls of the impact bar inserts;
FIGS. 14A and 14B are perspective views of a dynamic impact bed assembly having a dynamic mounting frame including rigidly connected cross members and support members, and torsion bias units for resiliently mounting the dynamic frame to the conveyor frame members;
FIG. 14C is an end elevational view of the dynamic impact bed assembly of FIGS. 14A and 14B showing the travel range of the dynamic impact bed assembly with the bottom of the cross members capable of traveling downward from just below the top of the stringer members of conveyor frame to approximately the center thereof;
FIG. 15 is a perspective view of longitudinal beam members of the dynamic bed frame assembly including outbound mounting plates for pairs of linked torsion bias units to be mounted to the stringer members;
FIG. 16 is an enlarged perspective view of one of the pairs of linked torsion bias units showing the units being vertically offset and interconnected by diagonal link members;
FIG. 17 is a perspective view of a vibration mounting plate having the resilient pads secured thereto; and
FIG. 18 is a perspective view of another support member having a single mounting plate with fastener receiving lugs for mounting the resilient impact bars thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1-3 , static impact bed assemblies 2 are shown used for a conveyor belt 6 having a troughed configuration as provided by belt supports mounted to conveyor frame structure 4 ( FIG. 2 ), such as idler rollers, that can be located both upstream and downstream along the longitudinal, belt travel direction 13 from the impact bed assembly 2 . To accommodate the troughed configuration, the static impact bed assembly 2 includes a pair of identical side impact bed subassemblies 20 , 22 supported on cross beam members 100 under the conveyor belt 6 in the area where items are typically dropped thereon. The impact bed assembly 2 is operable to absorb the impact forces so as to avoid damage to the conveyor belt 6 in the impact receiving area thereof. For this purpose, the side bed subassemblies 20 , 22 each includes support members 200 on which resilient impact bars 300 are mounted. Although troughed belt configurations are far more common, it is conceivable that with untroughed belts only a single subassembly 20 would need to be used and it would not need outer inclined portions thereof as described hereinafter for the pair of bed subassemblies 20 , 22 .
The number and transverse spacing of the impact bars 300 as well as the sizing of the support members 200 and cross members 100 can vary as the width of the belt 6 varies. FIG. 1 illustrates a smaller impact bed assembly 2 for smaller width belts 6 , e.g. 24 inch and 30 inch wide belts, with each subassembly 20 , 22 having three impact bars 300 , while FIGS. 2-4 illustrate a larger impact bed assembly 2 for larger width belts 6 with each subassembly 20 , 22 having five impact bars 300 . It is contemplated that subassemblies 20 , 22 could carry up to seven impact bars 300 for very wide belts e.g. seventy-two inches in width. Also, for certain applications it may be desirable to have one of the subassemblies 20 , 22 carry more impact bars 300 then the other subassembly 20 , 22 .
As seen best in FIG. 9 , the support members 200 of the side bed subassemblies 20 , 22 each include a generally lowered central portion 210 configured to be positioned below the central trough portion 6 a of the belt 6 and a raised and inclined outer lateral portion 230 under inclined side portions 6 b of the belt 6 configured to generally maintain the troughed configuration of the conveyor belt 6 as the conveyor belt 6 has impact forces applied thereto. Both the lowered central and raised outer lateral portions 210 , 230 include impact bars 300 mounted thereon, as will be discussed further hereinafter.
To service and maintain the impact bed assembly 2 the support members 200 of the side impact bed subassemblies 20 , 22 each are mounted on corresponding underlying cross members 100 via a slide interface 12 therebetween. The slide interface 12 allows an operator to slide the subassemblies 20 , 22 from one side of the belt 6 in a lateral direction 11 generally orthogonal to the longitudinal, belt travel direction 13 .
As shown in FIGS. 4 and 4A , the slide interface 12 is preferably formed between upper surfaces 111 of the cross members 100 and wing portions 280 extending laterally from either side of the support members 200 at the lower end of the outer portions 230 thereof so that the lower surfaces 281 of the lateral wing portions 280 can slide along the upper surfaces 111 of the cross members 100 . The lower surfaces 281 of the lateral wing portions 280 preferably include a low friction coating, such as of a low friction plastic material, to reduce friction between the lower surfaces 281 of the lateral wing portions 280 and the upper surfaces 111 of the cross members 100 and to ease translation of the subassemblies 20 , 22 along the cross member 100 between the operative and service positions thereof.
Guide structure 60 is provided between the support members 200 and cross members 100 to guide the support members 200 along the upper surface 111 of the cross members 100 . As shown, the guide structure 60 includes guide channels 128 extending centrally along the cross members 100 , and depending fin portions 282 of the support members 100 received in the guide channels 128 . The depending fin portions 282 extend generally from forward operative abutment portions 209 located under the lower central portions 210 of the support members 200 to rearward service abutment portions 131 located at a predetermined lengthwise position below the raised outer portions 230 of the support members 200 .
As best seen in FIGS. 5 and 7 , the cross members 100 can each include a pair of adjacent channel members 700 that are connected so that their web walls 702 are spaced from each other to form the guide channel 128 therebetween. The channel members 700 have a generally C-shape cross sectional configuration so that upper and lower flanges 704 and 706 extend orthogonal to the web wall 702 thereof. The upper flanges 704 are level with each other and together form the upper surface 111 of each of the cross members 100 with each wing portion 280 of the support members 200 riding on the underlying upper flange member 704 . To provide additional strength, the channel members 700 of the cross members 100 include rib portions 124 extending between the upper and lower flanges 704 , 706 and rib portions 126 extending from the service stop members 130 to the upper flange 104 .
The side impact bed subassemblies 20 , 22 are configured to be translated along the cross members 100 between a predetermined operative position 8 and a predetermined service position 10 . The predetermined service position 10 is located so that with the subassemblies 20 , 22 slid from their operative positions 8 to their predetermined service positions 10 , the center of mass 24 of the subassemblies 20 , 22 will be located laterally inward from the outer ends 150 , 152 of the cross members 100 , as shown in FIG. 4 . As a result, the subassemblies 20 , 22 are securely balanced on the cross members 100 when shifted to their predetermined service positions. To keep an operator from shifting the subassemblies 20 , 22 too far laterally outward, a stop is formed between the cross members 100 and support members 200 . Each cross member 100 includes a pair of stop members 130 , one at either end 150 , 152 of the cross member 100 , and the support members 200 include the service abutment portions 131 at the rear of the depending fin projections 282 of the support members 200 . The service abutment portions 131 and service stop members 130 are arranged so that they will engage with one another with the subassemblies 20 , 22 slid laterally outward beyond their predetermined service positions but before the subassemblies 20 , 22 reach a point where their center of mass 24 is positioned beyond the ends 150 , 152 of the cross member 100 . In this regard, the impact bars 300 can be serviced with the stop members 130 engaged with the abutment portions 131 to form a predetermined service position thereat.
In the more laterally inward predetermined service position, the subassemblies 20 , 22 preferably are positively secured to the cross members 100 , such as by bolting. As shown in FIGS. 4 , 4 A and 5 , in the predetermined service position 10 notch openings 284 of the depending fin projections 282 correspond to and are aligned with web throughbores 134 of the cross members 100 . In addition, inner wing throughbores 290 of the wing portions 280 of the support members 200 correspond to and are aligned with upper surface throughbores 121 ( FIG. 7 ) of the cross members 100 . As shown, the notches 284 are aligned with the web throughbores 134 and the inner wing throughbores 290 are aligned with the upper surface throughbores 121 when the abutment portions 131 of the depending fin projections 282 are slightly spaced from the stop members 130 of the cross members 100 .
In the predetermined service position 10 , impact bars 300 will be vertically spaced from the conveyor belt 6 to provide an operator access to the impact bars 300 so that they can remove and replace the impact bars 300 without adjusting the conveyor belt 6 . In particular, the laterally outermost impact bars 300 will be pulled out from under the belt 6 while the inner impact bars 300 will be pulled out from under the central lower belt portion 6 a to be under the inclined belt portion 6 b . The impact bars 300 mounted on the raised outer lateral portions 230 of the support members 200 are shifted out from under the conveyor belt 6 to permit an operator to remove and replace these impact bars 300 . Further, at least one impact bar 300 mounted on the raised outer lateral portions 230 is positioned vertically above the cross members 100 . The impact bars 300 mounted on the lowered central portions 210 of the support members 200 are positioned above the cross members 100 and generally under the inclined portion of 6 b of the conveyor belt 6 , as shown in FIG. 4 . Generally, as shown in FIG. 4 , the conveyor belt 6 will maintain a trough configuration after the subassemblies 20 , 22 are translated toward the predetermined service position 10 . As a result, a vertical spacing separates the conveyor belt 6 and the upper surfaces 301 of the impact bars 300 mounted on the lowered central portions 210 that is larger than the vertical spacing when the bars 300 are in their operative position, permitting an operator to remove and replace the impact bars 300 without having to adjust the conveyor belt 6 .
The subassemblies 20 , 22 are further configured to be secured to the cross members 100 in the operative position 8 so as to transfer impact forces applied to the impact bars 300 mounted on the subassemblies 20 , 22 to the cross members 100 . In particular, the subassemblies 20 , 22 are automatically secured to the cross members 100 via automatically operable load bearing mechanisms 133 when they are slid to their operative positions. The automatically operable load bearing mechanisms 133 are positioned adjacent the centers 112 of the cross members 100 so that an operator need not reach under the lowered center 6 a of the belt 6 to secure the subassemblies 20 , 22 in the operable position 8 . As is apparent, the lowered central area 6 a of the belt receives the greatest impact loading applied to the conveyor belt 6 . Thus, the load bearing mechanisms 133 are positioned to transfer a high level of the impact loading from the impact bars 300 mounted on the support members 200 to the cross members 100 therebelow.
As previously discussed, the support members 200 include lateral wing portions 280 which ride on the upper surfaces 111 of the cross members 100 . Accordingly, the wing positions 280 also transfer impact loading received by the impact bars 300 to the cross members 100 . However, since the wing portions 280 are at the laterally outer inclined portions 230 of the support members 200 , laterally inner load bearing mechanisms such as the automatically operable load bearing mechanisms 133 herein are desirable where the impact loading is greatest on the impact bed assembly 2 . Further, the illustrated wing portion 280 are formed as lower leg portions 280 of right angle members 900 that have upright leg portions 902 welded to vertical plate portions 271 of the support members 200 . Accordingly, the laterally inner load bearing mechanisms 133 ensure most of the impact loading is transferred to the cross members 100 and then to the conveyor frame stringer members 4 thereby rather than being transferred at the welds between right angle members 900 and the support member 200 .
As shown in FIGS. 3 , 4 and 8 , the automatically operable load bearing mechanisms 133 include pins 135 extending across the guide channel 128 of the cross members 100 and the forward notch openings 284 of the abutment portions 209 of the depending fin projections 282 configured to receive the pins 135 therein. The notch opening 284 is tapered for smoothly receiving the pin 135 therein as the subassemblies 20 , 22 are slid to their operative positions so that there is an overhang portion 140 that engages and extends over the pin 135 . The tapered notch opening 284 is configured to orient the subassemblies 20 , 22 so that the pins 135 engage and bottom out in the notch opening 284 and are fully received therein thereby limiting the laterally inward translation of the subassemblies 20 , 22 . The overhang portions 140 engage on the pins 135 and transfer impact forces applied to the subassemblies 20 , 22 to the cross members 100 .
In their operative positions, the subassemblies 20 , 22 are positively secured to the cross members 100 , such as by bolting. In particular, the lateral wing portions 280 of the subassemblies 20 , 22 each include an outer lateral throughbore 291 that will be aligned with throughbores 121 of the cross members 100 to accept a bolt 292 extending therethrough. In the operative position, the support members 200 of the subassemblies 20 , 22 are further secured to the cross members 100 via outer fin throughbores 286 of each of the support members 200 aligned with the web throughbores 134 of the cross members 100 .
The cross members 100 are configured to be secured to the belt frame structure in the form of the side stringer members 4 extending parallel to the conveyor belt 6 along each side thereof for transferring the loading transferred to the cross members 100 to the belt frame stringers 4 . The cross members 100 include end mounting brackets 120 at either end 150 , 152 of the cross members 100 for mounting the cross members 100 to the stringers 4 . Preferably, the mounting brackets 120 include a central, lower portion 120 a that extends across the guide channel 128 to form the stop member 130 . The channel members 700 each include end cut-outs in their web walls 702 to form end raised portions 710 with the bracket central portion 120 a spanning and interconnecting the adjacent raised portions 710 , as seen best in FIG. 6 . In this manner, with the brackets 120 secured to the stringers 4 , the main, central portion 712 of the channel members 700 will extend down from the end raised portions 710 so that the cross members 100 are hung from the stringer members 4 to extend below the upper surfaces thereof to keep the profile of the static impact bed assembly 2 to a minimum.
The mounting brackets also preferably include a pair of upwardly extending steps 122 so that there are raised side plate portions 120 b on either side of the lowered central portion 120 a to permit resilient pads 12 a mounted to the vibration mounting plate 121 ( FIG. 17 ) to be fastened between the mounting brackets 120 and the stringers 4 without increasing the height of the impact bed assembly 2 . The resilient pads 12 a absorb impact forces transferred to the cross members 100 from the subassemblies 20 , 22 to reduce wear and damage to the conveyor belt 6 upon the application of impact forces thereto.
The impact bars 300 are configured to absorb the impact forces applied thereon to minimize any damage to the conveyor belt 6 . The impact bars 300 are mounted to the support members 200 to extend in the travel direction 13 of the conveyor belt 6 . The impact bars 300 include an elastomeric body 302 extending the length of the impact bars 300 and include a metal insert 340 therein, as shown in FIGS. 11 and 12 . The metal insert 340 includes an upper wall 348 , sidewalls 350 and spaced lower flanges 344 defining a longitudinal slot 345 extending the length of the impact bars 300 .
The impact bars 300 include backing plates 360 for securing the elastomeric bodies 302 to the support members 200 of the subassemblies 20 , 22 and maximize the impact absorption thereof. The backing plates 360 extend along the lower surface 308 of the elastomeric bodies 302 . The backing plates 360 include a series of apertures 361 extending therethrough aligned with the slot 345 of the metal insert 340 for securing the impact members 300 to the support members 200 , as will be described more fully hereinafter.
The backing plates 360 preferably include an upstanding tab 362 extending from a downstream end 363 of the backing plates 360 and generally orthogonal to the length of the impact bars 300 . The upstanding tabs 362 engage downstream ends of the elastomeric bodies 302 to resist migration of the elastomeric bodies 302 as the conveyor belt 6 travels therealong.
As shown in FIGS. 11 and 12 , the impact bars 300 further include connection mechanisms 316 to mount the elastomeric bodies 302 to the backing plates 360 and the support members 200 of the subassemblies 20 , 22 . In particular, the connection mechanisms 316 are a bolt 312 having a head portion 314 , a polygonal shank portion (not shown) and a threaded shank portion 318 . The head portion 314 is configured to be received in the space defined by the upper wall 348 , sidewalls 350 and spaced lower flanges 344 of the metal insert 340 . Further, the polygonal shank portion is configured to be received closely between the spaced lower flanges 344 so as to resist rotation of the bolt 312 . The threaded shank portion 318 , which extends from the shank portion, extends through the apertures 361 of the backing plates 360 . Further, each securing mechanism 316 includes an anti-rotation member 324 , such as a washer, having straight inner edges 328 configured to receive the polygonal shank portion therein and a flat outer edge 326 configured to engage the sidewalls 350 of the metal insert 340 to resist rotation of the bolt 312 during conveyor belt operations.
As best seen in FIG. 11 , the backing plates 360 preferably have a generally inverted U-shaped configuration including depending legs 364 extending generally orthogonally to the length of the backing plates 360 and away from the elastomeric bodies 302 . The legs 364 do not extend up alongside the elastomeric bodies 302 so as to not restrict the compression of the elastomeric bodies upon the application of impact forces thereto. Further, by not positioning the legs 364 adjacent the elastomeric body 302 debris and other particulate will not settle therebetween.
As previously discussed, the support members 200 of the subassemblies 20 , 22 have the impact bars 300 mounted thereon. As shown in FIGS. 9 and 10 , the support members 200 preferably include vertical plate portions 271 having upper edges 216 , 232 of the lowered central and raised outer lateral portions 210 , 230 with mounting pads 270 extending generally normal to the vertical plate portions 271 and parallel to the direction of travel 13 of the conveyor belt 6 . The mounting pads 270 each extend longitudinally along a longitudinal axis 273 and have a fastener receiving slot 272 formed by spaced lugs 272 a on either side thereof with both the pads 270 and slots 272 extending parallel to the direction of travel of the conveyor belt 13 . The lugs 272 a and slots 272 formed thereby are configured to extend from the upstream ends 138 of the mounting pads 270 and receive a bolt 312 therein.
In addition, the mounting pads 270 are spaced from each other to receive the depending legs 364 of the backing plates 360 therebetween. As shown in FIG. 11 , the depending legs 364 of the backing plate 360 preferably include notches 366 therein configured to guide the impact bars 300 onto the mounting pads 270 . Further, the notches or cut-outs 366 are configured to extend beyond the adjacent upper surfaces 216 , 232 of the support members 200 .
The impact bars 300 are further configured so as to minimize wear and damage to the conveyor belt 6 as the belt 6 travels thereacross in the operable orientation 8 . Preferably the impact bars 300 include a relatively thin, wear resistant plastic covering 304 atop the elastomeric body 302 and configured to be engaged by the conveyor belt 6 . Further, the plastic covering 304 includes a tapered upstream end 306 configured to urge the conveyor belt 6 upward as the conveyor belt 6 travels thereacross.
Further, the impact bars 300 are configured to ease translation of the subassemblies 20 , 22 toward a position under the belt 6 . As shown in FIGS. 2 and 9 , the impact bars 300 are mounted at an angle relative to the upper surface 111 of the cross member 100 to urge the conveyor belt 6 upwardly upon translation of the subassemblies 20 , 22 toward the center 112 of the cross members 100 . In particular, the upper surfaces 232 of the support members 200 are configured to define an angle A. Additionally, upper edge surfaces 216 of the lower central portions 210 are configured to mount the impact bars 300 thereon at an angle B less than the angle A defined by the raised upper portion 230 , e.g. such as 3 degrees off the upper surfaces 111 of the cross members 100 .
In another aspect of the invention, a dynamic impact bed assembly 400 is provided to transfer impact loading applied to the conveyor belt 6 to the stringer members 4 . The dynamic impact bed assembly 400 includes a dynamic frame assembly 401 which has structural components configured to extend below the belt 6 and be resiliently mounted on either side of the belt 6 to the conveyor frame stringer members 4 . The dynamic frame assembly 401 is resiliently mounted to the conveyor frame stringer members 4 so that the entire dynamic frame assembly 401 shifts as a single unit as impact forces are applied to the conveyor belt 6 thereabove.
Accordingly, the dynamic frame assembly 401 herein forms an integrated bed. As illustrated in FIGS. 14A-14C and 15 , the dynamic frame assembly 401 preferably includes longitudinal members 402 extending parallel to the direction of travel 13 of the conveyor belt 6 and cross stabilization beams 404 rigidly connected to the ends 450 of the longitudinal members 402 extending below and transverse to the direction of travel 13 of the conveyor belt 6 . The longitudinal members 402 preferably each include a tab mount 458 at each end 450 thereof to which the stabilization beams 404 are secured.
As shown in FIGS. 14A-14C , the dynamic frame assembly 401 further includes cross members 100 and support members 200 rigidly connected together to form a rigid support grid for the impact bars 300 , which are preferably substantially of the same construction as the corresponding components of the static bed assemblies 2 so as to be interchangeable therewith. The cross members 100 are configured to be mounted on the lower flange 452 of the longitudinal members 402 , with the ends 150 , 152 of the cross members 100 positioned adjacent the web 454 of the longitudinal members 402 and below upper flange 456 of the longitudinal members.
The dynamic frame assembly 401 further includes outboard mounting plates 413 of the longitudinal members 402 configured to extend transversely outward from the longitudinal members 402 and above the conveyor frame stringers 4 . The outboard mounting plates 413 are connected to a resilient mount assembly 408 , which is further connected onto the conveyor frame stringers 4 . As a result, as shown in FIGS. 14A-14C , the resilient mount assemblies 408 are positioned above the conveyor frame stringers 4 at a height that is generally aligned with the cross members 100 .
The resilient mount assemblies 408 , as shown, preferably include offset upper torsion bias units 420 and lower torsion bias units 430 interconnected by diagonal torsion links 409 . The resilient mount assemblies 408 are configured such that, upon the application of an impact force to the dynamic frame assembly 401 , the upper torsion bias units 420 , which are connected to and under the outboard mounting plate 413 of the longitudinal member 402 , are urged downward toward but offset from the lower torsion bias units 430 . As a result, the entire dynamic frame assembly 401 travels downward between the conveyor frame stringers 4 and thereby absorbs impact forces applied to the conveyor belt 6 .
The torsion bias units 430 are preferably standard Rosta units that include an outer housing 432 in which rubber or resilient material 434 is provided at the corners for urging a central bar connected to the link members 409 back to the rest position when the bar is turned in the housing 432 due to impact forces applied to the dynamic frame assembly 400 .
The bottoms of cross members 100 can travel from just below the upper surface 5 of the conveyor frame stringers 4 in the absence of impact loading to a maximum travel distance when high impact loads are received that is at approximately the center of the vertical height of the stringer members 4 , as shown in FIG. 14C . Preferably, the maximum travel distance of the dynamic bed assembly 400 is at least approximately 0.875 inches. In cooperation with the impact bars 300 , the elastomeric bodies of which provide approximately 0.625 inches of compression travel distance, the conveyor belt 6 is allowed a travel distance of at least 1.5 inches.
In a further preferred embodiment, the maximum deceleration distance travel is about 2.5 inches. While a larger deceleration distance is possible, the benefits of the increased deceleration distance are marginal after 2.5 inches. In addition, the increased distance contributes to stretching of the belt 6 , thereby increasing the likelihood of damage. Additionally, given the space constraints created by the stringer members 4 , and the belt 6 , in particular the return section of the belt 6 , and any other rigid obstructions a maximum distance of 2.5 inches is preferred.
To ensure a proper trough configuration, the dynamic bed assembly 400 includes rigid lateral support assemblies 410 mounted along each side of the belt 6 on the conveyor frame structure 4 . The rigid lateral support assemblies 410 include at least impact bar 300 mounted thereon and cooperate with the dynamic frame assembly 401 to define the trough configuration with the impact bars 300 mounted on the dynamic frame assembly 401 .
Preferably, the dynamic impact bed 400 includes a plurality of resilient mount assemblies 408 along each longitudinal member 402 . As illustrated, the number of resilient mounts 408 connected to each longitudinal member 402 is less than the number of ends 150 , 152 of the cross members 100 mounted to the longitudinal member 402 . Preferably, the resilient mounts 408 are positioned between the ends 150 , 152 of adjacent cross members 100 .
While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.
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Impact bed assemblies are provided, both static and dynamic, for absorbing impact forces taken by conveyor belts. The static and dynamic bed assemblies generally are constructed to optimize their impact absorption capacities while minimizing their space requirements under the belt.
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This invention relates to an oscillatory electro-hydraulic system for a material handling bucket, such as the arrangement utilized in connection with a tractor having a loader or material handling bucket which is pivotally controlled by means of hydraulic cylinders.
BACKGROUND OF THE INVENTION
The prior art is already aware of various arrangements of hydraulically-controlled pivotal buckets supported on a tractor or the like. These prior art arrangements commonly have hydraulic pumps and valves and cylinder assemblies, all for pivotally controlling and positioning the bucket, for the purpose of digging and loading and dumping the bucket. One example of such prior art is seen in U.S. Pat. No. 3,084,817 where an oscillatory digger is disclosed, and the present invention also relates to an oscillatory type of arrangement for the material handling bucket.
Accordingly, it is an object of this invention to provide an oscillatory electro-hydraulic system for a material handling bucket wherein the bucket can be completely and accurately controlled by means of the hydraulic power applied through cylinder assemblies connected with the bucket. Further, the present invention incorporates an electric system wherein the two cylinder assemblies employed in pivoting the bucket are pressurized according to the extension and contraction of the assemblies which control the electric system in the extending and contracting action itself. In this arrangement, the present invention employs two cylinder assemblies which are pressurized by means of a hydraulic pump and which have a valve interposed between the assemblies for selective directing of fluid pressure between the two cylinder assemblies, and the arrangement is such that only one of the two assemblies can be actuated for pivoting the bucket, while the other of the two assemblies can simply be free to extend or contract in response to the pressurizing and actuation of the first cylinder assembly.
That is, the present invention provides an oscillatory electro-hydraulic system wherein two cylinder assemblies are available but only one of the two can be utilized, in one mode of operation, and the two assemblies can be operative, in another mode of operation, when it is desired that the oscillatory action be effected in the control of the material handling bucket. In accomplishing this, the electric system is incorporated in the overall arrangement and is responsive to the extension and contraction of the cylinder assemblies, and the electric system is electrically connected with a hydraulic valve to thereby control the flow to one of the two cylinder assemblies, when it is desired that the additional one of the two assemblies be pressurized for pivoting of the bucket. Further, it will be seen and understood that the entire arrangement of the electro-hydraulic system disclosed herein can be applied to the conventional loader bucket, back-hoe, and like arrangements where the member holding the material is pivotally mounted and under the influence of hydraulic cylinders, as employed herein.
Another object of this invention is to provide an oscillatory electro-hydraulic system which incorporates the aforementioned alternative actions of pressurizing only one of two cylinder assemblies or of pressurizing both of the cylinder assemblies, with the latter action being utilized in the oscillatory mode of operation of the entire system. Further, in accomplishing this particular objective, the oscillatory mode is automatically repeated, and it is shown herein to be controlled by an electric system wherein the operator need only push an electric stop button in order to deactivate the oscillatory mode of this invention. Still further, the energizing or de-energizing of the oscillatory mode can be accomplished at any point in the cycle of the operation of the cylinder assemblies.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a conventional arrangement of a tractor with a loader bucket and a back-hoe supported thereon.
FIG. 2 is a side elevational view of the front fragment of a tractor and a loader bucket with the construction of this invention incorporated therein.
FIG. 3 is a schematic view of the hydraulic system of this invention, with the electric switches shown related thereto.
FIG. 4 is a schematic view of the electric system incorporated in this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a conventional arrangement of a tractor 10 mobile on the ground designated G and supporting a loader bucket 11 and a back-hoe bucket 12, all in a conventional arrangement. The laoder bucket 11 is supported on arms extending along opposite sides of the front portion of the tractor 10, such as the shown arm 13 which is pivoted on the tractor at the point designated 14. The bucket 11 is pivoted on the forward end of the arm 13 at the point designated 16, and thus the bucket can pivot fore-and-aft relative to the tractor 10, all in a conventional manner. A hydraulic cylinder assembly 17 is attached at its rod end to the arm 13 at the point designated 18 and an arm 19 is pivoted on the main arm 13 at a point designated 21, and the cylinder 17 is also pivoted on the arm 18 at a point designated 22. Finally, a link 23 has its opposite ends pivotally connected to the bucket 11 and the arm 19 such that extension and contraction of the cylinder assembly 17 will cause the arm 19 to pivot about the point 21 and thereby move the link 23 and thus pivot the bucket 11, all in a conventional arrangement. Another cylinder assembly 24 is mounted on the tractor 10 and connects with the main arm 13, for pivoting the arm 13 up and down, in the usual arrangement.
It will also be understood by one skilled in the art that the backhoe bucket 12 is pivotal on a support arm 26, such as pivoting about a point designated 27, and the bucket 12 is controlled by the cylinder assembly 28 in the pivot action. Accordingly, in the conventional arrangement, hydraulic cylinder assemblies are utilized for pivoting the bucket members, such as the members 11 and 12.
FIG. 2 shows the arrangement of a tractor designated 29 and having a main arm 31 under the influence of a cylinder assembly 32, and a material handling bucket 33 is pivoted about a point 34 on the forward end of the main arm 31, all as mentioned in connection with FIG. 1. Also, there is a cylinder assembly 36 and an arm 37 and a link 38, all pivotally connected together in the manner shown in FIG. 2, and thus extension and retraction of the assembly 36 will cause the arm 37 to pivot about its mounting point 39 and thereby displace the link 38 to pivot the bucket 33 about its mounting point 34, and this action can be used for loading or leveling or dumping the bucket 33, in the usual arrangement, such as that disclosed in connection with FIG. 1.
Additionally, FIG. 2 shows a cylinder assembly 41 which is pivotally connected to the arm 31 at the point designated 42 and which is pivotally connected to the bucket 33 at the point designated 43. Thus, extension and contraction of the assembly 41 will also cause pivotal movement of the bucket 33 about its pivot point 34, and the utilization of the two cylinder assemblies 36 and 41 will be more fully described in connection with FIG. 3. Therefore, as the construction is shown in FIG. 2, when the assembly 41 is extended, then the link 38 and arm 37 are moved, and that causes assembly 36 to retrack.
FIG. 3 shows the inventive arrangement of the hydraulic system which incorporates the two hydraulic cylinder assemblies 36 and 41 each of which includes a cylinder 44 and a piston rod 46 with the usual piston, all in a conventional assembly arrangement. Thus the assemblies have cylinder head ends and rod ends, and it is seen that both assemblies have their respective ends connected with hydraulic lines designated 47 and 48 and 49 and 51.
The hydraulic system also incorporates a hydraulic pump 49, suitably connected to and driven by a motor or prime mover 51, and having a hydraulic connection to a tank or fluid supply designated 52. Further, the other schematically-shown portions of the fluid supply or tank 52 are conventionally indicated on the drawing in the several locations shown. Thus a hydraulic line 53 extends from the pump 49 and to a four-way hydraulic valve 54 which is shown to be of a spool type and is shiftable through a control handle 56 operated by the operator. In the position shown in FIG. 3, of course there is no flow of hydraulic fluid from the pump 49 and through the valve 54, since the valve 54 is in a neutral position which simply has the oil or hydraulic fluid pumped back to the supply or tank through the line designated 57.
Shifting the control valve 54 to the right, as viewed in FIG. 3, hydraulically communicates the line 53 with the valve passageway 58 which in turn passes the fluid to the outlet line 59. Also, the valve passageway 61 is aligned with the line 57, for return to the tank for any oil coming from a line 62 with which the passageway 61 is aligned. Hydraulic pressure and flow in the line 59 passes to a line 63 which flow communicates with a pressure reducing valve 64 which is a normally open valve, as shown by its fluid passageway 66. Also, a line 67 communicates the valve 64 with the line 47 leading to the head end of the assembly 41. In that setting or mode, the assembly 41 is hydraulically pressured to extend the assembly, and this could cause the dumping of the bucket 33. Of course it will also be seen and understood that the fluid pressure in the rod end of the assembly 41 will move into the line 48 which is designated 62 at the valve 54, and thus the rod end of the assembly 41 is directed back to the tank 52.
When the assembly 41 is fully extended, due to the pressure in the head end thereof as described, the pressure in the line 67 increases until it exceeds the setting of the pressure in the reducing valve 64, and it will be seen and understood that the valve 64 can be selectively set for the pressure, by means of the selective adjustment characteristically shown by the arrow designated 68. This increased hydraulic pressure will be sensed by a pilot line 69 in the valve 64 and will thus shift the closure of the valve 64 to a position which closes the valve 64, and thus the valve 64 has shifted against the conventional spring 71 abutting the valve closure 72. With valve 64 closed, the pressure from the pump 49 is limited by a conventional type of pressure relief valve 73 which is connected to the line 53 by a line 74. Again the valve 73 is of an adjustable pressure type but is normally closed, though it has a pilot line 76 which causes the valve closure to shift to the open position when the pressure is of a sufficient magnitude to warrant opening of the valve 73 and relief of the pressure in the entire system. Thus the valve 73 is one of several pressure control or actuated valves shown in FIG. 3, and it is the one having the highest magnitude for pressure actuation or relief, and the valve 64 is the one of the several valves which has the lowest magnitude for pressure actuation, as will be more clearly seen hereinafter.
With the valve 64 closed, as described, the output from the pump 49 still being directed to the line 59 will be directed to the line 77 which leads to a pressure relief valve 78 having a closure 79 in the normally closed position, as established by the selective control and spring designated 81. The set actuating pressure for the valve 78 is a quantity somewhat less than that of the valve 73, and thus the valve 78, through its pilot line 82, will shift to an opening position under the influence of the hydraulic pressure which will then pass through the valve 78 and to a line 83 and into a control valve 84. Lines 49 and 51 are connected with the three-way control valve 84 which is normally open, and the valve has a hydraulic return passageway 86 in flow communication with the line 51 and with a line 87 leading to the tank or fluid supply designated 52. Thus the hydraulic fluid in the head end of the assembly 36 will simply return to the tank, and thus the assembly 36 can freely contract when the assembly 41 is extending, and thus the assembly 36 does not interfere with the dumping actuation of the cylinder assembly 41. Also, with the valve 84 in the position shown in FIG. 3, the pressure in the line 83 flow communicates with the valve passageway 88 which in turn communicates with the line 49 to direct the fluid pressure to the rod end of the assembly 36, and thus the assembly 36 is held in the contracted position, as desired for the dumping action.
At this time it should therefore be seen and noticed that the assemblies 36 and 41 are oppositely connected in that when the head end of the assembly 41 is pressurized then the rod end of the assembly 36 may be pressurized, and vice versa.
Next, for reversing the action described, shifting the four-way control valve 54 to the left, as viewed in FIG. 3, will fluid-flow communicate the valve passageway 89 with the pump line 53 and the line 62 and line end 48 to pressurize the rod end of the assembly 41. Of course the valve 54 is also then set in a position to have the line 59 directed to the line 57 and back to the tank or supply designated 52, as indicated. Such return flow in the line 59 is coming partly from the assembly 36 and through the line 49 and line 83 and through the check valve 91 in the line 92 which returns the fluid to the line 77 and then to the line 59. Also, fluid pressure in the head end of the assembly 41 is presented to the line 47 and line 67, and that pressure can be relieved through a small relief line 94 which flow communicates with the pilot line 69 in the reducing valve 64 to thereby permit the valve 64 to shift to its normally open position shown in FIG. 3. Thus the pressure at the head of the assembly 41 can return to the tank 52. During this operation, the assembly 36 can extend, since its rod end is no longer under fluid pressure, as explained, and thus again the extension and contraction of the assemblies 36 and 41 is in the opposite directions.
A pressure relief valve 96 is connected with the line 47, and the pressure magnitude of this valve is less than that of the valve 78, and, with valve 64 closed, fluid can go to the tank through valve 96 when the head end of assembly 41 is pressurized by the extension of assembly 36. The relative valve pressures are such that with the valve 73 having a pressure of a certain set magnitude, then the valve 78 may be provided with a pressure of 100 psi less than that magnitude, and the valve 96 may be provided with a pressure of 200 psi less than that magnitude, and the reducing valve 64 may be provided with a pressure of 400 psi less than that magnitude.
In this arrangement as described and shown in FIGS. 2 and 3, it will now be seen and understood that the cylinder assembly 41 can be pressurized at either end thereof, for either action of extension or contraction of the assembly 41, and the assembly 36 will permit and accommodate that action, but the assembly 36 will not be hydraulically pressurized until the full action of assembly 41 is accomplished. Also, it will be noticed that only a single line 77 extends between the assemblies 36 and 41, but the two lines 49 and 51 extend to the respective ends of the assembly 36. It will also be noticed that the three-way and normally open valve 84 is of a spool type under the influence of a compression spring 97, and the valve has passageways 98 and 99 and a solenoid unit designated 101. Energizing the unit 101 will cause the valve closure 84 to shift to where the passageway 98 flow communicates between the lines 49 and 87, and the hydraulic return passageway 99 flow communicates between the lines 83 and 51, with the return to the tank 52.
Further, FIGS. 2 and 3 show conventional electric limit switches 102 and 103, with those switches shown in FIG. 2 to be mounted on the arm 31 and adjacent an extension 104 on the lever 37, such that extension and contraction of the assembly 36 will cause the projection 104 to alternately engage the electric switches 102 and 103 for actuation of the switches as hereinafter described in connection with FIG. 4, and as indicated in FIG. 3 with the rod of the assembly 36 shown to be operatively related to the two switches for actuating the switches in the usual manner of actuating limit switches.
The aforementioned describes how the entire system is arranged such that only the cylinder assembly 41 is actually effective in the pivotal movement of the bucket 33, and the cylinder assembly 36 only permits and accommodates that action. The following describes the arrangement whereby both cylinder assemblies 41 and 36 can be powered for the purpose of oscillatory action on the bucket 36, such as desirable for digging and dumping or the like pivotal movement of the bucket 33.
FIG. 4 shows the electric system which has the live electric lines 106 and 107 and a conventional electric start button 108 is connected with the lines 106 and 107 through the line 109. A control relay 111 is also connected in the line 109 and is of a conventional arrangement having the first set of electric contacts designated 112 and the second set of electric contacts designated 113. The arrangement is such that upon pushing the start button for switch 108, the control relay 111 is electrically energized and thus its contacts 112 and 113 are closed.
FIG. 4 further shows a second control relay 114 in a line 116, and the relay 114 has two sets of electric contacts 117 and 118 which are schematically shown and are arranged in a conventional manner. Also, the limit switch 102 is shown connected with the line 116, and the switch is a normally open type of limit switch, and the limit switch 103 is also shown in the line 116 and it is a normally closed type of limit switch. With the arrangement shown and the energizing of the control relay 111, the current can pass through the limit switch 102 and that energizes the control relay 114 which closes the contacts 117 and 118. Further, the drawing shows the solenoid 101 connected with the relay 114, and the energizing of the relay 114 thus energizes the solenoid 101, and that shifts the closure or spool 84 shown in FIG. 3, to thus align the passageways 98 and 99 with the respective hydraulic lines connected with that control valve 84.
With the valve 84 shifted downwardly by energizing the solenoid 101, as described, hydraulic pressure in line 83 is directed to line 51 for pressurizing the head end of the cylinder assembly 36, while the return from the rod end of the assembly 36 can go through the valve passageway 98 and to the tank 52. As previously described, extending one of the cylinder assemblies causes the other to contract, and thus extending the cylinder assembly 36 causes the cylinder assembly 41 to contract, and the extension of cylinder assembly 36 also opens the limit switch 102 while control relay 114 remains closed since contacts 117 are closed and switch 103 is closed. Valve 64 is also closed, as described and at that time, and thus the pressure in line 47 will increase until the setting of the relief valve 96 is overcome by the pressure being exposed to the pilot line 119 of valve 96. Opening the valve 96 thus allows the hydraulic pressure in the head end of cylinder assembly 41 to be exhausted to the tank for return supply.
Next, continued extension of the cylinder assembly 36 causes the opening of the contacts in the limit switch 103 and therefore the current flowing to the control relay 114 is interrupted and thus the contacts 117 and 118 are opened and this results in the de-energizing of the solenoid 101. With the solenoid 101 de-energized, the valve spring 97 will of course shift the spool of the valve 84 and return it to the position shown in FIG. 3, and thus the cylinder assembly 36 will be caused to retract, while the cylinder assembly 41 will be caused to extend, and that reduces the hydraulic pressure in the line 67 and thus opens the valve 64 so that hydraulic pressure can pass through the valve 64 and into the head end of the cylinder assembly 41. Of course the valve 96 has again closed, when the pressure has sufficiently dropped in the valve 96 such as by the pressure relief action described with regard to valve 96, and therefore the cylinder assembly 41 can fully extend while the cylinder assembly 36 can fully retract and thereby have the limit switch 102 close to again re-energize the solenoid 101 to repeat the cycle, all in the automatic manner described.
The electric system also contains a switch 121 which is in the form of a stop button which the operator can activate to disconnect the entire electric system from the arrangement of the overall system shown and described. Of course with the inactivation of the electric system by the stop button 121, the solenoid 101 is de-energized and the cylinder assembly 36 is retracted and thus the cylinder assembly 41 will extend. Further, the described start and stop operations through the electric system can be accomplished at any point in the cycle described, regardless of the position of either of the cylinder assemblies 36 and 41. Also, when the stop button is actuated, the normal operation of cylinder assembly 41 can be performed while the utilization of the overall system with the operation of the cylinder assembly 36 will not be required nor made.
Further, the setting of the pressure on all of the pressure-activated valves disclosed is possible and is utilized in the operation and sequence of the systems, and also the location of the limit switches 102 and 103 will determine the cycle time and effectiveness of the entire system.
In summary, the system is arranged so that the bucket-actuating activity of the cylinder assembly 41 can be utilized alone, or both cylinder assemblies 36 and 41 can be utilized, through the use of the electric system described, and thus the oscillatory action on the bucket 33 is possible and that action is automatically accomplished.
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An oscillatory electro-hydraulic system for a material handling bucket and including two hydraulic cylinder assemblies connectable with the bucket for tipping the bucket, and including a hydraulic pump and control valve and pressure relief valve and a reducing valve, all for directing flow to the respective cylinder assemblies. An electric system is interconnected with the assemblies and with one of the control valves, for controlling the flow of fluid to one of the two cylinder assemblies.
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This application is a continuation-in-part of application Ser. No. 694,040, filed June 8, 1976, now abandoned.
BACKGROUND OF THE INVENTION
It is known in the art of railroad track shifting machines, such as track lifting and/or tamping machines, to provide on a rigid frame, an adjustable shift stop which provides a rail engaging surface against which the track "bottoms" during shifting operations, such as a lifting and/or tamping operation, so as to prevent further lifting of the track. After a rail engages the stop, however, the continuation of the jacking or tamping can cause damage to the rail between the stop and the point of shift.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a track shifting device comprising a rigid load supporting frame, track shifting means mounted on said frame, a stop device on said frame limiting the shifting of said track, and a pressure sensing means positioned adjacent said stop device for being engaged by the track when said shifted track is engaged with said stop device to sense a shifting force exerted on the rail after contact with said stop device and having a magnitude greater than a predetermined value and to generate a signal only after the rail has been brought into firm contact with the stop device, said pressure sensing means being connected to said track shifting means for controlling the shifting force, whereby the rail is always shifted to a predetermined shifted position in which it is in firm contact with said stop device.
Preferably the track shifting device is a track lifting and tamping machine and the track shifting means is a track lifting device and tamping means which achieves the lifting by acting directly on the rail while tamping ballast under the ties and rail to raise the track.
DESCRIPTION OF THE DRAWINGS
The following is a description, by way of example only, of two embodiments of the invention, reference being made to the accompanying drawings in which:
FIG. 1 is a diagrammatic representation of a track lifting device utilizing the stop device and the sensing means;
FIG. 2 is an enlarged view of the stop device and sensing means and
FIG. 3 shows a second embodiment of the track lifting device which also utilizes a stop and sensing means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is of embodiments in which the shifting of the track is lifting only. It will be appreciated, however, that the invention is applicable to machines for shifting the track in other directions e.g. laterally, and it is not intended that the invention be limited to machines carrying out lifting.
Referring now to the drawings, wherein it will be understood that the following explanation is limited to one side of the machine only and that the other side may be exactly symmetrical, a lift beam 10, mounted on wheels 11 so that it can be pushed along the track by machine 12, carries track lifting means in the form of a track lifting jack 13 of known configuration and/or a track tamping device (not shown) also of known type. A stop device shown generally at 15, which is height adjustable, is provided in the vicinity of the tamping heads in known fashion. It is to be understood that the lift beam 10 could be the frame of a track working machine, and particularly a tamping machine, the parts of which are conventional and hence are not shown.
The stop device 15 has a rail engaging head 23 which acts as a stop for the rail R. As clearly shown in FIG. 2, the stop device 15 is also provided with a ratchet 24 for adjusting the height of the rail engaging heads 23 relative to the lift beam 10. A sensing means in the form of a pressure sensitive (PS) transducer 26 is carried by the rail engaging heads 23, the transducer having electrical connections diagrammatically shown in FIG. 2 and a control valve V which controls application of hydraulic pressure fluid to the track lifting means, namely the jack 13 and/or the tamping device (not shown).
When shifting a railroad track and especially when lifting it to a predetermined position as established by the stop device 15, it is important that the rail be brought into firm contact with the stop device 15. This is because the exact predetermined position will not be reached until the firm contact is brought about. Mere touching of the rail to the stop device will not always insure that the rail is at the desired predetermined position. Moreover, particularly in the case of lifting the track to a desired level and then tamping ballast under it to maintain it at that level, it is important that the rail be seated firmly against the stop which is attached to the frame so that the weight of the frame opposes further lifting of the rail while further tamping is carried out. In addition, it is very important to avoid excess force on the rail, which tends to bend the rail between the stop device and the point of application of the force.
Thus, when the track lifting jack 13 and/or the tamping heads commence the squeeze operation in order to vertically lift the rails R of the track into the desired position, the rail R first touches the pressure sensitive transducer 26 and then exerts a force thereon. When firm contact has been established as determined by a predetermined pressure acting on the transducer, this causes the transducer to generate a signal to operate the valve V to immediately terminate or control the lifting and/or the tamping operation which has resulted in the force tending to lift the track. Where further tamping is to be carried out, only the lifting force will be terminated and the tamping force continued at least for a while. If desired, a reversal of the lifting force on the rail may be initiated. Thus, as the rail comes into firm contact with the stop at a predetermined fixed position, not only does the stop physically prevent further lifting of the rail but it may also immediately terminate any further tendencey to lift the rail.
The stop device 15 may be raised or lowered on the frame 10 by means of the ratchet 24 and this permits the height of the rail engaging heads 23 on each side of the machine to be individually adjusted relative to the frame 10 so as to allow for the track being in a super-elevated condition. Due to the geometric condition which exists in super-elevated curves, particularly in transition curves, a gradual adjustment may be required to compensate for changes in the track geometry. To this end, the individually adjustable rail engaging heads 23 can be manually adjusted by operator control or they may be adjusted by a preprogrammed apparatus such as a drive cam which thereby makes the necessary compensation.
A second form of the invention is shown in FIG. 3 wherein outwardly extending arms 18 are pivotally connected to shaft 14. The arms 18 are held in their desired position by known apparatus (not shown) and this aspect of the operation of the outwardly extending arms forms no part of the present invention. The outwardly extending arms 18 carry the rail engaging heads 23 and the shaft 14 is rigidly connected to the frame 10. Located on the frame 10 is the stop device 15 which comprises the stops 16 and the limiters 25, the stops and the limiters being adapted for contact therebetween. The sensing means is in the form of transducer 26 which is carried by the limiters 26. Limiters 25 are rigidly connected to the outwardly extending arms 18 and are adjustable such that the individual rails may be vertically lifted to various desired end positions according to the adjustment made to the limiters 25. Individual adjustment of each of the limiters is possible, as in the first embodiment described, so that compensation may be made for the individual rails when they are required to be in a super-elevated condition.
When the rail has reached a position where limiter 25 has firmly contacted stop 16, the transducer 26 on the limiter 25 transmits the appropriate signal to immediately terminate or control the lifting and/or tamping operation which has resulted in the force tending to lift the rail. If desired, a reversal of the lifting force on the rail may be initiated. Thus, as the rail causes the limiter to come into firm contact with the stop, not only does the stop physically prevent further lifting of the rail but it may also immediately terminate any further tendency to lift the rail.
Further embodiments of the invention but still within its scope are possible. The ratchet 24 used for vertical adjustment of the rail engaging heads 23 may be replaced with any apparatus allowing vertical adjustment of the rail engaging heads, such as a cam, a screw device, or another appropriate mechanism. So, similarly, may the limiters 25 be replaced by an appropriate mechanism. While the pressure sensitive transducer 26 is shown as being mounted on the rail engaging heads 23 or the limiters 25, it may be mounted elsewhere as long as the appropriate signal is sent to the lifting jack to terminate or control the lifting operation when rail contact is made. The transducer 26 may comprise any one of a number of suitable devices which would include pressure sensitive cells, a spool of a spool operation valve means or a proximity indicator which would indicate the position of the track. Accordingly, the invention should be construed only by reference to the accompanying claims.
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The invention provides for a stop device positioned on a railroad track shifting machine such as a track lifting and/or tamping machine and a sensor for generating a control signal to terminate or control the shifting action of the machine when the shifting force on the rail exceeds a predetermined value.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/280,268 filed Jan. 19, 2016. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to a bearing and seal combination used for an electronic throttle body assembly to allow the electronic throttle body assembly to operate at high pressure without damaging the bearings.
BACKGROUND OF THE INVENTION
[0003] Throttle body assemblies are generally known, and are a type of valve assembly used for controlling the amount of air flow into the engine during vehicle operation. The throttle body assemblies typically include a valve plate mounted on a shaft which is rotated to control air flow. There is also some type of bushing or bearing which supports the shaft. The throttle body assembly is located in the engine compartment, and is exposed to a harsh environment. The bearings or bushing may be exposed to debris that may be in the air flowing through the valve assembly, acid from the vehicle fuel, and may be exposed to high pressure and high air flow rate. Requirements are such that throttle body assemblies are adaptable for gasoline and diesel applications, as well as have the capability to withstand exposure to a harsh environment. If bearings are used, the bearings are typically needle bearings, because needle bearings and bushings are able to withstand the pressure in the harsh environment.
[0004] Ball bearings are considered more desirable for use in these applications since ball bearings offer the advantages of greater durability, assembly, and reduced friction. However, ball bearings typically cannot withstand these harsh environments, primarily because ball bearings are not suitable for operation when exposed to higher air pressure and vacuum, such as environments where the pressure or vacuum is greater than 1.0 bar. The debris and the acid may cause degradation of the bushings or bearings.
[0005] Accordingly, there exists a need for a throttle body or valve assembly which is able to incorporate the use of ball bearings which are configured to withstand a harsh environment, such as those where the pressure is 1.0 bar or greater.
SUMMARY OF THE INVENTION
[0006] The present invention is a throttle body assembly which is adaptable for both gasoline and diesel applications, and may also be used for applications to meter fluid, such as for a water cooling valve. The throttle body assembly includes at least one bearing assembly and a seal which are used to configure the bearing assembly to withstand a high-pressure environment.
[0007] In accordance with an embodiment, the present invention is a valve assembly, including a housing, a central port formed as part of the housing, an aperture formed as part of the housing, and a shaft extending through the aperture such that the shaft extends through the central port. A valve plate is mounted on the shaft such that the valve plate is disposed in the central port. There is also a bore formed as part of the housing, the shaft at least partially extending through the bore. At least one seal is located in the bore such that the seal surrounds the shaft, and at least one bearing assembly is mounted on the shaft and located in the bore such that the bearing is adjacent the seal. As the shaft is rotated to change the position of the valve plate and air flow through the central port, the seal prevents the bearing from being damaged due to exposure to high pressure from the air flow. In one embodiment, the seal prevents the bearing from being damaged due to exposure to pressures greater than or equal to 1.0 bar.
[0008] In one embodiment, the seal is located between the bearing assembly and the central port. In another embodiment, the bearing assembly is located between the seal and the central port.
[0009] In one embodiment, the seal has an X-cross section which includes a least one inner flange portion and at least on outer flange portion, where the inner flange portion is in contact with the shaft, and the outer flange portion is in contact with the boss.
[0010] In another embodiment, the seal includes a base portion, and at least one flange portion integrally formed with the base portion, where the base portion is in contact with the bore, and the flange portion is in contact with the shaft.
[0011] In yet another embodiment, the seal includes an outer base portion, and at least one inner lip portion is integrally formed with the outer base portion, such that the outer base portion is in contact with the bore, and the inner lip portion is in contact with the shaft.
[0012] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0014] FIG. 1 is a perspective view of a housing of the throttle body assembly, according to embodiments of the present invention;
[0015] FIG. 2 is an exploded view of a throttle body assembly of an embodiment, according to embodiments of the present invention;
[0016] FIG. 3 is a sectional side view of a bearing assembly disposed in a bore of a housing, according to embodiments of the present invention;
[0017] FIG. 4 is a sectional side view of a bearing assembly and an embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention;
[0018] FIG. 5 is a sectional side view of a bearing assembly and another embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention;
[0019] FIG. 6 is a sectional side view of a bearing assembly and yet another embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention;
[0020] FIG. 7 is a sectional side view of a bearing assembly and still another embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention;
[0021] FIG. 8 is a sectional side view of a bearing assembly and still another embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention; and
[0022] FIG. 9 is a sectional side view of a bearing assembly and yet another embodiment of a seal disposed in a bore of a housing, according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0024] A throttle control assembly according to the present invention is shown in the Figures generally at 10 . The assembly 10 includes a housing 12 , and formed as part of the housing 12 is a central port 14 , through which air passes during operation of the assembly 10 . Extending through in the central port 14 is a shaft 16 , which is rotatable. The shaft 16 includes a slot 18 , and disposed in the slot 18 is a valve member, which in this embodiment is a valve plate 20 . The valve plate 20 includes two apertures 22 , which are in alignment with two threaded apertures 24 formed as part of the shaft 16 . Also connecting the plate 20 to the shaft 16 is a fastener, which in this embodiment is a threaded screw 26 , which is inserted through the apertures 22 of the plate 20 and the threaded apertures 24 of the shaft 16 , securing the valve plate 20 to the shaft 16 .
[0025] The shaft 16 is partially disposed in an aperture 28 a formed as part of a first boss 52 a, and the first boss 52 a is formed as part of the housing 12 . The central port 14 also includes a side wall 14 a, which also forms part of the first boss 52 a, and the aperture 28 a is formed as part of the boss 52 a. A first bearing assembly 30 a and a second bearing assembly 30 b support the shaft 16 , and allow for the shaft 16 to rotate relative to the housing 12 . The first bearing assembly 30 a is located in the boss 52 a and held in place in the boss 52 a by a plug 32 . The second bearing assembly 30 b is located in a second boss 52 b, and is maintained in the boss 52 b by a C-washer 34 located in a groove 50 formed as part of the shaft 16 . There is a second aperture 28 b formed as part of the side wall 14 a such that the second aperture 28 b is formed as part of the second boss 52 b. The second bearing assembly 30 b is located between the C-washer 34 and the end of the shaft 16 , and is located inside and supported by the boss 52 b formed as part of the housing 12 .
[0026] The housing 12 also includes a cavity, shown generally at 36 , and disposed in the cavity 36 is an actuator, which in this embodiment is an electric motor 38 , held in place by two motor screws 40 . Attached to the shaft of the motor 38 is a first gear, or pinion gear 42 . The pinion gear 42 is in mesh with a second gear, or intermediate gear 44 . The intermediate gear 44 is mounted on an intermediate shaft 46 , and the intermediate shaft 46 partially extends into an aperture 48 formed as part of the housing 12 . Also formed as part of the intermediate gear 44 is a middle gear 54 , which is smaller in diameter compared to the intermediate gear 44 . The middle gear 54 is in mesh with a sector gear 58 .
[0027] Mounted on and surrounding the outside of the boss 52 is a lower bushing 60 , and mounted on the lower bushing 60 is a biasable member 62 , which in this embodiment is a return spring 62 , having two coil portions. The return spring surrounds the lower bushing 60 , and there is an intermediate bushing 66 disposed between the coil portions of the return spring 62 . The intermediate bushing 66 includes a slit portion 68 which allows the intermediate bushing 66 to partially deflect without breaking, such that the coil portions may be made together from a single continuous wire, and the intermediate bushing 66 may be installed between the coil portions.
[0028] The sector gear 58 is mounted on one of the coil portions, and one end of the return spring 62 is in contact with a first pin 74 functioning as a first spring stop, and a second end of the return spring 62 in contact with a second pin 76 functioning as a second spring stop. Each of the pins 74 , 76 are partially disposed in corresponding apertures 78 formed as part of the housing 12 .
[0029] Connected to the housing 12 is a cover 80 , and disposed between the cover 80 and the housing 12 is a seal 82 which surrounds an outer lip 84 formed as part of the housing 12 . The cover 80 is connected to the housing 12 using a plurality of clips 86 . There is also a secondary cover 88 , which is attached to the cover 80 . Once the cover 80 is attached to the housing 12 , the terminals for the motor 38 can be viewed through an opening in the cover 80 . Once it is determined that the terminals of the motor 38 are in contact with the terminals formed as part of the cover 80 , the secondary cover 88 is attached to the cover 80 .
[0030] The cover 80 also includes a connector 90 which is in electrical communication with the motor 38 , such that the connector 90 is able to be connected to a source of power. Integrally formed with the cover 80 is a lead frame, which places the connector 90 in electrical communication with a sensor (not shown).
[0031] An enlarged sectional view of a portion of the housing 12 is shown in FIG. 3 , which includes the boss 52 b, and the second bearing assembly 30 b. Although the second bearing assembly 30 b is shown, it is within the scope of the invention that the various aspects of the invention apply to the first bearing assembly 30 a as well. The bearing assemblies 30 a , 30 b in this embodiment are ball bearing assemblies. The bearing assembly 30 b shown in FIG. 3 includes an inner race 92 in contact with the shaft 16 , and an outer race 94 in contact with the boss 52 b. Disposed between the inner race 92 and the outer race 94 is a bearing member 94 a, which in this embodiment is a ball. There are also several outer seal surfaces 96 , one of the outer seal surfaces 96 a may be part of the shaft 16 , another of the outer seal surfaces 96 b is part of the boss 52 b, one of the surfaces 96 c may be part of the inner race 92 , and another of the outer seal surfaces 96 d may be part of the outer race 94 . There are also several inner seal surfaces 98 . More specifically, there is an inner seal surface 98 a which is part of the shaft 16 , inner seal surfaces 98 b 1 , 98 b 2 which are part of the boss 52 b, another inner seal surface 98 c which is part of the inner race 92 , and an inner seal surface 98 d which is part of the outer race 94 .
[0032] There are different types of seals which may be used to provide a sealing function at or around the bearing assembly 30 b. An embodiment of a seal 100 used with the bearing assembly 30 b is shown in FIG. 4 , where the seal 100 is located between the bearing assembly 30 b and the sidewall 14 a, such that debris from the central port 14 is substantially prevented from contacting the bearing assembly 30 b. The seal 100 includes a base portion 100 a and two flange portions 100 b. The base portion 100 a is in contact with several of the inner seal surfaces 98 b 1 , 98 b 2 , 98 d, one of the flange portions 100 b is in contact with the inner seal surface 98 a formed as part of the shaft 16 and one of the inner seal surfaces 98 b 1 formed as part of the boss 52 b , and another of the flange portions 100 b is in contact with the inner seal surface 98 a formed as part of the shaft 16 and one of the inner seal surfaces 98 c formed as part of the inner race 92 .
[0033] Another embodiment of a seal 102 is shown in FIG. 5 , where this seal 102 is also located between the bearing assembly 30 b and the side wall 14 a. However, in this embodiment, the seal 102 includes an X cross-section, having inner flange portions 102 a and outer flange portions 102 b. One of the inner flange portions 102 a is in contact with the inner seal surface 98 a formed as part of the shaft 16 and one of the inner seal surfaces 98 c formed as part of the inner race 92 , and another of the inner flange portions 102 a is in contact with the inner seal surface 98 a formed as part of the shaft 16 and one of the inner seal surfaces 98 b 1 formed as part of the boss 52 b. One of the outer flange portions 102 b is in contact with the inner seal surfaces 98 b 1 , 98 b 2 of the boss 52 b, and another of the outer seal surfaces 102 b is in contact with one of the inner seal surfaces 98 b 2 of the boss 52 b and the inner seal surface 98 d of the outer race 94 .
[0034] The seal 102 may also be placed outside of the bearing assembly 30 b, as shown in FIG. 6 , such that the bearing assembly 30 b is closer to the side wall 14 a in relation to the seal 102 . In this embodiment, one of the inner flange portions 102 a of the seal 102 is in contact with the outer seal surface 96 a formed as part of the shaft 16 , the other inner flange portion 102 a is in contact with the outer seal surface 96 a of the shaft 16 , and the outer seal surface 96 c formed as part of the inner race 92 . One of the outer flange portions 102 b is in contact with the outer seal surface 96 b formed as part of the boss 52 b , the other outer flange portion 102 b is in contact with the outer seal surface 96 b formed as part of the boss 52 b, and the outer seal surface 96 d formed as part of the outer race 94 .
[0035] Another embodiment is shown in FIG. 7 , where the shaft 16 has two diameters, a first diameter 16 a, which is smaller than a second diameter 16 b. Also shown in FIG. 7 is the seal 102 having the X cross-section, where one of the inner flange portions 102 a is in contact with the inner seal surface 98 c of the inner race 92 and the inner seal surface 98 a of the shaft 16 , and another of the inner flange portions 102 a is in contact with two of the inner seal surfaces 98 a , 98 b 3 of the shaft 16 . Furthermore, one of the outer flange portions 102 b is in contact with the inner seal surface 98 b 2 of the boss 52 a, and the other outer flange portion 102 b is in contact with the inner seal surfaces 98 b 1 , 98 b 2 of the boss 52 a.
[0036] Yet another embodiment is shown in FIG. 8 , with the shaft 16 also having two diameters 16 a , 16 b. In this embodiment, a lip seal 104 is used having an outer base portion 104 a and an inner lip portion 104 b. In this embodiment, the outer base portion 104 a of the lip seal 104 is in contact with the inner seal surfaces 98 b 1 , 98 b 2 of the boss 52 . The inner lip portion 104 b is in contact with the inner seal surface 98 a of the shaft 16 , and the inner seal surface 98 c of the inner race 92 .
[0037] Another embodiment of the present invention is shown in FIG. 9 , with like numbers referring to like elements. In this embodiment, the shaft 16 again has two diameters 16 a , 16 b. However, in this embodiment, the seal 102 is located on the second diameter 16 b, which is the larger of the two diameters 16 a , 16 b. In this embodiment, the housing 12 and the boss 52 a are shaped differently to accommodate the change in location of the seal 102 . The inner race 92 is adjacent the portion of the shaft 16 having the second diameter 16 b, but is still mounted to the portion of the shaft 16 having the first diameter 16 a. The seal 102 having the X cross-section is used, but it is within the scope of the invention that seals of other shapes and cross-sections may be used as well. In this embodiment, one of the inner flange portions 102 a is in contact with the inner seal surface 98 a of the shaft 16 , and another of the inner flange portions 102 a is in contact with the inner seal surface 98 a of the shaft 16 and one of the inner seal surfaces 98 b 1 of the boss 52 a. Also, one of the outer flange portions 102 b is in contact with the inner seal surface 98 d of the outer race 94 and the inner seal surface 98 b 2 of the boss 52 a, and the other outer flange portion 102 b is in contact with the inner seal surfaces 98 b 1 , 98 b 2 of the boss 52 a
[0038] In operation, the spring 62 biases the sector gear 58 , and therefore the shaft 16 and valve plate 20 towards a closed position, such that the central port 14 is substantially closed, or blocked completely, depending upon how the assembly 10 is configured. When a current is applied to the motor 38 , the pinion gear 42 is rotated, which causes the rotation of the intermediate gear 44 , the middle gear 54 , and the sector gear 58 . To rotate the sector gear 58 , the force applied to the sector gear 58 by the return spring 62 is overcome. The amount of rotation of the sector gear 58 is in proportion to the amount of current applied to the motor 38 , which must overcome the force applied to the sector gear 58 by the return spring 62 .
[0039] As the sector gear 58 is rotated, the shaft 16 is rotated as well, rotating the plate 20 , and allowing increased levels of air flow through the central port 14 . The amount of rotation of the sector gear 58 is detected by the sensor, such that the valve plate 20 may be placed in a desired position. The shaft 16 is supported by the bearing assemblies 30 a , 30 b, and the seals 100 , 102 , 104 prevent leaking around the bearing assemblies 30 a , 30 b during the operation of the throttle control assembly 10 . The throttle control assembly 10 may be used to control the flow of air, or any type of fluid, making the assembly 10 useful for many different applications, including applications where the assembly is exposed to high pressures.
[0040] The description of the invention is merely exemplary in nature and, thus, 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.
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The present invention is a throttle body assembly which is adaptable for both gasoline and diesel applications, and may also be used for applications to meter fluid, such as for a water cooling valve. The throttle body assembly includes at least one bearing assembly and at least one seal which is used to configure the bearing assembly to withstand a high-pressure environment.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is entitled to the benefit of and incorporates by reference subject matter disclosed in International Patent Application No. PCT/EP2013/001167 filed on Apr. 19, 2013 and European Patent Application 12002802.2 filed Apr. 20, 2012.
FIELD OF THE INVENTION
The present invention relates to a fan of a vapour compression system comprising a compressor, a heat rejecting heat exchanger, an expansion device and an evaporator arranged in a refrigerant circuit. The fan being controlled by means of the method of the invention is arranged to provide a secondary fluid flow across the heat rejecting heat exchanger. The method of the invention allows the electrical energy consumption of the fan to be reduced as compared to prior art control methods.
BACKGROUND
Vapour compression systems, such as refrigeration systems, air condition systems or heat pumps, normally comprise a heat rejecting heat exchanger arranged to exchange heat with a secondary fluid flow across the heat rejecting heat exchanger in such a manner that heat is rejected from the vapour compression system and transferred to the secondary fluid flow. The heat rejecting heat exchanger may, e.g., be in the form of a condenser or in the form of a gas cooler.
Previously, an outlet temperature of refrigerant leaving the heat rejecting heat exchanger was expected to decrease slowly as a function of an increase in fan speed of the one or more fans arranged to cause the secondary fluid flow across the heat rejecting heat exchanger. Some vapour compression systems have been provided with heat recovery systems arranged to recover heat from the refrigerant immediately before the refrigerant reaches the heat rejecting heat exchanger, and use the recovered heat in other parts of the vapour compression system or in systems for external to the vapour compression system.
The heat recovery has the consequence that the refrigerant which reaches the heat rejecting heat exchanger has already been cooled, and thereby the heat needing to be rejected from the vapour compression system by the heat rejecting heat exchanger is considerably reduced. As a consequence, the heat rejecting heat exchanger may be over-dimensioned. The outlet temperature of refrigerant leaving the heat rejecting heat exchanger decreases drastically as the speed of the fan increases. This makes it difficult to control the fan or fans, because small variations in fan speed cause significant variations in the outlet temperature of refrigerant leaving the heat rejecting heat exchanger, thereby causing instability. Furthermore, at low fan speed, the response in outlet temperature to changes in the fan speed is very strong, while at high fan speed, the response in outlet temperature to changes in the fan speed is very weak. The optimal operating point for the fan speed is exactly at the point where the response in outlet temperature changes from strong to weak. This makes it even more difficult to control the fan speed dynamically. This problem has previously been solved by simply allowing the fan or fans to operate continuously at a high rotational speed, e.g. at or close to maximum rotational speed. However, this causes a relatively high electrical energy consumption of the fan or fans.
U.S. Pat. No. 5,086,626 discloses an air conditioner with function for temperature control of radiant heat exchanger. A fan delivers air to an indoor heat exchanger. A temperature sensor detects the temperature of the radiant heat exchanger. A controller controls the indoor heat exchanger fan speed for controlling the radiant heat temperature from the radiant heat exchanger in accordance with a temperature detection signal from the sensor. In U.S. Pat. No. 5,086,626 the fan speed is controlled on the basis of a measured surface temperature of the radiant heat exchanger, and not on the basis of a temperature of refrigerant leaving the radiant heat exchanger.
SUMMARY
It is an object of embodiments of the invention to provide a method for controlling a fan of a vapour compression system in which electrical energy consumption of the fan is decreased.
It is a further object of embodiments of the invention to provide a method for controlling a fan of a vapour compression system in which stability of operation of the vapour compression system is obtained without increasing the electrical energy consumption of the fan.
According to a first aspect the invention provides a method of controlling a fan of a vapour compression system, the vapour compression system comprising a compressor, a heat rejecting heat exchanger, an expansion device and an evaporator arranged in a refrigerant circuit, said fan being arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, the method comprising the steps of:
establishing a temperature, T 1 , of refrigerant leaving the heat rejecting heat exchanger, establishing a temperature, T 2 , of ambient air of the heat rejecting heat exchanger, deriving a temperature difference, ΔT=T 1 -T 2 , between the temperature (T 1 ) of refrigerant leaving the heat rejecting heat exchanger and the temperature (T 2 ) of ambient air of the heat rejecting heat exchanger, comparing the temperature difference, ΔT, to a first threshold value and to a second threshold value, the second threshold value being smaller than or equal to the first threshold value, and controlling the rotational speed of the fan on the basis of the comparing step.
Vapour compression system’ should be interpreted to mean any system in which a flow of fluid, such as refrigerant, circulates and is alternatingly compressed and expanded, thereby providing either refrigeration or heating of a volume. Thus, the vapour compression system may be a refrigeration system, an air condition system, a heat pump, etc. The vapour compression system, thus, comprises a compressor, a heat rejecting heat exchanger, at least one expansion device, e.g. in the form of expansion valve(s), and at least one evaporator, arranged along a refrigerant circuit.
The vapour compression system further comprises a fan arranged to provide a secondary fluid flow across the heat rejecting heat exchanger. The secondary fluid flow may be a flow of air, or a flow of another gas than air, driven by the fan. Thus, the heat rejecting heat exchanger provides heat exchange between refrigerant flowing through the heat rejecting heat exchanger, via the refrigerant circuit, and fluid of the secondary fluid flow. The heat exchange takes place in such a manner that heat is rejected from the refrigerant and transferred to the fluid of the secondary fluid flow.
It should be noted that the vapour compression system may comprise two or more fans arranged to provide the secondary fluid flow across the heat rejecting heat exchanger. Therefore, in the following the term ‘fan’ should be interpreted to cover a single fan providing the secondary fluid flow, one of two or more fans providing the secondary fluid flow, or two or more fans providing the secondary fluid flow.
According to the method of the first aspect of the invention, a first temperature, T 1 , is initially established, T 1 being a temperature of refrigerant leaving the heat rejecting heat exchanger. T 1 may be measured directly, e.g. by means of a temperature sensor which may be arranged in the refrigerant circuit at the outlet of the heat rejecting heat exchanger. As an alternative, T 1 may be established in a more indirect manner, e.g. by measuring another value which is indicative of the temperature of refrigerant leaving the heat rejecting heat exchanger, and subsequently calculating the temperature on the basis of the measured value.
Subsequently or simultaneously, a second temperature, T 2 , is established, T 2 being a temperature of ambient air of the heat rejecting heat exchanger. T 2 may be measured directly, e.g. by means of a temperature sensor arranged near the heat rejecting heat exchanger, possibly in the secondary fluid flow. As an alternative, T 2 may be established in a more indirect manner, e.g. by measuring another value which is indicative of the temperature of ambient air of the heat rejecting heat exchanger, and subsequently calculating the temperature on the basis of the measured value.
Subsequently, a temperature difference, ΔT=T 1 -T 2 , is derived, ΔT being the difference between the temperature (T 1 ) of refrigerant leaving the heat rejecting heat exchanger and the temperature (T 2 ) of ambient air of the heat rejecting heat exchanger. Accordingly, ΔT indicates how close the temperature of refrigerant leaving the heat rejecting heat exchanger is to the ambient temperature, since ΔT approaches zero when T 1 approaches T 2 . The temperature difference is a measure for how much heat it is required to reject by means of the heat rejecting heat exchanger in order to ensure that the vapour compression system is operated in an efficient manner. If the temperature difference is small, sufficient heat is being rejected by the heat rejecting heat exchanger, and the fan speed may be reduced. if the temperature difference is large, there is a need for more heat to be rejected by the heat rejecting heat exchanger, and it may be necessary to increase the fan speed for obtaining more heat being rejected by the heat rejecting heat exchanger.
It should be noted that the method of the present invention should also be interpreted to cover situations where the temperature difference is measured directly, e.g. by means of a thermocouple, instead of measuring the first and second temperatures separately and calculating the temperature difference.
Subsequently, the temperature difference, ΔT, is compared to a first threshold value and a second threshold value, the second threshold value being smaller than or equal to the first threshold value.
Finally, the rotational speed of the fan is controlled on the basis of the comparing step. Thus, the rotational speed of the fan is controlled on the basis of how close the temperature of refrigerant leaving the heat rejecting heat exchanger is to the temperature of the ambient air. By comparing the temperature difference, ΔT, to the first threshold value and the second threshold value, the rotational speed of the fan can be controlled in such a manner that the temperature difference is maintained within a desired range. The temperature difference can be regarded as a measure for how much heat is required to be rejected by the heat rejecting heat exchanger, and accordingly, the rotational speed of the fan is thereby controlled in such a manner that the speed required ensures sufficient heat is rejected for obtaining efficient operation of the vapour compression system, but without applying an excessive speed. Thereby the electrical energy consumption of the fan is reduced without risking instability.
The step of controlling the rotational speed of the fan may comprise the steps of:
if the temperature difference, ΔT, is larger than the first threshold value, increasing the rotational speed of the fan, and if the temperature difference, ΔT, is smaller than the second threshold value, decreasing the rotational speed of the fan.
According to this embodiment, the rotational speed of the fan is increased if the temperature difference is large, and the rotational speed of the fan is decreased if the temperature difference is small. As described above, a large temperature difference indicates that more heat needs to be rejected by the heat rejecting heat exchanger, which is obtained by increasing the rotational speed of the fan. A small temperature difference indicates that sufficient heat is being rejected by the heat rejecting heat exchanger, which allows reducing the rotational speed of the fan, thereby reducing the electrical energy consumption of the fan, without risking instability. Furthermore, the rotational speed of the fan is controlled in such a manner that the temperature difference is maintained within a desired range.
The step of decreasing the rotational speed of the fan may be performed by ramping down the rotational speed. According to this embodiment, the rotational speed of the fan is decreased slowly and gradually, e.g. continuously or in small steps, when the temperature difference is smaller than the second threshold value. Thereby it is prevented that the rotational speed of the fan is decreased so much that the temperature difference jumps to a value above the first threshold value.
The step of decreasing the rotational speed of the fan may include decreasing the speed by 0.1%-10.0% of the maximum rotational speed of the fan per minute, such as 0.1%-9.0%, such as 0.5%-8.0%, such as 1.0%-7.0%, such as 2.0%-6.0%, such as 3.0%-5.5%, such as 4.0%-5.0%, such as approximately 5.0%. According to this embodiment, the rotational speed of the fan is decreased in fixed steps, and the size of the fixed step is defined as a specified percentage of the maximum rotational speed which the fan is capable of operating at. For instance, if the maximum rotational speed of the fan is 300 rpm, and the rotational speed is decreased by 1% of the maximum rotational speed per minute, then the rotational speed of the fan is decreased by 3 rpm per minute.
Alternatively or additionally, the step of increasing the rotational speed of the fan may be performed by jumping up the rotational speed. According to this embodiment, the rotational speed of the fan is increased abruptly and in a large step when the temperature difference is larger than the first threshold value. Thereby it is ensured that when the temperature difference is too high, indicating that more heat needs to be rejected by the heat rejecting heat exchanger, the rotational speed is increased quickly and significantly, in order to quickly move the temperature difference into the desired range.
The step of increasing the rotational speed of the fan may include increasing the rotational speed of the fan by 5%-100% of the maximum rotational speed of the fan, such as 7%-90%, such as 10%-80%, such as 15%-75%, such as 20%-70%, such as 30%-65%, such as 40%-60%, such as 45%-55%, such as approximately 50%.
Preferably, when a jump in rotational speed has been performed, a specified time period is allowed to elapse before it is determined whether or not an additional jump in rotational speed is required. The vapour compression system is allowed to react to the first jump before performing another jump.
According to one embodiment, the rotational speed of the fan is ramped down when the temperature difference is smaller than the second threshold value, and the rotational speed is jumped up when the temperature difference is larger than the first threshold value. Asymmetry in the control of the rotational speed of the fan is particularly advantageous for the following reasons. When the temperature difference is high, indicating that the electrical energy consumption of the system is too high, and there is a risk of instability. Accordingly, it is desirable to move away from this situation as quickly as possible. When the temperature difference is low, indicating that the fan is probably operating at a rotational speed which is too high, thereby consuming too much electrical energy, it is desirable to reduce the rotational speed. However, the total electrical energy consumption of the vapour compression system when the temperature difference is too high is much higher than the total electrical energy consumption when the temperature difference is too low. Therefore it is desirable to increase the fan speed quickly when the temperature difference is high, even if this temporarily results in a rotational speed which is too high. However, when the temperature difference is too low, it is more important to avoid that the temperature difference increases to above the first threshold value than to decrease the rotational speed of the fan quickly. Therefore it is desirable to reduce the rotational speed slowly and in a controlled manner in this situation. Thus, according to this embodiment an optimal energy consumption is ensured without risking instability.
As an alternative, the step of increasing the rotational speed of the fan may be performed by ramping up the rotational speed. According to this embodiment, the rotational speed is increased and decreased in essentially the same manner. The step of increasing the rotational speed of the fan includes increasing the speed by 1%-50% of the maximum rotational speed of the fan per minute, such as 0.15%-9.045%, such as 0.57%-8.030%, such as 1.010%-7.025%, such as 2.010%-6.200%, such as 3.015%-5.25%, such as 4.020%-5.30%, such as approximately 5.025%.
The step of increasing the rotational speed of the fan and/or the step of decreasing the rotational speed of the fan may be performed using an asymmetric function, e.g. a scaling function, e.g. an aggressive scaling function, such as an exponential function. According to this embodiment it can also be ensured that temperature difference can be decreased quickly if it is established that the temperature difference is above the first threshold value.
The second threshold value may be smaller than the first threshold value, and the method may further comprise the step of:
if the temperature difference, ΔT, is smaller than the first threshold value and larger than the second threshold value, maintaining the rotational speed of the fan.
According to this embodiment, the rotational speed of the fan is controlled in such a manner that the temperature difference is maintained within the range defined by the first threshold value and the second threshold value.
As an alternative, the first threshold value is equal to the second threshold value. According to this embodiment, the rotational speed of the fan is controlled in order to obtain a specific temperature difference, i.e. a set point value of the temperature difference.
The vapour compression system may be operated with a refrigerant being in a supercritical state when flowing in the refrigerant circuit. According to this embodiment, the heat rejecting heat exchanger is a gas cooler.
The refrigerant flowing in the refrigerant circuit may be carbon-dioxide (CO 2 ). CO 2 is often in a supercritical state when used as a refrigerant, and the heat rejecting heat exchanger is a gas cooler.
According to a second aspect the invention provides a heat rejecting heat exchanger comprising a fan being arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, said fan being capable of being controlled by a method according to the first aspect of the invention.
The invention further provides a refrigeration system comprising a compressor, a gas cooler, an expansion device and an evaporator arranged in a refrigerant circuit, said gas cooler being a heat rejecting heat exchanger according to the second aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in further detail with reference to the accompanying drawings in which
FIGS. 1-3 are graphs illustrating temperature of refrigerant leaving the heat rejecting heat exchanger, as a function of rotational speed of a fan,
FIG. 4 is a graph illustrating control of rotational speed of a fan according to two different embodiments of the invention, and
FIGS. 5-7 show three block diagrams, each illustrating an integrating controller for use in a method for controlling rotational speed of a fan.
DETAILED DESCRIPTION
FIG. 1 is a graph illustrating temperature (outlet temperature) of refrigerant leaving a heat rejecting heat exchanger of a vapour compression system, said temperature being illustrated as a function of rotational speed of a fan arranged to provide a secondary fluid flow across the heat rejecting heat exchanger. FIG. 1 illustrates that at low fan speeds, the outlet temperature is relatively high, but the outlet temperature decreases rapidly when the fan speed is increased, the temperature thereby approaching the temperature of ambient air of the heat rejecting heat exchanger.
It is a disadvantage if the outlet temperature is very high, i.e. much higher than the temperature of the ambient air, because the heat rejecting heat exchanger is not operating efficiently, and thereby the total energy consumption of vapour compression system is increased, and there is a risk of instability. Therefore, in prior art methods for controlling the rotational speed of the fan, the fan has been operated continuously at a relatively high rotational speed, at or near region 1 , in order to avoid the outlet temperature increasing due to a too low fan speed. However, this causes a relatively high electrical energy consumption of the fan.
FIG. 2 shows the graph of FIG. 1 . However, in FIG. 2 , an optimal operating point 2 for the fan speed is indicated. The optimal operating point 2 is the fan speed where the electrical energy consumption of the fan is minimised without risking an unacceptably high outlet temperature. Thus, at fan speeds below the optimal point 2 , the outlet temperature becomes too high, and at fan speeds above the optimal point 2 , the electrical energy consumption of the fan increases.
An effective range 3 of fan speeds is also shown in FIG. 2 . The effective range 3 is a range of fan speeds above the optimal point 2 , where the electrical energy consumption of the fan is acceptable. Accordingly, it is desirable to operate the rotational speed of the fan in such a manner that the rotational speed of the fan is within the effective range 3 . Under no circumstances should the rotational speed of the fan be allowed to fall below the optimal point 2 , but it is acceptable to operate the rotational speed of the fan in the effective range 3 immediately above the optimal point 2 . Accordingly, if the rotational speed of the fan decreases to falls below the optimal point 2 , the rotational speed of the fan should be increased rapidly and significantly for ensuring that the rotational speed is immediately increased to a level above the optimal point 2 . However, if the rotational speed of the fan increases to above the effective range 3 , the rotational speed of the fan should be decreased slowly and gradually for ensuring that the rotational speed is not decreased to a value below the optimal point 2 . Thus, FIG. 2 illustrates the asymmetry in control of the fan, said asymmetry having been described previously.
FIG. 3 also shows the graph of FIGS. 1 and 2 . In FIG. 3 a temperature dead zone 4 is illustrated. The dead zone 4 is a desired temperature range of the outlet temperature. Itit is desirable to control the vapour compression system, including the rotational speed of the fan, in such a manner that the outlet temperature is within the dead zone 4 . Furthermore, this may advantageously be obtained while controlling the rotational speed of the fan to be within the effective range 3 illustrated in FIG. 2 .
The dead zone 4 is delimited by a first temperature value 5 and a second temperature value 6 . The outlet temperature can be measured, and in response to the measured value, the fan speed can be adjusted in order to obtain temperature values which are within the dead zone 4 . However, the graph shown in FIGS. 1-3 is offset when the ambient temperature changes. Therefore, instead of simply measuring the outlet temperature and comparing it to the first temperature value 5 and the second temperature value 6 , the ambient temperature is also measured. The temperature difference is calculated, and the temperature difference is compared to a first threshold value, corresponding to the first temperature value 5 , and to a second threshold value, corresponding to the second temperature value 6 . In response to this comparison the rotational speed of the fan is controlled in the following manner.
If the temperature difference is larger than the first threshold value, corresponding to the outlet temperature being higher than the first temperature value 5 , the rotational speed of the fan is increased. This may, e.g., be done by jumping up the rotational speed or by ramping up the rotational speed. This is illustrated by zone 7 in FIG. 3 .
If the temperature difference is smaller than the first threshold value, but larger than the second threshold value, corresponding to the outlet temperature being within the dead zone, the rotational speed of the fan is maintained at the current speed. This is illustrated by zone 8 in FIG. 3 .
If the temperature difference is smaller than the second threshold value, corresponding to the outlet temperature being lower than the second temperature value 6 , the rotational speed of the fan is decreased. This is preferably done by ramping down the speed in order to avoid that zone 7 is entered. This situation is illustrated by zone 9 in FIG. 3 .
The dead zone 4 is a range of outlet temperatures where the rotational speed of the fan is kept constant. When the outlet temperature is above the dead zone 4 , the rotational speed of the fan is increased, preferably, e.g. jumped up or ramped up at a high rate, and when the outlet temperature is below the dead zone 4 , the rotational speed of the fan is decreased, preferably ramped down at a low rate.
FIG. 4 is a graph illustrating control of rotational speed of a fan according to two different aspects of control according to the invention, and in accordance with the method described above with reference to FIG. 3 .
The top graph shows outlet temperature as a function of time. The dead zone 4 , the first temperature value 5 and the second temperature value 6 are shown.
The middle graph and the lower graph show rotational speed of a fan as a function of time, according to two different control methods, and in response to the temperature variations shown in the top graph.
Initially the outlet temperature is below the dead zone 4 . Therefore, for the outlet temperature to increase and thereby enter the dead zone 4 , the rotational speed of the fan is ramped down, i.e. it is gradually decreased, as in the control aspect illustrated in the middle graph as well as in the control aspect illustrated in the lower graph.
At time 10 the outlet temperature reaches the second temperature value 6 , and thereby enters the dead zone 4 . In response to this, the rotational fan is maintained at a constant value as in the control aspect illustrated in the middle graph as well as in the control aspect illustrated in the lower graph. However, the outlet temperature continues to increase, and at time 11 the first temperature value 5 is reached, and the outlet temperature increases above the dead zone 4 . In response to this, the rotational speed of the fan is increased, for causing the outlet temperature to decrease and once again enter the dead zone 4 .
In the control aspect illustrated in the middle graph, the rotational speed of the fan is increased by jumping up the rotational speed, i.e. by abruptly increasing the rotational speed by a significant amount. Subsequently, the rotational speed is maintained at a constant level for a time period (“delay”), in order to allow the system to react to the jump in rotational speed of the fan. When the time period has elapsed, the outlet temperature is established being still above the dead zone 4 , and therefore the rotational speed of the fan is jumped up once again.
In the control aspect illustrated in the lower graph, the rotational speed is ramped up, i.e. it is gradually increased.
At time 12 the outlet temperature has decreased and reaches the first temperature value 5 , thereby entering the dead zone 4 . In response to this, the rotational speed of the fan is maintained constant as in the control aspect illustrated in the middle graph as well as in the control aspect illustrated in the lower graph.
At time 13 the outlet temperature reaches the second temperature value 6 , thereby decreasing below the dead zone 4 . In response to this, the rotational speed of the fan is ramped down as in the control aspect illustrated in the middle graph as well as in the control aspect illustrated in the lower graph.
At time 14 the outlet temperature once again reaches the second temperature value 6 , thereby entering the dead zone 4 . In response to this, the rotational speed of the fan is maintained constant as in the control aspect illustrated in the middle graph as well as in the control aspect illustrated in the lower graph.
At time 15 the outlet temperature once again reaches the first temperature value 5 , thereby increasing above the dead zone 4 , and once again the rotational speed of the fan is increased in response to this. In the control aspect illustrated in the middle graph, the rotational speed of the fan is jumped up, and in the control aspect illustrated in the lower graph, the rotational speed of the fan is ramped up, as described above.
Finally, at time 16 the outlet temperature once again reaches the first temperature value 5 , thereby entering the dead zone 4 . In response to this, the rotational speed of the fan is once again maintained constant.
In summary, the control aspect method illustrated in the middle graph is an asymmetric control aspect, in the sense that the rotational speed of the fan is increased rapidly and significantly if it is established that the outlet temperature is above the dead zone 4 , and the rotational speed of the fan is decreased carefully and gradually if it is established that the outlet temperature is below the dead zone 4 . The control aspect illustrated in the lower graph is symmetrical in the sense that the rotational speed of the fan is increased or decreased gradually when the outlet temperature is outside the dead zone 4 , regardless of whether the outlet temperature is above or below the dead zone 4 .
FIGS. 5-7 are three block diagrams, each illustrating a method for controlling a fan according to aspects of control according to the invention. In the control aspect illustrated in FIG. 5 , an asymmetric, but substantially linear, function is used for controlling the rotational speed of the fan in response to a measured outlet temperature.
In the control aspect illustrated in FIG. 6 , an aggressive scaling function, in the form of an exponential function, is used for determining the rotational speed of the fan in response to a measured outlet temperature.
In the control aspect illustrated in FIG. 7 , the function is identical to the function used in the control aspect illustrated in FIG. 5 . However, in the control aspect illustrated in FIG. 7 , a closed loop feedback is used.
Although various embodiments of the present invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.
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A method of controlling a fan of a vapor compression system is disclosed. The vapor compression system includes a compressor, a heat rejecting heat exchanger, e.g. in the form of a gas cooler or a condenser, an expansion device and an evaporator arranged in a refrigerant circuit. The fan is arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, e.g. in the form of an air flow. The method allows the electrical energy consumption of the fan to be reduced without risking instability of the vapor compression system.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Patent Application No. 62/098,012 for a Method and System for Improving Barcode Scanner Performance filed Dec. 30, 2014, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to barcode scanners and, more specifically, to a method and system to reduce unwanted barcode scans for items that require a weight measurement.
BACKGROUND
A barcode scanner may scan a barcode repeatedly as a barcoded item is dragged across an in-counter scanner. This creates a dilemma: does a duplicate barcode scan belong to an item scanned twice, or is it from a new item? The tolerance for these errors (i.e., singulation errors) is low, as they are frustrating in a retail-checkout setting.
In-counter scanners typically have a large field of view and multiple scan lines to capture barcodes in a variety of positions. Small barcode labels (e.g., Data-Bar barcodes found on fruits and vegetables), however, may not intersect well with the multiple scan lines. This fact may contribute to singulation errors.
To eliminate singulation errors, a scanner may ignore duplicate scans from the same barcode for some period (i.e., timeout period) after a barcode is first scanned. Timeout-periods work well in most scenarios but may not be sufficient for items requiring a weight measurement (especially when small barcodes are used).
Weight measurements may be made using a scale integrated with a scanner (i.e., scanner/scale) so that weighed items remain in the scanner's field of view during a measurement. This weight measurement, however, may require a weighed item to remain in the scan area longer than the timeout period. What is more, items with small barcodes may be easily positioned so that their barcode is not visible to the scanner. As a result, the timeout period may be allowed to expire as the item is weighed, and the barcode may be re-scanned as the item is removed from the scale. A need, therefore, exists for a method and system to improve a barcode-scanner's ability to minimize multiple scan errors for items weighed during checkout.
SUMMARY
Accordingly, in one aspect, the present invention embraces a computer-implemented method for ignoring duplicate barcode scans. The method includes the step of receiving an item's first barcode scan from a barcode scanner communicatively coupled with a computer. The method also includes the step of determining from the first barcode scan the scanned-item's type. Further, the method includes the step of initiating a scale-timeout mode if the scanned-item's type requires a weight measurement. During the scale time-out mode, the method includes the step of comparing a subsequent barcode scan to an ignore list stored in a computer-readable memory, and if the subsequent barcode scan matches at least part of an item in the ignore list then it is ignored. For as long as the scale is non-idle (i.e., active), the ignore list is retained. When the scale first indicates that it is idle, however, timeout periods begin for barcodes in the ignore list. When a timeout period expires for a barcode, the barcode is removed from the ignore list.
In another aspect, the present invention embraces a computer-implemented method for ignoring multiple barcode scans of the same item. The method includes the step of receiving an item's first barcode scan from a barcode scanner communicatively coupled with a computer. The method further includes the step of initiating a scale-timeout mode if the scanned-item's type is a variable-weight type. During the scale-timeout mode, subsequent barcode scans are compared with the first barcode scan, and any subsequent barcode scans that match, at least part of, the first barcode scan are ignored.
In a possible embodiment of the computer-implemented method, the scale signal is monitored continuously (or as rapidly as is practical) to detect a change in state. The scale-timeout mode continues as long at the scale is active. While in the scale-timeout mode, a list of scanned barcodes (i.e., ignore list) is maintained. When the scale becomes idle, a timeout-period is started and barcodes in the ignore list may be removed as the timeout-period for each barcode expires.
In yet another aspect, the present invention embraces a scanner/scale system. The scanner/scale system includes a barcode scanner for scanning barcodes of items within a field of view. The system also includes a scale for measuring the weight of items placed on a measurement platform. The measurement platform is configured to position the items within the barcode scanner's field of view. The system further includes a computing device with a processor that is communicatively coupled to the barcode scanner and the scale. The processor can execute a barcode-ignore program stored on a computer readable memory that is accessible to the computing device. The barcode-ignore program configures the processor to (i) receive a scanned barcode from the barcode scanner, (ii) determine an item type from the scanned barcode, (iii) receive a scale signal from the scale, and (iv) use the item type and the scale signal to adjust a timeout mode. The timeout mode, includes a timeout period during which repetitively scanned barcodes are ignored.
The foregoing illustrative summary, as well as other exemplary objectives and/or advantages of the invention, and the manner in which the same are accomplished, are further explained within the following detailed description and its accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a state diagram of an exemplary scale indicating the active and idle scale conditions.
FIG. 2 depicts a block diagram of an exemplary scanner/scale system.
FIG. 3 depicts a flowchart of the barcode-transmission logic used in scale-timeout mode.
FIG. 4 depicts a flowchart of an exemplary computer implemented method for ignoring duplicate barcode scans.
DETAILED DESCRIPTION
The present invention embraces a method and system to eliminate duplicate barcode scans of the same item during a weight measurement. The invention is directed towards scanner/scale systems with indicia readers and weight scales integrated so an item occupies the same area during a weight measurement as it does during a barcode scan. Typically, such systems are further exemplified by in-counter scanner/scales so items for purchase can be scanned and/or weighed conveniently, typically in a fluid motion from a loading belt to a bagging area.
Standardized barcode symbols printed on product packaging provide an effective means to encode information about a product. Barcode scanners are devices that use optical methods to decode printed barcodes (e.g., linear barcode, QR code, etc.). There are two broad categories of barcode scanners. One category uses imaging (typically with electronic cameras with or without a light source). Here, an image of a barcode is transmitted to a computer that processes the digital image to obtain (i.e., decode) the encoded barcode information. The other category of scanner uses a light beam from a light source (e.g., laser diode) scans by traversing across the elements (i.e., bars and spaces) of the barcode to produce amplitude-modulated reflected light. This light can be sensed and demodulated to derive an electronic signal corresponding to the barcode. The electronic signal can then be processed by a processor to decode the barcode. Either the imaging scanner or the laser scanner may be used successfully and in some systems both are employed to add versatility.
The majority of laser scanners in use today, particular in retail environments, employ lenses and moving (i.e., rotating or oscillating) mirrors and/or other optical elements to focus and direct/scan laser beams to and from barcode symbols during scanning operations. In demanding retail-scanning environments, it is common for such systems to have both bottom and side-scanning windows to enable highly aggressive scanner performance, whereby the cashier need only drag a barcoded item past these scanning windows for the barcode thereon to be automatically read with minimal assistance of the cashier or checkout personnel. Such dual scanning window systems are typically referred to as “bioptical” laser scanning systems. These systems employ two sets of optics positioned behind bottom and side-scanning windows integrated into the checkout counter. Examples of polygon-based bioptical laser scanning systems are disclosed in U.S. Pat. Nos. 8,561,905 and 7,422,156, each incorporated herein by reference in its entirety.
Laser based bioptical scanners are well suited for this invention. The invention, however, is not limited to these systems. The invention could be applied to single plane laser scanning systems or to single/multi-plane image/camera-based scanning systems as well.
Scanner/scale systems at a retail checkout allow for fast and easy gathering of product information during check out. The barcoded information nominally represents item number of the Stock Keeping Unit (SKU) used for price look-up, however may also provide stocking/purchasing systems information to assist a store owner with understanding the store's inventory and plan for future purchases. While quantity is typically implied by the packaging on which the barcode is printed, bulk items without packaging (e.g., fruits and vegetables) may have barcodes as well (e.g., GS1 DataBar). Often a weight measurement for these items is necessary to supplement the barcoded SKU to compute a price. For these items, the integrated scale may be used to provide this extra information. The scales are often integrated so the item is weighed with only a slight modification to the normal scan process.
To scan an item, a user positions the barcode within the scanner's field of view (e.g., scan line of a laser scanner or camera aperture for an imager). The scanner's high scan rates and multiple fields-of-view help ease the positioning requirements for scanning. Positioning a barcode towards a scan window will typically ensure a scan. Typically, this scan window is integrated into the checkout counter between an item feed belt or gathering area and the item take-away bagging area. A user typically drags an item to be scanned across the window as the user moves the item into the bagging area. The item is dragged with its barcode so that at least one field of view “sees” the barcode.
Dragging items across the scan window may cause multiple scans since the item is likely to encounter a scan from more than one scan line or camera aperture, multiple scans from the same scan line or camera aperture, or both. In these cases, a computer (e.g., as part of an automatic input system) must process (e.g., using a processor) the repeated scans to prevent a single item from being output multiple times. Configurable timeout periods based on optical inputs have been commonly devised to block these duplicate scans. In gateless, triggerless scanning designs, these timeout periods may be based on optical inputs to devices that continuously search for decodable data.
A timeout period is initiated after a barcode is read (i.e., scanned). After a first barcode scan, the barcode is added to an ignore list stored in a computer readable memory (e.g., hard drive, RAM, etc.) during the timeout period, subsequent scans are compared to the ignore list contents. If a subsequent scan matches (at least part of) a barcode in the ignore list, then the subsequently scanned barcode is ignored or deleted. The timeout period must expire before the same barcode can be transmitted again to the host device. Whenever a duplicate scan occurs, the timeout period may be restarted to ensure that barcode has left the scan area before allowing the same barcode to be transmitted.
As an example, suppose the scanner decodes and transmits a barcode attached to a bunch of bananas that has just entered the scanner's field of view. The scan starts a timeout of 400 milliseconds (i.e., msec). Next, the same barcode is scanned and decoded (but not transmitted) several more times in rapid succession. Each time, the scanner resets the timeout to 400 msec and the banana barcode is kept in the ignore list.
This short timeout (i.e., regular mode) eliminates most duplicate scans in normal situations, however may not be sufficient for items that also require a weight measurement. Here, an item rests in the scan region during a weight measurement and the barcode may be coincidentally stationary in a region without an optically useful field of view. As the item is weighed, the regular-mode timeout may expire. When the item is removed from the scale, it may reencounter one or more scan lines/fields of view, and if the timeout has expired, these subsequent scans may be transmitted to the host device, resulting in errors. A different timeout mode (i.e., scale-timeout mode) having different parameters for singulation (e.g., different timeout periods, perpetual timeout periods, etc.) is desirable for items that require a weight measurement.
The duplicate scan problem for items requiring a weight measurement is related to the item's interaction with the scale (e.g., lingering in the scan area during a weight measurement with a barcode hidden from the scanner). After scanning a weighed item, examining the scale's condition may help to indicate the position of the object. This heuristic may be used to adjust a scale-timeout period or switch between modes of operation (e.g., regular mode vs. scale-timeout mode).
An integrated scale may use electrical or mechanical means to determine the weight or mass of an item. Electronic scales for retail typically use at least one strain gauge to create or adjust an electronic signal in proportion to an items weight. A host device (e.g., computing device) may receive this electronic signal directly (e.g., weight measurement) or may receive the weight reported with other scale status information in a message sent via a communication protocol (e.g., scale-stability message).
For a scale integrated with in-counter barcode scanner, a scale signal evaluated over a period may provide a good estimate of the item's location. As shown in FIG. 1 , the scale may occupy one of three states 10 , 11 , 12 . Two states 11 , 12 indicate that the scale is active 5 and one state 10 indicates that the scale is idle (i.e., not active) 1 . A scale signal indicating that the scale is active 5 suggests that the item is likely to be in scan area. A scale signal indicating that the scale is idle 1 indicates that nothing is likely to be in the scan area. The scale states may be defined by both the instantaneous weight and the weight change within some period. For example, if the scale indicates a non-zero weight and a stable weight (i.e., not changing as compared to some threshold over a period) 11 , then an item is most likely resting on the scale. If the weight is unstable (i.e., changing over a period) 12 then an item has likely either just been placed on the scale or has just been removed from the scale. In either case, the item may still be in the scan area. If the scale indicates a stable, zero weight 10 , however, the item is likely to be outside the scan area.
FIG. 2 illustrates a portion of an exemplary scanner/scale system with an integrated barcode scanner and scale. An item (e.g., a banana bunch) 15 is placed on the scale's platter 18 (i.e., measurement platform) for a weight measurement. The banana bunch 15 and its barcode 16 are also positioned in the barcode scanner's field of view 17 when placed on the measurement platform 18 for a weight measurement by the scale 19 . A first barcode scan is captured by the barcode scanner and transmitted to a computing device 21 having an integrated processor 20 . The scale 19 sends a scale signal indicating an active scale 5 to the processor 20 . The processor is running a barcode-ignore program 22 stored in a computer readable memory 23 . The barcode-ignore program configures the processor to reject any subsequent barcode scans that match the first barcode scan (i.e., scale-timeout mode).
The scale-timeout mode is illustrated in FIG. 3 . The barcode-transmission logic illustrated in the flowchart demonstrates how a barcode is first evaluated for duplicates prior to its transmission. The scale-timeout mode is activated when a barcode indicates that scanned-item's type is a type that requires a weight measurement.
During the scale-timeout mode 42 , a decoded barcode is received 30 from the barcode scanner 24 . The received barcode 30 is first compared to an ignore list stored on a computer readable memory 23 . If the received barcode 30 is not found in the ignore list, then the barcode may be added to the ignore list 33 and transmitted 34 without risk of duplication. If the barcode matches an item in the ignore list, however, then the received barcode is ignored, deleted, or otherwise not transmitted to another device 32 .
Barcode rejection may occur when the received barcode matches an ignore-list item completely. Alternatively, the received barcode may partially match an ignore-list item. The threshold for rejection may be adjusted based on the application. Items in the ignore list may include partially scanned barcodes, duplicate barcodes, and/or information related to ignore list items (or derived from the ignore list items). Barcodes placed in the ignore list during a scale-timeout mode may expire (i.e., be removed from the list) after a period. This period may be adjusted for the application to ensure there are no duplicate scans. Items in the ignore list may all have the same expiration conditions or could have different expiration conditions based on some other parameter, such as barcode type.
Ignore-list items may remain in the ignore list as long as the system remains in the scale-timeout mode. The ignore-list's contents may be emptied at the end of the scale-timeout mode (when the scale becomes inactive). The items may be removed from the list all at once or each may be removed from the list after some timeout period has expired. This timeout period may be the same or different for each item in the list and may be adjustable based on the item type.
Alternatively, when the scale-timeout mode ends, the ignore list contents may be transferred or reused. For example, the contents of the ignore list may become the initial conditions for a similar barcode transmission logic in a regular mode. The regular mode being a timeout mode not involving the scale and having different ignore list parameters (e.g., timeout period).
Information about the barcode type and information from the scale may determine when the system, graphically depicted in FIG. 2 , enters into (and exits from) a scale-time out mode. FIG. 4 depicts a flow chart for a computer-implemented method for ignoring duplicate barcode scans using a scale timeout mode. This method may be part of a barcode-ignore software program 22 stored on a computer readable memory 23 and executed by a processor 20 integrated in a computing device 21 that is communicatively couple to a barcode scanner 24 and a scale 19 . The method starts by receiving a barcode 40 from a barcode scanner 24 (e.g., a laser scanner or a barcode imager). The barcode is typically a linear barcode but may be another type (e.g., QR code, stacked barcode, etc.). The barcode is typically printed and affixed to the item of interest but could also be displayed and/or apart from the item of interest. The barcode may be received 40 as a decoded message or a signal that requires decoding. The decoded barcode message is analyzed to determine the item's type 41 . For example, an item is the type that requires a weight measurement as part of the checkout process (e.g., fruits, vegetables, etc.). If the barcode indicates that the item it is associated with requires a weight measurement then the system enters into a scale-timeout mode 42 . In this mode, special care is taken to avoid duplicate scans of items requiring extra time in the scan areas for a weight measurement. The details of the scale-time out mode are illustrated in FIG. 3 . Scale-timeout mode continues until the scale becomes idle.
The system monitors the scale to determine when the scale becomes idle 43 . When the scale becomes idle the items may be removed from the ignore list after some timeout period. As such, a timeout period is started 44 when the scale becomes inactive and allowed to expire before returning the system to a regular mode 45 .
To supplement the present disclosure, this application incorporates entirely by reference the following commonly assigned patents, patent application publications, and patent applications:
U.S. Pat. No. 6,832,725; U.S. Pat. No. 7,128,266; U.S. Pat. No. 7,159,783; U.S. Pat. No. 7,413,127; U.S. Pat. No. 7,726,575; U.S. Pat. No. 8,294,969; U.S. Pat. No. 8,317,105; U.S. Pat. No. 8,322,622; U.S. Pat. No. 8,366,005; U.S. Pat. No. 8,371,507; U.S. Pat. No. 8,376,233; U.S. Pat. No. 8,381,979; U.S. Pat. No. 8,390,909; U.S. Pat. No. 8,408,464; U.S. Pat. No. 8,408,468; U.S. Pat. No. 8,408,469; U.S. Pat. No. 8,424,768; U.S. Pat. No. 8,448,863; U.S. Pat. No. 8,457,013; U.S. Pat. No. 8,459,557; U.S. Pat. No. 8,469,272; U.S. Pat. No. 8,474,712; U.S. Pat. No. 8,479,992; U.S. Pat. No. 8,490,877; U.S. Pat. No. 8,517,271; U.S. Pat. No. 8,523,076; U.S. Pat. No. 8,528,818; U.S. Pat. No. 8,544,737; U.S. Pat. No. 8,548,242; U.S. Pat. No. 8,548,420; U.S. Pat. No. 8,550,335; U.S. Pat. No. 8,550,354; U.S. Pat. No. 8,550,357; U.S. Pat. No. 8,556,174; U.S. Pat. No. 8,556,176; U.S. Pat. No. 8,556,177; U.S. Pat. No. 8,559,767; U.S. Pat. No. 8,599,957; U.S. Pat. No. 8,561,895; U.S. Pat. No. 8,561,903; U.S. Pat. No. 8,561,905; U.S. Pat. No. 8,565,107; U.S. Pat. No. 8,571,307; U.S. Pat. No. 8,579,200; U.S. Pat. No. 8,583,924; U.S. Pat. No. 8,584,945; U.S. Pat. No. 8,587,595; U.S. Pat. No. 8,587,697; U.S. Pat. No. 8,588,869; U.S. Pat. No. 8,590,789; U.S. Pat. No. 8,596,539; U.S. Pat. No. 8,596,542; U.S. Pat. No. 8,596,543; U.S. Pat. No. 8,599,271; U.S. Pat. No. 8,599,957; U.S. Pat. No. 8,600,158; U.S. Pat. No. 8,600,167; U.S. Pat. No. 8,602,309; U.S. Pat. No. 8,608,053; U.S. Pat. No. 8,608,071; U.S. Pat. No. 8,611,309; U.S. Pat. No. 8,615,487; U.S. Pat. No. 8,616,454; U.S. Pat. No. 8,621,123; U.S. Pat. No. 8,622,303; U.S. Pat. No. 8,628,013; U.S. Pat. No. 8,628,015; U.S. Pat. No. 8,628,016; U.S. Pat. No. 8,629,926; U.S. Pat. No. 8,630,491; U.S. Pat. No. 8,635,309; U.S. Pat. No. 8,636,200; U.S. Pat. No. 8,636,212; U.S. Pat. No. 8,636,215; U.S. Pat. No. 8,636,224; U.S. Pat. No. 8,638,806; U.S. Pat. No. 8,640,958; U.S. Pat. No. 8,640,960; U.S. Pat. No. 8,643,717; U.S. Pat. No. 8,646,692; U.S. Pat. No. 8,646,694; U.S. Pat. No. 8,657,200; U.S. Pat. No. 8,659,397; U.S. Pat. No. 8,668,149; U.S. Pat. No. 8,678,285; U.S. Pat. No. 8,678,286; U.S. Pat. No. 8,682,077; U.S. Pat. No. 8,687,282; U.S. Pat. No. 8,692,927; U.S. Pat. No. 8,695,880; U.S. Pat. No. 8,698,949; U.S. Pat. No. 8,717,494; U.S. Pat. No. 8,717,494; U.S. Pat. No. 8,720,783; U.S. Pat. No. 8,723,804; U.S. Pat. No. 8,723,904; U.S. Pat. No. 8,727,223; U.S. Pat. No. D702,237; U.S. Pat. No. 8,740,082; U.S. Pat. No. 8,740,085; U.S. Pat. No. 8,746,563; U.S. Pat. No. 8,750,445; U.S. Pat. No. 8,752,766; U.S. Pat. No. 8,756,059; U.S. Pat. No. 8,757,495; U.S. Pat. No. 8,760,563; U.S. Pat. No. 8,763,909; U.S. Pat. No. 8,777,108; U.S. Pat. No. 8,777,109; U.S. Pat. No. 8,779,898; U.S. Pat. No. 8,781,520; U.S. Pat. No. 8,783,573; U.S. Pat. No. 8,789,757; U.S. Pat. No. 8,789,758; U.S. Pat. No. 8,789,759; U.S. Pat. No. 8,794,520; U.S. Pat. No. 8,794,522; U.S. Pat. No. 8,794,525; U.S. Pat. No. 8,794,526; U.S. Pat. No. 8,798,367; U.S. Pat. No. 8,807,431; U.S. Pat. No. 8,807,432; U.S. Pat. No. 8,820,630; U.S. Pat. No. 8,822,848; U.S. Pat. No. 8,824,692; U.S. Pat. No. 8,824,696; U.S. Pat. No. 8,842,849; U.S. Pat. No. 8,844,822; U.S. Pat. No. 8,844,823; U.S. Pat. No. 8,849,019; U.S. Pat. No. 8,851,383; U.S. Pat. No. 8,854,633; U.S. Pat. No. 8,866,963; U.S. Pat. No. 8,868,421; U.S. Pat. No. 8,868,519; U.S. Pat. No. 8,868,802; U.S. Pat. No. 8,868,803; U.S. Pat. No. 8,870,074; U.S. Pat. No. 8,879,639; U.S. Pat. No. 8,880,426; U.S. Pat. No. 8,881,983; U.S. Pat. No. 8,881,987; U.S. Pat. No. 8,903,172; U.S. Pat. No. 8,908,995; U.S. Pat. No. 8,910,870; U.S. Pat. No. 8,910,875; U.S. Pat. No. 8,914,290; U.S. Pat. No. 8,914,788; U.S. Pat. No. 8,915,439; U.S. Pat. No. 8,915,444; U.S. Pat. No. 8,916,789; U.S. Pat. No. 8,918,250; U.S. Pat. No. 8,918,564; U.S. Pat. No. 8,925,818; U.S. Pat. No. 8,939,374; U.S. Pat. No. 8,942,480; U.S. Pat. No. 8,944,313; U.S. Pat. No. 8,944,327; U.S. Pat. No. 8,944,332; U.S. Pat. No. 8,950,678; U.S. Pat. No. 8,967,468; U.S. Pat. No. 8,971,346; U.S. Pat. No. 8,976,030; U.S. Pat. No. 8,976,368; U.S. Pat. No. 8,978,981; U.S. Pat. No. 8,978,983; U.S. Pat. No. 8,978,984; U.S. Pat. No. 8,985,456; U.S. Pat. No. 8,985,457; U.S. Pat. No. 8,985,459; U.S. Pat. No. 8,985,461; U.S. Pat. No. 8,988,578; U.S. Pat. No. 8,988,590; U.S. Pat. No. 8,991,704; U.S. Pat. No. 8,996,194; U.S. Pat. No. 8,996,384; U.S. Pat. No. 9,002,641; U.S. Pat. No. 9,007,368; U.S. Pat. No. 9,010,641; U.S. Pat. No. 9,015,513; U.S. Pat. No. 9,016,576; U.S. Pat. No. 9,022,288; U.S. Pat. No. 9,030,964; U.S. Pat. No. 9,033,240; U.S. Pat. No. 9,033,242; U.S. Pat. No. 9,036,054; U.S. Pat. No. 9,037,344; U.S. Pat. No. 9,038,911; U.S. Pat. No. 9,038,915; U.S. Pat. No. 9,047,098; U.S. Pat. No. 9,047,359; U.S. Pat. No. 9,047,420; U.S. Pat. No. 9,047,525; U.S. Pat. No. 9,047,531; U.S. Pat. No. 9,053,055; U.S. Pat. No. 9,053,378; U.S. Pat. No. 9,053,380; U.S. Pat. No. 9,058,526; U.S. Pat. No. 9,064,165; U.S. Pat. No. 9,064,167; U.S. Pat. No. 9,064,168; U.S. Pat. No. 9,064,254; U.S. Pat. No. 9,066,032; U.S. Pat. No. 9,070,032; U.S. Design Pat. No. D716,285; U.S. Design Pat. No. D723,560; U.S. Design Pat. No. D730,357; U.S. Design Pat. No. D730,901; U.S. Design Pat. No. D730,902; U.S. Design Pat. No. D733,112; U.S. Design Pat. No. D734,339; International Publication No. 2013/163789; International Publication No. 2013/173985; International Publication No. 2014/019130; International Publication No. 2014/110495; U.S. Patent Application Publication No. 2008/0185432; U.S. Patent Application Publication No. 2009/0134221; U.S. Patent Application Publication No. 2010/0177080; U.S. Patent Application Publication No. 2010/0177076; U.S. Patent Application Publication No. 2010/0177707; U.S. Patent Application Publication No. 2010/0177749; U.S. Patent Application Publication No. 2010/0265880; U.S. Patent Application Publication No. 2011/0202554; U.S. Patent Application Publication No. 2012/0111946; U.S. Patent Application Publication No. 2012/0168511; U.S. Patent Application Publication No. 2012/0168512; U.S. Patent Application Publication No. 2012/0193423; U.S. Patent Application Publication No. 2012/0203647; U.S. Patent Application Publication No. 2012/0223141; U.S. Patent Application Publication No. 2012/0228382; U.S. Patent Application Publication No. 2012/0248188; U.S. Patent Application Publication No. 2013/0043312; U.S. Patent Application Publication No. 2013/0082104; U.S. Patent Application Publication No. 2013/0175341; U.S. Patent Application Publication No. 2013/0175343; U.S. Patent Application Publication No. 2013/0257744; U.S. Patent Application Publication No. 2013/0257759; U.S. Patent Application Publication No. 2013/0270346; U.S. Patent Application Publication No. 2013/0287258; U.S. Patent Application Publication No. 2013/0292475; U.S. Patent Application Publication No. 2013/0292477; U.S. Patent Application Publication No. 2013/0293539; U.S. Patent Application Publication No. 2013/0293540; U.S. Patent Application Publication No. 2013/0306728; U.S. Patent Application Publication No. 2013/0306731; U.S. Patent Application Publication No. 2013/0307964; U.S. Patent Application Publication No. 2013/0308625; U.S. Patent Application Publication No. 2013/0313324; U.S. Patent Application Publication No. 2013/0313325; U.S. Patent Application Publication No. 2013/0342717; U.S. Patent Application Publication No. 2014/0001267; U.S. Patent Application Publication No. 2014/0008439; U.S. Patent Application Publication No. 2014/0025584; U.S. Patent Application Publication No. 2014/0034734; U.S. Patent Application Publication No. 2014/0036848; U.S. Patent Application Publication No. 2014/0039693; U.S. Patent Application Publication No. 2014/0042814; U.S. Patent Application Publication No. 2014/0049120; U.S. Patent Application Publication No. 2014/0049635; U.S. Patent Application Publication No. 2014/0061306; U.S. Patent Application Publication No. 2014/0063289; U.S. Patent Application Publication No. 2014/0066136; U.S. Patent Application Publication No. 2014/0067692; U.S. Patent Application Publication No. 2014/0070005; U.S. Patent Application Publication No. 2014/0071840; U.S. Patent Application Publication No. 2014/0074746; U.S. Patent Application Publication No. 2014/0076974; U.S. Patent Application Publication No. 2014/0078341; U.S. Patent Application Publication No. 2014/0078345; U.S. Patent Application Publication No. 2014/0097249; U.S. Patent Application Publication No. 2014/0098792; U.S. Patent Application Publication No. 2014/0100813; U.S. Patent Application Publication No. 2014/0103115; U.S. Patent Application Publication No. 2014/0104413; U.S. Patent Application Publication No. 2014/0104414; U.S. Patent Application Publication No. 2014/0104416; U.S. Patent Application Publication No. 2014/0104451; U.S. Patent Application Publication No. 2014/0106594; U.S. Patent Application Publication No. 2014/0106725; U.S. Patent Application Publication No. 2014/0108010; U.S. Patent Application Publication No. 2014/0108402; U.S. Patent Application Publication No. 2014/0110485; U.S. Patent Application Publication No. 2014/0114530; U.S. Patent Application Publication No. 2014/0124577; U.S. Patent Application Publication No. 2014/0124579; U.S. Patent Application Publication No. 2014/0125842; U.S. Patent Application Publication No. 2014/0125853; U.S. Patent Application Publication No. 2014/0125999; U.S. Patent Application Publication No. 2014/0129378; U.S. Patent Application Publication No. 2014/0131438; U.S. Patent Application Publication No. 2014/0131441; U.S. Patent Application Publication No. 2014/0131443; U.S. Patent Application Publication No. 2014/0131444; U.S. Patent Application Publication No. 2014/0131445; U.S. Patent Application Publication No. 2014/0131448; U.S. Patent Application Publication No. 2014/0133379; U.S. Patent Application Publication No. 2014/0136208; U.S. Patent Application Publication No. 2014/0140585; U.S. Patent Application Publication No. 2014/0151453; U.S. Patent Application Publication No. 2014/0152882; U.S. Patent Application Publication No. 2014/0158770; U.S. Patent Application Publication No. 2014/0159869; U.S. Patent Application Publication No. 2014/0166755; U.S. Patent Application Publication No. 2014/0166759; U.S. Patent Application Publication No. 2014/0168787; U.S. Patent Application Publication No. 2014/0175165; U.S. Patent Application Publication No. 2014/0175172; U.S. Patent Application Publication No. 2014/0191644; U.S. Patent Application Publication No. 2014/0191913; U.S. Patent Application Publication No. 2014/0197238; U.S. Patent Application Publication No. 2014/0197239; U.S. Patent Application Publication No. 2014/0197304; U.S. Patent Application Publication No. 2014/0214631; U.S. Patent Application Publication No. 2014/0217166; U.S. Patent Application Publication No. 2014/0217180; U.S. Patent Application Publication No. 2014/0231500; U.S. Patent Application Publication No. 2014/0232930; U.S. Patent Application Publication No. 2014/0247315; U.S. Patent Application Publication No. 2014/0263493; U.S. Patent Application Publication No. 2014/0263645; U.S. Patent Application Publication No. 2014/0267609; U.S. Patent Application Publication No. 2014/0270196; U.S. Patent Application Publication No. 2014/0270229; U.S. Patent Application Publication No. 2014/0278387; U.S. Patent Application Publication No. 2014/0278391; U.S. Patent Application Publication No. 2014/0282210; U.S. Patent Application Publication No. 2014/0284384; U.S. Patent Application Publication No. 2014/0288933; U.S. Patent Application Publication No. 2014/0297058; U.S. Patent Application Publication No. 2014/0299665; U.S. Patent Application Publication No. 2014/0312121; U.S. Patent Application Publication No. 2014/0319220; U.S. Patent Application Publication No. 2014/0319221; U.S. Patent Application Publication No. 2014/0326787; U.S. Patent Application Publication No. 2014/0332590; U.S. Patent Application Publication No. 2014/0344943; U.S. Patent Application Publication No. 2014/0346233; U.S. Patent Application Publication No. 2014/0351317; U.S. Patent Application Publication No. 2014/0353373; U.S. Patent Application Publication No. 2014/0361073; U.S. Patent Application Publication No. 2014/0361082; U.S. Patent Application Publication No. 2014/0362184; U.S. Patent Application Publication No. 2014/0363015; U.S. Patent Application Publication No. 2014/0369511; U.S. Patent Application Publication No. 2014/0374483; U.S. Patent Application Publication No. 2014/0374485; U.S. Patent Application Publication No. 2015/0001301; U.S. Patent Application Publication No. 2015/0001304; U.S. Patent Application Publication No. 2015/0003673; U.S. Patent Application Publication No. 2015/0009338; U.S. Patent Application Publication No. 2015/0009610; U.S. Patent Application Publication No. 2015/0014416; U.S. Patent Application Publication No. 2015/0021397; U.S. Patent Application Publication No. 2015/0028102; U.S. Patent Application Publication No. 2015/0028103; U.S. Patent Application Publication No. 2015/0028104; U.S. Patent Application Publication No. 2015/0029002; U.S. Patent Application Publication No. 2015/0032709; U.S. Patent Application Publication No. 2015/0039309; U.S. Patent Application Publication No. 2015/0039878; U.S. Patent Application Publication No. 2015/0040378; U.S. Patent Application Publication No. 2015/0048168; U.S. Patent Application Publication No. 2015/0049347; U.S. Patent Application Publication No. 2015/0051992; U.S. Patent Application Publication No. 2015/0053766; U.S. Patent Application Publication No. 2015/0053768; U.S. Patent Application Publication No. 2015/0053769; U.S. Patent Application Publication No. 2015/0060544; U.S. Patent Application Publication No. 2015/0062366; U.S. Patent Application Publication No. 2015/0063215; U.S. Patent Application Publication No. 2015/0063676; U.S. Patent Application Publication No. 2015/0069130; U.S. Patent Application Publication No. 2015/0071819; U.S. Patent Application Publication No. 2015/0083800; U.S. Patent Application Publication No. 2015/0086114; U.S. Patent Application Publication No. 2015/0088522; U.S. Patent Application Publication No. 2015/0096872; U.S. Patent Application Publication No. 2015/0099557; U.S. Patent Application Publication No. 2015/0100196; U.S. Patent Application Publication No. 2015/0102109; U.S. Patent Application Publication No. 2015/0115035; U.S. Patent Application Publication No. 2015/0127791; U.S. Patent Application Publication No. 2015/0128116; U.S. Patent Application Publication No. 2015/0129659; U.S. Patent Application Publication No. 2015/0133047; U.S. Patent Application Publication No. 2015/0134470; U.S. Patent Application Publication No. 2015/0136851; U.S. Patent Application Publication No. 2015/0136854; U.S. Patent Application Publication No. 2015/0142492; U.S. Patent Application Publication No. 2015/0144692; U.S. Patent Application Publication No. 2015/0144698; U.S. Patent Application Publication No. 2015/0144701; U.S. Patent Application Publication No. 2015/0149946; U.S. Patent Application Publication No. 2015/0161429; U.S. Patent Application Publication No. 2015/0169925; U.S. Patent Application Publication No. 2015/0169929; U.S. Patent Application Publication No. 2015/0178523; U.S. Patent Application Publication No. 2015/0178534; U.S. Patent Application Publication No. 2015/0178535; U.S. Patent Application Publication No. 2015/0178536; U.S. Patent Application Publication No. 2015/0178537; U.S. Patent Application Publication No. 2015/0181093; U.S. Patent Application Publication No. 2015/0181109; U.S. patent application Ser. No. 13/367,978 for a Laser Scanning Module Employing an Elastomeric U-Hinge Based Laser Scanning Assembly, filed Feb. 7, 2012 (Feng et al.); U.S. patent application No. 29/458,405 for an Electronic Device, filed Jun. 19, 2013 (Fitch et al.); U.S. patent application No. 29/459,620 for an Electronic Device Enclosure, filed Jul. 2, 2013 (London et al.); U.S. patent application No. 29/468,118 for an Electronic Device Case, filed Sep. 26, 2013 (Oberpriller et al.); U.S. patent application Ser. No. 14/150,393 for Indicia-reader Having Unitary Construction Scanner, filed Jan. 8, 2014 (Colavito et al.); U.S. patent application Ser. No. 14/200,405 for Indicia Reader for Size-Limited applications filed Mar. 7, 2014 (Feng et al.); U.S. patent application Ser. No. 14/231,898 for Hand-Mounted Indicia-Reading Device with Finger Motion Triggering filed Apr. 1, 2014 (Van Horn et al.); U.S. patent application No. 29/486,759 for an Imaging Terminal, filed Apr. 2, 2014 (Oberpriller et al.); U.S. patent application Ser. No. 14/257,364 for Docking System and Method Using Near Field Communication filed Apr. 21, 2014 (Showering); U.S. patent application Ser. No. 14/264,173 for Autofocus Lens System for Indicia Readers filed Apr. 29, 2014 (Ackley et al.); U.S. patent application Ser. No. 14/277,337 for MULTIPURPOSE OPTICAL READER, filed May 14, 2014 (Jovanovski et al.); U.S. patent application Ser. No. 14/283,282 for TERMINAL HAVING ILLUMINATION AND FOCUS CONTROL filed May 21, 2014 (Liu et al.); U.S. patent application Ser. No. 14/327,827 for a MOBILE-PHONE ADAPTER FOR ELECTRONIC TRANSACTIONS, filed Jul. 10, 2014 (Hejl); U.S. patent application Ser. No. 14/334,934 for a SYSTEM AND METHOD FOR INDICIA VERIFICATION, filed Jul. 18, 2014 (Hejl); U.S. patent application Ser. No. 14/339,708 for LASER SCANNING CODE SYMBOL READING SYSTEM, filed Jul. 24, 2014 (Xian et al.); U.S. patent application Ser. No. 14/340,627 for an AXIALLY REINFORCED FLEXIBLE SCAN ELEMENT, filed Jul. 25, 2014 (Rueblinger et al.); U.S. patent application Ser. No. 14/446,391 for MULTIFUNCTION POINT OF SALE APPARATUS WITH OPTICAL SIGNATURE CAPTURE filed Jul. 30, 2014 (Good et al.); U.S. patent application Ser. No. 14/452,697 for INTERACTIVE INDICIA READER, filed Aug. 6, 2014 (Todeschini); U.S. patent application Ser. No. 14/453,019 for DIMENSIONING SYSTEM WITH GUIDED ALIGNMENT, filed Aug. 6, 2014 (Li et al.); U.S. patent application Ser. No. 14/462,801 for MOBILE COMPUTING DEVICE WITH DATA COGNITION SOFTWARE, filed on Aug. 19, 2014 (Todeschini et al.); U.S. patent application Ser. No. 14/483,056 for VARIABLE DEPTH OF FIELD BARCODE SCANNER filed Sep. 10, 2014 (McCloskey et al.); U.S. patent application Ser. No. 14/513,808 for IDENTIFYING INVENTORY ITEMS IN A STORAGE FACILITY filed Oct. 14, 2014 (Singel et al.); U.S. patent application Ser. No. 14/519,195 for HANDHELD DIMENSIONING SYSTEM WITH FEEDBACK filed Oct. 21, 2014 (Laffargue et al.); U.S. patent application Ser. No. 14/519,179 for DIMENSIONING SYSTEM WITH MULTIPATH INTERFERENCE MITIGATION filed Oct. 21, 2014 (Thuries et al.); U.S. patent application Ser. No. 14/519,211 for SYSTEM AND METHOD FOR DIMENSIONING filed Oct. 21, 2014 (Ackley et al.); U.S. patent application Ser. No. 14/519,233 for HANDHELD DIMENSIONER WITH DATA-QUALITY INDICATION filed Oct. 21, 2014 (Laffargue et al.); U.S. patent application Ser. No. 14/519,249 for HANDHELD DIMENSIONING SYSTEM WITH MEASUREMENT-CONFORMANCE FEEDBACK filed Oct. 21, 2014 (Ackley et al.); U.S. patent application Ser. No. 14/527,191 for METHOD AND SYSTEM FOR RECOGNIZING SPEECH USING WILDCARDS IN AN EXPECTED RESPONSE filed Oct. 29, 2014 (Braho et al.); U.S. patent application Ser. No. 14/529,563 for ADAPTABLE INTERFACE FOR A MOBILE COMPUTING DEVICE filed Oct. 31, 2014 (Schoon et al.); U.S. patent application Ser. No. 14/529,857 for BARCODE READER WITH SECURITY FEATURES filed Oct. 31, 2014 (Todeschini et al.); U.S. patent application Ser. No. 14/398,542 for PORTABLE ELECTRONIC DEVICES HAVING A SEPARATE LOCATION TRIGGER UNIT FOR USE IN CONTROLLING AN APPLICATION UNIT filed Nov. 3, 2014 (Bian et al.); U.S. patent application Ser. No. 14/531,154 for DIRECTING AN INSPECTOR THROUGH AN INSPECTION filed Nov. 3, 2014 (Miller et al.); U.S. patent application Ser. No. 14/533,319 for BARCODE SCANNING SYSTEM USING WEARABLE DEVICE WITH EMBEDDED CAMERA filed Nov. 5, 2014 (Todeschini); U.S. patent application Ser. No. 14/535,764 for CONCATENATED EXPECTED RESPONSES FOR SPEECH RECOGNITION filed Nov. 7, 2014 (Braho et al.); U.S. patent application Ser. No. 14/568,305 for AUTO-CONTRAST VIEWFINDER FOR AN INDICIA READER filed Dec. 12, 2014 (Todeschini); U.S. patent application Ser. No. 14/573,022 for DYNAMIC DIAGNOSTIC INDICATOR GENERATION filed Dec. 17, 2014 (Goldsmith); U.S. patent application Ser. No. 14/578,627 for SAFETY SYSTEM AND METHOD filed Dec. 22, 2014 (Ackley et al.); U.S. patent application Ser. No. 14/580,262 for MEDIA GATE FOR THERMAL TRANSFER PRINTERS filed Dec. 23, 2014 (Bowles); U.S. patent application Ser. No. 14/590,024 for SHELVING AND PACKAGE LOCATING SYSTEMS FOR DELIVERY VEHICLES filed Jan. 6, 2015 (Payne); U.S. patent application Ser. No. 14/596,757 for SYSTEM AND METHOD FOR DETECTING BARCODE PRINTING ERRORS filed Jan. 14, 2015 (Ackley); U.S. patent application Ser. No. 14/416,147 for OPTICAL READING APPARATUS HAVING VARIABLE SETTINGS filed Jan. 21, 2015 (Chen et al.); U.S. patent application Ser. No. 14/614,706 for DEVICE FOR SUPPORTING AN ELECTRONIC TOOL ON A USER'S HAND filed Feb. 5, 2015 (Oberpriller et al.); U.S. patent application Ser. No. 14/614,796 for CARGO APPORTIONMENT TECHNIQUES filed Feb. 5, 2015 (Morton et al.); U.S. patent application No. 29/516,892 for TABLE COMPUTER filed Feb. 6, 2015 (Bidwell et al.); U.S. patent application Ser. No. 14/619,093 for METHODS FOR TRAINING A SPEECH RECOGNITION SYSTEM filed Feb. 11, 2015 (Pecorari); U.S. patent application Ser. No. 14/628,708 for DEVICE, SYSTEM, AND METHOD FOR DETERMINING THE STATUS OF CHECKOUT LANES filed Feb. 23, 2015 (Todeschini); U.S. patent application Ser. No. 14/630,841 for TERMINAL INCLUDING IMAGING ASSEMBLY filed Feb. 25, 2015 (Gomez et al.); U.S. patent application Ser. No. 14/635,346 for SYSTEM AND METHOD FOR RELIABLE STORE-AND-FORWARD DATA HANDLING BY ENCODED INFORMATION READING TERMINALS filed Mar. 2, 2015 (Sevier); U.S. patent application No. 29/519,017 for SCANNER filed Mar. 2, 2015 (Zhou et al.); U.S. patent application Ser. No. 14/405,278 for DESIGN PATTERN FOR SECURE STORE filed Mar. 9, 2015 (Zhu et al.); U.S. patent application Ser. No. 14/660,970 for DECODABLE INDICIA READING TERMINAL WITH COMBINED ILLUMINATION filed Mar. 18, 2015 (Kearney et al.); U.S. patent application Ser. No. 14/661,013 for REPROGRAMMING SYSTEM AND METHOD FOR DEVICES INCLUDING PROGRAMMING SYMBOL filed Mar. 18, 2015 (Soule et al.); U.S. patent application Ser. No. 14/662,922 for MULTIFUNCTION POINT OF SALE SYSTEM filed Mar. 19, 2015 (Van Horn et al.); U.S. patent application Ser. No. 14/663,638 for VEHICLE MOUNT COMPUTER WITH CONFIGURABLE IGNITION SWITCH BEHAVIOR filed Mar. 20, 2015 (Davis et al.); U.S. patent application Ser. No. 14/664,063 for METHOD AND application FOR SCANNING A BARCODE WITH A SMART DEVICE WHILE CONTINUOUSLY RUNNING AND DISPLAYING AN APPLICATION ON THE SMART DEVICE DISPLAY filed Mar. 20, 2015 (Todeschini); U.S. patent application Ser. No. 14/669,280 for TRANSFORMING COMPONENTS OF A WEB PAGE TO VOICE PROMPTS filed Mar. 26, 2015 (Funyak et al.); U.S. patent application Ser. No. 14/674,329 for AIMER FOR BARCODE SCANNING filed Mar. 31, 2015 (Bidwell); U.S. patent application Ser. No. 14/676,109 for INDICIA READER filed Apr. 1, 2015 (Huck); U.S. patent application Ser. No. 14/676,327 for DEVICE MANAGEMENT PROXY FOR SECURE DEVICES filed Apr. 1, 2015 (Yeakley et al.); U.S. patent application Ser. No. 14/676,898 for NAVIGATION SYSTEM CONFIGURED TO INTEGRATE MOTION SENSING DEVICE INPUTS filed Apr. 2, 2015 (Showering); U.S. patent application Ser. No. 14/679,275 for DIMENSIONING SYSTEM CALIBRATION SYSTEMS AND METHODS filed Apr. 6, 2015 (Laffargue et al.); U.S. patent application No. 29/523,098 for HANDLE FOR A TABLET COMPUTER filed Apr. 7, 2015 (Bidwell et al.); U.S. patent application Ser. No. 14/682,615 for SYSTEM AND METHOD FOR POWER MANAGEMENT OF MOBILE DEVICES filed Apr. 9, 2015 (Murawski et al.); U.S. patent application Ser. No. 14/686,822 for MULTIPLE PLATFORM SUPPORT SYSTEM AND METHOD filed Apr. 15, 2015 (Qu et al.); U.S. patent application Ser. No. 14/687,289 for SYSTEM FOR COMMUNICATION VIA A PERIPHERAL HUB filed Apr. 15, 2015 (Kohtz et al.); U.S. patent application No. 29/524,186 for SCANNER filed Apr. 17, 2015 (Zhou et al.); U.S. patent application Ser. No. 14/695,364 for MEDICATION MANAGEMENT SYSTEM filed Apr. 24, 2015 (Sewell et al.); U.S. patent application Ser. No. 14/695,923 for SECURE UNATTENDED NETWORK AUTHENTICATION filed Apr. 24, 2015 (Kubler et al.); U.S. patent application No. 29/525,068 for TABLET COMPUTER WITH REMOVABLE SCANNING DEVICE filed Apr. 27, 2015 (Schulte et al.); U.S. patent application Ser. No. 14/699,436 for SYMBOL READING SYSTEM HAVING PREDICTIVE DIAGNOSTICS filed Apr. 29, 2015 (Nahill et al.); U.S. patent application Ser. No. 14/702,110 for SYSTEM AND METHOD FOR REGULATING BARCODE DATA INJECTION INTO A RUNNING APPLICATION ON A SMART DEVICE filed May 1, 2015 (Todeschini et al.); U.S. patent application Ser. No. 14/702,979 for TRACKING BATTERY CONDITIONS filed May 4, 2015 (Young et al.); U.S. patent application Ser. No. 14/704,050 for INTERMEDIATE LINEAR POSITIONING filed May 5, 2015 (Charpentier et al.); U.S. patent application Ser. No. 14/705,012 for HANDS-FREE HUMAN MACHINE INTERFACE RESPONSIVE TO A DRIVER OF A VEHICLE filed May 6, 2015 (Fitch et al.); U.S. patent application Ser. No. 14/705,407 for METHOD AND SYSTEM TO PROTECT SOFTWARE-BASED NETWORK-CONNECTED DEVICES FROM ADVANCED PERSISTENT THREAT filed May 6, 2015 (Hussey et al.); U.S. patent application Ser. No. 14/707,037 for SYSTEM AND METHOD FOR DISPLAY OF INFORMATION USING A VEHICLE-MOUNT COMPUTER filed May 8, 2015 (Chamberlin); U.S. patent application Ser. No. 14/707,123 for APPLICATION INDEPENDENT DEX/UCS INTERFACE filed May 8, 2015 (Pape); U.S. patent application Ser. No. 14/707,492 for METHOD AND APPARATUS FOR READING OPTICAL INDICIA USING A PLURALITY OF DATA SOURCES filed May 8, 2015 (Smith et al.); U.S. patent application Ser. No. 14/710,666 for PRE-PAID USAGE SYSTEM FOR ENCODED INFORMATION READING TERMINALS filed May 13, 2015 (Smith); U.S. patent application No. 29/526,918 for CHARGING BASE filed May 14, 2015 (Fitch et al.); U.S. patent application Ser. No. 14/715,672 for AUGUMENTED REALITY ENABLED HAZARD DISPLAY filed May 19, 2015 (Venkatesha et al.); U.S. patent application Ser. No. 14/715,916 for EVALUATING IMAGE VALUES filed May 19, 2015 (Ackley); U.S. patent application Ser. No. 14/722,608 for INTERACTIVE USER INTERFACE FOR CAPTURING A DOCUMENT IN AN IMAGE SIGNAL filed May 27, 2015 (Showering et al.); U.S. patent application No. 29/528,165 for IN-COUNTER BARCODE SCANNER filed May 27, 2015 (Oberpriller et al.); U.S. patent application Ser. No. 14/724,134 for ELECTRONIC DEVICE WITH WIRELESS PATH SELECTION CAPABILITY filed May 28, 2015 (Wang et al.); U.S. patent application Ser. No. 14/724,849 for METHOD OF PROGRAMMING THE DEFAULT CABLE INTERFACE SOFTWARE IN AN INDICIA READING DEVICE filed May 29, 2015 (Barten); U.S. patent application Ser. No. 14/724,908 for IMAGING APPARATUS HAVING IMAGING ASSEMBLY filed May 29, 2015 (Barber et al.); U.S. patent application Ser. No. 14/725,352 for APPARATUS AND METHODS FOR MONITORING ONE OR MORE PORTABLE DATA TERMINALS (Caballero et al.); U.S. patent application No. 29/528,590 for ELECTRONIC DEVICE filed May 29, 2015 (Fitch et al.); U.S. patent application No. 29/528,890 for MOBILE COMPUTER HOUSING filed Jun. 2, 2015 (Fitch et al.); U.S. patent application Ser. No. 14/728,397 for DEVICE MANAGEMENT USING VIRTUAL INTERFACES CROSS-REFERENCE TO RELATED APPLICATIONS filed Jun. 2, 2015 (Caballero); U.S. patent application Ser. No. 14/732,870 for DATA COLLECTION MODULE AND SYSTEM filed Jun. 8, 2015 (Powilleit); U.S. patent application No. 29/529,441 for INDICIA READING DEVICE filed Jun. 8, 2015 (Zhou et al.); U.S. patent application Ser. No. 14/735,717 for INDICIA-READING SYSTEMS HAVING AN INTERFACE WITH A USER'S NERVOUS SYSTEM filed Jun. 10, 2015 (Todeschini); U.S. patent application Ser. No. 14/738,038 for METHOD OF AND SYSTEM FOR DETECTING OBJECT WEIGHING INTERFERENCES filed Jun. 12, 2015 (Amundsen et al.); U.S. patent application Ser. No. 14/740,320 for TACTILE SWITCH FOR A MOBILE ELECTRONIC DEVICE filed Jun. 16, 2015 (Bandringa); U.S. patent application Ser. No. 14/740,373 for CALIBRATING A VOLUME DIMENSIONER filed Jun. 16, 2015 (Ackley et al.); U.S. patent application Ser. No. 14/742,818 for INDICIA READING SYSTEM EMPLOYING DIGITAL GAIN CONTROL filed Jun. 18, 2015 (Xian et al.); U.S. patent application Ser. No. 14/743,257 for WIRELESS MESH POINT PORTABLE DATA TERMINAL filed Jun. 18, 2015 (Wang et al.); U.S. patent application No. 29/530,600 for CYCLONE filed Jun. 18, 2015 (Vargo et al); U.S. patent application Ser. No. 14/744,633 for IMAGING APPARATUS COMPRISING IMAGE SENSOR ARRAY HAVING SHARED GLOBAL SHUTTER CIRCUITRY filed Jun. 19, 2015 (Wang); U.S. patent application Ser. No. 14/744,836 for CLOUD-BASED SYSTEM FOR READING OF DECODABLE INDICIA filed Jun. 19, 2015 (Todeschini et al.); U.S. patent application Ser. No. 14/745,006 for SELECTIVE OUTPUT OF DECODED MESSAGE DATA filed Jun. 19, 2015 (Todeschini et al.); U.S. patent application Ser. No. 14/747,197 for OPTICAL PATTERN PROJECTOR filed Jun. 23, 2015 (Thuries et al.); U.S. patent application Ser. No. 14/747,490 for DUAL-PROJECTOR THREE-DIMENSIONAL SCANNER filed Jun. 23, 2015 (Jovanovski et al.); and U.S. patent application Ser. No. 14/748,446 for CORDLESS INDICIA READER WITH A MULTIFUNCTION COIL FOR WIRELESS CHARGING AND EAS DEACTIVATION, filed Jun. 24, 2015 (Xie et al.).
In the specification and/or figures, typical embodiments of the invention have been disclosed. The present invention is not limited to such exemplary embodiments. The use of the term “and/or” includes any and all combinations of one or more of the associated listed items. The figures are schematic representations and so are not necessarily drawn to scale. Unless otherwise noted, specific terms have been used in a generic and descriptive sense and not for purposes of limitation.
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A barcode scanner should output one scanned result per scanned item at checkout. Scanners with large scan areas and multiple scan lines may scan an item more than once as it is dragged through the scan area during the checkout process. A timeout period, during which duplicate scans are ignored, may prevent duplicate scans from being transmitted. Scanners with integrated weight scales may require the use of the scan area for a weight measurement. As a result, weighed items may linger in the scan area longer than the regular timeout period and may be re-scanned. The invention embraces a method and system for mitigating this problem by using information from the scanned barcode and information from the scale to affect how duplicate barcode scans are handled for items requiring a weight measurement and not adversely affected with speed of input as may result with gating and virtual gating with disable/enable scanning commands.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. application Ser. No. 11/519,729 filed on Sep. 12, 2006, now allowed, which is a division of U.S. application Ser. No. 10/616,665 filed Jul. 10, 2003, which issued on Oct. 24, 2006 as U.S. Pat. No. 7,124,788, the entire contents of all of which are incorporated herein by reference. Applicant claims the benefit of the prior U.S. applications.
[0002] This application is also related to U.S. application Ser. No. 11/519,728 filed on Sep. 12, 2006, which issued on Apr. 28, 2009 as U.S. Pat. No. 7,523,767.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to the filling of propellant and product into aerosol containers. More specifically, the invention relates to the filling of such containers of the bag-on-valve barrier pack type wherein a bag within the container is intended to hold the product to be dispensed and the remainder of the container is intended to hold the propellant.
[0005] 2. Description of Related Art
[0006] Aerosol containers of the barrier pack type include the well-known piston-in-can, and bag-in-can, embodiments. In one form of the latter, to which the present invention is directed, a flexible bag within the can may have its open end sealingly connected to the valve housing of the aerosol valve. Such embodiments are referred to as bag-on-valve systems. The product to be dispensed from the aerosol container commonly is filled into the flexible bag within the container and a liquified propellant or compressed gas is filled into the aerosol container outside of the bag between the bag outer wall and the inner wall of the can. When the aerosol valve is actuated, the propellant acts against the outer wall of the bag to force the product being dispensed out the aerosol valve to the environment outside the can. When the valve actuation ceases, of course, the product dispensing ceases.
[0007] Heretofore, the filling of the propellant into the container outside of the bag usually has been accomplished by filling propellant under the mounting cup or through the bottom of the container or by other complex schemes and structure. Such forms of propellant filling may require special and expensive filling equipment not owned by many commercial fillers who generally do own conventional pressure filling equipment to fill aerosol containers that do not include bag-on-valve systems. Such prior art forms of propellant filling can also be slow. In addition, prior art bag-on-valve systems do not generally permit product and propellant pressure filling to separately occur after the valve has been fixed to the container, such that the product and propellant cannot mix and the product filling cannot be shut off by imprecise stem positioning during product filling.
SUMMARY OF THE INVENTION
[0008] The present invention is intended to provide a simple and efficient means to pressure fill, in either order, propellant into the container outside of the bag and product (for example, a gel) into the bag in the container. Both operations are carried out by using mostly conventional pressure filling equipment after the bag has been sealingly mounted onto the housing or housing extension of the aerosol valve, or onto a fixture such as a wedge attached to the housing or housing extension. In this application, use of the term valve housing in connection with attachment of the bag shall also be taken to include attachment to such housing extension or fixture.
[0009] The propellant is filled from the filling head around the outside of the valve stem, between the valve stem and the mounting cup opening for the valve stem, over the top of the aerosol valve gasket, between the outside of the valve housing and the mounting cup, and down into the aerosol container outside of the bag mounted on the valve housing. The valve stem is depressed during this propellant filling operation so as to allow the aerosol valve gasket to bend to allow the propellant to flow above the gasket. At the same time, the filling head plugs the top dispensing opening of the valve stem so that the propellant only fills around the outside of the valve stem as described above.
[0010] The propellant filling operation as described above is generally well known for aerosol systems where there is no separate product bag already connected to the valve housing. The presence of such a connected product bag creates a serious impediment to such propellant filing in that the propellant passing around the stem also can pass between the bent valve gasket and the adjacent valve stem into the interior of the valve housing between the housing inner wall and the stem outer wall. This propellant would then have open access down into the product bag. This of course is highly disadvantageous in a bag-on-valve barrier pack wherein the product and propellant are to be maintained separate from one another.
[0011] A first aspect of the present invention allows the above-described propellant pressure filling to be used in a bag-on-valve system when the bag is already connected to the valve housing and the valve is fixed to the container. This is accomplished by providing an annular interior surface on the valve housing, for example a frusto-conical surface, and an annular exterior surface on the valve stem, for example a frusto-conical surface, the two said surfaces sealingly contacting each other only when the downward engagement pressure of the propellant filling head pushes the valve stem down the full distance to make such contact upon propellant filling. This downward pressure of the filling head will exceed the normal actuating pressure of the valve user in a downward or sideward direction on the stem to cause valve actuation and dispensing. Thus, the said respective frusto-conical surfaces of the stem and housing will not contact and seal against each other during normal valve actuation, since such contact and sealing during actuation would prevent product exiting the product bag into the valve housing and out the valve. The said respective frusto-conical surfaces of the stem and housing, upon sealing against each other during propellant filling, block propellant during filling entering into the product bag. Stem and housing surface profiles other than frusto-conical may be utilized as long as they effectively seal against each other to prevent propellant entering into the product bag.
[0012] In a second aspect of the present invention, the product bag in the can, sealingly connected to the valve housing, may be filled with product after (or before) the above-described propellant filling. The product filling is carried out through the dispensing conduit of the valve stem, with the valve stem being depressed a distance considerably less than during propellant filling but a sufficient amount to unseal the stem lateral orifices from the valve gasket. Product, for example a gel, flows down the center conduit of the valve stem, through the stem lateral orifices, into the valve housing interior, and down into the bag connected to the valve housing. The valve stem is held at a predetermined position of depression by a combination of a stem configuration and a novel insert adaptor configuration in the product filling head. More particularly, an annular indentation in the surface of the valve stem is utilized for engagement with spring loaded radial slides in the insert of the product filling head to maintain the position of the valve stem during filling. (Such stem indentations have been previously utilized, but for the unrelated purpose of securing actuator buttons). Without such a locking interengagement, the stem position can fluctuate under the pressure of product entering the valve stem. This fluctuation can either cause the stem to rise during product filling to partially or completely close the stem lateral orifices to prevent product filling, or may depress the stem so far as to seal the stem against the housing by the afore-described annular frusto-conical surfaces to prevent product filling down into the bag.
[0013] In a third aspect, the present invention discloses a novel method described above whereby propellant top pressure filling and product top pressure filling, in either order, are respectively carried out around the valve stem and through the valve stem into a bag-on-valve system wherein the product bag is already sealingly connected to the valve housing and the valve is already fixed to the container. The valve stem is in a first predetermined depressed position for propellant pressure filling and in a second predetermined depressed position for product pressure filling.
[0014] Other features and advantages of the present invention will be apparent from the following description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a partial axial cross-sectional view of a barrier pack, bag-on-valve, aerosol valve system of the present invention illustrating the aerosol valve in closed position;
[0016] FIG. 2 is a partial axial cross-sectional view of a bag-on valve aerosol valve system of the present invention corresponding to FIG. 1 , and wherein propellant is being filled into the aerosol container outside the bag by a propellant filling head;
[0017] FIG. 3 is an axial cross-sectional view of an aerosol valve stem of the present invention;
[0018] FIG. 4 is a partial axial cross-sectional view of a product filling head of the present invention positioned above and not yet engaged with the bag-on-valve aerosol valve system of FIG. 1 ;
[0019] FIG. 5 is a partial axial cross-sectional view corresponding to FIG. 4 but with the product filling head engaged with the valve stem and filling product into the bag-on-valve aerosol valve system of FIG. 1 ;
[0020] FIG. 6 is an enlarged axial cross-sectional view of slide member components of the product filling head of FIG. 5 ; and
[0021] FIG. 7 is an enlarged plan view of the bottom of the slide member components of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIG. 1 , aerosol valve system 10 includes a conventional closed container or can 11 (only the top portion of which is shown) with a top circular opening 12 within which is mounted aerosol mounting cup 13 . Centrally disposed within mounting cup 13 is aerosol valve 14 comprised of valve stem 15 and valve housing 16 . Valve housing 16 at the extension 16 a of its lower end has a flexible product bag 17 attached thereto in a sealingly connected manner. Flexible bag 17 may be comprised of polyethylene and/or other materials (including in laminated form) and is of well known structure. Bag 17 will contain the product to be dispensed from the aerosol container, and is a closed structure throughout except at the top of the bag where it is open only into the interior 18 of the valve housing. The bag 17 is welded all about its top opening to the outside of the lower extension 16 a of the valve housing. The bag 17 alternatively may be welded to a wedge or other fixture at the end of lower extension 16 a . Bag 17 , only partially shown, extends down into the container to near the bottom of the container in known fashion.
[0023] Aerosol valve stem 15 includes a central dispensing channel 19 and lateral side orifices 20 which are sealed by gasket 21 when aerosol valve 14 is closed by annular gasket 21 , which has a central opening. Spring 22 in the interior 18 of the valve housing 16 biases the valve stem 15 to a closed position as shown in FIG. 1 when the valve 14 is not actuated.
[0024] When propellant has been filled into aerosol container 11 into space 23 outside of bag 17 , and product has been filled into the interior 24 of bag 17 , the aerosol valve system is ready for use. When valve stem 15 is depressed (or moved laterally in the case of a tilt valve), gasket 21 unseals from stem lateral orifices 20 . The pressure of the propellant outside the bag 17 presses inward against flexible bag 17 to force the product in the bag up through the interior 18 of valve housing 16 , through lateral orifices 20 and up the stem dispensing channel 19 to the outside environment. As is known, an actuator (not shown, and of various forms) may be used to actuate valve stem 15 for dispensing. When stem 15 is no longer actuated, spring 22 forces valve stem 15 back to its position where gasket 21 again seals lateral orifices 20 to prevent further dispensing.
[0025] Now turning to the first aspect of the present invention, reference is made to FIG. 2 . Propellant filling head 30 is shown in filling position and is a conventional well-known apparatus. Valve stem 15 has been depressed by the filling head and plug member 31 plugs the top of stem dispensing conduit 19 to prevent propellant passing down through the conduit upon filling. Plug member 31 is an annular member with a plurality of radially outward holes 32 for filling propellant therethrough as shown by the arrows of FIG. 2 . Propellant is filled in known fashion down through filling head conduit 33 , through holes 32 , downward along the outside surface of stem 15 , through the circular opening 13 a in the top of mounting cup 13 through which stem 15 passes, outwardly over the top of valve sealing gasket 21 , downwardly along the outside of valve housing 16 , and finally into container space 23 outside of bag 17 . This method of filling is well known, and shown for example in U.S. Pat. No. 4,015,752 (Meuresch) and U.S. Pat. No. 4,015,757 (Meuresch), both issued Apr. 5, 1997 and incorporated herein by reference.
[0026] It will be noted that the above-described propellant filling occurs while product bag 17 is already positioned within container 11 and welded to extension 16 a of the valve housing. It is important in the barrier pack system of the present invention that the propellant during propellant filling not enter into bag 17 , which is solely for the containing of the product to be dispensed. This undesired entry would be possible with a standard valve stem 15 and valve housing 16 , in that, referring to FIG. 2 , propellant to be filled over the top of gasket 21 also can force its way between gasket 21 and the side of valve stem 15 at the annular area of contact 21 a with the stem 15 of the bent down gasket 21 shown in FIG. 2 . In the standard aerosol valve, the valve stem 15 does not make a sealing contact with the inner surface of the valve housing 16 during propellant filling, and thus the propellant forcing its way between bent gasket 21 and the side of valve stem 15 will pass downward through the interior 18 of valve housing 16 and downward into bag 17 . This is avoided in the present invention by providing a frusto-conical surface 34 extending around an intermediate portion of the valve stem (also see FIGS. 1 and 3 ), and frusto-conical surface 35 extending around the valve housing 16 (also see FIG. 1 ). Surface 34 may for example be at an angle of twenty degrees to the vertical, and surface 35 may be at the same angle to the vertical. In the closed position of the aerosol valve (see FIG. 1 ), the surfaces 34 and 35 are separated from one another. Likewise, when the aerosol valve is actuated in normal dispensing operation, valve stem 15 will not be depressed sufficiently to bring surfaces 34 and 35 into sealing contact by normal actuation pressure acting against the force of spring 22 . However, during propellant filling, the force of the propellant head against the valve stem 15 forces valve stem 15 to depress sufficiently such that frusto-conical surface 34 and 35 make annular plastic to plastic sealing contact with each other. Therefore no propellant being filled can pass down into the valve housing extension 16 a into the bag 17 since surfaces 34 and 35 seal off the bag from propellant entry. A conventional propellant filling head 30 may thereby be used despite the presence of product bag 17 in the container 11 . Filling head 30 also includes spacer cylinder 36 and annular gasket 37 , as well known.
[0027] Turning to the second, product filling, aspect of the present invention, reference is made to FIGS. 3 , 4 and 5 . It should be understood that product filling may occur after, or before, the propellant filling operation of FIG. 2 . FIG. 4 illustrates product filling head 40 before it is positioned on the aerosol valve system, and FIG. 5 illustrates product filling head 40 after it is in position for filling product into bag 17 in the can 11 . Filling head 40 includes outer annular wall 41 , inner annular product filling member 42 including product conduit 43 , spacer cylinder 44 , and product filing registration insert member 45 . Member 45 is comprised of U-shaped slide guides, and within the guides at for example positions one hundred and eighty degrees apart, radial slide members 47 and 48 (also see FIGS. 6 , 7 ) that are spring loaded by springs 49 and 50 to bias the slide members 47 and 48 radially inward and slightly into opening 46 . Springs 49 and 50 abut product filling member 42 on one end of each spring, the other end of each spring respectively fitting into openings 47 a and 48 a of slide members 47 , 48 . When product filling head 40 is positioned onto the aerosol valve system, the top outer portion 15 a of stem 15 fits into opening 46 and biases the slides 47 , 48 radially outward against the springs 49 and 50 . Referring to FIGS. 3 , 4 and 5 , stem 15 also has annular indent 60 about the circumference of valve stem 15 . Therefore, as the top outer portion 15 a of stem 15 passes upwardly through opening 46 , radial slides 47 and 48 snap into stem indent 60 under the force of the springs 49 and 50 . Curvilinear faces 51 and 52 (see FIGS. 6 , 7 ) of slide members 47 and 48 now encircle the stem 15 . At this position, as shown in FIG. 5 , valve stem 15 is in a downwardly depressed position so that the lateral stem orifices 20 are no longer sealed by gasket 21 . The stem 15 is locked into its precise depressed position by slides 47 and 48 locked into stem indent 60 , which depressed position is sufficient to unseal stem orifices 20 but not so great as to sealingly engage stem and housing frusto-conical surfaces 34 and 35 .
[0028] To now carry out product filling into bag 17 , product is filled through conduit 43 , stem dispensing conduit 19 , stem lateral orifices 20 , interior space 18 of valve housing 16 , down through valve housing extension 16 a , and into bag 17 . When the product filling is completed, the product filing head 40 is removed. The precise positioning of the valve stem 15 permitted by radial slides 47 , 48 and stem indent 60 not only prevents the stem 15 from being further depressed to seal surfaces 34 , 35 and prevent product filling down into the bag, but also prevents the stem 15 from rising up due to filling back pressure to seal lateral orifices 20 and prevent product from entering the valve housing 16 during product filling.
[0029] In a third aspect of the present invention, it will be seen from the description above that a bag-on-valve system, with a bag already in the can and the valve fixed to the container, can therefore be top pressure filled with both propellant and product in either order. By controlling the degree of stem depression and stem sealing during the respective filing operations, and by providing first and second predetermined depressed stem positions during said operations, propellant only is filled to the can space outside the bag and product only is filled into the bag. A simple, fast and efficient filling system using conventional pressure filling equipment thereby results.
[0030] It will be appreciated by persons skilled in the act that variations and/or modifications may be made to the present invention without departing from the spirit and scope of the invention. The present embodiments are, therefore, to be considered as illustrative and not restrictive. Purely as an example, a dip tube may extend from the valve housing down into the product bag to prevent the bag “pocketing” during dispensing. It should also be understood that positional terms as used in the specification are used and intended in relation to the normal positioning shown in the drawings, and are not otherwise intended to be restrictive.
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A bag-on-valve aerosol valve system in a container is provided. Propellant is pressure filled around the valve stem, outwardly over the stem gasket and down into the container space outside the bag. Product is filled through the valve stem into the bag. The valve stem has an exterior intermediate frusto-conical annular surface and the valve housing has an interior frusto-conical annular surface, with both surfaces engaging in annular sealing contact to block propellant access to the bag when the valve stem is deeply depressed to a first predetermined position for propellant pressure filling. A stem exterior surface indent interacts with radially-biased spring-loaded slides to lock the stem in a second less depressed predetermined position for product filling through the stem down into the bag.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to structural building decks having drainage systems associated therewith.
[0003] 2. Description of Related Art
[0004] Rooftop decks or sun decks are commonly found on buildings, such as residential structures, and generally provide an attractive gathering place with elevated views and sun exposure. However, often such decks can be difficult to maintain due to potential leaking through the deck into a space beneath the deck, such as, for example, when there are indoor living quarters situated beneath the deck. Some conventional methods of addressing deck leaks include coating the decks with waterproofing substances, including coating seams between deck floor planks. Such coatings can detract from the natural or attractive appearance of a deck having visible floor planks. Also, such coatings can require reapplication due to wear.
BRIEF SUMMARY OF THE INVENTION
[0005] Some embodiments of the present invention include deck drainage assemblies, systems, structures and methods of constructing the same. A rooftop deck having a drainage system can comprise a deck frame having floor joists. A plurality of planks can be coupled to the floor joists of the deck to form a floor of the deck and the planks may be visible, such as for aesthetic purposes. Flexible membrane sheets are coupled to the floor joists beneath the floor planks to form drainage channels having curved surfaces between the floor joists and beneath the floor planks. The flexible membranes sheets can comprise substantially water impermeable membranes such as, for example, modified bitumen. The drainage channels can have end portions adjacent a trough (gutter) and the trough can be enclosed within a frame of the roof deck. Also, apertures can be provided on one or more planks of the roof deck with the apertures being sealable using removable plugs. The plugs can be removable to allow insertion of a nozzle to flush or pressure wash the drainage channels beneath the floor of the deck. Also, straps of flexible material, such as nylon straps, can be coupled to the floor joists and extended between the floor joists beneath the drainage channels to provide support for the drainage channels.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0006] FIG. 1 is a perspective view of a deck comprising an embodiment of the present invention, with the deck disposed atop a building structure.
[0007] FIG. 2 is a partial cutaway perspective view of the embodiment of the present invention of FIG. 1 , showing drainage channels below floor planks of the roof deck and flexible straps for supporting the drainage channels.
[0008] FIG. 3 is a detail front elevation view of drainage channels and cross members of the deck as viewed from line 3 - 3 in FIG. 4 (but not showing the trough), with the drainage channels illustrated in partially assembled form comprising roofing felt sheets disposed below modified bitumen sheets that form the drainage channels.
[0009] FIG. 4 is a partial cutaway perspective view of the drainage channels of FIG. 2 .
[0010] FIG. 5 is a partial perspective cutaway view of the deck of FIG. 1 , illustrating the trough within an enclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, upon reviewing this disclosure one skilled in the art will understand that the invention may be practiced without many of these details. In other instances, well-known structures associated with decks and building construction have not been described in detail to avoid unnecessarily obscuring the descriptions of the embodiments of the invention.
[0012] Although various embodiments of the present invention are described and illustrated in the context of application to rooftop or sun decks, one skilled in the art will understand after reviewing the present disclosure that the present invention has applicability in a wide variety of structures to reduce or eliminate water leakage, such as, without limitation, building roof structures and other decks, whether disposed on a rooftop or not.
[0013] FIGS. 1-5 illustrate some embodiments of the present invention as applied to rooftop decks. Referring to FIG. 1 , in those embodiments, a deck 1 can be constructed atop a building structure 22 with the deck having visible floor planks 2 . The floor planks 2 can comprise conventional deck building materials, such as wood, or commonly available composite deck building materials.
[0014] As shown in FIG. 2 , a frame for the deck can comprise floor joists 10 , and cross-members 12 , which can have ventilation apertures 14 . The cross members can be “bird blocks,” as will be appreciated by those skilled in the art after reviewing this disclosure. In addition, flexible straps 9 of material, such as nylon straps, can be coupled to the floor joists 10 and extend between the floor joists.
[0015] The cross members 12 can have recessed or downwardly curved surfaces on top portions thereof. The flexible straps 9 can hang or droop downward between the floor joists 10 . As can be seen in the embodiment illustrated in FIG. 4 , flexible membrane sheets 18 can be disposed over the flexible straps 9 and the cross members 12 , with portions of the flexible membrane sheets 18 hanging downward between the floor joists 10 to form curved conduit walls or drainage channels 17 . The sheets of flexible membrane 18 can comprise water impermeable membrane, such as, for example, modified bitumen. The floor joists 10 can be constructed to provide a slight slope that is not noticeable to a user of the deck, but is enough to gravity drain water in the direction of arrows “A” within the channels 17 . Thus, water can leak through seams between the floor planks 2 , into the drainage channels 17 below to be directed away from the building structure 22 .
[0016] As can be seen in FIG. 3 , each channel 17 in which water can be drained, can be provided using a separate sheet of flexible membrane 18 , with side portions 18 b of each sheet of flexible membrane overlapping. In addition, a secondary sheet 16 , such as roofing felt, can be placed beneath each sheet of flexible membrane 18 , as will be appreciated by those skilled in the art after reviewing this disclosure. The roofing felt 16 can be used where a torch down method is employed for applying the flexible membrane 18 to seal the overlapping side portions 18 b of the flexible member sheets 18 . Furthermore, in some embodiments, various available sealant materials, such as tar sealants, can be applied between the layers of the sheets of flexible membrane 18 at the overlapping side portions 18 b to bind the sheets together and help seal against water leakage. However, again, in some embodiments where the flexible membrane sheets 18 comprise modified bitumen, the flexible membrane sheets 18 can be heated with a torch to seal the side portions 18 b , as will be appreciated by those skilled in the art. Referring now to FIG. 2 , the planks 2 can be attached to the floor joists 10 by, for example, providing nails that extend through the planks and the flexible membrane sheets 18 into the floor joists 10 .
[0017] In some embodiments of the present invention, a gutter or trough 20 is disposed near end potions 18 c of the channels 17 , as best seen in FIG. 4 . The end portions 18 c of the channels 17 can extend over the trough 20 . The trough 20 can channel water away from the end portions of the channels 17 , such as to a downspout 3 . Also, the trough 20 can be in an enclosure within a planks and sidewalls of the deck, as best seen in FIG. 5 . In some embodiments, the trough 20 can be removed by being slide outward away from the enclosure, through a side opening adjacent an end cap 7 of the trough 20 .
[0018] Furthermore, as illustrated in FIG. 5 , in some embodiments of the present invention, one or more of the planks 2 is provided with apertures 6 that extend through the floor planks, with the apertures 6 being capable of being sealed using threaded removable plugs (not shown). In some embodiments, the apertures 6 have diameters between about ½ inch and 3 inches. The removable plugs can be unscrewed to expose the apertures 6 so that a user can insert a nozzle of any of various commercially available flushing or pressure washing device (as will be appreciated by those skilled in the art after reviewing this disclosure) to pressure wash or flush the drainage channels 17 below the deck planks 2 .
[0019] Although specific embodiments and examples of the invention have been described supra for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the invention, as will be recognized by those skilled in the relevant art after reviewing the present disclosure. The various embodiments described can be combined to provide further embodiments. The described devices and methods can omit some elements or acts, can add other elements or acts, or can combine the elements or execute the acts in a different order than that illustrated, to achieve various advantages of the invention. These and other changes can be made to the invention in light of the above detailed description.
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A deck with a drainage system. The drainage system is comprised of drainage channels formed by a flexible membrane disposed beneath a floor of the deck.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/311,513, filed Aug. 9, 2001, which is hereby incorporated by reference.
[0002] This application is related to the pending application, application Ser. No. 09/943,044, filed Aug. 29, 2001, entitled “Enhancing Broadcasts with Synthetic Camera View”, which has been assigned to the common assignee of this application.
[0003] This application is also related to the pending application, application Ser. No. 09/942,806, entitled “Extracting a Depth Map From Known Camera and Model Tracking Data”, filed Aug. 29, 2001, which has been assigned to the common assignee of this application.
FIELD OF THE INVENTION
[0004] This invention relates generally to broadcasts of events and in particular to enhancing such broadcasts with synthetic scenes.
BACKGROUND OF THE INVENTION
[0005] As broadcast television becomes increasingly sophisticated by augmenting content based on supplemental data sources and camera tracking technology, there is a general desire to open up the possibilities for visual enhancements. Virtual set and movie special effects technology is leading to advanced camera tracking techniques that facilitate the integration of live video into synthetic environments by adapting the synthetic content to camera data (e.g. position, orientation, field of view). Thus the instrumentation of cameras for precise tracking is advancing.
[0006] Other technologies such as the new Zcam camera (Zcam is a trademark of 3DV Systems, Ltd.) is beginning to illustrate how depth information can become a first class data source for fusing synthetic content with video. Unfortunately Zcam and other methods of depth extraction (such as image disparity) are currently constrained to a limited volume for acquisition of depth information. The typical acquisition ranges of such technologies vary from a few square meters up to a volume commensurate to that of an indoor studio. The quality of depth reconstruction provided by such systems diminishes as it scales up. Thus these solutions do not scale up to levels where they can be applied to sports venues such as stadiums and racetracks. Modem sports entertainment programming features significant broadcast production enhancements. These enhancements affect both the audio and visual aspects of the coverage. Graphical displays-and audio samples and sound bites are routinely employed to enliven a broadcast's production. However these enhancements generally are not directed by the sports viewer at home.
[0007] Traditionally, sport viewers at home rely on the television broadcaster to, provide them with the best coverage available at any given moment. Functioning as a director, the broadcaster will switch from one camera feed to another depending on the events occurring on the field. With the emergence of DTV (digital television) broadcasting, the broadband viewers may have the opportunity to receive multiple camera feeds and be able to navigate amongst them. Still, the coverage of a sporting event is always limited by the fixed number of cameras set up for the event.
[0008] The home viewer is not currently able to choose on field activity on which they would like to focus if this activity is not included in the normal broadcast coverage. As there may be event activity occurring outside of the normal broadcast coverage (or that is made possible by multiple camera feeds), on which the home viewer places significant value, traditional broadcast coverage many times proves inadequate.
SUMMARY OF THE INVENTION
[0009] A broadcast of an event is enhanced with synthetic scenes generated from audio visual and supplemental data received in the broadcast. A synthetic scene is integrated into the broadcast in accordance with a depth map that contains depth information for the synthetic scene. The supplemental data may be sensing data from various sensors placed at the event, position and orientation data of particular objects at the event, or environmental data on conditions at the event. The supplemental data may also be camera tracking data from a camera that is used to generate a virtual camera and viewpoints for the synthetic scene.
[0010] The present invention describes systems, clients, servers, methods, and computer-readable media of varying scope. In addition to the aspects of the present invention described in this summary, further aspects of the invention will become apparent by reference to the drawings and by reading the detailed description that follows.
[0011] Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements.
[0013] [0013]FIG. 1 illustrates one embodiment of an exemplary system in accordance with the present invention.
[0014] [0014]FIG. 2 depicts a flowchart illustrating an exemplary process for enhancing broadcasting of an event in accordance with the present invention.
[0015] [0015]FIG. 3 depicts an exemplary digital video signal processing system in accordance with the present invention.
[0016] [0016]FIG. 4 shows one embodiment of in-car footage provided in accordance with the present invention.
[0017] [0017]FIG. 5 illustrates a synthetic view selection provided in accordance with one embodiment of the present invention.
[0018] [0018]FIG. 6 illustrates a synthetic view selection provided in accordance with one embodiment of the present invention.
[0019] [0019]FIG. 7 illustrates a synthetic view selection provided in accordance with one embodiment of the present invention.
[0020] [0020]FIG. 8 illustrates an example of sensor placement provided in accordance with one embodiment of the present invention.
[0021] [0021]FIG. 9 is a simplified block diagram of one embodiment of the system of the present invention.
[0022] [0022]FIG. 10 shows a simplified diagram of one embodiment of the system architecture of the present invention.
[0023] [0023]FIGS. 11 a and 11 b illustrate embodiments of processes of the present invention.
[0024] [0024]FIG. 12 illustrates an exemplary embodiment of a process which may be used in conjunction with the present invention.
[0025] [0025]FIG. 13 illustrates an exemplary embodiment of a process which may be used in conjunction with the present invention.
[0026] [0026]FIG. 14 depicts an articulated model of a race car which may be provided using processes executed in accordance with an embodiment of the present invention.
[0027] [0027]FIG. 15 depicts yet an alternative embodiment of the present invention.
DETAILED DESCRIPTION
[0028] The following description and drawings are illustrative of the invention and are not to be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of the present invention. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the present invention
[0029] The present invention is described in the context of live sports broadcasts. However, the present invention is not to be limited as such and is applicable to any kind of broadcasted event, live and recorded.
[0030] A system according to the present invention provides for the enhancement of live broadcasting, such as sports broadcasting, with synthetic camera views. A simplified block diagram of one embodiment of an exemplary system is illustrated in FIG. 1. Referring to FIG. 1, the system includes global positioning system (GPS) receiver 130 , viewer control unit 140 , camera sensor units 120 , Audio Visual (A/V) data feed 150 , signal processing unit 110 , and monitor 160 .
[0031] Signal processing unit 110 receives data inputs from sensor unit 120 , A/V data feed 150 , GPS receiver 130 , and customer interface 140 . The signal processing unit 110 processes these live data streams, along with traditional audio/visual streams, to produce a synthetic camera view enhancement. The synthetic camera shots may be from any desired view positions and angles. The signal processing unit is able to process these various forms of data to present appropriate visual representations on demand. The signal processing unit 110 can be a variety of processing units, including a general purpose processing system. The processed signal on which these synthetic camera shots are based is then fed into the monitor 160 which may be a variety of types of displays including a television or computer system display, for display.
[0032] Sensor unit 120 provides sensor data from desired locations. These sensor units are placed in a manner that will facilitate the complimenting of live sport broadcasting with synthetic camera shots from any desired view position and angle. In one embodiment, the sensor data is fed to facilitate the generation of the synthetic views which may be, in one embodiment, realistic computer generated graphics images. The live data streams that are produced by these units are fed into signal processing unit 110 .
[0033] GPS receiver 130 generates position and orientation data. This data indicates where objects of interest and moving objects, such as particular players or cars, are in 3D space. The live position and orientation data produced by the GPS unit facilitates a greater range of production by providing position and orientation data of objects of interest. This data stream is fed into the signal-processing unit for integration with other live data streams.
[0034] Camera tracking unit 180 provides camera tracking data. This data facilitates the integration of live video with synthetic components. The specific data generated may vary according to the equipment used. All or some of the data may be used to integrate video with the synthetic components. The integration is achieved by adapting the synthetic content to the generated camera data. By coordinating or registering the 3D-position information in space with camera tracking information, it is possible to render a virtual version of a known 3D object in a live video broadcast.
[0035] The camera tracking equipment, well known in the art, typically uses encoders to read the current pan, tilt and twist of the camera, as well as the zoom level, i.e., the field of view. Furthermore, the position of the camera is tracked in order to reproduce a virtual camera that corresponds to the real camera. The data generated by the camera-tracking unit is fed into the signal-processing unit to be integrated with other live data streams.
[0036] In one embodiment an audio visual signal 150 transmitted from A/V data feed is generated by live broadcast camera feeds. The data content of this signal is determined by the broadcaster. This signal is transmitted to the signal-processing unit 110 for integration with the other live data streams.
[0037] Viewer 140 determines the live view positions and view angles that may be presented. In one embodiment, viewer input controls the processing of the additional data and determines desired synthetic camera view enhancements that may be presented. In one embodiment viewer control is accomplished using a synthetic camera view creating application as it pertains to the generation of desired view positions and view angles. This application module processes camera view creating instructions that control the integration of the supplemental data streams. In one embodiment, viewer control unit controls the fusing of live video and synthetic camera views. In one embodiment, these camera view enhancements may be viewer controlled or broadcaster controlled but can also have some viewers that aren't based on real cameras but follow a car or a participant.
[0038] Viewing monitor 160 presents the live images that are being viewed. These images are based on the signal processed by signal processing unit 110 . This signal is transmitted to the television monitor by means of a presentation engine, which resides in the television monitor or in a separate set top box unit, e.g., a game console or another device.
[0039] [0039]FIG. 3 depicts an exemplary digital video signal processing system 300 with which the present invention may be implemented. In one embodiment, the synthetic camera view enhancing techniques may be implemented based on a general processing architecture. Referring to FIG. 3, digital processing system 300 includes a bus 301 or other communications means for communicating information, and central processing unit (CPU) 302 coupled with bus 301 for processing information. CPU 302 includes a control unit 331 , an arithmetic logic unit (ALU) 332 , and several registers 333 . For example, registers 333 may include predicate registers, spill and fill registers, loading point registers, integer registers, general registers, and other like registers. CPU 302 can be used to implement the synthetic camera view enhancing instructions described herein. Furthermore, another processor 303 such as, for example, a coprocessor can be coupled to bus 301 for additional processing power and speed.
[0040] Digital video signal processing system 300 also includes a main memory 304 , which may be a Random Access Memory (RAM) or some other dynamic storage device, that is coupled to bus 301 . Main memory 304 may store information and instructions to be executed by CPU 302 . Main memory 304 may also store temporary variables or other intermediate information during execution of instructions by CPU 302 . Digital processing system 300 may also include a static memory 306 such as, for example, a Read Only Memory (ROM) and/or other static source device that is coupled to bus 301 for storing static information and instructions for CPU 302 . A mass storage device 307 , which may be a hard or floppy disk drive, can also be coupled to bus 301 for storing information and instructions.
[0041] Computer readable instructions may be provided to the processor to direct the processor to execute a series of synthetic camera view-creating instructions that correspond to the generation of a desired synthetic camera view or angle selected by the viewer. A display device, such as a television monitor, display the images based on the synthetic camera views created by the instructions executed by processor 302 . The displayed images correspond to the particular sequence of computer readable instructions that coincide with the synthetic view selections indicated by the viewer.
[0042] [0042]FIG. 2 depicts a flow chart illustrating an exemplary process 200 for enhancing live sports broadcasting with synthetic camera views. Referring to FIG. 2 at step 210 , supplemental live data streams are generated from various sources. In one embodiment, these live data streams are generated by the various sources, such as A/V data feed 150 , sensor unit 120 , GPS satellite 130 , and camera tracking unit 180 of FIG. 1.
[0043] At step 220 the live data streams are transmitted to the signal processor. The data received may be used to create synthetic images that are chosen by the viewer. For example, if the sport viewed is car racing, the live video may show a camera view from the driver of one of the cars. A variety of virtual views may be generated; for example, a synthetic or computer generated image of a rear view mirror. One way the car on the track may be generated using the GPS data to determine location and orientation of the car, environmental conditions; e.g., smoke, rain, using the sensor data, and camera tracking data, which enables the computer generated image to be synchronized with the line video such that the computer generated image can be placed within the “rear view mirror” of the car.
[0044] At step 230 , the supplemental live data streams received in step 220 are processed. In one embodiment, the processing of the transmitted live data is facilitated by a program application in the signal processing unit. The execution of the program may be controlled by the viewer. The viewer directs the system to execute a series of synthetic camera view creating instructions to generate desired synthetic camera views selected by the viewer. In one embodiment a menu may be used; alternately, panning or zooming or positioning a camera in a realistic implementation may be done.
[0045] At step 240 , a synthetic video signal is generated. This synthetic video signal is based on data components taken from both the normal audio/visual data stream and the supplemented data streams. The synthetic camera views based on this signal are chosen by the broadcast viewer.
[0046] The supplemented video signal is then presented to the system presentation engine. This presentation engine may reside in the set receiver or set top box or game console. It can generate the desired synthetic camera view enhancement based on the live supplemental data it received.
[0047] At step 280 the television monitor displays the live synthetic camera views that were selected by the broadcast viewer. These camera shots may have been selected from any desired view position or view angle of the on field activities. The capacity to select such views and angles serves to enhance the viewer's awareness of on field actions that are not covered by the live broadcast video feeds.
[0048] At step 260 , the viewer selects a desired synthetic camera view. This selection determines whether or not the monitor displays images based on the unsupplemented audio/visual signal, or images based on the supplemented video signal.
[0049] If the viewer indicates a desire to view a scene not covered in the normal unsupplemented broadcast, then the video signal is processed as described in steps 230 and 240 . If the viewer does not desire to select a synthetic camera view, then the unsupplemented normal broadcast signal is presented to the television presentation engine and the normal unsupplemented unenhanced television broadcast is displayed on the television monitor (see step 270 ).
[0050] [0050]FIG. 4 shows an example of one embodiment of the present invention. Referring to FIG. 4, in motor sports, in-car footage is often shown during broadcast. However, this camera view only provides actions that occur in front of the car. With a synthetic rear-view camera shot mapped into a virtual rear-view mirror 410 or metaphor of the live video footage, viewers can also visualize actions occurring behind the car of interest.
[0051] [0051]FIG. 5 shows another example of one embodiment of the present invention. Referring to FIG. 5, some telecast sports are showing actions seen from the perspective of players or umpires on the field. However, it is usually not possible for the viewers at home to receive all the A/V streams from all players. Thus, viewers are not able to freely choose the inplayer camera view from the player of their choice. The process, according to one embodiment of the present invention, can generate synthetic camera views from any position and angle. In this way, inplayer views from any player can be produced. In FIG. 5, inplayer views may be produced from the perspective of any of the player shown.
[0052] [0052]FIG. 6 shows another example of one embodiment of the present invention. Referring to FIG. 6, similar to the inplayer view, one can create synthetic camera views from the viewpoint of a baseball, football, etc. The views obtained by such camera shots give viewers a new perspective when watching a sporting event.
[0053] [0053]FIG. 7 shows one embodiment of the present invention. In motor sport, a motor sport fanatic might want to follow his favorite driver throughout the race. However, most likely this driver will not be covered by the live broadcast for the entire race duration. Upon a viewer's request, the system according to one embodiment of the present invention may display a synthetic camera rendering that focus on a desired driver at all times.
[0054] The solution requires sensor data to be broadcast along with the traditional A/V streams. At a minimum, the sensor data should contain the position data for the critical elements (e.g. players, cars) in the sporting events. To achieve more realistic synthetic camera shots, a higher degree of sensor data tracking the orientation of the car, the movement of player's arms and legs and environmental conditions are needed.
[0055] [0055]FIG. 8 shows an example of sensor placement. In FIG. 8, a football player 810 is shown in a typical football stance. Sensors 820 through 828 are placed at strategic points on the player's body. The sensors placed on the player's arms and legs provide a high degree of sensor data. This sensor data facilitates the achievement of more realistic synthetic camera shots such as the movement of the player's arms and legs.
[0056] As discussed above the following description, for purposes of explanation, numerous details are set forth in order to provide an understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the present invention. The invention is described in the context of integrating a synthetically generated object, for example, a race car or football player, into a live video environment, for example, a car race or football game. It is readily apparent that the present invention is not limited to live video as the invention is readily applicable to any imaging media and media signals. Furthermore, the present invention is applicable to a wide variety of venues including sporting events.
[0057] Another embodiment of the system is illustrated by the simplified block diagram of FIG. 9. A first camera 910 is used to supply camera data for the virtual camera 930 , for example, information to define a viewpoint for the synthetic scene. The field of view of the camera 910 is also used to define the field of view for the virtual camera 930 . A tracked object's position, for example, the position of a race car of interest, is determined by object position device 920 . In one embodiment, the position is determined using a Global Positioning System (GPS) receiver. Other position determining devices may also be used. The position of the tracked object is used to position a model, for example, a computer generated model 940 and from this information a depth map 950 can be generated.
[0058] The system and method of the present invention provides for the extracting of a depth map from camera and model tracking data. Embodiments of the system and method of the present invention further provide for rendering a model in a live image environment using the depth map. A simplified block diagram of one embodiment of an exemplary system is illustrated in FIG. 10. Referring to FIG. 10, the system includes, global positioning system (GPS) receiver 1020 , camera tracking unit 1035 , sensor unit 1015 , video signal unit 1025 , signal processing unit 1010 and television monitor 1030 .
[0059] Signal processing unit 1010 receives data inputs from sensor units 1020 , video signal unit 1025 , GPS receiver 1020 , and camera tracking unit 1035 . More particularly, the signal processing unit 1010 receives sensor data from sensor units 1020 , position and orientation data from GPS receiver 1020 , video data from video signal unit 1025 and camera data from camera tracking unit 1035 . As discussed below, the signal processing unit 1010 processes these live data streams, to produce at least one synthetic camera view.
[0060] The synthetic camera views utilize depth maps 1040 , which, in one embodiment, have been extracted using the camera data and model data. The processed video signal from which these synthetic camera views are based may then be fed into a monitor, such as a computer monitor or television monitor 1030 for display.
[0061] Sensor unit 1015 provides sensor data from desired view positions and angles. These sensor units are placed in a manner that will facilitate the complimenting of live sports broadcasting with synthetic camera shots from any desired view position and view angle. In one embodiment, the sensor data is used to facilitate the generation of the synthetic views which may be, in one embodiment, realistic computer generated graphics images. Examples of sensor data include position of limbs of a player, weather and/or lighting conditions, and the like.
[0062] GPS receiver 1020 generates position and orientation data for each object haying a co-located GPS receiver 1020 . This data indicates where particular objects, such as players or cars, having a co-located receiver, are in space by providing position and orientation data of objects of interest.
[0063] Camera tracking unit 1035 provides camera-tracking data. This data facilitates the integration of synthetic environments into video by using camera data to adapt the synthetic content to the camera data reflective of the video environment. By registering position information, for example, 3D-position information, of the synthetic environments in space with the camera data, it is possible to render a virtual version of a known object. The camera tracking equipment that provides the camera data is known in the art and typically uses encoders to read the current pan, tilt, and twist of the camera, as well as, the zoom level, i.e., the field of view. Furthermore, the position of the camera is tracked, for example, by a GPS unit. As explained below, the camera data is used to reproduce a virtual camera that corresponds to the real camera.
[0064] The audio-visual signal from video signal unit 1025 is generated by the live broadcast. The data content is determined by the broadcaster. This signal is transmitted to the signal-processing unit 1010 for integration with the other live data streams mentioned earlier.
[0065] By registering the position information in space of an object with camera data, it is possible to render a virtual version of a known object (e.g., a race car) properly placed, scaled and oriented in front of a video scene, thereby integrating synthetic content with video content.
[0066] The processes described herein may be implemented as computer readable instructions which are provided to a processor such as the processing system 300 . These instructions are stored on and transferred over a computer readable medium and direct the processor to implement a series of commands that correspond to the processes herein described.
[0067] In one embodiment of the present invention, the position and orientation information used in conjunction with camera tracking data produces a virtual object. This virtual object is rendered to a depth map. The depth map captures the relative distance of the virtual objects from the view of a particular camera. In one embodiment of the system of the present invention, it is derived by reconstructing a virtual view with known 3D models and position and camera tracking data. Camera tracking data provides enough data to precisely emulate the real camera view in a virtual rendering.
[0068] One embodiment of the process is illustrated by the simplified flow diagram of FIG. 11 a. At step 1105 a virtual camera is established. In one embodiment, camera data from a camera filming (referred to herein as a live camera), for example a camera filming an auto race, consisting typically of position and orientation information, is used to establish the position, orientation etc. of the virtual camera. Thus the live camera data defines a viewpoint for the camera in the synthetic scene. In one embodiment, the motion of the camera may then be used to drive the motion of the virtual camera.
[0069] At step 1110 , the field of view of the virtual camera is set to that of the live camera and at step 1115 the synthetic model is positioned. In one embodiment, the model is a three dimensional graphic generated representation of an object, such as racing car, using the example discussed herein. The model is positioned in the synthetic environment in accordance with the virtual camera. At step 1120 , the depth map can be extracted from the synthetic environment and used for a variety of purposes, including combining the synthetically generated object(s) with the live imaging (i.e., video).
[0070] [0070]FIG. 11 b illustrates an exemplary process of one embodiment of the present invention. Referring to FIG. 11 b, at step 1155 the virtual camera is positioned at the coordinates/orientation of the tracked camera. This information imparts to the virtual view an orientation that is analogous to that of the view generated by the tracked camera. The virtual camera coordinates/orientation thus obtained are used to assess the objects from the view of the virtual camera.
[0071] At step 1160 , the field of view of the virtual camera is set to the field of view of the tracked camera. This step gives the virtual camera a field of view analogous to that of the tracked camera.
[0072] At step 1165 , the position and orientation of the virtual model is positioned to the coordinates and orientation of the tracked object. This step gives the virtual model a position and orientation analogous to that of the tracked object.
[0073] At step 1170 the depth buffer is cleared. This frees the depth buffer so that the model of the tracked object may be loaded into the buffer. In one embodiment, the depth buffer is cleared for each frame of live video subsequently combined with the synthetically generated data.
[0074] In step 1175 the model of the tracked object is rendered to the depth buffer. This model is rendered to the depth buffer as a depth map. The reconstructed data upon which this depth map is based allows the capturing of the relative distances of objects from the view of a particular camera.
[0075] At step 1180 the data in the depth buffer is distorted. In one embodiment, this is accomplished by copying the contents of the depth buffer to a texture on a grid, distorting the grid coordinates, and rendering the grid to generate the depth buffer. The depth buffer is then distorted using the radial distortion coefficient/optical center shift of the tracked camera, thereby completing the process.
[0076] Since the images generated are a virtual reconstruction, the resolution of the images are arbitrary and not constrained by video resolution, but in practice, since it is ultimately fused with video data, it will typically be processed at video resolution. The depth map can be used to compute occlusion with a graphic system using techniques known in the art, but in large-scale venues. Computing the depth information can be done in real time, as it is simpler than traditional rendering, because lighting and other visual enhancements are not required to produce a depth map.
[0077] For example, processes executed in accordance with one embodiment of the invention may be used to create a depth map for an auto racing broadcast. The depth map generated can facilitate the insertion of graphics objects into video images with proper occlusion so that the inserted graphics seamlessly integrate in with the video images displayed in the racing broadcast. For instance, to show a viewer controlled virtual car racing against the live racers on a networked home game console or in a sports bar. The viewer would be able to observe their performance as if they were in the live race. An example of one embodiment is explained below in the context of an auto racing broadcast that is enhanced by the integration of virtual car images using the process.
[0078] The virtual camera is positioned at coordinates/orientation of a tracked camera. Some cameras on the market today are instrumented to enable real-time tracking of their position and orientation. This camera data can serve as a feed for data packets to the device that is doing the graphics generation of synthetic environments. The device doing the graphics generation begins with a geographically registered 3D model of the same track (“virtual track”) where the race is taking place. The live camera data defines a viewpoint for the camera in the synthetic scene. This enables the motion of the camera at the race to drive the motion of the camera that is used to render the virtual track.
[0079] The field of view is set to that of the tracked camera. Among other camera parameters in the data packet, the virtual camera replicates the field of view so that the viewing frustum for the virtual scene maps precisely to that of the live camera. This enables the edges of the rendered scene to correspond to the edges of the video from the tracked camera.
[0080] The position/orientation of the model of the tracked object is positioned/oriented to coordinates/orientation of the tracked object. For example, using GPS (Global Positioning System) sensors on each car in the race, a 3D model of the associated car is placed in the scene and animated based on the derived sensor data. The derived sensor data is transmitted in data packet form. Orientation may also be based on the track model if the GPS data doesn't provide sufficient data using the geometric normal of the part of the track model where the car is located. This may be accomplished because the track model has a fixed inclination. Additionally, steering wheel data may be used to properly orient the tires to the rest of the car because the tires rotate based on steering.
[0081] Ultimately the virtual scene is rendered into a depth buffer that will have a numeric value for every pixel reflecting normalized depth information relative to the camera being used to render the scene (that being tracked). In one embodiment, to support dynamic depth tracking, the depth buffer is initialized as empty for each frame that is rendered.
[0082] The model of tracked object is rendered as a depth map into depth buffer. The synthetic content (car model and track model) may be rendered into a depth map that rather than being a visually accurate image of the track is just the normalized depth value for each pixel of the image. This may be used as an auxiliary data source for subsequent composting of video graphics content. Alternatively, only the tracked objects may be rendered, but there are situations where it might be appropriate to occlude all or part of a car based on fixed objects (e.g., going under a sign or bridge). In such situations the occluding features (e.g., signs, bridges) that are rendered into the depth map with the tracked objects (vs. the track and other rigid features in the 3D model).
[0083] The depth buffer may be distorted (e.g., conceptually copy to a texture on a grid, distort grid coordinates, render grid) using radial distortion coefficient/optical center shift of the tracked camera. A final step in refining the depth buffer is distorting the image to adjust to some of the characteristics of the tracked camera to compensate for real distortion. In one embodiment, this is basically an image warp similar to a pincushion pattern. In alternative embodiments either the depth map or the video image, may be distorted depending on subsequent usage needs. As long as the models and data are highly accurate, there should be very accurate pixel coverage and it would be possible to overlay the graphics directly on the video and have them registered. The normalized depth data has a mapping to 3D space so that it can be properly registered with the video and only the parts of graphics objects that should not be occluded by objects in the video will be overlaid in the final composition. This happens by associating the depth map and the video imagery together, then inserting any additional features using the depth information to determine which parts are visible.
[0084] In practice, there may be artifacts based on the precision of the data or of the models used in the rendering. One potential solution for removing the artifacts to make the integration of synthetic and video content more seamless would be to combine data from the depth map with a video processing routine that does real time image segmentation.
[0085] In one embodiment of the present invention, the process involves duplicating the distortion introduced by the video camera's optics. Camera tracking data which supports this system functionality includes pan/tilt/roll, nodal point position (in 3D space), field of view, optical center (in the image plane), and radial distortion coefficient.
[0086] [0086]FIG. 12 shows one embodiment of a process that may be used in conjunction with the present invention. Referring to FIG. 12, at step 1210 the edges in the depth map are found, for example, by using a LaPlacian filter or by rendering the silhouettes of the models into a third destination.
[0087] At step 1220 , the edges found in step 1210 are used as initial conditions for a search in the video image data for edges, because the interest is only in the segmentations that are near these edges. When processing the video data as illustrated in steps 1210 and 1220 , a variety of edge detection processes will work.
[0088] [0088]FIG. 13 shows an exemplary process to be used in conjunction with the present invention. Referring to FIG. 13, at step 510 , a low-pass filter is used. Such a filter is utilized since the interest is not in high-frequency changes. It is the appropriate filter type because the search is for larger objects. It is readily apparent that other types of filters may also be used.
[0089] At step 520 , a LaPlacian operation is used to find edges. This is accomplished by only calculating in the vicinity of edges known to be in the depth map. It is readily apparent that other processes may be used to identify edges.
[0090] At step 530 , found edges are correlated with the edges of the depth map. By correlating the depth map appropriately, there should be produced a much more useful depth image.
[0091] [0091]FIG. 14 depicts an articulated model of a race car which may be provided using processes executed in accordance with an embodiment of the present invention. Referring to FIG. 14 there is shown a racecar 600 , including steering wheel 610 , and tires 620 . By using additional tracking data, variations in this articulated model of the racing car may be computed. For instance, if this approach were applied to such a car during a car race, the depth map computed from a rigid model of the car would be accurate if the model and camera data were precise. Because the wheels of the car, however, move relative to the car, an articulated car model is needed. In car racing, there is real time telemetry data available on steering. Consequently, the 3D model could be adjusted to properly orient the wheels based on the steering data to provide a more accurate model for rendering the depth map.
[0092] [0092]FIG. 15 illustrates an exemplary system for enhancing live sport broadcast according to one embodiment of the present invention. The system 1500 includes a live sport environment 1511 , a broadcast server 1501 which may be controlled by a broadcaster 1504 , a broadcast client 1502 communicating with the broadcast server 1501 over a network 1506 , a viewer control unit 1505 coupled to the broadcast client 1502 , and a display device 1503 to display the broadcast images. The live broadcast environment 1511 includes a live video camera 1508 to provide live audio visual (A/V) data, a GPS satellite 1507 to provide position and the orientation information of an interested object, such as racing car 1510 , and tracked cameras 1509 to provide tracked camera data.
[0093] Referring to FIG. 15, the broadcast server 1501 receives live A/V data from a live video camera 1508 and other supplemental data. In one embodiment, the supplemental data includes tracked camera data from multiple tracked cameras, such as cameras 1509 . The tracked camera data includes the position of the camera tracked. In an alternative embodiment, the supplemental data includes position and orientation data of an interested object (e.g., racing car 1510 ) from a GPS satellite 1507 . In a further alternative embodiment, a plurality of sensors may be placed in strategic points of the racing car 1510 , such as steering 610 or wheel 620 illustrated in FIG. 14 to enhance the realistic movement of the car in a 3D space. Other tracking or acquisition devices may be utilized.
[0094] The supplemental data collected from the GPS satellite 1507 , tracked cameras 1509 , live video camera 1508 , and sensing data from a plurality of sensors placed in the car 1510 , is received at the broadcast server 1501 . In one embodiment, a broadcaster may further edit the data. Alternatively, the supplemental data may be encoded in a transported package. In one embodiment, the supplemental data may be encoded in a format compatible with motion picture expert group (MPEG), such as MPEG2. The supplemental data is then transmitted to the broadcast client 1502 over a network. In one embodiment, the network may be an Internet. Alternatively, the network may be a cable, satellite, or terrestrial broadcast network. The supplemental data may be decode to retrieve original supplemental data.
[0095] The broadcast client then may generate a synthetic scene, or synthetic camera view based on the supplemental data received above. In one embodiment, a user may select a specific view to be constructed through the viewer control unit 1505 . During the processing of the data, a depth map for storing the depth information of the synthetic view may be construed using a method discussed above. Then the synthetic scene specified by a user may be combined with the live broadcast video, using the depth map. The combined video is then displayed at the display device 1503 .
[0096] It will be appreciated that that more or fewer processes may be incorporated into the methods illustrated in FIGS. 11 A-B, 12 and 13 without departing from the scope of the invention and that no particular order is implied by the arrangement of blocks shown and described herein. It further will be appreciated that the processes described in conjunction with FIGS. 11 A-B, 12 and 13 may be embodied in machine-executable instructions, e.g. software. The instructions can be used to cause a general-purpose or special-purpose processor that is programmed with the instructions to perform the operations described. Alternatively, the operations might be performed by specific hardware components that contain hardwired logic for performing the operations, or by any combination of programmed computer components and custom hardware components. The methods may be provided as a computer program product that may include a machine-readable medium having stored thereon instructions which may be used to program a computer (or other electronic devices) to perform the methods. For the purposes of this specification, the terms “machine-readable medium” shall be taken to include any medium that is capable of storing or encoding a sequence of instructions for execution by the machine and that cause the machine to perform any one of the methodologies of the present invention. The term “machine-readable medium” shall accordingly be taken to included, but not be limited to, solid-state memories, optical and magnetic disks, and carrier wave signals. Furthermore, it is common in the art to speak of software, in one form or another (e.g., program, procedure, process, application, module, logic . . . ), as taking an action or causing a result. Such expressions are merely a shorthand way of saying that execution of the software by a computer causes the processor of the computer to perform an action or a produce a result.
[0097] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
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A broadcast of an event is enhanced with synthetic scenes generated from audio visual and supplemental data received in the broadcast. A synthetic scene is integrated into the broadcast in accordance with a depth map that contains depth information for the synthetic scene. The supplemental data may be sensing data from various sensors placed at the event, position and orientation data of particular objects at the event, or environmental data on conditions at the event. The supplemental data may also be camera tracking data from a camera that is used to generate a virtual camera and viewpoints for the synthetic scene.
The present invention describes systems, clients, servers, methods, and computer-readable media of varying scope. In addition to the aspects of the present invention described in this summary, further aspects of the invention will become apparent by reference to the drawings and by reading the detailed description that follows.
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BACKGROUND OF THE INVENTION
In many areas of foodstuffs technology, it is desirable for certain amounts of foodstuffs to be prepared in portions which are as accurate as possible.
While the portioning of liquid or free-flowing materials takes place without problems or substantially without problems, the portioning of foodstuffs which do not flow has to be considered to be something other than optimum.
For example, during the production and further processing of meat products, it would be desirable if, for example, beef, pork or turkey meat could be cut and prepared in portions which are as identical as possible. Correspondingly equally sized portions of meat could then be processed further or sold optimally.
Corresponding calibrating devices have also been disclosed, for example, for shaped and processed meat, in which the meat is initially processed and pressed together again in such a manner that it assumes a certain shape. However, for the time being this requires the stringy meat to be processed into very small pieces or involves utilizing meat residues.
A calibrated cutting installation having a shaping tube for feeding the meat to a cutting device in order to separate meat into portions which are as far as possible of equal size by means of a cutter has already been disclosed. The shaping tube can be separated into two parts in the longitudinal direction. The end of the shaping tube, at a so-called delivery hole, is adjoined by a pot-shaped or shell-shaped depressions, the size and volume of which predetermine the corresponding portion. Then, a cutter can be moved through a in a spacer gap between the feed hole of the shaping tube and the abovementioned calibrated shaping cavity, the oblique arrangement of the cutting edges of which cutter causes a pulling cut, with the result that the corresponding amount of meat situated in the calibrated shaping cavity can be separated from the large remaining amount of meat situated in the shaping tube.
Then, the pot-shaped calibrating plate can be moved in order, if appropriate by means of further auxiliary measures, to remove the amount of meat which is situated in the calibrating cavity from the calibrating cavity and, for example, to deliver it to a conveyor belt.
However, the calibrated cutting device just mentioned has a number of drawbacks.
It has emerged that it is not always possible to ensure that the calibrating cavity is filled as uniformly as possible with the known calibrated cutting device. This is despite the fact that the calibrating cavity is designed more in the shape of a soup-dish, i.e. has a concave curve at the transition from the base area to the side wall area, avoiding a sharp edge, so that, as far as possible, inclusions of air are prevented. In addition, vacuum suction lines emerge from the area of the base of the calibrating cavity, in order to use a further suction device to pull in each case the next portion of meat optimally into the calibrating cavity. However, in this case too it has been found that the meat which is to be processed partially closes the suction passages which are present, so that air bubbles which are situated at a different location between the meat portion and the calibrating cavity cannot be sucked out. Ultimately, this leads to the size and weight of the meat portions which are to be separated differing considerably, at least in relative terms.
In view of the above, working on the basis of the abovementioned prior art, the object of the invention is to provide an improved calibrated cutting device which can be used to portion foodstuffs that are suitable for cutting, in particular meat, as optimally as possible, with the minimum possible weight and/or volume discrepancies.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below with reference to an exemplary embodiment, in which, in detail:
FIG. 1 : shows a diagrammatic, longitudinal side view through a vertical, central longitudinal section through the calibrated cutting device;
FIG. 2 : shows a diagrammatic, horizontal plan view at the level of the cutter, with a shaping tube having been omitted; and
FIG. 3 : shows an enlarged detailed view from FIG. 1 .
DESCRIPTION OF THE INVENTION
With the present invention, relatively simple means are used to achieve considerable improvements over the prior art.
Thus, it has emerged that the structure and the functioning of the vacuum for pulling the next meat portion into the calibrating cavity can be decisively improved by the fact that a connection which is as far as possible vacuum-tight can be produced between the delivery hole of the shaping tube and the adjoining feed hole of the calibrating cavity. As a result, the feed movement of the meat situated in the shaping cavity is supported by the sucking action of the vacuum for which reason the importance of a press ram which can additionally be moved in the advancement direction from the rear side in the shaping cavity is lowered and reduced. According to the invention, this is achieved by means of a pressure-exerting or clamping device which, at least during certain working cycles of the calibrated cutting device, at least indirectly presses the calibrated shaping cavity and the delivery hole in the shaping tube together, so that in this area the desired pressure reduction is maintained further and can continue to act in the shaping tube.
In a preferred embodiment of the invention, the cutter used is a perforated cutter, the size of perforations of which at least corresponds to the size and shape of the feed hole of the calibrating cavity. Then, during the cutting stroke, the perforated cutter is moved in the longitudinal direction between the output hole in the shaping plate and the support surface of the calibrating plate which accommodates in the calibrating cavity. Moreover, the use of the perforated cutter further assists with building up the abovementioned vacuum, since the perforated cutter is arranged with an encircling section of material between the output hole of the shaping tube and the feed hole of the calibrating plate which accommodates in the calibrating cavity.
The cutter is preferably of the same shape as the calibrating plate and may in this case be ground from solid tool steel. In the trailing area, that is to say in the cutting direction, it is preferably provided with two blades which are directed at an angle to one another. The thickness of the cutter can be selected to be extremely thin, preferably ranging between 0.5 mm and 3 mm.
However, the pressure between calibrating cavity and shaping cavity, preferably with the inclusion of the perforated cutter situated between them, is not only a prerequisite for a continuous, optimum vacuum to be applied, but also it prevents a smearing effect of the cutter, which represents a drawback. This is because, according to the invention, the clamping action means that an extremely thin cutter can be used, having the further advantage that in the area of the volume which corresponds to the thickness of the cutter material it is virtually impossible for any residual quantities of meat to remain, since the wedge effect of the cutter is only minimal, due to its small thickness.
The calibrated cutting device shown in the figures comprises a base 1 , which is also referred to below as a base frame.
A pressure-exerting plate 3 is fitted in the area of one end side of the base frame 1 , which is rectangular in plan view, which pressure-exerting plate has a cylindrical bore 5 which faces upward and in which a cylindrical mating piece 7 of a vacuum plate 9 engages.
By means of the cylindrical mating piece 7 , which engages in the cylindrical bore 5 , of the vacuum plate 9 , a pressure chamber 11 of a clamping unit 13 is created, the importance of which will be dealt with below.
By means of a compressed-air port 17 with a following pressure line 19 , compressed air can be fed in controlled amounts to the pressure chamber 11 of a compressed-air source (not shown in more detail).
The abovementioned vacuum plate 9 has a reduced-pressure chamber 21 which is in communication with a suction port 25 via a suction line 23 . A vacuum valve 27 , which is only indicated in FIG. 1, is also fitted in the suction line 23 .
An inlay plate 31 , which is offset at a higher level with respect to the base of the reduced-pressure chamber 21 by means of feet or spacers 33 , is inserted in the reduced-pressure chamber 21 . The top side 31 ′ of the inlay plate 31 is approximately flush with the surface 35 of the vacuum plate 9 or is arranged only—preferably only fractions of a millimeter—lower than the surface 35 of the vacuum plate 9 .
In plan view, the shape and dimensions of the inlay plate 31 are designed in such a way with respect to the dimensions and shape of the reduced-pressure chamber 21 , likewise in plan view, that only an extremely small gap is formed between the periphery edge 39 of the inlay plate 31 and the adjacent, encircling wall surface 43 of the reduced-pressure chamber 21 ; this gap may, for example, be between 0.05 and 2 mm, preferably between 0.1 and 1 mm, in particular between 0.2 and 0.6 mm. In the exemplary embodiment shown, a gap width of 0.3 mm is selected. In the exemplary embodiment shown, the gap height is 5 mm, corresponding to the thickness of the actual inlay plate 31 situated above the feet 33 . These small dimensions of the gap 37 ensure that it is impossible for any relatively large meat particles to be sucked out during the calibration and cutting operation (FIG. 3 ).
A calibrating plate 47 , which is shown in its basic position in FIGS. 1 to 3 and comprises a hollow or calibrated shaping cavity 49 which surrounds by the material of the calibrating plate 47 in plan view and is open at the top and bottom, rests on the surface 35 . The feed hole 51 , which faces upward, and the horizontal cross-sectional shape and dimensions of this shaping cavity correspond to the horizontal cross-sectional shape and dimensions of a shaping tube body 53 which is arranged above the calibrating plate 47 and has a shaping tube 55 , which is situated vertically in the interior and from the top, charging side 57 of which meat to be portioned can be supplied and pushed downward via a press ram 61 which is arranged above the charging hole 57 and can be actuated by means of a press cylinder 59 . In plan view, the shaping tube is oval in cross section, namely with an oval hole 55 ′, as can be seen in the plan view shown in FIG. 2 . Apart from the cutting edges 65 ′ which are aligned in the shape of a wedge, this oval shape 55 ′ also corresponds to the cross-sectional shape and size of the calibrated shaping cavity 49 . The shaping tube 55 or the shaping tube body 53 may be formed form a plurality of plates with corresponding recesses, which can be laid on top of one another, the shaping tube body 53 or the individual plates which form this body being held by two side guide columns 71 which are connected to the base 1 and are held securely above it. Alternatively, the shaping tube body may also be divided in two in its longitudinal axis, for example in the form of two half-shells.
Since the lower surface of the shaping tube body 53 serves as a sealing surface with respect to the cutter 65 , the lower bearing or sealing surface 66 of the shaping body 55 has to cover the V-shaped cutout 67 of the cutter 65 in the starting or filling position.
As can be seen from FIG. 1 and in particular from the enlarged, vertical cross-sectional view shown in FIG. 3, the shape and dimensions of the hole in the vacuum or reduced-pressure chamber 21 , which accommodates the inlay plate 31 , are slightly larger than the horizontal cross-sectional shape and dimensions of the hollow or calibrated shaping cavity 49 in the calibrating plate 47 and/or the horizontal cross-sectional shape or dimensions of the shaping tube 55 .
Finally, a cutter 65 , i.e. a perforated cutter 65 , is provided between the calibrating plate 47 , resting on the latter, and the underside of the shaping tube body 53 , which cutter is of approximately rectangular design in plan view, i.e. is in the shape of a plate, and comprises a cutting hole 67 (FIG. 2 ), which at least corresponds to the size and shape of the delivery hole 63 of the shaping tube 55 and/or the feed hole 51 of the calibrated shaping cavity 49 . In the exemplary embodiment shown, the cutting edges, in plan view, are of V-shaped design in the leading cutting direction (FIG. 2 ), the two cutting edges 65 ′, which are in a V shape with respect to one another, coming together in the central longitudinal axis of the rectangular perforated cutter 65 . The two cutting edges 65 ′ run, for example, at a 45° angle to the central longitudinal plane of the cutter, i.e. they include an angle of approximately 90° with one another, i.e. include an angle of approximately 90° with respect to one another and, in this way, produce a pulling cut. The inclination of the cutter may also vary to a correspondingly great extent, for example by at least up to +/−30° and more. Alternatively, it is also possible to provide exchangeable blades 65 ′ in a cutter body.
However, as an alternative to a cutting arrangement which can be moved to and fro, in principle a rotating cutting device is also conceivable. For example, it would be possible to use a disk-like cutting device which comprise closed cutting holes which are offset with respect to one another in sectors and the size and function of which correspond to the cutting hole described above; to carry out a cutting operation, a movement of the cutter along a circle or part of a circle with an axis of rotation which is outside the cutter hole would have to be executed. In this case, a continuous rotary movement of the cutting device, at least in steps, would be possible if all the cutting holes in the rotating perforated cutter have trailing cutting edges.
On that side of the base frame 1 which is opposite from the shaping tube body 53 , there may, in addition to control elements and devices, additionally be at least two cylinders 73 and 75 , namely a cutter cylinder 73 for moving the perforated cutter 65 forward and backward as illustrated by the arrow 77 and a calibrating cylinder 75 corresponding to the adjustment movements of the calibrating plate 47 , likewise in the direction of arrow 77 . For this purpose, the two calibrating cylinders 75 , 77 are fixedly connected to the cutter 65 and the calibrating plate 47 by means of clamping/holding elements 75 ′.
The cutter is preferably of the same shape as the calibrating plate and consists of and is ground from a solid tool steel. The thickness of the cutter may vary within suitable ranges, for example from 0.3 mm to 5 mm, preferably may vary from 0.5 mm to 1.0 mm. Like the calibrating plate (which will be dealt with in more detail below), the cutter also moves at a right angle to the vertically oriented shaping tube 55 .
The method of operation is dealt with below.
Since, as is customary, cleaning has been carried out according to the extent to which the overall device can be broken down, the device can then be reassembled and put into operation. A suction hose is connected to the suction port 25 , and a compressed-air hose is connected to the compressed-air port 17 , which hoses are connected to corresponding vacuum and compressed-air devices.
Furthermore, three further hose ports are provided. One hose port is required in order to restore the plunger of the vacuum valve, since when the cutter reaches its extended limit position following the cutting operation (or shortly before), a valve plunger of the valve arrangement 27 is turned and the vacuum supply to the reduced-pressure chamber is interrupted. Then, the calibrating plate is extended forward. The cylinder outlet air is additionally utilized in order to ventilate the vacuum chamber. In this way, the pressure reduction which is present in the vacuum chamber is eliminated more quickly. The elimination of the pressure reduction prevents a sucking action from the vacuum chamber still being present when the calibrating plate is pushed out. The further hose port mentioned above serves as an air port for the vacuum chamber in order for compressed air to be pumped in here. The final hose port serves as the pressure connection to the vacuum chamber, in order to accommodate a vacuum switch in this hose port so as to measure the pressure in the vacuum chamber.
To portion relatively large amounts of meat, a suitable piece of meat is passed through the charging hole 57 from above into the shaping tube 55 , the pressure reduction which has been generated by a vacuum device (not shown in more detail) and is active in the reduced-pressure chamber 21 pulling the piece of meat further into the shaping tube 55 . The advancement movement of the piece of meat is assisted by subsequent actuation of the press cylinder 59 .
As a result of the pressure reduction generated in the reduced-pressure chamber 21 and the advancement movement of the press ram 61 , the leading area of the piece of meat which is to be portioned is moved downward until the front part of the piece of meat which is to be portioned completely fills the hollow or calibrated shaping cavity 49 . However, due to the extremely small gaps 37 , it is impossible for any meat to penetrate into or be sucked out through the vacuum and suction gaps 37 .
The desired pressure reduction for assisting with the advancement movement of the meat to be portioned and the complete filling of the calibrated shaping cavity 49 by the meat is primarily assisted and ensured by the fact that the entire arrangement of shaping tube body 53 , perforated cutter 65 and the calibrating plate 47 situated beneath it is subjected to preliminary pressure and clamped together by the clamping device 13 with the pressure-exerting and vacuum plate (explained at the beginning) in the manner of an assembly so that as far as possible there can be no ambient pressure penetrating into the reduced-pressure area, causing a loss of the pressure reduction. Since, moreover, a perforated cutter is used, it is also impossible for any atmospheric pressure to pass into the reduced-pressure area in the region of the cutter. Moreover, due to the abovementioned guide columns 71 , the shaping tube body 53 is held securely and non-displaceably with respect to the base 1 , as a pressure-exerting abutment, in order that the clamping unit 13 formed in this way can be optimally pressed together accordingly.
As soon as a piece of meat to be portioned has filled the entire calibrated shaping cavity 49 , a vacuum switch 27 which is in communication with the reduced-pressure chamber 21 can be used to establish a change in the pressure reduction. Furthermore, the cutter cylinder 73 can then be triggered and actuated, this cylinder being extended in the cutting direction and, in the process, separating the amount of meat which is situated in the calibrated shaping cavity 49 from the amount of meat which is situated in the shaping tube body 53 . In the device described, the clamping device 13 is permanently exposed to pressure and clamped in place, providing the further advantage that it is possible to use an extremely thin cutting plate or cutting disk. The clamping device which is under pressure protects the thin metal sheet of the cutter from becoming deformed, and the cutter is also stabilized by the opposite wall sections of the underside 66 of the shaping tube body 53 or the top side of the calibrating plate 47 .
As soon as the cutter has reached its front limit position, i.e. at least when the cutting hole 67 has fully traversed the feed hole 51 in the calibrated shaping cavity 49 , the calibrating cylinder 75 and therefore the calibrating plate 47 are likewise made to advance. As soon as the calibrated shaping cavity 49 has moved beyond the vacuum plate, the meat can be passed, for example downward, to a delivery station, for example an outgoing conveyor belt, etc., either by its own weight or by means of an additional ejector device. A simple auxiliary device which ejects the portioned meat may, for example, comprise levers which press the meat downward out of the calibrating mold. The ejector device may also be a short, sufficiently strong air stream which can be generated, for example, by cylinder outlet air. Other ejector devices are also possible.
Then, for preference, firstly the calibrating plate and then the perforated cutter move back into their starting position shown in FIGS. 1 to 3 and the operation repeats itself, i.e. after the starting portion of the cutter 65 and the calibrating plate 47 has been reached, firstly the clamping device 13 is confirmed once again and a pressure reduction is built up in the vacuum chamber 21 , and through actuation of the press ram 61 the meat which is situated in the shaping tube is moved further in the direction of advancement, i.e. into the calibrated shaping cavity again, etc. As soon as the entire amount of meat has been portioned and the press ram 49 which has moved forward in the shaping tube 55 has reached its lowermost position (which is no lower than the level of the bottom surface of the underside of the mating pressure plate 66 of the shaping tube body 53 ), a complete cutting operation is then carried out once again, so that the press ram can then be retracted from the shaping tube.
If different types of meat are to be processed or types of meat are to be portioned with different sizes and weights, it is possible to use differently dimensioned cutting and calibrating plates with differently dimensioned and shaped calibrated shaping cavities. With the same perforated cutter and the same shaping tube, the calibrating plates then differ through a different thickness, in order to vary the weight and size of the amount of meat to be portioned. However, if the size of the amount of meat to be portioned is to be varied in side view, it would then also be necessary to fit a different perforated cutter with correspondingly different sizes of cutting holes and a shaping tube of different cross section.
The calibrated cutting device which has been explained can be used to produce meat portions of equal size which differ, for example, by only extremely small amounts of +/−5 grams and less, for example of +/−2 grams.
The entire control arrangement may be of different structure. For example, an electrical control unit, for example in the form of a PLC, a contactor control unit or a relay control unit or in the form of combinations may be suitable. A microprocessor-assisted control unit is also possible, in particular if the calibrated cutting-device is incorporated into a larger installation. In the actual embodiment shown, compressed-air control has been described. Without being described in detail, it is possible for magnetic switches to be provided on the cylinders, working valves and control valves, and the valves used may be OR, AND, 3/2-way or, for example, 5/2 valves. Pressure reducers, manometers and vacuum switches are also components which can be used for operation.
For example, in particular the vacuum valve 27 described may also be actuated by plunger actuation from the displaceable cutter holder and the restoring air.
A very wide range of variants are possible for the vacuum-generating means explained in connection with the operation of the device. By way of example, it is possible for a vacuum-generating means to be based on the Venturi principle in order to generate a pressure reduction. In this case, the vacuum-generating means can be switched on by the pneumatic control unit only for the phases when the calibrating cavity is to be refilled with meat. However, it may also be necessary for this unit to be activated at all times, so that a “vacuum cushion” builds up in the filters, until the plunger valve 27 opens again. Naturally, it is also possible to use a continuously running vacuum pump. Reduced pressure is only passed into the vacuum or reduced-pressure plate by the valve plunger 27 which has been explained when this reduced pressure is required. In the interim periods, a vacuum cushion can build up in the filters.
With the calibrated cutting device it is possible, for example, to realize a cutting cycle time of 1 second, meaning that one slice of meat can be portioned and ejected every second.
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The invention relates to a calibrated cutting device for slicing foodstuffs that are suitable for cutting, more particularly meat products. Said device has the following characteristics: a base frame ( 1 ) is provided; a shaping tube ( 55 ) is also provided, through which the food product that is to be sliced is moved forward in the direction of a calibrated cavity ( 49 ); the calibrated shaping cavity ( 49 ) is a separate constructive unit different from the shaping tube ( 49 ); a knife arrangement ( 65 ) moving lengthwise is provided between the feed hole ( 31 ) of the calibrated shaping cavity ( 49 ) and the adjacent delivery hole ( 63 ) of the shaping tube ( 55 ), which is arranged between the calibrated cavity ( 49 ) and the shaping tube ( 55 ); a clamping unit ( 13 ) is also provided. The shaping tube ( 55 ) and the calibrated shaping cavity ( 49 ) can be pressed together by means of the clamping device ( 13 ) in order to achieve a negative pressure on the shaping tube ( 55 ) through the calibrated shaping cavity ( 49 ).
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/951,760 filed Jul. 25, 2007, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to transport of lunar soil, and more particularly relates to an apparatus and method for transporting lunar soil containing nano-sized metallic iron particles.
BACKGROUND INFORMATION
[0003] NASA and the Apollo astronauts who walked on the Moon have stated that one of the foremost problems to be solved before we return to the Moon concerns lunar dust. This fine (e.g., less than 20 microns) portion of the lunar soil makes up about 20 wt % of the total soil and is extremely clinging, abrasive, toxic and omnipresent. Many activities on the Moon are negatively affected by this dust. During the Apollo missions, it caused reduced movement in the joints of the astronauts' space suits and wore through layers of the Kevlar cloth of the suits. Its clinging nature caused the initially white suits to become dirty, thereby absorbing more black-body heat with each Moon walk. In the lunar module when the astronauts removed their helmets, they experienced distressing sensations from the dust in their eyes, noses, and throats. Equipment having moving parts and friction bearing surfaces exposed to the lunar dust may also be negatively affected. For example, it was found that boxes used to collect and return lunar samples to Earth were not tightly sealed due to the presence of lunar dust. In fact, all Apollo rock boxes leaked, most all the way from 10 −12 torr to one atmosphere of Earth air.
[0004] Returning humans to the Moon in the near-future will involve many considerations, designs, and engineering projects for exploration and ISRU activities. One factor common to all activities on the Moon is the ever-present, sharp, abrasive, glassy dust. Various ISRU activities will entail movement of the lunar regolith, but conventional means will launch a large portion of dust that will cause numerous problems as it falls back covering such installations as solar cells, for example.
[0005] Because of the presence of nanophase metallic Fe in the impact-produced glass, this “well-graded” soil can be sintered and melted into building blocks, antenna dishes, roads, etc. with the application of microwaves. Published U.S. Patent Application No. US2008/0003133, which is incorporated herein by reference, discloses a system for in-situ microwave consolidation of lunar soil. In addition to converting lunar dust into useful construction materials, the dust can be used for other applications. For example, the surfaces of the dust contain solar-wind particles, providing a potential source of hydrogen for water and fuel.
[0006] However, there is a down-side to the fine portion of the soil, the dust. It is prone to being “kicked up” by most activities on the surface of the Moon, thereby creating a plethora of problems, many experienced during the Apollo Missions, as discussed by Taylor et al., 2005, AIAA, 1st Space Explor. Conf., Orlando, Fla. Therefore, it is imperative to develop a method of handling and collecting lunar regolith that mitigates against the possibility of stirring too much dust into the lunar “atmosphere.”
SUMMARY OF THE INVENTION
[0007] The present invention provides an apparatus and method for transporting lunar soil. A magnetic field is generated in a transport tube which attracts and moves the lunar soil through the tube. The magnetic field may be generated by multiple electrically conductive coils that are positioned coaxially and along the length of the transport tube.
[0008] The dust of the Moon is one of the major environmental challenges that we face in returning to the lunar surface. However, this dust can be of great use in making life on the Moon practical. In accordance with aspects of the present invention, the potential hazard of having this dust suspended above the surface is reduced or eliminated by using magnetic properties that are inherent in the lunar soil to transport the soil to a desired location. The transported lunar soil may then be used for various purposes.
[0009] An aspect of the present invention is to provide an apparatus for transport of lunar soil particles comprising: a transport tube having an interior passageway structured and arranged for the transport of the lunar soil particles therethrough; and a magnetic field generator structured arranged to generate a magnetic field capable of attracting and transporting the lunar soil particles through the interior passageway of the transport tube.
[0010] Another aspect of the present invention is to provide a method of transporting lunar soil particles, the method comprising: generating a magnetic field in the proximity of the lunar soil particles; and transporting the soil particles with the magnetic field.
[0011] These and other aspects of the present invention will be more apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a partially schematic illustration of a lunar soil transport system in accordance with an embodiment of the present invention.
[0013] FIG. 2 is a partially schematic illustration of a lunar soil transport system in accordance with another embodiment of the present invention.
[0014] FIG. 3 is a back-scattered electron (BSE) image of Apollo 17 lunar soil;
[0015] FIG. 4 is an Fe X-ray map of the same soil illustrating the thin rim of metallic Fe on some of the soil grains; and
[0016] FIG. 5 is a TEM image of the same mature lunar soil sample, illustrating the presence of nano-phase metallic iron particles (np-Fe 0 ) on the surfaces of the soil grains.
[0017] FIG. 6 is a BSE image of Apollo 17 lunar soil; FIG. 7 is an Fe X-ray map of the same soil showing the thin rim of metallic Fe on some grains; and FIG. 8 is a TEM image of the same immature lunar soil sample, illustrating the presence of nanophase metallic Fe (np-Fe 0 ) on the surface of each soil particle.
DETAILED DESCRIPTION
[0018] FIG. 1 schematically illustrates a lunar soil transport system 10 in accordance with an embodiment of the present invention. The system 10 includes a tube having an inlet end 12 , an outlet end 14 , and an interior passageway 16 therebetween. Several electrically conductive coils 20 - 28 are provided along the length of the passageway 16 . Introduction of current through the coils 20 - 28 generates a magnetic field along the passageway 16 which attracts iron-containing lunar soil particles 30 and transports the individual particles 32 through the interior 16 of the system 10 . By selectively controlling the current through the coils 20 - 28 , the soil particles 32 are first introduced through the inlet end 12 by the magnetic field generated by the coil 20 , and are transported along the length of the passageway 16 by alternatingly introducing current through the next coil in the sequence, while removing the current or reversing the direction of current in the preceding coil in order to draw the lunar soil particles along the length of the tube.
[0019] As shown in FIG. 1 , the wound coils 20 - 28 may be individually powered to generate magnetic fields. Soil is picked up by the nose coil 20 and pulled into the center of the transport tube. As this moving soil approaches this first coil 20 , the coil 20 is powered down, and the next coil 21 in the sequence is powered up and attracts the particles of soil further into the tube. As the soil approaches the second coil 21 , it too is powered down, and the next coil 22 in the sequence is powered up to tractor the soil further down the line. This process of turning coils on and off continues in a “caterpillar/millipede effect” moving the soil particles along this electronic-conveyor belt. A lunar surface-mining operation may use this device to gather and transport soil and dust across great distances to processing plants.
[0020] FIG. 2 schematically illustrates a lunar soil particle transport system 110 in accordance with another embodiment of the present invention. The main transport tube has an internal passageway 116 surrounded by multiple electrically conductive coils 120 for selectively generating magnetic fields in the passageway 116 . A smaller feeder tube 140 having a relatively rigid section 142 and flexible section 146 is in flow communication with the interior passageway 116 of the main tube. The feeder tube 140 has an inlet end 144 and is connected to the main tube at its outlet end 148 . Multiple electrically conductive coils 122 surround the feeder tube 140 for generating magnetic fields therein. In the embodiment shown in FIG. 2 , the inlet end 144 of the feeder tube 140 is positioned adjacent to a mound 130 of planetary soil, and the feeder tube 140 is used to draw the lunar soil particles through the feeder tube 140 by the magnetic fields generated by the coils 122 . The lunar soil particles exit the feeder tube 140 into the main tube 116 for transport to a desired location.
[0021] The system illustrated in FIG. 2 provides a trunk line that is capable of large magnetic fields and moving large amounts of material with several feeder lines. The feeder lines branch off of the trunk line, pulling in material from the surrounding area. This allows for several areas to be excavated simultaneously. As the regolith is exhausted in one large area, the trunk line can be extended to new areas. The magnetic fields must be sufficiently strong as to attract the soil from a reasonable distance and accelerate it to a speed sufficient to carry it to the next coil through momentum. In the case of the Moon, this is eased somewhat by both the absence of atmosphere and the ⅙th G gravity on the Moon (lighter to pick up vertically, and less drop in horizontal transport). It is also necessary to control the on-off timing needed to energize and relax consecutive rings, in order to keep a continuous flow of soil through the tube. The feedback-loop timing will maintain efficiency.
[0022] The present invention provides a system to mitigate the lunar dust problem utilizing its ferromagnetic properties, due to the presence of nanophase metallic Fe in the ˜40-50% impact glass of the lunar soil. The presence of 80-90% glass in the dust makes this portion of the soil capable of being attracted by a simple magnet. The presence of this Fe bearing glass in larger agglutinates also renders a magnetic susceptibility to the larger grain-sized soil particles. It should be possible to effectively “suck-up” the regolith using magnetic fields. This can be done in a similar fashion to the way maglev trains and coil guns (or gauss weapons) work, by using consecutive electro-magnets to pull an object along. A major advantage of these technologies is that there are no moving parts in the device. Such an attracting systems applied to the Moon would not only pull the soil along, but effectively capture the dust as well.
[0023] FIG. 3 is a back-scattered electron image, FIG. 4 is an Fe X-ray map, and FIG. 5 is a TEM image of a mature lunar soil sample, Apollo 17 Sample No. 79221, illustrating the presence of nanophase metallic iron particles (np-Fe 0 ) on the surface of each soil particle.
[0024] FIG. 6 is a back-scattered electron image, FIG. 7 is an Fe X-ray map, and FIG. 8 is a TEM image of an immature lunar soil sample, Apollo 17 Sample No. 71061, illustrating the presence of nanophase metallic iron particles (np-Fe 0 ) on the surface of each soil particle.
[0025] As shown in the back-scattered electron images of FIGS. 3 and 6 , there are many plagioclase grains (CaAl 2 Si 2 O 8 ), as well as ilmenite (FeTiO 3 ) grains. In the Fe X-ray maps of FIGS. 4 and 7 , a thin Fe rim is present on the plagioclase grains, giving them a significant bulk magnetic susceptibility. Both the mature ( FIG. 4 ) and immature ( FIG. 7 ) lunar soils have vapor-deposited coatings on rims of most grains. In the TEM images of FIGS. 5 and 8 , the fine-grained nature of the nanophase Fe 0 on the plagioclase grains is shown.
[0026] Lunar soil, especially lunar agglutinitic glass which is a major component in lunar dust, contains nano-sized metallic Fe (np-Fe 0 ). The np-Fe 0 typically has a size of less than 50 nm for example, from 3 to 30 nm. Such a np-Fe 0 may pose severe problems for humans and equipment. However, the presence of np-Fe 0 allows the lunar soil to be attracted by magnetic forces, and transported and stored in accordance with the present invention.
[0027] Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
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An apparatus and method for transporting lunar soil is disclosed. A magnetic field is generated in a transport tube which attracts and moves the lunar soil through the tube. The magnetic field may be generated by multiple electrically conductive coils that are positioned coaxially and along the length of the transport tube.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, in general, to an output multiplexer and more particularly to a four-to-one output multiplexer having only a one gate delay for the data transmission.
2. Background Art
Output multiplexers are well known in the art. Typical multiplexers comprise a plurality of gates, each responsive to an input signal, and at least one select output from a select circuit comprising a plurality of gates. The select circuit is responsive to a plurality of digital inputs, thereby determining which of the inputs to the first plurality of gates controls the state of the output.
One well known four-to-one multiplexer circuit includes two OR gates responsive to a pair of select signals having first and second states, each OR gate having a first output representative of the first state and a second output representative of the second state. Four NOR gates, each responsive to an input and to one select output from each of the NOR gates, are connected to a fifth NOR gate for providing an output.
The known prior art has a two gate delay for data transmission, a three gate delay for select transmission, and typically has seven current sources.
Thus, a need exists for an improved multiplexer having fewer gate delays for the data transmission and a reduction in current by using a single current source.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved output multiplexer.
Another object to the present invention is to provide an output multiplexer having only one gate delay for the data transmission.
A further object to the present invention is to provide an output multiplexer having reduced current requirements.
In carrying out the above and other objects of the invention in one form, there is provided an improved output multiplexer having a plurality of input conductors, each responsive to an input having a first and second state, and a plurality of select conductors, each responsive to a select signal, for selecting one input for determining the state of an output. A select circuit includes a plurality of gates, wherein each of the input conductors are coupled to at least two of the gates. Each of the gates has a first gate output having a first and second state and a second gate output having a first and second state, wherein the first and second gate outputs provide a plurality of select outputs. A multiplexer gate is coupled to the plurality of input conductors and the select circuit and is responsive to the select outputs for determining which of the inputs determines the state of an output.
The above and other objects, features, and advantages of the present invention will be better understood from the following detailed description taken in conjunction with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates in logic diagram form the preferred embodiment of the present invention.
FIGS. 2A and 2B illustrate in schematic form the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an output multiplexer 10 is shown which is suitable to be fabricated in monolithic integrated circuit form as well as with discrete components. Multiplexer 10 includes a select circuit 12 and multiplexer circuit 14. Select circuit 12 includes four OR gates 16, 18, 20, 22 which are responsive to select signals. OR gates 16 and 20 are connected to select input conductor 24 and OR gates 18 and 22 are connected to select input conductor 26. Or gate 16 has an output connected as an input to AND gate 30, and an inverse output connected as an input to AND gate 28. OR gate 18 has an output connected as an input to AND gate 28, and an inverse output connected as an input to AND gate 30. OR gate 20 has an output connected as an input to AND gate 32, and an inverse output connected as an input to AND gate 34. OR gate 22 has an output connected as an input to AND gate 32, and an inverse output connected as an input to AND gate 34.
AND gates 28, 30, 32, 34 are representative of transistor collector dotted circuitry that will be discussed in further detail by referring to FIG. 2 and are not gates in the typical sense. This collector dotted circuitry provides for a reduced gate delay over the data transmission of the previously known circuitry.
Digital select signals having high and low states are applied to conductors 24 and 26, thereby providing a digital high on only one of the select circuit outputs 36, 38, 40, 42 which are outputs of AND gates 28, 30, 32, and 34, respectively.
Multiplexer circuit 14 includes AND gates 44, 46, 48, 50, each having an input connected to select circuit outputs 36, 38, 40, 42, respectively. A second input to each of AND gates 44, 46, 48, 50, are connected to multiplexer input conductors 52, 54, 56, 58, respectively. AND gates 44, 46, 48, 50 each have an output connected as an input to OR gate 60. Output conductor 62 from OR gate 60 provides the output for multiplexer 10. Output enable circuit 64 is connected to OR gate 60 and to enable conductor 66.
Referring now to FIGS. 2A and 2B, select circuit 12 includes differentially connected NPN transistors 100 and 102, both having their emitters connected to the collector of current source transistor 104. The collectors of transistors 100 and 102 are connected to nodes 106 and 108, respectively. Node 106 is coupled to node 109 by resistor 112 and is connected to the cathode of diode 114. Node 108 is coupled to node 109 by resistor 116 and is connected to the cathode of diode 118. The anodes of diodes 114 and 118 are connected to node 109. Node 109 is coupled to first supply voltage conductor 110 by resistor 119. Transistor 104 has its base connected to current source voltage V CS and its emitter coupled to second supply voltage conductor 120 by resistor 122. The base of transistor 102 is connected to reference voltage V BB and the base of transistor 100 is coupled to select input conductor 24 by resistor 124.
Differentially connected transistor 100 and 102 function as a switch. For example, when a digital high signal appears on conductor 24, transistor 100 turns on, thereby pulling node 106 low. Transistor 102 is off, thereby causing node 108 to be high. When a low digital signal appears on conductor 24, transistor 100 is off and transistor 102 is on, thereby causing node 106 to be high and node 108 to be low.
Differentially connected NPN transistors 126 and 128 have their collectors connected to nodes 106 and 108, respectively. Both of the emitters of transistors 126 and 128 are connected to the collector of current source transistor 130. The emitter of transistor 130 is coupled to second supply voltage conductor 120 by resistor 132. The base of transistor 128 is connected to reference voltage V BB ' and the base of transistor 126 is connected to the emitter of input translator transistor 134. The collector of transistor 134 is connected to first supply voltage conductor 110 and the base is coupled to select input conductor 26 by resistor 136. The emitter of transistor 134 is connected to the collector of current source transistor 135. The emitter of transistor 135 is coupled to second supply voltage conductor 120 by resistor 137.
Differentially connected transistors 126 and 128 function as a switch similarly to differentially connected transistors 100 and 102. When a digital high signal appears on conductor 26, transistor 134 is turned on, thereby turning on transistor 126 and pulling node 106 low. When a low digital signal appears on conductor 26, transistors 134 and 126 are both off, thereby causing node 106 to be high. Therefore, it is seen that node 106 is high only when both the transistors 100 and 126 are off and node 106 will be low when either of transistors 100, 126 are on. Furthermore, node 108 is high when transistors 102 and 128 are both off and is low when either of transistors 102, 128 are on.
Node 106 is further connected to the base of output translator transistor 138 and node 108 is connected to the base of output translator transistor 140. The collectors of transistors 138 and 140 are both connected to first voltage supply conductor 110. The emitter of transistor 138 is connected to the anode of diode 142 and the emitter of transistor 140 is connected to the anode of diode 144. The cathode of diode 142 is connected to select output 36 and to the collector-of current source transistor 145. The emitter of transistors 145 is coupled to second voltage supply conductor 120 by resistor 146. The cathode of diode 144 is connected to select circuit output 42 and to the collector of current source transistor 148. The emitter of current source transistor 148 is coupled to second supply voltage conductor 120 by resistor 150 and its base is connected to the bases of transistors 130 and 145.
It is readily seen that when node 106 is high, select output follower conductor 36 goes high. When node 108 is high, select output follower conductor 42 goes high.
Most of the remaining portion of select circuit 12 is constructed similar to the portion just discussed. Prime numbers will be used for clarity of description where the circuit elements are similar. Differentially connected transistors 100' and 102' have both of their emitters connected to the collector of current source transistor 104'. The collector of transistor 100' is connected to node 106' and the collector of transistor 102' is connected to node 108'. Node 106' is coupled to node 109' by resistor 112' and is connected to the cathode of diode 114'. Node 108' is coupled to node 109' by resistor 116' and is connected to the cathode of diode 118'. The anodes of diodes 114' and 118' are connected to node 109'. Node 109' is coupled to first supply voltage conductor 110 by resistor 119'. The emitter of transistor 104' is coupled to second supply voltage conductor 120 by resistor 122' and its base is connected to current supply voltage V CS . The base of transistor 100' is coupled to select input conductor 24 by resistor 124. The base of transistor 102' is connected to reference voltage V BB .
Differentially connected transistors 126' and 128' have both of their emitters connected to the collector of current source transistor 130'. The emitter of transistor 130' is coupled to second supply voltage conductor 120 by resistor 132'. The base of transistor 128' is connected to reference voltage V BB '. The base of transistor 126' is connected to the emitter of transistor 134.
Node 106' is connected to the base of output translator transistor 138' and node 108' is connected to the base of output translator transistor 140'. The collectors of transistors 138' and 140' are connected to first supply voltage conductor 110. The emitter of transistor 138' is connected to the anode of diode 142' and the emitter of transistor 140' is connected to the anode of diode 144'. The cathode of diode 142' is connected to select circuit output conductor 38 and the collector of transistor 145'. The emitter of transistor 145' is coupled to second supply voltage conductor 120 by resistor 146'. The cathode of diode 144' is connected to select circuit output conductor 40 and to the collector of transistor 148'. The emitter of transistor 148' is coupled to second supply voltage conductor 120 by resistor 150'. The base of transistor 148' is connected to the base of transistors 130', 135 and 145'.
The operation of select circuit 12 may be further understood by referring to the truth table as follows:
______________________________________Select Inputs Select Circuit Outputson Conductors on Conductors24 26 36 38 40 42______________________________________0 0 1 0 0 00 1 0 1 0 01 0 0 0 1 01 1 0 0 0 1______________________________________
It may be seen, that a digital high will appear on only one of select circuit output conductors 36, 38, 40, and 42, depending on the digital input on select input conductors 24 and 26. For example, a digital low on conductors 24 and 26 will give a digital high on conductor 36 and a digital low on conductors 38, 40 and 42.
Multiplexer circuit 14 includes data transistors 152, 154, 156, and 158 having their bases connected to input conductors 52, 54, 56, and 58, respectively. The collectors of transistors 152, 154, 156, 158 are all connected to first supply voltage conductor 110. The emitter of transistor 152 is connected to a first emitter of gate transistor 160 and to the collector of select transistor 162. The emitter of transistor 154 is connected to a second emitter of transistor 160 and to the collector of select transistor 164. The emitter of transistor 156 is connected to a third emitter of transistor 160 and to the collector of select transistor 166. The emitter of transistor 158 is connected to a fourth emitter of transistor 160 and to the collector of select transistor 168. The base of transistor 160 is connected to reference voltage V BB and the collector is coupled to first supply voltage conductor 110 by load resistor 170. The emitters of transistors 162, 164, 166, 168, are connected to node 169. The bases of transistors 162, 164, 166, 168, are connected to select circuit output conductors 36, 38, 40, 42, respectively. Current source transistor 174 has its collector connected to node 169 and its emitter coupled to second supply voltage conductor 120 by resistor 176. Output transistor 172 has its collector connected to first supply voltage conductor 110 and its base connected to the collector of transistor 160. The emitter of transistor 172 is connected to output conductor 62.
In operation, it may be seen that a digital high on the appropriate select circuit output conductor 36, 38, 40, 42 will transfer the appropriate digital input information on input conductor 52, 54, 56, 58 to the output conductor 62. For example, if a digital high exists on select circuit output conductor 36 and input conductor 52, transistors 152 and 162 are both on. Therefore, transistor 160 is off and a high voltage appears at the base of transistor 172, causing conductor 62 to go high. Since reference voltage V BB is greater than the signal on input conductors 54, 56, 58, transistors 154, 156, 158 will be off. However, remembering that select output conductor 36 is high and since only one select output conductor 36, 38, 40, and 42 may be high at a given time, transistors 164, 166, 168 are off and the second, third, and fourth emitters of transistor 160 cannot draw current from resistor 170.
Furthermore, by example, if a digital high is on input conductor 52 and a digital low is on select output conductor 36, transistor 152 is effectively off. A digital high would then appear on one of the select circuit output conductors 38, 40, or 42. If the high signal was appearing at select circuit output conductor 42, transistor 168 would be on, allowing the input signal on conductor 58 to be seen at output conductor 62.
Output enable circuit 64 includes transistor 178 having its base connected to enable input conductor 66. The collector of transistor 178 is connected to first supply voltage conductor 110 and its emitter is connected to the collector of current source transistor 180. Transistors 182 and 184 are differentially connected, wherein a first emitter of transistor 182 and the emitter of transistor 184 are connected to the collector of current source transistor 186. The emitters of transistors 180 and 186 are coupled to second voltage source conductor 120 by resistors 188 and 190, respectively. The base of transistor 186 is connected to the bases of transistors 180 and 174. The collector of transistor 184 is connected to first supply voltage conductor 110 and the collector of transistor 182 is connected to the base of transistor 172. A second emitter of transistor 182 is connected to node 169.
The output of multiplexer 10 is determined by the voltage across resistor 170. A digital low appearing on enable conductor 66 will cause transistor 182 to be off. The reference voltage V BB ' on the base of transistor 184 causes transistor 184 to be on and current to flow through transistor 184, 186 and resistor 190. A digital high on output enable conductor 66 causes transistor 182 to turn on. The current previously flowing through transistor 184 is now diverted to transistor 182. The current previously flowing through the appropriate data transistor 152, 154, 156, 158 and the appropriate select transistor 162, 164, 166, 168 is also diverted to flow through transistors 182, 174 and resistors 170, 176. The additional current now flowing through resistor 170 causes the signal on the base of transistor 172 to be very low, thus turning off transistor 172 and disabling output conductor 62.
By now it should be appreciated that there has been provided an output multiplexer that reduces the gate delay of the data transmission and lowers current requirements.
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A multiplexer comprises a select circuit having a plurality of OR gates responsive to digital select signals. Transistors within the OR gates are collector dotted and provide a plurality of select circuit outputs to a plurality of AND gates which are also responsive to a plurality of input signals. The collector dotting of the four OR gates of the select circuit provides a multiplexer having a single gate delay of data transmission. The multiplexer consumes less current by having only a single current source for the AND gates.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/516,656 filed Oct. 31, 2003 (Nomura, “Method and Apparatus for Body Fluid Analysis Using Surface-Textured Optical Materials”), U.S. Provisional Patent Application Ser. No. 60/516,654 filed Oct. 31, 2003 (Nomura, “Plasma Polymerization of Atomically Modified Surfaces”), and U.S. Provisional Patent Application Ser. No. 60/516,655 filed Oct. 31, 2003 (Shebuski et al., “Detection of Acute Myocardial Infarction Precursors”), which hereby are incorporated herein by reference thereto in their entirety.
FIELD OF THE INVENTION
[0002] The present invention is directed generally to a non-destructive plasma polymerization process for modifying atomic oxygen modified textured surfaces which have micron dimension morphology.
BACKGROUND
[0003] Recent technological breakthroughs have yielded atomic oxygen modified plastic substrates with surface texturing with micron dimension morphology. The resultant surface morphology has in some cases yielded steep ridges with heights on the order of about 5 microns and spacing between ridges on the order of a few microns. With these dimensions, it may be possible to separate whole blood, i.e., spatially filter the red blood cells (RBCs) from the blood plasma by taking advantage of the micron dimension morphology of these atomic oxygen textured surfaces given that RBCs are too large (typically on the order of about 7 to 8 microns) to geometrically fit into the valleys between the steep ridges. However, to realize functional biosensors, it would be advantageous if the textured surfaces could undergo a surface treatment which, for example, might modify the surface for attachment of analyte sensing chemistries, such as antibodies, and simultaneously not destroy (smooth out) the micron dimension morphology of the textured surface. There is a need for a non-destructive process to chemically modify the topology of textured surfaces with micron dimension morphology.
[0004] Plasma polymerization and treatment are processes to modify the surface of membrane materials to achieve specific functionality. Such surfaces may be modified to become wettable, non-fouling, slippery, crosslinked, reactive, reactable and/or catalytic. The plasma polymerization process is a chemical bonding technology in which a plasma is created at or near ambient temperatures in a modest vacuum, causing a gaseous monomer to chemically modify the surface of a substrate material. Polymers obtained by the plasma process are chemically and structurally similar to starting monomers, but there are differences. Analysis by X-ray photoelectron spectroscopy (XPS) indicates that plasma polymers form a network of highly branched and highly crosslinked segments. In addition, the mechanism of polymer formation and deposition combine to achieve excellent adhesion of the ultra-thin polymer layer to the substrate. As a result, gas plasma generated hydrophilic polymers are very stable in the presence of water, whereas commonly available hydrophilic polymers tend to readily dissolve in water.
[0005] In biosensor applications, affinitive materials can be prepared by plasma polymerization techniques. The development of bio-affinitive materials involves the selection of base materials, covalent coupling chemistry, and ligands. One feature of a plasma polymerization surface-modified composite sensor is its high reactivity and specific selectivity. It is standard practice to perform a blood analysis to separate plasma from whole blood via filtration techniques. This use of blood plasma eliminates common problems encountered when red blood cells (RBCs) are present in the sample, such as optical interference (light absorption and light scattering) and plasma volume displacement. The resulting measurement can be significantly different from those obtained directly on whole blood.
[0006] Plasma polymerization surface-textured composite membrane sensors separate blood plasma from whole blood with minimal complication, and allow the direct use of whole blood as the sample for blood analysis while reducing sample size. Although most biosensors have been designed and calibrated to be used with plasma, few have been built with the capability of separating plasma from a whole blood sample. The textured surfaces of biosensors modified by the plasma polymerization process will impart selectivity to exclude RBCs, thereby promoting a plasma/RBC separation which allows the plasma to penetrate into a reactive core layer. Current biosensors utilizing plasma modified surfaces are typically planar and the plasma polymerization process tends to remove surface irregularities and generate a smooth finished surface.
SUMMARY OF THE INVENTION
[0007] In one particular embodiment of the present invention, a plasma polymerization method is described which modifies the surface of a plastic fiber which has been pre-treated with atomic oxygen texturing to generate micron dimension morphology on the distal end of the fiber. The plasma polymerization method causes a gaseous monomer to chemically modify the textured surface of the PMMA fiber without destroying the micron dimension morphology that existed prior to the polymerization.
[0008] In another embodiment of the present invention, a plasma polymerization method is described which modifies the surface of a planar film or sheet which has been pre-treated with atomic oxygen texturing to generate micron dimension morphology on the film or sheet. The plasma polymerization method causes a gaseous monomer to chemically modify the surface of the film or sheet without destroying the micron dimension topology that existed prior to polymerization.
[0009] The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description, which follow more particularly, exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention may be more completely understood with the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
[0011] FIG. 1 schematically illustrates a system to perform plasma polymerization according to an embodiment of the present invention.
[0012] FIG. 2 schematically illustrates a side view of the system in FIG. 1 to perform plasma polymerization according to an embodiment of the present invention.
[0013] FIG. 3 shows a scanning electron micrograph (SEM) (magnified 10,000×) of an atomic oxygen textured plastic surface prior to plasma polymerization.
[0014] FIG. 4 shows a scanning electron micrograph (SEM) (magnified 10,000×) of an atomic oxygen textured plastic surface after plasma polymerization according to an embodiment of the present invention.
[0015] FIG. 5 schematically illustrates a side view of the system to perform the roll-to-roll plasma polymerization according to an embodiment of the present invention.
[0016] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0017] In accordance with the invention being disclosed herein, atomic oxygen surface-textured substrates are modified by the deposition of a plasma polymerizate on their surfaces from a glow discharge gas plasma. In a method of making these improved materials, a gas, or a blend of gases, is fed into an evacuated vacuum chamber. The gas, or blend of gases, is excited to a plasma state by a glow discharge maintained by application of energy in the form of, for example, an audio frequency, a microwave frequency or a radio frequency field. A suitable substrate is exposed to the glow discharge gas plasma, whereby exposed surfaces of the substrate are modified by deposition of a plasma polymerizate. The plasma polymerization process is non destructive to the atomic oxygen modified textured surfaces which have micron dimension morphology.
[0018] The biosensor may be an optical material, such as an optical fiber or optical membrane comprising a plastic or polymer material. The plastic or polymer optical material can be, for instance, polymethylmethacrylate (PMMA), polystyrene, polycarbonate, polyimide, polyamide, polyvinyl chloride (PVC), or polysulfone. The optical fiber comprises a tip which may be textured using an atomic oxygen process. While various surface texturing processes are available, plastic optical materials preferably are textured by etching with atomic oxygen. Generation of atomic oxygen can be accomplished by several known methods, including radio frequency, microwave, and direct current discharges through oxygen or mixtures of oxygen with other gases. Directed beams of oxygen such as by an electron resonance plasma beam source may also be utilized, accordingly as disclosed in U.S. Pat. No. 5,560,781, issued Oct. 1, 1996 to Banks et al., which is incorporated herein in its entirety by reference thereto. Techniques for surface texturing are described in U.S. Pat. No. 5,859,937, which issued Jan. 12, 1999, to Nomura, and which is incorporated herein in its entirety by reference thereto.
[0019] Atomic oxygen can be used to microscopically alter the surface morphology of polymeric materials in space or in ground laboratory facilities. For polymeric materials whose sole oxidation products are volatile species, directed atomic oxygen reactions produce surfaces of microscopic cones. However, isotropic atomic oxygen exposure results in polymer surfaces covered with lower aspect ratio sharp-edged craters. Isotropic atomic oxygen plasma exposure of polymers typically causes a significant decrease in water contact angle as well as altered coefficient of static friction. Atomic oxygen texturing of polymers is further disclosed and the results of atomic oxygen plasma exposure of thirty-three (33) different polymers, including typical morphology changes, effects on water contact angle, and coefficient of static friction, are presented in Banks et al., Atomic Oxygen Textured Polymers, NASA Technical Memorandum 106769, Prepared for the 1995 Spring Meeting of the Materials Research Society, San Francisco, Calif., Apr. 17-21, 1995, which hereby is incorporated herein in its entirety by reference thereto.
[0020] The general shape of the projections in any particular field is dependent upon the particulars of the method used to form them and on subsequent treatments applied to them. Suitable shapes include conical, ridge-like, pillared, box-like, and spike-like. While the projections may be arrayed in a uniform or ordered manner or may be randomly distributed, the distribution of the spacings between the projections preferably is fairly narrow with the average spacing being such as to exclude certain cellular components of blood such as the red blood cells from moving into the space between the projections. The projections function to separate blood components so that the analyte that reacts with the surface-resident agent is free of certain undesirable body fluid components. In some applications such as the ruling out of acute myocardial infarction using platelet activation markers, the spacings between the projections generally should be great enough to admit the platelets while excluding the red and white blood cells. Atomic oxygen texturing is discussed in more detail in the applications filed concurrently herewith entitled Detection of Acute Myocardial Infarction Biomarkers, which names Ronald J. Shebuski, Arthur R. Kydd, and Hiroshi Nomura as inventors, attorney docket number 1875.2-US-U1 and System and Apparatus for Body Fluid Analysis Using Surface Textured Optical Materials, listing inventor Hiroshi Nomura of Shorewood, Minn., attorney docket number 1875.1-US-U1 which are incorporated herein by reference in their entirety. As a result of atomic oxygen texturing of the tip, the surface of the optical tip includes a plurality of elongated projections. The projections are suitably spaced apart to exclude certain cellular components, such as red and white blood cells, of the body fluid sample, such as blood, from entering into the wells or valleys between the projections, while permitting the remaining part of the body fluid sample, which contains the analyte, to enter into those wells or valleys. Analytes/markers in the plasma, which are indicative of cellular and/or soluble platelet activation and coagulation activation, contacts or associates with the analyte specific chemistries on the surface of the elongated projections, whereupon the analyte and the analyte specific chemistry interact in a manner that is optically detectable. This permits almost instantaneous analysis of the available plasma component of blood. The analyte specific chemistries are attached to the textured surface by way of interacting (e.g., covalent or ionic bonding) with the functional carboxyl groups deposited on the surface during the plasma polymerization process. Activation of the carboxylated supports can be accomplished through use of carboiimides, which couple carboxyl groups to amines forming amide bonds. Carboiimides react, giving O-urea derivatives which enzymes or antibodies can couple via protein amine groups. Conversely, the immobilization can be brought about through the formation of amide bonds between carboxyl groups of proteins (enzymes, antibodies, etc.) and amino groups of the support.
[0021] FIG. 1 illustrates an apparatus in which the plasma polymerization of the atomic oxygen surface textured substrate may be accomplished. An atomic oxygen textured substrate 10 is mounted on a rotating disk 11 within a vacuum chamber 12 having connected thereto an outlet port 13 to a vacuum source (not shown), an inlet port 14 for introduction of the monomer vapor, and an electrical port 15 for introduction of an electrical cable 16 from a frequency signal generator 17 . The rotating disk 11 is driven by a shaft 19 connected to a drive source 20 , such as a motor. The drive source 20 is preferably external to the vacuum chamber 12 , with the drive shaft 19 penetrating a wall or port 18 on the vacuum chamber 12 via a mechanical seal. A monomer flow controller 21 is connected to the monomer vapor inlet port 14 , to control the rate of monomer vapor delivery to the vacuum chamber 12 . Electrode 22 , connected to the signal generator 17 , may be mounted either externally to the vacuum chamber 12 , or internally within vacuum chamber 12 , as shown in FIG. 1 . Electrode 22 may be one or more electrodes, such as a pair of electrodes, as shown in FIG. 1 . An access plate 23 , optionally containing a view port 24 , provides a means of access into the vacuum chamber 12 .
[0022] FIG. 2 shows a side view of the apparatus of FIG. 1 , as seen from the direction of the access plate 23 . Atomic oxygen textured substrates 10 are mounted on the rotating disk 11 , which carries them between a pair of electrodes 22 (one shown) within vacuum chamber 12 . A pressure transducer 25 is also shown, mounted on the vacuum chamber 12 by means of another port 26 .
[0023] When a single electrode 22 is utilized, the frequency signal is transmitted to this electrode. When a pair of electrodes 22 is used, one electrode may be the signal-transmitting electrode and the other electrode may be a ground electrode. Electrode(s) 22 are preferably positioned so that a glow discharge gas plasma is produced in a region or zone within vacuum chamber 12 in which the substrate 10 to be plasma-treated is either located or passed through. In the apparatus as shown, a pair of electrodes 22 are positioned one on each side of the rotating disk 11 , and substrates 10 mounted on the disk 11 are rotated through a glow discharge region located between the two electrodes 22 . The walls of the vacuum apparatus 12 preferably consist either of glass or metal, or combinations of glass and metallic parts. When a metal is used rather than glass, a view port 24 is customarily placed in a wall of the vacuum chamber 12 to allow for visual observation and confirmation of the presence of a glow discharge during plasma processing.
[0024] The rotational method of exposing substrates to a gas plasma between the electrodes allows more than one atomic oxygen textured substrate to be exposed to essentially the same plasma treatment conditions. Other apparatus designs and other techniques for bringing an atomic oxygen textured substrate into contact with a gas plasma may be employed. For instance, a continuous, uninterrupted exposure of an atomic oxygen textured substrate to a gas plasma may be employed for a time sufficient to modify the surface of the substrate with a suitable deposit of a plasma polymerizate. The particular apparatus in FIGS. 1 and 2 is not to be taken as limiting in the practice of the invention. Variations in the design and operation of a gas plasma apparatus may be utilized, as would be evident to one skilled in the art. As an example, continuous sheeting of an atomic oxygen textured substrate may be processed by roll-to-roll movement of the sheeting through a zone of gas plasma, is within the scope of the invention, utilizing an apparatus designed for that purpose.
[0025] The roll-to-roll method is depicted schematically in FIG. 5 . A roll-to-roll unit 500 is shown wherein reaction tunnel 1 is connected at each end by means of flange joints 2 to a pair of bell chambers having base plates 3 and movable bell housings 4 . The bell housings 4 seal to the base plates 3 when the chambers are evacuated, but may otherwise be moved away for access to system components and workpieces in the chamber interiors. Provision is made for evacuating the system by means of vacuum ports 5 located on each of the base plates. The vacuum ports 5 are connected to a vacuum source (not shown) by means of a line that contains a valve 6 which is controlled by a pressure sensing monitor 7 so as to maintain system pressure at a level consistent with gas plasma treatment, i.e., normally in the range of 0.01 to 2 torr. Though not shown here, vacuum ports may also be individually equipped with on-off valves to allow evacuation through one bell chamber selectively rather than both bell chambers simultaneously. A reactive gas (e.g., polymerizable monomers), a mixture of reactive gases, or a mixture of reactive and nonreactive gases is fed through one or more inlet ports 8 . Glow discharge electrodes 9 having electrical leads 10 extending therefrom are externally mounted to the reaction tunnel 1 . During plasma treatment, the system is evacuated, reactive gas is fed to the system to a desired pressure level, glow discharge electrodes 9 are electrically activated to produce a gas plasma in the reaction tunnel 1 , and the article to be treated is fed through the reaction tunnel from one bell chamber to the other. Though depicted as bell-shaped in FIG. 5 , the bell housings 4 may be otherwise shaped, with appropriate configuring of the base plate for assembly and sealing purposes. The base plates 3 may be fixed to a track by means of permanent mountings, and the bell housings 4 are mounted to movable brackets that slide on the track. This allows the bell housings 4 to be easily moved away from the base plates 3 for access to system components and workpieces located inside the bell chambers. It is generally advantageous for system components located inside the bell chambers to be mounted to the base plates 3 rather than the movable bell housings 4 . The mounting may be made directly to the base plate or indirectly made by means of a frame or scaffold anchored to the base plate.
[0026] As described above, the plasma polymerization process is amenable to both the rotational and roll-to-roll method of exposing substrates. In the rotational method the substrates are periodically being exposed to the gas plasma, whereas in the roll-to-roll method the substrates (in sheet form) pass through the plasma zone at a constant linear speed. In one embodiment of the rotational method, the gas plasma may be sustained by excitation power in the range of 10 to 50 watts and driven at a frequency in the range of 20 to 100 kilohertz (kHz) for approximately 1 to 30 minutes, preferably 2 to 10 minutes. Also, in this embodiment of the rotational method, the vacuum chamber environment may be in the range of 100 to 1,000 millitorr.
[0027] In the roll-to-roll method, the gas plasma may be sustained by excitation power in the range of 50 to 200 watts and driven at a frequency near 13.56 Megahertz (MHz). Also, in the roll-to-roll method the vacuum chamber environment may be set in the range of 200 to 1,000 millitorr. In the roll-to-roll method the substrate sheet may be passing through the plasma zone at a linear speed in the range of 0.1 to 10 cm/sec for a dwell time in the plasma of 1 to 120 seconds.
[0028] As an example of a method of making a plasma polymerized atomic oxygen textured substrate for use in genomic, immunoassay, or cardiac marker sensing in accordance with the present invention, one or more atomic oxygen textured substrates are mounted on rotating disk 11 in vacuum chamber 12 . Vacuum chamber 12 is closed and may be evacuated to less than 1.0 torr, preferably to about 30 millitorr or less. A monomer vapor is introduced into vacuum chamber 12 generally in a continuous flow. Plasma system pressure is maintained at a preselected pressure level, typically 100 to 1,000 millitorr, through control of the monomer inflow rate and the vacuum outflow rate. Rotation of disk 11 is started, and a glow discharge is initiated through the monomer vapor by means of a signal transmitted from signal generator 17 through electrode pair 22 . A plasma polymerizate forms on the surface or surfaces of the substrates 10 where the surfaces are exposed to the glow discharge gas plasma.
[0029] Unlike conventional polymerization, in the plasma process, several parameters should be controlled in order to obtain desired surface properties. The plasma excitation energy (watts) controls the degree of crosslinkage on substrate 10 . Monomer flow rate (sccm) controls the deposition rate on substrate 10 . The monomer molecular weight (gm) affects the atomic composition on substrate 10 . Further, system pressure (mtorr) affects the functional group deposited on substrate 10 . Exposure time (min.) controls the coating thickness on substrate 10 . Polymerization mode (continuous, pulse, graft) relates to the uniformity and morphology on substrate 10 .
[0030] The character (e.g., intensity, reactivity, radical, or ionized form) of the gas plasma may be controlled according to the composite plasma parameter W/FM where W is the power input to the gas plasma from the signal generator, F is the flow rate of the monomer gas/vapor, and M is the molecular weight of the particular monomer selected for plasma polymerization. The nature of the plasma polymerizate that is deposited is in turn controlled by the composite plasma parameter, but also reflects the nature of the polymerizable monomer or monomers fed to the gas plasma. In addition to this composite plasma parameter and to monomer selection, exposure time of the substrate 10 to the gas plasma is also preferably controlled. Additional control may be exercised by generating an intermittent glow discharge such that the plasma polymerizate deposited on a substrate 10 surface may have time to interact with the monomer vapor in the absence of glow discharge, such that some grafting of the monomer may be effected. Additionally, the resulting plasma polymerizate may be exposed to unreacted monomer vapor in the absence of a glow discharge as a post-deposition treatment, such that residual free radicals may be quenched.
[0031] Polymerizable monomers that may be used in the practice of the invention may comprise unsaturated organic compounds such as halogenated olefins, olefinic carboxylic acids and carboxylates, olefinic nitrile compounds, olefinic amines, oxygenated olefins and olefinic hydrocarbons. Such olefins include vinylic and allylic forms. The monomer need not be olefinic, however, to be polymerizable. Cyclic compounds such as cyclohexane, cyclopentane and cyclopropane are commonly polymerizable in gas plasmas by glow discharge methods. Derivatives of these cyclic compounds, such as 1,2-diaminocyclohexane, for instance, are also commonly polymerizable in gas plasmas. Particularly preferred are polymerizable monomers containing hydroxyl, amino or carboxylic acid groups. Of these, particularly advantageous results have been obtained through use of allylamine or acrylic acid. Mixtures of polymerizable monomers may be used. Additionally, polymerizable monomers may be blended with other gases not generally considered as polymerizable in themselves, such as argon, nitrogen and hydrogen.
[0032] Modification of substrates with selected monomers and varied coating thicknesses could make significant changes in surface functionality. Biofunctional plasma polymer surfaces may be classified as: 1) inert hydrophobic; 2) acidic-oxygen containing; and 3) basic nitrogen-containing functional groups. Attachment of functional groups or modification to inert surfaces will be carried out by plasma polymerization (graft, continuous mode) of monomers with five typical groups, as set forth in Table 1 below.
TABLE 1 Plasma Monomers Functional Group Monomer Functional Acidic —COOH Acrylic acid (CH 2 ═CHCOOH) —OH Allyl alcohol (CH 2 ═CHCH 2 OH) —SH Ethyl mercaptan (CH 3 CH 2 SH) Basic —NH 2 Allylamine (CH 2 ═CHCH 2 NH 2 ) 1,2-Diaminocyclohexane (C 6 H 10 (NH 2 ) 2 ) Inert Tetrafluoroethylene (CF 2 ═CF 2 ) Hexamethyldisiloxane (CH 3 ) 3 SiOSi(CH 3 ) 3 Methane (CH 4 )
[0033] The polymerizable monomers are preferably introduced into the vacuum chamber in the form of a vapor. Polymerizable monomers having vapor pressures less than 0.01 torr are not generally suitable for use in the practice of this invention. Polymerizable monomers having vapor pressures of at least 0.05 torr at ambient room temperature are preferred. Where monomer grafting to plasma polymerizate deposits is employed, polymerizable grafting monomers having vapor pressures of at least 1.0 torr at ambient conditions are particularly preferred.
[0034] The gas plasma pressure in the vacuum chamber 12 may vary in the range of from 0.01 torr to 2.0 torr, more preferably in the range of 0.05 to 1.0 torr. To maintain desired pressure levels in chamber 12 , especially since monomer is being consumed in the plasma polymerization operation, there generally is continuous inflow of monomer vapor to the plasma zone, generally between 1 sccm to 200 sccm, preferably 2-100 sccm. When nonpolymerizable gases are blended with the monomer vapor, continuous removal of excess gases is accomplished by simultaneously pumping through the vacuum port 13 to a vacuum source. Since nonpolymerizable gases may result from glow discharge gas plasmas, it is advantageous to control gas plasma pressure at least in part through simultaneous vacuum pumping during the plasma polymerizate deposition process on a substrate 10 .
[0035] The glow discharge through the gas or blend of gases in the vacuum chamber 12 may be initiated by means of an audio frequency, a microwave frequency or a radio frequency field transmitted to or through a region or zone in the vacuum chamber 12 . Particularly preferred is the use of a radio frequency (RF) discharge, transmitted through a spatial zone in the vacuum chamber 12 by an electrode 16 connected to an RF signal generator 17 . A more localized and intensified gas plasma is attained by means of an electrode pair 22 , whereas a more diffuse gas plasma is a result of a single electrode. A broad range of RF signal frequencies from about may be used to excite and maintain a glow discharge through the monomer vapor. In commercial scale usage of RF plasma polymerization, an assigned radio frequency of 13.56 MHz may be desirable to avoid potential radio interference problems.
[0036] The glow discharge may be continuous, or it may be intermittent during plasma polymerizate deposition. A continuous glow discharge may be employed, or exposure of a substrate surface 10 to the gas plasma may be intermittent during the overall polymerizate deposition process. In addition, both a continuous glow discharge and a continuous exposure of a substrate surface 10 to the resulting gas plasma for a desired overall deposition time may be employed. The plasma polymerizate that deposits onto the atomic oxygen textured substrate 10 generally will not have the same elemental composition as the incoming polymerizable monomer (or monomers). During the plasma polymerization, some fragmentation and loss of specific elements or elemental groups naturally occurs. Thus, in the plasma polymerization of allylamine, nitrogen content of the plasma polymerizate is typically lower than would correspond to pure polyallylamine. Similarly, in the plasma polymerization of acrylic acid, carboxyl content of the plasma polymerizate is typically lower than would correspond to pure polyacrylic acid. Exposure time to either of these unreacted monomers in the absence of a gas plasma, as through intermittent exposure to a glow discharge, allows for grafting of the monomer to the plasma polymerizate, thereby increasing the level of the functional group (i.e., amine or carboxylic acid) in the final deposit. Time intervals between gas plasma exposure and grafting exposure can be varied from a fraction of a second to several minutes to achieve the desired polymer thickness, using for example the rotational method illustrated in FIG. 1 and FIG. 2 .
[0037] FIG. 3 shows a scanning electron micrograph (SEM) of an atomic oxygen textured plastic surface prior to plasma polymerization. The substrate material is the distal end of a polymethyl methacrylate (PMMA) plastic optical fiber supplied by the Mitsubishi Rayon Co. (ESKA Optical Fiber Division) part # CK-120. The fiber diameter is 3 mm and the scanning electron micrograph is at 10,000 times magnification. The atomic oxygen texturing of the PMMA fiber distal end was performed at a fluence level which yielded 3.9×10 20 atoms/cm 2 .
[0038] FIG. 4 shows a scanning electron micrograph (SEM) of the same atomic oxygen textured plastic PMMA fiber shown in FIG. 3 after plasma polymerization according to an embodiment of the present invention. The plasma polymerization was carried out with a methane/acrylic acid mixture injected into the vacuum chamber at 400 millitorr, as set forth below in Example 1. The RF power was set to 100 watts throughout the deposition, and the deposition time was approximately 60 seconds. FIG. 4 is also at 10,000 times magnification, but the image shows a different region of the plastic PMMA fiber distal end-face than FIG. 3 . However, as can be seen in FIG. 4 , the pre-polymerization surface morphology survived the plasma polymerization step.
[0039] Plasma polymer surfaces can be evaluated for stability (i.e., shelf life) based on surface analysis. Scanning Electron Microscopy (SEM), Fourier Transfer Infra-Red (FTIR), and X-ray Photoelectron Spectroscopy (XPS, ESCA) can be used to determine the change of surface atomic compositions, surface morphology and surface functionality. In addition, dye binding (ion exchange capacity) can be used to evaluate stability. Dye binding (ion exchange capacity) measurements can be performed. The density of acidic functional groups (such as carboxyl) will be determined using a positive-charge dye, Toluidine Blue (TB). The density of basic functional groups (such as amines) will be determined using a negative-charge dye, Bromthymol Blue (BTB). Measurements can be made by a spectrophotometer at 626 nm for TB and at 612 nm for BTB.
[0040] Plasma polymer surfaces are relatively stable if proper plasma conditions are applied. Dye binding capacities of several plasma modified surfaces stored for more than six months were found to be essentially unchanged.
TABLE 2 Stability of Plasma Polymer Surface (Ion Exchange Capacity) Density of Density of Functional Group Functional Group (nmol/cm 2 ) at (nmol/cm 2 ) after Interval Materials present 4/95) coated (Months) Carboxyl Group (—COOH) Nylon Membrane A 927 932 8 Nylon Membrane B 854 901 8 Carboxyl Hollow Fiber 30.3 24.3 22 Membrane Nylon Bead 303 415 8 Polystyrene Beads 16.9 2.4 8 Amine group (—NH 2 ) Polypropylene Hollow 9.54 5.6 21 Fiber Membrane Polystyrene Beads 6.4 1.7 8
EXAMPLE 1
[0041] The tip of an optic fiber (ESKA-CK120, core: polymethyl methacrylate, clad: fluorinated polymer, diameter; 3 mm, Mitsubishi Rayon Co.) was exposed to atomic oxygen effective fluence of 3.9×10 20 atoms/cm 2 . The textured surface is shown in scanning electron micrograph (SEM) FIG. 3 . A plasma co-polymer of acrylic acid-methane was deposited on the atomic oxygen textured optic fiber surface. Monomers were introduced to the reaction chamber by gas flow controller for methane at 54.4 sccm (standard temperature and pressure per cubic centimeter) and the flow rate of acrylic acid was controlled by a needle valve connected to evaporation jar at 14.9 sccm. System pressure was controlled at 400 millitorr by an adaptive pressure controller with control butterfly valves. Plasma glow was initiated and sustained at 100 watts (13.56 MHz). Plasma glow zone was 15 cm which is equal to the electrode length. The optical fiber was attached on the support film, e.g. polyethylene Terephthalate (PET), and traveled through the plasma zone at 0.25 cm/sec, with a resulting resident time of 60 seconds in the plasma zone. As shown in the SEM in FIG. 4 , the structure of the atomic oxygen texture was kept intact with the plasma co-polymer deposition.
EXAMPLE 2
[0042] The tip of an optic fiber (ESKA-CK120, core: polymethyl methacrylate, clad: fluorinated polymer, diameter; 3 mm, Mitsubishi Rayon Co.) was exposed to atomic oxygen effective fluence of 3.82×10 21 atoms/cm 2 (Sample # 1 ), 1.43 ×10 21 atoms/cm 2 (Sample # 2 ), and 1.07×10 21 atoms/cm 2 (Sample # 3 ), respectively. Sample # 3 was masked with salt particles. The textured surface is shown in scanning electron micrograph (SEM) FIG. 3 . A plasma polymer of acrylic acid was deposited on the atomic oxygen textured optic fiber surface. PET film and untextured optic fiber are also modified as controls. Argon gas was used as a co-existing inert gas. Gaseous flow rates were 115.2 sccm (cm 3 (STP)/minute) for argon and 3 sccm (cm 3 (STP)/minute) for acrylic acid, respectively. System pressure was 800 millitorr and RF power was 30 watts at 50 kHz. Plasma discharge time was for 2 minutes. Total polymer deposition was 1800 angstroms (Å). The deposition rate was measured with a thin film thickness and rate monitor and thickness was normalized by density=1.0 grams/cm 3 . The functional density of carboxyl function groups were determined with a positive charge dye, Toluidine Blue (measured at 626 nm in 0.01 N HCl) as listed in Table 1. PET film is selected as control because of an inert surface. PMMA (Polymethyl methaacrylate) has some negative charge and atomic oxygen textured surfaces have non characterized negatively charged sites which is relatively large amount in the range 78 to 150 by atomic oxygen. A plasma polymer of acrylic acid replaced the such non characterized site with a carboxyl function group and increased the functional density. Because maximum population of Toluidine blue is calculated to be 1.46/nm 2 (Stokes' Radius: 4.45 Å) on a planar surface, for PET film surface, plasma deposition create about 8 layers of carboxyl function groups and about 28 layers for PMMA non-textured optic fiber. PMMA surface is more reactive than PET for acrylic acid monomer. The textured surface of the optical fiber obtained 3 to 4 times higher density compared to non-textured optic fiber and the density of function group (such as carboxyl groups) of 120 to 165 (1/nm 2 ) is extremely high and very advantageous for sensor miniaturization.
TABLE 3 Density of Carboxyl Functional Group Functional Group Number of - (A) - Concentration COOH group control Sample (nmol/cm 2 ) (A) (1/nm 2 ) (1/nm 2 ) PET film Control 0.62 4 0 Modified Control 2.74 16 12 Optic fiber Control 10.6 63 0 AO textured S1 28.0 168 105 AO textured S2 23.6 141 78 AO textured S3 35.5 213 150 Modified Control 17.5 105 42 Modified AO textured S1 30.6 183 120 Modified AO textured S2 36.3 218 155 Modified AO textured S3 37.9 227 164
EXAMPLE 3
[0043] Plasma co-polymer of acrylic acid-methane was deposited on the atomic oxygen textured optic fiber surface, as set forth in Example 2. Monomers were introduced to a reaction chamber by gas flow controller for methane at 36 sccm (cm 3 (STP)/minute). The flow rate of acrylic acid was controlled by a needle valve connected to evaporation jar at 4 sccm (cm 3 (STP)/minute). System pressure was controlled at 170 millitorr. RF power was 20 watts at 50 kHz. Discharge time was 10 minutes. Total polymer deposition was 7000 angstroms (Å). Even with the thicker deposition layer the effectiveness of functional group density was saturated at the level of 150 (1/nm 2 ).
TABLE 4 Density of Carboxyl Functional Group Functional Group Number of - Concentration COOH group (A) Sample (nmol/cm 2 ) (1/nm 2 ) Control 0.0 0 Modified AO textured S1 27.6 166 Modified AO textured S2 23.7 142 Modified AO textured S3 26.3 158
[0044] The sensor geometries of both the fiber optic and membrane configuration are described in U.S. patent applications filed concurrently herewith entitled, “System and Apparatus For Body Fluid Analysis Using Surface-Textured Optical Materials”, by inventor Hiroshi Nomura, and methods and devices to detect heart attack precursors in U.S. patent application entitled “Detection of Acute Myocardial Infarction Biomarkers”, by inventors Ronald Shebuski, Arthur Kydd and Hiroshi Nomura as attorney docket numbers 1875.0001-US-U1 and 1875.0002-US-U1 respectively, both of which are incorporated herein by reference in its entirety.
[0045] The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification. The claims are intended to cover such modifications and devices.
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The invention is directed to a plasma polymerization method is which modifies the surface of plastic fibers which have been pre-treated with atomic oxygen texturing to generate micron dimension morphology on the distal end of the fiber. The plasma polymerization method causes a gaseous monomer to chemically modify the surface of the fiber without destroying the micron dimension topology that existed pre-polymerization.
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This application is a division of application Ser. No. 09/835,590 filed on Apr. 17, 2001, now U.S. Pat. No. 6,565,217; which is a Division of application Ser. No. 08/907,970, filed Aug. 11, 1997, now U.S. Pat. No. 6,251,482, which is a Continuation of application Ser. No. 8/435,721, filed May 5, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for forming a silver coating on a surface of a vitreous substrate, in particular to the silvering of glass, that is to say the chemical deposition of a coating of silver, using a silvering solution.
Such a metal coating may be deposited pattern-wise to form a decorative article, but the invention has particular reference to glass substrates bearing a continuous reflective coating. The coating may be applied to a substrate of any form, for example to an artistic object, to achieve some desired decorative effect, but it is envisaged that the invention will find greatest use when the coating is applied to a flat glass substrate. The reflective coating may be so thin that it is transparent. Glass panes bearing transparent reflective coatings are useful inter alia as solar screening panels or as low-emissivity (in respect of infrared radiation) panels. Alternatively, the coating may be fully reflective, thus forming a mirror-coating. Such a process is also used for the formation of silvered glass microbeads (that is to say microbeads carrying a coating of silver), which may for example be incorporated in a plastics material matrix to form a reflective road-marking paint or a conductive plastics material.
2. Description of the Related Art
Conventionally, silver mirrors are produced as follows. The glass is first of all polished and then sensitised, typically using an aqueous solution of SnCl 2 . After rinsing, the surface of the glass is usually activated by means of an ammoniacal silver nitrate treatment. The silvering solution is then applied in order to form an opaque coating of silver. This silver coating is then covered with a protective layer of copper and then one or more coats of paint in order to produce the finished mirror.
The silver coating does not always adhere sufficiently to the substrate. In the case of certain prior products, it has been observed that the silver coating comes away spontaneously from the glass substrate. This is, for example, the case when silvered microbeads manufactured in a normal manner are incorporated in a plastics matrix.
SUMMARY OF THE INVENTION
The aim of the invention is to improve the adhesion of such a silver coating to the glass and thus to improve the durability of this silver coating.
According to a first aspect of the invention, there is provided a process for forming a silver coating on a surface of a vitreous substrate, comprising an activating step in which said surface is contacted with an activating solution, a sensitising step in which said surface is contacted with a sensitising solution, and a subsequent silvering step in which said surface is contacted with a silvering solution comprising a source of silver to form the silver coating, characterised in that said activating solution comprises ions of at least one of bismuth (III), chromium (II), gold (III), indium (III), nickel (II), palladium (II), platinum (II), rhodium (III), ruthenium (III), titanium (III), vanadium (III) and zinc (II).
The characteristic of the invention therefore is to “activate” the substrate by treating it with a specific activating solution before silvering.
It has been observed that the treatment of glass using an activating solution according to the present invention improves the adhesion of the silver coating.
The sensitising step contributes to improving the adherence of the silver coating and therefore its durability. Preferably the sensitising step is carried out before said silvering step. This sensitising step is typically carried out with a sensitising solution comprising tin (II) chloride.
Preferably, said sensitising step is carried out prior to the activating step. We have observed that the order of the steps is important to obtain good durability. This observation is very surprising because the activation treatment does not really produce a distinct continuous layer containing bismuth (III), chromium (II), gold (III), indium (III), nickel (II), palladium (II), platinum (II), rhodium (III), ruthenium (III), titanium (III), vanadium (III) or zinc (II), but they are in the form of islets on the surface of the glass. An analysis of the surface of glass treated with a sensitising solution containing tin (II) chloride followed by an activating solution containing palladium (II) shows the presence of a certain proportion of palladium atoms with respect to tin atoms at the glass surface. Typically, one finds about 0.4 atoms of palladium per atom of tin, and 0.3 atoms of tin per atom of Si at the surface of the glass.
The activation treatment according to the invention may be effected on various types of vitreous substrates, for example on glass microbeads. It has been observed that the treatment according to the invention improves the adhesion of the silver coating subsequently deposited on the glass microbeads. When such silvered microbeads are incorporated in a plastic, it is found that the coating of silver has less of a tendency to peel away from the bead than if the activation treatment according to the invention is omitted. The invention can also be implemented on flat glass substrates, and it is believed that the invention will be particularly useful for this type of substrate. Consequently, the treatment is preferably effected on a flat glass substrate, such as a glass sheet.
The layer of silver may be deposited in the form of a silver coating which is fairly thin so that it is transparent. Flat glass substrates carrying such transparent coatings are used to form glazing panels which reduce the emission of infrared radiation and/or which protect from solar radiation. Thus according to one embodiment of the invention the thickness of the layer of silver formed in said silvering step is between 8 nm and 30 nm.
However, the treatment is preferably applied to glass substrates onto which a thick opaque silver coating is subsequently applied in order to form a mirror. Such embodiments of the invention, where the product is a mirror, are used for example as domestic mirrors or as vehicle rear-view mirrors. The invention makes it possible to produce mirrors on which the silver coating has an improved adhesion to the glass. Thus according to another embodiment the thickness of the layer of silver formed in said silvering step is between 70 nm and 100 nm.
According to the present invention, the activation of the glass is effected before silvering by treating the glass substrate with a specified activating solution. It is observed that the silver coating of the mirror produced in this way has better adhesion than that of a mirror manufactured by the conventional process.
The improvement of the adhesion of the silver coating obtained by the process according to the present invention is observed in different ways.
The adhesion of a silver coating to its glass substrate may be assessed quickly by testing using adhesive tape: an adhesive tape is applied to the silver coating and then pulled off. If the silver coating is not adhering well to the glass, it comes away from the glass when the tape is pulled off.
The degree of adhesion of the silver coating to the glass can also be observed by subjecting the product to an accelerated ageing test such as the CASS Test or Salt Fog Test. It is sometimes found that the product subjected to such tests has a certain edge corrosion and/or light diffusing specks (“white specks”).
The activation treatment according to the invention affords another advantage. We have observed that the silvering reaction on glass activated according to the invention is more effective, that is to say the reaction yield is greater. It is possible to achieve yields improved by around 15% compared with silvering effected on a glass activated in a conventional manner, with a solution of ammoniacal silver nitrate. This presents advantages from the economic point of view since one can use less reagents to form the same thickness of silver coating and also from the environmental point of view since the quantity of waste from the silvering reaction to be eliminated can be reduced.
It is conventional to protect the silver coating with an overcoating of copper to retard tarnishing of the silver layer. The copper layer is itself protected from abrasion and corrosion by a layer of paint. Those paint formulations which afford the best protection against corrosion of the copper layer contain lead pigments. Unfortunately lead pigments are toxic and their use is being increasingly discourage for reasons of environmental health.
It has recently been proposed to protect the silver coating by treatment with an acidified aqueous solution of Sn (II) salt (see British patent application GB 2252568). According to another recent proposal, the silver coating is protected by treatment with a solution containing at least one of Cr (II), V (II or III), Ti (II or III), Fe (II), In (I or II), Cu (I) and Al (III) (see British patent application GB 2254339). We have observed that the activation treatment according to the present invention is particularly useful for the manufacture of such products. One important application of the protection treatments according to GB 2252568 and GB 2254339 is the formation of silver mirrors which do not include a conventional protective layer of copper. Such mirrors can be protected with lead-free paints. The activation treatment according to the present invention is particularly advantageous for the manufacture of such mirrors. This is because the activation treatment of the glass during the manufacture of mirrors protected with such treatment significantly improves the adhesion of the silver coating of such mirrors and therefore their durability. Consequently, the invention applies preferably to the manufacture of mirrors with no copper layer, and in particular to mirrors formed by a process in which the silver coating is subsequently contacted with a solution containing ions of at least one of the group consisting of Cr (II), V (II or III), Ti (II or III), Fe (II), In (I or II), Sn (II), Cu (I) and Al (III).
The glass substrate may be brought into contact with the activating solution by dipping in a tank containing an activating solution but, preferably, the glass substrate is brought into contact with the activating solution by spraying with a solution containing an activating solution. This is particularly efficacious and practical in the case of flat glass substrates, for example during the industrial manufacture of flat mirrors, in which sheets of glass pass through successive stations where sensitisation, activation and then silvering reagents are sprayed.
We have observed that the glass substrate may be effectively activated by a rapid treatment using the specified activating solution. It has been observed that the glass/activating solution contact time may be very short, for example around a few seconds only. In practice, in the industrial production of flat mirrors, the sheet of glass moves along a mirror production line on which the glass passes through an activation station where the activating solution is sprayed, then through a rinsing station and afterwards through the silvering station.
The activating solution preferably comprises a source of palladium, most preferably a palladium (II) salt in aqueous solution, in particular PdCl 2 in acidified aqueous solution.
The activating solution may be used very simply and economically. The PdCl 2 solution may have a concentration of from 5 to 130 mg/l. We have observed that bringing the glass substrate into contact with a quantity of from 1 to 23 mg, preferably at least 5 mg of PdCl 2 , per square metre of glass is entirely sufficient to activate the glass substrate effectively. In fact, we have observed that the use of quantities of PdCl 2 higher than about 5 or 6 mg PdCl 2 /m 2 does not afford any significant improvement. Therefore it is preferred to treat the glass substrate with about 5 or 6 mg of PdCl 2 per square metre of glass.
We have found that best results can be obtained when the pH of said activating solution is from 2.0 to 7.0, most preferably from 3.0 to 5.0. This pH range allows solutions to be formed which are both stable and effective for activating the glass. For example, when using palladium, below pH=3.0 the level of palladium deposited on the glass substrate may be reduced, leading to a poor quality product. Above pH=5.0, there is a risk of precipitation of palladium hydroxide.
According to a second aspect of the invention, there is provided a mirror comprising a vitreous substrate carrying a silver coating which is not covered with a protective layer of copper, the mirror exhibiting an average number of white specks of less than 10 per dm 2 , preferably less than 5 per dm 2 , after having been subjected to the accelerated ageing CASS Test and/or the Salt Fog Test defined below. Such a silver mirror without a copper layer is advantageous since the silver coating adheres well and has good durability.
The silver coating may be covered with one or more protective paint layers and according to a preferred aspect of this invention such a paint is free, or substantially free, of lead. Where more than one such paint layer is used, the paint layers other than the uppermost paint layer may contain lead. However, for environmental health reasons, lead sulphate and lead carbonate in the lower paint layers are preferably absent so that where lead is present in these lower layers it is preferably in the form of lead oxide.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be further described, purely by way of example, in the following examples.
EXAMPLE 1+CONTROL 1
Mirrors are manufactured on a conventional mirror production line in which sheets of glass are conveyed along a path by a roller conveyor.
The sheets of glass are first of all polished, rinsed and then sensitised by means of a tin chloride solution, in the normal manner, and then rinsed.
An acidic aqueous solution of PdCl 2 is then sprayed onto the sheets of glass. This solution is prepared from a starting solution containing 6 g of PdCl 2 /l acidified with HCl in order to obtain a pH of approximately 1, and diluted with demineralised water in order to feed spray nozzles which direct the dilute solution, which contains 60 mg PdCl 2 /l, onto the sheets of glass, so as to spray approximately 11 mg of PdCl 2 /m 2 of glass.
The sheets of glass thus activated then pass to a rinsing station where demineralised water is sprayed, and then to the silvering station where a traditional silvering solution is sprayed, comprising a silver salt and a reducing agent. This is achieved by simultaneously spraying a solution A containing ammoniacal silver nitrate and heptagluconic acid and a solution B containing ammoniacal sodium hydroxide. The flow rate and concentration of the solutions sprayed onto the glass are controlled so as to form, under conventional production conditions, a layer containing approximately 800-850 mg/m 2 of silver. It is observed that the mass of silver deposited is higher by approximately 135 mg/m 2 of silver, ie approximately 935-985 mg/m 2 of silver.
A coppering solution of a usual composition is sprayed onto the silver coating in order to form a coating containing approximately 300 mg/m 2 of copper. This is achieved by simultaneously spraying a solution A and a solution B. Solution A is prepared by mixing an ammonia solution with a solution containing copper sulphate and hydroxylamine sulphate. Solution B contains citric acid and sulphuric acid. The glass is then rinsed, dried and covered with a Levis epoxy paint. This paint comprises a first coat of approximately 25 μm of epoxy and a second coat of approximately 30 μm of alkyd. Mirrors are allowed to rest for 5 days to ensure complete curing of the paint layers.
Mirrors manufactured in this manner are subjected to various accelerated ageing tests.
One indication of the resistance to ageing of a mirror incorporating a metallic film can be given by subjecting it to a copper-accelerated acetic acid salt spray test known as the CASS Test in which the mirror is placed in a testing chamber at 50° C. and is subjected to the action of a fog formed by spraying an aqueous solution containing 50 g/l sodium chloride, 0.2 g/l anhydrous cuprous chloride with sufficient glacial acetic acid to bring the pH of the sprayed solution to between 3.0 and 3.1. Full details of this test are set out in International Standard ISO 3770-1976. Mirrors may be subjected to the action of the saline fog for different lengths of time, whereafter the reflective properties of the artificially aged mirror may be compared with the reflective properties of the freshly formed mirror. We find that an exposure time of 120 hours gives a useful indication of the resistance of a mirror to ageing. We perform the CASS Test on 10 cm square mirror tiles, and after exposure to the copper-accelerated acetic acid salt spray for 120 hours, each tile is subjected to microscopic examination. The principal visible evidence of corrosion is a darkening of the silver layer and peeling of the paint around the margins of the mirror. The extent of corrosion is noted at five regularly spaced sites on each of two opposed edges of the tile and the mean of these ten measurements is calculated. One can also measure the maximum corrosion present at the margin of the tile to obtain a result which is again measured in micrometres.
A second indication of the resistance to ageing of a mirror incorporating a metallic film can be given by subjecting it to a Salt Fog Test which consists in subjecting the mirror to the action, in a chamber maintained at 35° C., of a salt fog formed by spraying an aqueous solution containing 50 g/l sodium chloride. We find that an exposure time of 480 hours to the Salt Fog Test gives a useful indication of the resistance of a mirror to ageing. The mirror is again subjected to microscopic examination, and the corrosion present at the margin of the tile is measured to obtain a result in micrometres, in the same way as in the CASS Test.
Mirrors measuring 10 cm square manufactured according to Example 1 are subjected to the CASS and salt fog tests, along with Control samples not according to the invention.
These Control samples are manufactured from sheets of glass as described in Example 1, except that the PdCl 2 activation stage followed by a rinsing is omitted. This step is replaced by a traditional activation step, by spraying with an ammoniacal solution of silver nitrate.
The results of the two ageing tests on the mirror of Example 1 and the Control sample 1 are as set out in the following TABLE I:
TABLE I
CASS test
Salt fog test
Density of white specks
average in μm
average in μm
average number/dm 2
Example 1
334
97
0
Control 1
480
153
0
The mirrors according to Example 1 and Control 1 do not show any white specks after these two tests.
The treatment consisting of the activation of the glass with palladium (II) chloride before silvering according to Example 1 therefore reduced the corrosion at the edges of the mirror, which shows better adhesion of the silver, compared with a mirror on which the glass has been activated in a conventional manner with ammoniacal silver nitrate.
EXAMPLES 2 AND 3 & CONTROLS 2 AND 3
Mirrors according to the invention are manufactured on a conventional mirror production line in which sheets of glass are conveyed along a path by a roller conveyor.
The sheets of glass are first of all polished, rinsed and then sensitised by means of a tin chloride solution, in the usual manner, and then rinsed.
An acidic aqueous solution of PdCl 2 is then sprayed onto the sheets of glass. This solution is prepared from a starting solution containing 6 g of PdCl 2 /l acidified with HCl in order to obtain a pH of approximately 1, and diluted with demineralised water in order to feed spray nozzles which direct the dilute solution, which contains about 30 mg PdCl 2 /l, onto the sheets of glass, so as to spray approximately 5.5 mg of PdCl 2 /m 2 of glass. The contact time of the palladium chloride on the surface of the sensitised glass is approximately 15 seconds.
The sheets of glass thus activated then pass to a rinsing station where demineralised water is sprayed, and then to the silvering station where a traditional silvering solution is sprayed, comprising a silver salt and a reducing agent. The flow rate and concentration of the silvering solution sprayed onto the glass are controlled so as to form, under conventional production conditions, a layer containing approximately 800-850 mg/m 2 of silver. It is observed that the mass of silver deposited is higher by approximately 100 mg/m 2 of silver, ie approximately 900-950 mg/m 2 of silver.
The glass is then rinsed. Directly after the rinsing of the silver coating, a freshly formed acidified solution of tin chloride is sprayed onto the silvered glass sheets moving forward, as described in patent application GB 2252568.
The mirrors are then treated by spraying with a solution containing 0.1% by volume of y-aminopropyl triethoxysilane (Silane A 1100 from Union Carbide). After rinsing and drying, the mirrors are covered with a Levis paint. This paint comprises a first coat of approximately 25 μm of epoxy and a second coat of approximately 30 μm of alkyd (Example 2).
In a variant (Example 3), the mirrors are covered not with a Levis paint but with Merckens paint in two coats of alkyd with a total thickness of approximately 50 μm. The two coats of paint were specifically an undercoating of Merckens SK 8055 and the overcoating was Merckens SK 7925. These two coats contain lead. The mirrors are allowed to rest for 5 days to ensure complete curing of the paint layers.
Mirrors manufactured in this way are subjected to CASS accelerated ageing and salt fog tests.
Two Control samples not in accordance with the invention are also subjected to the same tests.
These Control samples are manufactured from sheets of glass as described above, except that the step consisting of activation with PdCl 2 followed by rinsing is omitted. This step is replaced by a traditional activation step, by spraying with an ammoniacal solution of silver nitrate.
The results of the ageing tests on the mirrors of Examples 2 and 3 and the Control samples 2 and 3 are as set out in the following TABLE II:
TABLE II
CASS test
Salt fog test
Density of white specks
average in μm
average in μm
average number/dm 2
Example 2
140
30
0.7
Control 2
170
110
20 to 50
Example 3
100
<6
1.0
Control 3
130
58
20 to 50
The “white speck” defect is observed after the two tests. This is a point where the silver coating is coming away locally, accompanied by the formation of agglomerations of silver, which appear as a speck diffusing light. These defects are circular in shape, and the average size is between 40 μm and 80 μm. The “density of white specks” value given above is the average number of white specks per dm 2 of glass which are observed after the salt fog test and after the CASS test.
In fact, the number of white specks measured after each of the two tests are generally fairly close to each other. This is probably because this “white specks” defect appears when the mirrors are brought in contact with water (in vapour or liquid phase). The CASS test and salt fog test consist of subjecting the mirror to the action of a mist of an aqueous solution: an aqueous solution of NaCl for the salt fog, an aqueous solution containing sodium chloride, copper (I) chloride and acetic acid in the CASS test. It is therefore not surprising if the number of white specks after each of these tests is relatively similar.
The treatment consisting of the activation of the glass with palladium (II) chloride before silvering according to Examples 2 and 3 therefore reduces the corrosion of the edges of the mirror, compared with a mirror on which the glass has been activated in a conventional manner with ammoniacal silver nitrate. In addition, these mirrors according to Examples 2 and 3 have a very appreciable decrease in the number of white specks after the CASS and salt fog tests. The adhesion of the silver on the glass is therefore greatly improved compared with mirrors on which the glass has been activated in a conventional manner, with silver nitrate.
EXAMPLES 4, 5 AND 6
Mirrors are manufactured as described in Example 2, varying the quantity of palladium chloride sprayed onto the glass. The starting solution containing 6 g of PdCl 2 /l, with a pH of approximately 1, is diluted to varying extents in the spray manifold as follows:
Example 4
12 mg PdCl 2 /l to yield 2.2 mg of PdCl 2 per m 2 of glass;
Example 5
about 30 mg PdCl 2 /l to yield 5.6 mg of PdCl 2 per m 2 of glass; and
Example 6
60 mg PdCl 2 /l to yield 11 mg of PdCl 2 per m 2 of glass.
The results of the ageing tests on the mirrors according to these Examples 4, 5 and 6 are as set out in the following TABLE III:
TABLE III
CASS test
Salt fog test
Density of white specks
average in μm
average in μm
average number/dm 2
Example 4
181
60
18
Example 5
166
16
1
Example 6
163
16
1
The “white speck” defect is observed only after the CASS test. The number of “white specks” after salt fog was not measured.
It is therefore observed that the activation of the glass by spraying with 2.2 mg of PdCl 2 per m 2 of glass provides a mirror which resists ageing tests relatively well. However, the density of white specks after the CASS test diminishes spectacularly if not 2.2 but 5.6 mg of PdCl 2 /m 2 of glass is sprayed. The spraying of higher quantities of PdCl 2 (cf Example 6: 11 mg of PdCl 2 /m 2 of glass) does not afford any significant improvement.
EXAMPLES 7 TO 11 AND CONTROL 4
Mirrors are formed as described in Example 3, by varying the quantity of palladium chloride which is sprayed onto the glass. Initially, the solution contains 6 g PdCl 2 /l, with a pH of 1. This solution is diluted as set out in the following TABLE IV:
TABLE IV
Solution
Spraying level
EXAMPLE
mg PdCl 2 /l
mg PdCl 2 /m 2
Example 7
6
1.1
Example 8
12
2.2
Example 9
30
5.5
Example 10
60
11
Example 11
120
22
The mirrors which were formed in this manner were subjected to CASS tests and salt fog tests. At the same time a control sample, not according to the present invention, was subjected to the same tests. The control sample was formed from glass sheets as described in Example 3, save that the activation step with PdCl 2 was omitted. This step was replaced by a usual activation step by spraying with ammoniacal silver nitrate.
The “white speck” observation is made after the CASS test and after the Salt Fog Test. The results were as set out in TABLES Va and Vb.
TABLE Va
CASS test
White specks
EXAMPLE
average in μm
average/dm 2
Control 4
124
47
Example 7
254
40
Example 8
156
24
Example 9
101
3
Example 10
102
3
Example 11
129
2
TABLE Vb
Salt fog test
White specks
EXAMPLE
average in μm
average/dm 2
Control 4
41
10
Example 7
87
41
Example 8
52
7
Example 9
13
1
Example 10
13
1
Example 11
5
1
From these results it is apparent that the activation of the glass by spraying 1.1 or 2.2 mg PdCl 2 /m 2 of glass results in a mirror which resists the ageing tests relatively well. Furthermore, the density of white specks after the CASS test becomes very low if the level of PdCl 2 is increased to 5.5 mg/m 2 of glass. Higher levels of PdCl 2 (for example as used in Examples 10 and 11) do not lead to a significant further improvement.
EXAMPLES 12 TO 15 AND CONTROL 5
Mirrors are formed as described in Example 3, with the following variations:
Example 12
About 6 mg PdCl 2 /m 2 is sprayed onto glass, instead of 5.5 mg PdCl 2 /m 2 . The quantity of PdCl 2 is also increased to about 6 mg PdCl 2 /m 2 of glass in Examples 13 to 15.
Example 13
The sensitisation step with stannous chloride is omitted.
Example 14
The activation step with PdCl 2 is carried out before the sensitisation step with stannous chloride.
Example 15
The step of protecting the silver coating by treatment with a freshly formed acidified solution of stannous chloride was not carried out. The silvered sheets of glass were directly covered with Merckens paint.
Control 5
Mirrors not according to the invention were formed as described in Example 12 except that the activation step with PdCl 2 followed by rinsing is replaced by a traditional activation step, by spraying an ammoniacal solution of silver nitrate.
The mirrors formed according to Examples 12 to 15 and Control 5 were subjected to an accelerated CASS ageing test. Corrosion of the margins and the density of white specks after this test were as set out in the following TABLE VIa:
TABLE VIa
CASS test
White specks
EXAMPLE
average in μm
average/dm 2
Control 5
395
32
Example 12
165
2
Example 13
2700
*
Example 14
650
46
Example 15
3200
55
* The silver coating was so destroyed at the glass/silver interface that the identification of white specks was not possible.
The mirrors formed according to Examples 12, 13, 14 and 15, and Control 5 are subjected to the Salt Fog Test. The corrosion of the margins and the density of white specks after the Salt Fog Test were as set out in the following TABLE VIb:
TABLE VIb
Salt fog test
White specks
EXAMPLE
average in μm
average/dm 2
Control 5
70
47
Example 12
41
2
Example 13
760
*
Example 14
93
46
Example 15
132
>125
* The silver coating was so destroyed at the glass/silver interface that the identification of white specks was not possible.
It can be seen, by comparison of the results of Examples 12 and 13, that it is important to sensitise the glass before activation with PdCl 2 . The order of the sensitisation and activation steps is very important: when activation is carried out before sensitisation worse ageing results are achieved (see Example 14). Example 15 shows that it is important to protect the silver coating before painting.
EXAMPLES 16 TO 21
Mirrors are formed as described in Example 2, except that the activation solution is poured over the glass instead of being sprayed. 500 ml of acidified solution is poured over 0.5 m 2 of glass. The contact time of the solution on the surface of the sensitised glass is approximately 30 seconds. The following activation solutions were used:
Example 16
an acidified aqueous solution containing 6 mg/l PdCl 2 . The pH was 3.8
Example 17
an acidified aqueous solution containing 10.0 mg/l AuCl 3 (pH=4.1).
Example 18
an acidified aqueous solution containing 10.2 mg/l PtCl 2 (pH=4.0).
Example 19
an acidified aqueous solution containing 6.7 mg/l RuCl 3 (pH=4.0).
Example 20
an acidified aqueous solution containing 8.1 mg/l NiCl 2 .6H 2 O (pH=4.3).
Example 21
an acidified aqueous solution containing 3.6 mg/l CrCl 2 (pH=4.2).
The mirrors formed in Examples 16 to 21 were subjected to accelerated CASS ageing and salt fog tests. Corrosion of the edges and the density of white specks after these tests were as set out in the following TABLEs VIIa and VIIb:
TABLE VIIa
CASS test
White specks
EXAMPLE
average in μm
average/dm 2
Control 6#
477
0
16 (PdCl 2 )
143
7
17 (AuCl 3 )
262
55
18 (PtCl 2 )
204
*
19 (RuCl 3 )
187
8
20 (NiCl 2 .6H 2 O)
298
34
21 (CrCl 2 )
180
3
TABLE VIIb
Salt fog test
White specks
EXAMPLE
average in μm
average/dm 2
Control 6#
214
0
16 (PdCl 2 )
53
5
17 (AuCl 3 )
117
73
18 (PtCl 2 )
107
*
19 (RuCl 3 )
53
6
20 (NiCl 2 .6H 2 O)
82
46
21 (CrCl 2 )
39
10
#Control 6 is a mirror similar to Control 1, that is a traditionally formed silver mirror carrying a coating of copper to protect the silver layer.
* The surface of the silver coating showed a number of aligned faults indicating separation of the silver.
It can be seen that all the salts used for the activation solutions used in Examples 16 to 21 give improved results from the point of view of marginal corrosion following the CASS test compared with traditionally produced mirrors carrying a coating of copper. Best results were obtained with Pd (II), Cr (II), and Ru (III).
EXAMPLES 22 TO 24
Example 3 was followed except that in Example 22 the two coats of paint were specifically an undercoating of Merckens SK9085 (a lead-containing paint in which the lead is in the form of lead oxide) and the overcoating was Merckens SK8950 (lead-free). The results obtained were compared with a modification (Example 23) in which the undercoating was Merckens SK9135 (a lead-containing paint in which the lead is present in the form of oxide) and the overcoating was Merckens SK8950 (lead-free) and in a second modification (Example 24) in which the undercoating was Merckens SK8055 (a lead-containing paint in which the lead is present in the form of carbonate, sulphate and oxide) and the overcoating was Merckens SK8950. The results of the tests on the products obtained are set out in the following TABLE VIIIa and VIIIb:
TABLE VIIIa
CASS test
White specks
EXAMPLE
average in μm
average/dm 2
Example 22
164
1
Example 23
85
0
Example 24
118
2
TABLE VIIIb
Salt fog test
White specks
EXAMPLE
average in μm
average/dm 2
Example 22
19
0.5
Example 23
22
0
Example 24
22
0.5
EXAMPLES 25 TO 27
The procedure of Example 2 was followed except that the activating solution was acidified with various different amounts of hydrochloric acid to give dilute solutions (i.e. solutions sprayed on the glass) with different pHs. The samples obtained were tested with the CASS test and the Salt fog test and were also analyzed to determine the level of palladium deposited on the substrate in the activation step. In the following tables of results (TABLES IXa and IXb), the level of palladium is expressed as the atomic ratio to silicon. The presence of those palladium atoms, and their proportion in relation to the silicon atoms present on the glass may be estimated by an X-ray bombardment technique which causes the ejection of electrons from a surface stratum of the glass. From the X-ray beam energy and the energy of the emitted electrons, it is possible to calculate the binding energy of the electrons so that they may be apportioned between specific electron shells of different atomic species. The atomic ratios of palladium and silicon may then readily be calculated. This analysis is generally realised on the activated glass before silvering and painting. The presence of palladium (or other atom according to the type of activation solution used) may also be analyzed by Secondary Ion Mass Spectroscopy.
TABLE IXa
Activator
Pd/Si
CASS test
White specks
Example
(pH ± 0.5)
ratio
average in μm
average/dm 2
Example 25
PdCl 2 (3.5)
0.12
71
0
Example 26
PdCl 2 (4.5)
0.16
65
1
Example 27
PdCl 2 (2.5)
0.03
76
2
TABLE IXb
Activator
Pd/Si
Salt fog test
White Specks
Example
(pH ± 0.5)
ratio
average in μm
average/dm 2
Example 25
PdCl 2 (3.5)
0.12
15
0.5
Example 26
PdCl 2 (4.5)
0.16
18
0
Example 27
PdCl 2 (2.5)
0.03
76
9
These results show that if the pH is low, the level of palladium fixed on the substrate is low and the results are less good. If the pH is higher than 5, a precipitate of palladium hydroxide may result in blockages of the apparatus.
EXAMPLES 28 TO 43
Using the procedure as described in connection with Examples 16 to 21, a number of activating solutions were used as follows.
Example 28
acidified aqueous solution containing 10.7 mg/l AuCl 3 (pH=4.6).
Example 29
acidified aqueous solution containing 5.9 mg/l PtCl 2 (pH=3.5).
Example 30
acidified aqueous solution containing 8.2 mg/l NiCl 2 .6H 2 O (pH=4.6).
Example 31
acidified aqueous solution containing 5.9 mg/l PdCl 2 (pH=4.6).
Example 32
acidified aqueous solution containing 5.9 mg/l PdCl 2 (pH=4.1).
Example 33
acidified aqueous solution containing 8.3 mg/l InCl 3 (pH=4.6).
Example 34
acidified aqueous solution containing 8.3 mg/l InCl 3 (pH=4.1).
Example 35
acidified aqueous solution containing 4.4 mg/l ZnCl 2 (pH=4.6).
Example 36
acidified aqueous solution containing 4.4 mg/l ZnCl 2 (pH=4.1).
Example 37
acidified aqueous solution containing 54.6 mg/l BiCl 3 (pH=4.6). Note that BiCl 3 is only slightly soluble.
Example 38
acidified aqueous solution containing 54.6 mg/l BiCl 3 (pH=3.5).
Example 39
acidified aqueous solution containing 7.8 mg/l RhCl 3 .3H 2 O (pH=4.6).
Example 40
acidified aqueous solution containing 7.8 mg/l RhCl 3 .3H 2 O (pH=4.1).
Example 41
acidified aqueous solution containing 5.4 mg/l VCl 3 (pH=4.6).
Example 42
acidified aqueous solution containing 5.4 mg/l VCl 3 (pH=4.1).
Example 43
acidified aqueous solution containing 5.8 mg/l TiCl 3 (pH=4.5).
The mirrors were subjected to the CASS test. Some metal/silicon ratios were estimated on activated glass. The results were as follows.
TABLE X
CASS test
White specks
Ratio
Example No
average in μm
average/dm 2
Me/Si
28 (AuCl 3 pH = 4.6)
219
1
0.03
29 (PtCl 2 pH = 3.5)
131
20
0.007
30 (NiCl 2 .6H 2 O pH = 4.6)
144
19
0.028
31 (PdCl 2 pH = 4.6)
161
1.5
0.032
32 (PdCl 2 pH = 4.1)
106
0
0.076
33 (InCl 3 pH = 4.6)
127
3
34 (InCl 3 pH = 4.1)
123
10
0.045
35 (ZnCl 2 pH = 4.6)
141
9
36 (ZnCl 2 pH = 4.1)
126
11
0.006
37 (BiCl 3 pH = 4.6)
155
11
38 (BiCl 3 pH = 3.5)
180
13
39 (RhCl 3 .3H 2 O pH = 4.6)
149
29
40 (RhCl 3 .3H 2 O pH = 4.1)
167
8.5
0.016
41 (VCl 3 pH = 4.6)
164
2
42 (VCl 3 pH = 4.1)
179
4.5
0.014
43 (TiCl 3 pH = 4.5)
256
33.5
0.012
Best results are obtained with the use of AuCl 3 , PdCl 2 , InCl 3 , VCl 3 : the mirrors exhibit an average number of white specks of less than 5 per dm 2 . With ZnCl 2 or RhCl 3 .3H 2 O, the mirrors exhibit an average number of white specks comprised between 5 and 10 per dm 2 .
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A domestic or vehicle rearview silvered mirror having a silver coating which is not covered with a protective layer of copper. The silver mirror comprises a glass sheet, tin and preferably palladium at surface of the glass sheet, a silver coating of the surface of the glass sheet and at least one paint layer covering the silver coating. Optionally, tin may be present at the surface of the silver coating adjacent the paint layer and optionally traces of silane may be present at the surface of the silver coating adjacent to the paint layer. Alternate or additional materials may be present at a surface of the glass sheet and alternate or additional materials may be present at the surface of the silver adjacent to the paint layer.
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TECHNICAL FIELD
The present invention relates to a raw material for producing a ruthenium thin film or a ruthenium compound thin film by a chemical deposition method. Specifically, the present invention relates to a raw material for chemical deposition formed of a ruthenium complex, which has suitable stability and a high vapor pressure.
BACKGROUND ART
As ruthenium complexes that constitute raw materials for forming ruthenium thin films by chemical deposition methods such as a CVD process and an ALD process, various ruthenium complexes have been known heretofore. As the ruthenium complexes that have been reported to be useful among those, the following ruthenium complexes are exemplified.
The above-mentioned two ruthenium complexes are such that carbonyl groups and a polyene having plural double bonds (cyclooctatetraene, cyclohexadiene) are coordinated as ligands for ruthenium. The reasons why these ruthenium complexes are useful as raw materials for chemical deposition method include, firstly, that they have high vapor pressures. A compound having a high vapor pressure can feed a raw material gas at a high concentration, and thus can improve film formation efficiency. Furthermore, these ruthenium complexes also have an advantage that the decomposition temperatures are relatively low. The advantage allows the film formation temperature to be set to a low temperature, and stable formation of a thin film while suppressing the damage of a substrate is enabled.
RELATED ART DOCUMENTS
Patent Documents
Patent Document 1: JP 2010-173979 A
Patent Document 2: JP 2006-57112 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
However, according to the present inventors, the above-mentioned ruthenium complexes have the following points that require improvement. Firstly, either of the above-mentioned ruthenium complexes has an advantage that the decomposition temperature is low, but the temperature tends to be slightly too low. In the formation of a thin film by a chemical deposition method, a raw material container is heated to thereby vaporize a raw material compound, and the raw material gas is then introduced into a film formation chamber, but if the decomposition temperature is too low, decomposition of the raw material compound occurs at the stage of the heating vaporization. This leads to the lowering of the utility rate of the raw material compound.
The second problem of the above-mentioned ruthenium complexes is the production costs thereof. The method for synthesizing the above-mentioned ruthenium complexes is generally by reacting a carbonyl compound of ruthenium and a polyene, but this synthesis reaction does not progress unless the polyene is used in a considerably excess amount. For example, in the ruthenium complex of Chemical Formula 1, dodecacarbonyltriruthenium (DCR) and cyclooctatetraene (derivative) are reacted, and 6 to 7-fold equivalent amount of DCR with respect to the cyclooctatetraene is required. Therefore, excess use of the polyene increased the production cost of the ruthenium complex. Furthermore, with respect to the ruthenium complex of Chemical Formula 1, the synthesis reaction of this complex is basically a photoreaction, and thus irradiation of light is required during the synthesis, and this is also a cause for the increase of the cost for the synthesis.
It is difficult to say that the above-mentioned disadvantages of the ruthenium complexes of Chemical Formulas 1 and 2 are fatal for the formation of thin films. However, in order to utilize chemical deposition methods for the formation of respective electrodes for which further miniaturization or complication or multi-layerization will be intended in the future, it is necessary to apply a ruthenium complex having a suitable decomposition temperature (stability). Furthermore, in order to suppress the cost increase for various devices, the costs for the synthesis of those ruthenium complexes are required to be lower. In addition, the development of a ruthenium complex that responds to these requirements and also has conventionally-required properties (high vapor pressure and low melting point) is desired. The present invention has been made against the above-mentioned background, and aims at providing a raw material for chemical deposition formed of a ruthenium complex, which has a suitable decomposition temperature, a high vapor pressure and such a melting point that the raw material liquefies at an ordinary temperature, and requires low production costs.
Means for Solving the Problems
The present invention, which solves the above-described problem, is a raw material for producing a ruthenium thin film or a ruthenium compound thin film by a chemical deposition method, which is formed of a ruthenium complex, wherein the ruthenium complex is a ruthenium complex represented by the following formula, in which carbonyl groups and a fluoroalkyl derivative of a polyene are coordinated to ruthenium:
( n R-L)Ru(CO) 3 [Chemical Formula 3]
wherein L is a polyene having a carbon number of from 4 to 8 and 2 to 4 double bonds, wherein the polyene L has n (n≧1) pieces of substituents R, wherein the substituents Rs are each a fluoroalkyl group having a carbon number of from 1 to 6 and a fluorine number of from 1 to 13, and in the case when the polyene L has two or more (n≧2) of the substituents Rs, the carbon numbers and the fluorine numbers of the substituents Rs may be different in the same molecule.
The ruthenium complex that constitutes the raw material for chemical deposition according to the present invention is a ruthenium complex to which three carbonyl groups and a polyene in which fluoroalkyl group(s) has/have been introduced as substituent(s) are coordinated as ligands for ruthenium. Specifically, in contrast to the above-mentioned conventional ruthenium complexes, it is a ruthenium complex in which the polyene as a ligand is partially substituted with the fluoroalkyl group(s).
The reason why the fluoroalkyl group(s) is/are introduced in the polyene in the present invention is that the stability of the ruthenium complex is improved to adjust the decomposition temperature thereof to be within a suitable range. This is due to that the bonding between the Ru and polyene is strengthened by introducing fluoroalkyl groups (CF 3 − , C 2 F 5 − and the like), which are electron withdrawing groups, into the polyene, and thus the stability of the ruthenium complex molecule is increased, and the decomposition at low temperatures is suppressed.
Furthermore, the improvement of the stability by the introduction of the fluoroalkyl group(s) allows easy progress of the reaction for synthesizing the ruthenium complex (the bonding of the ruthenium and polyene). This can significantly reduce the use amount of the polyene in reacting the ruthenium compound and the polyene. Furthermore, this reaction can be progressed by a thermal reaction, and time and effort as in photoreactions are unnecessary. The method for producing the ruthenium complex in the present invention will be mentioned below.
Furthermore, the significance of introducing the fluoroalkyl group(s) as the substituent(s) is that there is an advantage that the vapor pressure is increased more than the cases when other substituent(s) such as alkyl groups including a methyl group and the like is/are introduced. The reason therefor is considered that the Van der Waals force between the molecules is decreased by introducing the fluoroalkyl group(s). By using the ruthenium complex that has a high vapor pressure, a raw material gas with a high concentration can be generated, and thus efficient formation of a thin film is enabled.
Furthermore, the introduction of the substituent(s) into the polyene also has an effect of lowering the melting point of the ruthenium complex to a low temperature, and the introduction of the fluoroalkyl group(s) also exerts this effect. The effect of the lowering of the melting point by the introduction of the substituent(s) increases in accordance with the increase of the molecular weight(s) of the substituent(s). Furthermore, by this way, the ruthenium complex can be in a liquid state even in an ordinary temperature range, and thus the efficiency of the vaporization of the raw material becomes fine in the production of a thin film.
With respect to the constitution of the ruthenium complex that constitutes the raw material for chemical deposition according to the present invention having the above-mentioned advantages, the polyene has a carbon number of from 4 to 8, and has 2 to 4 double bonds. The reason why the carbon number and double bonds are within these ranges is that, if the molecular weight of the polyene is too high, the melting point increases, and thus the polyene becomes solid at room temperature. The polyene includes both a chain polyene and a cyclic polyene. A preferable chain polyene or cyclic polyene has a carbon number of from 4 to 6, and has two double bonds. The reason why the carbon number and double bonds are within such ranges is that a high vapor pressure and suitable stability can be obtained.
Furthermore, the fluoroalkyl groups that are introduced as the substituents in the polyene each has a carbon number of from 1 to 6 and a fluorine number of from 1 to 13. The reason for these ranges is that the vapor pressure is lowered if the carbon number of the fluoroalkyl group becomes too many. Furthermore, a fluoroalkyl group having a carbon number of from 1 to 3 and a fluorine number of from 1 to 7 is preferable. The number (n) of the fluoroalkyl group(s) may be any number as long as one or more group is introduced. Furthermore, in the case when plural fluoroalkyl groups are introduced into the polyene (in the case when n≧2), different fluoroalkyl groups may be introduced, and the carbon numbers and fluorine numbers thereof may be different in the same molecule. A preferable number of the fluoroalkyl group(s) is 1 to 2.
Specific examples of the ruthenium complex in the present invention having the above-mentioned effect include ruthenium complexes having the following structural formulas.
TABLE 1
Structural formula
Name
(Trifluoromethyl-
(Pentafluoroethyl-
cyclohexadiene)
cyclohexadiene)
tricarbonylruthenium
tricarbonylruthenium
Structural formula
Name
(Bistrifluoromethyl-
(Pentafluoroethyl-
cyclohexadiene)
trifluoromethyl-
tricarbonylruthenium
cyclohexadiene)
tricarbonylruthenium
Structural formula
Name
(Trifluoromethylbutadiene)
(Pentafluoroethylbutadiene)
tricarbonylruthenium
tricarbonylruthenium
Structural formula
Name
(Pentafluoroethyl-
(Bistrifluoromethylbutadiene)
trifluoromethylbutadiene)
tricarbonylruthenium
tricarbonylruthenium
Structural formula
Name
(Trifluoromethyl-
(Pentafluoroethyl-
cyclooctatetraene)
cyclooctatetraene)
tricarbonylruthenium
tricarbonylruthenium
Secondly, the method for producing the ruthenium complex that constitutes the raw material for chemical deposition according to the present invention will be described. This ruthenium complex can be synthesized by reacting dodecacarbonyltriruthenium (hereinafter referred to as DCR) and a polyene derivative that has been partially substituted with fluoroalkyl group(s). As mentioned above, since the bonding force between the DCR and polyene derivative is strong in the ruthenium complex of the present invention, the synthesis method therefor progresses relatively easily. Furthermore, at this time, the use amount of the polyene derivative to be reacted with the DCR can be decreased. Specifically, the necessary reaction amount of the polyene derivative with respect to DCR is a 1 to 3-fold equivalent amount (molar ratio). With regard to this point, in the production of the above-mentioned conventional ruthenium complexes (Chemical Formulas 1 and 2), the polyene cannot be coordinated unless excess polyene (cyclooctatetraene, cyclohexadiene), which is in an amount of 6 to 7-fold equivalent amount with respect to DCR, is used. Considering this point, the ruthenium complex in the present invention can be produced by the use of the polyene (derivative) in a smaller amount than conventional amounts, and this can contribute to the decrease of the production cost thereof.
Furthermore, the reaction for synthesizing the ruthenium complex in the present invention can be progressed by only a thermal reaction, and thus does not require the assist of irradiation of light. Specifically, the ruthenium complex in the present invention can be synthesized by only heating the reaction system so as to become 75 to 85° C. This point also contributes to the decrease of the production cost of the complex.
The step for producing the ruthenium complex of the present invention specifically includes dissolving DCR and a polyene derivative in a suitable solvent (for example, hexane or the like), and heating (refluxing) the solvent. The solvent and the unreacted polyene derivative are distilled off from the reaction liquid, and the ruthenium complex can be collected by solvent extraction. The obtained ruthenium complex can be formed into a raw material for chemical deposition by suitable purification.
The method for forming a thin film by the raw material for chemical deposition according to the present invention conforms to a general chemical deposition method. Specifically, a raw material for chemical deposition formed of a ruthenium complex is vaporized to form a reaction gas, this reaction gas is introduced onto a surface of a substrate, and the ruthenium complex on the surface of the substrate is decomposed to precipitate ruthenium. At this time, the ruthenium complex as a raw material can be vaporized by an arbitrary method. Specifically, since the ruthenium complex of the present invention can be formed into a liquid at an ordinary temperature, a system for bubbling the raw material in the raw material container can also be adopted. In addition, thermal vaporization by a vaporizer may also be conducted depending on the use environment.
The temperature for heating the substrate is preferably within the range from 200° C. to 400° C. Since the decomposition temperature of the ruthenium complex of the present invention is a moderately low temperature, a film can be formed within this temperature range. Furthermore, it is preferable that the atmosphere in the reactor is a reduced pressure atmosphere at from 5 to 10,000 Pa.
Advantageous Effect of Invention
As explained above, the ruthenium complex that is applied in the present invention has suitable stability and decomposition temperature, and also has a high vapor pressure. Furthermore, the producing method therefor is also optimized, and thus the production is possible at a relatively low cost. The raw material for chemical deposition according to the present invention can be preferably used in chemical deposition such as a CVD process and an ALD process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a TG-DTA curve of (trifluoromethyl-cyclohexadiene)tricarbonylruthenium produced in this embodiment.
FIG. 2 is a TG-DTA curve of (cyclohexadiene)tricarbonylruthenium as a conventional art.
FIG. 3 is a SEM photograph of the ruthenium thin film produced from the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium produced in this embodiment.
DESCRIPTION OF EMBODIMENTS
First Embodiment
In this embodiment, (trifluoromethyl-cyclohexadiene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of cyclohexadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 70 g of trifluoromethyl-cyclohexadiene was further dissolved. The trifluoromethyl-cyclohexadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 85° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (trifluoromethyl-cyclohexadiene)tricarbonylruthenium.
The yield amount of the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium obtained by the above-mentioned step was 66.3 g, and the yield thereof was 84%. As mentioned above, trifluoromethyl-cyclohexadiene in a twice equivalent amount with respect to DCR was used in this embodiment, and only a thermal reaction was conducted. Accordingly, (trifluoromethyl-cyclohexadiene)tricarbonylruthenium can be produced at a sufficient yield even under a condition in which no photoreaction is used and the reaction amount of the polyene is suppressed.
Secondly, the physical properties of the produced (trifluoromethyl-cyclohexadiene)tricarbonylruthenium were evaluated. Firstly, an analysis by TG-DTA was conducted. The analysis conditions were a heating temperature range in the air: room temperature to 500° C., and a temperature raising velocity: 5° C./min. In this analysis, (cyclohexadiene)tricarbonylruthenium (Chemical Formula 2), which is a conventional ruthenium complex, was similarly analyzed for the purpose of comparison.
FIG. 1 is a TG-DTA curve of the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium in this embodiment. FIG. 2 is a TG-DTA curve of (cyclohexadiene)tricarbonylruthenium as a comparative example. From these analysis results, firstly, when the temperature at which the evaporation of the ruthenium complex initiated and the temperature at which the evaporation was completed are seen, the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium in this embodiment began to evaporate at around 90° C., and the evaporation was completed at around 140° C. On the other hand, the (cyclohexadiene)tricarbonylruthenium began to evaporate at around 80° C., and the evaporation was completed at around 130° C. When the evaporation temperatures are considered, these evaporation temperatures are not different significantly, and the temperature of the (cyclohexadiene)tricarbonylruthenium is slightly lower than that of the other. However, when the DTA curve of the (cyclohexadiene)tricarbonylruthenium is seen, the generation and disappearance of the exothermic peak are seen at the temperature around or more than the temperature at which the evaporation was completed. The reason therefor is considered that the (cyclohexadiene)tricarbonylruthenium did not evaporate completely and formed a partially decomposed product, and the product was combusted and evaporated. Specifically, in the case of (cyclohexadiene)tricarbonylruthenium, this may be decomposed even in an evaporation temperature range, and this indicates that the ruthenium complex is partially decomposed depending on the setting of the vaporization temperature of the raw material in the case when the ruthenium complex is used as a raw material for chemical deposition. This makes the presetting of the film formation conditions severe. On the other hand, it is understood that no decomposition product was generated at the completion of the evaporation in the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium of this embodiment, and thus the evaporation was stably conducted.
Secondly, the results of the measurements of the vapor pressure and melting point of the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium are shown in the following table.
TABLE 2
Melting
Decomposition
point
Vapor pressure
temperature
The present
<−20° C.
2.25 Torr (at 50° C.)
>140° C.
embodiment
(Ru(CF 3 CHD)
(CO) 3 )
Comparative
20° C.
0.3 Torr (at 55° C.)
≈120° C.
Example
(Ru(CHD) (CO) 3 )
* The decomposition temperatures are described as values expected from the above-mentioned TG-DTA
≈
From the table, the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium of this embodiment can maintain a liquid state at from the melting point thereof to an ordinary temperature. Furthermore, the vapor pressure is sufficiently high. The (cyclohexadiene)tricarbonylruthenium, which is a conventional art, has a higher melting point and a lower vapor pressure than those of this embodiment. This is considered to be due to that the substituents were introduced in the cyclohexadiene and fluoroalkyl groups were selected as the substituents.
Secondly, using the (trifluoromethyl-cyclohexadiene)tricarbonylruthenium of this embodiment as a raw material for chemical deposition, a test for film formation of a ruthenium thin film was conducted. As a film formation apparatus, a cold wall type CVD apparatus in which only a substrate stage in a chamber is heated was used. A carrier gas for transferring a vapor of the raw material compound onto a substrate is controlled to be a predetermined flow amount by a mass flow controller. As the substrate for forming a ruthenium thin film, a Si wafer on which a SiO 2 coating had been formed in advance by thermal oxidation was used. The other film formation conditions are as follows.
Raw material heating temperature: 70° C. Substrate heating temperature: 175° C. Carrier gas (argon) flow amount: 10 sccm Reaction gas (oxygen) flow amount: 2 sccm Reaction chamber pressure: 50 Pa Film formation time: 20 minutes
When the film formation test was conducted under the above-mentioned conditions, a ruthenium film having metallic gloss was formed. The SEM photograph for this substrate is shown in FIG. 3 , and homogeneous thin films were formed on the upper parts and lower parts of the pores. It was confirmed from this result that a raw material for chemical deposition formed of (trifluoromethyl-cyclohexadiene)tricarbonylruthenium is useful for the formation of a high quality thin film.
Second Embodiment
In this embodiment, (pentafluoroethyl-cyclohexadiene)tricarbonylruthenium having carbonyl groups and a pentafluoroethyl derivative of cyclohexadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 93.9 g of pentafluoroethyl-cyclohexadiene was dissolved. The pentafluoroethyl-cyclohexadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 85° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (pentafluoroethyl-cyclohexadiene)tricarbonylruthenium.
The yield amount of the (pentafluoroethyl-cyclohexadiene)tricarbonylruthenium obtained by the above-mentioned step was 76.3 g, the yield thereof was 84%, and the melting point was −20° C. or less.
Third Embodiment
In this embodiment, (bistrifluoromethyl-cyclohexadiene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of cyclohexadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 102.4 g of bistrifluoromethyl-cyclohexadiene was further dissolved. The bistrifluoromethyl-cyclohexadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 85° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (bistrifluoromethyl-cyclohexadiene)tricarbonylruthenium.
The yield amount of the (bistrifluoromethyl-cyclohexadiene)tricarbonylruthenium obtained by the above-mentioned step was 77.0 g, the yield thereof was 81%, and the melting point was −20° C. or less.
Fourth Embodiment
In this embodiment, (pentafluoroethyltrifluoromethyl-butadiene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of butadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 125.8 g of pentafluoroethyltrifluoromethylcyclohexadiene was dissolved. The pentafluoroethyltrifluoromethyl-butadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 80° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (pentafluoroethyltrifluoromethylcyclohexadiene)tricarbonylruthenium.
The yield amount of the (pentafluoroethyltrifluoromethylcyclohexadiene)tricarbonylruthenium obtained by the above-mentioned step was 84.5 g, the yield thereof was 79%, and the melting point was −20° C. or less.
Fifth Embodiment
In this embodiment, (pentafluoroethyl-butadiene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of butadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 57.9 g of trifluoromethyl-butadiene was further dissolved. The trifluoromethyl-butadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 80° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (trifluoromethyl-butadiene)tricarbonylruthenium.
The yield amount of the (trifluoromethyl-butadiene)tricarbonylruthenium obtained by the above-mentioned step was 59.7 g, the yield thereof was 82%, and the melting point was −20° C. or less.
Sixth Embodiment
In this embodiment, (pentafluoroethyl-butadiene)tricarbonylruthenium having carbonyl groups and a pentafluoroethyl derivative of butadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 81.6 g of pentafluoroethyl-butadiene was further dissolved. The pentafluoroethyl-butadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 80° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (pentafluoroethyl-butadiene)tricarbonylruthenium.
The yield amount of the (pentafluoroethyl-butadiene)tricarbonylruthenium obtained by the above-mentioned step was 66.9 g, the yield thereof was 79%, and the melting point was −20° C. or less.
Seventh Embodiment
In this embodiment, (pentafluoroethyltrifluoromethyl-butadiene)tricarbonylruthenium having carbonyl groups and a pentafluoroethyltrifluoromethyl derivative of butadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 113.5 g of pentafluoroethyltrifluoromethyl-butadiene was further dissolved. The pentafluoroethyltrifluoromethyl-butadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 80° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (pentafluoroethyltrifluoromethyl-butadiene)tricarbonylruthenium.
The yield amount of the (pentafluoroethyltrifluoromethyl-butadiene)tricarbonylruthenium obtained by the above-mentioned step was 79.6 g, the yield thereof was 79%, and the melting point was −20° C. or less.
Eighth Embodiment
In this embodiment, (bistrifluoromethyl-butadiene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of butadiene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 90.1 g of bistrifluoromethyl-butadiene was further dissolved. The bistrifluoromethyl-butadiene at this time is in a twice equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 80° C. for 20 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by a silica gel column containing hexane as a developing solvent to collect (bistrifluoromethyl-butadiene)tricarbonylruthenium.
The yield amount of the (bistrifluoromethyl-butadiene)tricarbonylruthenium obtained by the above-mentioned step was 72.9 g, the yield thereof was 82%, and the melting point was −20° C. or less.
Ninth Embodiment
In this embodiment, (trifluoromethyl-cyclooctatetraene)tricarbonylruthenium having carbonyl groups and a trifluoromethyl derivative of cyclooctatetraene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 102.1 g of trifluoromethyl-cyclooctatetraene was further dissolved. The trifluoromethyl-cyclooctatetraene at this time is in a 2.5-fold equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 85° C. for 48 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by an alumina column containing hexane as a developing solvent to collect (trifluoromethyl-cyclooctatetraene)tricarbonylruthenium.
The yield amount of the (trifluoromethyl-cyclooctatetraene)tricarbonylruthenium obtained by the above-mentioned step was 64.4 g, the yield thereof was 76%, and the melting point was −20° C. or less.
Tenth Embodiment
In this embodiment, (pentafluoroethyl-cyclooctatetraene)tricarbonylruthenium having carbonyl groups and a pentafluoroethyl derivative of cyclooctatetraene as ligands (the following formula) was produced.
50.5 g of DCR was dissolved in 1.0 L of hexane as a solvent in a three-necked flask, and 142.4 g of pentafluoroethyl-cyclooctatetraene was further dissolved. The pentafluoroethyl-cyclooctatetraene at this time is in a 2.5-fold equivalent amount (molar ratio) with respect to the DCR. This reaction liquid was then refluxed at 85° C. for 48 hours. After the reflux, the reaction liquid was distilled off under a reduced pressure, and purification was conducted by an alumina column containing hexane as a developing solvent to collect (pentafluoroethyl-cyclooctatetraene)tricarbonylruthenium.
The yield amount of the (pentafluoroethyl-cyclooctatetraene)tricarbonylruthenium obtained by the above-mentioned step was 80.6 g, the yield thereof was 80%, and the melting point was −20° C. or less.
Each of the ruthenium complexes produced in the above-mentioned second to tenth embodiments was able to be produced by a polyene derivative in a twice equivalent amount with respect to the DCR, and was able to be synthesized by only a thermal reaction. Furthermore, either of the ruthenium complexes had a sufficient yield. Since these ruthenium complexes have a low melting point and maintain a liquid state at an ordinary temperature, they are preferable as raw materials for chemical deposition.
INDUSTRIAL APPLICABILITY
Since the ruthenium complex that constitutes the raw material for chemical deposition according to the present invention has a high vapor pressure and a moderate decomposition temperature, a high-precision ruthenium/ruthenium compound platinum thin film can be formed at a low temperature. The raw material for chemical deposition according to the present invention can be produced at a relatively low cost, and thus can also contribute to the decrease in cost for the formation of a thin film.
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The present invention provides a raw material, formed of a ruthenium complex, for producing a ruthenium thin film or a ruthenium compound thin film by a chemical deposition method, wherein the ruthenium complex is a ruthenium complex represented by the following formula, in which carbonyl groups and a fluoroalkyl derivative of a polyene are coordinated to ruthenium. The present invention provides a raw material for chemical deposition having a preferable decomposition temperature, and the production cost therefor is low:
( n R-L)Ru(CO) 3 [Chemical Formula 1]
wherein L is a polyene having a carbon number of from 4 to 8 and 2 to 4 double bonds, wherein the polyene L has n (n≧1) pieces of substituents Rs, wherein the substituents Rs are each a fluoroalkyl group having a carbon number of from 1 to 6 and a fluorine number of from 1 to 13, and in the case when the polyene L has two or more (n≧2) of the substituents Rs, the carbon numbers and the fluorine numbers of the substituents Rs may be different in the same molecule.
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RELATED APPLICATIONS
[0001] Applicant claims the benefit of provisional application Ser. No. 61/214,687, filed Apr. 28, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to fencing systems, and more particularly, to a reinforced equine fence system which allows for greater spans between vertical support posts and which includes electrically charged spirally embedded wire as a safety measure to deter equine contact and enhance the life of the fencing system.
[0004] 2. Description of the Prior Art
[0005] Equine fencing systems have been in use since man first domesticated the horse. Fencing systems are used to enclose corrals, and grazing areas, and fencing systems are also used to direct the flow of equine traffic.
[0006] Initially fencing systems were made of wood and timber and wood and timber remain in wide spread use. However, wood and timber fences are high maintenance since there is deterioration due to weather factors and the concommitment requirement of painting and restoring damaged rails.
[0007] Applicant has used his expertise in commercial and residential railing systems to develop an equine fencing system utilizing post and rails fabricated from high density polyethylene (HDPE) which can be formed with a desired pigmentation and can be utilized for horizontal fencing styles ranging from two to four horizontal rails or more. Fabrication from HDPE eliminates much of the high maintenance of the old wood and timber fence systems, and allows a spirally embedded electrical wire to be embedded in the fencing system which further prevents deterioration or damage to the fencing system from the horses by limiting or discouraging their contact with the fencing system, yet allows the facile replacement of rails should they be displaced by contact.
[0008] Another improvement of Applicant's fencing system over that of the prior art is the ability of Applicant's fencing system to span greater horizontal lengths without appreciable sagging. The typical distance between posts in a two, three, or four rail fencing system, would normally be 4′6″. This is based upon the weight of the horizontal rails, strength of the posts, and the desired rigidity to be maintained on the fencing system between the posts when contacted by a horse. It would be desirable and cost effective if the distance between posts could be lengthened such that the length of rail could be increased. This would decrease the number of posts and further decrease the number of footings required for each post. Applicant has developed a reinforcing insert for use in the railing system which allows the distance between posts to increase to 8′ while still maintaining the integrity and desired rigidity of the horizontal rails.
OBJECTS OF THE INVENTION
[0009] An object of the present invention is to provide for a novel equine fence system fabricated from high density polyethylene and which incorporates rail stiffeners so as to increase the allowable distance between posts for support of the horizontal rails.
[0010] A still further object of the present invention is to provide for a novel equine fence system fabricated of high density polyethylene which incorporates a rail stiffener system for allowance of greater distance between the vertical posts and which incorporates a spirally embedded electrical wire which decreases the likelihood of damage or breakage by discouraging the horse from contact with the fencing system.
[0011] Another object of the present invention is to provide for a novel equine fence system which incorporates a rail stiffener which allows the horizontal rails to span a greater distance, thereby requiring less vertical posts, and thus encouraging a cost and materials savings.
[0012] Another object of the present invention is to provide for a novel equine fence system which incorporates an acceptable level of flex to the fence rails wherein all of the connections of one fence member to another will detach under sufficient pressure, but is easily replaceable or repaired. It therefore minimizes potential injury to the horse and property.
[0013] A still further object of the present invention is to provide for a novel equine fence system in which a spiral electrically conductive wire is embedded just below the surface of the fence rail which eliminates scratching the horse, and will discourage the horse from trying to chew, rub or graze through the fence, the electrical conductive wire being charged by a voltage sufficient to discourage a horse from contacting the fence, this voltage supplied by direct current or solar panel.
SUMMARY OF THE INVENTION
[0014] An equine fence system fabricated of high density polyethylene having a plurality of vertical support posts embedded in the ground, there being a plurality of horizontal rail members extending between adjacent vertical posts, the horizontal rail members having a spiral electrically conductive wire embedded just below the surface of the horizontal rail to discourage contact between the horse and rail, the horizontal rails having an additional stiffener and support member longitudinally positioned within the horizontal rail to provide additional support for the horizontal rail and permit the use of longer horizontal rails therefore increasing the distance between vertical posts and reducing costs and maintenance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other objects of the present invention will become apparent, particularly when taken in light of the following illustrations wherein:
[0016] FIG. 1 is a planar front view of a section of an equine fence of the present invention illustrating a three rail system;
[0017] FIG. 2 is a perspective sectional view of area A of FIG. 1 illustrating the construction of the horizontal rail utilized in the system;
[0018] FIG. 3 is a partial side cutaway view of a rail illustrating a spring clip connector for the horizontal rails;
[0019] FIG. 4 is an end view of a horizontal rail with the stiffener positioned therein;
[0020] FIG. 5 is a perspective partially assembled view of a horizontal rail with the stiffener partially extended; and
[0021] FIG. 6 is a planar front view illustrating the assembly of the equine fence.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is a front view of a portion of an equine fence system of the present invention fabricated out of high density polyethylene (HDPE). The equine fence 10 comprises a plurality of vertical posts 12 in spaced apart relationship, the lower portion 14 of the vertical post embedded into the ground and in most instances, into a footing 16 . Vertical post 12 is formed with a plurality of apertures 18 for the slidable receipt of a plurality of horizontal railing members 20 . In FIG. 1 , the equine fence 10 is illustrated with three horizontal railing members 20 , however, it will be understood by one of ordinary skill in the art that the number of horizontal railing members 20 may vary depending upon the height of the fence.
[0023] The horizontal railing members 20 are slidably received within the apertures 18 formed in the vertical posts 12 and snap fit therein as more fully described hereafter. For straight sections of the equine railing system 10 , the apertures 18 in a particular vertical post 12 would be in 180° relationship with each other so that a horizontal rail member 20 could be secured to the aperture on one side of the vertical post 12 and a separate horizontal rail member 20 would be slidably inserted into the corresponding aperture 18 positioned in 180° relationship with the first aperture. In those situations where the equine railing fence 10 is required to angle or turn at 90°, the respective apertures 18 in the vertical post 12 would be angularly positioned so as to accommodate the turn angle.
[0024] FIG. 2 is a perspective view of a portion of a horizontal railing member 20 from area A of FIG. 1 . The railing member 20 is fabricated from HDPE and is tubular in shape having in a preferred embodiment, a 3″ outer diameter, with a wall thickness of 0.170 inches. The state of the current art dictates that the vertical posts 12 are spaced approximately 5′5″ apart on center. The horizontal rail members 20 may be fabricated to fit between adjacent vertical posts 12 or maybe of a longer length so as to span two, three, or possibly four vertical posts before an end of one horizontal rail member is juxtaposed to an end of another abutting horizontal railing member 20 . In the preferred embodiment the ends of horizontal rail members 20 juxtapose adjacent horizontal rail members within the circumference of vertical posts 12 .
[0025] FIG. 2 also illustrates the spiral embedded electrical wire 30 which is positioned in the horizontal rail members 20 prior to their positioning between the vertical posts 12 . Depending upon the number of horizontal rails, the owner may chose to spirally embed the electrical wire 30 in all of the horizontal rails 20 , or only select horizontal rails. The electrical wire 30 spirally embedded in a horizontal rail is electrically connected to the electrically embedded spiral wire in an adjacent horizontal rail 20 by means of a flexible electrical connection 28 , commonly referred to as a pigtail and illustrated in FIG. 6 , which is positioned within the vertical post 12 where adjacent horizontal rails 20 abut.
[0026] The horizontal rail members 20 and the spirally embedded electrical wire 30 are fabricated in the following manner. The horizontal rail member 20 is first extruded from high density polyethylene into an extended tubular form and is allowed to set before entering an embedding station. The embedding station comprises a coil or spool of electrical conductive wire, the unspooled portion being under tension. Still further, the wire is electrically heated. The temperature of the wire is sufficient that as the wire is spirally contacted to the outer circumferential surface of the horizontal railing member 20 as it passes through the embedding station, the heat of the wire causes the wire to melt a spiral groove in the outer circumferential surface of the horizontal rail member such that the electrical wire becomes spirally embedded over the length of the horizontal rail member. The depth of the embedded electrical wire is crucial in that if it is embedded too deeply, the melted high density polyethylene will reset and completely cover the electrical wire, which would then prevent it from performing as required. The correct depth is achieved by the speed of the horizontal rail member 20 moving through the embedding station and the speed and the temperature of the electrical wire 36 as it spirals about the horizontal rail member 20 .
[0027] Once the horizontal rail member has had the spirally embedded electrical wire 30 positioned on its circumferential surface, the horizontal rail member 20 can be cut to the desired length. Due to the fact that the electrically embedded wire 30 is spirally bound about the outer circumferential surface of horizontal rail member 20 , regardless of the length to which the horizontal rail member 20 is cut, each end will have a terminus of a spirally embedded electrical wire 30 .
[0028] The horizontal rail members 20 are maintained in position relative to vertical posts 12 by means of spring clips 22 . Spring clip 22 as illustrated in FIG. 3 is a U-shaped polymer clip having two outwardly extending fingers 24 . Spring clip 22 is inserted into the ends of each horizontal rail member 20 such that the extending fingers 24 project through two opposing apertures 23 in the circumferential side wall of the horizontal rail member 20 .
[0029] The extending fingers 24 are beveled 25 such that the spring pin is compressed when the end of the horizontal rail member 20 is inserted into the vertical post 12 . Extending fingers 24 compress into their respective apertures until they have passed through the circumferential side wall of the vertical post 12 . Spring clip 22 then causes the extending fingers 24 to biasly extend back through the apertures in the circumferential side wall of horizontal rail member 20 and thus engage the interior circumferential surface of vertical post 12 . Each end of a horizontal rail member 20 is so secured to vertical post 12 .
[0030] Prior to the ends of horizontal rail members 20 being inserted into the vertical post 12 and secured by the spring clips 22 as previously described, the flexible electrical connection 28 (pigtail) is secured to the terminus of the spirally embedded electrical wire 30 in one of the juxtaposed horizontal rail members. This flexible connector 28 is then extended through the apertures in vertical post 12 so that it can be electrically connected to the terminus of the spirally embedded electrical wire 30 in the adjacent or juxtaposed horizontal rail member 20 . This continues a circuit between juxtaposed horizontal rail members. Rail members so electrically connected can then be secured to the vertical post by means of the spring clips 22 as previously described. A power source 21 in the form of a solar cell or conventional power source would be converted to the embedded electrical wire 30 with appropriate voltage and/or amperage control to electrify the system. (See FIG. 6 ).
[0031] FIG. 4 is an end view of a horizontal rail 20 of the current equine railing system with a stiffener positioned therein, and FIG. 5 is a perspective partially assembled view of the horizontal rail with the stiffener partially extended. The horizontal rail 20 fabricated of high density polyethylene (HDPE) has a outer diameter of three inches and a wall thickness of 0.140 inches. The rail stiffener 40 which is slidably receivable within the horizontal rail member 20 is square in shape having two inch sides 42 , and a thickness of 0.125 inches. Since the stiffener 40 is positioned within the tubular horizontal rail member 20 , and protected from sunlight and the ambient weather, the stiffener can be fabricated from PVC or other suitable lightweight polymer. The corners of horizontal rail stiffener 40 are rounded with a radius of 0.156 inches. FIG. 3 illustrates the stiffener 40 within the tubular horizontal rail 20 whereby once slidably inserted, the four rounded corners 44 of the stiffener contact the inner wall 22 of the horizontal rail member 20 at four distinct points which would extend along the length of the rail member 20 . The stiffener 40 allows the horizontal rail member 20 to span a larger distance between vertical posts 12 without sagging and provides a stiffener to the horizontal rail member 20 , but does not interfere with the ability of the horizontal rail member 20 to flex under load, such as if a horse were to bump into the fence.
[0032] Any dimensions relating to diameter, circumference, or length mentioned in the specification are for explanatory purposes only. It will be recognized by those of ordinary skill in the art that the diameters and circumferences and lengths may vary in a particular fencing system with respect to posts and rails. Therefore any dimensions cited should be treated as exemplary with the changes in size being concomitant with larger or smaller internal stiffeners and apertures for receipt of rails.
[0033] Therefore, while the present invention has been disclosed with respect to the preferred embodiments thereof, it will be recognized by those of ordinary skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore manifestly intended that the invention be limited only by the claims and the equivalence thereof.
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An equine fence system fabricated of high density polyethylene having a plurality of vertical support posts embedded in the ground, there being a plurality of horizontal rail members extending between adjacent vertical posts, the horizontal rail members having a spiral electrically conductive wire embedded just below the surface of the horizontal rail to discourage contact between the horse and rail, the horizontal rails having an additional stiffener and support member longitudinally positioned within the horizontal rail to provide additional support for the horizontal rail and permit the use of longer horizontal rails therefore increasing the distance between vertical posts and reducing costs and maintenance.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority (under 35 USC 119) of UK Patent Application No. 1113777.5, filed 10 Aug. 2011.
BACKGROUND
[0002] This invention relates to a motor control system, a method of operating a motor control system, a tape drive including a motor control system, a method of operating such a tape drive and a printing apparatus including such a tape drive.
[0003] Such printing apparatus includes drive apparatus for moving the tape relative to the printhead, to present fresh tape, from which pixels of ink are yet to be removed, to the printhead, such that successive printing operations can be carried out. It has long been known to provide tape drives which include two spool supports, one of which supports a supply spool on which unused tape is initially wound, and the other of which supports a take-up spool, onto which the tape is wound after it has been used. Tape extends between the spools in a tape path. Each of the spool supports, and hence each of the spools of tape, is drivable by a respective motor.
[0004] It is known to provide thermal transfer printing apparatus in two different configurations. In the first, so called “intermittent” configuration, the substrate to be printed and the tape are held stationary during a printing operation, whilst the printhead is moved across the area of the substrate to be printed. Once the printing operation is complete, the printhead is lifted away from the tape, and the tape is advanced to present a fresh region of tape to the printhead for the next printing operation.
[0005] In the second, so called “continuous” configuration, the substrate to be printed moves substantially continuously and the tape is accelerated to match the speed of the tape before the printhead is brought into thermal contact with the tape and the printing operation is carried out. In this configuration, the printhead is maintained generally stationary during each printing operation.
[0006] It is known to interlace images, such that a previously used region of tape is reused, but in the second and/or subsequent printing operations, different pixels of ink are removed from the tape to create an image. In the case of a printing apparatus in continuous configuration, it is also preferable to accurately control the speed of the tape, to ensure that it matches the speed of the substrate. A typical thermal transfer printer operates with a substrate that advances at linear speeds between approximately 0.01 metre per second and approximately 2 metres per second. Typical substrate accelerations are up to approximately 12 metres per second per second.
[0007] Tape drives of various types have been proposed, for example a tape drive which includes a stepper motor for driving a take up spool so as to pull tape through along a tape path between a supply spool and the take up spool. Such a tape drive also includes a mechanical clutch for setting and maintaining the tension in the tape. Such tape drives are often mechanically complex and regular maintenance of the clutch is typically required. Furthermore, since the supply spool is operated at a fixed torque, the tension in the tape varies as the diameter of the supply spool varies over time.
[0008] Another example of a known tape drive is one in which a take up spool and a supply spool are rotated by respective stepper motors. The stepper motors are driven in a co-ordinated manner to transfer the tape from the supply spool to the take up spool and to accurately position the tape adjacent the printhead, whilst maintaining the tension in the tape. Various methods of determining and maintaining the tension of the tape have been proposed. Such methods typically require the measured tension in the tape to be compared with the desired tension, and for a correction to be applied. Therefore, such methods often incur a delay of at least one printing operation between the tension in the tape falling outside an acceptable range and the correction being applied.
[0009] A further example of a known tape drive includes a pressure roller in the tape path, which is driven by a motor. The roller directly controls the speed and position of the tape. The tape spools are driven through a mechanical clutch which maintains the tape tension between acceptable limits. Such tape drives are often mechanically complex. The tape drive is typically uni-directional and this tends to cause tape wastage.
[0010] A still further example of a known tape drive is one in which two DC motors are used to drive the spools of tape (as described in FR 2783459, for example). Both of the motors operate in torque control mode, and a roller which is positioned near to the printhead is used to determine the movement of the tape along the tape path. Such a tape drive includes rollers on the inked side of the tape which can require regular maintenance. Furthermore, desired printing speeds and tape accelerations are increasing, leading to difficulties in operating such a drive.
SUMMARY
[0011] This invention relates to a motor control system, a method of operating a motor control system, a tape drive including a motor control system, a method of operating such a tape drive and a printing apparatus including such a tape drive.
[0012] The invention can be particularly useful in relation to a printing apparatus which utilises a printing tape or “ribbon” which includes a web carrying marking medium, e.g. ink, and a printhead which, in use, removes marking medium from selected areas of the web to transfer the marking medium to a substrate to form an image, such as a picture or text.
[0013] More particularly, but not exclusively, the invention relates to a so called thermal transfer printing apparatus in which the printhead includes a plurality of thermal heating elements which are selectively energisable by a controller during printing to warm and soften pixels of ink from the tape and to transfer such pixels to the substrate. The printhead presses the tape against the substrate such that the pixels of ink contact the substrate before the web of the tape is peeled away, thus transferring the pixels of ink from the tape to the substrate.
[0014] The tape used in thermal transfer printers is thin. Therefore it is important to ensure that the tension in the tape extending between the two spools is maintained at a suitable value or within a suitable range of tensions, in particular to enable the web to peel cleanly away from the heated ink. Too much tension in the tape is likely to lead to the tape being deformed or broken, whilst too little tension will inhibit the correct operation of the device. A slack tape is likely to affect print quality.
[0015] In order to avoid wasting ink, whilst maintaining acceptable print quality, it is advantageous to be able accurately to control the movement of the tape, so as to position the next portion of tape to be used directly adjacent a portion of the tape from which the ink has previously been removed. It is desirable for a spacing between adjacent regions of tape from which pixels are removed to create an image, to be better than 1 mm. It is also important to ensure that the regions of tape from which ink is removed during successive printing operations do not overlap, so that the printhead does not attempt to remove ink from the same region of the tape more than once.
[0016] In accordance with the present invention, there is provided a motor control system including a motor having an associated rotary position encoder, and a controller for controlling the operation of the motor, wherein the motor is switchable between a first control mode wherein position is a dominant control parameter to a second control mode where torque is the dominant control parameter. The motor may be a brushless DC motor or other functionally comparable motor. This invention has been developed using brushless DC motors. These motors are known by other names, for example, AC servo motors. The invention is also applicable to motors known as Switched Reluctance motors (both with and without permanent magnets). These motors are all controlled by the use of a software controlled system which generates a rotating magnetic field, and as such are functionally comparable with one another.
[0017] A measurement of the velocity of the motor may be fed back to the controller and used to determine an output of the controller which is received by the motor to control the movement of the motor. When the motor is in the first control mode, the controller may receive an input relating to a demanded position of the motor and an actual position of the motor, and may determine a change in position which is required to be carried out by the motor. In addition, the controller may use the change in position, the velocity of the motor and a torque bias value, to determine the output of the controller which controls the movement of the motor.
[0018] When the motor is in the second control mode, the controller may receive an input relating to a torque bias value which is used to determine an output of the controller which controls movement of the motor. The controller may receive an input relating to the velocity of the motor which is used in conjunction with the torque bias value to determine the output of the controller which controls movement of the motor.
[0019] The motor control system may include a pair of motors, each having an associated sensor and the controller controlling operation of both of the motors such that at least one is switchable between the first control mode and the second control mode. Each of the motors may be a brushless DC motor or other functionally comparable motor. Each sensor may enable the controller to determine the position and velocity of a rotor of the respective motor. Moreover, switching between the first control mode and the second control mode may be a smooth transition.
[0020] According to a second aspect of the invention, there is provided a method of operating a motor control system according to the first aspect of the invention, wherein the method may include providing an input to the controller relating to a torque bias, to determine the motor torque developed by the motor. The method may include using a user input to adjust the ratio of each control mode of the motor.
[0021] The method may include testing an accuracy of the control of the motor. The control system may be used to control a pair of motors, and the method may include determining a ratio of torques applied to the motors. The method may include determining a number of steps moved by the motor as it moves between a target position and a rest position.
[0022] According to a third aspect of the invention, there is provided a tape drive including a pair of tape spool supports, upon one of which a supply spool is mountable and upon a second one of which a take up spool is mountable, each tape spool support being drivable by a respective motor which has an associated sensor, the tape drive further including a controller to control each of the motors, wherein at least one of the motors is switchable between a first control mode wherein position is a dominant control parameter and a second control mode wherein torque is the dominant control parameter. Both of the motors may be switchable between the first control mode and the second control mode. Both motors may be drivable in the first control mode during movement of tape between the tape spool supports, and wherein at least one of the motors is switchable from the first control mode to the second control mode when the movement of the tape has been completed, and from the second control mode to the first control mode when tape movement is to be carried out. Moreover, a transition of the control mode of the motor between the first control mode and the second control mode may be smooth.
[0023] According to a fourth aspect of the invention, there is provided a method of operating a tape drive according to the third aspect of the invention, the method including maintaining tension in tape extending between the two spools, when the tape is substantially stationary, by operating one motor in the first control mode whilst operating the other motor in the second control mode. The method may include switching the motor which was in the second control mode whilst the tape was stationary into the first control mode in order to transfer tape between the spools.
[0024] The method may include determining estimated values of diameters of each of the spools and updating the estimated values of the diameters during use of the tape drive. The method may include testing an accuracy of the control of the motors by determining a ratio of torques applied to the motors and comparing the ratio of the torques with a ratio of estimated diameters of the two spools. The method may include testing an accuracy of the control of the motors by monitoring a number of steps taken by a motor between a target position and a rest position. The method may include driving the motors so as to release tension from tape extending between the spools before power is removed from the motors.
[0025] According to a fifth aspect of the invention, there is provided printing apparatus including a tape drive according to the third aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0027] FIG. 1 is an illustrative view of part of a thermal printing apparatus including a motor control system according to the present invention; and
[0028] FIG. 2 is an illustrative view of a feedback circuit of the motor control system.
DETAILED DESCRIPTION
[0029] Referring to FIG. 1 , there is shown a part of a printing apparatus 10 . The printing apparatus 10 includes a tape drive shown generally at 11 .
[0030] The printing apparatus includes a housing 13 , in or on which is mounted a first spool support 12 and a second spool support 14 , which form part of the tape drive 11 . A spool of tape 15 , 17 , for example inked printer ribbon, is mountable on each of the supports 12 , 14 . The spool supports 12 , 14 are spaced laterally from one another. The printing apparatus 10 also includes a printhead 19 for transferring ink from the tape to a substrate 21 which is entrained around a roller 23 adjacent the printhead 19 . Depending upon the configuration of the printer, the substrate 21 may be positioned adjacent the printhead 19 on a platen, rather than a roller.
[0031] Each of the spool supports 12 , 14 is independently drivable by a respective motor 16 , 18 . Each of the motors 16 , 18 is a brushless DC motor. Each of the spool supports 12 , 14 is rotatable clockwise and anti-clockwise by means of its respective motor 16 , 18 . Each motor 16 , 18 is electrically connected to a controller 24 via a sensor 20 , 22 . This sensor is typically a rotary encoder although it will be appreciated that other technologies are perfectly acceptable. The controller 24 is operable to control the mode of operation of each of the motors 16 , 18 and the amount of drive provided by each of the motors 16 , 18 . Each sensor 20 , 22 enables the controller 24 to determine the angular position and rotational speed of a rotor of each respective motor 16 , 18 . Information relating to the current drawn by each motor 16 , 18 is provided to the controller 24 . The motors 16 , 18 , the sensors 20 , 22 and the controller 24 all form part of a motor control system 25 .
[0032] The controller 24 receives inputs relating to a demanded position of each motor 16 , 18 to advance the tape to a required position, the actual position of the motor 16 , 18 , the measured velocity of each motor 16 , 18 , the current drawn by the motor 16 , 18 , and a torque bias T B required by the motor at a given point in time. The purpose of the torque bias will be explained in more detail below. The position of the controller 24 relative to the remainder of the printing apparatus 10 is irrelevant for the purposes of the present invention.
[0033] In use, a supply spool 17 , upon which unused tape is wound, is mounted on the spool support 14 , and a take up spool 15 , upon which used tape is wound, is mounted on the spool support 12 . The tape generally advances in a tape path between the supply spool 17 towards the take up spool 15 . The tape is guided in the tape path between the spools 15 , 17 adjacent the printhead 19 by guide members 26 .
[0034] The tape drive 11 should be calibrated before printing operations commence. Such calibration is generally required when the printing apparatus 10 is switched on, and when the spools of tape 15 , 17 are replaced. The calibration process includes determining an initial estimate of the diameters of each of the spools of tape 15 , 17 mounted on the spool supports 12 , 14 . An example of a suitable method of obtaining such an estimate is described in detail in the applicant's patent GB2310405. As tape passes from one spool to the other, for example from the supply spool 15 to the take up spool 17 , it passes over a roller of known diameter. The roller is preferably one of the guide members 26 . Tape is drawn from the supply spool 17 , with the motor 16 which drives the take-up spool support 12 operating in position control mode. The motor 18 which drives the supply spool support 14 operates in torque control mode to deliver a predetermined torque.
[0035] Following the calibration process, the motor control system 25 maintains and updates values for the diameters of the spools 15 , 17 by monitoring the amount of tape transferred from the supply spool to the take-up spool. The controller 24 takes into account the thickness of the tape to compute an expected change in the diameters of the spools 15 , 17 over a period of time. This technique relies on the tension in the tape being kept substantially constant during printing operations and advancement of the tape between the spools 15 , 17 .
[0036] When the tape is at rest, the motor control system 25 maintains the desired tape tension by operating one motor, for example the supply spool motor 18 , in a first control mode, in which position is a dominant control parameter. This first control mode will be referred to herein as “position control mode”. The other motor, for example the take up spool motor 16 , is operated in a second control mode, in which a the dominant control parameter is torque. The second control mode will be referred to herein as “torque control mode”.
[0037] Therefore the tape drive 13 operates in a similar fashion to one in which one of the motors 16 , 18 is a stepper motor and the other motor 16 , 18 is a DC motor. One motor 18 ensures that the absolute position of the tape relative to the printhead is accurately controlled, whilst the other motor 16 maintains the tension in the tape at the desired predetermined value.
[0038] A demanded position P D of the motor 18 is received by an S-curve generator 28 , an output of which is used, along with an actual position P A of the motor 18 in an algorithm, preferably a PID (Proportional-Integral-Derivative) algorithm, applied by an electronic filter 29 to determine the change in position required to be carried out by the motor 18 . An actual velocity V A of the motor is input to a second electronic filter 31 , which performs an algorithm, again preferably a PID algorithm, and an output of the second electronic filter 31 is used in conjunction with an output of the first electronic filter 29 , relating to the change in position of the motor 18 , to determine a demanded torque T D to be provided by the motor 18 . A demanded torque T D and the amount of current A drawn by the motor 18 are fed back to a torque controller 30 to provide a control output to the motor 18 . Although the algorithms implemented by the filters 29 , 31 are described as being PID algorithms, it will be appreciated that any Linear Time Invariant filter function may be used.
[0039] The motor 16 being operated in torque control mode does not use inputs relating to demanded position P D or actual position P A of the motor 16 . The inputs relating to actual velocity V A may also be disregarded. The torque controller 30 receives a torque demand T D based only on the torque bias T B , and optionally upon the actual velocity V A of the motor 16 . The current A of the motor 16 may also be fed back to the torque controller 30 to generate a control output for the motor 16 , such as the BLDC (Brushless Direct Current) motor shown in FIG. 2 .
[0040] When the tape is required to be advanced between the spools 15 , 17 , the controller 24 causes both of the motors 16 , 18 to operate in position control mode. The transition of the motor 16 , 18 which was previously operated in torque control mode into position control mode is smooth. This transition from torque control mode to position control mode is carried out by gradually reducing the torque bias T B to a nominal value, which may be zero.
[0041] During tape advance, the two motors 16 , 18 advance the tape accurately along the tape path past the printhead 19 , using the values of the diameters of the spools 15 , 17 and a co-ordinated moving target position. The co-ordinated moving target position is arrived at by the control system 25 determining the desired position of the tape at a point in time, and the controller 24 controls the motors 16 , 18 to achieve this desired position of the tape.
[0042] During tape advance, it is desirable for the amount of tape fed into the tape path from the supply spool 17 to be equal to the amount of tape taken up by the take up spool 15 , in order to maintain the tape tension substantially constant. However, this is difficult to achieve in known tape drives because disturbances of the tape which occur during printing operations, and the fact that the spools 15 , 17 are not perfectly cylindrical, mean that the control of the motors 16 , 18 is based upon inaccurate estimates, and thus the tension is unlikely to be kept as near to constant as desired. In the present invention, the smooth transition of the take up motor from position control mode to torque control mode prevents the accumulation of such errors increasing long term drift in the ribbon tension.
[0043] Once the advancement of the tape has been completed, one of the spool motors 16 , 18 , for example the take up spool motor 16 , smoothly transitions from position control mode to torque control mode, by increasing the torque bias T B relating to the motor 16 , whilst the other spool motor, for example the supply spool motor 18 , remains in position control mode. Gradually increasing the torque bias T B from zero during deceleration of the tape causes a smooth transition of the motor from position control mode to torque control mode, before the inputs relating to position P A , P D are disregarded. The other motor, in this case the supply spool motor 18 , remains in position control mode, however the value of torque bias T B applied to this motor may be adjusted, so as to compensate for the increase in torque which is likely to be caused as a result of switching the take up spool motor 16 into torque control mode. In practice, it may be possible to retain a constant torque bias T B irrespective of whether the motors 16 , 18 are stationary or in motion, however, the desired torque bias T B will be such that it causes the tension in the tape to remain substantially constant, by the two motors 16 , 18 applying equal and opposite forces on the tape.
[0044] The motor control system 25 is capable of testing the accuracy of its control of the advancement of the tape in two ways.
[0045] The first method of testing is to determine the ratio of the torques applied to the two motors 16 , 18 when the tape drive 11 is stationary. In such a situation, one motor 16 , 18 is stationary, whilst the other motor 16 , 18 supplies a torque so as to maintain its position, and to maintain the tension in the tape. The ratio of the torques should be the same as the ratio of the diameters of the spools 15 , 17 at that time.
[0046] The second method of testing is carried out as the tape drive 11 is completing a movement of the tape. As the take up spool motor 16 transitions from position control mode to torque control mode, the controller 24 monitors the angular position change of take up spool motor 16 between its expected target position and its rest position at the correct ribbon tension, using the sensor 20 . The angular position change that occurs together with the spool diameter gives a measure of the disturbances and errors in the position control of the motor 16 .
[0047] The operation of the control system 25 is iterative, in that it takes into account the results of the testing method(s) carried out over a number of tape advancements (printing cycles) to correct the estimate of the diameters of the spools 15 , 17 for future printing cycles.
[0048] The method of operation of the tape drive 11 described above retains the supply spool motor 18 in position control, as the supply spool 17 is more likely to be cylindrical than the take up spool, the tape on the supply spool 17 not having been unwound, and ink removed from it before being rewound on a different spool. Therefore this mode of operation is more likely to provide accurate positioning of the tape adjacent the printhead 19 . However, it will be appreciated that either spool motor 16 , 18 could be switched to torque control mode during tape advance.
[0049] When power is removed from the motors 16 , 18 , the control system 25 manages the tension of the tape in the tape path. If the tape is in tension when power is removed from the motors 16 , 18 , one or both of the spools 15 , 17 will be accelerated by the force exerted by the tension in the tape. Even when the tape is no longer in tension, each spool 15 , 17 which has been accelerated will continue to rotate owing to the momentum of the spool(s) 15 , 17 , and tape may spill from the printing apparatus 10 . Of course, this is undesirable, and unacceptable. To overcome this problem, the control system 25 operates at least one of the motors 16 , 18 , so as to enable a controlled release of tension from the tape, before power is removed from the motors 16 , 18 . Alternatively, a mechanical device may be used to inhibit or prevent the acceleration of the spools 15 , 17 upon removal of power from the motors 16 , 18 .
[0050] Whilst the invention has been described in relation to thermal printing apparatus, it will be appreciated that the motor control system may be utilised in relation to other devices or apparatus.
[0051] When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
[0052] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
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A motor control system includes a motor having an associated rotary position encoder, and a controller for controlling the operation of the motor, wherein the motor is switchable between a position control mode and a torque control mode.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Chinese Patent Application No. 200610075640.4 filed on Apr., 18, 2006, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to a telephone communication system and method for implementing the same, and particularly to a network-based voice over power lines (VoPL) system and methods.
[0004] 2. Description of the Related Art
[0005] In conventional land-line telephone system every telephone number occupies one channel of a telephone switch and each of the user circuits is an independent physical line. Regardless of whether a user uses the physical line to make a call, the physical line is always “occupied.” While this mode may guarantee communication and quality, it also squanders resources. Specifically, an enormous expense of establishing and maintaining end user lines is always a big part of operating expenditure. For the same reason, the layout and maintenance of user lines in telephone switching systems is a very complex and costly task in terms of difficulty, complexity and cost of engineering, and its expense often outweighs that of devices.
[0006] With the advent of novel communication technologies, various technical standards and protocols (notably, the H.323 protocol stack and the Session Initiation Protocol (SIP) stack which provide real-time video, audio and data communication services) are replacing a traditional fixed telephone and indeed solve certain practical problems. However, most novel layer protocols are all based on the Internet Protocol (IP) network, and require the existence of a broadband network. Although, after decades of development, the broadband network becomes increasingly popular, it still faces a same problem as the traditional telephone system, and the expense of laying out and maintaining broadband lines is enormous.
[0007] Indeed, there have been many improvements in the recent years, especially with the development of the power line carrier technique and launch of the home plug powerline specification (HomePlug). The HomePlug specification provides vital bandwidth of 14M, 85M, 200M, and so on, allowing for growth of communication applications over power lines.
SUMMARY OF THE INVENTION
[0008] An objective of the invention is to provide a user telephone communication system over a power line network, which is capable of utilizing existent power line network to implement user telephone communication, so as to decrease the expense of establishing and maintaining end user lines and of laying out and maintaining user lines in a user telephone switching system. Meanwhile, communication quality of the user telephone communication system of the invention may compete with the conventional telephone communication system.
[0009] It is another objective of the invention to provide an implementation method for a network-based voice over power lines (VoPL) telephone communication system which assures high-quality communication, and decreases the expense for layout and maintenance.
[0010] To achieve the above objectives, in accordance with one embodiment of the invention, provided is a network-based voice over power lines (VoPL) telephone communication system comprises a power line network, multiple clients and a server. The clients are respectively connected to the power line network for providing access for a user telephone, and/or for providing a user interface. The server comprises at least one power interface and one telephone interface connected to the power line network and to the clients via the power line network for handling calls and transferring calls from the clients. The clients comprise power line adapters and/or power line telephones. The power line adapter comprises at least one power interface and one telephone interface for inputting numbers and/or information via keypads, e.g., to make a call. The power line telephone comprises at least one power interface for inputting numbers and/or information via keypads, e.g., to make a call.
[0011] In certain classes of this embodiment, the server further comprises at least one wide area network (WAN) interface and/or at least one local area network (LAN) interface connected to the Internet.
[0012] In certain classes of this embodiment, the server is configured as a power line switch.
[0013] In certain classes of this embodiment, the power line adapter further comprises at least one LAN interface, and the power line switch further comprises at least one LAN interface.
[0014] In certain classes of this embodiment, the telephone interface is configured as a RJ11 interface, an E1 interface, a T1 interface, or an optical fiber interface.
[0015] In certain classes of this embodiment, the WAN interface is configured as a RJ45 interface or an optical fiber interface, and the LAN interface is configured as a RJ45 interface or an optical fiber interface.
[0016] In certain classes of this embodiment, the LAN interfaces of both the power line adapter and the power line telephone are configured as the RJ45 interface or a USB interface.
[0017] In other aspects the invention provides an implementation method for a power-line-network-based user telephone communication system, comprising: a) configuring a server to connect to the power line network, and the clients to connect to the power line network, the server connected to the clients via power line network, the server configured as a power line switch, and the clients respectively configured as a power line adapter and/or a power line telephone; b) configuring the power line switch to comprise at least one power interface and one telephone interface, the power line adapter to comprise at least one power interface and one telephone interface, and the power line telephone to comprise at least one power interface; c) forwarding a call from an external telephone of the power line network to a called internal telephone according to a preset protocol by the server as the external telephone dials the internal telephone, to establish a traffic link and connection therebetween, and releasing the traffic link as the communication is terminated; and d) searching for address information of a called telephone according to a preset protocol by the server as the internal telephone of the power line network dials the external telephone thereof, forwarding the call to the called external telephone by the telephone interface of the server if the address information is an external number of the power line network, so as to establish a traffic link and communication; directly making a call to establish communication if the address information is an internal number of the power line network, releasing the traffic link as the communication is terminated.
[0018] In certain classes of this embodiment, step b) further comprises configuring the power line switch to comprise at least one wide area network (WAN) interface, and the power line adapter and the power line telephone to comprise at least one local area network (LAN) interface.
[0019] In certain classes of this embodiment, step b) further comprises configuring the power line switch to comprise at least one LAN interface, the power line adapter to comprise at least one LAN interface, and the power line telephone to comprise at least one LAN interface.
[0020] In certain classes of this embodiment, step b) further includes configuring the WAN interface of the power line switch as a RJ45 interface or an optical fiber interface, for connecting to the Internet.
[0021] In certain classes of this embodiment, step b) further includes configuring the LAN interface of the power line switch as the RJ45 interface or the optical fiber interface, for connecting to the Internet.
[0022] In certain classes of this embodiment, step b) further includes configuring the telephone interface of the power line switch as an E1 interface, a T1 interface, a RJ11 interface or the optical fiber interface.
[0023] In certain classes of this embodiment, step b) further includes configuring the LAN interface of the power line adapter as the RJ45 interface or a USB interface.
[0024] In certain classes of this embodiment, step b) further includes configuring the LAN interface of the power line telephone as the RJ45 interface or the USB interface.
[0025] In certain classes of this embodiment, step c) includes forwarding a call from an external telephone of the power line network to a called internal telephone thereof according to a preset protocol by the server via the LAN interface as the external telephone dials the internal telephone, to establish a traffic link and communication therebetween.
[0026] In certain classes of this embodiment, step d) includes transmitting a called number via keypads of the client as the internal telephone of the power line network dials the external telephone thereof, so as to comply with a specification of a public telephone network.
[0027] In certain classes of this embodiment, step d) further includes forwarding the called number to the called external telephone of the power line network according to a preset protocol by the server via the WAN interface, to establish the traffic link and the connection.
[0028] The power-line-network-based user telephone communication system of the invention provides the following general advantages: (1) it is possible to utilize an existent power line network to provide and implement a user telephone communication system to facilitate user telephone communication, so as to decrease expense of establishing and maintaining end user lines, and of laying out and maintaining user lines in a user telephone switching system; and (2) communication quality of the user telephone communication system of the invention may compete with the present telephone communication system, and complies with a specification of a public telephone network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The invention is described hereinafter with reference to accompanying drawings, in which:
[0030] FIG. 1 illustrates a user telephone communication system in accordance with one embodiment of the invention;
[0031] FIG. 2 illustrates an external interface of a power line switch system in accordance with one embodiment of the invention;
[0032] FIG. 3 illustrates an external interface of a power line adapter system in accordance with one embodiment of the invention;
[0033] FIG. 4 illustrates an external interface of a power line telephone system in accordance with one embodiment of the invention;
[0034] FIG. 5 illustrates steps of an implementation method in accordance with one embodiment of the invention; and
[0035] FIG. 6 is a schematic diagram of a PSTN interface as shown in FIGS. 2 and 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0036] As shown in FIG. 1 , a power line switch 12 , functioning as a server, is connected to a power line network 20 ; also, a power line telephone 14 and a power line adapter 18 , functioning as clients, are connected to the power line network 20 . An Ethernet interface on the power line adapter 18 is connected to a computer 16 . Generally, there are multiple clients.
[0037] At least one telephone interface 22 and one power interface are connected to an external public telephone network and a power line network 20 , respectively, and are configured on the power line switch 12 . At least one Ethernet interface 24 connected to the Internet may also be configured thereon. At least one power interface and one telephone interface are configured on the power line adapter 18 ; the power interface is connected to the power line network 20 , and the telephone interface is connected to the power line telephone 14 . At least one Ethernet interface may also be configured on the power line adapter 18 , for connecting to network equipments. At least one power interface is configured on the power line telephone 14 for connecting to the power line network 20 . Moreover, an Ethernet interface may also be configured thereon for connecting to network equipments.
[0038] In this embodiment, the telephone interface 22 on the power line switch 12 may be configured as an E1 interface complying with an European rate specification, a T1 interface, a RJ11 interface, an optical fiber interface complying with US and Japanese rate specifications, or any other appropriate interfaces. The Ethernet interface 24 of the power line switch 12 includes a WAN interface and a LAN interface, and may be configured as a crystal head RJ45 interface, a fiber distributed data interface (FDDI), or any other appropriate interfaces.
[0039] In this embodiment, the telephone interface on the power line adapter 18 is configured as a RJ11 interface. The Ethernet interface on the power line adapter 18 employs the LAN interface, and is configured as the crystal head RJ45 interface or a universal serial bus (USB) interface.
[0040] In this embodiment, the Ethernet interface on the power line telephone 14 employs the LAN interface, and is configured as the crystal head RJ45 interface or the USB interface.
[0041] As shown in FIGS. 2, 3 and 4 , interfaces of the power line switch 12 , the power line adapter 18 and the power line telephone 14 of the invention are illustrated.
[0042] As shown in FIG. 5 , the implementation process begins with step s 10 , where a server and a plurality of clients are configured on a power line network. Preferably, the server is configured as a power line switch, and the clients are configured as a power line adapter and a power line telephone. Both the server and the clients are connected on the power line network, and interoperate with each other via power lines.
[0043] The process then proceeds to step s 12 , where at least one telephone interface and one power interface respectively connected to an external public telephone network and a power line network are configured on the power line switch and at least one Ethernet interface connected to the Internet is also configured thereon. At least one power interface and one telephone interface are configured on the power line adapter for respectively connecting to the power line network and the power line telephone. At least one Ethernet interface is also configured thereon for connecting to network equipments. At least one power interface is configured on the power line telephone for connecting to the power line network, an Ethernet interface is also in certain implementations configured thereon for connecting to the network equipments.
[0044] In this embodiment, the telephone interface 22 on the power line switch 12 is configured as an E1 interface complying with European rate specification, a T1 interface, a RJ11 interface and an optical fiber interface complying with US and Japanese rate specifications, or any other appropriate interfaces. The Ethernet interface of the power line switch includes a WAN interface and a LAN interface, and is configured as a crystal head RJ45 interface, a fiber distributed data interface (FDDI), or any other appropriate interfaces.
[0045] In this embodiment, the telephone interface on the power line adapter 18 is configured as a RJ11 interface. The Ethernet interface on the power line adapter 18 employs the LAN interface, and is in certain implementations configured as the crystal head RJ45 interface or a universal serial bus (USB) interface.
[0046] In this embodiment, the Ethernet interface on the power line telephone 14 employs the LAN interface, and is in certain implementations configured as the crystal head RJ45 interface or the USB interface.
[0047] The process then proceeds to step s 14 , where an internal telephone dials an external telephone of the power line network. The process then proceeds to step s 16 , where the server searches for address information of the called telephone according a preset protocol. If the called telephone is an external public telephone, the process proceeds to step s 18 , where the call is forwarded to the called external telephone via the telephone interface of the server to establish communication. If the called telephone is an external network telephone, the process proceeds to step s 20 , where the call is forwarded to the called external network telephone via the Ethernet interface to establish a traffic link, and finally, communication. If the called telephone is an internal telephone, the process proceeds to step s 22 , where a direct call is made to establish communication.
[0048] Step s 14 is in certain implementations synchronous with step s 24 , where the external telephone dials the internal telephone, followed by step s 26 and s 28 , where the external public telephone and the external network telephone dial respectively. However, it is required that the server forwards the calls to the called internal telephone according to the preset protocol, to establish a traffic link and communication therebetween.
[0049] Each of the steps s 18 , s 20 , s 22 , s 26 and s 28 is followed by step s 30 , where the communication is terminated, and the traffic link is released and unoccupied.
[0050] In step s 14 , as the internal telephone dials the external network telephone of the power line network, the called number is firstly transmitted via keypads of the clients, so as to comply with the specification of a public telephone network.
[0051] Source code for implementing steps s 20 , s 22 , s 24 , s 28 and s 30 are illustrated below:
switch (sip_state) { case SIP_STATE_IDLE: if ( !strncmp(uip_appdata,“INVITE”,6) ) { pTemp = t_strstr(uip_appdata, “from:”); // get sender's user name pTemp = t_strstr(pTemp, “sip:”) + 4; t_memccpy(remoteUsername, pTemp, ‘@’, USERNAME_LENGTH); pTemp = t_strstr(uip_appdata, “call-id:”) + 9; // get CALL-ID t_memccpy(callID, pTemp, ‘\r’, CALLID_LENGTH); getCseq( ); // get cseq getTag(1); // get sender's tag getVia( ); // get sender's Contact Url getRTPAddressPort( ); // get sender's RTP address and port send180( ); // send 180 and start ringing sip_state = SIP_STATE_RING; } else if ( !strncmp(uip_appdata,“BYE”,3) ) { getVia( ); send200(1); } else if ( !strncmp(uip_appdata, “SIP/2.0 487”, 11) ) { sendAck( ); processed = 1; } else if (!strncmp(uip_appdata, “SIP/2.0 486”, 11)) { sendAck( ); processed = 1; } break; case SIP_STATE_RINGING: if ( !strncmp(uip_appdata, “SIP/2.0 200”, 11) ) { getTag(0); // get sender's tag getContact( ); // get sender's Contact Url getRTPAddressPort( ); // get sender's RTP address and port getRoute( ); // get router info. sendAck( ); // send ACK, and start talking sip_state = SIP_STATE_ESTABLISHED; Disp_LCD(3, &sip_state, 1); G723_Work_Start( ); } else if (!strncmp(uip_appdata, “SIP/2.0 486”, 11)) { sendAck( ); sip_state = SIP_STATE_IDLE; processed = 1; } break; case SIP_STATE_RING: if ( !strncmp(uip_appdata,“CANCEL”,6) ) { // cancel call pTemp = t_strstr(uip_appdata, “cseq:”) + 6; t_memccpy(cseqNumberCancel, pTemp, ‘ ’, CSEQ_LENGTH); send200(2); sip_state = SIP_STATE_CANCELED; } else if ( !strncmp(uip_appdata,“INVITE”,6) ) { // re-send 180 send180( ); } break; case SIP_STATE_OK: if ( !strncmp(uip_appdata,“ACK”,3) ) { // start talking Disp_LCD(3, &sip_state, 1); sip_state = SIP_STATE_ESTABLISHED; G723_Work_Start( ); } else if ( !strncmp(uip_appdata,“INVITE”,6) ) { // re-send 200 send200(0); } break; case SIP_STATE_ESTABLISHED: if ( !strncmp(uip_appdata,“BYE”,3) ) { // get BYE request getVia( ); send200(1); sip_state = SIP_STATE_IDLE; Disp_LCD(3, &sip_state, 1); G723_Work_Stop( ); } else if ( !strncmp(uip_appdata, “SIP/2.0 200”, 11) ) { sendAck( ); } break; .................. case SIP_STATE_CANCEL: if ( !strncmp(uip_appdata, “SIP/2.0 487”, 11) ) { sendAck( ); sip_state = SIP_STATE_IDLE; processed = 1; } break; case SIP_STATE_CANCELED: if ( !strncmp(uip_appdata,“CANCEL”,6) ) { send200(2); } break; case SIP_STATE_TERMINATING: if ( !strncmp(uip_appdata,“ACK”,3) ) { sip_state = SIP_STATE_IDLE; } else if ( !strncmp(uip_appdata,“CANCEL”,6) ) { send200(2); sip_state = SIP_STATE_CANCELED; } break; case SIP_STATE_BUSY: if ( !strncmp(uip_appdata,“ACK”,3) ) { sip_state = SIP_STATE_IDLE; } break; default: break; }
[0052] In FIG. 6 shown is a schematic diagram of a PSTN interface illustrated in FIGS. 2 and 3 .
[0053] 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, and 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.
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Disclosed herein is a network-based voice over power lines (VoPL) telephone communication system, comprising a power line network, multiple clients and a server. The clients are respectively connected to the power line network for providing access for a user telephone and/or for providing a user operation interface. The server comprises at least one power interface and one telephone interface connected to the power line network, and to the clients via the power line network, for handling calls and transfer from the clients. The clients comprise power line adapters and/or power line telephones, the power line adapter comprises at least one power interface and one telephone interface for inputting numbers and/or information via keypads to make a call, and the power line telephone comprises at least one power interface for inputting numbers and/or information via keypads to make a call. An implementation method for a network-based voice over power lines (VoPL) telephone communication system is also disclosed herein.
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FIELD OF THE INVENTION
The present invention relates in general to implantable cardiac stimulation devices, including bradycardia and anti-tachycardia stimulation devices, defibrillators, cardioverters and combinations thereof that are capable of measuring physiological data and parametric data pertaining to implantable medical devices. More particularly, this invention relates to a system and method for automating detection of atrial capture and determination of an atrial pacing threshold in an implantable cardiac stimulation device.
BACKGROUND OF THE INVENTION
Implantable cardiac stimulation devices (such as pacemakers, defibrillators, and cardioverters) are designed to monitor and stimulate the heart of a patient that suffers from a cardiac arrhythmia. Using leads connected to a patient's heart, these devices typically stimulate the cardiac muscles by delivering electrical pulses in response to detected cardiac events which are indicative of a cardiac arrhythmia. Properly administered therapeutic electrical pulses often successfully reestablish or maintain the heart's regular rhythm.
Implantable cardiac stimulating devices can treat a wide range of cardiac arrhythmias by using a series of adjustable parameters to alter the energy, the shape, the location, and the frequency of the therapeutic pulses. The adjustable parameters are usually defined in a computer program stored in a memory of the implantable device. The program (which is responsible for the operation of the implantable device) can be defined or altered telemetrically by a medical practitioner using an external implantable device programmer.
Modern implantable devices have a great number of adjustable parameters that must be tailored to a particular patient's therapeutic needs. One adjustable parameter of particular importance in stimulation devices is the stimulus energy (i.e., the pulse amplitude and pulse width) which can be programmed to new values in response to changes in capture threshold. “Capture” is defined as a cardiac depolarization and contraction of the heart in response to a stimulation pulse. When a stimulation pulse stimulates either a patient's atrium or ventricle during an appropriate portion of a cardiac cycle, it is desirable to have the heart properly respond to the stimulus provided. Every patient has a “capture threshold” which is generally defined as the minimum amount of stimulation energy necessary to effect capture. Capture should be achieved at the lowest possible energy setting yet provide enough of a safety margin so that should a patient's threshold increase, the output of an implantable stimulation device (i.e. the pacing stimulus energy) will still be sufficient to maintain capture. Dual chamber stimulation devices may have different atrial and ventricular pacing stimulus energies that correspond to different atrial and ventricular capture thresholds, respectively.
The earliest stimulation devices had a predetermined and unchangeable pacing stimulus energy, which proved to be problematic because the capture threshold is not a static value. The capture threshold also may be affected by a variety of physiological and other factors. For example, certain cardiac medications may temporarily raise or lower the threshold from its normal value. In another example, fibrous tissue that forms around stimulation device lead tips within several months after implantation may cause an increase in the capture threshold. To avoid loss of capture, the earliest stimulation devices were preset to deliver pacing pulses at the maximum energy available. As a result some patients experienced discomfort because of the high level of stimulation. Furthermore, such stimulation pulses consumed extra battery resources, thus shortening the useful life of a stimulation device.
When programmable stimulation devices were developed, the pacing stimulus energy was implemented as an adjustable parameter that could be set or changed by a medical practitioner. Typically, such adjustments were effected by the medical practitioner using an external programmer capable of communication with an implanted stimulation device via telemetry or via a magnet applied to a patient's chest. The particular setting for the stimulation device's pacing threshold was usually derived from the results of extensive physiological tests performed by the medical practitioner to determine the patient's capture threshold, from the patient's medical history, and from a listing of the patient's medications. This improvement in adjustable pacing stimulus energy permitted programming to lower values that tended to conserve battery energy and extend the useful service life of the stimulation device.
Also, patients who experienced discomfort due to excessively high stimulus energy pulses could have the stimulus energy safely decreased thus, lessening the incidence of surgical revision of the pacing system. While the adjustable pacing stimulus energy feature proved to be superior to the previously known static stimulus energy, some significant problems remained unsolved. In particular, when a patient's capture threshold changed, the patient was forced to visit the medical practitioner to adjust the pacing stimulus energy accordingly.
To address this pressing problem, manufacturers have developed advanced stimulation devices that are capable of determining a patient's capture threshold and automatically adjusting the stimulation pulses to a level just above that which is needed to maintain capture. This approach, referred to herein as “autocapture”, improves the patient's comfort, reduces the necessity of unscheduled visits to the medical practitioner, and greatly increases the stimulation device's battery life by conserving the energy used for stimulation pulses.
A common technique used to determine whether capture has been effectuated is to monitor the patient's cardiac activity and to search for presence of an “evoked response” following a stimulation pulse. The evoked response is an electrical event that is the response of the heart to the application of a stimulation pulse thereto. The patient's heart activity is typically monitored by the stimulation device by keeping track of the stimulation pulses delivered to the heart and by examining, through the leads connected to the heart, electrical signals that are manifest concurrent with depolarization or contraction of muscle tissue(myocardial tissue) of the heart. The contraction of atrial muscle tissue is evidenced by the generation of a P-wave, while the contraction of ventricular muscle tissue is evidenced by the generation of an R-wave (sometimes referred to as the “QRS” complex when viewed on an ECG strip).
When capture occurs, the evoked response is an intracardiac P-wave or R-wave that indicates contraction of the respective cardiac tissue in response to the applied stimulation pulse. For example, using such an evoked response technique, if a stimulation pulse is applied to the atrium (hereinafter referred to as an “A-pulse”), any response sensed by atrial sensing circuits of the stimulation device immediately following application of the A-pulse is presumed to be an evoked response that evidences capture of the atria.
However, it is for several reasons very difficult to detect a true atrial evoked response. First, a high energy A-pulse may obscure the evoked response signal, making it difficult to detect and identify. Second, the signal sensed by the atrial sensing circuitry immediately following the application of an A-pulse may be not an evoked response, but noise—either electrical noise caused, for example, by electromagnetic interference, or myocardial noise caused by random myocardial or other muscle contraction.
Another signal that interferes with the detection of an evoked response, and potentially the most difficult for which to compensate because it is usually present in varying degrees, is lead polarization. A lead/tissue interface is that point where an electrode of the lead contacts the cardiac tissue. Lead polarization is commonly caused by electrochemical reactions that occur at the lead/tissue interface due to application of an electrical stimulation pulse, such as the A-pulse, across the interface. Unfortunately, because the atrial evoked response is sensed through the same lead electrode through which the A-pulse is delivered, the resulting polarization signal formed at the electrode can corrupt the evoked response sensed by the atrial sensing circuits. Furthermore, the lead polarization signal is not easily characterized; it is a complex function of the lead materials, lead geometry, tissue impedance, stimulation energy, and other variables, many of which are continually changing over time.
In each case, the result may be a false positive detection of an atrial evoked response. Such an error leads to a false atrial capture indication, which in turn leads to missed heartbeats—a highly undesirable and potentially a life-threatening situation. Another problem results from a failure by the stimulation device to detect an atrial evoked response that has actually occurred. In this case, a loss of atrial capture is indicated when atrial capture is in fact present—also an undesirable situation that will cause the stimulation device to unnecessarily invoke the atrial pacing threshold determination function and result in higher than necessary stimulus energy values.
Because of the problems previously stated regarding the test for atrial capture verification and automatic threshold tests, currently available stimulation devices do not have this capability. As a result, many medical practitioners manually conduct atrial capture verification tests during periodic follow up examinations. These periodic follow-up examinations are performed by the medical practitioner after initial implantation and configuration of the stimulation device to determine whether the therapy delivered by the device is having the desired effect and to verify the proper operation. Capture verification and pacing threshold assessment is typically performed by the medical practitioner using an external programmer for controlling the stimulation device functions in conjunction with a surface electrocardiogram (ECG) device.
However, this common capture verification and pacing threshold assessment procedure is a time consuming and complex task requiring significant attention and effort on the part of the medical practitioner. The medical practitioner must spend a significant amount of time placing and subsequent removal of ECG electrodes, and configuring the ECG system for the patient's individual characteristics. The practitioner must also manually examine the ECG readout and analyze the cardiac waveform to determine whether capture is present both during initial capture verification and during the pacing threshold determination tests.
It would thus be desirable to provide a system and method for enabling the stimulation device to automatically perform atrial capture verification and atrial pacing threshold determination without a medical practitioner's involvement. It would also be desirable to enable the stimulation device to perform the atrial capture verification and atrial pacing threshold determination without requiring dedicated circuitry and/or special sensors. It would further be desirable to maintain a record of atrial pacing threshold determination in the stimulation device so that a medical practitioner can verify the proper operation of the stimulation device by examining the record.
SUMMARY OF THE INVENTION
The disadvantages and limitations discussed above are overcome by the present invention. In accordance with the invention, a system and method are provided for automating (1) verification of proper atrial capture affected by atrial pacing pulses generated by a patient's implantable cardiac stimulation device, and (2) dynamic adjustment of the device's atrial pacing stimulus energy if and as necessary. The system and method of the present invention do not require use of special dedicated circuitry or special sensors to implement the automated procedures. All of the aforesaid advantages and features are achieved without incurring any substantial relative disadvantage.
The present invention is directed towards the pacing pulse generating portion of an implantable cardiac stimulation device (i.e., a bradycardia pacemaker or the pacing portion of a combination ICD/pacemaker device).
A preferred embodiment of the stimulation device includes a control system for controlling the operation thereof, a set of leads for receiving atrial and ventricular signals and for delivering atrial and ventricular stimulation pulses, a set of sense amplifiers for sensing and amplifying the atrial and ventricular signals, and pulse generators for generating the atrial and ventricular stimulation pulses. In addition, the stimulation device includes memory for storing operational parameters for the control system, and for storing data acquired by the control system for later retrieval by the medical practitioner using an external programmer. The stimulation device also includes a telemetry circuit for communicating with an external programmer.
Preferably, the stimulation device of the present invention is a dual chamber rate-responsive device with atrial tracking modes (such as, DDD and DDD(R)) capable of switching modes to at least a non-tracking mode (such as, DDI and DDI(R)). Accordingly, an activity sensor is also included for sensing when the patient is at, or near, rest.
In a preferred embodiment, the control system periodically performs an atrial capture verification test and an atrial pacing capture threshold assessment test. The frequency with which these tests are to be performed is preferably a programmable parameter set by the medical practitioner using an external programmer when the patient is examined during an office visit or remotely via a telecommunication link. The appropriate testing frequency parameter will vary from patient to patient and depend on a number of physiologic and other factors. For example, if a patient is on a cardiac medication regimen, the patient's atrial capture threshold may fluctuate thus requiring relatively frequent testing and adjustment of the atrial pacing threshold.
In order for the capture verification and threshold assessment tests to work properly, the patient preferably should be at, or near, rest such that a stable atrial rhythm can be monitored by the stimulation device. Thus, prior to initiating atrial capture verification, the control system detects whether the patient is at, or near, rest using the patient activity sensor. If the patient is not at or near rest, the control system waits for a predetermined period of time before attempting to initiate the test again.
When the control system finally determines that the patient is at or near rest, the atrial capture verification test is initiated by first assessing the intrinsic atrial rate or P—P interval. The intrinsic atrial rate must be greater than the base rate such that the intrinsic, or native, P-waves are detectable. When the stimulation device is pacing, the Base Rate must be temporarily programmed to a lower value to allow the intrinsic atrial rate to emerge from the pacing rate. The reprogramming of the Base Rate may be performed in decrements of 5 to 10 ppm until a minimum lower rate, not less than 30 ppm is obtained. The temporary lower rate can be limited by the medical practitioner through the use of the programmer. If the rate of 30 ppm (or the minimum prescribed lower Base Rate of the stimulation device) is reached without the emergence of an intrinsic rhythm, the capture assessment test is automatically terminated.
With the emergence of an intrinsic atrial rate, greater than the Base Rate, the mode of operation is changed from the atrial tracking modes (such as, DDD and DDD(R)) to a non-tracking mode (such as, DDI and DDI(R)). This temporary mode change is necessary to avoid occurrence of a Pacemaker Mediated Tachycardia (PMT) during the testing process. A PMT is a type of arrhythmia that sometimes occurs in VDD or DDD type stimulation devices, in which sensing of retrograde P-waves occurs in the atrium and triggers the ventricle. Retrograde conduction occurs in response to ventricular pacing, causing atrial contraction (i.e. a P-wave). Sensing of this P-wave causes the ventricle to again be stimulated, completing an “endless” loop and thus subjecting the patient to PMT. Switching of the stimulation device into DDI mode eliminates the triggered response in the ventricle, thus preventing the occurrence of PMT.
After the mode switch, the control system monitors and measures the patient's average P-wave interval over a short period of time, and then defines an expected P-wave “window” of predetermined duration in which P-waves are expected to occur. The control system next generates an A-pulse at a predetermined prematurity time interval prior to the next expected P-wave window and thereafter monitors the expected P-wave window to determine whether a P-wave occurs within the window. The lack of a P-wave within that window indicates that an evoked P-wave occurred as a response to the A-pulse immediately following the A-pulse (i.e., outside the expected intrinsic P-wave window). Thus, if a P-wave is not detected during the window, atrial capture is present. If atrial capture is thus verified, the control system switches the stimulation device back to original atrial tracking mode (i.e., DDD or DDD(R)) and ends the atrial capture verification test.
The presence of a P-wave within the window, on the other hand, indicates that there was no P-wave immediately following the A-pulse and thus no atrial capture. In this case, the control system needs to perform the atrial pacing threshold assessment test to set a new atrial pacing threshold to re-establish atrial capture.
The control system sets atrial stimulation (i.e. the A-pulse) level below the previous atrial pacing level (or at a level that is expected to be below the patient's capture threshold), generates the A-pulse and monitors the window for a P-wave. If a P-wave is again detected within the window, then the control system increments the A-pulse level and then generates the A-pulse at the higher level while monitoring the window. This process continues until a P-wave is no longer present during the window interval.
The control system continues to monitor the window for a predetermined number of pacing cycles to ensure that no P-waves occur within the window, and then records the atrial pacing stimulus energy at the current A-pulse output level as the threshold value and, optionally, adds an additional safety margin to the A-pulse threshold value. The control system records the atrial pacing threshold, the atrial stimulation levels, and other test-related data in the memory, and then switches the stimulation device back to original atrial tracking mode before ending the test.
The incremental atrial pacing threshold test of the present invention significantly differs from previously known approaches because atrial stimulus output is initially set lower than the current threshold and progressively increased until capture occurs, while previously known approaches set initial atrial output at a high level and then decrement until capture is lost. The progressive output increase approach is advantageous over prior approaches because less electrical energy is consumed during the testing process and, moreover, because the window observed by the control system is not “swamped” by high output level pulses.
In an alternate embodiment, the method of incrementally increasing the A-pulse level can also be used in an atrial capture system that employs an “evoked response” detection window following a stimulus, wherein only a paced, or evoked, P-wave in the detection window indicates capture, as is well known in the art.
Optionally, if the patient suffers from sinus bradycardia that is accompanied by retrograde conduction, the expected P-wave window is set to at least a predetermined portion of the cardiac cycle, and the control system then searches for retrograde P-waves within the window. Similarly, presence of retrograde P-waves within the window indicates loss of capture, while lack of retrograde P-waves confirms capture. If necessary, the atrial pacing threshold is assessed and set in the same manner as previously described.
The system and method of the present invention thus automatically verify atrial capture and, when necessary, automatically determine a proper atrial pacing threshold of the patient, without requiring dedicated or special circuitry and/or sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further features, advantages and benefits of the invention will become apparent in the following description taken in conjunction with the following drawings. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory but are not intended to be restrictive of the invention. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate one of the embodiments of the invention and, together with the description, serve to explain the principles of the invention in general terms. Like numerals refer to like parts throughout the disclosure.
FIG. 1 is a block diagram of a dual chamber stimulation device in accordance with the principles of the present invention; and
FIGS. 2-4 are a logic flow diagram representing an automatic atrial capture verification and atrial pacing threshold determination control program executed by the control system of the stimulation device of FIG. 1, in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The system and method of the present invention utilize a stimulation device's normal sensing, pulse generating and control circuitry to perform an automatic atrial capture verification and, when necessary, an atrial pacing threshold determination test.
A stimulation device 10 in accordance with the invention is shown in FIG. 1 . The stimulation device 10 is coupled to a heart 24 by way of leads 32 and 34 , the lead 32 having an electrode 18 which is in contact with one of the atria of the heart 24 , and the lead 34 having an electrode 20 which is in contact with one of the ventricles. The lead 32 carries stimulating pulses to the electrode 18 from an atrial pulse generator 16 , while the lead 34 carries stimulating pulses to the electrode 20 from a ventricular pulse generator 22 . In addition, electrical signals from the atria are carried from the electrode 18 , through the lead 32 to the input terminal of an atrial sense amplifier 26 . Electrical signals from the ventricles are carried from the electrode 20 , through the lead 34 to the input terminal of a ventricular sense amplifier 28 .
Controlling the dual chamber stimulation device 10 is a control system 30 . The control system 30 is preferably a microprocessor-based system such as that disclosed in commonly assigned U.S. Pat. No. 4,940,052 of Mann, which is incorporated herein by reference in its entirety. The control system 30 may also be a state logic-based system such as that disclosed in commonly assigned U.S. Pat. No. 4,944,298 of Sholder, which is incorporated herein by reference in its entirety. The control system 30 also includes a real-time clock (not shown) for providing timing functionality for monitoring cardiac events and for timing the application of therapeutic pulses by the pulse generators 16 and 24 .
The stimulation device 10 also includes a memory 14 which is coupled to the control system 30 . The memory 14 allows certain control parameters used by the control system 30 in controlling the operation of the stimulation device 10 to be programmably stored and modified, as required, in order to customize the operation of the stimulation device 10 to suit the needs of a particular patient. In particular, the pacing stimulus energy parameters for the pacing pulses are stored in the memory 14 . In addition, data sensed during the operation of the stimulation device 10 , as for example during atrial capture verification and atrial pacing threshold assessment tests, may be stored in the memory 14 for later retrieval and analysis by a medical practitioner using an external programmer.
The control system 30 receives the output signals from the atrial amplifier 26 . Similarly, the control system 30 also receives the output signals from the ventricular amplifier 28 . These various output signals are generated each time that an atrial event (e.g., a P-wave) or a ventricular event (e.g., an R-wave) is sensed within the heart 24 .
The control system 30 also generates an atrial trigger signal which is sent to the atrial pulse generator 16 , and a ventricular trigger signal which is sent to the ventricular pulse generator 22 . These trigger signals are generated each time that a stimulation pulse is scheduled to be generated by one of the pulse generators 16 or 22 . The atrial stimulation pulse is referred to simply as the “A-pulse,” and the ventricular stimulation pulse is referred to as the “V-pulse.” The characteristics of these stimulation pulses are determined by the pacing stimulus energy settings that are stored in the memory 14 .
During the time that either an A-pulse or a V-pulse is being delivered to the heart 24 , the corresponding atrial sense amplifier 26 or the ventricular amplifier 28 is typically disabled by way of a blanking signal presented to the appropriate amplifier 26 or 28 from the control system 30 . This blanking action prevents the amplifiers 26 and 28 from becoming saturated with the relatively large stimulation pulses that are present at their input terminals during pacing pulse delivery. It also prevents residual electrical signals (known as “after-potentials” or polarization) present at the electrode tissue interface from being interpreted as atrial or ventricular events. During the atrial capture verification and atrial pacing threshold assessment tests of the invention, the atrial sense amplifier 26 is preferably enabled so that P-waves may be detected during all portions of the pacing cycle.
The stimulation device 10 also includes an activity sensor 36 connected to the control system 30 for determining whether the patient is at or near rest. The activity sensor 36 is typically used in rate-responsive stimulation devices to alter the pacing rate to match the patient's physical activity. The control system 30 will only initiate the tests when it determines that the patient is at or near rest.
A telemetry circuit 12 is further included in the stimulation device 10 connected to the control system 30 . The telemetry circuit 12 may be selectively coupled to an external programmer 100 by means of an appropriate communication link 112 , such as an electromagnetic telemetry link or a remote communication link such as a pair of modems interconnected via a telecommunications link and equipped with telemetry capabilities.
The operation of the stimulation device 10 is generally controlled by a control program stored in the memory 14 and executed by the control system 30 . This control program typically consists of multiple integrated program modules, with each module bearing responsibility for controlling one or more functions of the stimulation device 10 . For example, one program module may control the delivery of stimulating pulses to the heart 24 , while another may control the verification of atrial capture and atrial pacing threshold determination. In effect, each program module is a control program dedicated to a specific function or set of functions of the stimulation device 10 . The control program module dedicated to controlling the atrial capture verification and atrial pacing threshold determination tests is described below in connection with FIG. 2 .
FIGS. 2-4 are a flow diagram representing the control program for assessing atrial capture and performing an atrial capture threshold assessment test.
In a preferred embodiment of the invention, the control system 30 periodically invokes the control program to perform the atrial capture verification test and the atrial pacing threshold assessment tests. The frequency with which these tests are to be performed is preferably a programmable parameter set by using the external programmer 100 . Alternatively the programmer may be used to initiate a test sequence when the patient is examined during an office visit or remotely via the communication link 112 . The appropriate testing frequency parameter will vary from patient to patient and depend on a number of physiologic and other factors. For example, if a patient is on a cardiac medication regimen, the patient's atrial capture threshold may fluctuate, thus requiring relatively frequent threshold testing and adjustment of the atrial pacing stimulus energy.
There are three different patient conditions during which the capture verification test and the atrial pacing threshold assessment tests may be performed. Most commonly each patient will exhibit one or two of the conditions and rarely only all three conditions. The three conditions usually do not exist simultaneous but, may be present in combination at various times in the same patient. The conditions may dependent upon the patient's daily level of activity, drug regime and time of day. Additionally, the condition may change within each patient as a function of the progression of the disease process expressed as the indications for having a stimulation device implanted and the associated symptoms.
The three patient conditions may be described as (a) an intrinsic atrial rhythm with a rate greater than the programmed Base Rate, (b) an intrinsic atrial rhythm that is over shadowed by pacing at a rate greater than the intrinsic atrial rate, and (c) a paced atrial rhythm where the intrinsic rate is very slow (i.e., in some patients with a very slow intrinsic rhythm, the patient may be symptomatic when paced in a DDD mode at the low atrial rate due to insufficient cardiac output resulting in low peripheral perfusion). Accordingly, each condition will be described separately below.
INTRINSIC ATRIAL RATE>THE PROGRAMMED BASE RATE
As shown in FIGS. 2-3, and with reference to FIG. 1, when the test sequence is initiated (at step 200 ) and the patient's condition is one where the intrinsic atrial rate is greater than the programmed Base Rate, the control system 30 first determines whether the patient is at, or near, rest (at step 202 ). Being at rest, provides the best opportunity for detecting when the atrial rhythm and rate are stable. During step 202 , the sensor 36 provides comparative information to the control system 30 to detect the rest state. If the patient is not at, or near, rest, the initiation of the test sequence is delayed by an amount of time (at step 204 ) and then the test for the patient to be at, or near rest, is reassessed.
Once rest is detected (at step 202 ), the mode is temporarily changed from an atrial tracking mode (i.e., DDD) to a non-atrial tracking mode (i.e., DDI) (at step 206 ). This mode change prevents the stimulation device from tracking a retrograde P-wave, thus preventing a Pacemaker Mediated Tachycardia (PMT).
The control system 30 next tests for the presence of an intrinsic atrial rate (at step 208 ) and measures the average P—P interval (at step 210 ) over sufficient period of time to verify that the patient's atrial rhythm is stable. A stable atrial rhythm and rate will consistently produce P-waves in a defined detection window as determined in step 212 . The detection window frequency and duration is calculated by the control system 30 and is dependent upon the measured P-P interval.
The capture verification assessment test proceeds with an A-pulse generated (at step 214 ) at a predetermined “prematurity” interval, i.e., the generated premature A-pulse will be delivered within a cardiac cycle prior to the occurrence of the P-wave detection window and after the previous detected paced or sensed ventricular beat. The amplitude of the A-pulse is typically predetermined (i.e., programmable or set by the manufacturer). The control system 30 will monitor for P-waves (at step 216 ) within the predetermined detection window found (at step 212 ).
Capture by the premature A-pulse is initially detected by the absence of a P-wave in the detection window as determined (at step 218 ). If capture is detected (that is, no P-waves are occurring in the detection window, (at step 218 ), then the control system 30 will continue to monitor the absence of P-waves in the detection window for, a predetermined number, “N”, of cycles and further may apply additional criteria (e.g., “F” out of “N” cycles) (at step 222 ).
If either a P-wave is found in the detection window (yes in step 218 ) or there has not been a predetermined number of cycles without P-waves (no in step 222 ), then capture is not confirmed and the A-pulse will be incremented in step 220 .
Once the capture has been found (at step 222 ), the control system 30 will check to see if it is time to perform a capture threshold test, (at step 224 ), to re-establish the lowest threshold.
If it is time for such a test, the A-pulse stimulus amplitude is temporarily decreased to a value expected to be below threshold (at step 226 ) (e.g., a minimum predetermined value or a value less than the previously recorded threshold value). At this point the loop sequence repeats itself: a premature A-pulse is generated (step 214 ); the control system 30 monitors for a P-wave within the P-wave detection window (step 216 ); if a P-wave is detected (step 218 ), then the A-pulse stimulus amplitude is incremented (step 220 ); and this loop is repeated until the absence of a P-wave is detected (e.g., in “F” out of “N” P-waves) (step 222 ).
If it is not time for a threshold test (no, at step 224 ), the control system 30 continues to “C” in FIG. 3 . At step 228 , the control system 30 determines whether a capture assessment test was performed, or simply a capture recovery for a single loss of capture. If a capture assessment test was performed, then the A-pulse stimulus amplitude is recorded as the stimulus threshold value (step 232 ). If it was a capture recovery, then the new value of the pulse energy is recorded and used until it is time for the next capture assessment test. In either case, a safety margin is added (step 238 ) and store the new A-pulse stimulus value (including the safety margin) into memory 14 (step 240 ). Finally, the control system 30 will restore all previously programmed parameter values (excluding, of course, the A-pulse stimulus amplitude) in step 280 and end the sequence in 290 (i.e., continue with other pacing routines).
INTRINSIC ATRIAL RATE<THE BASE RATE
As shown in FIGS. 2 and 4, when the patient's condition is one where the intrinsic atrial rate is less than the programmed Base Rate, the control system 30 will determine (at step 208 , FIG. 2) that the stimulation device is pacing the atrium because the intrinsic atrial rate is less than the Base Rate of the stimulation device (no, at step 208 ).
As such, the control system 30 will proceed to step 250 (see “A” in FIG. 4 ), and determines whether one of the following modes has been pre-programmed based on prior knowledge of what the patient can best tolerate: (a) temporarily decrementing the Base Rate, or (b) perform a retrograde conduction test (at step 250 ). For the moment, the description below will describe option (a) and discuss option (b) thereafter.
Accordingly, the control system 30 proceeds to step 252 and temporarily decreases the Base Rate based on the prior knowledge that this particular patient can tolerate a temporary lower heart rate that originates from a slow atrial rate.
For the condition that the temporary Base Rate value is greater than the minimum allowable lower rate value, the control system tests for the presence of an intrinsic P-waves (at step 254 ), and preferably that the P-waves repeat with consistency (e.g., by verifying that there are at least “F” out of “N” P-waves).
When P-waves do not exist with the desired consistency (no, at step 254 ), indicating that a paced atrial rhythm is detected, the control system 30 proceeds to step 256 to determine if the new temporary Base Rate is equal to the minimum allowable value which is predetermined and stored in memory 14 . If it is not, then an additional temporary decrement of the Base Rate occurs (at step 252 ). This sequence is repeated until such time as the intrinsic atrial rhythm emerges or the minimum allowable Base rate is reached.
If, the minimum temporary Base Rate is reached (at step 256 ), and an intrinsic atrial rhythm has not emerged, as tested at step 254 , the entire test will be terminated, the original pacing mode and other parameters are restored, and the test failure may be date and time stamped and recorded (at step 274 ) and the test sequence ends (at step 290 ). The test failure information can be retrieved later via telemetry with the external programmer 100 .
When P-waves do exist with the desired consistency (yes, at step 254 ), the control system 30 proceeds to step 210 (“B” in FIGS. 2 and 4) and the method steps 210 - 290 , of establishing a detection window and for assessing whether P-waves fall within this window, then continues, as described above.
INTRINSIC ATRIAL RATE<BASE RATE WITH SYMPTOMS FROM BRADYCARDIA
As also shown in FIGS. 2 and 4, when the patient's condition is one where the intrinsic atrial rate is less than the programmed Base Rate, the control system 30 will again determine (at step 208 , FIG. 2) that the stimulation device is pacing the atrium because the intrinsic atrial rate is less than the Base Rate of the stimulation device (no, at step 208 ).
However, based on the prior knowledge that this particular patient does not tolerate a temporary lower heart rate that originates from a slow atrial rate, the control system 30 will determine that a Retrograde Conduction test is need (at step 250 ), as previously programmed into the device by the physician. The control system 30 will then proceed with a Retrograde Conduction test (at step 260 , in FIG. 4 ).
The Retrograde Conduction test is preferred when the patient might experience symptoms such as those that result from low cardiac output resulting from the low intrinsic rate and it is performed at the programmed Base Rate. The Retrograde Conduction test begins with the atrial stimulus energy temporarily set to a desired minimum output (at step 262 ). This is done to effectively simulate VVI pacing while maintaining the stimulation device in the DDI dual chamber mode previously selected (at step 206 ).
By virtue of the determination of step 208 (FIG. 2 ), the stimulation device is currently pacing at a rate greater than the patient's intrinsic rate and therefore the patient should be paced in the ventricle without a synchronizing atrial event, paced or sensed, preceding the ventricular stimulus pulse. The lack of a preceding physiologic encourages retrograde conduction of a signal from the paced or naturally depolarized ventricle to the atrium. A retrograde conducted electrical signal results in an atrial contraction, or depolarization, as evidenced by a P-wave. The presence of the P-wave establishes retrograde conduction and could only exist in response to an isolated ventricular contraction not preceded by an atrial depolarization, and a retrograde conduction pathway. An atrial stimulus of sufficient amplitude so as to cause evoke a P-wave prior to the ventricular paced event will block the retrograde conduction pathway such that a retrograde P-wave will not occur soon after the ventricular depolarization.
As shown in FIG. 4, the retrograde P-wave is detected (at step 264 ) for several (e.g., “N”) beats and preferably “F” out of “N” times to ensure consistency. If step 264 is met, the measured interval between the V-Pulse to P-wave for the retrograde conduction is determined (at step 266 ). A retrograde detection window for the expected P-wave is established based on the average of a series of measured V-Pulse to P-wave intervals (at step 268 ).
The presence of retrograde conduction is confirmed by P-waves always appearing in the retrograde detection window. Conversely, when a retrograde P-wave is not present in the retrograde detection window in response to an applied atrial stimulus, the absence indicates that the A-Pulse captured the atrium just prior the V-Pulse, thereby causing the retrograde pathway to be refractory to conduction. Thus, the value of the atrial stimulus energy when the retrograde P-wave disappears is the atrial capture threshold.
Accordingly, the atrial stimulus energy is incremented (at step 270 ) and when the presence of the retrograde P-wave is detected and, preferably, counted as “F” out of “N” cycles (at step 272 ), atrial capture is not found. The atrial stimulus energy is then incremented again (at step 270 ) and the retrograde P-wave detection and counting process continues to loop between steps 270 and 272 , until retrograde P-waves are not present (no, at step 272 ). Thus, the value of the atrial stimulus energy when the retrograde P-wave disappears is the atrial capture threshold.
Alternatively, is the Retrograde Conduction test does not satisfy the desired (e.g., “F” out of “N”) criteria in step 264 , the test is terminated (at step 274 ), the original pacing mode and other parameters are restored, and the test failure may be date and time stamped and recorded in memory 14 (at step 274 ) and the test sequence ends (at step 290 ). The test failure information can be retrieved later via telemetry with programmer 100 .
The invention is not limited by the embodiments described above, which are presented as examples only, but can be modified in various ways within the scope of protection defined by the appended patent claims.
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An implantable dual chamber stimulation device provides a novel detection scheme for automatically detecting atrial capture and performing an atrial pacing threshold assessment. The stimulation device preferably waits until the patient is at or near rest and monitors the patient's P-wave activity to determine an detection window where a next P-wave is expected to occur. The stimulation device then delivers an atrial pulse prior to the next detection window, and monitors the window to determine whether a P-wave occurs therein. If a P-wave does not occur, then atrial capture is present, while occurrence of a P-wave indicates absence of atrial capture. If atrial capture is absent, the stimulation device automatically determines an appropriate atrial pacing threshold by monitoring the detection window while adjusting the stimulation pulse energy level. Advantageously, the present invention further employs a “bottom-up” adjusting scheme which starts at a low energy level, below the expected atrial pacing threshold, and increases the energy level until atrial capture is detected, thus saving energy and further avoiding corruption by large polarization signals. The latter feature is compatible with the present detection scheme and conventional evoked response detection schemes. The new atrial pacing threshold is then set at the atrial pulse level at which atrial capture was effectuated plus a predetermined safety margin.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is cross-referenced to and claims the benefit from U.S. Provisional Patent Application 60/995,165 filed Sep. 26, 2007, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to a guardrail post connection. More particularly, the invention relates to securing a railing post to a deck base in a manner that provides both shear and tension strength to the post, while enabling easy and correct installation.
BACKGROUND
[0003] Building codes require guardrail posts to resist 200 pounds at the top of the post in all directions with a safety factor of 2.5. The typical connections used to connect guardrail posts to wood framed decks fail to meet this requirement, according to published test results for a 36-inch post length. Current codes in many states now require the post connections pass a minimum 200-pound resistance test for a 42″ post length.
[0004] One significant defect in guardrail post connectors that integrate both a rim joist and a joist to the post is the presence of an eccentric moment between the connector and the joist. A tensile load resistant component that is displaced from the connection to the joist creates an eccentric moment in the connection that limits the strength of the connection. Failure of the guardrail post and thereby guardrails have resulted in injuries and death.
[0005] Accordingly, there is a need to develop a guardrail post connection that reduces or eliminates eccentric moments between the tensile force resistant section and the coupling at the joist, and enables easy and correct assembly of deck railing posts to a deck base while supplying substantial support
SUMMARY OF THE INVENTION
[0006] To overcome the shortcomings in the art, reduced eccentricity moment guardrail post connector is provided. The reduced eccentricity moment guardrail post connector includes a guardrail post, a rim joist, a joist disposed perpendicularly at an end of the joist, where the guardrail post is disposed perpendicularly on the rim joist and perpendicularly to the joist. The invention further includes a connection element having a tensile force resistant portion and at least one shear resistant portion, where the tensile force resistant portion is connected at about a normal angle to a the shear force resistant portion, and the shear force resistant portion is disposed through the joist and compressively couples the tensile force resistant portion adjacent to the joist providing a reduced eccentricity moment between the tensile force resistant portion and the joist. Additionally, the tensile force resistant portion extends through the rim joist and the guardrail post and compressively couples the guardrail post to the rim joist and the tensile force resistant portion disposed along the joist. The reduced eccentric moment connector further includes a guardrail post coupler disposed at a proximal end of the tensile force resistant portion, where the guardrail post coupler provides the compressive joining of the guardrail post to the rim joist. A joist coupler is disposed at a distal end of the shear resistant portion, and provides the compressive joining of the connector element to a joist. A joist material strengthening element is disposed into the joist at an angle about parallel with the guardrail post, where the tensile force resistant portion resists tensile loads when horizontal forces are imparted on the guardrail post, the shear resistant portion resist shear forces when the horizontal forces are imparted on the post, and the material strengthening element resist tensile loads in the joist.
[0007] In one embodiment of the invention, the connection element includes an angled rod, where the tensile force resistant portion is a proximal portion of the angled rod and the shear force resistant portion is a distal portion of the angled rod. In this embodiment, the shear resistant portion further includes a joist sleeve, where the distal portion of the angled rod is disposed through the joist sleeve and the joist sleeve is disposed through the joist. The joist sleeve can be a tube having a fillet feature inside the tube, where the fillet feature conforms to a bend in the angled rod.
[0008] In another embodiment of the invention, the connection element is an angled plate having the tensile force resistant portion and a rim joist abutting portion, where a proximal end of the tensile force resistant portion is disposed at about a normal angle to the rim joist abutting portion. The current embodiment further includes at least one shear bolt hole disposed near a distal end of the tensile force resistant plate and through the tensile force resistant portion. At least one shear bolt is disposed through the shear bolt hole and through the joist, where the tensile force resistant portion is compressively coupled to the joist by a nut and washer threadably tightened to the shear bolt. A tensile rod channel is disposed in the proximal end of the tensile force resistant portion and through the rim joist abutting portion. Additionally, a tensile force resistant rod is fixedly attached along the tensile rod channel providing a reduced eccentricity moment between the tensile force resistant portion and the joist and extends through the rim joist and the guardrail post for the compressive connection. In one aspect of the current embodiment, the tensile force resistant rod is fixedly attached to the tensile rod channel using connectors selected from a group consisting of welding, treads to nut, and threads to welded threaded element.
[0009] In another embodiment of the invention, the connection element includes a first flat plate, where the first flat plate is the tensile force resistant portion having a tensile force resistant rod channel disposed in a proximal end at least one shear bolt through hole disposed in a distal end, a second flat plate where the second flat plate is a rim joist abutting portion, a tensile force resistant rod, where a distal end of the tensile force resistant rod is fixedly attached to the tensile force resistant rod channel and the second flat plate is disposed at a normal angle along the tensile force resistant rod and at a normal angle to the first flat plate The current embodiment further includes at least one shear bolt disposed through the shear bolt through-hole and through the joist, where the tensile force resistant portion is compressively coupled to the joist by a nut and washer threadably tightened to the shear bolt, and a proximal end of the tensile force resistant rod extends through the rim joist and through the guardrail post, where the guardrail post is compressively coupled to the rim joist by the guardrail post coupler.
[0010] In one aspect of the invention, the guardrail post coupler includes a nut and washer, where the nut fixedly attaches to threads of the tensile force resistant proximal end, and the nut fixedly compresses the washer to the post, whereby compressively joining the post to the rim joist.
[0011] In another aspect of the invention, the joist coupler includes a nut and washer, where the nut fixedly attaches to threads of a distal end of the shear resistant portion, and the nut fixedly compresses the washer to the joist, whereby compressively joining the post to the joist
[0012] In a further aspect of the invention, the joist material strengthening element can be a threaded screw or a nail, where the joist material strengthening element binds the joist material to prevent splitting of the joist material.
[0013] The invention also includes a method of using the reduced eccentricity moment guardrail post connector by providing a deck that includes at least a deck floor, a deck rim joist and a joist, wherein the rim joist is disposed perpendicularly at an end of the joist and the guardrail post is disposed perpendicularly on the rim joist and perpendicularly to the joist. The method further includes providing at least one post for attaching to the rim joist and providing a connection element, where the connection element has a tensile force resistant portion and at least one shear resistant portion, and the tensile force resistant portion is connected at about a normal angle to a the shear force resistant portion, and the shear force resistant portion is disposed through the joist and compressively couples the tensile force resistant portion adjacent to the joist providing a reduced eccentricity moment between the tensile force resistant portion and the joist. The tensile force resistant portion extends through the rim joist and the guardrail post, and compressively couples the guardrail post to the rim joist, where the tensile force resistant portion is disposed along the joist. The method also includes providing a guardrail post coupler disposed at a proximal end of the tensile force resistant portion, where the guardrail post coupler provides the compressive joining of the guardrail post to the rim joist, and providing a joist coupler disposed at a distal end of the shear resistant portion, where the joist coupler provides the compressive joining of the connector element to a joist. The method also includes providing a joist material strengthening element disposed into the joist at an angle about parallel with the guardrail post, where the tensile force resistant portion resists tensile loads when horizontal forces are imparted on the guardrail post, the shear resistant portion resist shear forces when the horizontal forces are imparted on the post, and the material strengthening element resist tensile loads in the joist.
BRIEF DESCRIPTION OF THE FIGURES
[0014] The objectives and advantages of the present invention will be understood by reading the following detailed description in conjunction with the drawing, in which:
[0015] FIG. 1 shows an exploded perspective cutaway view of the guardrail post connector according to the present invention.
[0016] FIGS. 2( a )-( b ) show perspective cutaway views of the guardrail post connector according to the present invention.
[0017] FIGS. 3( a )-( d ) show perspective views of different embodiments of the guardrail post connector according to the present invention.
[0018] FIGS. 4( a )-( b ) show planar views of alternative configurations of the guardrail post connector according to the present invention.
[0019] FIG. 5 shows a load-deflection graph of test results for the angled bracket embodiment of FIG. 3( a ) according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will readily appreciate that many variations and alterations to the following exemplary details are within the scope of the invention. Accordingly, the following preferred embodiment of the invention is set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
[0021] A device enabling easy and correct assembly of deck railing posts to a deck base while supplying substantial support is provided. A method of fabricating the device is disclosed.
[0022] FIG. 1 shows an exploded perspective cutaway view of the guardrail post connector assembly 100 according to one embodiment of the current invention. This embodiment includes a connector rod 102 having a shear connection section 104 and a tension connection section 106 , where the tension connection section 106 is disposed at approximately a normal angle to the shear connection section 104 . The connector rod 102 has a shaped shear sleeve 108 disposed about the shear connection section 104 . The connector rod 102 further has a threaded proximal end 110 and a threaded distal 112 , where the proximal end 110 is fitted through a rim joist 114 and through a guardrail post 116 then secured thereto using a threaded nut 118 and washer 120 . Additionally, the distal end 112 and shear sleeve 108 are fitted through a joist 122 , where the washer 120 and threaded nut 118 are assembled to the threaded distal end 112 of the rod 102 . At least one joist material strengthening element 124 is input to the joist 122 at an angle that is normal to both the shear connection section 104 and the tension connection section 106 , where the joist material strengthening element 124 supplements the strength of a region of the joist 122 around the shear sleeve 108 and shear connection section 104 .
[0023] The diameter and length of the connector rod in combination with the location of the joist holes 126 and the material strengthening element 124 are specifically made to guide the location of the shear connection section 104 so the connection will provide adequate strength. The strength of the post to deck framing connection will be determined by the diameter of the connector rod 102 , the length of the connector rod 102 and the location of the holes 126 and the use of material strengthening elements 124 in the joist 122 . The device incorporates the strength needed to meet the requirements of the building code with economy by adjusting these dimensions.
[0024] The addition of the material strengthening elements 124 enables the hole 126 to be placed closer to the top and/or bottom of the joist 122 so that greater leverage and capacity results. The current state of the art require a distance from the top and/or the bottom of the joist 122 to the hole 122 to avoid material failure and breaking.
[0025] FIGS. 2( a )-((b) show perspective cutaway views of the guardrail post connector assembly 100 according to the embodiment shown in FIG. 1 . As shown in FIG. 2( a ), the connection rod 102 is inserted through the shear sleeve 108 (not shown) and the post 116 is secured to the rim joist 114 , and the material strengthening element 124 is shown incorporated in the top of the joist 122 . As shown in FIG. 2( b ), the threaded proximal end 110 of the connection rod 102 is inserted through the joist 122 and secured using the threaded nut 118 and washer 120 . The distal end 112 of the connection rod 102 is inserted through the rim joist 114 and guardrail post 116 and secured using the threaded nut 118 and washer 120 . The material strengthening element 124 is shown incorporated in the bottom of the joist 122 . It should be apparent that the size and shape of the washer 120 provides different advantages in strength and appearance, where a large circular shape or large square shape improves connection strength of the guardrail post 116 .
[0026] FIGS. 3( a )-( d ) show perspective views of some embodiments of the guardrail post connector 300 , with the post 116 , rim joist 114 , and joist 122 removed for illustrative purposes. According to FIGS. 3( a )-( c ), the embodiments include a connection element or connector plate 302 having a generally planar shear connection section 304 and a generally planar tension connection section 306 , where a distal end of the tension connection section 306 is disposed at approximately a normal angle to the shear connection section 304 proximal end. The connector plate 302 has at least one shear bolt 308 disposed through the tension connection section 306 . The shear bolt 308 inserts through the joist (not shown) to provide shear resistance when horizontal forces are exerted on the guardrail post (not shown). The connector plate 302 further has a connector rod receiving channel 310 disposed through the wall of the tension connection section 304 and through the wall of the shear connection section 302 . A connector rod 312 having a proximal end 314 and a distal end 316 is fixedly attached to the rod receiving channel 310 , where the proximal end 314 is fitted to the channel and secured thereto. Further shown is at least one material strengthening element 124 disposed in the joist (not shown) perpendicular to the shear bolt 308 and perpendicular to the connector rod 312 , where the number of material strengthening elements used is related to the required strengthening of the joist material.
[0027] Referring to FIG. 3( a ), the connector plate 302 is shown with a threaded mounting element 318 connected to the rod receiving channel 310 , by welding 320 for example, and the connection rod 312 is a threaded bolt having threads at the proximal end 314 and a bolt head at the distal end 316 , with the threaded proximal end 314 inserted to the threaded mounting element 318 .
[0028] Referring to FIG. 3( b ), the connector plate 302 is shown with a connection rod 312 that is threaded at the distal end 316 and unthreaded at the proximal end 314 , where the unthreaded proximal end is connected to the rod receiving channel 310 , by welding 320 for example. The guardrail post (not shown) is secured to the rim joist (not shown) when the nut 120 and washer 118 are tightened at the distal end 316 of the connection rod 312 .
[0029] Referring to FIG. 3( c ), the connector plate 302 is shown with a shear connection section 304 incorporated with the connection rod 312 , by welding for example, and the connection rod 312 that is threaded at the distal end 316 and unthreaded at the proximal end 314 , where the unthreaded proximal end is connected to the rod receiving channel 310 , by welding 320 for example. The guardrail post (not shown) is secured to the rim joist (not shown) when the nut 120 and washer 118 are tightened at the distal end 316 of the connection rod 312 .
[0030] FIG. 3( d ) shows the guardrail post assembly of the apparatus in FIG. 1 , with the post 116 , rim joist 116 , and joist 122 removed for illustrative purposes. The connection rod 102 is inserted through the shear sleeve 108 and the material strengthening element 124 is incorporated in the top of the joist 122 (not shown). The shear sleeve has a rounded feature 322 for conforming to a the bending shape of the connection rod 106 . Also shown, the threaded proximal end 110 of the connection rod 102 is secured using the threaded nut 118 and washer 120 . The distal end 112 of the connection rod 102 is secured using the threaded nut 118 and washer 120 . The material strengthening elements 124 are incorporated in the joist 122 .
[0031] FIG. 4( a )-( b ) show planar views of alternative configurations of the guardrail post connector according to the present invention. FIG. 4( a ) shows one configuration where two of the systems 300 described in FIG. 3( a ) are used to secure the guardrail post 116 . The configuration shown here shows the capacity to resist applied force (F) from both the inward and outward directions. FIG. 4( b ) shows another configuration where one of the systems 300 described in FIG. 3( a ) is used to secure the guardrail post 116 , and a-bolt assembly 404 is used as a bottom connection of the guardrail post 116 . The configuration shown here shows the capacity to resist applied force (F) from the outward direction.
[0032] The inventor has performed controlled tests to verify the strength of the guardrail post connection meets structural code criteria. FIG. 5 shows a load-deflection graph 500 of test results for the angled bracket embodiment of FIG. 3( a ) according to the present invention. A horizontal load was applied to the top region of the post and the post deflection was measured. The graph shows the integrity of the connection remains until approximately 530 pounds of horizontal force at almost 7-inches of deflection.
[0033] As method of fabricating the guardrail post connector, FIGS. 3( a ) and 3 ( b ) provide an exemplary methods that includes fabricating the connector plate from a sheet of steel or the like, where at least one shear bolt hole and at least one rod receiving channel are disposed through the connector plate using stamping, cutting or machining techniques. Alternately, at least one shear hole and at least one threaded mounting element receiving channel are disposed through the connector plate using stamping, cutting or machining techniques. The connector plate is bent along the rod receiving or threaded mounting element receiving channel region and transverse to the plate length, at approximately a right angle. The receiving channel is made to span from along the tension connection section to along the shear connection section such that the receiving channel follows the bend in the connector plate. The rod having a proximal end and a threaded distal end is fixedly attached to the rod receiving channel, where the proximal end is fitted to the channel and secured thereto using welding techniques or the like. A washer and threaded nut are assembled to the threaded distal end of the rod. Alternately, the threaded mounting element is fixedly attached to the mounting element receiving channel so a bolt with a washer can be assembled to the coupler nut.
[0034] The width and length of the connector plate in combination with the location of the holes are specifically made to guide the location of the shear bolts so the connection will provide adequate strength. The minimum distance of the first shear bolt from the end of the floor joist is guided by the distance from the normal angle of the connector plate to the first connector plate shear bolt hole and the minimum distance of the shear bolt to the top of the floor joist is guided by the width of the connector plate and the location of the shear bolt hole in the middle of the plate. The distance between the shear bolts is guided by the location of the holes in the connector plate. The strength of the post to deck framing connection will be determined by the width of the connector plate, the length of the connector plate, the location of the holes in the connector plate, and the material strengthening elements. The device incorporates the strength needed to meet the requirements of the building code with economy adding the material strengthening element and by adjusting these dimensions.
[0035] The present invention has now been described in accordance with several exemplary embodiments, which are intended to be illustrative in all aspects, rather than restrictive. Thus, the present invention is capable of many variations in detailed implementation, which may be derived from the description contained herein by a person of ordinary skill in the art. For example, the guardrail post connector can be used to secure one or more rim joists 114 to the joists 122 to allow attachment of the post 116 to the rim joists 114 with bolts 404 or lag screws (not shown) at locations between the joists 122 . Further, the number and size of rim joists 114 , guardrail post connectors 102 , bolts 312 , washers 120 and screws or nails can be adjusted to provide the strength to meet the requirements of the building code with economy by adjusting the number and size.
[0036] Further, dual guardrail post connectors can be used for greater capacity and larger posts by place in one on each side of the joist and bolting through the joist to connect the two guardrail post connectors with a bolt.
[0037] Additionally, strength can be increased by using large washers on the outside of the post to distribute the load force over a wider area.
[0038] All such variations are considered to be within the scope and spirit of the present invention as defined by the following claims and their legal equivalents.
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A reduced eccentricity guardrail post connector is provided and includes a connection element having a tensile force resistant portion and a shear resistant portion, where a proximal end of the shear resistant portion is connected at about a normal angle to a distal end of the tensile force resistant portion. The post connector further includes a post coupler disposed at a proximal end of the tensile force resistant portion, where the post coupler compressively joins a post to a rim joist. Additionally, a joist coupler is disposed at a distal end of the shear resistant portion, where the joist coupler compressively joins the connector element to a joist. Further, a joist material strengthening element is disposed into the joist to resist tensile loads in joist material. The tensile resistant portion resists tensile loads and the shear resistant portion resist shear loads when the horizontal forces are imparted on the post.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending application Ser. No. 948,038, filed Oct. 2, 1978, now abandoned.
DESCRIPTION OF THE INVENTION
Field of the Invention
This invention relates to novel isoquinoline analgesic and narcotic antagonistic compounds, processes for their manufacture, their use in the treatment of pain, and novel cyclohexadiene lactams as intermediates.
BACKGROUND OF THE INVENTION
Pain is an essential sensation in the protection of the body from damaging influences. However, because said pain frequently persists after it has played its essential role, it becomes desirable to treat the subject to reduce the sensation of pain. Drugs which are effective to reduce pain, i.e., analgesics, act by different mechanisms:
(1) Drugs which reduce pain by treating its source, e.g. glyceryl trinitrate in the treatment of angina;
(2) Drugs of the non-narcotic, non-steroidal, antiinflammatory, antipyretic type, which may act in part peripherally to relieve pain by inhibition of prostaglandin synthetase, or an antiinflammatory effect, e.g. aspirin or acetaminophen; and
(3) Drugs which act mainly on the perception of pain by the brain, e.g. morphine and certain morphine derivatives.
Analgescis are also classified by their mode of use. Thus, in general, when the intensity of pain is mild to moderate, a simple (mild) analgesic is given. However, when the pain is moderate to severe, a strong analgesic is indicated.
The most important strong analgesic compounds include opium preparations, purified alkaloids (morphine), semi-synthetic morphine modifications (oxymorphone) and various synthetic morphine-like compounds (phenyl piperidino structures). In addition to morphine itself, the most widely-used analgesics are oxycodone, oxymorphone, levorphanol, methadone and pethidine (meperidine). Morphine is the standard by which strong analgesics are compared.
Morphine, which acts on the central nervous system to repress pain perception, causes drowsiness, euphoria (and sometimes disphoria) and depresses respiration. Morphine and the many drugs related thereto incur high degrees of dependence. This is, of course, no problem in short-term treatment of pain, but becomes a serious problem in the treatment of chronic pain.
Because the narcotic-like analgesics also act to depress the respiratory system, over dosage of such compounds is extremely dangerous. It has been found, however, that several N-allyl derivatives, including the N-allyl derivative of morphine (nalorphine), levorphanol (levallorphan) and oxymorphone (naloxone) effectively antagonize overdoses of the opiate analgesics. Two of these, nalorphine and levallorphan, have some analgesic effects by themselves, but naloxone is a pure antagonist having no intrinsic analgesic activity. Naloxone is a versatile material which is capable of reversing the action (including the analgesia) of larger doses of a narcotic and also antagonizes the emetic effect of meperidine. Though such antagonists have been shown to be effective in antagonizing overdoses of narcotics, they have not been shown to be effective in administration with narcotics to reverse respiratory depression without also reversing the desirable analgesic effects of the opiate. Thus, it would be highly desirable to obtain a compound which combines significant narcotic analgesic activity as well as narcotic antagonistic activity into the same molecule.
Since Lasagna and Beecher (Lasagna, L. and Beecher, H. K.: The Analgesic Effectiveness of Nalorphine and Nalorphine-Morphine Combinations in Man. J. Pharmacol. Exp. Ther. 112: 356-363, 1954.) reported that the narcotic antagonist nalorphine also has analgetic properties in man, a wide-ranging search for agonist/antagonist compounds possessing both analgetic and narcotic antagonist properties has led to the discovery of a number of clinically useful agents (pentazocine, cyclazocine, nalbuphine, etc.) having a lower abuse potential than pure narcotic agonist compounds. Generally (but with some exceptions), substitution of C 2 to C n homologs for the N-methyl group in morphine, codeine, and other narcotics produces compounds possessing an antagonist component with or without loss of analgetic potency; thus within a single chemical series there may be compounds possessing pure agonist, combined agonist/antagonist, and pure antagonist properties (Jaffe, J. H. and Martin, W. R.: Narcotic Analgesics and Antagonists, in "The Pharmacological Basis of Therapeutics," L. S. Goodman and A. Gilman (eds), Macmillan Publishing Co., Inc., New York, p. 272, 1975.)
U.S. Pat. No. 3,015,661 to Georgian is directed to decahydroisoquinoline derivatives such as those corresponding to the structure ##STR3## Examples of such compounds are 3-acetyl-1,2,3,4,4a5,6,7-octahydropyrido[3,4-d]-4aH-isocarbazole and the corresponding 9-methoxy analog. This class of compounds is disclosed to be useful as intermediates for the preparation of natural alkaloids and hydrocarbazolenines.
More clearly of interest is the work of Schultz et al., which is directed to the preparation of morphine--Schultz, A. G. and Lucci, R. D., J. C. S. Chem. Comm., 925 (1976); and Schultz, A. G., Lucci, R. D., Fu, W. Y., Berger, M. H., Erhardt, S., and Hagmann, W. K., J. Am. Chem. Soc., 100, 2150 (1978). Both of the papers by Schultz et al. describe the following reaction: ##STR4##
The compound having having a cis-fused dihydrofuran structure is disclosed to be useful as an intermediate for the synthesis of morphine alkaloids in that it has the functionality necessary for formation of the remaining carbon-carbon bond in the morphine alkaloids.
SUMMARY OF THE INVENTION
The invention is primarily directed to a novel class of octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline compounds corresponding to the following formula: ##STR5## wherein
R 1 is selected from the group consisting of --H, C 1-10 alkyl, --CH 2 --R 6 , ##STR6## and (CH 2 ) n CN in which n=1-3;
R 2 is selected from the group consisting of --H, --OH, C 1-2 alkoxy and C 2-12 acyloxy of an alkanoic acid;
R 3 is separately selected from the group consisting of --H, --OH, --CH 3 , C 1-2 alkoxy, C 2-12 acyloxy of an alkanoic acid, --F and --N 3 ;
R 4 is separately selected from the group consisting of --H and --F;
R 3-4 in combination are selected from the group consisting of methylene and keto;
R 5 is selected from the group consisting of --H, --OH, ##STR7## and --OCH 3 ;
R 6 is selected from the group consisting of ##STR8## --C.tbd.CH, C 3-6 cycloalkyl, 2-thienyl, 2-furyl and 2-tetrahydrofuryl, the 2-furyl and 2-tetrahydrofuryl optionally substituted with a methyl group;
R 7 is selected from the group consisting of C 1-3 alkyl, --OCH 3 , --Cl, --Br and --F; and
R 8 and R 9 are independently selected from the group consisting of --H, --CH 3 and --Cl; and pharmaceutically suitable acid addition salts thereof.
The invention is also directed to pharmaceutical compositions containing the above-described compounds and to the method of using them for the treatment of pain and to antagonize the effects of narcotics. In another aspect of the invention, it is directed to novel intermediate compounds which are useful to make the primary compounds and to the method of making those intermediates.
DETAILED DESCRIPTION OF THE INVENTION
Within the context of the general formula of the octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolines of the invention given hereinabove, it has been found that certain structural variations are preferred because of the indication of greater analgesic and/or narcotic antagonistic effectiveness.
The preferred compounds of the invention are those in which independently
(a) R 1 is C 1-6 alkyl or cyclopropylmethyl, of which cyclopropylmethyl and C 1-4 alkyl are most preferred;
(b) R 2 is --OH or --OCH 3 , of which --OH is most preferred;
(c) R 3 and R 4 are both --H; R 3 is --OH and R 4 is --H; R 3 and R 4 are both --F; and R 3 and R 4 together form a keto group, most preferred of which is when R 3 and R 4 are both --H;
(d) R 5 is --H or --OH of which --H is most preferred.
The most preferred compound is 3-cyclopropylmethyl-1,2,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]-isoquinolin-9-ol.
General Reaction Sequence
The compounds of the invention are synthesized by the following general sequence of reactions: ##STR9## Process Conditions
(1) Wittig Reaction
This first reaction of the process sequence is conducted in a non-aqueous system in the liquid phase at a temperature of 80°-160° C. A temperature of at least about 110° C. is preferred in order to get a satisfactorily fast rate of reaction. A slight excess of the phosphorane reactant is utilized to drive the reaction to completion. Upon completion of the reaction, the system is boiled with strong base to convert the ester to the acid salt, which mixture is then extracted with methylene chloride to remove the triphenylphosphine oxide. The resultant water layer is acidified to convert the salt to the acid.
(2) Metal Hydride Reduction
The acidic product of the Wittig reaction can be reduced to the alcohol (I) by reduction with any complexed metal hydride, such as LiAlH 4 or with BH 3 .(CH 3 ) 2 S or BH 3 .tetrahydrofuran. The highly exothermic reaction is conducted as a non-aqueous system in the liquid phase at a temperature of 0°-30° C. Borane is preferred in the complex because it is both inexpensive and easy to handle safely. It is preferred to use a slight excess of reagent complex in order to assure complete reaction. The reduced product can be easily recovered by extracting the reaction product with methylene chloride and distilling off the solvent from the extract under a high vacuum.
(3) Reaction with p-toluenesulfonyl chloride
This reaction is carried out at low temperature (0°-30° C.) to avoid decomposition of the reaction product, using as solvent for the system a basic compound which will also remove byproduct HCl as it is formed. Suitable solvents include pyridine, substituted pyridines, isoquinoline and the like. The reaction sometimes is completed in a few minutes but may require several days when kept in a refrigerator.
(4) Amine Substitution
Using crude product from reaction (3), a large excess of alkylamine (R 1 NH 2 ) is added to avoid the formation of tertiary amide byproducts and other side reactions. The reaction is carried out under pressure to contain the reaction at a temperature of 50°-150° C. In general, the reaction time is reduced by operating at the higher temperatures.
(5) Amide Preparation
The amine reaction product of step (4) is converted to the desired α-pyronecarboxamide by reaction at 0°-30° C. in the liquid phase with the reaction product of a mixture of either 3- or 6-α-pyronecarboxylic acid and thionyl chloride, in an inert solvent system. Suitable solvents are non-alcoholic solvents, such as tetrahydrofuran, toluene and methylene chloride. Pyridine is also used in the reaction system to render the system basic and to take up HCl as it is formed and avoid the consumption of amine starting material. It is preferred to use a slight excess of the pyrone acid chloride to obtain a more favorable reaction rate. Unreacted pyrone acid chloride reactant is removed from the reaction product by base extraction.
(6) Intramolecular Diels-Alder Reaction
This novel reaction step is carried out by maintaining the α-pyronecarboxamide reaction product of step (5) at a temperature of 150°-500° C. for a time sufficient to obtain substantial Diels-Alder reaction without incurring thermal degradation of either the reactant or the resultant reaction product. This, shorter reaction times must be used at higher temperatures to avoid such decomposition. The reaction can be carried out in either the liquid or vapor phase. When carried out in the liquid phase, the reactant is preferably dissolved in an inert solvent, such as aromatic hydrocarbons, chlorinated aromatic hydrocarbons and aliphatic or aromatic ethers. At preferred reaction temperatures of 150°-300° C., the liquid phase reaction can be carried out in as little as about one minute or over the course of several weeks. To avoid yield loss due to polymerization of the reactant, the reaction may be carried out in an evacuated steel or glass vessel after the reactant and/or reactant solution has been thoroughly degassed. Undesirable polymerization of the reactant can also be reduced by the presence of a free radical polymerization inhibitor, such as phenothiazine. It is preferred to carry out the reaction by refluxing a dilute (about 0.5-1% by weight) solution in 1,2,4-trichlorobenzene under nitrogen for a time sufficient to obtain substantial Diels-Alder product. The reaction time for this preferred method depends on the nature of the substituent R 1 . The reaction can also be carried out by distilling the reactant at a temperature of 300°-500° C. under vacuum through a heat exchange medium such as a hot quartz tube packed with quartz chips.
(7) Reduction of Cyclohexadiene Ring
The cyclohexadiene ring of the reaction product of step (6) is reduced to saturation by conventional catalytic hydrogenation in the liquid phase at 20°-100° C. Conventional hydrogenation catalysts can be used such as Raney nickel, platinum, palladium, any of which can be supported on suitable carriers. The reaction is carried out with an excess of hydrogen and at comparatively mild conditions of temperature and pressure in order to reduce only the hexadiene ring and to avoid reduction of the benzene ring.
(8) Reduction of Lactam to Amine
Like reaction (2), reduction of the lactam intermediate product to the amine involves use of a complex metal hydride, such as LiAlH 4 or with BH 3 . (CH 3 ) 2 S or BH 3 .tetrahydrofuran. To obtain a satisfactorily rapid reaction rate, the reaction should be carried out in the liquid phase at a temperature of at least about 50° C. A preferred method of carrying out the reaction is with solvent reflux. Thus, the reaction is effected at essentially the boiling point of the solvent. When a metal hydride complex, such as BH 3 /tetrahydrofuran/methyl sulfide is used, the complex is decomposed upon completion of the reaction by heating the reaction system with acid, preferably an organic acid such as acetic acid.
In one variation of the above-described reaction sequence, which is useful when R 1 is hydrogen, by replacing the carbomethoxymethylenetriphenylphosphorane with cyanomethyleenetriphenylphosphorane, and reaction product of step (1) can be reduced directly with LiAlH 4 to reaction product (II), thus avoiding reactions (3) and (4). The amine (II, R 1 =H) can be converted to a secondary amine by alkylation or acrylation followed by reduction (see Example 4b): ##STR10##
The following table shows representative compounds readily available by the above processes and whose specific description follows.
__________________________________________________________________________ ##STR11##R.sub.1 R.sub.2 R.sub.3 R.sub.4 R.sub.5__________________________________________________________________________CH.sub.3 H H H HCH.sub.3 OCH.sub.3 H H HCH.sub.3 OH H H H ##STR12## OCH.sub.3 H H H ##STR13## OH H H H ##STR14## OCH.sub.3 H H H ##STR15## OH H H HCH.sub.2 CH.sub.2 CH.sub.3 OH H H H ##STR16## OH H H H ##STR17## OCH.sub.3 H H H ##STR18## OH H H H ##STR19## OC.sub.2 H.sub.5 H H HH OCH.sub.3 H H HH OC.sub.2 H.sub.5 H H HCH.sub.2 CHCH.sub.2 OCH.sub.3 H H H ##STR20## OCH.sub.3 H H H ##STR21## OCH.sub.3 H H HCH.sub.2 CH.sub.2 CN OCH.sub.3 H H HCH.sub.3 OC.sub.2 H.sub.5 H H H ##STR22## OCOC.sub.3 H.sub.7 H H H ##STR23## OCH.sub.3 OH H H ##STR24## OCH.sub.3 OCOCH.sub.7 H H ##STR25## OCH.sub.3 F H H ##STR26## OCH.sub.3 N.sub.3 H H ##STR27## OCH.sub.3 R.sub.3 + R.sub.4 = O H ##STR28## OCH.sub.3 CH.sub.3 H H ##STR29## OCH.sub.3 F F H ##STR30## OCH.sub.3 OH H OH ##STR31## OCH.sub.3 H H OH(CH.sub.2).sub.5 CH.sub.3 OCOCH.sub.3 H H OCOCH.sub.3CH(CH.sub.3)CH.sub.2 CH.sub.3 OCO(CH.sub.2).sub.10 CH.sub.3 H H HCH.sub.2 CN OCH.sub.3 H H H(CH.sub.2).sub.3 CN OCH.sub.3 H H H ##STR32## OCH.sub.3 H H H ##STR33## OCH.sub.3 H H HCH.sub.2 CHC(CH.sub.3).sub.2 OCH.sub.3 H H HCH.sub.2 CHCCl.sub.2 OCH.sub.3 H H HCH.sub.2 CHCHCH.sub.3 OCH.sub.3 H H HCH.sub.2CCH OCH.sub.3 H H H ##STR34## OCH.sub.3 OCH.sub.3 H OCH.sub.3 ##STR35## OCH.sub.3 OC.sub.2 H.sub.5 H H ##STR36## OCH.sub.3 OCO(CH.sub.2).sub.10 CH.sub.3 H H ##STR37## OCH.sub.3 R.sub.3 + R.sub.4 = CH.sub.2 H__________________________________________________________________________
The compounds of the invention, their use and the process for making them will be better understood by reference to the following examples, in which all indications of percentage are by weight unless indicated otherwise and temperatures are in degree Celsius. The compounds of the examples have the trans rather than the cis configuration, corresponding to that determined for the product of Example 5.
In these molecules d and l optical isomers occur as racemic mixtures which can be resolved by known methods (Eliel, Stereochemistry of Carbon Compounds, McGraw-Hill, 1962, p. 21). The optical isomers corresponding to the absolute configuration of morphine are more active and preferred. Similarly, where compounds carry a 7-hydroxyl group, the β-isomers, having the same stereochemistry relative to the furan ring as in morphine, are preferred.
EXAMPLES
EXAMPLE 1
3-Methyl-2,3,4,4aα,5,6,7,7aα,octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =Me; R 2 =H)
(a) 3-Benzofuranethanol (I; R 2 =H)
A mixture of 71.1 g of 3-benzofuranone [D. C. Schroeder, P. O. Corcoran, C. A. Holden, and M. C. Mulligan, J. Org. Chem., 27, 586 (1962)], 210 g of carbomethoxymethylenetriphenylphsophorane and 300 ml of toluene was heated under reflux for 8 hours. The solvent was removed and the residue stirred with ether and filtered. The filtrate was concentrated and the residue heated under reflux with 300 ml of methanol and 300 ml of 15% sodium hydroxide solution for 2 hours. The cooled mixture was diluted with water and extracted several times with methylene chloride. Acidification of the water layer and extraction with methylene chloride gave 88.3 g of crude 3-benzofuranacetic acid. The product was dissolved in 500 ml of tetrahydrofuran, and 50 g of borane-methyl sulfide complex added. After stirring at room temperature overnight, the excess reagent was destroyed by slow addition of 100 ml of conc. hydrochloric acid. The mixture was made basic and extracted several times with methylene chloride and the product shortpath distilled (bath temperature) 110°, 1 micron pressure) to give 65.8 g (76%) of 3-benzofuranethanol. NMR spectrum (in CDCl 3 ): τ2.3-3.0 (m, 5); 6.2 (t, J=6 Hz, 2) 7.1 (t, J=6 Hz, 2) and 7.3 (s, 1).
(b) N-Methyl-3-benzofuranethylamine (II, R 1 =Me, R 2 =H)
A solution of 5.03 g of 3-benzofuranethanol and 8 g of p-toluenesulfonyl chloride in 20 ml of pyridine was kept in a refrigerator for one week. Most of the pyridine was removed under vacuum, and the residue dissolved in ether and washed successively with 5% hydrochloric acid, water, and 5% sodium bicarbonate solution and dried. Removal of the solvent left 5.93 g of crude 3-benzofuranethanol, p-toluenesulfonate which was heated with 8 g of methylamine in 25 ml of tetrahydrofuran to 100° for 4 hours. The mixture was concentrated, made basic with aqueous sodium hydroxide, and extracted with methylene chloride. The crude amine so obtained was short-path distilled (bath 120°, 0.5 micron) to give 3.17 g (59% yield) of N-methyl 3-benzofuranethylamine. NMR spectrum (in CDCl 3 ): τ2.4-3.0 (m, 5); 7.2 (s, 4); 7.6 (s, 3) and 9.0 (s, 1).
(c) N-(3-Benzofuranethyl)-N-methyl-6-α-pyronecarboxamide (III, R 1 =Me; R 2 =H)
A mixture of 1.05 g of 6-α-pyronecarboxylic acid [R. H. Wiley and A. J. Hart, J. Am. Chem. Soc., 76, 1942 (1954)], 7 ml of thionyl chloride and one drop of dimethylformamide was heated under reflux for twenty minutes. The excess reagent was removed under vacuum, the residue dissolved in toluene, and the solvent removed under vacuum. The residue (6-pyronecarbonyl chloride) was dissolved in 3 ml of methylene chloride and the solution added slowly to a stirred mixture of 1.34 g of N-methyl-3-benzofuranethylamine, 2 ml of pyridine, and 3 ml of methylene chloride, keeping the temperature below 20°. The mixture was stirred at room temperature for one hour, toluene added, and the toluene solution successively washed with 10% hydrochloric acid, water, and 5% sodium bicarbonate solution. Removal of the solvent gave 2.04 g (91% yield) of III (R 1 =Me; R 2 =H); nmr spectrum (in CDCl 3 ): τ2.2-4.0 (m, 8); 6.3 (t, J=7 Hz, split further, 2); 7.0 (s, 3), and 7.1 (t, J=7 Hz, split further, 2).
(d) 3-Methyl-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]-isoquinolin-4[7aH]-one (IV; R 1 =Me; R 2 =H)
A deoxygenated solution of 1.72 g of III (R 1 =Me, R 2 =H) in 50 ml of toluene, contained in an evacuated sealed glass tube, was heated to 225° for 8 hours. Removal of the solvent and crystallization of the residue from toluene gave 0.66 g of IV (R 1 =Me; R 2 =H) containing ca. 20% impurities (part of which is toluene). 220 MHz nmr spectrum (in CDCl 3 ): τ2.5-3.5 (m+d, J=6 Hz, 5); 4.0 (d/d/d,J=10/6/2/ Hz, 1); 4.2 (d/d, J=10/3 Hz, 1); 4.6 (narrow t, J˜2 Hz, 1); 6.5 (t/d, J=13/4 Hz, 1); 6.8 (d/d/d, J=13/6/2 Hz, 1); 6.9 (s, 3); 7.8 (t/d, J=13/6 Hz, 1) and 8.1 (d/d/d, J=13/4/2 Hz, 1).
(e) 3-Methyl-2,3,5,6,7,7a α-hexahydro-1H-benzo[4,5]furo-[3,2-e]isoquinolin-4[4aαH]-one (V; R 1 =Me; R 2 =H)
A solution of 0.76 g of IV (R 1 =Me; R 2 =H) in tetrahydrofuran was stirred under hydrogen in the presence of a palladium-on-charcoal catalyst until saturation of the two double bonds was complete. Removal of the solvent from the filtered mixture gave 0.72 g of V (R 1 =Me; R 2 =H) of ca. 90% purity; 220 MHz nmr spectrum (in CDCl 3 ): τ2.8-3.3 (m, 4); 5.6 (d/d, J=8/6 Hz, 1); 7.1 (s, 3) and 6.5-8.9 (m, 11).
(f) 3-Methyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo-[4,5]furo[3,2-e]isoquinoline (VI, R 1 =Me, R 2 =H)
A mixture of 0.72 g of crude V (R 1 =Me; R 2 =H), 7 ml of tetrahydrofuran and 0.7 ml borane-methyl sulfide complex was heated under reflux overnight. Excess borane was destroyed by slow addition of conc. hydrochloric acid to the cooled mixture which was then made basic and extracted with methylene chloride. The product obtained on removal of the solvent was heated under reflux with 5 ml of acetic acid for 5 hours. The product was partitioned into neutral and basic fractions with toluene and dilute hydrochloric acid and the basic fraction, recovered from the acid solution with sodium hydroxide and methylene chloride, sublimed (0.5 micron, 120°-140° bath temperature) to give 0.24 g of VI (R 1 =Me; R 2 =H); 220 MHz nmr spectrum (in CDCl 3 ): τ2.6 (d/d, J=8/2 Hz, 1); 2.9 (t/d, 8/2 Hz, 1); 3.2 (m, 2); 5.7 (skewed triplet, J≈5 Hz); 7.7 (s, 3) and 7-9 (m, 13).
EXAMPLE 2
9-Methoxy-3-methyl-2,3,4,4aα-5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI; R 1 =Me; R 2 =OMe)
(a) 7-Methoxy-3-benzofuranethanol (I; R 2 =MeO)
7-Methoxy-3-benzofuranone (prepared from methyl o-vanillate according to the literature procedure cited in Example 1(a) was converted to 7-methoxy-3-benzofuranethanol as described in Example Ia. The product, obtained in 79% overall yield after short-path distillation (140°-180° bath temperature, 0.5 micron pressure), had the following nmr spectrum (in CDCl 3 ): 2.7 (narrow m, 1); 3.1-3.6 (m, 3); 6.2-6.6 (s+t, J=6.5 Hz, +broad s, 6) and 7.4 (t, J=6.5 Hz, 2).
(b) 7-Methoxy-N-methyl-3-benzofuranethylamine (II, R 1 =Me; R 2 =MeO) was obtained in 75% overall yield from 7-methoxy-3-benzofuranethanol as described in Example 1b; nmr spectrum (in CDCl 3 ): τ2.3 (narrow m, 1); 2.5-3.1 (m, 3); 5.8 (s, 3); 6.9 (narrow m, 4); 7.3 (s, 3) and 8.0 (s, 1).
(c) 9-Methoxy-3-methyl-2,3-dihydro-1H-benzo[4,5]-furo[3,2-e]isoquinolin-4[7aH]-one (IV, R 1 =Me; R 2 =MeO)
7-Methoxy-N-methyl-3-benzofuranethylamine was treated with 6-α-pyronecarbonyl chloride as described in Example 1c and the resulting N-(9-methoxy-3-benzofuranethyl), N-methyl-6-α-pyronecarboxamide (III, R 1 =Me, R 2 =MeO) heated in toluene solution to 215° for 12 hours as described in Example 1d. Crystallization from toluene gave IV (R 1 =Me; R 2 =MeO) in 20% overall yield, mp 175°-176° after drying at 110°/1 micron. 220 MHz nmr spectrum (in CDCl 3 ): τ3.1 (d, J=6 Hz, 1); 3.3-3.5 (m, 2); 3.6 (d/d, J=6.5/2.5 Hz, 1); 4.1 (d/d/d; J=10/6/2 Hz, 1); 4.3 (d/d/, J=10/2 Hz, 1); 4.7 (narrow m, 1); 6.3 (s, 3); 6.6 (t/d, J=12.5/4 Hz, 1); 6.9 (d/d/d; J=12.5/6/2 Hz, 1); 7.7 (s, 3); 8.0 (t/d, J=12.5/6 Hz, 1); and 8.3 (d/d/d; J=12.5/4/2 Hz).
Anal. Calcd. for C 17 H 17 NO 3 : C, 72.06; H, 6.05; N, 4.94. Found: C, 71.60; H, 5.98; N, 4.90.
(d) 9-Methoxy-3-methyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =Me; R 2 =MeO)
Following the procedure of Example 1, 9-methoxy-3-methyl-2,3,5,6,7,7aα-hexahydro-1H-benzo[4,5]furo[3,2-e]-isoquinolin-4[4aαH]-one (VI, R 1 =Me; R 2 =MeO) was obtained by catalytic hydrogenation of IV (R 1 =Me; R 2 =MeO); 220 MHz nmr spectrum (in CDCl 3 ): 2.9-3.1 (m, 2); 3.2-3.4 (m, 1); 5.3 (d/d, J=8/6 Hz, 1); 5.9 (s, 3); 6.8 (s, 3) and 6.4-8.7 (m, 11); the spectrum also indicated the presence of ca. 10% of an impurity. Reduction with borane-methyl sulfide as described in Example 1f gave VI (R 1 =Me, R 2 =MeO) in 69% overall yield after sublimation (160° bath temperature, 0.5 micron pressure), mp 63°-64°. Mass spectrum: m/e calcd. 273.1728; found: 273.1716. 220 MHz nmr spectrum (in CDCl 3 ): τ2.9 (m, 1); 3.3 (m, 2); 5.6 (t, J=5.5 Hz, 1); 6.2 (s, 3); 7.6 (s, 3) and 6.2-9.0 (m, 13); the spectrum also indicated the presence of ca. 10% of an impurity.
Anal. Calcd. for C 17 H 23 NO 2 : C, 74.69; H, 8.48; N, 5.12. Found: C, 74.79; H, 8.30; N, 5.40.
EXAMPLE 3
3-Methyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI, R 1 =Me; R 2 =OH)
A mixture of 1.09 g of VI (R 1 =OMe, R 2 =Me; Example 2(d) and 2.3 g of pyridine hydrochloride was stirred in an oil bath, kept at 190° for 4 hours. The cooled mixture was stirred with aqueous sodium carbonate solution and methylene chloride, the organic phase dried and the residue left after removal of the solvent crystallized from 15 ml of 95% ethanol to give 0.60 g (58% yield) of VI (R 1 =Me; R 2 =OH), mp 218°-220°. Mass spectrum: m/e calcd. 259.1572; found: 259.1561.
Anal. Calcd. for C 16 H 21 NO 2 : C, 74.10; H, 8.16; N, 5.40. Found: C, 74.28; H, 7.93; N, 5.63.
Addition of 8.60 g of VI (R 1 =Me; R 2 =H) to a boiling solution of 12.82 g of d-dibenzoyltartaric acid in 100 ml of ethanol gave, after cooling, 4.33 g of a precipitate. It was reconverted to the free base with aqueous sodium carbonate. Crystallization from 90% aqueous ethanol gave the (+) isomer of VI (R 1 =Me; R 2 =H), mp 163°-164°. [α] D =+53.2° (C=1.01 in chloroform). The mother liquors from above were converted to the free base which was then treated with 1-dibenzoyltartaric acid as described above, giving eventually the (-) isomer of VI (R 1 =Me; R 2 =H), mp 163°-164°, [α] D =-51.9°.
EXAMPLE 4
3-Cyclopropylmethyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR38##
(a) 7-Methoxy-3-benzofuranethylamine (II, R 1 =H, R 2 =MeO)
A mixture of 26.7 g of the tosylate of 7-methoxy-3-benzofuranethanol (Example 2a), prepared as described in Example 1b, 300 ml of tetrahydrofuran and 100 g of ammonia was heated in a pressure vessel to 100° for 4 hours. The crude product was partitioned into basic and neutral fractions, and the basic fraction short-path distilled (to 170° bath temperature, 1 micron pressure) to give 11.2 g (76%) of 7-methoxy-3-benzofuranethylamine; nmr spectrum (in CDCl 3 ): τ2.6 (s, 1); 2.9-3.4 (m, 3); 6.1 (s, 3); 6.9-7.5 (m, 4) and 8.9 (s, 2).
(b) N-Cyclopropylmethyl-7-methoxy-3-benzofuranethylamine ##STR39##
To a mixture of 10.27 g of 7-methoxy-3-benzofuranethylamine, 60 ml of methylene chloride, and 60 ml of 15% aqueous sodium hydroxide solution was added, with cooling, 8 ml of cyclopropanecarbonyl chloride. The mixture was stirred at room temperature overnight; an additional 2 ml of cyclopropanecarbonyl chloride added after two hours. The solvent was removed from the dried organic layer and the residue heated under reflux with 3.5 g of lithium aluminum hydride in tetrahydrofuran for 6 hours. Water (3.5 ml), 15% aqueous sodium hydroxide solution (3.5 ml) and finally water (10.5 ml) were added with cooling, and the mixture filtered. Removal of the solvent and short-path distillation of the residue (bath to 170°, 1 micron pressure) gave 11.74 g (90% yield) of N-cyclopropylmethyl-7-methoxy-3-benzofuranethylamine; nmr spectrum (in CDCl 3 ): τ2.6 (s, 1); 2.8-3.4 (m, 3); 6.1 (s, 3); 7.1-7.4 (m, 4 ); 7.6 (d, J=6.5 Hz, 2) and 8.1-10.2 (m, 6).
(c) 3-Cyclopropylmethyl-9-methoxy-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[7aH]-one ##STR40##
A solution of 6-α-pyronecarbonyl chloride, prepared from 43 g of the acid, in 200 ml of methylene chloride was added to a stirred mixture of 71.1 g of N-cyclopropylmethyl-7-methoxy-3-benzofuranethylamine, 100 ml of pyridine and 200 ml of methylene chloride, keeping the temperature below 15°. The mixture was stirred at room temperature for 1 hour, and acidified, keeping the temperature below 20°. Sufficient toluene was added to cause the organic phase to be the upper layer. The layers were separated and the aqueous phase was extracted with toluene. The combined organic phases were washed twice with water and then with 5% aqueous sodium bicarbonate solution. Removal of the solvent from the dried solution gave 104.1 g of amide III ##STR41## which was heated under reflux with 16 liters of 1,2,4-trichlorobenzene under nitrogen for 7 hours. Removal of the solvent and crystallization of the residue from ethyl acetate gave 45.10 g of IV ##STR42## Purification of the mother liquor by high-pressure liquid chromatography (silica gel, hexane-ethyl acetate 1:1) followed by crystallization from ethyl acetate gave an additional 10.85 g of product. Combined yield: 55.95 g (59%). An analytical sample (ethyl acetate) had mp 133°-134°.
Mass spectrum: m/e calcd. 323.1521; Found: 323.1526.
Anal. Calcd. for C 20 H 21 NO 3 : C, 74.29; H, 6.54; N, 4.33. Found: C, 74.16; H, 6.50; N, 4.24.
(d) 3-Cyclopropylmethyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR43##
A solution of 15.21 g of IV ##STR44## in tetrahydrofuran was shaken with 2.84 g of palladium on charcoal (10%) at 50 p.s.i. initial hydrogen pressure for 3.5 days. Removal of the solvent from the filtered solution gave crude V ##STR45## It was heated under reflux with 15 ml of borane-methyl sulfide complex in tetrahydrofuran overnight. The excess borane was destroyed by addition of conc. hydrochloric acid, and the solvent was removed. The residue was made basic with 15% aqueous sodium hydroxide solution and extracted with methylene chloride. The solvent was removed, and the residue was heated under reflux with 60 ml of acetic acid and 20 ml of conc. hydrochloric acid for two hours. The solvents were removed, and the residue was made basic. Extraction with methylene chloride, removal of the solvent from the dried extracts and short-path distillation of the residue (170° bath, 0.5 micron pressure) gave 12.65 g (86% yield) of VI ##STR46## as a viscous oil. Mass spectrum: m/e calcd. 313.2040; found: 313.2045; 220 MHz nmr spectrum (in CDCl 3 ): τ2.7-3.3 (two multiplets, 1 and 2H, respectively); 5.5 (t, J=5.5 Hz, 1); 6.1 (s, 3) and 6.8-10.0 (m, 20).
EXAMPLE 5
3-Cyclopropylmethyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol ##STR47##
A mixture of 28.29 g of VI ##STR48## 300 ml of anhydrous dimethyl formamide, 30 g of potassium t-butoxide and 35 ml of n-propyl mercaptan was stirred under nitrogen in an oil bath at 130° for 5 hours. Acetic acid (30 ml) was added slowly to the cooled mixture, which was then concentrated under vacuum. The residue was stirred with dilute hydrochloric acid and ether, and the acid layer was made basic with aqueous sodium carbonate solution and the precipitate was collected by filtration, washed with water and dried to give 25.46 g of VI, ##STR49## Crystallization of 19.88 g of this product (from another run) from 190 ml of 90% aqueous ethanol gave 12.47 g of pure product, m.p. 175°.
Mass spectrum: m/e calcd. 299.1885; found 299.1880; 220 MHz nmr spectrum (in CDCl 3 ): τ2.5 (broad band, OH; 1); 3.1 (d, J=6 Hz, split further, 1); 3.3 (m, 2); 5.6 (t, J≃5-6 Hz, 1) and 6.6-10.0 (m, 20).
Anal. Calcd. for C 19 H 25 NO 2 : C, 76.22; H, 8.42; N, 4.68. Found: C, 76.15; H, 8.38; N, 4.45.
Crystals of the compound are monoclinic, space group P2 1 .c, with the following unit-cell parameters at 25° C.: a=13.384(3), b=10.083(2), c=24.324(3) A, and β=92.84(1)°. The crystal structure, as determined by an x-ray diffraction study, consists of two independent molecules linked in chains by OH--N hydrogen bonds. The C(12a)-C(12b)-C(4a)-H torsion angles for the two molecules are 172.6 and 175.0°; the configurations about the C(12b)-C(4a) bond is thus trans with respect to the hydrogen on C(4a) and the benzene ring on C(12b).
EXAMPLE 6
3-Cyclobutylmethyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H -benzo[4,5]furo[3,2-e]isoquinoline ##STR50##
(a) N-Cyclobutylmethyl-7-methoxy-3-benzofuranethylamine ##STR51## was prepared as described in Example 4b substituting cyclobutanecarbonyl chloride for cyclopropanecarbonyl chloride; nmr spectrum (in CDCl 3 ): τ2.5-3.4 (m, 4); 6.1 (s, 3) and 7.0-8.7 (m, 14).
(b) 3-Cyclobutylmethyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR52##
Following the procedure of Examples 4c and 4d but omitting purification at the stage of V, 4.13 g of N-cyclobutylmethyl-7-methoxy-3-benzofuranethylamine was converted to 1.27 g (24% overall yield) of VI ##STR53## after short-path distillation (bath to 180°, 1 micron pressure). The 220 MHz nmr spectrum was similar to that of VI ##STR54## except that the cyclobutyl protons occurred at lower field than the cyclopropyl protons; the spectrum indicated the presence of ca. 20% impurities. This material was used without further purification in Example 7.
EXAMPLE 7
3-Cyclobutylmethyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline-9-ol ##STR55##
Following the procedure of Example 3, 1.27 g of crude VI ##STR56## gave 0.67 g (after crystallization from isopropyl alcohol; 55% yield) of VI ##STR57## mp 177°-178°. Mass spectrum: m/e calcd. 313.2040; found 313.2017.
Anal. Calcd. for C 20 H 27 NO 2 : C, 76.64; H, 8.68 N, 4.47. Found: C, 76.89; H, 8.40; N, 4.38.
EXAMPLE 8 ##STR58##
7-Methoxy-3-benzofuranethylamine
A mixture of 14.16 g of 7-methoxy-3-benzofuranone, 39.4 g of cyanomethylenetriphenylphosphorane and 70 ml of p-xylene was heated at reflux under nitrogen for 16 hours. The solvent was removed, the solid washed repeatedly with ether and the product obtained on removal of the solvent from the ether washings sublimed (145° bath, 1 micron). Crystallization of the sublimate from 20 ml of isopropyl alcohol gave 11.06 g (69% yield) of 7-methoxy-3-benzofuranacetonitrile. Nmr spectrum (in CDCl 3 ): τ2.4 (t, J=1-2 Hz, 1); 2.8-3.3 (m, 3); 6.0 (s, 3) and 6.3 (d, J=1-2 Hz, 2).
7-Methoxy-3-benzofuranacetonitrile (10.73 g) was placed in the thimble of a Soxhlet extractor, and the solid extracted into a mechanically stirred mixture of 3.1 g of lithium aluminum hydride and 150 ml of ether during two hrs. After an additional three hrs. at reflux the mixture was cooled and treated successively with 3.1 ml of water, 3.1 ml of 15% sodium hydroxide solution, and 9.3 ml of water. The mixture was filtered and the solid washed repeatedly with ether. The filtrate, on removal of the solvent, gave 10.16 g of product. It was dissolved in toluene and extracted with 2% hydrochloric acid. The extracts were made basic with aqueous sodium hydroxide solution and extracted with methylene chloride. Removal of the solvent and short-path distillation of the residue (to 170° bath temperature, 1 micron) gave 4.33 g (39% yield) of 7-methoxy-3-benzofuranethylamine, identical with the product of Example 4a.
EXAMPLE 9
3-Cyclopropylmethyl-9-acetoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR59##
A mixture of 1.13 g of VI ##STR60## and 7 ml of acetic anhydride was heated under reflux for 40 minutes. Removal of the excess acetic anhydride and short-path distillation of the residue (180°-200° bath temperature; 0.1 micron pressure) gave VI ##STR61## as a viscous oil Nmr spectrum (220 MHz in CDCl 3 ): τ2.6 (d/d, J=7/1 Hz, 1); 3.0 (d/d, J=8/1 Hz, 1); 3.2 (m, 1); 5.5 (t, J≃5.5 Hz, 1) and 6.8-10.0 (m, 23). Mass spectrum: m/e calcd. 341.1989; Found: 341.1976.
EXAMPLE 10
3-Benzyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =CH 2 Ph; R 2 =OMe)
(a) N-Benzyl-7-methoxy-3-benzofuranethylamine (II, R 1 =CH 2 Ph; R 2 =OMe) was prepared in 91% yield as described in Example 4b, substituting benzoyl chloride for cyclopropanecarbonyl chloride; it distilled at 180°-200° bath temperature under 0.5 micron pressure. Nmr spectrum (in CDCl 3 ) τ2.6 (s, 1); 2.7-3.4 (m, 8); 6.1 (s, 3); 6.3 (s, 3); 7.0-7.3 (m, 4) and 8.5 (broad s, 1).
(b) 3-Benzyl-9-methoxy-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[7aH]-one (IV, R 1 =CH 2 Ph; R 2 =OMe)
N-Benzyl-7-methoxy-3-benzofuranethylamine (52.1 g) was treated with 6-α-pyronecarbonyl chloride as described in Example 1c and the resulting amide III (R 1 =CH 2 Ph, R 2 =OMe) was heated under reflux with 12 liters of 1,2,4-trichlorobenzene in an atmosphere of nitrogen for 5 hours. Removal of the solvent and crystallization of the residue from ethyl acetate gave 26.55 g of 3-benzyl-9-methoxy-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinoline-4[7aH]-one. Purification of the mother liquor by high-pressure liquid chromatography (silica gel, ethyl acetate-hexane 1:1) followed by crystallization from ethyl acetate gave another 7.99 g of product. Combined yield: 33.54 g (50%). An analytical sample had mp 135°-136°.
Anal. Calcd. for C 23 H 21 NO 3 : C, 76.86; H, 5.89; N, 3,90. Found: C, 77.13; H, 5.98; N, 3.84.
(c) 3-Benzyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =CH 2 Ph; R 2 =OMe).
A mixture of 17.05 g of IV (R 1 =CH 2 Ph; R 2 =OMe), 100 ml of tetrahydrofuran and 3 g of 10% palladium on charcoal was shaken under 48 psi initial hydrogen pressure at room temperature for 7 days. Removal of the solvent from the filtered solution gave 17.37 g of crude V (R 1 =CH 2 Ph; R 2 =OMe). This was combined with the product from an identical hydrogenation and heated under reflux with 30 ml of borane-methyl sulfide and 200 ml of tetrahydrofuran under nitrogen overnight. The excess borane was decomposed with conc. hydrochloric acid, and the solvent was removed. The residue was made basic with 10% aqueous sodium carbonate solution and the product was extracted into methylene chloride. The residue obtained on removal of the solvent was heated under reflux with 100 ml of acetic acid and 30 ml of conc. hydrochloric acid for two hours. The mixture was concentrated and the residue was made basic with aqueous sodium carbonate solution and extracted with methylene chloride. Removal of the solvent from the dried extracts gave 30.91 g of 3-benzyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline. The product was converted to the hydrochloride salt which after crystallization from isopropyl alcohol melted at 169°-171°.
Anal. Calcd. for C 23 H 28 ClNO 2 : C, 71.58; H, 7.31; N, 3.63. Found: C, 71.81; H, 7.39; N, 3.63.
EXAMPLE 11
3-Benzyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline-9-ol (VI; R 1 =CH 2 Ph; R 2 =OH).
Following the procedure of Example 5, VI (R 1 =CH 2 Ph; R 2 =OMe) was converted to VI (R 1 =CH 2 Ph; R 2 =OH), mp of the hydrochloride: 251°.
Anal. Calcd. for C 22 H 26 ClNO 2 : C, 71.05; H, 7.05; N, 3.77. Found: C, 70.67; H, 7.08; N, 3.68.
EXAMPLE 12
9-Methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =H; R 2 =OMe)
A mixture of 26.8 g of the hydrochloride of VI (R 1 =CH 2 Ph; R 2 =OMe; Example 10c), 100 ml of 90% aqueous ethanol and 2.5 g of 10% palladium on charcoal was shaken under 50 psi initial hydrogen pressure at room temperature until hydrogenolysis was complete. Removal of the solvent from the filtered solution and conversion of the hydrochloride so obtained to the free base with 10% aqueous sodium carbonate and methylene chloride gave 14.8 g of 9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI; R 1 =H; R 2 =OMe). Nmr spectrum (220 MHz in CDCl 3 ): τ2.6-2.8 (m, 1); 3.0-3.2 (m, 2); 5.5 (t, J≃5.5 Hz, 1); 6.1 (s, 3) and 6.5-9.0 (m, 14). Mass spectrum: m/e calculated 259.1572; Found: 259.1580.
EXAMPLE 13
2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI, R 1 =H; R 2 =OH)
A mixture of 1.19 g of VI (R 1 =H; R 2 =OMe; Example 12), 1 g of potassium t-butoxide, 1 ml of n-propyl mercaptan and 20 ml of dimethyl formamide was stirred in an oil bath of 130° under nitrogen for 3 hours. Acetic acid (1 ml) was added to the cooled mixture, and the solvents were removed under vaccum. The residue was made basic with 10% aqueous sodium carbonate solution and the product was extracted into methylene chloride. Removal of the solvent from the dried extracts and crystallization of the residue from 90% aqueous ethanol gave 0.71 g of 9-hydroxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo-[4,5]furo[3,2-e]isoquinoline-3-carboxaldehyde, mp 208°-218°.
Anal. Calcd. for C 16 H 19 NO 3 : C, 70.31; H, 7.01; N, 5.12. Found: C, 70.07; H, 7.06; N, 5.03.
The above product was heated under reflux with a 10:1 mixture of methanol and conc. hydrochloric acid for 4.5 hours. Removal of the solvent and crystallization of the residue from 90% aqueous ethanol gave the hydrochloride of 2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol, mp >260°.
Anal. Calcd. for C 15 H 20 ClNO 2 : C, 63.94; H, 7.15; N, 4.97. Found: C, 64.04; H, 7.17; N, 5.13.
EXAMPLE 14
3-Ethyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI, R 1 =C 2 H 5 ; R 2 =OH)
(a) Acetyl chloride (1 ml) was added to a stirred mixture of 1.00 g of 9-methoxy-2,3,4,4aα5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (Example 12), 8 ml of methylene chloride, and 10 ml of 15% aqueous sodium hydroxide solution, keeping the temperature below 15°. The layers were separated after stirring at room temperature for 3 hours, and the aqueous phase was extracted once with methylene chloride. The combined methylene chloride layers were dried and concentrated to give 1.17 g of crude 3-acetyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline. This was reduced with 0.4 g of lithium aluminum hydride in tetrahydrofuran at reflux for 6 hours and the product was short path distilled at 0.5 micron pressure (bath temperature 170°) to give 0.97 g of 3-ethyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e] isoquinoline (VI, R 1 =C 2 H 5 ; R 2 =OMe). Nmr spectrum (220 MHz, in CDCl 3 ): τ2.8-3.0(m,1); 3.2-3.3(m,2); 5.5(t,J≃5 Hz,1); 6.1(s,3); 7.0-8.6(m,15) and 8.8(t,J=7 Hz,3).
(b) A mixture of 0.84 g of VI(R=C 2 H 5 ; R 2 =OMe; above), 1 g of potassium t-butoxide, 1.3 ml of n-propyl mercaptan and 20 ml of dimethylformamide was stirred under nitrogen in an oil bath at 130° for 5 hours. The cooled mixture was treated with 1 ml of acetic acid, and the volatiles were removed under vacuum. The residue was treated with dilute hydrochloric acid and ether, and the aqueous acidic phase was made basic with 10% aqueous sodium carbonate solution. Extraction with methylene chloride furnished, after drying and removal of the solvent, 0.82 g of crude product which on crystallization from 90% aqueous ethanol gave 0.49 g of 3-ethyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI, R 1 =C 2 H 5 ; R 2 =OH), mp 189°-190°.
Anal. Calcd. for C 17 H 23 NO 2 : C, 74.69; H, 8.48; N, 5.12. Found: C, 74.68; H, 8.44; N, 5.03.
EXAMPLE 15
3-Allyl-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI,R 1 =CH 2 CH═CH 2 ; R 2 =OMe)
A mixture of 1.31 g of VI(R 1 =H; R 2 =OMe), 3 g of sodium bicarbonate, 8 ml of dimethylformamide and 2 ml of allyl bromide was stirred at room temperature overnight. Methanol was added, the mixture was filtered, and the solid was washed twice with hot methanol. Removal of the solvents from the filtrate gave 2.62 g of crude quaternary bromide. This salt was heated with 15 ml of methanol and 6.7 g of trimethylamine in a sealed tube to 100° for 8 hours. The solvent was removed and the residue was stirred with methylene chloride and 15% aqueous sodium hydroxide solution. Removal of the solvent from the dried methylene chloride solution and short-path distillation (140°-165° bath temperature, 0.05 micron pressure) gave 1.09 g of VI(R 1 =CH 2 CH═CH 2 ; R 2 =OMe). Nmr spectrum (220 MHz in CDCl 3 ): τ2.7-2.9(m,1); 3.1-3.2 (m,2); 3.7-4.3 (m,1); 4.5-4.9(m,2); 5.5(t,J≃5.5 Hz,1); 6.1(s,3); 6.8(d, split further, 2), and 7.0-9.9(m,13).
EXAMPLE 16
3-Allyl-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI; R 1 =CH 2 CH═CH 2 ; R 2 =OH)
Treatment of the quaternary salt obtained in Example 15 with potassium t-butoxide and n-propyl mercaptan in dimethyl formamide as described in Example 5 gave VI(R 1 =CH 2 CH═CH 2 ; R 2 =H), mp 160°-161°.
Anal. Calcd. for C 18 H 23 NO 2 : C, 75.76; H, 8.12; N, 4.91. Found: C, 75.73; H, 8.00; N, 4.69.
EXAMPLE 17
3-(3'-Methyl-2'-butenyl)-9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =CH 2 CH═CMe 2 ; R 2 =OMe)
Following the procedure of Example 15, but using 1-bromo-3-methyl-2-butene in place of allyl bromide gave VI(R 1 =CH 2 CH═CMe 2 ; R 2 =OMe) Nmr spectrum (220 MHz in CDCl 3 ): 2.8-3.0(m,1); 3.2-3.3(m,2); 4.7(t,J=7 Hz, split further, (1); 5.5(t,J≃5.5 Hz,1); 6.1(s,3); 7.0(d, split further, (2) and 7.1-9.1(m,19).
EXAMPLE 18
3-(3'-methyl-2'-butenyl)-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI; R 1 =CH 2 CH═CME 2 ; R 2 =OH)
Following the procedure of Example 16, but using the quaternary ammonium salt obtained in Example 17, there was obtained VI(R 1 =CH 2 CH═CMe 2 ; R 2 =H), mp 143°-144°.
Anal. Calcd. for C 20 H 27 NO 2 : C, 76.64; H, 8.68; N, 4.47. Found: C, 76.62; H, 8.48; N, 4.28.
EXAMPLE 19
3-(3'-Methylbutyl)-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (VI; R 1 =CH 2 CH 2 CHMe 2 ; R 2 =OH)
Catalytic hydrogenation (tetrahydrofuran, pre-reduced platinum oxide) of VI(R 1 =CH 2 CH═CMe 2 ; R 2 =OH; Example 18) gave VI(R 1 =CH 2 CH 2 CHMe 2 ; R 2 =OH), mp 188°-189°.
Anal. Calcd. for C 20 H 29 NO 2 : C, 76.15; H, 9.27; N, 4.44. Found: C, 76.08; H, 8.97; N, 4.35.
EXAMPLE 20
9-Methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline-3-acetonitrile (VI, R 1 =CH 2 CN; R 2 =OMe)
A mixture of 1.32 g of VI(R 1 =H; R 2 =OMe), 8 ml of dimethylformamide, 2.4 g of potassium carbonate and 2 ml of chloroacetonitrile was stirred at room temperature for 3.5 hours. The solvent was removed and the residue was stirred with toluene. Removal of the solvent from the filtered solution and crystallization from ethyl acetate gave 1.03 g of VI(R 1 =CH 2 CN; R 2 =OMe), mp 135°-136°.
Anal. Calcd. for C 18 H 22 N 2 O 2 : C, 72.46; H, 7.43; N, 9.39. Found: C, 72.26; H, 7.35; N, 9.20.
The following compounds were prepared from 9-methoxy-2,3,4,4aα,5,6,7,7aα-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI; R 1 =H; R 2 =OMe) according to the procedures given in Example 14.
__________________________________________________________________________ ##STR62##Ex.No. R.sub.1 R.sub.2 Mp Analytical Data__________________________________________________________________________21 (CH.sub.2).sub.2 Me OMe oil Nmr spectrum (220MHz in CDCl.sub.3): τ2.7-2.9(m,l); 3.0-3.2(m,2); 5.5(t, J ≅ 5.5Hz,l); 6.1(s,3); 6.9-8.9(m,17); 9.0(t, J = 7Hz,3).22 (CH.sub.2).sub.2 Me OH 146°-148° Anal. Calcd. for C.sub.18 H.sub.25 NO.sub.2 : C, 75.22; H, 8.77; N, 4.87. Found: C, 75.29; H, 8.67; N, 4.8023 (CH.sub.2).sub.3 Me OMe oil Nmr spectrum (220 MHz in CDCL.sub.3): τ2.8-3.0(m,l); 3.1-3.3(m,2); 5.5(t, J ≅ 5.5Hz,l); 6.1(s,3); 7.1-8.9(m,19) and 9.0(t, J = 7Hz,3).24 (CH.sub.2).sub.3 Me OH 145°-146° Anal. Calcd. for C.sub.19 H.sub.27 NO.sub.2 : C, 75.71; H, 9.03; N, 4.65. Found: C, 76.01; H, 8.93; N, 4.61.25 (CH.sub.2).sub.4 Me OMe oil Nmr spectrum (220 MHz, in CDCl.sub.3) τ2.8-3.0(m,l); 3.1-3.3(m,2); 5.5(t, J ≅ 5.5Hz,1); 6.1(s,3); 7.0-8.9(m,21) and 9.0 (t,J =0 7Hz,3)26 (CH.sub.2).sub.4 Me OH 220°(dec,; Mass spectrum(free base): m/e HCl salt) calcd. 315.2197; Found 315.218927 (CH.sub.2).sub.5 Me OMe oil NMr spectrum (220MHz in CDCl.sub.3) τ2.7-2.9(m,l); 3.1-3.3(m,2); 5.5(t, J ≅ 5.5Hz,1); 6.1(s,3); 7.0-8.8(m,23) and 9.0(t, split further,3).28 (CH.sub.2).sub.5 Me OH 218° (HCl salt) Anal. (HCl salt) Calcd. for C.sub.21 H.sub.32 ClNO.sub.2 : C, 68.93; H, 8.81; N, 3.83. Found: C, 69.06; H, 8.49; N, 3.85.29 (CH.sub.2).sub.7 Me OMe oil Nmr spectrum (220 MHz in CDCl.sub.3) τ2.8-3.0(m,1); 3.2-3.3(m,2); 5.5(t, J ≅ 5.5Hz,1); 6.1(s,3); 7.0-8.8(m,27) and 9.1(t, split further,3).30 (CH.sub.2).sub.7 Me OH 188°-190° Mass spectrum(free base); (hydro- m/e calcd. 357.2666; chloride) Found: 357.2653.31 CH.sub.2 CHMe.sub.2 OMe oil Nmr spectrum (220MHz in CDCl.sub.3) τ2.8-3.0(m,1); 3.2-3.3(m,2); 5.5(t, J ≅ 5.5Hz,1); 6.1(s,3); 7.1-8.8(m,16) and 9.1 d,J = 7Hz,6)32 CH.sub.2 CHMe.sub.2 OH 170°-171° Anal. Calcd. for C.sub.19 H.sub.27 NO.sub.2: C, 75.71; H, 9.03; N, 4.65. Found: C, 75.68; H, 8.90; N, 4.62.33 ##STR63## OMe oil Nmr spectrum (220 MHz, in CDCl.sub.3) τ2.8-3.0(m,l); 3.2-3.3(m,2); 5.6(t, J ≅ 5.5Hz,1); 6.1(s,3); 7.0-9.5(m,26).34 ##STR64## OH 141°-142° Anal. Calcd. for C.sub.22 H.sub.31 NO.sub.2 : C, 77.38; H, 9.15; N, 4.10. Found: C, 77.12; H, 8.87; N, 3.95.35 ##STR65## OMe >260° (HCl salt) Nmr spectrum (free base, 220 MHz in CDCl.sub.3): τ2.8- 3.0(m,5); 3.2-3.3(m,2); 5.6(t,J ≅ 5Hz,1); 6.2(s, 3); 7.0-7.5(m,8); 7.7 s,3) and 7.8-9.0(m,9).36 ##STR66## OH 136°-140° Mass spectrum calcd. m/e 363.2197: found m/e 363.2208.37 ##STR67## OMe oil Nmr spectrum(220 MHz, in CDCl.sub.3): τ 2.6(m,1); 3.0 (d/d,J = 6/3Hz,1); 3.2-3.2 (m,2); 3.7(m,1); 3.8(d, J = 3Hz,1); 5.5(t,J ≅ 5Hz,1); 6.1(s,3); 6.3(s,2), and 7.1-9.0(13).38 ##STR68## OH 135°-137° Anal. Calcd. for C.sub.20 H.sub.23 NO.sub.3 : C, 73.82; H, 7.23; N, 4.30. Found: C, 73.75; H, 7.18; N, 4.33.39 ##STR69## OMe oil Nmr spectrum (220 Mhz in CDCl.sub.3): τ2.8-3.0(m,1); 3.2-3.3(m,2); 5.5(t,J ≅ 5.5 Hz,1); 5.8-6.3(m + s,6); 7.0-7.5(m,6) and 7.9- 9.0(m,13).40 ##STR70## OH 138°-145° Anal. Calcd. for C.sub.20 H.sub.27 NO.sub.3 : C, 72.92; H, 8.26; N, 4.25. Found: C, 72.87; H, 8.14; N, 4.40.41 ##STR71## OMe oil Nmr spectrum (220 MHz in CDCl.sub.3): τ2.7-2.9(m,1); 3.0-3.2(m,3); 3.3-3.4(m,2); 5.6(t,J ≅ 5.5Hz,1); 6.2(2s, 5); 7.1-9.0(m,13).42 ##STR72## OH 126°-128° Mass spectrum: m/e calcd. 341.1448; Found: 341.1443.__________________________________________________________________________
Description of compounds of this invention by variation in substituents ##STR73##
(1) Variation of R 1
(a) R 1 =C 1-10 alkyl, --CH 2 R 6 (R 6 =C 3-6 cycloalkyl, tetrahydrofurylmethyl, tetrahydrofuryl), ##STR74## (R 7 =C 1-3 alkyl, --OCH 3 , --Cl, --Br, --F): by starting with the corresponding amines II which in turn are prepared from the amine II (R 1 =H) by acylation followed by reduction as examplified in Example 4b or directly from the tosylate of I and R 1 NH 2 as shown in Example 1b. Alternatively, these groups could be introduced into VI (R 1 =H; R 2 =H or alkoxy) by acylation followed by reduction or by direct alkylation.
Thus, substituting n-propylamine for methylamine in Example 2b there is obtained 7-methoxy-N-n-propyl-3-benzofuranethylamine, which by the procedures of Example 2c, 2d, and 3 is converted to 3-n-propyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (R 1 =n-propyl; R 2 =OH; R 3 , R 4 , R 5 =H).
Substituting p-methylphenylacetyl chloride for cyclopropanecarbonyl chloride in Example 4b there is obtained N-p-methylphenethyl-7-methoxy-3-benzofuranethylamine which by the procedures of Examples 2c, 2d and 3 is converted to 3-p-methylphenethyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol ##STR75##
Treating 9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (VI, R 1 =H; R 2 =OMe) with tetrahydrofuroyl chloride in the presence of a base such as aqueous sodium hydroxide solution gives 9-methoxy-3-tetrahydrofuroyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline, which on reduction with lithium aluminum hydride affords 9-methoxy-3-tetrahydrofurylmethyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR76## Similarly, 3-p-chlorophenethyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol is produced using p-chlorophenylacetyl chloride.
Treating 9-ethoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline with cyclohexylmethyl bromide in the presence of a base such as potassium carbonate in a solvent such as dimethylformamide gives 3-cyclohexylmethyl-9-ethoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR77##
(b) R 1 =H: by demethylation of the corresponding 3-methyl compound (R 1 =Me) by any standard method such as treatment with cyanogen bromide or phenyl chloroformate or by catalytic hydrogenolysis of the 3-benzyl derivative (R 1 =CH 2 Ph) prepared as described in (1a) above.
Thus, 9-methoxy-3-methyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (Example 2d) is heated to reflux with cyanogen bromide in methylene chloride and the crude product is then heated with potassium hydroxide in ethylene glycol to 170° to give 9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (R 1 =H; R 2 =OMe; R 3 , R 4 , R 5 =H).
3-Benzyl-9-ethoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline on stirring in acetic acid or ethanol solution, optionally in the presence of hydrochloric acid, with a catalyst such as palladium on charcoal under an atmosphere of hydrogen gives, after workup, 9-ethoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (R 1 =H; R 2 =OEt; R 3 , R 4 , R 5 =H). ##STR78## C.tbd.CH, 2-thienyl, 2-furyl. These groups are introduced after the intramolecular Diels-Alder reaction since they interfere with that reaction. The secondary amines VI (R 1 =H) are alkylated with ##STR79## (X=Cl, Br or I) or X--CH 2 C.tbd.CH; any quaternary salt formed can be converted to tertiary amine by heating with trimethylamine in methanol. The 2-thienyl or 2-furyl is introduced by acylation of the secondary amines VI (R 1 =H) with ##STR80## (Y=O or S) followed by reduction with LiAlH 4 .
Thus, 9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline, when treated with allyl bromide in the presence of a base such as potassium carbonate, gives 3-allyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (R 1 =CH 2 CH═CH 2 ; R 2 =MeO; R 3 , R 4 , R 5 =H). Also, thienyl or furyl carbonyl chlorides followed by reduction with lithium aluminum hydride give 3-(2-thienylmethyl or 2-furylmethyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR81##
(d) R 1 =(CH 2 ) n CN where n=1, 2 or 3 are prepared by alkylation of VI (R 1 =H) with X(CH 2 ) n CN where X=Cl, Br or I to give e.g., 3-β-cyanoethyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,3]furo[3,2-e]isoquinoline (VI; R 1 =CH 2 CH 2 CN; R 2 =OMe).
(2) Variation of R 2
Introduction of R 2 =H, OH, and OMe is exemplified in the examples; by starting with the appropriate benzofuran, R 2 can be OEt (i.e. C 2 alkoxy). Alternatively, the phenols VI (R 2 =OH) may be alkylated, for instance with ethyl iodide and sodium hydride; C 2-12 acyloxy is introduced by acylating the phenols VI (R 2 =OH) by standard methods.
Thus, substituting methyl-3-ethoxysalicylate for methyl o-vanillate in Example 2a there is obtained 7-ethoxy-3-benzofuranethanol. Further treatment according to the procedure of Examples 2b, 2c, and 2d gives 9-ethoxy-3-methyl-2,3,4,4a,5,6,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline (R 1 =Me; R 2 =OEt; R 3 , R 4 , R 5 =H).
Treatment of 3-cyclopropylmethyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol (Example 5) with propionyl chloride in dimethylformamide in the presence of a base such as triethylamine or potassium carbonate gives the propionate ester of 3-cyclopropylmethyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-9-ol ##STR82##
(3) Variation of R 3 and R 4
Reaction of dienamides of type IV with singlet oxygen followed by treatment with base gives 4a-hydroxy-2,7a-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4,7-(3,4aH)-dione (IX) which on treatment with ##STR83## methanesulfonyl chloride and a base, followed by reduction with a complex hydride such as lithium aluminum tri-tert-butoxy hydride gives the 2,3,4,4a,7,7a-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7-ols X. Saturation of the double bond in X gives 2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7-ols (XI). The preferred compounds have the 7β-hydroxy group as in morphine. ##STR84## These can be alkylated or acylated to give compounds with R 3 =alkoxy or acyloxy; treatment with diethylamino sulfur trifluoride gives the derivatives where R 3 =F. Reaction of XI with p-toluenesulfonyl chloride in pyridine and treatment of the resulting tosylate with sodium azide in a polar solvent such as dimethyl sulfoxide gives the compounds where R 3 =N 3 . Oxidation of XI, for instance with Jones' reagent, gives 2,4,4a,5,6,7a-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7[3H]-ones (XII). Reaction of XII with methylene triphenylphosphorane followed by catalytic hydrogenation gives compounds where R 3 =Me. The difluoro derivative (R 3 , R 4 =F) is obtained by treating XII with diethylaminosulfur trifluoride.
Catalytic hydrogenation of IX followed by reduction with a complex hydride ##STR85## gives 2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4a,7-diols (XIII).
Catalytic hydrogenation of the dieneamides IV can be stopped after the less hindered 6,7-double bond only has been saturated, giving 2,6,7,7a-tetrahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[3H]-ones (XIV). These on treatment with a peracid, such as m-chloroperbenzoic acid, give 4a,5-epoxy- 2,4a,5,6,7,7a-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[3H ]-ones (XV) which on reduction with a metal hydride such as lithium aluminum hydride furnish the 2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4a-ols (XVI). ##STR86##
Thus, reaction of 3-cyclopropylmethyl-9-methoxy-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4-[4aH]-one (Example 4c) with singlet oxygen, generated for instance by reaction of hydrogen peroxide with sodium hypochlorite, followed by treatment with aqueous sodium hydroxide, gives 3-cyclopropylmethyl-4a-hydroxy-9-methoxy-2,7a-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4,7[3,4aH]-dione ##STR87## This, on treatment with methanesulfonyl chloride in pyridine, followed by reduction with lithium aluminum tri-tert-butoxy hydride gives 3-cyclopropylmethyl-9-methoxy-2,3,4,4a,7,7a-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7-ol ##STR88## Catalytic hydrogenation of this compound gives 3-cyclopropylmethyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7-ol ##STR89##
Reaction of XI ##STR90## with sodium hydride and methyl iodide gives 3-cyclopropylmethyl-7,9-dimethoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR91## Acylation of XI ##STR92## with acetic anhydride and pyridine gives the acetate of 3-cyclopropylmethyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7-ol ##STR93##
Reaction of XI ##STR94## with diethylaminosulfur trifluoride gives 3-cyclopropylmethyl-7-fluoro-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR95##
Reaction of XI ##STR96## with p-toluenesulfonyl chloride in pyridine, followed by treatment of the tosylate with sodium azide in dimethylsulfoxide gives 3-cyclopropylmethyl-7-azido-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR97##
Oxidation of XI ##STR98## with chromium trioxide gives 3-cyclopropylmethyl-9-methoxy-2,4,4a,5,6,7-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-7[3H]-one ##STR99## Reaction of this compound with methylenetriphenylphosphorane followed by catalytic hydrogenation of the resulting 7-methylene derivative gives 3-cyclopropylmethyl-9-methoxy-7-methyl-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR100##
Reaction of XII ##STR101## with diethylaminosulfur trifluoride gives 3-cyclopropylmethyl-7,7-difluoro-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline ##STR102##
Catalytic hydrogenation of IX ##STR103## followed by reduction with lithium aluminum hydride gives 9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4a,7-diol ##STR104##
Catalytic hydrogenation of 3-cyclopropylmethyl 9-methoxy-2,3-dihydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[4H]-one (Example 4c) is carried out as in Example 4d but the reaction is stopped after one mole equivalent of hydrogen has been taken up, giving 3-cyclopropylmethyl-9-methoxy-2,6,7,7a-tetrahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[3H]-one. This, on treatment with m-chloroperbenzoic acid gives 3-cyclopropylmethyl-4a,5-epoxy-9-methoxy-2,4a,5,6,7,7a-hexahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4[3H]-one which is reduced with lithium aluminum hydride to 3-cyclopropylmethyl-9-methoxy-2,3,4,4a,5,6,7,7a-octahydro-1H-benzo[4,5]furo[3,2-e]isoquinolin-4a-ol.
Pharmaceutically suitable acid addition salts of the compounds of this invention promote water solubility and include those made with physiologically acceptable acids that are known in the art; such salts include hydrochloride, sulfate, nitrate, phosphate, citrate, tartrate, maleate and the like.
UTILITY
The compounds of this invention can be administered orally at doses of about 0.01-100 mg/kg or preferably 0.05-25 mg/kg or more preferably 0.10-10 mg/kg. The compounds also can be given parenterally. The useful daily human oral dose is expected to be in the range of 10-200 mg. A typical dosage form could be capsules or a compressed tablet containing 2.5 to 10 mg active ingredient administered 1-4 times daily.
Analgesic Testing Procedures
A standard procedure for detecting and comparing the analgesic activity of compounds in this series for which there is good correlation with human efficacy is the standard phenylquinone writhing test modified from Siegmund, et al., Proc. Soc. Exp. Biol. Med., 95, 729 (1957). A test compound suspended in 1% methocel® was given orally to fasted (17-21 hours) female white mice, 5-20 animals per double blind test. Aqueous (0.01% phenyl-p-benzoquinone) phenylquinone was injected intraperitoneally at 24 minutes later using 0.20 ml per mouse. Commencing at 30 minutes after the oral administration of the test compound, the mice were observed for 10 minutes for a characteristic stretching or writhing syndrome which is indicative of pain induced by phenylquinone. The effective analgesic dose for 50% of the mice (ED 50 ) was calculated by the moving average method of Thompson, W. R., Bact. Rev., 11, 115-145 (1947).
Narcotic analgesics produce in mice an erection and arching of the tail (90° or more) which is referable to spinal cord stimulation. This Straub tail reaction is not produced by other analgesics, including the narcotic antagonists.
The method used was modified from Shemano, I., and Wendel, H., Tox. Appl. Pharm., 6, 334-9 (1964). CF 1 S female mice (18-21 g), 10-20 mice per dose, were intubated with log scaled doses of analgesic in 1% aqueous methylcellulose. A positive Straub tail response was recorded if a tail was erected 90° or more for 5 seconds at any time within 24 minutes after dosing. A quantal Straub tail ED 50 was calculated by the moving average method [Thompson, W. R., Bact. Rev., 11, 115-145 (1947)].
TABLE 1__________________________________________________________________________ ##STR105## EFFECT ED50 Oral Oral Intraperitoneal(i.p.) Anti- Straub- or subcutaneous(s.c.)Ex. R.sup.1 R.sup.2 PQW Tail Anti-Straub Tail__________________________________________________________________________ 1 Me H 14. >81. -- 2 Me OMe 9.8 >135. 10.1 (i.p.) 3 Me OH 3.5 >135. 0.27 (s.c.) 3 Me OH 2.1 >135 0.14 (s.c.) (-)isomer 3 Me OH 61 >135 3.3 (s.c.) (+)isomer 4##STR106## OMe 19.7 >135. 0.31 (i.p.) 5##STR107## OH 0.75 >81. 0.006 (s.c.) 7##STR108## OH 81. >81. 0.64 (i.p.)Mor-phine 3.0 48. --Pent-azo-cine 56. >135. 4.0 (s.c.) 9##STR109## ##STR110## 0.75 >135. 0.005 (s.c.)10##STR111## OMe 48. >81. 48. (s.c.)11##STR112## OH 29. >81. 1.2 (s.c.)12 H OMe 47. >81. --13 H OH 15. >135. >27. (s.c.)14a C.sub.2 H.sub.5 OMe 63. >135. 0.71 (s.c.)14b C.sub.2 H.sub.5 OH 135. >135. 0.028 (s.c.)15 CH.sub.2 CHCH.sub.2 OMe 62. >135. 0.30 (s.c.)16 CH.sub.2 CHCH.sub.2 OH 81. >81. 0.03 (s.c.)17 CH.sub.2 CHCMe.sub.2 OMe 18.7 >135. 7.8 (s.c.)18 CH.sub.2 CHCMe.sub.2 OH 10.8 32. >27. (s.c.)19 CH.sub.2 CH.sub.2 CHMe.sub.2 OH 33. >135. 0.64 (s.c.)20 CH.sub.2 CN OMe 26 >135 >27. (s.c.)21 C.sub.3 H.sub.7 OMe 78. >135. 0.08 (s.c.)22 C.sub.3 H.sub.7 OH 112. >135. 0.008 (s.c.)23 C.sub.4 H.sub.9 OMe 33. >135. 0.82 (s.c.)24 C.sub.4 H.sub.9 OH 23. >135. 0.032 (s.c.)25 C.sub.5 H.sub.11 OMe 6.2 57. >27. (s.c.)26 C.sub.5 H.sub.11 OH 5.3 37. >27. (s.c.)27 C.sub.6 H.sub.13 OMe 7. 25. >27. (s.c.)28 C.sub.6 H.sub.13 OH 2.9 26. --29 C.sub.8 H.sub.17 OMe 7.2 -- >27. (s.c.)30 C.sub.8 H.sub.17 OH 4.2 54. --31 CH.sub.2 CHMe.sub.2 OMe 94. >135. 0.24 (s.c.)32 CH.sub.2 CHMe.sub.2 OH 63. >135. 0.03 (s.c.)33##STR113## OMe 135. >135. --34##STR114## OH 23. >135. >27. (s.c.)35##STR115## OMe 1.7 52. 56. (s.c.)36##STR116## OH 0.67 39. >81. (s.c.)37##STR117## OMe 84. >135. 12. (s.c.)38##STR118## OH 108. >135. 7.2 (s.c.)39##STR119## OCH.sub.3 16.7 -- 4.7 (s.c.)40##STR120## OH 11.8 -- 0.19 (s.c.)41##STR121## OMe 48. >135. >27. (s.c.)42##STR122## OH 108. >135. --__________________________________________________________________________
Known narcotic antagonists such as naloxone and nalorphine prevent the induction of Straub tail in mice by a highly addicting agonist such as morphine [H. Blumberg, H. B. Dayton and P. S. Wolf, The Pharmacologist, 10, 189 (1968)]. This property is the basis of a mouse test for narcotic antagonists.
Female CF 1 S mice (fasted 17-21 hrs.), 5 per dose, were injected orally or subcutaneously with test drug at 0.67, 2, 6, 18, 54 and 162 mg/kg or other appropriate doses in 0.20 ml 1% Methocel® per mouse. Five minutes later, 30 mg/kg of morphine sulfate in 0.20 ml 1% Methocel® per mouse was given intraperitoneally starting ten minutes later, the mice were observed continuously for 5 minutes for evidence of Straub tail. Prevention of a 90° Straub tail during this observation period was taken as indication of narcotic antagonist ability.
The data are in Table 1. Most of the compounds were analgetic in the mouse antiphenylquinone test system and only a few caused Straub tail. Most also were antagonists in the mouse anti-Straub tail test.
The foregoing analgesia data show that most of the compounds of the invention are more potent than pentazocine and, indeed, compound of Example 5 is shown to have several times greater potency than morphine, which is the standard to which strong analgesics are compared. On the other hand, the very high Straub tail ED 50 's indicate that most of the compounds of the invention have very low likelihood of being addictive. In addition, the results of the Straub tail antagonism test show that most of the compounds of the invention have very high narcotic antagonism capability. Thus, the compounds of the invention are characterized by rapid onset of action, high oral potency and the ability to alleviate deepseated pain. Furthermore, abuse liability for most of the compounds should be extremely low or non-existent. In addition, some compounds of the invention which are pure narcotic antagonists, e.g., Example 10 will be useful for treatment of narcotic overdose.
DOSAGE FORMULATIONS
Analgesic and narcotic antagonistic agents of this invention can be administered to treat pain by any means that produces contact of the active agent with the agent's site of action in the body of a mammal. The compounds of the invention also can be used to alleviate the effect of narcotic agents. They can be administered by any conventional means available for use in conjunction with pharmaceuticals; either as individual therapeutic agents or in a combination of therapeutic agents. They can be administered alone, but are generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.
The dosage administered will, of course, vary depending upon known factors such as the pharmacodynamic characteristics of the particular agent, and its mode and route of administration; age, health, and weight of the recipient; nature and extent of symptoms, kind of concurrent treatment, frequenct of treatment, and the effect desired. Usually a daily dosage of active ingredient can be about 0.01 to 100 milligrams per kilogram of body weight. Ordinarily 0.05 to 25 and preferably 0.10 to 10 milligrams per kilogram per day given in divided doses 1 to 4 times a day or in sustained release form is effective to obtain desired results.
Dosage forms (compositions) suitable for internal administration contain from about 0.1 milligram to about 500 milligrams of active ingredient per unit. In these pharmaceutical compositions the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition.
The active ingredient can be administered orally in solid dosage forms, such as capsules, tablets, and powders, or in liquid dosage forms, such as elixirs, syrups, and suspensions; it can also be administered parenterally, in sterile liquid dosage forms.
Gelatin capsules contain the active ingredient and powdered carriers, such as lactose, sucrose, mannitol, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of hours. Compressed tablets can be sugar coated or film-coated to mask any unpleasant taste and protect the tablet from the atmosphere, or enteric-coated for selective disintegration in the gastrointestinal tract.
Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance.
In general, water, a suitable oil, saline, aqueous dextrose (glucose), and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration contain preferably a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid either alone or combined are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl-paraben, and chlorobutanol.
Suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences, E. W. Martin, a standard reference text in this field.
Useful pharmaceutical dosage-forms for administration of the compounds of this invention can be illustrated as follows:
Capsules
A large number of unit capsules are prepared by filling standard two-piece hard gelatin capsules each with 10 milligrams of powdered active ingredient, 215 milligrams of lactose, 24 milligrams of talc, and 6 milligrams magnesium stearate.
Capsules
A mixture of active ingredient in soybean oil is prepared and injected by means of a positive displacement pump into gelatin to form soft gelatin capsules containing 10 milligrams of the active ingredient. The capsules are washed in petroleum ether and dried.
Tablets
A large number of tablets are prepared by conventional procedures so that the dosage unit is 10 milligrams of active ingredient, 6 milligrams of magnesium stearate, 70 milligrams of microcrystalline cellulose, 11 milligrams of cornstarch and 315 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption.
Injectable
A parenteral composition suitable for administration by injection is prepared by stirring 2.0% by weight of active ingredient in 10% by volume propylene glycol and water. The solution is sterilized by filtration.
Suspension
An aqueous suspension is prepared for oral administration so that each 5 milliliters contain 2 milligrams of finely divided active ingredient, 200 milligrams of sodium carboxymethyl cellulose, 5 milligrams of sodium benzoate, 1.0 gram of sorbitol solution, U.S.P., and 0.025 milliliter of vanillin.
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Octahydro-1H-benzo[4,5]furo[3,2-e]isoquinoline compounds and processes for their manufacture are provided. The compounds correspond to the formula ##STR1## These compounds exhibit both analgesic and narcotic antagonistic properties, as well as low abuse liability.
Novel intermediate compounds are also provided which have the formula ##STR2##
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent application serial No. 60/293,654, filed May 25, 2001.
FIELD OF THE INVENTION
[0002] This invention relates to a multi-port valve that is used for selection of fluid streams and/or injection of fluids in processes such as liquid chromatography and mass spectrometry. In particular, the invention relates to an injection/selection valve that utilizes a clamping assembly to connect tubes or capillaries to a common port in the valve with minimal dead volume.
BACKGROUND OF THE INVENTION
[0003] Multiport selector/injector valves are well known and have been used in a variety of industrial processes, such as liquid chromatography and mass spectrometry. For example, selection valves are commonly used in liquid chromatography and other analytical methods to direct fluid flow along alternate paths. Such valves are also used to terminate fluid withdrawal from one source and select another source of fluid, for example, such as when a variety of streams in an industrial process is selectively sampled for analysis.
[0004] Injector/selector valves are often used in high pressure liquid chromatography (HPLC) or gas chromatography (GC). U.S. Pat. No. 4,242,909 (Gundelfinger '909), which is hereby fully incorporated by reference, describes a sample injection apparatus for withdrawing liquid samples from vials and injecting them into a chromatographic column or other analyzing device. The apparatus is said to minimize wastage, cross contamination, and dilution of the samples, and to be capable of automation with a minimum of complexity. Injector/selector valves are particularly useful in chromatographic applications since a substantial amount of time and effort is required to set up a particular HPLC or GC system, which may often utilize multiple columns and/or multiple detection systems. Multiport selection valves permit the operator of the chromatograph to redirect flows such that particular samples are selected for injection into a particular column, or alternatively, to direct the output from a particular column to one or more different detectors.
[0005] As mentioned above, multiport selection valves have been known for some time, including those which utilize a cylindrical rotor and stator combination. In some of these valves, the stator holds the fluid tubes in fixed relation to each other and presents the tube ends to a rotor face which may contain a grooved surface. By varying the angle of the rotor, the tubes are selectively brought into fluid communication. One type of injector/selector valve using a rotor/stator combination is the Type 50 rotary valve from Rheodyne, Incorporated. The Type 50 valves are said to operate by rotation of a flat rotor against a flat stator (see “Operating Instructions for Type 50 Teflon Rotary Valves,” Rheodyne, Incorporated, printed in U.S.A. April 1994). Another rotor/stator selector valve is shown in U.S. Pat. No. 5,193,581 (Shiroto, et al.), which is hereby fully incorporated by reference. The valve is said to comprise, among other things, a stator plate having a plurality of outlet holes extending through the stator plate and arranged in a circle concentric with a valve casing, and a rotor having a U-shaped passage formed in the rotor. The rotor is said to be rotated through a desired angle so that an inlet hole can be in fluid communication with selected ones of the outlet holes through the U-shaped passage of the rotor.
[0006] U.S. Pat. No. 5,419,419 (Macpherson) describes a rotary selector valve that is used in connection with an automatic transmission in an automobile. A motor is said to index a shear plate of the selector valve to predetermined positions for shifting the transmission. A series of working lines as shown in FIG. 6 are maintained in a closed spatial relationship with the casing.
[0007] U.S. Pat. No. 3,494,175 (Cusick, et al.) discloses a valve having a plurality of capillaries which are held in spaced relationship within a manifold plate member. U.S. Pat. No. 3,752,167 (Makabe) discloses a fluid switching device including a plurality of capillaries that are held within threaded holes by couplings. A rotary member allows fluid communication between the tubes. U.S. Pat. No. 3,868,970 (Ayers, et al.) discloses a multipositional selector valve said to be adapted with a means for attaching a plurality of chromatographic columns to the valve, such that the flow can be directed into any of the columns. U.S. Pat. No. 4,705,627 (Miwa, et al.) discloses a rotary valve said to consist of two stator discs and a rotor disposed between the two stator discs. Each time the rotor is turned intermittently it is said, different passages are formed through which the fluid in the valve runs. U.S. Pat. No. 4,722,830 (Urie, et al.) discloses multiport valves. The multiport valves are said to be used in extracting fluid samples from sample loops connected with various process streams.
[0008] In many applications using selector/injector valves to direct fluid flows, and in particular in liquid and gas chromatography, the volume of fluids is small. This is particularly true when liquid or gas chromatography is being used as an analytical method as opposed to a preparative method. Such methods often use capillary columns and are generally referred to as capillary chromatography. In capillary chromatography, both gas phase and liquid phase, it is often desired to minimize the internal volume of the selector or injector valve. One reason for this is that a valve having a large volume will contain a relatively large volume of liquid, and when a sample is injected into the valve the sample will be diluted, decreasing the resolution and sensitivity of the analytical method.
[0009] In the design of selector or injector valves with minimal internal volume, the prime design consideration is to bring all of the fluid passages into the closest possible proximity to each other. To do this with conventional capillary connectors is very difficult, since the nuts of the connectors are relatively large and require a fair amount of space. Thus, the valve itself has to be relatively large in order to accommodate the connections.
[0010] One solution to the large connectors has been to drill the injector ports on an angle. By angling the injector ports, the ends of the channels can all emerge in close proximity to a common point, while the opposite ends of the channels are sufficiently spaced apart to accommodate the larger connectors. An example of this approach is shown in U.S. Pat. No. 5,419,208 (Schick), which is hereby fully incorporated by reference. However, this approach has certain drawbacks. First, angled holes are difficult to produce and expensive to machine. Further, the angled passage from the capillary connector to the center of the valve stator is longer than it would be if the capillary could be connected directly on the face of the valve in close proximity to other capillaries. This additional length creates additional dead volume, which is undesirable as noted above. A further disadvantage of this approach is that the emerging hole near the center of the valve stator has an elliptical shape, which is not desirable.
[0011] Another type of capillary connection is shown in U.S. Pat. No. 4,792,396 (Gundelfinger '396), which is hereby fully incorporated by reference. Gundelfinger '396 describes a frame used as part of an injector said to be useful in loading a sample at high pressure into a chromatographic column. The frame is said to comprise ferrules for sealing tubes, and it is said that a tube coupling hole in the frame can couple to a standard {fraction (1/16)}″ tube, but also can couple to a much smaller diameter tube useful for minimizing dispersion when small samples or small chromatographic columns are used. The use of ferrules to make capillary or tubing connections to chromatography apparatus is also shown in, for example, U.S. Pat. Nos. 5,674,388 (Anahara), 5,744,100 (Krstanovic), 5,472,598 (Schick), 5,482,628 (Schick), and 5,366,620 (Schick).
[0012] Still another approach involves the use of “ferrule clusters,” as described and explained in my copending U.S. patent application Ser. No. 09/343,131, titled “Selection Valve with Ferrule Cluster,” which is hereby fully incorporated by reference. The ferrule clusters minimize dead volume, but require the connection (or disconnection, as the case may be) of two or more capillaries to (or from) the valve at a time.
[0013] It would be desirable to have a selector/injector valve that can be made with the smallest possible valve volume. There is also a need for an injector/selector valve which brings capillary or tube ends into the closest possible proximity to each other and to the valve stator so that valve dead volume is minimized. There is also a need for a capillary connector system that can be used to connect capillaries in the closest possible proximity. Moreover, there is a need for apparatus and methods which allow an operator greater flexibility in selectively connecting and/or disconnecting capillaries to a valve while still meeting the other objectives.
SUMMARY OF THE INVENTION
[0014] The invention relates to a multi-port injection/selection valve that utilizes a clamp and ferrule assembly configuration to connect tubes or capillaries to a common port, or to each other, in the valve. The clamp and ferrule assemblies connect the tubes or capillaries to the body of the valve assembly. The use of the individual clamp and ferrule assemblies, as opposed to conventional connectors, permits the capillary ends to be positioned in extremely close proximity to the valve rotor and to each other, thus minimizing the space between two capillaries when they are in brought into fluid communication with each other (often referred to as the “dead volume” in the connection). The clamp and ferrule assemblies of the present invention also allow an operator to connect, or disconnect, one or more capillaries without connecting, or disconnecting the other capillary connections to the valve.
[0015] In one embodiment the invention is a valve, comprising: a) a plurality of clamp and ferrule assemblies, each having a ferrule and a clamp for removably attaching a capillary tube to the valve; b) a stator in contact with at least one of said ferrules, said stator having a stator front side and a stator flat surface opposite said front side, said stator front side having a plurality of impressions into which some or all of said ferrules are received, each of said impressions opening to a terminal cylindrical bore (tube pocket), each of said impressions also having a stator through-hole opening onto said stator flat surface; c) a plurality of capillary tubes, each of said capillary tubes extending through at least one of said ferrules and into a stator impression up to the terminus of said cylindrical bore; and d) a rotor comprising a stator-contact surface and at least one fluid communication channel, said stator-contact surface abutting said stator flat surface and being rotatable about an axis to establish fluid communication between selected pairs of capillaries through said fluid communication channel.
[0016] In yet other embodiments of the invention, the rotor has grooves for fluid flow that are etched into a glass, quartz, or other surface via photolithographic or other similar etching techniques. In still other embodiments of the invention, the invention is a capillary chromatographic system comprising the valve of the invention. In still other embodiments the invention is a method for carrying out a chromatographic or spectrometric analysis and methods for connecting and disconnecting capillary tubes to a chromatographic or mass spectrometry system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a sectional view showing a valve according to one embodiment of the invention.
[0018] [0018]FIG. 2 shows a front view of the valve of the present invention.
[0019] [0019]FIG. 3A shows a frontal view of a clamp in accordance with the present invention.
[0020] [0020]FIG. 3B shows a sectional view of the clamp shown in FIG. 3A.
[0021] [0021]FIG. 3C shows a detailed, fragmentary sectional view of the clamp shown in FIG. 3A.
[0022] [0022]FIG. 4A shows a frontal view of a 10-port stator of a valve in accordance with the present invention.
[0023] [0023]FIG. 4B shows a sectional view of the stator shown in FIG. 4A.
[0024] [0024]FIG. 4B shows a sectional view of the stator shown in FIG. 4A.
[0025] [0025]FIG. 4C shows a detailed, fragmentary, sectional view of the stator shown in FIG. 4A.
[0026] [0026]FIG. 5A shows a frontal view of a 10-port rotor of a valve in accordance with the present invention.
[0027] [0027]FIG. 5B shows a sectional view of the rotor shown in FIG. 5A.
[0028] [0028]FIG. 5C shows a detailed, enlarged sectional view of a portion of the rotor shown in FIGS. 5A and 5B.
[0029] [0029]FIGS. 5D, 5E, and 5 F show a frontal view, sectional view, and rear view, respectively, of an alternative embodiment of a rotor of a valve in accordance with the invention.
[0030] [0030]FIG. 6A shows a frontal view of a 10-port stator plate in a valve in accordance with the present invention.
[0031] [0031]FIG. 6B shows a sectional view of the stator plate shown in FIG. 6A.
[0032] [0032]FIG. 7 shows a ferrule in accordance with the present invention.
[0033] [0033]FIG. 8A shows a frontal view of a ferrule support in a valve in accordance with the present invention.
[0034] [0034]FIG. 8B shows a sectional view of the ferrule support shown in FIG. 8A.
[0035] [0035]FIG. 9 is a sectional view of a valve of the present invention taken along line 9 - 9 .
[0036] [0036]FIGS. 10A, 10B and 10 C are, respectively, a frontal view, sectional view, and sectional view along line 10 A- 10 A, of an adjustment nut in a valve of the present invention.
[0037] [0037]FIGS. 11A, 11B, and 11 C are a frontal view, sectional view, and rear view, respectively, of the main body of a valve of the present invention.
[0038] [0038]FIGS. 12A, 12B, and 12 C are a frontal view, sectional view, and rear view, respectively, of the rotor mount of a valve of the present invention.
[0039] [0039]FIGS. 13A and 13 are a frontal view and a side view, respectively, of a drive shaft of a valve of the present invention.
[0040] [0040]FIGS. 14A and 14B are side and frontal views, respectively, of an alternative stator plate of a valve in accordance with the present invention.
DETAILED DESCRIPTION
[0041] As seen in FIG. 1, one embodiment of the invention comprises a valve 1 which has plurality of capillaries 15 attached with corresponding ferrules 10 A and 10 B. The ferrules 10 A and 10 B of the invention may be of the double-ended type, as shown in FIG. 1 and in FIG. 7. The double-ended type approximates two single-ended ferrules with their ends joined. Thus, the double-ended ferrules 10 A and 10 B each have tapered gripping portions on both of their respective ends. As shown in FIG. 1, each of the capillaries 15 extend through an opening in a corresponding clamp 5 , through a corresponding ferrule 10 , which itself extends through a corresponding opening in ferrule support 17 , and through stator 20 , such that one end of each of the capillaries 15 are in fluid communication with a front surface of rotor 26 . These components of valve 1 and their various features are described below in more detail. It will be understood by those of ordinary skill that the valve 1 allows for the connection of a plurality of capillaries 15 in a manner which minimizes the dead volume between the ends of the capillaries 15 , while at the same time allowing an operator to connect or disconnect one or more capillaries 15 to or from valve 10 without having to connect or disconnect all capillaries 15 at the same time.
[0042] Referring still to FIG. 1, it can be seen that valve 1 also includes a main body 110 , a mounting bracket 115 , a handle 42 , a set screw 125 (for attaching the handle 42 to the knob 120 ), and a knob 120 . The handle 42 , set screw 125 , and knob 120 are assembled and attached to one another so that, when an operator, turns handle 42 , that action results in corresponding rotation of the shaft 30 and rotor 26 . Those skilled in the art will understand and appreciate that handle 42 can be attached or secured to shaft 30 via other means or can be combined into a unitary item with shaft 30 . Those skilled in the art will also understand and appreciate that handle 42 is useful for manual operation of the valve 1 by an operator, but the selective rotation of shaft 30 can be automated with conventional means. Those skilled in the art will further understand and appreciate the use of the adjustment nut 105 and the spring 36 to bias shaft 30 against rotor 26 to ensure that the valve 1 operates without any leaking, even at high pressures. Still referring to FIG. 1, it can be seen that each of the cap screws 6 can be tightened by an operator to bias and press the corresponding ferrule 10 and capillary 15 against the facing or abutting surface of rotor 26 . This further ensures leak-free operation of the valve.
[0043] Referring now to FIG. 2, a “frontal” view of valve 1 is shown. As shown in FIG. 2, a plurality of clamps 5 are disposed on the front of valve 1 . Those skilled in the art will understand that there may be more or less than ten (10) clamps 5 . In FIG. 2, there are ten (10) of clamps 5 . Each of clamps 5 has an opening 5 a through which a capillary 15 may extend (not shown in FIG. 2). Also as shown in FIG. 2, there is a cap screw 6 , a portion of which extends through the corresponding clamp 5 . Those of ordinary skill will understand and appreciate that the openings 5 a of clamps 5 are located in close proximity to one another, thereby minimizing the dead volume of the fluid communication between capillaries 15 when attached to valve 1 of the present invention. With the ten (10) clamps 5 configuration shown in FIG. 2, for example, I have been able to arrange the ten (10) openings 5 a in a circle with a diameter of only 6 mm. As also shown in FIG. 2, the cap screws 6 (like the openings 5 a ) are arranged in a circle, but the diameter of the circle formed by cap screws 6 is greater than the circle arrangement of the openings 5 a . This arrangement makes it easier for an operator to tighten or loosen each of the individual cap screws when connecting or disconnecting a capillary 15 . While cap screws 6 are shown, those skilled in the art will understand that other screws, threaded bolts, and fastening means may be used.
[0044] Referring now to FIGS. 3A, 3B, and 3 C, a clamp 5 in accordance with the present invention is shown in greater detail. Referring first to FIG. 3A, a frontal, or overhead, view of a clamp 5 is provided. (For ease of reference, the same numbers are used in various drawings to indicate the same items or features which may be identified in other drawings.) As shown in FIG. 3A, clamp 5 has a main body 5 c and also a tapered end 5 d . While opening 5 a may vary in size depending on the capillary 15 to be received, the valve 1 shown and described as the preferred embodiment has openings 5 a which are 2 mm in diameter. The opening 5 a for a capillary 15 (not shown in FIG. 3A) is located in the tapered end 5 d of a clamp 5 . As also shown in FIG. 3A, the clamp 5 has an opening 5 b through which a portion of a cap screw 6 (not shown in FIG. 3A) may extend.
[0045] Referring now to FIG. 3B, a sectional view of a clamp 5 is provided. As shown in FIG. 3B, the main body 5 c of clamp contains a back surface 501 and also an abutting surface 505 . As also shown in FIG. 3B, the opening 5 b includes conical surfaces 510 and 515 at each side (for convenience, the sides may be considered the “top” and “bottom” sides, respectively, of the clamp 5 ) the opening 5 b . As also shown in FIG. 3B, the tapered end 5 d of clamp 5 includes a second abutting portion 550 . In addition, opening 5 a includes segments or portions 530 , 535 , 540 , and 545 . As also shown in FIG. 3B, and in more detail in FIG. 3C, the opening segment 530 is conical in shape and is in direct fluid communication with segment 535 . Segment 535 , in turn, is in direct fluid communication with segment 540 , which in turn is in direct fluid communication with segment 545 , which is conical in shape. Segments 530 and 545 have tapered or conical surfaces 520 and 525 , respectively. Segment 530 and conical surface 520 are adapted to receive and snugly fit one end of a ferrule 10 (as shown in FIG. 1). I prefer to have clamps 5 made of 2024 T-4 steel, but those skilled in the art will understand that other metals or suitable materials may be used instead.
[0046] Referring now to FIGS. 4A, 4B, and 4 C, additional details regarding the stator 20 of the valve 1 of the present invention are shown. Referring first to FIG. 4A, a frontal view of stator 20 is provided. As shown in FIG. 4A, the interior seat 210 of stator 20 includes ten (10) tapered openings 201 . Openings 201 are arranged in a circular pattern on the surface of stator 20 . Referring now to FIG. 4B, a sectional view of the stator 20 is provided. As shown in FIG. 4B, a first side of the stator 20 includes a seat 210 . The seat 210 is adapted to snugly fit and hold therein at least a portion of the ferrule support 17 (as is shown in FIG. 1). Referring to FIGS. 4B and 4C, the openings 201 are shown in additional detail. As shown in FIGS. 4B and 4C, openings 201 extend through the stator 20 . Openings 201 each have segments 240 , 230 , and 245 . As shown in FIG. 4C, segment 245 is tapered and provides a conical surface 220 . Segment 230 is in direct fluid communication with segment 245 . Segment 240 , in turn, is in direct fluid communication with segment 230 . Segment 245 and conical surface 220 are adapted to receive and snugly fit a ferrule 10 with a capillary 15 located therein (as is shown in FIG. 1). Segment 230 is adapted to receive and snugly fit a portion of a capillary 15 which may extend from a ferrule. For best results, I prefer that stator 20 be made of zirconia, although other suitable materials may be used.
[0047] Referring again to FIG. 1, the capillary tubes 15 emerge from the ferrule through-holes 5 a and extend up to the stator 20 through-holes 201 so that the ends of the capillaries 15 are, as noted above, substantially flush with the terminus of a tube pocket. The capillary ends disposed in the tube pockets are naturally in the same relative positions in which the ferrules 10 are arranged. That is, the capillary ends are distributed on the stator 20 evenly around the circumference of a circle.
[0048] Referring once more to FIG. 1, the valve 1 shown therein comprises a rotor 26 which abuts the stator 20 . The rotor 26 may be of any number of types. Referring to FIGS. 5A and 5B, the rotor 26 shown therein has a grooved stator contact surface 26 s and a rotor shaft contact surface 26 t . Grooves 28 are formed in the stator contact surface 26 s . As shown in FIG. 1, the rotor contact surface 26 s abuts one side of the stator 20 . Continuing to refer to FIG. 1, the rotor shaft contact surface 26 t is connected to a rotor shaft 30 for varying the angle of the rotor 26 with respect to the stator 20 . By rotating the rotor surface 26 s , the rotor groove(s) 28 may be selectively positioned to establish fluid communication between specific pairs of capillaries 15 . Although not shown, those skilled in the art will understand and appreciate that a center capillary can be used and, if so, the grooves 28 can be formed to allow movement of the rotor 26 to selectively provide fluid communication between the center capillary and one or more of the other capillaries. The rotor 26 shown in FIGS. 5A, 5B, and 5 C may be used when it is desired to establish fluid communication between various pairs of the capillaries 15 . I prefer to use a rotor 26 made of zirconia, but those skilled in the art will understand and appreciate that other suitable materials may be used.
[0049] While the rotor 26 shown in FIGS. 5A, 5B, and 5 C use grooves 28 cut into the rotor surfaces to permit fluid communication between various capillary 15 , any type of fluid communication channel could be provided on the rotor 26 . For example, rather than grooves 28 , a channel could be cut in the body of the rotor 26 so that it has one opening at the center of the rotor and another opening lying along the circle circumference. However, to minimize the dead volume of the valve, grooves 28 cut into the surface of the rotor 26 are preferred as rotor fluid communication channels.
[0050] The grooves 28 on surface 26 s of the rotor 26 can be formed by conventional machining techniques. Alternatively, grooves 28 can be formed by etching of a photolithography mask (photomask). According to this embodiment of the invention, a thin film (or films) is deposited on one face of the surface 26 s of the rotor 26 using conventional techniques. The substrate is then coated with a suitable photoresist, is then exposed using the photomask, and is developed with a suitable developer. This process removes the photoresist from those areas of the substrate which correspond to the desired shape and arrangement of grooves 28 . The substrate is then subjected to a series of steps which remove the masking material not protected by the photoresist, thus exposing the substrate in these areas. A second series of steps is then use to etch the expose substrate to etch the grooves 28 in the substrate. Because the etching process can be carefully controlled to a very high degree of precision, grooves 28 can be created to match very precise size, volume, shape, or other requirements. Moreover, by carefully controlling the size and shape of the grooves 28 , the amount of dead volume can be both minimized and accurately measured, thus giving the operator more information to help design and run accurate analyses, such as by chromatography or mass spectrometry.
[0051] After the etching process is completed, the photoresist and masking layers are removed. At this point, the substrate can be coated with a thin conforming film (or films) selected to obtain the desired chemical and/or physical properties of the substrate surface. For example, a thin diamond-like coating can be applied to increase the surface hardness. Those skilled in the art will understand and appreciate that, depending on the solvents used, the materials being analyzed, and other various parameters, the ability to select desired chemical and/or physical properties (such as hardness, resistance to corrosion, extremely smooth surfaces, and so forth) will provide many advantages. In addition, a precision saw can be used to cut the substrate into individual pieces for rotor 26 , thus allowing a high degree of precision in the alignment and location of grooves 28 on surface 26 s of rotor 26 .
[0052] Referring now to FIGS. 5D, 5E, and 5 F, an alternative embodiment of a rotor 26 ′ is shown. Rotor 26 ′ has a plurality of grooves 28 ′ in a first surface thereof. Grooves 28 ′ allow for selected fluid communication between the ports of the rotor 26 ′.
[0053] Referring now to FIGS. 6A and 6B, additional detail regarding the stator plate 7 is provided. In FIG. 6A, a frontal view of stator plate 7 is provided, while in FIG. 6B a sectional view is provided. As shown in FIG. 6A, the stator plate 7 contains ten (10) openings 610 , which are arranged in a circle. The openings 610 are adapted to receive the cap screws 6 which are used to secure the corresponding clamps 5 (as shown in FIG. 1). Stator plate 7 also includes openings 650 for receiving cap screws 2 to firmly (albeit removably) secure stator plate 7 to one end of the main body 110 of valve 1 (as shown in FIG. 1). As shown in FIG. 6A, the stator plate 7 has three (3) openings 650 for receiving cap screws 2 . As shown in FIG. 6B, stator plate 7 has central opening segments 620 , 625 , 630 , and 644 . In addition, openings 610 have treaded portions for receiving and removably securing cap screws 6 (as shown in FIG. 1). Segments 620 and 625 are adapted for receiving abutting portions of clamps 5 , ferrule support 17 , and stator 20 (as shown in FIG. 1). Segment 644 is adapted to fit and receive sleeve bearing 11 (as shown in FIG. 1). For best results, I prefer that stator plate 7 be made of 316 stainless steel, although other metals and other suitable materials may be used instead.
[0054] Referring now to FIG. 7, a cross section of a ferrule 10 is provided. As shown in FIG. 7, the ferrule 10 has a through-hole 710 extending through its length. The opening 710 is adapted to receive a capillary 15 . As shown in FIG. 7, ferrule 10 is symmetric and has opposing ends 720 and 730 . Referring to FIG. 1, it can be seen that ends 720 and 730 are adapted to fit into openings in the stator 20 and the clamp 5 . (Because the ferrule 10 is symmetric, either end 720 or 730 will fit into the respective openings of stator 20 and clamp 5 .) As also shown in FIG. 7, ferrule 10 has tapered portions 752 and 715 . The tapered portions 725 and 715 are adapted to fit into conical openings in stator 20 and clamp 5 (as shown in FIG. 1). For best results, I prefer to use ferrules 10 made of polyether-ether ketone (PEEK), which is commercially available.
[0055] Referring now to FIGS. 8A and 8B, the ferrule support 17 is shown in additional detail. As shown in FIGS. 8A and 8B, the ferrule support 17 has ten (10) openings 810 , which are generally located in a circle. The openings 810 are adapted to receive and snugly fit ferrules 10 (as shown in FIG. 1). I prefer to have a ferrule support 17 made of PEEK, but any suitable material may be used.
[0056] Returning to FIG. 1, rotor shaft 30 is connected to rotor surface 26 t and is supported by bearing bushing 32 and roller thrust bearing 34 . A spring 36 is used to bias the rotor shaft and rotor 26 toward the stator 20 . A rotor driver pin 40 engages the rotor, and a handle 42 is used for operating the rotor if manual rotation thereof is desired. Obviously, any number of automatic means for rotating the rotor could be connected to the rotor shaft.
[0057] The various components of valve 1 as described above may be fabricated form any suitable material, including thermoset materials and thermoplastics. Polyether-ether ketone (PEEK) is a particularly suitable thermoplastic material for fabricating the ferrules of the invention. The rotor and stator of the inventive valve may be fabricated from any suitable material, for example, metal, plastic materials, ceramic materials, or zirconia. In a preferred embodiment, the rotor and stator are ceramic or zirconia.
[0058] The valve of the instant invention may be fabricated to any useful size. However, the inventive valve is particularly useful in micro applications, in particular those utilizing fluid flow rates of 0.5 ml/min or less. For example, in the preferred embodiment shown above, the valve 1 is able to selectively connect ten (10) capillaries 15 with a port to port distance of 2 mm arranged in a circle with a diameter of 6 mm. The valve 1 of the present invention thus minimizes dead volume while providing a great deal of flexibility and ease of use to an operator because each capillary 15 can be connected or disconnected separately; the cap screws 6 (arranged in a larger circle than capillaries 15 ) can be easily tightened or loosened by an operator. Those skilled in the art will understand and appreciate that more or less than ten (10) ports may be used, and the size of the ports may be greater or less than 2 mm in diameter. The valve 1 of the present invention will be of advantage in the field of capillary chromatography and mass spectrometry. As used herein, the terms “capillary chromatographic system” and “capillary chromatography” shall be understood to refer to systems used for chromatographic analyses or mass spectrometry analyses performed thereon, and the like, which employ(s) one or more capillary columns. As used herein, “capillary column” means a capillary (capillary tube) having an outside diameter from about 50 to about 1600 microns. It will be understood that the capillaries which may be connected to the inventive valve need not be “capillary columns,” although they may be. For example, some of the capillaries may be shorter capillaries which are used to feed or transfer fluids to a capillary column. Those skilled in the art will understand that the terms “chromatographic analysis” and “mass spectrometry analysis,” and the like refer not only to the separation or partial separation of mixtures into their individual components, but also to methods in which a single, pure material is analyzed. In the latter situation, it may technically be the case that no “separation” occurs, because only a single, pure component is present. Further, as noted above a distinction is sometimes made between analytic methods which are performed for analytical purposes and those which are performed for preparative purposes. However, for convenience, the terms “chromatographic analysis” and “mass spectrometry analysis,” and the like, as used herein will be understood to include separations and methods which are conducted for both analytical and preparative purposes.
[0059] Capillary chromatography has long been known for extremely high resolution, and it can be carried out using both gas and liquid mobile phases. In this sense the term “fluid” will be understood, as it normally is, to include both liquids and gases. The valve of the present invention is also useful in high pressure liquid chromatographic (HPLC) applications, including capillary HPLC. Thus, one embodiment of the invention is a capillary chromatographic system, including gas chromatographs and liquid chromatographs, comprising the valve of the invention.
[0060] In another embodiment of the invention, the capillary 15 are fused silica capillaries having an outside diameter of about 365 microns. In other embodiments, the outside diameter of the capillaries is between about 100 and 500 microns, and preferably between about 250 and 400 microns.
[0061] In yet another embodiment, the present invention is a method for carrying out a chromatographic mass spectrometry analysis, comprising: a) inserting one end of a capillary into an opening of a ferrule and the other end of the capillary through a clamp; b) placing a stator in contact with at least one of said ferrules, said stator having a stator front side and a stator flat surface opposite said front side, said stator front side having a plurality of impressions into which some or all of said ferrules are received, each of said impressions opening to a tube pocket, each of said impressions also having a stator through-hole opening onto said stator flat surface; c) disposing a plurality of capillary tubes through said ferrules into said tube pockets; d) applying pressure to said one or more ferrules; e) placing in contact with said stator a rotor comprising a stator-contact surface and a fluid communication channel such that said stator-contact surface abuts said stator flat surface and is rotatable about an axis to establish fluid communication between selected pairs of capillaries through said fluid communication channel; f) placing one or more of said capillaries in fluid communication with a capillary column; g) rotating said rotor to establish fluid communication between said capillary column and one or more of said capillaries; and h) passing a fluid through one or more of said capillaries and into said capillary column. In yet a further embodiment, the present invention is an automated method or automated chromatographic system or mass spectrometry for carrying out a chromatographic or mass spectrometry analysis using the valve of the invention.
[0062] In still another embodiment, the present invention is a method for connecting capillaries to a chromatographic or mass spectrometry system, the method comprising: a) providing a plurality of ferrules, each of said ferrules having a ferrule through-hole; b) disposing a plurality of capillary tubes through said ferrule through-holes; c) inserting the other end of each capillary through an opening in a clamp; and d) providing a plurality of impressions into which said some or all of ferrules are received, each of said impressions having a tube pocket into which one of said capillary tubes extends; and e) applying pressure to said one or more ferrule clusters.
[0063] While the present invention has been shown and described in its preferred embodiment and in certain specific alternative embodiments, those skilled in the art will recognize from the foregoing discussion that various changes, modifications, and variations may be made thereto without departing from the spirit and scope of the invention as set forth in the claims. Hence, the embodiment and specific dimensions, materials and the like are merely illustrative and do not limit the scope of the invention or the claims herein.
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A multi-port valve useful in chromatography or other analytical chemistry processes utilizes a ferrule and clamp assembly to connect a number of tubes or capillaries to a common port in the valve. The use of the clamping assembly, as opposed to conventional connectors such as nuts and/or bolts, permits the capillary ends to be positioned in extremely close proximity to the valve rotor and to each other, thus minimizing the volume between two capillaries when they are in brought into fluid communication with each other. At the same time, the clamps allow for easier connection and disconnection of the tubes or capillaries from the valve body. An operator can twist a screw to tighten the clamp and create a sealed connection without the need for special tools.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. Non-Provisional application Ser. No. 13/568,807, filed Aug. 7, 2012, now allowed, which is a continuation-in-part application of U.S. Non-Provisional application Ser. No. 13/536,013 filed Jun. 28, 2012, abandoned, which claims priority to U.S. Provisional Application No. 61/502,460 filed Jun. 29, 2011, expired, all three of which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of pole supports, specifically including, without limitation, precast concrete pole support bases and methods of manufacture, installation and use.
BACKGROUND
[0003] A wide variety of poles and posts are used throughout the world, including lighting poles, electrical, telephone and cable supports and numerous other poles of many different types. Some of these poles are installed by placing a portion of the lower end of the pole in a hole in the ground and filling the remaining space in the hole with soil, concrete or another suitable material. Many wooden poles are installed using this method in which a portion of the pole is buried in the ground. Other poles and similar structures are intended for installation with the lower end of the pole resting on a separate base, the top of which may be positioned at ground level or above ground level. Metal lamp posts are but one of many such poles, posts and other structures frequently installed on a separate, typically concrete, base.
[0004] Many poles or posts intended for installation on top of a base or support have attached to the bottom of the pole a horizontal square plate or other structure with a “square” arrangement of four holes, with one hole near each of the four corners of the plate or other structure. This provides four fastening holes arranged at the corners of a square so that each hole is equally distant from each of the other two holes adjacent to it. Each of the holes may be located, for instance, in a foot or boss protruding from the side or end of the pole or a plate secured to the lower end of the pole.
[0005] Such a pole is typically installed by securing the plate or other pole-terminating structure with four studs, bolts or other fasteners: (a) protruding vertically from the concrete base and up through the plate or other structure or (b) passing down through the holes in the pole base plate or other structure and into the concrete base. Where studs, pins, bolts or the like are positioned to be received in the holes in the pole base plate or other hole-containing structure, the fasteners must be located carefully during preparation of the base or foundation in order to insure that the fastener spacing matches the locations of the holes in the pole plate or other hole-containing structure. Each stud, pin, bolt or the like is usually the upper end of a long rod or is attached to such a rod or other anchor that extends well down into the base or foundation on which the pole is to be installed.
[0006] If one or more studs protruding from a concrete base are sheered off, as often happens when a motor vehicle collides with a pole mounted on such a concrete base, replacement of the pole may be difficult because of the difficulty of attaching new studs to the concrete base.
SUMMARY
[0007] The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings and each claim.
[0008] This invention provides a pole base, which may be a prefabricated concrete pole base, and that may have an adjustable connection or attachment structure and system of use that is simple to manufacture and install, highly versatile and easy to use. This invention can be used in a wide variety of configurations and alternative structures using numerous known materials and additional suitable materials and components that may be developed in the future.
[0009] The attachment structure is adapted to accommodate pole base plates or other structure having differing dimensions. In one embodiment, an X-shaped arrangement of U-shaped cross section (or inverted T-shaped slot) channels support and attach to the bottom of a pole.
[0010] The channels may be secured to a pole base body that is typically generally cylindrical in shape with generally round, planar top and bottom surfaces. The height may be approximately four times the diameter of the cylindrical body, but many other proportions and shapes are possible. The body may include one or first and second planar recessed regions disposed on opposing sides with inwardly tapered horizontal surfaces on the top and bottom of the recess. Alternate embodiments of the invention may have various proportions of recess depths and sizes and locations. The channels can be embedded in a square or rectangular protrusion from the planar top of the body or can be embedded directly in the top of the body.
[0011] The body may also contain one or more electrical wire chase conduits. The conduits usually run continuous from the top central region of the body and extend downward and exit the body in different desired directions at a side or the bottom.
[0012] A lifting anchor may be fastened to the concrete form so that a portion of it protrudes from the bottom of the body. This anchor or hook facilitates lifting and moving the base during and after manufacture, particularly if the base is manufactured upside down.
[0013] If one or more studs or bolts securing a pole to the concrete base of this invention are sheered or otherwise broken off, as may happen when a motor vehicle collides with a pole mounted on such a concrete base, replacement of the pole may be easy. This is because the sheered stud or bolt can be easily removed from the channel to which it was secure and replaced, and the pole (if undamaged) or a replacement pole can be mounted on the base as described above. Moreover, the pole bases of this invention make it quick and easy to change poles or pole types mounted on the base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Illustrative embodiments of the present invention are described in detail below with reference to the following drawing figures:
[0015] FIG. 1 is an perspective view of the top and a side of one embodiment of the base of this invention.
[0016] FIG. 2 an exploded perspective view of the attachment components incorporated in the base depicted in FIG. 1 , together with the lower portion of a pole and pole base plate of a type that may be installed on the base depicted in FIG. 1 .
[0017] FIG. 3 is a side view of the base of FIG. 1 .
[0018] FIG. 4 is a top view of the base of FIG. 1 .
[0019] FIG. 5 is an “x-ray-like” version of the same a view as FIG. 3 , in which internal structure is visible.
[0020] FIG. 6 is a perspective view of the top of the base depicted in FIG. 1 with lifting tackle positioned for insertion.
[0021] FIG. 7 is a perspective view of the top of the base depicted in FIG. 1 like FIG. 6 but with lifting tackle inserted for lifting the base.
[0022] FIG. 8 is a perspective view similar to FIG. 1 of the top and side an alternative embodiment of the pole base of this invention.
[0023] FIG. 9 is a perspective view similar to FIG. 1 of the top and a side of another embodiment of the base of this invention.
[0024] FIG. 10 is an exploded elevation view of an alternative channel and fastener subassembly of the pole base of this invention.
DETAILED DESCRIPTION
[0025] The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
[0026] One embodiment of this invention is a manufactured or prefabricated, typically concrete pole base with an adjustable connection enabling use of the base to support and stabilize light poles, signs, posts and other monopoles having a range of different sizes of attachment plates or other structures. Other embodiments may not be manufactured or prefabricated remote from the location where used or may have numerous other differences.
[0027] The figures depict an exemplary embodiment of the invention in which a generally cylindrical base 10 has a concrete body 11 having a cylindrical wall 12 , a top 14 , a bottom 16 and two recesses 18 and 20 . Recesses 18 and 20 have rectangular, vertical planar portions 22 that intersect the cylindrical wall 12 at vertical arrises 24 and 26 , the tops and bottoms of which transition to the cylindrical wall 12 along sloping upper transitions 28 and lower transitions 30 , as depicted in FIG. 9 . Alternatively, recesses 18 and 20 can extend all the way from upper transitions 28 through the bottom 16 of the body, as depicted in FIG. 1 .
[0028] As depicted in FIG. 9 , a notch 29 may be cast in the side of body 11 to indicate “grade,” i.e., the depth to which the base 10 is to be buried during installation, where the portion of the body 11 above the notch 29 projects above “grade,” or the level of the ground. Notch 29 can be V-shaped or another shape, and other shapes than a notch may be utilized as such an indicator of grade. Other indicia can also be used, including, for instance and without limitation, a metal piece or other object embedded in and visible in or projecting from the body 11 , and a marking such as paint applied to the base 11 . A recess such as notch 29 formed by mold structure is a practical indicator of grade because it is automatically and accurately incorporated in the body 11 when base 10 is manufactured.
[0029] Structure for attaching a pole to the base 10 is provided by anchors 32 easily seen in FIG. 2 . Each anchor 32 may comprise a section of channel 34 positioned in use horizontally on or in the top of body 11 . Structure attached to the undersides 40 of anchors 32 is embedded, together with a portion of the anchor 32 , in the base 10 to secure the anchor in place. Such securing structure in a first exemplary embodiment depicted in the drawings is two vertical plates 38 and two vertical rods 36 , each of which rods 36 is attached to one of the plates 38 and the underside 40 of one of the channels 34 . Many other securing structures may be used such as the coupling 94 and threaded rod 100 shown in FIG. 10 . Coaxial or aligned pairs of anchors 32 are positioned orthogonal to each other so that the channel axes 42 and 44 and the channels 34 form an X-shape, as may be easily seen in FIG. 4 . This permits a pole 46 having a square base plate 48 penetrated by four corner holes 50 to be attached to the base 10 with four bolts, studs or other fasteners 52 typically (but not necessarily) having rectangular heads 54 , one of which heads 54 is received in each of channels 34 . Because the fastener heads 54 can be positioned in the channels 34 anywhere along the length of the channel, base plates 48 of different sizes can be attached to base 10 , provided that the base plate 48 can be positioned so that each of the holes 50 in the base plate 48 is over a portion of one of the channels 34 . The same is true of pole attachment holes in other pole termination structures.
[0030] As an alternative to bolts, studs or other fasteners 52 positioned with heads 54 received in the channels 34 , “T-nuts” and other internally threaded fasteners can be positioned in the channels, and bolts or other fasteners 52 can be passed down through the holes 50 in pole base plate 48 , or through other hole-containing structure of pole 46 , and into the T-nuts or other internally threaded fasteners.
[0031] The base 10 is formed with the channels 34 of anchors 32 at the top 14 of the body 11 and with rods 36 and plates 38 imbedded in the concrete or other material of which the body 11 is cast or otherwise formed. Concrete or other material of which the body 11 is formed can also be positioned between the channels 34 to form an integral monument-like structure 41 on the top of base 10 , or the channels can be partially or fully embedded in the body 11 .
[0032] The X-shaped arrangement of anchors 32 for securing a pole base plate 48 can be attached to other structures such as poured-in-place and prefabricated bases, concrete pads, or building, dam, parking lot, pedestrian walkway, landscaped area, street or road components. Anchors 32 can also be configured as channels secured to other components by bolts, studs or other fasteners passing through or attached to the bottoms 35 or sides 37 of channels 34 .
[0033] In addition to the anchors 32 , reinforcing structure 56 , conduits 58 , other desired structures such as an anchor or hook 60 can be imbedded in body 11 to reinforce and strengthen the body 11 , facilitate connection of electrical or other devices in or on the pole 46 to power sources, controls or other devices and provide lifting structure.
[0034] Reinforcement 56 (visible in FIG. 5 ) can include vertical rebar 62 and generally horizontal, square rebar stirrups 64 . These vertical and horizontal members can be held together for placement in the concrete mold with rebar tie wires, can be welded or can be separate components.
[0035] Conduit 58 can run from the top 14 of the body 11 inside the channels 34 , down the inside of the body 11 and out through a side of the base 10 through cylindrical wall 12 or one of the planar portions 22 or 28 of one of the recesses 18 or 20 . Such positioning of an upper end 68 of conduit 58 in a central location inside the body 11 and channels 34 positions wires or other structures positioned in the conduit 58 to travel directly up the inside of pole 46 . While the conduit 58 can bend inside the base and exit to the side, conduit 58 could also exit the bottom 16 of the base 10 .
[0036] Junction boxes or other desirable structures or components can be positioned on or in body 11 as may be desirable to achieve additional or improved functionality.
[0037] Base 10 may be manufactured utilizing a concrete form having multiple connected panels that, when connected, define voids in which embedded structures like reinforcement 56 , portions of anchors 32 and conduit 58 are positioned and into which the concrete mixture or other material from which the base is formed is poured. Such a form may be a clam-shell opening form or any other form suitable for manufacturing concrete structures like base 10 .
[0038] Alternate embodiments of the invention may have various proportions of recess depths and sizes, thereby allowing for the addition or subtraction of mass and thus weight to the body as needed and to provide roll-resisting structure and for other purposes.
[0039] Anchors 32 with fastening channels 34 may be “Halfen,” “Unistrut” or other similar anchoring channels having a generally U-shaped cross section. Lips on the opposed inside ends of the “U,” together with inside walls of the channel form an inverted T-shaped slot and retain appropriately shaped nuts and bolt heads. Such fasteners are sometimes referred to as “Tee-nuts” and Tee-bolts.” Anchors 32 also may be obtained from other suppliers or can be fabricated for this application. Anchors 32 can be a wide variety of different sizes and can have a wide variety of different forms provided that the anchor provides structure for attachment of a nut, bolt, stud or other fastener structure that is securely attached or anchored to the base 10 .
[0040] The channels 34 are positioned in horizontal positions at the top of the body 11 in a generally X-shaped arrangement, with the outer ends of the channels at the corners of the protrusion or monument 41 at the top 14 of the body 11 , and the inner ends 35 of channels 34 facing the center of the protrusion 41 . The protrusion 41 is typically square but can also be a rectangle or another shape and can be omitted so that the channels 34 simply sit on top of the body or are partially or fully embedded (as depicted in FIG. 8 ) in the top of body 11 of pole base 15 . If the channels 34 are embedded in the body 11 , the outer ends 39 of channels 34 may be flush with the wall 12 of body 11 as shown in FIG. 8 , but they need not necessarily be flush with the wall 12 .
[0041] While it can be beneficial for the outer ends 39 of channels 34 to be open to provide access for positioning or securing fasteners, they need not necessarily be open and can be embedded in the body 11 of base 10 or 15 if either the inner ends of the channels 34 are open so that fasteners can be introduced through the inner ends or if the base 10 or 15 is manufactured with fasteners already positioned in the channels 34 .
[0042] The fastening channels 34 each have one or more structures, which can be one or more anchoring bars 36 or plates 38 (see FIG. 2 ) or other shapes (see FIG. 10 ), fastened to the bottom 40 of the channel 34 and extending downward into the body 11 , thereby acting to strengthen the connection between each channel 34 and the body 11 . The fastening hardware (typically tee-head bolts or studs or nuts) used to fasten the base of the pole to the channels may be common hardware used in Halfen, Unistrut or similar anchoring structures.
[0043] Such Halfen, Unistrut or similar anchors 32 will typically include a channel 34 having a generally U-shaped cross section with an open top forming an inverted T-shaped slot. The channels 34 need to be open at least one end and may have a length typically somewhat less than half of the radius of the cylindrical base 10 ; however, other anchor structures and dimensions may be used.
[0044] Having the center of the “X-shaped” anchor 32 channels 34 open provides an unobstructed region for the conduits 58 to open to the top of the base 10 . However, a complete “X-Shaped” structure could be used by having equal length channels 34 that meet in the middle or by having one longer channel 34 and two shorter channels 34 abutting the longer channel on opposite sides in its middle. If one longer and two shorter channels 34 are used, two of the fasteners 52 will be secured in the longer channel 34 , and one will be secured in each of the shorter channels 34 . Conduits 58 could open to the top of body 11 just to one side of the abutting channels 34 in these alternative configurations.
[0045] If abutting channels are welded or otherwise attached to the channel they abut, the desired orientation of the “X-shaped” channels 34 structure can be easily maintained during manufacture of the base 10 . Where the channels 34 do not abut, other means will have to be used to maintain the proper relative orientation of the channels during manufacture of the base 10 or during incorporation of the anchors 32 in another structure.
[0046] An alternative channel and fastener structure is depicted in FIG. 10 . In this alternative, channel 76 is similar to channels 34 , but depending sharp or v-shaped lips 78 extend downward from the inward-extending tops 80 of the channel 76 , forming inverted v-shaped recesses 84 between the side walls 82 and the lips 78 . These recesses 84 receive protrusions 86 on square or rectangular washers 88 through which bolts 90 pass into nuts 92 . This arrangement of components and structures can provide especially strong attachment structures, particularly including resistance to force exerted on the fasteners, because, among other reasons, of the engagement between the lips 78 of channel 76 and protrusions 86 of washer washers 88 .
[0047] Channel 76 rests on and is welded (e.g. with weld bead 102 ) or otherwise appropriately attached to a threaded coupler 94 . In the embodiment of coupler 94 depicted in FIG. 10 , a plate 96 to which the channel 76 is attached is welded to or otherwise attached to or formed with a threaded collar 98 . Threaded rod 100 seated in collar 98 extends down into the concrete of body 11 . One, two or any other suitable number of threaded couplers 94 and rods 100 may be attached to each channel 76
[0048] A lifting anchor 60 visible in FIG. 5 is fastened to the main concrete form (not shown) in a manner so as to dispose it at the bottom 16 of the body 11 , sufficiently inward from the wall 12 of the body 11 to allow a substantial portion of the anchor 60 to be embedded in the body 11 . The lifting anchor 60 may vary in type and size while still performing the intended purpose and function of providing a structure by which base 10 can be lifted.
[0049] The reinforcing structure 56 is positioned in the form (not shown) prior to the introduction of concrete mixture or other material of which the body is formed and will serve to reinforce the structural integrity of the base body 11 when the fabrication process is complete. Reinforcement 56 may be comprised of one or a multitude of steel reinforcement members in the form of a single reinforcing member or a framework of multiple reinforcing members that form a structure having a diameter, length, width, and height that are sufficiently less than the diameter, length, width, and height of the interior volume of the body 11 to insure that concrete completely surrounds the reinforcement 56 . Reinforcement structure 56 may be constructed of a variety of different suitable materials including but not limited in use to, metals, polymers, fiberglass, carbon fibers, metal/plastic composites, and other materials that perform the same desired functions.
[0050] After positioning of all components within the concrete form, a concrete mixture, typically but not necessarily a high grade concrete mixture, is poured into the main concrete form, surrounding the entirety of the main interior reinforcing components.
[0051] Once the concrete is at least partially cured or hardened, the base 10 is removed from the form, is allowed to cure fully and, optionally, is finished by a variety of methods including but not limited to, texturing, staining, etching, polishing, glazing, sealing, color coating, and other finish methods.
[0052] Body 11 may be manufactured using concrete of numerous types and composition mixes having various combinations of ingredients such as cement, water, cementitious materials, and chemical and or mineral admixtures or coloring agents. Concrete usable for manufacturing the concrete base of this invention may be regular concrete, including high grade concrete, and it may be polymer concrete or a wide variety of other concrete types, including, without limitation, high strength concrete, high performance concrete, ultra-high-performance concrete, glass concrete, asphalt concrete, rapid strength concrete, geopolymer concrete and green concrete. Other types of concrete and materials other than concrete also may be used, provided that such materials provide appropriate mass, strength and ability to hold the channels and other components required for the poles to be supported and the conditions of the intended installation.
[0053] Body 11 and base 10 may be manufactured in a variety of shapes other than cylindrical, including, but not limited to, triangular, square, pentagonal, hexagonal, heptagonal, octagonal, rectangular or any other polygonal shape, or ovoid, elliptical or another rounded shape, as viewed from the top or in cross section. Body 11 and base 10 shapes other than round may resist rotation in situ better than entirely round shapes. Body 11 may be irregular along its length and may have yet other shapes, including, for instance, a truncated cone tapering from its bottom up, as well as other shapes that provide the needed strength, stability and other properties desired or needed for a particular pole base.
[0054] This invention is intended to be used for applications including, but not limited to, as a mounting and stabilizing support for light poles, sign posts, sign panels, traffic light poles, flag poles, radar equipment mounting poles, communication equipment mounting poles, solar panel array mounting poles, wind turbine poles, or other applications for mounting, support and stabilization.
[0055] The X-shaped configuration of channels (easily seen in FIG. 2 ) can be used in cast-in-place concrete or other structures to provide the attachment structure for a variety or range of base plate 48 sizes and bolt receiving hole 50 spacings.
[0056] Pole base 10 may be installed by lifting the base 10 by a lifting harness 72 attached to eye-bolts, Tee-cross section slot-fillers 74 or other hardware temporally attached to one or more of channels 34 , as depicted in FIGS. 6 and 7 . The base 10 is lowered into a previously excavated hole. Soil, concrete or other suitable fill material is then placed in the hole to secure the base in an upright position. If the body 11 has any recesses 18 or 20 , the fill material will occupy such recesses.
[0057] A pole having a square arrangement of stud or bolt-receiving mounting holes, such as pole 46 , may be installed on the base 10 by positioning one anchor bolt or stud 52 in each of the four channel sections 34 (as shown in FIGS. 3 and 4 ) with an end of each stud facing upward and positioning the pole base 48 above and near the channel sections 34 . Before or after positioning the pole base 48 near the channel sections, each of studs 52 may be slid into and positioned in the channel 34 within which it is located so that the stud 52 can be received in one of the pole base holes 50 . The pole 46 may then be lowered so that the pole base 48 holes 50 receive the studs 52 with one of the studs 52 positioned in each of the four base structure holes 50 . The fasteners are then tightened so as to hold the pole base 48 securely connected to the channels.
[0058] Alternatively, as is generally illustrated in FIG. 10 , the nut and bolt can be turned over so that a bolt shank is passed through the top of a pole base, into a channel and into a nut or washer and nut in the channel.
[0059] Furthermore, the base of this invention can be manufactured with channels having numerous other cross-sectional shapes provided that an X-shaped arrangement of channels is provided to accommodate differing sizes and hole or fastener arrangements in pole bases.
[0060] Other embodiments of the pole base of this invention may use fastener arrangements that are not adjustable together with other aspects of the invention described and/or depicted herein and in the accompanying drawings.
[0061] The ability of the base 10 of this invention to receive and securely hold poles with different sizes of square arrangements of mounting holes, affords versatility in use of the base and permits a first pole mounted on the base to be replaced by a pole with different size hole arrangements. It also permits a damaged pole or a pole secured with damaged or broken studs to be replaced or remounted without replacing or repairing the base.
[0062] Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and subcombinations are useful and may be employed without reference to other features and subcombinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications can be made without departing from the scope of the claims below.
[0063] For instance, one or both of the recesses 22 can be omitted or can have different proportions and different shapes. Where there are two recesses 22 , they do not have to have the same shape.
[0064] “Soil” used to backfill a hole within which a pole base of this invention is positioned can be any fluid, granular or similar material suitable for securing the pole base in a stable, upright position so that the base can resist any uplift or tilting forces exerted on the base or a pole attached to it. Accordingly, “soil” includes earth, dirt, stone or other aggregate, concrete and any other suitable material. Holes within which pole bases of this invention are positioned can be excavate in undisturbed earth (including loose soil, stone, rock and other materials), in fill, in other naturally occurring or human-made structures like parking lots.
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A prefabricated concrete pole base and adjustable method of connection and use to receive, support, and stabilize light poles and the like having different hole mounting patterns, securing the pole to the base and facilitating rapid installation of poles while eliminating the need for on-site concrete forms and lengthy concrete cure times.
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REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional application Ser. No. 60/881,360, filed Jan. 19, 2007 and entitled Axial Centerline Following Display Of CT Colonography Images, which is incorporated herein in its entirety by reference.
TECHNICAL FIELD
[0002] The invention is a method and system for processing colonography image data and displaying colonography images.
BACKGROUND
[0003] Colonography, the use of electronic imaging technologies such as computed tomography (CT) to generate images of a patient's colon for purposes of colorectal cancer screening, is generally known. By way of example, these technologies are disclosed in the Johnson et al. U.S. Pat. Nos. 6,928,314 and 7,035,681, the Zalis U.S. Pat. No. 6,947,784, the Vining U.S. Pat. Nos. 6,909,913 and 7,149,564, and PCT publication no. WO 2007/030132, all of which are incorporated herein by reference. Briefly, this methodology involves obtaining a series of CT images of adjacent portions or slices of the colon. A radiologist then studies each of the images to identify any pre-cancerous polyps. Alternatively, a computer can effectively create a simulated intraluminal flight through the colon (this is also known as virtual colonoscopy). Colonography has been demonstrated to be a highly efficacious approach for detecting colorectal polyps.
[0004] Readers of CT colonography images sometimes prefer to maintain a small field of view, to maximize conspicuity of small polyps. However, this requires them to manually follow the colon throughout the abdomen and pelvis. Manually following the colon as it curves through the body can at times be difficult and may distract the reader from his or her primary task, which is to locate polyps and lesions within the colon. The reader may also sometimes recenter the segment of interest in the workstation display, further complicating the primary task. Conversely, the need for recentering may be reduced if the image is viewed at a large field of view, but then any polyps may be more difficult to identify.
SUMMARY
[0005] The invention is an improved method and system for processing and displaying colonography image data. In one embodiment of the invention the image data is processed to identify a centerline of the colon. A series of axial image data sets representative of images of the colon at sequential locations along the centerline is generated. Each image is generally centered on the centerline and presents a field of view parallel to an axial plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an image of a colon with a centerline traversing the length of the colon.
[0007] FIGS. 2A-2C are axial centerline-following images of a colon at a series of sequential positions within the colon in accordance with one embodiment of the invention.
[0008] FIG. 3 is a schematic illustration of the imaging method of the invention.
DESCRIPTION OF THE INVENTION
[0009] This invention is a display technique based on automatic generation of a midline trace or centerline of the colon and then display of a sequence of images that are centered on this trace and follow along it. Such a trace is shown in FIG. 1 , and many techniques for generating such a trace are known and described in the literature. A relatively small (and in some embodiments adjustable) field of view of an axial or transverse slice is displayed around the current centerline position. The radiologist controls the centerline position currently being observed with a mouse, slider bar or other keyboard or GUI control. As the radiologist advances through the centerline, the image shown is constantly updated to be from the slice corresponding to the current centerline position and centered on its location. FIGS. 2A-2C illustrate axial centerline following, displaying sample views at three closely spaced points along the centerline in the transverse colon. The field of view is approximately 80 mm wide. As the radiologist scans along the centerline, the current centerline point (bright dot in the figure) remains at the center of the image, and a small field of view is displayed around it, maintaining the current segment of interest in the center of the display.
[0010] The field of view (FOV) is preferably large enough to show sufficient detail in the image, yet small enough that the reader can view the image relatively quickly. The appropriate size FOV can be determined. Alternatively, GUI or other controls can be installed to make this adjustable by the user. Axial slices centered on sections of the colon parallel to the axial plane may not allow the reader to see polyps located on the colon wall a few slices away. One approach to alleviate this issue is to automatically page back and forth several slices in the axial direction while in the transverse colon. The transverse colon can be identified automatically by measuring the angle of the centerline tangent relative to the XY plane. Another solution is for the reader to manually pause the centerline following and page back and forth manually. The use of sagittal and coronal views for the centerline following can also be implemented. Such a display system can automatically keep track of whether all necessary slices have been viewed, and alert the user when some areas of the colon have not been observed. The invention can help keep the observer's attention focused on the colon, and display the colon at an optimal size for lesion detection. This can result in faster reading times with less disruption of concentration, and may yield both time savings and improvements in accuracy.
[0011] FIG. 3 is a schematic illustration of axial colon following in accordance with the invention. Image slices are generated in the transverse orientation and are centered in the lumen.
[0012] Although the invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.
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A method for displaying colonography images includes presenting a series of axial images of the colon at sequential locations along the colon centerline. Each image is generally centered on the centerline and presents a field of view parallel to the axial plane.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a kind of disc storage case with a self-locking security structure at the opening position. The case described herein can help protect the legal rights and interests of the disc issuers and enhancing the consumers' ability in identifying the authorized discs, so as to prevent pilferage and distinguish originals from fakes.
2. Description of the Related Art
A disc storage case is usually composed of a case bottom, a case back, and case cover. The main function is for storing discs and protecting the disc from being damaged. Currently, most disc cases in the market do not have a security structure, thus it can be opened easily without damaging the case in any link of the distribution, and the disc may easily be subjected to theft and secret substitution. As a result, the issuers can hardly protect their legal rights and interests and the customers have difficulty in determining the genuineness of the discs, either.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a kind of disc storage case with a security sign. When the case is opened for the first time, the sign will be damaged, so that the disc can't be stolen or changed by the lawbreakers during the course of distribution.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become fully understood from the detailed description given herein below illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows the open state of the disc storage case of the present invention before packing;
FIG. 2 shows the security board in the present invention;
FIG. 3 shows the locking pin in FIG. 2 ;
FIGS. 4 , 5 , and 6 show the locking course of the security board;
FIG. 7 shows the handle for tearing the security board;
FIG. 8 shows the closing state of the case cover and case bottom after the security board is damaged; and
FIG. 9 shows the open state of the disc storage case of the present invention after the security board is damaged.
DESCRIPTION OF THE INVENTION
FIG. 1 shows a typical embodiment of disc storage case of the present invention, including case cover 1 , case back 2 , and case bottom 3 , which are connected by the folding V-shaped trough 4 . In addition, a security board 5 , through which it can be judged whether the disc storage case is ever opened or not, is set at the outer side of the case cover 1 .
As shown in FIG. 2 , security board 5 includes handle 7 that is connected to the outer side of the case cover 1 by the folding V-shaped trough 6 and locking board 9 that is connected to the handle 7 by the folding V-shaped trough 8 . An anti-withdrawal locking pin 10 is set on the locking board 9 . At the end of the handle 7 is the handle hole 21 . As shown in FIG. 3 , at the end of the locking pin 10 is the arrow cone 22 , on the top of which is the flute 23 . As shown in FIG. 1 , at the outer side of the case bottom 3 is the locking jack 11 corresponding to the locking pin 10 . The horizontal dimension of the arrow cone 22 is greater than that of the jack 11 .
As shown in FIG. 1 , on both ends and outer side of case cover 1 is the vertical side 12 , which is vertical to the case cover 1 . On both ends as well as the outer side of the case bottom 3 is the vertical side 13 which is vertical to case bottom 3 and corresponds to the vertical side 12 of case cover 1 . The section of the vertical side 12 of case cover 1 corresponding to the security board 5 is the inward concave section 14 . On the vertical side 13 of the case bottom 3 is the concave section 15 corresponding to the concave section 14 . Locking jack 11 lies at the side near the bottom of the concave section 15 . The concave width of the concave section 15 of the case bottom 3 is slightly smaller than that of the concave section 14 of the case cover 1 , thus when case cover and case bottom are engaged, the concave section 15 of the case bottom lies outside, and the concave section 14 of the case cover lies inside. The purpose of setting concave sections 14 and 15 is that before the formal packing, the security board 5 and the locking pin 10 and some other structures which are located on the security board 5 can be received in the concave, so that the security board 5 can be turned to the position parallel to the vertical side 12 , and the packaging size of the storage case before formal packing can be reduced. Additionally, it can avoid the damage of the security board and error self-locking during the course of packaging and transportation of the empty cases. On the vertical side 12 are several raised bars 16 for orientation, and on the vertical side 13 are several flutes 17 corresponding to the raised bars 16 . When the case cover and bottom are engaged, the raised bars 16 penetrate into the flutes 17 , thus the case cover can be fixed.
As shown in FIG. 1 , when case cover 1 and case bottom 3 are engaged, the vertical side 12 of the case cover 1 lies inside, and the vertical side 13 of the case bottom 3 lies outside. On the vertical side on the both ends of the case cover 1 is the flute 18 for positioning, and on the inner side of the vertical side on both ends of the case bottom 3 is the protruding slice 19 corresponding to the flute 18 . The height of the vertical side 12 of the case cover 1 is smaller than that of the vertical side 13 of the case bottom 3 . On the inner side of the vertical side of the case bottom 3 is the rigid supporting base 20 for bearing the case cover 1 . The central part 24 of the vertical side on both ends of the case cover 1 is of an arc protruding shape, which not only looks handsome, but also increases the strength of the central part of the case end. Thus the case cover can't be pried up from the middle part, and the disc won't be stolen or changed.
Resorting to the attached drawings, the using procedure of the disc storage case of the present invention is described as follows:
1. Put into the Disc and Encapsulate the Disc Storage Case
Firstly, open the disc storage case, lightly put the central hole of the disc to the disc supporting base 25 of the storage case as shown in FIG. 1 , turn over the case cover 1 , then the case cover 1 and the conjoined security board 5 gradually shift towards the case bottom 3 . The arc heave 24 on both ends of the case cover 1 contacts the vertical side 13 at the end of the case bottom 3 and conducts radial guiding, when the positioning flute 18 on the case cover 1 touches the positioning protruding slice 19 on the case bottom 3 , the case cover 1 is to be axially positioned. When the axial positioning here is to be finished, with the case cover 1 shifted more, the vertical side at the outer side of the case cover 1 touches the supporting base 20 at the inner side of the outer section of the case bottom 3 . The case cover 1 is repositioned axially. When the case cover 1 and the case bottom 3 are closed completely, the protruding bar 16 on the case cover 1 joggles with the flute 17 on the inner side of the vertical side of the case bottom 3 , at which point the disc storage case is completely closed. Next, the security board 5 is turned back downwardly. The handle 7 , locking board 9 , and the locking pin 10 on it are shifted downwardly. When the arrow cone 22 on the top of the locking pin 10 reaches the locking jack 11 on the case bottom 3 , it enters the guiding positioning state before locking. At this time, the security board 5 is received outside the concave section of the case cover 1 and case bottom 3 . With the action of proper force, the locking jack 11 forces both limbs of the arrow cone 22 to deform towards the central flute 23 . The arrow cone 22 gradually penetrate into the locking jack 11 , then with the action of its own bounce, both limbs of the arrow cone 22 resume normal operations. It can't be withdrawn because it is blocked inside the locking jack 11 . Thus the disc is put in and the packing is also accomplished (Refer to FIG. 4 , FIG. 5 , and FIG. 6 ). To guarantee that the locking pin 10 can insert into the locking jack 11 smoothly, the front of the locking jack 11 is designed into a bugle shape (Refer to FIG. 4 ).
2. Open the Disc Storage Case and Take out the Disc
After purchasing the well-packed disc, the user can lightly raise the end of the handle 7 of the security board 5 with a finger, and then put the finger into the handle hole 21 . Thus, the handle 7 can be torn along the V-shaped trough on both sides. Then the connection of the case cover 1 and the case bottom 3 at the position of the security board 5 is relieved, and the storage case is unlocked. The user can then open the case cover 1 and take out the disc in the case (Refer to FIG. 7 , FIG. 8 , and FIG. 9 ).
When the handle 7 is torn when opening the case, the security board 5 is damaged, and the disc storage case can't resume the state before it is unlocked. Therefore, the consumers needn't worry that the disc inside is once changed if the packaging is complete. Additionally, it is very convenient to deposit or take out the disc after the security board 5 is torn.
To ensure that the handle 7 can be torn by hand successfully, appropriative unsealing tools can be prepared, such as special cutting tool. If for the causes of material or technique, the strength of the V-shaped groove on both sides of the handle 7 is not weak enough that the handle can be torn easily, the consumer can use the special cutting tool to cut the V-shaped trough, and then tear it.
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This invention relates to a security type disc storage case, including case cover, case back, and case bottom, which are connected by a folding V-shaped trough, characterized in that a security board, through which it can be judged that whether the disc storage case is once opened, is set at the outer side of the case cover. After the disc storage case is packed, the security board, case cover, and case bottom are connected together, which means the case is never opened. After purchasing the disc stored in such a case, the consumer can tear part of the security board, then the case cover can be opened freely, and the disc inside can be taken out or put in conveniently.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims priority from IL Patent Application 215501, filed Mar. 10, 2011, entitled, “Irrigating Plants with Salty Water” which is incorporated herein by reference.
FIELD OF THE APPLICATION
[0002] The present invention relates generally to plant growing systems, apparatus and methods, and specifically to systems, apparatus and methods of enabling plants to grow under conditions of high salinity.
BACKGROUND OF THE INVENTION
[0003] The present invention describes means and methods for growing plants in high salinity or brackish water.
[0004] Crop growth is inhibited by high salt, and various techniques have been employed to extend the maximum salinity range in which plants may be grown.
[0005] GB808645A discloses a process for treating water used for irrigation purposes relates to electromagnetic means for reducing salt in irrigation supply networks.
[0006] U.S. Pat. No. 4,687,505A provides a method for the desalination and reclamation of irrigated soils through application to the soil of minute amounts of one or more anionic compounds having threshold properties in dilute aqueous solution.
[0007] In DE3344945A the invention relates to a method and device for soilless raising and cultivation of plants, preferably in the open, on slanting: planes which are created by securing and sealing the ground surface, and in which the roots of the plants are supplied nutrients dissolved in a running water flow.
[0008] EP1334781 A discloses a method of treating sediment spread over large areas selection of a plant species (12) which is resistant to salinity and able to vaporise considerable amounts of water and absorb the pollutants present in the soil, (c) sowing and cultivation in the area of a plant species (12) so that its roots form a close-knit web in the soil,
[0009] US2010186298A reports methods for cultivating, plants includes placing a plant body to be cultivated on a film laid on or in water-containing, soil and substantially getting integral with the roots of the plant body appropriately together with a plant cultivation supporting body, supplying water and fertilizer to the ground soil under the film, and appropriately supplying water and/or fertilizer also above the film after the roots of the plant body and the film are substantially integrated.
[0010] EP2116130A discloses a hydroponic watering system for pluriannual tree and hush plantations, wherein the water bulb where the roots of the tree are fed, is situated on the ground or partially buried, in a container that is waterproof and dark in colour to prevent sunlight from affecting the normal development of the roots.
[0011] CN102057854A discloses a big seedling transplanting method for inshore saline-alkali land. Irrigation with large amounts of water to remove salt and reduce alkali, is done to provide favourable conditions for reducing salt.
[0012] There remains a long felt and unmet need to provide means and methods for growing plants in high saline or brackish water.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to disclose a method of growing plants in high salinity, said method comprising steps of obtaining a pressurised cultivation system (PCS) having a pressure vessel for growing at least one plant on a media, said pressure vessel housing at least the roots of said at least one plant, a source of saline water and a high pneumatic pressure production unit operatively connected to said pressure vessel for providing higher than ambient pressure to said pressure vessel, thereby maintaining said roots of said at least one plant under high pressure during growth; planting a plant in the pressure vessel such that at least a portion of said roots are hermetically sealed within said pressure vessel; providing saline or brackish water to said media and pressurising said vessel
[0014] It is an object of the present invention to disclose the aforementioned method wherein said method further comprises steps of providing said pressure vessel with an opening such that said opening is hermetically sealable around a part of said at least one plant such that the lower portion of said at least one plant is in said pressure vessel whilst the upper portion of said at least one plant is in the ambient environment.
[0015] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one pressure release valve.
[0016] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one pressure release valve.
[0017] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one pressure sensor.
[0018] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one sensor selected from the group consisting of water salinity sensor, humidity sensor, light intensity sensor, temperature sensor, oxygen sensor, leaf transpiration sensor or any other pertinent sensor for the plant or the media or substrate or atmosphere or environment in which the root or rhizosphere is grown.
[0019] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one water flow valve at the inflow to said pressure vessel.
[0020] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one water flow valve at the outflow of said pressure vessel.
[0021] It is an object of the present invention to disclose the aforementioned method wherein said system is adapted for growing several plants from a single pressure vessel.
[0022] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with a battery of pressure vessels.
[0023] It is an object of the present invention to disclose the aforementioned method wherein said system is adapted for growing plants by any method from the group consisting of soiless culture, aeroponics, aquaponics, aquascaping, Hydroponics, Passive hydroponics or any combination thereof.
[0024] It is an object of the present invention to disclose the aforementioned method wherein said system is adapted for growing plants by any method selected from the group consisting of soiless culture, methods of growing detached from the soil, Aquatic gardening, •Bottle gardening, bubbleponics, Deep water culture, Ebb and flow methods, fogponics microponics, Nutrient film techniques, Organic hydroponics, •Sub-irrigated planter methods or any combination thereof.
[0025] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel is provided with at least one media or substrate selected from the group consisting of soil, growstones, charcoal, Coco peat, peat moss, Coco fibers, Diatomaceous earth, Gravel, Perlite, Pumice, Rockwool, Sand •Vermiculite, Parboiled rice hulls, dolomites, basalt, expanded clay, aggregate, chalk, limestone, artificial polymer substrates, organic matter, mineral medium, organic medium and inert medium and any combination between them or any proportion thereof.
[0026] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with at least one accessory selected from the group consisting of Drip irrigation components growlight, hydroponic dosers, Irrigation sprinklers, Leaf sensors, Net-pots, Spray nozzles, Timers, Ultrasonic foggers, Water chillers.
[0027] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel comprises an inflatable balloon open at one hermetically sealable end for enclosing said roots. In some embodiments all the root system may be enclosed, or single root branches, or parts of root branches.
[0028] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel comprises an inflatable sleeve open at at least two hermetically sealable ends for enclosing around said roots such that at least a portion of said roots protrudes from beyond at least one said sleeve opening. As in the aforementioned embodiments, all the root system may be enclosed, or single root branches, or parts of root branches.
[0029] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel is adapted to be fitted to positively or negatively gravitropic aerial roots.
[0030] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel is adapted to be retrofitted to a crop, plant, shrub, bush, sapling or tree which is growing in a field.
[0031] It is an object of the present invention to disclose the aforementioned method wherein said pressure vessel is adapted to be fitted to a root of a scion or rootstock of a grafted plant.
[0032] It is an object of the present invention to disclose the aforementioned method wherein said PCS is adapted to enable salt water to recirculated and fresh nutrients may be added as required or according to a specific protocol.
[0033] It is an object of the present invention to disclose the aforementioned method wherein said salt water is provided under high pressure.
[0034] It is an object of the present invention to disclose the aforementioned method wherein several pressure vessels are networked in an integrated system controlled by a central controller.
[0035] It is an object of the present invention to disclose the aforementioned method wherein more than one fields or greenhouses or growing establishments are networked in an integrated system controlled by a central controller.
[0036] It is an object of the present invention to disclose the aforementioned method wherein the system is further comprises a central controller and a central server adapted to receive plant physiology, plant growth, plant health or other relevant agrotechnical or agricultural data from at least some plants fitted with said pressure vessels.
[0037] It is an object of the present invention to disclose the aforementioned method wherein said system is further provided with a processor for processing said plant physiology, plant growth, plant health or other relevant agrotechnical or agricultural data.
[0038] It is an object of the present invention to disclose the aforementioned method wherein said system is provided with a computer readable medium for providing instructions to the controller to adjust the pressure in the aforementioned pressure vessels in a predetermined manner.
[0039] It is an object of the present invention to disclose a pressurised cultivation system (PCS) for growing plants in high salinity having a pressure vessel for growing at least one plant on a media or substrate, said pressure vessel housing at least the roots of said at least one plant, a source of saline water and a high pneumatic pressure production unit operatively connected to said pressure vessel for providing higher than ambient pressure to said pressure vessel, thereby maintaining said roots of said at least one plant under high pressure during growth.
[0040] It is an object of the present invention to further disclose the aforementioned system wherein said pressure vessel is provided with an opening such that said opening is hermetically sealable around a part of said at least one plant such that the lower portion of said at least one plant is in said pressure vessel whilst the upper portion of said at least one plant is in the ambient environment.
[0041] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one pressure release valve.
[0042] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one pressure sensor.
[0043] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one water salinity sensor.
[0044] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one water flow valve at the inflow to said pressure vessel.
[0045] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one water flow valve at the outflow of said pressure vessel.
[0046] It is an object of the present invention to disclose the aforementioned system wherein said system is adapted for growing several plants from a single pressure vessel.
[0047] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with a battery of pressure vessels.
[0048] It is an object of the present invention to disclose the aforementioned system wherein said system is adapted for growing plants by any method from the group consisting of soiless growth, aeroponics, aquaponics, aquascaping, hydroponics, passive hydroponics or any combination thereof.
[0049] It is an object of the present invention to disclose the aforementioned system wherein said system is adapted for growing plants by any method selected from the group consisting of soiless culture, Aquatic gardening, •Bottle gardening, bubbleponics, Deep water culture, Ebb and flow methods, fogponics microponics, Nutrient film techniques, Organic hydroponics, •Sub-irrigated planter methods or any combination thereof.
[0050] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel is provided with at least one media or substrate selected from the group consisting of soil, growstones, charcoal, Coco peat, peat moss, Coco fibers Diatomaceous earth, Gravel, Perlite, Pumice, Rockwool, Sand •Vermiculite, Parboiled rice hulls, dolomites, basalt, expanded clay, aggregate, chalk, limestone, artificial polymer substrates, organic matter, mineral medium, organic medium and inert medium and any combination between them or any proportion thereof.
[0051] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with at least one accessory selected from the group consisting of Drip irrigation components growlight, hydroponic dosers, irrigation sprinklers, leaf sensors, net-pots, spray nozzles, timers, ultrasonic foggers, water chillers.
[0052] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel comprises an inflatable balloon open at one hermetically sealable end for enclosing said roots.
[0053] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel comprises an inflatable sleeve open at at least two hermetically sealable ends for enclosing around said roots such that at least a portion of said roots protrudes from beyond at least one said sleeve opening.
[0054] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel is adapted to be fitted to positively or negatively gravitropic aerial roots.
[0055] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel is adapted to be retrofitted to a crop, plant, shrub, bush, sapling or tree which is growing in a field.
[0056] It is an object of the present invention to disclose the aforementioned system wherein said pressure vessel is adapted to be fitted to a root of a scion or rootstock of a grafted plant.
[0057] In some embodiments all the root system may be enclosed, or single root branches, or parts of root branches.
[0058] It is an object of the present invention to disclose the aforementioned system wherein said PCS is adapted to enable salt water to recirculated and fresh nutrients added as required or according to a specific protocol.
[0059] It is an object of the present invention to disclose the aforementioned system wherein said salt water is provided under high pressure.
[0060] It is an object of the present invention to disclose the aforementioned system wherein several pressure vessels are networked in an integrated system controlled by a central controller.
[0061] It is an object of the present invention to disclose the aforementioned system wherein more than one fields or greenhouses or growing establishments are networked in an integrated system controlled by a central controller.
[0062] It is an object of the present invention to disclose the aforementioned system further comprising a central controller and a central server adapted to receive plant physiology, plant growth, plant health or other relevant agrotechnical or agricultural data from at least some plants fitted with said pressure vessels.
[0063] It is an object of the present invention to disclose the aforementioned system wherein said system is further provided with a processor for processing said plant physiology, plant growth, plant health or other relevant agrotechnical or agricultural data.
[0064] It is an object of the present invention to disclose the aforementioned system wherein said system is provided with a computer readable medium for providing instructions to the controller to adjust the pressure in the aforementioned pressure vessels in a predetermined manner.
[0065] It is an object of the present invention to provide the aforementioned method adapted to off-shore applications such as growing crops on a vessel, rig, raft, boat or other marine installation that moves on the ocean while pumping seawater.
[0066] The vessel, rig, raft, boat or other marine installation may move from one country to another or remain stationary and collect the abundant seawater.
[0067] The vessel, rig, raft, boat or other marine installation may cruise between one convenient location and head to the country market while growing the crops with the aforementioned method or system and harvest freshly upon arrival at the appropriate country market.
[0068] The above mentioned marine installation may be a moored, fixed floating vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments is adapted to now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which aspects of a pressurised cultivation system (PCS) for growing plants in high salinity are illustrated|:
[0070] FIG. 1 is a schematic illustration of an aspect of the present invention;
[0071] FIG. 2 is a schematic illustration of an aspect of the present invention;
[0072] FIG. 3 is a schematic illustration of an aspect of the present invention; and
[0073] FIG. 4 is a schematic illustration of an aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0074] The following description is provided, alongside all chapters of the present invention, so as to enable any person skilled in the art to make use of the aforesaid invention, and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, are adapted to remain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide means and methods for growing plants, by holding the plant roots under a high pressure environment so as to enable growth of plants in higher than normal salt conditions.
[0075] In general the present invention is directed to high value greenhouse crops such as Tomato Pepper Cucumber and horticultural flowers.
[0076] Embodiments of the invention are also suitable for orchards (such as apples, citrus, avocado, mango, and almond), fruit trees and viticulture, nut trees, tobacco and cotton.
[0077] In other embodiments of the present invention adaptations are made to support the growth of open-field crops among them field vegetables, orchards of all kinds and broad-acre crops like: wheat, maize, cotton, soy, tobacco and the like.
[0078] Definitions
[0079] It is herein stated that conventional state of the art knowledge and assumptions are drawn, without being bound by theory, from the book Plants in Action, Australian Society of Plant Scientists, New Zealand Society of Plant Biologists, and New Zealand Institute of Agricultural and Horticultural Science 1999, which is incorporated herein in it's entirety.
[0080] It is herein acknowledged that plants may also include, for he purposes of the present disclosure of the invention, plant parts, calluses, cells, tissue cultures, meristems, grafts, seeds, germinated seeds, seedlings and the like.
[0081] It is herein acknowledged that the term media is interchangeable with the term substrate.
[0082] Osmotic pressure is the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane. It is also defined as the minimum pressure needed to nullify osmosis.
[0083] The phenomenon of osmotic pressure arises from the tendency of a pure solvent to move through a semi-permeable membrane and into a solution containing a solute to which the membrane is impermeable. This process is of vital importance in biology as the cell's membrane is selective toward many of the solutes found in living organisms.
[0084] Osmotic potential is defined as the potential of water molecules to move from a hypotonic solution (more water, less solutes) to a hypertonic solution (less water, more solutes) across a semi permeable membrane.
[0085] Water potential is the defined as the degree to which a solvent tends to stay in a liquid.
[0086] Osmotic pressure is an important factor affecting cells. Osmoregulation is the homeostasis mechanism of an organism to reach balance in osmotic pressure.
Hypertonicity is the presence of a solution that causes cells to shrink. Hypotonicity is the presence of a solution that causes cells to swell. Isotonic is the presence of a solution that produces no change in cell volume.
[0090] When a biological cell is in a hypotonic environment, the cell interior accumulates water, water flows across the cell membrane into the cell, causing it to expand. In plant cells, the cell wall restricts the expansion, resulting in pressure on the cell wall from within called turgor pressure.
[0091] Osmotic pressure is the basis of filtering (“reverse osmosis”), a process commonly used to purify water. The water to be purified is placed in a chamber and put under an amount of pressure greater than the osmotic pressure exerted by the water and the solutes dissolved in it. Part of the chamber opens to a differentially permeable membrane that lets water molecules through, but not the solute particles. The osmotic pressure of ocean water is about 27 ATM. Reverse osmosis desalinates fresh water from ocean salt water.
[0092] Osmotic pressure is necessary for many plant functions. It is the resulting turgor pressure on the cell wall that allows herbaceous plants to stand upright, and how plants regulate the aperture of their stomata.
[0093] Potential osmotic pressure is the maximum osmotic pressure that could develop in a solution if it were separated from distilled water by a selectively permeable membrane. It is the number of solute particles in a unit volume of the solution that directly determines its potential osmotic pressure. If one waits for equilibrium, osmotic pressure reaches potential osmotic pressure.
[0094] Salinity and Crop Growth.
[0095] It is well known that soil salt and water salt restricts plant growth so that crop yield is reduced, but species differ in sensitivity. Four broad categories of salt tolerance were delineated by the USDA Soil Salinity Laboratory, Riverside, from a statistical analysis of an extensive survey of published data on yield and soil salinity (measured as electrical conductivity (ECE) of a saturated extract and expressed here as deciSiemens per metre (dS m-1)). Crops representative of each category are listed in Table 1. (Based on Maas and Hoffman 1977 as quoted in the above referenced Plants in Action ).
[0096] Salts dissolved in soil water inhibit plant growth because (1) salt reduces water uptake, and (2) excessive salt becomes toxic and causes further reductions in growth. To exist in a saline soil, plants must take up water but exclude salt.
[0097] Extensive research in California during the 1970s (USDA Salinity Laboratory, Riverside) provided baseline data on comparative salt tolerance for a wide range of crop plants. Statistical analysis of this far-ranging survey of crop plants showed that (1) yield did not generally decrease significantly until a salinity threshold had been exceeded, and (2) that yield generally decreased linearly with further increase in salinity. Some deviations from linearity occurred as relative crop yield dropped below 20-30%. The yield-salinity relationship becomes steeper, and threshold salinity decreases from ‘tolerant’ to ‘sensitive’ categories. Representative crops in each category highlight a number of horticultural species as sensitive or moderately sensitive, compared with cereals and coarse grains that are either moderately tolerant or tolerant.
[0098] For survey purposes, soil was regarded as saline if electrical conductivity of a saturated extract was more than 4-5 dS m-1, equivalent to about 40-50 mM NaCl, and sensitive plants such as lupin are greatly reduced at this level of salinity. By contrast, tolerant plants such as barley withstand 8 dS m-1 (equivalent to about 80 mM NaCl) while specialised halophytes grow under highly saline conditions, with NaCl concentrations reaching or even exceeding that of sea water, which is about 500 mM.
[0099] Table 1 shows the relative salt tolerance of selected crop plants from a broad survey by the USDA Salinity Laboratory, Riverside, corresponding to FIG. 17.2 of the above referenced Plants in Action .
[0000]
Moderately
Moderately
Sensitive
Sensitive
Tolerant
Tolerant
Almond
Broadbean
Beet
Barley
Apple
Cabbage
Broccolli
Bermuda Grass
Apricot
Capsicum
Bromegrass
Cotton
Avocado
Clover
Tall Fescue
Date
Bean
Cucumber
Olive
Sugarbeet
Carrot
Grape
Ryegrass, Perennial
Citrus
Lettuce
Safflower
Onion
Lucerne
Sorghum
Peach
Maize
Wheat
Plum
Peanut
Strawberry
Potato
Spinach
Sugarcane
Tomato
[0100] Table 1 above and Table 2 (Species of major crops, their families, use and region of origin From: Simmonds, N. W. 1976. Evolution of Crop Plants. Longman, London & New York) below provides a non-limiting list of plants, crops and families which, the generic principles of the present invention having been described herein, are all envisaged to be subject to the novel and inventive method described herein for growing plants, by holding the plant roots under a high pressure environment so as to enable growth of plants in higher than normal salt conditions. Other plants are also contemplated to be amenable to be grown with the herein described means and methods.
[0000]
AGAVACEAE
Agave
Sisal and relatives
Central
Fibre
America &
Mexico
AMARANTHACEAE
Amaranthus spp
Grain amaranths
The Americas
Grain
ANACARDIACEAE
Mangifera indica
Mango
India
Fruit (tree)
ARACEAE
Alocasia, Colocasia ,
Edible aroids: taro,
Asia; S.
Cyrtosperma, Xanthosoma
eddo, dasheen,
America
tanier, yautia,
cocoyam
Corms & leaves
BOMBACACEAE
Ceiba pentandra
Kapok
American &/or
Fibre from fruit
Africa
(tree)
BROMELIACEAE
Ananas comosus
Pineapple
S. America
Fruit
CAMELLIACEAE
Camelia sinensis
Tea
SE Asia
CARICACEAE
Carica papya
Papaya
Tropical
Fruit
America
CHENOPODIACEAE
Beta vulgaris
Sugar beet
Europe
Sugar (from root)
Chenopodium spp
Quinoa and relative
C.& S.
Grain
America
COMPOSITAE
Carthamus tinctorius
Safflower
Near East
Oilseed
Chrysanthemum spp
Pyrethrum
Asia & Europe
Insecticide
Helianthus annus
Sunflower
USA
Helianthus tuberosus
Oil Jerusalem
artichoke
Tubers
Lactuca sativa
Lettuce
Old World
Leaves
CONVOLVULACEAE
Ipomea batatas
Sweet potato
Mexico, C. or
Tubers
S. America
CRUCIFEREAE
Brassica campestris
Turnip & relatives
Mediterranian
Storage organs,
& Afghanistan,
leaves, seeds (for oil)
Pakistan
Brassica oleracea
Cabbages, kales etc.
Mediterranian
Leaves, buds, stems,
&/or Asia
influorescence
Minor
Brassica napus
Swedes and rapes
Europe or
Forage; oilseed
Mediterranian
Brassica spp and
Mustards
Mediterranean
Sinapis alba
Spice, oil seed,
leaves
Raphanus sativus
Radish
Some area east
Roots; leaves, seeds
of
Mediterranian
Rrippa nasturtium -
Watercress
Europe
aquaticum
Leaves
CUCURBITACEAE
Cucumis, sativus Cucumis
Cucurbits:
India Africa,
mela Citrullus, lanatus
Cucumber
India S. Africa
Cucrbita spp Lagenaria
Musk melon
Americas
niceraria
watremellon
Africa
squashes, pumpkins
wh-flowered gourd
DIOSCOREACEAE
Dioscorea spp
Yams
Asia Africa,
roots
tropical
America
EUPHORBIACEAE
Aleurites spp
Tung
China
Oil for paints,
varnishes
Hevea brasiliensis
Rubber
S. America
Manihot esculenta
Cassava
Tropical
Roots
America
Ricinus communis
Castor
Africa
Oil for industry;
medicinal
GRAMINEAE
Avena spp
Oats
Near East
Grain, straw
Eleusine coracana
Finger millet Bulrush
Africa
Pennisetum americanum
millet
grain
Hordeum vulgare
Barley
Near East
grain
Oryza sativa O. glaberrima
Asian Rice African
Asia Africa
Rice
grain
Saccharum spp
Sugarcanes
New Guinea
Stems for sugar
Secal cereale
Rye
Near East
Grain, straw, forage
Sorghum bicolor
Sorghum
Africa
Sudan grasses
Grain, straw, forages
Tritisecale spp
Triticale
Modern
Grain
intergeneric
hybrid of wheat
and rye
Triticum spp
Wheat
Near East
grain
Zea mays
Maize, corn
Americas
Grain, forage
Lolium, festuca, Dactylis ,
Tmeperate herbage
Europe
Phleum, Bromus
grasses
Panicum, Pennisetum ,
Tropical grasses
Africa
Cynodon
Herbage
GROSSULARIACEAE
Ribes spp
Curants
Europe
LAURACEAE
Persea americana
Avocado Fruit
C. America
LEGUMINOSEAE
Arachis hypogaea
Groundnut (peanut)
S. America
Cajanus cajan
Pigeon pea Grain
India?
Cicere arietunum
Chickpea Grain
W. Asia
Glycine max
Soybean Grain; oil
China
Lens culinaris
Lentil Grain
Near East
Medicago sativa
Alfalfa Forage
Near East
Phaseoulus spp
Beans
Middle & S.
America
Pisum sativum
Peas Grain
Ethiopia or
Mediterranian
or C. Asia
Trifolium spp
Clovers Forages
Eastern
Mediterranian
Vicia faba
Field bean Grain
Near east
Vigna unguiculata
Cowpeas Grain,
Africa
Vegetable, fodder
LILIACEAE
Allium
Onion and allies
Central
Vegetables
Asia/Near East
LINACEAE
Linum usitatissimum
Flax and Linseed Oil
?India
and fibre
MALVACEAE
Abelmoschus esculentus
Okra Fruits (as
Africa
vegetable)
Gossypium spp
Cotton Hairs on
Tropical
seeds
America,
Asiua, Africa
MORACEAE
Artocarpus spp
Breadfruit and
Malaysia
relatives Fruit
Cannabis sativa
Hemp Fibre; oilseed
Temperate Asia
Ficus carica
Fig
Southern
Arabia
Humulus lupulus
Hops Brewing
Europe
MUSACEAE
Musa spp
Bananas
Malaysia
MYRTACEAE
Eugenia caryophyllus
Clove Oil, spice
Indonesia
OLEACEAE
Olea europaea
Olive Oil
Near East
PALMAE
Cocos nucifera
Cocount
Southeast Asia
Elaeis guineeensis
Oil palm Oil
Africa
Phoenix dactylifera
Date palm fruit
N. Africa
PEDALIACEAE
Sesamum indicum
Sesame Oilseed
?Ethiopia or
India
PIPERACEAE
Piper nigrum
Black pepper
India
POLYGONACEAE
Fagopyrum
Buckwheat Grain
Temperate
eastern Asia
ROSACEAE
Fragaria ananassa
Strawberry Fruit
Europe, N & S.
America
Prunus spp
Cherry, plum, peach,
C. Asia, China,
Apricot, almond
N. America
Fruit
Malus & Pyrus spp
Apple and Pear
Asia Minor, C.
Asia
Rubus spp
Raspberries and
Europe, N.
blackberries
America
RUBIACEAE
Cinchona spp
Quinine Drug
Andes
Coffea spp
Coffee Seeds
Ethiopia
RURACEAE
Citrus spp
Citrus fruits
India
SOLANACEAE
Capsicum spp
Peppers
C. & S.
America
Lycoperscion esculentum
Tomato
S. America
Nicotinia tabacum
Tobacco Leaves
Americas
Solanum tuberosum
Potatoes Tubers
Bolivia-Peru
STERCULIACEAE
Cola spp
Kola nuts (tree)
Africa
Seeds
Theobroma cacao
Cacao Seeds from
S. America
fruit
TILIACEAE
Corchorus spp
Jute Fibre
India
UMBELLIFERAE
Daucus carota
Carrot Root
Europe
VITACEAE
Vitis Muscadinia
Grapes
Middle Asia
[0101] In some embodiments of he present invention the whole root system is inserted into and maintained under pressurized conditions, and in other embodiments only part of the root system is inserted into and maintained under into pressurized conditions. In some embodiments all the root system may be enclosed, or single root branches, or parts of root branches.
[0102] FIG. 1 is now referred to: Soil salt restricts plant growth so that crop yield is reduced, but species differ in sensitivity. These four broad categories of salt tolerance were delineated by the USDA Soil Salinity Laboratory, Riverside, from a statistical analysis of an extensive survey of published data on yield and soil salinity (measured as electrical conductivity (ECE) of a saturated extract and expressed here as deciSiemens per meter (dS m −1 )). Crops representative of each category are listed in Table 17.3. (Based on Maas and Hoffman 1977)
[0103] Salts dissolved in soil water inhibit plant growth because (1) salt reduces water uptake, and (2) excessive salt becomes toxic and causes further reductions in growth. To exist in a saline soil, plants must take up water but exclude salt. The present invention provides a system for enclosing the roots or rhizosphere of the plant under high pneumatic pressure, so as to enable the plant to grow under higher than normal saline conditions. The present invention provides means and methods for increasing the salt exclusion properties of the roots in a given species.
[0104] Reference is now made to FIG. 2 which is a schematic representation of an exemplary embodiment, of the present invention, namely a pressurised cultivation system (PCS) for growing plants in high salinity. The aforementioned system comprises a pressurised container or vessel 240 partially filled with liquid for hydroponic growth and air, with an airtight sealable upper portion in which the plant is rooted, and a portion of the growing plant 240 a is exposed to the air. A source of salt water and nutrients 220 is provided which is pumped into the container by a pump unit 210 . A high pressure production (compressor) and regulator unit 230 provides a high pressure environment 240 b in the pressurised container or vessel. Salty water is injected into the system by the pump, creating pressure which is higher than the maintained pressure provided by the compressor 230 , thereby creating a pressurized environment. In such a case the pressurised environment is the result of the high pressure injection of salt water and the work done by the compressor. In some embodiments of the present invention, the salty water may be at a higher altitude than the pressurised vessels and thus the salty water supply contributes to the pressurisation by way pressure difference between a high location and a low location. Such an arrangement will be energy saving. A high pressure production and regulator unit 230 provides a high pressure environment 240 b in the pressurised container or vessel. In some embodiments of the system a valve 290 regulates the outflow of spent salt water through the system. The spent salt water may be collected in a container 250 for further use, disposal or processing. Water pipes 260 , 270 , 280 connect the components of the system.
[0105] Reference is now made to FIG. 3 which is a schematic representation of an exemplary embodiment, of the present invention, namely a pressurised cultivation system (PCS) for growing plants in high salinity. The aforementioned system comprises a pressurised container or vessel 330 partially filled with liquid for hydroponic growth and air, with an airtight sealable upper portion in which the plant is rooted, and a portion of the growing plant 330 a is exposed to the air. A source of salt water and nutrients 310 is provided. In some embodiments of the present invention valves 380 are provided for regulating flow from the aforementioned source. A high pressure production and regulator unit 320 provides a high pressure environment 330 b in the pressurised container or vessel. In some embodiments of the system a valve 390 regulates the outflow of spent salt water through the system.
[0106] The spent salt water may be collected in a container 340 for further use, disposal or processing.
[0107] Water pipes 350 , 360 , 370 connect the components of the system.
[0108] It is herein acknowledged that in some embodiments of the invention, the pressure vessels are inflatable balloon like structures sealable around the plant root at at least one, or in other cases, two openings.
[0109] In some embodiments of the present invention, where it is topographically suitable, high pressure injection of salt water is not needed, but rather the pressure difference due to altitude is used.
[0110] In some embodiments of the invention the pressurised vessel provides a definition sealed environment which may be a sealed plastic box, balloon or any other structure made of a material that can withstand the pressurized conditions and support a sealed environment.
[0111] Reference is now made to FIG. 4 , which schematically illustrates aspects of some embodiments of the present invention.
[0112] The plant 410 is rooted in a media or substrate 420 . The root system 460 may wholly or partially be enclosed in a pressure vessel of the invention. In a non limiting example, a pressurised vessel 430 encloses the lower end of one branch of the root system or rhizosphere, another vessel 440 encloses another branch, and another pressurised vessel 450 encloses part of the root branch. Note that pressurised vessel 450 is sleeve-like and has two sealable openings.
[0113] In some embodiments of the present invention the whole root system is inserted into and maintained under pressurized conditions, and in other embodiments only part of the root system is inserted into the pressure vessel and maintained under pressurized conditions.
[0114] In some embodiments of the present invention the system is so arranged as to utilize the atmospheric pressure differences between high mountain and low valley in topographically suitable areas.
[0115] In some embodiments of the invention the system excess water is collected by drainage and is utilised for other uses or returned back to its source (for example in the case of seawater).
[0116] In some embodiments of the invention the salt water is recirculated and fresh nutrients are added.
[0117] In some embodiments of the system the salt water is provided under high pressure.
[0118] In some embodiments of the present invention several pressure vessels are networked in an integrated system controlled by a central controller.
[0119] In some embodiments of the present invention several fields or greenhouses or growing establishments are networked in an integrated system controlled by a central controller.
[0120] In some embodiments of the invention a central controller is provided on a centralised server which receives plant physiology, plant growth, plant health or other relevant agrotechnical or agricultural data from at least some plants fitted with the above mentioned pressure vessels. The plant data is monitored and processed. The central controller is provided with a computer readable medium which provides instructions to the controller to adjust the pressure in the aforementioned pressure vessels accordingly.
[0121] In some embodiments of the invention the controller and server may be on the same device.
[0122] In other embodiments of the invention the controller and the server are separate. In other embodiments of the invention the server may reside on site/farm or at a remote location.
[0123] Some embodiments of the present invention will provide the aforementioned method adapted to off-shore applications such as growing on a vessel, rig, raft, boat or other marine installation that moves on the ocean while pumping seawater.
[0124] The vessel, rig, raft, boat or other marine installation may move from one country to another or remain stationary and collect the abundant seawater.
[0125] The vessel, rig, raft, boat or other marine installation may cruise between one convenient location and head to the country market while growing the crops with the aforementioned method or system and harvest freshly upon arrival at the appropriate country market.
EXAMPLE
[0126] A citrus plant, bitter orange, C.×aurantium was used in this experiment. The roots of these plants can develop a maximum osmotic pressure of 15 ATM under normal conditions.
[0127] Sea water of Osmotic pressure equivalent to 28 ATM ws used, mixed with sweet water 60%:40% to achieve an osmotic pressure of 16.8 ATM.
[0128] Method
[0129] Plants were placed in rows with 3 plants in each row. Each row was provided with the same water mixture (WM) of 16.8% osmotic pressure.
[0130] The control row was plants open to the air, under normal temperature and pressure. The experimental row was plants with their roots held under 4ATM pressure in pipes, and the WM was provided by a compressor pump.
[0131] Preparation
[0132] 15-22 Oct. 2010, sweet water was provided atv 0.8 ATM.
[0133] 22-29 Oct. 2010, 50% sea water was provided at 5 ATM.
[0134] 22-29 Oct. 2010, 50% sea water was provided at 5 ATM.
[0135] 29 October-5 November 50% sea water was provided at normal pressure.
[0136] From 5 th November 50% seawater was provide at 4.2 ATM.
[0137] Trial
[0138] The trial lasted from 5 th November to 19 th December at which time the plants were inspected.
[0139] Control group:
Plant no 1 was dead, with dry roots. Plant no. 2 was infected with fungus and weeds and appeared to have been badly affected by them. Plant no 3 had highly necrotic leaves.
[0143] Experimental group:
Plant no 1 was in poor condition. Plant no 2 was in good condition. Plant no 3 was in good condition.
[0147] The trial was continued until 12.02.2011 in the following manner: Surviving experimental plants were grown in pressure vessels under 4 ATM as previously described.
[0148] Table 2 show the results below:
[0000]
A
B
C
D
E
21 Jan. 2011
Severe
Green
Green
Green
Green
Necrosis
leaves
leaves
leaves
leaves
28 Jan. 2011
Did not
Green
Green
Green
Green
survive
leaves
leaves
leaves
leaves
05 Feb. 2011
Did not
Green
Green
Green
Green
survive
leaves
leaves
leaves
leaves
12 Feb. 2011
Did not
Green
Slight
Green
Severe
survive
leaves
Necrosis
Leaves
Necrosis
[0149] Conclusions
[0150] Growth of the above plants under higher than normal saline conditions is facilitated by placing the roots or rhizosphere under an osmotic pressure of approximately 4 ATM.
[0151] The pressurised cultivation system (PCS) can be adapted and modified to grow plants in higher salinity than normal.
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A method of growing plants in high salinity is hereby presented. The method comprises steps of obtaining a pressurised cultivation system (PCS) having a pressure vessel for growing at least one plant on a media or substrate, the pressure vessel housing at least the roots of said at least one plant, a source of saline water and a high pneumatic pressure production unit operatively connected to said pressure vessel for providing higher than ambient pressure to said pressure vessel, thereby maintaining said roots of said at least one plant under high pressure during growth, planting a plant in the pressure vessel such that at least a portion of said roots are hermetically sealed within said pressure vessel, providing saline or brackish water to said media and pressurising said vessel. Systems and devices for the above are described.
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TECHNICAL FIELD
This invention relates to plate type heat exchangers in general, and specifically to a method for producing a plate type automotive air conditioning evaporator and core in which the refrigerant feed pipe end points are sufficiently supported on the core to allow the evaporator and core to be brazed together in one step, with the feed pipes in place.
BACKGROUND OF THE INVENTION
Evaporator cores used in automotive air conditioning systems are typically of a plate type, parallel flow construction, a typical example of which is illustrated in FIG. 1 at 10. A stacked series of shallow, wide, stamped aluminum alloy plates 12 are stacked together in face to face abutment and brazed together in a heated braze oven. When the edges of each abutted pair of plates 12 fuse together they form a series of wide, thin flow passages. An integral stamped cup 14 (or pair of cups) at the end of each plate 12 align end to end to form a pair of manifold tanks that distribute refrigerant to the flow passages. Corrugated cooling fins 16 are brazed between the fused pairs of plates 12. The cups 14 and the tanks they form may be at opposite sides of the core or side by side in the so called U flow type of evaporator core, which is increasingly common, and which is the type shown in FIG. 1. Typically, the plates 12 are identical, except the two endmost plates, which can be simple flat plates without the other stamped in features, such as bump patterns and divider ribs, that the main plates have.
Plate type evaporator cores of either type must have refrigerant fed at discrete points into and out of their manifold tanks by feed pipes, often called inlet and outlet pipes. These feed pipes may enter the manifold tanks at the ends, passing through the endmost plates. More and more designs are being proposed for so called "face plumbing", in which the feed pipes enter the manifold tanks at any desired point along the length of the tanks, generally by "plugging into" and replacing the dram cups 14 at selected points. An example may be seen in U.S. Pat. No. 4,821,531 issued Apr. 18, 1989 to Yamauchi et al. Or, a face plumbed type feed pipe may "plug in" only just inside the end plates, as in U.S. Pat. No. 4,487,038 issued Dec. 11, 1984 to Iijima. However, the term "pipe" is used rather loosely throughout various existing patents, sometimes to refer to a very short stub pipe, as in the Iijima reference. As a practical matter, such a short "pipe" is really no more than a stub fitting to which the inner end of a longer feed pipe is fixed later, generally by separate welding, after the main core brazing process is completed. Such long feed pipes are shown in FIG. 1, including an inlet pipe I and outlet pipe 0. Each feed pipe has a remote, threaded attachment end point 18, 20, to which refrigerant lines would be attached when the air conditioning system was installed. Proper location in space of the end points 18 and 20, relative to the core 10, is critical to final installation success.
In cases where the feed pipes are very short and located close together, as in U.S. Pat. No. 4,867,486 issued Sep. 19, 1989 to Fukata et al, it is possible to braze the feed pipes into the core directly. However, the process proposed still requires the use on separate support clips in the braze oven, which are later removed, in order to hold the pipes in place. Even then, the feed pipes must be short and located side by side, with adjacent attachment end points that are still subject to tilting off axis during the brazing process. There is no known, practical process for brazing long, meandering feed pipes with remote end points integrally to the core. This is because the brazing process would cause the feed pipes to sag and lose their original shape, moving the end points out of their proper, final build position.
SUMMARY OF THE INVENTION
The invention provides a practical process for brazing long feed pipes with remote attachment end points integrally to a stacked, plate type evaporator core. The end points are integrally fixtured and supported on the core without the need for additional basic components.
In the embodiment disclosed, the core designer determines the desired final locations for the attachment end points of the feed pipes. Then, those core plates (or plate) closest to the final end point locations are determined. Then, the selected plate or plates are replaced with support plates that are stamped with an integral, upstanding support flange. The flange corresponds as closely as possible to the desired final end point location of the feed pipe or pipes. In the embodiment disclosed, a slot (with an adjacent supporting shelf) is formed in the flange to support the feed pipe at a point near the threaded end point. The supporting shelf is also clad with a layer of braze material, since the base plate itself is clad. When the feed pipes are assembled to the core, the feed pipe end points rest on the flanges, held in their proper location. During the brazing process, although the unsupported length of the feed pipe may sag or wander, the attachment end points are solidly held in their proper position. When the core cools, the feed pipe end points are also fused to the flanges, protected against damage during shipping and handling, prior to final installation of the evaporator core.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will appear from the following written description, and from the drawings, in which:
FIG. 1 is a face on view of a prior art evaporator described above;
FIG. 2 is a perspective view of two pairs of stamped plates and one corrugated fin that make up the core of the invention;
FIG. 3 is a perspective schematic view of one possible core and feed pipe configuration made according to the invention;
FIG. 4 is a view like FIG. 3 showing another possible configuration;
FIG. 5 shows yet another possible configuration; and
FIG. 6 is a schematic view showing a possible scheme for efficient stamping of those plates that have the integral support flanges.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 2 and 6, an evaporator core made according to the invention is indicated generally at 22. Core 22, as is typical, is comprised of a laminated stack of essentially identical stamped plates, three of which are indicated at 24. The plates 24 are basically the same as the plates 12 described above. Each plate 24 would be stamped from a suitable aluminum alloy in the 3000 series, approximately fifteen to twenty thousandths of an inch thick, and clad on both sides with a conventional aluminum-silicon alloy braze layer. The plates 24 are brazed in abutted pairs, and conventional corrugated like the fins 16 described above are brazed in the space between the plate pairs. Refrigerant flows through the generally U shaped flow passages formed by the fused pairs of plates 24, as indicated by the arrows. One or more of the plates differ, however, one of which is indicated generally at 26. Plate 26 is formed of the same material and has all the same features as any of the other plates 24 but has an additional, though integral, structural feature. This is a feed pipe support flange 28, which is a rectangular extension of the side edge of the plate 26, coplanar thereto, located and sized according to considerations detailed below. Folded integrally out of the flange 28 are a pair of generally rectangular support shelves 30, each of which is substantially perpendicular to the coplanar plate 26 and flange 28. Each shelf 30 is the residue of an adjacent a corresponding notch 32. Since both surfaces of the aluminum alloy stock from which all of the plates 24 and 26 are stamped is clad with a layer of braze material, so are the surfaces of the support shelves 30. As seen in FIG. 6, the support plates 26, being significantly wider, would have to be stamped separately from the main plates 24. However, they could be twinned and stamped out of a single blank indicated at 34, thereby efficiently utilizing material. The main body of the support plates 26 would be stamped identically to the main plates 24, however, with only the support flange 28 differing. The considerations that would go into the location, shape and size of the support flange 26 and flange 28 are described next.
Referring next to FIG. 3, one possible configuration of an evaporator incorporating the basic core design 22 is indicated generally at 36. Evaporator 36 consists of the core 22 and a pair of refrigerant feed pipes 38 and 40, one of which would be an inlet, and the other an outlet. Each feed pipe has a threaded attachment end point 42 and 44 respectively, to which a non illustrated refrigerant line would be attached when the air conditioning system was installed. The feed lines 38 and 40 are shown as "end plumbed," that is, feeding refrigerant into and out of the ends of the core 22, rather than into the "face" of the core 22. What is significant, however, is not the attachment of the feed pipes to the core 22, either the means or location. What is significant is the remote locations that the end points 42 and 44 must have in order to be successfully installed to the refrigerant lines. These final assembly points may vary from car line to car line, and are very often remote from one another, as well as from the points where the feed pipes 38 and 40 themselves attach to the core 22. This requires long lengths of unsupported pipe in between. One such possible configuration of the feed pipes 38 and 40, chosen for illustration, puts the end points 42 and 44 near together, but crossing 90 degrees apart, near one corner of core 22. In any particular case, the general location and direction of the refrigerant supply lines will be predetermined by other factors in the design of the vehicle and body, and the designer of the particular evaporator must take them as a given.
What the designer of core 22 would do would be to determine, given the installation location of core 22 in the vehicle (also a given), approximately where the end points 42 and 44 should be located relative to the core 22 in order to assure installation compatibility with the predetermined refrigerant supply lines' location. Then, the location of the plate or plates 24 closest to the approximate end point locations would be determined. That particular plate (or plates) 24 would be chosen for replacement by a support plate 26. The flange 28 on support plate 26, in turn, would be sized and located so that the support shelves 30 were at the proper level to hold the pipes 38 and 40, coinciding as closely as possible to the final locations of the respective attachment end points 42 and 44. For the embodiment shown in FIG. 3, one support plate 26 only with one flange 28 only is sufficient. To assemble evaporator 36, core 22 would be stacked and bundled as usual, with the addition of support plate 26 in place of the selected plate 24 being the only difference. In some cases, automatic stacking and bundling equipment might have to be altered somewhat to accommodate the support plate 26 with its protruding flange 28. Then, the feed pipes 38 and 40 would be inserted into the core 22, either into fittings provided for that insertion, or directly. If fittings were provided for the insertion of the pipes 38 and 40 into the core 22, the would not have to be designed to allow for the later welding in of the feed pipes 38 and 40, since they are brazed simultaneously with the core 22 itself. When the feed pipes 38 and 40 are inserted into core 22, their attachment end points 42 and 44 are rested near the support shelves 30, near enough that very little unsupported length of pipe protrudes beyond. The fit of the pipes 38 and 40 within the notches 32 can be made snug enough to pinch the pipes 38 and 40 and hold them temporarily in place if desired. Finally, the stacked and bundled core 22, with pipes 38 and 40, is placed in a braze oven in the orientation shown, with the pipes 38 and 40 resting on the upwardly facing surfaces of the support shelves 30. During the braze process, the heat may cause the unsupported length of the pipes 38 and 40 to sag. This, however, is irrelevant so long as the location of the end points 42 and 44 are assured. The flanges 28 are short and stiff enough to be rigid and to so assure the proper endpoint locations, in combination with the short shelves 30. The flanges 28 are nearly as resistant to deformation in the braze oven as the plates 24 themselves, of course. Besides the support provided during the braze process, when the heated core 22 and pipes 38 and 40 are allowed to cool, the pipes 38 and 40 actually fuse to the flange support shelves 30 near the end points 42 and 44, providing additional support and good protection against damage and dislodging during shipping and handling. Furthermore, during installation of the air conditioning system, the solid support of the end points 42 and 44 would assist in threading on the refrigerant supply lines.
Referring next to FIG. 4, another possible evaporator configuration built off of the same core 22, and even using the same pipe support plate 26, is indicated generally at 46. Here, one of the feed pipes, 40 is the same as in the FIG. 3 configuration, and its attachment end point 42 is identically located. The other feed pipe 48 is bent around in the other direction, however, and runs though the upper notch 32 and across the upper support shelf 30 in the opposite direction. Its attachment end point 50 is similarly supported, but in a new location, by the same basic structure.
FIG. 5 shows yet another evaporator 52 designed by the same process. Here, the same basic core 22 is also used, but the feed pipes 54 and 56 are both plumbed into the face of the core 22, and run toward the same end of core 22, terminating at respective attachment end points 58 and 60 located near the end of core 22. Therefore, the pipe support plate differs accordingly, both as to location within the core 22, and as to location of the support flange on the support plate. Specifically, the support plate 62 constitutes the end or side plate of core 22 and, as a consequence, might be stamped of a thicker material, without the bump pattern and divider ribs that characterize the central plates 24. The support flange 64 is similar to support flange 28, but located closer to the upper edge of the core 22. It includes the same kinds of notches 66 and support shelves 68. It will be noted that the feed pipes 54 and 56 are illustrated as being highly curved along their length, which could be, in any particular case, the result of pre bending so as to clear other components within the vehicle, or a result of sagging in the braze oven.
An almost unlimited number of configurations could be provided under the same basic design principals. If the feed pipes terminated at widely divergent locations, more than one support plate, or even one support plate with two widely spaced support flanges, could be used. A support flange with only one notch and shelf could be used to support a single feed pipe attachment end points, in a case where the end points were not proximate. A notch opening upwardly, rather than to the side, could be used, with or without a support shelf. Since the support shelves can be folded out simply as the residue of the notches, they are an essentially cost free means of providing extra support, however. Or, the support flanges could support the feed pipe ends on thin protruding tabs, rather than notches and shelves. Even a pipe support surface that was not clad with braze material, and did not actually fuse to the feed pipe, would provide solid support for the attachment end point during brazing. Since the plate stock invariably will be clad both sides with braze material, the fusion to the feed pipe and extra support provided thereby is another essentially cost free advantage. In every case, the elimination of the necessity of providing a separate, post braze step of welding the feed pipes to the evaporator core, or of providing separate clips on the core, is a very significant labor and cost savings. Therefore, it will be understood that it is not intended to limit the invention to just the embodiments disclosed.
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A plate type evaporator core can be brazed in one step, even with long refrigerant feed pipes in place, and without the need for separate support fixtures or clips. This is done by stamping selected ones of the stamped plates that make up the core with integral feed pipe support flanges, located so as to coincide spatially with the desired final locations of the attachment end point of the feed pipes. The end points are supported on the flanges in the braze oven, and maintained in their proper locations regardless of any heat sagging of the rest of the feed pipe along its length.
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RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. Section 119 to U.S. Provisional Application No. 62/369,737, filed Aug. 1, 2016, entitled “DOOR CLOSER”, the contents of which are incorporated herein by reference in their entirety.
BACKGROUND
Technical Field
[0002] The present invention relates to door closers, more particularly, to hydraulic door closers whose opening cycle and closing cycle is controlled by the movement of hydraulic fluid within the door closer.
Background of the Invention
[0003] Hydraulic overhead concealed door closers typically include a spindle that extends below the closer housing to connect to the door as well as a cap on the bottom of the closer housing that faces the door. In such prior designs, the spindle extends through the cap. Unfortunately, such caps are often not effective in preventing hydraulic fluid within the door closer from leaking, which is aided by gravity.
[0004] Fluid may also leak around the exterior of the spindle due to the fact that spindles may not have an entirely smooth exterior surface.
[0005] In prior designs, one or more adjustment valves are usually present. The adjustment valves control the flow of hydraulic fluid through the door closer. Without sealing around the valves, the valves are prone to leakage of hydraulic fluid.
[0006] Moreover, in prior designs, the end caps are typically comprised of aluminum whereas the closer housing is typically comprised of a different material (namely, steel) and the use of different materials can lead to leakage.
[0007] Finally, backcheck is feature on some door closers that prevents the door from crashing into the wall when it is opened suddenly. However, existing backcheck designs on the market use a fixed spring instead of an adjustable spring so that the strength of the spring force in the existing designs cannot be adjusted by the user.
[0008] Therefore, there is a need for new door closers that are less prone to leakage. There is also a need for new door closers with backcheck that also include an adjustable spring.
BRIEF SUMMARY
[0009] The present disclosure provides a door closer that is less prone to leaking and/or includes backcheck with an adjustable spring as described herein.
[0010] In some embodiments, the door closer includes one or more features that may resist leakage of hydraulic fluid: 1) the top cap is opposite the spindle and is on top of the housing so that gravity does not cause fluid to leak through the cap; 2) epoxy and an O-ring at the interface between the top cap and the housing of the door closer; 3) use of a rubber seal around the spindle, which may be in the form of a circular piece of rubbex with an inner wall and outer wall and the rubber seal may compress the inner wall against the spindle to create a seal, and the seal may be comprised of metallocene butadiene rubber; 4) use of dual O-rings on each valve stems, namely, adjustment valves that include—three ridges/lip, a bottom ridge, a middle ridge, and a top ridge and an O-ring is between the bottom ridge and the middle ridge and a different O-ring is between the middle and between the top ridge; and/or 5) use of caps that are made of steel (the same material as the housing) instead of aluminum and use of epoxy on the end caps. The present disclosure also provides use of backcheck with an adjustable spring. The aforementioned is intended to provide a brief summary of some of the features of the present disclosure and is not intended to limit the present disclosure.
[0011] In some embodiments, the present overhead concealed door closer system comprising: a) a door frame defining a door opening, the door frame comprising a door frame width and a door frame top located above the door opening; b) a door comprising a door top and a door width, the door configured to pivot from a closed position in which the door covers the door opening, the door width is substantially parallel to the door frame width and the door top faces the door frame top, to an open position in which the door does not cover the door opening and in which the door width is not substantially parallel to the door frame width; c) a hydraulic overhead concealed door closer located in the door frame top and comprising: i) a housing comprising an interior, a top side, a bottom side opposite the top side and facing the door top when the door is in the closed position, a housing height extending from the housing top side to the housing bottom side and generally perpendicular to the door frame width and the door width, a front side, a rear side, a housing thickness extending from the housing front side to the housing rear side and generally perpendicular to the housing height and generally perpendicular to the door width when the door is in the closed position, a proximal end, a distal end, a housing width extending from the housing proximal end to the housing distal end and generally perpendicular to the housing height and the housing thickness and generally parallel to the door width when the door is in the closed position; a cylinder located in the housing interior, the cylinder having a cylinder length generally parallel to the housing width; a moveable piston located in the cylinder and configured to move at least partially along the cylinder length, the moveable piston dividing the housing interior into a proximal chamber and a distal chamber; iv) hydraulic fluid located in the proximal chamber and the distal chamber; v) at least one channel located in the housing interior and configured to transport hydraulic fluid between the proximal and distal chambers, the at least one channel having a channel length generally parallel to the housing width and the cylinder length; vi) a cam assembly comprising a spindle, the spindle having a spindle height generally parallel to the housing height and a spindle perimeter generally perpendicular to the spindle height, the spindle extending below the housing bottom side, the spindle configured to rotate about a spindle rotational axis generally parallel to the spindle height (rotate means at least partially rotate); vii) an arm attached to the spindle and to the door top; and viii) a top cap having a top cap diameter generally perpendicular to the housing height and sealing the distal chamber from the door frame, the top cap located at the top side of the housing and opposite to the spindle (more particularly opposite the tip of the spindle that extends below the bottom side of the housing). Optionally, pivoting the door from the closed position to the open position is configured to cause the spindle to rotate (i.e., partially rotate) about the spindle rotational axis and cause the piston to move within the cylinder at least partially along the cylinder length. Optionally, the spindle does not extend through the top cap. Optionally, the system further comprises a spindle seal, the spindle seal surrounding and compressing against the perimeter of the spindle and located below the top cap. Optionally, the spindle seal comprises a diameter generally perpendicular to the housing height. Optionally, the system further comprises a bottom bearing located between the spindle seal and the cam assembly, the bottom bearing comprising a diameter generally perpendicular to the housing height. Optionally, the top cap further comprises a top cap circumference and further wherein the system further comprises an O-ring surrounding the top cap circumference. Optionally, the top cap is attached to the housing via epoxy and threading. Optionally, the top cap and the housing are comprised of the same material. Optionally, the system further comprises at least one valve controlling the flow of the hydraulic fluid within the at least one channel, the at least one valve comprising a valve stem having a valve stem height generally parallel to the housing height and further wherein the valve stem comprises a top ridge (comprising a top ridge diameter perpendicular to the housing height), a middle ridge located below the top ridge (and comprising a middle diameter generally perpendicular to the housing height), and a lower ridge located below the top ridge and the middle ridge (and comprising a lower ridge diameter generally perpendicular to the housing height), a top O-ring located between the top ridge (and comprising a top O-ring diameter generally perpendicular to the housing height) and the middle ridge and compressing against the valve stem and a lower O-ring located between the middle ridge and the lower ridge and compressing against the valve stem (and comprising a lower O-ring diameter generally perpendicular to the housing height). Optionally, the system further comprises at least one end cap located on the proximal end of the housing, the end cap comprising an end cap diameter generally perpendicular to the housing width, at least one spring located distally relative to the end cap and the piston, the spring comprising a proximal end attached to the piston and a distal end, the spring having a relaxed position and a compressed position, and further wherein moving the door from the closed position to the open position is configured to cause the door arm to cause the spindle to rotate about the spindle rotation axis and cause the spring to move from the relaxed position to the compressed position and the piston to move distally (and the in the general direction of toward the spindle) within the cylinder. Optionally, the end cap is configured to seal the hydraulic fluid within the proximal chamber and the housing and the end cap are comprised of the same material. Optionally, the end cap further comprises a circumference and further wherein the system further comprises an O-ring, the O-ring surrounding and compressing against the end cap circumference. Optionally, pivoting the door from the closed position to the open position is configured to cause the piston to move distally (and generally towards the spindle) and move hydraulic fluid located distal to the piston distally within the cylinder. Optionally, moving the piston distally within the cylinder is configured to cause hydraulic fluid to move from the distal chamber through the at least one channel and into the proximal chamber. Optionally, pivoting the door from the open position to the closed position is configured to cause the piston to move proximally (and generally away from the spindle) and move hydraulic fluid located proximal to the piston proximally within the cylinder. Optionally, moving the piston proximally within the cylinder is configured to cause hydraulic fluid to move from the proximal chamber through the at least one channel and into the distal chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a front perspective view of a hydraulic door closer of one embodiment of the present invention.
[0013] FIG. 2 illustrates a front exploded perspective view of the hydraulic door closer of FIG. 1 .
[0014] FIG. 3 illustrates a bottom perspective view of the hydraulic door closer of FIG. 1 .
[0015] FIG. 4 illustrates a bottom exploded perspective view of the hydraulic door closer of FIG. 1 .
[0016] FIG. 5 illustrates a top plan view of the hydraulic door closer of FIG. 1 .
[0017] FIG. 6 illustrates a cross-sectional view of the hydraulic door closer of FIG. 5 , taken along line 6 - 6 of FIG. 5 .
[0018] FIG. 7 illustrates a close-up cross-sectional view of the area of the hydraulic door closer denoted by the circled region labelled 7 in FIG. 6 .
[0019] FIG. 8 illustrates a close-up cross-sectional view of the hydraulic door closer denoted by the circled region labelled 8 in FIG. 6 .
[0020] FIG. 9 illustrates a front, exploded view of the hydraulic door closer of FIG. 1 .
[0021] FIG. 10 illustrates a proximal, exploded perspective view of a portion of the hydraulic door closer of FIG. 1 ; in FIG. 10 , the housing is transparent to better show the channels.
[0022] FIG. 11 illustrates a cross-sectional view of the hydraulic door closer of FIG. 1 ; FIG. 11 shows the location of the piston during the process of moving the door from the closed position to the open position.
[0023] FIG. 12 illustrates a cross-sectional view of the hydraulic door closer of FIG. 1 ; FIG. 12 shows the location of the piston when the door is in the open position.
[0024] FIG. 13 illustrates a cross-sectional view of the hydraulic door closer of FIG. 1 ; FIG. 13 shows the location of the piston during the process of moving the door between the opened and closed positions.
[0025] FIG. 14 illustrates a cross-sectional view of the hydraulic door closer of FIG. 1 ; FIG. 14 shows the location of the piston when the door is in the closed position.
[0026] FIG. 15 illustrates a side elevation view of the hydraulic door closer of FIG. 1 in use in a door.
[0027] FIG. 16 illustrates a bottom perspective view of the hydraulic door closer of FIG. 1 ; the spindle is not shown for ease of viewing.
[0028] FIG. 17 illustrates a sectional view of the hydraulic door closer of FIG. 16 , taken along line 17 - 17 of FIG. 16 .
[0029] FIG. 18 illustrates a sectional view of the hydraulic door closer of FIG. 16 , taken along line 18 - 18 of FIG. 16 .
DETAILED DESCRIPTION
[0030] With reference to FIGS. 1-18 , the present invention provides a hydraulic door closer system 10 . In the drawings, not all reference numbers are included in each drawing for the sake of clarity. Preferably, the hydraulic door closer is an overhead concealed door closer. FIGS. 1-18 are engineering drawings, drawn to scale. However, it will be appreciated that other dimensional proportions between the components are possible.
[0031] Referring further to FIGS. 1-18 , in some embodiments, the system is a hydraulic overhead concealed door closer system 10 comprising: a) a door frame 12 defining a door opening 14 , the door frame 12 comprising a door frame width 16 , a door frame height 18 generally perpendicular to the door frame width 16 , and a door frame top 17 located above the door opening 14 ; b) a door comprising a door top 20 and a door width 22 , the door configured to pivot from a closed position in which the door covers the door opening 14 , the door width 22 is substantially parallel to the door frame width 16 and the door top 20 faces the door frame top 17 , to an open position in which the door does not cover the door opening 14 and in which the door width 22 is not substantially parallel to the door frame width 16 ; and c) a hydraulic overhead concealed door closer 24 that may be located in the door frame top 17 . The hydraulic overhead concealed door closer 24 may include i) a housing 26 comprising an interior 28 , a top side 30 , a bottom side 32 opposite the top side 30 and facing the door top 20 when the door is in the closed position, a housing height 34 extending from the housing top side 30 to the housing bottom side 32 and generally perpendicular to the door frame width 16 and the door width 22 , a front side 36 , a rear side 38 , a housing thickness 40 extending from the housing front side 36 to the housing rear side 38 and generally perpendicular to the housing height 34 and generally perpendicular to the door width 22 when the door is in the closed position, a proximal end 44 , a distal end 42 , a housing width 46 extending from the housing proximal end 44 to the housing distal end 42 and generally perpendicular to the housing height 34 and the housing thickness 40 and generally parallel to the door width 22 when the door is in the closed position. The hydraulic overhead concealed door closer 10 may also include a cylinder 48 located in the housing interior 28 , the cylinder 48 having a cylinder length 50 generally parallel to the housing width 46 as well as a moveable piston 52 located in the cylinder 48 and configured to move at least partially along the cylinder length 50 , the moveable piston 52 dividing the housing interior 28 into a proximal chamber 56 and a distal chamber 54 . The door closer may include multiple cylinders 48 , each of which may have a piston 52 . The door closer interior also includes fluid, e.g., hydraulic fluid, located in the proximal chamber 56 and the distal chamber 54 . The door closer 10 may also include at least one channel 58 A and 58 B located in the housing interior 28 and configured to transport hydraulic fluid between the proximal and distal chambers 56 and 54 , the at least one channel 58 A and 58 B having a channel length 60 generally parallel to the housing width 46 and the cylinder length 50 . Multiple channels 58 A and 58 B and drains 119 , 120 , 121 and 122 such as those shown in the drawings are possible. The door closer 10 may also include a cam assembly 62 comprising a spindle 64 , the spindle 64 having a spindle height 66 generally parallel to the housing height 34 and a spindle perimeter 68 generally perpendicular to the spindle height 66 , the spindle 64 extending below the housing bottom side 32 , the spindle 64 configured to rotate about a spindle rotational axis 70 generally parallel to the spindle height 66 (rotate means at least partially rotate). The system may also include an arm 72 attached to the spindle 64 and to the door top 20 . The arm 72 may close around the spindle 64 and be adjustable using for example an Allen wrench. The door closer 10 may also include a top cap 78 having a top cap diameter 80 generally perpendicular to the housing height 34 and sealing the distal chamber 54 from the door frame 12 , the top cap 78 located at the top side 30 of the housing 26 and opposite to the spindle 64 . The top cap 78 may be located directly above the spindle 64 . As shown in the drawings, the spindle 64 generally does not protrude through the top cap 78 . Optionally, pivoting the door from the closed position to the open position is configured to cause the spindle 64 to rotate (i.e., partially rotate) about the spindle rotational axis 70 and cause the piston 52 to move within the cylinder 48 at least partially along the cylinder length 50 . Optionally, the system further comprises a spindle seal 82 , the spindle seal 82 surrounding and compressing against the perimeter 68 of the spindle 64 and located below the top cap 78 . Optionally, the spindle seal 82 comprises a diameter 84 generally perpendicular to the housing height 34 . Optionally, as best seen in FIG. 7 , the spindle seal 82 has an inner wall 83 , an outer wall 85 , a v-shaped channel 87 between the inner wall 83 and outer wall 85 , an open top end 89 (as best seen in FIGS. 2 and 7 ) and a closed bottom end 91 (as best seen in FIGS. 3 and 7 ). Prior to assembly into the housing 26 , the inner wall 83 is angled (e.g., at approximately an angle of between about 10 to about 30 degrees relative to the outer wall 85 ). Once the spindle seal 82 is placed in the housing 26 , it pushes against the spindle 64 for better sealing. The spindle seal 82 may be comprised of rubber, for example.
[0032] Optionally, the system further comprises a bottom bearing 86 located between the spindle seal 82 and the cam assembly 62 , the bottom bearing 86 comprising a diameter 88 generally perpendicular to the housing height 34 . The system may also include a top bearing 128 located above the spindle seal 82 . Optionally, the top cap 78 further comprises a top cap circumference 90 and further wherein the system further comprises an O-ring 92 surrounding the top cap circumference 90 . Optionally, the top cap 78 is attached to the housing 26 via epoxy and threading. Optionally, the top cap 78 and the housing 26 are comprised of the same material. Optionally, the system further comprises at least one valve 94 A, 94 B, and 94 C controlling the flow of the hydraulic fluid within the at least one channel 58 A and 58 B, the at least one valve 94 A, 94 B, and 94 C comprising a valve stem 96 having a valve stem height generally parallel to the housing height 34 and further wherein the valve stem 96 comprises a top ridge 98 (comprising a top ridge diameter perpendicular to the housing height 34 ), a middle ridge 100 located below the top ridge 98 (and comprising a middle diameter generally perpendicular to the housing height 34 ), and a lower ridge 102 located below the top ridge 98 and the middle ridge 100 (and comprising a lower ridge diameter generally perpendicular to the housing height 34 ), a top O-ring 104 located between the top ridge 98 (and comprising a top O-ring diameter generally perpendicular to the housing height 34 ) and the middle ridge 100 and compressing against the valve stem 96 and a lower O-ring 106 located between the middle ridge 100 and the lower ridge 102 and compressing against the valve stem 96 (and comprising a lower O-ring diameter generally perpendicular to the housing height 34 ). The valves 94 A-C, which may be adjustable via a screw driver, may also be secured into housing 26 through the use of locking rings/washers 131 that are stamped into the housing 26 above the valves 94 A-C, and prevent the valves 94 A-C from screwing out of the housing 26 . More particularly, the locking rings 131 may have a diameter that is slightly larger than the diameters of each of the housing ports leading to the valves 94 A-C, and the locking rings 131 are press fit/stamped to force the locking rings 131 through the smaller ports.
[0033] Optionally, the system further comprises at least one end cap 108 located on the distal end 42 of the housing 26 , the end cap 108 comprising an end cap diameter 110 generally perpendicular to the housing width 46 , at least one spring 112 located proximally relative to the end cap 108 and the piston 52 , the spring 112 comprising a distal end 116 attached to the piston 52 and a proximal end 114 , the spring 112 having a relaxed position and a compressed position, and further wherein moving the door from the closed position to the open position is configured to cause the door arm 72 to cause the spindle 64 to rotate about the spindle rotation axis 70 and cause the spring 112 to move from the relaxed position to the compressed position and the piston 52 to move distally (and in the general direction of toward the spindle 64 ) within the cylinder 48 . Optionally, the spring 112 is adjustable by a user, e.g., by turning a component on the end cap 108 . Optionally, the end cap 108 is configured to seal the hydraulic fluid within the proximal chamber 56 and further wherein the housing 26 and the end cap 108 are comprised of the same material. Optionally, the end cap 108 further comprises a circumference and further wherein the system further comprises an end cap O-ring 118 , the end cap O-ring 118 surrounding and compressing against the end cap circumference. Optionally, pivoting the door from the closed position to the open position is configured to cause the piston 52 to move distally (and generally towards the spindle 64 ) and move hydraulic fluid located distal to the piston 52 distally within the cylinder 48 . Optionally, moving the piston 52 distally within the cylinder 48 is configured to cause hydraulic fluid to move from the distal chamber 54 through the at least one channel 58 A and 58 B and into the proximal chamber 56 . Optionally, pivoting the door from the open position to the closed position is configured to cause the piston 52 to move proximally (and generally away from the spindle 64 ) and move hydraulic fluid located proximal to the piston 52 proximally within the cylinder 48 . Optionally, moving the piston 52 proximally within the cylinder 48 is configured to cause hydraulic fluid to move from the proximal chamber 56 through the at least one channel 58 A and 58 B and into the distal chamber 54 .
[0034] Optionally, the system is assembled as shown in FIG. 2 , with the bottom bearing 86 placed in the port/opening 126 in the housing 26 that the top cap 78 closes, followed by the cam assembly 62 , followed by the top cap 78 . The top cap 78 is positioned by moving the top cap 78 toward the port/opening 126 in the housing 26 . As shown, the spindle 64 does not protrude through the top cap 78 .
[0035] The system may be sold without the door, door frame 12 , and arm 72 . The present disclosure may also be used in a method that includes providing the door closer 10 and installing the door closer 10 in a door frame 12 and attaching the door closer 10 to a door.
[0036] The spring 112 may be bolted to the cam assembly 62 using the bolts 130 shown in FIG. 9 .
[0037] The at least one channel may include several channels 58 A and 58 B that are regulated by several valves (e.g., a backcheck valve 94 C which is nearest to the spindle 64 , a sweep valve 94 B, and a latch valve 94 A that is furthest from the spindle 64 ), as well as drains 119 , 120 , 121 , and 122 and balls 123 .
[0038] Operation of the Door Closer
[0039] One example of operation of the door closer 10 will now be described. It will be understood that the operation provided is exemplary.
[0040] The Operation of the Sweep and Latch Valve
[0041] Opening the backcheck valve 94 C reduces backcheck and makes the door easier to open. Closing the sweep valve 94 B and latch valve 94 A makes the sweep and latch closing of the door slower.
[0042] While opening backcheck valve 94 C, close sweep valve 94 B and latch valve 94 A
[0043] The door is moved from the closed position to the open position.
[0044] The spindle 64 rotates, moving the piston 52 distally towards the spindle 64 and the housing distal end 42 , compressing the spring 112 . The piston 52 moves through the backcheck drain hole 119 . Fluid in the distal chamber 54 moves to the proximal chamber 56 by moving through the main hole 132 , upwardly through the backcheck drain hole 119 where the fluid is blocked by steel ball 123 , and then travels through the drain hole 122 .
[0045] The spring 112 relaxes, and the piston 52 moves proximally towards the end cap 108 , causing the spindle 64 to return to the start position.
[0046] With the movement above, opening the sweep valve 94 B makes the fluid in the proximal chamber 56 move to the distal chamber 54 using sweep drain hole 121 , sweep valve 94 B, drain hole 122 and piston 52 .
[0047] When fluid in the distal chamber 54 is moving, if the piston 52 is blocking sweep drain hole 121 , sweeping is done. See FIG. 11 .
[0048] When sweeping is done, opening the latch valve 94 A will allow leftover fluid in the proximal chamber 56 to move back to the distal chamber 54 using latch drain hole 120 , upwardly through latch valve 94 A, downwardly through sweep valve 94 B, out drain hole 122 and piston 52 , as a result the door is fully closed. See FIG. 12 .
[0049] The Operation of the Backcheck Valve
[0050] Fully close backcheck valve 94 C, the door is opened, rotating the spindle 64 and moving the piston 52 distally (toward the spindle 64 ), as fluid moves from the distal chamber 54 to the proximal chamber 56 via the backcheck drain hole 119 . While the piston 52 is blocking the backcheck drain hole 119 , the piston 52 cannot move since fluid is controlled by backcheck drain hole 119 only. See FIG. 12 .
[0051] When the piston 52 is not moving, the spindle 64 cannot rotate further due to the intense pressure in the housing interior 28 . This is what is referred to as backcheck.
[0052] (When the backcheck valve 94 C is fully closed, a very small amount of oil flows in the gap between the cylinder 48 and piston 52 , allowing the door to open slowly further).
[0053] The items referred to above are labelled in the drawings per the below legend.
[0000]
system
10
door frame
12
door opening
14
door frame width
16
door frame height
18
door top
20
door width
22
closer
24
housing
26
interior
28
housing top
30
housing bottom
32
housing height
34
front side
36
rear side
38
housing thickness
40
distal end
42
proximal end
44
housing width
46
cylinder
48
cylinder length
50
piston
52
distal chamber
54
proximal chamber
56
channel
58A & B
channel length
60
cam assembly
62
spindle
64
spindle height
66
spindle perimeter
68
spindle rotational axis
70
arm
72
top cap
78
top cap diameter
80
spindle seal
82
Spindle seal inner wall
83
spindle seal diameter
84
Spindle seal outer wall
85
bottom bearing
86
Spindle seal groove
87
bottom bearing diameter
88
Spindle seal top
89
top cap circumference
90
Spindle seal bottom
91
top cap o-ring
92
at least one valve
94A, B, C
valve stem
96
top ridge
98
middle ridge
100
lower ridge
102
top o-ring
104
lower o-ring
106
end cap
108
end cap diameter
110
spring
112
spring distal end
114
spring proximal end
116
end cap o-ring
118
back check drain hole
119
latch drain hole
120
sweep drain hole
121
drain hole
122
steel ball
123
Port of housing
126
Top Bearing
128
Bolts
130
Locking ring
131
Main drain hole
132
[0054] Having now described the invention in accordance with the requirements of the patent statutes, those skilled in the art will understand how to make changes and modifications to the disclosed embodiments to meet their specific requirements or conditions. Changes and modifications may be made without departing from the scope and spirit of the invention. In addition, the steps of any method described herein may be performed in any suitable order and steps may be performed simultaneously if needed.
[0055] Terms of degree such as “generally”, “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. In addition, the steps of the methods described herein can be performed in any suitable order, including simultaneously.
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A hydraulic door closer is disclosed. The hydraulic door closer may include a top cap surrounded by an O-ring that is located at the top of the hydraulic door closer housing opposite a spindle to seal the hydraulic fluid within the housing. In addition to or in lieu of the top cap design, the door closer may include a locking washer to secure the valves to the housing; epoxy and an O-ring at the interface between the top cap and the housing of the door closer; use of a dual-walled rubber seal around the spindle; use of dual O-rings on each valve stems; use of caps that are made of the same material as the housing instead of aluminum and use of epoxy on the end caps; and/or use of backcheck with an adjustable spring.
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DESCRIPTION
BACKGROUND OF THE INVENTION
This invention relates to a cross-linkable positive-working ionizing radiation-resist or ultraviolet ray-resist polymer composition and to a method of forming a positive resist pattern on a substrate using the resist polymer composition.
Polymethyl methacrylates have heretofore been widely used as positive-working resists in electron or X-ray lithography. Although the polymethyl methacrylate resists exhibit satisfactory resolution, their sensitivity to radiation is poor. In other words, there is only a slight difference in solubility between irradiated regions and non-irradiated regions, particularly at low ionizing radiation exposures. Accordingly, it has eagerly been desired to provide polymeric resist materials exhibiting a resolution approximately similar to and a sensitivity far greater than those of the conventional polymethyl methacrylate resists.
In order to provide methyl methacrylate polymer resists of improved sensitivity, it has been proposed to copolymerize methyl methacrylate with a sensitivity-enhancing acrylic monomer such as hexafluorobutyl methacrylate. However, such a methyl methacrylate copolymer resist is still unsatisfactory in that it has an undesirably low softening point and a poor thermal resistance as compared with the conventional polymethyl methacrylate resists.
In U.S. Pat. No. 3,981,985, a mixture comprised of (a) a copolymer of a monoolefinically unsaturated carboxylic acid, such as methacrylic acid, and a monoolefinically unsaturated compound, such as methyl methacrylate, and (b) a copolymer of a monoolefinically unsaturated carboxylic acid chloride, such as methacrylic acid chloride and a monoolefinically unsaturated compound was also proposed for use as a polymer resist. The proportions of the two copolymers (a) and (b) in this mixture are such that the carboxylic acid and the carboxylic acid chloride are essentially stoichiometric. When a resist coating of this mixture is heated, carboxylic acid anhydride cross-links are formed, and thus the resist coating becomes thermally resistant. However, the sensitivity of this resist coating is still not completely satisfactory.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide positive-working ionizing radiation-resist or ultraviolet ray-resist polymeric materials which exhibit enhanced sensitivity as well as good thermal resistance, contrast and resolution.
The other objects and advantages of the present invention will be apparent from the following description.
One aspect of the present invention provides a cross-linkable positive-working ionizing radiation-resist or ultraviolet ray-resist polymer composition, comprising, in polymerized form,
(a) approximately 70 to 99% by mole of units derived from a methacrylic acid ester of the formula:
CH.sub.2 ═C(CH.sub.3).COOR
wherein R is an alkyl or haloalkyl group having from 1 to 6 carbon atoms, a benzyl group or a cyclohexyl group,
(b) approximately 1 to 20% by mole of units derived from methacrylamide, and
(c) approximately 0.05 to 20% by mole of units derived from methacrylic acid chloride;
each amount of the units (a), (b) and (c) being based on the total moles of the units (a), (b) and (c). The unexpected advantage of the present invention resides primarily in the fact that its sensitivity is far more enhanced than the sensitivity of the positive resist polymer composition described in U.S. Pat. No. 3,981,985, which contains substantially stoichiometric amounts of monoolefinically unsaturated carboxylic acid units and monoolefinically unsaturated carboxylic acid chloride units.
DETAILED DESCRIPTION
The positive resist polymer composition of the present invention is in the form of either a terpolymer comprised of the methacrylic acid ester units (a), the methacrylamide units (b) and the methacrylic acid chloride units (c), or a blend of at least two polymers, each of which is comprised of at least one of the units (a), (b) and (c). Preferably, the polymer composition is either the terpolymer of the units (a), (b) and (c) or a blend of a copolymer comprised of the units (a) and (b) with a copolymer comprised of the units (a) and (c).
When a coating of either of the above mentioned polymer compositions is applied to a substrate and heated, dehydrochlorination occurs between the acid amide groups and the acid chloride groups, and a three-dimensional network of acid imide cross-links is formed. This polymer network is insoluble in a solvent used as a developer. It is presumed that, when the polymer network is irradiated with ionizing radiation or ultraviolet rays, both the main chains and the cross-links of the polymer network are destroyed at the irradiated regions, and the polymers are degraded into lower molecular weight polymers. These degraded, lower molecular weight polymers are soluble in a developer solvent, and, when an irradiated pattern in the polymer resist is developed by using a solvent, the polymers in the irradiated regions are selectively removed so as to leave the positive resist pattern on the substrate.
The methacrylic acid esters used for the preparation of the positive resist polymer composition are esters of an alkyl or haloalkyl group having from 1 to 6 carbon atoms, a benzyl group and a cyclohexyl group. The methacrylic acid esters include, for example, methyl methacrylate, tert.-butyl methacrylate, iso-propyl methacrylate, hexafluorobutyl methacrylate, hexafluoroisopropyl methacrylate, cyclohexyl methacrylate and benzyl methacrylate. These methacrylic acid esters may be used either alone or in combination. The amount of the methacrylic acid esters may be varied in the range of from about 70 to about 99% by mole based on the total moles of all monomers used for the preparation of the polymer composition. When the amount of the methacrylic acid esters is too small, the sensitivity of the positive resists is poor. In contrast, when the amount of the methacrylic acid esters is too large, both the thermal resistance and solvent resistance of the polymer resists are poor.
The amount of methacrylamide may range from about 1 to about 20% by mole, preferably from about 2 to about 10% by mole, based on the total moles of all monomers used for the preparation of the polymer composition. When the amount of the methacrylamide is too small, the positive resists have, when heated, an undesirably low degree of cross-linking and are thus relatively soluble in a solvent developer and poor with respect to thermal resistance and sensitivity. In contrast, when the amount of the methacrylamide is too large, the degree of cross-linking is undesirably high and the sensitivity is quite poor.
The amount of methacrylic acid chloride may range of from about 0.05 to about 20% by mole, preferably from about 0.3 to about 3% by mole, based on the total moles of the monomers used for the preparation of the polymer composition. When the amount of methacrylic acid chloride is outside this range, the polymer resists are unsatisfactory, similar to the case where the amount of the methacrylamide is outside the above-mentioned range.
The polymer composition of the present invention may contain, in addition to the above-mentioned methacrylic acid ester, methacrylamide and methacrylic acid chloride units, usually less than 50% by weight, based on the total weight of the polymer composition of units derived from other monoolefinically unsaturated monomers, provided that the polymer resists are not harmfully influenced.
The molar ration of the methacrylamide to the methacrylic acid chloride should preferably be within the range of from about 2/3 to about 100/3 by mole in order to achieve the desired resist characteristics.
The polymer composition of the present invention, which is in the form of either a terpolymer of the above-mentioned units (a), (b) and (c), or a blend of polymers, each containing at least one of the units (a), (b) and (c), may be prepared in a conventional manner. The molecular weight of the polymer composition may range from about 30,000 to about 1,000,000, preferably from about 30,000 to about 400,000, as determined by a gel permeation chromatography procedure. The ratio of the weight average molecular weight to the number average molecular weight may range from 1/1 to 4/1, preferably from 1/1 to 2/1.
A positive resist pattern may be produced on a substrate as follows. A solution of the polymer composition in a solvent such as, for example, 2-ethoxyethyl acetate, 2-methoxyethyl acetate or cyclohexanone, is coated on a substrate by using, for example, a spinner. Then, the coating of the polymer composition is usually heated to a temperature of 140° to 220° C. for a period of 5 to 30 minutes. The optimum temperature and time period are approximately 200° C. and approximately 15 minutes, respectively. The polymer network resist so formed is irradiated with ionizing radiation such as electron rays, X-rays or ultraviolet rays in accordance with a desired pattern until the acid-imide cross-links and the main chains are broken at the irradiated regions. The irradiated resist is developed by applying thereto a developer solvent, such as methyl isobutyl ketone, ethyl acetate or acetone so as to leave the positive resist pattern on the substrate.
The invention will be explained in more detail by the following illustrative examples, in which some of the characteristics of the positive resists were determined as explained. Irradiation was carried out in accordance with a vector scanning procedure by using an electron exposing apparatus (Cambridge Instrument EBMF-1).
Contrast "γ" was determined in accordance with the equation:
γ=0.5/[log(D.sub.0 /D.sub.0.5)],
wherein D 0 is the electron dose in C/cm 2 required to reduce the initial resist thickness to zero and D 0 .5 is the electron dose in C/cm 2 required to reduce the initial resist thickness to a half thereof. The initial resist thickness was 0.5 micron as measured after the coated resist was baked in order to form cross-links.
Sensitivity was expressed in terms of the electron dose (C/cm 2 ) required to reduce the polymer resist thickness from 0.5 microns to zero, at least one part thereof, when the irradiated polymer resist was dipped in methyl isobutyl ketone or another liquid developer at a temperature of 20° C. for one minute. The smaller the electron dose, the greater the sensitivity.
Resolution was evaluated by determining the minimum possible size of each line and each space during the production of a parallel line resist pattern having lines and spaces of the same size, and further by determining the maximum possible height to width ratio of each linear ridge of the line pattern.
Thermal stability was evaluated in terms of the softening temperature, determined by using a scanning type electron microscope to observe the shape of the resist of a parallel line pattern while the resist was gradually heated in a nitrogen atmosphere. The softening temperature is defined as the lowest temperature at which the polymer resist loses its predetermined shape and starts to flow. Furthermore, thermal stability was evaluated in terms of the thermal decomposition temperature, which is determined according to a thermogravimetric analysis wherein a polymer resist specimen is heated in a nitrogen atmosphere at a rate of 10° C./min. The thermal decomposition temperature is defined as the temperature at which the weight of the specimen starts to be reduced.
EXAMPLE 1
95.0% by mole of methyl methacrylate (MMA), 2.5% by mole of methacrylamide (MAA) and 2.5% by mole of methacrylic acid chloride (ClMA) were copolymerized by using a conventional solution polymerization procedure. The terpolymer obtained (M.W.=250,000) was dissolved in 2-ethoxyethyl acetate to obtain a 9.0% by weight solution. This solution was coated on a silicon substrate using a spinner rotating at 4,500 rpm. The thickness of this coating when dry was 0.6 microns. The coated substrate was next heated at a temperature of 200° C. for a period of 15 minutes. Then, the coated substrate was irradiated with electron rays by using an electron beam accelerator at an accelerating voltage of 30 kV. The irradiated substrate was dipped in ethyl acetate at a temperature of 20° C. for one minute to obtain a resist of the line pattern (specimen 1).
For comparison purposes, similar positive resists were prepared from a terpolymer (M.W.=250,000, specimen 2) made from a mixture of 93.5% by mole of methyl methacrylate (MMA), 5% by mole of methacrylamide (MAA) and 1.5% by mole of methacrylic acid chloride (ClMA); a terpolymer (M.W.=250,000, specimen 3) made from a mixture of 89.5% by mole of methyl methacrylate (MMA), 10% by mole of methacrylamide (MAA) and 0.5% by mole of methacrylic acid chloride (ClMA); a terpolymer (M.W.=300,000, comparative specimen 1) made from a mixture of 95.0% by mole of methyl methacrylate (MMA), 2.5% by mole of methacrylic acid (MA) and 2.5% by mole of methacrylic acid chloride (ClMA); and a conventional polymethyl methacrylate (PMMA, M.W. 300,000, comparative specimen 2). The procedures used in the preparation of these positive resists were similar to those mentioned above with respect to the specimen of the present invention, except that the polymethyl methacrylate resist (comparative specimen 2) was developed at a temperature of 20° C. for one minute by using a methyl isobutyl ketone/isopropyl alcohol mixture having a volume ratio of 1/3.
The characteristics of the positive polymer resists are shown in Table I, below.
TABLE I______________________________________Specimen 1 2 3 Com. 1 Com. 2______________________________________Composition MMA 95.0 93.5 89.5 95.0 100(mole %) MAA 2.5 5.0 10.0 MA 2.5 0 ClMA 2.5 1.5 0.5 2.5 0______________________________________Contrast (γ) 5.8 5.2 4.3 4.0 3.1Sensitivity (C/cm.sup.2) 2 × 1 × 6 × 5× 1.6 × 10.sup.-5 10.sup.-5 10.sup.-6 10.sup.-5 10.sup.-4Resolutionmin. size of line and 0.2 0.2 0.2 0.2 0.2space (μ)max. ratio of H/W 7 6 6 6 2.5Thermal stabilitySoftening temp. (°C.) 145 150 155 140 110Decomposition temp. 320 320 330 300 250(°C.)______________________________________
EXAMPLE 2
Following a procedure similar to that mentioned in Example 1, a polymer resist pattern was produced wherein the following copolymer blend was used instead of the MMA/MAA/ClMA terpolymer. The copolymer blend used was comprised of 50% by weight of a copolymer (M.W.=250,000) of 92.0% by mole of methyl methacrylate (MMA) and 8.0% by mole of methacrylamide (MAA) and 50% by weight of a copolymer (M.W.=180,000) of 98.8% by mole of methyl methacrylate (MMA) and 1.2% by mole of methacrylic acid chloride (ClMA).
The characteristics of the polymer resist pattern are shown in Table II, below.
EXAMPLE 3
Following a procedure similar to that mentioned in Example 1, a polymer resist pattern was produced wherein the following terpolymer was used instead of the MMA/MAA/ClMA terpolymer. The terpolymer used was prepared by using a conventional solution polymerization procedure and was comprised of 95.0% by mole of benzyl methacrylate (BzMA), 4.0% by mole of methacrylamide (MAA) and 1.0% by mole of methacrylic acid chloride (ClMA). The terpolymer had a M.W. of approximately 200,000.
The characteristics of the polymer resist pattern are shown in Table II, below.
TABLE II______________________________________Specimen Ex. 2 Ex. 3______________________________________Composition MMA 46.0 BZMA 95.0(mole %) MMA 4.0 MAA 4.0 MMA 49.4 ClMA 1.0 ClMA 0.6______________________________________Contrast (γ) 4.3 3.5Sensitivity (C/cm.sup.2) 6 × 10.sup.-6 8 × 10.sup.-6Resolutionmin. size of lin 0.2 0.3space (μ)max. ratio of H/W 6 5Thermal stabilitySoftening temp. (°C.) 150 135Decomposition temp. (°C.) 320 300______________________________________
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PCT No. PCT/JP78/00021 Sec. 371 Date July 2, 1979 Sec. 102(e) Date July 7, 1979 PCT Filed Nov. 6, 1978 PCT Pub. No. WO79/00283 PCT Pub. Date May 31, 1979
A cross-linkable positive-working ionizing radiation-resist or ultraviolet ray-resist polymer composition comprising, in polymerized form,
(a) from about 70 to about 99% by mole of units derived from a methacrylic acid ester of the formula:
CH.sub.2 ═C(CH.sub.3). COOR
where R is an alkyl or haloalkyl group having from 1 to 6 carbon atoms, a benzyl group or a cyclohexyl group,
(b) from about 1 to about 20% by mole of units derived from methacrylamide, and
(c) from about 0.05 to about 20% by mole of units derived from methacrylic acid chloride;
each amount of the units (a), (b) and (c) being based on the total moles of the units (a), (b) and (c). The polymer composition is preferably in the form of either a copolymer comprised of the units (a), (b) and (c), or a blend of a copolymer comprised of the units (b) and a portion of the units (a) and a copolymer comprised of the units (c) and the remainder of the units (a). The resist polymer composition exhibits enhanced sensitivity as well as good thermal resistance, contrast and resolution.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 13/181,220 (filed Jul. 12, 2011) which is a continuation of Ser. No. 12/330,871 (filed Dec. 9, 2008), now U.S. Pat. No. 8,006,679 which claims the priority date of U.S. Provisional Application Ser. No. 61/062,380, entitled “COMPOUND ARCHERY BOW” filed Jan. 25, 2008. The content of the aforementioned patent applications is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
This invention relates to compound bows, and more specifically, it relates to a two-track system for bow strings and power cables of the compound bow.
Cams have been used on compound bows for some time. Compound bows have opposing limbs extending from a handle portion which house the cam assemblies. Typically, the cam assemblies are rotatably mounted on an axel which is then mounted on a limbs of bow. The compound bows have a bow string attached to the cam which sits in a track and also, generally, two power cables that each sit in a track on a separate component on the cam, and either anchored to the cam or a limb/axel. When a bowstring is pulled to full draw position, the cam is rotated and the power cables are “taken up” on their respective ends to increase energy stored in the bow for later transfer, with the opposing ends “let out” to provide some give in the power cable.
Cam assemblies are designed to yield efficient energy transfer from the bow to the arrow. Some assemblies seek to achieve a decrease in draw force closer to full draw and increase energy stored by the bow at full draw for a given amount of rotation of the cam assembly.
There exists a number of U.S. patents directed to compound bows, including U.S. Pat. No. 7,305,979 issued to Craig Yehle on Dec. 11, 2007. The Yehle patent discloses a cam assembly having a journal for letting out a draw cable causing the cam to rotate and two other journals for take-up mechanism and a let-out mechanism for the two power cables. The Yehle patent requires that the power cables and draw string each sit in a different components and tracks for the take up and let out mechanism to work and to have the efficiencies described therein.
Therefore, a compound bow having a mechanism with fewer tracks is desired because of the advantage in assembly in manufacturing and to increase efficiency in the transfer of energy to propel bows.
Further, an adjustable or modular take-up/let-out mechanism is desired to account for different size draw lengths or other specifications required by the user.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE INVENTION
The invention comprises, in one form thereof, a cam assembly comprising bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable.
More particularly, the invention includes a compound bow comprising a handle portion; a limb portion; at least two cam assemblies, each comprising a bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable, a draw stop pin, a take up terminating post, and a let out terminating post; an axel; at least two power cables; and a bowstring.
The cam assembly has a two track system wherein the power cables utilize a track or opposing tracks made on the power cable component of the cam assembly. Another track is formed on the bowstring component of the cam assembly in which the bowstring lies.
An advantage of the present invention is that the device has high efficiency in transferring energy stored in the limbs during the draw cycle to the arrow or other projectile of the device.
A further advantage of the present invention is that it requires less component parts for cam assembly which is highly desirable in the art.
An even further advantage of the present invention is that the cam assembly allows for a modular format which allows the user to change minor components to change parameters of the device (e.g. draw length) without having to change the entire cam assembly or bow.
This brief description of the invention is intended only to provide a brief overview of subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:
FIG. 1 is a side view of a dual cam compound bow embodying the present invention;
FIG. 2 is a side view of the top cam assembly in a first embodiment of the present invention.
FIG. 3 is a rearview of the top cam assembly in a first embodiment of the present invention.
FIG. 4 is a side view of the bottom cam assembly in a first embodiment of the present invention.
FIG. 5 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
FIGS. 6 and 7 show the modular form of the let out portion 64 a,b with the draw stop pin 90 a,b attached thereto.
FIG. 8 is a side view of the top cam assembly in a second embodiment of the present invention.
FIG. 9 is a side view of the bottom cam assembly in a second embodiment of the present invention.
FIG. 10 is a side view of the top cam assembly in a third embodiment of the present invention.
FIG. 11 is a side view of the bottom cam assembly in a third embodiment of the present invention.
FIG. 12 is a rearview of the top cam assembly in a fourth embodiment of the present invention.
FIG. 13 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate a few embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a dual cam compound bow 10 of the present invention. The bow 10 has a frame, which includes bow limbs 12 a,b extending from handle 14 . Extending from the handle is cable guard 16 and a cable slide 18 through which the power cables 50 and 52 are placed. The bowstring 70 and power cables 50 , 52 are attached to the bow 10 at the cam assemblies 30 a,b , which further is placed on the limbs via axel 36 a,b . The cams 30 a,b are shown in greater detail in the following figures.
The cams 30 a,b have bowstring assemblies 40 a,b , each having a single track for the bowstring 70 with each end of the bowstring 70 being attached to the cams 30 a,b at a terminating post (not shown). Further, the each of the cams 30 a,b have terminating posts 80 , 82 for each of the ends of the respective power cables 50 , 52 , and which will be described in more detail herein. Further, each cam assembly 30 a,b has a power cable assembly 60 a,b having either a single track or groove around perimeter of the assembly 60 a,b for receiving or retaining the power cables. Alternatively, the power cable assembly 60 a,b can have the tracks or grooves on the portions of the assembly receiving the cable instead of a unitary track around the perimeter. The power cable assembly 60 a,b has a take up portion 62 a,b and a let out portion 64 a,b for managing the take up and let out of the power cables through a single track.
FIG. 2 shows a side view of the top cam assembly 30 a . FIG. 2 shows one embodiment of the cam 30 a in non-circular shape. The bowstring 70 is in line with the track in the bowstring assembly 40 a and attached with a terminating post (not shown). The power cable assembly 60 a has a take up portion 62 a and a let out portion 64 a , and can either be a unitary piece or be modular. For instance as shown in FIG. 2 , the power cable assembly 60 a has a modular unit for the let out portion 64 a , which allows manufacturers to make a single cam assembly with one small piece that can account for varying sizes and preferences by the user. Specifically, this versatility is important because each hunter or archer has different specifications (e.g. draw length) which can be accounted for by having a modular portion to the cam assembly 30 a , and in this case is the let out portion 64 a . The power cable 52 , in FIG. 2 , is attached to terminating post 82 a and wraps around the let out portion 64 a and therefore feeds power cable 52 out when the bow is in full draw. On the opposing side of power cable assembly 60 a is power cable 50 , which sits on the take up portion 62 a of the assembly 60 a . Power cable 50 is attached at terminating post 80 a , and is taken up when the bow is in full draw by the take up portion 62 a . The power cable assembly 60 a is attached to the bowstring assembly 30 a by a fastening mechanism, but it will be well recognized the power cable assembly 60 a can be attached to the bowstring assembly 40 a by any means or, if desired, manufactured as a single piece with the bowstring assembly 40 a to make-up top cam assembly 30 a . As shown, the power cable assembly 60 a is attached to the bowstring assembly 40 a by a fastener 78 a . The cam assembly 30 a is attached to the limb 12 a by axel 36 a . Last the take power cable assembly 60 a , either in a unitary form or modular form, may optionally have draw stop pin 90 a attached to stop the draw cycle of the bow. The draw stop pin 90 a , however, does not have to be attached to the power cable assembly 60 a in order to function on the cam assembly 30 a.
FIG. 3 shows the rearview of the top cam assembly. As seen from this perspective, the cam assembly 30 a has one track on the bowstring assembly 40 a for the bowstring 70 and a second track for the power cables 52 and 50 (not shown) on same track but on opposing sides of the power cable assembly 60 a . In FIG. 3 , the let out portion 64 a is visible with power cable 52 sitting in the track or groove. Axel 36 a is inserted through the limb 12 a and then the cam assembly 30 a and then the other end of the limb 12 a.
FIG. 4 shows a side view of the bottom cam assembly 30 b . FIG. 4 shows the bottom cam 30 b in non-circular shape as well. The bowstring 70 is in bowstring assembly 40 b and attached with a terminating post (not shown). The power cable assembly 60 b has a take up portion 62 b and a let out portion 64 b , which can either be a unitary piece or as shown can have a modular unit. In FIG. 4 , there is a modular assembly shown where the let up portion 64 b can be changed in size and shape according to the user's specifications. The power cable 52 , in FIG. 4 , is attached to terminating post 80 b and wraps around the take up portion 62 b and therefore is taken up when the bow is in full draw. On the opposing side of power cable assembly 60 b is power cable 50 , which attaches to terminating post 82 b and wraps around the let out portion 64 b , and is let out when the bow is in full draw position. The power cam assembly 60 b is attached to the bowstring assembly 30 b by a fastening mechanism, the two assemblies can be attached by any means or if desired manufactured as a single piece. As shown, the power cable assembly 60 b is attached to the bowstring assembly 40 b by a fastener 78 b . The cam assembly 30 b is attached to the limb 12 b by axel 36 b . Last the power cable assembly 60 b , either in a unitary or modular form, may optionally have draw stop pin 90 b attached to stop the draw cycle of the bow.
FIG. 5 shows the rearview of the bottom cam assembly 30 b . As seen from this perspective, the cam assembly 30 b has a bowstring assembly 40 b for the bowstring 70 , and a power cable assembly 60 b for both power cables 50 , 52 . In FIG. 5 , power cable 50 is visible because it is sitting on the let out portion 64 b of the power cable assembly 60 b . Axel 36 b allows bottom cam assembly 30 b to rotate when the drawstring is pulled, and holds bottom cam assembly 30 b in limb 12 b.
FIGS. 6 and 7 show the modular form of the let out portion 64 a,b and draw stop pin 90 a,b for the cam assemblies 30 a,b . The let out portion 64 a,b and draw stop pins 90 a,b can be attached in any number of ways or can be further manufactured as a unitary piece. Further, as described above, let out portion 64 a,b can be manufactured as a single part of power cable assembly 60 a,b . Therefore, though the modular form is more desirable to personalize the parameters of the device size (e.g. draw length), the cam assembly could be manufactured as a single unit or in varying degrees of pieces.
FIGS. 8 and 9 show a side view of a second embodiment of the present invention 100 a,b . FIG. 8 shows the top cam assembly 100 a is in a circular shape. In particular, the power cable assembly 120 a is shown as being in a unitary form, having the take up portion 122 a and let out portion 124 a . The draw stop pin 90 a is not attached to the power cable assembly 120 a , though if preferred the assembly 120 a could be attached to the pin 90 a . Further the bowstring assembly 110 a is also in a circular or disc shape with power cable assembly 120 a attached thereto. FIG. 9 exemplifies the bottom cam assembly 100 b for the second embodiment, which is in a circular or disc shape. Generally the other components of the cam assemblies 100 a,b are similar to those shown in the first embodiment.
FIGS. 10 and 11 show a third embodiment of the present invention, wherein the cam assembly 200 a,b have a circular portion for the bowstring track 110 a,b and a non-circular power cable assembly 60 a,b . It will be understood that other embodiments could include a non-circular portion for the bowstring assembly and a circular power cable assembly and, again, can be either modular or unitary form. Further other geometrical shapes, such as ovular, may be used in varying forms for either the bowstring or power cable assembly.
Still another embodiment could include a three track system, as shown in the rearview perspectives of FIGS. 12 and 13 . The three track system would be used where there are four power cables. This type of embodiment would include two power cable assemblies as described above, both of which would be attached to the bowstring assembly.
In use, using the first embodiments as an exemplar and in reference to FIGS. 1-3 , the bowstring 70 is pulled rearward toward the hunter or archer. The tension by the bowstring forces the cam assemblies 30 a,b to rotate rearward. Focusing on FIG. 1 , the power cable assembly 60 a on top cam assembly 30 a is moved upward as the entire cam 30 a is moved rearward. The terminating post 80 , with power cable 50 attached, moves upward, and therefore causes take up of power cable 50 . On the bottom cam assembly 30 b the cam 30 b is also moved rearwardly. The positioning of the power cable assembly 60 and power cable 50 causes power cable 50 to be let out on the bottom cam assembly 30 a . The same is true in the opposite manner for power cable 52 (i.e. power cable 52 is taken up) on the cam assemblies 30 a,b . Accordingly energy is stored in the limbs of the device and transferred to the arrow or other projectile placed in the compound bow in a highly efficient manner with little shock to the user.
Though the compound bow embodying the invention may have differing specifications, the bow may have a brace height of about eight (8) inches and axel-to-axel length of about thirty-two and half (32½) inches. The draw length can range from twenty-seven (27) to thirty (30) inches and a draw weight between sixty (60) to eighty (80) inches.
It should be particularly noted that dual track cam disclosed in this invention has a highly efficient and powerful performance. With respect to speed, the following performance results were noted in a twenty-nine (29″) inch draw cycle, sixty pound (60 lbs.) draw weight compound bow, in testing completed by Archery Evolution:
Arrow (Grains)
300
360
420
540
Speed (ft./sec.)
307.3
283.5
264.2
235.4
Kinetic Energy (ft.lbs.)
62.9
64.2
65.1
66.4
Momentum
13.2
14.6
15.9
18.2
Dynamic Efficiency
83.7%
85.5%
86.7%
88.5%
Noise Output (dBA)
88.7
84.1
85.5
87.1
Total Vibration (G)
222.8
234.4
228.7
188.6
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
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The present invention comprises a two-track cam assembly wherein the cam assembly has a bowstring component for housing the bowstring and a power cable component that allows for the take up and let out of the power cable on opposing ends of the power cable component, effectively creating a two-track cam assembly. The efficiency rating of the device achieves 95.8%. The cam assembly can come in a unitary or modular form and further each component (i.e. the bowstring or power cable component) can be in a circular or non-circular form.
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BACKGROUND
[0001] This invention relates generally to flooring tools, and in particular to cushion back cutters. A cushion back cutter is a tool for precisely trimming the edges of carpet seams in preparation for making the seams. As shown in FIG. 1 , a prior art cushion back cutter 100 has a body 110 ; a row separator 115 ; a row guide 120 that is a straight, thin, beveled surface forming the bottom of the cutter; a blade holding pocket 125 for holding a slotted razor blade 130 ; and a blade thumbscrew 140 . FIG. 2 shows greater detail of one slotted razor blade 130 that is commonly used in the carpet installation trade and in particular with cushion back cutters. Slotted razor blade 130 is generally rectangular in shape, and both long sides have edges 132 that are sharpened along their entire length. Slotted razor blade 130 also includes central slot 134 .
[0002] As shown in FIG. 1 , to install slotted razor blades 130 into the prior art cushion back cutter, blade thumbscrew 140 must first be unscrewed and completely removed. Next, the user inserts the blades in the bottom of blade holding pocket 125 (which has an opening in the bottom of the cutter). Blade thumbscrew 140 can then be re-inserted through a hole in one side of the body, through the central slot 134 in the slotted razor blade 130 , and can be tightened into a nut (not shown) welded onto the outside of the opposite side of the body. The slotted razor blade can be extended or retracted from bottom of row guide 120 by loosening the blade thumbscrew 140 and moving the blade inwardly or outwardly from within the blade holding pocket 125 .
[0003] The angle A of the blade holding pocket 125 holds the slotted razor blade 130 at an angle A of approximately 30° so that a surface B of an edge 132 is exposed to cut the carpet's backing. Surface B is long and cuts with a slicing action. This improves cutting efficiency and blade life, which is important when cutting through coarse carpet backings with thick attached cushions. The distance C between the bottom of the row guide 120 and the bottom corner of slotted razor blade 130 determines the depth of cut. The thicker the carpet's backing, the greater the distance the slotted razor blade 130 must be extended. When the desired depth of cut is established, blade thumbscrew 140 is tightened down, and the cutter is ready to trim seam edges.
[0004] Carpet tufts are inserted into carpet backing material in lines. To use cushion back cutter 100 , the front of the cutter at row separator 115 is first used as a kind of divider to start a small parted area between two lines of carpet tufts. Once the small parted area is formed, the cutter is pushed forward at handle 180 and row guide 120 maintains the part between the lines of tufts. As shown in FIG. 8 , once row guide 115 enters a row between a left line of tufts 201 and a right line of tufts 202 , row guide 115 is able to guide the forward motion of the cutter and to position slotted razor blade 130 between the rows of tufts. Thus, as slotted razor blade 130 moves forward with the cutter, the slotted razor blade 130 should cut through the carpet's backing 203 , including any attached cushion 204 , but should not cut into carpet tufts.
[0005] In prior art cushion back cutters, a single slotted razor blade may be inserted into the blade holding slot of the cutter, or a number of them may be inserted. In some prior art cushion back cutters, two or more slotted razor blades are inserted within the same blade holding slot, but only one of them is extended to a cutting position to trim the seam edge (with the others being retracted into blade holding slot). As disclosed in U.S. Pat. No. 3,453,401 to Scott, two slotted razor blades are inserted, but only one is extended to a cutting position, to cut closely to the carpet tufts on the left or right side of a carpet row as desired. When the blade cuts closely to the tufts, a minimum amount of carpet backing will remain at the finished seam, which can reduce unsightly gaps between the tufts. Alternatively, as disclosed in U.S. Pat. No. 3,453,401 to Anderson, the cutter may hold three blades in order to cut left, right, or dead center (as may be required on certain carpets).
[0006] Prior art cushion back cutters are economically produced by spot welding stamped sheet metal parts together. As shown in FIG. 3 , the prior art cushion back cutter 100 includes a left side plate 150 , a center plate 160 , and a right side plate 170 , all of which are spot welded together to form the body 110 of the cutter. A slot 162 in center plate 160 provides the necessary space to form blade holding pocket 125 in the middle of the cutter that receives slotted razor blades 130 . Left side plate 150 and right side plate 170 form the left and right walls of blade holding pocket 125 . Center plate 160 includes a bottom bevel 164 forming the row guide 120 of the cutter. Left side plate 150 includes a blade thumbscrew hole 152 and a blade window 154 marked with blade window graduations 156 for setting blade depth. Right side plate 170 includes a nut 172 spot welded onto its outer surface for blade thumbscrew 140 .
[0007] A problem with the prior art cushion back cutter 100 relates to blade change. Slotted razor blades 130 become dull after trimming long lengths of carpet seam edges, and must be changed repeatedly. Moreover, because the slotted razor blade is sharpened on both edges 132 , and because only surface B ( FIG. 1 ) of the blade 130 is being used for actual cutting, the slotted razor blade can be removed from the cutter, rotated, and re-used up to three more times after the first edge becomes dull. But this requires that the user perform the required steps to change or rotate a blade.
[0008] As shown in FIG. 3 , to change or rotate a slotted razor blade 130 , blade thumbscrew 140 must be completely unscrewed and removed from the cutter. This is because blade thumbscrew 140 runs through central slot 134 in slotted razor blades 130 . Removing blade thumbscrew 140 is time-consuming and can result in loss of the thumbscrew, which is an expensive part. Furthermore, the maximum depth that the slotted razor blade can cut is limited by the upper end 135 of central slot 134 of slotted razor blade 130 hanging up on blade thumbscrew 140 .
[0009] It would therefore be desirable to have some other means to hold the blades that did not pass a screw through their central slot, which could improve efficiency of blade change and rotation and might also allow the blade to be extended further to cut thicker carpet backings and attached cushion.
[0010] As shown in FIG. 1 , another problem with the prior art cushion back cutter 100 relates to the row guide 120 forming the base of the cutter. In prior art cushion back cutters, row guide 120 is formed as a continuous, straight bottom surface on cushion back cutter 100 . In some cushion back cutters, the row guide 120 may be beveled to improve its ability to penetrate and follow between the lines of carpet tufts.
[0011] However, because row guide 120 is formed as a straight and continuous surface, if a carpet tuft becomes trapped beneath row guide 120 , it remains trapped until it is eventually sheared off by a slotted razor blade 130 . Due to variations in manufacturing, individual carpet tufts frequently encroach the area between rows of tufts where the cushion back cutter needs to pass. As a result, carpet tufts can be run over and can become trapped by row guide 120 and inadvertently sheared off. If carpet tufts are sheared off by the blade, this will result in gaps in the tufts at the seam. This can produce an unsightly seam, particularly on patterned carpet.
[0012] It would therefore be desirable to have some means to prevent carpet tufts from becoming trapped beneath the row guide, which could reduce shearing off of the carpet tufts and thereby produce better looking seams.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a prior art cushion back cutter.
[0014] FIG. 2 illustrates a slotted razor blade usable in a cushion back cutter, such as the prior art cushion back cutter shown in FIG. 1 .
[0015] FIG. 3 illustrates an exploded view of the prior art cushion back cutter of FIG. 1 .
[0016] FIG. 4 illustrates a side view of a cushion back cutter, in accordance with an embodiment of the invention.
[0017] FIG. 5 illustrates an exploded view of the cushion back cutter of FIG. 4 .
[0018] FIG. 6 illustrates a side view of the cushion back cutter of FIG. 4 , with the slotted razor blade 1030 extended.
[0019] FIG. 7 illustrates an alternative embodiment of a center plate 2060 for use with the cushion back cutter of FIG. 4 .
[0020] FIG. 8 illustrates a front view of a prior art cushion back cutter inserted between two rows of carpet tufts.
[0021] FIG. 9 illustrates a side view of a cushion back cutter, in accordance with another embodiment of the invention.
[0022] FIG. 10 illustrates an exploded view of the cushion back cutter of FIG. 9 .
[0023] The figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION
[0024] As shown in FIG. 4 , cushion back cutter 1000 has a body 1010 , a row separator 1015 , a row guide 1020 , a blade holding pocket 1025 , and a handle 1080 . At least one slotted razor blade 1030 can be inserted into blade holding pocket 1025 , though blade holding pocket 1025 may be formed wider to accept two or three blades. In addition, cushion back cutter 1000 includes a blade clamp 1040 and a blade clamp thumbscrew 1050 . Blade clamp thumbscrew 1050 is offset or fastened “outside the perimeter” of slotted razor blade 1030 , and need not pass through the central slot 1034 of slotted razor blade 1030 .
[0025] To install blades, blade clamp thumbscrew 1050 need only be loosened a few turns, without having to be removed, which in turn loosens blade clamp 1040 . Afterwards, slotted razor blades 1030 can be inserted into the bottom opening of blade holding pocket 1025 . As slotted razor blades 1030 are inserted further into blade holding pocket 1025 , they easily slide beneath blade clamp 1040 . When a desired depth of cut is set, blade clamp 1040 can be tightened down on an outside surface of a slotted razor blade 1030 by re-tightening blade clamp thumbscrew 1050 , and all blades will be held at their desired positions.
[0026] Blade clamp 1040 presses on an outer surface of a slotted razor blade 1030 to hold it in position. As a result, the depth of cut of slotted razor blade 1030 is not limited by the blade clamp screw 1050 hanging up on an upper end 1035 of central slot 1034 . As shown in FIG. 6 , when installed in cushion back cutter 1000 , slotted razor blade 1030 can be clamped into position with its bottom corner extended further from row guide 1020 . This results in a depth of cut D that is greater than depth of cut C of the prior art cushion back cutter 100 shown in FIG. 1 . This allows cushion back cutter 1000 to cut through carpets with thicker backings, or even to double cut two overlapping pieces of carpet, as is sometimes necessary.
[0027] As shown in FIG. 4 , cushion back cutter 1000 also has a row guide 1020 with a series of notches 1021 . Notches 1021 are rounded in shape and continuous along a portion of row guide 1020 . Notches 1020 allow carpet tufts (which may become trapped beneath row guide 1020 ) the opportunity to escape from beneath the row guide 1020 before being cut. In particular, the carpet tufts have an opportunity to stand up into their natural position if temporarily released from downward pressure by the relief provided by any of notches 1021 . Furthermore, notches 1021 tend to push any trapped carpet tufts aside as they pass by or across the tufts. Thus, in two different ways, notches 1021 act to reduce the problem of carpet tufts becoming trapped beneath the row guide 1020 and eventually being sheared off by a slotted razor blade 1030 .
[0028] In one embodiment, the notches have a depth that is greater than the thickness of a carpet tuft for which the cutter is designed. For example, the notches may have a depth of at least 0.100 inches. In another embodiment, the notches have a continuous contour to avoid trapping any carpet tufts.
[0029] Row guide 1020 , in addition to having notches 1021 , also includes a bevel 1022 formed on its bottommost surface. Both the notched area formed by notches 1021 as well as straight area 1023 of row guide 1020 have this bevel 1022 . Bevel 1022 helps row guide 1020 including notches 1021 and straight area 1023 penetrate as deeply as possible into the tight area between two lines of carpet tufts and to pass through this area smoothly.
[0030] The beveled straight area 1023 of row guide 1020 establishes the final part between the left and right lines of carpet tufts after notches 1021 have cleared as many carpet tufts as possible. This ensures that the parted carpet tufts will not re-enter the area directly in front of slotted razor blade 1030 and as a result be sheared off.
[0031] FIG. 5 shows the exploded view of cushion back cutter 1000 , which includes a left side plate 1150 , a center plate 1160 , and a right side plate 1170 , all of which are spot welded together to form a body 1010 . Center plate 1160 includes a slot 1162 , which provides space to form blade holding pocket 1025 in the middle of the cutter to receive slotted razor blades 1030 . Left side plate 1150 and right side plate 1170 form the left and right walls of blade holding pocket 1025 . Center plate 1160 additionally includes a row guide 1161 , notches 1163 , and a bottom bevel 1165 formed on notches 1163 and continuing all the way to slot 1162 . Left side plate 1150 includes a blade window 1154 and blade window graduations 1156 , both to assist in setting the depth of cut of slotted razor blades 1030 . Left side plate 1150 additionally includes a blade clamp opening 1157 and a blade clamp screw passage hole 1158 , which is positioned outside the perimeter of the position of blades 1030 once they are inserted into blade holding pocket 1025 . Center plate 1160 has a blade clamp screw passage hole 1168 in a position corresponding with blade clamp screw passage hole 1158 of left side plate 1150 . Right side plate 1170 also includes a nut forming a blade screw tapped hole 1178 spot welded to its outer surface in a position corresponding with blade clamp screw passage hole 1158 of left side plate 1150 .
[0032] Blade clamp 1040 includes an upper portion 1041 with a blade clamp screw passage hole 1042 and an offset bottom portion 1043 that steps down from upper portion 1041 . Bottom portion 1043 of blade clamp 1040 is insertable into blade clamp opening 1157 of left side plate 1150 . Blade clamp thumbscrew 1050 is inserted through blade clamp screw passage hole 1042 of blade clamp 1040 , through blade clamp screw passage hole 1158 of left side plate 1150 , through blade clamp screw passage hole 1168 of center plate 1160 , and threaded into a nut forming blade screw tapped hole 1178 that is spot welded onto an outer surface of right side plate 1170 . When blade clamp thumbscrew 1050 is tightened down onto upper portion 1041 of blade clamp 1040 , the lower portion 1043 is pressed against slotted razor blades 1030 to hold them in their desired positions.
[0033] FIG. 7 shows center plate 2060 , which is an alternative embodiment of the center plate 1160 shown in FIG. 5 . Center plate 2060 includes an upper portion 2061 and a lower portion 2062 . Upper portion 2061 and lower portion 2062 can be spot welded with left side plate 1150 and right side plate 1170 (both shown in FIG. 5 ) to produce a body similar to body 1010 of FIG. 4 . However, lower portion 2062 can be processed separately from upper portion 2061 in automated industrial processes, such as batch de-burring. Such processes can produce bending in a part shaped like the center plate 1160 of FIG. 5 , making it unable to be spot welded. This is because the center plate 1160 of FIG. 5 has a large area removed at slot 1162 , which makes it prone to being bent by such processes.
[0034] Alternative embodiments of cushion back cutters, and other types of carpet seam cutters that include a row guide, may include notches on the row guide to reduce shearing of carpet tufts. FIG. 9 shows cushion back cutter 2000 , which is an alternative embodiment of the cushion back cutter 1000 of FIG. 4 . Cushion back cutter 2000 includes front pocket 2010 and rear pocket 2020 for holding two slotted razor blades 2030 . As shown in FIG. 10 , space for slotted razor blades 2030 is created by machining a front pocket 2015 in the left (back) side and a rear pocket 2025 in the right (front) side of center plate 2060 . When left side plate 2050 and right side plate 2070 are positioned in relation to center plate 2060 , front blade pocket 2010 and rear blade pocket 2020 are formed for holding slotted blades 2030 . Thus, slotted razor blades 2030 slide into cushion back cutter 2000 and are held in a cutting position by the perimeter defined by front pocket 2015 and rear pocket 2025 . Center plate 2060 additionally has notches 2061 , a straight area 2062 , and bottom bevel 2065 which form the row guide 2120 of cushion back cutter 2000 .
[0035] In another embodiment, notches on a row guide such as those described above are used in connection with a carpet seam cutter, such as the one shown in U.S. Pat. No. 8,567,075B2 to Hetts et al., which is hereby incorporated by reference in its entirety. FIG. 4 of Hetts shows a loop pile cutter 20000 that includes a blade holder 21000 including a holder right side 21100 , a holder center 21300 , and a holder left side 21500 . Notches, a straight area, and a bottom bevel may be added to center 21300 to reduce shearing of carpet tufts.
[0036] The foregoing description of the embodiments of the invention has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure. Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
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A cushion back cutter is formed from a first side plate, a second side plate, and a center plate between the first and second side plates. The center plate includes a slot that forms a blade holding pocket with a bottom opening to receive one or more blades. A blade clamp is inserted into the blade clamp opening of the first side plate, and a blade clamp fastener tightens to cause the blade clamp to press the blades against the second side plate to hold the blades in position. The center side plate forms a row guide for guiding the blades of the cutter between adjacent rows of carpet tufts. The row guide may include a region having continuous notches, which tend to move the carpet tufts out of the path of the blades to avoid shearing them.
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FIELD OF THE INVENTION
The present invention relates generally to an emergency vehicle signal device for use in warning the public of the presence of an emergency vehicle in traffic and otherwise and, more particularly, improvements in and to warning light systems for use on emergency vehicles. Specifically, this invention is directed to an emergency vehicle signal device which is mounted in the interior of an emergency vehicle which, when activated, is visible outside the vehicle, but which is not readily apparent outside the vehicle when not activated, and further does not interfere with operation of the vehicle when the device is activated. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
BACKGROUND OF THE INVENTION
The use of emergency vehicle signal devices for increasing the visibility of public service vehicles is well known in the art. Vehicles using such devices include emergency, police, municipal, and construction vehicles, among others. The most widely employed type of visual warning system is the roof-mounted light bar. Such a light bar includes a plurality of light generators arranged on a support which spans from side-to-side, and either rests upon or is spaced above, the roof of the emergency vehicle, as set forth in the disclosures of U.S. Pat. Nos. 4,620,268 and 5,027,260. While such light bars accomplish the purpose of producing a wide variety of highly visible light radiation patterns to warn the public of the presence of the vehicle on which they are employed, prior art light bars possess certain inherent disadvantages. First, such prior light bars increase vehicle wind resistance and, correspondingly, increase fuel consumption due to the placement of the light bar on the roof of the emergency vehicle. Such placement interferes with the aerodynamic design of the vehicle. Further, at higher rates of speed, turbulence is created by a conventional light bar, thereby increasing the ambient noise level within the vehicle and having a negative effect on communications. Such turbulence also adversely affects the handling characteristics of the vehicle. A traditional light bar also increases vehicle height which may limit access to certain areas, or present the possibility of damage to property or the light bar itself where there is limited overhead clearance. Additionally, particularly in the context of law enforcement vehicles, the presence of a light bar conspicuously identifies the nature of the vehicle. Prior art light bars have been traditionally mounted on the roof of an emergency vehicle. Such a mounting configuration, however, requires that the exterior of the emergency vehicle be breached or defaced through the drilling of holes for purposes of fastening and wiring the light bar. When such roof-mounted light bars are removed from an emergency vehicle, such fastening or wiring holes require repair (i.e., patching and repainting) or reduce the value of the vehicle upon resale.
In an attempt to overcome the inherent disadvantages of roof-mounted light bars, alternative configurations have been accomplished through various combinations of grill or bumper-mounted warning lights, headlight flashers, warning lights mounted inside the vehicle on the dashboard, sun visors or rear vision mirror, and warning lights integrated with the externally-mounted rear view mirrors, such as disclosed in U.S. Pat. No. 5,660,457. These configurations hold some disadvantage, however, because such lights are located relatively close to the ground, and do not provide as effective a warning to the public as that afforded by conventional roof-mounted light bars. Further, with respect to warning lights placed inside the vehicle, vision at night has been problematic, due to refraction of the light into the interior of the vehicle, thereby interfering with the visibility of the operator. Another attempt at solving the disadvantages of roof-mounted light bar is set forth in U.S. Pat. No. 5,988,839, wherein an exterior, rear-facing light bar is described. The light bar of U.S. Pat. No. 5,988,839, however, is permanently affixed on the rear exterior of the vehicle, does not display a warning light to the front of the vehicle, and is not entirely inconspicuous when not in operation.
It may be appreciated that there is a continuing need for a new and improved emergency vehicle signal light visible from the front and/or rear of the emergency vehicle that possesses all of the advantages of prior art light bars without the disadvantages discussed above. None of the existing patented inventions nor known prior uses, whether taken singularly or in combination, disclose the specific details of the present invention in such a way as to bear upon the claims of the present invention to be disclosed herein.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of emergency vehicle signal devices now present in the prior art, the present invention provides an improved signal light mounted in the interior of an emergency vehicle. The general purpose of the present invention, which will be described subsequently in greater detail, is to provide an emergency vehicle signal device that is visible through a front and/or rear window of a vehicle which, through mounting in the interior of the emergency vehicle, has all of the advantages of the prior art and none of the disadvantages.
The signal device of the present invention comprises an internally-mounted light bar having a single tier array of individually-controllable, light generators which may be energized to create any desired illumination pattern. The light bar is mounted along the interior top edge of the front and/or rear windshield of the emergency vehicle. The light bar is mounted within a housing assembly which attaches along one edge to the headliner or interior roof of the vehicle with the opposing edge of the housing extending to and along the contour of the windshield glass. The housing operates to shield the interior of the vehicle from refraction of the signaling device when energized, and provides a finished appearance when viewed from the interior of the vehicle. The housing may also be fitted with various storage compartments and/or other equipment (e.g., radar devices, cameras) for use by operators of the vehicle. Use of the housing for this additional purpose reduces the possibility of such equipment being placed on the dashboard of the vehicle and becoming projectiles during high-speed operation or collision, and increases visibility for the operator of the vehicle.
In the typical installation, the emergency signal device in accordance with the present invention will be mounted entirely within the interior of the vehicle through the use of a housing fastened to the headliner of the vehicle extending to the front and/or rear windshields. When installed, the emergency vehicle signal device will not be visible from the exterior of the vehicle, will not adversely affect the aerodynamics of the vehicle, will not decrease the visibility of occupants inside the vehicle, yet when energized, will possess all of the advantages of a roof-mounted light bar without refraction of the light into the interior of the emergency vehicle, particularly at night.
According to a further aspect of the invention, the present invention may be easily installed in existing emergency vehicles, or may be installed during manufacture of such a vehicle. The signal device of the present invention can also be easily removed upon resale of the emergency vehicle or for the purpose of installing varying light configurations (e.g., lenses of red, blue, amber, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the emergency vehicle signal device;
FIG. 2 is a cross-sectional view along line 2 — 2 showing placement of the signaling device in the interior of an emergency vehicle at the intersection of the roof of the vehicle and the front or rear windshield;
FIG. 3 is a perspective view of the emergency vehicle signaling device installed in the front interior of an emergency vehicle; and
FIG. 4 is a perspective view of an alternative embodiment of the emergency signaling device installed in the front interior of an emergency vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring specifically to the drawings, the interior-mounted emergency vehicle signal device will be disclosed.
The present invention is suited for use with any vehicle having an interior (i.e., a car or truck rather than motorcycle). FIG. 1 shows the signal device comprising a housing ( 5 ) having a vertical planar member ( 10 ), said vertical planar member ( 10 ) having a front face ( 12 ), a back face ( 14 ), and a top edge ( 15 ). Said housing ( 5 ) is further comprised of a horizontal planar member ( 55 ) having a leading edge ( 60 ), a trailing edge ( 62 ), a top surface ( 57 ), and a bottom surface ( 58 ), said leading edge ( 60 ) having attached thereto a gripping means ( 61 ), such as a rubber bumper or a plurality of rubber cylinders. Vertical planar member ( 10 ) is attached to trailing edge ( 62 ) of horizontal planar member ( 55 ) along the front face ( 12 ) opposite top edge ( 15 ), forming a 90° angle between vertical planar member ( 10 ) and horizontal planar member ( 55 ), thereby forming a generally L-shaped shelf. A single tier of a plurality of light generators ( 20 ) having base members ( 30 ) well-known in the art are attached at base members ( 30 ) to the front face ( 12 ) of vertical planar member ( 10 ) of housing ( 5 ) using fastening means ( 35 ). The plurality of light generators ( 20 ) is electrically connected to the power supply of the vehicle by wires ( 40 ) and circuitry (not shown) which are well-known and understood by those skilled in the art. A plurality of attachment means ( 45 ) extend from back face ( 14 ) of vertical planar member ( 10 ) along top edge ( 15 ). Attachment means ( 45 ) may be common L-shaped brackets well-known in the art. In an alternative embodiment of the signal device, attachment means ( 45 ) may also include an integral mounting flange ( 100 ) extending along top edge ( 15 ) and protruding therefrom at a 90° angle, as depicted in FIG. 4 .
FIG. 2 is a cross-sectional view illustrating the means by which the present signal device is attached to the interior of a vehicle having a roof ( 75 ), headliner ( 80 ), and windshield ( 65 ) having an interior surface ( 70 ). Said roof ( 75 ) abuts windshield ( 65 ) at joint ( 85 ) which is comprised most commonly of a rubber sealing means well-known in the automotive industry. Housing ( 5 ) of the present invention is mounted to the interior of a vehicle through use of fastening means ( 50 ) which fasten attachment means ( 45 ) to headliner ( 80 ). Housing ( 5 ) is preferably placed to maximize exterior illumination by light generators ( 20 ) so that front face ( 12 ) of vertical planar member ( 10 ) is vertically aligned with joint ( 85 ). Such placement of housing ( 5 ) allows horizontal planar member ( 55 ) to extend to windshield ( 65 ) so that leading edge ( 60 ) abuts interior surface ( 70 ) at gripping means ( 61 ), thereby shielding the interior of the vehicle from refracted light emitted from light generators ( 20 ) during operation. Gripping means ( 61 ) acts to prevent movement between windshield ( 65 ) and horizontal planar member ( 55 ). Top surface ( 57 ) of horizontal planar member ( 55 ) may preferably be coated with any number of reflective materials well-known in the art.
FIG. 3 illustrates placement of the present invention as viewed through the front windshield of a vehicle. The present invention is mounted entirely within the interior of a vehicle.
Alternative embodiments of the present signal device invention include any number of lens colors or illumination patterns for light generators ( 20 ). A further embodiment of the signal device, as shown in FIG. 4, includes the attachment of a storage compartment ( 102 ) and equipment such as a radar device ( 104 ) and a camera ( 106 ) to bottom surface ( 58 ) of horizontal planar member ( 55 ) of housing ( 5 ).
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
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An emergency vehicle signal device mounted in the interior of a vehicle which, when activated, is visible outside the vehicle, but which is not readily apparent outside the vehicle when not in operation. The signal device does not interfere with the operation of the vehicle when activated, and does not affect the aerodynamics, handling, or overhead clearance of the vehicle.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/941,488 filed Jun. 1, 2007.
FIELD OF THE INVENTION
[0002] The embodiments of the present invention relate to a playing card vault for use in casino environments.
BACKGROUND
[0003] Card shuffling machines are well-known in the art and have been used for decades to randomly and automatically arrange playing cards. Card shoes and discard trays or racks are also well-known in the art and have been used for decades to hold cards proximate a dealer so that the cards may be dealt to players and used cards may be stored out of the way, respectively. There are also card verifying machines which are used to verify decks of cards including the rank and suit of cards forming one or more decks.
[0004] Despite the numerous electronic devices now involved with card shuffling and dealing, there are times when cards are being needlessly handled by casino personnel. Such card handling opens up opportunity for collusion between dealers and players and inadvertent mishandling of the cards.
[0005] Therefore, it would be advantageous to utilize a card holding device or vault for maintaining cards at all critical times except during the dealing process. In addition, the card vault should be universal in its ability to attach to various of the currently available card handling devices.
SUMMARY
[0006] Accordingly, a first embodiment of the present invention is a card vault comprising: four sides and a bottom defining a space adapted to receive a plurality of playing cards; an adjustable door configured to cover and expose an opening opposite the bottom; and one or more locking mechanisms adjacent to said defined space wherein said one or more locking mechanisms are configured to removably attach said card vault to at least one of the following: an automatic card shuffling machine; a card shoe; a card verifying machine; and a card discard rack. In another embodiment, the card vault includes an identification tag such as a RFID tag for tracking the location and movements of the card vault and contained cards at all times.
[0007] A card tracking system of the present invention comprises: a card vault adapted to attach to at least one of the following: an automatic card shuffling machine; a card shoe; a card verifying machine; and a card discard rack; and means for tracking a location of said card vault. Another card tracking system of the present invention comprises: a card vault adapted to attach to at least one of the following: an automatic card shuffling machine; a card shoe; a card verifying machine; and a card discard rack; and means for recording data associated with said card vault.
[0008] Other variations, embodiments and features of the present invention will become evident from the following detailed description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a perspective view of one embodiment of a card vault of the present invention;
[0010] FIG. 2 illustrates a side view of one embodiment of the card vault of the present invention attached to an automatic card shuffling machine;
[0011] FIG. 3 illustrates a side view of one embodiment of the card vault of the present invention attached to a card shoe;
[0012] FIG. 4 illustrates a front view of one embodiment of the card vault of the present invention attached to a card verifier;
[0013] FIG. 5 illustrates a side view of one embodiment of the card vault of the present invention attached to a discard rack; and
DETAILED DESCRIPTION
[0014] For the purposes of promoting an understanding of the principles in accordance with the embodiments of the present invention, reference will now be made to the embodiments 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. Any alterations and further modifications of the inventive feature illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed.
[0015] Reference is now made to the figures wherein like parts are referred to by like numerals throughout. FIG. 1 shows a perspective view of a card vault generally referred to by reference numeral 100 . The rectangular card vault 100 includes two long walls 110 , two short walls 120 and a bottom 130 (collectively a housing) defining a card storage space 140 . An adjustable door 150 conceals the card storage space 140 and any cards therein. In one embodiment, the door 150 is slidably joined to the card vault 100 via grooves 155 along inner surfaces of the long walls 110 . Universal locking mechanisms 160 are integrated on the card vault 100 adjacent to the card storage space 140 . The locking mechanisms 160 may be integrated on any or all walls of the card vault 100 and may number one or more. The locking mechanisms 160 may be magnets, clips, snaps, ribs, clamps, latches, fasteners, hooks, grips or any other suitable means for attaching the card vault 100 to one or more card handling devices. As detailed below, the universal locking mechanisms 160 are used to removably attach the card vault 100 to multiple card devices, including electronic card devices. Optionally, a tracking device 170 , like a RFID transmitter or tag, may be connected to the card vault 100 to allow the location of the card vault 100 to be tracked by a RFID receiver.
[0016] FIG. 2 shows the card vault 100 attached to a card shuffler 180 . The locking mechanisms 160 of the card vault 100 engage a side edge 190 of the automatic card shuffling machine 180 . Alternatively, locking mechanisms (not shown) adjacent to the side edge 190 of the automatic card shuffling machine 200 mate with the locking mechanisms 160 of the card vault 100 . As cards are shuffled they are ejected into the attached card vault 100 . The card vault is then sealed and transported to a card shoe 210 (shown in FIG. 3 ). The tracking device 170 can then be activated to allow the location of the card vault 100 , and importantly the cards therewithin, to be tracked within a casino environment via one or more terminals, hand-held devices or similar means incorporating receivers or transceivers configured to receive signals from said tracking device 170 . The received signals are then interpreted to determine a substantially real-time location of the card vault 100 . Alternatively, the tracking device 170 may be activated at all times such that it intermittently sends a tracking signal to allow the location and movements of the card vault 100 and contained cards to be tracked via one or more terminals, hand-held devices or similar means.
[0017] Now referring to FIG. 3 , the card vault 100 is shown attached to a card shoe 210 . The universal locking mechanisms 160 of the card vault 100 engage an upper surface or edge 220 of the card shoe 210 . Alternatively, locking mechanisms (not shown) adjacent to the upper surface of edge 220 of the card shoe 210 mate with the locking mechanisms 160 of the card vault 100 . Cards 230 in the card vault 100 fall into the card shoe 210 as the door 150 to the card vault 100 is slid open.
[0018] FIG. 4 shows the card vault 100 attached to a card discard rack 240 . The card discard rack 240 is positioned on a card table and used to deposit cards which have been played in a hand by players and a dealer. The universal locking mechanisms 160 of the card vault 100 attach to the discard rack 240 so that as cards are placed therein the cards fall directly into the card vault 100 . In one embodiment, the discard rack or tray 240 rests flush on the gaming table and the card vault 100 hangs thereover. Supports (not shown) on the subject gaming table provide a place for the card vault 100 to rest. Optionally, the discards can be placed directly into the card vault 100 that is positioned on the card table. Thereafter, the card vault 100 is sealed for transport to the casino's backroom where the process is repeated or the cards are destroyed or prepared for sale. During the transport to the casino's backroom, the tracking device 170 can be activated to allow the location of the card vault 100 to be tracked. Alternatively, the tracking device 170 may be activated at all times such that it intermittently sends a tracking signal to allow the location and movements of the card vault 100 and contained cards to be tracked.
[0019] FIG. 5 shows the card vault 100 attached to a card verifying device 250 like the Deckchecker manufactured and sold by the present applicant. The Deckchecker verifies the integrity of card decks. More particularly, the Deckchecker counts the number of cards and determines the rank and suit of each card it receives. As shown, the card vault 100 is attached to a side, output portion of the card verifying device 250 . So, as the cards are verified, the cards are output into the card vault 100 . The card vault 100 may be attached to the card verifying device 250 after the shuffling process or after the cards have been used in play or both.
[0020] Advantageously, use of the card vault 100 limits human contact with the cards to game play thereby minimizing collusion or inadvertent mishandling of the cards. Also, with the tracking device 170 integrated on the card vault 100 , the location of the cards may be tracked in substantially real-time throughout a casino environment at nearly all times. The universal locking mechanisms 160 allow a single card vault design to engage an automatic card shuffling machine, card shoe, card discard rack and card verifying machine.
[0021] In one practical example the card vault 100 is attached to the output section of the automatic card shuffling machine 180 such that cards are shuffled into the card vault 100 . Shuffle data and a card vault ID, location, date and time are reported to a tracking system. Such reporting may be triggered automatically by the attachment of the card vault 100 to the card handling device. Alternatively, the reporting may be manually triggered by the casino personnel causing the attachment such as, for example, pressing a signal button on the card vault 100 or card shuffling machine 180 . In such an embodiment, the card vault 100 may include a processor, storage device, power supply, user interface 101 and display 102 . Casino personnel may then utilize the user interface to input or record data such as shuffle data and a card vault ID, location, date and time. The data can then be sent by a transmitter to a system receiver. The cards may be verified by a card verifier (e.g., Deckchecker) or the automatic card shuffling machine 180 may integrate such capabilities. The verifying data may also be reported to the tracking system as described above. The card vault 100 is then sealed. A seal may also incorporate a RFID tag or similar device. The shuffling and verifying of the cards takes place in a casino backroom or other designated area. The sealed card vault 100 is then transported to a designated gaming table. The movement of the sealed card vault 100 is tracked from the backroom to the gaming table. At the gaming table, the card vault 100 is unsealed and attached directly to the card shoe 210 . At this time, the card vault ID is reported to the tracking system as set forth above. The same or a separate card vault is attached to the card discard rack 240 . In one embodiment, the card shoe 210 includes an electronic reader for identifying the cards as they are removed from the card shoe 210 . After the cards have been used to play game, they are placed into the card discard rack 240 which may also include an electronic reader for once again verifying the played cards. Once the cards from the card shoe 210 are exhausted or played to a cut card, the card vault attached to the card discard rack 240 , which contains all the played cards, is removed and sealed. The card vault ID, location, date and time are reported to the tracking system as set forth above. The sealed vault holding the played cards is then returned to the backroom so the cards may again go through the cycle. If the cards are sufficiently worn, they may be destroyed or prepared for sale to casino patrons.
[0022] The tracking system may be a local area wireless network which communicates with the casino management system or other casino systems. In one embodiment, one or more user terminals having displays allow casino personnel to locate all card vaults in substantially real-time. Hand-held devices with displays may also be used to locate the card vaults. A storage device integrated into the tracking system also maintains a record of the location of each card and a corresponding time stamp. The tracking procedure may take many forms including the use of transmitters and receivers (or transceivers), RFID technology or GPS technology.
[0023] In another embodiment, the card vault 100 includes a card retention and release mechanism designed to hold the cards in the card vault 100 until the card vault 100 is connected to a card handling device (e.g., automatic card shuffling device). A card retention and release mechanism may comprise a spring-biased arm which contacts one end of the card stack contained in the card vault 100 thereby retaining the cards 230 in the card vault 100 via pressure. Upon connecting the card vault 100 to the card handling device, the spring-biased arm is released mechanically and/or electronically allowing the cards to release into the card handling device. The release may be manually or automatically triggered. Other retention and release mechanisms can be used.
[0024] Although the invention has been described in detail with reference to several embodiments, additional variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
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A card vault for attachment to an automatic card shuffling machine, card shoe, card verifying machine and card discard rack is disclosed. The card vault facilitates a system of reducing human handling of cards thereby reducing human error and cheating. Cards may be transferred in a card vault directly from the card verifying machine to an automatic card shuffling machine. After being dealt during one or more table games, the cards are placed in a discard rack and transferred to the card vault for transport to a card verifying machine where the deck is verified. The card vault and contained cards are tracked in substantially real-time using wireless technology such as a RFID transmitter and receiver.
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BACKGROUND OF THE INVENTION
Typical hook drive mechanisms which are known in the art may be of the belt driven type which are illustrated in U.S. Pat. Nos. 3,382,826 and 3,476,067 each of which is assigned to the assignee of the subject invention. As illustrated in each of these patents, the hook and its driving mechanism are usually firmly secured together as by pins or screws or the like and the interconnection between the elements comprising the drive mechanism can be somewhat complicated. Further, removal of the hook from its associated drive mechanism in order to take the hook out of the sewing machine, if necessary, may become somewhat of a time consuming task because of the manner in which the hooks are supported in the sewing machine with the associated mechanism of the hook and the bed portion of the sewing machine frame. As will be apparent hereandafter, it is a purpose of the present invention to provide a relatively simple hook drive mechanism in which the hook and bobbin may be easily and readily removable from the machine and further in which the drive mechanism to the hook is relatively simple as viewed from its manufacturing, assembly and hook timing aspects.
GENERAL DESCRIPTION OF THE INVENTION
The invention is generally carried out by providing a hook support plate which is removably secured in the bed portion of the sewing machine and is provided with a bearing support means which may be in the form of an upstanding bushing for receiving the hook and a hook drive member. The hook and the hook drive member are freely supported in the bearing means for easy removal therefrom and for rotation with respect to the bearing means. The hook drive member is provided with an upstanding dog portion which is disposed for mating engagement with a slot in the body of the hook member. The hook drive member is also provided with a sprocket to which is connected a timing belt driven by a suitable power source so that driving motion is transmitted from the hook drive member through the dog to the hook member itself. A cover plate is disposed over the hook member and supported by the hook support plate and carries a movable hook retaining means. The retaining means is pivotally supported on the cover plate and engages the bobbin case which is disposed in the body of the hook member and when in restraining position maintains the hook member in driving engagement with the hook drive member and thereby restrains the hook member from vertical movement with respect to the hook support plate. Also supported on the hook support plate is an idler pulley support plate having an idler pulley carried thereby for engagement with one side of the timing belt to maintain tension thereon. The idler pulley support plate is adjustable relative to the hook support plate and further is supported by the hook plate for movement therewith such that when the hook support plate, which may be pivoted with respect to the frame portion of the machine, is pivoted for adjusting the hook point-to-needle relationship will move with the hook support plate in a manner to maintain tension on the timing belt. Accordingly, it is one object of the invention to provide a novel and improved hook drive mechanism wherein the hook member is readily removable from the hook drive assembly and is relatively easy to manufacture, assemble and to maintain the elements in timed relationship during operation thereof.
Other objects and advantages of the invention will be best understood on reading the following detailed description with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is an axial sectional view of a portion of a sewing machine illustrating the invention therein;
FIG. 2 is a top plan view of a portion of the bed portion of the sewing machine taken along line 2--2 of FIG. 1; and
FIG. 3 is an exploded perspective view showing the elements of the combination of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a portion of a sewing machine 10 is illustrated therein as including a bed portion 12 having an upstanding standard 14 extending therefrom which interconnects with an overhanging arm portion (not shown) which in turn terminates in a head portion 16 containing a reciprocating needle mechanism 18 including the needle 20. As is well known in the sewing machine art, an electric motor or the like may be provided for imparting drive power to the machine which electric motor is generally connected to a main shaft in the arm portion of the machine with a crank mechanism being connected thereto for reciprocating the needle in its up and down relationship with respect to the bed portion of the machine to carry a thread through a fabric in the sewing operation. Supported within the bed portion 12 is a vertical axis rotary hook 22 having a hook point or beak 24 for seizing a loop of thread thrown out by the needle 20 during its penetration of the fabric and carries the thread around a thread carrying bobbin (not shown) which is contained within a bobbin case 26 supported in the body of the hook 22 such that the needle thread is concatenated with the bobbin thread to form lockstitches in a well known manner. As is also usual practice in sewing machines, a feed mechanism is provided for feeding the fabric through the machine and includes a feed dog 28 which has a reciprocating motion for feeding the fabric across the surface of the bed portion so that continuous stitches may be made in the fabric. For purposes of convenience of illustration the drive mechanism for the feed dog 28 has been eliminated from the drawings but any suitable type of mechanism for driving the feed dog 28 may be provided.
Referring in particular to FIGS. 1 and 3, it will be seen that the hook member 22 further includes a cup-shaped body portion 30 with a bottom surface 32 and a depending pivot shaft portion 34 extending therefrom. In order to support the hook 22 in the machine according to the present invention, a hook support plate 36 having a circular aperture 38 is provided and accomodates a boss 40 extending upwardly from the interior bottom surface of the bed portion 12. Through this construction, the hook support plate 36 may be pivoted with respect to the boss 40 and bed portion 12 the purpose of which will be more fully explained hereinafter. In order to lock or fix the hook support plate in position with respect to the bed portion 12, a threaded boss 42 is provided in the same surface of the bed portion 12 as the boss 40 but spaced therefrom for receiving a locking screw 44 through an aperture 46 in the hook support plate 36. Therefore, after adjustment of the hook support plate it may be locked in position by tightening down the screw 44 to the threaded boss 42. Adjacent one end of the hook support plate 36 is an upstanding bushing 48 which may be fixed to the hook support plate 36 by screws or the like or be formed intergal with the hook support plate 36. As best seen in FIGS. 1 and 3, the upstanding bushing 48 is adapted for freely receiving the shaft portion 34 of the hook 22 such that the hook may rotate freely with respect to the bushing 48 and may be readily removed therefrom.
In order to drive the hook member 22 in timed relationship to the reciprocation of the needle 20 for forming stitches, a hook drive member 50 is provided and includes a hollow shaft portion 52 whose outer peripheral surface may be formed as a sprocket and whose hollow portion is of sufficient size to pass over the outer peripheral surface of the upstanding bushing 48. The hook drive member 50 is therefore freely supported with respect to the bushing 48 and may freely rotate with respect thereto and is readily removable therefrom. As best shown in FIG. 3, the hook drive member 50 is also provided with an annular disc like top portion 54 having a dog or lug 56 extending from the top surface thereof. The dog 56 is formed so as to be accomodated in an aperture or slot 58 in the bottom portion 32 of the hook body 30. Thus when these elements are assembled, the dog portion 56 will be disposed in driving engagement with the hook 22 due to the relationship of the dog 56 in the slot 58 and any motion imparted to the drive member will also be imparted to the hook member. Rotary motion is imparted to the hook assembly from the motor and main shaft of the machine as through a vertically upstanding shaft 60 disposed in the standard portion 14 of the machine and interconnected with the main shaft as through gears or the like in a known manner. A sprocket 62 is carried by the shaft 60 and supports thereon a timing belt 64 which is also disposed in driving engagement with the sprocket formation on the shaft portion 52 of the hook drive member 50. Therefore rotary motion imparted to the shaft 60 will be transmitted by way of the timing belt 64 to the drive member 50 and to the hook 22 because of the interconnection of the hook drive member and a hook member as described above.
Referring in particular to FIGS. 2 and 3, an idler pulley 66 is provided for taking up any slack in the timing belt 64 and for maintaining tension thereon. The idler pulley 66 is supported on an idler support plate 68 which is carried on one end of the hook support plate 36 and is secured to the hook support plate 36 by means of a screw 70 threaded into the hook support plate 36 through an elongated slot 72 in the idler support plate. The idler support plate 68 is also formed with a locking finger 74 disposed in a slot 76 in the hook support plate 36 for holding the idler support plate at one end thereof during pivotal adjustment of the idler support plate 68 relative to the hook support plate 36. An elongated finger member 78 is disposed in abutting engagement with a rounded bump portion 80 on the hook support plate 36. The finger member 78 along with the idler support plate 68 is formed from a spring steel material so that when the idler support plate is adjusted relative to the hook support plate 36 by pivoting the idler support plate 68 about the pivot point formed by the finger 74, a spring tension will develop in the finger 78 due to its relationship with the bump portion 80 and thus maintain a spring tension relationship between the idler pulley 66 and the timing belt 64. Even when the proper adjustment of the idler support plate is made relative to the hook support plate by means of loosening fastening screw 70 and pivoting the plate 68, a limited amount of movement is possible about the screw 70 because of the relationship of the spring finger element 78 and the bump 80 which provides for a certain amount of give and return between the pulley 66 and the timing belt 64.
A hook mechanism cover plate 82 is provided (FIG. 3) which has for one purpose the maintainence of the components of the hook mechanism in the desired vertical relationship with one another. The hook mechanism cover plate 82 is supported in overlying engagement with the components of the hook mechanism by means of upstanding threaded bushings 84 and 86 extending from the top surface of the hook support plate 36 into which may be threaded screws 88 through suitable apertures positioned in the cover plate 82 for fastening the same to the hook support plate 36. Support posts such as those shown at 90 may also be provided on the cover plate 82 for supporting the cover plate on the hook plate 36 so as to prevent any undesirable rocking motion or other movement. As will be apparent from FIGS. 1 and 3, when the mechanism is assembled with the hook cover plate 82 supported on the bushings 84 and 86, the cover plate will overlie the bobbin case 26 the hook 22 and the drive member 50. A restraining means is provided such that when the elements are in the assembled condition described above, the hook member 22 will be maintained in driving relationship with the drive member 50. In otherwords, the restraining means prevents any vertical separation between the hook member 22 and the drive member 50.
As is also well known in the art, the hook 22 is rotatable relative to the bobbin case with its bobbin (not shown) so that the thread loop seized by the beak 24 of the hook 22 may be passed around the bobbin and the bobbin case for concatenation with the bobbin thread. Therefore, means are provided for maintaining the bobbin and its bobbin case stationary relative to the rotating hook member. As stated above, the bobbin case 26 is supported within the cup-shaped body portion 30 of the hook 22. In order to hold the bobbin case 26 stationary along with the bobbin, a restraining means is provided which includes a pivotal restraining member 92 which is pivotally supported on a fixed pin 94 at one end thereof which pin 94 may be suitably fixed or attached to a portion of the frame or other relatively stationary mechanism of the machine. The restraining member 92 has an abutment or cam surface 96 formed thereon which is positioned so that it will mate with a finger or camming element 98 on the bobbin case 26. A second cam surface 100 is also provided on the bobbin case 26 which is non-concentric with the inner surface of the hook body portion 30 so that rotation of the hook in a counter-clockwise direction as viewed in FIG. 3 will bring about a contact between the surface 100 of the bobbin case 26 and the inner surface of the hook body 30 while rotation in a clockwise direction will bring about an abutment between the cam surface 96 of the restraining member 92 in the cam finger 98 of the bobbin case. The bobbin case is also provided with an indentation 102 between the cam fingers 98 and 100 to permit passage of the needle therebetween for operative relationship with the hook beak 24. Thus it will be seen, that the bobbin case 26 will be restrained from rotation relative to the hook 22 during operation of the machine.
The restraining means also includes means for maintaining the hook 22 and drive member 50 in their vertical operative relationship. As best seen also in FIG. 3, the restraining member 92 also includes a forked finger member 104 disposed in overlying relationship with the bobbin case 26 and hook body 30. A latch member 106 is fixed to the underside of the cover plate 82 by a set screw 108 and is formed of spring steel so that it will bear down against the restraining member 92. A pair of spaced lugs 110 are provided on the upper surface of the restraining member 92 and are adapted for receiving a leg 112 of the latch member 106. When it is desired to maintain the hook member 22 and the drive member 50 in operative engagement, the latch member 106 may be lifted against its spring tension so that the restraining member 92 may be pivoted about the pivot pin 94 to bring the restraining member to an overlying position with respect to the hook and drive member and then the latch member may be released so that the leg 112 lies between the lugs 110 to lock the restraining member in the restraining position. As also shown in FIG. 3 a finger member 114 may be fixed to the underside of the cover plate 82 by a screw which finger member is positioned so as to lie between the forked end of the finger 104 of the restraining means 92. This serves to limit the rotation of the restraining member 92 and aid in supporting the same. Should it be desired to remove the bobbin and/or the bobbin case 26 during use of the machine, the latch member 106 may be lifted to pivot the finger 104 of the restraining member 92 in a counter-clockwise direction so that the finger 104 will be moved out of overlying engagement with the bobbin case and the hook body 30.
It will be further seen that the entire hook mechanism is readily removable from the machine for maintenance or repair or replacement of the hook 22, if desired. By removal of the screws 88 the top cover of the bed portion may be removed for easy access to the cover plate 82 and other mechanisms. The top cover plate 82 may be relatively easily lifted from the machine to provide access to the bobbin, hook 22 and drive member 50. Since these components are not fastened together by any means such as screws or the like and are freely supported with respect to one another the operator need merely lift each mechanism out. When replacing the components the drive member is slid over the outer surface of the bushing 48, the hook member is dropped through the bore in the center of the bushing 48 and the bobbin case and the bobbin are laid into the hook body 30. The cover plate 82 is then overlaid with respect to the other assembled components and the machine top cover placed thereon with the screws 88 being fastened into the threaded bore of the posts 84 and 86 to thus accomplish the complete reassembly of the hook drive mechanism.
It will also be seen that a relatively simple means is provided for adjusting the hook point-to-needle relationship. As is well known in the sewing art, it is important that the hook beak be properly positioned with respect to the path of needle travel so that the thread loop thrown out by the needle may be seized by the hook beak during its rotation thereof each time a thread loop is presented. Thus means must be provided for insuring that this relationship is properly adjusted and maintained. As briefly described above, the support plate 36 is supported with respect to the machine frame so that it may be pivoted for such adjustment. When it is desired to accomplish such adjustment, the screw 44 which secures the hook support plate 36 to the frame may be loosened and the entire support plate pivoted about the pivot point formed by boss 40 and aperture 38 in the hook support plate 36. When the proper position is reached the screw 44 is tightened into the boss 42 to lock the hook support plate in the properly adjusted position. During such adjustment of the hook support plate and the hook 22 with respect to the needle 20, because of the relationship of the idler pulley support plate on the hook support plate 36, the adjustment of the hook point-to-needle need not affect the pressure of the idler pulley 66 on the timing belt 64.
From the above detailed description of a preferred embodiment of the invention it will be seen that a novel hook drive mechanism is provided which is readily accessible, easy to repair and maintain as well as adjust and is still relatively simple in construction. The components of the hook mechanism are freely supported with respect to each other and do not require any elaborate or critical fastening means to maintain the operative relationship with respect to one another. While the invention has been described in its preferred embodiment, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.
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This disclosure relates to hook drive mechanisms for sewing machines and in particular to a hook drive mechanism wherein the hook member is freely supported by a bearing means in a hook support plate carried by the bed portion of the frame and is driven by a likewise freely supported drive member. The support plate with the hook member is supported for relative adjustment with the needle for adjusting the hook point-to-needle relationship. The hook member is readily removable in that it is freely supported in the aforementioned bearing means and is otherwise only restrained by a movable restraining means carried by a hook member cover plate which when removed from restraining relationship permits the bobbin and the hook member to be easily lifted out from the machine. Further, means are carried on the hook support plate for adjusting and maintaining tension on a timing belt drive means for the hook mechanism.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an apparatus and method for preventing disbondment in a bonded foam insulated piping system of the type used for conveying high temperature fluids.
[0003] 2. Description of the Prior Art
[0004] Insulated pipelines are needed in a variety of situations. For example, distributed HVAC (heating, ventilation, and air conditioning) applications utilize chilled water for cooling and steam for heating. The chiller and boiler are typically contained in a central location and the chilled water and steam are distributed to other locations. For example, on a school campus the chiller and boiler may be located in a power plant building. The chilled water and steam are distributed to classrooms in separate buildings. A set of insulated pipelines is used to convey the chilled water from the chiller to other locations and back to the chiller. Another set of insulted pipelines is used to carry the steam from the boiler to the other locations and back to the boiler. Oftentimes, the temperature inside the pipe is either higher or lower than the ambient temperature surrounding the pipe. It is necessary for the pipes to be insulated in order to retain the internal temperature of the fluids and keep heating and cooling losses at a minimum. The insulated pipelines are usually located underground.
[0005] Insulated pipe of the type under consideration is conventional and commercially available. There are predominately two types of piping systems in use: Class-A drainable dryable testable (DDT); and polyurethane or polyisocyanurate bonded foam systems. The present application is directed toward the bonded foam type system. These systems utilize a steel pipe to convey fluid, and often the fluid is a different temperature as compared to the ambient environment. Around the outside of the steel pipe is a layer of insulating foam such as, for example, polyisocyanurate foam. In the case of high temperature piping systems, the insulating foam serves to keep heat loss from the starting location of the pipeline to the ending location at a minimum. Around the outside of the foam is a thin jacket of thermoplastic material, such as high density polyethylene (HDPE). The plastic jacket protects the foam from mechanical damage and also provides a watertight seal to prevent corrosion of the steel pipe. Although steel is commonly used for the inner pipe which carries the media to be piped, copper, aluminum or other metals as well as fiberglass, PVC, and similar materials may be utilized, as well.
[0006] The most important engineering criteria for a foam system of the type under consideration is that it must be treated as a bonded system. In other words, the foam is bonded to both the carrier pipe and the outer jacket. In such a case, the bonded system acts as a monolithic unit moving underground. Higher temperatures can act adversely upon the bonded foam system, however. The hot fluid in the steel carrier pipe causes the carrier pipe to thermally expand. At temperatures of 400° F. this expansion is on the order of 2.8 inches per 100 feet of pipe. This expansion is not a problem as long as the system remains bonded and the carrier pipe, foam and jacket move together as one unit underground. This movement is controlled by the expansion force of the steel carrier pipe, but it is the bond strength of the foam to the pipe and jacket that is important in keeping the system moving together. This monolithic movement of the system occurs along each incremental length of a particular run, and as long as total movement is not greater than 4 to 6 inches and the system remains bonded, no undue stress is subjected at any one point of the jacket. If the system were to disbond, however, the surrounding soil would fix the jacket in place and the carrier pipe would still thermally expand thereby pushing through and destroying the jacket at the first change of direction.
[0007] Generally speaking, the proper choice of insulating materials can counteract many of the thermal expansion effects discussed above. It has been well established by industry case history that the polyurethane foam bond for systems running at 250° F. to 300° F. is strong enough to keep the entire system acting as a bonded system. However, for systems running above these temperatures a higher temperature rated foam, such as polyisocyanurate foam, is generally required. Even in systems utilizing “high temperature” polyisocyanurate foam, the higher heat can, in some instances, begin to fry the foam at the foam/carrier pipe interface, thereby bringing into question the strength of the foam bond to the steel carrier pipe.
[0008] Various approaches have been taken to control this undesirable expansion in insulated pipe systems of the type under consideration. For example, expansion “bolster” materials are supplied in the form of resilient pads which can be used at elbows or expansion loops. These pads are placed adjacent to the piping and create a cushion which acts as a stress relief area in critical areas, such as angles and elbows.
[0009] Despite the advances seen in the high temperature piping industry, a need continues to exist for improved systems for preventing disbondment in bonded foam insulated piping systems.
[0010] A need also exists for such an improved system which utilizes many of the conventionally available materials and manufacturing techniques commonly used in the industry.
[0011] A need also exists for such a system which is simple in design and economical to implement.
SUMMARY OF THE INVENTION
[0012] The method and apparatus of the present invention provide an improved insulated piping system for conveying high temperature fluids. The insulated piping system has a first and second length of insulated and jacketed pipe, each having a joining end to be joined to an end of the other length, and each pipe length comprises an inner carrier pipe having an interior surface and an exterior surface. An envelope of foamed insulation surrounds the inner pipe exterior surface, and an outer protective jacket surrounds the envelope of insulation. The joining ends of adjacent pipe lengths are welded together to form fixed joints, whereby the adjacent pipe lengths provide a continuous length of fluid conduit for conveying high temperature fluids.
[0013] In addition, a discrete length of an external slip wrap is placed at a selected location along the length of the piping system, generally in a location at which the piping encounters an angular change of direction, such as at an elbow or expansion loop. The slip wrap comprises a loosely received outer sleeve for the piping which surrounds the outer protective jacket without being bonded thereto, whereby the insulated and jacketed pipe can move axially relative to the slip wrap for a selected distance once the pipe is buried in the ground. Preferably, the external slip wrap is a thin sleeve formed of a flexible plastic type material, such as a polyolefin material having characteristic coefficient of friction which allows the jacketed pipe to slide within the sleeve. In one preferred form of the invention, the external slip wrap may be formed of polyethylene.
[0014] The location of the slip wrap along the length of piping is selected to in order to prevent disbondment of the foam insulation from the inner carrier pipe. Prevention of disbondment is possible by allowing relative movement of the pipeline relative to the surrounding earth, thereby eliminating the separation of the envelope of foamed insulation from the exterior surface of the inner metal pipes as the temperature of the inner metal pipes increase and the pipeline expands. In a typical case, the lengths of insulated piping are part of a pipeline conveying steam, hot water or other hot fluids at a temperature in the range of above about 200° F.
[0015] Additional objects, features and advantages will be apparent in the written description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a simplified representation of a typical distributed HVAC system utilizing chilled water for cooling and steam for heating.
[0017] FIG. 2 is a schematic representation of an expansion loop in a pre-insulated pipeline prior to thermal expansion.
[0018] FIG. 3 is a schematic view of the pipeline of FIG. 2 under the influence of thermal expansion forces.
[0019] FIG. 4 is a simplified side view of a bonded foam insulated pipe showing the inner carrier pipe, surrounding layer of foam, and outer polyolefin jacket and showing the external slip wrap of the present invention surrounding the polyolefin jacket.
[0020] FIG. 5 is an end view, partly in section, of an underground bonded foam insulated pipe showing the external slip wrap of the present invention surrounding the pipe at a selected location along the length thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Turning first to FIGS. 1-3 , there is illustrated a typical environment in which the pre-insulated piping systems of the invention might be employed. FIG. 1 shows a school campus having a number of isolated buildings 31 , 33 connected by an underground insulated pipeline 35 carrying steam which at points includes right angle loops or elbows 37 . The U-shaped bend 37 is provided for the purpose of allowing the pipe to expand and contract without producing an unacceptable level of stress in the pipe, pipe fittings, or attachment points for the pipe.
[0022] FIGS. 2 and 3 are schematic views of the standard piping installation of the type under consideration designated generally as 39 . The installation 39 includes a number of coaxially oriented lengths of pipe, such as length 55 (shown broken away in FIG. 2 ). The installation may also include a number of angled fittings such as the right angle elbows (generally shown as 41 ) in FIG. 2 . Each length of pipe includes an inner pipe 11 , typically formed of steel, an envelope of foamed insulation 15 surrounding the inner pipe and outer protective jacket 13 surrounding the envelope of insulation. The joining ends of adjacent pipe lengths are affixed, as by being welded together, to form fixed joints, whereby the adjacent pipe lengths provide a continuous fluid conduit for conveying high temperature fluids. The jacket 13 ( FIG. 1 ) is typically formed of high density polyethylene (HDPE) or a similar polyolefin type material. The following references, among others, teach the manufacture of such prior art systems: U.S. Pat. No. 3,793,411; U.S. Pat. No. 4,084,842; and U.S. Pat. No. 4,221,405, all to Stonitsch et al.
[0023] The piping systems of the type illustrated in FIGS. 2 and 3 are sometimes utilized to convey fluids at high temperature and/or pressures. For example, a typical steam line might be conveying fluid at, for example, 400° F. The temperature differentials which exists between the piping system materials and the fluid being conveyed can cause a force (“F” in FIG. 2 ) to be applied along the coaxially aligned pipes lengths. As mentioned earlier, these U-shaped bends 39 in a piping system are provided for the purpose of allowing the pipe to expand and contract without producing an unacceptable level of stress in the pipe, pipe fittings, or attachment points for the pipe. However, the greatest amount of stress in the pipe is located just prior to the first angle in the expansion loop, shown generally at 43 in FIG. 3 .
[0024] In the piping system illustrated in FIG. 2 , the longitudinal runs of pipe in the system are displacing as a unit and moving axially in the surrounding soil. This movement does not damage the jacketing or the foam of the system because they are both incrementally being pulled along throughout the entire length of the straight run. Because of this monolithic movement no one individual section of the jacket is over stressed and thereby ruptured, and no one individual section of the foam is required to support the entire force of the thermal expansion of the pipe. The bond distributes these forces along each incremental length of the entire run. It will be understood, however, that should the forces become great enough, disbondment of the foam from the carrier pipe can occur. If the carrier is free to move independently from the foam and jacket (disbondment has occurred) then the surrounding soil will fix the jacket in place and the carrier pipe will burst through the foam and jacket in areas shown generally as 43 in FIG. 3 . Failure of the surrounding insulated layers allows water or other contaminants to contact the steel pipe, leading to increased corrosion and joint failure in some cases.
[0025] The present invention is intended to provide a solution for possible disbondment problems for foam bonded piping systems that are operating at temperatures generally above about 200° F. At temperatures that begin to exceed 250° F., foams have been developed that are stable structurally to handle these higher temperatures, but the bond strength of the foams at these temperatures may come into question. The invention is intended to prevent the potential problems that might occur if the foam bond strength is not sufficient to cause the systems to expand as one monolithic item.
[0026] The reference in this discussion to pipe “lengths” is intended to refer to standard available factory pre-insulated piping of the type previously described having an inner metal pipe surrounded by an envelope of foamed insulation, which in turn, is contained within a polyolefin jacket. As referred to briefly above, typical commercial practice involves the use of steel, copper, aluminum or alloy conveying pipes, open or closed cell polyurethane, polyisocyanurate, polystyrene or the like, foamed rigid insulation and polypropylene, polybutylene, polyethylene, polyvinylchloride and similar protective jackets.
[0027] The present invention is an improvement to presently available pre-insulated piping of the type which is commercially available and familiar to those in the relevant industries. Prior art pipe lengths of this general type are commercially available as standard factory type product. For example, such products are available from Thermacor Process, LP of Fort Worth, Tex., assignee of the present invention. One typical example is sold commercially as the HT-406 High Temp Steel Piping System. The published specifications for systems are as follows:
[0000]
Carrier Pipe-
diameter less than about 2″
A53 ERW Grade B, Std. Wt.
Black Steel
diameter greater than about 2″
A106 SML, Std. Wt. Black
Steel
HDPE Jacket-
Compatible with ASTM D3350
Specific Gravity (ASTM D792)
0.941 min.
Tensile Strength (ASTM D638)
3100 psi min.
Elongation Ultimate (ASTM D638)
400% min.
Compressive Strength (ASTM
2700 psi min.
D695)
Impact Strength (ASTM D256)
2.0 ft. lb/in. North Min.
Rockwell Hardness (ASTM D785)
D60 (Shore) min.
Polyisocyanurate Insulation-
Density
>2.4 lbs/ft 3
“K” Factor
≦0.14 @ 70° F., ≦0.24 @ 406° F.
Compressive Strength
>30 psi
Closed Cell Content
≧90%
Minimum Thickness
≧2.5″ @ 366° F., ≧3.0″ @ 406° F.
[0028] The present invention addresses the problem of foam disbondment by helping insure that the inner carrier pipe and outer layer of bonded foam continue to move as a unit as the inner pipe expands. This object is accomplished by providing an “external slip wrap” which surrounds the outer protective jacket of the piping system at selected locations. The external slip wrap is a sleeve formed of a flexible polyolefin material having a desired characteristic coefficient of friction. Since the external wrap is not bonded to the protective jacket, the insulated and jacketed pipe can move axially relative to the slip wrap in the earth for a selected distance once the pipe is buried in the ground. It is important to note, the external slip wrap is not intended to further insulate or waterproof the piping system, as that is already handled by the foam and outer protective jacket respectively. Instead, the function of the external slip wrap is to allow movement of the insulated pipe by providing a slidable environment that normally would not exist when the surrounding earth is holding the protective jacket in place.
[0029] The external slip wrap of the invention is designated generally as 17 in FIG. 5 . The wrap 17 is intended to be used in any coaxially aligned piping system of the type previously described and has particular application where the lengths encounter an angular bend or turn, such as the elbow 41 ( FIG. 2 ). The slip wrap 17 is particularly advantageous in countering the harmful effects of coaxial stresses which are often encountered in a “high temperature” insulated piping system. The term “high temperature” is intended to encompass any temperature above ambient which would tend to cause the type of damage to the surrounding insulating layers of the piping system discussed with respect to FIGS. 1-3 above. Typically, such temperatures will be above about 200° F., and in some cases temperatures of 400° and higher will be encountered.
[0030] The preferred external slip wrap 17 of the invention is a thin sleeve formed of a flexible material, such as a suitable polyethylene material. As shown in FIG. 4 , it fits as a sleeve around the protective jacket 13 of the pipeline 35 and is typically installed at a location which precedes a turn in a U-shaped expansion loop 37 in the piping system. As has been described, each pipe length comprises an inner pipe 11 , an envelope of foamed insulation 15 surrounding the inner pipe and an outer protective jacket 13 surrounding the envelope of insulation. In the particular embodiment of the invention illustrated in FIG. 5 , the surrounding foam insulation layers 15 are typically polyurethane closed cell foam insulation for systems of up to about 250° F. and polyisocyanurate foam insulation for systems above 250° F. The surrounding jacket 13 is a polyolefin, preferably HDPE. The pipe lengths 11 can be standard factory type product of the kind described above and available from Thermacor Process, LP of Fort Worth, Tex.
[0031] FIG. 5 is intended to be a simplified view of what the external slip wrap would look like in position at a selected location surrounding the insulated pipeline with a layer of earth surrounding the complete assembly. Note that the force of the earth generally compresses the polyethylene sleeve 17 downwardly onto the top and bottom of the pipeline (generally at 13 ).
[0032] In the particular system illustrated in FIGS. 4 and 5 , the external slip wrap 17 surrounds the inner pipe 11 for about six feet prior to the first angle in the expansion loop in the pipe system. The greatest amount of stress is now thought to occur at the location immediately before the U-shaped expansion loop 37 , as shown by location 43 . The pressure force “F” causes the pipeline to bend inwardly, as drawn in phantom in FIG. 3 . Disbondment of the foam insulation 15 from the inner carrier pipe 11 may occur in some situations.
[0033] However, because the external slip wrap allows the insulated and jacketed pipe to move axially relative to the wrap for a selected distance once the pipe is buried in the ground, the outer jacket remains intact and the integrity of the foam insulation is not disrupted. Since the insulating layer remains intact, water or other contaminants are prevented from reaching the inner steel pipe, thereby extending the useful life of the pipeline.
[0034] An invention has been provided with several advantages. The external slip wrap of the invention alleviates problems previously encountered with high temperature piping systems where elbows and other angled fittings caused the pipe to be subjected to damaging stresses. The system incorporates several existing, commercially available materials or components, thereby simplifying manufacture and assembly. The particular application of the slip wrap of the system compensates for relative movement of the inner steel pipe which could disrupt the continuity of the surrounding insulating layer at an elbow or other fitting. The coupling is simple in design and economical to implement in a variety of industrial applications.
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The present invention relates generally to an apparatus and method for preventing disbondment in an insulated piping system that is used for conveying high temperature fluids. More specifically, an external slip wrap is shown, capable of surrounding the outer protective jacket of the insulated piping system at a location along the piping before an elbow shaped or angular change in direction. The slip wrap comprises a loosely received outer sleeve which surrounds the outer protective jacket of the piping without being bonded thereto, thereby allowing the insulated and jacketed pipe to move axially relative to the slip wrap for a selected distance once the pipe is buried in the ground.
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BACKGROUND OF THE INVENTION
The present invention relates to an automatic telephone answering apparatus.
Conventionally, automatic telephone answering apparatuses have magnetic tape as message recording means. An incoming message recording tape and an outgoing message prerecorded tape are alternately or simultaneously used to playback a prerecorded outgoing message to a caller and/or to record an incoming message on the incoming message recording tape for a subscriber. The present inventor has previously developed an apparatus in which a unit for generating a Morse signal is used in place of the outgoing message tape so as to deliver the Morse signal instead of an outgoing message prerecorded on the tape. The above apparatus is granted as U.S. Pat. No. 4,058,679. Along with the development of electronic techniques, an IC such as a CMOS-IC has been made commercially available which has a very low current consumption in the standby mode. Therefore, it is possible to carry an automatic telephone answering apparatus and a compact tape recorder connected thereto together in a user's pocket. Furthermore, telephone line connections are modified and simplified such that a modular plug is inserted in a corresponding jack. If a user wishes to use the automatic telephone answering apparatus having the compact tape recorder connected thereto in, for example, a hotel room during a trip, he can use the apparatus with dry cells without using an AC outlet. However, in the conventional apparatus using the incoming message recording tape and the outgoing message prerecorded tape, current consumption is large. Therefore, it is not appropriate to market a portable apparatus of the conventional type since the required capacity of the dry cells is large.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a convenient automatic telephone answering apparatus wherein a speech synthesizer such as a voice synthesizer is used for a message, which apparatus holds current consumption to less than several microamperes in the standby mode and to less than several tens of milliamperes in the operation mode, thereby allowing the use of dry cells and a modular plug plugged into a modular jack at any time, for example, in a hotel room during a trip.
It is a second object of the present invention to provide an automatic telephone answering apparatus incorporating a speech synthesizer, which apparatus may be operated to record a voice of a caller by connecting an external tape recorder thereto.
It is a third object of the present invention to provide an automatic telephone answering apparatus incorporating a speech synthesizer, which apparatus stores a plurality of types of messages to deliver a first message when a call is received, to simultaneously record a caller's voice on an external tape recorder, and to deliver a second message after a predetermined time interval has elapsed, terminate the call.
It is a fourth object of the present invention to provide an automatic telephone answering apparatus wherein the second message is delivered when the incoming call is received and when a tape end detection signal is also received, thereby restoring the automatic telephone answering apparatus to the standby mode.
It is a fifth object of the present invention to provide an automatic telephone answering apparatus wherein a third message is delivered for subsequent calls after the magnetic tape of the external tape recorder has reached its end to disable subsequent recording, thereby restoring the automatic telephone answering apparatus to the standby mode.
It is a sixth object of the present invention to provide an automatic telephone answering apparatus wherein the third message alone is delivered in response to an incoming call when the external tape recorder is not connected to or is removed from the automatic telephone answering apparatus, thereby restoring the automatic telephone answering apparatus to the standby mode.
In order to achieve the above objects of the present invention, there is provided an automatic telephone answering apparatus having a relay means which is operated to be self-held upon receipt of a telephone call, which remains self-held during the call, and which is then released when the caller hangs up the receiver, and a momentary release circuit which is operated in response to a signal upon termination of the call, wherein a loop circuit is formed upon operation of the relay means to selectively read out a proper message from among a plurality of types of messages from a speech synthesizer and to deliver it to the caller in accordance with whether or not the external tape recorder is connected, the magnetic tape on the external tape recorder has reached its end, or the predetermined time interval has elapsed since the incoming call was received, thereby releasing the relay means and restoring the automatic telephone answering apparatus to the standby mode. Since the speech synthesizer such as a voice synthesizer is used, the automatic telephone answering apparatus according to the present invention does not involve magnetic tape and drive mechanisms therefor, unlike the conventional automatic telephone answering apparatus, thus resulting in simple construction and compactness. Furthermore, according to the present invention, a mechanism for vertically moving a head to select one of various messages need not be used for the apparatus. START and BUSY terminals of the voice synthesizer are coupled to logic circuits, so that various messages corresponding to A1, A2, A3, . . . , and so on can be produced either singly or in a combination thereof when recording of the caller's voice is completed, when the magnetic tape for recording the caller's voice reaches its end, and when a response alone is required. Furthermore, even when the magnetic tape on the external tape recorder reaches its end, and even when the tape recorder is removed from the automatic telephone answering apparatus, the automatic telephone answering apparatus can still respond to the caller, thus resulting in convenience in a variety of applications.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1(a) and 1(b) of the drawing are a circuit diagram of an automatic telephone answering apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawing shows the main part of an automatic telephone answering apparatus according to an embodiment of the present invention. Reference symbol A denotes a control part; and B, a tape recorder connected to the control part A. Reference symbols L1 and L2 denote telephone line terminals, respectively. Reference symbol LT denotes a line transformer. A neon lamp NE and a light-receiving element Cds constitute a photocoupler for detecting a call signal. A ringing amplifier 1 produces a signal of high level for about 2 seconds after one to three call signals are supplied thereto. Reference numeral 2 denotes a speech synthesizer composed of IC or LSI. Reference symbols A1, A2 and A3 denote terminals for accessing addresses of the synthesizer; CS, a chip select terminal for enabling the speech synthesizer 2; and START, a terminal which causes a terminal OUT to produce synthesized speech after one of the addresses respectively corresponding to the terminals A1, A2 and A3 is accessed and the corresponding terminal goes high. For example, when the address corresponding to the terminal A1 is accessed, a message "Please leave your message" is produced from the terminal OUT. When the address corresponding to the terminal A2 is accessed, a "hang up" message "Thank you" is produced. When the address corresponding to the terminal A3 is accessed, a "response only" message "Please call again. We are absent now" is produced.
During the above output operation, a terminal BUSY is kept high. Reference symbol G-6 denotes an AND gate; G-7, an inverter; and G-8 and G-9, AND gates, respectively. These gates are used to switch the addresses corresponding to the terminals A1, A2 and A3. An amplifier 3 amplifies the synthesized speech or message. A relay Y-1 has four contacts y1-1 to y1-4 and is started in response to the call signal. A delay circuit 4 is started when the contact y1-3 is closed. The delay circuit 4 provides a one-second delay. A timer 5 is started when the contact y1-3 is closed. The timer 5 can be adjusted in a range of 20 to 60 seconds. A transistor TR-1 for a momentary release detection circuit detects that the caller hangs up the receiver while the timer 5 is in operation. A transistor TR-4 for a determination switching circuit is kept OFF when an incoming message recording tape on the external tape recorder B to be described in detail later has reached its end, or when the external tape recorder B is not connected to the automatic telephone answering apparatus.
In the tape recorder B, reference numeral 10 denotes a built-in microphone; 11, a preamplifier; 12, a main amplifier; and 13, a speaker. Reference symbol M denotes a motor; BAT, a power source; and SW1-1 and SW1-2, manually operated switches for performing rewinding, playback and so on. The arrangement of the tape recorder B is known to those who are skilled in the art, and is thus simplified. However, in order to record the caller's voice by connecting the tape recorder B to the control part A, the tape recorder B must, of course, be set in the recording mode. It is noted that reference symbol SW2 denotes an automatic release switch when magnetic tape (not shown) reaches its end. It is also noted that the recording tape B and the control part A are connected through a plug P-1 and a jack J-1, through P-2 and J-2, and through P-3 and J-3.
The mode of operation of the automatic telephone answering apparatus having the arrangement described above will now be described hereinafter. Assume that the control part A and the tape recorder B are connected to each other and that an incoming message recording tape (not shown) has not reached its end. In this condition, a call signal is transmitted to the telephone line terminals L1 and L2, the call signal is detected by the ringing amplifier 1 through the photocoupler comprising the neon lamp NE and the light-receiving element Cds. After two or three call signals are applied to the ringing amplifier 1, the ringing amplifier 1 produces a signal of high level since the call signal is delayed by a delay circuit (not shown) having a capacitor and a resistor therein. This signal is supplied to transistors TR2 and TR3 through diodes D3 and D2 respectively, so that the transistors TR2 and TR3 are both turned ON. The relay Y-1 is then biased to close its contacts y1-1 to y1-4. When the contact y1-1 is closed, a loop circuit is formed through the primary winding of the line transformer LT. Therefore, the bell stops ringing. Since the contact y1-3 is also closed, a positive voltage from a power source +B is applied to the delay circuit 4. When one second has elapsed, the output of the delay circuit 4 goes high. The signal of high level is supplied through an inverter G-11 to the chip select terminal CS which goes low, thus rendering the speech synthesizer 2 operative. Before the chip select terminal CS goes low, the output of the delay circuit 4 is low. A signal of high level has been supplied in advance to the terminal START through pins b and c of a NOR gate G-10. Therefore, as described above, when the terminal CS goes low, a synthesized message which corresponds to one of the addresses respectively accessed at the terminals A1, A2 and A3 is produced from the terminal OUT. In the speech synthesizer IC according to the present invention, even if a signal of high level is supplied to the terminal START after the chip select terminal CS goes low, the synthesized message is produced. Further, since the contact y1-4 is closed, pins a and b of the plug P-2 are short-circuited, and hence pins a and b of the jack J-2 of the tape recorder B are short-circuited. The positive voltage from the power source BAT is applied across the motor M through the switch SW1-1, so that an incoming message recording tape (not shown) is driven. At the same time, the positive voltage from the power source BAT is applied to one end of a resistor R13 through the jack J-2 and the plug P-2, so that the transistor TR-4 is ON. The collector of the transistor TR-4 thus goes low. The signal of low level from the collector is supplied to a pin b of the AND gate G-8, and to a pin b of the AND gate G-6 through the inverter G-7. The pin a of the AND gate G-6 and the pin a of the AND gate G-8 are connected to the output end of the ringing amplifier 1. Even if the bell stops ringing, the output of the ringing amplifier 1 is held high for about 2 seconds until the charge on a capacitor (not shown) of the delay circuit in the ringing amplifier 1 is discharged. As is apparent from the figure, the pins a and b of the AND gates G-6 simultaneously go high. A pin c of the AND gate G-6 then goes high. Therefore, the terminal A1 of the speech synthesizer 2 goes high, whereas the terminals A2 and A3 thereof go low. The synthesized message "Please leave your message" which corresponds to the terminal A1 is produced from the terminal OUT. This synthesized message is then amplified by the amplifier 3 and is delivered to the caller through the line transformer LT.
As described above, when the output of the inverter G-11 goes low, a pin b of a NOR gate G-4 goes low, whereas a pin c thereof goes high. The signal of high level from the pin c of the NOR gate G-4 is supplied to the base of the transistor TR2 through a resistor R-8. The base of the transistor TR-3 is biased through a resistor R7, as described above. Therefore, even if the output signal from the ringing amplifier 1 goes low in about two seconds after the loop circuit is formed to stop producing the audible ringing signal from the ringing amplifier 1, the relay Y-1 remains held.
As described above, a caller's message received after the synthesized message corresponding to the address terminal A1 is produced is transmitted through the line transformer LT, a resistor R3, the plug P-1 and the jack J-1, and the preamplifier 11, and is recorded by a known recording circuit (not shown) on the incoming message recording tape. When the caller hangs up the receiver before the timer 5 is OFF, a momentary release pulse which is generated at the time when the caller hangs up the receiver is applied to the transistor TR-1 through the line transformer LT. While the momentary release pulse is applied to the transistor TR-1, the transistor TR-1 remains ON. Upon the ON condition of the transistor TR-1, a pin a of a NAND gate G-2 goes high through an inverter G-1. At this time, since no synthesized message is produced by the speech synthesizer 2, the terminal BUSY is kept low, and a pin b of the NAND gate G-2 is kept high through an inverter G-3. Therefore, a pin c of the NAND gate G-2 goes low. A bias voltage applied to the base of the transistor TR-3 through the contact y1-2 and a resistor R7 is cut off, so that the transistor TR-3 is turned OFF. As a result, the relay Y-1 is released and the automatic telephone answering apparatus is restored to the standby mode.
However, when the caller continues to talk even after the timer 5 is OFF (e.g., even after 30 seconds have elapsed), the terminal A2 of the speech synthesizer 2 goes high. A synthesized "hang up" message "Thank you" corresponding to the terminal A2 is produced from the terminal OUT. In this case, as may be apparent from the above description, since the output of the ringing amplifier 1 is already low, and the pins a of the AND gates G-6 and G-8 are both low, the pins c thereof go low. Pins a and b of the NAND gate G-9 go low, whereas a pin c thereof goes high. The terminal A2 of the speech synthesizer 2 then goes high. In this condition, when the timer 5 is turned off, the output of the timer 5 goes high, and the output of an inverter G-12 goes low. It is noted that a pin a of the NOR gate G-10 instantaneously goes low in response to a negative pulse from a capacitor C5. A pulse of high level is supplied from the pin c of the NOR gate G-10 to the terminal START of the speech synthesizer 2. The synthesized "hang up" message corresponding to the terminal A2 is produced so as to signal completion of the recording operation to the caller. Furthermore, the relay Y-1 is actuated to properly produce the whole synthesized message. When the timer 5 is OFF, a pin a of a NAND gate G-5 goes low, as is apparent from the above description. Meanwhile, during the time in which the "hang up" message is produced, the terminal BUSY of the speech synthesizer 2 goes high. When this signal of high level is applied to a pin b of the NAND gate G-5, a pin c of the NAND gate G-5 goes low, a pin a of the NOR gate G-4 goes low, and the pin c of the NOR gate G-4 goes high. The signal of high level from the NOR gate G-4 is applied to the base of the transistor TR-2 through the resistor R8. Thus, the relay Y-1 is actuated. However, when the "hang up" message is produced and the terminal BUSY goes low, the pins a and b of the NAND gate G-5 both go low, the pin c of the NAND gate G-5 goes high, the pin a of the NOR gate G-4 goes high, and the pin c of the NOR gate G-4 goes low. The bias voltage applied to the base of the transistor TR-2 is then cut off, so that the relay Y-1 is released and the automatic telephone answering apparatus is restored to the standby mode.
When an incoming message recording tape (not shown) mounted on the tape recorder B and set in the recording mode reaches its end, the automatic telephone answering apparatus is restored to the standby mode after the "hang up" message corresponding to the terminal A2 is produced. Thereafter, the "response only" message corresponding to the terminal A3 is produced for subsequent calls. More particularly, when the magnetic tape reaches its end during recording, the automatic release switch SW2 is opened. As may be apparent from the above description, since no voltage is then applied to one end of the resistor R13 through the jack J-2 and the plug P-2, the transistor TR-4 is OFF. The timer 5 is then rapidly charged through a resistor R12 and a diode D4, so that the timer 5 is forcibly turned OFF. In the same manner as the case in which the timer 5 is turned OFF as described above, the automatic telephone answering apparatus is restored to the standby mode after the "hang up" message corresponding to the terminal A2 is produced. In the reception of subsequent calls, immediately after the loop circuit is formed in response to the call signal, a voltage signal of high level is supplied from the transistor TR-4 to the pin b of the AND gate G-8 during which the output of the ringing amplifier 1 remains high for about 2 seconds, that is, during which the pins a of the AND gates G-6 and G-8 are kept high. The pin c of the AND gate G-8 goes high so that the address corresponding to the terminal A3 is accessed. In this condition, the terminal CS goes low through the delay circuit 4 and the inverter G-11. Since the START signal is already supplied in the manner as described above, the "response only" message corresponding to the terminal A3 is produced. Since the timer 5 is forcibly turned OFF by the diode D4, the "response only" message "Please call again" is immediately produced in the same manner as in the case where the incoming message recording tape has reached its end. After this message is produced, the automatic telephone answering apparatus is restored to the standby mode. The above operation is then repeated every time an incoming call is received.
A case in which the external tape recorder B is not connected to the automatic telephone answering apparatus is the same as the case in which the incoming call is received after the incoming message recording tape reaches its end. After the "response only" message which corresponds to the terminal A3 is produced, the automatic telephone answering apparatus is restored to the standby mode. This operation is repeated every time an incoming call is received. More particularly, when the external tape recorder B is not connected to the automatic telephone answering apparatus and when an incoming call is received, the relay Y-1 is operated and its contact y1-4 is closed. However, the transistor TR-4 is OFF. The pin b of the AND gate G-8 goes high. Further, upon reception on an incoming call, the output from the ringing amplifier 1 renders the output of the AND gate G-8 high. Thus, the address corresponding to the terminal A3 is accessed. Further, since the contact y1-3 is closed, the terminal CS is already set to low, and the START signal is already supplied, the "response only" message corresponding to the terminal A3 of the speech synthesizer 2 is produced from the terminal OUT thereof.
In the embodiment described above, the terminal A3 of the speech synthesizer 2 is selected and the "response only" message is produced when the incoming message recording tape reaches its end or an external tape recorder is not connected to the apparatus. However, reception of a call may be inhibited when the incoming message recording tape reaches its end or an external tape recorder is not connected to the apparatus.
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The invention provides an automatic telephone answering apparatus wherein a relay means is operated upon reception of an incoming call so as to form a loop circuit, and a message from among a plurality of types of messages stored in a speech synthesizer is produced and delivered to a caller in accordance with the conditions whether or not a predetermined time interval has elapsed since the incoming call was received, whether or not an external tape recorder is connected, and whether or not an incoming message recording tape has reached its end.
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BACKGROUND OF THE INVENTION
This invention relates to the field of knit fabrics. More particularly it relates to the field of elastic warp knit fabrics and the method of making the same.
In the past a variety of elastic fabrics have been produced for use in the construction of foundation garments, swimwear and the like. These fabrics, for obvious reasons, must possess certain properties such as good bi-directional stretch, as well as vigorous recovery referred to as "power".
Widthwise stretch, is of particular importance since it permits the finished garment to stretch with the movement of the wearer and thereby prevents the garment from riding up, sliding or binding. Furthermore the need for a fabric having balanced stretch also arises in the construction of brassiers and other garments which require heat moldability since a balanced stretch fabric expands uniformly and therefore does not distort in the molding process.
U.S. Pat. No. 2,960,855 discloses an elastic fabric known in the textile trade as "power net". This fabric has substantially more stretch in the warp direction than in the width direction, due to the warp wise configuration of the elastic inlay threads.
Other fabrics, such as those disclosed in U.S. Pat. Nos. 3,064,885; 2,996,906 and 3,390,549 have obtained a balanced, bi-directional stretch by knitting the elastic threads with the inelastic threads. These fabrics, however, possess a number of substantial disadvantages in that they have a relatively high elastic yarn content. Also, in order to produce a fabric of normal weight using this technique it is necessary to use a fine denier elastic yarn, these yarns are quite costly thereby resulting in a fabric which is relatively expensive. Moreover, these fabrics have a tendency to curl, which makes the cutting and sewing of them difficult.
Another technique used for producing fabrics having balanced bi-directional stretch involves the laying in of elastic yarns in both the warp and weft direction. This technique may be accomplished, as would be understood by one skilled in the art, by the use of weft insertion equipment, wherein a continuous weft yarn is inserted across the fabric width. Although the presence of elastic threads in the warp and weft directions, impart to these fabrics balanced bi-directional stretch, the resulting fabric has a high percentage of elastic yarn and is quite difficult to knit, thereby substantially increasing the cost of the fabric.
Unlike the prior art fabrics discussed above, the fabric of the present invention is capable of balanced bi-directional stretch while consuming a minimum of elastic yarn without the need for expensive weft insertion equipment.
SUMMARY OF THE INVENTION
The present invention relates to an elastic knit fabric having two way balanced stretch. It comprises an inelastic ground structure in combination with an inlaid elastic thread. This inelastic ground structure is knitted using a six course repeating stitch comprising essentially a two step "Atlas" section followed by one course of chaining, another two course "Atlas" section and one course of chaining. The inlaid thread is held into the ground structure by means of floats within the ground structure.
Accordingly, it is an object of the present invention to provide a fabric which is capable of balanced bi-directional stretch suitable for use in foundation garments.
Another object of the invention is to provide a two way stretch fabric which has a low elastic yarn content.
A further object of the present invention is to provide a balanced bi-directional stretch fabric which is thin and compact so as to prevent foundation garment outline from showing through a wearer's outer garments.
Another object of the present invention is to provide a balanced bi-directional stretch fabric which will have good moldability properties.
Still another object of the present invention is a fabric which embodies all of the above mentioned properties while still being economical to produce.
Still other objects and advantages of the present invention will be obvious and in part be apparent from the specification and attached drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic illustration of the loop structure of a segment of the invented fabric.
FIG. 2 shows the stitch pattern of the present invention in a point diagram.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings the fabric of the present invention comprises essentially two yarns, an inelastic yarn which is knitted to form the ground structure and an elastic yarn which is laid into the ground structure to give the fabric its stretch characteristics.
Referring more particularly to the drawings, attention is first directed to FIG. 1 wherein three inelastic ground threads and one elastic inlay thread of the present fabric are shown. Thread, G1, G2 and G3 designate the inelastic ground threads which are knitted to form the ground structure of the fabric. Thread E designates the inlaid elastic thread.
To more particularly point out the novelty of the present fabric construction the path of only one thread G1 will be described in detail, since the paths of G2 and G3 are similarly knitted. It should be noted that the inelastic G threads are front-bar threads, and the E threads are back-bar threads.
As can be seen in FIG. 1 thread G1 forms loop 1 on course I in wale I. This loop, as would be understood by one skilled in the art, is a closed lap loop characterized by its crossed loop components at base 1'. After forming loop 1, thread G1 floats diagonally by means of float 1" to course II in wale II where it forms loop 2. As can be seen, loop 2 is an open lap loop in that its lower components are uncrossed at 2'. Thread G1 then proceeds to float diagonally to course III where it forms open lap loop 3 in wale III. It should be noted that this order of loop formation is called an "Atlas Traverse". Moreover, since loops 2 and 3 were formed in two steps, via floats 1" and 2", the traverse is designated a two step "Atlas".
On course IV, thread G1 does not traverse to the next wale but rather forms loop 4 directly above loop 3 on wale III, thereby causing float 3" to be almost vertically configurated. This vertical movement of thread G1 in forming a loop directly above the previous loop is called "pillar chaining" or simply chaining.
On course V, thread G1 traverses diagonally back to wale II by means of float 4 to form open lap loop 5. On course V1, G1 again traverses diagonally to the left to wale I via float 5 to form loop 6. On course VII thread G1 forms loop 7 directly above loop 6 in wale 1.
It can be seen from FIG. 1 that loop 7 is identical in configuration and wale location to loop 1, and from this point on the stitch pattern of thread G1 repeats itself on 6 course intervals. Therefore, the ground bar pattern or lapping movements may be said to consist of a two step diagonally traversing Atlas section, followed by one course of chaining followed by another two step diagonally traversing Atlas section in the opposite wale direction, followed by one course of chaining.
Elastic inlay thread E is held in the inelastic ground structure by floats such as 1", 2" and 3" as can be seen from FIG. 1. The number of such floats securing the inlay threads E are dependent upon the amplitude and direction of movement of thread E, i.e. the number of needle spaces traversed and whether thread E is moving in the same or opposite direction of the floats.
The number of floats holding the elastic inlay in the ground structure may be expressed as: N=Ng+d; wherein N is the number of floats holding the inlay, Ng is the effective length of the inlay traverse, expressed in needle spaces and d represents the direction of the float. If the elastic inlay is moving in the same direction as the inelastic ground float then d is represented as -1; if however the elastic inlay is moving in a direction opposite than that of the inelastic ground float then d is represented by +1. For example, referring again to FIG. 1 inlay thread E traverses across one needle space in the opposite direction as the floats in course 2, accordingly 1+1=2 floats, i.e. 2" and 2 2 .
As would be understood by one skilled in the art, this equation is valid only for single needle underlap fabric constructions. For example, the above equation would not apply on course 3, where the elastic inlay E is moved across two needle spaces, since no underlapping movement is performed by the inelastic threads G 1 or G 2 . However, it can be seen from an examination of FIG. 1 that the inlay thread E will be held in place by vertical floats 3" and 3 2 .
The fabric of the present invention exhibits a number of substantial advantages in its physical properties over similarly knitted prior art fabrics. For example, the fabric of the present invention possesses a high degree of width-wise stretch when compared to prior art fabrics which use a knit ground and elastic inlay construction. Such prior art fabrics, during finishing shrink only to approximately 80% of their knitting width making it difficult for them to develop a good width-wise stretch. The fabric of the present invention, on the other hand shrinks to approximately 50% of its knitting width, therefore permitting it to develop a greater amount of width-wise stretch when compared to similar prior art fabrics.
Another important property of stretch fabrics is their strain or load to elongation ratio which is used for judging the suitability of the fabrics for various end uses. It has been found that the fabric of the present invention has a load to elongation ratio or modulus which is far superior to those prior art fabrics using a knit ground and elastic inlay construction.
Furthermore, the fabric of the present invention gives a soft hand and a fabric surface as opposed to a net surface. Moreover, the fabric of the present invention is capable of a control type stretch in either direction as opposed to other fabrics which may give equal stretch in both directions but are only of a controlled type stretch in one direction, the other being a long comfort type stretch. Therefore, it is possible employing the fabric of the present invention to make certain garments using either direction around the body for control.
FIG. 1 is a schematic drawings of the loop structure of the present invention and does not depict the actual configuration of the elastic and inelastic loop components in the actual fabric. This is due to redistribution of the elastic inlay threads and distortion of the inelastic ground loops both of which are caused by the tension of the inlay thread.
FIG. 2 depicts the construction of the present fabric in a point diagram. As can be seen from the left hand side of FIG. 2 the front bar knits the inelastic ground construction in a manner which coincides with that of G1, G2 and G3 shown in FIG. 1. The movement of the back bar as shown on the right hand side of FIG. 2 lays in the elastic yarn in a manner which coincides with that of yarn E in FIG. 1. In the center of FIG. 2 the combined movements of both the back and front bars are shown. For the purpose of clarity, the lines depicting the shogged portion of the elastic thread E in the combined drawings of FIG. 2 have been depicted as being slightly inclined such that they do not merge with the lines representing the inelastic yarns.
In forming the fabric of the present invention, the following bar movements are used:
Bar 1 (front bar) 1-0, 1-2, 3-2, 2-3, 2-1, 0-1
Bar 2 (back Bar) 0-0, 2-2, 1-1, 3-3, 1-1, 2-2.
The above patterns are Tricot designations and can be readily converted to Raschel designations by those skilled in the art.
The bar movements depicted above designate a fabric having an open and closed loop construction for the front bar in the following sequence: closed, open, open, closed, open, open. As would be understood by one skilled in the art, this loop construction sequence of the inelastic yarn may be changed without destroying the fabric's superior physical characteristics; for example, the inelastic yarn may be knitted such that all the loops are closed or all the loops are open, alternately the loop construction may alternate between open and closed loops.
In another embodiment of the present invention the elastic inlay thread may be laid in using the following modified bar movement:
Bar 2 (back bar) 2-2, 1-1, 3-3, 1-1, 2-2, 0-0.
In the above description, the invention has been disclosed merely by way of example and in preferred manner; but many variations and modifications may and will be apparent to one skilled in the art while the resulting fabric will still remain within the general spirit of the invention, for example the front guide bar movement may be modified to form closed lap loops in lieu of open laps and vice versa.
It is to be understood, therefore, that the invention is not limited to any specific form or manner of practicing the same, except insofar as such limitations are specified in the claims.
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An elastic warp knit fabric having balanced bi-directional stretch is disclosed. The fabric comprising in combination an inelastic knitted ground structure and an elastic inlayed thread.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to video game control units. More particularly, the invention relates to control units for Atari * video games and to a lap board holder for such units which provides increased player comfort and control when operating the video game.
2. Description of the Prior Art
Video games have become immensely popular in the last few years; perhaps the most popular of several available games are those sold under the Atari trademark. Control units supplied with Atari games include those known as "joy stick" controls. In a joy stick control unit, a control rod (the "joy stick") extends generally perpendicularly from the top surface of a generally box-shaped housing, which is about 31/2 inches long, 37/8 inches wide and 11/2 inches high. In addition to the control rod, the top surface of an Atari joy stick control unit generally includes a control button. It should be understood that in this specification and the claims following, the term "box-shaped" means in the shape of a right rectangular prism.
In operating the joy stick controls, a player holds the housing in one hand, generally the left hand, in such manner that the control button can be activated by the thumb of that hand; the player uses his or her other hand to operate the joy stick itself--i.e., to move the control rod in various directions as necessary to play the particular game programmed into the unit.
A significant disadvantage of using the Atari joy stick control unit for extended periods of time, which is not uncommon, is that it often results in discomfort and even cramps in the player's hands, especially the hand holding the housing and operating the control button. Obviously, the game would be more relaxing and enjoyable if means could be found to eliminate the necessity of holding the housing in the player's hand while maintaining adequate control of the unit. To the best of my knowledge no such means have heretofore be available from either the video game art or any other area of the prior art. I have found that by mounting an Atari joy stick control unit in a suitable lap board holder as hereinafter described, the aforementioned problems with long-time use can be eliminated. Similar results can also be accomplished by providing a control unit which itself incorporates the features of my lap board holder.
SUMMARY OF THE INVENTION
In accordance with the invention I provide, for use with a video game control unit of the type wherein a control rod extends generally perpendicularly from the top surface of a generally box-shaped housing, which is up to about 6 inches long, up to about 6 inches wide, and up to about 3 inches high, a lap board holder comprising a rigid planar base having length at least sufficient to span and rest on the legs of a person operating the control unit while seated and width at least equal to the width of the housing, a rigid planar shelf having length exceeding the length of the control unit by an amount sufficient to provide support for at least one hand of a person operating the control unit and width at least equal to the width of the housing, the periphery of the shelf including a recess, and means joining the shelf to the base and positioning the shelf above the base in parallel spaced apart relationship such that the housing can be slid into position between the shelf and base and be held there by a tight fit with the control rod positioned in the recess in the shelf.
Preferably, the base and shelf are each of generally rectangular shape and the recess is formed in one of the longer sides of the shelf.
In a preferred embodiment the overall length and width of the base are 12 to 20 inches and 5 to 10 inches respectively.
In another preferred embodiment, the overall length and width of the shelf are 7 to 15 inches and 4 to 8 inches respectively.
In an embodiment especially adapted for the Atari joy stick control unit, I provide, for use with a video game control unit which includes (a) a generally box-shaped housing about 31/2 inches long, about 37/8 inches wide and about 11/2 inches high having top and bottom surfaces, left and right sides, a front and a rear; (b) a control rod extending generally perpendicularly from the center of the top surface; and (c) a control button on the top surface, a lap board holder comprising a rigid planar base of generally rectangular shape having length of 15 to 18 inches and width of 6 to 8 inches; a rigid planar shelf of generally rectangular shape having length of 7 to 10 inches, width of 4 to 6 inches, and a recess in one of the long sides; and means joining the shelf to the base and positioning the shelf about 11/2 inches above the base and parallel to the base whereby when the housing is slid into position between the base and shelf, it will be held in such position by a tight fit, wherein the recess is of such shape and size that when the housing is in position between the base and the shelf both the control rod and the control button are accessible to the hands of a person operating the control unit.
I may preferably provide a non-slip surface on the underside of the base of my lap board holder, whereby the holder will resist slipping when positioned on the legs of a person operating the unit.
I also provide a video game control unit comprising a housing in which a generally box-shaped body is positioned between and joined to a base and a top, both the base and the top being planar, rigid, generally rectangular, and at least as long and as wide as the body, and a control rod extending generally perpendicularly from the top of the housing, wherein the length of the base is at least sufficient to span and rest on the legs of a seated person operating the control unit, and the length of the top is sufficient to provide support for at least one hand of a person operating the control unit.
In my control unit, I prefer that the base be from about 12 to about 20 inches long and from about 5 to about 10 inches wide, and further that the top be from about 7 to about 15 inches long and from about 4 to about 8 inches wide.
As with my lap board holder, my control unit may have its underside provided with a non-slip surface, whereby the control unit will resist slipping when positioned on the legs of a seated person operating it.
Further details, objects and advantages of the invention will become apparent as the following description of certain present preferred embodiments thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings I have shown certain present preferred embodiments of the invention in which:
FIG. 1 is a top front three-quarter perspective view of my lap board holder;
FIG. 2 is a top rear three-quarter perspective view of my lap board holder with an Atari control unit in position therein; and
FIG. 3 is a top rear three-quarter perspective view of an alternative embodiment of the invention wherein the control unit itself is constructed to incorporate the essential features of the lap board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning first to FIGS. 1 and 2, wherein like numerals designate like features, it will be seen that my lap board holder includes a rigid planar base 10 and a rigid planar shelf 20, both of which are generally rectangular in shape. The preferred holder depicted in FIGS. 1 and 2 is especially adapted for use with the Atari joy stick control unit, which includes a generally box-shaped housing 40 having approximate dimensions of 31/2 inches long, 37/8 inches wide, and 11/2 inches high. In all the drawing figures, the directions for measuring length, width and height are shown by arrows L, W and H respectively.
With regard to the base 10, I have found that for best results it must be at least as wide as the housing 40 and at least long enough to span and rest upon the legs of a seated person operating the control unit. To meet these requirements the base of my holder is 5 to 10 inches, preferably 6 to 8 inches wide and 12 to 20 inches, preferably 15 to 18 inches long. The length and width can be greater than the broad ranges given, but above such ranges the holder becomes somewhat cumbersome. In one embodiment, I use a base which is about 7 inches wide and about 17 inches long. The height, or thickness, of the base 10 is at least great enough to make the base rigid, and as such depends on the material used for the base. Wood, plastic, metal or like materials may be used satisfactorily for the base; in the holder shown in FIGS. 1 and 2 I may use wood having thickness of 1/2 inch. The base may also include a hole 11 at one end for hanging the holder on, e.g., a nail when not in use.
The shelf 20 is dimensioned so as to be at least as wide as the housing 40 and long enough to support at least one hand of a person operating the control unit. I have found that widths of 4 to 8 inches, preferably 4 to 6 inches, and lengths of 7 to 15 inches, preferably 7 to 10 inches, are especially suitable for holders according to the invention, although dimensions exceeding such ranges could also be used satisfactorily. In one embodiment, the shelf is about 5 inches wide and about 73/4 inches long, which length both provides support for either hand of the player and allows gripping of the shelf. As with the base, the shelf may be formed from wood, plastic, metal or the like, so the height, or thickness required for rigidity will depend on the material chosen; I have found that lucite, plexiglass or other clear plastic having thickness of about 1/4 inch is especially desirable for the shelf.
The shelf 20 includes a recess 21 in one of its long sides. The recess is so shaped and sized that when the Atari control unit housing 40 is in place in the holder, as shown in FIG. 2, both the joy stick or control rod 41 and the control button 42 are accessible to the hands of a person operating the control unit. The edge of the recess may be beveled at the control button side, as shown at 22, to minimize irritation of the operator's thumb or finger when operating the button. I have found that the length from control button 42 to the shelf end 23 nearest the button should preferably be no more than about 23/4 inches; this allows most players to have the fingers of their hand around shelf end 23 and to reach control button 42 with their thumb without stretching.
Means, designated generally as 30, join the shelf 20 to the base 10 in parallel spaced apart relationship such that the housing 40 can be slid into position between the shelf and base and be held there by a tight fit with the shelf recess oriented as discussed above. In the embodiment shown in FIGS. 1 and 2, such means comprise a generally U-shaped member formed of 3/4 inch thick wood which, when the base and shelf are joined thereto, defines an interior cavity about 31/2 inches long, about 4 inches wide and of such height as to provide a tight fit for the housing when the housing is slid into the cavity. For the Atari joy stick control unit, I have found that a height of 11/2 inches between base and shelf is ordinarily suitable, but it will be understood that slight differences from such height may be necessary if the housing height varies from one control unit to another. The U-shaped joining means 30 may be fastened to the base 10 and shelf 20 by glue, screws, or similar fastening means. The rear wall of the joining member 30 includes a hole 31 through which a pencil or the like can be inserted to push the tightly fitting housing from the holder when removal of the housing is desired. It will be understood that joining means other than that shown in FIGS. 1 and 2 may be used to join the shelf to the base and to position the two members--for example, a series of screws or bolts and nuts could serve satisfactorily as joining means--so long as the above-discussed requirements of parallel spaced apart relationship between shelf and base and a tight fit for the control unit housing are met.
The lap board holder of FIGS. 1 and 2 is, as its name implies, primarily intended to rest on the legs of a seated person operating the video game; however, it can of course also be placed on a table or other flat surface. To minimize slipping of the holder when in use, whether on a player's lap or elsewhere, a non-slip surface 50, which may be foam rubber, carpeting or the like, is applied to the underside of the base 10.
To use the lap board holder, the control unit housing 40 is slid into position between shelf 20 and base 10. The player ordinarily positions the holder so that the open side of recess 21 is away from him or her, places the holder across his or her lap and operates the joy stick control rod 41 with the right hand and the control button 42 with the left thumb.
In FIG. 3 the novel features of the holder of FIGS. 1 and 2 have been incorporated into the video game control unit itself. This, of course, provides an alternative means of achieving the objects of the holder; whereas the holder of FIGS. 1 and 2 is useful to those who already have control units of existing designs, the unit of FIG. 3 is more appropriate as original equipment supplied with the video game.
The control unit of FIG. 3 includes a housing made up of base 60, a generally box-shaped body 70 and top 80. The shapes and dimensions of base 60 and top 80 are substantially the same as those of base 10 and shelf 20, respectively, of FIGS. 1 and 2. The unit shown in FIG. 3 is intended as a replacement for the Atari joy-stick control units available heretofore, and accordingly it includes control rod 90 extending from the top and control button 91 adjacent to the control rod. As with the lap board holder of FIGS. 1 and 2, the unit of FIG. 3 also includes a non-slip surface 61 applied to the underside of base 60.
Use of my lap board holder with the Atari joy stick control unit, or use of the control unit incorporating the essential features of the lap board holder, results in significantly less hand discomfort for persons playing the Atari video game, especially for extended periods of time; moreover, because of its stability and size my holder provides improved control of play by the operator.
While I have shown and described certain present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied within the scope of the following claims.
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A lap board holder is provided for use with a video game control unit such as that sold under the trademark Atari and commonly called a joy-stick control; the holder comprises a base which rests on the player's legs, a shelf on which the player can rest his or her hands, and structure joining the base and shelf in such manner that the control unit is held tightly between them. Also provided is a video game control unit which embodies the critical features of the lap board holder. The invention allows operation of the video game for extended time with improved control and greatly reduced hand and arm fatigue.
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PRIORITY/CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/723,904 filed Nov. 8, 2012, the disclosure of which is incorporated by reference.
BACKGROUND
Customarily when finishing drywall construction workers use various types of corner beads to finish the corners around doors, windows, and the edges of walls. These walls are typically framed in either 2″×6″ or 2″×4″ framings with half inch or ⅝″ drywall. Generally the drywall corner bead comprises a paper combined with metal corner, known as tape on corner bead and the metal and paper has a centerline with two metal flanges. Drywall corner bead can also be a metal corner that is fastened to the wall and mudded over. These flanges are fairly short and have an extended paper flange for attaching to a wall typically via joint compound (also known as mud). In this situation, typically the corner bead contains a recessed portion created along the two opposing flanges of the metal nose or point and a paper layer over the metal portion to allow for adhering to sheet rock. The recessed portion is prominent in the corner when the paper exterior sheet is present on the metal section, as is the case when the corner is applied in sheetrock finishing. This recessed portion allows for a worker to fill the recessed portion with mud, which is commonly known to those having experience in sheetrock/drywall application.
Customarily in dry wall applications, mud is applied with a trowel, a knife, or with the worker's hands or tools with similar function. The worker uses similar tools to smooth the mud and/or to remove excess mud. When the worker applies the corners disclosed in the previous art, the worker has to 1) apply mud to sheet rock surface with knife or with mud hopper, 2) press the corner firmly in place, 3) wipe paper edges of the corner bead to remove excess mud, 4) roll the corner into place with corner bead roller then remove excess mud, 5) allow mud layer to dry, 6) sand dried layer and apply an additional layer of mud and allow to dry, 7) sand dried layer and apply additional layer of mud and allow to dry. The worker must return sand and apply mud to areas needed per required finish. This mudding and sanding must be done before the worker can prime the wall for painting or texturing in order to generate a smooth corner. What is needed is a simple to apply corner that a worker does not have to repeatedly apply mud to, thus saving the worker time and material.
In tape on corner bead applications mud is applied to the sheetrock by hand using a drywall knife, trowel or mud application too. Mud can also be applied directly to corner bead by use of a sluice box or hopper to apply mud to the corner. The corner bead flanges are then affixed by using a corner bead roller, with excess mud being removed by hand using a drywall knife, making the edges of the corner bead smooth and attached.
SUMMARY OF THE DISCLOSURE
A disclosed embodiment has an elongated core having an outer surface and an inner surface. The elongated core has two flanges extending outward from the center of the elongated core. The flanges have a recessed portion beginning at a point outward from the center of the elongated core. This outward section of the flange has a paper section which abuts the end of the flange. On top of this core layer is an outer layer or exterior paper section that is attached to the inner of the core and to the paper section that is attached beginning at the recessed portion of the elongated core and extends outward to the end of the section abutting the elongated core. There is also an interior section that is on the inside of the corner. This section is configured for attachment to sheetrock. The outer section is such that it can be made out of fire resistant or mold resistant paper. The outer section is designed to be finished using a texture or can just be painted. The overall appearance of the corner provides a staggered tapered appearance such that the outer layer is wider than the interior layer. This allows for the sheetrock mud to placed along the tapered portion such that the a worker does not have to apply multiple sequential layers of mud followed by sanding between each application of mud. Once the corner is applied to the sheetrock wall, the mud on the edges of the corner can be sanded and the entire corner can be textured along with the sheetrock wall and subsequently painted.
In a preferred embodiment, the elongated core is a galvanized metal elongated core. It is in a preferred embodiment that this elongated core be 0.015 inches thick. In a preferred embodiment the overall flange length of the entire corner is between 1½ inches and 5¼ inches. This will allow for a variety of corners. In the event that the flange is too long for the worker, the worker can use a knife, such as a utility knife to cut the flange down to the correct size. Two opposing flanges can be of various sizes depending on the corner type that the corner is going to be installed on. The staggered tapered appearance of the corner allows for mud to be placed toward the edge of the corner and less mud to be used as the paper corners are tapered.
It is thought that the tapering of the papered corner will allow for a layer of mud to be placed on the corner, the corner to be smoothed down, excess mud removed, the corner sanded, if necessary, without additional applications of mud. This will provide for faster application of the corner because a worker, in the traditional methodology in which the recessed portion of the flange is not filled by paper, but instead is filled by mud that is sequentially layered and sanded several times in order to provide the overall finished appearance in which the corner tapers into the sheetrock.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the new corner bead.
FIG. 1P is an isometric view of the prior art corner bead.
FIG. 2 is a top view of the new corner bead. It shows a small piece of angled metal and four layers of paper. The outside mud fill areas are eliminated.
FIG. 2P is a top view of the prior art corner bead. It shows a large piece of angled metal and one layer of paper. Prior art corner bead has outside mud fill areas on the part.
FIG. 3 is a top exploded view of the new corner bead.
FIG. 4 is an isometric view of the new corner bead normally used in windows using 2″×6″ window framing.
FIG. 5 is an isometric view of new corner bead normally used in windows using 2″×4″ window framing.
FIG. 6 is a top view of the new corner bead normally used in windows using 2″×6″ window framing. The metal and paper layers are similar to FIG. 2 .
FIG. 7 is a top view of new corner bead normally used in windows using 2″×4″ window framing. The metal and paper layers are similar to FIG. 2 .
FIG. 8 is an isometric view showing the wall preparation for a window corner using 2″×4″ walls. This wall preparation applies to the use of both (corner bead FIG. 7 ) and (bullnose FIG. 12 ).
FIG. 8P is an isometric view showing the prior art wall preparation for a window corner using 2″×4″ walls. This wall preparation applies to the use of both (corner bead FIG. 2P ) and (bullnose FIG. 12P ).
FIG. 9 is an isometric view showing next installation step after FIG. 8 for the new corner bead.
FIG. 9P is an isometric view showing next installation step after FIG. 8P for the prior art corner bead.
FIG. 10 is an isometric view showing next installations step after FIG. 9 for the new corner bead.
FIG. 10P is an isometric view showing the results for the next three installation steps after FIG. 9P for the prior art corner bead.
FIG. 10A is an isometric detail view of the finished corner for FIG. 10 .
FIG. 10 PP is an isometric detail view of the finished and filled FIG. 10P .
FIG. 11 is an isometric view of the new bullnose.
FIG. 11P is an isometric view of the prior art bullnose.
FIG. 12 is a top view of the new bullnose. It shows a reduced curved metal support and three layers of paper. The outside mud fill areas are eliminated.
FIG. 12P is a top view of the prior art corner bead. It shows a large piece of angled metal and one layer of paper. It has outside mud fill areas on the part.
FIG. 13 is a top exploded view of new bullnose.
FIG. 14 is an isometric view of the new bullnose, used with 2″×6″ window framing.
FIG. 15 is an isometric view of the new bullnose, for use with 2″×4″ window framing.
FIG. 16 is a top view of new bullnose, for use in windows using 2″×6″ window framing.
FIG. 17 is a top view of new bullnose, for use in windows using 2″×4″ window framing.
FIG. 18 is an isometric view showing the new bullnose installation for a window in a 2″×4″ wall. This step follows the wall preparation shown in FIG. 8 .
FIG. 18P is an isometric view showing prior art bullnose installation for a window in a 2″×4″ wall. This step follows the wall preparations shown in FIG. 8P .
FIG. 19 is an isometric view showing next installations step after FIG. 18 for the new bullnose.
FIG. 19P is an isometric view showing the results for the next three installation steps after FIG. 18P for the prior art bullnose.
FIG. 19A is an isometric detail view of the finished corner for FIG. 19 .
FIG. 19 PP is an isometric detail view of the finished and filled FIG. 19P .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates an isometric view of the new corner bead. The new corner bead is constructed such that minimal mud is needed to finish the corner bead. The newly disclosed corner bead 2 of the application features a metal or plastic support corner 3 that is attached to layers (or sections) of paper, such that the paper forms a gradual tapering from the thicker center part of the corner 3 down to the edge of the corner bead 11 . This allows for the gradual tapering of the corner bead and allows for the mud just to be applied in fewer applications, such that multiple layers and drying time for the mud and subsequent multiple sandings are not needed. This is done by providing the corner 3 , which in a preferred embodiment which is approximately 0.015 inches thick (in other wording, approximately ⅛″ thick). This corner, in a preferred embodiment is thirty gage galvanized metal, can also be made using plastic or a combination of metal and plastic. The preferred width of each of the flanges of the metal is approximately ⅜ inch with paper extending the width up to 5¼ inches. It is thought that this is the preferred width that can be used, although smaller or wider could be potentially used.
The internal layers of paper 4 , 6 , 8 are preferably made from a 9 pt suture stock (5111-120). This paper is made by Monadnock in a preferred embodiment, although any paper will work consistent with the spirit of the current invention. The outer paper layer 10 is preferably made from drywall trim paper (1720-097) also constructed by Monadnock which can be treated with a mold or fire resistance paper.
FIG. 1P illustrates what is thought to be the current prior art in a generalized drawing. Illustrated in FIG. 1P , the prior art features a central metal or plastic corner 14 , as well as an extended paper 18 . These paper flanges are not tapered from a uniform flat exterior to the end and instead flange provides an indented section such that corner 14 provides recess 17 , that is filled with mud in sequential applications. This gap is filled with mud adhesive typically at least three times, with each of the layers being allowed to dry and typically are sanded before another layer of mud is applied in sequence. This leads to substantial increase of time in preparing drywall corners. The layered paper corner bead of the current invention uses a minimal metal or plastic center, although other material consistent with the spirit of the invention may be used.
Mud or adhesive is applied to the outside paper near the edge such that the adhesive or mud is layered over the edge of the paper onto the sheetrock. This outer paper is to be pre-finished for text or paint such that is not required to mud or outer adhesive before applying any further paint or texture. It is thought that in an ideal situation in which the framing of the building has been relatively straight, minimal mud will be needed on the paper bead in order to generate a proper corner. However, in the event that the framing is crooked or off center, multiple layers of mud can be used in order to square the corner. The paper can also be made with nodules for using mud to apply the corner of the wall to enhance mud application. This generates increased mud adhering to the paper of the corner bead. Alternatively, the paper can be left smooth to adhere by using glue. The pre-finished outside paper can be primed or textured without having coating with anything. Again, any type of metal or plastic can be used to make the corner consistent with the spirit of the invention. Alternatively, the corner bead can be made in a variety of corners, including square kerf jambs, bullnosed, baby bull, L-metal, an open angle or one thirty five degrees corner. The paper flange (and overall width of the flange of the corner bead) is generally from 1¼ inches to 5¼ inches wide depending on the overall width of the corner to be finished. A worker can finish the edge using either his or her hand or with tools. The corner bead can also be taped on and finished over.
A typical building is framed using 2″×4″ or 2″×6″ framing with ½ inch or ⅝ inch drywall. Thus a 1¼ to 5¼ inch corner bead flange can be used, eliminating coating at all on window returns while adjusting for different window thickness, between ½ inch to 1¼ inch. The worker can trim paper edge with razor knife as needed to match the window width. Thus 5¼ inch corner bead width reaches the window. There is no need to coat the window return with mud. This is, for example, illustrated in FIG. 10 .
FIG. 2 illustrates a top view of the new corner bead. As illustrated the length of elongate core 32 is slightly angled and is attached to four layers (also called sheets or sections) of paper to provide the new corner bead. In contrast FIG. 2P shows what is thought to be the prior art. Prior art features a wider metal core 38 and includes a single layer of paper 36 . As illustrated in FIG. 2 , the four layers of paper of the current invention creates a layered corner that provides for the general tapering of the corner from the point of the corner to the edge of paper 22 . This alleviates the need to fill the recess that is created by the angle of the core 32 . The small piece of metal 32 abuts with paper 26 such that the length of the piece of metal (or other core material) needed is reduced, thus likely decreasing cost of manufacturing the corner. The increased paper layers add longer rigidity to the corner without requiring a longer metal flange as shown in FIG. 2P , 38 .
FIG. 3 illustrates a top exploded view of the new corner bead. FIG. 3 illustrates the outer paper layer 52 that is attached to elongated metal core 42 . The elongated metal core 42 is attached to a layer of paper 50 that fills recessed portion 41 . Recessed portion 41 is approximately a ⅛ inch fill gap that is filled by paper 50 . The thickness of the interior layer 48 being generally 0.015 inches, second layer 44 is generally 0.015 inches, the third layer is generally 0.01 inches and the outer layer is generally 0.09 inches. This is thought to be the preferred embodiment, is exemplary of the invention, and is not meant to be limiting to the paper width. The edges as depicted in FIG. 3 are generally tapered in a preferred embodiment in order to provide a layered structure. The distance between the tapered edges of the four layers of paper is thought in a preferred embodiment to be 1 / 4 to ¾ of an inch although it can be smaller or greater depending on a worker's need. In a preferred embodiment, 9/16″ to ⅝″ is the preferred distance between the edges of the paper. As illustrated elongate core 42 abuts with edge portion 45 at seam 46 . This allows for the continued layering of the paper layers from the center metal portion.
FIG. 4 illustrates an isometric view of the new corner bead designed for windows using 2″×6″ window framing. The corner bead is generally in four layers or sections to create the staggered tapered appearance, although additional layers or sections could be added.
FIG. 5 illustrates an isometric view of a new corner bead used in windows that are framed using 2″×4″ window framing. FIGS. 6 and 7 illustrate the top views of the new corner bead for 2″×6″ window framing and 2″×4″ window framing, respectively. As illustrated for the 2″×6″ window corner 62 there is an elongated flange due to the wider stud of the window framing. In contrast, the 2″×4″ window framing uses a smaller flange, as illustrated. The edge of the flange abuts with the window, allowing for the entire framing to be finished with minimal mud application and sanding.
FIG. 8 illustrates an application of a corner to a windowed wall section. FIGS. 8 and 8P illustrate what must be done to prep the wall corner before both the current invention or the prior art can be applied as a corner. FIG. 8 illustrates the current invention, while FIG. 8P illustrates the standard prior art. FIG. 8 illustrates the sheetrock wall corner 66 having first sheetrock wall 70 and second sheetrock wall 72 against stud 71 . Mud is placed on the whole sheetrock surface of sheetrock 70 . The entire surface 70 of sheetrock wall 70 or alternately on the whole inside surface of the corner bead, or bullnose. Mud is also placed on the sheetrock wall from the closest edge of the sheetrock to the point 68 beyond where the corner bead or will cover. Subsequently, the comma as illustrated in FIGS. 9 and 9P , the corner bead is placed over the mud then pressed in place with a roller or taping knife. Excess mud is then wiped off.
FIGS. 10 A and 10 PP illustrate where mud is required on each of the perspective current invention and the prior art. In the current invention, minimal or no mud is required on the exterior of the corner 107 a , 107 b , but is required on the exterior of the corner at 107 c . This is because mud is not required to fill in the gap provided as shown in the prior art. In the prior art, mud must be used to cover the entire sheetrock surface 110 . Mud may need to be applied up to three times or even more depending on the shrinkage and drying of the mud on the sheetrock wall.
FIG. 10 illustrates a sheetrock window corner according to the present invention, while FIG. 10P illustrates a sheetrock corner according the prior art. As illustrated in FIG. 10 , mud is spread over flange 96 of corner 95 . Flange 98 does not require mud as it is adhered to the sheetrock behind it by the previously applied mud or adhesive. In FIG. 10P mud is required to be applied to both 102 and 104 . Again this mud is required to be applied in sequential layers and subsequently sanded after each layer. This allows for filling the gap as illustrated in FIG. 10 PP. FIGS. 11 through 13 represent the standard size of bullnose used for the invention. Bullnose, or round corner bead is used to create rounded corners. The corner and method can also be used on the interior of corner wall.
FIG. 13 illustrates an exploded view of the round bullnose corner, having paper sections 117 and metal section 115 . The corner differs from the prior art as the prior art has a recessed section that is to be filled with mud and sanded to finish the corner.
FIG. 14 illustrates a further view of the rounded end bullnose with an elongated flange 119 .
FIG. 15 illustrates a rounded bullnose section 120 having an elongated flange 121 .
FIG. 16 illustrates the top view of the bullnose corner of the current invention to be used in windows having 2″×6″ framing.
FIG. 17 illustrates the top view of the new bullnose used in windows having 2″×4″ framing.
FIG. 18 illustrates an isometric view showing the new bullnose installed in 2″×4″ window framing. This follows the same wall preparation steps shown in FIG. 8 and associated figures, illustrating steps for applying the corner.
FIG. 18P illustrates an isometric view showing the prior art bullnose installed in a window having 2″×4″ framing. This step follows the wall preparation shown in FIG. 8P and associated figures.
FIG. 19 illustrates an isometric view showing the steps following FIG. 18 for application. This illustrates that mud only has to be placed on one side 135 of the drywall pairing.
FIG. 19P illustrates that for prior art corner 146 , mud must be applied at both drywall sides of 137 .
FIG. 19A is an isometric detailed view of the finished corner for FIG. 19 . This illustrates that no mud is required to finish the side of sheetrock 139 .
FIG. 19 PP illustrates the close up view of corner 140 of the prior art. Side 140 is required to be finished with mud 141 that is layered and sanded sequentially.
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What is disclosed is a sheetrock corner bead that features an elongated core and paper flange extension for the elongated core. The flanges provide a layered tapered appearance that allow for less mud to be used and fewer mud applications required for installing the corner. The sheetrock corner bead provides for an improved method of installation that generally requires less mud and less time spent in installation.
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BACKGROUND OF THE INVENTION
The market demands that the textile printer manage an increasingly larger variety of print applications--more variety of design and more variety of color combinations per design--in smaller and smaller application sizes while still increasing the economic viability. With these requirements comes the demand to effectively shorten (effective in a productive sense) the ever increasing time required for rigging and cleaning. At the present tine, the purely printing production time in many printing houses is already less than 50% of the entire run time (work time), which is unacceptable.
Considering this objective, application equipment has been suggested which allow cleaning of the application equipment itself and if need be the round template surrounding it on the printing machine. Also, with such equipment, the possibility must be provided to transport a template to a washing machine installed next to the printing machine and clean it there if the color is to be changed in just one template. The invention thus pertains, similar to EP 0 494 339 A1, to an apparatus for the application of a substance onto a fabric train, particularly for textile printing, by means of round templates in which the application device includes equipment for the cleaning of the application equipment itself and of the template if necessary and in which the feed of the substance and of cleaning fluid proceeds through a tube parallel to the template and through a multitude of lateral exit holes. Between the exit holes and the point of application, or cleaning zone, no portions touching or carrying the applied substance or the cleaning fluid are located, so that the substance or cleaning fluid flows directly from the exit holes to the interior of the template. The equipment shown by EP 0 494 339 A1 avoids a disadvantage of the older equipment according to EP 0 277 481 B1, in which baffles are arranged for the distribution of a substance coming from the lateral exit holes, which bring into question the mandatory self-cleaning of the application equipment in the sense of the general objective. In order to achieve a uniform distribution of the substance to some extent over the width of the fabric train to be printed without such guiding and distributing surfaces, the substance is fed to the exit holes, whose typical spacing is 50-100 mm, under high pressure according to the state of technology. In order to build up an effective pressure over the entire exit width, the exit openings are small. The pressure must be high enough so that the substance does not exit in a closed stream per EP 0 494 339 A1, but rather is sprayed in a fan shape.
SUMMARY OF THE INVENTION
The invention starts with the reasoning that the spraying of the substance and of the cleaning fluid under high pressure is not optimal for either the application process or for the cleaning process. The goal, first strived for by the invention, of retaining templates and application equipment in a combined constructed state is only achievable through an optimization of the cleaning process if cleaning is done by choice in a specialized washing machine.
According to the invention, the application equipment is to be retrofitted such that the normally viscous applied substance (printing paste, printing colors) can flow (not spray) nearly pressureless in a slowly streaming condition at greatly reduced pressure compared to the inlet pressure in a practically closed stream of uniform thickness distributed evenly over the application width at the point of application. Since low pressure is used in the application procedure the pressure at cleaning can be significantly increased whereby water or another non-viscous cleaning material reaches the round template interior wall with high velocity straight in the axial direction of the exit holes and flushes it. The template openings are permeated by the cleaning fluid which makes a certain cleaning of the template exterior possible.
The desired method of functioning is accomplished according to the invention by making the distances between axes of the exit holes 5-20 mm, advantageously 5-15 mm, independent of the length of the application equipment, and by making the sum of the cross sectional area of all exit holes at least twice as large as the area of the inlet port in the tube body. To supply the substance to the point of application immediately up to a back-fill element, a new path according to the invention is taken in more than one respect: the substance fed/guided is divided many times so effectively through a flow dividing-channel body constructed in a new fashion in the application equipment, such that an exit separation of only 20 nun at the most is brought about (preferred 5-15 mm); this is applicable to all, i.e. independent of all existing application widths in practice which lately, according to the invention, can be as high as 10 meters. The application equipment according to the invention becomes technically and economically interesting also for applications without round templates or screening cylinders. In what follows, the sum of the substance discharge cross sectional area is a multiple--at least double--of the inlet flow cross sectional area, whereby the outlet pressure is reduced to nearly zero with reliably achievable discharge uniformity. The spraying out, or wide spray associated with the previous state of technology does not occur according to the invention.
Use of the equipment according to the invention opens interesting new technical and economic possibilities. Following the general objective described above, the cleaning process is included in the requirements of the print production as it corresponds otherwise to the current view of this production process in its entirety: application, cleaning, and fit-up requirements must be viewed as a technical-economic unit. This invention must also be seen in this sense. In accordance with the invention, the possibility is presented, in which the cleaning process is carried out at the printing machine depending on the respective printing method or a transfer is made to a cleaning machine constructed and set up close to the printing machine according to the invention.
The invention pertains essentially to two pieces of equipment, which can be connected into a single unit in the previous sense. The foundation is the application equipment per the invention, which is also a cleaning device and indeed as well a self cleaning unit as well as a template cleaning unit; at least for round template interior cleaning, which is the more difficult. The first piece of equipment is an application unit, which at the same time is a cleaning unit for the substance delivery equipment, for the back-fill element and for the round template and which can be employed in this multiple function selectively in the printing machine or in the cleaning machine which constitutes the second piece of equipment.
It is characteristic of the process of the invention that the cleaning procedure always covers the entire functioning unit of the printing process, i.e. application device (back-fill device) and round template together; this independent of whether the cleaning takes place in the printing machine or outside of the printing machine. The choice is free to the operator. If only 1-2 printing units (application unit together with template) must be cleaned during a color change within the same design, the operator will prefer the separate washing machine; if all printing equipment of a printing machine must be cleaned (design change), the operator will prefer to clean within the printing machine. Still, it is possible to clean the majority of the printing equipment inside the printing machine, while at the same time cleaning a few in the separate washing machine. Another criterion for such selection is the flow-through characteristics of the template. Templates which print a relatively large pattern coverage--somewhat more than 10% of the entire surface--can be cleaned advantageously inside the printing machine; if the color flow-through consists of less than 10%, however, separate cleaning must be preferred since the cleaning is carried out in the washing machine per the invention in an inclined position in which the water (the cleaning fluid) can run off better, i.e. faster, than in the printing machine. The choice of one of the two cleaning types is therefore characteristic of the process as is also the simultaneous use of both cleaning types side by side. Both cleaning types are made possible by the application equipment constructed per the invention, and indeed particularly by means of the substance delivery equipment.
Significant concerning the invention are thus substance delivery without the presence of any equipment outer surfaces in contact with the substance, suitability of the substance delivery equipment for the cleaning of the application equipment with considerably reduced usage of cleaning fluid (water) compared to previously (characteristic of water-conserving, complete self-cleaning), suitability to self-cleaning without tear-down (removal) of the application equipment from the round template which contains it and at the same time suitability as cleaning equipment for the round template as well, particularly for the inner surface and the substance flow-through openings of the round template. The advantage of the invention is that there is no requirement for additional fit-up of the printing machine with cost-intensive vacuum equipment since the small amount of cleaning fluid flows to a conveyor through the template openings and is fed into the existing wash-water collection tank of the printing machine. Should only individual printing equipment be cleaned and changed out during a change of only a single color of a multi-colored pattern, in which the other colors remain unchanged, and/or should printing equipment with such templates that have only a very small total flow-through be cleaned, since then only small pattern fractions are printed, the second process provided per the invention comes into consideration; that is, cleaning of the entire printing equipment--application/back-fill equipment and template together--in the washing machine constructed per the invention. If round templates are removed from the production equipment for cleaning, a separation of the application equipment arranged in the round template from the template has occurred up until now without exception and a special cleaning of template and application equipment was done. The template was placed in a unit, as is described in European Patent application 0 418 672 (Johannes Zimmer). Rotating cylinder brushes clean the outside of the template while a spray tube placed through the template along its entire length introduces cleaning fluid. The invention attains in contrast a substantial simplification, in which provisions are made for the removal of the round template together with the application equipment arranged in it and these are placed in the washing machine. The addition of cleaning fluid to the round template in the washing machine is carried out through the application equipment.
By using the process per the invention for self-cleaning application equipment, the special cleaning of the application equipment is eliminated. It is already cleaned by fulfilling its function in the process of cleaning the template. If the application equipment includes a magnetically attachable back-fill roll which lies on the application equipment under the influence of permanent magnets, the cleaning of this back-fill roll can also be accomplished in the course of the unitized washing process per the invention. Whether or not the invention is usable with the highest effect in self-cleaning application equipment, it could still be used in application equipment in which the cleaning fluid is fed independently of the distribution system for the applied substance. Particularly with self-cleaning application equipment, such an additional feed system in the application equipment is sensible. This has the goal above all of intensively cleaning the inside of the template and a provided back-fill roll as necessary.
The general cleaning of round templates and application equipment represents the end phase of a total process consisting of application and cleaning. The task is particularly then, to manifest the transfer between these two steps optimally. The feed of cleaning fluid through the application equipment is in this sense only then expedient if previously the application substance has been already largely removed from the application equipment. In the sense of a relinquishment to one particular equipment for cleaning of the application equipment, a preferred variation of the process per the invention is provided in which pumps feeding the applied substance during the production process draw off the excess applied substance in the reverse functioning direction before the feeding of cleaning fluid before the washing procedure takes place.
A surprising advantage of the invention lies in that the better the application unit is suited for template cleaning, the correspondingly better it is suited for its actual production task, namely the uniform width-distributed delivery of substance to a point of application, within the scope of the process per the invention. In order to carry out the process per the invention, it is preferable to use an application unit in which the distribution system of the application equipment ends in a row of tubular nozzles, whose separation spacing is 5-20 mm independent of the length of the application unit. With this, it is particularly characteristic of the invention as well as for application and for subsequent cleaning, that between the nozzles and the point of application, or cleaning zone, no parts carrying or in contact with the applied substance or cleaning fluid are installed so that the substance or cleaning fluid flows directly in free fall out of the nozzles to the inside of the template. The use of a magnetically attached back-fill roll is suited perfectly to the objective first proposed here of optimizing the application process in its entirety, that is to keep track of the fit-up, tear-down and retrofit, and cleaning of the application equipment itself and that of the template simultaneously with the functioning of the application equipment in the production process. The back-fill roll moving the substance through the template in the production process assists with its continuous or intermittent operation during the cleaning process in the inner and outer cleaning of the round template and is thereby itself cleaned.
BRIEF DESCRIPTION OF THE DRAWINGS
Other particulars of the invention are illustrated in the accompanying drawings, wherein:
FIGS. 1a-1e are schematic illustrations illustrating various steps in a process according to the present invention;
FIG. 2a is a cross section through an application device according to the invention;
FIGS. 2b and 2c are views in the direction of arrow A of FIG. 2a during application of substance and supply of cleaning fluid, respectively;
FIGS. 3a and 3b are a plan view and a partial view illustrating features of another process according to the present invention;
FIG. 4 is a side view illustrating an apparatus employed in the process shown in FIG. 3a;
FIGS. 5a and 5b are schematic end views illustrating two embodiments of a magnetic apparatus employed in the process of FIG. 3a; and
FIGS. 6a and 6b are partial schematic views illustrating supply of cleaning fluid to an application device in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1a shows the primary function of an application unit 5 is to apply a substance 18 onto a fabric moving by means of a printer's blanket 22 through a round or cylindrical template 1. The round template 1 is stretched over rotating mounted end rings 2 (not represented in detail). The substance 18 is fed by a pump 14, preferably a tubular pump, through hose sections 20' and 20 of the application unit 5 and distributed uniformly therefrom. That the application unit 5 is suited for the production process in the same way as for individual cleaning and cleaning of the template, is explained in more detail in connection with FIGS. 2a-5b.
If round template 1 and application unit 5 are cleaned during lengthy or temporary interruption of the production process, the effective direction of the pump 14 is first of all, as shown in FIG. 1b, reversed and the substance remaining in the application unit 5 is added to the substance supply 18. In order to avoid the downward dripping of the substance at the end of or during an interruption of the printing operation which occurs after lifting the printing equipment by slow continued turning of the template upward on the inner wall, just the magnetic field is shut off first per the invention prior to lifting. With this back-fill roll 8 is moved from the template from the solid line position of FIG. 1b to the dashed line position. If, however, the template turns at least one complete rotation, wall 11 acts as a slotted wiper which spreads the substance into a thick layer corresponding to the separation from the template in a slotted wiper layering fashion. A comparable layer of this type then no longer drips. One can then either continue production after the interruption or wash in the printing machine or in the separate washing machine without having substance drip from the outer side of the application unit 5 which then must later be removed again with a separate cleaning procedure. This is an important measure manifesting the main idea of the invention.
As an intermediate step, water can be sucked from container 15 as shown in FIG. 1c after loosening tube connection 23, whereby the applied substance is pushed from the tube section 20, from the pump 14 and from the large portion of the tube section 20' and returned to the supply 18. It must be ensured that this process step proceeds quickly enough so that either no or only minimal cleaning fluid (water) finds its way into the substance supply 18. This procedure (cleaning step) can be optimized per the invention by employing a compressible stopper, for example made of foam rubber, in the take-up of the suction line 20'. This stopper intensifies the cleaning effect of the flowing fluid similar to a sponge. The preferred tubular pump per the invention is a pre-requisite for the use of this invention manifesting, total-cleaning-process-optimizing measure. The cleaning object (sponge or the like) passes through and cleans the tubular pump as well therewith per the invention and separates at the same time the substance from the subsequently flowing medium.
FIG. 1d shows how a self-cleaning application unit 5 is cleaned without removing it from the production equipment. Water 15 can be fed through the pump 14 and through the tube sections 20 and 20'. This process can be aided with compressed air as indicated by arrow 21. While the substance supply 18 is replaced by a coloring supply 18', the cleaning fluid can be fed from the application unit 5 back into the water container 15 or into a wastewater channel (FIG. 1e).
FIG. 2a shows in schematic representation total cross section through an application unit 5 constructed per the invention. It is to be understood that the flow channels located spatially behind one another seen in the direction of the longitudinal axis and channel connections in the illustrated plane are arranged next to one another. In this illustration, only that cross sectional portion of a flow distribution channel body 6 (distribution system 6) in which no hollow space exists on the entire length of the equipment is shown shaded. Object 6 is encased air-tight by a square tube on all sides, and a round pipe or flow channel Kl extends from one of two opposite sides of the unit to at least the middle of body 6, and at the same time to the middle of the application region (the exit width or working width). The applied substance or the cleaning fluid is fed to channel K1 through the connection piece 23 (in FIG. 4). If this round pipe projects through the body 6 to the end thereof, such round pipe can act as wing spar, both ends of which act on an advantageously tiltable carriage (not shown). Alternatively, such function can be achieved by the square tube.
An air-tight perpendicular wall can be installed in the middle area of the round pipe, whereby the inside area of the pipe is divided into two exact or approximately equally large flow areas. Thus, applied substance can be fed during printing to one end, and cleaning fluid can be fed to the other end during washing in alternating fashion. The substance is fed over the path K1-K2-K3, etc., through the equipment, and the cleaning fluid is fed on the other side through channel K1' into channel K2' (pipeline 7) and exits this channel through nozzles 19', preferably in a line of narrowly aligned holes of equal diameter--for the purpose of cleaning of the inside of the wall 11 and of any existing back-fill element in the application area.
In the embodiment of FIG. 2a, the flow channel distribution system is carried out with 13 distribution steps, which corresponds to a very large working width. The exit holes are illustrated by K13. The substance flows with very low pressure out of the openings K13, following the force of gravity, in a vertical flow direction 18' to the point of application or to application by the back-fill element, which can be a back-fill roller or a back-fill wiper or a slotted wiper, as shown in FIG. 2a.
During the cleaning procedure, the cleaning fluid exits from the nozzles K13 under relatively high pressure in direction 18", which corresponds to the axis of the exit nozzles K13 and effects the cleaning of the template after and in addition to the interior cleaning of the body 6. Detail views in the direction of arrow A in FIG. 2a are shown in FIG. 2b and 2c and represent schematically a view of 18' during the outflow of the substance, and a view of the cleaning fluid 18" exiting the holes K13 under pressure on the flow path during template cleaning, respectively. The shaded additional flow body identified by 6'" represents an embodiment per the invention through which the relatively widely distanced discharge area K13 is transferred to a discharge area K13' close to the template.
The template 1 touches the conveyor, for example, or the printer's blanket 22, or for example a roll 4 or an overlay 28, 29 thereon, or the like (FIGS. 5a and 5b), during the application procedure and also during at least a portion of the cleaning procedure.
FIG. 3a shows a process variation per the invention of the cleaning of a printing unit. Round template 1 with end rings 2 held in position is stretched and driven as in the printing machine and is built into the application equipment per the invention. FIG. 3b shows a detail of the printing machine after the printing equipment is removed and placed into a washing machine per the invention.
In a variation of the process per the invention the process step according to FIG. 1d and also that according to FIG. 1a as necessary is carried out outside of the production equipment in the washing machine represented in FIG. 3a. The round template 1 is removed from the printer's blanket 22 together with the application unit 5 per the invention and is placed into the washing machine. The same pump 14 can be used for cleaning of the round template 1 as was used during the production procedure and for the reverse suction of excess substance according to FIG. 1b. Also, yet another water connection can be chosen. As required, additionally or selectively, compressed air can also be fed through one of the connectors 16, 16' in this fluid guiding feed system. This variation has the advantage that in the process of cleaning the template 1 not only the application unit 5, but also the pump 14 and connecting tubes 20, 20' are cleaned.
FIG. 4 shows the washing equipment 3 in a schematic side view. The details of the mounting of the end rings 2, the template 1, a motor 24, cleaning roll 4, tilting equipment 25, etc., are not illustrated in detail since these details are well known, e.g. as shown in AT 360 949 (Johannes Zimmer). The only equipment features specifically illustrated are those that are novel in connection with the present invention. A magnetically attachable back-fill roll 8 belonging to the application equipment 5 may be rolled continuously or intermittently on the inside of the round template 1 during the cleaning procedure. For this purpose, an electromagnet or a permanent magnet 27 can be provided inside the roll 4 to guide the back-fill roll 8 from a rest position maintained by a permanent magnet 9 to the working position seen in FIG. 5b. During the cleaning procedure, the roll 4 rotates and drives the round template 1 fastened in mounting 17 by means of its end rings. Such driving can also be accomplished separately. Simultaneously, cleaning fluid is fed through the applied substance distribution system 6 and through the additionally provided fluid supply line 7. In this way, the application unit 5, the back-fill roll 8, and the interior of the round template 1 are cleaned. The exterior cleaning of the round template 1 is accomplished for example by contact with a suction overlay 28 suited for cleaning (FIG. 5a) or according to the variation of FIG. 5b by means of a brush 29 surrounding the roll 4. Also possible is a rubber overlay.
The embodiment of FIG. 5b is different from that of FIG. 5a essentially in that the attachment of the back-fill roll 8 is accomplished, not through an electromagnet or permanent magnet 27 inside the roll used in relation to one another, but rather through, for example, two permanent magnets 10 built into the surface of the roll 4 or the brush 29.
It is above all notable concerning the equipment in FIG. 5a and FIG. 5b, that the distance of the nozzles 19 of the distribution system 6 for the substance can be optimized in the area of 5-20 mm such that on the one hand a homogeneous width distribution of the substance is accomplished, on the other hand an outstanding cleaning effect in the inner cleaning of the round template 1 is accomplished. The additionally fed cleaning fluid over system 7 has the task above all of cleaning the backfill roll 8 and the support ledge or wall 11.
By addition of compressed air, the application equipment is dried in its interior areas, not only on the outer surface. If the application equipment is employed subsequently after cleaning for a new application procedure without removing the template, dripping water or cleaning fluid from run-off from the equipment rear wall 11 can cause application errors. In order to avoid this, the rear wall 11 is provided with a small rim 12 in which fluid drops remaining on the upper and rear equipment surfaces after the cleaning procedure and which run down by gravity can be collected. This measure avoids application errors by retaining fluid which otherwise would drop onto the template.
FIG. 6a shows details of a connector 26 shown only in FIG. 4 for the supply line 7 located on the lower side of the application unit 5 for cleaning fluid. This can consist according to FIG. 6b of tubes connected to one another on one end for flow, whereby a few variations of the discharge holes arranged in a row are represented; a row of holes in only one of the two tubes, only one row of holes in both tubes or none in one tube and two rows of holes arranged next to each other in the second tube.
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A template and an application device of an apparatus for application of a substance to a fabric train are cleaned either in situ within the application apparatus or after being withdrawn as a unit and supported in a separate washing device. Cleaning fluid is supplied to the application device at an inlet thereof that is the same that receives substance to be applied to the fabric train. The cleaning fluid is discharged from the application device through a plurality of discharge holes having respective discharge axes. The discharge holes are arranged with the discharge axes extending parallel to each other and spaced in a direction parallel to the template at intervals of 5-20 mm between adjacent axes. The discharge holes are spaced from the template such that the substance or cleaning fluid passes from the discharge holes directly to the template. The discharge holes have a total cross sectional area that is at least twice a cross sectional area of the inlet to the application device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/639,433, filed Dec. 27, 2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
FIELD OF THE INVENTION
[0003] The present invention is directed to a fishing device most commonly a sinker, and more particularly to a fishing sinker with improved resistance to snags and capable or reversing line direction to be withdrawn from obstacles.
BACKGROUND OF THE INVENTION
[0004] When fishing, one generally wants the fishing line and attached bait or lure to sink below the water surface, so that the bait may be seen by the fish. Typically, one attaches a sinker to a fishing line, which is generally a weight with a density greater than water. The sinker may be attached to the fishing line at a fixed position, or may be able to slip or slide along a portion of the line. These slidable sinkers are generally referred to as slip sinkers. The sinker may be made of a dense metal, such as lead or an alloy of lead, and may have a protective coating to prevent significant contact between the lead and the water. The sinker may also have a buoyant portion in addition to the dense portion, in order to achieve a desired orientation in the water. The sinker may optionally be colored in a manner that is appealing to fish, such as a combination of bright, fluorescent colors.
[0005] Fishing sinkers tend to sink to the bottom of the fishing area, and a common drawback is that they may become snagged in fishing areas with rocks, brush, weed beds or stump fields (i.e. become engaged with environmental obstacles). When a sinker becomes snagged, one typically attempts to free the sinker by pulling generally upward on the fishing pole. If that doesn't work, one may let the line go slack, translate the pole a few feet in a given direction parallel to the water surface, then attempt to pull upward again. The process of letting the line go slack, translating the pole and pulling upwards may be repeated until the sinker is freed, or until patience is lost and the sinker is abandoned.
[0006] Abandoning a sinker is undesirable for a number of reasons. First, the sinker costs money to replace. Second, the sinker may contain lead and may potentially contaminate the fishing area. Third, the individual who lost the sinker may be subject to hurtful ridicule from his or her fishing companions.
[0007] Accordingly, there exists a need for a sinker with improved snag resistance, so that the process of letting the line go slack, translating the pole and pulling upwards may be more effective at freeing a snagged sinker.
SUMMARY
[0008] There are several aspects to the invention and reference should be had to the detailed description and the claims. For the reader's convenience a summary of some of salient features appears below.
[0009] For example, one embodiment includes a snag resistant fishing sinker system which has a first filament having a first and second end, a sinker weight being attached to said first filament proximate said ends, an attachment link to a fishing line, slidably engaging said first filament so that it can selectively slide between ends; so that the link can be moved by tensioning of a fishing line to avoid entanglement of the system with environmental obstacles.
[0010] A further feature includes a system where the first filament is substantially rigid.
[0011] In another embodiment, the system of claim 2 wherein said first and second ends are attached to said sinker weight to form at least one corner.
[0012] In another embodiment the first and second ends are attached to the sinker weight to form at least two corners and wherein the link is slidable between said corners.
[0013] In another embodiment the first filament includes a bend intermediate said first and second ends so that said link may engage said either said first or second end or said bend.
[0014] In a further embodiment, the bend is generally midway between said first and second ends and forms an apex between said ends.
[0015] In a further embodiment, the said bend is generally midway between said first and second ends and wherein said filament follows a generally arcuate shape.
[0016] In a further embodiment the arcuate shape is concave relative to the sinker weight.
[0017] In a further embodiment the filament extends generally from said first to said second end and a float slidable therealong.
[0018] In a further embodiment the float has sufficient buoyancy to tend to raise whichever end it is most adjacent.
[0019] In a further embodiment the further filament is substantially rigid.
[0020] In a further embodiment the filament is substantially rigid and extends from the sinker weigh at one end thereof, follows around the sinker weight toward its other end and terminates at the sinker weight adjacent the first end and has a corner adjacent its second end, so that the link may be moved from the first end to the second to avoid environmental entanglement.
[0021] A method of making a snag resistant sinker system is also disclosed including the steps of suspending a fishing element to the ends of a substantially rigid filament; establishing a plurality of corner bends in said filament; slidably attaching a fishing line to said filament capable of sliding therealong and engaging said bends; so that tensioning the fishing line at different angles can cause the slidable attachment to move to bend most effective in disentangling said sinker system from environmental obstacles.
[0022] The above summary is just exemplary. Reference should be had to the detailed description for further inventive concepts and to the claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] FIG. 1 illustrates a prior art fishing sinker.
[0024] FIG. 2 illustrates a prior art fishing sinker, wedged between two rocks.
[0025] FIG. 3 illustrates an embodiment of a fishing sinker.
[0026] FIG. 4 illustrates an embodiment of a fishing sinker, wedged between two rocks.
[0027] FIG. 5 illustrates an embodiment of a fishing sinker, wedged between two rocks.
[0028] FIG. 6 illustrates a further embodiment of a fishing sinker, with a filament with rounded corners.
[0029] FIG. 7 illustrates a further embodiment of a fishing sinker, with a filament with more than two corners.
[0030] FIG. 8 illustrates a further embodiment of a fishing sinker, with a weight that is slidable along the filament.
[0031] FIG. 9 illustrates a further embodiment of a fishing sinker, with a rattle.
[0032] FIG. 10 illustrates a further embodiment of a fishing sinker, with a float incorporated into the clasp.
[0033] FIG. 11 illustrates a further embodiment of a fishing sinker, with a float that is slidable along a filament.
[0034] FIG. 12 illustrates a further embodiment of a fishing sinker, with a gumdrop-shaped weight.
[0035] FIG. 13 illustrates a further embodiment of a fishing sinker, with a gumdrop-shaped weight and a rattle.
[0036] FIG. 14 illustrates a further embodiment of a fishing sinker, with a weight on a slidable clasp.
[0037] FIG. 15 illustrates a further embodiment of a fishing sinker, with a more than one slidable clasp.
[0038] FIG. 16 illustrates a further embodiment of a fishing sinker, with a decorated weight, multiple hooks, and a hydrodynamic fin.
DETAILED DESCRIPTION OF THE INVENTION
[0039] A prior art fishing sinker 10 is shown in FIG. 1 . A weight 11 is rigidly attached to a clasp/link 13 by a filament 12 . The clasp 13 may either attach directly to a fishing line, between the bait and the pole, or may attach to an intermediate device that enables attachment to the fishing line. The term clasp or attachable link should be read broadly as the connection to the fishing line, and indeed the fishing line itself. In can be as simple as a slidable knot or complex as a link element which itself attaches to the fishing line. Once cast into a fishing area, the prior art sinker 10 sinks and carries the bait below the surface of the water to a depth at which it may be seen by the fish.
[0040] As the fisherman artfully adjusts the positions of the pole/rod and the line, in order to entice fish to eat the bait, the prior art sinker 10 may become entangled in some structures on the bottom of the fishing area. For instance, it may become wedged between rocks, or snagged in plant beds. FIG. 2 shows the prior art sinker wedged between two rocks 21 and 22 . (The rocks 21 and 22 are drawn with a rectangular profile for simplicity.) In an attempt to free the snagged sinker, the fisherman may use the pole to exert a force on the line, and in turn, exert a pulling force on the sinker. This pulling force is represented schematically by element 27 , and shows the direction in which the fisherman pulls. The pulling force denoted by 27 is exerted on the clasp 13 , and based on the orientation of the wedge of the rocks 21 and 22 , FIG. 2 shows that such a force will not free the snagged sinker.
[0041] Once the fisherman realizes that pulling in the direction denoted by 27 will not free the snagged sinker, he may optionally shift his position in the boat or on the dock, then try pulling in a second direction. This second direction is denoted by element 26 , and a pulling force denoted by direction 26 is also exerted on the clasp 13 . FIG. 2 shows that this force, too, will not free the snagged sinker. Presumably, the fisherman will be unable to dislodge the prior art sinker using the fishing line, and will have to abandon the prior art sinker at the bottom of the fishing area, possibly leaving lead at the bottom of the lake.
[0042] FIG. 3 shows an embodiment of a fishing sinker 30 with improved snag resistance. A sinker has been illustrated throughout, but it is understood that any fishing element could be used in this configuration. A lure, a spinner, rattle, bait (live or synthetic) or any fishing device that can be tied to a fishing line, is liable to become entangled in environmental obstacles. Because sinker weights are the most problematic, they are used for illustration, but should not be considered a limitation of the invention. A weight 31 may be formed generally from a dense material, such as lead or an alloy of lead, and may have a protective coating to prevent significant contact between the lead and the water. The weight 31 may also have a buoyant portion (not shown), in order to achieve a desired orientation in the water. The weight 31 may optionally be colored in a manner that is appealing to fish, such as one or more bright, fluorescent colors. Furthermore, the weight 31 may preferably have an elongated or tubular shape, with a first end 35 and a second end 36 . The weight 31 is preferably located at the midpoint between the corners (end points) but as it is not on the same filament, spaced therefrom. Thus the center of gravity of the weight (or other fishing device) will preferably along a line running orthogonally through the midpoint between the corners. (This is only true on non slidable embodiments, of course)
[0043] The first end 35 and second end 36 may be connected by a filament 32 having a linear/straight section and arcuate sections. The filament 32 may preferably be a generally or substantially rigid wire, which may optionally be coated to prevent corrosion. Its rigidity should be taken broadly. It should be rigid enough that the link can slide therealong. It can also be very rigid as that would aid in slidability. Alternatively, the filament 32 may be made from a synthetic material, such as plastic or nylon. The filament 32 may extend externally from the first end 35 to the second end 36 , and may be joined to the weight 31 only at the ends 35 and 36 . Alternatively, the filament 32 may extend partially into the weight 31 , or may pass completely through a hole (not shown) in the weight 31 . In the embodiment of FIG. 3 , it is preferable that the weight 31 be rigidly attached to the filament 32 . In further embodiments, the weight may slide along the filament, which extends through a hole in the weight.
[0044] A clasp 34 is slidably attached to the filament 32 . In this case, a sliding ring is shown, but any means for slidable engagement is possible so long as the resistance is low. The clasp 34 may either attach directly to a fishing line, between the bait and the pole, or may attach to an intermediate device that enables attachment to the fishing line.
[0045] The filament 32 preferably has one or more corners 33 a, 33 b . (Note that “corners” (interchangeably used with “bends”, “junctions”, etc., should be interpreted broadly and junctions or bends and are not limited to corners in the traditional sense.) The link 34 is slidably engaged along the filament and may engage any of the corners/bends so as to allow the fishing line to alter the vector or directional force applied to the sinker system thereby resulting in reversal or partial change of direction depending upon where the bends are located along the filament.) Although the corners 33 a, 33 b are drawn as sharp corners, they may be formed as regions in which the local curvature is distinctly greater than the surrounding regions. Sharper or acute angle corners may have an advantage that the reversing function is stepwise and more distinct, as will be explained below. In other words, the corners 33 a, 33 b may be simply bends in the filament 32 , with a local radius of curvature that is conducive to well-known wire manipulation techniques. If the filament 32 is formed from a synthetic material, rather than shaped from a wire, then the corners 33 a, 33 b may either be sharp, or may be rounded.
[0046] A utility of the two corners 33 a, 33 b is visible from FIGS. 4 and 5 , in which the sinker 30 is shown wedged between two rocks 41 and 42 . (As in FIG. 2 , the rocks are drawn as rectangular in profile for simplicity. Furthermore, it should be noted that the rocks may be rotated by 90 degrees about the longitudinal axis of the weight 31 , so that one rock is below the plane of the page, and one rock is above the plane of the page. This orientation as described is more likely in practice, but more difficult to draw in a single-pane representation.)
[0047] Analogous to FIG. 2 , the fisherman first pulls along a direction denoted by element 47 in FIG. 4 , and is unable to free the snagged sinker. However, as shown in FIG. 5 , when the fisherman shifts the direction of pull, denoted by element 46 , the clasp 34 first slides from corner 33 a to corner 33 b, then applies a force at corner 33 b in the direction of 46 . Unlike force 47 , the force denoted by 46 is applied against the direction of the wedge of rocks (weeds, branches, etc.) 41 and 42 , and may therefore extract the snagged sinker from the rocks 41 and 42 . Therefore, compared with the prior art sinker 10 , the sinker 30 shows an improved snag resistance.
[0048] One potential contributor to the improved snag resistance of sinker 30 may be the allowed reversibility of the sinker's motion. Unlike the prior art sinker 10 , the sinker 30 allows the clasp position to change, depending on the direction of pull. In the embodiment of FIGS. 3-5 , the two corners 33 a and 33 b are on opposite sides of the weight 31 , and when the clasp 34 engages each of these corners, the sinker 30 may be pulled in opposite directions. If a particular motion (caused by force 47 ) manages to wedge the sinker 30 between two rocks, as in FIG. 4 , then a corresponding motion (caused by force 46 ) in another direction should therefore be able to dislodge the sinker. The ability to retract the sinker, or extract a sinker from a snagged location, may be known as reversibility.
[0049] FIG. 6 shows an additional embodiment of a sinker 60 . A preferably elongated weight 61 has its first end 65 connected to its second end 66 by a filament 62 . A clasp 64 is slidably engaged along the filament at one end, and at its second end, either attaches directly to a fishing line between the bait and the pole or, alternatively, attaches to an intermediate device that enables attachment to the fishing line. The filament has two corners 63 a and 63 b that may engage the clasp 64 when forces are applied in the appropriate directions. Note that the corners 63 a and 63 b may be either rounded or sharp, preferably acute, such as between 30 and 45 degrees. Here again, the term corners must be read broadly as they are clearly just angular bends. The concept of filaments “joined” at corners is applicable also, but the meaning of joined, must also include a continuous filament and the joining is not physically distinguishable.
[0050] FIG. 7 shows an additional embodiment of a sinker 70 . Drawing elements 70 - 76 are analogous to 60 - 66 and 30 - 36 . In comparison with sinker 60 in FIG. 6 , note that the filament 72 may have more than two corners. In particular, filament 72 has three corners 73 a, 73 b and 73 c to form a “crown of these points, with corner 73 c at the apex. Note that the sections of filament 72 between corners may be either straight or curved. Those portions of the filament between 73 a - b - c are also straight or curved. If curved, they are preferably an arcuate shape, convex as viewed from the sinker weight 71 . This convex interior helps keep the link/claps 74 in one of the bends/corners in response to tension of the fishing line pulled along a selected vector. In particular, filament 72 is curved inwards between corners 73 a, 73 b and 73 c. An inward curve may be preferable, in that it may guide the slidable clasp 74 more readily to a corner 73 a, 73 b or 73 c. Note that the corners 73 a, 73 b and 73 c may all be sharp, as drawn, or may preferably be slightly rounded in order to simplify the manufacturing process. The advantage of this structure is that the apex point provides an alternative “exit” direction of pull in case the other directions are not sufficient to extricate the sinker. Likewise, additional corners or bending points will provide additional angles for extrication.
[0051] FIG. 8 shows an additional embodiment of a sinker 80 . A weight 81 with a first end 85 and a second end 86 is hollowed out (i.e. being in slidable engagement with the filament, and having a passage of greater diameter that the filament outer diameter), and is drawn in cross-section in FIG. 8 . A filament 82 passes through the hole in the weight 81 , and the weight 81 may slide along a section of the filament 82 between corners 87 and 88 . A clasp 84 is slidably attached to the filament 82 , which may slide between corners 83 a and 83 b depending on the direction of pull, as shown in FIGS. 4 and 5 . Note that the corners 87 and 88 may preferably not engage the slidable clasp 84 ; the directions of pull as shown in FIGS. 4 and 5 preferably guide the slidable clasp 84 to either corner 83 a or 83 b. Any or all of the corners 83 a, 83 b, 87 and 88 may optionally be rounded, as well as the sections of filament between them.
[0052] Using a sliding weight, such as element 81 in FIG. 8 , may be advantageous in achieving a desired orientation for the sinker. For instance, if the sinker 80 is suspended by the clasp 84 and engaged at corner 83 a, then weight 81 slides along the filament 82 until it reaches corner 85 , thereby shifting the center of mass away from 83 a, and increasing the rotational inertia of the sinker 80 . (Rotational inertia may sometimes be referred to as moment of inertia.) Because the rotational inertia (about the clasp) is increased, it takes a greater force to change the orientation of the sinker. Put another way, given a particular set of obstacles at the bottom of a fishing area, a sinker may be more likely to stay in its desired orientation if its rotational inertia is increased.
[0053] FIG. 9 shows an additional embodiment of a sinker 90 . Drawing elements 90 - 96 are analogous to 30 - 36 , except that the weight 91 includes a rattle 98 . The use of rattles is generally well-known to fisherman, and the thumps, ticks, clicks and clatters that rattles emit are known to lure fish. The rattle 98 may be a generally hollow cavity, in which several ball bearings may roll around and knock into each other. Although FIG. 9 shows the rattle 98 surrounded by the weight 91 , the rattle 98 may also be embedded on an edge of the weight 91 , or attached externally to the weight 91 . Furthermore, the rattle 98 may be detached from the weight 91 , and either free to slide along the filament 92 independent of the weight 91 , or fixedly attached to the filament 92 or the clasp 94 .
[0054] FIG. 10 shows an additional embodiment of a sinker 100 . Drawing elements 100 - 106 are analogous to 30 - 36 , except that the slidable clasp 104 includes a float 108 , which attaches to the fishing line by an additional clasp 109 . The additional clasp 109 may either attach directly to the fishing line, between the bait and the pole, or may attach to an intermediate device that enables attachment to the fishing line. The float 108 may be made of a buoyant material with a density less than water, such as cork or balsa. Alternately, the float 108 may contain a pocket of low-density material, such as an air bubble, preferably sealed to minimize contact with the water. The float helps orient the fishing line vertically and may keep it in the elected corner for extrication.
[0055] FIG. 11 shows an additional embodiment of a sinker 110 , in which a float 118 is attached to its own filament, either slidably or fixedly. In the slidable configuration, the float slides along a filament preferably running from one corner to the other (in a two corner system) and preferably rigid to allow the float to slide therealong. Drawing elements 110 - 116 are analogous to 30 - 36 . Although the float 118 may be fastened to the same filament 112 as the weight 111 , it is preferable to use a separate filament, so that the float and weight may move past each other if required. Note that more than two filaments may be used, as well as multiple floats or weights. With a float of sufficient buoyancy, the float itself can help orient/urge/raise one end of the sinker system upwardly, to allow the line to more easily seek a corner or end when tensioned (i.e. pulled up). Otherwise, the fisherman may have to shake the line to find a corner.
[0056] FIG. 12 shows an additional embodiment of a sinker 120 , in which the weight 121 is not elongated, but is gumdrop or projectile shaped with an apex and a conical body. Note that although any shaped weight may be used, it may be preferable to use a shape in which the center of mass is located distant and perhaps as far from possible from the nominal clasp engagement corner 123 b. Note that the corners 123 a, 123 b and 123 c offer multiple engagement points for the slidable clasp 124 , and do not necessarily have to be located on opposite sides of the weight 121 . The filament is preferably rigid and extends outwardly from the weight and rises to an apex above the weight.
[0057] During nominal sinker operation (in other words, when the sinker is not snagged), it may be desirable for the sinker to hang from one particular corner. For instance, the sinker 120 of FIG. 12 may preferably hang from corner 123 b during normal operation. One method to preferentially favor one corner over another is to tailor the filament shape so that when hung from one particularly undesirable corner, the clasp slides to the desired corner. Using the example of FIG. 12 , if one accounts for the center of mass of weight 121 , and properly locates corner 123 a (or 123 c ) and the local slope at each point along the filament between 123 a (or 123 c ) and 123 b, the sinker will re-orient itself under the influence of gravity to the desired orientation. A guiding principle when designing the contour of the filament is that the local slope at each point (corner), when the entire sinker is hung from that point, should be large enough to overcome friction. When the filament is shaped properly, the clasp will preferably not get stuck between corners.
[0058] FIG. 13 shows another embodiment of a sinker 130 , in which a rattle 138 is attached to the weight 131 . Drawing elements 130 - 134 are analogous to 120 - 124 .
[0059] FIG. 14 shows another embodiment of a sinker 140 , in which the weight 141 is attached to the filament 142 by a slidable clasp 149 . Drawing elements 140 - 144 are analogous to 120 - 124 . Note that the filament 142 is preferably rigid, and preferably retains its shape as the slidable clasps 144 and 149 move along it. Additional features may be combined with the embodiment in FIG. 14 , including a float, a float on an additional filament, or a rattle.
[0060] FIG. 15 shows another embodiment of a sinker 150 , in which a second clasp 158 is slidably attached to the filament 152 . Drawing elements 150 - 156 are analogous to 30 - 36 . Slidable clasp 154 may be attached to the fishing line (connected to the fishing rod), and slidable clasp 158 may be attached to the bait (or to an intermediate line, which is in turn connected to the bait). During normal operation, clasp 154 is engaged with corner 153 a , and clasp 158 is engaged with corner 153 b. If the sinker 150 becomes snagged at the bottom of the fishing area, the slidable clasp 154 may be slid to corner 153 b to dislodge the sinker 150 , as shown in FIGS. 4 and 5 . Note that more than two clasps may be used, as well.
[0061] The weight on the sinker may also be shaped, colored and textured to be more appealing to fish. For instance, the sinker 160 of FIG. 16 has a weight 161 that resembles a fish. The exemplary filament 162 of FIG. 16 extends from the front end of the weight 161 , at corner 163 a, to the back end of the weight 161 , at corner 163 b , although it need not follow the contour of the weight, and need not span the full extent of the weight. The weight 161 shown in FIG. 16 is exemplary, and any decorative or functional design may be used, including geometric patterns. Furthermore, the weight may include hydrodynamic features, such as fins or ridges, that may cause the sinker to wiggle as it moves through the water, in order to lure fish. A lip 168 is shown on the sinker 160 in FIG. 16 , which may impart a wiggling motion to the sinker as it passes through the water.
[0062] Note that the sinker 160 may have one or more additional features attached to it, including hooks 167 . Note that the additional features, such as the hooks 167 , may or may contribute to the sinking ability of the sinker, or the effectiveness in removing the sinker if it becomes stuck. Furthermore, the additional features may or may not directly contribute to the ability to lure or catch fish.
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This disclosure is directed to a fishing system capable of reducing loss due to entanglement with environmental obstacles. The most common form of device is a sinker. The construction of this system allows the user tension the line in different direction to extricate the fishing element from obstacles by easily reversing the direction of line tension.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stereophonic voice recording and playback device for recording a voice signal on a solid-state recording medium such as a semiconductor memory and for reproducing such recorded information as a voice signal. And more particularly, the present invention relates to a solid-state stereophonic voice recording and playback device suitable for use as a stereophonic conference dictating machine.
2. Description of the Related Art
FIGS. 1 and 2 show a recording section and a playback section, respectively, for a conventional voice recording and playback device such as disclosed by Japanese Laid-Open Patent Publication No. 55-58815.
Hereinafter, the configuration and operation of the conventional voice recording and playback device will be described. First, an analog waveform representing a voice signal serves as an analog input signal which is sampled by a sampling circuit 100 at a predetermined sampling rate. The sampled values are supplied to an Analog-to-Digital (A/D) converter 101, where the sampled analog waveform is converted to a digital signal. The digital signal is subsequently supplied to an information compressing circuit 102, where the digital signal data is compressed in accordance with a predetermined compression procedure. The compressed data is then written into and stored in a voice information recording section 111 of a solid-state record section 110. At this time, information to indicate a reconstruction procedure corresponding to the compression procedure used by the information compressing circuit 102 is written to and stored in a reconstruction procedure recording section 112 of the solid-state record section 110.
The solid-state record section 110 further includes a controller 113. To reproduce data, the data stored in the voice information recording section 111 is read out, and then the original data before compression is reconstructed using the controller 113 in accordance with the reconstruction procedure information stored in the reconstruction procedure recording section 112. Thereafter, the reconstructed data is supplied to a Digital-to-Analog (D/A) converter 120, where it is converted to the original analog voice signal, and subsequently it is outputted to a speaker section.
According to the above-described voice recording and playback device, only a monophonic voice signal can be recorded and reproduced. A position from which a voice originates cannot be ascertained, such as is possible with a stereophonic voice recording and playback device. Therefore, a conventional voice recording end playback device as described above cannot be applied to a conference dictating machine which enabled us to recognize a position of each speaker for readily determining who speaks.
Even though it is possible to record and reproduce a stereophonic voice signal by modifying the above voice recording and playback device according to conventional techniques, there arises a problem of a high production cost. Such modification for providing stereophonic recording and playback necessitates each of two circuits 100 and 102 and converters 101 and 120 and at least one solid-state record section 110. According to such a configuration, the required information content is doubled, which disadvantageously decreases the recording and playback time to one-half. That is, the required memory capacity of the solid-state record section 110 is increased twice as much as that of the stereophonic voice recording and playback device for recording and reproducing data providing the same amount of recording time. For the above reasons, when the conventional voice recording and playback device is used for recording and reproducing the stereophonic voice signal, the configuration thereof becomes complicated and thus the production cost is significantly increased.
FIG. 3 shows a conventional method for converting analog signals in two channels to digital signals using a single A/D converter, such as disclosed in Japanese Laid-Open Patent Publication No. 55-17850.
In FIG. 3, the analog signals L and R in the corresponding two channels are inputted to low-pass filters 71 and 71', respectively. The outputs of the low-pass filters 71 and 71' are inputted to sample and hold (S/H) circuits 72 and 72', respectively, where each analog value is sampled and held, at a predetermined sampling rate, and outputted to an analog switch 73. Using the analog switch 73, the sampled signals L and R are alternately outputted to an A/D converter 74, where they are converted to digital signals in alternating order such as L n , R n , L n+1 , R n+1 , . . . . That is, the digital signals of L i and R i are alternately outputted.
To sample the signals L and R at a frequency of F s Hz, the S/H circuits 72 and 72' should be operated at the frequency of F s Hz, and the analog switch 73 should be operated at a frequency of 2×F s Hz. Accordingly, the A/D converter 74 should have a band width of 2×F s Hz, and thus the A/D converter 74 is required to be operated at a high speed with high precision. However, according to this A/D converter 74, the signals L and R are alternately converted, so that samples from the same signal cannot successively be converted. Therefore, a delta-sigma modulation type A/D converter including a delay circuit cannot be used for this purpose even though such a delta-sigma modulation type A/D converter, which employs a primarily digital circuit technique, not requiring a high-precision analog circuit technique in order to achieve high-precision A/D conversion without requiring adjustment, is very useful for an integrated circuit.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a stereophonic voice recording and playback device is provided for stereophonically recording and reproducing voice signals, including:
an adding circuit for receiving a first channel analog voice signal and a second channel analog voice signal, performing quadrature conversion of the respective analog voice signals, and adding the orthogonally converted signals to produce an added signal,
an Analog-to-Digital (A/D) converter for receiving the added signal from the adding circuit and converting the added signal to a digital signal,
a compressing circuit for receiving the digital signal from the A/D converter and compressing the digital signal,
a memory circuit for storing the compressed digital signal, and
an expanding circuit for accessing the digital signal from the memory circuit and reproducing a stereophonic signal.
In one embodiment of the invention, the A/D converter, the compressing circuit, the memory circuit, and the expanding circuit are integrated on the same substrate.
In one embodiment of the invention, the A/D converter is of delta-sigma modulation type.
In one embodiment of the invention, the stereophonic voice recording and playback device further includes a circuit for dividing the digital signal converted by the A/D converter into a digital signal corresponding to the first channel voice analog signal and a digital signal corresponding to the second channel voice analog signal. In addition, the compressing circuit includes:
a compressing section for compressing one of the two digital signals,
a differential calculating circuit for calculating the difference between the two digital signals,
a differential compressing section for compressing the difference calculated by the differential calculating circuit, and
a data writing circuit for writing data compressed by the compressing section and data compressed by the differential compressing section into the memory circuit.
In one embodiment of the invention, the compression ratio of the compressing section and the compression ratio of the differential compressing section is different from each other.
In one embodiment of the invention, the stereophonic voice recording and playback device further includes a circuit for dividing the digital signal converted by the A/D converter into a digital signal corresponding to the first channel analog voice signal and a digital signal corresponding to the second channel analog voice signal. In addition, the compressing circuit includes:
an adding circuit for calculating the sum of the two digital signals,
a sum compressing section for compressing the sum calculated by the adding circuit,
a differential calculating circuit for calculating the difference between the two digital signals,
a differential compressing section for compressing the difference calculated by the differential calculating circuit, and
a data writing circuit for writing data compressed by the sum compressing section and data compressed by the differential compressing section into the memory circuit.
In one embodiment of the invention, the data writing circuit writes both of the data compressed by the compressing section and the data compressed by the differential compressing section into one address in the memory.
In one embodiment of the invention, the data writing circuit writes both of the data compressed by the sum compressing section and the data compressed by the differential compressing section into one address in the memory circuit.
In one embodiment of the invention, the stereophonic voice recording and playback device further includes a data reading circuit for reading out the data compressed by the compressing section and the data compressed by the differential compressing section both written into one address in the memory circuit.
In one embodiment of the invention, the stereophonic voice recording and playback device further includes a data reading circuit for reading out the data compressed by the sum compressing section and the data compressed by the differential compressing section both written into one address in the memory circuit.
In one embodiment of the invention, the expanding circuit includes:
a data reading circuit for reading out the data compressed by the sum compressing section and the data compressed by the differential compressing section written into the memory circuit,
a first expanding section and a second expanding section for independently expanding the data compressed by the sum compressing section and the data compressed by the differential compressing section read out from the data reading circuit, and
a differential calculating circuit for calculating the difference between data expanded by the first expanding section and data expanded by the second expanding section.
In one embodiment of the invention, the expanding circuit includes:
a data reading circuit for reading out the data compressed by the sum compressing section and the data compressed by the differential compressing section written into the memory circuit,
a first expanding section and a second expanding section for independently expanding the data compressed by the sum compressing section and the data compressed by the differential compressing section read out from the data reading circuit,
a differential calculating circuit for calculating the difference between data expanded by the first expanding section and data expanded by the second expanding section, and
a sum calculating circuit for calculating the sum of the data expanded by the first expanding section and the data expanded by the second expanding section.
In one embodiment of the invention, the compression ratio of the first expanding section and the compression ratio of the second expanding section is different from each other.
Thus, the invention described herein makes possible the advantages of (1) providing a stereophonic voice recording and playback device capable of providing long duration stereophonic recording and playback, and which can be applied to a communication recording and playback device such as a dictating machine; (2) providing a stereophonic voice recording and playback device with a simplified configuration and a low production cost; and (3) providing a stereophonic A/D converting circuit to be used as a delta-sigma modulation type A/D converter.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a circuit configuration for a recording section for a conventional solid-state voice recording and playback device.
FIG. 2 is a block diagram showing a circuit configuration for a playback section for the conventional solid-state voice recording and playback device.
FIG. 3 is a block diagram illustrating a conventional method for converting analog signals to digital signals.
FIG. 4 is a block diagram illustrating a recording section for a solid-state stereophonic voice recording and playback device according to a first embodiment of the present invention.
FIG. 5 is a block diagram illustrating a playback section for the solid-state stereophonic voice recording and playback device according to the first embodiment.
FIG. 6 is a block diagram illustrating a circuit for converting analog signals to digital signals according to the present invention.
FIGS. 7A to 7C show the frequency spectrum of signals according to the method for converting analog signals to digital signals in accordance with the present invention.
FIG. 8 is a block diagram illustrating a recording section for the solid-state stereophonic voice recording and playback device according to a second embodiment of the present invention.
FIG. 9 is a block diagram illustrating a playback section for the solid-state stereophonic voice recording and playback device according to the second embodiment.
FIG. 10 is a block diagram illustrating a recording section for the solid-state stereophonic voice recording and playback device according to a third embodiment of the present invention.
FIG. 11 is a block diagram illustrating a playback operation for the solid-state stereophonic voice recording and playback device according to the third embodiment.
FIG. 12 is a block diagram showing a circuit configuration for a recording section for a stereophonic dictating machine according to a first example of the present invention.
FIG. 13 is a de%ailed block diagram showing a compressor provided in the recording section of FIG. 12.
FIG. 14 is a block diagram showing a delta-sigma modulation type A/D converter according to the present invention.
FIG. 15 is a block diagram showing a circuit configuration for a playback section for the stereophonic dictating machine according to the first example.
FIG. 16 is a detailed block diagram showing an expander provided in the playback section of FIG. 15.
FIG. 17 is a block diagram showing a circuit configuration for a recording section for a stereophonic dictating machine according to a second example of the present invention.
FIG. 18 is a detailed block diagram showing a compressor provided in the recording section of FIG. 17.
FIG. 19 is a block diagram showing a circuit configuration for a playback section for the stereophonic dictating machine according to the second example.
FIG. 20 is a detailed block diagram showing an expander provided in the playback section of FIG. 19.
FIG. 21 is a block diagram showing a circuit configuration for a recording section for a stereophonic dictating machine according to a third example of the present invention.
FIG. 22 is a detailed block diagram showing a compressor provided in the recording section of FIG. 21.
FIG. 23 is a block diagram showing a circuit configuration for a playback section for a stereophonic dictating machine according to the third example.
FIG. 24 is a detailed block diagram showing an expander provided in the playback section of FIG. 23.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the present invention will be described by way of illustrating preferred embodiments and examples according thereto with reference to the drawings.
FIGS. 4 and 5 show an exemplary recording section and a playback section, respectively, for a stereophonic voice recording and playback device according to a first embodiment of the present invention.
Initially, a recording operation for the stereophonic voice recording and playback device will be described referring to FIG. 4.
First, stereophonic voice signals L and R are produced as is conventional by a left microphone and a right microphone, respectively, in response to speech sound, and then the voice signals L and R are inputted to a sampling circuit 50, where the input signals L and R (analog signals) are sampled and converted to digital signals X and Y, respectively. For example, each of the digital signals X and Y has 10 bit or more. The digital signals X and Y are subsequently inputted to a compressing circuit 51, where they are compressed in accordance with a compression method, such as Adaptive Differential Pulse Code Modulation, thereby obtaining compressed data X' and Y'.
The compressed data X' and Y' are written into a location at a selected address in a memory 52. For example, the compressed data X' is written into a more significant bits portion, and the compressed data Y' is written into a less significant bits portion. Thus, the compressed data X' and Y' are recorded in the memory 52.
Next, a playback operation for the stereophonic voice recording and playback device will be described with reference to FIG. 5.
The compressed data X' and Y' stored in the location of the selected address in the memory 52 are read out by an expanding circuit 53, and then are expanded in accordance with an expansion method corresponding to the above compression method, thereby obtaining the original digital signals X and Y before compression. Subsequently, the obtained digital signals X and Y are converted to the original analog voice signals L and R using a D/A converter 54.
Next, a method for converting the stereophonic voice signals L and R to the digital signals X and Y according to the present invention will be described with reference to FIG. 6. For simplification of description, a filter to remove unwanted frequency components, and the like, and not affecting the effects of the present invention, are omitted in FIG. 6.
The analog signal L is multiplied by a COS wave outputted from a sine wave generating circuit 62 using a multiplier 61 (quadrature conversion). On the other hand, the analog signal R is multiplied by a SIN wave outputted from the sine wave generating circuit 62 using a multiplier 61' (quadrature conversion). The COS wave and the SIN wave each have a frequency of w which is set higher than the highest frequency of signals L and R. The output of the multiplier 61 is: L×COS (wt), and that of the multiplier 61' is: R×SIN (wt). The outputs from the multipliers 61 and 61' are inputted to an adder 63. The output S1 out of the adder 63 is represented by the following equation (1):
S1.sub.out =L×COS (wt)+R×SIN (wt) (1)
The frequency spectrum of the signals L and R and the output S1 out of the adder 63 are shown in FIGS. 7A and 7B, respectively. Assuming for the sake of example that each of the signals L and R has frequency spectrum as shown in FIG. 7A, the output S1 out of the adder 63 (i.e., the modulated signals) has a frequency spectrum as shown in FIG. 7B. Thus, the bandwidth (2×w) of the output S1 out of the adder 63 is about twice the bandwidth of each signal L or R.
As shown in FIG. 6, the output S1 out of the adder 63 is inputted to a single A/D converter 64 to produce a digital signal representing digital output of the adder 63. The digital signal produced by the A/D converter 64 is a sampled and quantized signal, but herein it is assumed to be equivalent to the signal represented by the above equation (1) for simplification of description. To separate the signal represented by the equation (1) into original signals and isolate the signal L, the A/D converted signal is multiplied by a COS wave having a frequency of w with a multiplier 65 and another sine wave generating circuit 62'. The resulting output S2 out which is represented by the following equation (2) is then inputted to a low-pass filter 66 having a bandwidth of w. ##EQU1##
At this stage, the frequency spectrum of the output S2 out of the multiplier 65 is shown in FIG. 7C, where the original signal L alone remains in the band not higher than the frequency of w. Accordingly, by passing the output S2 out of the multiplier 65 through the low-pass filter 66 having the band of w, the signal L can be obtained.
Similarly, to obtain the signal R, the output signal of the A/D converter 64 is multiplied by the SIN wave having a frequency of w outputted from the sine wave generating circuit 62', using a multiplier 65'. Then, the resulting output S3 out represented by the following equation (3) is inputted to a low-pass filter 66' having a band of w. That is, the multiplier 65' and the low-pass filter 66' are used for obtaining the digital signal R.
S3.sub.out ={R-R×COS (2×wt)+L×SIN (2×wt)}/2(3)
FIGS. 8 and 9 show an exemplary recording section end a playback section, respectively, for a stereophonic voice recording and playback device according to a second embodiment of the present invention.
Hereinafter, a recording operation for the stereophonic voice recording and playback device will be described referring to FIG. 8.
First, stereophonic voice signals L and R are produced conventionally by a left microphone and a right microphone, respectively, in response to speech sound, and then the voice signals L and R are inputted to a sampling circuit 50, where the input signals L and R (analog signals) are sampled and converted to digital signals X and Y, respectively. The digital signals X and Y are inputted to a compressing circuit 60. The compressing circuit 60 includes a first compressing section 610, a second compressing section 630, a differential calculating circuit 620, and a data writing address controlling section 640.
First, the differential calculating circuit 620 calculates the difference (X-Y) between the digital signals X and Y. The thus calculated result (X-Y) is inputted to the second compressing section 630. On the other hand, the digital signal X from the sampling circuit 50 is inputted to the first compressing section 610.
By the first and second compressing sections 610 and 630, the digital signal X and the differential digital signal (X-Y) are each compressed, respectively, in accordance with a compression method, such as Adaptive Differential Pulse Code Modulation, thereby obtaining compressed data X' and (X-Y)'.
The compressed data X' and (X-Y)' are inputted to the data writing address controlling section 640. The digital signals X and Y which, for example, originate from the same voice sounds, are correlated with each other to some extent. Therefore, an information content of the digital differential signal (X-Y) is less than that of the digital signal X. Therefore, the second compressing section 630 can perform the compression process using less bits compared with the first compressing section 610, and therefore the compression ratio of the second compressing section 630 is higher than that of the first compressing section 610. Thus, compared with the case using two compressing sections having the same compression ratio, this configuration advantageously makes it possible to make recording and playback time longer using the same memory capacity.
As a result of the data writing address controlling section 640, the compressed data X' and (X-Y)' are written into a location of a selected address in a memory 52. For example, the compressed data X' is written into a more significant bits portion, and the compressed data (X-Y)' is written into a less significant bits portion. Thus, the compressed data X' and (X-Y)' are recorded in the memory 52.
Next, a playback operation for the stereophonic voice recording and playback device will be described referring to FIG. 9.
The compressed data X' and (X-Y)' written into the location of the selected address in the memory 52 are read out by an expanding circuit 70, and the original digital signals X and Y before compression are reconstructed. The expanding circuit 70 includes a data reading address controlling section 71, a first expanding section 72, a second expanding section 73, and a differential calculating circuit 74.
First, the data reading address controlling section 71 reads out the compressed data X' and (X-Y)' from the memory 52, and then the compressed data X' is outputted to the first expanding section 72, and the compressed data (X-Y)' is outputted to the second expanding section 73. By the first and second expanding sections 72 and 73, the compressed data X' and (X-Y)' are expanded in accordance with an expansion method corresponding to the above-referenced compression method of the first and second compressing sections 610 and 630, thereby obtaining the original digital signals X and (X-Y) before compression. The compression ratio of the second expanding section 73 corresponding to the second compressing section 630 is higher than that of the first expanding section 72 corresponding to the first compressing section 610.
The reconstructed digital signal X is outputted from the first expanding section 72 to a D/A converting circuit 75 and the differential calculating circuit 74. The reconstructed digital signal (X-Y) is outputted from the second expanding section 73 to the differential calculating circuit 74.
The differential calculating circuit 74 subtracts the digital signal (X-Y) from the digital signal X to obtain the digital signal Y. Thereafter, the digital signal Y obtained by the differential calculating circuit 74 is outputted to the D/A converting circuit 75. Accordingly, the D/A converting circuit 75 receives the digital signals X and Y which are to be converted to the analog voice signals L and R. Then, the digital signals X and Y are D/A converted using the D/A converting circuit 75, thereby reproducing and outputting the original voice signals L and R.
As is described above, by writing both of the compressed data X' and (X-Y)' to a single location of the selected address in the memory 52, it is possible to readily control the data writing operation and data reading operation.
FIGS. 10 and 11 show an exemplary recording section and a playback section, respectively, for a stereophonic voice recording and playback device according to a third embodiment of the present invention.
Hereinafter, a recording operation for the stereophonic voice recording and playback device will be described referring to FIG. 10.
First, stereophonic voice signals L and R are produced by a left microphone and a right microphone, respectively, in response to speech sound, and then the voice signals L and R are inputted to a sampling circuit 50, where the input signals L and R (analog signals) are converted to digital signals X and Y, respectively, as described above. The digital signals X and Y are subsequently inputted to a compressing circuit 80. The compressing circuit 80 includes a sum calculating circuit (adding circuit) 81, a first compressing section 82, a differential calculating circuit 83, a second compressing section 84, and a data writing address controlling section 85.
First, the sum calculating circuit 81 calculates the sum of the digital signals X and Y, and the resulting output (X+Y) is provided to the first compressing section 82. On the other hand, the differential calculating circuit 83 calculates the difference between the digital signale X and Y, and the resulting output (X-Y) is outputted to the second compressing section 84. By the first and second compressing sections 82 and 84, the digital signals (X+Y) and (X-Y) are compressed, respectively, thereby obtaining compressed data (X+Y)' and (X-Y)'.
The compressed data (X+Y)' and (X-Y)' are inputted to the data writing address controlling section 85. Here again, the digital signals X and Y are correlated with each other in some degree, and therefore, an information content of the digital signal (X-Y) is less than that of the digital signal (X+Y). Therefore, the second compressing section 84 can perform the compression process using less bits compared with the first compressing section 82. Therefore, the compression ratio of the second compressing section 84 is higher than that of the first compressing section 82.
As a result of the data writing address controlling section 85, the compressed data (X+Y)' end (X-Y)' are written into a location of a selected address in a memory 52. For example, the compressed data (X+Y)' is written into a more significant bits portion, and the compressed data (X-Y)' is written into a less significant bits portion. Thus, the compressed data (X+Y)' and (X-Y)' are recorded to the memory 52.
Next, a playback operation for the stereophonic voice recording and playback device will be described referring to FIG. 11.
The compressed data (X+Y)' and (X-Y)' stored in the location of the selected address in the memory 52 are read out by an expanding circuit 90 to reconstruct the original digital signals X and Y before compression. The expanding circuit 90 includes a data reading address controlling section 91, a first expanding section 92, a sum calculating circuit 93, a second expanding section 94, and a differential calculating circuit 95.
First, the data reading address controlling section 91 reads out the compressed data (X+Y)' and (X-Y)' from the memory 52, and then the compressed data (X+Y)' is outputted to the first expanding section 92, and the compressed data (X-Y)' is outputted to the second expanding section 94. By the first and second expanding sections 92 and 94, the compressed data (X+Y)' and (X-Y)' are expanded in accordance with an expansion method corresponding to the compression method used by the first and second compressing sections 82 and 84, thereby obtaining the original digital signals (X+Y) and (X-Y) before compression. Thus, the compression ratio of the second expanding section 94 corresponding to the second compression section 84 can be set higher than that of the first expanding section 92 corresponding to the first compressing section 82.
The generated digital signals (X+Y) and (X-Y) are each outputted to the sum calculating circuit 93 and the differential calculating circuit 95. The sum calculating circuit 93 calculates the sum of the (X+Y) and (X-Y), thereby generating the digital signal X. On the other hand, the differential calculating circuit 95 calculates the difference between the digital signals (X+Y) and (X-Y), thereby generating the digital signal Y. The generated digital signals X and Y are respectively outputted by the sum calculating circuit and the differential calculating circuit to a D/A converting circuit 96, where they are converted from digital to analog signals, thereby reproducing and outputting the original voice signals L and R.
Hereinafter, the present invention will be described in detail by way of illustrating examples of the above described embodiments with reference to drawings.
(EXAMPLE 1)
FIGS. 12 to 16 show a stereophonic dictating machine of an example according to the above second embodiment of the present invention (FIGS. 8 and 9).
Initially, the configuration and operation for a recording section of the stereophonic dictating machine is described with reference to FIGS. 12 to 16.
First, stereophonic voice signals L and R are produced by a left microphone inputting section 1L and a right microphone inputting section 1R, respectively, in response to speech sound, and then the voice signals L and R are inputted to an A/D converter 2. The A/D converter 2 is connected to both of the microphone inputting sections 1L and 1R. Using the A/D converter 2, the input voice signals L and R are each sampled at a predetermined sampling frequency (e.g., 8 kHz ), and converted to digital signals X and Y, respectively.
In the present example, a delta-sigma modulation type A/D converter 180 (FIG. 14) is used as the A/D converter 2. A configuration for a circuit including such a delta-sigma modulation type A/D converter 180 will be described in detail below with reference to FIG. 14.
As is shown in FIG. 14, the delta-sigma modulation A/D converter 180 includes an adder 184, an integrator 185, a one-bit quantizer 186, a decimation filter 187, and a delay circuit 188. Because of inclusion of the delay circuit 188, the integrator 185 and the decimation filter 187 which are affected by past values, the circuit cannot employ a switch such as that shown in FIG. 3. The other elements shown in FIG. 14 are similar to those of FIG. 6. More specifically, the analog signals L and R are passed through low-pass filters 181 and 181' respectively, to remove high frequency components (e.g., 4 kHz or more), and are then modulated by multipliers 182 and 182', respectively. Herein, a sine wave with a frequency of 4 kHz or more is obtained by converting a signal generated by a digital sine wave generating circuit 911 to an analog signal using a D/A converting circuit 192. The D/A converting circuit 192 includes a D/A converter 921 and a band-pass filter 922. By using the sine wave generated by the digital circuit, it is possible to make no difference in frequencies between a modulation mode and a demodulation mode, thereby preventing a demodulation signal from being distorted. The circuit of FIG. 14 further includes a π/2 phase shifter 193, an adder 183, multipliers 189 and 189', low-pass filters 190 and 190' having a bandwidth of w, and a sine wave generating circuit 191. The sine wave generating circuit 191 has a digital π/2 phase shifter 912 and the digital sine wave generating circuit 911.
According to the delta-sigma modulation type A/D converter 180, a signal-to-noise ratio (SNR) can be improved employing an over sampling technique using a one-bit A/D and a noise-shaving technique. To be more specific, the analog signal outputted from the adder 183 is sampled at an over sampling rate, and then noise is removed using the decimation filter 187, and finally, the sampling rate is reduced back to the normal sampling rate.
Referring again to FIG. 12, the digital signal X from the A/D converter 2 is inputted to a first compressor 4A and a subtracter 3. The digital signal Y from the A/D converter 2 is inputted to the subtracter 3. The subtracter 3 subtracts the digital signal Y from the digital signal X. The thus obtained differential digital signal (X-Y) is outputted to a second compressor 4B.
As a result of the first and second compressors 4A and 4B, the digital signals X and (X-Y) are compressed, respectively, in accordance with the above mentioned Adaptive Differential Pulse Code Modulation, thereby obtaining compressed data X' and (X-Y)'. Herein, the digital signals X and Y are correlated with each other to some extent, and therefore, an information content of the digital differential signal (X-Y) is less than that of the digital signal X. Therefore, the second compressor 4B can perform the compression process using less bits compared with the first compressor 4A, and therefore the compression ratio of the second compressor 4B is higher than that of the first compressor 4A. To be more specific, the compressing (encoding) operation is performed by the first compressor 4A using 4 bits, while it is performed by the second compressor 4B using 2 bits. Thus, compared with the case using two compressing sections having the same compression ratio, this configuration advantageously makes it possible to make recording and playback time longer using the same memory capacity.
Next, the compressed voice data X' and (X-Y)' generated by the first and second compressors 4A and 4B are supplied to a memory controller 5 to control a writing operation into a memory 6. The memory controller 5 in turn writes the compressed data X' and (X-Y)' to a location of a selected address in the memory 6. For example, the compressed data X' is written into a more significant bits portion, and the compressed data (X-Y)' is written into a less significant bits portion. Thus, the compressed data X' and (X-Y)' are recorded in the memory 6.
The first and second compressors 4A and 4B are identical, and it will be sufficient to describe the first compressor 4A with reference to FIG. 13.
The compressor 4A includes a subtracter 7, a quantizer 8, a quantization width controller 9, an adder 10, and a memory 11. To generate the compressed data X', the compressor 4A is operated as follows: First, the subtracter 7 calculates the difference between the true digital signal X currently supplied from the A/D converter 2 and an estimated current digital signal obtained from an digital signal one sample before which was recorded in the memory 11. The thus calculated output is supplied to a quantizer 8.
Using the quantizer 8, the input signal outputted from the subtracter 7 is quantized in accordance with a quantization width set by the quantization width controller 9. The quantization width controller 9 encodes a value quantized by the quantizer 8, and then controls the quantization width in accordance with the encoded value. The output of the quantizer 8 is inputted to the adder 10.
The adder 10 calculates the sum of the input signal from the quantizer 8 and an input digital signal one sample before to estimate the next digital signal value. The memory 11 holds a single most recent output from the adder 10.
The thus compressed data X' is written into a location of a selected address in the memory 6.
Next, a playback operation for a playback section of the stereophonic voice recording and playback device will be described referring to FIGS. 15 and 16. The playback section includes a memory controller 13, a first expander 14A, a second expander 14B, a subtracter 22, and D/A converters 15L and 15R. The original analog voice signals L and R are reproduced by this playback section, and then are amplified by amplifiers 16L and 16R, and finally are inputted to left and right speakers 17L and 17R, respectively, thereby producing a stereophonic voice sound.
To reproduce the original analog voice signals, the compressed data X' and (X-Y)' written into the memory 6 are read out by the memory controller 13, and then are outputted to the first and second expanders 14A and 14B. By the first and second expanders 14A and 14B, the compressed data X' and (X-Y)' are expanded in accordance with an expansion method corresponding to the above compression method, thereby obtaining the original digital signals X and (X-Y) before compression. The digital signal X from the first expander 14A is inputted to the D/A converter 15L and the subtracter 22. The digital signal (X-Y) from the second expander 14B is inputted to the subtracter 22. The subtracter 22 subtracts the digital signal (X-Y) from the digital signal X, and the thus obtained output Y of the subtracter 22 is inputted to a D/A converter 15R.
Thereafter, the digital signals X and Y are converted to analog voice signals L and R by the D/A converters 15L and 15R, respectively. The thus reproduced analog voice signals L and R are outputted to amplifiers 16L and 16R, respectively. The voice signals L and R are amplified to a predetermined level using the amplifiers 16L and 16R, and then are outputted to left and right speakers 17L and 17R, respectively, thereby producing stereophonic voice sound corresponding to the voice signals.
The compression ratio of the second expander 14S corresponding to the second compressor 4B is set higher than that of the first expander 14A corresponding to the first compressor 4A. The first and second expanders 14A and 14B are identical, and it will be sufficient to describe the first expander 14A with reference to FIG. 16.
The expander 14A includes an inverse quantizer 18, an adder 19, a quantization width controller 21, and a memory 20. As a result of the inverse quantizer 18, the input signal supplied from the memory controller 13 is inversely quantized in accordance with a quantization width set by the quantization width controller 21, and then is outputted to the adder 19. The adder 19 calculates the sum of the input signal from the inverse quantizer 18 and an output signal one sample before, which is an output value read out from the memory 20. The thus resulting value is outputted to the subtracter 22 and the D/A converter 15L. Herein, the memory 20 holds a single most recent previous output from the adder 19.
The A/D converter 2, the compressors 4A and 4B, the memory 6, and the expanders 14A and 14B are preferably integrated on a substrate such as a silicon substrate.
The above configuration makes it possible to realize a stereophonic dictating machine at a low production cost.
(EXAMPLE 2)
FIGS. 17 to 20 show a more detailed example of a stereophonic dictating machine according to the above third embodiment of the present invention. The stereophonic dictating machine of this second example is generally the same as that of the first example with the exception that adders 30 and 31 are additionally provided in a recording section and a playback section, respectively. Therefore, in FIGS. 17 to 20, similar elements are indicated by the same reference numbers of FIGS. 12 to 16 and the description thereof will be omitted.
As shown in FIGS. 17 and 18, the digital signals X and Y from an A/D converter 2 are inputted to the adder 30. The adder 30 calculates the sum of the input signals X and Y, and the resulting output (X+Y) is outputted to a first compressor 4A. Herein, the A/D converter 2 is the same as that described in the first example.
As described in the first example, the subtracter 3 subtracts the signal Y from the signal X, and the resulting output (X-Y) is outputted to a second compressor 4B. Accordingly, in the present example, a memory controller 5 writes the compressed data (X+Y)' and (X-Y)' into a memory 6. On the other hand, as shown in FIGS. 19 and 20, the compressed data (X+Y)' and (X-Y)' are read out by a memory controller 13, and subsequently are expanded by first and second expanders 14A and 14B, respectively, thereby obtaining digital signals (X+Y) and (X-Y). The thus obtained digital signals (X+Y) and (X-Y) are outputted to the adder 31. Then, the adder 31 adds the digital signal (X+Y) to the digital signal (X-Y). The resulting output X is inputted to a D/A converter 15L, to thereby playback the original voice signal L. The thus reproduced voice signal L is inputted to an amplifier 16L and then to a speaker 17L, thereby producing a voice sound.
On the other hand, the digital signals (X+Y) and (X-Y) are outputted to a subtracter where (X-Y) is subtracted from (X+Y). The thus resulting output Y is inputted to a D/A converter 15R, thereby reproducing the original voice signal R. The thus reproduced voice signal R is inputted to an amplifier 16R and then to a speaker 17R, thereby producing a voice.
As shown in FIGS. 18 and 20, the compressors 4A and 4B and the expanders 14A and 14B are the same as those described in detail in the first example.
In a manner similar to that of the first example, the compression ratio of the second compressor 4B is higher than that of the first compressor 4A, and the compression ratio of the second expander 14B is higher than that of the first expander 14A.
(EXAMPLE 3)
FIGS. 21 to 24 show a detailed example of a stereophonic dictating machine according to the first embodiment of the present invention. The stereophonic dictating machine of the third example is generally the same as that of the first or the second example with the exception that no adder or subtracter is included in a recording section or a playback section. Therefore, in FIGS. 21 to 24, similar elements are indicated by the same reference numbers of FIGS. 12 to 16 and the description thereof will be omitted.
As shown in FIGS. 21 and 23, an analog voice signal L is produced by a microphone inputting section 1L in response to speech sound, and then the voice signal L is outputted to an A/D converter 2, where it is converted to a digital signal X. Then the digital signal X is compressed using a first compressor 4A. The compressed data X' is written into a location of a selected address in a memory 6 using a memory controller 5. Subsequently, the compressed data X' is read out from the memory 6 by a memory controller 13 as shown in FIG. 23, and then is expanded using a first expander 14A. The expanded digital signal X is converted to the original analog signal L using a D/A converter 15L. Next, the reproduced analog signal L is amplified using an amplifier 16L and then is outputted to a speaker 17L.
Similarly, an analog voice signal R is produced by a microphone inputting section 1R in response to speech sound, and then the voice signal R is outputted to the A/D converter 2, where it is converted to a digital signal Y. Then the digital signal Y is compressed by a second compressor 4B. The thus compressed data Y' is written into a location of a selected address in the memory 6 using the memory controller 5. Subsequently, the compressed data Y' is read out from the memory 6 using the memory controller 13, and then is expanded using a second expander 14B. The expanded digital signal Y is converted to the original analog signal R using a D/A converter 15R. Next, the thus reproduced analog signal R is amplified using an amplifier 16R and then is outputted to a speaker 17R.
As shown in FIGS. 22 and 24, the compressors 4A and 4B and the expanders 14A and 14B are the same as those described in the first and second examples. According to the present example, the configuration can be simplified compared with the first and second examples.
The stereophonic voice recording and playback devices of the present invention can be applied to a communication recording and playback apparatus such as a stereophonic dictating machine.
According to such a communication recording and playback apparatus, it is possible to clearly recognize a position of each speaker compared with the case of a monophonic voice recording and playback device, thereby readily determining who speaks.
In addition, according to the present invention, the data compression ratio can be increased compared with a conventional solid-state stereophonic voice recording and playback device, which makes it possible to make recording and playback duration longer with the same memory capacity.
In addition, according to the stereophonic voice recording and playback device of the present invention, monophonic voice signals can also be recorded and reproduced, thereby expanding the application thereof.
Furthermore, the required number of controllers for the data writing operation and that for the data reading operation can each be reduced to one, which makes it possible to provide a stereophonic voice recording and playback device with a simplified, configuration at a low production cost.
Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.
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A stereophonic voice recording and playback device for stereophonically recording and reproducing voice signals, includes: an adding circuit for receiving a first channel analog voice signal and a second channel analog voice signal, performing orthogonal conversion of the respective analog voice signals, and adding the orthogonally converted signals; an Analog-to-Digital (A/D) converter for receiving the added signal from the adding circuit and converting the added signal to a digital signal; a compressing circuit for receiving the digital signal from the A/D converter and compressing the digital signal; a memory circuit for storing the compressed digital signal; and an expanding circuit for reading out the digital signal from the memory circuit and reproducing a stereophonic signal.
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This is a continuation application of U.S. Ser. No. 10/768,277, filed on Jan. 30, 2004 now U.S. Pat. No. 7,051,606.
FIELD OF INVENTION
The present invention relates to a device and methods for testing pharmaceutical dosage forms such as tablets or capsules. More particularly, the present invention relates to a device and methods for dissolution or immersion testing that limit the ability of a tablet or capsule to move or reorient during testing. Most particularly, the present invention relates to a device and methods that provide for more consistent and/or accurate results in dissolution or immersion testing of tablets or capsules.
BACKGROUND OF THE INVENTION
In pharmaceutical and laboratory research and development, it is commonplace, during formulation development, stability determination, analytical method development, quality control, or otherwise, to ascertain the rate at which a solid dissolves under certain well-defined conditions and/or to predict how it will dissolve in the human system. By way of example, detailed procedures for conducting such testing and specifications for the apparatus employed therein are outlined in the publications of the American Pharmaceutical Association's Drug Standards Laboratory, the United States Pharmacopoeia (“USP”) and the National Formulary. By way of further example, USP 25 <711> Dissolution, which is incorporated herein by reference, describes a test to determine compliance with the dissolution requirements that are stated in the individual monograph for a particular drug. The current USP specifies two alternative apparatuses to be used for the test.
Apparatus 1 (or type 1 apparatus) consists of a vessel made of glass or other inert transparent materials with one of the following dimensions and capacities: for a nominal capacity of 1 liter, the height is 160 mm to 210 mm and its inside diameter is 98 mm to 106 mm; for a nominal capacity of 2 liters, the height is 280 mm to 300 mm and its inside diameter is 98 mm to 106 mm; and for a nominal capacity of 4 liters, the height is 280 mm to 300 mm and its inside diameter is 145 mm to 155 mm. Its sides are flanged at the top. The apparatus further consists of a motor, a metallic drive shaft and a cylindrical basket. See FIG. 17 . It is specified that the shaft and basket components of the stirring element are fabricated of stainless steel, type 316 or equivalent, to the specifications shown in FIG. 1 of the USP. It is further specified that the basket may be coated with a thin layer of gold.
Apparatus 2 (or type 2 apparatus) is essentially the same as apparatus 1 except that a paddle formed from a blade and a shaft is used as the stirring element rather than a basket. See FIG. 18 . USP specifies as follows: the paddle conforms to the specifications shown in FIG. 2 thereof; the distance of 25±2 mm between the blade and the inside bottom of the vessel is maintained during the test; the metallic or suitably inert, rigid blade and shaft comprise a single entity; a suitable two-part detachable design may be used provided the assembly remains firmly engaged during the test; and the paddle blade and shaft may be coated with a suitable inert coating.
In testing, the dosage form is allowed to sink to the bottom of the vessel before rotation of the paddle is started. The USP further provides that a small, loose piece of non-reactive material such as a few turns of wire may be attached to dosage forms that would otherwise float and that other validated sinker devices may be used. Such devices may be formed of a material that is not easily corrodible by the dissolution medium, which may be acidic.
The testing procedure provided for in USP 25 <711> Dissolution is generally as follows. The stated volume of dissolution medium is placed in the vessel specified in the individual monograph for the drug being tested, the apparatus is assembled, and the medium is temperature equilibrated to 37° C.±0.5° C. (to approximate in vivo conditions). Thereafter, the dosage form is placed in the apparatus and the apparatus is operated at the rate specified in the individual monograph. Within the time interval specified, or at each of the stated times, a specimen is withdrawn from the vessel. Often the test is repeated in different vessels and/or with a second, third, or additional dosage form of the drug being tested.
Hence, it is known in the art to entrap dosage forms in a gold coated and/or stainless steel wire basket or in a few turns of non-corrosive wire. In addition, there are commercially available sinkers designed to hold a gelatin capsule in place in a USP 25 <711> Dissolution type 2 apparatus until it dissolves. Examples of commercially available capsule sinkers may be found at www.tabletdissolution.com. However, such devices are not designed to hold a tablet in a specific orientation during testing or to be used in conjunction with conventional dissolution baskets.
It is also known in the art to limit capsule movement during testing. Apparatus 7 of USP 25 <725> Drug Release teaches a holder designed for coated oral extended release tablets. See FIG. 19 . Apparatus 7 specifies the use of a vertically reciprocating spring holder attached to a stainless steel tube and Sample Preparation A, USP 25 <724> Drug Release, allows for the use of a small nylon net bag at the end of a plastic rod. Such holders, however, have drawbacks. For example, the adhesive used to attach the tablets to the rod of the holder can compromise test results by affecting the rate-controlling coating and, thereby, the drug release profile. Additionally, such holders are not useful for tablets with a thin coating or shell because the coating or shell is likely to collapse and dump its content due to the upward and downward strokes of the holder during testing.
Finneran, U.S. Pat. No. 4,669,771, teaches a device for loosely holding a capsule during fluid immersion testing with a plurality of gripping fingers connected at one end which fingers surround a chamber to receive and retain a capsule. However, the device is not suitable for immersion testing of tablets. Fassihi, U.S. Pat. No. 5,412,979, teaches a disk that restrains a dosage form from floating to top of a fluid medium during testing using a vertical shaft and blade apparatus. However, the device is not designed to hold a dosage form in a specific orientation during testing or to be used in conjunction with a dissolution basket. In addition, it is known that differences in hydrodynamic effects corresponding to the relative position of test tablets in test vessels are likely to cause high variability in dissolution testing. See Study Highlights Flawed Dissolution Testing Procedure, Pharmaceutical Technology, October 2003, at 18–19.
The present invention provides a device and methods for immersion and dissolution testing whereby a tablet (by way of example, a controlled release tablet such as an osmotic tablet or matrix tablet) or capsule is held in a specific orientation or substantially fixed position during testing, which can advantageously provide test results that are more consistent between the different tablets (or capsules) and/or vessels used for the testing. For example, when a tablet begins to dissolve, the change in mass can result in a change in the orientation of the tablet either on the bottom of a dissolution vessel, or within a basket, if the movement of the tablet is not limited. A change in orientation of the tablet can result in variability of dissolution characteristics between different tablets of the particular drug being tested and/or vessels used for the testing.
The inventors have found the present invention is also well suited for use with tablets having a preformed passageway, e.g., laser drilled, such as an osmotic tablet with a semi-permeable membrane surrounding the tablet. If a tablet with a preformed passageway(s) reorients during dissolution testing, the test results may be altered if the reorientation interferes with diffusion of the medicament from the passageway(s). For example, if the tablet orients so that the passageway exit is at its bottom, the dissolved contents tend to “dump” out of the exit faster than if the exit is maintained at the top or side of the tablet. By maintaining the exit on the sides (if two exits) and/or on the side or top (if one exit), the contents are prevented from dumping, which allows a steadier rate of diffusion of the contents, including the active drug.
In addition, with respect to controlled-release dosage form tablets such as matrix tablets, the mass of the dosage form diminishes over time. Maintaining the orientation of such a tablet provides for a greater precision in results between different tablets of the particular drug being tested and/or vessels used for the testing.
The subject invention can also prevent tablets or capsules and their contents from sticking to the testing vessel. For example, as tablets dissolve, certain excipients, which may have adherent properties, can cause a tablet to adhere to the inner surface of the vessel. There is a high degree of variability in tablets that adhere to the vessel, which can also cause variability in dissolution between different tablets or capsules of the particular drug being tested and/or vessels used for the testing. By preventing such dosage form adhesion, the subject invention also can provide test results that are more accurate and/or consistent. The subject invention limits variability of location and orientation of tablets and capsules during dissolution testing, which also limits variation from vessel to vessel during testing.
SUMMARY OF THE INVENTION
The present invention comprises a device and methods that provide for more consistent and/or accurate dissolution or immersion test results.
Thus, it is an object of the present invention to provide a useful device that can limit the movement of a dosage form, preferably a tablet, during testing in an immersion or dissolution apparatus.
It is another object of the present invention to provide a useful device that can prevent dosage forms such as tablets or capsules from floating in, or adhering to, testing vessels.
It is still another object of the present invention to provide a useful device that may be used in conjunction with conventional dissolution apparatus without requiring modification of the equipment.
It is a further object of the present invention to provide methods of improving the consistency of dissolution or immersion testing results.
In apparatus terms, these and other objectives are achieved by a device for holding dosage forms such as tablets or capsules during immersion testing comprising: an enclosure surrounding a chamber sufficiently large to receive a dosage form therein; a retaining means; wherein said retaining means engages with said enclosure to limit the movement of a dosage form within said chamber.
In method terms, these and other objectives are achieved by the present invention that provides methods for performing immersion testing comprising the steps of: placing a dosage form, preferably a tablet, into a device for holding the dosage form in a specific orientation, placing said device in immersion testing apparatus and conducting immersion testing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a perspective view of one embodiment of the holder of the present invention.
FIG. 2 depicts a view taken along line 2 — 2 of FIG. 1 .
FIG. 3 depicts a view taken along line 3 — 3 of FIG. 1 .
FIG. 4 depicts a perspective view of an embodiment of the retaining means of the present invention.
FIG. 5 depicts a view taken along line 5 — 5 of FIG. 4 .
FIG. 6 depicts a perspective view of an embodiment of the holder using another embodiment of the retaining means.
FIG. 7 depicts a view taken along line 7 — 7 of FIG. 6 .
FIG. 8 depicts a perspective view of an embodiment of the holder using yet another embodiment of the retaining means.
FIG. 9 depicts a perspective view of another embodiment of the holder of the present invention.
FIG. 9A depicts an alternative embodiment of the present invention.
FIG. 9B depicts a top view of the embodiment depicted in FIG. 9A .
FIG. 9C depicts a side view of the embodiment depicted in FIG. 9A .
FIG. 10 depicts a perspective view of an embodiment of the holder using another embodiment of the retaining means.
FIG. 10A depicts an embodiment wherein the enclosure is rectangular.
FIG. 11 depicts the embodiment of the present invention shown in FIG. 1 in a USP 25 <711> Dissolution type 1 testing apparatus.
FIG. 12 depicts the embodiment of the present invention shown in FIG. 9 in a USP 25 <711> Dissolution type 1 testing apparatus.
FIG. 13 depicts a secondary holder of the present invention.
FIG. 14 depicts the embodiment of the present invention shown in FIG. 1 as it is used in a USP 25 <711> Dissolution type 2 apparatus with the secondary holder shown in FIG. 13 .
FIG. 15 depicts the embodiment of the present invention shown in FIG. 9 as it is used in a USP 25 <711> Dissolution type 2 apparatus with the secondary holder shown in FIG. 13 .
FIG. 16 depicts an embodiment of the present invention wherein the holder is attached to a USP 25 <711> Dissolution type 1 apparatus dissolution basket.
FIG. 17 depicts the basket stirring element of USP 25 <711> Dissolution Type 1 Apparatus.
FIG. 18 depicts the paddle stirring element of USP 25 <711> Dissolution Type 2 Apparatus.
FIG. 19 depicts the oral extended-release tablet holder of USP 25 <724> Drug Release Apparatus 7 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , there is shown a dosage form holder 10 of the present invention. In the depicted embodiment, the holder is comprised of an enclosure 12 , in this case a cylindrical coil, with a first end 14 and a second end 16 , a support member 18 (shown in FIG. 2 ), and a retaining means 20 . The coil enclosure 12 defines a chamber 22 of a sufficient size to accommodate dosage forms of various shapes and dimensions. As explained below, in operation, the retaining means 20 engages with the enclosure 12 to retain a dosage form 100 in a desired position within the chamber 22 . The position of the retaining means with respect to the enclosure may be varied depending on the shape and dimensions of the dosage form to be enclosed.
FIG. 2 depicts a view taken along line 2 — 2 of FIG. 1 . The second end 16 of the coil enclosure 12 has a support member 18 upon which a dosage form such as a tablet 100 may rest. FIG. 3 depicts a view taken along line 3 — 3 of FIG. 1 showing the end 24 of the retaining means opposite the holding portion 26 (shown in FIG. 4 ).
Although the embodiments depicted show the enclosure 12 as having a flat first end 14 , second end 16 and support member 18 , in other embodiments, either or both ends of the enclosure and/or the support member may be rounded rather than flat in order to conform to the shape of the receptacle into which the holder is to be placed. Further, either or both ends of the enclosure and/or the support member may be of any other suitable shape known to those skilled in the art.
In the embodiment depicted in FIG. 1 , the retaining means 20 is independent of the coil enclosure 12 . By independent, it is meant that the retaining means is a separate structure from the enclosure. However, in other embodiments, the retaining means may be integrally formed with the enclosure. In still further embodiments, the retaining means may be otherwise attached to the enclosure by any means known to those skilled in the art including, but not limited to a hinged means. FIG. 4 depicts a retaining means that is independent of the enclosure. FIG. 4 depicts a retaining means 20 that engages with the coil enclosure 12 (not shown) comprising a holding portion 26 that retains a tablet within the chamber 22 (not shown) and an opposite end 24 . FIG. 5 depicts a view taken along line 5 — 5 of FIG. 4 showing the holding portion 26 of the retaining means. In the depicted embodiment, the opposite end of the retaining means (line 6 — 6 of FIG. 4 ) is of the same shape as the holding portion. However, in other embodiments, the holding portion 26 and/or the opposite end 24 of the retaining means may take any suitable shape known to those skilled in the art.
FIG. 6 and FIG. 7 depict an example of a retaining means integrally formed with the enclosure. FIG. 6 depicts a perspective view of one embodiment of the present invention showing a coil enclosure 12 with a first end 14 , a second end 16 and a retaining means 20 . Also shown is the holding portion 26 of the retaining means 20 and the opposite end 24 of the retaining means that is integrally attached to the first end 14 of the coil enclosure 12 . FIG. 7 depicts a view taken along line 7 — 7 of FIG. 6 showing a retaining means 20 and its holding portion 26 integrally attached at the opposite end 24 to the enclosure, in this case the first end 14 thereof. The operation of such a retaining means is explained below.
FIG. 8 depicts another embodiment of a retaining means 20 . Therein is shown a bracket-shaped retaining means 20 that engages with the coil 12 , basket or other enclosure. As explained below, in operating the device, the retaining means 20 can be variously positioned between the first end 14 and second end 16 of the enclosure, depending on the dimensions and/or shape of the dosage form and/or the desired positioning of the dosage form.
Although the figures depict circular coils used to define a chamber for enclosing a dosage form in a desired position, other kinds of enclosures are also within the full-intended scope of the present invention. By way of example, but not limitation, a coil of a rectangular, square or of any other suitable shape known to those skilled in the art may be employed. Further, a mesh or woven basket of a circular, cubical, rectangular or any other suitable shape known to those skilled in the art may be employed.
FIG. 9 depicts another embodiment of the holder 10 of the present invention comprised of an enclosure 12 , in this case a rectangular basket, with a first end 14 and a second end 16 , a support member 18 and a retaining means 20 . The enclosure 12 defines a chamber 22 of a sufficient size to accommodate tablets or capsules of various shapes and dimensions. As explained below, in operation, the retaining means 20 engages with the enclosure 12 to retain a dosage form 100 (not shown in FIG. 9 ) in a desired position within the chamber 22 . The position of the retaining means with respect to the enclosure may be varied depending on the shape and dimensions of the dosage form to be enclosed. In the depicted embodiment, a plurality of apertures or holes 28 in the enclosure allow for varying the position of the retaining means 20 . In this embodiment, the retaining means is independent of the enclosure, i.e., a separate structure forms the enclosure. However, in other embodiments, the retaining means may be integrally formed with the enclosure. Also, the depicted enclosure shows a basket of symmetrical mesh. Alternative embodiments may use asymmetrical or other patterned mesh to form the basket as shown in FIG. 9A . FIGS. 9B and 9C show a top and side view, respectively, of the embodiment depicted in FIG. 9A .
FIG. 10 depicts an example of an embodiment of a holder 10 with a retaining means 20 integrally formed with the enclosure 12 . Also shown is the holding portion 26 of the retaining means 20 and the opposite end 24 of the retaining means that is integrally attached to the first end 14 of the enclosure 12 . The retaining means 20 may be made of flexible material such as wire or plastic or any other suitable material known to those skilled in the art or may contain a resilient portion 20 A that allows the retaining means 20 or, specifically, the holding portion 26 , to be moved in a manner that allows positioning of the dosage form in the holder 10 . By way of example, the retaining means may be spring loaded so that it can be stretched to position different size dosage forms within the holder 10 . The operation of such the retaining means of the invention is further explained below.
FIG. 10A shows an embodiment wherein the enclosure 12 is made of mesh wire screen, which is shaped into a rectangle with a joint soldered. The two ends of the holder have supports 14 a and 14 b that may support the holder. The supports may be made of stainless steel or any suitable material known to those skilled in the art.
In operation of one embodiment of the device, the dosage form such as a tablet 100 may be inserted into the chamber 22 so as to rest on the support member 18 of the enclosure 12 . After the dosage form is inserted into the chamber 22 , the retaining means 20 may be engaged with the enclosure 12 such that the holding portion 26 thereof prevents passage of a captive dosage form 100 out of chamber 22 and so as to retain loosely (or in any manner desired) the dosage form in a horizontal, vertical or other desired position.
In embodiments where the retaining means is integrally formed with the enclosure, the holding portion of the retaining means may, if necessary, be removed from the chamber within the enclosure prior to insertion of the dosage form. Once the dosage form is inserted into the chamber, the retaining means is bent or otherwise engaged with the enclosure such that its holding portion prevents passage of a captive dosage form out of the chamber and limits the movement of the dosage form. In method terms, once the dosage form, preferably a tablet, is oriented in a desired position within the enclosure, the remaining steps for dissolution or immersion testing may be conducted as desired.
The components of the holder are preferably fabricated of stainless steel, plastic or other material (or any combination thereof) that is not easily corrodible by the dissolution medium, which may be acidic. In the case of a coil enclosure or the like, the material of the coil may also be chosen to provide enough resilience to permit it to be easily collapsed to allow the retaining means to engage greater or fewer rings of the enclosure so as to allow a more precise fit with the retaining means and to adjust to the shape and/or dimensions of the dosage forms being tested. In embodiments where the retaining means is integrally or otherwise attached to the enclosure, the retaining means may be constructed such that it may be moved in and out of position and able to withstand repeated use.
Because the specific gravity of the dosage form may be less than the specific gravity of the immersion medium (which would also allow the dosage form to float in the immersion medium), the holder may also serve as a sinker. Where such is the case, the components of the holder can be constructed of materials such that the overall device will have a density greater than that of the dissolution medium(s) used. Other means to keep the holder submersed in the dissolution medium are also within the full-intended scope of the present invention. For example, the device may be submersed by a magnetic means or any other means know to those skilled in the art.
FIG. 11 and FIG. 12 depict a cross-sectional view of the embodiments of the present invention depicted in FIG. 1 and FIG. 9 , respectively, used in dissolution apparatus comprised of a vessel 110 , shaft 120 and basket 130 . The embodiments depicted are of a size and shape such that they nest within a dissolution basket of the dimensions specified in USP 25 <711> Dissolution and/or in a manner that its support member 18 may rest on the bottom of the basket 130 and the enclosure 12 is supported by the inside walls of the basket such that the holder 10 cannot topple over. In addition, the height of the holder 10 depicted is less than the height of the basket 130 . Other means of limiting undesired movement of the holder within its receptacle known to those skilled in the art are also within the full-intended scope of the present invention. In addition, it is contemplated that the holder may also be used such that the first end of the enclosure may rest on the bottom of the basket.
As heretofore explained, the present invention may be used with commercially available USP 25 <711> Dissolution type 1 baskets to facilitate the application of the invention without requiring modification to commercially available equipment. In addition, the device may be specially designed to accommodate the shape and dimensions of oversize, undersize or unique sized dosage forms.
In addition, the present invention may be adapted for use with other apparatus including, but not limited to, such as or similar to that described in USP 25 <711> Dissolution including, but not limited to, that known as the “type 2 ” or “paddle” apparatus. FIG. 13 depicts a secondary holder 38 that may be useful in the practice of such an embodiment comprised of a base 42 and an engaging means 40 . In this embodiment, the secondary holder 38 may engage the dosage form holder via the engaging means 40 . The secondary holder 38 depicted is circular and is configured so that it may be placed on the bottom interior section of a conventional dissolution vessel without requiring the modification of commercially available dissolution equipment. In other embodiments, the secondary holder may be of any shape and/or size known to those skilled in the art. In certain embodiments, the holder may be engaged with the secondary holder by use of an engaging means that is magnetic. However, other engaging means known to those skilled in the art are also within the full-intended scope of the present invention.
The secondary holder 38 may be configured as a separate or a unitary member integral with the holder 10 (not shown). The secondary holder 38 is preferably fabricated of stainless steel, plastic or other material (or any combination thereof) that is not easily corrodible by the dissolution medium, which may be acidic. The secondary holder 38 may also be fabricated of materials such that it will have a density greater than that of the dissolution mediums used so that it will rest on the bottom of the testing vessel to be used. However, the secondary holder 38 may be constructed of any suitable materials known to those skilled in the art.
Referring now to FIG. 14 and FIG. 15 , it is shown that the secondary holder 38 centers the holder 10 for the dosage form such as a tablet 100 in the vessel 110 and maintains the position of the holder 10 throughout testing using a USP paddle (formed by a blade 140 and shaft 150 ) or the like. Although in this embodiment the dosage form 100 is held in the center of the bottom of the vessel 110 , if it is desired to test the dosage form in an “off center” or other position, the secondary holder may be configured and/or designed accordingly.
FIG. 16 depicts one example of an embodiment of the present invention wherein the holder 10 inside the dissolution basket 130 and the dissolution basket is attached to the rotating shaft 120 . In such embodiments, the holder may be removably attached and/or permanently attached to the basket.
All of the above referenced patents are incorporated herein by reference. While this invention has been described with reference to specific embodiments thereof, it is not limited thereto. Instead, the claims which follow are intended to be construed to encompass not only the forms and embodiments of the invention shown and described, but also such other forms and embodiments and such variants and modifications thereof as may be devised by those skilled in the art without departing from the spirit and scope of the present invention as may be ascertained from the foregoing description and accompanying drawings.
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The present invention comprises a device and methods for dissolution or immersion testing and, in particular, a device and methods that improve the consistency of test results by limiting the ability of pharmaceutical or other dosage forms to move or reorient during testing.
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RELATED APPLICATION(S)
This application claims priority from and incorporates herein by reference the entire disclosure of U.S. Provisional Application Ser. No. 60/248,265 filed Nov. 14, 2000.
TECHNICAL FIELD
The present invention relates to the configuration of optical circuits, and more particularly, to the use of a multi-token control mechanism to configure optical circuits on demand.
BACKGROUND OF THE INVENTION
The insatiable appetite for Internet connectivity and network applications drives the current explosion of network traffic volume worldwide. It is expected that this exponential growth of traffic volume will continue in the foreseeable future. Optical fiber communication technology based on Wavelength Division Multiplexing (WDM) has been employed as the major means to cope with the traffic volume growth. While WDM technology has already revolutionized the backbone network by enabling unprecedented increases in the leveraged capacity of a single fiber, a parallel paradigm shift is now taking place in the metropolitan network.
One of the most critical challenges in designing today's access and metropolitan networks is the fact that bandwidth demands have been consistently exceeding the most aggressive network planning predictions. In addition, the individual user's traffic burstiness makes static bandwidth reservation (e.g., SONET/SDH like) neither bandwidth efficient nor adequate to delay sensitive traffic. This situation has generated an increasing interest towards all-optical networks that are capable of allocating network resources, i.e., bandwidth, in a dynamic way. Such networks must be able to reserve the necessary bandwidth on-demand to allow the transmission of a user's traffic burst. Once the burst transmission is completed, the reserved bandwidth is promptly released to be made available to other burst transmissions.
In order to be of practical use, the bandwidth on-demand concept requires few but fundamental features. Three of the features are:
fast set-up time of the optical circuit (or lightpath); fair blocking probability irrespective of the lightpath span (or the number of fiber lines the lightpath is routed through) good bandwidth efficiency, i.e., the fraction of reserved bandwidth actually used to transmit data.
To understand how challenging it is to achieve these three features at once in the same architecture, one must observe that user requests for a lightpath are unpredictable and may occur simultaneously at distinct and geographically separated nodes. As a result, concurrent lightpath requests will compete to secure common resources, i.e., the available wavelengths in the network. This may result in a number of reservation attempts being failed as they are blocked by other lightpath requests that book the resources first. In this scenario, it is thus possible to incur in long set-up times and unfair blocking probabilities that are a function of the lightpath span. Lightpaths with longer spans are more likely to be blocked since they require successful wavelength reservation on each and every fiber line they are routed through.
Solutions so far proposed to solve the problem of routing and wavelength assignment (RWA) to establish lightpaths dynamically in a WDM ring can be categorized as centralized approaches and distributed approaches. With a centralized approach, the source node sends the request for a lightpath to a special node called controller. The controller keeps track of the available network wavelengths and serves the node requests on a first-come-first-serve (FCFS) basis. The resource contention is resolved at the controller. On a unidirectional ring, latency of the signaling required between the source and the controller to set up and eventually tear down the lightpath is proportional to the ring latency, i.e., round trip propagation time within the ring, and may considerably delay the set-up time and reduce bandwidth efficiency in metro applications.
With a distributed mechanism, every node solves the RWA problem for its own newly requested lightpaths. One way to achieve this objective is to allow every node to keep track of network-wide wavelength availability. The RWA problem is solved based on shared global information. In another approach, each node makes use of a routing table for each wavelength which specifies the next hop and the cost associated with the shortest path to each destination on this wavelength. Since different nodes may concurrently try to assign the same wavelength to distinct lightpath requests, both approaches require at least one round trip time from source to destination to be assured that their reservation was completed successfully. In a unidirectional ring this time equals the ring round trip time.
SUMMARY OF THE INVENTION
The present invention overcomes the foregoing and other problems with an optical network consisting of a source node and a destination node which are interconnected by a plurality wavelength, wherein each of the plurality of the wavelengths is associated with a particular channel. A token is associated with each of the plurality of wavelengths and indicates the availability of the wavelengths for supporting a lightpath. The source node is configured to store a request for a lightpath between the source node and a destination node. Upon receipt of a token at the first node indicating an available space within the wavelength associated with the token, a request is selected from the queue using a best fit window protocol. A connection is then established responsive to the selected request between the source node and the destination node.
The selection process would consist of determining whether any requests within the queue having expired soft deadlines and selecting a largest request having an expired soft deadline which will fit within the available space of the wavelength for connection if any exist. If no soft deadline expirations are present, a largest request which will fit within the space available on the wavelength is selected. The selected request is used to establish a connection.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the method and apparatus of the present invention may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings wherein:
FIG. 1 generally illustrates the implementation of the system and method of the present invention;
FIG. 2 illustrates source and destination nodes within an optical ring network;
FIG. 3 illustrates the application of the best fit window approach of the present invention;
FIG. 4 is a flow diagram illustrating the method of the present invention;
FIG. 5 illustrates the achievable node throughput versus the average lightpath duration in a multiple ring latency for a centralized and distributed lightring analytical model;
FIG. 6 illustrates the relationship between response time and throughput when using different sizes of a best fit window; and
FIG. 7 illustrates achievable throughput for different burst sizes when using a different number of channels.
DETAILED DESCRIPTION
Referring now to the drawings, and more particularly to FIG. 1 , where there is provided a general illustration of the system of the present invention. The Lightring architecture of the present invention resorts to a unique distributed multi-token based control wherein access to each wavelength 10 (channel) is controlled by a wavelength specific signaling-token 15 that is circulated among each node 20 on a ring 25 in a round robin fashion. For each data wavelength, a control message or token is continuously circulated among the nodes using the control channel. Tokens 15 regulate the access to the corresponding wavelength 10 and inform the source of the ring 25 available resources (wavelengths). Tokens 15 bear resource availability information and broadcast this information to each node 20 in the ring network 25 . This enables each node 20 of the ring network 25 to have an updated view of network resources. Upon reception of a token 15 , a source node 20 a with an outstanding lightpath request checks the available resources on the wavelength 10 associated with the token 15 and verifies if the outstanding lightpath can be set up on that wavelength. If so, the token 15 is updated and passed onto the adjacent downstream node to inform all the other nodes 20 that a lightpath has been established and some resources have been reserved on that wavelength. A lightpath is set up between two nodes 20 on a given wavelength only when a token 15 is acquired by a source node 20 a . Similarly, for lightpath take-down, the token corresponding to the wavelength of the lightpath will be updated by the source to inform the other nodes of what resources have been freed. While circulating along the ring 25 , tokens 15 broadcast lightpath status information on other connections to each node 20 on the ring 25 .
Referring now also to FIG. 2 , the network under consideration is a single fiber ring network 25 that connects N nodes 20 . The network makes use of W data channels and one control channel, for a total of W+1 wavelengths 10 . Each wavelength supports one data channel. The optical signal on the control channel does not go through the node 20 and it is separately handled by a control receiver 30 and a control transmitter 35 . For each data channel a node 20 has one fixed control transmitter 30 , one fixed control receiver 35 and one optical switch 40 . This architecture allows the node 20 to transmit and receive message independently (and simultaneously) on any data channel. The on-off switches 45 within the optical switch 40 are used to control the flow of optical signals through the node 20 and prevent signal re-circulation in the ring 25 . A transmission buffer 55 is also provided at each node 20 to queue the generated packets prior to their transmission into the ring 25 . The nodes 20 activities are regulated by an electronic controller 60 that determines the state for each on-off switch 45 , the message transmission time, the wavelength used, and the reception of the incoming messages. The electronic processing is done in parallel while the optical signal propagates through the fiber delay line 65 that connects the splitter 50 to a demultiplexer 70 .
Once transmitted by the source node 20 a , the message is removed from the network by the destination node 20 b . Any uncollected section of the message, due to the setup of the optical switch at the destination node 20 b , will make a round trip and be collected by the source node 20 a . An optical copy of the message is obtained at every node 20 using a splitter 50 , thus realizing a “broadcast and select” system. Only the intended destination(s) of the message actually receives the message.
Referring now back to FIG. 1 , in the present architecture, access to each wavelength 10 is controlled by a dedicated token 15 that is cyclically circulated among the nodes. Each data channel (i.e., wavelength) is associated with one token that is circulated among the nodes 20 in the control channel and regulates the access to the corresponding channel. Thus, a total of W tokens 15 are available in the ring. A lightpath between a source node 20 a and a destination node 20 b may be set up and torn down only when a token 75 is acquired by the lightpath source node 20 a . The token 15 is used to broadcast the wavelength status to all nodes 20 in a ring 25 and indicate whether there is available space on a wavelength 10 . Since only one node 20 at a time is allowed to make a reservation on each wavelength, the protocol of the present system achieves a “tell-and-go” reservation mechanism that is always successful. While circulating along the ring 25 , tokens 15 broadcast the source 20 a and destination node 20 b of the newly established lightpath to all nodes 20 of the ring 25 so that no other node 20 will attempt to set up a lightpath on the same wavelength 10 that overlaps in space with the one being established. Global lightpath status information of the moment is thus maintained on each node 20 . This information can be stored in a memory (not shown) associated with each node 20 .
If a strict first come first serve (FCFS) service policy is used on the message queue of each node 20 , the system inclines to penalize the lightpath requests with longer spans when the offered load becomes high due to the space limit on the ring regarding a channel. Therefore, lightpath requests with long spans will hold up all the traffic behind it in the queue. Based on this observation, a Best-Fit Window (BFW) mechanism is used to achieve better network throughput.
Contrary to all conventional wavelength assignment algorithms whereby an available (somehow optimal) wavelength is sought for each given lightpath request, the LightRing protocol seeks the lightpath request in the Beat-Fit-Window (BFW) of the transmission queue that optimally fits the available space of the network on a given wavelength (identified by the arriving token) at the arrival time of the token. Any lightpath request in BFW of the transmission queue is a possible candidate to be transmitted based on the result of selection. The bandwidth efficiency achieved by the proposed reservation mechanism is proportional to the number of requests that the reservation mechanism can choose from, thus it is proportional to the size of BFW. Complexity of the LightRing reservation mechanism is proportional to the size of BFW and not a function of the number of wavelengths (most of the existing reservation mechanisms have complexity that is proportional to the number of wavelengths). The LightRing reservation mechanism thus scales well when the number of wavelengths increase.
When a token 15 arrives, the best-fit message, which is the message with the longest span that can fit into the available space on the channel corresponding to the token, will be chosen and transmitted. Thus, as seen in FIG. 3 , where message requests 80 – 100 are waiting in the queue 105 , and a space 110 having a length N is available in a requested channel, message request 100 is selected for the space 110 because it is the request with the longest span capable of fitting in the available space.
In order to avoid starvation and guarantee fairness for the requests with different span lengths, a soft deadline is applied to each lightpath request so that the request will be dropped outside of BFW mechanism if the waiting time of the request is longer than a certain value. To maintain fairness of the system, requests are not dropped in the BFW mechanism. Instead, a FCFS protocol is applied to a request that has reached its soft deadline and the request is transmitted in the next available space. In other words, once a request gets into BFW, it has to be transmitted sooner or later.
Following is an explanation of each variable used in the protocol description.
r i : ith lightpath request,
R T×O : {r i |r i in transmission buffer of a node};
R BFW : {r i |r i ∈R T≠/Q , 0≦BFW};
R T≠Q−BFW : {r i |r i ∈R T≠/Q , r i ∉R BFW };
t: current time;
t i (a) : arrival time of r i in R T≠Q (the time that r i is inserted into the transmission queue);
t i (S) : beginning of the service time of r i (the time r i is removed from the transmission queue);
t j (t) : arrival time for token j;
t i (q) : time spent by r i in R T≠Q ;
t i (w) : time spent by r i ; in R BFW ;
e (w) (t): estimated average time spent by r i in R BFW as the function of t;
d 7 : soft deadline for serving lightpath request r i ;
d (w) (t): soft deadline for r i leaving R BFW ; this value is based on the average time spent in the BFW.
R LATE : {r i |r i ∈R BFW , t i (w) >d (w) (t)};
l j (i): the number of available hops left when r i is placed into the space available on channel j; negative number indicates the number of hops that r i exceeds the available space gap.
Fit(R,λ j ): {r i |r i ∈R, l j (i)≧0};
BestFit(R,λ j ): {r i |r i ∈R, l j (k)≧l j (k)≧l j (i), for ∀r k ∈R−r i };
FCFS(R): {r i |r i ∈R, t j (a) , for∀r k ∈R−r i };
The following rules are applied to the protocol:
(1) only r i in R BFW can be served upon a token's arrival; (2) only r i in R T×Q−BFW may be dropped due to the soft deadline applied, so that once r i gets into R BFW , it has to be served eventually; (3) arriving requests are dropped when no space is available in transmission buffer;
The protocol used on a node can be described according to the following pseudocode. However, it should be realized that other implementation of code are possible.
1. Upon arrival of token j, t=t j (t) −
set up lightpath for request r i
If (Fit(R LATE , λ j )≠Φ){
r i =FCFS(fit(R LATE , λ j )) release token j with current lightpath info transmit r i
} else if(Fit(R BFW , λ j )≠Φ{
r i =BestFit(R BFW , λ j ) release token j with current lightpath info transmit r i
} else
pass token j to next node;
2. Upon beginning of servicing of arrival of r i , t=t i (j)−
i) remove r i from R T≠Q and R BFW ; ii) set e (w) (t)=βe (w) t i−1 (j) +(1−β)t i (w) , where β is a system parameter of estimator e (w) , with value less than 1 but close to 1; iii) set d (w) (t)=αe (w) (t), where
a = d ( w ) ( t ) e ( w ) ( t )
is the margin above average value for r i spent in R BFW ·α is greater than 1 but close to 1;
iv) drop requests that past the soft deadline, which are {r i |r i ∈R T×Q−BFW , t i (q) >d (q) −e (w) (t)}.
There are two fairness issues in the system of the present invention. The first issue is the fairness for the lightpath requests with different lengths in time. Since the incoming lightpath request has exponential distribution on duration, this fairness issue is resolved automatically. This is true even when BFW is used because the request selection is totally independent from lightpath duration.
The second issue is the fairness for the lightpath requests with different spans (or distances) on the ring. When FCFS policy is used, this fairness issue is also resolved automatically due to the uniform traffic distribution. But when BFW is used in the network, the simulation results confirm this fairness is no longer guaranteed. This is simply due to the fact that we do not randomly select requests in BFW regarding span length.
The way we tackle this problem is to apply a soft deadline d (w) (t) to each lightpath request in BFW, where d (w)(t) is described above as a common filter with system parameter α and β. Any request with the time spent in BFW greater than d (w) (t) is considered late and will be transmitted in the fashion of FCFS. The closer is the value of α to 1, the tighter is the constraint and in turn more observed is the fairness. The closer the value of β to 1, the slower the common filter reacts to input change.
If a hard deadline is applied to each lightpath request, the overdue request has to be dropped no matter it is in BFW or not. Because of the non-random selection of request in BFW for transmission, if the overdue request is dropped in BFW, the blocking probability will no longer be the same for the requests with different lengths of span. Therefore the fairness can not be maintained any more. Based on this observation, we change to drop the overdue request right outside of BFW to maintain a soft deadline d q . Since the estimated average waiting time e (w) (t) is kept for record anyway, d q −e (w) (t) can be used to check if we need to drop the request right outside of BFW when BFW has an empty spot to be filled. Therefore, in order to achieve the fairness o blocking probability only a soft deadline d (q) can be applied.
Referring now to FIG. 4 , there is illustrated a flow diagram generally describing the process for assigning a request to a provided span within a channel. A token requesting establishment of a lightpath between a source node and a destination node is received at step 200 . The request stored at step 205 within the nodes queue. An indication of an available span is received at step 210 from another token. Inquiry step 215 determines whether any soft deadlines for any requests within a node queue have expired. If so, the first received request which will fit within the span and has an expired soft deadline is assigned to the span at step 220 .
If inquiry step 215 determines that no request has exceeded their soft deadline, the span is compared to each message within the queue to select a best fit at 225 . A best fit will comprise the request with the longest span which will fit within the available span length. The selected message is assigned to the span at step 230 so that a lightpath may be established.
Analytical Models
In order to see the intrinsic difference between the normal centralized WDM ring with dynamic finite duration lightpath requests and the distributed architecture proposed herein, a model for each case is presented. Due to the complexity of modeling LightRing with BFW>1, we only consider the case when BFW=1 and provide the simulation result for BFW=40.
Our analysis extends the blocking probability model described in R. A. Barry and P. A. Humblet, “Models of Blocking Probability in All-Optical Networks with and without Wavelength Changers,” IEEE JSAC, Vol. 14, No. 5, June 1996, which is incorporated herein by reference, to capture the characteristics of dynamic traffic with finite duration. Barry's model introduces the qualitative behavior of the traffic for circuit-switched all-optical networks which can be used to calculate the blocking probability along a path. Yet the model does not cover the situation that lightpaths can be dynamically established and taken down. The major variable Barry's model include P 1 , the probability a lightpath ends and drops out at a node, and P n , the probability a lightpath starts at a node on an available wavelength. The result is
P n = ρ P 1 1 - ρ ( 1 - P 1 ) ( 1 )
where ρ is the utilization. The blocking probability without wavelength converter is
P 1 =|1−(1 −P n ) R | F (2)
where H is the number of hope of the lightpath and F is the number wavelengths in each fiber.
In the case of unidirectional WDM ring, P 1 is 1/N. In order to obtain the achievable throughput regardless the duration of the lightpaths, we can use the iteration technique due to the fact that y=P b 1 −P b , where P b 1 is the result of iteration using P b , is a monotonous function. Under maximized network load, here are the steps to find the blocking probability P b in interaction working on y−P b plan:
1. set networth load d=1, P b0 =0 and P b1 =1; 2. ρ0 =d(1−P b0 ); ρ1=d(1−P b1 ); 3. get new P b0 1 and P b1 1 using Esq. 1 and 2; 4. y0=P b0 1 −P b0 1 ; y1=P b1 1 −P b1 ; 5. connect the point (P b0 , y0) and (P b1 , y1) with a straight line and find out the P b that the line across the P b axis; 6. y=P b 1 −P b1 where P b 1 found using Eq. 1 and 2; if y has the same sign as y0, P b0 is replaced by P b , otherwise P b1 is replaced by P b ; 7. go back to step 2 until |y| is less than a certain predetermined value;
Due to the establishment cost of lightpath with finite duration under both distributed and centralized control mechanism, the real achievable throughput (thr) becomes
thr=E[η α ](1 −P b ) (3)
where E[η(α)] is the average cost factor between the virtual throughput (1=P b ) and the real throughput (thr) for the average lightpath duration α.
Centralized Approach
With a centralized control mechanism, the source node sends the request for a lightpath to a special node called the controller. The controller keeps track of the available network wavelengths and serves the nodes' requests on a FCFS basis. Once the requested lightpath is assigned a wavelength, the controller instructs the nodes that will wet up the optical add-drop multiplexers to establish the lightpath. The extra cost for setting up lightpath is always one round trip delay. Therefore assuming the burst message length has exponential distribution, the cost factor is
E [ η ( α ) ] + ∫ 0 ∞ t D + t 1 a ⅇ - t / a ⅆ t ( 4 )
where D is the ring latency.
Distributed Approach
In the proposed distributed Lightring protocol, the extra cost resides at the extra waiting time for the same token to come back to the source node when take down the lightpath. This is based on the assumption that no switching time is needed during the lightpath setup. Therefore the total time the lightpath in place is the multiple time of round trip delay that is immediately greater than the real lightpath duration α.
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Performance Results
The performance results presented are produced from the simulation model implemented in C++ and the analytical model described above. Unless indicated explicitly, the network under consideration is a WDM ring with 32 wavelengths and 16 nodes evenly distributed over 80 km of fiber. Each wavelength supports a fixed transmission rate of 10 Gbps. For demonstration purposes, we assume the network traffic has Poisson arrival rate and lightpath duration is exponentially distributed. Traffic is uniformly distributed, meaning that the source and the destination nodes of a newly generated message are randomly chosen.
FIG. 5 depicts the achievable node throughput vs. the average lightpath duration in the multiple of the ring latency for the centralized and distributed LightRing analytical model presented above and the simulation result of the LightRing protocol with BFW=1 and BFW=40. The distributed model has BFW=1, it fairly closely matches the simulation result with BFW=1. As we can see when burst is not too large, LightRing clearly outperforms the centralized approach. Theoretically, the two curves will converge when the burst size approaches infinity. Also when BFW size increases, bandwidth efficiency is also improved.
FIG. 6 shows the relationship between the response time and throughput when using different sizes of BFW. Response time is defined as the summation of the waiting time in queue and the transmission time. The average message length is 10 Mbit. The performance improvement of using larger BFW occurs under medium to heavy load. The improvement is the most obvious when BFW first picks up and becomes less obvious later.
As FIG. 6 shows, response time and control complexity can be traded for bandwidth efficiency by varying the BFW size. It is also noticed that when the network load is not too heavy, the response time can be well below the summation of the ring latency and the average burst duration (in this case, it is 1.4 msec). In other words, the time to establish a lightpath can be well below the ring latency as opposed to the case for existing centralized and distributed reservation mechanisms that needs at least the ring round trip time.
Based on the LightRing protocol, FIG. 7 shows the achievable throughput for different burst sizes when using a different number of channels. The result is based on the analytical model described above. The total bandwidth is fixed to 80 Gbps, so that when the number of channels increases, the transmission rate for each individual channel will decrease. That implies lower costs for the transmitter and receiver, assuming cost has more than linear growth while transmission speed increases. But more importantly FIG. 7 indicates better bandwidth efficiency when the number of channels increase. This is due to the fact that a node acquires tokens more frequently and more space to set up a lightpath.
Finally, the blocking probability for the lightpaths with a different number of hops is completely fair in LightRing due to the uniform traffic, and the fact that late messages are removed from the transmission queue only outside of BFW.
The LightRing architecture was presented in which a multi-token based reservation mechanism is used to set up lightpaths on-demand. By performing a tell-and-go reservation of the wavelengths, the LightRing approach yields fast set-up time and efficient bandwidth utilization even in presence of relatively short bursts of data, e.g., bursts whose transmission time is 1 ms in a 80 km ring.
Among other interesting features, the LightRing architecture is compatible with optical packet switching, and its performance improves with the number of wavelengths, consistently with the current trend of optical technologies. Complexity of the reservation mechanism is not a function of the number of wavelengths, and can be varied to trade response time for bandwidth efficiency. Finally, the LightRing approach is compatible with emerging protocols for bandwidth reservation in the optical layer, e.g., MPλS, and yields fair blocking probability irrespective of the lightpath span.
The previous description is of a preferred embodiment for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is instead defined by the following claims.
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A system and method for configuring lightpaths within an optical circuit wherein the source node stores requests for a lightpath between the source node and the destination node. Upon receipt of a token at the source node indicating an available space within a wavelength, the source node selects a request stored within the queue based upon a best fit window protocol. A lightpath is then established between the source node and the destination node responsive to a selected request.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part U.S. National Stage filing from International Application No. PCT/AU02/00559 filed May 3, 2002 and published in English as WO 02/089957 on Nov. 14, 2002, which claimed priority from Australian Application SN PR4902 filed May 10, 2001, which applications and publication are incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to the treatment of waste products including solid and liquid domestic and human waste. The invention has particular but not exclusive application for onsite treatment of domestic sewerage.
PRIOR ART
[0003] The managing and treatment of domestic sewerage and other waste is a growing problem facing cities and other populated areas. In lightly populated areas there is often a lack of appropriate sewerage facilities. If the sewerage is not appropriately treated, it can contaminate water supplies and subsequently affect the health of the inhabitants.
[0004] One approach to the problem has been the development of onsite treatment systems that minimise the amount of waste leaving a property or dwelling. In general however many onsite treatment systems have relatively high operating costs and require regular servicing.
[0005] A large number of onsite treatment systems for sewerage such as a septic tank involve an anaerobic digestion stage. Odours produced from anaerobic digestion can cause problems. Furthermore the initially treated sewerage requires more extensive subsequent treatment before it can be discharged. Septic systems also require periodic pumping out of the residual sludge. In addition septic systems are becoming less popular with regulatory authorities because of their potentially harmful effect on the environment. Many alternative systems developed to replace septic systems have a range of problems including reliability.
[0006] With aerobic treatment systems the sewerage is aerated usually with the use of blowers or other mechanical means of aeration. The blowers and other mechanical means require maintenance and their use increases operating costs. Several aerobic treatment systems have been developed. An aerobic treatment system described in AU652879 involves passing the waste through a bed of suitable filtration material containing a population of composting worms or microbes. The filtration bed of this system is relatively large in area and all liquids and solids pass through the bed. The mixture of liquid and solid waste serves as the substrate for the microbes and worms. The solids either remain in the device causing problems at a later stage or have to be manually removed from the bed. The effluent from this process is of relatively poor quality.
SUMMARY OF THE INVENTION
[0007] The basis of the present invention was the development of a separating means to separate solid and liquid waste for separate treatment. The separating means has a geometrical shape that allows substantially all of the solid waste to fall off an outer surface and the majority of the liquid waste to flow on the surface and into a liquid collection means. The shape of the separating means preferably allows liquid waste to flow along the outer surface by means of surface tension.
[0008] In one aspect the present invention provides a separating means for separating liquid and solid waste, wherein the separating means has a substantially non porous inclined surface with a curved lower outer edge to allow solid waste to fall off the separating means while liquid waste moves around the curved lower outer edge.
[0009] The outer surface is preferably an inclined surface with a curved lower outer edge. The degree of inclination of the outer surface preferably enables the separating means to be substantially self cleaning. The preferable angle of inclination of the outer surface is an angle that facilitates the downward movement of particulate and liquid waste. The angle of inclination is preferably between 10 and 40 degrees, more preferably between 20 and 30 degrees from the horizontal axis. The lower curved outer edge is preferably a convex curved surface curving inwardly and under the inclined surface. The curve of the outer edge preferably facilitates the falling off of particulate waste but allows liquid waste to move around the outer edge.
[0010] The separating means may be an inclined wall adjacent a waste discharge outlet and having a curved lower edge that extends, at least in part, substantially horizontally under the inclined wall. Hence, the separating means may be a closed structure having a substantially horizontal base or it may be an open structure having a substantially horizontal inward projection from its side wall(s).
[0011] The separating may have one inclined surface. For example, the separating means may be substantially in the shape of a cone or a hemisphere. Alternatively, the separating means may have a plurality of inclined surfaces. For example, the separating means may be substantially in the shape of a pyramid or prismoid. Any of these geometric shapes may be either with or without a base, as mentioned above.
[0012] The separating means preferably substantially overhangs the liquid collection means so that liquid flows around the curved lower edge of the outer surface and drips into the liquid collection means while particulate matter falls off the outer surface as the matter moves around the curved lower edge. The liquid collection means may be in the form of, for example, a tray or a chamber.
[0013] Preferably, the separating means includes a flange on its lower edge for directing liquid waste into the liquid collection means. Preferably, the flange extends downwardly from a substantially horizontal part of the curved lower edge.
[0014] The inclined surface(s) is substantially non porous. By “substantially non porous”, it is contemplated that in some forms of the invention, the surface may have a degree of porosity such that some liquid can pass through directly to the liquid collection means. Notwithstanding, the majority of liquid will still be separated by moving around the curved lower outer edge. However, the term “substantially non porous” may also mean, in some forms, that the inclined surface is completely non porous.
[0015] In a preferred embodiment the separating means is a substantially non-porous separating cone locatable with its apex uppermost and with the apex adjacent to a waste discharge and a convex lower curved surface that turns inward to form the base wall.
[0016] The separating cone is preferably adaptable to be retrofitted to an existing treatment system.
[0017] In another particularly preferred embodiment, the separating means comprises two substantially non porous inclined surfaces, each having curved lower outer longitudinal edges, and sharing a common upper edge, which defines a top edge of the separating means. A separating means in this form has the advantage of simpler and cheaper construction.
[0018] Preferably, each of the inclined surfaces is elongate and shares a common longitudinal upper edge. An advantage of elongate surfaces is that the surface area of the separating means is increased without increasing the overall height. With a greater surface area, greater separating efficiency can be achieved with a correspondingly increased capacity for receiving waste material.
[0019] Preferably, the separating means described above further comprises a longitudinal flange along each of the curved lower longitudinal outer edges, the longitudinal flanges being positioned for directing liquid waste into a liquid collection means, such as a tray beneath the flanges.
[0020] Preferably, the separating means described above has a first end locatable adjacent a waste discharge outlet and a second end locatable distal to the waste discharge outlet. Hence, waste from the discharge outlet flows longitudinally along the separating means while simultaneously flowing down from the top edge to the lower outer longitudinal edges, thereby increasing separating efficiency by increasing the surface area exposed to the waste mixture.
[0021] Preferably, each of the inclined surfaces is tapered towards the second end of the separating means (which is distal to the waste discharge outlet), such that the second end is smaller in cross-section than the first. An advantage of this configuration is that it reduces the surface area of the separating means in areas where the velocity of waste is relatively low. This reduces the tendency for solid build up on the separating means.
[0022] Preferably, the separating means has a height dimension of less than 200 mm. Typically, separators known in the prior art require a relatively large height dimension, which impacts on the overall compactness of systems containing such separators. With the novel separating means of the present invention, a relatively small height dimension is achievable whilst maintaining excellent separating efficiency.
[0023] In another aspect, the present invention provides a waste treatment system including a decomposition chamber having an inlet, said decomposition comprising:
[0024] a separating means as described above; and
[0025] a solid waste treatment means and a liquid waste treatment means.
[0026] The separation means, solid waste treatment means and liquid waste treatment means are preferably arranged in relative close proximity with each other to provide a compact treatment apparatus.
[0027] The decomposition chamber is preferably circular in cross section to provide maximum usage of space within the chamber and house the components in a compact manner.
[0028] The treatment system may be modular with a plurality of units arranged to handle larger amounts of waste. Alternatively each unit may be increased in size to cater for larger amounts of waste.
[0029] The waste chamber inlet provides a passage for waste from a domestic source or the like to enter the decomposition chamber. The waste inlet is preferably positioned above the separation means.
[0030] The separating means is preferably in the form of either:
[0031] (a) a substantially non-porous separating cone, wherein an apex of said cone is located adjacent a waste discharge outlet; or
[0032] (b) two elongate substantially non porous inclined surfaces, each having curved lower outer longitudinal edges, and sharing a common upper longitudinal edge which defines a substantially horizontal top edge of the separating means, wherein one end of the separating means is located adjacent a waste discharge outlet.
[0033] The waste inlet and/or waste discharge outlet preferably has a skirt or baffle. The skirt or baffle preferably extends about the periphery of the inlet opening. The skirt or baffle preferably serves to restrict the flow of waste into the chamber and ensure relatively even distribution of the waste over separating means. The skirt or baffle may be formed from flexible material such as vertically positioned plastic strips.
[0034] Solid waste that falls off the separating means preferably is treated by the solid waste treatment means. The solid waste treatment means is preferably located below the separating means. Preferably a minimal amount of liquid is also treated with the solid waste by the solid waste treatment means. Preferably one to twenty percent of liquid waste and more preferably less than ten percent of liquid waste is treated by the solid waste treatment means. In one preferred embodiment two percent is treated by solid waste treatment means.
[0035] The solid waste treatment means preferably includes one or more support mesh screens substantially horizontal, the support mesh screen(s) being positioned for receiving solid waste, preferably below the separating means. The support mesh screens are preferably disposed one above the other and are separated by substantially equal distances. The upper screen preferably has wider apertures than the adjacent screen below. In one preferred embodiment the solid waste treatment means includes a series of support screens.
[0036] An uppermost screen may include a plurality of baffles for breaking up the solid waste and exposing greater surface area of the solid to the air to avoid decomposition. The baffles may be in the form of, for example, mushroom-shaped projections or nodules. A lowermost screen may be inclined to direct decomposed particulate solids towards a solids pump well.
[0037] In one embodiment, there are three screens with an upper screen preferably formed from 25 mm woven mesh material, while a middle screen and lower screen preferably formed from 13 mm and 5 mm woven mesh material respectively. In another embodiment there are two screens with an upper screen being 10 mm and a lower screen being 5 mm woven mesh.
[0038] Each support screen preferably has one or more sections where the gauge of the apertures are smaller so that the solid waste is retained until it is decomposed to a size that will pass through to the screen. The sections with the smaller gauge apertures are offset relative to corresponding sections in the adjacent support screens. Making the sections with the smaller gauge apertures offset relative to corresponding sections in adjacent screens prevents solid waste from moving to the lower screen without undergoing decomposition on one of the upper support screens.
[0039] The support screens preferably support a population of worms and other suitable organisms preferably introduced into the chamber during installation. Worms and other suitable organisms are introduced to consume the waste, reduce the size of the particles and maintain aeration in the decomposing waste.
[0040] The worms and other suitable organisms may be introduced as part of an inoculum chamber mounted within the decomposition chamber whereby the organisms have access to the support screens. Alternatively the worms are added directly to the trays.
[0041] The support screens and the inoculum chamber are preferably mounted within a solids decomposition compartment. The porous solids decomposition compartment has a cylindrically-shaped side wall that preferably extends about the separating cone and downwardly below the lower support screen and a base wall.
[0042] The solids pump well is substantially centrally located in the base wall of the porous solids decomposition compartment. Preferably one or more drainage holes in a wall encompassing the solids pump well provides communication between the solids decomposition compartment and the solids pump well. On the base wall of the solids decomposition compartment there is preferably a plurality of drainage cells which serve to store and passage liquid to the solids pump well.
[0043] There may also be a fine mesh drainage filter that is located on the drainage cells and directs decomposed small particles to the solids pump well. serves to collect the majority of small particulate solids. These small solids build up and fall towards the solids pump well. Directly below the screen is an inclined nonporous surface that collects any liquid draining through the inclined screen together with any small particulate solids that pass through the screen. These solids are washed by the liquid towards the solids pump well.
[0044] The solids pump well preferably houses a pump means that pumps out the small particles and liquid. The pump means may be activated on a predetermined regular basis or when liquid reach a predetermined height within the solids pump well.
[0045] The particles and liquid are preferably pumped to a storage means. The liquid pumped from the solids pump well may be further processed as described below. The storage means is preferably disposed near the top of the chamber and is accessible to allow removal of the stored solids. In one embodiment the solids and liquid is pumped to a vegetation cell or an external trench.
[0046] Decomposition of the solid waste preferably occurs under aerobic conditions.
[0047] The solids decomposition compartment is preferably passively aerated. The solids decomposition compartment is preferably aerated as a result of one or more vents in the decomposition chamber.
[0048] A major portion of the liquid waste preferably runs down the non-porous outer surface of the separating means, follows the curved surface inwardly and drips into a liquid collection means. In a preferred form, the liquid collection means is a collection chamber or collection tray located under the separating means. The separation means preferably overhangs the collection chamber thereby substantially avoiding the collection of solids waste.
[0049] A major portion of the liquid waste separated from the waste stream by the separating means is preferably treated by the liquid waste treatment means. The portion of liquid waste treated by the liquid waste treatment means is preferably ninety percent and more, preferably ninety-five percent or more.
[0050] Liquid waste is preferably collected from the separating means in a liquid collection means and then treated by the liquid waste treatment means.
[0051] The liquid waste treatment means preferably includes one or more layers of trickle bed media. Preferably the liquid waste treatment means includes a plurality of layers with alternating relatively coarse trickle bed media and relatively fine trickle bed media. The relatively coarse trickle bed media may include particularized agricultural pipe whereas relatively fine trickle bed media may include peat moss.
[0052] Each of the layers of relatively coarse trickle bed media are preferably well ventilated. The layers of relatively fine trickle bed media are preferably not well ventilated and act as anaerobic zones. The liquid waste passing through the trickle beds preferably serves as a substrate for colonized bacteria populations to reduce the BOD (Biochemical Oxygen Demand) of the liquid. Some of the nitrogen may also be removed as a result of nitrification/denitrification in the alternate fine/coarse trickle bed layers.
[0053] In a preferred embodiment, the liquid separated by the separating means is introduced about midway between the trickle bed layers.
[0054] In a preferred embodiment, the trickle bed layers form annularly about the solid waste treatment means. The wall of the solid decomposition compartment may in one or more areas be porous to allow ventilation of trickle bed layers. By having one or more porous areas, any particulate solids that accumulate within the trickle bed layers may be decomposed by worms and other suitable organisms passing through into these beds. The side wall of the solids decomposition compartment is preferably porous. Liquid passing through the trickle bed layers in a sideways direction reaches the sidewall and flows downward and does not pass through into the solids decomposition compartment (possibly by means of surface tension)
[0055] Worms and other organisms pass through the porous side wall.
[0056] There is preferably a liquid pump well where liquid that has permeated through the trickle bed is collected and stored and pumped for recirculation in the liquid waste treatment means, discharged to an external trench or vegetation cell, or used for subsoil irrigation. The liquid is pumped by suitable pump means and preferably controlled by a float switch and controller which activates the pump means at set times or when the liquid level in the pump well reaches a predetermined level.
[0057] In one embodiment, the controller may be activated and in communication with a remotely located transmitter means such as by a suitably programmed telephone or computer, for activating and monitoring the performance of the system offsite.
[0058] The liquid and solid treated waste may be further processed to produce products that can be used in other applications. The further processing of the treated waste may be formed to a standard required for the product's application.
[0059] For example, it has been found that simple pressure filtration is capable of upgrading the liquid from the first treatment apparatus to a liquid suitable for surface irrigation after a disinfection step. Also the treated waste liquid may undergo additional processing for recycling back to the household for non-potable uses or even more extensive processing to produce drinkable water. For example the treated waste liquid may be further processed by any one or combination of treatments including passage through a sand and/or carbon and/or membrane filter, an ozone treatment system to remove colour and precipitate solids, and disinfection by any suitable means.
[0060] In another embodiment, the waste treatment system may include a vegetation cell for supporting a plant, wherein, in use, treated solid waste and/or treated liquid waste is discharged to the vegetation cell. The vegetation cell supplies nutrients and/or moisture to a plant growing medium.
[0061] The present invention also provides a self-contained waste treatment system, which does not require human intervention for removal of treated waste, comprising:
[0062] a decomposition chamber having a waste chamber inlet, said decomposition chamber housing a separation means, a solid waste treatment means and a liquid waste treatment means; and
[0063] a vegetation cell for supporting a plant, wherein, in use, treated solid waste and, optionally, treated liquid waste is discharged to the vegetation cell.
[0064] There is also provided a self-contained process for treating waste, which does not require human intervention for removal of treated waste, said process comprising the steps of:
[0065] (a) separating liquid and solid waste using a separating means;
[0066] (b) treating the separated liquid waste in a liquid waste treatment means;
[0067] (c) treating the separated solid waste in a solid waste treatment means;
[0068] (d) optionally further treating the liquid waste; and
[0069] (e) discharging the treated solid waste and, optionally, the treated liquid waste to a vegetation cell.
[0070] All aspects of the waste treatment system described herein may also be included in the self-contained waste treatment system and process above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] In order that the present invention be more readily understood and put into practical effect, reference will now be made to the accompanying drawings wherein:
[0072] FIG. 1 is a vertical cross-sectional view of a first embodiment of the waste treatment apparatus according to the present invention;
[0073] FIG. 2 is an upper horizontal cross sectional view of the apparatus of FIG. 1 ;
[0074] FIG. 3 is a plan view of the support screens of the apparatus of FIG. 1 ;
[0075] FIG. 4 is a perspective view of the collection well of the apparatus of FIG. 1 ;
[0076] FIG. 5 is a perspective view of the inclined screen of the apparatus of FIG. 1 ;
[0077] FIG. 6 is an elevation view of a vegetation cell;
[0078] FIG. 7 is a plan view of the vegetation cell of FIG. 6 ;
[0079] FIG. 8 is an elevation of a subsequent treatment process involving filtration;
[0080] FIG. 9 is a vertical cross-sectional view of a second embodiment of the waste treatment apparatus according to the present invention;
[0081] FIG. 10 is an upper horizontal cross sectional view of the apparatus of FIG. 9 ; and
[0082] FIG. 11 is a plan view of the support screens of the apparatus of FIG. 9 .
[0083] FIG. 12 is a perspective view of a separating means according to the present invention.
[0084] FIG. 13 ( a ) is a cross-sectional view of a first end of the separating means of FIG. 12 .
[0085] FIG. 13 ( b ) is a cross-sectional view of a second end of the separating means of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0086] Two embodiments of the apparatus for the treatment of wastewater generated from a typical domestic house are shown in FIGS. 1 to 5 (first embodiment) and 8 to 10 (second embodiment).
[heading-0087] First Preferred Embodiment
[0088] With reference to FIGS. 1 to 5 there is shown a waste treatment apparatus 11 . The waste treatment apparatus 11 has an outer housing 12 that surrounds a substantially ring shaped trickle bed 13 , a centrally located separating cone 14 , two solids decomposition trays 15 and 16 located below the separating cone 14 and a substantially concave screen 17 .
[0089] Waste is introduced into housing 12 through waste inlet pipe 20 which is positioned by supports 21 so that the opening 22 is above the separating cone 14 .
[0090] The opening 22 has a baffle 23 that directs waste towards the apex of the cone 14 .
[0091] The cone 14 is non-porous and shaped so that waste runs downwardly from the apex along inclined surface 25 . The inclined surface 25 has an approximate 25 degree angle with respect to the horizontal axis. The cone diameter in the preferred embodiment is 560 mm while the radius of the lower curved surface is 46 mm.
[0092] From the inclined surface 25 a major portion of the liquid waste moves around the lower curved surface 26 of the cone 14 , along the base wall 27 of the cone 14 and drips into the collection well 23 . The lower curved surface 26 overhangs the collection well 23 so to avoid solid waste particulates from falling into the collection well 23 . The movement of the liquid waste around the lower curved surface 26 is possibly due to surface tension. In contrast solids waste falls off the separating cone 14 as it moves around the lower curved surface 26 . Smaller solids waste particulates may move further around the lower curved surface than larger solids waste particles. The majority of solids waste falls off into the solids decomposition tray 15 while very small solids waste particulates may move along the base wall 27 with the liquid waste and fall into the collection well 23 .
[0093] The liquid waste flows over baffle 28 and then piped from the collection well 23 along pipes 35 into distribution wells 36 and introduced into a coarse media layer in the lower part of the trickle bed 13 . Baffle 28 forms part of the support 29 for mounting the separating cone 14 . The distribution wells 36 are substantially on opposite sides of the trickle bed 13 . The trickle bed 13 consists of alternate layers of fine and coarse filter media. In one form there is six alternate layers of coarse (crumbed or chopped agriculture pipe) filter and fine (particulates of 3 to 25 mm) filter. The coarse filter layers are aerated through outlets 37 in vent 38 and pumpwell 47 . Liquid waste passes though the trickle bed media while undergoing decomposition and BOD reduction. Liquid is substantially prevented from passing from the trickle bed 13 to the central cavity 18 by barrier 39 . The barrier 39 is made of porous material allowing aeration of the trickle bed media and retaining the integrity of the trickle bed 13 . Liquid passing through the trickle bed 13 and in contact with the porous barrier 39 flows down the trickle bed-barrier surface and does not pass through to the central cavity 18 .
[0094] The trickle bed 13 is supported on a series of drain pipe sections 30 formed in a spoked wheel arrangement. The drain pipe sections 30 pass through a central pump well housing 48 .
[0095] Liquid after passing through the trickle bed 13 accumulates in a collection chamber 40 and is recirculated by pump 41 in liquid pump well 47 to the top of the trickle bed 13 . Liquid reaches pump 41 by passing through opening 49 which provides communication between the collection chamber 40 and the liquid pump well 47 . The controller 42 activates liquid pump 41 and controls the recirculation time and the interval time.
[0096] The liquid is pumped by liquid pump 41 through circulation pipes 31 to distribution pipes 32 which have a series of apertures for reintroducing liquid to the trickle bed 13 . The distribution pipes 32 substantially overlays the trickle bed 13 in a ring-like arrangement. In cases where no further treatment is required a small portion of the liquid is diverted at a T-junction 33 formed with circulation pipes 31 .
[0097] Liquid is diverted through the T-junction 33 and diversion pipe 34 to the outside of the waste treatment apparatus 11 such as to an external trench. In cases where further treatment is required the liquid can be discharged from the treatment apparatus 11 through pipe 31 and a portion recirculated to distribution pipes 32 overlaying the trickle bed 13 .
[0098] If the liquid pump 41 fails the liquid collects in the collection chamber 40 and the liquid pump well 47 . At a preset level, a high level indicator 43 activates an alarm light 44 and liquid passes through slot 45 in the central pump well housing 48 into the central pump well 46 for removal.
[0099] Solid waste and a small amount of liquid falls into the solids decomposition tray 15 . Worms and other organisms involved in the decomposition of solid waste are introduced onto trays 15 , 16 during installation and start up. The worms and other organisms consume the solid waste and reduce particle size. As particle size is reduced they fall through the mesh trays 15 and 16 . Mesh tray 15 (approximately 10 mm gauge mesh) with six segments of finer mesh spaced equidistant around the tray 15 . The finer mesh segments serve to retain the larger particles for further decomposition. Mesh tray 16 (approximately 5 mm gauge mesh) is immediately below tray 15 . Biological decomposition with worms and other organisms continues on tray 16 . Tray 16 also has finer mesh segments offset (approximately 30 degrees) to the finer mesh segments in tray 15 . Both trays 15 and 16 are substantially horizontal.
[0100] Concave or dish shaped screen 17 has an inclined mesh surface 50 to direct small particles to the centre of the screen 17 so that they can enter the central pump well 46 . Biological decomposition also occurs on screen 17 . Screen 17 has a 2 mm mesh surface 50 which allows liquid and very fine particles to pass through to an inclined base wall 51 . The liquid moves downwards and passes through the apertures 52 and into the central pump well 46 . When the liquid moves downward it collects the very fine particles which also pass into the central pump well 46 .
[0101] When material in the central pump well 46 accumulates above a set level, a float switch 53 activates central pump 54 and the material is transferred through a transfer pipe 55 out of the system to a vegetation cell 60 . If central pump 54 fails to be activated, level alarm 54 a and light alarm 44 is activated. If central pump 54 fails to be activated, material overflows through slot 45 and into the collection chamber 40 . Material is then pumped away by liquid pump 41 through the circulation pipes 31 as discussed above. In this situation the material maybe directed out of the waste treatment apparatus 11 through the diversion pipe 34 .
[0102] Where the treatment apparatus 11 is approximately 1800 mm in diameter and 1800 mm in height it may be used to treat the domestic waste for approximately 10 people (approximately 2000 litres per day).
[0103] Digestion of the liquid and solid waste proceeds largely aerobically because of aeration provided to all parts of the system through ventilation to the trickle bed 13 and solids decomposition trays 15 , 16 , and screen 17 from a vented central cavity 18 . The central cavity 18 is passively vented through vents 38 in the upper portion of the treatment apparatus 11 .
[0104] With reference to FIGS. 6 and 7 there is shown a vegetation cell 70 which is a chamber 71 slotted at the side and end walls 72 but with no base wall. The top of the chamber 71 is buried 300 mm below ground level. There is a plant tube 71 a positioned within the vegetation cell 71 in which a suitable plant 75 may be grown.
[0105] The plant tube 71 a contains suitable plant growing medium such as potting mix or gravel. The plant tube 71 a has a sidewall 71 b which has a lower porous portion 71 c located within the vegetation cell 71 . The porous portion 71 c permits nutrients and moisture to pass through into the plant tube 71 a . A discharge pipe 73 (which may correspond with discharge pipe 55 ) from the treatment system 11 enters the chamber 71 and serves to introduce treated liquid and solids. A distribution ring 74 connected from pipe 73 distributes liquid and solid around the chamber. The plant tube 71 a is centrally located within the distribution ring 74 .
[0106] In cases where further treatment is desirable one alternative system 160 is shown in FIG. 8 . Liquid discharged through pipe 31 passes through a non-return valve 161 to a filter 162 containing sand or other filtering media. The liquid is then recirculated back to the distribution pipe 32 in the water treatment apparatus 11 through pipe 163 , valve 164 and T-pipe 165 . At approximately the same time, a small quantity of liquid is discharged for further treatment and/or disinfection through valve 164 , T-pipe 165 and pipe 166 . Periodically the filter is backwashed to the vegetation cell or first treatment tank by closing valve 164 and opening valves 167 , 168 .
[heading-0107] Second Preferred Embodiment
[0108] With reference to FIGS. 9 to 11 , there is shown a waste treatment apparatus 110 which can be installed either above or below ground level. The apparatus 110 is aerated through a number of vents 135 .
[0109] The apparatus 110 consists of a first treatment chamber 111 . Liquid and solid waste enters the chamber 111 through waste pipe 112 . The outlet of the pipe 112 is positioned above a separation cone 113 . The end of the pipe 112 has a flexible geotextile skirt 114 which serves to dampen the rush of the waste stream onto the cone 113 .
[0110] The cone 113 is formed from a porous woven mesh membrane that allows at least a proportion of the liquid in the waste stream to pass through. The cone 113 allows about 95% of the liquid in the waste stream to separate from the solid waste.
[0111] The liquid from the cone 113 collects in a tray 115 and then drains through two exit pipes 116 arranged 180° apart into respective funnels 117 . The liquid is then distributed by pipe 118 into a series of layered trickle beds 130 . The liquid is distributed into the beds 130 by pipes 118 .
[0112] The majority of the solid waste in the inlet stream and a relatively small quantity of liquid is deflected by separating cone 113 outwardly before falling downwardly onto top tray 121 . The top tray 121 is comprised of alternating regions of relatively coarse mesh 122 (25 mm gaps) and relatively fine mesh 123 (e. g. shadecloth).
[0113] Worms, other living organisms, wormcast and fibre mix are introduced into the centre chamber 124 prior to commissioning of the apparatus 110 . The worms and other living organisms can move through the porous wall of the centre chamber 124 to the waste caught on the tray 121 .
[0114] Smaller material and decomposed larger material falls through the top tray 121 onto the middle tray 125 below where it again is consumed by the worms and other living organisms that have moved out of chamber 124 . The middle tray 125 also has alternating regions of coarse mesh 122 (13 mm gaps) and fine mesh 123 .
[0115] The regions of fine mesh 123 of middle tray 125 are offset such that the fine mesh 123 of the middle tray 125 is positioned below the coarse mesh regions 122 of top tray 121 . In this way, any solid material that falls straight through top tray 121 is caught by the middle tray 125 .
[0116] As the material on the middle tray 125 breaks down it falls to a third bottom tray 126 where it again can be consumed by the worms and other living organisms that have moved out of chamber 124 . Bottom tray 126 again has regions of relatively coarse mesh 122 (5 mm gaps) and fine mesh 123 (e. g. shade cloth). The fine mesh 123 of the bottom tray 126 is again offset from that of the middle tray 125 such that matter that falls through the mesh 122 of the middle tray 125 preferably lands on the fine mesh 123 of bottom tray 126 .
[0117] Once the material falls through bottom tray 126 it builds up on a bed of fine fibre 127 supported on a membrane 128 and drainage cells 129 that are positioned during start-up.
[0118] As the solids build up on bed 127 they fall into the centre well 131 . Some liquid also flows into this well 131 either with the solids or through drainage holes 132 from drainage cells 129 . Pump 133 in well 131 is activated when the liquid reaches a pre-determined height. The solids and the liquid in well 131 are then pumped to an annular distribution pipe 134 and pass through small holes into a collection tube consisting of agricultural pipe covered by filter sock. The solids are retained in the tube for removal during a service of the apparatus and the liquid passes through the sock into the top of the trickle beds 130 . Alternatively the liquid and solids can be pumped to a vegetation cell as in the first embodiment.
[0119] The trickle beds 130 are separated from the first treatment zone 120 by a wire screen and porous shade cloth membrane 136 in the upper section of the chamber 111 and by an impervious membrane 137 at the base of the chamber 111 .
[0120] Aerobic bacteria form within the trickle beds 130 and serve to reduce the BOD and nitrogen in the wastewater as it passes through the beds 130 .
[0121] The liquid leaving the trickle beds 130 passes into the collection chamber 139 .
[0122] The liquid from the collection chamber 139 flows into pump well 141 where it is pumped by pump 142 out of the chamber 139 . The liquid can be recirculated back through the trickle beds 130 , pumped to a granular filter of a further liquid treatment apparatus 160 , or used for cleaning the separation cone 113 .
[0123] The liquid is recirculated to the trickle beds 130 through annularly disposed, distribution nozzles 143 . The frequency of recirculation is set by a controller to maximise BOD reduction in the trickle beds 130 . The recirculation continues either until a low level float probe in well 141 is activated or the recirculation time set in the controller is exceeded. The liquid passes down through the beds 130 which comprises a alternate layers of fine media 144 , such as peat moss, followed by course media 145 , such as chopped up 63 mm agricultural pipe. Each layer of the course media 145 is ventilated through holes in vent pipe 135 .
[0124] Liquid passing through the separation cone 113 and entering the trickle beds 130 through distribution pipe 118 passes through at least one layer of fine trickle media 144 and one layer of course media 145 before it enters collection chamber 139 .
[0125] At preset intervals, for example 1 minute per day, the controller can open a valve and a preset quantity of treated water can be pumped to the cone 113 through pipe 146 to clean any accumulated solids off the membrane 113 . The liquid is directed tangentially across the membrane 113 through a slit around the circumference of nozzle device 147 and also up through the screen through nozzles 148 . The washing time is set prior to pump out to ensure there is always water available for cleaning.
[0126] The apparatus can include a high level probe, connected to a visual alarm with buzzer positioned within the house, to signal a malfunction of the system and to ensure manual override of the pump 142 when required.
[0127] At preset times or when the high level probe is activated, the liquid in the collection chamber 139 can be pumped through pipe 149 to a trench or further liquid treatment apparatus.
[heading-0128] Separator
[0129] FIG. 1 shows one preferred form of the separator (“separating means”) of the present invention. Referring to FIG. 1 , there is shown a separating means substantially in the shape of a cone 14 , having an inclined surface 25 and a curved lower surface 26
[0130] FIGS. 12 and 13 show another preferred form of the separating means of the present invention. Referring to FIG. 12 , there is shown a separating means having two substantially non porous inclined surfaces 201 and 202 , each surface having corresponding curved lower outer longitudinal edges 203 and 204 respectively. The surfaces 201 and 202 are generally elongate and share a common longitudinal upper edge, which defines a substantially horizontal top edge 205 of the separating means. Each of the curved lower outer edges 203 and 204 has a corresponding longitudinal flange 206 and 207 respectively. The longitudinal flanges are positioned for directing liquid waste into a liquid collection means. The liquid collection means is generally in the form of a tray 208 positioned beneath the separating means. The side walls 209 and 210 of the tray 208 are positioned outside the longitudinal flanges 206 and 207 so that separated liquid drips into the tray 208 .
[0131] The separating means has a first end 211 and a second end 212 . In use, the first end is located adjacent to a waste discharge outlet (not shown), and the second end is located distal to the waste discharge outlet. Hence, in use, waste is delivered longitudinally along the top edge 205 of the separating means.
[0132] Referring to FIGS. 13 ( a ) and ( b ), the separating means is tapered towards the second end 212 of the separating means, such that the second end 212 is smaller in cross-section that than the first end 211 .
[heading-0133] Advantages
[0134] The advantages of the present invention include the decomposition of domestic waste onsite through the passive separation of liquid and solid waste and identification and use of suitable treatments for each substrate. With the preferred embodiment of the invention there is no requirement to remove bi-products from the treatment site. The water quality produced from the treatment system is relatively high compared with other primary treatment systems. Therefore the water discharged from the treatment system requires fewer steps to produce relatively high quality water.
[0135] Furthermore the separation and respective treatments for the liquid and solid wastes is arranged in a compact manner that minimizes capital and installation cost and allows scaling up of the treatment system and or the use of multiple treatment system modules.
[0136] There is also the provision of reusable water and treated solids waste as nutrient plant media.
[0137] As the waste is largely aerobically digested, the treatment system has the further advantage that little if any unpleasant odours are produced during decomposition.
[heading-0138] Variations
[0139] It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.
[0140] Throughout the description and claims this specification the word “comprise” and variations of that word such as “comprises” and“comprising”, are not intended to exclude other additives, components, integers or steps.
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The present invention relates to a treatment system for treating primary waste onsite. The treatment system includes a separation cone which separates the solid waste from the liquid waste and the different wastes are subsequently treated separately. The solid wastes are subject to aerobic decomposition by worms and other suitable organisms while liquid wastes are filtered through alternate layers of coarse and fine filter media. The resulting treated liquid can be recirculated or pumped out of the system for other purposes or further treatment. The treatment system is designed as a compact modular system and maybe used for the treatment of domestic human waste.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of provisional application Ser. No. 60/970,446, filed Sep. 6, 2007, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates generally to interaction with an animated graphics presentation engine on a remote, a resource-limited device.
BACKGROUND OF THE INVENTION
[0003] Computer applications are typically written using standard computational programming language, such as C and C++. However, in order to more easily create sophisticated user interfaces and other applications providing rich media content and experiences, developers are turning to the use of graphics-oriented programming languages and platforms for developing rich media applications. These platforms reduce the burden of programming media-intensive interfaces and rich media applications by taking advantage of development tools oriented toward graphics and rich media, and presentation engines that perform much of the graphics processing.
[0004] In an application written using animated graphics, a series of static displays are sequentially rendered to create the illusion of animation. Each of these displays will be referred to generally as a “frame.” Examples of such development environments include the Adobe® Flash® development tools, which generate SWF files, and programs written using SVG, which is a language for describing two-dimensional graphics. These applications or files describe graphical elements, text and other elements that are to be rendered, typically using standard vector graphic techniques. They also specify, for each frame, the placement of elements on a “canvas” within the frame. Bit map images, video and audio can also be referenced, placed and displayed or played according to a time line. A “presentation engine” or “player” reads the descriptions of the frames and the graphical elements and renders the frames according to the specified time line, and executes scripts associated with each frame and interaction with a user or the device on which the file is being executed.
[0005] For example, the Flash® development environment, which is widely used for creating web-based applications, generates a SWF file that encodes descriptions of the graphical elements, a description of each frame in terms of placement of graphical elements on the canvas for the frame, and any scripts that are to be executed in connection with rendering of the frame or the user's interaction with it. The frames are rendered at a specified frame rate. Similarly, SVG specifies a “document” containing one or more “pages” for display. Each page contains an ordered grouping of graphical elements. Only one grouping is displayed at a time. Animation is created by using Synchronized Multimedia Integration Language (SMIL) to specify timing for rendering each page. Scripts are used to provide interaction with the elements and navigation between the pages.
[0006] A rich media application written using an animated graphics format or language—an “animated graphics application” —does not need to be concerned with the details of rendering the graphics and coordinating video and audio, simplifying development and reducing the size of the applications. Scripts can be kept relatively simple by taking advantage of application programming interfaces (APIs) that are implemented by the presentation engines. The APIs typically provide a suite of standard functions, as well as functions for enabling interactivity with the animated graphics and for controlling or interacting with the devices. Developers of applications are thus able to concentrate on the details of the applications, while developers of the presentation engine focus on enhancing playback performance of the presentation engine for particular devices and extending its functionality.
[0007] In addition to shortened development and deployment cycles, a further benefit of using animated graphics languages and authoring tools to generate rich media applications is that it allows dividing the task of writing the applications between graphics designers, who use authoring tools to create the graphical portions of the programs, and programmers who write scripts to add functionality and interactively.
[0008] Animated graphics applications are particularly well-suited for developing rich media applications running on “embedded systems.” An embedded system is, generally speaking, a special purpose computer system designed to perform certain dedicated functions, which has been embedded into a device. Examples include mobile telephones and other hand-held or mobile devices, and set top boxes for cable and satellite television. Microprocessors or other logic circuits embedded in these devices or equipment are programmed to perform specific functions for the device. Economic considerations dictate that embedded systems have limited processing capability and memory and, at least in the case of mobile devices, smaller screens. Typically, these computing resources are just enough to perform the necessary functions. Resource-limited devices, such as these, are generally not intended to be independently programmable by end users. They sometimes do not permit the user to load additional applications.
[0009] Examples of applications that can be written for set top boxes using a graphics language or platform include those that enable users to interact with advanced network services, such as video on demand (VOD) services, digital video recorder (DVR) services, and electronic program guides, as well as games and many other types of applications. Similarly, on a mobile network, a network operator may want to deploy rich media applications, which can be downloaded as required to the mobile device, for allowing easy interaction with services offered by a mobile network, such as, for example, mobile television, music, podcasting, andservices that enable easy access to remote devices and internet-based content.
SUMMARY OF INVENTION IN ITS PREFERRED EMBODIMENT
[0010] The invention pertains generally to tools and methods for analyzing the performance of animated graphics and applications written at least in part using animated graphics. The invention is used to particular advantage in evaluating performance of applications with sophisticated user interfaces, where delay in the performance of the interface is undesirable or unacceptable, and of animated graphics and rich media applications written for execution on resource-limited devices.
[0011] Profiling tools used in connection with programs written using traditional languages typically collect execution statistics and information that relate to method and function calls made by the program. This can be done through various techniques, including “instrumentation” of the application, sampling at predetermined intervals, and event notification (such as by a virtual machine running the program). However, these tools and methods are of limited usefulness for analyzing the performance of rich media applications, particularly those written using animated graphics. Collecting information on function calls and methods of the presentation engine provide little useful feedback to an author of an animated graphics application.
[0012] A presentation engine employing the teachings of the invention in its preferred embodiment collects information concerning the rendering of the frames of an animated graphics application, such the time taken for rendering the frame and the amount of memory used. This information quantifies the amount of one or more computing resources being utilized on a per-frame basis, enabling identification by the authors of the animated graphics application, particularly by the designers of the animated graphics, of frames that are problematic, especially on resource-limited devices. The generation of information does not depend on the animated graphics application being instrumented to generate the metrics, and therefore may be easily utilized by graphics designers and others who may not have extensive programming capabilities or experience and are often involved with developing animated graphics applications. Furthermore, the method is adaptable to any resource-limited device, to which the presentation engine is ported or adapted to run. When executing on a resource-limited device, the information is preferably sent to a workstation for analysis. An analysis tool, which may be a stand-alone program or part of an authoring tool or other program, preferably displays the collected metrics graphically in relation to the frame.
[0013] According to another aspect of the invention in its preferred embodiment, the presentation engine is preferably also capable of collecting performance metrics for scripts that are executed in connection with frame. It may also collect performance metrics for scripts that are executed in response to an input event and system events.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic diagram representing the basic relationship between a presentation engine, an animated graphics application, and a development tool.
[0015] FIG. 2 is flow diagram representing the basic steps of a computer implemented process of a development tool for debugging and profiling animated graphics applications.
[0016] FIG. 3 is a flow diagram of one example of a process of using a development tool in connection with the process of FIG. 2 .
[0017] FIG. 4 is a diagram schematically representing a user interface of a software implemented tool for analyzing the performance of animated graphics applications.
[0018] FIG. 5 is a schematic diagram representing certain computer processes and files on a workstation and a remote, resource-limited device.
[0019] FIG. 6 is a schematic diagram representing hardware components of the workstation and the remote, resource-limited device of FIG. 1 .
[0020] FIG. 7 is a flow diagram representing a basic process of communicating between a server executing on a workstation and a presentation engine executing on a remote device.
DETAILED DESCRIPTION
[0021] In the following description, like numbers refer to like elements.
[0022] Referring to FIG. 1 , animated graphics application 102 is a file that describes, at least in part, its user interface using animated graphics. Current examples of these languages and platforms include the SVG graphics language and Adobe® Flash®. However, animated graphics languages and platforms are not limited to these examples, and include any type of language or platform in which user interfaces are programmed by specifying placement and movement of graphical objects. The application likely also includes scripts that enable, for example, user interactivity with the application, control over animation (such as starting and stopping it, jumping to other frames and other similar functions), retrieval and processing of data, and many other functions.
[0023] Presentation engine 104 represents a collection of software-implemented processes running on a microprocessor, which read the descriptions of the graphics animation in the application file and render the graphics. These processes can be implemented with code that is part of a computer program or bundle of computer programs dedicated to this purpose, or as part of another program or collection of programs that provide additional functionality. No particular implementation is implied. Furthermore, the presentation engine preferably also includes, or is set up to work with, a script engine for processing scripts in the application and an application programming interface (“API”) that can be accessed by the scripts. The API preferably also implements functions and methods that are useful for executing rich media applications and that provide access to features or capabilities specific to the device on which the presentation engine is running. The presentation engine may also be distributed with decoders for different types of media resources that may utilized by the application, such as decoders for video, bit mapped images and sound. However, the presentation engine can be configured to make use of other decoding libraries.
[0024] Current examples of implementations of the presentation engine 104 include, but are not limited to, the MachBlue™ presentation engine distributed by Bluestreak Networks, Inc. of Montreal, Canada and the Flash® and Flash Lite® players of Adobe Systems, Inc. The MachBlue™ presentation engine is designed to run as middleware on embedded systems with limited processing power and memory, such as set top boxes for cable and satellite television and similar devices. The MachBlue presentation engine interprets and renders files encoded according to the SWF file format (though it does not support rendering of all features of Flash® authoring environment) as well as certain extensions to the SWF file format adapted for specific devices.
[0025] The presentation engine preferably includes processes that measure, or that collect information to enable measurement by other processes not included in those of the presentation engine, certain metrics concerning the presentation engine's rendering of the animated graphics described by the application and associated scripts. The collected information is then reported to another set of processes for analysis by the developer. This other set of processes will be referenced as development tool 106 for analysis. The development tool can be comprised of a computer program dedicated to collection, storage and analysis of the information, or as a plug-in to another type of development tool. The processes can also be implemented directly by other types of development tools, including authoring tools such as Adobe® Flash®. No particular implementation should be implied or foreclosed by references to the development tool.
[0026] Illustrated in FIG. 2 are the basic steps of a process of collecting performance metrics for an animated graphics application based on the occurrence of a frame rendering event, an input event and a system event. The process assumes that the presentation engine has been configured to generate at least one metric. Collection of all of the metrics it might otherwise be capable of generating need not be enabled. Metrics could include, but are not limited to, one or more of the following: total memory allocated to executing application; time to execute frame, time to render graphics for entire frame or just part of frame; script execution time for frame; total memory used by application; count of script objects; count of graphics objects drawn during frame; count of movie clips; count of buttons; count of text fields; and count of shapes. The metrics include or are generated using, for the most part, information that a presentation typically keeps track of, or that can be easily calculated from what a presentation engine keeps track of, when executing an animated graphics application. These metrics impact performance of an animated graphics application but are not easy to perceive from the display of the application. For example, object counts allow a designer to find graphical objects that are not visible (perhaps because they are fully occluded by other elements). These objects are “dead weight” and can be eliminated.
[0027] The presentation engine begins executing the animated graphics file at step 200 . If it is time to render a frame, as indicated by step 202 , the presentation engine renders the frame, executes any scripts associated with the frame, and measures specified metrics at step 204 . The term measure is intended to refer to any gathering or generation of information relating to a specified metric, and need not include all steps necessary for calculating a final result unless specifically stated otherwise. The term “metrics” in this description is intended to refer to not only the final value for the metric, but also any information collected by the presentation engine for calculation of the metric. The metrics are then reported at step 206 . If, as indicated by step 208 , an input event occurs, the presentation engine also measures any specified metrics applicable to the script or scripts and any graphic renderings associated with the event at step 210 , and reports them at step 212 . An input event may include a user pressing a key or selecting a button or other graphic. When a system event occurs, as indicated by step 214 , metrics associated with rendering graphics and executing the scripts that are occurring in response to the event are measured at step 216 and reported at step 218 . System events include, for example, backlight on/off, changes in network state, power input on/off, and loading of resource files. If the application has not ended at step 220 , the process loops back to step 202 . The loop formed by decision steps 202 , 208 , 214 and 220 is intended to represent an event-driven process. Reporting of a metric may include writing the information to a file, or transmitting in real time or on a delayed basis the metric in a message sent to another program, such as development tool 106 . Any traces embedded in the application and encountered during rendering of the frame or execution of scripts are also reported.
[0028] FIG. 3 illustrates a representative process of using a development tool 106 ( FIG. 1 ) to collect metrics. The development tool is, as indicated at step 302 , used to define the metrics to be measured and collected. If the presentation engine that will be executing the animated graphics application is running on a remote device, as indicated by step 304 , the development tool connects with the remote device at step 306 and transfers the application to the remote device at step 308 for execution. The development tool also specifies metrics to be collected at step 310 . Steps 308 and 310 can be performed in reverse order. The development tools receives any trace messages embedded in the application and the measured metrics at steps 312 and 314 . The order in which traces and metrics are received is immaterial. As previously mentioned, traces and/or performance metrics information is preferably sent in messages on a per-event basis (either in real time or delayed). When the application is executing on a resource-limited device, doing so avoids having to store the information on the remote device, which may effect performance. However, the metrics can also be sent in batches during execution, or in one or more files at the end of the execution of the application. The details of connecting to the remote device, and communicating with the remote presentation engine are described in connection with FIGS. 5-7 .
[0029] Referring now also to FIG. 4 in addition to FIG. 3 , once the metrics are made available to the development tool, the metrics are displayed on one or more graphs 402 in a window 404 in the application window 406 of the development tool on a computer display 400 , as indicated by step 316 . Each graph preferably displays the value of the metric on a frame or time basis, with the x-axis indicating the frame or time and the y-axis indicating the value of the metric for the particular frame. However, multiple metrics can be displayed on the same graph. As indicated by step 318 , cursor 408 is used to select a frame. Numerical values for the metrics of a frame selected by the cursor are displayed in fields (not shown) adjacent to the graphs. Traces are displayed in window 410 . File names for the animated graphics applications are shown in window 412 . Profiles for different applications can be stored and displayed.
[0030] Referring to FIGS. 5 and 6 , collecting performance metrics is particularly useful for development of animated graphics applications intended to run on resource-limited devices. FIG. 5 schematically represents software-implemented processes and files on a workstation 502 and resource-limited remote device 504 . FIG. 6 schematically represents the hardware for storing and executing software program instructions for performing the processes. Animated graphics application 506 is stored on general purpose computer workstation 502 . The workstation includes a processor 508 , memory 510 for temporary storage of executing programs and data, and one or more disks 512 for storage of program and data files. The workstation is coupled to a remote device 504 . Examples of the remote device include, but are not limited to, a set top box and a mobile, hand-held device with wireless communication capabilities, for example a cellular telephone or device with “Wi Fi” capabilities. The remote device includes a resource-limited embedded system 514 comprised of a central processing unit 516 for executing program instructions and files stored in memory 518 . The device will also have additional elements relating to the particular purpose of the device. For example, if the device is a satellite or cable set top box, it would also include a tuner and interfaces for video and audio. In the illustrated example, the device includes a display 520 , such as would be typically found on a mobile telephone. Memories 510 and 518 are intended to represent memory generally and are not intended to represent any particular memory structure. For example, memory in an embedded system will depend on the purpose of the system, but it typically will include some type of memory for long term storage (typically non-volatile) and working memory for use by the processor in storing program code and data.
[0031] The workstation 502 and remote device 504 are coupled through a physical communications channel 522 . This communications channel is comprised of one or more links. Each link could be comprised of, for example, a wired or wireless connection. Examples of wired connections include serial, USB, and Ethernet connections. Examples of wireless connections include Bluetooth, wireless local or metropolitan area network connections (IEEE 802.11 or 802.16, for example), and cellular telephone and data networks. A presentation engine 524 for executing or playing animated graphics files on a resource-constrained remote device is loaded on remote device 504 . Communication server processes 526 executing on workstation 12 establish an application-level communication session 528 with presentation engine 524 over the physical communications channel 30 . The server processes are further comprised of processes for enabling exchanging information with the presentation engine, including requests that control operation of presentation engine, such as by configuring its execution, and exchanging of files. The server processes pass information to and from other applications that are running of the workstation, which want to communicate with the presentation engine. For example, authoring applications or other development tools such as debugging tools can utilize the communications facility. These applications could be implemented to include the sever processes, in whole or in part, or by utilizing plug-ins that provide these services. Alternately, these processes can be implemented as a independent application. The presentation engine either includes, or is configured to utilize, software for establishing the communication session and exchange communications with the server. The communications server processes for establishing and using the communication session is preferably implemented so that it is independent of the underlying physical connection between a workstation and the remote device. Resource limited devices come in many different varieties and have different capabilities for connecting to computers and networks. For example, some set top boxes support Ethernet connections and many mobile telephones do not. Mobile telephones may, on the other hand, support Bluetooth wireless connections. The software program implementing the server processes, such as for example an authoring tool or debugging tool, preferably includes mechanisms or processes for configuring different types of communications links between a workstation and the resource limited device, over which the communications with the presentation engine may take place. A representative example of a process flow 100 utilizing the communication between the presentation engine 524 and the server 526 is illustrated by the flow chart of FIG. 7 . Referring also to FIG. 7 , in addition to FIGS. 5 and 2 , the representative process 700 starts with selection of a communications method at step 702 . The server processes 526 preferably assist with configuring or setting up the physical connection with the remote device, depending on the type of device. For example, if it is a TCP/IP connection using Ethernet interfaces at the workstation and the remote device, the application implementing the server processes can be used to enter and store IP addresses for the connection. If the remote device is a cellular telephone, for example, the connection may use a Bluetooth wireless connection. The server processes could store profiles for different remote devices. Another example that can be used for Windows CE based devices is ActiveSync USB connection. Once the connection method is chosen and any configuration information not previously stored is entered, the server software initiates setting up the physical connection to the remote device at step 704 over the physical communications channel 522 . The connection depends on the software and hardware installed on workstation and remote device, to which the server software has access. Alternately, the connection may be set up manually.
[0032] At step 706 , the server software sends, over the established communication link, a request for connection to the presentation engine 524 on the remote device. The remote presentation engine 524 confirms the request by sending back certain information that identifies the device and details of the presentation engine at step 708 . This establishes a communication session with the presentation server. The remaining steps in the flow chart are illustrative only, and can be performed out of order, depending on the purpose to which the communication facility is put.
[0033] For example, the workstation at step 710 transmits a request to the presentation engine to configure itself for collection of performance metric information. The request preferably includes a list of metrics to collect. The presentation engine would then turn on metric measurement services prior to executing a rich media application. The presentation engine configures itself at step 712 and confirms the request to the server.
[0034] The workstation sends at step 714 a rich media application file to the device for execution, and at step 716 the remote device 504 receives the file. The presentation engine 524 acknowledges that the file has been successfully transferred by sending a message to the server 526 at step 718 .
[0035] The presentation engine then, as indicated by step 720 , launches execution of the rich media application. In this example, the application is written as a frame-based animated graphics movie comprised of a sequences of frames. The next frame, or the first frame if there was no previous frame, is executed by the presentation engine at step 722 .
[0036] When executing the application, the presentation engine may determine that it needs a resource referenced in the file, for example, a bitmap image such as a JPEG file or a XML file containing data, that is not stored on the remote device but rather on the remote host. The application might only specify the name of a file, and not a URL identifying the location of the file on the host or an otherwise fully qualified path to a directory on a host where the file can be found. The presentation engine is preferably enabled to send to the workstation, at step 726 , a request for a resource file 530 on the workstation that it does not have and that is required for rendering of the frame or executing a script associated with the frame. When the request is received by the workstation sever, the server assumes at step 728 that the file is located in the same directory as the rich media application 506 and transfers this file to the remote device at step 730 if it is found. If the file is not found, an error message is sent. This capability allows local resource references to be maintained in the application during development without having to download all resources to the device in connection with testing or include in the application a URL to the file on the workstation host.
[0037] At step 732 , if the presentation engine has been configured to generate metrics and/or send traces, it will send to the server on the workstation at step 734 the information on the metrics or traces upon the occurrence of frame, input and/or system event, as described in connection with FIG. 2 . Steps 722 to 734 are repeated until the application ends or is stopped, as indicted by decision step 736 .
[0038] The following is an illustrative example of a transfer protocol for implementing a preferred embodiment of communications facility for purposes of assisting with debugging and profiling of an animated graphics application being executed by a presentation engine on a remote device, and is not intended to limit the general concepts expressed above.
[0039] Data sent between a workstation and a remote device is packaged in a packet. A packet corresponds to either a message (no results are returned) or a request (a result is returned). This is controlled by a flag in all packets that indicates if a result must be returned by the receiver. A packet contains two parts: a packet header and packet data or payload. The packet header includes information on the size of the data part of the packet, a validation field and a CRC field for checking data integrity. The payload depends on the type of packet. The packet data comprises what will be termed generically below as a “request,” even though the request may actually constitute a message if no results is expected.
[0040] A request header includes one or more of the following types of information: a identifier of the type of packet, for example a trace, a file transfer, or a device information request; the size of the request; a unique request unique identifier; an application identifier that identifies a running animated graphics application file; and flags that affect the handling of the request. For example, a flag can be set to indicate that a result must be returned by the request receiver to indicate the request completion result.
[0041] Following are examples of request types for implementing this example.
[0042] An “Establish Connection” request is sent by a newly connected client to notify the server on the workstation that it is now waiting for requests. The servers send the request. The remote client responds by sending a “Device Info” request.
[0043] A “Device Info” request is sent by the client on the remote device to give information on the presentation engine and device to the newly connected client. This request is sent immediately after an Establish Connection request is received. The request preferably includes, for example, the protocol version, which indicates the device supported version of communication protocol, the device platform type, which identifies the hardware/software platform on which the presentation engine is running, and the version of the presentation engine.
[0044] A “Result” request sends the result of a received request. It preferably contains a unique identifier of the received request and the requested result.
[0045] A “File Transfer” request is used to send a file to the remote client. It preferably includes the name of the file, its size, and the actual file content, and a flag to indicate whether the file must be executed or launched by the presentation engine.
[0046] Additional requests can be structured to configure the presentation engine and to request and receive additional information from the presentation engine, which in this example is information about the execution of the animated graphics application by the presentation engine.
[0047] A “Trace” request is used by the presentation engine client to send a SWF trace. It includes an indication of the type of encoding used for the data string, for example ANSI, UCS2, UCS4, etc., the size of the data string, and the actual data string containing the trace information.
[0048] A “Frame Info” request is used to transmit metrics about the execution of a frame of the animated graphics application. The metrics is packaged as a list of value-pairs. Each value-pair includes an identifier of the metric, for example, the time it took to render the frame, the amount of memory used, the time it took to execute scripts associated with the frame, etc., and a data value.
[0049] To configure the remote presentation engine, the server on the workstation sends a Configuration request. The Configuration request specifies in its data part a list of metrics to calculate and return after execution of each frame is completed. This request is preferably sent immediately after the connection is established with a remote device.
[0050] The foregoing description is of exemplary and preferred embodiments of methods and tools for use in analyzing performance of animated graphics. The invention is not limited to the described examples or embodiments. Alterations and modifications to the disclosed embodiments may be made without departing from the invention. The meaning of the terms used in this specification are, unless expressly stated otherwise, intended to have ordinary and customary meaning and are not intended to be limited to the details of the illustrated structures or the disclosed embodiments. None of the foregoing description is to be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope. The scope of patented subject matter is defined only by the issued claims. None of these claims are intended to invoke paragraph six of 35 USC §112 unless the exact words “means for” or “steps for” are followed by a participle.
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A presentation engine collects information concerning the rendering of the frames of an animated graphics application, such the time taken for rendering the frame and the amount of memory used. This information quantifies the amount of certain computing resources being utilized on a per-frame basis, enabling identification by the authors of the animated graphics application, particularly by the designers of the animated graphics, of frames that are problematic, especially on resource-limited devices. The generation of information does not depend on the animated graphics application being instrumented to generate the metrics. The method is adaptable to any resource-limited device, to which the presentation engine is ported or adapted to run. When executing on a resource-limited device, the information is sent to a workstation for analysis. An analysis tool, which may be a stand-alone program or part of an authoring tool or other program, displays the collected metrics graphically in relation to the frame.
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This application is the U.S. national phase application of PCT International Application No. PCT/EP2007/050167, filed Jan. 9, 2007, which claims priority to German Patent Application No. DE102006001434.0, filed Jan. 10, 2006, and German Patent Application No. DE102007001458.0, filed Jan. 3, 2007, the contents of such applications being incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electronic controller and to the use of the electronic controller in a motor vehicle brake system.
2. Description of the Related Art
In high-quality electronic ABS and ESP brake control systems, at least some of the valve coils are no longer switched but rather analogized actuation is effected using pulse width modulated current control (PWM), which permits almost analog actuation of the hydraulic valves. For this, a plurality of valve actuation circuits are provided which, by way of example, may be designed using MOS transistors connected in phase opposition. To allow an inexpensive and space-saving solution, such a valve actuation circuit is usually implemented as an integrated circuit, especially since a complex ESP system requires up to eight such valve actuation circuits to be present in addition to numerous additional circuit parts. A pure analog amplifier for actuating a valve coil is not feasible for reasons of excessive power loss.
The procedure when measuring the actual current using a single A/D converter within a PWM controller, for actuating the aforementioned valve coils is already revealed by WO02/058967 A2 (P 10057) and WO03/039904 A2 (P 10253). On the basis of the circuit examples described therein, a particular number of current measuring channels is allocated to the A/D converter in line with the time slice principle on the basis of complex priority logic, so that the conversion capacity of said A/D converter can be used in as optimum a fashion as possible. This priority logic is relatively complex and therefore expensive.
The demands on the above electronic control units are increasing to an ever greater extent, since additional functions are also undertaken by the brake control unit or the brake systems need to have improved control quality. A few more recent control functions, including motor vehicle longitudinal control (ACC), which keeps the distance from a vehicle in front constant, require not only the mere capability of setting an analog current but also particularly precise current control, since slightest deviations from the desired current value produce palpable differences in the set braking pressure, which means that precise ACC control with an appropriate level of comfort is no longer possible. In the case of prolonged ACC control, it is also possible for just slight differences between the set pressure in the front and rear axles to result in failure of the brake function on one axle. In particular, relatively small currents in the range from approximately 100 to 400 mA need to have a high level of precision, since these currents are needed for setting small pressure differences, as are typical for longitudinal control.
In the case of valve actuation circuits which are designed in line with the aforementioned patent applications WO02/058967 A2 (P 10057) and WO03/039904 A2 (P 10253), it is therefore necessary to improve the accuracy of the PWM current control still further. In the case of PWM control based on the cited prior art, a general consideration in the usual application of brake control is that an inductive load (e.g. valve coil) is actuated. The inductive load has a determined inductance L and a nonreactive resistance R. The inductance L can be used to define a time constant for the load L/R. On the basis of this time constant and the actuating frequency of the pulse width modulation, a typical profile is obtained for the load current I L for the inductive load over time t, as shown in FIG. 1 . The use of an A/D converter, which is used on a number of occasions for measuring current in different valve actuation circuits, does not allow the current to be determined at a plurality of points in the current profile in FIG. 1 . The current is therefore measured at particular times (discrete-time measurements), as described in the documents cited above. Depending on the measurement time, the current value determined in this manner deviates considerably from the current's average which actually needs to be determined for the PWM control. This deviation from the average is subsequently also referred to as a form error. If, as FIG. 2 shows, the current value is regularly measured in the middle of the switched-on phase at the time t ON /2, for example, then the form error shown in FIG. 2 arises as the difference between the measured value and the average.
However, the form error is influenced not only by the measurement time for the discrete current measurement but also by other operating parameters for the PWM control, such as the voltage across the load and the temperature-dependent nonreactive resistance of the load at present. Integrated analog circuits, in particular, achieve a high level of absolute accuracy only with a very high level of outlay. Although inherently known differential circuit techniques and inherently known calibration techniques, for example, allow a certain degree of independence from technological fluctuations and temperature effects, these methods are subject to limits on account of the high level of outlay. Calibrating the circuit over temperature would require very long periods of time following production and therefore holds little advantage for production in large quantities.
The current measuring principle shown in FIG. 2 requires a minimum value for the PWM signal's switched-on time so that in each period a current value can be recorded under all constraints. The result of this minimum value is that on the basis of the nonreactive resistance of the coil, the high-side voltage on the inductance and the set PWM frequency a minimum current is obtained below which no further control is possible. In the typical application of ACC control for motor vehicles, it is thus possible to regulate only currents to a minimum of 200 mA for example. However, ACC-optimized current/braking pressure characteristics for a valve coil usually require smaller currents down to approximately 100 mA.
An object of the present invention is thus to propose an electronic controller and a method for measuring current within an electronic controller, with PWM current control, which allow more accurate and safer current setting to be performed, the electronic controller needing to be relatively inexpensive, in particular.
SUMMARY OF THE INVENTION
According to aspects of the invention, the invention achieves the object by means of an electronic controller.
An idea of proposing an electronic controller for motor vehicle control systems having at least one electronic current measuring circuit which has at least one sigma-delta modulator which measures the load current flowing through an essentially inductive load by converting an analog measurement signal for the load current into a digital measurement signal for the load current is described herein.
The use of a sigma-delta modulator firstly has the advantage that a load current can be measured by oversampling an analog measurement signal for the load current, as a result of which a plurality of current values are recorded per PWM period and hence form errors can be reduced or prevented. Secondly, sigma-delta modulators are relatively inexpensive because their resolution is not dependent on the order but rather particularly on the clock rate at which they are operated, and hence it is also possible to use low-order modulators. It is thus preferable to use at least one 1-bit sigma-delta modulator for measuring current, which requires particularly few semiconductor elements, it is therefore reasonable and can nevertheless achieve high resolution by means of the clock rate. On account of the fact that such an analog/digital converter is relatively inexpensive, it is expediently possible to use at least one in each current measuring circuit, in particular one per PWM path, which means that complex and hence relatively expensive priority logic for actuating a single analog/digital converter using all the current measuring circuits which the controller contains becomes superfluous. It is also not necessary to use the relatively expensive precision resistor (shunt), since the currents is measured preferably directly, that is to say without converting the current into an appropriate voltage, by the sigma-delta modulator.
On account of the fact that the literature uses not only the terms “sigma-delta modulator” but also the term “delta-sigma modulator” for essentially identical analog/digital converters and there is no discernible standard opinion on the correct nomenclature, the term “sigma-delta modulator” is understood to mean both terms and possible technical embodiments which are attributed or can be attributed to one or both terms.
An output signal and signal transmission are also understood to mean a data signal and output data and data transmission.
A measurement signal for the load current is understood to mean a signal which is dependent on the load current and is preferably produced by scaling the load current, such as using a sense FET, and/or which is, in particular, a voltage signal which can be tapped off across a shunt through which the load current flows. Particularly preferably, this term covers signals which depict the time profile of a measured variable for the load current or are dependent on the load current in respect of at least one variable. Alternatively, the aforementioned term also covers the load current signal per se or preferably another signal which is dependent on the load current and which is provided for measuring the load current.
A valve actuation circuit is preferably understood to mean a circuit which controls at least the current through a valve, preferably a hydraulic valve, which is an essentially inductive electrical load. In this case, the valve actuation circuit uses pulse width modulation, in particular, and has at least one switch-on path with a power driver and a recirculation path with a power driver. Particularly preferably, a valve actuation circuit is understood to mean a PWM output stage.
A duty cycle is understood to mean the ratio of switched-on phase to PWM period length.
The at least one electronic current measuring circuit is preferably integrated in the at least one valve actuation circuit or is included in it.
The at least one sigma-delta modulator in the electronic current measuring circuit of the electronic controller expediently performs current measurement for the load current by oversampling the analog measurement signal for the load current, wherein the clock rate of the sigma-delta modulator is significantly higher than the frequency of the pulse width modulation. This measure largely prevents or reduces form errors.
The electronic current measuring circuit in the electronic controller preferably has at least one sense FET which provides the analog measurement signal for the load current directly or indirectly. In this case, the gate connection of the at least one sense FET is connected particularly to the gate connection of at least one power driver in the switch-on path or in the recirculation path. In addition, the drain connections and/or the source connections of the respective sense FET and of the respective power driver are connected or coupled to one another directly or indirectly. This form of the electronic current measuring circuit allows indirect current measurement, with the current which is actually to be measured turning out to be a defined factor smaller, which allows the measuring components to be designed not necessarily for power applications, or this is required only to an appropriately lower degree.
It is expedient for the at least one sigma-delta modulator to comprise, particularly for the given situation, a control loop which has an integrator element, particularly an integrator, particularly preferably a capacitor or another component or an electronic circuit with a corresponding electrical response, a comparator and a, in particular controllable, switchable current source. This switchable current source is particularly preferably designed such that it can drive various discrete current values and can be switched between these various current values. Most particularly preferably, this switchable current source comprises a parallel circuit comprising current sources whose currents can be added in a defined manner, and this process is preferably switchable, in particular.
The output of the at least one sigma-delta modulator is preferably connected to at least one averaging device. In particular, this averaging device is a counter element or alternatively an exponentially weighted moving average filter which behaves like a first-order digital low-pass filter. Particularly preferably, the counter element is a circuit which is designed or actuated such that it sums digital data. Such a counter or such a counter element implicitly performs averaging, since all data from a sigma-delta modulator are summed by it and hence taken into account per clock cycle.
The at least one electronic current measuring circuit in the electronic controller expediently has a switch-on path and a recirculation path, each of these paths having at least one sigma-delta modulator. Current measurement during the recirculation phase too allows current control to be performed with sufficient precision even for relatively small currents or relatively low duty cycles.
It is preferred for both the switch-on path and the recirculation path each to have at least one sense FET, these sense FETs being connected to a respective sigma-delta modulator directly or indirectly.
Preferably, the sigma-delta modulator in the switch-on path measures a current or records a current essentially only during the switched-on phase and the sigma-delta modulator in the recirculation path measures a current or records a current essentially only during the recirculation phase. This means that the current is measured or recorded separately during both phases.
The output signal from the sigma-delta modulator, that is to say the digital measurement signal for the load current, in the switch-on path and the output signal from the sigma-delta modulator in the recirculation path are expediently supplied to a common averaging device which processes the output signals from both paths, or the electronic current measuring circuit is designed accordingly. The effect achieved by this measure is that the two current measurements are totaled, this essentially corresponding to totaling of the two measured currents from both PWM paths in the analog domain. The at least one electronic current measuring circuit has, in particular, at least one circuit means for channel switching, particularly preferably a multiplexer, which is designed such that the signal transmission for the output signal from the respective sigma-delta modulator in the two PWM paths to the common averaging device is effected on the basis of the PWM phase. That is to say that during the switched-on phase the relevant sigma-delta modulator in the switch-on path measures or records the load current, and the output signal from this sigma-delta modulator is transmitted or connected to the common averaging device via this circuit means for channel switching. The behavior is similar with the output signal from the sigma-delta modulator in the recirculation path during the recirculation phase.
The electronic controller is preferably designed such that it assesses the data content of one or more averaging device(s) at least at defined times, after one or more PWM periods, and uses these data to calculate the load current, that is to say the current through the essentially inductive load, directly or indirectly. This implements averaging and undersampling, which smoothes the measurement signal. In addition, the volume of data used for calculating the current in this way is large enough to suppress a form error relatively effectively as a result of the averaging.
The at least one electronic current measuring circuit is preferably designed such that the output signal from the respective sigma-delta modulator in the two PWM paths is additionally transmitted to a respective additional averaging device. These additional data for the current measurement in the respective PWM path are transmitted to an evaluation unit for failsafe or plausibility checking purposes only at defined times or, when there is a defined volume of data, particularly a defined counter reading, according to the design of the electronic current measuring circuit and/or the design of the electronic controller. Particularly preferably, the respective additional averaging device comprises a first counter element, which counts the “ones” from the respective sigma-delta modulator, and a second counter element, which counts the number of samples or the number of digital output data items. The first counter reading, which in principles sums the “ones”, and the second counter reading, which records and sums the number of corresponding samples, are used to form an average which is used to calculate a current value for failsafe purposes. In comparison with this, the common averaging device quite particularly preferably contains only one counter element, which sums the “ones” from both PWM paths. This involves averaging over the defined number of samples from a PWM period or a multiple thereof. On account of the fact that the number of these samples is known, no further counter element is required. The additional data from the additional averaging devices are read for failsafe purposes preferably as part of the inventive method by the software of a microcontroller.
It is expedient that the at least one electronic current measuring is designed such that when very small duty cycles occur, particularly preferably a duty cycle of below 15%, respectively, particularly within at least one defined number of PWM periods, the power driver in the switch-on path is switched on at defined times for a relatively short, defined period in order to increase the volume of data in the current measurement in the switch-on path.
Preferably, the at least one electronic current measuring circuit is designed such that when very large duty cycles occur, particularly preferably a duty cycle of above 85%, respectively, particularly within at least one defined number of PWM periods, the power driver in the switch-on path is switched off at defined times for a relatively short, defined period in order to increase the volume of data in the current measurement in the recirculation path.
Preferably, the at least one electronic current measuring circuit is designed such that the data from at least one averaging device, particularly a counter, are evaluated only at least every three PWM periods in order to increase the size of the database for the current measurement in respect of averaging and thereby to reduce the disturbance to the current control, particularly preferably on account of intentional disturbances for measuring purposes.
The at least one electronic current measuring circuit is preferably designed such that each PWM period contains at least one at least very short switched-on phase and/or likewise each PWM period contains at least one at least very short recirculation phase. In particular, at least one, particularly preferably each, valve actuation circuit is designed accordingly.
It is preferred for at least one electronic current measuring circuit to be in the form of an integrated circuit and particularly to be integrated in the electronic controller, which is also in the form of an integrated circuit.
A method for measuring current in an electronic controller for motor vehicle control systems, wherein sigma-delta modulation in at least one signal path of an electronic current measuring circuit is used to convert an analog measurement signal for a load current into a digital measurement signal for the load current is described herein. In this case, current measurement is preferably performed using the sigma-delta modulation.
It is expedient that the digital measurement signal for the load current in a switch-on path and the digital measurement signal for the load current in a recirculation path is/are respectively summed individually and/or together within a PWM period or a plurality of PWM periods and that this at least one sum is used to calculate a common current value which is taken as a basis for the actual current control. In particular, the digital measurement signals for the load current in the two PWM paths are additionally each summed separately and are particularly preferably stored after a defined time and/or when at least one defined volume of data is present. These additional current measurement data from the respective individual PWM paths are most particularly preferably used for plausibility checking purposes and/or failsafe purposes and evaluated in a microcontroller.
The features of the electronic controller and the features of the exemplary embodiments described are preferably also features which can be implemented in the course of the method.
The electronic controller described herein may be utilized in a motor vehicle control system.
The electronic controller and the method of use thereof are preferably used in electronic motor vehicle brake systems, in which electromagnetic hydraulic valves are actuated by means of pulse width modulation in valve actuation circuits, for setting the hydraulic pressure in wheel brakes on the motor vehicle. Alternatively, provision may be made for them to be used in a servo-assisted steering system in a motor vehicle, wherein the inventive electronic controller actuates the at least one hydraulic valve.
These and other aspects of the invention are illustrated in detail by way of the embodiments and are described with respect to the embodiments in the following, making reference to the Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the current profile through a PWM-controlled inductive load in a control circuit based on the prior art,
FIG. 2 shows just one PWM period from the current profile shown in FIG. 1 based on the prior art,
FIG. 3 shows a schematic illustration of a valve actuation circuit with a recirculation path based on the prior art,
FIG. 4 shows an exemplary embodiment of the electronic current measuring circuit in the electronic controller for the switch-on path,
FIG. 5 shows an exemplary electronic current measuring circuit in the electronic controller which has circuit elements for evaluating both measurement paths,
FIG. 6 shows an alternative exemplary electronic current measuring circuit in the electronic controller, with trimming elements, and
FIG. 7 shows the exemplary time profiles for the voltage on the integrator in the current measuring circuit and for the corresponding load current which is to be measured.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematic illustration of a valve actuation circuit with a power driver in the switch-on path and a power driver in the recirculation path which is shown in FIG. 3 is used to explain the illustrated currents during PWM actuation of the inductive load L. The power driver in the switch-on path is used to connect load L to ground, as a result of which the coil current rises exponentially when the maximum current has not yet been reached. When the PWM actuation is in the switched-off state, the power driver in the recirculation path is on, which means that the coil's transient decay current can flow via the recirculation path. This causes the current to decay exponentially.
FIG. 4 schematically shows an exemplary embodiment of the electronic current measuring circuit in the electronic controller. In this arrangement, this current measuring circuit comprises only the current measurement in the switch-on path of a valve actuation circuit. Load current i L , which is established on the basis of the voltage U Ref across the inductance L and the channel resistance of the power driver 6 to ground when the power driver 6 in the switch-on path is on, and which flows through the inductance L, is intended to be measured. In this case, inductance L corresponds to the inductive behavior of a valve coil. Potential VOx is on the node between L and the power FET. Potential VOx is the reference variable for a control loop connected thereto. The latter contains a summing point 1 at which the reference variable VOx and the feedback variable U r engage, the negative feedback meaning that a difference between these two variables VOx and U r is formed at summing point 1 . By way of example, the summing point 1 is in the form of an analog summator which is provided by an operational amplifier circuit. The summing point 1 has an integrator 2 connected to it which is used as a controller and whose output forms the input potential for the comparator 3 relative to ground. The comparator 3 is part of the control path of the control loop and is operated in clocked fashion, for example. The output of the control loop is fed back via a 1-bit DAC 5 . In this arrangement, the 1-bit DAC is in the form of a switchable current source 4 which drives a defined reference current through a sense FET 7 to ground. This sense FET 7 is on in a control situation and has a defined channel resistance, on the basis of which an appropriate voltage U r is on the node between the 1-bit DAC 5 and the sense FET 7 , said voltage being applied to the summing point 1 in an inverted form as a feedback variable, as a result of which appropriate negative feedback for the control loop is achieved. The gate connections of the power driver 6 and of the sense FET 7 are connected to one another, which means that these two transistors are actuated together, that is to say that the control loop is in operation only when the power driver 6 is on. By way of example, the sigma-delta modulation is performed at a frequency which is 256 times as high as the frequency of the PWM. This corresponds to 256-fold oversampling. To this end, the comparator 3 is operated in clocked fashion at this oversampling frequency. Not only does the output signal from the comparator 3 actuate the switchable current source 4 , but these output data are also transmitted to a counter 8 and stored therein. In this arrangement, the counter 8 counts each “1” from the comparator output. In each PWM period, the counter reading, which has a data word length of 10 bits, for example, is transmitted to an evaluation unit which can take this data word and calculate a current value. By way of example, this current value relates only to the current recorded during the pulse width modulation's switched-on phase, however. Storing or summing the data words (samples) in the counter 8 corresponds to averaging as part of the current measurement. The subsequent undersampling is carried out by reading the counter 8 in time with the PWM. In the figurative sense, the averaging smoothes the current measurement. This is comparable to analog low-pass filtering of the current i L which is to be measured.
As described below by way of example, the proportioning of the measurement range of the current measuring circuit can be chosen: the mirror ratio or the ratio of the drain/source channel resistances (W/L ratio) of the power driver 6 to the sense FET 7 is 500. If the aim is now to measure a current up to a top measurement range limit of 2 A, the switchable current source 4 needs to output a current of 4 mA. In respect of these values, a measurement range of 2 A is obtained by means of the control loop of the sigma-delta modulator. The design of the current source is thus crucial for determining the measurement range. In an exemplary embodiment which is not shown, the switchable current source 4 is designed as a controllable current source for the purpose of setting the measurement range. In one exemplary embodiment which is likewise not shown, an additional, connectable current source or an additional connectable parallel circuit comprising current sources is connected to node 13 , between the switchable current source 4 and the drain connection of the sense FET 4 . This current source or these current sources allow(s) the measurement range of the current measuring circuit to be altered, or for example extended, and connection and disconnection of additional current sources thus implements range switching.
In one exemplary embodiment which is not shown, the integrator 2 is provided by a capacitor having a defined capacitance.
FIG. 5 shows a schematic exemplary embodiment of an extended electronic current measuring circuit. In this arrangement, both in the switch-on path and in the recirculation path the load current is recorded indirectly (in a manner which is not shown) by means of a sigma-delta modulator. The data words from respective sigma-delta modulators are transmitted bit by bit via a respective line to the illustrated portion of the current measuring circuit, the data signal ΣΔon corresponding to the output of the sigma-delta modulator in the switch-on path and the data signal ΣΔrec corresponding to the output of the sigma-delta modulator in the recirculation path. These two data signals are supplied to the multiplexer 9 . The multiplexer 9 is actuated (not illustrated) such that the respective input channel for the path which is currently active is switched on, that is to say the data signal ΣΔon is switched on during the switched-on phase of the PWM and hence during active current recording for the switch-on path, and the data signal ΣΔrec is accordingly switched on during the recirculation phase of the PWM. The output of the multiplexer 9 is connected to a counter 12 which sums and stores the data words from both current recording paths and hence both sigma-delta modulators. The summing of the data signals or samples from both PWM current measuring paths corresponds to summation of both measured currents from the two PWM paths in the analog domain. In addition, the counter 12 forms a general average for the recorded current. By way of example, this average is transmitted to an evaluation circuit or read therefrom every two PWM periods. In this case, the counter reading z is a proportion of a number z max which is obtained from the sum of all possible “1” data words. With 256-fold oversampling and transmission of the counter value on the counter 12 every two PWM periods, respectively, z max is obtained as 512. The measured current value is obtained from the quotient z/z max multiplied by the top limits of the measurement range for the two sigma-delta modulators in the two PWM paths. In addition, the data signals ΣΔon and ΣΔrec are respectively supplied to a further counter 10 , 11 . By way of example, the data words from these two counters 10 , 11 are stored in a memory unit at defined times or when particular data words arise. The memory units are read by the software, these data, which contain information regarding the recorded current in the respective separate PWM paths, being used for failsafe purposes or for plausibility checking.
FIG. 6 shows an exemplary embodiment of the electronic current measuring circuit, which has a respective separate counter 10 , 11 for the data signals from the two sigma-delta modulators ΣΔon and ΣΔrec. These two counters are in a form such that they can store the current measurement data which are captured during a complete PWM period. In addition, this exemplary current measuring circuit has the capability of trimming. This trimming is parameterized in a test mode, for example during production or during the subsequent testing of the current measuring circuit. To test the current measuring circuit, a defined, constant test current is set in the load path. The current measurement in both PWM paths produces a measured current value. In this case, the current measurement in both PWM paths can take place in succession or alternately. Experience has shown that the deviation of the measured current from the defined, constant test current is primarily attributable to an imprecise mirror ratio for the respective power stage to the respective sense FET and/or to an imprecisely set or proportioned current source. The deviation is evaluated during parameterization of the trimming as a correction factor, this correction factor multiplied by the measured current giving the true current value. This correction factor is respectively stored for the switch-on path and the recirculation path in a memory element 15 , 16 , for example a ROM. In the exemplary electronic current measuring circuit, the output of the two counters 10 and 11 is respectively multiplied by the correction factor from the memories 15 and 16 . These two data signals are respectively supplied to a common counter 12 and also individually to a failsafe current measuring section. The transmission of the data to the counter 12 is controlled by means of a signal ‘mode’, which contains the information about whether the switch-on path or the recirculation path, including the respective current measuring path, is currently active. In this context, the signal for the counter 10 is inverted by the inverter 14 , the effect achieved by which is that only one counter 10 , 11 at a time transmits its data. In addition, the signal ‘mode’ is connected to the counter 12 . Furthermore, an evaluation device uses the signal ‘mode’ or its time profile to calculate the size of the duty cycle per respective PWM period. The actuation of the counters 10 , 11 , 12 is comparable to a multiplex operation. By way of example, the data word from the counter 12 is read every two PWM periods and is used for calculating a current value in an evaluation device. This calculation involves weighting the two data signals from the respective PWM paths in terms of the size of the duty cycle (duty cycle weighted average). By way of example, the data word from the switch-on path is multiplied by the duty cycle and the data word from the recirculation path is multiplied by “1-duty cycle”, and these two products are then added.
In an exemplary embodiment which is not shown, the evaluation device is integrated in the counter 12 or alternatively integrated individually or together with the electronic current measuring circuit in the electronic controller, or implemented as software.
The top graph a) in FIG. 7 illustrates the voltage waveform on the integrator of the sigma-delta modulator. The bottom graph b) shows the load current to be measured as a function of time. The voltage profile under a) shows how the voltage potential rises over a certain period on the integrator, this occurring on the basis of the current to be measured and the change in the current to be measured. When the voltage potential on the integrator reaches a defined relative threshold value, the switchable current source within the control loop is switched on and a negative voltage potential, resulting from the current from the switched current source through the sense FET, is applied to the node of the control loop, the result being an abrupt change in the voltage value, as illustrated. Each sudden voltage change in FIG. 7 a ) therefore corresponds to a “1” at the data output of the sigma-delta modulator. At the time t 1 , FIG. 7 a ) shows the voltage profile on the integrator changing between the switch-on path (t<t 1 ) and the recirculation path (t>t 1 ).
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An electronic controller for motor vehicle control systems having at least one valve actuation circuit is described herein. The electronic controller uses pulse width modulation to control the load current (i L ) flowing through an essentially inductive load (L), and has at least one electronic current measuring circuit which has at least one analog/digital converter which converts an analog measurement signal for the load current (i L ) into a digital measurement signal for the load current (i L ). The at least one analog/digital converter is a sigma-delta modulator. A method for measuring current using sigma-delta modulation and to the use of the electronic controller in a motor vehicle brake system is also described herein.
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BACKGROUND
[0001] 1. Field
[0002] Aspects of the invention relate to compartments for storing objects, and more particularly to compartments with movable drawers for storing objects in motor vehicles.
[0003] 2. Discussion of Related Art
[0004] Glove compartments of a motor vehicles with movable drawers are known from U.S. Pat. No. 2,796,310. Here, a lid is attached to the underside of the compartment by a hinge. The drawer in the compartment can be moved forward along guide rails inside of the glove compartment by the motion of a hinged lid. The side walls of the drawer are attached to the lid by a pivoted arm. When the lid is opened, the arm slides the drawer in the guides and causes the drawer to be moved toward an open position to provide access to the drawer. However, the arrangement shown may not provide good access to contents of the drawer if the lid is only partially opened.
SUMMARY
[0005] In one illustrative embodiment, a compartment lid of a motor vehicle is provided. The lid includes a storage drawer which is guided in a guide, and a driving element for driving the storage drawer forwards on opening the lid. The driving element is attached to the lid on one portion and is connected to the storage drawer on another portion. The driving element is part of a transmission lever system which is permanently supportable outside the lid.
[0006] In another illustrative embodiment, a storage compartment apparatus is provided. The apparatus includes a lid that is movable between a closed position and a fully opened position. The lid has a guide. The apparatus further includes a storage drawer guided by the guide and a lever system including a driving element for driving the storage drawer along the guide when the lid is moved between the closed and fully opened positions. One portion of the driving element is connected to the lid and another portion of the driving element is connected to the storage drawer.
[0007] In yet another illustrative embodiment, an apparatus for a storage compartment is provided. The apparatus includes a lid movable to a plurality of positions between a closed position and a fully open position, and a movable storage drawer operatively coupled to the lid. The lid and storage drawer are operatively coupled such that movement of the lid into any one of the plurality of positions between the closed position and the fully open position causes a corresponding movement of the drawer so that access to the drawer can be obtained even when the lid is not in the fully open position.
BRIEF DESCRIPTION OF DRAWINGS
[0008] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Various embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a schematic perspective view of a compartment, such as a glove compartment located in the dashboard of a motor vehicle.
[0010] FIG. 2 is a schematic perspective view of the inside of the glove compartment when the lid is in a slightly opened condition.
[0011] FIG. 3 is a schematic perspective view of the inside of the glove compartment of FIG. 2 when the lid is in a fully opened condition.
DETAILED DESCRIPTION
[0012] According to one aspect of the invention, a storage compartment, such as a glove compartment of a motor vehicle, includes a mechanism that provides access to contents of the storage compartment, even when limited space such as the lack of space in the knee room of a motor vehicle prevents a compartment lid from being fully opened.
[0013] In one illustrative embodiment a compartment lid, such as a glove compartment of a motor vehicle, has a storage drawer that is guided by a guide. A driving element for driving the storage drawer forward when the lid is opened is attached to the lid at a first connection and is connected to the storage drawer at a second connection. The driving element is designed as a part of a transmission lever system which may be permanently supported outside the lid.
[0014] In some embodiments, the distance that the storage compartment moves relative to the position of the compartment lid (that is, the transmission ratio) can be adjusted. Here, the transmission ratio can be set to suit the respective local conditions of a given compartment to ensure that the storage drawer moves open even if the lid is only slightly opened. This can prove beneficial, especially where only slight opening of the lid is possible due to restricted spatial conditions.
[0015] In some embodiments, the lever system has a driving rod connected to the storage drawer by way of a lateral rod that is permanently attached at one end outside of the lid and that is connected at the other end directly or indirectly mounted on the storage drawer. The driving rod can be adjustably attached to the lateral rod and as a result it may be possible to adjust a desired transmission ratio to accommodate structural and/or spatial conditions of the compartment. By altering the lever ratios on the lateral rod, it may be possible to vary the desired transmission ratio to suit the spatial conditions of a particular application. Although the transmission ratio may be adjusted, it should be appreciated that the present invention is not limited in this respect.
[0016] In one embodiment, the driving rod may be rigidly fixed to the lid and flexibly connected to the lateral rod by way of a pull rod. In a similar manner, an end of the lateral rod can be flexibly connected to the storage drawer by a push rod.
[0017] The guide for the storage drawer may be provided at least partially on the interior surface of the lid. In one embodiment, movement of the storage drawer as soon as the lid opening process commences is possible, with the result being that the storage drawer is accessible when the lid has just initially been opened.
[0018] In one embodiment, the lever system may be disposed behind the drawer when seen from the opening direction of the storage drawer. However, it is also possible for the lever system to be disposed laterally with respect to the drawer, as the present invention is not limited in this respect.
[0019] In one embodiment, the lateral rod of the lever system may be aligned parallel to the hinge axis of the lid, which may be beneficial when space is limited. In one embodiment, the hinge axis is disposed on the lower edge of the compartment to be closed.
[0020] Although the embodiments herein are described with reference to a motor vehicle glove compartment, the present invention is not limited in this respect, as the arrangement may be used with other storage compartments.
[0021] Motor vehicles often include glove compartments 2 located in a dashboard 1 that are closed by a compartment lid 3 , as shown in the diagram of FIG. 1 . The illustrated compartment lid 3 has a hinge axis at lower edge 4 of the glove compartment. The lid can rotate through a plurality of positions between a closed position and a fully open position about the hinge axis to open and close the compartment. Compartment lid 3 is shown in FIG. 1 as being at a relatively steep angle and, in some applications, it may be that the lid can only be opened to a limited extent due spatial restrictions, such as restrictions imposed by the knees of a passenger in the motor vehicle. Although the compartment lid is shown disposed generally vertically, the present invention is not limited in this respect, as other suitable orientations may be provided.
[0022] Access to the interior of the glove compartment so that one can insert items into the glove compartment as well as to take items out, even when the lid can only be opened a small amount due to spatial restrictions, may be desirable. In some instances, the angle of opening may result in an access aperture as little as 9 cm or smaller from the upper edge of the lid to the dashboard. Still, in some applications like that shown in FIG. 1 , the angle of opening of the lid may be as small as 10-12 degrees, or smaller, due to spatial restrictions within the car.
[0023] In some embodiments, like that shown in FIG. 2 , a storage drawer is included in the glove compartment. The storage drawer can move forward, along arrow 10 , toward the access aperture when the lid of the compartment is opened as shown by arrow 5 . In this regard, access is provided to contents of the compartment even when the when the lid is opened only by a relatively small angle α.
[0024] In the embodiment of FIG. 2 , compartment lid 3 is opened and closed around a hinge axis 6 , which in one embodiment is essentially horizontal. Guides 8 located on an inner surface 7 of the compartment lid 3 guide the drawer 9 in the direction of arrow 10 when the compartment lid 3 is opened. In the diagram in FIG. 2 the drawer is already projecting beyond the top edge of compartment lid 3 to provide access for the insertion and removal or items. This is possible as the drawer in this case is disposed so as to be movable in guides which are located on the inside of compartment lid 3 and thus the compartment lid does not have to be opened completely in order to enable the drawer to be pushed outwards.
[0025] FIG. 2 also shows an embodiment of a driving mechanism that moves the storage drawer 9 in the forward direction when the lid is opened. The driving mechanism includes a driving rod 11 located in the vicinity of the hinge axis 6 . As shown, the driving rod is rigidly attached to inner surface 7 of compartment lid 3 . The driving rod is connected by an articulated joint, such as a universal joint 12 , to a pull rod 13 . The pull rod is, in turn connected by another articulated joint, such as universal joint 14 , to a lateral rod 15 . The lateral rod is connected at one end 16 by an articulated joint, such as a universal joint 17 , to the dashboard 1 . The other end 18 of the lateral rod 15 is connected by an articulated joint, such as universal joint 19 , to a push rod 20 . The push rod 20 is connected to the drawer 9 by another articulated joint 21 and a rod 22 . Although universal joints are described, the present invention is not limited in this respect as other suitable mechanism may be employed to effect the desired movement.
[0026] As can be seen from FIG. 2 , the push rod 20 is attached adjacent one side of the drawer 9 and the driving rod 11 is attached to compartment lid 3 adjacent an opposed side of the drawer. In one embodiment, the lever length between articulated joints 14 and 17 is considerably smaller than the lever length between articulated joints 14 and 19 . This configuration results in small opening angles of the compartment lid 3 enabling a relatively large forward movement of the drawer (that is, the illustrated driving mechanism has a high transmission ratio). In other embodiments, the transmission ratio can be smaller or larger. Still, in some embodiments, the transmission ratios can be adjusted at will as is desirable and necessary depending on the space and structural conditions.
[0027] FIG. 3 shows the lid completely open insofar as such complete opening is allowed by the spatial constraints around the lid. In FIG. 3 , the lever ratios and the transmission ratio are adjusted to allow a complete pull out of the drawer when the lid reaches a full opening angle α.
[0028] In the arrangement described, the lever system requires relatively little space and is the main component of the lid, apart from an attachment point 17 on the dashboard for the lateral rod 15 .
[0029] Due to the downward movement of the compartment lid around hinge axis 6 in the direction of arrow 5 , the driving rod also moves which brings about a pivoting movement of lateral rod 15 around articulated joint 17 . This movement is transferred according to the transmission ratio to the push rod 20 and brings about a pulling out or pushing out of drawer 9 in the direction of arrow 10 .
[0030] As a result of the storage drawer moving outwards, it is possible to utilize the storage space in the glove compartment to greater effect than is possible in conventional glove compartments. This is particularly the case in applications where there is a limited range of access between the dashboard and the compartment lid. The lever system enables simple manufacture and installation. The construction and likewise the function is uncomplicated and not dependent on electricity.
[0031] The invention can be used wherever there should be a possibility of making optimum use of the interior or the storage despite only limited opening of a lid.
[0032] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
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A compartment, such as a glove compartment of a motor vehicle includes a lid and a movable drawer. A lever system is operatively coupled between the lid and the drawer such that upon opening or closing the lid, the drawer is moved. The lever system may provide a transmission ratio so that optimum adaptation to the spatial conditions is possible. Furthermore, it is possible to pull the storage drawer relatively far forwards even when the compartment lid is only opened slightly.
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FIELD OF THE INVENTION
The present invention relates to chemical mechanical polishing apparatus used in the polishing of semiconductor wafers. More particularly, the present invention relates to methods for enhancing uniformity in the polishing profile of substrates during chemical mechanical polishing (CMP).
BACKGROUND OF THE INVENTION
In the fabrication of semiconductor devices from a silicon wafer, a variety of semiconductor processing equipment and tools are utilized. One of these processing tools is used for polishing thin, flat semiconductor wafers to obtain a planarized surface. A planarized surface is highly desirable on a shadow trench isolation (STI) layer, inter-layer dielectric (ILD) or on an inter-metal dielectric (IMD) layer, which are frequently used in memory devices. The planarization process is important since it enables the subsequent use of a high-resolution lithographic process to fabricate the next-level circuit. The accuracy of a high resolution lithographic process can be achieved only when the process is carried out on a substantially flat surface. The planarization process is therefore an important processing step in the fabrication of semiconductor devices.
A global planarization process can be carried out by a technique known as chemical mechanical polishing, or CMP. The process has been widely used on ILD or IMD layers in fabricating modern semiconductor devices. A CMP process is performed by using a rotating platen in combination with a pneumatically-actuated polishing head. The process is used primarily for polishing the front surface or the device surface of a semiconductor wafer for achieving planarization and for preparation of the next level processing. A wafer is frequently planarized one or more times during a fabrication process in order for the top surface of the wafer to be as flat as possible. A wafer can be polished in a CMP apparatus by being placed on a carrier and pressed face down on a polishing pad covered with a slurry of colloidal silica or aluminum.
A polishing pad used on a rotating platen is typically constructed in two layers overlying a platen, with a resilient layer as an outer layer of the pad. The layers are typically made of a polymeric material such as polyurethane and may include a filler for controlling the dimensional stability of the layers. A polishing pad is typically made several times the diameter of a wafer in a conventional rotary CMP, while the wafer is kept off-center on the pad in order to prevent polishing of a non-planar surface onto the wafer. The wafer itself is also rotated during the polishing process to prevent polishing of a tapered profile onto the wafer surface. The axis of rotation of the wafer and the axis of rotation of the pad are deliberately not collinear; however, the two axes must be parallel. It is known that uniformity in wafer polishing by a CMP process is a function of pressure, velocity and concentration of the slurry used.
A CMP process is frequently used in the planarization of an ILD or IMD layer on a semiconductor device. Such layers are typically formed of a dielectric material. A most popular dielectric material for such usage is silicon oxide. In a process for polishing a dielectric layer, the goal is to remove typography and yet maintain good uniformity across the entire wafer. The amount of the dielectric material removed is normally between about 5000 A and about 10,000 A. The uniformity requirement for ILD or IMD polishing is very stringent since non-uniform dielectric films lead to poor lithography and resulting window-etching or plug-formation difficulties. The CMP process has also been applied to polishing metals, for instance, in tungsten plug formation and in embedded structures. A metal polishing process involves a polishing chemistry that is significantly different than that required for oxide polishing.
Important components used in CMP processes include an automated rotating polishing platen and a wafer holder, which both exert a pressure on the wafer and rotate the wafer independently of the platen. The polishing or removal of surface layers is accomplished by a polishing slurry consisting mainly of colloidal silica suspended in deionixed water or KOH solution. The slurry is frequently fed by an automatic slurry feeding system in order to ensure uniform wetting of the polishing pad and proper delivery and recovery of the slurry. For a high-volume wafer fabrication process, automated wafer loading/unloading and a cassette handler are also included in a CMP apparatus.
As the name implies, a CMP process executes a microscopic action of polishing by both chemical and mechanical means. While the exact mechanism for material removal of an oxide layer is not known, it is hypothesized that the surface layer of silicon oxide is removed by a series of chemical reactions which involve the formation of hydrogen bonds with the oxide surface of both the wafer and the slurry particles in a hydrogenation reaction; the formation of hydrogen bonds between the wafer and the slurry; the formation of molecular bonds between the wafer and the slurry; and finally, the breaking of the oxide bond with the wafer or the slurry surface when the slurry particle moves away from the wafer surface. It is generally recognized that the CMP polishing process is not a mechanical abrasion process of slurry against a wafer surface.
While the CMP process provides a number of advantages over the traditional mechanical abrasion type polishing process, a serious drawback for the CMP process is the difficulty in controlling polishing rates at different locations on a wafer surface. Since the polishing rate applied to a wafer surface is generally proportional to the relative rotational velocity of the polishing pad, the polishing rate at a specific point on the wafer surface depends on the distance from the axis of rotation. In other words, the polishing rate obtained at the edge portion of the wafer that is closest to the rotational axis of the polishing pad is less than the polishing rate obtained at the opposite edge of the wafer. Even though this is compensated for by rotating the wafer surface during the polishing process such that a uniform average polishing rate can be obtained, the wafer surface, in general, is exposed to a variable polishing rate during the CMP process.
Referring to FIG. 1A , a conventional rotary-type CMP apparatus 50 includes a wafer carrier 52 , a polishing pad 56 , and a slurry delivery arm 54 positioned over the polishing pad 56 . The wafer carrier 52 is mounted on the bottom end of a vertical shaft 53 which rotates and presses a semiconductor wafer 66 , mounted on the bottom surface of the wafer carrier 52 , against the upper surface 60 of the polishing pad 56 as the polishing pad 56 is rotated. The slurry delivery arm 54 is equipped with slurry dispensing nozzles 62 which are used for dispensing a slurry solution 64 onto the upper surface 60 of the rotating polishing pad 56 . As the wafer carrier 52 rotates the wafer 66 against the upper surface 60 of the polishing pad 56 , the polishing slurry 64 dispensed thereon by the slurry delivery arm 54 travels with the rotating polishing pad 56 until the polishing slurry 64 moves between the wafer 66 and the polishing pad 56 . Accordingly, the polishing slurry 64 substantially polishes or planarizes the surface of the wafer 66 .
Recently, a chemical mechanical polishing method has been developed in which the polishing pad is not moved in a rotational manner but instead, in a linear manner. It is therefore named as a linear chemical mechanical polishing process, in which a polishing pad is moved in a linear manner in relation to a rotating wafer surface. The linear polishing method affords a more uniform polishing rate across a wafer surface throughout a planarization process for the removal of a film layer from the surface of a wafer. One added advantage of the linear CMP system is the simpler construction of the apparatus, and this not only reduces the cost of the apparatus but also reduces the floor space required in a clean room environment.
A typical linear CMP apparatus 10 is shown in FIG. 1B . The linear CMP apparatus 10 is utilized for polishing a semiconductor wafer 24 , i.e., a silicon wafer in removing a film layer of either an insulating material or a conductive material from the wafer surface. For instance, the film layer to be removed may include insulating materials such as silicon oxide, silicon nitrite or spin-on-glass material or a metal layer such as aluminum, copper or tungsten. Various other materials such as metal alloys or semi-conducting materials such as polysilicon may also be removed.
As shown in FIG. 1B , the wafer 24 is mounted on a rotating wafer holder 18 , which rotates at a predetermined speed. The major difference between the conventional linear CMP apparatus 10 and the predecessor rotary CMP apparatus 50 ( FIG. 1A ) is that a continuous, or endless, polishing belt 12 is utilized instead of a rotating polishing pad. The polishing belt 12 moves in a linear, rather than rotational, manner in respect to the rotational surface of the wafer 24 . The linear polishing belt 12 is mounted in a continuous manner over rollers 14 driven by a motor (not shown) at a predetermined rotational speed. The rotational motion of the rollers 14 is transformed into a linear motion 26 in respect to the surface of the wafer 24 . In the conventional linear CMP apparatus 10 , one or more polishing pads 30 are adhesively joined to the continuous polishing belt 12 on its outer surface that faces the wafer 24 . A polishing assembly 38 is thus formed by the continuous polishing belt 12 and the polishing pad or pads 30 glued or otherwise attached thereto.
During the CMP process, the wafer holder 18 is normally operated in a rotational mode such that a uniform polishing on the wafer 24 can be achieved. To further improve the uniformity of linear polishing, a support housing 32 is further utilized to provide support to a support platen (not shown) during a polishing process. The support platen provides a supporting platform for the underside of the continuous polishing belt 12 to ensure that the polishing pad 30 makes sufficient contact with the surface of the wafer 24 in order to achieve more uniform material removal from the surface layer of the wafer 24 . Typically, the wafer holder 18 is pressed downwardly against the continuous polishing belt 12 and the polishing pad 30 at a predetermined force such that a suitable polishing rate on the surface of the wafer 24 can be obtained. Air pressure is typically further used to push the support platen upwardly against the polishing belt 12 which, in turn, pushes the polishing pad or pads 30 against the wafer 24 . A desirable polishing rate on the wafer surface can therefore by obtained by suitably adjusting the downward force on the wafer carrier 28 , the upward air pressure against the support platen, and the linear speed 26 of the polishing pad 30 . A slurry dispenser 20 , having multiple, typically eleven, slurry dispensing nozzles 34 , as shown in FIG. 1C , is further utilized to dispense a slurry solution 36 through the respective slurry dispensing nozzles 34 onto the polishing pad or pads 30 . As further shown in FIG. 1C , the slurry dispensing nozzles 34 are typically disposed at a distance “D” of 30 mm.
For Cu CMP applications involving low-K IMD (intermetal dielectric) for planarization, interconnect and gap-fill at 0.13 μm and smaller device generations, both the rotary CMP apparatus and the linear CMP apparatus typically utilize a polishing slurry that contains little or no abrasive in order to prevent or minimize damage to the low-k IMDs. For that type of slurry, the within-wafer slurry distribution is of utmost importance in achieving optimal polishing uniformity among all regions on the wafer surface, particularly with regard to 300 mm-diameter wafers.
Referring again to FIG. 1A , the dispensing nozzles 62 of the slurry dispensing arm 54 of the conventional rotary-type CMP apparatus 50 typically dispense the polishing slurry 64 , having little or no abrasive, onto the rotating polishing pad 56 in such a location that the polishing slurry 64 initially contacts the center region of the wafer 66 as the slurry 64 moves beneath the rotating wafer 66 . This causes higher polishing rates at the center relative to the edge regions of the wafer 66 , resulting in an uneven polishing profile across the surface of the wafer 66 .
Referring again to FIG. 1B , the slurry dispenser 20 of the conventional linear CMP apparatus 10 typically includes about eleven of the slurry dispensing nozzles 34 that are spaced along the length of the slurry dispenser 20 . Accordingly, higher polishing rates are achieved on those regions of the wafer 24 that initially contact the polishing slurry 36 on the polishing pads 30 , relative to the other regions on the surface of the wafer 24 . This results in an uneven polishing profile across the surface of the wafer 24 . Accordingly, a new and improved method is needed for dispensing a polishing slurry on a polishing pad in such a position or positions on the polishing pad that polishing rates, and thus, polishing profiles, on the wafer surface are more uniform.
An object of the present invention is to provide a new and improved method for dispensing a polishing slurry onto a polishing pad during a chemical mechanical polishing process.
Another object of the present invention is to provide a new and improved method for enhancing the polishing rates and polishing profile on the surface of a wafer.
Still another object of the present invention is to provide a method for enhancing the polishing rates and profile on the surface of a wafer using a rotary-type chemical mechanical polisher.
Yet another object of the present invention is to provide a method for enhancing the polishing rates and profile on the surface of a wafer using a linear-type chemical mechanical polisher.
A still further object of the present invention is to provide a method for enhancing the within-wafer distribution of slurry applied to a wafer during a chemical mechanical polishing process using a rotary-type polisher or a linear-type polisher.
Yet another object of the present invention is to provide a method for providing a substantially uniform polishing profile on a wafer by chemical mechanical polishing.
Still another object of the present invention is to provide a chemical mechanical polishing method which is well-suited to achieving a substantially uniform polishing profile on a wafer using a polishing slurry having little or no abrasive.
SUMMARY OF THE INVENTION
In accordance with these and other objects and advantages, the present invention is generally directed to new and improved methods for enhancing uniformity in the polishing profile of a substrate during chemical mechanical polishing, particularly for CMP applications in which a polishing slurry having little or no abrasive is used in low-K IMD copper interconnect applications. According to a first embodiment, the method is adapted for a rotary-type chemical mechanical polisher and includes dispensing the polishing slurry onto the rotating polishing pad of the CMP apparatus in a polishing area on the polishing pad that contacts the entire surface area of the substrate. This facilitates substantially equal polishing rates and a substantially uniform polishing profile from the center to the edge regions on the surface of the substrate. According to a second embodiment, the method of the present invention is adapted for a linear-type chemical mechanical polisher and includes increasing the number of nozzles that dispense the slurry onto the polishing pad across the diameter or width of the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1A is a perspective view of a typical conventional rotary-type chemical mechanical polishing apparatus;
FIG. 1B is a perspective view of a typical conventional linear-type chemical mechanical polishing apparatus;
FIG. 1C is a bottom view, partially in section, of a slurry dispenser element of the conventional CMP apparatus of FIG. 1B ;
FIG. 2 is a top view of a rotary-type chemical mechanical polishing apparatus in implementation of one embodiment of the present invention;
FIG. 3 is a top view, partially in section, of a slurry bar element of a rotary-type chemical mechanical polishing apparatus in implementation of another embodiment of the present invention;
FIG. 4 is a top view of a linear-type chemical mechanical polishing apparatus in implementation of another embodiment of the present invention;
FIG. 5 is a bottom view, in section, of a pair of slurry bars used in implementation of the present invention as shown in FIG. 4 ; and
FIG. 6 is a bottom view of a single slurry bar suitable for implementation of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has particularly beneficial utility in the polishing or planarization of semiconductor wafer substrates used in the fabrication of semiconductor integrated circuits. However, the invention is not so limited in application, and while references may be made to such semiconductor wafer substrates, the present invention may be more generally applicable to polishing or planarization of substrates in a variety of mechanical and industrial applications.
Referring initially to FIGS. 2 and 3 , a rotary CMP apparatus 70 in implementation of the present invention includes a circular polishing pad 81 . A wafer carrier 72 , typically mounted on the bottom end of a vertical shaft 73 , is disposed above the upper surface 83 of the polishing pad 81 , in conventional fashion. In use, a wafer 78 is mounted on the bottom surface of the wafer carrier 72 , typically in conventional fashion, and the wafer carrier 72 rotates the wafer 78 against the upper surface of the polishing pad 81 , as indicated by the arrow 82 , as the polishing pad 81 rotates as indicated by the arrow 80 , to polish the surface of the wafer 78 , as hereinafter further described. The apparatus 70 further includes an elongated slurry dispensing bar 74 having a proximal segment 75 and a distal segment 77 that extends from the proximal segment 75 at a center point 74 a . The center point 74 a is disposed directly above a position on the upper surface 83 of the rotating polishing pad 81 which passes beneath the center of the wafer 78 . The proximal segment 75 of the slurry dispensing bar 74 is provided in fluid communication with a supply (not shown) of polishing slurry 79 . The proximal segment 75 and the distal segment 77 each is provided with multiple slurry dispensing nozzles 76 in the bottom thereof for dispensing a polishing slurry solution 79 onto the upper surface 83 of the polishing pad 81 as the polishing pad 81 is rotated. Typically, the proximal segment 75 has a larger number of the slurry dispensing nozzles 76 than does the distal segment 77 . However, in another embodiment of the slurry dispensing bar 84 , shown in FIG. 3 , the distal segment 87 includes a larger number of slurry dispensing nozzles 86 than does the proximal segment 85 .
In application, the rotary CMP apparatus 70 is typically used to polish a wafer 78 in low-k IMD, local copper interconnection applications for fabrication of device features on the order of 0.13 μM and smaller. This type of application utilizes a polishing slurry 79 containing little (typically less than about 1% by weight) or no abrasive particles. While the wafer 78 typically has a diameter of 300 mm, it is understood that the present invention may be adapted for wafers having other diameters or widths. The wafer 78 is rotated against the upper surface 83 of the polishing pad 81 , as indicated by the arrow 82 , as the wafer carrier 72 presses the wafer 78 against the polishing pad 81 and the polishing pad 81 is rotated as indicated by the arrow 80 . Simultaneously, the polishing slurry 79 is dispensed from the slurry bar 74 , through the slurry dispensing nozzles 76 of both the proximal segment 75 and the distal segment 77 , and onto the upper surface 83 of the rotating polishing pad 81 . The slurry dispensing bar 74 may be swept in a side-to-side motion as indicated by the double-headed arrow. Because it is dispensed onto the polishing pad 81 in multiple, adjacent slurry lines across a polishing area on the upper surface 83 of the polishing pad 81 that encompasses the diameter of the wafer 78 , the polishing slurry 79 travels with the rotating polishing pad 81 and then contacts the surface of the wafer 78 across the entire diameter thereof as the polishing slurry 79 is moved by the polishing pad 81 beneath the rotating wafer 78 . Consequently, the within-wafer distribution of the polishing slurry 79 is substantially uniform and the polishing rate across the entire surface area on the wafer 78 is substantially uniform, resulting in a substantially uniform polishing profile through the entire polished surface of the wafer 78 .
Referring next to FIGS. 4–6 , a linear CMP apparatus 90 in implementation of the present invention includes an endless polishing belt 91 , typically fitted with one or multiple olishing pads (not shown) and driven by a roller or rollers (not shown), in conventional fashion. A wafer holder 92 is mounted above the polishing belt 91 , on the bottom end of a shaft 93 , in conventional fashion. In use, a wafer 94 to be polished is mounted on the bottom surface of the wafer holder 92 , typically in conventional fashion, and the wafer holder 92 rotates the wafer 94 as indicated by the arrow 88 as the polishing belt 91 is driven linearly by the rollers (not shown) as indicated by the arrow 89 . A slurry delivery conduit includes a pair of adjacent slurry dispensing bars 95 disposed above the polishing belt 91 , perpendicular to the longitudinal axis thereof, at the “upstream” end of the polishing belt 91 . Each of the slurry dispensing bars 95 is provided in fluid communication with a supply (not shown) of polishing slurry 98 . Each of the slurry dispensing bars 95 is provided with multiple, typically eleven, slurry dispensing nozzles 96 , each having a nozzle opening 97 in the bottom of the corresponding slurry dispensing bar 95 , for dispensing the polishing slurry 98 onto the linearly-traveling polishing belt 91 .
As shown in FIG. 5 , the nozzle openings 97 in each slurry bar 95 are offset or staggered with respect to the nozzle openings 97 in the adjacent slurry bar 95 . The distance “A” between each nozzle opening 97 in one of the slurry dispensing bars 95 and the next nozzle opening 97 in the adjacent slurry dispensing bar 95 is less than about 30 mm. In a preferred embodiment, the slurry dispensing bars 95 have a total of twenty-two nozzle openings 97 and the spacing “A” between adjacent nozzle openings 97 is about 14.28 mm apart. However, it is understood that the slurry dispensing bars 95 may have a greater or lesser number of the nozzle openings 97 , with the spacing “A” between adjacent nozzle openings 97 less than about 30 mm. Each of the nozzle openings 97 has a diameter or width of typically about 2–3 mm. The nozzle openings 97 in the adjacent slurry dispensing bars 95 span an area above the polishing belt 91 that approximates the diameter of the wafer 94 .
In an alternative embodiment, shown in FIG. 6 , a single slurry dispensing bar 99 replaces the two adjacent slurry dispensing bars 95 shown in FIGS. 4 and 5 . Adjacent nozzle openings 100 in the slurry dispensing bar 99 are disposed at a spacing “B” of less than about 30 mm with respect to each other.
In application, the linear CMP apparatus 90 is typically used to polish a wafer 94 in low-k IMD, local copper interconnection applications for fabrication of device features on the order of 0.13 μM and smaller and utilizes a polishing slurry 98 containing little (typically less than about 1% by weight) or no abrasive particles. While the wafer 94 typically has a diameter of 300 mm, it is understood that the present invention may be adapted for wafers having other diameters or widths. The wafer holder 92 rotates the wafer 94 against the polishing belt 91 , as indicated by the arrow 88 , as the wafer holder 92 presses the wafer 94 against the polishing belt 91 and the polishing belt 91 is driven in a linear direction as indicated by the arrow 89 . Simultaneously, the polishing slurry 98 is dispensed from the adjacent slurry dispensing bars 95 , through the nozzle openings 97 of the respective nozzles 96 , and onto the moving polishing belt 91 . Because it is dispensed onto the polishing belt 91 in adjacent slurry lines across a polishing area on the polishing belt 91 that substantially encompasses the diameter of the wafer 94 , the polishing slurry 98 travels with the polishing belt 91 and then contacts the surface of the wafer 94 across the entire diameter thereof as the polishing slurry 98 is moved by the polishing belt 91 beneath the rotating wafer 94 . Consequently, the within-wafer distribution of the polishing slurry 98 is substantially uniform and the polishing rate across the entire surface area on the wafer 94 is substantially uniform, resulting in a substantially uniform polishing profile through the entire polished surface of the wafer 94 .
While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.
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A method for enhancing uniformity in the polishing profile of a substrate during chemical mechanical polishing. According to a first embodiment, the method is adapted for a rotary-type chemical mechanical polisher and includes dispensing the polishing slurry onto the rotating polishing pad of the CMP apparatus in a polishing area on the polishing pad that contacts the entire surface area of the substrate. This facilitates substantially equal polishing rates and a substantially uniform polishing profile from the center to the edge regions on the surface of the substrate. According to a second embodiment, the method of the present invention is adapted for a linear-type chemical mechanical polisher and includes increasing the number of nozzles that dispense the slurry onto the polishing pad across the diameter or width of the substrate.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to exercise devices and, more particularly, to exercise devices adapted for use in a water environment. Specifically, the present invention relates to flotation-type devices intended for use in water exercise and mechanisms for securing the same to a user's arm or leg.
2. Description of the Prior Art
In today's health-minded society, physical exercise along with proper diet and nutrition is being emphasized as part of a regular daily regimen. Consequently, exercise techniques and equipment have evolved accordingly. Water exercise has been found to be one of the most effective and safest forms of exercise. Such exercise includes not only traditional lap swimming but also water aerobics and calisthenics. Such aerobic and calisthenic exercise performed in a water environment utilizes a greater number of muscle groups and is safer due to the elimination of stress caused by impact on hard floor surfaces. Moreover, exercise performed in a water environment permits a relatively earlier rehabilitation therapy for persons recovering from or suffering from illnesses and injuries such as hip replacement, orthoscopic surgery, or multiple sclerosis.
One of the major disadvantages of water calisthenics and therapy is that while arm and leg movements within the water environment are very beneficial and safe, increasing the resistance to such muscular movement is difficult at best. This problem is typically handled in normal dry land exercise routines by adding weights to the arms and legs or by utilizing weight lifting machines. A recent innovation to water exercise to provide such increased muscular resistance to movement includes flotation devices attached to the user's appendages. More specifically, flotation devices held in the hands, attached to the upper arms, or attached to the lower legs, such as the calves or thighs, tends to buoy the appendages to the surface of the water. Thus, the mere muscular effort required to maintain the buoyant flotation devices beneath the water surface enhances the physical exercise. Moreover, movement of appendages within the water requires not only the muscular movement of the appendage to do the exercise per se, but requires a muscular effort to simultaneously resist the buoyant forces of the devices. Thus, such flotation devices secured to a user's appendages increases the resistance to motion of the appendages within the water environment. By varying the position of attachment and/or the buoyancy of the flotation devices, a resistance can be selected to suit the needs and skills of the user.
Previous hereto, such devices were attached to the arms and legs either by creating them sufficiently small so as to provide secure attachment when merely slipping them onto the arm or leg or by securing them to the appendage with Velcro closure mechanisms. The former technique does not permit rapid release of the flotation device in the case of an emergency. Moreover, it does not permit adjustable securement for a variety of appendage sizes. The Velcro closure arrangement does permit adjustable attachment of the device to the appendage of a user. However, such Velcro closure mechanisms have only a limited adjustment capability and tend to slip and inadvertently release after they have been utilized and reutilized over a period of time. Moreover, they tend to fall apart in an aqueous environment due to dissolution of the glue or other adhesives utilized to secure the Velcro closure mechanism to the flotation device itself.
SUMMARY OF THE INVENTION
Accordingly, it is one object of the present invention to provide an exercise device for use in a water environment.
It is another object of the present invention to provide a water exercise device which may be adjustably secured to a variety of user appendage sizes.
It is a further object of the present invention to provide a water exercise device which has a broad tightening capability in attaching it to an appendage of a user and does not fall apart in a water environment.
It is yet a further object of the present invention to provide a water exercise device having a quick release mechanism for adjustably securing the device to the appendage of a user and permitting quick removal thereof in case of an emergency or the like.
To achieve the foregoing and other objects, and in accordance with the purpose of the present invention, an exercise device for use in water is disclosed. The device includes a flotation mechanism having upper and lower inflatable chambers for surrounding the appendage of a user. A member of adjustably securing the device about the user's appendage is disposed about the flotation mechanism intermediate the chambers. Finally, a clamping device is provided for maintaining the securing member in its selected adjustable position and is releasably movable along the securing member to adjust and tighten the securing member about the flotation mechanism.
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 which:
FIG. 1 is a perspective view of the device of the present invention secured about the lower leg portions of a user in an aqueous environment; and
FIG. 2 is an enlarged, side view of the device of the present invention, with some parts in cross-section, illustrating the mechanism for securing the device in a releasable, adjustable manner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the figures, an exercise device 10 is provided for attachment to the appendage, such as the lower leg 12, of a user 14. The device 10 is adapted to provide resistance to muscular movement necessary to move the leg 12 within a water environment 16. The device 10 is buoyant and is preferably a cylindrical inflatable member 18 adapted to slip over the foot and encircle the lower ankle portion of the leg 12.
In preferred form, the inflatable member 18 may be constructed from any suitable, resilient material such as plastic or PVC. It is preferably constructed from relatively heavy PVC material so as to be durable over a prolonged lifetime of use. The inflatable member 18 preferably includes two independently inflatable chambers 20 and 22. Each of the upper and lower chambers 20, 22 includes a device 23 for inflating it. In the illustrated embodiment, each device 23 includes an inflation valve 24 and a plug 26 connected thereto by an arm 27. The plug 26 is adapted to close the valve 24 after each of the chambers 20, 22 has been inflated to the desired amount. The degree of inflation of each of the chambers 20, 22 will vary the amount of buoyancy of the device 10. A central band portion 28 is disposed intermediate the upper chamber 20 and the lower chamber 22. The band portion or member 28 is preferably not inflatable and functions as a connecting member between the two inflatable chambers 20, 22.
As illustrated in FIG. 1, the device 10 is slipped about the leg 12 of the user in its inflated form. It is then secured and tightened to the leg by a securing mechanism 29, as more clearly illustrated in FIG. 2. In preferred form, the securing mechanism 29 includes a cord member 30 which is adapted to generally surround the band portion 28. In preferred form, the cord 30 is constructed from a sturdy, yet relatively thin, rope material. To secure the cord 30 to the member 18, a plurality of apertures 32, 34 are disposed in the band 28. In this manner, and as clearly illustrated in FIG. 2, the cord 30 is laced or interweaved around band 28 by passing along the outer surface of the band through an aperture 32 to the interior surface of the band 28, and then back out through aperture 34 to the outer surface of the band 28. Thus, the cord 30 is firmly maintained in position about the band 28. In preferred form, the band 28 has two layers of material, and the apertures 32, 34 only penetrate the outer layer thereby preventing the cord 30 from rubbing against the skin of a user.
The outermost end portions 36, 38 of the cord 30 are preferably tied or otherwise secured together in a knot formation 40 such that the cord 30 itself loosely encircles the member 18. The cord 30 is then clamped by a clamping assembly 42 proximate the ends 36, 38 to hold the device 10 in place about the arm or leg of a user. In preferred form, the clamp assembly 42 is movable along the cord 30 so as to tighten the cord 30 around the central band 28 to whatever degree desired by the user 14. Moreover, the clamp 42 is preferably spring operated so as to maintain its selected position along the cord 30 when left alone and is movable along the cord 30 only when operated by the user.
A variety of suitable spring actuated clamps may be utilized with the present invention. However, in preferred form, the clamp 42 includes an outer cylinder 44 having transverse aligned apertures 46 disposed in the side portions thereof. A plunger 48 is disposed for longitudinal movement within the cylinder 44. The plunger 48 preferably includes an interior stop member 50 and a head portion 52. The plunger 48 likewise has an aperture 54 disposed transversely to the longitudinal axis thereof. The aperture 54 is adapted for alignment with the apertures 46 to permit the cord 30 to pass entirely through the clamp 42. A spring 56 is disposed between the bottom of the cylinder 44 and the stop member 50. The spring 56 is adapted to bias the plunger 48 outwardly from the cylinder 44, although the plunger 48 is maintained within the cylinder 44 by the stop member 50. Thus, in order to align the apertures 54 and 46 of the plunger 48 and the cylinder 44, the plunger 48 must be depressed at the head 52 and moved longitudinally within the cylinder 44 against the bias of the spring member 56. Once the cord 30 has passed through the aligned apertures 54, 46, the plunger head 52 may be released. At this point, the spring 56 biases the plunger 48 outwardly from the cylinder 44 as illustrated in FIG. 2 so as to clamp the cord 30 within the cylinder 44 by partially misaligning the apertures 54 and 46 with the cord 30 crimped and locked therewithin.
The clamp 42 is maintained in place along the cord 30 by the bias of its own internal spring member 56. The clamp 42 may be moved to any selected position along the cord 30 by pressing down on the head 52 to release the crimping action of the stop member 50 against the cord 30 and realign the apertures 54 and 46. In this manner, the clamp 42 may then slide along the cord 30 to a desired new position, at which time the head 52 is released and the bias of the spring 56 again crimps the cord within the cylinder 44 thereby securing the device 42 in its new position. Thus, when it is desired to tighten the cord 30 about the band 48, the head 52 of the clamp 42 is depressed and the clamp 42 moved along the cord 30 toward the member 18 until the desired tightness is achieved. Generally the desired tightness is inversely proportional to the degree of inflation of the chambers 20, 22. Likewise, the clamp 42 may be released quickly in the case of an emergency situation where it is desired to rapidly remove the device 10 from the leg 12 merely by pressing on the head 52 and pulling the clamp 42 away from the band 48 thereby moving the clamp 42 to a position adjacent the knot 40. This loosens the cord 30 about the band 48 and provides for maximum flexibility of the device 10 on the leg 12. Once this is achieved, the device 10 may be readily removed from the leg 12 by the user.
The above arrangement enables firm attachment of the flotation device to the leg of a user, while permitting easy adjustment by the user at any time. Moreover, the clamping mechanism permits quick release of the clamp and the device from the leg of the user in the case of an emergency or the like. The arrangement of the present invention allows for a broad range of tightening and adjustment without being negatively affected by a water environment over prolonged use. Finally, expensive closure mechanisms, degradable adhesive systems and the like are not required with the arrangement of the present invention. Nonetheless, the present invention provides a water exercise device which is easily put on, removed, and adjustably tightened by the user with minimum effort and time, and which is reliable and stays in place as opposed to prior water exercise and mechanisms.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein but may be modified within the scope of the appended claims.
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An exercise device for use in water includes a flotation member having upper and lower inflatable chambers for surrounding the appendage of a user. A mechanism is disposed about the flotation member intermediate the chambers for adjustably securing the device about the user's appendage. Finally, a clamping device is provided for maintaining the securing mechanism in its selected adjustable position about the user's appendage and is releasably movable along the securing mechanism to adjust and tighten the securing mechanism about the flotation member.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of my previously filed and co-pending application Ser. No. 673,146, filed Apr. 2, 1976 now U.S. Pat. No. 4,023,852.
BACKGROUND OF THE INVENTION
This invention relates generally to rear loading ramp assemblies for flat bed vehicles such as trucks, trailers and the like and to the means for locking said assemblies securely in a horizontal load carrying position as well as for lowering them to an inclined loading or unloading position. The subject invention is characterized by simple construction using readily available component parts.
Tiltable rear loading ramp assemblies for flat bed vehicles are generally known to the prior art. For example, see U.S. Pat. No. 3,441,153 issued to D. D. Handley on Apr. 29, 1969 entitled, "Modified Flat Bed Truck." However, the pivot pin assembly about which the rear portion of the truck bed is tilted from the horizontal load carrying position to an inclined loading position as disclosed in the reference patent is relatively complex in construction. Moreover, the assembly requires a triangular shaped bracket undermounting the truck frame near the pivotal joint of the truck bed which, because of its position, may require being suspended below the truck axle in most cases to provide necessary strength to hold the rear bed portion in its inclined loading position. The suspension of such a bracket below the truck axle constitutes an obstruction which may present difficulties in driving the truck over rough uneven ground such as is often found on construction job sites.
My invention is adapted to substantially overcome these and other difficulties previously encountered with vehicle loading ramps used in the prior art.
SUMMARY OF THE INVENTION
Briefly, in accordance with my invention, there is provided a loading ramp assembly for a load carrying vehicle such as a truck, trailer or the like including a stationary forward load carrying portion and a tiltable rear portion forming a loading ramp and being pivotally attached to the forward portion. A first support means is suspended beneath the forward portion and a second support means is suspended beneath the rear portion. An elongated restraining arm is provided having a rear end portion pivotally connected to the second support means and a front end portion projecting in a forward direction beneath the forward portion. A means is provided for locking the arm in a retracted position between the first and second support means to confine the forward and rear portions in a horizontal load carrying position. Lastly, a means for unlocking the arm from its retracted position is provided to permit the rear portion to tilt downward from the load carrying position toward an inclined loading position thereby forcing the front end portion of the arm forward of its retracted position toward an extended position, the arm being retractable rearward from its extended position as the rear portion is tilted upward from an inclined position toward the load carrying position.
These and other specific objects of may invention will become apparent to those skilled in the art from the following detailed description and attached drawings upon which, by way of examples, only the preferred embodiments of my invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a flat bed trailer having a tiltable rear loading ramp which, when locked in a horizontal position, defines a part of the trailer bed, illustrating one preferred embodiment of the subject invention.
FIG. 2 is a bottom view of the tiltable rear loading ramp portion of the trailer of FIG. 1.
FIG. 3 is an enlarged side elevation view of the tiltable rear load ramp portion of the trailer in FIGS. 1 and 2 shown in the horizontal load carrying position.
FIG. 4 is an enlarged side elevation view of the tiltable rear loading ramp portion of the trailer of FIGS. 1 and 2 shown in the inclined loading position.
FIG. 5 is an enlarged side elevation view of the tiltable rear loading ramp portion of the trailer of FIGS. 1 and 2 as seen from the side opposite that shown in FIGS. 3 and 4.
FIG. 6 shows a rear end elevation view of the trailer of FIGS. 1 and 2.
FIG. 7 is a top view of a front portion of the trailer of FIGS. 1 and 2.
FIG. 8 shows an enlarged top view of a front left corner portion of the trailer of FIGS. 1 and 2.
FIG. 9 shows an enlarged cross-sectional view of a slotted vertical support arm containing a notched restraining are therein as seen along lines 9-9 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the Figures there is shown a trailer 10 for hauling materials, equipment, implements and the like. A suitable hitch 12 is provided for connecting the trailer 10 to a power driven towing vehicle, not shown.
The trailer 10 includes a bed 14 having a horizontal forward portion 14a and a tiltable rear portion 14b constructed of a series of 2 × 4 inch wooden planks 16 layed side by side across a pair of box shaped steel frames 18a,b and 20a,b of hollow rectangular cross-section. A pair of plates 19 formed from 2 × 4 inch boards may also be disposed parallel to one another along the sides of the trailer 10 to prevent materials and equipment from sliding or rolling off the bed 14. The frames 18 and 20 include a pair of forward frame members 18a and 20a which support the forward horizontal bed portion 14a, and a pair of rear frame members 18b and 20b which support the tiltable rear bed portion 14b. The frames 18 and 20 are disposed parallel to one another and may be constructed by welding elongated rectangular plates of steel together to form the hollow rectangular cross-section. A top plate 21 of the frames 18 and 20 is provided with greater width than that of the hollow box shaped portion to produce a flanged edge portion extending along the length of the frames 18 and 20 through which a series of bolts 22 may be inserted to fasten the frames 18 and 20 to the various overlying wooden planks 16. A set of wheels 23 are joined by means of axles 24 upon which the frames 18 and 20 are connected by the usual vehicle suspension springs 26.
The rear tiltable bed portion 14b is pivotally joined to the forward horizontal bed portion 14a by means of a pair of suitable heavy duty pivot pins or shafts 28 and 30 located just under and slightly forward of a gap 32 between the forward and rear portions 14a and 14b. The shafts 28 and 30 are connected through pairs of plates 36 welded to the outside vertical walls of the forward frame members 18a and 20a, respectively, and pairs of plates 38 welded to the inside vertical walls of the rear frame members 18b and 20b, respectively. The plates 36 project rearward beyond the rear ends of the forward frame members 18a and 20a across the gap 32 to a position just forward of the front end of the plate 21 on the rear frame members 18b and 20b such that the upper rear corners of the plates 36 will not catch or bind against said plate when the rear portion 14b is tilted downward from the horizontal to the loading position. The plates 38 project forward beyond the front ends of the rear frame members 18b and 20b across the gap 32 so as to overlap the rear end portions of the plates 36. The plates 38 have upper forward corners 40 which are rounded so that they will not catch or bind against the rear ends of the forward frame members 18a and 20a when the plates 38 and rear portion 14b are pivoted about the pins 28 and 30. In the alternative, the pins 28 and 30 may be replaced by a single elongated pivot pin or shaft extending along and beneath the gap 32 through and between the plates 36 and 38 on both frames 18 and 20. The pair of pins 28 and 30 are preferred over a single elongated pivot pin because less steel is required to form the pivotal joints and because their smaller length makes breakage less likely. To minimize the spacing or width of the gap 32, the pins 28 and 30 may be disposed slightly forward of the gap 32 in notches 34 formed in the rear ends of the forward frame members 18a and 20a (See FIGS. 4 and 5).
The rear portion 14b is raised from the tilted loading position as shown in FIG. 4 to the horizontal load carrying position as shown in FIG. 3 by means of a pair of hydraulic rams 42 pivotally connected between vertical steel support arms 44 and 46 attached to the forward frame members 18a, 20a and the rear frame members 18b, 20b, respectively. The arms 44 and 46 may be welded or bolted to the vertical walls of the frames 18 and 20 opposite one another interior of the bed 14, and should carry the rams 42 at approximately the level of the axles 24, more or less, when the rear portion 14b is in the raised load carrying position. Hydraulic fluid is supplied to the rams 42 through a line 47 from a conventional hydraulic hand pump and reservoir 49 located conveniently at the front of the trailer 10. In the alternative, a pair of air operated rams or any other suitable lifting means could be used in place of the rams 42 of the present example. Such lifting means may also be power driven as well as hand operated provided a suitable power source such as a compressor is available. Such power driven lifting means may readily be employed where the tiltable bed of the instant invention is employed on a truck or other powered vehicle.
The tiltable rear portion 14b is held in the horizontal load carrying position by a pair of slotted restraining arms 48 preferrably formed of steel angle iron and disposed beneath the frames 18 and 20. The arms 48 are pivotally connected to vertically projecting steel support arms 50 welded or bolted to the vertical sidewalls of the rear frame members 18b and 20b and their opposite end portions are slidably inserted through rectangular notches 56 located in a pair of vertical support arms 52, preferrably formed of angle iron, and welded or bolted to the outer sidewalls of the forward frame members 18a and 20a. The arms 48 contain rectangular notches 54 near the slidable free ends thereof adapted to closely fit within the slots 56 of the arms 52 when the tiltable rear portion 14b is in the horizontal load carrying position (see FIGS. 3 and 5). Thus the restraining arms 48 are adapted to carry the full weight of the rear portion 14b when in the load carrying position so that the rams 42 are not used except to lift the rear portion 14b from the loading position to the load carrying position. The horizontal surfaces 58 of the arms 48 are cut away at both ends so that the pivotal ends are free to rotate about pivot pins 59 in the arms 50 and so that the slidable ends containing the notches 54 are free to slide back and forth through the rectangular slots 56 in the arms 52 from an extended loading position as shown in FIG. 4 to a retracted load carrying position as shown in FIGS. 3 and 5.
To lower the rear portion 14b from a horizontal load carrying position as shown in FIGS. 3 and 5 to an inclined loading position as shown in FIG. 4, a pair of rocker arms 60a and 60b fixedly connected to opposite ends of a rotatable shaft 62 are employed. The rocker arm 60a is a generally L-shaped member connected to the end of the shaft 62 immediately beyond the outside vertical wall of the forward frame member 18a. A steel pull rod 64 is pivotally connected at one end to the top of the L-shaped rocker arm 60a and extends forward along the sidewall of the frame member 18a to a hand operated lever assembly 66 conveniently located on the front end of the trailer 10 (See FIG. 8). The assembly 66 includes a fixed arm 68 pivotally connected to one end of the lever arm 70. The other end of the pull rod 64 is pivotally connected to the lever arm 70 between the pivotal and free end thereof. The end of the horizontal portion of the L-shaped rocker arm 60a is pivotally connected to one end of a steel lifting arm 74, the other end of which is pivotally connected to the restraining arm 48.
Accordingly, the rear portion 14b is lowered to the loading position by pulling the lever 70 through a counterclockwise arc, which in turn, pulls the pull rod 64 forward to rotate the rocker arm 60a counterclockwise to lift the arm 74. As the arm 74 lifts the restraining arm 48, the notch 54 is also lifted to allow the weight of the rear portion 14b to push the arm 48 forward through the slot 56. As the arm 48 slides forward through the slot 56, the arm 74 pulls the rocker arm 60a around through a clockwise arc, which in turn, pulls the rod 64 rearward to return the lever arm 70 to a retracted position as shown in FIG. 8. The arm 60b, fixedly connected to the other end of the rotatable shaft 62, follows the action of the rocker arm 60a to lift an arm 76 pivotally connected to the arm 48 which is disposed beneath the frame 20. The arm 60b is thus a follower assembly as opposed to the arm 60a which is an active assembly controlled by the pull rod 64. Since the follower rocker arm 60b is operated by the rotation of the shaft 62 rather than a push rod, it is of simpler construction than the L-shaped rocker arm 60a.
The typical operation of the loader of the instant example is as follows. Assume that the rear portion 14b is tilted in the loading position as shown in FIG. 4. The arms 48 are in an extended position in the slots 56 of the arms 52. The hydraulic pump 49 is activated to energize the rams 42 to lift the rear portion 14b toward the horizontal. The rear portion 14b thus rotates counterclockwise (FIG. 4) until it reaches the horizontal load carrying position wherein the slot 54 drops in the slot 56 (FIGS. 3 and 5). The pressure is then released from the rams 42 so that the arms 48 carry the entire load of the rear portion 14b. To lower the rear portion 14b, the rams are again energized by the pump 49 until the rams 42 assume the load of the rear portion 14b previously carried by the arms 48. A slight upward tilt of the rear portion 14b through a counterclockwise arc may result. With the load released from the arms 48 and being assumed by the rams 42, the pull rod 64 is pulled forward by the lever assembly 66 (FIG. 8) to rotate the rocker arms 60a and 60b to lift the slots 54 of the arms 48 clear of the slots 56. At the same time, hydraulic pressure may be partially released at the pump 49, to allow the weight of the rear portion 14b to force the arms 48 forward through the slots 56 by gravity. The rate at which the rear portion 14b tilts toward the ground can be controlled quite readily by the rate at which hydraulic pressure is released from the rams 42 by the operator of the pump 49.
The length of the rear portion 14b should preferrably be such that the angle of the ramp with the ground is not too steep. Otherwise driving equipment up the ramp onto the horizontal forward portion 14a may become a problem and low slung equipment may tend to drag as it crosses the angle at the gap 32. I have found that a loading angle of no greater than about 30 degrees with the horizontal permits safe loading and unloading of a wide variety of vehicles and equipment onto the trailer 10. To avoid twisting of the rear portion 14b when lowering the same onto uneven ground, I recommend reinforcing the bottom of the rear portion 14b with steel cross bracing 80 such as shown in FIG. 2. The forward ends 82 of the rear frame members 18b and 20b should be tapered diagonally rearward of the gap 32 so that the ends 82 fit approximately flush with the rear ends of the forward support members 18a and 20a when the rear portion 14b is in the loading position as shown in FIG. 4. Similarly, the rear ends 84 of the rear support members 18b and 20b should be tapered diagonally downward and forward at the anticipated loading angle of the tiltable rear portion 14b.
Those skilled in the art will appreciate that my invention is equally applicable to use in connection with trucks, wagons and the like, as well as trailers. The rams 42 can also be used to tilt the rear portion 14b upward through an angle above the horizontal to allow rear loading of the trailer 10 from loading docks which are higher above the ground than the horizontal bed portion 14.
Although the subject invention has been described with respect to specific details of a certain preferred embodiment thereof, it is not intended that such details limit the scope of my invention except insofar as set forth in the following claims.
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A tiltable rear bed portion of a flat bed vehicle including a pair of slotted restraining arms disposed under and along a pair of parallel, spaced bed supporting frames. The arms are pivotally attached on their rear ends to vertical support arms suspended from the frame members on the rear bed portion and are slidably disposed through rectangular slots in a pair of vertical support arms suspended from the frame members on the horizontal forward bed portion. The restraining arms are slotted on the underside of their forward end portions to securely lock within the forward vertical support arms when the rear bed portion is in the horizontal load carrying position. A steel pull rod actuated rocker arm assembly is manually operated by a lever to lift the restraining arms clear of their locked restraining positions in the forward support arms to permit the restraining arms to slide forward through the forward vertical support arms as the rear bed portion is lowered from the horizontal load carrying position to an inclined loading position.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of the Taiwan Patent Application Serial Number 105120500, filed on Jun. 29, 2016, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a polyurethane-based UV absorber and, more particularly, to a polyurethane-based UV absorber which can enhance the light fastness and has washing fastness.
2. Description of Related Art
[0003] Generally, the dyeing process includes pre-treatment, printing and dyeing, and post-treatment. More specifically, pre-treatment includes: singeing, desizing, scouring, bleaching, mercerizing, and heat setting; printing and dyeing includes: dyeing, printing; and post-treatment includes finishing. To prevent having impact on subsequent dyeing process, the aim of pre-treatment is to remove the natural impurities of yarn or fabric, and substances such as sizing agent, auxiliary, and contaminant. Moreover, the purpose of post-treatment is to enhance the usability or property of fabric (such as color fastness, appearance, touch, anti-shrinkage, crease-proof, anti-static electricity, fire-proof, water repellence, and oil repellence), and the process varies with materials and need of fabric.
[0004] Commonly, light fastness enhancer (such as UV absorber and light stabilize) is added in post-treatment to prevent fabric from photo-degradation caused by exposure to sunlight (UV) and maintain the lifespan of fabric. Currently, there are numerous materials, such as solution of zinc oxide (ZnO) and titanium dioxide (TiO 2 ), benzotriazole derivatives, and benzophenone derivatives which are capable of absorbing UV and can be used for treating a textile to enhance light fastness. However, some of those materials only can be used in specific textiles and dyes because of their poor hydrophilicity; some are hydrophilic but lack of great fastness; some have downsides, such as poor fastness and washing fastness; and some are applied with a significant amount of organic solvent or surfactant which is not environment friendly. Especially, the effect of light fastness enhancer decreases dramatically after washing, thus, it has poor washing fastness and shorter lifespan.
[0005] Therefore, it is desirable to provide a light fastness enhancer with following advantages: excellent water dispersibility and washing fastness, environment friendly, and can be used in various materials.
SUMMARY OF THE INVENTION
[0006] To achieve the object, the present invention provides a polyurethane-based UV absorber so as to provide target objects with excellent washing fastness while enhancing light fastness.
[0007] The present invention provides a polyurethane-based UV absorber, obtained by reacting a UV absorber having a reactive hydrogen with a polyisocyanate and a diol or polyol; wherein the weight average molecular weight of the polyurethane-based UV absorber is in a range of 10,000 to 200,000, preferably between 10,000 and 170,000, more preferably between 10,000 and 150,000.
[0008] In the present invention, there is no particular limit to the UV absorber, and it merely needs a reactive hydrogen. Preferably, the reactive hydrogen as functional group is selected from a group consisting of —OH, —NH 2 , and —NH—. More preferably, the UV absorber is selected from the group consisting of benzotriazole UV absorber, benzophenone UV absorber, triazine UV absorber, oxanilide UV absorber, and cyanoacrylate UV absorber. Most preferably, the said UV absorber is a benzotriazole UV absorber.
[0009] In the present invention, polyisocyanate can include two or more —NCO functional group, preferably three —NCO functional group. After the reaction between the UV absorber and the polyisocyanate, the reactive hydrogen of UV absorber can be bonded with the —NCO functional group of polyisocyanate. More particularly, said polyisocyanate is selected from a group consisting of isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), 1,3-Bis(isocyanatomethyl)benzene (XDI), tetramethyl xylylene diisocyanate (TMXDI), 2,2,4-trimethylhexamethylene diisocyanate (HDI TRIMER), hexamethylene diisocyanate biuret (HDB), and a mixture thereof. Preferably, the polyisocyanate is selected from the group consisting of 2,2,4-trimethylhexamethylene diisocyanate (HDI TRIMER), Hexamethylene diisocyanate biuret (HDB) and a mixture or polymer thereof.
[0010] In the present invention, the diol or polyol can include two or more —OH functional group, therefore, the diol or polyol can be connected to —NCO functional group after the reaction between diol or polyol and polyisocynante is completed. The diol or polyol is selected from the group consisting of anionic diol or polyol, cationic diol or polyol, nonionic diol or polyol, and a mixture thereof. More specifically, the anionic diol or polyol is selected from the group consisting of 2,2-Bis(hydroxymethyl)butyric acid (DMBA), 2,2-Bis(hydroxymethyl)propionic acid (DMPA), 1,4-butanediol-2-Sodium, and a mixture thereof; the cationic diol or polyol is selected from the group consisting of N-methyldiethanolamine (MDEA), methyldiethanolamine (MPEDEA), Triethanolamine, and a mixture thereof; nonionic diol or polyol is selected from the group consisting of ethylene glycol (EG), Diethylene glycol (DEG), 1,4-butanediol (BDO), Polytetramethylene ether glycol (PTMEG), Polyethylene glycol (PEG), Polypropylene glycol (PPG), polyethylene adipate (PEA), polypropylene adipate (PBA), and a mixture thereof. Preferably, the diol or polyol is selected from the group consisting of 2,2-Bis(hydroxymethyl)butyric acid (DMBA), Polyethylene glycol (PEG), N-methyldiethanolamine (MDEA), and a mixture thereof.
[0011] In the present invention, the polyurethane-based UV absorber may further include a chain extender. The chain extender is selected from the group consisting of polyamines which comprises two or more reactive hydrogen, and a mixture thereof. The reactive hydrogen as functional group is selected from the group consisting of —OH, —NH 2 , and —NH—. After the reaction between the chain extender and polyisocyanate is completed, the reactive hydrogen can be connected to the —NCO functional group of polyisocyanate. Specifically, the chain extender is selected from the group consisting of ethyleneamines based polyamines (such as ethylene diamine (EDA), diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA), and Aminoethylethanolamine (AEEA)), polyetheramines based polyamines (for example, JEFFAMINE (commercially available from Huntsman)), hydrophilic polyamines (such as aliphatic diamine sulphonate, amino acid, and diaminobenzoic acid), and hydrophobic polyamines (such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis-(4-amino-cyclohexyl)-methane, bis-(4-amino-3-methylcyclohexyl)-methane, 1,6-diaminohexane). Preferably, the chain extender is selected from the group consisting of ethylene diamine (EDA), Aminoethylethanolamine (AEEA), diethylene triamine (DETA), triethylene tetramine (TETA), aliphatic diamine sulphonate, and a mixture thereof. More preferably, the chain extender is selected from the group consisting of ethylene diamine (EDA), aminoethylethanolamine (AEEA), and a mixture thereof.
[0012] The structure of the polyurethane-based UV absorber monomer can be represented by formula (I):
[0000]
[0013] wherein A is UV absorber which includes reactive hydrogen, B is polyisocyanate, and C is diol or polyol.
[0014] When the polyurethane-based UV absorber includes the chain extender, the structure of the monomer of polyurethane-based UV absorber can be represented by formula (II):
[0000]
[0015] wherein A, B, and C has the same definition as that defined in the formula (I), and D is chain extender.
[0016] The present invention further provides a composition for enhancing light fastness including said polyurethane-based UV absorber, and it can be applied on elastomers, sealants, adhesives, or coatings. Furthermore, the composition for enhancing light fastness may further include an additive which is selected from the group consisting of a neutralizing agent, a carrier, a diluent, an excipient, and a stabilizer.
[0017] The said polyurethane-based UV absorber and the composition for enhancing light fastness have excellent adhesiveness to textile, and can be used to treat various materials to enhance light fastness and washing fastness. Therefore, it meets the needs of industry. In addition, said polyurethane-based UV absorber is used without toxic chemicals and additional surfactant, and it is used with extremely low amount of organic solvent, thus, it meets the requirements of environment friendliness.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The following specific examples are used to illustrate the present invention. Any person who is skilled in the art can easily conceive other advantages and effects of the present invention. Although the present invention has been explained in relation to its preferred embodiment, many other possible modifications and variations can be made without departing from the spirit and scope of the present invention as hereinafter claimed.
[0019] Unless specified otherwise, singular words “a” and “the” used in the invention specification and claims include plural subjects.
[0020] Unless specified otherwise, term “or” used in the invention specification and claims include meaning of and/or.
[0021] The term “weight average molecular weight” here is Mw value of polystyrene measured by using gel permeation chromatography (GPC) solvent: tetrahydrofuran (THF).
[0022] The methods of preparation are described by the following embodiments in details, and the similar methods of embodiments can be used to prepare said polyurethane-based UV absorber. The methods of preparing polyurethane-based UV absorber (such as synthetical method, reaction condition, and sequences) and material are not limited to the present invention.
[0023] The polyurethane-based UV absorber has excellent water dispersibility, permeability, and storage stability. Furthermore, it can be widely applied. The polyurethane-based UV absorber can be applied on various materials including, but not limited to, fiber materials, leather materials (such as a natural leather and synthetic leather), foam, and wood. Particularly, the applied fiber materials includes nature fibers (such as plant fibers, animal fibers (for example, wool) and mineral fibers), and artificial fibers (such as regenerated fibers, semi-synthetic fibers, and synthetic fibers (such as polyester fiber and nylon fibers). Preferably, the fiber material is a natural cellulose fiber (such as cotton, linen, flax, hemp, and ramie), an animal fiber (for example, wool), a regenerated fiber (for example, viscose rayon), and a synthetic fiber (such as polyester fibers and nylon fibers). More preferably, the fiber material is cotton. The polyurethane-based UV absorber can be also applied on mixed fibers, blended fabrics or mixed fabrics containing aforementioned fiber materials.
[0024] The light fastness enhancer can optionally include other auxiliaries such as, but not limited to, UV absorber, light stabilizer, antioxidant, surfactant, leveling agent, thickener, defoamer and a mixture thereof.
[0025] The present invention will be illustrated by preferred embodiment. However, the following examples should not be constructed in any way to limit the scope of the present invention. Unless specified otherwise, percentage referring content and mass used in examples and comparative examples are calculated by weight.
Example 1—Preparation of Compound 1
[0026] 68.2 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a flask, and then added with 50.5 g of HDI TRIMER. The mixture was then heated to 65-75° C. When the NCO group was titrated till the end point of the reaction (Free NCO %/=7%), 5.4 g of DMBA was added. The mixture is titrated till NCO group was titrated to the end point of the reaction (Free NCO %/=3.99%). Then 16.0 g of acetone and 5.4 g of N,N-Dimethylethylamine were added. Consequently, the prepolymer 1 was obtained.
[0027] Prepolymer 1 was added with 300.0 g of deionized water, and then stirred at a high speed. The mixture was added with 2.8 g of EDA and 1.6 g of AEEA as chain extender, and then stirred till dispersed completely. Consequently, the compound 1 (Mw=43,800, measured by GPC) was obtained.
Example 2—Preparation of Compound 2
[0028] 70.0 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a flask, and then added with 50.5 g HDI TRIMER. The mixture was heated to 65-75° C. When the NCO group was titrated till the end point of the reaction (Free NCO %=6.6%), 2.2 g of DMBA and 10.5 g of PEG300 (polyethylene glycol, Mw=300) were added. Then the NCO group was titrated till the end point of the reaction (Free NCO %=2.8%), and then 16.0 g of acetone and 2.6 g of N,N-Dimethylethylamine were added. Consequently, the prepolymer 2 was obtained.
[0029] Prepolymer 2 was added with 300.0 g of deionized water, and then stirred at a high speed. The mixture was added with 2.4 g of EDA and 1.4 g of AEEA as chain extender, and then stirred till dispersed completely. Consequently, the compound 2 (Mw=13,200, measured by GPC) was obtained.
Example 3—Preparation of Compound 3
[0030] 70.0 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a flask, and then added with 50.5 g HDI TRIMER. The mixture was heated to 65-75° C. When the NCO group was titrated till the end point of the reaction (Free NCO %=7.1%), 1.79 g of MDEA and 10.5 g of PEG300 were added. Then the NCO group was titrated till the end point of the reaction (Free NCO %=3.67%), and then 16.0 g of acetone and 1.8 g of acetic acid were added. Consequently, the prepolymer 3 was obtained.
[0031] Prepolymer 3 was added with 300.0 g of deionized water, and then stirred at a high speed till dispersed completely. Consequently, compound 3 (Mw=131,700, measured by GPC) was obtained.
Example 4—Preparation of Compound 4
[0032] 70.0 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a flask, and then added with 50.5 g HDI TRIMER. The mixture was heated to 65-75° C. When the NCO group was titrated till the end point of the reaction (Free NCO %=6.67%), 3.57 g of MDEA was added. Then the NCO group was titrated till the end point of the reaction (Free NCO %=3.7%), and then 16.0 g of acetone and 4.32 g of acetic acid were added. Consequently, the prepolymer 4 was obtained.
[0033] Prepolymer 4 was added with 300.0 g of deionized water, and then stirred at a high speed till dispersed completely. Consequently, the compound 4 (Mw=74,400 measured by GPC) was obtained.
Example 5—Preparation of Compound 5
[0034] 70.0 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a flask, and then added with 47.8 g HDB. The mixture was heated to 65-75° C. When the NCO group was titrated till the end point of the reaction (Free NCO %=7.2%), 2.2 g of DMBA and 10.5 g of PEG300 were added. Then the NCO group was titrated till the end point of the reaction (Free NCO %=3.5%), 16.0 g of acetone and 2.6 g of N,N-Dimethylethylamine were added. Consequently, the prepolymer 5 was obtained.
[0035] Prepolymer 5 was added with 300.0 g of deionized water, and then stirred at a high speed till dispersed completely. Consequently, the compound 5 (Mw=91,900 measured by GPC) was obtained.
[0036] The aforementioned monomer structure of compound 1 and compound 2 can be represented by formula (II), and compound 3 to 5 can be represented by formula (I):
[0000]
[0037] wherein the average weight molecular weight (Mw) of A, B, C, D, and other compounds are shown in Table 1.
[0000]
TABLE 1
Com-
Compound 1
Compound 2
Compound 3
Compound 4
pound 5
A
UVA
UVA
UVA
UVA
UVA
B
HDI
HDI
HDI
HDI
HDB
TRIMER
TRIMER
TRIMER
TRIMER
C
DMBA
DMBA/
MDEA/
MDEA
DMBA/
PEG300
PEG300
PEG300
D
EDA/AEEA
EDA/AEEA
—
—
—
Mw
43,800
13,200
131,700
74,400
91,900
UVA is UV absorber, which is α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl).
Comparative Example 1
[0038] 55.67 g of α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl) (Everlight Chemical Industrial Corporation) was provided in a 250 ml flask, and then stirred. Then heated to 50° C., and then added with 22.20 g of HDI TRIMER and 19.50 g of DMAc (N,N-Dimethylacetamide). The mixture was heated to 90° C., and the reaction was performed for 2-3 hours (the NCO group was titrated till the end point of the reaction). Then, the mixture was cooled down to 70° C., and then added with 2.59 g of MDEA (N-methyldiethanolamine), which is neutralized by 1.30 g of AcOH (acetic acid) in advance, and 7.20 g of DMAc. The mixture was heated to 90° C., and the reaction was performed for 2-3 hours (the NCO group was titrated till the end point of the reaction). The mixture was cooled down to 50° C., and then the comparative example 1 was obtained.
[0039] The aforementioned monomer structure of comparative example 1 can be represented by formula (I):
[0000]
[0040] wherein A is α-[3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-ω-hydroxypoly(oxo-1,2-ethanediyl), B is HDI TRIMER, and C is MDEA. The average weight molecular weight of comparative example 1 is about 3608.4.
Test Example 1—Light Fastness Test
[0041] The solution (80 g/l-120 g/l) of aforementioned examples and comparative examples were poured over the roller of a padding machine to proceed padding treatment for dyed sample fabrics (13 cm×5 cm) under less than 80% of wet pickup condition, and then dyed sample fabrics were put in an oven at 60° C. for 15 minutes. After drying, dyed sample fabrics were divided into two groups which are non-washed group and washed-five-times group. Non-washed group was conducted light fastness testing according to AATCC 16-2010 method 3 (20 light units), and measured the degree of fading by a spectrophotometer after exposure to artificial daylight. The results were graded by the instrument. Furthermore, the washed five-times-group was conducted a light fastness testing after washing testing as follows.
Test Example 2—Washing Test
[0042] The washed five-times-group was provided, and added with the accompanying fabric, which is 50/50 poly-cotton blend (92 cm×92 cm), to 1.8 kg in total. Then added with 66 g of washing powder (1933 AATCC washing powder) to wash, and the water temperature was set as 49° C.±3° C. The washing procedure was set as standard setting: water level is 18±0.5 gal; agitation speed is 179± 2 spm; washing time is 12 minutes; spin speed is 645±15 rpm; final spin time is 6 minutes. The dyed sample fabrics were added with 66 g of washing powder to proceed next washing cycle without drying until 5 washing cycles were finished. The washing procedure is conducted according to AATCC 135-2004′ method.
[0043] The results of non-washed group and washed five-times-group are shown in table 2 and table 3 respectively. The Blank is dyed sample fabrics without adding any solution.
[0000]
TABLE 2
Comparative
example 1
Compound 1
Compound 2
Compound 3
Compound 4
Compound 5
Blank
Grade: 3
Grade: 3.5
Grade: 3
Grade: 2.5
Grade: 2.5
Grade: 2.5
Non-
Grade: 4
Grade: 4.5
Grade: 4
Grade: 3.5
Grade: 3.5
Grade: 3.5
washed
Enhanced
1
1
1
1
1
1
grade
of light
fastness
[0000]
TABLE 3
Comparative
example 1
Compound 1
Compound 2
Compound 3
Compound 4
Compound 5
Blank
Grade: 3
Grade: 3.5
Grade: 3
Grade: 2.5
Grade: 2.5
Grade: 2.5
Washed
Grade: 3
Grade: 4
Grade: 4
Grade: 3
Grade: 3.5
Grade: 3.5
five times
Enhanced
0
0.5
1
0.5
1
1
grade
of light
fastness
[0044] It can be seen that light fastness of dyed sample fabrics was enhanced by 1 grade after added with solution of compounds according to table 2. In accordance with table 3, the light fastness of dyed sample fabrics added with comparative example 1 solution decreased after washing five times. By contrast, the light fastness of dyed sample fabrics added with solution of examples 1-5 were still enhanced by 0.5-1 degree. Further, examples 1 and 2 comprise chain extender respectively and examples 3-5 do not comprise chain extender; by comparison, both of them provide dyed sample fabrics with excellent light fastness and washing fastness.
[0045] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
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A polyurethane-based UV absorber, obtained by reacting a UV absorber having a reactive hydrogen with a polyisocyanate and a diol or polyol; wherein the weight average molecular weight of the polyurethane-based UV absorber is in a range of 10,000 to 200,000.
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BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor integrated circuit using bipolar transistors and, more particularly, a current source circuit which is improved in respect of the variation in the input/output current ratio due to the dispersions of elements and the change in ambient temperature.
FIG. 1 shows the constitutional arrangement of a conventional synchronous detection circuit as an example of a semiconductor integrated circuit provided with a current source circuit.
In this synchronous detection circuit, an input signal VIN superimposed on a DC bias voltage VB is supplied to the base of an NPN transistor Q1. Further, two pairs of NPN transistors Q2, Q3 and Q4, Q5 arranged in such a manner that the emitters of the transistors in the respective pairs are connected to each other are controlled in synchronism with switch control signals SW1, SW2 supplied to the bases of the respective transistors, whereby, from the common collectors of the transistors Q3, Q5, a detection output signal OUT is derived.
In this case, used as a load to the transistors Q2, Q3, Q4 and Q5 is a current mirror circuit (current source circuit) 10 comprised of PNP transistors Q6, Q7, Q8 and Q9, an NPN transistor Q10, and resistors R1, R2 and R3.
In this current mirror circuit 10, the emitter of the transistor Q6 is connected to a voltage node 11 through the resistor R1. A positive DC bias voltage VA is supplied to the node 11. The collector of the transistor Q6 is connected to a current input terminal 12. Also connected to this current input terminal 12 are the respective collectors of the transistor Q2, Q4. The emitter of the transistor Q7 is connected to the voltage node 11 through the resistor R2. The base of the transistor Q7 is connected commonly to the base of the transistor Q6, and the collector thereof is connected to a current output terminal 13. Also connected to this current output terminal 13 are the respective collectors of the transistors Q3, Q5. The emitter of the transistor Q9 is connected to the voltage node 11 through the resistor R3. The base and collector of the transistor Q9 are connected to the common bases of the transistors Q6 and Q7. The transistor Q9 and the resistor R3 are provided for preventing the current mirror circuit 10 from oscillating.
The collector of the transistor Q10 is connected to the common base of the transistors Q6 and Q7. The emitter of the transistor Q10 is connected to the emitter of the transistor Q8. The base of the transistor Q8 is connected to the collector of the transistor Q6, while the collector of the transistor Q8 is connected to a voltage node 14 which is supplied with the earth voltage.
Further, the circuit consisting of NPN transistors Q11, Q12, Q13 and Q14, resistors R4 and R5, and constant-current sources I1, I2, I3 and I4 feeds the common emitter of the transistors Q2, Q3 and the common emitter of the transistors Q4, Q5 with a current corresponding to the input signal VIN or a current corresponding to the constant voltage generated by a constant-voltage generation circuit to be described later, the circuit being constituted as follows:
That is, the bases of the transistors Q11, Q12 are connected to the emitter of the transistor Q1. The collector of the transistor Q11 is connected to a node N1 which is supplied with the constant voltage, while the emitter thereof is connected through the constant-current source 11 to the voltage node 14 placed at the earth voltage. The collector of the transistor Q12 is connected to the common emitter of the transistors Q2, Q3, while the emitter thereof is connected to the voltage node 14 through the constant-current source I2. The bases of the transistors Q13, Q14 are connected to the node N1. The collector of the transistor Q13 is connected to the common emitter of the transistors Q4, Q5, while the emitter thereof is connected to the voltage node 14 through the constant-current source I3. The collector of the transistor Q14 is connected to the emitter of the transistor Q1, while the emitter thereof is connected to the voltage node 14 through the constant-current source I4.
Further, between the emitters of the transistors Q12, Q13, the resistor R4 is connected, while between the emitters of the transistors Q11, Q14, the resistor R5 is connected.
The circuit consisting of PNP transistors Q15, Q16, Q17, NPN transistors Q18, Q19, and a resistor R6 constitutes a constant-voltage generation circuit. That is, the emitter of the transistor Q15 is connected to the voltage node 11 through the resistor R6. The emitter of the transistor Q16 is connected to the voltage node 11, while the base thereof is connected to the base of the transistor Q15. Further, the base and collector of the transistor Q16 are short-circuited to each other. The collector and base of the transistor Q18 are connected to the collector of the transistor Q15. Further, a common connection node N2 between the collector and base of the transistor Q18 is connected to the base of the transistor Q10. The emitter of the transistor Q17 is connected to the emitter of the transistor Q18.
The collector of the transistor Q19 is connected to the collector of the transistor Q16. Further, the bases of the transistors Q17, Q19 are commonly connected to each other, and, to these commonly connected bases, a DC bias voltage VB is supplied. The collector of the transistor Q17 is connected to the voltage node 14, and the emitter of the transistor Q19 is connected to the node N1.
By the way, in a current mirror circuit in general, there is provided means for correcting the error in the input/output current ratio which is caused by the base currents of transistors etc.; and, in the case of the current mirror circuit 10 shown in FIG. 1, the transistors Q8 and Q10 are provided for correcting the error in the input/output current ratio due to the base current of the transistors Q6, Q7 and the base-collector current of the transistor Q9, and further, a current of a value corresponding to the currents which cause the error is made to flow to the earth voltage node through the transistor Q8.
However, the base current itself of the correcting transistor Q8 joins to the collector current of the transistor Q6; and thus, the base current causes an error in the input/output current ratio of the current mirror circuit.
Due to this, in the circuit shown in FIG. 1, a correction circuit 20 is further provided to correct the error due to the base current of the transistor Q8.
This correction circuit 20 is comprised of PNP transistors Q20, Q21, and a resistor R7. That is, the emitter of the transistor Q20 is connected to the voltage node 11 through the resistor R7, while the base thereof is connected to the common base of the transistors Q6, Q7 in the current mirror circuit 10. The emitter of the transistor Q21 is connected to the collector of the transistor Q20, the base thereof is connected to the collector of the transistor Q7 in the current mirror circuit 10, and the collector thereof is connected to the voltage node 14.
In the correction circuit 20, the transistor Q20 constitutes a current mirror together with the transistor Q6 in the current mirror circuit 10. Further, by setting the value of the resistor R7 so that the base currents of the transistors Q8 and Q21 may become equal to each other, the sum of the collector current of the transistor Q6 and the base current of the transistor Q8 and the sum of the collector current of the transistor Q7 and the base current of the transistor Q21 are equalized to each other. By so doing, the error in the input/output current ratio caused by the base current of the transistor Q8 is corrected.
By the way, in the conventional circuit shown in FIG. 1, the value of the base current of the transistor Q8 becomes 1/hfe (wherein hfe stands for the current amplification factor) times as large as the total sum of the base current of the transistor Q6, the base current of the transistor Q7, the base current and collector current of the transistor Q9, and the base current of the transistor Q20. The correction for the base current of the transistor Q8 is made by only the base current (which is 1/hfe times as large as the collector current of the transistor Q20) of the transistor Q21.
Due to this, even if the value of the base current of the transistor Q21 is set or adjusted under a certain condition, an unbalance is caused between the base currents of the transistors Q8 and Q21 in some cases due to the dispersions of the elements and the variation in ambient temperature. As a result, there arises the problem that the values of the currents which flow to the node 13 at which the detection output signal OUT is derived and to the node N3 which is paired with the node 13 and is the common collector node of the transistors Q2, Q4 are varied due to the dispersions of the elements and the variation in the ambient temperature, as a result of which the input/output current ratio comes to vary.
Further, so far, the potential at the node N3 paired with the node at which the detection output signal OUT is derived is determined by the VB+VBE (Q17)+VBE (Q18)-VBE (Q10)-VBE (Q8), wherein VBE (Qi) (i=1, 2 . . . ) stands for the base-emitter voltages of the respective transistors. However, the potential at the node at which the detection output signal OUT is obtained is not determined unconditionally, becoming indeterminate. Due to this, there has also been caused the problem that the values of the emitter-collector voltages VCE of the transistors Q6 and Q7 become different from each other; and, by the influence of the early effect, the collector currents of the transistors Q6 and Q7 become unbalanced.
BRIEF SUMMARY OF THE INVENTION
Thus, it is the object of the present invention to provide a current source circuit constituted in such a manner that the input/output current ratio of the current mirror circuit can always be maintained constant without being affected by the dispersions of the elements and the variation in the ambient temperature.
Another object of the present invention is to provide a current source circuit constituted in such a manner that the occurrence of an unbalance between the collector currents by the influence of the early effect based on the difference between the emitter-collector voltages of a pair of transistors constituting a current mirror circuit can be prevented.
According to an embodiment of the present invention there is provided a current source circuit comprising: a first voltage node to which a first voltage is supplied; a second voltage node to which a second voltage lower than the first voltage is supplied; a current mirror circuit including a first transistor of a first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a second transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the first transistor, a third transistor of a second polarity opposite to the first polarity, the third transistor having a base, an emitter and a collector, the collector being connected to a base common connection node of the first and second transistor, and a fourth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to the emitter of the third transistor, the base being connected to the collector of the first transistor, the collector of the fourth transistor being connected to the second voltage node, wherein the collectors of the first and second transistors are used as current input and output terminals of the current mirror circuit; and a correction circuit including a fifth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a sixth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the fifth transistor, the collector being connected to the base of the third transistor, a seventh transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to a base common connection node of the fifth and sixth transistors, the base being connected to the collector of the fifth transistor, an eighth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to the collector of the seventh transistor, the base being connected to the collector of the second transistor, the collector of the eighth transistor being connected to the second voltage node, and a ninth transistor of the second polarity which has a base, an emitter and a collector, the base and the collector being connected to the base of the third transistor, the emitter being connected to the emitter of the eighth transistor.
According to another embodiment of the present invention, there is provided a current source circuit comprising: a first voltage node to which a first voltage is supplied; a second voltage node to which a second voltage lower than the first voltage is supplied; a current mirror circuit including a first transistor of a first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a second transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the first transistor, a third transistor of the first polarity which has a base, an emitter, a collector, the emitter being connected to a base common connection node of the first and second transistors, the base being connected to the collector of the first transistor, the collector of the third transistor being connected to the second voltage node, and a fourth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base and the collector being connected to the base common connection node of the first and second transistors, wherein the collectors of the first and second transistors are used as current input and output terminals of the current mirror circuit; and a correction circuit including a fifth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a sixth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the fifth transistor, the collector being connected to the second voltage node, a seventh transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage note, the base being connected to a base common connection node of the fifth and sixth transistors, an eighth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to a base common connection node of the fifth, sixth and seventh transistors, the base being connected to the collector of the fifth transistor, the collector of the eighth transistor being connected to the collector of the seventh transistor, and a ninth transistor of a second polarity which has a base, an emitter and a collector, the emitter being connected to the collector of the eighth transistor, the base being connected to the collector of the second transistor, the collector of the ninth transistor being connected to the second voltage node.
According to still another embodiment of the present invention, there is provided a current source circuit comprising: a first voltage node to which a first voltage is supplied; a second voltage node to which a second voltage lower than the first voltage is supplied; a current mirror circuit including a first transistor of a first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a second transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the first transistor, a third transistor of a second polarity opposite to the first polarity, the third transistor having a base, an emitter and a collector, the collector being connected to a base common connection node of the first and second transistors, a fourth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to the emitter of the third transistor, the base being connected to the collector of the first transistor, the collector of the fourth transistor being connected to the second voltage node, and a fifth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base and the collector being connected to the base common connection node of the first and second transistors, wherein the collectors of the first and second transistors are used as current input and output terminals of the current mirror circuit; and a correction circuit including a sixth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, a seventh transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected commonly to the base of the sixth transistor, the collector being connected to the second voltage node, an eighth transistor of the first polarity which has a base, an emitter and a collector, the emitter being coupled to the first voltage node, the base being connected to a base common connection node of the sixth and seventh transistors, the collector being connected to the base of the third transistor, a ninth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to a base common connection node of the sixth, seventh and eighth transistors, the base being connected to the collector of the sixth transistor, a tenth transistor of the first polarity which has a base, an emitter and a collector, the emitter being connected to the collector of the ninth transistor, the base being connected to the collector of the second transistor, the collector of the tenth transistor being connected to the second voltage node, and an eleventh transistor of the second polarity which has a base, an emitter and a collector, the base and the collector being connected to the base of the third transistor, the emitter being connected to the emitter of the tenth transistor.
Additional object and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a circuit diagram of a conventional synchronous detection circuit;
FIG. 2 is a circuit diagram of the synchronous detection circuit according to a first embodiment of the present invention;
FIG. 3 is a circuit diagram of the synchronous detection circuit according to a second embodiment of the present invention;
FIG. 4 is a circuit diagram of the synchronous detection circuit according to a second embodiment of the present invention;
FIG. 5 is a circuit diagram of the synchronous detection circuit according to a fourth embodiment of the present invention; and
FIG. 6 is a circuit diagram of the synchronous detection circuit according to a fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described by reference to the drawings.
FIG. 2 is a circuit diagram of the semiconductor integrated circuit according to a first embodiment of the present invention; as the semiconductor integrated circuit, a synchronous detection circuit is exemplarily shown as in the case of the conventional semiconductor integrated circuit. In the description to follow, the constitutent portions which correspond to those in the conventional circuit shown in FIG. 1 are referenced by the same reference numerals.
Supplied to the base of an NPN transistor Q1 is an input signal VIN superimposed on a DC bias voltage VB. In the case of the conventional circuit shown in FIG. 1, the collector of this transistor Q1 is connected to the voltage node 11 to which the DC bias voltage VA is supplied, but in this embodiment, the collector of the transistor Q1 is connected to a predetermined node in a collection circuit to be described later.
The emitters of each of two pairs of NPN transistors Q2, Q3 and Q4, Q5 are connected commonly to each other, and, to the bases of the transistors Q2 and Q5, a switch control signal SW1 is supplied, while to the bases of the transistors Q3, Q4, a switch control signal SW2 is supplied. The collectors of the transistors Q2, Q4 are commonly connected to each other, and the collectors of the transistors Q3, Q5 are connected commonly to each other. Further, from a common connection node of the collectors of the transistors Q3, Q5, a detection output signal OUT is derived.
Used as a load to the transistors Q2, Q3, Q4 and Q5 is a current mirror circuit 10 which is comprised of PNP transistors Q6, Q7, Q8 and Q9, an NPN transistor Q10 and resistors R1, R2 and R3.
In the current mirror circuit 10, the emitter of the transistor Q6 is connected through the resistor R1 to the voltage node 11 to which a positive DC bias voltage VA is supplied. The collector of the transistor Q6 is connected to a current input terminal 12. Connected to this current input terminal 12 is the common collector of the transistors Q2, Q4. The emitter of the transistor Q7 is connected to the voltage node 11 through the resistor R2. The base of the transistor Q7 is connected commonly to the base of the transistor Q6, while the collector thereof is connected to a current output terminal 13. Connected to this current output terminal 13 is the common collector of the transistors Q3, Q5. The emitter of the transistor Q9 is connected to the voltage node 11 through the resistor R3. The base and collector of the transistor Q9 are connected to the common base of the transistors Q6, Q7.
The transistor Q9 and the resistor R3 are provided for preventing the current mirror circuit from oscillating.
In the case of the synchronous detection circuit according to this embodiment, a new correction circuit 30 is provided in place of the conventional correction circuit 20. This correction circuit 30 comprises PNP transistors Q31, Q32, Q33 and Q34, an NPN transistor Q35, and resistors R11, R12.
This correction circuit 30 corrects the base current of the transistor Q8 in the current mirror 10 and, at the same time, corrects the unbalanced state of the collector currents, based on the early effect, of the transistors Q6 and Q7
The PNP transistors Q31 and Q32 correspond to the transistors Q6 and Q7 in the current mirror circuit 10; and the bases of the transistors Q31 and Q32 are connected commonly to each other as in the case of the transistors Q6, Q7. Further, the resistors R11 and R12 correspond to the resistors R1, R2 in the current mirror circuit 10, and, through the resistors R11, R12, the transistor Q31, Q32 are connected to the voltage node 11 to which the DC bias voltage VA is supplied.
The emitter of the transistor Q33 is connected to the common base of the transistors Q31, Q32, while the base thereof is connected to the collector of the transistor Q31. Further, the emitter of the transistor Q34 is connected to the collector of the transistor Q33, while the base thereof is connected the collector of the transistor Q7 in the current mirror circuit 10, while the collector thereof is connected to the voltage node 14 placed at the earth voltage.
The collector and base of the transistor Q35 are connected to the collector of the transistor Q32 and also to a node N2 to which the base of the transistor Q10 in the current mirror circuit 10. The emitter of the transistor Q35 is connected to the emitter of the transistor Q34. The collector of the transistor Q34 is connected to the node 14.
Further, in the circuit according to this embodiment, in order to apply a constant voltage to the above-mentioned node N1, there is provided an NPN type transistor Q22. That is, the collector of the transistor Q22 is connected to the collector of the above-mentioned transistor Q1 and also to the collector of the transistor Q31, the emitter thereof is connected to the node N1, and the base thereof is supplied with a DC bias voltage VB.
The current ratio of the constant-current sources I1, I2, I3 and I4 are set to 1:2:2:1.
In this synchronous detection circuit, the transistors Q31 to Q35 and the resistors R11 and R12 are provided in the correction circuit 30 to thereby constitute within the correction circuit 30 a current mirror equal to the current mirror comprising the transistors Q6, Q7, Q10, Q8 and the resistors R1, R2 in the current mirror circuit 10, and further, the transistor Q35 is provided in such a manner that the base-emitter current path thereof is inserted between the emitter of the transistor Q34 and the base of the transistor Q10 in the current mirror circuit 10.
Further, in order to generate a constant voltage to be supplied to the node N1, the transistor Q22 corresponding to the transistor Q1 is added.
Further, in the current mirror circuit 10, the resistors R1 to R3 can be omitted, but in case they are omitted, the resistors R11 and R12 in the correction circuit 30 can be omitted.
As for the circuit shown in FIG. 2, in the current mirror circuit 10, the base current of the transistor QS flows into the collector of the transistor Q6 from the common base of the transistors Q6, Q7 through the collector-emitter current path of the transistor Q10 and through the emitter-base current path of the transistor Q8.
On the other hand, in the correction circuit 30, the base current of the transistor Q34 flows into the collector of the transistor Q7 from the common base of the transistors Q31, Q32 through the emitter-collector current path of the transistor Q33 and through the emitter-base current path of the transistor Q34.
Due to this, various conditions such as the element sizes of the transistors Q6 and Q31, the transistors Q7 and Q32, the transistors Q10 and Q35, and the transistors Q8 and the Q34, and the resistance values of the resistors R1 and R11, and the resistors R2 and R12 are made equal to each other, whereby the base current of the transistor Q8 can be set to approximately the same value of the base current of the transistor Q34.
Here, it is to be noted that, in case dispersions are caused among the elements when manufactured, the dispersions of the elements which are equal in respect of the various conditions become equal to one another, so that the values of the two base currents vary equally in accordance with the dispersions of the elements. Further, in case the ambient temperature is taken into consideration, it is pointed out that, since the circuit arrangement of the portion of the correction circuit 30 in which the base current of the transistor Q34 is produced is approximately equal to that in the current mirror circuit 10, the variations of the two base currents due to the variation in ambient temperature becomes equal to each other. As a result, the input/output current ratio of the current mirror circuit can be maintained constant without being influenced by the dispersions of the elements and the variation in emboldened temperature.
On the other hand, the voltage at a node N3 (the current input terminal 12 of the current mirror circuit 10) which is a common collector node of the transistors Q2, Q4 assumes the value determined in such a manner that the voltage at the node (the current output terminal 13 of the current mirror circuit 10) at which the detection output signal OUT is derived is raised by a value corresponding to the respective base-emitter voltages VBE of the transistors Q34, Q35, and the resulting voltage value is lowered by a value corresponding to the respective base-emitter voltages VBE of the transistors Q10, Q8. Here, generally it can safely be considered that the respective VBE of a PNP transistor and that of an NPN transistor are equal to each other, so that the voltage at the node N3 turns out to be equal to the voltage at the node at which the detection output signal OUT is derived. As a result, the emitter-collector voltages VCE of the transistors Q6 and Q7 can be equalized to each other; and thus, the problem that, by the influence of the early effect caused by the fact that the values of the respective emitter-collector voltages VCE differ from each other, the collector currents of the transistor Q6 and Q7 become unbalanced can be overcome.
Further, the voltage at the node N1 becomes a constant voltage having the value lower by the base-emitter voltage of the transistor Q22 than the DC bias voltage VB.
FIG. 3 shows the constitutional arrangement of the semiconductor integrated circuit according to a second embodiment of the present invention. In this circuit shown in FIG. 3, the constitutent portions which correspond to those of the circuit according to the first embodiment shown in FIG. 2 are referenced by the same reference symbols.
The synchronous detection circuit according to this second embodiment differs from the synchronous detection circuit shown in FIG. 2 in that the transistor Q10 in the current mirror 10 is omitted, that the emitter of the base current correction transistor QB is directly connected to the common base of the transistors Q6 and Q7, and that, in place of the correction circuit 30 shown in FIG. 2, a different correction circuit 40 is provided.
The correction circuit 40 differs form the correction circuit 30 shown in FIG. 2 in that the transistor Q35 is omitted in association with the fact that the transistor Q10 in the current mirror circuit 10 is omitted, and that a PNP transistor Q36 and a resistor R13 are newly added. Due to the omission of the transistor Q35, the collector of the transistor Q32 is connected to the emitter of the transistor Q34.
Further, the emitter of the newly added transistor Q36 is connected through the resistor R13 to the voltage node 11 to which the DC bias voltage VA is supplied. Further, the base of this transistor Q36 is connected to the base common connection node of the transistors Q31, Q32, and the collector thereof is connected to the voltage node 14 to which the earth voltage is supplied.
Further, in the case of this second embodiment, the resistors R1 to R3 may be omitted in the current mirror circuit 10, but, in case the resistors are omitted, the resistors R11 to R13 can be likewise omitted on the side of the correction circuit 40.
With such a constitutional arrangement, in the current mirror circuit 10, the base current of the transistor Q8 flows into the collector of the transistor Q6 from the common base of the transistors Q6 and Q7 through the emitter-base current path of the transistor Q8.
On the other hand, in the correction circuit 40, the base current of the transistor Q34 flows into the collector of the transistor Q7 from the common base of the transistors Q31, Q32 and Q36 through the emitter-base current path of the transistor Q33 and the emitter-base current path of the transistor Q34.
Here, it is to be noted that the base current of the transistor Q8 in the current mirror circuit 10 turns out to be 1/hfe of the total sum of the base current of the transistor Q6, the base current and the collector current of the transistor Q9, and the base current of the transistor Q7, that is, 1/hfe of the total sum of the base currents of three transistors and the collector current of one transistor; and thus, the base current of the transistor Q8 can be represented as (Ic+3Ib)/hfe wherein Ib stands for a base current, and Ic stands for a collector current.
On the other hand, in the correction circuit 40, the collector current of the transistor Q33 becomes 3Ib-α which is slightly smaller than the total sum of the base currents of the three transistors Q31, Q32 and Q36. To the collector of the transistor Q34, the collector current of the transistor Q33 and the collector current of the transistor Q32 join together, so that, if it is assumed that Ic stands for the collector current of the transistor Q32, then the collector current of the transistor Q34 is represented as (Ic+3Ib-α), and the base current of the transistor Q34 is represented as (Ic+3Ib-α)/hfe. Here, the α/hfe is sufficiently small as compared with (Ic+3Ib-α)/hfe, so that the base current of the transistor Q8 and the base current of the transistor Q34 can safely be regarded as approximately equal to each other.
Here, it is to be noted that, in case dispersions are caused among the elements when manufactured, the dispersions of the elements which are equal in respect of the various conditions become equal, so that the values of the two base currents vary equally in accordance with the dispersions of the elements. Further, in case the ambient temperature is taken into consideration, it is pointed out that the circuit arrangement of the portion of the correction circuit 40 in which the base current of the transistor Q34 is generated is approximately equal to that of the current mirror circuit 10, so that the variations of the two base currents due to the variation in ambient temperature also become equal.
As a result, in the case of the embodiment shown in FIG. 3, it is also possible to maintain the input/output current ratio of the current mirror circuit constant without being affected by the dispersions of the elements and the variation in the ambient temperature.
Next, a third embodiment of the present invention will be described, referring to FIG. 4.
The synchronous detection circuit according to this embodiment differs from the synchronous detection circuit shown in FIG. 3 in that, in place of the correction circuit 40 shown in FIG. 3, a different correction circuit 50 is provided. The correction circuit 50 differs from the correction circuit 40 shown in FIG. 3 in that an NPN transistor Q37 and a constant-current source I5 are newly added.
The collector of the newly added transistor Q37 is connected to the voltage node 11 to which the DC bias voltage VA is supplied, and the base thereof is connected to the collector of the transistor Q32. Further, the emitter of the transistor Q37 is connected through the constant-current source I5 to the voltage node 14 to which the earth voltage is applied.
As shown, to the collector of the transistor Q31 in the correction circuit 50, the base currents of the transistors Q11 to Q14 and the collector currents of the transistors Q11 and Q14 flow through the transistor Q1 or Q22. That is, the collector current of the transistor Q31 is increased by an amount corresponding to the currents flowing through these transistors Q11 to Q14. In response to this, the collector current of the transistor Q32 is also increased, as a result of which a discrepancy is caused between the base current of the transistor Q8 in the current mirror circuit 10 and the base current of the transistor Q34 in the correction circuit in some cases.
In the correction circuit 50 according to this embodiment, the increased amount of the collector current of the transistor Q32 due to the currents flowing through the transistors Q11 to Q14 can be made to flow as the base current to the transistor Q37, so that the discrepancy between the base current of the transistor Q8 in the current mirror circuit 10 and the base current of the transistor Q34 in the correction circuit 50 can be sufficiently reduced, whereby the input/output current ratio in the current mirror circuit 10 can be maintained constant.
The constant-current source I5 should be formed by the use of transistors having uniform characteristics as well as the above-mentioned constant-current sources I1 to I4.
Next, a fourth embodiment of the present invention will be described by reference to FIG. 5.
In the synchronous detection circuit according to this embodiment, in place of the correction circuit 30 according to the first embodiment shown in FIG,. 2, a different correction circuit 60 is provided.
The correction circuit 60 differs from the correction circuit 30 shown in FIG. 2 in that the correction circuit 60 is constituted in such a manner that the transistor Q36 and the resistor R13 in the correction circuit 40 shown in FIG. 3 are added into the correction circuit 30 shown in FIG. 2.
Therefore, according to this fourth embodiment, the correction of the base current component of the transistor Q8 can be made, by the correction circuit 60, in association with the collector current and the base current of the oscillation preventing transistor Q9 in the current mirror circuit 10 as in the case of the embodiment shown in FIG. 3; and thus, the current correction can be effected at a higher accuracy.
Next, a fifth embodiment of the present invention will be described by reference to FIG. 6.
In the synchronous detection circuit according to this embodiment, in place of the correction circuit 60 according to the fourth embodiment shown in FIG. 5, a different correction circuit 70 is provided.
The correction circuit 70 differs from the correction circuit 60 shown in FIG. 5 in that, into the correction circuit 60 shown in FIG. 5, the transistor Q37 and constant-current source I5 in the correction circuit 50 shown in FIG. 4 are added.
Therefore, according to this embodiment, there can be obtained the effect that, on the basis of the currents flowing through the transistors Q11 to Q14, the discrepancy caused between the base current of the transistor Q8 in the current mirror circuit 10 and the base current of the transistor Q34 in the correction circuit 70 can be sufficiently reduced, whereby the input/output current ratio in the current mirror circuit 10 can be made constant.
It is a matter of course that the present invention is not limited only to the above-described embodiments but can be variously modified. For instance, in the respective embodiments mentioned above, the present invention is applied to synchronous detection circuits, but the current source circuit according to the present invention can be easily applied in circuits directed to any other use.
As described above, according to the present invention, there can be provided a current source circuit constituted in such a manner that the input/output current ratio of a current mirror circuit can be maintained constant without being affected by the dispersions of the elements and the variation in ambient temperature.
Further, according to the present invention, the occurrence of an unbalanced state of the collector currents by the influence of the early effect based on the difference between the emitter-collector voltages of the transistors constituting the current mirror circuit can also be prevented.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalent.
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A current source circuit has a current mirror circuit and a correct ion circuit. The current mirror circuit includes first to fourth transistors. The bases of the first and second transistors are commonly connected to each other. A collector of the third transistor is connected to a common base of the first and second transistors. An emitter of the third transistor is connected to an emitter of the fourth transistor. A base of the fourth transistor is connected to the collector of the first transistor. The correction circuit includes fifth to eighth transistors. The base of the fifth and sixth transistors are commonly connected to each other. An emitter of the seventh transistor is connected to the common base of the fifth and sixth transistors. A collector of the seventh transistor is connected to an emitter of the eighth transistor. A base of the eighth transistor is connected to the collector of the second transistor.
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BACKGROUND OF THE INVENTION
The present invention relates to a device for providing a moisture impervient barrier and a method for making the same.
Many ponds, lagoons and basement structures require a waterproof barrier on the floor and sides thereof. Examples of such applications are waste lagoons, cooling ponds for nuclear plants, and other situations where moisture impervient barriers are necessary at the bottom of a pond or lagoon. Also such barriers are desirable on the floor and walls of some basement structures.
One material which has been found useful for providing such waterproof barriers is bentonite. Bentonite is a clay material which is found in nature and which has the characteristic which enables it to expand upon being exposed to water. When the bentonite expands, it is capable of forming a waterproof barrier. Bentonite is a natural material which is mined and which has the property of being capable of absorbing a great deal of water so as to swell in response to this absorption.
One desirable way to use this bentonite material is to package it in sheets or rolls which can be placed on the bottom of the pond or lagoon so as to form a waterproof barrier thereon. One prior method for providing such a packaged bentonite sheet material utilized the following process:
(a) Using a base polyester sheet material having the ability to permit gases to escape therethrough in a laterial direction.
(b) Applying an adhesive to the upper surface of this sheet material, the adhesive being formed from a starch-like glue.
(c) Applying approximately one-fourth inch of bentonite on top of the adhesive.
(d) Spraying a second coat of adhesive over the top of the bentonite.
(e) Placing a scrim or fine mesh material on top of the adhesive.
(f) Press rolling the above combination into an elongated flat sheet material.
(g) Baking the sheet material in a long oven at approximately 300° F. so as to bake all the moisture out of the sheet material and the bentonite.
The above process was cumbersome, expensive and timeconsuming. The use of adhesive and the baking process contributed substantially to these disadvantages.
Therefore, a primary object of the present invention is the provision of an improved device for providing moisture impervient barriers and the method for using the same.
A further object of the. present invention is the provision of a new moisture impervient material which does not require baking or adhesive as in prior art devices.
A further object of the present invention is the provision of a new moisture impervient material which is easily manufactured and mass produced.
A further object of the present invention is the provision of a moisture impervient material which prevents the seepage of water and the leaching of contaminants from ponds, reservoirs. dams, municipal and industrial waste lagoons, burial sites and other applications
A further object of the present invention is the provision of a moisture impervient barrier which greatly simplifies the manufacturing process.
A further object of the present invention is the provision of a moisture impervient barrier which can be manufactured in varying thicknesses for different applications.
A further object of the present invention is the provision of a moisture impervient barrier, which is economical to manufacture, durable in use and efficient in operation.
SUMMARY OF THE INVENTION
The present invention is an improvement over the prior processes for making packaged bentonite sheet materials. The invention involves the use of the following steps:
(a) Using a flat polyester sheet material, preferably a material sold under the trademark "Trevira" by American Hoechst Corporation, Post Office Box 5058, New York. N.Y. 10087. The material is a synthetic non-woven fabric which is a porous, flexible polypropylene material. The sheet material is capable of dissipating gas in a lateral direction so as to permit gas which gathers adjacent the sheet material to pass laterally outwardly through the sheet material.
(b) Applying approximately one-fourth inch of bentonite over the top of the base material.
(c) Applying plain kraft paper or other biodegradable material over, the top of the bentonite. This material must be capable of degrading after hydration.
(d) Stitching the sheet material to the base material with the bentonite being positioned between the two sheets of material. In the preferred form of the invention, the stitches extend in crossing diagonal lines with respect to the longitudinal axis of the sheet material so as to form diamond shaped quilted compartments between the upper sheet material and the base sheet material. The quilted compartments contain bentonite therein. The quilted arrangement prevents the bentonite from shifting during the rolling of the quilted material and during transportation. In another form of the invention, the kraft paper is corrugated so as to form elongated corrugated compartments for containing the bentonite material.
When the above material is placed within a water environment, such as at the bottom of a pond or lagoon, the bentonite expands and breaks the kraft paper layer at the top of the barrier. The bentonite continues expanding so as to cover the stitch holes formed by the stitching, and thereby forms a water impervient material.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
FIG. 1 is a perspective view of the water barrier of the present invention.
FIG. 2 is a sectional view showing the water barrier placed at the bottom of a pond or lagoon.
FIG. 3 is an enlarged sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a sectional view of the barrier during the manufacturing process.
FIG. 5 is a schematic view of the manufacturing process for making the barrier.
FIG. 6 is a perspective view of a modified form of the present invention.
FIG. 7 is a sectional view of the device shown in FIG. 6, showing the manner in which two such devices can be joined in edge relation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the numeral 10 generally designates the moisture impervient barrier of the present invention. Barrier 10 comprises a base sheet material 12, a top sheet material 14, and a bentonite filling material 16.
Base sheet material 12 is preferably formed from a polypropylene material which is porous so as to permit gases to move horizontally within the sheet material. The preferred material is a material sold by American Hoechst Corporation, Post Office Box 5-058, GPO, New York, N.Y. 10087, under the trademark "Trevira" and designated by the product number S11150, and S11200. The material is a non-woven material not knitted or stitched. It is porous to gas and flexible so as to conform to the shape of the bottom of the lagoon or pond on which it is used.
Top sheet member 14 is preferably formed from kraft paper or from some other biodegradable material which will decompose within the water after the barrier is in place. Furthermore, the material must be capable of tearing in response to the expansion of the bentonite within the barrier 10. Preferably the material should be pervious to water so as to permit hydration of the bentonite material. Top sheet member 14 is formed into a plurality of corrugations having concave downward portions 18 and concave upward portions 20. The concave upward portions 20 are adjacent the upper surface of base sheet member 12 and are attached thereto by means of elongated stitch lines 22, the individual stitches of which extend downwardly through both the top sheet member 14 and the base sheet member 20. The thread used for stitch lines 22 is preferably a biodegradable material such as cotton or other material which will decompose with time. Stitch lines 22 extend parallel to one another in a longitudinal direction.
The bentonite is a naturally found material which is clay-like. It is preferably a sodium based Wyoming bentonite ground into granules so as to be easily placed within the spaces below the concave downward portions 18 of top sheet member 14. The bentonite includes the mineral montmorillonite, and the montmorillonite content should be approximately 90%. The bentonite material should be dry with a minimum of 6% moisture, and a maximum of 12% moisture.
FIGS. 2 and 3 show the use of the barrier as a floor for a lagoon or pond 24. When the barrier 10 is placed at the bottom of the pond and is exposed to water, the water passes through the top layer of kraft paper 14 and is absorbed into the bentonite material. The bentonite has the capacity to expand and swell in response to absorbing the water, and it swells to a substantially uniform flat layer of material as shown in FIGS. 2 and 3. This expansion causes the kraft paper 14 to tear and break in response to the expansion so that the bentonite can form a complete layer over the bottom sheet member 12. With time, the paper 14 will decompose, leaving only the bentonite exposed to the water. The bentonite swells and covers the stitch holes designated by the numeral 26 within the bottom layer 12, so as to prevent water from passing therethrough. The stitches 22 are also covered by the bentonite so as to prevent water from escaping by siphoning or wicking through the stitches 22. As time passes, the stitches decompose in the same fashion that the paper 14 decomposes.
Base layer 26, because of its permeability to gases, permits gases to escape laterally when gases are formed beneath the base layer 26 by deomposition. decaying and the like. These gases pass laterally through the barrier 26 and outwardly through the outer edges of the barrier 26. This prevents bubbles or irregular shapes to be forced upwardly from the bottom of the barrier, in response to decaying gases formed beneath the barrier 10.
Referring to FIGS. 4 and 5, the sheet material of the present invention is made in the following manner. A roll 28 of base sheet material 12 is passed horizontally over a conveyor belt 30. An additional roll 32 of kraft paper 14 also passes over conveyor 30. A guide roller 34 provides horizontal support for sheet 12, and a plurality of press wheels 36, 38, 40 hold sheet member 14 in close approximate relationship to the upper surface of sheet member 12.
Referring to FIG. 5, press wheels 38 are spaced apart so as to form the concave upward portions 20 of upper sheet member 14. Press wheels 40 are of similar construction.
Between press wheels 38, 40 are a plurality of stitching needles 42 which provide the stitch lines 22 so as to secure the concave upward portions 20 to the base material 12.
Press wheels 36 are spaced apart in a fashion similar to the press wheels. 38, 40 and a plurality of feed spouts 44 are positioned so as to feed bentonite beneath top sheet 14 in the elongated corrugated compartments formed by downwardly facing concave portions 18.
Referring to FIGS. 6 and 7, a modified form of the invention is shown and is designated generally by the numeral 50. The assembly 50 comprises a polyester base sheet material 52 similar to sheet member 26 shown in FIG. 1. Positioned upon sheet member 52 is a layer of bentonite material designated by the numeral 54. Above bentonite 54 is a layer of kraft paper or other biodegradable material 56.
As can be seen in FIG. 6, sheet member 52 has one lateral edge 58 which protrudes beyond the bentonite 54 and kraft paper 56 and which has exposed on its upper surface a strip fastener which is sold under the registered trademark "Velcro" and which is designated by the numeral 60. A matching strip material 62 is attached along the opposite edge of sheet member 60 on the lower surface thereof. Strips 60, 62 are adapted to mate with one another and frictionally engage one another in the fashion shown in FIG. 7 so that two strips of the device 50 may be joined together in the fashion shown in FIG. 7.
Kraft paper 56 is joined to sheet member 52 by means of a quilted stitching designated generally by the numeral 64. Referring to FIG. 6, stitching 64 extends in diagonal lines which form diamond-shaped quilted compartments 66. As can be seen in FIG. 7, stitching 64 does not depress the kraft paper layer 56, but instead spans the distance between layer 56 and layer 52 so as to maintain a substantially uniform thickness for the bentonite 54. The preferred thickness for the bentonite 54 is approximately one-fourth of an inch, but this may be increased or decreased without detracting from the invention. Lateral stitching lines 68, 70 extend around the perimeter of sheet member 56 so as to provide securement adjacent the edges thereof.
The particular machinery for providing the quilted stitching of device 50 is well known in the art. Such machines have long been used for providing quilted stitching to other material. All that needs be added to these present machines is the provision of a bentonite hopper for adding the layer of bentonite between the paper or biodegradable sheet 56 and the base sheet 52.
The quilted device 50 may be used in the same manner as shown in FIG. 2 for the corrugated device 14. However, a preferred method for using the quilted material or the corrugated material is to place approximately six inches of aggregate material on top of the quilted or corrugated layer prior to hydrating the material. This six inch aggregate layer provides a solid anchor for the corregated material and prevents any movement thereof during the hydration process.
It should be noted that no baking or adhesives are required in order to assemble the device, since the stitching holds the barrier together. The barrier is rolled up in a roll 46 and is ready for transporting to the site where the barrier will be used. The thickness of the barrier may be varied depending upon the particular application needed. Adjustment of the thickness is quite easily accomplished merely by changing the height of the quilted components or corrugations formed by upper sheet member 14. The product can be made on a continuous manufacturing basis and is not limited by the need for baking or drying out the bentonite in the middle of the process as was the case with prior processes.
Thus, it can be seen that the device accomplishes at least all of its stated objectives.
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A device for providing a moisture impervient barrier, comprises a flexible base sheet member having a layer of bentonite resting on its upper surface. A top sheet member is positioned over the bentonite and is secured to the base member by stitches extending therebetween. The stitches form either a quilting pattern or in the alternative, they can form elongated corrugated compartments filled with bentonite which will swell and break the top sheet member when exposed to water.
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BACKGROUND OF THE INVENTION
The present invention relates to a coating roller device which is favorable for the application of a coating material of high viscosity, in which the coating material is fed under pressure.
Conventional coating roller devices in which coating materials are fed under pressure are arranged to have coating rollers rotatably supported on supplying pipes of small diameter for the coating materials, which pipes serve also as shafts for pivotally connecting the roller bodies, whereby the coating materials supplied through the supplying pipes are fed to the insides of the cylindrical cores of the roller bodies, namely, to the annular spacing between the supplying pipes for the coating materials and the cylindrical cores of the roller bodies, which cores are provided with the outflow holes for the coating materials, from delivery holes made through the circumferential walls of the supplying pipes for the coating materials, and the coating materials within this annular spacing flow to the outside circumferential surfaces of the roller bodies from the outflow holes of the cylindrical cores for the coating materials.
In such conventional coating roller devices in which coating materials are fed under pressure, a coating material of high viscosity is forced out of the outflow holes of the cylindrical cores of the roller bodies by means of the supplying pressure for the coating material after the annular spacing inside the cylinderical cores have been filled with the coating material. Therefore, it is necessary to sufficiently increase the supplying pressure for the coating material. Also, since the annular spacing of great volume remains filled with the coating material, there is a risk that a great amount of coating material stays and hardens within the roller body particularly when the coating material is of a type which sets as a result of the chemical reaction of, for example, two constituent liquids, or any other similar type. The post-treatment of the coating material which sets and stays in the roller body needs a great amount of labor and time. These are disadvantages of the conventional coating roller devices.
SUMMARY OF THE INVENTION
The present invention provides a coating roller device in which a coating material is fed under pressure to remove the foregoing disadvantages of the conventional coating roller devices.
The characteristic of the present invention is that a coating roller device which rotatably supports on a supporting shaft a coating roller body provided through its circumferential wall with delivery holes for a coating material, and which adapted to feed a coating material into the roller body, incorporates in the roller body a scraper means for the coating material having, over the substantially whole length of the roller body, a scraping element fixed on the supporting shaft so as to approximate the inner circumferential surface of the roller body, whereby the roller body is rotated relatively to the scraper means for the coating material.
According to the coating roller device of the present invention, even if a coating material fed into the roller body is so high in its viscosity that gravity does not allow the coating material to flow naturally out of the roller body, and moreover, even if the coating material is so small in its feeding amount that it can not fill the inside of the roller body, namely, the smallness in the feeding amount of the coating material is such that it only adheres to the inner circumferential surface of the roller body, the coating material which has adhered to the inner circumferential surface of the roller body is allowed to be forcibly scraped off to the outer circumferential surface of the roller body from the delivery holes of the roller body by means of the scraper means for the coating material which automatically has relative rotation to and within the roller body as a result of the rotation of the roller body, and subsequently, for example, a coating brush or the like on the outer circumferential surface of the roller body is soaked in the coating material which is scraped off to the outer circumferential surface of the roller body, thereby achieving the satisfactory coating operation of the coating roller device.
From the foregoing description, it will easily be understood that the coating roller device of the present invention prevents any stay of a great amount of coating material within the roller body, and achieves the complete exhaustion of the coating material fed into the roller body when the coating works are finished even if the inside of the roller body is filled with the coating material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional elevational view showing a preferred embodiment of the present invention.
FIG. 2 is a cross sectional side view showing an operating condition of the coating roller device of the foregoing preferred embodiment of the present invention.
FIGS. 3 to 5 are cross sectional views respectively showing the principal portions of modifications of the scraper means for a coating material.
FIG. 6 is a longitudinal sectional elevational view showing a second preferred embodiment of the present invention.
FIG. 7 is a perspective view of the scraper means of the second embodiment.
FIG. 8 is a longitudinal sectional enlarged elevational view showing the principal portion of the coating roller device of the second embodiment.
FIG. 9 is a longitudinal sectional side view showing the principal portion of the coating roller device in operation.
FIG. 10 is a longitudinal sectional view showing the third embodiment of the present invention.
FIG. 11 is a perspective view of the scraper means of the third embodiment.
FIG. 12 is a longitudinal sectional englarged elevational view of the principal portion of the third embodiment.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
In FIGS. 1 and 2, 1 is a roller body, and 2 is a supporting shaft. 3 is a scraper means for a coating material. The roller body 1 comprises a cylindrical body 5 provided with a great number of delivery holes 4 for a coating material through its circumferential wall, with caps 6a and 6b, and also, with a cylindrical brush 7 fitted to the cylindrical body 5. The cylindrical brush 7 is made of a piled texture or the like, and is of a known type. This brush is shown by a broken line. The supporting shaft 2 is formed by means of a supplying pipe for a coating material. This supporting shaft is fitted with a grip and with a feeding hose for a coating material through a cock in its one end (not shown), and has the scraper means 3 connected to its other end.
The scraper means 3 for a coating material is furnished with a flow passage 8 for a coating material which extends longitudinally therethrough near one longituidinal side of said scraper means, and is provided with a sectionally arc-shaped scraping element 3a for a coating material over its whole length in its other side. The passage 8 for the flow of a coating material has a bearing member 9 thread-coupled to its one open end. This bearing member serves also as a connector for the supporing shaft, and one end of the roller body 1 is rotatably supported on this bearing member 9 through the cap 6a. The passage 8 for the flow of a coating material also has a bearing member 10 thread-coupled to its other open end. This bearing member 10 functions also as a blank cap of the cylindrical body 5, and the other end of the roller body 1 is rotatably carried on this bearing member 10 through the cap 6b.
The outside end portion of the bearing member 9 is thread-coupled to the end portion of the supporting shaft 2, and there is provided a passage 11 for the flow of a coating material which intercommunicatively connects the inside passage of the supporting shaft 2 and the passage 8 of the scraper means 3 for a coating material. Moreover, the scraper means 3 is provided with delivery holes 12 for a coating material at suitable intervals in the direction of the length of the passage 8 for the flow of a coating material, and the scraping element 3a approximates the diameter of the inner circumferential surface 5a of the cylindrical body 5 in the roller body.
In the coating roller device arranged as described in the foregoing, if a coating material is fed under predetermined pressure into the the supporting shaft 2 which serves also as a supply pipe for a coating material, the coating material passes through the passage 11 inside the bearing member 9, through the passage 8 within the scraper means 3, and flows into the spacing 14 inside the roller body 1 from the delivery holes 12. In this condition, if the roller body 1 is rotated, with the cylindrical brush 7 forced against a surface 13, the roller body 1 has relative rotation to the scraper means 3 for the coating material. For this reason, the coating material which has adhered to the inner circumferential surface 5a of the cylindrical body of the roller body is scraped together at the front side portion of the scraping element 3a of the scraper means 3, namely, at the rear of the rotating direction of the roller body 1, as illustrated in FIG. 2, and the coating mateial thus scraped together is forced out by means of the scraping element 3a into the cylindrical brush 7 from the wedge-shaped portion between the arc-shaped end surface of the scraping element 3a and the inner circumferential surface 5a of the cylindrical body 5 through the coating-material delivery holes 4 of the cylindrical body 5. If the roller body 1 is reversely rotated, the foregoing "scrape-off" operation is carried out at the rear of the rotating direction of the roller body 1 on the opposite side of the scraping element 3a for the coating material.
The coating material is thus forced out into the cylindrical brush 7, and this allows the cylindrical brush to be soaked in the coating material. The coating material is then transferred onto the surface 13, thereby achieving the coating of the surface.
The scraper means 15 illustrated in FIG. 3 is furnished with scraping elements 15a and 15b at its both sides in the diametrical direction such that they approximate the inner circumferential surface 5a of the cylindrical body. Moreover, the scraper means 16 shown in an imaginary two-dot chain line is provided with three scraping elements 16a to 16c at regular intervals in the circumferential direction. From such embodiments of the scraping elements it will easily be understood that the scraping elements are not limited in number in the circumferential direction. Also, the delivery holes 12 for a coating material can be made between every two scraping elements. Moreover, as illustrated in the scraper means 17 or 18 of FIG. 4, it is desirable that the scraper means for a coating material is furnished with the minimum required thickness to achieve reduction in material cost and in weight.
The scraper means 19 shown in FIG. 5 is formed with through-holes 20a and 20b of the same diameter over its whole length so as to be adjacent to its both longitudinal sides, and is arranged to be symmetrical in its sectional configuration including the shape of the outside surfaces of the both longitudinal sides. In this scraper means 19 for a coating material, either one of the two holes 20a and 20b, for example, the hole 20a may be provided with a thread 21 in its both ends to couple the foregoing bearing members 9 and 10 therewith, and may have coating-material delivery holes 12 machined therein which are intercommunicatively connected to said hole, while on the other hand, the hole 20b may be closed in its both ends by means of blank caps as the case may be. With such an arrangement, the scraper means 19 can be applied to greater economization and higher workability. That is to say, the hole 20b which is not used as a passage of the flow of a coating material is useful for material saving and weight reduction, and besides, when the thread and the delivery holes 12 for a coating material are machined, there is no necessity to select a predetermined one of both longitudinal sides, thereby improving the workability.
Second Embodiment
In FIGS. 6 to 9, 31 is a scraper means for a coating material, and in this scraper means, a circular tubular body is formed with depression portions 33a and 33b on both diametrical sides of the outer circumferential surface thereof, and with circular tubular portions 32a and 32b left intact on both ends thereof, while at the same time, the circular tubular body is provided with a plurality of axially spaced distributing passages 35 which intercommunicatively connect the notched depression portions 33a and 33b with a central supply passge 34 for a coating material, and the central supply passage 34 is concentrically formed with tapped hole portions 36a and 36b in its both ends. 37 is a supporting shaft which serves also as a supply pipe for a coating material, and a holding member 38 for the scraper means is horizontally connected at right angles with one end of this supporting shaft 37. The other end of the supporting shaft is provided with a handle connecting portion 39 which functions also as a supply pipe. The holding member 38 of the scraper means is formed with a threaded shaft portion 40 in its end, and when this threaded shaft portion 40 is coupled with the tapped hole portion 36a of one end of the scraper means 31 for a coating material, the scraper means is supported in the form of a cantilever. With this scraper means 31 thus supported, the holding member 38 of the scraper means is provided with a passage 41 which intercommunicatively connects the central supply passage 34 of the scraper means 31 and the internal passage 37a of the supporting shaft 37 which serves also as a supply pipe for a coating material.
42 and 43 are supporting caps for the roller body, and are provided with core supporting portions 42a and 43a of slightly larger diameter than the circular tubular portions 32a and 32b on both ends of the scraper means 31, and moreover, these supporting caps are furnished with flange portions 42b and 43b which are greater in diameter than the core supporting portions. One cap 42 is rotatably supported between the threaded portion 40 of the holding member 38 of the scraper means and a cap positioning flange 44 such that the flange portion 42b is located away from the threaded portion 40 of the holding member, and the other cap 43 rotatably rests upon a cap carrying shaft 45 which is coaxially connected to the tapped hole portion 36b on the outside end of the scraper means 31 through a threaded shaft portion 45a. 45b is a flange for the prevention of cap detachment, and 45c is a grip portion for rotating the cap.
46 is a roller body, and is provided with a cylindrical core 48 which is furnished with a great number of delivery holes 47 for a coating material. This cylindrical core is arranged to be slightly smaller in its inside diameter than the diameters of the core supporting portions 42a and 43a of the roller-body supporting caps 42 and 43.
In assembly, with the cap carrying shaft 45 and the cap 43 respectively unassembled, the roller body 46 is attached to the scraper means 31 from its one end side, and the inside end portion of the core 48 is closely fitted and fixed to the core supporting portion 42a by pressing the core 48 axially until the core 48 comes into contact with the the flange portion 42b of the cap 42. Next, the core supporting portion 43a of the cap 43 is axially pressed until the flange portion 43b comes into contact with the outside end of the core 48 to closely attach and fix the core supporting portion to the outside end portion of the core 48, and the threaded shaft portion 45a of the cap carrying shaft 45 is thread-coupled with the tapped hole portion 36b of the scraper means 31 through the central aperture of the cap 43, whereby the scraper means 31 for a coating material has the cap carrying shaft 45 connected to its outside end, and the cap carrying shaft 45 allows the cap 43 to be rotatably supported.
In operation, a coating material is fed under pressure to the central supply passage 34 of the scraper means 31 through the supporting shaft 37 which serves also as a supply pipe for a coating material. This coating material is forced out into the notched depression portions 33a and 33b from the inside of the supply passage 34 through the distributing passages 35. Under this condition, the roller body 46 is pressed against the surface 49, and is reciprocatively transferred along the coating surface 49 by using the supporting shaft 37 to rotate the roller body 46 about the scraper means 31 so that the roller body rolls on the surface.
The coating material fed into the notched depression portions 33a and 33b of the scraper means 31 is forced owing to friction between the coating material and the rotating core 48 against a corner portion 50 located in the rotating direction of the roller body, and this coating material is passed through the core 48 into the roller body 46 from each delivery hole 47 which passes the corner portion 50. The coating material thus introduced into the roller body 46 is transferred onto the coating surface 49 in accordance with the rolling operation of the roller body, and as a result, a coating film is formed on the coating surface 49.
In the foregoing second embodiment of the present invention, the notched depression portions 33a and 33b formed on the scraper means 31 are two in number. However, a single or more than three depression portions may be provided. Also, the depression portions may be concave on their bottom surfaces although they have flat bottom surfaces on the foregoing embodiment.
In the coating roller device of the second embodiment, the circular tubular portions 32a and 32b on both ends of the scraper means for a coating material approximate the inner circumferential surface of the core 48 of the roller body, and this allows the suppresion of any outward transfer of the coating material to each cap side from the portions. Therefore, it will easily be understood that leakage of a coating material from between the caps and the core of the roller body, between the caps and the shaft portions rotatably supporting the caps, or any other similar portions can be completely prevented or minimized.
Third Embodiment
The third embodiment shown in FIGS. 10 to 12 is a modification of the foregoing second embodiment, and in this third embodiment, the same reference numerals as in the second embodiment are given to the identical portions of the coating roller device with those of the second embodiment to omit their description. The differences of the third embodiment from the second embodiment are that a tapped hole portion 36 is only formed on a single end of the supply passage 34 which extends through the middle portion of the scraper means 31 for a coating material, that the core supporting portion 42a of the inside end supporting cap 42 for the roller body is threaded, that the outside end supporting cap 43 for the roller body and the cap carrying shaft 45 are removed, and that the roller body 46 is closed in its single end portion by means of the blank cap 51.
In assembly, the roller body 46 is attached to the scraper means 31 from its open end side, and both ends of the core 48 are rotatably supported on the circular tubular portions 32a and 32b, while at the same time, the core supporting portion 42a is coupled and fixed to the inside end portion of the core 48 in the reverse form of a reverse self-tapping screw by screwing the core 48 axially until the core 48 comes into contact with the the flange portion 42b of the cap 42 as shown in FIG. 12.
The operating manner described in the second embodiment applies to the coating roller device of this third embodiment.
The central supply passage 34 provided for a coating material in the scraper means 31 may be closed in the blank cap 51 side end portion of the roller body 46. Moreover, a method for coupling the supporting cap 42 for the roller body with the core 48 of the roller body 46 is not confined on the foregoing embodiment. For example, an alternative method is that small screws can be screwed or pins can be driven from the outside of the core 48 to fix the core and the supporting cap 42.
According to the arrangement of the third embodiment, a roller body closed at one end is employed and the core of this roller body is rotatably supported at its both ends on the circular tubular portions located on both end portions of the scraper means. Moreover, the rotatable cap is arranged to approximate one end of the scraper means so that the roller body is detachable from the scraper means. As a result of these arrangements, the component parts are extremely reduced in number, and this allows inexpensive manufacturing of the coating roller device of the third embodiment. Also, the cap side circular tubular portion of the scraper means approximates the diameter of the inner circumferential surface of the core of the roller body, thereby preventing the outward transfer of the coating material in the direction of the cap from the scraper means. For this reason, leakage of the coating material is completely obviated or minimized between the cap and the core of the roller body, between the cap and the shaft portion rotatably supporting the cap, or at any other similar portions.
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A coating roller device which rotatably supports on a supporting shaft a tubular cylindrical coating roller body provided with delivery holes for a coating material through its circumferential wall, and which is adapted to feed a coating material to the roller body, incorporates within the roller body a scraper means extending substantially the whole length of the roller body, and having a scraping element fixed on the supporting shaft and approximating the inner circumferential surface of the roller body. The roller body is rotatable relatively to the scraper means. When the roller body is brought into contact with a surface and is moved therealong by using the supporting shaft, the roller body rotates relatively to the scraper means, whereby the coating material fed into the roller body is scraped off the inner surface thereof through the delivery holes in the circumferential wall of the roller body by the scraping element of the scraper means.
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BACKGROUND OF THE INVENTION
a. Field of the Invention
This invention relates to a feeding apparatus for crown caps, screw caps and the like, hereinafter referred to as "caps", which are made of magnetic substance. More particularly, a invention relates to the feeding apparatus for such caps of bottles and the like, in which the caps held disorderly in the hopper of the apparatus can be fed one by one in good order in a continuous manner to a cap receiving device of a cap placing apparatus such as a crowner or capper.
B. Description of the Prior Art
In the cap feeding apparatuses of the prior art, as the selecting means for the positioning of the caps in order to feed them with the proper sides out into a chute which is connected to a cap placing apparatus, there have been proposed several kinds of apparatuses in which, for example, disorderly arranged caps from the hopper are dropped on a rotating disk and said caps are separated by centrifugal force due to the difference of the friction to the disk surface between the caps in right positions and those in wrong positions, thereby the caps with a certain positioning are led to the chute. Further, in such conventional apparatus, the operator of the apparatus must usually remove the stagnated caps from the guide passage in order to prevent the accumulation of the caps at the guide passage which is connected to the cap placing apparatus. The conventional cap feeding apparatus produces loud noise. In addition to that, the hopper which holds the caps must be placed on the top portion of the apparatus and descending passages for caps must be generally employed. Therefore, the arrangement and installation of the apparatus are somewhat restricted. Further, the function of such feeding apparatus is not always sufficiently reliable in its operation. Still further, the work for removing the accumulated caps in the cap guide passage reduces the workability very much as well as it is troublesome for the operators.
SUMMARY OF THE INVENTION
In view of the above-mentioned disadvantages caused in the conventional apparatus, the principal object of the present invention is to provide an improved feeding apparatus for caps which are made of magnetic substance, in which the caps can be fed one by one continuously and constantly in good order to the cap receiving device of the cap placing apparatus, by the employment of a conveyor belt having magnetism.
A further object of the present invention is to provide an improved cap feeding apparatus in which the caps are received from the hopper placed in a lower position, and said caps are magnetically attracted by said magnetic conveyor belt and transferred effectively to a certain passage in the desired direction without producing any noises.
A still further object of the present invention is to provide an improved cap feeding apparatus in which a pair of conveyor belts are moved in parallel a small distance apart, and caps are attracted on the surfaces of said conveyor bels with their back sides out to perform the selective action of separating the differently arranged caps, and further either of such conveyor belts can be used as the transferring and feeding conveyor belt.
A still further object of the present invention is to provide an improved cap feeding apparatus in which a baffle is provided to release the overlapped caps on said conveyor belt, thereby the reliability of the performance of the above-mentioned selection mechanism by the pair of conveyor belts can be made sure to provide the correct operation of the feeding apparatus.
A still further object of the present invention is to provide an improved cap feeding apparatus in which the inlet portion of the guide passage which is positioned near the receiving device of the cap placing apparatus is provided with an intermittently swinging mechanism to sweep away the accumulated caps in said portion, thereby the caps can be moved smoothly and automatically without the assistance of the operator.
A still further object of the present invention is to provide an improved cap feeding apparatus in which a tapered cap guiding section being provided with an inclined guide fence and a swingable fence, is formed on the upstream portion of said guide passage, where the downstream half of said inclined guide fence is made movable and the top portion of said swingable fence is made of a spring-operated arc-shaped plate, thereby the prevention of the accumulation of the caps in the guiding section can be smoothly and effectively accomplished to provide reliable operation of the apparatus.
Pursuant to the above-mentioned objects, the present invention proposes a feeding apparatus for caps made of magnetic substance with comprises a first conveyor belt having magnetism to attract and transfer the caps from a hopper, a baffle to release overlapping of the caps on said conveyor belt, a second conveyor belt to select out the caps in wrong position, a guide passage to deliver the caps one by one to a cap placing apparatus, a set of an inclined guide fence and a swingable fence to define a guiding section, an outlet to discharge excess caps, and a swinging means to swing said swingable fence.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will be more fully understood by referring to the following detailed description presented solely for purpose of illustration and to the accompanying drawings in which:
FIG. 1 is a vertical schematic illustration of an embodiment of the cap feeding apparatus of the invention;
FIG. 2 is an enlarged side view of a baffle provided in the transferring passage of the apparatus as shown in FIG. 1;
FIG. 3 is an enlarged plan view of said baffle as shown in FIG. 2;
FIGS. 4 and 5 are a side view and a plan view, respectively, showing another embodiment of the baffle different from that shown in FIGS. 2 and 3;
FIG. 6 is a vertical schematic illustration of another embodiment of the cap feeding apparatus in which a cap arranging means is provided on the downstream side of the conveyor belt to guide properly the caps to the cap placing apparatus;
FIG. 7 is an enlarged plan view taken along the line VII--VII in FIG. 6; and
FIG. 8 is a sectional view taken along the line VIII--VIII in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to the drawings, especially to FIG. 1, the numeral 1 indicates a conveyor belt which is imparted with magnetism by, for example, a plurality of covered magnets, and is moved by a pair of pulleys 2 and 3 in the direction of the arrows. The lower end portion of said conveyor belt 1 is positioned close to an opening of a hopper 4 in which a large number of caps made of magnetic substance are contained in random order. When the hopper 4 is vibrated by a vibrator (not shown), the caps 5 in the hopper 4 contact with the conveyor belt 1 through the opening and are attracted by the magnetic force of the conveyor belt 1, thereby the caps are moved upwards on the surface of the conveyor belt 1. In this case, as the caps 5 are disorderly in the hopper 4, the caps are attracted on the conveyor belt 1 in no special order, so that some of the caps have their front sides out and other have their back sides out, and some of them overlap with each other as shown by the numeral 6. The numeral 7 is a baffle to release said overlapped caps 6 on the conveyor belt 1 which will be explained in detail in the following.
The conveyor belt 1 which attracts and carries the caps 8 of front side out and caps 9 of back side out, without these being overlapped caps due to the action of baffle 7, is then moved closely and in parallel with the second conveyor 10 which is also imparted with magnetism. Of course in this case, the distance between said first conveyor belt 1 and said second conveyor belt 10 must be somewhat larger than the height of each cap 8 or 9. By selecting the proper distance between the conveyor belts 1 and 10 and the proper intensities of the magnetism of the conveyor belts 1 and 10, the caps 8 which are fitted to the first conveyor belt 1 in front side out are attracted to the second conveyor 10 in the state of back side out as indicated by the numeral 11. Thus the caps 11 being attracted to the second conveyor belt 10 in back side out, are carried thereon by the rotations of the pulleys 13 and 14, and are returned again into the hopper 4 through the chute 15. The caps 9 which are attached in back side out on the first conveyor belt 1 are not transferred to the second conveyor belt 10 because the magnetic force of the first conveyor belt 1 attracts more strongly the caps 9 as compared with the magnetic force of the second conveyor belt 10. The caps remaining on the first conveyor belt which are now indicated by the numeral 12, are then carried as they are by the first conveyor belt 1 and fed to the cap placing apparatus or a capper (not shown) through the chute 16 or to the below-mentioned arranging means (in FIGS. 6 and 7).
The caps 11 which are carried on the second conveyor belt 10 can be fed also to said cap placing apparatus or another cap placing apparatus or capper in place of the above-mentioned returning to the hopper 4 through the chute 15. In such case, the selecting capacity of the feeding apparatus can be doubled. For example, in the former case, one cap placing apparatus is fed with the caps from two sources, therefore the apparatus must be controlled such that the caps are fed one by one by turns or when one source becomes free of caps, the other source can be used.
In order to impart magnetism to the first and the second conveyor belts 1 and 10, a large number of magnets are buried in the conveyor belts, or conventional magnetic belts on the market can be used. A similar effect can be obtained by providing magnetic plates close to the back side of said conveyor belts 1 and 10. But in this case, the pulleys 2 and 13 must be made of magnetic substance.
FIGS. 2 and 3 illustrate the details of the baffle 7, which comprises two plates made of elastic material such as rubber. The distance between the lowermost ends of said plates 7 and the surface of the conveyor belt 1 is larger than the height of each cap while it is smaller than twice the height of the cap. Said plates are connected integrally by a connecting rod 17 and are reciprocated in the directions of the arrows Y which are at a right angle to the direction of the movement of the conveyor belt 1, i.e. the arrow X, by means of an appropriate reciprocating mechanism (not shown). During the reciprocation of the baffle 7, if the conveyor belt 1 carries a cap 9 of back side out which is overlapped with other caps 60 as shown in FIG. 2, the caps 60 contact with at least one end portion of said two plates and are moved aside. Thereby the overlapped caps 60 are changed into the caps 8 as shown by the dash lines in FIG. 3. Thus as shown in FIG. 1, all overlappings of the caps on the conveyor belt 1 are released by the baffle 7 in the condition of the caps 8 in front side out or the caps 9 in back side out, and they are then moved to the position of the second conveyor belt 10.
FIGS. 4 and 5 show another baffle 70 which has a simpler construction as compared with the above-mentioned baffle 7. The baffle 70 comprises an elastic plate and the distance between the lowermost end of said plate and the surface of the conveyor belt 1 is the same as the aforementioned distance between the lowermost ends of the two baffle plates 7 and the surface of the conveyor belt 1. This baffle plate 70 is fixed at its position by a proper means (not shown), while if there are overlapped caps 9 and 60 on the conveyor belt 1 moving in the direction of the arrow X as shown in FIG. 4, the lowermost end of the baffle 70 hits against the cap 60, thereby the cap 60 is moved backward and it becomes the state of the cap 8 as shown by the dash line in FIG. 5.
In order to obtain the complete effect of the baffle, both baffles 7 and 70 may be used together, for example, the baffle 70 is used for the first place and then the baffle 7 is used on the downstream portion of the conveyor belt 1. Of course, the above-explained baffles 7 and 70 are only exemplar embodiments, and any device which gives the same effect may be used in place of the above baffles.
FIGS. 6, 7 and 8 illustrate another embodiment of the present invention, in which an arranging means A is provided to the guide passage of the caps to the cap receiving device in the downstream portion of the feeding apparatus. As shown in FIG. 6, the conveyor belt 1 is further elongated by providing it with another pulley 18 to convert the direction of the conveyor belt 1, and said arranging means A is installed on the elongated portion of the conveyor belt 1. The detailed structure of the arranging means A is shown in FIGS. 7 and 8. That is, in said figures, the numerals 19 and 20 are structural frames which are disposed on the both sides of the conveyor belt 1 leaving a proper space apart. In the downstream portion of the conveyor belt 1, the structural frames 19 and 20 are provided with guide fences 22 and 23, and the guide faces 22a and 23a of said fences define a guide passage 21 on the center line of the conveyor belt 1, the width of which passage 21 allows a cap to pass through. The upstream portion of said structural frame 19 is provided with an inclined guide fence 24, which comprises a stationary fence having an inclined face 25a in the upstream half and a movable fence 26 in the downstream half. The top of the attachment rod 27 of said movable fence 26 is pivoted to the structural frame 19 by a pin 28 and is further provided with a coil spring 29 between the frame 19, thereby the one end portion of the movable fence 26 is pressed against the shoulder 25b of the stationary fence 25. Between the top of said movable fence 26 and said guide fence 22, an outlet 30 is opened to discharge the excess caps to the side portion. The numeral 31 is a return hopper to receive the caps from said outlet 30 and to transfer the caps to the hopper 4 in FIG. 6.
The swingable fence 32 defines a tapered cap guide section 33 with said inclined guide fence 24, in which the caps 12 are passed to said guide passage 21. Said swingable fence 32 is attached to the frame 20 by a pin 34, and a coil spring 35 is provided between the projected portion of the swingable fence 32 and the downstream portion of said frame 20, further the top of said projected portion is provided with a roller 36 which is engaged with a rotating cam 37 on the side of the frame 20. Accordingly, when the roller 36 is engaged with the shorter diameter portion of said cam 37, the arc-shaped spring plate 32a on the top of said swingable fence 32 is swung to the outlet 30. While, in FIG. 8, the numeral 38 indicates a transparent cover plate which covers said guide passage 21.
As explained in the above with regard to FIG. 6, the caps 12 which are attached here and there on the surface of the conveyor belt 1 with back side out, are transferred into this section. In the first place, the caps 12 near the frame 19 are guided by the inclined face 25a of the stationary fence 25 to the guide section 33, and the caps 12 near the frame 20 are guided along the swingable fence 32 to the guide section 33, then the caps are introduced one by one into the guide passage 21, thereby the caps 12 are fed in good order to the cap placing apparatus. However, as shown in FIG. 6, the intervals of the caps 12 attached on the conveyor belt 1 are irregular and they often accumulate and become clogged in the guide section 33. Therefore, in order to pass the caps 12 into the guide passage 21 in good condition with a desired speed, the rotating cam 37 is driven by a proper driving means (not shown) to swing the swingable fence 32 around the pin 34. Thereby the spring plate 32a at the top portion of said fence 32 is moved toward the outlet 30, and the accumulated caps 12 in the inlet portion of the guide passage 21 are swept away through the outlet 30 into the hopper 31, then the caps 12 are further moved into the lower hopper 4 in FIG. 6. On this occasion, the movable fence 26 is pushed by the caps 12 and turned counterclockwise around the pin 28 against the force of the spring 29. Thus the outlet 30 is enlarged and the discharging action of the swingable fence 32 can be carried out smoothly. After this discharging operation by the swingable fence 32, said fence 32 and the movable fence 26 return to the original positions and the cap feeding is continued again. As the above-mentioned discharging of the accumulated caps are carried out intermittently according to the rotation speed of the rotating cam 37, there is no fear of the stagnation of caps in the inlet portion of the guide passage 21 and satisfactory feeding of the caps 12 can be carried out.
Still more, this arranging means A can be provided on the second conveyor belt in FIG. 6 in addition to that on the first conveyor belt 1, where thus arranged caps are fed to another cap placing apparatus without returning to the hopper 4. Further, the guide passage 21 in FIG. 7 is not restricted to one, for example, two guide passages may be provided according to the speed of the conveyor belt 1.
As disclosed in the above, the tapered cap guiding section is provided with the inclined guide fence and the swingable fence on both sides of the conveyor belt to guide the caps smoothly into the guide passage, therefore the caps which are irregularly attached on the conveyor belt do not clog with each other and are moved to the central portion of the conveyor belt, thereby the caps can be introduced into the guide passage effectively. Further, the outlet is formed on one side of the top portion of said inclined guide fence, and the swingable fence is swung intermittently against said outlet, therefore the caps which stagnate in the inlet portion of the guide passage can be discharged automatically through the outlet to the side portion, thus the feeding of the caps in good order to the cap placing apparatus can be carried out and the operator's work to remove the stagnated caps can be eliminated, which are very advantageous as compared with the conventional cap feeding apparatus.
It should be emphasized, however, that the specific embodiments described and shown herein are intended as merely illustrative and in no way restrictive of the invention.
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A feeding apparatus for caps which are made of magnetic substance to feed the caps of bottles to a cap placing apparatus one by one in good order in a continuous manner, in which said feeding apparatus comprises: a magnetic first conveyor belt to attract and transfer the caps from a hopper; a baffle to remove overlapping caps on said first conveyor belt; a second conveyor belt to select out the caps which are in the wrong position; a guide passage to feed the caps one by one to said cap placing apparatus; a set of an inclined guide fence and a swingable fence to define a guiding section; an outlet to discharge excess caps; and a swinging means to swing said swingable fence.
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REFERENCES CITED
Douglas D. J. and French J. B. (1990) Mass spectrometer and method and improved ion transmission, U.S. Pat. No. 4,963,736, Oct. 16, 1990
Douglas D. J. and French J. B. (1992) Collisional Focusing Effects in Radio-Frequency Quadrupoles, J. Am. Soc. Mass. Spectrometry, 3 (4): 398-408
Fenn J B, Mann M, Meng C K, Wong S F, Whitehouse C M, Electrospray ionization for mass-spectrometry of large biomolecules, Science 246 (4926): 64-71, 1989
Fernández de la Mora, J. and D. E. Rosner, Inertial Deposition of Particles Revisited and Extended: Eulerian Approach to a Traditionally Lagrangian Problem, Physico-Chemical Hydrodynamics 2, 1-21 (1981).
Fernández de la Mora, J., Drastic improvements on the resolution of aerosol size spectrometers via aerodynamic focusing: the case of variable-pressure impactors; Chemical Engineering Communications, 151, 101-124 (1996).
Fernández dc la Mora J. (2000) Electrospray ionization of large multiply charged species proceeds via Dole's charged residue mechanism, Analytica Chimica Acta, 406, 93-104
Franzen, J. and Brekenfeld, A. (2004), Ion-guide systems, U.S. Pat. No. 6,674,071, Jan. 6, 2004
Fuerstenau, S, P. Kiselev and J. B. Fenn, ESIMS in the Analysis of Trace Species in Gases, Proceedings of the 47th ASMS Conference on Mass Spectrometry (1999) Dallas Tex.;
Fuerstenau, S., Aggregation and Fragmentation in an Electrospray Ion Source, Ph.D. Thesis, Department of Mechanical Engineering, Yale University, 1994.
Hutchins D. K., Holm J., Addison S. R., Electrodynamic focusing of charged aerosol-particles, Aerosol Sci. & Tech. 14 (4): 389-405, 1991
Liu P., Ziemann P. J., Kittelson D. B., et al. (1995) Generating particle beams of controlled dimensions and divergence. 1. theory of particle motion in aerodynamic lenses and nozzle expansions, Aerosol Sci. Tech. 22: 293-313
Liu P., Ziemann P. J., Kittelson D. B., et al. (1995), Generating particle beams of controlled dimensions and divergence. 2. Experimental evaluation of particle motion in aerodynamic lenses and nozzle expansions, Aerosol Sci. Tech. 22: 314-324
McDaniel, E. W. and Mason, E. A. (1973) The mobility and diffusion of ions in gases, Wiley New York
Robinson A. (1956) On the motion of small particles in a potential field of flow, Comm. Pure & Applied Math. 9, 69-84
Smith R. D. and Shaffer; Scott A. (2000), Method and apparatus for directing ions and other charged particles generated at near atmospheric pressures into a region under vacuum, U.S. Pat. No. 6,107,628, Aug. 22, 2000
Tolmachev, A. V., I. V. Chernushevich, A. F. Dodonov, K. G. Standing, A collisional focusing ion guide for coupling an atmospheric pressure ion source to a mass spectrometer, Nuclear Instruments and Meth. Phys. Res. B 124 (1997) 112-119
Tolmachev, A. V., H. R. Udseth and R. D. Smith, Radial stratification of ions as a function of mass to charge ratio in collisional cooling radio frequency multipoles used as ion guides or ion traps, Rapid Commun. Mass Spectrom. 14, 1907-1913 (2000)
Tolmachev, A. V., H. R. Udseth, R. D. Smith, Modeling the ion density distribution in collisional cooling RF multipole ion guides, International Journal of Mass Spectrometry 222 (2003) 155-174
Ude, S.; J. Fernandez de la Mora, B. A. Thomson, (2004) Charge-induced unfolding of multiply charged polyethylene glycol ions, J. Am. Chem. Soc., 126, 12184-12190
Whitehouse, C. M., F. Levin, C. K. Meng, and J. B. Fenn, Proc. 34th ASMS Conf. on Mass Spectrom. and Allied Topics, Denver, 1986, p. 507.
Wu, C.; W. F. Siems, and H. H. Hill, Jr., Secondary Electrospray Ionization Ion Mobility Spectrometry/Mass Spectrometry of Illicit Drugs, Anal. Chem. 2000, 72, 396-403.
FIELD OF THE INVENTION
This invention is concerned with the problem of concentrating ions existing at relatively high pressure in order to increase the sensitivity of analytical instruments such as mass spectrometers or other devices capable of analyzing such ions.
BACKGROUND OF THE INVENTION
General Background
There are many situations when small particles and ions suspended in a gas need to be analyzed and detected. For instance, to monitor pollution in the environment. Also in analytical applications, where ions formed at atmospheric pressure are introduced into mass spectrometers or other analyzers for the purpose of determining their concentrations and other characteristics, such as their mass, charge, electrical mobility, etc. These small particles or ions may preexist in the ambient, but they are often produced at atmospheric pressure by special procedures such as chemical ionization, electrospray (ES) ionization etc. The analytical instruments where they are sampled generally take a limited gas flow rate, whereby their sensitivity is limited by the concentration of the suspended particles or ions in the gas. It is therefore desirable to increase this concentration prior to sampling into such instruments. There are other instances where one wishes to concentrate ions or charged particles for purposes other than analyzing them. For instance, when these ions are used to charge neutral vapors existing in the atmosphere by virtue of their finite vapor pressure, whereby, once charged, such vapors are more easily detected. Charging neutral species is desirable, for instance, for the purpose of sniffing explosives or other substances of interest in environmental, food, or other applications. In this case it is convenient to distinguish between the charging ions or particles, and the ionized vapors. Charging of volatiles can be done in either bipolar or unipolar ionic atmospheres. In the first case, large concentrations of coexisting positive and negative ions can be generated, for instances with ionizing radiation or radioactive materials, though recombination of ions of opposite sign tends to discharge both the charging ions and the ionized vapors, thus limiting the charging probability of neutral species. In the case of volatile charging in unipolar atmospheres, space charge limits the concentration of the charging species, leading also to relatively small charging probabilities of the vapors, at most of the order of 10 −4 ; but typically less. It is evident that the charging probability of these volatiles is proportional to the concentration of charging ions. It is therefore desirable to increase the concentration of charging species and keep it high over volumes much larger than currently allowed by space charge dispersion. One should note here that charging of volatiles may be achieved not only by charge transfer from other charged ions (for instance by proton transfer from protonated water clusters), but also by charge transfer from a spray of charged drops. The later method has been pioneered by John Fenn and his colleagues (Whitehouse et al. 1986; Fuerstenau, et al. 1999; Fuerstenau, 1994; Wu et al. 2000) with charged sprays of volatile liquids produced via so-called electrospray (ES; Fenn et al, 1989). Hence, the term ions in charging ions is used in the wide sense to mean ions, evaporating charged drops, or the mixture of both produced by electrosprays or other charged sprays.
Several schemes have been developed to achieve pre-concentration of species, as described for instances by Liu et al. (1995a, b) for relatively large aerosol particles, or by Douglas and French (1990, 1992) and Smith and Shaffer (2000) for ions. These techniques are all based on the finite inertia of the particles, as revealed by the early theoretical work of Robinson (1956; see also Fernandez de la Mora, 1996). Because the inertia of very small particles at relatively large or near atmospheric pressures is very small, none of these schemes has succeeded so far at achieving the desired concentration of ions at atmospheric pressure. The focusing element claimed in the Douglass-French patent is “a first rod sot” and is required to be in a “first vacuum chamber”. The alternative funnel system of Smith and Shaffer (2000) is claimed in their patent to function up to 1 Bar (0.99 atmospheres). However, the many embodiments of their invention tried to date with mass spectrometric advantage, have always relied on focusing elements operating at pressures substantially below one atmosphere. In all known focusing devices used to date in which substantial concentration has been achieved for mass spectrometry applications, the gas sample is initially passed from its source (often at atmospheric pressure) into a region of reduced pressure. On the other hand, the notable sensitivity advantages yielded by the concentration schemes currently practiced at reduced pressure could be much enhanced if the sample gas were also enriched substantially at its initial source pressure (often atmospheric). The present invention teaches how to achieve this desired concentration at relatively high pressure, including atmospheric and super-atmospheric conditions. This advantage is evident from the fact that the maximum sensitivity achievable by an instrument sampling a fixed flow rate of gas is proportional to this flow rate times the sample concentration. If this concentration is increased by a certain factor F prior to the inlet to the instrument, the instrument's sensitivity can be increased by a factor as high as F. The present invention teaches also how to greatly increase the charging probability of neutral species in a gas, by performing the charging inside a charged particle concentrator. The charging probability is increased not only by obtaining unusually high concentrations of charging species and maintaining them over large volumes, but possibly also by concentrating the ionized vapors in the same charging device.
The two types of concentration devices known currently are either aerodynamic or electrodynamic. The theory for the first kind is relatively well known, and the obstacles to achieve aerodynamic focusing of small particles at atmospheric pressure are difficult to overcome due to basic fluid dynamic reasons. The improvement to be introduced by this invention is therefore directed mainly to electrodynamic focusing devices, and can therefore be effective only for charged particles. Our approach will be to first analyze the ion guide system most often used, a linear multipole lens conceptually identical to those introduced by Douglas and French (1990, 1992) to achieve ion focusing at reduced pressures. These systems involve a relatively large number of free parameters (gas pressure; rod radius, length and other geometrical characteristics; frequency of alternation of the voltage (RF) and voltage; ion mass and electrical mobility, etc.), such that the search for conditions suitable for effective operation at elevated pressure has in the past been unsuccessful, in spite of considerable efforts invested in this effort. This has led to the widespread opinion that effective ion concentration at atmospheric conditions is impossible. The theory taught here, however, enables the efficient identification of optimal operating parameters, and shows what combination of characteristic dimensions and frequencies must be used for useful focusing under atmospheric pressure. The theory is taught for the case of quadrupole lenses, but it can be readily applied to other multipolar systems such as hexapoles, octupoles, etc. It can be similarly applied to other focusing geometries such as the funnels of Smith and Shaffer (2000). It is not restricted to the case of periodic (or quasi periodic) systems in time, but applies also (with suitable modifications) to periodic (or quasi periodic) systems in space, such as the aerodynamic lenses of Liu et al. (1995a, b), or their suitable electrostatic analogs. One should note that approximate theories describing the behavior of ions in multipole fields (or ion funnels) have been developed. These theories were originally conceived for ions moving in a vacuum, but they have been generalized to account for collisions with a background gas. One must however note that available so-called pseudo-potential theory holds only in the limit of large inertia, and does not apply at large pressure. The theory taught here is therefore new in the realm of electrostatic focusing, even though some elements of it have been previously published by Tolmachev et al. (1997, 2000, 2003)
Theoretical Background on of Inertial Focusing in Time Periodic Electric Fields
Consider the differential equation
ⅆ 2 x ⅆ t 2 + 1 τ ⅆ x ⅆ t + a F ( x ) cos ( Ω t ) = 0 , ( 1 )
where the first term is the particle acceleration in the x direction, the second term accounts for the drag exerted by the gas medium on the particle, and the third term is the negative of an external acceleration, taken to vary periodically in time with an angular frequency Ω. The particle relaxation time τ is simply related to its electrical mobility and mass through Einstein's formula (16), while the linear relation between drag and speed implicit in equation (1) is generally suitable under high-pressure conditions. (1) is a one-dimensional form of Newton's vector equations, which is suitable for simple geometries such as linear multipole systems. Other geometries requiring a three-dimensional treatment are evidently conceivable, as are situations where the drag presents nonlinear effects and the second term of (1) needs to be generalized. Other more complex time dependent forces can evidently also be considered, including not only electrical, but also magnetic or fluid dynamic (associated to net motion of the background gas).
Introducing Eulerian coordinates x, y for the velocity field u (Fernandez de la Mora and Rosner, 1981), (1) may be written:
∂ u/∂t+u∂u/∂x+u/τ+aF ( x )cos(Ω t )=0 (2)
This representation is eminently generalizable to the more complex three dimensional and nonlinear situations previously mentioned. We will consider first the limit of small inertial effects, when the nonlinear term u ∂u/∂x is relatively small and can be neglected to first approximation. We shall see that this approximation is particularly well justified under the conditions of high pressure of particular interest to this invention. The differential equation can then be integrated into the purely periodic solution
u = - a τ 1 + Ω 2 τ 2 F ( x ) [ cos ( Ω t ′ ) + Ωτsin ( Ω t ) ] ; ( 3 )
where a rapidly decaying term of the form A(x) e −t/τ has not been included. The neglected term u∂u/∂x can now be evaluated to yield,
u ∂ u / ∂ x = a 2 τ 2 2 ( 1 + Ω 2 τ 2 ) 2 F F x [ cos ( Ω t ) + Ω τsin ( Ω t ) ] 2 ; F x = ∂ F ∂ x ( 4 )
Net Drift.
If the correction (4) is now included in (2), it contributes two types of terms; some periodic with frequency 2Ω, another corresponding to the net drift velocity u o :
u
o
=
-
a
2
τ
3
2
(
1
+
Ω
2
τ
2
)
F
F
x
(
5
)
If one now averages the motion over one period, the harmonic contributions drop out, and the net motion is just that given in (5).
One can readily see that the three-dimensional generalization of (2) & (5) are:
∂
u
/
∂
t
+
u
·
▽
u
+
u
/
τ
+
a
F
~
(
r
)
cos
(
Ω
t
)
=
0.
(
2
′
)
u
o
=
-
a
2
τ
3
2
(
1
+
Ω
2
τ
2
)
F
·
▽
F
.
(
5
′
)
Making use of the fact that ∇×F=0, F·∇F=½∇(F·F), it follows that ions tend to focus at points where F·F is a minimum
Limits of Validity of the Small Inertia Limit.
The validity of (5) is restricted by two types of considerations. First, the term u∂u/∂x treated as a perturbation must be small compared to those retained, hence, u∂u/∂x<<u/τ, or
τ∂ u/∂x<< 1. (6)
This is equivalent to a conventional small Stokes number hypothesis (Fernández de la Mora and Rosner, 1981). Under atmospheric pressure conditions, even large ions have minute relaxation times τ of the order of 10 −9 s, so that (6) would hold even at uncommonly large frequencies of 100 MH. In addition, the amplitude of the harmonic contributions in (3) averaged out in (4) must be sufficiently small to preclude ion loss on surrounding electrodes. If we introduce the Lagrangian coordinate y of a particle, its evolution in terms of the Eulerian coordinates x, t obeys:
dy/dt=∂y/∂t+u ( x,t )∂ y/∂x=u ( x,t ), (7)
where u(x, t) is given by (3). Introducing the new dependent variable z defined in (8a), (7) becomes (8b)
z=y−x; ∂z/∂t+u∂z/∂x= 0. (8a, b)
The characteristic equations of this first order partial differential equation are separable:
z = constant along ;
ⅆ t [ cos ( Ω t ) + Ωτsin ( Ω t ) ] = - ⅆ x ( 1 + Ω 2 τ 2 ) a τ F ( x ) ( 9 )
The Case of a Quadrupole.
In the special case of an radio frequency (RF) quadrupole, aF(x) is defined in (10a), where the ion charge is e, m is its mass, V is the RF potential, 2R the distance between two opposite electrodes, and the angular frequency ω is defined approximately in (10b)
aF ( x )=ω 2 x; ω 2 =2 eV/( mR 2 ). (10a, b)
Then, the small Stokes number condition (6) becomes:
ω 2 τ 2 1 + Ω 2 τ 2 << 1. ( 11 )
(9) may also be integrated explicitly to yield
ln ( y / x o ) = ( ω 2 τ / Ω ) sin ( Ω t ) + Ω τcos ( Ω t ) 1 + Ω 2 τ 2 , ( 12 )
where x o is a constant of the motion simply related to the initial value of y. Because the maximum value of the second right hand side factor in (12) is of order unity, y/x o is of the order of exp(ω 2 τ/Ω), and the group ω 2 τ/Ω can at most take values of order one:
Ωτ>ω 2 τ 2 . (13)
Typically then, ωτ must be small, while Ωτ can be large or small, but it cannot be smaller than the generally small number ω 2 τ 2 .
The time needed for focusing follows from the time-averaged equation for u:
dx/dt=−u o , (14)
which, in the case of a quadrupole, is linear in x, whereby x decays as exp(−t/t o ), with a characteristic time
t o =2τ(1+Ω 2 τ 2 )/(ωτ) 4 (15)
Because ωτ needs to be small for these results to hold, it follows that this decay time or focusing time is considerably larger than τ. Very worth noting is the cubic dependence of t o on pressure through the term τ˜1/p, which explains quantitatively the qualitatively well known difficulty of extending to high pressure the operating range of a quadrupole lens. Indeed, a quadrupole designed to work at the relatively high pressure (by current standards) of 7.6 Torr, would need at atmospheric pressure a time 1 million times larger to focus than under design conditions. Equally worth noting is that t o varies with the −4th power of ω, and hence varies as the −4 th power of the lens dimension R and the second power of its voltage. Note in particular that the maximum voltage that can be used is considerably larger at atmospheric pressure than in the Torr range, and this compensates in part for the negative effect of increasing pressure. However, the principal means available to achieve moderate focusing times at high pressures is to use a quadrupole dimension R considerably smaller than in current practice. Fortunately, the fact that t o ˜R −4 enables effective focusing at manageable values of R of the order of 1 mm.
Typical Values
Einstein's equation may be written
τ= mZ/e, (16)
while the electrical mobility of a sphere of diameter d is
Z/e= 0.441( kT /μ) 1/2 /( pd 2 ), (17)
where p is the background gas pressure, μ its molecular mass (28.8 amu for air) and kT its temperature in energy units. Taking a typical value for electrospray ions, m/c=1 kDalton, and favorable conditions of high RF voltage, V=3 kV, and small R (=1 mm), then ω=2.4 10 7 s −1 (5.38 10 7 s −1 when m/e=200 amu).
Using a material density of 1 g/cm 3 for the ions, p=1 atmosphere and a particle diameter of 5 nm (m=39.4 kDalton) we find τ=3.3 10 −9 s, hence ωτ=0.079. For an ion of mass 200 amu and Z=2 cm 2 /V/s, τ=4.1 10 −10 . The small inertia condition (11) is therefore well met. The alternative condition (13) requires that Ω>1.89 10 6 1/s (a frequency of 300 kHertz), which is generally exceeded in RF ion guides. On the other hand, due to the damping factor (1+Ω 2 τ 2 ) in the drift speed (3), it is preferable to keep Ωτ<1, hence Ω<3 10 8 s −1 (frequency below 48 MHz), which is also generally satisfied in RF ion guides. According to (15), the corresponding time required for focusing is t o =1.7 10 −4 s at an RF frequency of 2 MHz. This is reasonably fast, and would only require a quadrupole length of some 20 cm to increase the ion concentration by a factor of 1000, even if the gas was moving at the speed of sound for room temperature air (340 m/s). An axial length of 6 mm would suffice for a gas jet moving at 10 m/s. A concentration factor of 1000 would imply that the inlet stream-tube of about 2 mm (R=1 mm) would shrink by a factor of 1000 1/2 into a diameter of 63 μm, considerably smaller than the typical pinhole diameter of 250 μm of a mass spectrometer with an atmospheric pressure source. One could hence use a larger R value to fit ideally with the inlet orifice, but we will not pursue this optimal matching until we take Brownian diffusion and space charge considerations into account. We can nonetheless conclude that a small quadrupole running under atmospheric pressure can achieve a large concentrating effect. It would have the extra advantages over low pressure quadruples of being fragmentation-free, readily integrated to an electrospray source, small, compatible with low voltage operation, and having a wider mass range where focusing is effective. A key practical advantage of the type of atmospheric pressure ion focusing just discussed is that a given ion current could be passed through a considerably smaller pinhole inlet to a mass spectrometer. Furthermore, since the ions would be confined to the axis of the gas jet ingested, radial expansion of the gas into the vacuum would lead to a much reduced widening of the ion beam, so that a second stage of low pressure ion guide might not be needed, and, if present, it would pass a larger fraction of the ions into the high vacuum region of the MS.
Other Factors Affecting the Width of the Ion Beam
The main widening mechanisms available are Brownian motion and space charge. Brownian motion Let r denote the radial variable in a linear RF quadrupole, which could be either x or y. Under conditions of equilibrium the beam would expand radially as a result of diffusion, but would be confined by the net convective speed u o towards the axis given in (5), The ion number density n (1/cm 3 ) would then be governed by:
− D∂n/∂r+nu o =0, (18)
where the diffusion coefficient D is given by Einstein's formula as D=kTτ/m. Its solution is
n
=
n
o
exp
(
-
r
2
/
Δ
2
)
;
Δ
2
=
-
4
k
T
(
1
+
Ω
2
τ
2
)
m
ω
4
τ
2
.
(
19
)
Under the conditions of the quadrupole and the ions just described, the beam width Δ is of only 4 μm, much smaller than the typical MS inlet hole radius of 125 μm.
Space Charge
The limit just described holds in the absence of space charge. The question now is what current levels can be passed without substantial increase of ion beam cross section.
We consider the asymptote where the beam is already focused and does not evolve further in the axial direction. Then Poisson's equation is one-dimensional:
1 r ⅆ r E ⅆ r = n e ɛ o ( 20 )
while the mass conservation equation for the number density n of ions is
- D ⅆ n ⅆ r + n ( Z E - α r ) = 0 ( 21 )
where αr is the drift velocity of the ions in the quadrupole, given by (5) and (10) as:
α
=
ω
4
τ
3
2
(
1
+
Ω
2
t
2
)
.
(
22
)
Eliminating n in terms of E in (20) and substituting it into (21) yields a second order differential equation for the field E. It can be cast into the simpler form (25) by introducing the variables:
q
=
Z
E
r
2
D
;
y
=
α
r
2
2
D
(
23
,
24
)
ⅆ
2
q
ⅆ
y
2
=
ⅆ
q
ⅆ
y
(
q
y
-
1
)
(
25
)
The symmetry condition at the axis requires that E vanishes linearly with r, whereby q is linear with y:
q→a 1 y as y→ 0. (26)
This provides initial values at the axis r=0 for q=0 and dq/dy=a 1 , so that numerical solutions can be obtained in terms of the single parameter a 1 . One can also provide a Taylor expansion solution at small y:
q=a 1 y+a 2 y 2 + . . . +a n y n + . . . (27)
Substituting (26) into (25) and canceling terms of successive order in y we find:
a 2 =a 1 ( a 1 −1)/2
6 a 3 =3 a 1 a 2 −2 a 2
12 a 4 =a 1 a 3 =2 a 2 2 +3 a 3 ( a 1 −1)
etc. (28)
The structure of the solution is as follows. The line q=y (a 1 =1) is a singular exact solution, which separates trajectories curved upward (a 2 >0) from others curving downwards and evolving towards a horizontal line q=q o (also an exact solution to (25), though not satisfying (26)). The expected behavior is a number density n confined to a region near the axis, and decaying rapidly to zero beyond a certain radius. In the outer region where n=0, E decays as 1/r, and q tends to a constant. One can easily see that such constant asymptotes are attractors to the solution at increasing y. Indeed, q/y<<1 in the vicinity of this asymptote, whereby (25) becomes linear with solutions q=A+B e −y , decaying rapidly to a constant. In contrast, upward curving solutions with a 1 >1 eventually exhibit the opposite behavior with vertical asymptotes.
The structure of the physically meaningful solutions (a<1) computed numerically is shown in FIG. 1 , where the horizontal and vertical variables are proportional to r and n, respectively One sees that at small initial values of a=(dq/dy) y=0 , the height increases with a, but the width changes little remaining close to the diffusion limit. At increasing (dq/dy) y=0 , both the height and the width increase monotonically. Finally, as a approaches unity, the ion density takes an almost constant value while the width keeps increasing indefinitely. This asymptote corresponds to the limit of the maximum charge density or “space charge limit” that can be attained in the quadrupole:
en max =2∈ o α/Z (29)
Assuming that this space charge limit has been attained and that the beam is wide enough for the ions to fill all the gas streamlines sucked by the inlet orifice, the ion current ingested is equal to the inlet flow rate Q times en max . For a typical value of Q=0.5 lit/min, the maximum ingested current we obtain for the same values used in the previous example is of 2.75 nA. This current is larger than can be ingested under most conditions, typical of atmospheric pressure ionization mass spectrometers (API-MS) systems, with the exception of so-called nanospray. In this later case the initial electrospray drops are so small that there is ample time for drop evaporation and ion formation even when the electrospraying tip is within an orifice radius of the sampling orifice, and the whole spray (several tens to one hundred nA) may be sampled into the vacuum. For most other situations of practical interest in electrospray mass spectrometry (ES-MS) the proposed atmospheric pressure lens would lead to considerable increases in sensitivity.
Species Stratification Under Space Charge Saturation
Tolmachev and colleagues (2000, 2003) have investigated space charge effects in ion guides and shown that there may be radial stratification of various ion types. A similar effect can be seen in our space charge model. Imagine there is a dominant ion (say from the ES buffer), and let's denote its properties α and Z with the subscript b (for buffer). Then, E=rα b /Z b . Let us suppose there is a trace quantity of another ion with different properties α i , Z i . Its radial velocity v i =Z i E−α i r=rZ i (α b /Z b −α i /Z i ) can only be negative (movement towards the axis, hence concentration) provided that
α i /Z i >α b /Z b (30)
Hence, the ions with the largest α/Z will occupy the regions closest to the axis. In the polarization limit governing the mobility of small ions (McDaniels and Mason, 1973), this corresponds to the heaviest ions. Interestingly, Tolmachev et al. (2000) come to the opposite conclusion, perhaps because they consider the limit of small or intermediate pressures. In the different application of electrospray sources, the lighter ions rejected to the periphery are the buffer ions used to impart electrical conductivity to the liquid solution and hence provide a good electrospray. The heavier ions concentrating near the axis are therefore the most analytically relevant ions. In the different application of electrospray charging of neutral vapors, the use of a quadrupole to concentrate the electrospray drops (or ions) has two advantages. First, it concentrates the charging species (ions or drops) into the axis region at concentrations substantially larger than they would have in the absence of a quadrupole. This evidently enhances the charging efficiency of neutrals in the ambient going near the axis. Second, once charged, these ionized vapors are not displaced to the periphery by the dominant charge, but are instead conveniently kept near the axis, ready to be preferentially sample into the MS. In the case where drops rather than ions are the charging species, the situation may perhaps be the opposite initially, with the drops occupying the vicinity of the axis. But once drop evaporation is complete, provided there are no nonvolatile salt-forming species in the spray, the analytically interesting heavy ions occupy their place near the axis.
In conclusion, the use of RF fields created by arrangements of conductors with characteristic diameters and inter-electrode distances of the order of one millimeter is able to produce inertial effects sufficiently large to concentrate considerably ions and small particles at pressures as high as 1 atmosphere, prior to their introduction into an analytical instrument such as a mass spectrometer.
Axial Movement of the Ions
In the case of a relatively long quadrupole, an axial field is necessary to move the ions towards the MS inlet. This axial field does not exist naturally because the rods are at a fixed mean voltage all along their axis. Axial fields have nonetheless been implemented earlier by Sciex patents, relying on slightly conical rods (or a conical arrangement of the axes of cylindrical rods). Also by Brucker patents relying on the creation of an axial field outside the quadrupole rods, and through its finite radial penetration into the quadrupole axis (Franzen and Brekenfeld 2004). These ideas, however, are intended for low-pressure applications, where small axial fields suffice to compensate for a very small drag. Hence, their utility is uncertain under atmospheric pressure, where the drag acting on the ions is very high. The present invention will therefore rely not only on these previously taught schemes of axial propulsion, but also on a simpler convective scheme.
Axial Fluid Motion
The approach relies simply on a net axial flow of gas. A conventional multipole lens system has openings between the various rods on its sides, so any initial flow speed implemented at its entry would decay towards the exit region. This problem may be alleviated by closing the quadrupole on its four side openings (or the hexapole on its six lateral openings, etc.), for instance, by inserting a dielectric material in the lateral open space between the various rods. The presence of a dielectric material with dielectric constant ∈ larger than 1 evidently modifies the electric fields inside the RF lens, but when the closure is implemented outside rather than inside the point where the various rods are closest to each other, such effects are relatively minor and do not alter in any significant way the general considerations made here. The advantage of this laterally closed quadrupole is evidently that an axial pressure gradient can be imposed leading to a controllable axial velocity.
We have indicated that this invention is not limited to multipole geometries, but includes also the ion guide types of U.S. Pat. No. 6,107,628 by Smith and Shaffer. These authors refer to their ion guides as ion funnels, because their shape has always been converging from a wide entry section to a narrow exit region. For our present purposes, these ion guides have the advantage of being closed laterally, as they are formed by approximately spatially periodic arrangements of conductors and insulating plates perforated so as to create an internal opening. This spatially periodic system of lenses leads to electrodynamic focusing in a manner similar to that of the aerodynamic focusing of Liu et al. (1995). Ion funnels have been constructed by the time consuming process of laying conducting and insulating plates one above the other, with their perforations of diminishing area executed prior to this assembly. The precision of this manual technique does not lend itself easily for our purpose of producing lenses with small characteristic cross section, suitable for high pressure operation. However, if the unperforated conducting and insulating plates and conductors are secured together, this assembly can then be perforated at once with a cylindrical drill of small dimensions, or with other conventional schemes used to perforate bulk material with cylindrical shapes, or other desired shapes, including tapered geometries.
SUMMARY OF THE INVENTION
This invention uses ion guides at unconventionally high pressures and unconventionally small dimensions to concentrate ions and other charged particles near the ion guide axis. This concentrating effect is exploited in various applications, including increasing the sensitivity of other analytical instruments, and increasing vapor charging efficiencies. Besides the small dimensions enabling effective concentration at near atmospheric pressures, the invention differs from prior art to concentrate ions in the absence of a high pressure ratio between the ion guide region and a preceding chamber through which ion carrying gases are conventionally introduced, The gas movement through the ion guide can therefore be relatively slow, and can even proceed in the direction normal to that of the movement of the ions.
DESCRIPTION OF THE FIGURES
FIG. 1 shows the ratio of the ion density in units of its maximum possible value as a function of the dimensionless radial position within a quadrupole lens at various levels of filling of the traps.
FIG. 2 is a schematic of a device for concentrating ions form an electrospray ion source based on a quadrupole lens type ion guide.
FIG. 3 is a schematic of an ion guide based on pairs of conducting and insulating plates.
FIG. 4 is a schematic of an ion guide based on two or more coiled wires.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of this invention is shown in FIG. 2 . It consists of an electrospray needle ( 1 ) facing an electrode ( 2 ) with an opening of about 1 mm in radius, not necessarily exactly coaxial with the emitting tip. Shortly after said orifice, and coaxial with it, is a linear multipole lens ( 3 ) run in the RF only mode. This RF lens is similar to that described in the work of Douglas and French, but the gas inside it is maintained here at a pressure comparable to that prevailing in the ion source, while the rod diameter and the opening between rods are much smaller here, of the order of 1 mm. In one embodiment of the invention, the electrospray source is fully enclosed in a chamber maintained at a pressure that may be smaller than that of the surrounding medium. Similarly, the RF lens may be closed on its exit region. It is closed on its sides by filling the gap between poles with an insulator ( 4 ), so that the pressure in the region inside the poles may be maintained below its entry value. Drying gas in the ambient region between the interior of the ES chamber and the interior of the RF lens may therefore enter into the electrospraying region through the orifice, in order to assist drop evaporation. This dry gas can similarly enter inside the RF lens, and move through it to facilitate the axial movement of the ions towards the exit of the lens. The electrospraying needle ( 1 ) may in this case be at a voltage a few kV above (or below for negative sprays) the perforated plate ( 2 ), which is in turn kept at a voltage higher than the reference voltage in the RF rods (generally ground). In an alternative embodiment, the electrospray is directed into the entrance of the multipole lens, without an intermediate perforated plate, and with the spray not necessarily coaxial with the lens. Dry gas may be blown (or sucked) at a relatively large speed into the entrance of the multipole lens, coaxially with it, in such a fashion that it entrains into the lens some of the ions and charged drops formed by the electrospray. In a third configuration the electrospray needle is approximately coaxial with the multipole lens and its spraying tip is very near the entrance to the lens, or even inside it, so that the full spray or a fair fraction of it is initially injected into the RF lens. In a fourth configuration the electrospray is produced in a closed chamber, and driven by a gas flow through a tube or a short nozzle, forming a jet that is directed into the entrance region of the RF lens. The transfer tube may be heated to help desolvation. A pre-filtering system such as a differential mobility analyzer (or another device separating ions according to their different motion in either electric fields or in combined electric and flow fields) may even be installed between the entrance and the exit of this tube. In either of these four configurations or in other related ones, some of the drops and ions formed are confined by the focusing effect near the multipole axis, even in situations where a drying gas is flowing with a contrary radial component. These ions are simultaneously moving axially along the lens, towards its opposite end, on whose vicinity the sampling orifice leading to a mass spectrometer or another analyzer is located. This axial movement of ions is propelled by a combination of the space charge field, the repulsive field from the electrospray needle, the gas suction from the inlet orifice leading to the MS, the axial speed induced on the gas by various additional means, or an external axial field created by a suitably arrangement of the electrodes or rods in the RF lens, or other external electrodes. As a result, the region in the vicinity of the sampling orifice leading to the MS is bathed by ions at a concentration considerably larger than that achievable in the absence of the RF lens. Furthermore, the confinement effect enables keeping the ions and charged drops axially confined for an unusually large time (or axial distance), allowing efficient desolvation and further production of ions.
In a second embodiment of the invention ( FIG. 3 ), the laterally closed multipole lens is substituted by a laterally closed periodic arrangement of insulating ( 5 , 6 , 7 , etc.) and conducting ( 8 , 9 , 10 , etc.) plates similar in structure to ion funnels. In this case the internal opening of the lens system is cylindrical, with a diameter typically smaller than 3 mm. The successive metallic plates are separated from each other by distances varying from less than one mm up to several mm and are charged to time varying voltages of equal or similar magnitude and waveform, but different phases. Typically the phase difference may be 180 degrees, but 120 degrees or other values may also be used, and have in fact been used in the past in related designs (Hutchins et al. 1991). In the common case relying a phase difference of 180 degrees, plates 5 , 6 and 7 would be charged to periodically varying voltages V, −V, and V, respectively. The system just described based on U.S. Pat. No. 6,107,628 has one more advantage over multipole systems. In addition to the fact that it is naturally closed on the sides, it is now easier to impose axial electric fields by superposing to the RF potential an axial progression of a DC potential. This feature has been amply exploited in the past in low pressure designs. For our intended high pressure use, it offers the additional possibility of permitting the use of counterflow gas through the lens, going in a direction opposite to that of the ions. A third embodiment of the invention ( FIG. 4 ) is suggested by the work of Hutchins et al. (1991), where the series of perforated plates in the second embodiment is substituted by two or more coiled wires (11, 12) charged at different phases. Each of the wires is displaced by a fixed distance along the axis of the coil from the preceding and subsequent wire. Therefore, in the vicinity of each point along the wires, the field is similar to that in the lenses of U.S. Pat. No. 6,107,628, consisting of a spatially modulated field along the length. This local similarity of fields is greater when there are only two coiled wires charged at voltages 180 degrees apart from each other. In the coiled design of Hutchins et al. (1991) there is an additional effect associated not only with the rotation of the field during each period, but also to its axial advance. The electric field waves in the coiled design therefore are not strictly standing waves, but can be viewed as rotating and axially propagating (helicoidal) waves. In this sense, they should be expected to aid in the axial movement of the ions, in crude analogy to the traveling wave system used commercially by Waters in the Synapt mass spectrometer. This traveling wave feature is of some practical interest in the Hutchins lenses, which cannot implement axial fields as effectively as the Smith design. The main effect of the RF field is nonetheless similar in the Hutchins and the Smith designs, consisting primarily of a net repulsive force pushing the ions away from the walls, towards the axis of the lens system. The axial progression of the wave during one period becomes more evident as the phase difference between neighboring coils decreases below 180 degrees. The Hutchins design in fact used three coils with 120 degrees of phase difference. The Hutchins coils were also of decreasing cross section, similarly to the Smith funnels. FIGS. 2 , 3 and 4 show embodiments of our own lenses with an axially uniform cross section, although our invention includes also tapered designs. FIG. 4 is drawn for simplicity for two coils and a phase difference of 180 degrees, but other alternatives with three or more coils per axial period are also included in the invention. Also, for simplicity, FIG. 4 does not show the walls required to close the lens system laterally, forcing axial progression of the ions carried by the fluid. In one embodiment of the invention using the coiled wires, this lateral enclosure is cylindrical and contains coiled grooves meant to lodge the outer region of the wires and fix precisely their pitch. Another embodiment of the invention is meant to ionize vapors with efficiencies higher than conventionally achievable with an unipolar source of ions or charged drops, such as an electrospray source or a corona discharge. In this system, a gas containing the vapors one wishes to ionize bathes the interior of the RF lens. The entrance region to the lens is exposed to a source of charging ions, such as an electrospray source or an electrical discharge, so that these charging ions enter into the RF lens, and fill it at high volumetric charge densities and over very wide axial lengths, both much larger than normally permitted by space charge fields. The vapor is then exposed to an unconventionally large density of charging ions or drops over an unconventionally long time, and is furthermore focused into the axial region of the quadrupole. Hence, an unusually large fraction of the neutral vapor species present in the ambient may be charged and sampled at the exit of the RF lens into an analytical instrument such as a mass spectrometer or a differential mobility analyzer. Any of the three lens systems discussed previously for ion focusing purposes, and their many variants, could similarly be used for this vapor charging application.
Variants of these devices using ion sources other than electrospray, or analyzers other than mass spectrometers, or RF lens systems other than linear multipoles, funnels or helical wires are also included in this invention.
Relation to Prior Ion Guiding Systems
All previous art for ion (rather than microscopic particle) focusing has involved a focusing stage at pressures considerably lower than atmospheric. Although the proposed arrangement of lenses is similar for atmospheric and for reduced pressure operation, there is, however, a crucial difference not only in the state of the background gas, but also in the manner in which the ions to be concentrated are introduced into the focusing region. In traditional low-pressure ion guide systems, the ions are generally conveyed to the focusing region by a highly supersonic jet of gas. This is not the case in the present invention. In one possible embodiment, the gas could actually flow in the direction contrary to that used in traditional RF lenses, and the ions would be conveyed by the electric field without assistance of the flow field. In an alternative embodiment discussed, a flow of gas aids the electric field in transporting the ions into the focusing region, but the background gas is moderately supersonic, transonic or even low subsonic rather than having conventional highly supersonic speeds.
These considerations are not intended to imply that the present invention includes only subsonic gas flows. One can in fact consider situations where some of the embodiments discussed would involve speeds larger than the speed of sound, where the ratio of pressures would be moderate. In contrast, prior art has used pressure ratios typically between 760 and 0.1 torr, and in all cases larger than 760/20 torr. The current invention therefore encompasses situations where the ratio of pressures between the ion source and the focusing region does not exceed 20.
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The present invention is based on the observation that radio frequency (RF) electric fields in multi-pole lenses with small rod diameters in the range of 1 mm enables strongly concentrating ions suspended in a gas at pressures much higher than previously used for ion manipulation, including atmospheric pressure. Other lens configurations are described, including one based on the funnels of U.S. Pat. No. 6,107,628, and another on the coiled wire system of Hutchins et al. (1999). The finding provides a method to increase the concentration of ions transmitted to mass spectrometers and other analyzers, both from volatile or involatile species in solution, hence increasing their analytical sensitivity. It also enables improved charging efficiencies of neutral volatile species existing in the gas phase.
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TECHNICAL FIELD
The present invention relates generally to the art of cleaning workpieces such as semiconductor wafers during various stages in the manufacturing process of integrated circuits, and more particularly, relates to an improved method and apparatus whereby a freely rotating wafer is cleaned between two adjacent motor driven brushes wherein there is a substantially uniform relative velocity distribution between the top brush and the wafer's surface.
BACKGROUND OF THE INVENTION
A flat disk or “wafer” of single crystal silicon is the basic substrate material in the semiconductor industry for the manufacture of integrated circuits. Semiconductor wafers are typically created by growing an elongated cylinder or boule of single crystal silicon and then slicing individual wafers from the cylinder.
Several of the processes used to manufacture semiconductor wafers introduce particles or contaminates to the surfaces of the wafer. For example, chemical-mechanical polishing (CMP) involves placing the wafer on a polishing pad in the presence of slurry. Slurry typically contains chemicals that etch away material from the wafer's surface and abrasive particles that assist in mechanically removing material from the wafer's surface. Slurry may contain, for example, KOH and colloidal or fumed silica abrasive particles. The wafer is then pressed against the polishing pad and relative motion is created between the wafer's surface and the polishing pad to remove material from the wafer's surface. The wafer's surface is thereby exposed not only to the chemicals and particles contained in the slurry, but also to material removed from the wafer's surface. The process of pressing and causing relative motion between the wafer's surface and these contaminates undesirably adheres the contaminates to the wafer's surface.
The wafer's surface on which integrated circuitry is to be constructed must be extremely clean in order to facilitate reliable semiconductor junctions with subsequent layers of material applied to the wafer. The material layers (deposited thin film layers, usually made of metals for conductors or oxides for insulators) applied to the wafer while building interconnects for the integrated circuitry must also be made extremely clean to avoid contamination of the circuitry.
Conventional post-CMP wafer cleaning commonly uses a combination of buffing, double-sided brush scrubbing, megasonic cleaning and spin-rinse drying to remove contaminates from the wafer's surface. The present invention relates to double-sided brush scrubbing so buffing, megasonic cleaning and spin-rinse drying, all presently known cleaning techniques, will not be explained in detail so as to not obscure the present invention.
One conventional style of double-sided brush scrubbing is accomplished by placing a freely rotating wafer between the working surfaces of a top and a bottom brush. In conventional cleaning, the top and bottom brushes are rotated by a motor in the same direction and at the same speeds and have the same pattern of raised features on their working surfaces. The motorized rotating top and bottom brushes grip the edge of the freely rotating wafer and cause the wafer to also rotate in the same direction as the brushes.
Applicant has discovered that in conventional cleaners the top brush commonly rotates at about twice the speed of the wafer resulting in a nonuniform relative velocity between the top brush and the wafer across the wafer's surface. The consequences of applicant's discovery are graphically illustrated in FIGS. 2 a and 2 b . The velocities at various points across the rotating wafer 100 and rotating top brush 101 are represented by the arrows between lines C 2 and C 3 and lines C 1 and C 3 respectively. The line C 1 representing the speed of top brush 101 is steeper than the line C 2 representing the speed of the wafer 100 since, as previously mentioned, the top brush 101 commonly rotates at about twice the speed of the wafer 100 . The relative velocity between the top brush 101 and the wafer 100 may be found by subtracting their individual velocities at various points. The relative velocity between the top brush 101 and the wafer 100 is illustrated in FIG. 2 b . Specifically, applicant has discovered that as the wafer 100 rotates in a conventional dual brush cleaning system, the relative velocity between the top brush 101 and the wafer 100 is higher near the center and lower near the edge of the wafer 100 .
Applicant has further discovered that conventional dual brush cleaning systems typically remove particles satisfactorily from the center of the wafer 100 , but often leave a band of contaminates near the edge of the wafer 100 . Applicant has thus discovered a need for a dual brush cleaning system with a high uniform (across the entire width of the wafer 100 ) relative velocity between the top brush 101 and the wafer 100 .
What is therefore needed is an apparatus and method of cleaning wafers that produce a high uniform relative velocity between the top brush and the wafer's surface.
SUMMARY OF THE INVENTION
Therefore it is an object of the present invention to provide an apparatus and method for cleaning workpieces that addresses and resolves the shortcomings of the prior art described above. Another object of the present invention is to provide a dual brush cleaning system where all points on the workpiece's surface experience substantially similar top brush velocities during the cleaning process as the workpiece rotates between the brushes.
The apparatus portion of the present invention relates to a dual brush cleaning system for cleaning a workpiece's surface. The cleaning system has two brushes, a top and a bottom, each with a working surface on one end and is advantageously connected to a shaft on the other end. The working surfaces are positioned opposite of each other and spaced apart enough for a workpiece to be placed, gripped and cleaned between them. The shafts for both brushes may be connected to means, such as one or more motors, for rotating the brushes at separate speeds.
The apparatus is preferably able to create the condition of providing a uniform relative velocity between the top brush and the workpiece across the width of the workpiece as the workpiece rotates between the brushes. Sensors may be inserted to monitor in real-time the rotational speeds of the top brush and the workpiece and to then adjust the speed of the bottom brush as needed. However, the cleaning system may be simplified by determining through empirical means the bottom brush speed necessary to obtain a uniform relative velocity between the top brush and the workpiece. Once the desired bottom brush speed has been determined that produces the desired results for a particular application, the bottom brush speed may simply be set at this level.
While the top brush is used primarily to clean the workpiece's top surface, the bottom brush is used primarily (although it also cleans the workpiece's bottom surface) to rotate the workpiece. It is thus important for the working surface of the bottom brush to have an efficient grip on the workpiece to more efficiently rotate the workpiece. Applicant has discovered that a bottom brush with a plurality of nubbs (raised areas) on its working surface may be used to efficiently grip the workpiece and provide the necessary rotational motion to the workpiece.
The method portion of the present invention may be practiced in a dual brush cleaning system by inserting a workpiece, preferably a semiconductor wafer, between the working surfaces of a top and bottom brush. The brushes may be rotated after the workpiece has been inserted, but are preferably already rotating at the speeds necessary to produce a substantially uniform relative velocity between the top brush's working surface and the workpiece's surface.
These and other aspects of the present invention are described in full detail in the following description, claims and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals denote like elements, and:
FIG. 1 a is a top view of a dual brush cleaning system;
FIG. 1 b is a side view of the dual brush cleaning system shown in FIG. 1 a;
FIG. 2 a is a top view of a dual brush cleaning system illustrating the velocity of the workpiece and the velocity of the top brush when the top and bottom brushes rotate at the same speed;
FIG. 2 b is a top view of a dual brush cleaning system illustrating the relative velocity of the workpiece and the top brush when the top and bottom brushes rotate at the same speed as in FIG. 2 a;
FIG. 3 a is a top view of a dual brush cleaning system illustrating the condition of the bottom brush rotating at a speed faster than the speed of the top brush such that the top brush and workpiece rotate at the same speed;
FIG. 3 b is a top view of a dual brush cleaning system illustrating the relative velocity of the workpiece and the top brush when the top brush and workpiece rotate at the same speed as in FIG. 1 a;
FIG. 4 a is a bottom view of a preferred working surface for the top brush;
FIG. 4 b is a top view of a preferred working surface for the bottom brush; and
FIG. 5 is a flowchart of a preferred method for implementing the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Wafers are often exposed to contaminates during the manufacturing process of integrated circuits. For example, during CMP a wafer is typically pressed against a polishing surface in the presence of chemicals for etching the wafer's surface and abrasive particles for mechanical removing material from the wafer's surface. CMP is thus a particularly dirty process requiring wafers to be cleaned prior to being sent to the next manufacturing step.
A buffing step may be used after CMP to remove the gross contaminates as well as to remove any microscratches present on the wafer's surface. Buffing may be accomplished by lightly pressing, about 1.5 psi, a wafer's surface against a politex pad, made commercially available by Rodel Incorporated from Newark Delaware, in the presence of KOH, mild slurry and/or DI water. The present invention does not require any particular buffing process, but superior cleaning results may be obtained if an effective buffing step is used to remove the gross contaminates prior to the cleaning step.
Referring to FIGS. 1 a and 1 b , the components of an exemplary dual brush cleaning system necessary to practice the present invention will now be discussed in greater detail. The cleaning system has at least two brushes, a top 101 and a bottom 103 , each with a working surface on one end and, preferably, a shaft, 102 and 104 , connected to the other end. The brushes 101 and 103 may be advantageously made of compressible, porous polyvinyl alcohol (PVA) foam that becomes soft when wet. The brushes 101 and 103 may be disk-shaped with a diameter slightly larger than the radius of the wafer 100 . For example, the brushes 101 and 103 preferably have a diameter of about 128 mm for a wafer 100 having a diameter of 200 mm. Syntak Corporation and Rippey Corporation make PVA brushes commercially available that are suitable for practicing the present invention with semiconductor wafers.
The working surfaces of the brushes 101 and 103 are positioned facing each other and close enough so that a wafer 100 placed between the brushes 101 and 103 slightly compresses and makes strong friction engagement with the brushes 101 and 103 . The brushes during operation are preferably kept wet to keep the brushes soft and pliant to prevent them from damaging the wafer 100 and to suspend and carry away contaminates that have been liberated from the surface of the wafer 100 . For semiconductor wafers, the fluids should primarily comprise DI water, but may also have about 2% NH 4 OH by volume.
The shafts 102 and 104 for both brushes 101 and 103 may be connected to means, such as one or more motors 105 and 106 , for rotating the brushes 101 and 103 at separate speeds. Another alternative is to connect the motor(s) 105 directly to the brushes, for example, by a belt encircling the brushes 101 and 103 . A single motor with gearing mechanisms (not shown) for rotating the brushes 101 and 103 at separate speeds may be used, but preferably both brushes 101 and 103 have an independently controlled motor. The type of motor(s) 105 and 106 is not critical for the present invention, but it is desirable that the motor(s) produce few particles or contaminates. The motor(s) 105 and 106 must also be able to rotate the brushes 101 and 103 at the necessary speeds (typically between 50 and 500 rpm or more) to practice the present invention.
The dual brush cleaning system is advantageously able to create the condition of providing a uniform relative velocity between the top brush 101 and the wafer 100 across the width of the wafer 100 as the wafer 100 rotates between the brushes 101 and 103 . This desirable uniform velocity condition is illustrated in FIGS. 3 a and 3 b . The velocities at various points across the rotating wafer 100 and rotating top brush 101 are represented by arrows between lines A 2 and A 3 and lines A 1 and A 3 respectively. The line A 1 representing the speed of the top brush 101 has the same slope as line A 2 representing the speed of the wafer 100 since a uniform velocity condition may be created when the top brush 101 rotates at the same speed as the wafer 100 . The relative velocity between the top brush 101 and the wafer 100 may be found by subtracting their individual velocities at various points. The relative velocity between the top brush 101 and the wafer 100 when both are rotated at the same rpm is illustrated in FIG. 3 b . Specifically, Applicant has discovered that when the wafer 100 rotates at the same velocity as the top brush 101 , a desirable uniform relative velocity condition is created between the top brush 101 and the wafer 100 across the entire surface of the wafer 100 .
The cleaning step of removing contaminates from the wafer's surface relies heavily on mechanical forces, such as those resulting from brush 101 (and brush 103 for the back wafer's surface) contact with contaminates. These forces are determined by the number of brush-particle collisions and the brush-wafer relative speed at the time of the collision. As the number of collisions and the relative speed increases, the opportunities for particle removal also increase. Thus, the length of time the wafer 100 spends between the rotating brushes 101 and 103 , the brush pressure against the wafer 100 and the brush rotating speed are all critical in obtaining the best possible cleaning result. In general, the longer the brushing time, the greater the brush pressure and the faster the brush rotating speed, the better the cleaning result. Specifically, a wafer cleaning time of about 80 seconds between a top brush 101 rotating at about 110 rpm and a bottom brush rotating at about 300 rpm with a brush pressure of 3.5 psi has been found to produce acceptable results. These process parameters for PVA brushes 101 and 103 having a diameter of 128 mm, in combination with the brush contours discussed below, have been found to rotate a 200 mm wafer 100 at the same speed as the top brush 101 , i.e., 110 rpm.
Sensors may be inserted to monitor in real-time the rotational speeds of the top brush 101 and the wafer 100 and to then adjust the speed of the bottom brush 103 as needed. However, the cleaning system may be simplified by determining through empirical means the bottom brush speed necessary to obtain a uniform relative velocity between the top brush 101 and the wafer 100 . Once the desired bottom brush speed has been determined that produces the desired results for a particular application, the bottom brush speed may simply be set to this level.
Referring to FIGS. 4 a and 4 b , while the top brush 101 is used primarily to clean the wafer's top surface, the bottom brush 103 is used primarily (although it also cleans the wafer's bottom surface) to rotate the wafer 100 . It is thus important for the working surface of the bottom brush 103 to have an efficient grip on the wafer 100 to properly rotate the wafer 100 . A bottom brush 103 with a plurality of round-shaped nodules (nubbs) 108 separated by open spaces on its working surface have been found to efficiently grip the wafer 100 and provide the necessary rotational motion to the wafer 100 . A top brush 101 with a plurality of raised wipers 107 separated by open spaces has been found to efficiently remove contaminates on the wafer's surface.
An exemplary method of the present invention for cleaning a wafer 100 will now be discussed with reference to the apparatus in FIGS. 1 a and 1 b and the process flowchart in FIG. 5 . After CMP and a buffing step, or other process steps that leave contaminates on the wafer's surface, a wafer 100 may be cleaned in a dual brush cleaning system such as that described above. The PVA brushes 101 and 103 may be kept compliant and contaminates transported away by continually rinsing the brushes 101 and 103 with DI water and, optionally, 2% NH 4 OH by volume (step 501 ). The brushes 101 and 103 preferably have been previously positioned opposite of each other such that a wafer 100 inserted between their working surfaces would be under about 1.0 psi. The top brush 101 may be rotated at a first speed (step 502 ) while the bottom brush 103 may be rotated in the same direction at a second faster speed (step 503 ) that results in the wafer 100 rotating at the same speed as the top brush 101 . Specifically, a top brush rotation speed of about 110 rpm and a bottom brush rotation speed of about 300 rpm have been found to produce the desired condition of a uniform relative velocity between the top brush 101 and the wafer 100 . A wafer 100 may be inserted between the top brush 101 and the bottom brush 103 for a period of time, up to 80 seconds or even longer, to produce the desired level of cleanliness (step 505 ). The wafer may then be withdrawn from between the top brush 101 and the bottom brush 103 (step 506 ).
The wafer 100 is preferably then dried with remaining loose contaminates removed from the surface. This may be accomplished by rinsing the wafer with DI water and then spinning the wafer (preferably at a speed faster than 1000 rpm) in a spin-rinse dryer (not shown) to remove any remaining fluids and contaminates on the surface by centrifugal force.
Although the foregoing description sets forth a preferred exemplary embodiment and method of operation of the invention, the scope of the invention is not limited to this specific embodiment or described method of operation. Modification may be made to the specific form and design of the invention without departing from its spirit and scope as expressed in the following claims. For example, although the present invention was described using a wafer 100 as the described workpiece, any number of workpieces may also be cleaned using the present invention.
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A method and apparatus for cleaning a wafer in a dual brush cleaning system is disclosed. Two brushes, preferably made of PVA and wetted by cleaning fluids, are positioned opposite one another and spaced apart enough to allow a portion of a wafer to be inserted between their working surfaces and make frictional engagement with them. The top brush is rotated at a first speed and the bottom brush is rotated at a second faster speed sufficient for the freely rotating wafer to rotate at the same speed and in the same direction as the top brush. The bottom brush may have raised areas on its surface to assist in efficiently gripping and rotating the wafer. A common rotation speed and direction causes a uniform relative velocity between the top brush and the wafer that results in an improved cleaning operation.
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BACKGROUND OF THE INVENTION
Immunoassays have been used routinely for the identification and quantitation of haptens, antigens and antibodies (all broadly termed analytes). The basic principle of all immunoassays is predicated on the specific binding between components of a reaction pair (e.g. antigen/antibody, hapten/antibody, etc.) where, in some cases, one component is labeled in such a fashion as to be easily analyzed by some external means.
Radioimmunoassay (RIA) is based on the use of a radioisotope as a label for one of the components of a specific binding pair. A radioisotopically labeled component can then be detected by counting the radiation emitted by the isotope using a suitable instrument.
Other methods of labeling one component of a specific binding pair have been developed. The use of enzyme and fluorescent labels have recently been employed and are termed enzyme immunoassay (EIA) and fluorescent immunoassay (FIA) respectively. Again, with the use of suitable reagents and instruments, these labels can be used for the determination of analytes in a liquid medium. Many variations to the basic procedures are in use, but most require the steps of reaction, separation, and detection of label.
More recently, electrochemical sensors have been employed in an effort to simplify and/or improve the sensitivity of these procedures. Basically, they employ an ion selective electrode to detect the reaction product of an enzyme which has been used as a label for one component of a specific binding pair.
The present invention seeks to eliminate the preparation of a labeled component of a specific binding pair, the separation of such a component from the assay system, as well as its subsequent detection; thereby greatly simplifying the method of performing an immunoassay. More specifically, the present invention relates to a new and useful improvement in a method for the determination of analytes in a liquid medium by the use of a biochemically sensitive semiconductor device set forth in the following description and specifications.
DESCRIPTION OF THE INVENTION
All numbers in parenthesis refer to elements in FIGS. 1 and 2.
The present invention relates to a device to be used in a method for the determination of analytes in a liquid medium. More specifically, the present invention relates to a device, composed of an electrically semiconductive material (1) to which an analyte specific binding substance (2) is suitably immobilized to said material in such a fashion that the binding of said analyte (3) to its specific binding substance alters the electrical semiconductive properties in a measureable way. Further, the present invention relates to a method of determining the presence of an analyte in a liquid medium using such a device.
As most specific binding substances for any particular analyte are biological in origin, said device is termed a biochemically sensitive semiconductor device or BSSD. These specific binding substances are generally of an organic chemical nature, displaying certain measureable properties of which one is a specific electrical charge. Furthermore, for a specific binding substance, its electrical charge will vary as a result of its binding to its particular analyte; an example of a binding substance and its specific analyte is an antibody and its specific antigen. Examples of specific binding substances are: antibodies, antigens, enzymes, enzyme substrates, enzyme substrate analogs, agglutinins, lectins, enzyme cofactors, enzyme inhibitors and hormones. This invention seeks to detect and measure the binding of an antigen (analyte) by its specific antibody (binding substance) by detecting and measuring the change in the electrical charge of one or both elements of the binding reaction. By placing either one of the two elements of a specific binding system in close proximity to a material which can be influenced by the field of the electrical charge, a change in that electrical field as a result of the binding reaction will effect a change in the properties of that material. If the properties of this material are measureable, it follows that the binding reaction is also measureable.
A class of materials which can be used to satisfy the aforementioned description are known as semiconductors. These materials display electrical characteristics between that of a good electrical conductor, such as copper, and a good electrical insulator, such as glass; hence the term "semiconductor". The properties of a material that provide for its semiconductive characteristics depend on the number of electrons in that material available to move freely through such a material under the influence of an externally applied electric field. All materials are composed of atoms, themselves further comprised of various particles, one of which is termed an electron. An electron is by definition one unit of negative electrical charge. Thus, while all materials are comprised, in part, of electrons, not all electrons are available to move freely through such a material under the influence of an externally applied electric field; these electrons are termed valence electrons and are tightly held to its atom by various nuclear and electrical forces. Those electrons which can move freely through a material, thus conducting electricity, are said to be in a conductive band.
A semiconductive material contains conductive and valence electrons, either naturally or by design. Silicon, for example, can be "doped" with various elements to create either an excess of electrons, or a scarcity of electrons, also termed "holes". Furthermore, such semiconductive materials can exhibit either an increase or a decrease in electrical conductivity, as a result of an increase or decrease in the number of electrons in the conduction band. Such an effect may be obtained by the application of an externally applied electric field to the semiconductor which supplies sufficient energy for a number of valence electrons to enter the conduction band and thus become available to conduct electricity through the material. The energy to promote an electron from the valence band to the conduction band is termed the Fermi energy level. This description explains the basis for the operation of a field effect transistor.
SUMMARY OF THE PRESENT INVENTION
The present invention makes use of this semiconductive phenomenon by utilizing the electrical characteristics of a specific binding substance, such as an antibody molecule, to influence the conductivity state of a semiconductor; thus by measuring the conductivity of said semiconductor, one can determine the binding of an analyte by its specific binding substance as a result of the change in its electrical characteristics and the resultant change in its influence on the semiconductor.
The preferred embodiment utilizes a semiconductive organic polymer, known as polyacetylene. Polyacetylene, having the general chemical formula (CH) x , displays semiconductive properties in part as a result of extensive, alternating conjugated pi bonding orbitals of the carbon-carbon bonds. In conjunction with a specific binding substance, the semiconductive properties can be altered in a measureable fashion to effect the principle of the present invention.
The term "analyte" as used herein refers to antigens, antibodies, haptens, enzymes and enzyme substrates. The term "specific binding substance" is any substance or group of substances having a specific binding affinity for the analyte to the exclusion of other substances.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing the semiconductive sensor in its electrical measurement circuit;
FIG. 2 is a representation of the semiconductive sensor.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The following specific description is given to enable those skilled in the art to more clearly understand and practice the present invention. It should not be considered as a limitation upon the scope of the invention but merely as being illustrative and representative thereof.
Preparation A
The IgG fraction of goat anti-rabbit IgG serum was isolated by a combination of 33% ammonium sulfate precipitation and DEAE cellulose chromatography as described by Garvey, J. S. et al. (1970) in Methods in Immunology, pp. 193-198, W. A. Benjamin Inc. Further specific purification, as necessary, was effected by the technique of affinity chromatography, various procedures of which are described in the literature.
Preparation B
The trans-polymer of acetylene was prepared, using a Zeigler-type catalyst, following the procedure of Ito et al., Journal of Polymer Science, 12,11, (1974).
EXAMPLE I
Strips of freshly synthesized polyacetylene, approximately 4×20 mm, were placed in a 0.05 M carbonate-bicarbonate buffer, pH 9.5 containing 5 mg/ml of purified goat anti-rabbit IgG and incubated overnight at room temperature. The polyacetylene-antibody strips were subsequently washed with a saline solution and stored under nitrogen.
The polyacetylene-antibody strips (1) were mounted on a teflon block (7) using two conductive gold clamps (8) to secure the strip in place and provide for two electrical connections spaced 5 mm apart. This resulting two port device was connected to a Wheatstone bridge (4) which was connected to a variable voltage, direct current, power supply. The voltage difference in the Wheatstone bridge network was amplified by a differential amplifier (5) which was connected to a suitable voltmeter (6), as the first step voltage is applied to the Wheatstone bridge and that network adjusted to provide a suitable "null" reading on the voltmeter. Then, 10 μl of a suitable dilution of a purified IgG fraction of rabbit serum is placed on the antibody-polyacetylene strip while recording the reading on the voltmeter as a function of time. The amplified change in voltage with time reflected the kinetic aspects of the antigen-antibody binding reaction. When the voltmeter reading stabilized (after 3 to 10 minutes), the Wheatstone bridge circuit was readjusted to the initial null reading with a suitably calibrated potentiometer.
Variations on the above procedure were made in order to obtain the desired results and to rule out effects resulting from other variables not related specifically to the antigen-antibody binding reaction. Those variations include differences in applied voltage, degree of amplification, and the extent of dilution required for the rabbit IgG solution. To further rule out non-specific effects, two polyacetylene-antibody devices were connected in the Wheatstone bridge circuit and electrically balanced. The experiment was repeated with one device receiving the diluent (saline), not containing the rabbit IgG. From this example, various concentrations of rabbit IgG produced predictable changes in the conductivity of the polyacetylene-antibody film.
EXAMPLE II
As in Example I, a strip of polyacetylene-antibody was prepared, using a goat anti-rabbit IgG preparation, and placed in a teflon holder. A mesh with a 3 mm diameter cutout was placed over the polyacetylene film and used to overlay an aqueous gelatin film, taking the precaution not to physically or electrically connect the two conductive clamps with the gelatin film. A measurement of the specific analyte was made with this device as described in Example I.
EXAMPLE III
As in Example II, a strip of polyacetylene-antibody-gelatin film was prepared except that a third electrical connection was formed by placing a piece of platinum wire (10) just on the surface of the gelatin film. In this example, the device is similar in principle to a field effect transistor. This third electrical connection allows for the application of an electrical potential at a right angle to the flow of electrons through the polyacetylene-antibody film. Using this device, the binding of rabbit IgG to goat anti-rabbit IgG antibody was ascertained as described in Examples I and II.
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 are to be included within the scope of the following claims.
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A method, sensor and semiconductor device for determining the concentration of an analyte in a medium. The device features an element constructed of polyacetylene associated with a binding substance having specific affinity for the analyte.
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FIELD OF THE INVENTION
The present invention relates to an optical lens, and more particularly, relates to a secondary light distribution lens for multi-chip semiconductor (LED) lighting.
BACKGROUND OF THE INVENTION
The secondary light distribution lens for most of current LEDs are mainly smooth total reflection lens, the basic structure of which lies in that a smooth aspherical lens for converging light is positioned on top of a concave portion in the centre area, around which a smooth total reflection face is disposed. This lens mainly applies to the light distribution of a single-chip LED, which represents a circular and efficient light spot distribution. However, regarding the multi-chip LED, this lens may project such a light spot that forms square or petaline chip shadow due to image of the chip formed by the central aspherical face.
SUMMARY OF THE INVENTION
In view of the disadvantage of the current total reflection lens, the present invention proposed a lens comprising: (a) a lens body; (b) a total reflection surface provided on an outer side of the lens body, the reflection surface being in the form of a scalelike polyhedron; (c) a recess formed on a bottom side of the lens body at a central region thereof for accommodating a LED, the recess having a side surface and a central surface; a micro lens array formed at the central surface of the recess; and (e) a light-emitting surface provided at a top side of the lens body; wherein a substantially uniform circular light spot is formed by the lens.
The LED is single-chip or multi-chip, with different colors of red, green or blue.
The scalelike polyhedron comprises rhomboid, diamond, square or spiral surfaces.
The side surface of the recess is in the shape of a cylinder, a cone or a revolving arc.
The light-emitting surface comprises one or more planar and curved surfaces.
The light-emitting surface comprises a concave or convex spherical surface, an aspherical surface, a Fresnel surface, a pillow lens array, or a corrugated strip surface.
Each scale on the scalelike polyhedron of the reflection surface has a planar or arc curved surface.
The shape of micro lens array is circular, hexagonal, square, corrugated, or radiant in shape.
Preferably, a part of the light emitting from the LED and directing towards the side surface of the recess is refracted by the side surface, reflected by the reflection surface, and refracted by and emitted from the light-emitting surface, generating a light distribution with an angle ±θ (full beam angle of 2θ), where θ is 2° to 45°, and wherein the scalelike reflection surface is provided for breaking the boundary of light distribution, whereby every discrete scale generates a range of light distribution of its own, based upon which the superposition of the light distribution from a plurality of scales form a considerably uniform light spot distribution at certain angle.
Preferably, a part of light emitting from the LED and directing towards the central surface of the recess is refracted by the central surface, and refracted by and emitted from the light-emitting surface, generating a light distribution with an angle of ±θ, where θ is 2° to 45°, and wherein the micro lens array is provided for light blending.
Preferably, the light reflected from the light striking at the lowermost edge of the reflection surface is parallel to the optical axis after being transmitted from said light-emitting surface, the light reflected from the light striking at the uppermost edge of the reflection surface forms an angle θ with the optical axis after being transmitted from said light-emitting surface; and the light reflected from the light striking at the surfaces between the uppermost and the lowermost edges of the reflection surface forms an angle with the optical axis ranging from 0˜θ degrees according to certain ratio after being transmitted from said light-emitting surface.
The numerical aperture angle of each micro lens at the central surface of the recess is ±θ (full beam angle of 2θ) in combination with the light-emitting surface.
Preferably, the lens further comprises a flange provided along a rim at a front side of the lens body, and legs formed on the flange for fixing the position of the lens body.
Preferably, the rear side of the lens body is provided with a planar surface connecting the side surface of the recess and the reflection surface to facilitate the securing of the lens body to a base of the LED.
According to the light distribution solution of non-image-optics of the present invention, the light mixing theory is integrated into a secondary optical lens, and wherein light mixing is achieved by the micro lens array in the center area and a rhomboid, square or diamond scalelike polyhedron reflection face in the side, whereby the desired beam angle is achieved. With present invention, a considerably circular light spot may be formed with whatever chip arrangement, in which no shadow imaged by the chip shape can be found. The LED used with present invention may be single-chip or multi-chip, with different colors such as red, green and blue.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitutes a part of this specification, illustrate an implementation of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,
FIG. 1 is section view of the lens according to the specific embodiment 1;
FIG. 2 is view of lens of the specific embodiment 1, respectively showing the front view, the isometric view, the top view, the side view and the bottom view;
FIG. 3 is designing principle for the lens of specific embodiment 1;
FIG. 4 is light intensity far field angle distribution of the lens according to present embodiment when θ equals to 5°, 18°, 45°;
FIG. 5( a ) shows the computer simulation for the specific embodiment 1;
FIG. 5( b ) shows the light tracks of the lens according to the specific embodiment 1;
FIG. 6( a ) shows the light spot shape and illuminance distribution in the distance of 1 meter from the lens according to the specific embodiment 1;
FIG. 6( b ) is the contour illuminance chart of the lens according to the specific embodiment 1;
FIG. 7 is far-field angular distribution (light distribution curve) of the light intensity for the lens according to the specific embodiment 1;
FIG. 8 is a section view of the lens according to the specific embodiment 2;
FIG. 9 respectively shows the front view, the isometric view, the top view, the side view and the bottom view of the lens according to the specific embodiment 2;
FIG. 10 is designing principle for the lens according to the specific embodiment 2
FIG. 11( a ) shows the computer simulation for the specific embodiment 2;
FIG. 11( b ) shows the light tracks of the lens according to specific embodiment 2;
FIG. 12( a ) is light spot shape and illuminance distribution in the distance of 1 meter from the lens according to the specific embodiment 2;
FIG. 12( b ) is the contour illuminance chart of the lens according to the specific embodiment 2;
FIG. 13 is far-field angular distribution (light distribution curve) of the light intensity for the lens according to the specific embodiment 2;
FIG. 14 respectively shows the front view, the isometric view, the top view, the side view and the bottom view of the lens according to the specific embodiment 3 with the reflection face on the outer side consisting of square scale;
FIG. 15 respectively shows the front view, the isometric view, the top view, the side view and the bottom view of the lens according to the specific embodiment 4 with a reflection face on the outer side consisting of spiral scale;
FIG. 16 shows the lens according to the specific embodiment 5 with a convex emitting face on top of the lens;
FIG. 17 shows the lens according to the specific embodiment 6 with a concave emitting face on top of the lens;
FIG. 18 shows the lens according to the specific embodiment 7 with a Fresnel emitting face on top of the lens;
FIG. 19 shows the lens according to the specific embodiment 8 with a emitting face of pillow lens array on top of the lens;
FIG. 20 shows the lens according to the specific embodiment 9 with a corrugated strip lens array on top of the lens.
DETAILED DESCRIPTION OF THE INVENTION
Specific Embodiment 1
A specific embodiment 1 of the secondary optical lens according to present invention is shown in FIG. 1 . A recess is positioned on bottom of the lens in the center area. The recess is used to arrange a multi-chip LED light source, the top portion 2 of which consists of plurality of micro lens (micro lens array). The shape of the micro lens array may be circular, hexagon, square, corrugated, radiant shape and the like irregular shapes. The side face 1 of the recess is a cylindrical, cone or arc revolution face. The secondary light distribution lens has a total reflection face 3 on the outer side, which consists of a rhomboid, diamond, square or spiral scalelike polyhedron; the top 4 of the lens is the emitting face, which may be one or more planes or curve faces, and which may be a concave or convex spherical face, aspherical face, Fresnel face, pillow lens array, corrugated strip face and the like free faces; the rim 5 on top of the lens is a flange for fixing, which does not function for optical effect, and which may present any shape, and which may have claws thereon to fix the position of the lens. The bottom 6 of the lens is a plane for connecting the side face 1 of the recess and the total reflection face 3 on the outer side, which does not function for optical effect, and which is provided for positioning the lens on the base of the LED.
FIG. 2 shows a view of the lens 3 of the specific embodiment 1 according to present invention. It shows that the total reflection face 3 on the outer side of the lens consists of a rhomboid, square or diamond scalelike polyhedron, preferably a diamond polyhedron, in which every small scale of the polyhedrons may be a plane or arc curved face. As the light distribution of a smooth reflection face to a incident light is continuous, a bright speck or a dark speck will be formed when the LED light source is a multi-chip LED, which results non-uniformity of the light spot distribution. The scalelike reflection face herein is provided for breaking the boundary of light distribution, whereby every discrete scale may generate a range of distribution on its own, based upon which the superposition of light distribution from a plurality of scales will form a considerably uniform light spot distribution in certain angle. Furthermore, the secondary optical lens has a recess on bottom of the lens in the center area, which is used to position the LED, and the top 2 of which consists of a micro lens array, which may effect light mixing for incident light from the LED, whereby a considerably uniform light distribution is formed in certain angle.
FIG. 3 shows the designing principle for the lens of specific embodiment 1. A part of the light emitting from the LED and directing to the side impacts on the total reflection face 3 on the outer side of the lens after passing the concave side face 1 , whereafter the reflection light emitting from the emitting face 4 on top of the lens generates a light distribution including an angle ±θ (full beam angle is 2θ). A part of light emitting from the LED and directing to the center emits from the emitting face 4 on top of the lens after passing the micro lens array on top of the recess, resulting a light distribution including an angle ±θ. The characteristic of the light distribution of the reflection face 3 on the outer side lies in that the reflection light from the edge light impacting on the lowest edge of the reflection face 3 forms an angle of zero degree with the optical axis OZ, i.e. parallel to the optical axis OZ; and that the reflection light from the edge light impacting on the topmost edge of the reflection face 3 , after emitting from the emitting face 4 , forms an angle θ with the optical axis; and that the reflection light from the light impacting on other places on the reflection face 3 , after emitting from the emitting face 4 , forms such an angle with the optical axis that distributes in the range of 0˜θ according to certain radio. The characteristic of the light distribution of the micro lens array on top of the recess disposed on bottom of the lens in the center area lies in that the numerical aperture angle of each micro lens is ±θ (full beam angle is 2θ) in combination with the emitting face 4 on top of the lens, and that the emitting light from a plurality of micro lenses superposes to form a uniform light distribution in the angle ±θ, whereby it effects light mixing for light from the LED. The lens used with present embodiment has a light distribution angle θ, which may be any degree from 2 degree to 45 degree (full beam angle 2θ is 4°˜90°), if necessary. FIG. 4 shows the light distribution curve of the lens according to present embodiment when the lens is a narrow beam, medium beam and broad beam lens, and when θ equals to 5°, 18°, 45° (full beam angle is 10°, 36°, 90°).
FIG. 5( a ) shows the computer simulation for the specific embodiment 1, wherein it assumes the light source of the LED is a CREE MT-G with 12 chips, the light flux of which LED is 380 Lumen, and wherein the lens thereof is designed according to a full beam angle of 36° (i.e. θ=18°). FIG. 5( b ) shows the light tracks of the lens. FIG. 6( a ) shows the light spot shape and illuminance distribution in the distance of 1 meter from the lens according to the specific embodiment 1; FIG. 6( b ) is the contour illuminance chart of the lens according to the specific embodiment 1, in which the light spot presents a circular shape and no square or petaline shadow formed by projection due to the arrangement of the chips are found. FIG. 7 shows the far-field angular distribution (light distribution curve) of the lens, in which the light beam angle is ±18° at the location of half light intensity. The theoretical efficiency of the lens by simulation is 97.827%. If it is assumed that the luminousness of the lens material is 92%, then the optical efficiency of the lens produced may reach to 90%.
Specific Embodiment 2
The section view for the specific embodiment 2 of the secondary optical lens according to present invention is shown in FIG. 8 . The emitting face on top of the lens as shown is divided into 2 portions 24 a and 24 b , wherein 24 a presents a convex aspherical face, and 24 b presents a revolution face with a arc generating line. A recess is disposed on bottom of the lens in the center area, the top 22 of which consists of micro lens array, and the side face 21 of which presents a cylindrical, cone or revolution face, preferably a revolution face with a arc generating line. The reflection face on the outer side may also consist of a rhomboid, diamond, square or spiral scalelike polyhedron, preferably a square scalelike polyhedron. The rim 25 on top of the lens is a cylindrical face for fixing, which does not function for optical effect, and which may have claws on its outer side to fix the position of the lens. The bottom 6 of the lens is a plane for connecting the side face 21 of the recess and the total reflection face 23 on the outer side, which does not function for optical effect.
The orthographic views for the specific embodiment 2 of the secondary optical lens according to present invention is shown in FIG. 9 . It is seen from the bottom view that a recess is disposed on bottom of the lens in the center area, the top 22 of which consists of a micro lens array, in which the shape of the micro lens array may be a circular, hexagon, square, corrugated, radiant shape and the like irregular shapes, preferably a radiant shape.
FIG. 10 shows the designing principle for the lens according to the specific embodiment 2 in accordance with present invention. The lens is a narrow angle lens, for which the light distribution of the lens may be designed according to a collimated light beam. A part of the light emitting from the LED and directing to the side impact on the scalelike total reflection face 23 on the outer side after passing the side face 22 of the recess. The reflection light from the total reflection face 23 emits collimatly after passing the emitting face 24 b on top of the lens at the outer circle. A part of light emitting from the LED and directing to the center area emits collimatly from the emitting face 24 a on top of the lens after passing the micro lens array on top 22 of the recess. As an additional light distribution curve face 24 a disposed on top of the lens, which brings one additional freedom for light distribution design, a narrow light beam angle for the lens may be achieved in accordance with such structure with respect to a multi-chip LED light source. Naturally, a lens with a broad light beam angle may be achieved in accordance with present embodiment, as long as that the reflection face 23 on the outer circle together with the emitting face 24 b are configured to have a light distribution of angle ±θ. Similarly, it is necessary that the micro lens array on top 22 of the recess disposed on bottom of the lens together with the emitting face 24 a forms a numerical aperture of angle θ.
FIG. 11( a ) shows the computer simulation for present embodiment, in which it is assumed that the LED light source is a CREE MT-G with 12 chips, the light flux of which LED is 380 Lumen, wherein the lens is a narrow angle lens designed according to collimated light. FIG. 11( b ) shows the light tracks of the lens according to specific embodiment 2.
FIG. 12( a ) is light spot shape and illuminance distribution in the distance of 1 meter from the lens according to the specific embodiment 2; and FIG. 12( b ) is the contour illuminance chart of the lens according to the specific embodiment 2, in which the light spot presents a circular shape and no square or petaline shadow formed by projection due to the arrangement of the chips are found. FIG. 13 shows the far-field angular distribution (light distribution curve) of the light intensity for the lens, in which the light beam angle is ±5° at the location of half light intensity. The theoretical efficiency of the lens by simulation is 98.252%. If it is assumed that the luminousness of the lens material is 92%, then the optical efficiency of the lens produced may reach to 90%.
Other Specific Embodiments
There are several other embodiments for the secondary optical lens according to present invention. FIG. 14 shows the specific embodiment 3 according to present invention, in which most of the structure is identical to the specific embodiment 1 except that the total reflection face 33 on the outer side of the lens consists of square scale. The present embodiment shares the same light beam angle, light spot shape and optical efficiency with the specific embodiment 1.
FIG. 15 shows the specific embodiment 14 according to present invention, in which most of the structure is identical to the specific embodiment 1 except that the total reflection face 43 on the outer side of the lens consists of spiral scale. The present embodiment shares the same light beam angle, light spot shape and optical efficiency with the specific embodiment 1.
FIG. 16 shows the specific embodiment 5 according to present invention. The lower part of the lens in present embodiment is identical to the specific embodiment 1, while the emitting face 54 on top of the lens is a convex face, which may be a spherical face, an aspherical face or free face. The convex emitting face may converge the emitting light at certain distance, forming a circular or other shaped converging light spot.
FIG. 17 shows the specific embodiment 6 according to present invention. The lower part of the lens in present embodiment is identical to the specific embodiment 1, while the emitting face 64 on top of the lens is a concave face, which may be a spherical face, an aspherical face or free face. The concave emitting face may diverge the emitting light, forming a circular or other shaped light spot with a comparative broad lighting range.
FIG. 18 shows the specific embodiment 7 according to present invention. The lower part of the lens in present embodiment is identical to the specific embodiment 1, while the emitting face 74 on top of the lens is a Fresnel face. The Fresnel face may uniformly distribute the emitting converging (or diverging) light, forming a more uniform light spot distribution.
FIG. 19 shows the specific embodiment 8 according to present invention. The lower part of the lens in present embodiment is identical to the specific embodiment 1, while the emitting face 84 on top of the lens is a pillow lens array. Since the pillow lens has different curvature radius in X and Y direction, which results the emitting light of the lens has the different light beam angles in the orthogonal X and Y directions. The present embodiment may emit a oblong light spot with different light beam angle in the X and Y direction that can be used in vehicle lighting and traffic lighting.
FIG. 20 shows the specific embodiment 9 according to present invention. The lower part of the lens in present embodiment is identical to the specific embodiment 1, while the emitting face 94 on top of the lens is a corrugated strip lens array, which may expand the emitting light beam in one direction and keep the emitting light beam collimated in the other direction. This embodiment may be used to provide such a light spot that the angle is narrow in one direction and broad in the other direction.
The foregoing description of an implementation of the invention has been presented for purpose of illustration and description. It is not exclusive and does not limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practicing the invention.
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A lens comprising: a lens body; a total reflection surface provided on an outer side of the lens body, the reflection surface being in the form of a scalelike polyhedron; a recess formed on a bottom side of the lens body at a central region thereof for accommodating a LED, the recess having a side surface and a central surface; a micro lens array formed at the central surface of the recess; and a light-emitting surface provided at a top side of the lens body; wherein a substantially uniform circular light spot is formed by the lens.
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This present application claims the benefit of U.S. Provisional Application Ser. No. 60/077,713, filed Mar. 12, 1998, entitled "Enhancement of the Pro-Fertility Action of a Molecule Involved in Sperm-Egg Binding."
BACKGROUND OF THE INVENTION
Related Applications
Subfertility is a major problem with domestic animals, humans and certain endangered species. Subfertility has a billion dollar impact on food production. In many circumstances, most sperm in a sample must have a low fertilizing potential despite normality of motion, morphology, or "viability" (plasma membrane excludes dye) . This is evidenced in two ways. First, attributes of each spermatozoan other than "motility" and "viability" are important, and failure in one of many critical functions renders a spermatozoan incapable of fertilizing an oocyte (Amann and Hammerstedt, 1993; Hammerstedt, 1996). An in vitro sperm-binding assay (Barbato et al., 1998; Amann et al., 1999) allows detection of certain males ejaculating semen with a relatively low percentage of sperm capable of binding in this assay and, hence, likely to be of low fertility. Fertility trials confirm general correctness of the classification (Barbato et al., 1998).
Knowledge of sperm-associated proteins is evolving rapidly, and it is evident that sperm are exposed to, and modified by, specific proteins secreted at multiple sites within the testis and/or excurrent duct system. As summarized by Amann et al. (1999), individual glycosylated molecules have received emphasis in considerations of sperm-to-egg binding, at the potential risk of overlooking non-glycosylated molecules. Also, some authors rightly have highlighted the need for multiple and synergistic ligands. Hammerstedt et al. (1997) disclosed a novel native protein and several non-glycosylated, synthetic peptides which, when included in buffer suspending sperm, increased the percentage of sperm bound using an in vitro assay and also increased fertility of sperm used for artificial insemination. The native peptide is thought to be formed from prosaposin.
Full-length, unprocessed prosaposin (Collard et al., 1988; O'Brien and Kishimoto, 1991; Kishimoto et al., 1992; Azuma et al., 1998) also has been termed sulfated glycoprotein 1 or SGP-1. Conventionally, prosaposin is proteolytically processed (Hiraiwa et al., 1993) into 4 saposins (A, B, C and D; each 13 to 15 kD) and 3 intervening segments (A-B, B-C and C-D; each 6 to 8 kD). Saposins are considered to be activator proteins increasing the catalytic rate of lipid-modifying enzymes, as in lysosomes (O'Brien and Kishimoto, 1991; Kishimoto et al., 1992; Mumford et al., 1995). Until Hammerstedt et al. (1997) , no function had been ascribed to any of the 3 intervening segments. Prosaposin (or mature products thereof) is produced throughout the body although not secreted by most tissues (Collard et al., 1988; Kishimoto et al., 1992; Sylvester et al., 1984, 1989; Igdoura et al., 1993; Rosenthal et al., 1995).
The antibody commonly used to localize prosaposin apparently binds an epitope(s) common to each of the 4 saposins (Igdoura et al., 1993; Igdoura and Morales, 1995) and, hence, also is bound by prosaposin. Based on probing of western blots with antibody, prosaposin (and traces of saposins) was found in luminal fluids in the excurrent ducts conveying sperm from the testes (Sylvester et al., 1989; Igdoura and Morales, 1995), but there was a complete absence of sperm-labeling throughout the excurrent ducts (Sylvester et al., 1989; Hermo et al., 1992).
The most favored synthetic peptides of Hammerstedt et al. (1997) are a sequence integral to a truncated portion of the rat or human prosaposin molecule extending from the cystine amino acid near the distal terminus of saposin A, through the intervening sequence between saposin A and saposin B., and through the proximal cystine amino acid in saposin B; a total of sixty (60) amino acids in rat or sixty-one (61) amino acids in human. Hammerstedt et al. (1997) further claim that maximum activity is obtained by linking the terminal cystine amino acids in most favored disclosed sequences by a disulfide bond, to provide a hairpin form.
SUMMARY OF THE INVENTION
In the course of advancing technology disclosed by Hammerstedt et al. (1997) we had reason to have chemically synthesized a novel sequence which: (1) departs from and adds to a prior art sequence of Hammerstedt et al. (1997) (SEQ ID NO: 4 herein) ; and (2) incorporates an amino acid sequence not found in the corresponding portion of the prosaposin molecule. This sequence is presented as SEQ ID NO: 1. The analogous new sequences in human and chicken prosaposin are presented as SEQ ID NO: 2 and SEQ ID NO: 3.
The first new sequence (SEQ ID NO: 1) totals 68 amino acids and is: Cys-Gln-Ser-Leu-Gln-Glu-Tyr-Leu-Ala-Glu-Gln-Asn-Gln-Arg-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Val-Asp-Leu-Ala-Agr-Val-Val-Ala-Pro-Phe-Met-Ser-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Arg-Pro-Arg-Ser-Gln-Pro-Gln-Pro-Lys-Ala-Asn-Glu-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH)
The second new sequence (SEQ ID NO: 2) totals 69 amino acids and is: Cys-Glu-Ser-Leu-Gln-Lys-His-Leu-Ala-Glu-Leu-Asn-His-Gln-Lys-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Leu-Asp-Met-Thr-Glu-Val-Val-Ala-Pro-Phe-Met-Ala-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Gly-Pro-Arg-Ser-Lys-Pro-Gln-Pro-Lys-Asp-Asn-Gly-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH)
The third new sequence (SEQ ID NO: 3) totals 67 amino acids and is: Cys-Gln-Ser-Leu-Gln-Lys-His-Leu-Ala-Ala-Met-Lys-Leu-Gln-Lys-Gln-Leu-Gln-Ser-Asn-Lys-Ile-Pro-Glu-Leu-Asp-Phe-Ser-Glu-Leu-Thr-Ser-Pro-Phe-Met-Ala-Asn-Val-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Lys-Pro-Lys-Gln-Lys-Ser-Lys-Ala-Thr-Glu-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH)
A prior art sequence (SEQ ID NO: 4) considered in comparison in Example 2 totals 60 amino acids and is: Cys-Gln-Ser-Leu-Gln-Glu-Tyr-Leu-Ala-Glu-Gln-Asn-Gln-Arg-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Val-Asp-Leu-Ala-Arg-Val-Val-Ala-Pro-Phe-Met-Ser-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Arg-Pro-Arg-Ser-Gln-Pro-Gln-Pro-Lys-Ala-Asn-Glu-Asp-Val-Cys (reading, first to last, from NH 2 to COOH)
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in graphic form the mean ratio comparing percentage of frozen-thawed rooster sperm bound to an egg-membrane substrate for peptide-treated v. control aliquots of the same seminal samples. All three peptides were incubated at 0, 20 and 80 ng peptide/million sperm prior to evaluation. Ration % bound calculated as: % bound with Peptide / % bound for Control; and
FIG. 2 shows in graphic form the mean percentage of fertilized eggs laid by hens inseminated four times at 4-day intervals with a limited number of frozen-thawed rooster sperm exposed to 0.2, 0.5, 1.0 or 2.0 μM SEQ ID NO: 4 (left); untreated control sperm (center); or 0.2, 0.5, 1.0 or 2.0 μM SEQ ID NO 1 (right). Each bar based on >425 eggs.
DETAILED DESCRIPTION OF THE INVENTION
In the course of advancing technology disclosed by Hammerstedt et al. (1997) we had reason to have chemically synthesized a novel sequence which: (1) departs from and adds to SEQ ID #12 of Hammerstedt et al. (1997); and (2) incorporates an amino acid sequence not found in the corresponding portion of the prosaposin molecule. This sequence is presented as SEQ ID NO: 1. The analogous new sequences in human and chicken prosaposin are presented as SEQ ID NO: 2 and SEQ ID NO: 3.
The first new sequence (SEQ ID NO: 1) totals 68 amino acids and is: Cys-Gln-Ser-Leu-Gln-Glu-Tyr-Leu-Ala-Glu-Gln-Asn-Gln-Arg-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Val-Asp-Leu-Ala-Agr-Val-Val-Ala-Pro-Phe-Met-Ser-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Arg-Pro-Arg-Ser-Gln-Pro-Gln-Pro-Lys-Ala-Asn-Glu-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH).
The second new sequence (SEQ ID NO: 2) totals 69 amino acids and is: Cys-Glu-Ser-Leu-Gln-Lys-His-Leu-Ala-Glu-Leu-Asn-His-Gln-Lys-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Leu-Asp-Met-Thr-Glu-Val-Val-Ala-Pro-Phe-Met-Ala-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Gly-Pro-Arg-Ser-Lys-Pro-Gln-Pro-Lys-Asp-Asn-Gly-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH)
The third new sequence (SEQ ID NO: 3) totals 67 amino acids and is: Cys-Gln-Ser-Leu-Gln-Lys-His-Leu-Ala-Ala-Met-Lys-Leu-Gln-Lys-Gln-Leu-Gln-Ser-Asn-Lys-Ile-Pro-Glu-Leu-Asp-Phe-Ser-Glu-Leu-Thr-Ser-Pro-Phe-Met-Ala-Asn-Val-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Lys-Pro-Lys-Gln-Lys-Ser-Lys-Ala-Thr-Glu-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His (reading, first to last, from NH 2 to COOH)
A prior art sequence (SEQ ID NO: 4) considered in comparison in Example 2 totals 60 amino acids and is: Cys-Gln-Ser-Leu-Gln-Glu-Tyr-Leu-Ala-Glu-Gln-Asn-Gln-Arg-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Val-Asp-Leu-Ala-Arg-Val-Val-Ala-Pro-Phe-Met-Ser-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Arg-Pro-Arg-Ser-Gln-Pro-Gln-Pro-Lys-Ala-Asn-Glu-Asp-Val-Cys (reading, first to last, from NH 2 to COOH).
SEQ ID NO: 1 was prepared in anticipation that the six histidine tail would facilitate binding to a Ni-column. Although we have not tested that feature of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3, we have evaluated bioactivity of SEQ ID NO: 1. We have found, as did Barbato et al. (1998) , that in vitro binding of sperm to an egg membrane substrate is diagnostic of fertilizing potential of sperm in that seminal sample. Hence, we compared the increase in binding of rooster sperm induced by brief exposure to selected concentrations of a prior art peptide of Hammerstedt el al. (1997), known to be bioactive in vitro, with similar concentrations of SEQ ID NO:- -- 1 and, unexpectedly, we found that the benefit from SEQ ID NO: 1 was substantially greater. There was a greater increase in percent sperm bound and a wider range in effective concentrations.
Subsequently, we conducted a fertility trial using frozen-thawed rooster sperm exposed to SEQ ID NO: 1 versus a prior art peptide. Again, to our surprise, we found that the peptide of SEQ ID NO: 1 had greater bioactivity than the prior art peptide, in terms of both increasing the percentage of eggs laid which were fertilized and in having a wider range of effective concentrations. Hence, it appears that with SEQ ID NO: 1 careful control of the molar concentration, or mass of peptide per billion sperm, is far less critical than with the peptide of the prior art. This should facilitate actual use in the field. Most importantly, the likely increase in number of young hatched (poultry) or born (mammals) would be greater.
Based on fertility trials with chickens, turkeys and cattle using a preferred peptide disclosed in the prior art, we obtained results similar to those of Hammerstedt et al. (1997), as we also have using the same sperm-binding assay with bull, horse, human, mouse and pig sperm. Hence, we anticipate that SEQ ID NO: 1 will be equally advantageous with these species as it is with chickens.
The peptide represented by SEQ ID NO: 1 differs from those of the prior art by extension of the COOH end. This extension consists of two possibly irrelevant amino acids plus six histidine amino acids. The corresponding eight amino acids in rat prosaposin are: Gln-Asp-Cys-Met-Lys-Leu-Val-Thr. The corresponding eight amino acids in human prosaposin are: Gln-Asp-Cys-Ile-Gln-Met-Val-Thr. The corresponding eight amino acids in chicken prosaposin are: Gln-Asp-Cys-Ile-Arg-Leu-Val-Thr. None of these sequences is similar to the addition used in SEQ ID NO: 1, namely: Val-Asn-His-His-His-His-His-His. Hence, knowledge of the prosaposin molecule would not logically have led to addition of these amino acids. However, we anticipate that insertion of two to six irrelevant amino acids between the cysteine and first histidine, rather than the Val-Asn of SEQ ID NO: 1, or incorporation of a repeat of seven or eight rather than six histidine amino acids would similarly improve over the prior art. Further, we speculate that addition of a repeat of six to eight histidine amino acids, with a spacer of two to six irrelevant amino acids, to the cysteine amino acid on the NH 2 terminus of prior art peptides, rather than to the COOH end, also might enhance bioactivity.
SEQ ID NO: 1 also differs from another prior art peptide of Hammerstedt et al. (1997) which, although substantially shorter than SEQ ID NO: 1, extended nine amino acids in the COOH direction beyond the terminal cystine. This prior art peptide had essentially no bioactivity (Hammerstedt et al., 1997). Hence, knowledge of the other sequences disclosed and tested by Hammerstedt et al. (1997) would not logically have led to addition of these amino acids.
Finally, the extension on the COOH end which distinguishes SEQ ID NO: 1 from the first above mentioned prior art peptide of Hammerstedt et al. (1997), namely Val-Asn-His-His-His-His-His-His,was made because the histidine-repeat sequence is known to facilitate binding to a Ni-column. However, the literature on use of Ni-columns or histidine-repeat sequencesdoes not include the concept that a sequence such as Val-Asn-His-His-His-His-His-His would increase the pro-fertility action of a parent peptide. There appears to be no prior art or basis for the observed effects.
EXAMPLE 1
We used the BioPore® Sperm-Binding Assay (Amann et al., 1999) to compare. percentage of sperm binding to an egg-membrane substrate (similar to Barbato et al., 1998) after brief in vitro exposure to three concentrations of a prior art peptide (Hammerstedt et al., 1997), representing each of two lots of peptide SEQ ID NO: 4 (after disulfide linking the cystine residues) or three concentrations of SEQ ID NO: 1 (after disulfide linking the cystine residues). Briefly, cryopreserved rooster semen (Gill et al., 1996) from broiler males (Barbato et al., 1998) was thawed, deglycerolated (Gill et al., 1996), and adjusted to provide a concentrated suspension of sperm in an appropriate salts buffer. We used one containing: 0.600 g sodium glutamate, 0.210 g potassium glutamate, 0.100 g glucose, 0.070 g sorbitol, 0.035 g magnesium sulfate, 0.210 g potassium acetate, 0.050 g potassium citrate, 0.700 g di-potassium phosphate, 0.160 g mono-potassium phosphate, 0.800 g di-sodium phosphate, 0.100 9 potassium hydroxide, 0.300 g N,N -bis[2-hydroxyethyl]-2-aminoethanesulfonic acid, 0.400 g N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid], and 0.400 g N-tris[hydroxymethyl]methyl-2-aminoethanesulfonic acid, dissolved in distilled water to make 100 ml (Tajima et al., 1989). Aliquots of this suspension were placed in tubes containing one of the three peptide sequences at 0, 20 or 80 ng per million sperm. After mixing and 10 minutes incubation at 37° C., the suspensions were further diluted and assayed using 2 million sperm/well in the microwell assay plates. Plates were incubated at 32° C. for 60 min, after which unbound sperm were decanted, the wells washed, and the DNA in sperm bound to the egg-membrane substrate in the microwell plates quantified (Barbato et al., 1998). Resultant data (FIG. 1) revealed that for the 2 preparations of SEQ ID NO: 4 maximum benefit was at 20 ng/million sperm; binding was 1.13 and 1.17× the value for the non-peptide control. With SEQ ID NO: 1, however, binding for suspensions exposed to either 20 or 80 ng/million sperm was greater, namely 1.20 and 1.22 the control value.
EXAMPLE 2
To compare fertility achieved after exposure of rooster sperm to SEQ ID NO: 4 and SEQ ID NO: 1, we used cryopreserved semen as in Example 1. To facilitate detection of benefit from peptides, we used a limited number of sperm for each artificial insemination. Pooled, deglycerolated semen (1 billion sperm/ml; at 0-4C.), in salts buffer as described in Example 1, was dispensed into tubes containing SEQ ID NO: 4 or SEQ ID NO: 1 to make nine suspensions: 0.0 (control), 0.2, 0.5, 1.0 or 2.0 μM and mixed. Artificial insemination of White Leghorn hens (40/group) was within 1 hour, and used 50 μl (50 million sperm). Eggs were collected daily, stored ≦7 d at 14C., incubated, and candled on day 7 (eggs with viable embryo were classed as fertile). Data resulting from four inseminations at 4-day intervals are shown (FIG. 2). It was concluded that both 0.2 and 0.5 μM SEQ ID NO: 4 improved fertility as did 0.2, 0.5, 1.0 and 2.0 μM SEQ ID NO: 1. Hence, SEQ ID NO: 4 was of benefit over a narrow ˜2.5-fold range (0.2 to 0.5 μM) where as SEQ ID NO: 1 was of benefit over a ≧10- fold range (0.2 to 2.0 μM). The increase in fertility (above the control value) with the best concentration of SEQ ID NO: 1 (15.4 units at 2.0 μM) was 2.0× that with SEQ ID NO: 4 (7.8 units at 0.5 μM). Clearly, brief in vitro exposure of sperm to SEQ ID NO: 1 rather than SEQ ID NO: 4 before artificial insemination gave a greater increase in percentage of fertilized eggs over a greater range in concentration.
Literature Cited
Amann R P and Hammerstedt R H (1993), "In vitro evaluation of sperm quality: an opinion," J Andrology 14:397-406.
Amann R P, Hammerstedt R H and Shabanowitz R B (1999), "Exposure of human, bull or boar sperm to a synthetic peptide increases binding to an egg-membrane substrate" J Androloqy 20:34-41.
Azuma N, Seo H-C, Lie .o slashed., F Y Q, Gould R M, Hiraiwa M, Burt D W, Patton I R, Morrices D R, O'Brien J S and Kishimoto Y (1998), "Cloning, expression and map assignment of chicken prosaposin," Biochem J 330:321-327.
Barbato G F, Cramer P G and Hammerstedt R H (1998), "A practical in vitro sperm-egg binding assay that detects subfertile males," Biol Reprod 58:686-699.
Collard M W, Sylvester S R, Tsuruta J K and Griswold M D (1988), "Biosynthesis and molecular cloning of sulfated glycoprotein-1 secreted by rat Sertoli cells: sequence similarity with the 70-kilodalton precursor to sulfatide/GM 1 activator," Biochemistry 27:4557-4564.
Hammerstedt R H (1996), "Evaluation of sperm quality: Identification of the subfertile male and courses of action," Anim Reprod Sci 42:77-87.
Hammerstedt R H, Cramer P G and Barbato G F (1997), "A method and use of polypeptide in sperm-egg binding to enhance or decrease fertility," International Patent Publication Number WO/97/25620. 41 pp.
Hermo L, Morales C and Oko R (1992), "Immunocytochemical localization of sulfated glycoprotein-1 (SGP-1) and identification of its transcripts in epithelial cells of the extratesticular duct system of the rat," Anat Rec 232:401-422.
Hiraiwa M, O'Brien J S, Kishimoto Y, Galdzicka M, Fluharty A L, Ginns E I and Martin D M (1993), Arch Biochem Biophys 302:110-116.
Igdoura S A and Morales C R (1995), "Role of sulfated glycoprotein-1 (SGP-1) in the disposal of residual bodies by Sertoli cells of the rat," Mol Reprod Dev 40:91-102.
Igdoura S A, Hermo L, Rosenthal A and Morales C R (1993), "Nonciliated cells of the rat efferent ducts endocytose testicular sulfated glycoprotein-1 (SGP-1) and synthesize SGP-1 derived saposins," Anat Rec 235:411-424.
Kishimoto Y, Hiraiwa M and O'Brien J S (1992), "Saposins: structure, function, distribution, and molecular genetics," J Lipid Res 33;1255-1267.
Munford R S, Sheppard P O and O'Hara P J (1995), "Saposin-like proteins (SAPLP) carry out diverse functions on a common backbone structure," J Lipid Res 36;1653-1663.
O'Brien J S and Kishimoto Y (1991), "Saposin proteins: structure, function, and role in human lysosomal storage disorders," FASEB J 5:301-308.
Rosenthal A L, Igdoura S A, Morales C R and Hermo L (1915), "Hormonal regulation of sulfated glycoprotein-1 synthesis by nonciliated cells of the efferent ducts of adult rats," Mol Reprod Dev 40:69-83.
Sylvester S R, Skinner M K and Griswold M D (1984), "A sulfated glycoprotein synthized by Sertoli cells and by epididymal cells is a component of the sperm membrane," Biol Reprod 31:1087-1101.
Sylvester S R, Morales C, Oko R and Griswold M D (1989) , "Sulfated glycoprotein-1 (saposin precursor) in the reproductive tract of the male rat," Biol Reprod 41:941-948.
Gill S P S, Buss E G and Mallis R J (1996), "Cryopreservation of rooster semen in thirteen and sixteen percent glycerol," Poultry Sci 75:254-256.
Tajima A, Graham E F and Hawkins D M (1989), "Estimation of the relative freezing ability of frozen chicken spermatozoa using heterospermic competition method," J Reprod Fertil 85:1-5.
__________________________________________________________________________# SEQUENCE LISTING - - - - <160> NUMBER OF SEQ ID NOS: 4 - - <210> SEQ ID NO 1 <211> LENGTH: 68 <212> TYPE: PRT <213> ORGANISM: Unknown <220> FEATURE: <223> OTHER INFORMATION: varient of avian prosapos - #in - - <400> SEQUENCE: 1 - - Cys Gln Ser Leu Gln Glu Tyr Leu Ala Glu Gl - #n Asn Gln Arg Gln Leu 1 5 - # 10 - # 15 - - Glu Ser Asn Lys Ile Pro Glu Val Asp Leu Al - #a Ala Val Val Ala Pro 20 - # 25 - # 30 - - Phe Met Ser Asn Ile Pro Leu Leu Leu Tyr Pr - #o Gln Asp Arg Pro Arg 35 - # 40 - # 45 - - Ser Gln Pro Gln Pro Lys Ala Asn Glu Asp Va - #l Cys Val Asn His His50 - # 55 - # 60 - - His His His His 65 - - - - <210> SEQ ID NO 2 <211> LENGTH: 69 <212> TYPE: PRT <213> ORGANISM: Homo sapiens - - <400> SEQUENCE: 2 - - Cys Glu Ser Leu Gln Lys His Leu Ala Glu Le - #u Asn His Gln Lys Gln 1 5 - # 10 - # 15 - - Leu Glu Ser Asn Lys Ile Pro Glu Leu Asp Me - #t Thr Glu Val Val Ala 20 - # 25 - # 30 - - Pro Phe Met Ala Asn Ile Pro Leu Leu Leu Ty - #r Pro Gln Asp Gly Pro 35 - # 40 - # 45 - - Arg Ser Lys Pro Gln Pro Lys Asp Asn Gly As - #p Val Cys Val Asn His50 - # 55 - # 60 - - His His His His His 65 - - - - <210> SEQ ID NO 3 <211> LENGTH: 67 <212> TYPE: PRT <213> ORGANISM: Avian - - <400> SEQUENCE: 3 - - Cys Gln Ser Leu Gln Lys His Leu Ala Ala Me - #t Lys Leu Gln Lys Gln 1 5 - # 10 - # 15 - - Leu Gln Ser Asn Lys Ile Pro Glu Leu Asp Ph - #e Ser Glu Leu Thr Ser 20 - # 25 - # 30 - - Pro Phe Met Ala Asn Val Pro Leu Leu Leu Ty - #r Pro Gln Asp Lys Pro 35 - # 40 - # 45 - - Lys Gln Lys Ser Lys Ala Thr Glu Asp Val Cy - #s Val Asn His His His50 - # 55 - # 60 - - His His His 65 - - - - <210> SEQ ID NO 4 <211> LENGTH: 60 <212> TYPE: PRT <213> ORGANISM: Avian - - <400> SEQUENCE: 4 - - Cys Gln Ser Leu Gln Glu Tyr Leu Ala Glu Gl - #n Asn Gln Arg Gln Leu 1 5 - # 10 - # 15 - - Glu Ser Asn Lys Ile Pro Glu Val Asp Leu Al - #a Arg Val Val Ala Pro 20 - # 25 - # 30 - - Phe Met Ser Asn Ile Pro Leu Leu Leu Tyr Pr - #o Gln Asp Arg Pro Arg 35 - # 40 - # 45 - - Ser Gln Pro Gln Pro Lys Ala Asn Glu Asp Va - #l Cys50 - # 55 - # 60__________________________________________________________________________
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A synthetic peptide with enhanced pro-fertility action was produced by inclusion of additional amino acids at the carboxyl end of a previously disclosed synthetic peptide. Improvement in bioactivity over the previously disclosed peptide was demonstrated. A direct comparison of an earlier known synthetic peptide and an extended peptide involved brief exposure of sperm in vitro to one or the other peptide at several concentrations. When sperm then were evaluated in vitro using an egg-membrane substrate, an increased percentage of sperm bound for cells exposed to the new extended peptide. Similarly, when fertility of sperm after artificial insemination was the criterion, a greater percentage of eggs was fertilized by sperm exposed to the new extended peptide. In one preferred embodiment, this enhanced pro-fertility action was achieved with a peptide having a 68 amino acid sequence (SEQ ID NO 1:): Cys-Gln-Ser-Leu-Gln-Glu-Tyr-Leu-Ala-Glu-Gln-Asn-Gln-Arg-Gln-Leu-Glu-Ser-Asn-Lys-Ile-Pro-Glu-Val-Asp-Leu-Ala-Agr-Val-Val-Ala-Pro-Phe-Met-Ser-Asn-Ile-Pro-Leu-Leu-Leu-Tyr-Pro-Gln-Asp-Arg-Pro-Arg-Ser-Gln-Pro-Gln-Pro-Lys-Ala-Asn-Glu-Asp-Val-Cys-Val-Asn-His-His-His-His-His-His.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention broadly relates to braces used in orthodontic treatment. More particularly, this invention relates to orthodontic braces that have a reduced profile.
[0003] 2. Description of the Related Art
[0004] Orthodontic therapy is a specialized type of treatment within the field of dentistry, and involves movement of malpositioned teeth to improved locations along the dental arches. Orthodontic treatment often enhances the patient's facial appearance, especially in regions near the front of the oral cavity. Orthodontic treatment can also improve the patient's occlusion so that the teeth function better with each other during mastication.
[0005] Many types of orthodontic treatment programs involve the use of a set of appliances and archwires that are commonly known collectively as “braces”. During such treatment programs, tiny slotted appliances known as brackets are fixed to the patient's anterior, cuspid and bicuspid teeth. The slots of these brackets receive an archwire, allowing the archwire to guide the teeth into orthodontically correct locations during the course of treatment. End sections of the archwires are often captured in tiny appliances known as molar tubes that are fixed to the patient's molar teeth.
[0006] Orthodontic brackets often have small wings known as “tiewings” that are connected to a body of the bracket. Once the bracket has been attached to a tooth and an archwire has been received into the archwire slot of the bracket, a ligature is coupled to the bracket in order to retain the archwire in the archwire slot. One common type of commercially available orthodontic ligature is a small, elastomeric O-ring that is installed by stretching the O-ring along a path behind the tiewings and over the facial side of the archwire. Another option is to use stainless steel ligature wire, which can similarly be looped along a path behind the tiewings and over the facial side of the archwire and tightly secured by twisting together the ends.
[0007] Certain types of orthodontic brackets known as self-ligating brackets are provided with a latch that allows an archwire to be coupled to the brackets without using ligatures or ligature wire. This latch may comprise a movable clip, spring member, cover, shutter, bail or other structure that is connected to the bracket body for retaining the archwire in the archwire slot. Self-ligating brackets can allow free and easy sliding of the archwire through the archwire slot, and this in turn can facilitate movement of teeth in early stages of treatment. While not required, tiewings are still used on many self-ligating brackets since they offer the practitioner increased flexibility in achieving specific treatment objectives. For example, a practitioner may elect to use ligatures for cases in which increased friction (i.e. resistance to sliding) is desirable. This in turn can help retain the teeth in their proper orthodontic positions when using a full sized archwire in the finishing stages of treatment.
[0008] Self-ligating or otherwise, it is common for brackets with tiewings to have one or more tiewings residing on both the gingival and occlusal sides of the bracket. Such a design offers convenient paths for the ligature to cross over the facial side of the archwire. Brackets with four tiewings are especially common, and allow the ligature to secure the archwire in various configurations, including standard, double-over tie, figure- 8 , and corner-to-corner, each of which can be used advantageously by one skilled in the art.
[0009] On occasion, a bracket on one arch (typically the lower arch) interferes with teeth on the opposite arch. In response, a practitioner may delay bonding of an appliance until the obstructive teeth have been safely moved out of the way. While this is one solution, this delay extends treatment time. Alternatively, orthodontic practitioners may elect to remove a portion or all of the tie wings from the problematic bracket, by grinding or some other means, to eliminate interferences. Using smaller sized appliances may help alleviate occlusal interferences. However, it can be challenging to reduce the size of an appliance without compromising its functionality.
[0010] There is a present need in the art for an orthodontic brace that includes appliances that are smaller in size, especially a brace which can alleviate difficulties with occlusal interferences.
SUMMARY OF THE INVENTION
[0011] This invention provides a brace for a dental arch that alleviates problems with occlusal interference and enhances patient comfort, hygiene, and bracket aesthetics. This brace comprises a set of orthodontic brackets and includes: at least one central incisor bracket, at least one lateral incisor bracket, and at least one cuspid bracket, wherein each bracket of the set includes a base, a body extending outwardly from the base, and an archwire slot extending across the body, wherein each bracket of the set includes at least one gingival tiewing and lacks any occlusal tiewing.
[0012] Another aspect of the invention is directed towards a brace that comprises a set of orthodontic brackets that includes at least one central incisor bracket, at least one lateral incisor bracket, and at least one cuspid bracket, wherein each bracket of the set includes a base, a body extending outwardly from the base, an archwire slot extending across the body and a single gingival tiewing, while lacking occlusal tiewings.
[0013] Yet another aspect of the invention is directed towards a brace that comprises a set of orthodontic brackets that includes at least one central incisor bracket, at least one lateral incisor bracket, and at least one cuspid bracket, wherein each bracket of the set includes a base, a body extending outwardly from the base, an archwire slot extending across the body, at least one gingival tiewing, and a latch for releasably retaining an archwire in the archwire slot of the bracket, while lacking occlusal tiewings.
[0014] Still other aspects of the invention are directed towards extending the set of orthodontic brackets to include 1 st bicuspid and 2 nd bicuspid brackets. Yet still other aspects of the invention are directed towards extending the set of orthodontic brackets to include a bracket with a latch comprising a single centrally located clip, or with a latch comprising clips that also function as tiewings.
[0015] In the aforementioned aspects of the invention, latches and/or gingival tiewings enable an archwire to be coupled to the brackets. Moreover, the absence of occlusal tiewings allows interferences between the bracket and teeth positioned on the opposite dental arch to be minimized or eliminated. This is especially useful in a “deep bite” situation in which the upper incisors descend over the lower anterior teeth in occlusion. With fewer bracket/tooth interferences, the likelihood of premature, spontaneous debonding of the interfering bracket and/or enamel damage are likewise reduced.
[0016] The absence of occlusal tiewings also reduces potential irritation, swelling, and overall patient discomfort caused by brackets rubbing against the cheeks and lips of a patient throughout treatment. Hygiene is improved as well because less food and plaque is trapped beneath the tiewings during treatment. Improved patient hygiene in turn promotes improved gum health and reduced incidence of dental caries and/or decalcification. Lastly, this brace offers improved aesthetic appeal, since there are no occlusal tiewings protruding from the bracket body. The inventive orthodontic brace uses brackets that are visibly smaller.
[0017] Aspects of the present invention are set out in the detailed description that follows and are illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a front elevational view showing the lower teeth of an exemplary patient undergoing orthodontic treatment, wherein orthodontic appliances are fixed to the teeth and an archwire connected to the appliances by means of latches on said appliances.
[0019] FIG. 2 is a front view of an individual bracket shown in FIG. 1 , looking at the bracket towards its facial side.
[0020] FIG. 3 is a side view of an individual bracket shown in FIGS. 1 and 2 , looking at the bracket towards its mesial side.
[0021] FIG. 4 is a perspective view of an individual bracket shown in FIGS. 1-3 , looking at the bracket towards its mesial, facial, and occlusal sides.
[0022] FIG. 5 is a side view of an assembly depicting the bracket shown in FIGS. 1-3 coupled to an archwire by using an elastic ligature, looking at the assembly towards its mesial side.
[0023] FIG. 6 is a perspective view of an assembly depicting the bracket shown in FIGS. 1-3 coupled to an archwire by using an elastic ligature, looking at the assembly towards its mesial, facial, and occlusal sides.
[0024] FIG. 7 is a front view of an orthodontic bracket according to another embodiment of the invention, looking at the bracket towards its facial side.
[0025] FIG. 8 is a side view of the bracket shown in FIG. 5 , looking at the bracket towards its mesial side.
[0026] FIG. 9 is a perspective view of the bracket shown in FIGS. 5 and 6 , looking at the bracket towards its mesial, facial, and occlusal sides.
[0027] FIG. 10 is a perspective view of an orthodontic bracket according to another embodiment of the invention, looking at the bracket towards its mesial, facial, and occlusal sides.
[0028] FIG. 11 is a front view of an orthodontic bracket according to another embodiment of the invention, looking at the bracket towards its facial side.
[0029] FIG. 12 is a side view of the bracket shown in FIG. 9 , looking at the bracket towards its distal side.
[0030] FIG. 13 is a perspective view of the bracket shown in FIGS. 9 and 10 , looking at the bracket towards its mesial, facial, and gingival sides.
[0031] FIG. 14 is a perspective view of an orthodontic bracket according to another embodiment of the invention, looking at the bracket towards its distal, facial, and occlusal sides.
DEFINITIONS
[0032] “Mesial” means in a direction toward the center of a patient's curved dental arch.
[0033] “Distal” means in a direction away from the center of a patient's curved dental arch.
[0034] “Occlusal” means in a direction toward the outer tips of a patient's teeth.
[0035] “Gingival” means in a direction toward the patient's gum or gingiva.
[0036] “Facial” means in a direction toward the patient's lips.
[0037] “Lingual” means in a direction toward the patient's tongue.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIG. 1 shows an example of a lower dental arch broadly designated by the numeral 2 of an orthodontic patient that is undergoing orthodontic treatment. An orthodontic brace 4 is connected to the teeth of the lower dental arch 2 . The brace 4 includes a set of appliances as well as an archwire that receives the appliances, as will be described in greater detail below.
[0039] In this example, each tooth in the lower dental arch 2 is coupled to an orthodontic appliance. Specifically, lower central teeth 6 and lower lateral teeth 8 are coupled to lower anterior brackets 10 , cuspid teeth 12 are coupled to cuspid brackets 14 , 1 st bicuspid teeth 16 are coupled to 1 st bicuspid brackets 18 , 2 nd bicuspid teeth 20 are coupled to 2 nd bicuspid brackets 22 , first molars 24 are coupled to molar tube 26 , and second molars 28 are coupled to second molar tubes 30 . Appliances 10 , 14 , 18 , and 22 are of a type known as “self-ligating” brackets. Features associated with these brackets shall be described in detail in subsequent illustrations. For exemplary purposes, illustrated brackets 10 , 14 , 18 , and 22 and molar tubes 26 and 30 are metal appliances directly bonded to the patient's tooth enamel, although other appliances and/or methods of coupling could be used. An archwire 32 is received in the slots of brackets 10 , 14 , 18 , and 22 , and molar tubes 26 and 30 .
[0040] The exemplary cuspid bracket 14 used in orthodontic brace 4 is shown from three different perspectives in FIGS. 2-4 . The bracket 14 includes a base 42 and a body 44 that extends outwardly from base 42 . The body 44 includes a mesial side 46 a along with a distal side 46 b . Body 44 also includes a pair of gingival posts 45 and a pair of occlusal posts 47 . An elongated archwire slot 38 extends in a generally mesial-distal direction across the body 44 from the mesial side 46 a to the distal side 46 b and between gingival posts 45 and occlusal posts 47 . Archwire slot 38 has an overall rectangular shape in transverse cross-sectional view.
[0041] As previously mentioned, bracket 14 is of a type known as a “self-ligating” bracket. To this end, the bracket 14 has a latch that comprises a mesial spring clip 36 a and a distal spring clip 36 b . Mesial spring clip 36 a and distal spring clip 36 b each includes a first section 37 and a second section 39 spaced from first section 37 . Between first section 37 and second section 39 resides archwire-receiving region 41 , which is aligned with archwire slot 38 . When an orthodontic archwire (not shown in FIGS. 2-4 ) is urged in a direction toward the bottom of the archwire slot 38 , the clips 36 a and 36 b deflect and spread open to enable the archwire to be moved fully into archwire receiving region 41 , and hence also, archwire slot 38 . Once the archwire is seated into archwire slot 38 , the inherent resiliency of the clips 36 a and 36 b causes first section 37 and second section 39 to shift to their relaxed, closed position as depicted in FIGS. 2-4 for retaining the archwire in archwire slot 38 .
[0042] Preferably, the sides of the clips 36 a and 36 b deflect outwardly to a slot-open orientation and release the archwire from the archwire slot 38 whenever the force exerted by the archwire on the bracket 14 exceeds a certain minimum value. The minimum value is sufficiently high to prevent the archwire from unintentionally releasing from the archwire slot 38 during the normal course of orthodontic treatment. As such, the archwire can exert forces on the bracket 14 sufficient to carry out the intended treatment program and move the associated tooth as desired. Preferably, the clips 36 a and 36 b release the archwire from archwire receiving region 41 , and hence archwire slot 38 , in a direction perpendicular and away from the lingual side of the archwire slot 38 whenever the archwire exerts a force in the same direction on the bracket 14 that is in the range of about 0.2 lb (0.1 kg) to about 11 lbs (5 kg), more preferably in the range of about 0.4 lb (0.2 kg) to about 5.5 lbs (2.5 kg), and most preferably in the range of about 0.4 lb (0.2 kg) to about 2.7 lbs (1.25 kg).
[0043] Preferably, the minimum value for self-release (i.e., self-opening) of the clips 36 a and 36 b is together substantially less than the force required in the same direction to debond the bracket 14 from the associated tooth in instances where the bracket 14 is directly bonded to the tooth surface. The minimum value for self-release of the clips 36 a and 36 b is preferably less than about one-half of the force required in the same direction to debond the bracket 14 from the associated tooth. For example, if the expected bond strength of the adhesive bond between the bracket 14 and the associated tooth is 16 lbs (7.3 kg) in the facial direction, the clips 36 a and 36 b are constructed to self-release the archwire whenever the archwire exerts a force in the same facial direction on the appliance 36 a and 36 b that is somewhat greater than about 8 lbs (3.6 kg).
[0044] Each of clips 36 a and 36 b is preferably made from a flat annealed superelastic material having a pickled surface. Preferably, the superelastic material is nitinol having a nickel content of 55.97% by weight and an A f of 10°±5° C. The nitinol is cold worked to 37.5% and has a thickness in the range of about 0.012 in. (0.3 mm) to about 0.016 in. (0.4 mm). The clips 36 a and 36 b are first cut in a rough cutting laser process, and then optionally cut along their edges for an additional one or more times using an laser cutting process in order to smooth the edges.
[0045] Other details and features of the latch and the clips 36 a and 36 b are set out in applicants' issued patents entitled, “ORTHODONTIC APPLIANCE WITH SELF-RELEASING LATCH”—U.S. Pat. Nos. 6,302,688 and 6,582,226, and “ORTHODONTIC APPLIANCE WITH FATIGUE-RESISTANT ARCHWIRE RETAINING LATCH”—U.S. Pat. No. 7,014,460, which are expressly incorporated by reference herein.
[0046] The clips 36 a and 36 b are each held in place by mesial cap 40 a and distal cap 40 b , respectively. In this embodiment, the caps 40 a and 40 b are considered as part of the body 44 and attached to the mesial side 46 a and the distal side 46 b , respectively, as mentioned above. The caps 40 a and 40 b are fixed to protrusions that extend in a mesial-distal direction from the central section of the body 44 , and the protrusions are arranged to retain the clips 36 a and 36 b in place. For example, protrusions may be provided along the sides of the archwire slot 38 as well as along a portion or all of the lingual side of the clips 36 a and 36 b . The protrusions may be integral with either the central section or the caps 40 a and 40 b and then fixed to the other of the central section or the caps 40 a and 40 b by a welding or brazing operation. Protrusions and caps can be integral with the bracket body using the metal injection molding process to fabricate the bracket. Bracket 14 also includes a pair of tiewings 48 that protrude from the gingival posts 45 of the body 44 . Tiewings 48 are parallel to each other and initially extend in the gingival direction from gingival posts 45 then bend in a gradual curve towards the lingual direction towards base 42 .
[0047] FIGS. 5 and 6 demonstrate, in side view and perspective view, how tiewings 48 (designated here as 48 a and 48 b ) can be advantageously used to provide an alternate route for coupling archwire 32 to bracket 14 in orthodontic brace 4 .
[0048] Here, assembly 50 includes the bracket 14 and archwire 32 that is received in archwire slot 38 . Assembly 50 furthermore includes elastic ligature 52 , which travels along a continuous path over the facial, occlusal, and lingual sides of archwire 32 on the distal side 46 b of bracket 14 , beneath distal tiewing 48 b , beneath mesial tiewing 48 a , over the lingual, occlusal, and facial sides of archwire 32 on the mesial side 46 a , beneath mesial tiewing 48 a , then finally beneath distal tiewing 48 b . To arrive at this configuration, elastic ligature 52 is first looped around mesial and distal tiewings 48 a and 48 b and gingival posts 45 . Archwire 32 is then received into archwire slot 38 . Then the portion of elastic ligature 52 located occlusal to archwire 32 is stretched up and over the labial side of archwire 32 and finally secured beneath mesial and distal tiewings 48 a and 48 b , respectively.
[0049] In such fashion, archwire 32 is securely retained in archwire slot 38 , demonstrating a secondary means for a practitioner to couple archwire 32 to bracket 14 . The configuration shown in assembly 50 for coupling archwire 32 to bracket 14 is easily extended to other types of ligatures such as stainless steel ligature ties. It is likewise straightforward to extend the configuration shown in assembly 50 to couple archwire 32 to other member brackets 10 , 18 , and 22 of orthodontic brace 4 on dental arch 2 . Using bracket 14 , a practitioner has the option of coupling archwire 32 to bracket 14 using clips 36 a and 36 b alone, or in combination with an elastic ligature 52 (or similar ligature tie) looped around tiewings 48 a and 48 b as described above.
[0050] Note here that bracket 14 lacks occlusal tiewings. The phrase “lacks occlusal tiewings” as used herein denotes that there is no recess, notch, protrusion or otherwise retaining feature present on the bracket that can be used to support a ligature on the occlusal side of the archwire slot during the course of orthodontic treatment. Preferably, the bracket 14 has no structure that has all of the following characteristics: (a) it is located in a facial direction relative to the base, (b) it is located in an occlusal direction relative to an occlusal reference plane passing through the center of the archwire slot, (c) it extends in an occlusal direction or in a generally occlusal direction, and (d) it is sufficiently large to support a ligature during the course of orthodontic treatment.
[0051] In another embodiment, exemplary bracket 54 is used in place of bracket 14 in orthodontic brace 4 . Bracket 54 is shown in FIGS. 7-9 in front view, side view, and perspective view, respectively. Bracket 54 includes a base 42 a and a body 44 a that extends outwardly from base 42 a . The body 44 a includes a distal side 46 c along with a mesial side 46 d . Body 44 a also includes two gingival posts 45 a and two occlusal posts 47 a . An elongated archwire slot 38 a extends in a generally distal-mesial direction across the body 44 from the distal side 46 c to the mesial side 46 d and between gingival posts 45 a and occlusal posts 47 a . Bracket 54 also includes a pair of tiewings 49 that are parallel and protrude from gingival posts 45 a of body 44 a initially in the gingival direction, then gradually curve towards the lingual direction. In this embodiment, an archwire (not shown) can be coupled to bracket 54 using an elastic ligature or stainless steel ligature tie as shown previously using the configuration depicted in FIGS. 5 and 6 .
[0052] In still another embodiment, exemplary bracket 56 is used in place of bracket 14 in orthodontic brace 4 . Bracket 56 is shown in FIG. 10 in perspective view and is essentially identical to bracket 54 depicted in FIGS. 7-9 except bracket 56 includes a single occlusal post 62 , single gingival post 65 , and single tiewing 68 that protrudes from gingival post 65 . Gingival tiewing 68 protrudes in a perpendicular fashion from gingival post 65 in the gingival direction and then curves in a gradual arc towards the lingual direction. An archwire (not shown) can be coupled to bracket 56 using an elastic ligature or stainless steel ligature tie using a configuration similar to that shown in FIGS. 5 and 6 as described previously.
[0053] Yet another embodiment uses exemplary bracket 69 , illustrated by FIGS. 11-13 in front view, side view, and perspective view, respectively. Bracket 69 can be used in place of bracket 14 in orthodontic brace 4 , and is nearly identical to bracket 14 except tie wings 84 and 86 protrude not from the gingival posts but rather from clips 80 and 82 , respectively. Tiewings 84 and 86 are parallel and initially protrude from clips 80 and 82 in the gingival direction and then bend in a gradual curve towards the lingual direction. Bracket 69 has the ability to retain an archwire using clips 80 and 82 alone, or in combination with using an elastic ligature or stainless steel ligature tie (not pictured) guided around tiewings 84 and 86 , in a manner shown in FIGS. 5 and 6 previously.
[0054] An assembly 92 according to yet another embodiment of the invention is illustrated in FIG. 14 in perspective view. Assembly 92 includes exemplary bracket 94 coupled to archwire 32 . In this embodiment, bracket 94 is used in place of bracket 14 of orthodontic brace 4 . Bracket 94 is essentially identical to bracket 14 except the latch includes only one centrally located spring clip 110 . Bracket 94 has the ability to retain an archwire using clip 110 alone or in combination with using an elastic ligature or stainless steel ligature tie (not shown) in a manner shown in FIGS. 5 and 6 previously.
[0055] While the embodiments described above were exemplified on a lower dental arch, it is straightforward to adapt these embodiments for use on an upper dental arch. It should also be understood that the brackets included in any of the above embodiments can be formed from a variety of materials, including metals, ceramics, polymers, or any combination therefrom. Examples of such materials include, but are not limited to, stainless steel, polycrystalline alumina, and fiber-reinforced polycarbonate.
[0056] The examples described above are intended to exemplify the various aspects and benefits of the invention. However, those skilled in the art may recognize that a number of variations and additions to the appliances described above may be made without departing from the spirit of the invention. Accordingly, the invention should not be deemed limited to the specific embodiments set out above in detail, but instead only by a fair scope of the claims that follow, along with their equivalents.
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An orthodontic brace includes a set of orthodontic brackets for a dental arch that comprises at least one central incisor bracket, one lateral incisor bracket, and one cuspid bracket. Each bracket of the set lacks occlusal tiewings. Without occlusal tiewings, interferences with opposing teeth are substantially reduced and patient comfort, hygiene, and bracket aesthetics are enhanced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
U.S. patent application Ser. No. 064,633, "Stabilizing Bath For Use in Photographic Processing", P. A. Schwartz, filed June 22, 1987, now U.S. Pat. No. 4,786,583 issued Nov. 22, 1988, describes photographic stabilizing baths comprising a dye stabilizing agent and an alkanolamine.
U.S. patent application Ser. No. 202,729 "Photographic Stabilizing Bath Containing Hydrolyzed Polymaleic Anhydride", P. A. Schwartz, filed June 3, 1988, describes photographic stabilizing baths comprising a dye stabilizing agent, an alkanolamine and a hydrolyzed polymaleic anhydride or water-soluble salt thereof.
FIELD OF THE INVENTION
This invention relates in general to color photography and in particular to methods and compositions for use in the processing of color photographic elements. More specifically, this invention relates to a novel stabilizing bath which is useful in photographic color processing to provide reduced stain and enhanced dye stability.
BACKGROUND OF THE INVENTION
Multicolor, multilayer photographic elements are well known in the art of color photography. Usually, these photographic elements have three different selectively sensitized silver halide emulsion layers coated on one side of a single support. The vehicle used for these emulsion layers is normally a hydrophilic colloid, such as gelatin. One emulsion layer is blue-sensitive, another green-sensitive and another red-sensitive. Although these layers can be arranged on a support in any order, they are most commonly arranged with the support coated in succession with the red-sensitive layer, the green-sensitive layer and the blue-sensitive layer (advantageously with a bleachable blue-light-absorbing filter layer between the blue-sensitive layer and the green-sensitive layer) or with the opposite arrangement and no filter layer. Colored photographic images are formed from latent images in the silver halide emulsion layers during color development by the coupling of oxidized aromatic primary amine color developing agent with couplers present either in the color developer solution or incorporated in the appropriate light-sensitive layers. Color photographic elements containing dye images usually utilize a phenolic or naphtholic coupler that forms a cyan dye in the red-sensitive emulsion layer, a pyrazolone or cyanoacetyl derivative coupler that forms a magenta dye in the green-sensitive emulsion layer and an acetylamide coupler that forms a yellow dye in the blue-sensitive emulsion layer. Diffusible couplers are used in color developer solutions. Non-diffusing couplers are incorporated in photographic emulsion layers. When the dye image formed is to be used in situ, couplers are selected which form non-diffusing dyes. For image transfer color processes, couplers are used which will produce diffusible dyes capable of being mordanted or fixed in the receiving sheet.
It is well known in the photographic art to utilize a stabilizing bath as the final step in the processing of both color films and color papers. Such baths can serve to reduce stain and/or enhance dye stability. A wide variety of different stabilizing compositions have been proposed for such use. Thus, the known stabilizing baths include those containing addition products of formaldehyde and a diazine or triazine as described in Mackey et al, U.S. Pat. No. 2,487,569 issued Nov. 8, 1949; aliphatic aldehydes as described in Harsh et al., U.S. Pat. No. 2,518,686 issued Aug. 15, 1950; addition products of formaldehyde and a urea, as described in Mackey, U.S. Pat. No. 2,579,435 issued Dec. 18, 1951; tetramethylol cyclic alcohols or ketones as described in Clarke et al., U.S. Pat. No. 2,983,607 issued May 9, 1961; glucoheptonates as described in Bard, U.S. Pat. No. 3,157,504 issued Nov. 17, 1964; amino acids as described in Jeffreys, U.S. Pat. No. 3,291,606 issued Dec. 13, 1966; mixtures of an aldehyde and an alkoxy-substituted polyoxyethylene compound as described in Seemann et al., U.S. Pat. No. 3,369,896 issued Feb. 20, 1968; compounds comprising a tri(hydroxymethyl)methyl group as described in Jeffreys et al., U.S. Pat. No. 3,473,929 issued Oct. 21, 1969; and addition complexes of an alkali metal bisulfate and an aldehyde as described in Mowrey, U.S. Pat. No. 3,676,136 issued July 11, 1972.
The formation of yellow stain in photographic color elements is believed to be related to the presence of unreacted coupler in emulsion layers and to be influenced by a number of factors such as heat, humidity, conditions to which the photographic element was subject in development, e.g., development time, temperature and replenishment rate, the contamination of developing composition, such as contamination by bleaching agents, and so forth. Dye stability is believed to also be affected by the presence of unreacted coupler in emulsion layers (since coupler and dye can react slowly with one another to degrade a color image) and to be influenced by such factors as temperature, humidity, ambient oxygen, and the spectral distribution and intensity of the light to which the dye image is subjected. Magenta dye stability is a particular problem, as the magenta dye image tends to fade much more rapidly than either the cyan dye image or the yellow dye image. Thus, the problems of stain formation and dye stability are interrelated and highly complex, and the stabilizing compositions known heretofore have typically been deficient in one or more respects as regards the overcoming of these problems.
Processes which are intended for rapid access processing of photographic color elements pose a particular difficulty with respect to the provision of an effective stabilizing bath. In order to shorten the total processing time, such processes typically do not have a wash step following the fixing or bleach-fixing step, and in consequence, the element passes directly from the fixing or bleaching-fixing bath into the stabilizing bath. This results in carryover of the fixing agent, which is usually a thiosulfate, into the stabilizing bath. The result of such carryover is decomposition of the thiosulfate and precipitation of elemental sulfur in the stabilizing bath with resultant fouling of both the processing apparatus and the photographic element. This problem is commonly referred to as "sulfurization" of the stabilizing bath.
A novel stabilizing bath that is highly effective in reducing yellow stain formation and increasing dye stability, and which eliminates or greatly reduces the tendency for sulfurization to occur, is described in the aforesaid U.S. patent application Ser. No. 064,633, filed June 22, 1987. This stabilizing bath is comprised of a dye stabilizing agent and a sufficient amount of an alkanolamine to effectively retard sulfurization. One problem in the use of such a bath however, is the tendency for the formation of precipitates to occur. These precipitates are typically a result of the presence of calcium ions. The source of the calcium can be the photographic emulsion layers of the photographic element undergoing processing or the use of hard water in the formation or replenishment of the processing solutions. Such formation of precipitates is highly undesirable, as it can lead to the formation of sludge in the processing solutions, scum on the photographic elements that are processed therein, and scale on the equipment used in processing.
In an attempt to avoid the problem of calcium precipitates, it has long been the practice in the photographic art to complex the calcium in an un-ionized form by the use of a sequestering agent. Among the sequestering agents which have been proposed for this purpose are polyphosphates, polycarboxylic acids, hydroxy acids such as gluconic acid, oxyacetic acids such as diglycolic acid, pyridine carboxylic acids, and organophosphonates. However, there are many problems associated with the use of these sequestering agents. Examples of such problems include insufficient sequestering power, a tendency to undergo hydrolysis in the processing solution, a tendency to catalyze the decomposition of some processing agents, and a tendency to undergo reactions leading to the formation of insoluble compounds. Patents relating to the use of sequestering agents in photographic processing compositions include U.S. Pat Nos. 2,172,216, 2,541,470, 2,656,273, 2,875,049, 3,201,246, 3,462,269, 3,746,544, 3,839,045, 3,994,730, 4,083,723, 4,142,895 and 4,264,716 and British Pat. Nos. 712,356, 795,914, 1,251,462, 1,495,504 and 1,496,326.
Of particular importance among the classes of sequestering agents which are used commercially in both color and black-and-white processing compositions--for the purpose of preventing, or at least reducing, the precipitation of calcium salts--are the aminopolycarboxylic acids and the aminopolyphosphonic acids. In some instances, only a single sequestering agent is employed, but it is also well known to use mixtures of two or more sequestering agents, including mixtures of two or more different members of the class of aminopolycarboxylic acids, mixtures of two or more different members of the class of aminopolyphosphonic acids, and mixtures of at least one aminopolycarboxylic acid with at least one aminopolyphosphonic acid.
In a stabilizing bath of the type containing a dye stabilizing agent and an alkanolamine, as described in the aforesaid U.S. patent application Ser. No. 064,633 filed June 22, 1987, it is a particularly difficult problem to reduce or eliminate the formation of unwanted precipitates. This stabilizing bath is used as the final bath in the process and is not washed from the photographic element. Thus, the components of the stabilizing bath remain in the element during the drying step and must be able to withstand the elevated temperatures used in drying. When subjected to such conditions, sequestering agents of either the aminopolycarboxylic acid type or the aminopolyphosphonic acid type tend to degrade and may gradually bring about the formation of yellow stain during storage, with a resulting increase in D min that is highly undesirable. Thus, while they alleviate the problem of precipitates of calcium they cause a staining problem that renders their use impractical.
It is toward the objective of providing a novel stabilizing bath that increases dye stability, avoids precipitate formation, reduces the tendency for sulfurization to occur, and does not cause staining that the present invention is directed.
SUMMARY OF THE INVENTION
In accordance with this invention, a novel stabilizing composition is utilized to provide improved dye stability to photographic color elements which are comprised of a support having thereon at least one hydrophilic colloid layer containing a dye image. The stabilizing composition comprises an aqueous solution of a dye stabilizing agent, an alkanolamine, and polyacrylic acid or a water-soluble salt thereof. The stabilizing composition can be applied to the photographic element in any suitable manner, such as by its use as the final processing step of a conventional photographic process, i.e., the step which immediately precedes the drying step. It provides reduced stain and improved dye stability, is strongly resistant to sulfurization, and exhibits little or no tendency to form precipitates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The stabilizing composition of this invention can be used to provide improved dye stability with any of a wide variety of color photographic elements. Thus, for example, the stabilizing composition can be advantageously employed in the processing of photographic elements designed for reversal color processing or in the processing of negative color elements or color print materials. The stabilizing composition can be employed with photographic elements which are processed in color developers containing couplers or with photographic elements which contain the coupler in the silver halide emulsion layers or in layers contiguous thereto. The photosensitive layers present in the photographic elements processed according to the method of this invention can contain any of the conventional silver halides as the photosensitive material, for example, silver chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide, and mixtures thereof. These layers can contain conventional addenda and be coated on any of the photographic supports, such as, for example, cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polycarbonate film, polystyrene film, polyethylene terephthalate film, paper, polymer-coated paper, and the like.
The photographic elements which are advantageously treated with the stabilizing composition of this invention are elements comprising a support having thereon at least one, and typically three or more, hydrophilic colloid layers containing a dye image. Any of a wide variety of colloids can be utilized in the production of such elements. Illustrative examples of such colloids include naturally occurring substances such as proteins, protein derivatives, cellulose derivatives--e.g., cellulose esters, gelatin--e.g., alkali-treated gelatin (cattle bone or hide gelatin) or acid-treated gelatin (pigskin gelatin), gelatin derivatives--e.g., acetylated gelating, phthalated gelatin and the like, polysaccharides such as dextran, gum arabic, zein, casein, pectin, collagen derivatives, collodion, agar-agar, arrowroot, albumin and the like.
In the production of color photographic images, it is necessary to remove the silver image, which is formed coincident with the dye image. This can be done by oxidizing the silver by means of a suitable oxidizing agent, commonly referred to as a bleaching agent, in the presence of halide ion followed by dissolving the silver halide so formed in a silver halide solvent, commonly referred to as a fixing agent. Alternatively, the bleaching agent and fixing agent can be combined in a bleach-fixing solution and the silver removed in one step by use of such solution.
Color print papers are most commonly processed by use of a bleach-fixing solution. Color negative films are most commonly processed by use of separate bleaching and fixing solutions. The bleaching agent is typically a ferric complex of an aminopolycarboxylic acid, for example, the ferric complex of ethylenediameinetetraacetic acid (EDTA) or the ferric complex of 1,3-propylenediaminetetraacetic acid (PDTA) or a mixture of the ferric complex of EDTA and the ferric complex of PDTA. The fixing agent is typically a thiosulfate, such as sodium thiosulfate or ammonium thiosulfate, or a thiocyanate, such as ammonium thiocyanate, or a mixture of a thiosulfate and a thiocyanate.
Processes employing the stabilizing composition of this invention can vary widely in regard to the particular processing steps utilized. For example, the process can comprise only the two steps of color developing and bleach-fixing, followed by the stabilizing step, or it can comprise the three steps of color developing bleaching, and fixing, followed by the stabilizing step. Alternatively, it can be a color reversal process in which the processing baths utilized are a first developer, a reversal bath, a color developer, a bleach, and a fix, followed by the stabilizing bath.
Any of the well known dye stabilizing agents known to be useful in photographic color processing can be employed in the stabilizing baths of this invention. Particularly useful dye stabilizing agents include hexamethylenetetramine, aliphatic aldehydes such as formaldehyde, paraformaldehyde, acetaldehyde, aldol, crotonaldehyde, propionaldehyde, and the like, and N-methylol compounds such as
dimethylol urea
trimethylol urea
dimethylol guanidine
trimethylol melamine
tetramethylol melamine
pentamethylol melamine
hexamethylol melamine
1,3-dimethylol-5,5-dimethyl hydantion and the like.
In addition to the dye stabilizing agent, the stabilizing baths of this invention contain an alkanolamine and polyacrylic acid or a water-soluble salt thereof. The use of alkanolamines in such baths is based on the unexpected discovery--disclosed in the aforesaid U.S. patent application Ser. No. 64,633 filed June 22, 1987,--that they function effectively to retard sulfurization and thereby make it feasible to tolerate the carry-in of thiosulfate fixing agent that occurs in processes that do not use a wash step after the fixing or bleach-fixing step. The mechanism whereby the alkanolamine causes this result is not clearly understood.
The term "alkanolamine", as used herein, refers to an amine in which the nitrogen atom is directly attached to a hydroxyalkyl group, i.e., the amine comprises an >N--X--OH group where X is alkylene. The radicals attached to the free bonds in the >N--X--OH group can be hydrogen atoms or organic radicals, e.g., unsubstituted hydrocarbon radicals or substituted hydrocarbon radicals. They are preferably hydrocarbyl radicals of 1 to 12 carbon atoms, for example, alkyl, aryl, alkaryl or aralkyl radicals.
Alkanolamines which are preferred for use in the stabilizing baths of this invention are compounds of the formula: ##STR1## wherein R 1 is an hydroxyalkyl group of 2 to 6 carbon atoms and each of R 2 and R 3 is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms, an hydroxyalkyl group of 2 to 6 carbon atoms, a benzyl radical, or a ##STR2## wherein n is an integer of from 1 to 6 and each of X and Y is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms or an hydroxylalkyl group of 2 to 6 carbon atoms. Alkanolamines which are especially preferred are compounds of the formula: ##STR3## wherein R 4 is an hydroxyalkyl group of 2 to 4 carbon atoms and each of R 5 and R 6 is an alkyl group of 1 to 4 carbon atoms or an hydroxyalkyl group of 2 to 4 carbon atoms. Typical examples of alkanolamines which can be used in the stabilizing baths of this invention include:
ethanolamine
diethanolamine
triethanolamine
di-isopropranolamine
2-methylaminoethanol
2-ethylaminoethanol
2-dimethylaminoethanol
2-diethylaminothanol
1-diethylamino-2-propanol
3-diethylamino-1-propanol
3-dimethylamino-1-propanol
isopropylaminoethanol
3-amino-1-propanol
2-amino-2-methyl-1,3-propanediol
ethylenediamine tetraisopropanol
benzyldiethanolamine
2-amino-2-(hydroxymethyl)-1,3-propandiol and the like.
The polyacrylic acid or water-soluble salt thereof which is used, in accordance with this invention, as a calcium-controlling agent in a stabilizing bath is a well known material. It is available commercially from B. F. GOODRICH COMPANY in a number of forms of differing molecular weight under the trademarks GOODRITE K-702, GOODRITE K-722, GOODRITE K-732, GOODRITE K-752 and GOODRITE K-7028, and is commonly used for scale control in boilers and cooling water systems. It can be represented by the formula ##STR4## where n equals 10 to 70. For the purposes of this invention, the polyacrylic acid can be utilized as such or in the form of a water-soluble salt, such as the sodium or potassium salts.
Polyacrylic acid polymers are polyelectrolytes, that is, ion-containing macromolecules which exhibit the combined properties of polymers and of electrolytes. Applicant is not certain of the mechanism whereby they function in his invention, and does not wish to be bound by any theoretical explanation of such mechanism. It is believed that they function to both complex calcium and to alter the crystalline form of calcium precipitates. The polyacrylic acid greatly reduces the amount of precipitate formation that would otherwise occur in the stabilizing bath and has the further advantage that precipitates which do form tend to be of a type which does not form a tenaciously adhering scale.
The use of polyelectrolytes such as hydrolyzed polymaleic anhydrides, salts of polymeric carboxylic acids, and polyacrylamides in photographic processing compositions has been proposed heretofore in Research Disclosure, Item 22937, No. 229, May 1983 entitled "Polyelectrolytes As Calcium Controlling Agents In Photographic Processing Solutions" (Research Disclosure is published by Kenneth Mason Publications Ltd., 8 North Street, Emsworth, Hampshire, PO 107 DD United Kingdom). There is no suggestion in the prior art, however, to use polyacrylic acid in stabilizing baths which contain both a dye stabilizing agent and an alkanolamine, to thereby avoid precipitate formation without causing a staining problem.
Other additives can also be incorporated in the stabilizing bath of this invention with beneficial results. Examples of useful additives include wetting agents, buffering agents and biocides. Wetting agents are particularly useful when processing color negative films to avoid water spotting. Organosiloxane wetting agents are especially beneficial and their stability in the stabilizing bath of this invention is enhanced by the presence of the alkanolamine. Biocides are useful to prevent microbial growth in both processes for color films and processes for color papers. A particularly useful class of biocides for this purpose are the thiazole compounds, especially isothiazolines such as 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-octyl-4-isothiazolin-3-one and 5-chloro-N-methyl-4-isothiazolin-3-one.
The ingredients utilized in making up the stabilizing composition of this invention can be used in any suitable amount and the optimum amount of each will vary widely depending on a number of factors such as the particular compounds employed, the manner of treating the photographic element with the stabilizing composition, and the particular type of photographic element which is to be treated.
Typically, the dye stabilizing agent is used in an amount of from about 0.1 to about 10 grams per liter of stabilizing solution, and more preferably in an amount of from about 0.4 to about 2 grams per liter; the alkanolamine is used in an amount of from about 0.5 to about 20 grams per liter of stabilizing solution, and more preferably in an amount of from about 1 to about 5 grams per liter, and the polyacrylic acid or water-soluble salt thereof is used in an amount of from about 0.01 to about 1.0 grams per liter of stabilizing solution, and more preferably in an amount of from about 0.02 to about 0.05 grams per liter. The stabilizing solution is preferably employed at a pH in the range of from about 6 to about 10, and more preferably at a pH in the range of from 7 to 9.
The polyacrylic acid is used at very low concentrations in the stabilizing bath of this invention (compare the suggested use of about 0.01 to about 1.0 grams per liter with the suggested use of about 5 to about 20 grams per liter in Research Disclosure, Item 22937, No. 229, May 1983.) Use of such low concentrations is believed to materially contribute to the ability of the processed photographic element to withstand the drying step and to remain essentially free from stain upon long term storage.
Application of the stabilizing composition to a photographic element is conveniently accomplished by immersion of the element in the stabilizing bath but can be carried out by other means such as surface application. The time and temperature employed for the stabilization treatment can vary widely. For example, suitable times are typically in the range of from about 0.1 to about 3 minutes, more preferably from about 0.5 to about 1.5 minutes, while suitable temperatures are typically in the range of from about 20° C. to about 50° C., more preferably from about 30° C. to about 40° C. While the stabilizing bath of this invention is typically used as the final bath in a photographic processing cycle, it can also be used as a post-processing treatment. For example, it can be used to treat processed elements in which the dye images have already begun to deteriorate, in order to reduce further deterioration.
The invention is further illustrated by the following examples.
A stabilizer concentrate was prepared as follows:
______________________________________ ConcentrationIngredient (g/L)______________________________________Water 608Formalin (a 37% by weight 115solution of formaldehyde)Triethanolamine 119.4Organosilicone surfactant 106Isothiazolone microbicide 17.4______________________________________
In order to evaluate the propensity for a precipitate of calcium carbonate to form in the stabilizer, tests were conducted in which 11.8 milliliters of the aforesaid concentrate were added to one liter of water to which 0.4 grams of CaCl 2 .2H 2 O and 0.6 grams of KHCO 3 had been added to simulate hard water.
Varying amounts of polyacrylic acid polymers of differing molecular weight were added to the simulated hard water, as indicated below, to determine the effect on precipitate formation. The polyacrylic acid was added to the water prior to adding the stabilizer concentrate.
______________________________________ Amount ofTest Polymer Appearance ofNo. Polymer (g/L) Stabilizer______________________________________1 None -- Immediate Precipitation2 GOODRITE K-702 0.02 Hazy3 GOODRITE K-722 0.10 Precipitate4 GOODRITE K-732 0.02 Clear5 GOODRITE K-752 0.02 Clear6 GOODRITE K-752 0.10 Clear7 GOODRITE K-752 0.50 Clear8 GOODRITE K-752 1.0 Clear9 GOODRITE K-7028 0.02 Clear______________________________________
The data reported above indicate that use of polyacrylic acid in an extremely small concentration is effective in avoiding precipitate formation.
Use of a stabilizing bath in accordance with this invention has been found to provide the following advantages:
(1) excellent image stability,
(2) elimination of elemental sulfur precipitation,
(3) no adverse effects on drying such as scum formation or water spots,
(4) no biological growths, and
(5) no precipitation of calcium salts. Use of polyacrylic acid for the purpose described herein effectively eliminates calcium carbonate precipitation--and thereby provides a stabilizer that is suitable for use in hard water areas without demineralization of water--with no adverse effect on other stabilizer performance criteria.
In contrast with the results obtained in using polyacrylic acid, when common sequestering agents such as ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid and diaminopropanol tetraacetic acid were added to the stabilizing bath to prevent the formation of calcium precipitates, accelerated image stability tests showed a significant increase in stain.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A stabilizing bath which provides reduced stain and enhanced dye stability for photographic color elements which are processed therein is comprised of a dye stabilizing agent, an alkanolamine, and polyacrylic acid or a water-soluble salt thereof. The stabilizing bath is used as a final processing bath which follows treatment of the element in a fixing or bleach-fixing bath containing a thiousulfate fixing agent. The alkanolamine functions to prevent the precipitation of sulfur resulting from carryover of the thiosulfate fixing agent into the stabilizing bath, while the polyacrylic acid or water-soluble salt thereof functions to avoid the formation of unwanted precipitates.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 11/095,419, filed Mar. 31, 2005 now U.S. Pat. No. 7,105,743, which is a continuation of application Ser. No. 10/215,583, filed Aug. 9, 2002, now U.S. Pat. No. 6,896,547.
BACKGROUND OF THE INVENTION
The present invention relates generally to telecommunications and multimedia junctions, and particularly to outlet boxes for facilitating telecommunications and multimedia-type junctions and connections within a work space or other place where space is at a premium.
Outlet boxes designed for the work place need to account for potentially tight space considerations. In particular, providing access to the connectors housed therein from a variety of angles is often advantageous, as seen for example in U.S. Pat. No. 5,947,765. This is especially true of outlet boxes intended to be wall-mounted or otherwise disposed within a visible and usable work space, as opposed to when outlet boxes are mounted in more discreet locations, such as when they are underfloor-mounted or when they reside above a false ceiling. The space limitations associated with a work space might, for example, yield situations where a particular cable only has sufficient length to reach one particular side of an outlet box and/or from one particular angle. Also, fiberoptic cabling generally must avoid sharp turns or bends, and often has a “minimum bend radius” associated with particular cable. Standard outlet boxes having traditional configurations sometimes fail to accommodate the demands of fiberoptic cabling by requiring sharp turns of the cabling in order to plug into particular connectors or by having sharp corners on the perimeter of the box.
Many different types of outlet boxes exist, but a significant shortcoming of many prior art designs is that they do not support a large number of “gravity-feed” connections, connections where a cable approaches the outlet box at an upward angle or direction such that gravity's effect on the cable is more minimal, especially with regard to adversely affecting the bend radius near the outlet box. Sometimes even connectors that provide “gravity-feed” connections, such as the ones shown in U.S. Pat. No. 5,947,765, fail to provide sufficient clearance for the cables entering the “gravity-feed” connectors to avoid bend radius problems due to the potential proximity of other office equipment and the like.
Other outlet boxes fail to provide for easy access to the interior thereof, such as to access cable or switch particular connectors into and out of particular bays of the outlet box. This can limit the adaptability of the outlet box for particular telecommunications or multimedia applications. Still other outlet boxes fail to provide cable slack management features, such as bend radii, inside the boxes. Such failure may encourage deleterious cable kinking and tangling within the boxes. Some boxes may also have connectors oriented to make plugs difficult to insert into or remove from the connectors, especially when adjacent connectors have plugs inserted therein. Still other boxes may require a fiberoptic cable to be twisted to enable a plug to be inserted into its connectors. Twisting of fiberoptic cables, especially when coupled with other stresses, may have detrimental effects on the signals being passed through them. Thus, there is a need for an improved multimedia outlet box.
SUMMARY OF THE INVENTION
Disclosed and claimed herein is an outlet box for addressing the above-identified shortcomings of prior devices.
In an embodiment of the invention, there is provided an outlet box having a base including a rear surface of the outlet box, a cover including a front surface of the outlet box, the cover being configured for engagingly fitting over the base, an intermediate portion extending from one or both of the base and cover and extending generally between the rear surface and the front surface, whereby the cover, the base, and the intermediate portion cooperatively define an interior of the outlet box when the cover and the base are engagingly fitted together, the intermediate portion including a pair of opposed inwardly inclined portions and a pair of set-off portions extending from the inner more ends of the inwardly inclined portions, at least one of the inclined portions including an aperture therein, and a connector disposed within the base, the connector having an opening for receiving a plug.
In another embodiment of the invention, there is provided an outlet box having a base including a rear surface of the outlet box, a cover including a front surface of the outlet box, the cover being configured for engagingly fitting over the base, an intermediate portion extending from one or both of the base and cover and extending generally between the rear surface and the front surface, whereby the cover, the base, and the intermediate portion cooperatively define an interior of the outlet box when the cover and the base are engagingly fitted together, the intermediate portion including a pair of opposed inwardly inclined portions, at least one of the inclined portions including an aperture therein, and a connector disposed within the base, the connector having an opening configured for receiving a latched plug, the opening being oriented such that when the latched plug is disposed within the connector, the latch extends toward the front surface of the outlet box.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of an assembled outlet box in accordance with an embodiment of the invention.
FIG. 2 is an exploded disassembled perspective view of the outlet box of FIG. 1 .
FIG. 3 is a top plan view of the base portion of the outlet box of FIG. 1 .
FIG. 4 is a perspective view of the underside of the base portion of the outlet box of FIG. 1 .
FIG. 5 is an exploded disassembled perspective view of an outlet box in accordance with an alternate embodiment of the invention.
FIG. 6 is a perspective view of the outlet box of FIG. 5 , wherein the outlet box is assembled.
DESCRIPTION OF PREFERRED EMBODIMENTS
A modern office communication network can include a variety of voice, data, and video cables which connect, for example, central office telephone equipment to individual telephones and main frame computers to remote personal computers. The terminal ends of these cables are provided with appropriate connectors for selective interconnection to remote equipment. The present invention provides a means to securely mount a variety of these connectors, possibly from different media, in one enclosure for subsequent connection to cables connected to various office equipment.
In accordance with an embodiment of the invention, there is provided a 12-port outlet box 10 , as shown in FIGS. 1–4 . The outlet box 10 is shown in assembled form in FIG. 1 and disassembled form in FIG. 2 . As seen in these figures, the box 10 includes a cover 12 that snappingly engages with, and is disengageable from, a base 14 . The cover includes the front surface 16 of the box and a generally perpendicular side wall 18 that contributes to the intermediate portion 19 of the box when the cover and base are mutually engaged. The base includes the rear surface 20 of the box and a generally perpendicular side wall 22 upstanding therefrom that, like the side wall 18 of the cover, contributes to the intermediate portion 19 of the box when the cover and base are mutually engaged.
As best seen from the plan view of FIG. 3 , the base and whole box have a distinctive geometry, including a top portion 30 , a pair of inwardly inclined portions 32 extending inwardly from the outer more ends 33 of the top portion, a pair of set-off portions 34 extending from the inner more ends 35 of the inclined portions, and a bottom portion 36 extending from and between the opposite ends of the set-off portions.
In a preferred embodiment of the invention, the set-off portions 34 are generally perpendicular to the top portion 30 , while the bottom portion 36 is generally parallel to the top portion 30 , though these relationships need not exist within the context of the invention.
In a preferred embodiment of the invention, the outer more ends 33 of the inwardly inclined portions 32 and the top portion 30 meet at rounded corners 38 . Such rounded corners provide bend radius control for fiberoptic cables if they are wrapped around that portion of the box. Sharper corners might cause damage to fiberoptic or other more fragile cables that might inhibit signal transmission thereover.
In a preferred embodiment of the invention, the inclined portions 32 are at an angle of about 45 degrees relative to the top portion 30 , and/or relative to a vertical orientation, but this angle may vary significantly.
As seen in FIGS. 2 and 3 , the base 14 includes bays for permitting the insertion into the box of various jack/connector configurations. For example, up to twelve single-position jacks may be accommodated along the interior side of the inwardly inclined portions, six on each side. Alternatively, banks of jacks may be used, such as a single bank of six adjacent jacks or two adjacent banks of three jacks along each inwardly inclined portion. The connectors/jacks may or may not be of identical type, as any combination can be used in the multimedia box. FIG. 2 , for example, shows fiberoptic connectors and standard telephone jacks in side-by-side configuration.
In a preferred embodiment of the invention, the base includes an inlet hole 24 generally in the center thereof for permitting cable to enter the interior of the box there through. In a preferred embodiment, the shape of the hole allows for the cables to flow to the connector positions more easily, and thereby deters unwanted slack within the interior of the box and unnecessary redirections that may increase the chances of damage to fibers or signal degradation.
In a preferred embodiment of the invention, break-out portions 42 are found along the intermediate portion 19 of the box to function as alternate inlets or outlets for cables, especially via means such as raceway. FIG. 2 shows such a break-out in the top portion 30 of the box. Notches 44 may be used to facilitate the break-outs.
In a preferred embodiment of the invention, the base includes mounting holes or bosses 45 that are compatible with NEMA standard single gang and double gang boxes.
In a preferred embodiment of the invention, the base includes spooling structures to facilitate cable slack storage. In the shown embodiment, some of the spooling structures 47 are attached to the bosses 45 . In the shown embodiment, the spooling pattern is generally a figure-8. The figure-8 pattern allows for the fiber slack to be spread out over a larger area, thereby avoiding a large bundle of fibers residing about a single diameter.
In a preferred embodiment of the invention, the base includes one or more cable tie down structures 46 to facilitate the bundling, management, and/or routing of cables within the interior of the box.
In a preferred embodiment of the invention, the base includes one or more breakouts 48 for an MPO adapter to be inserted.
In a preferred embodiment of the invention, the base includes one or more magnet pockets 49 for retaining magnets as an alternate method for mounting the box on a surface. The box could alternatively or additionally be supplied with double-sided adhesive foam tape for mounting.
In a preferred embodiment of the invention, the base includes labeling areas 52 for identifying the corresponding ports. Such areas 52 may also act as screw covers, hiding screws that secure the cover to the base.
In the shown embodiment, the base contains four notches to permit the cover to snappingly engage the base. At the notches are screwdriver release pads to facilitate removing the cover from the base.
As can be seen from the figures, when the shown embodiment is installed in the orientation shown in FIGS. 1 and 3 upon a wall or other vertical surface, the inwardly inclined portions of the box facilitate “gravity-feed” connections in that the plugs approach the connectors at an upward angle. Thus, the cables extending from the plugs do not encounter the same degree of kinking near the plug due to the weight of the cables themselves, as opposed to cables approaching horizontally, downwardly, or at a downward angle. Rather, the more upwardly the approach, the less kinking that is caused.
Importantly, as best seen in FIGS. 1 and 3 , the rectangular section of the box, generally defined by set-off portions 34 and bottom portion 36 , sets the box off from any furniture or other obstructions that may be located just below the box along its vertical mounting surface. Without such a set-off, cables approaching the box at an upward angle would likely encounter kinking issues against the furniture since the cable would have very little distance in which to turn a significant angle.
Thus, the shown embodiment of the invention includes a trapezoidal section defined primarily by the inclined portions 32 and the top portion 30 residing just above a rectangular (or other quadrilateral) section defined by the set-off portions 34 and the bottom portion 36 . The rectangular section provides set-off and thereby helps prevent breaking the minimum bend radius for optical cables. Additionally, the section providing set-off also prevents the potential problem of difficulty or impossibility of inserting plugs into gravity-feed connectors wherein insufficient space is provided between the connectors and office obstructions, such as desks, cabinets, book cases, computer monitors, wall outlets, thermostats, and the like. Thus, such obstructions can cause damage to optical cable or make difficult or impossible the insertion of plugs when no set-off section is provided.
The rectangular set-off section of the shown embodiment need not actually be rectangular and the set-off portions need not actually be straight or mutually parallel, as any similar set-off structure could perform similar functions, and such similar structure is considered to be alternative within the context of the invention.
In accordance with an alternate embodiment of the invention, there is provided a 24-port outlet box, as shown in FIGS. 5–6 . The outlet box 110 is shown in assembled form in FIG. 6 and disassembled form in FIG. 5 . As seen in these figures, the box 110 includes a cover 112 that snappingly engages with, and is disengageable from, a base 114 . The cover includes the front surface 116 of the box and a generally perpendicular side wall 118 that contributes to the intermediate portion of the box when the cover and base are mutually engaged. The base includes the rear surface 120 of the box and a generally perpendicular side wall 122 upstanding therefrom that, like the side wall 118 of the cover, contributes to the intermediate portion of the box when the cover and base are mutually engaged.
Preferably, base 14 of the 12-port embodiment and base 114 of the 24-port embodiment are identical, and either cover 12 or cover 112 may be used with the common base, depending on whether the 12-port or 24-port embodiment of the outlet box is needed for a particular application.
In the shown 24-port embodiment, a bridge 124 is snapped into or otherwise engaged with structure of the base 114 to expand the capacity of the box from 12 ports to 24 ports. To provide space for the additional row of connectors, the cover 112 is deeper than its 12-port cover counterpart. The cut-away portion 140 of the cover side wall 118 is also correspondingly larger than its 12-port cut-away portion counterpart to accommodate the bridge and multiple rows of connectors. The 24-port embodiment simply permits more like-sized connectors to be housed within the outlet box, while providing the same flexibility relating to different types, configurations, and orientations of connectors and corresponding plugs. As seen in FIG. 6 , for example, fiberoptic connectors can adjoin telephone jacks in various combinations.
In both shown embodiments, at least some of the connectors have openings configured for receiving a latched plug 54 , the openings being oriented such that when corresponding latched plugs 54 are disposed within the connectors, the latches 56 extend toward the front surface of the outlet box. This orientation has the benefit that when various plugs 54 are located within adjacent connectors, it is easier to activate the latch 56 to permit disengagement of one of the plugs 54 when the latch 56 is not located between the adjacent plugs 54 , as it would be if the connectors and plugs 54 were rotated 90 degrees in either direction. Additionally, such an orientation of the connectors may require less twisting of fiberoptic cables resulting from mating with the connectors. The decreased twisting decreases the risk of damaging the fiberoptic cables from an overstressed condition.
The disclosed invention provides an improved multimedia outlet box. It should be noted that the above-described and illustrated embodiments of the invention are not an exhaustive listing of the forms an outlet box in accordance with the invention could take; rather, they serve as exemplary and illustrative of preferred embodiments of the invention as presently understood. Many other forms of the invention are believe to exist. Examples inexhaustively include boxes wherein the inclined portions form angles other than 45 degrees relative to other portions of the box and/or to a vertical orientation, boxes wherein the set-off portions are not mutually parallel or parallel or perpendicular to any particular portions of the box or a vertical orientation, boxes wherein the top portion includes multiple segments not necessarily coplanar or collinear with each other, and boxes wherein the number of connectors housed is greater or lesser than 12 or 24, or the number of rows of connectors is greater than two.
The invention is defined by the following claims.
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An outlet box is disclosed. The outlet box has a base including a rear surface of the outlet box, and a cover including a front surface of the outlet box. The cover is configured to engagingly fit over the base. An intermediate portion extends from one or both of the base and cover and extends generally between the rear surface and the front surface. The cover, the base, and the intermediate portion cooperatively define an interior of the outlet box when the cover and the base are engagingly fitted together. The intermediate portion includes a pair of opposed inwardly inclined portions and a pair of set-off portions extending from the inner more ends of the inwardly inclined portions, and at least one of the inclined portions includes an aperture therein. A connector is disposed within the base, and the connector has an opening for receiving a plug.
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This application is a division of Ser. No. 08/429,730, filed Apr. 27, 1995, now U.S. Pat. No. 5,591,352.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to cold cathode field emission displays, more particularly high resolution field emission displays.
(2) Description of the Prior Art
Cold cathode electron emission devices are based on the phenomenon of high field emission wherein electrons can be emitted into a vacuum from a room temperature source if the local electric field at the surface in question is high enough. The creation of such high local electric fields does not necessarily require the application of very high voltage, provided the emitting surface has a sufficiently small radius of curvature.
The advent of semiconductor integrated circuit technology made possible the development and mass production of arrays of cold cathode emitters of this type. In most cases, cold cathode field emission displays comprise an array of very small conical emitters, each of which is connected to a source of negative voltage via a cathode conductor line (or column). Another set of conductive lines (called gate lines) is located a short distance above the cathode columns at an angle (usually 90°) to them, intersecting with them at the locations of the conical emitters or microtips, and connected to a source of positive voltage. Both the cathode and the gate line that relate to a particular microtip must be activated before there will be sufficient voltage to cause cold cathode emission.
The electrons that are emitted by the cold cathodes accelerate past openings in the gate lines and strike an electroluminescent panel that is located a short distance above the gate lines. In general, even though the local electric field in the immediate vicinity of a microtip is in excess of 1 million volts/cm., the externally applied voltage is only of the order of 100 volts. However, even a relatively low voltage of this order can obviously lead to catastrophic consequences, if short circuited.
The early prior art in this technology used external resistors, placed between the cathode or gate lines and the power supply, as ballast to limit the current in the event of a short circuit occurring somewhere within the display. While this approach protected the power supply, it could not discriminate between individual microtips on a given cathode column or gate line. Thus, in situations where one (or a small number) of the microtips is emitting more than its intended current, no limitation of its individual emission is possible. Such excessive emission can occur as a result of too small a radius of curvature for a particular microtip or the local presence of gas, particularly when a cold system is first turned on. Consequently the more recent art in this technology has been directed towards ways of providing individual ballast resistors, preferably one per pixel.
The approach favored by Borel et al. (U.S. Pat. No. 4,940,916 July 1990) is illustrated in FIG. 1. This shows a schematic cross-section through a single pixel. As already discussed, current to an individual microtip 2 is carried by a cathode line 1 and a gate line 4. However, a high resistance layer 3 has been interposed between the base of the microtip and the cathode line, thereby providing the needed ballast resistor. While this invention satisfies the objective of providing each microtip with its own ballast resistor, as well as not reducing the resolution of the display, it has a number of limitations.
The resistivity that layer 3 will need in order to serve as a ballast resistor is of the order of 5×10 4 ohm cm. This significantly limits the choice of available materials. Furthermore, sustained transmission of current across a film is substantially less reliable than transmission along a film. The possibility of failure as a result of local contamination or local variations in thickness is much greater for the first case. Consequently, later inventions have focussed on providing individual ballast resistors wherein current flows along the resistive layer, rather than across it.
Kane (U.S. Pat. No. 5,142,184 August 1992) used semiconductor integrated circuit technology to generate his cold cathode display so that individual ballast resistors could be provided in the same way that resistors are provided within integrated circuits in general. This approach meets the requirement of current transmission along, rather than across, the resistive layer but makes for a more expensive system since an additional mask and diffusion step are required. Furthermore, additional space must be made available for the diffused resistors, which lie on either side of the cathode columns, thereby decreasing the resolution of the system.
The approach taken by Meyer (U.S. Pat. No. 5,194,780 March 1993) utilizes a cathode distribution mesh and is illustrated in FIG. 2. This shows, in plan view, a portion of a single cathode line which, instead of being a continuous sheet, has been formed into a network of lines 15 intersecting with lines 16. A resistive layer 17 has been interposed between the mesh and the substrate (not shown here). Array of microtips 12 (as indicated big the arrow 12) have been formed on the resistive layer and located within the interstices of the mesh. A single gate line intersects the cathode distribution mesh, and current from the mesh must first travel along resistive layer 17 before it reaches the microtips. An important disadvantage of this approach is that the presence of the mesh limits the resolution of the display. Another disadvantage is that the values of the ballast resistors associated with the various microtips vary widely because of the geometry of this design.
SUMMARY OF THE INVENTION
It has been an object of the present invention to provide a cold cathode field emission display whose resolution is not limited by the provision of individual ballast resistors for each pixel or by the wiring system used to deliver voltage to the cold cathodes.
A further object of the invention has been to provide individual ballast resistors that have high reliability and are capable of meeting tight tolerances.
These objects have been achieved by providing additional layers beneath the cold cathodes arrays so that said resistors and voltage delivery systems may be located directly below the cold cathode arrays instead of alongside of them. Six different embodiments of the invention are described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrate prior art that teaches the technology of built-in ballast resistors for cold cathode displays.
FIGS. 3A and B show a first embodiment of the invention based on a distributed ballast resistor and a cathode distribution mesh.
FIGS. 4A and B show a second embodiment of the invention based on a serpentine thin film resistor and a cathode distribution line.
FIG. 5 shows a third embodiment of the invention based on a spiral thin film resistor and a cathode distribution line.
FIGS. 6A and B show a fourth embodiment of the invention based on a distributed ballast resistor and a cathode distribution plane.
FIGS. 7A and B show a fifth embodiment of the invention based on a serpentine thin film resistor and a cathode distribution plane.
FIGS. 8A and B show a sixth embodiment of the invention based on a spiral thin film resistor and a cathode distribution plane.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is aimed at providing individual ballast resistors for the groups of microtips that comprise pixels without sacrificing the resolution of the overall display. This has been achieved by placing the ballast resistors and cathode voltage supply system (cathode columns or distribution mesh) underneath the microtips instead of alongside them.
Referring now FIG. 3A. This shows, in schematic cross-section, a first embodiment of the present invention. Resistive layer 32 has been deposited onto insulating substrate 31. Cathode distribution mesh 33 (seen end-on in the figure) sits above, beneath, or in, and makes contact with, resistive layer 32. Dielectric layer 34 has been deposited over layers 32 and 33 and cathode column 35 (seen end-on) lies over layer 34. Via hole 36 allows material from layer 35 to make contact with resistive layer 32. Microtips such as 37 rest on cathode column 35 and extend through openings in gate line 38 which is separated from layer 35 by second dielectric layer 39. Note that it is necessary to planarize the upper surface of layer 35 prior to the placement of the microtips. We have found the most effective way to achieve this to be by means of Chemical Mechanical Polishing (CMP). The CMP process comprises the application of a chemical etchant, which loosens the surface, in combination with a fine abrasive slurry that removes the modified surface as it is undermined.
FIG. 3B is a partial plan view of the structure illustrated in FIG. 3A. It is readily apparent that, other things being equal, the structure of FIG. 3B can be made smaller than the prior art structure illustrated in FIG. 2. The size of cathode distribution mesh 18 in FIG. 2 is limited by how close lines 15 and 16 can come to the array of microtips as indicated by the arrow 12) and still provide adequate resistance in series with them. Furthermore, the closer lines 15 and/or 16 come to the array of microtips 12 the greater will be the disparity in ballast resistor values associated with these microtips. By contrast, all microtips in FIGS. 3 are associated with the same value of ballast resistance and the size of the cathode distribution mesh can be reduced to less than that of the cathode columns, eliminating it as a factor in limiting the overall resolution.
Preferred materials for manufacturing this embodiment have included silicon, silicon/chrome alloy, indium tin oxide, and tantalum nitride for the resistive layer, laid down to provide a sheet resistance in the range of from 10 7 to 10 9 ohms/square and silicon oxide, aluminum oxide, silicon nitride, iron oxide, indium oxide, stannous oxide, and tantalum oxide for the dielectric layers.
FIG. 4A is a schematic cross-section of a second embodiment of the present invention in which a more conventional aspect ratio for the ballast resistor has been used. Resistor 42 is a thin film resistor that has been deposited and patterned on substrate 41. One end of each resistor is connected to a cathode distribution line such as 43 (seen end-on) while the other end is connected to a cathode column (also seen end-on) through via hole 46. FIG. 4B is a plan view of part of FIG. 4A.
This embodiment makes the value of the ballast resistor easier to control and allows resistive layers having lower sheet resistance to be used. Also, since only a single line is needed for the voltage supply (as opposed to the multiple lines of a mesh), this embodiment occupies less space than the embodiment illustrated in FIG. 3.
FIG. 5 is a plan view of a third embodiment that is a variant of the embodiment illustrated in FIGS 4. In FIG. 4 the resistor followed a serpentine path in going from the cathode distribution line to the via hole. In FIG. 5, the path of resistor 52 can be seen to be a spiral that begins at the cathode distribution line 53 and then spirals inwards till it reaches the via hole 56 at the center.
Preferred materials for manufacturing this embodiment have included silicon, silicon/chrome alloy, indium tin oxide, and tantalum nitride for the resistive layer, laid down to provide a sheet resistance in the range of from 10 7 to 10 9 ohms/square and silicon oxide, aluminum oxide, silicon nitride, iron oxide, indium oxide, stannous oxide, and tantalum oxide for the dielectric layers.
FIG. 6A shows a schematic cross-section of a fourth embodiment of the present invention. Conductive layer 60 has been deposited on substrate 61 and has been covered by dielectric layer 64 on which resistive layer 62 lies. Cathode distribution mesh 67, comprised of the same material as resistive layer 62, connects conductive layer 60 to resistive layer 62. Dielectric layer 69 corresponds to dielectric layer 34 in FIG. 3A and the parts of the structure that lie above layer 69 correspond to the parts that lie above layer 34 in FIG. 3A. FIG. 6B is a plan view of part of FIG. 6A showing cathode distribution mesh 67 and via hole 66. As already mentioned, a CMP process is employed to planarize the surface prior to the formation of the microtips.
Preferred materials for manufacturing this embodiment have included silicon, silicon/chrome alloy, indium tin oxide, and tantalum nitride for the resistive layer, laid down to provide a sheet resistance in the range of from 10 7 to 10 9 ohms/square and silicon oxide, aluminum oxide, silicon nitride, iron oxide, indium oxide, stannous oxide, and tantalum oxide for the dielectric layers.
FIGS. 7A and 7B and FIGS. 8A and 8B show fifth and sixth embodiments, respectively, that bear the same relationship to FIGS. 6 as do FIGS. 4 and 5 to FIGS. 3. The additional third dielectric layer that is a feature of the fifth and sixth embodiments allows for an even more compact design. Note that layer 71 in FIG. 7 represents a single cathode line. Said cathode line connects to one end of thin film resistor 72 through via hole 77, the other end of resistor 72 being connected to cathode column 75 through via hole 76, as in the earlier embodiments.
Preferred materials for manufacturing this embodiment have included silicon, silicon/chrome alloy, indium tin oxide, and tantalum nitride for the resistive layer, laid down to provide a sheet resistance in the range of from 10 7 to 10 9 ohms/square and silicon oxide, aluminum oxide, silicon nitride, iron oxide, indium oxide, stannous oxide, and tantalum oxide for the dielectric layers.
While the invention has been particularly shown and described with reference to the preferred embodiments described above, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
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The object of the present invention is to provide a cold cathode field emission display whose resolution is not limited by the provision of individual ballast resistors for each pixel or by the wiring system used to deliver voltage to the cold cathodes. This has been achieved by providing additional layers beneath the cold cathodes arrays so that said resistors and voltage delivery systems are located directly below the cold cathode arrays instead of alongside of them. Six different embodiments of the invention are described.
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RELATED APPLICATIONS
[0001] The present application is related to commonly owned and assigned application Ser. Nos.:
[0002] Ser. No. 09/730,864, entitled System and Method for Configuration, Management and Monitoring of Network Resources, filed Dec. 6, 2000;
[0003] Ser. No. 09/730,680, entitled System and Method for Redirecting Data Generated by Network Devices, filed Dec. 6, 2000;
[0004] Ser. No. 09/730,863, entitled Event Manager for Network Operating System, filed Dec. 6, 2000;
[0005] Ser. No. 09/730,671, entitled Dynamic Configuration of Network Devices to Enable Data Transfers, filed Dec. 6, 2000;
[0006] Ser. No. 09/730,682, entitled Network Operating System Data Directory, filed Dec. 6, 2000;
[0007] Ser. No. 09/799,579, entitled Global GUI Interface for Network OS, filed Mar. 6, 2001;
[0008] Ser. No. 09/942,834, entitled System and Method for Generating a Configuration Schema, filed Aug. 29, 2001,
[0009] Ser. No. 09/942,833, entitled System and Method for Modeling a Network Device's Configuration, filed Aug. 29, 2001,
[0010] Ser. No. 10/037,892, entitled System and Method for Evaluating Effectiveness of Network Configuration Management Tools, filed Oct. 23, 2001,
[0011] Ser. No. 09/991,764, entitled System and Method for Generating a Representation of a Configuration Schema, filed Nov. 26, 2001, and
[0012] Ser. No. 10/145,868, entitled System and Method for Transforming Configuration Commands, filed May 15, 2002,
[0013] all of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0014] The present invention relates to network device management. In particular, but not by way of limitation, the present invention relates to systems and methods for maintaining network device configurations and/or generating network device configurations.
BACKGROUND OF THE INVENTION
[0015] Network devices such as routers, switches and optical devices are becoming increasingly more complicated. Typical network devices now require thousands of lines of specialized configuration instructions to operate properly. Unlike most software applications, the instructions that operate network devices can be changed on a frequent basis. The nature of network devices often requires that each version of a device's configuration be stored. This can be used to facilitate returning the network back to a known good state in the event of a configuration failure or other network problem. Because changes are so frequent, sizable repositories of old configurations are generated for each device. When these sizable repositories are accumulated across the thousands of network devices that frequently make up a network, cumbersome, inefficient repositories are created. In some cases, these repositories are so large that they are not useful.
[0016] Present network architecture generally requires that configuration instructions and the capabilities of a network device (referred to as “configuration knowledge”) be stored together as an atomic unit. This single-data-model approach has proven to be difficult to maintain in sophisticated networks. When network administrators, for example, archive only the configuration instructions, the configuration knowledge that was used to generate those configuration instructions is lost, and when the network administrators attempt to archive both the configuration instructions and the configuration knowledge, the size of the archived file becomes too large because the knowledge used to generate the configuration is many times the size of the actual configuration. Moreover, for a given version of the device, the device knowledge is invariant, e.g., the operating system and hardware for the network device are the same. Thus, repeatedly archiving the configuration knowledge is wasteful. Finally, there are usually far too many versions of a particular network device's operating system to enable efficient storage, search and retrieval of the configuration knowledge used to generate a given device data configuration. Accordingly, a system and method are needed for more efficiently storing configuration knowledge and configuration instructions.
[0017] Network administrators have also found that the single-data-model implementation makes reverting to previous configurations difficult. When the configuration data and the configuration knowledge are bundled together as an atomic unit, network administrators have significant difficulty in reverting to a previous device configuration when both the configuration instructions and the configuration knowledge change. For example, when a network device is upgraded to run a new version of its operating system, both the configuration knowledge and the configuration instructions are changed. If the upgrade fails, rolling back the changes to a known state could be difficult. Accordingly, a system and method are needed to address the issues with reverting to previous configurations.
[0018] Present network technology suffers from yet another drawback in that it lacks a common information model that can be used to derive each of the application-specific configurations. One advantage of a common information model is that it can be used to model device capabilities independent of vendor implementations. This lack of an adequate common information model results in network applications having difficulty in retrieving and sharing network information from different network devices. Even more problematic is the fact that the lack of the common information model results in different network applications being unable to share different network data about the same network device for different applications. For example, each application might implement its own procedure for discovery of network devices because it cannot understand information generated by another network application. Accordingly, a system and method are needed to provide a common information model that can be used to derive each of the application-specific data models.
SUMMARY OF THE INVENTION
[0019] Exemplary embodiments of the present invention that are shown in the drawings are summarized below. These and other embodiments are more fully described in the Detailed Description section. It is to be understood, however, that there is no intention to limit the invention to the forms described in this Summary of the Invention or in the Detailed Description. One skilled in the art can recognize that there are numerous modifications, equivalents and alternative constructions that fall within the spirit and scope of the invention as expressed in the claims.
[0020] In one embodiment of the present invention, the configuration of a network device is separated into two portions: configuration knowledge and configuration instructions. The configuration knowledge abstractly represents the capabilities of a network device or resource. For example, the configuration knowledge for a router might indicate the types of traffic conditioning, chip organization, and routing protocols that are available to that router. It is important to note that configuration knowledge is not necessarily limited to one particular type of knowledge. Knowledge, for example, can broadly be classified into physical and logical knowledge. Configuration knowledge can be comprised of individual configuration schemata, which define the individual portions that make up the complete configuration knowledge. The configuration knowledge for a particular network device also is referred to as a knowledge data model (KDM).
[0021] Because the KDM for a device is constructed from a set of individual schemata, when the capabilities of that network device are changed, the corresponding schemata can be changed without otherwise rebuilding the entire KDM. For example, if a new card is added to a router, then the schemata for that new card is added to the KDM of the router. The remaining portion of the KDM, however, may remain unchanged. Similarly, if a router is updated with a new operating system (OS) the relevant schemata in the KDM can be modified. Notably, the individual features of the device can be modeled in individual schemata so that the schemata and features can be changed independently.
[0022] The configuration instructions for a particular network device are derived from the KDM for that device. Moreover, each configuration instruction set can be associated with a particular version of the KDM. For example, if a router is updated with a new operating system (OS), a new version of the KDM that reflects the new OS is created. Subsequent sets of configuration instructions can be associated with the new version of the KDM. Thus, any set of configuration instructions can be identified as being associated with a certain network device configuration. In one exemplary embodiment of the KDM, a version of knowledge can be directly linked to the combination of {vendor, device type, device family, device model, OS version}. This set of parameters can specify a given KDM.
[0023] In one exemplary embodiment, the present invention can include an assembler connected to a storage device that contains groups of configuration schemata. These groups of schemata represent the resources involved in meeting certain customer requirements and requests. For example, the schemata could be grouped according to performance, reliability, security, etc. In essence, these groups of schemata can represent a mapping between business needs and network resources. This mapping, in one embodiment, enables business rules to drive network configuration.
[0024] Another embodiment of the present invention enables customers to use business logic to request network services. For example, when a customer requests some action regarding the network, the assembler can look up the customer's account and identify the network resources that are both required for the transaction and available to the customer. The customer, for example, might have access to routers A, B, and C, all of which are necessary for turning-up service between two points. Using the KDM for each of the routers, the assembler can determine what resources, e.g., routing protocols or cards, are required of the routers to provision the requested customer service. For each relevant resource, the assembler can gather the appropriate configuration schemata or generate modifications from the KDMs. For example, the assembler could gather the relevant configuration schemata for a particular model of network card included in router A.
[0025] The abstraction provided by the KDM can make it easier to compare device capabilities as compared to comparing configuration commands. For example, each device can have different commands, making the comparison exceedingly difficult. Further, each vendor's configuration commands are not at the same abstraction level and do not use the same terms. The assembler can then identify the parameters within the network card's schemata that are configurable, select the correct configuration for those parameters, and build the necessary configuration instructions based upon the business rules defined by the customer. These configuration instructions could then be pushed to the appropriate network devices.
[0026] In another embodiment, the assembler responds to a customer's service request by identifying the necessary resources to meet the request and by retrieving a group of schemata that indicates the individual schemata relevant to the request. For example, the assembler could access the Voice QoS grouping that identifies a set of schemata that impact QoS for voice transmissions. The assembler could then match the relevant schemata from the group to the necessary resources, e.g., router or card, and build the necessary configuration instructions. These configuration instructions could then be pushed to the appropriate network devices.
[0027] In another embodiment of the present invention, the assembler can generate separate KDM and configuration instruction set archives. In other words, the KDM for a network device (or network resource) can be stored separately from the actual configuration instructions. Each set of configuration instructions, however, may be associated with the KDM that was used to build it. Thus, multiple sets of configuration instructions could be associated with a single KDM. Additionally, a difficult task can be migrating configurations from one version to another version of the device OS. The KDM provides the facility to compare different versions of the same device OS and enable one to be migrated to another version.
[0028] In yet another embodiment of the present invention, network management applications are configured to retrieve data from the various KDMs. Because the KDMs are abstractions of the actual device configurations, the network management applications can interact with the KDMs in a standardized fashion without necessarily understanding the exact syntax required by each network device. For example, Cisco™ routers utilize a CLI (command line interface) with a proprietary syntax that can change with every new release of the OS. Network applications must be able to understand Cisco's proprietary syntax and must update their systems with every change in that syntax. One embodiment of the present invention alleviates some of this difficulty by abstracting the capabilities of network devices in a KDM rather than lumping the capabilities with the actual configuration instructions. In essence, the separation of the configuration knowledge and the configuration instructions allows for better sharing of data between network applications.
[0029] As previously stated, the above-described embodiments and implementations are for illustration purposes only. Numerous other embodiments, implementations, and details of the invention are easily recognized by those of skill in the art from the following descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Various objects and advantages and a more complete understanding of the present invention are apparent and more readily appreciated by reference to the following Detailed Description and to the appended claims when taken in conjunction with the accompanying Drawings wherein:
[0031] [0031]FIG. 1 is a block diagram of one embodiment of the present invention;
[0032] [0032]FIG. 2 illustrates versioned KDMs and configuration instructions;
[0033] [0033]FIG. 3 illustrates one organization of a KDM for a network device;
[0034] [0034]FIG. 4 is a block diagram of a network including network management applications and a centralized KDM storage device and configuration data storage device;
[0035] [0035]FIG. 5 is a flowchart of one method for implementing a roll-back using KDMs and versioned configuration instructions; and
[0036] [0036]FIG. 6 is a flowchart of one method for implementing a business policy in a network.
DETAILED DESCRIPTION
[0037] Referring now to the drawings, where like or similar elements are designated with identical reference numerals throughout the several views, and referring in particular to FIG. 1, it is a block diagram 100 of one embodiment of the present invention. In this embodiment, an assembler 105 is connected to a configuration schemata storage device 110 , device configuration storage devices 115 —including KDMs 120 and configuration instruction sets 125 —a configuration policy device 130 , and a client 135 . Each of the network devices is associated with a KDM 120 and one or more configuration instruction sets 125 . For example, router 140 A, which is connected to network 140 , is associated with KDM A 120 A and configuration instruction set A 125 A.
[0038] The device configuration for each network device is separated into two portions: configuration knowledge (referred to as the KDM) and configuration instruction sets. The KDM abstractly represents the capabilities of a network device or resource. For example, the KDM for a router might indicate the available types of traffic conditioning, chip organization, and routing protocols. The configuration instruction sets represent the instructions used to configure a network device. A given device may have multiple instruction sets associated with it. Also, a given instruction set is likely to use only a small portion of the KDM, because typically individual devices only use a small set of possible features.
[0039] KDMs are comprised of a number of individual configuration schemata that describe functions and capabilities of network resources. Individual schemata can even be grouped to address particular network functions such as performance, QoS for data, QoS for voice, etc. Typical configuration schemata can describe:
[0040] How to treat various types of traffic, such as
[0041] Whether to deny, forward, or queue traffic.
[0042] How to condition traffic. (e.g., rate limit a flow or drop a packet).
[0043] Routed and routing protocol configuration.
[0044] Define the physical configuration and composition of a device.
[0045] General communication definition—unicast, broadcast, multicast, any cast.
[0046] Security configuration, including
[0047] Securing communications via, for example, IPSEC.
[0048] Determining who can log into the device to look at or change its configuration.
[0049] Service configuration, such as how virtual private networks are formed and maintained.
[0050] The combination of schemata to represent a network device or resource is referred to as the KDM. The KDMs for the various network devices can be stored together in a central storage device or distributed across multiple storage devices. Similarly, the configuration instruction sets for the various network devices can be stored together in a central storage device or distributed across multiple storage device. Additionally, the configuration instruction sets can also be stored at the individual network devices.
[0051] The KDM can be stored in a variety of formats, including XML. In one embodiment, the KDM is stored in a directory as a set of directory entries and LDAP or DAP is used as the access protocol. Such an implementation can use different types of relationships to associate different information with the device. Each type of relationship can be defined by the KDM.
[0052] Generally, a directory defines an object class as a set of entries that share the same characteristics. For example, an object class could be a router or a Cisco router. A typical directory has three types of object classes: abstract, structural, and auxiliary. Abstract classes are used as the highest level of abstraction of a class hierarchy to represent specific types of information. For example, physical characteristics and logical characteristics of a network device represent two distinct types of information that could be used as abstract classes of a KDM. Thus, a directory might define a root and two abstract classes: physical characteristics and logical characteristics. By making a class abstract, it generally cannot be instantiated.
[0053] Structural object classes, however, are instantiable and are used to define the contents of the DIT. An example of a structural class could include a particular device's configuration. Auxiliary object classes can be used to add to or remove from the list of attributes permitted in a particular structural object class or classes. The idea is for an auxiliary class to collect information that can augment other classes. One embodiment of the present invention can use auxiliary object classes to contain common information and attach that information to structural classes that represent differently types of resources.
[0054] The configuration instruction sets can also be stored in a variety of formats. In one embodiment, the configuration instructions sets are stored in a proprietary format that corresponds to the network device that uses the configuration instructions. This in turn can be stored as a single entry called a Binary Large Object (“Blob”) in the directory. In other embodiments, the configuration instructions could be stored in an intermediate format, e.g., XML, that is subsequently translated into a proprietary format. In this case, it may be more convenient to store the individual XML objects as separate directory entries. In other cases, the entire XML could be stored as a single entry. The choice can be determined by the application.
[0055] Still referring to FIG. 1, the assembler 105 is enabled to receive a service request from a client 135 . For example, the user might request that a connection between the New York office and the new San Francisco office be established and that the new link be optimized for Voice data. As another example, a program may request that a particular customer service be changed. In response, the assembler 105 could identify the resources needed to establish the link. For example, the assembler 105 could search an inventory of available network devices and identify those devices that could be used to establish the link. The assembler 105 could then identify the relevant schemata for turning-up service and for voice optimization. In one embodiment of the present invention, the assembler 105 selects a grouping of schemata such as “QoS Voice” 110 C that identifies the schemata and possibly the settings associated with voice QoS. The assembler can then link the identified schemata with the identified resources. For example, if an identified resource includes a particular card within a router, the schemata that make up the KDM for that card (or router) can be matched with the schemata that are needed to turn-up service and optimize voice QoS.
[0056] Referring now to FIG. 2, it illustrates versioned KDMs 145 and configuration instruction sets 150 that correspond to a particular network device. In this embodiment, the KDM 145 includes versions 1 through 4, and the configuration instruction sets 150 include versions 1.1 through 4.3. Each version of the configuration instruction sets is associated with at least one KDM 145 . For example, configuration instruction sets V1.1 and V1.2 correspond to KDM V1. Similarly, configuration instruction set V2.1 corresponds to KDM V2. Thus, for any set of configuration instructions, the KDM 145 used to build that set of instructions can be determined.
[0057] Referring now to FIG. 3, it illustrates one organization of a KDM 145 . This abstraction represents a family of devices that all share common features and/or other characteristics. The device family layer is refined by the device abstraction layer, which represents a software abstraction of a specific device. The device family layer is then further refined into its physical and logical aspects, which are represented by the physical and logical abstraction layers. By defining the device according to its physical and logical capabilities, the KDM 145 can support applications that require access to only physical or logical information. For example, the KDM 145 can support a physical inventory application that has no need of logical information. Likewise, the KDM 145 can support a capacity planning application that has need for both physical and logical information.
[0058] The physical and logical layers can be refined according to the features of the family of devices being represented. For example, the logical abstraction can include: address management, services, security, protocols, and traffic conditioning. Similarly, the physical abstraction can include: cabling, processors, cards, and chassis. These refinements are not inclusive, but rather exemplary for one type of device. Other abstractions include: users, groups, organizations, resource roles, services, capabilities, constraints, products, policies, processes, applications, etc. Moreover, the KDM 145 can be applied to most network resources, including routers, router components, switches, switch components, fabrics, optical devices, and optical components.
[0059] Referring now to FIG. 4, it is a block diagram of a system 155 that includes network management applications connected to a centralized KDM storage device 160 and configuration data storage device 165 . In this embodiment, a plurality of network management devices 170 , including network management applications, are connected to a KDM storage device 160 and a configuration data storage device 165 through a network 175 . The KDM storage device 160 and the configuration data storage device 165 are also connected to network devices such as router 180 .
[0060] When a network management device 170 needs configuration data about a particular network device or group of network devices, the network management device 170 can access the network device directly and read the relevant information. This process, however, generally requires the network management device 170 to understand the particular syntax of the network device's configuration. In one embodiment of the present invention, however, the network management device 170 can access the KDM storage device 160 and retrieve the relevant KDMs or portions thereof. Because the KDMs are abstractions of the device-specific instructions, the network management devices 170 generally are not required to understand the device-specific syntax of a particular network device. For example, a physical inventory application could access the KDMs for the relevant network devices and determine the cards that are used by each device without regard to the syntax of the actual configuration instructions.
[0061] Referring now to FIG. 5, it is a flowchart of one method for implementing a roll-back (e.g., the replacing of a new set of configuration instructions with a previous set of configuration instructions) using KDMs and versioned configuration data. Roll-backs are often useful for network administrators after network attacks or after unsuccessful network device updates—although they are useful in several other cases. For example, new hardware is often added to existing routers in a network. This new hardware can introduce new capabilities to the router that are reflected in a new version of the router's KDM. Additionally, the configuration instruction set for the router is usually modified to engage the new hardware. Thus, in this type of system upgrade, both the KDM and the configuration instruction set for the router are modified.
[0062] Assuming that a system upgrade is unsuccessful for some reason, network administrators often wish to roll-back the configuration to a previous, known configuration. For example, if the added card was defective, the network administrator might want to remove the defective card and roll-back the configuration to a previous configuration that does not use instructions for that card. To roll-back the configuration, the assembler or some other device can identify the device and a version of the KDM that does not reflect the card's presence. Step 185 and Step 190 . The configuration instruction sets associated with that KDM can then be identified, and one of those configuration instruction sets can be selected. Step 195 . That configuration instruction set can then be pushed to the network device. Step 200 .
[0063] Referring now to FIG. 6, it is a flowchart of one method for implementing a business policy in a network. In this embodiment, a user transmits a service request to the assembler. Step 205 . The assembler identifies the network resources and business rules applicable to filling the service request by, for example, retrieving information about the user from the configuration policy database. Steps 210 and 215 . The assembler then identifies the individual knowledge schemata or groups of schemata applicable to the service request. Step 220 . The assembler can then use those identified schemata to derive the device configuration instructions and push those instructions to the network device. Steps 225 and 230 . In one embodiment, the device configuration is derived by binding the variable information of each relevant schemata to the business purpose of the customer. For example, a QoS business purpose could be bound to the various traffic conditioning settings.
[0064] Other embodiments of the present invention include comparing and/or contrasting the features of different devices. For example, a network administrator may need to identify devices with similar capabilities and/or configurations. If these devices have different instruction formats, a straightforward comparison of configuration instructions can be extremely difficult. By using the knowledge data model associated with each of the devices, however, the devices can be easily compared without reference to the device's actual configuration instructions and without knowledge about the device's instruction formats. This type of comparison using the knowledge data model allows administrators to automatically or semi-automatically upgrade device operating systems and/or exchange device types. Additionally, this comparison feature allows the features of different devices to be identified and mapped to a particular service provided to a customer.
[0065] In conclusion, the present invention provides, among other things, a system and method for managing and utilizing network device configurations. Those skilled in the art can readily recognize that numerous variations and substitutions may be made in the invention, its use and its configuration to achieve substantially the same results as achieved by the embodiments described herein. Accordingly, there is no intention to limit the invention to the disclosed exemplary forms. Many variations, modifications and alternative constructions fall within the scope and spirit of the disclosed invention as expressed in the claims. Moreover, the term “computer program product” as used in the claims refers to computerized instructions embodied in any form and contained on any medium, including, but not limited to, RAM, magnetic storage, optical storage, carrier wave, etc. Additionally, the term “computer program product” encompasses a computer system operable according to the computer program product or that accesses the computer program product.
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A system and method for managing and performing network configurations is described. In one embodiment, an assembler can look up the customer's account and identify the network devices that are both required for a requested transaction. Using the knowledge data models (KDM) for the identified network devices, the assembler can determine which resources are available. For each relevant resource, the assembler can gather the appropriate configuration schemata from the KDMs. The assembler can then identify the parameters within the network resource's schemata that are configurable, select the correct configuration for those parameters, and build the necessary configuration instructions based upon the business rules defined by the customer. These configuration instructions could then be pushed to the appropriate network devices.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates, in general, to a method, system, and computer-program product for improved data processing in a computer system and, in particular, to a method, system, and computer-program product for providing an improved booting process for a data processing system.
2. Description of Related Art
In the early 1980s, as the first PC's were sold, people in the Information Systems (IS) industry thought that PC's might replace mainframe computers and cut operating costs drastically. Over the years, as personal computers gained more functionality and better user interfaces, end-users improved their productivity and ability to generate data. While enterprise data and legacy applications were still placed on the more reliable mainframe platforms, there was more and more need for distributed access to application and data resources.
The IS industry succeeded in connecting the two worlds of PC's and mainframes by implementing a client/server model with distributed databases. With the evolution of multi-platform applications over a variety of networking infrastructures, it appeared that PC's might replace mainframe computers. However, as people in the IS industry realized the immense overall costs of this approach, the client/server model evolved in many directions.
The choice of a wider variety of computer platforms improves the enterprise's ability to make appropriate investments in the evolving computing marketplace. The following is a description of various computer platforms and some of their characteristics.
Non-Programmable Terminals (NPT's) are often found in large enterprises connected to host-based applications systems. With the NPT, the user interface is managed and controlled by the central processing system. Historically, these terminals were the first to bring end-user access to information in the enterprise's central databases.
Network Computers (NC's), based on RISC processors, offer greater versatility than NPT's because they have a built-in capability to run emulation software and to provide access to Java™ and Windows™-based applications, such as browsers. NC's are typically implemented with only a general purpose processor, a system memory, and a communications port. Although other types of peripheral devices may be included, local drives, such as hard disk and floppy drives, are characteristically absent from such data processing systems. While the primary reason for not providing a local drive within such data processing systems is cost-saving, other reasons may include low-power requirement and compactness. Therefore, NC's typically rely upon network access to provide dynamic, non-volatile data storage capability. Managed PC's provide an Intel-based (or compatible) hardware platform that offers one the ability to run network computing operating systems. NC's and managed PC's are very similar. The major difference is that NC's generally have sealed cases and are not up-gradeable, while managed PC's have locked covers and can be upgraded.
Traditional PC's, such as desktop and laptop PC's, are designed to offer highly sophisticated end-user environments. People who travel a lot, or who work at various locations, may use laptop PC's that require local, nonvolatile storage devices and a fully functional set of applications wherever they are, whether or not there is network connection available. The installation of workgroup computing software and complete application suites requires a powerful machine with significant local networking capabilities.
Each of the various network computing platforms has advantages and disadvantages. NPT's have the advantage of presenting a standard platform to each user. However, as users become more technically sophisticated through everyday use of various computing devices, users demand more options in their access to data and to computing resources, which may not be available through the use of NPT's. Managed PC's may have the ability to be tailored for sophisticated users, but as their name implies, managed PC's are purposely restricted in the number and variety of the software applications and hardware configurations which are presented to the user.
Traditional PC's on a network have the advantage of providing extensive flexibility. In order to accommodate their need for computing resources, users may add peripherals and software applications directly to a PC, while a network administrator may provide other resources on the network for many users in a common fashion. The disadvantages include the immense burden placed on a network or system administrator in ensuring that the various PC's retain some semblance of a standard configuration. Certain operating systems, such as Microsoft Windows NT, provide various levels of system administration capabilities for accomplishing such tasks. However, enormous costs and amounts of time may be spent in accommodating user preferences while ensuring corporate directives for the use of standard configurations.
One of the main advantages of network computing is the any-to-any type of connectivity between applications without having to worry about the hardware or software platforms in use. Network computing can be described as the use of different open technologies providing connectivity, ease-of-use, application functionality, information access, scalability, and systems management across widely dispersed types of networks. By making use of open standard technologies, network computing provides many advantages of the client/server paradigm while avoiding its numerous disadvantages. This goal could be achieved by the implementation of standards on all the platforms involved, such as TCP/IP, for the networking protocol, and 100% pure Java™ applications, in the hope that it will lead to truly portable applications, and solutions where in the network computing environment, all devices are able to easily communicate with one another. Another advantage of network computing with NC's is the ability to provide functions for accessing data and applications while reducing the overall costs of operating an enterprise-wide environment. One may choose from a wider scope of configurations for the NC's to fit corporate requirements and reduce the overall costs. However, if the network computing environment is not managed properly, the administrative time and costs may be greater than those incurred in a traditional PC network. One disadvantage is that NC's, relative to other technologies, are still in a development and exploratory stage, although the IS industry believes that a networking platform with NC's may provide user-desired preferences while accomplishing corporate goals.
A common problem in many computing platforms is the necessity to maintain system administrative knowledge of enterprise-wide computer configurations while allowing some type of flexibility in the computer configurations. When one discusses the configuration of a computer, though, one necessarily must address multiple operating systems as different operating systems continue to be developed and deployed. A portion of any solution to the configuration-maintenance problem must also address the operating system configuration within the enterprise.
Looking towards a transition to network computing, the new network computing devices will not entirely replace the PC. Because different users have varying application needs, different technologies have to be employed to serve those needs, and those different technologies will be accompanied by different operating systems. Hence, there is a need for enterprise-wide support of multiple operating systems for these different computing platforms.
One solution to supporting multiple operating systems has been to develop the ability to boot a local client or NC through a remote server. In the normal operation of a stand-alone computer system, a user issues a boot command to the computer. The computer responds to the boot command by attempting to retrieve the operating system image files. Configuration data files are also needed to configure the specific machine with the hardware parameters necessary for the specific hardware configuration. These files also contain information needed to initialize the video, printers, and peripherals associated with that particular machine. For example, the files would include CONFIG.SYS in the MS-DOS operating system, available from Microsoft Corporation.
By booting through a remote server, the operating system image files may be maintained commonly on the server in an effort to control computer configurations. The network computing approach frequently provides three tiers of computing platforms, as described in FIGS. 1-3. This three-tier environment consists of: a client workstation, which handles the user interface and a minimal set of application functions; a server, which provides the major application functions; and a central corporate processing network, which provides access to legacy data and legacy applications. In a system where the computer has no nonvolatile memory means, the computer can not retrieve the boot information from within the computer itself. In that case, the client, e.g., computer system 108 , 110 , or 112 in FIG. 1 or data processing system 300 in FIG. 3, sends the boot request via the network bus 102 to a server 104 , which may be acting as a boot server.
As an example of an environment, which employs remote booting, the WorkSpace On-Demand environment, available from International Business Machines, provides a protocol for remote booting called Remote Initial Program Load (RIPL). The WorkSpace On-Demand client supports native execution of MS-DOS and Windows 3.x, all of which are available from Microsoft Corporation, and OS/2, which is available from International Business Machines.
RIPL is the process of loading an operating system onto a workstation from a location that is remote to the workstation. The RIPL protocol was co-developed by 3Com, Microsoft and IBM. It is used today with IBM OS/2 Warp Server, DEC Pathworks, and Windows NT. Two other commonly used Remote IPL protocols are a Novell NCP (NetWare Core Protocol), and BOOT-P, an IEEE standard, used with UNIX and TCP/IP networks.
RIPL is achieved using a combination of hardware and software. The requesting device, called the requester or workstation, starts up by asking the loading device to send it a bootstrap program. The loading device is another computer that has a hard disk and is called the RIPL server or file server. The RIPL server uses a loader program to send the bootstrap program to the workstation. Once the workstation receives the bootstrap program, it is then equipped to request an operating system, which in turn can request and use application programs. The software implementations differ between vendors, but theoretically, they all perform similar functions and go through a similar process.
In the WorkSpace On-Demand environment, with reference to FIG. 3, the client workstation requires a special ROM installed on its LAN adapter 310 . This ROM is also known as a Boot ROM or RIPL Module, which contains the initial code to begin the booting process. After the RIPL ROM on the adapter card receives the boot block from the boot server, the boot block gets control and then emulates a floppy drive. It takes over the floppy drive interrupt (Int 13 h ). As far as the workstation is concerned, it then has an “A:” drive with a write-protected bootable disk in it.
When the workstation starts up and issues a read request, the boot block intercepts the request and converts it into a network read request. Instead of reading data from the floppy, the data comes from the modified boot image file. For the RIPL function to be operational on a network, the network must have a RIPL server and one or more workstations with the necessary boot block module on its adapters.
Since the workstation thinks that it has a floppy drive, it requires all of the low-level data normally contained on a floppy disk. This includes the system sectors, FAT table, and directory tables. The Boot ROM obtains this information from a modified boot image file created on the server. The diskette image consists of a CONFIG.SYS file and the necessary device drivers that are required for the desired configuration. The modified boot image file is an exact image of the floppy that the workstation believes is in drive “A:”.
The client operating system image and all applications reside on servers. The client does not have local nonvolatile storage, i.e., storage that persists from one logon session to another, and end-user data is stored elsewhere on the network, usually on the server. When the end-user logs off or turns off the WorkSpace On-Demand client, the operating system, programs, and end-user data are no longer available to the end-user and are reloaded from the server when the end-user logs on again.
After the end-user logs on, the end-user desktop may then display the program objects for each application for which the end-user has access. When the end-user selects an application to run, the application launcher starts the application. The application launcher is a utility that attaches the appropriate network devices, sets up the environment, requests the application from the server, and starts the application on the client machine. When an application is started, the application environment is established, e.g., PATH, DPATH, and LIBPATH values. File access requests are routed based on the in-memory merge of the machine FIT (File Index Table) and user FIT tables. Upon application exit, the application launcher releases network devices used solely by the application.
There are several problems associated with Remote IPL'ing an operating system. First, the Remote IPL is dependent upon the particular operating system's file system architecture. The manner in which the operating system image and configuration files must be retrieved may vary from operating system to operating system. Second, the Remote IPL process may use some critical memory which is never freed to the operating system. Third, the operating system may be left with the inability to load its own networking support due to the exclusive use of the networking hardware by the Remote IPL code, which may prevent the operation system from using TCP/IP.
Thus, there is a need for a generic method for remote booting of a client computer regardless of the type of operating system while avoiding the potential problems identified above.
SUMMARY OF THE INVENTION
In view of the foregoing, it is therefore an object of the present invention to provide an improved method, system, and computer-program product for data processing.
It is another object of the present invention to provide an improved method, system, and computer-program product for providing a remote boot capability regardless of the type of operating system, which is being booted.
In accordance with a preferred embodiment of the present invention, a data-processing system provides a method for making a “snapshot” of critical system data areas, right after Power-On Self-Test and before the Remote IPL begins, by saving a copy of these critical system data areas. The RIPL software then retrieves a complete operating system image over a network and places the complete image in extended memory. The RIPL software then replaces the saved critical system data to create a system state in which the memory in the system includes the same content as it had just after it was booted, which also frees up the system memory and network support used by the Remote IPL software. The process then passes control to the appropriate location in the operating system image saved in extended memory so that the computer may continue the booting process.
One of the advantages of the present invention is its ability to load nearly any target operating system as a RIPL client. The RIPL client need not be concerned with RIPL environment restrictions as system resources used during the Remote IPL process are freed when the loaded operating system is booted.
Another advantage is that through a snapshot of key system data areas during initialization and the use of a bootable image, the system can be reset using the snapshot data area rather than being left in a state partially tailored to the Remote IPL process since the virtual bootable image is loaded as a new operating system.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is a block diagram of a distributed data processing system, which may be utilized in conjunction with a client-server environment;
FIG. 2 is a block diagram of a server computer, which may be utilized in conjunction with a client-server environment;
FIG. 3 is a block diagram of a computer, which may be utilized as a stand-alone computer or as a client computer in conjunction with a client-server environment;
FIG. 4 is a flowchart of the Remote Initial Program Load (RIPL) process according to the preferred embodiment of the invention;
FIG. 5A is a memory map diagram of the contents of client memory immediately after the Power-On Self-Test for an exemplary Network Computer booting under DOS;
FIG. 5B is a memory map diagram of the contents of client memory immediately after saving critical system data areas and loading the operating system image for an exemplary Network Computer booting under DOS; and
FIG. 5C is a memory map diagram of the contents of client memory immediately after restoring critical system data areas and immediately before continuing the boot process for an exemplary Network Computer booting under DOS.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, FIG. 1 depicts a pictorial representation of a distributed data processing system in which the present invention may be implemented and is intended as an example, and not as an architectural limitation, for the processes of the present invention.
Distributed data processing system 100 is a network of computers which contains a network 102 , which is the medium used to provide communications links between various devices and computers connected together within distributed data processing system 100 . Network 102 may include permanent connections, such as wire or fiber optic cables, or temporary connections made through telephone connections.
In the depicted example, a server 104 is connected to network 102 along with storage unit 106 . In addition, clients 108 , 110 , and 112 also are connected to a network 102 . These clients 108 , 110 , and 112 may be, for example, personal computers or network computers. For purposes of this application, a network computer is any computer, coupled to a network, which receives a program or other application from another computer coupled to the network. In the depicted example, server 104 provides data, such as boot files, operating system images, and applications to clients 108 - 112 . Clients 108 , 110 , and 112 are clients to server 104 . Server 104 may also act as a boot server because it stores the files and parameters needed for booting each of the unique client computers systems 108 - 112 .
Distributed data processing system 100 may include additional servers, clients, and other devices not shown. In the depicted example, distributed data processing system 100 is the Internet with network 102 representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational, and other computer systems, that route data and messages. Of course, distributed data processing system 100 also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN).
Referring to FIG. 2, a block diagram depicts a data processing system, which may be implemented as a server, such as server 104 in FIG. 1 in accordance with the present invention. Data processing system 200 may be a symmetric multiprocessor (SMP) system including a plurality of processors 202 and 204 connected to system bus 206 . Alternatively, a single processor system may be employed. Also connected to system bus 206 is memory controller/cache 208 , which provides an interface to local memory 209 . I/O bus bridge 210 is connected to system bus 206 and provides an interface to I/O bus 212 . Memory controller/cache 208 and I/O bus bridge 210 may be integrated as depicted.
Peripheral component interconnect (PCI) bus bridge 214 connected to I/O bus 212 provides an interface to PCI local bus 216 . A number of modems 218 - 220 may be connected to PCI bus 216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to network computers 108 - 112 in FIG. 1 may be provided through modem 218 and network adapter 220 connected to PCI local bus 216 through add-in boards.
Additional PCI bus bridges 222 and 224 provide interfaces for additional PCI buses 226 and 228 , from which additional modems or network adapters may be supported. In this manner, server 200 allows connections to multiple network computers. A memory-mapped graphics adapter 230 and hard disk 232 may also be connected to I/O bus 212 as depicted, either directly or indirectly. Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other peripheral devices, such as optical disk drive and the like also may be used in addition or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention.
The data processing system depicted in FIG. 2 may be, for example, an IBM RISC/System 6000 system, a product of International Business Machines Corporation in Armonk, New York, running the Advanced Interactive Executive (AIX) operating system.
With reference now to FIG. 3, a block diagram illustrates a data processing system in which the present invention may be implemented. Data processing system 300 is an example of either a stand-alone computer, if not connected to distributed data processing system 100 , or a client computer, if connected to distributed data processing system 100 . Data processing system 300 employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Micro Channel and ISA may be used. Processor 302 and main memory 304 are connected to PCI local bus 306 through PCI bridge 308 . PCI bridge 308 also may include an integrated memory controller and cache memory for processor 302 . Additional connections to PCI local bus 306 may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter 310 , SCSI host bus adapter 312 , and expansion bus interface 314 are connected to PCI local bus 306 by direct component connection. In contrast, audio adapter 316 , graphics adapter 318 , and audio/video adapter (A/V) 319 are connected to PCI local bus 306 by add-in boards inserted into expansion slots. Expansion bus interface 314 provides a connection for a keyboard and mouse adapter 320 , modem 322 , and additional memory 324 . SCSI host bus adapter 312 provides a connection for hard disk drive 326 , tape drive 328 , and CD-ROM 330 in the depicted example. Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors.
An operating system runs on processor 302 and is used to coordinate and provide control of various components within data processing system 300 in FIG. 3 . The operating system may be a commercially available operating system such as OS/2, which is available from International Business Machines Corporation. “OS/2” is a trademark of International Business Machines Corporation. An object oriented programming system, such as Java, may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs may be located on storage devices, such as hard disk drive 326 , and they may be loaded into main memory 304 for execution by processor 302 .
Those of ordinary skill in the art will appreciate that the hardware in FIG. 3 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 3 . Also, the processes of the present invention may be applied to a multiprocessor data processing system.
For example, data processing system 300 , if optionally configured as a network computer, may not include SCSI host bus adapter 312 , hard disk drive 326 , tape drive 328 , and CD-ROM 330 , as noted by the box with the dotted line in FIG. 3 denoting optional inclusion. In that case, the computer, to be properly called a client computer, must include some type of network communication interface, such as LAN adapter 310 , modem 322 , or the like. As another example, data processing system 300 may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system 300 comprises some type of network communication interface. As a further example, data processing system 300 may be a Personal Digital Assistant (PDA) device which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data.
The depicted example in FIG. 3 and above-described examples are not meant to imply architectural limitations with respect to the present invention.
With reference now to FIG. 4, a flowchart depicts the Remote Initial Program Load (RIPL) process according to the preferred embodiment of the invention. The process begins (step 400 ) when a server 200 determines that it should wake up a client computer, such as client 110 (step 410 ). Server 200 sends a wake-up command to client (step 420 ).
The wake-up may be performed by sending a command to the token-ring card of client 110 to force its power-up. As noted previously, in the WorkSpace On-Demand environment, client 110 contains a ROM, also known as a Boot ROM or RIPL Module, which contains the initial code to begin the booting process. These methods for waking-up client 110 are exemplary only as other methods could be used to initiate the waking-up process of client 110 prior to its actual bootup processing.
Client 110 then usually performs a Power-On Self-Test (POST) (step 430 ), which may include a processor checkout, memory read/write tests, and other well-known component tests. After the POST, client 110 saves critical system data areas by taking a “snapshot” of those areas (step 440 ), i.e., client 110 creates an exact byte-by-byte copy of the contents of those areas and saves this snapshot to a portion of memory which will not be disturbed or overwritten by subsequent processing. Client 110 then retrieves a complete operating system image file from server 200 (step 450 ). The operating system image file contains all necessary code and data for a computer to boot itself. Client 110 then places the operating system image file in memory (step 460 ). The location in memory should be such that the contents of the memory are not disturbed or overwritten until modified as part of the computer bootup sequence.
Client 110 then severs its network connection to server 200 (step 470 ) in order to ensure that the network hardware may be controlled and commanded as part of the subsequent bootup process since client 110 may load its own network protocol after the Remote IPL process is complete. If the boot image was previously modified to include the loading of a network device driver or otherwise providing for establishment of a network connection, then client 110 may establish a predetermined network protocol according to the predetermined preference stored in the operating system image. In this manner, the network connection between client 110 and server 200 may be severed but then reestablished.
Client 110 then restores critical system data areas (step 480 ). The data may be restored in a variety of manners: making an exact copy of the previously stored data and placing the copied data back in its appropriate location; memory block transfer; or other equivalent manners. After the restoration of the data, various memory sections may need to be reinitialized, etc., in order to “clean up” the memory after the RIPL process in order to prepare for subsequent bootup processing.
Client 110 then continues booting from the operating system image in memory (step 490 ). The process continues by passing control to the appropriate location or instruction in the operating system image which, in non-RIPL environments, might be called to begin the bootup process. Control may be passed by various well-known methods, such as a jump-and-execute assembly instruction, etc. The RIPL bootup process then ends (step 499 ).
FIGS. 5A-5C provide an example of the Remote IPL process, as discussed above with respect to FIG. 4, for a client which is booting up under DOS. FIGS. 5A-5C contain common numbers which refer to common elements in the figures.
With reference now to FIG. 5A, a memory map diagram depicts the contents of client memory immediately after the Power-On Self-Test for an exemplary NC or client 110 booting under DOS. Memory 500 contains empty memory areas 510 , 520 , 540 , 550 , and 560 . Memory area 570 contains BIOS Data Area (BDA) in memory addresses 0:400→0:500, which contains data values needed by the BIOS, or Basic I/O System. The BIOS is a set of essential instructions necessary for booting a PC and is stored in a ROM within the PC. The BDA provides a writable memory area into which the BIOS may save data. Memory area 530 contains Extended BIOS Data Area (EBDA) in memory addresses 0:9FC00→0:9FFFF, which provides the BIOS an extended memory area for saving data. Memory area 580 contains the Interrupt Vector Table (IVT) in memory addresses 0:0→0:400, which is a table of memory addresses, or pointers to the locations in memory, where instructions for an interrupt handler may be found.
With reference now to FIG. 5B, a memory map diagram depicts the contents of client memory immediately after saving critical system data areas and loading the operating system image for an exemplary NC or client 110 booting under DOS. Memory 500 contains empty memory areas 520 and 560 .
Memory area 570 contains the BDA. Memory area 530 contains the EBDA. Memory area 580 contains the IVT.
Memory areas 550 , 541 , 542 , 543 , and 510 have been modified in the period between the completion of the POST in step 430 and the current execution point after step 460 . Memory area 550 contains network drivers, which the initial RIPL processing has loaded into memory in order to communicate with server 200 . Memory area 510 contains an operating system image file which client 110 has retrieved from server 200 in step 450 through the use of the network drivers in memory area 550 and subsequently placed into memory area 510 in step 460 . Memory areas 541 , 542 , and 543 contain saved copies of critical system data areas-the EBDA, the BDA, and the IVT-created as part of the “snapshot” process in step 440 .
It should be noted that, at the current execution point after step 460 : memory area 541 is not identical to memory area 530 ; memory area 542 is not identical to memory area 570 ; and memory area 543 is not identical to memory area 580 . Memory areas 530 , 570 , and 580 may have changed during the execution of the RIPL processing. It is for this reason that these memory areas have been saved previously. By saving these memory areas, the RIPL processing may proceed without regard to its execution environment.
With reference now to FIG. 5C, a memory map diagram depicts the contents of client memory immediately after restoring critical system data areas and immediately before continuing the boot process for an exemplary NC or client 110 booting under DOS. Memory 500 contains empty memory areas 520 and 560 .
Memory area 530 contains the restored EBDA. Memory area 570 contains the restored BDA. Memory area 580 contains the restored IVT. The restored contents of these areas are the previously saved critical system data areas which were stored in memory areas 541 , 542 , and 543 , respectively. Memory area 510 contains the operating system image file which client 110 has retrieved from server 200 and is about to execute. Memory area 544 contains a floppy drive Int 13 h interrupt redirector which is registered as a last step in this example of boot up execution, before relinquishing control to the operating system image to perform subsequent boot up processing (step 490 ). In FIG. 5B, it is shown as being loaded in memory area 544 , which is where its instructions are located. In this particular example, it has been loaded into memory area 544 just under the EBDA in memory area 530 . The appropriate pointer would also have been registered into the IVT in memory area 580 .
As noted previously, under other conditions, a client starts up under DOS by attempting to read operating system image files from the floppy drive. In this example, the process continues in step 490 by passing control to the appropriate location or instruction in the operating system image which, in non-RIPL environments, might be called to begin the bootup process. When a client starts up and issues a read request, the floppy drive interceptor that has been registered in memory intercepts the request and converts it into a memory read request. Instead of reading data from the floppy, the data comes from the operating system image file loaded into memory. Since the client thinks that it has a floppy drive, the operating system image requires all of the low-level data normally contained on a floppy disk. This includes the system sectors, FAT table, and directory tables. The image also consists of a CONFIG.SYS file and the necessary device drivers that are required for the desired configuration. In other words, the operating system image file should be an exact image of the floppy that the client believes is in drive “A:”.
One of the advantages of the present invention is its ability to load nearly any target operating system as a RIPL client. The RIPL client need not be concerned with RIPL environment restrictions as system resources used during the Remote IPL process are freed when the loaded operating system is booted. In particular, the client may load its own network protocol after the Remote IPL process is complete.
Another advantage is that by taking a snapshot of key system data areas during initialization and the use of a bootable image, the system can be reset using the snapshot data area rather than being left in a state partially tailored to the Remote IPL process, and a virtual bootable image can be loaded as a new operating system.
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 a 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 a floppy disc, a hard disk drive, a RAM, and CD-ROMs, and transmission-type media, such as digital and analog communications links.
The description of the present invention has been presented for purposes of illustration and description, but is not limited 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.
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A data-processing system provides a method for making a “snapshot” of critical system data areas, right after Power-On Self-Test and before the Remote Initial Program Load (RIPL) begins, by saving a copy of these critical system data areas. The RIPL software then retrieves a complete operating system image over a network and places the complete image in memory. The RIPL software then replaces the saved critical system data to create a system state in which the memory in the system includes the same content as it had just after it was booted, which also frees up the system memory and network support used by the RIPL software. The process then passes control to the appropriate location in the operating system image saved in memory so that the computer may continue the booting process.
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CROSS-REFERENCE TO RELATED APPLICATION
The application is a Continuation-in-part of application Ser. No. 08/482,442, filed Jun. 7, 1995, and now abandoned the disclosure of which are herein incorporated by reference, which application is a Divisional of Ser. No. 08/142,668, filed Oct. 26, 1993, and now abandoned.
BACKGROUND OF THE INVENTION
In U.S. Pat. No. 3,882,090 there is disclosed hot melt seizing and adhesive compounds which employ water soluble polyamides made from one or more of the diacids selected from the group consisting of adipic, pimelitic and suberic acids and an aliphatic diamine having the formula:
H.sub.2 N--C.sub.y H.sub.2y --(OR).sub.n --O--C.sub.y H.sub.2y --NH.sub.2
where R is ethylene, 1,2-propylene or 1,3-propylene and n is an integer of 1 to about 13. The hot melt adhesives are said to be useful in making paper bags or book binding as the water solubility of the hot melt provides a method by which scrap paper can be recovered by repulping and adding the pulp back in the paper-making process. Such repulping operations utilize shredded scrap, elevated temperatures, typically 90°-110° F., and result in a separately generated batch of regenerated fiber.
In the paper manufacturing industry it is well known to use dry additives, such as the whitening agent titanium dioxide, which are shipped in large paper bags which must be individually opened and dumped into the pulp mixture. Typically such additives are added to an ambient temperature mixture, i.e. 60°-80° F. Recently, some such dry additives have been packaged in "beater bags" which are substantially closed across the top, using conventional water soluble bag manufacturing adhesives, except for a fold-in spout through which the bag is filled. The entire bag is then thrown into the pulp mixture for a batch of paper. The bag disintegrates, becoming incorporated into the pulp mixture along with its contents. Such beater bags have the disadvantage, however that filling through the spout is difficult and that after filling and folding in of the spout, the bag remains unsealed and therefore allows for leakage of the contents during shipping and handling.
It is known to utilize hot melt adhesives to seal bags of dry bulk chemicals but the adhesives previously used for this purpose have been incompatible with the pulp mixture and will cause discoloration or spotting of the manufactured paper.
There therefore exists a need for an improved beater bag which can be employed in paper making operations which can be sealed after filling and which and will cause discoloration or spotting of the manufactured paper.
SUMMARY OF THE INVENTION
Applicants have discovered that polyamides made from a polyethylene glycol diamine, or a bis-propylamine terminated polyethylene glycol, can be successfully employed as hot melt sealing adhesives for beater bags which will not leak in shipping and handling, which can be added directly to paper batches at ambient temperature without prior repulping and which will not cause discoloration or spotting of the paper produced from the batch.
The invention is in one aspect an improved method of making paper in which dry chemical additives are incorporated into the pulp mixture by addition of an entire bag containing the additive directly to the mixture, the improvement being that the bag is sealed with an adhesive closure, the adhesive being a hot melt consisting essentially of a water dispersable polyamide prepared from a diacid component comprising in major portion an aliphatic diacid of 6 or fewer carbon atoms and a diamine component consisting of one or more compounds of the formula:
H.sub.2 N--C.sub.y H.sub.2y --(OC.sub.2 H.sub.4).sub.x --O--C.sub.y H.sub.2y --NH.sub.2
where y is 2 or 3 and x is 1-50.
Bags containing dry chemicals sealed with a hot melt adhesive strip as described comprise further aspects of the invention method.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a beater bag of the prior art.
FIG. 2 is a fragmentary view of an unfilled hot melt sealable beater bag in accordance with the invention.
FIG. 3 is a perspective view of a filled and sealed beater bag in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As used herein, the term water-dispersable is used to refer to adhesives which, in layers of conventional adhesive thickness, readily dissolve or disperse in ambient temperature water without treatment other than simple agitation.
Referring first to FIG. 1, there is shown a beater bag 10 of the prior art. Bag 10 is assembled with a water based adhesive such as a starch based adhesive. However, such adhesives are not suitable for gluing filled bags. Consequently, the prior art bag 10 is provided with a glued spout 12 through which the bag is filled. The spout is then folded in so as to close, but not seal, bag 10. Filling bag 10 through the spout 12 is relatively difficult, and during shipping and handling it can, and often does, leak. Leakage creates extra work in cleanup and, depending upon contents, can be hazardous to workers handling such spout bags.
A pinch bag 20, 20a of the invention is shown in FIGS. 2-3. A pinch bottom bag with an open end is assembled within a water-dispersable instant adhesive, for instance, a starch-based adhesive as in bag 10 or a hot melt adhesive as described hereinafter. Bag 20 is suitably a multi-ply bag with the ends 21, 22, 23 of each ply staggered as shown in FIG. 2. A layer of water-dispersable hot melt 25 is applied to the open end of bag 20 over the staggered ply ends. The open bag is easily filled, without requiring special handling to fit the spout 12 of the prior art bag onto a special filling apparatus.
The bag 20 of the invention may be closed after filling by use of conventional apparatus for closing and sealing bags containing hot melt closure strips to produce a filled closed bag 20a. An example of such an apparatus is the PCB-5600 pinch bag closer sold by Fishbein Company, Minneapolis Minn.
Filled, closed bag 20a, as shown in FIG. 3 has a fully sealed closure 30. Unlike other hot melt closed bags, however, the use of the water-dispersable hot melt adhesive allows the bag to be used as a beater bag in the known paper-making process for which the prior art bag 10 was designed. Because the hot melt is applied to each ply, the closure is very strong and will not leak, even when subjected to very rough handling. Thus, the use of a pinch bag closed with a water-dispersable hot melt adhesive comprises a significant advance in the art.
The preferred hot melts utilized in the invention are additionally able to withstand normal packaging and handling stresses even when the contents are at temperatures substantially above ambient temperature. In particular, titanium dioxide powders are commonly bagged as they are produced, or after only short times thereafter. It is typical that the powders will still be warm on filling. Pallets of the filled bags will retain heat for considerable time. The hot melt adhesives used in the invention are able to maintain adequate bond strength on such warm pallets so that the seal 30 is not jeopardized. This warm strength is a property previously unreported for the water dispersable hot melt adhesives employed in the invention.
While the use of polyamides of U.S. Pat. No. 3,882,090, based on one or more of the diacids selected from the group consisting of adipic, pimelitic and suberic acids and an aliphatic diamine having the formula:
H.sub.2 N--C.sub.y H.sub.2y --(OR).sub.n --O--C.sub.y H.sub.2y --NH.sub.2
where R is ethylene, 1,2-propylene or 1,3-propylene and n is an integer of 1 to about 13 is contemplated, the applicants have discovered further water dispersable polyamides which can be employed as hot melt adhesives.
The polyamides may be used alone or in combination with minor amounts of conventional hot melt additives, such as antioxidants, melt viscosity modifiers, waxes, and the like, provided that the additives do not themselves adversely affect the water dispersability of the adhesive formulation. Water-dispersable polyamides can be prepared by reacting adipic acid with polyethylene glycol diamines, like triethylene glycol diamine (Jeffamine® EDR-148) or tetraethylene glycol diamine (Jeffamineg® ER-192) or a combination of the two diamines. Use of lower carbon diacids with the two diamines also provide water-dispersable polyamides. Polyamides from diacids with higher carbon numbers (C 7 or greater) are insoluble in water, but a combination of these higher diacids with adipic acid can produce water-soluble or waterdispersable polyamides. Increasing the amount of higher carbon diacids in conjunction with adipic acid results in polyamides with decrease in solubility. However, this can be compensated by increasing the EO (ethylene oxide) content of a portion of the polyethylene glycol diamine component. Jeffamine® ED 600, ED 900, ED 2000, D-230, D-400 and D-2000 are examples of higher EO content polyoxyalkylene diamines which may be employed. Thus, in particular, Dimer Acid can be used in combination with adipic acid when triethylene glycol diamine or tetraethylene glycol diamine are employed in combination with the polyoxyalkylene diamines Jeffamine® ED 600 or D 400.
The polyamides employed in the invention may be prepared as described in Example 1 of U.S. Pat. No. 3,882,090. Modifications of the recipe given in that example may be made as described above. Typical recipes are given below for illustrative purposes only, it being understood that those skilled in the art can readily modify the recipes without departing from the invention hereof:
______________________________________ Parts By Weight______________________________________1) Adipic Acid 146.14 Triethylene Glycol Diamine 148.02) Adipic Acid 146.14 Tetraethylene Glycol Diamine 192.03) Adipic Acid 146.14 TTD.sup.1 Diamine 220.3______________________________________ .sup.1 4,7,10-trioxatridecane-1,13-diamine
Polyamide melt viscosity can be controlled by adding small amounts, typically less than 5%, preferably 0.5-2.5% based on total acid weight of monoacids such as stearic or benzoic acid. An example recipe is given below:
______________________________________4) Adipic Acid 145.4 Stearic Acid 2.7 TTD Diamine 220.3______________________________________
Recipes 5 and 6 below illustrate the use of acids of C 7 or higher carbon content.
______________________________________5) Adipic Acid 164.4 Triethylene Glycol Diamine 205.8 Azelaic Acid 71.3 Jeffamine ® D-400 61.86) Adipic Acid 146.1 Diner Acid 57.8 Jeffamine ® ED-600 60.0 Tetraethylene Glycol Diamine 198.4______________________________________
Similar results are also obtained when an equivalent amount of tetraethylene glycol diamine or TTD Diamine is employed in place of the triethylene glycol diamine of recipe 5 and when an equivalent amount is employed in place of the tetraethylene glycol diamine of recipe 6.
The water dispersable hot melts of the invention further preferably contain water insoluble waxes such as fatty amide waxes, fatty acid waxes, oxidized polyethylene waxes and oxidized Fischer-Tropsch waxes. The invention further contemplates the addition of other functionalized waxes which would be compatible in the adhesives of the invention. Compatibility refers to a smooth and substantially homogeneous mixture which does not phase separate even though the waxes may be considered "water insoluble", surprisingly they do not prevent the adhesives of the invention from being repulpable and soluble in water. In order to effectively utilize the polyamides in the above mentioned beater bag application, such waxes are desired.
The preferable range for non-reactive waxes is approximately 1-15% by weight. Most preferably the range is 3-10%. The preferable range for reactive waxes is approximately 1-10% by weight. Most preferably the range is 2-6%. Higher percentages of the wax as a reactive component can lead to side reactions, change in viscosities and/or phase separation, leading to poor machinability. Reactive waxes are preferable because their incorporation results in a single component product.
The following examples are water soluble polyamides which also contain a water insoluble wax. These examples have been determined to be better performing adhesives in the beater bag application than comparable water soluble polyamides that do not contain a wax. A wax will lower the viscosity of the adhesive increasing penetration of the adhesive into the substrates on which a bond is desired therefore creating a stronger bond with more fiber tear. The resultant adhesives also set faster which is an important attribute for running on plant equipment. A need for increased efficiency in manufacturing facilities results in ever increasing line speeds and therefore a need for faster setting adhesives.
______________________________________Example Formulations Using WaxFORMULATION #1 Parts by Weight______________________________________Adipic Acid 164.4Azelaic Acid 71.3Jeffamine ® EDR-148 205.8Jeffamine ® D-400 61.8Irganox 1098 8.5Kenamide W 40 Wax 36.0______________________________________
The Kenamide W 40 in the table above is a water insoluble wax and chemically is a bis-stearamide of ethylene diamine or N,N-ethylene bis-stearamide. It is available from Witco Chemical Corp. located in Memphis, Tenn. The remaining ingredients are reacted prior to the addition of the wax. The Kenamide W 40 Wax is then mixed into the reactive hot melt as an inert ingredient.
______________________________________FORMULATION #2 Parts by Weight______________________________________Adipic Acid 164.4Azelaic Acid 71.3Jeffamine ® EDR-148 205.8Jeffamine ® D-400 61.8Irganox 1098 7.5Wax S 20.4______________________________________
The Wax S in Formulation #2 is a water insoluble wax known as a technical montanic acid wax or a montanic fatty acid wax. Wax S is available from Hoechst Celanese located in Charlotte, NC. In the above Formulation #2, the remaining ingredients of the polyamide were first combined and were heated at 240°-250° C. for 2 hours. Substantially all of the water was then removed. The Wax S was then incorporated by adding it to the resultant polyamide at a temperature of between 240°-250° F. and allowed to react for 11/2-2 hours. In this example, the wax is a reactive component of the adhesive, and provides the adhesive with a fast rate of set. This adhesive is therefore a single component product and not a blend.
The following tests were conducted on the resulting formulations to measure effectiveness.
TEST METHODS
1. REPULPABILITY
A. TAPPI Useful Method 666 or UM666--Adhesive samples are agitated at high speeds in a Waring blender for 15 seconds using water at the desired temperature. The resulting mixture is filtered through a 60-mesh screen. If nothing is retained on the screen, the adhesive is completely repulpable.
B. Stone Container Pulping Method #2--Adhesive coated kraft paper is pulped to form handsheets. Using this method, 40.0 g of adhesive coated paper is cut into 1 in.×1 in. squares. The squares are then added to a Noram CA 371 model disintegrator containing 1600 ml of water. The water may be at room temperature or at elevated temperatures. The mixture is agitated for 25 minutes to form the pulp. Handsheets are then made by collecting either 100 ml or 200 ml of the pulp. The absence of any spotting on the resultant dried handsheet indicates that the adhesive was completely repulped.
2. MELT VISCOSITIES
The melt viscosities of the hot melt adhesives were determined on a Brookfield Thermosel Viscometer Model DV I using a number 27 spindle.
3. BONDING TESTS
Between 1 and 2 mls of adhesive were coated on the beater bags. The bags were then heat sealed using a Fishbein Model # PBC 5600 Pinch Bag Closer. The platen air temperature was set at about 530° C. (about 980° F.) while the actual temperature was about 450° C. (about 850° F.); line speed was 38.5 feet per minute; seal pressure was 15 psi; and air flow was 8.0 cubic feet per minute. Once the bags have been sealed using this method, then the amount of fiber tear from the bags is observed. Adhesives are rated using a comparative method. The more fiber tear, the better the adhesive, with 100% fiber tear being the best.
RESULTS
1. FORMULATION #1
Repulpability was tested using the TAPPI Useful Method 666 and the Stone Container Method #2. The resulting adhesive was found to be completely repulpable in both tests.
The resulting viscosity for this product was 5000 cPs to 6000 cPs. The acceptable viscosity range for the beater bag application is less than about 15,000 cPs.
Good to excellent fiber tear was observed.
2. FORMULATION #2
Repulpability was tested using the Stone Container Method #2. No spotting was observed with this product. The handsheets were made using both 200 ml and 100 ml of pulp. No heat was used. This indicates that the product was 100% repulped.
The resulting viscosity for this product was 8000 cPs to 12,000 cPs. The acceptable viscosity range for the beater bag application is less than about 15,000 cPs.
Good to excellent fiber tear was observed.
The use of the above mentioned waxes improve the adhesive nature of the polyamide dispersion without appreciably affecting the repulpability and solubility of the formulation. The surprising dispersability of the adhesive with the incorporation of the waxes also illustrated in the repulpability test by the fact that no wax is found in final repulped mixtures or handsheets.
The polyamide formulation of the present invention also displays surprising humidity resistance, which is increased with the incorporation of the waxes. Examples of such resistance in analogous polyamide adhesives may be found in the U.S. patent application, Ser. No. 08/634,281, which is incorporated herein by reference.
The above Examples and disclosure are intended to be illustrative and not exhaustive. These examples and description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims attached hereto.
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A method of making paper in which dry chemical additives are incorporated into the pulp mixture by addition of an entire bag containing the additive directly to the mixture, the improvement being that the bag is sealed with an adhesive closure, the adhesive being a hot melt consisting essentially of a water dispersable polyamide prepared from a diacid component comprising in major portion an aliphatic diacid of 6 or fewer carbon atoms and a diamine component consisting of one or more compounds of the formula:
H.sub.2 N--C.sub.y H.sub.2y --(OC.sub.2 H.sub.4).sub.x --O--C.sub.y
H 2y --NH 2
where y is 2 or 3 and x is 1-50 and a wax. Such bags will not leak in shipping and handling, and yet can be added directly to paper batches at ambient temperature in the manner of the unsealable bags employed in the prior art.
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RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional application No. 60/505,857 filed on Sep. 26, 2003 by Mark Taunton & Timothy Martin Dobson and entitled “System and Method for Bit Reversing and Scrambling Payload Bytes in an Asynchronous Transfer Mode Cell,” which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to Asynchronous Transfer Mode (ATM) systems and to the design of instructions for processors. More specifically, the present invention relates to a system, method and processor instruction for bit-reversing and scrambling ATM payload data.
BACKGROUND OF THE INVENTION
[0003] ATM (Asynchronous Transfer Mode) cell streams are a commonly used way to format and transport data in a digital telecommunication system, for example over an ADSL (Asymmetric Digital Subscriber Line) link. An ATM cell comprises a 5-byte cell header and 48 bytes of payload. The cell header contains address and control data, which is used in a network to direct the transfer of the ATM cell from its source to its destination. The payload contains the data to be communicated to the destination.
[0004] International standards for ADSL and other forms of DSL (such as ITU-T Recommendation G992.1 entitled “Asymmetrical digital subscriber line (ADSL) transceivers,” ITU-T Recommendation G992.2 entitled “Splitterless asymmetric digital subscriber line (ADSL) transceivers,” ITU-T Recommendation G992.3 entitled “Asymmetric digital subscriber line transceivers—2 (ADSL2),” and ITU-T Recommendation G992.4 entitled “Splitterless asymmetric digital subscriber line transceivers 2 (splitterless ADSL2)”) define a method of conveying ATM cell streams over the DSL link. The method requires, amongst other things, that as cells are processed in the transmitting modem, the payload data bytes in each transmitted cell are scrambled using a self-synchronizing scrambler with polynomial X 43 +1. An equivalent way of describing the scrambling process is that for the stream of successive bits making up the input to the scrambler, x(n) (n=0, 1, 2, . . . ), the output of the scrambler y(n) is defined recursively as:
y ( n )= x ( n )+ y ( n− 43)
where + means addition modulo 2 (which is equivalent to logical “exclusive-or”). In other words, for each input bit, the output bit is the exclusive-or of that input bit and the output bit from 43 bit-times earlier.
[0006] The scrambling process is continuous over all bits of all payload bytes of all transmitted cells in a given ATM cell stream; it does not stop at the end of one byte or cell and start independently at the beginning of the next. Rather, the previous output bits which are used in the scrambling of new input bits are derived in the same way for every bit processed, without regard to byte or cell boundaries.
[0007] According to ATM standards, only the payload bytes are scrambled in this way: the header bytes are not scrambled and play no part in the process. For purposes of the scrambling process, the payload bytes of one cell are considered consecutive with the payload bytes of the preceding cell, ignoring the header bytes at the start of the new cell.
[0008] This scrambling scheme is also employed in a number of other contexts where ATM streams are passed between processing units over intermediate links.
[0009] A further common requirement for transmission of ATM cell streams over a DSL link concerns the ordering of the data bits in each byte of the ATM cell data being sent and received over the DSL link. When cells are passed across the external data interface of a DSL modem, DSL standards require the bits in each byte of the cell to be reversed in order. This is because whereas external to the modem, the most significant bit of each byte is considered to come first and is processed first, internally in the modem, the least significant bit of each byte is processed first, but the actual order of processing of the bits must be preserved. This reversal applies to all bytes of each ATM cell.
[0010] In an ATM-based modem in a telecommunication system, ATM cells may pass through the device for transmission at a high rate (for example in a multi-line ADSL or VDSL modem in a central-office DSL access multiplexer). It is therefore necessary to scramble the payload data of ATM cells efficiently. In prior art hardware oriented DSL modems, the ATM cell streams flow through fixed-function hardware circuits that include the logic to scramble the payload data stream. However, such system designs are typically much less adaptable to varying application requirements. In such hardware implementations of the scrambling function the data flow is fixed in an arrangement dictated by the physical movement of data through the hardware, and cannot be adapted or modified to suit different modes of use. For example, in such systems, the ‘state’ (the history of earlier output bits) is held internally within the scrambling hardware, rather than being passed in as and when scrambling is required. This means that re-using a hardware implementation to scramble multiple distinct data streams at the same time is either impossible, or certainly more complex to implement, since some arrangement must be made to allow the individual states for the different streams to be swapped in and out.
[0011] Current prior art DSL modems often use software to perform at least some of the various functions in a modem. One disadvantage of scramblers in current DSL modems is the inefficiency of such scramblers as the line-density and data-rates required of modems increase. As line-density and data-rates increase, so does the pressure on prior art modems to perform efficiently the individual processing tasks, such as scrambling, which make up the overall modem function.
[0012] Another disadvantage with current prior art scramblers is the software complexity required to implement such scramblers. Using conventional bit-wise instructions such as bit-wise shift, bit-wise exclusive-or, etc. may take many tens or even hundreds of cycles to perform the ATM scrambling operation for a single ATM cell. One processor may need to handle several hundred thousand ATM cells per second. Thus, the scrambling process for each cell can represent a significant proportion of the total computational cost for current prior art DSL modems, especially in the case of a multi-line system where one processor handles the operations for multiple lines. With increasing workloads, it becomes necessary to improve the efficiency of scrambling ATM cell payload bytes over that of such prior art modems.
[0013] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
SUMMARY OF THE INVENTION
[0014] According to the present invention, these objects are achieved by a system and method as defined in the claims. The dependent claims define advantageous and preferred embodiments of the present invention.
[0015] The present invention provides a method and apparatus for efficiently bit-reversing and scrambling one or more bytes of ATM payload data according to DSL standards. In a preferred embodiment of the invention, this is achieved by providing an instruction for bit-reversing and scrambling one or more bytes of data according to the DSL standards in a modem processor. In this embodiment, the system and method of the present invention advantageously provide a processor with the ability to bit-reverse and scramble data with a single instruction thus allowing for more efficient and faster scrambling operations for subsequent modulation and transmission. The present invention also advantageously provides great flexibility in determining the arrangement and flow of data during the scrambling process through the use of registers and memory for storing the original data to be scrambled, the resulting scrambled data, and the state data.
[0016] These and other advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0017] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
[0018] FIG. 1 illustrates a block diagram of a communications system in accordance with the present invention.
[0019] FIG. 2 illustrates a block diagram of a processor in accordance with one embodiment of the present invention.
[0020] FIG. 3A illustrates an instruction format for a three-operand instruction supported by the processor in accordance with one embodiment of the present invention.
[0021] FIG. 3B illustrates an instruction format for bit-reversing and scrambling one or more bytes in accordance with one embodiment of the present invention.
[0022] FIG. 4 is a logic diagram of one embodiment of the bit-reverse/scrambling instruction.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known processes and steps have not been described in detail in order not to unnecessarily obscure the present invention.
[0024] The invention generally pertains to a new instruction for operating a processor which significantly reduces the number of cycles needed to perform the bit-order-reversal and scrambling of ATM cell payload data. The present invention directly implements both the bit-order-reversal and scrambling process for 8 bytes (64 bits) of payload data in a single operation. The instruction takes as input 64 bits of new (original) source data, and 43 bits of previous scrambling state, and produces as output 64 bits of bit-reversed and scrambled payload data. Because the scrambling process is recursive, the last 43 bits of the output value from one application of the instruction for some ATM payload data stream act as the “previous state” input to the next application of the instruction to the same stream. As used herein, the terms bit-reverse or bit-order reversal mean creating a new linear bit sequence by taking the bits of the original linear bit sequence in reverse order as is required under DSL standards for the transmission of ATM cells. The present invention can be used in an implementation of an ADSL Termination Unit—Central (Office) (ATU-C), in an ADSL Termination Unit—Remote end (ATU-R), in a VDSL Transceiver Unit—Optical network unit (VTU-O) or VDSL Transceiver unit—Remote site (VTU-R), or in other contexts that require payload data to be scrambled in the same way.
[0025] The new instruction takes as one input an 8-byte sequence of ATM cell payload bytes (assumed to have been transferred directly from a modem's external data interface) as a composite 64-bit value. Its second input is a 43-bit value holding the internal state of the scrambling process between consecutive sections of data being scrambled. As described above this 43-bit state is equal to the last 43 bits of the previous output of the scrambling process (i.e. the result of a previous execution of the instruction to process the previous 8 bytes of payload data).
[0026] Embodiments of the invention are discussed below with references to FIGS. 1 to 4 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments.
[0027] Referring now to FIG. 1 , there is shown a block diagram of a communications system 100 in accordance with one embodiment of the present invention. System 100 provides traditional voice telephone service (plain old telephone service—POTS) along with high speed Internet access between a customer premise 102 and a central office 104 via a subscriber line 106 . At the customer premise end 102 , various customer premise devices may be coupled to the subscriber line 106 , such as telephones 110 a , 110 b , a fax machine 112 , a DSL CPE (Customer Premise Equipment) modem 114 and the like. A personal computer 116 may be connected via DSL CPE modem 114 . At the central office end 104 , various central office equipment may be coupled to the subscriber line 106 , such as a DSL CO (Central Office) modem 120 and a POTS switch 122 . Modem 120 may be further coupled to a router or ISP 124 which allows access to the Internet 126 . POTS switch 122 may be further coupled to a PSTN 128 .
[0028] In accordance with one embodiment of the present invention, system 100 provides for data to be sent in each direction as a stream of ATM cells between the central office 104 and the customer premise 102 via subscriber line 106 . As data is sent from the central office 104 to the customer premise 102 , the DSL CO modem 120 at the central office 104 bit reverses and then scrambles the payload data of each ATM cell in accordance with the principles of the present invention before modulating and transmitting the data via subscriber line 106 . Similarly, when data is sent from the customer premise 102 to the central office 104 , the DSL CPE modem 114 at the customer premise 102 bit reverses and then scrambles the payload data of each cell in accordance with the principles of the present invention before modulating and transmitting the data via subscriber line 106 . In a preferred embodiment, DSL CO modem 120 incorporates a BCM6411 or BCM6510 device, produced by Broadcom Corporation of Irvine, Calif., to implement its various functions.
[0029] Referring now to FIG. 2 , there is shown a schematic block diagram of the core of a modem processor 200 in accordance with one embodiment of the present invention. In a preferred embodiment, processor 200 is the FirePath processor used in the BCM6411 and BCM6510 devices. The processor 200 is a 64 bit long instruction word (LIW) machine consisting of two execution units 206 a , 206 b . Each unit 206 a , 206 b is capable of 64 bit execution on multiple data units, (for example, four 16 bit data units at once), each controlled by half of the 64 bit instruction. The twin execution units, 206 a , 206 b , may include single instruction, multiple data (SIMD) units.
[0030] Processor 200 also includes an instruction cache 202 to hold instructions for rapid access, and an instruction decoder 204 for decoding the instruction received from the instruction cache 202 . Processor 200 further includes a set of MAC Registers 218 a , 218 b , that are used to improve the efficiency of multiply-and-accumulate (MAC) operations common in digital signal processing, sixty four (or more) general purpose registers 220 which are preferably 64 bits wide and shared by execution units 206 a , 206 b , and a dual ported data cache or RAM 222 that holds data needed in the processing performed by the processor. Execution units 206 a , 206 b further comprise multiplier accumulator units 208 a , 208 b , integer units 210 a , 210 b , bit reverse/scrambler units 212 a , 212 b , Galois Field units 214 a , 214 b , and load/store units 216 a , 216 b.
[0031] Multiplier accumulator units 208 a , 208 b perform the process of multiplication and addition of products (MAC) commonly used in many digital signal processing algorithms such as may be used in a DSL modem.
[0032] Integer units 210 a , 210 b , perform many common operations on integer values used in general computation and signal processing.
[0033] Galois Field units 214 a , 214 b perform special operations using Galois field arithmetic, such as may be executed in the implementation of the well-known Reed-Solomon error protection coding scheme.
[0034] Load/store units 216 a , 216 b perform accesses to the data cache or RAM, either to load data values from it into general purpose registers 220 or store values to it from general purpose registers 220 . They also provide access to data for transfer to and from peripheral interfaces outside the core of processor 200 , such as an external data interface for ATM cell data.
[0035] Bit reverse/scrambler units 212 a , 212 b directly implement the bit reverse and scrambling process for the processor 200 . These units may be instantiated separately within the processor 200 or may be integrated within another unit such as the integer unit 210 . In one embodiment, each bit reverse/scrambler unit 212 a , 212 b takes as input 64 bits of new (original) source data, and 43 bits of previous scrambling state, and produces as output 64 bits of bit-reversed and scrambled payload data. Because of the recursive definition of the scrambling process, the last 43 bits of the output value from one application of this instruction for some data stream act as the “previous scrambling state” input to the next application of the scrambling function to the same data stream.
[0036] Referring now to FIG. 3A , there is shown an example of an instruction format for a three-operand instruction supported by the processor 200 . In one embodiment, the instruction format includes 14 bits of opcode and control information, and three six-bit operand specifiers. As will be appreciated by one skilled in the art, exact details such as the size of the instruction in bits, and how the various parts of the instruction are laid out and ordered within the instruction format, are not themselves critical to the principles of the present invention: the parts could be in any order as might be convenient for the implementation of the instruction decoder 204 of the processor 200 (including the possibility that any part of the instruction such as the opcode and control information may not be in a single continuous sequence of bits such as is shown in FIG. 3 ) The operand specifiers are references to registers in the set of general purpose registers 220 of processor 200 . The first of the operands is a reference to a destination register for storing the results of the instruction. The second operand is a reference to a first source register for the instruction, and the third operand is a reference to a second source register for the instruction.
[0037] Referring now to FIG. 3B , there is shown an example of a possible instruction format for bit-reversing and scrambling one or more bytes of data (ATMSCR) supported by processor 200 in accordance to the present invention. Again it should be observed that exact details of how this instruction format is implemented—the size, order and layout of the various parts of the instruction, exact codes used to represent the ATMSCR opcode, etc.—are not critical to the principles of the present invention. The ATMSCR instruction uses the three-operand instruction format shown in FIG. 3A , and in one embodiment, is defined to take three six-bit operand specifiers. The first of the operands is a reference to a destination register for an output “out” where the results of the ATMSCR instruction are stored. The second operand is a reference to a source register for a state input “state” from which state data is read, and the third operand is a reference to a source register for the data input “in” from which the original source data is read. One skilled in the art will realize that the present invention is not limited to any specific register or location for those registers but that the instruction of the present invention may refer to an arbitrary register in the general purpose registers 220 .
[0038] Thus, by means of this generality of specification, the present invention advantageously achieves great flexibility in the use of the invention. For example, the present invention enables the original data, which is to be bit-order reversed and scrambled, to be obtained from any location chosen by the implementor (e.g. by first loading that data from the memory 222 , or from an external data interface connected via load/store units 216 a , 216 b , into any convenient register). Likewise, the resulting bit-reversed and scrambled data may be placed anywhere convenient for further processing such as in some general purpose register 220 for immediate further operations, or the resulting bit-reversed and scrambled data may be placed back in memory 222 for later use. Similarly, the arrangement of how the ‘state’ data is obtained is also completely unconstrained, but may be arranged according to preference as to how the unscrambled and scrambled data streams are handled. Thus, the flexibility of the present invention is in sharp contrast to conventional (hardware) implementations of the scrambling function, where the data flow is fixed in an arrangement dictated by the physical movement of data through the hardware, and cannot be adapted or modified to suit different modes of use. For example, typically in such hardware contexts the ‘state’ (the history of earlier output bits) is held internally within the scrambling hardware, rather than being passed in as and when scrambling is required. This means that re-using a hardware implementation to scramble multiple distinct data streams at the same time is either impossible, or certainly more complex to implement, since some arrangement must be made to allow the individual states for the different streams to be swapped in and out.
[0039] Including the bit-reversal process as part of the function carried out by the instruction in the present invention is advantageous in that the external data interface circuitry through which the ATM cells are received can simply pass all bytes through in the standard bit-order, rather than itself reverse the order. Thus, the external data interface as used with the present invention is not specialized to the handling of only ATM cell data and could be used to transfer other types of data (which are unlikely to require the bit-order reversal) without impediment. Moreover, the present invention allows for software to process certain parts of the ATM cells (particularly the cell headers which are distinct from the payload bytes) in the standard bit order (as used outside the DSL modem), e.g. to work with cell addressing information which is stored in each cell header. If the modem's external data interface reversed the bit-order for all bytes passing through, this would necessitate an extra step of re-reversing the bit-order for the cell header bytes being specifically processed.
[0040] In one embodiment, the bit-reversal/scrambling instruction is used in the software on a processor chip-set implementing a central-office modem end of a DSL link (e.g. ADSL or VDSL). However, one skilled in the art will realize that the present invention is not limited to this implementation, but may be equally used in other contexts where data must be bit-reversed and scrambled in the same way, such as in a DSL CPE modem at the customer premise, or in systems not implementing DSL.
[0041] In one embodiment, the ATMSCR instruction takes as one input an 8-byte sequence of data bytes as a composite 64-bit value. Its second input is a 43-bit value holding the internal state of the scrambling process between consecutive sections of data being scrambled. In a preferred embodiment, this 43-bit state is equal to the last 43 bits of the previous output of the scrambling process (i.e. the result of a previous execution of the instruction to process the previous 8 bytes of payload data in the same data stream).
[0042] Thus, the 8 bytes of data each have their bit order reversed, thus satisfying the requirement for bit order change between external and internal versions of the bytes of each ATM cell, without requiring additional hardware in the modem circuits implementing the external data transfer. The payload data bytes are then scrambled using the defined scrambling method. In other words, the 64 bits of byte-reversed data are combined with the 43 bits of previous state to yield 64 bits of result. The 64 result bits are then written to the output operand.
[0043] More specific details of one embodiment of the operation performed by the ATMSCR instruction are described below:
tmp.<7..0>=BITREV(in.<7..0>) tmp.<15..8>=BITREV(in.<15..8>) tmp.<23..16>=BITREV(in.<23..16>) tmp.<31..24>=BITREV(in.<31..24>) tmp.<39..32>=BITREV(in.<39..32>) tmp.<47..40>=BITREV(in.<47..40>) tmp.<55..48>=BITREV(in.<55..48>) tmp.<63..56>=BITREV(in.<63..56>) out.<42..0>=tmp.<42..0>{circumflex over ( )}state.<63..21> out.<63..43>=tmp.<63..43>{circumflex over ( )}tmp.<20..0>{circumflex over ( )}state.<41..21>
[0054] In the above description, the meanings of the terms are defined as described below.
[0055] val.n (where val stands for any identifier such as tmp, state, etc. . . . and n stands for an integer, e.g. 45) means bit n of value val, where bit 0 is the least significant and earliest bit and bit 1 is the next more significant (more recent) bit, etc.
[0056] val.<m..n>means the linear bit sequence (val.m, val.(m−1), . . . val.n) considered as an ordered composite multi-bit entity where val.m is the most significant (and most recent) bit and val.n the least significant (and earliest) bit of the sequence.
[0057] BITREV(bseq) creates a new linear bit sequence by taking the bits of the linear bit sequence bseq in reverse order.
[0058] bseq1{circumflex over ( )}bseq2 means the linear bit sequence resulting from a parallel bit-wise operation where each bit of the linear bit sequence bseq1 is combined with the corresponding bit of linear bit sequence bseq2 using the logical “exclusive-or” function.
[0059] Referring now to FIG. 4 , there is shown a logic diagram of one embodiment of the ATMSCR instruction as it may be implemented within an execution unit of a processor. As will be understood by one skilled in the art, the diagram shows only the core functional logic implementing the specific details of the ATMSCR instruction; other non-specific aspects required to implement any processor (such as how the source data bits are directed from their respective registers to the specific logic function for a particular instruction, and how the result value is returned to the required register), are not shown.
[0060] In the embodiment in FIG. 4 , the gates shown are XOR gates. The first 21 bits of the state input are unused and not shown in FIG. 4 . The 64 bits of the “data” input appear in order at the left of the diagram; the 43 used bits from the “state” input appear in order in the middle of the diagram; and the 64 bits of the output value “out” are generated in order at the right side of the diagram.
[0061] In the wiring format used in FIG. 4 , a short gap is left in any horizontal wire which crosses but is not joined to a vertical wire to show that there is no connection between them. Any horizontal wire which crosses a number of vertical wires therefore appears as a dashed line.
[0062] One skilled in the art will realize that this is only one of many possible arrangements of the logic for the present invention. The present invention is not limited to this embodiment of the logic, but may apply to any logic arrangement that produces the same result. For example, in FIG. 4 , the logic size is minimized (compared with the logic description given above) in that the values for bits 63 . . . 43 of the output are shown calculated by re-using the values of the output bits 20 . . . 0 as inputs. However, it is equally valid (and in some implementations may be preferable, e.g. to keep an equal load on all output bits) to calculate them purely from the relevant bits of the state input and bit-reversed data inputs, as is expressed in the logic description above. One skilled in the art will also appreciate that other logic circuitry for implementing the present invention may be generated by using a logic-optimizing software program, such as “BuildGates” by Cadence Design Systems, Inc., which is given as input a top-level description of the logic function, i.e. comparable to the equations listed above. Thus, the present invention advantageously completes the whole bit reverse and scrambling operation for 8 bytes in a single cycle. As a result, the present invention advantageously increases the efficiency of bit reversing and scrambling data for subsequent modulation and use.
[0063] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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A method and apparatus are disclosed for efficiently bit-reversing and scrambling one or more bytes of payload data according to DSL standards on a processor. In one embodiment, this is achieved by providing an instruction for bit reversing and scrambling one or more bytes of data according to the DSL standards. Accordingly, the invention advantageously provides a processor with the ability to bit reverse and scramble data with a single instruction thus allowing for more efficient and faster scrambling operations for subsequent modulation and transmission.
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The present application is the national phase of International Application No. PCT/CN2013/073306, filed on Mar. 28, 2013, which claims the benefit of Chinese Patent Application No. 201210326293.3, titled “ELECTRICALLY CONTROLLED LOCKING APPARATUS” and filed with the Chinese State Intellectual Property Office on Sep. 5, 2012, which applications are hereby incorporated by reference to the maximum extent allowable by law.
FIELD OF THE INVENTION
The present application relates to a locking apparatus, and particularly to an electrically controlled locking apparatus for an oil port cover of an oil tank truck.
BACKGROUND OF THE INVENTION
With the popularization of cars in our country, fuel consumption has been greatly increased. Accordingly, the amount of fuel transported by oil tank trucks, as the core of the supply chain of gas stations and fuel consuming sites, has been greatly increased. Due to the high fuel price, recently, loopholes in oil tank truck management have been exploited by lawbreakers in their illegal activities. Apparently, since oil tank trucks are running on the road in most of the times, it is more difficult to ensure the operation security of the oil tank trucks than that of warehouses.
For solving these problems, supervisory departments progressively enhance management and technical measures to prevent such incidents. In the prior art, generally, physical label seal, electronic label seal or padlocks are used to restrict manually opening and closing the oil port. The principles of these preventive measures for restricting the illegal operations are as follows.
1. The physical label seal is to seal the oil port via a disposable label, and only the staff of the oil company are allowed to break the label in operation, thus if the label is broken by other people, it means that something wrong occurs.
2. The electronic label seal is to seal the oil port via an electronic label, which has the same working process as the physical label seal, and corresponding technical measures are required to break the electronic label seal.
3. The lock is a most simple padlock, and keys are kept by the staff of the oil company.
However, in view of the principles of the above measures, the lock and the physical label seal are easy to be destroyed and duplicated, and the electronic label seal may be disabled by lawbreakers by shorting out the electronic label seal or by other means. It is obvious that each of these measures has security flaws which can not be solved.
1. If the preventive measures are disabled, there is no system that can detect the destruction action.
2. The preventive measures rely on artificial operations excessively, and has to be combined with management method to be effective, thus there is a high risk of the managerial personnel being united to cheat.
3. The preventive measures do not have function of active defense, and has to rely on the staff operating by following specification.
Therefore, it is urgent to provide an electrically controlled locking apparatus for an oil port cover of an oil tank truck, which is not easy to be disabled and duplicated and is safe and reliable, so as to fundamentally prevent unlawful actions.
SUMMARY OF THE INVENTION
An object of the present application is to provide an electrically controlled locking apparatus for an oil port cover of an oil tank truck, which is not easy to be disabled or duplicated, and is safe and reliable.
The electrically controlled locking apparatus provided by the present application includes a safety housing provided with at least one cover; a rotating shaft provided in the housing, the rotating shaft being fixedly connected to a component to be locked and being configured to drive the component to be locked outside the housing to rotate; a locking sheet fixedly provided on the rotating shaft, the locking sheet being perpendicular to the rotating shaft and being provided with a pin control portion; a locking pin being configured to selectively engage with the pin control portion and being driven to rotate via a power motor; and a control portion being configured to control a rotation of the power motor according to a control instruction, such that the locking pin is controlled to be engaged with the pin control portion to lock the locking sheet and the component to be locked, or to be disengaged from the pin control portion to unlock the locking sheet and the component being locked.
Preferably, the locking sheet is a semicircular locking plate.
Further, the pin control portion is a notch provided at an edge of the semicircular locking plate for receiving the locking pin.
Preferably, the locking pin is fixed on a pin shaft, the pin shaft is driven by a driven wheel, and the driven wheel is engaged with a driving wheel driven by the power motor.
Further, an end, away from the locking sheet, of the pin shaft is fixedly connected with a blocking sheet.
Further, a blocking sheet detecting sensor is provided at each of two ends of a stroke of the blocking sheet rotating together with the pin shaft.
Preferably, an opening/closing state monitoring device is provided between the cover and the housing.
Further, the opening/closing state monitoring device includes a supporting plate and a self-returning pressing sheet mounted on a surface, facing the cover, of the supporting plate;
the self-returning pressing sheet is rotatably provided on the supporting plate via a rotating shaft, and includes one end extending towards the cover and forming a pressing end and the other end forming a detecting end; the rotating shaft is located between the pressing end and the detecting end; and a detecting sensor is provided in a stroke of the detecting end rotating around the rotating shaft.
Further, the self-returning pressing sheet realizes a self-returning function via a torsion spring coaxially provided relative to the self-returning pressing sheet.
Preferably, the control portion sends an operation instruction or an alarm signal according to a signal sent from the blocking sheet detecting sensor or the opening/closing state monitoring device.
Compared with the prior art, the electrically controlled locking apparatus provided by the present application has the following advantageous.
The apparatus may monitor and control the legal operation via the control portion, so as to effectively restrain illegal destruction and duplication, effectively monitor the state of the cover being not closed or being not fully closed, and avoid the potential risk caused by the electrically controlled locking apparatus being destroyed, thereby greatly preventing the oil tank truck from being illegally opened and preventing oil being stolen during the transportation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing an electrically controlled locking apparatus provided by the present application being used on an oil tank;
FIG. 2 is a perspective schematic view of an electrically controlled locking apparatus;
FIG. 3 is an exploded schematic view of the electrically controlled locking apparatus with a cover being opened;
FIG. 4 is an exploded schematic view showing an internal structure of the electrically controlled locking apparatus;
FIG. 5 is a sectional view of the electrically controlled locking apparatus shown in FIG. 2 taken along line A-A;
FIG. 6 is a sectional view of the electrically controlled locking apparatus shown in FIG. 2 taken along line B-B; and
FIG. 7 is a partial enlarged drawing of an area “F” in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
The technical solutions in the embodiments of the present application will be described clearly and completely hereinafter in conjunction with the drawings in the embodiments of the present application. Apparently, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all of other embodiments, made by the person skilled in the art without any creative efforts, fall into the protection scope of the present application.
Referring to FIG. 1 , an electrically controlled locking apparatus 2 is provided at an oil port of an oil tank 1 for controlling opening and closing of an oil port cover 11 , wherein FIG. 1 is only an illustrational view. It is well known that the oil tank 1 carried on a practical oil tank truck has a plurality of oil ports including oil inlets and oil outlets, thus a plurality of the electrically controlled locking apparatus 2 can be directly mounted at the oil inlets and the oil outlets of the oil tank 1 carried on the oil tank truck respectively.
Specifically, the oil port cover 11 is fixedly sleeved on a rotating shaft 201 extended out of the electrically controlled locking apparatus 2 , and the rotating shaft 201 includes a tail end movably connected to, via a bearing, a fixed wall 12 fixed on an outer surface of a housing of the oil tank. To avoid cheating, in installation, the electrically controlled locking apparatus 2 and the oil port cover 11 are integrally connected via a bolt or by welding, and also the electrically controlled locking apparatus 2 and the outer surface of the housing of the oil tank 1 are integrally connected via a bolt or by welding.
Referring to FIGS. 2 to 6 , an internal structure of the electrically controlled locking apparatus will be further illustrated by dividing it into parts. An external part of the electrically controlled locking apparatus includes a housing 202 and a cover 203 which are made from pressed steel plate. The housing 202 and the cover 203 are connected via a bolt 204 to close the housing 202 , and a sealing ring is provided between the housing 202 and the cover 203 , thereby forming a sealed cavity which is dustproof, waterproof, electromagnetic radiation-proof and explosion-proof. A rotating shaft 201 is provided in the housing 202 , and the rotating shaft 201 is fixedly connected to the oil port cover 11 to be locked and may drive the oil port cover 11 to be locked outside the housing 202 to rotate. A locking sheet 205 perpendicular to the rotating shaft 201 is fixedly provided on the rotating shaft 201 and is provided with a pin control portion 2051 . A locking pin 206 is further provided to selectively engage with the pin control portion 2051 , and the locking pin 206 is driven by a power motor 207 to rotate. A control portion (not shown) is further provided to control the rotation of the power motor 207 according to a control instruction, such that the locking pin 206 is controlled to be engaged with the pin control portion 2051 to lock the locking sheet 205 and the oil port cover 11 to be locked, or to be disengaged from the pin control portion 2051 to unlock the locking sheet 205 and the locked oil port cover 11 . Additionally, for electrically connecting the control portion to a main control system of a vehicle, a wire outlet hole for protruding of an electrical wire and a shaft outlet hole for protruding of the rotating shaft are provided at a side wall of the housing 202 . These holes are provided with sealing rings to be dustproof and waterproof.
In particularly, referring to FIG. 5 and FIG. 6 , the locking sheet 205 fixedly and perpendicularly provided on the rotating shaft 201 is a semicircular locking plate. A notch 2051 for receiving the locking pin 206 is provided at an edge of the semicircular locking plate. The locking pin 206 is fixed on a pin shaft 2061 , and the pin shaft 2061 is driven by a driven wheel 2062 which is engaged with a driving wheel 2063 driven by the power motor 207 . Working principle of the electrically controlled locking apparatus 2 will be further explained according to two position states of the locking sheet 205 shown in FIGS. 5 and 6 . FIG. 5 is a schematic drawing showing the position state of the locking sheet 205 when the oil port is closed by the oil port cover 11 , and at this point, the oil port cover 11 which is coaxially rotated with the locking sheet 205 is located at a position where the oil port is completely covered by the oil port cover 11 . Since the oil port cover 11 is coaxially rotated together with the locking sheet 205 , when opening or closing the oil port cover 11 , the rotating shaft 201 is driven by the oil port cover 11 to rotate, such that the locking sheet 205 is rotated together with the rotating shaft 201 . When the oil port cover 11 is fully closed, the notch 2051 on the locking sheet 205 arrives at a predetermined position, and at this point, the control portion controls the power motor 207 to rotate, so as to drive the locking pin 206 to engage with the notch 2051 , thereby realizing the purpose of locking the locking sheet 205 . After being locked, the locking sheet 205 can not rotate, thus the rotating shaft 201 can not rotate either, thereby realizing the function of locking the oil port cover 11 . If it is required to open the oil port cover 11 , the control portion controls the power motor 207 to rotate in the opposite direction, so as to drive the pin shaft 206 to rotate and to be disengaged from the notch 2051 , thereby realizing the purpose of unlocking the locking sheet 205 . When the locking sheet 205 is in an unlocked state, the locking sheet 205 can rotate freely, thus the rotating shaft 201 can also rotate freely, such that a function of unlocking the oil port cover 11 may be realized. The relationships between the components after being unlocked are shown in FIG. 6 .
Furthermore, for monitoring the opening/closing state of the corresponding oil port cover 11 , a locking sensor 31 and an opening sensor 32 for monitoring the locking pin 206 and an opening/closing state sensor 33 for monitoring the cover 203 are provided in the electrically controlled locking apparatus 2 . In particular, an end, away from the locking sheet 205 , of the pin shaft 2061 is fixedly connected with a blocking sheet 20611 . Two blocking sheet detecting sensors (i.e. the locking sensor 31 and the opening sensor 32 ) are respectively provided at two ends of a stroke of the blocking sheet 20611 rotating together with the pin shaft 2061 . The locking sensor 31 is provided at such a position that when the locking pin 206 is engaged with the notch 2051 for receiving the locking pin 206 , the blocking sheet 20611 enters the range of a U-shaped sensor of the locking sensor 31 . The opening sensor 32 is provided at such a position that when the locking pin 206 is completely disengaged from the notch 2051 for receiving the locking pin 206 , the blocking sheet 20611 enters the range of a U-shaped sensor of the opening sensor 32 . Thus, if it is required to open the oil port cover 11 , the control portion sends an instruction of opening, and the power motor 207 begins to rotate and drives the locking pin 206 to be disengaged from the notch 2051 . Then, the blocking sheet 20611 which is also located on the pin shaft 2061 as the locking pin 206 may rotate together with the pin shaft 2061 to leave the range of the locking sensor 31 . At this point, the locking sensor 31 may sense the leaving of the blocking sheet 20611 and informs the control portion of the detected state. Then, when the blocking sheet 20611 arrives in the range of the U-shaped sensor of the opening sensor 32 , the opening sensor 32 may sense the arriving of the blocking sheet 20611 and informs the control portion of the detected state. Then, according to the signal from the opening sensor 32 , the control portion sends an instruction of stopping the power motor 207 , and the power motor 207 stops immediately. At this time, the electrically controlled locking apparatus 2 is in an unlocked state, thus the oil port cover 11 can be opened. When it is required to close the oil port cover 11 , firstly, the oil port cover 11 is fully closed relative to the oil tank, and at this time the notch 2051 of the locking sheet 205 on the rotating shaft 201 is in a locking position, then the control portion sends an instruction of locking. After receiving the instruction, the power motor 207 begins to rotate and drives the locking pin 206 and the blocking sheet 20611 to rotate together. When the blocking sheet 20611 leaves the range of the opening sensor 32 , the opening sensor 32 informs the control portion of the detected state. Finally, when the locking pin 206 is engaged with the notch 2051 , that is the blocking sheet 20611 arrives the range of the locking sensor 31 , the locking sensor 31 detects the arriving of the blocking sheet 20611 and informs the control portion of the detected state information. According to the signal from the locking sensor 31 , the control portion sends an instruction of stopping the power motor 207 , and the power motor 207 stops immediately. At this point, the electrically controlled locking apparatus is in a locked state, and the oil port cover can not be opened.
In the case that the oil port cover 11 is not fully closed, or someone intentionally instructs to lock when the oil port cover is not fully closed, the locking sheet 205 is in the unlocking position due to the fact that the oil port cover is not fully closed, and the locking pin 206 can not make the predetermined stroke due to the fact that the locking sheet 205 is not at the right position, i.e. the notch 2051 is not at the proper position, therefore the blocking sheet 20611 can not rotate into the range of the locking sensor 31 within the specific time. At this time, the control portion may send a warning instruction due to the timeout of the locking operation, thus the administrator may immediately knows that an abnormal situation occurs on the oil port.
Furthermore, referring to FIG. 7 , in order to monitor illegal destruction of the electrically controlled locking apparatus 2 , an opening/closing state sensor 33 is provided between the cover 203 and the housing 202 . The opening/closing state sensor 33 can monitor the opening and closing states of the cover 203 of the electrically controlled locking apparatus. The opening/closing state sensor 33 includes a supporting plate 331 and a self-returning pressing sheet 332 mounted on a surface, facing the cover 203 , of the supporting plate 331 . The self-returning pressing sheet 332 is rotatably provided on the supporting plate 331 via a rotating shaft 333 , and has one end extending towards the cover and forming a pressing end 3321 and the other end forming a detecting end 3322 . The rotating shaft 333 is located between the pressing end 3321 and the detecting end 3322 . A detecting sensor 334 is provided in a stroke of the detecting end 3322 rotating around the rotating shaft 333 . The self-returning pressing sheet 332 realizes the self-returning function via a torsion spring 335 coaxially provided relative to the self-returning pressing sheet 332 .
When the cover 203 is opened, the self-returning pressing sheet 332 is not subjected to the force from the cover 203 , and under the action of the torsion spring 335 , the detecting end 3322 of the self-returning pressing sheet 332 leaves the range of the detecting sensor 334 . Then, the detecting sensor 334 informs the control portion of state information of the leaving of the detecting end 3322 , and a background is informed immediately that the cover 203 has been opened. If the cover 203 is closed, the pressing end 3321 of the self-returning pressing sheet 332 is pressed down by the cover 203 , and the detecting end 3322 is raised into the range of the detecting sensor 334 , then the detecting sensor 334 informs the control portion of state information of the arriving of the detecting end 3322 , and the control portion is immediately informed that the cover has been closed. Due to the opening/closing state sensor 33 , an object that the electrically controlled locking apparatus can not be disassembled without permission can be realized.
The above-described embodiments are only preferred embodiments of the present application. It should be noted that, for the person skilled in the art, many modifications and improvements may be made to the present application without departing from the principle of the present application, and these modifications and improvements are also deemed to fall into the protection scope of the present application.
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An electrical control lock device comprises: a safety casing which is provided at least one cover body; a rotating shaft, which is connected fixedly with a locked part and drives the locked part outside the casing to rotate, is provided in the casing; a locking plate which is perpendicular to said rotating shaft is arranged fixedly on the rotating shaft, and said locking plate is provided with a pin control portion; a lock pin which selectively drops into the pin control portion and said lock pin is driven by a power motor to rotate; and a control portion which controls the rotating of the power motor according to a guiding control instruction in order that the lock pin drops into the pin control portion to enable that the locking plate and the locked part are locked.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. App. No. 62/143,529 filed Apr. 6, 2015, which is entitled “Safety Gate for Rail Car” and which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND
Safety equipment and more particularly a safety gate for use with an open door in a mass transit vehicle to prevent a maintenance worker from accidentally falling out the open door are disclosed herein.
Mass transit vehicle doors, for example rail car doors, and particularly doors employed in electrified cars such as subway cars or other mass transit rail cars, are automatically actuated to open and close, as is known in the art. As with any automated or mechanical apparatus the doors require regular maintenance or repair. During maintenance and repair of the doors the vehicle is taken out of service. Often the vehicle is transported to a yard for service. In many cases a vehicle door is opened and maintenance or repair personnel are positioned in the open doorway when working on the door, which exposes the worker to the possibility of falling out the open door, resulting in injury. It would be advantageous, therefore, to have a safety gate that can be installed in the door opening to prevent such falls. It also would be advantageous if the gate were light weight, transportable, easy to install and to remove and if it were easily adaptable to different size openings.
Moreover, the vehicle being serviced or repaired may be parked on rails having an electrified third rail, either on the track or in the yard. It would be advantageous if the safety gate is not electrically conductive, comprised of dielectric material so that inadvertent contact with an electrified rail does not pose a risk of electrocution or system shutdown.
BRIEF SUMMARY
An expandable safety gate for a vehicle door opening comprising a first substantially rectangular frame and a second substantially rectangular frame slidingly engaged in the first frame such that the two frames are positioned in the same vertical plane, the second frame being extendable from the first frame to be fitted to different sized rail car door openings. There are locking mechanisms to secure the second frame relative to the first frame in its useful extended position within the opening.
The safety gate is comprised of dielectric material, such as fiberglass or other non-conductive material, is lightweight, portable and easily installed and removed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a front plan view of an aspect of the safety gate mounted in an open doorway;
FIG. 2 is another front plan view of the gate;
FIG. 3 is a front perspective view thereof;
FIG. 4 is an end plan view; and
FIG. 5 is a top plan view thereof.
Corresponding reference numerals will be used throughout the several figures of the drawings.
DETAILED DESCRIPTION
The following detailed description illustrates the safety gate by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the claimed invention, and describes several embodiments, adaptations, variations, alternatives and uses of the claimed invention, including what I presently believe is the best mode of carrying out the claimed invention. Additionally, it is to be understood that the safety gate is not limited in its application to the details of construction and the arrangements of components or the dimensions set forth in the following description or illustrated in the drawings. The safety gate is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
Referring to the drawings, and particularly FIG. 1 , one aspect of a safety gate is referred to generally by number 10 . As shown, the gate 10 is installed in the opening O of a vehicle door. The vehicle can be any vehicle, such as a mass transit vehicle or rail car, for example, a rail car in a rapid transit or subway line. It will be understood, however, that gate 10 may be used in any environment to block an opening and prevent accidental or unintended egress through the opening, such as a fall out of the opening.
The gate 10 includes a first substantially rectangular frame 12 and a second substantially rectangular frame 14 at one end of the first frame. The first frame 12 includes a first vertical end post 16 and an opposed second vertical end post 18 . In the illustrated aspect, there are four horizontal frame members, 20 , 22 , 24 and 26 extending between the end posts 16 , 18 . At least the upper and lower most horizontal frame members 20 and 26 define inner channels and have a larger cross-sectional area than the middle frame members 22 and 24 .
There is an upper mounting bracket 28 at the top of first end post 16 and a lower mounting bracket 30 at the bottom of end post 16 . Each mounting bracket includes a transverse slot 32 and can be attached to the vehicle wall W adjacent the opening O. A fastener 34 extends through the slot 32 and engages the post 16 to secure the post to the brackets. In one aspect, the fastener 34 can be a knob having a threaded extension that engages a threaded hole in the post. However, any fastener that conveniently and easily attached the post to the brackets may be employed.
The second rectangular frame 14 includes a vertical end post 36 , an upper horizontal frame member 38 , a center horizontal frame member 40 and a lower horizontal frame member 42 . As shown, the upper frame member 38 and the lower frame member 42 are aligned with and dimensioned to slidingly engage inside the horizontal frame members 20 and 26 , respectively, of the first rectangular frame. In one aspect, the center frame member 40 can define an externally threaded rod which extends through an opening (not seen) in the second end post 18 and through a locking device 46 located on the second end post 18 . In the illustrated aspect, the locking mechanism 46 can be a handle with a threaded bore that engages the external threads on member 40 . For example, the locking device 46 can be rotatably mounted to the second end post, such that as the locking device is rotated, the engagement of the threaded rod with the threads of the locking device cause the second frame to move axially relative to the first frame. Alternatively, locking mechanism 46 can employ a swaged arrangement that does not require threads on center frame member 40 . Any locking mechanism will suffice.
There is an upper mounting bracket 48 at the top of first end post 36 and a lower mounting bracket 50 at the bottom of end posts 36 . Each mounting bracket includes a transverse slot 52 and can be attached to the vehicle wall W adjacent opening O. A fastener 54 extends through slot 52 and engages post 36 to secure the post to the brackets.
In use, the width of the gate 10 can be adjusted to accommodate different widths of openings O. Brackets 28 , 30 , 48 and 50 can be removably secured to the wall W. Fasteners 34 and 54 are loosened and vertical end posts 16 and 36 are positioned adjacent the vertical walls of opening O. Because the upper frame member 38 and the lower frame member 42 of the second rectangular frame are slidingly engaged inside horizontal frame members 20 and 26 , respectively, of the first rectangular frame 12 , the second rectangular frame 14 can be extended or retracted laterally relative to the first rectangular frame to fit within the opening O. The gate 10 is optimally positioned in opening O, fasteners 34 and 54 are tightened and the locking mechanism 46 is secured around horizontal member 40 to secure the gate in place.
To remove the gate, brackets 28 , 30 , 48 and 50 can be removed from wall W. Alternatively, the fasteners 34 and 54 can be removed from the gate to release gate 10 from the vehicle, leaving the brackets 32 and 54 in place for future use.
The general dimensions of the various elements are relative and they are configured and dimensioned to fit in any desired opening. In one aspect, the various elements comprise a non-conductive material such as fiberglass or other resin. If the gate is to be installed where there is no exposure to electric current, the various elements may comprise another lightweight and durable material such as light gauge steel, aluminum or alloys.
In view of the above, it will be seen that the several objects and advantages of the present invention have been achieved and other advantageous results have been obtained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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An expandable safety gate for a vehicle door opening comprising a first substantially rectangular frame and a second substantially rectangular frame slidingly engaged in the first frame such that the two frames are positioned in the same vertical plane, the second frame being extendable from the first frame to fit within the door opening; and locking mechanisms to secure the second frame in its extended position within the vehicle door opening, wherein safety gate is comprised of non-conductive material.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-208720, filed on Aug. 10, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor memory device such as EEPROMs of the NAND-cell, NOR-cell, DINOR (Divided bit line NOR)-cell and AND-cell types, and more particularly to a semiconductor memory device having an improved sense amplifier of the current sense type.
2. Description of the Related Art
A sense amplifier in a semiconductor memory device such as a flash memory basically senses the presence/absence or the level of cell current flowing in accordance with data in a memory cell, thereby deciding the value of data. The sense amplifier is usually connected to a bit line (data line) to which a number of memory cells are connected. The sensing scheme is roughly divided into the voltage sense type and the current sense type.
A sense amplifier of the current sense type precharges a bit line isolated from the memory cells to a certain voltage, discharges the bit line through the selected memory cell, and detects the discharged state of the bit line at a sense node connected to the bit line. At the time of data sensing, the bit line is isolated from the current source load to detect the bit line voltage determined from cell data.
A sense amplifier of the voltage sense type, on the other hand, supplies read current flowing in a memory cell via the bit line, thereby sensing data. Also in this case, cell data determines the bit line voltage, and eventually data determination at the sense node connected to the bit line detects a difference in voltage at the sense node based on the difference in cell current.
The sense amplifier of the current sense type and the sense amplifier of the voltage sense type have the following advantages and disadvantages in general. The voltage sense type utilizes charging and discharging bit lines and accordingly has less power consumption. In a mass storage memory with a large bit line capacity, though, charging/discharging is time-consuming and accordingly fast sensing becomes difficult. In addition, the amplitude of the bit line voltage is made relatively large in accordance with cell data and accordingly a noise between adjacent bit lines causes a problem.
In contrast, the sense amplifier of the current sense type senses data while supplying read current flowing in the memory cell via the bit line, thereby enabling fast sensing. In addition, a clamp transistor (presense amplifier) arranged between the bit line and the sense node is used to reduce the amplitude of the bit line voltage in accordance with cell data and accordingly the noise between bit lines hardly causes a problem. Also in this case, however, reading is executed on alternate bit lines, and other bit lines not subjected to reading are grounded and used as shields to exclude influences between bit lines on reading.
To the contrary, the bit line potential may be controlled such that it is always fixed at a constant voltage to exclude influences between bit lines and allow all bit lines to be sensed in parallel on sensing. Such a sense amplifier of the ABL (All Bit Line) type has been proposed (JP 2006-500729T, paragraphs 0062-0068, 0076-0079, FIGS. 7A , 7 B, 8 and 13 ).
In such the sense amplifier of the current sense type, however, advanced fine patterning of devices increases the value of current flowing in the cell source line and elevates the potential on the cell source line as a problem. The elevation of the potential on the cell source line decreases the potential difference between the bit line controlled at a certain potential by a clamp transistor and the cell source line. Accordingly, the drain-source voltage Vds in the selected cell lowers and the gate-source voltage Vds in the selected cell also lowers. As a result, the cell current decreases and causes a failure in reading data out of the selected cell.
To prevent such the read failure, there has been proposed a method called multipath sense, which comprises multiple times of sensing (Patent Document 1). The multipath sense is a method comprising turning off the selected cell after once sense current flows therein at the first sensing, followed by sensing again. Thus, the value of current flowing in the cell source line is suppressed lower than the first sensing and the subsequent sensing can correctly detect the sense current flowing in the selected cell that could not be detected in the previous sensing.
The multipath sense, however, requires multiple times of sensing and accordingly consumes time in sensing as a problem. In particular, storing multivalue data such as 8-value or 16-value data in a memory cell increases times of sensing to 7 or 15. Accordingly, the requirement of multiple times of sensing in a single threshold decision causes a fatal drawback with respect to the reading time.
On the other hand, a control may be considered to elevate the gate voltage on the bit-line clamp transistor in accordance with the elevation of the potential on the cell source line. In this case, however, the potential on the cell source line differs from part to part in the memory cell array. Accordingly, the voltage control of bit lines together causes an excessively controlled bit line and a less controlled bit line as a problem.
SUMMARY OF THE INVENTION
In one aspect the present invention provides a semiconductor memory device, comprising: a memory cell array having plural memory cells connected between a bit line and a cell source line; a sense amplifier of the current sense type operative to initially charge the bit line with a charging voltage controlled by a bit-line control signal and detect the value of current flowing in the bit line when a certain gate voltage is given to a data read-targeted memory cell to decide data read out of the memory cell; and a bit-line control signal generator circuit operative to receive the voltage on the cell source line, generate the bit-line control signal in accordance with the received voltage on the cell source line and provide it to the sense amplifier, wherein the memory cell array forms a plurality of control areas in a direction orthogonal to the direction of extension of the bit line, wherein the sense amplifier initially charges a bit line in each control area in the memory cell array with a charging voltage controlled by a respective individual bit-line control signal, wherein the bit-line control signal generator circuit is one of plural bit-line control signal generator circuits provided in accordance with the control areas in the memory cell array, wherein each bit-line control signal generator circuit receives the potential on the cell source line in a corresponding control area, individually generates and provides the bit-line control signal in the each control area in accordance with the received voltage on the cell source line in each control area.
In one aspect the present invention provides a semiconductor memory device, comprising: a memory cell array having plural memory cells connected between a bit line and a cell source line; a sense amplifier of the current sense type operative to initially charge the bit line with a charging voltage controlled by a bit-line control signal and detect the value of current flowing in the bit line when a certain gate voltage is given to a data read-targeted memory cell to decide data read out of the memory cell; and a bit-line control signal generator circuit operative to receive the voltage on the cell source line, generate the bit-line control signal in accordance with the received voltage on the cell source line and provide it to the sense amplifier, wherein the memory cell array and the sense amplifier are divided into M areas (M is an integer of 3 or more), wherein the bit-line control signal generator circuit receives the voltage on the cell source line in each of the M areas of the memory cells, generates the bit-line control signal in accordance with the received voltage on the cell source line in each area, and supplies the generated bit-line control signal to the sense amplifier in each area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the major part of a NAND-type flash memory according to one embodiment of the present invention.
FIG. 2 is a circuit diagram of a memory cell array in the same memory.
FIG. 3 is a circuit diagram of a sense amplifier in the same memory.
FIG. 4 is a waveform diagram showing operation of the sense amplifier in the same memory.
FIG. 5 is a circuit diagram of a BLC generator circuit in the same memory.
FIG. 6 is a circuit diagram of a PG generator circuit in the same memory.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The embodiments of the invention will now be described with reference to the drawings.
FIG. 1 is a block diagram showing the major part of a semiconductor memory device according to one embodiment of the present invention. This semiconductor memory device is a NAND-type flash memory, which comprises: a memory cell array 1 ; a row decoder 2 operative to select a word line and a selection gate line in the memory cell array 1 ; a sense amplifier 3 provided atone end or both ends in a bit line BL (described later) direction in the memory cell array 1 and operative to read data via the bit line BL; a plurality of BLC (bit-line control signal) generator circuits 4 provided in parallel with the sense amplifier 3 ; and a PG generator circuit 5 operative to supply a control signal PG to the BLC generator circuits 4 .
The memory cell array 1 comprises a plurality of NAND cell units NU arrayed in matrix as shown in FIG. 2 . A NAND cell unit NU includes: a memory cell string of plural memory cells M 1 -Mn serially connected in such a manner that adjacent ones share a source/drain diffused layer; a selection gate transistor S 1 connected between one end of the memory cell string and the bit line BL; and a selection gate transistor S 2 connected between the other end of the memory cell string and a cell source line CELSRC. Control gates of the memory cells M 0 to Mm- 1 are connected in such a manner that control gates of memory cells arrayed in the lateral direction are connected in common to form word lines WL 0 -WLn. Control gates of the selection gate transistors S 1 , S 2 are connected in such a manner that control gates of selection gate transistors arrayed in the lateral direction are connected in common to form selection gate lines SGD, SGS.
A set of NAND cell units NU arrayed in the word line WL direction configures a block or the minimum unit of data erase and plural such blocks BLK 0 -BLKm- 1 are arranged in the bit line direction. The memory cell array 1 is divided into plural areas in the direction of extension of the word line WL to form plural control areas CA.
The sense amplifier 3 may be configured as shown in FIG. 3 . In this case, a sense amplifier of the ABL type is described below by way of example though the present invention is not particularly limited to the sense amplifier of this type.
The sense amplifier 3 mainly includes: an initial charging circuit 31 capable of initially charging the bit line BL and a sense node SEN: a sensing capacitor 32 connected to the sense node SEN; a current discriminating circuit 33 operative to detect the value of current flowing in the bit line BL based on the potential on the sense node SEN; a latch 34 operative to hold an output from the current discriminating circuit 33 as read data; a discharging circuit 35 operative to discharge the charge stored on the bit line BL and the sense node SEN; and a bit line selection transistor 36 operative to selectively connect the sense amplifier 3 with the bit line BL.
The initial charging circuit 31 includes a charge switch PMOS transistor 312 connected to the power source VDD to switch on/off the charging current. The source of the PMOS transistor 312 is directly connected to the power source VDD. A PMOS transistor 314 and an NMOS transistor 315 are serially connected between the drain of the PMOS transistor 312 and the sense node SEN. A serial circuit of an NMOS transistor 316 and an NMOS transistor 317 for voltage clamp is interposed between the sense node SEN and the bit line selection transistor 36 . An NMOS transistor 318 is connected in parallel with the serial circuit of the NMOS transistors 315 , 316 . Namely, the NMOS transistor 315 supplies initial charging current to the sense node SEN. The NMOS transistor 316 supplies current from the sense node SEN to the bit line BL. The NMOS transistor 318 continuously supplies current to the bit line BL not via the sense node SEN. The NMOS transistor 317 is connected between the NMOS transistors 316 , 318 and the bit line BL and used in voltage clamping. The NMOS transistors 315 , 316 , 318 switch the charging/discharging paths to the bit line BL and the sense node SEN. When the current discriminating circuit 33 detects the potential on the sense node SEN, the NMOS transistor 315 is turned “off” and the NMOS transistor 318 is turned “on”.
The current discriminating circuit 33 includes a PMOS transistor 331 for detecting the sense node SEN, and a PMOS transistor 332 connected between the source of the transistor 331 and the power source VDD and operative at latch timing. Connected to the drain of the PMOS transistor 331 is the latch 34 , which includes CMOS inverters 341 , 342 connected in antiparallel. The latch 34 has an output linked to a read bus, not shown. The discharging circuit 35 includes a serial circuit of NMOS transistors 351 , 352 .
The sense amplifier 3 has operation periods of precharge, sense, data latch and discharge. FIG. 4 is a timing chart during a precharge period. To start precharging, first, a control signal INV supplied to the gate of the PMOS transistor 314 is at the low level, and control signals H 00 , XX 0 supplied to the gates of the NMOS transistors 315 , 316 are at the high level (not shown). In this situation, control signals BLC, BLX supplied to the gates of the NMOS transistors 317 , 318 rise to a certain voltage that can transfer the power source VDD to the bit line BL. Subsequently, a control signal BLS supplied to the gate of the bit line selection transistor 36 rises and a control signal BLT fed to the gate of the PMOS transistor 312 falls. As a result, the transistors 312 , 314 , 315 - 318 and 36 turn on and allow charging current to flow in the bit line BL and the sense node SEN via two paths of the transistors 315 , 316 and the transistor 318 .
If the selected cell stores “0” data in the NAND cell unit NU connected to the bit line BL, no on-current flows in the NAND cell unit NU. Therefore, the potential on the bit line BL becomes V BLC −Vth, which is equal to the voltage V BLC of the bit-line control signal BLC supplied to the gate of the voltage clamp transistor 317 minus the threshold Vth of the transistor 317 . If the selected cell stores “1” data (erased), a certain current flows in the selected cell and the potential on the bit line BL becomes lower than that when the selected cell stores “0” data.
After completion of the precharge period, the transistor 315 is turned off and the charge stored on the sense node SEN is discharged via the bit line BL and the selected cell if the selected cell holds data “1”. Subsequently, the value of current flowing in the bit line BL via the transistor 318 is controlled. As a result, the bit line BL is kept always at a constant potential to exclude influences to adjacent bit lines. Thereafter, the potential on the sense node SEN is sensed to decide data stored in the selected cell. The decided data is latched in the latch 34 and provided to external via the data line. Subsequently, the charge on the bit line BL and the sense node SEN is discharged via the discharging circuit 35 .
During the precharge period and on sensing, the current flowing in the bit line BL flows into the cell source line CELSRC in a stroke, thereby elevating the potential on the cell source line CELSRC. Therefore, the BLC generator circuit 4 cooperates with the PG generator circuit 5 to generate the bit-line control signal BLC of the voltage in accordance with the voltage on the cell source line CELSRC and supplies it to the gate of the clamp transistor 317 in the sense amplifier 3 . Namely, in accordance with the elevation of the voltage on the cell source line CELSRC, the voltage of the control signal BLC is also allowed to rise.
In this embodiment, monitor positions on the cell source line CELSRC are arranged one by one in the control areas CA of the memory cell array 1 and each BLC generator circuit 4 individually controls the bit-line control signal BLC in each control area CA. Namely, the current flowing in the bit line BL elevates the voltage on the cell source line CELSRC as shown in FIG. 4 . Accordingly, the cell source voltage is observed individually in each control area CA and, based on this result, the bit-line control signals BLC 1 , BLC 2 , . . . are controlled individually.
FIG. 5 shows a specific configuration example of the BLC generator circuit 4 , and FIG. 6 shows a specific configuration example of the PG generator circuit 5 . The PG generator circuit 5 comprises a constant current circuit, which includes a serial circuit of a PMOS transistor 51 and resistors 52 , 53 , and an operational amplifier 54 operative to supply the control signal PG to the gate of the PMOS transistor 51 to control the transistor 51 such that the voltage drop across the resistor 53 caused by the current flowing in the serial circuit meets the reference voltage VREF. The BLC generator circuit 4 comprises a serial circuit of a PMOS transistor 41 , a diode-connected NMOS transistor 42 , and a resistor 43 . The PMOS transistor 41 has a gate given the control signal PG to supply a constant current flowing in the resistor 43 and the resistor 43 has one end connected to the cell source line CELSRC. It is configured such that as the voltage on the cell source line CELSRC rises or falls, the potential on the point of connection between the PMOS transistor 41 and the NMOS transistor 42 also rises or falls. The point of connection between the transistors 41 , 42 is used as the output of the bit-line control signal BLC.
The BLC generator circuit 4 is configured in other words as follows. Namely, the NMOS transistor 42 and the resistor 43 serve as a resistor element, which has one end supplied with the voltage on the cell source line CELSRC and the other end used as the output terminal of the bit-line control signal BLC. The PMOS transistor 41 supplies a constant current in the NMOS transistor 42 and the resistor 43 (resistor element).
The PG generator circuit 5 is configured in other words as follows. Namely, the PG generator circuit 5 supplies the control signal PG for constant current to the gate of the PMOS transistor 41 . The PG generator circuit 5 supplies the control signal PG to the BLC generator circuits 4 in common. In the PG generator circuit 5 , the PMOS transistor 51 , the resistors 52 , 53 , and the operational amplifier 54 configure a current mirror paired with the PMOS transistor 41 in the BLC generator circuit 4 .
In this embodiment, the BLC generator circuit 4 is provided in each control area CA in the memory cell array 1 , and the bit-line control signal BLC is generated individually for each control area CA to control the voltage on the bit line BL generated by the sense amplifier 3 . Accordingly, it is possible to prevent the fluctuation of the cell source line CELSRC from causing a read error in each control area CA. In addition, this embodiment makes it possible to read all data by single sensing, which can reduce the read time greatly over the multipath method.
Desirably, the number of the control areas CA formed through division of the memory cell array 1 is equal to 3 or more. The number of the BLC generator circuits 4 is preferably equal to 3 or more though it is not required to meet the number of the control areas CA. The BLC generator circuit 4 may be one that can control one or more control areas CA.
The BLC generator circuits 4 are arranged at one end or both ends of the memory cell array 1 in the direction of extension of the bit line BL as is preferable from the viewpoint of layout.
The above embodiments describe the NAND-type flash memory by way of example. The present invention is though not limited to the NAND-type flash memory but rather can be applied to semiconductor memory devices such as EEPROMs of the NOR type, the DINOR (Divided bit line NOR) type and the AND type as well.
|
A memory cell array forms a plurality of control areas in a direction orthogonal to the direction of extension of a bit line. A sense amplifier initially charges a bit line in each control area in the memory cell array with a charging voltage controlled by a respective individual bit-line control signal. Bit-line control signal generator circuits are provided plural in accordance with the control areas in the memory cell array. Each bit-line control signal generator circuit receives the potential on a cell source line in a corresponding control area, individually generates and provides the bit-line control signal in the each control area in accordance with the received voltage on the cell source line in each control area.
| 6
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/618,786, filed Sep. 14, 2012, which is a continuation of U.S. patent application Ser. No. 12/847,719, filed Jul. 30, 2010, now U.S. Pat. No. 8,288,515, which claims the benefit of U.S. Provisional Application No. 61/230,557, filed Jul. 31, 2009, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to processes for the synthesis of the Factor Xa anticoagulent Fondaparinux, and related compounds. The invention also relates to protected pentasaccharide intermediates and to an efficient and scalable process for the industrial scale production of Fondaparinux sodium by conversion of the protected pentasaccharide intermediates via a sequence of deprotection and sulfonation reactions.
BACKGROUND OF THE INVENTION
[0003] In U.S. Pat. No. 7,468,358, Fondaparinux sodium is described as the “only anticoagulant thought to be completely free of risk from HIT-2 induction.” The biochemical and pharmacologic rationale for the development of a heparin pentasaccharide in Thromb. Res., 86(1), 1-36, 1997 by Walenga et al. cited the recently approved synthetic pentasaccharide Factor Xa inhibitor Fondaparinux sodium. Fondaparinux has also been described in Walenga et al., Expert Opin. Investig. Drugs , Vol. 11, 397-407, 2002 and Bauer, Best Practice & Research Clinical Hematology , Vol. 17, No. 1, 89-104, 2004.
[0004] Fondaparinux sodium is a linear octasulfated pentasaccharide (oligosaccharide with five monosaccharide units) molecule having five sulfate esters on oxygen (O-sulfated moieties) and three sulfates on a nitrogen (N-sulfated moieties). In addition, Fondaparinux contains five hydroxyl groups in the molecule that are not sulfated and two sodium carboxylates. Out of five saccharides, there are three glucosamine derivatives and one glucuronic and one L-iduronic acid. The five saccharides are connected to each other in alternate α and β glycosylated linkages (see FIG. 1 ).
[0005] Fondaparinux sodium is a chemically synthesized methoxy derivative of the natural pentasaccharide sequence, which is the active site of heparin that mediates the interaction with antithrombin (Casu et al., J. Biochem., 197, 59, 1981). It has a challenging pattern of O- and N-sulfates, specific glycosidic stereochemistry, and repeating units of glucosamines and uronic acids (Petitou et al., Progress in the Chemistry of Organic Natural Product, 60, 144-209, 1992).
[0006] The monosaccharide units comprising the Fondaparinux molecule are labeled as per the convention in FIG. 1 , with the glucosamine unit on the right referred to as monosaccharide A and the next, an uronic acid unit to its left as B and subsequent units, C, D and E respectively. The chemical synthesis of Fondaparinux starts with monosaccharides of defined structures that are themselves referred to as Monomers A2, B1, C, D and E, for differentiation and convenience, and they become the corresponding monosaccharides in fondaparinux sodium.
[0007] Due to this complex mixture of free and sulfated hydroxyl groups, and the presence of N-sulfated moieties, the design of a synthetic route to Fondaparinux requires a careful strategy of protection and de-protection of reactive functional groups during synthesis of the molecule. Previously described syntheses of Fondaparinux all adopted a similar strategy to complete the synthesis of this molecule. This strategy can be envisioned as having four stages. The strategy in the first stage requires selective de-protection of five out of ten hydroxyl groups. During the second stage these five hydroxyls are selectively sulfonated. The third stage of the process involves the de-protection of the remaining five hydroxyl groups. The fourth stage of the process is the selective sulfonation of the 3 amino groups, in the presence of five hydroxyl groups that are not sulfated in the final molecule. This strategy can be envisioned from the following fully protected pentasaccharide, also referred to as the late-stage intermediate.
[0000]
[0008] In this strategy, all of the hydroxyl groups that are to be sulfated are protected with an acyl protective group, for example, as acetates (R═CH 3 ) or benzoates (R=aryl) (Stages 1 and 2) All of the hydroxyl groups that are to remain as such are protected with benzyl group as benzyl ethers (Stage 3). The amino group, which is subsequently sulfonated, is masked as an azide (N 3 ) moiety (Stage 4). R 1 and R 2 are typically sodium in the active pharmaceutical compound (e.g., Fondaparinux sodium).
[0009] This strategy allows the final product to be prepared by following the synthetic operations as outlined below:
[0010] a) Treatment of the late-stage intermediate with base to hydrolyze (deprotect) the acyl ester groups to reveal the five hydroxyl groups. The two R 1 and R 2 ester groups are hydrolyzed in this step as well.
[0000]
[0011] b) Sulfonation of the newly revealed hydroxyl groups.
[0000]
[0012] c) Hydrogenation of the O-sulfated pentasaccharide to de-benzylate the five benzyl-protected hydroxyls, and at the same time, unmask the three azides to the corresponding amino groups.
[0000]
[0013] d) On the last step of the operation, the amino groups are sulfated selectively at a high pH, in the presence of the five free hydroxyls to give Fondaparinux ( FIG. 1 ).
[0014] While the above strategy has been shown to be viable, it is not without major drawbacks. One drawback lies in the procedure leading to the fully protected pentasaccharide (late stage intermediate), especially during the coupling of the D-glucuronic acid to the next adjacent glucose ring (the D-monomer to C-monomer in the EDCBA nomenclature shown in FIG. 1 ). Sugar oligomers or oligosaccharides, such as Fondaparinux, are assembled using coupling reactions, also known as glycosylation reactions, to “link” sugar monomers together. The difficulty of this linking step arises because of the required stereochemical relationship between the D-sugar and the C-sugar, as shown in FIG. 2 .
[0015] The stereochemical arrangement illustrated in FIG. 2 is described as having a β-configuration at the anomeric carbon of the D-sugar (denoted by the arrow). The linkage between the D and C units in Fondaparinux has this specific stereochemistry. There are, however, competing β- and α-glycosylation reactions.
[0016] The difficulties of the glycosylation reaction in the synthesis of Fondaparinux is well known. In 1991 Sanofi reported a preparation of a disaccharide intermediate in 51% yield having a 12/1 ratio of β/α stereochemistry at the anomeric position (Duchaussoy et al., Bioorg . & Med. Chem. Lett., 1(2), 99-102, 1991). In another publication (Sinay et al., Carbohydrate Research, 132, C5-C9, 1984) yields on the order of 50% with coupling times on the order of 6-days are reported. U.S. Pat. No. 4,818,816 (see e.g., column 31, lines 50-56) discloses a 50% yield for the β-glycosylation.
[0017] Alchemia's U.S. Pat. No. 7,541,445 is even less specific as to the details of the synthesis of this late-stage Fondaparinux synthetic intermediate. The '445 patent discloses several strategies for the assembly of the pentasaccharide (1+4, 3+2 or 2+3) using a 2-acylated D-sugar (specifically 2-allyloxycarbonyl) for the glycosylation coupling reactions. However, Alchemia's strategy involves late-stage pentasaccharides that all incorporate a 2-benzylated D-sugar. The transformation of acyl to benzyl is performed either under acidic or basic conditions. Furthermore, these transformations, using benzyl bromide or benzyl trichloroacetimidate, typically result in extensive decomposition and the procedure suffers from poor yields. Thus, such transformations (at a disaccharide, trisaccharide, and pentasaccharide level) are typically not acceptable for industrial scale production.
[0018] Examples of fully protected pentasaccharides are described in Duchaussoy et al., Bioorg. Med. Chem. Lett., 1 (2), 99-102, 1991; Petitou et al., Carbohydr. Res., 167, 67-75, 1987; Sinay et al., Carbohydr. Res., 132, C5-C9, 1984; Petitou et al., Carbohydr. Res., 1147, 221-236, 1986; Lei et al., Bioorg. Med. Chem., 6, 1337-1346, 1998; Ichikawa et al., Tet. Lett., 27(5), 611-614, 1986; Kovensky et al., Bioorg. Med. Chem., 1999, 7, 1567-1580, 1999. These fully protected pentasaccharides may be converted to the O- and N-sulfated pentasaccharides using the four steps (described earlier) of: a) saponification with LiOH/H 2 O 2 /NaOH, b) O-sulfation by an Et 3 N—SO 3 complex; c) de-benzylation and azide reduction via H 2 /Pd hydrogenation; and d) N-sulfation with a pyridine-SO 3 complex.
[0019] Even though many diverse analogs of the fully protected pentasaccharide have been prepared, none use any protective group at the 2-position of the D unit other than a benzyl group. Furthermore, none of the fully protected pentasaccharide analogs offer a practical, scaleable and economical method for re-introduction of the benzyl moiety at the 2-position of the D unit after removal of any participating group that promotes β-glycosylation.
[0020] Furthermore, the coupling of benzyl protected sugars proves to be a sluggish, low yielding and problematic process, typically resulting in substantial decomposition of the pentasaccharide (prepared over 50 synthetic steps), thus making it unsuitable for a large [kilogram] scale production process.
[0000]
[0021] It has been a general strategy for carbohydrate chemists to use base-labile ester-protecting group at 2-position of the D unit to build an efficient and stereoselective β-glycosidic linkage. To construct the β-linkage carbohydrate chemists have previously acetate and benzoate ester groups, as described, for example, in the review by Poletti et al., Eur. J. Chem., 2999-3024, 2003.
[0022] The ester group at the 2-position of D needs to be differentiated from the acetate and benzoates at other positions in the pentasaccharide. These ester groups are hydrolyzed and sulfated later in the process and, unlike these ester groups, the 2-hydroxyl group of the D unit needs to remain as the hydroxyl group in the final product, Fondaparinux sodium.
[0023] Some of the current ester choices for the synthetic chemists in the field include methyl chloro acetyl and chloro methyl acetate [MCA or CMA]. The mild procedures for the selective removal of theses groups in the presence of acetates and benzoates makes them ideal candidates. However, MCA/CMA groups have been shown to produce unwanted and serious side products during the glycosylation and therefore have not been favored in the synthesis of Fondaparinux sodium and its analogs. For by-product formation observed in acetate derivatives see Seeberger et al., J. Org. Chem., 2004, 69, 4081-93. Similar by-product formation is also observed using chloroacetate derivatives. See Orgueira et al., Eur. J. Chem., 9(1), 140-169, 2003.
[0024] Therefore, as will be appreciated, there are several limitations to current processes used for the synthesis of fondaparinux sodium. Thus, there is a need in the art for new synthetic procedures that produce fondaparinux and related compounds in high yield and with high stereoselectivity. The processes of the present invention address the limitations known in the art and provide a unique, reliable and scalable synthesis of compounds such as Fondaparinux sodium.
[0025] Additional advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
SUMMARY OF THE INVENTION
[0026] Applicants have surprisingly found that in the synthesis of Fondaparinux, the use of a unique levulinate-protected 2-glucuronic acid-anhydro sugar coupling methodology allows for a highly efficient glycosylation reaction, thereby providing late stage intermediates or oligosaccharides (and Fondaparinux related oligomers) in high yield and in high β/α ratios. In particular, glycosylation of the 2-levulinate-protected glucuronic acid can occur with high coupling yields (>65%) of the β-isomer, rapidly (for example, in an hour reaction time), and with no detectable α-isomer upon column chromatography purification. The levulinate protecting group may be efficiently and selectively removed from the glycosylated product in the presence of potential competing moieties (such as two acetate and two benzoate groups) to generate a free 2-hydroxyl group. The newly generated hydroxyl group may be efficiently and quantitatively re-protected with a tetrahydropyran (THP) group to provide a fully protected 2-THP containing pentasaccharide that may be selectively and consequentially O-sulfated, hydrogenated and N-sulfated to produce the desired pentasaccharide, such as Fondaparinux, in excellent yields. The inventors have surprisingly found that the THP group remains intact and protected through all of the subsequent operations and is efficiently removed during work-up, after the final N-sulfonation step.
[0027] The present invention includes certain intermediate compounds identified below, including those of Formula I.
[0028] One embodiment of the invention is a process for making Fonadparinux sodium by converting at least one compound selected from
[0000]
[0000] where R 2 is Ac or Bz,
[0000]
[0000] where R 2 is Ac or Bz,
[0000]
[0000] where R 2 is Ac or Bz,
[0000]
[0000] to Fonadaparinux sodium.
[0029] Yet another embodiment is a method of preparing an oligosaccharide having a β-glucosamine glycosidic linkage by reacting a 1,6-anhydro glucopyranosyl acceptor (e.g., 1,6-anhydro-β-D-glucopyranose) having an azide functional group at C2 and a hydroxyl group at C4 with a uronic acid glycopyranosyl donor having an activated anomeric carbon, a levulinate group at C2, and a protected acid group at C5 to form an oligosaccharide having a β-glycosidic linkage between the hydroxyl group of the glucopyranosyl acceptor and the anomeric carbon of the glycopyranosyl donor.
BRIEF DESCRIPTION OF THE FIGURES
[0030] FIG. 1 depicts the structure of Fondaparinux sodium.
[0031] FIG. 2 depicts the stereochemical relationship between the D-sugar and the C-sugar in Fondaparinux sodium.
[0032] FIG. 3 is a 1 H NMR spectrum of the EDC trimer.
[0033] FIG. 4 is a 1 H NMR spectrum of the EDC-1 trimer.
[0034] FIG. 5 is a 1 H NMR spectrum of the EDC-2 trimer.
[0035] FIG. 6 is a 1 H NMR spectrum of the EDC-3 trimer.
[0036] FIG. 7 is a 1 H NMR spectrum of the EDCBA-1 pentamer.
[0037] FIG. 8 is a 1 H NMR spectrum of the EDCBA-2 pentamer.
[0038] FIG. 9 is a 1 H NMR spectrum of the EDCBA pentamer.
[0039] FIG. 10 is a 1 H NMR spectrum of API-2 pentamer.
[0040] FIG. 11 is a 1 H NMR spectrum of API-3 pentamer.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Applicants have surprisingly found that in the synthesis of Fondaparinux, the use of a unique levulinate-protected 2-glucuronic acid-anhydro sugar coupling methodology allows for an highly efficient glycosylation reaction, thereby providing late stage intermediates or oligosaccharides (and Fondaparinux related oligomers) in high yield and in high β/α ratios. In particular, glycosylation of the 2-levulinate-protected glucuronic acid with an anhydro sugar occurs quickly (for example, with a reaction time of about an hour), with high coupling yields (>65%) of the β-isomer, and with high selectivity (for example, with no detectable α-isomer upon column chromatography purification). The levulinate protecting group may be efficiently and selectively removed from the glycosylated product in the presence of potential competing moieties (such as two acetate and two benzoate groups) to generate a free 2-hydroxyl group. The newly generated hydroxyl group may be efficiently and quantitatively re-protected with a tetrahydropyran (THP) group to provide a fully protected 2-THP containing pentasaccharide that may be selectively and consequentially O-Sulfated, hydrogenated and N-sulfated to produce the desired pentasaccharide, such as Fondaparinux, in excellent yields. The THP group remains intact and protected through all of the subsequent operations and is efficiently removed during work-up, after the final N-sulfonation step.
[0042] The levulinyl group can be rapidly and almost quantitatively removed by treatment with hydrazine hydrate as the deprotection reagent as illustrated in the example below. Under the same reaction conditions primary and secondary acetate and benzoate esters are hardly affected by hydrazine hydrate. See, e.g., Seeberger et al., J. Org. Chem., 69, 4081-4093, 2004.
[0000]
[0043] The syntheses of Fondaparinux sodium described herein takes advantage of the levulinyl group in efficient construction of the trisaccharide EDC with improved β-selectivity for the coupling under milder conditions and increased yields.
[0000]
[0044] Substitution of the benzyl protecting group with a THP moiety provides its enhanced ability to be incorporated quantitatively in position-2 of the unit D of the pentasaccharide. Also, the THP group behaves in a similar manner to a benzyl ether in terms of function and stability. In the processes described herein, the THP group is incorporated at the 2-position of the D unit at this late stage of the synthesis (i.e., after the D and C units have been coupled through a 1,2-trans glycosidic (β-) linkage). The THP protective group typically does not promote an efficient β-glycosylation and therefore is preferably incorporated in the molecule after the construction of the β-linkage.
[0045] The scheme below exemplifies some of the processes of the present invention disclosed herein.
[0000]
[0046] The tetrahydropyranyl (THP) protective group and the benzyl ether protective group are suitable hydroxyl protective groups and can survive the last four synthetic steps (described above) in the synthesis of Fondaparinux sodium, even under harsh reaction conditions. Certain other protecting groups do not survive the last four synthetic steps in high yield.
[0047] Thus, in one aspect, the present invention relates to novel levulinyl and tetrahydropyran pentasaccharides. Such compounds are useful as intermediates in the synthesis of Fondaparinux.
[0048] In one embodiment, the present invention relates to a compound of Formula I:
[0000]
[0000] wherein
[0049] R 1 is levulinyl (Lev) or tetrahydropyran (THP);
[0050] R 2 is —O − or a salt thereof, —OH, —OAcyl, or —OSO 3 − or a salt thereof;
[0051] R 3 is H, benzyl or a protecting group removable by hydrogenation (a hydroxyl protecting group) (for example, —CO 2 − or a salt thereof);
[0052] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0053] R 5 is C 1 -C 6 alkyl; and
[0054] R 6 and R 7 are independently selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe); and wherein said compound has alpha (α) stereochemistry at the carbon bearing the —OR 5 group.
[0055] In one embodiment, R 2 is —O-Acetyl or —O-Benzoyl. In another embodiment, R 2 is —O − , —ONa, —OLi, —OK or —OCs. In a further embodiment, R 2 is —OSO 3 − , —OSO 3 Na, —OSO 3 Li, —OSO 3 K or —OSO 3 Cs.
[0056] In another embodiment, R 5 is methyl.
[0057] In a further embodiment, R 3 is benzyl or p-methoxybenzyl. In yet a further embodiment, R 3 is —CO 2 − , —CO 2 Na, —CO 2 Li, —CO 2 K or —CO 2 Cs.
[0058] In one embodiment of the compound of Formula (I), R 1 is levulinyl (Lev), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me.
[0059] In another embodiment of the compound of Formula (I), R 1 is tetrahydropyran (THP), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me.
[0060] In yet another embodiment of the compound of Formula (I), R 1 is tetrahydropyran (THP), R 2 is —O − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof.
[0061] In a further embodiment of the compound of Formula (I), R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 or a salt thereof.
[0062] In another embodiment of the compound of Formula (I), R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is H, R 4 is NH 2 , R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof.
[0063] In another embodiment of the compound of Formula (I), R 1 is tetrahydropyran (THP), R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na.
[0064] In yet a further embodiment, the present invention relates to a compound of Formula I:
[0000]
[0065] wherein R 1 is H, R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me.
Synthetic Processes
[0066] In another aspect, the present invention relates to processes for the preparation of fondaparinux. The invention also relates to processes for the preparation of novel intermediates useful in the synthesis of fondaparinux. The processes described herein proceed in an efficient manner, thereby providing the desired compounds in good yield and in a manner that is scalable and reproducible on an industrial scale.
Selective Coupling Strategy
[0067] The present invention provides a procedure for the selective formation of a β-anomer product from a glycosylation coupling reaction. Without wishing to be bound by theory, the applicants believe that the β/α ratio observed during the processes described herein is due to the levulinate-directed glycosylation exemplified below:
[0000]
[0068] The 2-levulinate-mediated glycosylation reactions described herein provide a surprisingly high β/α ratio of coupled products. In the present invention, a high β-selectivity is obtained when the present, conformationally restricted, anhydro acceptor C is used. The high β-selectivity is unexpected and may be due the conformationally locked anhydroglucose.
[0069] Thus, in certain aspects, the present invention provides a levulinate ester/tetrandropyranyl ether (Lev/THP) strategy for the protection, deprotection and re-protection of the 2-position of a glucuronic saccharide, which is useful for the synthesis of Fondaparinux and related compounds.
[0070] In one embodiment, the present invention relates to a process for preparing fondaparinux sodium:
[0000]
[0000] In certain embodiments, the process includes (a) at least one of:
[0071] (i) deprotecting and then THP protecting a levulinate pentamer of the formula:
[0000]
[0000] where R 2 is Ac or Bz to obtain a THP pentamer of the formula:
[0000]
[0072] (ii) hydrolyzing a THP pentamer of the formula:
[0000]
[0000] where R 2 is Ac or Bz to obtain a hydrolyzed pentamer of the formula:
[0000]
[0073] (iii) sulfating a hydrolyzed pentamer of the formula:
[0000]
[0000] to obtain an O-sulfated pentamer of the formula:
[0000]
[0074] (iv) hydrogenating an O-sulfated pentamer of the formula:
[0000]
[0000] to obtain a hydrogenated pentamer of the formula:
[0000]
[0000] and
[0075] (vi) N-sulfating a hydrogenated pentamer of the formula:
[0000]
[0000] to obtain Fondaparinux-THP of the formula:
[0000]
[0000] and
(b) optionally, converting the product of step (a) to Fondaparinux sodium. For instance, the Fondaparinux-THP intermediate shown above can be deprotected (i.e., the THP protecting group can be removed) to obtain Fondaparinux.
[0076] In another aspect, the present invention relates to a process for preparing a compound of Formula I:
[0000]
[0077] wherein R 1 is H, R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na, the process including:
[0078] (a) deprotecting a compound of Formula I wherein R 1 is levulinyl (Lev), R 2 is —OAcetyl or —Obenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me, to provide a compound of Formula I wherein R 1 is H, R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me;
[0079] (b) protecting the product of step (a) to provide a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me;
[0080] (c) hydrolyzing the product of step (b) to provide a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —O − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof;
[0081] (d) sulfating the product of step (c) to provide a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof;
[0082] (e) hydrogenating the product of step (d) to provide a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is H, R 4 is NH 2 , R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof;
[0083] (f) sulfating the product of step (e) to provide a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na; and
[0084] (g) deprotecting the product of step (f) to provide a compound of Formula I wherein R 1 is H, R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na.
[0085] In one embodiment, deprotecting step (a) includes treatment with a reagent selected from hydrazine, hydrazine hydrate, hydrazine acetate and R 8 NH—NH 2 where R 8 is aryl, heteroaryl or alkyl.
[0086] In one embodiment, deprotecting step (a) includes treatment with hydrazine
[0087] In another embodiment, protecting step (b) includes treatment with dihyropyran or a dihydropyran derivative and an acid selected from camphor sulfonic acid (CSA), hydrochloric acid (HCl), p-toluenesulfonic acid (pTsOH) and Lewis acids.
[0088] In one embodiment protecting step (b) includes treatment with dihyropyran and an acid selected from hydrochloric acid and p-toluenesulfonic acid.
[0089] In another aspect, the present invention relates to a process for preparing a THP pentamer of the formula:
[0000]
[0000] wherein R 2 is Ac or Bz;
the process including deprotecting and then THP protecting a compound of the formula:
[0000]
[0090] In a further embodiment of this aspect, the process further includes hydrolyzing the THP pentamer to produce a hydrolyzed pentamer of the formula:
[0000]
[0091] In a further embodiment of this aspect, the process further includes sulfating the hydrolyzed pentamer to obtain an O-sulfated pentamer of the formula:
[0000]
[0092] In a further embodiment of this aspect, the process further includes hydrogenating the O-sulfated pentamer to obtain a hydrogenated pentamer of the formula:
[0000]
[0093] In a further embodiment of this aspect, the process further includes N-sulfating the hydrogenated pentamer to obtain fondaparinux-THP of the formula:
[0000]
[0094] In a further embodiment of this aspect, the process further includes converting the Fondaparinux-THP to Fondaparinux sodium. In one embodiment, the conversion includes deprotecting the Fondaparinux-THP.
[0095] In another aspect, the present invention relates to a process for preparing a compound of Formula I:
[0000]
[0096] wherein R 1 is levulinyl (Lev), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me;
[0097] the process including linking a compound of Formula EDC
[0000]
[0000] wherein R 1 is levulinyl (Lev), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide) and R 6 is —CO 2 CH 2 C 6 H 5 ;
[0098] with a compound of Formula BA
[0000]
[0099] wherein R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl and R 7 is —CO 2 Me.
[0100] In one embodiment of this aspect, the process further includes converting the resulting product to fondaparinux sodium.
[0101] In yet another aspect, the present invention relates to a process for preparing a compound of Formula I:
[0000]
[0000] wherein
[0102] R 1 is H, levulinyl (Lev) or tetrahydropyran (THP);
[0103] R 2 is —O − or a salt thereof, —OH, —OAcyl, or —OSO 3 − or a salt thereof;
[0104] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0105] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0106] R 5 is C 1 -C 6 alkyl; and
[0107] R 6 and R 7 are independently selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe); and
[0000] wherein said compound has alpha (cc) stereochemistry at the carbon bearing the —OR 5 group;
said process including linking a compound of Formula II:
[0000]
[0000] wherein,
[0108] R 1 is H, levulinyl (Lev) or tetrahydropyran (THP);
[0109] R 2 is —O − or a salt thereof, —OH, —OAcyl, —OSO 3 − or a salt thereof;
[0110] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0111] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0112] R 6 and R 7 are independently selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe); and
[0113] R 9 is R 1 or R 2 ,
[0000] with a compound of Formula III
[0000]
[0000] wherein
[0114] R 2 is —O − or a salt thereof, —OH, —OAcyl, —OSO 3 − or a salt thereof;
[0115] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0116] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting
[0117] group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0118] R 5 is C 1 -C 6 alkyl.
[0119] In certain embodiments of this aspect, the compound of Formula II is
[0000]
[0120] and the compound of Formula III is
[0000]
[0121] In yet another aspect, the present invention relates to a process for preparing a compound of Formula I:
[0000]
[0000] wherein,
[0122] R 1 is H, levulinyl (Lev) or tetrahydropyran (THP);
[0123] R 2 is —O − or a salt thereof, —OH, —OAcyl, or —OSO 3 − or a salt thereof;
[0124] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0125] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0126] R 5 is C 1 -C 6 alkyl; and
[0127] R 6 and R 7 are independently selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe); and
[0000] wherein said compound has alpha (α) stereochemistry at the carbon bearing the —OR 5 group;
the process including linking a compound of Formula IV:
[0000]
[0000] wherein,
[0128] R 1 is H, levulinyl (Lev) or tetrahydropyran (THP);
[0129] R 2 is —O − or a salt thereof, —OH, —OAcyl, —OSO 3 − or a salt thereof;
[0130] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0131] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 ); and
[0132] R 6 is selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe),
[0000] with a compound of Formula V:
[0000]
[0000] wherein,
[0133] R 1 is H, levulinyl (Lev) or tetrahydropyran (THP);
[0134] R 2 is —O − or a salt thereof, —OH, —OAcyl, —OSO 3 − or a salt thereof;
[0135] R 3 is H, benzyl or a protecting group removable by hydrogenation;
[0136] R 4 is N 3 (azide), NH 2 , NH-protecting group (i.e., —NH—R where R is an amino protecting group), or NHSO 3 − or a salt thereof (e.g., NHSO 3 Na, NHSO 3 Li, NHSO 3 K, and NHSO 3 NH 4 );
[0137] R 5 is C 1 -C 6 alkyl; and
[0138] R 7 is selected from —CO 2 − or a salt thereof, —CO 2 H, and —CO 2 R x (where R x is a C 1 -C 6 alkyl, aryl, C 1 -C 4 alkoxy(aryl), aryl(C 1 -C 6 alkyl), or C 1 -C 4 alkoxy(aryl)(C 1 -C 6 alkyl)) (e.g., —CO 2 Me, —CO 2 CH 2 C 6 H 5 and —CO 2 CH 2 C 6 H 4 OMe); and
[0139] R 9 is R 1 or R 2 .
[0140] In certain embodiments of this aspect, the compound of Formula IV is
[0000]
[0141] and the compound of Formula V is
[0000]
[0142] In another aspect, the present invention relates to a process for preparing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me, the process including:
[0143] (a) deprotecting a compound of Formula I wherein R 1 is levulinyl (Lev), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 and R 7 is —CO 2 Me to afford a compound of Formula I wherein R 1 is H, R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 , and R 7 is —CO 2 Me; and
[0144] (b) THP protecting the product of step (a).
[0145] In one embodiment, deprotecting step (a) includes treatment with a reagent selected from hydrazine, hydrazine hydrate, hydrazine acetate and R 8 NH—NH 2 where R 8 is aryl, heteroaryl or alkyl. In one embodiment deprotecting step (a) comprises treatment with hydrazine.
[0146] In one embodiment, protecting step (b) comprises treatment with dihyropyran or a dihydropyran derivative and an acid selected from camphor sulfonic acid (CSA), hydrochloric acid (HCl), p-toluenesulfonic acid (pTsOH) and Lewis acids. In one embodiment, protecting step (b) comprises treatment with dihyropyran and an acid selected from hydrochloric acid and p-toluenesulfonic acid.
[0147] In another aspect, the present invention relates to a process for preparing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —O − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof, comprising hydrolyzing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OAcetyl or —OBenzoyl, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, R 6 is —CO 2 CH 2 C 6 H 5 , and R 7 is —CO 2 Me.
[0148] In another aspect, the present invention relates to a process for preparing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof, comprising sulfating a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —O − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof.
[0149] In another aspect, the present invention relates to a process for preparing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is H, R 4 is NH 2 , R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof, comprising the step of hydrogenating a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is benzyl, R 4 is N 3 (azide), R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof.
[0150] In another aspect, the present invention relates to a process for preparing a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na, comprising the step of sulfating a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 − or a salt thereof, R 3 is H, R 4 is NH 2 , R 5 is methyl, and R 6 and R 7 are —CO 2 − or a salt thereof.
[0151] In a further aspect, the present invention relates to a process for making a compound of Formula I:
[0000]
[0152] wherein R 1 is H, R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na;
[0153] the process including deprotecting a compound of Formula I wherein R 1 is tetrahydropyran (THP), R 2 is —OSO 3 Na, R 3 is H, R 4 is NHSO 3 Na, R 5 is methyl, and R 6 and R 7 are —CO 2 Na.
[0154] In yet a further aspect, the present invention relates to a process for making a compound of Formula 8:
[0000]
[0000] comprising reacting a compound of Formula 9:
[0000]
[0000] with a compound of Formula 10:
[0000]
Fondaparinux Sodium
[0155] In a further aspect, the present invention relates to Fondaparinux, or a salt thereof (e.g., Fondaparinux sodium) containing a compound selected from P2, P3, P4, and combinations thereof.
[0000] Compound P2 (methylated nitrogen on the E ring):
[0000]
[0000] Compound P3 (methylated nitrogen on the A ring):
[0000]
[0000] Compound P4 (N-formyl group on the C ring):
[0000]
[0156] In additional embodiments, the present invention relates to a composition (such as a pharmaceutical composition) that includes Fondaparinux, or a salt thereof (e.g., Fondaparinux sodium) and a compound selected from P2, P3, P4, and combinations thereof.
[0157] In certain embodiments, the Fondaparinux, or a salt thereof (e.g., Fondaparinux sodium), or composition contains at least 90, 95, 98, 99 or 99.5% Fondaparinux, or salt thereof, based on the total weight of Fondaparinux or composition.
[0158] In certain embodiments, Compound P2 is present in an amount of greater than 0% and less than about 0.5%, such as greater than 0% and less than about 0.4%, greater than 0% and less than about 0.3%, greater than 0% and less than about 0.2% and greater than 0% and less than about 0.1%, based on the total weight of Fondaparinux or composition.
[0159] In certain embodiments, Compound P3 is present in an amount of greater than 0% and less than about 0.5%, such as greater than 0% and less than about 0.4%, greater than 0% and less than about 0.3%, greater than 0% and less than about 0.2% and greater than 0% and less than about 0.1%, based on the total weight of Fondaparinux or composition.
[0160] In certain embodiments, Compound P4 is present in an amount of greater than 0% and less than about 0.5%, such as greater than 0% and less than about 0.4%, greater than 0% and less than about 0.3%, greater than 0% and less than about 0.2% and greater than 0% and less than about 0.1%, based on the total weight of Fondaparinux or composition.
[0161] In additional embodiments, the Fondaparinux, or a salt thereof (e.g., Fondaparinux sodium) (or composition that includes Fondaparinux, or a salt thereof (e.g., Fondaparinux sodium)) may also contain Compound P1 (in addition to containing a compound selected from P2, P3, P4, and combinations thereof).
[0000] Compound P1 (beta-anomer of Fondaparinux sodium)
[0000]
[0162] In certain embodiments, Compound P1 is present in an amount of greater than 0% and less than about 0.5%, such as greater than 0% and less than about 0.4%, greater than 0% and less than about 0.3%, greater than 0% and less than about 0.2% and greater than 0% and less than about 0.1%, based on the total weight of Fondaparinux or composition.
[0163] In additional embodiments, the present invention relates to a composition (such as a pharmaceutical composition) that includes Fondaparinux or a salt thereof (e.g., Fondaparinux sodium) and one or more tetrahydropyran protected pentasaccharides. In additional embodiments, the tetrahydropyran protected pentasaccharide is any of the tetrahydropyran protected pentasaccharides as described in any of the embodiments herein.
[0164] In certain embodiments, the tetrahydropyran protected pentasaccharide is present in an amount of greater than 0% and less than about 0.5%, such as greater than 0% and less than about 0.4%, greater than 0% and less than about 0.3%, greater than 0% and less than about 0.2%, greater than 0% and less than about 0.1%, based on the total weight of Fondaparinux or composition.
[0165] Any of the aforementioned forms of Fondaparinux (or a salt thereof) or compositions containing Fondaparinux (or a salt thereof) may be administered (e.g., 2.5 mg, 5 mg, 7.5 mg, 10 mg, solution for injection) for the prophylaxis of deep vein thrombosis (DVT) which may lead to pulmonary embolism (PE) in patients undergoing (i) hip fracture surgery (including extended prophylaxis), (ii) hip replacement surgery, (iii) knee replacement surgery and (iv) abdominal surgery (who are at risk for thromboembolic complications). The forms and compositions described herein may also be administered in conjunction with wafarin sodium for the treatment of acute DVT and PE.
DEFINITIONS
[0166] Examples of alkyl groups having one to six carbon atoms, are methyl, ethyl, propyl, butyl, pentyl, hexyl, and all isomeric forms and straight and branched thereof.
[0167] The term “acyl” unless otherwise defined refers to the chemical group —C(O)R. R can be, for example, aryl (e.g., phenyl) or alkyl (e.g., C 1 -C 6 alkyl).
[0168] The term “aryl” refers to an aromatic group having 6 to 14 carbon atoms such as, for example, phenyl, naphthyl, tetrahydronapthyl, indanyl, and biphenyl. The term “heteroaryl” refers to an aromatic group having 5 to 14 atoms where at least one of the carbons has been replaced by N, O or S. Suitable examples include, for example, pyridyl, quinolinyl, dihydroquinolinyl, isoquinolinyl, quinazolinyl, dihydroquinazolyl, and tetrahydroquinazolyl.
[0169] It will be apparent to those skilled in the art that sensitive functional groups may need to be protected and deprotected during synthesis of a compound of the invention. This may be achieved by conventional methods, for example as described in “Protective Groups in Organic Synthesis” by Greene and Wuts, John Wiley & Sons Inc (1999), and references therein which can be added or removed using the procedures set forth therein. Examples of protected hydroxyl groups (i.e., hydroxyl protecting groups) include silyl ethers such as those obtained by reaction of a hydroxyl group with a reagent such as, but not limited to, t-butyldimethyl-chlorosilane, trimethylchlorosilane, triisopropylchlorosilane, triethylchlorosilane; substituted methyl and ethyl ethers such as, but not limited to, methoxymethyl ether, methythiomethyl ether, benzyloxymethyl ether, t-butoxymethyl ether, 2-methoxyethoxymethyl ether, tetrahydropyranyl ethers, 1-ethoxyethyl ether, allyl ether, benzyl ether; esters such as, but not limited to, benzoylformate, formate, acetate, trichloroacetate, and trifluoracetate. Examples of protected amine groups (i.e., amino protecting groups) include, but are not limited to, amides such as, formamide, acetamide, trifluoroacetamide, and benzamide; imides, such as phthalimide, and dithiosuccinimide; and others. Examples of protected sulfhydryl groups include, but are not limited to, thioethers such as S-benzyl thioether, and S-4-picolyl thioether; substituted S-methyl derivatives such as hemithio, dithio and aminothio acetals; and the like.
[0170] A protecting group that can be removed by hydrogenation is, by way of example, benzyl or a substituted benzyl group, for example benzyl ethers, benzylidene acetals. While the benzyl group itself is a commonly used protecting group that can be removed by hydrogenation, one example of a substituted benzyl protecting group is p-methoxy benzyl.
[0171] A number of hydrazine and hydrazine derivative are available for the deprotection (removal) of tetrahydropyran (THP) protecting group, including, but not limited to, hydrazine [NH 2 —NH 2 ], hydrazine hydrate [NH 2 —NH 2 .H 2 O] and hydrazine acetate [NH 2 —NH 2 .AcOH] and alkyl and aryl hydrazine derivatives such as R 8 NH—NH 2 where R 8 is aryl, heteroaryl or alkyl.
[0172] Lewis acids known in the art include, for example, magnesium chloride, aluminum chloride, zinc chloride, boron trifluoride dimethyl etherate, titanium(IV) chloride and ferric chloride.
[0173] Throughout the description and claims of this specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps.
[0174] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component” includes mixtures of two or more components.
[0175] Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.
[0176] Throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon.
[0177] The following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention in any way as many variations and equivalents that are encompassed by the present invention will become apparent to those skilled in the art upon reading the present disclosure.
Examples
[0178] In the synthesis of Fondaparinux sodium, the monomers A2, B1, C, D and E described herein may be made either by processes described in the art or, e.g., in the case of the D monomer, by a process as described herein. The B1 and A2 monomers may then linked to form a disaccharide, BA dimer. The E, D and C monomers may be linked to form a trisaccharide, EDC trimer. The EDC trimer may be derivatized to form an intermediate suitable for coupling with the BA dimer, thereby forming a pentasaccharides (EDCBA) pentamer. The EDCBA pentamer is an intermediate that may be converted through a series of reactions to Fondaparinux sodium. This strategy described herein provides an efficient method for multi kilograms preparation of Fondaparinux in high yields and high stereoselectivity.
Synthetic Procedures
[0179] The following abbreviations are used herein: Ac is acetyl; ACN is acetonitrile; MS is molecular sieves; DMF is dimethyl formamide; PMB is p-methoxybenzyl; Bn is benzyl; DCM is dichloromethane; THF is tetrahydrofuran; TFA is trifluoro acetic acid; CSA is camphor sulfonic acid; TEA is triethylamine; MeOH is methanol; DMAP is dimethylaminopyridine; RT is room temperature; CAN is ceric ammonium nitrate; Ac 2 O is acetic anhydride; HBr is hydrogen bromide; TEMPO is tetramethylpiperidine-N-oxide; TBACl is tetrabutyl ammonium chloride; EtOAc is ethyl acetate; HOBT is hydroxybenzotriazole; DCC is dicyclohexylcarbodiimide; Lev is levunlinyl; TBDPS is tertiary-butyl diphenylsilyl; TCA is trichloroacetonitrile; O-TCA is O-trichloroacetimidate; Lev 2 O is levulinic anhydride; DIPEA is diisopropylethylamine; Bz is benzoyl; TBAF is tetrabutylammonium fluoride; DBU is diazabicycloundecane; BF 3 .Et 2 O is boron trifluoride etherate; TMSI is trimethylsilyl iodide; TBAI is tetrabutylammonium iodide; TES-Tf is triethylsilyl trifluoromethanesulfonate (triethylsilyl triflate); DHP is dihydropyran; PTS is p-toluenesulfonic acid.
[0180] The monomers used in the processes described herein may be prepared as described in the art, or can be prepared using the methods described herein.
Monomer A-2
[0181]
[0182] The synthesis of Monomer A-2 (CAS Registry Number 134221-42-4) has been described in the following references: Arndt et al., Organic Letters, 5(22), 4179-4182, 2003; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; and Sakairi et al., Journal of the Chemical Society, Chemical Communications , (5), 289-90, 1991, and the references cited therein, which are hereby incorporated by reference in their entireties.
Monomer C
[0183]
[0184] Monomer C (CAS Registry Number 87326-68-9) can be synthesized using the methods described in the following references: Ganguli et al., Tetrahedron: Asymmetry, 16(2), 411-424, 2005; Izumi et al., Journal of Organic Chemistry, 62(4), 992-998, 1997; Van Boeckel et al., Recueil: Journal of the Royal Netherlands Chemical Society, 102(9), 415-16, 1983; Wessel et al., Helvetica Chimica Acta, 72(6), 1268-77, 1989; Petitou et al., U.S. Pat. No. 4,818,816 and references cited therein, which are hereby incorporated by reference in their entireties.
Monomer E
[0185]
[0186] Monomer E (CAS Registry Number 55682-48-9) can be synthesized using the methods described in the following literature references: Hawley et al., European Journal of Organic Chemistry , (12), 1925-1936, 2002; Dondoni et al., Journal of Organic Chemistry, 67(13), 4475-4486, 2002; Van der Klein et al., Tetrahedron, 48(22), 4649-58, 1992; Hori et al., Journal of Organic Chemistry, 54(6), 1346-53, 1989; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; Tailler et al., Journal of the Chemical Society, Perkin Transactions 1 : Organic and Bio - Organic Chemistry , (23), 3163-4, (1972-1999) (1992); Paulsen et al., Chemische Berichte, 111(6), 2334-47, 1978; Dasgupta et al., Synthesis , (8), 626-8, 1988; Paulsen et al., Angewandte Chemie, 87(15), 547-8, 1975; and references cited therein, which are hereby incorporated by reference in their entireties.
Monomer B-1
[0187]
[0188] Monomer B-1 (CAS Registry Number 444118-44-9) can be synthesized using the methods described in the following literature references: Lohman et al., Journal of Organic Chemistry, 68(19), 7559-7561, 2003; Orgueira et al., Chemistry—A European Journal, 9(1), 140-169, 2003; Manabe et al., Journal of the American Chemical Society, 128(33), 10666-10667, 2006; Orgueira et al., Angewandte Chemie, International Edition, 41(12), 2128-2131, 2002; and references cited therein, which are hereby incorporated by reference in their entireties.
Synthesis of Monomer D
[0189] Monomer D was prepared in 8 synthetic steps from glucose pentaacetate using the following procedure:
[0000]
[0190] Pentaacetate SM-B was brominated at the anomeric carbon using HBr in acetic acid to give bromide derivative IntD1. This step was carried out using the reactants SM-B, 33% hydrogen bromide, acetic acid and dichloromethane, stirring in an ice water bath for about 3 hours and evaporating at room temperature. IntD1 was reductively cyclized with sodium borohydride and tetrabutylammonium iodide in acetonitrile using 3 Å molecular sieves as dehydrating agent and stirring at 40° C. for 16 hours to give the acetal derivative, IntD2. The three acetyl groups in IntD2 were hydrolyzed by heating with sodium methoxide in methanol at 50° C. for 3 hours and the reaction mixture was neutralized using Dowex 50WX8-100 resin (Aldrich) in the acid form to give the trihydroxy acetal derivative IntD3.
[0191] The C4 and C6 hydroxyls of IntD3 were protected by mixing with benzaldehyde dimethyl acetate and camphor sulphonic acid at 50° C. for 2 hours to give the benzylidene-acetal derivative IntD4. The free hydroxyl at the C3 position of IntD4 was deprotonated with sodium hydride in THF as solvent at 0° C. and alkylated with benzyl bromide in THF, and allowing the reaction mixture to warm to room temperature with stirring to give the benzyl ether IntD5. The benzylidene moiety of IntD5 was deprotected by adding trifluoroacetic acid in dichloromethane at 0° C. and allowing it to warm to room temperature for 16 hours to give IntD6 with a primary hydroxyl group. IntD6 was then oxidized with TEMPO (2,2,6,6-tetramethyl-1-piperdine-N-oxide) in the presence of tetrabutylammonium chloride, sodium bromide, ethyl acetate, sodium chlorate and sodium bicarbonate, with stirring at room temperature for 16 hours to form the carboxylic acid derivative IntD7. The acid IntD7 was esterified with benzyl alcohol and dicyclohexylcarbodiimide (other reactants being hydroxybenzotriazole and triethylamine) with stirring at room temperature for 16 hours to give Monomer D.
Synthesis of the BA Dimer
[0192] The BA Dimer was prepared in 12 synthetic steps from Monomer B1 and Monomer A2 using the following procedure:
[0000]
[0193] The C4-hydroxyl of Monomer B-1 was levulinated using levulinic anhydride and diisopropylethylamine (DIPEA) with mixing at room temperature for 16 hours to give the levulinate ester BMod1, which was followed by hydrolysis of the acetonide with 90% trifluoroacetic acid and mixing at room temperature for 4 hours to give the diol BMod2. The C1 hydroxyl of the diol BMod2 was silylated with tert-butyldiphenylsilylchloride by mixing at room temperature for 3 hours to give silyl derivative BMod3. The C2-hydroxyl was then benzoylated with benzoyl chloride in pyridine, and mixed at room temperature for 3 hours to give compound BMod4. The silyl group on BMod4 was then deprotected with tert-butyl ammonium fluoride and mixing at room temperature for 3 hours to give the C1-hydroyl BMod5. The C1-hydroxyl is then allowed to react with trichloroacetonitrile in the presence of diazobicycloundecane (DBU) and mixing at room temperature for 2 hours to give the trichloroacetamidate (TCA) derivative BMod6, which suitable for coupling, for example with Monomer A-2.
[0194] Monomer A-2 was prepared for coupling by opening the anhydro moiety with BF 3 .Et 2 O followed by acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1.
[0195] Monomer A2 was prepared for the coupling reaction by opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1. This transformation occurs using boron trifluoride etherate, acetic anhydride and dichloromethane, between −20° C. and room temperature for 3 hours. The C1-Acetate of AMod1 was then hydrolyzed and methylated in two steps to give the diacetate AMod3. That is, first AMod1 was reacted with trimethylsilyl iodide and mixed at room temperature for 2 hours, then reacted with and tetrabutyl ammonium iodide. This mixture was reacted with diisoproylethylamine and methanol and stirred for 16 hours at room temperature, thus forming AMod3. The C4 and C6 acetates of AMod3 are hydrolyzed with sodium methoxide to give the diol Amod4. The AMod3 mixture was also subjected to mixing at room temperature for 3 hours with Dowex 50 Wx4X8-100 resin in the acid form for neutralization. This formed Amod4. The C6-hydroxyl of AMod4 is then benzoylated by treating with benzoyl chloride in pyridine at −40° C. and then allowing it to warm up to −10° C. over 2 hours to give AMod5.
[0196] Coupling of monomer AMod5 with the free C4-hydroxyl group of BMod6 was performed in the presence of BF 3 .Et 2 O and dichloromethane with mixing between −20° C. and room temperature for 3 hours to provide disaccharide BA1. The C4-levulinyl moiety of the disaccharide was then hydrolyzed with hydrazine to give the BA Dimer, which is suitable for subsequent coupling reactions.
Synthesis of EDC Trimer
[0197] The EDC Trimer was prepared in 10 synthetic steps from Monomer E, Monomer D and Monomer C using the following procedure:
[0000]
[0198] Monomer E was prepared for coupling by opening the anhydro moiety with BF 3 .Et 2 O followed by acetylation of the resulting hydroxyl groups to give diacetate EMod1. This occurs by the addition of Monomer E with boron trifluoride etherate, acetic anhydride and dichloromethane at −10° C., and allowing the reaction to warm to room temperature with stirring for 3 hours. The C1-Acetate of EMod1 is then hydrolyzed to give the alcohol, EMod2. This occurs by reacting Emod1 with hydrazine acetate and dimethylformamide and mixing at room temperature for 3 hours. The C1-hydroxyl of Emod2 is then reacted with trichloroacetonitrile to give the trichloro acetamidate (TCA) derivative EMod3 suitable for coupling, which reaction also employs diazabicycloundecane and dichloromethane and mixing at room temperature for 2 hours.
[0199] Monomer D, having a free C4-hydroxyl group, was coupled with monomer EMod3 in the presence of triethylsilyl triflate with mixing at −40° C. for 2 hours to give the disaccharide ED Dimer. The acetal on ring sugar D of the ED Dimer is hydrolyzed to give the C1,C2-diol ED1. This occurs by reacting the ED Dimer with 90% trifluoro acetic acid and mixing at room temperature for 4 hours. The C1-hydroxyl moiety of ED1 was then silylated with tert-butyldiphenylsilyl chloride to give the silyl derivative ED2. The C2-hydroxyl of ED2 was then allowed to react with levulinic anhydride in the presence of dimethylaminopyridine (DMAP) and diethylisopropylamine for approximately 16 hours to give the levulinate ester ED3. The TBDPS moiety is then deprotected by removal with tert-butylammonium fluoride in acetic acid with mixing at room temperature for 3 hours to give ED4 having a C1-hydroxyl. The C1-hydroxyl moiety of ED4 was then allowed to react with trichloroacetonitrile to give the TCA derivative ED5, which is suitable for coupling.
[0200] The C1-hydroxyl moiety of ED4 is then allowed to react with trichloroacetonitrile to give the TCA derivative ED5 suitable for coupling using diazabicycloundecane and dichloromethane, and mixing at room temperature for 2 hours. Monomer C, having a free C4-hydroxyl group, was then coupled with the disaccharide ED5 in the presence of triethylsilyl triflate and mixed at −20° C. for 2 hours to give the trisaccharide EDC Trimer.
Synthesis of the EDCBA Pentamer
[0201] The EDCBA Pentamer was prepared using the following procedure:
[0000]
[0202] The preparation of EDCBA Pentamer is accomplished in two parts as follows. In part 1, the EDC Trimer, a diacetate intermediate, is prepared for the coupling reaction with Dimer BA by initially opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the tetraacetate derivative EDC1. This occurs by reacting the EDC Trimer with boron trifluoride etherate, acetic anhydride and dichlormethane and stirring between −10° C. and room temperature for 3 hours. The C1-Acetate of EDC1 is then hydrolyzed to give the alcohol, EDC2, by reacting EDC1 with benzylamine [BnNH 2 ] and tetrahydrofuran and mixing at −10° C. for 3 hours. The C1-hydroxyl of EDC2 is then reacted with trichloroacetonitrile and diazabicycloundecane, with mixing at room temperature for 2 hours, to give the trichloro acetamidate (TCA) derivative EDC3 suitable for coupling.
[0000]
[0203] In Part 2 of the EDCBA Pentameter synthesis, the Dimer BA, having a free C4-hydroxyl group, is coupled with trisaccharide EDC3 in the presence of trimethylsilyltriflate at −30° C. mixing for 2 hours to give the pentasaccharide EDCBA1. The levulinyl ester on C2 of sugar D in EDCBA1 is hydrolyzed with a mixture of deprotecting agents, hydrazine hydrate and hydrazine acetate and stirring at room temperature for 3 hours to give the C2-hydroxyl containing intermediate EDCBA2. The C2-hydroxyl moiety on sugar D of EDCBA2 is then alkylated with dihydropyran (DHP) in the presence of camphor sulfonic acid (CSA) and tetrahydrofuran with mixing at room temperature for 3 hours to give the tetrahydropyranyl ether (THP) derivative, EDCBA Pentamer.
Synthesis of Fondaparinux
[0204] Fondaparinux was prepared using the following procedure:
[0000]
[0205] The ester moieties in EDCBA Pentamer were hydrolyzed with sodium and lithium hydroxide in the presence of hydrogen peroxide in dioxane mixing at room temperature for 16 hours to give the pentasaccharide intermediate API1. The five hydroxyl moieties in API1 were sulfated using a pyridine-sulfur trioxide complex in dimethylformamide, mixing at 60° C. for 2 hours and then purified using column chromatography (CG-161), to give the pentasulfated pentasaccharide API2. The intermediate API2 was then hydrogenated to reduce the three azides on sugars E, C and A to amines and the reductive deprotection of the five benzyl ethers to their corresponding hydroxyl groups to form the intermediate API3. This transformation occurs by reacting API2 with 10% palladium/carbon catalyst with hydrogen gas for 72 hours. The three amines on API3 were then sulfated using the pyridine-sulfur trioxide complex in sodium hydroxide and ammonium acetate, allowing the reaction to proceed for 12 hours. The acidic work-up procedure of the reaction removes the THP group to provide crude fondaparinux which is purified and is subsequently converted to its salt form. The crude mixture was purified using an ion-exchange chromatographic column (HiQ resin) followed by desalting using a size exclusion resin or gel filtration (Biorad Sephadex G25) to give the final API, fondaparinux sodium
Experimental Procedures
Preparation of IntD1
Bromination of Glucose Pentaacetate
[0206] To a 500 ml flask was added 50 g of glucose pentaacetate (C 6 H 22 O 11 ) and 80 ml of methylene chloride. The mixture was stirred at ice-water bath for 20 min HBr in HOAc (33%, 50 ml) was added to the reaction mixture. After stirring for 2.5 hr another 5 ml of HBr was added to the mixture. After another 30 min, the mixture was added 600 ml of methylene chloride. The organic mixture was washed with cold water (200 ml×2), Saturated NaHCO 3 (200 ml×2), water (200 ml) and brine (200 ml×2). The organic layer was dried over Na 2 SO 4 and the mixture was evaporated at RT to give white solid as final product, bromide derivative, IntD1 (˜95% yield). C 14 H 19 BrO 9 , TLC R f =0.49, SiO 2 , 40% ethyl acetate/60% hexanes; Exact Mass 410.02.
Preparation of IntD2 by Reductive Cyclization
[0207] To a stiffing mixture of bromide IntD1 (105 g), tetrabutylammonium iodide (60 g, 162 mmol) and activated 3 Å molecular sieves in anhydrous acetonitrile (2 L), solid NaBH 4 (30 g, 793 mmol) was added. The reaction was heated at 40° C. overnight. The mixture was then diluted with dichloromethane (2 L) and filtered through Celite®. After evaporation, the residue was dissolved in 500 ml ethyl acetate. The white solid (Bu 4 NI or Bu 4 NBr) was filtered. The ethyl acetate solution was evaporated and purified by chromatography on silica gel using ethyl acetate and hexane as eluent to give the acetal-triacetate IntD2 (˜60-70% yield). TLC R f =0.36, SiO 2 in 40% ethyl acetate/60% hexanes.
Preparation of IntD3 by De-Acetylation
[0208] To a 1000 ml flask was added triacetate IntD2 (55 g) and 500 ml of methanol. After stirring 30 min, the reagent NaOMe (2.7 g, 0.3 eq) was added and the reaction was stirred overnight. Additional NaOMe (0.9 g) was added to the reaction mixture and heated to 50° C. for 3 hr. The mixture was neutralized with Dowex 50W×8 cation resin, filtered and evaporated. The residue was purified by silica gel column to give 24 g of trihydroxy-acetal IntD3. TLC R f =0.36 in SiO 2 , 10% methanol/90% ethyl acetate.
Preparation of IntD4 by Benzylidene Formation
[0209] To a 1000 ml flask was added trihydroxy compound IntD3 (76 g) and benzaldehyde dimethyl acetate (73 g, 1.3 eq). The mixture was stirred for 10 min, after which D(+)-camphorsulfonic acid (8.5 g, CSA) was added. The mixture was heated at 50° C. for two hours. The reaction mixture was then transferred to separatory funnel containing ethyl acetate (1.8 L) and sodium bicarbonate solution (600 ml). After separation, the organic layer was washed with a second sodium bicarbonate solution (300 ml) and brine (800 ml). The two sodium carbonate solutions were combined and extracted with ethyl acetate (600 ml×2). The organic mixture was evaporated and purified by silica gel column to give the benzylidene product IntD4 (77 g, 71% yield). TLC R f =0.47, SiO 2 in 40% ethyl acetate/60% hexanes.
Preparation of IntD5 by Benzylation
[0210] To a 500 ml flask was added benzylidene acetal compound IntD4 (21 g,) in 70 ml THF. To another flask (1000 ml) was added NaH (2 eq). The solution of IntD4 was then transferred to the NaH solution at 0° C. The reaction mixture was stirred for 30 min, then benzyl bromide (16.1 ml, 1.9 eq) in 30 ml THF was added. After stirring for 30 min, DMF (90 ml) was added to the reaction mixture. Excess NaH was neutralized by careful addition of acetic acid (8 ml). The mixture was evaporated and purified by silica gel column to give the benzyl derivative IntD5. (23 g) TLC R f =0.69, SiO 2 in 40% ethyl acetate/60% hexanes.
Preparation of IntD6 by Deprotection of Benzylidene
[0211] To a 500 ml flask was added the benzylidene-acetal compound IntD5 (20 g) and 250 ml of dichloromethane, the reaction mixture was cooled to 0° C. using an ice-water-salt bath. Aqueous TFA (80%, 34 ml) was added to the mixture and stirred over night. The mixture was evaporated and purified by silica gel column to give the dihydroxy derivative IntD6. (8 g, 52%). TLC R f =0.79, SiO 2 in 10% methanol/90% ethyl acetate.
Preparation of IntD7 by Oxidation of 6-Hydroxyl
[0212] To a 5 L flask was added dihydroxy compound IntD6 (60 g), TEMPO (1.08 g), sodium bromide (4.2 g), tetrabutylammonium chloride (5.35 g), saturated NaHCO 3 (794 ml) and EtOAc (1338 ml). The mixture was stirred over an ice-water bath for 30 min To another flask was added a solution of NaOCl (677 ml), saturated NaHCO 3 (485 ml) and brine (794 ml). The second mixture was added slowly to the first mixture (over about two hrs). The resulting mixture was then stirred overnight. The mixture was separated, and the inorganic layer was extracted with EtOAc (800 ml×2). The combined organic layers were washed with brine (800 ml). Evaporation of the organic layer gave 64 g crude carboxylic acid product IntD7 which was used in the next step use without purification. TLC R f =0.04, SiO 2 in 10% methanol/90% ethyl acetate.
Preparation of Monomer D by Benzylation of the Carboxylic Acid
[0213] To a solution of carboxylic acid derivative IntD7 (64 g) in 600 ml of dichloromethane, was added benzyl alcohol (30 g) and N-hydroxybenzotriazole (80 g, HOBt). After stirring for 10 min triethylamine (60.2 g) was added slowly. After stiffing another 10 min, dicyclohexylcarbodiimide, (60.8 g, DCC) was added slowly and the mixture was stirred overnight. The reaction mixture was filtered and the solvent was removed under reduced pressure followed by chromatography on silica gel to provide 60.8 g (75%, over two steps) of product, Monomer D. TLC R f =0.51, SiO 2 in 40% ethyl acetate/60% hexanes.
Synthesis of the BA Dimer
Step 1. Preparation of BMod1, Levulination of Monomer B1
[0214] A 100 L reactor was charged with 7.207 Kg of Monomer B1 (21.3 moles, 1 equiv), 20 L of dry tetrahydrofuran (THF) and agitated to dissolve. When clear, it was purged with nitrogen and 260 g of dimethylamino pyridine (DMAP, 2.13 moles, 0.1 equiv) and 11.05 L of diisopropylethylamine (DIPEA, 8.275 kg, 63.9 moles, 3 equiv) was charged into the reactor. The reactor was chilled to 10-15° C. and 13.7 kg levulinic anhydride (63.9 mol, 3 equiv) was transferred into the reactor. When the addition was complete, the reaction was warmed to ambient temperature and stirred overnight or 12-16 hours. Completeness of the reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. When the reaction was complete, 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. The mixture was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L of water, 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight. The yield of the isolated syrup of BMod1 was 100%.
Synthesis of the BA Dimer
Step 2. Preparation of BMod2, TFA Hydrolysis of BMod1
[0215] A 100 L reactor was charged with 9296 Kg of 4-Lev Monomer B1 (BMod1) (21.3 mol, 1 equiv). The reactor chiller was turned to <5° C. and stirring was begun, after which 17.6 L of 90% TFA solution (TFA, 213 mole, 10 equiv) was transferred into the reactor. When the addition was complete, the reaction was monitored by TLC and HPLC. The reaction took approximately 2-3 hours to reach completion. When the reaction was complete, the reactor was chilled and 26.72 L of triethylamine (TEA, 19.4 Kg, 191.7 mole, 0.9 equiv) was transferred into the reactor. An additional 20 L of water and 20 L ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer was extracted (EtOAc layer) with 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 50:50, 80:20 (EtOAc/heptane), 100% EtOAc, 5:95, 10:90 (MeOH/EtOAc). The pure fractions were pooled and evaporated to a syrup. The yield of the isolated syrup, BMod2 was 90%.
Synthesis of the BA Dimer
Step 3. Preparation of BMod3, Silylation of BMod2
[0216] A 100 L reactor was charged with 6.755 Kg 4-Lev-1,2-DiOH Monomer B1 (BMod2) (17.04 mol, 1 equiv), 2328 g of imidazole (34.2 mol, 2 equiv) and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., then 5.22 L tert-butyldiphenylchloro-silane (TBDPS-Cl, 5.607 Kg, 20.4 mol, 1.2 equiv) was transferred into the reactor. When addition was complete, the chiller was turned off and the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (40% ethyl acetate/hexane) and HPLC. The reaction took approximately 3 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. Dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The yield of BMod3 was about 80%.
Synthesis of the BA Dimer
Step 4. Preparation of BMod4, Benzoylation
[0217] A 100 L reactor was charged with 8.113 Kg of 4-Lev-1-Si-2-OH Monomer B1 (BMod3) (12.78 mol, 1 equiv), 9 L of pyridine and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., after which 1.78 L of benzoyl chloride (2155 g, 15.34 mol, 1.2 equiv) was transferred into the reactor. When addition was complete, the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (40% ethyl acetate/heptane) and HPLC. The reaction took approximately 3 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The DCM solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). Isolated syrup BMod4 was obtained in 91% yield.
Synthesis of the BA Dimer
Step 5. Preparation of BMod5, Desilylation
[0218] A 100 L reactor was charged with 8.601 Kg of 4-Lev-1-Si-2-Bz Monomer B1 (BMod4) (11.64 mol, 1 equiv) in 30 L tetrahydrofuran. The reactor was purged with nitrogen and chilled to 0° C., after which 5.49 Kg of tetrabutylammonium fluoride (TBAF, 17.4 mol, 1.5 equiv) and 996 mL (1045 g, 17.4 mol, 1.5 equiv) of glacial acetic acid were transferred into the reactor. When the addition was complete, the reaction was stirred at ambient temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. The reaction took approximately 6 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20 (EtOAc/heptane) and 200 L 100% EtOAc. Pure fractions were pooled and evaporated to a syrup. The intermediate BMod5 was isolated as a syrup in 91% yield.
Synthesis of the BA Dimer
Step 6: Preparation of BMod6, TCA Formation
[0219] A 100 L reactor was charged with 5.238 Kg of 4-Lev-1-OH-2-Bz Monomer B1 (BMod5) (10.44 mol, 1 equiv) in 30 L of DCM. The reactor was purged with nitrogen and chilled to 10-15° C., after which 780 mL of diazabicyclo undecene (DBU, 795 g, 5.22 mol, 0.5 equiv) and 10.47 L of trichloroacetonitrile (TCA, 15.08 Kg, 104.4 mol, 10 equiv) were transferred into the reactor. Stirring was continued and the reaction was kept under a nitrogen atmosphere. After reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by HPLC and TLC (40:60 ethyl acetate/heptane). The reaction took approximately 2 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of dichloromethane were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was separated with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/Heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of BMod6 was 73%.
Synthesis of the BA Dimer
Step 7. Preparation of AMod1, Acetylation of Monomer A2
[0220] A 100 L reactor was charged with 6.772 Kg of Monomer A2 (17.04 mole, 1 eq.), 32.2 L (34.8 Kg, 340.8 moles, 20 eq.) of acetic anhydride and 32 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C. When the temperature reached −20° C., 3.24 L (3.63 Kg, 25.68 mol, 1.5 equiv) of boron trifluoride etherate (BF 3 .Et 2 O) was transferred into the reactor. After complete addition of boron trifluoride etherate, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 3-5 hours for completion. When the reaction was complete, extraction was performed with 3×15 L of 10% sodium bicarbonate and 20 L of water. The organic phase (DCM) was evaporated to a syrup (bath temp. 40° C.) and allowed to dry overnight. The syrup was purified in a 200 L silica column using 140 L each of the following gradient profiles: 5:95, 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of AMod1 was 83%.
Synthesis of the BA Dimer
Step 8. Preparation of AMod3, 1-Methylation of AMod1
[0221] A 100 L reactor was charged with 5891 g of acetyl Monomer A2 (AMod1) (13.98 mole, 1 eq.) in 32 L of dichloromethane. The reactor was purged with nitrogen and was chilled to 0° C., after which 2598 mL of trimethylsilyl iodide (TMSI, 3636 g, 18 mol, 1.3 equiv) was transferred into the reactor. When addition was complete, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 2-4 hours to reach completion. When the reaction was complete, the mixture was diluted with 20 L of toluene. The solution was evaporated to a syrup and was co-evaporated with 3×6 L of toluene. The reactor was charged with 36 L of dichloromethane (DCM), 3.2 Kg of dry 4A Molecular Sieves, 15505 g (42 mol, 3 equiv) of tetrabutyl ammonium iodide (TBAI) and 9 L of dry methanol. This was stirred until the TBAI was completely dissolved, after which 3630 mL of diisopropyl-ethylamine (DIPEA, 2712 g, 21 moles, 1.5 equiv) was transferred into the reactor in one portion. The completion of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 16 hours for completion. When the reaction was complete, the molecular sieves were removed by filtration. Added were 20 L EtOAc and extracted with 4×20 L of 25% sodium thiosulfate and 20 L 10% NaCl solutions. The organic layer was separated and dried with 8-12 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 5:95, 10:90, 20:80, 30:70 and 40:60 (EtOAc/heptane). The pure fractions were pooled and evaporated to give intermediate AMod3 as a syrup. The isolated yield was 75%.
Synthesis of the BA Dimer
Step 9. Preparation of AMod4, DeAcetylation of AMod3
[0222] A 100 L reactor was charged with 4128 g of 1-Methyl 4,6-Diacetyl Monomer A2 (AMod3) (10.5 mol, 1 equiv) and 18 L of dry methanol and dissolved, after which 113.4 g (2.1 mol, 0.2 equiv) of sodium methoxide was transferred into the reactor. The reaction was stirred at room temperature and monitored by TLC (40% ethyl acetate/hexane) and HPLC. The reaction took approximately 2-4 hours for completion. When the reaction was complete, Dowex 50W×8 cation resin was added in small portions until the pH reached 6-8. The Dowex 50W×8 resin was filtered and the solution was evaporated to a syrup (bath temp. 40° C.). The syrup was diluted with 10 L of ethyl acetate and extracted with 20 L brine and 20 L water. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight at the same temperature. The isolated yield of the syrup AMod4 was about 88%.
Synthesis of the BA Dimer
Step 10. Preparation of AMod5, 6-Benzoylation
[0223] A 100 L reactor was charged with 2858 g of Methyl 4,6-diOH Monomer A2 (AMod4) (9.24 mol, 1 equiv) and co-evaporated with 3×10 L of pyridine. When evaporation was complete, 15 L of dichloromethane, 6 L of pyridine were transferred into the reactor and dissolved. The reactor was purged with nitrogen and chilled to −40° C. The reactor was charged with 1044 mL (1299 g, 9.24 mol, 1 equiv) of benzoyl chloride. When the addition was complete, the reaction was allowed to warm to −10° C. over a period of 2 hours. The reaction was monitored by TLC (60% ethyl acetate/hexane). When the reaction was completed, the solution was evaporated to a syrup (bath temp. 40° C.). This was co-evaporated with 3×15 L of toluene. The syrup was diluted with 40 L ethyl acetate. Extraction was carried out with 20 L of water and 20 L of brine solution. The Ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 5:95, 10:90, 20:80, 25:70 and 30:60 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup. The isolated yield of the intermediate AMod5 was 84%.
Synthesis of the BA Dimer
Step 11. Preparation of BA1, Coupling of Amod5 with BMod6
[0224] A 100 L reactor was charged with 3054 g of methyl 4-Hydroxy-Monomer A2 (AMod5) from Step 10 (7.38 mol, 1 equiv) and 4764 g of 4-Lev-1-TCA-Monomer B1 (BMod6) from Step 6 (7.38 mol, 1 equiv). The combined monomers were dissolved in 20 L of toluene and co-evaporated at 40° C. Co evaporation was repeated with an additional 2×20 L of toluene, after which 30 L of dichloromethane (DCM) was transferred into the reactor and dissolved. The reactor was purged with nitrogen and was chilled to below −20° C. When the temperature was between −20° C. and −40° C., 1572 g (1404 mL, 11.12 moles, 1.5 equiv) of boron trifluoride etherate (BF 3 .Et 2 O) were transferred into the reactor. After complete addition of boron trifluoride etherate, the reaction was allowed to warm to 0° C. and stirring was continued. The completeness of the reaction was monitored by HPLC and TLC (40:70 ethyl acetate/heptane). The reaction required 3-4 hours to reach completion. When the reaction was complete, 926 mL (672 g, 6.64 mol, 0.9 equiv) of triethylamine (TEA) was transferred into the mixture and stirred for an additional 30 minutes, after which 20 L of water and 10 L of dichloromethane were transferred into the reactor. The solution was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was separated with 2×20 L water and 20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and used in the next step. The isolated yield of the disaccharide BA1 was about 72%.
Synthesis of the BA Dimer
Step 12, Removal of Levulinate (Methyl [(methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate)-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl]-2-deoxy-α-D-glucopyranoside)
[0225] A 100 L reactor was charged with 4.104 Kg of 4-Lev BA Dimer (BA1) (4.56 mol, 1 equiv) in 20 L of THF. The reactor was purged with nitrogen and chilled to −20 to −25° C., after which 896 mL of hydrazine hydrate (923 g, 18.24 mol, 4 equiv) was transferred into the reactor. Stirring was continued and the reaction was monitored by TLC (40% ethyl acetate/heptane) and HPLC. The reaction took approximately 2-3 hour for the completion, after which 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (ETOAc layer) was extracted with 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). The pure fractions were pooled and evaporated to dryness. The isolated yield of the BA Dimer was 82%. Formula: C 42 H 43 N 3 O 13 ; Mol. Wt. 797.80.
Synthesis of the EDC Trimer
Step 1. Preparation of EMod1, Acetylation
[0226] A 100 L reactor was charged with 16533 g of Monomer E (45 mole, 1 eq.), 21.25 L acetic anhydride (225 mole, 5 eq.) and 60 L of dichloromethane. The reactor was purged with nitrogen and was chilled to −10° C. When the temperature was at −10° C., 1.14 L (1277 g) of boron trifluoride etherate (BF 3 .Et 2 O, 9.0 moles, 0.2 eq) were transferred into the reactor. After the complete addition of boron trifluoride etherate, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by TLC (30:70 ethyl acetate/heptane) and HPLC. The reaction took approximately 3-6 hours to reach completion. When the reaction was completed, the mixture was extracted with 3×50 L of 10% sodium bicarbonate and SOL of water. The organic phase (DCM) was evaporated to a syrup (bath temp. 40° C.) and allowed to dry overnight. The isolated yield of EMod1 was 97%.
Synthesis of the EDC Trimer
Step 2. Preparation of EMod2, De-Acetylation of Azidoglucose
[0227] A 100 L reactor was charged with 21016 g of 1,6-Diacetyl Monomer E (EMod1) (45 mole, 1 eq.), 5434 g of hydrazine acetate (NH 2 NH 2 .HOAc, 24.75 mole, 0.55 eq.) and 50 L of DMF (dimethyl formamide). The solution was stirred at room temperature and the reaction was monitored by TLC (30% ethyl acetate/hexane) and HPLC. The reaction took approximately 2-4 hours for completion. When the reaction was completed, 50 L of dichloromethane and 40 L of water were transferred into the reactor. This was stirred for 30 minutes and the layers were separated. This was extracted with an additional 40 L of water and the organic phase was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight at the same temperature. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of intermediate EMod2 was 100%.
Synthesis of the EDC Trimer
Step 3. Preparation of EMod3, Formation of 1-TCA
[0228] A 100 L reactor was charged with 12752 g of 1-Hydroxy Monomer E (EMod2) (30 mole, 1 eq.) in 40 L of dichloromethane. The reactor was purged with nitrogen and stirring was started, after which 2.25 L of DBU (15 moles, 0.5 eq.) and 15.13 L of trichloroacetonitrile (150.9 moles, 5.03 eq) were transferred into the reactor. Stirring was continued and the reaction was kept under nitrogen. After the reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (30:70 ethyl acetate/Heptane) and HPLC. The reaction took approximately 2-3 hours to reach completion. When the reaction was complete, 40 L of water and 20 L of DCM were charged into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 40 L water and the DCM solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90 (DCM/EtOAc/heptane), 20:5:75 (DCM/EtOAc/heptane) and 20:10:70 DCM/EtOAc/heptane). Pure fractions were pooled and evaporated to give Intermediate EMod3 as a syrup. Isolated yield was 53%.
Synthesis of the EDC Trimer
Step 4. Preparation of ED Dimer, Coupling of E-TCA with Monomer D
[0229] A 100 L reactor was charged with 10471 g of 6-Acetyl-1-TCA Monomer E (EMod3) (18.3 mole, 1 eq., FW: 571.8) and 6594 g of Monomer D (16.47 mole, 0.9 eq, FW: 400.4). The combined monomers were dissolved in 20 L toluene and co-evaporated at 40° C. This was repeated with co-evaporation with an additional 2×20 L of toluene, after which 60 L of dichloromethane (DCM) were transferred into the reactor and dissolved. The reactor was purged with nitrogen and was chilled to −40° C. When the temperature was between −30° C. and −40° C., 2423 g (2071 mL, 9.17 moles, 0.5 eq) of TES Triflate were transferred into the reactor. After complete addition of TES Triflate the reaction was allowed to warm and stiffing was continued. The completeness of the reaction was monitored by HPLC and TLC (35:65 ethyl acetate/Heptane). The reaction required 2-3 hours to reach completion. When the reaction was completed, 2040 mL of triethylamine (TEA, 1481 g, 0.8 eq.) were transferred into the reactor and stirred for an additional 30 minutes. The organic layer (DCM layer) was extracted with 2×20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 15:85, 20:80, 25:75, 30:70 and 35:65 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The ED Dimer was obtained in 81% isolated yield.
Synthesis of the EDC Trimer
Step 5. Preparation of ED1 TFA, Hydrolysis of ED Dimer
[0230] A 100 L reactor was charged with 7.5 Kg of ED Dimer (9.26 mol, 1 equiv). The reactor was chilled to <5° C. and 30.66 L of 90% TFA solution (TFA, 370.4 mol, 40 equiv) were transferred into the reactor. When the addition was completed the reaction was allowed to warm to room temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexanes) and HPLC. The reaction took approximately 3-4 hours to reach completion. When the reaction was completed, was chilled and 51.6 L of triethylamine (TEA, 37.5 Kg, 370.4 mole) were transferred into the reactor, after which 20 L of water & 20 L ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. Ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 20:80, 30:70, 40:60, 50:50, 60:40 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup. Isolated yield of ED1 was about 70%.
Synthesis of the EDC Trimer
Step 6. Preparation of ED2, Silylation of ED1
[0231] A 100 L reactor was charged with 11000 g of 1,2-diOH ED Dimer (ED1) (14.03 mol, 1 equiv), 1910.5 g of imidazole (28.06 mol, 2 equiv) and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., after which 3.53 L butyldiphenylchloro-silane (TBDPS-Cl, 4.628 Kg, 16.835 mol, 1.2 equiv) was charged into the reactor. When the addition was complete, the chiller was turned off and the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (50% ethyl acetate/hexane) and HPLC. The reaction required 4-6 hours to reach completion. When the reaction was completed, 20 L of water and 10 L of dichloromethane were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. Dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). Intermediate ED2 was obtained in 75% isolated yield.
Synthesis of the EDC Trimer
Step 7. Preparation of ED3, D-Levulination
[0232] A 100 L reactor was charged with 19800 g of 1-Silyl ED Dimer (ED2) (19.37 moles, 1 equiv) and 40 L of dry tetrahydrofuran (THF) and agitated to dissolve. The reactor was purged with nitrogen and 237 g of dimethylaminopyridine (DMAP, 1.937 moles, 0.1 equiv) and 10.05 L of diisopropylethylamine (DIPEA, 63.9 moles, 3 equiv) were transferred into the reactor. The reactor was chilled to 10-15° C. and kept under a nitrogen atmosphere, after which 12.46 Kg of levulinic anhydride (58.11 moles, 3 eq) was charged into the reactor. When the addition was complete, the reaction was warmed to ambient temperature and stirred overnight or 12-16 hours. The completeness of the reaction was monitored by TLC (40:60 ethyl acetate/hexane) and by HPLC. 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L of water, 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The ED3 yield was 95%.
Synthesis of the EDC Trimer
Step 8. Preparation of ED4, Desilylation of ED3
[0233] A 100 L reactor was charged with 19720 g of 1-Silyl-2-Lev ED Dimer (ED3) (17.6 mol, 1 equiv) in 40 L of THF. The reactor was chilled to 0° C., after which 6903 g of tetrabutylammonium fluoride trihydrate (TBAF, 26.4 mol, 1.5 equiv) and 1511 mL (26.4 mol, 1.5 equiv) of glacial acetic acid were transferred into the reactor. When the addition was complete, the reaction was stirred and allowed to warm to ambient temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. The reaction required 3 hours to reach completion. When the reaction was completed, 20 L of water and 10 L of dichloromethane were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified using a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20 (EtOAc/heptane) and 200 L 100% EtOAc. The pure fractions were pooled and evaporated to a syrup and used in the next step. The isolated yield of ED4 was about 92%.
Synthesis of the EDC Trimer
Step 9. Preparation of ED5, TCA Formation
[0234] A 100 L reactor was charged with 14420 g of 1-OH-2-Lev ED Dimer (ED4) (16.35 mol, 1 equiv) in 30 L of dichloromethane. The reactor was purged with nitrogen and stirring was begun, after which 1222 mL of diazabicycloundecene (DBU, 8.175 mol, 0.5 equiv) and 23.61 Kg of trichloroacetonitrile (TCA, 163.5 mol, 10 equiv) were transferred into the reactor. Stirring was continued and the reaction was kept under nitrogen. After reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by HPLC and TLC (40:60 ethyl acetate/heptane). The reaction took approximately 2 hours for reaction completion. When the reaction was completed, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified using a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup and used in the next step. The isolated yield of intermediate ED5 was about 70%.
Synthesis of the EDC Trimer
Step 10. Preparation of EDC Trimer, Coupling of ED5 with Monomer C (6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-α-D-glucopyranosyl-(1→4)-benzyl (3-O-benzyl-2-O-levulinoyl)-β-D-glucopyranosyluronate-(1→4)-(3-O-acetyl-1,6-anhydro-2-azido)-2-deoxy-β-D-glucopyranose)
[0235] A 100 L reactor was charged with 12780 g of 2-Lev 1-TCA ED Dimer (ED5) (7.38 mole, 1 eq., FW) and 4764 g of Monomer C (7.38 mole, 1 eq). The combined monomers were dissolved in 20 L toluene and co-evaporated at 40° C. Repeated was co-evaporation with an additional 2×20 L of toluene, after which 60 L of dichloromethane (DCM) was transferred into the reactor and dissolved. The reactor was purged with nitrogen and chilled to −20° C. When the temperature was between −20 and −10° C., 2962 g (11.2 moles, 0.9 eq) of TES Triflate were transferred into the reactor. After complete addition of TES Triflate the reaction was allowed to warm to 5° C. and stirring was continued. Completeness of the reaction was monitored by HPLC and TLC (35:65 ethyl acetate/Heptane). The reaction required 2-3 hours to reach completion. When the reaction was completed, 1133 g of triethylamine (TEA, 0.9 eq.) were transferred into the reactor and stirred for an additional 30 minutes. The organic layer (DCM layer) was extracted with 2×20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. Dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 15:85, 20:80, 25:75, 30:70 and 35:65 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of EDC Trimer was 48%. Formula: C 55 H 60 N 6 O 18 ; Mol. Wt. 1093.09. The 1 H NMR spectrum (d6-acetone) of the EDC trimer is shown in FIG. 3 .
Preparation of EDC1 Step 1: Anhydro Ring Opening & Acetylation:
6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-1,3,6-tri-O-acetyl-β-D-glucopyranose
[0236] 7.0 Kg (6.44 mol) of EDC Trimer was dissolved in 18 L anhydrous Dichloromethane. 6.57 Kg (64.4 mol, 10 eq) of Acetic anhydride was added. The solution was cooled to −45 to −35° C. and 1.82 Kg (12.9 mol, 2 eq) of Boron Trifluoride etherate was added slowly. Upon completion of addition, the mixture was warmed to 0-10° C. and kept at this temperature for 3 hours until reaction was complete by TLC and HPLC. The reaction was cooled to −20° C. and cautiously quenched and extracted with saturated solution of sodium bicarbonate (3×20 L) while maintaining the mixture temperature below 5° C. The organic layer was extracted with brine (1×20 L), dried over anhydrous sodium sulfate, and concentrated under vacuum to a syrup. The resulting syrup of EDC1 (6.74 Kg) was used for step 2 without further purification. The 1 H NMR spectrum (d6-acetone) of the EDC-1 trimer is shown in FIG. 4 .
Preparation of EDC2
Step 2: Deacetylation
6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-β-D-glucopyranose
[0237] The crude EDC1 product obtained from step 1 was dissolved in 27 L of Tetrahydrofuran and chilled to 15-20° C., after which 6 Kg (55.8 mol) of benzylamine was added slowly while maintaining the reaction temperature below 25° C. The reaction mixture was stirred for 5-6 hours at 10-15° C. Upon completion, the mixture was diluted with ethyl acetate and extracted and quenched with 10% citric acid solution (2×20 L) while maintaining the temperature below 25° C. The organic layer was extracted with 10% NaCl/1% sodium bicarbonate (1×20 L). The extraction was repeated with water (1×10 L), dried over anhydrous sodium sulfate and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel yielded 4.21 Kg (57% yield over 2 steps) of EDC2 [also referred to as 1-Hydroxy-6-Acetyl EDC Trimer]. The 1 H NMR spectrum (d6-acetone) of the EDC-2 trimer is shown in FIG. 5 .
Preparation of EDC3
Step 3: Formation of TCA Derivative
6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-1-O-trichloroacetimidoyl-β-D-glucopyranose
[0238] 4.54 Kg (3.94 mol) of EDC2 was dissolved in 20 L of Dichloromethane. 11.4 Kg (78.8 mol, 20 eq) of Trichloroacetonitrile was added. The solution was cooled to −15 to −20° C. and 300 g (1.97 mol, 0.5 eq) of Diazabicycloundecene was added. The reaction was allowed to warm to 0-10° C. and stirred for 2 hours or until reaction was complete. Upon completion, water (20 L) was added and the reaction was extracted with an additional 10 L of DCM. The organic layer was extracted with brine (1×20 L), dried over anhydrous sodium sulfate, and concentrated under vacuum to a syrup. Column chromatographic separation using silica gel and 20-60% ethyl acetate/heptane gradient yielded 3.67 Kg (72% yield) of 1-TCA derivative, EDC3. The 1 H NMR spectrum (d6-acetone) of the EDC-3 trimer is shown in FIG. 6 .
Preparation of EDCBA1
Step 4: Coupling of EDC3 with BA Dimer
Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl)-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside
[0239] 3.67 Kg (2.83 mol) of EDC3 and 3.16 Kg (3.96 mol, 1.4 eq) of BA Dimer was dissolved in 7-10 L of Toluene and evaporated to dryness. The resulting syrup was coevaporated with Toluene (2×15 L) to remove water. The dried syrup was dissolved in 20 L of anhydrous Dichloromethane, transferred to the reaction flask, and cooled to −15 to −20° C. 898 g (3.4 mol, 1.2 eq) of triethylsilyl triflate was added while maintaining the temperature below −5° C. When the addition was complete, the reaction was immediately warmed to −5 to 0° C. and stirred for 3 hours. The reaction was quenched by slowly adding 344 g (3.4 mol, 1.2 eq) of Triethylamine. Water (15 L) was added and the reaction was extracted with an additional 10 L of DCM. The organic layer was extracted with a 25% 4:1 Sodium Chloride/Sodium Bicarbonate solution (2×20 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. The resulting syrup of the pentasaccharide, EDCBA1 was used for step 5 without further purification. The 1 H NMR spectrum (d6-acetone) of the EDCBA-1 pentamer is shown in FIG. 7 .
Preparation of EDCBA2
Step 5: Hydrolysis of Levulinyl Moiety
Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl)-(1→4)-O-[benzyl 3-O-benzyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl)-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside
[0240] The crude EDCBA1 from step 4 was dissolved in 15 L of Tetrahydrofuran and chilled to −20 to −25° C. A solution containing 679 g (13.6 mol) of Hydrazine monohydrate and 171 g (1.94 mol) of Hydrazine Acetate in 7 L of Methanol was added slowly while maintaining the temperature below −20° C. When the addition was complete, the reaction mixture was allowed to warm to 0-10° C. and stirred for several hours until the reaction is complete, after which 20 L of Ethyl acetate was added and the reaction was extracted with 10% citric acid (2×12 L). The organic layer was washed with water (1×12 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel and 10-45% ethyl acetate/heptane gradient yielded 2.47 Kg (47.5% yield over 2 steps) of EDCBA2. The 1 H NMR spectrum (d6-acetone) of the EDCBA-2 pentamer is shown in FIG. 8 .
Preparation of EDCBA Pentamer
Step 6: THP Formation
Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside
[0241] 2.47 Kg (1.35 mol) of EDCBA2 was dissolved in 23 L Dichloroethane and chilled to 10-15° C., after which 1.13 Kg (13.5 mol, 10 eq) of Dihydropyran and 31.3 g (0.135 mol, 0.1 eq) of Camphorsulfonic acid were added. The reaction was allowed warm to 20-25° C. and stirred for 4-6 hours until reaction was complete. Water (15 L) was added and the reaction was extracted with an additional 10 L of DCE. The organic layer was extracted with a 25% 4:1 Sodium Chloride/Sodium Bicarbonate solution (2×20 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel and 10-35% ethyl acetate/heptane gradient yielded 2.28 Kg (88.5% yield) of fully protected EDCBA Pentamer. The 1 H NMR spectrum (d6-acetone) of the EDCBA pentamer is shown in FIG. 9 .
Preparation of API1
Step 1: Saponification
Methyl O-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-azido-2-deoxy-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-α-L-Idopyranosyluronosyl-(1→4) 2-azido-3-O-benzyl-2-deoxy-α-D-glucopyranoside disodium salt
[0242] To a solution of 2.28 Kg (1.19 mol) of EDCBA Pentamer in 27 L of Dioxane and 41 L of Tetrahydrofuran was added 45.5 L of 0.7 M (31.88 mol, 27 eq) Lithium hydroxide solution followed by 5.33 L of 30% Hydrogen peroxide. The reaction mixture was stirred for 10-20 hours to remove the acetyl groups. Then, 10 L of 4 N (40 mol, 34 eq) sodium hydroxide solution was added. The reaction was allowed to stir for an additional 24-48 hours to hydrolyze the benzyl and methyl esters completely. The reaction was then extracted with ethyl acetate. The organic layer was extracted with brine solution and dried with anhydrous sodium sulfate. Evaporation of the solvent under vacuum gave a syrup of API1 [also referred to as EDCBA(OH) 5 ] which was used for the next step without further purification.
Preparation of API2
Step 2: O-Sulfonation
Methyl O-2-azido-2-deoxy-3,4-di-O-benzyl-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-azido-2-deoxy-3,6-di-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-azido-2-deoxy-6-O-sulfo-α-D-glucopyranoside, heptasodium salt
[0243] The crude product of API1 [aka EDCBA(OH) 5 ] obtained in step 1 was dissolved in 10 L Dimethylformamide. To this was added a previously prepared solution containing 10.5 Kg (66 moles) of sulfur trioxide-pyridine complex in 10 L of Pyridine and 25 L of Dimethylformamide. The reaction mixture was heated to 50° C. over a period of 45 min After stiffing at 1.5 hours at 50° C., the reaction was cooled to 20° C. and was quenched into 60 L of 8% sodium bicarbonate solution that was kept at 10° C. The pH of the quench mixture was maintained at pH 7-9 by addition of sodium bicarbonate solution. When all the reaction mixture has been transferred, the quench mixture was stirred for an additional 2 hours and pH was maintained at pH 7 or greater. When the pH of quench has stabilized, it was diluted with water and the resulting mixture was purified using a preparative HPLC column packed with Amberchrom CG161-M and eluted with 90%-10% Sodium Bicarbonate (5%) solution/Methanol over 180 min. The pure fractions were concentrated under vacuum and was then desalted using a size exclusion resin or gel filtration (Biorad) G25 to give 1581 g (65.5% yield over 2 steps) of API2 [also referred to as EDCBA(OSO 3 ) 5 ]. The 1 H NMR spectrum (d6-acetone) of API-2 pentamer is shown in FIG. 10 .
Preparation of API3
Step 3: Hydrogenation
Methyl O-2-amino-2-deoxy-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-amino-2-deoxy-3,6-di-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-amino-2-deoxy-6-O-sulfo-α-D-glucopyranoside, heptasodium salt
[0244] A solution of 1581 g (0.78 mol) of O-Sulfated pentasaccharide API2 in 38 L of Methanol and 32 L of water was treated with 30 wt % of Palladium in Activated carbon under 100 psi of Hydrogen pressure at 60-65° C. for 60 hours or until completion of reaction. The mixture was then filtered through 1.0μ and 0.2μ filter cartridges and the solvent evaporated under vacuum to give 942 g (80% yield) of API3 [also referred to as EDCBA(OSO 3 ) 5 (NH 2 ) 3 ]. The 1 H NMR spectrum (d6-acetone) of API-3 pentamer is shown in FIG. 11 .
Preparation of Fondaparinux Sodium
Step 4: N-Sulfation & Removal of THP
Methyl O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-β-D-glucopyranuronosyl-(1→4)-O-2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside, decasodium salt
[0245] To a solution of 942 g (0.63 mol) of API3 in 46 L of water was slowly added 3.25 Kg (20.4 mol, 32 eq) of Sulfur trioxide-pyridine complex, maintaining the pH of the reaction mixture at pH 9-9.5 during the addition using 2 N sodium hydroxide solution. The reaction was allowed to stir for 4-6 hours at pH 9.0-9.5. When reaction was complete, the pH was adjusted to pH 7.0 using 50 mM solution of Ammonium acetate at pH 3.5. The resulting N-sulfated EDCBA(0SO 3 ) 5 (NHSO 3 ) 3 mixture was purified using Ion-Exchange Chromatographic Column (Varian Preparative 15 cm HiQ Column) followed by desalting using a size exclusion resin or gel filtration (Biorad G25). The resulting mixture was then treated with activated charcoal and the purification by ion-exchange and desalting were repeated to give 516 g (47.6% yield) of the purified Fondaparinux Sodium form.
[0246] Analysis of the Fondaparinux sodium identified the presence of P1, P2, P3, and P4 in the fondaparinux. P1, P2, P3, and P4 were identified by standard analytical methods.
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Processes for the synthesis of the Factor Xa anticoagulent Fondaparinux, and related compounds are described. Also described are protected pentasaccharide intermediates as well as efficient and scalable processes for the industrial scale production of Fondaparinux sodium by conversion of the protected pentasaccharide intermediates via a sequence of deprotection and sulfonation reactions.
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FIELD OF THE INVENTION
[0001] The present invention relates to an elevator drive for driving and holding an elevator car, as well as a brake device, a corresponding method and an elevator installation.
BACKGROUND OF THE INVENTION
[0002] An electromagnetically actuable brake device, such as can be used in an elevator drive, with a stationary housing and a drive shaft rotatable therein is known from DE 197 37 485 C1. Two brake discs are connected with the drive shaft to be secure against rotation relative thereto, but are axially displaceable. Axially displaceable armature discs are each biased, through a respective spring, by a normal force against the brake discs in such a manner that a first frictional contact between the brake discs and the housing and a second frictional contact between the armature discs, which are secure against rotation relative to the housing, and the brake disc are formed. The frictional forces acting in these contacts oppose a rotation between the brake disc, which is rotationally fixed to the drive shaft, and the housing or the armature disc, which is rotationally fixedly connected therewith, and thus brake the drive shaft. In order to release the brake the armature discs are electromagnetically released against the springs. The armature discs are of three-part construction so as to reduce noise arising when the brake is applied.
[0003] If such a brake device can exert only a reduced friction force between armature discs and brake discs due to wear in the brake discs it is possible for slipping of the armature discs on the brake part discs bearing thereagainst to arise. This jeopardises safety.
SUMMARY OF THE INVENTION
[0004] It is therefore an object of the present invention to provide an elevator drive with a brake device which increases the safety of the elevator drive.
[0005] A brake device is usually installed in an elevator drive. The drive serves for driving and holding an elevator car and it substantially comprises a traction wheel or a drive pulley for transmitting a driving and/or holding force to the elevator car, a motor for driving the traction wheel and a brake arrangement for holding the traction wheel. A drive shaft connects the traction wheel, motor and brake arrangement together. The brake arrangement comprises at least two brake devices, wherein, according to one aspect of the invention, the traction wheel is arranged between the brake devices. This is advantageous, since the braking moments which have to be transmitted by the traction wheel to the brake devices are split up. In an advantageous symmetrical division of the brake devices, namely half on each side of the traction wheel, a moment, which is to be transmitted, in the drive shaft is reduced to half. A risk of failure or risk of fracture of the drive shaft is thereby significantly reduced. In addition, if failure of the drive shaft should occur a braking function is still maintained, since the brake devices are distributed to either side of the traction wheel. The terms “traction wheel” and “drive pulley” have the same meaning with respect to the present invention.
[0006] Advantageously, the brake devices are arranged substantially at the two ends of the drive shaft. Easy access for maintenance and installation is thereby provided.
[0007] Advantageously, the brake devices arranged on either side of the traction wheel are individually controllable. Thus, when required a monitoring logic system can selectively ascertain whether one brake device alone is in a position of keeping the elevator car at standstill. This is advantageously carried out in that the activation of the brake devices for application thereof takes place with a small delay in time or that, alternatively, during a stop of the elevator car and if advantageously at the same time there is no reported need for transport, one brake device is temporarily released. The monitoring logic system can ascertain, during the time period when only one of the brake devices is applied, whether the one brake device alone is in a position of keeping the elevator car at standstill. This is additionally advantageous, since the overall function of the brake arrangement can thereby be checked.
[0008] The elevator drive according to the invention is usually arranged in stationary position in a travel shaft and drives the elevator car by way of support means. The support means are in this connection wound up on or unwound from the elevator drive or the traction wheel or frictionally driven by the traction wheel or the drive pulley. When friction is used a counterweight, which guarantees a sufficient counter-force, is usually fastened to the end of the support means opposite to the elevator car. In that case obviously the elevator car and correspondingly the counterweight can be directly suspended or they can be multiply suspended by means of a block-and-tackle arrangement.
[0009] However, the elevator drive can also co-travel, thus be arranged directly at the elevator car, wherein then the traction wheel acts on a stationary part, such as a rail with friction surface, a rack or spindle or, for example, a cable.
[0010] Advantageously, the brake device or at least one of the brake devices comprises an elevator drive of that kind, further in general a static element and a movable element or the drive shaft, which is movable relative to the static element in a first degree of freedom and is to be braked relative to the static element.
[0011] The term “braking” can in that case equally embrace braking of the element movable relative to the static element, thus reduction of the relative speed thereof, and also complete stopping or holding of the movable element. The distinction between static element and movable element serves in the present instance only for differentiation of two elements movable relative to one another in a degree of freedom. In particular, for example, one of the static element and movable element can be arranged to be inertially fixed in order to brake the other one of the static element and movable element relative to the surroundings. The brake device can in that case be constructed as, in particular, a parking brake for holding the car.
[0012] This is the normal case with current elevator installations, since the elevator car or the drive parts, such as drive, counterweight and support means, connected with the car are decelerated to standstill in regulated manner by electromotive force and the brake device consequently only has to hold the already stationary car. However, a brake device of that kind obviously has to take over, apart from the parking function, also a braking function if, for example, in the event of a fault such as, for example, interruption of power rapid stopping of the elevator car has to be carried out.
[0013] The first degree of freedom can be, for example, a degree of freedom in rotation. For this purpose the movable element can be rotatably mounted in the static element. In this sense the term “force” embraces generally the forces or torques, which act in the respective degree of freedom, in order to together represent the present invention, the invention being able to be used in different brake devices acting in different degrees of freedom. If therefore, “friction force” is mentioned this embraces, in the case of degrees of freedom in rotation, also the effective friction torque.
[0014] The first degree of freedom can also be a degree of freedom in translation. For this purpose the movable element can be displaceably mounted in the static element, such as is known from, for example, DE 41 06 595 A1, in which a static element in the form of a measuring brake linearly slides along a movable element in the form of a brake engagement rail.
[0015] A first frictional contact in a first contact surface can be selectably formed between the static element and the movable element by a controllable normal force, which acts in a second degree of freedom. In the first frictional contact a first friction force opposes movement of the movable element relative to the static element. In DE 197 37 485 C1 for this purpose the brake discs are, for example, pressed against the housing in a first contact surface. The first friction forces arising in these frictional contacts oppose rotation of the drive shaft, which is connected with the brake discs to be secure against rotation relative thereto. As explained in the foregoing, the term “friction force” in that case embraces, having regard to the degree of freedom of the drive shaft in rotation, the friction torque acting thereon.
[0016] In addition, one or more relative elements are provided in such a manner that a second frictional contact in a second contact surface is formed between the movable element and each of the relative elements by the normal force and in the second frictional contact a second friction force opposes movement of the movable element relative to the relative element. In DE 197 37 485 C1, for example, a first part disc of each three-part armature disc presses against the associated brake disc when the normal force urges the brake disc against the housing. The second friction forces arising in these frictional contacts oppose rotation of the drive shaft, which is connected with the brake discs to be secure against rotation relative thereto, relative to the first part discs, which are connected with the housing to be secure against rotation relative thereto.
[0017] Moreover, an actuating element fixed in the first degree of freedom relative to the static element is preferably associated with each relative element, wherein a third frictional contact in a third contact surface is formed between the actuating element and the relative element by the normal force and in the third frictional contact a third friction force opposes movement of the relative element relative to the actuating element. In DE 197 37 485 C1, for example, a second part disc of the three-art armature disc presses on the first part disc when the normal force urges the brake disc against the housing. The third friction forces arising in these friction contacts oppose rotation of the first part discs relative to the second part discs. The first, second and/or third contact surface is or are preferably loaded by the same normal force.
[0018] In a frictional contact an equal friction force FR, which can adopt the maximum value FRmax=μ×FN, opposing the sum of the remaining forces normally always arises, wherein FN denotes the normal force acting on the contact surface and μ denotes a coefficient of friction. If in that case static friction (Index H) is present a friction force FR H =μ H ×FN can thus maximally arise. If the sum of the remaining acting forces exceeds this value then the frictional contact changes from static friction to sliding friction (index G) and the coefficient of friction FR G =μ G ×FN arises. The term “sliding friction” in that case also embraces rolling friction such as occurs, for example, during rolling of roller bearings.
[0019] According to one variant of embodiment of the elevator drive according to the invention a relative element of the brake device is now movable in the first degree of freedom relative to the static element between a normal position and a braking position and is resiliently biased into the normal position, wherein the second and third contact surfaces are so constructed that a maximum second friction force, particularly in the case of sticking in the second and third frictional contact, is greater than a maximum third friction force. Movement of the relative element in the first degree of freedom out of the braking position is prevented, for example by a mechanically positive and/or frictional couple. For this purpose abutments can preferably limit movement of the relative element between normal position and braking position.
[0020] This has the following mechanical consequence: If the movable element is held, the normal force FN acts in the second degree of freedom, all three frictional contacts are formed and static friction prevails. Since the third friction force FR 3 H acting between the relative element and the actuating element, which is fixed in the first degree of freedom relative to the static element, is always smaller than the second friction force FR 2 max H which can maximally act between the relative element and the movable element, this smaller third friction force FR 3 H limits that friction force which is transmitted between the static element and the movable element by way of the actuating element and the relative element. Together with the first friction force FR 1 H , which can be transmitted directly to the first contact surface, i.e. without interposition of the actuating element and relative element, the entire friction force FR H acting on the movable element thus appears as the sum of these two friction forces:
[0000] FR H =FRI H +FR 3 H (1)
[0021] If, in operation, this friction force is now no longer sufficient to hold the movable element, which can result particularly from wear or contamination leading to a diminishing normal force and/or a reduced coefficient of friction in the contact surfaces, slipping of the movable element relative to the static element in the first degree of freedom occurs.
[0022] In this case the movable element moves in the first degree of freedom even in the presence of normal force FN. Since the maximum second friction force between relative element and movable element is, in accordance with the invention, greater than the maximum third friction force between relative element and actuating element, static friction is again present in the second frictional contact, whereas the third frictional contact transfers to sliding (or rolling). In that case the movable element entrains the relative element in the first degree of freedom until it goes out of its normal position and into the braking position and is stopped there, for example in mechanically positive manner, by an abutment or the like. The relative element is consequently switched automatically, i.e. without external control influence, from the normal position to the braking position and this change takes place in both travel directions, thus rearwards and forwards.
[0023] As soon as the relative element is stopped in the braking position and fixed in the first degree of freedom relative to the static element, the second friction force FR 2 is transmitted from the static element to the movable element by way of the second contact surface between relative element and movable element. The entire friction force FR acting on the movable element thus arises as the sum of these two friction forces:
[0000] FR=FR 1+ FR 2 (1′)
[0000] > FR 1 +FR 3 (1″)
[0024] If in a brake device according to the present invention the entire friction force FR=FR 1 +FR 3 designed for holding the movable element in the normal case is then no longer sufficient for holding the movable element, this thus moves in the first degree of freedom and in that case shifts, as described in the foregoing, the relative element into its braking position, where it is fixed relative to the static element and transmits the second, greater friction force FR 2 to the movable element, so that the entire friction force of FR 1 +FR 3 acting thereon increases to FR 1 +FR 2 . Advantageously, a safety margin S=(FR 1 +FR 2 )/(FR 1 +FR 3 ) can thereby be made available for the case that the normal total friction force is no longer sufficient, for example because the first and/or third contact surface has or have wear or oil contamination or the normal force diminishes.
[0025] This shifted build-up of the total force required for braking has a further favourable effect insofar as a force pulse on the entire moved system is reduced, due to the fact that the braking force is built up by way of two stages.
[0026] Alternatively, instead of the third contact surface and the actuating element use can also be made of, for example, a pressing spring which on the one hand can produce urging of the relative element in the second degree of freedom and on the other hand enables relative displacement of the relative element in the first degree of freedom between normal position and braking position. In this embodiment the relative element can, for example, be constructed at the same time as an armature plate. In this form of embodiment the value of the friction force of the third contact surface (FR 3 ) reduces virtually to zero. If in the following embodiments the third contact surface is always used, it is also to be understood with respect thereto that this third contact surface can, as described, be eliminated and the associated friction force (FR 3 ) adopt the value zero.
[0027] It can be difficult to simply and reliably detect a faulty function in a brake device. Such a faulty function can be present, for example, if the brake device during travel operation does not release or if, as described in the foregoing, it exerts only a reduced braking force. For this purpose, for example, it is known to manually carry out, within operation, a check of braking force and wear at maintenance intervals, which is costly in terms of time and personnel as well as susceptible to error.
[0028] In a preferred embodiment of the present invention the brake device therefore comprises a sensor device for detecting the normal and/or braking position of the relative element. Such a sensor device can be, for example, a contact which is closed when the relative element comes into braking position and/or is opened as soon as the relative element leaves the normal position. Equally, for example, optical sensors can monitor the position of the relative element or position transmitters detect the position of the relative element.
[0029] If, as described in the foregoing, the movable element moves, even when subject to normal force FN, in the first degree of freedom the movable element entrains the relative element in the first degree of freedom until it passes from its normal position into the braking position.
[0030] This movement of the relative element is recognized by the sensor device for detecting the normal and/or braking position. Since the relative element is biased into the normal position and remains therein when the total friction force FR H =FR 1 H +FR 3 H is sufficient for holding, thus in the case of normal, fault-free operation, it is possible to reliably conclude—from a shift of the relative element from the normal position to the braking position—faulty functioning of the brake device and the corresponding elevator drive and, for example, to issue a warning to an elevator control.
[0031] An advantage of the invention arises through the use of an expedient monitoring logic system which monitors correct functioning of the brake device. This monitoring logic system comprises the sensor device for detecting the normal and/or braking position of the relative element, a speed and/or travel measuring device and the control signal for the brake device. On occasion, the brake device can also be provided with a further sensor for ascertaining the state “contact play removed” or “brake applied” or “contact play present” or “brake released”. In the following a “control signal brake” signals the command state which a control device gives to the brake device as control signal (“apply” or “release”). The “speed” corresponds with the state of the movable element or the travel body or elevator car and indicates whether the movable element is disposed at standstill (0) or in motion (≠0).
[0032] A diagnosis of the state can then follow, for example, the following diagram:
[0000]
Control signal
Position of relative
brake
Speed
element
Determination
Apply
Release
0
≠0
Normal
Braking
In order
F1
X
X
X
F2
X
X
X
Brake fault/
Overload
F3
X
X
X
In order
F4
X
X
X
In order
F5
X
X
X
Release fault
[0033] This diagnostic diagram allows an almost constant monitoring of the function of the brake device, particularly since at each stop (F1, F2) the desired state can be detected and in the event of deviation appropriate measures can be undertaken. No risk exists, since on reaching the braking position an increased braking force, usually a braking force increased by approximately the factor 2, is available. Secure holding is thus guaranteed.
[0034] Equally, on determination of a release fault (F5) the installation can be stopped and the function verified. On the basis of a fault history, which is stored in the monitoring logic system, servicing can be performed in targeted manner.
[0035] A free-running travel of the relative element can in that case be kept small. It can be selected to be merely of such size that reliable determination of the position of the relative element by the sensor device is made possible in simple manner and, on the other hand, no risky deviation in holding such as, for example, formation of a step in the case of an elevator car arises due to the resulting displacement of the movable element or of the travel body. The selected free-running travel is typically approximately 3 to 10 millimeters in each of two directions of movement in correspondence with the first degree of freedom.
[0036] The relative element is kept in its normal position, or returned again to the normal position after relative displacement has taken place, by means of a bias. This bias can be produced by means of, for example, a resilient spring, for example a simple torsion bar, a mechanical torsion spring or helical spring, or also a hydraulic spring. Biasing by means of magnetic force is also possible, in that magnetic poles are appropriately arranged. In the case of use, in particular, of a pressing spring instead of the actuating element as explained in the foregoing, the biasing device can be combined with a magnetic release unit.
[0037] In the foregoing the bias, which is to be overcome by the relative element on movement from the normal position to the braking position and which seeks to bias the relative element into or restore it to the normal position, was disregarded. Advantageously, however, the second and third contact surfaces are so constructed that the maximum second friction force, particularly in the case of adhesion in the second and third frictional contact, is also greater than the sum of the maximum third friction force and the force KV biasing the relative element into its normal position:
[0000] FR 2max H >FR 3max H +KV (2)
[0000] which in the case of a negligibly small force KV for
[0000] FR2max H >FR3max H (2′)
[0000] is fulfilled, particularly if the second friction force is substantially greater than the third friction force:
[0000] FR2max H >>FR3max H (2″).
[0038] Since, in addition, relatively large friction forces FR 2 H , FR 3 H regularly arise in brake devices, particularly for elevator installations, Equation (2) is also applicable in good approximation with Equation (2′) or (2″).
[0039] In the foregoing there was explanation of the case of holding the movable element, in which static friction prevailed in each of the first, second and third frictional contact. If the brake device is provided as a parking brake for holding, only this case arises.
[0040] If, however, the brake device is additionally employed for braking the movable element, then the movable element further moves in the first degree of freedom during braking even when subjected to the normal force and in that case by reason of the afore-described principle seeks to entrain the relative element and draw it from its normal position to its braking position. In this case sliding friction is present in the first and at least in the second or third frictional contact.
[0041] For this case the force KV biasing the relative element into the normal position can be so designed that in the course of a normal braking procedure it sufficiently compensates, together with the third friction force, for the second friction force and thus holds the relative element in its normal position. The biasing can in general be produced by means of, for example, a resilient spring, for example a mechanical torsion or helical spring or a hydraulic spring. When the movable element is finally braked to a standstill and subsequently held, then the contact states in the first, second and third frictional contact, respectively, change from sliding friction to static friction. The thus-arising static friction forces are in general significantly higher than the friction forces, which prevail during braking, in sliding friction (or rolling friction).
[0042] If the total static friction force FR H =FR 1 H +FR 3 H is no longer sufficient for holding the movable element, the relative element, as described in the foregoing, ultimately shifts into its braking position and is fixed there, which in the preferred embodiment is detected by the sensor device. Since the sliding friction is in general significantly lower than the static friction, the relative element can during braking, in which sliding friction occurs in at least some of the contact surfaces, be held in its normal position by a small bias, whereas in the case of holding, in which static friction and thus a higher second and third friction force are present, the above-described mechanism for ensuring a sufficient total friction force or for detection of an erroneously low total static friction force FR H =FR 1 H +FR 3 H comes into being.
[0043] In a preferred embodiment the second and third contact surfaces are therefore constructed in such a manner that the second friction force FR 2 G , which arises in the second frictional contact during sliding, is less than the sum of the force KV, which biases the relative element into its normal position, and the third friction force FR 3 G and/or FR 3 H , which arises or arise in the third frictional contact during sliding or adhesion. The relative element is thereby held in its normal position during braking. At the same time, in this preferred embodiment the second and third contact surfaces are constructed in such a manner that the maximum second friction force FR 2 max H , which can maximally arise in the second frictional contact in the case of adhesion, is greater than the sum of the force KV, which biases the relative element into its normal position, and the third friction force FR 3 max H , which can arise in the third frictional contact in the case of adhesion. As explained in the foregoing, this is simple to realize, since the static friction forces are in general significantly higher than the sliding friction forces. Thus, in the preferred embodiment:
[0000] FR 2 G <KV+FR 3 G (3)
[0000] FR 2max H >KV+FR 3max H (2)
[0044] However, fulfilment of the condition (2) is as a rule already sufficient for the following reason: When the brake device begins the braking process, the first, second and third frictional contacts are formed. In that case, sliding friction is immediately present in the second frictional contact between the movable element, which initially moves relative to the static element, and the relative element, which is biased into its normal position of being stationary relative to the static element. Static friction is initially present in the third frictional contact between the relative element and the actuating element as long as the relative element is not accelerated. Now, as mentioned in the foregoing, the sliding friction is in general significantly lower than the maximum static friction. The second frictional force FR 2 G acting in the second frictional contact is thus in general lower than the third friction force FR 3 max H which can maximally arise in the third friction contact. Thus, in the usual case (insofar as relative element and actuating element do not move relative to one another) the second friction force in the second frictional contact, in which sliding friction prevails, is significantly smaller during braking than the third friction force in the third frictional contact, in which static friction prevails. The relative element is thus held in its normal position until the movable element has completely come to a stop. Thus, at the start of braking
[0000] FR 2 G <FR 3max H +KV (3′)
[0000] so that the relative element does not move relative to the actuating element, but remains in its normal position, whilst sliding friction is present in the second frictional contact. As soon as the movable element is stationary, the second frictional contact also changes from sliding friction to static friction and
[0000] FR 2max H >KV+FR 3max H (2)
[0045] If the remaining forces acting on the movable element now exceed the maximum friction forces provided by the brake device
[0000] FR max H =FR 1max H +FR 3max H (1′″),
[0000] the relative element is shifted from its normal position into the braking position and fixed there, wherein advantageously a faulty function can be recognized. As explained, the fulfilment of the condition (2) or, with disregard of the force KV, the condition (2′) is sufficient to increase the safety of the brake device and to detect a faulty function in the case of a brake device which only holds. If the movable element is also braked by the brake device, fulfilment of the condition (3) or (3′) is also sufficient in order to ensure that the relative element remains in its normal position during the normal braking process, so that subsequently the afore-described safety margin is available and advantageously a faulty function in the case of holding can be ascertained.
[0046] Condition (3′) is as a rule fulfilled simultaneously with condition (2) or (2′), since the sliding friction (or rolling friction) is usually significantly lower than the static friction. Thus, in accordance with the invention it is generally only required for the maximum friction force FR 2 max, which is present in the second frictional contact and is usually defined by the maximum static friction force FR 2 max H , to be larger than the maximum friction force FR 3 max, which is present in the third frictional contact and is usually defined by the maximum static friction force FR 3 max H (condition (2′)). Thus, in general condition (3′) is also fulfilled, so that, even in the case of braking, the relative element is kept in its normal position until the held state is attained.
[0047] Advantageously, however, this fine-turning of the bias is dispensed with when the brake device is employed primarily as a holding or parking brake and used for dynamic braking of the travel body only in the case of need. A case of need is, for example, response of a speed monitoring circuit or a power failure, etc. In such a case of need it is then certainly desired for the relative element to be entrained without delay into the braking position (B) and then necessarily produce a higher braking force. The requirement for the bias is then correspondingly low and it is merely designed in order to move the unloaded relative element (3) back into the normal position and releasably keep it there with low force.
[0048] The maximum second friction force can, for example, be predetermined to be greater than the maximum third friction force in that the second contact surface has a higher coefficient of friction than the third contact surface. The conditions (2) or (2′) and (3) or (3′) can thus be fulfilled. If relative element and actuating element are subjected to the same normal force FN, then a maximum second friction force FR 2 =μ2×FN greater than the maximum third friction force FR 3 =μ 3 ×FN thus arises. For that purpose the second and third contact surfaces can, for example, consist of different material. Accordingly, the relative element can have on the second contact surface a coating for increasing the coefficient of friction μ 2 and/or the actuating element can have on the third contact surface a coating for reducing the coefficient of friction μ 3 . Roller bearings, particularly needle bearings, for representation of specific coefficients of friction can also be arranged in the third contact surface.
[0049] In a preferred embodiment the coefficients of friction of the first and second contact surfaces are substantially the same, so that substantially the same friction forces arise in the first and second frictional contacts, which can advantageously distribute the loads more evenly. The term “coefficient of friction” can in the present case embrace not only the coefficient of static friction, but also the coefficient of sliding or rolling friction of a frictional contact, wherein in practical application the first and second frictional contacts are executed in proven mode and manner as a brake friction lining.
[0050] The maximum second friction force can alternatively or additionally be predetermined to be greater than the maximum third friction force in that the third contact surface is inclined relative to the normal force. A correspondingly lower normal force thus acts on the inclined third contact surface and consequently a correspondingly lower third friction force. Advantageously, the normal force acting in the first, second and third frictional contact divides, in the case of an inclined third contact surface, into a component which is normal to the third contact surface and induces the third friction force and a component which is tangential to the third contact surface and adds to the third friction fore when there is movement in a direction in the first degree of freedom, or subtracts therefrom when there is opposite movement, to form a third total friction force. Thus, in the case of opposite movements in the first degree of freedom different third total friction forces could be represented. Advantageously, in the case of use of the inclined third contact surface a change in the normal force arises when there is relative movement between relative element and actuating element, since, for example, springs employed for producing this normal force are stressed or relaxed. This is advantageously employed in the case of use in, for example, elevator installations with partly balanced counterweights, since different braking actions can thus be produced depending on a possible direction of slip.
[0051] As mentioned in the foregoing translational forces and torques acting in the respective degree of freedom are to be understood by the term “force” in the present invention. Different friction forces can therefore also be represented by different lever arms. Thus, for example, a greater second friction force (in this case a torque) can be represented in that the second frictional contact is radially spaced further from an axis of rotation of the movable element than the third frictional contact. In the case of equal normal force, different friction forces—in this case torques—thus result.
[0052] The relative element and the actuating element can preferably be so moved by the normal force in the second degree of freedom that the first, second and third frictional contacts are formed. This makes possible a simple mechanical realization of the frictional contacts. In particular, a brake element can be provided which is fixed in the first degree of freedom relative to the movable element and is so moved by the normal force in the second degree of freedom that the first, second and third frictional contacts are formed. Equally, the movable element can be so moved relative to the static element by the normal force in the second degree of freedom, in particular resiliently deformed that the first, second and third frictional contact is formed.
[0053] The actuating element can, in a manner known by way of example from DE 197 37 485 C1 or DE 41 06 595 A1, be biased, particularly by resilient means, by the normal force and selectably released electromagnetically and/or hydraulically. In the event of failure of a voltage applied to an electromagnet, a pressure decay in a hydraulic line or a fault in the control of the brake device the actuating element is no longer released, so that the normal force forms the frictional contact and thus applies the brake device. In the case of a defect the brake device thus applies independently and automatically.
[0054] The elevator drive according to the invention accordingly comprises a brake device which is constructed in such a manner that the brake device when the travel body or movable element is stationary can be switched to a normal position in which the brake device generates a first holding force. This holding force is designed to keep the movable element at standstill. Moreover, in the case of a possible movement of the movable element and regardless of the direction of movement the brake device automatically changes from the normal position to a braking position. In the braking position the brake device produces a substantially doubled or multiplied holding force or braking force.
[0055] Advantageously, this automatic change from the normal position to the braking position is monitored by means of a sensor device. The advantage of this part of the invention is that a first slipping of the movable element can be recognized by means of the sensor device and that an automatic amplification of the holding force results, whereby further slipping is prevented.
[0056] Advantageously, the elevator drive is used in an elevator which accelerates the travel body on each occasion in regulated manner from standstill, for example by electric motor or hydraulically, and decelerates again to standstill, whereby the brake device is in the normal case employed only for holding the travel body at standstill.
[0057] An elevator drive according to the invention with a brake device can comprise a plurality of relative elements as well as actuating elements respectively associated therewith, as is basically known from, for example, DE 197 37 485 C1. The total friction forces explained in the foregoing then result from the sum of the first and third or second friction forces.
[0058] As explained in the foregoing, one of the possible faulty functions of a brake device can consist in an entire friction force, which is composed of the first and third friction force, being too small in order to hold the movable element at standstill. This faulty function can be recognized if the sensor device detects that the relative element is no longer disposed in its normal position. In that case a movement of the relative element is preferably limited by abutments. As a result, when these abutments are reached the second friction force, which is higher by comparison with the third friction force, comes into play and holds the movable element. This faulty function can thus be recognized without the function of holding the movable element being jeopardized overall. It is merely an indication that the safety margin S has been enlisted. The safety of the brake device is thus increased and servicing can be initiated.
[0059] A further possibly faulty function consists in that the brake device erroneously fails to release, i.e. the first, second and third friction contacts remain in place during travel operation. This faulty function can result from, for example, a defect in brake control units. This faulty function can also be recognized if the sensor device detects that the relative element is not disposed in its normal position, because, as described in the foregoing, in such a case the movable element entrains the relative element in the first degree of freedom, whereby this is shifted from its normal position to its braking position. A travel operation can be stopped, for example in the case of occurrence of a faulty function of that kind, before the corresponding contact surfaces overheat or have worn or suffered other damage.
[0060] In this connection it is particularly advantageous if a functional capability of the brake device and a sufficient safety margin for every normal operating play of the brake device can be ascertained. This significantly increases the operational safety of the brake device.
[0061] As a rule a brake device of that kind is delivered with new installations, advantageously directly together with a corresponding drive unit. Equally, a corresponding brake device can also be used in existing plants and elevator installations as a replacement for an existing brake device. Increased safety can thereby be achieved particularly in conjunction with a possible modernisation of a drive regulation system. An appropriate modernization kit adapted to known elevator installations can be provided.
DESCRIPTION OF THE DRAWINGS
[0062] Further objects, features and advantages of the present invention are evident from the subclaims and the following described exemplifying embodiments, for which purpose in partial schematic illustration:
[0063] FIG. 1 a shows a brake device according to a first embodiment of the present invention in released state, in a section I-I in FIG. 1 b;
[0064] FIG. 1 b shows the brake device according to FIG. 1 a in a lateral section;
[0065] FIGS. 2 a , 2 b show the brake device according to FIG. 1 in a normal holding state;
[0066] FIGS. 3 a , 3 b show the brake device according to FIG. 1 in a case of a faulty function, with monitoring logic system;
[0067] FIG. 4 shows a brake device according to a second embodiment of the present invention in opened state, in a lateral section;
[0068] FIG. 5 shows the brake device according to FIG. 4 in a normal holding state;
[0069] FIG. 6 shows the brake device according to FIG. 4 in the case of a faulty function;
[0070] FIG. 7 shows a schematic diagram of a third embodiment of the present invention;
[0071] FIGS. 8 a , 8 b show the brake device according to FIG. 1 with brake discs in series;
[0072] FIG. 9 shows an elevator drive with attached brake device;
[0073] FIG. 10 shows an elevator drive with brake device attached on either side of a traction wheel;
[0074] FIG. 11 shows an alternative embodiment of an elevator drive;
[0075] FIG. 12 shows a detail of brake arrangement in a drive according to FIG. 11 ; and
[0076] FIG. 13 shows an example of an elevator installation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0077] The same reference numerals are used in the figures for equivalent functions.
[0078] FIGS. 1 a , 1 b show a brake device such as is usable for an elevator drive, according to an embodiment of the present invention, in released, non-braking state in a side view and a front view, respectively. The brake device comprises a static element in the form of a multi-part housing 1 which is fixed in terms of inertia. A movable element in the form of an operating shaft 2 is rotatably mounted in the housing 1 and has the degree of rotational freedom φ relative to the housing 1 . Two brake elements in the form of brake discs 5 are arranged on the shaft to be axially displaceable, but secure against relative rotation, for example by means of shaft splines or a key (not illustrated).
[0079] Two actuating elements in the form of armature discs 4 are mounted in the housing 1 to be axially displaceable, but secure against relative rotation. For this purpose distributed over the circumference are three pins 9 which engage in through bores or blind bores in the housing 1 and the armature discs 4 and on which the armature discs 4 slide.
[0080] A relative element in the form of a disc 3 is mounted between each brake disc 5 and armature disc 4 to be axially displaceable. The discs 3 each have three groove-like cut-outs 10 with a groove base through which the pins 9 engage in such a manner that they rest on the respective groove base and thus rotatably mount the discs 3 . A rotation of the discs 3 is mechanically positively limited by the flanks of the grooves 10 , wherein the discs can be rotated through a specific angle before the pins 9 bear against the respective flanks. The discs 3 are biased into their normal position A, which is shown in FIGS. 1 a and 2 a and which is detected by a sensor device 8 , by two springs which are received in the housing 1 and internally supported at the flanks 10 , which are prolonged relative thereto (at the top in FIG. 1 a ).
[0081] FIGS. 1 a , 1 b show the brake device in released state. For this purpose electromagnets draw the armature discs 4 against the pressure of a compression spring 7 away from the brake discs 5 , which can thereby rotate freely together with the operating shaft 2 . In this state the relative elements 3 are kept by the above-mentioned springs in their normal position, which indicates fault-free operation.
[0082] FIGS. 2 a , 2 b show the brake device in applied state. For this purpose the electromagnets are no longer supplied with energy, so that the armature discs 4 are acted by way of the spring 7 by a normal force FN in the direction of a second, axial degree of freedom y. The armature discs 4 press, by the same normal force, the relative elements 3 against the brake discs 5 , which are thereby axially displaced and pressed by the same normal force against the housing 1 .
[0083] Through this normal force FN a first frictional contact forms in a first contact surface 6 . 1 between housing 1 and brake disc 5 , a second frictional contact forms in a second contact surface 6 . 2 between brake disc 5 and relative element 3 and a third frictional contact forms in a third contact surface 6 . 3 between relative element 3 and armature disc 4 . As a result, a sliding friction prevails at the outset in the first and second frictional contact due to the rotating operating shaft 2 , so that a first or second friction force (or a friction torque) FRi G =μi G− ×FN (i=1, 2). In that case, μi G− denotes the coefficient of sliding friction in the first or second frictional contact.
[0084] Static friction initially prevails in the third frictional contact, since relative element 3 and armature disc 4 are at rest relative to one another. The maximum effective third friction force FR 3 max is thus given by FR 3 max H =μ 3 H ×FN, wherein μ 3 H indicates the coefficient of static friction in the third frictional contact. This is selected so that the maximum third static friction force is greater than the second sliding friction force:
[0000] μ3 H >μ2 G (5)
[0000] μ3 H ×FN>μ 2 G ×FN (5′)
[0000] FR3max H >FR2 G (5″)
[0085] The relative element 3 is held in its normal position A by the adhesive force margin (FR 3 max H −FR 2 G ), whilst the brake disc 5 slides thereat. When the operating shaft 2 finally stops ( FIG. 2 a ), then the first and second frictional contact also change from sliding friction to static friction. Since the coefficients of static friction μ 1 H =μ 2 H >>μ3 H are selected, the maximum second friction force FR 2 max is now greater than the maximum third friction force FR 3 max. In this connection it is to be noted that for the sake of simplicity there is mention in each instance only of a coefficient of friction μi H , μi G . In reality each of these coefficients of friction is subject to a margin of error or a tolerance. By way of example, the definition μ 3 H >μ 2 G is thus to be understood in the sense that the value of μ 3 H , regardless of its tolerance position, is greater than the value of μ 2 G , regardless of the tolerance position thereof. The tolerance limits are therefore preferably selected so that the explained equations are also applicable to friction forces or coefficients of friction lying at the tolerance limits so as to be able to ensure functionality in accordance with the invention even in the case of scatters, which arise in practice, within the tolerances.
[0086] A possible faulty function of the brake device consists in that the brake device erroneously does not release when the operating shaft is placed back in operation. In this case the operating shaft 2 exerts by way of the brake disc 5 , starting from the holding position described in the foregoing with respect to FIG. 2 a , a force on the still-formed first, second and third frictional contacts. Since the maximum third friction force is at its smallest due to the selection of the coefficients of friction μ 1 H =μ 2 h >>μ 3 H the third frictional contact initially changes from static friction to sliding friction and the relative element 3 begins to rotate relative to the armature disc 4 . In that case the relative element rotates into the braking position B which is shown in FIGS. 3 a , 3 b and is detected by the sensor device 8 . This thereupon delivers status information to a monitoring logic system 11 . The monitoring logic system 11 evaluates the signal of the sensor device 8 with use of further signals such as, for example, movement or speed state of the travel body or of the movable element 2 and/or a braking signal which indicates whether the brake is applied or released, and issues a possible item of fault information to an elevator control (not illustrated), which stops the drive of the operating shaft 2 and thus prevents red-hot heating of the brake discs 5 and triggering of a corresponding service communication.
[0087] A further possible faulty function of the brake device consists in that the holding force applied by the brake device is insufficient. Again, starting from the holding position described with respect to FIG. 2 a the braking force FRmax maximally applied in the normal position A by the brake device is in the case of the embodiment of two brake discs
[0000] FR max=2×(μ1 H +μ3 H )× FN (6)
[0088] As stated in the foregoing, on the basis of the degree of rotational freedom φ use can in that case also be made in the equations of torques instead of translational forces. If the friction forces are insufficient, the operating shaft 2 begins to rotate. Since the maximum third friction force is at its smallest due to the selection of the coefficients of friction μ 1 H =μ 2 H >>μ 3 H the third frictional contact then changes from static friction to sliding friction, whilst static friction continues to be present in the second frictional contact. The relative element 3 begins to rotate relative to the armature disc 4 . In that case the relative element again rotates into the braking position B, which is shown in FIGS. 3 a , 3 b and detected by the sensor device 8 . This thereupon issues a faulty-function report as described in the foregoing, for example by way of a monitoring logic system, to an elevator control (not illustrated).
[0089] In the braking position B ( FIG. 3 a ) the mechanically positive couple between pin 9 and the flanks of the cut-out 10 prevent further rotation of the relative element 3 , this thereby being fixed in the first degree of freedom y relative to the housing 1 . The relative element 3 thus now transmits the greater second static friction force to the brake disc 5 and the entire braking force consequently increases to
[0000] FR+2×(μ1 H +μ2 H )×FN (6′)
[0090] Since the brake device is designed so that in the normal case the friction force, which is available in the first and third frictional contacts, according to Equation (6) is sufficient for holding the operating shaft 2 , a safety margin of (μ 1 H +μ 2 H )/(μ 1 H +μ 3 H ) is thus given.
[0091] FIG. 4 shows a brake device according to a second embodiment in released state in a lateral section. This brake device is provided for an elevator installation in which the brake device 24 . 1 , 24 . 2 is installed at a brake disc of an elevator drive, as illustrated in FIGS. 11 and 12 , or in which the housing 1 —which can be fastened to an elevator car 16 similarly to the illustration in FIG. 13 —moves in a first degree of freedom x along a brake rail 2 , 15 .
[0092] When the brake device is released ( FIG. 4 ) an electromagnet draws an armature element 4 , against the bias of a compression spring 7 , in a second degree of freedom y into the housing 1 so that the housing 1 can slide free of friction along the brake rail.
[0093] For braking the elevator car 16 , the electromagnet (or another suitable release drive) is switched off ( FIG. 5 ) and the compression spring 7 presses the armature element 4 in the second degree of freedom y by a normal force FN against a relative element 3 , which is arranged in the armature element 4 to be displaceable along the first degree of freedom x and is held by compression springs on either side in a normal position A ( FIGS. 4 , 5 ). The relative element 3 is thereby also pressed by the normal force FN against the brake rail 2 , 15 , which in turn is pressed against the housing 1 . In that case a first frictional contact is formed in a first contact surface 6 . 1 , in which the brake rail 2 is pressed against the housing 1 , a second frictional contact is formed in a second contact surface 6 . 2 , in which the relative element 3 contacts the brake rail 2 , and a third frictional contact is formed in a third contact surface 6 . 3 , in which armature element 4 and relative element 3 are in contact with one another. In that case, sliding friction is present in the first and second frictional contact due to the brake rail 2 moving relative to the housing 1 and static friction is present in the third frictional contact between the relative and armature elements 3 , 4 stationary relative to one another.
[0094] The coefficients of static friction μ 1 H =μ 2 H >>μ 3 H are selected as in the first exemplifying embodiment. Equally, the coefficients of sliding friction μ 1 G =μ 2 G in the first and second contact surfaces are smaller than the coefficient of static friction μ 3 H in the third contact surface. Since all contact surfaces are acted on by the same normal force FN, the sliding friction force in the first and second frictional contacts is lower than the maximum static frictional force in the third frictional contact:
[0000] μ1 G =μ2 G <μ3 H <μ1 H =μ2 H (7)
[0000] FR1 G =FR2 G <FR3max H (7′)
[0095] The brake rail 2 , 15 therefore slides in the first and second frictional contact, while the relative element 3 remains in its normal position A biased by the compression springs ( FIG. 5 ). At standstill, the first and second frictional contacts then also change from sliding friction to static friction and the total friction force by which the housing 1 holds the brake rail 2 is limited by the static friction in the first and second frictional contacts:
[0000] FR max=(μ1 H +μ3 H )× FN (6″)
[0096] As in the first exemplifying embodiment, a blocking brake device, which is not released notwithstanding movement of the housing 1 relative to the brake disc 2 , has the consequence—just like a too-small total friction force FRmax according to Equation (6″)—of entraining of the relative element 3 by the brake rail 2 in the first degree of freedom x until this is stopped at an upper abutment in the armature element 4 (not illustrated). In that case a sensor 8 registers the transition of the relative element from the normal position A ( FIG. 5 ) to this braking position B ( FIG. 6 ) and issues a faulty-function report. As soon as the relative element is fixed by the abutment (not illustrated) in the first degree of freedom x relative to the armature element 4 the second friction force FR 2 in the second contact surface 6 . 2 opposes the movement and the total friction force increases from FR=(μ 1 +μ 3 )×FN to FR=(μ 1 +μ 2 )×FN.
[0097] In the first and second exemplifying embodiments the maximum second and third friction forces were respectively realized by appropriate selection of the coefficients of friction μ 2 , μ 3 , particularly the coefficients of static friction μ 2 H , μ 3 H . Alternatively or additionally, the different maximum friction forces can, however, also be realized in that the third contact surface 6 . 3 is inclined relative to the normal force. For this purpose FIG. 7 shows, in a schematic diagram, the forces acting on a relative element 3 in the case of loading by the common normal force FN. The principle shown in FIG. 7 can be realized in, for example, the first or second exemplifying embodiment, wherein then the same reference numerals correspond with the same elements, the actuating element 4 in FIG. 7 thus corresponding with, for example, the armature disc in the first exemplifying embodiment or the armature element 4 in the second exemplifying embodiment.
[0098] It may be assumed at the outset that the held movable element 2 seeks to move under the influence of external forces, for example the load of an elevator car, in the first degree of freedom x in positive direction (upwardly in FIG. 7 ). On loading of the actuating element 4 by the normal force FN a friction force FR 2 , which is of the same size as, but opposite to, the sum of the remaining forces acting on the movable element 2 , but can be at most FR 2 max=μ 2 H ×FN, then arises in the second contact surface 6 . 2 .
[0099] The normal force FN acting in the third contact surface 6 . 3 , which is inclined by the angle (π−α) against the normal force FN, divides into two components, wherein one component FN×sin(α) is perpendicular to the third contact surface 6 . 3 and the other component FN×cos(α) is oriented tangentially to the third contact surface 6 . 3 . The third friction force maximally acting in the third contact surface 6 . 3 thus results from the one component to form FR 3 max=μ 3 H ×sin(α)×FN. Through suitable selection of the angle α of inclination it is thus possible, for example, to preset a lower maximum third friction force for the same coefficient of static friction. If this friction force is still projected in the third degree of freedom x, then a movement of the relative element 3 relative to the actuating element 4 in the first degree of freedom only still opposes at most a static friction force of FR 3 max=μ 3 H ×sin 2 (α)×FN.
[0100] As can be additionally seen from FIG. 7 , a movement of the relative element 3 relative to the actuating element in the first degree of freedom x in positive direction (upwardly in FIG. 7 ) additionally opposes a component FN×cos(α), which to that extent increases the total effect of maximum third friction force. In a case of movement in negative direction (downwardly in FIG. 7 ) this component FN×cos(α) thereagainst reduces the effective maximum third friction force, so that different maximum third friction forces arise in the two directions of movement. This can be advantageously utilized if, for example, the elevator car, which is held by the brake device, is only part-balanced, i.e. the movable element 2 has to be held more strongly in one direction of movement than in the other.
[0101] Moreover, on displacement of the relative element 3 relative to the actuating element 4 a change in adjustment travel along the degree of freedom y necessarily results. This change produces an increase or decrease in the normal force FN in correspondence with a force characteristic of adjusting actuators such as, for example, the compression spring 7 ( FIGS. 4 to 6 ). A braking force can thus be influenced in correspondence with a movement direction or braking direction.
[0102] The exemplifying embodiments refer to matching the coefficients of sliding and static friction of the friction surfaces in order to be able to reliably detect a faulty function not only in the case of single holding, but also in the case of braking and subsequent holding. This is achieved in that the condition
[0000] μ2 G <μ3 H <μ2 H (7)
[0000] is fulfilled. This is not obligatory, since in many current cases of use a brake device is used in the normal case only for holding, for example an elevator car at standstill. Use of the brake device for braking is required merely in a fault case and thus even itself represents a fault situation. It is not required in these individual cases for the relative element 3 to remain in its normal position. It may quite well be displaced from its normal position into the braking position, whereby then the correspondingly higher braking force
[0000] FR=FR 1 +FR 2 (1′)
[0000] comes into play. This can be achieved in that the coefficients of friction μ 3 H , μ 3 G of the third contact surface are selected to the significantly smaller than the coefficients of friction μ 2 H , μ 2 G of the second contact surface:
[0000] μ3 G <μ3 H <<μ2 G <μ2 H (7′)
[0103] Combinations of the illustrated forms of embodiment are obviously possible. Thus, for example, several second and third contact surfaces can be combined to form a first contact surface, whereby the safety margin is additionally increased.
[0104] In a preferred variant of embodiment the brake device 24 . 1 , 24 . 2 is, as illustrated in FIGS. 9 and 10 , installed in or attached to a drive 20 of an elevator installation 18 (as is explained in the following with reference to FIG. 13 ). The drive 20 comprises one or more drive pulleys or traction wheels 22 which are integrated in or mounted on a drive shaft 2 . The drive shaft 2 is driven by a motor 21 and held at standstill or, in the case of need, braked by the brake device 24 . 1 , 24 . 2 . On occasion a translation means can be arranged between motor 21 and drive shaft 2 . The drive 20 thus also includes the brake device 24 . 1 , 24 . 2 which as a rule is divided into two substantially identical units. Each of the units is, in its braking position (B), by itself capable of stopping and fixing the moved travel body. According to a first form of embodiment of the drive ( FIG. 9 ) the two units are combined to form a single brake device and arranged at an end of the drive shaft. In this form of embodiment the drive shaft corresponds with the movable element 2 . This form of arrangement is economic, since the brake device can, for example, be pre-mounted as a complete unit.
[0105] In accordance with one form of embodiment of the drive 20 according to the invention ( FIG. 10 ) the two units of the brake device 24 . 1 , 24 . 2 are attached to the two ends of the drive shaft 2 . This means that the drive pulley 22 is arranged between the units of the brake device 24 . 1 , 24 . 2 . Thus, during braking a braking or holding moment is distributed from the drive pulley 22 to the two units. Significantly better distributions of force in the drive shaft 2 thereby result and a risk of failure of the brake device due to fracture of the drive shaft 2 is reduced.
[0106] In the ideal case the braking action between normal position and braking position is doubled. This is the case when the coefficient of friction μ 3 in the third contact surface is approximately zero. Through use of a brake arrangement with several brake devices 24 . 1 , 24 . 2 connected one behind the other such as illustrated in, for example, FIGS. 8 a and 8 b it is possible to influence the braking force amplification between normal position and braking position. If, for example, several brake discs 5 and relative elements 3 or static elements 1 are arranged one behind the other a desired braking amplification can be achieved by the design of the free-running travel of the individual relative or static elements. In the example according to FIGS. 8 a and 8 b three second contact surfaces 6 . 2 , which come into action only in the braking position, are arranged to form a first contact surface 6 . 1 . Thus, disregarding the friction force of the third contact surface 6 . 3 , a multiplication of the braking force arises on attainment of the braking position. An expert can determine desired combinations.
[0107] FIG. 11 and FIG. 12 show an alternative arrangement of an elevator drive 20 with brake devices. In this connection, several brake devices 24 . 1 , 24 . 2 , 24 . 3 , etc., such as described in FIGS. 4 to 6 are arranged to be distributed over a circumference of a brake disc 2 , which forms a unit with the drive shaft.
[0108] FIG. 13 shows an elevator installation 18 with elevator drive 20 arranged in the upper region of a travel shaft 12 . The elevator drive 20 drives the elevator car 16 by means of the traction wheel 22 via supporting and driving means 13 . The supporting and driving means 13 connects the elevator car 16 with a counterweight 17 , so that in correspondence with a drive direction of the elevator drive the car 16 moves upwards and the counterweight 17 downwards or, with changed rotational direction of the elevator drive, vice versa. If the elevator drive 20 is held by its brake devices 24 . 1 , 24 . 2 , car and counterweight 17 are also at a stop or at standstill. In the illustrated example, car 16 and counterweight 17 are connected with the supporting and driving means 13 by way of deflecting rollers 14 . The forces acting on the drive 20 are thus halved.
[0109] Alternatively, the drive 20 can also be arranged in place of one of the deflecting rollers 14 .
[0110] The two units of the brake device are attached to the two ends of the drive shaft 2 . This means that the drive pulley 22 is arranged between the units of the brake device 24 . 1 , 24 . 2 . During braking a braking or holding moment is thus distributed from the drive pulley 22 to the two units. Significantly better force distributions in the drive shaft 2 thus result and a risk of failure of the brake device due to a fracture of the drive shaft 2 is reduced.
[0111] If the individual units or devices of the brake arrangement, preferably units such as illustrated and explained in the variants of embodiment of FIG. 4 to FIG. 7 , are arranged directly at the elevator car it is advantageous to apportion the brake units to the two sides of the elevator car. The resulting braking and holding forces can thus be introduced halved into the corresponding brake rails or guide rails. If in corresponding manner the brake arrangement is divided up into, for example, four brake devices, advantageously two of the brake devices are arranged below the elevator car and the remaining two brake devices in the upper region of the elevator car. As a result, not only is the introduction of force into the brake rails or guide rails optimized, but the introduction of force into the elevator car itself is also optimized.
[0112] The expert will recognise further advantageous arrangements. Thus, for example, the expert can distribute the brake units to elevator car and counterweight, or to car and counterweight and deflecting rollers or drive pulleys. This enables a distribution of the braking and holding forces to different components or load zones. The functional reliability is thereby increased, since individual components are loaded only by part forces.
[0113] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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An elevator drive for driving and detaining an elevator car includes a traction wheel transmitting a driving or detaining force to an elevator car, a motor driving the traction wheel, a braking arrangement for detaining the traction wheel, and a drive shaft connecting the traction wheel, the motor and the braking arrangement. The braking arrangement contains at least two braking devices with the traction wheel arranged between to divide the braking torques transmitted by the traction wheel to the braking devices. Symmetrical division of the braking devices on either side of the traction wheel reduces by half the torque transmitted in the drive shaft. A risk of failure or breakage of the drive shaft is thereby significantly reduced and during a failure of the drive shaft, the braking function continues since the braking devices are distributed on both sides of the traction wheel.
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FIELD OF THE INVENTION
The invention relates to a method and device for dispersing a liquid substance by means of a jet of a gaseous and/or liquid substance.
DESCRIPTION OF THE PRIOR ART
A method is known from U.S. Pat. No. 3,672,970 for refining a molten carbon-containing metal, wherein the metal is allowed to flow freely from the upper part of a reactor and the freely falling flow of melt is dispersed in the reactor by means of oxidizing gas jets which are directed slantingly downwards towards each other and emerge from nozzles fitted around the freely flowing metal flow. The oxidizing gas jets disperse the metal flow into drops with a large surface area and a relatively small size.
To achieve a selective oxidation, it is important that the melt can be dispersed into very small drops. The smaller the melt drop, the smaller the concentration gradient of carbon. If the drop is too large, carbon the melt still be present in its center when all the carbon on the drop surface has oxidized, in which case the metal on the drop surface will begin to oxidize simultaneously, thereby causing losses. The smaller the obtained drops are, the more selective the oxidation is, i.e., all of the easier oxidizing component can be removed substantially completely from the melt without the poorer oxidizing components being substantially oxidized.
In this known method, a device is used wherein the melt is fed into the reactor through an oblong narrow slit, on both sides of which slantingly downward directed nozzles have been fitted.
In terms of drop formation it would naturally be advantageous to obtain a thickness as small as possible for the melt curtain fed through the slit. In this case the width of the slit determines the thickness of the melt curtain. An arbitrarily narrow width cannot, however, be selected for the slit, for no melt can be caused to flow through too narrow a slit, and even in a slightly wider slit the slightest congelation of melt will break the melt curtain. Such congelations are very easily produced in narrow slits in which the transfer of heat from the melt to the walls of the slit is effective and the temperature of the melt is only slightly above the solidification point. In a wider slit the congelation tendency of the melt is not as strong and a possible unevenness in the wall of the slit does not notably disturb the curtain formation. Thus, it can be noted concerning this known device that a melt curtain as thin and even as possible is desired to produce drops as small as possible by means of gas jets directed at the curtain, but that the evenness of the curtain suffers if an attempt is made to reduce the thickness of the curtain below a certain limit.
Owing to the relatively thick curtain, strong gas jets must be used for dispersing it, and a relatively expensive and complicated nozzle system is required for producing these jets. The nozzles must be placed close to the melt slit to disperse the melt curtain into drops before the melt curtain puckers up. This sets high requirements on the durability of the nozzle system. The gas jets must be equally strong on both sides of the melt curtain to produce an even dispersion. To control the dispersion by means of gas jets is thus very difficult. In the performed pilot tests it was, furthermore, noted that the strong gas jets used in this known method create strong back flows which fling melt drops upwards, even as far as the nozzles, thereby damaging them. This may be partly due to the fact that strong gas jets penetrate the melt, wherein the gas expands explosively and flings melt in all directions.
Finally, it can be noted concerning this known method and device that oxidizing gases must be used in great excess to disperse into drops the curtain which is thick and therefore difficult to disperse, and only part of this gas reacts with the carbon present in the melt.
GDR Pat. No. 91,902 describes a method and device for continuous puddling of copper matte by means of air, wherein molten copper matte is fed as a wide and thin layer along a slanted melt duct into a furnace so that air nozzles place under the melt duct can disperse into drops the melt flowing over the edge of the melt duct in the form of a film.
In this case, also, the aim is to create a melt film as thin as possible and easy to disperse into drops by means of air jets placed under the melt duct and directed towards the melt film. In pilot tests we have, however, noted that even in this method, allowances must be made in regard to the thinness of the melt film, if the purpose is to simultaneously create an uninterrupted and even film. Namely, it has been noted that the melt flow continues over the melt duct as a film substantially as thick as in the melt duct. If melt is fed into the duct as too thin a layer, it puckers up and may even partly solidify owing to heat losses, as in the previous case. A greater flow velocity would decrease the risk of puckering up, but even this possibility is limited because the flow velocity can be raised only by tilting the duct to a greater angle. Furthermore, the flow velocity decreases when the layer is reduced. To decrease the risk of puckering up, the duct should be as short as possible, in which case, for structural reasons, it could not be placed at a very great angle of inclination.
Also known are devices of the former type, wherein the melt curtain is produced by causing the melt to flow in the form of a jet into a feeding funnel with a square cross section and with a narrow feeding slit in its lower part. The melt jet is caused to hit the slanted wall of the funnel throat next to the slit to spread the jet over the entire length of the slit. The melt curtain emerging from the slit is, however, similar to that in the first case, and this device has the same disadvantages.
The object of the present invention is to eliminate the disadvantages of the known methods and devices and to provide a method and device for dispersing a liquid substance with a gaseous and/or liquid substance jet, whereby the obtained layer of the substance to be dispersed is thinner than before but still even and can therefore be easily dispersed into very small drops or particles.
SUMMARY OF THE INVENTION
The method according to the invention can be used for numerous purposes. The method according to the invention can thus be applied to, for example, jet puddling of ferrochromium, to converting of sulfide matte, and to refining of steel, etc.
The substance to be dispersed must be in a flowing form, and thus mainly liquids such as metal melts, and liquid dispersions such as various suspensions are involved. On the other hand, the dispersion of gases is usually no problem.
The dispersing substance must also be in a flowing form, and thus mainly gases such as oxygen, air, or water vapor, liquids such as water, and mixtures of a gas and a liquid such as air and water can be considered. It can naturally be thought that the dispersing substance could be a pulverous substance, if use were found for such an embodiment.
Thus, by the method according to the invention, various substances can be dispersed by means of, for example, air, e.g. various liquid substances can be dispersed into drops by means of, for example, some oxidizing gas or granulated by means of water, to mention a few examples.
The method according to the present invention deviates from the previously known ones in that according to this invention the substance to be dispersed is caused, in the dispersion space, to impinge against a deflecting surface to produce a thin layer, e.g., a melt film, from the substance to be dispersed. Owing to its thinness and evenness, this layer is easy to disperse into particles or drops with a very small and even size. The dispersing is carried out by means of a jet of the dispersing substance, as in the known methods.
Thus, a much more even and thinner film or layer than previously is obtained by the method according to the invention. It may be advisable to discuss the reasons for it.
In the method according to the invention the substance to be dispersed reaches, owing to gravity, a relatively high velocity before impinging against the deflecting surface. Alternatively, it can be thought that the substance to be dispersed is sprayed from an arbitrary direction, e.g., from below upwards against the deflecting surface, but even in this case the substance to be dispersed has enough kinetic energy when it impinges against the deflecting surface to create the said film or layer. It can thus be said that the kinetic energy is partially transformed, by means of the deflecting surface, into dispersing energy to create the said film or layer. Generally speaking, it could also be said that a greater velocity of the substance to be dispersed at the impinging moment produces a thinner film or layer and the drops, granules or particles produced are finer.
On the basis of this principle it is easy to understand why the previously known methods have been so disadvantageous and why by the method according to the invention it is possible to achieve a decisively better end result than previously.
In previously known methods the melt curtain has been produced by means of either a slit or a melt duct. If, however, the slit were as narrow as the film produced by the method according to the invention is thick, no melt would flow through the slit. The heat losses and the resistance of flow would be too great. Also, the melt flowing along the melt duct is exposed to great heat losses and the melt layer closest to the duct is slowed down considerably, factors which naturally increase the risks of solidification and puckering up. It has been noted that the films produced by means of a melt duct are not nearly as even and thin as those produced by the method according to the invention.
When applying the method according to the invention, the substance to be dispersed must, according to the above principle, be sprayed with sufficient force or caused to flow from high enough onto a slanted surface. Melt cannot be caused to flow from very high because at a certain point it begins to pucker up, but the highest practicable falling height is easy to determine experimentally for the involved substance to be dispersed. Likewise, a professional can easily determine the most suitable angle of inclination for the deflecting surface without any complicated tests.
The melt flow must also be caused to impinge against the deflecting surface close to its leaving edge to prevent the puckering up of the created film or layer. The shorter the distance over which the melt is in contact with the deflecting surface, the smaller the heat losses and the resistance of flow. In the method according to the invention these factors are not, however, in proportion to the length of the deflecting surface, as in the melt duct, but to the distance of the leaving edge of the melt duct from the impinging point, which can be selected independently of the length of the deflecting surface. Likewise, the width of the deflecting surface can be selected arbitrarily; preferably it is, however, of the width of the flow of the substance to be dispersed or slightly wider, for the sake of precision of aim.
The deflecting surface can be even or curved, preferably of the shape of, for example, a paraboloid.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross section of a schematic side view of the device adapted for carrying out the method according to the invention;
FIG. 2 shows detail A of FIG. 1 on an enlarged scale;
FIG. 3 is a detail view showing nozzles directed toward the sides of a flat tile.
FIG. 4 is a view similar to FIG. 3 showing a convex tile.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1 and 2, the reactor is indicated by 1, the top of the reactor by 2, and the product sink by 3. Above the top 2 in the front part reactor 1 there is a pouring tank 4, at the bottom of which is a perforated tile 5 which connects the pouring tank 4 to the inner part of the reactor 1. The flow of the substance to be dispersed flowing from the tile 5 is indicated by 6 and the fan-shaped melt film deflected and created by the inclined-surfaced dispersion tile 7 is indicated by 8. The nozzles for the dispersing substance, fitted below the dispersing tile 7 are indicated by 9 and the drop mist formed from the melt film 8 under their effect is indicated by 10. To deflect and direct this drop mist 10, there are guide gas nozzles 11 in the top 2 of the reactor 1 to direct the drops downwards towards the product sink 3, in which the melt and possible slag 12 accumulate. In addition, in the back part of the reactor top 2 there is an outlet 13 for the discharge gases.
The device described above can be used in the method according to the invention for puddling ferrochromium, for example. In such a case the puddling process is divided into the following stages:
After pouring and slag separation, the ferrochromium to be refined is transferred by means of a sink to the reactor 1 and poured at a suitable rate into the pouring tank 4, from which it is allowed to flow through the perforated tile 5 into the reactor 1.
The melt flow is spread into a film by directing it onto the slanted dispersion tile 7.
The ferrochromium film is dispersed into a mist of drops 10 by side blasting it with oxygen jets 9.
Sulfur-removing and slag-forming reagents, e.g., burned lime powder, can be injected into the reaction zone.
The spray of drops and the puddling reactions are further regulated by blasting air or oxygen into the reaction zone through the nozzles 11 in the reactor top 2.
The ferrochromium and slag 12 accumulate in the product sink 3, where the after-puddling and a possible reduction of the slag take place by means of, for example, chromium silicate. Also, chemicals can be injected into the product sink with a lancet.
During the puddling the product can be cooled with, for example, ferrochromium scrap.
The discharge gases are sucked out of the reactor through the outlet 13 and a venturi washer. The flying dust is recovered in the washer. The after-combustion of the produced CO gas can be carried out in the washing part of the reactor.
The refined ferrochromium is cast after the separation of the slag.
The success of ferrochromium puddling is above all dependent on the drop formation stage, i.e., on how effectively drops are formed at the dispersion moment and what size they are. This is explained briefly below:
When ferrochromium is puddled with oxygen, the following dominant reactions can take place: ##EQU1##
At lower temperatures, 1500°-1600° C, corresponding to the pouring temperature of ferrochromium (=initial temperature of puddling), reactions (2) and (3) prevail after reaction (6) has taken place, reaction (2) always before reaction (5), whereas at temperatures above 1700° C reactions (1) and (4) take place. In order that chromium be oxidized to as small as extent as possible, the temperature of the melt must be raised above 1700° C as rapidly as possible. At the drop formation moment the first reaction that takes place is the oxidation of the silicon of ferrochromium (6), which raises the temperature of the drops faster if the drops are smaller.
The ferrochromium to be refined must contain a normal amount of silicon; e.g., 2.0 % Si when burning raises the melt temperature by 420° C. The melt is dispersed into very small drops to obtain a large reaction surface advantageous for the refining, the reaction velocity of puddling being determined by the diffusion of oxygen into ferrochromium. Compared with, for example, the puddling of pig iron, the drop size is important in the removal of carbon from ferrochromium also for the reason that when the carbon content decreases below the critical value on a drop surface, the chromium on the drop surface begins to oxidize, while the carbon content in the drop center is still high. For example, at 1800° C, with a chromium content of 50 % and a pressure of 1 atm. this carbon content is 0.9 %.
To carry out the drop formation according to the above requirements, the physical stages involved in the method are described below:
The puckering point of the uninterrupted melt flow, which is dependent on the melt amount regulated mainly by adjusting the size of the opening 5 at the bottom of the pouring tanks and the melt level, determines the maximum distance of the slanted surface 7 required for the formation of the film 8.
The shape of the melt film 8 (plane-like, paraboloid, etc.) can be affected by the shape of the slanted surface 7 which can be a flat surface 7 as shown in FIG. 3 or a convex surface 17 as shown in FIG. 4. The size of the melt film 8 curving parabolically downwards and spreading even-surfaced from the tile 7 -- the device which has been found the simplest in practice -- can be affected not only by the distance of the tile 7 but also by its slant and width.
After having thinned out sufficiently at its edges, the melt film 8 splits into band-like parts and is further divided into drops mainly by the forces of surface tension. The size of the produced drops 10 is naturally affected by the degree of thinning of the melt film 8; the impinging point of the melt flow 6 against the slanted tile 7 has a considerable effect on this degree. The breaking up of the film 8 is made more effective by almost horizontal gas jets 9 emerging from dispersing nozzles, whereby very small melt drops 10 with a large surface area are obtained. The velocity of the produced gas-drop mixture determines the delay period and the turbulence of the mixture has an effect on the gas exchange close to the drop surface.
In order that as large a part as possible of the energy of the dispersing jets 9 be available for dispersing the melt into drops, the distance from the nozzles 9 to the film 8 should be short enough. It is noteworthy that most of the energy of a gas jet is spent in inelastic impinging between the gas and the melt, in accelerating the melt drops and the gas absorbed into the jet from outside, and in losses caused by the swelling of the gas, and only a rather small part is available for the formation of a new surface. Besides energy factors, it must be noted that when the goal is a certain drop size, a certain minimum gas velocity is also required. The third factor limiting the distance of the nozzles 9 from the melt film 8 is a continuous dilution of the gas jets by environmental gases, the amount of the latter in the jet increasing along with the distance.
The behavior of the gas-drop suspension after the dispersion point is affected by the masses and velocities of the melt and the gas jets. Considering the above, this is in practice determined by the gas jets. For this reason the drops easily hit the back wall of the reactor, close to the outlet 13, and there is the risk that they become flying dust. To prevent this, the suspension spray 10 is directed downwards by using gas jets aimed at it from the top of the reactor.
The invention is described in more detail with reference to examples, but is must be noted that it is very easy for a professional to determine the suitable parameters for each case by adjusting the feeding velocity and amount of the substance to be dispersed, the distance of the feeding point from the deflecting surface, the distance of the impinging point from the leaving edge of the deflecting surface, the slant and width of the deflecting surface, and the feeding pressure, rate and direction of the dispersing substance and by observing the evenness and width of the produced film, curtain or layer and the evenness and fineness of the produced cloud of drops, granules or particles. It is impossible to give examples of all these variables or even to determine their limits because they are dependent on the treatment circumstances, the substance to be dispersed, and the dispersing substance, all of which can vary within a very wide range.
It has been observed that the method according to the invention can be used when dispersing a melt into drops and when dispersing a pulverous concentrate with oxygen, air, and/or water vapor. There is no reason to assume that the method according to the invention would not be equally applicable to dividing liquid dispersions or to using liquids as the dispersing substance.
In this context the term "reactor" must be understood very widely. The reactor can be, for example, a granulation chamber or a corresponding treatment apparatus.
EXAMPLE 1
When molten ferrochromium was allowed to flow through a φ 15 mm opening from the height of 0.5 m at 17.4 t/h on the average onto a plane surface formed by a tile slanted at 45°, at a distance of 50 mm from the outer edge of its upper surface, at the velocity of 2.2 m/s, the width of the produced melt film was 0.35 m at a distance of 0.5 m from the deflecting surface. The total length of the uninterrupted film was 1 m. Calculating from these values, it can be noted that the film was very thin.
In the trials it was observed that the ratio between the length and the width of the film decreased when the slant of the deflecting surface increased. The size of the film increased when the falling height increased. There was a maximum height for the fall owing to the puckering up of the melt spray; if this height was surpassed, the film was momentarily broken.
The optimal impinging point against the deflecting surface for the substance to be dispersed was noted to be as close as possible to its outer edge. An increase of the distance shortened the melt film, and if a certain distance was surpassed, the formation of a melt film was totally prevented.
A reduction of the deflection surface improved film formation. It had to be at least the width of the falling melt spray. In practice, however, it was slightly wider to improve the precision of aim.
Mainly at the starting moment of the system, owing to the precision of aim, part of the melt could flow along the sides of the tile used as the deflecting surface without forming a film. To prevent this, the deflecting surface was provided with side walls. In such a case the part of the melt which hit the walls formed string-like strips of the edges of the film and the melt film was broken. This phenomenon excluded the use of a duct-formed structure as the deflecting surface. Instead, suitably directed gas jets 9a blowing at the sides of the tile as shown in FIGS. 3 and 4 were found to eliminate this problem.
EXAMPLE 2
Ferrochromiums with average carbon contents were produced with a reactor wherein the feeding and drop-forming apparatus was dimensioned as follows:
diameter of the opening of the pouring tank φ 32 mm
falling height from the opening to the dispersing tile 700 mm
slant of the tile 45° and its width 125 mm
impinging point of melt against the tile 50 mm from the tip of the tile
main nozzles, 15 of them, were at an angle of 5°
directed downwards, at a distance of 273 mm from the ferrochromium film, and at such a height that the length of the produced film was 196 mm
top nozzles, 15 of them, were at an angle of 5° towards the dispersion point at a distance of 781 mm from the center line of the drop spray. The distance between the impinging points was 736 mm.
The ferrochromium rate was regulated at 30 t/h by means of the surface level in the pouring tank. Slag-forming reagents were injected into the reaction zone by means of a nozzle which had been placed in the top of the reactor. The drop spray was directed at the product sink, wherefrom the product ferrochromium was cast after slag separation. The discharge gases were sucked out through a venturi washer.
__________________________________________________________________________Initial ferrochromium analysis/% amount temperatureCr Fe C Si S t ° C__________________________________________________________________________a) 53.5 36.2 7.3 2.5 0.035 18.0 1580b) 53.8 36.4 7.5 1.9 0.040 15.0 1590Burned lime injected a) 2700 kg b) 1275 kg__________________________________________________________________________
In case (a) a total of 2550 Nm 3 of oxygen was used and the nozzle pressure was 4 atm. overpressure.
In case (b) oxygen was blasted with eight main nozzles and eight top nozzles. The nozzles pressure was 10 atm. overpressure and the total oxygen amount 1800 Nm 3 . In addition, superheated water vapor, temperature 220° C, was blasted with seven main nozzles and seven top nozzles. The used water vapor amount was 1.2 t.
After puddling, the slag was purified with chromium silicate having the analysis Cr 38 %, Fe 18 %, Si 44 %. In case (a) the amount of chromium silicate used was 2340 kg and in case (b) 1210 kg.
______________________________________Final slag analysis amount Cr.sub.2 O.sub.3 FeO CaO SiO.sub.2 t______________________________________a) 7.7 2.5 41.3 38.5 6.3b) 11.5 3.4 34.7 40.4 3.7Product ferrochromium analysis amount Cr Fe C Si S ta) 53.2 44.2 1.2 1.3 0.02 15.4b) 56.0 40.3 2.6 0.8 0.02 13.8______________________________________
EXAMPLE 3
Crude iron was refined with a reactor wherein the feeding and drop forming apparatus was dimensioned as follows:
diameter of the pouring tank opening φ 25 mm
falling height from the opening to the dispersing tile 500 mm
slant of the tile 55° and its width 125 mm
impinging point of the melt against the tile 30 mm from the tip of the tile
main nozzles, 15 of them, were horizontal and at a distance of 180 mm from the crude iron film and at such a height that the length of the film produced was 160 mm
top nozzles, two of them, were directed towards the center line of the drop spray, at a distance of 500 mm. The distance between the impinging points was 1100 mm
Crude iron was poured into the reactor at the rate of 11.1 t/h. Burned lime powder and flying dust separated from the discharge gases were injected into the reaction zone, a total of 14 % of the fees amount during the refining. Oxygen was blasted with the main nozzles, and the nozzle pressure was 3.2 atm. overpressure. Air was blasted with the top nozzles, and the nozzle pressure was 1 atm. overpressure.
When the oxygen rate 652 Nm 3 /h and the air rate 1410 Nm 3 /h, the following result was obtained:
______________________________________C Si Mn P S/%______________________________________Crude iron 4.2 0.9 0.8 0.09 0.035Product 0.12 0.01 0.02 0.025 0.020______________________________________
In the following trials the dispersing tile was left out and the main nozzles were changed into three nozzles which were directed at the melt flow horizontally, at a distance of 100 m. A corresponding result of refining was not obtained until the oxygen rate was raised to 869 Nm 3 /h and the pressure in the nozzles was 5.7 atm. overpressure. Air was blasted from the top nozzles at the same rate, 1410 Nm 3 /h, as previously.
EXAMPLE 4
a. Ferrochromium was refined with a reactor wherein the feeding and drop formation apparatus was dimensioned as follows:
diameter of the pouring tank opening φ 22 mm
falling height from the opening to the dispersing tile 500 mm, the slant of the tile 45°, and its width 125 mm
impinging point of the melt against the tile at a distance of 30 mm from the tip of the tile
main nozzles, seven of them, were at 270 mm from the ferrochromium film and at such a height that the length of the produced film was 160 mm
top nozzles, two of them, were directed towards the center line of the drop spray, at 500 mm. The distance between the impinging points was 1100 mm.
Ferrochromium was poured into the reactor at 13 t/h. Burned lime powder was injected into the reaction zone in an amount of 7.5 % of the feed by means of a nozzle which had been placed next to the main nozzles. The oxygen pressure in the nozzles was 4.5 atm. overpressure.
b. A reference trial was performed with another type of reactor wherein the nozzles had been placed in a circle around the perforated tile.
diameter of the pouring tank opening φ 22 mm
nozzles, 12 of them, were directed towards the melt flow at an angle of 30°. The distance from the nozzles to the impinging point was 250 mm.
Ferrochromium was poured into the reactor at 13 t/h. Burned lime powder was injected into the reaction zone in an amount of 7.5 % of the feed. The oxygen pressure had to be raised to 25 atm. overpressure.
______________________________________Initial ferrochromium amount temperature______________________________________ Cr Fe C Si kg ° Ca) 62.2 27.2 8.1 1.6 1100 1610b) 61.6 27.5 8.0 1.7 1500 1580Oxygen rate a) from main nozzles 70 Nm.sup.3 /t and from top nozzles 29.5 Nm.sup.3 /tb) 98.5 Nm.sup.3 /t amountSlag Cr.sub.2 O.sub.3 FeO CaO SiO.sub.2 kga) 34.8 4.5 33.3 14.4 250b) 39.7 4.4 32.0 12.9 350Refined ferrochromium amount chromium yield______________________________________ Cr Fe C Si kg %a) 63.4 30.2 4.3 0.1 960 89.2b) 62.9 30.3 4.7 0.1 1280 87.2______________________________________
In case (a) the reaction occurred evenly and in a controlled manner, whereas in case (b) the reactions were at times explosive and the result of the refining less even.
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A melt is passed as a flow into a space wherein the melt flow impinges against a deflecting surface transforming the melt flow into a thin, evenly spreaded film which, upon meeting one or more jets of a dispersing gaseous or liquid substance, is effectively dispersed.
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GRANT INFORMATION
This invention was made with Government support under Grant No. 5 R 01 CA23263, awarded by the National Institutes of Health. The Government has certain rights in this invention.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 08/290,185, filed on Aug. 15, 1994, now U.S. Pat. No. 5,631,370 which is a continuation of 08/019,983, filed Feb. 17, 1993, now abandoned which is a continuation of U.S. patent application Ser. No. 07/953,753, filed Sep. 29, 1992, now abandoned which is a continuation of U.S. patent application Ser. No. 07/623,348, filed Dec. 7, 1990, now abandoned which is a continuation in part of U.S. patent application Ser. No. 495,341, filed Mar. 19, 1990, abandoned which is a divisional of U.S. patent application Ser. No. 278,652 (filed Dec. 5, 1988) (U.S. Pat. No. 4,931,559) which is a continuation of U.S. patent application Ser. No. 146,252, filed Jan. 20, 1998 (U.S. Pat. No. 4,916,224).
FIELD OF THE INVENTION
The present invention relates to a therapeutic method employing dideoxycarbocyclic nucleosides which exhibit antiviral activity.
BACKGROUND OF THE INVENTION
Despite intensive effort to discover drugs that may be of value in the systemic treatment of human immunodeficiency virus (HIV) infections, such infections have been singularly resistant to chemotherapy. The intracellular and intimate relation to nuclear metabolism of virus reproduction makes it difficult to destroy a virus without irreparable damage to the host cell.
The discovery of the antiviral activity of vidarabine (9-β-D-arabinoturanosyladenine monohydrate) has led to the preparation of a large number of synthetic nucleosides. To date, only one synthetic nucleoside, 3'-azido-3'-deoxythymidine has been approved for treating certain AIDS patients, but it is a palliative, not a cure. ##STR2##
Although AZT is specifically active against retroviruses, its use has led to side effects, including anemia, headache, confusion, anxiety, nausea and insomnia. The nucleoside analog, 2',3'-dideoxycytidine (DDC), exhibits an in vitro TI 50 of ca. 300 against HIV and may exhibit fewer side effects than AZT, but may also be eliminated more rapidly from the body. ##STR3##
The synthesis of adenine ("6-amino-purine") nucleoside analogs in which the pentose sugar has been replaced with tris(hydroxy)-substituted cyclopentyl residues has yielded compounds with substantial cytotoxic and antiviral activity. For example, the carbocyclic analog of vidarabine, cyclaridine, is highly active against HSV-2, but exhibits a low therapeutic index (TI 50 =10) against HIV in vitro. Likewise, the carbocyclic analog of AZT is inactive against HIV. Therefore, it is clear that the structure-activity relationships between the variously substituted carbocyclic nucleosides which have been prepared and tested remain ill-defined.
Thus, a substantial need exists for chemotherapeutic agents effective to protect mammalian cells against infection by viruses such as HSV-2, HIV, varicella-zoster, vaccinia, human cytomegalovirus (HCMV) and the like.
SUMMARY OF THE INVENTION
The present invention is directed to hydroxymethylcyclopentenyl-substituted purines and 8-aza-purines of the formula (I): ##STR4## wherein Z is H. OR' or N(R) 2 , Y is CH or N, and X is selected from the group consisting of H, N(R) 2 , SR, OR' and halogen, wherein R is H, lower(C 1 -C 4 )alkyl, aryl or mixtures thereof, wherein R' is H, (C 1 -C 4 )alkyl, aryl, CHO, (C 1 -C 16 )alkanoyl, or O═P(OH) 2 , and the pharmaceutically acceptable salts thereof. Preferably, X is Cl, OR', most preferably OH; or N(R) 2 , Y is CH, R is phenyl or H, and R' is H or acetyl. As used herein, the term "aryl" includes substituted and unsubstituted aralkyl (preferably ar(C 1 -C 4 )alkyl) moieties. Preferred aryl moieties include phenyl, tolyl, xylyl, anisyl, or phen(C 1 -C 4 )alkyl, e.g., benzyl or phenethyl. Certain of these compounds are effective antiviral and/or cytotoxic agents or are intermediates useful for the preparation thereof.
A given compound within the scope of the formula has two optically active centers, indicated by the symbol (*) in formula I, either of which can exhibit R, S or RS stereochemistry. Therefore, single resolved, optically active enantiomers and diasteriomers of the present compounds are preferred embodiments of the present invention, although partially resolved and racemic (±) mixtures are also within the scope of the invention. The four stereoisomers of the compound of formula I are depicted below: ##STR5## wherein X, Y, Z and R' are defined hereinabove. The stereoconfigurations are given using the cyclopent-2-en-4-yl-1-carbinol nomenclature.
Certain of the compounds of formula I may exist as a mixture of tautomeric forms and all such tautomers are included within the scope of the invention.
A preferred compound of the invention is the optically active enantiomer of the formula II: ##STR6## wherein X, Y, Z and R' are as defined above and the stereochemistry at the optically active centers is as depicted. A wedged line indicates a bond extending above the plane of the cyclopentenyl ring, while a dashed line indicates a bond extending below the plane of the cyclopentenyl ring.
Although generally compounds of formula I are not active against HSV-1, it is expected that some of them will exhibit specific antiviral activity against other viruses such as hepatitis, HSV-2, EBVF RSV, PRV, HCMV and/or HIV, as well as against other retroviruses, such as those believed to cause T-cell leukemia. Specifically, the racemic compound of formula I, wherein X is OH, Z is NH 2 , Y is CH and R' is H (14a), strongly inhibits HIV infectivity in vitro. The TI 50 of this compound varied with the infected cell line which was used to assay for anti-HIV activity, but generally fell between 200-400, and was determined to be as high as 667 in one assay. The acetate ester (R'═Ac) of 14a was also active against HIV, giving 28% inhibition at 6 μg/ml. Compound 14a is also active against HSV-1.
The fully resolved compound of formula II, wherein X is OH, Z is NH 2 , Y is CH and R' is H ((-)14a) is also highly active against HIV (1'R,4'S)-2-amino-1,9-dihydro-9- 4'-hydroxymethyl-2'-cyclopenten-1-yl!-6H-purin-6-one, or (1S, 4R)-4-(2-amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenylcarbinol!. Compounds of formula I wherein X is Cl or N(R) 2 , Y is CH, Z is NH, and R' is H (13a and 15a, respectively) are also active against HIV, as are compounds wherein X is Cl, NH 2 or SH, Y is CH, Z is H and R' is H (7a, 9a and 10a, respectively). Compounds 7a, 9a and 10a, as well as compounds of the formula I wherein Y═N, Z═NH 2 , X═Cl, NH 2 or OH and R' is H (16a, 18a and 17a), are cytotoxic to cultured P-388 leukemia cells. It is believed that the antiviral activity is due to an inhibitory effect on the ability of viruses to infect normal mammalian cells. The present invention is also directed to the intermediate compound of the formula (III): ##STR7## wherein Z is H or NH 2 , Z' is H or NH 2 , and X is halogen, preferably Cl, which is useful for the preparation of the purines of the invention. Preferably, Z is NH 2 , and Z' is H or both Z and Z' are NH 2 . However, the compounds where X═Cl Z═NH 2 and Z'═H or NH 2 are not active against HIV.
The (3-hydroxymethylcyclopentenyl)pyrimidine analog, 20a, is also within the scope of the present invention. Its synthesis from cyclopentene 2a is outlined in Scheme I, below. ##STR8##
In compounds 19a and 20a, R can be CH 3 or H. Thus, it is expected that certain of the compounds of the present invention will be useful against viral infections or virus-associated tumors, and the method of their use to inhibit viral infectivity or tumor growth in vitro or in vivo is also within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram summarizing the synthesis of the purines of the present invention.
FIG. 2 is a graphic depiction of cells exposed to 14a /control cells (%) plotted vs. concentration of 14a for both uninfected cells and cells infected with HIV.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 outlines the synthesis of preferred compounds of the invention from starting material 1a. The structural formulas and some of the properties of compounds 7a-18a are summarized on Table I, below.
TABLE I______________________________________A. 2',3'-Dideoxy-6-Substituted-Purines of Formula I, Z = HCompound No. X Y M.P. (° C.) Rf Yield (%)______________________________________ 7a Cl CH 108-110 0.35.sup.a 82 8a OH CH 248-250 (dec) 0.24.sup.b 45 9a NH.sub.2 CH 198-200 0.33.sup.b 8110a SH CH 263-265 (dec) 0.44.sup.b 7311a OH N 180-182 0.38.sup.b 4912a NH.sub.2 N 220-222 (dec) 0.45.sup.b 69______________________________________B. 2',3'-Dideoxy-2,6-Disubstituted-Purines of Formula I, Z = NH.sub.2Compound No. X Y M.P. (° C.) Rf.sup.b Yield (%)______________________________________13a Cl CH 145-147 0.64 8014a OH CH 254-256 (dec) 0.27 6115a NH.sub.2 CH 152-155 0.41 8016a Cl N 153-155 (dec) 0.69 8117a OH N 223-225 (dec) 0.40 8918a NH.sub.2 N 240-242 (dec) 0.52 83______________________________________ .sup.a CHCl.sub.3 :MeOH, 10:1. .sup.b CHCl.sub.3 :MeOH, 5:1.
These compounds are candidates for clinical trials in human patients infected with HIV and/or afflicted with AIDS or AIDS-related complex (ARC).
The synthesis of the hydroxymethylcyclopentenyl compounds of formula 7a-18a, from the versatile precursor, 1α-acetylamino-4α-acetoxymethylcyclopent-2-ene (1a) was accomplished as outlined in FIG. 1. Compound 1a was prepared as described in U.S. Pat. No. 4,138,562, the disclosure of which is incorporated by reference herein. Compound 2a was prepared from compound 1a by hydrolysis in the presence of a mild base, such as an alkaline earth metal hydroxide. To afford the pyrimidine compound 3a, Z═H, compound 2a was reacted with an excess of 5-amino-4,6-dichloropyrimidine in the presence of an amine base, such as a trialkylamine, in an alcoholic solvent. Also, 2-amino-4,6-dichloropyrimidine was reacted with compound 2a to yield compound 4a.
Para-chloroaniline was diazotized with acidic sodium nitrite and reacted with compound 4a to yield the chlorophenylazo intermediate 5a. Reduction of the azo intermediate 5a to yield 6a was accomplished with zinc and acetic acid. See Shealy and Clayton, J. Pharm. Sci., 62, 1433 (1973).
The 5-amino-6-chloro-4-pyrimidinyl intermediate 3a was converted to the 9-substituted-6-chloropurine 7a (Z═H) by ring closure with triethylorthoformate and subsequent mild acid hydrolysis to remove ethoxymethylidenes and formates formed during the reaction. In like manner, the 2,5-diamino-6-chloro-4-pyrimidinyl intermediate 6a was ring-closed to the corresponding 2-amino-6-chloro-9H-purin-9-yl compound 13a.
The 6-chloropurines 7a and 13a were converted to the corresponding 6-hydroxy purines 8a and 14a, respectively, with aqueous base, i.e., by refluxing them with an alkali metal hydroxide such as NaOH. Chloro compounds 7a, 13a and 16a were converted to the corresponding amino compounds 9a, 15a and 18a by reaction with liquid ammonia under pressure.
Mono- or di-substituted 6-amino compounds of formula I, wherein X is NR 2 and R═R═(lower)alkyl, phenyl or mixtures thereof with H, can be prepared by conventional methods for the conversion of halides to secondary or tertiary amines. For example, see I. T. Harrison et al., Compendium of Organic Synthetic Methods, Wiley-Interscience, NY (1971) at pages 250-252. The 6-chloro substituent in compounds 7a, 13a and 16a can be replaced with other halogen atoms by the use of various p-(halo)benzene diazonium chlorides in the conversion of 4a to 5a, or by conventional methods of halide-halide exchange.
These conversions are extensively described in the context of purine nucleoside synthesis in Nucleoside Analogs-Chemistry, Biology and Medical Applications, R. T. Walker et al., eds., Plenum Press, NY (1979) at pages 193-223, the disclosure of which is incorporated by reference herein.
Treatment of 7a with thiourea in refluxing alcohol, followed by alkaline hydrolysis afforded thiol 10a. See L. F. Fieser et al., Reagents for Organic Synthesis, John Wiley and Sons, Inc., NY (1967) at pages 1165-1167 and U.S. Pat. No. 4,383,114, the disclosures of which are incorporated by reference herein. Phenyl or alkylthio-derivatives can be prepared from the corresponding thiols by the procedure of U.S. Pat. No. 4,383,114 (Example 6).
Ring closure of 3a with acidic aqueous sodium nitrate followed by neutralization with aqueous base directly afforded the corresponding 7-hydroxy-3H-1,2,3-triazolo 4,5d!pyrimidin-3-yl compound 11a. Ring closure of 6a afforded the corresponding 5-amino-7-chloro-3H-1,2,3-triazo 4,5d!pyrimidin-3-yl compound 16a, which was hydrolyzed to the corresponding 7-hydroxy compound 17a with aqueous NaOH. Compound 3a was converted to the corresponding 7-amino compounds 12a by reaction with acidic sodium nitrite, followed by reaction of the crude product with liquid ammonia. Compounds of formula I, wherein Z is OH, X is NH 2 or OH, and Y is CH can be prepared from compounds 14a, 15a or by deamination of the 2-amino group with nitrous acid, employing the procedure used by Davoll to convert 2-aminoadenosine to isoguanosine. See J. Davoll, J. Amer. Chem. Soc., 73, 3174 (1951), the disclosure of which is incorporated by reference herein.
Compounds of formula I, wherein X is H, Z is NH 2 and Y is CH can be prepared from compounds 7a or 13a by dehalogenation with zinc/water J. R. Marshall et al., J. Chem. Soc., 1004 (1951)! or by photolysis in dry nitrogen-purged tetrahydrofuran containing 10% triethylamine in a Rayonet photochemical reactor (2537 Å) by the method of V. Nair et al., J. Org. Chem., 52, 1344 (1987).
Phosphate or alkanoyl esters of compounds of formula I can be prepared as disclosed in R. Vince (U.S. Pat. No. 4,383,114), the disclosure of which is incorporated by reference herein, employing selective protection of, e.g., the hydroxymethyl or 6-hydroxyl groups, as necessary. Pharmaceutically-acceptable acid salts of compounds 7a-18a can be prepared as described in U.S. Pat. No. 4,383,114, the disclosure of which is incorporated by reference herein.
The invention will be further described by reference to the following detailed examples wherein elemental analyses were performed by M-A-W Laboratories, Phoenix, Ariz. Melting points were determined on a Mel-Temp apparatus and are corrected. Nuclear magnetic resonance spectra were obtained on Jeol FX 90QFT or Nicollet NT300 spectrometers and were recorded in DMSO-D 6 . Chemical shifts are expressed ppm downfield from Me 4 Si. IR spectra were determined as KBr pellets with a Nicollet 50XC FT-IR spectrometer, and UV spectra were determined on a Beckmann DU-8 spectrophotometer. Mass spectra were obtained with an AEI Scientific Apparatus Limited MS-30 mass spectrometer. Thin layer chromatography (TLC) was performed on 0.25 mm layers of Merck silica gel 60F-254 and column chromatography on Merck 60 silica gel (230-400 mesh). All chemicals and solvents are reagent grade unless otherwise specified.
EXAMPLE 1
(±)-(1α,4α)-4- (5-Amino-6-chloro-4-pyrimidinyl)-amino!-2-cyclopentenylcarbinol (3a)
A mixture of 1a (3.0 g, 15 mmol) and aqueous barium hydroxide (0.5N, 300 ml) was refluxed overnight. After cooling, it was neutralized with dry ice. The precipitate was filtered out, and the aqueous solution was concentrated to dryness. The residue was extracted with absolute ethanol and concentrated again to yield 2a as a colorless syrup 1.6 g (14 mmol).
To this syrup, 5-amino-4,6-dichloropyrimidine (4.59 g, 28 mmol), triethylamine (4.2 g, 42 mmol), and n-butanol (50 ml) were added and the mixture was refluxed for 24 hr. The volatile solvents were removed, the residue was absorbed on silica gel (7 g), packed in a flash column (4.0×12 cm) and eluted with CHCl 3 --MeOH (20:1) to yield 2.69 g (74%) of compound 3a; mp 130-132° C. An analytical sample was obtained by recrystalization from ethyl acetate (EtOAc), mp 134-135° C., MS (30 ev, 200° C.); m/e 240 and 242. (M + and M + +2), 209 (M + -31), 144 (B + ); IR: 3600-2600 (OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 13 ClN 4 O) C,H,N.
EXAMPLE 2
(±)-(1α4α)-4- (2-Amino-6-chloro-4-pyrimidinyl)-amino!-2-cyclopentenylcarbinol (4a)
To 14 mmol of crude 2a, 2-amino-4,6-dichloropyrimidine (3.74 g, 22.8 mmol), triethylamine (15 ml) and n-butanol (75 ml) were added and the mixture was refluxed for 48 hr. The volatile solvents were removed, residue was treated with methanol to separate the undissolved byproduct (the double pyrimidine nucleoside). The methanol solution was absorbed on silica gel (8 g) packed into a column (4.0×14 cm) and eluted with CHCl 3 --MeOH (40:1) to yield 1.52 g (42%) of crude 4a. The product was recrystalized from ethyl acetate to yield 4a; mp 132-134° C., MS (30 ev, 200° C.); m/e 240 and 242 (M + and M + +2), 209 (M + -31), 144 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 13 ClN 4 O) C,H,N.
EXAMPLE 3
(±)-(1α, 4α)-4-{ 2-Amino-6-chloro-5-(4-chlorophenyl)-azo!4-pyrimidinyl!-amino}-2-cyclopentenylcarbinol (5a)
A cold diazonium salt solution was prepared from p-chloroaniline (1.47 g, 11.5 mmol) in 3N HCl (25 ml) and sodium nitrite (870 mg, 12.5 mmol) in water (10 ml). This solution was added to a mixture of 4a (2.40 g, 10 mmol), acetic acid (50 ml), water (50 ml) and sodium acetate trihydrate (20 g). The reaction mixture was stirred overnight at room temperature. The yellow precipitate was filtered and washed with cold water until neutral, then it was air-dried in the fumehood to yield 3.60 g (94%), of 5a, mp 229° C. (dec). The analytical sample was obtained from acetone-methanol (1:2), mp 241-243° C. (dec). MS (30 ev, 260° C.): m/e 378 and 380 (M + and M + +2), 282 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 16 H 16 Cl 2 N 6 O) C,H,N.
EXAMPLE 4
(±)-(1α,4α)-4- (2,5-Diamino-6-chloro-4-pyrimidinylamino!-2 cyclopentenylcarbinol (6a)
A mixture of 5a (379 mg, 1 mmol), zinc dust (0.65 g, 10 mmol), acetic acid (0.32 ml), water (15 ml) and ethanol (15 ml) was refluxed under nitrogen for 3 hr. The zinc was removed and the solvents were evaporated. The residue was absorbed on silica gel (2 g), packed into a column (2.0×18 cm), and eluted with CHCl 3 --MeOH (15:1). A pink syrup was obtained. Further purification from methanol-ether yielded 6a as pink crystals, 170 mg (66%), mp 168-170° C., MS (30 ev, 220° C.); m/e 255 and 257 (M + and M + +2), 224 (M + -31), 159 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 14 ClN 5 O) C,H,N.
EXAMPLE 5
(±)-(1α, 4α)-4-(6-chloro-9H-purin-9-yl) -2-cyclopentenylcarbinol (7a)
A mixture of 3a (1.30 g, 5.4 mmol), triethyl orthoformate (30 ml) and hydrochloric acid (12N, 0.50 ml) was stirred overnight at room temperature. The solvent was evaporated at 35° C. in vacuo. To the residue was added aqueous hydrochloric acid (0.5N, 30 ml) and the mixture was stirred for 1 hr. The mixture was neutralized to pH 7-8 with 1N sodium hydroxide and absorbed onto silica gel (8 g), packed in a column (4.0×8 cm), and eluted with CHCl 3 --MeOH (20:1) to yield white crystals of 7a, 1.12 g (82%). The crude product was recrystalized from ethyl acetate to yield 7a, mp 108-110° C., MS (30 ev, 200° C.); m/e 250 and 252 (M + and M + +2), 219 (M + -31), 154 (B + ); IR: 3600-2800 (OH), 1600 (C═C, C═N); Anal. (C 11 H 11 ClN 4 O) C,H,N.
EXAMPLE 6
(±)-(1α,4α)-4-(6-Hydroxy-9H-purin-9-yl)-2-cyclopentenylcarbinol (8a)
A mixture of 7a (251 mg, 1 mmol) and aqueous sodium hydroxide (0.2N, 10 ml) was refluxed for 3 hr. After cooling, the reaction mixture was adjusted to pH 5-6 with acetic acid. The reaction mixture was absorbed on silica gel (2 g) packed in a column (2.0×11 cm) and eluted with CHCl 3 --MeOH (10:1) to yield 105 mg (45%) of 8a. The crude white product was recrystalized from water-methanol (3:1) to yield 8a, mp 248-250° C. (dec), MS (30 ev, 300° C.); m/e 232 (M+), 214 (M + -18), 136 (B + ); IR; 3600-2600 (OH), 1680,1600 (C═O, C═C, C═N); Anal. (C 11 H 12 N 4 O 2 ) C,H,N.
EXAMPLE 7
(±)-(1α,4α) -4-(6-Amino-9H-purin-9-yl)-2-cyclopentenylcarbinol (9a)
Liquid ammonia was passed into a bomb containing a solution of 7a (250 mg, 1 mmol) in methanol (5 ml) at -80° C. The bomb was sealed and heated at 60° C. for 24 hr. Ammonia and methanol were evaporated and the residue was recrystalized from water to yield off-white crystals of 9a, 187 mg (81%), mp 198-200° C., MS (30 ev, 210° C.): m/e 231 (M + ), 213 (M + -18), 135 (B + ); IR: 3600-2600 (NH 2 , OH), 1700,1600 (C═C, C═N); Anal. (C 11 H 13 N 3 O) C,H,N.
EXAMPLE 8
(±)-(1α, 4α)-4-(6-Mercapto-9H-purin-9-yl) -2-cyclopentenylcarbinol (10a)
A mixture of 7a (125 mg, 0.5 mmol), thiourea (40 mg, 0.64 mmol) and n-propanol (5 ml) was refluxed for 2 hr. After cooling, the precipitate was isolated by filtration, washed with n-propanol, and dissolved in sodium hydroxide (1N, 5ml). The solution was adjusted to pH 5 with acetic acid. The crude 10a (90 mg, 73%) was isolated again, mp 260-262° C. (dec) and was recrystalized from N,N-dimethylformamide, to yield 10a, mp 263-265° C. (dec). MS (30 ev, 290° C.): m/e 248 (M + ), 230 (M + -18), 152 (B + ); IR: 3600-3200 (OH), 3100,2400 (SH), 1600 (C═C, C═N); Anal. (C 11 H 12 N 4 OS) C,H,N.
EXAMPLE 9
(±)-(1α,4α)-4-(7-Hydroxy-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl)-2-cyclopentenyl carbinol (11a)
To a cold solution of 3a (361 mg, 1.5 mmol) in hydrochloric acid (1N, 30 ml) was added sodium nitrite solution (120 mg, 1.7 mmol) in 3 ml of water. The reaction was monitored by starch-potassium iodide paper. The mixture concentrated at 40° C. to a volume of 2 ml and adjusted to pH 7 with aqueous sodium hydroxide. The mixture was absorbed on silica gel (2 g), packed in a column (2.0×13 cm) and eluted with CHCl 3 --MeOH (10:1). The crude 11a was recrystallized from water-methanol (3:1) to yield white crystals of 11a, 173 mg (49%) mp 180-182° C. MS (30 ev, 230° C.): m/e 233 (M + ), 203 (M + -30), 137 (B + ); IR: 3600-2600 (OH), 1740,1600 (C═O, C═C, C═N); Anal. (C 10 H 11 N 5 O 2 ) C,H,N.
EXAMPLE 10
(±)-1α,4α)-4-(7-Amino-3H-1,2,3-triazolo 4,5d!pyrimidin-3-yl)-2-cyclopentenyl carbinol (12a)
Sodium nitrite solution (828 mg, 12 mmol) in water (10 ml) was added dropwise to a cold solution of 3a (2.43 g, 10.1 mmol) in hydrochloric acid (0.5N, 40 ml). The reaction mixture was stirred at room temperature for 1 hr, then concentrated to a syrup. The syrup was dissolved in ethanol and transferred into a stainless steel bomb. Liquid ammonia was passed in, the bomb was sealed, and the reaction mixture was stirred at room temperature overnight. Ammonia was evaporated and the residue was chromatographed on silica gel (150 g) eluting with CH 2 Cl 2 --MeOH (10:1) to yield white crystals of 12a, 1.62 g (69%), mp 220-222° C. (dec). MS (30 ev, 220° C.): m/e 232 (M + ), 202 (M + -30), 136 (B + ); IR: 3600-2800 (NH 2 , OH), 1700,1600 (C═C, C═N); Anal. (C 10 H 12 N 6 O) C,H,N.
EXAMPLE 11
(±)-(1α,4α)-4-(2-Amino-6-chloro-9H-purin-9-yl)-2-cyclopentenyl carbinol (13a)
A mixture of 6a (1.41 g, 5.5 mmol) triethyl orthoformate (30 ml) and hydrochloric acid (12N, 1.40 ml) was stirred overnight. The suspension was dried in vacuo. Diluted hydrochloric acid (0.5N, 40 ml) was added and the mixture was reacted at room temperature for 1 hr. The mixture was neutralized to pH 8 with 1N sodium hydroxide and absorbed on silica gel (7.5 g) packed in a column (4.0×10 cm) and eluted by CHCl 3 --MeOH (20:1) to yield off-white crystals of 13a, 1.18 g (80%). The crude product was recrystalized from ethanol to yield 13a, mp 145-147° C. MS (30 ev, 220° C.): m/e 265 and 267 (M + and M + +2), 235 (M + -30), 169 (B + ); IR: 3600-2600 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 11 H 12 N 5 OCl a 3/4 H 2 ) C,H,N.
EXAMPLE 12
(±)-(1α,4α)-4-(2-Amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenyl carbinol (14a)
A mixture of 13a (266 mg, 1 mmol) and aqueous ;sodium hydroxide (0.33N) was refluxed for 5 hr., absorbed onto silica gel (2 g) packed in a column (2.0×7.5 cm) and eluted with CHCl 3 --MeOH (5:1). The crude product was recrystalized from methanol-water (1:4) to yield white crystals of 14a, 152 mg (61%), mp 254-256° C. (dec). MS (30 ev, 200° C.): m/e 247 (M + ), 217 (M + -30), 151 (B + ); IR: 3600-2600 (NH 2 , OH), 1700,1600 (C═O, C═C, C═N); Anal. (C 11 H 13 N 5 O 2 a 3/4 H 2 O) C,H,N.
EXAMPLE 13
(±)-(1α,4α)-4-(2,6-Diamino-9H-purin-9-yl)-2-cyclopentenylcarbinol (15a)
Liquid ammonia was passed into a solution of 13a (265 mg, 1 mmol) in methanol (10 ml) at -80° C. in a bomb. The bomb was sealed and heated at 75° C. for 48 hr. Ammonia and methanol were evaporated. The residue was absorbed on silica gel (2 g), packed in a column (2.0×10 cm) and eluted with CHCl 3 --MeOH (15:1). The crude product was recrystalized from ethanol to yield 196 mg (80%) of 15a, mp 152-155° C. MS (30 ev, 200° C.): m/e 246 (M + ), 229 (M + -17), 216 (M + -30), 150 (B + ); IR: 3600-3000 (NH 2 , OH), 1700,1650,1600 (C═O, C═C, C═N); Anal. (C 11 H 14 N 6 O) C,H,N.
EXAMPLE 14
(±)-(1α,4α)-4-(5-Amino-7-chloro-3H-1,2,3-triazolor 4,5d!pyrimidin-3-yl)-2-cyclopentenyl carbinol (16a).
To a cold solution of 6a (225 mg, 1 mmol) in acetic acid (1.5 ml) and water (2.5 ml) was added sodium nitrite (83 mg, 1.2 mmol) in water (2 ml). The reaction was monitored-by starch-potassium iodide paper. After stirring for 1 hr. at 0° C., the precipitate was filtered and washed with cold water, then dried over phosphorus pentoxide in vacuo to yield 16a as off-white crystals, 218 mg (81%). The crude 16a was recrystalized from methanol, mp 153-155° C. (dec). MS (30 ev, 220° C.): m/e 266 and 268 (M + and M + +2), 236 (M + -30), 170 (B + ); IR: 3600-3000 (NH 2 , OH), 1650,1600 (C═C, C═N); Anal. (C 10 H 11 ClN 6 O) C,H,N.
EXAMPLE 15
(±)-(1α4α)-4-(5-Amino-7-hydroxy-3H-1,2,3-triazolo 4,5-d!-pyrimidin-3-yl)-2-cyclopentenyl carbinol (17a)
A mixture of 16a (218 mg, 0.8 mmol) and aqueous sodium hydroxide (0.25N, 10 ml) was refluxed for 3 hr, then was adjusted to pH 3 with 6N hydrochloric acid. The gelatinious precipitate was filtered and washed with cold water. It was dried over phosphorous pentoxide in vacuo to yield 17a as an off-white solid, 181 mg (90%) mp 222-224° C. (dec). After recrystalization from water, the mp was 223-225° C. (dec). MS (20 ev, 300° C.): m/e 248 (M + ), 217 (M + -31), 152 (B + ); IR: 3600-3000 (NH 2 , OH), 1750,1600 (C═C, C═N); Anal. (C 10 H 12 N 6 O 2 .1/2 H 2 O) C,H,N.
EXAMPLE 16
(±)-(1α,4α)-4-(5,7-Diamino-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl)-2-cyclopentenyl carbinol (18a)
Compound 16a (267 mg, 1 mmol) was processed as described in Example 13, employing a reaction time of 60° C. for 20 hr. The residual mixture was absorbed on silica gel (2 g), packed in a column (2.0×10 cm) and eluted by CHCl 3 --MeOH (15:1) to yield 18a as white crystals, 204 mg (83%). The crude product was recrystalized from ethanol-water (2:1), to yield 18a of mp 240-242° C. (dec). MS (30 ev, 240° C.): m/e 247 (M + ), 229 (M + -18), 217 (M + -30), 151 (B + ); IR: 3600-3100 (NH 2 , OH), 1700,1650,1600 (C═O, C═C, C═N); Anal. (C 10 H 13 N 7 O H 2 O) C,H,N.
EXAMPLE 17
(±)-(1α,4α)-4-(3-Methoxy-2-methylacryloylureido)-2-cyclopentenyl carbinol (19a)
Isocyanate reagent was prepared from 3-methoxy-2-methylacryloyl chloride (1.00 g, bp 65-66° C./2.5 mm) in anhydrous benzene (10 ml) and freshly dried silver cyanate (2.6 g, 17 mmol, dried at 110° C., 2 hrs) by refluxing for 0.5 hr. The supernatant was added dropwise into a solution of 2a (from 1a, 0.8 g, 4 mmol) in N,N-dimethylformamide (10 ml) at -15° C. and the mixture was stirred for 1 hr, then stored at 4° C. overnight. The solvent was evaporated and the residue was absorbed on silica gel (3 g), packed in a column (2.0×16 cm) and eluted with CHCl 3 --MeOH (20:1) to yield white crystals of 19a, 605 mg, (60%), mp 147-149° C. MS (30 ev, 200° C.): m/e 254 (M + ), 239 (M + -15), 223 (M + -31), 158 (B + ); IR: 3600-2800 (NH 2 , OH), 1700,1650,1600 (C═O, C═C); Anal. (C 12 H 18 N 2 O 4 ) C,H,N.
EXAMPLE 18
(±)-(1α,4α)-4- 5-Methyl-2,4-(1H,3H)-pyrimidinedion-3-yl!-2-cyclopentenyl carbinol (20a)
A mixture of 19a (381 mg, 1.5 mmol), p-toluenesulfonic acid monohydrate (20 mg) and anhydrous N,N-dimethylformamide (2 ml) was stirred at 115° C. for 3 hr. The solvent was evaporated, the residue was absorbed on silica gel (3 g) packed in a column (2.0×14 cm) and eluted with CHCl 3 --MeOH (20:1) to yield 20a as off-white crystals, 206 mg (62%). The-product was recrystalized from absolute ethanol to yield 20a, mp 213-215° C. MS (30 ev, 250° C.): m/e 222 (M + ), 204 (M + -18), 191 (M + -31), 126 (B + ); IR: 3600-3300 (OH), 1700,1600 (C═O, C═C); Anal. (C 11 H 14 N 2 O 3 ) C,H,N.
EXAMPLE 19
Esterification of Compound 14a
(1α, 4α)-4-(2-Amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenyl Acetoxycarbinol
To a suspension of 14a (130 mg, 0.50 mmol) and 4-dimethylaminopyridine (5 mg, 0.04 mmol) in a mixture of acetonitrile (6 ml) and triethylamine (0.09 ml, 0.66 mmol) ivy was added acetic anhydride (0.06 ml, 0.6 mmole). The mixture was stirred at room temperature for 3 hr. Methanol (1 ml) was added to quench the reaction. The solution was concentrated and absorbed on silica gel (1.5 g), packed on a column (2.0×12 cm), and eluted with CHCl 3 --MeOH (20:1). The product fractions were collected and concentrated to yield a white solid. The solid product was washed with MeOH-AcOEt to yield 123 mg of the purified acetoxycarbinol (85%). Further purification from methanol afforded needle-like crystals, mp 237-239° C.; Anal. (C 13 H 15 N 5 O 3 ) C,H,N.
EXAMPLE 20
(1S,4R)-4-(2-Amino-6-hydroxy-9H-Purin-9-yl)-2-cyclopentenyl Carbinol ((-)14a)
The diamino analog, 15a, (100 mg) was dissolved in 3 ml of 0.05M KAPOK buffer (pH 7.4), at 50° C. The solution was cooled at 25° C. and 40 units of adenosine deaminase (Sigma, Type VI, calf intestinal mucosa) was added. After three days of incubation at room temperature, a precipitate formed and was removed by filtration to yield 18.2 mg of crude product. The filtrate was concentrated to 1.5 ml and refrigerated for 2 days. Additional solid (26.8 mg) was obtained by filtration. The two solid fractions were recrystalized from water to yield the pure product, mp 269-272° C.; α! D 24 -62.1 (c 0.3 MeOH).
EXAMPLE 21
(1R,4S)-4-(2-Amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenyl carbinol ((+)14a)
The filtrates from the preparation of the 1S,4R isomer were combined and evaporated to dryness. The unchanged diamino starting material was separated on a silica gel flash column using 10% methanol/chloroform. The diamino compound was dissolved in 0.05M KAPOK buffet, pH 7.4 (15 ml) and 800 units of adenosine deaminase was added. The solution was incubated for 96 hr at 37° C. TLC indicated some unreacted product remained. The solution was heated in boiling water for 3 min and filtered to remove denatured protein. Another 800 units of adenosine deaminase was added and the processes were repeated. The deproteinated solution was evaporated to dryness and the product was crystalized from water to yield a white solid; mp 265-270° C.; α! D 24 +61.1 (c 0.3 MeOH).
EXAMPLE 22
Cytotoxicity Assay
The ED 50 cytotoxicity concentrations determined for analogs 7a, 9a, 10a, 16a, and 17a in the P-388 mouse leukemia cell culture assay are given in Table II.
TABLE II______________________________________Inhibitory Concentrations of Carbocyclic Nucleosides for P-388Leukemia Cells in Cultures*Compound ED.sub.50, μg/ml______________________________________ 7a 12.0 9a 40.010a 3.016a 1.017a 4.5______________________________________ *Assay Technique: R. G. Almquist and R. Vince, J. Med. Chem., 16, 1396 (1973).
Therefore, all of the compounds listed on Table II are active against P-388 mouse leukemia.
EXAMPLE 23
Anti-HIV Assay
Compounds of formula I were screened for anti-HIV activity at the National Cancer Institute, Frederick Cancer Research Facility, Frederick, Md. (FCRF). The following are the current screening mode operational procedures utilized at FCRF. The protocol consists of 3 areas, (I) preparation of infected cells and distribution to the test plates, (II) preparation of drug dilution plates and distribution to the test plates, and (III) XTT assay procedure. See D. A. Scudiero et al., "A New Simplified Tetrazolium Assay for Cell Growth and Drug Sensitivity in Culture," Cancer Res., 48, 4827 (1988).
I. Infection and Distribution of Cells to Microtiter Trays
Cells to be infected (a normal lymphoblastoid cell line which expresses CD4) are placed in 50 ml conical centrifuge tubes and treated for 1 hr with 1-2 μg/ml of polybrene at 37° C. The cells are then pelleted for 8 at 1200 rpm. HIV virus, diluted 1:10 in media (RMP1-1640, 10% human serum or 15% fetal calf serum (FCS), with IL-2, for ATH8 cells only, and antibiotics) is added to provided an MOI of 0.001. Medium alone is added to virus-free control cells. Assuming an infectious virus titer of 10 -4 , an MOI of 0.001 represents 8 infectious virus particles per 10,000 cells. About 500,000 cells/tube are exposed to 400 μl of the virus dilution. The resultant mixture is incubated for 1 hr at 37° C. in Air-CO 2 . The infected or uninfected cells are diluted to give 1×10 -4 (with human serum or 2×10 -4 with fetal calf serum) cells/100 μl.
Infected or uninfected cells (100 μl) are distributed to appropriate wells of a 96 well, U-bottom, microtiter plate. Each compound dilution is tested in duplicate with infected cells. Uninfected cells are examined for drug sensitivity in a single well for each dilution of compound. Drug-free control cells, infected and uninfected, are run in triplicate. Wells B2 through G2 served as reagent controls and received medium only. The plates are incubated at 37° C. in Air-CO 2 until the drug is added.
II. Drug Dilution and Addition
Dilution plates (flat bottom 96 well, microtiter plates) are treated overnight with phosphate buffered saline (PBS) or media containing at least 1% FCS or 1% human serum (depending on the medium used in the test), beginning the day before assay. This "blocking" procedure is used to limit the adsorption of drug to the microtiter tray during the dilution process. The wells are filled completely with the blocking solution and allowed to stand at room temperature in a humidified chamber in a hood.
The dilution process is begun by first diluting the test compound 1:20. Blocked, dilution plates are prepared by flicking out the blocking solution and blotting dry on sterile gauze. All wells of each plate are then filled with 225 μl of the appropriate medium using a Cetus liquid handling system. Twenty-five microliters (25 μl) of each 1:20 diluted compound is then manually added to row A of a blocked and filled dilution plate. Four compounds, sufficient to supply two test plates, are added per dilution plate. The four compounds are then serially diluted ten-fold from row A through row H using the Cetus liquid handling system. The starting dilution of each compound in row A is, at this point, 1:200. The dilution plates are kept on ice until needed.
Using a multi-channel pipettor with 6 microtips, 100 μl of each drug dilution is transferred to the test plate which already contains 100 μl of medium plus cells. The final dilution, in the test plate, starts at 1:400 (wells B4 through G4). This dilution (to 0.25% DMSO) prevents the DMSO vehicle from interfering with cell growth. Drug-free, infected or uninfected cells (wells B3 through G3) and reagent controls (B2 through G2) receive medium alone. The final two compounds are then transferred from wells H7 through H12 to a second test plate using the same procedure. Test plates are incubated at 37° C. in Air-CO 2 for 7-14 days or until virus controls are lysed as determined macroscopically.
III. Quantitation of Viral
Cytopathocenicity and Drug Activity
A. Materials
1. A solution of 2,3-bis 2-methoxy-4-nitro-5-sulfophenyl!-5- (phenylamino) carbonyl!-2H-tetrazolium hydroxide. (XTT)--1 mg/ml solution in media without FCS. Store at 4° C. Prepare weekly.
2. Phenazine methosulfonate (PMS) stock solution--This can be prepared and maintained frozen until needed at -20° C. It should be made in PBS to a concentration of 15.3 mg/ml.
B. Microculture Tetrazolium Assay (MTA)
1. Preparation of XTT-PMS Solution--The XTT-PMS is prepared immediately prior to its addition to the wells of the culture dish. The stock PMS solution is diluted 1:100 (0.153 mg/ml). Diluted PMS is added to every ml of XTT required to give a final PMS concentration of 0.02 mM. A 50 μl aliquot of the XTT-PMS mixture is added to each of the appropriate wells, and the plate is incubated for four hours at 37° C. The plate lids are removed and replaced with adhesive plate sealers (Dynatech cat 001-010-3501). The sealed plate is shaken on a microculture plate mixer and the absorbance is determined at 450 nm.
IV. Results
FIG. 2 depicts a plot of the percentage of test cells over uninfected cells (%) for both infected and uninfected cells as a function of the increasing concentration of compound 14a.
The data plotted on FIG. 2 permit the calculation of an effective concentration (EC 50 ) with respect to infected cells of about 0.15 μg/ml, an inhibitory concentration (IC 50 ) with respect to normal cells of about 100 μg/ml, and a therapeutic index (TI 50 ) of about 667. An earlier assay carried out at the Southern Research Institute yielded a TI 50 of about 200 when MT-2 cells were cultured with H9/HTLV-IIIB.
The HIV inhibitory concentrations of compounds 7a, 9a, 10a, 13a, 14a, and 15a are given on Table III, below.
TABLE III______________________________________HIV Inhibitory Concentrations.sup.aCompound ED.sub.50 (μg/ml)______________________________________ 7a >10 9a 2.310a >1013a 0.4114a 0.1515a 2.9(-)14a 0.66______________________________________ .sup.a T2 host cells, except (-)14a, which was assayed in CEM cells, exhibiting an IC.sub.50 of 189.
Compound 14a was also found to be active against feline leukemia virus (ED 50 =1.9; FAIDS variant); murine leukemia virus (ED 50 =1.1; Cas-BR-M type) and simian AIDS virus (ED 50 =2.8; D/Washington type).
The invention comprises the biologically active compounds as disclosed or the pharmaceutically acceptable salts or esters thereof, together with a pharmaceutically acceptable carrier for administration in effective non-toxic dose form. Pharmaceutically acceptable salts may be salts of organic acids, such as acetic, lactic, malic or p-toluene sulphonic acid and the like as well as salts of pharmaceutically-acceptable mineral acids, such as hydrochloric or sulfuric acid and the like. Other salts may be prepared and then converted by conventional double decomposition methods into pharmaceutically-acceptable salts directly suitable for purposes of treatment of viral infections in mammals or for the prevention of viral contamination of physiological fluids such as blood or semen in vitro.
Pharmaceutically acceptable carriers are materials useful for the purpose of administering the present analogs and may be solid, liquid or gaseous materials, which are otherwise inert and medically acceptable and are compatible with the active ingredients. Thus, the present active compounds can be combined with the carrier and added to physiological fluids in vitro or administered in vivo parenterally, orally, used as a suppository or pessary, applied topically as an ointment, cream, aerosol, powder, or given as eye or nose drops, etc., depending upon whether the preparation is used for treatment of internal or external viral infections.
For internal viral infections, the compositions may be administered orally or parenterally at effective non-toxic antivirus dose levels of about 10 to 750 mg/kg/day of body weight given in one dose or several smaller doses throughout the day. For oral administration, fine powders or granules may contain diluting, dispersing and/or surface active agents and may be presented in water or in a syrup; in capsules in the dry state, or in a non-aqueous solution or suspension; in tablets or the like. Where desirable or necessary, flavoring, preserving, suspending, thickening, or emulsifying agents may be included. For parenteral administration, administration as drops, the compounds may be presented in aqueous solution in an effective, non-toxic dose in concentration of from about 0.1 to 10 percent w/v. The solutions may contain antioxidants, buffers and the like. Alternatively, for infections of external tissues, the compositions are preferably applied as a topical ointment or cream in concentration of about 0.1 to 10 percent w/v.
Projected Clinical Trial to Evaluate Ability of Compound 14a+AZT to Inhibit the Progression of HIV Infection
AZT administration can decrease mortality and the frequency of opportunistic infection in subjects with AIDS or AIDS-related complex. M. A. Fischl et al. New Engl. J. Med., 317, 185 (1987). Therefore, many persons who have been diagnosed HIV-positive are presently receiving daily doses of AZT. However, AZT is myelotoxic and its administration over a period of 2-3 years has recently been shown to either cause, or to fail to inhibit, a high incidence of the development of non-Hodgkins lymphoma. Therefore, the present study is designed to evaluate the ability of compound (-)14a to inhibit the course of HIV infection.
Patients and Methods
Sixty patients, thirty with HIV infection plus AIDS-related complex and thirty with early AIDS are selected and evaluated in accord with the criteria provided by M. A. Fischl et al., cited above. The two groups of thirty patients are matched into pairs. A capsule containing 100 mg of AZT or an indistinguishable capsule containing 50 mg AZT and 50 mg of (-)14a is administered orally every 4 hours throughout the 24-hour day, for 24 weeks. All of the ARC patients complete the entire study and 20 of the AIDS patients complete the study.
Results
Development of AIDS in ARC Patients
Four patients in the AZT group but none in the AZT+14(a) group develop opportunistic infections or Kaposi sarcoma. Of the four patients in whom AIDS develops: 1 has PCP, candida pneumonia and cerebral toxoplasmosis; 2 have PCP alone and 1 has non-Hodgkins lymphoma in the breast and Kaposi sarcoma in a lymph node. Three of the four patients die 8, 15 and 18 months after diagnosis.
Clinical Progression of AIDS
Nine of the AIDS patients treated with AZT alone die during the study while there is only one death in the population treated with (-)14a plus AZT. During the treatment period, two of fifteen patients who receive the combination regimen worsen while, of the survivors, five of six patients receiving AZT alone worsen. The criteria for response are those of M. A. Fischl et al., cited above.
Discussion
Oral (-)14a+AZT administered in a 1:1 weight ratio is superior to an equivalent amount of AZT in reducing mortality due to early AIDS and the progression of HIV infection in both ARC and early AIDS patients, for a period of up to 6 months. This study also validates the in vitro model used herein to establish the anti-HIV activity of members of this class of carbocyclic nucleosides.
The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.
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A therapeutic method is provided, employing an antiviral compound of the general formula: ##STR1## wherein Z is H, OR' or N(R) 2 , where n R' is H, (C 1 -C 4 )alkyl, aryl, CHO, (C 1 -C 16 )alkanoyl or O═P (OH) 2 , Y is CH or N, and X is selected from the group consisting of H, N(R) 2 , SR, OR' or halogen, wherein R is H, lower(C 1 -C 4 )alkyl, aryl or mixtures thereof, and the pharmaceutically acceptable salts thereof.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to the general field of brazing together two materials that present different thermomechanical properties.
[0002] More precisely, the invention applies to brazing together a metal piece and a piece made of ceramic material, e.g. based on silicon carbide (SiC) and/or carbon.
[0003] The piece made of ceramic material may be constituted by solid silicon carbide. It may also be constituted by a thermostructural composite, and in particular by a ceramic matrix composite (CMC) reinforced by silicon carbide or carbon fibers.
[0004] Thermostructural composite materials are characterized by mechanical properties that make them suitable for constituting structural parts, while also conserving these mechanical properties at high temperatures. They are constituted by fiber reinforcement densified by a matrix of refractory material that fills in the pores of the fiber reinforcement, at least in part. The choice of materials for the fibers and for the ceramic is typically made amongst carbon and ceramics (i.e. materials that are neither metallic nor organic), and in particular silicon carbide (SiC).
[0005] By way of example, the invention can be used for assembling together a piece made of ceramic material with a metal piece made of an alloy of titanium, aluminum, and vanadium (TA6V) or of Inconel 718 (registered trademark), an alloy based on nickel and having the composition NiCr19Fe19Nb5Mo3.
[0006] The mechanical properties of pieces made of ceramic material and the fact that these properties are conserved at high temperature make them materials that are particularly suitable for making pieces that are subjected to high levels of thermomechanical stress, in particular in aviation applications (engine parts, fairing elements). When ceramic materials are reinforced by silicon carbide or carbon fibers, they constitute an alternative to metallic materials, presenting numerous advantages, in particular in terms of weight savings and of operational lifetime.
[0007] Conventionally, pieces made of ceramic material and metal pieces are assembled together by a mechanical connection of the riveting or bolting type, but such a connection can sometimes be unsuitable for reasons of size, difficulty of implementation, or weight.
[0008] Furthermore, known homogeneous assembly methods for use with ceramic materials and involving organic precursors of ceramics are not suitable for heterogeneous assemblies between a ceramic material and a metal.
[0009] Known brazing techniques used for making homogeneous connections between two ceramic materials can be difficult to use for heterogeneously brazing a ceramic material on a metal because of the very different thermomechanical and chemical behaviors of ceramic materials and metals.
[0010] A metal alloy based on titanium, aluminum, and vanadium presents a coefficient of expansion that is about two to three times greater than that of ceramic materials.
[0011] More precisely, the coefficient of expansion of such an alloy at 500° C. is about 10×10 −6 K −1 ±15%, while the coefficient for a CMC is about 2.5×10 −6 K −1 to 4.0×10 −6 K −1 ±15%.
[0012] Thus, for a 30 millimeter (mm) assembly, an expansion offset of 0.2 mm is observed on cooling the assembly from the solidification temperature of the brazing composition to ambient temperature.
[0013] Such an offset leads to high levels of stress appearing in the two pieces, and in particular to compression forces in zones of the brazed joint adjacent to the ceramic, and traction forces in zones adjacent to the metal piece. These stresses can give rise to local deformations that might cause one of the pieces to break or lead to reduced strength of the brazed joint.
[0014] Such deformations are irreversible in the metal piece. In the ceramic piece, in particular when made of a CMC, these deformations can lead to brittle type breakage. Such breakage can occur suddenly if the stress is too high. Breakage can also occur by damage building up successively under cyclical stressing.
OBJECT AND SUMMARY OF THE INVENTION
[0015] A main object of the present invention is thus to mitigate such drawbacks by proposing an assembly comprising a metal piece, a piece made of ceramic material, and at least one intermediate connection element assembled to each of said pieces by brazing, the intermediate connection element being constituted by a deformable sheet presenting brazed flat zones and deformable zones.
[0016] By way of example, a brazing composition of the Ag—Mn or Ag—Cu—Ti type may be selected, thus making it possible to obtain an assembly that is strong at high temperatures of as much as 500° C.
[0017] In accordance with the invention, the differential expansion between the piece made of ceramic material and the metal piece is absorbed by the deformable sheet.
[0018] The assembly thus presents thermomechanical adaptation to differential expansion, while remaining as much as possible within the elastic domain. In order to be able to withstand cooling after brazing and thermal cycling in operation, it is necessary to accommodate the differential expansion between the piece made of ceramic material and the metal piece.
[0019] In a preferred embodiment, the piece made of ceramic material is based on silicon carbide and/or carbon.
[0020] For example, the ceramic material piece is made of solid silicon carbide.
[0021] In another embodiment, the ceramic material piece comprises a ceramic matrix reinforced by silicon carbide or carbon fibers.
[0022] In a preferred embodiment, the deformable sheet includes at least two deformable undulations oriented in alternation towards the metal piece and towards the piece made of ceramic material.
[0023] Preferably, at least one of the deformable undulations is free, such a free undulation guaranteeing increased flexibility for the brazed connection.
[0024] The height of the free undulation may advantageously be used for modifying rigidity in the fold direction.
[0025] In a first variant embodiment, the deformable undulations are concentric.
[0026] In an embodiment of this first variant, the intermediate connection element comprises a first flat zone that is substantially circular about an axis, a second flat zone that is substantially annular, coaxial about the first flat zone, and having an inside diameter greater than the diameter of said first zone, and undulations presenting symmetry of revolution about the above-mentioned axis.
[0027] Because of this symmetry, such a connection element presents behavior that is identical regardless of the direction of the line of greatest stress.
[0028] In another variant embodiment the connection element is generally in the form of a concertina-folded tape.
[0029] In an advantageous embodiment of the invention, the assembly comprises a plurality of intermediate connection elements that are disposed radially around a fixed point.
[0030] With such a connection element, the stresses are low in the brazed joints and rigidity can be modulated.
[0031] Placing the intermediate connection elements in a radial star disposition advantageously presents concentric undulations that are interrupted radially (the interruptions being constituted by empty gaps along a plurality of radial directions), thus making it possible to reduce or eliminate tangential stresses from such concentric circles.
[0032] Preferably, the intermediate connection elements are arranged in a plurality of radial directions around the fixed point.
[0033] Such an embodiment enables the stiffness of the assembly between the metal piece and the piece of ceramic material to be increased.
[0034] Around the fixed point as defined above, the offset due to the expansion of the metal piece increases with distance from the fixed point.
[0035] In a particular embodiment of this configuration, the intermediate connection elements are of increasing flexibility on going away from the fixed point.
[0036] Such an embodiment serves to compensate for the above-mentioned increase in offset.
[0037] The invention also provides a turbomachine nozzle including at least one assembly as mentioned above in which the metal piece is a casing of said nozzle (or a lever), and the piece made of ceramic material is a flap of the nozzle.
[0038] The invention also seeks to provide a turbomachine combustion chamber including at least one assembly as mentioned above in which the metal piece is a casing of said chamber (or a component part thereof, or a joint—i.e. a connection element—therein), and the piece made of ceramic material is a component part of said chamber.
[0039] The invention also provides post-combustion equipment for a turbomachine including at least one assembly as mentioned above in which the metal piece is a post-combustion casing (or a platform of post-combustion equipment), and the piece made of ceramic material is a flame-holder arm.
[0040] The invention also provides a turbomachine including at least one assembly as mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Other characteristics and advantages of the present invention appear from the following description with reference to the accompanying drawings that show embodiments having no limiting character. In the figures:
[0042] FIG. 1 shows a connection element suitable for use in a first assembly in accordance with the invention;
[0043] FIG. 2 is a section through an assembly of the invention using the connection piece of FIG. 1 ;
[0044] FIG. 3 shows a connection element suitable for use in a second assembly in accordance with the invention;
[0045] FIG. 4 shows a connection element suitable for use in a third assembly in accordance with the invention;
[0046] FIG. 5 is a fragmentary section through the connection element of FIGS. 3 and 4 ;
[0047] FIG. 6 shows an undulating surface from which intermediate connection elements of the kind shown in FIG. 5 are obtained;
[0048] FIG. 7 shows an advantageous embodiment of the invention;
[0049] FIG. 8 shows a particular embodiment of a piece having openings formed therein to facilitate positioning and anchoring connection elements for assembly in accordance with the invention; and
[0050] FIGS. 9A and 9B are curves showing mechanical properties as a function of temperature for materials suitable for use in making intermediate elements, respectively elements that are ductile and elements that are reversibly deformable.
DETAILED DESCRIPTION OF EMBODIMENTS
[0051] FIG. 1 shows a connection element 10 suitable for use in a first assembly in accordance with the invention. By way of example it is constituted by a plane deformable material stamped as to form a first flat zone 11 that is circular about an axis Δ, and a second flat zone 12 that is annular about the axis Δ, these two zones being interconnected by a deformable zone 13 forming substantially a truncated cone. The inside diameter of the annular zone 12 is greater than the diameter of the circular zone 11 . The substantially conical walls 13 may present inclination to a greater or lesser extent relative to the direction perpendicular to the flat zones 11 and 12 .
[0052] FIG. 2 shows a section II-II (see FIG. 1 ) through an assembly 14 of the invention made using a connection element 10 as shown in FIG. 1 .
[0053] In this assembly, a first brazed joint 15 is made between a metal piece 16 and the circular flat zone 11 of the connection element 10 . A second brazed joint 17 , preferably using the same brazing composition, is made between a piece 18 of ceramic material, e.g. a CMC, and the annular flat zone 12 of the connection element 10 .
[0054] The connection element 10 shown and used in FIGS. 1 and 2 , can be obtained from a plate of deformable material by cutting out and stamping using a substantially cylindrical stamping element.
[0055] A vertical height or size for the connection element of about 2 mm is appropriate for aviation applications, however it will be understood that this size can be modified as a function of requirements specific to different applications. The proportions of the various portions of the connection element 10 may also be modified as a function the intended application.
[0056] On this topic, it should be observed that modifying the geometrical parameters of the connection element 10 makes it possible to modify the magnitude of the stresses observed.
[0057] The proposed size of 2 mm enables flexibility to be obtained in the tangential direction for pieces having a size of the order of about ten centimeters. Under the effect of differential expansion, for example during a thermal cycle, the conical portion 13 of the connection element 10 can absorb this expansion differential completely, or in part, without endangering the strength of the assembly. Since the material from which the connection element is made is deformable, the deformation of the cylindrical portion is of no consequence for the assembly as a whole.
[0058] Nevertheless, in the embodiment shown in FIG. 2 , high levels of stress can be observed in the brazed joints and in shear in the membrane in the connection element.
[0059] The connection element 10 ′ described below with reference to FIG. 3 serves to mitigate this drawback.
[0060] The connection element 10 ′ has a deformable zone 13 ′ that is axially symmetrical about an axis Δ, this zone 13 ′ being shaped so as to comprise at least two free undulations 19 and 20 oriented alternately upwards and downwards relative to the flat zones 11 and 12 that are respectively circular and annular about the axis Δ. The structure is still advantageously made of stamped deformable material. The presence of undulations that are free, i.e. not brazed, in the deformable zone 13 ′ makes the structure more flexible.
[0061] FIG. 5 shows a section V-V (see FIG. 3 ) of the connection element 10 ′. The flat zones 11 and 12 are interconnected by the deformable zone 13 ′ that presents two free undulations 19 and 20 .
[0062] It should be observed that in FIGS. 3 and 5 , the undulations 19 and 20 are shown as being substantially flat, however they could equally well have other shapes, for example they could be sinusoidal.
[0063] Considerations of size, bulk, and proportion similar to those mentioned for the connection element shown in FIG. 1 apply likewise to the element of FIG. 3 .
[0064] It should be observed that changes in the thickness of the stamped sheet, radii of curvature r 1 , r 2 , r 3 , r 4 , r 5 , and r 6 of the undulations, dimensions l 1 , l 2 of the undulations, heights h 1 , h 2 , and h 3 characterizing the undulations 19 and 20 , angles alp 1 , alp 2 , and alp 3 between the undulations and the perpendicular to the flat zones, and sizes l 0 , l 3 of said flat zones are all to be envisaged and constitute as many parameters for refining the stresses and the stiffness properties of the element.
[0065] In the embodiments of FIGS. 1 and 3 , the rigidity of the resulting assembly in shear presents the advantage of being isotropic in the assembly plane.
[0066] The shear stresses observed at the brazed joints in an assembly using a connection element having the characteristics shown in FIG. 3 are smaller than those observed in an assembly using a connection element as shown in FIG. 1 .
[0067] FIG. 4 shows a connection element 10 ″ that can be used in another assembly in accordance with the invention. In this embodiment, the connection element 10 ″ is generally in the form of a concertina-folded tape. In the example shown in FIG. 4 , the section of the tape is the same as that shown in FIG. 5 . Such a connection element could also be a stamped structure or could advantageously be obtained by folding, or by extrusion in a straight line along the direction Y. If extruded, and as shown in FIG. 6 , an undulating surface 22 is obtained with corrugations that extend along the direction Y.
[0068] The connection elements 10 ″ are then cut once every L millimeters from said undulating surface 22 .
[0069] It is also possible to envisage machining a piece made of metal such as Inconel 718, e.g. by wire machining.
[0070] The intermediate element 10 ″ in this embodiment has a preferred direction for deformation constituted by the direction X (tangential rigidity) and a rigid direction constituted by the direction Y (transverse rigidity).
[0071] The stresses observed in the brazed joints in this embodiment are low. The resulting assembly then presents lower rigidity than that observed in the other embodiments based on an axially symmetrical connection element 10 or 10 ′, as shown in FIGS. 1 and 3 .
[0072] The geometrical parameters of the tape can be modified in order to obtain the lowest maximum stress in the brazed joints and in the structure itself for the lowest tangential rigidity (i.e. in the direction X), and the highest normal rigidity (in the direction Z).
[0073] Thus, it is possible to modify the thickness e of the tape, the radii of curvature r 1 , r 2 , r 3 , r 4 , r 5 , and r 6 of the undulations, the dimensions l 1 , l 2 of the undulations, the heights h 1 , h 2 , and h 3 of the undulations, the angles alp 1 , alp 2 , and alp 3 made by the undulations relative to the perpendicular to the flat zones, and the dimensions l 0 , l 3 of the flat zones.
[0074] The three heights h 1 , h 2 , h 3 characterize the two free undulations 19 and 20 of the deformable zone 13 ′. These first, second, and third heights h 1 , h 2 , h 3 correspond, as shown in FIG. 5 , to the heights of the portions of the tape that are substantially rectilinear in profile extending respectively between the first flat zone 11 and the bottom of the undulation 19 , between the bottom of the undulation 19 and the top of the undulation 20 , and between the top of the undulation 20 and the second flat zone 12 .
[0075] The person skilled in the art will understand that the height h 2 is selected to be less than or equal to the height h 1 .
[0076] Nevertheless, it is advantageous also to take account of the minimum radii of curvature for the free undulations. The value of h 2 is then advantageously selected to be greater than or equal to ⅓ of h 1 .
[0077] In the example described herein, the values that have been selected and that are proposed are limited to a few tenths of a millimeter since it is required that the connection between the assembled pieces should not exceed 2 mm. That said, the greater h 1 and h 2 , the more the deformations are spread and the lower the stresses.
[0078] The table below shows an example of a set of geometrical parameters suitable for obtaining a good compromise between maximum stress and rigidity with an alloy tape made of Inconel 718™.
[0000]
e
h1
h2
h3
alp1-alp3
l1-l3
r1-r6
l0
0.4 mm
0.3 mm
0.1 mm
0.3 mm
5°
0.5 mm
0.75 mm
1.0 mm
[0079] To increase rigidity in shear parallel to the assembly plane, a plurality of intermediate connection elements 10 ′ are disposed radially around a fixed point 23 , as shown in FIG. 7 .
[0080] In this embodiment, the deformable sheets are directed towards the fixed point 23 . By placing the connection elements 10 ″ in concentric manner, zero relative displacement is forced between the assembled pieces for the central point 23 of the concentric arrangement. This stiffens the assembly in the assembly plane. The intermediate elements 10 ″ can be placed in such a manner that their own deformation directions point towards the fixed point 23 .
[0081] This disposition mitigates the lack of rigidity in the tangential direction. Relative deformation during cooling of the two pieces to be assembled together is then oriented towards the center of the assembly, which is the fixed point 23 , so there is no relative movement between the two pieces that are to be assembled. The deformation due to differential expansion is then absorbed concentrically. Overall rigidity is obtained because of the greater rigidity of the structures in the direction perpendicular to the preferred deformation direction.
[0082] In addition, given that the relative displacement between the pieces for assembly is zero at the fixed point and that it increases out to the periphery, it is advantageous to make use of structures of increasingly flexibility on going away from the fixed point. This serves to improve tangential rigidity in the region of the fixed point.
[0083] FIG. 8 shows a particular embodiment of an assembly piece 30 having openings or cavities 31 formed therein for the purpose of positioning intermediate connection elements 10 ″ in a star configuration corresponding to that shown in FIG. 7 . This arrangement enables the intermediate connection elements 10 ″ to be anchored in the piece 30 which is preferably the metal piece, or possibly the piece made of ceramic material.
[0084] Implementing the invention requires the intermediate elements to be made of a material that is selected to remain within its elastic domain. It is also important to fabricate the intermediate connection elements out of a material that is as strong as possible in order to have greater latitude in mechanical weakening, i.e. improved flexibility.
[0085] FIGS. 9A and 9B show properties that need to be taken into account when selecting the material for the intermediate element. In FIG. 9A , curve IMD representing the mechanical properties of an intermediate connection element that is solid and ductile is given for comparison with the curve HX for the metal piece that is to be assembled. A loss in mechanical properties PP (elastic limit, rupture strength) can be observed.
[0086] The curve MP represents the potentially ideal mechanical properties of an intermediate connection element for brazing at a temperature T S corresponding to the solidification temperature of the brazing compound.
[0087] Below the solidification temperature T S , the intermediate element should ideally have mechanical properties that are weaker than those of the metal piece for assembly (HX) so as to enable it to act as a ductile material. It also needs to have mechanical strength properties that are at least sufficient at an operating temperature T F , where the operating temperature T F is empirically about ⅔ of the above-mentioned solidification temperature T S , in degrees Celsius, which can be written as follows:
[0000]
T
S
=
3
2
T
F
[0000] where T S and T F are expressed in degrees Celsius.
[0088] However, the person skilled in the art knows that these requirements, represented by the curve MP cannot be achieved with an intermediate element that is solid and ductile. To mitigate the loss of property PP observed with such a material, it is necessary for the assembly to be overdimensioned.
[0089] FIG. 9B shows a curve ISC for the mechanical properties of a material for a deformable intermediate connection element that is advantageously suitable for use in the invention. This curve corresponds to a highly refractory material (e.g. alloys based on iron, nickel, chromium, aluminum, titanium) having mechanical properties that degrade little at high operating temperature.
[0090] Instead of observing a loss of property PP as in FIG. 9A , there can be seen a structural weakening margin MAS. This margin is controllable and used for adjusting the flexibility of the structure at will.
[0091] The deformable intermediate connection elements may also be in the form of a one-dimensional (1D) undulating sheet, a stamped sheet, or indeed a sheet with corrugations crossing in two dimensions (2D).
[0092] By way of example, materials for making these structures can be selected from the following list: 1D undulating sheet of alloy based on FeCrAlY; 2D corrugated sheet of Haynes 230 (stamped sheet); crossed 2D corrugated sheets of Nimonic 75 (one-dimensional corrugated tape inserted and brazed in the corrugation recesses of a one-dimensional corrugated sheet, embodiment not shown).
[0093] Such structures can be used in particular for assembling parts made of ceramic material based on SiC with metal parts based on Inconel 718 or TA6V alloy, this list not being limiting.
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An assembly including a metal piece, a piece made of ceramic material, and at least one intermediate connection element assembled to each of the pieces by brazing. The intermediate connection element includes a deformable sheet presenting at least two flat zones brazed to respective ones of the pieces, the two flat zones being interconnected by a deformable zone presenting at least two free undulations oriented in alternation towards the metal piece and towards the piece made of ceramic material.
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FIELD OF THE INVENTION
The present invention is directed to medical equipment used in orthopaedics and traumatology to treat various congenital and acquired shortenings and other defects or skeletal segments, and, more particularly, the invention is directed to a drive system for a compression-distraction-torsion apparatus.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,615,338 (incorporated by reference herein) to Ilizarov discloses an orthopaedic procedure employing an external device which fixes to the bone by means of slender pins and which tensions or distracts the bone at a doctor-selected rate and rhythm of tensioning or distraction, with resulting growth of new bone, skin, muscle and nerves. The Ilizarov external fixation system uses a variety of perforated rings connected by graduated telescopic rods. Generally, the rods are distracted 1/4 of a millimeter four times a day for a total distraction of 1 mm per day. When the desired length is achieved, the bone is then held in place to allow consolidation. The consolidation period is generally the same as the time needed for distraction, generally. Thus, for a distraction period of four weeks, the consolidation period would be four weeks, for a total treatment time of eight weeks. Research shows that a rate of distraction of 1/60 of a mm sixty times a day produces even better results than 1/4 of a mm increments.
Generally, in the Ilizarov system, the nuts of the graduated telescopic rods interconnecting the support members are turned manually to cause distraction. U.S. Pat. No. 4,615,338 discloses an automatic drive system employing a lead screw mated with a ratchet wheel placed in a housing, and a pawl interacting with teeth of the ratchet wheel to drive the ratchet wheel to adjust the length of the telescopic rod.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an autodistractor system which employs at least one motor to adjust the length of a rod member in an Ilizarov-type system, and a programmable controller which controls the motor or motors and stores information regarding the rod length adjustments.
It is a further object of the present invention to provide a compression-distraction-torsion apparatus employing a programmable controller whereby a doctor can adapt the system to particular needs based on the number of motors, the process type (i.e., compression, distraction or torsion), the number of millimeters advancement per day, the number of times the motor or motors are to be advanced per day to achieve the desired total daily advancement, and the total movement required for the overall treatment.
The above and further objects of the present invention are achieved in a surgical, orthopaedic apparatus which comprises a plurality of support members; a plurality of rods interconnecting the support members, the rods including adjustment means for enabling the rod length to be adjusted; a plurality of pins attached to the support members, the pins including means for passing through bone of a patient; and an automatic drive means for controlling the adjustment means of the rods to adjust the rod length of the rods to alter the relative positions of the support members. The drive means comprises at least one motor (which may be a digital motor) for incrementally adjusting the adjustment means to stepwise adjust the rod length, and a controller means for providing pulses to the motor to control the incremental adjustments of the rod length and for storing information regarding the number of stepwise adjustments of the rod length by the motor during an overall treatment procedure. The invention typically includes a plurality of motors corresponding in number to the plurality of rod members.
The invention can further include a feedback sensor means for sensing the amount of adjustment of the length of the rods and for providing data representing the sensed amount of adjustment to the controller means. The controller means can further include a comparator means for comparing the information regarding the number of stepwise adjustments with the data representing the sensed amount of adjustment.
The apparatus can further include a manual control means for controlling the adjustment means of the rods to adjust the rod length in order to alter the relative positions of the support members, and a switch means for selecting between a manual mode in which only the manual control means controls the adjustment means of the rods and an automatic mode in which only the automatic drive means controls the adjustment means.
The support members can comprise a ring having a plurality of radially extending through holes having said pins extending therethrough. The rods can comprise a graduated telescopic rod, and the adjustment means of the rods can comprise a nut. The motors can be mounted on the graduated telescopic rods.
The apparatus can include a gear mount ring mounted around the nut of the telescopic rods, with the gear mount ring comprising, on one end, a detent latching loop engaged with a projection of the nut such that the gear mount ring and the nut are rotatable in concert with one another and, on its other end, an internal gear ring. A gear box is connected to the motor and includes an output gear comprising a gear means for engagement with the internal gear ring of the gear mount ring. The apparatus can further include means for enabling the gear mount ring to move axially relative to the nut so as to cause the gear mount ring to disengage from the output gear while maintaining engagement between the detent latching loop and the projection of the nut. As a result, when the gear mount ring is disengaged from the output gear, a manual mode is provided in which the nut can be manually rotated, and when the gear mount ring is engaged with the output gear, an automatic mode is provided in which the nut can be rotated by the automatic drive means.
The feedback sensor means can be an infrared sensor or a magnetic reed switch.
The apparatus can further include a display means, connected to the controller means, for displaying a representation of the information regarding the number of stepwise adjustments of the rod length during the overall treatment procedure.
According to the invention there is also provided a method of controlling a surgical, orthopaedic apparatus which includes a plurality of support members; a plurality of rods interconnecting the support members, the rods including adjustment means for enabling the rod length to be adjusted; and a plurality of pins attached to the support members, the pins including means for passing through bone of a patient. The method comprises controlling the adjustment means of the rods to adjust the rod length to adjust the relative positions of the support members by employing a plurality of motors corresponding to the plurality of rods to incrementally adjust the adjustment means to stepwise adjust the rod length and employing a controller means to provide pulses to the motors to control the incremental adjustments of the rods and to store information regarding the number of stepwise adjustments of the rod length by the motors.
The method can further comprise sensing the amount of adjustment of the rod length and providing data representing the sensed amount of adjustment to the controller means based on a comparison of the information regarding the number of stepwise adjustments with the data representing the sensed amount of adjustment. The method can further comprise displaying a representation of the information regarding the number of stepwise adjustments of the rod length.
The method can further comprise providing a test pulse to each one of the motors and checking whether each of the motors responds properly to the pulse. The method can further comprise (i) storing in a counter a predetermined count representing a total number of pulses required to be sent to each motor to step the motor a required amount at each advance cycle and a total cycle count representing a number of advance cycles required for each of the motors to achieve a desired total treatment movement; (ii) providing a control pulse to a first one of the motors to advance it one increment; (iii) determining whether the first one of the motors is turned on in response to the control pulse; (iv) turning off the first one of the motors; (v) determining whether the first one of the motors is turned off; (vi) decrementing the predetermined count stored in step (i) to provide a decremented count responsive to the first one of the motors being advanced one increment; and (vii) checking whether the decremented count obtained in step (vi) is greater than zero, and if so, repeating steps (ii)-(vi) with respect to the first one of said digital motors. The method can further comprise, responsive to a determination that the decremented count obtained in step (vi) is equal to zero, storing again in the counter the predetermined count and performing steps (i)-(vii) successively with respect to all other ones of the motors to complete an advance cycle for the motors.
The method can further comprise counting a number of the advance cycles carried out with respect to the motors; comparing the number of advance cycles with the total cycle count representing the number of advance cycles required to achieve the desired total treatment movement; performing steps (i)-(vii) with respect to the motors to carry out another advance cycle after a predetermined time delay responsive to a determination that the number of advance cycles is less than the total cycle count; and terminating the treatment responsive to a determination that the number of advance cycles is equal to the total cycle count.
The above and other objects, advantages and features of the invention will be more fully understood when considered in conjunction with the following discussion and to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1D illustrate the autodistractor/compressor motor assembly according to the invention mounted on a telescopic rod;
FIG. 2 is a top view of a gear mount ring of the FIG. 1 system;
FIG. 3 is a side view of the gear mount ring;
FIG. 4 is another side view of the gear mount ring illustrating the detent latching loop;
FIG. 5 illustrates the motor mounts;
FIG. 6 illustrates the overall autodistractor/ compressor/torsioner system according to the invention;
FIG. 7 illustrates the autodistractor/compressor/ torsioner system in block diagram form;
FIG. 8 illustrates further details of the system in partial block diagram format;
FIG. 9 illustrates a typical pulse supplied to a digital motor;
FIG. 10 illustrates the interactive set-up procedure;
FIG. 11 shows a microcontroller;
FIG. 12 illustrates grey and white parameters used in the long-term delay subroutine; and
FIGS. 13-29 illustrate the operation of the automatic distraction/compression/torsion system according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A-1D show the autodistractor/compressor/ torsioner motor assembly 10 according to the invention mounted on a telescopic rod 20. The assembly includes a motor 11 (which may be a digital motor) mounted via motor mount 14 onto rod 20, gear box 13 associated with motor 11, and an output gear 15 controlled by motor 11. A gear mount ring 17 is mounted on nut 21 of graduated telescopic rod 20. Gear mount ring 17 includes a detent latching loop 19 which engages with a projecting member 23 of nut 21 and an internal gear ring 16 which engages with output gear 15 of the digital motor-gear box combination. Member 23 is a spring loaded detent latch which locks at 90° rotations of nut 21. Detent latching loop 19 holds the latch open to allow rotation of nut 21 by the motor means. When gear mount ring 17 is in the manual mode, latch 23 performs normally. Set screw 18 (FIG. 2) passes through a through bore in gear mount ring 17 and abuts against nut 21. In this manner, motor 11 controls rotation of gear mount ring 17 and, in turn, nut 21. Gear mount ring 17 can be manually moved in the direction of arrow A so as to provide a switching means to select between a manual mode in which internal gear ring 16 is disengaged from output gear 15 so that nut 21 can be rotated manually and an automatic mode in which internal gear ring 17 is coupled with output gear 15 such that motor 11 is able to rotate nut 21.
A programmable controller (PU 30), which is programmable in a manner discussed below, is connected to motor 11 to provide signals thereto to control the stepwise or incremental adjustments of nut 21 and, hence, of the length of rod 20. As described in detail below, controller 30 also stores information regarding the number of stepwise adjustments of the rod length by motor 11 during the overall treatment procedure. This information is converted into a format readily comprehensible by a doctor and displayed on a display 140 (see FIG. 7) to enable determination of the progress of the overall treatment.
A feedback sensor 40 is provided to sense the actual amount of physical adjustment of the length of rod 20. Sensor 40 is preferably an infrared sensor, but may also be a magnetic reed sensor. In the magnetic sensor embodiment, a magnet is mounted on e.g., gear 15, ring 17 or nut 21; when the magnet lines up with the magnetic reed switch, a signal is sent back to controller 30. The magnetic sensor embodiment, however, is not preferred due to its sensitivity to the presence of external electromagnetic fields. In the infrared embodiment, sensor 40 receives infrared light reflected off a reflector 40A (FIG. 8) mounted, e.g., on gear mount ring 17. Reflector 40A could also be mounted, e.g., on nut 21 or gear 15. Specifically, sensor 40 enables controller 30 to count and store the number of revolutions of gear mount ring 17 and hence nut 21. Sensor 40 thus provides data to controller 30 representing the sensed amount of adjustment of the rod length. Controller 30 includes a means for comparing this sensed adjustment amount with the stored information regarding the number of stepwise adjustments of the rod length. If a non-equivalence is detected, an investigation of its cause will be carried out.
FIGS. 2-4 show details of gear mount ring 17, including an internal gear ring 16, a detent latching loop 19 and a set screw 18. FIG. 5 illustrates the particular features of motor mount 14 including a through bore 12A for receiving motor 11 and a through bore 12B by which mount 14 is secured to rod 20. The ends of mount 14 are clamped as illustrated.
FIG. 6 illustrates the overall autodistractor/ compressor/torsioner system 50 according to the invention. This system includes a plurality of support members 60, preferably in the form of perforated rings. Rings 60 include holes 61 in which a plurality of graduated telescopic rods 20 are secured in order to interconnect support rings 60. A plurality of pins 70 are attached to support members 60 and pass through the bone 80 of a patient. FIG. 6 shows a plurality of motors 11 and gear mount rings 17 mounted on nuts 21 of rods 20, these elements having the same structure as that illustrated in FIG. 1. The FIG. 6 system incorporates the elements of motor assembly 10, rod 20, controller 30 and sensor 40 shown in FIGS. 1-5. Controller 30 controls each of motors 11 mounted on the plurality of rods 20 and receives feedback from sensors 40 associated with each of motors 11 as described above in connection with FIG. 1.
FIG. 7 and 8 illustrate the autodistractor/compressor/ torsioner system in block diagram form. Controller 30 is in the form of a CPU synchronized with a clock 31. Software 110 controls controller 30 as described in detail below in connection with the flow charts of FIGS. 13-19. Sensor 40 provides feedback data regarding the actual position of rods 20; this data is stored in counters 120 and fed back to CPU 30. CPU 30 also provides data to display drivers 130 which drive display 140 to display the data in a format readily comprehensible to the doctor to enable determination of the progress of the overall treatment. Panel switches 100A include a display switch to control actuation of display 140. CPU 30 also provides output signals to drivers 90 for motors 11 to control the stepwise adjustments of rods 20.
As shown in FIG. 7, an output monitor unit 190 monitors the output from the CPU battery. If this output level falls below a predetermined threshold, monitor unit 190 sends a signal to battery switching unit 200 which is connected to the motor battery. This signal provided by monitor unit 190 to switching unit 200 causes unit 200 to switch the output from the battery CPU 30. This insures continued supply of power to the CPU and provides protection against system failure in the event of failure of the CPU battery.
With reference to FIGS. 13-29, the operation of the automatic distractor/compression/torsion system according to the invention, is as follows.
OVERVIEW
The setup program is designed to operate on a personal computer (PC). This allows the doctor to customize the the software in the memory of the microcontroller 170 for each particular distraction/compression/torsion case. The setup program will ask for and accept input on the number of motors, the process, i.e., compression, distraction or torsion, the number of millimeters movement per day, the number of times the motor will advance per day to achieve the required movement per day and the total movement required for the overall treatment. The setup program also collects information regarding the patient's name, doctor's name, chip number, date and other relevant information. Hard copies are generated of all inputted information to allow the doctor to verify the input, identify the microprocessor (CPU 30); record the settings for patient records, and keep other necessary records.
After the microcontroller software has been downloaded into the microcontroller 170 memory and verified and the microcontroller 170 has been inserted into the electronics assembly, the software performs an initial check to be certain the electronics system is connected appropriately and the right chip has been inserted. If not, the software will trigger an alarm and an error code will be displayed.
If no error exists, the doctor can then actuate the start switch. The system will advance the motors and check to be certain all the motors are functioning properly. If not, the software will shut down the motors, display an error code and trigger the alarm.
Thereafter, the software controls the movement of each motor and tests to be certain that the motor is advancing the gear the amount established in the setup program via a feedback system. The advancement tests are run on a continuing basis to prevent a "runaway" or stalled motor condition. The system will shut down the motors, display an error code, and trigger the alarm if an advancement error is detected.
The software also monitors the current supply from the batteries to the central processing unit CPU 3 having EPROM microcontroller 170 installed therein, display and motors. If the current supply is low to CPU 30, display or motors, the software will shut down the motors, display an error code and trigger the alarm. If the current to central processing unit 30 is low, the software will also shift the central processing battery supply to the motor power supply.
The software allows an operator to request a display at any time. The display will cycle through the position of each motor for each display request.
The software also allows transient electromagnetic fields to create a temporary current in the motor leads without shutting the motors down or triggering the alarm. The software further allows the doctor to manually put the system on standby for adjustments or other necessary interruptions.
The software shuts the motors down, displays the completion code, and triggers the alarm when the system has achieved the total required movement for the overall treatment procedure.
DETAILED DISCUSSION
The ROMSET routine (FIG. 13A) is run on a personal computer (PC) by the doctor and sets up EPROM microprocessor microcontroller 170 of the (PU 30). The doctor enters data in response to queries regarding the number of motors, the direction (compression, distraction or torsion), rate (mm/day), rhythm (times/day), total movement required for the overall treatment and CPU serial number. The program then does a table computation at 303, based on the above-entered data to generate a table of values to be called in software subsequently. This is done by converting the rate, rhythm and total treatment movement input by the doctor to data which the motors can employ -- i.e., how many pulses are required to advance the motor through one advance cycle and the long term time delay imposed on the motors between advance cycles in order to achieve the movement equal to the required mm's/day at the given rhythm. Other miscellaneous data is also entered as discussed below. This table is then merged with the source code 305, and further routine processing is done to load the EPROM at step 307. As noted, hard copy can also be generated at 309". FIGS. 10 and 11 illustrate a procedure for setting up or loading the EPROM microprocessor (PU 30) via a PC 150, a PROM 160 and a microcontroller 170 which ultimately is inserted into an electronics board or assembly 180. After this loading procedure, microcontroller 170 is inserted into board 180 which in turn is installed in CPU 30. By reprogramming microcontroller 170, in the manner discussed above, the doctor is able to design a new treatment procedure as desired.
After the EPROM is programmed and installed on board 180, operation may begin. In the EPROM routine (FIG. 13) initially, at step 25, a check is done to determine whether the system is operating properly and whether the correct chip (i.e., board 180 containing microcontroller 170) has been loaded into CPU 30. If no, an error code is set and a termination routine TRMNAT (to be described in detail below) is called. If yes, at 28 a successful powerup is acknowledged via an acoustic signal and a visual display. At 29, the system waits for the doctor to flip a start switch and, thereafter, at 30, the CPU clock is synchronized with the clock in the electronics assembly 180. At 31, a single pulse is sent to each of the motors and a check is done to be certain all motors are properly connected. At 32, if the system is not indicating proper functioning, an error code is set, and the termination routine TRMNAT is called. If the system is indicating proper functioning, this is acknowledged at 36, with an acoustic alarm and a visual display occurring. At 37, a first run flag is burned by burning a fuse in the electronics assembly.
At 13a, the total cycle count (i.e., the number of advance cycles to achieve the total treatment movement) is loaded, and at 13, the motor count (number of motors, e.g., 4) is loaded. At 14, the Mx pulse count (i.e., the number of pulses required to cause the particular motor to step the required amount at each particular advance cycle throughout the treatment) is loaded.
At 15, a given motor is turned on by sending one pulse to advance the Mx motor one increment, and at 16 a routine ONPLSTST is called to certify that the motor is on. At 17, the motor is turned off, and at 18 a routine OFFPLSTST is called to certify that the motor is off.
At 19, the counter is decremented. If the count has not reached zero, steps 14-18 are repeated. This is repeated until the count equals zero.
Thereafter, at 20 the system moves to the next motor and repeats steps 14-19 until the count for this motor reaches zero. Step 20 ends when each of the motors have been put through steps 14-19.
At 21, the CPU memory is updated with data indicating that steps 14-20 have been completed for each of the motors.
At 22, routine LTMDLY is called. This is a long-term delay routine which imposes a delay on the motors between advance cycles carried out by steps 14-20. This means all of the motors are stepped through one advance cycle, and then the long-term delay occurs. Then, each motor is again stepped through one advance cycle. The process is repeated until step 21 indicates the overall distraction, compression or torsion treatment is completed. At 23, an acknowledgment that the procedure is completed is displayed, and at 24 the termination routine TRMNAT ends the procedure.
The subroutine ONPLSTST (on pulse test) is as follows. At 38, the time the motor is to be on is loaded, as obtained from the table generated during the ROMSET program. At 39, a delay is imposed to avoid checking the current pulse at the beginning of the pulse to avoid problems because of initial abnormalities. FIG. 9 shows a typical pulse, with readings from region B being avoided. The exact delay is set depending upon the type of digital motor employed.
At 40, the current flowing to the motor is checked. At 41, it is determined whether the current flow meets an acceptable limit. At 46, if the current flow is not acceptable, the "no current" error count is located. At 47, the error count is advanced by 1 to account for new "no current" error. At 48, the new "no current" error count is loaded in the memory. At 49, the acceptable error established in the ROMSET program (i.e., how many transient errors will be allowed before the movement of the system is terminated, such as 50 or 100; this allows flexibility so the doctor can make a determination depending on the environment of the patient). At 50, the new "no current" error count is checked, and a determination is made regarding whether it is below the maximum established as too many errors. At 52, if the error count is above the maximum number of allowable "no current" errors, the system physically burns a fuse designated the "open" indicator to show that, for some reason, there has been "no current" to the motor when there should have been current more than a maximum number of established times. Possible causes of the "no current" condition could be an open circuit or extensive interference from an external electrical field. At 50b, if the error count is below the maximum number of allowable "no current" errors, the system loops back prior to DECREMENT ON-TIME COUNT and the process is continued.
At 42, if the current flow is acceptable, a delay is imposed to match the time use for a "no current" decision.
At 43, the on-time count is decremented. For example, if the Mx on-time was 3 cycles through this loop, then, after the first time through this routine, the on-time count is changed to two. At 44, a check is made to determine, if it is the end of the count in LOAD Mx ON-TIME 38. At 45, at the end of the count loaded in LOAD Mx ON-TIME 38, a return is made to the EPROM program at step 17. At 44b, if the system is not at the end of the count loaded in LOAD Mx ON-TIME, the system loops back through the routine as shown. At 51, the "no current" error code is set into the error code memory.
The subroutine LTMDLY (long-term time delay) at 99 loads the total count for the pause (e.g., 2,000) between motor movement cycles set in the ROMSET program. This will be dependent upon how many times/day the doctor desires the system to advance. At 104, the display request memory bit is loaded. At 105, it is determined whether a display request flag is in the display request bit, and, if so, at 106, the DISPLAY subroutine is called. If there is no flag, at 107, the delay count is loaded. This delay count is set in the ROMSET program to match the time required for the display subroutine.
At 108, an I/O check is made for a display request. At 109, a check is made whether the display button has been pushed and the associated electronics hardware activated. If a display request exists, at 111, the display flag is set. If no display request has been made, at 110, a delay is imposed to match the time required to set the flag.
At 112, the count is decremented to account for advancement of one cycle. At 113, a check is made as to whether the value now stored in the delay indicates the end of the count. If not, at 113b, the system cycles back through the loop. If it is the end of the count, at 70, the number of motors is loaded. This is determined from the table established in the ROMSET program. At 71, the motor position count (for example, motor 1) is loaded from the table established in the ROMSET program. At 72, it is determined whether this position count indicates the sensor should be ON. At 74, if the sensor is ON, the sensor is then checked at 76. If yes, at 78, a delay is imposed to match the time it takes to check other alternatives. If the sensor is OFF, at 76a, the rotation error code is set. If the sensor should not be 0N based on the position count of the motor, at 73, the position parameters are loaded for the grey 1 area, i.e., between 5 and 10 is grey 1. This is illustrated in FIG. 12. At 75, a determination is made as to whether the position count corresponds to a grey 1 area. This is done by comparing the actual position count to the range for grey 1, e.g., 5-10. Thus, if the actual position count is 6, this corresponds to a grey 1 area, whereas a count of 2 would not. At 75b it is determined that the system should be in the grey 1 area, and at 75a, it should determined that the system is not be in the grey 1 area. At 79, a delay is imposed to match the time required for other checks.
At 77, the position parameters are loaded for the white area (see FIG. 12). At 80, a determination is made as to whether the system should be in the white area according to the position count. Step 80a corresponds to a count indicating a white area, and 80b indicates a count not quite corresponding to the white area. At 81-82b, a check is made as to whether the motor sensor is ON. At 83, if the sensor is ON, the rotation error code is set. At 84, a delay count is imposed to match the time required for the computer (CPU 30) to do other checks. At 85-85b, a determination is made as to whether all of the motors have been checked. At 86, the pause count is decremented to account for advancement of one cycle. At 87-87b, a determination is made as to whether the system is at the end of the total established pause count. At 88, the system looks for a standby request which is a jumper connected by the doctor. At 89-89b, a determination is made as to whether the standby jumper has been connected. At 90, the system is returned to load motor count (step 13).
Turning now to the subroutine DISPLAY, if the system is at the end of the count, at 91, the number of motors is loaded based on the table established by the ROMSET program. At 92, the Mx distraction count is loaded. In other words, this count indicates how far the motor has distracted the telescopic rod. At 93, an indication of the amount of the distraction is sent to the display. At 94, a delay is imposed to allow the doctor to view the distraction distance. At 95, the system decrements to the next motor sequentially, i.e., the system moves from Mx=M2 to Mx=M1. At 96, a determination is made as to whether this is the last motor, and at 97, a delay is imposed. At 98, a return is made to step 70 the number of motors or alternatively the display subroutine can be called to allow the doctor to view the current distraction distance as discussed below.
With respect to the subroutine RESET illustrated in FIG. 22A, at 141, the software error flags set earlier which caused the system to call the TRMNAT subroutine are cleared. At 142, the system checks for hardware error flags. All blown fuses must be replaced before resetting the system. Blown fuses show as a hardware error flag. At 143-143b, a check is made as to whether the hardware flags are OK. At 144, the "not ready" code is set for the display. At 145, the alarm interval in the TRMNAT subroutine is changed. At 146, the system goes to the TRMNAT subroutine. At 147, the system goes back to just prior to step 28, which is the acknowledged successful power-up step in the EPROM routine.
Regarding the TRMNAT subroutine, at 114, the alarm interval set in the ROMSET program is loaded, and at 115, the acoustic alarm code (alarm sound) is loaded. At 116, the alarm is turned on by sending current to the alarm. Step 117 imposes a delay to allow the desired length of sound. Step 118 turns the alarm off. At 119, a delay is imposed to allow the desired length of time between alarm sounds. At 120, a determination is made as to whether the alarm has been activated enough times to meet the alarm interval from step 114. At 121, an "off alarm" delay is imposed. This is set in the ROMSET program and represents a period of time between alarms. At 122, the system checks to determine whether the setup has a reset capability from the ROMSET program. At 123, the system determines whether a reset is acceptable. At 124, the system checks for a reset jumper in the electronics hardware. At 125, a determination is made as to whether the reset jumper is in place. At 126, the system goes to the RESET subroutine. At 127, the system checks for a display request, i.e., whether the doctor has pushed the button for the display. At 128, a determination is made as to whether the display has been requested. If yes, at 131, the error code is loaded for the error which caused the system to go into the TRMNAT subroutine. At 132, the error code signal is sent to the display for viewing. At 133, a delay is imposed to allow the doctor sufficient time to view the code. At 134, the display subroutine is called to allow the doctor to view the current distraction distance. If no display request has been made, at 129b, a delay is imposed to match the time for the error code display and current distraction distance displays. At 129, the "alarm off" delay count is decremented, and at 130, a determination is made as to whether the end of the "alarm off" period is present based on the number loaded at step 121.
Steps 190-225 represent a more detailed or alternative version of the EPROM program. At 190, an initial power-up check is made to be certain that the chip is acceptable, and the RAM is checked. Also, a check is made to be certain that the correct chip has been inserted. At 191, a determination is made as to whether the initial power-up check indicates the system has checked out acceptably. If not, the microprocessor error code is set at 193, and at 194, the system goes to the TRMNAT subroutine. If the system is checking out acceptably, at 192, the WMSTART subroutine from the RESET subroutine is carried out. At 195, a successful power-up code is loaded. At 196, the SYSOK subroutine is called, which will provide an audio OK signal and display a successful power-up code. At 197, the system checks for a start signal (which is a hardware jumper). At 198, the system queries whether a start signal is present. At 199, the CPU clock is synchronized with an external clock to verify that the chip is functioning correctly.
At 200, the motor count is loaded, to indicate the number of motors set in the ROMSET program. At 201, motor x is turned on by supplying power to the motor. At 202, the subroutine MTRCHKON is called, which tests whether there is current to the motor and shuts the system down if not. At 203, motor x is turned off. At 204, subroutine MTRCHKOF is called, which tests whether there is no current to the motor and shuts the system down if there is current to the motor.
At 205, the motor count is decremented by 1. At 206, a determination is made as to whether this is the last motor. At 207, a successful start code is loaded. At 208, the SYSOK subroutine is called, and at 209, the first run flag is burned by physically burning a fuse which acknowledges the successful startup.
At 210, the total cycle count is loaded, which has been established in the ROMSET program and represents the total number of movements of the motor required to achieve the overall desired distraction for the entire treatment procedure. At 211, the motor count is loaded, which is the number of motors established in the ROMSET program. At 212, the number of pulses to be supplied by motor x is loaded; this number is also established in the ROMSET program. At 213, the motor is turned ON and at 214, the ONPLSTST subroutine is called. This latter subroutine checks to be certain there is current to the motor. There is a cumulative error counter which will cause the system to alarm and shut down if there have been too many times when no current is flowing during motor ON time. At 215, the motor is turned OFF. At 216, the OFPLSTST subroutine is called. This checks to be certain there is no current to the motor when the motor is to be OFF. There is a cumulative error counter which will cause the system to alarm and shut down if there have too many times when current is flowing during motor OFF time. At 217, the motor x pulse count is decremented. For example, if a total of 133 pulses were required, the pulse count would be decremented to 132 after the first time through. At 218, the system checks whether the required pulses (e.g., 133) have been sent. If yes, at 219, the motor count is decremented. At 220, a determination is made as to whether this is the last motor. At 221, the cycle count is decremented, and at 222, a determination is made as to whether the total required cycles for the overall treatment have been completed. If yes, at 223, the completion code is set, and the system proceeds to the TRMNAT subroutine. This latter subroutine causes the system to alarm and allows no further movement of the system. It also allows the doctor to view an error code for problems and display cumulative movements of the telescopic rods prior to system shutdown. It also allows the doctor the option of resetting the system after correcting any problem.
At 225, the LTMDLY subroutine is called. This allows the doctor to display cumulative movement of the telescopic rods. The system checks to be certain that the advancement nut has moved an amount equivalent to the amount expected based on the number of pulses sent to the motor within a specified range. This also provides a delay between motor movements.
With respect to the MTRCHKOF (motor check OFF) subroutine, the logic is the same as the OFPLSTST subroutine.
With respect to the MTRCHKON (motor check ON) subroutine, the logic is the same as the OFPLSTST subroutine.
Turning now to the SYSOK subroutine, at 149, the code is sent to the display, and at 150, the alarm interval is loaded to determine how many times the alarm will beep. At 150, the acoustic alarm code (alarm sound code) is loaded. At 152, the alarm is turned ON, and at 153, a delay is imposed to obtain the desired length of time. At 154, the alarm is turned OFF, and at 155, a delay is imposed to provide the desired time duration between beeps. At 156, a check is made as to whether the alarm interval is complete by keeping track of the number of beeps. At 157, a delay is imposed to allow the doctor or a technician sufficient time to review the code.
With respect to the OFPLSTST subroutine, this is the same as the ONPLSTST subroutine, with the exception that the system checks to be certain that current is zero rather than that current flow is sufficient.
It should be noted that the above description and the accompanying drawings are merely illustrative of the application of the principles of the present invention and are not limiting. Numerous other arrangements which embody the principles of the invention and which fall within its spirit and scope may be readily devised by those skilled in the art. Accordingly, the invention is not limited by the foregoing description, but is only limited by the summary or scope of the invention as described in this application.
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An orthopaedic system is provided which includes a plurality of support members, a plurality of rods interconnecting the support members, a plurality of pins attached to the support members for passing through bone of a patient, and an automatic drive mechanism to control an adjustment mechanism of the rods to adjust the rod length of the rods to alter the relative positions of the support members. The drive mechanism includes at least one motor for incrementally adjusting the adjustment mechanism of at least one of the rods and a controller mechanism for providing pulses to the motor and for storing information regarding the number of stepwise adjustments of the rod length by the motor.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a radar apparatus which is mounted on an automobile and/or installed on a road facility so as to detect an object (obstacle and traveling vehicle) appeared on a road. That is, the present invention is related to an FM-CW radar apparatus for detecting a beat signal of an FM transmission signal wave, which is produced by a reflection wave reflected from an object, and for analyzing a frequency component of the beat signal so as to calculate both a distance and a velocity-of the object. More specifically, the present invention is directed to an FM-CW radar apparatus capable of reducing a measuring time duration by ½, required to detect an object in such a manner that both an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction are simultaneously transmitted, and then, beat frequency components with respect to the respective FM modulation waves are analyzed so as to calculate a distance and a velocity of an object.
[0003] 2. Description of the Related Art
[0004] In general, as described in, for instance, Japanese Patent Application Laid-open No. 63-275976 (Japanese Patent No. 2550574), FM-CW type radar apparatus have be widely used as radar apparatus designed for automobiles.
[0005] [0005]FIG. 7 and FIG. 8 are explanatory diagrams for explaining a basic idea of a conventional FM-CW radar apparatus. That is, FIG. 7 represents a change in reception frequencies and a change in beat frequencies in the case that a signal is transmitted to a stationary object, whereas FIG. 8 shows a change in reception frequencies and a change in beat frequencies in such a case that a signal is transmitted to a moving object.
[0006] In these drawings, transmission frequencies of transmission signals to objects (targets) which should be detected; reception frequencies of reflection signals reflected/received from the objects; and the respective beat frequencies “fbu” and “fbd” obtained when the signal is frequency-modulated along the up direction, and the signal is frequency-modulated along the down direction are represented in the form of waveforms as a relationship with respect to time “t”, respectively.
[0007] In FIG. 7, a carrier wave (FM modulation wave) having a center frequency “f 0 ” is transmitted by way of an FM modulation method by which the carrier wave is repeatedly changed to a triangular shape.
[0008] A triangular-shaped wave indicated by a solid line in FIG. 7 shows a relationship between the frequency of the transmission signal and the time “t”. Another triangular-shaped wave indicated by a broken line shows a relationship between a reception signal and the time “t”. This reception signal is reflected/received from, for example, an object located at a distance “R”. This triangular-shaped wave is delayed by such a time duration defined by that the transmission signal has been transmitted, and the reflection signal is received.
[0009] In this case, assuming now that frequencies of beat signals constructed of frequency differences between transmission signals and reception signals during frequency-up modulation and also frequency-down modulation are selected to be “fbu” and “fbd”, the respective beat frequencies “fbu” and “fbd” are expressed by the below-mentioned equation (1).
fbu=−fr
fbd=fr (1)
[0010] It should be noted that in the above-described equation (1), symbol “fr” shows a beat frequency caused by a reflection signal which is reflected from a stationary object located at a distance of “R”. This beat frequency is given by the below-mentioned equation (2) by employing a repetition frequency “fm” of an FM signal (FM modulation wave), a frequency shift width “ΔF” of the FM signal, and a light velocity “c”.
fr= 4× R·fm·ΔF/c (2)
[0011] Based upon this equation (2), the distance “R” is calculated in accordance with the below-mentioned equation (3).
R=fr·c/ (4× fm·ΔF ) (3)
[0012] On the other hand, in the case that an object is moved, both a frequency change in transmission signals and a frequency change in reception signals with respect to time, which are caused by the Doppler effect, are as indicated in FIG. 8.
[0013] In general, a Doppler frequency “fv” is given by the following equation (4).
fv= 2× vr·f 0 /c (4)
[0014] In this equation (4), symbol “vr” indicates a velocity (speed) of the object. This velocity “vr” of the object may be given by the below-mentioned equation (5).
vr=fv·c/ (2× f 0 (5)
[0015] Also, in FIG. 8, the beat frequencies “fbu” and “fbd” which are caused by reflection signals reflected from such an object which is approached are defined based upon the below-mentioned equation (6), namely are equal to such values obtained by adding the Doppler frequency “fv” to the beat frequencies obtained in the case of the stationary object.
fbu=−fr+fv
fbd=fr+fv (6)
[0016] In accordance with the above-described equation (6), both the Doppler frequency “fv” and the beat frequency “fr” are expressed based upon the below-mentioned equation (7).
fv= ( fbd+fbu )/2
fr= ( fbd−fbu )/2 (7)
[0017] The above-explained equation (7) is substituted for the above-mentioned equations (3) and (5), so that both the distance “R” of the object and the velocity “vr” of this object may be calculated by employing the measured beat frequencies “fbu” and “fbd” as follows.
R= ( fbd−fbu )· c/ (8× fm·ΔF )
vr= ( fbd+fbu )· c/ (4× f 0) (8)
[0018] In this case, resolution “Δv” of the velocity “vr” is determined based upon analyzable minimum frequencies of the beat frequencies “fd” and “fr”. Since the repetition frequency of the FM modulation wave is equal to “fm”, this resolution “Δv” of the velocity “vr” may be determined for either a frequency ascent time period or a frequency descent time period (=2×fm) one time.
[0019] In other words, the resolution “Δv” of the velocity “vr” may be expressed by the following equation (9).
Δv=fm·c/f 0 (9)
[0020] On the other hand, in the case that a plurality of objects are present on a road, a plurality of beat signals are produced during the frequency-up modulation and also during the frequency-down modulation, the total number of which correspond to the total number of these objects.
[0021] In this case, in order to detect only a specific object, a beat signal of the relevant object is selected from the plurality of beat signals. Then, both the distance “R” and the velocity “vr” of this specific object are calculated from the respective beat signals during both the frequency-up modulation and the frequency-down modulation.
[0022] In order to select a combination of beat signals, such data as magnitudes of signal components of these beat signals may be used as reference purposes.
[0023] In other words, such beat signals whose signal levels are substantially equal to each other are selected from signals obtained during the frequency-up modulation and the frequency-down modulation, and then, the selected beat signals are combined with each other.
[0024] On the other hand, while an interval control operation between successively-driven automobiles is carried out, such a fact is known. That is, a change in vehicle drive speeds rather than a change in the above-described intervals between the successively-driven vehicles may give a large influence to a comfortable driving condition.
[0025] As a consequence, in order that a vehicle speed of the own vehicle is smoothly controlled in response to a relative speed with respect to a preceding vehicle so as to improve such a comfortable driving condition, this relative speed should be measured in high resolution.
[0026] In the above-explained radar apparatus, as previously described, in order to improve the resolution “ΔV” of the velocity “vr”, the repetition period of the modulation should be set to the longer repetition period.
[0027] However, when the repetition period is made longer, the data updating period is lowered directly proportional to this long repetition period. As a result, there is a problem that the response characteristic of the radar detection operation is lowered.
[0028] In particular, generally speaking, in an automobile radar apparatus, while a radar beam is scanned, distances along a plurality of directions are measured so as to recognize a direction of a preceding vehicle. When data is updated one time, distances must be measured plural times in correspondence with a scanning direction.
[0029] As previously described, in the FM-CW radar apparatus, while the beat signal between the reflection signals is measured during the two modulation periods (namely, frequency-up modulation period and frequency-down modulation period), both the distance “R” and the velocity “vr” are measured. As a result, the time duration required for measuring the velocity “Vr” must become two times longer than the time duration required for measuring the Doppler signals.
[0030] For example, in such a radar apparatus having a center frequency “f 0 ” of 76.5 GHz, in order to measure a radar signal in resolution of such a relative speed (=0.5 km/h), such a time duration of “1/fm (=c/(f 0 ·Δv)=0.028s)” per one direction is required. Thus, a time duration of “5·1/fm (=0.14 s)” per 5 directions is needed, which is five times longer than the first-mentioned time duration of “1/fm”.
[0031] Normally, in order to measure an angle with higher precision, or to measure a wider range, the total number of scanning directions must be increased. This implies that measuring time duration is increased. In other words, this implies that a time duration required for a single scanning operation is increased. As a result, this may induce that the control response characteristic and the control performance of the FM-CW radar apparatus are deteriorated.
[0032] For example, in the conventional radar apparatus described in the above-explained Japanese Patent Application Laid-open No. 63-275976 (Japanese Patent No. 2550574), while both the upper side band signal and the lower side band signal are transmitted at the same time, the frequencies of which are repeated along the ascent direction and also the descent direction within a constant time period, both the distance “R” and the velocity “vr” of the object are measured from the frequency differences in the reflection signals.
[0033] The above-explained conventional radar apparatus is not directed to shortening of the measuring time. However, as a result, since the signal modulation is performed one time in order to measure the velocity, this conventional radar apparatus is in principle arranged in such a manner that the measuring time may be reduced by ½.
[0034] However, in this conventional radar apparatus, the reference oscillation signal (carrier wave) is mixed with the frequency modulation signal by the up-converter, and thereafter, both the upper side band signal and the lower side band signal are employed as the local signal. This local signal is used to extract the beat signals of the reflection waves and also the transmission waves. As a consequence, while the basic wave is suppressed, the upper side band signal must be completely separated from the lower side band signal.
[0035] To the contrary, in the millimeter band having the center frequency of 76 GHz employed in an automobile radar, the maximum occupied bandwidth is allowed only up to 1 GHz. Also, such a filtering technique could not be so far established, by which a practically operable filter having a sharp cut-off characteristic in the millimeter band is constructed. As a result, the above explained radar apparatus described in Japanese Patent Application Laid-open No. 63-275976 cannot be practically realized.
[0036] As described above, in the conventional FM-CW radar apparatus, when the repetition periods of the modulation operations are set to such long repetition periods in order to measure the relative velocity between the object and this radar apparatus in better resolution, the following problem may occur. That is, the data updating time period is lowered, so that the detection response characteristic is lowered.
[0037] Also, in such a case that this conventional FM-CW radar apparatus is applied to control the interval between the successively-driven vehicles, when the speed changes are controlled in the suppression mode in order to improve the comfortable driving condition, there is such a problem that the lengthy time is required to measure the velocity, and therefore, both the control response characteristic and the control performance would be lowered.
[0038] Also, as explained in the conventional radar apparatus of Japanese Patent Application Laid-open No. 63-275976 (Japanese Patent No. 2550574), in such a case that both the upper side band signal and the lower side band signal are transmitted at the same time, the frequencies of which are repeated along the ascent direction and also the descent direction within a constant time period, both the upper side band signal and the lower side band signal should be completely separated from each other, while completely suppressing the basic wave signal. Therefore, there is such a problem that this radar apparatus cannot be realized in such a frequency band which is used in the automobile radar apparatus.
SUMMARY OF THE INVENTION
[0039] The present invention has been made to solve the above-described problems, and therefore, has an object to provide such an FM-CW radar apparatus capable of reducing a physically-required radar signal measuring time duration by ½, while measuring means for measuring both a distance of an object and a velocity thereof by way of both a frequency-up modulation and a frequency-down modulation is applied thereto.
[0040] To achieve the above-explained object, an FM-CW radar apparatus according to the present invention is characterized by comprising: transmission means for separately producing a first FM modulation wave along a frequency-up direction and a second FM modulation wave along a frequency-down direction to transmit both the first FM modulation wave and the second FM modulation wave at the same time; reception means for receiving reflection waves reflected from an object, which are caused by the first and second FM modulation waves; beat signal detection means for detecting a first beat signal and a second beat signal in a separate manner between the reflection waves and the first/second FM modulation waves; and an analysis apparatus for analyzing frequency components of the first and second beat signals so as to measure a distance of the object and also a velocity of the object.
[0041] Also, the FM-CW radar apparatus according to the present invention is characterized in that a frequency of the first FM modulation wave and a frequency of the second FM modulation wave are set in such a manner that the frequencies thereof are not intersected with each other.
[0042] Further, the FM-CW radar apparatus according to the present invention is characterized in that a frequency of the first FM modulation wave and a frequency of the second FM modulation wave are set in such a manner that the frequencies thereof are intersected with each other in the vicinity of each of center frequencies of the first and second FM modulation waves.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] For a better understanding of the present invention, reference is made of a detailed description in conjunction with the accompanying drawings, in which:
[0044] [0044]FIG. 1 is a schematic block diagram for representing an arrangement of an FM-CW radar apparatus in accordance with Embodiment 1 of the present invention;
[0045] [0045]FIG. 2 is a waveform diagram for representing voltage signals which are outputted from both a saw-tooth waveform oscillator and an inverting amplifier employed in the radar apparatus of Embodiment 1 of the present invention;
[0046] [0046]FIG. 3 is an explanatory diagram for explaining a characteristic of each of voltage-controlled oscillators employed in the radar apparatus of Embodiment 1 of the present invention;
[0047] [0047]FIG. 4 is a waveform diagram used to explain operations of the radar apparatus in accordance with Embodiment 1 of the present invention;
[0048] [0048]FIG. 5 is a waveform diagram for representing voltage signals which are outputted from both a saw-tooth waveform oscillator and an inverting amplifier employed in an FM-CW radar apparatus of Embodiment 2 of the present invention;
[0049] [0049]FIG. 6 is a waveform diagram used to explain operations of the radar apparatus in accordance with Embodiment 2 of the present invention;
[0050] [0050]FIG. 7 is a waveform diagram for explaining the operations of the conventional FM-CW radar apparatus with respect to the stationary object; and
[0051] [0051]FIG. 8 is a waveform diagram for describing the operations of the conventional FM-CW radar apparatus with respect to the moving object.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] Embodiment 1
[0053] Referring now to drawings, an FM-CW radar apparatus according to Embodiment 1 of the present embodiment will be described in detail.
[0054] [0054]FIG. 1 is a schematic block diagram for representing an arrangement of an FM-CW radar apparatus according to an embodiment mode 1 of the present invention.
[0055] [0055]FIG. 2 is a waveform diagram for representing voltage signals which are outputted from both a saw-tooth waveform oscillator and an inverting amplifier employed in the radar apparatus of Embodiment 1.
[0056] [0056]FIG. 3 is an explanatory diagram for representing a relationship between an input signal level and an oscillation frequency of each of voltage-controlled oscillators employed in the radar apparatus of FIG. 1.
[0057] Also, FIG. 4 is a waveform diagram for representing the oscillation frequency of each of the voltage-controlled oscillators, a frequency of a reception signal (electromagnetic wave signal), and a frequency of a beat signal in the radar apparatus of FIG. 1.
[0058] In FIG. 1, there are shown: a saw-tooth wave oscillator 1 , an inverting amplifier 2 , a first voltage-controlled oscillator 3 , a second voltage-controlled oscillator 4 , a first coupling device 5 , a second coupling device 6 , a power synthesizing device 7 , a transmission antenna 8 , a target (object) 9 of a radar apparatus, a reception antenna 10 , a power distributing device 11 , a first frequency mixer 12 , a second frequency mixer 13 , a first low-pass filter 14 , and also a second low-pass filter 15 .
[0059] The first voltage-controlled oscillator 3 is connected to the saw-tooth wave oscillator 1 , and the second voltage-controlled oscillator 4 is connected via the inverting amplifier 2 to this saw-tooth wave oscillator 1 .
[0060] The first coupling device 5 derives a portion of the output signal of the first voltage-controlled oscillator 3 , and the second coupling device 6 derives a portion of the output signal of the second voltage-controlled oscillator 4 .
[0061] The power synthesizing device 7 synthesizes the output signal of the first coupling device 5 with the output signal of the second coupling device 6 , and the transmission antenna 8 radiates the signal power synthesized by the power synthesizing device 7 as electromagnetic waves.
[0062] The reception antenna 10 receives electromagnetic waves reflected from the target 9 , and the power distributing device 11 distributes the reception power of the reception antenna 10 into two signal systems.
[0063] The first frequency mixer 12 mixes the reception power distributed by the power distributing device 11 with the coupled power of the first coupling device 5 .
[0064] The second frequency mixer 13 mixes the reception power distributed by the power distributing device 11 with the coupled power of the second coupling device 6 .
[0065] The first low-pass filter 14 is connected to the output of the first frequency mixer 12 , and the second low-pass filter 15 is connected to the output of the second frequency mixer 13 .
[0066] Both the first low-pass filter 14 and the second low-pass filter 15 are connected to an analyzing apparatus (not shown) which is employed so as to measure both a distance of the target 9 , a velocity of this target 9 , and the like. The first and second low-pass filters 14 and 15 enter a beat signal “fbu” and another beat signal “fbd” to this analyzing apparatus.
[0067] Referring now to FIG. 1 to FIG. 4, a description is made of operations of the FM-CW radar apparatus according to Embodiment 1 of the present invention.
[0068] First, an output voltage waveform “Va” (see FIG. 2) of the saw-tooth wave oscillator 1 is applied to a voltage control terminal of the first voltage-controlled oscillator 3 , and also an output voltage waveform “Vb” of the inverting amplifier 2 is applied to a voltage control terminal of the second voltage-controlled oscillator 4 . This output voltage waveform “Vb” corresponds to an inverted waveform of the above-explained output voltage waveform “Va”.
[0069] A relationship between signal levels of the voltage signals entered into the voltage control terminals of the first and second voltage-controlled oscillators 3 and 4 , and oscillation frequencies of these oscillators is indicated in FIG. 3.
[0070] As apparent from the characteristic shown in FIG. 3, when the respective output voltage waveforms “Va” and “Vb” (see FIG. 2) are applied to the respective voltage-controlled oscillators 3 and 4 , the oscillation frequencies of the respective voltage-controlled oscillators 3 and 4 are changed, as indicated by solid lines “f 1 ” and “f 2 ” of FIG. 4, respectively.
[0071] In other words, the output signal (oscillation signal) of the first voltage-controlled oscillator 3 constitutes a modulation wave (modulation signal) along a frequency-ascent direction, whereas the output signal of the second voltage-controlled oscillator 4 constitutes a modulation wave (modulation signal) along a frequency-descent direction.
[0072] The output signals from the first and second voltage controlled oscillators 3 and 4 are penetrated through the first and second coupling devices 5 and 6 , and thereafter, are synthesized with each other by the power synthesizing device 7 , and then, the synthesized signal is radiated as electromagnetic waves from the transmission antenna 8 into the space.
[0073] The electromagnetic waves radiated into the space are reflected from the target 9 to produce reflection waves which will be received by the reception antenna 10 . This target 9 is located at a position which is separated from the FM-CW radar apparatus by a preselected distance.
[0074] At this time, the electromagnetic waves received by the reception antenna 10 are delayed by time “ ” which is defined by that the electromagnetic waves are reached from the transmission antenna 9 to the target 9 , and thereafter are returned to the reception antenna 10 .
[0075] As a consequence, frequencies of the received electromagnetic waves are delayed by time“ ” and are changed, as indicated by broken lines “fr 1 ” and “fr 2 ” in FIG. 4.
[0076] The electromagnetic waves received by the reception antenna 10 are equally distributed by the power distributor 11 , and the equally-distributed electromagnetic waves are entered into the first and second frequency mixers 12 and 13 , respectively.
[0077] The respective first/second frequency mixers 12 and 13 mix the distributed reception electromagnetic waves with a portion of the output signals of the respective first/second voltage-controlled oscillators 3 and 4 , which are supplied from the first and second coupling devices 5 and 6 , so that these first and second frequency mixers 12 and 13 produce both a difference signal (namely, beat signal) and a summation signal between the transmission frequency and the reception frequency.
[0078] The respective first/second low-pass filters 14 and 15 extract only such low-frequency beat components within the pass-band bandwidths of these first/second low-pass filters 14 and 15 from the output signals derived from the respective first/second frequency mixers 12 and 13 . Then, these low-pass filters 14 and 15 output these low frequency beat components.
[0079] The beat signal “fbu” outputted from the first low-pass filter 14 corresponds to such a difference signal between the modulation wave along the frequency-up (ascent) direction outputted from the first voltage-controlled oscillator 3 and a reflection wave of this modulation wave, and the frequency of this first beat signal “fbu” is changed, as represented in FIG. 4.
[0080] At this time, the output signal of the first frequency mixer 12 also contains another difference signal (beat signal) between the modulation wave along the frequency-up direction, which is outputted from the first voltage-controlled oscillator 3 , and a reflection signal made by the modulation wave along the frequency-down (descent) direction, which is outputted from the second voltage-controlled oscillator 4 .
[0081] However, the frequency of the beat signal contained in the output signal from the first frequency mixer 12 is substantially equal to a difference between the modulation wave along the frequency-up direction and the modulation wave along the frequency-down direction, and therefore, is very high. As a result, since this high frequency of the beat signal is located outside the pass-band of the first low-pass filter 14 , this beat signal is not derived from the first low-pass filter 14 .
[0082] Similarly, the beat signal “fbd” outputted from the second low-pass filter 15 corresponds to such a difference signal between the modulation wave along the frequency-down (descent) direction outputted from the second voltage-controlled oscillator 4 and a reflection wave of this modulation wave, and the frequency of this second beat signal “fbd” is changed, as represented in FIG. 4.
[0083] The beat signals which are extracted from the respective first/second low-pass filters 14 and 15 in the above-explained manner are sampled, respectively, and then, the sampled beat signals are analyzed by the analyzing apparatus by way of the FFT frequency analysis manner. As a consequence, the analyzing apparatus can simultaneously detect both the beat frequency “fbu” of the reflection wave which is reflected from the target 9 and is caused by the modulation wave along the frequency-up direction, and also, the beat frequency “fbd” of the reflection wave which is reflected from the target 9 and is caused by the modulation wave along the frequency-down direction.
[0084] Subsequently, similarly to the calculation case of the conventional radar apparatus, both a distance “R” of the target 9 and a velocity “vr” of this target 9 may be calculated from the beat frequencies “fbu” and “fbd”.
[0085] Note that, in this case, since the repetition frequency “fm” of the FM modulation becomes two times higher than the repetition frequency of the FM modulation in the conventional radar apparatus, both the distance “R” and the velocity “vr” of the target 9 are expressed by the below-mentioned equation (10) by employing such a value obtained by dividing the repetition frequency “fm” by 2.
R= ( fbd−fbu )× c /8/( fm/ 2)/Δ F
vr= ( fbd+fbu )× c/ 4/ f 0 (10)
[0086] As previously described, while both the modulation wave along the frequency-up direction and the modulation wave along the frequency-down direction, which are produced from the individual voltage-controlled oscillators 3 and 4 , are transmitted at the same time, the beat signals between each of the modulation waves and the reflection signals are measured at the same time. Then, the reflection signal caused by the frequency-up modulation wave component, and also the reflection signal caused by the frequency-down modulation wave component, which are contained in the reflection signals, are separated/detected. As a result, the respective beat frequency components are analyzed so as to calculate both the distance “R” and the velocity “vr” of the target 9 .
[0087] As a consequence, the FM-CW radar apparatus can measure both the distance “R” and the velocity “vr” of the target 9 within such a short measuring time duration equal to ½ of the measuring time duration of the conventional radar apparatus, while both the distance resolution and the velocity resolution are not deteriorated.
[0088] Also, when an automobile collision preventing apparatus and/or a control apparatus for controlling an interval between successively-driven vehicles are arranged by employing the radar apparatus according to Embodiment 1, the automobile control operations can be carried out within a half of the time period for the conventional radar apparatus. As a result, it is possible to realize such a more safety radar apparatus with high performance.
[0089] Also, since the distance/velocity measurement can be carried out within ½ of the conventional measuring time duration, the radar apparatus of this embodiment mode 1 can measure such a wider range than that of the conventional radar apparatus by increasing a total number of scanning directions two times. As a consequence, this radar apparatus can detect obstacles located along the multiple directions and also travel-path-interrupting vehicles appeared near the own vehicle earlier, so that the safety characteristics as to the collision preventing control and the control operation for controlling the successively-driven vehicles can be improved.
[0090] Also, since the measuring operations as to the modulation waves along the frequency-up direction and the frequency-down direction are carried out at the same time, the Doppler measuring operation may be accomplished only by the modulation one time. As a result, the measurement having the same velocity resolution can be realized within ½ of the measuring time duration of the conventional radar apparatus.
[0091] Furthermore, since the FM modulation wave along the frequency-up direction and the FM modulation wave along the frequency-down direction are separately produced by the individual first/second oscillation means 3 and 4 , both the carrier wave and the side band signal along the reverse direction are no longer suppressed. Accordingly, the FM-CW radar apparatus can be readily realized.
[0092] Embodiment 2
[0093] It should be understood that in the above-described Embodiment 1, the FM-CW radar apparatus is arranged in such a manner that the frequency of the modulation wave along the frequency-up direction is not intersected (overlapped) with the frequency of the modulation wave along the frequency-down direction. Alternatively, the oscillation frequencies of the respective voltage-controlled oscillators 3 and 4 may be modulated in such a manner that the respective frequencies of the modulation waves are intersected with each other.
[0094] Subsequently, an FM-CW radar apparatus according to an embodiment mode 2 of the present invention will now be explained, which is arranged in such a manner that frequencies of respective modulation waves are intersected with each other.
[0095] In this case, the arrangement of this FM-CW radar apparatus is similar to the above-explained arrangement (see FIG. 1).
[0096] [0096]FIG. 5 is a waveform diagram for representing an output voltage waveform “Va 1 ” of a saw-tooth wave oscillator 1 , and also an inverted voltage waveform “Vb 1 ” thereof, employed in the FM-CW radar apparatus according to Embodiment 2 of the present invention.
[0097] [0097]FIG. 6 is a waveform diagram for showing oscillation frequencies of voltage-controlled oscillators 3 and 4 , a frequency of a reception signal, and also a frequency of a beat signal, appeared in the FM-CW radar apparatus of Embodiment 2.
[0098] In the case that the output voltage waveforms “Va 1 ” and “Vb 1 ” shown in FIG. 5 are inputted into the respective first/second voltage-controlled oscillators 3 and 4 , the oscillation frequencies of the respective voltage-controlled oscillators 3 and 4 are changed as represented by solid lines “f 11 ” and “f 21 ” in FIG. 6, based upon the frequency characteristic indicated in FIG. 3.
[0099] Similarly, in this case, frequencies of the reception electromagnetic waves are delayed by time “ ” as represented in broken lines “fr 11 ” and “fr 21 ” in FIG. 6.
[0100] An output signal of the first frequency mixer 12 contains a difference signal (namely, beat signal to be measured) of reflection signals reflected from the target 9 , which are caused by the modulation wave along the frequency-up direction (frequency-ascent direction) outputted from the first voltage-controlled oscillator 3 , and also this output signal contains another difference signal (namely, beat signal) of reflection signals which are caused by the modulation wave along the frequency-down direction (frequency-descent direction) outputted from the second voltage-controlled oscillator 4 .
[0101] Normally, a beat signal component (which is substantially coincident with difference between modulation wave along frequency-up direction and modulation wave along frequency-down direction) is very large. However, in such a case that the frequency of the modulation wave along the frequency-up direction is made substantially equal to the frequency of the modulation wave along the frequency-down direction, a frequency of a beat signal becomes low, and thus, is located within the pass band of the first low-pass filter 14 .
[0102] As a consequence, as indicated by a broken line of FIG. 6, the frequency of the beat signal “fbu” outputted from the first low-pass filter 14 is changed in a temporal manner.
[0103] As explained above, since the beat frequency is instantaneously changed, when this beat signal “fbu” is sampled and then analyzed by way of the FFT frequency analysis, the components of the beat signal “fbu” are uniformly distributed within the analyzing frequency range, which is equivalent to such a fact that white noise is superimposed with the beat signal “fbu”.
[0104] As a consequence, this fact never produces other beat frequency components, but also does not give an adverse influence to the beat frequency of the reflection wave reflected from the target 9 , which is caused by the modulation wave along the frequency-up direction.
[0105] Similarly as indicated by a broken line of FIG. 6, the frequency of the beat signal “fbd” outputted from the second low-pass filter 15 is changed in a temporal manner.
[0106] At this time, noise equivalent to white noise is superimposed with this beat signal “fbd”. However, electric power of this noise is equal to such a value obtained by dividing the band width of the second low-pass filter 15 by the frequency modulation width. Since this noise power is very small, namely is on the order of {fraction (1/1000)} with respect to the electric power of the reflection wave, there is no practical problem.
[0107] Also, in the above-described radar apparatus of Embodiment 1, since this radar apparatus is arranged in such a manner that the frequency of the modulation wave along the frequency-up direction is not intersected, or overlapped with the frequency of the modulation wave along the frequency-down direction, the modulation wave bandwidth of this radar apparatus should be made at least two times wider than that of the conventional radar apparatus. In the radar apparatus of Embodiment 2, this radar apparatus is arranged in such a manner that the frequencies of the respective modulation waves are overlapped with each other. As a result, since the modulation wave bandwidth of this radar apparatus may be made substantially equal to that of the conventional radar apparatus, this radar apparatus may effectively utilize the frequency range which is defined by the Japanese Radio Law.
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In an FM-CW radar apparatus, while a distance and velocity of a target are measured by simultaneously transmitting an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction toward this target, physically-required radar signal measuring time thereof can be reduced by ½. The FM-CW radar apparatus is arranged by employing: a transmission unit for separately producing a first FM modulation wave along a frequency-up direction and a second FM modulation wave along a frequency-down direction to transmit both the first FM modulation wave and the second FM modulation wave at the same time; a reception unit for receiving reflection waves reflected from an object, which are caused by the first and second FM modulation waves; a beat signal detection unit for detecting a first beat signal and a second beat signal in a separate manner between the reflection waves and the first and second FM modulation waves; and an analysis apparatus for analyzing frequency components of the first and second beat signals so as to measure a distance of the object and also a velocity of the object.
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BACKGROUND OF THE INVENTION
The general field of the invention is that of mobile vehicles and, more particularly, those vehicles known as unicycles. In the general field of unicycles there are those which are operated by movable pedals which the rider moves in circular paths with his feet, and others which are operated by power, and the invention relates to unicycles of the latter type.
SUMMARY OF THE INVENTION
The invention provides a unicycle wheel having a fixed unit with external diametrically extending fixed pedals thereon on which the rider stands, a rotatable ground engaging unit which with the fixed unit forms a hollow body, power operated means for rotating the rotatable unit disposed within the hollow body and being operative by movement of the pedals to control the direction and speed of rotation of the rotatable unit and therefore the movement of the vehicle on the ground surface.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a horizontal diametrical view, partly in section, of the unicycle wheel provided by the invention;
FIG. 2 is a side elevational view of the unicycle wheel, and
FIG. 3 is a sectional view taken on line 3--3 of FIG. 2 showing the driving means in elevation and including a circuit diagram of the means for energizing the driving means.
DESCRIPTION OF THE INVENTION
The unicycle wheel comprises a hollow body having a fixed unit having laterally spaced pedals which supports the rider, and a rotatable ground-engaging unit which is mounted on the fixed unit. The fixed unit comprises a circular plate 2 having a pedal 4 fixed to its outer surface and extending diametrically thereof and a shaft 6 which extends at a right angle to the plate from the center of the plate in the direction away from pedal 4, and has second pedal 8 mounted on its outer end. The rotatable unit of the wheel comprises a cup-shaped body having a flat, circular bottom 10 which is parallel to and spaced from the fixed plate 2 at a position just inboard the pedal 8. A cylindrical peripheral wall 12 extends from the bottom plate 10 toward fixed plate 2 and terminates in a peripheral edge adjacent the periphery of the fixed plate. The fixed and rotatable units form a hollow body having a rotatable peripheral wall 12 which engages the ground surface in the use and operation of the unicycle wheel and having normally horizontally disposed co-planar pedals on the opposite sides of the hollow body on which the rider stands. The pedals and plate 2 are mounted for fore-and-aft rocking movement with respect to the rotatable unit, as illustrated in FIG. 2 and as will be described more fully. The rotatable unit is rotatably mounted on shaft 6 by means of a cylindrical hollow shaft 12 which extends inwardly of the hollow body from the center of plate 10 in surrounding relation to fixed shaft 6 and on its outer end, within the hollow body, has an integrally formed gear wheel 14 having external peripheral teeth 16. A bearing sleeve 18 is interposed between shafts 6 and 12. A cylindrical hollow shaft 19 extends inwardly of the hollow body from the center of the fixed plate 2 and at its outer end engages the external wall of gear wheel 14 to add stability to the entire unit.
Means are provided by the invention for causing rotation of the rotatable unit on and with respect to the fixed unit, and such means comprise a reversing electric motor 30 having armature 32 on which a helical gear 34 is provided which meshes with the peripheral teeth 16 on gear wheel 14. It will be apparent that energization of motor 30 will cause rotation of the rotatable unit through the described gearing, with consequent movement of the unicycle along the ground surface.
Means are provided within the hollow wheel for energizing the motor 30 in two directions of rotation in order to move the vehicle forward and reversely. Such means are particularly disclosed in FIG. 3 of the drawings and comprise a switch contact rod 40 which is connected to the shaft 6 and extends vertically upwardly therefrom and may therefore rock with that shaft. Above the shaft 6 the rod 40 is provided with a ring switch contact member 42 which is insulated from rod 40 and adjacent which fixed switch contacts 44, 46 are mounted on the inner surface of the fixed plate 2. An annular spring 48 tightly surrounds shaft 19, and is therefore attached to fixed disc 2, and has spaced inturned ends which engage the opposite sides of switch contact rod 40 and normally maintain the rod in centered position with its contact member 42 out of engagement with fixed contacts 44, 46.
The means and circuitry for energizing the driving motor 30 and controlling its direction and speed of rotation will now be described. A battery assembly 50 is provided within the hollow wheel and is mounted on fixed plate 2 and has positive and negative terminals. The control rod 40 is provided above contact member 42 with an exterior layer of insulating material and on this is laid a helical resistor wire 52. Two arcuate metal contact members 54, 56 are positioned on opposite sides of contact rod 40 and are mounted on fixed plate 2 at their upper ends and extend downwardly and inwardly with respect to the contact rod with their lower ends in contact with resistor wire 52 so that as the pedals, plate 2 and the contact rod 40 are moved angularly a moving tangential contact is established which is progressively higher on the resistor wire as the angle of movement of the pedals, plate and contact rod increases.
Fixed contacts 44, 46 are connected, respectively, to contact members 56, 54 by leads 58, 60. The positive terminal of battery 50 is connected to movable contact member 42 by lead 62 and the negative terminal is connected to the outer end of resistor wire 52 by lead 64. The positive terminal of motor 30 is connected to contact member 56 by lead 66 and the negative terminal is connected by lead 68 to fixed switch contact 46.
In the use and operation of the unicycle wheel the operator places the wheel in an upright position with the exterior surface of flange 12 on the ground surface and the pedals horizontal and their foot engaging surfaces upward. The operator now mounts the vehicle with his feet resting on the pedals and, for example, tilts the pedals forwardly as shown at A in FIG. 2, causing shaft 6 to rock slightly carrying with it the switch contact rod 40, which moves in the direction of the "forward" arrow in FIG. 3. Switch contacts 42, 44 are engaged and resistor wire 52 on contact rod 40 engages elongated contact member 54. A circuit is now established from the positive terminal of battery 50, through lead 62, movable contact 42, fixed contact 44, lead 58, lead 66, the positive and negative terminals of motor 30, lead 68, fixed switch terminal 46, lead 60, contact member 54, resistor wire 52 and lead 64 to the negative battery terminal. As the angular movement of the pedals is increased the point of contact between resistor winding 52 and contact member 54 will progressively move outwardly along rod 40, thus progressively decreasing the length of the resistor winding in circuit and thus progressively increasing the speed of rotation of motor 30 and the speed of movement of the wheel along the ground.
For reverse movement of the wheel the pedals are rocked in the direction of arrow B in FIG. 2, completing the following circuit which causes reverse rotation of the reversing motor 30. From the negative terminal of battery 50, lead 64, resistor winding 52, contact member 56, lead 66, the positive and negative terminals of motor 30, lead 68, fixed switch contact 46, switch contact 42 and lead 62 to the positive battery terminal.
It will be understood that the fixed switch contacts 44, 46 are mounted on plate 2 by means which yield under pressure of movable contact 42 as the pedals are rocked to actuate the mechanism.
A recharging outlet 70 is provided on plate 2 and is connected to the terminals of battery 50 by leads 72, 74.
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A unicycle wheel has a fixed unit having fixed pedals on either side thereof on which the operator stands, and a rotatable ground engaging unit mounted on the fixed unit and forming a hollow body with it. Drive means are mounted within the hollow body together with means operated upon forward or rearward tilting of the pedals by the operator to rotate the wheel in either direction and to control its speed of movement in response to the degree of tilting.
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FIELD OF THE INVENTION
[0001] The field of the invention is locks for downhole tools that can selectively retain the tool in a position for a particular operation and more particularly locks that can be released and subsequently reset for holding a downhole tool for subsequent operations.
BACKGROUND OF THE INVENTION
[0002] There are many types of tools used downhole. Some tools are moved repeatedly between positions for the performance of different operations. While these tools are designed to shift between the positions to accomplish downhole functions, the procedures downhole vary with time and tools that readily performed functions in multiple positions reveal a potential shortcoming. One such shortcoming can be the inability to retain a desired position throughout the duration of a particular downhole operation. In the past, locking the tool in a particular position has been tried, but those attempts created additional operating limitations. Some locks were effective against pressure variations but were not effective in resisting mechanical impacts. Some locks, when actuated hydraulically, permanently held a position of the downhole tool and could not be released.
[0003] What was needed was a lock for a downhole tool that could fix its position for a time to allow a certain procedure to take place and that could thereafter be released to allow the tool to operate in its various positions for other purposes.
[0004] The context that suggested such a desired lock assembly was a downhole tool known as a downhole valve and more specifically a model ‘RB’ Valve offered by Baker Hughes Incorporated. This downhole valve featured a J-slot mechanism between a sleeve and a mandrel. Pressure in the tubing could be cycled back and forth enough times to operate the J-slot mechanism until the mandrel, upon relief of applied pressure after a predetermined amount of cycles, could move a certain distance to allow the valve to go to the open position. In this example the valve was a ball that rotated 90°. Since this valve was actuated with pressure cycles in the tubing, it could be affected by pressure spikes in the tubing. Also, it was susceptible to mechanical impacts on the mandrel that could operate the valve out of the desired position for a specific procedure. One way this could happen is a tool string running through the mandrel could drag it to the next indexing position. Competing valves that operated on hydraulic cycling in combination with a J-slot mechanism would allow the valve to go to the open position and be locked there, but the lock was permanent so the valve could not later be closed.
[0005] Some operators, particularly in deep water, have high cost completions that need a lock that can be reset to allow injection of fluids through an open valve at high rates without concern that such a procedure will operate the valve out of an open position. Additionally, such a re-settable lock could accommodate tool strings with tight clearances to pass through without risk of moving the valve out of the desired position. Such a lock would then allow the valve position to be shifted when the specific operation that required the valve position to be locked is concluded.
[0006] Those skilled in the art will more readily appreciate the multiple applications of the described preferred embodiment below in a variety of downhole applications. In the preferred embodiment, the lock can hold members that otherwise move relatively with respect to each other when the tool changes positions to perform different functions. The relative movement can occur in one or more directions.
[0007] Many tester valves operate with annulus pressure cycles and are not vulnerable to tubing pressure spikes. The ‘RB’ Valve has some similar operating characteristics to tester valves except that it cycles on application of tubing pressure. Tester valves with J-slot mechanisms are illustrated in U.S. Pat. No. 4,667,743. A hydraulically triggered resetting lock for a tester valve that selectively disables the drive system for the mandrel is shown in U.S. Pat. No. 5,518,073. In this device, the valve can stay in the open position even with subsequent pressure cycling that can unintentionally occur. The mandrel is not mechanically restrained, rather, it is simply temporarily disabled from being further actuated by applied pressure until the drive system is again enabled. Also of related interest are U.S. Pat. No. 4,403,659 and U.S. application 2002/0066573. U.S. application 2002/0112862 shows a tester valve that can be cycled a predetermined number of times before it locks permanently closed. One way this occurs is a ratchet lock as shown in FIG. 10 and another is with a collet that can jump a hump in only a single direction as shown in the lower end of the split view in FIG. 20 .
[0008] Also of interest is U.S. Pat. No. 3,762,471 that uses dual control lines and a rotating ball in a subsurface safety valve that may be locked open when a sleeve attached to the ball is forced to move under hydraulic pressure so that the ball moves into the open position and a latch is also forced by hydraulic pressure to move to lock a detent into a recess. The lock can be released by pressure applied to different ports to liberate the detent from the recess. This complex design requires two control lines and due to its complexity was difficult to manufacture economically and was not commercially successful. It also required independent movement of a latch apart from the member that operates the ball to the open position to accomplish the locking. Also related to this design is U.S. Pat. No. 4,550,780 that featured a ball type subsurface safety valve that could be locked open and released. This valve was capable of being unlocked by pressure applied to the tubing and for that reason could be subject to being unlocked by unexpected pressure surges in the tubing. Locking also required the insertion of a bridge. plug.
SUMMARY OF THE INVENTION
[0009] The lock allows two members in a downhole tool to be temporarily held together. In an application where mandrel movement is dictated by pressure cycling in combination with a J-slot mechanism, such as in a downhole valve, the mandrel is releaseably retained to an adjacent connector against mechanical impacts. The mandrel features an extended collet that moves relatively to a floating sleeve during pressure cycles. At some point the collet heads rise to an elevated groove that causes them to contact a no-go shoulder for locking. The lock is defeated be removing the collet heads from the elevated groove for normal tool operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1 a - 1 b are a sectional view of the lock components with the downhole tool, in this example a valve, in the closed position;
[0011] FIGS. 2 a - 2 b are the view of FIG. 1 with the valve still closed but with pressure applied during an intermediate cycle;
[0012] FIGS. 3 a - 3 b are the view of FIG. 2 with the pressure removed but the valve is still closed;
[0013] FIGS. 4 a - 4 b are the view of FIG. 3 with pressure reapplied causing the collet heads to jump from the upper groove to the lower groove and pass over the raised groove;
[0014] FIGS. 5 a - 5 b show the pressure removed to put the valve in the open position and secure the lock with the collet heads on the raised groove; and
[0015] FIGS. 6 a - 6 g show a split view of an ‘RB’ Valve using the lock of the present invention with the valve open and locked on one side and at the instant of release on the other.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The drawings illustrate the resetting lock mechanism in detail and omit most of the details of the operation of a tester valve that are known. While an ‘RB’ valve is used for illustrative purposes, the present invention can be deployed in a downhole application where it is desired to hold one member to another during a specific downhole operation and to allow the downhole tool to resume other operations at a later time.
[0017] In the preferred embodiment, the invention is deployed in an ‘RB’ Valve. Such a valve is frequently attached to a packer and employs a j-slot mechanism, which is cycled by virtue of alternating application and removal of pressure downhole. In the preferred embodiment, pressure cycling occurs in the tubing and the pressure cycles, after a predetermined number of cycles, allows a mandrel 10 to shift with respect to a stationary surrounding connector 12 so that the net result can be an alignment or misalignment of ports to selectively open or close the downhole valve. In normal operations of the downhole valve a certain number of pressure cycles will advance a pin in a J-slot, effectively shifting the mandrel 10 up and down each time but not far enough to change the valve position. In the preferred embodiment, the pressure cycles need to be repeated a predetermined number of times before release of the pressure will allow the valve to open. At this point the mandrel stays in the open position and is insensitive to pressure cycles in the tubing from subsequent operations. However, without the lock of the present invention such a valve was still susceptible to closing from mechanical impacts resulting from subsequent downhole operations through the mandrel. If it was possible to build a tubing/annulus pressure differential with the valve open, without the present invention, such as might occur if injecting through the valve at high flow rates, then the valve might partially close. At the same time, prior solutions that automatically locked a hydraulically functioned J-slot type downhole valve proved to be of limited use due to their inability to be re-closed. Accordingly, in the preferred embodiment, the lock provides the versatility of locking in the open position and preferably automatic lock actuation when achieving that position in combination with the ability to unlock so the valve can be returned to normal function where it can be closed and opened any number of times as conditions downhole require.
[0018] The workings of the lock of the present invention can be seen starting with FIG. 1 . The mandrel 10 is operated by the J-slot mechanism (not shown) to move up and down. Those skilled in the art will appreciate that the mandrel 10 has a central axis 14 and it moves up and down responsive to pressure cycles, preferably in the annular space above the packer or other seal (not shown). The mandrel 10 is operated by a set of pistons and reciprocates but does not rotate. The reciprocating movement is controlled by a rotating sleeve with pins that travel in a J-slot pattern in the mandrel. 10 . Attached to mandrel 10 at thread 16 is a collet ring 18 that has extending collet fingers 20 with each finger 20 having a collet head 22 . The collet ring 18 is biased uphole by a spring 42 . While the mandrel is mounted so that it can reciprocate responsive to applied pressure cycles, the surrounding connector 12 is fixedly mounted from the packer or seal above (not shown). Mounted between the connector 12 and the mandrel 10 is sleeve 26 . The upper travel limit of sleeve 26 is defined by ring 28 attached at thread 30 to connector 12 . The lower travel limit of sleeve 26 happens when a protrusion 32 also known as a no-go and which extends in a direction away from the axis 14 contacts a no-go 34 on connector 12 that is pointing toward the axis 14 . Because of the connection at thread 16 the collet heads 22 move in tandem with mandrel 10 . However, relative movement between the sleeve 26 and the mandrel 10 is possible if the sleeve is restrained by contact of no-go 32 with no-go 34 .
[0019] Sleeve 26 has an upper groove 36 , a lower groove 38 and a raised groove 40 between them. The collet heads 22 can travel past no-go 34 when they are aligned with either grooves 36 or 38 . However, when the collet heads are aligned with raised groove 40 they can't clear no-go 36 . When this happens, the lock L is operational. The lock L can be defeated by using a tool to liberate the mandrel 10 to move uphole under the force of spring 42 .
[0020] It should be noted that sleeve 26 differs in design between the version shown in FIGS. 1-5 and that shown in FIG. 6 . The design in FIG. 6 shows a greater wall thickness under raised groove 40 and is used primarily in the larger sizes. The added wall thickness is for added strength to deal with the anticipated loads imposed from collet heads 22 to prevent the sleeve 26 from deforming in that location under load. This feature is not found in the sleeve design of FIGS. 1-5 because in the smaller sizes the loads are lower thus avoiding the need for increasing the wall thickness under the raised groove 40 .
[0021] Sleeve 26 is thicker at upper end 44 to give it strength against impact loads on the mandrel 10 with the no-go shoulders 32 and 34 in contact. Additionally, sleeve 26 has a small diameter 46 that extends into recess 48 to guide the movement of sleeve 26 and to prevent it from contorting if no-go shoulders 32 and 34 contact violently.
[0022] The operation of the lock L will now be described in detail. In FIG. 1 the tester valve (not shown) is in the closed position and no pressure is applied to the tubing. The sleeve 26 is against ring 28 and the collet heads 22 are in groove 36 .
[0023] The procedure for opening the valve requires cycles of pressure to the tubing. In a particular design it may take 11 cycles of pressure where each time pressure is applied the lock L will go into position as shown in FIG. 2 . In FIG. 2 , the mandrel 10 has shifted down compared to the FIG. 1 position. The collet heads 22 remain in upper groove 36 , as there has been no relative movement between the mandrel 10 and the sleeve 26 . The collet heads 22 have cleared no-go 34 on the connector 12 .
[0024] When the pressure is released in each of the 11 cycles referred to above, springs 42 and 58 urge the mandrel 10 uphole and up with it go the collet heads 22 still in upper groove 36 . The collet heads do not rise above no-go 34 but as previously mentioned, when they are in groove 36 they are capable of clearing no-go 34 .
[0025] FIG. 4 shows what happens on the last cycle (cycle 12, in the preferred embodiment) where the downhole valve will open. In the first part of this cycle, the tubing pressure is applied forcing the mandrel 10 down. This time the J-slot mechanism (not shown) allows the mandrel 10 to move down further than before. The excess movement of mandrel 10 also means that collet heads 22 move a similar amount. However, the no-goes 32 and 34 contact, preventing downward movement of sleeve 26 . As a result the collet heads 22 are pulled down with respect to sleeve 26 until they land in lower groove 38 . The collet heads 22 have jumped over the raised groove 40 .
[0026] When the tubing pressure is released, the J-slot mechanism (not shown) will let the mandrel move uphole under the force of spring 42 . The collet heads 22 stay in the lower groove 38 taking the sleeve 26 uphole with mandrel 10 . Eventually, after collet heads 22 clear the no-go 34 , the sleeve 26 comes up against ring and its upward movement is stopped. However, in this cycle, the J-slot mechanism (not shown) lets the mandrel 10 keep moving up to expand the collet heads 22 apart as they jump up on raised groove 40 . This is the position shown in FIG. 5 . In this position, the mandrel has moved up enough to open the valve (not shown) and the mandrel 10 is precluded from moving down because collet heads 22 will not clear no-go 34 when on raised groove 40 . At the same time, spring 42 keeps the mandrel 10 from moving uphole as the spring force keeps mandrel 10 up against a stop (not shown).
[0027] The lock L, in the preferred embodiment, is automatically triggered as the downhole valve goes into the open position. The lock L can be defeated by inserting a tool that extends the mandrel 10 by shifting dogs (not shown) in a manner that lets the lower end of mandrel 10 (not shown) be forced down to close the valve while allowing the portion of mandrel 10 shown in FIG. 5 be biased up by spring 42 with collet heads 22 moving relatively to sleeve 26 so that the collet heads 22 go into upper groove 36 so that the position of FIG. 1 is resumed. The downhole valve can now be cycled the 12 times mentioned before to get it to open and lock open as described above.
[0028] The release procedure is illustrated in an ‘RB’ valve shown in FIG. 6 . FIG. 6 is a split view showing the ‘RB’ valve locked open on one side and at the instant of release on the other. The release is accomplished by an inserted release tool T, shown schematically in the release position as T′, that grabs dog 50 shown in FIG. 6 c and moves it to a position 50 ′. When that happens, a collet 52 in FIG. 6 d loses support from sleeve 54 when it moves up with dog 50 . The lower portion 56 of mandrel 10 now can be biased down by spring 58 push down the actuating mechanism 60 to rotate ball 62 into the closed position from the open position shown in FIG. 6 f. At the same time, because collet 52 is undermined, the upper portion 62 of mandrel 10 can be pushed up by spring 42 far enough so that collets 22 can return to upper groove 36 . This amount of upward movement is permitted by the J-slot assembly 64 . Other release techniques are also envisioned. It should be noted that spring 24 causes collet 52 to be subsequently captured by sleeve 54 as the J-slot mechanism 64 is thereafter cycled to begin the process of reopening the valve.
[0029] Those skilled in the art can appreciate that the lock L can be used in a variety of applications downhole where it is desired to temporarily hold a movable member in one position relative to a fixed member. The movable member can be actuated in a variety of ways and can exhibit longitudinal movement, rotational movement or a combination of such movements. The lock can be triggered to come on at predetermined positions of the moving member. This can be made to occur at either extreme of the movement range of the movable member or any point or points in between. The lock L can be automatically deployed at a predetermined position. The lock can preferably be released in a variety of ways and preferably in a non-destructive manner, which will allow it to function again without a trip out of the hole. The lock L is preferably of simple construction to assure reliable operation even in hostile environments. In the preferred embodiment, it requires no pistons or additional seals to be operative. In preferred embodiment, the locking can occur either without rotation of the locking components or, if there is rotation, the locking can occur independently of the degree of rotation of any of the components. While the lock L is particularly suitable for temporarily locking open a downhole valve automatically when it reaches an open position, it can be used in other ways on tester valves or other downhole tools, as partially described above.
[0030] The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the invention.
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The lock allows two members in a downhole tool to be temporarily held together. In an application where mandrel movement is dictated by pressure cycling in combination with a J-slot mechanism, such as in a downhole valve, the mandrel is releaseably retained to an adjacent connector against mechanical impacts. The mandrel features an extended collet that moves relatively to a floating sleeve during pressure cycles. At some point the collet heads rise to an elevated groove that causes them to contact a no-go shoulder for locking. The lock is defeated be removing the collet heads from the elevated groove for normal tool operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a U.S. 371 national stage entry of pending International Patent Application No. PCT/US2008/056252, filed Mar. 7, 2008, which claims priority to U.S. Provisional Application 60/906,012, filed Mar. 9, 2007, all of which are herein incorporated by reference in their entireties.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with government support under grant no. 1P20GM069985-01 awarded by the National Institute of General Medical Sciences. The government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention provides methods and compositions for establishing and maintaining growth of undifferentiated stem cells, such as embryonic stem cells. In particular, the present invention provides synthetic growth matrices for stem cells, wherein said cells are capable of going through multiple passages while remaining in an undifferentiated state.
BACKGROUND OF THE INVENTION
Human and other mammalian stem cells including embryonic stem cells (hESCs and ESCs), which are pluripotent cells derived from pre-implantation embryos, have enormous potential as predicative models of early development or for cell replacement therapies (Draper et al., 2004, Stem Cells & Devel. 13:325-336). Because hESCs show remarkable sensitivity towards environmental influences, their continuous undifferentiated growth has been a major challenge undermining widespread use of hESCs in many applications. Currently, sustained hESC cultures still require naturally-derived cell substrates, such as mouse or human embryonic fibroblast cells, MATRIGEL, laminin, or fibronectin (Draper et al. 2004; Stojkovic et al., 2005, Stem Cells 23:306-314; Xu et al., 2001, Nat. Biotech. 19:971-974; Mallon et al., 2006, Int. J. Biochem. Cell Biol. 38:1063-1075; Amit et al., 2004, Biol. Repro. 70:837-845; Amit et al., 2003, Biol. Repro. 68:2150-2156; Skottman et al., 2006, Reproduction 132:691-698; Thomson et al., Science 282:1145-1147; Ellerstrom et al., 2006, Stem Cells 24:2170-2176; Xu et al., 2001, Nat. Biotechnol 19:971-974; Cheon et al., 2006, Biol. Reprod. 74:611; Beattie et al., 2005, Stem Cells 23:489-495).
However, xenogenic culture matrices are associated with several shortcomings. While co-culture systems with fibroblasts complicate direct studies of self-renewal and/or differentiation mechanisms of hESCs, cell substrates based on MATRIGEL and other naturally derived matrices show batch-to-batch inconstancies and may be prone to contaminations. To address these challenges, synthetic polymers have been proposed as cell culture substrates of hESC, because of their well-defined and reproducible fabrication, but have not yet been established for long-term hESC cultures.
As such, what are needed are compositions and methods that provide an environment for growth and maintenance of embryonic stem cells. The establishment of defined microenvironments for stem cell culture addresses a major issue of human embryonic stem cell research, and will provide embryonic stem cells useful in, for example, research purposes and potential clinical treatments of diseases.
SUMMARY OF THE INVENTION
The present invention provides methods and compositions for establishing and maintaining growth of undifferentiated stem cells. In particular, the present invention provides synthetic growth matrices for stem cells, wherein said cells are capable of going through multiple passages while remaining in an undifferentiated state.
Certain illustrative embodiments of the invention are described below. The present invention is not limited to these embodiments.
In one embodiment, the present invention provides artificial polymer matrices for use in cultures stem cells (e.g., embryonic stem cells (ESCs) or adult stem cells). In some embodiments, such matrices support ESC colony formation, proliferation and maintenance of a pluripotent state. In one embodiment, the artificial polymer matrices are comprised of synthetic hydrogels. In some embodiments, the present invention provides artificial polymer matrices fabricated without the addition of naturally derived biomolecules, such as extracellular matrix components, growth factors, laminin, matrigel, fibronection, vitronectin, collagen, gelatin, and so on. In some embodiments, the artificial polymer matrix comprises negatively charged groups, such as phosphate groups, sulfate groups, carboxyl groups, sulfonate groups, phosphonate groups, and the like. In some embodiments, the artificial polymer matrices may further comprise positively charged groups, such as ammonium groups, and the like. In some embodiments, the artificial polymer matrices comprise simultaneously positively and negatively charged groups. In some embodiments, the artificial polymer matrices comprise, at least in part, zwitterionic groups (e.g., sulfobetaine). For example, zwitterionic groups are combined with other charged groups, such as positively and/or negatively charged groups. The matrix may comprise one or more types of zwitterionic groups. The incorporation of zwitterionic groups into the artificial polymer matrices allows the materials to engage in strong inter- and intramolecular deipolar interactions which span from a non-associated to a fully associated regime, behavioral characteristic for zwitterionic molecules. In one embodiment of the present invention the artificial polymer matrices comprise one, or more than one, type of zwitterionic group. In some embodiments, the zwitterionic group is
where x is any aliphatic or substituted aliphatic chain, aryl or substituted aryl chain, or hydrogen; and n is an integer of 1 or greater. In other embodiments the artificial polymer matrix comprises sulfobetaine groups. In some embodiments, the present invention provides a synthetic cell matrix system comprising, for example, poly[2-(methacryloyloxy)ethyl dimethyl(3-sulfopropyl)ammonium] (PMEDSAH) hydrogels or copolymers or blends thereof, or functional equivalents thereof, that supports long-term proliferation and passaging of hESCs. For example, during development of embodiments of the present invention, hESCs were subjected to at least eighteen continuous passages over a period of approximately seven months without undergoing unregulated differentiation. For example, hESCs cultured on PMEDSAH hydrogels retained normal karyotypes and continuously and consistently displayed the markers of undifferentiated hESCs. This is the first time that hESCs exhibited undifferentiated growth and passaging for extended times on fully synthetic cell matrices void of any xenogenic or previously used components.
In one embodiment, the artificial polymers form, for example, a three-dimensional polymer matrix structure. In yet another embodiment, biomolecules are further immobilized into the artificial polymer matrix. In some embodiments, biomolecules include, but are not limited to, small molecules for cell based therapies and treatments, drug delivery, and the like. In some embodiments, such polymer matrix structures provide, for example, scaffolds for cell growth for tissue regeneration.
In one embodiment, the present invention provides for the use of a synthetic hydrogel matrix comprising glycoproteins in growing and maintaining stem cells (e.g., embryonic stem cells or adult stem cells) in a pluripotent state, with native karyotype, for multiple passages. In some embodiments, the present invention provides for methods of culturing stem cells comprising providing stem cells, applying the stem cells to a substrate that has been treated with a synthetic hydrogel as previously described, and growing the stem cells on the substrate such that their pluripotency and native karyotype is maintained. In some embodiments, culture methods further comprise the use of a fully defined media.
In some embodiments, the present invention provides for compositions and methods of culturing stem cells for use in drug screening. In some embodiments, the present invention provides compositions and methods for culturing stem cells for use in screening for modulators of stem cell differentiation. In some embodiments, the present invention provides compositions and methods for culturing stem cells for use in research applications. In some embodiments, the present invention provides compositions and methods for culturing stem cells for use in clinical applications, such as determining compositions, drugs, small molecules, useful for, for example modulating stem cells for subsequent use in transplantation or treatment of diseases (e.g., leukemia, liver disease, brain diseases, proliferative diseases, etc).
In some embodiments, the present invention provides for compositions and methods for culturing embryos using the substrates described herein and optionally culture media suitable for culture of embryos.
DESCRIPTION OF THE FIGURES
FIG. 1 shows exemplary compositions attached TCPS dishes, thereby creating substrates that are coated with different synthetic polymer matrices.
FIG. 2 demonstrates the detection of A) undifferentiated hESC markers as seen in hESCs grown on PMEDSAH coated substrates after multiple passaging. Markers detected include OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81. The sixth frame demonstrates the staining hESC cells for pluripotency and normal colony morphology under phase contrast, and B) RT-PCR expression analysis of pluripotency markers; lane 1-no template control, lane 2-OCT 3/4 and lane 3-SOX-2 from undifferentiated hESC colonies, lane 4-KRT-18 from ectoderm, lane 5-BMP-4 from mesoderm, lane 5-GATA-4 from endoderm found in embryoid bodies, and lane 7-actin control.
FIG. 3 shows a depiction of the seeding, proliferation and passaging of hESCs cells on MEFs or an exemplary synthetic substrate.
FIG. 4 shows synthesis and characterization of polymer coatings (A) Schematic description of surface-initiated graft-polymerization used to deposit different synthetic polymer coatings onto TCPS dishes. (B) Comparison of the synthetic polymer coatings based on contact angle, attachment of hESCs, and initial undifferentiated growth and proliferation. (C) FT-IR spectrum of PMEDSAH polymer coated and uncoated TCPS surfaces. (D) Characteristic signals from high resolution C1s XPS spectrum of PMEDSAH.
FIG. 5 shows Characterization of hESCs cultured on PMEDSAH. (A) Human ESCs on PMEDSAH expressed ESC markers such as OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81. (B) Standard GTL-banding analysis revealed that hESCs maintained a normal female karyotype throughout the study. (C) RT-PCR analysis of expression of markers of pluripotency (lane 2: OCT3/4; lane 3: NANOG; lane 4: hTERT) from undifferentiated hESC colonies and from ectoderm (lane 5: KRT-18; lane 6: NESTIN), mesoderm (lane 7: FLT-1; lane 8: BMP-4; lane 9: VE-CADHERIN) and endoderm (lane 10: AFP; lane 11: GATA-4) found in EBs. Negative control (Lane 1: no template) and positive control (lane 12: ACTIN). (D) When differentiation was induced in hESCs maintained on PMEDSAH, positive immunoreactivity was identified for β III tubulin, smooth muscle actin and α-fetoprotein, indicating the presence of ectoderm, mesoderm and endoderm respectively. Scale bar is 200 μm. (E) Percentage (average±SEM) of Oct3/4 and Sox-2 positive cells on hESC colonies culture on PMEDSAH- and Matrigel-coated plates at passage 20. (F) Human ESCs growing on PMEDSAH showed an adaptive growth curve and reached a passage-time plateau of 8±1 days (average±SEM).
FIG. 6 results from Example 8 showing that genes of pluripotency such as nanog, Oct3/4 and Sox-2 were not significantly different expressed among hESCs cultured on PMEDSAH- and Matrigel-coated dishes.
DEFINITIONS
As used herein, the term “multiple passages”, “multiple passaging”, and/or “multiple mechanical passages or passaging”, refers to the number of times a cell is grown in vitro on a tissue culture substrate, released from that substrate, and reapplied to another substrate. For example, the present invention described embodiments where human embryonic stem cells were passaged numerous, thereby demonstrating that cells can be applied to a substrate, released from a substrate, and reapplied to another substrate while still allowing for growth and maintenance of the cell culture.
As used herein, the term “substrate” refers to a surface for cell culture. A substrate can be, for example, a glass slide, a culture dish, culture plates, glass or composite beads, chip microchannels, and the like. The present invention is not limited by the type of substrate used.
The term “chemical moiety” refers to any chemical compound containing at least one carbon atom. Examples of chemical moieties include, but are not limited to, aromatic chemical moieties, chemical moieties comprising Sulfur, chemical moieties comprising Nitrogen, hydrophilic chemical moieties, and hydrophobic chemical moieties.
As used herein, the term “aliphatic” represents the groups including, but not limited to, alkyl, alkenyl, alkynyl, alicyclic.
As used herein, the term “aryl” represents a single aromatic ring such as a phenyl ring, or two or more aromatic rings (e.g., bisphenyl, naphthalene, anthracene), or an aromatic ring and one or more non-aromatic rings. The aryl group can be optionally substituted with a lower aliphatic group (e.g., alkyl, alkenyl, alkynyl, or alicyclic). Additionally, the aliphatic and aryl groups can be further substituted by one or more functional groups including, but not limited to, —NH 2 , —NHCOCH 3 , —OH, lower alkoxy (C 1 -C 4 ), halo (—F, —Cl, —Br, or —I).
As used herein, the term “substituted aliphatic,” refers to an alkane, alkene, alkyne, or alicyclic moiety where at least one of the aliphatic hydrogen atoms has been replaced by, for example, a halogen, an amino, a hydroxy, a nitro, a thio, a ketone, an aldehyde, an ester, an amide, a lower aliphatic, a substituted lower aliphatic, or a ring (aryl, substituted aryl, cycloaliphatic, or substituted cycloaliphatic, etc.). Examples of such include, but are not limited to, 1-chloroethyl and the like.
As used herein, the term “linker” refers to a chain containing up to and including eight contiguous atoms connecting two different structural moieties where such atoms are, for example, carbon, nitrogen, oxygen, or sulfur.
As used herein the term, “in vitro” refers to an artificial environment and to processes or reactions that occur within an artificial environment. In vitro environments include, but are not limited to, test tubes and cell cultures. The term “in vivo” refers to the natural environment (e.g., an animal or a cell) and to processes or reaction that occur within a natural environment.
As used herein, the term “host cell” refers to any eukaryotic or prokaryotic cell (e.g., mammalian cells, avian cells, amphibian cells, plant cells, fish cells, and insect cells), whether located in vitro or in vivo.
As used herein, the term “cell culture” refers to any in vitro culture of cells. Included within this term are continuous cell lines (e.g., with an immortal phenotype), primary cell cultures, finite cell lines (e.g., non-transformed cells), and any other cell population maintained in vitro, including oocytes and embryos.
The term “sample” as used herein is used in its broadest sense. A sample suspected of indicating a condition characterized by the dysregulation of apoptotic function may comprise a cell, tissue, or fluids, chromosomes isolated from a cell (e.g., a spread of metaphase chromosomes), genomic DNA (in solution or bound to a solid support such as for Southern blot analysis), RNA (in solution or bound to a solid support such as for Northern blot analysis), cDNA (in solution or bound to a solid support) and the like. A sample suspected of containing a protein may comprise a cell, a portion of a tissue, an extract containing one or more proteins and the like.
As used herein, the terms “purified” or “to purify” refer, to the removal of undesired components from a sample. As used herein, the term “substantially purified” refers to molecules that are at least 60% free, preferably 75% free, and most preferably 90%, or more, free from other components with which they usually associated.
The term “test compound” refers to any chemical entity, pharmaceutical, drug, and the like, that can be used to treat or prevent a disease, illness, sickness, or disorder of bodily function, or otherwise alter the physiological or cellular status of a sample (e.g., the level of dysregulation of apoptosis in a cell or tissue). Test compounds comprise both known and potential therapeutic compounds. A test compound can be determined to be therapeutic by using the screening methods of the present invention. A “known therapeutic compound” refers to a therapeutic compound that has been shown (e.g., through animal trials or prior experience with administration to humans) to be effective in such treatment or prevention. In some embodiments, “test compounds” are agents that modulate apoptosis in cells.
DETAILED DESCRIPTION OF THE INVENTION
Certain illustrative embodiments of the invention are described below. The present invention is not limited to these embodiments.
The chemistry and morphology of the microenvironment surrounding a human embryonic stem cell plays an important role in the cellular behavior, controlling the orchestration of various developmental events, such as cell proliferation, differentiation, migration, and apoptosis. Given the importance of the chemical signature of the microenvironment, the development of fully-defined synthetic matrices is an important step towards fully synthetic cell culture systems, but will largely depend on materials selection for the cell substrate. Several synthetic polymers, such as PLGA, PLA, and PNIPAM-based polymers, as well as polymers obtained using combinatorial methods, have been previously evaluated. While these studies contributed to a fundamental appreciation of the importance of the chemical identity of the microenvironment, they fall short in reporting long-term undifferentiated growth and passaging of hESCs.
In developing embodiments of the present invention, functionally diverse groups of synthetic hydrogels and their use in hESCs adhesion studies were identified, and their subtle interrelationships between synthetic polymer matrices and hESCs, for example, were examined. Four hydrogels comprising identical methacrylate backbone structures, but different side chain chemistries, were deposited onto the surface of tissue culture styrene (TCPS) dishes via surface-initiated graft-polymerization. The resulting synthetic polymers were hydrogels with high to moderate hydrophilicity. On the basis of their side chain chemistries, these materials are classified as hydrogen-bond acceptors (PHEMA), hydrogen-bond donors (PPEGMA), charge-donors (PSMPA), or polyzwitterions (e.g., PMEDSAH) ( FIG. 1 ).
Artificial polymer matrices can be deposited onto the surface of a substrate, for example, using standard methods known to one skilled in the art. These methods may include surface physisorption or chemisorption. Physisorption includes, for example, the static and dynamic coating with polymers and/or oligomers. Chemisorption includes methods such as surface-initiated polymerization, grafting including grafting-from and grafting-to techniques, covalent tethering to the surface, crosslinking using exposure of the substrate to a solution of a polymer and/or oligomers followed by treatment with an energy source, such as plasma, UV, gamma radiation, ion beam, and the like.
Undifferentiated hESCs from cell lines H9 and BG01 growing on MEF as previously described (Thomson et al, 1998), were mechanically harvested and seeded onto the different hydrogel-coated plates. The surfaces were compared to solvent-casted poly(α-hydroxy esters), PLA, PLGA, and MATRIGEL coated substrates. Cell culture experiments were conducted in MEF-conditioned medium (MEF-CM) (Amit et al., 2003). Following initial hESC seeding, no cell attachment was observed on PLA, PLGA, the negatively charged PSPMA substrate, or PHEMA (Table 1).
TABLE 1
Contact
Long
Polymer
angle
Attachment
term
polyMEDSA
45
+
+
polyHEMA
55
−
−
polyPEGMA
60
+
−
polySPMA
80
−
−
PLA
9/33
−
−
PLGA
−
−
In contrast, hESC attachment was observed on poly (ethylene glycol) methyl ether methacrylate (PEGMA), and unmodified TCPS plates; however colonies did not grow with time and/or hESCs spontaneously differentiated during the first or second passage. These data are consistent with the recently reported short-term self-renewal of hESCs on polymer matrices (Li et al., 2006, J. Biomad. Mater. Res. A 79:1-5). None of the hydrogels showed consistent long-term growth, consecutive passaging, and maintenance of long-term pluripotency. MATRIGEL-coated dishes and PMEDSAH hydrogel coatings supported initial cell adhesion and proliferation.
The physical and chemical properties of PMEDSAH coatings were characterized using a combination of surface analytical tools including X-ray photoelectron microscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), imaging ellipsometry, and scanning probe microscopy (SPM). PMEDSAH films used had an average surface root mean square roughness of 0.91 nm as determined by SPM. Imaging ellipsometry showed PMEDSAH film thicknesses between 10 and 2000 nm. The polymer films were stable when stored for extended times in aqueous solutions. As such, it was concluded that the PMEDSAH coatings were characterized by ultra-thin, smooth polymer films chemically tethered to the TCPS substrate. FT-IR spectra showed distinct bands at 1724 cm −1 indicating the presence of carbonyl groups characteristic of PMEDSAH. To further confirm initial evidence from the FT-IR studies that indicated the presence of twitterionic groups on the surface, the elemental surface composition of PMEDSAH coatings was quantified by X-ray photoelectron spectroscopy (XPS). The presence of characteristic peaks associated with nitrogen, sulfur, and oxygen, and the relative composition of these elements correlated well with the expected chemical composition of PMEDSAH. In addition, the high resolution C 1s spectrum of PEDMSAH revealed characteristic signals associated with hydrocarbon ( C —H/C) peak at 285.0 eV, ammonium-bond carbon (— C —N + ( C H 3 ) 2 —) at 286.4 eV, and ester carbon (— C OO—) peak at 288.9 eV. Taken together, FTIR and XPS analysis confirms the overall chemical composition of PMEDSAH coating, and demonstrates the presence of twitterionic groups at the surface of the coating. Moreover, contact angle measurements revealed an advancing contact angle of above 45 degrees of the PMEDSAH coating, which is in accordance with a self-associated super-coiled regime. It was determined, therefore, that the PMEDSAH coatings used in developing embodiments of the present invention, have, for example, properties that distinguish them from the other hydrogel coatings.
Initial experiments revealed, for example, a positive influence of PMEDSAH hydrogels on human embryonic cell culture adhesion and proliferation when compared to other synthetic polymers. In additional experimentation, growth and passaging of hESC on PMEDSAH and MATRIGEL dishes over a period of 6 months was performed. Human ESCs were passaged multiple times (e.g., for example, up to 18 passages; i.e., greater than 2, 5, 10, 15 passages) and cell fate of hESCs was continuously monitored by immunostaining. It was observed that PMEDSAH hydrogels supported cell attachment, colony growth, and hESC proliferation for more than eight months (e.g., more than 1, 2, 4, 6, months) over multiple passages. Human ESCs were characterized at regular intervals throughout the course of experimentation. After 7 months (roughly 18 passages), hESCs cultured on PMEDSAH expressed pluripotency markers, such as OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81 ( FIG. 2A ), and retained normal karyotypes. The latter is an important aspect, for example, because the long-term culture of mouse (Longo et al., 1997, Transgenic Res. 6:321-328) and human (Draper et al., 2004, Nat. Biotech. 22:53-54; Maitra et al., 2005, Nat. Genet. 37:1099-1103) ESCs can lead to distinct chromosomal abnormalities and hESC feeder-free culture may bias for occurrence in aneuploidy (Matira et al., 2005; Brimble et al., 2004, Stem Cells 13:585-597). In concordance, chromosome instability and decreased pluripotency of hESCs was reported on cells adapted to grow on TCPS plates and passaged by enzymatic method (Imreh et al., 2006, J. Cell Biochem. 99:508-516).
Pluripotency of hESCs was tested in vitro by embryoid body (EB) formation and identification of genes representative of the three germ line cells: ectoderm (KRT-18), mesoderm (BMP-4) and endoderm (GATA-4) and several other cell-tissue specific genes ( FIG. 2B ). Occasionally, spontaneous differentiation of hESCs growing on PMEDSAH as well as MATRIGEL was observed at very low rates (<5%). The observed differentiated colonies can be divided into two groups; A) one subpopulation had indistinct borders, with larger cells that migrated away from the colony, and B) another subpopulation of fibroblast-like cells growing between undifferentiated hESC colonies. These fibroblast-like cells were negative for hESC markers. Similar fibroblast-like cells surrounding undifferentiated hESC colonies have been reported previously for feeder-free hESC cultures (Xu et al., 2001, Nat. Biotech. 971-974; Klimanskaya et al., 2005, Lancet 365:1636-1641; Ullmann et al., 2007, Mol. Human. Repro. 13:21-32).
As such, one embodiment the present invention provides synthetic glycoprotein coated substrates, for example PMEDSAH coated substrates, for culturing hESCs wherein the cultured hESCs maintain pluripotency and normal karyotypes. In some embodiments, the PMEDSAH coated surfaces support hESC culture and mechanical propagation for at least 3 passages, at least 5 passages, at least 7 passages, at least 10 passages, at least 15 passages, at least 18 passages over a period of, for example, at least 3 months, at least 5 months, at least 7 months while retaining normal hESC karyotype and pluripotency.
While performing experimentation in development of embodiments of the present invention, phenotypes and genotypes of hESCs cultured on PMEDSAH were basically undistinguishable from those cultured on MATRIGEL. However, interesting differences with respect to the proliferation kinetics were observed between hESCs grown on PMEDSAH and MATRIGEL. For example, while monitored the time between passages (e.g., the time that it takes for a cell population to obtain cell densities sufficient for passaging), colonies grown on PMEDSAH required approximately 17 days to reach their first passage point. Thereafter, passaging points gradually decreased until they reached a plateau of approximately 7 days where it stabilized. In contrast, hESC colonies cultured on MATRIGEL had passaging points after an average of 10 days, and passage points were independent of the passage cycle. A detailed morphological analysis of hESCs cultured on PMEDSAH or MATRIGEL revealed several noteworthy aspects. For example, in contrast to MATRIGEL, where hESCs initially formed small colonies that increased in size and cell number over the next few days (Amit et al., 2003), several embryoid body-like structures and few small colonies were initially observed on the synthetic PMEDSAH hydrogel. Within a few days, growth on PMEDSAH hydrogels demonstrated EB-like structures attached to the hydrogel and hESC proliferation started forming colonies with defined borders and cells with high nucleus to cytoplasm ratio. Additionally, the shape of the initial colonies resembled cell colonies typically encountered for hESCs grown on MEF, and hESCs cultured on the synthetic hydrogel, but not on MATRIGEL, underwent an adaptive growth curve. While all pluripotency markers as well as karyotyping indicates that the undifferentiated cell state of hESCs cultured on PMEDSAH remained unchanged, the gradual decrease of passaging points with increasing passage cycles indicates the ability of hESCs to adapt to this specific synthetic cell matrix.
As described herein, hESCs cultured on PMEDSAH have been propagated for at least eighteen passages during 7 months. All PMEDSAH plates (more than 300 from 20 different batches) successfully support hESC attachment, growth and proliferation, thereby demonstrating that the synthetic substrates as described herein can be synthesized reproducibly with reliability. As well, PMEDSAH-coated plates were stored for several weeks to months and were UV sterilized prior to use, and neither storage nor sterilization negatively affected their ability to support hESC growth and proliferation. In addition, hESCs cultured on PMEDSAH have been cryopreserved using a controlled-rate freezer, thawed, and seeded again effectively on synthetic PMEDSAH matrices.
I. Polymers
As described above, in some embodiments, the present invention provides synthetic polymer substrates for the growth and maintenance of stem cells or embryos. The present invention is not limited to a particular polymer. In certain embodiments, the polymer has a zwitterionic group. In some exemplary embodiments, the zwitterionic group is
where x is any aliphatic or substituted aliphatic chain, any aryl or substituted aryl chain or hydrogen; and n is an integer of 1 or greater. In some embodiments, the zwitterionic group is MEDSAH. In other embodiments, the zwitterionic group is a zwitterionic group described, for example, in U.S. Pat. No. 6,395,800, herein incorporated by reference.
II. Uses of Synthetic Polymer Substrates
In one embodiment, the present invention provides for synthetic polymer substrates for use in tissue engineering. For example, compositions as described herein find use as a scaffold for growth of cells and tissues for implantation or transplantation into a subject, such as a human. As such, some embodiments of the present invention comprise methods for growing cells and tissues on scaffolds comprising synthetic polymer substrates as defined herein, wherein such scaffolds are used to grow cells in vitro or in vivo. For example, cells and tissues grown on in vitro scaffolds are used to grow cells and tissues for use in, for example research purposes and for implantation or transplantation into subjects as a treatment of a condition or disease. Scaffolds comprising the synthetic polymer matrices as described herein can also be implanted on, or into, a subject thereby aiding in seeding of cells for growth or regeneration of cells and tissues in a particular area or location of a subject to treat a disease or condition.
As such, the present invention provides compositions and methods for defined synthetic substrates for stem cell (e.g., adult or embryonic stem cell) culture, such as PMEDSAH, which represents a system for elimination of xenogeneic components in stem cell derivation and culture. In some embodiments, the present invention provides methods of using the synthetic matrices as described herein to grow and maintain cells (e.g., stem cells such as adult or embryonic stem cells) or embryos useful for fundamental research, cell based therapies, clinical disease applications, therapeutic discoveries, drug screening, toxicology testing, and regenerative medicine. In some embodiments, culture methods utilize fully defined media (e.g., available from Stem Cell Sciences, San Francisco, Calif.), other commercially available media, or other suitable culture media) in combination with the compositions of embodiments of the present invention.
EXPERIMENTAL
The following examples are provided in order to demonstrate and further illustrate certain preferred embodiments and aspects of the present invention and are not to be construed as limiting the scope thereof.
Example 1
Human ESC Culture
The culture medium for hESCs growing on irradiated mouse embryonic fibroblast (MEF) cells consisted of DMEM/F12 supplemented with 20% knockout serum replacement, 0.1 mM β-mercaptoethanol, 1 mM L-glutamine, 1% nonessential amino acids and 4 ng/ml human recombinant basic fibroblast growth factor. To obtain MEF-conditioned media (MEF-CM), irradiated MEFs (8×10 6 ) were seeded on pre-gelled culture plate dishes. Twenty-four hours after plating, media was replaced for hESC culture media (60 ml), left in contact with MEFs to be conditioned for 24 h, and collected. Mouse embryonic fibroblasts were again fed with hESC culture media daily and used for 4 day CM collection. The CM was frozen at −20° C. until use, and before use it was supplemented with additional 0.1 mM13-mercaptoethanol, 2 mM L-glutamine, and 4 ng/ml bFGF. Passage of undifferentiated colonies was done manually cutting small clumps of cells. Criteria for passage was when greater than 50% of colonies reached a mean diameter of 1 cm or greater and had an architecture of 2-3 cell layers thick ( FIG. 3 ).
Substrates were prepared on tissue culture polystyrene plates (TCPS; 35 mm; Becton Dickinson and Co, Franklin Lakes, N.J.). Bare TCPS and MATRIGEL-coated plates were used as controls. MATRIGEL-coated plates were prepared with MATRIGEL (BD BioSciences, San Jose, Calif.) diluted 1:20 in cold DMEM/F12 at placed at 4° C. overnight, or at room temperature for 2 h. Coating of HEMA, MEDSAH, PEGMA and SMPS onto PTCP was done by activation of the polystyrene surface and initiation of graft-co-polymerization of methacrylate monomers using UV-ozone. Both PLGA and PLA coatings were created by casting polymer films in a Teflon dish and attaching these films to PTCP afterwards.
For MEDSAH, the surface of the substrate was activated using the UV-Ozone generator for 40 min. Graft polymerization onto the polyslyrene surface was carried out at 80° C. with a solution of 0.25M MEDSAH in a 4:1 Mixture of water and ethanol. The polymerization reaction was performed for 2 hours. The substrates were then washed in DI-water at 40-50° C. for 1 hour and dried under nitrogen.
Example 2
Synthetic Substrate Characterization
Coating presences were confirmed using Fourier transformation infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and imaging ellipsometry. Surface morphology of coatings was elucidated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Synthetic substrates plates were maintained at room temperature in desiccators and were exposed to UV-light for 15 min before using. Prior to cell seeding, all surfaces were washed twice with PBS, MEF-CM was added, and the plates were incubated at 37° C. in 5% CO 2 overnight.
Example 3
Immunostaining
Immunostaining on cultured cells was performed to evaluate whether the synthetic substrates could maintain the hESCs in an undifferentiated state. For detecting OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81, cells were fixed with 2% paraformaldehyde at room temperature for 15 min followed by permeabilization with 0.1% Triton X-100 for 10 min. All antibodies were detected with flourescein isothiocyanate (FITC)-labeled secondary antibody except for OCT3/4, which was detected with Texas Red-labeled secondary antibody. Cells were typically evaluation at the 5 th , 10 th and 15 th passages. It was determined that the large majority of hESCs remained undifferentiated, with a low incidence (<5%) of spontaneous differentiation observed.
Example 4
In Vitro Evaluation of Pluripotency
Embryoid bodies derived from clumps were cultured in suspension with culture medium without bFGF for four days and evaluated for pluripotency ( FIG. 2 , sixth frame).
Example 5
Reverse-transcription PCR Analysis
RT-PCR was performed from total RNA extracted from cells and EBs with TRIzol reagent (Invitrogen) following manufacturers protocol, and SuperScript™ One-Step RT-PCR with Platinum® Taq (Invitrogen) was used for RT-PCR. One microgram of total RNA plus 20 μmol of forward and reverse primers were used in a 50 μl reaction. The cDNA synthesis and pre-denaturation were carried out in one cycle of 48° C. for 45 min, followed by one cycle at 94° C. for 2 min. PCR amplification was performed for 35 cycles at 94° C. for 15 sec, 54° C. for 30 sec, and 72° C. for 1 min. The final extension cycle was 72° C. for 8 min. Ten microliters of each PCR reaction were loaded onto a 1.0% agarose gel and size fractionated. Primers used were; undifferentiation cell markers: OCT 3/4: (f) 5′-ctg cag tgt ggg ttt cgg gca-3′ (SEQ ID NO: 1), (r) 5′-ctt gct gca gaa gtg ggt gga gga-3′ (SEQ ID NO: 2); and SOX-2: (f) 5′-atg cac cgc tac gac g-3′ (SEQ ID NO: 3), (r) 5′-ctt ttg cac ccc tcc cat tt-3′ (SEQ ID NO: 4); for endodermal differentiation: GATA4: (f) 5′-ctc ctt cag gca gtg aga gc-3′ (SEQ ID NO: 5), (r) 5′-gag atg cag tgt gct cgt gc-3′ (SEQ ID NO: 6); for mesodermal differentiation: BMP4: (f) 5′-tga gcc ttt cca gca agt tt-3′ (SEQ ID NO: 7), (r) 5′-ctt ccc cgt ctc agg tat ca-3′ (SEQ ID NO: 8); for ectodermal differentiation: KRT18: (f) 5′-tct gtg gag aac gac atc ca-3′ (SEQ ID NO: 9), (r) 5′-ctg tac gtc tca gct ctg tga-3′ (SEQ ID NO: 10); and as a control, β-ACTIN: (f) 5′-atc tgg cac cac acc ttc tac aat gag ctg cg-3′ (SEQ ID NO: 11), (r) 5′-cgt cat act cct gct tgc tga tcc aca tct gc-3′ (SEQ ID NO: 12).
Example 6
Cytogenetic Analysis
Karyotype of hESCs growing on sulfonated hydrogels at passage 5 and 10 was performed. Chromosome preparation was done using standard protocols and the analysis by GTG banding method. At least 20 cells from each sample were examined by a qualified cytogeneticist.
Example 7
Cryopreservation and Thawing
Cryopreservation by controlled-rate freezing was performed followed a previously established protocol (Ware et al., 2005, Biotechniques 38:879-884), with some modifications. Briefly, clumps were suspended in 250 μl of freezing medium and placed in a 1.2 ml cryovial (Fisher Scientific, Pittsburgh, Pa.). The freezing medium consisted of DMEM (with 4.5 g/L of glucose; Invitrogen), 25% knockout SR (vol/vol), and 10% DMSO (Sigma, St. Louis, Mo.; vol/vol). Cryovials were placed inside a programmable freezing machine (CL-8000, Cryologic, Mulgrave, Victoria, Australia) and lowered from 20° C. to −10° C. at 2° C./min. At −10° C. cryovials were seeded and 5 minutes later the cooling cycle started decreasing 1° C./min to −33° C. Cryovials were then plunged into liquid nitrogen (LN 2 ), held for at least 5 min at −196° C. and maintained in the vapor phase of LN 2 (VLN 2 ). Clumps were thawed rapidly by removing the cryovials from VLN 2 storage and plunging them directly into 37° C. bath for 1 min. Thawed clumps were washed with culture medium and plated on sulfonated hydrogel plates.
Example 8
Synthetic Polymer Coatings for Long-term Maintenance of Undifferentiated Human Embryonic Stem Cell Growth
A. Methods
Cell culture. Culture medium for hESCs growing on irradiated MEFs consisted of standard Dulbecco's modified Eagle's medium/F12 (DMEM/F12; GIBCO, Carlsbad, Calif.) supplemented with 20% KnockOut serum replacement (GIBCO), 0.1 mM β-mercaptoethanol, 1 mM L-glutamine, 1% non-essential amino acids and 4 ng/ml human recombinant basic fibroblast growth factor (bFGF) (Xu et al., Nat. Biotechnol. 19:971 [2001]). To obtain MEF-CM, irradiated MEFs (8×10 6 cells) were seeded onto gelatin coated culture dishes in medium composed of high glucose DMEM, 10% fetal bovine serum (FBS), 1% non-essential amino acids, and 200 mM L-glutamine. After 24 h, MEF culture medium was replaced with the hESC culture medium described above (60 ml). This medium was left in contact with MEFs and was collected as MEF-CM after 24 h of conditioning. Media exchange was conducted daily and MEF-CM was collected for 3 days. The MEF-CM was frozen at −20° C. until use, when it was supplemented with 0.1 mM β-mercaptoethanol, 2 mM L-glutamine, and 4 ng/ml bFGF just prior to use (Xu et al., supra). Undifferentiated colonies were mechanically passaged by cutting small clumps of cells when more than 50% of the colonies attained a mean diameter greater than 1 cm and a thickness of 2-3 cell layers.
Cell-culture substrate synthesis. All polymer coatings were prepared on TCPS dishes (35 mm; Becton Dickinson and Co, Franklin Lakes, N.J.). Matrigel-coated and bare TCPS dishes were used as controls. Matrigel (BD BioSciences, San Jose, Calif.) was diluted 1:20 in cold DMEM/F12, applied to the dishes, and coating was allowed to form at 4° C. for overnight or at room temperature for 2 h. Graft-co-polymerization of methacrylate polymers onto TCPS surfaces was carried out using a 0.25 M solution of methacrylate monomers (Sigma-Aldrich, MO) in a 4:1 mixture of water and ethanol (Wu et al., Biomed Microdevices 8:99 [2006]). The TCPS dishes were activated using a UV-ozone generator (Jelight Co. Inc) for 40 min. Surface-activated dishes were immersed into the monomer solution which was heated to 80° C. for 2.5 h. The TCPS dishes were allowed to cool to 50° C. and were rinsed with a warm saline solution (0.9% NaCl, at 50° C.). Polymer coated dishes were left overnight in saline solution at 50° C. The dishes were cleaned by ultra-sonication in DI-water and dried under a stream of nitrogen gas. Both PLA (Sigma-Aldrich, MO) and PLGA (75:25; Sigma-Aldrich, MO) films were cast in a Teflon dish (diameter of 15 cm) by dissolving the polymer (1 g) in chloroform (50 ml) and allowing the solvent to evaporate. The film was carefully peeled off the Teflon dish after 2 days and cut into the requisite size. After extensive washing in DI-water and drying under vacuum, the casted film was attached to the TCPS dish.
Characterization of polymer coatings and preparation for cell culture. Presence of polymer coatings was confirmed using FTIR spectroscopy (Nicolet 6700 spectrometer) in the attenuated total reflectance (ATR) mode with a ZnSe 45° crystal. Elemental analysis was conducted using XPS (Axis Ultra XPS, Kratos Analyticals, UK) equipped with a monochromatized Al Kα X-ray source. The spectra were referenced to an unfunctionalized aliphatic carbon at 285.0 eV. Thickness of the coatings was recorded at a wavelength of 532 nm using EP 3 —SW imaging ellipsometry (Nanofilm Technology GmbH, Germany). Four-zone nulling was performed at an angle of incidence of 58° and an anisotropic Cauchy parameterization model was used for curve fitting. Surface morphology of coatings was elucidated using SPM. Polymer-coated dishes were stored in desiccators at room temperature. Before cell seeding, dishes were sterilized by exposure to UV-light for 15 min and were washed twice with PBS. Finally dishes were incubated with MEF-CM overnight at 37° C. in a 5% CO 2 atmosphere.
Immunostaining. The cells were fixed in 2% paraformaldehyde for 30 min at room temperature and then permeabilized with 0.1% Triton X-100 for 10 min. Primary antibodies were diluted in 1% normal donkey serum and incubated overnight at 4° C. Fluorescein isothiocyanate (FITC)-labeled secondary antibodies were used to detect SOX-2 (Chemicon, Billerica, Mass.), TRA-1-60 (Chemicon), TRA-1-81 (Chemicon) and smooth muscle actin antibodies (DakoCytomation, Denmark). For the detection of OCT3/4 (Santa Cruz Biotechnology Inc., Santa Cruz, Calif.), SSEA-4 (Developmental Studies Hybridoma Bank, Iowa University), β III tubulin (Sigma) and α-fetoprotein (Sigma) antibodies, Texas red-labeled secondary antibodies were used. Samples were imaged using phase-contrast and fluorescent microscopy.
Image analysis. Cell nuclei count was performed with Image J 1.37v on photomicrographs of hESC colonies stained with Hoechst 33258 nuclear staining and either Oct3/4 or Sox-2 antibodies. Then, the percentage of cells positive to either antibody was calculated and compared among colonies culture on PMEDSAH- and Matrigel-coated plates. Unpaired t test was used to calculate the p value.
In vitro evaluation of pluripotency. Pluripotency was evaluated by embryoid body formation at 5, 10, 15 and 20 passages. Embryoid bodies derived from clumps of undifferentiated hESC colonies were cultured in suspension in a medium lacking bFGF to promote differentiation for 10 days. Alternatively, hESCs were allowed to overgrow in differentiation medium for 10 days.
Extraction and purification of total RNA from hESCs and EBs. After manually scrap, cells were pelleted by centrifugation at 800×g in RNase-free, 1.5 ml siliconized microcentrifuge tubes (Ambion, Austin, Tex.). Pellets were disrupted by vigorous pipeting in 800 μl of Trizol Reagent (Invitrogen, Carlsbad, Calif.). This solution was transferred to 2 ml PhaseLoc-Heavy tubes (Eppendorf, Hamburg, Germany), 200 μl of chloroform were added/800 μl of Trizol, and the tubes were centrifuged at maximum speed (13,000×g) in a microcentrifuge. The aqueous phase containing RNA was removed and additionally purified using the RNeasy Mini-Kit (Qiagen, Valencia, Calif.) following the manufacturer's RNA Clean-up protocol with the optional On-column DNase treatment; following the Qiagen protocols. RNA quality was checked using RNA 6000 Nano Assays performed on the Bioanalyzer 2100 Lab-on-a-Chip system (Agilent Technologies, Palo Alto, Calif.).
Reverse-transcription PCR analysis. Total RNA was reverse transcript using SuperScript™ One-Step RT-PCR with Platinum® Taq (Invitrogen) was used. In a single reaction (50 μl), 1 μg of total RNA and 20 pmol of forward (f) and reverse (r) primers were used (Table 4). The cDNA synthesis and pre-denaturation were carried out in the first cycle at 48° C. for 45 min, followed by a second cycle at 94° C. for 2 min. The PCR amplification was performed for 35 cycles at 94° C. for 15 sec, 5° C. for 30 sec, and 72° C. for 1 min. The final extension cycle was operated at 72° C. for 8 min. Finally, 10 μl of PCR reaction products were loaded onto a 1.0% agarose gel and size-fractionated.
Microarray analysis. Total RNA (10 μg) from cells was hybridized to Affymetrix Human Genome U133 Plus 2.0 microarray (Affymetrix; Santa Clara, Calif.) following the manufacturer's instructions. Data analysis was performed using a Robust Multi-array average that converted the plot of perfect match probe into an expression value for each gene (Irizarry et al., Biostatistics 4:249 [2003]). Based on a variance of 0.05, all the probe sets that did not appear to be differentially expressed in any samples were filtered and removed. The fit a linear model were using to increase the power of microarray analysis (Smyth et al., Bioinformatics 21:2067 [2005]).
Microarray validation by real time-PCR analysis. Total RNA was reverse-transcribed using MultiScribe™ Reverse Transcriptase System (Applied Biosystems; Foster city, CA). The ABI 7300 PCR and Detection System (Applied Biosystems) with SYBR® Green PCR Master Mix (Applied Biosystems) was used in real time-PCR. PCR was conducted in triplicate for each sample. Primers were indicated in Table 4. Human Actin was amplified as an internal standard. Reported values were calculated using ΔΔCt method, normalized against endogenous Actin.
Cytogenetic analysis. Karyotype analysis of hESCs was performed at 5, 10, 15 and 20 passages by cytogeneticists at Cell Line Genetics. Chromosomes were prepared using standard protocols and measurement was done using the GTL-banding method on at least 20 cells.
B. Results
A chemically diverse group of synthetic polymer coatings was selected for cell adhesion studies. To ensure structural consistency between different materials, polymer materials were selected that shared an identical polymer backbone structure, but differed in their side chain chemistries. In addition, the same 5 fabrication method, surface-initiated graft-polymerization, was used to deposit all synthetic polymer coatings onto tissue culture polystyrene (TCPS) dishes ( FIG. 4A ). As shown in FIG. 4B , differences in side chains result in synthetic polymer coatings with high to moderate hydrophilicity (based on contact angle measurements). Based on side chain chemistries, polymer coatings can be classified as hydrogen-bond acceptors (poly[2-hydroxyethyl methacrylate], PHEMA), hydrogen-bond donors (poly[poly(ethylene glycol) methyl ether methacrylate], PPEGMA), charge-donors (poly[3-sulfopropyl methacrylate], PSPMA), or polyzwitterions (PMEDSAH). This group of polymer coatings was compared to two solvent-cast poly(α-hydroxy esters), PLA and PLGA, as well as Matrigel-coated and unmodified TCPS dishes. Two federal approved hESC lines (H9, NIH code: WA09; WiCell, Madison, Wis.; and BG01, NIH code: BG01; BresaGen, Inc., Athens, Ga.) were used throughout the study. Colonies of hESCs previously cultured on mouse embryonic fibroblasts (MEF) were mechanically harvested and transferred onto polymer-coated cell culture dishes using the approach illustrated in FIG. 3 . All cell culture experiments were conducted with MEF-conditioned medium (MEF-CM), which supports hESC growth and proliferation (Xu et al., supra). This approach enables delineation of influences of the matrix versus medium.
During initial cell passages on PLA and PLGA coatings, no hESC attachment was observed. PHEMA, PPEGMA and the negatively-charged PSPMA coatings as well as unmodified TCPS dishes supported initial hESC attachment and proliferation, but the majority of colonies spontaneously differentiated during the first (PPEGMA-coated dishes) or second passage (PHEMA, PSPMA and unmodified TCPS dishes), and propagation of undifferentiated cells was not possible ( FIG. 4B ). These findings are consistent with a recent study that reported short-term hESC attachment and proliferation on peptide-modified PNIPAAm matrices (Li et al., Journal of Biomedical Materials Research, Part A 79A, 1-5 [2006]). However, a completely different result was observed on PMEDSAH coatings: hESCs not only adhered and proliferated on these surfaces, but also expressed characteristic pluripotent stem cell markers and transcription factors such as OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81, which are associated with the undifferentiated state of hESCs. Based on these short-term adhesion studies, the surfaces were categorized into three groups: (1) Polymer coatings that did not support hESC adhesion (PLA, PLGA, and PSPMA); (2) polymer coatings that supported initial adhesion, but resulted in subsequent differentiation (PEGMA, PHEMA, and TCPS); and (3) polymers that supported adhesion and undifferentiated growth of hESCs (PMEDSAH, Matrigel).
To further characterize the supportive role of PMEDSAH coatings for long-term hESC growth and passaging, a more detailed assessment of the physico-chemical and structural properties of PMEDSAH hydrogel coating was undertaken. One of the most prominent characteristics of PMEDSAH is the presence of zwitterionic sulfobetaine groups. As shown in FIG. 3A , negatively-charged sulfonate and positively-charged quaternary ammonium groups coexist in PMEDSAH in the form of sulfobetaines. This molecular structure results in unusually high localized dipole moments of 23 D23 oriented parallel to the surface while maintaining a net neutral surface. As a result, PMEDSAH can engage in strong inter- and intramolecular dipole interactions, and exist as non-associated as well as fully associated structures (Azzaroni et al., Angewandte Chemie, International Edition 45, 1770-1774 [2006]). Such complex structural behavior is not present in the other synthetic polymer coatings included in this study, but is frequently encountered in naturally-derived materials, such as proteins, which are often considered as prime examples of zwitterionic molecules (Harris et al., Biochemical J. 24:1080 [1930]). Surfaces that present zwitterionic sulfobetaine groups have been used as biomedical coatings or protein-resistant surfaces (Yuan et al., Colloids Surf B Biointerfaces 35, 1-5 [2004]; Jiang et al., Colloids Surf B Biointerfaces 36, 19-26 [2004]; Cho et al., Langmuir 23, 5678-5682 [2007]).
To fabricate synthetic cell culture matrices, PMEDSAH coatings were polymerized on the surfaces of TCPS dishes using a grafting-from approach. Compared to alternate surface modification techniques, such as tethering of polymer chains onto the surface, this approach is known to result in higher surface densities (Zhao et al. Progress in Polymer Sci 25:677 [2000]). After grafting, PMEDSAH coatings were characterized using a combination of surface analytical tools which included X-ray photoelectron microscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), imaging ellipsometry, and scanning probe microscopy (SPM). The polymer coatings had an average thickness of 200 nm, as determined by imaging ellipsometry and an average root mean square (RMS) surface roughness of 0.91 nm, which was determined by SPM. Contact angle measurements revealed an advancing contact angle of 45°, which is in accordance with a self-associated super-coiled regime (Arasawa et al., Reactive and Function Polymers 61: 153 [2004]). On the basis of these data, the resulting polymer coatings are best described as ultra-thin, smooth polymer films consisting of coiled sub-domains chemically tethered to the TCPS surface. Further information regarding the chemical identity of these coatings was revealed by the FT-IR spectrum of the polymer coating ( FIG. 4C ). Distinct bands were identified at 1724 cm −1 and 1196 cm −1 indicated the presence of carbonyl groups and sulfonate groups respectively and clearly identified the PMEDSAH polymer coatings. To further confirm initial evidence from FT-IR studies, the elemental composition of PMEDSAH was quantified by means of XPS. Presence of characteristic signals associated with nitrogen were found at 402.0 eV, sulfur at 168.0 eV, and oxygen at 532.0 eV. The relative composition of these elements showed good agreement with the expected chemical composition of PMEDSAH. In addition, the high resolution C1s XPS spectrum of PMEDSAH revealed characteristic signals associated with hydrocarbon (C—H/C) at 285.0 eV, ammonium-bond carbon (—C—N+(CH3)2-) at 286.4 eV, and ester carbon (—COO—) at 288.9 eV ( FIG. 4D ). Taken together, FT-IR and XPS analyses not only established the chemical composition of PMEDSAH coating, but also provided strong evidence for the presence of zwitterionic groups at the coating surface (Lahann et al., Macromolecules 35:4380 [2002]). Owing to their supportive influence on hESC adhesion and proliferation in short-term experiments together with their unusual chemical properties, PMEDSAH coatings clearly distinguished themselves from other synthetic polymers studied here and elsewhere (Anderson et al., Nature Biotechnology 22:863 [2004]; Ilic, Regenerative Medicine 1:95 [2006]).
To evaluate long-term impact of PMEDSAH hydrogel surfaces on stem cell culture, hESCs were mechanically passaged to PMEDSAH- and Matrigel-coated dishes. The cells were monitored at regular intervals using karyotyping, expression of ESC markers and in vitro evaluation of pluripotency. It was found that dishes coated with PMEDSAH supported cell attachment, colony growth, and hESC proliferation for over 8 months. After 5, 10, 15 and 20 passages on PMEDSAH, hESCs were examined by immunostaining, and they expressed pluripotency markers including OCT3/4, SOX-2, SSEA-4, TRA-1-60 and TRA-1-81 ( FIG. 5A ). Standard GTG-banding analysis, after every fifth passage, revealed that hESCs maintained a normal karyotype ( FIG. 5B ). Presence of a normal euploid karyotype demonstrates pluripotency. Long-term cultures of mouse31 and human32-35 ESCs have shown to bias for the occurrence of aneuploidy. PMEDSAH coatings have supported hESC culture for 20 passages over a period of 8 months retaining normal karyotype and pluripotency.
The pluripotency of hESCs was further validated in vitro by formation of embryoid bodies and detection of characteristic genes representative of the three embryonic germ layers: ectoderm (KRT-18 and NESTIN), mesoderm (FLT-1, BMP-4 and VE-CADHERIN) and endoderm (AFP and GATA-4) ( FIG. 5C ). Furthermore, hESCs were allowed to overgrow in a non-supportive medium followed by immunostaining with antibodies specific for β III tubulin (ectoderm), smooth-muscle actin (mesoderm) and α-fetoprotein (endoderm) to identify differentiated cells from the three germ layers ( FIG. 5D ).
Throughout this study, phenotypic and genotypic characteristics of hESCs cultured on PMEDSAH coatings were indistinguishable from those on Matrigel-coated dishes. For example, at passage 20 the percentage of cells expressing Oct3/4 and Sox-2 for colonies grown on PMEDSAH-coated dishes was 91.40%±3.43 and 92.06%±2.22 respectively as against 93.00%±3.62 and 89.21%±3.52 for Matrigel-coated dishes ( FIG. 5E ). Validation by real time PCR analysis verified that genes of pluripotency such as nanog, Oct3/4 and Sox-2 were not significantly different expressed among hESCs cultured on PMEDSAH- and Matrigel-coated dishes ( FIG. 6 ). In addition, microarray analysis was conducted to elucidate mechanistic differences between hESCs grown on PMEDSAH versus Matrigel. Only 23 genes (out of a total of 38,500 genes) were expressed at significantly different (p≦0.05) levels between cells culture on PMEDSAH- and Matrigel-coated dishes. The up and down regulated genes were members of calcium signaling and focal adhesion pathways (Table 2 for genes with identified pathway; Table 3 for complete list of different regulated genes).
While biochemical, histological and genetic analysis showed that hESCs cultured on PMEDSAH and Matrigel are identical, differences with respect to initial proliferation times were observed between hESCs cultured on PMEDSAH and Matrigel coatings. Time between passages, i.e., the time it takes for a cell population to attain cell densities sufficient for passaging, was monitored during long-term cell culture experiments. On Matrigel-coated dishes, hESCs initially formed small colonies that increased in size and cell number over the next few days. Time between passages was 10±2 days, independent of the passage number. On the other hand, hESC colonies cultured on PMEDSAH coatings required culture for 19±3 days prior to the first passage. Thereafter, the time between passages gradually decreased until a plateau of 8±1 days was reached after passage number 7 ( FIG. 5E ). While the expression of pluripotency markers and the ability to form new colonies indicated that hESCs cultured on PMEDSAH coatings remained undifferentiated, the observed proliferation kinetics show that hESCs cultured on PMEDSAH coatings experienced adaptive growth profiles.
During the course of this study, 300 PMEDSAH hydrogel dishes originating from more than 20 different fabrication batches successfully supported attachment, growth and proliferation of undifferentiated hESCs during 20 continuous passages, an indication that these synthetic substrates can be synthesized in a reproducible and reliable manner. Moreover, long-term storage and UV-sterilization of polymer coated dishes did not affect their ability to support hESC growth and proliferation. In addition, hESCs cultured on PMEDSAH hydrogels were cryopreserved, thawed and successfully re-seeded onto fresh PMEDSAH-coated dishes. Under long-term culture conditions, cells supported by PMEDSAH coatings were phenotypically stable, expressed appropriate pluripotency markers, maintained a normal karyotype, and retained the capacity to differentiate.
Development of PMEDSAH hydrogel coatings as the first fully-defined synthetic substrate for long-term hESC culture represents important progress toward the elimination of xenogenic, undefined, and labile components from the insoluble microenvironment used for hESC derivation and culture. This rationally designed culture matrix establishes a radical, rather than incremental diversion from previously exploited hESC support matrices and provides one of the missing links in future development of fully defined hESC microenvironments. A major advantage of fully synthetic matrices over naturally derived substrates is that there physico-chemical makeup can be altered in highly controlled ways opening the possibilities for more detailed mechanistic studies that not only aim at understanding the mechanisms behind the novel capabilities of PMEDSAH, but ultimately lead to entirely defined microenvironments consisting of synthetic matrices and synthetic media.
TABLE 2
Pathway
Description
GenBank
Fold change
Jak-STAT signaling
Suppressor of cytokine signaling 3
AI244908
−1.88
pathway
Neuroactive ligand-
Neuropeptide FF receptor 2
AF257210
−1.75
receptor interaction
Calcium signaling pathway
Guanine nucleotide binding protein (G
NM_004297
−1.55
protein), alpha 14
Biosynthesis of steroids
Farnesyl-diphosphate farnesyltranferase 1
BF438300
−1.52
and terpenoid
Focal adhesion
Caveolin 1, caveolae protein, 22 kDa
NM_001753
−1.48
Purine, pyrimidine,
5′-nucleotidase cytosolic II
AV700081
−1.43
nicotinate and nicotinamide
metabolism
Jak-STAT signaling
Interleukin 13 receptor, alpha 1
U81380
−1.42
pathway, cytokine-cytokine
receptor interaction
Notch signaling pathway
Mastermind-like 2 ( Drosophila )
BF358386
−1.31
Calcium signaling
GNAS complex locus
AF107846
1.52
pathway, gap junction
TABLE 3
Pathway
Description
GenBank
Fold change
Annexin A3
M63310
−2.01
Jak-STAT signaling
Suppresor of cytokine signaling 3
AI244908
−1.88
pathway
Neuroactive ligand-
Neuropeptide FF receptor 2
AF257210
−1.75
receptor interaction
Glycoprotein M6A
D49958
−1.66
BC039495
−1.62
Calcium signaling pathway
Guanine nucleotide binding protein (G
NM_004297
−1.55
protein), alpha 14
Biosynthesis of steroids
Farnesyl-diphosphate farnesyltransferase 1
BF438300
−1.52
and terpenoid
Focal adhesion
Caveolin 1, caveolae protein, 22 kDa
NM_001753
−1.48
Caldesmon 1
NM_018495
−1.47
Purine, pyrimidine,
5′-nucleotidase cytosolic II
AV700081
−1.43
nicotinate and nicotinamide
metabolism
AL157496
−1.43
Glypican 6
AK021505
−1.42
Nuclear factor I/B
AI186739
−1.42
Jak-STAT signaling
Interleukin 13 receptor, alpha 1
U81380
−1.42
pathway, cytokine-cytokine
receptor interaction
Supervillin
NM_003174
−1.40
Chromosome 6 open reading frame 155
BF500942
−1.39
AF194537
−1.36
Notch signaling pathway
Mastermind-like 2 ( Drosophila )
BF358386
−1.31
Zinc finger protein 342
AA761573
1.30
Transcription elongation factor A (S-II)-like 2
AF063606
1.36
Cripto, PRL-1, cryptic family 1
AF312769
1.40
Calcium signaling
GNAS complex locus
AF107846
1.52
pathway, gap junction
Zinc finger and BTB domain containing 24
BC036731
1.55
TABLE 4
Product
Gene
Forward primer
Seq. ID
Reverse primer
Seq. ID
(bp)
Reverse Transcriptase
OCT3/4
ctgcagtgtgggtttcgggca
1
cttgctgcagaagtgggtggagga
2
168
NANOG
cggcttcctcctcttcctctatac
13
atcgatttcactcatcttcacacgtc
14
953
hTERT
cggaagagtgtctggagcaa
15
ggatgaagcggagtctgga
16
144
KRT18
tctgtggagaacgacatcca
9
ctgtacgtctcagctctgtga
10
378
NESTIN
cagctggcgcacctcaagatg
17
agggaagttgggctcaggactgg
18
209
BMP4
tgagcctttccagcaagttt
7
cttccccgtctcaggatatca
8
182
VE-CADHERIN
acgggatgaccaagtacagc
19
acacactttgggctggtagg
20
593
FLT-1
atcagagatcaggaagcacc
21
ggaacttcatctgggtccat
22
451
AFP
ccatgtacatgagcactgttg
23
ctccaataactcctggtatcc
24
357
GATA-4
ctccttcaggcagtgagagc
5
gagatgcagtgtgctcgtgc
6
574
ACTIN
atctggcaccacaccttctacaatgagctgcg
11
cgtcatactcctgcttgctgatccacatctgc
12
835
Real-time PCR
SOX2
gagagaaagaaagggagagaag
25
gagagaggcaaactggaatc
26
140
NANOG
tcctcctcttcctctatactaac
27
cccacaaatcaggcatag
28
112
OCT3/4
agtcagtgaacagggaatgg
29
tcgggattcaagaacctcg
30
131
Actin
gccgaggactttgattgc
31
gtgtggacttgggagagg
32
143
TABLE 5
Percentage (±SEM) of
Contact angle
attachment and colony
Percentage (±SEM) of cells positive to
Substrate
(in dry state)
formation
Oct3/4
Sox-2
Number of passages
Matrigel
Nm
98 ± 2
93 ± 3.6
89.2 ± 3.5
20
PMEDSAH
17.1 ± 1.2
15 ± 1
91.4 ± 3.4
92.06 ± 2.2
20-still in progress
PHEMA
56.0 ± 1.4
12 ± 1
0
0
2
PPEGMA
63.3 ± 3.1
5 ± 1
0
0
1
PSPMA
50.2 ± 4.1
14 ± 2
91 ± 5
2-still in progress
PLA
85.6 ± 1.9
0
—
—
0
PLGA
80.1 ± 3.4
0
—
—
0
PMAPDSAH
69.2 ± 4.7
7 ± 2
—
—
Still in progress
PCBMA
71.6 ± 4.9
0
PMETAC
40.5 ± 5.8
8 ± 1
90 ± 2.3
90 ± 5.2
2-still in progress
TCPS
Nm
8 ± 2
0
0
0
All publications and patents mentioned in the present application are herein incorporated by reference. Various modification and variation of the described methods and compositions of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims.
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The present invention provides methods and compositions for establishing and maintaining growth of undifferentiated stem cells. In particular, the present invention provides synthetic growth matrices for stem cells, wherein said cells are capable of going through multiple passages while remaining in an undifferentiated state.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 09/320,431, filed May 26, 1999, pending, which is a divisional of application Ser. No. 09/177,738, filed Oct. 23, 1998, now U.S. Pat. No. 6,194,783 B1, issued Feb. 27, 2001, which is a divisional of application Ser. No. 08/892,930, filed Jul. 15, 1997, now U.S. Pat. No. 6,222,271 B1, issued Apr. 24, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to a method of sputter deposition of an aluminum-containing film onto a semiconductor substrate, such as a silicon wafer. More particularly, the invention relates to using hydrogen gas with argon during the deposition of aluminum or aluminum alloys to form an aluminum-containing film which is resistant to hillock formation.
[0004] 2. State of the Art
[0005] Thin film structures are becoming prominent in the circuitry components used in integrated circuits (“ICs”) and in active matrix liquid crystal displays (“AMLCDs”). In many applications utilizing thin film structures, low resistivity of metal lines (gate lines and data lines) within those structures is important for high performance. For example with AMLCDs, low resistivity metal lines minimize RC delay which results in faster screen refresh rates. Refractory metals, such as chromium (Cr), molybdenum (Mo), tantalum (Ta), and tungsten (W), have resistances which are too high for use in high performance AMLCDs or ICs. Additionally, the cost of refractory metals is greater than non-refractory metals. From the standpoint of low resistance and cost, aluminum (Al) is a desirable metal. Furthermore, aluminum is advantageous because it forms an oxidized film on its outer surfaces which protects the aluminum from environmental attack, and aluminum has good adhesion to silicon and silicon compounds.
[0006] An aluminum film is usually applied to a semiconductor substrate using sputter deposition. Sputter deposition is generally performed inside the vacuum chamber where a solid slab (called the “target”) of the desired film material, such as aluminum, is mounted and a substrate is located. Argon gas is introduced into the vacuum chamber and an electrical field is applied between the target and the substrate which strikes a plasma. In the plasma, gases are ionized and accelerated, according to their charge and the applied electrical field, toward the target. As the argon atoms accelerate toward the target, they gain sufficient momentum to knock off or “sputter” atoms and/or molecules from the target's surface upon impact with the target. After sputtering the atoms and/or molecules from the target, the argon ions, the sputtered atoms/molecules, argon atoms and electrons generated by the sputtering process form a plasma region in front of the target before coming to rest on the semiconductor substrate, which is usually positioned below or parallel to the target within the vacuum chamber. However, the sputtered atoms and/or molecules may scatter within the vacuum chamber without contributing to the establishment of the plasma region and thus not deposit on the semiconductor substrate. This problem is at least partly resolved with a “magnetron sputtering system” which utilizes magnets behind and around the target. These magnets help confine the sputtered material in the plasma region. The magnetron sputtering system also has the advantage of requiring lower pressures in the vacuum chamber than other sputtering systems. Lower pressure within the vacuum chamber contributes to a cleaner deposited film. The magnetron sputtering system also results in a lower target temperature, which is conducive to sputtering of low melt temperature materials, such as aluminum and aluminum alloys.
[0007] Although aluminum films have great advantages for use in thin film structures, aluminum has an unfortunate tendency to form defects, called “hillocks.” Hillocks are projections that erupt in response to a state of compressive stress in a metal film and consequently protrude from the metal film surface.
[0008] There are two reasons why hillocks are an especially severe problem in aluminum thin films. First, the coefficient of thermal expansion of aluminum (approximately 23.5×10 −6 /° C.) is almost ten times as large as that of a typical silicon semiconductor substrate (approximately 2.5×10 −6 /° C.). When the semiconductor substrate is heated during different stages of processing of a semiconductor device, the thin aluminum film, which is strongly adhered to the semiconductor substrate, attempts to expand more than is allowed by the expansion of the semiconductor substrate. The inability of the aluminum film to expand results in the formation of the hillocks to relieve the expansion stresses. The second factor involves the low melting point of aluminum (approximately 660° C.), and the consequent high rate of vacancy diffusion in aluminum films. Hillock growth takes place as a result of a vacancy-diffusion mechanism. Vacancy diffusion occurs as a result of the vacancy-concentration gradient arising from the expansion stresses. Additionally, the rate of diffusion of the aluminum increases very rapidly with increasing temperature. Thus, hillock growth can be described as a mechanism that relieves the compressive stress in the aluminum film through the process of vacancy diffusion away from the hillock site, both through the aluminum grains and along grain boundaries. This mechanism often drives up resistance and may cause open circuits.
[0009] A hillock-related problem in thin film structure manufacturing occurs in multilevel thin film structures. In such structures, hillocks cause interlevel shorting when they penetrate or punch through a dielectric layer separating overlying metal lines. This interlevel shorting can result in a failure of the IC or the AMLCD. Such a shorted structure is illustrated in FIG. 11.
[0010] [0010]FIG. 11 illustrates a hillock 202 in a thin film structure 200 . The thin film structure 200 comprises a semiconductor substrate 204 , such as a silicon wafer, with a patterned aluminum layer 206 thereon. A lower dielectric layer 208 , such as a layer of silicon dioxide or silicon nitride, is deposited over the semiconductor substrate 204 and the patterned aluminum layer 206 . The lower dielectric layer 208 acts as an insulative layer between the patterned aluminum layer 206 and an active layer 210 deposited over the lower dielectric layer 208 . A metal line 212 is patterned on the active layer 210 and an upper dielectric layer 214 is deposited over the metal line 212 and the active layer 210 . The hillock 202 is shown penetrating through the lower dielectric layer 208 and the active layer 210 to short with the metal line 212 .
[0011] Numerous techniques have been tried to alleviate the problem of hillock formation, including: adding elements, such as tantalum, cobalt, nickel, or the like, that have a limited solubility in aluminum (however, this generally only reduces but not eliminates hillock formation); depositing a layer of tungsten or titanium on top or below the aluminum film (however, this requires additional processing steps); layering the aluminum films with one or more titanium layers (however, this increases the resistivity of the film); and using hillocks resistant refractory metal films such as tungsten or molybdenum, rather than aluminum (however, as previously mentioned, these refractory metals are not cost effective and have excessive resistivities for use in high performance ICs and AMLCDs).
[0012] In particular with AMLCDs, and more particularly with thin film transistor-liquid crystal displays (“TFT-LCDs”), consumer demand is requiring larger screens, higher resolution, and higher contrast. As TFT-LCDs are developed in response to these consumer demands, the need for metal lines which have low resistivity and high resistance to hillock formation becomes critical.
[0013] Therefore, it would be advantageous to develop an aluminum-containing material which is resistant to the formation of hillocks and a technique for forming an aluminum-containing film on a semiconductor substrate which is substantially free from hillocks, while using inexpensive, commercially-available, widely-practiced semiconductor device fabrication techniques and apparatus and without requiring complex processing steps.
SUMMARY OF THE INVENTION
[0014] The present invention relates to a method of introducing hydrogen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate, including but not limited to glass, quartz, aluminum oxide, silicon, oxides, plastics, or the like, and to the aluminum-containing films resulting therefrom.
[0015] The method of the present invention involves using a standard sputter deposition chamber, preferably a magnetron sputter deposition chamber, at a power level of between about 1 and 4 kilowatts (KW) of direct current power applied between a cathode (in this case the aluminum target) and an anode (flat panel display substrate—i.e., soda lime glass) to create the plasma (after vacuum evacuation of the chamber). The chamber is maintained at a pressure of between about 1.0 and 2.5 millitorr with appropriate amounts of argon gas and hydrogen gas flowing into the chamber. The argon gas is preferably fed at a rate between about 50 and 90 standard cubic centimeters per minute (“sccm”). The hydrogen gas is preferably fed at a rate between about 90 and 600 sccm. The ratio of argon gas to hydrogen gas is preferably between about 1:1 and about 1:6. The films with higher hydrogen/argon ratios exhibited smoother texture. The deposition process is conducted at room temperature (i.e., about 22° C.).
[0016] The aluminum-containing films resulting from this method have an average oxygen content between about 1 and 5% (atomic) oxygen in the form of aluminum oxide (Al 2 O 3 ) with the remainder being aluminum. The aluminum-containing films formed under the process parameters described exhibit a color similar to but slightly darker than pure aluminum metal. The most compelling attribute of the aluminum-containing films resulting from this method is that they are hillock-free, even after being subjected to thermal stresses.
[0017] Although the precise mechanical and/or chemical mechanism for forming these aluminum-containing films is not completely understood, it appears that the hydrogen gas functions in the manner of a catalyst for delivering oxygen into the aluminum-containing films. The oxygen gas comes from residual air within the vacuum chamber remaining after the vacuum chamber has been evacuated. Although the amount of residual oxygen in the air of the evacuated vacuum chamber is small, there is a relatively large percentage of oxygen present in the deposited aluminum-containing films. In experiments by the inventors, oxygen gas was introduced into the vacuum chamber, without any hydrogen gas being introduced (i.e., only oxygen gas and argon gas introduced). The resulting films deposited on the substrate did not have a measurable amount (by x-ray photoelectron spectroscopy) of oxygen present.
[0018] As stated previously, oxygen is present in the deposited aluminum-containing film in the form of aluminum oxide. However, aluminum oxide is an insulator. It is counter-intuitive to form an insulative compound (which should increase the resistivity of the film) in a film which requires very low resistivity. However, it has been found that the formation of the aluminum oxide does not interrupt the conducting matrix of aluminum grains within the aluminum-containing film. Thus, the resistivity of the aluminum-containing film is surprisingly low.
[0019] Aside from being substantially hillock-free and having a low resistivity (i.e., high conductivity), the resultant aluminum-containing films have additional desirable properties including low roughness, low residual stress, and good mechanical strength (as determined by a simple scratch test compared to pure aluminum or by the low compressive stress (between about −5×10 8 and −1×10 9 dyne/cm 2 ), which is considered to be an indication of high scratch resistance). Measurements of the aluminum-containing films have shown that the roughness before and after annealing is low compared to pure aluminum (about 600-1300 Å before annealing and 400-1000 Å after annealing). Low roughness prevents stress migration, prevents stress-induced voids, and, consequently, prevents hillock formation. Additionally, low roughness allows for better contact to other thin films and widens the latitude of subsequent processing steps, since less rough films result in less translation of crests and valleys in the film layers deposited thereover, less diffuse reflectivity which makes photolithography easier, no need to clad the aluminum in the production of AMLCDs (rough aluminum traps charge which effects electronic performance [i.e., high or variable capacitance]), and more uniform etching.
[0020] The mechanical strength of the aluminum-containing films resulting from the process of the present invention is higher than conventionally sputtered thin films of aluminum and some of its alloys. A high mechanical strength results in the resulting aluminum-containing films being resistant to both electromigration and stress induced voiding.
[0021] This combination of such properties is superior to that of thin films of aluminum and its alloys which are presently known. These properties make the aluminum-containing films of the present invention desirable for electronic device interconnects. These properties are also desirable in thin films for optics, electro-optics, protective coatings, and ornamental applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which:
[0023] [0023]FIGS. 1 and 2 are illustrations of scanning electron micrographs of an aluminum thin film produced by a prior art method before annealing and after annealing, respectively;
[0024] [0024]FIGS. 3 and 4 are illustrations of scanning electron micrographs of an aluminum thin film (Test Sample 1) produced by a method of the present invention before annealing and after annealing, respectively;
[0025] [0025]FIGS. 5 and 6 are illustrations of scanning electron micrographs of an aluminum thin film (Test Sample 2) produced by a method of the present invention before annealing and after annealing, respectively;
[0026] [0026]FIG. 7 is an x-ray photoelectron spectroscopy graph showing the oxygen content through the depth of an aluminum-containing film produced by a method of the present invention;
[0027] [0027]FIG. 8 is a graph of roughness measurements (by atomic force microscopy) of various aluminum-containing films made in accordance with methods of the present invention;
[0028] [0028]FIG. 9 is a cross-sectional side view illustration of a thin film transistor utilizing a gate electrode and source/drain electrodes formed from an aluminum-containing film produced by a method of the present invention;
[0029] [0029]FIG. 10 is a schematic of a standard active matrix liquid crystal display layout utilizing column buses and row buses formed from an aluminum-containing film produced by a method of the present invention; and
[0030] [0030]FIG. 11 is a cross-sectional side view illustration of interlevel shorting resulting from hillock formation.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The method of the present invention preferably involves using a conventional magnetron sputter deposition chamber within the following process parameters:
Power (DC): between about 1 and 4 KW Pressure: between about 1.0 and 2.5 millitorr Argon Gas Flow Rate: between about 50 and 90 sccm Hydrogen Gas Flow Rate: between about 90 and 600 sccm Argon:Hydrogen Gas Ratio: between about 1:1 to 1:6
[0032] The operation of the magnetron sputter deposition chamber generally involves applying the direct current power between the cathode (in this case the aluminum target) and the anode (substrate) to create the plasma. The chamber is maintained within the above pressure range and with an appropriate mixture of argon gas and hydrogen gas. The aluminum-containing films resulting from this method have between about a trace amount and 12% (atomic) oxygen in the form of aluminum oxide (Al 2 O 3 ) with the remainder being aluminum.
[0033] It is believed that the primary hillock prevention mechanism is the presence of the hydrogen in the system, since it has been found that even using the system with no oxygen or virtually no oxygen present (trace amounts that are unmeasurable by present equipment and techniques) results in a hillock-free aluminum-containing film. It is also believed that the presence of oxygen in the film is primarily responsible for a smooth (less rough) aluminum-containing film, since roughness generally decreases with an increase in oxygen content in the film.
[0034] It is understood that the sputter deposition system of the present invention will usually always have a trace amount of oxygen. This trace amount of oxygen will be incorporated into the aluminum containing film in the presence of hydrogen, even though the very low amount of oxygen within the aluminum film cannot be detected by present analysis equipment. This trace amount of oxygen may come from two potential sources: incomplete chamber evacuation and/or inherent trace oxygen contamination in the argon or hydrogen gas feeds. The first source, incomplete chamber evacuation, comes from the fact that no vacuum is a perfect vacuum. There will also be some residual gas in the system, whether a purge gas or atmospheric gas, no matter how extreme the vacuum evacuation. The second source is a result of inherent trace gas contamination in industrial grade gases, such as the argon and hydrogen used in the present invention. The oxygen impurity content specification for the argon gas used is 1 ppm and the hydrogen gas is 3 ppm. Thus, a high flow rate of the argon and hydrogen into the system will present more trace oxygen to be scavenged from the gas streams and integrated into the aluminum-containing film. Therefore, even though present equipment cannot measure the content of the oxygen in the aluminum-containing film when it exists below 0. 1%, a trace amount below 0.1% may be incorporated into the aluminum-containing film.
EXAMPLE 1
[0035] A control sample of an aluminum film coating on a semiconductor substrate was formed in a manner exemplary of prior art processes (i.e., no hydrogen gas present) using a Kurdex-DC sputtering system to deposit aluminum from an aluminum target onto a soda-lime glass substrate.
[0036] The substrate was loaded in a load lock chamber of the sputtering system and evacuated to about 5×10 −3 torr. The load lock was opened and a main deposition chamber was evacuated to about 10 −7 torr before the substrate was moved into the main deposition chamber for the sputtering process. The evacuation was throttled and specific gases were delivered into the main deposition chamber. In the control deposition, argon gas alone was used for the sputtering process. Once a predetermined amount of argon gas stabilized (about 5 minutes) in the main deposition chamber, about 2 kilowatts of direct current power was applied between a cathode (in this case the aluminum target) and the anode (substrate) to create the plasma, as discussed above. The substrate was moved in front of the plasma from between about 8 and 10 minutes to form an aluminum-containing film having a thickness of about 1800 angstroms.
[0037] Table 1 discloses the operating parameters of the sputtering equipment and the characteristics of the aluminum film formed by this process.
TABLE 1 Control Sample Sputtering Process Parameters Power (KW) 2 Pressure (mtorr) 2.05 Gas Flow (sccm) Argon = 90 Characterization Parameters and Properties Thickness (Å) 1800 Stress (dyne/cm 2 ) (compressive) −4.94 × 10 8 (C) Roughness (Å) 1480 (unannealed) 2040 (annealed) Resistivity (μΩ-cm) approx. 2.7 Grain Size (Å) 1000-1200 Hillock Density approx. 2 to 5 × 10 9 /m 2
[0038] The measurements for the characterization parameters and properties were taken as follows: thickness—Stylus Profilometer and scanning electron microscopy; stress—Tencor FLX using laser scanning; roughness—atomic force microscopy; resistivity—two point probe; grain size—scanning electron microscopy; and hillock density—scanning electron microscopy.
[0039] [0039]FIG. 1 is an illustration of a scanning electron micrograph of the surface of the aluminum film produced under the process parameters before annealing. FIG. 2 is an illustration of a scanning electron micrograph of the surface of the aluminum-containing film produced under the process parameters after annealing. Both FIGS. 1 and 2 show substantial hillock formation (discrete bumps on the aluminum film surface) both before and after annealing.
EXAMPLE 2
[0040] Two test samples (test sample 1 and test sample 2) of an aluminum film coating on a semiconductor substrate were fabricated using the method of the present invention. These two test samples were also formed using the Kurdex-DC sputtering system with an aluminum target depositing on a soda-lime glass substrate.
[0041] The operating procedures of the sputtering system were essentially the same as the control sample, as discussed above, with the exception that the gas content vented into the main deposition chamber included argon and hydrogen. Additionally, the pressure in the main deposition chamber during the deposition and the thickness of the aluminum-containing film was varied from the control sample pressure for each of the test samples.
[0042] Table 2 discloses the operating parameters of the sputtering equipment and the characteristics of the two aluminum films formed by the process of the present invention.
TABLE 2 Test Sample 1 Test Sample 2 Sputtering Process Parameters Power (KW) 2 2 Pressure (mtorr) 2.4 2.5 Gas Flow (sccm) Argon = 90 Argon = 90 Hydrogen = 200 Hydrogen = 400 Characterization Parameters and Properties Thickness (Å) 1600 1500 Stress (dyne/cm 2 ) −1.12 × 10 8 (C) −5.6 × 10 8 (C) (compressive) Roughness (Å) (after 800 540 annealing) Resistivity (μΩ-cm) 5.5 6.0 Grain Size (Å) 1000-1200 1000-1200 Hillock Density no hillocks present no hillocks present
[0043] [0043]FIG. 3 is an illustration of a scanning electron micrograph of the surface of the Test Sample 1 before annealing. FIG. 4 is an illustration of a scanning electron micrograph of the surface of the Test Sample 1 after annealing. FIG. 5 is an illustration of a scanning electron micrograph of the surface of the Test Sample 2 before annealing. FIG. 6 is an illustration of a scanning electron micrograph of the surface of the Test Sample 2 after annealing. As it can be seen from FIGS. 3 - 6 , no hillocks formed on either sample whether annealed or not.
EXAMPLE 3
[0044] A number of aluminum-containing films were made at different ratios of Ar/H 2 and various system pressures were measured for oxygen content within the films. The power at 2 KW. The oxygen content was measure by XPS (x-ray photoelectron spectroscopy). The results of the measurements are shown in Table 3.
TABLE 3 Sample Ar/H 2 Pressure Oxygen Content Number (sccm) Ar/H 2 Ratio (millitorr) Range (atomic %) 1 90/400 0.225 2.50 5-10 2 90/200 0.450 2.40 5-10 3 50/90 0.556 1.27 3 4 90/90 1.000 2.15 <1%
[0045] An XPS depth profile for sample 3 (Ar/H 2 (sccm)=50/90, pressure=1.27) is illustrated in FIG. 7 which shows the oxygen content to be on average about 3% (atomic) through the depth of the film.
[0046] [0046]FIG. 8 illustrates the roughness of the two aluminum-containing film samples. As FIG. 8 generally illustrates, the higher the amount of hydrogen gas delivered to the sputter deposition chamber (i.e., the lower the Ar/H 2 ratio—x-axis), the smoother the aluminum-containing film (i.e., lower roughness—y-axis). It is noted that the “jog” in the graph could be experimental error or could be a result of the difference in the amount of argon introduced into the system or by the difference in the system pressure for sample number 3.
[0047] [0047]FIG. 9 illustrates a thin film transistor 120 utilizing a gate electrode and source/drain electrodes which may be formed from an aluminum-containing film produced by a method of the present invention. The thin film transistor 120 comprises a substrate 122 having an aluminum-containing gate electrode 124 thereon which may be produced by a method of the present invention. The aluminum-containing gate electrode 124 is covered by an insulating layer 126 . A channel 128 is formed on the insulating layer 126 over the aluminum-containing gate electrode 124 with an etch stop 130 and contact 132 formed atop the channel 128 . An aluminum-containing source/drain electrode 134 which may be produced by a method of the present invention is formed atop the contact 132 and the insulating layer 126 , and contacts a picture cell electrode 136 . The aluminum-containing source/drain electrode 134 is covered and the picture cell electrode 136 is partially covered by a passivation layer 138 .
[0048] [0048]FIG. 10 is a schematic of a standard active matrix liquid crystal display layout 150 utilizing column buses 152 and row buses 154 formed from an aluminum-containing film produced by a method of the present invention. The column buses 152 and row buses 154 are in electrical communication with pixel areas 156 (known in the art) to form the active matrix liquid crystal display layout 150 .
[0049] Having thus described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations are possible without departing from the spirit or scope thereof.
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Aluminum-containing films having an oxygen content within the films. The aluminum-containing film is formed by introducing hydrogen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, TABLE, OR COMPUTER PROGRAM
Not Applicable
BACKGROUND OF INVENTION
People wear clothing for three principal reasons:
(1) To protect themselves from the environment,
(2) for modesty, and
(3) To respond to the dictates of fashion.
To accomplish any of these purposes, it is vital that the garments do not fall off of one's body. And for that to be insured, they must have a certain degree of mechanical integrity internally, and they must be made in some fashion that permits taking advantage of various anatomical features of a person's body in one way or another.
There have been, to date, only four general methods used, singly or in combination, to accomplish this vital task of keeping garments on the wearer's body. These methods may be termed wrapping, clamping, draping, and gluing. My invention presents a novel fifth means for securing garments on the wearer's body—one that is particularly appropriate for use in swimwear and underwear, but which may also find utility in many other types of garment.
Applicant has uncovered no means for retaining a garment on a wearer's body other than the four specified above [wrapping, clamping, draping, and gluing].
The purposes for holding garments on one's body are, as stated above, to protect one from the environment, for modesty, and to conform to the dictates of fashion. And, of course, to avoid losing them altogether.
Modesty or decency are terms that vary by culture. But in almost all cultures the minimum requirements include covering the external genitalia [penis and testicles for men, and vaginal lips for women], plus the anus. In many cultures women are also required to cover their breasts (at least the nipples and areolae). Some cultures require more coverage than this minimum, but for swimwear and underwear in particular, any such additional coverage is fast becoming optional.
The thong is a well-known variation on the bikini in which most of the back panel of the bottom is removed, and in the most extreme versions includes only a narrow strap connecting the bottom of the front panel down underneath the crotch and up to the waist band.
Like all swimsuits before them, the bikini, thong, and other similar swimsuit designs depend entirely on the principle of wrapping [and to the extent that the material is stretchy, on clamping] to keep the suit on the wearer's body.
BRIEF SUMMARY OF INVENTION
In accordance with the principles of the invention, garments include one or more extension(s) of a design that permits the extension to be inserted into a bodily orifice [or into more than one orifice at once]. For swimsuits and underpants, for example, the orifice to be used would be one's anus [or in the case of a woman, her vagina and/or her anus]. The extension is secured to the garment in a manner such that its location and orientation to the rest of the garment is maintained—generally by attaching the extension to a somewhat stiff frame. The frame is then wrapped by the fabric of the garment. In the case of swimsuits or underpants, the frame can usefully be extended to wrap around the pelvis from a small distance above the pubis to just behind the anus—thereby gaining added leverage from its snapped-in extension.
This strategy provides the garment with a secure means of mechanical anchorage to the wearer's body. Any article of apparel, of any design, that utilizes this means for assisting in keeping it on the wearer's body is included within the scope of this invention.
In some embodiments of this invention a “one-sided snap” feature is provided. This means that in the putting on of the garment, one would, in essence, “snap” it into a bodily orifice, and to take it off one would un-snap it from that orifice. As with ordinary snap fasteners, this implies that during the snapping and unsnapping process, the piece being inserted and/or the object into which it is inserted distorts in shape temporarily, with the insert finally occupying a wider space than the opening through which it was pushed. But in sharp contrast to ordinary snap fasteners in which one connects two portions of the snap fastener together or separates them, in order to close or open a gap in the garment, in this case one side of the “snap” is a part of the wearer's bodily anatomy.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows a woman's swimsuit bottom utilizing this invention as the only means of garment attachment. In the example shown here, the garment extension is meant for insertion into a woman's vagina, and it attaches to a frame in order to hold the remainder of the garment against the contours of her pelvis. Here, and in FIG. 4 and FIG. 5, the garment fabric is rendered as if it were translucent, in order to reveal the details of the frame and extension construction.
FIG. 2 shows the frame alone, without the fabric covering or the extension, in order to make the frame's construction fully evident.
FIG. 3 ( a ) shows in cross-section view the central portion of the frame and extension for the garment in FIG. 1 . This only shows one way that a vaginal-insert extension might be formed. Some other possibilities are shown in FIG. 3 ( b ), FIG. 3 ( c ), FIG. 3 ( d ), and FIG. 3 ( e ).
FIG. 4 shows the equivalent man's swimsuit—which, of necessity, uses an anal-insert extension, and also has various other differences from that in FIG. 1 .
FIG. 5 shows a variation of the woman's garment in FIG. 1, this time adding additional material to the front panel and a cord around the waist.
FIG. 6 shows another variation of the garment in FIG. 1, intended for a woman who wishes to expose her entire backside, but at least minimally cover her breasts as well as her genitals—and do so with a one-piece bathing suit.
FIG. 7 shows yet another variation on the garment in FIG. 6, in this case including wrapping around the torso to ensure the suit's coverage of the breasts even during vigorous physical activity.
FIG. 8 shows a very different embodiment of this invention, in this case to a hat. Here a very top-heavy hat is balanced on the head, and is kept from slipping off by anchoring extensions that are snapped into the ears.
FIG. 9 shows another variation of the garment in FIG. 1, with two inserted extensions, suitable for insertion into both the wearer's vagina and her anus. This design provides minimum coverage with maximum security.
Like components of the various embodiments herein are designated by the same numerals in all the figures to facilitate comparisons between those figures.
DETAILED DESCRIPTION OF THE INVENTION
In this section I shall describe in detail several preferred embodiments of my invention, and further I shall mention several additional useful embodiments, and I shall detail some of the benefits of using this invention in these ways.
FIG. 1 shows a woman's bathing suit bottom in accordance with the principles of this invention. The extension ( 22 ) shown is for vaginal insertion, and it attaches to semi-rigid frame ( 10 ) at the vaginal-insert attachment point ( 12 ). The frame extends rearward past the anus. An optional attachment point ( 11 ) is provided for use with an anal-insert extension-in addition to, or instead of—the vaginal-insert extension. The front end of the frame extends forward and up, conforming to the front of the pelvis, ending just past the pubis. The frame surrounds the vaginal lips and anus, and it bears on the front and crotch surfaces of the pelvis plus a portion of the inner surfaces of the buttocks. It does not bear on the inside of the woman's legs. The frame is slipped into a pocket formed in the fabric ( 40 ) which makes up the visible portion of the garment, which thus appears to be quite like a normal bathing suit, albeit a very small one with no obvious means of support.
If a woman shaves off all of her pubic hair, a considerably smaller swimsuit can be constructed and still meet all of the normal requirements for decency. FIG. 9 shows one such design, in this case one which does not require any frame at all. Here there are two extensions to the garment, one adapted for insertion into the vaginal orifice ( 22 ) and one adapted for insertion into the anal orifice ( 21 ). Since each such extension covers the orifice into which it is inserted plus a small amount of skin around that orifice, and each holds one end of the very small fabric panel ( 40 ) spanning the two orifices, this design meets all the requirements of minimal decency without needing anything other than the fabric panel and the two inserted extensions. Furthermore, this design is doubly-secure against any inadvertent indecent exposure, inasmuch as it is held to the body in two separate, but closely-spaced locations.
Having the frame readily removable from the fabric permits several benefits of interest especially to people wishing to use the swimsuit while traveling. These include (a) ease of cleaning all the parts separately, (b) interchangeable coverings—which implies being able to carry a multitude of bathing suits with only one frame and its extension(s), in a very small space, at low cost, and with minimal weight. Not all the covering fabric forms need be of the same design—for example, the various suits shown in FIG. 5, FIG. 6, and FIG. 7 all use the same frame as the one in FIG. 1 .
Since the suit in FIG. 1 has only the one point of attachment to the body, it is important that it maintain its shape and that it remain in a fixed orientation relative to the extension. The frame and its attachment points [shown in FIG. 2 without the extension or covering fabric, for greater clarity] in concert with the design of the vaginal-insert extension [detailed in FIG. 3 ( a )] provides these features.
FIG. 2 shows a particular design for the frame in which it is constructed from stainless steel wire, with cross pieces for the extension attachment points, made of similar wire, welded in place as shown. In this figure one can see that the vaginal—insert attachment point is lowered below the level of the surrounding frame, while the anal—insert attachment point is raised above that surrounding level-both of which are done in order to accommodate the shape of the pelvis and its covering skin and the external vaginal lips.
FIG. 3 ( a ) is a vertical-medial-plane, front-to-back cross-sectional view of just the central portion of the suit shown in FIG. 1 . This shows the details of construction for this particular design of vaginal-insert extension, and its means of attachment to this particular design of frame. This extension ( 22 ) is formed as a hollow resilient bulb of soft rubber or plastic, with a skirt at the bottom end. The surface of the extension is soft, smooth, and washable to avoid any possibility of damage to the sensitive surfaces inside the vagina. These properties render it unlikely to retain harmful microorganisms and makes cleaning it very easy. When the extension is in place, the lower portion of the bulbous part bears on the inside of the muscular ring surrounding the vaginal opening, thus keeping the suit in close contact with the wearer's body. The bulb's skirt flares out over the frame-attachment mechanism, and protects the wearer from contact with that hard surface, plus it protects the suit from possible fluid leakage from the vagina.
Embedded at the center-bottom of the skirt on this design of vaginal-insert extension is a hard plastic disk ( 23 ) that has fixed in it a stainless steel threaded rod ( 24 ) that extends outside the disk a short distance. There is a port in the bottom of the skirt connected to the interior of the bulb, to permit squeezing out the air in the bulb during insertion or removal of the extension. The rod ( 24 ) screws into a stainless steel nut which is welded to the vaginal-insert attachment-support cross piece of the frame ( 10 ) to form the vaginal-insert attachment point ( 12 ). Other means of attaching and removing the extension [e.g., a quick-disconnect fitting] are, of course, possible and are also to be considered as covered by this patent application.
FIG. 3 ( b ) shows one variation on this design for the vaginal-insert extension. This variation has the top of the bulb removed entirely. Thus, this extension ( 25 ) has a trumpet-like shape, which can be folded for insertion or removal, and which—while in the vagina—will flare out and bear on the inner surface of the ring of muscles surrounding the vaginal opening. [Such an extension does not have and would not need the exit port for air shown in FIG. 3 ( a ).] The extension shown in FIG. 3 ( b ) also has an (optional) socket ( 26 ) which could be used to retain a tampon, for use during a menstrual period, or for other purposes.
A young woman or girl might need a very small extension, whereas a woman who is sexually active might need a larger one, and a woman who has had several children might need a still larger one.
The vaginal-insert extension could be removable, as is shown here, or it could be formed as a part of the frame before insertion in the fabric which comprises the garment. The deciding factors will likely be cost of manufacture versus convenience and flexibility. If a garment accepts removable extensions, it can accept a range of them in different sizes and with different shapes or other features.
FIG. 3 ( c ), shows another example of a vaginal-insert extension ( 27 ), in this instance one that is hollow and is provided with a reclosable opening ( 28 ). [In the design pictured in FIG. 3 ( c ), the top of the bulbous part snaps off of the lower part, and when snapped in place, the two parts join along the line ( 28 ) with a water-tight seal.] Further, there is a valve ( 29 ) located on the underside of the extension's skirt, which valve can be operated by the wearer through the fabric covering of the suit. This valve permits one to expel the air inside the bulb to facilitate insertion of it, and then—after the bulb has expanded inside the wearer's body—to seal the bulb, so water cannot leak inside during swimming, for example. When it is time to remove the extension, the wearer can easily open the valve, once again permitting the bulb to be compressed easily during its withdrawal. This design could permit the wearer to store a few small objects [e.g., a key, ID, and some parking meter change] inside it and keep those items dry even while swimming.
Yet another design, based on the previous one—and shown here in FIG. 3 ( d ) with a lower-profile bulb ( 30 )—has a battery-operated vibrator ( 31 ) which, with its battery ( 32 ), is built into the bulbous part of the extension. A means of opening and resealing the bulb [similar to that shown in FIG. 3 ( c ) as component ( 28 )] permits replacing the battery as necessary. The base of the skirt has, as before, a valve ( 29 ) which can be opened to let air in or out, and which can be closed to exclude water. In addition, it also has an electrical switch ( 33 )—operable from outside the suit, through the fabric covering—to permit the wearer to turn the vibrator on or off.
FIG. 3 ( e ) shows yet another variation in the design of a vaginal-insert extension, in which the portion inside the vagina merely “hooks” onto the muscular ring surrounding the vaginal opening only on one side.
To reduce the frequency with which the extension must be cleaned, and to accommodate any user concerns about hygiene, the extension may be covered by a disposable, suitably formed “cot” [similar to a condom or finger cot, but differing in shape, as necessary]. This will be particularly important for pre-purchase trials of these garments.
Most, if not all, of the foregoing variations and comments regarding suitable materials and designs to be used also apply to any extension intended for insertion into a person's anus.
FIG. 4 is a drawing of a man's minimalist bathing suit. This is very similar to the design shown in FIG. 1, with the following differences, which are required to accommodate the man's different anatomy. First, the vaginal-insert cross piece with its extension attachment point ( 12 ) is missing from the frame ( 10 ). Second, the frame surrounds the testicles and penis [and, as before, it bears on the pelvis, and not against the insides of the legs]. Third, the insert ( 21 ) is designed for anal insertion and is attached to the anal-insert attachment point ( 11 ). Fourth, the fabric ( 40 ) is enlarged to form a pouch ( 41 ) of a sufficient size to accommodate the penis and testicles comfortably. The frame may (optionally) be extended upward on the front of the pelvis to a height above the end of the penis when it is engorged.
The anal-insert extension could be made available in various sizes, depending on the user's preference and experience. A short insert would be held in by the external sphincter, under voluntary control. A longer insert would also engage the higher-up, non-voluntarily controlled sphincter, which might give greater security from having the garment fall off, at the cost of greater difficulty of insertion. Disposable cots to cover the anal-insert extension would likely be desired at least as much as those to cover the vaginal-insert extensions.
FIG. 5 shows the swimsuit from FIG. 1 with the fabric covering ( 40 ) extended up toward the waist where it wraps around a cord or sash ( 42 ) that ties around the waist. [Similarly, the fabric itself could simply extend around the waist, as is often done in conventional swimsuits, without any opening in the waistband.] This would appear to the casual observer very much like an extreme thong or g-string swimsuit, but on careful examination it will be seen to lack the rear string or panel entirely.
FIG. 6 shows a different way of extending the swimsuit shown in FIG. 1 . In this case the swimsuit has chains ( 43 ) attached to the top-front corners of the frame ( 10 ) [or, optionally, the chains could attach to the top of an extended fabric panel, much as the cord does in FIG. 5 ] and continuing upward to where they attach to smaller panels ( 44 ) that cover the nipples and areolae only [as shown in this figure], or that could be formed as full cups to hold the breasts. These panels or cups are then connected by another chain ( 45 ) going around the back of the neck. This design would give sufficient coverage in front and under the crotch to meet all the usual decency requirements, while presenting an appearance of total nudity from the rear. [The neck chain might appear to be a necklace, or if the woman has even moderately long hair, it would be covered completely in the rear.]
An obvious variation on this design would substitute fabric strips, which could be simply extensions of the fabric ( 40 ) that covers the frame at the crotch, for some or all of the chains.
FIG. 7 shows a modification of the swimsuit in FIG. 6 in which the chains ( 43 ) [or fabric strips] connecting the bottom portion to the top wrap around the torso, and—to allow for the angle at which they then will connect to the bra portions ( 44 )—the neck chain crosses in front of the throat, as well as going around the back of the neck. Optionally, the chains ( 43 ) could be replaced with transparent plastic straps, thus preserving the appearance from the rear of total nudity.
This design gives almost the same, full exposure as the previous one, plus it secures the bra panels much more firmly, thus permitting the wearer to engage in vigorous activities [swimming, beach volleyball, and the like] without fear of losing her decency-mandated body coverage.
A quite obvious group of other embodiments include underwear formed in a fashion quite similar to the swimsuits shown in FIG. 1 and FIG. 4, or with front panel extensions and waistbands [probably fabric instead of cord but otherwise as shown in FIG. 5 ]. One key advantage to women's and men's underpants resembling the swimsuits in FIG. 1 and FIG. 4, respectively—or the same designs but modified as shown in FIG. 5, using a flat fabric panel around the waist—is that their use would totally preclude the unsightly appearance of “visible panty lines” in tight pants or other garments worn over them.
Similarly, most conventional one-piece swimsuits could be modified by omitting the panel that covers the buttocks, and instead securing the lower front pelvis-covering panel under the crotch by use of this invention.
Thong, g-string and “slingshot” swimsuits and underwear could all be modified similarly, giving the benefit of no visible panty lines in underwear and greater exposure for swimwear. [The “slingshot” swimsuit is merely a thong with the sides raised over the shoulders, to give a sideless look—and sometimes with the front straps, so formed, covering the breasts. The modification contemplated here would join the two front straps behind the wearer's neck, and completely eliminate all of the rear portion of the suit.]
A “frontless” variation is also possible, in which the basic swimsuit shown in FIG. 1 has a fabric panel covering all or a portion of the buttocks before attaching to a waistband, but lacks any direct connection between the waistband and the front panel. Or the rear panel could go up the back, divide around the sides, and then connect to the bottom of breast cups or panels. This would create a swimsuit that looks much like that in FIG. 7, except that there would be no direct connection to the front of the bottom, and this design covers some or all of the buttocks.
A significant benefit of both swimwear and underwear utilizing this invention is that they permit the wearer to remove the swimsuit [or underpants] from the crotch region quickly and easily, thus permitting one to urinate and/or defecate without having to remove the entire suit. Furthermore, this can be done without having to lift either leg, thus allowing one to minimize the risk of falling over, and preclude having to lean on something as one removes or replaces one's swimsuit or underpants.
Other variations in the embodiments of this invention include backless slacks [not covering the buttocks and which, if provided with some transparent straps connecting around the back of the legs to hold the sides of the material covering the front of the legs, will appear not to have any back to the legs as well], a truly backless sundress, or even a backless formal gown or tuxedo, or any other type of garment that normally surrounds the pelvis.
A possibly less-obvious additional embodiment is one that utilizes other orifices than the vagina or anus. FIG. 8 shows a woman wearing a very top-heavy headdress. Normally, such a large and top-heavy headdress is worn only by women who have shaved their heads or who have cut their hair very short. Those headdresses are conventionally built with a closely-fitted skull cap and scarf combination, with the scarf tying very tightly around the skull-in the process trapping and compressing the external ears, possibly quite painfully. And those headdresses are only able to stay in place if the wearer is very careful to hold her head very nearly vertical and to avoid any quick movements.
In contrast, the woman in FIG. 8 is shown with long hair and with her head tilted rather rakishly. This is possible because of the novel design of the headdress attachment. In addition to a reduced area skull cap ( 50 ), it includes two semi-rigid extensions ( 51 ) of that cap that extend out and down over the external ears and then inward where they snap into the ear canals. [These extensions may have holes in them to permit the wearer to hear more-or-less normally.]
With five or six bearing points [just in front of the crown of the head, on both sides of the rear base of the skull, in both ears, and possibly also just behind the crown] this headdress is quite securely held in place-even on a person having a great deal of hair-thus enabling its use by more people, minimizing the care the wearer must exercise, and permitting a wider range of motions. And it permits one to take the headdress on or off easily and quickly, simply by flexing the extensions ( 51 ) out to either side, then lifting the headdress on or off.
In all of the foregoing, any mention of fabric is intended to include alternative materials such as woven or non-woven fiber-based materials, real or imitation leather, plastic, wire mesh or fine chain mail, etc.
The foregoing description covers example embodiments, but it is not an exhaustive listing of all possible embodiments. Therefore, whereas many additional variations and modifications will readily occur to one skilled in the art, all such suitable modifications or variations are to be considered as falling within the scope of this invention.
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An article of clothing including extensions for insertion into a body cavity permit swimsuits, undergarments, and several other types of clothing to be secured in place with a minimum of fabric, as described. The articles are made dimensionally stable to maintain their position and orientation relative to the wearer's body.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention deals with a control method which incorporates the changes of the flow through the process to be controlled with determination of the control signal to the control valve or other actuator. The invention deals also with an apparatus for implementation of the method.
2. Description of the Prior Art
Control of various process quantities is implemented in industry by means of unit controllers which are commercially obtainable. When the control is implemented with devices of other type like e.g. with a computer in which the control tasks are concentrated, the control calculations generally follow known standard principles. It is characteristic of these control methods, e.g. that each process quantity under control is controlled separately and the effect of other varying quantities on the properties of the control loop and on the operation of the control is neglected. Changes of the flow through the production process disturb considerably the control of other process quantities. The flow through a normal production process is submitted to temporal changes both for random reasons, e.g. in the presence of disturbances in the same process or in a process connected serially to it, and intentionally, when the production is increased or decreased. The changes of flow may also belong to the normal operation, e.g. when the process includes devices which operate periodically like the batch digesters for cellulose pulp or when pipelines slowly get clogged under longterm use.
Because of the same changes of flow the controllers connected to the production process have to be tuned for the worst occurring case or, in practice, for the smallest occurring value of the flow. The time parameters of the process which depend on the flow are inversely related to the magnitude of the flow and, correspondingly, the bandwidth of the process, or the frequency range in which the process represents a considerable gain with regard to the input signals, is directly related to the flow. If now the controller would be tuned so that it gives an optimal result for the nominal value of the flow, and if the flow would then decrease, a narrower bandwidth of the process would result, assuming unchanged properties of the controller, whereby the control would deteriorate and the control could even fall into an oscillatory state, if the flow would become small enough. The presence of such inconvenient oscillations is known in practice i.e. in control of the temperature of a liquid by means of a tubular heat exchanger. The proportion of the time delay factor is high in such process, and this implies a negative phase shift which depends strongly on the frequency and, therefore, a tendency to oscillations.
In some cases one has tried to consider the variable flow through a compensating factor which depends on it. For example, in control of the final temperature of steam in a boiler by means of water sprayed into the steam in the middle of the superheater, the flow of the cooling water is sometimes controlled to be directly proportional to the flow of the steam. The final controlled quantity, the final temperature of the superheated steam is measured separately and the setpoint of the controller controlling said cooling water is adjusted on the basis of the measured value. Since now the speed with which the final temperature of the steam reacts to the flow of the cooling water depends strongly on the steam flow, it is seen that the described control method neglects this dependence, and the temperature controller, acting as the main controller, must be tuned for the smallest occurring steam flow.
Because of the varying flow, the continuous flow process is time variable, i.e. its parameters change with time. It has been shown theoretically that the residence time distribution of the mass flow process can be brought to an invariant form of presentation, if the continuous flow Q, which is the essential factor causing the time dependence, is taken into consideration by shifting to a new variable z (A. Niemi, Int. J. of Applied Radiation and Isotopes (1977) pp. 855-860). ##EQU1## V volume t,ν time variables
η fixed origin of time
The residence of a material in a continuous flow device can be described by means of a function of one quantity, the difference z(t,η)-z(θ,η)=z(t)-z(θ), even if the flow varies. If the functional form of the residence distribution of the process is known, and if the input quantity of the process is observed by means of measurements, the output quantity of the process can be calculated by means of this function, even if the flow varies.
SUMMARY OF THE INVENTION
The present invention provides a method for the incorporation of varying process in the control of flow quantities, which comprises measuring the passing flow, integrating the result of the measurement so as to determine the amount of material flowed through the process, determining values of a variable in direct ratio to said amount of material, and performing the control of the process synchronously with regard to said variable.
The invention is applicable in the control of processes with both known and unknown flow characteristics and takes the changes of the flow through the process into consideration. The device may typically be a proportional-plus-integral-plus-derivative controller whereby it, as compared with a conventional PID controller, implies an improvement in that it operates equally well at a variable flow as at a constant flow, while the operation of a loop provided with a conventional PID controller deteriorates, if the flow deviates from the constant value which corresponds to the conditions for which the controller was tuned.
A basis of the invention is the finding that, although the controller does not normally contain a mathematical model of the process, it nevertheless handles mathematically the control deviation, i.e. the difference of the output quantity of the process from the reference value, and that these mathematical operations can be brought into a dependence on the flow through the process. A controller of this kind can be connected to the process to be controlled in the same manner as the conventional, commercially obtainable controllers and provided additionally with measured information of the flow through the process. Like the commercial controllers, a controller of this kind can be tuned by experimentation, even if the mathematical process model would be unknown, whereby, using it, for constant flow equally good results and for variable flow better results are reached, than using a conventional controller. In order to describe the structure of the new controller and to present the tuning methods which lead to the best results, it will be shown in the following that the above described variable, which is proportional to the time integral of the flow through the process, can be used as a basis of the ways of presentation and methods of tuning which are parallel to previously known methods of control technology.
The control object is described in engineering practice and also in textbooks of control engineering expediently by a dynamic model formed of differential equations. Such dynamic process model can be composed e.g. for an ideal mixer in order to describe the concentration C of some component of the process material in dependence of the concentration C 0 of the incoming flow.
V(dC/dt)=QC.sub.0 -QC (2)
If, besides the concentrations, also the flow changes as a function of the time, Q=Q(t), one obtains by introducing the variable presented in the introduction (1):
V(dC/dz)·(dz/dt)=Q(t)C.sub.0- Q(t)C (3)
dC/dz=C.sub.0 -C (4)
Despite the variable flow, the model of the concentration process has thus been brought to a constant coefficient form of presentation. A corresponding, although more complicated, form of presentation is obtained for the system of several mixers, which for its description, requires an equal number of first order differential equations, or for a process which can be approximately presented by a model consisting of several mixers. The model consisting of several first order differential equations can be brought, further on, to the form of one differential equation of a higher order. If the Laplace transformation is applied to this equation, the transfer function of the process is obtained. From this one may, further on, go to the frequency response characteristic over the process, by a change of a variable. All methods, quantities and functions needed here are well known and much used in control engineering. They are described in detail in the literature dealing with the basics of control engineering.
In the referenced article it is presented that the residence characteristics of continuous flow vessels and also systems of other types, like those including plug flow or recycling of material, or those having a general, arbitrary mixing characteristic, can be presented using the variable z. If the functional form of the model is known analytically, like in the two cases mentioned first, one obtains by the Laplace transformation from the respective invariant weighting function the transfer function of the process and from this, further on, the frequency response characteristic. If, on the other hand, the distribution is known, e.g. on the basis of experimental results, in the form of a sequence of numbers which has been presented in an invariant form as a function of z, one may go from this to the frequency response characteristic by means of the numerical Fourier transformation; the use of the latter for transformation of an invariant function of the time is known from prior art (J. Hougen and R. Walsh, Chem. Engng Progress 57, No. 3, 1961, pp. 69-79).
The methods of tuning the controller which are based on the transfer function, on its characteristic function and on graphical ways of presenting the frequency response characteristic, which are described in textbooks of control engineering, and which aim to the control of processes with constant parameters, can now be applied. By means of them, the controller can thus also be tuned for a process submitted to variable flow, assuming that this has first been brought to an invariant form of presentation. If one wants to use e.g. a PID controller, suitable values are chosen for the three controller parameters K p , K I and K D by known graphical methods in the frequency domain. Using the transfer function presentation, the following input/output dependence and transfer function G(s) are valid for such controller:
U(s)=G(s)E(s) (5)
G(s)=K.sub.P +(K.sub.i /s)+K.sub.D s (6)
E(s) Laplace transformation of control deviation
U(s) Laplace transformation of output quantity of controller
The selection of the values of the parameters in question proceed in tuning the new method entirely the same way as in the control parameters of a time invariant process, since when operating in the frequency domain, the methods of handling are independent of the type of original presentation from which one has entered the frequency domain.
No controller connected to a real production process which executes control continuously or repeatedly does perform these control calculations in a transform domain, but in the time domain where the transfer function or frequency response characteristic of the controller are corresponded by their inverse transforms. In a manner which corresponds to the conventional inverse transformation to the time domain, one returns now by an inverse transformation from the variables of the frequency domain to the original variable z. The controller will then perform its mathematical operations in terms of this variable. ##EQU2##
Since the flow Q and, further on, the variable z are known by continuous or repeated measurements and integration, the output quantity u of the PID controller can be determined in a straightforward way. This quantity is directed to the actuator as the control signal in the same way as in using a control with constant parameters in the known manner. It is seen from the equation (1) that if the flow Q does not change but keeps continuously to its nominal value, the controller in fact performs the integration and derivation with regard to the normal time variable and thus operates as the controller of other process quantities in the fully same manner as the conventional PID controller. If one considers that in addition to the volume V also the flow Q is now constant, one sees that the coefficients K of the equation (7) can be calculated in a simple way from the corresponding coefficients of the conventional control, if these are known previously, and no other method of tuning is needed.
If the model of the process is not known or if it is known only inaccurately, the standard controllers including the PID controller are tuned in practice by experimentation. A similar experimenting method of tuning can also be applied to the selection of the parameter values of the controller presented here. The scheme of a control loop provided with the presented controller is shown in the FIGURE.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The FIGURE presents a feedback control loop of a continuous flow process in which the quantity z is formed which is directly proportional to the time integral of the flow. The controller forms the proportional control component by multiplying the control deviation with a constant, the integral control component by integrating the control deviation with regard to z, and the derivative control component by differentiating the control deviation with regard to z, and determines the control signal of the process as the sum of these components. The flow Q may alternatively be measured at the input side of the process. Y and Y ref refer to the output quantity of the process and to its desired value.
Following logically from the same principle, one may construct controllers of other types which perform the control with z as the argument, and thus apply for use also in the case of variable flow. E.g. phase lead and phase lag compensators can be presented by differential equations written in terms of z which, in addition to the input and output quantities additionally include derivatives of each with regard to z. With known methods of solving differential equations, these can be brought to a solved form which corresponds to the equation (7) without being, however, identical with it. The output quantity u(z) can be continuously determined from this equation, if the input quantity e(z) of the controller is known as a function of z. Likewise such known feedforward control algorithms (e.g. A. Niemi, Proc. of ISA Conf. (pp. 63-68) and Proc. of Joint Automatic Control Conf. (pp. 37-42), Philadelphia, Oct. 16-20, 1978, ISA, Pittsburgh), which are based on information of the model of the continuous flow process, can be determined with regard to z instead of t, when they take the variable flow into consideration.
If the process can be presented by first order differential equations, the controller can be designed in time domain by methods of optimal control. Especially for linear systems with constant coefficients and a quadratic control criterion, the textbooks present standard methods for determination of the controller, with the time variable t as the argument. These methods apply as such for use in the case of a variable flow as well, with z as the argument, for determination of the feedback control. Especially if the controller has to perform integrations or differentiations it is then beneficial to use a control method based on the variable z and perform these operations with regard to this variable instead of the time variable t. The presented control method eliminates the effects of changes of flow completely in principle, in control of concentration or of other quality characteristic of a material. If also other physical processes take place within the control object, in addition to the variation of the concentration effected by flow and mixing, the dynamical properties of the process often depend only partly on the flow. Such process and control function is e.g. the temperature of a continuous flow process and its control, while simultaneously heat losses to the environment take place. Also then the presented control method is beneficial, since while neglecting, in the same manner as the conventional controller, the effects of the changes of heat losses on the process dynamics, it anyway takes the effects of the variable flow into consideration, which the conventional controller neglects. With regard to the process dynamics, the effects of the flow are the more essential, the smaller the heat losses to the environment are. If the latter are negligible, the fully same advantages are reached with the presented control method, as in control of the concentration.
The presented method can be used beneficially also then, when some partial process is bound to the absolute time variable. This may be the case e.g. in control of concentration in such continuous flow reactor in which the progress of the reaction depends essentially on kinetic factors. In taking the effects of the flow changes into consideration the presented controller means also in this case a partial improvement with regard to the conventional controller.
The presented control method can be implemented in a straight-forward way by using as the controller a computer which may be e.g. a microcomputer. The computational operations required by the method are easy to program including the integration of the flow with regard to time and the integration and differentiation of the control deviation or of the other input quantities of the controller with regard to z. If the flow and the input quantities of the controller are expressed in analog signals, they have to be first brought into a digital form. Analog-to-digital converters are standard components aimed to this task, and likewise the transfer of digital data into a computer is a normal property of the real time computer. Likewise the conduction of the output signal of the controller into an actuator is a known operation and the digital-to-analog converter is a standard component which is used, when the control of the actuator requires an analog signal. Also other types of operations can be usefully executed in the controlling computer. Such an operation is the formation of the square root required in connection with the measurement of flow by means of an orifice element. Several components including the control unit may also be common to several control loops.
While using certain measurement devices for flow, e.g. those provided with a rotating mechanism, it may be beneficial to determine a signal which is proportional to the time integral of the flow or to the amount of material flowed through the process, at the measuring devices, separately from the controller itself. Then the determined quantity is transmitted continuously or repeatedly to the controller with which the above equipment for measurement and computation communicates and which operates in the manner presented earlier.
Mostly the space between the discrete signal elements or the sampling interval can be made considerably smaller than the dominating parameters of the process which usually requires that the z-interval is considerably smaller than 1. If this is not the case, it may be necessary to use special methods of the discrete control. They are analog to the corresponding methods of the continuous control, and the methods in question have been described in detail in textbooks on the basics of control engineering. The methods have been presented with the discretized time as the independent variable, but they are also applicable while using the above described variable which is directly proportional to the amount of material flowed through the continuous flow process, as the discretized, independent variable. The described method is thus applicable for use in the case of the discretized control in the same manner and with the same benefits as in the case of the continuous control.
The method can be alternatively implemented also with components handling analog signals. Then one must take into consideration that e.g. in electrical and pneumatic analog components the integration and differentiation take place with regard to the time variable and not with regard to z which would be required e.g. by the equation (7). By inspecting the meaning of the quantity z according to the equation (1), one sees that e.g. the derivative term present in the last member of the equation (7) can be compensated by the derivative of the control deviation with regard to time, if the member is additionally divided by the instantaneous value of the flow. Correspondingly the control deviation in the integrand of the next to the last member has to be multiplied by the instantaneous value of the flow after which the product in question is integrated with regard to time. The devices required for determination of the product of two variable quantities are known components in the technology of analog computers. The components required for integration, differentiation, addition, subtraction, and multiplication by constants are, on their part, already previously used in conventional analog controllers.
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There is disclosed a method and an apparatus for the incorporation of varying flow in the control of process quantities. According to the invention the passing flow is measured and the amount of material flowed through the process is determined by integration of the result of said measurement. Furthermore, values of a variable are determined in direct ratio to the amount of material and the control of the process is performed synchronously with regard to that variable.
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FIELD OF THE INVENTION
[0001] The present invention relates to a solar-pumped active device. More particularly, the present invention relates to an active device using a holographic antenna grating on a solar energy silicon substrate to couple the required specific pump wavelength in sun light in an approximately vertical direction to generate a laser. Or, in the active device, the spared pump wavelength propagated through the solar energy silicon substrate is diffracted into an optical gain medium again to be amplified by using a reflection layer.
DESCRIPTION OF THE RELATED ART
[0002] The erbium-doped (Er-doped) fiber amplifier (EDFA) generally excites a 10-meter Er-doped fiber with a laser of 980 nm (nanometer) wavelength to produce a light amplification gain of 20 dB (decibel) to 30 dB during 1530 nm to 1560 nm. Nevertheless, about one ampere current is constantly consumed on driving the semiconductor laser and the cooling chip for temperature control, not to mention that a pump wavelength of 1480 nm would consume more electricity. This would bottlenecks the applications of the optical communications in some special environments, such as the satellite, the mountain, the desert, the South Pole, or the North Pole, where electricity is hard to obtain. To generate electricity by solar energy is now widely welcomed and assiduously developed in many countries due to its harmlessness to the environment and resource of the earth. Similar effort has been made on converging sunlight to excite optical gain medium for producing a laser having high energy of tens of watts, which was made successful in the laboratory decades ago and is one of the subjects for the scientists to study continuously. However, large-scale focusing lens are used in most of the conventional methods to collect sufficient pump wavelength needed in sunlight for obtaining larger gain. With such a structure, solar-pumped laser or optical amplifier are only suitable in use of studies inside laboratories by few scientists. Therefore, this structure is not generally suitable for commercial products, not to mention it is a too big device to be installed on an artificial satellite or in an international space station. Yet, in order to meet the demand on the transmission of great amount of data or images in a short time for meteorological or military satellites, the satellite optical communication is one of the significant items assiduously developed nowadays by those countries with advanced technologies. The wireless optical communication is of no doubt the best choice for high speed data transmission between a satellite and another satellite or even between a satellite and a ground station. In addition, the high directionality of a laser also provides the communication with high confidentiality. And, so, the satellite optical communication is also one of the significant items being developed by the defense authorities of all countries. Therefore, in order to realize the idea of wireless optical communications for the artificial satellites, a solar power amplifier in a small size but with high convert efficiency is becoming one of the necessary and important devices.
[0003] Conventionally, a laser with high gain and high output power (up to 18 watts) can be obtained by pumping the sunlight. However, the sunlight is almost always focused by a large-scale parabolic lens or by using focusing methods of non-imaging optics, which makes the structure of the whole laboratory seem quite huge and diminish the practicability. Furthermore, because almost all of the sunlight is focused onto the optical gain medium, the optical gain medium has to be cooled down by cooling water simultaneously to prevent the lens from over-heating. As illustrated above, in the future, the main factor for whether the solar power optical amplifier and the laser would be successfully practicable lies on the use of a focusing method which is characterized in selective wavelengths and the small size of the device.
[0004] In the prior art, a holographic grating is added into the structure of the optical waveguide so that the transmission energy in the optical waveguide can be coupled in an almost vertical direction to be irradiated and to form a focusing effect like a Fresnel lens. And, according to the principle of the reversibility of the optical path, if a parallel beam is vertically impinged to the optical waveguide grating, the beam will be coupled into the optical waveguide and will be focused at the focal point, which is known as a holographic antenna grating. The maximum diffraction efficiency of such a grating for a specific wavelength is about 40 percent. And a reflection layer can be simply deposited under the grating to reflect the spared pump light to the diffraction grating for increasing its diffraction efficiency. However, the grating is only used to couple the signal light in the optical waveguide to be irradiated, or to couple external signal light to the optical waveguide to be transferred, wherein no collector of a large-facet holographic antenna grating is proposed to collect specific wavelength from sunlight for being coupled to an optical gain medium to form a laser.
[0005] Now, the holographic antenna grating is used to couple the external pump light to be transferred in an almost vertical direction into the optical waveguide which comprises an optical gain medium at the bottom; and so an optical amplifier is obtained. Therein, however, no fabrication of a large-facet coupling device for specific sunlight wavelength is proposed, neither is proposed a fabrication of a complete round-shaped holographic grating which can converge pump wavelength into the grating center to collect mass energy to excite optical gain medium for obtaining a laser and for optical amplification. Moreover, the way for obtaining the optical signal gain is by the effect of the evanescent field, whose excite effect is not as effective as the present invention owing to that the evanescent field can directly couple the pump light into a high-doped Er waveguide to obtain a strong overlapping among the signal light, the pump light and the optical gain medium.
SUMMARY OF THE INVENTION
[0006] Therefore, the main purpose of the present invention is to couple required pump wavelength in sunlight in an almost vertical direction by a holographic antenna grating, wherein the wavelength is transferred horizontally and converged at the optical gain medium to be excited by the pump wavelength for obtaining a laser.
[0007] Another purpose of the present invention is to substantially improve the vertical-oriented diffraction efficiency; and, by using a reflection layer, the spared pump wavelength propagated through the solar energy silicon substrate can be diffracted into an optical gain medium again to be amplified and so to improve the diffraction efficiency.
[0008] A further purpose of the present invention is to provide a solar energy pump light amplifier which needs no electricity and is suitable for special environments, such as the artificial satellite, the international space station, the adventure station for external celestial bodies, the international long-distance air route airplanes, the mountains, the deserts, the South Pole and the North Pole, etc. If the present invention is equipped with a backup solar cell, the present invention can be used as a signal amplification device in optical communications to save energy in usage. But, while the present invention is used on the ground, it is better to be used in the areas with dry climate, such as the continental areas or the desert areas, though the dust storm seasons are exceptions; and it is suitable to be deposited on the top of an enterprise building.
[0009] The last purpose of the present invention is to meet the demand on electricity for the optical amplifiers in the optical communications.
[0010] To achieve the above purposes, the present invention is a solar-pumped active device which comprises a solar energy silicon substrate with a holographic antenna grating, wherein an optical waveguide is at the center of the grating. By the grating, the required pump wavelength in sunlight is coupled in an almost vertical direction and then is transferred horizontally and converged at the optical gain medium to be excited by the pump wavelength for substantially improving the diffraction efficiency. An optical gain medium is at the center of the optical waveguide. A reflection layer is on the solar energy silicon substrate, by which the spared pump wavelength propagated through the solar energy silicon substrate is diffracted into an optical gain medium again for improving the total diffraction efficiency. The present invention meets the demand on electricity for the optical amplifiers in the optical communications and is suitable for special environments, such as the artificial satellite, the international space station, the adventure station for external celestial bodies, the international long-distance air route airplanes, the mountains, the deserts, the South Pole, the North Pole, etc. If a backup solar cell is equipped with the present invention in usage, it can be used as a signal amplification device in optical communications to save energy. But, while the present invention is in use on the ground, it is better to be used in the areas with dry climate, such as the continental areas or the desert areas, though the dust storm seasons are exceptions. And the present invention is suitable to be deposited on the top of an enterprise building.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be better understood from the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings, in which:
[0012] FIG. 1 is a vertical view of the operation principle of the optical amplifier according to the present invention;
[0013] FIG. 2 is a side view of the optical amplifier according to the present invention;
[0014] FIG. 3 is a cross-section view of the optical amplifier according to the present invention;
[0015] FIG. 4 is a vertical view of the operation principle of the laser according to the present invention;
[0016] FIG. 5 is a view of the serial connection of the optical amplifiers according to the present invention;
[0017] FIG. 6 is a view of the serial connection of the lasers according to the present invention;
[0018] FIG. 7 is a spectrum view showing the absorption of the erbium-doped glass according to the present invention;
[0019] FIG. 8 is a spectrum view of the 980 nm-laser diode according to the present invention, wherein ‘nm’ stands for ‘nanometer’;
[0020] FIG. 9 is a spectrum view showing the gain obtained from the erbium-doped glass waveguide impinged by a halogen light bulb with 250 W (watt) according to the present invention;
[0021] FIG. 10 is a spectrum view showing the gain obtained from the erbium-doped glass waveguide impinged by a 980 nm laser with 280 mW (milli-watt) according to the present invention;
[0022] FIG. 11 is a spectrum view showing the gain obtained from the erbium-doped glass waveguide where the sunlight is focused by a Fresnel lens of a square of 30 cm×30 cm according to the present invention, wherein ‘cm’ stands for ‘centimeter’;
[0023] FIG. 12 is a view showing the strength of the sunlight where the current of the 980 nm laser is adjusted to simulate the status of FIG. 11 according to the present invention; and
[0024] FIG. 13 is a view showing the spectrum of the solar radiation from 10 nm (nanometer) to 100,000 nm which is measured by US Naval Research Laboratory.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The following descriptions of the preferred embodiments are provided to understand the features and the structures of the present invention.
[0026] Please refer to FIG. 1 through FIG. 3 , which are a vertical view of the operation principle, a side view, and a cross-sectional view, of the optical amplifier according to the present invention. As shown in the figures, the present invention is a solar-pumped active device which comprises a solar energy silicon substrate 1 , an optical diffraction element 21 , a first optical reflection element 22 , an optical waveguide 3 , an anti-reflection film 11 , an optical gain medium 4 , an input port 61 , an output port 62 and a reflection layer 5 .
[0027] Therein, on the solar energy silicon substrate 1 are a reflection layer 5 with a waveguide layer 12 which comprises an optical diffraction element 21 ; an optical waveguide 3 ; an optical gain medium 4 ; and an anti-reflection film 11 . The required wavelength is coupled by the optical diffraction element 21 of the waveguide layer 12 and the first optical reflection element 22 of the optical waveguide 3 ; and then it is converged to the optical gain medium 4 so that the signal launched into the input port 61 is then amplified and transmitted through the output port 62 . Accordingly, an amplifier is obtained.
[0028] The solar energy silicon substrate 1 can further be a substrate covered with a silicon dioxide waveguide layer 12 having a thickness of around several optical wavelengths. An optical diffraction element 21 is on the solar energy silicon substrate 1 , which element can be a holographic antenna grating or a photonic crystal in a surface-relief type or an index-modulation type made into a large facet for collecting sufficient sunlight. An optical waveguide 3 is at the center of the present invention. An optical gain medium 4 is at the center of the optical waveguide 3 , which medium can be a highly-doped erbium (Er) glass, an ytterbium-doped (Yb-doped) glass, an Er/Yb co-doped glass, or a glass of a rare earth element. The Er-doped glass is radiation-hardened to prevent from the solarization effect. A first optical reflection element 22 is on both sides of the optical gain medium 4 , which element can be a reflection grating, a Bragg grating, or a reflection grating for pump wavelength. A reflection layer 5 and an anti-reflection film 11 are covered on the solar energy silicon substrate 1 to improve the light absorption efficiency. The required pump wavelength in sunlight is coupled in an almost vertical direction by the optical diffraction element 21 , which wavelength is transferred horizontally and then converged at the optical gain medium to be excited by the pump wavelength. The spared pump wavelength propagated through the solar energy silicon substrate 1 is diffracted into the optical gain medium 4 again by the reflection layer 5 so that the signal launched into the input port 61 is then amplified and transmitted through the output port. Accordingly, an amplifier is obtained.
[0029] Please refer to FIG. 4 , which is a vertical view of the operation principle of the laser according to the present invention. Here, the present invention at least comprises a solar energy silicon substrate 1 , an optical diffraction element 21 , a first optical reflection element 22 , a second optical reflection element 23 , an optical gain medium 4 , an output port 72 , an anti-reflection film 5 and a reflection layer 11 .
[0030] Therein, the solar energy silicon substrate 1 is covered with a reflection layer 5 and a silicon dioxide layer 12 , and on the substrate 1 are an optical diffraction element 21 , an optical gain medium 4 , and an anti-reflection film 11 . The required pump wavelength is coupled into the optical waveguide 3 by the optical diffraction element 21 and is confined to propagate along the optical waveguide 3 back and forth by the first optical reflection element 22 ; and then, it repeatedly excites the optical gain medium 4 to obtain a laser in coordination with the second optical reflection element 23 ; and then, it is transmitted through the output port 72 .
[0031] The solar energy silicon substrate 1 can further be a substrate covered with a silicon dioxide waveguide layer 12 having a thickness of about several microns. An optical diffraction element 21 is on the solar energy silicon substrate 1 , which element can be a holographic antenna grating in a surface-relief type or an index-modulation type or a photonic crystal made into a large facet for collecting sufficient sunlight. An optical waveguide 3 is at the center of the present invention. An optical gain medium 4 is at the center of the optical waveguide 3 , which medium can be a highly-doped Er glass, an Yb-doped glass, an Er/Yb co-doped glass, or a glass of a rare earth element. The Er-doped glass is radiation-hardened to prevent from solarization effect. A first optical reflection element 22 is on both sides of the optical gain medium 4 , which element can be a reflection grating, a Bragg grating, or a reflection grating for pump wavelength. A reflection layer 5 and an anti-reflection film 11 are on the solar energy silicon substrate 1 to improve light absorption efficiency. The required pump wavelength in sunlight is coupled in an almost vertical direction by the optical diffraction element 21 , which wavelength is transferred horizontally and then is converged at the optical gain medium 4 to be excited by the pump wavelength. The spared pump wavelength propagated through the silicon dioxide waveguide layer 12 is diffracted into the optical gain medium 4 again by the reflection layer 5 . And, by coordinating with the second optical reflection element 23 on both sides of the optical gain medium 4 , a laser is obtained and is outputted by the output port 72 . The second optical reflection element 23 can be a reflection grating for lasing wavelength.
[0032] Therein, the optical diffraction element 21 can further be substituted with a photonic crystal to achieve the effect of the present invention. The vertical diffraction efficiency of the photonic crystal is higher so that the holographic antenna grating of the present invention can be substituted with a photonic crystal; yet, the reflection grating for pump wavelength and the reflection grating for lasing wavelength are reflecting the specific wavelength by the photonic band gap of the photonic crystal, wherein the operation is not the same as the reflection done by the photonic crystal that substitutes the holographic antenna grating.
[0033] And, further by the characteristic of the dispersion of the optical gain medium 4 and the different characteristics of the silicon dioxide layer near by, the present invention can obtain a laser or an amplifier for S band or another band of light. If the optical gain medium 4 is Er-doped or Er/Yb-doped and the optical gain medium 4 is boron-doped and the holographic silicon dioxide grating layer is fluorine-doped, a laser and an amplifier for S band of light can be made according to the characteristic of the dispersion of the material or according to the characteristic of the higher material dispersion slope of the optical gain medium 4 than that of the silicon dioxide layer 12 , no matter what material is doped into the optical gain medium 4 or the silicon dioxide layer 12 . Accordingly, a laser and an amplifier for C band of light with shorter wavelength are obtained. Besides, if the optical gain medium 4 is Er-doped or Er/Yb-doped, it can be further doped with aluminum; and, if doped with a rare earth element, further boron-doped or germanium-doped. And, the silicon dioxide can further be substituted by a polymer. Because no electricity is in need in the present invention, the substrate 1 of the present invention can be made of another metal or a polymer or a dielectric material. The shape of the holographic antenna grating is not limited to be a circle; it can further be an ellipse or any other geometric shape. The host material for the optical gain medium 4 can be a phosphate glass, a fluorophosphates glass, a silicate glass, or a borate glass.
[0034] The present invention can be applied in many environments, such as the optical communications between satellites, the optical fiber communications, the wireless optical communications, etc., and can solve the problem of the electricity needed by the optical amplifier in the optical communications nowadays, wherein a solar-pumped optical amplifier required no electricity is obtained that can be used in special environments, such as the artificial satellites, the international space stations, the adventuring stations of external celestial bodies, the international long-distance air route airplanes, the mountains, the deserts, the South Pole and the North Pole. If the present invention is equipped with a backup solar cell in usage, it can be used as a signal amplification device in the optical communications to saves energy. But, while the present invention is used on the ground, it is better to be used in areas of dry climate, such as the continental areas or the desert areas, wherein dust storm seasons are exceptions; and it is suitable to be deposited on the top of an enterprise building. In short, the present invention is suitable for all applications of solar energy silicon substrate 1 (solar energy cells).
[0035] The holographic antenna grating which is capable of selecting wavelength can couple the almost vertically impinged pump wavelength in the spectrum of sunlight to become a pump wavelength propagating in a horizontal direction. The benefit is that, by using the waveguide layer 12 on the solar energy silicon substrate 1 , the 980 nm (nanometer) or 1480 nm pump wavelength in sunlight can be coupled vertically into the waveguide layer 11 . And then the pump wavelength is converged to the center of the holographic antenna grating 21 to enter into the Er-doped glass of the optical waveguide 3 , so that the erbium ions are excited by a pump wavelength power to obtain the effect of optical amplification. By further coordinating with a reflection grating for lasing wavelength, a laser can be obtained. Therein, only the wavelength in the holographic antenna grating 2 which is diffracted around 980 nm or 1480 nm enters into the optical waveguide 3 ; and, the main light absorption band (550 nm to 750 nm) of the solar energy silicon substrate 1 (solar energy cell) for generating electricity will not be affected. Therefore, the advantage of the present invention is that the optical communication can be achieved by simply applying a waveguide layer 11 on the solar energy silicon substrate 1 which formerly has a large facet and by fabricating a holographic antenna grating 2 of large facet thereon, while there is no influence on generating electricity by the solar energy silicon substrate 1 (solar energy cell). However, a critical defect of the holographic antenna grating 2 is that, theoretically, its maximum diffraction efficiency is only 40 percent. In another word, only 40 percent of 980 nm wavelength in sunlight can be coupled and be transferred horizontally to enter into the optical waveguide 3 at the center, and the other 60 percent of wavelength will propagate to the solar energy silicon substrate 1 (solar energy cell) at the bottom. According to the experimental results of the present invention, the diffraction efficiency is estimated to be around 30 percent, but it can still form a pump energy greater than 200 mW (milli-watt) on a square-shaped diffraction plate with a facet of 30 cm×30 cm. Concerning the diffraction efficiency, by simply adding a 980 nm refection layer 5 under the holographic antenna grating 2 , The spared pump wavelength propagate through the silicon dioxide waveguide layer 12 can be reflected back to the holographic antenna grating 2 , followed by transferring to the waveguide layer 12 and propagating into the optical gain medium 4 to obtain an amplifier. Thereby, the diffraction efficiency of the holographic antenna grating 2 can be improved indirectly.
[0036] Please refer to FIG. 5 , which is a view of a serial connection of the optical amplifiers according to the present invention. Therein, an amplifier can be obtained by serializing the amplifiers as connecting the output of a solar-pumped active device with the input of another solar-pumped active device.
[0037] Please refer to FIG. 6 , which is a view of a serial connection of the laser according to the present invention. Therein, a laser can be obtained by serializing the lasers as connecting the output of a solar-pumped active device with the input of another solar-pumped active device for achieving the effect of.
[0038] Please refer to FIG. 7 and FIG. 8 , which are spectrum views showing the absorption of the Er-doped glass and the 980 nm laser diode according to the present invention. As shown in the figures, a spectrum of solar radiation measured by US Naval Research Laboratory is used to obtain a simple estimation:
[0039] 1. According to FIG. 13 , measured by US Naval Research Laboratory, the total power of sunlight on the ground in one square meter is 1366 W/m 2 , while ‘W’ stands for ‘watt’ and ‘m’ stands for ‘meter’; the energy around exact 980 nm is 887.5 mW/nmZm 2 . The pump wavelength of the sunlight that can excite the optical gain medium 4 is only the wavelength of from 970 nm to 980 nm. (As shown in FIG. 7 .) In fact, the wavelength of from 965 nm to 985 nm can be coupled into the waveguide layer 12 in an approximately vertical direction. On considering the above situations, the effective energy of pump wavelength obtained from the sunlight is 887.5 mW/nmZm 2 ×(985−975)=8875 mW/m 2 =8875×10−4 mW/cm 2 .
[0040] 2. By using a square-shaped holographic antenna grating 2 with a facet of 30 cm×30 cm, the total power of the pump wavelength absorbed from the sunlight is 8875×10−4 mW/cm 2 ×30 cm×30 cm=789.75 mW.
[0041] 3. According to the theory of the holographic antenna grating 2 , the maximum diffraction rate is 40%. If the diffraction rate obtained is around 30%, the total power of the pump wavelength received is 789.75 mW×0.3=236.925 mW. In another word, by using a holographic antenna grating 2 with a facet of 30 cm×30 cm, more than 200 mW of 980 nm pump power is obtained, which is the power around exact 980 nm. In addition, the facet of the solar energy cell plate on the satellite has a size of several square meters. Therefore, the practicability of the present invention is for sure.
[0042] The power for the commercial 980 nm pump laser is usually expressed with the measurement obtained by an integrating sphere and a power-meter. Therefore, generally, a 980 nm laser with 200 mW does not mean that there is really a power of 200 mW existed around 980 nm; rather, it means an integral of all the spectrum energy. But now, by using a 280 mW of high efficiency 980 nm pump laser, the measurement obtained by the power-meter is really almost 280 mW. However, by using a spectrum analyzer, much power outside of 980 nm can be found. (As shown in FIG. 8 .) Therefore, the method used in the present invention for measuring the power of pump wavelength from sunlight is much severer than that which is generally used.
[0043] Please refer to FIG. 9 and FIG. 10 , which are spectrum views showing the spectra of Amplified Spontaneous Emission (ASE) obtained from the erbium-doped glass waveguide impinged by a 250 W (watt) halogen bulb and by a 980 nm laser with 280 mW, according to the present invention. As shown in the figures, the following is a comparison between the methods of exciting the optical gain medium 4 (i.e. Er-doped glass) on its side with a 250 W halogen bulb (as shown in FIG. 9 ) and with a 280 mW of 980 nm pump laser (as shown in FIG. 10 ):
[0044] 4. By exciting a highly Er-doped glass of a dimension of 20 mm (millimeter) in length and 17 mm in width and 5 mm in height with a 250 W halogen bulb, a spectrum of an ASE from the optical Er-doped fiber amplifier is obtained, as shown in FIG. 9 .
[0045] 5. By using a 280 mW of 980 nm pump laser, a spectrum of an ASE from the optical Er-doped fiber amplifier is obtained, as shown in FIG. 10 .
[0046] Comparing FIG. 9 with FIG. 10 , the 1.53 mm (micrometer) wavelength power can reach the similar level in both figures. In another word, the capacity of a 250 W halogen bulb for exciting the optical gain medium 4 (i.e. Er-doped glass) on its side is similar to that of a 980 nm semiconductor laser of 280 mW. And, the ASE power of the Er-doped amplifier seems very weak. One of the reason is that the ASE power of the optical Er-doped fiber amplifier outputted from the optical gain medium 4 (i.e. Er-doped glass) is not focused into the spectrum analyzer. And, another reason is that the pump wavelength can not fully excite such a big optical gain medium 4 (i.e. Er-doped glass). Yet the comparative result will not be influenced under such a condition. The gain of 1.53 mm wavelength in FIG. 9 seems smaller than that of FIG. 10 , which is caused by that more white light is directed in by the halogen bulb to enter into the spectrum analyzer and so the noise level becomes higher. Here, the only concern is on how much power can be generated by the ASE of the Er-doped fiber amplifier, which is related to the pumping ability of the light. If the other wavelengths from the halogen bulb are filtered off, the gain obtained in FIG. 9 can be as much as that in the FIG. 10 . In the other hand, the solar energy for one square meter can be assumed as about 1.36 kW (kilowatt). Even though the diffraction efficiency of the holographic antenna grating 2 is only around 30%, a total power of about 450 W can still be obtained, wherein the power is still more than that which is generated by the 250 W halogen bulb. Therefore, by using a holographic diffraction plate with a facet of 50 cm×50 cm only, efficiency like that of a 980 nm pump laser of 280 mW can be achieved successfully.
[0047] Please refer to FIG. 11 and FIG. 12 , which are a spectrum view showing the ASE obtained from the optical gain medium where the sunlight is focused to a Fresnel lens of a square of 30 cm×30 cm and a view showing the strength of the sunlight simulating FIG. 11 by adjusting the current of the 980 nm laser, according to the present invention.
[0048] The following is the comparison made between the results of exciting the optical gain medium 4 (i.e. Er-doped glass) by focusing the sunlight and by a 980 nm pump laser of 100 mW:
[0049] 6. At noon in a sunny day, in a temperature of 30 Celsius degrees, by using a holographic Fresnel-lens focusing plate of acrylic material with a facet of 30 cm′30 cm, the sunlight is focused onto the optical gain medium 4 (i.e. Er-doped glass) on its side. By using the spectrum analyzer to measure the amplification effect of the optical gain medium 4 , the optical ASE spectrum is obtained as illustrated in FIG. 11 , wherein the stimulated emission and the spontaneous emission are measured directly without using the focusing lens. The power of 1.54 mm wavelength can reach about −40 dBm, wherein the attenuation around 1.4 mm is caused by the absorption of the band gap of the acrylic material.
[0050] 7. Concerning the 980 nm pump laser under a 206 milliampere current, the power is measured as 100 mW by a power-meter. Under the same experimental conditions, by using the power to excite on the sides, the optical gain medium 4 (i.e. Er-doped glass) is excited to obtain ASE spectrum as illustrated in FIG. 12 , wherein the ASE power obtained at 1.53 mm is about −42 dBm.
[0051] By comparing FIG. 11 with FIG. 12 , it can be found that the capacity of a Fresnel zone plate with a facet of 30 cm′30 cm for exciting a optical gain medium 4 (i.e. Er-doped glass) is no smaller than that of a 980 nm pump laser of 100 mW. In addition, when the sunlight is focused onto the optical gain medium 4 (i.e. Er-doped glass), because the light beam is wider than the optical gain medium 4 (i.e. Er-doped glass), not all of the energy is propagated into it. In the other hand, the 980 nm pump laser is propagated through the fiber so that a strong power can be focused and propagated in a smaller area to obtaining a higher excited state population inversion in optical gain medium 4 (i.e. Er-doped glass).
[0052] Therefore, by way of focusing the sunlight, the efficiency of the exciting by a high-power 980 nm pump laser can be easily achieved. Therefore, if the solar optical amplifier is widely used, it would carry out a great technique revolution in the field of the optical communications, especially in satellite optical communications and ground wireless optical communications.
[0053] The preferred embodiments herein disclosed are not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.
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The present invention provides a solar-pumped active device which utilizes a holographic antenna grating on a solar energy silicon substrate to select specific diffracted wavelength and couple pump wavelength in an approximately vertical way and converge the pump wavelength to excite an optical gain medium so that an optical amplifier or a laser can be obtained. The present invention requires no big size and is flexible over the surface shape and is suitable for free space optical communications on the ground and satellite optical communications. It means that the holographic antenna grating can be applied on the top floor of a building or on the glass surface of an outer wall. If it is applied to a satellite, the present invention can be deposited on a solar energy cell substrate to form a high optical amplification so that not only the electricity required in satellite optical communications can be reduced, but also a high-speed and large capacity of data can be transferred between satellites.
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BACKGROUND OF THE INVENTION
This invention relates generally to improvements in centrifuges for cleaning liquids.
In more particular aspects this invention relates to oil cleaners of centrifuge type, in which a drum, into which the oil is fed, is mounted in bearings for rotation within a housing and is rotated about a vertical axis by the reaction of oil jets from nozzles rotating with the drum.
In still more particular aspects this invention relates to centrifugal filter separators, based on the principle of Hero's engine, in which the solid contaminants in the oil collect on the inner surface of the rotating drum, together with water, which is removed from the rotating drum through the extraction mechanism located on the drum shaft.
In still more particular aspects this invention relates to the water extraction mechanism, of a centrifugal filter based on the principle of Hero's engine, which is removable from the shaft of the drum, permitting cleaning of the internal surfaces of the drum of accumulated solid contaminants.
Centrifugal oil filters, using a rotating drum powered by reaction of oil jets, are well known in the art. In such filters the incoming oil is subjected to very high centrifugal forces, resulting in separation of solid contaminants and water. During operation of the filter the water can be removed from the space, adjacent to the inner surface of the drum, by the water conducting tubes, communicating with the hollow shaft. The solid contaminants are centrifuged to the inner surface of the drum and form a layer of thick paste, which from time to time must be removed by opening the drum and cleaning the inner surface. During this cleaning operation the centrifuged water conducting tubes interfere with the removal of the contaminants, which must be scraped from the inner surface of the drum. During those periodic cleaning operations the centrifuged water conducting tubes may be easily damaged or bent, resulting in mass inbalance of the rotating drum assembly, which in turn may generate large out-of-balance forces and severe vibrations of the filter. Also the accurate placement of the centrifuged water conducting tubes, in respect to the inner surface of the drum, is very difficult.
SUMMARY OF THE INVENTION
It is therefore a principle object of this invention to provide a centrifuged water extraction device, which is easily removable from the shaft of the drum, to facilitate the cleaning of the inner surface of the drum.
Another object of this invention is to provide a centrifuged water extraction device axially slidable in respect to the shaft of the drum, but restrained from angular displacement in respect to the shaft of the drum.
It is another object of this invention to provide a centrifuged water extraction device, mounted on the shaft of the drum and provided with radially extending water conducting tubes.
It is a further object of this invention to provide a centrifuged water extraction device having a sleeve, mounted on the shaft of the drum and radially extending water conducting tubes slidably engaging the sleeve, while being restrained from radial displacement by the inner surface of the drum.
It is a further object of this invention to provide a centrifuged water extraction device having a sleeve mounted on the shaft of the drum and radially extending water conducting tubes, with one end slidably engaging the sleeve, while the other slotted end is restrained from radial displacement by the inner surface of the drum.
Briefly the foregoing and other additional advantages of this invention are accomplished by providing a novel centrifuged water extraction device for use in a drum of a centrifugal filter, the drive of which is based on the principle of Hero's engine, which is easily detachable from the shaft of the drum, to facilitate the removal of the layer of solid contaminants from the inner surface of the drum.
Additional objects of this invention will become apparent when referring to the preferred embodiments of the invention as shown in the accompanying drawings and described in the following detailed description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an embodiment of a centrifugal filter separator with one of the jet nozzles shown in external view and the sectioned water conducting tube angularly displaced by 45°.
FIG. 2 is a sectional view along line 2--2 of FIG. 1 showing bottom view of the drum and location of its jet nozzles.
FIG. 3 is a sectional view along line 3--3 of FIG. 1 with oil conducting tubes removed.
FIG. 4 is a sectional view along line 4--4 of FIG. 1 showing details of the water conducting tubes assembly.
FIG. 5 is a partial sectional view of the top of an oil conducting tube with strainer in place.
FIG. 6 is a top view of the spring support of FIG. 3.
FIG. 7 is a slide view of the spring support of FIG. 6.
FIG. 8 is a fragmentary section of another embodiment of a water conducting tube.
FIG. 9 is an installation drawing of the centrifugal filter separator of this invention, mounted on a reservoir and supplied with oil under pressure from a pump.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a centrifugal filter separator assembly, generally designated as 10 and shown in partial section along the vertical axis, comprises a base 11 and a cover 12 forming together a housing, generally designated as 13, which mounts on a vertical axis a drum assembly, generally designated as 14. The base 11 is provided with inlet 15, conducting oil under pressure to a lower internal bearing 16 and an oil outlet 17. The cover 12 is provided with an upper internal bearing 18, secured in place by plate 19, mounting centrifuged water extraction valve 20. A reaction washer 21 with passage 22 is retained between the upper internal bearing 18 and the plate 19. A breather assembly 23 is mounted on the upper surface of the cover 12. The drum assembly 14 includes a lower cup 24 and an upper cup 25, secured together, in sealing engagement, by a shaft assembly, generally designated as 26. The lower cup 24 is provided with two reaction jet nozzles 27 and 28, shown also in FIG. 2. The shaft assembly 26 is provided with a shaft 29, a retainer 30, a key 31, a driving pin 32, a water extraction device assembly, generally designated as 33, a washer 34 and a nut 35. The shaft 29 is provided with a lower external bearing 36, inlet oil passages 37 and 38, collecting groove 39, seal grooves 40 and 41, water passage 42 and an upper external bearing 43, terminating in a sealing surface 44. Inlet tubes 45 and 46, provided with strainers 47 and 48, are connecting, for oil flow, the interior of the drum 14 with the reaction jet nozzles 27 and 28 and are radially spaced by a flat spring 49, which is part of the water extraction device assembly 33. The water extraction device 33, slidably engages by its sleeve 50 the shaft 29 and is constrained from rotation in respect to the shaft 29 by a driving pin 32, working in a slot 51. The water extraction device 33 is provided with centrifuged water extraction tubes 52, which connect through open ends and low slots 53, the space adjacent to an inner surface 54 of the drum 14 with water passage 42. The sleeve 50 is equipped with two driving slots 55 and 56, engaging projections in the flat spring 49 and a reaction member 57, which are located in respect to the sleeve 50 by a retaining ring 58.
Referring now to FIG. 2 the reaction jet nozzle 28, shown in section, is provided with jet orifice 59.
Referring now to FIG. 3 the flat spring 49 is provided with openings 60 and 61, guiding inlet tubes 46 and 45.
Referring now to FIG. 4 four extraction tubes 52 are shown in their true position, in respect to inlet tubes 45 and 46.
Referring now to FIG. 5 the inlet tube 45, with its tube end 62, is shown engaging the opening 61 of the flat spring 49 and guiding the strainer 47.
Referring now to FIG. 6 the reaction member 57 is shown provided with projections 63 and 64, engaging driving slots 55 and 56.
Referring now to FIG. 7 the reaction member 57 is shown with its curved section 65.
Referring now to FIG. 8 an extraction tube 66 is shown in contact with the inner surface 54 of the lower cup 24, while slidably engaging a surface 67 in the sleeve 50, mounted on the shaft 29.
Referring now to FIG. 9 the filter separator assembly 10 is shown mounted on a reservoir 68 and connected by line 69 with a pump 70, driven by a motor 71. A relief valve 72, in a well known manner, limits the oil pressure supplied to the filter separator. A line 73 supplies a hydraulic circuit, not shown, with clean oil.
Referring now back to FIG. 1, oil under pressure is supplied from the pump 70, of FIG. 9, to the inlet 15 of the filter separator 10 and reacting on the cross-sectional area of the lower external bearing 36 lifts the drum 14 upwards to a point, at which the sealing surface 44, of the upper external bearing 43, comes in contact with the reaction washer 21. Since the cross-sectional area of the upper external bearing 43 is made smaller than the cross-sectional area of the lower external bearing 36, the drum 14 will be maintained in this position, as long as the inlet 15 is supplied with pressurized oil. Oil under pressure is transmitted from the inlet 15 through the inlet oil passage 37 to the internal space of the drum 14. Once the internal space of the drum 14 is pressurized the oil under pressure is transmitted through strainers 47 and 48 and inlet tubes 45 and 46 to the reaction jet nozzles 27 and 28. In a well known manner, a jet of oil will be ejected through the jet orifice 59 of FIG. 2, of reaction jet nozzles 27 and 28, providing a reaction torque, which will rotate the barrel 14 around its vertical axis. Under those conditions the speed of rotation of the drum 14 may exceed, say 5000 revolutions per minute, subjecting the oil contained in the drum 14 to centrifugal accelerations in excess of 2000g. In a well known manner, the solid dirt particles in the oil, together with the heavy liquids like water, will be centrifuged to the inner surface 54 of the drum 14, while the clean oil, conducted through the inlet tubes 45 and 46, will be ejected by the reaction jet nozzles 27 and 28 to the space enclosed by the housing 13, which is connected, by the outlet 17, with the system reservoir 68, shown in FIG. 9. The total assembly of the drum 14, subjected to very high speeds of rotation, must be very well balanced, or the filter separator assembly may be subjected to very severe vibrations. Since the sealing surface 44 is maintained at all times against the reaction washer 21, the liquid under pressure in the water passage 42 is effectively isolated from the space enclosed by the housing 13, while it is transmitted through passage 22 to the water extraction valve 20.
As previously stated the solid contaminants and the water are centrifuged from the oil, introduced into the drum 14 and are maintained by the centrifugal forces against the internal surface 54. The solid contaminants form a layer of thick paste on the surface 54, which may attain a thickness of over one half of an inch, while the centrifuged water forms another layer, maintained by centrifugal force on top of the layer of the solid contaminants. Periodically the cover 12 is removed and also the nut 34 is removed, lower and upper cups 24 and 25 are separated and the layer of solid contaminants scraped from the surface 54.
The centrifuged water can be extracted from the rotating drum 14 during operation of the filter separator 10. The shaft 29 mounts the drum assembly 14 in lower and upper bearings, maintains together the lower and upper cups 24 and 25 and slidably engages the water extraction device assembly 33. The water extraction device 33 is provided with the sleeve 50, slidable along the vertical axis of the shaft 29, but prevented from rotation in respect to the shaft 29 by the slot 57, engaging the driving pin 32. The sleeve 50, with four extraction tubes 52, connects, through the collecting groove 39, the space adjacent to the internal surface 54 of the drum 14, with the water passage 42 and the water extraction valve 20. The flat spring 49 is deflected by the curved section 65, of the reaction member 57, which is prevented from rotation, in respect to the sleeve 50, by projections 63 and 64, engaging driving slots 55 and 56 and maintained in position by the retaining ring 58. The flat spring 49 is provided with similar projections and keyed to the sleeve 50, see FIGS. 1, 3, 6 and 7. The deflected flat spring 49 transmits a downward force to the inlet tubes 45 and 46, while locating them radially, in respect to the sleeve 50 and the shaft 29, see FIG. 5, while also transmitting an upward reaction force to the sleeve 50, maintaining it against the upper cup 25. In a well known manner, the sleeve 50 can be located by a retaining ring in respect to the shaft 29. Then the upward reaction force of the flat spring 49 will be directly transmitted to the shaft 29, maintaining together the inlet tube assemblies.
A small amount of water, together with some solid contaminants, is lost through leakage at the sealing surface 44, maintaining the internal surface 54, in the vicinity of the slotted ends of the extraction tubes 52, relatively clear of the solid contaminants and with free access to the layer of centrifuged water. By opening the passage through the water extraction valve 20, due to the existing pressure differential, all of the centrifuged water can be drawn from the rotating drum 14.
As shown in FIG. 1, the slotted ends of the extraction tubes 52 are spaced from the inner surface 54 and retained in the sleeve 50. Rotational balancing of the water extraction device 33 of FIG. 1, because of its construction and configuration, is difficult, see FIG. 4. The mounting of the extraction tubes 66 of FIG. 8 in respect to the sleeve 50 and in respect to the inner surface 54 provides great advantages. Identical extraction tubes 66 are placed in sliding engagement on the surface 67 of the sleeve 50 and are permitted, under action of centrifugal force, to engage with their slotted ends the surface 54, ensuring an identical spacing from the center of rotation and therefore identical balance. The slots 53 provide then a free passage for extraction of the centrifuged water.
While removing by scraping the layer of solid contaminants from the surface 54 of the lower cup 24, the extraction tubes 52 are in the way and can be easily damaged or bent. To prevent this the water extraction device 33, of the present invention, can be removed from the shaft 29, together with the inlet tubes 45 and 46, permitting, during the cleaning operation, free access to the inner surface 54 of the lower cup 24. Once the water extraction device 33 is removed from the shaft 29, the individual extraction tubes 66 can also be removed for cleaning from the sleeve 50.
The centrifuged water extraction tubes 52 of FIG. 1 or 66 of FIG. 8 can be located above the partition plane between cups 24 and 25 and within the space enclosed by the cup 25. Then, once the cup 25 is removed for cleaning, the centrifuged water extraction tubes 66 can be radially removed from the surface 67, providing free access for cleaning of the lower cup 24.
Although the preferred embodiments of this invention have been shown and described in detail it is recognized that the invention is not limited to the precise form and structure shown and various modifications and rearrangements as will occur to those skilled in the art upon full comprehension of this invention may be resorted to without departing from the scope of the invention as defined in the claims.
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A centrifugal filter separator operable to separate from oil under pressure solid contaminants by depositing them on the internal wall of a rotating drum, powered by reaction jet nozzles and to separate water from oil and extract it from the rotating drum. The rotating drum is composed of two cups held together by a shaft, passing through the axis of rotation of the drum and mounting a water extraction mechanism, which can be removed from the shaft during cleaning of the internal wall of the drum of the deposited solid contaminants.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a window comprising an interior glazing and an exterior glazing between which air circulates, the interior glazing being heated.
2. Description of the Related Art
The glazed walls of a building, i.e., the windows, are often considered to be components which allow, in winter, the escape of heat since their heat loss factor K is higher than that of the other walls. These glazed walls are thus cold walls, which brings about the consequence of a certain discomfort for persons in the vicinity of the glazed walls. Consequently, the floor spaces of the offices or accommodations located in the vicinity of the glazings are little used, hence a loss of the space that can actually be used.
Traditional means currently used to reduce such heat loss include the use of insulating glazings for the glazed parts and of thermally isolated sections for their frames. But these techniques have their limits and an altogether different technique has been proposed, i.e., the application of a "parietodynamic" insulation system to the glazed walls. In this system, fresh air taken from outside the room circulates on the inside of the glazed wall before being introduced in the room, which limits losses since this air enters the room after having been preheated by its passage within the wall.
However, it has been desired to improve this system further by combining it with a heating means. Accordingly it has been proposed, in particular in EP patent application No. 165,287, to equip such a glazed wall with means for providing air circulations past a heated glazing and in a direction toward the interior of the room. The cold wall effect has thus been corrected and it has even been possible to eliminate other equipment for heating the room. This is the case for U.S. Pat. No. 4,641,466 and French patent document No. 88.14009 which propose improving the energy efficiency of the system by limiting radiative heat exchange between the heated glazing and the outer glazed wall.
French patent application FR No. 2 611 029 shows a double or triple wooden window system which incorporates the various preceding functions. A frame and sash system designed especially for this type of application is also there described. While being well suited to the technical problem to be solved, this type of window is necessarily very costly since the solutions considered are complicated and require sash sections of large cross section, using considerable amounts of material. Further, these windows and therefore the sections that constitute them are specialized and usable exclusively for this particular and relatively limited use. Production runs are therefore short and the cost is consequently high.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system that makes it possible to transform traditional windows into heated windows with parietodynamic insulation.
To do this, the invention proposes equipping a traditional window with a heated interior second glazing. The heating is advantageously provided by a resistor that is located on the transparent surface of the second glazing.
In a variant, a conductive transparent layer constitutes the heating resistor, for example a layer of semiconductive metal oxide. Further, the latter is advantageously in contact with the air space.
The parietodynamic effect can be obtained according to the invention by providing the top and bottom crosspieces of the sashes with openings which make it possible for outside air to enter at the low part into the air circulation space and to be expelled at the high part toward the interior of the room. The partial vacuum in the interior of the room is produced by independent systems.
A characteristic of the invention also provides that when the second glazing is open, the electric power supply for its heating is automatically cut off.
The layers that heat the second glazing are one or more of the layers belonging either to the group of the layers pyrolyzed from powders and comprising the layers of tin oxide doped with fluorine and the layers of indium oxide doped with tin, or to the group of the layers obtained by vacuum cathode sputtering of a conductive metal between transparent dielectric layers.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a plastic window according to the invention in vertical cross section;
FIG. 2 shows a heated glazing;
FIG. 3 shows another window consisting of plastic sections, also in vertical cross section; and
FIG. 4, the same window as in FIG. 3, in horizontal cross section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a polyvinyl chloride (PVC) window according to the invention. It is composed of a window frame made of sections 1 fastened in the opening of the wall (not shown) by conventional fastening techniques. Thiswindow frame is equipped with elastomer seals 2 on which window sash 3 rests. The latter is composed of substantially identical sections on its four sides. It has, over its entire periphery, elastomer seals 4 which rest on the periphery of the window frame.
In a conventional way, the window sash is equipped with a glazing 5 installed on shims 6. It is held in place between elastomer seals 7 mounted to the sash and to a cover 8 which fits in housings of the sash.
The windows thus constituted are conventional windows.
The present invention is added to this conventional window and comprises three features which are, successively: the installation of an interior second glazing, the parietodynamic circulation of air, and the equipping of the second glazing as a heated glazing.
The second glazing structure is shown in FIG. 1. It consists of a frame section 9 that is metal or preferably of insulating material. This sectionframes a glazing 10 by means of an elastomer section 11. The frame section constitutes a frame that is welded, glued, or mechanically assembled at the corners thereof. It is airtightly mounted on cover 8, by elastomeric seals 12. Hinges (not shown in the figure) make is possible for the frame to pivot around a vertical axis. Likewise, on the vertical side opposite the one which supports the hinges, a standard latching system is installed. The pairing of the hinges and of the latches makes it possible to exert a pressure on the elastomer seals 12 and to assure a good airtightness between the window sash and the frame of the second glazing.
The circulation of air in the air circulation space between the two glazings 5 and 10 necessitates an intake duct, an exit duct and a difference in pressure between the outside and the inside of the room. Theducts are made by drilling and milling apertures through the sections of the window sash. This operation requires particular care since the cross section of the apertures must be sufficient in view of the volume of the room, the desired flow rate of fresh air (for example, a half room volume per hour) the number of windows according to the invention that the room has and the pressure loss in each of them, to allow the appropriate air renewal.
The position of the drillings through the various walls of the sections should enable the latter to keep their mechanical characteristics. In FIG.1, the apertures have been shown only in the top and bottom crosspieces of the sash, at 13 for the passage from the outside into the sash section, atlower aperture 14 for the introduction into the air circulation space, at 15 for the exit from this space toward the sash section, at 16 for the horizontal crosspiece of the latter and at 17 for the return toward the interior of the room. In the Figure, all these apertures are shown in the same vertical plane. In reality, only lower aperture 14 must have a precise position and shape; it is a slot which occupies most of the width of the double glazing. At the upper part of the sash, the positioning of aperture 15 need be less exact because the hot air accmulates in this zoneregardless of where this opening exits. Also, outside air apertures 13, horizontal crosspiece 16 and apertures 17 for the interior can, in contrast with what is shown in FIG. 1, be located anywhere on the surface of the sash frame, optionally on the uprights. The main criterion is that they have sufficient cross sections to provide adequate air flow while maintaining the mechanical strength for the sections.
To make the air circulate, it is obviously necessary that a pressure gradient exists between the outside and interior of the room. It is possible, as in U.S. Pat. No. 4,641,466 of FR No. 2 611 029, to incorporate the device which creates the internal vacuum in the window unit, but it is also possible and in general less expensive to use the existing controlled mechanical ventilation system for the building (or room). For this purpose, the total cross section of the aperture at each of the different levels for all the windows must have an area greater thanthe effective cross section of the ventilation system. The implementation of these apertures does not require any specialized technique, it could even--in the case of equipping existing windows--be performed on site after removal of the sashes.
The last element of the system proposed by the invention is the heated window (glazing) element itself; it is installed at 10 in the frame 9.
FIG. 2 shows in detail an example of a heated window element. A heat-tempered soda lime silica glass is seen at 10. It is covered with a conductive transparent layer 18 obtained for example by the process described in EP No. 125 153, i.e., a layer of tin oxide doped with fluorine with a surface resistance of, for example, 50 ohms per square meter.
On the layer 18, parallel to the large or small sides of the rectangle consisting of the glazing, are formed power lead-in strips 19 consisted ofa conductive enamel, for example, with a silver base deposited by silk screen printing before tempering.
In a standard way, electric conductors, not shown, are soldered to these power lead-ins 19. The glazing of FIG. 2 is stripped of layer 18 at 20, along its edges. This makes the problems of electrical insulation easier, but this is not essential. It is possible to have the layer over the entire surface of the glazing, the nature of the peripheral seal (11, FIG.1) and the care in mounting then guaranteeing a good electrical insulation.
Instead of the heated glazing of FIG. 2, any other type of glazing equippedwith resistors on its surface can be used. It is possible, for example by silk screen printing of a silver paste, to have discrete conductors on thesurface of a glass or, in another example, to use a transparent continuous layer of silver deposited by cathode sputtering and integrated into a laminated glazing whose interlayer is of polyvinyl butyral.
The electric power supply of the heated glazing is of a standard type. Generally, the electrical resistance of each heat glazing element is the same because, for reasons of cost, the glazing layer is produced in large quantities and generally by unit elements of large surface, after which the unit elements are cut, the power lead-in strips are formed and finallythe glazing is tempered. It is not then possible to adjust the resistance of each element: such resistance is determined by the initial surface resistance and by the dimensions of the element. But on the other hand, itis necessary to be able to adapt the maximum electrical power capacity of the heated glazing to the current needs. This is especially true if the windows according to the invention constitute the only heating system for the room. It is then necessary that for the most intense cold, the input of heat is adequate and provides comfort to the occupants of the room. Therefore varying the value of the electric supply voltage will make is possible to assure this necessary nominal power.
But under these conditions, it is possible that the supply voltage will be higher than that with which the human body can come in contact without danger. Accordingly, in this case, the second glazing, if its conductive surface is accessable, will have to be equipped with safety systems which automatically cut off the power supply as soon as the opening of the double glazing occurs. This system, for example has been proposed in French FR No. 2 180 433.
The double glazing, further, is equipped with standard regulating systems that make it possible to adjust its temperature to instantaneous needs.
FIG. 3 illustrates a vertical cross section of another type of window, alsoof PVC. Window frame 21 is fastened in the opening of the wall, not shown, and sash 22 rests by elastomer seal 23 on the window frame. The second glazing 9, 10 is identical with that of FIG. 1. Seen also in the Figure are the air intakes in the low part of the sash and the successive exit apertures that make it possible for air to exit from the space between theglazings after having circulated in the wall. Arrow 24 symbolically represents the passage of cold air at the low part, and arrow 25 the exit of warmer air at the high part.
As was the case in FIG. 1, the apertures made in the sash sections for the passage of air are all shown in the same vertical plane but actually, except for the fourth low aperture (in the order of passage of air) which must occupy the entire width of the double glazing, and except for the first high aperture which advantageously will occupy at least half the width (preferably on the outside edges), the position of the apertures is of little importance provided that their cross sections, considering the pressure losses, are sufficient (The preceding description, valid for plastic or aluminum sections obviously does not apply to wooden windows orwindows with a frame of solid plastic or foam. In this case, it would require a continuity of the drillings so as to constitute a duct).
In FIG. 4, there has been shown sash section 22 of a window identical with the one of FIG. 3 but along a horizontal cross section which makes it possible to see how second glazings 9, 10 can be fastened to sash sections22, in particular the hinge 26 and the latch 27 are seen.
Application of the window according to the invention can be performed in one of three different ways depending on whether it is a new construction,the reconditioning of a window or the adaptation of a window already installed. In the three cases, preliminary studies will have determined, depending on the type of window and the nature of its material, e.g., (wood, aluminum, PVC, etc.), the best suited way to make the drillings of the air intakes and exits. These will be made on the sashes on which the installation of the second glazings will also be made, the connections will be prepared both on the sashes--generally in the workshop--and in theroom itself, on site, and in connection with the window frame. The sash-window frame connection being performed at the last moment.
The advantages of the system according to the invention are practical and economical. On the practical level, building skills are very traditional and installation techniques in one region are very different from those inanother. The commercial preparation necessary for the introduction on the market of a completely new product is long and expensive. According, a system where one can add new functions (improvement of insulation, air renewal and heating) to an existing window system is very advantageous compared with the launching of a completely new multifunction system.
The economic advantages have already been mentioned; here the simplest possible components are used and both the window and the second glazing profit from the costs of mass production since they are both sold independently, and each in its own market: i.e., the market for new or reconditioned windows versus the market for double glazings.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention maybe practiced otherwise than as specifically described herein.
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A window of a double glazing system includes a window frame formed in a wall of a room, a sash fitted in the window frame and an outer glazing mounted in the sash, all of which are conventional. A second glazing is mounted to the sash and at an interior position relative to the outer glazing, so as to form an air circulation space between the second and outer glazings. The second glazing is heated by a transparent electrical resistance layer formed thereon and apertures are formed in the sash to create an air circulation path from the outside, through the air circulation space into the room. As a result, fresh air circulating into the room is heated by the heated second glazing.
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BACKGROUND
The invention generally relates to etching metal using sonication.
In a variety of different circumstances, it may be desirable to selectively etch metal in the formation of a semiconductor device. For example, the etching of metal may be related to the formation of a metal silicide layer (a nickel silicide layer, for example), a layer used to reduce metal-to-semiconductor contact resistances in a semiconductor device.
To form a metal silicide layer, a metal layer (nickel, for example) typically is deposited on a semiconductor structure. In this manner, the deposited metal reacts with exposed silicon of the structure to form the metal silicide layer. Not all of the deposited metal layer typically reacts. In this manner, the regions in which the metal layer does not react form excess or un-reacted metal regions that typically are removed by wet etching. As a more specific example, FIG. 1 depicts a semiconductor structure 9 that represents a particular stage in a process to form a complimentary metal oxide semiconductor (CMOS) transistor. For this example it is assumed that the CMOS transistor is formed on a silicon substrate 12 . As shown in FIG. 1, the polysilicon layer 18 resides on top of a gate oxide layer 16 , and vertically extending nitride spacers 20 may be located on either side of the polysilicon layer 18 .
For purposes of creating a nickel silicide layer, a nickel layer 22 may be blanket deposited over existing layers of the structure 9 . As depicted in FIG. 1, the deposited nickel layer 22 extends over portions of the silicon substrate 12 as well as extends over a polysilicon layer 18 . The regions in which the nickel layer 22 contacts the silicon substrate 12 form parts of the source and drain of the transistor, and the region in which the nickel layer 22 contacts the polysilicon layer forms part of the gate of the transistor in this example.
Thus, the deposited nickel layer 22 contacts the polysilicon layer 18 and the silicon substrate 12 , and in these contacted regions, the nickel layer 22 reacts with the polysilicon layer 18 and the silicon substrate 12 to form the nickel silicide layer that extends into regions 26 of a resulting structure 10 that is depicted in FIG. 2 . As a more specific example, a particular nickel silicide region 26 a may be associated with a drain of the transistor, another nickel silicide region 26 b may be associated with a source of the transistor, and another nickel silicide region 26 c may be associated with a gate of the transistor.
The deposited nickel does not react everywhere, leaving regions 24 of excess or unreacted nickel. To remove these regions 24 , selective wet etching is used to target the nickel but not other substances (such as nickel silicide, for example) to remove the nickel to form a structure 11 that is depicted in FIG. 3 . Thus, after the selective wet etching, the unreacted nickel portions 24 (see FIG. 2) are removed, leaving only the regions 26 of nickel silicide film, as depicted in FIG. 3 .
The wet etching typically involves submersing a wafer that contains the structure 10 into a nickel selective etchant, or etching fluid, that typically includes both an acid, such as sulfuric acid, and an oxidant, such as hydrogen peroxide or nitric acid. At room temperature, the use of sulfuric acid by itself to etch the nickel is not sufficient due to the potential energy barrier that prevents the oxidation of the nickel in accordance with the Pourbaix chart for nickel. Therefore, an oxidant typically is introduced into the etching fluid to supply the needed energy to oxidize the nickel into an aqueous derivative and thus, dissolve the nickel.
For certain semiconductor devices, an oxidant in the etching fluid may undesirably oxidize and thus, etch substances that are not meant to be etched. For example, elemental germanium substrates, germanium-doped silicon substrates and germanide films are examples of germanium-based substances that typically are highly susceptible to oxidants that are used in the etching of nickel. The etch rates for these germanium substances may be the same or even higher than the etch rate for nickel in the presence of such an oxidant. Therefore, when germanium-based substances are present, the use of conventional etching fluid to etch nickel may undesirably dissolve significant portions of these germanium-based substances.
Thus, there is a continuing need for a better way to selectively etch metal that is disposed on a semiconductor structure that contains certain semiconductor substrates, films and/or layers.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1, 2 and 3 are cross-sectional views of semiconductor structures depicting different stages in the formation of a semiconductor device according to the prior art.
FIG. 4 is a flow diagram depicting a technique to form a semiconductor structure according to an embodiment of the invention.
FIGS. 5, 6 , 7 and 8 are cross-sectional views of semiconductor structures in accordance with embodiments of the invention depicting different stages in the formation of a semiconductor device.
DETAILED DESCRIPTION
Germanium-based substances (herein called “germanium substances”), such as germanide films, germanium-doped regions and elemental germanium substrates, may be highly susceptible to the etchant, or etching fluid, that is conventionally used to etch nickel. In this manner, a typical etching fluid for nickel contains an acid, such as sulfuric acid, and an oxidant, such as hydrogen peroxide or nitric acid, which are highly oxidizing in nature. Although this etching fluid may be used in a standard silicon-based process, the etching fluid undesirably etches germanium substances because germanium is highly soluble in a low pH, aqueous solution that contains an oxidant (hydrogen peroxide or nitric acid, as examples).
Thus, if such an oxidant-containing etching fluid is used to etch nickel that is disposed on a semiconductor structure that includes germanium substances, the germanium substances maybe undesirably dissolved. However, an etching fluid that lacks an oxidant is not by itself sufficient to etch nickel due to the potential energy barrier that exists for dissolving nickel (i.e., oxidizing nickel to some aqueous nickel derivative) in a low pH solution. To address this problem, an embodiment of a technique in accordance with the invention overcomes the potential energy barrier by applying sonic energy to an oxidant-free etching fluid. Thus, with the application of sonic energy to oxidant-free etching fluid during etching of nickel, the nickel may be selectively etched while germanium substance(s) of the semiconductor structure remain intact.
Therefore, referring to FIG. 4, an embodiment 100 of a technique in accordance with the invention includes depositing (block 102 ) a metal layer on a semiconductor structure. This metal layer may be, for example, a nickel layer, that reacts with germanium regions of the structure to form a nickel germanide film, or layer. This nickel germanide layer, in turn, may be located between germanium substances of the structure and source and drain metal contacts for purposes of reducing contact resistances between the germanium substances and these contacts. The nickel layer may also be deposited for purposes of forming a nickel silicide layer between a polysilicon layer and a gate metal contact for purposes of reducing a contact resistance between the polysilicon layer and the gate metal contact.
After the metal layer to form the germanide layer (and possibly a silicide layer) is deposited in accordance with the technique 100 , the resulting metal germanide and silicide regions are annealed, as depicted in block 104 . Subsequently, in accordance with the technique 100 , the structure is selectively wet etched with an oxidant-free etchant, or etching fluid, to remove the excess or unreacted metal regions (unreacted or excess nickel regions, for example) while sonic energy is applied to the etching fluid to supply sufficient energy to facilitate oxidation of the metal being etched, as depicted in block 106 . The etching fluid may include sulfuric acid, for example. Due to the lack of an oxidant in the etching fluid, undesirable etching of germanium substances of the structure does not occur.
As a more specific example, FIGS. 5, 6 , 7 and 8 depict semiconductor structures that represent different stages in the formation of a CMOS transistor, in accordance with some embodiments of the invention. More specifically, FIG. 5 depicts a semiconductor structure 118 , in accordance with an embodiment of the invention, that is formed on a germanium substrate 122 . The substrate 122 may be an elemental germanium substrate. Alternatively, the substrate 122 may be a silicon substrate that is doped with germanium in the source and drain regions of the transistor.
Regardless of how the germanium is introduced, the germanium substrate 122 includes a first region 125 that may be associated with a source of the transistor and another region 127 that may be associated with a drain of the transistor. The germanium substrate 122 is isolated on either side by insulating oxide regions 124 .
The germanium substrate 122 may also include a region 129 that is associated with a gate of the transistor. A gate oxide layer 134 is deposited directly on the germanium substrate 122 on the gate region 129 , and a polysilicon layer 128 is formed on top of the gate oxide layer 134 . Nitride spacers 126 may extend upwardly on either side of the polysilicon layer 128 . Alternatively, the polysilicon layer 128 may be replaced by a germanium-based, germaniun-silicon-based or metal-based layer, as just a few examples.
As depicted in FIG. 5, a layer 130 of nickel is blanket deposited on the structure 118 and covers the otherwise exposed germanium substrate 122 and the otherwise exposed polysilicon layer 128 . Reactions occur with the nickel to form a structure 119 that is depicted in FIG. 6 .
Referring to FIG. 6, in this manner, the nickel reacts with the exposed polysilicon 128 and the exposed germanium substrate 122 to form nickel germanide regions 142 over the exposed germanium substrate 122 and a nickel silicide region 140 over the exposed polysilicon layer 128 . Thus, the nickel silicide region 140 is formed from the reaction of silicon (in the polysilicon layer 128 ) with the nickel, and the nickel germanide regions 142 are formed by the reaction of germanium (in the germanium substrate 122 ) with the nickel. Therefore, the reactions with the deposited nickel layer 130 form one nickel germanide region 142 a that is associated with the drain of the transistor, another nickel germanide region 142 b that is associated with source of the transistor and the nickel silicide region 140 that is associated with the gate of the transistor.
As illustrated in FIG. 6, not all of the nickel reacts, thereby leaving unreacted or excess nickel regions, such as the depicted regions 146 . A next step in the process to form the transistor may be the annealing of the nickel silicide region 140 and the nickel germanide regions 142 a and 142 b . After the annealing, the structure 119 is selectively wet etched in an oxidant-free etchant, or etching fluid, such as sulfuric acid, for example. During this etching, sonic energy (in lieu of the inclusion of an oxidant in the etching fluid) is applied to the etching fluid for purposes of overcoming the high energy barrier that is associated with the dissolution of nickel in solutions of low pH.
As a more specific example, in some embodiments of the invention, ultrasonic sonic energy in the frequency range between approximately 10 kilohertz (kHz) and 100 kHz may be applied to the etching fluid during the etching of the unreacted nickel. Alternatively, in some embodiments of the invention, megasonic energy in the range of approximately 500 to 1000 kHz may be applied to the etching fluid during the etching of the nickel. The sonic energy may be applied via transducers that are located in, on or near an immersion tank in which the structure 119 is immersed and the wet etching is performed.
The result of the etching is a structure 120 that is depicted in FIG. 7 . In this manner, the etching removes the unreacted nickel regions 146 (FIG. 6) to leave the nickel silicide region 140 located above the polisilicon layer 128 and the nickel germanide regions 142 a and 142 b of the drain and source regions, respectively.
Many other steps may be performed in the process to form the transistor from the structure 120 . As an example of one out of possibly many more steps that may be performed, in some embodiments of the invention, an oxide layer 160 may be subsequently deposited on the structure 120 to form a structure 121 that is depicted in FIG. 8 . The oxide layer 160 is polished back and then selective etching is performed to create contact holes so that a metal layer may be deposited to form corresponding transistor contacts 162 with the germanide and silicide films. For example, as depicted in FIG. 8, the structure 121 may include a source metal contact 162 a that extends through a contact hole in the oxide layer 160 to the nickel germanide region 142 b , and the structure 121 may include a drain metal contact 162 b that extends through another contact hole in the oxide layer 160 to contact the nickel germanide region 142 a . A gate metal contact may be also formed to the nickel silicide region 140 , although such a contact is not depicted in the cross-section illustrated in FIG. 8 .
Thus, due to the intervening nickel germanide and silicide layers, contact resistances are decreased between upper metal layers and the germanium substrate 122 and polysilicon layer 128 . As an example, tungsten may be used to form the metal contacts 162 . Other metals may be used.
In the context of this application, although the preceding description may have used such terms as “over” and “on” to describe the relative positions or locations of certain substances, materials or layers these terms do not necessarily mean that the substances, materials or layers contact each other, unless otherwise stated.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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A technique in accordance with the invention includes obtaining a semiconductor structure that has a metal disposed thereon. At least a portion of the metal is etched using an etching fluid while sonic energy is applied to the etching fluid.
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FIELD OF THE INVENTION
This invention relates to a computer implementation of algorithms and methods for collecting and ranking ideas, people, or any other items. This invention further relates to use of a survey-like mechanism to obtain a prioritized or ranked list of items. The mechanism may be implemented using a network, such as the Internet.
BACKGROUND
Many entities, including those that conduct business over the Internet, find it beneficial to conduct surveys to determine what products should be offered, what services should be made available, what content should be present on a website, and so forth. Such surveys may be presented to a user after a transaction, such as the purchase of a product. Alternatively, the survey may be presented to a user independent of any particular transaction. Existing survey systems use a variety of delivery mechanisms including email invitations, banner adds, popup windows, and links on websites. The layout and presentation of the survey questions may be customized by the author of the survey to the extent allowable by the electronic survey system.
Typical survey systems allow the survey participant to respond via email, website, web application, web applet, or a client specifically designed to accept, transmit, or store the responses. The responses may take on a variety of forms including, but not limited to, single choice, multiple choice, rating scale, and text responses. Electronic survey systems typically gather the responses in a database or other electronic storage mechanism. The response data often becomes the subject matter for various reports, graphs, charts, and analysis. The reporting analysis tools are often separate from the actual survey systems themselves.
Various survey systems are presently available that allow electronic surveys to be authored and transmitted over the Internet. The existing systems use a variety of participation models. Some of the systems use an invitation-based system, in which an invitation is sent to the participant via email or other form of electronic message. The email invitations may or may not contain information to identify the person invited to the survey. Some systems use an open model that allows any visitor to a website to follow a link and respond to an electronic survey without ever identifying himself. There is also a self-registration model, where the participants identify themselves during a registration process before taking the survey.
There are several challenges associated with the use of surveys to gather information. It has been established that response rates to surveys typically decline as the amount of time required to respond increases. If the survey is too long or time-consuming, the user may not complete the survey. At the same time, the number of respondents is often a critical factor in the accuracy of a survey. The survey may not be effective if too few questions are asked of the user. Further, the questions and answer choices are predetermined by the author prior to the survey being made available for participants to respond. Thus, additional ideas of the user may not be captured.
Various efforts have been made to address these challenges. For example, to minimize the number of questions asked, some presently available electronic survey systems enable the author of the survey to specify the presentation order and skip certain survey questions based on the answers to previous questions. But even in such systems, the author of the survey writes all of the questions and answer choices.
Another way to reduce the length of the survey is to show the participant only a subset of the entire list of possible questions. There is one known company who offers the ability to show a participant a subset of the entire list. Informative, Inc. (Brisbane, Calif.) offers a product that allows a participant to select a subset of items from a larger list (that is a subset of all available items), and then arrange the subset into order according to the participant's preference.
Such systems are based on the premise that items that are receiving high rankings from respondents should be presented more often than items that are receiving low rankings. These systems consider a data collection effort to be either mature or immature, depending on the number of responses. This maturity status applies to the entire set of items. When the data collection effort is in the immature state, the items are presented to the respondents at random. When a sufficient number of responses is collected and the data collection is considered mature, the selection process shifts to selecting items with higher rankings to present to subsequent respondents. While this may be appropriate in some instances, it is limited in applicability and does not consider some other important factors that can be used to select a sample.
Some electronic survey systems have attempted to gather new items from a population of participants by enabling the participant to enter a text answer. However, to enable rapid processing of the survey results, such questions are typically limited in number, which places an artificial limitation on the number of items any one participant can submit. Furthermore, the items that are input are often deposited in a database with little information about the importance of the items.
Thus, there remains a need for a process for ranking items, people, or any other items in a manner that encourages participation and achieves high response rates. There further remains a need for a system that is able to collect items from the user and incorporate such items such that the new items are available for ranking by other participants.
SUMMARY OF THE INVENTION
The present invention generally relates to a computer based system for estimating the preference of a list of items as perceived by a population of participants, even though each participant rates only a subset of the entire list of items available for presentation. Since complete data will not likely be available, and the participants who do respond will most likely not completely agree on which items are most important, the present invention uses statistical computations to use the data that is available to most accurately estimate the order of preference that best fits the entire population. The amount of data and the quality of the data actually collected determines how accurate the estimated order actually reflects the order of preference for the population.
The system of the present invention increases the number of participant responses by decreasing the amount of time required for each respondent to express his preferences. To do so, only a subset of the complete list of items is presented to each participant, so that each participant is more likely participate and provide data. By increasing participation, the data is less likely to be biased toward the preferences of a few of the participants.
The system of the present invention is focused in particular on selecting the subset of items to be presented to each person of the population. The items are selected in a manner that improves the confidence in the estimated order of preference of the entire set of items.
According to one aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items, the stored information including display information about each of the plurality of items for presentation to a survey participant and presentation number information corresponding to the number of times a particular item has been previously shown to survey participants, selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm that utilizes the presentation number information to influence the selection of items for the subset, presenting the display information corresponding to the selected subset of items is presented to the survey participant via a survey user interface, and receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented.
In accordance with this first aspect, the method may further include the step of utilizing the rating information input by the survey participant to affect the probability of selection of the items in the selected subset in a subsequent selection of a subset of items for presentation to a subsequent survey participant using the predetermined selection algorithm.
In further accordance with this first aspect, the predetermined selection algorithm utilizes an adjustment factor to cause items to be selected more or less often as a function of the rating information obtained by previous participants of a survey. Further still, the predetermined selection algorithm utilizes, at least in part, a random number selection of items in the plurality of items.
The plurality of items may include a predetermined duplication of items in a set of the plurality of items, with the number of duplications of particular items influenced by the rating information.
In further accordance with this first aspect, the predetermined selection algorithm is self-adjusting based on previous responses received during a previous survey of the plurality of items. The self-adjusting may be based on modifying the probability of selecting an item from the plurality of items, the modifying in turn based collection of new items input by survey participants and rating of new items in comparison of previously included items.
In further accordance with this first aspect, the predetermined selection algorithm is operative initially to randomly select items for the subset of items, and thereafter operative to select items based on utilization of the rating information. The probability of selection of a given item may be continuously adjusted as items are rated by survey participants.
In accordance with a second aspect of the invention, the present invention is another method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant and frequency information corresponding to the number of times a particular item has been previously shown to survey participants. The method further includes the step of selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm that utilizes the frequency information. The method further includes the step of presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface. The method further includes the step of receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented. The method further includes the step of utilizing the rating information input by the survey participant to affect the probability of selection of the items in the selected subset in a subsequent selection of a subset of items for presentation to a subsequent survey participant using the predetermined selection algorithm.
In accordance with this second aspect, the rating information is selected from the group comprising: ranking of items relative to each other, ranking of the items on a scale, grading the items, ordering of the items, allocating points among items, scaling the items, choosing an item over other items, categorizing items, and other equivalent methods of indicating a preference of one item over another.
In further accordance with this second aspect, the step of selecting a subset of items in accordance with the predetermined selection algorithm comprises selecting based on a ranking of items using rating information from previous participants, such that the probability of selection of particular items for presenting in a subsequent survey is influenced by the rating information. In this manner, certain items that have been rated lower than other items are more likely to be selected for a survey so as to increase the number of presentations of such items.
In further accordance with this second aspect, the method comprises the step of providing the rating information for each item as an output of the method indicative of survey results.
In the foregoing and most aspects of the invention, the memory is a random access memory array. Information regarding the plurality of items is stored in an ordered array, for example in the memory, and selected according to a probability index. The information about each item in the ordered array is stored in a data field in the ordered array.
In further accordance with the second aspect, the subset of items selected for presentation to the survey participant is an initial subset, and the subsequent selection of a set of items for presentation comprises a selection from the plurality of items that may include one or more of the items from the initial subset.
In further accordance with the second aspect, the information regarding the plurality of items includes a unique identifier for each item for use as a primary key to access the item in the memory.
In further accordance with the second aspect, the method further comprises the step of storing a users item table for storing information provided by a survey participant relating to an additional item for inclusion in the plurality of items.
In accordance with various aspects of the invention, not limited to the first or second, the information regarding the plurality of items includes status information about each item. The status information is indicative whether an item has been previously shown to a survey participant or not. The predetermined selection algorithm also utilizes the status information in conjunction with the frequency information. The frequency information may be stored in a times-shown field for each item in the array.
In further accordance with the second aspect, the predetermined selection algorithm utilizes a selection score in selecting items for presentation. The selection score is based upon a confidence score. The selection score is further based on an adjusted mean rating determined from the rating information. The selection score is further based on a rank influence factor. The rank influence factor is an arbitrary number used to adjust the probability of an item being selected based on ranking information. The ranking information comprises information corresponding to the actual ranking of an item in relation to other items in the plurality of items.
In further accordance with the second aspect, the selection algorithm selects an item from the plurality of items based on a computation of a probability index. The probability index is determined based on a normalized selection score. The normalized selection score is utilized to determine a probability of selection for each item in the plurality of items, the probability of selection of each item is used to determine how many times an item is represented in the plurality of items for selection.
In further accordance with various aspects of the invention, not limited to the first or second aspect, the plurality of items are represented in a computer system as a pool of selectable items stored in an array of items, with each item in the pool having a high index number and a low index number, with the index numbers representing how many times an item is represented in the pool of selectable items, and wherein the step of selecting a subset of items comprises selecting from the pool of items based on a random number used to index into the array of index numbers. The subset of items for presenting to a survey participant is selected by repeating the step of selecting utilizing the random number, until a predetermined number of items corresponding to the size of the selected subset of items has been chosen for presentation.
In further accordance with various aspects of the invention, not limited to the first or second, a selected subset of items comprises a unique sample of items in the plurality of items of a predetermined sample size that meets predetermined selection criteria according to status information associated with the item. The predetermined sample size comprises the maximum number of items presented to a survey participant in the survey. The status information comprises information indicative of a condition associated with an item. The status information may be selected according to various criteria, for example, whether an item is scheduled, whether an item has been approved, whether an item is implemented, whether an item is active, whether an item is in or under review, whether an item has been submitted, whether an item has been declined, or other equivalent information indicative of a condition of an item.
In further accordance with various aspects of the invention, not limited to the first or second, the selected subset of items is selected for presentation based at least in part on an indication of interest of a participant. The indication of interest of a participant is obtained by input of interest information by a survey participant in response to a query prior to selection of the subset. The indication of interest of a participant is obtained by examining items previously submitted by the survey participant, and by selecting other items from the plurality of items based on the topical similarity of other items in the plurality of items. The indication of interest of a participant may be obtained by executing a query of keywords relating to items submitted by the survey participant.
In further accordance with various aspects of the invention, not limited to the first or second, the selected subset of items for presentation is a first selected subset of a predetermined small number of items, where “small” is relative but determined based on a number that is deemed by a survey manager to be acceptable for purposes of a particular survey, and further comprising the step of selecting additional items for presentation to a survey participant. The step of selecting additional items for presentation to a survey participant is based on information provided by a survey participant indicating a desire to view and rate more items. The survey participant is provided with a display offering an opportunity to request an additional sample of items for rating, and wherein the information provided by the survey participant indicating a desire to view and rate more items is input by the survey user interface. The opportunity to request an additional sample of items for rating is typically providing during a survey session.
According to a third aspect, the present invention is a method for conducting a computer-implemented survey of a plurality of items. The invention of this aspect comprises a number of steps that include arranging the plurality of items in a memory in ordered array, providing a unique identifier for each item in the array; providing information about each item in the array for presentation to a survey participant, providing a status information field for each item in the array, providing a times-shown field for each item in the array, selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm that utilizes the information in the times-shown field of the items, presenting information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to the subset of items presented, and utilizing the rating information input by the survey participant to affect the probability of selection of the items in the selected subset of times for a subsequent selection of a set of items for presentation to a subsequent survey participant using the predetermined selection algorithm.
According to a fourth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants. The invention of this aspect comprises a number of steps that include receiving rating information input by a particular subset of a plurality of survey participants via a survey user interface indicating the survey participants' preferences as to items in a presented subset of items of the plurality of items, computing the mean of the rating information, computing the standard error of the mean of the rating information, determining a confidence score utilizing the standard error of the rating information, and utilizing the confidence score to select a different subset of the plurality of items for presentation to a different subset of the plurality of survey participants. In this manner, items that might benefit from additional ratings by additional participants are selected for presentation in a subsequent survey.
According to a fifth aspect, the present invention is a method for dynamically selecting a subset of items from a plurality of items for presentation to a survey participant in a computer-implemented survey relating to the plurality of items. The invention of this aspect comprises a number of steps that include storing rating information input by a plurality of prior survey participants indicating such prior survey participants' preferences as to items in one or more subsets of items presented to such survey participants in a prior survey, determining the number of participants that have previously rated particular items in the plurality of items, determining a measure of agreement by the determined number of participants on the stored rating information of the particular previously rated items in the plurality of items, utilizing the measure of agreement on the ratings of such previously rated particular items to adjust the probability of selection of such previously rated particular items for a subsequent selection, and selecting a subset of items for presentation to the survey participant as a function of the adjusted probability of selection.
In accordance with this and various other aspects of the invention, the measure of agreement comprises the standard deviation of the mean ratings provided by the prior survey participants, or alternatively comprises the average of the mean ratings provided by the prior survey participants.
In accordance with this and various other aspects of the invention, the step of continuously changing the items in the selected subset of items based on a determined measure of agreement on the stored rating information on previously rated items.
According to a sixth aspect, the present invention is a method for dynamically selecting a subset of items from a plurality of items for presentation to a survey participant in a computer-implemented survey relating to the plurality of items. The invention of this aspect comprises a number of steps that include storing rating information input by a plurality of prior survey participants indicating such prior survey participants' preferences as to items in one or more subsets of items presented to such survey participants in a prior survey, determining the number of participants that have previously rated particular items in the plurality of items, determining a measure of agreement by the determined number of participants on the stored rating information of the particular previously rated items in the plurality of items, continuously adjusting the probability of selection of such previously rated particular items for a subsequent selection based on the determined measure of agreement on the stored rating information on previously rated items, and selecting a subset of items for presentation to the survey participant as a function of the adjusted probability of selection.
According to this and various other aspects of the invention, the measure of agreement comprises the standard deviation of the mean ratings provided by the prior survey participants, or the average of the mean ratings provided by the prior survey participants.
This sixth and other aspects of the invention may also include the step of continuously changing the items in the selected subset of items based on the determined measure of agreement on the stored rating information on previously rated items.
According to a seventh aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants in a manner that survey participants can contribute new items. The invention of this aspect includes a number of steps including storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant, selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented, receiving information input by the survey participant corresponding to an additional item for inclusion in the plurality of items, and selecting a second subset of items from the plurality of items that now includes the additional item for presenting to a subsequent survey participant in accordance with the predetermined selection algorithm.
According to this seventh and various other aspects of the invention, the method may further include the step of utilizing the rating information input by the survey participant to affect the probability of selection of the items in a subsequent selection of a subset of items for presentation to a subsequent survey participant. The information input by the survey participant is provided via an additional item submission user interface.
According to an eighth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, with an adjustment factor applied to the probability of selection. The invention of this aspect comprises a number of steps including storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant, conducting a selection operation involving selecting a subset of items for presenting to a survey participant in accordance with a function that utilizes a probability of selection, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented, determining an adjustment factor for the probability of selection of items in the subset of items as a function of the number of times that the items have already been selected and presented to previous survey participants; and applying the adjustment factor to the probability of selection for a subsequent selection operation.
According to a ninth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, wherein the selection of items is influenced by an adjustment factor derived from previous ratings. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items, the stored information including display information about each of the plurality of items for presentation to a survey participant, conducting a selection operation involving selecting a subset of items for presenting to a survey participant in accordance with a function that utilizes a probability of selection, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented, determining an adjustment factor for the probability of selection of items in the subset of items as a function of the rating information on items that have already been selected and presented to previous survey participants; and applying the adjustment factor to the probability of selection for a subsequent selection operation.
According to a tenth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, having a transitional selection process. The invention of this aspect comprises a number of steps including storing information regarding the plurality of items, the stored information including display information about each of the plurality of items for presentation to a survey participant, conducting a selection operation involving selecting a subset of items for presenting to a survey participant in accordance with a function that utilizes a probability of selection, the selection operation initially operative to select a subset of items on random basis, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented; determining an adjustment factor for the probability of selection of items in the subset of items as a function of the rating information on items that have already been selected and presented to previous survey participants and on the number of survey participants that have rated particular items, and applying the adjustment factor to the probability of selection for a subsequent selection operation. In this manner, the probability of each item being selected is continuously adjusted to be less random and more biased toward selection of unrated items and/or infrequently viewed items as items are rated by survey participants and rating information on particular items is collected.
According to an eleventh aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, involving defined criteria or predefined attributes for selection of items. The invention of this aspect includes a number of steps including storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant and predefined attribute information relating to predetermined attributes of each of the plurality of items, conducting a selection operation involving selecting a subset of items for presenting to a survey participant in accordance with a function that utilizes the predefined attribute information, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, and receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented.
In accordance with this aspect of the invention, the selection operation is further a function of probability of selection of the plurality of items as well as the attribute information. The method may further include steps of determining an adjustment factor for the probability of selection of items in the subset of items as a function of the rating information on items that have already been selected and presented to previous survey participants and on the number of survey participants that have rated particular items, and applying the adjustment factor to the probability of selection for a subsequent selection operation. In this manner, the probability of each item being selected is continuously adjusted to be less random and more biased toward selection of unrated items and/or infrequently viewed items as items are rated by survey participants and rating information on particular items is collected. The attribute information may comprises one or more of the following: a category, originator, priority, purpose, or other types of criteria or attributes.
According to a twelfth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, wherein an indication of participant willingness is utilized. The invention of this aspect comprises a number of steps that include (a) storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant; (b) conducting a selection operation involving selecting a subset of items for presenting to a survey participant in accordance with a predetermined function; (c) presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface; (d) receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented; (e) receiving an indication input by a survey participant of willingness to view and rate additional items; and (f) in response to receipt of the indication input by a survey participant of willingness to view and rate additional items, conducting a subsequent selection operation (b) and repeating the steps (c) through (f).
According to a thirteenth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, wherein a determination that more rating data is needed is made and utilized. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant, conducting a selection operation comprising selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented, determining that particular item in the plurality of items should be presented more frequently so as to obtain additional rating data; and adjusting a parameter of the predetermined selection algorithm so as to increase the likelihood that the particular item will be selected during a subsequent selection operation for a subsequent survey.
According to this and various other aspects of the invention, the step of adjusting a parameter of the selection algorithm comprise computing a confidence score among two or more items in the plurality of items, comparing the confidence scores, and using the results of the comparison to adjust the probability of selection of a particular item for which additional data is needed. The parameter of the selection algorithm may be adjusted as a function of the number of survey participants that have previously rated the particular item. The parameter of the selection algorithm may be adjusted as a function of the ratings of the particular item by survey participants that have previously rated the particular item.
According to a fourteenth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, wherein a determination that more data is needed for newer items is made and utilized. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant, conducting a selection operation comprising selecting a subset of items for presenting to a survey participant in accordance with a predetermined selection algorithm, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented, determining that a particular item in the plurality of items is relatively newer item than other items in the plurality of items, and adjusting the predetermined selection algorithm so as to increase the likelihood that the relatively newer item will be selected during a subsequent selection operation for a subsequent survey. In this manner, a relatively newer item will be presented more frequently so as to obtain additional survey data for such newer item.
According to this and various other aspects of the invention, the method may further include a step of receiving new item information input by a survey participant corresponding to the submission of a new item for inclusion in the plurality of items for the survey, such that the new item is the relatively newer item. The relatively newer item may be determined according to the time of inclusion of the item in the plurality of items, compared with other items. The relatively newer item may also be determined according to the number of times that the item has been presented in prior surveys. The relatively newer item may also be determined according to the frequency that the item has been presented in prior surveys. It will be appreciated that the “frequency” an item is presented is not the same thing as the number of times an item is presented, for example, a frequency of presentation could be “this item should be presented in 3 out of every 10 surveys,” while the number of times presented could merely be an absolute number.
According to a fifteenth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants, with random selection of items biased by the need for more data. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items in a memory, the stored information including display information about each of the plurality of items for presentation to a survey participant and frequency information indicating a number of times that items in the plurality of items have been presented in a survey, biasing the plurality of items as a function of the frequency information in anticipation of a selection operation, conducting a probabilistic selection operation comprising a random selection within the plurality of items to select a subset of items for presenting to a survey participant, presenting the display information corresponding to the selected subset of items to the survey participant via a survey user interface, and receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented. In this manner, a biased random selection of items to be presented is conducted so as to avoid presenting only newer, less frequently presented items to later survey participants and to ensure presentation of some early ideas to such later survey participants.
According to a sixteenth aspect, the present invention is a method for conducting a computer-implemented survey relating to a plurality of items from a plurality of survey participants so as to favor selection of items with a higher mean rating. The invention of this aspect comprises a number of steps that include storing information regarding the plurality of items, the stored information including display information about each of the plurality of items for presentation to a survey participant, determining a mean rating of items previously presented to survey participants, biasing the plurality of items as a function of the mean rating of items from the mean rating determining step in anticipation of a selection operation, conducting a selection operation involving selecting a subset of items from the plurality of items for presenting to a survey participant in accordance with a predetermined function that utilizes a probability of selection, presenting the display information corresponding to the selected subset of items to a survey participant via a survey user interface, and receiving rating information input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the subset of items presented. In this manner, a biased random selection of items to be presented is conducted so as to favor selection of items with a higher mean rating.
In accordance with this aspect of the invention in particular, but may also be applicable to other aspects, the biasing step involves application of a rank influence factor (rif) that may be adjusted to increase or decrease the probability of an item being selected based on the ranking of one item in relation to another item.
The computations and selection algorithms provided by the present invention are not dependent on the manner in which the data is presented to the participant. The participant may be asked to express his preference about the items presented using a variety of user interface concepts including rating each item independently, arranging several items in order of preference, or allocating a fixed number of points among the items presented.
These and other objects, features, and advantages of the present invention may be more clearly understood and appreciated from a review of the following detailed description and by reference to the appended drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents graphical flow of the usage of the present invention.
FIG. 2 presents a flowchart of the usage and processes of a typical session of a participant's interaction with the present invention.
FIG. 3 depicts an exemplary user interface for the present invention as implemented on a web page
FIG. 4 presents an overview of the process of selecting items, presenting them to participants, and obtaining and recording ratings for the items presented in accordance with the present invention.
FIG. 5 depicts an exemplary database structure that may be used in accordance with the present invention.
FIG. 6 presents an overview of the item selection process according to the present invention.
FIG. 7 presents an overview of the process for calculating the selection score of each item.
FIG. 8 presents an overview of the process for computing a probability index for each item in accordance with the present invention.
FIG. 9 depicts an exemplary two dimensional array that may be used in accordance with the present invention to represent the resulting pool of items.
FIG. 10 presents an overview of the logic required to properly select a unique sample set to be presented to a participant.
FIG. 11 presents an overview of the process used to dynamically select a sample based on prior interest.
FIG. 12 presents an overview of the logical flow used to allow participants to rate a variable number of items.
OBJECTS OF THE INVENTION
It is an object of the invention to use statistical methods for the purpose of selecting which items should be presented to a survey participant. Statistical analysis is performed on the already collected responses, if any, to determine which items will be presented to a survey participant.
It is another object of the invention to use the standard error of the mean statistic to determine the confidence level in the mean rating of an item that was presented to subset of the entire population. Then, the confidence level is used to determine which items would benefit from additional ratings by additional participants and should be selected to be rated by future participants.
It is another object of the invention to provide a system that is operative for selecting items to present to a participant dynamically rather than having the questions predetermined at the time the survey is created. This dynamic selection feature is not dependent on how previous questions were answered in the same survey response. Rather, the items are selected for presentation based on how many participants have previously rated each item in the list of items, and how closely those participants agree on the ratings to each item.
It is a further object of the invention to provide a system in which participants in a survey can contribute items to the list of items such that the contributed items are available for presentation to future participants in the same survey.
It is a further object of the invention to use an adjustment factor to cause items in the database to be selected more or less often depending on the number of times the items have already been selected and presented to previous participants.
It is a further object of the invention to use an adjustment factor to cause items to be selected more or less often based on the ranking obtained from previous participants of a survey.
It is a further object of the invention to use a random selection of items to be presented to participants of a survey.
It is a further object of the invention to use a self-adjusting selection process based on previous responses during the same survey. The process is self-adjusting in that the subset of items to be presented to a participant is selected based on all previous responses, and the probability of each item in the database being selected is automatically adjusted as new items are collected and previous items are rated by survey participants.
It is a further object of the invention to provide a system that is operative for making a continuous transition from random selection of items to intelligent selection of items. Items are randomly selected when the survey process begins because no data is available for any of the items. As the process continues, the probability of each item being selected is continuously adjusted to a more intelligent selection as items are rated by participants and response data is collected. The transition from random to intelligent selection is a continuous process, rather than a process where at some point in time or maturity of the survey, the selection becomes more intelligent.
It is a further object of the invention to provide a system that is operative for enabling survey participants to return to the survey and change their original responses, submit new items, and rate new items that have been collected since the time of their previous response to the survey.
It is a further object of the invention to provide a system operative for selecting items to present to survey participants based on criteria defined by the administrator. The criteria may include attributes of the items, such as category, originator, priority, purpose, or any other attributes that may be tracked by an administrator for each item collected in maintained in the database.
It is a further object of the invention to provide a system operative for enabling a participant of a survey who is willing to rate more than the sample set of items to view and rate additional items.
It is a further object of the invention to provide a system operative for selecting items to present to a participant of a survey that are known to be of interest to the participant. The determination of what is known to be of interest can be made by the administrator's specification of selection criteria for particular groups of respondents. Alternatively, items that have words similar to the words used by the participant may be selected for presentation to the participant.
It is yet a further object of the present invention to provide a system operative for enabling survey participants to add comments to items that will be viewed by other survey participants during the course of the survey.
DETAILED DESCRIPTION OF THE INVENTION
I. Introduction
The present invention is generally directed to a computer-implemented system for estimating the preference of a list of items as perceived by a population of participants without having each participant rate each item available. The system may be implemented using a variety of computer technologies including, but not limited to, the internet, World Wide Web, email, client-server, and distributed systems.
The system of the present invention encourages participation by limiting the number of items that each participant will rate, thereby reducing the amount of time needed to complete the survey. The system uses statistics to select the items for which a low statistical confidence has been reached relative to other items. The items that have a low confidence level are those that have not been sufficiently rated, or that have been rated several times and have received inconsistent responses.
The system of the present invention may be used for numerous applications, including consumer research, employee evaluations, human resources, information systems planning, and architectural planning. Further, although items are described herein, it should be understood that the system of the present invention may be used to rank product concepts, people in an organization, or any other item that may be beneficially ordered by participant preference.
II. System Overview
FIG. 1 presents graphical flow of the usage of the present invention. A process manager 110 , serves as the administrator and overseer of the processes and systems afforded by the present invention. The process manager 110 interacts with a computer system 120 to create an electronic survey and sends electronic invitations 130 via email to the prospective participants of the survey.
Participants 140 interact with the computer system 120 and are allowed to input items 150 to the database of items 500 as specified in the present invention. The computer system 160 executing programs that are implementing the algorithms and methods in accordance with the present invention will then select a subset of items to be presented to, and rated by the participant 170 .
The responses 180 that are received electronically from the participants are then collected by the computer system 190 executing the programs that are implementing the algorithms and methods in accordance with the present invention. The responses 180 are processed by the computer 195 to produce reports of ranked items. The responses 180 are also processed in accordance with the present invention to adjust the selection probabilities of the plurality of items so future participants are presented with the items that are in most need of additional data to improve the confidence in the accumulated mean rating.
FIG. 2 presents a general overview of the system of the present invention. First at 210 , a participant is presented with an invitation to participate in a survey. If the participant consents to participating in a survey, the system selects a sample of items from the database 220 and presents the items to the participant 230 . The participant rates the items according to the participant's preference 240 . The participant is also able to rate items that the participant generates and inputs into the survey 250 . When the participant indicates that the rating is complete, the results of the survey, including the new items, are stored in a database 260 .
FIG. 3 depicts an exemplary user interface for the present invention as implemented on a web page. In this example, each participant is presented with a graphical user interface which contains a section to allow the participant to submit a new item 310 . A sampling of items 320 from the plurality of items stored in the database are selected in accordance with the present invention. The participant is allowed rate 330 each item and submit the results so that they may be stored and used to further adjust the sample selection so that future participants will get a set of ideas where more data is needed.
FIG. 4 presents an overview of the process of selecting items, presenting them to participants, and obtaining and recording ratings for the items presented in accordance with the present invention. A plurality of items 410 are stored in a storage array 450 , either in memory or in a database. This invention provides a selection process 415 which is used to select a subset of the plurality of items 420 to be presented to the participants 425 . Each participant 425 and 435 are allowed to specify a rating for each item presented 430 . The ratings 430 are then stored in the storage array 450 where the selection process 415 will then compute selection values as specified in the present invention so that the items can be selected for presentation to future participants. Some of the participants may also choose to input a new item 440 , which is then incorporated into the storage array 450 and included in the selection process for subsequent participants.
FIG. 5 depicts an exemplary database structure 500 that may be used in accordance with the present invention. Each item or item is stored in an item table 510 , which contains basic information about the item. Each item is identified by a unique identifier 520 , in this instance named “ItemId”. The ItemId is a reference number that is used as the primary key for each item table 510 . The “Value” field 530 contains the actual text of the item itself. Each item also contains a status field 540 , in this instance named “ItemStatusID”, which may optionally be stored in a separate table 550 . The status 540 is used as part of the criteria for determining if an item is eligible for selection, as will be described in detail below.
The “TimesShown” field 560 is used in the computation of the confidence value for each item. The confidence value relates to the number of times an item has been presented to participants, and will be discussed in greater detail below.
When a participant inputs an item, the participant information may be stored in a different table, such as a “Users” table 570 . This enables efficient storage of participant information, particularly where a given participant submits more than one item. Each item has a “UserID” field 580 that uniquely identifies a participant record in the users table.
During the process of executing this invention, each participant is presented a subset of the plurality of items to rate. The ratings submitted by each participant are stored in a response rating field 595 . One row is added to the response table 590 for each item that is selected for a participant during the execution of this invention. Each row in the response table is initialized with a rating of zero. Once the participant actually rates an item, then the response table rating field 595 is updated with the actual value for that item as set by the participant.
The response table 590 is also used to determine if the participant is returning to survey as depicted in FIG. 6 , box 645 ; in which case the survey participant will be presented with the same set of items that were previously selected for the participant.
It should be noted that the system of the present invention does not depend on the mechanism by which the items are placed in the database. Thus, various database designs and storage mechanisms may be used as desired. Such designs and mechanism are well known by those skilled in the art and are not described herein.
An overview of the item selection process 600 is presented in FIG. 6 . The system first determines whether the participant is visiting the site for the first time 605 by performing a query to the database to see if a response has already been received for the participant (by userid). If the participant is visiting the site for the first time, a set of items is selected 1000 and presented to the user 615 . An item is selected for presentation to a participant if a statistical analysis of the data associated with the item indicates that more data is needed to improve the statistical level of certainty, or “confidence level” relative to the other items in the database. The confidence level will be increased for an item when more participants have rated an item or when the participants who have rated the item increasingly agree on the level of desirability or rating of the item. As such, there is no particular threshold or other absolute value to determine when enough participants have rated an item or when the participants who have rated an item agree enough.
Instead, a confidence score is computed for each item, as will be discussed in connection with FIGS. 6-10 . The confidence scores are used only to compare the level of confidence among two or more items to determine which items are most needing additional data. The items that have the lower confidence scores are the items that could benefit the most from additional ratings by participants. For example, if an item has been rated by many participants and the ratings mostly agree, the item would have a higher confidence score than an item that has only been rated by a few participants or that has been rated vastly differently.
After the items are selected 1000 and presented 615 , the participant may express his or her preferences for the various items presented 620 . The selection process 1000 is described in detail in Para 108 and FIG. 10 . Additionally, the participant may be afforded the opportunity to input one or more additional items, which are also rated by the participant. The responses are then stored 625 and entered into a response table 630 . Participants are allowed to input new items as shown in 670 and 680 . FIG. 6 illustrates a participant's ability to input a new item after rating existing items. The inputting of new items could also occur before the participant has rated items. In either case, each item input by a participant is stored in the item table 640 where it is available to be presented to another participant. Thus, an item input by one participant may be rated by one or many other participants.
The participants who are rating items may optionally return to the system at any time during the course of the survey program and participate again. When a participant returns to the system for a second or subsequent visit, the items previously evaluated by the participant are retrieved 635 from the item table 640 . Likewise, the participant's previous responses are retrieved 645 from the response table 650 using the UserId created. The previous items and responses are then displayed 655 . The participant is then able to modify the responses if desired 660 . The responses are then stored 625 and entered in the response table 630 . The new data is used in all subsequent computations of confidence factors.
III. Determining the Selection Score for Each Item
The selection score for an item determines the desired probability that it will be selected by future participants. There are several intermediate computations need to arrive at the selection score. This section describes how the response data from participants who have already rated an item are used to compute the intermediate values and ultimately the selection score.
First a mean of the responses is computed, and then an estimate of the standard deviation of the mean is computed. Once the standard deviation of the mean value is available, the standard error of the mean can be computed. The standard error of the mean is then translated to a confidence factor which is a representation of the amount of confidence we have in the accuracy of the previously accumulated responses on a scale of one to one hundred.
Before the confidence factor is used to compute a selection score, two additional factors are used to give the administrator of the system additional control over which items should be preferred for selection. The participation influence factor is an arbitrary number, specified by the administrator, which controls the amount of weight to be given to the count of the number of people who responded. The rank influence factor is an arbitrary number, specified by the administrator, which allows higher ranked items to have greater preference in the selection process.
A. Calculation of the Confidence Factor
FIG. 7 presents an overview 700 of the process for calculating the selection score of each item. As stated above, the selection score is used to determine whether a particular item will be selected for presentation to a participant. First, an arithmetic mean (μ) is calculated for the responses already collected for the item 710 . The arithmetic mean of the rating values is referred to as the “mean rating value”. The mean rating value provides a consolidated rating for all participants who rated the element. A mean rating value is not calculated until there are at least two responses ranking the item. The mean rating is calculated as follows:
μ
=
X
1
+
X
2
+
X
3
+
…
+
X
n
n
where X is the rating value and n is the number of times the item has been rated.
As data is collected over time, a “rolling” mean rating (μ′) is calculated using the previous mean rating (μ′), the new rating value (Xn), and the number of times (n) this item has been rated as follows:
μ
′
=
μ
(
n
-
1
)
+
X
n
n
Next at 720 , the statistical standard deviation (s) of the mean rating is calculated. The standard deviation of the mean rating represents the amount of agreement or disagreement among the population of participants who rated the item. The standard deviation is calculated using the “nonbiased” or “n−1” method. Although only a subset of the entire population of participants actually rated the item, this method estimates the standard deviation for the entire population.
s
=
n
∑
x
2
-
(
∑
x
)
2
n
(
n
-
1
)
Next, the standard error of the mean response is computed 730 . The standard error is calculated from the estimated standard deviation of the mean calculated above and the number of responses included in the computation of the mean as follows.
σ
M
=
s
n
where s is the estimated standard deviation of the mean rating and n is the number of times the item has been presented for evaluation. As can be readily seen from the equation set forth above, the number of participants responding to each item, and the degree to which they agree or disagree determines confidence level in the data for a given item. As the standard deviation decreases, the standard error also decreases.
The standard error will have a value between 0 and the maximum rating value of the item, inclusive. The maximum rating value may vary for each survey application as desired. Thus, for example, if the item can be given a rating from 1 to 5, the maximum standard error will be 5. The items with the highest standard error are preferred in the selection process because more data is needed to increase the level of certainty in the preference ranking. As the number of data points for an item increases, the standard error of the data collected for the item decreases. As the standard error of the data for an item decreases, the confidence in the mean rating increases and the data collected more accurately estimates the statistical parameter of the population.
Next, a confidence factor (cf) is calculated for the item 740 . The system always computes a confidence factor for each item regardless of how many items are stored in the item database at the time of the computation. The confidence factor is used to measure the need to obtain additional data for each item relative to the need to collect additional data for all other items. When items are selected to be presented, the items with the lowest confidence levels are preferred for selection.
The confidence factor is calculated using the standard error of the mean response and the maximum possible rating value for each item as follows:
cf
=
100
-
100
σ
M
M
where M is the maximum possible rating value of the item. The confidence factor (cf) has a value between 0 and 100. A confidence factor of 100 indicates maximum confidence in the mean rating value for an element. Theoretically, this is only achievable if an item is rated by each participant in the population, and each participant provides the same rating for the item.
A confidence factor is calculated for an item when as few as two responses are collected for the item. For items with less than two responses, the confidence factor is set to 0, which causes them to be favored for selection over the items that have at least two responses. Once an item has received two responses, the probability of selection is computed relative to all other items in the database. As additional items are added, the confidence factors are recomputed for all items.
According to the present invention, items that are added to the database during the survey process are given the opportunity to achieve fair rankings quickly with minimal bias or skewing of the data. A low confidence factor will be computed for later arriving items because they have fewer respondents, thereby causing the newer items to be selected more frequently than earlier arriving items. The newer items will be selected more frequently until the confidence in the data collected for the newer items gains equality with the earlier items. As such, the system of the present invention provides a significant advantage over traditional survey methods in which new items are always at a disadvantage over items that were in the database from the beginning of the process. In such traditional systems, a set of items must be compiled before the process begins, and if new items are collected after the process begins, the new items must wait for a second survey.
B. Use of the Participation Influence Factor to Influence the Confidence Score
Still viewing FIG. 7 , according to another aspect of the present invention, the system administrator may specify an additional factor 750 that will cause the number of participants rating an item to have more influence in the confidence score than would otherwise be computed using the confidence factor alone. This additional factor is called the “participation factor” (pf).
The participation factor is calculated using the number of times the item was presented and the total number of times all items were presented as follows:
pf
=
N
P
⨯
cf
where N is the number of times the item was presented, and P is the total number of presentations of all items.
A “participation influence factor” (pif) may be used to control the degree to which the participation factor influences the confidence score. The participation influence factor can be adjusted to give more or less weight to the number of participants who responded. When the participation influence factor is adjusted to a high value, the number of people who have provided preference data for an item becomes the dominant factor in the computation of confidence in the data collected for that item. Also, when the participation influence factor is adjusted to a high value, the standard deviation, or amount of agreement among the people who have provided preference data, becomes less of a factor in the computation of the confidence in the collected data for the item. The participation influence factor can be adjusted to a neutral position, which causes the confidence factor to be computed using only the generally accepted calculation for standard error.
To control the degree to which the participation factor influences the confidence score, an additional factor is introduced. This “adjusted participation factor” (apf) is calculated as follows.
apf
=
N
P
⨯
cf
⨯
pif
As is readily observed, if the participation influence factor is set to 0, the adjusted participation factor will be 0 and have no influence on the confidence score.
C. Calculation of the Confidence Score
Next, the confidence score (cs) for a particular item is computed 760 . The confidence score is a measure of the relative amount of confidence in the statistical mean rating calculated from the data provided by the participants who rated the element. It should be noted that the confidence score cannot be computed until at least two participants have rated an element. The confidence score is calculated for each element as follows:
Cs=cf+apf
The system of the present invention does not use the confidence score to determine an absolute selection order. Rather, it uses the confidence score adjust the probability that each item will be selected. This will cause some items that already have a higher confidence factor in the data collected to be selected and presented to participants along with the newer items with lower confidence in the data. Without this probabilistic approach, it would be likely that newer items would be selected and presented only to newer participants and existing items would only be selected for rating by early participants. Thus, the present invention enables a more random selection of items to be presented, while showing items that need additional data more frequently.
D. Use of Adjusted Mean Rating and the Rank Influence Factor to Influence the Confidence Score
In some instances, it might be desirable to favor the selection of items with a higher mean rating over items with a lower mean rating. For instance, there may be a situation in which there is a greater need for certainty about the order of preference of high ranking items, and there is little or no concern about the order of preference of low ranking items. By way of specific example, a survey may be initiated to identify items in which to invest resources in. In such an example, there would be little interest in low ranking items because such items will not be considered. However, if the objective is to rank employees for the purpose of terminating the lower ranks, the need for confidence in the lower rankings is equally as important as the higher rankings.
In either of such instances, the system still uses the confidence score computed above to determine which elements need more data. However, the use of the adjusted mean rating (amr) and rank influence factor (rif) enable the accumulated mean rating of an element to have a controlled amount of influence on its selection score.
First, according to one aspect of the present invention, the ratings for a set of items may be rescaled between the minimum and maximum ratings to more clearly discern the order of preference between the items 770 . The rescaled mean rating is called the “adjusted mean rating”. The adjusted mean rating (amr) is computed as follows:
amr
=
100
⨯
(
R
max
-
R
min
)
μ
where R max is the maximum rating that was given to the items in the repository, and R min is the minimum rating that was given to the items in the repository.
Second, according to yet another aspect of the present invention, the amount of influence that the adjusted mean rating has on the selection score may be controlled by applying an externally controlled factor called the “rank influence factor” 780 . The rank influence factor (rif) may be adjusted to increase or decrease the probability of an item being selected to be presented to a participant based on the actual ranking of the item in relation to the other items. If the rank influence factor is set to a high value, items with a higher current ranking are more likely to be selected. If the rank influence factor is set to 0, the adjusted mean rating will have no influence on the selection score, as will be described in detail below.
E. Calculation of the Selection Score
Finally, the selection score (SS) is calculated 790 as follows to determine which items should be preferred in the selection process:
SS
=
cs
-
rif
⨯
amr
⨯
cs
10000
The selection score is calculated for each item in the item database. The items that will be selected are those with the lowest scores, as will be described in further detail below.
IV. The Item Selection Process
A. Overview
After a selection score is computed for each item, the desired probability that a given item will be presented is computed. Specifically, the selection score calculated above determines the probability that an item will be selected and, therefore, the frequency at which it will be presented to participants.
For purposes of explanation only, the selection process may be compared to placing numbered balls in a barrel and randomly drawing balls out of the barrel. For instance, if 100 balls, each having a unique number between 1 and 100 are placed in the barrel, each has a 1% chance of being drawn from the barrel. To increase the probability of a number being selected, more balls with the same number are placed into the barrel. Instead, if there were 100 balls in a barrel and 30 of them are numbered “12”, a random selection from the barrel would effect a 30% chance of drawing a ball with the number 12 on it.
According to one aspect of the present invention, no assumptions are made about the number of responses that will be ultimately received for a given item. Instead, the system of the present invention selects the best sample set based on information available at the time of selection. Likewise, the total number of responses that will be collected for the set of items or for any particular item is unknown at any time during the process. Thus, the system of the present invention uses the number of responses already collected when computing the confidence factor and selection probabilities. Sample selections are made based on probabilities that were computed just prior to the selection and the items that are in most need of additional data at that time are the most likely to be selected for the sample.
B. Calculation of the Probability Index
FIG. 8 presents an overview of the process for computing a probability index for each item in accordance with the present invention.
First, using the selection score calculated above 810 , a normalized score (Sn) is computed 820 for each item as follows:
Sn
=
100
(
1
-
SS
∑
ss
)
The normalized score has a value between 1 and 100. As the value approaches 100, the probability of selection of the item increases.
If the sum of the selection scores is zero, then the normalized score is set to 100. The sum of the selection scores will be zero when none or the items have been rated, or when all ratings are zero. In either instance, the normalized score for each and every item will be set at a value of 100, thereby providing each item an equal opportunity to be selected for presentation to a participant.
In many instances, the normalized score is concentrated around a relatively small number of scores, e.g. between 90 and 100. In this instance, a distributed score (Sd) may be calculated 830 for each item across a range of values from 1 to 100 as follows:
Sd
=
100
Sn
-
Sn
min
+
1
Sn
max
-
Sn
min
It should be noted that if Sn max is equal to Sn min then all items have the same rating. This could occur when none of the items have been rated or when all items have the same mean rating. In either case, the distributed score for each and every item is set to 100, thereby making each item equally available for selection.
The desired probability of selection (S prob ) is then computed 840 for each item as follows:
S
prob
=
Sd
∑
Sd
The probability of selection of each item is then multiplied by the size of the item selection pool, as defined by the administrator or manager of the system, to determine how many times the item should be represented in the set. This value, called the “probability index” (Si), is calculated 850 as follows:
Si=S prob ×PoolSize
A selection pool size of at least 1000 is recommended to avoid excessive rounding error that could skew the results. However, the actual pool size may be increased if the number of items is expected to be greater than 1000. After the pool is created and each item is represented in the pool the number times as indicated by its probability index value, a random selection of items from the pool will yield the desired results.
C. Representation of the Pool of Items
Turning to FIG. 9 , a two dimensional array 900 may be used in accordance with the present invention to represent the resulting pool of items. The array 900 contains one row for each item. Each item in the table includes a low index number 910 and a high index number 920 . These index numbers represent how many times each item is represented in the pool. For example if an item had a low index value of 10 and a high index value of 15, the item would be represented six times in the pool. The table could be compressed even further by only storing the high index. By storing the low index and the high index for each item the desired selections can be efficiently processed by obtaining a random number then using the following SQL Select statement: SELECT TOP 1 ITEM FROM POOLARRAY WHERE RANDOM_NUMBER BETWEEN LOW_INDEX and HIGH_INDEX. This statement will select the single item where the random number falls between the low and high indexes for that item.
The process of using a random number to select an item will be repeated enough times to retrieve the desired number of items according to the sample size that is requested. To fill a sample set with the desired number of unique items that all meet predetermined criteria, the logic is somewhat more sophisticated than a simple loop that repeats a fixed number of iterations.
D. Selection of the Sample Set
FIG. 10 presents an overview 1000 of the logic required to properly select a unique sample set having the desired sample size, and in which each item meets the specified selection criteria according the status of the items.
First, the desired sample size is obtained 1005 . This is the maximum number of items that will be selected and presented to a participant. The number of items will be equal to the sample size unless the number of items that are available and eligible for selection is less than the sample size. The sample size is a parameter that is specified by the administrator of the system.
Next, the system determines whether the number of items in the database is less than or equal to the sample size 1010 . If the number of items in the database is less than the number of items in the sample size, all items that meet the selection criteria are inserted into the sample set 1015 .
The selection criteria are specified by the administrator and consist of logical conditions based on the attributes of each item. For example, only items in an “active” status may be eligible for selection. Items in a “declined” status would not meet the selection criteria. Various conditions may be specified by the system administrator as desired. If the status or attributes of an item change during the survey process such that the item meets the defined criteria, the item becomes eligible for selection. If the criteria for selection changes during the process, all items that meet the criteria then become eligible for selection. When items become eligible for selection, a confidence factor is computed for the items, and the items are selected as described above.
If the number of items in the database is not less than the number of items in the sample size, the counter is set to a value of 0 and the selection process continues 1020 .
Next, if the counter is less than the sample size 1025 , a random number between 0 and the maximum probability index value is then generated 1030 .
Next, using the random number generated in step 1030 , an item is selected from the pool 1035 . The item selected has a low index value less than or equal to the random number and a high index value greater than or equal to the random number. If the selection pool table was constructed properly, such as that in FIG. 9 , one and only one item will qualify for selection.
Next, still viewing FIG. 10 , the item selected above is compared to any items already selected for the sample set 1040 . If the item was previously selected for the sample set, the system returns to step 1030 and repeats the process until an item is selected that has not already been selected for this sample set.
Next, the system verifies that the selected item meets any selection criteria specified by the administrator 1045 . If the item does not meet the selection criteria, the item will not be made part of the sample set. The process then repeats until items are selected that meet the selection criteria.
Next, the selected item is inserted into the set of items for the sample set 1050 . Additionally, a value of 1 is added to the counter for the number of items in the sample set 1055 . If the number of items now in the sample set is equal to the desired sample size, the selection of the sample set is complete and the items are displayed to the participant 1060 . If not, the process repeats until the desired sample size is attained.
E. Selecting Items within a Participant's Scope of Interest
According to another aspect of the present invention, a set of items may be presented to a participant based on the particular interests of the participant. The various interests of a participant can be determined by the system either statically or dynamically.
To determine a participant's interests statically, the participant is presented with a query about the participant's interests. Then, selection criteria specified by the administrator restrict the number of items that are eligible for presentation to a given participant. These criteria are used during the selection process previously described in connection with in FIG. 10 .
Dynamic determination of a participant's interest is conducted by examining the contents of items previously submitted by the same participant, and selecting other items relating to the subject matter submitted. For example, if a participant submits several items related to the topic of “security”, the system will select other items related to security for presentation to the participant.
FIG. 11 illustrates the process 1100 used to dynamically select a sample based on prior interest. First, an empty pool of items that are eligible for selection for the participant is created 1110 . The pool is then populated with appropriate items, and used as the selection pool in the selection process as previously described in connection with FIG. 10 .
After the participant has input the rating information, a query is made to the database of items to determine keywords relating to items that were submitted by the current participant 1120 . This query can be adjusted by the administrator to also include items that have been rated by the current participant where the rating value for those items surpasses a specified level. When a participant gives an item a high rating, this can be used as an indication that the participant has interest in the type of item or subject of the item and can therefore be considered a good participant to rate other items of the same or similar type or subject matter.
Each of the items that match the query is used in a similar manner 1130 to find other items in the database 1140 that meet a specified degree of similarity. The results of this search are then used to populate the selection pool 1150 , which is then used as the selection pool for the process depicted in FIG. 10 .
VI. Allowing Participants to Rate a Variable Number of Items
According to yet another aspect of the present invention, a participant is able to view and rate more items than provided in the subset presented. This provides significant advantages over presently available survey systems, which present too many questions to the participant and risk losing the participant. According to the present invention, a smaller, more reasonably sized, subset of items may be selected for an initial presentation to the participant, who can then choose to view and rate additional items if desired.
FIG. 12 presents an overview 1200 of the logical flow used to allow participants to rate a variable number of items.
First, a sample size for the participant is determined 1210 . If desired, the system administrator may allow the participant to choose how many items to view or rate before the process begins. In this case, the participant is simply selecting the sample size. After the sample size is selected 1220 , the process continues with items being selected and presented 1230 as described above.
Additionally, the participant may view and rate a set of items, and then choose to view and rate additional items. In this instance, after the participant has rated the first set of items presented, the participant is offered an opportunity to request another sample 1240 . The sample size may or may not be fixed, and may be established by the administrator or participant as desired. If the sample size is fixed, the administrator may specify the initial sample size, and the size of any subsequent samples selected for a participant. Likewise, if the sample size is selected by the participant, the administrator may specify the upper and lower limits of the sample size.
It will be understood that the foregoing relates only to the preferred embodiments of the present invention, and that numerous changes may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A system and method for confidence-based selection of items for use in conducting a computer-implemented survey. The survey presents information about a selected plurality of items to a survey participant, to elicit survey feedback information. Information regarding the plurality of items is stored, the stored information including display information about each of the plurality of items for presentation to a survey participant. A subset of items for presentation to a survey participant is selected in accordance with a predetermined selection algorithm. Information corresponding to the selected subset of items is displayed to the survey participant via a survey user interface. Rating information is input by the survey participant via the survey user interface indicating the survey participant's preferences as to items in the presented subset of items. The rating information is utilized in various manners to affect the selection algorithm for a subsequent survey.
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This is a continuation-in-part application of Ser. No. 750,961 filed 7/2/85, now abandoned.
BACKGROUND OF THE INVENTION
In the past Interior "C" Enamels which yield opaque films, U.S. Pat. No. 3,450,656, Col-1, Line 33-38, have been used to coat the interior of vegetable cans which contain wet foodstuffs. These "C" enamels, single package or two package, bake to give an opaque or milky film.
The zinc oxide pigment plays a two-fold role in protecting the appearance of the container and the packed food. Sulfur compounds in food may react with the ferric ions in the container's surface producing black iron sulfide. In the presence of zinc oxide, the sulfur compounds react preferentially with the zinc oxide forming white, zinc sulfide. Also, the opaque nature of the film produced by dispersing zinc oxide pigment in the varnish or enamel provides a visual carrier or mask to any unsightly discoloration of the metal surface, if it should occur.
The milky appearance is not always desireable to canners but is necessary in order to achieve good sulfide stain resistance. Many canners like the traditional clear gold appearance seen in many food cans, but they must accept the opaque look of a conventional "C" enamel for performance because the alternative was not available.
Prior to this invention the zinc oxide was incorporated simply by stirring or milling at room temperature a zinc oxide paste predisperson into the enamel or varnish of the coating.
This is a relatively inefficient manner for incorporating zinc oxide and required zinc oxide levels of 1% or more, U.S. Pat. No. 3,450,656, for acceptable sulfide stain resistance.
The metals used to fabricate cans for food packaging have changed over the years. Previously, cans had tin coating weights of 0.25 pounds of tin to 1.00 pounds of tin per 435.4 square feet of metal. Today, tin coating weights have been reduced to about 0.20 pounds of tin per 435.4 square feet of metal. This low tin weight steel is called L.T.S., or lightly tinned steel. This point is critical to both the packer and the coating supplier since it is easier to achieve good sulfide stain resistance on high tin weight steel than low tin weight steel. The thicker tin coating over the iron acts as a secondary or backup coating to protect the iron from the formation of iron sulfide. The current invention provides even greater stain resistance than the conventional "C" enamels since we are coating L.T.S. with a transparent, gold film.
In recent years, water-based coatings have found increasing use as interior coatings for food cans. The reason is changing laws and restrictions on solvent emissions which precludes the use of conventional solvent based coatings.
Some of the problems with most water based sanitary enamels are poor sulfide stain resistance and marginal adhesion on low tin weight cans, after steam processing. Steam processing is the process where the food which is being canned is heated 250° F. in the can in order to sterilize it.
In an effort to cut costs, canners are not only using low tin weight metal, but are not subjecting the metal to the washing treatments necessary to remove surface contamination which causes adhesion failures.
SUMMARY OF THE INVENTION
We have found that in order to guarantee good adhesion to slightly dirty or oily low tin weight metal, an acid number of 200 or greater (in the base resin) is necessary. This means that based on the acrylic portion of the varnish or enamel that our coating contains at least 30% carboxyl acid by weight on solids. By on solids, we mean that the solvents are subtracted out and then the precentages are calculated.
This is unique for "C" enamels because acid numbers of no greater than 15 have been necessary in the past U.S. Pat. No. 3,450,056 Col. 3 Lines 63-70, with most examples having acid numbers less than 0.5 U.S., Pat No. 3,4540,656, claims 6, 7.
We have also found that in order to guarantee good stain resistance with water based "C" enamels on low tin weight metal we must incorporate the zinc oxide more efficiently than in the past. To do this, we have found that if we react the zinc oxide with the amine neutralized carboxyls of the acrylic portion of the polymer at elevated temperatures the zinc oxide becomes solubilized. Solubilizing the zinc oxide yields more surface area of zinc oxide available to react with sulfide and therefore we need less zinc oxide than in conventional "C" enamels. Our zinc oxide levels are less than 1% by weight.
It is the object of this invention to describe a procedure for producing clear "C" enamels by reacting a zinc oxide predisperison with a water based high carboxyl containing acrylic-epoxy-phenolic polymer system at elevated temperatures.
It is the object of this invention to describe a water based clear "C" enamel which has excellent adhesion to low tin weight metal used to make cans today.
It is the object of this invention to describe a clear "C" enamel which has less than 1% zinc oxide and has resistance properties equivalent to conventional "C" enamels with 1% or more zinc oxide.
It is the object of this invention to describe a clear water based "C" enamel which contains very high carboxyl acid levels on acrylic solids in the enamel.
In particular, this invention relates to water based single package "C" enamels which when baked yield clear rather than opaque films. These coatings which contain less zinc oxide than conventional "C" enamels have better sulfide stain resistance (than conventional opaque "C" enamels) on low tin weight cans. These clear "C" enamels also contain much more carboxylic acid, a higher acid number, on solids in the let down enamel than conventional "C" enamels.
The clear nature (of the film) of the single package "C" enamel here is due to the heat treatment of the zinc paste in the presence of a highly carboxylated acrylic resin system.
The "C" enamel composition of this invention is produced in a two step procedure. The first step is the formation of a stable zinc paste. The second step is the blending of the stabilized zinc paste with a high acid number water reducible resin system under controlled temperature conditions. The base resin and zinc paste are combined at elevated temperatures, 60° C., under vigorous agitation. The blended resin system is then neutralized with an amine, such as ammonia or dimethylaminoethanol or any other organic amine, to a predetermined degree, and finally reduced with water to a solids level and viscosity required for applicaiton.
DETAILED DESCRIPTION OF THE INVENTION
The clear single package "C" enamel of the present invention is produced by reacting a zinc oxide paste predisperison with the enamel or varnish portion of the coating at elevated temperatures.
According to this invention, a zinc oxide paste is prepared by dispersing the pigment in a carboxyl functional, partially neutralized aqueous solution of an acrylic resin to a grind fineness of 5-15 microns as measured on a Hegman gauge. Any of the techniques known to the art, such as Netzch, sand or ball milling, as well as Cowles dispersing may be used to prepare the grind. We prefer using a two stage procedure. In the first stage, a predispersion of the zinc oxide is made by slowly mixing the pigment with an aqueous solution of carboxyl funcitonal acrylic resin. The second stage is the addition of the predispersion to a ball mill where it is ground to the desired fineness.
The acrylic resin used in the paste grind should be of such viscosity as to allow proper grinding, and may be prepared by any of the techniques known to the art. The acrylic resin used in the paste has a preferred acid number of between 100 and 175 mg KOH/g. Monomer compositions preferred are those which provide the proper degree of hardness, flexibility, chemical resistance and rheological characteristics ot the finished enamel. Characteristics of a typical acrylic resin, suitable for use in the preparation of a zinc oxide paste are described in Example 1. The acrylic resin may be prepared by conventional solution polymerization. Preferred monomers are styrene and substituted styrenes, acrylic and methacrylic esters, acrylic and methacrylic carboxyl and hydroxyl functional monomers, acrylamide and substituted acrylamides, and acrylonitrile.
The base resin used in the production of the finished "C" enamel may be either a carboxyl containing acrylic, or an acrylic/epoxy copolymer or co-resin. The base resin, which should be water dispersible, may be prepared by any of the methods taught in any of U.S. Pat. Nos. 4,482,673; 4,247,4329; and 4,458,040. Preferred acid number range for the acrylic portion of the base co-resin is between about 200 and about 250. Preferred monomer composition are similar to those described in the above mentioned patents.
Coatings prepared using this procedure may be modified by the addition for thermosetting phenolic resin or an amino resin. If the modifying resin is water soluble or dispersible it may be added after the paste and base resin have been blended and reduced with water. If the phenolic resins or amino formaldehyde resins are water insoluble, they may be added to the paste and base resin blend prior to the addition of water. The surfactant activity of the acrylic is sufficient to carry the water insoluble resin into the aqueous dispersion. Non-heat reactive phenolics may also be used for their chemical resistance and plasticizing affect on the baked film.
Examples of phenolics which may be used are Union Carbide's BKR 2620, BK5918 and CK2400. Reichhold's Varcum 5476,8357 and 8345 are also useable.
Examples of acrylic/epoxy/phenolic "C" enamels are detailed in Examples 3, 7 and 9. An acrylic/epoxy "C" enamel is detailed in example 10.
The "C" enamel composition may be applied to metal, flat sheet stock used in the production of food containers by roller coat application. These compositions may also be useful in spray application to the interior of pre-beaded or post-beaded preformed metal containers. Beading is a process whereby profile rings are fabricated into the can to increase the strength of the can walls. If the container is post-beaded i.e., profile rings fabricated into sidewalls after the coating is applied and cured, the coating composition must be capable of providing sufficient lubricity to the metal surface to prevent damaging the baked film. For this reason, an integral part of the "C" enamel formulation for post-beaded cans is a wax lubrication. The coating is designed so that the lubricant will "bloom" to the surface of the cured film. During the process of fabricating the side-wall rings the surface lubricant provides the lubricity which prevents scratching or tearing of the film.
Coefficient of friction of the surface, or surface lubricity, may be measured by the use of an Altek, manufactured by Alteck of Torrington, CT, or by a Jon Wood Slip Angle Mobility Tester, Jon Wood Company, Kansas City, Mo.
"C" enamels may be spray applied to the interior of pre-beaded cans and baked. Film discontinuities or weak spots may be visualized by filling the coated can with a dilute solution of copper sulfate in dilute hydrochloric acid.
Chemical resistance of the coated can is measured by packing the container with a vegetable which gives severe under film staining, such as peas or corn. The packed container is first processed for 1 hour at 250° F. prior to storage for 30 days at 120° F.
Flexibility of flat sheet formulation is evaluated by applying the enamel to tinplate, by direct roller coater, at the correct film weight, and baking the enamel at the specified temperature for the specified time. A 307 mm diameter can end is punched out, and the end subjected to dilute copper sulfate solutin. The performance of the end is rated by visual inspection.
In like manner, chemical resistance is evaluated by stamping out 307 ends and using them as the top and bottoms of cans packed with aggressive foods, such as peas, corn or dogfood. Performance is rated by a visual inspection of the degree of staining caused by the packed food on the top and bottom ends, after 30 days at 120° F.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrating the invention are the following examples, which, however, are not to be construed as limiting the invention to their details. All parts and percentages in the examples as well as throughout the specification are by weight unless otherwise indicated.
EXAMPLES
Example 1
Acrylic used in the manufacture of zinc oxide paste
A carboxyl functional acrylic resin of acid number 120 is prepared in butoxy ethanol. The resin, reduced to 50% non-volatiles, has a viscosity of 240 P. Molecular weight of the acrylic polymer is approximately 40,000 (Mw measured by GPS vs. polystyrene).
Example 2
Production of the zinc oxide paste
The acrylic resin of Example 1 is neutralized to approximately 70% of theoretical, and reduced with water to 40% nonvolatiles. Zinc oxide is added to a ball mill and milled solution for 24-48 hours. To allow easier handling, the ball milled paste is blended with additional acrylic from Example 1 which has been neutralized to 70% with dimethylaminoethanol, and reduced with water.
______________________________________PASTEACRYLIC RESIN FROM 1 195.40DIMETHLAMINOETHANOL 16.40WATER 20.13ZINC OXIDE 305.28BUTANOL 8.07PASTE REDUCTIONACRYLIC RESIN FROM 1 333.29DIMETHYLAMINOETHANOL 13.67WATER 107.76 1000.00SPECIFICATIONSPIGMENT/BINDER 1/0.8BISCOSITY 15,000 cps______________________________________
Example 3
Preparation of Aqueous Clear "C" Enamel
A solution of Epon 1009 in butanol and butoxuethanol is made at 60% non-volatiles. An acrylic resin with at least 30% carboxylic acid based on solids, and an acid number of 200 mg KOH/g and molecular weight (Mw) 40,000, is prepared at 55% non-volatiles in butanol and butoxyethanol. The epoxy solution and the acrylic solutions are blended, and the temperature of the solution raised to 80° C. The acrylic and epoxy resins are allowed to react for 1 hour. A 60% solution of a thermosetting phenolic, such as Union Caribde's CK2400 or Richhold's Varcum 8343, in butoxy ethanol is then added to the acrylic/epoxy solution and mixed for 1 hour to ensure homogeneity. Water is added to reduce the resin solution to about 40% solids. The paste in Example 2 is slowly added to the aqueous dispersion which is at 75° C. under agitation. The paste is mixed into the aqueous dispersion over 2 hours. Additional water, to reduce non-volatiles ot 23% and an aqueous lubrication is added.
______________________________________1. BUTOXYETHANOL 58.4 BUTANOL 25.0 EPON 1009 96.72. ACRYLIC RESIN 110.0 DIMETHYLAMINOETHANOL 6.83. PHENOLIC SOLUTION 112.54. WATER 416.45. PASTE 32.06. LUBRICANT 6.57. WATER 135.0 1000.0SPECIFICATIONSNON-VOLATILES 23.5, 10' @ 400FpH 7.6VISCOSITY 3,500 CS, BROOKFIELD, #3 SPINDLE______________________________________
After six months at room temperature the zinc oxide containing enamel was still homogeneous. Viscosity had risen from 55" in a Ford 4 cup to 75".
The following examples represent two acrylic variations using the same phenolic and epoxy solution. The acrylics are incorporated into single package "C" enamels in examples 7 and 9. The epoxy resin may be chosen from any of the commercially available "9" types, such as, Epon 1009 or DER 669.
Example 4
Epoxy Resin Solution
______________________________________Epon 1009 54.00Butoxyethanol 29.00Butanol 14.00 100.00______________________________________
Phenolics used to prepare the solution may be chosen from any of the commercially available thermoplastic or thermosetting resins provided by such suppliers as Union Carbide, Schnectady, Reichhold or Monsanto. Particularly useful, but not limited to them, are such phenolics as Reichhold's Varcum 6820, 5416 and 8345, and Union Carbide's CK 2400.
Example 5
Phenolic Solution
______________________________________PHENOLIC RESIN 60.0BUTOXYETHANOL 40.0______________________________________
Example 6
Acrylic Resin Solution
An acrylic resin is prepared by the following method. Cosolvent selection will depend on the method used to apply the final product, spray or rollercoat.
One third of the monomer catalyst blend is added to the reaction solvent and heated to reflux. The remaining two thirds are added over two hours.
______________________________________REACTION SOLVENTButanol 27.78MONOMER/CATALYST MIXStyrene 12.60Ethyl Acrylate 20.85Methacrylic Acid 16.34Benzoyl Peroxide .39SOLVENTButanol 22.04 100.00______________________________________
The acrylic reaction mass is kept at reflux for one additinal hour after the mix is in. Final nonvolatiles of the solution is 50%.
Example 7
Single Package "C" Enamel
As 1 package "C" enamel is prepared from the following formulation.
______________________________________EPOXY RESIN SOLUTION (4) 152.82ACRYLIC SOLUTION (6) 111.54DIMETHYLAMINOETHANOL 7.24______________________________________
The two resin solutions are blended and heated to 65° C. The amine is added and the temperature raised to 70° C. and held for 1 hour. The phenolic solution is then added and allowed to mix with the above for 1 hour.
______________________________________PHENOLIC RESIN SOLUTION (5) 109______________________________________
The paste for Example 2 is then added and the temperature maintained between 65°-75° C.
______________________________________ZINC OXIDE PASTE 30.5WATER 586.32LUBRICANT 7.66______________________________________
This product produced a stable "C" enamel with a viscosity of 1200 cps and a nonvolatile content of 23%.
Example 8
Acrylic Resin Solution
A product similar to 7 may be prepared from an acrylic containing the following component.
______________________________________REACTION SOLVENTButanol 29.85MONOMER/CATALYSTButyl Acrylate 9.85Acrylic Acid 14.95Styrene 27.36Benzoyl Peroxide .49SOLVENTButoxyethanol 19.92 100.00______________________________________
Example 9
Single Package "C" Enamel
A one package enamel is prepared from the following components.
______________________________________EXPOXY SOLUTION (4) 70.74ACRYLIC SOLUTION (8) 99.03DIMETHYLAMINOETHANOL 6.08______________________________________
The above are mixed and heated at 75° C. for 3 hours. A phenolic solution is then added and held at 70° for 1 hour.
______________________________________PHENOLIC SOLUTION (5) 82.05______________________________________
The paste from Example 2 is added, and the mixture held at 75° C. for 1 hour.
______________________________________ PASTE (2) 25.46______________________________________
After the hour hold, water and lubricant are then added.
______________________________________ WATER 707.45 9.19 1000.00______________________________________
Nonvolatiles of the composition are 23%, and viscosity is 1000 cps. Examples 7 and 9 were evaluated for chemical resistance and fabrication, and stability and were rated as excellent when compared to a 2 package system.
The following examples illustrate the preparation of a single package "C" enamel based on an acrylic modified epoxy resin.
Example 10
Single Package "C" Enamel
______________________________________EPOXY RESIN SOLUTION (4) 211.50ACRYLIC RESIN SOLUTION (6) 154.70DIMETHYLAMINOETHANOL 10.50______________________________________
The resin solutions 4 and 6 are blended and heated at 75° C. for 3 hours in the presence of dimethylaminoethanol. Paste from Example 2 is then added.
______________________________________ PASTE (2) 25.80______________________________________
under agitation. When homogeneous, the blend is further reduced with water and aqueous lubricant.
______________________________________WATER 585.80LUBRICANT 12.50 100.00______________________________________
The total nonvolatiles are 23.2% and the viscosity is 1400 cps. The coating was evaluated for chemical resistance, flexibility, and stability, and were rated as good compared to a similar product containing no zinc oxide.
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Aqueous "C" enamels which bake to yield clear, rather than opaque films, and which contain very high carboxylic acid levels in the enamel may be prepared by reacting a zinc oxide containing predispersion at elevated temperatures with a highly carboxylate enamel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase Application of PCT International Application No. PCT/IL2011/000616, international filing Date Jul. 31, 2011, claiming priority of Israeli Patent Application No. 207600, filed Aug. 12, 2010, each of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to the safety of airport runways. More particularly, the invention provides a side barrier preventing foreign object debris (FOD) from entering a runway and taxiway and endangering aircraft.
The importance of keeping airport runways and taxiways clear of FOD is well known.
An important consideration requiring attention is that the large diameter engines used by jet aircrafts are most often located under the aircraft wings, thus bringing the engine intake perilously close to ground level. As aircraft jet engines can be severely damaged on ingestion of even small solid particles, a clean runway is needed to ensure the safe operation of the engines, particularly during take-off.
The arrival of FOD on a runway or taxiway is often due to winds or wind caused by jet blast which collect FOD from an outside area. After the wind abates and before any airplane is cleared for take-off a clean-up crew may be sent to clear the runway for both incoming and outgoing aircraft. The resultant delays can have a ripple effect on other flights resulting in angry passengers and much fuel wastage as incoming aircraft circle the airport in a holding pattern.
While it may appear at first glance that the erection of a FOD barrier on each side of a runway is a simple matter, it must be realized that under various circumstances (pilot error, fog, under carriage malfunction, a collision avoidance maneuver etc.) an aircraft may fail to adhere to the line marking the runway center and collide with the FOD barrier. If the barrier is rigid such a collision is likely to result in loss of life, injuries and a wrecked aircraft.
Accordingly Prevost in U.S. patent application 2008/0175665, and U.S. Pat. Nos. 7,207,742 7,223,047 and 7,677,833 discloses an arrangement wherein a downward slope is created adjacent to each side of the runway. A water impermeable material covers the slope, at the bottom of which a line of artificial grass is to collect FOD driven by jet blasts and water run-off from the runway. The drawbacks of this system include the difficulty of cleaning the artificial grass and the high cost of creating two or 3 levels where only one level the surface of the runway exists presently.
SUMMARY OF THE INVENTION
It is therefore one of the objects of the present invention to obviate the disadvantages of prior art methods of clearing a runway and taxiways and to provide a side barrier which stops and reduces FOD before it can reach the runway and endanger aircraft thereon.
It is a further object of the present invention to provide a collapsible barrier which will cause no damage to an aircraft colliding therewith.
Yet a further object is to retain the FOD and allow for its collection or removal in an orderly manner.
Yet another object is to easily clean the runway from FOD without blocking it by the barrier.
Finally it is an object of the present invention to provide a barrier of aerodynamic characteristics.
The present invention achieves the above objects by providing a runway side barrier for preventing foreign object debris (FOD) from entering a runway used by aircraft, said barrier having ground attachment means and being constructed to collapse if the landing wheels of an aircraft impact said barrier and thus allow said aircraft to safely continue landing/takeoff/taxiing.
In a preferred embodiment of the present invention there is provided a barrier being provided with a plurality of rows of ground attachment items.
In a further preferred embodiment of the present invention there is provided a barrier being made of an elastomer, the height of said barrier being temporarily reduced by at least 80% when compressed by said landing wheels of said aircraft.
In another preferred embodiment of the present invention there is provided a barrier being made of a rigid material, the barrier profile including break points 37 allowing collapse of said profile under pressure of an aircraft landing wheel.
In a further preferred embodiment of the present invention there is provided a barrier wherein the barrier profile includes at least one opening which can be accessed for cleaning from a moving vehicle by use of standard cleaning tools and can be accessed by a robot or a cleaning person moving in a direction parallel to said barrier.
In a further preferred embodiment of the present invention there is provided a barrier further provided with drainage channels disposed between ground attachment means.
In yet a further preferred embodiment of the present invention there is provided a barrier further provided with support means for a row of spaced-apart landing lights disposed along the length thereof.
In another preferred embodiment of the present invention there is provided a barrier wherein means are provided for varying the height thereof.
In a most preferred embodiment the barrier is aerodynamic having one side convex while the other being concave.
The invention further comprises two methods for manufacturing and installing the barrier described herein.
In a first method of the present invention of installing a runway side barrier for FOD spaced-apart fold relief recesses are provided therealong, allowing said barrier to be transported from the manufacturer to an airport in a compact folded form.
In a second method provided by present invention a barrier is installed after being manufactured in discrete lengths for convenient storage and transport. One extremity of each length is formed in a hollow configuration to engage the unformed extremity of an adjacent length when deployed at the side of a runway.
It will thus be realized that the novel device of the present invention serves not only to stop FOD being blown onto the runway but also allows orderly collection, cleaning or removing thereof.
A very important feature of all embodiments of the invention is that even if the aircraft hits the barrier for whatever reason, the barrier will collapse and allow the landing wheel to crush the barrier without causing damage to the aircraft.
The invention shows how the barrier may be constructed using a wide variety of materials steel, aluminium, rubber and plastics.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described further with reference to the accompanying drawings, which represent by example preferred embodiments of the invention. Structural details are shown only as far as necessary for a fundamental understanding thereof. The described examples, together with the drawings, will make apparent to those skilled in the art how further forms of the invention may be realized.
In the drawings:
FIG. 1 is a plan view of runways in a present-day airport.
FIG. 2 is a further plan view the same airport, showing FOD encroaching on a runway of said airport;
FIG. 3 is a perspective view of the runways seen in FIG. 1 ;
FIG. 4 is a perspective view of the runways seen in FIG. 2 ;
FIG. 5 is a perspective view of a sheet metal embodiment, or any other material;
FIG. 6 is a perspective view of an embodiment made from an aluminium extrusion;
FIG. 7 is a perspective view of a further sheet metal embodiment;
FIG. 8 is a perspective view of a further similar embodiment provided with struts;
FIG. 9 is a perspective view of a further similar embodiment provided with struts which are configured to collapse;
FIG. 10 is a perspective view of a barrier supporting landing lights;
FIG. 11 is a perspective view of an embodiment allowing drainage;
FIG. 12 is a perspective view of an adjustable embodiment seen in a low position:
FIG. 13 is a perspective view of the same adjustable embodiment seen in a high position:
FIG. 14 is a view of a foldable embodiment and
FIG. 15 is a view of an embodiment comprising discrete joinable lengths.
DETAILED DESCRIPTION OF THE INVENTION
There are seen in FIGS. 1 and 3 several runways 10 , 14 typical of those found in a present-day airport. FOD 18 is seen accumulating near the runways 10 , 14 . These runways are interconnected by parking/taxing areas 12 , 16 used by aircraft 22 waiting for permission to take off.
The runways are clean, no FOD is encroaching on a runway of said airport; In FIGS. 2 and 4 the same runways are seen, with FOD encroaching on parking areas 12 , 16 and runways.
A preferred embodiment of the FOD barrier, to be installed on both sides of the runways according to the invention is seen in FIG. 5 and is made of sheet metal or any other suitable material. The barrier 34 is provided with two rows 36 38 of ground attachment items. If crushed by an aircraft 22 landing wheel, the damaged portion of the barrier 34 is discarded and replaced. Preferably the shape being aerodynamic profile—one side of the barrier the “FOD collection side” concave to enable stopping FOD from entering the runway and the other side of the barrier, having a convex shape.
The barrier embodiment 40 seen in FIG. 6 can be produced as an aluminium extrusion or rubber of about 350 mm is sufficient. As such, the present embodiment 40 can be produced at low cost but will need replacement if crushed by the landing wheel of an aircraft.
FIGS. 7 , 8 and 9 illustrate further embodiments 42 , 44 and 46 . The embodiment 42 seen in FIG. 7 is a simple low-cost barrier which collapses easily and is thus suitable for a runway serving light aircrafts.
The embodiment 44 seen in FIG. 8 is provided with support pillars 45 . The pillars 45 are driven into the soil if compressed by the passage thereover of a landing wheel. Thus there is a possibility of reusing the damaged section by repositioning the edge 48 upwards. In contradistinction thereto the supports 50 provided in the embodiment 46 seen in FIG. 9 are intended to break when compressed and are replaced thereafter.
Referring now to FIG. 10 , there is depicted a barrier 52 further provided with support means for a row of spaced-apart landing lights 54 disposed along the length thereof. The sheet metal profile provides a convenient protective housing for the electric cable 56 providing power to the lights 54 .
In FIG. 11 there is seen a FOD barrier 58 further provided with drainage channels 60 disposed between ground attachment means 62 . This drainage is useful in preventing standing water on the runway resulting from rain, washing of aircraft or the operation of fire extinguishers.
The barrier 58 seen is made of perforated metal 64 to allow drainage and to facilitate collapse when compressed by a landing wheel. Alternatively, other permeable materials may be used, such as recycled rubber.
Turning now to FIGS. 12 and 13 , there is seen a barrier 66 wherein hinged struts 68 are provided and are pivoted at 70 proximate to the upper edge 72 of the barrier 66 . A fixed actuator 74 is held substantially at ground level. An telescopic arm 76 forms part of the strut 68 near the fixed actuator 74 . The actuator 74 can shorten the strut 68 as in FIG. 12 for lowering the barrier 66 , or lengthen the strut 68 as in FIG. 13 to raise the barrier 66 .
Where it is foreseen that the profile height is to be set once only, the appropriate actuator 74 is a screw and nut arrangement which is hand set on installation to bring the barrier 66 to a chosen height.
However where it is intended to regularly change the height of the barrier 66 the actuator 74 comprises a screw and nut mechanism operated by a reversible direction electric motor. A central control station to operate the height adjustment mechanisms can be located in the control tower.
The actuator 74 may comprise a fluid power cylinder. The actuators 74 can be remotely operated from the control tower.
Height adjustability is advantageous where a lower position as in FIG. 12 is needed for small aircraft, while a higher barrier as seen in FIG. 13 is suitable for large aircraft.
FIG. 14 refers to a first method of installing an elastomer runway side barrier 78 against FOD. Spaced-apart fold relief recesses 80 are provided therealong, allowing the barrier 78 to be folded and stored, and then transported from the manufacturer or vendor to an airport in the compact folded form seen in the figure.
With regard to FIG. 15 there is illustrated a barrier 82 which is used in combination with a second improved method of installation.
The invention provides a method of installing a runway side barrier 82 . The barrier is manufactured in discrete lengths 88 for convenient storage and transport. One extremity 84 of each length is formed in a hollow configuration to engage the unformed extremity 86 of an adjacent length when deployed at the side of a runway.
Due to its construction and profile the removing of FOD which accumulated therealong is performed by ordinary cleaning tools know in the art.
The scope of the described invention is intended to include all embodiments coming within the meaning of the following claims. The foregoing examples illustrate useful forms of the invention, but are not to be considered as limiting its scope, as those skilled in the art will be aware that additional variants and modifications of the invention can readily be formulated without departing from the meaning of the following claims.
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A collapsible runway side barrier for preventing foreign object debris (FOD) from entering a runway and taxiway is disclosed. The barrier may have an aerodynamic profile, one side of the bather profile may be convex and the other side of the barrier profile may be concave. The side barrier may further have ground attachment elements and may be constructed to collapse if the landing wheels of an aircraft impact the barrier.
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BACKGROUND
[0001] With the advent of video recording technologies and of suitable media for storing such recorded video content, it has become common for individuals to possess an assortment of such recorded video content. For example, video tapes, such as analog or digital tapes, and digital video disks (DVDs) are readily available for purchase, enabling consumers to collect television shows, movies, sporting events, and other entertainment stored on these types of media. Consumers may, therefore, steadily amass a collection of televisions shows, movies, events, and so forth, through the continued purchase of such video tapes or DVDs. An individual's collection of video footage may also include television shows and events recorded by the individual onto video tape, DVD, or a digital video recorder (DVR). In addition, an individual's collection of video footage may include personal footage created by the individual using a camcorder, when such footage is stored on an analog or digital video tape, a DVD, or a magnetic memory card. In these various ways an individual may, over time, amass an extensive collection of purchased or created video content on a variety of different types of storage media.
[0002] As new types of storage media and formats arise, however, an individual may find themselves having to maintain a variety of different players in order to maintain access to the different media upon which their various videos are stored. In such circumstances, the individual may transfer contiguous or non-contiguous video content onto a common media type, such as by transferring video footage saved on video tapes onto DVDs. For example, an individual may copy the contiguous contents of a video tape to a DVD, essentially making a DVD version of the video tape. Alternatively, the individual may copy non-contiguous video content, such as excerpts from a video tape or from multiple video tapes, such that the resulting DVD contains only the desired video content from one or more video tapes.
[0003] This approach has the advantage of allowing the individual to discard older video player technologies, such as video cassette recorders (VCRs), and to take advantage of the benefits associated with the newer media technologies. Transferring a video from one media type to another, however, may be a laborious process, particularly if only select portions of the video content are to be transferred. For example, to transfer the video content on a video tape to a DVD, the video output of a VCR player may be connected to the video input of a DVD recorder such that the entire content of video tape may be recorded onto a DVD by simultaneously playing the video tape in the VCR and recording on the DVD recorder. However, if only select portions of the video tape are to be transferred, an operator must be present to record only the desired portions of the video onto DVD and to prevent recording of the undesired portions of the video. Alternatively, the functions of video tape playback and DVD recording may be combined into a single device; however, even in such a combined device, unsupervised recording of only portions of the video tape is not possible absent some amount of operator intervention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a flowchart depicting exemplary generation of an action plan comprising reference signatures and associated actions, in accordance with aspects of the present invention;
[0005] FIG. 2 is a flowchart depicting an alternative exemplary generation of an action plan comprising reference signatures and associated actions, in accordance with aspects of the present invention;
[0006] FIG. 3 is a flowchart depicting exemplary generation of a video file, in accordance with aspects of the present invention;
[0007] FIG. 4 depicts an exemplary system for generating a video processing action plan, in accordance with aspects of the present invention; and
[0008] FIG. 5 depicts an exemplary system for generating a video file, in accordance with aspects of the present invention.
DETAILED DESCRIPTION
[0009] As discussed below, embodiments of the present invention comprise a technique for identifying selected portions or frames of a video stream. These identified frames are used to prompt designated actions, such as recording or differentially processing the identified frames and/or a set of subsequent frames. For example, in accordance with aspects of the present invention, an operator associates different instructions, such as the beginning or ending of a recording operation, with different frames, to produce an action plan. The operator may produce this action plan by selecting frames (such as start or stop frames) or a common frame characteristic (such as a face or brightness level) that are associated with a recording or processing operation. The action plan can be used to automatically process a video stream based on the instructions and identified frames within the action plan. For example, in one embodiment, a frame associated with a start instruction automatically begins a recording operation while a different frame associated with a stop instruction automatically ends the recording operation. Similarly, in another embodiment, all frames having an identified content characteristic, such as a person's face, a geographic landmark, a structure or object, a date/time stamp, and so forth, are recorded while frames without the identified content are not recorded. In this manner, an action plan is used to enable unattended or automated recording or processing of a video stream, such as by a computer or other consumer electronic device, to generate an abbreviated or processed version of the video stream. The abbreviated or processed video stream can then be stored on a suitable medium, which may or may not differ from the medium on which the original video stream is stored.
[0010] Turning to the figures, FIGS. 1 and 2 depict different examples of the generation of an action plan that can be used in the processing of video stream. For example, FIG. 1 depicts a flowchart of an embodiment of the present invention in which an operator identifies one or more frames of interest and associates a desired action with each identified frame. An initial video stream 10 is played or displayed for a viewer, such as by displaying the frames of the video stream 10 (block 12 ). In one embodiment, the video stream 10 is obtained by reading an analog or digital video tape. In other embodiments, the video stream 10 is obtained by reading a DVD or a hard drive, such as in a personal computer or DVR. In further embodiments, the video stream 10 is obtained over a network connection, such as over the Internet, or over a television delivery medium, such as via a cable television connection or antenna.
[0011] The viewer identifies a reference frame 16 in the video stream 10 (block 14 ). In one implementation, the act of identifying the reference frame 16 is accomplished by pressing a button or switch of an input device or other selectable interface when the reference frame 16 is displayed. For example, in this embodiment, a reference frame 16 is identified when an operator pushes or otherwise activates a button on a remote control or keyboard when the frame is displayed. Alternatively, in a software embodiment of the depicted process, a reference frame 16 is identified by the operator via a graphical user interface for the software, such as by selecting a menu option or a virtual button displayed on a monitor.
[0012] A unique reference signature 20 is generated for the identified reference frame 16 (block 18 ). In one embodiment, the reference signature 20 is generated by the execution of a signature-generating algorithm. For example, in one implementation, the signature-generating algorithm generates a checksum based on the pixel values associated with the reference frame 16 , and the checksum serves as the reference signature 20 . In other embodiments, the signature-generating algorithm generates the reference signature 20 based on other information contained within the reference frame 16 , such as luminance, color, contrast, and so forth. The signature-generating algorithm may be a checksum function, as noted above, a hash or other encryption function, or any other function configured to or capable of generating a unique signature based upon one or more inputs derived from a video frame.
[0013] As will be appreciated by those of ordinary skill in the art, a unique reference signature might not be generated if a reference frame 16 is selected that is indistinguishable from other frames of the video stream 10 . For example, if multiple identical frames (such as frames or other images of uniform color or contrast, frames of a test pattern, frames of a static or unchanged scene, and so forth) are present in the video stream 10 and one such frame is identified as a reference frame 16 at block 14 , the resulting signature may not be unique, i.e., other identical frames would generate the same reference signature. To address this possibility, in one implementation the identification of the reference frame 16 at block 14 is limited to those frames having unique video content, i.e., limited to dynamic or non-repeated image content, as opposed to frames of uniform colors or patterns or other duplicative video content. In this embodiment, a preceding or subsequent frame having unique video content is identified as the reference frame 16 . For example, if an operator selects the reference frame 16 to indicate the initiation of a recording operation, the next unique frame is automatically identified by embodiments of the present invention as the reference frame 16 . Conversely, if an operator selects the reference frame 16 to indicate the termination of a recording operation, the most recent preceding unique frame is automatically identified as the reference frame 16 by embodiments of the present invention. In this manner, non-unique frames are automatically precluded from use as a reference frame 16 , thus preventing the generation of non-unique reference signatures 20 .
[0014] In other implementations, a sequential or time index is associated with each frame of the video stream 10 , such as during the display of the frames at block 12 . This index is used as part of the reference signature 20 or as part of the input to the signature generating algorithm such that a unique reference signature 20 is generated even though the selected reference frame 26 is not unique. In this manner, frames that are identical, repeated, or otherwise not distinguishable from one another can still be differentiated by their respective reference signature 20 .
[0015] In the depicted embodiment, the reference signature 20 is combined with an associated action 22 to form an action plan 24 that is used to process the video stream 10 . In one implementation, the associated action 22 is an instruction to begin or to cease recording of the video stream 10 . In other implementations, the associated action is an instruction to apply a filter, to adjust the sharpness, contrast, brightness, color, noise or resolution, and/or to otherwise alter other video characteristics of the reference frame 16 and/or subsequent frames.
[0016] In one implementation, the associated action 22 is generated by the act of identifying a reference frame 16 at block 14 . For example, a reference frame 16 is identified at block 14 when a “start” button is pressed by a user, thereby identifying the reference frame 16 and generating an associated action 22 , in this example the action of starting a recording process. Furthermore, in this example, a reference frame 16 is identified at block 14 when a “stop” button is pressed by a user, thereby identifying the reference frame 16 and generating an associated action 22 , in this example the action of stopping a recording process. These functions are repeated for each portion of the video stream 10 to be recorded so that, in this example, a reference frame 16 is selected at the beginning and end of each portion and associated with the appropriate start or stop command. The “start” and “stop” buttons pressed by the user may be on a remote control of a consumer electronic device designed for the playback and editing of video stream 10 . In other embodiments, the “start” and “stop” buttons or commands may be part of a graphical user interface of a software implementation of the present technique or keystrokes recognized by such a software implementation. In such implementation, the identified reference frames 16 and associated actions 22 are stored on a memory component, such as a memory chip or hard drive, either prior to compilation into the action plan 24 and/or as constituents of the action plan 24 . Once generated, the action plan 24 is used to record portions of the video stream 10 in an unattended, automatic manner.
[0017] In one embodiment, the action plan includes metadata 26 . The metadata 26 may be textual, numeric and/or audio annotations to be associated with a video file generated using the action plan 24 . For example, the metadata 26 may be a textual description of the contents of the video file generated upon implementation of the action plan 24 or may be a textual and/or numeric description (such as chapter headings, date/time stamps, synopses, and so forth) of the different video excerpts coded for recording and/or processing by the action plan 24 . Similarly, the metadata may be an audio clip or file, such as a verbal annotation or description or a piece of music.
[0018] Referring now to FIG. 2 , a flowchart is provided depicting another embodiment of the present invention in which the reference signature 20 is not generated based upon a frame extracted from a video stream. Instead, the reference signature 20 is generated, at box 30 , based on a video signal characteristic or a video content characteristic within a video stream. For example, in one implementation a video content characteristic of interest may be the face of a person. In such an implementation, a face recognition algorithm is employed at box 30 to generate a reference signature 20 for the face of interest. For example, such a face recognition algorithm can generate a reference signature associated with a face based upon one or more measured characteristics of the face, such as distance between the eyes or ears, nose length, hair, skin, or eye color, distance from chin to eyes, and so forth.
[0019] While a face is one example of video content that may be used to generate a reference signature 20 , other video content may also be employed. For example, a geographic feature (such as a mountain or beach), a structure (such as a landmark, monument, or building), an object (such as a football or car), a generated video characteristic (such as a date/time stamp), and/or any other displayed characteristic or feature may alternatively or additionally be used to generate a reference signature 20 . In such embodiments, a reference signature 20 is generated which is characteristic of the feature, structure, and/or object and which may be automatically searched for and identified within the frames of the video stream. Such reference signatures 20 are generated based upon characteristics of the feature, structure, and/or object that are discernible in the video content, such as the color, shape, texture, and/or proportions. For example, in one embodiment, the object of interest may be a jersey or uniform associated with a sports team. In such an embodiment, the reference signature 20 may be generated based on the colors of a jersey and their relative proportions and/or proximity to one another. Similarly, in another example, a reference signature 20 may be for a ball used in a sport. In this example, the reference signature 20 may be based on the shape of the ball (such as a football) or on a color pattern or scheme associated with the ball (such as a soccer ball).
[0020] The reference signature 20 generated in this manner is combined with an associated action 22 to form the action plan 24 . For example, in an embodiment in which the reference signature 20 corresponds to a face, an associated action 22 may be to record those frames of a video stream in which the reference signature 20 is present. In this manner, those portions of a video stream in which the face of the person of interest is displayed are recorded. Conversely, the associated action 22 may be to not record those frames of a video stream in which the reference signature 20 is present. In this manner, those portions of a video stream in which the face of the person of interest is displayed are not recorded.
[0021] Similarly, if the characteristic of interest from which the reference signature 20 is derived relates to an image quality characteristic, such as brightness, contrast, color, sharpness, contrast, noise, resolution, and so forth, the associated action 22 may be a corresponding image quality enhancement, such as a sharpening or brightening operation. For example, in an embodiment in which the reference signature 20 is based on frame brightness and in which the frame brightness is discernible from the reference signature 20 , frames with brightness below a desired threshold are selectively processed to increase their brightness based on the reference signature 20 . In another embodiment, frames with brightness above a desired threshold are selectively processed to decrease their brightness based on the reference signature 20 . In yet another embodiment, only those frames above and/or below desired brightness thresholds are recorded. In this manner, those portions of a video stream having the desired brightness characteristics are recorded. As will be appreciated, contrast, sharpness, and/or other discernible visual characteristics may be the basis for (and discernible using) the reference signature 20 , so that selective processing and/or recording can be performed based on a variety of visual characteristics of the frames of a video stream. The reference signatures 20 thereby generated, along with the associated processing and/or recording instruction, are used to generate an action plan 24 that enables the automatic processing of a video stream, as discussed below. As discussed with regard to FIG. 1 , in one embodiment, metadata 26 is also associated with the action plan 24 of FIG. 2 , such as to provide textual, numeric and/or audio annotations of a video file produced in accordance with the action plan 24 or of the constituents of such a video file.
[0022] As described in FIGS. 1 and 2 , different embodiments of the present invention result in the generation of action plans 24 in which one or more reference signatures 20 and associated actions 22 are related. Referring now to FIG. 3 , a flowchart is provided depicting an embodiment of the present invention in which the action plans 24 are used to process a video stream 10 . In this embodiment, a comparison signature 36 is generated (block 34 ), for a current frame of the video stream 10 using a signature-generating algorithm. In this embodiment, the signature-generating algorithm is the same algorithm employed to generate the reference signatures 20 contained within the action plan 24 .
[0023] In the depicted embodiment, each comparison signature 36 is compared to the reference signatures contained in the action plan 24 (block 38 ). If the comparison signature 36 matches a reference signature of the action plan 24 , as determined at decision block 40 , the action corresponding to the matched reference signature is performed (block 42 ). For example, the corresponding action may be to record the current frame and/or subsequent frames, to cease recording, and/or to enhance or filter the current and/or subsequent frames, as discussed above. At decision block 44 , a determination is made whether the current frame was the last frame of the video stream 10 . If additional footage remains, processing proceeds to the next frame (block 46 ), and a new comparison signature 36 is generated. Conversely, if it is determined at decision block 44 that the end of the video file 10 has been reached, recorded and/or enhanced video segments or frames are compiled to generate a video file 50 (block 48 ). The compiled video file 50 may be in a raw format, consisting simply of recorded video frames, or it may be in a standardized and compressed format, such as an audio/video interleave (AVI) format or a moving pictures experts group (MPEG) video file format. In one embodiment, the format of the video file 50 enables the storage of metadata, such as textual descriptions of individual frames or sequences of frames. In such embodiment, metadata is provided by the operator and/or by the action plan 24 , and is associated with the appropriate video segments or with the video file as a whole (block 52 ).
[0024] The preceding aspects of embodiments of the present invention may be implemented in a variety of manners. For example, in one implementation, a computer, configured with a suitable processor, memory, input device, and display, executes software routines implementing some or all of the aforementioned functionality(ies). In another implementation, a video adapter for use in a computer or other electronic device implements some or all of the previously described functionality(ies), such as via dedicated circuitry and/or software routines. In such implementation, the video adapter includes a video processor, video memory, and/or display circuitry. In an additional embodiment, a consumer electronic device, such as a combination VCR and DVD player/writer includes a processor, memory, and display circuitry configured to implement, either by dedicated circuitry and/or software routines, the previously described functionality(ies). As will be appreciated by one of ordinary skill in the art, these embodiments are merely exemplary, and in no way exhaustively describe the array of electronic devices capable of implementing the above-described processes, in part or in their entirety. With this in mind, the following exemplary embodiments generally describe the various components and circuitry that may be employed.
[0025] For example, referring now to FIG. 4 , a block diagram depicting an exemplary processor-based device, generally designated by the reference numeral 70 , is illustrated. The device 70 may be any one of a variety of different types, such as a computer, a control circuit, a circuit board, a VCR/DVD conversion system, a DVR/DVD conversion system, a video archiving system, etc. In the depicted embodiment, the device 70 communicates with an input device 72 by which a user interacts with the device 70 . The input device 72 can be a remote control, a mouse, a keyboard, a console user interface including buttons and/or switches, and so forth and may communicate with the device via a wire or wireless medium. The input device 72 enables a user to control the acquisition of frames of a video stream and/or to provide associated actions for selected frames or reference signatures, as described below.
[0026] The depicted embodiment also includes a display 74 coupled to display circuitry 76 of the device 70 . Examples of a suitable display 74 include a liquid crystal display (LCD), a cathode ray tube (CRT), a plasma display, and so forth. The display 74 , via the display circuitry 76 , visually depicts a video stream for review by a user. The video stream may be acquired from one or more video input mechanisms 78 . One example of such a video input mechanism is a memory reader 80 , such as a reader configured to read an optical or magnetic medium or a solid state-based memory device. In one embodiment, the memory reader 80 is an optical media reader configured to read a DVD, a compact disk (CD), a laser disc, or other optical media, such as a holographic memory. In another embodiment, the memory reader 80 is a magnetic media reader, such as an analog or digital video tape player or a fixed or removable hard disk drive. Similarly, in other embodiments, the memory reader 80 is a device configured to access and read a solid state memory device such as a universal serial bus (USB) pen drive, a secure digital (SD) card, or other memory incorporating solid state memory circuitry. An additional example of a video input mechanism 78 is a network interface 84 used to download or receive a video stream (via a wire or wireless connection) from a network, such as the Internet, a local area network (LAN), a storage area network (SAN), etc. Similarly, in another example the video input mechanism 78 is a signal receiver 82 , such as a television (TV) tuner, configured to receive a television or other video signal via a cable TV connection, antenna, satellite receiver, or other receiver configured to acquire over the air video transmissions.
[0027] Continuing with the embodiment of FIG. 4 , the video stream acquired by the video input mechanism 78 is displayed on the display 74 by the display circuitry 76 . While the stream is displayed, reference frames may be identified, such as by an operator employing the input device 72 . The frame acquisition and processing circuitry 86 , when prompted via the input device 72 , acquires a currently displayed frame of the video stream. In one implementation, the acquired frame is then processed by a signature generator 88 to generate a reference signature, as discussed above. In one embodiment, the signature generator 88 is a specialized circuit configured to implement a signature-generating algorithm, either by hardware design, software implementation, or a combination of these techniques. In another embodiment, the signature generator 88 is a general processor, such as a central processing unit (CPU) or video processor of a video adapter, implementing a signature-generating algorithm.
[0028] The reference signature generated by the signature generator 88 is stored on a memory medium 90 . For example, in some embodiments, the reference signature is stored on the memory medium 90 for subsequent review or for incorporation into an action plan. In other embodiments, the reference signature is incorporated into an action plan that is stored on the memory medium 90 . In the depicted embodiment, the memory medium 90 is any type of medium that may be written to/read by the frame acquisition and processing circuitry 86 and signature generator 88 . For example, in one implementation, the memory medium 90 is a hard drive, such as may be present in a DVR or computer. In another implementation the memory medium 90 is random access memory (RAM), such as may be present in a computer, on a video adapter, or in other processor-based systems and consumer electronic devices. In one embodiment, the memory medium 90 stores frames acquired by the frame acquisition and processing circuitry 86 for subsequent retrieval and processing by the signature generator 88 . In this embodiment, therefore, the memory medium 90 stores acquired frames as well as generated reference signatures. As will be appreciated by those of ordinary skill in the art, the memory medium 90 may be local to or remote from other components of the device 70 . For example, the memory medium 90 be within a computer or consumer electronic device or may be external to but in communication with (such as over a network) a computer or consumer electronic device housing some or all of the other components.
[0029] The device 70 of FIG. 4 is suitable for generating a reference signature and action plan. For the purpose of illustration, FIG. 5 depicts an exemplary processor-based device 100 capable of processing a video stream based on an action plan and/or reference signatures such as may be generated by device 70 of FIG. 4 . Similar components in FIGS. 4 and 5 are depicted using the corresponding reference numbers discussed above with regard to FIG. 4 . As will be appreciated by those of ordinary skill in the art, the functionalities provided by the respective processor-based devices 70 and 100 may be implemented in one device, such as a computer or consumer electronic device, or in separate devices.
[0030] Referring now to FIG. 5 , a video input mechanism 78 , such as the memory reader 80 , signal receiver 82 , or network interface 84 discussed above, provides a video stream to frame acquisition and processing circuitry 86 . In one embodiment, a signature generator 88 processes the frames sequentially acquired by the frame acquisition circuitry to generate a comparison signature for each frame. Comparison circuitry 104 compares each comparison signature to the reference signatures of an action plan stored on a memory medium 90 . In one embodiment, the comparison circuitry 104 is a specialized circuit configured to compare the signatures, either by hardware design, software implementation, or a combination of these techniques. In another embodiment, the comparison circuitry 104 is a general processor, such as a central processing unit (CPU) or video processor of a video adapter, implementing a comparison routine.
[0031] Based upon the comparison, the frame acquisition and processing circuitry 86 may be instructed to begin a recording operation, to terminate a recording operation, to filter or to otherwise process acquired frames, and so forth. Frames acquired or processed in response to these instructions may be written to the memory medium 90 . In one embodiment, frames written to the memory medium 90 are compiled, either on-the-fly or after completion of the video stream, by a video compiler 106 to generate a video file. In one embodiment, the video compiler 106 is a specialized circuit configured to compile acquired frames into a desired compressed or uncompressed video format, either by hardware design, software implementation, or a combination of these techniques. In another embodiment, the video compiler 106 is a general processor, such as a central processing unit (CPU) or video processor of a video adapter, implementing a compilation routine.
[0032] In one embodiment, a video file generated by the video compiler 106 is stored, temporarily or permanently, on the memory medium 90 . In another embodiment, the compiled video file is written to a suitable media by a media writer 108 , such as a magnetic media writer, an optical media writer, or a device configured to write to a solid state memory medium (such as a USB pen drive or SD card). For example, a suitable magnetic media writer is a tape drive configured to write to analog or digital video tape, a floppy drive, a hard drive, and so forth. Similarly, a suitable optical media writer is a DVD burner, a CD burner, and so forth. As will be appreciated by one of ordinary skill in the art, the functionality of a respective optical media reader and optical media writer or of a respective magnetic media reader and magnetic media writer may be combined in a single drive or interface, such as a DVD read/write drive, a video tape player/recorder, a hard drive, and so forth.
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Methods for processing a video stream are provided. One embodiment comprises generating a comparison signature for a frame of a video stream and comparing the comparison signature to a reference signature. In another embodiment, a method comprises generating a reference signature for a frame of a video stream and assigning an action to the frame containing the reference signature. Example system embodiments for implementing the aforementioned methods are also provided.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Application No. 60/982,215 filed on Oct. 24, 2007 in the United States Patent Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a filter and power supply system, and more particularly a filter that can be connected to AC powered devices, wherein the filter can be easily interchanged.
[0004] 2. Description of the Related Art
[0005] Industry has been using AC powered devices which suffer performance degradation that is caused from noise that is present on the mains power circuit. Devices powered from the mains power circuit can generate noise that is then distributed onto the mains power circuit.
[0006] The power conversion devices in the related art do not allow for selection of specified noise frequencies that affect performance of the supplied products. For e.g. in an audio system, data modem or television, the magnitude of noise on the analog signals detrimentally affects performance. These power conversion devices are not designed to prevent generating noise due to the distance between devices and are not configurable to achieve the highest performance possible.
[0007] Currently, device filters contained within the devices are not removable. Accordingly, if a device receives power line interference, there is no easy way of eliminating that noise unless a filter is built into the system. Additionally, the cost of adding filters to each device for possible use is prohibitively expensive. Accordingly, a fault in a filter can not be easily fixed. Rather, due to a faulty filter, the performance of the whole device is affected requiring replacement of the whole device leading to a large cost. Additionally, these device can not be easily modified as the functions of the filters can not be easily altered.
SUMMARY OF THE INVENTION
[0008] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the related art, and an aspect of the present invention is to provide a filter that can be connected to AC powered devices, wherein the filter can be easily interchanged to improve performance of AC devices.
[0009] Additional advantages, aspects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
[0010] The power supply system includes a filter with at least a first and second connector, wherein the first connector is connected to a power source and the second connector is connected to power supply.
[0011] In another aspect of the present invention, at least one of the filter connectors is a female connector.
[0012] In another aspect of the present invention, the second connector is connected to the power supply by a cable.
[0013] In another aspect of the present invention, the second connector fits in a connector in the power supply.
[0014] In another aspect of the present invention, the power supply is a switched-mode power supply.
[0015] In another aspect of the present invention, a power supply system includes a first filter with at least a first and second connector, a second filter with at least a third and fourth connector, wherein the first connector is connected to a power source, wherein the first filter is connected to the second filter, and the fourth connector is connected to a power supply.
[0016] In another aspect of the present invention, the first filter is connected to the second filter by the second and third connectors.
[0017] In another aspect of the present invention, the first filter is connected to the second filter by a cable.
[0018] In another aspect of the present invention, the first filter and the second filter have different characteristics.
[0019] In another aspect of the present invention, one of the first and second filters negates only high frequency noise and the other of the first and second filters negates only low frequency noise.
[0020] In another aspect of the present invention, a filter includes a housing, a male connector, and a female connector.
[0021] In another aspect of the present invention, the male connector can be connected to an AC power source and the female connector can be connected to power supply.
[0022] In another aspect of the present invention, the filter further includes a breaker.
[0023] In another aspect of the present invention, the female connector is a C13 connector and the male connector is a C14 connector.
[0024] In another aspect of the present invention, a filter includes a first filter with a housing, a male connector, and a female connector, and a second filter includes a housing, a male connector, and a female connector, wherein the male connector of the first filter can be connected to the female connector of said second filter.
[0025] In another aspect of the present invention, the female connectors are C13 connectors and the male connectors are C14 connectors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The above and other objects, features and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0027] FIG. 1 illustrates the components of a power supply system according to an exemplary embodiment of the present invention
[0028] FIGS. 2-6 illustrate various exemplary embodiments with varying configurations based on the system illustrated in FIG. 1 ;
[0029] FIGS. 7-8 illustrate the filter and its wiring on the inside accordingly to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0030] Advantages and features of the present invention and methods of accomplishing the same may be understood more readily by reference to the following detailed description of the exemplary embodiments and the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification.
[0031] FIG. 1 is a an illustration of a power device system 1 according to an exemplary embodiment of the present invention. A modem connector/adapter 2 (although this embodiment is intended to connect to a modem, the embodiments are not limited to connections to modem) is connected to power supply, such as a switched-mode power supply (SMPS) 3 . An example of an SMPS 3 may have approximate dimension of 4.32″×1.970″×1.245″ with an input of 100-120 VAC 1.0 A 50-60 Hz and output 12.0 VDC 2.9 A. One of ordinary skill in the art would comprehend that the modem may be replaced by any other suitable device and the power supply may vary as well. The power supply has a male socket 7 . A connector 6 with female parts corresponding to the male socket 7 on the SMPS 3 can be input into the male socket 7 . The connector 6 is attached to a filter 8 . The filter 8 in this exemplary embodiment is a dual stage power line filter. The filter 8 also consists of a male socket 7 . An AC plug 4 provided with Mains AC Power is attached by way of a conductor 5 to a connector 6 . This connector 6 can be input in any male socket 7 . However, in FIG. 1 it is illustrated next to the male socket 7 of the filter 8 .
[0032] FIG. 1 further illustrates an inner connect auxiliary cable 10 which contains a male socket 7 and a connector 6 with female parts connected to each other with a conductor 5 . The inner connect auxiliary cable 10 may be used with any of the configurations presented below in FIG. 2-4 to provide flexibility in the arrangement and configuration. By way of example, in the Mains AC Powered Device 1 of FIG. 1 , the male socket 7 of the inner connect auxiliary cable 10 can be connected to the connector 6 of the filter 8 and the connector 6 of the inner connect auxiliary cable 10 is connected to the male socket 7 of the SMPS 3 . Accordingly, with the presence of the inner connect auxiliary cable 10 in the SMPS 3 and the filter 8 are connected electronically as they would have been if they were directly connected. This configuration of inner connect auxiliary cable 10 can be applied to anywhere where a male socket 7 and connector 6 are inter-connected.
[0033] FIG. 1 also illustrates an auxiliary power cable assembly 11 . The auxiliary power cable assembly 11 comprises of a male socket 7 and a AC receptacle 12 which corresponds to an AC plug 4 , connected by a conductor 5 .
[0034] FIGS. 2-6 illustrate various exemplary embodiments with varying configurations based on the system illustrated in FIG. 1
[0035] FIG. 2 illustrates an exemplary embodiment of the present invention in which no filter is used. FIG. 2 . illustrates a Mains AC Powered Device 1 which contains a modem connector 2 connected to SMPS 3 . The Mains AC Power 4 is connected to a connector 6 by mean of a conductor 5 . The connector 6 contains female parts and plugs into a corresponding male socket 7 in the SMPS 3 . Essentially, this configuration produces a standard power supply or appliance or device. The SMPS 3 is provided with an AC power by the Mains AC Power 4 by way of a removable connection based on the connector 6 .
[0036] FIG. 3 illustrates another exemplary embodiment of the present invention wherein a filter 8 is added to the configuration presented in FIG. 2 . Accordingly, a Mains AC powered device 1 which contains a modem connector 2 is connected to SMPS 3 . The Mains AC Power 4 is connected to a connector 6 by mean of a conductor 5 . The connector 6 contains and plugs into a corresponding male socket 7 of the filter 8 . Furthermore, a female connector 6 provided in the filter 8 plugs into corresponding male part 7 in the SMPS 3 . Essentially this configuration allows for addition of an inline power filter that uses the same AC cord that the switch mode power supply uses. Accordingly, by the use of the connector 6 on the filter 8 , the filter block can be directly plugged into an appliance, in this case a SMPS 3 . So all you a user has to do is take a filter 8 and plug it directly onto the appliance. The SMPS 3 is provided with an AC power by the Mains AC Power 4 by way of a removable connection based on the connector 6 .
[0037] FIG. 4 , displays another exemplary embodiment of the present invention. FIG. 4 , illustrates the solution for a scenario in which the configuration presented in FIG. 3 does not cure the problems with power line generated noise. Accordingly, there is a need for an additional filter. Therefore, additional filter 9 is serially added within the device. The connector 6 of filter 8 connects to male socket 7 of filter 9 , while the connector 6 of filter 9 connects to the male counterpart in SMPS 3 . Accordingly, a cascading of the noise filters is done leading to increase or doubling of the filtering capability.
[0038] One of ordinary skill in the art would comprehend that numerous filters could be added using the configuration and the methods illustrated above. Additionally, the plurality of filters that are used may have different characteristics of noise. By way of example, in FIG. 4 , filter 8 could be high frequency noise filter and filter 9 could be a low frequency noise. Accordingly, if both of these filter are used together, one would cancel the high frequency and the other would cancel the low frequency. Accordingly, a band-pass filter can be implemented. However, the filters are not limited to these characteristics and many different variations can be implemented based on the technical requirements.
[0039] Therefore, as illustrated by the exemplary embodiments provided above, the presence of the connectors 6 with female parts on the respective filters provides the flexibility to removably place the filter anywhere in the AC line. Accordingly, in another exemplary embodiment of the present invention (not illustrated), further filters can simply be cascaded using the methods and configuration described above allowing the filtering to be conducted in various methods. Essentially additional filters can be cascaded together to implement desired filtering. Accordingly, by a method of cascading multiple filter can be serially in line with the power cable or cord, power cord.
[0040] FIG. 5 illustrates the use of an inner connect auxiliary cable 10 according to another exemplary embodiment of the present invention. The male socket 7 of the inner connect auxiliary cable 10 is connected to the connector 6 of the filter 8 and the connector 6 of the inner connect auxiliary cable 10 is connected to the male socket 7 of the SMPS 3 . Accordingly, with the presence of the inner connect auxiliary cable 10 , the SMPS 3 and the filter 8 are electronically connected as they would have been if they were directly connected. This configuration of inner connect auxiliary cable 10 can be applied to anywhere where a male socket 7 and connector 6 are inter-connected. The use of the inner connect auxiliary cable 10 and especially the wire 6 , which might be a rubberized cord allows for further flexibility in the use of a filter 8 . By way of example, if the filter 8 is to be applied to a TV, it can simply be attached using a wire 6 , instead of the whole Mains AC Powered Device 1 having to be placed behind the TV.
[0041] FIG. 6 illustrates the use of auxiliary power cable assembly 11 according to another exemplary embodiment of the present invention. The male socket 7 of the auxiliary power cable assembly 11 is connected to the connector 6 of the filter 8 , while the AC receptacle 12 is connected to a AC plug 4 connected by a conductor 5 to a device 14 .
[0042] The configurations and methods applied to the filters with respect to the connectors 6 and the male sockets 7 in exemplary embodiments of the present invention can be used with varying type of filters and are not limited to the filters illustrated in the exemplary embodiments.
[0043] FIG. 7 illustrates an inside of the filter 8 and FIG. 8 illustrates a wiring diagram of the inside of a filter 8 accordingly to an exemplary embodiment of the present invention. The connector 6 , such as a C13 connector, and the male socket 7 , such as a C14 connector, are illustrated. The filter contains a non-conductive housing 21 on the outside. The filter further includes a breaker 20 . While the filter 8 does not necessary require a breaker 20 , it can be beneficial to put one in, so as to protect the circuits and minimize the chances of a fire.
[0044] Tables 1 and 2 below illustrate exemplary filter specifications of the filter used in an exemplary embodiment of the present invention.
[0000]
TABLE 1
FREQ (MHz)
.15
.5
1
10
30
Insertion Loss characteristics (50/50 Ohm)
@6 AMP
CM (dB)
30
50
60
60
60
DM (dB)
26
40
60
60
55
Insertion Loss characteristics (50/50 Ohm)
@10 AMP
CM (dB)
28
40
50
55
55
DM (dB)
26
38
55
60
60
Insertion Loss characteristics (50/50 Ohm)
@20 AMP
CM (dB)
18
35
45
50
58
DM (dB)
16
35
55
55
70
[0000]
TABLE 2
Insertion Loss characteristics (50/50 Ohm)
@1 AMP
FREQ (MHz)
.15
.5
1
10
30
CM (dB)
52
60
65
65
50
DM (dB)
28
45
65
65
55
Operating Frequency: DC - 60 Hz.
Operating Voltage: 250 V +10%.
Operating Current: 1 Amp (Ycap = 0, Leakage = 0 ma 120 V/60 Hz) [TBD]
Ambient temperature: 40 C. Climactic Catagory: 25/100/21.
Inrush Rating: 20 × (10 mS), 1.5 × (1.5 min).
Hipot Rating: 2200VDC Safety Approvals: cCSAus/UR/EN133200.
Weight: TBD
Physical Size: Approx 4.320″ × 1.970″ × 1.245″ (target size is same as SMPS).
[0045] One of ordinary skill in the art would comprehend that the structure can be slightly altered to implement the principles of the present invention to produce similar results.
[0046] In another exemplary embodiment (not illustrated) of the present invention, the device may have varying configurations and ground is isolated outside the device.
[0047] As described above, according to the exemplary embodiment of the present invention, filters can be interchangeably easily configured thus the performance of a power device can be easily improved.
[0048] Although exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. The foregoing embodiments are merely exemplary and are not to be construed as limiting the present invention. Therefore, the scope of the present invention should be defined by the accompanying claims and their legal equivalents.
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A power supply system with a filter with at least a first and second connector, wherein the first connector is connected to a power source and the second connector is connected to a power supply. A power supply system with a first filter with at least a first and second connector, a second filter with at least a third and fourth connector, wherein the first connector is connected to a power source, wherein the first filter is connected to the second filter, and the fourth connector is connected to a power supply. A filter with a housing, a male connector, and a female connector.
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RELATED INFORMATION
This is a divisional of application Ser. No. 08/801,129 filed on Feb. 14, 1997 now U.S. Pat. No. 5,972,020. The priority of this prior application is expressly claimed and their disclosure is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to the field of surgical instruments which are specially designed to facilitate surgery on the interior structures of the beating heart, in particular, the valves.
BACKGROUND OF THE INVENTION
For several decades, surgeons have been performing a wide variety of surgical procedures on the heart. The advent of cardiopulmonary bypass (CPB) allowed surgeons to stop the heart while maintaining a flow of oxygenated blood throughout the rest of the body such that lengthy and highly invasive surgical procedures on the heart could be performed. The CPB apparatus and procedure enabled more widespread practice of cardiac surgery by allowing surgeons to temporarily isolate the heart from the circulatory pathway while extensive and complex repair and reconstruction procedures were performed on the muscles, valves, arteries, etc. of the heart while the heart itself remained static. Although CPB provides the surgeon with the ability to perform certain procedures, connecting the patient to the CPB apparatus is time consuming and traumatic to the patient. In establishing CPB by traditional techniques, the chest is opened by cutting through the sternum and spreading the ribs, large bore cannulas are placed in the patient's venous and arterial system, the heart is stopped by infusion of chemicals, the aorta which supplies blood to the body from the heart is clamped shut, thus separating the heart from the rest of the circulatory system, and the patient's blood supply is circulated outside the body through a mechanical pump and a device to oxygenate the blood.
The CPB procedure has several well-known drawbacks and new information regarding the adverse effects of CPB is continually being discovered. For example, CPB runs the risk of causing ischemic/reperfusion injury in the heart and elsewhere in the body where blood flow is reduced or interrupted and restarted. The problem is particularly significant in the brain where peri-operative strokes and related neurological disorders have been observed in patients following CPB which may result from particles which cause interruptions in the blood supply to the brain. Also, the heart may sustain damage from the CPB process or from the CPB apparatus which results in reduced blood pumping capacity and other irregularities. Furthermore, damage to the blood itself results from passing the blood through the CPB pump and from surface interactions between the patient's blood and the synthetic surfaces inside the pump and associated apparatus. Due to the adverse effects of CPB, surgeons attempt to limit the amount of time that the patient is subjected to CPB and prefer to avoid CPB whenever possible.
Recently, to avoid the need for CPB, techniques and apparatus have been developed to enable surgeons to perform certain types of cardiac surgeries on the beating heart. Principal among these is coronary artery bypass graft surgery (CABG) wherein an obstructed coronary artery, which tends to be located at or near the surface of the exterior of the heart, is bypassed with another source artery or a graft to restore blood flow to the muscles of the heart beyond the obstruction. The prime rationale for the development of the beating-heart procedures is to avoid CPB, and surgeons and engineers are constantly searching for techniques and apparatus to expand the repertoire of beating-heart surgical procedures.
For surgical procedures involving structures and chambers internal to the heart, there is another important rationale for using a beating-heart approach. Many of these procedures require maintaining an opening through the epicardial and myocardial tissue to expose and allow access to the internal target area. An unavoidable result is the introduction of air into the chambers which must be removed to minimize the risk of air bubbles which can lead to stroke. The removal of air in these conventional procedures is accomplished after correcting the defect but prior to resuming normal heart-lung function by closing all myocardial incisions with the exception of a small opening or vent hole and massaging the heart to cause any entrapped air to escape through the opening. The opening is then sutured closed. This technique can be traumatic and damaging to the myocardium and the chambers, and especially to the newly treated target area. Moreover, there is no way of guaranteeing that all air is removed from the heart. Conversely, with a beating-heart approach, the introduction of air could be minimized as atmospheric exposure of the internal chambers must be limited to prevent the loss of blood. In addition, the patient's blood pressure would act to minimize the introduction of any air. Therefore, a need exists for instrumentation that would enable a beating-heart approach to surgical repair of internal cardiac structures while minimizing the risk of air entering the patient's circulatory system.
Surgical procedures involving the repair of structures inside the beating heart, such as the cardiac valves which control and regulate blood flow into, out of, and between the four chambers of the heart, the left and right atria and the left and right ventricles, are very difficult to perform. A surgical procedure on a heart valve is particularly difficult to perform on a beating heart because the valves are located inside the heart and continuously open and close to regulate the flow of blood. Moreover, the valves are immediately proximate to the atria and ventricles which continuously contract to cause blood to flow from the venous system, to the lungs to be oxygenated, and then throughout the body. Still further, the valves must control a volume of blood which may be under considerable pressure due to the contraction of the muscles of the heart. As such, it is extremely difficult to provide a bloodless field within which the surgeon has adequate visibility of the surgical area. Moreover, the continual opening and closing of a valve makes it difficult to perform delicate surgical tasks, such as suturing, which require a high degree of accuracy and precision.
Valve surgery on the beating heart is rendered even more problematic due to the substantial absence of special tools to enable surgical operations inside the beating heart. Among the difficulties inherent in beating heart valvular surgery are the need to work in a moving field, the need to prevent the flow of blood from obstructing the surgical field, and in the case of valvular surgery, the need to isolate a portion of the valve being repaired from the blood flow which is continuing in the remainder of the beating heart, and the need to allow the valves to continue to perform substantially their normal functions during the surgery. Thus, there is a substantial need for instrumentation and new surgical techniques for addressing these difficulties.
SUMMARY OF THE INVENTION
This invention includes specially designed instruments and methods for performing cardiac surgery on structures inside the heart while the heart continues to beat. The instrument provides the capability to isolate and substantially immobilize a portion of the internal cardiac tissue, such as the leaflet of a valve, while simultaneously providing an unobstructed and segregated surgical field in which the surgeon may operate to perform a surgical procedure.
Generally, the structure of the instrument is comprised of a body having a sealable portion of which all or a portion thereof is inserted into the beating heart to define a surgical field inside the beating heart and which isolates the surgical field from the blood flow. The segregated surgical field may be substantially contained within the interior of the beating heart and is defined by the design and structure of the instrument. The body of the instrument also has a sealable opening, preferably at a distal end, such that structures on the interior of the heart can be introduced through the opening and into the segregated surgical field within the beating heart. A movable sealing member conforms to the body of the instrument to provide a conformable gasket-like sealing means which provides a fluid impermeable seal between the interior of the beating heart and the segregated surgical field when a sealable opening therein is closed. The particular target structure of the heart on which the surgical procedure is to be performed, such as a valve leaflet, is introduced to the surgical field through the sealable opening in the body of the instrument. Substantially closing the scalable opening about the target structure creates a segregated surgical field where the target structure is inside the instrument and may be accessed by the surgeon. The instrument is used with, and may integrally contain, a vacuum suction aspirator or other device to evacuate blood and other fluids from the interior of the body of the instrument and the segregated surgical field once the sealable opening in the instrument is closed about the target cardiac structure. Once the surgical field is clear, the surgeon introduces additional surgical apparatus and instruments through the body of the instrument to perform the desired operation while the heart continues to beat.
DESCRIPTION OF THE FIGURES
FIG. 1 is the exterior of an embodiment of the invention which includes a substantially cylindrical body, a substantially planar sealing member, means for actuating and fixing the position of the sealing member, a handle for positioning the instrument and a light source and a vacuum aspirator introduced through the proximal end thereof.
FIG. 2 is a cross-section of the embodiment of FIG. 1 revealing the interior of the instrument of the invention and one possible configuration of a light source and vacuum aspirator located inside the body of the instrument.
FIG. 3 is a cross-section about line 3 — 3 in FIG. 2 above, revealing an interior configuration for the light source and vacuum aspirator.
FIG. 4 is a cross-section view of FIG. 2 above, showing the means for actuating and fixing the position of the sealing member passing outside the substantially cylindrical body of the device of the invention.
FIG. 5 is a close-up view of one configuration for a locking mechanism to fix the position of the sealing member in close engagement with the distal end, the body of the instrument.
FIG. 6 is a close-up view of the sealing member in the closed position to provide a fluid-impermeable seal at the distal end of the instrument.
FIG. 7 is a schematic outline of an additional embodiment of the instrument of the invention having a concave sealing member which provides an enlarged surgical field within the body of the instrument by extending the surgical field beneath the level of the sealed opening.
FIG. 8 is a cross-section of the embodiment of FIG. 7, showing one internal configuration for the light source, vacuum aspirator, and a means for adjustable positioning of the sealing member.
FIG. 9 is an isolated view of the distal portion of the embodiment of FIG. 7, showing the extended surgical field beneath the level of the sealed opening.
FIG. 10 is an additional embodiment of the invention having a movable handle and a configuration for the sealing member such that the entire structure thereof is displaced beneath the body of the instrument, and wherein a vacuum aspirator extends into the extended surgical field to remove fluids therefrom.
FIG. 11 is a cross-section of the embodiment of FIG. 10 showing one internal configuration for the vacuum aspirator, the light source, and an adjustable means for positioning the sealing member.
FIG. 12 is an isolated view of another configuration of the distal portion of the invention, showing an alternative closing mechanism for the sealing member.
FIG. 13 is a preferred configuration for the body of the instrument having the detachable upper section affixed to the proximal end of the instrument to expand the internal volume of the body of the instrument, and also having an alternate handle configuration.
FIG. 14 is a cross-section of the embodiment of FIG. 13 through line 14 — 14 showing more detail of the handle mechanism.
FIG. 15 is a cross-section of the embodiment of FIG. 13 through line 15 — 15 showing the extended diameter section of the embodiment.
FIG. 16 is an isolated view of one configuration of the distal portion of the invention, and in particular, a configuration for the sealing member.
FIG. 17 is a schematic view of a heart having the body portion of an embodiment of the invention operably positioned within the mitral valve.
FIG. 18 is cross-section of another embodiment of the present invention having a covered top portion with sealable tool ports.
DETAILED DESCRIPTION OF THE INVENTION
The following description may refer in particular to a procedure or a configuration of the apparatus particularly suited to valvular surgery, and may refer to valve surgery by example. However, the invention is also applicable to other structures and surgical procedures internal of the beating heart. The body of the instrument of the invention may take several different shapes, preferably however, the body is substantially cylindrical having the sealable opening at the bottom (distal) end thereof where the segregated surgical field is created by the sealing member engaging the lower end of the substantially cylindrical body enabling thereby the sealable opening to be brought into proximity with the region of the cardiac tissue proximate to the site of the surgery. The (distal) lower end of the body of the instrument provides a substantially sealed portion comprised of a sealable opening and a gasket-like sealing member to create the segregated surgical field internal to the beating heart. The upper (proximal) end of the body of one embodiment of the instrument is open such that surgical instruments and related apparatus are introduced to the segregated surgical field through the body of the instrument of the invention. Alternately, the upper portion of the body may be closed and have sealable ports therein for delivery of surgical instruments to the segregated surgical field.
The insertion of the device through the epicardial layers of the heart may be achieved through a sealable incision provided with a purse-string suture or suture cuff installed in the pericardium and myocardium. An incision is made of sufficient length to insert the sealed portion of the body of the instrument through the myocardium. Once inserted, the tissue surrounding the incision is quickly sealed around the outside of the body of the instrument, for example by the purse string, to prevent excessive loss of blood. Once the incision is sealed around the outside of the body of the instrument, the distal end of the instrument may be oriented to bring the sealable opening to the specific site of the surgery.
The sealable opening may be provided by a trap-like sealing member which seals against the body of the instrument when the sealable opening is substantially closed and which forms a seal with the body of the instrument and thereby surrounding the cardiac tissue proximate to the region where the procedure is to be performed. The positioning of the cardiac tissue within the segregated surgical field defined by the instrument may also be facilitated by passing a suture through the cardiac tissue and then drawing the suture through the body of the instrument and through the open end at the proximal end of the instrument. By exerting tension on the suture line, the tissue is more readily oriented into the sealable opening of the instrument, and thereby, into the segregated surgical field. Thus, by manipulation of the tissue and the instrument itself, a portion of cardiac tissue, such as a portion of a valve, may be introduced to the interior of the body of the instrument through the sealable opening and is maintained in a segregated surgical field.
By bringing the sealing member into close conformity with the body of the instrument, the sealable opening is substantially closed and a portion of cardiac tissue, such as the leaflet of a valve, is then isolated within the segregated surgical field and the segregated surgical field is in fluid isolation from the remainder of the beating heart. Substantial closure of the sealable opening followed by evacuation of fluids creates an unobstructed and segregated surgical field within the body of the instrument. The closure or sealing of the sealable member to the body of the instrument is said to be “substantial” because cardiac tissue may be disposed within the sealable opening and may provide a portion of the overall sealing function. An aspirator or equivalent suction or blower device may be introduced into the interior of the body of the instrument to keep the surgical field clear of fluids and may also contain other conventional surgical apparatus such as irrigators, lights, stitchers, clamps, suture needles, cameras, etc. If desired, the associated surgical apparatus such as aspirators and light sources may be integrally associated with the body of the instrument.
As noted above, the body of the instrument may be substantially cylindrical and may be a unitary structure or may be comprised of independent sections which are added or removed based on the clinical circumstances attendant to the surgery. For example, in a procedure where the sealable opening is positioned within the heart in a region with a volume of blood under high pressure, blood may rapidly fill the interior of the body of the instrument and can overflow. In such circumstances, the body of the instrument may have an extension which preferably attaches to the proximal end to increase the internal volume of the instrument and to permit containment of a larger volume of blood. The depth of the instrument and the resulting pressure head developed balance the pressure of blood within the cardiac chamber into which the instrument has been inserted. Depending on the type of surgical procedure, the targeted surgical structure, the size of the heart chamber being worked on, and the anatomy of the particular patient, the volume of the instrument of the present invention is chosen to accommodate a requisite depth of blood to minimize the risk of overflow.
Alternately, the body of the instrument may have a covered or closed proximal end whereby the risk of overflow is obviated. In this embodiment, small sealable ports or holes are provided through the closed proximal end for delivery of surgical tools, scopes, clear fluid, and the like.
In the mitral valve surgery example, the instrument is inserted through the exterior of the heart to be brought into proximity with the site of the surgery at the interior of the heart, such as the mitral valve, where the surgeon will often repair damage to the individual leaflets which form the valve. By manipulating the instrument of the invention, the surgeon may introduce the leaflet into the sealable opening of the instrument and bring the sealable member into a position which conforms the sealable member with the body of the instrument such that the opening is sealed and the valve leaflet is positioned within the segregated surgical field. In such a configuration, the remaining leaflets of the valve will abut the exterior of the sealed portion of the body of the instrument while the heart continues to beat. Depending on the location of the surgery within the beating heart, the exterior of the heart, i.e., the pericardium and myocardium, may be closed around the exterior of the body of the instrument, such as by a clamp or purse-string suture, to avoid blood loss and the introduction of air into the patient's circulatory system. The surgeon can freely position the instrument by manipulating a handle which is preferably affixed to an upper (proximal) portion of the body of the instrument.
As noted, the use of the device is advantageous in that an unobstructed and segregated surgical field is defined inside the beating heart. This field may be separately irrigated, ventilated, or exposed to other chemical or physical agents, manipulations or treatments, separate from the remainder of the heart and separate from the circulatory pathway for the remainder of the body. If the access to the beating heart is provided by a less invasive procedure, i.e., a mini-thoracotomy rather than traditional “open heart” techniques, the body of the instrument should have a length sufficient to introduce the sealed portion of the body of the instrument to the interior of the beating heart by passing between the ribs and through the closed chest cavity. In this case, the instrument preferably has a substantially cylindrical body of a sufficient length to reach all of the internal structures of the heart while the positioning of the device is achieved by manipulating the handle from outside the chest cavity. In such a configuration, the sealed portion of the instrument may be the entire length of the body of the instrument which is inserted into the chest cavity. In each embodiment, all exterior surfaces of the instrument are preferably smooth to avoid damage to the heart and surrounding tissues when the instrument is inserted and removed.
Once the instrument of the invention is in proximity to the site of the surgery, the cardiac tissue is introduced through the sealable opening as described above and the sealable opening is effectively sealed by manipulating the sealing member into an orientation necessary to prevent the flow of blood into the segregated surgical field. The sealing member can be provided in several shapes, depending on the shape of the body of the instrument, and can be oriented by remote manipulation. In one embodiment, the sealing member is a substantially planar “trap”-like structure positioned at the most distal portion of the body of the instrument. The sealing member may move independently of the body of the instrument or may move about a pivot located at one edge of the periphery of the circumference of the body of the instrument. A means for positioning the sealing member is provided, for example, by a vertical rod which has one end affixed to the sealing member appositive the pivot. The sealing member may be actuated by vertical movement of a rod or shaft. By moving the shaft upward, the sealing means contacts the tissue disposed within the opening and forms a seal surrounding the tissue to prevent fluid from entering the segregated surgical field within the sealed portion of the body of the instrument. Once the sealing member is properly positioned, the sealing member can be fixed in place by a locking mechanism, thumbnut, or other such conventional mechanism.
The seal between the sealing member and the body of the instrument is provided by a soft conformable material which covers all or substantially all of the entire area of contact between the sealable member and the body of the instrument. For example, with a cylindrical embodiment, the conformable material covers the annular edge at the bottom of the sealed portion of the body of the instrument and the annular edge of the sealing member such that when the sealing member is brought in proximity with the body of the instrument, with a portion of tissue disposed therebetween, the sealable opening is substantially closed and the conformable material contacts both of the upper and lower surfaces of the tissue to form a fluid impervious seal between the interior of the instrument and the interior of the beating heart. At any space where tissue is not disposed therebetween, the conformable material of the sealed portion of the body and the sealing member respectively are in direct contact with each other to provide the complete seal required to keep fluid from entering the segregated surgical field.
The precise dimensions of the instrument may be varied depending on the particular design and application of the instrument. Preferably, the instrument has a height of approximately 90 mm (3.5 inches) or less, has an external diameter of approximately 30 mm (1.2 inches) at the distal end and approximately 40 mm (1.6 inches) at the proximal end. The inner diameter of the body 1 of the instrument may be approximately 27 mm (1 inch).
Referring now to the drawings, wherein like reference numbers indicated like elements, and in particular to the embodiment of the invention of FIG. 1, the body of the instrument 1 is sealed along its entire length and has a movable sealing member 2 at the distal end of the body 1 . Movement of a sealing member 2 is achieved by manipulation of a means for positioning the sealing member comprising a movable rod 3 which, in this example, orients the sealing member 2 about a pivot 4 affixed to the periphery of the distal end of the body 1 of the instrument. The angle created between sealing member 2 and the edge 18 of the distal end of the body of instrument 1 may be approximately 35° when sealing member 2 is in an open position, but may be more or less depending on the dimensions of the target cardiac tissue. The size or angle of sealable opening 6 need only be large enough to accommodate the target cardiac tissue therein. The side of edge 18 opposite pivot 4 is angled slightly downward from the body to maximize the draining of blood via fluid communication port 9 .
The upper surface of the sealing member 2 , which abuts the body 1 of the instrument and which contacts the cardiac tissue, has a conformable sealing means 5 placed about the periphery thereof. Conformable sealing means 5 may cover the entire upper surface of the sealing member 2 or may cover a substantial portion of the periphery thereof. Conformable sealing means 5 may have a uniform thickness or may be tapered along its length to achieve the best seal when sealing member 2 is closed.
The proximal end of the instrument may have a handle 11 which may be permanently attached to the body 1 of the instrument or may be removable. Handle 11 is preferably rotatable about the body 1 of the instrument and is shaped to be held by the hand. For maximum freedom of movement, handle 11 may be rotatable about the complete axis of the body 1 of the instrument. Handle 11 is used to position the instrument when it is introduced to the beating heart, i.e., through a sternotomy or thoracotomy, and particularly when the instrument is introduced to the interior of the beating heart.
Referring to FIG. 2, one possible arrangement for certain elements of the device of the invention is shown in a cross-sectional view of the device. In this embodiment, the means for positioning the sealing member, such as movable rod 3 is substantially external to the body of the instrument as shown in FIG. 1 . The movable rod 3 may be contained within a separate housing 13 mounted on the exterior of the body 1 of the instrument or may run through the interior of the body 1 of the instrument (not shown) and still be affixed to the sealing member 2 . The uppermost end of the movable rod 3 may have a locking mechanism 7 to fix the position of the movable rod 3 so that the position of the sealing member 2 relative to the body 1 of the instrument can be fixed when the sealable opening 6 is substantially closed.
The locking mechanisms of FIGS. 1 and 2 may be an elbow 15 at the uppermost portion of the movable rod 3 which abuts a latch 12 which has a flat section 14 shaped to contact the elbow 15 at the uppermost portion of the movable rod 3 . Several alternative mechanical designs for the locking mechanism may be readily provided. For example, a thumb screw or nut at the uppermost portion of the movable rod 3 allows continuous lockable positioning of the movable rod 3 and continuous positioning of the sealing member 2 (See FIGS. 7 and 10 ).
The embodiment of FIG. 2 has a fluid evacuation means 8 comprising a vacuum aspirator integrally associated with the body 1 of the instrument and having an air communication pathway 9 running from the upper portion of the body 1 of the instrument to the distal end adjacent the sealable opening 6 . The fluid evacuation means 8 need not be integral with the body of the instrument and may be provided during the surgical procedure by a conventional suction apparatus. However, it is preferred that the fluid evacuation means 8 be continuously operated within the instrument during the procedure so that fluids can be continuously removed from the segregated surgical field. The interior of the body 1 of the instrument may also be provided with a light source and/or an endoscope 10 to illuminate and provide viewing of the segregated surgical field. As with the fluid evacuation means 8 , the light source or scope 10 may be integral to the body 1 of the instrument or may be separately introduced through the body 1 of the instrument through the open end.
FIG. 3 is a cross-section through line 3 — 3 of FIG. 2 showing the internal space of the body 1 of the invention and one configuration for the air communication pathway 9 , light source and/or scope 10 , and movable rod 3 . In this embodiment, the movable rod 3 is partially contained within a separate housing 13 .
FIG. 4 is a cross-section of the embodiment of FIG. 2 through line 4 — 4 showing a configuration of the interior of the body of the invention at a more distal portion thereof. At the more distal portion, the movable rod is outside the body 1 having extended beyond the separate housing 13 .
FIG. 5 is an isolated view of the movable rod locking mechanism at the proximal portion of the invention. To lock the movable rod 3 in place, latch 12 is positioned such that a flat section 14 contacts an elbow 15 at the upper-most (most proximal) portion of the movable rod 3 . By bringing the flat section 14 of latch 12 and the elbow 15 into a locking relationship, as shown in FIG. 5, the position of the movable rod 3 is fixed, thereby fixing the position of the sealing member 2 relative to the body of the housing 1 by setting the downward position of movable rod 3 about pivot 4 .
Thus, as shown in FIG. 6, when the movable rod 3 is fixed in the most downward position, the sealing member 2 closes sealable opening 6 by engaging the distal portion of housing 1 . In this embodiment, the conformable sealing means 5 is affixed at least to the upper-most (proximal) portion of sealing member 2 and may also be affixed to the bottom surface of the distal portion of the body 1 .
FIG. 7 illustrates an additional configuration of one embodiment of the invention. The sealing member 2 in this embodiment is non-planar and may be concave at the interior surface 20 to provide an enlarged internal volume 17 for the segregated surgical field inside the body 1 of the instrument. This configuration provides the surgeon with the advantage of an extended segregated surgical field 17 and a working space below the level of the sealable opening 6 and, hence, below the level of the tissue positioned therein.
As with the embodiment of FIG. 2, this embodiment of the device of the invention is provided with a fluid evacuation means 8 , which is generally comprised of an air communication pathway 9 running from the upper portion of the body 1 to the distal end adjacent the sealable opening 6 . A light and/or viewing source 10 is also provided to illuminate and facilitate viewing of segregated surgical field 17 . In this embodiment, the movable shaft 3 is contained entirely within the body 1 of the instrument and is attached to the sealing member 2 at a point within the extended surgical field 17 . Various configurations for this attachment are contemplated, and include, for example, a link or loop-like protrusion 19 extending from surface 20 which can be grasped or engaged by a hooked or bent distal end 21 of rod 3 . As mentioned above, the positioning of the movable shaft 3 may be adjusted by a thumb screw 16 located at the proximal end of the body 1 of the instrument.
Referring to FIG. 8, a cross-section of the embodiment of FIG. 7 is shown about line 8 — 8 . The internal configuration of this embodiment is similar to that described previously, and has an air communication pathway 9 and a light source and/or viewing means 10 disposed therein. Note that the movable rod 3 is also located within the body 1 of the instrument.
In FIG. 9, an isolated view of the most distal portion of the embodiment of FIG. 7 is shown in a position where the sealable member 2 is closed. Thus, an extended surgical field 17 is provided below the level of the sealable opening 6 . In this configuration, the conformable sealing means 5 is attached to both the upper (proximal) portion of sealing member 2 and the lower (distal) portion of the body 1 .
Referring to FIG. 10, an additional configuration of the device of the invention is shown, having a movable handle 11 which can be lifted upwards (as shown in phantom) to accommodate positioning of instrument 1 at any depth when operably positioned within the chest cavity. As with the embodiments of FIGS. 2 and 7, this configuration also provides a fluid communication pathway 9 . However, in this embodiment, air communication pathway 9 terminates at a lever below the level of the sealable opening to provide a bloodless field below the level of tissue when positioned within surgical field 17 . FIG. 11 shows a cross-section through line 11 — 11 of FIG. 10, revealing the internal configuration of the embodiment of FIG. 10 wherein the scope means and/or light source 10 , movable shaft 3 , and air communication pathway 9 are placed in close proximity to one another to be as unobtrusive as possible during the surgery. The sealing member 2 has a configuration similar to that of FIG. 7 .
Referring to FIG. 12, another embodiment is shown wherein the sealable opening 6 is created such that the upper portion of the sealing member 2 and the lower portion of the body 1 are substantially parallel to each other when sealing member 2 is in an open position. As in the above embodiments, positioning of the sealing member 2 by a movable rod 3 seals the sealing member 2 against the body 1 at conformable sealing means 5 to close and seal the sealable opening 6 . However, in lieu of a hinged sealing member and a hooked rod and loop configuration, rod 3 of FIG. 12 is affixed to interior surface 20 by means, for example, of a solder connection 22 or other like means.
An enlarged detailed view of one embodiment of the sealing member 2 and associated sealing means 5 of the present invention is shown in FIG. 16 . Sealing means 5 is in the form of dual annular elements which are held within annular retaining grooves 46 . Sealing means 5 is made of highly compressible material such as silicone or other elastomer so as to be easily conformable to cardiac tissue around which it seals.
Referring now to FIG. 13, there is shown a preferred embodiment of the invention having a detachable upper section 23 which is sealingly engaged within the proximal end of body 1 , by means of an “o-ring” (not shown) positioned around the external diameter of the distal end of upper section 23 . This combined structure provides an expanded internal volume and height approximately double that of body 1 alone. Such an expanded internal volume provides containment of a larger volume of blood and prevents overflow during a beating-heart procedure. After blood has been removed by aspiration via fluid communication port 9 , detachable upper section 23 may be manually detached by an upward pulling or twisting motion. As such, the height or length of the instrument 1 is reduced by approximately half, facilitating the surgeon's access to and the delivery of surgical tools to the surgical area.
Upper section 23 and body 1 have substantially conical shapes, having diameters which narrow gradually, proximally to distally, with the distal end of upper section 23 having an outer diameter which allows it to be positioned within the proximal end of body 1 . As is more clearly shown in FIG. 15, which provides a cross-sectional view of FIG. 13 along line 15 — 15 , the outer wall 25 of body 1 has a thicker portion 25 a for accommodating various ports such as for a moveable rod 3 a (shown partially in phantom) for opening and closing hinged sealing member 2 , a fluid communication port 9 , and a port for delivery of a scope 10 which may extend partially internally and partially externally of body 1 . Here, the moveable rod comprises two sections, a section 3 a internal to body 1 and an external section 3 b which is coupled to section 3 a by means of a multidirectional u-joint 26 . U-joint 26 allows external section 3 b to be freely rotated and pivoted with respect to internal section 3 a while also controlling the position (opening and closing) of sealing member 2 . A knob 27 mounted at the proximal end of section 3 b provides easy manipulation, positioning, and locking of the rod sections. The passage of the rod 3 a , fluid lumen 9 , and light and scope 10 through the thickened section 25 a permit opening and closing of sealing member 2 , with and without upper section 23 attached to body 1 . This design provides smooth surfaces on the outside of body 1 to provide atraumatic passage through and sealing against tissue, and on the inside of body 1 to provide an uncluttered surgical field and to seal upper section 23 .
A handle 11 is mounted at the proximal end of body 1 or, when upper section 23 is in place, at the midsection of the combined structure. A lever arm 28 extends between handle 11 and a rotatable collar 24 which resides around the proximal end of body 1 and has tabbed ends 24 a and 24 b . Collar 24 is rotatable about the circumference of body 1 to position handle 11 for optimal access and working space for a surgeon. Lever arm 28 is connected to collar 24 at a joint 29 and to handle 11 by a moveable joint 30 which allow for further adjustment of the position of handle 11 . The position of collar 24 about body 1 , the position of lever arm 28 with respect to collar 24 , and the position of handle 11 with respect to lever arm 28 are all adjustable and locked in place by means of a wing nut 31 at moveable joint 30 . This three-way locking action is accomplished by the configuration of lever arm 28 .
As shown in FIG. 14, which is a view of the instrument of FIG. 13 along the line 14 — 14 , lever arm 28 comprises two elongated lengths 28 a and 28 b , 28 a having a threaded bore at its proximal end. The distal ends of lengths 28 a and 28 b are held together by threaded nut and bolt 32 (see FIG. 15 ), while the proximal ends are spaced apart. Thumbscrew 31 passes through the distal end of handle 11 and length 28 b such that when thumbscrew 31 is rotated, length 28 a is caused to compress against length 28 b and handle 11 , and thus, tighten joints 29 and 30 . Upon this action, the distal ends of lengths 28 a and 28 b are caused to pivot away from each other about a fulcrum point 33 . Extending from the distal end of length 28 b is a tapered section 34 positioned within tabbed end 24 b of collar 24 , such that tabbed end 24 b is caused to become wedged within tabbed end 24 b and compress against tabbed end 24 a when thumbscrew 31 is rotated, thereby tightening collar 24 around body 1 and locking handle 11 in a fixed position relative to body 1 . With such a configuration, multiple orientations of handle 11 may be achieved, thus optimizing viewing and access of the targeted surgical area. Although a single-step three-way locking mechanism has been described, it will be appreciated by those skilled in the art that other handle adjustment and locking mechanisms and configurations may be employed with the present invention.
FIG. 17 is a schematic representation of a cross-section of the distal portion of an embodiment of the present invention operably positioned within the mitral valve of a beating heart 40 . An incision is provided in the pericardial and myocardial layers of the heart 40 which has been temporarily sealed about the body 1 of the instrument with a purse-string suture 41 to prevent excess blood loss. One leaflet 42 of the mitral valve is positioned through the sealable opening and within the segregated surgical field. Conformable sealing member 5 creates a seal between the leaflet and the edge of body 1 and sealing member 2 . Blood entering the surgical field 27 can be aspirated via fluid communication tube 9 which passes the blood to outside the patient's body. Together the sealing and fluid aspiration functions of the present invention act to provide a substantially bloodless segregated surgical field and to substantially stabilize valve leaflet 42 . Surgical devices, such as scalpels, forceps, etc., may be introduced into the interior of body 1 to perform the necessary surgical repair. As the surgery is performed, the heart remains beating and the valve's other leaflet 43 continues its normal function to maintain blood flow through the space between sealing member 2 and valve leaflet 43 to the left ventricle 45 of heart 40 .
Another embodiment of the present invention is illustrated in FIG. 18 which obviates the need for an extended internal volume. Here, the body 1 has a covered proximal end 47 which prevents the overflow of blood. Multiple ports 48 are provided, however, through covered surface 47 for delivering surgical tools 49 (e.g., scalpel, scissors, scope, etc.) and the like to the surgical field. Each of tool delivery ports 48 is sealed closed when not occupied with a tool by means of a rubber seal 51 . Seal 51 further acts to seal a tool 49 within a port 48 to prevent seepage of blood. The configuration of sealing member 2 and movable rod 3 are similar to that of FIG. 12, however, a fluid communication port 9 is integral with rod 3 to evacuate the blood. A venting port 50 is provided so as to equalize the pressure within body 1 when aspiration is taking place. Alternately, port 50 may be used for fluid delivery or injection, for example, to deliver a saline solution to provide a clear viewing space within body 1 .
The particular examples set forth herein are instructional and should not be interpreted as limitations on the applications to which those of ordinary skill are able to apply this invention. Modifications and other uses are available to those skilled in the art which are encompassed within the spirit of the invention as defined by the scope of the following claims.
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The invention is a method to perform a surgical procedure within the beating heart. The instrument provides a seal to surround cardiac tissue, thereby defining a segregated surgical field within the body of the instrument. A suction device is preferred to remove blood and fluids from the surgical field so that a surgical procedure can be performed while the heart continues to beat. The instrument is particularly suitable for a procedure to repair defective or diseased cardiac valves, such as the mitral valve; a procedure which previously required that the heart be stopped so that the corrective surgical procedure could be performed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The instant invention relates to a fibrous filter media comprising a web of thermoplastic fibers, wherein said thermoplastic fibers have been surface modified with a gaseous plasma at atmospheric conditions. The instant invention also relates to methods to generate said fibrous filter media.
[0003] 2. Description of Related Art
[0004] The filtration properties of nonwoven polymeric fibrous webs can be improved by transforming the web into an electret, i.e., a dielectric material exhibiting a quasi-permanent electrical charge. The electrostatic charge provides for increased filter efficiency against a variety of substances, especially charged particulates such as dust. Electrets are effective in enhancing particle capture in aerosol filters. Electrets are useful in a variety of devices including, e.g., air filters, face masks, and respirators, and as electrostatic elements in electro-acoustic devices such as microphones, headphones, and electrostatic recorders. Charged filters are commonly used today in household heating and air conditioning filters, in vacuum bags, and for other uses.
[0005] Filtration webs can be formed by a variety of methods. For example, a thin film or monolayer of polymer material can be extruded and charged via corona discharge. The charged film is then fibrillated and the resulting fibrils formed into a non-woven web via needle punching or other known means. In another method, a polymer is melt blown as a fine fiber and then fashioned into a non-woven web. The fibers are charged either as they exit the orifice of the extruder during melt blowing or after they are assembled into a web. Charging can be carried out by corona exposure, ion bombardment, etc. Electrets are currently produced by a variety of methods including direct current (“DC”) corona charging (see, e.g., U.S. Pat. Re. 30,782 (van Turnhout)), and hydrocharging (see, e.g., U.S. Pat. No. 5,496,507 (Angadjivand et al.)), and can be improved by incorporating fluorochemicals into the melt used to produce the fibers of some electrets (see, e.g., U.S. Pat. No. 5,025,052 (Crater et al.)).
[0006] Many of the particles and contaminants with which electret filters come into contact interfere with the filtering capabilities of the webs. Liquid aerosols, for example, particularly oily aerosols, tend to cause electret filters to lose their electret enhanced filtering efficiency (see, e.g., U.S. Pat. No. 5,411,576 (Jones et al.)).
[0007] Numerous methods have been developed to compensate for loss of filtering efficiency. One method includes increasing the amount of the nonwoven polymeric web in the electret filter by adding layers of webs or increasing the thickness of the electret filter. The additional web, however, increases the breathing resistance of the electret filter, adds weight and bulk to the electret filter, and increases the cost of the electret filter. Another method for improving an electret filter's resistance to oily aerosols includes forming the electret filter from resins that include melt processable fluorochemical additives such as fluorochemical oxazolidinones, fluorochemical piperazines, and perfluorinated alkanes. (See, e.g., U.S. Pat. No. 5,025,052 (Crater et al.)). The fluorochemicals should be melt processable, i.e., suffer substantially no degradation under the melt processing conditions used to form the microfibers that are used in the fibrous webs of some electrets. (See, e.g., WO 97/07272 (Minnesota Mining and Manufacturing)). U.S. Pat. No. 6,419,871 (Ogale) discloses an electrostatic filter medium comprising a web of electret fibers which have been treated with fluorine-containing plasmas to produce fibers that are electrostatically charged. The fibers in U.S. Pat. No. 6,419,871 are subsequently rinsed and dried. However, U.S. Pat. No. 6,419,871 suffers from the drawbacks of having to use a chamber at reduced pressure wherein the pressure used is on the order of 1× 10 −2 to 1.0 Torr. Because the plasma treatment is performed at reduced pressure (also called vacuum plasma treatment), one is limited by the size of the chamber that can be used. U.S. Pat. No. 6,419,871 is herein incorporated by reference in its entirety.
[0008] The inventor of the instant invention has found that he is able to address some of these drawbacks. Thus, the instant invention discloses improvements that further enhance the filtration properties of polymeric fibrous webs and electrolets.
[0009] 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 SEVERAL VIEWS OF THE DRAWINGS
[0010] 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:
[0011] FIG. 1 is a 2500 fold magnification of 1 micron poly(butylene-terephthalate) fibers;
[0012] FIG. 2 is a 500 fold magnification of 1 micron poly(butylene-terephthalate) fibers;
[0013] FIG. 3 is a 10,000 fold magnification of 1 micron poly(butylene-terephthalate) fibers;
[0014] FIG. 4 is a 50,000 fold magnification of untreated polypropylene fibers;
[0015] FIG. 5 is a 30,000 fold magnification of untreated polypropylene fibers;
[0016] FIG. 6 is a 10,000 fold magnification of 1 micron poly(butylene-terephthalate) fibers;
[0017] FIG. 7 is a 2,500 fold magnification of untreated polypropylene fibers;
[0018] FIG. 8 is a 50,000 fold magnification of atmospheric plasma treated fibers;
[0019] FIG. 9 is a 30,000 fold magnification of atmospheric plasma treated fibers;
[0020] FIG. 10 is a 10,000 fold magnification of atmospheric plasma treated fibers;
[0021] FIG. 11 is a 5,050 fold magnification of atmospheric plasma treated fibers;
[0022] FIG. 12 is a 2,500 fold magnification of atmospheric plasma treated fibers; and
[0023] FIG. 13 provides a comparison of the % Efficiency between the raw material, plasma treated material, plasma treated material that is also charged, plasma treated material that has been soaked in isopropyl alcohol, and plasma treated material that is charged and also soaked in isopropyl alcohol.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present inventor has found that by modifying the surface of microfibers by surface treatment with an atmospheric plasma process, improved filtration occurs. Moreover, the use of atmospheric plasma conditions means that a reduced pressure chamber is not required for plasma treatment leading to decreased costs and the ability to treat greater amounts of microfibers. Atmospheric plasma treatment has an advantage over corona treated surfaces in that atmospheric plasma treated surfaces hold their treatment longer. The atmospheric plasma treating process also allows the treatment of microfibers without being restricted by both the size of chambers and the reduced pressure needed in reduced pressure plasma treatment equipment.
[0025] Atmospheric plasma treatment of microfibers likely leads to improved filtration ability due to one or more of the following: etching the surface, the cleaning of the surface, deposition of chemicals, oxidation or reduction of the surface, or the efficient formation of free radicals on the surface generating the possibility of intermolecular cross-linking (carbonization).
[0026] In the etching process, it is likely that the etching exposes internally melted additives such as activated carbon, colorants, and other possible additives that further aid in filtration. The increased surface area can enhance filtration properties by post charging of the media through conventional electret charging equipment.
[0027] As an alternative mechanism, it is likely that cleaning the surface removes oily residues from the surface of the microfibers allowing better filtration by exposing the surface to the particles to be filtered.
[0028] The process may also increase the amount of additives from the interior at the surface of these microfibers. Additionally or alternatively, the instant invention allows more surface area exposed per weight than does previously disclosed methods, all of which improves the filtration process.
[0029] Irrespective of the mechanism, the net result of the instant invention is that there is an increased surface area of the fibers available for filtration allowing more “sights” or area for particle entrapment, thus, leading to a more effective filter.
[0030] The instant invention also does not require the higher ratio of additives of previous methods yet it is still effective at filtering the desired particles, Thus, the instant method has decreased costs. Further, the higher ratio of additives used in the prior art experienced problems associated with fiber processing that could not be overcome by machine adjustments. Because the instant method does not require a higher ratio of additives it does not suffer from the problems encountered in fiber processing.
[0031] Further, currently available equipment to make meltblown fibers have physical limitations that prevent the manufacture of fibers that are consistently less than 1 micron in size. Because the instant method provides a microfiber that has improved filtration ability, there is less reliance on manufacturing fibers that are all uniformly small in size.
[0032] Accordingly, the instant invention has a fibrous filter media comprising a web of thermoplastic fibers. It should be understood that these thermoplastic fibers can be made of any known thermoplastic material, however preferred materials include polyolefins, polyesters, polycarbonates, polyimides, and polyamides, or mixtures of any of these materials. Although all of the above materials can be used, preferred materials include polyesters and polyolefins, such as poly(butylene-terephthalate) and polypropylene. Additionally, thermoplastic copolymers also can be used with the preferred copolymers being combinations of any of the above mentioned materials.
[0033] By a web with “enhanced particulate filtration properties” it is meant that the web of the instant invention filters better than a web that is not treated by the gaseous plasma at atmospheric conditions of the instant invention. Generally, the web of the instant invention has an ability to filter that is at least 1{fraction ( 1 / 2 )} times superior to that of the untreated web, preferably at least 2 times superior to that of the untreated web, more preferably at least 3 times superior to that of the untreated web, more preferably at least 4 times superior to that of the untreated web, and most preferably at least 5 times superior to that of the untreated web. In particular, the instant invention shows the above mentioned “enhanced particulate filtration properties” regarding being able to filter any of a number of particles such as dust, fungi, antigens, molds, other small particles, etc. or any of a number of chemical compounds such as any of a number of salts, (for example, NaCl).
[0034] In particular, the instant invention relates to a fibrous filter media comprising a web of thermoplastic fibers, wherein said thermoplastic fibers have been surface modified with a gaseous plasma at atmospheric conditions. By atmospheric conditions, it is meant that no vacuum pumps or other devices that produce reduced pressure are needed in the plasma treatment.
[0035] In another embodiment, the instant invention is directed to a method of generating a fibrous filter media with enhanced particulate filtration efficiency wherein said method comprises treating a web of thermoplastic fibers with a gaseous plasma at atmospheric conditions. The gaseous plasma treatment is done under atmospheric conditions that are adapted for surface modifying the thermoplastic fibers.
[0036] In both the fibrous filter media and the method of generating the fibrous filter media, the following conditions can be used before during or after plasma treatment.
[0037] After or before gaseous plasma treatment, the thermoplastic fibers can be electrostatically charged. Electrostatic charging of the thermoplastic fibers can be performed by any means that is known in the art with a corona discharge method being particularly preferred.
[0038] In one embodiment of the invention, the gaseous plasma treatment increases the surface area of the thermoplastic fibers relative to the case where the same or similar thermoplastic fibers do not undergo gaseous plasma treatment.
[0039] Preferred means of employing a gaseous plasma treatment on the thermoplastic fibers includes but is not limited to inert gas treatment independently or combined with air, with preferred gas combinations being He/air, Ar/air, Ne/air, Xe/air, N 2 /air, Kr/air, or any combination/mixture of these gas combinations, with the more preferred combination being Ar/air and/or He/air.
[0040] Any of the above gas combinations can be combined with a treatment with fluorine-containing plasmas to produce fibers that are electrostatically charged to generate fibers that possess improved charge stability.
[0041] In one embodiment of the instant invention, the web is a fibrous layer of melt extruded fibers or filaments. Alternatively, the web can be comprised of carded, airlaid, or wetlaid staple fibers or any combination of these or any combination that also includes melt extruded fibers. In a preferred embodiment meltblown fibers are used.
[0042] In another embodiment of the invention, a gradient of a fibrous filter media can be applied wherein fibers that are upstream are treated by a different method than fibers that are downstream, thus generating a fibrous filter media that possesses a gradient of filtering ability. It will be evident to those of skill in the art that the upstream fibers can possess either superior or inferior filtration ability to those fibers that are downstream. Any of the above-described processes can be added or omitted to this fibrous filter media to generate the aforementioned gradient.
EXAMPLES
[0043] Tables 1-6 illustrate the NaCl penetration of both plasma treated and control fibrous filter media.
Test Data For Treated And Control Heat Tested In Oven At 150 F Control Plasma Treated NaCl NaCl NaCl NaCl Penetration @ Resistance Penetration @ Resistance @ 32LPM @ 32LPM 32LPM 32LPM 1 9.55 2.0 1.25 4.4 1A 10.2 2.0 1.63 4.2 2 12.8 1.8 3.36 3.2 2A 11.1 1.9 2.42 3.7 3 10.4 1.8 4.87 2.8 3A 14.4 1.7 9.57 2.8 4 32.8 2.2 1.76 3.9 4A 10.8 2.0 2.46 3.4 Average 14.01 1.9 3.42 3.6 % Efficiency 86 96.6
[0044]
Retested after 14 hours in oven at 150 F
Control
Plasma Treated
NaCl
NaCl
NaCl
NaCl
Penetration @
Resistance
Penetration @
Resistance @
32LPM
@ 32LPM
32LPM
32LPM
1
27.8
1.9
6.91
3.7
1A
28.3
1.9
7.63
3.4
2
28.2
1.8
11.6
2.7
2A
28.3
1.9
9.14
3.1
3
22.5
1.8
11.5
2.4
3A
27.6
1.7
16.6
2.4
4
40.5
2.1
9.33
3.2
4A
24.9
1.9
11.7
2.7
Average
28.5
1.9
10.6
3.0
%
Efficiency
71.5
89.4
[0045]
TABLES 1-6
Retested after 4 days and 14 hours in oven at 150 F
Control
Plasma Treated
NaCl
NaCl
NaCl
NaCl
Penetration @
Resistance
Penetration @
Resistance @
32LPM
@ 32LPM
32LPM
32LPM
1
32.8
1.9
8.84
3.6
1A
31.6
1.8
9.95
3.4
2
32.5
1.8
13.7
2.7
2A
31.5
1.9
10.7
3.1
3
25.6
1.8
13.2
2.3
3A
30.0
1.6
16.5
2.3
4
40.5
2.1
11.5
3.1
4A
26.7
1.9
14.8
2.7
Average
31.4
1.9
12.4
2.9
%
Efficiency
68.6
87.6
[0046] It will be understood by those of skill in the art that the scope of the instant invention includes any combination of the features disclosed in this invention.
[0047] 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 intended to be included within the scope of the following claims.
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An improvement in filtration is seen by treating microfibers with a gaseous plasma at atmospheric conditions. The improvement results from etching the microfibers thereby increasing the surface area of the microfibers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for synchronously providing and selecting an oscillator from a plurality of oscillators to act as the system clock.
2. Description of the Related Art
In computer systems where oscillators are used as a clock source, it is very helpful to change the clock frequency to detect any marginal timing problem. One such method is to provide several oscillators and a controller to select one of them as the system clock source. The controller receives each of the outputs of the oscillators and also a select signal for each of the oscillators for controlling which oscillator is to be used. The controller interconnects the gate means for each of the oscillators such that no two oscillators may be turned on at the same time and to allow additional synchronization means to synchronize the system controller to the new oscillator before the new oscillator output is supplied as the clock signal for the system.
In large computer systems, the controller will typically be implemented in large scale integrated circuits. To facilitate the testing of these chips, usually the chip tester needs to treat the clock input pins as special cases because of the latches used to synchronize the new oscillator. This special treatment includes the ability to issue small pulses having a high bandwidth resulting in an increase in costs of the tester itself. Therefore, usually only a limited number of pins on the chip tester can be used as clock input pins. The number of clock input pins is a function of a number of oscillators that can act as the clock for the system. The user therefore has the option of increasing the cost of the chip tester by providing the necessary pin connection to test the plurality of oscillators used by the controller or to reduce the test coverage which is undesirable.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an apparatus which can select between a plurality of oscillators and synchronously provide the selected oscillator as the clock for the system.
It is another object of the invention to provide such an apparatus where the apparatus is part of a large scale integrated circuit when all the oscillators may be checked by a chip tester as a regular path and the clock by the use of only two clock pins.
The apparatus is comprised of two oscillator selectors. Each of the oscillator selectors has as its inputs the output of each of the oscillators and a three-bit command code which indicates which of the oscillators is to be selected by the oscillator selector and a single clock output. A different oscillator may be selected by each of the oscillator selectors at the same time. The output of the oscillator selectors are inputs to the clock controller. The clock controller also receives command signals for controlling the switching of the clock controller between the outputs of the two oscillator selectors. The output of the clock controller is the clock source for the system and a status signal indicating which oscillator selector is presently being used.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with respect to the particular embodiments thereof and reference will be made to the drawings, in which:
FIG. 1 is a diagram of the apparatus for synchronously selecting different oscillators as the system clock source.
FIG. 2 is a logic diagram of an oscillator selector used in FIG. 1.
FIG. 3 is a logic diagram of the clock controller used in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the apparatus for synchronously selecting one of a plurality of oscillators to be the system clocks is shown. The apparatus is comprised of oscillator selector A 10, oscillator selector B 11 and clock controller 12. Oscillator selector A 10 and oscillator selector B 11 are identical in construction. Oscillator selector A 10 receives a three-bit command CMD A on lines 13, 14 and 15 and the output of five oscillators on lines 16, 17, 18, 19 and 20. Oscillator selector A 10 provides the output of the selected oscillator as an A CLOCK output on line 24. Oscillator selector B receives a three-bit command CMD B on lines 21, 22 and 23, and the output of each of the five oscillators on lines 16, 17, 18, 19 and 20. Oscillator selector B 11 provides the output of the selected oscillator as B CLOCK on line 28. Clock controller 12 receives the A CLOCK of oscillator selector A 10 on line 24 and the B CLOCK on line 28 of oscillator selector B 11. Clock controller also receives command signals select oscillator SEL OSC on line 25, BLANK A on line 26 and BLANK B on line 27. The output line 29 of the clock controller 12 provides the clock for the system. Clock controller 12 also provides a STATUS signal on line 65 to indicate whether CLOCK A or CLOCK B is presently being used as the system clock.
Referring to FIG. 2, the logic comprising oscillator selector A 10 is shown. In that oscillator selector A 10 and oscillator selector B 11 are identical in structure, only oscillator selector A 10 will be discussed. The three-bits code, as shown in Table 1, of command CMD A is provided on lines 13, 14 and 15 and stored in latches 30, 31 and 32. The output of latch 30 is on line 35, of latch 31 is on line 34 and of latch 32 is on line 33. The output of each of the latches are connected to the inputs of each of AND's 36, 38, 40, 42 and 44 which effectively decode the three-bit code stored in latches 30, 31 and 32. AND 46 has the first input from AND 36 via line 37 and a second input of the output of oscillator 5 via line 20. AND 48 has a first input from AND 38 via line 39 and a second input of the output of oscillator 4 via line 19. AND 50 has a first input from AND 40 via line 41 and a second input from the output of oscillator 3 via line 18. AND 52 has a first input from AND 42 via line 43 and a second input of the output of oscillator 2 via line 17. AND 54 has a first input from AND 44 via line 45 and a second input of the output of oscillator 1 via line 16. OR 56 has a first input from AND 46 via line 47, a second input from AND 48 via line 49, a third input from AND 50 via line 51, a fourth input from AND 52 via line 53 and a fifth input, from AND 54 via line 55. The output of OR 56 on line 27 is the A CLOCK signal to be used by controller 12.
Referring to FIG. 3, the clock controller 12 is shown in detail. Control signal BLANK A is connected via line 27 into latch 60 whose output on line 63 is connected to a negative input of AND 75. The A CLOCK signal on line 24 from oscillator selector A 10 is connected to AND 83 and latches 67 and 68. Command signal select oscillator SEL OSC is connected via line 25 to latch 61 which has a first negative output on line 64 connected to the negative input of AND 79 and a positive output on line 65 connected to the negative input of AND 81 and is the STATUS signal for the status of the clock controller 12. The B CLOCK signal of oscillator selector B 12 is connected via line 28 to AND circuit 85 and latches 69 and 70. Command BLANK B is connected via line 27 to latch 62 whose output is connected via line 66 to the negative input of AND 77. The output of AND 79 is connected via line 80 to the input of latch 67. The output of AND 81 via line 82 is connected to the input of latch 69. The output of latch 67 is connected to latch 68 via line 71. The negative output of latch 68 is connected to the negative input of AND 75. The output of latch 69 is connected via line 73 to latch 70. The negative output of latch 70 is connected via line 74 to the negative input of AND 77. The output of AND 75 is connected via line 76 to AND 83 and to the negative input of AND 82. The output of AND 77 is connected via line 78 to AND 85 and to the negative input of AND 79. OR 87 has a first input from AND 83 via line 84 and a second input from AND 85 via line 86. The output on line 29 of OR 87 is the CLOCK for the system.
In operation, the three-bit command signals, COMMAND A and COMMAND B, is a three-bit code, as shown in Table 1, for selecting oscillators 1, 2, 3, 4 or 5.
TABLE 1______________________________________ COMMAND Bit 3 Bit 2 Bit 1______________________________________OSC 1 0 0 0OSC 2 0 0 1OSC 3 0 1 0OSC 4 0 1 1OSC 5 1 0 0______________________________________
The command in its present format can select up to eight oscillators and may be expanded by adding additional bits to select greater than eight oscillators.
The commands CMD A, CMD B, SEL OSC, BLANK A and BLANK B are provided in proper sequence by means of a microprocessor or by a state machine. The microcode for a microprocessor or the sequence of operation of a state machine for selecting a new oscillator as the clock is set forth below.
______________________________________ begin.sup. scanout (SEL OSC);if SEL OSC=1, then begin scanin(BLANK B,1); scanin(CMD B); wait a few cycles; scanin(BLANK B,0); scanin(SEL OSC,0);.sup. end else begin scanin(BLANK A,1); scanin(CMD A); wait a few cycles scanin(BLANK A,0) scanin(SEL OSC,1).sup. end; end______________________________________
When an oscillator selector changes from one oscillator to another oscillator, transient signals can appear on line 24 or 28 which may cause latches 67,68,69 and 70 to go into a metastable state. BLANK A and BLANK B commands to latches 60 and 62 prevents any of these transient signals from appearing in the CLOCK on line 29.
The invention will further be described with reference to FIG. 1, 2 and 3 by way of an example for a switching procedure. Assume that the apparatus is providing the output of oscillator 5 on line 20 as the system clock on line 29 via oscillator selector B 11. At this time latch 61 will be set to a zero, latches 60 and 62 will be set to a zero, latches 67 and 68 will be set to a zero, and latches 69 and 70 will be set to a one. AND 85 will be conditioned by the high output of AND 77 to allow B CLOCK on line 28 to appear on line 86 as an input to OR 87 and then as the clock on line 29. AND 83 will be deconditioned by the low output of AND 75 via line 76. The output of AND 79 will be low and the output of AND 81 will be high.
Next assume it is desired to change the output clock on line 29 to the output of oscillator 3. First, the status of latch 61 is tested by the microprocessor or state machine to determine whether latch 61 is set to a one or a zero by means of the STATUS signal on line 65. If latch 61 is set to zero then the B CLOCK is presently being used. If latch 61 is set to one, then the A CLOCK is presently being used. The system will provide the new clock signal via the oscillator selector A or B that is presently not being used to supply the clock. In that latch 61 in this case is a zero, this will indicate that the B CLOCK is presently being used and that oscillator selector A 10 will be used to provide the new clock. The BLANK A command signal is then issued via line 27 setting latch 60 to a one. The setting of latch 60 to a one will decondition AND 75 causing AND 75's output to be low regardless of the state of the signal on line 72 to AND 75. The low output of AND 75 will decondition AND 83, thereby not allowing A CLOCK to pass through AND 83 to OR 87. The three-bit, 010, code for oscillator 3 will then be issued as COM A Bit 1, Bit 2 and Bit 3 on lines 13, 14 and 15 and a set into latches 30, 31 and 32. This will cause the output of AND 40 to be high which will condition AND 50 via line 41 such that oscillator 3 appears on line 51 to OR 56 and, finally, as A CLOCK on line 27. Since the issuing of the procedure commands by the state machines is asynchronous to the system clock, the procedure waits a few cycles to allow the A CLOCK to stabilize. The A CLOCK appears on line 24 as an inputs to latches 67, 68 and AND 83. At this time, latch 67, receiving a low input on line 80 from AND 79 will remain at a zero value. This will cause latch 68 to remain at a zero value. Therefore, AND 75 will be deconditioned by both the high output on line 63 of latch 60 and the low output of latch 68 on line 72. As such, the output of oscillator 3 appearing as A CLOCK on line 24 will not be passed through AND 83. Next, the BLANK A command on line 27 will set latch 60 to a zero which will condition one input of AND 75. The command select oscillator SEL OSC on line 25 will then set latch 61 to a one which will cause the output of AND 81 on line 82 to be low. The low output of AND 81 will cause a zero to be read into latches 73 and 74. A zero in latch 74 will cause the output of AND 75 to be low. A low output of AND 75 will decondition AND 85 thereby turning off the B CLOCK. The low output of AND 75 will also cause the output of AND 80 to be high. The next clock pulse of A CLOCK will set latch 67 to a one and the following clock pulse of A CLOCK will set latch 68 to one. The output of AND 75 will be high thereby conditioning AND 83 to allow A CLOCK to appear on line 84. A CLOCK will pass through OR 87 and appear on line 29 as the clock. Therefore, the output of the system clock has been switched to oscillator 3.
The apparatus has been prepared for the next request to switch oscillators which will be done by oscillator selector B 11 to produce the B CLOCK for controller 12. Effectively, controller 12 alternates between A CLOCK and B CLOCK each time a selection procedure is performed.
Referring to FIG. 1, while the entire circuit apparatus as shown in FIG. 1 can be incorporated within a large scale integrated circuit, lines 24 and 28 may be brought off the chip and then returned to the chip where the connection between the output and input are made by printed circuit wires on a board. During testing procedures, the printed circuit wire can be disconnected such that each of the clocks may be tested as a regular path and only the two clock paths of clock controller 12 must be viewed as a special case. This obviously reduces the expense and testing load of the chip tester and provides full functional testing of the oscillators and the clock circuitry on a large scale integrated circuit.
While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the invention. Given the above disclosure of general concepts and specific embodiments, the scope of the protection sought is defined by the following claims.
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An apparatus is provided for synchronously selecting different oscillators as the system clock source. The apparatus is comprised of two oscillator selectors. Each of the oscillator selectors has as its inputs the output of each of the oscillators and a three-bit command code which indicates which of the oscillators is to be selected by the oscillator selector and a single clock output. A different oscillator may be selected by each of the oscillator selectors at the same time. The output of the oscillator selectors are inputs to the clock controller. The clock controller also receives command signals for controlling the switching of the clock controller between the outputs of the two oscillator selectors. The output of the clock controller is the clock source for the system and a status signal indicating which oscillator selector is presently being used.
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