description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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FIELD OF THE INVENTION
[0001] This invention concerns a new composition for cosmetic or pharmaceutical purposes, for external use, to be applied either on the cutis, whether integral or damaged, or on the mucous membrane, in order to improve all cutaneous pathologies both directly and indirectly affected by bacterial infections, such as for example superficial primary pyodermia and impetigo vulgaris and other common dermatitis infections, such as for example atopic dermatitis and the various forms of eczema.
STATE OF THE ART
[0002] Antibiotic therapy for topical use is used preferably in the dermatological field in that it allows the use of sufficient quantities of active principle in the area directly affected by the infectious process, avoiding the risks connected with systematic antibiotic therapy.
[0003] Triethyl citrate, that is a triethyl ester of citric acid, is well known and used in the cosmetic sector for the treatment of ageing of the skin (U.S. Pat. No. 5,686,489 dated 21 Nov. 1997), but it has never been either proposed or suggested as an active ingredient for the treatment of bacterial cutaneous infections, neither alone or in synergy with other substances.
[0004] Now, following specific research and experiments carried out by the inventor, it has become clear that the active ingredient, triethyl citrate taken into consideration herein, carries out an activity, comparable to and which can be placed over substances possessing antibiotic, antiseptic and disinfectant activities, without generating bacterial resistance phenomena (on the contrary to the more common antibiotics).
OBJECTS AND SUMMARY OF THE INVENTION
[0005] This invention is based on the results of this research, and therefore its primary object is to propose the use of a new active principle useful at least in the cure of cutaneous pathologies involving infections having bacterial origins.
[0006] A further object of the invention is to provide an active principle for the formulation of products, both cosmetic and pharmaceutical, to be used locally in the treatment of cutaneous infections caused by bacteria, without producing bacterial resistance.
[0007] Yet another scope of the invention is to provide an active composition for the cure of cutaneous infections and which, advantageously, used in combination with antibiotics, antiseptics and disinfectants is able to prevent the setting in of bacterial resistance phenomena.
[0008] These aims are achieved, according to the invention, with a composition for cosmetic and pharmaceutical use containing triethyl citrate, as an active ingredient, pure or in association with synergists.
DETAILED DESCRIPTION OF THE INVENTION
[0009] In this invention and for the use given above, triethyl citrate may be used pure with suitable supports or vehicles, or better formulated with other chemical substances, such as synergists, additives and excipients as a percentage by weight from 0.1 to 99.9%, preferably from 0.5 to 50%, and better still from 5.0 to 15% on the basis of the final formulation, for both cosmetic and pharmaceutical preparations for local use.
[0010] Accordingly, the active ingredient represented by triethyl citrate can be used, for example, in combination with substances which are part of the chemical group which include carboxylic acids, hydroxyacids, vitamins, amino acids, bioflavonoids, oligoelements, essential fatty acids and relative esters, antibiotics, sulphamides, disinfectants. Oleic, linolic and linolenic acid ethyl esters and other compounds such as for example erythromycin, clindamycin, metronidazole, gentamicin, fusidic acid, econazole, ketoconazole, mupirocin, hydrogen peroxide, benzoyl peroxide, cetylpyridinium, silver and relative salts, both organic and inorganic.
[0011] Synergists are understood to be for example: trans-retinal acid, retinol, retinaldehyde, tocopherol, ascorbic acid, p-aminobenzoic acid, rutin, β-Carotene, tiamin, riboflavin, pyridoxine, pyridoxale, niacin, nicotinic acid, nicotinamide, pantothenic acid, pantenol, glucosamine, aceylglucosamine, folic acid, lecithin, phosphplipids such as, for example phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, lyso-phosphatidylcholine, hydroquinone, oleic acid, linoleic acid, linolenic acid, ethyl oleate, ethyl linolenate, ethyl linoleate, Kojic acid, ascorbyl glucoside, erythromycin, clindamycin, metronidazole, gentamicin, fusidic acid, econazole, ketoconazole, mupirocin, neomocin, stretomicin, hydrogen peroxide, benzoil peroxide, cetylpyridinium, benzalkonium, chlorhexidin and relative salts and esters, silver and relative salts, both organic and inorganic, hydroxyacids and β hydroxyacids, both mono and bi carboxyls, such as glycolic acid, lactic acid (in the dextro and levorotatory forms and in racemic mixtures) hydroxybutyric acid (in the dextro and levorotatory forms and in racemic mixtures), mandelic acid (in the dextro and levorotatory forms and in racemic mixtures), tartaric acid (in the dextro and levorotatory forms and in racemic mixtures), malic acid (in the dextro and levorotatory forms and in racemic mixtures), salicylic acid, 3-hydroxybenzoin acid, 4-hydroxybenzoin acid, cysteine, acetyl cysteine, glycine, used singularly or in association with one or more including the relative salts, esters and amides and the relative D-L-DL forms.
[0012] The components of this group of substances can be used in association with triethyl citrate in a percentage by weight from 0.01% to 50% in weight, preferably from 0.5 to 15%.
[0013] The following EXAMPLES of preparations illustrate even further the efficacy of the composition of this invention which contains triethyl citrate as an active ingredient.
[0014] Triethyl citrate, possibly associated with appropriate synergists as described above, can be used in formulations for external use, such as a water emulsion in oil, oil emulsions in water, single phase solutions, dual phase pseudo-solutions, single phase gels, dual phase gels, anhydrous ointments and in powder form etc, using appropriate supports and vehicles. EXAMPLES of preparations based on triethyl citrate base.
PREPARATION 1
[0015]
No.
Description
01
Triethyl citrate
100
[0016] Preparation method: use as it is
PREPARATION 2
[0017]
No.
Description
01
Triethyl citrate
20.00
02
Erythromycin
2.00
03
Ethyl alcohol
60.00
04
Deionised water
18.00
[0018] Preparation method: dissolve 02 in 03; mix 01 in the solution obtained; then add 04
PREPARATION 3
[0019]
No.
Description
01
Triethyl citrate
6.00
02
Salicylic acid
0.50
03
Ethyl alcohol
60.00
04
Deionised water
33.50
[0020] Preparation method: dissolve 02 in 03; mix 01 in the solution obtained; then add 04
PREPARATION 4
[0021]
No.
Description
01
Triethyl citrate
25.00
02
Retinic acid
0.025
03
Ppg - 15 stearyl ether -as needed
100
[0022] Preparation method: dissolve 02 in 03; mix 01 in the solution obtained;
PREPARATION 5
[0023]
No.
Description
01
Triethyl citrate
95.00
02
Ethyl linoleate
5.00
[0024] Preparation method: dissolve 02 in 01;
PREPARATION 6
[0025]
No.
Description
A)
01
Triethyl citrate
10,000
02
Steareth-2
3,000
03
Steareth-21
2,000
04
Vaseline oil
1,000
05
Stearic acid
5,000
B)
06
Preservatives
As needed
07
Glycerol
4,000
08
Deionised water
As needed
100
[0026] Preparation method: the ingredients (A) and ingredients (B) are heated separately at 70° C. Then ingredients (B) are added to ingredients (A) mixing until a well amalgamated mixture in the form of an emulsion for topical use is obtained.
PREPARATION 7
[0027]
No.
Description
01
Triethyl citrate
5,000
02
Chlorhexidine gluconate
0,250
03
Idrossietil cellulose
1,000
04
Deionised water as needed
100
[0028] Preparation method: dissolve 01+02 in 04; in the solution obtained disperse 03 until complete solvation and formation of a gel. | This invention concerns a composition for topical use containing as an active ingredient triethyl citrate either pure or in combination with synergists, and the pharmaceutical or cosmetic use of the composition, on its own or in association with an antibiotic, at least in the treatment of cutaneous pathologies directly or indirectly affected by bacterial infections. | 0 |
TECHNOLOGICAL FIELD
The present invention pertains to electronically active, micromachined structures and to a method for their encapsulation. Examples of such structures are micromachined accelerometer sense elements.
DESCRIPTION OF THE RELATED ART
Physical and chemical micromachining techniques, many of which were originally developed in connection with integrated circuit and microprocessor fabrication, have enabled the production of micromachined structures which are electronically "active" in the sense that the structures move, deform, or are stressed due to changes in the physical environment of the structure, and one or more electrical properties associated with the structures are altered as a result. For example, such micromachined structures may be sensitive to stimuli such as change in temperature, acceleration, force, and the like. The electronic activity associated with the device may represent a change in a digital condition, or a change in capacitance, resistance, inductance, or the like.
For example, a torsion beam accelerometer may be micromachined from silicon as illustrated by U.S. Pat. No. 5,488,864. In such accelerometers, dual tilt plates, one of higher mass, are suspended by a torsion beam. Upon acceleration, the greater inertia of the higher mass plate will cause the tilt plates to rotate about the torsion beam axis. This rotation may be reflected by changes in capacitance between the heavy side and light side tilt plates and conductive pads located below them on the base of the structure, or by other means. Devices such as that just described are very tiny, and are manufactured by semiconductor processing techniques. Other accelerometers and microstructure devices are disclosed in U.S. Pat. Nos. 5,447,068; 5,404,749; 5,352,635; 4,945,773; and 5,188,983; which are herein incorporated by reference. Their changing capacitance may be translated into a signal reflective of acceleration by circuitry such as that disclosed in U.S. Pat. No. 5,495,414.
Manufacturing and device packaging associated with such transducers present unique problems due to the physically active nature of the microstructures. To maintain a stable environment and to keep out dust particles, corrosive and/or potentially fouling vapors, etc., the micromachined structures must be enclosed within a sealed package. Traditional integrated circuit encapsulation methods such as epoxy resin potting and thermoplastic injection molding, while useful with integrated circuits which have no moving parts, are incapable of use directly with micromachined structures. The encapsulant must not contact the active portions of the micromachined structure. Moreover, common encapsulation techniques such as injection molding, often requiring pressures of 1000 psi, would easily crush the microstructure.
In addition to protecting the microstructure during use, the structure must also be protected during post-fabrication processing. For example, such microstructures are produced by processing many identical devices or a single silicon wafer substrate. Following the various micromachining steps, i.e., deposition, masking, etching, ion implantation, and diffusion steps, the finished devices must be separated by sawing the wafer. Many devices are damaged in such operations.
In U.S. Pat. No. 5,188,983, a method of encapsulating a micromachined accelerometer sense element is disclosed wherein the active sense elements are deposited on a sacrificial layer, and a further sacrificial layer is applied over and encompassing the structure, the sacrificial layer having an external shape corresponding to the internal dimensions of the desired encapsulating cavity. Polysilicon is then deposited, forming a shell around the device, this shell having numerous flow channels located along its periphery. The sacrificial layers are then etched away by chemical etchant flowing through the peripherally located flow channels, the device thoroughly washed, evacuated, and the flow channels sealed.
Both the process as well as the device disclosed in the '983 patents have numerous drawbacks. Deposition of the additional sacrificial layer and polysilicon shell elevate the processing cost and processing time. More importantly, however, the etching away of the sacrificial layers by means of etchant flowing through the rather small peripheral flow channels is troublesome. In addition to being relatively inefficient, the etching cannot be made completely uniform. If particles slough into the interior of the cavity, they may not be able to escape the cavity through the small flow channels in the shell, and thus the yield of useable devices will be affected. Moreover, while helpful to lessen microstructure damage during wafer sawing operations, the polysilicon shell is too fragile to withstand injection molding pressure, and thus further encapsulation methods are restricted.
It would be desirable to be able to encapsulate an electronically active micromachined structure within a cavity by simple and time efficient techniques in high useable device yield. It would be further desirable to be able to provide encapsulated devices with chemically well defined surfaces on the structural components and with selectable cavity atmosphere. It would be yet further desirable to provide encapsulated devices which may be further encapsulated by traditional potting and injection molding techniques without damage or alteration to the microstructure.
SUMMARY OF THE INVENTION
A cost-effective method of encapsulating active micromachined structures within a cavity has been developed which not only provides a suitable working cavity for the structure, but which also protects the structure during subsequent wafer sawing and further device encapsulation. The method involves fabrication of multiple, active, micromachined structures on a single silicon wafer in such a manner that wafer planarity surrounding the individual microstructure is maintained; etching or otherwise providing respective corresponding cavities in a second wafer of silicon, glass, or glass-coated silicon; aligning the second wafer atop the first wafer such that the microstructures are positioned within their respective cavities; and fusion bonding or anodically bonding the wafers together. The wafer is then sawed to obtain individual silicon-encapsulated microstructures. The microstructures preferably contain one or more access windows which allow bonding of leads to the necessary conductive paths. However, the access windows do not communicate with the device cavities. Following lead bonding, the devices may be further encapsulated by known methods, including resin potting and injection molding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a plan view of a portion of a silicon wafer during one stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, illustrating formation of conductive areas on the wafer.
FIG. 1a illustrates a cross-section across 1a--1a of FIG. 1.
FIG. 2 illustrates a plan view of a portion of a silicon wafer during a further stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process.
FIG. 2a illustrates a cross-section across 2a--2a of FIG. 1.
FIG. 3 illustrates a plan view of a portion of a silicon wafer during another stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, showing cantilever deposition.
FIG. 3a illustrates a cross-section across 3a--3a of FIG. 1.
FIG. 3b illustrates the cross-sectional structure of FIG. 3 across 3a--3a prior to etching away the remainder of the deposited polysilicon.
FIG. 4 illustrates a plan view of a portion of a silicon wafer during one stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, showing release of the cantilever by removal of sacrificial glass layer.
FIG. 4a illustrates a cross-section across 4a--4a of FIG. 1.
FIG. 5 illustrates a plan view of a portion of a silicon wafer during one stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, showing formation of a time-etched encapsulation cavity in a second wafer.
FIG. 5a illustrates a cross-section across 5a--5a of FIG. 1.
FIG. 5b illustrates the cross-sectional structure of FIG. 5 across 5a--5a prior to removing etch resist and forming the encapsulating cavity.
FIG. 6 illustrates a plan view of a portion of a silicon wafer during one stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, showing formation of an access window.
FIG. 6a illustrates a cross-section across 6a--6a of FIG. 1.
FIG. 6b illustrates the wafer of FIG. 6 across 6a--6a prior to plasma etching windows in the silicon nitride coating as shown in FIG. 6c.
FIG. 6c illustrates the wafer of FIG. 6 across 6a--6a after formation of the windows in the mask of FIG. 6b but prior to the etching through of the wafer to provide the access windows of the wafer of FIG. 6.
FIG. 7 illustrates a plan view of a portion of a silicon wafer during one stage of fabrication of a cantilever-type accelerometer microstructure sense element and its subsequent encapsulation according to one embodiment of the subject process, showing the finished cavity and access window in the encapsulating wafer prior to fusion bonding atop a first wafer.
FIG. 7a illustrates a cross-section across 7a--7a of FIG. 1.
FIG. 8 illustrates a plan view of an encapsulated cantilever-type accelerometer sense element with access window to exposed lead bond pads.
FIG. 8a illustrates a cross-section across 8a--8a of FIG. 1.
FIG. 9 illustrates a plan view of an encapsulated torsion beam accelerometer.
FIG. 9a illustrates a cross-section across 9a--9a of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In its most basic form, the subject invention involves micromachining from a single wafer, multiple microstructure devices, complete with conductive paths leading to bonding pads remote from the devices to facilitate attaching electrical leads, the micromachining being performed in such a manner as to leave the surface surrounding the microstructure planar. The planar surround allows subsequent fusion bonding of a further silicon wafer, or anodic bonding of a further glass wafer, or glass-coated silicon wafer atop the first, resulting in a fully sealed and robust device to which the appropriate electrical leads may be attached and the device further encapsulated using conventional techniques. The particular micromachining, diffusion, ion implantation, etching steps, etc., are not overly critical except insofar as a planar surround is maintained, preferably with a planarity which is the same or substantially the same as the silicon wafer on which the devices are fabricated. It should be noted, however, that subsequent to the initial formation of conductive areas (pads, paths, etc.) on the silicon wafer by diffusion, subsequent processing steps such as deposition, annealing, and fusion bonding should be selected so as not to unduly disturb the initial diffusion. Those skilled in the art can readily adjust the necessary processing parameters. For example, the initial diffusion may be performed at a temperature somewhat higher than that customarily used, and the time and temperature of subsequent steps reduced accordingly.
Suitable chemical and physical micromachining steps, including those used to form pn junctions, conductive surfaces and/or paths, pads, etc., are by now well known to those skilled in the art. Reference may be had to U.S. Pat. Nos. 4,945,773; 5,188,983; 5,352,635; and 5,488,864; and various publications, i.e. Y. B. Gianchandani and K. Najafi, A Bulk Silicon Dissolved Wafer Process For Microelectromechanical Devices, IEEE J. OF MICROELECTROMECH. SYST., vol. 1, pp.77-85, June 1992; R. T. Howe, Surface Micromachining For Microsensors And Actuators, J. VAC. SCI. TECH., vol. B6, pp. 1809-1813, 1988; H. Seidel, L. Csepregi, A. Heuberger, and H. Baumgartel, Anisotropic Etching Of Crystalline Silicon In Alkaline Solutions: I. Orientation Dependence And Behavior Of Passivation Layers, J. ELECTROCHEM. SOC., vol. 137, pp. 3612-3626, November 1990; A. Hanneborg, Silicon Wafer Bonding Techniques For Assembly Of Micromechanical Elements, Proc. IEEE MICRO ELECTRO MECH. SYST. WORKSHOP, Nara, Japan, pp. 92-98, January/February 1991; and W. C. Tang, Digital Capacitive Accelerometer, U.S. Pat. No. 5,447,068. All these patents and publications are herein incorporated by reference.
The particular microstructure is not critical to the process or device of the present invention. Suitable microstructures include those cited in the foregoing patent and literature references, for example, as well as others, and include strain gauge pressure transducers, resonant strain gauges, vibratory transducers, lateral and orthogonal accelerometer transducers, and the like. The process is particularly suitable for a wide variety of accelerometer transducers.
Following the micromachining of the multiple, electronically active microstructures on the silicon wafer, a second silicon wafer is etched so as to contain cavities of a size suitable to enclose the active portions of the microstructures. The two wafers are then sandwiched together and heated to fusion bond the cavity-providing wafer to the microstructure-providing wafer along the planar surrounds around each microstructure. In order to provide for bonding electrical leads, the cavity-providing wafer is generally etched so as to contain a plurality of sets of one or more access windows, each window of which correspond to the location(s) of one or more bonding pads. The atmosphere in the bonding chamber may be varied from a vacuum to a modest pressure. The gas, or residual gas in the case of a vacuum, may be varied to suit the application, i.e. may be dry nitrogen, carbon dioxide, helium, argon, or other gas mixtures, including moist gas if appropriate. The atmosphere of the bonding chamber will then become the cavity atmosphere.
In lieu of a second silicon wafer, a glass wafer or a glass coated silicon wafer, in either case containing the necessary cavities and access windows, may be anodically bonded to the first, microstructure-containing wafer. Anodic bonding techniques are well known to those skilled in the art. An advantage of anodic bonding is that it may be effected at lower temperatures, i.e., in the range of 400° C. to 500° C. Thus, this method may be preferable for microstructures which are temperature sensitive. Fusion bonding of silicon is preferred for most applications, however, as the hermeticity is generally superior to that which is obtained by anodic bonding, and the coefficients of thermal expansion of the microstructure wafer and encapsulating wafer are identical. In this respect, a glass coated silicon encapsulating wafer provides both close matching of thermal expansion coefficients and a low bonding temperature.
The use of the subject invention may now be described with reference to the Figures. FIGS. 1 to 8 describe one embodiment of the subject process as it pertains to manufacture of a cantilever-type accelerometer sensor. The subject process is, of course, applicable to other types of accelerometer sensors as well as sensors of a variety of different types. FIG. 9, for example, illustrates a different microstructure sensor. In each Figure, a plan view of a portion of the wafer being processed is given together with a cross-section across a section a--a of the wafer. Further cross-sectional views represent processing steps immediately prior to the main Figure where appropriate. Steps such as photolithographical resist deposition, resist removal, etc., which are well understood to those skilled in the art, are omitted for purposes of brevity and clarity. It should be understood that many such microstructures will be machined simultaneously on the same wafer.
In FIG. 1, a polished, p-type silicon wafer 1 is coated with a photoresist mask using traditional photolithography techniques, the bare areas being subjected to ion implantation or diffusion with phosphorus or arsenic to form n+ doped regions 3, 5, 7, 9 and conductive paths 6 and 8, electrically isolated from the p-type substrate by the pn junctions formed. Region 3 is destined to be the support surface for the active, acceleration-deflective cantilever, and also to provide electrical continuity with the cantilever. Region 5 will serve as a bond pad to subsequently bond an electrical lead, electrical communication between the support surface 3 and bond pad 5 being provided by conductive path 6. Region 7 is the bottom electrode and serves as a fixed plate of a variable capacitor, the second, moveable plate, being the cantilever. The bottom electrode 7 communicates via conductive path 8 with bond pad 9.
Following removal of the photoresist, the portion of the wafer in cross-section 1a--1a is shown in FIG. 1a. At 3 is the ion-implanted (or diffused) n+ region corresponding to the cantilever support surface, while at 4 is the n+ region corresponding to bottom electrode, conductive path 8, and bond pad 9. At 3a and 4a is a pn junction formed at the diffusion boundary which electrically isolates the n+ regions from the substrate. Optionally, a metal lift-off step or other metallization process may be used to metallize bond pads 5 and 9 to enhance the final lead bonding operations. Note that during this process, the area 10 surrounding the various pads, etc., has not been subject to any silicon etch or deposition, and hence retains its planarity, being mutually coplanar with other similar areas around other microstructures on the same wafer. Further, conductive paths 6 and 8, as is also the case with conductive regions 3, 5, 7, and 9, having been doped by ion implantation and/or diffusion, are also flush with the original substrate surface.
Referring now to FIGS. 2 and 2a, a layer of 2 μm to 5 μm thick low temperature silicon oxide (LTO) (21, FIG. 2a) is deposited by LPCVD and densified at 1000° C. for one hour. A second photolithography step is used to bare an "anchor" window 23 communicating with the support surface 25 (3, FIG. 1) onto which the cantilever anchor will be deposited. An additional photolithography step may be used to etch dimples in the LTO which will subsequently allow casting of anti-sticking bumps on the underside of the microstructure, i.e. on the lower side of the cantilever and above the surface of the bottom electrode (7 in FIG. 1).
As shown in FIG. 3b, in situ phosphorus doped polysilicon 31 is deposited uniformly to a thickness of 2 μm to 5 μm by LPCVD. A subsequent optional annealing (1000° C., 1 hour) reduces the built-in stress in the polysilicon layer. Alternatively, undoped polysilicon can be used for layer 31 if the topmost portion of layer 21 is phosphosilicate glass (PSG) instead of LTO. Phosphosilicate glass may also be deposited by LPCVD. In such a case, the phosphorus atoms from the PSG diffuse into the polysilicon layer during the subsequent annealing, doping the latter to render it conductive. At the same time, the bottommost LTO portion of layer 21 prevents further doping of the silicon substrate 1. The cantilever 35 (FIGS. 3, 3a) is created by applying a resist of the desired cantilever outline photolithographically, and using a plasma etch or reactive-ion etch (RIE) to remove unwanted polysilicon from around the cantilever microstructure.
Referring now to FIGS. 4 and 4a, the sacrificial LTO layer 21 (FIG. 3) is removed by dissolving with hydrofluoric acid, exposing the released cantilever 35 anchored to support area 3 by anchor portion 37, the active portion 39 suspended above bottom electrode 7. The hydrofluoric acid solution does not attack silicon and polysilicon. At this stage, device testing may be conducted by contact the appropriate bonding pads with test leads.
The devices must now be encapsulated. Referring to FIGS. 5, 5a and 5b, a second p-type silicon wafer 2, for example one having a thickness of c.a. 150-250 μm, has silicon nitride deposited on both sides by LPCVD as shown in FIG. 5b, the upper silicon nitride layer shown as 51 and lower silicon nitride layer as 53. With reference to FIG. 5, a photolithography step applies etch resist to all but a rectangular portion 55 of the bottom silicon nitride surface 53. A plasma etch removes silicon nitride from portion 55, following which a time-etched cavity 57 is prepared by immersing the wafer into a strongly alkaline KOH solution. The predefined cavity depth may range from 50 to 150 μm depending upon the working depth required to contain the microstructure to be encapsulated. Deeper or more shallow cavities may be prepared as well. The depth is, of course, limited by the thickness of wafer 2. The roof 59 of the cavity should preferably be between 70 μm and 25 μm thick. Following cavity preparation, wet chemistry is used to strip away the silicon nitride mask.
A bonding access window is now created by again depositing silicon nitride on both sides of wafer 2 forming top silicon nitride layer 61 and lower layer 63, as shown in FIG. 6b. A photolithographically deposited resist followed by plasma nitride etch removes silicon nitride at areas 65, as shown in FIG. 6c. A strongly alkaline etch dissolves away the p-type silicon, leaving a through-window bonding access hole 67 (FIGS. 6, 6a). The silicon nitride mask is then stripped leaving a top, encapsulating wafer having a plurality of encapsulating cavities 57 and access windows 67 a single pair of which are shown in FIG. 7 and 7a. Similar steps may be used to form microstructure cavities and bond access windows from glass or glass-coated silicon encapsulating wafers.
As shown in FIGS. 8 and 8a, the top wafer 2 is indexed over the bottom wafer 1 following conventional cleaning and hydrating, and pressed together to initiate contact, followed by heating at 1000° C. for one hour to form a silicon-to-silicon fusion bond. In FIG. 8, the cantilever 35 which must move in response to acceleration orthogonal to the face of the wafer/device, is encapsulated within cavity 57. Due to the planarity of the surfaces surrounding the active device (cantilever) and the planarity of the encapsulating wafer 2, an impenetrable fusion bond 81 is formed around the microstructure. Note that the conduction paths 6 and 8 are also planar, having been provided by ion implantation, diffusion, or other techniques which leave a planar surface, hence the hermetic seal 81 extends across these paths. The lead bond pads 5 and 9 are exposed by access window 67, facilitating the bonding of electrical leads by conventional techniques. Following the fusion of encapsulating wafer 2 onto microstructure-carrying wafer 1, or anodic bonding in the case of glass or glass-coated silicon encapsulating wafers, the wafer may be sawed or otherwise processed into discrete components by conventional means, in excellent useable device yield.
While the subject process has been described in relation to a cantilever-type accelerometer sense element microstructure, it is certainly not limited thereto. Other active microstructure devices requiring encapsulation such as tilt plate accelerometers, lateral accelerometers, strain gauges, and the like may be encapsulated by the inventive method as well.
Referring to FIG. 9, a tilt plate, torsion beam accelerometer is shown in plan and in cross-section. At 91a and 91b are the upper "sensing" plates. Below the sensing plates at 93a and 93b are the respective lower electrodes, connected via conductive paths 95a and 95b to bond pads 97a and 97b. At 92 is a conductive "anchor" pad on which polysilicon pedestal 94 and torsion beam 90 have been deposited. Anchor pad 92 is connected to sense element bond pad 96 through conductive path 94. Portion 98 of the sense element, in conjunction with associated lower plate 99, conductive path 100, and bond pad 101, provides a self test function. The sense element microstructure will be enclosed in a cavity provided by the encapsulating wafer. The outer dimensions of the cavity are shown by dotted line 103. The bond pads will be accessed through an access window through the encapsulating wafer, the outline of which is shown by solid line 105. Surrounding the microstructure is fusion bonded surround 104.
A cross-section across 9a--9a is shown in FIG. 9a. The lower test plates 99 and sensing plate 93b as well as bond pad 97b are preferably created as conductive doped areas as described previously, although plates 93b and 99 may be metallized if desired, as these will reside within cavity 57 in encapsulating wafer 2. At 67 is the access window to the bond pads, while at 104, the surround is shown fusion bonded to the encapsulating wafer.
Maintenance of substantial planarity surrounding the microstructure is necessary in order to satisfactorily bond the microstructure wafer and the encapsulating wafer, whether fusion bonding or anodic bonding is contemplated. This planarity must in general be maintained by avoiding steps which significantly etch the areas surrounding the microstructure, which may be termed the "fusion bond surround" or "bond surround". The term "fusion bond surround" is retained when anodic bonding is contemplated as well. By the same token, substantial deposition onto the bond surround areas is undesirable as well. However, it would be within the spirit of the invention to employ etching or deposition steps where the planarity of the bond surround is evenly maintained, or is restored by micromachining, laser ablation, or other techniques. Further, rather than creating the micromachined microstructure above the surface of the polished wafer, it is possible to first etch cavities in the microstructure wafer and micromachine the relevant microstructures within the cavity such that the cavity and microstructure-containing wafer may be sealed by applying a flat wafer atop the cavity and microstructure-containing wafer. The bonding still occurs along the bond surround.
By the term "electronically active microstructures" is meant a microstructure whose electrical characteristics change in response to an external stimulus. Electronically active devices may produce an output voltage or current in response to such stimulus, or may be passive in the sense that the electronically active microstructure exhibit a change in resistance, inductance, capacitance, or digital state. By "mutual coplanar condition" as that term pertains to the fusion bond surrounds is meant a condition of planarity such that upon superposition of a second, planar wafer atop the first wafer, the coplanarity is such that there will be substantially uniform contact between fusion bonding surrounds over the greatest part, preferably all, of the microstructure-containing wafer, and the bonding surround-contacting faces of the second wafer, whether the second wafer is silicon, glass, glass-coated silicon or equivalent bondable encapsulating wafer. If substantial coplanarity is not maintained, device yield will suffer due to non-contacting surfaces not being bonded.
By the term "cavities defined between the surfaces of the wafers" and like terms is meant that the complete cavities will be formed upon the fusion of the two wafers. All or only a portion of the individual cavities may be in any one wafer. Preferably, the entire cavity is etched in the second, encapsulating wafer. By the term "respective" is meant the particular cavity destined to enclose a particular, corresponding microstructure. The microstructures and their respective cavities will generally form a two-dimensional array. It would not depart from the spirit of the invention to have more cavities than microstructures. It is highly preferable that the wafer areas around the cavities, and the wafer areas corresponding to the bonding surrounds be continuous, i.e. there will be no access holes or the like created which communicate with the cavity itself, i.e. the encapsulated microstructure-containing devices will be free of cavity-communicating passages" such as would later require sealing.
By the term "non-surface planarity-modifying doping procedure" is meant a doping procedure which is capable of modifying the current carrying capacity and/or carrier type within a region of a silicon wafer without increasing or decreasing the surface height or regularity such that bonding coplanarity of the surround areas cannot be maintained. Acceptable doping procedures generally show little and preferably no detectable change in the appearance of the wafer surface. By the term "non-silicon encapsulant" is meant an encapsulant other than silicon, doped silicon, polysilicon, etc. The term does not exclude siliceous encapsulants such as glass, ceramic, or silicone encapsulants. The majority of non-silicon encapsulants will be glass, ceramic, or thermoset or thermoplastic polymer. The term "bonding" in the claims should be interpreted to include both fusion bonding and anodic bonding, i.e. direct surface to surface bonding. If fusion bonding alone is contemplated, then the term "fusion bonding" is used appropriately.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein. | A process for the preparation of hermetically sealed electronically active microstructures involves the preparation of a plurality of microstructures and associated conductive paths and lead bond areas on a single wafer such that areas surrounding the microstructures are maintained in a planar condition. A second wafer having a plurality of microstructure-receiving cavities is placed atop the first wafer and fusion or anodically bonded. The microstructures are preferably connected to lead bond pads which lie outside the surround, the second wafer also having bond pad accessing through-holes to facilitate bonding electrical leads to the devices after sawing from the wafer. The lead-connected devices may be further encapsulated by injection molding, potting, or other conventional encapsulative packaging techniques. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 60/640,085 filed Dec. 30, 2004 with the U.S. Patent and Trademark Office, the disclosure of which is incorporated by reference in its entirety herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to installing a flat panel display device. It also relates to aligning a component or components along a preferred plane to provide an optimal viewing experience.
[0004] 2. Description of Related Art
[0005] Until fairly recently, a consumer only had the choice of using a typical cathode-ray tube television or an analog big screen projection television for use as a display in a home entertainment or home theater system. The advent of the many digital displays, which include flat panel displays like plasma display devices (PDPs) and liquid crystal displays (LCDs), as well as digital projection technologies, like digital light processing (DLP™), now provide may options for the home user.
[0006] Normally, these new digital displays are much lighter and take up less space than their similarly sized analog predecessors. Accordingly, they can be installed in many different ways. For example, flat panel displays can be hung directly on a wall, while a DLP™ projector can be paired with a movie screen and be used like a slide projector or mounted from the ceiling. These installations ensure that the room where the home entertainment system is located is not cluttered with bulky equipment. On the other hand, these arrangements can be difficult to install and an a mistake by an unskilled installer or a do-it-yourselfer may result in a display that is slightly askew, i.e. not installed at a proper viewing angle.
[0007] Thus, there is a need for making the installation easier to ensure a proper installation of these digital displays. That way, the user who has invested considerable time and money in acquiring and/or setting up a home entertainment or home theater system does not get stuck with a “crooked” display. Alternatively, there is a demand for providing a way of compensating for any mistakes in installing a digital display, so that the home entertainment system user may still enjoy a high-end multimedia experience.
SUMMARY OF THE INVENTION
[0008] Accordingly, the invention may address these problems by facilitating the installation of a display at a proper angle. The invention can also facilitate the display of video at a proper alignment angle even if the installation of the display is improper. The invention may be suitable for the integrated multimedia system like the one described in U.S. patent application Ser. No. 11/198,356 filed Aug. 8, 2005, which is hereby incorporated by reference in its entirety.
[0009] The invention provides an adjustable bracket for mounting a display device that includes a faceplate having an interface corresponding to a mounting position on a display device; a plurality of holes adapted to receive a fastener disposed on the face plate; and a level device disposed on the face plate. The level device indicates that an edge of the faceplate is substantially level.
[0010] The invention also provides a removable display device installation apparatus, which includes a floor stand surface that supports the installation stand on a supporting surface; and a display support surface coupled to the floor stand surface that supports a display device above the supporting surface. The display support surface is substantially parallel to the floor stand surface. The display support surface of the installation stand aligns a bottom surface of the display device on a plane substantially parallel to the supporting surface.
[0011] Also, a method of mounting a display device is disclosed. The method includes placing an installation apparatus on a supporting surface to align the supporting apparatus on a plane substantially parallel to the supporting surface; providing a bracket structure adapted to receive the display device coupled with the installation apparatus; and mounting the display device onto the bracket to secure the display device to a mounting surface substantially perpendicular to the supporting surface. An edge of the display device is substantially parallel to the supporting surface.
[0012] Moreover, the invention discloses a display device installation apparatus that includes a bracket adapted to receive a display device and a floor stand coupled to the bracket. The floor stand is substantially parallel to the bracket
[0013] Additional features and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. For example, while the invention was developed to solve certain problems related to installing digital displays, it may be used in other applications and with other devices where aligning components is desirable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the detailed description serve to explain principles of the invention. No attempt is made to show structural details of the to invention in more detail than may be necessary for a fundamental understanding of the invention and the various ways in which it may be practiced.
[0015] FIG. 1 illustrates a plan view illustrating the alignment of a projector and a viewing screen according to an embodiment of the invention.
[0016] FIG. 2 illustrates a plan view of a leveling device included in a viewing screen.
[0017] FIG. 2A illustrates a close-up view of the area “A” of FIG. 2 .
[0018] FIG. 3 illustrates a front elevational view of a leveling device included in a mounting bracket according to another embodiment of the invention.
[0019] FIG. 4 illustrates a front elevational front view showing an operation of the mounting bracket from FIG. 3 .
[0020] FIG. 5 illustrates a side elevational view showing an image correction system according to an embodiment of the invention.
[0021] FIG. 5A illustrates a side elevational view of a vertical adjustment of a projector according to an embodiment of the invention.
[0022] FIG. 5B illustrates a plan view of a horizontal adjustment of the projector according to an embodiment of the invention.
[0023] FIG. 5C illustrates a side elevational view of a vertical adjustment of a projector according to another embodiment of the invention.
[0024] FIG. 6 illustrates a side elevational view of a removable installation apparatus according to an embodiment of the invention.
[0025] FIGS. 6A, 6B , 6 C, and 6 D illustrate perspective views of various stages of mounting a flat panel display against a wall using the removable installation apparatus of FIG. 6 .
[0026] FIG. 7 illustrates a front elevational view of the removable installation apparatus of FIG. 6 and a plane associated therewith.
[0027] FIG. 8 illustrates a front elevational view of a flat panel display disposed behind a lowered viewing screen according to an embodiment of the invention.
[0028] FIG. 8A illustrates a side elevational view of the flat panel display and lowered viewing screen of FIG. 8 .
[0029] FIG. 9 illustrates a front elevational view of a flat panel display and raised viewing screen disposed in a housing according to an embodiment of the invention.
[0030] FIG. 9A illustrates a side elevational view of the flat panel display and raised viewing screen of FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
[0031] The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.
[0032] As shown in FIG. 1 , an alignment system 100 includes a viewing screen 105 and a display device 110 . Here, a typical viewing screen that is well-known to those having ordinary skill in the art is used for screen 105 , and a DLP™ projector mounted on a ceiling is used as display device 110 .
[0033] The screen 105 includes an emitter 115 , which can be a laser, a radio transmitter, or other emission device. The emitter 115 may be located on a housing 107 of the screen 105 that comprises a motor (not shown) for raising and lowering the screen. The power supply could be a small battery or be a power source that drives the motor if the screen is motorized to draw up and down. The display device 110 may include a receptor 120 that receives the emission, also known as a medium, be it light, laser, or a radio signal, from emitter 115 . However, the display device 110 can be manually located using the signal coming from the emitter.
[0034] After receiving the emission, receptor 120 delivers it to an alignment processor (not shown) that can determine if the display device 110 is properly aligned with the screen 105 . After processing the received emission, the invention can then provide feedback whether the screen 105 and display device 110 are aligned. Such feedback can be provided by sound, visually through an indicator light or a display screen located on the display device 110 , or other feedback mechanism known to those skilled in the art. Using such an alignment system 100 , it may be easily determined whether display device 110 is properly aligned with viewing screen 105 .
[0035] The location of emitter and the receptor can be switched so that emitter 115 is included with display device 110 and the receptor 120 is included with screen 105 . In such a case, the screen could be manually located using the signal coming from the emitter of the display device 110 . The feedback mechanism could be easily provided on the housing 107 of screen 105 . Such a variation in the arrangement of alignment system 100 would not change the principles of operation thereof and such a modification would be understood by those persons having skill in the art.
[0036] Looking at FIG. 2 and FIG. 2A , the invention also discloses a device that facilitates the level installation of a viewing screen 205 , which includes a level device 225 .
[0037] Here, the screen 205 includes a housing 207 , which may or may not be motorized, on which the level device 225 is disposed. The level device 225 may comprise an indicator 230 and a pair of level lines 235 . The level device may operate like a typical level, wherein the level device indicates levelness by the location of the indicator 230 in relation to the level lines 235 . Generally, a level position is indicated when the indicator 230 is about centered between the level lines. Any other types of level devices, including but not limited to, laser level, could also be used.
[0038] Accordingly, when hanging a screen with level device 225 , an installer will know the screen is level because of the indication of levelness provided by the level device.
[0039] FIG. 3 and FIG. 4 show a similar approach to provide a level position indication when hanging a flat panel display on a wall.
[0040] A mounting bracket 300 is provided that includes a level device 325 . The bracket 300 has an interface (not shown) that is coupled with a flat panel display (not shown) at a predetermined mounting position thereon, which is suitable for adequately supporting the flat display device on a wall, for example. One or more brackets may be used depending on a number of factors, like the size of the display or the desired bracket size. Like the embodiment illustrated in FIG. 2A , the level device 325 includes an indicator 330 and level lines 335 that operate to indicate a level position similar to the level device 225 . Also, any types of level devices, including but not limited to a laser level, could be used.
[0041] The bracket 300 also includes mounting holes 307 that are adapted to receive a fastener 311 , like a screw, to fasten the bracket faceplate 303 securely against a wall or other supporting surface to support the weight of a flat panel display.
[0042] Here, the width of hole 307 is narrower than the head of fastener 311 and substantially the same width as the fastener body, but the height of hole 307 is elongated. The fastener 311 can be used with other structures, like a washer or a bolt, as well as other structures that are well-known in the fastening art, to assist the securing of the bracket. This arrangement allows the fastener 311 to securely fasten bracket 300 when the head of the fastener 311 is in contact with faceplate 303 to secure the bracket against the wall. This arrangement also allows the position of bracket 300 to be adjusted when the fastener 311 is loosened. Any other mechanisms that could make a small adjustment, including but not limited to, a bracket, a latch, or a hinge could be used.
[0043] As shown in FIG. 4 , the level device shows a non-level position. Because the mounting position on the display is designed to fit the bracket, then if the bracket 300 is level then the mounted display should also be substantially level. Thus, an installer may loosen a fastener 311 to adjust the bracket into a level position. One or more fasteners 311 may be loosened to allow the installer to adjust the faceplate 303 until the indicator 330 is between level lines 335 to indicate a level position. Subsequently, the installer may tighten the fasteners 311 to secure bracket 300 in a level position.
[0044] Accordingly, by providing a level position indicator with an adjustment mechanism, an installation of a flat display panel in a level position is facilitated. Once the bracket is installed level, the flat panel display could be attached to the bracket, using the attachment mechanism between the flat panel display and the bracket.
[0045] FIG. 5 illustrates a system for providing an adjustment for a display projector, wherein the adjustment aligns the projected display onto a viewing screen similar to the one illustrated in FIG. 1 . Here, the adjustment system 400 comprises a screen 405 and a display projector 410 , which comprises an image capture device 415 .
[0046] The image capture device 415 is mounted on the projector, which may be mounted from the ceiling or placed on a table top or located in a console. The angle of projection shown here is from the table top/console position. The angle of projection is inverted when projector is mounted from the ceiling. The dotted line illustrates the optical center of the projection lens of projector 410 . Here, projector 410 has a primary projection angle θ of 30 degrees in relation to the lens is shown, as wells as a secondary angle α of 5 degrees. These angles may vary and are used only for illustrative purposes.
[0047] The image capture device 415 , which is a camera here, captures the screen image and provides this image to an adjustment processor (not shown). The adjustment processor may process the screen image, as well as the actual image projected by projector 410 , and provide a signal adjustment to a lens shifter that will center the image in relation to the screen 405 both along a vertical axis (floor-to-ceiling) and a horizontal axis (wall-to-wall). The image capture device 415 and adjustment processor can be either an integral part of the projector 410 or added later.
[0048] Looking at FIGS. 5A, 5B , and 5 C, a separate device may also be provided in lieu or a lens shifter that moves the entire projector 410 so that the projected image is centered on screen 405 . For example a pod 420 on a table top/console could raise and lower the projector 410 using a projecting portion 425 to provide an adjustment along the vertical axis, and the pod could rotate or tilt (not shown) the projector 410 to provide an adjustment along the horizontal axis. FIG. 5A shows the projector 410 adjusted to a raised position 410 ′ (outlined by a broken line) to make a vertical adjustment. In addition, FIG. 5B shows the projector adjusted to as rotated position 410 ″ (outlined by a broken line) to make a horizontal adjustment.
[0049] For a projector 410 mounted from the ceiling, a telescopic post 430 could raise and lower the projector 410 using a telescopic portion 435 to provide the vertical axis adjustment, and the telescopic post could rotate the projector 410 to provide the horizontal axis adjustment. FIG. 5C shows the projector 410 adjusted to a lowered position 410 ′″ (outlined by a broken line) to make a vertical adjustment.
[0050] Moreover, as would be known to those of skill in the art, a combination of these elements could be used wherein, for example, the pod/post 420 or 430 is used for vertical axis adjustment and a lens shifter is used for horizontal axis adjustment. Also, user input such as a remote control device, for example, could be used to manually adjust the projected image to fit the screen.
[0051] Accordingly, using adjustment system 400 facilitates the orientation of a projected display on a viewing screen 405 .
[0052] FIG. 6 and FIG. 7 illustrate a removable installation apparatus 515 for installing a viewing screen or a flat panel display 505 at the same angle as the floor. FIG. 6A through FIG. 6D illustrate mounting a flat panel display using the removable installation apparatus.
[0053] Often floors are not level. Thus, if the display is truly “level,” it will not be level to the user's viewing angle because the viewer is standing or sitting on furniture resting on the non-level supporting surface like a floor. The installation device 515 addresses this by providing a reference to the floor angle during installation.
[0054] The removable installation apparatus 515 comprises a display supporting surface 517 and a floor stand 519 , which are parallel to one another. The floor stand 519 rests on floor 520 to align the display supporting surface 517 on the same angle as the floor 520 . Then the display 505 or bracket 503 can rest on the display supporting surface 517 during installation of display 505 onto a mounting surface like a wall 530 using bracket 503 . The bracket 503 may include a similar arrangement as the bracket illustrated in FIG. 3 to permit an adjustment of the display's 505 mounting position.
[0055] FIG. 6A shows bracket 503 resting on display supporting surface 517 of installa, while bracket 503 is secured to the wall 530 using fasteners 511 inserted through bracket holes 507 . The display supporting surface 517 has a very narrow depth so that the installation apparatus 515 does extend too far from the wall 530 . FIG. 6B shows the bracket 503 secured in place, wherein a bottom surface of the bracket 503 is arranged on a plane substantially parallel to the plane of the display supporting surface 517 , the portion of floor stand 519 resting on floor 520 , and the floor itself. In an integrated structure, the brackets are fixed to the wall in parallel with the floor surface, once the integrated structure stands again the wall. Then, the lower part can be removed except for the bracket. The lower part may also be left place and used for shelving and other purposes. FIG. 6C shows that the removable installation apparatus 515 can be removed because the bracket 503 is secured to wall 530 by fasteners 511 . FIG. 6D shows the display device 505 mounted on the bracket 503 using a pre-set mounting position of the display 505 adapted for the bracket 503 . The bottom edge of the display 505 is substantially parallel to the bottom edge of the bracket 505 , and thus is substantially parallel to the floor 520 .
[0056] Alternatively, the bracket 503 can be coupled to the installation apparatus 515 , or formed integrally therewith, to form a unitary bracket/installation apparatus. In this arrangement, the display supporting surface 517 can be eliminated but the reference angle to floor 520 is still provided because the bracket is coupled to the floor stand 519 resting on the floor. As a result, the bracket portion is disposed at an angle substantially the same as the angle of the floor, which orients the display device at the angle of the floor as well.
[0057] As can be seen in FIG. 7 , the level plane is designated at a plane L. But display supporting surface 517 or display bracket 503 is disposed on a plane L″ that is at the same angle as the plane L′ of floor 520 and floor stand 519 . The bottom of display 505 will also be disposed along L″ when it is supported on the installation stand 515 or attached to the bracket 503 . After the display 505 is mounted on wall 530 , the installation apparatus 515 can either be removed or left in place as furniture to hold other multimedia components, home decor, or the like. The apparatus 515 is no longer needed to support the display 505 since it is mounted on the wall 530 with brackets 503 . Because the display supporting surface 517 or the bracket 503 is on the same angle as the floor 520 , the display will be oriented at the same angle as the user's viewing angle.
[0058] FIG. 8 and FIG. 8A show a lowered viewing screen 205 used with a flat panel display 505 , while FIG. 9 and FIG. 9A illustrate a raised viewing screen 205 disposed in motorized housing 207 used with a flat panel display 505 . The viewing screen 205 may have a level device 225 as illustrated in FIG. 2 .
[0059] A user may want to use different types of displays depending on the video source and the viewing conditions. For example, a viewer may want to use the viewing screen 205 at night or for movies, while the user may want to use the flat panel display 505 during the day or for television programs. FIG. 8 shows that the flat panel display 505 (outlined by the broken line) can sit behind the viewing screen 205 when a projection display device is used, FIG. 8A shows a clearance between the viewing screen 205 and flat panel display 505 . FIG. 9 and FIG. 9A , show the screen 205 can be easily raised when the user wishes to view the flat panel display 505 .
[0060] As noted above the installation apparatus 515 requires a narrow depth so as to not extend too far from the wall 530 . This may be necessary so that it will not interfere with screen 205 if the removable installation apparatus 515 is not removed after installation of the flat panel display 505 .
[0061] While the present invention has been described in detail above with reference to specific embodiments, those skilled in the art will appreciate that various modifications and substitutions can be made thereto without departing from the spirit and scope of the present invention as defined in the appended claims. | A device and method for arranging a display allows for the easy installation of a display in a home entertainment system. The flexibility of modern home entertainment/theater systems that include a digital display device permits many different installation options. Thus, the invention facilitates the installation of such a display by aligning a viewing screen with a projector device. Moreover, the invention allows the installation of a flat panel display, such as an LCD or PDP, at a proper viewing angle. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of a U.S. Provisional Application (Attorney Docket No. 5490-000468) filed on Mar. 3, 2005. The disclosure of the above application is incorporated herein by reference.
FIELD
[0002] This invention relates to acetabular shells and more particularly to a method of making an implant such as an acetabular shell by free form plasma (thermal) spray technology.
INTRODUCTION
[0003] In replacement hip surgery a femoral component can be inserted into the prepared femur. The femoral component can include a stem portion which projects into the femoral canal of the prepared femur and has an integral or separate modular head of substantially spherical shape. The ball-like head of the femoral component is received within an acetabular cup component which is implanted in the patient's hip socket, i.e., the acetabulum. The acetabular cup has a substantially hemi-spherical bearing surface for movement of the ball head of the femoral component during action of the joint.
[0004] Various designs of acetabular cups are available and it is often a multi-piece component having at least a separate outer shell and an inner liner. Where the acetabular cup has an inner liner, that inner liner is generally press-fitted into the outer shell. In some designs of hip prostheses the material of the bearing surface of the acetabular cup, e.g. its inner liner where present, is of the same material as that of the ball head, e.g. for a ceramic head, a ceramic bearing surface is provided (a so-called ceramic-on-ceramic prosthesis) and for a metal head, a metal bearing surface is provided (a so-called metal-on-metal prosthesis). In some other designs, the acetabular bearing surface is of polyethylene, as the acetabular cup is either provided with a polyethylene inner liner or the acetabular cup is a single component made entirely from polyethylene. The shape of the bearing surface into which the ball head is received affects the degree of movement available after implantation of the joint.
SUMMARY OF THE INVENTION
[0005] A method for forming an implant includes providing a working surface such as a mandrel, and spraying the working surface with a first layer of material having a first composition such as aluminum oxide. After a suitable thickness is generated, the spray composition is gradually changed to other compositions having desired particle sizes and distribution. In one example, the composition is changed to a mixture of aluminum oxide and titanium oxide and/or titanium. As thickness builds up, the relative amount of aluminum oxide is decreased such that the composition is all titanium and titanium oxide. After a desired thickness is generated, the acetabular shell is extracted off the mandrel.
[0006] A method of making an implant according to various features includes forming a ceramic shell having a first surface and a second surface. A first surface of the ceramic shell is located onto a mounting instrument. A layer of material is sprayed onto the second surface of the ceramic shell. The ceramic shell is then sintered.
[0007] 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 embodiments 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
[0008] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0009] FIG. 1 illustrates an exemplary thermal spraying device spraying a first layer of material onto a mandrel;
[0010] FIG. 2 illustrates a cross-sectional view of the mandrel of FIG. 1 ;
[0011] FIG. 3 illustrates a partial cross-sectional view of the spraying device and mandrel of FIG. 1 shown during an initial spraying step;
[0012] FIG. 4 illustrates the cross-sectional view of FIG. 3 , shown during an intermediate spraying step;
[0013] FIG. 5 illustrates the cross-sectional view of FIG. 4 shown during spraying of an outboard porous layer;
[0014] FIG. 6 illustrates the acetabular shell removed from the mandrel;
[0015] FIG. 7 illustrates a cross-sectional view of the acetabular shell of FIG. 6 ;
[0016] FIG. 8 illustrates a perspective view of a ceramic casting according to a another embodiment;
[0017] FIG. 9 illustrates a perspective view of a ceramic shell removed from the casting of FIG. 8 ;
[0018] FIG. 10 illustrates a perspective view of the ceramic shell arranged on a mandrel and a spraying device spraying a layer of material onto an outer concave surface of the ceramic shell;
[0019] FIG. 11 illustrates a cross-sectional view of the ceramic shell having the layer of material sprayed thereon and defining an acetabular shell; and
[0020] FIG. 12 illustrates the acetabular shell of FIG. 11 shown during a sintering process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Moreover, while the description below is directed to an acetabular shell, the teachings described herein may similarly be employed to form other implants, such as, but not limited to femoral implants, tibial implants, tibial trays, and glenoid implants.
[0022] With initial reference now to FIGS. 1 and 2 , a thermally stable mandrel and plasma spraying device are shown and identified at reference 10 and 12 respectively. The mandrel 10 generally defines a semi-hemispherical dome 14 and a longitudinal support portion 16 . While the mandrel 10 and spraying device 12 are shown having specific geometries, it is appreciated that they are merely exemplary and other mandrels and spraying devices may be similarly employed.
[0023] The mandrel 10 is generally shaped inversely to a desired acetabular shell. More specifically, the mandrel 10 defines the semi-hemispherical dome 14 providing an outer convex surface 20 that corresponds to an inner concave surface of the acetabular shell. In one example, the thermally stable mandrel 10 may be made of tungsten. The outer convex surface 20 may be polished to a roughness acceptable for articulating surfaces of acetabular shells. The thermally stable mandrel 10 allows the generation of multiple acetabular shells without the need of individual grinding and polishing operations between subsequent shell formations.
[0024] With specific reference to FIG. 2 , the mandrel 10 may be mounted on a holding fixture 22 . The holding fixture 22 may provide a bearing set 26 for rotational capability. Other arrangements may also be provided.
[0025] The mandrel 10 may define a coolant channel 28 for communicating a coolant (not specifically shown) from an inlet 30 defined on the longitudinal portion 16 to an outlet 32 defined on the longitudinal portion 16 . As shown, the coolant channel 28 is adapted to communicate fluid through the longitudinal portion 16 , around the semi-hemispherical portion 14 and back through the longitudinal portion 16 . The coolant port arrangement on the mandrel 10 helps draw away heat to maintain an acceptable temperature on the outer convex surface 20 and the mandrel 10 as a whole during a spray event. It is appreciated that the coolant channel 28 may be arranged differently on the mandrel 10 and/or other cooling mechanism or techniques may be employed to maintain acceptable mandrel temperatures during use. In one example, the mandrel 10 is maintained under 200° C. Other temperatures are contemplated. In addition, while not specifically shown, heat removal may be accomplished by flow of external gases over the acetabular shell being created.
[0026] With continued reference to FIGS. 1 and 2 and additional reference to FIG. 3 , a method of making an acetabular shell according to the present teachings will be described. In a controlled atmosphere, very fine powder of aluminum oxide 38 is sprayed onto the mandrel 10 such that a continuous layer of aluminum oxide 38 is generated on the mandrel 10 on the outer convex surface 20 . The very fine powder exhausted from the spraying device 12 may be in the molten, or semi-molten state. In one example, prior to applying the aluminum oxide 38 , a mold relief agent may be applied to the mandrel 12 to facilitate removal of the acetabular shell once completed.
[0027] Once a suitable thickness (such as, but not limited to, less than 5 mm) of aluminum oxide 38 is sprayed onto the mandrel dome 14 , the spray concentration changes to a mixture of aluminum oxide and titanium oxide and/or titanium collectively identified at reference 40 ( FIG. 4 ). After a suitable thickness is generated (such as, but not limited to, 5 mm), the proportions of aluminum oxide is reduced causing the composition of titanium oxide and/or titanium to increase. This layer is identified at reference 42 ( FIG. 5 ). The thickness of layer 42 may be 3 mm, although other thicknesses are contemplated.
[0028] Concurrently, the particle size of the titanium oxide and/or titanium may be increased to generate a porous outer surface. It is understood that while unique reference numerals 38 , 40 and 42 have been used to identify sequential layers of sprayed material, the relative proportions of aluminum oxide, titanium oxide and/or titanium in the sprayed material gradually change as desired. As a result, there is not necessarily any identifiable transition boundaries across the thickness of the sprayed material.
[0029] Turning now to FIG. 6 , once a suitable thickness is achieved (such as, but not limited to, 13 mm), a newly formed acetabular shell 50 is extracted off the mandrel 10 . The resulting acetabular shell 50 provides an inner portion 52 having a concave inner surface or articulating surface 54 of aluminum oxide, an intermediate portion 58 comprising a ceramic composition changing from aluminum oxide (from the articulating surface 54 ) to titanium and titanium oxide and finally to an outer portion 60 comprising porous titanium. The articulating surface of the acetabular shell 50 may then be polished to a desired roughness to serve as an articulating surface. It is appreciated that other materials may be used. For example, zirconia and/or other materials may be used for the aluminum oxide. Likewise, any composition of cobalt, chromium and/or molybdenum may be used for the titanium oxide and/or titanium. In addition, the acetabular shell may alternatively be made exclusively of one material.
[0030] In another embodiment, an implant such as a stem may take the place of the mandrel 10 . As a result, the sequential layers may be sprayed directly onto the implant and remain on the implant as an integral feature.
[0031] Turning now to FIGS. 8-12 , a method of making an acetabular shell according to an additional embodiment will be described. In this embodiment, rather than forming all layers of an acetabular shell by way of plasma spraying, a prefabricated ceramic shell 68 ( FIG. 9 ) is used to define a template for receiving a subsequent plasma spray.
[0032] As shown in FIG. 8 , a ceramic shell 70 may be formed by way of a casting process. In one example, a first and second die 72 and 74 are used to define a desired outboard surface 76 and an inboard articulating surface 78 of the ceramic shell 70 ( FIG. 9 ). As illustrated in FIG. 8 , the first die 72 defines a concave cavity 80 and the second die 74 defines a convex extension surface 82 . The concave cavity 80 defines a plurality of outward knobs 86 . The outward knobs 86 are operable to define a textured surface, represented as dimples 90 on the outboard surface 76 of the cast ceramic shell 68 ( FIG. 9 ). The convex extension surface 82 is operable to define the inboard articulating surface 78 of the cast ceramic shell 68 . In one example, the walls of the concave cavity 80 are coated with titanium powder such that a layer of titanium is defined on outboard surface 76 of the cast ceramic shell 68 .
[0033] During the casting process, a slurry of ceramic 92 is delivered to the first and second die 72 and 74 . In one example, the slurry of ceramic 92 may be created in a fluid with binders and deflocculating agents as desired. The particle size of the ceramic, the quantity of binder and deflocculating agents and the ratio of various components in the slurry may be adjusted to achieve a slurry providing favorable casting properties. While the respective die cavities 72 and 74 are shown in an open position in FIG. 8 , it is appreciated that the slurry of ceramic 92 may be delivered through a port to a closed die cavity.
[0034] As shown in FIG. 9 , the ceramic shell 68 defines a hemispherical dome 96 . It is appreciated that other shapes may be alternatively formed. It is further appreciated that while the textured surface is depicted as dimples 90 , the first die 72 may be configured to define any textured surface including, but not limited to, ridges, notches and other configurations. Furthermore, while the formation of the ceramic shell 68 has been described by way of a casting process, other fabrication techniques may be used. Once the ceramic shell 68 has been cast, the ceramic shell 68 is dried or semi-dried into a stable dome 98 . In one example, the process of converting the ceramic shell 68 to a semi-dried, stable dome 98 may be achieved in a baking oven 100 . The baking oven 100 is operable to drive off any excess fluid slurry. Furthermore, any binders and/or deflocculating agents may or may not be removed.
[0035] Turning now to FIG. 10 , the stable dome 98 may be placed onto a mandrel 110 . The mandrel 110 may cooperate with a longitudinal support portion 116 , a holding fixture 122 and a bearing set 126 . Furthermore, the mandrel 110 may include a coolant channel 128 . Again, other configurations may be employed.
[0036] Next, a layer of titanium oxide 140 is sprayed with a plasma sprayer 12 to a desired thickness. As best illustrated in FIG. 11 , mechanical interlocking is achieved between the titanium oxide 140 and the outboard textured surface 90 of the ceramic dome 98 . The interface between the textured surface 90 and the titanium oxide 140 resists torsional slippage and radial slippage of the titanium oxide 140 relative the outboard surface 76 of the ceramic dome 98 .
[0037] With reference now to FIG. 12 , a newly formed acetabular shell 150 is then placed into a baking oven 100 for a sintering process. In one example, a sinter cycle may be performed as follows. First, the oven temperature may be raised to 175° C. at 5° C./min. The 175° C. may be maintained for 4 hours. The temperature may be ramped to a peak temperature such as 1650° C. at 5° C./min (optionally lower temperatures may be used i.e. 1300° C.-1450° C.). The peak temperature may be maintained for 8 hours. It is appreciated that a peak temperature of 130° C.-1450° C. may be maintained for longer periods than higher temperatures (such as 1650° C.). The temperature may be ramped down to 600° C. at 5° C./min. The 600° C. temperature may be held for 30 minutes.
[0038] It is appreciated that the sintering procedure explained above is merely exemplary. As such, ramp rate, dwell time and dwell temperatures (collectively referred to as variables) of the sinter cycle may define other ranges. The variable assigned during the sinter process may be chosen to discourage crack formation in the structure. In one example, a thermally induced compressive stress may be generated in the ceramic structure to discourage premature failure.
[0039] Once the acetabular shell 150 is sintered, the concave inner surface 78 may be polished to a desired roughness to serve as an articulating surface.
[0040] While the invention has been described in the specification and illustrated in the drawings with reference to various embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various embodiments is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless described otherwise above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the foregoing description and the appended claims. | A method for forming an acetabular shell includes providing a working surface such as a mandrel, and spraying the working surface with a first layer of material having a first composition such as aluminum oxide. After a suitable thickness is generated, the spray composition is gradually changed to other compositions having desired particle sizes and distribution. In one example, the composition is changed to a mixture of aluminum oxide and titanium oxide and/or titanium. As thickness builds up, the relative amount of aluminum oxide is decreased such that the composition is all titanium and titanium oxide. After a desired thickness is generated, the acetabular shell is extracted off the mandrel. | 0 |
BACKGROUND OF THE INVENTION
The subject invention relates to data communication apparatus and, more particularly, to an improved circuit for adjusting the timing of a sampling clock typically used to recover data in the receiver of a data modem. Precise adjustment of the sampling clock is essential to optimum recovery of data.
In the prior art, it has been suggested to derive a clock correction signal by correlating so-called main channel error signals and derivative channel signals. The derivative channel signal is derived by differentiating the main channel (received) signal. According to this suggestion, the derivative channel signals must be determined every baud interval and must be equalized by a second equalizer identical to the equalizer employed to equalize the main channel signal. Furthermore, the technique assumes that the sampling clock has already been set to near the correct sampling point. While theoretically interesting, this prior art technique has not appeared practically implementable because of the complexity involved, such as in providing a second equalizer identical to that utilized to equalize the received signal. The prior art technique proves particularly undesirable in modems employing microprocessor techniques because of the excessive number of operations required, which waste valuable microprocessor computation power.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an improved technique for properly adjusting the sampling point of a sampling clock employed in a data modem.
It is a further object of the invention to provide a practically implementable sampling clock correction circuit which employs correlation of a main channel error signal and a second channel signal.
It is yet another object of the invention to provide such a sampling clock correction circuit implementable in a microprocessor modem design.
According to the subject invention, the number of operations necessary to perform sampling clock correcting functions is dramatically reduced by the discovery that it is not necessary to completely equalize the second channel signal, and that the equalized second signal need not be determined every baud interval. Furthermore, the subject invention employs an initial phase estimate based on the signal envelope to initially estimate the positioning of the sampling clock and establishes that such an estimate is sufficient to enable employment of the precise adjustment technique employed. This initial estimate proves very important in that otherwise very poor system performance may result. Employment of a second order phase lock loop to compensate for frequency offset provides a further improvement according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a portion of a main channel distortion removing apparatus including a main channel equalizer according to the preferred embodiment of the invention.
FIG. 2 is a schematic diagram of the remainder of the apparatus of FIG. 1.
FIG. 3 is a schematic diagram of a second channel distortion removing apparatus including a second channel equalizer according to the preferred embodiment.
FIG. 4 is a schematic diagram of correlation and phase lock structure for producing a timing correction signal according to the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment of the invention, a main channel equalizer illustrated in FIG. 1 and FIG. 2 is employed to generate main channel error signals EX n and EY n . The main channel equalizer structure of FIG. 1 and FIG. 2 is well known in the art, and is illustrated in brief schematic form.
Input samples X n+K and Y n+K of the main channel received signal, having a phase quadrature relationship, are employed. Initially it is necessary to set the sampling point near the appropriate point in order to enable proper operation of the preferred embodiment. Such initial setting of the sampling clock may be achieved by known envelope recovery methods or by the preferred technique disclosed in the copending application of the inventors U.S. Ser. No. 900,265, entitled Fast Learn Digital Adaptive Equalizer, filed Apr. 26, 1978 and assigned to Racal-Milgo, Inc., herein incorporated by reference. Once the timing of the sampling clock has been initially set, the preferred embodiment will proceed to precisely locate the sampling time in order to optimize data recovery.
The equalizer of FIG. 1 includes an in-phase channel for the X n+K samples, and a quadrature phase channel for the Y n+K samples. The samples X n+K are stored in delay elements 11 and the samples Y n+K are stored in delay elements 13. The inphase channel samples X n+K are multiplied by respective constants CP -K . . . CP m and summed in a summer 15. The samples Y n+K are also multiplied by respective constants CS -K . . . CS m and summed in a summer 17. The outputs of the two summers 15 and 17 are summed by a summer 19 to provide the signal X EQ .sbsb.n. The output of the summer 19 X EQ .sbsb.n is fed to a phase correction circuit 21. Similarly, the samples X n+K are multiplied by respective constants CS -K . . . CS m and the resulting products are summed in a summer 23. The samples Y n+K are multiplied by respective constants CP -K . . . CP m and the resulting products are summed in a summer 25. The respective outputs of the two summers 23, 25 are summed by a summer 27 to produce the signal Y EQ .sbsb.n. This signal Y EQ .sbsb.n is then fed to the phase correcting circuit 21. The output X EQ .sbsb.n, Y EQ .sbsb.n of the phase correcting circuits are the equalized main channel signal components:
X.sub.EQ.sbsb.n =X.sub.EQ.sbsb.n COS θ.sub.n +Y.sub.EQ.sbsb.n SIN θ.sub.n
Y.sub.EQ.sbsb.n =Y.sub.EQ.sbsb.n COS θ.sub.n -X.sub.EQ.sbsb.n SIN θ.sub.n
where θ n represents the necessary phase angle correction.
The phase corrected equalized main channel signals X EQ .sbsb.n and Y EQ .sbsb.n are then fed to respective decision circuits 29, 31 (FIG. 2). Each decision element 29, 31 decides the correct value of the output data signal DX n , DY n from the respective raw outputs X EQ .sbsb.n, Y EQ .sbsb.n of the equalizer. The data signal values DX n , DY n are then fed to the respective summers 33, 35 from which the main channel in-phase error component EX n and the main channel quadrature phase error component EY n are derived.
As known in the prior art, the equalizer constants CP -K and CS -K , etc., are adjusted according to some algorithm in order to produce equalized output signals to remedy the effects of intersymbol interference. Such algorithms are well known in the art and will not be discussed further herein.
FIG. 3 discloses the second channel equalizer of the preferred embodiment which in the preferred embodiment is a derivative channel equalizer. Generation of the input signal X' n+v , Y' n+v to the derivative channel equalizer is very well known. For example, if X n and Y n are the sampled in-phase and quadrature phase baseband signals, then X' n and Y' n are the corresponding sampled derivatives of these baseband signals. These samples are then fed to the respective delay elements 15, 17 of the equalizer, shown in FIG. 3, which differs in structure from the equalizer of FIG. 1 in the sole but significant respect that, according to the invention, the number of taps and tap constants CP -V . . . CP W and CS -V . . . CS W in FIG. 3 is less than the number of taps required by the equalizer of FIG. 1 to equalize the main channel received signal. The values of the tap constants CP, CS for corresponding taps of FIG. 1 and FIG. 3 are the same. By using fewer taps, i.e., V≦K, W<M or V<K, W≦M, the derivative signals X EQ .sbsb.n and Y EQ .sbsb.n, are not as precisely calculated and are typically in error to an extent not tolerable in the main channel received signal. However, according to the invention, it has been found that high accuracy is not required in these signals, whereas high accuracy is required in the output data DX n and DY n . As a particular example, in a modem constructed according to the preferred embodiment, main tap to derivative tap numbers of 23 to 17, 30 to 19 and 39 to 26 were found to provide accurate operation.
Moreover, according to the invention, it has also been found unnecessary to determine the signal X EQ .sbsb.n and Y EQ .sbsb.n every baud. In the preferred embodiment these values and hence the values of X EQ .sbsb.n and Y EQ .sbsb.n are calculated once every other baud only, using a subset of the tap constants determined for the main channel equalizer of FIG. 1.
The correlation and phase lock structure employed to utilize these approximately-calculated derivative signals X EQ .sbsb.n and Y EQ .sbsb.n is illustrated in FIG. 4. The derivative signals X EQ .sbsb.n and Y EQ .sbsb.n are multiplied together with the respective error components of the main channel EX n and EY n in the respective multipliers 51, 53. The respective products EX n X EQ .sbsb.n and EY n Y EQ .sbsb.n are then summed in a summer 55 to produce a signal φ n representative of the clock error.
The output φ n of the correlator is then applied to a second order loop filter. The second order loop filter includes summers 57, 65 a delay element 59, and constant multipliers 61, 63. The output of summer 57 is denoted φ n and is delayed by the delay element 59 whose output is fed back as one input to the summer 57. The summer 57 sums φ n with the delayed value φ n-1 provided by the delay element 59 to provide φ n . The multiplier 61 multiplies φ n by a loop constant B. A multiplier 63 also multiplies φ n by a loop constant A to produce Aφ n . The loop constants A and B are chosen according to well-known phase lock loop design considerations. A summer 65 then sums Aφ n and Bφ n and produces an output ψ n . The elements 57, 59 and 61 cooperate to provide a second order loop characteristic and eliminate frequency offset between transmitter and receiver clocks.
Another summer 67 forms an output P n =ψ n +ψ n-1 by summing one input ψ n with the output ψ n-1 of a delay element 69. The output P n is fed to a decision block 71 where [P n /α]·α is determined. The constant α is the smallest adjustment increment or decrement that can be made to the sample clock phase with the given hardware comprising a clock generator 73, and [P n /α] represents the integer portion of P n divided by α. Thus, [P n /α]·α provides an integer number of increments or decrements for sample timing correction.
The remainder or non integer portion is determined by the quantity ψ n =P n -[P n /α]·α. This remainder portion ψ n is stored in the delay element 69 and combined with the next input to the summer 67 in order to provide more accurate sampletime adjustments.
As may be appreciated, since equalized derivative values X EQ .sbsb.n and Y EQ .sbsb.n are provided only once every other baud, the circuitry of FIG. 4 need only operate on a once per every other baud timing basis. Thus, the subscripts "n" as used in FIG. 4 indicate the value of the corresponding variable during one particular alternate baud period.
The preferred embodiment just described is admirably suited for a microprocessor modem environment where computation power is at a premium. By utilizing fewer taps, the number of multiplications and summations necessary to calculate X EQ .sbsb.n and Y EQ .sbsb.n are significantly reduced. By further limiting the calculations to once every other baud, the number of calculations is effectively cut in half. As a consequence of the preferred embodiment, the number of calculations required to implement FIG. 4 is also cut in half. All of these savings are made at no significant sacrifice to the ultimate accuracy of the timing correction provided.
As will be apparent to those skilled in the art, many modifications and adaptations of the just described preferred embodiment may be made without departing from the scope and spirit of the invention. Therefore, it is to be understood that, with the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A circuit for maintaining proper sampling timing in a data modem wherein main channel equalizer error is correlated with a derivative channel signal to drive a clock correction signal. The derivative channel signal is derived from an equalizer using fewer coefficients than required to derive the main channel equalized signal, and calculation of the equalized derivative and clock correction signal is performed only once every other Baud. | 7 |
FIELD OF THE INVENTION
This invention relates to power and energy consumption in computer systems.
BACKGROUND OF THE INVENTION
Power/energy consumption has increased significantly with every chip generation. With the reduced transistor sizes in modern processors, the per area power density is approaching that of a nuclear reactor. Consequently, power reduction has become a design goal, with power saving features widely recognized as representing the next phase in the advancement of microprocessors. Portability and reliability requirements of emerging applications further underline this trend.
Major processor vendors realize that they must compete in terms of the power consumption of their chips as well as chip speed. Typical approaches to reduce power consumption (e.g., by reducing supply voltage and/or clock rate) negatively impact performance. Other approaches do not scale between design generations (e.g., as clock rates increase, due to changed critical paths, the value of many circuit or microarchitecture based energy reduction approaches is reduced).
The challenge is to reduce the energy consumed in processors without sacrificing performance, and with solutions that scale between processor generations. With increased Internet usage and growing desire for wireless communications, the processor market is being driven to produce smaller and more powerful chips that do not drain significant amounts of power.
SUMMARY OF THE INVENTION
The aforementioned problems are addressed by the present invention. The concepts introduced are broad and present chip-wide energy reduction optimization opportunities. The particular embodiments described provide application adaptive and scalable solutions to energy-reduction in memory systems.
A wide-range of compiler and microarchitectural techniques are presented, that improve the energy efficiency of processors significantly, without affecting performance (in many cases performance can be improved). The scope of the invention includes, but is not limited to, both embedded as well as general-purpose processor designs.
In the methods described, energy consumption is reduced by (1) extracting and exposing static information to control processor resources at runtime, (2) exploiting speculative static information in addition to predictable static information, and (3) adding compiler managed static and static-dynamic execution paths (i.e., architectural components), that can also be integrated into conventional mechanisms and that leverage this static information.
Speculative compiler analysis, as an underlying compilation approach, reduces the complexity of otherwise highly sophisticated analysis techniques (e.g., flow-sensitive and context-sensitive alias analysis), and expands their scope to large and complex applications.
The methods presented are based on a combined compiler-microarchitecture approach, and, more specifically, statically speculative compilation and execution, and provide a unified and scalable framework to reduce energy consumption adaptively, with minimal or no performance impact, or performance improvement for many important applications (e.g., image compression and video processing).
The invention can be used to save energy on any type of device that includes a processor. For example, the invention can be used to save energy on personal computers, devices containing embedded controllers, and hand-held devices, such as PalmPilots and cellular telephones.
In general, in one aspect, the invention is a method, for use with a compiler architecture framework, which includes performing a statically speculative compilation process to extract and use speculative static information, encoding the speculative static information in an instruction set architecture of a processor, and executing a compiled computer program using the speculative static information. Executing supports static speculation driven mechanisms and controls. This aspect may include one or more of the following features.
Executing may include controlling at least some processor resources using the speculative static information encoded in the instruction set architecture. Executing may include operating processor-related mechanisms using the speculative static information encoded in the instruction set architecture. Executing may include static, static-dynamic, and dynamic execution paths. The speculative static information may include information about one or more of processor resource demands and information that contributes to determining processor resource demands.
The instruction set architecture may include at least one of modified and additional instructions to propagate information through code and to store the information. The compilation process may expose speculative static information to run time layers, and the microarchitecture which performs the executing may provide a mechanism to recover in case of static misprediction. The compilation process may extract the speculative static information and performs compilation using the speculative static information to reduce power consumption in the processor. The speculative static information may include predictable static information and additional static information that is speculated based on the predictable static information.
Executing may be performed by microarchitecture that contains an extension. The extension may support correctness of execution for performing the statically speculative compilation process. The extension is comprised of hardware and/or software.
The compilation process may perform static speculation. The static speculation determines information about execution of the computer program. The static speculation may be controlled on an application-specific and adaptive basis and may be managed with compile-time flags. The compilation process may determine processor performance and energy tradeoffs during compile-time and may use the tradeoffs during execution. The compilation process may perform design objective customization without changing the microarchitecture.
More information about processor resource usage is exposed with speculative static compilation than with predictable static information. The microarchitecture may perform the executing using the speculative static information and dynamic information during execution.
This aspect may be used in a silicon-based electronics system, a nano-electronics based electronic system, or any other appropriate system.
In general, in another aspect, the invention is directed to a processor framework that includes a compiler which compiles a computer program, the compiler extracting speculative static information about the computer program during compilation, and a tagless cache architecture that is accessed based on the extracted speculative static information. This aspect may include one or more of the following.
The speculative static information may be used to register promote cache pointer information. The speculative static information may be used to select cache pointers at run time. The processor framework may also include at least one of a scratchpad-memory based cache mechanism and an associative cache.
The compiler may select which of plural cache accesses are mapped to which cache mechanisms based on the speculative static information. Frequently used data with a low memory footprint may be mapped to the scratchpad-memory based cache mechanism. Associativity and block size in the tagless cache may be logical and programmable. The compiler may determine block sizes and associativity of a cache based on an analysis of the computer program.
The processor framework may include a memory area for storing a cache pointer. The processor framework may include a Cache TLB (Translation Look-ahead Buffer) for capturing statically mispredicted cache pointers and other types of cache pointers. The Cache TLB may include eight entries. The processor framework may include a microarchitecture for use in accessing the tagless cache. The microarchitecture may access the tagless cache using at least one of static, static-dynamic, and dynamic cache access paths.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiment thereof in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a Tag-less (tagless) Cache architecture, which is an example implementation of the microarchitecture described in the first embodiment.
FIG. 2 is a block diagram of cache organizations with address translation moved towards lower levels in the memory hierarchy, STLB is the translation buffer between L1 and L2 caches, and MTLB is the translation buffer added between L2 cache and main memory.
FIG. 3 is a block diagram of a baseline memory system, where all accesses require address translation, multi-way cache access, and tag-checks.
FIG. 4 is a block diagram showing an example of implementation of the microarchitecture in the 2 nd embodiment.
FIG. 5 is a flow diagram of an embodiment of the compilation process.
FIG. 6 is a diagram for alternative pointer representations: (a) program-point representation, (b) through global information.
FIG. 7 is a diagram representing CFG and PTG graphs derived for a simple C program.
FIG. 8 is a diagram representing a simple loop-based example analyzed with traditional flow-sensitive AA (top) and the SAA method (bottom), that shows that SAA achieves higher precision by removing all weak point-to relations after each merging-step, where the weak point-to relations are shown with dotted arrows.
FIG. 9 is a diagram showing the accuracy of static speculation for one set of parameters suing the industry standard CPU2000 and Mediabench benchmarks.
FIG. 10 is a diagram showing chip-wide energy reduction due to reduction in memory consumption obtained with the microarchitecture in the second embodiment as compared to an Alpha 21264 processor.
FIG. 11 is a list of programs evaluated with the embodiments described herein.
DETAILED DESCRIPTION
The problem of energy reduction without performance impact is addressed by the present invention. Power and energy consumption are reduced by methods incorporated at compile-time and at runtime, in both hardware and software layers. The methods include compiler level, instruction set architecture (ISA), and micro-architectural components/techniques.
A compiler is software (i.e., machine executable instructions stored in a memory system) that translates applications from high-level programming languages (e.g., C, C++, Java) into machine specific sequences of instructions. The ISA is a set of rules that defines the encoding of operations into machine specific instructions. A program is a collection of machine level instructions that are executed to perform the desired functionality. Micro-architectural (or architectural) components refer to hardware and/or software techniques that are used during execution of the program. The actual machine can be a microprocessor or any other device that is capable of executing instructions that conform to the encoding defined in the ISA. A memory area can be any area that can store bits, e.g., registers, cache, and some type Random Access Memory (RAM).
Compile-time refers to the time during which the program is translated from a high level programming language into a machine specific stream of instructions, and it is not part of the execution or runtime. Runtime is the time it takes to execute the translated machine instructions on the machine. Machine energy in the targeted apparatus is only consumed during runtime. Compilation is typically done on a different host machine.
Information in the context of this invention refers to either information collected during compilation or during execution. Information collected during compilation is called static or compile time information. Information collected during runtime is called runtime or dynamic information. Program analysis refers to the process during compile time that analyzes the program and extracts static information. Program transformation/optimization is the process during compile time that modifies the program typically to achieve some objective such as improve performance.
Static information is defined to be predictable if it can be shown during compilation that the information is true for any possible input set applied to the program, or for any possible execution of the program on the machine in question. Static information is defined to be speculative if the information extracted during compile time is not shown or cannot be shown to be true for all possible execution instances. As such, the available (i.e., extractable) speculative static information is a superset of the available predictable static information in a program.
An energy optimization is called dynamic if it uses dynamic information. It is called static if it uses static information.
The methods described herein address opportunities that appear at the boundary between compile-time and runtime layers in computer systems, in addition to techniques that can be isolated to be part of either compile-time or runtime components. The methods combine architecture and compiler techniques into a compiler-enabled, tightly integrated, compiler-architecture based system design. The approach is called compiler-enabled if the execution of specific instructions is managed to some extent by static information.
This has the benefit of that in addition to dynamic techniques, static and static-dynamic energy reduction optimizations can be enabled. Additionally, the information exposed to runtime layers can be made available much earlier in the processor execution (pipeline), enabling energy reduction without negatively impacting execution latencies.
In general, there are two main ways the methods presented herein achieve energy reduction, without significantly affecting performance (for several applications studied performance has been improved): (1) redundancies in instruction executions are either eliminated or reduced, and (2) execution paths are simplified based on modified and/or new micro-architectural components. In both (1) and (2) the methods are leveraging various type of static information and/or dynamic information about resources used and/or resources (likely) needed, and/or information that can be used to estimate the resources likely to be used.
The methods leverage static program information in smart ways, and expose static resource utilization information for a particular application, to runtime layers. The apparatus extracts and leverages this information in a speculative manner, in both compiler and architecture components, i.e., in the new methods a superset of the predictable program information can be used.
The methods implement compiler analysis and micro-architectural techniques that enable the extraction and utilization of speculative static information without affecting correctness of execution. The methods also enable various degrees of static speculation (i.e., the extent to which information extracted is expected to be true during execution), to control the accuracy of static speculation.
Static speculation can be controlled on an application specific/adaptive basis and managed with compile-time flags. This provides unique post-fabrication (compile-time) customization of design objectives, as the type of information extracted and leveraged can be used to control tradeoffs between various design objectives such as power, performance, and predictability, without requiring changes in the architecture.
Additionally, the static speculation based approach is or can be combined with dynamic techniques, in a solution that leverages both statically predictable, statically speculative, and dynamic information.
Rather than extracting only predictable information, that would require a conservative compilation approach, the new methods extract speculative static information. Such information, that is likely to be true for the typical execution instance, provides a larger scope for optimizations. The information is leveraged speculatively and supported with micro-architectural techniques to provide correctness of execution.
In addition to enabling extraction of more program information, the methods also increase the flow of information between compile-time and runtime layers/optimizations, by exposing the speculative static information to runtime layers.
The methods encode statically extracted information about predicted resource utilization into the Instruction Set Architecture (ISA), so that this information can be leveraged at runtime. This approach enables a more energy-efficient execution if used together with micro-architectural components.
The methods can be used to reduce power and energy consumption in both embedded and general-purpose systems. Furthermore, the methods are applicable to a wide-range of computer systems, both state-of-the-art and emerging, which build on ISA interfaces between hardware and compilation layers. The methods are independent from device level technology, and can be used to reduce energy consumption in both silicon based (e.g., CMOS) and emerging nano electronics based (e.g., carbon nano tubes, nano wires, quantum dots) systems.
Memory Systems
The presented embodiment relates to the cache and memory system mechanisms. Nevertheless, other embodiments, on the same principles of statically speculative execution and compilation, can be constructed.
Background on Memory Systems
The cache is a fast memory hierarchy layer, typically smaller in size than the physical address space. It is one of the cornerstones of computer systems, used to hide the latency of main memory accessing. This is especially important, due to the increasing gap between execution speeds and memory latency. While execution speeds are known to double every 18 months (Moore's law), memory latencies are improving at a much lower rate. With the increasing cache sizes, necessary to hide memory latencies, the energy impact of cache accesses becomes even more significant in future generation designs.
Every instruction is fetched from the memory hierarchy. Approximately 20-25% of the program instructions are data memory accesses that are fetched from a layer in the (data) memory hierarchy. Hence, memory accessing (instructions and data related) accounts for a large fraction of the total processor energy.
As caches are typically smaller in size than the main physical memory, not all memory accesses may be cached (i.e., found in the cache) at a given time. Fast lookup and detection, of whether a memory access is cached or not, in caches, is provided through associative search mechanisms and matching of tag information associated with data blocks.
Conventional caches consist of a tag memory and a data-array. The data array is where the actual information is stored. The tag memory is storing additional information related to blocks of data (also called cache blocks or cache lines) in the data-array. The tag information can be imagined as a label that identifies a block of data in the cache. Every memory access has this kind of label associated, as part of its address. The tag extracted from the address is compared with labels in the tag-memory, during a memory access, to identify and validate the location of a data block in the data-array.
If there is a tag that matches the current memory tag, then the access results in a cache-hit and can be satisfied from the cache data-array. If there is no tag in the tag-memory that matches the current tag then the access is a cache-miss (at this level at least) and the memory access needs to be resolved from the next layer in the memory hierarchy.
In associative caches multiple ways (i.e., alternative locations) are looked up in both tag memory and data-array.
Different systems have different organizations for memory hierarchies. Some systems have only one layer of cache before the main memory system, others have multiple layers, each increasingly larger (and slower typically) but still much faster than the main memory. Additionally, a memory system can have additional roles as described next.
The broader memory system may include additional mechanisms such as address translation, Translation Lookahead Buffer (TLB), virtualization, protection, and various layers and organizations of memory. Address translation is the mechanism of mapping logical addresses into physical addresses. Logical addresses are typically the addresses that appear on the address pins of the processor, while the physical addresses are those that are used on the actual memory chips.
Virtualization is the mechanism that enables a program compiled to run on machines with different memory system organizations. Protection is a mechanism that guarantees that memory accesses are protected against writing into unauthorized memory areas.
Approach in Memory Systems
The main components in the methods to reduce energy consumption in the memory system are: (1) compiler techniques to extract/leverage static information about memory accessing and data-flow, (2) tag-less and way-predictive compiler-enabled cache architecture based on speculative memory accessing, (3) methodology to interface and integrate the new methods into conventional memory hierarchies and combine static and dynamic optimizations, and (4) ISA extensions to expose memory accessing information.
The remaining structure of this description is as follows. Next, two embodiments are introduced. First, the architecture of the Tag-less compiler-enabled cache and related compiler technology are presented. Then, a memory system that combines statically managed memory accessing with conventional memory accessing, a tagged statically speculative cache, the ISA extension, and an embodiment of the compiler technology are described.
EMBODIMENTS
Two implementation examples are presented, for the purpose of illustrating possible applications of the statically speculative execution and compilation methods in memory systems.
The first embodiment is a Tag-less cache that can be integrated with other performance and energy reduction mechanisms. This scheme is especially attractive in embedded processors due to its low-cost, high-performance, low-power consumption as well as adaptivity to different application domains.
The second implementation is an embodiment in multi-level memory hierarchies. It shows how the method of statically speculative execution and compilation can be integrated in multi-level memory hierarchies. It provides the necessary compilation and architecture techniques for such integration. The methods are applicable, but not restricted to, both embedded and general-purpose domains.
1 st Embodiment: Tag-less Cache Architecture
This section describes an energy-efficient compiler-managed caching architecture, that has no tag memory and utilizes speculative static information. The architecture is shown in FIG. 1 .
Its main components are: Hotlines Register File 3 , Cache TLB (Translation Lookahead Buffer) 6 , Hotlines Check 5 , SRAM Memory 18 , Scratchpad Memory 19 , and Software (SW) Handler 15 . The arrows represent signals or flow in execution that are required for explanation: Virtual Line 1 , Hotline Index 2 , Result of Cache TLB lookup 10 , Cache TLB Miss signal 12 , Hotline Register Hit/Miss result 5 , Hotline Miss 7 , Hotline Hit 8 , Address from cache TLB 9 , Cache TLB Hit 11 , Software Handler Cache Hit 13 , Address 16 , Enable to Scratchpad 17 , Software Handler Detected Cache Miss 14 , Data output from SRAM 20 , and Data output from scratchpad 21 .
In this following explanation a design example where scalar accesses are mapped to the scratchpad 17 and the non-scalars to memory 18 is assumed. This however is not necessary; another application of this architecture is to map all the memory accesses to either the hotlines or the conventional paths. Other memory accessing techniques could also be combined with the ones described here.
The scratchpad access mechanism consumes very low power due to its small size (a 1 Kbytes memory is used, but this can be a banked memory where the actual use is application specific controlled by the compiler). All accesses directed to the scratchpad 17 are then output on 15 , being enabled by signal 12 decoded from the memory instruction.
The memory instructions that are using the hotline path carry a hotline index 2 that has been determined at compile time. This identifies the hotline register from register file 3 , predicted by the compiler to contain the address translation for the current memory access. Using this index 2 , the corresponding hotline register is read from the hotline register file 3 . A hotline register file is similar to a general purpose register file, but contains register promoted cache pointers instead of operands. In addition to the statically indexed mode, an associative lookup can also be implemented to speed up access during replacement.
The hotline register contains the virtual cache line address to SRAM line address 16 mapping. If the memory reference has the same virtual line address as that contained in the hotline register during the Hotlines Check 5 (i.e., correctly predicted speculative static information), there is a Hotline hit 8 . Upon a correct static prediction, the SRAM can be accessed through the SRAM address 16 ; this address is from the hotline register that is combined with the offset part of the actual address, and the memory access is satisfied. The offset is the part of the address used to identify the word within a cache line. If there is a static misprediction (i.e., the memory access has been encoded at compile-time with an index that points at runtime to a hotline register that does not contain the right translation information) that causes a Hotline Miss 4 , the cache TLB 6 is checked for the translation information.
If the cache TLB 6 hits or signal 11 is set, the hotline register file 3 is updated with the new translation, and the memory access is satisfied from the SRAM memory 18 . Data is output on 20 . A Cache TLB miss 12 invokes a compiler generated software handler 15 to perform the address translation. This handler checks the tag-directory (which itself can be stored in a non-mapped portion of the memory) to check if it is a cache miss 14 .
On a miss 14 , a line is selected for replacement and the required line is brought into its place—pretty much what happens in a hardware cache, but handled by software here. The cache TLB 6 and the hotline register 3 are updated with the new translation, and the memory access is satisfied by accessing the SRAM memory 18 and outputting the data on 20 .
Because the software handler 15 is accessed so seldom, its overhead has minimal effect on the overall performance. This cache can, in fact, even surpass a regular hardware cache in terms of performance. For one, the interference between memory accesses mapped to different paths has been eliminated resulting in better hit-rate, and better cache utilization.
Secondly, a high associativity is basically emulated, without the disadvantage of the added access latency in regular associative caches, where higher associativity increases cache access times. Since the SRAM access mechanism is much less complicated than a regular tagged hardware cache, there is a possibility of reduction in cycle time.
Additionally, both the hotline path (i.e., 2 , 3 , 5 , 7 ) and the scratchpad path (i.e., 17 , 19 , 21 ) will have a smaller hit latency than in a conventional cache. This latency (in conventional caches) would be even larger if runtime information is used to predict way accesses. Furthermore, an optimal line size can be chosen on a per application basis, as the line here is not fixed but it is based on a compiler determined (logical) mapping.
Access Mechanisms
This cache architecture combines four cache control techniques: (1) fully static through 19 , (2) statically speculative through 2 , 3 , (3) hardware supported dynamic 6 , and (4) software supported dynamic through the software handler 15 . FIG. 1 shows this partitioning with the dotted line. To the left the architectural mechanisms implement dynamic control, to the right, static control.
The fully static cache management is based on disambiguation between accesses with small memory footprints such as the scalars and other memory accesses. Furthermore, frequently accessed memory references that have a small footprint can be mapped into the scratchpad area. This architecture can also be used without the scratchpad memory, by having all memory accesses mapped either through the statically speculative techniques or some other path.
The second technique in this architecture is based on a compile time speculative approach to eliminate tag-lookup and multiple cache way access. In addition, some of the cache logic found in associative caches can also be eliminated. The idea is that if a large percentage of cache accesses can be predicted statically, it is possible to eliminate the tag-array and the cache logic found in associative caches, and thus reduce power consumption.
The accesses that are directly mapped to the scratchpad memory require no additional runtime overhead. The statically speculative accesses however, if managed explicitly in the compiler, use virtual to SRAM address mappings or translations at runtime. This mapping is basically a translation of virtual cache line block addresses into SRAM cache lines, based on the line sizes assumed in the compiler.
Note that the partitioning of the SRAM into lines is only logical, the SRAM is mainly accessed at the word level, except for during fills associated with cache misses. Inserting a sequence of compiler-generated instructions, at the expense of added software overhead, can do this translation. For many applications there is a lot of reuse of these address mappings. The compiler can speculatively register-promote the most recent translations into a small new register area—the hotline register file. With special memory instructions, or other type of encoding of this information, the runtime overhead of speculation checking can be completely eliminated. Nevertheless, in simple designs a software based check that can be implemented in four regular instructions is also possible.
To avoid paying the penalty during a statically miss-predicted access, a small fully associative Cache TLB 6 is used to cache address mappings for memory accesses that are miss-predicted. A 16-entry Cache TLB 6 is enough to catch most of the address translations that are not predicted correctly statically. Different application domains may work fine with a smaller or require a slightly larger size for optimum energy savings.
The fourth technique used in this architecture, is basically a fully reconfigurable software cache 15 . This technique is a backup solution, and it can implement a highly associative mapping. This implementation is for example based on a four-way associative cache. The mapping table between virtual cache lines 1 and physical SRAM lines 16 can be implemented similar to an inverted page table or other schemes. Experimental results show that the combined static and cache TLB techniques often capture/predict correctly more than 99% of the memory accesses.
From a power perspective, this cache has substantial gains compared to a conventional hardware cache for two reasons. First, there are no tag-lookups on scalar accesses and correctly predicted non-scalar accesses. Second, the SRAM is used as a simple addressable memory—the complicated access mechanisms of a regular cache consume more power and increase the memory access latency (e.g., the hit-latency).
2 nd Embodiment: Statically Speculative Memory Accessing in Conventional Memory Systems
In general there are two main steps involved in a memory access: (1) converting the program address to a cache address, and (2) accessing the data from this address, if present in cache (accessing the slower memory such as DRAM if not present). Depending on the implementation, there can be considerable power/performance redundancy associated with both of these steps. This redundancy problem is described in the next subsection, following with implementation embodiments to tackle this problem. The invention is not limited to these embodiments.
FIG. 3 shows the memory access process. The translation function translates the larger program address 100 into a cache block address shown as part of 110 (the lower order block offset bits in 100 do not undergo any translation).
Depending on the caching scheme, this translation can be very expensive, both energy-wise (for example, on a virtual memory system with a 4-way cache, the virtual address 100 will be converted to physical address by the TLB 105 , and all the 4 tag and data arrays 112 , 113 , 114 , 115 would be looked up in parallel), and performance-wise (if the cache is software managed, doing the translation in software will consume valuable CPU cycles). The translation information 109 in case of a TLB hit 108 is added with the offset to form address 110 that is used to access the cache.
Where is the redundancy? Looking at a cache block level, two program addresses with the same virtual block address map to the same cache block. Therefore, the second translation is redundant. In general, if there is a group of memory accesses mapping to the same cache block, repeating the translation process on each access can be wasteful. Additionally, if the cache way for the access is known, looking up all the four ways (e.g., way 3 112 , way 2 113 , way 1 114 ) is not necessary. Furthermore, the tag lookup 111 is wasteful if the tag has been checked for an earlier access in the same cache block.
The usual implementation maps all the accesses to the same cache. This scheme may also be extravagant: many applications often exhibit the behavior where a small set of references are accessed very often—these can be accommodated in a small partition of the cache which consumes much less power. Therefore, partitioning the cache and devising a wiser translation function, which maps different accesses to different cache partitions depending on their access pattern, can amount to sizable energy savings.
The aforementioned redundancies are tackled using a cooperative compiler-architecture approach. Specifically, compiler analysis techniques that identify accesses likely to map to the same cache line are developed. These accesses can avoid repeated translation to save energy. The compiler in the proposed method speculatively register promotes the translations for such groups of accesses.
These registers that contain address translation information are provided as a form of architectural support. At runtime, the architecture is responsible for verifying static speculations: if correctly predicted by the compiler, the expensive translation is eliminated. On mispredictions, the architecture can update the registers with new information. Further, the level of speculation in the compiler can be varied to better match application behavior. Henceforth, the solution proposed is referred to as the microarchitecture in 2 nd embodiment.
Conventional general-purpose microprocessors use a one-size-fits-all access mechanism for all accesses. The subject architecture in the 2 nd embodiment derives its energy savings by providing different energy-efficient access paths that are compiler-matched to different types of accesses. Next an overview of the subject architecture in the 2 nd embodiment is presented and followed with detailed discussions on the features of this architecture.
Two different organizations of the architecture in the 2 nd embodiment are shown. In both organizations a virtually-indexed and virtually-tagged first level cache is used and address translation is moved to lower levels in the memory hierarchy. Other type of cache organizations are also possible. As second level or L2 cache, both a physically-indexed and a virtually-indexed cache are shown. Some of the design challenges in virtual-virtual organizations (e.g., the synonym problem, integration in bus based multiprocessor systems, and context-switching with large virtual L2 caches) could be handled easier in virtual-physical designs. In both organizations, translation buffers are added. A translation buffer is a cache for page level address translations and is used to avoid the more expensive page table lookup in virtual memory systems.
In the virtual-virtual (v-v) organization, a translation buffer (MTLB) is added after the L2 cache and is accessed for every L2 cache miss. This serves better the energy optimization objectives than a TLB-less design, where address translation is implemented in software. Nevertheless, if increased flexibility is desired, in the way paging is implemented in the operating system, the TLB-less design is a reasonable option (experimental results prove this point). In the virtual-physical organization (v-r), a translation buffer (STLB) is added after the L1 cache and is accessed for every L1 cache miss or every L2 cache access.
An overview of the different cache organizations with address translation moved towards lower levels in the cache hierarchy is shown in FIG. 2 . As address translation consumes a significant fraction of the energy consumed in the memory system, both the v-v and v-r designs will save energy compared to a physical-physical (r-r) cache hierarchy, where virtual-to-physical address translation is done for every memory access.
A context-switch between threads belonging to different tasks may require change in virtual address mappings. To avoid flushing the TLBs address-space identifiers to TLB entries are added. Note that not having the address-space identifiers not only would require flushing all the TLB entries, but would also imply that the newly scheduled thread, once it starts executing, will experience a number of TLB misses until its working set is mapped.
FIG. 4 presents an overview of the subject architecture in the 2 nd embodiment memory system, with integrated static 200 and dynamic 201 access paths. The subject architecture in the 2nd embodiment extends associative cache lookup mechanism 215 , 216 , 217 , 218 , with simpler, direct addressing modes 213 , in a virtually tagged and indexed cache organization. This direct addressing mechanism 213 eliminates the associative tag-checks (i.e., no tag-lookup as shown in 215 , 216 , 217 , 218 is required) and data-array accesses (i.e., only one of the data-arrays from 215 , 216 , 217 , 218 is accessed). The compiler-managed speculative direct addressing mechanism uses the hotline registers 208 . Static mispredictions are directed to the CAM based Tag-Cache 210 , a structure storing cache line addresses for the most recently accessed cache lines. Tag-Cache hits also directly address the cache, and the conventional associative lookup mechanism is used only on Tag-Cache misses. Integration of protection-checks along all cache access paths ( 208 , 210 and conventional) enables moving address translation to lower levels in the memory hierarchy, as described earlier, or TLB-less operation. In case of TLB-less designs, an L2 cache miss requires virtual-to-physical address translation for accessing the main memory; a software virtual memory exception handler can do the needful.
Support for Moving the TLB to Lower Levels in the Memory Hierarchy or TLB-less Operation
The subject architecture in the 2nd embodiment employs virtually addressed caches, and integrates support for protection checks, otherwise performed by the TLB, along all access mechanisms. That is, the subject architecture in the 2nd embodiment has embedded protection checks in the Hotline registers 208 , the Tag-Cache 210 , and cache tags (shown as part of 215 , 216 , 217 , 218 ). The subject architecture in the 2nd embodiment therefore could completely dispense with the TLB.
L2 cache misses in the v-v organization require address translation for the main memory access. The subject architecture in the 2nd embodiment uses translation buffer to speed up this address translation, but a software VM exception handler for doing the translation on L2 cache misses and fetching the data from the main memory can also be used.
The statically speculative, compiler managed memory accessing can also be integrated in other type of memory hierarchies.
Hotline Registers
The conventional associative lookup approach 4 parallel tag-checks and data-array accesses (in a 4-way cache). Depending on the matching tag, one of the 4 cache lines is selected and the rest discarded. Now for sequences of accesses mapping to the same cache line, the conventional mechanism is highly redundant: the same cache line and tag match on each access. The subject architecture in the 2nd embodiment reduces this redundancy by identifying at compile-time, accesses likely to lie in the same cache line, and mapping them speculatively through one of the hotline registers 208 .
The condition that the hotline path evaluates can be done very efficiently without carry propagation. The hotline cache access can also be started in parallel with the check, with the consequence that in case of incorrect prediction some additional power is consumed in the data-array decoder. As a result, the primary source of latency for hotline based accesses, is due to the data array access and the delay through the sense amps. Note that conventional associative cache designs use an additional multiplexer stage to select between ways in a multi-way access (i.e., the correct block from the ways 215 , 216 , 217 , 218 ). Furthermore, as shown in previous cache designs, the critical path is typically the tag-path; the tag latency can be as much as 30% larger than the latency of the data-array path in the conventional design.
Reduced feature sizes in next generation architectures will further accentuate the latency increase of the tag path. Because of this, in conventional cache designs, the way-selection logic is moved towards the tag to rebalance the delay differences between the tag and data-array paths. In the subject architecture in the 2nd embodiment the latency of the data-array could be the main target for optimizations, as the tag path is not on the critical path for most of the memory accesses, by adequate bitline and wordline partitioning. Additionally, as physical cache designs would require the TLB access completed to perform the tag comparison (the tag access could be however done in parallel), this may also add to the tag path latency. As such, the subject architecture in the 2nd embodiment based microprocessor could either have a faster clock or at least a faster cache access for statically predicted cache accesses.
The different hotline compiler techniques are described in the next section. A simple run-time comparison 211 reveals if the static prediction is correct. The cache is directly accessed on correct predictions 213 , and the hotline register 208 updated with the new information on mispredictions. A fully associative lookup on the hotline registers to support invalidations is included.
As shown in FIG. 6 , a hotline register 208 has 3 components: (1) protection bits (ASID), which are used to enforce address space protection, (2) TagIndex—two accesses are to the same cache line if their Tag and Index components are the same. The TagIndex component is compared with Tag and Index of the actual access to check if the hotline register can indeed be used to directly address the cache, (3) cache-way information—this information enables direct access to one of the ways in the set-associative cache.
Tag-Cache
Another energy-efficient cache access path in the subject architecture in the 2nd embodiment is the Tag-Cache 210 . It is used both for static mispredictions (hotline misses 212 ) and accesses not mapped through the hotline registers, i.e., dynamic accesses 201 . Hence it serves the dual-role of complementing the compiler-mapped static accesses by storing cache-line addresses recently replaced from the hotline registers, and also saving cache energy for dynamic accesses; the cache is directly accessed on Tag-Cache hits 211 , 213 .
A miss in the Tag-Cache 210 implies that associative lookup mechanism is used with an additional cycle performance overhead. The Tag-Cache is also updated with the new information on misses, in for example LRU fashion. As seen in FIG. 4 , each Tag-Cache 210 entry is exactly the same as a hotline register 208 , and performs the same functions, but dynamically.
Associative Lookup
The subject architecture in the 2nd embodiment uses an associative cache lookup that is different from the conventional lookup in that the protection information (ASID) is also tagged to each cache line. Even the virtually addressed L2 cache is tagged with protection information in the v-v design to enable TLB-less L2 access. This increases the area occupied by the tag-arrays, and also its power consumption. Compared to the overall cache area and energy consumption, this increase is however negligible.
Instruction Set Architecture (ISA) Support
To access the memory through the hotline registers, memory operations 200 that encode the hotline register index should be provided. This index is filled in during compile time based on the techniques described in the compiler section. The implementation should perform a simple check 211 between the content of the hotline register identified and the actual virtual block address, as shown in FIG. 4 . Special instructions, rather than modifications to existing can also be provided for example. Alternatively, techniques requiring no ISA modifications could also be used, as shown in the section. The invention is not limited to type of encodings described herein.
Approach Not Requiring ISA Support
Static information about the hotline registers 208 accessed could be provided by generating code that writes this into predetermined memory locations, e.g., into a stream-buffer. This buffer can be used to add the index at runtime to memory accesses in the critical path. For example, memory accesses that are identified in critical loops could use the index information from this buffer during the Instruction Decode stage to access the hotline registers. The invention is not limited to type of encodings described herein.
An Embodiment of the Compilation Process
FIG. 5 shows a high-level picture of the stages involved in an embodiment for compilation. The implementation is using the SUIF format. The invention is not limited to this format or to the compilation embodiment presented.
The program sources are first converted to the intermediate format 301 and high-level optimizations are performed 306 . Following that is the Alias Analysis stage, or equivalent, and the Hotlines passes 302 . Alias information enables the Hotline Analysis to more economically assign hotlines to references (i.e., map cache pointers to registers). Without alias analysis, the compiler would liberally assign each memory reference a new hotline number. This will have a downgrading effect only if the number of references within inner loop bodies is more than the number of hotlines, resulting in the same hotlines being assigned to possibly spatially far apart references. This would cause interference and result in lower prediction rates. For many applications, the media benchmarks tested in particular though, this is not so and the alias analysis stage could be omitted with minimal effect on the prediction rates. Code is generated based on the information extracted in 303 . Optimizations are performed on the high-level representation 305 (e.g., based on expression trees) and low-level representation 306 (e.g., flat instruction sequences). Finally the generated code is run through an assembler 304 and results in a binary.
The Section “Hotlines With Speculative Alias analysis shows a speculative data-flow analysis technique that further improves on the precision the range of location sets is determined and extends its scope to large and complex applications. Additional passes include code generation 303 that takes into consideration the results of the analysis above, and then assembling the code 305 into a binary format.
Caches represent a large fraction of processor power consumption. Given accesses, a speculative analysis to predict which cache line is being accessed is used. Although it is impossible do this with perfect accuracy, the methods described herein provide an approach with good overall accuracy. Moreover, as pointed out above, it is not necessary for predictions to be perfect, rather, they should be right sufficiently often that one can make beneficial use of them.
Almost all programs exhibit the behavior where certain cache lines are “hot”, i.e., they are being used much more frequently than others. If the compiler can register promote the cache pointers for these hot cache lines, the lookup for the many accesses mapping to these cache lines can be avoided, i.e., the compiler can identify at cache lines that are heavily used, and for all accesses going to these, map them through an energy-efficient memory access mechanism.
Basic Hotlines Analysis
This process assigns each variable name a different hotline register starting with the first register. When all the registers have been used up, it wraps around back to the first register. The following example illustrates this process:
for(i = 0; i < 100; i++) {
a[i]{1} = a[i+1]{1};
// numbers in curly braces
b[i]{2} = 0;
// are the hotline registers
*(p++){3} = 1;
// assigned by the process
}
The variables have been assigned three hotline registers. For example, the hotlines process predicts that all the a[ ] accesses for example, will map to the same cache line and register promotes the cache pointer in register 1 .
In particular, if the a[ ] is a word-sized array and the cache line is 8 words wide, a[ 0 ] and a[ 7 ] could map to one cache line, a[ 8 ] through a[ 15 ] to another, and so on.
Therefore, for this case, the process has seven correct predictions for every misprediction.
In general, this simple process works well with programs with high spatial locality, like multimedia programs. Below, enhancements to the basic approach are described.
Hotlines Combined with Alias Analysis
An accurate flow and context sensitive alias analysis can reveal the location set that any pointer can be pointing to at any given context in the program. Consider the following example:
int a[100], b[100];
. . .
. . .
if ( . . . ) p = a; else p = b;
for(i = 0; i < 100; i++) {
a[i] = 0;
*(p++) = 1; // location_set(p) = {a, b}
}
The if-statement assigns either the array a or b to the pointer p. This means that inside the loop, p could be accessing either array a or b.
A context- and flow-sensitive compiler would extract this information: the location sets of pointers at various points in the program. As mentioned earlier, this can help in a more efficient hotline process: perform alias analysis and then during the hotlines phase, utilize alias information to better handle pointer-based accesses.
Perfect alias analysis is not typically possible for large and complex applications, especially those using precompiled libraries. Instead, a speculative alias analysis is developed as part of the solution proposed. This is described in Section “Hotlines with Speculative Alias Analysis”.
Enhancement with Type, Distance and Dependence Analysis
This process hotlines all accesses like the basic hotline process, but is more refined. If an array a[ ] has been mapped through register r 1 , it won't necessarily be mapped through register 1 again. Instead the process will try to calculate the spatial distance of this access to the previous one. Only if they are sufficiently close will they be mapped through the same register.
The following example illustrates how the process works:
for(i = 0; i <100; i++) {
a[i]{1} = a[i+1]{1} + a[i+100]{2} + a[i+103]{2};
b[i]{3} = 0;
// number in curly braces is the hotline
p{4} = p→next{4}
// register assigned by the process
}
Suppose the array element-size is 4 bytes, the cache line is 64 bytes, and that two accesses are mapped to the same register if they are within 32 bytes from each other.
The hotlines process first assigns a[i] hotline register r 1 . When it comes to a[i+1], it checks the distance from currently mapped accesses, and finds the closest one to be a[i] which is 4 bytes apart. Since this is within the threshold, a[i+1] is also mapped through r 1 . For a[i+100], the closest access a[i+1] is 396 bytes apart, and hence a[i+100] is mapped through a different hotline. The array accesses b[ ] is assigned register r 3 and so on.
In evaluating the distance between two accesses, the hotlines process uses control-flow, loop structure, dependence and type information: field offsets in structures, array element sizes, etc.
Support for Various Levels of Static Speculation
This process can be made to vary in its level of aggressiveness. A very aggressive version would carry out actions based on predictions which do not necessarily have a high degree of confidence. A conservative version may not do so, for instance, it would not hotline non-affine array accesses of the form a[b[i]] which are generally hard to predict. Different versions of this process with different levels of aggressiveness can be constructed. The invention is not limited to one particular implementation.
Hotlines with Speculative Alias Analysis
This analysis is part of the embodiment presented for the compilation process. The objective of this analysis is to extract precise information about memory access patterns in pointer based accesses. The proposed technique is speculative in the sense that the possible values for each pointer access are determined and included based on their likelihood of occurrence at runtime. Unlikely values are ignored and highly likely values are added, even when the full proof cannot be derived at compile-time.
One of the primary motivations for developing the speculative alias analysis (SAA) process is because the more precise implementations of non-speculative alias analysis have limitations when used for large programs or when special constructs such as pointer based calls, recursion, or library calls are found in the program. The less precise alias analysis techniques, that are typically used in optimizing compilers, have lower complexities but they are much less useful in the context of extracting precise information about memory access patterns. The experience with several state-of-the-art research alias analysis packages shows that they don't work well for these programs. For example, none of the SPEC2000 benchmarks could be analyzed with them. SAA based analysis can not only be applied without restrictions and has lower complexity, but also provides more precise information about memory accesses.
The information given by this analysis can be used in the hotlines processes, e.g., to determine which cache pointer (or hotline register) to assign to a given pointer based memory access. Additionally, the same information can be used in disambiguating pointer based loop-carried dependencies, to estimate loop level parallelism in addition to ILP.
There are two ways to give pointer information: (1) through program-point information, and (2) through global information. FIG. 6 shows a simple C program and illustrates the difference between these representations.
Program point information for example would show that at the end of the program segment in FIG. 6 , pointer p points to {y,z}, a more precise information, compared with the global information case where p points to {x,y,z}. Although global information can be extracted with much more efficient analysis process, it gives less precise results.
In general, alias analysis is done at either the intra-procedural level or at the inter-procedural level. The latter considers analysis across call statements, attempts to handle recursive, and pointer-based calls.
For intra-procedural analysis, a variety of processes with different degrees of precision and efficiency have been developed. A more precise analysis results in narrower sets (i.e., fewer possible values for a pointer to take). Flow-sensitive analysis takes control flow into account usually giving program-point results. Flow-insensitive analysis views a program as a set of statements that can be executed in any order and gives per program or global results.
Flow-insensitive processes can be built on top of a type-based analysis or constrained-based analysis. Because of the higher precision of flow-sensitive approaches are of more interest in these techniques. Flow-sensitive approaches are typically based on traditional dataflow analysis, where pointer information is represented with points-to graphs (PTG). The speculative approach defined in the SAA process could be applied to any type of alias analysis.
Nodes in a PTG correspond to program variables and edges represent points-to relations. A points-to relation connects two variables and means that a pointer variable can take the value of another variable during execution. Intuitively, a smaller number of points-to relations means better precision.
The main steps in a non-speculative flow-sensitive analysis process are as follows: (1) build a control-flow graph (CFG) of the computation, (2) analyze each basic block in the CFG gradually building a PTG, (3) at the beginning of each basic block merge information from previous basic blocks, (4) repeat steps 2-3 until the PTG graph does not change. See for example in FIG. 7 , the CFG and the PTG for a simple C application.
This analysis builds a PTG for the program in a conservative way, i.e., it guarantees that for each variable all the possible points-to relations are captured. The SAA approach removes some of these points-to relations when it predicts them as seldom-occurring. A point-to relation is defined to be a weak points-to relation if the edge is less likely to be leveraged during execution compared to other points-to relations from the same pointer variable.
FIG. 8 exemplifies the flow-sensitive embodiment of the SAA process in loops, for the simple case when point-to relations are mapped to either weak or strong ones. One of the process's rules is that the incoming location sets are the weak point-to relations, and are removed if there is any strong point-to relation for the same access within the loop body. A generalization of this process, for nested loops, is to consider loop nests organized in pairs, with inner loop updates being strong and incoming edges weak, and so on.
FIG. 8 shows that a great deal of precision has been obtained by removing several edges in the PTG. For example, both pointer p and q has been determined to point to only variable c after only three iterations in the process.
The complexity of the SAA process is reduced compared to traditional alias analysis process. One possible implementation is by stopping the dataflow analysis after a certain number of iterations. Other implementations are also possible. The main complexity in non-speculative alias analysis is coming from dealing with loops, recursive calls, multithreaded analysis, and library calls in an inter-procedural analysis. The analysis in the SAA process applies an approximate approach and stops the dataflow analysis before full convergence is reached in such cases. Library calls that may modify pointer values and for which source codes are not available can also be speculatively estimated or ignored.
An example of implementation of the SAA process is as follows: (1) build a control-flow graph (CFG) of the computation, (2) analyze each basic block in the CFG gradually building a points-to graph (PTG), (3) at the beginning of each basic block merge information from previous basic blocks, (4) annotate weak and strong point-to relations focusing on loops by looking at incoming point-to relations and point-to relations in loop bodies, (5) speculatively estimate recursive calls and library calls, (6) repeat steps 2-5 until the PTG graph does not change or until a predetermined number of steps in the analysis have been reached.
The methods described in this embodiment have been implemented and carefully evaluated.
A small sampling of data giving a preview of the accuracy of static speculation obtained with this implementation is presented in FIG. 9 . As shown, both memory accessing and instructions executed per cycle could be predicted statically with good accuracy. Better prediction translates into the possibility of saving more energy.
FIG. 10 shows the breakdown of processor-wide energy savings obtained due to significantly reduced energy consumed in the memory system. It shows that up to 75% of the energy consumed in memory accessing can be saved. This translates into up to 21% total energy reduction in an Alpha 21264 type of processor. A description of some the benchmarks evaluated, but not limited to, is presented in FIG. 11 .
The invention is not limited to, but can also be used to improve performance in processors. Reduction of access latencies in caches, for example, in the embodiments shown, can improve memory accessing performance. Alternatively, it can enable faster clock rates that would reduce execution time, or would enable using larger caches that would improve memory performance. Other performance benefits can result from, but not limited to, more efficient execution.
Other embodiments not described herein are also within the scope of the following claims. | A system, for use with a compiler architecture framework, includes performing a statically speculative compilation process to extract and use speculative static information, encoding the speculative static information in an instruction set architecture of a processor, and executing a compiled computer program using the speculative static information, wherein executing supports static speculation driven mechanisms and controls. | 8 |
FIELD OF THE INVENTION
The present invention is related to communication techniques and, more particularly, to techniques for detecting a transport format in a communication system.
BACKGROUND OF THE INVENTION
A communication network transfers information, such as voice, video and telemetry, among the User Equipment (UE) of subscribers. Information, such as broadband Internet data, broadcast services, and network control data, can be transferred between the network itself and the subscriber UEs. A number of existing networks, such as Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (3rd Generation cellular/radio technology) (CDMA2000), and Worldwide Interoperability for Microwave Access, Inc. (WiMAX), according to the IEEE 802.16 wireless broadband standard, support parallel operation of a plurality of such information services. For such support, and for optimization of the network capacity, these networks must be able to transfer information at rapidly changing data rates. The networks must also be able to combine the different services into a single physical data stream, used to transfer the combined information over the physical channel.
The Transport Layer typically combines data of different rates. The combination of information services and data rates changes rapidly. Thus, the transmitter must notify the receiver of the change at high rates. Most systems attach an additional header to transmitted data, describing the service combination format and data rates of the currently transferred data. This addition, naturally, increases the overhead.
In WCDMA (UMTS), for example, each service is related to a transport channel (TrCH). The service combination and data rate selection format used to combine the TrCHs into a physical data stream coded composite transport channel (CCTrCH), is referred to as a transport format combination (TFC). A transport format combination indicator (TFCI) is attached to each frame of data to indicate which the TFC that was selected. The receiver uses the TFCI to select the format for the decoding and separation of data into the different services. This process is referred to as TFCI signaling.
A number of techniques have been proposed or suggested for conserving the bandwidth required for TFCI signaling. For example, a Blind Transport Format Detection (BTFD) method was introduced in “Multiplexing and Channel Coding (FDD),” 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, 3GPP TS 25.212 V4.5.0 (2002-06). The disclosed Blind Transport Format Detection method detects the TFC with a blind algorithm.
A Blind Transport Format Detection method must perform three types of TrCHs detection, namely, single, explicit, and guided transport channel format detection. A single transport format detected TrCH has a transport set not containing more than one transport format with more than zero transport blocks and that does not use guided detection. The transport format with more than zero transport blocks must have CRC with non-zero length. Energy detection and a cyclic redundancy check (CRC) are used to blindly detect the transport format transmitted by the single transport format detected TrCH when this TrCH is the only TrCH of the CCTrCH.
Explicit and guided transport format detected TrCHs are non-signaled TrCHs that have more than one transport format and do not use single detection. An explicitly detected TrCH must have at least one block transmitted every Transmission Time Interval (TTI). Each block of an explicitly detected TrCH is appended with a non-zero CRC. Guided detection is used on a TrCH with zero length CRC that is associated with an explicitly detected TrCH. By detecting the transport format of an explicitly detected TrCH, the transport format of the associated guided detected TrCH is also decided.
In order to perform explicit and single detections, CRC is checked for all possible transport format combinations. A valid TFC (transport format combination) is selected if the CRC was valid for all TrCHs in the CCTrCH using this combination. This technique, however, can introduce a misdetection of the TFC, since statistically, CRC checks of all TrCHs may be erroneously valid for a TFC that was not transmitted. A need therefore exists for a Blind Transport Format Detection method that avoids the misdetection problem.
SUMMARY OF THE INVENTION
Generally, methods and apparatus are provided for blind transport format detection using Discontinuous Transmission detection. According to one aspect of the invention, the transport format that was used to transmit information is determined by identifying a transition between a Discontinuous Transmission segment and a data segment included in the transmitted information; and determining the transport format based on a location of the transition of the Discontinuous Transmission segment.
For example, a size of the Discontinuous Transmission segment can be identified and the transport format can be determined based on the size. In a further variation, an energy associated with the data segment relative to energy of a reference segment is determined, and the transport format can be determined based on the energy associated with the data segment.
A cyclic redundancy check can optionally be performed for a plurality of possible transport formats, and then the step of identifying a transition can be limited to those transport formats having a valid cyclic redundancy check. For example, a start of DTX address can be determined for each of the transport formats having a valid cyclic redundancy check.
A more complete understanding of the present invention, as well as further features and advantages of the present invention, will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary memory segmentation of a first deinterleaver;
FIG. 2 illustrates pseudo code for an exemplary blind transport format detection process incorporating features of the present invention; and
FIG. 3 illustrates the execution of the exemplary blind transport format detection process of FIG. 2 for a memory segment where there are three transport formats with valid CRCs.
DETAILED DESCRIPTION
The present invention provides a Blind Transport Format Detection method and apparatus that avoid the misdetection of the TFC by using a Discontinuous Transmission (DTX) detection technique. As used herein, the term “Discontinuous Transmission” or “DTX” shall apply to any temporary situation where the transmitting side transmits at a reduced power level, relative to the transmission of data or payload, for a specific user. Typically, the transmitting side does not transmit any power for a specific user when transmitting the DTX. While there may be different reasons in different systems or under different scenarios to use DTX (e.g., saving power, introducing less interference to other users and reducing the number of transmitted bits), the DTX allows the present invention to determine the transport format, as would be apparent to a person of ordinary skill in the art.
Blind Transport Format Detection Using Path-Metric Values at Surviving Paths
In order to prevent the misdetection of a TFC, an additional operation is required to test the validity of the detection of each of the TrCHs in the CCTrCH. The above-cited 3GPP TS 25.212 V4.5.0 specification suggests using the path-metric values at the surviving paths of the Viterbi decoding of each of the TrCHs. The path-metric value of the zero state and the minimum and maximum values of the remaining states are used to calculate the scatter of the Viterbi decoding in the following manner:
S ( ⅈ ) = - 10 log ( a 0 ( ⅈ ) - a min ( ⅈ ) a max ( ⅈ ) - a min ( ⅈ ) ) [ dB ]
where i is the TFI of detected TrCH; S(i) is the scatter of Viterbi decoding; a 0 (i) is the zero path-metric value; a min (i) is the minimum of remaining path-metric values; and a max (i) is the maximum of remaining path-metric values.
The detection of a transport format is considered valid if the value of S(i) is greater than a predefined threshold, D. Generally, the transport format with the largest scatter is selected from all the TrCHs that pass the CRC check, and are considered valid according to the above method.
This method is applicable as long as access to the path-metric of the Viterbi decoder is available. This, however, is not necessarily guaranteed when integrating a 3G chip, composed of various cores and coprocessors. Also, addition of path-metric access in a Viterbi decoder design, naturally, requires an increase in silicon volume. In addition, this method does not supply a complete solution to the single transport format detected TrCH, in which a zero block transport format is present and does not go through the Viterbi decoding stage.
Blind Transport Format Detection Using DTX Detection
The present invention provides a Blind Transport Format Detection method and apparatus that avoid the misdetection of the TFC by using a DTX detection technique. The present invention provides a method for preventing the misdetection of a TFC by attaining energy related information from an accessible memory component, allowing easy processing of the stored data. In one exemplary implementation, misdetection of a TFC is achieved by attaining energy related information from the first deinterleaver. Since the first deinterleaver is a memory component, it can be accessed, allowing the stored data to be processed. As discussed further below, the energy information allows the transition points from data to DTX to be identified, which allows a one-to-one mapping to the transport format.
FIG. 1 illustrates an exemplary memory segmentation of a first deinterleaver 100 . The exemplary memory segmentation of the first deinterleaver 100 may be embodied, for example, as described in the above-cited 3GPP TS 25.212 V4.5.0 specification. As shown in FIG. 1 , the first deinterleaver stores a complete TTI of data for each TrCH in a designated, predefined memory segment, such as segment 110 - 0 . When the maximum size transport format is received for a TrCH, its whole designated memory segment 110 in the first deinterleaver 100 is filled (with no DTX). When, however, any other transport format is received, the memory segment is filled with data and DTX padding. The DTX padding is stored at the end of each received frame of the TrCH in the memory segment 110 . There is always non-DTX data at the beginning of a frame, as the smallest transport format must have non-zero CRC.
The present invention recognizes that the size of the DTX segment has a one-to-one mapping to the Transport Format (a situation that is defined in the 3GPP specification as a Fixed Position mode). When using compressed mode by puncturing, such as shown in FIG. 1 , p-bits replace the first bits of the frame of the TrCH that is to be compressed. The position of amount of the p-bits in fixed position is similar for all possible transport formats of the TrCH.
FIG. 2 illustrates pseudo code for an exemplary blind transport format detection process 200 incorporating features of the present invention. Generally, the blind transport format detection process 200 is implemented when more than one possible transport format combination (TFC) has a valid CRC using the conventional method described above. Thus, the blind transport format detection process 200 shown in FIG. 2 is used to distinguish between two or more transport formats, detected with a valid CRC for a single TrCH.
For each frame in a TTI of the processed TrCH, the blind transport format detection process 200 initially attains the base address, A B , of the frame in the designated TrCH memory segment 110 during step 210 . Thereafter, the blind transport format detection process 200 sorts all N transport formats with valid CRCs in descending order during step 220 , such that the maximum size TF index equals 0 and the minimum size TF index equals N−1.
For each transport format index, i, with a valid CRC, the blind transport format detection process 200 then attains the start of the DTX address, A DTX (i), during step 230 . If p-bits present (for puncturing), update the base address during step 240 , as follows:
A B =A B +number of p-bits.
The memory is divided into sub-segments during step 250 , as follows:
Seg(0)= A DTX (1) . . . A DTX (0)
. . .
Seg( N− 2)= A DTX ( N− 1) . . . A DTX ( N− 2)
A reference segment is defined during step 260 :
Seg(ref)= A B . . . A DTX ( N− 1)
The energy for reference segment is summed during step 270 :
E ref = 1 length ( Seg ( ref ) ) ∑ Seg ( ref ) soft_bit 2
where p-bits are excluded from the integration if such bits appear in the integration window. As discussed further below in conjunction with FIG. 3 , the reference segment is known to be data, and E ref provides a reference for the energy associated with data.
During step 280 , the blind transport format detection process 200 searches for non-DTX energy using a threshold, D, as follows:
for i=0 to N−2
E = 1 length ( Seg ( i ) ) ∑ Seg ( i ) soft_bit 2
(excluding p-Bits, if present)
n=i if E/E ref <D, break if n=N−2, n=n+1
end.
Thus, the energy is computed during step 280 for each segment. As discussed further below in conjunction with FIG. 3 , if E( 0 ), for example, is approximately equal to E ref , then segment 0 is data. Generally, this process identifies the DTX and data transitions. As previously indicated, identifying the transition point from data to DTX provides a one-to-one mapping to the transport format. The transport format with index n is selected as the transport format during step 290 .
If a single transport format detected TrCH is also present in the CCTrCH, its energy shall be calculated per frame over the whole memory segment 110 , scaled with the reference segment of the explicitly detected TrCH, and compared to a threshold to decide whether data was transmitted.
FIG. 3 illustrates the execution of the exemplary blind transport format detection process 200 for a memory segment 300 where there are three (N=3) transport formats with valid CRCs. Thus, the blind transport format detection process 200 must determine which of the three potential transport formats with valid CRCs is the correct one. As shown in FIG. 3 , A DTX (i), for i between 0 and 2, identifies the location of the start of the DTX field for each of the 3 possible transport formats. As indicated above, the reference segment, Seg(ref), helps to establish a reference for the data energy. The reference segment near the base address A B of the frame is known to be data. The reference energy is compared to the energy of each potential segment created by the start of the DTX field for each of the 3 possible transport formats. For example, for A DTX ( 0 ), the portion of the memory segment 300 between the base address A B and A DTX ( 0 ) (from right to left in FIG. 3 ), would be data and the remaining portion would be DTX. If E( 0 ) is approximately equal to E ref , then transport format i is selected.
While exemplary embodiments of the present invention have been described with respect to digital logic blocks, as would be apparent to one skilled in the art, various functions may be implemented in the digital domain as processing steps in a software program, in hardware by circuit elements or state machines, or in combination of both software and hardware. Such software may be employed in, for example, a digital signal processor, micro-controller, or general-purpose computer. Such hardware and software may be embodied within circuits implemented within an integrated circuit.
Thus, the functions of the present invention can be embodied in the form of methods and apparatuses for practicing those methods. One or more aspects of the present invention can be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a device that operates analogously to specific logic circuits.
It is to be understood that the embodiments and variations shown and described herein are merely illustrative of the principles of this invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. | Methods and apparatus are provided for blind transport format detection using Discontinuous Transmission (DTX) detection. According to one aspect of the invention, the transport format that was used to transmit information is determined by identifying a transition between a Discontinuous Transmission segment and a data segment included in the transmitted information; and determining the transport format based on a location of the transition of the Discontinuous Transmission segment. A cyclic redundancy check can optionally be performed for a plurality of possible transport formats, and then the step of identifying a transition can be limited to those transport formats having a valid cyclic redundancy check. | 7 |
This invention was made with Government support under Grant No. AM-09012-17, 18 awarded by the Department of Health and Human Services. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Vitamin D and its metabolites are necessary for the maintenance of calcium homeoslasis. More than 20 metabolites have been discovered to date, varying greatly in biological activity. See, for example, U.S. Pat. No. 3,697,559 which discloses 1,25-dihydroxycholecalciferol which has vitamin D like activity in promoting intestinal calcium absorption.
The novel compounds of this invention are biologically active in terms of both bone calcium mobilization and intestinal calcium absorption and they have been shown to bind to the chick intestinal 1,25(OH) 2 D 3 receptor protein; this receptor protein is believed to mediate the biological responses to these compounds. They are therefore both of clinical importance in treatment of disease states involving calcium homeostasis disorders such as renal osteodystrophy, osteoporosis, hypoparathyroidism, and stereoid-induced osteopenia.
The two new vitamin D metabolites of this invention were isolated in pure form from separate incubations of homogenates of chick small intestinal mucosa or rat kidney employing either 1α,25-dihydroxyvitamin D 3 [28 μM] or 1α,24R,25-trihydroxy-vitamin D 3 as substrate [0.17-1.3 μM]. The newly characterized compounds and the amounts isolated in pure form from separate isolations are respectively: 1α,25-dihydroxy-24-oxo-vitamin D 3 [1,25(OH) 2 -24-oxo-D 3 ], 147 μg (from kidney), 4.2 and 40 μg (from intestine) and 1α,23,25-trihydroxy-24-oxo-vitamin D 3 [1,23,25(OH) 3 -24-oxo-D 3 ] 155 μg (from kidney), 5.9 and 34 μg (from intestine). Their structures were identified after extensive analysis, as well as direct comparison with synthetic 1,25(OH) 2 -24-oxo-D 3 . The isolation in pure form and these structural assignments for both compounds correct previous determinations which had been proposed based on impure materials [N. Ohnuma et al. (1982) J. Biol. Chem. 257, 5097-5102].
SUMMARY OF THE INVENTION
Briefly, the present invention comprises novel biologically active metabolites of vitamin D 3 , 1,23,25-trihydroxy-24-oxo-vitamin D 3 [1,23,25(OH) 3 -24-oxo-D 3 ] and 1,25-dihydroxy-24-oxo-vitamin D 3 [1.25(OH) 2 -24-oxo-D 3 ].
The present invention also includes the method of preparing the novel compounds 1,25-dihydroxy-24-oxo-vitamin D 3 and 1,23,25-trihydroxy-24-oxo-vitamin D 3 which comprises incubating the homogenates of chick small intestinal mucosa or rat kidney employing 1,25-dihydroxy vitamin D 3 or 1,24,25-trihydroxy-vitamin D 3 as substrate, and recovery of said novel compounds.
The invention further comprehends the method comprising the administration of an effective amount of 1,25-dihydroxy-24-oxo-vitamin D 3 and/or 1,23,25-trihydroxy-vitamin D 3 to humans for the treatment of diseases slates involving calcium homeostasis disorders.
An effective amount of these drugs is the same as known calcium supplements.
It is an object of this invention to provide novel biologically active metabolites of vitamin D 3 .
It is a further object to provide such compounds in pure form.
A further object of this invention is to prepare novel compounds in pure form by a new route.
These and other objects and advantages of our invention will be apparent from the detailed description which follows.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Vitamin D 3 undergoes a spectrum of metabolic transformations before exerting its biological effects Norman, A. W., Roth, J., and Orci, L. (1982) Endocrine Rev. 3, 331-366 and DeLuca, H. F. (1982) Biochem. Soc. Transactions 10, 147-158. 1,25(OH) 2 D 3 is recognized as the most active form of the vitamin in terms of enhancing intestinal calcium transport and mobilization of calcium from the skeleton. Besides its activation to 1,25(OH) 2 D 3 by 1α-hydroxylation, 25-OH-D 3 can be processed in two different pathways by the kidney: (a) to 25-OH-26,23-lactone D 3 via 23S,25(OH) 2 D 3 and 23,25,26(OH) 3 D 3 , Ishizuka, S., Ishimoto, S. and Norman, A. W. (1982) FEBS Lett. 138, 83-87; or (b) to 23,25(OH) 2 -24-oxo-D 3 via 24R,25(OH) 2 D 3 and 25-OH-24-oxo-D 3 , Mayer, E., Reddy, G. S., Kruse, J. R., Popjak, G., and Norman, A. W. (1982) Biochem. Biophys. Res. Commun. 109, 370-375; Mayer E., Reddy, G. S. Chandraratna, R. A. S., Okamura, W. H., Kruse, J. R., Popjak, G., Bishop, J. E. and Norman, A. W. (1983) Biochemistry 22, 1798-1805. Yamada, S., Ohmori, M., Takayama, H., Takasaki, Y. and Suda, T. (1983) J. Biol. Chem. 258, 457-463. 1,25(OH) 2 D 3 is known to be metabolized by enzymes located in both the kidney and intestine which are target issues of this steroid hormone, Mayer, E., Williams, G., Kadowaki, S. and Norman, A. W. (1983) In, Kumar, R. (Editor) Vitamin D. Metabolism: Basic and Clinical Aspects, Martinus Nijhoff (in press). Its metabolism may lead by hydroxylations at C-24 to 1,24R,25(OH) 3 D 3 , Kumar, R., Schnoes, H. K. and DeLuca, H. F. (1978) J. Biol. Chem. 253, 3804-3809; Ohnuma, N., Kruse, J. R., Popjak, G., and Norman, A. W. (1982) J. Biol. Chem. 257, 5097-5102, at C-26 to 1,25 S,26(OH) 3 D 3 , Tanaka, Y., Schnoes, H. K., Smith, Tanaka, Y., Schnoes, H. K., Smith, C. M. and DeLuca, H. F. (1981) Arch. Biochem. Biophy. 210, 104-109 or by formation of a γ-lactone ring between C-26 and C-23 to 1,25(OH) 2 D 3 -26,23-lactone, Ohnuma, N., Bannai, K., Yamaguchi, H., Hashimoto, Y., and Norman, A. W. (1980) Arch. Biochem. Biophys. 204, 387-391; Ohnuma, N., and Norman, A. W. (1982) Arch. Biochem. Biophys. 213, 139-147. Kumar et al found that 24 h after dosing vitamin D-deficient rats Kumar, R., Harnden, D., and DeLuca, H. F. (1975) Biochemistry 15, 2420-2423 or chicks Kumar, R. and DeLuca, H. F. (1976) Biochem. Biophys. Res. Commun. 69, 197-200 with physiological amounts of 1,25(OH) 2 -[26,27- 14 C]-D 3 , between 10 and 20% of the administered carbon-14 could be detected as 14 CO 2 . These results indicated that 1,25(OH) 2 D 3 was undergoing oxidative cleavage of the side chain. The site of the cleavage reaction appeared to be the intestine or liver, since enterocolectomy prevented this step Kumar, R. and DeLuca, H. F. (1977) Biochem Biophys Res Commun. 76, 253-258. Furthermore, it was suggested that the side chain oxidative reaction is not restricted to 1,25(OH) 2 D 3 , but may also involve 1,24,25(OH) 3 D.sub. 3, Biochemistry 15, supra,. In subsequent work, Esvelt et al. reported the presence of a water-soluble metabolite of 1,25(OH) 2 D 3 with a shortened side-chain in rat liver and intestine, which was chemically characterized as 1α-OH-24,25,26,27-tetranor-23-COOH-D 3 (calcitroic acid), Esvelt, R. P., Schnoes, H. K., and DeLuca, H. F. (1979) Biochemistry 18, 3977-3983. Also, Yamada et al. have shown that 25(OH)-24-oxo-D 3 can be 1α- and 23-hydroxylated in vitro by chick kidney homogenates, J. Biol. Chem. 258, supra,
Recently Ohnuma and Norman reported Arch. Biochem. Biophys. 213, supra, that rat small intestinal mucosa homogenates have the enzymatic capability to convert 1,25(OH) 2 D 3 to 1,24R,25(OH) 3 D 3 , 1,25(OH) 2 -26,23-lactone D 3 and another metabolite, which was preliminarily designated Peak X. Peak X was found to be the major chloroform soluble metabolite of 1,25(OH) 2 D 3 in rat intestine in vivo Ohnuma, N. and Norman, A. W. (1982) J. Biol. Chem. 257 8261-8271. Its production in vitro was markedly increased by predosing the animals with moderate or large doses of 1,25(OH) 2 D 3 , J. Biol. Chem. 257, supra. Subsequently, Peak X as well as its precursor, which was preliminarily designated 1,25-Prime, were obtained in pure form from in vitro incubations with chick small intestinal mucosa homogenates; their structures were proposed to be 1,25,26(OH) 3 -23-oxo-D 3 and 1,25(OH) 2 -23-oxo-D 3 , respectively, J. Biol. Chem. 253, supra. In the present invention we have discovered that the further metabolism of 1,24R,25(OH) 3 D 3 by chick small intestinal mocosa and rat kidney in vitro, cause the enzymatic conversion of 1,24,25(OH) 3 D 3 to two further metabolites which are 1,25(OH) 2 -24-oxo-D 3 (also called 1,24,25-Prime) and 1,23,25(OH) 3 -24-oxo-D 3 (also called Xb) based on ultraviolet absorption spectrophotometry, mass spectrometry, proton nuclear magnet resonance spectrometry and specific chemical reactions. It has been found that these two metabolites are actually present in the impure intestinal in vitro metabolites 1,25-Prime and Peak X, through error which were previously proposed to be 1,25-(OH) 2 -23-oxo-D 3 and 1,25,26(OH) 3 -23-oxo-D 3 J. Biol. Chem., 257, supra,
Turning to FIGS. 1 to 5:
FIG. 1 Panel A: Mass spectrum, of the tetra-trimethylsilyl derivative of 1,24,25-Prime [1,25(OH) 2 -24-oxo-D 3 ]. The trimethylsilyl derivative of the borohydride reduction product of 1,24,25-Prime was evaluated by mass spectrometry. The 1,24,25-Prime was isolated from incubations of rat kidney homogenates with 1,24R,25(OH) 3 D 3 . Panel B: Mass spectrum of the tetra-trimethylsilyl derivative of Peak X b [1,23,25(OH) 3 -24-oxo-D 3 ]. The trimethylsilyl derivative of Peak X b was evaluated by mass spectrometry. Peak X b was isolated from incubations of 1,24R,25(OH) 3 D 3 with rat kidney homogenates.
FIG. 2. Structures of 1,25(OH) 2 -24-oxo-D 3 (1,25-Prime, 1,24,25-Prime) and 1,23,25(OH) 3 -24-oxo-D 3 (Peak X, Peak X b ).
FIG. 3. HPLC profiles of metabolites produced in incubations of rat kidney homogenates (A) and chick intestinal mucosa homogenates (B). Top panels, migration patterns of standard compounds, measured by ultraviolet absorbance. Bottom panels, incubation of homogenates with tritium-labeled 1,25(OH) 2 D 3 , 1,24R,25(OH) 3 D 3 or 1,25(OH) 2 -24-oxo-D 3 , as indicated. A μPorasil comlumn (0.39×30 cm) was used, eluted with hexane:isopropyl alcohol (555:65, v/v) at a flow rate of 1 ml/min. Data are expressed as dpm×10 -3 per ml eluate.
FIG. 4. Proposed pathway of metabolism of 1,25(OH) 2 D 3 .
FIG. 5. Induction in intestinal mucosa of 1,25(OH) 2 D 3 metabolizing activity, in vitro after an in vivo priming dose of 1,25(OH) 2 D 3 . Vitamin D-deficient chicks (3 birds/group) were given an intravenous priming dose of 1,25(OH) 2 D 3 (1.20 nmol/100 g body weight). The animals were killed at the indicated time intervals and individual incubations (5 min) were carried out with small intestinal mucosal homogenates (10% w/v in 0.25 m sucrose) at 37° C. The incubation media contained 50 mM Tris/Cl, pH 7.4, 3.3 mM MgCl 2 , 16.7 mM L-malate, and 4.5 ml of homogenate with 15 pmol of 1,25(OH) 2 -[26,27- 3 H]-D 3 (350,000 cpm). The incubations were terminated by the addition of CHCl 3 :MeOH, 1:2. The lipid extracts of the incubations were applied directly to a HPLC μPorasil column and eluted with isopropyl alcohol:hexane (11:89). The data are presented as the mean±SD of separate time point samples.
The following Examples are presented solely to illustrate the invention.
EXAMPLE I
1,25(OH) 2 D 3 , 1,24R,25(OH) 3 D 3 and 1,24S,25(OH) 3 D 3 were supplied by Hoffmann La Roche Co., Nutley, N.J. 1,25(OH) 2 -24-oxo-D 3 was supplied by Teijin Co., Tokyo, Japan. 25-OH-[26,27- 3 H]-D 3 (specific radioactivity: 15 Ci/mmol) was supplied by Amersham/Searle (Chicago, Il.) and converted to 1,25(OH) 2 -[26,27- 3 H]-D 3 using kidney homogenates from vitamin D deficient chicks Norman, A. W. and Bishop, J. E. (1980) Methods in Enzymology: Vitamins and Co-I Enzymes, Vol. 67, 424-426. 1,24R,25-(OH) 3 -[26,27- 3 H]-D 3 , 1,25(OH) 2 -24-oxo-[26,27,- 3 H]-D 3 and 1,23,25(OH) 3 -24-oxo-[26,27,- 3 H]-D 3 were prepared enzymatically by using small intestinal mucosa homogenates of 3 week old vitamin D-deficient chicks, which were primed with 20 U 1,25(OH) 2 D 3 intravenously 6 h before sacrifice. Small intestinal mucosa homogenate (10% in 0.25M sucrose, w/v; 1.5 ml) and buffer (3 ml; 50 mM Tris-HCl, pH 7.4, 3.3 mM MgCl 2 and 16.7 mM malate, pH 7.4) were incubated with 1,25(OH) 2 -[26,27- 3 H]-D 3 (28 nM) for 30 min at 371/4 C. Purification of the metabolites produced was performed by HPLC as described below for the first isolation trial of the unlabeled metabolites.
Animals: White Leghorn cockerels obtained on the day of hatch were raised for three weeks on a diet sufficient in vitamin D before a rachitogenic diet was fed Norman, A. W. and Wong, R. G. (1972) J. Nutr. 102, 1709-1718. Two months later the first isolation trial was carried out. The chickens used for the third trial were about 8 months old. For the investigation of the metabolic pathway from 1,25(OH) 2 D 3 to 1,23,25(OH) 3 -24-oxo-D 3 , the cockerels were raised on a diet deficient in vitamin D, Arch. Biochem. Biophys. Mayer et al, supra, for 3-4 weeks before use.
Male albino Wistar rats weighing 250-300 g were kept in hanging wire cages and fed a normal rat chow.
Isolation of the metabolite
First trial
Ten chickens were given 12 nmol/100 g body weight 1,25(OH) 2 D 3 in 0.2 ml 1,2 propanediol:ethanol (1:1, v/v) intravenously. Six hours later the animals were killed by decapitation and the small intestine quickly removed and collected in ice cold saline. A 10% homogenate (w/v) of the scraped mucosa was prepared in 0.25M sucrose. The incubation was carried out at 37° for 60 min in a shaking water bath in 125 ml Erlenmeyer flasks containing 36 ml of 50 mM Tris-HCl (pH 7.4), 3.3 mM MgCl 2 , 16.7 mM malate (pH 7.4), 14 ml of the homogenate and 1,24R,25(OH) 3 D 3 (1.7×10 -7 M). The reaction was stopped by the addition of 3 volumes of chloroform:methanol, 1:1. The total lipid extracts were evaporated to dryness in vacuo by rotary evaporation, and chromatographed as shown in FIG. 6. The concentrated lipid extracts were divided into 3 equal aliquots and applied to Sephadex LH-20 columns (1.5×22 cm, Pharmacia) which were eluted with chloroform:hexane:methanol (75:23:2). The fraction from 40-100 ml was collected, pooled, evaporated to dryness in vacuo, and subjected to HPLC. A μPorasil column (0.39×30 cm, Waters Associates) was equilibrated and eluted with hexane:isopropyl alcohol (90:10, v/v), 2 ml/min. Authentic 1,25(OH) 2 D 3 eluted at 17-19 ml. The UV-absorbing material eluting at 19-23 ml (1,24,25-Prime) and 24-28 ml (Peak X b ) was collected separately and further purified by HPLC using a Zorbax SIL column (0.41×25 cm, DuPont) eluted with dichloromethane:isopropyl alcohol (90:10, v/v), 0.8 ml/min. 1,24,25-Prime eluted at 7.5-9.0 ml and Peak X b eluted at 9.5-11 ml. The total yield of the incubations from the mucosa of 10 chickens (82 g mucosa) was 4.2 μg of 1,24,25-Prime and 4.9 μg of Peak X b .
Second trial
Sixty-two rats were injected with 4 nmol 1,25(OH) 2 D 3 each in 0.2 ml 1,2-propanediol:ethanol (1:1, v/v) subcutaneously. Six hours later the animals were decapitated and the kidneys removed to ice cold saline. A 10% homogenate (w/v) was prepared in 0.25M sucrose. The incubation flasks contained 36 ml of 50 mM Tris-HCl (pH 7.4) 3.3 mM MgCl 2 , 16.7 mM succinate (pH 7.4), 14 ml of the homogenates, and 20 μg 1,24R,25(OH) 3 D 3 in 100 μl ethanol. After 60 min incubation at 37° C. in a shaking water bath, the reaction mixtures were extracted with 3 volumes of chloroform:methanol (1:1, v/v). The total lipid extracts were evaporated by rotary evaporation and applied to a Sephadex LH-20 column (3.4×32 cm), eluted with chloroform:hexane:methanol (75:23:2, v/v). Standard 1,25(OH) 2 -[ 3 H]-D 3 eluted from this column at 680-900 ml. The fraction from 500-2700 ml was collected concentrated in vacuo and applied to a second Sephadex LH-20 column (1.5×22 cm) eluted with the same solvent system. The fraction from 40-300 ml was collected and subjected to HPLC exactly as in the first isolation trial (see FIG. 6). The incubation of kidneys from 62 rats yielded 147 μg of 1,24,25-Prime and 155 μg of Peak X b .
Third trial
Peak X was prepared exactly as described by Ohnuma et al (1982) J. Biol. Chem. 257, 5097-5102, using the small intestinal mucosa from 42 chickens. Additional chromatography steps were required (as outlined in FIG. 6) to purify Peak X from the large amounts of lipids in the chloroform extracts. The incubations using the small intestinal mucosa (850 g) from 42 chickens yielded 40.2 μg of 1,25-Prime and 34.2 μg Peak X.
EXAMPLE II
Metabolism of 1,25(OH) 2 -[ 3 H]-D 3 to [ 3 H]-Peak X (chicken and [ 3 H]-Peak X b (rat) [1,23,25-(OH) 3 -24-oxo-D 3 ]
The metabolic pathway operating in the conversion of 1,25(OH) 2 D 3 to 1,23,25(OH) 3 -24-oxo-D 3 was investigated in both rat kidney and chick small intestinal mucosa. The enzyme activities were induced in vivo by dosing two animals with 1,25(OH) 2 D 3 (1 nmol/100 g body weight) 6 h before sacrifice. A 10% homogenate of each tissue was prepared in 0.25M sucrose. The incubation mixture consisted of 1 ml homogenate, 2 ml of the buffers described above (first isolation trial buffer for chick small intestinal mucosa, second isolation trial buffer for the rat kidney) and 100,000 dpm of either 1,25(OH) 2 -[26,27- 3 H]-D 3 , 1,24R,25-(OH) 3 -[26,27- 3 H]-D 3 , or 1,25(OH) 2 -24-oxo-[26,27- 3 H]-D 3 . The reactions were carried out in duplicate for 15 min at 37° C. in a shaking water bath and were then terminated by the addition of 3 volumes of chloroform:methanol (1:1, v/v). The pooled extracts were subjected to HPLC using a μPorasil column (0.39×30 cm) equilibrated and eluted with hexane:isopropyl alcohol, 90:10 (v/v) at a flow rate of 2 ml/min. The retention volumes of synthetic 1,25(OH) 2 D 3 and 1,24R,25(OH) 3 and of isolated 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 were monitored by absorbance at 254 nm. Fractions (1 ml) were collected and the radioactivity contained was determined by liquid scintillation counting of 500 μl of each fraction. The radioactive peaks were re-chromatographed on a Zorbax SIL column using dichloromethane:isopropyl alcohol, 90:10 (v/v) as a solvent system (FIG. 3).
Chemical modifications of the metabolites
Borohydride Reduction
Compound (3 μg) was incubated with 200 μl ethanol containing 0.1% potassium hydroxide with an excess of NaBH 4 for 15 h at room temperature. Then 500 μl H 2 O was added the product was extracted with 3×500 μl dichloromethane. After evaporation to dryness under a stream of nitrogen, the sample was purified by HPLC using a Zorbax SIL column (0.41×25 cm) which was eluted with dichloromethane:isopropyl alcohol (96:4, v/v) at a flow rate of 2 ml/min.
Trimethylsilylation of the metabolites
The compounds (2 μg) were dissolved in 100 μl pyridine and reacted for 60 min at 55° C. with 100 μl of N,O-bis-(trimethylsilyl)-trifluoroacetamide (BSTFA) containing 1% chlorotrimethyl silane (TMS Cl). After evaporation of the solvent under a stream of nitrogen, the sample was applied to a HPLC μPorasil column (0.39×30 cm) which was eluted with ethylacetate:hexane (2.98, v/v) at a flow rate of 0.5 ml/min. The single ultraviolet absorbing peak generated in each reaction was collected and analyzed by mass spectrometry.
Results
Chemical characterization of the in vitro metabolite Peak X b obtained from incubations with chick small intestinal mucosa homogenates substrate: [1,24R,25(OH) 3 D 3 ] (first trial)
The ultraviolet absorption spectra of 1,24,25-Prime and Peak X b (FIG. 7) and 1,25-Prime and Peak X (not shown) (taken in 95% ethanol) showed a λ max at 265 nm and a λ min at 228 nm, characteristic for the vitamin D 5,6-cis-trienechromophore.
The mass spectrum of the metabolite 1,24,25-Prime is depicted in FIG. 8A. Major ions, relative intensities and structural assignments are as follows: m/e 430, 8, M + ; 412, 37 M + -H 2 O; 394, 26, M + -2H 2 O; 376, 4, M + 3H 2 O; 287, 6, M + -side chain; 269, 8, 287-H 2 O; 251, 21, 287-2H 2 O; 152, 41, (A ring+C 6 +C 7 )+; 134, 100, 152-H 2 O. The apparent molecular ion at m/e 430 suggests the incorporation of one degree of unsaturation (e.g. formation of a cyclic ether, a carbonyl group or an olefinic unsaturation in the molecule) as compared to 1,24R,25(OH) 3 D 3 . Characteristic vitamin D cleavage ions at m/e 287, 269, 251, 152 and 134 indicate that the vitamin D nucleus is unaltered and that therefore the modification was introduced in the side chain of the molecule, Okamura, W. H., Hammond, M. L., Jakobs, J. T. C. and van Thuiji, T. (1976) Tetrahedron Let. 52, 4807-4814.
The mass spectrum of 1,25-Prime (third trial) is presented in FIG. 8B. Major ions, relative intensities and structural assignments are as follows: m/e 430, 5, M + ; 412, 38, M + -H 2 O; 394, 59, M + -2H 2 O; 376, 10, M + -3H 2 O; 269, 16, M + -side chain; 251, 42, 269-H 2 O; 152, 24, (A ring+C 6 +C 7 ) + ; 134, 59, 152-H 2 O. The spectrum of the metabolite contained relatively intense fragments at m/e 149 and 105, which are very probably due to phthalates and related contaminants, Holick, M. F., Kleiner-Bossaller, A., Schnoes, H. K., Kasten, P. M., Boyle, I. T. and DeLuca, H. F. (1973) J. Biol. Chem. 248, 6691-6696. Characteristic 1,25(OH) 2 D 3 cleavage ions at m/e 287, 269, 251, 152, and 134 illustrate that the secosteroid nucleus of 1,25(OH) 2 D 3 has remained unchanged and that the metabolic alterations have been introduced on the side chain. The apparent molecular ion at m/e 430 indicates the presence of an additional oxygen atom and one degree of unsaturation in the molecule as compared to 1,25(OH) 2 D 3 . The nature and exact location of the unsaturation was elucidated by borohydride reduction of 1,25-Prime. Subsequent HPLC analysis on a Zorbax SIL column (0.41×25 cm) which was eluted with dichloromethane:isopropanol (96:4, v/v) revealed that two compounds were produced which eluted with the same retention volume as synthetic 1,24R,25(OH) 3 D 3 (retention volume: 73 ml) and 1,24S,25(OH) 3 D 3 (retention volume: 78 ml); therefore, the unsaturation in the side chain of 1,25-Prime was established as a ketone group at C-24.
The mass spectrum of synthetic 1,24(OH) 2 -24-oxo-D 3 is shown in FIG. 8C Major ions, relative intensities and structural assignments are as follows: m/e 430, 13 M + ; 412, 41, M + -H 2 O; 394, 20, M + -2H 2 O; 376, 2, M + -3H 2 O; 287, 8, M + -side chain; 269, 8, 287-H 2 O; 251, 16, 287-2H 2 O; 152, 39 (A ring+C 6 +C 7 ) + ; 134, 100, 152-H 2 O.
The mass spectra of 1,24,25-Prime and 1,25-Prime are very similar to the spectrum obtained for authentic 1,25(OH) 2 -24-oxo-D 3 and can therefore be readily assigned to a structure 1,25(OH) 2 -24-oxo-D 3 .
The mass spectrum of Peak X b (FIG. 9A) showed major ions, relative intensities and structural assignments as follows: m/e 446, 8, M + , 428, 2.7, M + -H 2 O; 410, 10, M + -2H 2 O; 388, 6, M + -C 3 H 6 O; 370, 17, 388-H 2 O; 352, 10, 388-2H 2 O; 287, 2, M + -side chain; 269, 10, 287-H 2 O; 251, 10, 287-2H 2 O; 152, 28 (A ring+C 6 +C 7 ) + ; 134, 100, 152-H 2 O. The apparent molecular ion at m/e 446 suggests that one oxygen atom and one degree of unsaturation were incorporated into 1,24R,25(OH) 3 D 3 , which was the substrate for the enzymatic conversion. The metabolic alterations appeared to be in the side chain of the molecule since the cleavage ions at m/e 287, 269, 251, 152 and 134 indicate that the seco-steroid nucleus was unchanged. The cleavage ions at m/e 228, 370 and 352 are derived from the cleavage between C-24 and C-25 with proton transfer.
The mass spectrum of Peak X is depicted in FIG. 9B. Major ions relative intensities and structural assignments are as follows: 446, 4, M + ; 428, 12, M + -H 2 O; 410, 6, M + -2H 2 O; 388, 5, M + -C 3 H 6 O; 370, 12, 388-H 2 O; 352, 8, 388-2H 2 O; 269, 6, M + -side chain-H 2 O; 251, 10, 269-H 2 O; 153, 26, (A ring+C 6 +C 7 ) + ; 134, 100, 152-H 2 O. The characteristic fragment ions at m/e 287, 269, 251, 152 and 134 demonstrate that the seco-steroid nucleus was unchanged and that therefore the metabolic alterations must have occurred in the side chain of the molecule. The apparent molecular ion at m/e 446 suggests that two oxygen atoms and one degree of unsaturation were incorporated during metabolism in the 25-hydroxylated side chain. The cleavage ions at m/e 388, 370 and 352 are derived from the cleavage between C-24 and C-25 with proton transfer occurring. Since the major ions in this spectrum were identical to those obtained for Peak X b (obtained from incubations of 1,24R,25(OH) 3 D 3 with rat kidney homogenates and from incubations of 1,24R,(OH) 3 D 3 with chick small intestinal mucosa homogenates), the structure 1,23,25(OH) 3 -24-oxo-D 3 was assigned for the metabolite Peak X and Peak X b .
The 200 MHz proton nuclear magnetic resonance spectrum of 1,24,25-Prime is shown in FIG. 10. The presence of an intact 5,6-cis-triene system characteristic of vitamin D was indicated by signals at δ6.39 (H 6 , d, J=11.2 Hz), 6.03 (H 7 , d, J=11.2 Hz), 5.34 (H 19Z , broad s) and 5.01 (H 19E , broad s). Other characteristic signals were observed at δ4.44 (H 1 β, m), 4.24 (H 3 α, m), 1.40 (C 26 ,27 -CH 3 , s), 0.94 (C 21 -CH 3 , d, J=5.86 Hz) and 0.56 (C 18 -CH 3 , s). The chemical shift (δ1.40) of the C 25 ,27 -methyl groups in 1,24,25-Prime is of particular significance since these proteons are deshielded by 0.17 ppm relative to the equivalent protons in 1,25(OH) 2 D 3 (δ1.23). This deshielding effect strongly suggests β-carbonyl substitution at C-24 and is supportive of the assignment of 1,25(OH) 2 -24-oxo-D 3 as the structure for 1,24,25-Prime. Furthermore, a proton-NMR spectrum identical with that obtained for isolated 1,24,25-Prime was obtained for authentic chemically synthesized 1,25(OH) 2 -24-oxo-D 3 (not shown).
The 200 MHz proton-NMR spectrum of synthetic 1,25(OH) 2 -24-oxo-D 3 showed the following signals: δ6.39 (H 6 , d, J=11.2 Hz), 6.03 (H 7 , d, J=11.2 Hz), 5.34 (H 19Z , broad s), 5.01 (H 19E , broad s), 4.44 (H 1 β, m), 4.24 (H 3 α, m), 1.40 (C 26 ,27 -CH 3 , s), 0.94 (C 21 -CH 3 , d, J=5.86 Hz) and 0.56 (C 18 -CH 3 , s).
The 200 MHz proton NMR spectrum of Peak X b (FIG. 11A) clearly indicates the structure of the metabolite to be 1,23,25(OH) 3 -24-oxo-D 3 . The spectrum shows signals typical of the 5,6-cis-triene system of vitamin D, Kumar, R. and DeLuca, H. F. (1976) Biochem. Biophys. Res. Commun. 69, 197-200 at δ6.39 (H 6 , d, J+11.2 Hz), 6.02 (H 7 , d, J=11.2 Hz), 5.34 (H 19Z , broad s) and 5.01 (H 19E , broad s). The presence of hydroxyl substitution at C-1 and C-3 was indicated by single proton resonances at δ4.44 (H 1 β), m) and 4.23 (H 3 α, m). Other characteristic signals were observed at δ1.10 (C-21 methyl, d, J=6.3 Hz) and 0.57 (C-18 methyl, s). The presence in the side chain of hydroxyl substituents at C-23 and C-25 and of an oxo substituent at C-24 was clearly demonstrated by the following factors: (a) The chemical shifts (δ1.46 and 1.43) of the C-26 and C-27 methyl groups. The C-26,27 methyl signal in 1,25-(OH) 2 -24-oxo-D 3 (δ1.40) is downfield shifted by 0.17 ppm relative to the equivalent signal in 1,25(OH) 2 D 3 (δ1.23) due to the deshielding effect of β-carbonyl substitution at C-24. Also, a deshielding effect of 0.08 ppm on the C-26,27 methyl groups is observed on C-23 hydroxyl substitution (δ1.32 and 1.28 for 23S,25(OH) 2 D 3 versus δ1.22 for 25-OH-D 3 . Thus, the signals at δ1.46 and 1.43 in the spectrum of Peak X b can be assigned to the C-26,27 methyl groups of a 25-OH-D 3 side chain which also bears a carbonyl functionality at C-24 and a hydroxyl group at C- 23. (b) The presence of a single proton multiplet at λ4.65 assigned to H 23 . The effect of α-carbonyl substitution on a hydroxyl substituted methine is calculated from model compounds to be deshielding by approximately 0.5 ppm. Since the C-23 proton of 23S,25(OH) 2 D 3 appears at δ4.1, the signal at δ4.65 in the spectrum of peak X b can be reasonably assigned to the C-23 proton of a 23,25(OH) 2 -24-oxo-D 3 side chain. The complexity of the H 23 signal may be due to virtual coupling of H 23 with a set of strongly coupled protons including those at C-22 and C-21 or alternatively may be due to coupling with the hydroxyl proton at C-23 under non-exchange conditions in addition to coupling with the adjacent C-22 protons. In summary, the proton NMR spectrum of Peak X b is completely consistent with the assigned structure of 1,23,25(OH) 3 -24-oxo-D 3 .
The 200 MHz proton NMR spectrum of Peak X, obtained from incubations of 1,25(OH) 2 D 3 with chicken intestinal mucosa homogenates is shown in FIG. 11B. The signals exhibited and their assignments are as follows: δ6.39 (H 6 , d. J=11.2 Hz), 6.02 (H 7 , d, J=11.2 Hz), 5.34 (H 19Z , broad s), 5.01 (H 19E , broad s) 4.65 (H 23 , m), 4.44 (H 1 β, m), 4.23 (H 3 α, m) 1.46 and 1.43 (C-26,27-methyl, s), 1.10 (C-21 methyl, d, J=6.3 Hz), 0.57 (C-18 methyl, s). The spectrum of Peak X is identical with that obtained for Peak X b isolated from rat kidney homogenates (FIG. 11A), giving clear evidence for a structure of 1,23,25-(OH) 3 -24-oxo-D 3 for Peak X.
Evidence for the Identity of 1,24,25-Prime, 1,25-Prime and Authentic 1,25(OH) 2 -24-oxo-D.sub. 3 by HPLC Chromatography
1,24,25-Prime was isolated from in vitro incubations of 1,24R,25(OH) 3 D 3 with both chick small intestine and rat kidney; 1,25-Prime was obtained from incubations of chick small intestinal mucosa with 1,25(OH) 2 D 3 . Firstly, 1 μg of these three metabolites and of authentic 1,25(OH) 2 -24-oxo-D 3 were chromatographed separately. Then all four compounds were pooled and rechromatographed. Using a Zorbax SIL-column (0.41×25 cm) and a dichloromethane:isopropyl alcohol (97:3, v/v) solvent system 1,25-Prime, 1,24,25-Prime and 1,25(OH) 2 -24-oxo-D 3 exactly coeluted at 32.4 ml.
Results
Both new metabolites were isolated in pure form from incubations of rat kidney homogenates with 1,24R,25(OH) 3 D 3 . In order to localize the hydroxyl groups in the metabolites, trimethylsilylether derivatives were prepared. First, 1,24,25-Prime was treated with sodium borohydride. Subsequent HPLC analysis on a Zorbax SIL column (0.41×25 cm, solvent system dichloromethane:isopropyl alcohol, 96:4, v/v) showed that two compounds were produced. Two peaks of equal size appeared at retention volumes of 65 ml and 70 ml; these two compounds were co-eluted with authentic chemically synthesized 1,24R,25(OH) 3 D 3 and 1,24S,25(OH) 3 D 3 , respectively. These results indicated that the two compounds obtained from the borohydride reduction of 1,24,25-Prime were likely the two possible C24-epimers of 1,24,25(OH) 3 D 3 . Subsequent preparation of the trimethylsilylether derivative of the pooled products obtained from the borohydride reduction of 1,24,25-Prime resulted in a compound whose mass spectrum is shown in FIG. 1A. Major ions, relative intensities and structural assignments are as follows: m/e 720, 1.4, M + ; 630, 5.7, M + -HOTMS; 540, 1.2, M + -2HOTMS; 206, 13.8, [A ring+C 6 +C 7 ] + -HOTMS; 147, 5, (CH) 3 Si-O + =Si(CH 3 )2; 131, 100, C 3 H 6 OTMS + . The apparent molecular ion at m/e 720 suggests that four trimethylsiloxy groups are present in the molecule. The cleavage ion at m/e 131 (base peak) establishes the presence of a siloxy group at C-25 and shows that no further metabolic alterations have occurred at C-26 or C-27. Because this mass spectrum can reasonably be assigned to the tetra-trimethylsilyl derivative of 1,24,25(OH) 3 D 3 (9,19), the structure of this new vitamin D metabolite 1,24,25-Prime can be proposed as 1,25(OH) 2 -24-oxo-D 3 .
Peak X b was converted to a tetra-trimethylsilylether derivative. The mass spectrum of this compound is shown in FIG. 1B. Major ions, relative intensities and structural assignments are as follows: m/e 734, 2.7, M + , 644, 7.2, M + -HOTMS; 554, 0.6, M + -2HOTMS; 575, 0.3, M + -C 4 O 2 H 6 TMS; 485, 0.7, 575-HOTMS; 395, 1.6, 575-2HOTMS; 305, 1, 575-3HOTMS; 296, 0.8, (A ring+C 6 +C 7 ) + ; 206, 21, 296-HOTMS: 131, 100, C 3 H 6 OTMS + . The apparent molecular ion at m/e 734 demonstrates that four hydroxyl groups are present as trimethylsilylether derivatives in the molecule. The ion at m/e 575 strongly indicates the presence of a hydroxyl group at C-23 and that there are no further alterations below C-23. The cleavage peak at m/e 131 (base peak) establishes the presence of a hydroxyl group at carbon 25 and illustrates that no further modifications at carbon 26 or carbon 27 have occurred. Therefore, the structure of this new vitamin D metabolite is proposed to be 1,23,25(OH) 3 -24-oxo-D 3 .
FIG. 2 shows the structures of 1,24,25 Prime, or 1,25(OH) 2 -24-oxo-D 3 (Panel A), and Peak X b , or 1,23,25(OH) 3 -24-oxo-D 3 (Panel B).
Metabolic Pathway Leading from 1,25(OH) 2 D 3 to 1,23,25(OH) 3 -24-oxo-D 3 in chick small intestinal mucosa in vitro
The results of experiments carried out to elucidate the metabolic pathway leading from 1,25(OH) 2 -[26,27- 3 H]-D 3 to 1,23,25(OH) 3 -[26,27- 3 H]-24-oxo-D 3 are depicted in FIG. 3. Using kidney homogenates of vitamin D replete rats primed with 1,25(OH) 2 D 3 (FIG. 3A) or small intestinal mucosa homogenates of vitamin D-depleted chicks (FIG. 3B) which were primed with 1,25(OH) 2 D 3 , we found that when 1,25(OH) 2 -[26,27- 3 H]-D 3 was used as a substrate, three further metabolites were produced. These were identified by co-chromatography on HPLC with unlabeled material as 1,24R,25(OH) 3 -[26,27- 3 H]-D 3 , 1,25(OH) 2 -[26,27- 3 H]-24-oxo-D 3 and 1,23,25(OH) 3 -[26,27- 3 H]-24-oxo-D 3 . Furthermore, since 1,25(OH) 2 -[26,27- 3 H]-24-oxo-D 3 and 1,23,25(OH) 3 -[26,27- 3 H] -24-oxo-D 3 were also generated in the incubations with 1,24R,25(OH) 3 -[26,27- 3 H]-D 3 as substrate, it became clear that 1,24R,25(OH) 3 D 3 is an intermediate in their in vitro formation. Incubation of 1,25(OH) 2 -[26,27- 3 H]-24-oxo-D 3 with the homogenates resulted in the production of 1,23,25(OH) 3 -[26,27- 3 H]-24-oxo-D 3 and trace amounts of 1,24R,25(OH) 3 -[26,27- 3 H]-D 3 . In summary, the results described above present conclusive evidence for a metabolic pathway present in rat kidney and in chick small intestine leading from 1,25(OH) 2 D 3 to 1,24R,25(OH) 3 D 3 to 1,25(OH) 2 -24-oxo-D 3 to 1,23,25-(OH) 3 -24-oxo-D 3 (FIG. 4).
FIG. 5 presents evidence supporting the physiological relevance of the further metabolism of 1,25(OH) 2 D 3 in the chick intestine. The time course of the 1α-OH-seco-steroid metabolism after priming the animals with 1,25(OH) 2 D 3 was studied. The results indicate that by 3-6 h after the priming dose of 1,25(OH) 2 D 3 the 1,25(OH) 2 D 3 metabolizing activity has reached a maximum; this activity then decays away to baseline levels by 12 h. These results suggest the presence of a C-24 oxidation pathway for 1,25(OH) 2 D 3 present in the intestine as well as the kidney.
This report describes the in vitro production, isolation, and chemical characterization of 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 which were obtained from incubations of rat kidney homogenates and chicken small intestinal homogenates. The structural assignments are based on ultraviolet absorption spectroscopy, mass spectrometry, and proton nuclear magnetic resonance spectrometry. After induction of the enzymes(s) by priming the animals with high doses of 1,25(OH) 2 D 3 [FIG. 5 and (17)], 1,23,25(OH) 3 -24-oxo-D 3 was produced from 1,25(OH) 2 D 3 , 1,24R,25(OH) 3 D 3 , and from 1,25(OH) 2 -24-oxo-D 3 by incubation with chick small intestinal mucosa homogenates and rat kidney homogenates. 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 are in vitro metabolites of 1,25(OH) 2 D 3 , produced enzymatically by sequential hydroxylation at C-24, oxidation of the C-24 hydroxyl group, and hydroxylation at C-23.
The metabolites produced by incubation of 1,25(OH) 2 D 3 with chick small intestinal homogenate (1,25-Prime and Peak X) are 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 , and not 1,25(OH) 2 -23-oxo-D 3 and 1,25,26(OH) 3 -23-oxo-D 3 as previously proposed, Ohnuma, N. et al (1982) J. Biol. Chem. 257, 5097-5102.
The purification of 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 from incubations of homogenates of 62 rat kidneys required two Sephadex LH-20 chromatography steps and two HPLC steps, to yield 147 μg (1,24,25-Prime) and 155 μg (Peak X b ) respectively. These incubation products comigrated in two HPLC systems with previously isolated metabolites, 1,25-Prime and Peak X respectively, Ohnuma, N., et al (1982) J. Biol. Chem. 257, 5097-5102, which were generated from 1,25(OH) 2 D 3 by incubation with chick small intestinal mucosa hemogenates. The higher lipid content of the intestinal mucosa homogenates necessitated additional HPLC purification steps to obtain 40.2 μg of 1,25-Prime and 34.2 μg of Peak X from the intestinal homogenates of 42 chickens. Structural analyses of 1,25-Prime and 1,24,25-Prime by mass spectrometry and proton NMR spectrometry and the chemical reduction of 1,24,25-Prime to 1,24,25(OH) 3 D 3 clearly showed that both products are identical to 1,25(OH) 2 -24-oxo-D 3 . Similar analyses of Peak X and Peak X b showed that these metabolites are 1,23,25(OH) 3 -24-oxo-D 3 .
While the physiological significance, in vivo, of 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 are not yet known with certainty it seems likely that they represent a means of further metabolism and inactivation of the highly biologically active 1,25(OH) 2 D 3 . As shown in FIG. 5, priming doses of 1,25(OH) 2 D 3 given in vivo result in the rapid induction by 3-6 h of the enzymes necessary for the further metabolism of 1,25(OH) 2 D 3 . It also seems significant that this enzymatic activity is present in target tissues; both the intestine and kidney have been shown to contain receptors for 1,25(OH) 2 D 3 and to produce biological responses including induction of a calcium binding protein (CaBP), Norman A. W., Roth, J., and Orci, L. (1982) Endocrine Rev. 3, 331-366 and Mayer, E., Williams, G. Kadowaki, S. and Norman A. W. (1983) In, Kumar, R. (Editor) Vitamin D Metabolism: Basic and Clinical Aspects, Martinus Nijhoff (in press). Thus, it is possible to propose that the C-24 oxidation pathway which involves the sequential 24-hydroxylation, 24-hydroxyl oxidation and 23-hydroxylation of 1,25(OH) 2 D 3 is an important physiological means of controlling the concentration of hormone and thus the biological response in the target issue.
The biological activity of the vitamin D 3 metabolites, as measured by intestinal calcium absorption and bone calcium mobilization in vitamin D-deficient chicks, decreases in the order 1,25(OH) 2 D 3 >1,24R,25-(OH) 3 D 3 >1,25(OH) 2 -24-oxo-D 3 >1,23,25(OH) 3 -24-oxo-D 3 . These results also can be interpreted as supportive evidence for the biological significance of the proposed C-24 pathway of the side chain metabolism of 1,25(OH) 2 D 3 , leading perhaps to calcitroic acid, Esvelt, R. P., Schnoes, H. K., and DeLuca, H. F. (1979) Biochemistry 18, 3977-3983. Both 1,25(OH) 2 -24-oxo-D 3 and 1,23,25(OH) 3 -24-oxo-D 3 were also found to bind to the chick intestinal 1,25(OH) 2 D 3 receptor, being 98% and 28%, respectively, as effective as 1,25(OH) 2 D 3 in competition for ligand binding, Mayer, E., Bishop, J. E., Ohnuma, N. and Norman, A. W., (1983) Arch.Biochem.Biophys. 224, 671-676. This result is indicative of a possible biological significance of these metabolites in the regulation of calcium and/or phosphorus homeostasis.
Two pathways are now apparent for the metabolism of 1,25(OH) 2 D 3 in its target tissues intestine and kidney. One pathway leads to 1,25(OH) 2 D 3 -26,23-lactone, Ohnuma, N., Bannai, K., Yamaguchi, H., Hashimoto, Y., and Norman, A. W. (1980) Arch. Biochem, Biophys. 204, 387-391 and Ohnuma, N., and Norman, A. W. (1982) Arch. Biochem. Biophys. 213, 139-147, whose biological function is as yet unknown. By analogy to the metabolism of 25-OH-D 3 to 25-OH-D 3 -26,23-lactone, Mayer, E., Reddy, G. S., Kruse, J. R., Popjak, G., and Norman, A. W. (1982) Biochem. Biophys. Res. Commun. 109, 370-375 and Napoli, J. L. Pramanik, B. C., Partridge, J. J., Uskokovic, M. R. and Horst, R. L. (1982) J. Biol. Chem. 257, 9634-9639, C-23 hydroxylation of 1,25(OH) 2 D 3 followed by C-26 hydroxylation and oxidation to the C-26 acid can be postulated as intermediate steps. The second pathway, proposed here, leads from 1,25(OH) 2 D 3 by C-24 hydroxylation to 1,24R,25(OH) 3 D 3 , Kumar, R., Schnoes, H. K. and DeLuca, H. F. (1978) J. Biol. Chem. 253, 3804-3809 and Ohnuma, N. and Norman, A. W. (1982) J. Biol. Chem. 257, 8261-8271, followed by oxidation of the C-24-hydroxyl group to yield 1,25(OH) 2 -24-oxo-D 3 and subsequent C-23 hydroxylation to give 1,23,25(OH) 3 -24-oxo-D 3 . Both pathways may lead through side chain cleavage to the currently accepted final inactivation product of 1,25(OH) 2 D 3 , 1α-OH-24,25,26,27-tetranor-23-COOH-D 3 (calcitroic acid) Esvelt, R. P., Schnoes, H. K., and DeLuca, H. F. (1979) Biochemistry 18, 3977-3983.
Having fully described the invention it is intended that it be limited only by the lawful scope of the appended claims. | Novel biologically active metabolites of vitamin D 3 , 1,23,25-trihydroxy-24-oxo-vitamin D 3 (1,23,25(OH) 3 -24-oxo-D 3 ); and 1,25,-Dihydroxy-24-oxo-vitamin D 3 (1,25(OH) 2 -24-oxo-D 3 ). Also the method of preparing these novel metabolites of vitamin D 3 . The use of these compounds in humans for the treatment of disease states involving calcium homeostatic disorders by the administration of an effective amount of said compounds. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
In systems of the type that transfer data it is often necessary or desirable to generate from noise corrupted data a clock signal synchronized with that data. This is often done in telecommunication systems and in magnetic data storage systems. Circuits which provide such a synchronized clock are commonly called data tracking phase locked loops.
A data tracking phase locked loop is a feedback control system which minimizes the phase error between transitions in noisy data and the transitions of a variable frequency local oscillator. The minimization is achieved by varying the frequency of the local oscillator in accordance with a measured phase error. The phase error detection portion of the loop should meet the following criteria:
1. The phase detector output should have a low content of harmonics of the clock frequency. Otherwise, excessive filtering may be required that can unduly dampen the response of the loop to rapid phase error excursions.
2 The phase detector should tolerate normally absent data pulses (i.e., logical zeros) without generating a false phase error.
In addition, it would be useful in the testing and repair of equipment employing data tracking phase locked loops if the phase error information were made available to the system itself, particularly if computer or microprocessor controlled equipment are involved. Such phase error information could serve as a figure of merit for the operation of the data transfer channel, and allow the system to monitor or even log that aspect of its own performance. This would be very useful as a diagnostic aid both in the factory and in the field.
In a digital system it would be advantageous if the phase error information were also digital. The advantage would be greater still if the manner of obtaining the phase error were inherently digital in nature so that an expensive high speed analog-to-digital conversion can be avoided. Furthermore, digital phase error information can be arithmetically manipulated by "digital filters" within the phase locked loop, giving the designer added flexibility in choosing the response characteristics of the loop.
Furthermore, it would be advantageous if the data tracking phase locked loop itself were capable of readily attaining the phase locked condition without sweeping the frequency of the local oscillator or requiring a special preamble in the data, as in some prior data tracking phase locked loops.
Accordingly, it is an object of the present invention to provide a data tracking phase locked loop that incorporates a phase detector that produces a low content of harmonics of the clock frequency.
Another object of the invention is to provide a data tracking phase locked loop that tolerates normal absence of data pulses without generating a false phase error.
Another object of the invention is to provide a data tracking phase locked loop wherein the phase error detector inherently produces a digital output.
Another object of the invention is to provide a data tracking phase locked loop that incorporates a digital filter within its feedback loop.
It is a further object of the invention to provide a data tracking phase locked loop that readily attains the phase locked condition without sweeping the local oscillator or requiring a special preamble in the data.
These objects of the invention are met by data tracking phase locked loops constructed in accordance with the following summary.
A variable frequency oscillator runs with a center frequency that is an integral multiple n times greater than the nominal frequency of the data. A counter of modulus n continuously counts the oscillations of the variable frequency oscillator, dividing the period of the phase varying data into approxiimately n parts. The value of the count is captured each time a data pulse occurs. Once the loop is in lock, if the data were to remain absolutely stable each captured value would be the same as its predecessor. As phase shifting of the data occurs the value of the captured count increases or decreases in kind. Captured counts may be first digitally filtered or used directly to drive a digital-to-analog converter, whose output is analog filtered before being used to control the variable frequency oscillator. For example, a decrease in the captured count means the data arrived sooner and causer a voltage change in the digital-to-analog converter that causes the variable frequency oscillator to operate at a higher frequency, thus tracking the shift in the phase of the data.
A phase corrected clock is easily obtained once the variable frequency oscillator tracks the phase variations in the data; one way is to produce a signal in relation to the occurrence of a particular bit or particular count in the counter.
The loop is readily placed in phase lock by briefly operating it in a rapid phase error acquisition mode wherein the counter is set to n/2 each time a data pulse is received. During this mode of operation the loop becomes a frequency loop that approximates the behavior of a phase locked loop.
Since the output of the digital-to-analog converter is stable except when there is a change in the value of a captured count, and since the digital-to-analog converter quickly stabilizes following such changes, the detected phase error represented by the output of the digital-to-analog converter is low in harmonics of the clock frequency.
Since the counter has a modulus of n it simply "rolls over" and begins counting anew if a data pulse is absent; the previous captured count remains unaltered and no false phase error is generated.
Since the phase error originates as a count captured from a counter, the digital phase error information is inherently digital.
Since digital phase error information is readily available it may be digitally filtered before being used to control the variable frequency oscillator via the digital-to-analog converter.
Since the behavior of this circuit as a frequency loop approximates that of a phase locked loop, briefly operating the data tracking loop in a frequency loop mode before entering the phase locked mode readily allows the loop to attain the phase locked condition without sweeping the local oscillator or employing a preamble in the data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a data tracking phase locked loop constructed according to a preferred embodiment of the invention, but without incorporating a digital filter.
FIG. 2 is a block diagram of a data tracking phase locked loop constructed according to a preferred embodiment of the invention, and incorporating a digital filter.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in FIG. 1 is a block diagram of a data tracking phase locked loop constructed in accordance with a preferred embodiment of the invention. The output 5 of a variable frequency oscillator 4 is fed to a clock input 6 of a D-type latch 3 and also to a clock input 11 of a counter 10. The outputs 12 of the counter are fed to a master storage register 9 and also to a unique count detector 13. Input data 1 is fed to a D input 2 of the latch 3. A Q output 7 of the latch 3 is fed to a clock input 8 of a master storage register 9, as well as to a one shot 24. The outputs 14 of the master storage register 9 represent the phase error in digital form and are made available to external circuitry as well as being supplied to a digital-to-analog converter 15. The output 16 of the digital-to-analog converter 15 represents the phase error in analog form and is supplied to external circuitry as well as to the signal input of a filter 17. The output 18 of the filter 17 is fed to a control input of the variable frequency oscillator 4.
The output 19 of the count detector 13 is a signal transitioning in response to the occurrence of some preselected arbitrary count in the counter 10 and represents a phase error corrected clock.
The output of one shot 24 is connected to one input of an AND gate 20. Another input to AND gate 20 is a signal 21, FAST ACQUISITION ENABLE, which is also supplied as a control input to the filter 17. The output of the AND gate 20 is supplied to a parallel load input 22 of the counter 10. Lines 23 represents a count to be parallel loaded into the counter 10.
The operation of the circuit of FIG. 1 is as follows. The input data 1 has a nominal frequency f. The variable frequency oscillator 4 has a center frequency that is an integral number n times greater than f. In one actual circuit where the input data is from a magnetic disc f is approximately 500 kHz and n is 256. The counter 10 counts with a modulus of n the oscillations of the variable frequency oscillator 4; that is, it counts from zero to n-1 and starts over with zero as the next count. The value of the current count in the counter 10 is captured with a master storage register 9 each time there is a pulse in the input data 1.
The latch 3 is a D-type flip-flop whose Q output 7 is set to the logical value of the D input 2 each time clock input 6 goes low. Each time the output 5 of the variable frequency oscillator 4 goes low the latch 3 captures the current logical value of the input data and presents that value on the Q output 7. The latch 3 thus acts to synchronize possible asynchronous transitions in the input data 1 with the transitions in the output 5 of the variable frequency oscillator 4. The Q output 7 represents synchronized input data that may be applied to other elements of the circuit that are clocked in synchronism with the transitions from the variable frequency oscillator 4. In particular, the master storage register 9 uses the output of the synchronizing latch 3 to capture the current value of the count in the counter 10. The counter is not reset by this, and continues to count without interruption.
For the sake of further explanation, assume that the input data is phase stable and is exactly of a frequency that equals the frequency of the variable frequency oscillator divided by n. Some pulses may be legitimately absent from the data, however. Further assume that the count in the counter was n/2 when the previous count was captured by the master storage register. Under these conditions all subsequent counts captured by the master storage register will also be n/2.
Retaining those assumptions, it is seen that the count detector 13 produces an output 19 that may be used as a clock that is in synchronism with the input data. The relative phase of the output 19 and the input data 1 is determined by selecting which value of the count is detected. A clock for the input data could also be formed by a separate divider (not shown) driven by the variable frequency oscillator.
The digital-to-analog converter produces an analog control signal 16 in relation to the count in the master storage register. When the count is n/2 the amplitude of the control signal is zero. When the count is less than or greater than n/2 the polarity of the control signal changes in kind, while its amplitude varies in proportion to the difference between the count and n/2.
The output of the digital-to-analog converter is filtered by analog filter 17 and then applied to the variable frequency oscillator. The filter 17 further defines the response characteristics of the loop. The variable frequency oscillator is adjusted to run at exactly the frequency assumed above (n times f) when the amplitude of the signal at its control input is zero.
Thus the loop as described above, with its attendant assumptions, is in equilibrium. That is, there is little or no difference between the phase of the input data during its immediately preceeding cycles and the phase of the input data during the current cycle. This results in no change to the captured count, further resulting in a nonchanging output from the digital-to-analog converter and a nonchanging frequency from the variable frequency oscillator. In the present embodiment the circuit parameters have been chosen such that when the loop is in equilibrium the captured count is exactly n/2 and the corresponding frequency of the variable frequency oscillator is exactly n-times the expected center frequency of the input data. As shown below, changes in the phase or frequency of the input data cause a loss of equilibrium resisted by the loop by minimizing changes in the captured count of the counter.
Now assume that one or more data pulses occur at a faster rate than before. This will diminish the count in the counter, producing a corresponding change in the output 16 of the digital-to-analog converter. The polarity of the change is chosen such that it will cause an increase in frequency of the variable frequency oscillator. This tends to increase the count in the counter back towards n/2. Similarly, a decrease in frequency of the variable frequency oscillator causes a decrease in the count whenever the count goes above n/2 due to slowing of the rate of the input data.
Thus, the loop is a negative feedback loop that nulls the difference between the current count in the counter 10 and the value n/2, by continuously adjusting the variable frequency oscillator to oscillate at a frequency n times the current input data rate, even though that rate may vary. The counter 10 and count detector 13 combine to divide that frequency by n and produce a phase error corrected clock that tracks frequency and phase variations in the input data.
Absent data pulses do not alter either the equilibrium or the null seeking described above. First, because an absent data pulse by its very absence prevents a new value from being captured in the master storage register, and second, because the modularity of the counter "absorbs" by its roll-over the count that would have been captured, and creates a subsequent count as if its predecessor had been captured anyway.
Phase error information in digital form is available from the output 14 of the master storage register. Phase error information in analog form is available from the output 16 of the digital-to-analog converter.
The circuit of FIG. 1 can also be operated in a rapid phase error acquisition mode by supplying to the circuit a signal 21 called FAST ACQUISITION ENABLE. The presence of this signal does two things. First, it acts upon the control input to the filter 17 to reduce the delay through the filter. Second, it enables narrow pulses from the one shot 24 to be felt at the parallel load input 22 of the counter 10. Thus, each cycle of the input data causes the counter 10 to be preset to the value of the parallel load count 23, which is chosen to equal the design value of the captured count when the loop is in equilibrium. In the present embodiment that is n/2.
The actual count in the counter 10 is still transferred to the master storage register 9 each time a cycle of the input data occurs. Thus, while in the rapid phase error acquisition mode the circuit acts as a frequency loop, producing a digital output 14 and an analog output 16 that are proportional to the difference between the frequency of the input data and the frequency of the variable frequency oscillator divided by n. The variable frequency oscillator tracks (times a factor of n) the frequency of the input data. Some phase difference may occur.
When preceeded by a brief period of operation in the rapid phase error acquisition mode the loop subsequently nulls itself more quickly in the normal phase tracking mode than if the counter were merely allowed to contain an arbitrary count, or a count of zero, when circuit operation commenced. That is, the captured count begins immediately to approximate the difference between current loop conditions and those of true equilibrium as described above. Once the loop stabilizes in the rapid phase error acquisition mode the signal FAST ACQUISITION ENABLE may be removed and normal data-phase tracking attained with minimal disturbance to the loop.
An alternate embodiment of the invention is shown in FIG. 2. The circuit of FIG. 2 differs from that of FIG. 1 in that a circuit element 26, which may be either a slave storage register or a digital filter, receives the outputs 14 of the master storage register 9. The output 19 of the count detector 13 is connected to a clock input 25 of the slave storage register or digital filter 26. The outputs 27 thereof are connected to the digital-to-analog converter, and also represent the phase error in digital form.
The operation of the circuit of FIG. 2 is similar in most respects to that of the circuit of FIG. 1. The difference is that once each time during the counting cycle of the counter 10 the previously captured count is transferred into the slave storage register or digital filter. This offers the advantage that the digital-to-analog converter is isolated from sudden changes in phase in the input data that could produce two closely occurring outputs of the synchronizer 3 with widely differing counts in the counter. By allowing the input to the digital-to-analog converter to change only at regular intervals related to the count in the counter 10 a more stable output from the digital-to-analog converter is produced, and that output is then lower in harmonics.
Circuit elements 26 may also be a digital filter whose digital output 27 is arithmetically related to the preceeding sequence of captured counts stored in the master storage register 9. | A counter of modulus n counts the oscillations of a variable frequency oscillator whose center frequency is n-times the nominal frequency of digital data having phase variations. The occurrence of a selected value of the count may be taken as a phase corrected clock for the digital data. Differences between successive values in the counter as pulses of the digital data occur indicate shifts in phase thereof, while the modularity prevents absent data pulses from contributing to the phase error. Successive counts are captured, made available as phase error information in digital form, and used to drive a digital-to-analog converter whose output controls the variable frequency oscillator. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is a continuation and claims the benefit of the filing date of an application entitled, “Generalized Identity Mediation and Propagation” Ser. No. 12/826,614, filed Jun. 29, 2010, assigned to the assignee of the present application, and herein incorporated by reference.
FIELD OF DISCLOSURE
The claimed subject matter relates generally to computer security and, more specifically, to identity mediation between client applications and server applications.
SUMMARY
Provided are techniques for providing security in a computing system with identity mediation policies that are enterprise service bus (ESB) independent. In a typical computing system of today, a number of applications may be connected to a number of service providers via a mediator component. A mediator component may be an ESB that performs service-level operation such as message brokering, identity mediation, and transformation to enhance interoperability among service consumers and service providers. A mediator component may also delegate identity related operations to a token service or handler. Identity mediation may include such operations as identity determination, or “identification,” authentication, authorization, identity transformation and security audit.
Provided is a method of mediation in a computing system to provide secure access to a server application, comprising loading, into an identity mapping module, an identity mapping policy for specifying correspondence between a first set of identities and a second set of identities, wherein the first set of identities correspond to a party requesting a service, in conjunction with the client application, from the server application and the second set of identities correspond to the party and the server application; loading, into an authentication module, an authentication policy for authenticating a first identity of the first set of identities and a second identity of the second set identities, wherein the first identity and the second identity are mapped to each other by the identity mapping module with respect to the client application and the server application; loading, into an authorization module, an authorization policy for authorizing the second identity for access to the server application; and providing the service to the party based upon a mapping of the first identity to the second identity by the mapping module, an authentication of the first and second identities by the authentication, module and an authorization of the second identity by the authorization module.
This summary is not intended as a comprehensive description of the claimed subject matter but, rather, is intended to provide a brief overview of some of the functionality associated therewith. Other systems, methods, functionality, features and advantages of the claimed subject matter will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the claimed subject matter can be obtained when the following detailed description of the disclosed embodiments is considered in conjunction with the following figures, in which:
FIG. 1 is one example of a computing system that may implement an Enhanced Enterprise Service Bus (EESB) that implements the disclosed technology.
FIG. 2 is a block diagram of the EESB, first introduced in FIG. 1 , in more detail.
FIG. 3 is a block diagram of a high-level model for a mediation language employed by the EESB of FIGS. 1 and 2 to implement a mediation policy.
FIG. 4 is a block diagram of a model of an identification policy of the mediation language of FIG. 3 employed by the EESB of FIGS. 1 and 2 .
FIG. 5 is a block diagram of a model of an authorization policy of the mediation language of FIG. 3 employed by the EESB of FIGS. 1 and 2 .
FIG. 6 is a block diagram of a model of a mapping policy of the mediation language of FIG. 3 employed by the EESB of FIGS. 1 and 2 .
FIG. 7 is a flowchart of Setup EESB process that is an example of one processing aspect of the claimed subject matter.
FIG. 8 is a flowchart of an Operate EESB process that is an example of one processing aspect of the claimed subject matter.
DETAILED DESCRIPTION
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code, or logic, embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
As the Inventors herein have recognized, different applications may have different requirements with respect to identity mediation and each particular enterprise service bus (ESB) platform may have a different approach as to how identity mediation operations are configured and implemented. Therefore, the management of such an environment with the intent to consistently apply security policies is difficult. For example, a change in a security policy may require changes to applications, a process that can be redundant, error prone and time consuming. Other issues arise in a migration from one ESB to another, which may require recreation of all identity mediation policies from scratch on the new platform.
Issues with current ESB configurations include, but are not limited to:
1) Changes in security policy need to be implemented in each application that uses the ESB; this change is complex and difficult to implement in light of security audit requirements; 2) Typically, the first place in which authorization and identity mapping occur is in an information application, which is too late if information-centric applications are integrated across enterprise boundaries because a potential attacker may already be in a trusted zone of the enterprise; 3) Token service and specialized security handlers cannot be easily transferred from one ESB platform to another even if security policies are implanted in the ESBs; and 4) Information-centric applications lack powerful security policy enforcement capabilities, which may compromise security due to lack of integration among the ESB, policy tools and the information-centric application.
Turning now to the figures, FIG. 1 is one example of a computing system architecture 100 that may implement an Enhanced enterprise service bus (EEBS) in accordance with the disclosed technology. A client system 102 includes a central processing unit (CPU) 104 , coupled to a monitor 106 , a keyboard 108 and a mouse 110 , which together facilitate human interaction with computing system 100 and client system 102 . Also included in client system 102 and attached to CPU 104 is a data storage component 112 , which may either be incorporated into CPU 104 i.e. an internal device, or attached externally to CPU 104 by means of various, commonly available connection devices such as but not limited to, a universal serial bus (USB) port (not shown). Data storage 112 is illustrated storing an example of a computer application, i.e. app_ 1 114 , which is hosted by client system 102 and employs the claimed subject matter for mediation services. It should be noted that a typical computing system would include more than one application, but for the sake of simplicity only one is shown.
Client system 102 is communicatively coupled to a local area network (LAN) 118 , which is coupled to the Internet 120 . Also coupled to LAN 118 is an additional client system 122 and a server 125 . Although not shown, client system 122 and server 125 would also typically include a CPU, monitor, keyboard, mouse and data storage. Client system 122 is illustrated hosting a second application, i.e. app_ 2 124 , which is stored on a data storage (not shown) and executed on a CPU, or “processor,” (not shown), both associated with server 122 .
Server 125 is also illustrated with an enhanced enterprise service bus (EESB) 126 , which is stored on data storage (not shown) and executed on a processor (not shown) associated with server 125 . EESB 126 may utilize a token handler 128 and a security handler 130 to implement mediation service in accordance with the claimed subject matter. EESB 126 is described in more detail below in conjunction with FIGS. 2-8 . Also communicatively coupled to the Internet 120 and therefore LAN 118 , client systems 102 and 122 , server 125 and EESB 126 are two service providers, or “servers,” i.e. a service provider 132 and a service provider 142 . Although not shown, servers 132 and 142 would also, like client system 102 and 122 , typically include a CPU, monitor, keyboard, and mouse to enable human interaction. Server 132 is coupled to a data storage 134 , which stores a service application, or “service,”, i.e. ser_ 1 136 , and server 142 is coupled to a data storage 144 , which stores a service, i.e. ser_ 2 146 . Services 136 and 146 each execute on a processor (not shown) associated with servers 132 and 142 , respectively.
Although in this example, clients 102 , 122 , server 125 , EESB 126 and servers 132 and 142 are communicatively coupled via LAN 118 the Internet 120 , they could also be coupled through any number of communication mediums such as, but not limited to, additional LANs (not shown) or direct or indirect, wired or wireless connections. Further, it should be noted there are many possible computing system configurations, of which computing system 100 is only one simple example. Throughout the Specification, clients 102 and 122 applications 114 and 124 , servers 125 , 132 and 142 and services 136 and 146 are employed as examples of computing components that may implement and/or utilize the claimed subject matter.
FIG. 2 is a block diagram of EESB 126 , first introduced above in FIG. 1 , in more detail. EESB 126 includes an input/output (I/O) module 150 , an EESB configuration module 151 , an Identification module 152 , an Authentication module 153 , an Authorization module 154 , an Identity Mapping module 155 , an Audit module 156 and a Transformation and Routing module 157 . For the sake of the following examples, EESB 126 is assumed to execute on server 125 ( FIG. 1 ). In the alternative, EESB 126 may be stored on and execute on nearly any computing device such as computer 102 ( FIG. 1 ) and servers 132 and 142 .
It should be understood that the claimed subject matter can be implemented in many types of computing systems and data storage structures but, for the sake of simplicity, is described primarily in terms of computer 102 , server 125 and the other elements of system architecture 100 ( FIG. 1 ). In addition, the representation of EESB 126 in FIG. 2 is a logical model. In other words, each of components 150 - 157 may be stored in the same, separate or multiple files and loaded and/or executed within system 100 either as a single system or as separate processes interacting via any available inter process communication (IPC) techniques.
I/O module 150 handles any communication EESB 126 has with other components of system 100 . EESB configuration module 151 includes processing logic and stores parameters that control the operation of EESB 126 . Module 151 is described in more detail below in conjunction with FIG. 7 . Identification module 152 enforces a policy for identifying a party requesting mediation by EESB 126 . Module 152 is described in more detail below in conjunction with FIGS. 3 , 4 and 8 . Authentication module 153 enforces a policy for verifying the identity identified by Identification module 152 . Module 153 is described in more detail below in conjunction with FIGS. 3 and 8 . Authorization module 154 enforces an authorization policy for permitting an authorization operation to permit an access control check. Module 154 is described in more detail below in conjunction with FIGS. 3 , 4 and 8 .
Identity Mapping module 155 enforces identity mapping rules. Identity mapping rules may include, but are not limited to, identity replacement, simple identity mapping (value to value), directory-based mapping (value to lookup value) and rule-based identity mapping. Module 155 is described in more detail below in conjunction with FIGS. 3 , 6 and 8 . Audit module 156 defines the operation for the logging and audit of service requests. Module 156 is described in more detail below in conjunction with FIGS. 3 and 8 .
Transformation and routing module 157 is employed for standard ESB processes such as, but not limited to, transformation, e.g. additional operations that may be performed on a service request, and routing. Other functions executed by EESB 126 that are not listed in conjunction with specific modules include, but are not limited to, service response filtering, service response masking, security token replacement, security token validation and verification, decryption of inbound security tokens, encryption of outbound security tokens and the implementation of security policy combination rules. Module 157 is described in more detail below in conjunction with FIGS. 3 and 8 .
FIG. 3 is a block diagram of a high-level model for a mediation language model 202 employed by EESB 126 of FIGS. 1 and 2 to implement a mediation policy in conjunction with system 100 ( FIG. 1 ). A MediationPolicySet data structure 204 is the root element of the disclosed identity mediation policy language. MediationPolicySet 204 stores references to all the identity mediation policy policies implemented by EESB 126 as defined by an appropriate administrator. A MediationPolicy 206 represents a complete instance of a policy for controlling identity mediation tasks. Some examples of specific policies that may be selected for a particular task of MediationPolicy 206 are listed below in conjunction with FIGS. 3-6 . A MediationPolicy ID 207 is the part of MediationPolicy 206 that identifies a specific mediation policy. MediationPolicyID 207 may store a reference to an identification policy already in use, i.e. an IdentificationPolicy 210 , or reference a policy that has been previously declared, i.e. IdentificationPolicyRef 238 (see FIG. 4 ).
It should be noted that lines that connect elements of FIGS. 3-6 include numbers that indicate a relationship between any two particular elements. For example, the line between MediationPolicySet 204 and MediationPolicy 206 has the character ‘1’ at both ends. These characters indicate that elements 204 and 206 have a one-to-one relationship, i.e. for each instance of element 204 there is one instance of element 206 . Other characters employed in this fashion include a ‘*’ character and a “0..1” symbol. The ‘*’ character indicates that the corresponding element, i.e. the particular element closest to the number, many have many instances and the “0..1” symbol indicates that there may be either 0 or 1 of the corresponding element. For example MediationPolicy 206 and a Transformation data structure 228 have a one-to-many relationship.
MediationPolicy 206 has a one-to-one relationship with Identification 210 , which defines how to determine the identity of a particular service consumer. Element 210 stores an IdentificationMethod attribute (not shown) that indicates the selected identification mechanism. In this example elements 206 and 210 have a one-to-one relationship. Examples of some possible identification mechanisms include, but are not limited to, a web services-security (WS-Security) username token, a client IP address, a lightweight third-party authentication (LTPA) mechanism, a security assertion markup language (SAML) token, a custom XPath expression applied to the request, a Kerberos AP-REQ from Simple and Protected GSSAPI Negotiation Mechanism (SPNEGO) token and a hypertext transfer protocol (IMP) Authentication header. A PolicyCombiningAlgorithm element 211 provides a mechanism for combining multiple identification policies in the event two or more policies are specified, by, for example, specifying which one or which, multiples in any particular order should be executed. Identification 206 is described in more detail below in conjunction with FIG. 4 .
MediationPolicy 206 has a one-to-one relationship with. Authentication 214 , which defines a method of authenticating, or verifying, the identity as determined by the method specified by Identification 210 . Element 214 may specify a new authentication policy or reference a policy that has been previously declared. An authentication policy contains an AuthenticationMethod attribute (not shown) that indicates one or more authentication mechanisms. Examples of possible authentication mechanisms include, but are not limited to, binding to a lightweight directory access protocol (LDAP) server, validating a LTPA token, validating a SAML assertion, using a SAML server for a SAML authentication statement, using a TIVOLI® access manager server or a WS-Trust server and validating a signer certificate for a digitally signed request. A PolicyCombiningAlgorithm element 215 provides a mechanism for combining multiple authentication policies in the event two or more policies are specified, by, for example, specifying which one or which multiples in any particular order should be executed. In an alternative embodiment, element 215 may enforce an authentication policy with respect to another module's policy. For example, a user who is authenticated with a private key may be allowed to access one particular service while a user authenticated with a password is not.
MediationPolicy 206 has a one-to-many relationship with an Authorization 216 , each of which defines a particular method of authorizing execution of a request from a service customer, provided the service customer has been identified, as explained above in conjunction with element 210 , and the identity authenticated, as described above in conjunction with element 214 . Element 216 may specify a new authorization policy or reference a policy that has been previously declared. An authorization policy contains an AuthorizationMethod attribute (not shown) that indicates one or more authorization mechanisms. Examples of possible authorization mechanisms include, but are not limited to, using an extensible access control markup language (XACML) policy decision point, checking for membership in a LDAP group, generating a SAML authorization query and calling an authorization (AZN) application programming interface (API). A PolicyCombiningAlgorithm element 217 provides a mechanism for combining multiple authorization policies in the event two or more policies are specified, by, for example, specifying which one or which multiples in any particular order should be executed. Authorization 216 is described in more detail below in conjunction with FIG. 5 .
MediationPolicy 206 has a one-to-many relationship with an Audit 220 , each of which defines a particular method of auditing an inbound request from a service customer. It should be noted that a service request may be audited even though the service customer has been identified, as explained above in conjunction with element 210 , and the identity has not been authenticated, as described above in conjunction with element 214 and/or the request has not been authorized, as explained above in conjunction with element 216 . Element 220 may specify a new audit policy or reference a policy that has been previously declared. An audit policy contains an AuditMethod attribute (not shown) that indicates one or more audit mechanisms. Examples of possible audit mechanisms include, but are not limited to, creating a log record or file, creating one or more database records and sending one or more electronic messages, or “emails,” to an appropriate party. A PolicyCombiningAlgorithm element 221 provides a mechanism for combining multiple audit policies in the event two or more policies are specified, by, for example, specifying which one or which multiples in any particular order should be executed.
MediationPolicy 206 has a one-to-many relationship with an Mapping 224 , each of which defines a particular method of mapping one identity to another, for example when a particular service customer is know by different names by different service providers. For example, mapping 224 may be employed when a service consumer and a service provider use different user registries or in similar circumstances. Element 224 may specify a new mapping policy or reference a policy that has been previously declared. A mapping policy contains a MappingMethod attribute (not shown) that indicates one or more mapping mechanisms. Examples of possible mapping mechanisms include, but are not limited to, one-to-one mapping, mapping based upon a LDAP lookup and rule-based mapping. A MappingType element 225 specifies how a particular mapping is performed. Mapping 224 is described in more detail below in conjunction with FIG. 6 .
MediationPolicy 206 has a one-to-many relationship with a Transformation 228 , each of which defines a particular method of transforming a service request. A transformation of a service request is an additional operation that is executed on the service request before the request is transmitted to a service provider. Element 228 may specify a new transformation policy or reference a policy that has been previously declared. A transformation policy contains a TransformationMethod attribute (not shown) that indicates one or more transformation mechanisms. Examples of possible transformation mechanisms include, but are not limited to, a custom extensible style sheet language transformation (XSLT), a WS-Security token replacement, TIVOLI® federated identity manager (TFIM) token replacement, generating a LTPA token and generating a SAML assertion. A PolicyCombiningAlgorithm element 229 provides a mechanism for combining multiple transformation policies in the event two or more policies are specified, by, for example, specifying which one or which multiples in any particular order should be executed.
By providing structures such as 210 , 214 , 216 , 220 , 220 , 224 and 228 , the claimed subject matter is able to provide a platform-independent, or “enhanced,” ESB. The standardization of interfaces provides means for individual mediation policies to be replaced without requiring changes to either applications, such as app_ 1 144 ( FIG. 1 ) and app_ 2 ( FIG. 1 ) and servers, such as ser_ 1 ( FIG. 1 ) and ser_ 2 ( FIG. 1 ). In this manner, changes in a security policy do not need to be implemented in each application that uses EESB 126 . In addition, authorization and identity mapping may be removed from information applications and token service and specialized security handlers can be easily transferred from one ESB platform to another even if security policies are implanted in the ESBs.
FIG. 4 is a block diagram of a model for an identification policy 240 (see 152 , FIG. 2 and 210 , FIG. 3 ) of mediation language 202 of FIG. 3 employed by the EESB 126 of FIGS. 1 and 2 . Like FIG. 3 , Identification policy 240 includes MediationPolicySet 204 , MediationPolicy 206 , MediationPolicyID 207 , identification 210 and PolicyCombiningAlgorithm 211 . Both MediationPolicySet 204 and Identification 210 are illustrated as having a one-to-many relationship with an IdentificationPolicy 242 . Each instantiation of IdentificationPolicy 242 represents a particular method for performing an identification function, as described above in conjunction with FIG. 3 . As explained above, functions may include, but are not limited to, a WS-Security username token, a client IP address, a LTPA mechanism, a SAML token, a custom XPath expression applied to the request, a Kerberos AP-REQ from SPNEGO token and a HTTP Authentication header.
A specific method is identified by an instantiation of element 242 with an IdentificationMethod attribute 244 . The specific instantiation of element 242 is associated with an IdentificationPolicyID 246 , which is a key that uniquely identifies the specific instantiation of the policy. Attributes 244 and 246 are two examples of specific properties associated with element 242 . Attributes 244 and 246 , as well as any other attributes are stored in an Attribute 250 , which includes an AttributeID 252 to uniquely identify the corresponding attribute. Each attribute 250 is also associated with one or more attribute values 254 . In general, an attribute is a generic element used in the different elements to provide policy designers with a mechanism for defining additional policy configurations. For example, an attribute in used in an AuthenticationPolicy element (not shown) may be a host name of a particular LDAP server. Identification 210 may also be associated with multiple IdentificationPolicyRef 248 , each of which provides a reference to a particular instantiation of IdentificationPolicy 242 .
FIG. 5 is a block diagram of a model for an authorization policy 260 (see 154 , FIG. 2 and 216 , FIG. 3 ) of the mediation language 202 of FIG. 3 employed by the EESB 126 of FIGS. 1 and 2 . Like FIG. 3 , Identification policy 260 includes MediationPolicySet 204 , MediationPolicy 206 , MediationPolicyID 207 , Authorization 216 and PolicyCombiningAlgorithm 217 . Both MediationPolicySet 204 and Authorization 216 are illustrated as having a one-to-many relationship with an AuthorizationPolicy 262 . Each instantiation of AuthorizationPolicy 262 represents a particular method for performing an authorization function as described above in conjunction with FIG. 3 , which as explained above may include, but are not limited to, using an XACML policy decision point, checking for membership in a LDAP group, generating a SAML authorization query and calling an AZN API.
A specific method is identified by an instantiation of element 262 with an AuthorizationMethod attribute (not shown). The specific instantiation of element 262 is associated with an AuthorizationPolicyID 263 , which is key that uniquely identifies the specific instantiation. An attribute 266 is a specific property associated with element 262 . AuthorizationMethod attribute and AuthorizationPolicyID, as well as any other attributes are stored in an Attribute 266 , which includes an AttributeID 268 to uniquely identify the corresponding attribute. Each attribute 266 is also associated with one or more attribute values 270 . Authorization 216 may also be associated with multiple AuthorizationPolicyRef 264 , each of which provides a reference to a particular instantiation of AuthorizationPolicy 262 .
FIG. 6 is a block diagram of a model for a mapping policy 280 (see 155 , FIG. 2 and 224 , FIG. 3 ) of the mediation language 202 of FIG. 3 employed by the EESB 126 of FIGS. 1 and 2 . Mapping 224 is typically employed in situations when a service consumer and a service provider use different user registries or in other similar circumstances.
Like FIG. 3 , Identification policy 260 includes MediationPolicy 206 , MediationPolicyID 207 , Mapping 224 and MappingType 225 . Each instantiation of Mapping 224 represents a particular method for performing a mapping function as described above in conjunction with FIG. 3 , which as explained above may include, but are not limited to, one-to-one mapping, mapping based upon a LDAP lookup and rule-based mapping. Each instantiation of mapping 224 is associated with an InboundIdentity element 282 that is used in conjunction with one-to-one mapping. Element 282 indicates the target identity for the current mapping policy. Each instantiation of mapping 224 is also associated with an OutboundIdentity element 284 that is used in conjunction with one-to-one mapping. Element 284 indicates the destination identity for the current mapping policy. Like the other elements of mediation policy model 202 , mapping 224 may include additional attributes 286 , each of which is associated with an attributeID 288 , which uniquely identifies a particular attribute 286 . Each attribute 286 is also associated with one or more AttributeValues 290 , which stores the relevant data associated with each attribute 286 .
FIG. 7 is a flowchart of Setup EESB process 300 that is an example of one aspect of the claimed subject matter. In this example, logic associated with process 300 is stored on data storage and executed on a processor associated with server 125 ( FIG. 1 ) as part of EESB 126 ( FIGS. 1 and 2 ). Process 300 starts in a “Begin Setup EESB” block 302 and proceeds immediately to a “Retrieve PolicySet” block 304 . During block 304 , process 300 retrieves a MediationPolicySet 204 that is, as explained above in conjunction with FIGS. 3-5 , a data structure that defines a platform-independent identity mediation policy, such as MediationPolicy 206 ( FIGS. 3-6 ). As explained above in conjunction with FIG. 3 , a MediationPolicySet 204 is typically defined by an authorized administrator.
During a “Parse PolicySet” block 306 , process 300 analyzes MediationPolicy 206 , which was retrieved during block 204 . In general, process 300 identifies individual MediationPolicy 206 policy components such as components 210 , 214 , 216 , 220 , 224 and 228 ( FIG. 3 ). During a “Get Next Policy” block 308 begins to process each component, or module, identified during block 306 . For example, the first time through block 206 , process 300 may process Identification 210 ( FIGS. 3 and 4 ). During an “Analyze Policy” block 310 , process 300 examines, in this example, the values stored in Identification 210 to ascertain how a specific identification policy is identified.
During a “Policy Reference?” block 312 , process 300 determines whether or not Identification 210 lists a specific identification policy, such as IdentificationPolicy 242 ( FIG. 4 ) directly or provides a reference to a particular identification policy via IdentificationPolicyRef 248 ( FIG. 4 ). If process 300 determines that a reference to a policy is employed, control proceeds to a “Retrieve Referenced Policy” block 314 during which the specific policy is identified.
During a “Correlate Policy” block 316 the specific policy being processed is correlated with a particular module such as components 210 , 214 , 216 , 220 , 224 and 228 ( FIG. 3 ). During a “Load Policy” block 318 , process 300 loads into memory for processing by EESB 126 the specific policy that was identified either during block 312 or block 314 into the component 210 , 214 , 216 , 220 , 224 and 228 identified during block 316 . During “Another Policy” block 320 , process 300 determines whether there is another type of policy that needs to be loaded into EESB 126 . For example, once an identification policy has been loaded, an authentication policy such as Authentication 214 ( FIG. 3 ), Authorization 216 ( FIGS. 3 and 5 ), Audit 220 ( FIG. 3 ), Mapping 224 ( FIG. 3 ) and Transformation ( FIG. 3 ) may be processed and loaded. If process 300 determines that one or more policies remain to be loaded, control returns to Get Policy block 308 , the next unprocessed policy is retrieved and processing continues as described above.
Finally, if process 300 determines during block 320 that all relevant policies have been loaded into EESB 126 , control proceeds to an “End Setup EESB” block 329 in which process 300 is complete.
FIG. 8 is a flowchart of an Operate EESB process 240 that is an example of one processing aspect of the claimed subject matter. Like process 300 , in this example, logic associated with process 340 is stored on data storage and executed on a processor associated with server 125 ( FIG. 1 ) as part of EESB 126 ( FIGS. 1 and 2 ). Process 340 is initiated during Setup EESB process 300 (see 320 , FIG. 7 ). Process 340 starts in a “Begin Operate EESB” block 342 and proceeds immediately to a “Wait for Request” block 344 .
During block 344 , process 340 waits for a mediation request. For example app_ 1 114 ( FIG. 1 ) may make a request of a service provided by ser_ 136 ( FIG. 1 ). During a “Parse Request” block 346 , process 340 determines the nature of the request by identifying both the requestor and the requested service. During an “Identify Identity” block 348 (see 210 , FIGS. 3 and 4 ), process 340 determines the identity of the party making the request (see 282 , FIG. 6 ) and, during a “Mapping Required?” block 350 (see 224 , FIGS. 3 and 6 ), process 340 determines whether or not the identity associated, in this example with app_ 1 114 is the same as an identity expected or authorized to access serv_ 1 136 (see 284 , FIG. 6 ). Typically, information necessary for this determination is stored in configuration data stored in conjunction with EESB 126 (see 151 , FIG. 2 ).
If process 340 determines that a mapping is required, control proceeds to a “Map Identity” block 352 (see 224 , FIGS. 3 and 6 ). During block 352 , process 340 associates the identity identified during block 348 (see 282 , FIG. 6 ) with an appropriate identity associated with the service identified during block 346 (see 284 , FIG. 6 ). Once mapping is complete during block 353 or, if during block 350 process 340 has determined that mapping is not required, control proceeds to an “Authenticate identities” block 354 (see 214 , FIG. 3 ). During block 354 , process 340 determines that the parties identified during blocks 348 and 352 are the actual identities, i.e. a “spoofing” detection is made. Those with skill in the computing and communication arts should be familiar with various techniques to perform this task.
During an “Authorize Request” block 356 , process 340 verifies that the identities identified during blocks 348 and 352 and authenticated during block 354 are authorized to access the services of the requested service (see 216 , FIGS. 3 and 5 ). During a “Transform. Required?” block 358 , process 340 determines whether or not the request received during block 344 requires any additional processing (see 228 , FIG. 3 ). If so, control proceeds to a “Perform Transform” block 360 during which the additional processing is executed. Once any transformation processing is complete during block 360 or, if during block 358 process 340 has determined that not such processing is required, control proceeds to an “Establish Connection” block 362 during which the connection between, in this example app_ 1 114 and ser_ 1 136 is established and ser_ 1 136 may process the request of app_ 1 114 .
Once a connection has been established, process 340 proceeds to a “Log Process” block 364 during which the processing is logged, if process 340 is so configured (see 220 , FIG. 3 ). It should be noted that if any processing fails to executed properly, for example identities cannot be identified during block 348 , identities cannot be authenticated during block 354 or a request cannot be authorized during block 356 , an asynchronous (“async.”) interrupt 366 is generated and control is passed to Log Process block 364 and that information is logged. Once information is logged during block 364 , process 340 returns to Wait for Request block 344 and processing continues as described above.
Finally, process 340 is halted by means of an asynchronous interrupt 368 , which passes control to an “End Operate EESB” block 369 in which process 340 is complete. Interrupt 268 is typically generated when the OS, browser, application, etc. of which process 340 is a part is itself halted. During nominal operation, process 340 continuously loops through the blocks 344 , 346 , 248 , 350 , 352 , 354 , 356 , 358 , 360 , 362 and 364 , processing mediation requests as they are received.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and 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.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. | Provided are techniques for providing security in a computing system with identity mediation policies that are enterprise service bus (EBS) independent. A mediator component performs service-level operation such as message brokering, identity mediation, and transformation to enhance interoperability among service consumers and service providers. A mediator component may also delegate identity related operations to a token service of handler. Identity mediation may include such operations as identity determination, or “identification,” authentication, authorization, identity transformation and security audit. | 6 |
BACKGROUND AND SUMMARY OF THE INVENTION
Utility service trucks, particularly those used for telephones, carry quantities of wire which are coiled on spools and payed out in the lengths required by mechanical payoff equipment. The spools generally carry a large quantity of wire and are heavy; and the payoff equipment is also heavy.
In order to reduce the size and operating cost of service trucks, this invention provides means for supplying the necessary wire from smaller and inexpensive spools from which the wire can be payed out without removing the spool from its shipping carton and without having any payout equipment, such as has to be used with heavy spools.
This invention provides a spool which can be constructed from corrugated paperboard by a novel arrangement of parts; and the spool is shipped in a special carton, which can also be made of corrugated paperboard, and which has provision for convenient payout of the wire without removing the spool from the carton.
Features of the invention include the special construction of the spool and carton; provision for holding the end of the wire for convenient handling and, at the same time, adequate sealing against tampering before the carton is opened for use; low friction of the spool as it rotates in the carton during payout of wire; convenient rewinding of wire on the spool of any excess wire payed out from the carton; and inspection openings through which the amount of wire remaining on the spool as the spool rotates while the wire is paying out, can be determined.
Other objects, features and advantages of the invention will be pointed out as the description proceeds.
BRIEF DESCRIPTION OF DRAWING
In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:
FIG. 1 is a side view, partly broken away and in section, of a carton and wire spool made in accordance with this invention;
FIG. 2 is a fragmentary sectional view taken on the line 2--2 of FIG. 1;
FIG. 3 is a greatly reduced scale view showing the blank from which the carton of FIG. 1 is made by folding the various panels along predetermined fold lines;
FIG. 4 is a reduced scale view showing one of the flanges of the spool of FIGS. 1 and 2 before the spool is assembled;
FIG. 5 is a fragmentary plan view of the top of the carton shown in FIG. 1 and illustrating the openings through which wire is withdrawn from the carton;
FIG. 6 is a sectional view on the line 6--6 of FIG. 5 but showing the top opening closed by a knockout;
FIG. 7 is a fragmentary, reduced scale view of the core of the spool before the spool is assembled; and
FIG. 8 is a view similar to FIG. 7 but showing a modified construction for the core.
DESCRIPTION OF PREFERRED EMBODIMENT
A container or box 10 includes a front wall 12 and a back wall 14 connected to one another by side panels 15 and 16. The box is preferably made from a single blank, as shown in FIG. 3.
The left-hand edge of the side panel 15 is secured to the right-hand edge of the front wall 12 by a flap 17 and suitable adhesive. There are end panels 21, 22, 23 and 24 attached to the walls 12 and 14 and panels 15 and 16, respectively, along fold lines designated by the dotted line 26 in FIG. 3. There are similar end panels at the other end of the box indicated by the same reference characters but with a prime appended. These panels at the bottom of the box are similar to those at the top, except that certain openings are provided in the top panels for removal of wire from the box.
The flap 17 is secured to the panel 15, and the box is folded flat along fold lines 30 and 32. When the box is to be set up, preparatory to receiving a spool of wire, the folded blank is opened up so that the front and back walls 12 and 14 extend at right angles to the panels 15 and 16; and the end panels are then folded inward with the panels at the top and bottom of the box overlapping others at the same end of the box to produce the container shown in FIG. 1.
The bottom panels 21', 22', 23' and 24' are secured together with adhesive over areas sufficient to provide a strong and permanent bottom for the box; this bottom being indicated by the reference character 34 in FIG. 1.
The upper panels 21, 22, 23, and 24 are not secured together until after the box is filled. A spool 36, having flanges 38 and a core 40 connecting the flanges is inserted into the box 10 with the upper panels 21-24 extending upward. The spool 36 is of a size which fits loosely within the box 10 so that the spool is free to rotate in the box with no substantial pressure against the sides of the box, except such pressure as is exerted by the weight of the spool and its contents against an underlying side of the box; the particular side depending upon which way the box is oriented when being used to supply wire.
A coil of wire 44 is wound on the core 40 between the flanges 38 in the conventional manner. The outer end portion of the wire 44, which is designated in the drawing by the reference character 46, is led out through an opening 48 before the panel 24 is folded down into the position which it will occupy when the box is closed. The end portion 46 is then led through an opening 50 as the panel 26 is folded down into closed position. The portion 46 of the wire is then bent horizontally and the end of the wire inserted back into the box 10 through an opening 52 in the panel 22 and through an opening 54 in the panel 24, as shown in FIG. 6.
The upper panel 21 is then folded down to complete the closing of the box, and the various panels forming the top of the box are secured together with adhesive, or otherwise, with sufficient strength to provide a top structure which is an integral unit of the box.
The upper panel 22 is cut away between the openings 50 and 52 to provide a clearance 56 for the end portion of the wire, as also shown in FIG. 6. This clearance 56 is made with a wider part between the openings 50 and 52 so that a workman can insert his thumb and forefinger into the clearance 56, on opposite sides of the wire, to pull the wire upward and bring the end of the wire out of the openings 52 and 54 when more wire is to be pulled out of the box.
The upper panel 21 has a knockout 60 where the panel is cut part way through or cut enough to weaken it so that the knockout 60 can be removed to expose the openings 50 and 52 and the other openings in alignment with these openings 50 and 52. The knockout 60 seals the box during shipment and as long as the knockout is in place, anyone receiving the box in shipment is assured that the wire has not been tampered with or any of it withdrawn from the carton prior to delivery of the carton at its ultimate destination.
The spool has two flanges; the nearer flange in FIG. 1 being designated by the reference character 38 and the distant flange by the reference character 38'. Both of the flanges are of similar construction, and each one has a center opening 64 which is large enough to enable a workman to insert his hand into the interior of the spool and grip the circumferential edge of the opening 64 so as to rotate the flange manually, as necessary, and the spool must be rotated in order to wind the wire back into the box. In order to provide access to the edge of the opening 64, there is a knockout 66 in each of the front and back walls 12 and 14. Removal of a knockout 66 leaves an opening 66a, as shown for the front wall 12 in FIG. 1. The opening 66a is substantially larger in diameter than the opening 64 of the flange so as to provide exposure of an outside surface of the flange which can be gripped by a workman to rotate the spool when winding wire back on the spool.
There is another knockout 70 in the front wall 12, and when this knockout 70 is removed it leaves an inspection opening 70a which has a radial extent equal to the radial thickness of the wire 44 on the spool 36 when the spool is full of wire. There are openings 72 at angularly spaced locations around the flange 38. These openings 72 are preferably of the same size as the opening 70a, and they are located in positions that are in alignment with the opening 70a whenever one of the openings 72 passes under the opening 70a as the spool 36 rotates in the box. The openings 72 extend completely through the flange 38 and thus expose the wire 44 to view, so that anyone using the wire from the spool 36 can see how much wire is left on the spool as each of the successive openings 72 passes under the inspection opening 70a.
The spool 36, which fits loosely in the box 10, rotates in the box and has relative movement with respect to any inside surface of the box in which it contacts from time to time. In order to reduce friction and to make it easier to withdraw wire from the spool, means are preferably provided for reducing the friction between the spool and the surfaces of the box. This is done economically by lining the box with wax paper 76 or by coating the blank from which the box is made with wax applied to the surfaces which will constitute the inside of the box when the blank is folded to complete the box.
Each of the flanges 38 is made with angularly located slots 80. The core 40 is formed with a continuous panel 82 which is long enough to form the circumference of the core. There are projections 84 extending from opposite edges of the panel 82, and these projections 84 are of a size to insert into the slots 80. The projections 84 are then bent inwardly toward the axis of the spool 36, and end portions 86 of the projections 84 are tucked into other slots 90, which are radially spaced from the slots 80. This construction is best shown in FIG. 2. To facilitate the neat bending and tucking in of the projections 84, there are weakened lines 92 formed in each projection at the time that the core blank is manufactured by die-cutting it from a panel of corrugated paperboard when the spool is made of such material.
FIG. 8 shows a construction of a core blank which is similar to FIG. 7 but made with projections 84' which are spaced further apart, so that there is a projection 84' for every other slot 84. The projections 84' on one side of a panel 82' are in staggered relation with similar projections 84' on the other end of the core. This reduces the labor involved in connecting the flanges to the core when assembling a spool, but at some sacrifice in the strength of the spool.
The spool and its shipping container can be made of other material than that described above for the preferrred embodiment, and other changes and modifications can be made, and some features can be used in different combinations without departing from the invention as defined in the claims. | This specification discloses simplified wire payout apparatus for paying out wire directly from a box in which the wire is shipped, thus eliminating the necessity of providing mechanical payout equipment such as has been required on utility service trucks. For light-weight and low cost, a corrugated paperboard carton is used as a shipping container; and provision is made for paying out the wire without removing a spool, on which the wire is wound, from the box. The spool is preferably also made of corrugated paperboard. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation under 35 U.S.C. sec. 120 of the earlier filing date of U.S. patent application Ser. No. 09/031,245, filed Feb. 26, 1998, U.S. Pat. No. 6,102,846 inventors Patton et al., for A SYSTEM AND METHOD OF MANAGING A PSYCHOLOGICAL STATE OF AN INDIVIDUAL USING IMAGES.
FIELD OF THE INVENTION
This invention relates in general to the management of a physiological and/or psychological state of an individual and more particularly to the management of the physiological and/or psychological state of an individual through the use of images which have been customized for use by the individual and which can be part of a self-help process.
BACKGROUND OF THE INVENTION
The physical, emotional and mental well-being of an individual can contribute greatly to the quality of life of that individual. In our hyperactive, hyperkinetic world, stress results in numerous physical reactions, such as, headache, muscle tension, dizziness or sleeplessness, weight gain, chronic coughing, nervous ticks, stomach upset and shortness of breath. Job stress alone is estimated to cost American business $300,000,000,000 annually. Stress is the response of the body and/or mind to a demand placed upon it. Stress can be caused by major events in one's life, such as, death of a loved one, marital breakup, personal injury or sickness, and job loss. Stress can also result from our day-to-day hectic style of living, where one attempts to excel simultaneously at being a super employee, a super parent, a super spouse, and a super citizen. Unless chronic stress is controlled, one puts oneself at risk for a host of serious problems, such as, heart disease, stroke, migraines, muscle and nerve disorders.
The typical path to obtain relief from stress is to visit one's doctor. Stress conditions result in up to 70% of all doctor's visits. Typically, drugs are prescribed to relieve stress. One stress reducing medication alone accounts for $6,000,000 per day in sales. Thus, alternative approaches to traditional medicine have become increasingly popular. Resort to Eastern religions, transcendental meditation, and biofeedback techniques have been proposed to empower the individual to reduce stress without the potential deleterious effects of powerful and expensive prescription drugs or invasive surgery.
It has been proposed to use images for the purpose of optimizing one's physiological and psychological state. There are several reasons for this.
(1) It has been shown that one can measure a reliable physiological response for images that differ in valence and arousal. It has been demonstrated that images rated differently with respect to perceived activation and pleasantness elicited physiological responses of different magnitude. Thus, magnitude of the skin conductance response correlated with perceived arousal level produced by pictorial stimuli. At the same time heart rate acceleration during first 4 to 5 seconds of image presentation reflected “valence” or degree of perceived pleasantness of an image. Other physiological parameters that reflect an individual's physiological reactions to images have also been demonstrated. These results imply that, for an individual viewer, images can potentially be classified based on one's physiological reactions in terms of emotional arousal.
(2) Imagery is known to be able to change a person's state. Paintings, movies, pictures are constantly affecting our mood and performance level. Power of visualization and affective content determine effective use of imagery in therapeutic sessions. Experimental research has also shown that presentation of images of similar content may cause significant shifts in physiological reactions.
(3) Digital imaging technology provides an almost instant access to image databases through the internet. Moreover, the potentially unlimited degree of digital manipulation makes images very attractive means of interaction and communication. Images can be easily transformed to alter or enhance people's preferences, i.e., for hue, saturation, depth, aesthetic feelings, etc. Image transformation by itself can provide biofeedback information to the user to facilitate learning how to control one's physiological and emotional state, e.g., stress.
Following are several proposals to use images as a means of changing one's state that have not proven to be entirely successful.
U.S. Pat. No. 5,465,729, issued Nov. 14, 1995, inventors Bittman et al. and U.S. Pat. No. 5,343,871, issued Sep. 6, 1994, inventors Bittman et al., disclose the use of measurements of electrophysiological quantities to control a presentation to a subject of a series of prestored audio-visual sequences.
U.S. Pat. No. 3,855,998, issued Dec. 24, 1974, inventor Hidalgo-Briceno discloses an entertainment device that includes sensing means connected to the user for sensing galvanic skin response and brain theta waves. According to a given measured state of a user the device provides a given type of predetermined audio-visual stimulation to the user for a timed interval to hold one in or move one toward a desired state. At the end of the interval, the user's state is again measured and a further timed audio-visual response according to the measured state is presented to the user.
U.S. Pat. No. 5,596,994, issued Jan. 28, 1997, inventor Bro, discloses an automated and interactive positive motivation system that allows a health care professional to produce and send a series of motivational messages to a client to change or reinforce a specific behavioral pattern.
U.S. Pat. No. 5,304,112, issued Apr. 19, 1994, inventors Mrklas et al., discloses an integrated stress reduction system which detects the stress level of a subject and displays a light pattern reflecting the relationship between the subject's stress level and a target level. The system also provides relaxing visual, audio, tactile, environmental, and other effects to aid the subject in reducing one's stress level to the target level.
U.S. Pat. No. 4,632,126, issued Dec. 30, 1986, inventor Aguilar, discloses a biofeedback technique which permits simultaneous, preferably redundant, visual and auditory presentation on a color TV of any intrinsically motivating stimuli together with continuous information pertaining to the physiological parameter to be controlled. As the subject changes a certain physiological parameter, the image and sound become clearer if the change occurs in the desired direction.
U.S. Pat. No. 5,253,168, issued Oct. 12, 1993, inventor Berg, discloses a system for allowing an individual to express one's self in a creative manner by using biofeedback signals to direct imaging and audio devices.
U.S. Pat. No. 5,676,138, issued Oct. 14, 1997, inventor Zawalinski, discloses a multimedia computerized system for detecting emotional responses of human beings and changes thereof over time.
U.S. Pat. No. 5,047,930, issued Sep. 10, 1991, inventors Marten, et al., discloses methods of analyzing physiological signals from a subject and analyzing them using pattern recognition techniques to determine a particular sleep state of the subject. Use of any associated feedbacks is not disclosed.
The following papers discuss various emotional responses and physiological responses of subjects to viewing images.
Affective judgement and psychophysiological response: dimensional covariation in the evaluation of pictorial stimuli; by: Greenwald, Cook and Lang; Journal of Pyschophysiology 3 (1989), pages 51-64.
Remembering Pictures: Pleasure and Arousal in Memory, by: Bradley, Greenwald, Petry and Lang; Journal of Experimental Psychology, Learning Memory and Cognition; 1992, Vol. 18, No. 2, pages 379-390.
Looking at Pictures: Affective, facial, visceral, and behavioral reactions; by: Lang, Greenwald, Bradley, and Hamm, Psychophysiology, 30 (1993), pages 261-273.
Picture media and emotion: Effects of a sustained affective context; by: Bradley, Cuthbert, and Lang, Psychophysiology, 33 (1996), pages 662-670.
Emotional arousal and activation of the visual cortex: An fMRI analysis; by: Lang, Bradley, Fitzsimmons, Cuthbert, Scott, Bradley, Moulder, and Nangia; Psychophysiology, 25 (1998), pages 199-210.
The techniques disclosed in the above references have the following disadvantages.
1. There is no development of a personal image profile of an individual so as to provide for customized images which are specifically tailored for the individual so as to move the individual to a desired physiological and/or psychological state. This is important since an image which is restful for some may be stressful for others.
2. The images or other stimuli for inducing change in state in an individual are preselected by someone other than the user. The selection is often based on the effect of the images on a large number of subjects rather than being personalized for the individual.
3. Where measurement of physiological parameters are used as part of the state change technique, the measurement devices are often large and not very portable and therefore not conducive for use at work, at home or during travel.
SUMMARY OF THE INVENTION
According to the present invention there is provided a solution to the problems referred to above.
According to a feature of the present invention there is provided a method of managing a physiological or psychological state of an individual using images comprising: determining an individual's direction or preference for a state management session; based on the determination, deciding whether a current set of images selected through a personal image profile session, will achieve the desired management effect; if the current set are deemed satisfactory, presenting the set of images to the individual to achieve management of the individual's state.
ADVANTAGEOUS EFFECT OF THE INVENTION
The present invention has the following advantages.
1. An individual is profiled to provide customized images which are specifically tailored for the individual to move the individual to a desired physiological and/or psychological state.
2. The images or other stimuli for inducing change in the state of an individual arc not preselected by someone other than the user, but rather by the user.
3. A portable device is used to measure physiological parameters to predict an individual's state. The portable device is conducive for use at work, at home, during travel, or during exercise.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are flow diagrams useful in explaining the present invention.
FIGS. 3-5 are diagrammatic views illustrating several embodiments of a portable physiological sensor monitor.
FIGS. 6-11 are graphical views useful in explaining certain aspects of the present invention.
FIGS. 12 and 13 are diagrammatic views useful in explaining other aspects of the present invention.
FIG. 14 is a block diagram of the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
General Discussion
In general, as shown in FIG. 14, the system 100 of the present invention includes several interrelated components that can be used to help one to manage one's physiological and or psychological state. These components will be described in greater detail later but, in general, include one or more of the following:
1. Portable Biosensor Device ( 102 )
A portable biometric device that is worn or carried by a user and which senses and records physiological parameters on a continuous basis.
2. Master Set of Images ( 104 )/Therapeutic Image Classification System ( 106 )
A set of images presented to a user to determine the user's physiological and cognitive image preferences. The images are classified according to a therapeutic image classification system.
3. Biometric Analyzer ( 108 )
A biometric analyzer which extracts the physiological activation state of user from one or more measured physiological parameters.
4. Cognitive Analyzer ( 110 )
A cognitive analyzer which extracts cognitive state from cognitive responses to images.
5. Personal Image Profiler ( 112 )
A personal profiler which combines the physiological and cognitive measures obtained from the biometric analyzer and cognitive analyzer to generate an individual's personal image profile for a given state response.
6. Personal Image Classifier ( 114 )
A personal image classifier which, based on an image bank having images which have been classified using a therapeutic image classification system, and on the personal image profile, selects activating and deactivating images to create a personal image set.
7. Visualization System ( 116 )
A visualization system which presents the personal image set to a person with the goal to help manage, modify or maintain current physiological and psychological state.
The components of system 100 can take different forms, depending on the application. For example, the portable biosensor device 102 measures one or more physiological parameters of an individual. The measurements can be recorded in the device and appropriate resident software used to analyze the state of the individual. Alternatively, the measured physiological parameters can be transmitted over a wireless channel to a server where they are recorded and analyzed. A warning signal can then be transmitted back to the portable device to warn the user of the need to manage one's state.
Components 104 - 112 can reside as software in a computer that is located with the individual, at a health care professional's office, or the like. The images selected by component 114 can reside in local or remote database(s) that can be communicated with over standard communication links (public telephone, cell phone, internet/world wide web, intranet, etc.). The visualization system 116 , includes a display which can form part of a computer, a television, a handheld device, such as a PDA, game, or entertainment device, a slide projector, a cell phone. The visualization system can include devices such as a CD player, a DVD player, a VCR, etc. The system can include devices for other sensory feedback, such as, auditory, olfactory, tactile (heat, vibratory), etc. The applications of the present system are set out in greater detail below.
The interrelated use of these components is set forth in FIGS. 1 and 2. As shown in FIG. 1, the process 10 is started (bubble 12 ). It is determined (diamond 14 ) if this is a first time use. If the answer is no, the process of FIG. 2 is carried out (A). If the answer is yes, the process continues (box 16 ) where an appropriate visualization system presents a master set of images to the user. If the Portable Biosensor Device has been used, it is docked to the visualization device to give a record of physiological parameters of the user measured over a period of time (box 18 ).
The biometric analyzer(box 20 ) and cognitive analyzer measures (box 22 ) physiological and cognitive states from the user during presentation of the master set of images.
The personal profiler (box 24 ) generates the user's personal image profile based on the combined physiological and cognitive measures.
Based on the personal image profile and a therapeutic image classification system (box 26 ) for images in a therapeutic image data bank (databases) (box 28 ), activating and deactivating images are selected from the image data base(s) to create a personal image set (box 30 ).
The user then decides (diamond 32 ) if he or she wants to have a session. If no, the session ends (bubble 34 ). If yes, the process continues to A in FIG. 2 .
Once a personal image set has been established, the user can start a session (A). The Biometric Analyzer (box 40 ) and Cognitive Analyzer (box 42 ) can be used to determine a user's desired direction/preference for a session (e.g., relaxation, optimal performance, excitation (box 44 ).
Based on the inputs, the Personal Profiler (box 46 ) decides if the current Personal Image set will work or if an updated, Personal Image profile is needed. The Personal Profiler can also receive inputs from a Portable Biosensor Device (box 48 ) and from a user's physiological, cognitive and image use history from a secured data base (box 50 ).
If the current image set is determined to be OK (diamond 52 ), the visualization device presents images to the user according to one's preferences. The duration and/or sequence of presentation, the type of transformation of the images are performed based on users physiology. (box 54 ) Input from a “Coach” (box 56 ) may also be provided. The “Coach” monitors physiological responses of the user and provides feedback in form of visual feedback, verbal reinforcement, verbal suggestions and new techniques.
The user then decides to continue or not (diamond 58 ). If yes, the process is returned to A. If no, the process is ended (bubble 60 ). If the current image set is determined to be not OK (diamond 52 ), the process is operated in a learning mode (box 62 ) where other images from an image bank are shown on a trial and error basis. The user may wish to create an updated profile (diamond 64 ). If “yes”, the process continues to “B” in FIG. 1 . If “no”, the process is ended (bubble 60 ).
Following are more detailed descriptions of each of the components described above.
PORTABLE BIOSENSOR DEVICE
In medical compliance (taking medicine regularly, exercising regularly etc), it may be beneficial for a user to have a system that tracks, reminds, and rewards the user. On the same token, for an excellent individualized biofeedback based wellness management program, The Portable Biosensor Device tracks and reminds the user to perform wellness management as needed.
The Portable Biosensor Device is a portable device having one or more sensors that record physiological parameters of an individual wearing the device. Different individuals react differently to different sensors under different situations. Through individual sensor response profile (as explained in personal profiler section) we will be able to produce a personalized device. The device contains multiple sensors to measure temperature, heart rate variability (HRV) (measured either from ECG, photoplethysmographic methods or continuous blood pressure), SCR (skin conductance response), EEG, EMG, eye saccades etc.
The device will accommodate different sensor sets based on the embodiment. For example as shown in FIG. 5, a wrist type device 70 with sensors 72 and computer 74 can record temperature, HRV through continuous blood pressure monitoring, and SCR. A head band type of device 80 with sensors, 82 connected to computer 84 (on waist band-not shown) shown in FIG. 3 can measure EEG and EMG. As shown in FIG. 4, an earphone type of device 90 with sensors 92 connected to computer 94 (on waistband not shown) could measure temperature, heart rate variability through photoplethysmographic methods, and SCR.
The portable biometric device is microprocessor based and records the user's physiology throughout the day, especially between sessions. Using digital signal processing on the sensor data, it will analyze (or analyze using the Profiler) and make predictions on the individual's state. Predictions will be made either using phasic physiological responses such as change in heart rate or SCR, or using sophisticated techniques such as Independent Component Analysis or pattern recognition. For example, increased heart rate and SCR could indicate activation or excitement, however, more sophisticated analysis could differentiate between excitement to startle and excitement in defense. According to Cacioppo et al (1996), though both the startle response and the defense response are associated with increased heart rate and SCR, they exhibit different patterns of activation. In the case of the startle response, the heart rate acceleration peaks and returns to near normal levels within two seconds, whereas in the case of the defense response, the heart acceleration does not begin to rise for several seconds and peaks much later.
Moreover, if the user chooses to know, the feedback to the individual user can be provided through either vibration (tactile or kinesthetic), auditory, or visual means. The data recorded in the device can either be stored on the device or transmitted to an individual server via wireless communication channel.
BIOMETRIC ANALYZER
The Biometric Analyzer plots, on a two/multi dimensional plot, physiological reactivity of each individual for different situations such as
Baseline
Different type of stressors (active coping task such as mental arithmetic, passive task such as situation narration)
Calmed state
Energized state
It should be noted that
1. The reactivity to specific images can also be plotted on this plot, and mapping is performed to cluster images in various groups.
2. Various sensor measures, such as EEG, EMG, HRU, eye saccades, hand temperatures, etc., can be simultaneously used.
3. Clustering of images into various groups can be done using techniques such as Euclidean distance, ratio of distances etc.
4. Plotting can be done using different techniques such as principal component analysis, or independent component analysis, wavelet, neural networks, time series, and other signal processing techniques.
One such technique (CLMOD) using principal component analysis, mapping images between a baseline and arithmetic stressor, using eye saccades, heart rate and EMG measures, and using a ratio of distance of the image to the stress to the distance of the image to the baseline is explained in more detail below. In general, this technique determines which images are physiologically “activating” or “deactivating”. The technique can be implemented as follows.
A subject is seated in a comfortable chair before a display monitor. Sensors are attached to the subject to record biological information, such as, finger temperature, muscle tension, and heart rate. The physical responses are recorded while the subject views images presented on the monitor and while doing mildly stressful activities. The data is collected several (e.g., 256) times a second, while at rest, while viewing the images, and while cognitively rating them, as well as while talking about oneself and during a mental arithmetic task and during rest periods after each stress test.
A subset of the physiological measures from these time periods is selected for use. The data is prepared using Fourier analysis for some physiological measures and histograms for other physiological measures.
The data from the baseline, stress and rest time periods are broken into multiple, non-overlapping 15 second segments, and then a histogram or a spectrum computed from a Fourier analysis is used for each time segment. The histograms and/or spectra for each time segment are then fed into a Principal Component Analysis (PCA). In a preferred embodiment of this method, either Canonical Discriminant Analysis or Neural Networks might replace PCA. The result of the PCA analysis is that, (1) a set of weights called “loadings” is created, and (2) a set of “scores” or summary values, for each time segment is created. The data from the image periods are prepared using Fourier analysis and histograms, and the loadings are applied to these image period Fourier spectra and histograms. The result is a set of “scores” for each image period.
The image period scores are then compared to the scores for the baseline, stress and rest time segments. An image score that is “close” to the centroid of the baseline scores indicates an image that is “deactivating”. An image that is close to the centroid of the stress scores indicates an image that is “activating”. An image score that is not “close” to either the centroid of the baseline scores or the centroid of the stress scores indicates an image that is neutral. What is meant by “close” can be determined in several ways. One technique is to determine the Euclidian distance from each centroid and then create the ratio of the distance to baseline centroid divided by distance to stress centroid. The difference between the image score and the blank period score can also be used instead of the image score itself.
Following is a more detailed description of the CLMOD Analysis.
Description of Biometric Analysis
1. Take physiology for baseline, discard first 2 minutes and last 2 minutes and chop remainder into non-overlapping 15 second segments. Call the data in these segments B 1 through B 24 . (An example of heart rate and EMG data for two consecutive 15 second segments are shown in FIGS. 6 and 7 respectively)
2. Take physiology for Stress 1 , chop into non-overlapping 15 second segments. Call the data in these segments S 1 1 through S 1 12 .
3. Take physiology for Stress 2 , chop into non-overlapping 15 second segments. Call the data in these segments S 2 1 through S 2 12 .
4. Take physiology for Rest 1 , chop into non-overlapping 15 second segments. Call the data in these segments R 1 1 through R 1 12 .
5. Take physiology for Rest 2 , chop into non-overlapping 15 second segments. Call the data in these segments R 2 1 through R 2 12 .
6. For each data segment B 1 -B 24 , S 1 1 -S 1 12 , S 2 1 -S 2 12 , R 1 1 -R 1 12 , R 2 1 -R 2 12 , perform the following calculations:
(a) Take the heart rate data and compute the periodogram (Fast Fourier Transform). Interpolate this periodogram so that the height of the periodogram is available at pre-specified intervals. An example of two periodograms that corresponds to the data shown in FIG. 7 is shown in FIG. 8 .
(b) Take the EMG data and compute the histogram, using pre-specified bin widths. Store the percent of data in each bin. An example of EMG histograms corresponding to the data shown in FIG. 6 is shown in FIG. 9 .
7. Combine the heart rate interpolated periodogram, EMG histogram percents and Eye saccade histogram percents into one data set, where the rows are the different data segments and the columns are the histogram bins and/or periodogram heights. The histograms need to be aligned (and padded with zeros if necessary) so that the data in each column represents the same bin.
8. Scale this data set as follows: Subtract from each data point the mean of the column it is in. Each column then has a mean of zero. Each of the columns related to the heart rate interpolated periodogram has a variance (not standard deviation) of 1/n H , where n H is the number of pre-specified frequencies to use in the heart rate FFT. Each of the columns related to the EMG histograms has a variance of 1/n EMG , where N EMG is the number of such columns. Each of the columns related to the Eye Saccades histograms has a variance of 1/n EYE , where n EYE is the number of such columns. This scaling ensures that heart rate, EMG and Eye saccades contribute equally to the next analysis. An example of the result of this step is shown in FIG. 10, where the scaling has been performed not just for the two 15 second intervals shown on the plots, but across the entire set of 15-second segments as explained above.
9. Perform Principal Component Analysis (PCA) on this data, retaining the first 5 dimensions. (The number 5 was chosen arbitrarily, and it can vary from subject to subject.) Store the PCA scores in five dimensions.
10. For each image period, perform the analyses described above in 6a, 6b, 6c 7, and 8. In step 8, use the mean calculated in step 8, not a new mean calculated on the Image period data. Take care to align the columns of the histograms to match the way the columns are aligned for the baseline, stress and rest data. Call these data segments I 1 -I 82 . Apply the PCA vectors from step 9 to the I 1 -I 82 data segments to compute PCA scores in five dimensions. Append these scores with the PCA vectors computed in step 9.
11. Plot the PCA scores in scatterplots, with different symbols for the different groups. An example of such a scatterplot is shown in FIG. 11 .
12. Compute the distance in nd dimensions (where n d is some pre-specified number) of each image location in PCA space from the centroid (mean PCA score) of each of the baseline, stress and rest period data. The metric for activation and/or de-activation is any one or more of the following. A threshold or cutoff needs to be set to pick which images are activating or de-activating or neutral.
a). Distance from Baseline (or calmed state) Centroid
b). Distance from Stress I (or activated state) Centroid
c). Parks Ratio, which is (distance from baseline centroid)/(distance from stress 1 centroid)
Modified Biometric Analysis
10′. In addition to step 10 above, for each blank period perform steps 6a, 6b, 6c, 7, and 8. Call these segments BL 1 -BL 82 .
11′. In addition to step 11 above, apply the PCA vectors to data segments BL 1 -BL 82 .
11 . 5′ Subtract the PCA scores for each image segment from the PCA scores from each blank period. Call these data Δ 1 -Δ 82 .
12′. Plot the PCA scores for Δ 1 -Δ 82 instead of the PCA scores for the image periods I 1 -I 82 . Also, as in the previous step 12, plot the PCA scores for the baseline, stress and rest periods. The subtracted PCA scores are interpreted as showing the direction and amount of movement due to the change from blank to image period. Thus, we are really plotting the end of a vector whose other end is at the origin. An image that has vector length close to zero shows little physiological movement and can be interpreted as neutral.
The following steps are used to determine activation and deactivation:
(a) Determine the angle for each image Δ 1 -Δ 82 . This can be done in n d dimensions (where n d is some pre-specified number).
(b) Determine the set of angles for the baseline period data segments. If an angle for Δ 1 -Δ 82 is contained in the range of angles for the baseline period and the length of the vector for each of Δ 1 -Δ 82 is above some threshold, then we say that this image is de-activating. Vectors that point in the baseline direction but are less than this threshold value are considered neutral. (A modification would be to add ±k to the range of angles to allow for some uncertainty is our ability to locate the baseline cluster; k might be 10 degrees, we need to experiment to find a good value for k.)
(c) Determine the set of angles for the stress 1 period data segments. If an angle for Δ 1 -Δ 82 is contained in the range of angles for the stress 1 period and the length of the vector for each of Δ 1 -Δ 82 is above some threshold, then we say that this image is activating. Vectors that point in the stress 1 direction but are less than this threshold value are considered neutral. (A modification would be to add ±k to the range of angles to allow for some uncertainty is our ability to locate the baseline cluster; k might be 10 degrees, we need to experiment to find a good value for k.)
(d) Vectors that do not point towards either Stress 1 or Baseline are considered “other”. These might be pointing towards other stress modes, or other calming modes, or they may be neutral. We cannot decide from this analysis.
Therapeutic Image Classification Scheme
This scheme is a set of a scene and image related features or attributes (or characteristics) that are relevant to potential therapeutic effect in a broad sense which includes emotional, sensational, cognitive, arousing, esthetical and any other possible impacts registered psychologically or psychophysiologically, that an image may produce while a person viewing the picture. By therapeutic effect, hence, we understand the ability of an image or series of images, video clips, or other visual material alone or in combinations with other modaltics purposely presented to improve a person's process, (quality, productivity or effectiveness) performance, state or attitude under consideration which otherwise would become a limiting or negative factor in the person's activities. These aspects are related to the person self, his/her interaction with the outside world (information, specific tasks, etc.) and inter-personal interaction and communication.
The above features are related to an appearance, content, composition, semantics, intentionally sought impression, uncertainty in interpretation, emotional load and probability of association with a particular emotion, etc. and ideally should represent all dimensions that may influence a holistic impression an image (or other type of visual and other stimulations mentioned above) produces.
The attributes can be rated in terms of importance and profoundness for each image.
THERAPEUTIC IMAGING CLASSIFICATION SCHEME
S UBJECT M ATTER
Anything that appears to be a primary subject or part of the primary subject is categorized.
Defined categories include:
L ANDSCAPES
Natural or imaginary scenery as seen in a broad view, consisting of one or more of the following elements which dominate a large percentage of and/or being central to the image.
Mountain
Water
Sun
Vegetation
Sand
Snow
Urban
P EOPLE —A CTIVITY
Static
The subject either does not exhibit movement or intentionally poses.
Active
Captured at the moment of active motion.
P EOPLE —E XPRESSION
No Expression
Happy Faces
A happy facial expression of a person that is the subject matter.
Unhappy Faces
Unhappy facial expression of a person is a subject matter
P EOPLE
Children
People who appear to be 18 years old or younger.
Family
The primary subject includes a group of two or more people, regardless of agc, exhibiting strong bonds of familiarity and/or intimacy.
A NIMALS
Pets
A domestic or tamed animal kept for pleasure or companionship (e.g., dogs, cats, horses, fish, birds, and hamsters).
Pleasant
A picture of a pet doesn't or is not intended to generate an unpleasant feeling or look.
Unpleasant
A picture of a pet does or is intended to generate an unpleasant feeling or look.
Wild
An undomesticated or untamed animal in its original natural state, or confined to a zoo or animal show (e.g., lions, elephants, seals, giraffes, zebras, and bears).
Pleasant
A picture of a wild animal doesn't or is not intended to generate an unpleasant feeling or look.
Unpleasant
A picture of a wild animal does or is intended to generate an unpleasant feeling or look.
A BSTRACT
An image which achieves its effect by grouping shapes and colors in satisfying patterns rather than by the recognizable representation of physical reality.
O THER
Other can be used when neither of the defined categories of the subject matter can be applied.
L IGHTING
Sun
Predominantly distinct shadows are noted. This also includes indoor photos where the subject is directly illuminated by sun through a window. Shadows must be present. If the subject is shading itself, the primary type of light is SUN.
Sunset/Morning/Evening
This type of light is typified by long shadows.
Hazy/cloudy/Overcast
This type of light produces soft shadows (if any) and the light direction is often obscured, flat, and low contrast.
Shade
This light is relatively diminished or partial due to cover or shelter from the sun.
This also includes Indoor pictures where the subject is illuminated by diffuse daylight from a window.
Mix Sun and Shade
This type of light includes spotty sunlight or a mixture of sun and shade.
Flash
A brief, intense burst of light from a flashbulb or an electronic flash unit, usually used where the lighting on the scene is inadequate for picture-taking.
C OLOR /D OMINANT H UE
Determined when one or two colors are seeing to be the prominent and global descriptors for a particular picture. If three colors are seen than we define that the picture does not have a dominant hue.
Red
Yellow/Orange
Green
Blue
Purple/Magenta
Brown
White/Grey
No Dominant hue (if more than 2)
D IRECTION OF LIGHT
Front
Light shining on the side of the subject facing the camera.
Hints: Sunlight conditions where the shadow falls behind the subject. Flash pictures from point and shoot cameras.
Side
Light striking the subject from the side relative to the position of the camera; produces shadows and highlights to create modeling on the subject.
Hints: Sunlight conditions where long shadow falls on the side of the subject.
Back
Light coming from behind the subject, toward the camera lens, so that the subject stands out vividly against the background. Sometimes produces a silhouette effect.
Hints: TV's, Sunsets, and “Lights are Subject” are backlit. In backlit scenes, the shadow may fall in front of the subject, and appears to come towards the photographer.
Zenith
Light coming from directly above the subject.
Hints: High noon lighting. Deep shadows in the eye sockets and below the chin.
Diffuse
Lighting that is low or moderate in contrast, such as an overcast day.
Hints: Diffuse produces no shadows or just barely visible shadows, such as found on a cloudy, hazy day. Some mixed sun and shade pictures are also diffuse when the direction of light can not be determined.
Multidirectional
This indicates lighting coming from different directions, such as some stage lighting conditions or in a home where a window is on one side of the subject and a lamp on the other. Multiple shadows should be present if the lighting is from different directions and a flash was used.
T RAVEL /O FFSET D IRECTION OF GAZE MOTION/TRAVEL
A subjective feeling (introspection) of moving one's eyes primarily along a particular trajectory or in a certain direction while viewing a picture.
Centered
Right to left/Left to right
Up to down/down to up
Multidirectional
Distance
Low 0-9 feet
Medium 9-20
High more than 20
COGNITIVE ANALYZER
Images from the master image set are presented to the subject to identify his or cognitive response profile in terms of which image attributes and images alter an individual emotional response and arousal level. The individual is asked to rank an image on one or more of three cognitive scales. Preferably, a measure of the cognitive preference computed from the scores along three cognitive scales is used, i.e., Valence, Arousal and Connectedness.
Definitions of Scales
Each scale is a two-ended scale with an anchor in the center marked 0. These three scales are described below:
Detached is a feeling of not being able to personally connect or relate to the object or situation depicted in the image. Attached is a feeling of personnel connection to the object or situation depicted in the image.
Unhappy is a feeling of sadness or disconnect that occurs when you view the object or situation depicted in the image. Happy is a feeling of contentment or satisfaction that occurs within you when you view the object or situation depicted in the image.
Calm is a feeling of tranquillity and silence that occurs within you when you view the object or situation depicted in the image. Excited is a physical state of being in which your feelings and emotions have become aroused that occurs when you view the object or situation being depicted in the image.
The user is given enough time to provide their reaction to each of the scales. He/she is instructed to follow their first impression. To facilitate the emergence of feelings that could be associated with an image, the users are encouraged to imagine themselves being “in an image” or part of an image that they are viewing. However, the users are requested not to force themselves to feel an emotion. Certain images may be neutral and elicit no emotions. Reactions will be different for each individual.
All three scales can be used individually to provide a measure of valence, arousal and connectedness. Each of them constitutes a valuable information source related to the person's reaction and can be independently used to assess them. The three scales can be combined to compute the measure of the cognitive preference.
Current implementation of the cognitive preference computation takes into account the absolute value of the total response, the variance of the ratings along each scale within an individual to normalize the response and logical rules that intend to increase the internal validity of the measure.
The method and procedure are as follows:
Step 1
Every image, I, is subjectively rated along each of the axes Attached/Detached (C), Calm/Excited (A) and Happy/Unhappy (V) such that it has three values C (I), A(I), and V (I) associated with it. R(I i )=(C 2 (I i )+A(I)+V 2 (I i ))
Step 2
Normalize scale values
C(I i )=C(I i )*R(I i )/max i R(I)
A(I i )=A(I i )*R(I i )/max i R(I)
CI i )=V(I i )*R(I i )/max i R(I)
Where i=1 . . . , 82
Step 3.
Compute the standard deviation per scale: S ( V ) = ∑ i ( V ( I i ) - mean ( V ( I i ) ) ) 2 n - 1 S ( A ) = ∑ i ( A ( I i ) - mean ( A ( I i ) ) ) 2 n - 1 S ( C ) = ∑ i ( C ( I i ) - mean ( C ( I i ) ) ) 2 n - 1
Step 4.
Normalize every scale value from each image using appropriate standard deviations
C(I i )=C(I i )/S(C)
A(I i )=A(I i )/S C)
V(I i )=V(I i )/S(C)
Step 5.
If C(I i )<=1, then C(I i ) is Neutral along the C scale
If A(I i )<=1, then A(I i ) is Neutral along the A scale
If V(I i )<=1, then V(I i ) is Neutral along the V scale Step 6.
If image is Neutral along the V scale and is neutral along any other one scale it is overall neutral.
Step 7.
Paradoxical images
If image I is not neutral and
(V(I)>0)&(C(I)<0)& (A(I)>0 or
(V(I)<0)&(C(I)>0)& (A(I)<0
then
I is considered to be a paradoxical one.
Step 8.
Cognitively preferred.
If image I is not neutral and not paradoxical
I is cognitive preferred
<=>
(V(I)>0)
with the score equals V(I)
Step 9
Cognitively not preferred
If image I is not neutral and not paradoxical
I is cognitively not preferred
<=>
(V(I)<0) with the score equals V(I)
THE PERSONAL IMAGE PROFILER
Each individual user has their own characteristics; preferences of images, music, coaching etc., in other words, each person has a unique personal profile. This profile is thought to allow us to be better able to select images or other stimuli for the user. To be able to select images requires sophisticated methods not only to record but to analyze and understand the trait and state data of a person. The personal profiler does exactly that.
1. It gathers data from the portable biometric device (on going physiological data), biometric analyzer (Physiological data for different situations and images), and the cognitive analyzer (data on demographics, psychographics, cognitive preferences for images).
The preferred method is as follows:
Step 1. Selecting Activating/Deactivating images:
a) Use BIOMETRIC analyzer method (e.g. CLMOD) to identify clearly activating or deactivating images. If the image is close to the baseline cluster then the image will be considered deactivating, or if the image is closer to the stressor cluster, then the image will be considered deactivating.
b) Only in situations, where we do not have enough images to fill the four categories 1-4, we will use Calm/Exciting scale along with the BIOMETRIC analyzer method to pick activating/deactivating images.
c) Ranking rule: The images will be ranked based on following criteria a. Ratio of distance of the image to stressor and baseline
Step 2. Dividing the Activating/Deactivating images into C+ and C− categories:
a) Use data from the scales in COGNITIVE ANALYZER to categorize images as preferred or not preferred. We do not use Calm/Excited scale.
b) For PARADOXICAL images make decisions using rules specified in the COGNITIVE ANALYZER:
c) Ranking rule: The Euclidean distance on Unhappy/Happy and Detached/Attached scales will be used to rank the images in the C+ and C− categories. The top ranking images will be used if the total number of images in each category is more than 10.
Step 3. Augment images by reducing threshold if necessary
a) If the number of images in any of the four categories (picked based on Biometric analyzer method, and cognitive scales) is less than 4 then we will try to
Increase the number of images by lowering the threshold in BIOMETRIC model
Increase the number of images by lowering the threshold in the cognitive model to 0.55 SD (currently the threshold is 0.67 SD)
b) If the number of images in any category are more than 4 but less than 10, we will try to maximize the number of total images using upto 5 similar for each image. The minimum number of images in each session would be 15 and maximum will be 20.
c) If the number of images from any category are more than 10, we will pick the top 10. The ranking will be based on ranking rules specified in steps 1 and 2. The total number of images will be 30 and we will pick upto 2 similar for each image.
Step 4. Handle images that show very high physiology but neutral cognitive
a) We reduce the threshold of the two cognitive scales to to 0.55 SD to see if that puts the image in consideration into C+ or C−.
b) If not, we assign the image into both the C+ and C− category
Step 5. Handle images that show very high cognitive but neutral physiology
a) We reduce the threshold in BIOMETRIC ANALYZER model to see if that puts the image in consideration into activating or deactivating.
b) If not, we assign the image into both the activating and deactivating category
2. Based on this data, it creates an individualized profile. The profiler uses generic models and population data to make predictions and personalization of coaching, stimuli, and even the user interface of the image presentation device.
3. Using digital signal processing on the sensor data, it analyzes and makes predictions on the individual's state. Predictions will be made either using phasic physiological responses, such as change in heart rate or SCR, or using sophisticated techniques, such as individual component analysis or pattern recognition. For example, increased heart rate and SCR could indicate activation or excitement, however more sophisticated analysis could differentiate between startle and defense. According to Cacioppo et al (1996), although startle response and defense response are both associated with increased heart rate and increased SCR, they exhibit different patterns of activation. In the case of startle, the heart rate acceleration peaks and returns to near normal levels within two seconds, whereas in the case of defense response the heart acceleration does not begin to rise for several seconds and peaks much later.
4. All the data is recorded in the profiler for future reference and use. The Personal Profiler also keeps records of data collected from subsequent biofeedback sessions.
5. Using statistical methods, the profiler tries to understand what worked and what did not.
PERSONAL IMAGE CLASSIFIER
The Personal Profiler collects the data from the BIOMETRIC analyzer and COGNITIVE analyzer and classifies the images into
1) Cognitively preferred/Physiological activating
2) Cognitively preferred/Physiologically deactivating
3) Cognitively not preferred/Physiological activating
4) Cognitively not preferred/Physiological deactivating
Images selected using cognitive analyzer and biometric analyzer are treated as a collection of images that describes an individual image profile. After classifying the master images into these four categories, the Personal Image Classifier, builds these image sets by picking images from the Therapeutic Image Bank using similarity metrics method. Therapeutic image bank uses the therapeutic image classification scheme to accurately mark each individual image with its inherent characteristics. The goal is to find images similar to each image in a profile to create sets of images that share similar characteristics with respect to individual's reactions. Therapeutic image bank may contain personal pictures as well as stock photographs. The ultimate goal is to be able to classify images automatically using this scheme. The procedure currently used is:
1. All the images in the image bank are tagged with a 0 (for a particular feature not existent in the image) or 1 (for a particular feature not existent in the image), as shown in tables below. The columns represent the features from the classification scheme.
PEOPLE/
LANDSCAPE
ACT
EXPRESSION
PEOPLE
#
ABS
OTH
Mt
Wt
Vg
Sun
Snd
Snw
Urb
Sta
Act
Non
Hap
Unh
Chd
Fam
1
0
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
2
1
1
. . .
1
1
N
1
ANIMALS
Pleasant
Unplesnt
LIGHTING
LIGHT DIRECTION
#
Pet
Wld
Pet
Wld
Sun
Snst
Haz
Othr
Ind
Fmt
Side
Bac
Znith
Dfus
1
0
0
0
0
0
0
0
1
0
0
0
1
0
0
2
1
. . .
1
1
N
1
1
COLOR — DOMINANT HUE
DISTANCE
TRAVEL/OFFSET
#
Red
Y/Or
Gm
Blu
Prp
Bm
Gry
Blk
Non
Low
Medm
Hig
Ctr
U/D
L/R
Mult
1
0
1
0
0
0
0
0
0
0
0
1
0
0
1
0
0
2
1
1
1
1
. . .
1
1
1
1
N
1
1
1
2. To build a particular image cluster (say calming images), copy the classification record of all calming images from the master set for the particular individual into a buffer.
3. Examine each image from this buffer and using similarity matrix techniques such as Minkowski method, find similar images from the image bank. A similarity metrics can be established as the sum of all agreements between image features established in the step 1 and weighted by the feature importance (for an individual). Thus the Minkowski metric with various exponents can be used to determine the similarity. We used the value of the exponent equal to 1. Weighting coefficients are determined experimentally using a screening or specifically designed testing procedure and are considered as the order of an individual's feature importance related to the therapeutic effect.
4. Copy the new formed cluster into a new database for the individual with other metadata such as user identification, data and time of clustering, physiological reactivity to each image, cognitive reactions to each image.
This metadata will eventually be used in the personal profiler to evaluate the effectiveness of images in subsequent sessions.
VISUALIZATION SYSTEM
This is the main component that the user works with images to relax, energize, or do biofeedback training. This could be implemented on a computer, TV with set top box, handheld device such as PDA's, CyberFrames, or gaming devices . The purpose of the Visualization System is to allow participants to maintain their mind-body wellness using proper personalized coaching based on trends in physiology and cognitive feeling. Uniqueness of Visualization System is:
Personalized image selection and training that understands the users trends in activation or deactivation.
Coaching that continues even after the session and allows one to do a retrospective analysis of physiology changes between sessions.
Intelligent image understanding and personal preference data allows the coach to guide the user to certain parts of image or to a totally different image as needed.
The overall mind-body wellness is achieved by presenting a series of stimuli (e.g. images) that are selected based on personal cognitive and physiological preferences in an order that is “natural” for the individual, along with personalized coaching and relevant feedback. The process includes the following steps:
(1) To initiate a session, the user docks the buddy into a docking station (if the image presenter is implemented on a TV or a desktop computer) or into a docking port if it is a handheld device.
(2) If this is the first session, the system needs some profiling data to understand what images are suitable for this individual. The profiling is done using a Master Image Presenter and Personal Profiler. The system records demographics and psychographics data for the user.
(3) A master set of images (A Kodak set designed based specifically for different cultures) are presented to the user and their cognitive feelings and physiological reactivity are recorded for each image.
(4) As described in the Personal Profiler (including biometric analyzer and cognitive analyzer), the cognitive preference is recorded using the three scales, whereas physiological reactivity is recorded for the most sensitive measures. The physiological sensitivity for each individual is recorded using different situations such as baseline, different stress activities, calming, and energizing activities.
(5) As described in the Personal Image Classifier, the cognitive and physiological feelings are combined using certain rules and used to categorize the master set images into preferred calming, preferred activating, and neutral images. The Personal Image Classifier builds a unique set of images for the individual, based on similar images selected from the therapeutic image classification scheme and the therapeutic image data bank. Each image is coded with metadata, such as the features of the image, its rank on physiological reactivity for the subject, its rank on the cognitive scaling, etc. This metadata is used eventually to decide when and how long this particular image will be presented. At this stage either cognitive, physiology or both can be used for categorization. Different product embodiments can have different implementations.
(6) In subsequent sessions, the Image Presentation Device uses the unique image set in presentation.
(7) Establish the identification of the participant before allowing access to the system either through password authentication or physiology measures signatures. Understand from the user what they would like to do today and try to assess the correlation between how they feel cognitively and what their physiology is suggesting.
(8) Provide general instructions on how to breathe as the user views different images. This coaching will be a combination of diaphragmatic breathing, autogenics, guided imagery, and meditation thoughts. The Visualization System incorporates appropriate coaching (male/female voice, autogenics/no autogenics, some mechanism of trust-building, diaphragmatic breathing etc), different types of feedback, personalized order of presentation, personalized schemes of fading, and appropriate timing.
(9) Feedback can be either direct feedback through either digital readouts of physiology and/or various graphical means such as abstract bars, trend charts, slider graphs, colored bar graphs, etc., or indirect feedback through changes in the image parameters such as hue, saturation, sharpness.
(10) The system will also provide continual reinforcement based on the trend and temporal changes in the user's physiology state.
(11) Through out the session, the system tracks the physiology trends on the sensors that are most sensitive to the user. The intelligent coaching agent has certain generic rules built in. It also has a learning system that understands and records the user's sensitivities to different physiology measures as well as their responsiveness, and according modifies the instructions. The coaching agent bases its instruction both on the physiological changes as well as the feelings that are recorded through cognitive scales.
(12) The user interacts with the coach through natural interactions such as speech, direct point and click, and physiology changes. The coaching agent has a “persona” that is customized for each individual. Different persona of the coach could be varied on the gender, ages, instruction styles, mannerisms, personality types that a particular user likes. Certain amount of anthropomorphism is also provided in the coaching agent to facilitate one-to-one connection between the coach and the user.
(13) The coach also has intelligent image understanding and provides certain cues on contents of the images. These cues are stressed if the coach has prior knowledge about the user's preference.
(14) Apart from the individually selected mix of images, the Visualization System also provides individual image categories (sunset, beaches, rain, landscapes, family, children etc).
(15) It also provides both individualized and generic transforming images. Transforming images can include images that transform existing content such as an image showing sunset, or a flower blooming as well as adding new content e.g. a waterfall scene with a rainbow added to the scene if the user achieves a certain stage in the calming process.
(16) Throughout the session the Personal Profiler records the efficiency of the images. The profiler keeps record of what worked and what did not. (This is thought at the current moment to be available in the advanced implementation).
(17) The influence of the Visualization System on the user's behavior does not end at the end of the session. At the end of the session, the coaching system records how the user feels and will tell the user that they should carry the feelings and learning from this session to the real world. The user physiology will be monitored by the portable biosensor device between the sessions. The coach can then query, understand and advise the user based on the physiology data that is collected between sessions.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST
10 process
12 60 process steps
70 wrist type device
72 sensors
74 computer
80 head band type device
82 sensors
84 computer
90 earphone type device
92 sensors
94 computer
100 system
102 portable biosensor device
104 master set of images
106 therapeutic image classification system
108 biometric analyzer
110 cognitive analyzer
112 personal image profiler
114 personal image classifier
116 visualization system | A method of managing a physiological or psychological state of an individual using images comprising: determining an individual's direction or preference for a state management session; based on the determination, deciding whether a current set of images selected through a personal image profile session, will achieve the desired management effect; if the current set are deemed satisfactory, presenting the set of images to the individual to achieve management of the individual's state. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to the art of vehicular non-contact anti-pinch systems for preventing a closure panel such as a window or sliding door from pinching an object such as a person's hand as the closure panel moves into its closed position.
BACKGROUND OF THE INVENTION
[0002] Proximity sensors are widely used in the automotive industry to automate the control of power accessories. For instance, proximity sensors are often used in power window controllers to detect the presence of obstructions in the window frame when a window panel is being directed to the closed position. Such sensors can also be used to detect the presence of obstructions in other types of automotive closures such as sunroofs, side doors, sliding doors, lift gates, and deck lids.
[0003] A variety of capacitor-based proximity sensors are known in the art. For example, U.S. Pat. No. 6,377,009 discloses a system for preventing the pinching or trapping of a foreign object by a closing panel (such as a window) through the use of a sensing electrode or plate. This electrode is a metal strip or wire which is embedded in a plastic or rubber molding strip placed behind a piece of fascia or other trim part. The metal strip or wire and the chassis of the vehicle collectively form the two plates of a sensing capacitor. A foreign object placed between these two electrodes changes the dielectric constant and thus varies the amount of charge stored by the sensing capacitor over a given period of time. The charge stored by the sensor capacitor is transferred to a reference capacitor in order to detect the presence of a foreign object. Similar capacitive sensing applications are known from DE 4036465A, DE 4416803A, DE 3513051A1, DE 4004353A.
[0004] There are two major problems that have to be overcome for capacitive anti-pinch systems to work well in practice.
[0005] The first problem relates to the large background capacitance presented by the relatively enormous area of the sheet metal and plastic surrounding the closure aperture. For instance, in a power sliding door application, there is a large gap in between the sliding door and the vehicle frame. The presence of a small element such as a child's finger may not make an appreciable difference to the overall capacitance, and thus may be rejected as noise. Alternatively, if a relatively high sensitivity is employed to detect such a small change, too many false positives may occur (it being understood that no system is perfect and that there many some acceptable degree of false positives).
[0006] The second problem relates to the variable capacitance presented by changing humidity or water levels. The existence of high humidity or water will increase the dielectric constant of the system and thus will either mask the presence of a small object such as a child's finger or cause too many false positives.
[0007] In order to deal with such issues, it is known to utilize capacitive shielding and a differential capacitance sensing system which reduces the effect of parasitic capacitance arising from the sheet metal. It is also known to map the background capacitance as the closure panels opens and use that map as a reference as the closure panel closes to detect a differential. And it is known to vary the sensitivity of the system as the closure panel nears its final closing position. See, for instance, Applicant's PCT Publication Nos. WO 2002/101929, WO 2002/012699, WO 2003/038220, and WO 2005/059285.
[0008] However, the presence of water can still cause too many false positives, particularly when the sensor itself is wet. And since a human being's dielectric constant is similar to the dielectric constant of water, there could be a situation when the presence of water on the sensor causes too many false positives.
SUMMARY OF THE INVENTION
[0009] According to a first aspect of the invention, a method is provided for preventing a closure panel from pinching an obstruction extending through an aperture of a motor vehicle having a motor to drive the closure panel between an open position and a closed position. The method includes: measuring a capacitance of a field extending through the aperture using a capacitive sensor as the motor drives the closure panel between the open and closed positions; identifying a position of the motor using a position sensor as the motor drives the closure panel between the open and closed positions; correlating the measured capacitance to the position identified to create closing data; comparing the closing data to a reference map to create a compare value; and detecting an object in a path of the closure panel as the closure panel moves toward the closed position when the compare value exceeds a threshold value dependent on the relative wetness of the sensor.
[0010] The threshold value is preferably adjusted for each closure of the panel by comparing the capacitance of the sensor at predetermined closure panel positions against a calibration wetness profile to determine the relative wetness of the capacitive sensor and determine a threshold adjustment value based on the relative wetness of the capacitive sensor.
[0011] The reference map is preferably generated each time the closure panel moves from the closed position to the open position by: measuring a capacitance of the field extending through the aperture using the capacitive sensor as the motor drives the closure panel, identifying a position of the motor using the position sensor as the motor drives the closure panel, and correlating the measured capacitance to the position identified.
[0012] Preferably, the method also includes measuring a time period that the compare value exceeds the threshold value to distinguish the detection of the object from noise.
[0013] The capacitance may be measured indirectly by cyclically charging the capacitance sensor and transferring charge therefrom to a reference capacitor, and either measuring the voltage of the reference capacitor after a predetermined number of charging cycles or measuring the number of cycles required to charge the reference capacitor to a predetermined voltage.
[0014] The capacitive sensor preferably includes a non-conductive casing, a first at least partially conductive body embedded in the casing, a second at least partially conductive body embedded in the casing, an air gap between the first and second at least partially conductive bodies, a first conductive strip electrode embedded in the first dielectric body, and a second conductive strip electrode embedded in the second dielectric body, wherein the casing, the at least partially conductive bodies and the strip electrodes are sufficiently flexible to allow the first and second at least partially conductive bodies to contact one another upon the application of a predetermined pinch force.
[0015] Utilizing such a capacitive sensor, the method preferably includes further detecting an object in the path of the closure panel as it moves toward the closed position when the electrical resistance between the first and second electrodes falls below a predetermined resistance.
[0016] The method may also include further detecting an object in the path of the closure panel as it moves toward the closed position by monitoring the position sensor to for lack of change therein or by monitoring the current drawn by the motor.
[0017] Once an object is detected, the closure panel is prevented from continuing to move toward the closed position and is preferably reversed.
[0018] A controller and control circuitry is enabled to carry out the foregoing functions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing and other aspects of the invention will be better understood from the following detailed description of preferred embodiments of the invention in conjunction with the drawings thereof, wherein:
[0020] FIG. 1 is a diagram of an automotive door having an obstruction sensor mounted thereto;
[0021] FIG. 2 is a cut-away diagram of a portion of an elongate obstruction sensor;
[0022] FIG. 3 is a system block diagram of an anti-pinch system;
[0023] FIG. 4 is a schematic graph illustrating a method of detecting an object based on capacitive sensing;
[0024] FIG. 5 is a graph of the capacitance of a sensor over varying wetness conditions; and
[0025] FIG. 6 is a graph of an adjustment factor based on the degree of sensor wetness.
DETAILED DESCRIPTION OF THE INVENTION
[0026] This application incorporates the following publications by reference in their entirety:
PCT Publication No. WO 2002/101929 PCT Publication No. WO 2002/012699 PCT Publication No. WO 2003/038220 PCT Publication No. WO 2005/059285
[0031] FIG. 1 illustrates a typical automotive door 12 that is comprised of sheet metal and includes an aperture 14 , structured as a window frame 40 , which may be closed by a window pane or glass panel 16 . The glass panel 16 is raised or lowered by a window regulator (not shown) which includes an electric motor as the motive driving source, as well known in the art per se. The motor is controlled in part by a non-contact obstruction sensor or anti-pinch assembly 10 , the particulars of which are described in greater detail below. The anti-pinch assembly 10 includes an elongate sensor 18 that prevents the glass panel 16 from pinching or crushing a foreign object such a finger (not shown) that may be extending through the aperture 14 when the panel nears its closed position. It will be appreciated by those skilled in the art that the anti-pinch assembly 10 can be applied to any motorized or automated closure panel structure that moves between an open position and a closed position. For example, a non-exhaustive list of closure panels includes window panes, sliding doors, lift gates, sunroofs and the like. For applications such as window panes or sun roofs, the elongate sensor 18 may be mounted on the frame of the vehicle, and for applications such as powered sliding doors the elongate sensor 18 may be mounted on the closure panel itself, .e.g., at the leading edge of the sliding door. For ease of description, the remainder of this disclosure will focus on the windowpane and window frame combination, it being understood that the apparatus and methods described herein can be applied to other types of vehicular closure systems.
[0032] Referring additionally to FIG. 2 , the elongate sensor 18 includes a non-conductive casing 20 mounted near or on the upper part of window frame 40 as seen in FIG. 1 . Two conductive strip electrodes 24 a and 24 b such as wires are preferably disposed in the casing 20 . Electrode 24 a is embedded in a first partially conductive body 26 a and electrode 24 b is embedded in a second partially conductive body 26 b . These partially conductive bodies 26 a, 26 b may be formed from a carbonized or electrically conductive rubber, and the surfaces 28 a, 28 b of these bodies preferably have a greater concentration of carbon or conductive material and thus able to carry a greater current than the inner part of the body. An air gap 22 separates the two partially conductive bodies 26 a, 26 b, and an adhesive tape 30 provides a means for fastening the casing 20 to the window frame 40 .
[0033] The casing 20 is preferably formed as an extruded, oblong, elastomeric trim piece with co-extruded upper and lower partially conductive bodies 26 a, 26 b, and the electrodes 24 a and 24 b are molded directly into the bodies 26 a, 26 b. The trim piece can be part of the window water sealing system, i.e., form part of a seal, or can form part of the decorative fascia of the vehicle.
[0034] The air gap 22 electrically insulates the two electrodes 24 a, 24 b so electrical charge can be stored therebetween in the manner of a conventional capacitor. However, unlike a conventional capacitor, the elongate sensor 18 is flexible enough to enable the surfaces 28 a, 28 b of the first and second partially conductive bodies 26 a, 26 b to touch one another when pinched (i.e., as a result of a pinch condition), but not so flexible as to cause contact with one another as the closure panel ordinarily closes. The flexibility of the elongate sensor 18 can be controlled by its cross sectional configuration, including controlling the thickness of the casing walls and the thickness of the partially conductive bodies 26 a, 26 b.
[0035] Referring additionally to FIG. 3 , the anti-pinch assembly 10 includes a controller 50 connected to the two electrodes 24 a, 24 b that measures the resistance R between the electrodes. The resistance R will be very high when the partially conductive bodies 26 a, 26 b are separated from each other by the air gap 22 , and will substantially reduce in magnitude if a portion of the partially conductive bodies 26 a , 26 b contact one another. Thus, the elongate sensor 18 and anti-pinch assembly 10 is capable of functioning as a fail-safe contact pinch strip.
[0036] In addition to functioning as a contact pinch strip, the elongate sensor 18 also functions as a non-contact capacitive sensor, and is utilized by the controller 50 to measure a capacitance of a field extending through the aperture 14 . In the illustrated embodiment, electrode 24 b functions as a shielding electrode since it is closer to the sheet metal whereby the electric field sensed by electrode 24 a will be more readily influenced by the closer electrode 24 b than the vehicle sheet metal. For best signal quality it is most preferable if the door is electrically isolated from the remainder of the vehicle. A powered sliding door, for instance, may be isolated through the use of non-conductive rollers.
[0037] The capacitance of the elongate sensor 18 is measured as follows: The electrodes 24 a and 24 b are preferably charged by controller 50 to the same potential using a pre-determined pulse train. For each cycle the controller 50 transfers charge accumulated between the electrodes 24 a and 24 b to a larger reference capacitor 52 , and records an electrical characteristic indicative of the capacitance of the system. The electrical characteristic may be the resultant voltage of the reference capacitor 52 where a fixed number of cycles is utilized to charge the electrodes 24 a and 24 b, or a cycle count (or time) where a variable number of pulses are utilized to charge the reference capacitor 52 to a predetermined voltage. The average capacitance of the sensor 18 over the cycles may also be directly computed. See, for example, the foregoing publications incorporated by reference herein, which describe various circuitry for carrying out such functions. It will be noted that where an obstruction exists, the dielectric constant between the electrodes 24 a and 24 b will change, typically increasing the capacitance of the elongate sensor 18 and thus affecting the recorded electrical characteristic.
[0038] In preferred embodiments, whenever the glass panel 16 is opened the controller 50 creates an opening capacitive reference map 60 by plotting the recorded electrical characteristic against the position (provided by a position sensor such as Hall effect sensor 54 ) of the glass panel 16 . In FIG. 4 , the opening reference map 60 is shown as a graph correlating cycle count against glass panel position. The controller 50 also measures a second capacitance map 62 (the “closing data”) as the glass panel 16 closes that is compared against the opening reference map 60 . Whenever the comparison exceeds a threshold value X for a period of time t, such as at dip 64 , an obstacle is detected. (Cycle count decreases if the capacitance of the sensor 18 increases.)
[0039] In order to deal with the possible presence of water on the sensor 18 , the controller 50 adjusts the threshold value based on the relative wetness of the sensor 18 , as shown in plot 80 of FIG. 6 . In this profile, “0” represents a dry seal 18 , and “3” a drenched seal 18 . For a dry seal, no change is made to an initial threshold value X 0 , but for wet seals the threshold value X varies in accordance with the degree of wetness.
[0040] The controller 50 determines the degree of wetness based on a calibration wetness profile 70 such as shown in FIG. 5 which is stored in non-volatile memory. The calibration profile 70 is based on empirical data obtained through known conditions of the elongate seal 18 . For instance, plot 72 is based on a dry seal; plots 74 , 75 are based on a seal that is wetted along 1/3 rd and 2/3 rd of its length respectively; and plot 76 is obtained from a completely wet seal all along its length. As will be seen, while the shape of each plot is quite similar, the cycle count differs because the capacitance of the seal 18 differs in each case. More granular data can be obtained, if desired, by further varying the wetting conditions.
[0041] Thus, in effecting the obstacle determination, the controller 50 compares the opening reference map 60 against the calibration wetness profile 70 to find the plot 72 , 74 , 75 or 76 that best matches the opening reference map 60 in order to identify the degree of wetness. In order to prevent the situation of the seal 18 becoming wet only after the glass panel is open (which is a more likely scenario with a powered sliding door system), the capacitance of the elongate seal 18 may more preferably be measured at a certain point such as at full opening (or over a certain range of positions) and compared against the capacitance value of these plots 72 , 74 , 75 or 76 at the same position(s) to determine the degree of wetness. Upon closing the glass panel 16 , the controller 50 signals an obstacle when the difference between the closing data 62 and the opening map 60 (at common positions) exceeds a threshold value X=X 0 +D (as a function degree wetness) for a period of time t. When an obstacle is signaled, the controller 50 preferably reverses motor 56 to move the glass panel 16 open.
[0042] In a third mode of operation, the controller 50 also monitors the position sensor 54 and/or the current drawn by the motor 56 . In the event of an obstacle, the position sensor will not increment and the current drawn by the motor will spike, thus indicating a pinch condition.
[0043] Preferably, the controller 50 utilizes all three modes of obstacle detection—sensor impedance, capacitive sensing and position/current monitoring to detect a pinch condition. The controller 50 may also eliminate the capacitive sensing mode from consideration after two or three serial obstacle detections and rely only on the other two modes in case the capacitive sensing mode has triggered a false positive.
[0044] While the above describes a particular embodiment(s) of the invention, it will be appreciated that modifications and variations may be made to the detailed embodiment(s) described herein without departing from the spirit of the invention. | A method for preventing a vehicular door or window panel from pinching an obstruction extending through an aperture of the vehicle by measuring a capacitance of a field extending through the aperture using a capacitive sensor as a motor drives the panel between the open and closed positions, correlating the measured capacitance to panel position to create closing data, comparing the closing data to a reference map to create a compare value, and detecting an object in a path of the panel as it moves toward the closed position when the compare value exceeds a threshold value. The threshold value is dependent on the relative wetness of the sensor, which is determined by comparing the capacitance of the sensor at predetermined panel positions against a calibration wetness profile. | 4 |
FIELD OF THE INVENTION
[0001] The present disclosure relates to a method of manufacturing a metal oxide and glass coated metal product. This invention also relates to a coated metallic substrate material that is suitable for manufacturing flexible solar cells and other articles in which a passivated stainless steel surface is desirable.
BACKGROUND
[0002] Photovoltaic cells are made by depositing various layers of materials on a substrate. The substrate can be rigid (e.g., glass or a silicon wafer) or flexible (e.g., a metal or polymer sheet).
[0003] The most common substrate material used in the manufacture of thin film Cu(In, Ga)Se 2 (CIGS) solar cells is soda lime glass. Soda lime glass contributes to the efficiency of the solar cell, due to the diffusion of an alkali metal (primarily sodium) from the glass into the CIGS layer. However, batch production of CIGS on glass substrates is expensive and glass is typically too rigid to be adapted to a roll-to-roll process. The disadvantages of using common glass substrates for the photovoltaic cells have motivated the search for substrates that are flexible, tolerant of the high temperatures used to create the photoactive layers, inexpensive and suitable for use in roll-to-roll processes.
[0004] Several materials have been tested as substrate materials for flexible CIGS solar cells, including polymers such as polyimide and metals such as molybdenum, aluminum and titanium foils. The substrate should be tolerant of temperatures up to 700° C. and reducing atmospheres. A metallic substrate must also be electrically insulated from the back contact to facilitate production of CIGS modules with integrated series connections. It is desirable for the coefficient of thermal expansion (CTE) of the substrate material to be as close as possible to the CTE of the electrical insulating material to avoid thermal cracking or delamination of the insulating material from the substrate.
[0005] CZTS-Se based solar cells are known, and are analogous to CIGS solar cells except that CIGS is replaced by CZTS-Se, where “CZTS-Se” encompass all possible combinations of Cu 2 ZnSn(S, Se) 4 , including Cu 2 ZnSnS 4 , Cu 2 ZnSnSe 4 , and
[0000] Cu 2 ZnSnS x Se (4-x) , where 0≦x≦4.
[0006] Since polymers are generally not thermally stable above 500° C., the focus has generally been on developing coated metal substrates.
[0007] Deposition of SiO x or SiO 2 layers onto metal strips in batch-type deposition processes is known.
[0008] It is also known to coat a metallic base with a first coat of an alkali silicate, optionally containing alumina particles. A second coat of silicone can be applied onto the first coat of an alkali silicate.
[0009] In another approach, a stainless steel plate is contacted with a solution of a metal alkoxide, an organoalkoxysilane, water, and thickeners such as alkoxy silane in an organic solvent, then dried and calcined.
[0010] A method for producing a substrate for solar batteries has also been disclosed in which a first insulating layer is formed on a metal plate (e.g., a stainless steel plate). Then the surface of the metal plate exposed by pinholes in the first insulating layer is oxidized by heating the metal plate in air. A second insulating layer is then applied over the first insulating layer.
[0011] A coated steel substrate useful as a substrate for flexible CIGS solar cells has been disclosed that comprises a stainless steel strip coated with a sodium-doped alumina layer onto which an electrically conducting layer of molybdenum has been deposited.
[0012] A process for forming an electrically insulating layer of aluminum oxide on ferritic stainless steel has been disclosed. The alumina-coated stainless steel sheet was used as a substrate for an amorphous silicon solar battery manufactured by P-CVD (plasma chemical vapor deposition) on the oxide film.
[0013] However, there remains a need for process to produce a substrate that has the flexibility of a metal, the surface properties of glass, and can be used in a roll-to-roll process for the manufacture of CIGS cells.
SUMMARY
[0014] One aspect of this invention is a process comprising:
a) depositing a glass precursor on at least a portion of an alumina-coated stainless steel substrate; and b) heating the glass precursor to form a glass layer on at least a portion of the alumina-coated stainless steel substrate, wherein the glass layer comprises SiO 2 , Al 2 O 3 , Na 2 O, and B 2 O 3 , and optionally an oxide selected from the group consisting of MgO, K 2 O, CaO, PbO, GeO 4 , SnO 2 , Sb 2 O 3 and Bi 2 O 3 .
[0017] Another aspect of this invention is a multi-layer article comprising:
a) a stainless steel substrate comprising 0.1 to 10 wt % aluminum; b) an alumina coating disposed on at least a portion of the stainless steel substrate; and c) a glass layer disposed on at least a portion of the alumina coating, wherein the glass layer comprises SiO 2 , Al 2 O 3 , Na 2 O, and B 2 O 3 and optionally an oxide selected from the group consisting of MgO, K 2 O, CaO, PbO, GeO 4 , SnO 2 , Sb 2 O 3 and Bi 2 O 3 .
DETAILED DESCRIPTION
[0021] One aspect of this invention is a process comprising the steps:
a) depositing a glass precursor on at least a portion of the surface of an alumina-coated stainless steel substrate; and b) heating the glass precursor to form a glass layer on at least a portion of the alumina-coated stainless steel substrate, wherein the glass layer comprises SiO 2 , Al 2 O 3 , Na 2 O, and B 2 O 3 , and optionally an oxide selected from the group consisting of MgO, K 2 O, CaO, PbO, GeO 4 , SnO 2 , Sb 2 O 3 and Bi 2 O 3 .
[0024] This process is useful for passivating a surface of the stainless steel substrate. The passivation may protect the surface from chemical attack. The alumina coating and glass layer may also serve as thermal and/or electrical insulating layers.
[0025] This process can be conducted batch-wise or as a continuous process, e.g., in a roll-to-roll process.
Stainless Steel Substrate
[0026] Suitable stainless steel substrates can be in the form of sheets, foils or other shapes. Sheets and foils are preferred for roll-to-roll processes. Suitable stainless steel typically comprises: 13-22 wt % chromium; 1.0-10 wt % aluminum; less than 2.1 wt % manganese; less than 1.1 wt % silicon; less than 0.13 wt % carbon; less than 10.6 wt % nickel; less than 3.6 wt % copper; less than 2 wt % titanium; less than 0.6 wt % molybdenum; less than 0.15 wt % nitrogen; less than 0.05 wt % phosphorus; less than 0.04 wt % sulfur; and less than 0.04 wt % niobium, wherein the balance is iron.
[0027] In some embodiments, the stainless steel comprises: about 13 wt % chromium; 3.0-3.95 wt % aluminum; less than 1.4 wt % titanium; about 0.35 wt % manganese; about 0.3 wt % silicon; and about 0.025 wt % carbon, wherein the balance is iron.
[0028] In some embodiments, the stainless steel comprises: about 22 wt % chromium and about 5.8 wt % aluminum, wherein the balance is iron.
[0029] For the purposes of the present invention, quantities of any component that are so small that they cannot be measured quantitatively by known and/or conventional methods are not considered to be within the scope of the present invention and, therefore, when only an upper compositional range limit is provided it should be understood to mean that the lower limit is any quantity measureable by known or conventional means.
Alumina-Coated Stainless Steel Substrate
[0030] A suitable alumina-coated stainless steel substrate can be prepared by annealing a stainless steel sheet, foil or article that has a composition as described above. The annealing is typically carried out in an oxygen-containing atmosphere at a temperature between 800 and 1000° C. for at least 15 hr, or between 1000 and 1100° C. for at least 9 hr, or between 1100 and 1200° C. for at least 6 hr. A suitable thickness of the alumina layer formed by the annealing process is typically about 0.001 to about 1.000 microns.
[0031] Depending on the initial composition of the stainless steel, other elements may also migrate to the surface during the annealing and form islands of metal oxides (e.g., titanium oxide, iron oxide and/or chromium oxide) on the surface of the alumina-coated stainless steel. As used herein, the alumina layer is understood to both the alumina and the islands of other metal oxides.
Glass Precursor Layer
[0032] In one aspect of this invention, the alumina layer of the alumina-coated stainless steel substrate is further coated with a glass precursor layer, followed by steps of drying and firing the glass precursor layer to form a glass layer on the stainless steel substrate. As described below, the thickness of the glass layer can be increased by carrying out multiple cycles of coating-and-drying before firing, or by carrying out several cycles of coating-drying-and-firing.
[0033] The glass layer is formed by coating an alumina-coated stainless steel substrate with a glass precursor composition. The precursor composition typically contains: a soluble form of silicon, (e.g., silicon tetraacetate, silicon tetrapropionate, bis(acetylacetonato) bis(acetato) silicon, bis(2-methoxyethoxy) bis (acetato) silicon, bis(acetylacetonato) bis(ethoxy) silicon, tetramethylorthosilicate, tetraethylorthosilicate, tetraisopropylorthosilicate, or mixtures thereof), dissolved in a minimum amount of a C1-C10 alcohol (e.g., methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isomers of 1-butanol, 1-pentanol, 2-pentanol, 3-pentanol, isomers of pentanol, 1-hexanol, 2-hexanol, 3-hexanol, isomers of hexanol, 1-heptanol, isomers of heptanol, 1-octanol, isomers of octanol, 1-nonanol, isomers of nonanol, 1-decanol, isomers of decanol, ethylene glycol, 1-methoxyethanol, 1-ethoxyethanol, or mixtures thereof); a trialkylborate (e.g., trimethylborate, triethylborate, tripropylborate, trimethoxyboroxine, or mixtures thereof); a sodium salt (e.g., sodium acetate, sodium propionate, sodium silicate, sodium alkoxides, or mixtures thereof); optionally, a potassium salt (e.g., potassium acetate, potassium propionate, potassium methoxide, potassium ethoxide, potassium isopropoxide, or mixtures thereof); and an aluminum compound (e.g., tris(acetylacetonato) aluminium, aluminium methoxide, aluminium ethoxide, aluminium isopropoxide, aluminium n-propoxide, or mixtures thereof). In some embodiments, the glass precursor formulation is filtered prior to coating the stainless steel substrate. In some embodiments, the composition of the glass precursors in the formulation is in a ratio of about 100 to 27 to 12 to 3 to 3 with respect to the elements: Si, B, Na, K, and Al.
[0034] In one embodiment, the precursor composition is prepared by dissolving a silicon oxide precursor (e.g., silicon tetraacetate) in a minimum amount of 1-butanol, or a 1:1 mixture of 1-butanol and propionic acid, and stirring. To this solution, an aluminium oxide precursor (e.g., tris(acetylacetonato)aluminium), a boron oxide precursor (e.g., triethyl borate), a sodium oxide precursor (e.g., sodium acetate) and a potassium oxide precursor (e.g., potassium propionate) are added. Once the precursors are dissolved, more solvent is added to obtain the desired concentration.
[0035] Suitable precursors for MgO, K 2 O, CaO, PbO, GeO 4 , SnO 2 , Sb 2 O 3 and Bi 2 O 3 include the respective acetates: potassium acetate, calcium acetate, lead acetate, germanium acetate, tin acetate, antimony acetate, and bismuth acetate.
[0036] Silicon alkoxides (e.g., silicon tetraorthosilicate) and aluminum alkoxides (e.g., aluminum isopropoxide) can also be used to prepare the glass precursor compositions. However, these materials hydrolyze in the presence of water, so they should be stored under anhydrous conditions.
[0037] Optionally, borosilicate glass nanoparticles can be added to the formulation.
Coating, Drying and Firing
[0038] Coating the glass precursor composition onto the alumina-coated stainless steel substrate can be carried out by any conventional means, including bar-coating, spray-coating, dip-coating, microgravure coating, or slot-die coating.
[0039] After coating the glass precursor composition onto the alumina-coated stainless steel substrate, the precursor is typically dried in air at 100 to 150° C. to remove solvent. In some embodiments, the dried glass precursor layer is then fired in air or an oxygen-containing atmosphere at 250 to 800° C. to convert the glass precursor layer to a fired glass layer.
[0040] In some embodiments, additional cycles of coating and drying are carried out prior to firing. This increases the thickness of the fired glass layer.
[0041] In some embodiments, the steps of coating, drying, and firing are repeated 2 or more times. This can also increase the total thickness of the fired glass layer. Multiple intermediate firing steps facilitate removal of any carbon that might be present in the glass precursor components.
[0042] In some embodiments, water is added to the precursor mixture prior to the coating step. This increases the viscosity of the glass precursor composition and facilitates the formation of glass layers of 50 nm to 2 microns thickness in one coating and drying cycle.
[0043] Both the firing step(s) and drying step(s) are typically conducted in air to ensure complete oxidation of the glass precursors. The presence of elemental carbon, carbonate intermediates or reduced metal oxides in the glass layer may lower the breakdown voltage of the insulating layer.
Glass Layer
[0044] After firing, the glass layer typically comprises: greater than 70 wt % silica; less than 10 wt % alumina; 5-15 wt % of a boron oxide; and less than 10 wt % of oxides of sodium and/or potassium. In one embodiment, the fired glass layer comprises: about 81 wt % SiO 2 , about 13 wt % B 2 O 3 , about 4 wt % Na 2 O, and about 2 wt % Al 2 O 3 .
[0045] In some embodiments, the glass precursor compositions are selected to provide coefficients of linear thermal expansion of the glass layers to be close to those of the Mo and CIGS (or CZTS-Se) layers to reduce stress on the Mo and CIGS (or CZTS-Se) layers and to reduce film curling. In some embodiments, the CTE of the borosilicate glass is about 3.25×10 −6 /° C. to provide a good match to the CTE of the Mo layer (about 4.8×10 −6 /° C.) and the CIGS layer (about 9×10 −6 /° C.).
Device
[0046] One aspect of this invention is a multi-layer article comprising:
a) a stainless steel substrate comprising 1 to 10 wt % aluminum; b) an alumina coating disposed on at least a portion of the stainless steel substrate; and c) a glass layer disposed on at least a portion of the alumina coating, wherein the glass layer comprises SiO 2 , Al 2 O 3 , Na 2 O, B 2 O 3 , and optionally an oxide selected from the group consisting of MgO, K 2 O, CaO, PbO, GeO 4 , SnO 2 , Sb 2 O 3 and Bi 2 O 3 .
[0050] The stainless steel substrate, alumina coating and glass layer are as described above.
[0051] This multilayer article can be used as the substrate for the manufacture of electronic devices. Such multilayer articles can also be used in medical devices.
[0052] In some embodiments, the multilayer article further comprises:
d) a conductive layer disposed on at least a portion of the glass layer.
[0054] In some embodiments, the multilayer article further comprises:
e) a photoactive layer disposed on the conductive layer; f) a CdS layer disposed on the photoactive layer; and g) a transparent conductive oxide disposed on the CdS layer.
[0058] Such multilayer articles can be used in photovoltaic cells.
[0059] Suitable conductive layers comprise materials selected from the group consisting of metals, oxide-doped metals, metal oxides, organic conductors, and combinations thereof. A conductive metal layer can be deposited onto the glass layer through a vapor deposition process or electroless plating. Suitable metals include Mo, Ni, Cu, Ag, Au, Rh, Pd and Pt. The conductive metal layer is typically 200 nm-1 micron thick. In one embodiment, the conductive material is molybdenum oxide-doped molybdenum.
[0060] In some embodiments, the multilayer article comprises organic functional layers, e.g., organic conductors such as polyaniline and polythiophene. In such embodiments, the multilayer article is generally not heated above 450° C., or 400° C., or 350° C., or 300° C., or 250° C., or 200° C., or 150° C., or 100° C. after the organic functional layer has been deposited.
[0061] Suitable photoactive layers include CIS (copper-indium-selenide), CIGS, and CZTS-Se.
[0062] The CIGS and CIS layers can be formed by evaporating or sputtering copper, indium and optionally gallium sequentially or simultaneously, then reacting the resulting film with selenium vapor. Alternatively, a suspension of metal oxide particles in an ink can be deposited on the conductive layer using a wide variety of printing methods, including screen printing and ink jet printing. This produces a porous film, which is then densified and reduced in a thermal process to form the CIGS or CIS layer.
[0063] CZTS-Se thin films can be made by several methods, including thermal evaporation, sputtering, hybrid sputtering, pulsed laser deposition, electron beam evaporation, photochemical deposition, and electrochemical deposition. CZTS thin-films can also be made by the spray pyrolysis of a solution containing metal salts, typically CuCl, ZnCl 2 , and SnCl 4 , using thiourea as the sulfur source.
[0064] The CdS layer can be deposited by chemical bath deposition.
[0065] A suitable transparent conductive oxide layer, such as doped zinc oxide or indium tin oxide, can be deposited onto the CdS layer by sputtering or pulsed layer deposition.
EXAMPLES
General
Preparation Of Alumina-Coated Stainless Steel Foils For Examples 1-3:
[0066] A 50.8 micrometer thick stainless steel foil (Ohmaloy® 30, 2-3 wt % aluminum, ATI Allegheny Ludlum) was annealed at 1000° C. in air for 15 hr to provide a coating of alumina on the surface of the stainless steel foil.
[0067] The foil was then diced to size and argon plasma-cleaned (A.G. Services PE-PECVD System 1000) for 30 sec under the following conditions:
[0068] power=24.3 W
[0069] pressure=100.0 mTorr
[0070] throttle pressure=200.0 mTorr
[0071] argon gas flow=10.0 sccm
Preparation of a Precursor Composition Containing 0.2 M [Si]:
[0072] Silicon tetraacetate (3.6695 g, 13.89 mmol) was dissolved in 1-butanol (60.00 ml) containing 0.25 ml of deionized water. To this solution, was added triethylborate (0.5616 g, 3.85 mmol), sodium acetate (0.1721 g, 1.79 mmol), potassium propionate (0.0429 g, 0.44 mmol) and tris(acetylacetonato) aluminum (0.1311 g, 0.40 mmol). The solution was stirred and 1-butanol was added until a total volume of 100.00 ml was achieved. The glass precursor composition was filtered through a 2 micron filter prior to coating the stainless steel substrate.
Rod-Coating:
[0073] The substrates were rod-coated using a #20 bar on a Cheminstrument® motorized drawdown coater at room temperature in a clean room environment (class 100). The coated substrate was then dried at 150° C. for 1 min to form a dried glass precursor layer on the annealed stainless steel substrate. This procedure was used one or more times in each of the examples described below.
Firing:
[0074] After drying, the coated substrates were fired to 600° C. for 30 min at a ramp rate of 8° C./s using a modified Leyboldt L560 vacuum chamber outfitted with cooled quartz lamp heaters above and below the coated substrate, with an air bleed of 20 sccm (total pressure 1 mTorr). Out-gassing was monitored using a residual gas analyzer. This procedure was used one or more times in each of the examples described below.
Determination of Dielectric Strength:
[0075] Breakdown voltage was measured with a Vitrek 944i dielectric analyzer (San Diego, Calif.). The sample was sandwiched between 2 electrodes, a fixed stainless steel rod as cathode (6.35 mm diameter and 12.7 mm long) and a vertically sliding stainless steel rod as anode (6.35 mm diameter and 100 mm long). The mass of the sliding electrode (32.2 g) produced enough pressure so the anode and cathode form good electrical contact with the sample. The voltage was ramped at 100 V/s to 250 V and kept constant for 30 sec to determine the breakdown voltage and the sustained time. The thickness was measured using a digital linear drop gauge from ONO SOKKI, model EG-225. Dielectric strength can be calculated as the breakdown voltage per unit of thickness.
EXAMPLE 1
One Firing of Multiple Layers
[0076] The filtered glass precursor composition (0.1 ml) was rod-coated onto an annealed, plasma-cleaned stainless steel substrate and dried, as described above.
[0077] The drawdown coating and drying cycle was repeated five times. The substrate was then fired, as described above.
[0078] Breakdown voltage was found to be 520-600 V DC at 10 randomly selected locations.
[0079] After firing, a 200 nm Mo coating was deposited on the fired glass layer via sputter vapor deposition.
EXAMPLE 2
Deposition of a Single Layer Which is then Fired, Followed by Deposition of Subsequent Layers Which are then Fired
[0080] The filtered glass precursor composition (0.1 ml) was rod-coated onto an annealed, plasma-cleaned stainless steel substrate and dried, as described above.
[0081] This layer was then fired as described above.
[0082] The drawdown coating and drying cycle was repeated under the same conditions five times. The coated substrate was fired a second time, and then a 200 nm Mo layer was deposited on the fired glass layer via sputter vapor deposition.
EXAMPLE 3
Multiple Firing Process
[0083] The filtered glass precursor composition (0.1 ml) was rod-coated onto an annealed, plasma-cleaned stainless steel substrate and dried, as described above.
[0084] This layer was then fired as described above.
[0085] The cycle of coating, drying and firing steps was repeated five times.
[0086] A 200 nm Mo top electrode was deposited onto the fired glass layer via sputter vapor deposition.
COMPARATIVE EXAMPLE A
Borosilicate Glass Coating Directly on Stainless Steel
[0087] This example demonstrates that a coating of a borosilicate glass alone on a stainless steel substrate leads to lower breakdown voltages.
[0088] A 50.8 micrometer thick stainless steel foil (stainless steel 430, ATI Allegheny Ludlum) was diced to size and argon plasma-cleaned (A.G. Services PE-PECVD System 1000) for 30 sec under the following conditions:
[0089] power=24.3 W
[0090] pressure=100.0 mTorr
[0091] throttle pressure=200.0 mTorr
[0092] argon gas flow=10.0 sccm
[0000] This stainless steel substrate is similar to that used in Examples 1-3, except that it contains less than 5 microgram/g of aluminum, and was not annealed before being coated with a glass precursor composition.
[0093] The filtered glass precursor formulation (0.1 ml) was rod-coated onto a plasma-cleaned stainless steel substrate and dried.
[0094] This layer was then fired as described above.
[0095] The cycle of coating, drying and firing steps was repeated five times.
[0096] The breakdown voltage was found to be variable and inconsistent over the top surface of the glass-coated stainless steel.
[0097] A 200 nm Mo top electrode was deposited onto the fired glass layer via sputter vapor deposition. | The present disclosure relates to a method of manufacturing of a metal oxide and glass coated metal product. This invention also relates to a coated metallic substrate material that is suitable for manufacturing flexible solar cells and other articles in which a passivated stainless steel surface is desirable. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to packaging with a convex front and back and with a decoratively shaped periphery.
2. Description of Related Art
Packages distributed for promotional purposes ought to have a high visual impact. When the packages are delivered by hand or through the mail, the recipient will look at the package for only a short time before deciding whether to open or discard the item. Accordingly, an effective promotional package must have high visual impact to attract the recipient and arouse curiosity about the package contents. Also postal regulations and rates may favor packages having a certain thickness.
U.S. Pat. No. 3,343,743 shows a common package formed essentially of a pair of panels folded together to form an enclosure. The end flaps of the panels are scored to form closure flaps having a lenticular outline. When the package is closed, the outside of the two panels are convex while the flaps take a concavo-convex shape when closed. See also U.S. Pat. No. 359,435.
U.S. Pat. No. 3,964,606 shows a similar package with large hangtags extending from adjacent straight edges of the front and rear panels. These hangtags are sized and position in a way that limits the ability to change the outline and the visual impact of the package.
U.S. Pat. No. 4,887,709 shows another convex package with a hangtag projecting from a rounded edge of the back panel. Again, the hangtag is sized and positioned in a way that restricts the ability to greatly change the visual impact of the package.
U.S. Pat. No. 2,964,227 shows another convex package wherein one of the exposed panels is extended into a pleated section that can be tucked inside the package when closed. Because these additional pleats are inside the package, they are not visible and do not affect the visual impact of the package.
Other related packages are shown in U.S. Pat. Nos. 3,010,571; 3,637,130; 4,032,005; and 5,061,501.
Accordingly, there is need for a package that is arranged to have a shape that can be easily varied to present a high visual impact.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a package containing an enclosed space of a predetermined width. The package has an internal panel, an external panel, and an overlay panel. The internal panel has a main section with an opposing pair of internal edges spaced by at least the predetermined width. The internal panel also has a primary closure flap hingedly connected to the main section along a curved fold line. The curved fold line is substantially transverse to the internal edges. The curved fold line is also bowed inwardly to impart to the primary closure flap a concavo-convex shape. The external panel is hingedly connected along a longitudinal fold line to one of the internal edges of the internal panel. The external panel is folded along the longitudinal fold line to a position alongside the internal panel. The internal and the external panels are on opposite sides of the enclosed space. The overlay panel is hingedly connected along an exterior fold line to the external panel. The overlay panel is non-rectangular and is folded to a position alongside the internal panel. The overlay panel and the external panel are on opposite sides of the enclosed space.
According to another aspect of the invention a package blank for containing an enclosed space of a predetermined width, also has an internal panel, an external panel, and an overlay panel. The internal panel has a main section with an opposing pair of internal edges spaced by at least the predetermined width. The internal panel also has a primary closure flap hingedly connected to the main section along a curved fold line. The curved fold line is substantially transverse to the internal edges. The curved fold line is also bowed inwardly for imparting to the primary closure flap a concavo-convex shape. The external panel is hingedly connected along a longitudinal fold line to one of the internal edges of the internal panel. The external panel is adapted for folding along the longitudinal fold line to a position alongside the internal panel to place the internal and the external panels on opposite sides of the enclosed space. The overlay panel is hingedly connected along an exterior fold line to the external panel. The overlay panel is adapted for folding to a position alongside the internal panel. The overlay panel is also sized to present a facade with at least one dimension substantially greater than a corresponding dimension of the enclosed space. The overlay panel has an irregular periphery with portions more complex than either the curved or the longitudinal fold lines.
According to still another aspect of the present invention a packaging method is provided, employing a non-rectangular overlay panel and an internal panel hingedly connected on opposite sides of an external panel. This packaging method can contain an enclosed space of a predetermined width. The method includes the step of folding the internal panel to a position alongside the external panel to straddle the enclosed space. Another step is folding the overlay panel to a position alongside the internal panel, (A) to place the overlay panel and the external panel on opposite sides of the enclosed space, and (B) to position the overlay panel as a facade extending at least partially beyond the enclosed space. The method also includes the step of bending a portion of the internal panel along a curved fold line to a position substantially transverse to the external and the overlay panels. The curved fold line is bowed inwardly to impart to the primary closure flap a concavo-convex shape.
By employing packages and packaging methods of the foregoing type, an interesting appearance or a high visual impact can be achieved. In the preferred embodiments an overlay panel of an almost arbitrary outline can extend from an external panel that forms part of the structure of the package. The external panel may itself have an almost arbitrary outline that complements the outline of the overlay panel. When folded and assembled, the package can appear with this almost arbitrary outline.
In various embodiments, the package can employ one or more concavo-convex end flaps. In some embodiments the enclosed space of the package will between the external panel and an internal panel, with the overlay panel being primarily ornamental. In other embodiments the enclosed space of the package will be between the internal panel and an inside panel hingedly attached to the internal panel. The fold line between the overlay panel and the external panel (as well as between the external panel and the internal panel) may be a simple straight fold line, or an interrupted fold line (for example, two aligned folds separated by a gap).
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is developmental view of a blank for forming a package in accordance with the principles of the present invention;
FIG. 2 shows the package blank of FIG. 1 in the process of being folded to form a package;
FIG. 3 shows a completed package formed from the blank of FIG. 1;
FIG. 4 is a detailed end view of the package of FIG. 3 with its two closure flaps open;
FIG. 5 is an end view of a package of FIG. 4 with one of the flaps of FIG. 4 closed;
FIG. 6 is an end view of the package of FIG. 4 with both flaps of FIG. 4 closed;
FIG. 7 is developmental view of a package blank that is an alternate to that of FIG. 1;
FIG. 8 is developmental view of a package blank that is an alternate to that of FIG. 1;
FIG. 9 is developmental view of a package blank that is an alternate to that of FIG. 1; and
FIG. 10 is developmental view of a package blank that is an alternate to that of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a package blank that is die cut from a sheet material such as solid bleach sulfate folding board, although other types of materials can be used; for example, chipboard, heavy weight paper, sheet plastic etc. The blanks can formed by feeding a stack of individual sheets to a reciprocating die that can cut through the stack. Alternatively, a rotary die can cut package blanks from a web fed past the die.
These types of dies can have sharp ridges that mate with grooves on an opposing plate or cylinder. Alternatively, the cutting die can be opposed simply by an ungrooved plate or cylinder. Besides cutting with sharp ridges, the blank can be scored by rounded ridges that provide fold lines. Alternatively, the fold lines can be created by a ridge that has sharp sections alternating with dull sections, so that the fold line is perforated as well as scored. The latter type of operation is referred to as skip scoring. The dashed lines in FIG. 1 indicate skip scoring. The solid internal lines (that is, lines that do not constitute the outer periphery of the blank) represent score lines for folding. It will be appreciated however any fold line can be either scored or skipped scored, depending upon the requirements of the particular embodiment.
The blank of FIG. 1 is shown segregated into four main panels: overlay panel 10, external panel 12, internal panel 14 and inside panel 16. The internal panel 14 has at opposite ends an opposing pair of closure flaps, herein referred to as primary closure flap F1 and distal flap F3. The flaps F1 and F3 have a lenticular shape, although other shapes are contemplated such as linear segments. The primary closure flap F1 is integral with the main section of internal panel 14 and is separated by the skip scoring along curved fold line 20. Similarly, closure flap 3 is separated from the main section of internal panel 14 by the skip scoring along fold line 22.
Inside panel 16 has substantially the same length and width as internal panel 14. Internal panel 14 has a predetermined width defined as the dimension between internal edges 28 and 30. (Length refers to the longest, longitudinal dimension of the panel, while width is the dimension transverse thereto.) In this embodiment internal edge 28 also acts as a longitudinal fold line between panels 12 and 14. The inside panel 16 also has an opposite pair of closure flaps F2 and F4, joined by skip scoring to the main section of inside panel 16 by fold lines 24 and 26, respectively. The outside edges of flaps F2 and F4 are notched to provide finger holes for the purposes described presently. The rightmost edge (in this view) of inside panel 16 terminates with an attachment flap 18, designed to secure the panels together in a manner to be described presently.
External panel 12 is shown with an irregular border, which is essentially a mirror image of overlay panel 10. Therefore both of these irregular peripheries are considered complementary borders. The panels 10 and 12 are integrally joined by an exterior fold line, shown as interrupted fold line segments 30A and 30B. It will be noted that panels 10 and 12 have substantially greater area than panels 14 and 16. Specifically, panels 10 and 12 are longer and wider than panels 14 and 16.
As described presently, the package blank of FIG. 1 will be folded and held together by gluing. In this embodiment, adhesive is laid down in spots, strips or beads. For example in FIG. 1, a bead of adhesive will be laid along strip B (shown as a wavy line) on the face of panel 12 that is visible in this view (strip B is also referred to as the attachment region 36). This adhesive strip will attach to a mating strip B, which is on the reverse side of panel 16 and is therefore shown in phantom. It will be appreciated that the adhesive can be placed in either of the corresponding positions or both depending upon the desired holding strength tolerances etc.
Similarly, a strip A of adhesive laid on the illustrated side of panel 14 will mate with a strip A on the reverse side of attachment panel 18. Attachment panel 18 is integral connected to panel 16 along fold line 19. Also, the bead C of adhesive on the illustrated side of panel 10 will mate with the strip C on the reverse side of panel 14. Strips A and C are in registry on opposite sides of panel 14.
As will be explained presently, panels 14 and 16 will be folded together and then folded against panel 12. Because panel 12 is wider than panels 14 and 16, there will be an excess portion 34 (herein referred to as an ornamental portion) that exists beyond the attachment region 36. Being complementary, panel 10 also has a complementary ornamental section 38.
Referring now to FIGS. 1, 2 and 3, adhesive must be applied first to strips A, B and C (either one or both members of each mating pair) before assembly. Next, the attachment flap 18 is folded along line 19 to lie against the illustrated side of panel 16. Thereafter, inside panel 16 is folded along line to bring strip A of attachment flap 18 against strip A of internal panel 14, thereby gluing them together.
Next, panel 14 (together with panel 16 and flap 18) is folded along line 28. This brings together adhesive strips B on panels 16 and 12. Finally, overlay panel 16 is folded along lines 32A-32B to bring its adhesive strips C against the adhesive strip C on panel 14.
The assembly at this point is a flat package in which successive panels spiral inwardly. The panels that are touching are glued together except for the inside faces of panels 14 and 16, which embrace the previously mentioned enclosed space.
An object can be placed in the enclosed space between panels 14 and 16 by being inserted, for example, through the end bordered by closure flaps F1 and F2, as shown in FIG. 4. The object that can be inserted maybe a letter or a promotional sample, such as a perfume vial, detergent sample, or the like. After insertion into the enclosed space, the two ends of the package can be closed. As shown in FIG. 4, flaps F1 and F2 start parallel to the outside surfaces. The first flap F1 can be folded in along the curved fold line 20. Because fold line 20 is curved, flap F1 forms a concavo-convex shape as shown in FIG. 5.
Next, flap F2 can be folded up against flap F1. Being attached to the package also by a curved fold line (see FIG. 1) flap F2 forms the concavo-convex shape shown in FIG. 6. Flap F2 is shown with a finger notch, which facilitates opening of the subsequent opening of the package. The flap F2 can be held closed by means of transparent adhesive tape. It will be appreciated that the flaps at the opposite end at the package can be closed in a similar fashion.
Because the flaps at either end of the package have a lenticular shape, they bow the sides of the package as shown in FIG. 3.
The package shown in FIG. 3 has an irregular periphery that is substantially different than the periphery of the enclosed space inside the package. Because overlay panel 10 (and its complementary panel 12 on the reverse side) are larger than the package per se, the excess fringe area can be shaped in an arbitrary fashion.
Referring to FIG. 7, an alternate package blank is illustrated that is almost identical to FIG. 1. Specifically, panels 40, 42, 44, and 46 correspond to previously illustrated panels 10, 12, 14, and 16, respectively. Panels 44 and 46 have flaps F5 and F6 corresponding to flaps F1 and F2 of FIG. 1, as well as an attachment flap 48, corresponding to flap 18 of FIG. 1.
Panels 44 and 46 however, do not have closure flaps on the ends opposite flaps F5 and F6. Instead, these end portions are cut straight and adhesive strips 50 and 52 are placed adjacent the straight ends. The package is folded as before with the result that panels 44 and 46 are glued together along strips 50 and 52, opposite flaps F5 and F6. Consequently, the resulting package will be very similar to that shown in FIG. 3 except that the bowing will be predominantly at the end having flaps F5 and F6. The bowing will gradually decrease until reaching the ends having adhesive strips 50 and 52, where the package will have a thickness only that of the composite thicknesses of the material stacked at that end.
Referring to FIG. 8, a package blank is shown having an overlay panel 54, an external panel 56, a internal panel 58, an inside panel, 60 and an attachment flap 62, corresponding in most respects to items 10, 12, 14, 16, and 18, respectively, of FIG. 1. In this embodiment, internal panel 58 is wider than inside panel 60. Accordingly, the portion of panel 58 adjacent panel 56 will, upon folding, extend beyond panel 60 and can be cut for decorative purposes. Accordingly, the interrupted fold lines 57A and 57B between panels 56 and 58, are part of a curved outline that will be visually prominent after folding.
As before, adhesive strip A on the illustrated side of panel 58 will mate with adhesive strip A on the reverse side of attachment panel 62. Thus, flap 62 is folded up against the illustrated side of panel 60, before panel 60 is itself folded along fold line 59 against panel 58 to bring together adhesive strips A--A on items 58 and 62.
Next, panels 58 and 60 may be folded as a pair along interrupted longitudinal fold lines 57A and 57B against the illustrated side of panel 56 to bring the adhesive spots B--B and C--C on panels 56 and 58 together. Finally, overlay panel 54 can be folded along interrupted exterior fold lines 64A and 64B to bring the illustrated side of panel 54 against the reverse side of panel 58, thereby bringing together adhesive spots F--F and E--E. Also, the extended portions of panels of 54 and 56 will connect together by means of the adhesive spots D--D.
In this embodiment, the ends of panels 58 and 60 opposite flaps F7 and F8 are not glued together. Nevertheless, an article contained between these panels will not fall out because panels 54 and 56 will be linked across this otherwise open end and secured by means of adhesive spots D--D. Although this type of closure is not a tight seal, is adequate to retain a folded letter or similar article.
Once folded together in this fashion, flaps F7 and F8 can be closed in a manner similar to that described in connection with FIG. 1.
An important difference with the embodiment with FIG. 8 is the fact is that the panels 54 and 56 can extend past all four sides of the enclosed space formed between panels 58 and 60. In particular, panel 58 has an extended portion in the vicinity of fold lines 57A and 57B that can facilitate this feature. Thus, the regions at the interface between panels 58 and 56 contribute two ornamental regions that implement the decorative effect. Similarly, at the fold lines 64A and 64B, there is a ornamental region on panel 56 and an ornamental section on panel 54, implementing a decorative border.
Referring to FIG. 9, an alternate package blank is shown, wherein only three panels are employed, which saves material costs. In this embodiment, panels 68 and 70 correspond essentially to panels 14 and 16 of FIG. 1, and have the same dimensions. Also, attachment flap 72 corresponds to flap 18 of FIG. 1. Panel 68 has closure flaps F9 and F11, while panel 70 has closure flaps F10 and F12, which are essentially the same as the closure flaps shown in FIG. 1 for the corresponding panels (except for the different placement of the illustrated finger notches).
Therefore, attachment flap 72 can be folded along fold line 71 and then brought into contact with panel 68 when panel 68 and 70 are folded together by folding along longitudinal fold line 67. At that time adhesive strip A on the reverse side of flap 72 attaches to the adhesive strip A on the illustrated side of panel 68. Consequently, panels 68 and 70 form another enclosed space. The fold line 67 between internal panel 70 and external panel 68 is a straight line.
When overlay panel 66 is folded along exterior fold line 65 against panel 70, the adhesive strips B--B attach. In this embodiment the overlay panel 66 has the same width as the other panels 68 and 70. In this embodiment the overlay panel 66 extends outwardly in the vicinity of the flaps F9 through F12 to present an outline simulating the shape of a cellular phone.
Referring to FIG. 10, an alternate package blank is shown with an internal panel 76 similar to panel 70 in FIG. 9, and with a closure flap F14, and an attachment flap 78 adjacent thereto, but with the end opposite flap F14 cut straight. Attachment flap 78 may be folded along line 80 up against the illustrated side of panel 76. Thereafter, panel 76 can be folded along longitudinal fold line 82 against the illustrated side of panel 74, so that the adhesive strips A--A join and form an enclosed space. Because panel 74 is wider than panel 76, there is an excess region 74A that may be act as an ornamental region.
Accordingly, panel 74 is shown with an irregular border in the vicinity of adhesive strip B and adhesive spots C and D. Similarly, overlay panel 72 has an ornamental section 72A in the vicinity of exterior fold line 73. Other than needing a common fold line with panel 74, the borders of panel 72 are not constrained and may have an arbitrarily decorative shape. Here, panel 72 is designed to have a border complementing that of panel 74.
When panel 72 is folded along line 73 against the reverse side of panel 76, adhesive strips E--E connect. Also, the portions of panels 74 and 72 extending beyond panel 76 each have adhesive spots C and D that connect together. As before, the adhesive spots on panel 74 and 72 close the enclosed space between panels 74 and 76 at the end opposite flaps F14 and F15. This closure is adequate to retain a folded letter or similar article. As before, an article can be inserted between flaps F14 and F15, which may then be folded inwardly to bow the panels 72, 74, 76 in the manner previously described.
It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiment. For example, the various lengths and widths of the panels can be altered depending upon the article being packaged. In addition, the ornamental or decorative borders of the various panels can be changed depending on the desired appearance. Also, while the external and overlay panels are shown having complementary shapes, in some embodiments they may have different shapes and thus provide different projections at different locations. Furthermore, the outlines of the enclosure flaps can be varied, and in some embodiments may have a polygonal outline. Moreover, the above adhesive strips and spots for securing the panels, can be arranged in other ways. Also, instead of securing with an adhesive, the panels may be secured by adhesive tape, staples, rivets, snaps or other attachment devices. Additionally, while the panel blanks are shown cut from a single sheet, in some embodiments it may be desirable to piece separate panels together by gluing, taping or by other means.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims. The invention may be practiced otherwise than as specifically described. | A package containing an enclosed space of a predetermined width, includes an internal panel, and external panel and an overlay panel. The internal panel has a main section with an opposing pair of internal edges spaced by at least the predetermined width. A primary closure flap is hingedly connected to the main section along a curved fold line. This curved fold line is substantially transverse to the internal edges. The curved fold line is also bowed inwardly to impart to the primary closure flap a concavo-convex shape. The external panel is hingedly connected along a longitudinal fold line to one of the internal edges of the internal panel. The external panel is folded along the longitudinal fold line to a position alongside the internal panel. The internal and the external panels are on opposite sides of the enclosed space. The overlay panel is hingedly connected along an exterior fold line to the external panel. The overlay panel is folded to a position alongside the internal panel. The overlay panel and the external panel are on opposite sides of the enclosed space. The overlay panel is non-rectangular and is sized to present a facade with at least one dimension substantially greater than a corresponding dimension of the enclosed space. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/636,471 filed Dec. 11, 2009, which is a continuation of, and claims the benefit of priority from co-pending U.S. application Ser. No. 11/962,654, now U.S. Pat. No. 7,655,015, filed Dec. 21, 2007, which is a divisional of U.S. patent application Ser. No. 10/441,531, now U.S. Pat. No. 7,563,267, filed May 19, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 09/894,463, now U.S. Pat. No. 6,752,813, filed Jun. 27, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/544,930, now U.S. Pat. No. 6,629,534, filed Apr. 7, 2000, which claims the benefit of prior U.S. Provisional Patent Application No. 60/128,690, filed on Apr. 9, 1999 under 37 CFR §1.78(a), the full disclosures of which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical methods, devices, and systems. In particular, the present invention relates to methods, devices, and systems for the endovascular, percutaneous or minimally invasive surgical treatment of bodily tissues, such as tissue approximation or valve repair. More particularly, the present invention relates to repair of valves of the heart and venous valves.
[0004] Surgical repair of bodily tissues often involves tissue approximation and fastening of such tissues in the approximated arrangement. When repairing valves, tissue approximation includes coapting the leaflets of the valves in a therapeutic arrangement which may then be maintained by fastening or fixing the leaflets. Such coaptation can be used to treat regurgitation which most commonly occurs in the mitral valve.
[0005] Mitral valve regurgitation is characterized by retrograde flow from the left ventricle of a heart through an incompetent mitral valve into the left atrium. During a normal cycle of heart contraction (systole), the mitral valve acts as a check valve to prevent flow of oxygenated blood back into the left atrium. In this way, the oxygenated blood is pumped into the aorta through the aortic valve. Regurgitation of the valve can significantly decrease the pumping efficiency of the heart, placing the patient at risk of severe, progressive heart failure.
[0006] Mitral valve regurgitation can result from a number of different mechanical defects in the mitral valve or the left ventricular wall. The valve leaflets, the valve chordae which connect the leaflets to the papillary muscles, the papillary muscles or the left ventricular wall may be damaged or otherwise dysfunctional. Commonly, the valve annulus may be damaged, dilated, or weakened, limiting the ability of the mitral valve to close adequately against the high pressures of the left ventricle.
[0007] The most common treatments for mitral valve regurgitation rely on valve replacement or repair including leaflet and annulus remodeling, the latter generally referred to as valve annuloplasty. A recent technique for mitral valve repair which relies on suturing adjacent segments of the opposed valve leaflets together is referred to as the “bow-tie” or “edge-to-edge” technique. While all these techniques can be very effective, they usually rely on open heart surgery where the patient's chest is opened, typically via a sternotomy, and the patient placed on cardiopulmonary bypass. The need to both open the chest and place the patient on bypass is traumatic and has associated high mortality and morbidity.
[0008] For these reasons, it would be desirable to provide alternative and additional methods, devices, and systems for performing the repair of mitral and other cardiac valves. Such methods, devices, and systems should preferably not require open chest access and be capable of being performed either endovascularly, i.e., using devices which are advanced to the heart from a point in the patient's vasculature remote from the heart or by a minimally invasive approach. Further, such devices and systems should provide features which allow repositioning and optional removal of a fixation device prior to fixation to ensure optimal placement. Still more preferably, the methods, devices, and systems would be useful for repair of tissues in the body other than heart valves. At least some of these objectives will be met by the inventions described hereinbelow.
[0009] 2. Description of the Background Art
[0010] Minimally invasive and percutaneous techniques for coapting and modifying mitral valve leaflets to treat mitral valve regurgitation are described in PCT Publication Nos. WO 98/35638; WO 99/00059; WO 99/01377; and WO 00/03759.
[0011] Maisano et al. (1998) Eur. J. Cardiothorac. Surg. 13:240-246; Fucci et al. (1995) Eur. J. Cardiothorac. Surg. 9:621-627; and Umana et al. (1998) Ann. Thorac. Surg. 66:1640-1646, describe open surgical procedures for performing “edge-to-edge” or “bow-tie” mitral valve repair where edges of the opposed valve leaflets are sutured together to lessen regurgitation. Dec and Fuster (1994) N. Engl. J. Med. 331:1564-1575 and Alvarez et al. (1996) J. Thorac. Cardiovasc. Surg. 112:238-247 are review articles discussing the nature of and treatments for dilated cardiomyopathy.
[0012] Mitral valve annuloplasty is described in the following publications. Bach and Bolling (1996) Am. J. Cardiol. 78:966-969; Kameda et al. (1996) Ann. Thorac. Surg. 61:1829-1832; Bach and Bolling (1995) Am. Heart J. 129:1165-1170; and Bolling et al. (1995) 109:676-683. Linear segmental annuloplasty for mitral valve repair is described in Ricchi et al. (1997) Ann. Thorac. Surg. 63:1805-1806. Tricuspid valve annuloplasty is described in McCarthy and Cosgrove (1997) Ann. Thorac. Surg. 64:267-268; Tager et al. (1998) Am. J. Cardiol. 81:1013-1016; and Abe et al. (1989) Ann. Thorac. Surg. 48:670-676.
[0013] Percutaneous transluminal cardiac repair procedures are described in Park et al. (1978) Circulation 58:600-608; Uchida et al. (1991) Am. Heart J. 121: 1221-1224; and Ali Khan et al. (1991) Cathet. Cardiovasc. Diagn. 23:257-262.
[0014] Endovascular cardiac valve replacement is described in U.S. Pat. Nos. 5,840,081; 5,411,552; 5,554,185; 5,332,402; 4,994,077; and 4,056,854. See also U.S. Pat. No. 3,671,979 which describes a catheter for temporary placement of an artificial heart valve.
[0015] Other percutaneous and endovascular cardiac repair procedures are described in U.S. Pat. Nos. 4,917,089; 4,484,579; and 3,874,338; and PCT Publication No. WO 91/01689.
[0016] Thoracoscopic and other minimally invasive heart valve repair and replacement procedures are described in U.S. Pat. Nos. 5,855,614; 5,829,447; 5,823,956; 5,797,960; 5,769,812; and 5,718,725.
BRIEF SUMMARY OF THE INVENTION
[0017] The invention provides devices, systems and methods for tissue approximation and repair at treatment sites. The devices, systems and methods of the invention will find use in a variety of therapeutic procedures, including endovascular, minimally-invasive, and open surgical procedures, and can be used in various anatomical regions, including the abdomen, thorax, cardiovascular system, heart, intestinal tract, stomach, urinary tract, bladder, lung, and other organs, vessels, and tissues. The invention is particularly useful in those procedures requiring minimally-invasive or endovascular access to remote tissue locations, where the instruments utilized must negotiate long, narrow, and tortuous pathways to the treatment site. In addition, many of the devices and systems of the invention are adapted to be reversible and removable from the patient at any point without interference with or trauma to internal tissues.
[0018] In preferred embodiments, the devices, systems and methods of the invention are adapted for fixation of tissue at a treatment site. Exemplary tissue fixation applications include cardiac valve repair, septal defect repair, vascular ligation and clamping, laceration repair and wound closure, but the invention may find use in a wide variety of tissue approximation and repair procedures. In a particularly preferred embodiment, the devices, systems and methods of the invention are adapted for repair of cardiac valves, and particularly the mitral valve, as a therapy for regurgitation. The invention enables two or more valve leaflets to be coapted using an “edge-to-edge” or “bow-tie” technique to reduce regurgitation, yet does not require open surgery through the chest and heart wall as in conventional approaches. Using the devices, systems and methods of the invention, the mitral valve can be accessed from a remote surgical or vascular access point and the two valve leaflets may be coapted using endovascular or minimally invasive approaches. While less preferred, in some circumstances the invention may also find application in open surgical approaches as well. According to the invention, the mitral valve may be approached either from the atrial side (antegrade approach) or the ventricular side (retrograde approach), and either through blood vessels or through the heart wall.
[0019] The devices, systems and methods of the invention are centered on variety of devices which may be used individually or in a variety of combinations to form interventional systems. In preferred embodiments, the interventional system includes a multi-catheter guiding system, a delivery catheter and an interventional device. Each of these components will be discussed herein.
[0020] In an exemplary embodiment, the invention provides a fixation device having a pair of distal elements (or fixation elements), each distal element having a free end and an engagement surface for engaging the tissue, wherein the distal elements are moveable between a first position for capturing the tissue and a second position for fixing the tissue. Preferably, the engagement surfaces are spaced apart in the first position and are closer together and generally face toward each other in the second position. The fixation device is preferably delivered to a target location in a patient's body by a delivery catheter having an elongated shaft, a proximal end and a distal end, the delivery catheter being configured to be positioned at the target location from a remote access point such as a vascular puncture or cut-down or a surgical penetration. In a preferred embodiment, the target location is a valve in the heart.
[0021] The fixation device is preferably delivered with the distal elements in a delivery position configured to minimize the profile of the device. When approaching the mitral valve from the atrial side, some embodiments of the fixation device allow the device to be delivered with the free ends of the distal elements pointing in a generally proximal direction forming an angle of less than about 90°, preferably less than about 20°, relative to the longitudinal axis of the delivery device shaft. In this position the engagement surfaces are facing generally toward each other, being disposed at an angle of less than about 180°, and preferably less than about 40°, relative to each other. For ventricular approaches, in the delivery position the free ends of the distal elements are pointing in a generally distal direction and form an angle of less than about 90°, preferably less than about 20° relative to the longitudinal axis of the delivery device shaft. In this position, the engagement surfaces are facing generally toward each other, usually being disposed at an angle of less than about 180°, and preferably less than about 90°, relative to each other. Alternatively, in some ventricular approaches, it may be preferred to have the free ends of the fixation elements pointing in a generally proximal direction and the engagement surfaces facing away from each other in the delivery position.
[0022] In order to provide for the reversibility and removability of the devices and systems of the invention, the distal elements preferably are movable to an inverted position that minimizes entanglement and interferences with surrounding tissues should the device be desired to be withdrawn. In mitral repair applications, this is particularly important due to the presence of chordae tendonae, valve leaflets and other tissues with which devices may become entangled. For approaches from the atrial side of the mitral valve, in the inverted position, the free ends will be pointing in a generally distal direction relative to the catheter shaft and the engagement surfaces will be facing generally away from each other, usually being disposed at an angle of more than about 180°, and preferably more than 270°, relative to each other. For ventricular approaches to the valve, in the inverted position the free ends will be pointing in a distal direction relative to the catheter shaft and the engagement surfaces will be facing generally toward each other, usually being disposed at an angle of less than about 180°, and preferably less than 90°, relative to each other.
[0023] In the open position, the engagement surfaces of the distal elements preferably form an angle of up to 180° relative to each other so as to maximize the area in which to capture the valve leaflets or other target tissue. The distal elements are preferably movable to a closed position in which the engagement surfaces engage each other or form an angle as small as 0° relative to each other. The distal elements are configured to be adjusted to and left permanently in any of various positions between the open and closed positions to allow for fixation of tissues of various thickness, geometry, and spacing.
[0024] In a preferred embodiment, the fixation device of the invention will further include at least one proximal element (or gripping element). Each proximal element and distal element will be movable relative to each other and configured to capture tissue between the proximal element and the engagement surface of the distal element. Preferably, the distal elements and proximal elements are independently movable but in some embodiments may be movable with the same mechanism. The proximal element may be preferably biased toward the engagement surface of the fixation element to provide a compressive force against tissue captured therebetween.
[0025] In another aspect, the invention provides a fixation device for engaging tissue comprising a coupling member configured for coupling a catheter and a pair of distal elements connected to the coupling member, each distal element having an engagement surface for engaging the tissue. The distal elements are moveable between an open position wherein the distal elements extend radially outwardly facing the engagement surfaces toward a first direction, and an inverted position wherein the distal elements have rotated away from the first direction facing the engagement surfaces radially outwardly.
[0026] In a further aspect, the distal elements of the invention are adapted to receive a suture passed through the target tissue. For example, implant pledgets may be detachably mounted to the distal elements so as to be positionable against a surface of tissue engaged by the distal elements. A suture may then be passed through the tissue and implant pledget, which are supported by the distal element. The implant pledgets are then detached from the distal elements, which may be withdrawn from the site, and the suture is tensioned and secured to the target tissue. The delivery catheter, in this embodiment, will further include a movable fixation tool or penetration element for penetrating the target tissue and the implant pledget. A suture is coupled to the penetration element and preferably an anchor is attached to the suture. The penetration element is movable relative to the catheter to penetrate the target tissue and the implant pledget, bringing with it the suture and anchor. The anchor is configured to deploy into an expanded configuration so as to securely engage the implant pledget opposite the target tissue, retaining the suture therein. For the mitral valve, an implant pledget and suture may be similarly deployed in both leaflets, and the sutures secured to one another to coapt the leaflets. Thus, in this embodiment, the distal elements are used to deliver implant pledgets and secure them to the target tissue, but are not themselves deployed at the site as in other embodiments. However, following deployment of the implant pledgets and associated sutures, the distal elements must be withdrawn from the body. For this purpose, the distal elements are movable to an inverted position like the embodiments described above to facilitate withdrawing the device without interference or injury to surrounding tissues.
[0027] In some applications such as the repair of the mitral valve, the fixation device is adapted to be detached from the delivery catheter and left permanently in the patient. In such applications, it is often desirable to promote tissue growth around the fixation device. For this purpose, some or all of the components of the fixation device are preferably covered with a covering or coating to promote tissue growth. In one embodiment, a biocompatible fabric cover is positioned over the distal elements and/or the proximal elements. The cover may optionally be impregnated or coated with various therapeutic agents, including tissue growth promoters, antibiotics, anti-clotting, blood thinning, and other agents. Alternatively or in addition, some or all of the fixation element and/or covering may be comprised of a bioerodable, biodegradable or bioabsorbable material so that it may degrade or be absorbed by the body after the repaired tissues have grown together.
[0028] The distal elements and proximal elements will be configured to provide high retention force so that the fixation device remains securely fastened to the target tissue throughout the cardiac cycle. At the same time, the distal and proximal elements will be configured to minimize trauma to the tissue engaged by them. This allows the fixation device to be removed from the tissue after initial application without creating clinically significant injury to the tissue. In order to enhance retention without creating significant trauma, the proximal elements and/or the distal elements may have friction-enhancing features on their surfaces that engage the target tissue. Such friction-enhancing features may include barbs, bumps, grooves, openings, channels, surface roughening, coverings, and coatings, among others. Optionally, magnets may be present in the proximal and/or distal elements. Preferably the friction-enhancing features and the magnets will be configured to increase the retention force of the distal and proximal elements on the tissue, while not leaving significant injury or scarring if the device is removed.
[0029] The distal and proximal elements may further have a shape and flexibility to maximize retention force and minimize trauma to the target tissue. In a preferred embodiment, the engagement surfaces of the distal elements have a concave shape configured to allow the proximal elements, along with the target tissue, to be nested or recessed within the distal elements. This increases the surface area of the tissue engaged by the distal elements and creates a geometry of tissue engagement that has a higher retention force than a planar engagement surface. To minimize trauma, the longitudinal edges as well as the free ends of the distal elements are preferably curved outwardly away from the engagement surface so that these edges present a rounded surface against the target tissue. The distal elements and/or the proximal elements may also be flexible so that they deflect to some degree in response to forces against the tissue engaged thereby, reducing the chances that the tissue will tear or bruise in response to such forces.
[0030] The fixation device will include an actuation mechanism for moving the distal elements between the open, closed, and inverted positions. A variety of actuation mechanisms may be used. In an exemplary embodiment, a coupling member connects the fixation device to the delivery catheter, and a stud is slidably coupled to the coupling member. In a “push to close/pull to open” embodiment, the distal elements are pivotably coupled to the stud and the actuation mechanism comprises a pair of link members connected between the distal elements and the coupling member, whereby sliding the stud relative to the coupling member pivots the distal elements inwardly or outwardly into the various positions. Alternatively, in a “push to open/pull to close” embodiment, the distal elements are pivotably coupled to the coupling member and the links connected between the distal elements and the stud.
[0031] The fixation device of the invention preferably includes a coupling member that is detachably connectable to the delivery catheter. The coupling member may have various constructions, but in an exemplary embodiment comprises an outer member having an axial channel, the outer member being coupled to one of either the distal elements or the actuation mechanism. An inner member extends slidably through the axial channel and is coupled to the other of either the distal elements or the actuation mechanism. The delivery catheter will be configured to detachably connect to both the inner member and the outer member. In one embodiment, the delivery catheter has a tubular shaft and an actuator rod slidably disposed in the tubular shaft. The junction of the outer member with the tubular shaft comprises a joining line, which may have a variety of shapes including sigmoid curves. The actuator rod extends from the delivery catheter through the axial channel in the outer member to maintain its connection with the tubular shaft. The actuator rod may be connected to the inner member by various connection structures, including threaded connections. By detachment of the actuator rod from the inner member and retraction of the actuator rod back into the tubular shaft, the outer member is released from the tubular shaft to allow deployment of the fixation device.
[0032] In a preferred embodiment, the fixation device further includes a locking mechanism that maintains the distal elements in a selected position relative to each other. Because the ideal degree of closure of the fixation device may not be known until it is actually applied to the target tissue, the locking mechanism is configured to retain the distal elements in position regardless of how open or closed they may be. While a variety of locking mechanisms may be used, in an exemplary embodiment the locking mechanism comprises a wedging element that is movable into frictional engagement with a movable component of the fixation device to prevent further movement of the distal elements. In embodiments utilizing the actuation mechanism described above, the component with which the wedging element engages may be the coupling member or the stud slidably coupled thereto. In one embodiment, the stud passes through an aperture in the coupling member that has a sloping sidewall, and the wedging element comprises a barbell disposed between the sidewall and the stud.
[0033] The fixation device preferably also includes an unlocking mechanism for releasing the locking mechanism, allowing the distal elements and proximal elements to move. In one embodiment, the unlocking mechanism comprises a harness coupled to the wedging element of the locking mechanism to reduce frictional engagement with the movable component of the fixation device. In an exemplary embodiment, the harness is slidably coupled to the coupling member and extends around the wedging element of the locking mechanism, whereby the harness can be retracted relative to the coupling member to disengage the wedging element from the stud.
[0034] In a further aspect, the invention provides an interventional system comprising a tubular guide having a proximal end, a distal end and a channel therebetween, the distal end of the tubular guide being deflectable about a first axis; a delivery catheter positionable through the channel, the delivery catheter having a flexible shaft with a proximal end, a distal end, a lumen therebetween, and an actuation element movably disposed in the lumen; and a fixation device having a coupling member releasably coupled to the distal end of the shaft, a first distal element movably coupled to the coupling member, and a first proximal element movable relative to the distal element, the first distal element being releasably coupled to the actuation element and movable therewith, the first distal element and the first proximal element being adapted to engage tissue therebetween.
[0035] The delivery device of the invention is adapted to allow the user to deliver the fixation device to the target site from a remote access point, whether through endovascular or surgical approaches, align the device with the target tissue, and to selectively close, open, invert, lock or unlock the distal element. In some embodiments, the delivery device will have a highly flexible, kink resistant, torsionally stiff shaft with minimal elongation and high compressive strength. The delivery device will also have the movable components and associated actuators to move the distal elements between the open, closed, and inverted positions, to move the proximal elements into engagement with the target tissue, to unlock the locking mechanism, and to detach the distal element from the delivery catheter. In a preferred embodiment, the delivery device comprises a delivery catheter having an elongated shaft which has an inner lumen. The distal end of the shaft is configured for detachable connection to the coupling member of the fixation device. An actuator rod is slidably disposed in the inner lumen and is adapted for detachable coupling to the stud or other component of the fixation device that moves the distal elements. A plurality of tubular guides, preferably in the form of metallic or polymeric coils, extend through the inner lumen of the shaft and are typically fixed to the shaft near its proximal and distal ends but are unrestrained therebetween, providing a highly flexible and kink-resistant construction. Lines for actuating the proximal elements and the unlocking mechanism of the fixation device extend through these tubular guides and are detachably coupled to the proximal element and unlocking mechanisms. These and other aspects of delivery catheters suitable for use in the present invention are described in copending application Ser. No. 10/441,687, Attorney Docket No. 020489-001700US, filed on the same day as the present application, which has been incorporated herein by reference.
[0036] The delivery catheter may additionally include a tether that is detachably coupled to a portion of the fixation device for purposes of retrieval of the device following detachment from the delivery catheter. The tether may be a separate flexible filament extending from the delivery catheter to the fixation device, but alternatively may be a line coupled to either the unlocking mechanism or the proximal element and used also for actuating those components. In either case, the tether will be detachable from the fixation device so that it may be detached once the device has been deployed successfully.
[0037] The system of the invention may additionally include a guide that facilitates introduction and navigation of the delivery catheter and fixation device to the target location. The guide is preferably tubular with a channel extending between its proximal and distal ends in which the delivery catheter and fixation device may be slidably positioned. The distal end of the guide is steerable, usually being deflectable about at least one axis, and preferably about two axes. The guide will have a size, material, flexibility and other characteristics suitable for the application in which it is being used. For mitral valve repair, the guide is preferably configured to be introduced in a femoral vein and advanced through the inferior vena cava into the heart, across a penetration in the interatrial septum, and into alignment with the mitral valve in the left atrium. Alternatively, the guide may be configured for introduction in a femoral, axillary, or brachiocephalic artery and advancement through the aorta and aortic valve into the ventricle where it is steered into alignment with the mitral valve. In a further alternative, the guide may be configured for introduction through a puncture or incision in the chest wall and through an incision in the wall of the heart to approach the mitral valve.
[0038] In an exemplary embodiment, the guide comprises a multi-catheter guiding system which has two components, including an inner tubular member or inner guide catheter and an outer tubular member or outer guide catheter. The inner tubular member has a distal end deflectable about a first axis. The outer tubular member has a distal end deflectable about a second axis. Further, the inner tubular member may be rotatable relative to the outer tubular member about its longitudinal axis. Mobility in additional directions and about additional axes may optionally be provided. Additional aspects of guides usable in the system of the invention are described in pending application Ser. No. 10/441,508, Attorney Docket No. 020489-001500US, which has been incorporated herein by reference.
[0039] The invention further provides methods of performing therapeutic interventions at a tissue site. In one embodiment, the method includes the steps of advancing an interventional tool having a proximal end, a distal end and a fixation device near the distal end to a location within a patient's body, wherein the fixation device includes a pair of distal elements each having a free end and an engagement surface; moving the distal elements to an open position wherein the free ends are spaced apart; positioning the distal elements such that the engagement surfaces engage tissue at the tissue site; and detaching the fixation device from the interventional tool. Preferably, the method further includes the step of inverting the distal elements to an inverted position wherein the free ends point generally in a distal direction. In some embodiments, the engagement surfaces will face generally away from each other in the inverted position, while in other embodiments, the engagement surfaces will face generally toward each other in the inverted position.
[0040] In an exemplary embodiment, the tissue site comprises first and second leaflets, and the step of moving the distal elements comprises coapting the leaflets. The leaflets may be part of a variety of tissue structures, but are preferably part of a cardiac valve such as the mitral valve. In antegrade approaches, the step of advancing will usually include inserting the fixation device through a valve annulus, e.g. from an atrium of the heart to a ventricle of the heart. In such approaches, the method may further include a step of withdrawing the fixation device through the valve annulus with the fixation device in the inverted position. Retrograde approaches are also provided, in which the step of advancing will include the step of passing the fixation device through a ventricle of the heart into an atrium of the heart. The step of advancing may further comprise transluminally positioning the fixation device through a blood vessel into the heart, and may include inserting the fixation device through an interatrial septum of the heart. Alternatively, the step of advancing may comprise inserting the device through a surgical penetration in a body wall.
[0041] The method may further include moving the distal elements to a closed position after the step of positioning, the free ends of the distal element being closer together in the closed position with the engagement surfaces facing generally toward each other. In addition, the method may include a step of deploying a proximal element on the fixation device toward each engagement surface to as to capture tissue therebetween. Before the step of inverting, the proximal elements are retracted away from the engagement surfaces. The method optionally includes a step of locking the distal elements in a desired position, and may further include a step of unlocking the distal elements so that they are movable again.
[0042] In a further aspect, a method according to the invention comprises advancing a catheter having a proximal end, a distal end and a fixation device near the distal end to a location within a body, wherein the fixation device includes a pair of distal elements each having an engagement surface; moving the distal elements to an open position wherein the distal elements extend radially outwardly facing the engagement surfaces toward a direction other than radially outwardly; and moving the distal elements to an inverted position wherein the engagement surfaces face radially outwardly.
[0043] In still another aspect, the invention provides a method for fixing tissues together comprising advancing a catheter having a proximal end, a distal end and a fixation device disposed near the distal end to a location near the tissues, wherein the fixation device includes a pair of distal elements each having a removable implant pledget; moving the distal elements so that each implant pledget engages one of the tissues; penetrating each tissue and engaged implant pledget and passing a tie therethrough; fastening the ties to fix the tissues together; and removing the fixation device leaving the implant pledget in place.
[0044] In an additional aspect of the invention, kits for performing an intervention at a tissue site in a patient's body include a fixation device and Instructions for Use setting forth the steps of using the fixation device according to the methods of the invention. The fixation device may be as described in any of the various examples set forth herein. The kits may further include a delivery tool or catheter for delivering the fixation device to the tissue site, as well as a tubular guide through which the delivery tool or catheter may be positioned.
[0045] Other aspects of the nature and advantages of the invention are set forth in the detailed description set forth below, taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 illustrates the left ventricle and left atrium of the heart during systole.
[0047] FIG. 2A illustrates free edges of leaflets in normal coaptation, and FIG. 2B illustrates the free edges in regurgitative coaptation.
[0048] FIG. 3A-3C illustrate grasping of the leaflets with a fixation device, inversion of the distal elements of the fixation device and removal of the fixation device, respectively.
[0049] FIG. 4 illustrates the position of the fixation device in a desired orientation relative to the leaflets.
[0050] FIGS. 5A-5B , 6 A- 6 B illustrate exemplary embodiments of coupling mechanisms of the instant application.
[0051] FIGS. 7A-7D illustrate an embodiment of a fixation device in various positions.
[0052] FIGS. 8A-8B illustrate an embodiment of the fixation device wherein some or all of the components are molded as one part.
[0053] FIG. 9 illustrates another embodiment of the fixation device of the present invention.
[0054] FIGS. 10A-10B , 11 A- 11 B, 12 A- 12 B, 13 A- 13 B, 14 - 16 illustrate embodiments of a fixation device in various possible positions during introduction and placement of the device within the body to perform a therapeutic procedure.
[0055] FIGS. 17A-17C illustrate a covering on the fixation device wherein the device is in various positions.
[0056] FIG. 18 illustrates an embodiment of the fixation device including proximal elements and a locking mechanism.
[0057] FIG. 19 provides a cross-sectional view of the locking mechanism of FIG. 18 .
[0058] FIGS. 20-21 provide a cross-sectional view of the locking mechanism in the unlocked and locked positions respectively.
[0059] FIGS. 22A-22B illustrate a variation of the fixation device to facilitate capture of more widely-separated leaflets or other tissue flaps.
[0060] FIGS. 23 , 24 A- 24 B illustrate another embodiment of a locking mechanism.
[0061] FIGS. 25 , 26 A- 26 B illustrate yet another embodiment of a locking mechanism.
[0062] FIGS. 27-28 illustrate an additional embodiment of the fixation device wherein separation of couplers rotate the distal elements around pins.
[0063] FIGS. 29-30 illustrate the fixation device of FIGS. 27-28 with additional features such as barbs and bumpers.
[0064] FIG. 31 illustrates an embodiment of the fixation device having engagement surfaces with a serrated edge and wherein the fixation device is mounted for a ventricular approach to a mitral valve.
[0065] FIGS. 32-34 illustrate an additional embodiment of the fixation device which allows tissue to be grasped between the distal elements and the proximal elements while in an arrangement wherein the distal elements are parallel to each other.
[0066] FIGS. 35-39 , 40 A- 40 D, 41 - 42 , 43 A- 43 C illustrate another embodiment of the fixation device wherein the fixation device includes distal elements having implant pledgets.
[0067] FIGS. 44A-44B , 45 - 46 illustrate another embodiment of the fixation device wherein the distal elements are comprised of a semi-rigid material having a folded shape.
[0068] FIG. 47 is a perspective view of an embodiment of a delivery catheter for a fixation device.
[0069] FIG. 48 illustrates an embodiment of a fixation device coupled to the distal end of a delivery catheter.
[0070] FIG. 49 illustrates a portion of the shaft of a delivery catheter and a fixation device which is coupleable with the catheter.
[0071] FIGS. 50-52 are cross-sectional views of embodiments of the shaft of the delivery catheter.
[0072] FIGS. 52A-52B illustrate embodiments of the nose of the shaft of the delivery catheter.
[0073] FIG. 53A-53C illustrate various arrangements of lock lines engaging release harnesses of a locking mechanism.
[0074] FIGS. 54A-54B illustrate various arrangements of proximal element lines engaging proximal elements of a fixation device.
[0075] FIG. 55 illustrates an embodiment of the handle of the delivery catheter.
[0076] FIG. 56 is a cross-sectional view of the main body of the handle.
[0077] FIG. 57 illustrates an embodiment of a lock line handle.
[0078] FIG. 57A illustrates the lock line handle of FIG. 57 positioned within a semi-tube which is disposed within the sealed chamber.
[0079] FIGS. 58A-58B illustrate a mechanism for applying tension to lock lines.
[0080] FIGS. 59 , 59 A- 59 B illustrate features of the actuator rod control and handle.
[0081] FIG. 60 is a perspective view of an embodiment of a multi-catheter guiding system of the present invention, and an interventional catheter positioned therethrough.
[0082] FIG. 61A illustrates a primary curvature in an outer guide catheter.
[0083] FIG. 61B illustrates a secondary curvature in an inner guide catheter.
[0084] FIGS. 61C-61D illustrate example movement of an inner guide catheter through angle thetas.
[0085] FIG. 62A is a perspective side view of a multi-catheter guiding system having an additional curve in the outer guide catheter.
[0086] FIG. 62B illustrates lifting of the outer guide catheter due to the additional curve of FIG. 62A .
[0087] FIGS. 63A-63D illustrate a method of using the multi-catheter guiding system for accessing the mitral valve.
[0088] FIGS. 64A-64D illustrate curvature of a guide catheter of the present invention by the actuation of one or more pullwires.
[0089] FIG. 64E illustrates attachment of a pullwire to a tip ring.
[0090] FIGS. 65A-651 illustrate embodiments of the present invention comprising sections constructed with the inclusion of braiding or coil.
[0091] FIGS. 66A-66C illustrate a keying feature of the present invention.
[0092] FIGS. 67A-67B are perspective views of a guide catheter including a series of articulating members.
[0093] FIG. 68 illustrates embodiments of the handles.
[0094] FIG. 69 illustrates the handles of FIG. 68 with a portion of the housing removed.
[0095] FIG. 70 illustrates steering mechanisms within a handle.
[0096] FIG. 71 illustrates attachment of a pullwire to a disk.
[0097] FIGS. 72A-72B illustrate a hard stop peg restricting rotation of a disk.
[0098] FIGS. 73A-73C illustrates a portion of a hard stop gear assembly.
[0099] FIGS. 74A-74F illustrate a ball restricting rotation of a disk.
[0100] FIG. 75 illustrates an embodiment of a friction assembly.
[0101] FIG. 76 illustrates an embodiment of an interventional system of the present invention.
[0102] FIG. 76A illustrates an embodiment of a hemostatic valve for use with the present invention.
[0103] FIG. 76B illustrates an embodiment of a fixation device introducer.
[0104] FIG. 77 illustrates another embodiment of an interventional system of the present invention.
[0105] FIGS. 78-80 illustrate an embodiment of a stabilizer base for use with the present invention.
[0106] FIG. 81 illustrates a kit constructed in accordance with the principles of the present invention
DETAILED DESCRIPTION OF THE INVENTION
I. Cardiac Physiology
[0107] The left ventricle LV of a normal heart H in systole is illustrated in FIG. 1 . The left ventricle LV is contracting and blood flows outwardly through the tricuspid (aortic) valve AV in the direction of the arrows. Back flow of blood or “regurgitation” through the mitral valve MV is prevented since the mitral valve is configured as a “check valve” which prevents back flow when pressure in the left ventricle is higher than that in the left atrium LA. The mitral valve MV comprises a pair of leaflets having free edges FE which meet evenly to close, as illustrated in FIG. 1 . The opposite ends of the leaflets LF are attached to the surrounding heart structure along an annular region referred to as the annulus AN. The free edges FE of the leaflets LF are secured to the lower portions of the left ventricle LV through chordae tendinae CT (referred to hereinafter as the chordae) which include plurality of branching tendons secured over the lower surfaces of each of the valve leaflets LF. The chordae CT in turn, are attached to the papillary muscles PM which extend upwardly from the lower portions of the left ventricle and intraventricular septum IVS.
[0108] A number of structural defects in the heart can cause mitral valve regurgitation. Regurgitation occurs when the valve leaflets do not close properly allowing leakage from the ventricle into the atrium. As shown in FIG. 2A , the free edges of the anterior and posterior leaflets normally meet along a line of coaptation C. An example of a defect causing regurgitation is shown in FIG. 2B . Here an enlargement of the heart causes the mitral annulus to become enlarged, making it impossible for the free edges FE to meet during systole. This results in a gap G which allows blood to leak through the valve during ventricular systole. Ruptured or elongated chordae can also cause a valve leaflet to prolapse since inadequate tension is transmitted to the leaflet via the chordae. While the other leaflet maintains a normal profile, the two valve leaflets do not properly meet and leakage from the left ventricle into the left atrium will occur. Such regurgitation can also occur in patients who have suffered ischemic heart disease where the left ventricle does not contract sufficiently to effect proper closure.
II. General Overview
[0109] The present invention provides methods and devices for grasping, approximating and fixating tissues such as valve leaflets to treat cardiac valve regurgitation, particularly mitral valve regurgitation. The present invention also provides features that allow repositioning and removal of the device if so desired, particularly in areas where removal may be hindered by anatomical features such as chordae CT. Such removal would allow the surgeon to reapproach the valve in a new manner if so desired.
[0110] Grasping will preferably be atraumatic providing a number of benefits. By atraumatic, it is meant that the devices and methods of the invention may be applied to the valve leaflets and then removed without causing any significant clinical impairment of leaflet structure or function. The leaflets and valve continue to function substantially the same as before the invention was applied. Thus, some minor penetration or denting of the leaflets may occur using the invention while still meeting the definition of “atraumatic”. This enables the devices of the invention to be applied to a diseased valve and, if desired, removed or repositioned without having negatively affected valve function. In addition, it will be understood that in some cases it may be necessary or desirable to pierce or otherwise permanently affect the leaflets during either grasping, fixing or both. In some of these cases, grasping and fixation may be accomplished by a single device. Although a number of embodiments are provided to achieve these results, a general overview of the basic features will be presented herein. Such features are not intended to limit the scope of the invention and are presented with the aim of providing a basis for descriptions of individual embodiments presented later in the application.
[0111] The devices and methods of the invention rely upon the use of an interventional tool that is positioned near a desired treatment site and used to grasp the target tissue. In endovascular applications, the interventional tool is typically an interventional catheter. In surgical applications, the interventional tool is typically an interventional instrument. In preferred embodiments, fixation of the grasped tissue is accomplished by maintaining grasping with a portion of the interventional tool which is left behind as an implant. While the invention may have a variety of applications for tissue approximation and fixation throughout the body, it is particularly well adapted for the repair of valves, especially cardiac valves such as the mitral valve. Referring to FIG. 3A , an interventional tool 10 , having a delivery device, such as a shaft 12 , and a fixation device 14 , is illustrated having approached the mitral valve MV from the atrial side and grasped the leaflets LF. The mitral valve may be accessed either surgically or by using endovascular techniques, and either by a retrograde approach through the ventricle or by an antegrade approach through the atrium, as described above. For illustration purposes, an antegrade approach is described.
[0112] The fixation device 14 is releasably attached to the shaft 12 of the interventional tool 10 at its distal end. When describing the devices of the invention herein, “proximal” shall mean the direction toward the end of the device to be manipulated by the user outside the patient's body, and “distal” shall mean the direction toward the working end of the device that is positioned at the treatment site and away from the user. With respect to the mitral valve, proximal shall refer to the atrial or upstream side of the valve leaflets and distal shall refer to the ventricular or downstream side of the valve leaflets.
[0113] The fixation device 14 typically comprises proximal elements 16 (or gripping elements) and distal elements 18 (or fixation elements) which protrude radially outward and are positionable on opposite sides of the leaflets LF as shown so as to capture or retain the leaflets therebetween. The proximal elements 16 are preferably comprised of cobalt chromium, nitinol or stainless steel, and the distal elements 18 are preferably comprised of cobalt chromium or stainless steel, however any suitable materials may be used. The fixation device 14 is coupleable to the shaft 12 by a coupling mechanism 17 . The coupling mechanism 17 allows the fixation device 14 to detach and be left behind as an implant to hold the leaflets together in the coapted position.
[0114] In some situations, it may be desired to reposition or remove the fixation device 14 after the proximal elements 16 , distal elements 18 , or both have been deployed to capture the leaflets LF. Such repositioning or removal may be desired for a variety of reasons, such as to reapproach the valve in an attempt to achieve better valve function, more optimal positioning of the device 14 on the leaflets, better purchase on the leaflets, to detangle the device 14 from surrounding tissue such as chordae, to exchange the device 14 with one having a different design, or to abort the fixation procedure, to name a few. To facilitate repositioning or removal of the fixation device 14 the distal elements 18 are releasable and optionally invertible to a configuration suitable for withdrawal of the device 14 from the valve without tangling or interfering with or damaging the chordae, leaflets or other tissue. FIG. 3B illustrates inversion wherein the distal elements 18 are moveable in the direction of arrows 40 to an inverted position. Likewise, the proximal elements 16 may be raised, if desired. In the inverted position, the device 14 may be repositioned to a desired orientation wherein the distal elements may then be reverted to a grasping position against the leaflets as in FIG. 3A . Alternatively, the fixation device 14 may be withdrawn (indicated by arrow 42 ) from the leaflets as shown in FIG. 3C . Such inversion reduces trauma to the leaflets and minimizes any entanglement of the device with surrounding tissues. Once the device 14 has been withdrawn through the valve leaflets, the proximal and distal elements may be moved to a closed position or configuration suitable for removal from the body or for reinsertion through the mitral valve.
[0115] FIG. 4 illustrates the position of the fixation device 14 in a desired orientation in relation to the leaflets LF. This is a short-axis view of the mitral valve MV from the atrial side, therefore, the proximal elements 16 are shown in solid line and the distal elements 18 are shown in dashed line. The proximal and distal elements 16 , 18 are positioned to be substantially perpendicular to the line of coaptation C. The device 14 may be moved roughly along the line of coaptation to the location of regurgitation. The leaflets LF are held in place so that during diastole, as shown in FIG. 4 , the leaflets LF remain in position between the elements 16 , 18 surrounded by openings O which result from the diastolic pressure gradient. Advantageously, leaflets LF are coapted such that their proximal or upstream surfaces are facing each other in a vertical orientation, parallel to the direction of blood flow through mitral valve MV. The upstream surfaces may be brought together so as to be in contact with one another or may be held slightly apart, but will preferably be maintained in the vertical orientation in which the upstream surfaces face each other at the point of coaptation. This simulates the double orifice geometry of a standard surgical bow-tie repair. Color Doppler echo will show if the regurgitation of the valve has been reduced. If the resulting mitral flow pattern is satisfactory, the leaflets may be fixed together in this orientation. If the resulting color Doppler image shows insufficient improvement in mitral regurgitation, the interventional tool 10 may be repositioned. This may be repeated until an optimal result is produced wherein the leaflets LF are held in place.
[0116] Once the leaflets are coapted in the desired arrangement, the fixation device 14 is then detached from the shaft 12 and left behind as an implant to hold the leaflets together in the coapted position. As mentioned previously, the fixation device 14 is coupled to the shaft 12 by a coupling mechanism 17 . FIGS. 5A-5B , 6 A- 6 B illustrate exemplary embodiments of such coupling mechanisms. FIG. 5A shows an upper shaft 20 and a detachable lower shaft 22 which are interlocked at a joining line or mating surface 24 . The mating surface 24 may have any shape or curvature which will allow or facilitate interlocking and later detachment. A snuggly fitting outer sheath 26 is positioned over the shafts 20 , 22 to cover the mating surface 24 as shown. FIG. 5B illustrates detachment of the lower shaft 22 from the upper shaft 20 . This is achieved by retracting the outer sheath 26 , so that the mating surface 24 is exposed, which allows the shafts 20 , 22 to separate.
[0117] Similarly, FIG. 6A illustrates a tubular upper shaft 28 and a detachable tubular lower shaft 30 which are interlocked at a mating surface 32 . Again, the mating surface 32 may have any shape or curvature which will allow or facilitate interlocking and later detachment. The tubular upper shaft 28 and tubular lower shaft 30 form an outer member having an axial channel. A snuggly fitting rod 34 or inner member is inserted through the tubular shafts 28 , 30 to bridge the mating surface 32 as shown. FIG. 6B illustrates detachment of the lower shaft 30 from the upper shaft 28 . This is achieved by retracting the rod 34 to a position above the mating surface 32 which in turn allows the shafts 28 , 30 to separate. Other examples of coupling mechanisms are described and illustrated in commonly assigned U.S. Pat. No. 6,752,813 (Attorney Docket No. 020489-000400US), incorporated herein by reference for all purposes.
[0118] In a preferred embodiment, mating surface 24 (or mating surface 32 ) is a sigmoid curve defining a male element and female element on upper shaft 20 (or upper shaft 28 ) which interlock respectively with corresponding female and male elements on lower shaft 22 (or lower shaft 30 ). Typically, the lower shaft is the coupling mechanism 17 of the fixation device 14 . Therefore, the shape of the mating surface selected will preferably provide at least some mating surfaces transverse to the axial axis of the a mechanism 19 to facilitate application of compressive and tensile forces through the coupling mechanism 17 to the fixation device 14 , yet causing minimal interference when the fixation device 14 is to be released from the upper shaft.
III. Fixation Device
[0119] A. Introduction and Placement of Fixation Device
[0120] The fixation device 14 is delivered to the valve or the desired tissues with the use of a delivery device. The delivery device may be rigid or flexible depending on the application. For endovascular applications, the delivery device comprises a flexible delivery catheter which will be described in later sections. Typically, however, such a catheter comprises a shaft, having a proximal end and a distal end, and a fixation device releasably attached to its distal end. The shaft is usually elongate and flexible, suitable for intravascular introduction. Alternatively, the delivery device may comprise a shorter and less flexible interventional instrument which may be used for trans-thoracic surgical introduction through the wall of the heart, although some flexibility and a minimal profile will generally be desirable. A fixation device is releasably coupleable with the delivery device as illustrated in FIG. 3A . The fixation device may have a variety of forms, a few embodiments of which will be described herein.
[0121] FIGS. 7A-7D illustrate an embodiment of a fixation device 14 in various positions or configurations. FIG. 7A illustrates the fixation device 14 in a closed configuration for delivery through the patient's vasculature and, in this example, through the mitral valve. The fixation device 14 includes a coupling member 19 which allows detachment of the fixation device 14 for implantation. In this example, the coupling member 19 is shown to include the lower shaft 22 and mating surface 24 of FIGS. 5A-5B , and therefore the coupling member 19 would function similarly as described above. The fixation device 14 also includes a pair of opposed distal elements 18 , each distal element 18 having an engagement surface 50 facing inwardly toward the opposed distal element 18 in the closed configuration. Distal elements 18 preferably comprise elongate arms 53 , each arm having a proximal end 52 rotatably connected to the coupling member 19 and a free end 54 . Suitable connections for arms 53 to coupling member 19 include pins, living hinges, or other known rotational connection mechanisms. In the closed configuration of FIG. 7A , free ends 54 point in a first direction such that the arms 53 and engagement surfaces 50 are nearly parallel to each other and to an axis 21 , and preferably are angled slightly inwardly toward each other. In a preferred embodiment, when tissue is not present between arms 53 , the arms 53 may be closed until free ends 54 either touch each other or engage shaft 12 when fixation device 14 is attached thereto, thereby minimizing the profile of the fixation device 14 for passage through a delivery device.
[0122] FIGS. 7B-7C illustrate the fixation device 14 in an open position wherein the engagement surfaces 50 are disposed at a separation angle 56 apart, wherein the separation angle 56 is typically up to approximately 180 degrees, preferably up to 90-180 degrees, and arms 53 are disposed generally symmetrically relative to axis 21 . The arms 53 may be moveable to the open position by a variety of actuation mechanisms. For example, a plunger or actuator rod may be advanced through the coupling member 19 , as indicated by arrow 62 , so as to engage a spring or spring loaded actuation mechanism 58 which is attached to the distal elements 18 . By exerting a force against the actuation mechanism 58 , the distal elements 18 are rotated relative to coupling member 19 . The distal elements 18 may be held in this open position by the actuator rod against the resistance provided by the spring of the actuation mechanism 58 which biases the distal elements 18 toward the closed position of FIG. 7A when the distal elements 18 are less than 180 degrees apart. The spring loading of the actuation mechanism 58 resists outward movement of the actuation mechanism 58 and urges the device 14 towards the closed position.
[0123] In this embodiment, proximal elements 16 comprise resilient loop-shaped wire forms biased outwardly and attached to the coupling member 19 so as to be biased to an open position shown in FIG. 7C but moveable rotationally inwardly when arms 53 are closed. The wire forms may be flexible enough to be rigidly attached to coupling member 19 and resiliently deflectable inwardly, or they may be attached by a rotational coupling such as a pin or living hinge. In use, leaflets LF are positioned between the proximal elements 16 and distal elements 18 . Once, the leaflets LF are positioned between the proximal and distal elements 16 , 18 , the distal elements 18 may be closed, compressing the leaflets between engagement surfaces 50 and proximal elements 18 . Depending upon the thickness of the leaflets, the arrangements of the leaflets, the position of the fixation device on the leaflets and other factors, the arms 53 may be maintained in the open position of FIG. 7B , moved to the fully closed position of FIG. 7A , or placed in any of various positions in between so as to coapt the leaflets LF and hold them in the desired position with the desired degree of force. In any case, the fixation device 14 will remain in place as an implant following detachment from the delivery catheter.
[0124] In some situations, as previously mentioned, it may be desirable to reopen the fixation device 14 following initial placement. To reopen the device 14 , the actuator rod may be readvanced or reinserted through the coupling member 19 and readvanced to press against the actuation mechanism 58 , as previously indicated by arrow 62 in FIG. 7B . Again, such advancement applies a force against the actuation mechanism 58 in the manner described above thus moving arms 53 outwardly to release force against leaflets and move engagement surfaces 50 away from proximal elements 16 . The leaflets are then free to move relative to fixation device 14 . The fixation device 14 may then be repositioned as desired and the actuator rod retracted to reclose the distal elements 18 to coapt the leaflets.
[0125] Under some circumstances, it may be further desirable to withdraw the fixation device 14 back through the valve or completely from the patient following initial insertion through the valve. Should this be attempted with the clip in the closed or open positions illustrated in FIGS. 7A-7C , there may be a risk that arms 53 could interfere or become entangled with the chordae, leaflets or other tissues. To avoid this, the fixation element 14 is preferably adapted for inversion of arms 53 so that free ends 54 point in a second direction, opposite to the first direction in which the free ends 54 pointed in the closed position, each arm 53 forming an obtuse angle relative to axis 21 as illustrated in FIG. 7D . The arms 53 may be rotated so that the engagement surfaces 50 are disposed at a separation angle 56 of up to 360 degrees, and preferably at least up to 270 degrees. This may be accomplished by exerting a force against actuation mechanism 58 with a push rod or plunger extending through coupling member 19 as described above. In this embodiment, once the distal elements 18 have rotated beyond 180 degrees apart, the spring loading of the actuation mechanism 58 biases the distal elements 18 toward the inverted position. The spring loading of the actuation mechanism 58 resists outward movement of the actuation mechanism 58 and urges the device 14 towards the inverted position.
[0126] With arms 53 in the inverted position, engagement surfaces 50 provide an atraumatic surface deflect tissues as the fixation device is withdrawn. This allows the device to be retracted back through the valve annulus without risk of injury to valvular and other tissues. In some cases, once the fixation device 14 has been pulled back through the valve, it will be desirable to return the device to the closed position for withdrawal of the device from the body (either through the vasculature or through a surgical opening).
[0127] The embodiment illustrated in FIGS. 7A-7D is assembled from separate components composed of biocompatible materials. The components may be formed from the same or different materials, including but not limited to stainless steel or other metals, Elgiloy®, nitinol, titanium, tantalum, metal alloys or polymers. Additionally, some or all of these components may be made of bioabsorbable materials that will be absorbed by surrounding tissues or will dissolve into the bloodstream following implantation. It has been found that in mitral valve repair applications the fixation devices of the invention are completely surrounded by tissue within a few months of implantation, after which the devices could dissolve or be absorbed without negative impact to the repair.
[0128] In a further embodiment, some or all of the components may be molded as one part, as illustrated in FIGS. 8A-8B . Here, the coupling member 19 , distal elements 18 and actuation mechanism 58 of the fixation device 14 are all molded from a polymer material as one moveable piece. FIG. 8A shows the fixation device 14 in the open position. Advancement of an actuator rod 64 rotates the distal elements 18 relative to the coupling member 19 by a living hinge or by elastic deformation of the plastic at the point of connection between the elements 18 and the coupling member 19 . Typically, this point of connection comprises a thinner segment of polymer to facilitate such bending. Likewise, the actuation mechanism 58 coupled to the distal elements 18 in the same manner. FIG. 8B shows the fixation device 14 in the inverted position.
[0129] FIG. 9 illustrates another embodiment of a fixation device 14 . Here, the fixation device 14 is shown coupled to a shaft 12 to form an interventional tool 10 . The fixation device 14 includes a coupling member 19 and a pair of opposed distal elements 18 . The distal elements 18 comprise elongate arms 53 , each arm having a proximal end 52 rotatably connected to the coupling member 19 and a free end 54 . The free ends 54 have a rounded shape to minimize interference with and trauma to surrounding tissue structures. Preferably, each free end 54 defines a curvature about two axes, one being an axis 66 perpendicular to longitudinal axis of arms 53 . Thus, the engagement surfaces 50 have a cupped or concave shape to surface area in contact with tissue and to assist in grasping and holding the valve leaflets. This further allows arms 53 to nest around the shaft 12 in the closed position to minimize the profile of the device. Preferably, arms 53 are at least partially cupped or curved inwardly about their longitudinal axes 66 . Also, preferably, each free end 54 defines a curvature about an axis 67 perpendicular to axis 66 or the longitudinal axis of arms 53 . This curvature is a reverse curvature along the most distal portion of the free end 54 . Likewise, the longitudinal edges of the free ends 54 may flare outwardly. Both the reverse curvature and flaring minimize trauma to the tissue engaged therewith.
[0130] In a preferred embodiment suitable for mitral valve repair, the transverse width across engagement surfaces 50 (which determines the width of tissue engaged) is at least about 2 mm, usually 3-10 mm, and preferably about 4-6 mm. In some situations, a wider engagement is desired wherein the engagement surfaces 50 are larger, for example about 2 cm, or multiple fixation devices are used adjacent to each other. Arms 53 and engagement surfaces 50 are configured to engage a length of tissue of about 4-10 mm, and preferably about 6-8 mm along the longitudinal axis of arms 53 . Arms 53 further include a plurality of openings to enhance grip and to promote tissue ingrowth following implantation.
[0131] The valve leaflets are grasped between the distal elements 18 and proximal elements 16 . In some embodiments, the proximal elements 16 are flexible, resilient, and cantilevered from coupling member 19 . The proximal elements are preferably resiliently biased toward the distal elements. Each proximal element 16 is shaped and positioned to be at least partially recessed within the concavity of the distal element 18 when no tissue is present. When the fixation device 14 is in the open position, the proximal elements 16 are shaped such that each proximal element 16 is separated from the engagement surface 50 near the proximal end 52 of arm 53 and slopes toward the engagement surface 50 near the free end 54 with the free end of the proximal element contacting engagement surface 50 , as illustrated in FIG. 9 . This shape of the proximal elements 16 accommodates valve leaflets or other tissues of varying thicknesses.
[0132] Proximal elements 16 include a plurality of openings 63 and scalloped side edges 61 to increase grip on tissue. The proximal elements 16 optionally include frictional accessories, frictional features or grip-enhancing elements to assist in grasping and/or holding the leaflets. In preferred embodiments, the frictional accessories comprise barbs 60 having tapering pointed tips extending toward engagement surfaces 50 . It may be appreciated that any suitable frictional accessories may be used, such as prongs, windings, bands, barbs, grooves, channels, bumps, surface roughening, sintering, high-friction pads, coverings, coatings or a combination of these. Optionally, magnets may be present in the proximal and/or distal elements. It may be appreciated that the mating surfaces will be made from or will include material of opposite magnetic charge to cause attraction by magnetic force. For example, the proximal elements and distal elements may each include magnetic material of opposite charge so that tissue is held under constant compression between the proximal and distal elements to facilitate faster healing and ingrowth of tissue. Also, the magnetic force may be used to draw the proximal elements 16 toward the distal elements 18 , in addition to or alternatively to biasing of the proximal elements toward the distal elements. This may assist in deployment of the proximal elements 16 . In another example, the distal elements 18 each include magnetic material of opposite charge so that tissue positioned between the distal elements 18 is held therebetween by magnetic force.
[0133] The proximal elements 16 may be covered with a fabric or other flexible material as described below to enhance grip and tissue ingrowth following implantation. Preferably, when fabrics or coverings are used in combination with barbs or other frictional features, such features will protrude through such fabric or other covering so as to contact any tissue engaged by proximal elements 16 .
[0134] In an exemplary embodiment, proximal elements 16 are formed from metallic sheet of a spring-like material using a stamping operation which creates openings 63 , scalloped edges 61 and barbs 60 . Alternatively, proximal elements 16 could be comprised of a spring-like material or molded from a biocompatible polymer. It should be noted that while some types of frictional accessories that can be used in the present invention may permanently alter or cause some trauma to the tissue engaged thereby, in a preferred embodiment, the frictional accessories will be atraumatic and will not injure or otherwise affect the tissue in a clinically significant way. For example, in the case of barbs 60 , it has been demonstrated that following engagement of mitral valve leaflets by fixation device 14 , should the device later be removed during the procedure barbs 60 leave no significant permanent scarring or other impairment of the leaflet tissue and are thus considered atraumatic.
[0135] The fixation device 14 also includes an actuation mechanism 58 . In this embodiment, the actuation mechanism 58 comprises two link members or legs 68 , each leg 68 having a first end 70 which is rotatably joined with one of the distal elements 18 at a riveted joint 76 and a second end 72 which is rotatably joined with a stud 74 . The legs 68 are preferably comprised of a rigid or semi-rigid metal or polymer such as Elgiloy®, cobalt chromium or stainless steel, however any suitable material may be used. While in the embodiment illustrated both legs 68 are pinned to stud 74 by a single rivet 78 , it may be appreciated, however, that each leg 68 may be individually attached to the stud 74 by a separate rivet or pin. The stud 74 is joinable with an actuator rod 64 (not shown) which extends through the shaft 12 and is axially extendable and retractable to move the stud 74 and therefore the legs 68 which rotate the distal elements 18 between closed, open and inverted positions. Likewise, immobilization of the stud 74 holds the legs 68 in place and therefore holds the distal elements 18 in a desired position. The stud 74 may also be locked in place by a locking feature which will be further described in later sections.
[0136] In any of the embodiments of fixation device 14 disclosed herein, it may be desirable to provide some mobility or flexibility in distal elements 18 and/or proximal elements 16 in the closed position to enable these elements to move or flex with the opening or closing of the valve leaflets. This provides shock absorption and thereby reduces force on the leaflets and minimizes the possibility for tearing or other trauma to the leaflets. Such mobility or flexibility may be provided by using a flexible, resilient metal or polymer of appropriate thickness to construct the distal elements 18 . Also, the locking mechanism of the fixation device (described below) may be constructed of flexible materials to allow some slight movement of the proximal and distal elements even when locked. Further, the distal elements 18 can be connected to the coupling mechanism 19 or to actuation mechanism 58 by a mechanism that biases the distal element into the closed position (inwardly) but permits the arms to open slightly in response to forces exerted by the leaflets. For example, rather than being pinned at a single point, these components may be pinned through a slot that allowed a small amount of translation of the pin in response to forces against the arms. A spring is used to bias the pinned component toward one end of the slot.
[0137] FIGS. 10A-10B , 11 A- 11 B, 12 A- 12 B, 13 A- 13 B, and FIGS. 14-16 illustrate embodiments of the fixation device 14 of FIG. 9 in various possible positions during introduction and placement of the device 14 within the body to perform a therapeutic procedure. FIG. 10A illustrates an embodiment of an interventional tool 10 delivered through a catheter 86 . It may be appreciated that the interventional tool 10 may take the form of a catheter, and likewise, the catheter 86 may take the form of a guide catheter or sheath. However, in this example the terms interventional tool 10 and catheter 86 will be used. The interventional tool 10 comprises a fixation device 14 coupled to a shaft 12 and the fixation device 14 is shown in the closed position. FIG. 10B illustrates a similar embodiment of the fixation device of FIG. 10A in a larger view. In the closed position, the opposed pair of distal elements 18 are positioned so that the engagement surfaces 50 face each other. Each distal element 18 comprises an elongate arm 53 having a cupped or concave shape so that together the arms 53 surround the shaft 12 and optionally contact each other on opposite sides of the shaft. This provides a low profile for the fixation device 14 which is readily passable through the catheter 86 and through any anatomical structures, such as the mitral valve. In addition, FIG. 10B further includes an actuation mechanism 58 . In this embodiment, the actuation mechanism 58 comprises two legs 68 which are each movably coupled to a base 69 . The base 69 is joined with an actuator rod 64 which extends through the shaft 12 and is used to manipulate the fixation device 14 . In some embodiments, the actuator rod 64 attaches directly to the actuation mechanism 58 , particularly the base 69 . However, the actuator rod 64 may alternatively attach to a stud 74 which in turn is attached to the base 69 . In some embodiments, the stud 74 is threaded so that the actuator rod 64 attaches to the stud 74 by a screw-type action. However, the rod 64 and stud 74 may be joined by any mechanism which is releasable to allow the fixation device 14 to be detached from shaft 12 .
[0138] FIGS. 11A-11B illustrate the fixation device 14 in the open position. In the open position, the distal elements 18 are rotated so that the engagement surfaces 50 face a first direction. Distal advancement of the stud 74 relative to coupling member 19 by action of the actuator rod 64 applies force to the distal elements 18 which begin to rotate around joints 76 due to freedom of movement in this direction. Such rotation and movement of the distal elements 18 radially outward causes rotation of the legs 68 about joints 80 so that the legs 68 are directly slightly outwards. The stud 74 may be advanced to any desired distance correlating to a desired separation of the distal elements 18 . In the open position, engagement surfaces 50 are disposed at an acute angle relative to shaft 12 , and are preferably at an angle of between 90 and 180 degrees relative to each other. In one embodiment, in the open position the free ends 54 of arms 53 have a span therebetween of about 10-20 mm, usually about 12-18 mm, and preferably about 14-16 mm.
[0139] Proximal elements 16 are typically biased outwardly toward arms 53 . The proximal elements 16 may be moved inwardly toward the shaft 12 and held against the shaft 12 with the aid of proximal element lines 90 which can be in the form of sutures, wires, nitinol wire, rods, cables, polymeric lines, or other suitable structures. The proximal element lines 90 may be connected with the proximal elements 16 by threading the lines 90 in a variety of ways. When the proximal elements 16 have a loop shape, as shown in FIG. 11A , the line 90 may pass through the loop and double back. When the proximal elements 16 have an elongate solid shape, as shown in FIG. 11B , the line 90 may pass through one or more of the openings 63 in the element 16 . Further, a line loop 48 may be present on a proximal element 16 , also illustrated in FIG. 11B , through which a proximal element line 90 may pass and double back. Such a line loop 48 may be useful to reduce friction on proximal element line 90 or when the proximal elements 16 are solid or devoid of other loops or openings through which the proximal element lines 90 may attach. A proximal element line 90 may attach to the proximal elements 16 by detachable means which would allow a single line 90 to be attached to a proximal element 16 without doubling back and would allow the single line 90 to be detached directly from the proximal element 16 when desired. Examples of such detachable means include hooks, snares, clips or breakable couplings, to name a few. By applying sufficient tension to the proximal element line 90 , the detachable means may be detached from the proximal element 16 such as by breakage of the coupling. Other mechanisms for detachment may also be used. Similarly, a lock line 92 may be attached and detached from a locking mechanism by similar detachable means.
[0140] In the open position, the fixation device 14 can engage the tissue which is to be approximated or treated. The embodiment illustrated in FIGS. 9-11 is adapted for repair of the mitral valve using an antegrade approach from the left atrium. The interventional tool 10 is advanced through the mitral valve from the left atrium to the left ventricle. The distal elements 18 are oriented to be perpendicular to the line of coaptation and then positioned so that the engagement surfaces 50 contact the ventricular surface of the valve leaflets, thereby grasping the leaflets. The proximal elements 16 remain on the atrial side of the valve leaflets so that the leaflets lie between the proximal and distal elements. In this embodiment, the proximal elements 16 have frictional accessories, such as barbs 60 which are directed toward the distal elements 18 . However, neither the proximal elements 16 nor the barbs 60 contact the leaflets at this time.
[0141] The interventional tool 10 may be repeatedly manipulated to reposition the fixation device 14 so that the leaflets are properly contacted or grasped at a desired location. Repositioning is achieved with the fixation device in the open position. In some instances, regurgitation may also be checked while the device 14 is in the open position. If regurgitation is not satisfactorily reduced, the device may be repositioned and regurgitation checked again until the desired results are achieved.
[0142] It may also be desired to invert the fixation device 14 to aid in repositioning or removal of the fixation device 14 . FIGS. 12A-12B illustrate the fixation device 14 in the inverted position. By further advancement of stud 74 relative to coupling member 19 , the distal elements 18 are further rotated so that the engagement surfaces 50 face outwardly and free ends 54 point distally, with each arm 53 forming an obtuse angle relative to shaft 12 . The angle between arms 53 is preferably in the range of about 270 to 360 degrees. Further advancement of the stud 74 further rotates the distal elements 18 around joints 76 . This rotation and movement of the distal elements 18 radially outward causes rotation of the legs 68 about joints 80 so that the legs 68 are returned toward their initial position, generally parallel to each other. The stud 74 may be advanced to any desired distance correlating to a desired inversion of the distal elements 18 . Preferably, in the fully inverted position, the span between free ends 54 is no more than about 20 mm, usually less than about 16 mm, and preferably about 12-14 mm. In this illustration, the proximal elements 16 remain positioned against the shaft 12 by exerting tension on the proximal element lines 90 . Thus, a relatively large space may be created between the elements 16 , 18 for repositioning. In addition, the inverted position allows withdrawal of the fixation device 14 through the valve while minimizing trauma to the leaflets. Engagement surfaces 50 provide an atraumatic surface for deflecting tissue as the fixation device is retracted proximally. It should be further noted that barbs 60 are angled slightly in the distal direction (away from the free ends of the proximal elements 16 ), reducing the risk that the barbs will catch on or lacerate tissue as the fixation device is withdrawn.
[0143] Once the fixation device 14 has been positioned in a desired location against the valve leaflets, the leaflets may then be captured between the proximal elements 16 and the distal elements 18 . FIGS. 13A-13B illustrate the fixation device 14 in such a position. Here, the proximal elements 16 are lowered toward the engagement surfaces 50 so that the leaflets are held therebetween. In FIG. 13B , the proximal elements 16 are shown to include barbs 60 which may be used to provide atraumatic gripping of the leaflets. Alternatively, larger, more sharply pointed barbs or other penetration structures may be used to pierce the leaflets to more actively assist in holding them in place. This position is similar to the open position of FIGS. 11A-11B , however the proximal elements 16 are now lowered toward arms 53 by releasing tension on proximal element lines 90 to compress the leaflet tissue therebetween. At any time, the proximal elements 16 may be raised and the distal elements 18 adjusted or inverted to reposition the fixation device 14 , if regurgitation is not sufficiently reduced.
[0144] After the leaflets have been captured between the proximal and distal elements 16 , 18 in a desired arrangement, the distal elements 18 may be locked to hold the leaflets in this position or the fixation device 14 may be returned to or toward a closed position. Such locking will be described in a later section. FIG. 14 illustrates the fixation device 14 in the closed position wherein the leaflets (not shown) are captured and coapted. This is achieved by retraction of the stud 74 proximally relative to coupling member 19 so that the legs 68 of the actuation mechanism 58 apply an upwards force to the distal elements 18 which in turn rotate the distal elements 18 so that the engagement surfaces 50 again face one another. The released proximal elements 16 which are biased outwardly toward distal elements 18 are concurrently urged inwardly by the distal elements 18 . The fixation device 14 may then be locked to hold the leaflets in this closed position as described below.
[0145] As shown in FIG. 15 , the fixation device 14 may then be released from the shaft 12 . As mentioned, the fixation device 14 is releasably coupleable to the shaft 12 by coupling member 19 . FIG. 15 illustrates the coupling structure, a portion of the shaft 12 to which the coupling member 19 of the fixation device 14 attaches. As shown, the proximal element lines 90 may remain attached to the proximal elements 16 following detachment from shaft 12 to function as a tether to keep the fixation device 14 connected with the catheter 86 . Optionally, a separate tether coupled between shaft 12 and fixation device 14 may be used expressly for this purpose while the proximal element lines 90 are removed. In any case, the repair of the leaflets or tissue may be observed by non-invasive visualization techniques, such as echocardiography, to ensure the desired outcome. If the repair is not desired, the fixation device 14 may be retrieved with the use of the tether or proximal element lines 90 so as to reconnect coupling member 19 with shaft 12 .
[0146] In an exemplary embodiments, proximal element lines 90 are elongated flexible threads, wire, cable, sutures or lines extending through shaft 12 , looped through proximal elements 16 , and extending back through shaft 12 to its proximal end. When detachment is desired, one end of each line may be released at the proximal end of the shaft 12 and the other end pulled to draw the free end of the line distally through shaft 12 and through proximal element 16 thereby releasing the fixation device.
[0147] FIG. 16 illustrates a released fixation device 14 in a closed position. As shown, the coupling member 19 remains separated from the shaft 12 of the interventional tool 10 and the proximal elements 16 are deployed so that tissue (not shown) may reside between the proximal elements 16 and distal elements 18 .
[0148] While the above described embodiments of the invention utilize a push-to-open, pull-to-close mechanism for opening and closing distal elements 18 , it should be understood that a pull-to-open, push-to-close mechanism is equally possible. For example, distal elements 18 may be coupled at their proximal ends to stud 74 rather than to coupling member 19 , and legs 68 may be coupled at their proximal ends to coupling member 19 rather than to stud 74 . In this example, when stud 74 is pushed distally relative to coupling member 19 , distal elements 18 would close, while pulling on stud 74 proximally toward coupling member 19 would open distal elements 18 .
[0149] B. Covering on Fixation Device
[0150] The fixation device 14 may optionally include a covering. The covering may assist in grasping the tissue and may later provide a surface for tissue ingrowth. Ingrowth of the surrounding tissues, such as the valve leaflets, provides stability to the device 14 as it is further anchored in place and may cover the device with native tissue thus reducing the possibility of immunologic reactions. The covering may be comprised of any biocompatible material, such as polyethylene terepthalate, polyester, cotton, polyurethane, expanded polytetrafluoroethylene (ePTFE), silicon, or various polymers or fibers and have any suitable form, such as a fabric, mesh, textured weave, felt, looped or porous structure. Generally, the covering has a low profile so as not to interfere with delivery through an introducer sheath or with grasping and coapting of leaflets or tissue.
[0151] FIGS. 17A-17C illustrate a covering 100 on the fixation device 14 wherein the device 14 is in various positions. FIG. 17A shows the covering 100 encapsulating the distal elements 18 and the actuation mechanism 58 while the device 14 is in the open position. Thus, the engagement surfaces 50 are covered by the covering 100 which helps to minimize trauma on tissues and provides additional friction to assist in grasping and retaining tissues. FIG. 17B shows the device 14 of FIG. 17A in the inverted position. The covering 100 is loosely fitted and/or is flexible or elastic such that the device 14 can freely move to various positions and the covering 100 conforms to the contours of the device 14 and remains securely attached in all positions. FIG. 17C shows the device 14 in the closed position. Thus, when the fixation device 14 is left behind as an implant in the closed position, the exposed surfaces of the device 14 are substantially covered by the covering 100 . It may be appreciated that the covering 100 may cover specific parts of the fixation device 14 while leaving other parts exposed. For example, the covering 100 may comprise sleeves that fit over the distal elements 18 and not the actuation mechanism 58 , caps that fit over the distal ends 54 of the distal elements 18 or pads that cover the engagement surfaces 50 , to name a few. It may be appreciated that, the covering 100 may allow any frictional accessories, such as barbs, to be exposed. Also, the covering 100 may cover the proximal elements 16 and/or any other surfaces of the fixation device 14 . In any case, the covering 100 should be durable to withstand multiple introduction cycles and, when implanted within a heart, a lifetime of cardiac cycles.
[0152] The covering 100 may alternatively be comprised of a polymer or other suitable materials dipped, sprayed, coated or otherwise adhered to the surfaces of the fixation device 14 . Optionally, the polymer coating may include pores or contours to assist in grasping the tissue and/or to promote tissue ingrowth.
[0153] Any of the coverings 100 may optionally include drugs, antibiotics, anti-thrombosis agents, or anti-platelet agents such as heparin, COUMADIN® (Warfarin Sodium), to name a few. These agents may, for example, be impregnated in or coated on the coverings 100 . These agents may then be delivered to the grasped tissues surrounding tissues and/or bloodstream for therapeutic effects.
[0154] C. Fixation Device Locking Mechanisms
[0155] As mentioned previously, the fixation device 14 optionally includes a locking mechanism for locking the device 14 in a particular position, such as an open, closed or inverted position or any position therebetween. It may be appreciated that the locking mechanism includes an unlocking mechanism which allows the device to be both locked and unlocked. FIGS. 18-21 illustrate an embodiment of a locking mechanism 106 . Referring to FIG. 18 , in this embodiment, the locking mechanism 106 is disposed between the coupling member 19 and the base 69 of the actuation mechanism 58 . The base 69 is fixedly attached to the stud 74 which extends through the locking mechanism 106 . The stud 74 is releasably attached to the actuator rod 64 which passes through the coupling member 19 and the shaft 12 of the interventional tool 10 . The base 69 is also connected to the legs 68 of the actuation mechanism 58 which are in turn connected to the distal elements 18 .
[0156] FIG. 18 also illustrates the proximal elements 16 , which in this embodiment straddle the locking mechanism and join beneath the locking mechanism 106 . The proximal elements 16 are shown supported by proximal element lines 90 . The proximal elements 16 are raised and lowered by manipulation of the proximal element lines 90 . In addition, lock lines 92 are shown connected with a release harness 108 of the locking mechanism 106 . The lock lines 92 are used to lock and unlock the locking mechanism 106 as will be described below. The proximal element lines 90 and lock lines 92 may be comprised of any suitable material, typically wire, nitinol wire, cable, suture or thread, to name a few. In addition, the proximal element lines 90 and/or lock lines 92 may include a coating, such as parylene. Parylene is a vapor deposited pinhole free protective film which is conformal and biocompatible. It is inert and protects against moisture, chemicals, and electrical charge.
[0157] FIG. 19 provides a front view of the locking mechanism 106 of FIG. 18 . However, here the proximal elements 16 are supported by a single proximal element line 90 which is through both of the proximal elements 16 . In this arrangement both of the elements are raised and lowered simultaneously by action of a single proximal element line 90 . Whether the proximal elements 16 are manipulated individually by separate proximal element lines 90 or jointly by a single proximal element line 90 , the proximal element lines 90 may extend directly through openings in the proximal elements and/or through a layer or portion of a covering 100 on the proximal elements, or through a suture loop above or below a covering 100 .
[0158] FIGS. 20-21 illustrate the locking mechanism 106 showing the locking mechanism 106 in the unlocked and locked positions respectively. Referring to FIG. 20 , the locking mechanism 106 includes one or more wedging elements, such as rolling elements. In this embodiment, the rolling elements comprise a pair of barbells 110 disposed on opposite sides of the stud 74 , each barbell having a pair of generally cylindrical caps and a shaft therebetween. The barbells 110 and the stud 74 are preferably comprised of cobalt chromium or stainless steel, however any suitable material may be used. The barbells 110 are manipulated by hooked ends 112 of the release harness 108 . When an upwards force is applied to the harness 108 by the lock line 92 (illustrated in FIG. 18 ), the hooked ends 112 raise the barbells 110 against a spring 114 , as shown in FIG. 20 . This draws the barbells 110 up along a sidewall or sloping surface 116 which unwedges the barbells 110 from against the stud 74 . In this position, the stud 74 is free to move. Thus, when the lock line 92 raises or lifts the harness 108 , the locking mechanism 106 is in an unlocked position wherein the stud 74 is free to move the actuation mechanism 58 and therefore the distal elements 18 to any desired position. Release of the harness 108 by the lock line 92 transitions the locking mechanism 106 to a locked position, illustrated in FIG. 21 . By releasing the upwards force on the barbells 110 by the hooked ends 112 , the spring 114 forces the barbells 110 downwards and wedges the barbells 110 between the sloping surface 116 and the stud 74 . This restricts motion of the stud 74 , which in turn locks the actuation mechanism 58 and therefore distal elements 18 in place. In addition, the stud 74 may include one or more grooves 82 or indentations which receive the barbells 110 . This may provide more rapid and positive locking by causing the barbells 110 to settle in a definite position, increase the stability of the locking feature by further preventing movement of the barbells 110 , as well as tangible indication to the user that the barbell has reached a locking position. In addition, the grooves 82 may be used to indicate the relative position of the distal elements 18 , particularly the distance between the distal elements 18 . For example, each groove 82 may be positioned to correspond with a 0.5 or 1.0 mm decrease in distance between the distal elements 18 . As the stud 74 is moved, the barbells 110 will contact the grooves 82 ; by counting the number of grooves 82 that are felt as the stud 74 is moved, the user can determine the distance between the distal elements 18 and can provide the desired degree of coaptation based upon leaflet thickness, geometry, spacing, blood flow dynamics and other factors. Thus, the grooves 82 may provide tactile feedback to the user.
[0159] The locking mechanism 106 allows the fixation device 14 to remain in an unlocked position when attached to the interventional tool 10 during grasping and repositioning and then maintain a locked position when left behind as an implant. It may be appreciated, however, that the locking mechanism 106 may be repeatedly locked and unlocked throughout the placement of the fixation device 14 if desired. Once the final placement is determined, the lock line 92 and proximal element lines 90 are removed and the fixation device is left behind.
[0160] FIGS. 23 , 24 A- 24 B illustrate another embodiment of a locking mechanism 106 . Referring to FIG. 23 , in this embodiment, the locking mechanism 106 is again disposed between the coupling member 19 and the base 69 of the actuation mechanism 58 . The base 69 is connected to the stud 74 which extends through the locking mechanism 106 , and connects to an actuator rod which extends through the coupling member 19 and the shaft 12 of the interventional tool 10 . The base 69 is also connected to the legs 68 of the actuation mechanism 58 which are in turn connected to the distal elements 18 . FIG. 23 also illustrates the proximal elements 16 which manipulate the locking mechanism 106 in this embodiment. The locking mechanism 106 comprises folded leaf structures 124 having overlapping portions 124 a , 124 b , each folded structure 124 being attached to a proximal element 16 . In FIG. 23 and FIG. 24A , the folded structures 124 are shown without the remainder of the locking mechanism 106 for clarity. Proximal elements 16 are flexible and resilient and are biased outwardly. The folded leaf structures 124 include holes 125 ( FIG. 24B ) in each overlapping portion 124 a , 124 b so that the stud 74 passes through the holes 125 of the portions 124 a , 124 b as shown. The locking mechanism includes slots into which ends 123 of the folded leaf structures 124 are fixed. When the proximal elements 16 are in an undeployed position, as in FIG. 23 , the folded leaf structures 124 lie substantially perpendicular to the stud 74 so that the holes 125 in each overlapping portion are vertically aligned. This allows the stud 74 to pass freely through the holes and the locking mechanism 106 is considered to be in an unlocked position.
[0161] Deployment of the proximal elements 16 , as shown in FIG. 24A , tilts the folded leaf structures 124 so as to be disposed in a non-perpendicular orientation relative to the stud 74 and the holes 125 are no longer vertically aligned with one another. In this arrangement, the stud 74 is not free to move due to friction against the holes of the folded leaf structure 124 . FIG. 24B provides a larger perspective view of the folded structures 124 in this position. Thus, the locking mechanism 106 is considered to be in a locked position. This arrangement allows the fixation device 14 to maintain an unlocked position during grasping and repositioning and then maintain a locked position when the proximal elements 16 are deployed and the fixation device 14 is left behind as an implant. It may be appreciated, however, that the locking mechanism 106 may be repeatedly locked and unlocked throughout the placement of the fixation device 14 if desired.
[0162] FIGS. 25 , 26 A- 26 B illustrate another embodiment of a locking mechanism 106 . Referring to FIG. 25 , in this embodiment, the locking mechanism 106 is again disposed between the coupling member 19 and the base 69 of the actuation mechanism 58 . And, the base 69 is connected to the stud 74 which extends through the locking mechanism 106 and connects to an actuator rod which extends through the coupling member 19 and the shaft of the interventional tool 10 . FIG. 25 illustrates the proximal elements 16 which manipulate the locking mechanism 106 in this embodiment. The locking mechanism 106 comprises C-shaped structures 128 , each C-shaped structure 128 attached to a proximal element 16 . The C-shaped structures 128 hook around the stud 74 so that the stud 74 passes through the “C” of each structure 128 as shown in FIGS. 26A-26B . As shown, the structures 128 cross each other and the “C” of each structure 128 faces each other. A spring 130 biases the C-shaped structures into engagement with one another. When the proximal elements are in an undeployed position, as in FIG. 26A , the C-shaped structures 128 are urged into an orientation more orthogonal to the axial direction defined by stud 74 , thus bringing the “C” of each structure 128 into closer axial alignment. This allows the stud 74 to pass freely through the “C” of each structure 128 . Deployment of the proximal elements 16 outwardly urges the C-shaped structures into a more angular, non-orthogonal orientation relative to stud 74 causing the sidewalls of the “C” of each structure 128 to engage stud 74 more forcefully. In this arrangement, the stud 74 is not free to move due to friction against the “C” shaped structures 128 .
[0163] D. Additional Embodiments of Fixation Devices
[0164] FIGS. 22A-22B illustrate a variation of the fixation device 14 described above in which the distal and proximal elements 16 , 18 on each side of the fixation device are movable laterally toward and away from each other to facilitate capture of more widely-separated leaflets or other tissue flaps. The coupling member 19 is bifurcated into two resilient and flexible branches 19 A, 19 B which are biased outwardly into the position shown in FIG. 22A , but which are movable to the position shown in FIG. 22B . As an alternative, branches 19 A, 19 B may be more rigid members connected to coupling member 19 by pins or hinges so as to be pivotable toward and away from each other. Each of proximal elements 16 and distal elements 18 are coupled at their proximal ends to one branch 19 A or 19 B of the coupling member 19 . Legs 68 are coupled at their proximal ends to base 69 , and therefore stud 74 , and at their distal ends to distal elements 18 , as described above. Translation of stud 74 distally or proximally relative to coupling member 19 opens or closes distal elements 18 as in formerly described embodiments. A collar 131 is slidably disposed over coupling member 19 and has an annular groove 133 on its inner wall configured to slide over and frictionally engage detents 135 on branches 19 A, 19 B. A sheath 137 is positioned coaxially over shaft 12 and is slidable relative thereto to facilitate pushing collar 131 distally over coupling member 19 .
[0165] In use, the embodiment of FIGS. 22A-22B is introduced with distal and proximal elements 16 , 18 in the closed position. Collar 131 is pushed distally against, but not over, detents 135 so that branches 19 A, 19 B are disposed together and fixation device 14 has a minimal profile. When the user is ready to capture the target tissue (e.g. valve leaflets), sheath 137 is retracted so that collar 131 slides proximally over coupling member 19 . This allows branches 19 A, 19 B to separate into the position of FIG. 22A . Actuator 64 is pushed distally so as to open distal elements 18 . Tension is maintained on proximal element lines 90 (not shown in FIGS. 22A-22B ) so that proximal elements 16 remain separated from distal elements 18 . When tissue is positioned between the proximal and distal elements, tension is released on proximal element lines 90 allowing the tissue to be captured between the proximal and distal elements. Sheath 137 may then be advanced distally so that collar 131 urges branches 19 A, 19 B back together. Sheath 137 is advanced until groove 133 in collar 131 slides over detents 135 and is frictionally maintained thereon as shown in FIG. 22B . Sheath 137 may then be retracted from collar 131 . Distal elements 18 may be closed, opened or inverted by advancing or retracting stud 74 via actuator 64 , as in the embodiments described above. It should be understood that the embodiment of FIGS. 22A-22B preferably includes a locking mechanism as described above, which has been omitted from the figures for clarity.
[0166] In a further alternative of the embodiment of FIGS. 22A-22B , fixation device 14 may be configured to allow for independent actuation of each of the lateral branches 19 A, 19 B and/or distal elements 18 . In an exemplary embodiment, shaft 12 and coupling member 19 may be longitudinally split into two identical halves such that a first branch 19 A may be drawn into collar 131 independently of a second branch 19 B. Similarly, actuator shaft 64 may be longitudinally split so that each half can slide independently of the other half, thus allowing one of distal elements 18 to be closed independently of the other distal element 18 . This configuration permits the user to capture one of the valve leaflets between one of the distal and proximal elements 16 , 18 , then draw the corresponding branch 19 A into the collar 131 . The fixation device 14 may then be repositioned to capture a second of the valve leaflets between the other proximal and distal elements 16 , 18 , after which the second branch 19 B may be drawn into collar 131 to complete the coaptation. Of course, the closure of distal elements 18 may occur either before or after branches 19 A, 19 B are drawn into collar 131 .
[0167] FIGS. 27-28 illustrate an additional embodiment of the fixation device 14 . As shown in FIG. 27 , the fixation device 14 includes a coupling member 19 which couples the device 14 to the shaft 12 of the interventional tool 10 . Here, the device 14 also includes a top coupler 150 attached to coupling member 19 and a bottom coupler 152 attached to the stud 74 so that the two couplers are axially moveable relative to one another. The distal elements 18 are rotatably attached to the top coupler 150 by upper pins 156 and rotatably attached to the bottom coupler 152 by lower pins 160 . When the bottom coupler 152 is advanced, the pins 156 , 160 are drawn apart. The upper pins 156 are disposed within slots 158 as shown. When the bottom coupler 152 is advanced distally relative to top coupler 150 , pins 156 , 160 are drawn apart. Angling of the slots 158 causes the distal elements 18 to rotate toward the coupling member 19 as the pins 156 , 160 are drawn apart. Relative movement of the couplers 150 , 152 may be achieved by any suitable mechanism including sliding or threading.
[0168] FIG. 28 illustrates the fixation device 14 in the closed position. Here, the device 14 has a low profile (width in the range of approximately 0.140-0.160 inches orthogonal to the axial direction defined by shaft 12 /stud 74 ) so that the device 14 may be easily passed through a catheter and through any tissue structures. To open the device 14 the bottom coupler 152 is then retracted or the couplers 150 , 152 brought toward one another to rotate the distal elements 18 outward. The components of the fixation device 14 may be formed from stainless steel or other suitable metal, such as by machining, or formed from a polymer, such as by injection molding. In addition, portions of the fixation device 14 , particularly the distal elements 18 , may be covered with a covering such as described above, to promote tissue ingrowth, reduce trauma, enhance friction and/or release pharmacological agents. Alternatively, the device 14 may have a smooth surface which prevents cellular adhesion thereby reducing the accumulation of cells having potential to form an emboli.
[0169] Optionally, the fixation device 14 may include tissue retention features such as barbs 170 and/or bumpers 172 , illustrated in FIGS. 29-30 . The barbs 170 may extend from the engagement surfaces 50 of the distal elements 18 , as shown, and may be present in any number and any arrangement. Thus, the barbs 170 will engage the leaflets or tissue during grasping to assist in holding the tissue either by frictional engagement, minor surface penetration or by complete piercing of the tissue, depending on the length and shape of the barbs 170 selected. Alternatively or in addition, bumpers 172 may extend from the distal elements 18 . As shown in FIG. 29 , each bumpers 172 may extend from the proximal end 52 of the distal element 18 and curve toward the free end 54 of the distal element 18 . Or, as shown in FIG. 30 , each bumper 172 may extend from the free end 54 and curve toward the proximal end 52 . Bumpers 172 are preferably constructed of a resilient metal or polymer and may have any of various geometries, including a solid thin sheet or a loop-shaped wire form. The bumpers 172 may help to actively engage and disengage tissue from the barbs 170 during opening and closing of the fixation device 14 . Further, to assist in grasping a tissue, the engagement surfaces 50 may have any texture or form to increase friction against the grasped tissue. For example, the surfaces 50 may include serrations, scales, felt, barbs, polymeric frictional elements, knurling or grooves, to name a few.
[0170] FIG. 31 illustrates the engagement surface 50 having a serrated edge 174 to improve grip on tissue engaged. FIG. 31 also illustrates an embodiment of the fixation device 14 mounted on an interventional tool 10 or delivery catheter for ventricular approach to the mitral valve. Here the device 14 is mounted on the shaft 12 with the engagement surfaces 50 facing distally relative to shaft 12 (and facing upstream relative to the mitral valve). Thus, when the mitral valve is approached from the ventricular side, the engagement surfaces 50 can be pressed against the downstream surfaces of the valve without passing through the valve. It may be appreciated that any of the embodiments of the fixation device 14 described herein may be mounted on shaft 12 in this orientation for approach to any valve or tissue, including embodiments that include both proximal and distal elements.
[0171] It may be appreciated that when the fixation device 14 is mounted on the shaft 12 in orientation illustrated in FIG. 31 , the position of the distal elements and the proximal elements are reversed. In such instances it is useful to keep in mind that the distal elements contact the distal surface or downstream surface of the leaflets and the proximal elements contact the proximal surface or upstream surface of the leaflets. Thus, regardless of the approach to the valve and the relative position of the proximal and distal elements on the fixation device, the proximal and distal elements remain consistent in relation to the valve.
[0172] FIGS. 32-34 illustrate an additional embodiment of the fixation device 14 . As shown in FIG. 32 , the fixation device 14 includes a coupling member 19 , proximal elements 16 and distal elements 18 which are each connected to a set of base components 186 . The distal elements 18 are connected to the base components 186 (top base component 186 a and a bottom base component 186 b ) by extension arms 188 . In this embodiment, each distal element 18 is connected by two extension arms 188 in a crossed arrangement so that one extension arm 188 connects the distal element 18 to the top base component 186 a and the other extension arm 188 ′ connects the distal element 18 to the bottom base component 186 b . The top base component 186 a can be separated from the bottom base component 186 b by any suitable method which may be torque driven, spring driven or push/pull. Increasing the separation distance between the base components 186 draws the distal elements 18 inwards toward the base components 186 , as shown in FIG. 33 . This allows the tissue to be grasped between the distal elements 18 and proximal elements 16 while in an arrangement wherein the distal elements 18 are parallel to each other. This may prevent inconsistent compression of the tissue and may better accommodate tissues or leaflets of varying thicknesses. As shown in FIG. 34 , the distal elements 18 may be drawn together and the proximal elements 16 may be retracted to form a low profile fixation device 14 .
[0173] FIGS. 35-39 , 40 A- 40 D, 41 - 42 , 43 A- 43 C illustrate another embodiment of the fixation device 14 . In this embodiment, the device 14 is deliverable in the inverted position and moveable to the open position for grasping of the tissue. FIG. 35 illustrates the fixation device 14 in the inverted position. The fixation device 14 includes a shaft 198 , proximal elements 16 and distal elements 18 . Each distal element 18 has a proximal end 52 rotatably connected to the shaft 198 and a free end 54 . The fixation device 14 also includes an actuator rod 204 , a base 202 and a pair of deployment arms 200 attached to the base 202 as shown. In the inverted position, the extender 204 is extended and deployment arms 200 are disposed between the actuator rod 204 and the distal elements 18 . As shown in FIG. 36 , the actuator rod 204 may be retracted so that the deployment arms 200 press against the distal elements 18 , rotating the distal elements 18 from the inverted position to the open position. The angle of the distal elements 18 may be adjusted by retracting or extending the actuator rod 204 various distances. As shown in FIG. 37 , further retraction of the actuator rod 204 raises the distal elements 18 further.
[0174] In the open position, tissue or leaflets may be grasped between the distal elements 18 and proximal elements 16 . FIG. 38 illustrates the proximal elements 16 in their released position wherein the tissue or leaflet would be present therebetween. Hereinafter, the tissue will be referred to as leaflets. In this embodiment, each distal element 18 includes an implant pledget 210 , typically press-fit or nested within each distal element 18 . The implant pledgets 210 will be attached to the leaflets by ties, such as sutures or wires, and will be used to hold the leaflets in desired coaptation. The implant pledgets 210 will then be separated from the fixation device 14 and will remain as an implant.
[0175] To attach the implant pledgets 210 to the leaflets, the leaflets and implant pledgets 210 are punctured by fixation tools 220 , as shown in FIG. 39 . The fixation tools 220 extend from the catheter 86 , pass through the leaflets and puncture the implant pledgets 210 . Thus, the pledgets 210 are comprised of a puncturable material, such as structural mesh. The fixation tools 220 are used to deliver an anchor 222 as illustrated in larger view in FIGS. 40A-40D . FIG. 40A shows the fixation tool 220 including a sleeve 224 surrounding the fixation tool 220 and an anchor 222 loaded therebetween. In this embodiment, the anchor includes one or more flaps 228 which are held within the sleeve 224 . It may be appreciated that the anchor 222 may have any suitable form. Additional exemplary embodiments of anchors are provided in commonly assigned U.S. Pat. No. 6,752,813 (Attorney Docket No. 020489-000400US) incorporated herein for all purposes. A suture 226 is attached to the anchor 222 and extends through the sleeve 224 or on the outside of the sleeve 224 , as shown, to the catheter 86 . The fixation tools 220 are advanced so that the anchor 222 passes through the leaflet (not shown) and the pledget 210 , as shown in FIG. 41 .
[0176] Referring now to FIG. 40B , the sleeve 224 is then retracted to expose the flaps 228 which releases the anchor 222 from the confines of the sleeve 224 . The flaps 228 extend radially outwardly, illustrated in FIG. 40C , by spring loading, shape memory or other self-expanding mechanism. Thus, the flaps 228 are positioned against the distal side of the pledget 210 , the suture 226 passing through the pledget 210 and the leaflet, as shown in FIG. 41 . At this point, the pledgets 210 can be removed from the distal elements 18 . By extending the actuator rod 204 distally, the base 202 draws the deployment arms 200 distally which returns the distal elements 18 to the inverted position, as shown in FIG. 42 . Since the pledgets 210 have been pierced by the fixation tools 220 and the anchors 222 have been deployed, the pledgets 210 and the leaflets disengage from distal elements 18 and remain in position. The proximal elements 16 may also be returned to their initial position as shown, using any of various mechanisms as have been described above in connection with other embodiments. Referring now to FIG. 40D , the fixation tool 220 is then removed while the anchor 222 remains in place with suture 226 attached.
[0177] The implant pledgets 210 are then separated from the fixation device 14 and left behind to maintain coaptation of the leaflets in the desired position. FIGS. 43A-43C illustrate the implant pledgets 210 from various perspective views. FIG. 43A provides a perspective top view showing that the pledgets 210 are connected by a link 230 that allows the pledgets 210 to be released from one side of the fixation device 14 . In addition, the sutures 226 are fixed together, either by knot tying or placement of a suture fastener 232 as shown. It may be appreciated that the suture fastener 232 may have any suitable form. Additional exemplary embodiments of suture fasteners 232 are provided in commonly-assigned U.S. Pat. No. 7,048,754 (Attorney Docket No. 020489-000500US), which is incorporated herein by reference for all purposes. FIG. 43B provides a perspective bottom view showing the anchor 222 positioned against the bottom side of the pledget 210 . Likewise, FIG. 43C provides a perspective side view also showing the anchor 222 positioned against the bottom side of the pledget 210 .
[0178] FIGS. 44A-44B , 45 - 46 illustrate another embodiment of the fixation device 14 . As shown in FIG. 44A , the fixation device 14 is mounted on the shaft 12 and is comprised of distal elements 18 and a retention clip 36 comprised of a semi-rigid material having a folded shape. The material may be any suitable material providing rigidity with recoiling properties such as various metals or plastics. The folded shape is such that a fold 252 is directed distally and free ends 254 are directed proximally toward the distal elements 18 . Penetration elements 256 are disposed near the free ends 254 and directed toward the shaft 12 . In addition, an opening 258 is located near the fold 252 , as illustrated in FIG. 44B which provides a perspectives view of the device 14 . Referring back to FIG. 44A , the fold 252 is attached to an actuator rod 74 which passes through the shaft 12 and an arrow-shaped structure 260 is disposed on the shaft 12 between the free ends 254 , proximal to the opening 258 , as shown. In this arrangement, the fixation device 14 is advanced through the valve so that the distal elements 18 are disposed below the leaflets. The device may then be retracted proximally to capture the leaflets within the distal elements 18 . As shown in FIG. 45 , retraction of the actuator rod 74 draws the retention clip 36 toward the distal elements 18 so that the sloping sides of the arrow-shaped structure 260 force the free ends 254 outward, away from the shaft 12 . Further retraction of actuator rod 74 results in the sloping sides of arrow shaped structure 260 falling into the opening 258 in retention clip 36 , causing retention clip 36 to recoil back to the closed position as shown in FIG. 46 , with the free ends 254 extending through the distal elements 18 . This allows the penetration elements 256 to penetrate the leaflets (not shown) to secure engagement therewith. The actuator rod 74 is then detached from the retention clip 36 and shaft 12 is detached from distal elements 18 which are left in place to hold the leaflets in a coapted arrangement.
[0179] It may be appreciated that the foregoing embodiment may also include proximal elements 16 configured to be positioned on the upstream side of the valve leaflets to assist in the capture and fixation. Such proximal elements may be mounted to shaft 12 so as to be removed following fixation of the leaflets, or the proximal elements may be connected to distal elements 18 and/or retention clip 36 to be implanted therewith.
[0180] In further embodiments, the proximal elements may be manipulated to enhance gripping. For example, the proximal elements may be lowered to grasp leaflets or tissue between the proximal and distal elements, and then the proximal elements may be moved to drag the leaflets or tissue into the fixation device. In another example, the proximal elements may be independently lowered to grasp the leaflets or tissue. This may be useful for sequential grasping. In sequential grasping, one proximal element is lowered to capture a leaflet or tissue portion between the proximal and distal elements. The fixation device is then moved, adjusted or maneuvered to a position for grasping another leaflet or tissue portion between another set of proximal and distal elements. In this position, the second proximal element is then lowered to grasp this other leaflet or tissue portion.
IV. Delivery Device
[0181] A. Overview of Delivery Device
[0182] FIG. 47 provides a perspective view of an embodiment of a delivery device or delivery catheter 300 which may be used to introduce and position a fixation device as described above. The delivery catheter 300 includes a shaft 302 , having a proximal end 322 and a distal end 324 , and a handle 304 attached to the proximal end 322 . A fixation device (not shown) is removably coupleable to the distal end 324 for delivery to a site within the body, typically for endovascular delivery to the mitral valve. Thus, extending from the distal end 324 is a coupling structure 320 for coupling with a fixation device. Also extending from the distal end 324 is an actuator rod 64 . The actuator rod 64 is connectable with the fixation device and acts to manipulate the fixation device, typically opening and closing the distal elements. Such coupling to a fixation device is illustrated in FIG. 48 .
[0183] FIG. 48 illustrates an embodiment of a fixation device 14 coupled to the distal end 324 of the delivery catheter 300 . The shaft 302 is shown having a nose 318 near its distal end 324 . In this embodiment, the nose 318 has a flanged shape. Such a flanged shape prevents the nose 318 from being retracted into a guiding catheter or introducer as will be discussed in later sections. However, it may be appreciated that the nose 318 may have any shape including bullet, rounded, blunt or pointed, to name a few. Extending from the nose 318 is a compression coil 326 through which the coupling structure 320 and actuator rod 64 pass. The actuator rod 64 is coupleable, as shown, with the stud 74 of the fixation device 14 . Such coupling is illustrated in FIG. 49 .
[0184] FIG. 49 illustrates a portion of the shaft 302 of the delivery catheter 300 and a fixation device 14 which is coupleable with the catheter 300 . Passing through the shaft 302 is the actuator rod 64 . In this embodiment, the actuator rod 64 comprises a proximal extremity 303 and a distal extremity 328 , the distal extremity 328 of which is surrounded by a coil 330 . The proximal extremity 303 is typically comprised of stainless steel, nitinol, or Elgiloy®, to name a few, and may have a diameter in the range of 0.010 in. to 0.040 in., preferably 0.020 in. to 0.030 in., more preferably 0.025 in., and a length in the range of 48 to 72 in. The distal extremity 328 may be tapered, is typically comprised of stainless steel, nitinol, or Elgiloy®, to name a few, and may have a diameter in the range of 0.011 to 0.025 in and a length in the range of 4 to 12 in. Such narrowing increases flexibility of the distal end 324 of the actuator rod 64 . The actuator rod 64 further comprises a joiner 332 which is attached to the distal extremity 328 . The joiner 332 is removably attachable with stud 74 of the fixation device 14 . In this embodiment, the joiner 332 has internal threads which mate with external threads on the stud 74 of the fixation device 14 . As described previously, the stud 74 is connected with the distal elements 18 so that advancement and retraction of the stud 74 , by means of the actuator rod 64 , manipulates the distal elements. Likewise, the coupling member 19 of the fixation device 14 mates with the coupling structure 320 of the catheter 300 . Thus, the coupling member 19 and coupling structure 320 function as previously described in relation to FIGS. 6A-6B .
[0185] Referring back to FIG. 48 , the fixation device 14 may also include a locking mechanism which includes a release harness 108 , as previously described in relation to FIGS. 18-21 . Lock lines 92 are connected with the release harness 108 to lock and unlock the locking mechanism 106 as previously described. The lock lines 92 extend through the shaft 302 of the delivery catheter 300 and may connect with the release harness 108 in various arrangements as will be illustrated in later sections. Similarly, proximal element lines 90 extend through the shaft 302 of the delivery catheter 300 and connect with the proximal elements 16 . The proximal elements 16 are raised and lowered by manipulation of the proximal element lines 90 as previously described. The proximal element lines 90 may connect with the proximal elements 16 in various arrangements as will be illustrated in later sections.
[0186] Referring back to FIG. 47 , the handle 304 attached to the proximal end 322 of the shaft 302 is used to manipulate the coupled fixation device 14 and to optionally decouple the fixation device 14 for permanent implantation. As described, the fixation device 14 is primarily manipulated by the actuator rod 64 , proximal element lines 90 and lock lines 92 . The actuator rod 64 manipulates the distal elements 18 , the proximal element lines 90 manipulate the proximal elements 16 and the lock lines 92 manipulate the locking mechanism. In this embodiment, the actuator rod 64 may be translated (extended or retracted) to manipulate the distal elements 18 . This is achieved with the use of the actuator rod control 314 which will be described in later sections. The actuator rod 64 may also be rotated to engage or disengage the threaded joiner with the threaded stud 74 . This is achieved with the use of the actuator rod handle 316 which will also be described in later sections. Further, the proximal element lines 90 may be extended, retracted, loaded with various amounts of tension or removed with the use of the proximal element line handle 312 . And, the lock lines 92 may be may be extended, retracted, loaded with various amounts of tension or removed with the use of the lock line handle 310 . Both of these handles 310 , 312 will be described in more detail in later sections. The actuator rod handle 316 , actuator rod control 314 , proximal element line handle 312 and lock line handle 310 are all joined with a main body 308 within which the actuator rod 64 , proximal element lines 90 and lock lines 92 are guided into the shaft 302 . The handle 304 further includes a support base 306 connected with the main body 308 . The main body 308 is slideable along the support base 306 to provide translation of the shaft 302 . Further, the main body 308 is rotateable around the support base 306 to rotate the shaft.
[0187] B. Delivery Catheter Shaft
[0188] FIG. 50 illustrates a cross-sectional view of the delivery catheter shaft 302 of FIG. 47 . In this embodiment, the shaft 302 has a tubular shape with inner lumen 348 and is comprised of a material which provides hoop strength while maintaining flexibility and kink resistance, such as a braided laminated material. Such material may include stainless steel braided or coiled wire embedded in a polymer such as polyurethane, polyester, Pebax, Grilamid TR55, and AESNO to name a few. To provide further support and hoop strength, a support coil 346 is disposed within the lumen 348 of shaft 302 as illustrated in FIG. 50 .
[0189] Passing through the support coil 346 are a variety of elongated bodies, including tubular guides and cylindrical rods. For example, one type of tubular guide is a compression coil 326 extending through lumen 348 from the proximal end 322 to the distal end 324 of the shaft 302 , and the actuator rod 64 extends through the compression coil 326 . Therefore, the compression coil typically has a length in the range of 48 to 60 in. and an inner diameter in the range of 0.020 to 0.035 in. to allow passage of the actuator rod 64 therethrough. The actuator rod 64 is manipulable to rotate and translate within and relative to the compression coil 326 . The compression coil 326 allows lateral flexibility of the actuator rod 64 and therefore the shaft 302 while resisting buckling and providing column strength under compression. The compression coil may be comprised of 304V stainless steel to provide these properties.
[0190] To provide additional tensile strength for the shaft 302 and to minimize elongation, a tension cable 344 may also pass through the support coil 346 . The tension cable 344 extends through lumen 348 from the proximal end 322 to the distal end 324 of the shaft 302 . Therefore, the tension cable 344 typically has a diameter in the range of 0.005 in. to 0.010 in. and a length in the range of 48 to 60 in. In preferred embodiments, the tension cable 344 is comprised of 304V stainless steel.
[0191] In addition, at least one lock line shaft 341 having a tubular shape may be present having a lock line lumen 340 through which lock lines 92 pass between the lock line handle 310 and the locking mechanism 106 . The lock line shaft 341 extends through lumen 348 from the proximal end 322 to the distal end 324 of the shaft 302 . Therefore, the lock line shaft 341 typically has a length in the range of 48 to 60 in., an inner diameter in the range of 0.016 to 0.030 in., and an outer diameter in the range of 0.018 to 0.034 in. In preferred embodiments, the lock line shaft 341 is comprised of a 304V stainless steel coil however other structures or materials may be used which provide kink resistance and compression strength.
[0192] Similarly, at least one proximal element line shaft 343 having a tubular shape may be present having a proximal element line lumen 342 . Proximal element lines 90 pass through this lumen 342 between the proximal element line handle 312 and the proximal elements 16 . Thus, the proximal element line shaft 343 extends through lumen 348 from the proximal end 322 to the distal end 324 of the shaft 302 . Therefore, the proximal element line shaft 343 typically has a length in the range of 48 to 60 in., an inner diameter in the range of 0.016 to 0.030 in., and an outer diameter in the range of 0.018 to 0.034 in. In preferred embodiments, the proximal element line shaft 343 is comprised of a 304V stainless steel coil however other structures or materials may be used which provide kink resistance and compression strength.
[0193] In this embodiment, the elongated bodies (compression coil 326 enclosed actuator rod 64 , tension cable 344 , lock line shaft 342 , proximal element line shaft 343 ) each “float” freely in inner lumen 348 within the support coil 346 and are fixed only at the proximal end 322 and distal end 324 of shaft 302 . The lumen 348 is typically filled and flushed with heparinized saline during use. Alternatively or in addition, the lumen 348 may be filled with one or more fillers, such as flexible rods, beads, extruded sections, gels or other fluids. Preferably the fillers allow for some lateral movement or deflection of the elongated bodies within lumen 348 but in some cases may restrict such movement. Typically, the elongated bodies are fixed at the proximal and distal ends of the shaft and are free to move laterally and rotationally therebetween. Such freedom of movement of the elongated bodies provides the shaft 302 with an increased flexibility as the elongated bodies self-adjust and reposition during bending and/or torqueing of the shaft 302 . It may be appreciated that the elongated bodies may not be fixed at the proximal and distal ends. The elongated bodies are simply unconstrained relative to the shaft 302 in at least one location so as to be laterally moveable within the lumen 348 . Preferably the elongated bodies are unrestrained in at least a distal portion of the catheter, e.g. 5-15 cm from the distal end 324 , so as to provide maximum flexibility in the distal portion.
[0194] It may be appreciated, however, that alternate shaft 302 designs may also be used. For example, referring to FIG. 51 , in this embodiment the shaft 302 again has a tubular shape with an inner lumen 348 and a support coil 346 disposed within the lumen 348 of shaft 302 . Filling the inner lumen 348 within the support coil 346 is an extrusion 334 having lumens through which pass a variety of elongated bodies, including the compression coil 326 enclosed actuator rod 64 , tension cable 344 , lock line shafts 342 , and proximal element line shafts 343 , as shown. The support coil 346 and elongated bodies may have the same geometries and be comprised of the same materials as described above in relation to FIG. 50 .
[0195] Alternatively, as shown in FIG. 52 , the shaft 302 may include an internal partition 350 to create multiple lumens within the shaft 302 . For example, the partition 350 may have a central lumen 352 for passage of the actuator rod 64 , optionally surrounded by the compression coil 326 . In addition, the partition 350 may also create at least one lock line lumen 340 for passage of a lock line 92 and at least one proximal element line lumen 341 for passage of a proximal element line 90 . Optionally, each of the lumens defined by partition 350 may be lined with a kink-resistant element, such as a coil as in previous embodiments.
[0196] FIGS. 52A-52C illustrate embodiments of the nose 318 of the shaft 302 . In FIG. 52A , the nose 318 comprises a tip ring 280 and a lock ring 282 . In preferred embodiments, Epoxy and PEBAX are deposited between the tip ring 280 and the lock ring 282 to bond them together. The lock ring 282 has a geometry to mate with the tip ring 280 to maintain relative alignment between the two. FIG. 52B illustrates another embodiment of the nose 318 of the shaft 302 . Here, the tip ring 280 is covered by a soft tip 284 to provide a more atraumatic tip and a smoother transition to the shaft.
[0197] C. Lock Line Arrangements
[0198] As mentioned previously, when lock lines 92 are present, the lines 92 pass through at least one lock line lumen 340 between the lock line handle 310 and the locking mechanism 106 . The lock lines 92 engage the release harnesses 108 of the locking mechanism 106 to lock and unlock the locking mechanism 106 as previously described. The lock lines 92 may engage the release harnesses 108 in various arrangements, examples of which are illustrated in FIGS. 53A-53C . In each embodiment, two lock line lumens 340 are present within the shaft 302 of the delivery catheter 300 terminating at the nose 318 . The lumens 340 are disposed on alternate sides of the actuator rod 64 so that each lumen 340 is directed toward a release harness 108 .
[0199] FIG. 53A illustrates an embodiment wherein two lock lines 92 , 92 ′ pass through a single lock line lumen 340 and are threaded through a release harness 108 on one side of the actuator rod 64 (the actuator rod 64 is shown without surrounding housing such as coupling structure, for clarity). The lock lines 92 , 92 ′ are then separated so that each lock line passes on an opposite side of the actuator rod 64 . The lock lines 92 , 92 ′ then pass through the release harness 108 ′ on the opposite side of the actuator rod 64 and continue together passing through a another single lock line lumen 340 ′. This lock line arrangement is the same arrangement illustrated in FIG. 48 .
[0200] FIG. 53B illustrates an embodiment wherein one lock line 92 passes through a single lock line lumen 340 , is threaded through a release harness 108 on one side of the actuator rod 64 , and is returned to the lock line lumen 340 . Similarly, another lock line 92 ′ passes through another single lock line lumen 340 ′, is threaded through a different release harness 108 ′ located on the opposite side of the actuator rod 64 , and is returned to the another single lock line lumen 340 ′.
[0201] FIG. 53C illustrates an embodiment wherein both lock lines 92 , 92 ′ pass through a single lock line lumen 340 . One lock line 92 is threaded through a release harness 108 on one side of the actuator rod 64 and is then passed through another lock line lumen 340 ′ on the opposite side of the actuator rod 64 . The other lock line 92 ′ is threaded through another release harness 108 ′ on the other side of the actuator rod 64 ′ and is then passed through the another lock line lumen 340 ′ with the previous lock line 92 .
[0202] It may be appreciated that a variety of lock line arrangements may be used and are not limited to the arrangements illustrated and described above. The various arrangements allow the harnesses 108 to be manipulated independently or jointly, allow various amounts of tension to be applied and vary the force required for removal of the lock lines when the fixation device is to be left behind. For example, a single lock line passing through one or two lumens may be connected to both release harnesses for simultaneous application of tension.
[0203] D. Proximal Element Line Arrangements
[0204] As mentioned previously, when proximal element lines 90 are present, the lines 90 pass through at least one proximal element line lumen 342 between the proximal element line handle 312 and at least one proximal element 16 . The proximal element lines 90 engage the proximal elements 16 to raise or lower the element 16 as previously described. The proximal element lines 90 may engage the proximal elements 16 in various arrangements, examples of which are illustrated in FIGS. 54A-54B . In each embodiment, two proximal element line lumens 342 are present within the shaft 302 of the delivery catheter 300 terminating at the nose 318 . The lumens 342 are disposed on alternate sides of the actuator rod 64 (the actuator rod 64 is shown without surrounding housing such as coupling structure, for clarity) so that each lumen 342 is directed toward a proximal element 16 .
[0205] FIG. 54A illustrates an embodiment wherein one proximal element line 90 passes through a single proximal element line lumen 342 . The proximal element line 90 is threaded through an eyelet 360 of a proximal element 16 on one side of the actuator rod 64 , passes over the actuator rod 64 and is threaded through an eyelet 360 ′ of another proximal element 16 ′ on the other side of the actuator rod 64 . The proximal element line 90 then passes through another single proximal element line lumen 342 ′. This proximal element line arrangement is the same arrangement illustrated in FIG. 48 .
[0206] FIG. 54B illustrates an embodiment wherein one proximal element line 90 passes through a single proximal element line lumen 342 , is threaded through an eyelet 360 of a proximal element 16 on one side of the actuator rod 64 , and is returned to the proximal element line lumen 342 . Similarly, another proximal element line 90 ′ passes through another single proximal element line lumen 342 ′ on the opposite side of the actuator rod 64 , and is returned to the another single proximal element line lumen 342 ′.
[0207] It may be appreciated that a variety of proximal element line arrangements may be used and are not limited to the arrangements illustrated and described above. The various arrangements allow the proximal elements to be manipulated independently or jointly, allow various amounts of tension to be applied and vary the force required for removal of the proximal element lines when the fixation device is to be left behind. For example, a single proximal element line passing through one or two lumens in shaft 302 may be used for simultaneous actuation of both proximal elements.
[0208] E. Main Body of Handle
[0209] FIG. 55 illustrates an embodiment of the handle 304 of the delivery catheter 300 . As mentioned previously, the actuator rod handle 316 , actuator rod control 314 , proximal element line handle 312 and lock line handle 310 are all joined with the main body 318 . The handle 304 further includes a support base 306 connected with the main body 308 . The main body 308 is slideable along the support base 306 to provide translation of the shaft 302 and the main body 308 is rotateable around the support base 306 to rotate the shaft.
[0210] FIG. 56 provides a partial cross-sectional view of the main body 308 of the handle 304 depicted in FIG. 55 . As shown, the main body 308 includes a sealed chamber 370 within which the actuator rod 64 , proximal element lines 90 and lock lines 92 are guided into the shaft 302 . The sealed chamber 370 is in fluid communication with the inner lumen 348 of shaft 302 and is typically filled with saline and flushed with heparin or heparinized saline. The sealed chamber 370 has a seal 372 along its perimeter to prevent leakage and the introduction of air to the chamber 370 . Any air in the chamber 370 may be bled from the chamber 370 by one or more luers 374 which pass through the main body 308 into the chamber 370 as illustrated in FIG. 55 . In this embodiment, the handle 304 includes two such luers 374 , one on each side of the main body 308 (second luer symmetrically positioned on backside of main body 308 in FIG. 55 , hidden from view). Referring now to FIG. 56 , the sealed chamber 370 also has various additional seals, such as an actuator rod seal 376 which surrounds the actuator rod 64 where the actuator rod 64 enters the sealed chamber 370 , and a shaft seal 378 which surrounds the shaft 302 where the shaft 302 enters the sealed chamber 370 .
[0211] F. Lock Line Handle and Proximal Element Line Handle
[0212] As mentioned previously, the lock lines 92 may be may be extended, retracted, loaded with various amounts of tension or removed using the lock line handle 310 . Likewise, the proximal element lines 90 may be extended, retracted, loaded with various amounts of tension or removed using the proximal element line handle 312 . Both of these handles 310 , 312 may be similarly designed to manipulate the appropriate lines 90 , 92 passing therethrough.
[0213] FIG. 57 illustrates an embodiment of a lock line handle 310 having lock lines 92 passing therethrough. The lock line handle 310 has a distal end 384 , a proximal end 382 and an elongate shaft 383 therebetween. The distal end 382 is positionable within the sealed chamber 370 so that the proximal end 382 extends out of the chamber 370 , beyond the main body 308 . The free ends of the lock lines 92 are disposed near the proximal end 382 , passing through the wall of the handle 310 near a threaded nub 390 . The handle 310 further includes a cap 388 which is positionable on the nub 309 . Internal threading with the cap 388 mates with the threading on the threaded nub 390 so that the cap 388 holds the free ends of the lock lines 92 between the cap 388 and the nub 390 and/or other portions of the handle 310 by friction. The lock lines 92 pass through a central lumen (not shown) of the elongate shaft 383 , extend through the sealed chamber 370 (as shown in FIG. 56 ) and extend through the shaft 302 to the locking mechanism 106 .
[0214] Disposed near the distal end 384 of the handle 310 is at least one wing 392 . In the embodiment of FIG. 57 , two wings 392 are present, each wing 392 disposed on opposite sides of the elongate shaft 383 . The wings 392 extend radially outwardly and curve proximally so that a portion is parallel to the elongate shaft 383 , as shown. It may be appreciated that the wings 392 may alternatively have the shape of solid or continuous protrusions which extend radially and have a portion which is parallel to the elongate shaft 383 . The wings 392 are used to hold the lock line handle 310 in a desired position which in turn holds the lock under a desired load of tension, as will be described further below. The handle 310 also includes a finger grip 386 near the proximal end 382 which extends radially outwardly in alignment with the radial extension of the at least one wing 392 . Thus, the user may determine the orientation of the wings 392 within the sealed chamber 370 from the orientation of the finger grip 386 outside of the main body 308 . The finger grip 386 may also serve an ergonomic purpose to assist in manipulating the handle 310 .
[0215] The portion of the wings 392 parallel to the elongate shaft 383 have grooves or serrations 394 . The serrations 394 are used to apply tension to the lock lines 92 . As shown in FIG. 57A , the lock line handle 310 is positioned within a semi-tube 400 which is disposed within the sealed chamber 370 . The semi-tube 400 comprises a top half 402 and a bottom half 404 , each half 402 , 404 having grooves or serrations 406 which mate with the serrations 394 of the wings 392 . Thus, when the wings 392 are rotated to mate the serrations 394 , 406 , as shown in FIG. 58A , the elongate shaft 383 is held in place. Likewise, the wings 392 may be rotated, as shown in FIG. 58B , so that the wings 392 are disposed between the halves 402 , 404 and the serrations 394 , 406 are disengaged. In this position, the shaft 383 may be translated to apply or release tension in the lock lines 92 . Thus, tension in the lines 92 may be adjusted by rotating the shaft 383 to disengage the serrations 394 , 406 , translating the shaft 383 and then rotating the shaft 383 back to reengage the serrations 394 , 406 . Alternatively, the finger grip 386 may be pulled to apply tension to the lock lines 92 . Pulling the finger grip 386 translates the lock line handle 310 within the semi-tube 400 . Such translation is achievable due to angling of the serrations 394 , 406 and flexibility of wings 382 . However, the angling of the serrations 394 , 406 prevents translation in the opposite direction, i.e. by pushing the finger grip 386 . Therefore, to release tension from the lock lines 92 , the shaft 383 is rotated to disengage the serrations 394 , 406 , allowing translation of the shaft 383 , and then the shaft 383 is rotated back to reengage the serrations 394 , 406 .
[0216] To remove the lock lines 92 , the cap 388 is removed from the threaded nub 390 exposing the free ends of the lock lines 92 . If one lock line 92 is present having two free ends, continuous pulling on one of the free ends draws the entire length of lock line 92 out of the catheter 300 . If more than one lock line 92 is present, each lock line 92 will have two free ends. Continuous pulling on one of the free ends of each lock line 92 draws the entire length of each lock line 92 out of the catheter 300 .
[0217] It may be appreciated that the proximal element line handle 312 has corresponding features to the lock line handle 310 and operates in the same manner as illustrated in FIGS. 57A , 58 A- 58 B. It may also be appreciated that other mechanisms may be used for manipulating the lock lines 92 and proximal element lines 90 , such as including buttons, springs, levers and knobs.
[0218] G. Actuator Rod Control and Handle
[0219] The actuator rod 64 may be manipulated using the actuator rod control 314 and the actuator rod handle 316 . FIG. 59 provides a cross-sectional view of a portion of the handle 304 which includes the actuator rod control 314 and the actuator rod handle 316 . The actuator rod handle 316 is located at the proximal end of the handle 314 . The actuator rod handle 316 is fixedly attached to the proximal end of the actuator rod 64 . The actuator rod 64 is inserted through a collet 426 which is disposed within a holder 428 as shown. The holder 428 has external threads 434 which mate with internal threads 432 of the actuator rod control 314 . Thus, rotation of the actuator rod control 314 causes the holder 428 to translate along the actuator rod control 314 by action of the threading, as will be described in more detail below. The actuator rod control 314 is rotatably coupled with the main body 308 of the handle 304 and is held in place by a lip 430 .
[0220] Referring to FIG. 59A , the actuator rod control 314 may be manually rotated in a clockwise or counter clockwise direction, as indicated by arrow 436 . Rotation of the actuator rod control 314 translates (extends or retracts) the actuator rod 64 to manipulate the distal elements 18 of the fixation device 14 . Specifically, rotation of the actuator rod control 314 causes the external threads 434 of the adjacent holder 428 to translate along the mated internal threads 432 of the actuator rod control 314 . Rotation of the holder 428 itself is prevented by holding pins 424 which protrude from the holder 428 and nest into grooves 438 in the main body 308 of the handle 304 . As the holder 428 translates, each holding pin 424 translates along its corresponding groove 438 . Since the collet 426 is attached to the holder 428 , the collet 426 translates along with the holder 428 . To simultaneously translate the actuator rod 64 , the actuator rod 64 is removably attached to the collet 426 by a pin 422 . The pin 422 may have any suitable form, including a clip-shape which partially wraps around the collet 426 as illustrated in FIG. 59 . Thus, rotation of the actuator rod control 314 provides fine control of translation of the actuator rod 64 and therefore fine control of positioning the distal elements 18 .
[0221] Referring to FIG. 59B , removal of the pin 422 , as shown, allows disengagement of the actuator rod handle 316 and fixedly attached actuator rod 64 from the collet 426 . Once disengaged, the actuator rod 64 may be rotated, as indicated by arrow 440 , by manually rotating the actuator rod handle 316 . As described previously, rotation of the actuator rod 64 engages or disengages the threaded joiner 332 of the delivery catheter 300 from the threaded stud 74 of the fixation device 14 . This is used to attach or detach the fixation device 14 from the delivery catheter 300 . In addition, when the actuator rod 64 is in the disengaged state, the actuator rod 64 may optionally be retracted and optionally removed from the catheter 300 by pulling the actuator rod handle 316 and withdrawing the actuator rod 64 from the handle 304 .
[0222] Depending on the application, the location of the target site, and the approach selected, the devices of the invention may be modified in ways well known to those of skill in the art or used in conjunction with other devices that are known in the art. For example, the delivery catheter may be modified in length, stiffness, shape and steerability for a desired application. Likewise, the orientation of the fixation device relative to the delivery catheter may be reversed or otherwise changed. The actuation mechanisms may be changed to be driven in alternate directions (push to open, pull to close, or pull to open, push to close). Materials and designs may be changed to be, for example, more flexible or more rigid. And, the fixation device components may be altered to those of different size or shape. Further, the delivery catheter of the present invention may be used to deliver other types of devices, particularly endovascular and minimally invasive surgical devices used in angioplasty, atherectomy, stent-delivery, embolic filtration and removal, septal defect repair, tissue approximation and repair, vascular clamping and ligation, suturing, aneurysm repair, vascular occlusion, and electrophysiological mapping and ablation, to name a few. Thus, the delivery catheter of the present invention may be used for applications in which a highly flexible, kink-resistant device is desirable with high compressive, tensile and torsional strength.
V. Multi-Catheter Guiding System
[0223] A. Overview of Guiding System
[0224] Referring to FIG. 60 , an embodiment of a multi-catheter guiding system 1 of the present invention is illustrated. The system 1 comprises an outer guide catheter 1000 , having a proximal end 1014 , a distal end 1016 , and a central lumen 1018 therethrough, and an inner guide catheter 1020 , having a proximal end 1024 , distal end 1026 and central lumen 1028 therethrough, wherein the inner guide catheter 1020 is positioned coaxially within the central lumen 1018 of the outer guide catheter 1000 , as shown. The distal ends 1016 , 1026 of catheters 1000 , 1020 , respectively, are sized to be passable to a body cavity, typically through a body lumen such as a vascular lumen. Thus, the distal end 1016 preferably has an outer diameter in the range of approximately 0.040 in. to 0.500 in., more preferably in the range of 0.130 in. to 0.320 in. The central lumen 1018 is sized for the passage of the inner guide catheter 1020 ; the distal end 1026 preferably has an outer diameter in the range of approximately 0.035 in. to 0.280 in., more preferably 0.120 in to 0.200 in. The central lumen 1028 is sized for the passage of a variety of devices therethrough. Therefore, the central lumen 1028 preferably has an inner diameter in the range of approximately 0.026 in. to 0.450 in., more preferably in the range of 0.100 in. to 0.180 in.
[0225] FIG. 60 illustrates an interventional catheter 1030 positioned within the inner guide catheter 1020 which may optionally be included in system 1 , however other interventional devices may be used. The interventional catheter 1030 has a proximal end 1034 and a distal end 1036 , wherein an interventional tool 1040 is positioned at the distal end 1036 . In this embodiment, the interventional tool 1040 comprises a detachable fixation device or clip. Optionally, the interventional catheter 1030 may also include a nosepiece 1042 having a stop 1043 , as shown. The stop 1043 prevents the interventional tool 1040 from entering the central lumen 1028 of the inner guide catheter 1020 . Thus, the interventional catheter 1030 may be advanced and retracted until the stop 1043 contacts the distal end 1026 of the inner guiding catheter 1020 preventing further retraction. This may provide certain advantages during some procedures. It may be appreciated that in embodiments which include such a stop 1043 , the interventional catheter 1030 would be pre-loaded within the inner guide catheter 1020 for advancement through the outer guiding catheter 1000 or both the interventional catheter 1030 and the inner guiding catheter 1020 would be pre-loaded into the outer guiding catheter 1000 for advancement to the target tissue. This is because the stop 1043 prevents advancement of the interventional catheter 1030 through the inner guiding catheter 1020 .
[0226] The outer guide catheter 1000 and/or the inner guide catheter 1020 are precurved and/or have steering mechanisms, embodiments of which will be described later in detail, to position the distal ends 1016 , 1026 in desired directions. Precurvature or steering of the outer guide catheter 1000 directs the distal end 1016 in a first direction to create a primary curve while precurvature and/or steering of the inner guide catheter 1020 directs distal end 1026 in a second direction, differing from the first, to create a secondary curve. Together, the primary and secondary curves form a compound curve. Advancement of the interventional catheter 1030 through the coaxial guide catheters 1000 , 1020 guides the interventional catheter 1030 through the compound curve toward a desired direction, usually in a direction which will allow the interventional catheter 1030 to reach its target.
[0227] Steering of the outer guide catheter 1000 and inner guide catheter 1020 may be achieved by actuation of one or more steering mechanisms. Actuation of the steering mechanisms is achieved with the use of actuators which are typically located on handles connected with each of the catheters 1000 , 1020 . As illustrated in FIG. 60 , handle 1056 is connected to the proximal end 1014 of the outer guide catheter 1000 and remains outside of the patient's body during use. Handle 1056 includes steering actuator 1050 which may be used to bend, are or reshape the outer guide catheter 1000 , such as to form a primary curve. Handle 1057 is connected to the proximal end (not shown) of the inner guide catheter 1020 and may optionally join with handle 1056 to form one larger handle, as shown. Handle 1057 includes steering actuator 1052 which may be used to bend, arc or reshape the inner guide catheter 1020 , such as to form a secondary curve and move the distal end 1026 of the inner guide catheter 1020 through an angle theta, as will be described in a later section.
[0228] In addition, locking actuators 1058 , 1060 may be used to actuate locking mechanisms to lock the catheters 1000 , 1020 in a particular position. Actuators 1050 , 1052 , 1058 , 1060 are illustrated as buttons, however it may be appreciated that these and any additional actuators located on the handles 1056 , 1057 may have any suitable form including knobs, thumbwheels, levers, switches, toggles, sensors or other devices. Other embodiments of the handles will be described in detail in a later section.
[0229] In addition, the handle 1056 may include a numerical or graphical display 1061 of information such as data indicating the position the catheters 1000 , 1020 , or force on actuators. It may also be appreciated that actuators 1050 , 1052 , 1058 , 1060 and any other buttons or screens may be disposed on a single handle which connects with both the catheters 1000 , 1020 .
[0230] B. Example Positions
[0231] FIGS. 61A-61D illustrate examples of positions that the catheters 1000 , 1020 may hold. Referring to FIG. 61A , the outer guide catheter 1000 may be precurved and/or steered into a position which includes a primary curve 1100 . The primary curve 1100 typically has a radius of curvature 1102 in the range of approximately 0.125 in. to 1.000 in., preferably in the range of approximately 0.250 in. to 0.500 in. or forms a curve in the range of approximately 0° to 120°. As shown, when the position includes only a primary curve 1100 , the distal end 16 lies in a single plane X. An axis x, transversing through the center of the central lumen 18 at the distal end 16 , lies within plane X.
[0232] Referring to FIG. 61B , the inner guide catheter 1020 extends through the central lumen 1018 of the outer guide catheter 1000 . The inner guide catheter 1020 may be precurved and/or steered into a position which includes a secondary curve 1104 . The secondary curve 1104 typically has a radius of curvature 10600 in the range of approximately 0.050 in. to 0.750 in., preferably in the range of approximately 0.125 in. to 0.250 in. or forms a curve in the range of approximately 0° to 180°. The secondary curve 1104 can lie in the same plane as the primary curve 1100 , plane X, or it can lie in a different plane, such as plane Z as shown. In this example, plane Z is substantially orthogonal to plane X. Axis z, transversing through the center of the central lumen 1028 of the inner guide catheter 1020 at the distal end 1026 , lies within plane Z. In this example, axis x and axis z are at substantially 90 degree angles to each other; however, it may be appreciated that axis x and axis z may be at any angle in relation to each other. Also, although in this example the primary curve 1100 and the secondary curve 1104 lie in different planes, particularly in substantially orthogonal planes, the curves 1100 , 1104 may alternatively lie in the same plane.
[0233] Referring now to FIG. 61C , the inner guide catheter 1020 may be further manipulated to allow the distal end 1026 to move through an angle theta 1070 . The angle theta 1070 is in the range of approximately −180° to +180°, typically in the range of −90° to +90°, possibly in the range of −60° to +60°, −45° to +45°, −30° to +30° or less. As shown, the angle theta 1070 lies within a plane Y. In particular, axis y, which runs through the center of the central lumen 1028 at the distal end 1026 , forms the angle theta 1070 with axis z. In this example, plane Y is orthogonal to both plane X and plane Z. Axes x, y, z all intercept at a point within the central lumen 1028 which also coincides with the intersection of planes X, Y, Z.
[0234] Similarly, FIG. 61D illustrates movement of the distal end 1026 through an angle theta 1070 on the opposite side of axis z. Again, the angle theta 1070 is measured from the axis z to the axis y, which runs through the center of the central lumen 1016 at the distal end 1026 . As shown, the angle theta 1070 lies in plane Y. Thus, the primary curve 1100 , secondary curve 1104 , and angle theta 1070 can all lie in different planes, and optionally in orthogonal planes. However, it may be appreciated that the planes within which the primary curve 1100 , secondary curve 1104 and angle theta 1070 lie may be mutually dependent and therefore would allow the possibility that some of these lie within the same plane.
[0235] In addition, the outer guide catheter 1000 may be pre-formed and/or steerable to provide additional curves or shapes. For example, as illustrated in FIG. 62A , an additional curve 1110 may be formed by the outer guide catheter 1000 proximal to the primary curve 1100 . In this example, the curve 1110 provides lift or raises the distal end 1016 of the outer guide catheter 1000 , which in turn raises the distal end 1026 of the inner guide catheter 1020 . Such lifting is illustrated in FIG. 62B . Here, the system 1 is shown prior to lifting in dashed line wherein the axis y′ passes through the intersection of axis z and axis x′. After application of curve 1110 , the distal portion of the system 1 is lifted in the direction of axis z so that axis x′ is raised to axis x″ and axis y′ is raised to axis y″. This raises distal end 1026 to a desired height.
[0236] The articulated position of the multi-catheter guiding system 1 illustrated in FIGS. 61A-61D and FIGS. 62A-62B is particularly useful for accessing the mitral valve. FIGS. 63A-63D illustrate a method of using the system 1 for accessing the mitral valve MV. To gain access to the mitral valve, the outer guide catheter 1000 may be tracked over a dilator and guidewire from a puncture in the femoral vein, through the inferior vena cava and into the right atrium. As shown in FIG. 63A , the outer guide catheter 1000 may be punctured through a fossa F in the interatrial septum S. The outer guide catheter 1000 is then advanced through the fossa F and curved by the primary curve 1100 so that the distal end 1016 is directed over the mitral valve MV. Again, it may be appreciated that this approach serves merely as an example and other approaches may be used, such as through the jugular vein, femoral artery, port access or direct access, to name a few. Positioning of the distal end 1016 over the mitral valve MV may be accomplished by precurvature of the outer guide catheter 1000 , wherein the catheter 1000 assumes this position when the dilator and guidewire are retracted, and/or by steering of the outer guide catheter 1000 to the desired position. In this example, formation of the primary curve 1100 moves the distal end 1016 within a primary plane, corresponding to previous plane X, substantially parallel to the valve surface. This moves the distal end 1016 laterally along the short axis of the mitral valve MV, and allows the distal end 1016 to be centered over the opening O between the leaflets LF.
[0237] Referring to FIG. 63B , the inner guide catheter 1020 is advanced through the central lumen 1018 of the outer guide catheter 1000 and the distal end 1026 is positioned so that the central lumen 1028 is directed toward the target tissue, the mitral valve MV. In particular, the central lumen 1028 is to be directed toward a specific area of the mitral valve MV, such as toward the opening O between the valve leaflets LF, so that a particular interventional procedure may be performed. In FIG. 63B , the inner guide catheter 1020 is shown in a position which includes a secondary curve 1104 in a secondary plane, corresponding to previous plane Z. Formation of the secondary curve 1104 moves the distal end 1026 vertically and angularly between the commissures C, directing the central lumen 1028 toward the mitral valve MV. In this position an interventional device or catheter 1030 which is passed through the central lumen 1028 would be directed toward and/or through the opening O. Although the primary curve 1100 and the secondary curve 1104 may be varied to accommodate different anatomical variations of the valve MV and different surgical procedures, further adjustment may be desired beyond these two curvatures for proper positioning of the system 1 .
[0238] Referring to FIG. 63C , the distal end 1026 of the inner guide catheter 1020 may be positioned through an angle theta 1070 . This moves the distal end 1026 vertically and angularly through a theta plane, corresponding to previous plane Y. Movement of the distal end 1026 through the angle theta 1070 in either direction is shown in dashed line in FIG. 63B . Such movement can be achieved by precurvature and/or by steering of the catheter 1020 . Consequently, the central lumen 1028 can be directed toward the mitral valve MV within a plane which differs from the secondary plane. After such movements, the inner guide catheter 1020 will be in a position so that the opening of the central lumen 1028 at the end 1016 faces the desired direction. In this case, the desired direction is toward the center of and orthogonal to the mitral valve.
[0239] In some instances, it is desired to raise or lower the distal end 1026 so that it is at a desired height in relation to the mitral valve MV. This may be accomplished by precurvature and/or by steering of the outer guide catheter 1000 to form additional curve 1110 . Generally this is used to lift the distal end 1026 above the mitral MV wherein such lifting was illustrated in FIG. 62B .
[0240] When the curvatures in the catheters 1000 , 1020 are formed by steering mechanisms, the steering mechanisms may be locked in place by a locking feature. Locking can provide additional stiffness and stability in the guiding system 1 for the passage of interventional devices or catheters 1030 therethrough, as illustrated in FIG. 60 . The interventional catheter 1030 can be passed through the central lumen 1028 toward the target tissue, in this case the mitral valve MV. Positioning of the distal end 1026 over the opening O, as described above, allows the catheter 1030 to pass through the opening O between the leaflets LF if desired, as shown in FIG. 63D . At this point, any desired procedure may be applied to the mitral valve for correction of regurgitation or any other disorder.
[0241] C. Steering Mechanisms
[0242] As described previously, the curvatures may be formed in the catheters 1000 , 1020 by precurving, steering or any suitable means. Precurving involves setting a specific curvature in the catheter prior to usage, such as by heat setting a polymer or by utilizing a shape-memory alloy. Since the catheters are generally flexible, loading of the catheter on a guidewire, dilator obturator or other introductory device straightens the catheter throughout the curved region. Once the catheter is positioned in the anatomy, the introductory device is removed and the catheter is allowed to relax back into the precurved setting.
[0243] To provide a higher degree of control and variety of possible curvatures, steering mechanisms may be used to create the curvatures and position the catheters. In some embodiments, the steering mechanisms comprise cables or pullwires within the wall of the catheter. As shown in FIG. 64A , the outer guide catheter 1000 may include a pullwire 1120 slidably disposed in lumens within the wall of the catheter 1000 extending to the distal end 1016 . By applying tension to the pullwire 1120 in the proximal direction, the distal end 1016 curves in the direction of the pullwire 1120 as illustrated by arrow 1122 . Likewise, as shown in FIG. 64A , placement of the pullwire 1120 along the opposite side of the catheter 1000 will allow the distal end 1016 to curve in the opposite direction, as illustrated by arrow 1124 , when tension is applied to the pullwire 1120 . Thus, referring to FIG. 64C , diametrically opposing placement of pullwires 1120 within the walls of the catheter 1000 allows the distal end 1016 to be steered in opposite directions. This provides a means of correcting or adjusting a curvature. For example, if tension is applied to one pullwire to create a curvature, the curvature may be lessened by applying tension to the diametrically opposite pullwire. Referring now to FIG. 64D , an additional set of opposing pullwires 1120 ′ may extend within the wall of the catheter 1000 as shown. This combination of pullwires 1120 , 1120 ′ allows curvature of the distal end in at least four directions illustrated by arrows 1122 , 1124 , 1126 , 1128 . In this example, pullwires 1120 create the primary curve 1100 of the outer guide catheter 1000 and the pullwires 1120 ′ create the lift. It may be appreciated that FIGS. 64A-64D also pertain to the inner guide catheter 1020 . For example, in FIG. 64D , pullwires 1120 may create the secondary curve 1104 of the inner guide catheter 1020 and the pullwires 1120 ′ create the angle theta 1070 .
[0244] Such pullwires 1120 and/or pullwires 1120 ′ and associated lumens may be placed in any arrangement, singly or in pairs, symmetrically or nonsymmetrically and any number of pullwires may be present. This may allow curvature in any direction and about various axes. The pullwires 1120 , 1120 ′ may be fixed at any location along the length of the catheter by any suitable method, such as gluing, tying, soldering, or potting, to name a few. When tension is applied to the pullwire, the curvature forms from the point of attachment of the pullwire toward the proximal direction. Therefore, curvatures may be formed throughout the length of the catheter depending upon the locations of the points of attachment of the pullwires. Typically, however, the pullwires will be attached near the distal end of the catheter, optionally to an embedded tip ring 280 , illustrated in FIG. 64E . As shown, the pullwire 1120 passes through an orifice 286 in the tip ring 280 , forms a loop shape and then passes back through the orifice 286 and travels back up through the catheter wall (not shown). In addition, the lumens which house the pullwires may be straight, as shown in FIGS. 64A-64D , or may be curved.
[0245] D. Catheter Construction
[0246] The outer guide catheter 1000 and inner guide catheter 1020 may have the same or different construction which may include any suitable material or combination of materials to create the above described curvatures. For clarity, the examples provided will be in reference to the outer guide catheter 1000 , however it may be appreciated that such examples may also apply to the inner guide catheter 1020 .
[0247] In embodiments in which the catheter is precurved rather than steerable or in addition to being steerable, the catheter 1000 may be comprised of a polymer or copolymer which is able to be set in a desired curvature, such as by heat setting. Likewise, the catheter 1000 may be comprised of a shape-memory alloy.
[0248] In embodiments in which the catheter is steerable, the catheter 1000 may be comprised of one or more of a variety of materials, either along the length of the catheter 1000 or in various segments. Example materials include polyurethane, Pebax, nylon, polyester, polyethylene, polyimide, polyethylenetelephthalate(PET), polyetheretherketone (PEEK). In addition, the walls of the catheter 1000 may be reinforced with a variety of structures, such as metal braids or coils. Such reinforcements may be along the length of the catheter 1000 or in various segments.
[0249] For example, referring to FIG. 65A , the catheter 1000 may have a proximal braided segment 1150 , a coiled segment 1152 and distal braided segment 1154 . The proximal braided segment 1150 provides increased column strength and torque transmission. The coiled segment 1152 provides increased steerability. The distal braided segment 1154 provides a blend of steerability and torque/column strength. In another example, referring to FIG. 65B , the outer guiding catheter 1000 has a proximal double-layer braided segment 1151 and a distal braided segment 1154 . Thus, the proximal double-layer segment 1151 comprises a multi-lumen tube 1160 (having steering lumens 1162 for pullwires, distal ends of the steering lumens 1162 optionally embedded with stainless steel coils for reinforcement, and a central lumen 1163 ), an inner braided layer 1164 , and an outer braided layer 1166 , as illustrated in the cross-sectional view of FIG. 65C . Similarly, FIG. 65D provides a cross-sectional view of the distal braided segment 1154 comprising the multi-lumen tube 1160 and a single braided layer 1168 . In a further example, referring to FIG. 65E , the inner guiding catheter 1020 comprises a multi-lumen tube 1160 without reinforcement at its proximal end, a single braided layer middle segment 1170 and a single braided layer distal segment 1171 . Each of the single braided layer segments 1170 , 1171 have a multi-lumen tube 1160 and a single layer of braiding 1168 , as illustrated in cross-sectional view FIG. 65F . However, the segments 1170 , 1171 are comprised of polymers of differing durometers, typically decreasing toward the distal end.
[0250] FIG. 65G illustrates an other example of a cross-section of a distal section of an outer guiding catheter 1000 . Here, layer 1130 comprises 55D Pebax and has a thickness of approximately 0.0125 in. Layer 1131 comprises a 30 ppi braid and has a thickness of approximately 0.002 in. by 0.0065 in. Layer 1132 comprises 55D Pebax and has a thickness of approximately 0.006 in. Layer 1133 comprises 30 ppi braid and has a thickness of approximately 0.002 in by 0.0065 in. And finally, layer 1134 comprises Nylon 11 and includes steering lumens for approximately 0.0105 in. diameter pullwires 1120 . Central lumen 1163 is of sufficient size for passage of devices.
[0251] FIGS. 65H-65I illustrate additional examples of cross-sections of an inner guiding catheter 1020 , FIG. 65I illustrating a cross-section of a portion of the distal end and FIG. 65I illustrating a cross-section of a more distal portion of the distal end. Referring to FIG. 65H , layer 1135 comprises 40D polymer and has a thickness of approximately 0.0125 in. Layer 1136 comprises a 30 ppi braid and has a thickness of approximately 0.002 in. by 0.0065 in. Layer 1137 comprises 40D polymer and has a thickness of approximately 0.006 in. Layer 1138 comprises a 40 D polymer layer and has a thickness of approximately 0.0035 in. And finally, layer 1139 comprises a 55D liner. In addition, coiled steering lumens are included for approximately 0.0105 in. diameter pullwires 1120 . And, central lumen 1163 is of sufficient size for passage of devices. Referring to FIG. 65I , layer 1140 comprises a 40D polymer, layer 1141 comprises a 35D polymer, layer 1142 comprises a braid and layer 1143 comprises a liner. In addition, coiled steering lumens 1144 are included for pullwires. And, central lumen 1163 is of sufficient size for passage of devices.
[0252] FIGS. 66A-66C illustrate an embodiment of a keying feature which may be incorporated into the catheter shafts. The keying feature is used to maintain relationship between the inner and outer guide catheters to assist in steering capabilities. As shown in FIG. 66A , the inner guide catheter 1020 includes one or more protrusions 1400 which extend radially outwardly. In this example, four protrusions 1400 are present, equally spaced around the exterior of the catheter 1020 . Likewise, the outer guide catheter 1000 includes corresponding notches 1402 which align with the protrusions 1400 . Thus, in this example, the catheter 1000 includes four notches equally spaced around its central lumen 1018 . Thus, the inner guide catheter 1020 is able to be translated within the outer guide catheter 1000 , however rotation of the inner guide catheter 1020 within the outer guide catheter 1000 is prevented by the keying feature, i.e. the interlocking protrusions 1400 and notches 1402 . Such keying helps maintain a known correlation of position between the inner guide catheter 1020 and outer guide catheter 1000 . Since the inner and outer guide catheters 1020 , 1000 form curvatures in different directions, such keying is beneficial to ensure that the compound curvature formed by the separate curvatures in the inner and outer guide catheters 1020 , 1000 is the compound curvature that is anticipated. Keying may also increase stability wherein the curvatures remain in position reducing the possibility of compensating for each other.
[0253] FIG. 66B illustrates a cross-sectional view of the outer guiding catheter 1000 of FIG. 66A . Here, the catheter 1000 includes a notched layer 1404 along the inner surface of central lumen 1018 . The notched layer 1404 includes notches 1402 in any size, shape, arrangement and number. Optionally, the notched layer 1404 may include lumens 1406 , typically for passage of pullwires 1120 . However, the lumens 1406 may alternatively or in addition be used for other uses. It may also be appreciated that the notched layer 1404 may be incorporated into the wall of the catheter 1000 , such as by extrusion, or may be a separate layer positioned within the catheter 1000 . Further, it may be appreciated that the notched layer 1404 may extend the entire length of the catheter 1000 or one or more portions of the length of the catheter 1000 , including simply a small strip at a designated location along the length of the catheter 1000 .
[0254] FIG. 66C illustrates a cross-sectional view of the inner guiding catheter 1020 of FIG. 66A . Here, the catheter 1020 includes protrusions 1400 along the outer surface of the catheter 1020 . The protrusions 1400 may be of any size, shape, arrangement and number. It may be appreciated that the protrusions 1400 may be incorporated into the wall of the catheter 1020 , such as by extrusion, may be included in a separate cylindrical layer on the outer surface of the catheter 1020 , or the protrusions 1400 may be individually adhered to the outer surface of the catheter 1020 . Further, it may be appreciated that the protrusions 1400 may extend the entire length of the catheter 1000 or one or more portions of the length of the catheter 1020 , including simply a small strip at a designated location along the length of the catheter 1020 .
[0255] Thus, the keying feature may be present along one or more specific portions of the catheters 1000 , 1020 or may extend along the entire length of the catheters 1000 , 1020 . Likewise, the notches 1402 may extend along the entire length of the outer guiding catheter 1020 while the protrusions 1400 extend along discrete portions of the inner guiding catheter 1000 and vice versa. It may further be appreciated that the protrusions 1400 may be present on the inner surface of the outer guiding catheter 1000 while the notches 1402 are present along the outer surface of the inner guiding catheter 1020 .
[0256] Alternatively or in addition, one or more steerable portions of the catheter 1000 may comprise a series of articulating members 1180 as illustrated in FIG. 67A . Exemplary embodiments of steerable portions of catheters comprising such articulating members 1180 are described in U.S. patent application Ser. No. 10/441,753 (Attorney Docket No. 020489-001200US) incorporated herein by reference for all purposes. FIG. 67B illustrates the outer guide catheter 1000 having a steerable portion comprising articulating members 1180 at its distal end 1016 .
[0257] Briefly, referring to FIG. 67A , each articulating member 1180 may have any shape, particularly a shape which allows interfitting or nesting as shown. In addition, it is desired that each member 1180 have the capability of independently rotating against an adjacent articulating member 1180 . In this embodiment, the articulating members 1180 comprise interfitting domed rings 1184 . The domed rings 1184 each include a base 1188 and a dome 1186 . The base 1188 and dome 1186 have a hollow interior which, when the domed rings 1184 are interfit in a series, forms a central lumen 1190 . In addition, the dome 1186 allows each articulating member 1180 to mate against an inner surface of an adjacent domed ring 1184 .
[0258] The interfitting domed rings 1184 are connected by at least one pullwire 1120 . Such pullwires typically extend through the length of the catheter 1000 and at least one of the interfitting domed rings 1184 to a fixation point where the pullwire 1120 is fixedly attached. By applying tension to the pullwire 1120 , the pullwire 1120 arcs the series of interfitting domed rings 1184 proximal to the attachment point to form a curve. Thus, pulling or applying tension on at least one pullwire, steers or deflects the catheter 1000 in the direction of that pullwire 1120 . By positioning various pullwires 1120 throughout the circumference of the domed rings 1184 , the catheter 1000 may be directed in any number of directions.
[0259] Also shown in FIG. 67A , each interfitting domed ring 1184 may comprise one or more pullwire lumens 1182 through which the pullwires 1120 are threaded. Alternatively, the pullwires 1120 may be threaded through the central lumen 1190 . In any case, the pullwires are attached to the catheter 1000 at a position where a desired curve is to be formed. The pullwires 1120 may be fixed in place by any suitable method, such as soldering, gluing, tying, welding or potting, to name a few. Such fixation method is typically dependent upon the materials used. The articulating members 1180 may be comprised of any suitable material including stainless steel, various metals, various polymers or co-polymers. Likewise the pullwires 1120 may be comprised of any suitable material such as fibers, sutures, metal wires, metal braids, or polymer braids.
[0260] E. Handles
[0261] As mentioned previously, manipulation of the guide catheters 1000 , 1020 is achieved with the use of handles 1056 , 1057 attached to the proximal ends of the catheters 1000 , 1020 . FIG. 68 illustrates a preferred embodiment of handles 1056 , 1057 . As shown, handle 1056 is attached to the proximal end 1014 of outer guide catheter 1000 and handle 1057 is attached to the proximal end 1024 of inner guide catheter 1020 . Inner guide catheter 1020 is inserted through handle 1056 and is positioned coaxially within outer guide catheter 1000 . In this embodiment, the handles 1056 , 1057 are not linked together as shown in the embodiment illustrated in FIG. 60 . It may be appreciated that such handles 1056 , 1057 may alternatively be connected by external connecting rods, bars or plates or by an additional external stabilizing base. An embodiment of a stabilizing base will be described in a later section. Referring back to FIG. 68 , interventional catheter is inserted through handle 1057 and is positioned coaxially within inner guide catheter 1020 and outer guide catheter 1000 .
[0262] Each handle 1056 , 1057 includes two steering knobs 1300 a , 1300 b emerging from a handle housing 1302 for manipulation by a user. Steering knobs 1300 a are disposed on a side of the housing 1302 and steering knobs 1300 b are disposed on a face of the housing 1302 . However, it may be appreciated that such placement may vary based on a variety of factors including type of steering mechanism, size and shape of handle, type and arrangement of parts within handle, and ergonomics to name a few.
[0263] FIG. 69 illustrates the handles 1056 , 1057 of FIG. 68 with a portion of the housing 1302 removed to reveal the assemblies of the handles. Each knob 1300 a , 1300 b controls a steering mechanism which is used to form a curvature in the attached catheter. Each steering mechanism includes a hard stop gear assembly 1304 and a friction assembly 1306 . Tension is applied to one or more pullwires by action of the hard stop gear assembly to form a curve in a catheter. Tension is maintained by the friction assembly. When tension is released from the one or more pullwires the catheter returns to a straightened position.
[0264] FIG. 70 illustrates steering mechanisms within a handle wherein the housing 1302 is removed for clarity. Here, steering knob 1300 a is attached to a hard stop gear assembly 1304 and a friction assembly (not in view) and steering knob 1300 b is attached to a separate hard stop gear assembly 1304 and friction assembly 1306 . Steering knob 1300 a is attached to a knob post 1318 which passes through a base 1308 , terminating in a knob gear wheel 1310 . The knob gear wheel 1310 actuates the hard stop gear assembly 1304 , thereby applying tension to one or more pullwires 1120 .
[0265] The knob gear wheel 1310 is a toothed wheel that engages a disk gear wheel 1312 . Rotation of the steering knob 1300 a rotates the knob post 1318 and knob gear wheel 1310 which in turn rotates the disk gear wheel 1312 . Rotation of the disk gear wheel 1312 applies tension to one or more pullwires extending through the attached catheter, in this example the outer guiding catheter 1000 . As shown, the outer guiding catheter 1000 passes through the base 1308 , wherein one or more pullwires 1120 extending through the catheter 1000 are attached to the disk 1314 . Such attachment is schematically illustrated in FIG. 71 . Catheter 1000 is shown passing through base 1308 . A pullwire 1120 passing through a steering lumen 1162 in the catheter 1000 emerges from the wall of the catheter 1000 , passes through an aperture 1320 in the disk 1314 and is attached to an anchor peg 1316 on the disk 1314 . Rotation of the disk 1314 (indicated by arrow 1328 ) around disk post 1315 by action of the disk gear wheel 1312 , applies tension to the pullwire 1120 by drawing the pullwire 1120 through the aperture 1320 and wrapping the pullwire 1120 around the disk 1314 as it rotates. Additional rotation of the disk 1314 applies increasing tension to the pullwire 1120 . To limit the amount of tension applied to the pullwire 1120 , to limit curvature of the catheter and/or to avoid possible breakage of the pullwire 1120 , the rotation of the disk 1314 may be restricted by hard stop peg 1322 which is attached to the disk 1314 and extends into the base 1308 .
[0266] FIGS. 72A-72B illustrate how the hard stop peg 1322 is used to restrict rotation of disk 1314 . FIGS. 72A-72B provide a top view, wherein the disk 1314 is disposed on the base 1308 . The anchor peg 1316 is shown with the pullwire 1120 thereattached. A groove 1326 is formed in the base 1308 beneath the disk 1314 and forms an arc shape. The hard stop peg 1322 extends from the disk 1314 into the groove 1326 in the base 1308 . Referring now to FIG. 72B , rotation of the disk 1314 around knob post 1318 , indicated by arrow 1330 , draws the pullwire 1120 through the aperture 1320 as previously described, wrapping the pullwire 1120 around the disk 1314 . As the disk 1314 rotates, the hard stop peg 1322 follows along the groove 1326 , as shown. The disk 1314 continues rotating until the hard stop peg 1322 reaches a hard stop 1324 . The hard stop 1324 is positioned in the groove 1326 and prevents further passage of the hard stop peg 1322 . Thus, disk 1314 rotation may be restricted to any degree of rotation less than or equal to 360 degrees by positioning of the hard stop 1324 .
[0267] In some instances, it is desired to restrict rotation of the disk 1314 to a degree of rotation which is more than 360 degrees. This may be achieved with another embodiment of the hard stop gear assembly 1304 . Referring now to FIGS. 73A-73B , a portion of such a hard stop gear assembly 1304 is shown. FIG. 73A illustrates the base 1308 and the disk post 1315 positioned therethrough. Also shown in the base 1308 is an aperture 1334 through which the knob post 1318 , knob gear wheel 1310 and friction assembly 1306 pass, and a passageway 1336 through which the catheter 1000 passes. In this embodiment of the hard stop gear assembly 1304 , a groove 1326 is also present in an arc shape around the disk post 1315 , however a ball 1332 is positioned in the groove 1326 rather than a hard stop peg 1322 . Disk 1314 is positioned over the groove 1326 and the ball 1332 as shown in FIG. 73B . The disk 1314 , illustrated in FIG. 73C , has a groove 1356 in its surface which is positioned adjacent to the base 1308 , the groove 1356 having an arc shape similar to the groove 1326 in the base 1308 . The ball 1332 is not fixedly attached to the base 1308 or the disk 1314 and is therefore free to move along the channel formed by the groove 1326 in the base 1308 and the groove in the disk 1314 .
[0268] FIGS. 74A-74F illustrate how rotation of the disk 1314 may be restricted by the ball 1332 to a degree of rotation which is more than 360 degrees. FIGS. 74A-74F illustrate the groove 1326 in the base 1308 wherein the groove 1326 has an arc shape around disk post 1315 . The groove 1326 does not form a complete circle; a first groove end 1350 a and a second groove end 1350 b form a wall which prevent passage of the ball 1332 . It may be appreciated that the groove ends 1350 a , 1350 b may be any distance apart, shortening the length of the groove 1326 by any amount, and allowing the ball 1332 movement, and hence catheter deflection, to be adjusted to any desired amount. To begin, referring to FIG. 74A , the ball 1332 is positioned within the groove 1326 near the first groove end 1350 a . The disk 1314 has a matching groove 1352 (shape illustrated in dashed line) including a first groove end 1354 a and a second groove end 1354 b . The disk 1314 is positioned over the ball 1332 so that the ball 1332 is near the second groove end 1354 b.
[0269] Referring now to FIG. 74B , the disk 1314 may be rotated while the ball 1332 remains in place. Here, the disk 1314 has rotated 90 degrees, as indicated by arrow 36000 and the position of the groove ends 1354 a , 1354 b . Referring now to FIG. 74C , the disk 1314 may be further rotated while the ball 1332 remains in place. Here, the disk 1314 has rotated 270 degrees, as indicated by arrow 36000 and the position of the groove ends 1354 a , 1354 b . The disk 1314 may continue rotating to 360 degrees, as shown in FIG. 74D , indicated by arrow 36000 . Here, the first groove end 1354 a in the disk 1314 has contacted the ball 1332 and pushes the ball 1332 along groove 1326 in the base. Referring now to FIG. 74E , the disk 1314 may be further rotated while the ball 1332 is pushed along the groove 1326 in the base 1308 by the first groove end 1354 a in the disk 1314 . Here, the disk 1314 is shown to have rotated 540 degrees. Referring to FIG. 74F , the disk 1314 rotates until the ball 1332 reaches the second groove end 1350 b of the base 1308 , providing a hard stop. In this position, the ball 1332 is held between the first groove end 1354 a of the disk 1314 and the second groove end 1350 b of the base 1308 and further rotation of the disk 1314 is prevented. Thus, the disk 1314 was rotated approximately 660 degrees in this example. Any maximum degree of rotation may be set by positioning of groove ends 1350 a , 1350 b and/or groove ends 1354 a , 1354 b . Additionally, in some embodiments, rotation can be limited by adding more than one ball 1332 to the groove 1326 , for example, two, three, four, five, six, seven, eight, nine, ten or more balls may be used to limit travel and hence curvature.
[0270] It may be appreciated that one or more pullwires 1120 are attached to the disk 1314 in a manner similar to that illustrated in FIG. 71 . Therefore, as the disk 1314 rotates, around disk post 1315 by action of the disk gear wheel 1312 , tension is applied to the pullwire 1120 by drawing the pullwire 1120 through the aperture 1320 and wrapping the pullwire 1120 around the disk 1314 as it rotates. Additional rotation of the disk 1314 applies increasing tension to the pullwire 1120 . Restriction of rotation as described above limits the amount of tension applied to the pullwire 1120 , to limit curvature of the catheter and/or to avoid possible breakage of the pullwire 1120 .
[0271] As mentioned, each steering mechanism includes at least a hard stop gear assembly 1304 and a friction assembly 1306 . As described above, tension is applied to one or more pullwires by action of the hard stop gear assembly to form a curve in a catheter. Tension is maintained by the friction assembly. FIG. 75 illustrates an embodiment of a friction assembly 1306 . The friction assembly 1306 essentially holds a steering knob, in this example steering knob 1300 b , and the associated knob post 1318 in a rotated position. Here, rotation of the knob 1300 b and post 1318 rotates attached knob gear wheel 1310 . The knob gear wheel 1310 actuates the hard stop gear assembly 1304 , thereby applying tension to one or more pullwires 1120 . The knob gear wheel 1310 is a toothed wheel that engages a disk gear wheel 1312 . Rotation of the steering knob 1300 b rotates the knob post 1318 and knob gear wheel 1310 which in turn rotates the disk gear wheel 1312 . Rotation of the disk gear wheel 1312 applies tension to one or more pullwires extending through the attached catheter, in this example the outer guiding catheter 1000 .
[0272] The steering knob 1300 b and knob post 1318 are held in a rotated position by friction provided by a frictional pad 1370 . The frictional pad 1370 is positioned between ring 1372 attached to the knob post 1318 and a plate 1374 attached to the base 1308 . The knob post 1318 extends from the knob 1300 b through the ring 1372 , the frictional pad 1370 and then the plate 1374 . The plate 1374 has internal threads which mate with threads on the knob post 1318 . As the knob post 1318 rotates, the threads on the post 1318 advance through the threads on the plate 1374 . This draws the ring 1372 closer to the plate 1374 , compressing the frictional pad 1370 therebetween. Frictional pad 1370 may be comprised of any O-ring or sheet material with desirable frictional and compressibility characteristics, such as silicone rubber, natural rubber or synthetic rubbers, to name a few. In preferred embodiments, an EPDM rubber O-ring is used. Reverse rotation of the knob post 1318 is resisted by friction of the frictional pad 1370 against the ring 1372 . The higher the compression of the frictional pad 1370 the stronger the frictional hold. Therefore, as the steering knob 1300 b is rotated and increasing amounts of tension are applied to the pullwires 1120 , increasing amounts of friction are applied to the ring 1372 to hold the knob 1300 b in place.
[0273] Manual reverse rotation of the steering knob 1300 b releases tension on the pullwires 1120 and draws the ring 1372 away from the plate 1374 thereby reducing the frictional load. When tension is released from the pullwires 1120 the catheter 1000 returns toward a straightened position.
[0274] It may be appreciated that each handle 1056 , 1057 includes a steering mechanism for each curve to be formed in the attached catheter. Thus, as shown in FIG. 69 , handle 1056 includes a steering mechanism to form the primary curve 1100 in outer guiding catheter 1000 and a steering mechanism to form the additional curve 1110 . Likewise, handle 1057 includes a steering mechanism to form the secondary curve 1104 in inner guiding catheter 1020 and a steering mechanism to form the angle theta 1070 .
[0275] Some curves, such as the primary curve 1100 , secondary curve 1104 and additional curve 1110 each typically vary in curvature between a straight configuration and a curved configuration in a single direction. Such movement may be achieved with single set of a hard stop gear assembly 1304 and a friction assembly 1306 . However, other curves, such as the angle theta 1070 , may be formed in two directions as shown in FIGS. 61C-61D . Such movement is achieved with two sets of the hard stop gear assembly 1304 and the friction assembly 1306 , each set controlling curvature in a single direction.
[0276] FIG. 75 illustrates the presence of an additional set of the friction assembly 1306 ′. One or more pullwires 1120 ′, such as an opposing set as illustrated in FIG. 64D , extending within the wall of the catheter 1000 are attached to the disk 1314 ′ in the same manner as pullwires 1120 are attached to disk 1314 . The disks 1314 , 1314 ′ are arranged so that rotation of steering knob 1300 b in one direction applies tension to the pullwires 1120 via disk 1314 and rotation of steering knob 1300 b in the opposite direction applies tension to the pullwires 1120 ′ via disk 1314 ′. Likewise, the additional friction assembly 1306 ′ is shown having a ring 1372 ′ attached to the knob post 1318 and a frictional pad 1370 ′ disposed between the ring 1372 ′ and the opposite side of the plate 1374 . Therefore, as rotation of the steering knob 1300 b in the opposite direction applies tension to the pullwires 1120 ′ via disk 1314 ′, the frictional pad 1370 ′ applies tension to the ring 1372 ′ holding the knob post 1318 ′ in place.
[0277] It may be appreciated that various other mechanisms may be used for tensioning and holding pullwires 1120 in place. Example mechanisms that may alternatively be used include clutches, ratchets, levers, knobs, rack and pinions, and deformable handles, to name a few.
[0278] F. Interventional System
[0279] FIG. 76 illustrates an embodiment of an interventional system 3 of the present invention. An embodiment of the multi-catheter guiding system 1 of the present invention is shown comprising an outer guide catheter 1000 , having a proximal end 1014 and a distal end 1016 , and an inner guide catheter 1020 , having a proximal end 1024 and a distal end 1026 , wherein the inner guide catheter 1020 is positioned coaxially within the outer guide catheter 1000 , as shown. In addition, a hemostatic valve 1090 is disposed within handle 1056 or external to handle 1056 as shown to provide leak-free sealing with or without the inner guide catheter 1020 in place. The valve 1090 also prevents back bleeding and reduces the possibility of air introduction when inserting the inner guide catheter 1020 through the outer guide catheter 1000 . An example of a hemostatic valve 1090 is illustrated in FIG. 76A , however any suitable valve or hemostatic valve may be used to provide similar functions. In FIG. 76A , the valve 1090 has a first end 1091 , a second end 1092 and a lumen 1093 therethrough. The inner wall of lumen 1093 is preferably tapered toward end 1091 and may further include a plurality of tapered axial channels configured to receive the protrusions 1400 on the inner guide catheter 1020 . The first end 1091 is attached to the outer guide catheter 1000 and the second end 1092 is free. Referring now back to FIG. 76 , the distal ends 1016 , 1026 of catheters 1000 , 1020 , respectively, are sized to be passable to a body cavity, typically through a body lumen such as a vascular lumen.
[0280] To assist in inserting the fixation device 14 through a hemostatic valve 1090 , a fixation device introducer may be used. For example, when the fixation device 14 is loaded on a delivery catheter 300 and an inner guide catheter 1020 , insertion of the fixation device 14 , delivery catheter 300 and inner guide catheter 1020 through an outer guide catheter 1000 involves passing the fixation device 14 through a hemostatic valve 1090 on the outer guide catheter 1000 . To reduce any trauma to the fixation device 14 by the hemostatic valve 1090 , a fixation device introducer may be used. An embodiment of a fixation device introducer 1420 is illustrated in FIG. 76B . The introducer 1420 includes a loading body 1422 and an insertion endpiece 1424 . The fixation device 14 is loaded into the loading body 1422 and into the insertion endpiece 1424 to approximately the dashed line 1428 . The insertion endpiece 1424 has a split end creating individual split sections 1430 , in this embodiment, four split sections 1430 . By compressing the split sections 1430 , the endpiece 1424 forms a taper. Such a taper is then inserted through a hemostatic valve 1090 , so that the insertion endpiece 1424 creates a smooth passageway through the valve for the fixation device 14 . Once the insertion endpiece 1424 is inserted through the valve 1090 , the fixation device 14 , and attached delivery catheter 300 and inner guide catheter 1020 , may then be advanced through the fixation device introducer 1420 . The fixation device introducer 1420 also includes a hemostatic valve within the loading body 1422 to prevent any backbleeding or leakage through the introducer 1420 .
[0281] Manipulation of the guide catheters 1000 , 1020 is achieved with the use of handles 1056 , 1057 attached to the proximal ends of the catheters 1000 , 1020 . As shown, handle 1056 is attached to the proximal end 1014 of outer guide catheter 1000 and handle 1057 is attached to the proximal end 1024 of inner guide catheter 1020 . Inner guide catheter 1020 is inserted through handle 1056 and is positioned coaxially within outer guide catheter 1000 .
[0282] An embodiment of the delivery catheter 300 of the present invention is inserted through handle 1057 and is positioned coaxially within inner guide catheter 1020 and outer guide catheter 1000 . Therefore, a hemostatic valve 1090 is disposed within handle 1057 or external to handle 1057 as shown to provide leak-free sealing with or without the delivery catheter 300 in place. The valve 1090 functions as described above. The delivery catheter 300 includes a shaft 302 , having a proximal end 322 and a distal end 324 , and a handle 304 attached to the proximal end 322 . A fixation device 14 is removably coupled to the distal end 324 for delivery to a site within the body.
[0283] The outer guide catheter 1000 and/or the inner guide catheter 1020 are precurved and/or have steering mechanisms to position the distal ends 1016 , 1026 in desired directions. Precurvature or steering of the outer guide catheter 1000 directs the distal end 1016 in a first direction to create a primary curve while precurvature and/or steering of the inner guide catheter 1020 directs distal end 1026 in a second direction, differing from the first, to create a secondary curve. Together, the primary and secondary curves form a compound curve. Advancement of the delivery catheter 300 through the coaxial guide catheters 1000 , 1020 guides the delivery catheter 300 through the compound curve toward a desired direction, usually in a direction which will position the fixation device 14 in a desired location within the body.
[0284] FIG. 77 illustrates portions of another embodiment of an interventional system 3 of the present invention. Handles 1056 , 1057 of the multi-catheter guiding system 1 of the present invention are shown. Each handle 1056 , 1057 includes a set of steering knobs 1300 a , 1300 b , as shown. Manipulation of the guide catheters 1000 , 1020 is achieved with the use of the steering knobs 1300 a , 1300 b attached to the proximal ends of the catheters 1000 , 1020 . Handle 304 of the delivery catheter 300 is also shown, including the proximal element line handle 312 , the lock line handle 310 , the actuator rod control 314 and the actuator rod handle 316 , among other features. The handle 304 is supported by the support base 306 which is connected to the handle 1057 .
[0285] It may be appreciated the above described systems 3 are not intended to limit the scope of the present invention. The systems 3 may include any or all of the components of the described invention. In addition, the multi-catheter guiding system 1 of the present invention may be used to introduce other delivery catheters, interventional catheters or other devices. Likewise, the delivery catheter 300 may be introduced through other introducers or guiding systems. Also, the delivery catheter 300 may be used to deliver other types of devices to a target location within the body, including endoscopic staplers, devices for electrophysiology mapping or ablation, septal defect repair devices, heart valves, annuloplasty rings and others.
[0286] In addition, many of the components of the system 3 may include one or more hydrophilic coatings. Hydrophilic coatings become slippery when wet, eliminate the need for separate lubricants. Thus, such coatings may be present on the multi-catheter guiding system, delivery catheter, and fixation device, including the proximal elements and distal elements, to name a few.
[0287] Further, the system 3 may be supported by an external stabilizer base 1440 , an embodiment of which is illustrated in FIG. 78 . Stabilizer base 1440 maintains the relative positions of the outer guide, inner guide and delivery catheter during a procedure. In this embodiment, the base 1440 comprises a platform 1442 having a planar shape for positioning on or against a flat surface, such as a table or benchtop. The base 1440 further includes a pair of handle holders 1444 , 1448 , each attached to the platform 1442 and extending upwardly from the platform 1442 , either angularly or perpendicularly. Handle holder 1444 includes a notch 1446 for holding the outer guiding catheter 1000 , as illustrated in FIG. 79 , thereby supporting the handle 1056 . FIG. 79 shows the handle 1056 attached to the outer guiding catheter 1000 positioned so that the proximal end 1014 of the outer guiding catheter 1000 rests in the notch 1446 . Referring back to FIG. 78 , handle holder 1448 includes an elongate portion 1452 having a trough 1450 and a hooked end 1454 . As shown in FIG. 80 , handle 1057 rests on the elongate portion 1452 and the handle 304 rests on hooked end 1454 so that the inner guiding catheter 1020 extends from the handle 1057 to the handle 1056 and continues on within outer guiding catheter 1000 . The handle 304 is additionally supported by support base 306 , as shown.
[0288] It may be appreciated that the stabilizer base 1440 may take a variety of forms and may include differences in structural design to accommodate various types, shapes, arrangements and numbers of handles.
[0289] G. Kits
[0290] Referring now to FIG. 81 , kits 1500 according to the present invention comprise any of the components described in relation to the present invention. The kits 1500 may include any of the components described above, such as the outer guide catheter 1000 including handle 1056 , the inner guide catheter 1020 including handle 1057 , the delivery catheter 300 and the fixation device 14 and instructions for use IFU. Optionally, any of the kits may further include any other system components described above, such as various interventional tools 1040 , or components associated with positioning a device in a body lumen, such as a guidewire 1202 , dilator 1206 or needle 1204 . The instructions for use IFU will set forth any of the methods as described above, and all kit components will usually be packaged together in a pouch 1505 or other conventional medical device packaging. Usually, those kit components which will be used in performing the procedure on the patient will be sterilized and maintained within the kit. Optionally, separate pouches, bags, trays or other packaging may be provided within a larger package, where the smaller packs may be opened separately to separately maintain the components in a sterile fashion.
[0291] While the foregoing is a complete description of the preferred embodiments of the invention, various alternatives, substitutions, additions, modifications, and equivalents are possible without departing from the scope of the invention. For example, in many of the above-described embodiments, the invention is described in the context of approaching a valve structure from the upstream side—that is, the atrial side in the case of a mitral valve. It should be understood that any of the foregoing embodiments may be utilized in other approaches as well, including from the ventricular or downstream side of the valve, as well as using surgical approaches through a wall of the heart. Moreover, the invention may be used in the treatment of a variety of other tissue structures besides heart valves, and will find usefulness in a variety of tissue approximation, attachment, closure, clamping and ligation applications, some endovascular, some endoscopic, and some open surgical.
[0292] Again, although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that various alternatives, modifications and equivalents may be used and the above description should not be taken as limiting in scope of the invention which is defined by the appended claims. | The invention provides devices, systems and methods for tissue approximation and repair at treatment sites. The devices, systems and methods of the invention will find use in a variety of therapeutic procedures, including endovascular, minimally-invasive, and open surgical procedures, and can be used in various anatomical regions, including the abdomen, thorax, cardiovascular system, heart, intestinal tract, stomach, urinary tract, bladder, lung, and other organs, vessels, and tissues. The invention is particularly useful in those procedures requiring minimally-invasive or endovascular access to remote tissue locations, where the instruments utilized must negotiate long, narrow, and tortuous pathways to the treatment site. In addition, many of the devices and systems of the invention are adapted to be reversible and removable from the patient at any point without interference with or trauma to internal tissues. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a method and device for checking at least one parameter at least partially conditioning the operation of an internal combustion engine with controlled ignition from detection of the flame front.
The present invention is particularly well adapted for controlling the richness of a fuel-oxydent mixture such as air fuel delivered to a control ignition engine, and particularly a weak mixture.
In fact, at the present time, there exist few means for controlling the correct operation of a control ignition engine fed with weak mixture and particularly for controlling the combustion stability thereof and, consequently, the operating stability.
The present invention may also provide a control means for controlling the rate of recycling the exhaust gases.
SUMMARY OF THE INVENTION
Thus, the present invention provides a method for adjusting at least one parameter conditioning at least partially the operation of a controlled ignition internal combustion engine. According to this method, the passage of the flame front in the combustion chamber of at least one cylinder is detected, and the angular divergence between an angular reference position and the angular position at which detection of the flame front occurs is determined. From the distribution or histogram coming from several of the angular divergences corresponding to a predetermined number of cycles n, a magnitude is elaborated or determined for controlling the operation of the engine and the parameter is modified conditioning the operation of the motor so that the control magnitude takes on a predetermined value.
The predetermined number of cycles may, for example, be equal to 32 or 64 cycles.
The parameter at least partially conditioning the operation of the engine may be related to the richness of the fuel-oxydent mixture delivered to the engine.
The magnitude for controlling the operation of the engine may correspond to the evolution of at least one of the following values:
the mean value of said angular divergence;
the typical divergence or variance of the above defined mean;
the maximum value of the distribution of the angular divergences;
the value of the distribution of the angular divergences for a given crankshaft angle;
the angular spread of the distribution of the angular divergences;
the value of the angle beyond which a fixed number of detections of the flame front is made.
The angular reference position may correspond to the moment of energization of the spark plug.
When the method of invention is applied to an engine having several cylinders, the parameter for each of the cylinders may be adjusted from detection of the flame front in one and the same cylinder.
Similarly, this parameter may be adjusted for each of the cylinders from detection of the flame front in each of the cylinders respectively.
The present application also provides a device for implementing the method of the invention. This device comprises at least one ionization probe, means for measuring the angular divergence and means for statistically processing the angular divergence.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and its advantages will be clear from the following description of examples, more particularly adapted to adjusting the richness of the air-petrol mixture delivered to a control ignition engine.
FIG. 1 shows the cylinder of an engine equipped with an ionization probed,
FIG. 2 shows one example of distirbution of the angular divergences, and
FIGS. 3A to 3E show the evolution of the angular distribution curve as a function of the evolution of the fuel-oxydent richness.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the example chosen, for a cylinder or considered cylinder, and for each cycle thereof, the angular divergences measured between a reference position corresponding to the moment of energization of the sparkplug of the cylinder, or moment of ignition of the considered cylinder, and the detection of the passage of a flame front at a predetermined position in the combustion chamber where a probe is placed for detecting the flame front, such as a ionization probe, a very low inertia temperature sensor, etc.
As shown in FIG. 1 an engine comprises a cylinder 1 which cooperates with a piston 2 connected to the crankshaft 3 by a connection rod 4.
The combustion chamber 5 of this cylinder comprises a sparkplug 6 and an ionization probe 7, with the ionization probe 7 detecting the flame front schematized at 8, the zone 9 corresponds to the burnt mixture portion.
References 10, 11, 12 and 13 designate respectively the intake pipe, the butterfly valve controlling the flow of gas penetrating into the engine, fuel injection and the intake valve.
Reference 14 designates the high voltage wire for supplying spark plug 6 which is connected to the ignition system 17. This system delivers the moment of ignition to computing and control means 18.
Reference 15 designates the cable detecting the passage of the flame front 8. The detection signal is transmitted to computing and control means possibly via analog pulsating means 19 integrated in the computing and control means 18.
The means for detecting the flame front 8 as well as the means for detecting the angular position 20 and measuring the angular divergences will not be described in the present application, since they are well-known to a man skilled in the art. Reference may be made to the French patent applications FR-2.337.261 and FR-2.432.097.
From the acquisition of the ignition times and detection of the flame front 8 by the ionization probe 7, it is easy to calculate the propagation time of the flame front 8 between the spark plug 6 and the ionization probe or the angular divergence. For the same operating point of the engine, the distribution of this angular divergence over a certain number of consecutive cycles of the same cylinder 1 may be plotted on a graph. FIG. 2 shows one example of such distribution over 32 consecutive cycles, this distribution being referenced from the ignition time A1. It is recalled that the detection contemplated is defined by the first angle of appearance of the flame front 8 in line with the ionization probe 7. The angular divergence is plotted as abscissa in crankshaft degrees and the percentage of appearance in ordinates. Line 16 in the graph of FIG. 2 shows the distirbution of the angular divergences. The value M represents the mean angular divergence and the value of segment E, the typical divergence. In FIGS. 3A to 3E, the distributions are shown obtained with constant engine torque, as a function of the richness of the fuel/oxydent mixture. The respective richnesses shown in FIGS. 3A to 3E are: 0.98; 0.91; 0.81; 0.75; 0.66.
In FIGS. 3A to 3E, the reference A1 indicates the moment of ignition; references M and E the mean and the typical divergence, respectively.
It can be seen in these figures that as the richness decreases, the distribution of the angular divergences is offset towards the increasing abscissa, as was observed for numerous loads and speeds.
Similarly, it can be seen that the maximum point decreases as the richness decreases.
It will also be noted that the typical divergence E increases whereas the richness decreases.
It will also be noted that the distribution of the angular divergences spreads out more and more when the richness decreases.
In effect, in FIG. 3A, the distribution occupies fifteen crankshaft degrees or so, whereas, in FIG. 3E it occupies about thirty crankshaft degrees.
Thus, it is clear from the distribution of the angular divergences that several magnitudes may be elaborated for taking into account the operating conditions of the engine.
Thus, among the magnitudes which may be used, the following may be mentioned:
1. Evolution of the mean value of the distribution of the probe signals (M),
2. Evolution of the typical divergence of the above defined mean (E),
3. Evolution of the maximum value of the disbribution of the probe signals (A MAXI),
4. Evolution of the value of the distribution of the probe signals (expressed in detection percentage for example) at certain fixed angles, for example 40°, corresponding to the frequency for a given angle.
5. Evolution of the angular spread of the distribution of the probe signals,
6. Evolution of the angle (the origin being the moment of ignition) beyond which a fixed number of detections appears, for example, evolution of the angle beyond which there is appearance of one and only one detection.
It can thus be noted that the possibilities of choosing a criterion become numerous. In fact, all sorts of combinations of the evolutions of the different parameters as well as of their statistical elements, may be imagined. As a first step, the variation of a single parameter may be chosen which will possibly be completed by other information, if necessary, during tuning of the engine.
The last magnitude numbered 6 offers good sensitivity of the detection, in particular by taking into account the angular divergence beyond which there is appearance of a single detection.
Good results have been obtained with this configuration by fixing an angular window at 75° of the crankshaft from the moment of ignition with a distribution over 32 successive cycles.
By angular window is meant the angular interval beginning at the ignition time or angle and which ends or is closed at a given crankshaft angle or, which is equivalent, which has a given angular amplitude, in the preceding example it is a question of an angular amplitude of 75°.
This configuration may be used by defining an angular window following tuning tests and then adjusting the richness so that, for example, over 32 successive detections there is only a single one which is outside.
If there is none, the mixture may be weakened, if there are several it will need to be made richer.
This is in no wise limiting and the number of detections made beyond a given angular window may be different from 1.
Tests have given satisfactory results, particularly, by considering 6 detections for an angular window of 60°. Furthermore, such a configuration makes it possible to better appreciate the discrepancy of the actual operating parameters of the engine with respect to the desired adjustments and to obtain these rapidly. Thus, if the number of detections beyond the angular window of 60° is zero, the engine adjustment may be varied rapidly (for example, so as to considerably weaken the mixture delivered to the engine). From the first detection beyond this angular window, the speed of adjusting the engine will be reduced (for example, the mixture will weakened more slowly) so as to better control the approximation of the desired adjustment parameters.
So as to avoid pumping phenomena about the desired operating points of the engine, intervals or ranges of values may be introduced, for example, over the number of detections, the angular windows thus introducing a hysteresis effect.
Thus, in the example mentioned above, it may be considered that the desired adjustment is reached if between four and six detections appear after the angular window of 60° of crankshaft, or for example if six detections were obtained after one at least of the angular windows whose closure is between 58 and 62° of the crankshaft.
The method of the present invention may be implemented by using electronic components, for example by means of a microprocessor of the "Monochip Intel 8751 H type".
Tests have shown that the signals produced by the ionization probe 7 are degraded when the richness decreases and that the analog processing of these signals should be reduced to a minimum. It is recommended to use comparators.
Still within the scope of the present invention, the computing and control system may adjust simultaneously several operating parameters of the engine, for example, and without this being a limitation, the richness of the mixture delivered to the engine and the moment of ignition. | A method and device for adjusting at least one parameter conditioning at least partially the operation of an internal combustion engine with controlled ignition, this technique using the detection of the passage of the flame front in the combustion chamber. From the distribution or histogram based on several of these angular divergences corresponding to a predetermined number of cycles n, a magnitude is elaborated or determined for controlling the operation of the engine and the parameter conditioning the operation of the engine is modified so that the control magnitude takes on a predetermined value. | 5 |
This application is a continuation-in-part of non-provisional application Ser. No. 12/434,400 filed May 1, 2009. All prior applications are incorporated by reference in their entirety.
FIELD OF THE INVENTION
The field of the invention is containers for semi-solid materials.
BACKGROUND
Americans currently produce more waste than any other nation in the world. Much of the waste comes from plastic and/or metal, which decomposes at a very slow rate. These materials must be recycled, dumped into the oceans or waterways, or deposited into landfills where they will remain for centuries.
In order to reduce the waste in our ever-filling landfills, it is advantageous to create containers that are biodegradable and/or compostable. U.S. Pat. No. 2,074,899 to Gazette teaches a container that is made entirely of paper, but that container is not entirely satisfactory. Gazette's paper container is neither air tight nor water tight, so that liquids or semi-solids stored in the container can spill or evaporate. In addition, even barring spilling or evaporation, Gazette's paper container can't hold liquids or semi-solid materials for an extended period of time since those materials would eventually saturate the paper container and leak out or dissolve parts of the container.
Gazette and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
EP1035025 to Lowry teaches a container having a body that is made substantially out of paper, but uses a thermoplastic cap to maintain a tight seal. Plastic caps, however, are not biodegradable and would still contribute to our landfill problems. Also, Lowry's container is similar to Gazette's container in that liquids or semi-solid materials would tend to saturate the container, and eventually leak out.
US2007/0110928 to Bried teaches a container with a wax coating on the inside of the container. However, wax coatings tend to dissolve in the presence of oil based contents, and in any event waxes are not necessarily biodegradable.
Thus, there is still a need for a sealed biodegradable container that holds liquids or semi-solid contents over a period of time.
SUMMARY OF THE INVENTION
The inventive subject matter provides apparatus, systems and methods in which a vessel has a fibrous outer wall (preferably a cardboard outer wall) with a lumen, and a fibrous inner wall disposed within the lumen of the outer wall. At least portions of the inner surfaces of each of the inner and outer walls include a permeation barrier material.
As used herein the term “vessel” means an object used as a container for solids, liquids and/or semi-solids. Semi-solids materials are both solid and liquid at room temperature. While semi-solids could be made of a single chemical composition where freezing point and the melting point are between 10 degrees Fahrenheit of room temperature, the semi-solid material is preferably a mix of solids and liquids.
As used herein “fibrous material” means materials characterized by a plurality of discrete fibers. The filaments can be plant or animal derived, synthetic, or some combination of these. In “plant-derived fibrous materials” the filaments are at least predominantly of plant origin, examples of which include wood, papyrus, rice, ficus, mulberry, fibers, cotton, yucca, sisal, bowstring hemp and New Zealand flax. Further, as used herein the term “fibrous wall” means a wall comprising a fibrous material as a significant structural constituent. The fibrous walls contemplated herein preferably have at least 2, 5, 10, 20 or even 30 dry weight percent of fibers. Preferably, the fibrous walls have at least 80 or 90 dry weight percent of fibers. Paper is generally a fibrous material that is usually made by pressing and de-watering moist fibers, typically cellulose pulp derived from wood rags, or grasses. Preferably, the fibrous material is rigid and is largely inflexible, as, for example, layered paper or corrugated cardboard. The structure of a fibrous material that is substantially rigid will tend to bend or break if a great deal of pressure is placed upon it, in contrast to a flexible material that will tend to flex and return back to its original shape after the pressure is released. Preferably, the walls, bottom, and cap are all rigid.
Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.
As used herein, a statement that a permeation barrier is “substantially impermeable” to oil and/or water means that a wall treated with that additive has a transfer rate of less than or equal to 50 μl of water and/or sunflower oil per cm 2 per six-month period of time at room temperature and normal atmospheric pressure (STP). Preferably, the permeation barrier material is substantially impermeable to both water and oil.
It is contemplated that permeation barriers could be applied to parts of the vessel prior to assembly, or even after assembly. In preferred embodiments, the walls comprise a rolled paper upon which an adhesive has been coated and/or impregnated. Such walls would typically include six to eight layers (wraps) of the paper/permeation barrier combination.
In a preferred embodiment, the permeation barrier comprises an adhesive, which term is used herein to mean any compound in a liquid or semi-liquid state used to adheres or bonds items together. Prior to use, adhesives can be pastes (very thick) or glues (relatively fluid). All suitable adhesives are contemplated, including for example Elmer's™ Glue (polyvinyl acetate), or in a very simple case a glue made from milk powder and vinegar. Other suitable permeation barrier materials include those disclosed in U.S. Pat. No. 7,344,784 to Hodson or US20050130261 to Wils.
The outer wall can be made of any suitable fibrous material, preferably biodegradable and preferably comprises paper, cardboard, or fiberboard. Wrapped materials seem to have the best strength and cost characteristics. The outer wall can advantageously define a lumen in which inner wall is disposed.
As used herein, a “biodegradable material” means a material that will break down to at least 90% H 2 0, C0 2 , and biomass within a period of six months from the action of naturally occurring micro-organisms such as bacteria, fungi, algae etc. under favorable conditions. For example, meat, plants, wood, cotton, polylactic acid polymers, and paper are all deemed herein to be biodegradable. In preferred embodiments, every element of the vessel, including the inner wall, the cap, the cover, the spacers, the bottoms, adhesives, and permeation barrier materials are biodegradable.
In preferred embodiments, the outer wall forms a cylinder, but could also be shaped to have polygonal, oval or other horizontal cross-sections. The outer wall could even form a cone, or be frustoconical, although from a manufacturing and distribution standpoint the horizontal cross-sections should be substantially the same from top to bottom. In an exemplary embodiment, the outer wall comprises a hollow cardboard tube. The outer wall could be any thickness, but is preferably within 1 mm to 10 mm thick.
The outer wall preferably has an open top and a closed bottom to form a cup. As used herein, the term “wall having an open top” means that the wall defines an opening that is ordinarily open during typical usage. Similarly, as used herein, the term “closed bottom” means that the wall defines a bottom that is ordinarily closed during typical usage. Under these definitions, an ordinary shampoo bottle is a vessel having a wall with an open top because the cap is either removed or disposed in an open position during typical usage. Also under these definitions, a Campbell's soup can with a pull tab top has a wall with an open top because the top is removed during typical usage. The bottom of such a soup can, however, is closed because the bottom is not removed during typical usage.
The outer wall and closed bottom could be made from a single piece of material, but preferably the closed bottom is a separate piece that fits within the lumen of the outer wall and sits on a movement restrictor formed by folding over a lower edge of the outer wall. The closed bottom could be flush with the bottom edge of the outer wall, but is more likely recessed from the bottom edge of the outer wall by at least 5, 10, 20, or 40 mm. In this instance, a commercially reasonable upper limit is thought to be about 30% of the height of the outer wall. Preferably, the closed bottom is located within 20, 10, 5, 3, or 2 mm from the bottom edge of the outer wall.
The movement restrictor can be coupled to the bottom of the outer wall in a variety of ways, including for example by gluing, using “teeth” or other detents, or by merely folding one or more edges of the outer wall inward to form a folded edge (i.e., “ledge”) upon which the closed bottom rests. As used herein, a “movement restrictor” is a device that limits a travel of an object in at least one direction.
In another embodiment, the closed bottom could be a separate cap that is sized and dimensioned to fit over the bottom end of the outer wall to create a bottom of the vessel, and could be held in position by a tight fitting, but is preferably mechanically attached (for example by using screw threads and pins) or is attached using an adhesive. A separate cap could also be sized and dimensioned to fit within the bottom end of the outer wall's lumen, and could be mechanically attached or attached using an adhesive to create a flushed or a recessed bottom. In the second scenario, the separate cap preferably serves as a support for a false (or upper) interior bottom.
The inner wall can also be made of any suitable fibrous material, preferably biodegradable and preferably comprises paper, cardboard, or fiberboard. Typically, one would use the same material as used for the outer wall, although this is not a requirement. The inner wall is very likely shaped similarly to the outer wall, but with a smaller height and width, so as to be disposed snugly within the lumen defined by the outer wall. Alternatively, the inner wall could be much smaller than the lumen, or have a different shape of horizontal cross-section (e.g. round versus hexagonal), and could be kept in place with spacers. While the inner wall is preferably a separate piece that is attached, glued, or otherwise affixed to the interior surface of the outer wall, the inner wall could merely be an extension of the outer wall, for example a carved ledge within a single block of wood.
The interior cavity that houses the semi-solid or liquid product material is generally defined by (a) the inner surface of the inner wall and (b) either the closed bottom of the outer wall or a false bottom that is located between the closed bottom and the open top. The height of the false bottom is most readily set by a spacer that is placed in between the false bottom and the closed bottom. A taller spacer can be used to shrink the volume of the interior cavity, or to provide a hidden pocket in the bottom of the vessel.
A cover can be used to enclose or partially enclose the upper side of the interior cavity, and the product material being stored therein. Ideally, the cover is sized and dimensioned to rest upon the top edge of the inner wall, and also to extend across the inner surfaces of the outer wall. Such a design can advantageously provide a substantially air and moisture-tight seal, preventing much of the product material from evaporating. A small handle could also be coupled to the cover to allow a user to easily remove and replace the cover at any time.
The bottom of the interior cavity, the underside of the cover, and the top edge of the inner wall all preferably include the permeation barrier material in one way or another to prevent the product material from seeping through.
Preferred containers are jars. As used herein the term “jar” means a vessel that is (1) no more than 20 cm tall; (2) has a closed bottom end; and (3) a mouth that is at least 3 cm wide (i.e., internal diameter) and/or is 0.3 to 2.5 times the greatest height of the vessel. Jars are usually cylindrical, but can also have horizontal cross-sections that are polygonal, oval, etc.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded view of a double walled biodegradable jar according to one embodiment.
FIG. 2 is a perspective view of the jar of FIG. 1 assembled into a single jar.
FIG. 3 shows a cross-sectional view of the jar of FIG. 2 .
FIG. 4 shows the jar of FIG. 2 with an optional cover and a cap.
FIG. 5 shows the top view of the jar of FIG. 4 , with the cover installed.
FIG. 6 shows a single-walled jar in accordance with another embodiment.
DETAILED DESCRIPTION
FIG. 1 illustrates an embodiment of an inventive jar 100 comprising an inner wall 110 , a first disc 120 , a spacer 130 , a second disc 140 , and outer wall 150 . The outer wall receives each of the second disc 140 , the spacer 130 , the first disc 120 , and the inner wall 110 in lumen 158 , respectively.
Outer wall 150 is a cylindrical hollow tube with inner diameter 152 approximately 7.1 cm, outer diameter 154 approximately 7.2 cm, and interior surface 156 . Outer wall 150 is composed essentially of a structural material (preferably rolled 20-40 pound paper) and a permeation barrier material, and could readily be constructed with a standard cardboard tube machine. Other structural materials could additionally or alternatively be used, including for example other types of biodegradable, fibrous material. The structural material could also be molded as opposed to being rolled. An adhesive is the currently most preferred permeation barrier material, but all other suitable materials are contemplated, as for example an oil- or water-based varnish.
The permeation barrier material could be utilized in any suitable manner. For example, the inner sides of the outer wall could be sprayed or otherwise coated with the permeation barrier material, or it can be impregnated into the structural material. Additionally or alternatively, the permeation barrier material (especially as an adhesive) could be applied to the sides of a paper before or as the paper is being rolled.
Since the top edge 153 of outer wall 150 would likely encounter some of the product material during use, it is contemplated that the top edge 153 could have some permeation barrier material. As with the rest of the outer wall 150 , the permeation barrier material could be impregnated into the structural material of the wall, or added as a coating.
Outer wall 150 has an inner diameter 152 that at least partially defines lumen 158 . In FIG. 1 , the inner diameter measures approximately 71 mm. The outer wall 150 has a thickness of about 1 mm, so that the outer diameter 154 of the outer wall 150 is approximately 74 mm. In other contemplated embodiments the inner and outer diameter thickness could be larger or smaller, and could have other suitable dimensions. Preferably, the outer wall 150 has a thickness of about at least 1 mm to provide adequate strength and durability.
As defined herein, an outer wall that “at least partially define a lumen” means that the inner lumen 158 could be wholly defined by the inner diameter of the outer wall, or could be defined by the inner diameter of the outer wall and another wall, for example the inner wall or an extension attached to the outer wall. In FIG. 1 , the lumen is defined by both the inner diameter of the outer wall and the inner diameter of the inner wall. As defined herein, a “lumen” is a hollow cavity in the vessel. At least one portion of an interior wall of the lumen faces another part of the interior wall of the lumen without any intervening material in between the interior walls.
Second disc 140 is preferably a disc that fits snugly within lumen 158 and rests upon a movement restrictor 151 (see FIG. 3 ) that prevents second disc 140 from sliding out the bottom of outer wall 150 . While second disc 140 is preferably a chipboard disc, although other biodegradable or fibrous materials could be used. Preferably, second disc 140 is a circle with a diameter substantially equal to inner diameter 152 . As defined herein, a “substantially equal” length or diameter is one that is within a 1 mm tolerance. This prevents second disc 140 from sliding around and helps to provide a tight seal in case semi-solid material 210 (see FIG. 2 ) leaks through the first disc and onto the second disc. Second disc could also be covered or impregnated with, or could otherwise include a permeation barrier material if desired. For marketing purposes, a bottom surface of second disc can be colored, corrugated, or have some other aesthetic design.
Spacer 130 is a short cardboard tube that separates the first disc 120 from the second disc 140 . Like second disc 140 , first disc 120 is also preferably a chipboard disc, although other biodegradable or fibrous materials could be used. While spacer 130 is shown as a tube that fits snugly with the lumen, spacer 130 could be any suitable size and shape that helps restrict movement between first disc 120 and second disc 140 . By placing a spacer in between first disc 120 and second disc 140 , the false bottom allows jar 100 to appear as though it has more semi-solid material than it really does. This could be advantageous from a marketing standpoint, in at least three ways: (1) to compete with plastic walled jars that often contain dead space to make the product appear larger than it really is; (2) to provide a larger label; and (3) to provide a chamber for free prizes or coupons.
Both spacer 130 and first disc 120 could include permeation barrier material. First disc 120 should have at least its top surface and edges impregnated or otherwise covered with the permeation barrier material, since first disc 120 acts as the bottom to the interior cavity where the semi-solid material is held. The rim of first disc 120 can also be glued to the interior surface 156 to prevent any semi-solid material from leaking through spaces or cracks between them.
Inner wall 110 is also a cylindrical hollow tube with inner diameter 114 , outer diameter 112 , inner surface 118 , and top edge 116 . Inner wall 110 , first disc 120 and cover 410 (see FIG. 4 ) define the interior cavity where the semi-solid or other product material is held. Preferably the inner wall is coupled to the outer wall using an adhesive, for example a sticky permeation barrier material.
The outer diameter 112 of inner wall 110 is configured to be juxtapose the inner diameter 152 of outer wall 150 . While inner wall 110 is shaped to match the shape of outer wall 150 , in alternative configurations (not shown) the inner wall could have any other suitable shape. Preferably, the difference between inner diameter 114 and outer diameter 112 (i.e., the thickness of inner wall 110 ) is at least 1 mm, but could also be at least 2 mm to allow for a larger “shelf” for a cover 410 (see FIG. 4 ) to rest upon.
In a manner similar to outer wall 150 , inner wall 110 includes a permeation barrier, as a coating, impregnated material, or in some other manner is also covered with the permeation barrier material and, Preferably, permeation barrier material is also included on top edge 116 to prevent the wall material from saturating if a user scrapes semi-solid material over the top edge 116 of inner wall 110 .
Some sort of glue preferably holds inner wall 110 against outer wall 150 , although other suitable coupling means could be used to join the walls together, including affixing inner wall to first disc 120 , or using a clamp. A spacer (not shown) could also be placed between inner wall 110 and outer wall 150 to provide a false side in much the same way spacer 130 provides a false bottom.
FIG. 2 shows an assembled jar 200 . From above, only outer wall 150 and inner wall 110 are visible, since the semi-solid or other product material 210 obscures a user's view.
Contemplated semi-solid product materials include facial cream, lotion, ice cream, yogurt, marzipan, lip balm, soft chocolate, soft cheese, ketchup, mustard, mayonnaise, relish, lemongrass, putty, caulk, wood filler, mosquito repellant, fire starters, boat leak paste, rosin, polish, or margarine spread. Typically, semi-solid or other product material 210 is either water or oil based, and could sometimes be both. As used herein, “oil” means any hydrophobic material that is liquid at room temperature. This includes, for example, petroleum, vegetable oil, butter, peanut butter, grease, and liquid animal fat. Liquids or solids could also be used in jar 200 as a product material, for example water, candy, cigarettes, spices, powdered drinks, protein powder, pins, tacks, screws, nails, jewelry, and pharmaceuticals.
A cross-sectional view of the assembled jar 200 is shown in FIG. 3 , where the inner wall 110 , first disc 120 , spacer 130 , second disc 140 , and movement restrictor 151 can be seen. In the current embodiment, movement restrictor 151 prevents second disc 140 from falling out the bottom of assembled jar 200 . Movement restrictor 151 could, for example, be a glue or a projection from the outer wall 150 . In the current embodiment, movement restrictor 151 is a rolled bottom edge of the outer wall 150 that projects inward towards the center of the tube.
FIG. 4 shows the assembled jar 200 with a cover 410 and a cap 420 . Cover 410 is similar to first disc 120 , but is much thicker and either has a hole 412 in the center or a tab 413 to be used in pulling up the cover 410 . Hole 412 and tab 413 are shown as exemplary handles that could be used to remove cover 410 from the vessel, but other suitable handles are contemplated. Other removal means are also contemplated, including for example a threaded cap, a loop, or some other projection or recess. Cover 410 is shaped and dimensioned to have a diameter smaller than the inner diameter 152 of outer wall 150 but larger than the inner diameter 112 of inner wall 110 . This allows cover 410 to rest upon top edge 116 of inner wall 110 and protect the semi-solid material 210 from evaporating or sublimating. While cover 410 is preferably circular, the cover could be shaped in any suitable manner. Preferably, the cover is sized and dimensioned to be just slightly larger than the lumen of the interior cavity of the inner wall so as to sit comfortably on top of the inner wall.
Since cover 410 directly abuts the top layer of semi-solid material 210 , very little of the semi-solid or other product material is exposed to open air. This creates a substantially air-tight seal around semi-solid material 210 so that the semi-solid material does not leak out of the jar or otherwise evaporate. The shelf-life of a semi-solid material could be increased tenfold, twentyfold, fiftyfold, or even a hundredfold using such a technique. In a preferred embodiment, the interior sides and the exterior sides of the cover, bottom, and walls are coated with the permeation barrier material to provide an even better seal. In another embodiment, all sides of each of the inner wall, outer wall, cover, cap, bottom, false bottom, and spacers are coated with the permeation barrier material.
After a user uses the product material, the user could replace cover 410 to re-seal the remaining product, especially with gels, greases or lotions that need to remain moist after use. Such a seal would tend to be facilitated by product material that might tend to collect on the top of the inner wall 110 . Alternatively, a user might choose to just throw away the cover 410 .
As shown in FIG. 5 , the thickness of top edge 116 is wide enough to allow cover 410 to rest upon top edge 116 without falling into the inner wall. In a preferred embodiment, the permeation barrier material is employed in a sufficiently effective manner such that water evaporates from within the product material at a rate of less than 5% every six months, and even more preferably less than 3% every six months. In one embodiment, an underside of cover 410 has a thin plastic membrane that creates a vacuum seal when the cover is placed over semi-solid material 210 .
Cap 420 is a paper cap that is sized and dimensioned to cover the top section of jar 200 , although other biodegradable materials are contemplated. While cap 420 could be threaded or could have an indent that matches a detent in jar 200 , cap 420 preferably just sits more or less snugly atop top of jar 200 . Cap could also have permeation material included on one or both sides to help prevent the semi-solid material from evaporating.
In FIG. 6 , a single-walled jar 600 has a wall 620 , a base 640 , and a cap 610 . Each of wall 620 , base 640 , and cap 610 are made of a biodegradable fibrous material, preferably paper, and has an exterior side and an interior side that include permeation barrier material. Including permeation barrier material in both the exterior surface and the interior surface of the walls and caps provides additional protection against the semi-solid material 630 evaporating or otherwise escaping an interior cavity of jar 600 . In this embodiment, the lumen of the single wall acts as an interior cavity to hold the semi-solid material 630 . The single-walled jar could otherwise be prepared similarly to jar 100 . For example, the single-walled jar 600 could have a cover (not shown) and a false bottom (not shown) formulated in a manner similar to jar 100 . Preferably, the single walled jar is substantially rigid.
It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. | A biodegradable jar has an enclosure wall with a cap that form ajar that holds a semi-solid material. In order to prevent the biodegradable wall from being weakened by the semi-solid material in the jar, both an exterior surface and an interior surface of the wall and the cap include a permeation barrier material that substantially prevents the semi-solid material from seeping through the walls of the jar. The enclosure wall could have an inner wall that is shorter than the outer wall which forms a ledge that a separate cover for the semi-solid material could rest upon. | 1 |
This is a divisional application of Ser. No. 162,454 filed Nov. 1, 1988 and now U.S. Pat. No. 4,909,050.
BACKGROUND OF THE INVENTION
This invention generally relates to garment cleaning apparatuses, and is specifically concerned with a water wash apparatus for both washing the garments worn by maintenance personnel in nuclear power facilities, and radioactively decontaminating them.
Machines for cleaning radioactively contaminated clothing are known in the prior art. Such prior art machines may use either a dry cleaning technique or a water wash technique to achieve the desired end. Of the two techniques, dry-cleaning with the use of fluorocarbon solvents such as freon is presently preferred over known water wash type machines due to the generally superior penetrating ability of fluorocarbon solvents. However, before the relative advantages and disadvantages of these two types of machines can be fully appreciated, some background as to the nature of the clothing cleaned and the environment wherein it is used is necessary.
Present-day nuclear power facilities require various maintenance and operating personnel to work in areas which may be contaminated with radioactive particles. To prevent these radioactive particles from coming into contact with the skin of such personnel, protective clothing in the form of frocks, hoods, and shoe coverings (known as "duck feet" in the art) are worn. After use, it is essential that the clothing be cleaned in such a way that removes substantially all of the radioactive particulates, and all or at least most of the conventional soils, sweats and body salts than can also accumulate therein. The removal of certain rare but highly radioactive particulates, such as the "fuel fleas" which can be generated by the cracking of a fuel rod, is particularly important as such particles are capable of exposing a small, pinpoint area of skin to a dangerous level of radioactivity. However, the cost of performing such a cleaning must be substantially less than the cost of replacing the garment if it is to be cost-effective. If the cost of cleaning approaches the cost of disposing of the old garment and replacing it with another, then garment replacement becomes preferable to garment cleaning.
Dry-cleaning techniques for cleaning such radioactively contaminated clothing are generally preferred over water wash techniques due to the inherently lower surface tension and hence generally superior penetrating ability of the fluorocarbons used in such techniques. While the use of such fluorocarbons has proven effective in removing substantially all of the radioactive particulates from such clothing, such dry-cleaning techniques are not without shortcomings. For example, the fluorocarbons used in such dry-cleaning techniques tend to dissolve the elastomers in certain synthetic rubbers that form parts of boots and other shoe coverings used in maintenance operations. The dissolution of these elastomers causes the synthetic rubbers to become brittle and crack, thereby damaging and ultimately destroying the particular article of clothing containing the synthetic rubber. Other materials used in protective gloves and shoes such as Neoprene® tend to soak up and absorb the fluorocarbons used until unacceptable levels of these fluorocarbons build up in the articles of clothing. While the excess fluorocarbons might be evaporated out of the clothing by the application of additional amounts of heat, such extra or protracted steps in the cleaning process adds to the overall expense of cleaning, and may tend to heat damage the plastic and rubber portions of the clothing, thereby defeating the purpose of the extra dry-out. Still another shortcoming associated with dry-cleaning techniques is the limited ability of fluorocarbons to dissolve sweat and body salts. While the fluorocarbons may succeed in removing substantially all of the radioactive particulates, the accumulation of such sweat and body salts will ultimately give the garment a cumulative "locker room" odor. Moreover, the fluorocarbons used in such dry-cleaning techniques presently cost about $13.00 per gallon, which is not an inconsiderable expense where many gallons are required. Finally, the fluorocarbons used in these techniques are limited (as are most organic solvents) in their ability to dissolve and remove radioactive contaminants in the form of metallic salt, such as cesium 137.
While wet washing techniques avoid many of the shortcomings associated with dry-cleaning techniques in that they are highly effective in dissolving and removing sweat and body salts as well as salts of cesium 137, they, too, have their drawbacks, the most serious being the generation of a water effluent which contains the radioactive particles removed from the clothing. The transportation and disposal of such an effluent significantly contributes to the cost of the wash notwithstanding the fact that the effluent qualifies as a low radiation level waste. While most nuclear facilities have on-site demineralizer systems which are capable of radioactively decontaminating such water, the inconveniences and expenses associated with the use such on-site demineralizer systems also add substantially to the overall cost of such prior art water wash techniques. Still another problem is the relatively lower efficiency of the water used in such systems in penetrating the fabrics that form such clothing and removing radioactive particulates. The relatively lower penetrating ability of water, coupled with the greater effort needed for dry-out due to its lower volatility as compared to freon, generally has the effect of increasing the time necessary to effectively water wash a contaminated garment.
Clearly, what is needed is an apparatus and method for cleaning radioactively contaminated clothing which removes all of the radioactive particulates, and cleans the clothing of sweat, body salts and radionucleide salts without damaging or destroying any of the synthetic rubbers or artificial fibers forming such clothing. Ideally, such an apparatus should be mobile to obviate the need for the transportation of radioactively contaminated garments, which would require the use of special containers and procedures. Finally, such an apparatus should be capable of quickly cleaning a large volume of such clothing at a cost which is substantially lower than the disposal and replacement costs of the garments being cleaned.
SUMMARY OF THE INVENTION
Generally speaking, the invention is both an apparatus and method for water washing garments and removing radioactive contaminates therefrom without the generation of liquid effluents. The apparatus generally comprises a washing machine for washing the garments which includes a wash water inlet, a rinse water inlet, a water outlet, a reservoir of surfactants and suspension agents. The apparatus also comprises a hydraulically closed wash water system that includes a reservoir of polished water connected to the wash water inlet of the washing machine, a particulate filtration unit connected to the outlet of the machine, and a water polishing unit connected between the filtration unit and the wash water inlet for resupplying the reservoir with filtered and polished water. The use of high-purity, polished water in combination with surfactants and suspension agents greatly improves the solvency and penetrating ability of the wash water, thus rendering it comparable in efficiency to known dry-cleaning solvents when the ability of such water to easily dissolve perspiration and salts is considered. Moreover, the generation of liquid effluents is avoided by the use of a hydraulically closed wash water system which recirculates and re-polishes the water while trapping radioactive particulates in filter units that utilize conveniently disposable cartridge-type filter members.
The wash water system may further include a wash water diverter conduit connected at one end between the filtration unit and the polisher, and at the other end directly to the wash water inlet of the washing machine. This conduit includes a valve for selectively diverting water which has been filtered by the filtration unit, but not yet polished by the polisher directly back into the washing machine during the initial washing cycles implemented by the apparatus, thereby avoiding the removal of any surfactants and suspension agents which were initially mixed into the wash water while at the same time protracting the life of the carbon and ion-exchange columns used in the wash water polisher.
The apparatus may further include a closed rinse water system connected between the outlet of the washing machine and the rinse water inlet. This rinse water system includes its own particulate filtration unit and polisher for removing any residual particulates and dissolved impurities in the rinse water discharged from the washing machine water outlet. To maintain the wash and rinse water systems in hydraulic isolation with one another, the apparatus preferably also includes a pair of valves for selectively connecting the washing machine outlet to the wash water system to the exclusion of the rinse water system, and vice versa. The provision of a hydraulically separate rinse water system insures that the last water to immerse the garments is of the purest form and highest quality.
The polisher of both the wash water system and the rinse water system each include a pair of polishing banks connected in parallel for reducing the pressure drop associated with such polishers. Each of the polishing banks preferably has a column of particulate carbon for removing dissolved gases and organic impurities, as well as a mixed cationic-ionic exchange column serially connected downstream from the carbon column. The polisher of the wash water system additionally includes a cationic exchange column and ionic exchange column serially connected between the column of particulate carbon and the mixed cationic-ionic column. In both the rinse and wash water polishers, isolation valves are provided for hydraulically isolating one or the other of the two polishing banks so that repairs may be made on one or the other of the banks without disrupting the operation of the apparatus.
To kill any microorganisms which may be present in the water flowing through the outlet of the washing machine, the outlet may be connected to an outlet conduit which includes an ultraviolet sanitizer. To prevent relatively large particles from clogging the filtration units of both the wash and rinse water systems, the outlet conduit may further include a bag-type filter.
Finally, the washing machine preferably includes a drum capable of spin-drying the garments fast enough to centrifugally remove at least 80% of all of the water absorbed therein. Such high-efficiency spin drying minimizes the number of wash and rinse cycles necessary to effectively clean the garments, and also minimizes the amount of make-up water which must be periodically added to the closed wash and rinse water systems to compensate for water losses.
BRIEF DESCRIPTION OF THE SEVERAL FIGURES
FIGS. 1A and 1B together form a hydraulic schematic diagram of the wash water apparatus of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
General Description Of The Apparatus And Method Of The Invention
With reference now to FIGS. 1A and 1B, the water wash apparatus 1 of the invention generally comprises a washing machine 3 having a wash water inlet 6, a rinse water inlet 8, an outlet conduit 12, and a surfactant and suspension agent supply reservoir 14. A hydraulically closed wash water system 64 is connected to the wash water inlet 6 at one end and the outlet conduit 12 at the other end. A hydraulically closed rinse water system 68 is connected between the rinse water inlet 8 and the outlet conduit 12. Solenoid operated check valves 62 and 66 connect the outlet conduit 12 of the washing machine 3 either to the wash water system 64 to the exclusion of the rinse water system 68, or vice versa.
The wash water system 64 includes a five-micron particulate filtration unit 74 serially connected upstream to a one-micron particulate filtration unit 76. A water polisher 93 is in turn connected downstream with respect to both filtration units 74 and 76. As will be described in detail hereinafter, most of the radioactive contaminants in the clothing being washed are in the form of particulates of which about 95% are captured by the filtration units 74 and 76. In order to conserve the surfactants and suspension agents which the supply reservoir 14 introduces into the washing machine 3 during the initial washing cycles, the wash water system 64 includes a diverter conduit 94 having a solenoid-operated valve 165. The diverter conduit 94 allows the operator of the apparatus to "short-circuit" water around the water polisher 93 and back into the washing machine 3 which has been filtered by filtration units 74 and 76, but which still contains surfactants and suspension agents by closing valve 96 (leading to the water polisher 93), and opening diverter conduit valve 165. Such operation and use of the diverter conduit 94 advantageously obviates the need for introducing surfactants and suspension agents to the wash water at the beginning of each wash, and further advantageously protracts the life of the various carbon and ion exchange columns of the water polisher 93.
The rinse water system 68 also contains a five-micron particulate filtration unit 190 which is serially connected to a one-micron particulate filtration unit 192. Downstream of these filtration units is a rinse water polisher 210 for insuring the purity of the rinse water circulated through the system 68. The use of polished water in both the wash and rinse water systems 64 and 68 significantly increases the solvency and hence washing effectiveness of the water. Because water from the rinse water system 68 is the last water to touch the garments in the washing machine 3, and because the wash water and rinse water system 64 and 68 are hydraulically isolated from one another, the apparatus insures that the last water to immerse the garments is of the highest quality.
Specific Description Of The Apparatus And Method Of The Invention
With reference again to FIGS. 1A and 1B, the washing machine 3 of the apparatus 1 includes an agitating and spin-dry drum 5 that is preferably capable of handling at least 50 pounds of garments or other fabrics. Additionally, wash and rinse water solenoid-operated intake valves 7 and 9 control the amount of wash or rinse water introduced into the washing machine 3 from either the wash water inlet 6 or the rinse water inlet 8. To control the amount of surfactants and suspension agents introduced into the machine 3, the reservoir 14 has an intake conduit 16 connected to the machine 3 which is provided with a solenoid-operated valve 18. Finally, the machine 3 includes a high-water pressure switch 19 for closing the wash and rinse water intake valves 7 and 9 when the water level of the machine 3 reaches a selected height. In the preferred embodiment, the washing machine 3 is a UNIWASH Model No. FB84/8610No.210 manufactured by D'Hooge, Inc. located in Ledeberg, Belgium. Such a machine is capable of not only thoroughly agitating any garments placed therein in order to effectively clean them, but is also capable of spin-drying the garments quickly enough to squeeze 82% of all the water absorbed therein during either a wash or a rinse cycle. This last feature is important, because it helps to prevent any residual radioactive particles from remaining in the clothing at the end of the wash cycle. It also minimizes the amount of make up water necessary to keep the apparatus 1 in operation.
The outlet conduit 12 includes on its upstream end a bag filter 21 for removing relatively large particles and pieces of debris from the wash or rinse water expelled from the machine 3. The removal of such large particles and chunks of debris not only avoids the fouling of the pumps 54 and 58 (to be described in more detail hereinafter), but further reduces the load on the particulate filtration units 74, 76, and 190, 192 of both the wash and rinse water systems 64 and 68. Located downstream of the bag filter 11 is a solenoid-operated drain valve 23. Unless indicated as being controlled by a pressure switch or some other local controller, all of the solenoid-operated valves in the apparatus 1 are controlled by a programmable central processor unit (not shown) having a timer which implements the method of the invention.
Downstream of the solenoid-operated drain valve 23 is the washer drain collecting tank 25. In the preferred embodiment, tank 25 is formed of stainless steel and has approximately a 30 gallon capacity. The tank 25 of outlet conduit 12 allows either wash water or rinse water to be rapidly drained from the washing machine 3. Such rapid draining facilitates effective cleaning of the garments within the machine 3 by helping to maintain all of the debris and particulate contaminants in suspension as the water is effectively dumped from the machine 3. By contrast, slow drainage would encourage such suspended debris and particulates to deposit themselves on the internal walls of the machine 3, thereby impairing the washing operation. The washer drain collecting tank 25 is provided with a gate-type drain valve 27 that is used when the entire apparatus 1 is drained-down incident to decommissioning, as well as high and low water pressure switches 29 and 31. These switches can actuate and deactuate a self-priming, single impeller pump 54 located downstream of the tank 25. Finally, the tank 25 includes a make-up water inlet 33 that is connected to both an internal make-up water supply 35 by way of a conduit 37 having a ball valve 39, as well as to an external make-up water supply 41 by way of another conduit 43 which extends through the wall 45 of a trailer which contains the apparatus 1. This last conduit 43 of the external make-up water supply 41 includes a serially connected ball valve 47, solenoid valve 49 and ball check valve 51 as indicated. The ball check valve 51 insures that no radioactively contaminated water from the washer drain collecting tank 25 can back up into the external makeup water supply 41.
While it is possible to introduce makeup water at other points in the apparatus 1, the connection of the internal and external makeup water supplies 35 and 41 to the washer drain collecting tank 25 has two advantages. First, because the tank 25 is hydraulically connectable via solenoid-operated valve 62 and 66 to either the wash water system 64 on the rinse water system 68, the hydraulic connection of the makeup water supplies 35 and 41 to the tank 25 allows a single makeup water tap-in to serve the make-up water needs of both the wash and rinse water systems 64 and 68. Secondly, the location of these makeup water supplies 35 and 41 upstream of the water polishers 93 and 210 of the wash and rinse water systems 64 and 68 allows the makeup water used to be undemineralized and unpolished if desired.
Located downstream of the washer drain collecting tank 25 is the previously mentioned self-priming, single impeller pump 54, as well as an ultraviolet sanitizer 56, and a high-pressure pump 58. Preferably, the high-pressure pump 58 is a staged impeller booster pump capable of generating between 55 to 60 pounds per square inch. Such pressure is necessary to push either the wash or the rinse water through the particulate filtration unit 74, 76 and 190, 192 of the wash and rinse water systems 64 and 68 in a reasonably short time. Such pumps are available from Webber Industrial, Inc., located in St. Louis, Mo. 63123, and are sold under the name "Webtrol." While such a staged impeller booster pump is safely capable of generating the pressures necessary for the expeditious circulation of the wash and rinse water in the apparatus 1 without rupturing or jeopardizing the integrity of the CPBC type of piping that is preferably used the conduits in the apparatus 1, it is unfortunately not self-priming. However, this problem is solved by the provision of the single impeller pump 54 located upstream. Pump 54 is capable of creating a pressure of approximately 15 to 20 pounds in the conduit 12, which in turn provides the necessary priming needed for pump 58.
The purpose of the ultraviolet sanitizer unit 56 is to kill any microorganisms which might be present in either the wash or rinse water drained cut of the tank 25. This is important, since such bacteria, fungi, and other microorganisms can lodge in the carbon and ion exchange columns of the polishers 93 and 210 and reproduce, thereby lowering quality of the wash and the the efficacy of the polishers 93 and 210 and accelerating the need for the replacement of columns. In the preferred embodiment, the ultraviolet sanitizer unit 56 (as well as all the other ultraviolet units used in apparatus 1) is either a Model No. UV8G478 or MP2-5L type unit manufactured by Aquafine Corp. for Cullingan. Aquafine Corporation is located in Valencia, Calif. 91355.
Located at the end of the outlet conduit 12 is a T intersection 61 which couples the washing machine outlet 11 to both the wash water system 64 and the rinse water system 68. As has been previously mentioned, solenoid-operated check valves 62 and 66 are provided on either side of the T intersection 61 for admitting water from the outlet conduit 12 to either the wash water system 64 to the exclusion of the rinse water system 68, and vice versa. As such, the solenoid-operated check valve 62 serves as an inlet valve to the wash water system 64, while valve 66 serves the same function with respect to the rinse water system 68.
With respect now to the wash water system 64, the previously mentioned five-micron and one-micron particulate filtration units 74 and 76 are located downstream of the inlet valve 62 as shown. The upstream location of the five-micron filtration unit relative to the one-micron filtration unit has the effect of extending the lifetime of the filtration element used in the one-micron filtration unit 76. In the preferred embodiment, disposal, cartridge-type filter elements (shown in phantom) are used in both of the filtration units 74 and 76 to expedite filter element changes. As has been previously indicated, such filtration units 74 and 76 have proven to be extremely effective in removing radioactive particulate contaminates from the wash water used in the apparatus 1, and together are responsible for approximately 95% of such particulate removal. Water sampling taps 77 and 79 regulated by needle valves 78 and 80 are provided in each of the particulate filtration units 74 and 76 for monitoring purposes. Additionally, pressure gauges 82, 84, and 86 are connected between the inlets and outlets of the particulate filtration units 74 and 76 so that the operator of the apparatus might readily ascertain when the cartridge filter elements used in the units have become saturated and need replacement. Finally, a pair of union ball valves 87 and 88 are disposed upstream and downstream of the particulate filtration units 74 and 76 to facilitate the assembly of the apparatus 1.
Located upstream of union ball valve 88 is T connection 90. One branch of the T connection 90 leads to water polisher conduit 92, which in turn flows into the water polisher 93, while the other branch of the T joint 90 is connected to the previously mentioned wash water diverter conduit 94. Solenoid-operated valves 96 and 165 are disposed at the inlet ends of both the water polisher conduit 92 and the diverter conduit 94, respectively.
Downstream of the solenoid-operated polisher inlet valve 96, the polisher conduit 92 bifurcates into two parallel conduits, 97a and 97b, each of which is hydraulically connected to separate polishing banks 100a and 100b of the polisher 93, respectively. Each of the polishing banks 100a and 100b includes a granulated carbon column 103a, 103b, a cation exchange 104a, 104b, an ion exchange column 106a, 106b, and mixed cation-anion exchange column 108a, 108b. In each of the banks 100a, 100b the granulated carbon column 102a, 102b serves to remove organic contaminates and dissolved gases, while the cation, ion and mixed exchange beds 104a, 104b, 106a, 106b and 108a, 108b each serve to remove dissolved radioactive nucleides from the wash water. Each of these columns preferably contains about three cubic feet of either particulate carbon or an appropriate ion exchange resin. Sampling taps 110a, 110b having needle valves 112a, 112b are provided between the various columns so that the water quality at every point within the polisher 93 may be monitored. To help the operator determine whether or not any flow-blocking stoppages have occurred at any point within the polisher 93, pressure gauges 114a, 114b and differential pressure gauges 115a, 115b are provided at the points indicated between the carbon and various ion exchange columns, as well as between the polishing banks 100a, 100b themselves. Finally, ohmic water quality sensors 116a, 116b are provided in the middle of each bank 100a, 100b for monitoring purposes. The use of two separate polishing banks 100a, 100b connected hydraulically in parallel advantageously lowers the back pressure that otherwise would exist across the polisher 93 if only serial connections were used. Moreover, because of the presenCe of isolation valves 119a, 119b and 120a, 120b both upstream and downstream in each of the separate polishing banks 100a, 100b, the polisher 93 is capable of operating during the repair or the replacement of any of the component parts of the banks 100a, 100b. This redundant capacity is an important advantage, as it avoids the need for a complete shut-down of the apparatus 1 whenever a particular column is repaired or replaced.
Downstream of the water polisher 93 is another union ball valve 122 for assembly purposes, an additional ohmic water quality sensor 124, and finally a wash water holding tank 126. The purpose of the wash water holding tank 126 is to "park" the filtered and polished water produced by the wash water system 64. High and low water switches 128 and 130 are provided in this wash water holding tank 126 for sounding high and low water alarms respectively. In the preferred embodiment, tank 126 has approximately 150 gallons of holding capacity, and serves as a reservoir of polished and filtered water for use in the washing machine 3. The tank 126 includes a water level indicator tube 132 which may be hydraulically isolated from the tank 126 by way of isolation valves 134a, 134b. For water quality monitoring purposes, the indicator tube 132 is also hydraulically connected to a water testing tap 136 having a needle valve 138. Tank 126 further has a fill port 140 for the addition of filtered and polished makeup water therein, as well as a gate-type drain valve 144 used during a general drain-down of the apparatus 1.
Located downstream of the wash water holding tank 126 is solenoid-operated valve 132 which controls the admission of wash water from the reservoir provided by the tank 126 into a single impeller, self-priming pump 146. For water testing purposes, pump 146 is hydraulically connected to a water sampling tap 147 by way of ball valve 148. The output of the pump 148 is connected to the water inlet 6 of the washing machine 3 by way of a second ultraviolet sanitizer 149 flanked by union ball valves 150a, 150b, a ball check valve 154, another union ball valve 156, and a solenoid-operated close-off valve 159. This last valve 159 prevents water that may have been contaminated in the washing machine 3 from backing up from the machine 3 into the purified water present in the wash water holding tank 126. An additional pressure gauge 162 is provided upstream of the water inlet 6 of the washing machine 3 so that the pressure and hence the flow rate of recycled wash water can be monitored.
Turning back to the wash water diverter conduit 94 and a description of the components therein, a wash water interim holding tank 167 is connected to this conduit 94 upstream of the previously mentioned conduit inlet valve 165. In the preferred embodiment, tank 167 is preferably formed from stainless steel and has about a 40 gallon capacity. High and low water switches 169 and 171 are provided therein, as well as a water level indicator tube 173 which may be isolated from the tank 167 by means of isolation valves 175a, 175b. For quality monitoring purposes, a water sampling tap 177 having a needle valve 179 is connected to the indicator tube 173. The tank 167 also includes a gate-type drain valve 181 to facilitate a general drain-down of the apparatus 1. Downstream of the wash water interim holding tank 167 is another self-priming single impeller centrifugal pump 183. Pump 183 is actuated and deactuated by high and low level water pressure switches 169 and 171. Upstream of pump 183 is a ball-type check valve 185 for preventing the backup of any water from the washing machine 3 back into the tank 167.
The rinse water system 68 includes components which operate in very much the same fashion as the previously described components of the wash water system 64. Specifically, the rinse water system 68 includes a five-micron particulate filtration unit 190 and a one-micron particulate filtration unit 192 serially connected as shown. Each of these filtration units uses disposable, cartridge-type filter elements (shown in phantom). Sample water taps 193 and 196 having needle valves 194 and 197 are provided in each of the particulate filtration units 190 and 192 for water quality testing. Additionally, pressure gauges 199, 201, and 203 are provided upstream and downstream in each of the particulate filtration units 190 and 192 in order to determine the relative extent to which the filter elements in the particulate filtration units 190 and 192 have become saturated. For assembly purposes, all the aforementioned components are flanked by union ball valves 204 and 205.
The rinse water polisher 210 is located downstream of the union ball valve 207, and is comprised of two separate polishing banks 212a, 212b hydraulically connected in parallel via conduits 214a, 214b. Each of the banks 212a, 212b of the rinse water polisher 210 includes a carbon column 216a, 216b and a mixed cationanion column 218a, 218b. Water testing taps 220 having needle valves 222 are located between the columns of each of the polisher banks 212a, 212b for testing purposes. Additionally, pressures gauges 224 and differential pressure gauges 226a, 226b are installed at various junctions in and between the rinse water polishing banks 212a, 212b for determining the location of flow-blocking stoppages which may occur in the polisher 210. In order to achieve the same redundant capacity as the wash water polisher 93, isolation valves 228a, 228b and 230a, 230b are provided in the locations indicated.
Downstream of the rinse water polisher 210 is a union ball valve 232 for assembly purposes, and an ohmic water quality tester 234. A rinse water holding tank 236 is provided downstream of the rinse water polisher 210 for parking a reservoir of filtered and polished rinse water for use in the washing machine 3. The tank 236 is again preferably formed from stainless steel and has at least a 40 gallon capacity. The tank 236 preferably also includes both high and low water pressure switches 238 and 240 which serve to actuate and deactuate a centrifugal pump 256 located downstream thereof. Finally, the rinse water holding tank 236 includes a water level indicator tube 242 for visually monitoring the level of water therein, a water sampling tap 244 having a needle valve 246, and a pair of isolation valves 248a, 248b for isolating the water level tube 242 from the tank 236. A fill port 250 and gate-type drain valve 254 are provided as indicated. The outlet of the centrifugal pump 256 located downstream of the tank 236 is connected to a water sampling port 257 by way of a ball valve 258, as well as to the rinse water inlet 8 by way of a ultraviolet sanitizer 260 which is flanked on either side by union ball valves 262a and 262b. Another union ball valve 264 and a pressure gauge 266 are disposed between the ultraviolet sanitizer 260 and the rinse water inlet 8 as shown.
In the method of the invention, approximately 50 pounds of soiled and radioactively contaminated garments are disposed in the agitating and spin-dry drum 5 of the washing machine 3. The washing machine 3 is actuated and wash water inlet valve 7 is opened. To supply wash water to the washing machine 3, solenoid-operated valves 142 and 159 are opened and centrifugal pump 146 is actuated until the high water pressure switch 19 of the machine 3 indicates that a sufficient amount of wash water has been admitted therein. At this juncture, inlet valve 7 is closed, as are valves 142 and 159. Additionally, centrifugal pump 146 is deactuated.
Next, surfactants and suspension agents are added to the wash water that has been admitted into the washing machine 3 from the surfactant and suspension agent reservoir 14 via conduit 16 and solenoid-operated valve 18. In the preferred method of the invention, approximately a 50/50 mix of type A (for particulates) and type B (for oil and grease) surfactants are used along with a sufficient amount of a commercially available suspension agent to prevent the particulates dislodged from the clothing to become reentrained in the clothing at the end of the washing cycle. The clothes are then thoroughly washed in the machine 3 for approximately 5 minutes.
After the end of the first 5 minute wash, solenoid-operated outlet valve 23 is opened and the wash water is rapidly dumped through a four inch drain first through the bag filter 11 to rid it of all large particulates and pieces of debris, and then into the washer drain collecting tank 25. As soon as high water pressure switch 29 is closed by the rising level of the wash water in the washer drain collecting tank 25, pumps 54 and 58 are actuated. At the same time, solenoid-operated check valve 66 leading into the rinse water system 68 is closed, while wash water system inlet valve 62 is opened so that the wash water proceeds through the five- and one-micron particulate filtration units 74 and 76.
At this juncture, the wash water can either flow through the polisher conduit 92, or through the diverter conduit 94 depending upon whether solenoid-operated valves 96 and 165 are opened and closed, respectively, or vice versa. In the preferred method of the invention, the garments in the washing machine 3 are subjected to three separate washes before being rinsed, although more washes could be added if the garments were heavily soiled. In the first two of the three separate washes, polisher inlet valve 96 is closed while the diverter conduit valve 165 is opened in order to divert the filtered but unpolished wash water into the wash water interim holding tank 167. As soon as the water level in the tank 167 is high enough to actuate the high water switch 169, centrifugal pump 183 is actuated, and wash water inlet valve 7 is opened while close-off valve 159 is closed. As has been mentioned hereinbefore, such hydraulic short-circuiting of the wash water obviates the need for the addition of new surfactants and suspension agents to the wash water with every wash while advantageously extending the lifetimes of the carbon and ion-exchange columns in the wash water polisher 93. Still another advantage associated with such short-circuiting is the expedition of the wash cycle as a whole.
In the last wash of the wash cycle, the conduit diverter valve 165 is closed and the polisher inlet valve 96 is opened so that all dissolved radionucleides, body salts, organic solvents, and dissolved gases are completely removed from the wash water. The resulting purified wash water flows through the union ball valve 122 and into the wash water holding tank 126, where it is "parked" for use in the next wash cycle.
At the end of the last wash of the washing cycle, the drum 5 of the washing machine 3 executes a highspeed extraction by rotating the garments so that they experience centrifugal forces on the order of 400 to 500 Gs. Such large centrifugal forces has the effect of squeezing out approximately 82% of all of water entrained in the garments, even if they are made from highly absorbent material such as cotton. The large degree of water extraction achieved at this juncture by the spin-drying step advantageously removes virtually all of whatever residual particulate contaminates which may have been dislodged by the wash water in the last wash of the cycle. In the preferred method, the spin-drying step lasts approximately four minutes.
In the preferred method of the invention, two separate rinses complete the rinse cycle. Each of the rinses commences with the introduction of rinse water into the rinse water inlet of the machine 3 via inlet valve 9. After the high water level switch 19 of the washing machine 3 has been actuated, the inlet valve 9 is shut off, along with the centrifugal pump 256. The drum 5 then agitates the garments for approximately seven minutes whereupon the rinse water is dumped out through the outlet conduit 12 in virtually the same manner as has been previously described with respect to the wash water system 64. Of course, as the rinse water is being dumped, wash water system inlet valve 62 has been closed and rinse water system inlet valve 66 has been opened, so that the rinse water flows through the five-micron and one-micron particulate filtration units 190 and 192 of the rinse water system 68. From there, the filtered rinse water flows through the rinse water polisher 210 and into the rinse water holding tank 236. When the high level pressure switch of the rinse water holding tank 236 is actuated, centrifugal pump 256 is again actuated, thereby commencing the reintroduction of recycled rinse water into the washing machine 3 and the commencement of the second rinse cycle.
At the end of the second rinse, another spin-drying, high speed extraction step is implemented by the drum 5, which again lasts approximately four minutes. This last spin-drying step not only gives the high-purity water of the rinse water system 68 one last chance to dislodge and remove particulate contaminates from the garments, but also serves to minimize the need for make-up water in the apparatus 1. | Both an apparatus and method for water washing garments and removing radioactive contaminates therefrom without the generation of liquid effluents is disclosed herein. The apparatus comprises a washing machine unit having a wash water inlet, a rinse water inlet and an outlet conduit, and a hydraulically closed wash water system. The was water system in turn includes a reservoir of filtered and demineralized water connected to the wash water inlet, a particulate filter unit connected to the outlet conduit for removing particulate impurities from the wash water discharged through the conduit, and a water polisher connected between the particulate filtration unit and the reservoir for supplying the reservoir with filtered and demineralized and chemically purified water. To conserve surfactants and suspension agents added to the wash water in the washing machine unit, the wash water system further includes a diverter conduit connected between the filtration unit and the wash water inlet of the washing machine unit. The apparatus further has a hydraulically closed rinse water system which likewise includes a particulate filtration unit, as well as a water polisher. The apparatus avoids the generation of radioactive liquid effluents by trapping substantially all of the radioactive nucleides in disposable, cartridge-type filter elements that are used in the filtration unit of the wash water system. Moreover, the use of polished water in both the wash and rinse water systems renders the resulting water wash more effective. | 3 |
FIELD OF THE INVENTION
The invention refers to an overhead public transport installation for urban and peri-urban environments comprising vehicles rolling on track ropes between overhead stations above the road transport system.
STATE OF THE ART
The creation of a new means of overhead public transport in the urban fabric above the existing road transport system obviously poses a number of problems of integration, notably of its stations for limiting their bulkiness at places where nothing has been provided for this purpose. Moreover, such a means of transport has never been taken into account in town planning projects.
Moreover, the access of passengers to the vehicles in a station from the sidewalks on both sides of the urban roads will result in an increase in their crossing and a more considerable traffic interruption, this trouble being more noticeable when the stations are located at crossroads.
The operation of the overhead transport lines imposes some constraints regarding the situation of the boarding and/or disembarkation platforms which do not very often coincide with the available places on the sidewalks for a direct access to the platforms.
OBJECT OF THE INVENTION
The object of the invention is to create a station spanning the road transport system and provided with a more or less large platform according to the need, above the overhead clearance of the road transport system and below the level of the boarding and/or disembarkation platforms while taking advantage of the height of the sags in the track ropes which heighten accordingly the level of the station platforms with respect to the overhead clearance to be respected.
The surface of the platform can be variable according to the type of stations, while being formed either by a simple footbridge between two pillars facing each other on both sides of the road transport system or by a real pedestrian square above a crossroad of several roads, which even enables to design, in a rational way, connecting stations for several transport lines crossing above the platform at different levels.
Furthermore, in addition to ensuring in a functional way the change of level of the passengers, the development of a public transport station must take into account, with regard to the users, their circulation, their waiting during a peak period, the points where tickets are sold or checked. These various constraints require to find dedicated areas that can be large in the event of dense traffic, which can be very voluminous, very difficult to find at the level of the road transport system and expensive at the upper level of the boarding/disembarkation of passengers.
The obligations to ensure the correct operation of such a means of overhead public transport, with the constraints inherent to the integration into an urban fabric which is not flexible and congested, thus result in finding new functional arrangements.
The platform of a station according to the invention is located under the level of boarding/disembarkation of passengers, and above the overhead clearance of the road transport system because of the sag in the track ropes. The pillars located outside the road transport system support the platform and comprise means of access to the platform from the sidewalks.
Thus the platform according to the invention:
is freely open to pedestrians and users, allows users only to reach the upper overhead transport level and in an essential way, reconstitutes all the areas necessary for the good operation (in particular when the traffic is dense) of the transport system, which is impossible to find at the ground level, ensures, on the one hand, regarding pedestrians, a sure means of crossing the roads, and on the other hand, regarding traffic, an improvement thanks to a reduction in the number of pedestrian crossings.
According to a feature of the invention, there are two pillars on both sides of the station, and the means of access preferably comprise elevators leading to the intermediate level of the footbridge and the upper level of the boarding/disembarkation platforms.
According to a feature of the invention, each pillar is provided with two elevators in order to ensure the availability of operation.
According to another feature, the elevators have doors perpendicular to the installation tracks allowing a pedestrian circulation at all the levels, in particular at the level of the road transport system.
The platform according to the invention can comprise first free zones of use for pedestrians, and second zones only for the users of the public transport, and comprising a number of services.
The users can reach the upper boarding level from the lower level of the road transport system via a first free access way leading to the platform from places outside the traffic, and the dedicated boarding/disembarkation gates of the public transport from the platform via a second access way for users only.
Regarding this second access way, the elevators can be provided with automatic doors opening at the upper level facing and against those of the vehicle. The elevator car thus has a triple function of double-entrance security door, vertical transport and platform. By this means, there is no plate above the platform, which reduces considerably the visual impact of the station.
In the case of a vehicle having two side doors on the opposite sides, the access to the vehicle is given by two elevators, one for boarding, and the other for disembarking.
BRIEF DESCRIPTION TO THE FIGURES
Other advantages and features of the invention will more clearly arise from the following description of various embodiments of the invention given as examples and represented in the annexed drawings, in which:
FIG. 1 is a line profile of an installation using ropes and provided with a station according to the invention;
FIG. 2 is a cross view of a station according to the invention for an installation comprising two vehicle running tracks at the same level;
FIG. 3 is a top view of the platform level in FIG. 2 ;
FIG. 4 is a top view of the footbridge level in FIG. 2 ;
FIG. 5 is a top view of the road transport system level in FIG. 2 ;
FIG. 6 represents a top view of a town square including a function of two avenues with accesses to the platform according to the invention;
FIG. 7 represents a top view of two overhead transport lines located above the running tracks and crossing at different levels, with the stopping position of the vehicles, and their contiguous vertical access from the platform;
FIG. 8 represents a top view of the platform with the locations of the accesses from the sidewalks corresponding to FIG. 6 , and the accesses for the boarding/disembarkation into/from the idle vehicles of the two overhead lines at different levels, corresponding to FIG. 7 ;
FIG. 9 represents a front view of the superposition of the different levels in FIGS. 6 , 7 and 8 .
DESCRIPTION OF THE INVENTION
FIG. 1 represents a line profile of an installation using track ropes 34 on which a vehicle 25 circulates, in particular a cablecar, along a trajectory 26 above the level of the road transport system 7 . The footbridge 36 or platform is placed under the level of the platforms 24 of a station 38 , which must be higher than the overhead clearance 27 because of the sag in the track ropes.
FIG. 2 represents a station 2 in which vehicles 3 and 4 , each of them running in a different direction, stop in front of the boarding platforms 5 . The station 2 comprises two pillars 8 located on both sides of the road transport system 7 and supporting a platform 6 located under the levels of the platforms 5 it supports via posts 1 . The accesses to the platform 6 and boarding platforms 5 from the road transport system 7 are represented by two different systems which are elevators 9 or staircases 10 integrated in the pillars 8 . According to the span of the platform 6 , there may be one or more intermediate supports 11 which can also be used as support for possible platforms 12 located between the two running tracks for the vehicles 3 and 4 .
FIGS. 3 , 4 and 5 are top views of the various levels of a station 2 according to FIG. 2 . The doors of the elevators 9 , located in one of the pillars 8 , are advantageously arranged so as to allow a rational access of the users in the longitudinal direction of the road transport system 7 , FIG. 5 showing the possibility of accessing to the elevators while encroaching at a minimum upon the sidewalk width.
FIG. 6 represents an intersection of two avenues 100 forming the road transport system 7 between the buildings 114 of an urban zone, which avenues are bordered by sidewalks 101 on which pedestrians can walk. These pedestrians can reach the platform 6 according to the invention, represented here in dotted lines in the center of the intersection of the two avenues 100 , through accesses 102 , advantageously formed by elevators 9 , escalators 115 or staircases 10 , located at strategic places on the sidewalks 101 .
FIG. 7 represents an overhead transport line 105 crossing a second overhead transport line 110 located at a higher level. The stopping places of the vehicles 108 , 109 running on the line 105 are contiguous with their vertical accesses 111 , 112 from the level of the platform 6 . In the same way, the stopping places of the vehicles 103 , 104 running on the line 110 are contiguous with their vertical accesses 106 , 107 from the level of the platform 6 .
FIG. 8 is a top view of the level of the platform 6 on which is arranged a zone 113 for the users of the urban transport who use the vertical accesses ( 106 , 107 , 111 , 112 ) for the boarding/disembarkation into/from the idle vehicles ( 103 , 104 , 108 , 109 ) of the two lines ( 105 , 110 ).
FIG. 9 represents a station 120 in which vehicles 108 , 109 , each of them running in a different direction on the overhead track 105 , stop in front of their respective vertical boarding/disembarkation accesses 111 , 112 and vehicles 103 , 104 , each of them running in a different direction on the overhead track 110 located at a higher level, stop in front of their respective vertical boarding/disembarkation accesses 106 , 107 . The station 120 comprises two pillars 8 located on both sides of the road transport system 7 and supporting a footbridge 6 located under the level of the tracks 105 , 110 .
The accesses to the platform 6 from the road transport system 7 are represented by two different systems which are elevators 9 or escalators 115 integrated in the pillars 8 . One can reach the vehicles 103 , 104 , 108 , 109 from the platform 6 through the corresponding vertical accesses 1056 , 107 , 111 , 112 .
According to an alternative embodiment, each vehicle has two side doors on the opposite sides, the boarding/disembarkation into/from two successive vehicles being performed alternatively via two elevators, one for the doors on one side of the vehicle and the other for the doors on the other side. | Overhead public transport installation for urban and peri-urban environment using track ropes with overhead stations, each comprising a platform situated below the level of the boarding/disembarkation platforms and consistent with the overhead clearance of the road transport system in terms of the difference in level that corresponds to the sag in the track ropes. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a ridge latch plate and cooperating latch pin for joining together two beams of a constructional arch.
2. Description of the Prior Art
Various types of connecting devices have been devised by the prior art for interconnecting the terminal ends of structural beams. These connecting devices secure the position of one beam relative to the other beam when the beams are in the appropriate positions.
U.S. Pat. No. 3,646,725 to A. L. Troutner, discloses a two-piece connector for joining pitched truss members in which the load imposed by the truss member is borne by cooperating bearing faces provided on each connector. The connectors are locked together at any desired angle relative to one another by a central bolt and cooperating nut. Each connector is attached to a truss member and the two connectors are bolted together prior to installation at the roof.
U.S. Pat. No. 4,050,210 to Gilb describes a truss connecting device having a pair of identical U-shaped channels. Each channel accommodates a truss and is secured to the truss by bolts. Each channel has an integral flap providing a compression plate which cooperates with the compression plate on the other channel. No means are disclosed for automatically latching the channels together.
In the building construction industry, due to the ever-increasing demand for unobstructed floor space, the trend has been towards roof arch beams of large dimensions. Such massive beams are usually installed using a crane or heavy moving equipment. When the two beams of an arch have been aligned at the ridge of the roof, it becomes necessary for workmen to gain access to the ridge in order to lock the two beams together. Reaching the ridge of such aligned beams is firstly a hazardous occupation as the workmen are operating on two beams, each of which is separately supported by a crane. This joint operation is also carried out at a considerable height from the ground. Secondly, elaborate equipment is required to transport the workmen to the roof ridge. This equipment usually includes a workmen's cradle with attendant pulleys and control mechanisms. Thirdly, the cost of the operation is considerable in terms of the time required by the workmen in gaining access to roof ridge and additionally, the time taken to join the beams together.
The present invention has as its primary objective and advantage, the provision of a pair of ridge latch plates and cooperating latch pin which will automatically lock two constructional beams together without the need of manually joining the beams of the arch together.
Another object of this invention is the provision of a pair of ridge latch plates and cooperating latch pin which avoids the hazardous and costly operation of elevating a workmen to the roof ridge.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Particularly with regard to the invention disclosed herein, it should not be construed as limited to the joining of constructional beam arches, but should include the joining together of a plurality of beams in the construction industry by cooperating latch plates and latch pins.
SUMMARY OF THE INVENTION
The ridge latch plates and cooperating latch pin of the present invention is defined by the appended claims with a specific embodiment shown in the attached drawings. For the purpose of summarizing the invention, the invention relates to a pair of ridge latch plates and cooperating latch pin for joining together a pair of constructional beams to form an arch. A latch pin having two ends extends through one of the constructional beams. The ends of the latch pin protrude from the opposite sides of the beam. A pair of ridge latch plates are secured adjacent opposite sides of the other beam. Each latch plate includes a latch pivotably mounted to the latch plate. The distal ends of each of the latches engage the protruding ends of the latch pin. Each of the latch plates has a guide for guiding the end of the latch pin toward the distal end of the latch for engagement therewith.
In a more specific embodiment of the invention, the latch pin is located within the beam by locating dowels. Additionally, the guide on the latch plate is defined by the peripheral edge of the latch plate with the guide being widest at the edge of the latch plate remote from the latch pivot and narrowing down towards the distal end of the latch. With a pair of latch plates, the ends of the respective latch plates remote from the latch pivot are flared outwardly relative to each other. These flared ends facilitate the guidance of a constructional beam and attendant latch pin into engagement with a corresponding pair of latch plates secured to a second beam.
The distal end of each latch has a sloping edge for cooperation with a corresponding end of the latch pin. As the two constructional beams approach each other, the sloping edge of the latch bears against the end of the latch pin to pivot the latch about the latch plate until the end of the latch pin is firmly latched within a groove defined by the latch. With the end of the latch pin located within the groove of the latch, this end of the latch pin is also located within the narrow end of the guide defined by the latch plate. A stop is disposed on the side of the latch plate on which the latch is mounted. The stop limits the rotation of the latch relative to the latch plate.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additionally, features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other devices for carrying out the same purposes of the present invention. It should also be appreciated by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a pair of ridge latch plates and a cooperating latch pin;
FIG. 2 is a side elevational view of a latch plate and a latch pin in the engaged position;
FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2;
FIG. 4 is cross-sectional view taken on line 4--4 of FIG. 3; and
FIG. 5 is a cross-sectional view taken on line 5--5- of FIG. 3;
FIG. 6 is a side elevational view of the pintle at the bottom of the constructional beam;
FIG. 7 is a cross-sectional view taken on line 7--7 of FIG. 6;
FIG. 8 is a side elevational view of a pair of constructional beams according to the present invention.
Similar reference characters refer to similar parts throughout the several views of the drawing.
DETAILED DESCRIPTION
FIG. 1 is a perspective view of a pair of ridge latch plates and cooperating latch pin in which a first constructional beam, generally designated 10, has a latch pin 11 extending therethrough. An end 12 of the latch pin 11 protrudes from a first side 14 of the beam 10. A dowel 16 passes through the end 12 of latch pin 11 to locate the latch pin 11 within beam 10. As shown more particularly with reference to FIG. 3, the other end 13 of latch pin 11 protrudes from the opposite side 15 of beam 10. The end 13 also has a dowel 17 to locate latch pin 11 within the beam 10. A pair of ridge latch plates, generally designated 18 and 19, cooperate with the ends 12 and 13 respectively, of latch pin 11. The latch plates 18 and 19 are secured adjacent sides 20 and 21 respectively, of a second constructional beams, generally designated 22. The first latch plate 18 has a first latch 23 pivotably mounted on the latch plate 18 by a pivot pin 24. A sloping edge 25 of the distal end of the latch 23 bears against the end 12 of latch pin 11 to rotate the latch 23 relative to the pivot pin 24 until the end 12 of the latch pin 11 is firmly latched within groove 26 defined by the distal end of the latch 23.
A stop 27 disposed on the latch plate 18 on the same side of the latch plate as the latch 23, limits the rotation of the latch 23 relative to the latch plate 18. A guide, generally designated 28, is defined by edges 29, 30 and 31 respectively, of latch plate 18. Guide 28 is wider at ends 32 and 33 of the latch plate 18 remote from the pivot pin 24 whereas the guide is narrowest at a location adjacent the groove 26 of the latch 23. The function of the guide 28 is to guide the end 12 of latch pin 11 towards the sloping edge 25 of latch 23 and then towards groove 26 of the latch 23 to lock the end 12 of the latch pin 11 within the groove 26. The ends 32 and 33 of latch plate 18 are flared outwardly about lines 34 and 35, respectively so as to facilitate the guidance of the first beam 10 between the ridge latch plates 18 and 19 respectively.
The second latch plate 19 is identical to latch plate 18 except in that it is constructed in reverse relative to the latch plate 18. Thus the latch plate 19 is a mirror image of latch plate 18. Latch plate 19 is secured to the second side 21 of the second beam 22. The second latch 36 is pivotably mounted on latch plate 19 by pivot pin 37 so that the sloping edge 38 will bear against the end 13 of the latch pin 11 to rotate the latch 36 relative the latch plate 19 until the end 13 of the latch pin is latched within a groove 39 defined by the distal end of the latch 36. The edges 40 and 41 of latch plate 19 are flared outwardly about lines 42 and 43, respectively to facilitate the guidance of the side 15 of the first beam 10 between the latch plates 18 and 19. The latch plates 18 and 19 are secured adjacent the sides 20 and 21 of the beam 22 by means of screws, nails, or any other suitable anchoring means. The stop 27 and a corresponding stop 44 for the latch 36 are either stamped from the metal of the latch plates 18 and 19 respectively, or are fabricated separately and welded at the correct location on the latch plates 18 and 19.
FIG. 6 is a side elevational view of the pintle at the bottom of a constructional beam 10. A pintle 45 is rigidly secured to the sidewall 46 of an inverted metallic saddle 47. The saddle 47 is mounted upon the bottom of the beam 10 by means of wood screws 48 having threaded shanks 49 and cooperating nuts 50. The saddle 47 also has a sidewall 51 having a pintle 52 disposed thereon. Alternatively, the saddle may be secured to the bottom of the beam by means of bolts (not shown) passing through aligned apertures defined by the sidewalls 46 and 51 respectively.
The pintle 45 is supported within a socket groove 53 defined by the sidewall 54 of a base mounting saddle 55. The saddle 55 is secured to the concrete foundation structure of a building by bolts and nuts 56. The socket groove 53 has a wider portion 57 at its upper end so that when the constructional beam is lowered into position, the pintle 45 is guided within the socket groove 53 by the portion 57. The saddle 55 has another side 58 provided with a socket groove identical with that defined by side 54 for the reception of the pintle 52 therein.
Two constructional beams 10 and 22 are shown in FIG. 8. These beams are supported by wire hawsers 59 and 60, respectively. Beam 10 is shown with the pintles 45 and 52 already located within the socket grooves of the base mounting saddle 55. The beam 22 is being lowered into engagement with the socket grooves.
When the pintles and sockets have been engaged the upper ends of the beams can be connected by means of the latch pin and cooperating latch plates as hereinbefore described.
An important feature of the present invention is the provision of a pair of latch plates which can be manipulated from a remote location and which will automatically engage the ends of a latch pin to lock two constructional beams of an arch together.
The present disclosure includes that contained in the appended claims as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. | A pair of ridge latch plates and cooperating latch pin is disclosed for joining together two beams of a constructional arch. The invention includes a latch pin which extends through one of the beams with the respective ends of the latch pin being engaged by latches pivotably mounted on latch plates secured on opposite sides of the other beam. Guides are provided on each latch plate for guiding the protruding ends of the latch pin into engagement with the distal ends of each latch. | 4 |
RELATED APPLICATION
This application is based upon and claims the benefit of Provisional Application 60/296,190, filed Jun. 5, 2001.
BACKGROUND OF THE INVENTION
To make retractable a very large roof so as to move it completely off the space it covers presents new challenges. Such a roof may be a barrel vaulted roof hundreds of feet long, or a pitched roof hundreds of feet long, or even a flat roof hundreds of feet long. The object is to move such a roof as one unit. The object also is to move the flat roof in sections.
The state of the art today shows no quick answer to these requirements. There are smaller retractable roofs often made of plastic or glass used over swimming pools and garden courts. There are unit skylights of various shapes either in glass or plastic that are made to slide. There are custom roofs in either glass, plastic, or other material. None of these roofs show how to move a large barrel vaulted roof, a pitched roof, or a flat roof in the large size required, completely on and off the opening they cover.
When the roofs become very large, one of the new issues is the temperature expansion of the retractable roof versus the supporting structure. In new stadiums this is sometimes accounted for by partially articulated wheel trucks. On smaller roofs this is sometimes accounted for by expansion and contraction of the retractable roof frame taken by sideway movement of the wheels on the supporting rails of the roof. In this invention the effort is not to mitigate the expansion and contraction movement of the roof on the wheels, but to create a system where the rail for the roof supporting wheels moves closely the same as the roof from temperature expansion and contraction, so no thermal expansion and retraction accommodating means are needed at all between the roof and the wheels. This is done by supporting the rail on an intermediate frame which spans the area being covered so that the rail and the support therefore will expand and contract as one. To manage this, the intermediate frame is supported on slide bearings resting on columns, or possibly walls or another beam structure, so that it is free to move in unison with the roof, both exposed to similar temperatures. In this manner the roof and wheels see limited to small differential movement so no measures such as articulated frames or rollers or even slide bearings are needed between the roof and the wheels.
This alone does not assure that the roof can be moved evenly. The retractable frame that is moved must be very rigid. Rigidity in panelized roofs on stadiums extends only to the individual panels. This invention moves the entire roof as a monolithic piece and therefore requires bracing of the entire roof. This is done very simply with X bracing or other forms of bracing in the retractable roof.
Thirdly to move a large monolithic roof evenly requires that the drive means, the wheels with attached motors or a cable and winch system, the two most common, must work evenly together. Other stadium roofs use various means of electro mechanical controls to assure one side moves the same as the opposite side so the roof moves evenly. Some stadiums use controls that measure the exact location of the sliding wheels at all times and correct motor speeds to adjust continuously so that the roof runs evenly. In other words so that one side reaches the end point at the same time as the other. Although this could be done with the roof in this invention, this invention uses X bracing in a horizontal frame supporting the roof to transfer differential traction forces directly between the wheels and motors which drive the roof. Direct transfer of traction forces evens out the movement of all the motors and wheels contributing to an even parallel movement of the roof. This invention also uses motors on all wheels. At the same time redundancy is achieved. Should one motor fail, the loss will be taken up by the others.
It is these ideas brought together in an artful and engineered manner that result in a smooth operating very large retractable roof to be used on a mall or other large area, which has never been done in this or a similar manner.
The following drawings together with the detailed description will describe this further.
SUMMARY OF THE INVENTION
The invention shows how to move a long barrel vaulted retractable roof on and off a space such as a mall walkway. A frame is built on a series of support columns with intermediary slide bearings to allow for temperature expansion and contraction. Over the frame rails are built on which the barrel vaulted roof can slide. The frame members are spaced at intervals, the length of the mall walkway. In so doing the barrel vaulted roof is built as one section which expands and contracts similar to the frame, allowing smooth movement. Motors are attached to the wheels of the frame of the barrel roof and X bracing is interwoven between the members of the frame, to provide a transfer of traction forces to permit even movement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from a bottom vantage point, showing the retractable roof system of FIG. 2A , with the roof in closed condition;
FIG. 2 is a perspective view corresponding to FIG. 1 showing the retractable roof system of FIG. 2A , with the roof in open condition;
FIG. 2A shows an exploded perspective view, with parts thereof broken away, showing the inventive retractable roof system from a top vantage point, with a roof of an elongated barrel vaulted configuration;
FIG. 2B is a non-exploded perspective view corresponding to FIG. 2A ;
FIG. 2C is an end view of the retractable roof system of FIG. 2A , with phantom lines depicting the roof structure in the open condition;
FIG. 3 is a perspective view corresponding to that of FIG. 1 modified to show a roof of an elongated peaked configuration in closed condition;
FIG. 4 is a perspective view corresponding to that of FIG. 2 modified to show a roof on an elongated peaked configuration in open condition;
FIG. 5 is a perspective view corresponding to that of FIG. 1 modified to show a roof of a flat configuration in closed condition;
FIG. 6 is a perspective view corresponding to that of FIG. 2 modified to show a roof of a flat configuration in open condition;
FIG. 7 is a perspective view from a bottom vantage point showing a segmental retractable flat roof partially opened over a mall walkway or other space by sliding parts of the roof on guide beams to the side;
FIG. 8 is a diagrammatic perspective view from a top vantage point, showing the full length of the retractable roof system of FIG. 2A ;
FIG. 9 is a plan view, with parts thereof broken away, showing the roof framework of the present invention with internal X bracing;
FIG. 10 is a plan view, with parts thereof broken away, showing the roof framework of the present invention with internal grid elements used for bracing;
FIG. 11 is a pan view, with parts thereof broken away, showing the roof framework of the present invention with internal corner bracing;
FIG. 12 is a plan view, with parts thereof broken away, showing the roof frame of the present invention with internal diaphragm bracing;
FIG. 13 is a cross-sectional elevation view taken on the plane designated by the line 13 — 13 in FIG. 2C , illustrating an embodiment of the inventive retractable roof system wherein motor driven wheels are used to move the retractable roof, with a separate motor provided for each wheel;
FIG. 14 shows the FIG. 13 from the side;
FIG. 15 is a cross-sectional elevation view similar to FIG. 13 illustrating a motor driven wheel arrangement for moving the retractable roof, where a single motor drives a plurality of wheels through drive shafts connecting the wheels;
FIG. 16 is a cross-sectional view of the segmental retractable roof of FIG. 7 at an edge cross-section similar to FIG. 13 illustrating a drainage channel of the segmental retractable flat roof;
FIG. 17 is a side view schematically drawn showing a wind lock which may be used with the roof of the present invention;
FIG. 18 is a side elevational view, with parts thereof broken away, diagrammatically illustrating a cable drive system which may be used to move the roof structure between the open and the closed condition;
FIG. 19 is a side elevational view, with parts broken away, diagrammatically illustrating a reversible chain drive system which may be used to move the roof structure from the open to the closed condition;
FIG. 20 is a side elevational view, with parts broken away, diagrammatically illustrating a rack and pinion drive system which may be used to move the roof structure from the open to the closed condition;
FIG. 21 is a side elevational view, with parts broken away, diagrammatically illustrating a worm screw drive system which may be used to move the roof structure between the open and the closed condition; and
FIG. 22 is a side elevational view, with parts broken away, diagrammatically illustrating a hydraulic cylinder drive system which may be used to move the roof from the open to the closed condition.
Reference Numbers
1 . supporting framework 2 . X bracing of the supporting framework. 3 . rigid corner connections of the supporting framework 4 . rectangular framework of the supporting framework 5 . shear diaphragm of the supporting framework 6 . parallel beam 7 . rail 8 . column 9 . intermediary beam 10 . mall walkway or other space 11 . monolithic retractable barrel vaulted roof 12 . monolithic retractable pitched vaulted roof 13 . monolithic retractable flat roof 14 . segmental retractable flat roof 15 . drainage channel 16 . column end bracing 17 . roof end bracing 18 . glass 19 . wheel motor 20 . wheel 21 . power rail 22 . winch motor 23 . cable 24 . motor 25 . chain 26 . pinion gear 27 . rack 28 . worm screw 29 . piston rod 30 . cylinder 31 . retractable roof 32 . fixed bearing pad 33 . sliding bearing pads fixed in Y, free to move in X 34 . sliding bearing pads fixed in X, free to move in Y 35 . sliding bearing pads free to move in X and Y 36 . wind lock 37 . shaft 38 . arch member 39 . longitudinal framing 40 . sliding section edge C. foundations F. intermediate frame Y. longitudinal direction X. short direction
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention is the retractable barrel vaulted skylight roof. Other embodiments are the retractable vaulted pitched skylight roof, the retractable monolithic flat skylight roof, and the retractable segmental flat skylight roof. This description will describe the barrel vaulted roof, and in the end describe some of the differences with the others.
Foundations C make the primary support of the roof. On the foundations columns 8 extend to the under level of the retractable roof. At this point the roof may also be supported by other roof framing or it may be supported on walls. In the any case at this level and on top of the supporting structure, in the preferred embodiment columns 8 , are sliding bearing pads 32 to 35 . The bearings permit the roof to expand and contract for temperature. The slide bearing pads permit the roof to expand and contract in the longitudinal direction as one monolithic structure. Along one long side of the roof the bearing pads 34 are free to allow movement in the longitudinal direction Y and yet not permit movement in the short direction. On the bearing pads 35 the roof is free to move in both directions. However, at one end of the longitudinal direction the bearing pads 33 allow only movement in the short direction and no movement in the long direction. The bearing pads 32 are fixed in the X and Y directions. The advantage of this will follow.
On the bearing pads rest parallel beams 6 spanning the opening of the roof. These beams extend an equal distance to one side and over adjoining buildings. These beams are parallel to one another. These beams are the primary supporting beams on which the roof rolls to one side to open or close the roof.
Between these parallel beams 6 are intermediate beams 9 that are perpendicular to the parallel beams spanning in the longitudinal direction of the roof at the bearing pads. The beams 6 and 9 form a unitary intermediate frame F.
As now becomes apparent the frame of the parallel beams 6 and the intermediate beams 9 makes one continuous piece that can move for temperature expansion and contraction in the long and the short direction on the bearing pads while being fixed at one long end and fixed in the short direction of the frame at each parallel beam 6 . A 100 degree Fahrenheit change in temperature for the steel frame in 600 feet length would have a change in length of approximately 4.8 inches.
The columns at one end of the long direction of the roof are braced by bracing 16 . The moveable roof is braced by bracing 17 between the top of the roof and its lower cord.
Bracing may be installed at the columns in the short direction of span also, but the columns and the foundation can also offer this support.
This to now gives a structure on which the retractable roof can be built. The intermediate frame forming part of this structure is free to move for temperature expansion and contraction.
On this structure on the parallel beams 6 are rails on which the roof can slide.
On the rails 7 are wheels 20 supporting the roof. Attached to the wheels are motors 19 in the preferred embodiment.
Attached to the parallel beams 6 are where needed power rails 21 ( FIG. 16 ) from which the motors 19 are powered.
Supported on the wheels is a supporting framework 1 for the roof. This is a continuous rectangular framework 1 . The wheels are built in to it.
It extends the length of the barrel vaulted roof. The barrel vaulted roof rests on this framework and moves with it. The pitched and flat roof of the alternative designs also rest on this supporting framework.
This supporting framework 1 is braced in the preferred embodiment with X bracing, FIG. 9 . Other bracing, as shown in FIGS. 10 , 11 , and 12 may also be used. The bracing is very important as it does two things. It assures that the supporting framework does not skew which would damage the barrel vaulted roof particularly the glass cover. It does this by transferring motor traction from one motor to another to balance traction among all the wheels to assure even movement of the roof without skewing. This feature also serves as a redundant back-up if one motor goes out. The lost traction is taken up by the others through the X bracing of the preferred embodiment.
The barrel vaulted roof comprises arch members that sit on the supporting framework 1 with the arch haunch points supported by the motorized wheels 20 . Between the arch members is longitudinal framing 39 and between the longitudinal framing is smaller framing. Between the smaller framing is glass or other covering means.
At one end of the barrel vaulted roof is bracing 17 supporting the arches in the longitudinal direction of the roof.
The structure of the retractable barrel vaulted roof is one piece. The structure below the wheels, frame F, is another single piece. Both are free to move from temperature. The two structures are exposed to approximately the same temperature, therefore the relative movement one to the other is minimum.
This relative movement is important as it allows the wheels which have flanges to ride always evenly on the rails without the flanges rubbing against the rails with such force that they would prevent the roof from moving.
This completes the description of the barrel vaulted retractable roof. As the roof is exposed to wind and as the force to move the roof is relatively low, the wind if too high would move the roof. To avoid this a wind lock 36 is installed to the retractable roof (see FIG. 17 ). It measures the wind speed and at a programmed speed automatically clamps the roof fixed against movement.
Alternative ways to build the roof may be a pitched vaulted roof as shown in FIGS. 3 and 4 . The design differs only from the above by the shape of the structure set over the supporting framework 1 . The same holds true for the flat retractable roof shown in FIGS. 5 and 6 .
The segmental retractable flat roof in FIG. 7 varies from the monolithic flat roof in that a drainage channel is provided along the side of the sliding roof section 40 and separate sliding bearing pads 32 are provided for each roof section.
Although the preferred embodiment would have motor driven wheels, other means to move the roof may be a winch and cable system as in FIG. 18 , or a reversible chain as in FIG. 19 , or a rack and pinion system as in FIG. 20 , or a motor driven worm screw as in FIG. 21 , or a hydraulic cylinder system as in FIG. 22 , or a motor and shaft system driving multiple wheels as in FIG. 15 .
Although the preferred embodiment would have x bracing as shown in FIG. 9 as a means to brace the supporting frame 1 , other means may be a rectangular framework as in FIG. 10 , or rigid corner bracing as in FIG. 11 , or a shear diaphragm as in FIG. 12 .
It is to be understood that while the subject invention has been described with reference to a preferred design, other designs could be made by one skilled in the art without varying from the scope and the spirit of the subject invention as defined by the appended claims. | The invention concerns a structural and mechanical means to build a large retractable roof, that can have the shape of a barrel vaulted roof or a pitched vaulted roof or a flat roof. The roof is moved as one monolithic roof on and off a mall walkway or other structure. The roof cover is a glass skylight or other material. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Application Ser. No. 60/956,836, filed in the U.S. Patent and Trademark Office on Aug. 20, 2007 by Edward Acworth, and U.S. Provisional Application Ser. No. 61/026,826, filed in the U.S. Patent and Trademark Office on Feb. 7, 2008 by Edward Acworth, the entire contents of these applications being incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to creating a mosaic. In particular, the present disclosure is directed to creating a mosaic by arranging a plurality of tiles based on a design and calculated and implemented by software and a machine.
[0004] 2. Description of the Related Art
[0005] The art of creating mosaics has existed for millennia, all over the world. A mosaic is essentially a decorative surface made by inlaying pieces of variously colored material or tiles, to form pictures and/or patterns. In the art, it is generally known that the pieces of material used to form mosaics are ceramic, marble, stone and other types of tiles. The pieces of material are normally held in place by mortar, glue, grout, or other adhesives.
[0006] Known methods for creating mosaics include best match methods, where attributes are matched to a target region or subregion. That particular method requires significant human labor and it is extremely time consuming. Other methods known in the art lack quality control measures. Therefore, there is a need for a method and system of creating a mosaic efficiently, cost effectively and with little error.
SUMMARY
[0007] In an embodiment of the present disclosure, a system for building a mosaic is presented. The system includes a software processor to design a pattern from an image, a graphical user interface, an operational manager, a sorter, an inspection station, a bufferer and a mechanical mechanism. The pattern is disassembled into a plurality of sub-images, each of the plurality of sub-images is associated with at least one tile. The operational manager determines materials, a quantity of materials and a location in the pattern for each of the at least one tile. The sorter sorts the at least one tile and the inspection station conducts a quality control review for each of the at least one tile. The bufferer buffers each of the at least one tile according to a command from the operational manager and the mechanical mechanism picks and places each of the at least one tile in a predetermined position, as determined by the software processor.
[0008] In another embodiment of the present disclosure, a method for forming a mosaic is presented. The method includes the steps of disassembling an image into a plurality of pixels and inputting feedback relating to the image and the disassembly of the image. Each of the plurality of pixels is associated with at least one tile. The method also includes determining materials, a quantity of a plurality of tiles and a location for each of the plurality of tiles. The method further includes sorting the plurality of tiles, inspecting the plurality of tiles to determine a color for each of the plurality of tiles and to conduct a quality control review for each of the plurality of tiles, and buffering each of the plurality of tiles according to its color, as determined by the step of inspecting. Further, the method includes picking and placing each of the plurality of tiles in a position and assembling the selected tiles into a mosaic, the mosaic being substantially similar to the image.
[0009] In yet another embodiment of the present disclosure, a method for forming a mosaic is presented. The method includes inputting an image, adjusting the image using a graphical user interface and processing the image into a pattern by disassembling the image into a plurality of pixels, each of the plurality of pixels is assigned a color. The method also includes determining a quantity of a plurality of tiles and a location in the pattern for each of the plurality of tiles, sorting the plurality of tiles into a single feed mechanism, and inspecting the plurality of tiles to conduct a quality control review for each of the plurality of tiles. Further, the method includes assigning a color to each of the plurality of tiles, buffering each of the plurality of tiles according to its color, picking and placing each of the plurality of tiles in a predetermined position, and assembling the selected tiles into a mosaic, the mosaic being substantially similar to the image.
[0010] In another embodiment of the present disclosure, a system for building a mosaic is presented. The system includes a graphical user interface to input feedback regarding an image and to manipulate the image, a processor to disassemble the image into a plurality of pixels, each of the plurality of pixels is associated with a color and an operational manager to determine a type of material, a quantity of tiles and a location for each of the tiles. The system further includes a sorter to sort each of the tiles, an inspection station to determine a color for each of the tiles and to conduct a quality control review for each of the tiles, a buffer to group each of the tiles according to the color assigned to each of the tiles at the inspection station, and a robotic arm to pick and place each of the tiles in a predetermined position, as determined by the processor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The objects and features of the present disclosure, which are believed to be novel, are set forth with particularity in the appended claims. The present disclosure, both as to its organization and manner of operation, together with further objectives and advantages, may be best understood by reference to the following description, taken in connection with the accompanying drawings as set forth below:
[0012] FIG. 1 is a flow diagram illustrating a hardware element of the method used to form a mosaic according to an embodiment of the present disclosure;
[0013] FIG. 2 is a flow diagram illustrating a software element of the method used to form a mosaic according to an embodiment of the present disclosure;
[0014] FIG. 3 is a block diagram illustrating a system used to create a mosaic;
[0015] FIG. 4 is an illustrative example of an intersection of two “sections” using a floating surface technique according to an embodiment of the present disclosure;
[0016] FIG. 5 is an example illustrating an interlocking capability of a “section” using a floating surface technique of the present disclosure;
[0017] FIG. 6 is an illustrative example of a section used in a mosaic, according to an embodiment of the present disclosure; and
[0018] FIG. 7 is an illustrative example of a mosaic created, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0019] The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. In addition, the following detailed description does not limit the present disclosure.
[0020] The present disclosure includes a method and a system for creating a mosaic. Even though the present disclosure is described as using tiles, the disclosure is not limited to the use of tiles to create the mosaic, as the use of tiles is for exemplary and explanatory purposes. A mosaic, an example of which is shown in FIG. 7 , may be created using any type of, but not limited to, two-dimensional or three-dimensional object. The two or three-dimensional object may comprise of any material, any substance, any shape, any size, and/or any composition, such as, for example, but not limited to, leather, wood, food, candy, etc.
[0021] A method of the present disclosure includes a hardware implementation and a software implementation, as illustrated in FIGS. 1 and 2 , respectively. The hardware and software may work together or may work alone and are described as follows.
[0022] The design for the mosaic may be based on a pre-existing image. For example, a mosaic may be a replica of a specific bitmap photograph. On the other hand, the mosaic may be a replica of an image created by an artist specifically for the mosaic. Referring to FIG. 2 , at step 220 , an image that is to be replicated in the mosaic is uploaded and is broken down into pixels, where one or more pixels are to be associated with a tile. At step 230 , a user may add structural input to the image. Structural inputs may include tile size and palette, size of grout line width, project size, and matching algorithm. Further, the user enters his/her input on a graphical user interface. The graphical user interface may have a tile palette building function which offers users material and/or color matching capabilities, for example. Palette colors may be adjusted manually or by a software. In addition, the software may import and/or export palette sets and identify colors from photographs. The software may allow the creation of printed photorealistic samples.
[0023] At step 235 , the user input and the image are processed according to an algorithm used to create a mosaic. Once the user has completed his/her inputs at step 230 and the image is processed at step 235 , a digital preview of the mosaic is created as a bitmap image, at step 240 . A software algorithm uses the source bitmap image and the user inputs to calculate how the pixels are associated with tiles. For example, each pixel is a specific color, and therefore a tile of that specific color is associated with that pixel, which is essentially a specific position in the image design or in the mosaic. The preview appears on the graphical user interface for the user to review.
[0024] At step 250 , the user decides whether or not the image should be altered. If the user determines that structural changes should be made, at step 260 , then the software flow goes back to step 230 , where the user may input a variety of changes that are to be made. If structural changes need not be made, at step 270 , the user may make manual adjustments to the mosaic by simply editing a worksheet file, and/or the user may make manual adjustments to the image, and then a new image of the mosaic preview will be output for the user to review (step 240 ). Examples of a structural change include changes to the project dimensions, tile size, grout width, tile palette, dither, etc. (e.g. resize project, change tile size, etc. other program parameters). Examples of manual adjustments include manually changing tile colors tile by tile, using brush tools to paint new tile colors across a broader swath, using a gradient tool to blend tile colors, etc.
[0025] If the image of the mosaic preview, at step 250 , does not require any alterations, then the operational manager, at step 280 , determines the quantity and types of materials that are required to create the mosaic. Generally, an independent source, either a human or a machine, reviews the materials inventory to insure that the tile is available for the project. A further task of the operational manager is to keep track of the inventory and to make sure that there is enough of each type of tile required in the mosaic, as determined in step 280 . If there is not enough of something, in one embodiment, the materials will be ordered and available for the creation of the mosaic. In another embodiment, the process will return to step 230 , where the user may input changes to the design, in order to incorporate the materials that are stocked in the inventory, or to exclude certain materials. Once the materials and quantities are confirmed, at step 285 , a determination is to be made whether or not the mosaic will be fabricated by a robot. If the mosaic will be fabricated by a robot, then the worksheet file will be sent to the robot for production, at step 290 . If the mosaic will not be fabricated by a robot, then the file will be sent to a hand fabricator, at step 295 .
[0026] Turning now to FIG. 1 , the hardware implementation of the method of the present disclosure is presented. The system may include a vacuum system, a pressurized air system, various power supplies, a structural frame, a PC and/or machine control system, optics, a camera, a vision recognition system, a robotic placement system, a tile buffer system, and other systems. The system may also include Bulk tile sorting, tile lanes, tile inspection, tile presentation to the robot, placement of tile in desired pattern, fixation or support sheet application and finished section labeling.
[0027] At step 110 , tiles used for the creation of a mosaic are loaded into a machine in bulk. The tiles are then individualized, at step 120 , as they are lined up, individually, from a mass of tiles loaded in at step 110 .
[0028] At step 130 , the tiles are inspected for quality control, where it is determined, at step 135 , whether the tiles are accepted or rejected. For example, a tile that has a geometric defect such as a tile that is chipped or broken will be rejected, at step 140 . Another example of a tile that could be rejected is a tile that is off-color. If a tile is considered good, then it continues on to the next step. The inspection, at step 130 , may include a vision system. The vision system determines the delivery of a good tile versus the delivery of a faulty tile. Further, along with being able to determine the color of a tile, the vision system may also be able to match colors of tiles, to inspect geometric shapes of tiles and to match them or use them accordingly. In addition, the color is analyzed and determined at this stage. Further, the tile surface color pattern may be characterized more fully, for use by the software matching algorithm to achieve a better fit in the mosaic. For example, striations in natural stone such as marble may be characterized.
[0029] At step 150 , the tiles are buffered and organized into groups of tiles with the same color. The tile buffer may take the form of, but is not limited to, a lane conveyor, gravity feed lanes, in-line feeders, cartridges, turret loaded cartridges, hopper, tape reel, or any other form. An escapement mechanism at the end of each buffer holds the tile for picking by the robot. Once the tiles are buffered in groups by color, at step 160 , the tiles are picked from the appropriate buffer location and placed into the appropriate position in its respective section. The tiles may be picked up and placed manually and/or by using a robot. The position and section in which to place the tile is determined by the operational manager where the operational manager can either be software or a human. The pick and place system may comprise of a robotic arm assembly system, wherein the robotic arm picks up a correct tile and places it according to a delegation. Another pick and place system includes a rolling element, placing tiles robotically. Another system includes an articulated arm that delivers tiles back and forth. Yes another system includes a Cartesian robot that delivers tiles, and another system includes a rastering trajectory that delivers tiles back and forth.
[0030] In an embodiment of the present disclosure, the software program will delegate both an arrangement of the tiles into appropriate sections, and the sections into a final piece of art or into a mosaic. Thus, the placements of the tiles in the entire project may be determined using the software program. At step 165 , a determination is made as to whether the particular section being populated is filled. If it is not filled, then the process goes back to step 160 . If it is filled, then the process continues. An example of a section can be found in FIG. 6 .
[0031] In an embodiment, the robotic assembly has the capability to pick and place a plurality of tiles of a commanded color and to a commanded position, using the x, the y, the z and the yaw positioning. The present invention has tile placement precision, where it uses the x-axis, y-axis, z-axis, and theta-z axis to correctly and accurately place each tile. A raster head may also be implemented, where a feed mechanism is used to rapidly feed out each tile, one by one to the feed head depositing tiles.
[0032] A vacuum system may be applied to prepare a workplace for fixing the tiles into a section. Once the sections are fixated and labeled at step 180 , the vacuum may be removed. Or, in another embodiment, a structural grid may be used to hold the placed tiles. Or, in another embodiment, tiles may be placed directly onto the final fixation (such as clear polymer tape) without being held temporarily in an intermediate support structure.
[0033] Moving along to step 190 , the sections are packed and shipped to an end user. Further, at step 195 , each section is installed together, usually in a specified order, to form the mosaic.
[0034] FIG. 3 illustrates a block diagram of an embodiment of a system of the present disclosure. The system 300 includes a bulk quantity of tiles 302 that eventually go through a sorting and buffering process, as previously discussed.
[0035] A CAD computer 304 , including a graphical user interface (GUI) 306 , allows a user to either design a pattern to be created by a mosaic, and/or allows a user to input an existing image into the CAD computer 304 and further allows the user to edit the image to his/her specifications and requirements, using the GUI 306 . A software algorithm creates a mosaic from an input image and user inputs.
[0036] Once the design has been finalized, the design is sent to the computer controller 308 . The computer controller 308 manages the production system, which will be used to create the end result, a mosaic. The system further includes a human machine operator 310 and a machine controller 312 , which together operate the machine.
[0037] The machine operator 310 is a human being, who physically loads the bulk tiles from the tile inventory 302 and also is responsible for making sure the sections are removed appropriately from the machine, packaged and shipped out to the appropriate end user. The machine controller 312 operates the machine hardware subsystems, and is essentially the controller of an individualizer 314 , an inspection station 316 , buffers 318 , a pick and place mechanism 320 and a section assembly process 322 . Another embodiment may have a tile cutter component 319 , where individual tiles are selected from the buffers, and machine cut before being picked and placed, according to the design.
[0038] Once the tile inventory 302 is loaded by the machine operator 310 , each tile is separated and lined up by the individualizer 314 . Further, each tile is subject to quality control at the inspection station 316 . The quality control may be implemented by digital imaging review, a manual visual review, and/or a mechanical review whereby each tile is sent through a machine with feelers on either end, or a scale, to determine if the tile is whole, or any other inspection means.
[0039] After the tiles have been inspected, they are sent to the buffer 318 . The buffer will store the tiles according to their color or other characteristic. After the tiles are sent through the buffer 318 , individual tiles may be selected from the buffers 318 and may be sent to a machine cutter 319 , where tiles are shaped and cut, before being picked and placed, according to a design. The pick and place mechanism 320 literally picks each of the tiles from the buffer or the machine cutter 319 , that is required for the mosaic, and places each of the tiles into a designated position in a section. The pick and place mechanism 320 may pick and place the tiles one by one, or may pick and place a plurality at a time using a variety of the previously mentioned methods. The section assembler 322 receives each of the tiles that have been placed into each of the sections and fixes the tiles to the section, labels the section, packages the section and labels the package. Then, the sections are shipped to the end user.
[0040] Tiles may be placed together and may form a section in a variety of ways, according to the present disclosure. In an embodiment, a thin polymer film is placed behind the square section of tiles. The polymer film is adhesive on at least one side, whereby allowing the tiles to form a section. Other embodiments may use a mesh backing, and/or adhesive bond between tiles, or other fixation methods.
[0041] In another embodiment of the present disclosure, the tiles adhere to one another with a glue like substance on at least one of the four sides of a tile, whereby the tiles may stick to one another. In yet another embodiment of the present disclosure, at least one tile adheres to at least one other tile using an adhesive netting on the back of the tiles, or a glue dispensing onto fiberglass mesh, on the backs of the tiles.
[0042] Tiles will generally be affixed to a surface, such as, but not limited to, a floor or a wall. In another embodiment of the present disclosure, tiles may be affixed to one another. In yet another embodiment of the present disclosure, a flexible or rigid adhesive may be used to adhere the tiles together in an edge to edge configuration. In another embodiment, tiles may be affixed to a material backing to the tiles, such as a mesh, paper or a polymer film. In yet another embodiment, tiles may be affixed to a material fronting on the top of the tiles, like a mesh, paper or a polymer film. Further, tiles may be affixed to a material backing to the tiles, like a rigid structural substrate.
[0043] Tiles used in a mosaic created by the method and system of the present invention do not necessarily have to be of the same type and dimension. Tiles may usually be square rectangular or octagonal, but may be any geometry, or a variety of geometries. Tiles may be a prefabricated geometry, or the system may shape each individual tile in accordance with the mosaic design. A machine in accordance with the present disclosure may use similar tiles for a project, or may vary the tiles used. In addition, tiles may be received in bags of loose tile, including defective tiles, good tiles and contaminants. The good tiles may be automatically sorted out using the method and system of the present disclosure.
[0044] The software of the present disclosure may also include a pricing function that bases prices from materials, time, functions, labor, etc. The software includes the capability to estimate various features of the process of the project, for example, but not limited to, the time, material types and quantities, number of sections and more.
[0045] In addition, the software has the capability to interface with three-dimensional complex surface modeling, project three-dimensional imaging from an input, and decompose a three-dimensional function for wrapping sheets of tiles around a three-dimensional object. The software may use as an input as-built metrologies of actual complex surfaces that are to be covered with mosaic.
[0046] A tile, as used in connection with the present disclosure, may be a solo tile made from any material, including but not limited to, glass, stone, porcelain, ceramic, metal, wood, leather, mixed materials, food products, ice and others. A tile may also be opaque, translucent or transparent, depending on the use of the tile. Generally, tiles are arranged in a specified order to form a section. In one embodiment, a section is a square, rectangle, polygon, circle, oval, diamond or other planar geometric shape comprising a plurality of tiles. In another embodiment, a section is one square foot comprising a plurality of tiles. A section may be one square foot or any other size. The section is used with a plurality of other sections to be placed together to form an art work, mosaic or a project. In an embodiment, a project is an entire picture or design made from a plurality of sections.
[0047] In a further embodiment, the system of the present disclosure includes a floating surface mosaic system. This system may combine a layer of any assembly of tiles, including mosaic, onto a substrate of interlocking sections (see FIGS. 4 and 5 , wherein FIG. 5 is a close up of the interlocking section), to form a floating surface substrate system. The substrates allow for the physical support, interlocking and fast efficient installation of the surface finishing system. A finishing surface material is affixed atop the substrates, which is a material that may be visible after the installation. The system may be used for flooring, or on any other surface, including but not limited to walls, ceilings and others.
[0048] In using the floating floor system of the present disclosure, installation labor and time is greatly reduced because entire sections of tiling may be installed rapidly in each substrate section, as shown in FIGS. 4 and 5 . Each substrate section may be any shape or geometry, including rectangular and also may be any size. In some embodiments, each section may be 12 by 12 inches, or 15.5 by 15.5 inches, for example. In an embodiment, each section may be completely finished, in that all of the tiles are grouted and assembly is complete. Installation is greatly expedited because all that is required is the installation of each section, and grout is only applied between each section rather than between each tile.
[0049] Another embodiment of the present disclosure includes a backlist mosaic, including a combination of a layer of any assembly of tile, including mosaic, onto a substrate of luminescent light emitting material, or any light box design including, but is not limited to, Light Emitting Diodes, incandescent, halogen, the sun, or any other light source, where the light passes through and/or between the tiles such that a viewer may see the tiles and/or grout as illuminated from within. Transparent, translucent, non-translucent or opaque tiles may be used solely or in combination to achieve an artistic or any other effect. Transparent, translucent, non-translucent or opaque grout between tiles may also be used solely or in combination to achieve an artistic or other effect. Thus, the surface that is covered with mosaic may be seen by the viewer to glow or emit light.
[0050] A light source behind a mosaic or within a mosaic may be solid as one color, or it may be a combination of multiple light sources, to allow addressability of the light sources. Electricity, power and/or control signals and/or sensor signals may be routed through or within each section and may interconnect between sections. In one embodiment, a standard section interconnect may be an integral part of each section.
[0051] In addition, a backlit mosaic may or may not be further enhanced by combining it with a floating surface mosaic system to make a modular floating section with a substrate, an illumination and a tile mosaic in an assembly.
[0052] In another embodiment of the present disclosure, a robot is used with a technology that is implemented to manufacture a mosaic using tiles of any shape required for the mosaic final product. This particular embodiment allows for the manufacture of a mosaic using individual tiles of inconsistent geometries to fit each tile position. In another embodiment, the tiles are each pre-cut to a specified shape before placing into the mosaic. Mixed tile sizes may also be used in a project, for example, but not limited to, 1″ tiles and ½″ tiles used in one project. Also, there may be backlighting of translucent colored glass mosaic sheets, for example, a 1/16″ thick ElectroLuminescent sheet or any other light source. In addition, light emitting tiles are implemented. Light emitting tiles may have light source elements within.
[0053] Mosaics made with the method and/or system of the present disclosure may cover any non-planar surface (curved convex/concave), including deconvoluted complex surfaces and projections. Flexible material grout and tiles may also be used in order to create a flexible mosaic sheet. In addition, mosaics may be covered with flexible fabrics, in order to make pillows and clothing, for example. This may be made by attaching solid or flexible tiles to a flexible fabric substrate.
[0054] Another embodiment of the present disclosure incorporates the ability to design and make mosaic rugs, which in one embodiment are movable and flexible rugs made of tile.
[0055] In yet another embodiment, impressionist mosaics may be implemented. These are unlike traditional mosaics which often rely on homogeneously colored tile material. Contrarily, impressionist mosaics use natural flaws and marbling in some types of tile materials (marbles, glasses, etc.) to create the impression of an image. Vision and software may assist in the characterization and determination of placement. In one embodiment, a plurality of tiles, such as 10, 100 or 1000 tiles may be placed together on a storage/buffer surface imaged together to create a catalog of characterized tiles for later fitting into the mosaic. In another embodiment, tiles may be characterized sequentially and then stored/buffered for later use. Storage/buffering may be gravity or spring loaded feed chute or magazine or cartridge, or may be a conveyor belt, or other method.
[0056] No element, act, or instruction used in the present disclosure should be construed as critical or essential unless explicitly described as such. In addition, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used.
[0057] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of the various embodiments of the present disclosure. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | A method and a system for building a mosaic. The system includes a software processor to design a pattern from an image, a graphical user interface, an operational manager, a sorter, an inspection station, a bufferer and a mechanical mechanism. The pattern is disassembled into a plurality of sub-images, each of the plurality of sub-images is associated with at least one tile. The operational manager determines materials, a quantity of materials and a location in the pattern for each of the at least one tile. The sorter sorts the at least one tile and the inspection station conducts a quality control review for each of the at least one tile. The bufferer buffers each of the at least one tile according to a command from the operational manager and the mechanical mechanism picks and places each of the at least one tile in a predetermined position, as determined by the software processor. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application Ser. No. 07/850639, filed on Mar. 13, 1992, abandoned.
This application has been filed concurrently with U.S. patent application Ser. No. 07/850,637, pending (Celler-Kola 17-1) which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fabrication of x-ray masks and, in particular, masks including a patterned metal on a membrane.
2. Art Background
As design rules in the manufacture of devices, e.g. integrated circuits opto-electronic devices, and micro-mechanical structures, become smaller, the radiation employed for lithography, in turn, must be of a correspondingly shorter wavelength. Thus, for example, when the design rule is below 0.5 μ, use of short wavelength radiation such as x-ray radiation (radiation having a wavelength typically in the range 4 to 150Å) has been suggested.
During exposure, energy incident on a mask which defines a pattern is transmitted in this pattern to expose an underlying energy sensitive material. The energy sensitive material after this exposure is delineated into the pattern by development and employed in the manufacture of the desired device. For x-ray exposure, the mask is generally a membrane stretched across a supporting structure, for example, a ring with a region patterned in a metal coating the membrane surface. Typically, the membrane is a material such as Si, SiN x (x is typically between 1 and 1.3) or SiC, and has a thickness generally in the range 0.1 to 4 μm.
Since the membranes must be quite thin to avoid excessive attenuation of incident energy, substantial stress, i.e. stress greater than 50 MPa, imposed on the membrane from the overlying metal pattern is unacceptable because it causes unacceptable distortion of the pattern. The requirement of limited stress, in turn, imposes substantial limitations on the process of forming the overlying metal pattern.
In a typical mask fabrication procedure, a layer of metal is deposited on a membrane such as by sputtering. A pattern in polymeric material is formed over the metal layer, and the metal regions not covered by the polymeric material are removed by etching. Subsequent removal of the overlying polymeric material leaves a patterned metal overlying the membrane.
Various materials have been suggested for use in the metal layer. Although gold is relatively easy to deposit, its presence in device manufacturing environments and in particular, integrated circuit manufacturing environments, is not preferred. Gold impurities, even in extremely small amounts, introduced into an integrated circuit often substantially degrade the properties and reliability of the device. Stress in gold films is also known to change with time, even at room temperature. Recent studies indicate that at temperatures above 70° C., stresses increase rapidly. Therefore, materials other than gold have been investigated.
One alternative to gold is tungsten. Although tungsten is considered compatible with an integrated circuit manufacturing environment, tungsten rims deposited on a membrane generally induce substantial compressive or tensile stress that ultimately distorts the required pattern or even produces membrane failure. Various attempts have been made to reduce the stress associated with the deposition of tungsten. For example, as described by Y. C. Ku et al, Journal of Vacuum Science & Technology, B9, 3297 (1991), a monitoring method is employed determining stress in the tungsten being deposited. This monitoring method is based on the resonant frequency f of a circular diaphragm of the composite structure which, in turn, is related to the stress by the equation: ##EQU1## where r is the radius of the membrane, σ m , ρ m , and t m are stress, density, and thickness of the membrane respectively, and the corresponding terms such as σ f are stress, density, and thickness respectively, of the film. Since the density of the film and membrane are generally known, this equation allows calculation of stress once the resonant frequency and film thickness are measured.
Ku and coworkers, used a commercially available optical distance measuring device to monitor diaphragm position. Movement of the diaphragm was induced by electrostatic forces applied to the diaphragm from an electronic oscillator-driven capacitively coupled electrode. The oscillator frequency was slowly swept to allow location of the diaphragm mechanical resonance and from this value, the stress was determined.
SUMMARY OF THE INVENTION
It has been found that frequent and rapid measurement of stress is required to allow adjustments in a tungsten deposition system so that stress in the deposited tungsten is meaningfully reduced. Resonant frequency determinations allowing such adjustment at least 6 times per minute, are required to significantly improve stress characteristics. This measurement performance is advantageously achieved in a resonant frequency technique by employing a single electrode monitoring system. This system capacitively drives the diaphragm and simultaneously determines its frequency by maintaining it in mechanical oscillation at its resonant frequency. Use of a single multi-function electrode in this way is quite difficult since the system must exhibit negligible crosstalk between the measuring and driving functions. The system must also be immune to the very high power rf frequency typically employed in the sputtering deposition procedure itself. Further, the capacitance from the backplate to the diaphragm is quite small i.e. less than 20 pF, while associated parallel stray capacitances to ground are generally significantly larger, compounding the difficulties.
These problems are overcome, and rapid measurement is achieved, utilizing the apparatus shown schematically in FIG. 1. A bifilar transformer (1), high voltage emitter follower 2, and shielded cable 3 are employed both to avoid these various problems and to maintain the diaphragm in continuous oscillation. Additionally, since the diaphragm is maintained at its resonant frequency, even though the film thickness is continuously changing, continuous determinations of stress are available. In this manner stress is reducible by adjusting process parameters, such as sputtering gas pressure and/or rf power, in response to me stress measurements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an apparatus for measuring stress in a growing tungsten film.
FIG. 2 is a plot of resonant frequency vs. sputter time for various pressure levels during sputtering of a tungsten film.
FIG. 3 is a plot of membrane deflection at the edge of a tungsten film.
DETAILED DESCRIPTION
As discussed, the invention involves the realization that to control stress during deposition of metals on a membrane, it is necessary to frequently measure this stress during deposition and adjust accordingly. Typically, for membranes having thicknesses in the range 0.1 to 4 μm formed of materials such as Si and SiN x and with deposits of metals such as tungsten, at least 6 measurements per minute should be made. Stress in the evolving metal film is then adjusted by correcting parameters such as sputtering gas pressure and/or rf power. The total stress depends on these parameters in a complicated manner, but typically compressive stress decreases with an increase in sputtering gas pressure or with a corresponding decrease in rf power.
Although the particular method employed to obtain the necessary measurement of stress is not critical, previous techniques (involving relatively slow frequency scanning to establish a membrane resonant frequency) are clearly inadequate. By contrast it has been found that a technique which maintains the membrane at its resonant frequency while utilizing a single driving and measuring electrode, is particularly advantageous in this regard.
In the one-electrode technique, the capacitance between the membrane 4 and the electrode 5 is measured and electronically processed in such a way that the output is a linear function of the distance between the electrode and the membrane. (See G. L. Miller U.S. Pat. No. 4,893,071, dated Jan. 9, 1990, (which is hereby incorporated by reference) and especially FIGS. 8 and 9 with accompanying text in column 6, line 46, to column 7, line 60). From this measurement, a voltage is made available which indicates the position of the membrane, i.e. its distance from the backplate. This voltage is then suitably added to a large, fixed, high voltage (typically approximately 150 volts) and applied back to the electrode 5 via the emitter follower 2 and transformer 1. The operation of this whole loop is such as to continuously maintain the diaphragm in mechanical oscillation at its resonant frequency. Measurement of that frequency, coupled with the use of Equation 1, allows the stress to be determined.
A system for achieving this result is shown in FIG. 1. The diaphragm 4 with its metal layer 6 being deposited, is shown relative to an electrode 5. This electrode is driven by an rf oscillator 7 through a bifilar, one-to-one transformer 1. The rf output of the oscillator is coupled through this transformer to the electrode and is also imposed on a driven shield 3. Since the shield and the lead to the electrode are maintained at the same RF potential, no error due to capacitance between the shield and the center lead of the cable is introduced.
The capacitive measurement of distance using a feedback loop through an rf rectifier 8, and comparison to a reference input 9, has been discussed in U.S. Pat. No. 4,893,071, dated Jan. 9, 1990, which is hereby incorporated by reference (with particular reference to FIGS. 8 and 9). Additionally, related distance measurements based on capacitance have also been discussed in a publication by G. L. Miller in IEEE Transactions on Electron Devices, ED-19, pages 1103-1108, October, 1972.
The disc electrode 5 is driven with RF (typically approximately 1V p-p at 3 MHz) via a toroidal bifilar transformer 1. The far end of the secondary of this transformer is connected to the emitter of a high voltage transistor emitter follower 2 (all power supply and biasing arrangements have been omitted for clarity). Essentially all of the RF 3 MHz displacement current flowing from the disc 5 to the diaphragm 4 therefore flows out of the collector of 2. (Note that the lead to the disc itself is provided with an accurately driven shield 3 to remove the dead capacitance effect.)
The RF current from the emitter follower 2 collector passes through a tuned amplifier (not shown) to a rectifier, the output of which is therefore a measure of the disc to diaphragm spacing. The rectifier output is then compared with a constant (demanded) value 9 and the error signal between the two is used in turn to servo the oscillator 7 (typically 3 MHz) amplitude. In this way the oscillator 7 amplitude itself is accurately and linearly proportional to the position of the diaphragm, i.e. is a linear measure of the spacing from the diaphragm 4 to the backplate 5. This is necessarily so since the operation of this whole electronic loop is such, in effect, as to force a constant magnitude of RF displacement current through the capacitor formed by the backplate 5 and the membrane 4. The system output voltage is simply a linear measure of the magnitude of the RF voltage needed to achieve this end. As such it is proportional to the spacing between the diaphragm and the backplate.
Given such a position signal it is then only necessary to appropriately feed it back as a DC level through emitter follower 2 to cause the diaphragm to constantly oscillate at its resonant frequency. As a pedagogic aid it is possible to visualize this process physically. As long as the diaphragm is moving towards the backplate the DC voltage across the gap is increased above its static value of approximately 150 volts. While the diaphragm is moving away from the backplate the voltage is correspondingly decreased. The associated electrostatic forces cause the diaphragm to oscillate at its resonant frequency. A separate loop stabilizes the magnitude of the diaphragm oscillatory motion by servoing the feedback voltage amplitude. This subsidiary loop also provides damping, or Q, information.
It is desirable to maintain the stress level at a relatively low value. e.g. below 50 MPa, preferably below 10 MPa. Thus, the deposition process parameters as previously discussed are adjusted until the output indicates an appropriate reduction in stress level.
The following example is illustrative of the techniques involved in the invention.
EXAMPLE 1
A 1 μm silicon membrane having a stress of approximately 100 MPa was prepared as described in L. E. Trimble et al., SPIE, Vol. 1263, "Electron Beam. X-Ray, and Ion-Beam Technology: Submicrometer Lithographies IX" (1990), pp. 251-258. This membrane was placed on the sample holder of a conventional sputtering apparatus described in concurrently filed U.S. patent application Ser. No. 07/850,637 (Celler-Kola 17-1) pending. The apparatus was configured such that the gap between the measurement electrode (approximately 2 cm diameter) and the membrane was 250 μm. (The measuring circuitry was, as shown in FIG. 1.) The chamber was evacuated to a base pressure of approximately 1×10 -7 Torr. An argon gas flow rate was established to maintain the chamber pressure at approximately 20 mTorr. (This pressure was chosen to be near the compressive to tensile transition pressure of 18 mTorr so that adjustments necessarily performed during deposition would not be excessively large. The determination of this transition pressure was done as described by R. R. Kola et al, in Journal of Vacuum Science and Technology, B9, page 3301 (1991).)
A plasma was struck in the argon at 13.56 MHz with a power density of 1.6W/cm 2 to induce sputtering from an 8 inch tungsten target having a purity of 99.999%. After approximately 5 minutes, a shutter positioned between the target and the sample was opened. The resonant frequency, as determined from the measured voltage from the electronic circuitry and Equation 1, immediately dropped by about 2.5 KHz due to the temperature difference between the thin membrane and the thick silicon substrate. The temperature equilibrated in approximately 5 minutes. (This frequency drop in equilibration is shown in FIG. 2 in the left hand portion of the curve. Measurements were delayed slightly from initial shutter opening in this Example to allow the membrane to come into tensile stress and, thus, to avoid any possibility of membrane fracture.) The resonant frequency was then continuously monitored and the pressure adjusted so that this measured resonant frequency followed, as the deposited thickness increased, the frequency trend predicted by Equation 1 for zero stress.
The predicted resonant frequency in Equation 1, however, does not provide for temperature effects. To correct for temperature effects, the resonant frequency of the composite membrane for the final desired deposited thickness was empirically determined under identical deposition conditions using a series of control samples. In these samples, the deposition procedure described in this example was followed to the final deposited thickness of 0.5 μm. The deposited tungsten was removed from half the membrane, and the membrane deflection at the resulting tungsten edge was measured using a WYKO optical interferometer. The final resonant frequency of the sample showing zero deflection (as shown in FIG. 3) for this interferometric measurement is the temperature corrected, zero stress frequency. The determined zero stress resonant frequency, under the conditions employed, was 3.85 KHz.
Adjustments during deposition were continued so that at the final thickness, the resonant frequency measured 1.1 KHz. (The resonant frequency during the run as a result of pressure adjustments to control stress is shown in FIG. 2.) The shutter was then closed, inducing the resonant frequency to increase by about 2.7 KHz since the membrane cooled substantially faster than the substrate. (This increase was compensated for so that the final room temperature frequency of the membrane was 3.85 KHz.) The sample was then allowed to cool in flowing argon for approximately 10 minutes. The sample was evaluated by removing the tungsten film from half the wafer. Straight interference fringes across the resulting tungsten edge indicated a stress very close to zero.
The same procedure was repeated for a silicon nitride membrane on a silicon substrate and a silicon nitride membrane on a glass substrate. In each case, final tungsten stresses below 10 MPa were achieved. | X-ray masks are typically made by depositing and patterning a layer of heavy metal on a thin supporting membrane. The metal layer must have a relatively low stress to prevent stress-induced deformation of the pattern. Tungsten films having excellent stress characteristics are produced by employing a continuously operating capacitance-based measurement technique to allow adjustment of the deposition conditions in rapid response to changes in stress of the film being deposited. | 6 |
RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. patent application Ser. No. 11/105,189, filed Apr. 11, 2005, which is a continuation of U.S. patent application Ser. No. 10/062,742, filed Jan. 29, 2002, now U.S. Pat. No. 6,878,122.
COPYRIGHT NOTICE
[0002] © 2006 Oregon Health & Science University. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR § 1.71 (d).
TECHNICAL FIELD
[0003] The invention pertains to the use of therapy termed “AMES,” or Assisted Movement with Enhanced Sensation, of a type described in U.S. Pat. No. 6,878,122 in the rehabilitation of patients suffering from stroke, traumatic brain injury, and other neuromuscular disorders such as cerebral palsy and spinal cord injury and, in particular, to the use of AMES therapy on a sub-population of such patients who are unable to generate movement in one or both directions at a joint, such as the wrist or ankle.
BACKGROUND INFORMATION
[0004] In the United States, stroke-related illness is the leading cause of long-term disability. Each year approximately 750,000 individuals in this country suffer a stroke, and for those who survive, a majority will be afflicted with a motor disability. There are currently 4.5 million U.S. citizens permanently disabled by stroke, with annual health-care costs of approximately $50 billion.
[0005] Neuromuscular symptoms of stroke include, but are not limited to, muscular paresis (i.e., reduced ability to activate muscles), plegia (i.e., complete paralysis of muscles), and dyssynergia (i.e., inability to activate certain muscles without inadvertent activation of inappropriate muscles in the same limb or other limbs). Often a stroke patient will be plegic at a joint for attempted movement in one direction and paretic in the other direction.
[0006] The diagnosis of plegia in stroke victims does not necessarily mean that the individual is completely incapable of activating the appropriate muscles at a joint. Rather, in many cases, the absence of movement is a result of insufficient levels of muscle activation and joint torque to achieve overt movement. Moreover, movement at a joint may be prevented by inadvertent, concomitant activation of the muscles on the wrong side of the joint (i.e., dyssynergia), whereby inadvertent activation overpowers weak activation of muscles on the appropriate side of the joint.
[0007] In certain embodiments of AMES therapy described in U.S. Pat. No. 6,878,122, which is assigned to the assignee of this patent application, patients with neuromuscular disorders receive feedback in the form of joint torque. The patients are fed back the amount of torque they are able to produce voluntarily while assisting joint motion produced by a motorized robotic device. If the patient is incapable of producing joint torque during AMES treatment, the patient receives no feedback, even if the patient's attempts to assist movement produce appropriate, but weak, activation of the appropriate muscles. Without useful feedback, these weak, but not completely paralyzed, patients are less likely to benefit from treatment.
SUMMARY OF THE DISCLOSURE
[0008] Preferred embodiments entail use of electromyographic (EMG) feedback of the electrical activity from muscles so that certain neuromuscular disorder-afflicted patients who are incapable of exerting overt torque at a joint can, during AMES treatment, receive feedback that is related to volitional muscle activation. These weak but not completely paralyzed patients can, therefore, benefit from AMES treatment.
[0009] Such use of EMG feedback expands the patient population benefiting from AMES treatment to include individuals who are capable of activating muscles voluntarily at a joint, but to a degree that is too weak to produce overt joint torque and movement.
[0010] Preferred embodiments of the invention use EMG feedback with AMES treatment to allow a patient who superficially appears to be totally paralyzed at a joint (i.e., in one or more directions) to recover to a point at which the patient can produce overt joint torque and movement. After the patient has regained some significant amount of voluntary movement, the patient may be shifted to treatment with joint torque feedback.
[0011] In addition to stroke, cerebral palsy (CP), traumatic brain injury (TBI), and incomplete spinal cord injury (iSCI) are three of several neuromuscular disorders in which apparent plegia can be produced, but in which the patient is actually capable of weakly activating the muscles crossing a joint. These non-stroke patients with apparent, but not actual, plegia may respond to rehabilitation if EMG feedback is employed in conjunction with AMES treatment.
[0012] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a pictorial view of a patient in position to be treated with AMES therapy while using visual feedback, auditory feedback, or both.
[0014] FIGS. 2A, 2B , and 2 C are diagrammatic representations of, respectively, raw (i.e., unprocessed) EMG, rectified EMG, and rectified and low-pass filtered EMG waveform traces developed during voluntary movement of an appendicular joint of a patient.
[0015] FIG. 3 is a diagrammatic representation of a simple visually presented embodiment of EMG feedback.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] AMES therapy is preferably practiced with use of a joint-ranging device that rotates the joint of a patient with concomitant vibration of lengthening muscles associated with the joint while the patient attempts to assist the joint rotation with voluntary contraction of corresponding muscles associated with the joint. A preferred joint-ranging device is an AMES rehabilitation device described in U.S. Pat. No. 6,878,122.
[0017] FIG. 1 shows a patient 10 sitting in a chair 12 supporting a wrist joint-ranging device 14 affixed to the patient's right forearm. Wrist joint-ranging device 14 is powered to rotate the wrist joint alternately in flexion and to extension directions. Two vibrators 16 (only one shown in FIG. 1 ) apply during wrist joint rotation concomitant vibration (e.g., 40 Hz-80 Hz) of lengthening muscles associated with the wrist joint while patient 10 attempts to assist the wrist joint rotation with voluntary contraction of corresponding shortening muscles associated with the wrist joint. FIG. 1 also shows patient 10 with her right lower leg secured in a foot joint-ranging device 20 affixed to the patient's shoe and to the calf just below the knee. Foot joint-ranging device 20 is powered to rotate the ankle joint alternately in flexion and to extension directions. Two vibrators 26 apply during ankle joint rotation concomitant vibration of lengthening muscles associated with the ankle joint while patient 10 attempts to assist the ankle joint rotation with voluntary contraction of corresponding shortening muscles associated with the ankle joint.
[0018] For operation of either wrist joint-ranging device 14 or foot joint-ranging device 20 , an EMG signal is typically acquired (i.e., recorded) from a patient's muscle or muscles to which pairs of electrodes 24 are attached. The EMG signal represents the differential voltage between electrodes 24 of an electrode pair, referenced to a neutral voltage obtained from an inactive location of the patient's body. Each electrode 24 may be composed of a rounded metal protuberance, typically 0.5 cm-0.7 cm in diameter and depressing the skin 1 mm-3 mm. Electrodes 24 may be embedded within an enclosure for the arm or leg, such as in an AMES rehabilitation device. Alternatively, EMG signals may be picked up by pairs of disposable electrodes 24 adhered to the patient's skin over the muscle or muscles of interest. Typically, pairs of EMG electrodes 24 are oriented parallel to the long dimension of a muscle and/or collinear to the orientation of muscle fibers within the muscle or muscles of interest. The EMG signals provide to patient 10 feedback information representing EMG activity of the lengthening and shortening muscles of interest. The feedback information identifies the degree to which patient 10 is able to assist joint rotation imparted by either wrist joint-ranging device 14 or foot joint-ranging device 20 .
[0019] The EMG signal, typically 10 μV-2000 μV in amplitude, is delivered to an EMG instrument 28 for amplification prior to visualization or other usage. Amplification is typically carried out in two stages to minimize electrical noise, near the pick-up site (e.g., ×100) and near the usage site (e.g., ×20-×50), resulting in an amplified signal in the region of 1 V. At this stage of processing, the signal is termed “raw” EMG, is both positive- and negative-going, and has a spiky appearance (e.g., FIG. 2 , line A).
[0020] To better utilize the raw EMG signal, further processing is usually carried out. Typically, the raw signal is rectified (i.e., the negative-going components are vertically flipped about 0 V to become positive-going) (e.g., FIG. 2 , line B), and the rectified signal is then low-pass filtered to smooth it (e.g., FIG. 2 , line C). This rectified, smoothed EMG signal can then be used to move a needle on a dial (not shown); to increment a number on a read-out (not shown); to move a graphic object 34 on a display screen 30 of a visual display monitor 32 (e.g., FIG. 3 ); or to modulate the intensity or frequency of a sound audible from a loudspeaker 36 in display monitor 32 (e.g., FIG. 1 ). Commercially available EMG instrumentation amplifier equipment suitable for practicing the above-described process is a Myosystem 2000 , manufactured by Noraxon USA, Inc., Scottsdale, Ariz. The electrodes are conventional ECG stick-on electrodes.
[0021] In a first preferred embodiment, the rectified, low-pass filtered EMG signal is used to move graphics object 34 (e.g., FIG. 3 ) on display screen 30 of display monitor 32 . In the example shown in FIG. 3 , the height of a bar 34 represents the instantaneous amplitude of the processed EMG signal ( FIG. 2 , line C).
[0022] In a second preferred embodiment, the rectified, low-pass filtered EMG signal is used to control the intensity, frequency, or both, of a tone or a recorded message played over loudspeaker 36 or headphones (not shown).
[0023] In a third preferred embodiment, the rectified, low-pass filtered EMG signal is used to control both visual feedback and auditory feedback, which are simultaneously presented in a goal-directed virtual-reality (i.e., video) game displayed on display screen 30 .
EXAMPLE 1
[0024] A 34 year-old female, 4 years post-stroke, with severe paresis and joint rigidity in her right wrist and fingers, was treated in accordance with the standard AMES therapy using joint torque feedback. Her wrist and fingers were paretic and spastic in the flexion direction and clinically plegic in the extensor direction. After 11 weeks of the standard AMES therapy, her flexion strength increased by 600%. In contrast, her extension strength changed from zero to negative values, that is, when she attempted to extend, she flexed. Closer examination with EMG recording revealed that her wrist and finger extensor muscles were active when she attempted to extend, but that inadvertent activation of the recently strengthened wrist and finger flexor muscles overpowered the extensor muscles. The patient was then provided EMG feedback for a total of 8 hours of therapy, after which she was better able to differentially activate the flexors and extensors of the wrist and fingers. She then returned to the standard AMES therapy using joint torque feedback. Three months later, her extensor torque had reversed from negative to positive and equaled the torque in her flexor muscles.
EXAMPLE 2
[0025] A 44 year-old male, 3 years post-stroke, with severe paresis in his left wrist and fingers, was treated in accordance with the standard AMES therapy using joint torque feedback. His wrist and fingers were paretic in the flexion direction and clinically plegic in the extensor direction. Closer examination revealed a low level of EMG activity in the extensor muscles during attempted extension, but the activity was too weak to produce overt movement of the wrist and fingers. Prior to using the standard AMES device with joint torque feedback, the patient was provided EMG feedback for a total of 6 hours of therapy, after which he was able to generate extension torque and movement of the wrist and fingers. The feedback he received during AMES therapy was then changed from EMG to torque, and he began partial recovery of upper limb use.
[0026] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims. | A method of rehabilitating a patient suffering partial or total loss of motor control of an appendicular joint caused by injury or neurological disorder but exhibiting clinically plegic (i.e., paralyzed) muscles and retaining minimal ability to weakly contract the muscles develops overt movement at a joint and ultimately leads to improved functionality. The method entails use of feedback in which the patient views and/or hears a signal related to the intensity of electromyographic (EMG) activity the patient produces in the appropriate muscles while attempting to move the paretic or plegic joint. The method is intended as an alternative form of feedback for highly disabled patients while they receive therapy using an Assisted Movement with Enhanced Sensation (AMES) device providing joint torque feedback. | 0 |
This invention relates to a method of aligning a CVD deposition mask, herein called a shadow frame, and large glass substrates on a susceptor or heated support. More particularly, this invention relates to apparatus for carrying out the alignment and support of large rectangular glass substrates, for processing and automatic exchange of the substrates into and from a processing chamber.
BACKGROUND OF THE INVENTION
The semiconductor industry has been using single substrate (silicon wafer) processing chambers for some time because the chamber volume can be minimized, contamination of the substrate has been reduced, process control is increased and, therefore, yields are improved. Further, vacuum systems have been developed, such as described in Maydan et al, U.S. Pat. No. 4,951,601, that allow several sequential processing steps to be carried out in a plurality of vacuum processing chambers connected to a central transfer chamber, so that several processing steps can be performed on a substrate without its leaving a vacuum environment. This further reduces the possibility of contamination of the substrates.
Recently the interest in providing large glass substrates with up to one million active thin film transistors thereon for applications such as active matrix TV and computer displays has been heightened. These large glass substrates, generally of a size up to about 350×450×1 mm, require vacuum processing chambers for deposition of thin films thereon. The basic methods and processing chambers, e.g., plasma-enhanced chemical vapor deposition (PECVD), PVD, etch chambers and the like, are similar to those used for depositing layers and patterning thin films on silicon wafers. A practicable system that can perform multiple process steps on glass substrates is disclosed by Turner et al Serial No. 08/010,684 filed Jan. 28, 1993 in a copending application filed concurrently herewith entitled "VACUUM PROCESSING APPARATUS HAVING IMPROVED THROUGHPUT." However, because of the large size of the glass substrates, several problems have been noted in their handling and processing in vacuum processing chambers.
During processing, the edge and backside of the glass substrate must be protected from deposition. Borrowing from the semiconductor processing art, a deposition-masking ring (or in this case, a rectangle) or shadow frame is placed about the periphery of the substrate to prevent processing gases or plasma from reaching the edge and backside of the substrate in a CVD chamber for example. The susceptor, with a substrate mounted thereon, can have a shadow frame which will surround and cover several millimeters of the periphery of the front surface of the substrate and this will prevent edge and backside deposition on the substrate. If however, the shadow frame is not properly centered with respect to the substrate during processing, the amount of shadowing that occurs on each edge of the substrates will be unequal and unacceptable.
A factor complicating the alignment of the substrate to the susceptor is the following. For proper set-up, calibration, and debugging of the automated movement of a substrate into and out of a processing chamber, it is important to be able to execute these activities at room temperature. Therefore, the chamber components which provide support and alignment for the substrates must be sized and shaped to perform similarly at room temperature as at normal operating temperature. The susceptor or support for the large glass substrate, generally made of aluminum and which is heated resistively or otherwise, has a very large coefficient of thermal expansion or CTE (about 22×10 -6 /°C.) and thus increases in size by 0.72% when heated from room temperature to a processing temperature of about 350° C. Since the type of glass in general use in the flat panel display industry has a low CTE (4.6×10 -6 /°C.), the size of the glass increases in size only about 0.15% from room temperature to 350° C. Because of this difference, when the glass plate and susceptor are heated to elevated temperatures, there is a significant difference in size between the glass and its susceptor support relative to the room temperature condition and it becomes difficult to center or maintain alignment of the heated glass plate on the susceptor. Again this contributes to non-uniformities in the amount of masking occurring along each edge plates and to unacceptable variations in the location of the deposition zone on the glass plate.
Therefore a means of centering a large glass substrate with respect to its susceptor support and to a shadow frame has been sought.
SUMMARY OF THE INVENTION
A centering pin assembly is mechanically registered to the center of the susceptor but independently movable to ensure both temperature-independent centering of a large glass substrate with respect to a heated susceptor and centering of a shadow frame with respect to the substrate. The shadow frame is shaped so as to mate with the centering pins, thereby also aligning the shadow frame with respect to the substrate.
Shaped support pins are loosely held in the susceptor by their own weight and are guided by closely fitting mating holes. These pins provide support for the large glass substrates during automatic exchange of the substrate and protect the susceptor from damage during periodic dry-etch cleaning cycles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a first embodiment of a centering pin of the invention.
FIG. 2 is a cross-sectional side view of one side of the shadow frame of the invention.
FIG. 3 is a cross-sectional view of a single substrate chemical vapor deposition (CVD) vacuum chamber for processing large glass substrates in which the centering pin assembly and shadow frame of the invention can be used.
FIG. 4, 5, and 6 are three cross-sectional side views of a centering pin and its support plate, a shaped support pin, one side shadow frame, a glass substrate, the susceptor/heated support and the chamber body. The views show all of these components in their relationships to one another in the three principal positions of the active components.
FIG. 7 is a side view of a shaped support pin of the invention.
FIG. 8 is a side view and FIG. 9 is a top view of a centering pin assembly.
FIG. 10 is a side view of a second embodiment of the centering pin.
FIG. 11 is a three-dimensional view of a third embodiment of the centering pin.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a centering pin 12 of the invention has a top surface 20 which supports a shadow frame 40 of FIG. 2 and has extending vertically from it a triangular finger 14. The finger 14 has a first, outer edge 16 sloping in one direction that mates with and centers the shadow frame 40 with respect to the centering pin assembly 220 of FIG. 8. It further has a second, inner edge 18 sloping in another direction that, if necessary, centers a glass substrate 108 disposed on its inner side before the substrate 108 comes into contact with the susceptor 113 during a loading sequence.
FIG. 2 is a cross-sectional view of a shadow frame 40 useful herein. The shadow frame 40 comprises an upper surface 42 with a lip 44 extending horizontally therefrom which is to overlie the periphery of the glass substrate 108 to thereby protect the edge and bottom of the substrate 108 from depositions. A tapered side 46 mates with the outer sloping side 16 of the centering pin 12. The shadow frame 40 in this embodiment is either ceramic or anodized aluminum, but can be made of a number of other suitable materials.
Under normal circumstances, as illustrated in FIG. 4, when a robot blade 230 is inserted into a chamber with a substrate 108 atop it to load into the chamber for processing, the position of the substrate 108 is proper and located precisely enough that no centering is necessary. But in the event that some mispositioning of the substrate 108 occurs which is within the "capture window" created by the inner sloping sides 18 of two opposing centering pins 12, the substrate 108 will be centered by the substrate being guided down the slope(s) 18 of the centering pin(s) 12 as the centering pin assembly 220 moves vertically upward and lifts the substrate 108 from the robot blade 230. An obviously similar description of the function of sloping sides 16 of the centering pins 12 applies to the establishment and maintenance of the centered condition of the shadow frame 40 when, moving upward, the centering pin assembly 220 reaches the "lift" position shown in FIG. 5. The realignment of the substrate 108 and the alignment of the shadow frame 40 to the substrate 108 is passive, being gravitationally effected by the interaction of these parts with the centering pins 12.
The substrate 108 and the shadow frame 40 are thus aligned to each other and centered on the susceptor 113 by the single component, the centering pin assembly 220. This alignment is a translational alignment in both the x- and y-axes of the plane of a substrate 108 and the plane of the shadow frame 40; and it is rotational alignment about their z-axes as a result of using four pairs of opposing centering pins 12, as illustrated in plan view in FIG. 9, which are located to act near the corners of a substrate 108 and the shadow frame 40. FIG. 9 shows how the centering pins 12 are arranged in four opposing pairs (8 pins total) in order to provide centering translationally and rotationally for the rectangular substrate 108 and the shadow frame 40.
The centering pin assembly 220 and most importantly the pin support plate 122 are made of a material having a low coefficient of thermal expansion (CTE). In this embodiment it is alumina, which has a CET of about 7.4×10 -6 /°C. and therefore exhibits a dimensional change similar to that of the glass substrate 108 of only about 0.24% from room temperature to processing temperatures of about 350° C.
FIG. 3 is a cross-sectional view of a single-substrate CVD processing chamber useful for depositing thin films onto large glass substrates and in which the novel centering pin assembly and shadow frame are used.
A vacuum chamber 120 comprises a chamber body 102 and a lid 103 attached by a hinge to the body 102. A gas dispersion plate 104 having a plurality of openings 106 therein for the distribution of reaction gases is mounted in the lid 103. The shadow frame 40 is supported by a ledge 110 on the inner surface 112 of the wall 102 during the time that the substrate 108 is entering or exiting the chamber 120 through an entry 126. The susceptor/heated support 113, mounted on ceramic support 114, can be moved up and down by a shaft 118 in conventional manner. As shown, the susceptor 113 is between its down or loading/unloading position of FIG. 4 and the lift position of FIG. 5. The susceptor 113 supports the substrate 108 to be processed on its upper surface 116 when it is in its up or processing position of FIG. 6.
A plurality of centering pins 12 rigidly mounted on the separate pin support 122 make up the centering pin assembly 220 of FIG. 9. This assembly is also movable up and down by the shaft 118 but is separately mounted on an outer shaft 124. For example, a guiding bearing on the susceptor shaft 118 allows the centering pin assembly 220 and the susceptor support 114 to be separately movable. The positions of the centering pins 12 are fixed with respect to their support 122 so that the glass substrate 108 to be processed will be centered with respect to the centering pins 12. The pin support 122 is located below the susceptor 113 and its support 114, and the centering pins 12 pass through holes in these parts.
FIG. 7 shows a shaped support pin 200, a plurality of which are used to support the substrate 108 during loading and unloading of the substrate onto and off from the robot blade 230. These pins 200 are floating under their own weight in the susceptor 113 and are forced by contact at their bottom with the centering pin support 122 to protrude through the susceptor 113 when the susceptor is in the lift position of FIG. 5 or the load position of FIG. 4. Because the component(s) (in this embodiment, the shaped pins) which lift the substrate 108 from the susceptor 113 must be beneath the substrate, (an) access hole(s) 117 must penetrate the susceptor 113 and its support 114 to allow the lifting device(s) through. However, if the hole is not covered beneath the substrate 108, several deleterious effects can occur including loss of temperature control at that spot on the substrate, and, in the case of plasma enhanced deposition or etch clean process, the discharge is greatly enhanced which is produced at such discontinuities as a hole in the surface 116 creates. Subsequent thermal or sputtering damage to the hole surfaces can result. Therefore the shaped support pins 200 are designed to float within the susceptor and be carried with the susceptor 113 as it moves above the lift position of FIG. 5 into the process position of FIG. 6. The top of the shaped support pin 200 has a tapered bottom surface 205 which fits tightly inside a mating tapered surface 115 in the susceptor 113, which thereby effectively seals the hole 117 in the susceptor 113. The shaped support pin 200 is then suspended in the susceptor 113 by the fit of support pin surface 205 inside susceptor surface 115 when the susceptor is in the process position of FIG. 6. In this position, the top surfaces 202 of the shaped support pin 200 should be either flush with or slightly under flush with the top susceptor surface 116.
The substrate load sequence is as follows. A glass substrate 108 supported by a robot blade 230 enters the vacuum chamber 120 through the entry port 126 while the susceptor 113 and centering pin assembly 220 are in the down position of FIG. 4. The shaped pins 200 contact at their lower ends the pin support plate 122 and their top surfaces 202 are generally horizontally aligned with the bottom of the inner sloping edges 18 of the centering pins 12. The centering pins 12 are raised up to support and if necessary center the glass substrate 108 with respect to the susceptor 113. In moving to the lift position of FIG. 5, the glass substrate 108 is centered by the sloping sides 18 of the centering pins and supported by the top surfaces 202 of the shaped pins 200 protruding above the susceptor 113. The robot blade 230 is withdrawn, and the entry port 126 is closed. The centering pin assembly 220 continues to move upwards along with the shaped support pins 200 until the edges 18 of the centering pins 12 contact the tapered sides 46 of the shadow frame 40. The shadow frame 40 is at once lifted upwardly away from the ledge 110 of the wall 102 and centered with respect to the shadow frame 40 and the substrate 108. The shadow fame 40 is thereby centered, if needed, and supported in its centered position as the centering pin assembly 220 is raised together with the susceptor 113 into the lift position of FIG. 5. At this point in the vertical motion, the centering pin assembly 220 reaches a stop and does not rise any higher. The susceptor 113 is now raised until it supports the glass plate 108 and the lip 44 of the shadow frame 40, so that the shadow frame 40 is now supported solely by the substrate 108. At this point, the shaped pins 200 are lifted off the pin support plate 122 by the rising susceptor 113 and become flush with the top susceptor surface 116. The final processing position of the glass substrate and the shadow frame is shown by means of dotted lines at 108A and 40A in FIG. 3 and in detail in FIG. 6. Since the glass substrate 108 and the shadow frame 40 can be made to have similar coefficients of thermal expansion, their relative size does not change with respect to each other during processing and the shadow frame 40 remains centered with respect to the substrate 108.
The reactant gases are fed through the gas dispersion plate 104 and processing is completed. The susceptor 113, the substrate 108 and the shadow frame 40 are then lowered to the lift position of FIG. 5, whereat the robot blade 230 is inserted. The susceptor 113 and centering pin assembly 220 then are lowered together. The substrate 108 deposited on the robot blade and the processed glass substrate can be removed from the chamber 120.
A simpler but less preferred embodiment of the invention is illustrated in FIG. 10. When the robot arm 230 places the substrate 108 within the chamber, the sloping inner sidewalls 18 center the substrate 108 as the centering assembly 220 is raised. The centered substrate 108 rests on inner, horizontally extending ledges 19 of the centering pins 12 before the susceptor 113 lifts the substrate 108 from the inner ledges 19 to engage and lift the shadow frame 40 from the centering pins 12. The embodiment of FIG. 10 does not require the shaped pins 200 because the inner ledges 19 perform the substrate-support function of the shaped pins 200, as shown in FIG. 5. However, the holes 117 in the susceptor 113 which allow the centering pins 12 to pass through must extend correspondingly further toward the center of the susceptor 113, and therefore the frame lip 44 must be longer if it is to cover the larger hole in the susceptor 113. The longer lip 44 however has the undesirable effect of reducing the usable processed area of the glass 108, and, as previously described, the uncovered hole can have deleterious effects on the substrate 108 or the susceptor 113.
A third embodiment of the invention is illustrated in three dimensions in FIG. 11. Four corner pins 212 rise from the four corners of the pin support plate 122. The intervening susceptor in not illustrated. Two perpendicular triangular wedges 213 and 214 rise from a flat surface 215 at the top of the corner pins 212. The substrate 108 is centered at its corners 216 by the inner sloping surfaces 217 of the wedges 213 and 214, and its corners 216 are supported by the inner portions of the top pin surface 215. The masking frame 40 is centered by the outer sloping surfaces 218 of the corner pins 212 and is supported by the outer portions of the top pin surfaces 215. Four such corner pins 212 perform the same functions as four pairs of centering pins 12 of FIG. 10.
Although the invention is described herein in terms of certain specific embodiments, the centering pins, shadow frame and support pins can be employed in apparatus other than CVD chambers and various materials and chamber parts may be substituted as will be known to one skilled in the art. The invention is meant to be limited only by the scope of the appended claims. | Centering pins mounted to a susceptor in a vacuum chamber align a glass substrate with respect to the susceptor on which it is supported, and with respect to a shadow frame which overlies the periphery of the substrate and protects the edge and underside of the substrate from undesired processing.
Shaped pins loosely mounted in openings in the susceptor so that the pins extend above the upper surface of the susceptor support the centered glass substrate during the transporting stages, but recess into the susceptor during processing. | 2 |
This invention relates to a walkway assembly and in particular, though not exclusively, to a walkway assembly for use externally such as on the roof of a building.
The term “walkway” is used herein to relate both to a substantially horizontally extending or slightly inclined surface over which personnel may walk and also to a series of steps which may be in the form of a stairway to assist personnel to move over more steeply inclined surfaces or between two levels.
BACKGROUND OF THE INVENTION
There is a particular need to protect roof structures from damage by maintenance and other personnel moving thereover, and to assist in ensuring the safety of such personnel. Such needs include also the provision of roof-top fire escape routes. In response to these needs it is well known, particularly for industrial and commercial premises, to construct on a roof top both continuous walkway assemblies, which may be level or slightly inclined, and also series of steps in the form of stairways for movement of personnel over more steeply inclined surfaces or between two levels.
The variety of roof pitch angles and the distances over which a walkway is to be provided has meant that in general bespoke on-site construction work is necessary. However the relative difficulties typically encountered when working in a roof top environment, and exposure to weather, makes it particularly advantageous to provide means for minimising or simplifying the on-site construction work.
Another requirement that needs to be taken into account is that of ensuring that the tread surface does not of itself present a significant safety hazard.
Disadvantages of many known walkway assemblies include difficulty of and time for off-site design work, on-site construction, relative expense, cost of component parts and relatively high weight.
SUMMARY OF THE INVENTION
The present invention seeks to provide an improved walkway assembly in which at least some of the aforementioned disadvantages of known types of walkway assemblies and components therefor are mitigated or overcome.
In accordance with one aspect of the present invention there is provided a walkway assembly for attachment or attached to a support structure, said assembly comprising:—
a primary support for on-site attachment to the support structure; a plurality of tread modules each attached relative to the primary support and moveable between a first position and a second position at which a part of each module is spaced further from the primary support than when at the first position, and at least one riser unit for supporting the tread modules relative to the primary support in at least the second of the first and second positions.
The primary support may comprise two primary support members which lie side by side in spaced apart relationship and extend in parallel with one another in the direction of the length of the walkway assembly. In this case transverse spacers may be provided to extend between the support members to maintain the support members spaced apart, and/or the tread modules may serve to perform a spacing function. However the primary support may be of a different configuration and may, for example, comprise a single elongate member relative to which the tread modules are attached.
Preferably each tread module is secured pivotally relative to the primary support.
Each tread module may be supported by an auxiliary support that is secured, for example pivotally, relative to said primary support. Said auxiliary support may comprise two auxiliary support members which lie side by side in spaced apart relationship and extend in parallel with one another. As viewed in a direction perpendicular to the primary support, said auxiliary support members may extend substantially parallel with the length of the primary support.
A walkway assembly may comprise a single or a plurality of auxiliary supports.
For forming a walkway to be used as a stairway the walkway assembly, such as a pre-formed module, may comprise a plurality of auxiliary supports and each auxiliary support may be employed to support one or a plurality of tread modules. Said auxiliary supports in this case may each be pivotally secured to the primary support, each for pivotal movement about respective axes which extend substantially perpendicular to the length of the primary support.
If the primary support comprises a pair of spaced apart primary support members, each primary support member may have secured thereto a plurality of auxiliary supports each of a kind comprising a pair of auxiliary support members and with each of the auxiliary support members of a pair being secured to a respective one of the two primary support members. In this case riser units preferably are provided to extend between each of the primary support members and distal regions of each of the auxiliary support members.
For a modular walkway assembly to be used as a traverse walkway to extend substantially horizontally over an inclined roof or other support structure a walkway assembly module may, for example, comprise only a single auxiliary support to which all of the tread modules of the walkway assembly module are secured. In this case said auxiliary support may be secured pivotally relative to the primary support for pivotal movement about an axis which extends substantially parallel with the length of the primary support.
If the primary support comprises a pair of spaced apart primary support members, one primary support member of a traverse walkway may have an auxiliary support pivotally secured thereto and the other primary support may provide location and support for at least one said riser unit which extends to and supports the auxiliary support at a position remote from the primary support member to which the auxiliary support is pivotally secured. As in the case of a stairway module, the auxiliary support may comprise a pair of auxiliary support members that are inter-connected by and provide support for the plurality of tread modules. One of the auxiliary support members may be pivotally secured relative to one of a pair of primary support members and the other auxiliary support member may be inter-connected with the other of said primary support members by one or more said riser units.
From the foregoing description of one aspect of the present invention it will be appreciated that a walkway assembly advantageously, though not necessarily, may be constructed off-site as a pre-formed module and thereby reduce substantially the work needed to be undertaken on-site in conditions which generally are significantly less favourable than off-site. By providing pre-formed modules of different lengths, such as two different lengths (for example 1.5 meter (5 feet) and 3 meter (10 feet) lengths and in view of the fact that on-site tailoring of the length of the walkway often will not be critical to within a few meters, the need to expend time in on-site or off-site cutting to length is avoided or at least significantly minimised. As will also be apparent from the description given below, the primary supports of two modules may be of a kind that readily enables them to be structurally inter-connected thereby to provide a walkway surface devoid of any significant gaps or abrupt changes of deflection characteristics.
A further potential advantage arising from the use of pre-formed modules is that there is a significant reduction in the need for detailed on-site survey work and measurement. For many applications the only necessary on-site survey work will be that to establish the length of a walkway run and, in the case of a traverse walkway or stairway, the angle of inclination of the support structure and the type of roof surface to which the primary support of the walkway module is to be secured.
The facility for the auxiliary support to be moveable relative to the primary support advantageously allows a module size to be minimised for transportation and, by use of adjustable riser units, for a single module construction to be employed on-site in situations having different angles of inclination to the support structure. However, optionally a module may comprise riser units that can extend to and be lockable at only a single, pre-determined second position. Optionally, alternatively or additionally, a module may comprise riser units that are lockable at the first position,
It is not, however, essential that the walkway assembly be of a modular type and the present invention further provides walkway assemblies of a type that are suitable for either modular off-site construction or bespoke on-site construction.
In accordance with another aspect of the present invention there is provided a walkway assembly comprising a pair of primary support members which lie side by side in spaced apart relationship and extend in parallel with one another in the direction of the length of the walkway, and a plurality of tread modules which are each supported relative to the support members, each primary support member comprising a side face which comprises a groove formation for location of the primary support member relative to at least one of a support structure and another support member.
The tread modules may be secured directly to the support members, for example to upper surfaces of the support members, or they may be secured to an auxiliary support that is secured relative to the primary support members. Said auxiliary support may be moveable relative to the primary support members and may comprise one or more of the other features described herein in respect of an auxiliary support.
Preferably each said support member comprises two side faces each having a groove formation.
Preferably the or each said groove formation is provided in a side face which extends substantially perpendicular relative to an upper support surface of the support member.
It is further preferred that the support member has a cross-sectional shape which is symmetrical about two mutually perpendicular axes, for example one parallel with a side face or upper support surface and the other perpendicular relative thereto.
Each groove formation may define a channel which is generally of a C shape in cross section whereby within the groove there are two abutment surfaces each of which lies at a respective side of the groove opening.
Suitable materials for the support members include metals such as aluminium and steel (typically galvanised) and also plastics such as a polyamide (e.g. nylon) or a composite such as glass reinforced polyamide.
The groove formations preferably are open ended to allow for ease of insertion of components such as the heads of securing means, such as bolt heads or nuts employed in use for securing the support member to a connector for connection of two lengths of support members or to a retainer (e.g. a clamp or retention bracket) by means of which the support member may be retained relative to a support structure such as a roof structure.
The support members may be tubular in cross-section. End caps may be provided to close the ends of the tubular passages of the support members and also to serve to provide a protective cover over any sharp edges which may be present at a cut end of a support member. End caps may extend over ends of the groove formations or may leave the groove formations open-ended. The end caps may be of moulded plastics and may be secured in position as a friction fit.
The walkway assembly, whether or not in the form of a module, may comprise straight connectors such as metal strips for joining two lengths of support members end to end, each strip being provided with apertures for securing means. A connector may be secured to a side face of a support member by a bolt the head of which lies within the groove whereby a nut secured to the outer end of the bolt enables a part of the connector to be clamped to one of the support members. A connector may be positioned internally within a groove and may be similarly secured relative to the support member by a securing means that extends outwards through an aperture in the connector, or the connector may be provided with a threaded aperture for engagement by a bolt that extends inwards into the groove. Other shapes of connectors may be used, e.g. right angled connectors or connectors having two limb portions inclined relative to one another at an angle other than a right angle.
Thus it will be appreciated that the provision of a primary support having a said groove formation allows two primary supports readily to be joined end to end or, for example, at right angles relative to one another.
The retainers for attachment to the support structure may be substantially similar to those already well known, but adapted as may be necessary to enable them to be secured readily relative to the grooved side face of a support member.
The tread modules may be of a kind as described in our co-pending UK patent application GB 0921366.1 and entitled Tread Module.
The tread modules preferably are of a kind having a width (as considered perpendicular to the length of the walkway) which is greater than the depth of the module and preferably the width is between four times the depth and twice the depth, more preferably between three times and twice the depth.
Each step of a stairway may comprise only one or a plurality of tread modules. The tread modules may be of a kind severable to form a sub-module as described in our aforementioned patent application. One or more sub-modules, with one or more whole tread modules, may be provided at a step position so as to provide an appropriate depth of tread surface for the particular angle of inclination of the stairway. Similarly, a horizontal walkway section may comprise a plurality of whole tread modules and one or more sub-modules.
For a walkway which is to extend over a roof or other support structure which lies at a significant angle of inclination the present invention teaches that primary support members may be positioned substantially parallel with and be supported by the inclined surface and that riser units are employed to enable tread modules to be supported in the substantially horizontal orientation, for example to be supported on one or more auxiliary supports. Similarly riser units may be employed to form a stairway that connects between two levels without the presence of an inclined surface for support of the primary support members. For forming a walkway that traverses horizontally over an inclined roof structure riser units may be employed to locate one of a pair of auxiliary support members at a position elevated above the roof surface.
The riser units may be of adjustable effective length and may be employed in the formation of a stairway assembly that does not necessarily incorporate support members having a grooved side face.
Thus in accordance with another aspect of the present invention there is provided a walkway assembly for movement of personnel over an inclined surface or between two levels, said walkway assembly comprising a pair of primary support members which lie side by side in spaced apart relationship and extend in parallel with one another in the direction of the length of the walkway, and a plurality of tread modules which each extend between and are supported relative to the primary support members, one edge of each tread module lying closer to one or each of the primary support members than an opposite edge of the tread module and said plurality of tread modules being supported by riser units each of which is of an articulated type comprising two leg sections the relative angle of which is selectively adjustable
The end of one leg section of each riser unit preferably is pivotally securable to a support member lying on and or supported by the support structure and the end of the other leg section is pivotally securable relative to the tread module, e.g. an auxiliary support member to which the tread module is secured. The riser unit preferably possesses the further feature that the other ends of the two leg sections comprise pivot positions whereby the leg sections may pivot relative to one another, and locking means may be provided to enable the two leg sections to be locked either parallel with one another or at a chosen angle of relative inclination whereby the effective length of the riser unit may be adjusted to that required to enable the or each tread module to be supported in a substantially horizontal orientation.
Optionally one or each of the leg sections may be provided with a plurality of pivot positions, such as the positions of pivot pin apertures, whereby for a given angle of relative inclination of the leg sections the effective length of the riser unit may be adjusted.
The locking means may comprise for example a retention pin or nut and bolt which extends through an aperture provided in one leg section at a position off-set from the pivot position in said other end of the one leg section and one of a series of apertures provided in said other end of the other of the two leg sections, said series of apertures comprising apertures each off-set from the pivot position of that leg section and said apertures of the series being circumferentially spaced from one another about said pivot position. In consequence by appropriate selection of that aperture of the series through which the locking means extends the selected effective length of the riser unit may be secured against further relative movement of the leg sections under the action of loads carried by the tread module(s).
The riser units may be of a type that limit the maximum angle of movement of tread modules away from the primary support member.
In the case of a stairway assembly module the riser units may be of a type which can adopt a first position in which they allow the outer, leading edge regions of one tread module to lie in an overlapped manner over the inner edge of a neighbouring tread module.
A tread module positioned on an inclined surface may be supported by an auxiliary support member of a kind having a side face with a grooved formation substantially as described herein for the aforementioned support members whereby the end of one leg section of a riser unit may be secured to that auxiliary support member.
For a walkway assembly in the form of a stairway the tread modules (and including any sub-modules) may each be supported by a pair of auxiliary support members one end of each of which is secured, e.g. pivotally, to a primary support member which lies substantially parallel with the surface of the inclined support structure (or extends between two levels) and the distal end region of which is secured to an end of said riser unit.
For a walkway assembly which is in the form of a substantially horizontally extending walkway that extends over an inclined support structure the riser units may be employed to support an outer auxiliary support member that extends parallel with the length of the walkway to support outer regions of tread modules. The inner ends of the tread modules may be supported by another auxiliary support member that serves as an inner support member to support regions of the tread modules nearest the inclined support structure. That inner auxiliary support member may be pivotally secured to support members which lie substantially parallel with the surface of the inclined support structure.
An auxiliary support may be secured to a primary support by pivot means that is attached to a surface of the primary or auxiliary support which is in a plane substantially parallel with a tread module surface or surface of a support structure. However, and especially if the primary and/or auxiliary support comprises a support member having a side face which comprises a groove formation, the pivot means may be secured to said side face.
For forming an installation comprising a substantially horizontally extending walkway and a stairway, and irrespective of whether the horizontal walkway and stairway are aligned in a common direction or, for example, extend at right angles relative to one another, a tread module of the stairway may be arranged to form a part of the walkway or a tread module of the walkway may be positioned to serve as an upper or lower tread of the stairway.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:—
FIG. 1 is a perspective view of part of a walkway installation in accordance with the present invention;
FIG. 2 is a cross-sectional view of a support beam of the assembly of FIG. 1 ;
FIGS. 3 a & 4 a each show means for securing a support beam to a roof structure, and FIGS. 3 b and 4 b show exploded views of features of FIGS. 3 a and 4 a , respectively;
FIGS. 5 a and 5 b show means for connecting two support beams end to end, FIG. 5 b showing an exploded view of a feature of FIG. 5 a;
FIGS. 6 a and 6 b show means for securing two support beams at right angles relative to one another, FIG. 6 b showing an exploded view of a feature of FIG. 6 a;
FIG. 7 shows part of the stairway of FIG. 1 ;
FIG. 8 shows in exploded form components of the stairway of FIG. 7 ;
FIG. 9 is a perspective of a traverse walkway, and
FIG. 10 is an end view of another transverse walkway.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A walkway 10 (see FIG. 1 ) for a support structure in the form of roof comprising a flat section and an inclined section comprises a horizontal walkway assembly module 11 and a stairway assembly module 12 .
The walkway and stairway assemblies 11 , 12 each comprise a pair of mutually parallel primary support members each in the form of a beam 13 , the two support beams lying side by side in spaced apart relationship.
Each beam 13 (see FIG. 2 ) is an aluminium extrusion comprising an upper support surface 14 and a pair of side face walls 15 each of which is grooved such that in each side wall there is an opening 16 to a substantially C shaped retention channel 17 as viewed in transverse cross-section.
The channels 17 in each side face are of the same cross-sectional shape and comprise a pair of abutment surfaces 18 disposed respectively above and below the opening 16 . The cross-section of each channel departs from an exact C shape in that the channel has upper and lower recess regions 19 whereby, for a purpose described below, a rectangular-section plate may locate and be supported in upright manner in the channel. Additionally the base region 20 of each channel defines a recess that may, for example, accommodate the head of a bolt that extends through an inserted plate and outwards of the opening 16 , and may act to prevent rotation of the bolt head.
In the case of a roof or other support structure that comprises a rib formation, such as a standing seam, the beams may each be secured to the roof by clamps 25 (see FIG. 3 ) comprising in cross-section a pair of limbs 26 which can be clamped together by bolts 27 to embrace the rib. One of the limbs has an integral flange formation 28 to which is secured a clip 29 having a hook shaped end 30 that fits in the beam opening 16 thereby to secure the beam against the flange formation when a nut 31 is tightened to draw the clip downwards towards the flange formation.
In the case of a roof structure having a surface to which a retainer bracket may be bolted, the channel of a beam may be used non-rotatably to locate a bolt 32 a that extends outwards and through one limb 33 a of an L shaped bracket 34 (see FIG. 4 ) to enable the bracket to be bolted firmly to the beam. The other limb 33 b of the bracket is formed with an opening to enable the bracket to be secured by a bolt or self-tapping screw 32 b to the roof structure.
In addition to facilitating ease of attachment of a primary support beam to a roof structure the grooved side walls also facilitate ease of connection of two lengths of the beam in an end to end manner or to form a right angled interconnection, such as a T junction, between two lengths as shown respectively in FIGS. 5 and 6 . In each of FIGS. 5 and 6 a first beam section 35 has secured thereto a connector 36 or 37 by means of a bolt the head of which is non-rotatably secured in the channel recess 20 with the outer end of the bolt being accessible for location of a nut to enable the connector to be tightened against the beam side wall. In the case of FIG. 5 the connector is in the form of a flat plate having two apertures whereby it may serve to interconnect between two bolts provided respectively in ends of the two lengths of beam. In the case of FIG. 6 each connector is an L shaped right-angled bracket to enable a T section junction to be created.
Prior to or, or optionally, after securing the beam sections to a roof or other support structure tread modules 41 (see FIG. 1 ) are secured to the upper surfaces 14 of the beams by means of self tapping screws which locate in recesses 38 in the tread modules. These tread modules may, for example, be of the kind described in our aforementioned co-pending UK patent application GB 0921366.1.
In this embodiment the angle of inclination of the stairway 12 is such that a single module 41 would not provide a suitable depth of tread. Thus at each step position there is provided a whole module and a one third sized sub-module section 40 which has been formed by cutting of a whole module.
The stairway assembly 12 comprises a pair of spaced apart beams 13 secured to the inclined surface of the roof structure in a manner as aforedescribed for the horizontal walkway assembly 11 .
For each tread position (see FIG. 7 ) each beam has an auxiliary support beam 45 secured thereto. Each auxiliary beam is secured pivotally relative to a support beam 13 by means of a hinge 46 (see FIGS. 7 and 8 ) the arms of which are secured by self-tapping screws respectively to an upper surface 14 of a beam and underside surface 47 of auxiliary beam 45 . Exposed ends 58 of each auxiliary beam 45 are covered by protective end caps 39 which are each an interference fit in the end of a beam.
The distal end 58 of each auxiliary beam 45 is supported by an articulated riser unit 48 comprising two leg sections in the form of pivotally interconnected arms 49 , 50 one, 49 , of which is pivotally connected and secured to the beam 13 and the other arm 50 being pivotally connected and secured to the distal end 58 of the auxiliary beam 45 .
The ends of the leg sections are secured by bolts 51 , 52 respectively to the support beams 13 and distal end regions 58 of the auxiliary beams 45 .
The leg sections are each pivotally interconnected by a nut and bolt assembly 53 that extends through pivot apertures 54 , 55 .
When the arms are at a chosen angle of relative inclination they are locked relative to one another by a lock pin 59 inserted through a second aperture 56 in one leg section and which is aligned with one of a series of apertures 57 provided in the other leg section and circumferentially spaced relative to the pivot aperture 54 .
Accordingly, the facility for varying the relative inclination of the leg sections of each riser unit, the position at which an end is secured to a support beam 13 , and, optionally, also to the auxiliary beam 45 provides for ease of on-site adjustment to ensure that the tread modules 41 are acceptably level.
The riser units may be employed also for the construction of a traverse type walkway for extending horizontally over an inclined roof surface as shown in FIG. 9 . Tread modules 60 are secured to a pair of auxiliary support beams 61 , 62 one 61 of which is pivotally secured by hinges 63 relative to a roof mounted primary support beam 64 secured to a roof structure. The other auxiliary support beam 62 is maintained elevated relative to another roof mounted primary support beam 65 by riser units that correspond substantially with the aforedescribed riser units 48 . In this configuration the ends of each riser unit are not secured directly to the groove in a beam side wall. Instead end brackets 66 are employed each to pivotally connect with an end of a leg section and secure it to either the underside of beam 62 or upper face of beam 65 .
In an alternative construction for a traverse walkway module, see FIG. 10 , U shaped brackets 70 are attached to the respective ends of each riser unit 48 and allow attachment to the grooved side walls of the beams 62 , 65 . Also, instead of the aforedescribed hinge 63 , use is made of hinges 72 which are secured to the grooved side walls of the beams 61 , 64 . In this and the aforedescribed embodiment the primary support beams 64 , 65 are each secured, in use, directly to a roof surface and additionally are maintained spaced apart by cross beams 73 having grooved side walls. That is, the cross beams form part of a prefabricated traverse walkway module. | A walkway assembly ( 10 ) for attachment to a support structure such as a roof of a building includes a primary support ( 13 ) for on-site attachment to the support structure, a plurality of tread modules ( 41 ) each attached relative to the primary support and moveable between a first position and a second position at which a part of each tread module is spaced further from the primary support than when at the first position, and at least one riser unit ( 48 ) for supporting the tread modules relative to the primary support in at least the second of the first and second positions. | 4 |
TECHNICAL FIELD
[0001] The present invention relates to a means and method for creating subterranean excavations and/or constructions. For the purpose of this specification, the term construction is intended to include, but not be limited to, piers, retaining walls, piping, ceilings, floors, barriers and filters.
BACKGROUND ART
[0002] In this specification unless the contrary is expressly stated, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not to be construed as an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge; or known to be relevant to an attempt to solve any problem with which this specification is concerned.
[0003] When excavating down to a required level for whatever reason, it has hitherto been necessary to excavate the walls of the excavation site at approximately 45° in order to prevent the earth walls from collapsing inwardly on the excavation site. Only once the desired base level had been reached could work commence on the construction of a structure or construction in the excavation.
[0004] Methods of shoring the walls of an excavation have been developed which allow a trench or bore etc with vertical walls to be dug, thus reducing the size of the excavation and the amount of earth that needs to be excavated.
[0005] Shoring methods have included such techniques as using structural elements to brace the excavation, and even filling a hole with a slurry while the excavation is taking place.
[0006] However, these shoring operations can be time consuming and therefore costly.
[0007] It is an object of the present invention therefore to provide a means and method of creating subterranean excavations and/or constructions that substantially ameliorates the aforementioned difficulties associated with known excavation techniques, or at-the least, provide the public with a useful alternative.
[0008] It is a further object of the invention to provide a means and method of creating a subterranean excavation and/or construction that involves excavating as little material as possible.
[0009] Other objects and advantages of the present invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present Invention is disclosed.
[0010] For the purpose of this specification the word “comprising” means “including but not limited to”, and the word ‘comprises’ has a corresponding meaning.
DISCLOSURE OF THE INVENTION
[0011] In one form of this invention although this may not necessarily be the only or Indeed the broadest form of this there is proposed a system for creating a subterranean construction including an excavation means adapted to excavate a first material from a subterranean position, means for clearing this first material from the excavation site, and means for supplying the void left by the excavation with a supply of a second material that is dissimilar to the first material.
[0012] In a further form, the invention may be said to reside In a method of creating a subterranean construction by excavating and removing a first material from a subterranean position, and backfilling the void left by the excavation and removal with a supply of a second material that is dissimilar to the first material.
[0013] Preferably, the second material is adapted to form, at least in part, the construction.
[0014] Preferably, in an alternative, the second material is a granular material.
[0015] Preferably, the subterranean position is a bore, shaft or tunnel.
[0016] Preferably, the bore or tunnel is approximately horizontal.
[0017] Preferably, the excavation means is adapted to excavate in any desired direction away from the subterranean position, so that this position is a starting positing for the excavation and construction process.
[0018] Preferably, the void left by the excavation is pressurised with the second material, and this second material exerts pressure on the excavation means that drives it in the desired direction.
[0019] Preferably, the excavation means is adapted to excavate upward from the first subterranean position.
[0020] Preferably, in an alternative, the excavation means Is adapted to excavate downward from the first subterranean position.
[0021] Preferably, the excavation means includes at least one digging tooth.
[0022] In one form, the or each tooth is supported by means which are driven so as to provide a cutting action.
[0023] Preferably, the or each tooth is supported by means which are driven so as to reciprocate.
[0024] In one form, said tooth support means is a chain.
[0025] In a further form, the chain is continuous, and passes around at least a pair of sprockets, at least one of which are driven.
[0026] Preferably, the chain is driven by a power source.
[0027] This power source may be a hydraulic, electric or internal combustion motor.
[0028] Preferably, the second material is adapted to solidify
[0029] Preferably, the second material is a cementious material.
[0030] Preferably, the material that is adapted to solidify is a concrete slurry.
[0031] Preferably, the means for clearing excavated material does so by entraining this material in a fluid stream.
[0032] Preferably, said means creates a flow of the fluid at or neat the excavation face, for the purpose of entraining excavated material and removing this from the excavation site.
[0033] Preferably, the fluid is air.
[0034] Preferably, pumping the second material into the void left by excavation, forces the excavation means upwardly or in the desired direction of excavation if this is not upwardly.
[0035] In a further form, the invention may be said to reside in a method of utilising the abovementioned means for creating a subterranean structure comprising the steps of drilling a pair of vertical bores, drilling a horizontal bore between the vertical bores, inserting the means for creating a subterranean structure into the horizontal bore so that it can then excavate in the desired direction, and backfilling the void left by excavation with a second material that is dissimilar to the first material.
[0036] Preferably, the horizontal bore is sealed at both ends in order to prevent the second material from filling the vertical bores.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] For a better understanding of this invention it will now be described with respect to an embodiment which shall be described herein with the assistance of drawings wherein;
[0038] FIG. 1 is a not to scale, schematic view of the system; and
[0039] FIGS. 2 and 3 are cross-sectional views through the horizontal bore in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0040] Referring now to FIG. 1 , where there is a pair of substantially parallel, vertically spaced apart bores 2 , called ‘guide’ bores, having a horizontal, or ‘excavating’ bore 4 passing between them proximate to their ends. The horizontal bore 4 is drilled at the required depth i.e. if the construction, which for the purposes of this example is a wall, is to be constructed to a depth of 5 meters below ground level, the horizontal bore 4 is dug at this depth.
[0041] The equipment for forming the subterranean structure is then directed down into the bores and set up in the following fashion.
[0042] A wear strip 6 is passed between the two vertical bores 2 via the horizontal bore 4 , the wear strip 6 being sized and adapted to seal against the sides of the horizontal bore 4 along its edges so as to create a cavity above the wear plate 6 , and one below it.
[0043] The wear strip 6 supports a chain 8 on its upper side in guide tracks 10 , so that the chain 8 be driven with a reciprocating motion with respect to the wear/seal strip 6 . Connected to the chain 8 is a plurality of sets of upwardly directed digging teeth 12 , which, when the chain is driven, have a cutting action.
[0044] Formed into the underside of the wear strip is a pair of passageways 14 with a series of holes 16 passing through the walls thereof along their respective lengths. Each end of these passageways 14 is then connected to a conduit 20 that supplies it a second material, which for the purposes of this example is concrete, from a source 22 up at ground level.
[0045] A further conduit is fed down each one of the vertical bores 2 to the end of the horizontal shaft 4 just above the wear plate 6 .
[0046] In use, concrete is supplied via the conduits 20 to the passageways 14 running in the under or sealing side of the wear strip 6 , this concrete then passes through the holes 16 in the walls of these passageways and out into the cavity below the wear strip 6 . Concrete 19 continues to be pumped into this cavity until sufficient pressure is reached in this lower cavity that the concrete begins to force the wear strip 6 upwards towards ground level.
[0047] As it does this, the chain 8 is being driven so as to reciprocate from side to side. As the wear strip 6 is forced upwardly by the pressure of concrete 19 beneath it, so to are the digger teeth 12 forced upwardly, and these are also reciprocating with a cutting action by virtue of their attachment to the chain 8 . When these digger teeth 12 come into contact with the roof of the. horizontal bore 4 , they cut away at and excavate earth, which falls from the ceiling of the bore 4 .
[0048] One of the pair of further conduits 30 provides a fluid, which for the purposes of this example is air, at pressure to the cavity above the wear strip 6 , and the other conduit 32 provides a source of vacuum. Between them they create air movement along the upper cavity of the horizontal bore 4 from one end to the other, which is sufficient to entrain the excavated earth therein, and this waste material extraction line 32 draws this earth up to ground surface.
[0049] As the concrete 19 cures, it forms a subterranean wall 40 in the ground without the need to excavate additional earth beyond that which had to be displaced in order to allow the wall 40 to be formed in the first place.
[0050] So long as concrete 19 is continued to be pumped into the cavity below the wear strip 6 , the wear strip 6 , chain 8 , digging teeth 12 , and the other ancillary equipment associated with these, will continue to be displaced upwards by the concrete until the digging teeth 12 break through at ground level.
[0051] A curtain seal 42 extends down from the ends of the wear plate 6 so as to prevent the concrete from filling the vertical bores 2 . With such seals, the cement does not need to cure before the wear plate is displaced upwardly. In this example we would start at the bottom and pressure on until the desired height has been reached. Leave the ends in until material solidifies and then remove chains and seals etc if necessary and fill bores. Another solution to this problem however might be to pressurise the vertical bores by filling them with the second material. The wear plate would then need to be extended in length so that it seals to the edges of the vertical bores 2 .
[0052] A further solution may be to develop a moving seal (not illustrated) in the form of a belt running on pulleys or rollers.
[0053] In an alternative application, the tunnel providing the starting position may be dug at a lesser depth, and the teeth directed downwardly and backfilled with the second material from above, so as to excavate in a downward direction whilst backfilling with the second material.
[0054] In yet a further, alternate application, the second material used to backfill the excavated cavity is a commercially available granular material which attracts mineral oil deposits from the surrounding ground. After a period of time, the system can be used to excavate over the same plane/line and remove the granules. These granules can then be cleaned of oils/contaminants and reused for the same purpose. This then is a useful technique for extracting oil deposits from the ground.
[0055] In yet a further, alternate application, the second material used to backfill the excavated cavity is a granular material such as a fines concrete or sandy slurry. This then is a useful technique for the creation and development of underground aquifer's and water holding facilities that may be able to regulate ground water.
[0056] In yet a further alternative application, the second material as before mentioned in this filtering example can be used under roads and buildings that have high ground water or salinity issues. This system can be used to insert a line of course sand underneath the existing infrastructure so that the ground water will drain into the porous corridor of secondary material and drain to a collection point without the demolition of roads and other infrastructure.
[0057] It is considered that the means and method for creating subterranean structures according to the present Invention would be of particular those who wish to construct subterranean structures such as piers and retaining walls without having to excavate excess earth.
[0058] Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognised that departures can be made within the scope of the invention, which is not to be limited to the details described herein but is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus. | A system and method for creating a subterranean construction including an excavation means adapted to excavate a first material from a subterranean position, means for clearing this first material from the excavation site, and means for supplying the void left by the excavation with a supply of a second material that is dissimilar to the first material. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the manufacture of printed circuit boards having improved interlayer adhesion. More particularly, the present invention pertains to adhesiveless, flexible printed circuit boards having excellent thermal performance and useful for producing high-density circuits.
2. Description of the Related Art
Printed circuit boards are employed in a wide variety of applications. For example, they can be found inside radio and television sets, telephone systems, automobile dashboards and computers. They also play an important role in the operation of airborne avionics and guidance systems. Polyimide films are used in the production of circuit boards because of their excellent flex characteristics and good electrical properties. More particularly, it is common to attach a layer of a conductive metal foil to a surface of a polyimide film to provide a surface upon which a pattern of an electrical conductor can be provided. In such cases, it has been recognized in the art that any movement of the metal foil on the polymeric film could potentially impair the performance of the equipment incorporating the circuit board. To avoid this problem, it is necessary that the conductive metal layer be strongly adhered to the polymeric substrate to prevent any shifting of the metal layer on the film.
There have been various efforts in the art to improve the adhesion of metal foils to polymeric substrates in forming printed circuit boards while maintaining good thermal resistance and low cost of manufacture. U.S. Pat. No. 4,382,101 offers one proposed solution to this problem wherein a substrate is etched with a plasma etchant and then a metal is vapor deposited onto the etched surface of the substrate. This process requiring the vapor deposition of a metal directly onto an etched surface is very expensive. U.S. Pat. No. 4,615,763 provides a method of improving adhesion of a photosensitive material to a substrate by selectively etching resinous portions of a substrate comprising a resinous material and an inorganic particulate material. U.S. Pat. No. 4,639,285 teaches a process wherein a metal foil is attached to a surface of a synthetic resin substrate via an intermediate silicone-based adhesive layer after treating the substrate surface with a low temperature plasma. The low temperature plasma utilized is an organo-silicon compound with an inorganic gas, such as oxygen. U.S. Pat. No. 4,755,424 provides a polyimide film produced from a polyimide containing a dispersed inorganic powder. Particles of the inorganic powder protrude from the film surface to roughen the film. The film surfaces are then treated with a corona discharge treatment to alter the surface chemistry of the film. U.S. Pat. No. 4,863,808 teaches a polyimide film coated with a vapor deposited chromium layer, a vapor deposited copper layer, and followed by electroplating with copper. U.S. Pat. No. 5,861,192 provides a wet chemistry method with mechanical and projection grinding to increase the adhesion of a polyimide film surface.
The present invention provides an improved solution over those of the prior art. A process for forming printed circuit boards is provided wherein a polymeric film is coated onto at least one surface of an etched polymeric substrate followed by laminating a metal foil onto the coated film. The substrate surface may be etched with either a chemical or plasma etchant, and may comprise either the same or a different material than the polymeric film. The result is a circuit board with a substrate that exhibits high thermal resistance and excellent electrical insulating properties.
SUMMARY OF THE INVENTION
The invention provides a process for forming a printed circuit board composite comprising:
a) etching at least one of two opposite surfaces of a planar polymeric substrate;
b) attaching a polymeric film onto one or both etched surfaces of the polymeric substrate; and
c) laminating and attaching a metal foil onto the polymeric film.
The invention further provides a process for forming a printed circuit board comprising:
a) etching at least one of two opposite surfaces of a planar polymeric substrate;
b) attaching a polymeric film onto one or both etched surfaces of the polymeric substrate;
c) laminating and attaching a metal foil onto the polymeric film;
d) depositing a photoresist onto the metal foil;
e) exposing and developing the photoresist, thereby revealing underlying portions of the metal foil; and
f) removing the revealed underlying portions of the metal foil.
It is also within the scope of the invention to form multilayered printed circuit boards or composites by incorporating additional polymeric films or metal foil layers. A description of these embodiments is included herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention provides a printed circuit board support having improved interlayer adhesion, enhanced thermal stability and excellent electrical insulating properties as compared to the prior art.
The first step in the process of the invention is to etch at least one surface of two opposite surfaces of a suitable substrate with an appropriate etchant, thereby forming a first etched surface. Typical substrates are those suitable to be processed into a printed circuit or other microelectronic device. Preferred substrates for the present invention are polymeric substrates and non-exclusively include materials comprising polyester, polyimide, liquid crystal polymers and polymers reinforced with materials such as fiberglass, aramid (Kevlar), aramid paper (Thermount), polybenzoxolate paper or combinations thereof. Of these a polyimide substrate is the most preferred. Also suitable are semiconductor materials such as gallium arsenide (GaAs), silicon and compositions containing silicon such as crystalline silicon, polysilicon, amorphous silicon, epitaxial silicon, and silicon dioxide (SiO 2 ) and mixtures thereof. The preferred thickness of the substrate is of from about 5 μm to about 200 μm, more preferably from about 5 μm to about 50 μm.
Appropriate etchants are those which are capable of selectively removing portions of the substrate surface. Preferred etchants for the present invention non-exclusively include plasma etchants and concentrated aqueous etching solutions.
Preferred are aqueous alkaline solutions, non-exclusively include Group I or Group II hydroxides which include hydroxides of elements from Groups I or II of the periodic table, such as sodium hydroxide and potassium hydroxide. Ammonium hydroxide may also be used. The useful concentration of an aqueous etchant varies with the chemical composition of the substrate to be etched. Typically useful etchant concentrations range from about 5% to about 25% by weight of the etchant material, preferably from about 10% to about 20%. For example, one useful aqueous etchant is a potassium hydroxide solution having a concentration of from about 8% to about 12% of potassium hydroxide. Also suitable is a sodium hydroxide solution at a concentration of from about 8% to about 16% by weight of sodium hydroxide.
Any plasma etching technique which is suitable for etching polymer substrates may be used. This plasma etchant is a highly charged gas that bombards the film surface with positive and negative charged species causing impurities on the surface to degrade as well as ablating the film surface. These include halogen containing plasma etching materials and oxygen containing plasma etching materials. The preferred plasma etchant comprises a gaseous mixture of oxygen (O 2 ) and tetrafluoromethane (CF 4 ). Preferably the plasma etchant comprises at a mixture of oxygen plasma and tetrafluoromethane plasma comprising least about 3% of tetrafluoromethane, more preferably it comprises from about 3% to about 20% and still more preferably from about 7% to about 20% of tetrafluoromethane with the balance being oxygen. This minimum quantity of tetrafluoromethane is important to prevent any over etching of the substrate.
The etching step of the process of the present invention is accomplished by contacting the polymeric film with the aqueous base etchant or plasma etchant.
Etching is conducted by contacting the areas of the substrate to be etched with the etchant material. Plasma etching is conducted under conditions sufficient to remove at least about 0.45 μm from at least one surface of the substrate. Such procedures are well known in the art. In another embodiment of the invention, both surfaces of the substrate are etched, allowing additional layers to be added to the printed circuit board support of the invention having superior adhesion to the substrate.
When using an aqueous base etchant, the duration of the etching step is also determined based on the chemical composition of the substrate and is generally from about 10 seconds to about 4 minutes in length. For example, when using a KOH etchant, the etching time for a polyimide substrate is from about 20 seconds to about 3 minutes. Preferably the etching solution is maintained at a temperature of from about 40° C. to about 65° C. It has been found that neutralizing the surface with a dilute mineral acid to form a soluble salt and subsequently rinsing clean the surface with deionized water is desirable. Further, by altering the film residence time, the etch rate can be altered.
When etching is done by plasma etching, it may be performed in a plasma etching chamber as is well known in the art.
The next step is to apply a polymeric film onto one or both etched surfaces of the polymeric substrate. The polymeric film is preferably deposited onto the film as a liquid by coating, evaporation or vapor deposition to allow for control and uniformity of the polymer thickness. Preferred polymeric materials include polyimides, polyesters, polyester containing co-polymers, polyarylene ethers, liquid crystal polymers, polyphenylene ethers, amines, and combinations thereof.
Of these, polyimides are the most preferred. In another embodiment of the invention the polymeric film and the polymeric substrate comprise the same polymer.
Polyimides are preferred for the polymeric film because they have high electrical strengths, good insulating properties, a high softening point and are inert to many chemicals. Preferred are polyimides having a glass transition temperature (Tg) of from about 160° C. to about 320° C., with a glass transition temperature of from about 190° C. to about 270° C. are preferred. Preferably, the polymeric film will have a thickness of from about 2 μm to about 100 μm, more preferably from about 5 μm to about 50 μm.
The polymeric film may be applied to the polymeric substrate by coating a suitable solution onto the substrate and drying. The solution may be comprised of polymer precursors, a mixture of precursors and polymer or just polymer and an organic solvent. It is preferred that a single solvent be used in each solution. Useful solvents include acetone, methyl-ethyl ketone, N-methyl pyrrolidone, and mixtures thereof. The most preferred single solvent is N-methyl pyrrolidone. The polymer-solvent solution will typically have a viscosity ranging from about 5,000 to about 35,000 centipoise with a preferred viscosity in the range of 15,000 to 27,000 centipoise. The solution may comprise from about 10% by weight to about 60% by weight of polymer, more preferably from about 15% by weight to about 30% by weight of polymer with the remaining portion of the solution comprising one or more solvents. After application, the solvent is evaporated leaving a polymeric film on the substrate. Alternatively, a thin sheet of the polymer may be laminated under heat and pressure onto the substrate. In another embodiment, a molten mass of the polymer material may be extrusion coated onto the substrate.
The polymer film may also optionally incorporate a filler material. Preferred fillers non-exclusively include ceramics, boron nitride, silica, barium titanate, strontium titanate, barium strontium titanate, quartz, glass beads (micro-spheres), aluminum oxide, non-ceramic fillers and combinations thereof. If incorporated, a filler is preferably present in an amount of from about 5% to about 80% by weight of the film, more preferably from about 10% to about 50% by weight of the film.
Next, a metal foil is laminated to the substrate surface on which the polymer film has been formed. Lamination is preferably conducted by autoclave lamination, vacuum hydraulic pressing, non-vacuum hydraulic pressing or by hot roll lamination. Lamination may also be conducted using an ADARA™ press which comprises heating the metal foil by an amount sufficient to soften the polymeric film by flowing an electric current through the foil and attaching the polymeric film to the substrate. When using a vacuum press, lamination is preferably conducted at a minimum of about 275° C., for about 5-30 minutes. Preferably, the press is under a vacuum of at least 28 inches of mercury, and maintained at a pressure of about 150 psi.
Preferred metal foils for the printed circuit board support of the invention comprise copper, zinc, brass, chrome, nickel, aluminum, stainless steel, iron, gold, silver, titanium and combinations and alloys thereof. Most preferably, the metal foil comprises copper. Copper foils are preferably produced by electrodepositing copper from solution onto a rotating metal drum as is well known in the art. The metal foil preferably has a thickness of from about 3 μm to about 200 μm, more preferably from about 5 μm to about 50 μm. Alternatively, wrought copper foils may be used. However, the rolling process is effectively limited to producing foils no thinner than 18 microns.
The one or both sides of the metal foil may optionally be roughened, such as by micro-etching, by being electrolytically treated on the shiny side to form a roughened copper deposit, and or by being electrolytically treated on the matte side to include the deposition of micro-nodules of a metal or metal alloy on or in the surface. These nodules are preferably copper or a copper alloy, and increase adhesion to the polymer film. The surface microstructure of the foil may be measured by a profilometer, such as a Perthometer model M4P or S5P which is commercially available from Mahr Feinpruef Corporation of Cincinnati, Ohio. Topography measurements of the surface grain structure of peaks and valleys are made according to industry standard IPC-TM-650 Section 2.2.17 of the Institute for Interconnecting and Packaging Circuits of 2115 Sanders Road, Northbrook, Ill. 60062. The surface treatments are carried out to produce a surface structure having peaks and valleys which produce roughness parameters wherein the average roughness (Ra) ranges from about 1 to about 10 microns and the average peak to valley height (Rz) ranges from about 2 to about 10 microns.
The optional roughening of the shiny side of the foil is preferably carried out to produce a surface structure having peaks and valleys which produce with a roughness parameters wherein Ra ranges from about 1 to about 4 microns, preferably from about 2 to about 4 microns, and most preferably from about 3 to about 4 microns. The Rz value ranges from about 2 to about 4.5 microns, preferably from about 2.5 to about 4.5 microns, and more preferably from about 3 to about 4.5 microns.
The optional roughening of the matte side of the foil are preferably carried out to produce a surface structure having peaks and valleys which produce a roughness parameters wherein Ra ranges from about 4 to about 10 microns, preferably from about 4.5 to about 8 microns, and most preferably from about 5 to about 7.5 microns. The Rz value ranges from about 4 to about 10 microns, preferably from about 4 to about 9 microns, and more preferably from about 4 to about 7.5 microns.
An optional copper deposit on the shiny side of the foil will preferably produce a copper deposit of about 2 to about 4.5 μm thick to produce an average Ra value of 2 μm or greater. An optional nodule deposit on the matte side preferably will have an Ra value as made of about 4 to about 7.5 μm. The micro-nodules of metal or alloy will have a size of about 0.5 μm. Other metals may be deposited as micro nodules if desired, for example, zinc, indium, tin, cobalt, brass, bronze and the like. This process is more thoroughly described in U.S. Pat. No. 5,679,230.
In the preferred embodiment of the invention, the shiny surface preferably has a minimum peel strength of about 0.7 kg/linear cm., preferably from about 0.7 kg/linear cm, to about 1.6 kg/linear cm, more preferably from about 0.9 kg/linear cm to about 1.6 kg/linear cm. The matte surface preferably has a minimum peel strength of about 0.9 kg/linear cm and preferably from about 0.9 kg/linear cm to about 2 kg/linear cm, more preferably from about 1.1 kg/linear cm to about 2 kg/linear cm. Peel strength is measured according to industry standard IPC-TM-650 Section 2.4.8 Revision C.
In another embodiment of the invention, prior to lamination of the metal foil onto the polymeric film, a thin metal layer may optionally be electrolytically deposited onto either side of the metal foil. After lamination of the metal foil to the polymeric film, a thin metal layer may optionally be deposited onto the foil surface opposite the polymeric film by coating, sputtering, evaporation or by lamination onto the foil layer. Preferably the optional thin metal layer is a thin film and comprises a material selected such as nickel, tin, palladium platinum, chromium, titanium, molybdenum or alloys thereof. Most preferably the thin metal layer comprises nickel or tin. The thin metal layer preferably has a thickness of from about 0.01 μm to about 10 μm, more preferably from about 0.2 μm to about 3 μm.
The resulting laminate will have a peel strength that varies widely based on the thickness of the polymeric layers and the amount of substrate surface removal. For example, in order to obtain a laminate having an adequate peel strength of at least 4 lbs/inch, it is necessary to remove at least 0.45 μm from the substrate surface.
After the metal foil has been laminated onto the coated substrate, the next step is to selectively etch away portions of the metal foil or metal foil and optional thin metal layer, forming an etched pattern of circuit lines and spaces in the foil, or in the foil and optional thin metal layer. This etched pattern is formed by well known photolithographic techniques using a photoresist composition. First, a photoresist is deposited onto the metal foil or optional thin metal layer. The photoresist composition may be positive working or negative working and is generally commercially available. Suitable positive working photoresists are well known in the art and may comprise an O-quinone diazide radiation sensitizer. The O-quinone diazide sensitizers include the o-quinone-4-or-5-sulfonyl-diazides disclosed in U.S. Pat. Nos. 2,797,213; 3,106,465; 3,148.983; 3,130,047; 3,201,329; 3,785,825; and 3,802,885. When O-quinone diazides are used preferred binding resins include a water insoluble, aqueous alkaline soluble or swellable binding resin, which is preferably a novolak. Suitable positive photodielectric resins may be obtained commercially, for example, under the trade name of A7-P4620 from Clariant Corporation of Somerville, N.J. as well as Shipley I-line photoresist. Negative photoresists are also widely commercially available.
The photoresist is then imagewise exposed to actinic radiation such as light in the visible, ultraviolet or infrared regions of the spectrum through a mask, or scanned by an electron beam, ion or neutron beam or X-ray radiation. Actinic radiation may be in the form of incoherent light or coherent light, for example, light from a laser. The photoresist is then imagewise developed using a suitable solvent, such as an aqueous alkaline solution, thereby revealing underlying portions of the metal foil or optional thin metal layer.
Subsequently, the revealed underlying portions of the metal foil or metal foil and optional thin metal layer are removed through well known etching techniques, such as acid or alkaline etching, while not removing the portions underlying the remaining photoresist. Suitable etchants non-exclusively include acidic solutions, such as cupric chloride (preferable for etching of nickel) or nitric acid (preferable for etching of tin). Also preferred are ferric chloride or sulfuric peroxide (hydrogen peroxide with sulfuric acid). Suitable etchants also non-exclusively include alkaline solutions, such as ammonium chloride/ammonium hydroxide.
If the optional thin metal layer is included, this step will reveal the portions of the metal foil underlying the etched off portions of the thin metal layer. This patterned thin metal layer is then useful as a high quality etch mask for etching the metal foil. After the thin metal layer is etched, the next step is to remove the revealed underlying portions of the metal foil by etching while not removing the portions of the metal foil underlying the non-removed portions of the optional thin metal layer, revealing portions of the polymeric film underlying the etched metal foil.
If the optional thin metal layer is not included, the metal foil is directly etched to revealing the portions of the polymeric film underlying the etched off portions of the metal foil. The laminate may then be rinsed and dried. The result is a printed circuit board having excellent resolution and uniformity, good thermal resistance and excellent interlayer adhesion.
After the circuit lines and spaces are etched through the metal foil, the remaining photoresist can optionally be removed either by stripping with a suitable solvent or by ashing by well known ashing techniques. The photoresist may also be removed after etching the optional thin metal layer, but prior to etching the metal foil.
In another preferred embodiment of the invention, the above processes may be repeated on an opposite side of the substrate. In this embodiment, two opposite surfaces of the substrate are etched by the techniques described above, and a layer of a polymeric film material may be coated or laminated onto each etched surface, followed by lamination of a metal foil layer onto each polymeric film. Each metal foil layer may then be patterned and etched by the techniques described above, including by using an optional thin metal layer.
The following non-limiting examples serve to illustrate the invention:
EXAMPLE 1
A polyimide film substrate is plasma treated with a highly charged plasma etchant gas mixture of oxygen (O 2 ) and tetrafluroromethane (CF 4 ), the gas mixture containing 7% CF 4 . The plasma etchant bombards the film surface with positively and negatively charged species causing impurities on the film surface to degrade and ablating the film surface. This etching step removes approximately 0.7 μm of material from the surface of the film. Subsequently, the etched surface is coated with a continuous layer of polyimide to achieve a layer thickness of 8 μm. The coated substrate and a copper foil layer are then laminated together in a vacuum press at about 275° C., for about 30 minutes, under a vacuum of at least 28 inches of mercury, and maintained at a pressure of about 150 psi. The resulting laminate has a peel strength of about 4 lbs/inch.
EXAMPLE 2
A polyimide substrate is plasma treated under similar conditions as in Example 1 using an etchant consisting of a gas mixture of oxygen (O 2 ) and tetrafluoro methane (CF 4 ), containing 7% CF 4 . However, the etching step is conducted to remove approximately 0.475 μm of material from the surface of the film. After coating the etched surface with a polyimide film and laminating the coated substrate together with a copper foil as in Example 1, the resulting laminate exhibits a peel strength of about 4.5 lbs/inch.
EXAMPLE 3 (COMPARATIVE)
Example 1 is repeated except using an etchant having only 3% CF 4 and rather than limiting the etching step to remove approximately 0.7 μm of material from the surface of the film, the etching step is continued for about 15 minutes. This results in an overetched laminate having reduced peel strength. The peel strength of the laminate after fifteen minutes is only about 0.5 lbs/inch.
EXAMPLE 4
Example 1 is repeated, but rather than coating an etched substrate with only an 8 μm layer of polyimide, a 12 μm coating of polyimide is applied. This resulting laminate exhibits peel strength of about 7 lbs/inch.
EXAMPLE 5
Example 1 is repeated, but rather than coating an etched substrate with only an 8 μm layer of polyimide, a 30 μm coating of polyimide is applied. This resulting laminate exhibits peel strength of about 9 lbs/inch.
EXAMPLE 6
A 25 μm polyimide substrate is etched on both sides using similar etching conditions as in Example 1. Each etched surface is coated with a 12 μm layer of a polyimide, followed by lamination of a copper foil onto each polyimide layer on the opposite sides of the substrate under conditions similar to Example 1. The resulting laminate is a polyimide dielectric of about 50 μm, having a peel strength in excess of 7 lbs/inch.
EXAMPLE 7
A 25 μm polyimide substrate is chemically etched by running the film through solution of 12% by weight NaOH in water at 47° C. followed by a 5% sulfuric acid neutralization and a final deionized water rinse. The substrate is subsequently coated with 5 μm of polyimide. A 9 μm copper foil is then laminated to the coated substrate under conditions similar to Example 1. The resulting laminate has a peel strength of 6 lbs/inch.
EXAMPLE 8 (COMPARATIVE)
An unetched 25 μm polyimide substrate is coated with 5 μm of polyimide. A 9 μm copper foil laminated to the coated substrate under conditions similar to Example 1. The result is a laminate having a peel strength of only about 0.5 lbs/inch.
While the present invention has been particularly shown and described with reference to preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above and all equivalents thereto. | The invention relates to the manufacture of printed circuit boards having improved interlayer adhesion. More particularly, the present invention pertains to adhesiveless printed circuit boards having excellent thermal performance and useful for producing high-density circuits. A metal foil is laminated to an etched surface of a polyimide substrate having a polyimide film thereon. Etching the substrate surface allows for strong adhesion of a pure polyimide film to the substrate. | 7 |
BACKGROUND OF THE INVENTION
Compressed gasses have been utilized for transferring fluids for many decades. Steam under high pressure has been injected into inaccessible oil deposits under the earth to force it to the surface. For nearly five decades and perhaps before that compressed helium or nitrogen has been injected into the fuel tanks of aerospace vehicles to displace the propellants from the tanks into the injector nozzles. Bubbling air in ponds for circulating and aerating (oxygenating) the water is a procedure well over a century old. A similar process of injecting compressed air through an inclined tube is used in ships' drinking water tanks, fish tanks and aquariums today for identical purposes. The gas is supplied by a gas pump or bubble pump. U.S. Pat. No. 5,203,910 issued to Larry Areaux and Brian Klenoski on Apr. 20, 1993, utilizes the bubble pump method for inducing a flow of molten metal in a conduit for its recirculation in a furnace.
This particular invention pertains to a bubble-operated pump for removing or diluting dross from the surface of a bath of molten metal. In steel strip galvanizing, such a molten metal bath surface is contained within an inert gas filled snout that encloses the steel strip being introduced into the bath.
Steel utilized in the automotive, construction and appliance industries and the like is formed in very thin strips (0.015 to 0.060 inch thick), which is then passed through a molten bath of either aluminum (aluminizing), zinc (galvanizing) or aluminum/zinc (galvalume). The strip width usually ranges from 30 to 70 inches. To avoid the formation of oxides on the strip's surface that are detrimental to the coating quality, the strip is delivered to the molten bath from a nitrogen/hydrogen-filled furnace through a tubular housing (snout), also filled with the same gas (see FIG. 1 ). Because of the extremely large dimensions of the equipment required and in spite of efforts to prevent air leaks into the furnace, small air leaks occur, generating ferrous oxides (Fe 2 O 3 , FeO, etc.).
When the steel strip enters the bath, a chemical process occurs in which the aluminum or zinc in the bath reacts with the iron oxides to form dross, aluminum oxides (Al 2 O 3 ) and/or zinc oxides (ZnO). In other words,
2Al+Fe.sub.2 O.sub.3 =Al.sub.2 O.sub.3 +2Fe
3Zn+Fe.sub.2 O.sub.3 =3ZnO+2Fe
The free iron released settles to the bottom of the molten metal pot. On the other hand, because of their slightly lower density to the molten metal, the alumina (Al 2 O 3 ) and zinc oxide (ZnO) remain in suspension or float to the surface. The dross accumulated in the area enclosed by the snout is a very hard ceramic and usually contains large particulate that adheres to the steel strip being processed creating a defective coating, poor appearance and high rejection rates.
The present approach to remove such dross, because of its inaccessibility, is to: 1) stop the line, 2) vent the furnace and snout areas of their inert gas, 3) lift the snout, and 4) clean the area by raking the dross off the bath's surface which is obviously a very time-consuming, expensive and production-affecting procedure.
A conventional motorized pump having mechanical parts exposed to molten metal and forcing hard ceramic-based dross through its propellers and bearings has an expensive maintenance problem coupled with a short life.
SUMMARY OF THE INVENTION
I have experimented with a different approach for removing the dross by pumping it through a snorkel-shaped conduit having its inlet placed inside the tubular snout.
The broad purpose of the present invention is to provide a reliable and inexpensive pump for removing dross from the surface of a molten metal bath enclosed in a delivery snout.
Another object of the invention is to provide a bubble-type pump having no moving parts for removing dross from an enclosed snout in a molten metal bath.
Still another object of the invention is to provide a bubble-type pump having no moving parts for delivering molten metal into the dross area in an enclosed gas-filled snout to dilute the dross concentration.
In the preferred embodiment of the invention, both the dross dilution pump and the dross removal pump comprise a tubular conduit having an inlet side for receiving molten metal and an outlet side for discharging the metal. A source of an inert gas such as nitrogen (or argon) is connected in the outlet side of the conduit. As the nitrogen bubbles upwards toward the surface, it creates a suction effect in the inlet side of the conduit generating a flow of metal in the same direction.
When the pump is used for dross removal, the inlet side is disposed with its entrance adjacent the dross level of the bath inside the gas-filled snout, the outlet side being disposed outside the snout. When the pump is used as a dross diluent, the inlet side is disposed beneath the surface of the bath outside the snout, with its outlet side disposed closely adjacent the dross.
Still further objects and advantages of the invention will be apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views and in which:
FIG. 1 is a schematic sectional view through a molten metal bath showing a dross removal pump and a dross diluting pump illustrating the invention;
FIG. 2 is an enlarged sectional view as seen along lines 2--2 of FIG. 1;
FIG. 3 is an enlarged sectional view as seen along lines 3--3 of FIG. 1, illustrating the dross removal pump location;
FIG. 4 is a more detailed sectional view of the dross removal pump;
FIG. 5 is a view as seen as seen along lines 5--5 of FIG. 4;
FIG. 6 is an enlarged view as seen from the top of FIG. 5;
FIG. 7 is a view of the dross diluting pump;
FIG. 8 is a view as seen from the right side of FIG. 7;
FIG. 9 illustrates an inert gas delivery system schematic for a continuous gas flow arrangement; and
FIG. 10 illustrates an inert gas delivery system schematic for a pulsating gas flow arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 illustrates a conventional heated metal pot 10, which for illustrative purposes, contains a bath of molten aluminum 12. The bath has a top surface 14, usually referred to as the molten metal line. A continuous moving strip of low carbon steel 16 is introduced into the bath from a furnace (not shown) in the conventional manner as illustrated in FIG. 3. The strip passes around a sink roll 17 and tensor rolls 17A, while submerged in the bath, so that the surface of the strip picks up an aluminum coating.
Strip 16 is delivered to the bath through a conventional tubular snout housing 18. The interior of the housing contains an inert gas such as nitrogen or a mix of nitrogen and hydrogen which, as is well known to those skilled in the art, is useful in preventing the steel strip from oxidizing. Oxidation damages the coating being applied.
The lower exit opening 20 of the snout housing is disposed 6-12 inches below top surface 14 of the bath in order to assure a sealed area for the inert gas filling the furnace and the snout. The steel strip enters the bath through lower opening 20 of the snout, submerged into the metal by the rotating rolls as shown in FIG. 3. The strip emerges from the bath and passes on to air knives (not shown) which remove excess coating metal, and then passes to its next destination.
The chemical reaction occurring between the steel strip, the steel strip oxides and the aluminum bath creates a dross layer 21 that accumulates at surface 14 inside the snout housing. An inert gas bubble-operated dross removal pump means 22 removes dross from layer 21. A second inert gas-operated bubble pump means 24 delivers molten aluminum to the dross layer inside the snout housing to dilute the dross.
Referring to FIGS. 3-5, the dross removal pump has a generally U-shaped tubular conduit 26. The tubular conduit can be manufactured from different materials, depending on the particular molten metal bath in which it is being utilized. In a zinc galvanizing bath, tubular conduit 26 can be manufactured from stainless steel material or AT-103 or AT-103A, a metallic super alloy material available from ALPHATECH, INC. of Trenton, Mich., specially formulated for resistance to zinc at temperatures up to 1400° F. In galvalume (aluminum and zinc) or aluminum, conduit 26 can be manufactured from any ceramic material resistant to these molten metals, or RBSN-AL25, a ceramic material also available from ALPHATECH, that has proved to be extremely resistant to molten aluminum attack at temperatures up to 1600° F. and capable of withstanding up to 5000 thermal shocks from air to molten aluminum at 1480° F.
The diameter of conduit 26 depends upon the amount of dross flow expected to be removed by the pump. For most existing galvanizing and aluminizing lines, a tube diameter of 2.5 to 3 inches should be sufficient.
The conduit has an upper inlet opening 28 formed at an angle of 45°-60° with respect to the vertical leg of the conduit and supported in dross layer 21 of the bath. Conduit 26 has an outlet opening 30, also formed at an angle of 45°-60° with respect to the longitudinal axis of the vertical leg of the conduit as shown in FIG. 5. Opening 30 is disposed 2 to 6 inches below the dross layer 21. Inlet opening 28 and outlet opening 30 face upwardly.
A pump body 32, in this particular application for molten aluminum, is manufactured from a graphite material with its upper portion housed in a ceramic outer layer 34 to prevent air burning of the graphite in the portion of the housing above the metal line. Pump body 32 is connected to a suitable external support 35.
A source of inert gas 36 such as nitrogen, delivers the gas through a vertical conduit 38 located inside pump body 32 to an opening 42 in conduit 26. Opening 42 is preferably placed 14 to 16 inches below outlet opening 30. In applications where severe dross conditions exist requiring additional suction forces, the depth of opening 42 can be increased to obtain the desired results.
The gas can be delivered either in a continuous or an intermittent form. In either case, the gas emerges from opening 42, and forms a series of spaced bubbles 44 because of surface tension. The bubbles rise in the molten aluminum. The rising bubbles entrap sections of molten aluminum between them and carry them upwardly in the direction of arrow 46.
By applying an intermittent flow of gas as shown in FIG. 10, the utilization of the gas can be optimized by adjusting the frequency of the bubbles' formation and expansion rate to match the particular application. The rising bubbles induce a flow of molten metal towards outlet opening 30, generating a suction at inlet opening 28 which causes the dross located on the surface of the bath to move in the direction of arrow 48 into the inlet opening. A flow is created into conduit 26, thereby scavenging the dross from inside snout housing 18 to a location outside the housing where it can be skimmed off or removed by conventional means.
As can be seen from the description, the pump apparatus involves no moving parts exposed to the molten metal.
Referring to FIGS. 7 and 8, dross dilution pump means 24 is similar in structure and operation to the dross removal pump, comprising also a U-shaped conduit 50 having a pair of vertical arms 52 and 54 terminating with lower inlet opening 56 and upper outlet opening 58. The two openings are formed at an angle of about 45° with respect to the longitudinal axis of their respective legs. Inlet opening 56 is disposed 12 to 14 inches below the level of the bath while outlet opening 58 is disposed adjacent the dross layer inside snout housing 18.
Conduit 50 is formed of ceramic for use in an aluminum or galvalume bath and has a diameter of about 2.5 to 3 inches. Inlet opening 56 is disposed about 14 to 16 inches below outlet opening 58 and located outside housing 18. Conduit 50 is supported by a graphite or ceramic housing 60 having, in the case of graphite, a ceramic exterior shield 62 mounted on a suitable frame means 64, so that both the inlet and outlet openings face upwardly. The entire assembly is attached to the exterior face of the snout housing to assure its relative vertical and horizontal positions.
A source of nitrogen 66 (or any other inert gas such as argon or helium) is connected to a conduit passage 68 located in the pump housing which passes downwardly and then across a horizontal conduit leg 70 to an opening 72 in the lower part of arm 52, beneath outlet opening 58. The nitrogen is delivered in either a continuous or an intermittent form (depending on the degree of flow control desired) to form a series of spaced bubbles 74 which rise toward outlet opening 58 in the direction of arrow 76. The rising bubbles induce a flow of relatively uncontaminated molten aluminum 12 through inlet opening 56 in the direction of arrows 78. Thus, a substantially continuous flow of aluminum is delivered inside the snout housing, diluting the dross and thereby minimizing not only the amount but the particulate size of the dross formed around moving strip of steel 16. In addition, the uncontaminated aluminum flow assists the dross removal pump in scavenging the dross from inside the snout housing.
FIG. 9 shows a means for modulating the pressure of the inert gas being received from source 36, a compressed gas tank. The gas may be either gaseous or liquid nitrogen, argon or helium. A coarse pressure regulator 80 is mounted on the tank for regulating a pressure down from a range of 3000/2000 p.s.i. to 200± p.s.i. Regulator 82 is in conduit 84 which delivers the gas from source 36 to the pump. Regulator 82 is a fine adjusting pressure regulator for regulating pressure down from 200±100 to 30 p.s.i. ±10 p.s.i.
Pressure gauge 86 is connected in the conduit for measuring the pressure and reads from 0 to 100 p.s.i.
Gas flow meter 88 is connected in the conduit 84 for controlling the gas flow from 0 to 100 cfh. Higher gas flows may be required for larger conduit 26 diameter.
FIG. 10 illustrates a control system similar to FIG. 9, but in which a solenoid valve 90 is mounted in the conduit with an ON/OFF timing device 92 for providing an intermittent charge of gas and which can be regulated between 0 to 2 seconds between charges.
For illustrative purposes almost 25,000 pounds per hour of dross may be removed from the pot using 40 standard cubic feet per hour of nitrogen at 15 to 25 p.s.i. | A bubble-actuated pump is used for removing dross from the surface of a bath of molten metal. A modification of the pump is employed for delivering molten metal to the dross for diluting it. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The priority benefit under 35 USC 119(e) of U.S. Provisional Patent Application Ser. No. 60/970,419 filed Sep. 6, 2007, is claimed.
BACKGROUND OF THE DISCLOSURE
[0002] 1. Field of the Disclosure
[0003] The disclosure relates generally to methods for preventing and/or extinguishing fires and, more specifically, to methods for applying water-laden polymer to a surface to prevent and/or extinguish fires.
[0004] 2. Brief Description of Related Technology
[0005] Water is commonly used to extinguish fires and to prevent the spread thereof to nearby structures. Water has several beneficial effects when applied to a fire, including heat removal and oxygen deprivation. When water is directed at a structure adjacent a fire to prevent its spread thereto, the fire must provide enough heat to evaporate the water on (or in the materials of) the adjacent structure before the adjacent structure can reach its combustion or ignition temperature.
[0006] One disadvantage to using water to prevent a fire from spreading to a nearby structure is that most of the water directed at the structure does not soak into the structure to provide fire protection, but rather tends to run off the structure to the ground. Consequently, a significant quantity of water is wasted. Another disadvantage is that any water that does soak into the structure provides only limited protection against the fire because most structures only absorb a limited amount of water, and that limited amount of absorbed water quickly evaporates. Therefore, significant manpower must be expended to continuously reapply water on nearby structures to provide them with continuing fire protection.
[0007] A disadvantage to using water to extinguish fires is that a considerable amount of the water does not directly fight or extinguish the fire because of the run-off problem described above. Another disadvantage to using water in extinguishing fires is that the water sprayed directly on the fire evaporates at an upper level of the fire, with the result that significantly less water than is applied is able to penetrate sufficiently to extinguish the base of the fire.
[0008] There are a number of US patents that address the use of particulate superabsorbent dry polymers for use in fire prevention and fire extinguishing, including: von Blücher U.S. Pat. No. 4,978,460; von Blücher U.S. Pat. No. 5,190,110; and Pascente U.S. Pat. No. 5,849,210. An understanding of the properties of these polymers and how they can be used to improve fire prevention and fire extinguishing is useful.
[0009] Superabsorbent polymers were developed from of a generic class of water-soluble synthetic polymers that are primarily used in water clarification. These synthetic polymers have a tremendous affinity for water and they dissolve in water, forming ‘fish nets’ of entangled linear molecules, with molecular weights in the millions, that act to agglomerate and precipitate unwanted solids from water. These water-soluble polymers are generally available in dry, particulate form and are dissolved in water over time to produce a functional solution. Time of dissolution is not generally a serious concern. A solution is produced as each successive molecular layer from the surface of the polymer particle is dissolved. Thus, the size of the particle determines only the time for dissolution. While this process may seem obvious, understanding the sequential, surface-in nature of polymer dissolution is a fundamental factor in effective use of particulate superabsorbent polymers in fire fighting.
[0010] Superabsorbent polymers are produced by adding to a reaction mixture of the linear polymers described above, cross-linking agents which form two- and/or three-dimensional bonds between the linear molecules. The effect of this cross-linking is to immobilize the linear molecules. Their affinity for water is not reduced, but now water must be absorbed within the cross-linked structure. The particulate structure does not change in shape as it absorbs water, but simply swells, retaining its relative dimensional configuration. The ultimate size of the hydrated superabsorbent polymer particle is a function of its size in the dry state. The rate of water absorption of the surface superabsorbent particle is the same as for the surface of the linear particle mentioned above, but because the surface layer does not dissolve and move away from the particle's surface, the rate of water penetration of the cross-linked polymer is much slower than the rate of dissolution of linear polymer. As a result, the rate of water uptake by the superabsorbent polymer is affected by particle size impeded by the cross-linked structure.
[0011] Superabsorbent polymers in the fire-fighting world are referred to as “water enhancers.” The polymer itself does virtually nothing to prevent or extinguish combustion, but rather immobilizes water that would otherwise either evaporate or run off the combustion surface, in either case becoming ineffective in preventing or extinguishing a fire. It is at this point that the rate at which a superabsorbent polymer takes up water, and the structural sizes of polymer particles after uptake of water, become critical in firefighting effectiveness. In immobilizing water, it is critical that the superabsorbent polymer take up water quickly and uniformly so that a homogenous, cohesive gel is formed. In order to provide the greatest combustion surface protection it is essential that the gel produced utilizes the available water, provides an absolutely uniform coating (like paint) on the surface to which it is applied, and that such uniformity of gel builds a structure that allows development of a coating of sufficient viscosity to, at one end of the viscosity spectrum, flow around and coat needles, twigs and branches on trees, and when concentrated, to adhere in thickness to vertical surfaces for structure protection. Gels that contain discrete, water-swollen particles that interrupt uniform film formation are not optimally functional in fire fighting and do not form films that will provide uniform coatings on vertical surfaces.
[0012] A critical issue in producing a truly film-forming coating is definition and control of the original particle size of the dry superabsorbent polymer particle before hydration. Only by such control can the optimal uniform cohesive gel structure be produced. Without control of particle size, discontinuous partial coatings are produced that leave areas of thin or no coating, the swollen gel agglomerates having no film of gel protecting the area between the agglomerates. The swollen gel agglomerates are essentially surrounded by plain water that simply runs off or evaporates, making it impossible to build a gel structure that will film, or adhere to a vertical, or even sloped surface. Individual swollen gel particles simply fall off. Even on horizontal surfaces, where the swollen gel particles don't fall off, the discontinuous, film-free areas between swollen gel particles are analogous to weak links in the fire-fighting chain, the film-free area being essentially unprotected from combustion.
[0013] The teachings of the three US patents identified above do not recognize the significant parameter of particle size in production of a cohesive coating. von Blücher '460 specifically describes the water-added product as having a bulk viscosity “only slightly higher than water,” meaning that the larger particles of swollen superabsorbent polymer (exemplified as having a dry particle size of 100 to 300 microns) would, by definition, be essentially floating in, or surrounded by water. This would not produce a homogenous, cohesive coating to significantly prevent or extinguish combustion, and the comparative test results in '460 bear this out. Further, a composition containing water and swollen, superabsorbent particles does not adhere to vertical surfaces. There is nothing inherently sticky about swollen superabsorbent particles, particularly when they are surrounded by water and they move easily from place to place. The modest increase in time of combustion protection detailed in '460 is undoubtedly due to the water contained in the swollen gel particles providing some minimal additional water in the vicinity of combustion but this does not compare with the protection provided by a continuous, cohesive gel coating.
[0014] The teachings of '460 are concerned with preventing lumping of particles of superabsorbent polymer that “was impossible to grind” (column 4, line 15). Superabsorbent polymers can be finely ground utilizing the proper equipment. Finely ground superabsorbent polymer does not require silicic acid or other additives to accelerate its swelling or water take up, as it takes up water just as quickly in its pristine, finely ground state. The teachings of ‘460’ relating to encapsulating superabsorbent polymer particles in a water soluble release agent (in a high percentage in an example), are unnecessary to assure lump-free water absorption.
[0015] von Blücher '110 teaches directly away from the production of a uniform gel film, specifically teaching that the viscosity of the admixture of superabsorbent polymer and water should have a viscosity of less than 100 cps. Such a viscosity is consistent with swollen lumps of gel surrounded by essentially water-viscosity water. This, not surprisingly, produces a mixture as easily handled as water but it does not produce a uniform coating on any surface to prevent surface combustion. The best way to prevent the low viscosity water from running off and being wasted is to thicken it with finely ground superabsorbent polymer and have all the superabsorbent product utilized in producing a uniform gel having a viscosity of more than 100 cps. The firefighter does not want water running anywhere, he wants it to stay where it is directed. Immobilizing all the water within an homogenous, cohesive gel structure accomplishes that objective.
[0016] Pascente '210 teaches substantially the same firefighting ability of water-swollen gel as the earlier '460 and '110, and does not address the particle size of the dry superabsorbent polymer. Although it is taught that superabsorbent polymer particles should have a particle size “preferably less than 100 μm in diameter” (column 4, line 17), the stated reason for this limitation is so the gel produced can be extruded through the nozzle of a fire extinguisher. This teaching recognizes that swollen gel particles are of such significant size that they need to be deformed to pass through the relatively large openings of a fire nozzle. Further, there is recognition of the non-uniformity and non-film-forming nature of the water/superabsorbent polymer mixture beginning in column 6, line 26, where it's stated that “higher viscosity gels can be adhesively secured to vertical or sloped surfaces to hold the gel in place.” A non-homogenous mixture of swollen polymer particles in water will not adhere by itself to a vertical surface, hence the need for an “adhesive.” Polymer particle sizing loosely described as less than 100 μm (100 microns) does not meet criteria for producing an homogenous, cohesive uniform coating that will adhere by itself to a vertical surface. A commercial dry superabsorbent firefighting product available in the United States demonstrates the deficiency of large particle sizes for forming coherent, homogenous coatings for preventing or extinguishing fire.
SUMMARY OF THE DISCLOSURE
[0017] This disclosure demonstrates the significant improvement in fire prevention and/or extinguishing of a coherent, aqueous gel produced from dry, superabsorbent polymer particles ground to substantially 20 microns or less in diameter when compared to firefighting gels produced from larger particles that do not produce coherent coatings. Preferably, the mean particle diameter of the dry polymer is less than 20 microns, highly preferably 10 microns or less, and most preferably less than 10 microns. If the superabsorbent polymer particles of less than 20 microns are dispersed directly in water, they will produce anything from a smooth, film-forming coating at low concentration to a thick gel that will build a self-adherent coating at higher concentrations up a half-inch thick or more on a vertical surface without the need for any adhesive. Both the low concentration uniform film and higher concentration thick gel coating provide far better fire protection that an admixture of the same respective concentrations produced from coarser superabsorbent polymer particles. The coherent gels significantly retard combustion and, further, the coherent gel can be sprayed onto vertical and other burning surfaces to extinguish fire. The superabsorbent polymers of this disclosure preferably produce gels that hold more than 50% of the water in the water-additive mixture after swelling.
DETAILED DESCRIPTION
[0018] The preferred superabsorbent polymer of this disclosure is preferably a dry, cross-linked, water-soluble polymer, most preferably produced from at least one of the following monomers.
[0019] The polymer is preferably a polymer of hydrophilic monomers, such as acrylamide, acrylic acid derivatives, maleic acid anhydride, itaconic acid, 2-hydroxyl ethyl acrylate, polyethylene glycol dimethacrylate, allyl methacrylate, tetraethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 2-tert-butyl amino ethyl methacrylate; dimethylaminopropyl methacrylamide, 2-dimethylaminoethyl methacrylate, hydroxypropyl acrylate, trimethylolpropane trimethacrylate, 2-acrylamido-2 methylpropanesulfonic acid derivatives, and other hydrophilic monomers. Preferably, the polymer is a co-polymer of acrylamide and acrylic acid derivatives and, more preferably, a terpolymer of an acrylate salt, acrylamide, and a 2-acrylamido-2-methylpropanesulfonic acid (AMPS) salt. The salts may generally be any monovalent salt, but preferably are sodium, potassium, or ammonium salts.
[0020] Many such dry polymers are commercially available and are routinely used in diapers, and as soil amendments in agriculture.
[0021] Because the degree of hardness of the water, in other words the amount of divalent cations in the water, affects the degree of swelling of the polymer particles, a component may also be introduced to counteract water hardness. A suitable monomer to counteract water hardness in this application is 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or a salt or other derivative thereof. The polymer is preferably a terpolymer of an acrylate salt, acrylamide, and an AMPS salt. The amount of AMPS included in the dry polymer may be varied depending on the hardness of the water in the particular region of use. Nevertheless, the polymer is effective without inclusion of a chemical to counteract water hardness, particularly in geographical regions that do not have hard water. Depending on the hardness of water, higher concentrations of polymer (e.g., up 2 wt. % of dry polymer in waters of very high hardness) may prove useful in forming the coherent gel for use in the invention.
[0022] To illustrate the invention, a relatively finely ground, commercially available superabsorbent polymer (AQUASORB 3005-KC made by SNF, Inc.) was further commercially ground on a jet mill manufactured by Netzsch Inc., without difficulty, to a particle size of 97% less than 20 microns/100% less than 30 microns and a mean value of 9.2 microns.
[0023] After grinding, the ground polymer of mean value 9.2 microns was mechanically dispersed in water to determine the quality of gel produced at concentrations from 0.3 wt. % to 1.0 wt. % dry polymer solids. No discrete particles in the gels could be detected at any concentration. The coherent gels produced coatings from a thin, almost imperceptible layer (at 0.3 wt. % dry polymer solids) when applied to a smooth surface, through a flowable gel that produced coherent coatings on sloped or vertical surfaces of ⅛ to 3/16 of an inch thick (at 0.5 wt. % dry polymer solids), to a homogenous coherent gel that would adhere to a vertical surface in thicknesses of up to ¾ inch (at 1.0 wt. % dry polymer solids).
[0024] For comparative purposes, the same relatively finely-ground, commercially available superabsorbent polymer described above was commercially ground to a coarser specification (99.0% minus 150 microns, 97% minus 75 microns, 91.1% minus 38 microns, 83.8% minus 25 microns). This grind did not produce a coherent coating at 0.5 wt. % dry polymer solids, and the viscosity of the 0.5 wt. % dispersion was barely higher than water viscosity. Particles were visually apparent in the 0.5 wt. % dispersion. This clearly demonstrates the need for fine particle size in order to produce functional coherent coatings.
[0025] One undesirable and market-limiting characteristic of the finely ground 9.2 micron mean particle size superabsorbent polymer was severe dusting on handling. The dusting problem would probably have made using the finely ground polymer impractical. However, dusting can be controlled by the addition of an anti-dusting agent such as fumed silica, preferably in an amount of 3 wt. % to 7 wt. % based on the weight of dry ground polymer. The addition of fumed silica (CAB-O-SIL EH-5) did not inhibit the rapid formation of gel when the polymer was mechanically dispersed in water, nor did it have any deleterious effect on the quality or firefighting ability of the gel at any concentration. The various concentrations of the finely-ground, silica-treated superabsorbent polymer of this disclosure were compared to the rate of gel formation, visual quality, film forming ability, coherence, adherence to a vertical surface and firefighting performance of the commercially available product mentioned above.
[0026] Comparing the polymer product of this disclosure with that of the commercially available superabsorbent firefighting polymer (PHOS-CHEK AQUAGEL K) at concentrations in water of 0.3 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %, at all concentrations the finely ground polymer product of this disclosure dispersed to a coherent homogenous gel virtually instantly. This coherent gel coated and adhered to vertical surfaces in increasing thickness as the concentration was increased. In all cases the commercially available product produced granular dispersions that did not produce a coherent coating nor adhere to vertical surfaces. These comparisons were made by dipping wooden boards vertically into each product at the four concentrations and then removing the boards and observing coating characteristics. Comparative viscosities of the product of this disclosure and the commercially available firefighting gel are given in Table 1:
[0000]
TABLE 1
Viscosities In cps; Brookfield LVT Viscometer
[TDS is Total Dissolved Solids; Hardness as Calcium Carbonate]
Product of disclosure
Commercially available
(5 wt. % silica-treated)
product
(concentrations in water)
(concentrations in water)
Water-type
0.3 wt. %
0.35 wt. %
0.4 wt. %
0.5 wt. %
0.3 wt. %
0.5 wt. %
TDS 270 ppm
490 cps
6400 cps
20 cps
600 cps
(no
hardness)
TDS 270 ppm
900 cps
1950 cps
4700 cps
600 cps
(hardness
110 ppm)
TDS 260 ppm
3650 cps
350 cps
(hardness
220 ppm)
[0027] The viscosity comparisons show clearly the differences in characteristics of the two products in water. The Brookfield viscometer's rotating sensing element responds normally to the increasing coherent concentrations of the product of this disclosure. True viscosity measurements are only scientifically meaningful in homogenous substrates and, in the case of the commercially available product, the sensing element is essentially just spinning in the water between the swollen gel particles, with the swollen gel particles bouncing off the element and providing some frictional resistance.
[0028] Viscosities are given for various waters. The 270 ppm TDS/110 ppm total hardness water represents an average naturally-occurring water. The viscosities at additional concentrations are shown to demonstrate how easily a desired viscosity can be achieved with gel produced from the product of this disclosure. Gel viscosities in the range of 800 cps to 1400 cps would generally be used in aerial firefighting, depending on the type of trees and/or underbrush (fuels) to be coated and the thickness of coherent gel coating desired.
[0029] The same dipped sample boards described above, standing vertically, were then exposed to a propane impingement flame. The comparative times for the impinging flame to burn through the dipped coatings and ignite the boards are given in Table 2:
[0000]
TABLE 2
Product of this
disclosure
Commercially available
Aqueous Gel
(time to ignite
product
Concentration
the board)
(time to ignite the board)
wt. %
seconds
seconds
0.3%
22
3
0.5%
31
4
0.75%
51
4
1.0%
82
4
[0030] The homogenous coherent gel coatings of this disclosure give spectacular fire protection.
[0031] When a uniform coating is not formed by the superabsorbent polymer in water (as is the case with the commercially available product), there is virtually no improvement in the fire-protecting properties of the gel over plain water. This is not really surprising since there is only a water-wet surface between the swollen gel particles. The impinging flame simply evaporates that surface water and ignites the wood. The water-wet surface between the swollen gel particles of the commercially available product is the weak link in the firefighting chain.
[0032] Interestingly, if the 0.75 wt. % gels of both products as described in Table 2 are applied onto a horizontal wood surface to ⅜ th of an inch thickness, a completely different result is obtained. The gel product of the present disclosure burns through in 77 seconds; the commercially available gel product burns through in 64 seconds, which tends to confirm results of Pascente '210, where gel was spread on the horizontal surfaces of burning charcoal (column 6, lines 17-20). But the only way the '210 results could be simulated was through the careful packing of the swollen gel particles to form the ⅜ inch layer, and carefully keeping the board horizontal so the particles didn't slide off. The product of the present disclosure can be sprayed, or dropped from aircraft, to form a coating that will adhere, but the product described in '210 can't, since it won't adhere to a horizontal surface, or to itself. The suggestion in '210, that an adhesive be first applied, say to a forest to induce adhesion of the gel, is impractical at best. The key is forming a coherent gel coating that will adhere by itself.
[0033] To simulate aerial drop applications for fighting forest fires from either fixed-wing aircraft or helicopters, a series of wooden dowels of ⅛ th inch, 3/16 th inch, and ¼ inch in diameter were mounted vertically, spaced ⅛ th inch to 3/16 th inch apart. The dowels ranged in length from 10 inches to 12 inches.
[0034] The first test was to spray 0.5 wt. % concentrations of the product of this disclosure, and the commercially available product, on the dry dowels from above to simulate aerial application and evaluate the products as fire retardants (i.e., where aerial drops are made ahead of the fire front, as a fire break, with the intent to stop the fire at that point). The coherent gel of this disclosure was easily sprayed from above, but the gel dispersion of the commercially available product plugged the spray nozzle and finally had to be poured over the vertical dowels in order to get acceptable distribution. After application of the two gels, visual observation showed the coherent gel of this disclosure to have thoroughly coated each vertical dowel with a uniform film. The gel made from the commercial product wetted the dowels, with a few gel particles jammed between the dowels, but there was no functional coating. Fifteen minutes after each of these respective applications, propane flame was applied near the base of the dowels, circling the dowel grouping continuously with the flame from a fixed distance. The dowel grouping, to which the commercially available gel was applied, was totally engulfed in self-sustaining flame in 21 seconds. The dowel grouping, to which the gel of this disclosure was applied, did not sustain combustion at any point on any individual dowel for 65 seconds, and the grouping was totally engulfed in self-sustaining flame only after 118 seconds. Spraying plain water, and repeating this test, resulted in self-sustaining combustion in 18 seconds. Application of the gel, that is subject of this disclosure, clearly gave superior fire retarding performance when compared to gel from the commercially available product.
[0035] The final test was to confirm the fire extinguishing ability of gels vs. water. A dowel grouping was ignited and combustion allowed to proceed until flames towered about 18 inches above the dowels. Water was sprayed from eighteen inches above the flame top in a fixed time period without significant effect, the flames momentarily dying down and then surging until all the dowels were burned to their bases. Repeating the test, the same volume of 0.5 wt. % gel made from the subject of this disclosure was sprayed in the same time period from the same distance above the approximately 18 inch high flames. Flame was completely extinguished.
[0036] It was not possible to test gel made from the commercially available product under the same conditions. Gel made from the commercially available product could not be sprayed because the gel lumps caused plugging. When the same volume of gel made from the commercially available product was poured over the same flame height, part of the dowel grouping was briefly extinguished but shortly thereafter the still burning dowels re-ignited those that had been extinguished, and all the dowels burned to their bases.
[0037] The coherent gel coating, the subject of this disclosure, quickly extinguished this simulation of a ‘crowning’ forest fire, and did not allow re-ignition. (A ‘crowning’ fire is where the flame front spreads quickly from tree-top to tree-top.) Non-homogenous gel, made from commercially available product, was comparatively deficient in extinguishing the simulated crowning fire.
[0038] The coherent gel coating, the subject of this disclosure, is clearly superior in preventing and extinguishing fire when compared to a non-uniform gel coating. | A method for applying water-laden polymer to a surface to prevent and/or extinguish a fire, the method comprising the steps of dispersing a dry, ground, superabsorbent polymer comprising particles of 20 microns or less in diameter to water in an amount sufficient to form a coherent polymer gel, and directing the coherent polymer gel onto a surface to prevent and/or extinguish a fire. | 0 |
RELATED APPLICATION
This application claims the benefit of priority to U.S. Provisional Application No. 61/909,724 filed on Nov. 27, 2013. The disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to improving the condensation resistance of a metal roof penetration in accordance with principles of the present disclosure.
BACKGROUND
With the current design of metal roof curbs the sidewall configuration of the curb tends to have a thermal short circuit into the inside area of the building. This is caused by the continuance of the metal through the sidewall section from the outside to the inside. This can cause the inside surface of the metal curb to remain at a temperature below the dew point temperature that can lead to condensation forming on the inside surface, causing what appears to water leaks within the building. The current method of addressing this problem is to trim and retain the surrounding roof insulation which does not present a thermal-break in the curb wall. This method is labor intensive and the foam retaining rod used to secure the surrounding roof insulation can become dislodged. Moreover, the use of the retaining rod, in this fashion, often times does not result in a pleasing visual experience for the finished installation.
For the foregoing reasons, there is a need to eliminate the loss of heat from the interior surfaces so the surfaces remain at a temperature above the dew point so that condensation does not occur on any surface.
For the foregoing reasons, there is a need for an inexpensive alternative to trimming off of the excess roof insulation.
For the foregoing reasons, there is a need for an alternative to the trimming off of the roof insulation that provides a more aesthetically appealing appearance upon completion of the installation of the insulation.
SUMMARY
Curbs are constructed on metal roofs around skylights and mechanical equipment such as heating or air condition units, to divert rain precipitation around the unit. The curbs are usually constructed as a rectangle whose side walls are parallel to corresponding sides of the roof.
In an exemplary embodiment a system is disclosed to provide a thermal break to eliminate a thermal short circuit in the system to maintain a minimum surface temperature above the dew point for the conditions present, to provide a system to retain the surrounding roof insulation that is cost effective and provides for the above mentioned thermal break; to provide a cleaner, more aesthetically pleasing appearance to the surrounding roof insulation, to utilize an insulating retaining rod configured to secure the surrounding roof insulation within the configuration of components that eliminates the possible inadvertent release of the retaining rod and the insulation as presently experienced with existing systems. In addition, the disclosed embodiment provides an easier to install application of the foam retaining rod over current designs as well as a design that can be used with any metal roof curbs used to support mechanical units including HVAC units, fans, as well as other applications of skylights and roof hatches.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawings in which like numerals represent like components. The contents of this summary section are provided only as a simplified introduction to the disclosure, and are not intended to be used to limit the scope of the appended claims.
The contents of this summary section are provided only as a simplified introduction to the disclosure, and are not intended to be used to limit the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cutaway view of an embodiment of a roof curb sidewall section;
FIG. 2 illustrates a cutaway view of an embodiment of a roof curb sidewall section detailing an insulation termination method;
FIG. 3 illustrates a cutaway view of an embodiment of a roof curb sidewall section detailing an alternative insulation termination method;
FIG. 4 illustrates an embodiment of the assembly of the thermal break and the side rail; and
FIG. 5 illustrates a cutaway view of an embodiment of the insulating assembly detailing the disclosed technology.
DETAILED DESCRIPTION
The following description is of various exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the present disclosure in any way. Rather, the following description is intended to provide a convenient illustration for implementing various embodiments including the best mode. As will become apparent, various changes may be made in the function and arrangement of the elements described in these embodiments without departing from the scope of the appended claims.
Metal buildings with metal roofs have become popular for commercial, industrial and warehousing uses. These buildings often require roof openings for skylights, fans, air conditioning units and the like. The installation of such equipment requires a roof curb for support.
Traditionally, roof curbs have been designed specifically and custom made to provide a relatively horizontal mounting structure for a particular rooftop appliance given the shape and pitch of a particular roof. Designing and building these traditional roof curbs, often formed from a singular piece of metal to uniquely accommodate a particular roof pitch, has been a laborious and time consuming task for roof curb manufacturers and rooftop appliance installers.
Turning now to FIG. 1 which reveals a curb section 20 with reference to the interior and exterior of the curb and building structure. The roof curb sidewall section 24 is positioned past the cut edge 25 of the roof structure 26 . The roof insulation 28 wraps beneath the curb sidewall section 24 and is held in position by a clip element 30 at the curb sidewall section 24 . A layer of insulation 32 is also disposed against the interior surface 34 of the roof curb sidewall section 24 . A skylight 36 is positioned over the curb section to allow access of daylight and to prevent intrusion of moisture. This particular design, when environmental conditions are aligned will support the formation of condensation on metal surfaces proximate C 1 . When the condensation forms at this point many occupants of the building will characterize this as a leaking roof and seek roof repairs when in reality with the design identified under FIG. 1 little can be done to prevent the formation of condensation other than to prevent the interior temperature and humidity from reaching the point where condensation forms.
Turning now to FIG. 2 which reveals an alternative configuration which also suffers from the deficiency that condensation may form at C 2 . This design is similar in most respects as regards the metal roof curb 20 and skylight 36 detailed in FIG. 1 , but instead employs an insulation retainer 40 to hold the roof insulation in position.
FIG. 3 illustrates a current method of trimming and retaining the surrounding roof insulation 28 which is quite labor intensive. In addition, this particular methodology results in an appearance that is less than desirable as roof insulation can fall out of the slot 42 that retains a flexible insulating rod 44 and the end of the insulation 46 . This configuration is also deficient in that it does not provide a thermal break and condensation can form at C 3 .
Turning now to FIG. 4 which details an exemplary embodiment of an insulating assembly 50 comprising a side rail 52 inter-engaged with a thermal-break 54 segment for preventing the formation of condensation on roof curb installations. The thermal break element 54 is preferably comprised of an engineered plastic such as polyvinyl chloride (PVC), that is interlocked with a side rail 52 preferably comprised of an extruded aluminum. The thermal break element 54 , just as the name suggests, is an insulator and serves to limit the transfer of heat away from the interior to the exterior of the structure.
The thermal-break 54 horizontal segment 60 includes a slot 62 that engages and interlocks with an upwardly extending flange 64 on the first segment 66 of the side rail 52 . In addition, the second segment 68 of the side rail 52 includes a hard stop 70 that abuts the first terminating edge 72 of the thermal-break 54 . The vertical wall 74 of the thermal break 54 terminate at an upper edge 76 and in conjunction with the oppositely disposed upwardly extending second segment 68 of the side rail 52 forms a pocket 80 for positioning of a longitudinally extending insulating rod 84 (seen in FIG. 5 ). The insulating rod 84 serves to limit the transfer of heat between the interior space of the structure and the ambient environment and in conjunction with the thermal-break 54 can substantially reduce the potential for the formation of condensation. The second segment 68 of the side rail 52 terminates at a bend 86 of greater than 90 degrees and traverses into the third segment 88 of the side rail. When installed, the third segment 88 will be penetrated by self-tapping screws that secure the insulating assembly 50 to the skylight or other feature installed on the curb 90 . The third segment 88 is bent downwardly at a corner 92 to form a fourth segment 94 . The fourth segment 94 at approximately mid-span includes a plurality of through holes 98 . The through holes 98 are used for passing mounting hardware 100 through the fourth segment 94 and to anchor the faced insulation 104 in place as best seen in FIG. 5
The fourth segment 94 extends downwardly to a termination point 108 and turns outwardly at approximately a 90 degree angle to form a fifth segment 112 . The fifth segment 112 , like all of the prior segments, may be of any desired length to accommodate the desired configuration of the structure being secured to the curb. The fifth segment 112 extends to a termination point 116 . A sixth segment 118 extends downwardly from the termination point 116 at a preferred angle of approximately 75 degrees; however, other angles of departure are also appropriate depending upon the configuration of the structure secured to the roof. The sixth segment 118 further includes a plurality of longitudinally displaced through holes 120 . The through holes allow passage of securement hardware 124 to attach the entire side rail 52 and the entire insulating assembly 50 to the ribs 130 of, for example, standing seam metal roof panels 132 .
FIG. 5 illustrates an embodiment of the insulating assembly 50 in position beneath a domed skylight 140 . In application of the insulating assembly, first an appropriately sized opening is cut into the roof panels 132 of the structure. For example, in a standing seam roof the roof panel 132 will be cut on the interior side of the seams. Once the opening in the roof structure has been created, installation of the insulating assembly 50 can commence with the passage of securement hardware 124 through the longitudinally displaced through holes 120 in the sixth segment 118 of the insulating assembly 50 . This securement hardware 124 serves to not only secure the insulating assembly to the roof panels 132 but also to secure a flexible weather-seal 144 in position beneath the fifth and sixth segments 112 , 118 to prevent intrusion of water into the structure. Multiple units of the securement hardware 124 secure the sixth segment 118 along the entire longitudinal length of the sixth segment 118 . Passing the hardware through the sixth segment 118 and into the rib 130 of the roof panel 132 facilitates a watertight seal and rigidly secures the insulating assembly to the roof structure. The fifth segment 112 preferably rests atop the panel ridge 148 and the weather-seal 144 thereby providing further support for the insulating assembly 50 .
Extending upwardly from the fifth segment 112 is the fourth vertical segment 94 through which attachment hardware 100 is passed to anchor the faced insulation 104 in position when installed. The faced insulation 104 must be adequately anchored in position or with the passage of time and minor building movements it will loosen and drop from its position thereby reducing the thermal efficiency of the dome installation. Prior to the installation of the domed skylight 140 an insulating rod 84 is positioned into the pocket 80 . The diameter of the insulating rod 84 is slightly greater than the width of the longitudinally extending pocket 80 thereby creating a compression fit for the insulating rod 84 . Once the domed skylight 140 is installed, the top of the insulating rod 84 will interfere with the skylight flange 160 and will compress slightly forming an airtight seal that will prevent the intrusion of outside air.
Next, the installer of the domed skylight 140 , or other roof feature, passes a threaded fastener 156 through the flange 160 of the dome 140 and into the third segment 88 . Positioned beneath the flange 160 of the dome 140 is a weather seal 164 that prevents the intrusion of air, and water, into the interior of the building. The passage of the threaded fasteners 156 will secure the weather seal 164 into position and prevent the intrusion of ambient air and moisture.
As previously noted, during installation of the domed skylight 140 , or other roof component, as seen in FIG. 5 , an edge of the faced insulation 104 is wrapped upward for engagement with the securement hardware 100 through the fourth segment 94 . The insulation 104 is then wrapped tightly around the edge 180 of the roof panel that has been cut for the skylight opening and continues to run beneath the remaining roof panels to enhance the thermal efficiency of the structure.
Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings. | Disclosed is a system for improving the condensation resistance of metal roof penetrations. When environmental conditions are right, the curbs associated with metal roof penetrations can experience condensation on metal parts for which there is no thermal break. The disclosed system provides a mechanism to implement a thermal break to prevent the formation of condensation. | 4 |
CONTINUITY
[0001] This application is a non-provisional application of provisional patent application No. 61,708,660 filed on Oct. 2, 2012, and priority is claimed thereto.
FIELD OF THE PRESENT INVENTION
[0002] The present invention relates to fitness equipment, and more specifically, fitness equipment employed to practice martial arts, boxing, and other physical impact sports through the use of a form of punching bag. The present invention aims to detect improvement of the user's muscles in terms of physical force applied to the punching bag over time.
BACKGROUND OF THE PRESENT INVENTION
[0003] While there are many workout methods, mannerisms, and routines, each is generally tailored to exercise specific muscles or groups of muscles of the body. Weight lifting such as barbells and bench presses tone the upper body, and quantitative changes of an individual's muscle strength can be determined over time by the difference in the amount of weight the individual can lift or press under similar conditions. Similarly, exercise using a modern treadmill, elliptical machine, or stationary bicycle conventionally provides the user with feedback on his or her performance via a digital readout display which can be used to track progress such as distance, speed, and calories burned, over time. Additionally, progress made when performing freestanding, manual exercises such as push-ups, pull-ups, an sit-ups can be determined by how many ‘sets’ or ‘reps’ an individual is capable of performing in one sitting. For example, if an individual performs 10 push-ups one week, and the next, the individual is capable of performing 15 push-ups, improvement can be determined.
[0004] However, many other forms of exercise are not equipped with such direct methods of feedback capable of indicating to the individual the extent of his or her progress over time. One exercise method commonly employed that is not easily quantitated is exercises employing a conventional punching bag. Counters exist to measure the number of times that small, elevated, punching-dongles are struck, yet none of them properly measure the force of impact at the impact site. Additionally, other methods such as manual counting by a fitness trainer exist that may measure the duration of time an individual is capable of consistently striking a punching bag.
[0005] Unfortunately, there is no effective means of measuring the force of impact on multiple impact sites within a conventional punching bag frame. Similarly, when punching or kicking a heavy bag, there really is no effective way to know what progress the user has made between workouts. Thus, there is a need for a device that can accurately capture the quantitative, statistical data of a workout that employs a conventional punching bag, so that the workout and prior workouts performed by an individual through the use of a punching bag may be generated and recorded for the individual with ease.
[0006] U.S. Pat. No. 7,858,729 for “Automated Striking and Blocking Trainer with Quantitative Feedback” by Sullivan et al., published on Dec. 28, 2010, shows an automated striking and blocking trainer that gives quantitative feedback. Unlike the proposed invention, Sullivan et al.'s device consists of a frame, a striking body, and a punching bag. Similar to the proposed invention, as seen in claim 7 in column 7, lines 39-46, Sullivan et al.'s device keeps track of total number of strikes, average time between strikes, average force of the strikes, a maximum force recorded of all strikes, punch count, punch speed, punch accuracy, punch power, and trend data over the duration of a workout. Sullivan et al.'s device, like the proposed invention, also uses accelerometers to measure impact. However, unlike the present invention, Sullivan et al. is not configured to be adaptable to any conventional punching bag frame.
[0007] U.S. Pat. No. 7,308,818 for “Impact-Sensing and Measurement Systems, Methods for Using Same, and Related Business Methods” by Considine et al., issued on Dec. 18, 2007, employs at least one impact-sensor module, a controller module, and a feedback device. Each impact-sensor module can include one or more accelerometers, dynamometers, magnetic-based sensors or other sensors. The impact-sensor modules are attachable to locations on a target such as a dummy, punching bag, etc. Although the impact-sensor modules are not attached to a wrap, as in the proposed invention, the sensors can be attached to a punching bag or other object in a way that will accomplish the same aims as the proposed invention. In addition, as with the proposed invention, Considine et al.'s invention provides detailed impact data such as average force, maximum force, number of impacts, etc.
[0008] U.S. Pat. No. 6,925,851 for “Method and System for Detecting and Displaying the Impact of a Blow” by Reinbold et al., issued on Aug. 9, 2005, shows a system of detecting and displaying force data relating to impacts received on “an item of athletic equipment,” possibly a boxing glove. Each item of athletic equipment has “a force sensor, logic and a wireless transmitter therein, a receiver adapted to receive signals from each of the transmitters, and a processor for formatting the data for display.” In column 12, lines 59-62, the application states, “Examples of athletic equipment in which the sensor may be placed are heavy hitting bags, speed bags, training gloves, bag gloves, punching mitts, hitting targets and shield and body protection . . . ” Reinbold et al.'s invention also calculates factors such as maximum force used. Although Reinbold et al.'s invention does not specifically place sensors on an impact wrap, the patent does mention placing the sensors on items that the impact wrap with its sensors would also be placed on. However, unlike the present invention, Reinbold et al. is not specifically designed to be securely mounted solely to a punching bag such that it is seamlessly integrated into the workout device. Additionally, Reinbold et al. is not designed to progressively track the progress of a user over time.
[0009] U.S. Pub. No. 2011/0172060 for “Interactive Systems and Methods for Reactive Martial Arts Fitness Training,” published on Jul. 14, 2011 by Morales et al., shows an “impact target” (numbered “110” throughout the publication) with one or more impact sensors that measure workout performance data. As stated in claim 1 , the “martial arts fitness machine” comprises an “impact target having one or more sensors disposed to collect user input with respect to hit direction, impact g-force, hit timing, and hit location on the impact target”. Although claim 1 also refers to a “base pad” that the proposed invention does not have, there are similarities to the proposed invention. However, the present invention differs in that it is designed to adapt to any existing conventional punching bag, and is designed to be more versatile than the invention of this publication.
[0010] U.S. Pub. 2010/0307222 for “Measuring Instrument for the Detection and Evaluation of an Impact” by Oberleitner, published on Dec. 9, 2010, shows a measuring device for detecting and evaluating an impact. Oberleitner uses an “impact pad” with at least one force sensor to evaluate an impact, punch, etc., and at least one acceleration sensor. Both sensors are connected to an evaluation unit for processing the detected values. Although the impact pad is described as “in particular for a coaching mitt or hand mitt,” it does appear to have similarities to the present invention, however it differs in that it does not adapt to the progress of the user, nor supply the user with feedback regarding duration, strength, or progress of a workout.
[0011] U.S. Pub. No. 2006/0258515 for “Interactive Virtual Personal Trainer” by Kang et al., published on Nov. 16, 2006, shows a virtual trainer system and method of using such a system. Although Kang et al.'s invention is not a wrap with sensors attached, there are similarities to the proposed invention. In section [0013], Kang et al. is described as having “a plurality of impact sensors [that] are associated on the impact receiving body . . . ” Section [0015] states, “The impact receiving body is typically hollow and formed from a resilient foam material.” Thus Kang et al. employs sensors embedded within a foam material, which sounds similar to the proposed invention. In addition, Kang et al.'s impact sensor is “capable of measuring data related to an impact force applied to the impact sensor.” However, unlike the present invention, Kang et al. does not employ a similar layout, nor are the strikes registered in a historical fashion to measure progression or regression over time.
[0012] U.S. Pub. No. 2003/0216228 for “Systems and Methods of Sports Training Using Specific Biofeedback” by Rast, published on Nov. 20, 2003, shows an apparatus for providing biofeedback sports training As stated in section [ 0347 ], Rast's invention can be use a mesh or a grid of detectors. This is especially useful for golf training, since location of a hit ball can be detected. The concept of a grid of impact sensors seems to bear similarities to the present invention, however the present invention differs in that it is not tailored to the intensity of a punching bag workout, and is not designed to hand the stress of numerous impacts across a conventional punching bag.
SUMMARY OF THE PRESENT INVENTION
[0013] The present invention is a force measurement and timing system placed within a wrap, configured to be affixed to a conventional punching bag via a conventional strap or Velcro TM appendage, wrapping around a punching bag, regardless of its size, such that it remains removable, yet firmly mounted to the punching bag. Embedded within the wrap, preferably composed of fabric such as neoprene and/or plastic, there exists a multitude of impact zones designed to capture data pertaining to each impact provided by a user during the course of his or her workout routine.
[0014] Each impact zone is preferably equipped with an independent accelerometer, capable of gathering data pertaining to each instance the specific impact zone is struck by the limbs of a user. Data gathered includes, but is not limited to, the number of strikes per exercise session, the hardest strike (the most forceful strike in terms of pounds of force), the average force per strike, and the estimated calories burned by the user throughout the workout.
[0015] The present invention is equipped with an onboard computer housed within the digital display that contains conventional memory. The memory is used to maintain the data acquired from previous workouts, in order to compare current workout data to prior workout data. In this manner, the digital display is capable of informing the user whether progress has been made. A battery, housed within the digital display, powers the digital display, as well as the accelerometers housed within each impact zone. Power is conveyed to each impact zone via a series of wires. Data is conveyed to the digital display via the series of wires as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 exhibits the present invention from the front, detached from a punching bag.
[0017] FIG. 2 shows the present invention mounted to a conventional punching bag from the front.
[0018] FIG. 3 displays the present invention as mounted to a conventional punching bag from the rear.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] The present invention is a system for measuring the force, duration, and frequency of strikes applied to a conventional punching bag during the workout of a user in order to determine progression or regression in strength and stamina in the muscles of the user. The present invention primarily consists of a wrap ( 10 ), preferably composed of a fabric or plastic polymer such as neoprene, and designed to encompass a conventional punching bag securely. The wrap ( 10 ) is preferably held in place on the punching bag via Velcro or a similar temporary bonding agent.
[0020] The present invention is secured to the punching bag via a system of belts. As seen in FIG. 1 , the present invention is equipped with a first wrap belt ( 30 ) and a second wrap belt ( 40 ). The first wrap belt ( 30 ) is located on the top ( 80 ) of the present invention, and the second wrap belt ( 40 ) is located on the bottom ( 90 ) of the present invention. The first wrap belt ( 30 ) and the second wrap belt ( 40 ) are configured to tighten and secure the present invention around a conventional punching bag, regardless of its size. While these are the preferred locations of the first wrap belt ( 30 ) and the second wrap belt ( 40 ), it is envisioned that the user may mount the wrap ( 10 ) of the present invention to any point on the punching bag as the preference of the user determines. The height of the user may be a factor in the placement of the present invention on the punching bag.
[0021] As denoted in FIG. 3 , the present invention is preferably equipped with a vertical seam ( 60 ) preferably composed of Velcro™, or another conventional means of mounting, designed to secure the first wrap belt ( 30 ) and the second wrap belt ( 40 ), and therefore, the wrap itself, in any position on the punching bag. This provides further customization as to the placement of the wrap ( 10 ) of the present invention by the user.
[0022] The present invention is equipped with an assortment of impact zones ( 20 ) consisting of sensors, which are marked on the present invention, and preferably highlighted with an accent color, as seen in FIG. 1 and FIG. 2 . Each sensor found within each impact zone ( 20 ) is equipped with at least one accelerometer configured to measure the force of an impact when struck. Additionally, each accelerometer located within each impact zone ( 20 ) is configured to recognize when the impact zone ( 20 ) is struck under any force, and register the strike as a hit. It is to be understood that the accelerometers employed in the sensors of the impact zones ( 20 ) of the present invention are conventional.
[0023] The present invention is equipped with a digital display ( 50 ). The digital display ( 50 ) functions similarly to a basic computer, which is able to store usage data, workout data, and workout history data in conventional memory. The digital display ( 50 ) is secured with a wrap-around belt ( 70 ), allowing for placement of the digital display ( 50 ) anywhere on the present invention. In this manner, the user may opt to place the digital display ( 50 ) of the present invention on the top ( 80 ) or the bottom ( 90 ) of the wrap ( 10 ) of the present invention, or indeed, any position in between. The digital display ( 50 ) is configured to display statistics pertaining to the workout of a user in real-time, as well as to denote progression or regression in strength over time. The digital display ( 50 ) preferably houses a memory buffer system on a silicone computer chip conventionally known as a ‘system-on-a-chip.’ A basic processor may be employed to power the calculation of force to time, store the data, and to determine what to display on the digital display ( 50 ).
[0024] Preferably, the digital display ( 50 ) actively shows the following information: time remaining in a workout session (as configured by the user), current round of the workout session (as configured by the user), impact count, maximum impact force for the duration of the workout, the average impact force for the duration of the workout, and calories burned during the workout. It is envisioned that the memory inside of the digital display ( 50 ) is capable of maintaining a workout history in order to compare the statistics from previous workouts to the current workout, in order to determine the progression or regression of the muscles and stamina of a user.
[0025] In the preferred embodiment of the present invention, the digital display ( 50 ) is preferably configured to be housed within a plastic or metallic casing. The digital display ( 50 ) is preferably equipped with at least one speaker ( 120 ). A first button ( 130 ), a second button ( 140 ), a third button ( 150 ) and a fourth button ( 160 ) are preferably placed along the exterior of the casing of the digital display ( 50 ). The first button ( 130 ) preferably functions as the start/stop button for an integrated timer. The second button ( 140 ) preferably functions as a set/next button, capable of providing multiple functions to the user, including, but not limited to setting goals, a timer, and cycling through the various screens displayed on the digital display ( 50 ). The third button ( 150 ) and the fourth button ( 160 ) are to preferably be used in conjunction with the second button ( 140 ) in order to set various goals, timers, the time, or other functions. The third button ( 150 ) is preferably designated as a ‘negative’ button, designed to cycle downward through numerals. The fourth button ( 160 ) is preferably designated as a ‘positive’ button, designed to cycle upward through numerals. Although these are the preferred uses for the
[0026] Data collected from the accelerometers within the impact zones ( 20 ) of the present invention is preferably conveyed to the digital display ( 50 ) via a series of conventional wires. The wires are preferably housed within the wrap ( 10 ) of the present invention, such that they do not infringe on the workout of a user. Similarly, it is envisioned that power is supplied to the impact zones ( 20 ) via the series of conventional wires, in order to power the accelerometers held within the sensors of the impact zones ( 20 ). In the preferred embodiment of the present invention, the digital display ( 50 ) and the impact zones ( 20 ) of the present invention are powered by DC power, preferably found in a battery housed within the digital display. However, in alternate embodiments of the present invention, it is envisioned that alternate power sources, such as DC solar power or conventional, 120V AC power may be employed and adapted through the use of a conventional AC adaptor which is preferably plugged into the digital display ( 50 ). The preferred embodiment of the present invention includes 9 impact zones ( 20 ), as shown in FIG. 1 ; however, it is envisioned that, in alternate embodiments of the present invention, additional sensors may be added. Similarly, in other embodiments of the present invention, fewer than nine sensors could be incorporated into the wrap ( 10 ) of the present invention to achieve the same effect. In instantiations where there are fewer than nine sensors, it is envisioned that the length and/or width of the present invention would be smaller. Embodiments with fewer sensors would be ideal for punching bags that are smaller than the conventional long-standing punching bag.
[0027] While the present invention is designed to be lightweight and easily adaptable to any conventional punching bag, it is envisioned that, in alternate embodiments of the present invention, the wrap ( 10 ) of the present invention may include additional padding in order to protect the series of wires relaying the data to the digital display ( 50 ) and powering the sensors. It is to be understood that the impact zones ( 20 ) of the present invention are to be constructed of impact resistant materials, such that they do not crack or break under the force of multiple strikes by the limb of a user, increasing the durability of the present invention.
[0028] Alternate embodiments of the present invention may feature an upgraded computer system housed within the digital display ( 50 ) of the present invention. An upgraded computer system would be capable of managing data from a variety of users, rather than a single user. Similarly, and upgraded computer system could be capable of wirelessly exporting workout data to a conventional PC or other internet connected device. For example, after a workout, the upgraded computer system housed within the digital display ( 50 ) of this embodiment of the present invention may export the workout data to a Microsoft Excel spreadsheet immediately after each workout, in order to facilitate the tracking of the progress of the user over long periods of time. It is envisioned that the user could program the digital display ( 50 ) to relay workout data to a wirelessly connected printer, and physically print out the workout data after each workout automatically according to directions imposed by the user of the present invention.
[0029] Similarly, in other embodiments of the present invention, a digital display ( 50 ) configured with an upgraded computer system may be capable of advanced functions such as wireless music integration, which could play music at a tempo consistent with the strikes of the user upon the wrap ( 10 ) during his or her workout routine.
[0030] Additionally, in another alternate embodiment of the present invention, sequentially flashing illuminated impact zones ( 20 ), instructing the user as to which impact zones ( 20 ) to strike and in what order, helping to perfect potential fighting strategies or routines. Similarly, an upgraded computer system, housed within the digital display ( 50 ) of the present invention could be configured to weigh the strength of the user's punches, commonly directed at the impact zones ( 20 ) near the top ( 80 ) of the wrap ( 10 ), against the strength of the user's kicks, commonly directed to strike at the impact zones ( 20 ) found near the bottom ( 80 ) of the wrap ( 10 ). In this manner, a comparison of strength can be achieved.
[0031] Alternately, the digital display ( 50 ) of the present invention could be configured to display the heart rate of a user, and track the heart rate over time. The heart rate of a user would preferably be gathered via a conventional body sensor, which may wirelessly convey the heart rate of the user to the digital display ( 50 ).
[0032] Additionally, in alternate embodiments of the present invention, the data displayed on the digital display ( 50 ) may be configured to be ported to a digital device screen instead of, or in addition to, displaying on the digital display ( 50 ). The digital device could be a smartphone, digital audio player, tablet, or other similar small digital device with memory. The data could be configured to be displayed on a smartphone by interfacing the smartphone with the digital display ( 50 ) and system-on-a-chip via a USB interface cable, Bluetooth, or similar means of conventional connection. The present invention may then employ the memory of the smart phone in order to store the data attained by the sensors in the impact zones ( 20 ).
[0033] It should be understood that the present invention is not limited to form-fitting solely to conventionally sized ‘punching bags,’ but that it may be adapted to fit a wide assortment of strike/impact bags designed for a workout, including but not limited to ‘heavy bag,’ ‘kick boxing bag,’ ‘Mixed Martial Arts (MMA) bag,’ etc. Therefore, it should be understood that any mention of a punching bag in this application is meant to include any and all derivatives or variants on an impact bag designed to be struck by an individual during a workout. It should be understood that the first belt wrap ( 30 ) and the second belt wrap ( 40 ) may not be needed if the wrap ( 10 ) of the present invention is configured to act as a sleeve that could cover the impact bag.
[0034] It is to be understood that the present invention is not solely limited to the invention as described in the embodiments above, but further comprises any and all embodiments within the score of this application. | A device system designed to quantitatively measure the impact forces experienced by a conventional punching bag when hit by the fist or foot of an individual during a workout. The device is configured to wrap around the punching bag, such that the device bears the impact of each hit. Accelerometers and a sophisticated impact detection system are employed in order to detect the intensity or force of each hit. Additionally, a small on-board computer compares the force of current hits to those of past hits, and determines the level of improvement or regression over time. The on-board computer displays impact and other data on a digital display viewable to the individual performing the workout. | 0 |
RELATED APPLICATION
This application claims the benefit of provisional application 60/496,791 filed Aug. 21, 2003 in the U.S. Patent and Trademark Office, and which is incorporated herein by reference in its entirety.
GOVERNMENT FUNDING
The invention was made in part with funding from the National Institutes of Health (NIAID, Grant No. A142347). The government has certain rights in the invention.
FIELD OF THE PRESENT INVENTION
The invention relates to compositions useful in modulating DNA replication in a family of pathogenic bacteria, to methods of obtaining inhibitors of DNA replication, and compositions and methods for treating infectious disease caused by these bacteria.
BACKGROUND
The gram-negative bacterium Vibrio cholerae causes cholera, a severe and sometimes lethal diarrheal disease. The genomes of Vibrio cholerae and related Vibrio species are distributed between two circular chromosomes, chromosome I (chrI) and chromosome II (chrII). Origins of replication of the two Vibrio cholerae chromosomes are undefined, and mechanisms regulating DNA replication in Vibrio cholerae were unknown.
The family Vibrionaceae, of which V. cholerae is the most clinically important member, includes several other human and fish pathogens such as Vibrio parahaemolyticus, Vibrio vulnificus, Photobacterium damselae , and Listonella anguillarum , and is one of the predominant families of marine microorganisms (Kita-Tsukamoto et al., 1993). The genomes of V. cholerae and several related Vibrio spp. are distributed between two circular chromosomes (Trucksis et al. 1998 and Yamaichi et al. 1999). This genomic structure was originally believed to be unusual among bacteria; it is now clear that many bacterial genomes—including those of several pathogens (e.g., DelVecchio et al., 2002)—consist of more than one chromosome.
Escherichia coli , which contains a single circular chromosome, has been the primary model organism used to elucidate mechanisms that control bacterial chromosome replication. Replication in E. coli initiates from a specific region of the chromosome, termed oriC. This 258 bp stretch of DNA is capable of autonomous replication and contains recognition sites for several replication factors (Messer et al., 1996). DnaA, the initiator protein, binds to 9 bp repeats within oriC, termed DnaA boxes (Fuller et al., 1984). This interaction stimulates DNA duplex separation at an adjacent region consisting of three AT-rich repeats, resulting in the formation of an open complex (Bramhill et al., 1988). DnaA is also believed to recruit a helicase, DnaB, to the open complex to fully unwind the strands (Marszalek et al., 1994). Once this prepriming complex is formed, RNA primers are synthesized and replication proceeds bidirectionally around the chromosome.
Initiation of replication in E. coli is a highly regulated event that occurs only once per cell cycle (Boye et al., 2000). Several mechanisms are thought to control initiation in E. coli . First, the methylation state of oriC regulates initiation (Boye et al. 1990 and Marinus 1996). oriC contains eleven sites for methylation by the enzyme DNA adenine methyltransferase (Dam). Ordinarily, E. coli DNA is fully methylated. However, newly replicated oriC is hemimethylated and becomes transiently unavailable for reinitiation because it is sequestered by SeqA, a protein that preferentially binds to hemimethylated DNA (Lu et al., 1994). Second, the availability of DnaA (amount of protein per cell) controls initiation, because it is titrated by binding to several high-affinity sites around the chromosome and thereby made unavailable for binding to oriC (Kitagawa et al., 1996). Third, the initiation potential is controlled by regulation of the activity of DnaA (Katayama et al., 1998).
Virtually nothing is known regarding replication control in prokaryotic organisms with multiple chromosomes. The genome of V. cholerae is distributed unequally between its two chromosomes; chromosome I (chrI) is larger than chromosome II (chrII) and contains most but not all of the genes essential for V. cholerae growth (Heidelberg et al., 2000). The presence of essential genes on chrII indicates that it is a bona fide chromosome as opposed to a dispensable plasmid. Bioinformatic analyses revealed that the putative origin of replication of chr I has sequence similarity to the origin of replication of the E. coli chromosome, oriC (Heidelberg et al., 2000). In contrast, the putative origin of replication of chr II lacks similarity to known origins and was assigned solely on the basis of GC nucleotide skew analysis (Heidelberg et al., 2000).
SUMMARY OF THE INVENTION
The invention is based in part on the discovery of compositions that modulate DNA replication in the Vibrionaceae family of bacteria. Identified herein are two Vibrio cholerae genes, rctA and rctB, which are critical for Vibrio chromosomal replication, particularly for replication of chrII.
In one aspect, the present invention provides an isolated nucleic acid of SEQ ID NO: 1, or the complement of this nucleic acid. The term “complement” as used herein refers to standard Watson-Crick base pair hydrogen-bond rules of base pairing, in which substantially all of the nucleotides of the sequence of the complement, for example, at least about 60%, at least about 70%, at least about 80%, about 90%, about 95%, or about 98%, will form appropriate hydrogen bonds with the sequence.
Also provided is an isolated polypeptide encoded by SEQ ID NO: 1, wherein the polypeptide is capable of modulating replication of DNA in a bacterium. As generally used herein, the terms “modulating,” “modulation,” and “modulate” include both the processes of increasing DNA replication and of decreasing, i.e., inhibiting, DNA replication. Replication in general means initiation of chromosomal replication, rather than the DNA synthesis that occurs throughout the chromosome, which herein is referred to as “synthesis” or “elongation”. In embodiments of the invention, the bacterium is a Gram negative bacterium, in particular, a member of the family of Vibrionaceae, e.g., a member of the genus Vibrio , such as V. cholerae, V. vulnificus, V. fischeri, V. parahaemolyticus, V. anguillarum , or V. harveyi.
In embodiments of the invention, the DNA whose replication is modulated is V. cholerae chromosome II, or a portion thereof. As used herein, “portion” includes any fragment or other part of the DNA that is less than the complete DNA sequence. In embodiments of the invention, the portion of the V. cholerae chromosome II includes the oriCII vc . In some embodiments, this DNA is hemi-methylated DNA. Hemi-methylated DNA includes any DNA that contains one or more methylated bases (e.g., adenine methylated by DNA adenine methyltransferase) but is not fully methylated. By way of non-limiting example, hemi-methylated DNA includes between about 1% methylated DNA and about 25% methylated DNA.
In another aspect, the invention provides an isolated polypeptide comprising the amino acid sequence of SEQ ID NO: 2. In embodiments, the polypeptide is capable of modulating replication of DNA in bacteria. The term “polypeptide” means a sequence of amino acids connected by peptide bonds, and includes the term “protein”.
In a further aspect, the invention provides an isolated nucleic acid including SEQ ID NO: 3, or the complement thereof. The nucleic acid is DNA. Alternatively, the nucleic acid is RNA, or is a peptide nucleic acid which is resistant to degradation by nucleases. In embodiments of the invention, the nucleic acid is a modified nucleic acid. Modified nucleic acids are exemplified by having a cytostatic or cytotoxic agent conjugated covalently to the nucleic acid.
In another embodiment, the invention provides a method of screening for an antibacterial agent capable of inhibiting chromosome replication in a cell of a bacterial species of the family of Vibrionaceae. The method includes contacting a test cell with a putative agent; measuring replication of a nucleic acid in the test cell; and, comparing the replication with replication in a control cell not so contacted with the agent, whereby a decrease in the replication in the test cell relative to the replication in the control cell identifies the agent as being capable of inhibiting DNA replication in the bacterial cell. The nucleic acid replication can be measured by one of ordinary skill in the art using routine procedures, including measurement of cell growth such as turbidometrically or calorimetrically; specific activity of a cell enzyme, for example, one capable of cleavage of a calorimetric substrate; incorporation of a radiolabel such as 3 H-thymidine into DNA, collected for example as a tricloracetic acid precipitate of macromolecules; and cell content of a gene on chromosome II of the cell, for example, by use of PCR using probes specific for markers on chromosome II.
The bacterial cell is a member of the family of Vibrionaceae. Groups of exemplary bacteria include Aeromonas, Allomonas, Beneckea, Enhydrobacter, Listonella, Lucibacterium, Photobacterium, Plesimonas, Salinivibrio , and Vibrio . In embodiments of the invention, the bacterial cell is a pathogen, for example, a human pathogen, a fish pathogen, or a shellfish pathogen. The identified agent is bacteriostatic, meaning that it prevents bacterial growth, for example, by inhibition of initiation of chromosome replication or cell division. In other embodiments, the identified agent is bactericidal, meaning that it causes bacterial cell death.
The invention further provides a method of screening for an agent, the method including contacting a Vibrionaceae test bacterial cell with a putative agent; measuring the test rate of proliferation the bacterial cell; and comparing the test rate of proliferation with the rate of proliferation of a control bacterial cell not so contacted with the putative agent, whereby a decrease in the rate of proliferation of the test bacterial cell relative to the rate of proliferation of the control bacterial cell identifies the agent as being capable of inhibiting DNA replication in a bacterial cell.
The present invention includes a method of inhibiting DNA replication in a bacterium by contacting the bacterium with the identified agent. The present invention further includes a method of treating a patient having an unwanted bacterial cell such as a cell of a bacterium in the family Vibrionaceae, for example, a patient suffering from cholera by contacting the patient with the identified agent.
In another aspect, the present invention includes a method of inhibiting DNA replication in a bacterium, such as a member of the Vibrionaceae, by contacting the bacterium with an isolated nucleic acid comprising SEQ ID NO: 3, or the complement thereof.
In a further aspect, the present invention includes a method of inhibiting proliferation of a bacterium, such as a member of the Vibrionaceae, by contacting the bacterium with an isolated nucleic acid comprising SEQ ID NO: 3, or the complement thereof.
In a another aspect, the present invention includes a method of inhibiting DNA replication in a bacterium, such as a member of the Vibrionaceae, by contacting the bacterium with an isolated nucleic acid comprising the incompatibility determinant inc, wherein the incompatibility determinant inc is derived from a bacterium of the family of Vibrionaceae. The bacterium is selected from the group consisting of V. cholerae, V. vulnificus, V. fischeri, V. parahaemolyticus , and V. harveyi.
In a another aspect, the present invention includes a method of inhibiting DNA replication in a bacterium by contacting the bacterium with an isolated nucleic acid comprising the Vibrio cholerae chrII incompatibility determinant inc.
The present invention also provides a method of treating a patient suffering from cholera by administering to the patient a nucleic acid comprising the Vibrio cholerae chrII incompatibility determinant inc.
The present invention further includes a method of treating a patient suffering from an unwanted bacterium such as a member of the Vibrionaceae, for example, a patient with cholera, by administering to the patient a nucleic acid comprising SEQ ID NO:3, or the complement thereof.
The present invention further includes a method of treating a patient having an unwanted cell of a Vibrionaceae by administering to the patient a nucleic acid comprising the Vibrio cholerae chrII incompatibility determinant inc.
In another embodiment, the invention includes a method of treating a patient having an unwanted cell of a Vibrionaceae by administering to the patient the agent identified by the above-described methods.
In another embodiment, the invention includes treating a patient having an unwanted cell of a Vibrionaceae by administering to the patient a nucleic acid comprising SEQ ID NO:3, or the complement thereof. In certain embodiments, the bacterium or cell is Vibrio cholerae.
The invention further provides a kit for inhibiting growth of a cell of a Vibrionaceae, including a nucleic acid comprising SEQ ID NO: 3 or a complement thereof, and a container. The kit in a related embodiment also includes instructions for use. In embodiments of the invention, the nucleic acid is in an effective dose.
The invention also provides a kit for performing the methods of the invention, that includes a frozen or lyophilized culture of a Vibrionaceae, a container, and instructions for use. Optionally, the kits of the invention include a positive control reagent, such as a known DNA replication inhibitor known to one of skill in the antibiotic arts, e.g., a gyrase inhibitor, capable of inhibiting replication of the Vibrionaceae. Further, the kits of the invention may include reagents for analysis of replication.
An embodiment of the invention herein is use of a nucleotide sequence of a Vibrionaceae origin of replication for a vector. The origins of replication of the two Vibrionaceae chromosomes provided herein can be used to engineer a plasmid as a vector for handling recombinant DNA. For example the Vibrionaceae is selected from the genera Vibrio, Photobacterium , and Listonella . Further, the Vibrionaceae is selected from the group of Vibrio consisting of V. cholerae, V. vulnificus, V. alginolyticus, V. fluvialis, V. furnissii, V. proteolyticus, V. harveyi, V. parahaemolyticus , and V. fisheri . The provided the sequence in various embodiments encodes oriCI vc or oriCII vc .
Also provided is a vector comprising a nucleotide sequence according to any of SEQ ID NOs: 6–10. The vector includes at least one of a Vibrionaceae nucleotide sequence selected from the group of a DnaA box, a 12-mer repeat sequence, an IHF binding site, and an AT-rich 13-mer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show the delineation of the replication origins of the two V. cholerae chromosomes. A conjugation-based assay was used to assess the replication capacity of fragments of chrI and chrII inserted into a conditionally replication-defective vector, pGP704. pGP704-based plasmids were transferred by conjugation from the mob + donor E. coli strain SM10λpir (Miller and Mekalanos, 1988), to E. coli MC4100λpir, MC4100, and the recA pir V. cholerae strain Bah-3. The frequency of exconjugant formation was calculated by dividing the number of exconjugant colony forming units (cfu) by the number of donor cfu. The plasmid inserts are depicted as arrows for open reading frames and lines for intergenic regions. The insert in pminoriCI corresponds to the oriCI vc intergenic region shown in FIG. 2A . The insert in poriCII consists of 5.8 kb surrounding the previously annotated replication origin of chrII (Heidelberg et al., 2000), designated ig1. This insert includes vca0002 (rctB) (2), vca0001 (rctA) (1), parA (pa), parB (pb), and a fragment of vca1113 (s′). The frequencies shown are means derived from two to four experiments. Asterisks indicate that the frequency of exconjugant formation was below detection (<1.7×10 −5 ) by this assay. When pGP704 without an insert was transferred to either Bah-3 or MC4100, no exconjugants were detected.
FIG. 1A is a drawing and bar graph that shows the frequency of exconjugant formation in V. cholerae Bah-3. The X in line 7 represents a substitution of 6 bp in the fourth 12-mer repeat in ig2.
FIG. 1B is a drawing and a bar graph that shows the frequency of exconjugant formation in E. coli MC4100. The white bars in lines 9 and 10 show the frequency of exconjugant formation when the recipient was MC4100 harboring a plasmid (porf2) expressing rctB. The X in line 10 represents a frame shift at bp 79 of rctB. The black triangles within the small arrows in each of lines 11, 12, and 13, respectively, represent a stop codon at amino acid position (aa) 25, aa 1, and a deletion of bp 21 in rctA, respectively.
FIGS. 2A–2C are a drawing are photographs that show that RctB binds to oriCII vc , but not to oriCI vc , and is found in diverse genera in the family Vibrionaceae.
FIG. 2A is a schematic representation of the replication origin regions of V. cholerae chromosome I and chromosome II. AT-rich regions, DnaA boxes, IHF binding sites, GATC sequences, and small repeats are as indicated in the box. The 11-mer sequence is ATGATCAAGAG (SEQ ID NO: 4) and the 12-mer consensus is (A/T)TGATCATNN(A/T)T (SEQ ID NO: 5; see FIGS. 7 and 8 ). Hatch marks reflect 100 bp intervals, but open reading frames at the ends of each ori are not to scale. The lines below each construct represent probes used in gel shift experiments. The minimal oriCII vc as defined in FIG. 1A is shown above the oriCII vc region within the bracket on the right above the map.
FIG. 2B is a set of photographs of autoradiographs of gel shift experiments. Triangles represent increasing concentrations (0 ng negative control, 56 ng, 113 ng, 225 ng, 450 ng, and 900 ng) of His 6 -tagged RctB. Roman numerals beneath each autoradiograph represent the probes as shown in FIG. 2A .
FIG. 2C is a set of photographs of Southern analyses of chromosomal DNA digested with HindIII and probed with rctB. Lanes 1 – 13 and 17 are from species within the family Vibrionaceae (1 , V. cholerae N 16961; 2 , V. parahaemolyticus; 3 , V. alginolyticus; 4 , V. fluvialis; 5 , V. vulnificus; 6 , V. furnissii; 7 , V. proteolyticus; 8, Photobacterium damselae; 9, P. leiognathi; 10 , Listonella anguillarum; 11 , V. fischeri; 12 , V. harveyi; 13 , P. phosphoreum; 17 , V. cholerae N16961). Lanes 14 and 16 are Plesiomonas shigelloides and E. coli MC1061, respectively, from the family Enterobacteriaceae, and lane 15 is Aeromonas hydrophila from the family Aeromonadaceae.
FIG. 3 is a set of photographs of gel analyses of results from an assay for detection of RctA RNA in V. cholerae and poriCII-containing E. coli . A ribonuclease protection assay was used to detect rctA transcripts using an antisense RNA probe spanning the entire annotated vca0001 (rctA) gene. Probes for E. coli and V. cholerae rpoB transcripts were used as controls. The rctA autoradiograph was exposed for 53 hr and the rpoB autoradiographs were exposed for 5 hr. RNA was prepared from the V. cholerae strain N16961 (Vc) and the E. coli strains poriCII/MC4100 (p/Ec) and MC4100 without plasmid (Ec). Yeast RNA (Y) was used as a negative control. The sizes of the protected bands are shown to the left of the figure.
FIG. 4 is a drawing and a bar graph showing that a V. cholerae incompatibility determinant maps to the left side of ig2. DNA segments from the oriCII vc and oriCI vc regions were cloned into the high-copy vector pCRII-TOPO (obtained from Invitrogen Corp., Carlsbad, Calif.). The features of the oriCII vc and oriCI vc regions are annotated as in FIG. 2 except for a highly conserved 13 bp sequence (shown in FIG. 8 ). Each plasmid (100 ng) was used to transform electrocompetent V. cholerae N 16961, and transformants were obtained on selective media. The relative transformation efficiency was calculated as the number of transformants obtained for each plasmid compared to the number obtained with vector alone. The results shown are those of one representative experiment of at least two done for each plasmid. The asterisks in lines 1 and 2 indicate that the number of transformants was below assay detection (<3×10 −6 ). The arrows in lines 6 and 9 indicate that the relative transformation efficiency was slightly greater than 1.0.
FIG. 5 is a bar graph showing that the ig2 incompatibility determinant influences the replication region of poriCII but not poriCI. The ColD plasmid pGZ119 (V) or derivatives containing the 407 bp insert from plasmid p3642-topo (see FIG. 4 ) in either the forward (F) (plasmid pEE481) or reverse (R) (plasmid pEE482) orientation were used to transform the recA E. coli strain KB1. Where indicated, the E. coli strain harbored another plasmid: poriCII, pABfs (poriCII with frameshift mutations in parA and parB), or poriCI. Transformants were selected on LB-agar containing ampicillin (for the resident plasmid) and chloramphenicol (for the transforming plasmid). The relative transformation efficiency was calculated by dividing the number of transformants obtained for each plasmid by the number of transformants obtained with vector alone within each strain. The asterisks and crosses indicate that the relative transformation efficiency for these data points, respectively, was below detection by this assay (<0.007 and <0.13, respectively). The results shown are means of at least two experiments.
FIGS. 6A–6D are bar graphs showing that replication of poriCII and poriCI requires dam, and poriCI replication also requires seqA. A transformation-based assay was used to assess the replication capacity of four constructs. To calculate relative transformation efficiency, the number of transformants isolated from each of the four strain backgrounds was divided by the number isolated from the wild type (wt) strain and expressed as a percent. This calculation was performed separately for methylated (black or solid bars) and unmethylated (white or open bars) versions of each plasmid. Each transformation was done at least twice, and the relative transformation efficiencies were calculated using the averages from these experiments.
FIG. 6A shows the replication capacity of construct pJEL109 (Lobner-Olesen et al., 1992) (miniR1, a dam-independent plasmid) in the following strains: MC1061 (wild type (wt) E. coli ), KO1607 (Δdam), MC1061ΔseqA (ΔseqA), and KO1607ΔseqA (ΔdamΔseqA). Transformation of wild-type or dam E. coli by miniR1 occurred with similar efficiency regardless of the methylation status of the plasmid.
FIG. 6B shows the replication capacity of construct pMR2 (Jensen et al., 1990) (poriC) in the following strains: MC1061 (wild type (wt) E. coli ), KO1607 (Δdam), MC1061ΔseqA (ΔseqA), and KO1607ΔseqA (ΔdamΔseqA).
FIG. 6C shows the replication capacity of construct poriCII. The crosses indicate the following strains: methylated poriCII had a relative transformation efficiency of 0.00053 in Δdam and 0.0001 in ΔdamΔseqA, and unmethylated poriCII had a relative transformation efficiency of 0.007 in ΔAdam and 0.0001 in ΔdamΔseqA.
FIG. 6D shows the replication capacity of construct poriCI in the following strains: MC1061 (wild type (wt) E. coli ), KO 1607 (Δdam), MC1061ΔseqA (ΔseqA), and KO1607ΔseqA (ΔdamΔseqA). The asterisks indicate that the relative transformation efficiencies were less than detectable by this assay (<0.0002).
FIG. 7 is a set of nucleotide sequences from V. cholerae (SEQ ID NO.: 4), V. vulnificus (SEQ ID NO.: 5), V. harveyi (SEQ ID NO.: 6), V. parahaemolyticus (SEQ ID NO.: 7), and V. fischeri (SEQ ID NO.: 8) that were aligned using Vector NTI (InforMax). Bases that are conserved among all five species were identified, and bases conserved in at least three were identified. The putative DnaA box, having sequences conserved among all five species, is highlighted by the left-most box on line one, the 12-mer repeats are highlighted by the middle and right-most boxes on line 1 and boxes on line 2, and the AT-rich region's two 13-mers (Messer and Weigel, 1996) are highlighted boxes on lines 4 and 5.
FIG. 8 is a set of nucleotide sequences from V. cholerae (SEQ ID NO.: 9), V. vulnificus (SEQ ID NO.: 10), V. harveyi (SEQ ID NO.: 11), V. parahaemolyticus (SEQ ID NO.: 12), and V. fischeri (SEQ ID NO.: 13) that were aligned using Vector NTI (InforMax). Bases that are conserved among all five species are shown in boxes on lines 1, 2, 7 and left-most box on line 3, and bases conserved in at least three are shown in the box on line 5. The 11-mer repeats are highlighted by boxes on lines 1, 2, 7 and left-most box on line 3, the conserved 13 bp of the incompatibility determinant are highlighted in the box on the right on line 3, and the 12-mer repeat is highlighted in the box on line five.
FIG. 9 is a photograph of Petri plates that shows V. cholerae Bah-3 cells harboring the ampicillin-resistant plasmid poriCII, poriCI, pIg2, or pminIg2 (see FIG. 1 ). Cells were streaked on ampicillin-containing LB-agar and grown overnight at 37° C. Bah-3 cells without plasmid were streaked onto streptomycin-containing LB-agar and grown overnight at 37° C. Pictures were taken with a digital camera at the same magnification.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Details of various embodiments and examples of the invention are found in the publication entitled, “Distinct Replication Requirements for the Two Vibrio Cholerae Chromosomes”, by Elizabeth S. Egan and Matthew K. Waldor, to appear in (Aug. 22, 2003; Cell 114(4): 521–530) and which is hereby incorporated herein in its entirety.
EXAMPLES
The following methods were used throughout the Examples.
Plasmid and Strain Construction
DNA from V. cholerae N16961 (Heidelberg et al., 2000) was used as template for PCR amplification of fragments for insertion into pGP704 (Miller and Mekalanos, 1988) to create chrI- and chrII-derived minichromosomes. The insert in poriCI extends from chrI bp 2,956,820 through 1,300 according to the published annotation of the V. cholerae genome sequence (Heidelberg et al. 2000). The insert in poriCII extends from chrII bp 1,069,696 through bp 3,191. All primer sequences are available upon request. Frame-shift and substitution mutations were constructed using the QuikChange Site-Directed Mutagenesis Kit (Stratagene), and deletions were constructed using overlap-extension PCR mutagenesis as previously described (Moyer et al., 2001). All mutations were confirmed by DNA sequencing. High-copy plasmids containing oriCII vc or oriCI vc sequences were constructed by amplifying sequences from V. cholerae N 16961 and introducing them into the pUC-based plasmid pCRII-TOPO (Invitrogen). Plasmids pEE481 and pEE482 were constructed by introducing the insert from plasmid p3642-topo (see FIG. 4 ) into the vector pGZ119 (Lessl et al., 1992) in both orientations. Full-length rctB along with upstream sequence including its ribosome binding site was introduced into the expression vector pGZ119 (Lessl et al., 1992) to create the complementing plasmid porf2. The expression plasmid for production of C-terminal His 6 -tagged RctB, porf2-BAD, was constructed by inserting the rctB coding sequence into pBAD-topo (Invitrogen). Strain KO1607 is E. coli MC1061 dam13::tn9 (gift of A. Wright). Strains MC1061ΔseqA and KO1607ΔseqA were constructed by P1 transduction of the seqA allele from strain CM735 seqAΔ::tet (Lu et al., 1994) using standard protocols.
Conjugation Assays
Conjugation assays to determine the replication capacity of chrI and chrII-derived minichromosomes were performed by overlaying approximately equal numbers of donor and recipient cells on LB agar plates and incubating for 5 hr at 37° C. Dilutions were plated on selective medium to enumerate donor cfu, recipient cfu, and exconjugant cfu. In experiments with a complementing plasmid in trans, IPTG was added to the medium to induce gene expression. The frequency of exconjugant formation was calculated by dividing the number of exconjugant by donor cfu.
Molecular Biology Methods
Southern hybridization was carried out using horseradish peroxidase-labeled DNA probes, prepared and hybridized using the ECL direct nucleic acid labeling and detection system (Amersham Pharmacia). Genomic DNA was isolated using the Gnome DNA kit (BIO101). Nucleotide alignments were performed using Vector NTI (InforMax). The V. harveyi oriCII-region sequence (GenBank AY309011) was determined by sequencing the insert of plasmid pNH26 (Zyskind et al., 1983) using dye terminator cycle sequencing at the Tufts University School of Medicine Core Facility.
DNA Binding Assays
RctB-His 6 was affinity purified on Ni-NTA resin (Qiagen) from lysates of E. coli RJ3236 (porf2-BAD) grown in the presence of 0.02% arabinose according to the manufacturer's protocol. Probes for gel shift experiments were amplified by PCR from poriCII or poriCI DNA using a 32 P-labeled oligonucleotide. Probes were gel purified. Gel shift reactions (20 μl volume) were performed by incubating 1,000 c.p.m. of each probe with increasing amounts (0 ng, 56 ng, 113 ng, 225 ng, 450 ng, and 900 ng) of purified RctB-His 6 in a reaction buffer containing 25 mM Tris-HCl (pH 7.9), 110 mM NaCl, 5.12 mM EDTA, 2 mM DTT, 0.1 mg/ml BSA, and 12.5 μg/ml sonicated salmon sperm DNA for 30 min at room temperature. Reactions were analyzed on 6% DNA retardation gels (Invitrogen).
Rnase Protection Assay (RPA)
RNA was prepared using the Rneasy Kit (Qiagen) from exponentially growing V. cholerae N 16961, E. coli MC4100 (poriCII), and E. coli MC4100 without plasmid, and treated with Dnase I. Yeast RNA was provided in the RPA III kit (Ambion). Riboprobes were synthesized from linearized cloned DNA templates with the Maxiscript kit (Ambion) using 40 μCi of [ 32 P]UTP for rpoB and 50 μCi of [ 32 P]UTP for rctA. The expected protected fragment sizes were as follows: 132 bp for rctA, 211 bp for V. cholerae rpoB, and 1226 bp for E. coli rpoB. The corresponding full-length probes were 233 bp, 341 bp, and 1310 bp, respectively. All riboprobes were gel purified on 6% denaturing polyacrylamide gels. RPAs were conducted using the RPA III kit (Ambion) according to manufacturer's instructions using 15 μg total RNA for each sample. Products were separated on 6% denaturing polyacrylamide gels and exposed to film.
Stability Assays
For the stability tests in V. cholerae , fresh overnight ampicillin-resistant Bah-3 (Pearson et al., 1993) colonies containing the appropriate plasmid were inoculated into LB broth without ampicillin. The percentage of cfu containing plasmid was determined at times T=0 and T=6 hr after growth without selection by plating equal volumes of bacteria on selective and nonselective media.
Transformation Assays
Transformation experiments were performed with 100 ng of each plasmid using a standard electroporation protocol. Electrocompetent E. coli and V. cholerae were prepared using standard protocols. For the incompatibility assays involving two plasmids, the cells were prepared with selection for the ampicillin-resistant plasmid. Dilutions were plated on selective medium to determine the number of transformants. Unmethylated pJEL109 and pMR2 were obtained by isolating the plasmids from the dam E. coli strain KO1607. We obtained unmethylated poriCII by isolating plasmid from a dam pir + E. coli strain (SM10λpir dam 13::tn9), where replication initiates from the R6K origin of replication.
In various embodiments of the invention herein the origins of replication of the two V. cholerae chromosomes are experimentally defined. Novel replicon-specific requirements for each chromosome as well as factors that are required for replication of both chromosomes are provided.
Example 1
Delineation of oriCI vc and oriCII vc
To functionally define the genes and sequences required for replication of the two V. cholerae chromosomes, minichromosome derivatives of each chromosome were constructed by introducing each annotated (Heidelberg et al., 2000) replication origin into a mobilizable, conditionally replication-defective vector, pGP704 (Miller and Mekalanos, 1988). This vector contains the R6K origin of replication, which requires the product of the pir gene to initiate replication. In pir-deficient strains, pGP704-based plasmids will only replicate if they carry an alternate, functional replication cassette. The ability of the V. cholerae -pGP704 chimeric plasmids to replicate autonomously in both pir E. coli and V. cholerae (recA strain Bah-3 [Pearson et al., 1993]) was measured by quantifying the frequency of exconjugant formation in conjugation assays in which the plasmids were mobilized from a pir + donor to pir recipients. All of the plasmids tested were able to replicate and form exconjugants in pir + E. coli , showing that their inserts have no negative effect on pGP704 mobility (data not shown).
The annotated oriCI vc resides between the genes mioC and gidA (Heidelberg et al., 2000). A 447 bp fragment from this intergenic region replicated in both V. cholerae and the surrogate host, E. coli ( FIGS. 1A and 1B , line 1). This indicates that this fragment contains the minimal oriCI vc and demonstrates that E. coli can supply any transacting factors needed for oriCI vc -based replication. In contrast, a plasmid (pIg1) containing the intergenic region previously annotated as oriCII vc did not form exconjugants in either V. cholerae or E. coli , indicating that pIg1 cannot replicate autonomously, i.e., that this intergenic region either does not contain oriCII vc or requires additional sequences in cis for replication ( FIGS. 1A and 1B , line 3). A larger minichromosome II, poriCII, replicated in both species ( FIG. 1A and 1B , line 2), indicating that oriCII vc and any other sequences required in cis for replication are contained within the 5.8 Kb insert of poriCII. This minichromosome includes two intergenic regions (ig1 and ig2), two hypothetical genes (vca0001 and vca0002), and two genes with homology to plasmid partitioning genes (parA and parB).
Mutational analysis of poriCII confirmed that ig1 is not required for replication in E. coli ( FIG. 1B , line 4), indicating that the original annotation of ig1 as oriCII vc was incorrect. However, a deletion internal to ig2, the other intergenic region within poriCII, revealed that ig2 includes sequences required for replication in both V. cholerae and E. coli ( FIG. 1A , line 4, and FIG. 1B , line 5). Furthermore, a minichromosome containing only ig2 sequences could replicate in V. cholerae , indicating that ig2 contains the true oriCII vc ( FIG. 1A , line 5). Only the right side of ig2 was required for pminIg2 to replicate in V. cholerae , demonstrating that the minimal oriCII vc is contained within this 406 bp region ( FIG. 1A , line 6).
Unlike a plasmid containing only oriCI vc (pminoriCI), pIg2 could not replicate in E. coli ( FIG. 1B , lines 1 and 8). Instead, derivatives of poriCII required inclusion of the two flanking hypothetical genes, designated vca0001 and vca0002 by Heidelberg et al. (2000), to replicate in E. coli ( FIG. 1B , lines 6–10). Given this requirement, these genes have been herein termed vca0001, rctA (replication of chromosome two; SEQ ID NO:3) and vca0002, rctB. For rctB, a gene (SEQ ID NO:1) encoding a predicted protein product of 658 amino acids (aa; SEQ ID NO:2), both deletion and frameshift mutations severely compromised the ability of poriCII to replicate in E. coli , and in both cases the replication defects could be complemented by expressing rctB in trans on another plasmid ( FIG. 1B , lines 9–10). In V. cholerae , the RctA and RctB gene products are provided by the chromosome to facilitate pIg2 and pminIg2 replication ( FIG. 1A , lines 5–6).
Example 2
Sequence Analysis of oriCI vc and oriCII vc
The DNA sequences of both oriCI vc and oriCII vc contain several features also found in E. coli oriC. In fact, the sequence of oriCI vc is very similar to oriC (58% identity). Like oriC, oriCI vc has an AT-rich region, five apparent DnaA boxes, a likely binding site for IHF (a protein that bends DNA), and many potential sites for Dam methylation (GATC sequences) ( FIG. 2A ). Though the minimal oriCII vc lacks sequence similarity to E. coli oriC, it does contain an AT-rich region, a single putative DnaA box, a putative IHF binding site, and an overrepresentation of GATC sequences ( FIG. 2A ). In addition, within the entire ig2 region, there are two related repeat sequences, an 11-mer and a 12-mer, a finding reminiscent of replication origins found in iteron-type plasmids, where small repeat sequences are required for both replication and copy number control (Chattoraj 2000 and del Solar et al. 1998) ( FIG. 2A ).
The available nucleotide sequence databases were searched and sequences similar to ig2 were found in the complete genomes of Vibrio fischeri, Vibrio parahaemolyticus , and Vibrio vulnificus . In addition, ig2-like sequences were found in an insert of a plasmid that was isolated as part of a genetic screen for functional V. harveyi origin sequences (Zyskind et al., 1983). Alignment of V. cholerae oriCII vc with sequences from V. vulnificus, V. fischeri, V. parahaemolyticus , and V. harveyi revealed that the 11-mer repeats, 12-mer repeats, the DnaA box, and the AT-rich region were all conserved ( FIGS. 7 and 8 ). Furthermore, in each species, the 12-mers were spaced 11 bp apart, suggesting that the same DNA sequences would be displayed on the same face of the DNA. The conservation of the 12-mer repeats among five Vibrio species suggests that they are important for chrII replication. An essential replication function for the 12-mer repeats was demonstrated by the finding that substitution of six bp in a 12-mer abolished replication of pminIg2 in V. cholerae ( FIG. 1A , line 7).
Example 3
rctB is Conserved and Encodes an oriCII vc Binding Protein
Orthologs of RctB were searched and found in V. vulnificus, V. fischeri, V. parahaemolyticus , and V. harveyi (identity >74%; data not shown). Southern analysis revealed that rctB is present in diverse genera in the family Vibrionaceae, suggesting that the presence of two chromosomes may be a defining feature not just of the genus Vibrio but of the widespread family Vibrionaceae ( FIG. 2C ). In V. cholerae , all attempts to isolate mutations that inactivate rctB were unsuccessful, consistent with a conclusion that rctB is an essential gene.
As rctB is required in replication of poriCII, and replication factors often act at origins, RctB binding to oriCII vc was investigated. Recombinant epitope-tagged RctB was expressed in E. coli , purified, and used in gel shift experiments with probes derived from oriCII vc and oriCI vc . Several different probes spanning ig2 were bound by RctB, but an oriCI vc probe was not ( FIG. 2B , i–iv). With a probe derived from the left side of ig2, multiple shifted species were observed ( FIG. 2B , i), indicating that this region contains multiple RctB binding sites.
Example 4
rctA Encodes an RNA Required for oriCII vc -Based Replication
Analysis of poriCII revealed that the gene vca0001 (rctA) is required for oriCII vc -based replication ( FIG. 1B , lines 6 and 7). Further studies indicated that an RNA transcribed from this region was the required replication factor. A substitution mutation in poriCII that changed a putative RctA amino acid 25 (of 44 predicted aa) to an amber stop codon (poriCII 01amb) did not affect replication ( FIG. 1B , line 11). Similarly, replacement of the putative start codon of rctA with a stop codon did not prevent autonomous replication of the plasmid, poriCII 01TAG, in E. coli ( FIG. 1B , line 12). These data, together with the fact that there are no other potential start codons within rctA, indicate that a protein is not required for poriCII replication translated from rctA. Since pIg2 and pminIg2, which do not contain rctA in cis, replicate in V. cholerae , rctA is not a required cis-acting sequence. Together, these results suggest that a candidate product of this gene is a functional RNA. We confirmed that RNA is transcribed from rctA in both V. cholerae and poriCII-containing E. coli by performing a ribonuclease protection assay (RPA), using a probe complementary to rctA ( FIG. 3 ). The entire probe was found to be protected, suggesting that the active species encoded by this region is at least 132 bp, and potentially longer. Surprisingly, a single base pair deletion in rctA, at position 21, did inhibit replication of poriCII ( FIG. 1B , line 13). This finding confirms the requirement for rctA, and indicates that this base pair may be important in RNA structure.
Example 5
Identification of a chrII Incompatibility Determinant
V. cholerae cells containing poriCII formed smaller colonies than did cells containing poriCI or no plasmid ( FIG. 9 ). This phenotype was not attributable to coding regions in poriCII, as cells containing pIg2 (which lacks coding sequences) also formed small colonies ( FIG. 9 ). Furthermore, only a portion of ig2 accounts for this phenotype, as cells with pminIg2, a plasmid that only includes the minimal oriCII vc , formed normal-sized colonies ( FIG. 9 ). Colonies formed by E. coli containing poriCII or poriCI were indistinguishable from each other and from cells without plasmid. These findings suggested that a plasmid-borne copy of a region on the left side of ig2, outside of the minimal oriCII vc , restricted V. cholerae growth in the presence of selection for the plasmid. This impairment may result from instability of plasmids containing this region or from an inhibitory effect of this region on chrII replication. The percentage of V. cholerae cells retaining pIg2 fell more than 2000-fold during a six-hour growth period in the absence of antibiotic selection (Table 1). In contrast, pminIg2 was relatively stably maintained (Table 1). The profound difference in the stability of pminIg2 and pIg2 suggests that the left side of ig2 renders pIg2 unstable in V. cholerae , but is also consistent with ig2-mediated inhibition of chrII replication leading to a large selective advantage for cells that lose the plasmid. Together, these results indicate that the small colony phenotype was attributable to antibiotic-mediated killing of cells without plasmid, likely reflecting incompatibility between pIg2 and one or both of the V. cholerae chromosomes.
TABLE 1 pIg2 Is Unstable in V. cholerae Frequency of Amp Resistance 2 Plasmid 1 T = 0 T = 6 hours Fold Decrease 3 pIg2 3.9 × 10 −2 1.8 × 10 −5 2167 pminIg2 2.7 × 10 −1 2.0 × 10 −2 14
The presence of a chrII incompatibility sequence was confirmed by transforming V. cholerae with a high copy number vector containing chrII or chrI sequences and measuring the transformation efficiency compared to vector alone. When high-copy poriCII-topo, pIg2L-topo, or a 407 bp segment from the left side of ig2 (p3642-topo) were introduced into V. cholerae , the transformation efficiency was more than 90,000-fold lower than the efficiency of transforming vector alone ( FIG. 4 , lines 1–3). In contrast, high-copy pminIg2 (pminIg2-topo) transformed V. cholerae almost as efficiently as vector alone ( FIG. 4 , line 4), confirming that an incompatibility determinant (inc) is contained within the left side of ig2. Additional mapping experiments revealed that incompatibility depends on a short highly conserved sequence present in V. cholerae, V. vulnificus, V. harveyi, V. parahaemolyticus , and V. fischeri ( FIG. 4 , lines 5–6; Supplemental FIG. S2). While this conserved region clearly contributes to incompatibility, it is not the sole determinant, because a smaller insert (in pRT-topo) that included the conserved segment transformed V. cholerae efficiently ( FIG. 4 , line 7).
Unlike chrII minichromosomes and high-copy oriCII vc sequences, plasmids containing oriCI vc sequences were not incompatible with V. cholerae . High copy number plasmids containing either a 5.2 kb region encompassing oriCI vc (poriCI-topo) or the minimal oriCI vc (pminoriCI-topo) were readily introduced into V. cholerae and did not compromise viability ( FIG. 4 , lines 8–9). In this regard, oriCI vc is similar to E. coli oriC, which in relatively high copy is not toxic in E. coli.
To test whether sequence from the left side of ig2 (termed inc) specifically interfered with the replication regions of one or both V. cholerae chromosomes, E. coli containing either poriCII or poriCI was used so that the V. cholerae minimal replicons could be studied in relative isolation. The transformation of poriCII-containing E. coli by a vector containing the inc region (pEE481 or pEE482) was >10,000-fold lower than by vector alone ( FIG. 5 ). The orientation of inc in the vector did not alter this effect ( FIG. 5 ). When these plasmids were introduced into either poriCI-containing E. coli or E. coli without a minichromosome, there was virtually no difference in the transformation efficiency between vector alone and vector with insert ( FIG. 5 ). Thus, inc renders a vector incompatible with poriCII but not poriCI; these findings are consistent with a role for inc in control of chrII but not chrI replication and/or partitioning.
To begin to define the mechanism of incompatibility, frameshift mutations in the putative poriCII were created partitioning genes parA and parB. The resulting plasmid, pABfs, was still incompatible with pEE481 and pEE482 in E. coli ( FIG. 5 ), suggesting that incompatibility is not due to interactions of the left side of ig2 with these putative partitioning proteins. Instead, incompatibility appears to result from an influence of the inc region on the chrII replication machinery. Since pABfs contains both rctA and rctB and depends on them for replication, we hypothesize that the incompatibility region negatively regulates chrII replication by interacting with RctA and/or RctB.
Example 6
Minichromosomes Derived from the V. cholerae Chromosomes are dnaA-Dependent
Replication of many bacterial chromosomes and some plasmids is mediated by DnaA, which binds to the ori and stimulates strand unwinding to initiate replication (Hansen et al. 1986 and Messer et al. 1996). DnaA proved essential for replication of minichromosomes derived from both V. cholerae chromosomes, as neither of these plasmids could replicate in a dnaA-independent E. coli strain (Table 2). Thus, dnaA differs from rctB and rctA, which are only required for chromosome II replication. Since the activity of DnaA is regulated in a cell cycle-dependent fashion (Kurokawa et al. 1999), this protein may help coordinate replication of the two chromosomes.
TABLE 2
DnaA Is Required for Replication of poriCII and pminoriCI
Frequency of Exconjugant Formation 2
Plasmid 1
E. coli dnaA + pir 3
E. coli dnaA pir 4
poriCII
1.1 × 10 −1
9.4 × 10 −6
pminoriCI
7.0 × 10 −2
<2.3 × 10 −6
CloDF13
1.0 × 10 −1
5.0 × 10 −2
Example 7
DNA Adenine Methyltransferase (dam) is Required for V. cholerae Replication
The roles of dam and DNA methylation in replication of the two V. cholerae minichromosomes were compared to its role in replication of an oriC minichromosome, since Dam methylation sites are overrepresented within all three sequences (see FIG. 2A ). In E. coli , dam is not essential for oriC replication, but Dam methylation regulates the timing of replication initiation at oriC (Boye et al. 2000 and Marinus 1996). As has been observed in several previous studies (e.g., Lu et al. 1994 and Russell et al. 1987), a methylated E. coli oriC minichromosome was found to transform dam E. coli ˜ 1000-fold less efficiently than wt E. coli ( FIG. 6B ). This reduction has been attributed to the binding and sequestration of hemimethylated oriC DNA by the SeqA protein to prevent reinitiation (Campbell et al., 1990 and Lu et al. 1994). When methylated poriC is used to transform dam E. coli , it is replicated once and then becomes hemimethylated and sequestered. Replication cannot be reinitiated because there is no Dam methylase in the cell. Consistent with this mechanism, dam E. coli can be transformed almost as efficiently as wt E. coli when unmethylated DNA is used ( FIG. 6B ). Similarly, methylated poriC is able to transform a dam seqA double mutant because SeqA-mediated sequestration of oriC no longer occurs (Lu et al., 1994) ( FIG. 6B ).
Dam plays a different role in replication of the V. cholerae minichromosomes than it does for poriC. Transformation of dam E. coli by methylated poriCII was ˜10,000-fold less frequent than transformation of isogenic wt E. coli . Unlike poriC, unmethylated poriCII did not transform dam E. coli , suggesting that replication of poriCII absolutely requires Dam methylation ( FIG. 6C ). Consistent with this idea, poriCII did not transform a dam seqA double mutant ( FIG. 6C ). This indicates that methylation of oriCII vc contributes directly to its replication rather than or in addition to simply being a target for sequestration.
Dam methylation is required for poriCI replication as well, since dam E. coli could not be transformed with methylated poriCI ( FIG. 6D ). Surprisingly, seqA E. coli could not be transformed with poriCI, suggesting that seqA is required for replication of poriCI ( FIG. 6D ). Attempts to knock out V. cholerae seqA (54% identity and 69% similarity to E. coli SeqA) were unsuccessful, indicating that seqA is an essential gene in V. cholerae . In E. coli , several activities of SeqA contribute to control of replication. In addition to its role in binding and sequestering hemimethylated origin DNA, SeqA has been shown to influence transcriptional regulation, DNA superhelicity, and nucleoid structure (Slominska et al. 2001 and Weitao et al. 2000). The data herein indicate that in V. cholerae , seqA plays distinct roles in replication of chrI and chrII. Given the different effects of a seqA mutation on replication of poriCI and poriC, the roles of seqA in V. cholerae may prove to be different from those described in E. coli.
Example 8
Sequences
The sequences below were obtained and entered into the public database, GenBank Accession No.: NC — 002506.
RctB nucleic acid (nucleotides 1134-3110 of NC — 002506) is SEQ ID NO: 1 as used herein and in the claims has the following nucleotide sequence:
atgagctcagaagaaaaacgattgatcaaattgccaagaactcacaaagatggtcatctttttgaagtctctgaagccgcgattgac (SEQ ID NO: 1) tggattgaacagtatcaacactttaaaggtgtcacgaaaagcattgttgaacttttgaatctgatctcactgcgtggattacgcagt agagatggcttagtttcaaccacagaactgattgatgcaaccgatgggcagctgacgcgtgcagccatccagcagcgcttgagagca gcggtagctgttggattgttcaaacaaatcccagtgcgttttgaagaggggctggctggcaaaaccatgctccatcgtttcattaac cccaaccaattgatctcggtactcggctcaaccagcttagtcactgaatcggttaagcaaaatgaaaagcaaaagcgctcaaaagca ttagcgcagacgcaagtcaatcaacgtactgcatgagcatggtttaaatacaccgccagccatgaaagatgaggctgatcagtttgt ggtctcaccgactaactgggcagggatcattgatcaagcgttagcgccacccagaacccgcaagagctaccaaaagtctatggtttc gatatcgggtactcgtgctgtgattgaaacacgatcgtctaaaaacatcatgacggtcgacgatctgatgactttgtttgccttatt cactttaacagtgcaataccatgatcatcaccaagatgattaccatttcaatgctaaacaagcaccaaacaaaacgccgctgtatat caccgacattctctctttacgtggcaaaaaagacagcggcccggcacgtgactcgatccgtgacagtattgatcgtattgaatttac cgattttcagttgcatgaactgacgggtcgttggctcagtgagaatatgccagaaggctttaaaagcgatcgttttcgctttttagc gcgcaccatcaccgcttccgaagaggcacctgtggaaggcagtgatggcgagatccgcatcaaacccaatctgtacattttggtgtg ggagccttcgttttttgaagagctattgacgcgagattatttcttcctatttccaccggagatcttgaaacaacataccttggtatt tcagctctactcctatttccgtagccgaatgtctcgtcgtcataccgatgtaatgatgctgagtgaactcaaccaaaaattggccag aaacatcgaatggcgacggttttctatggatctgatccgcgaacttcgtcgtctctccgaagggaaggggagtgaagatctgtttgt ggtcaatctctggggttatcacttgactgtgaaaagcattgaagagaaaggcaaagtggtggattaccaagtcgatatcaaatgtga tgtggaagaggtactgcgctattcacgcgccaaaaccaccaacgcgggtaaacgcaatatggctccaaccttgcctaaccctttacg taacgagctggtttccaagcagaaactggctgagttatcgagcatcatcgatggtgaatttgaaccaatccagcgcaaagccccttc gccgagaggccgcttaggtcggcgcgtgaagctacgtaaacatcttgtcgaaatcaatgctgatgaaatcaccattactctatcgcg ttatacctctccagaagcgctagaacgcagtataacggctttagcggctatgactggacacgccccttcatcaatcaaagaagagtg tgtagagctcatagacaagctagattggctgcgtgttgaaaacgatgtgatccaatacccgacttgagcaagctgcttgagctctac aacagccaaaatgagagtaaacatctgtcgatcgaaaaattgatcgcaggtttagcggtacgccgtaaagtctgtaaattggttcaa gatgggcacattgacgaaacggtgtatcgagccttagatgagatggccgctggagcctaa
RctB gene product (658 amino acids) as used herein and in the claims is SEQ ID NO: 2, and has the following amino acid sequence:
(SEQ ID NO: 2) MSSEEKRLIKLPRTHKDGHLFEVSEAAIDWIEQYQHFKGVTKSIVELLNL ISLRGLRSRDGLVSTTELIDATDGQLTRAAIQQRLRAAVAVGLFKQIPVR FEEGLAGKTMLHRFINPNQLISVLGSTSLVTESVKQNEKQKRSKALAQTQ VNQRLLHEHGLNTPPAMKDEADQFVVSPTNWAGIIDQALAPPRTRKSYQK SMVSISGTRAVIETRSSKNIMTVDDLMTLFALFTLTVQYHDHHQDDYHFN AKQAPNKTPLYITDILSLRGKKDSGPARDSIRDSIDRIEFTDFQLHELTG RWLSENMPEGFKSDRFRFLARTITASEEAPVEGSDGEIRIKPNLYILVWE PSFFEELLTRDYFFLFPPEILKQHTLVFQLYSYFRSRMSRRHTDVMMLSE LNQKLARNIEWRRFSMDLLRELRRLSEGKGSEDLFVVNLWGYHLTVKSIE EKGKVVDYQVDIKCDVEEVLRYSRAKTTNAGKRNMAPTLPNPLRNELVSK QKLAELSSIIDGEFEPIQRKAPSPRGRLGRRVKLRKHLVEINADEITITL SRYTSPEALERSITALAAMTGHAPSSIKEECVELIDKLDWLRVENDVIQY PTLSKLLELYNSQNESKHLSIEKLIAGLAVRRKVCKLVQDGHIDETVYRA LDEMAAGA
RctA (nucleotides 112-246 of NC — 002506) as used herein and in the claims is SEQ ID NO: 3, and has the following nucleotide sequence:
(SEQ ID NO: 3) tcacttatttacaatgtaaagccacgttttgaagtgatgatgaataaata aaagcgagccgtaagcggaacgattaaaccgagccactaagttacggtga atgccattctgattgaaatgatgcgcaggattcaa
Discussion
The Origins of Replication of V. cholerae chrI and chrII
The basic features of E. coli oriC have, until now, been thought to define chromosomal origins of replication in γ-proteobacteria (Messer and Weigel 1996 and Zyskind et al. 1983). Examples herein show that while oriCI vc largely conforms to this pattern, i.e., oriCII vc shares certain features with oriC, including a DnaA box, several sites for Dam methylation, and an AT-rich region, this origin also has several unusual features for a bacterial chromosome. Unlike other known chromosomes, oriCII vc -based replication was determined to require, in addition to DnaA, a novel DNA binding protein, a repeat sequence, and an RNA; furthermore, a noncoding sequence negatively regulates chrII replication.
Our assertion that oriCII vc represents the true origin of replication of chrII is supported by a genetic screen for origins of replication in V. harveyi (Zyskind et al., 1983). This study led to the isolation of an autonomously replicating sequence that we show herein contains a sequence similar to oriCII vc . Furthermore, the oriCII vc region is conserved among at least three other Vibrio species, and rctB was found in many diverse members of the family Vibrionaceae, so that these are general among this family.
An RNA is Required for poriCII Replication
Several examples indicate that the rctA gene product is an RNA and not a protein. First, neither of two different single base pair changes within rctA affected replication of poriCII even though both of these mutations introduced stop codons into the predicted rctA open reading frame (ORF), one of which was at the start codon ( FIG. 1B , lines 11–12). Second, rctA is not conserved among related Vibrio species. A lack of conservation at the DNA sequence level might be expected for a functional RNA, which could retain conservation at the structural level. Finally, new algorithms for ORF identification that account for codon usage suggest that there is no protein-coding gene in the area of rctA (Guo et al., 2003). An RNA that spans the annotated vca0001 gene was detected by RPA analysis, but the precise boundaries and function of the RctA RNA are not known. transacting RNA molecules have been described in plasmid replication (del Solar et al., 1998), and in E. coli , transcriptional activity at oriC is believed to influence replication efficiency (Messer and Weigel, 1996). RctA RNA may function directly in replication (e.g., as a primer) or may play a required regulatory role.
A Negative Regulator of chrII Replication
An incompatibility determinant that was localized to a DNA sequence adjacent to the minimal oriCII vc region was found to negatively influence oriCII vc -but not oriCI vc -based replication. Plasmid replication is often controlled by negative regulators (del Solar et al., 1998), which maintain copy number within a narrow range to avoid overtaxing the host. Plasmid inc regions can negatively regulate replication by titration of essential replication factors (either protein or RNA) (del Solar et al. 1998 and Novick 1987) or by “handcuffing,” in which Rep proteins bound to the ori sterically hinder replication initiation (Chattoraj, 2000). Data herein, without being limited by any particular theory or mechanism, are consistent with either regulatory mechanisms controlling oriCII vc -based replication, presumably by influencing of these availability of RctA and/or RctB or by RctB-mediated handcuffing of oriCII vc . If this is the case, replication of chrII may at least in part be controlled independently of chrI.
Is oriCII vc Plasmid-Like?
OriCII vc -based replication has four features that characterize certain plasmid replicons: a repeat sequence essential for replication, a dependence on a replicon-specific protein (RctB), a requirement for an RNA (RctA), and an incompatibility determinant (inc) that appears to act as a negative regulator. Therefore that chrII may originally have been acquired as a plasmid and subsequently captured essential genes (Heidelberg et al. 2000). Since we found that the V. cholerae replication protein-encoding gene rctB is present in many genera of the family Vibrionaceae, the hypothetical plasmid ancestor of chrII must have been acquired prior to diversification of this family.
Some of the plasmid-like attributes of oriCII vc -based replication are different from those of characterized plasmids, and the four novel features have never been described together in a single replicon. The origins of replication of iteron-type plasmids are characterized by the presence of short repeated sequences (iterons) to which a plasmid-encoded replication protein (Rep) binds (del Solar et al., 1998). Rep binding to iterons in the ori stimulates strand unwinding, and Rep-iteron interactions, both within the ori and in nearby control regions, are involved in controlling copy number through handcuffing (Chattoraj, 2000). While RctB may be classified as a Rep protein and the 11-mer and 12-mer sequences in oriCII vc as iterons however, data herein suggest that these repeats do not function as typical plasmid iterons. Though the 12-mers are required for oriCII vc -based replication, in gel shift assays a single 12-mer was not bound by RctB. Furthermore, RctB bound to probes containing no apparent repeat sequences ( FIG. 2B , iii). The 11- and 12-mer repeats in oriCII vc also do not appear to function as iterons in replication control. In the iteron plasmid P1, a single iteron can exert incompatibility because it is bound by Rep and can therefore facilitate handcuffing (Papp et al., 1994). In contrast, in V. cholerae a sequence with six 12-mer repeats was not sufficient to exert incompatibility ( FIG. 4 , line 4). Even if RctB functions analogously to a plasmid Rep protein, it is important to note that RctB has no sequence similarity to known plasmid Rep proteins and has no recognizable motifs.
Control of Replication in a Bacterium with Two Chromosomes
How of a bacterium with multiple chromosomes, to ensure that each daughter cell. At least three general scenarios regarding replication, receives a full genome complement at cell division, can be envisioned: (1) each chromosome replicates using the same factors, (2) the chromosomes have entirely distinct replication requirements, or (3) the chromosomes share some common factors yet also maintain some distinct requirements. Analysis of the two V. cholerae chromosomes herein revealed that replication of each chromosome involved specific factors (rctB, rctA, and a control region for chrII and seqA for chrI), and that the chromosomes also shared a requirement for certain factors (dnaA and dam). Having some common and some distinct factors may be biologically favorable in a multichromosomal bacterium because this mechanism could allow for some degree of coordinated replication while minimizing competition among the replicons.
Since the two Vibrio chromosomes appear to have coexisted throughout Vibrionaceae speciation, we presume that there is coordination of their replication (unlike the unlinked replication of plasmids and their hosts' chromosomes (del Solar et al., 1998). Without being bound by any particular mechanism of action, the factors shared by both chromosomes, including DnaA and Dam methylation, may mediate this coordination. V. cholerae DnaA is very similar to that of E. coli (79% aa identity), and E. coli DnaA can enable both oriCI vc - and oriCII vc -based replication, suggesting that V. cholerae DnaA may function and be regulated as in E. coli . Sharing this essential and highly regulated (Katayama et al. 1998 and Kitagawa et al. 1996) initiation factor could ensure that replication of each chromosome is initiated only during a small time window in each cell cycle.
The other major shared factor identified, herein, Dam methyltransferase, may be essential for replication of both V. cholerae chromosomes. This observation may explain why dam is an essential gene in V. cholerae (Julio et al., 2001). Aside from its role in regulation of replication in E. coli , dam to influences DNA structure in some origins of replication, such as the P1 plasmid ori (Abeles et al. 1993). However, the requirement for dam in V. cholerae may differ from that P1, in because unmethylated P1-derived plasmids can transform dam E. coli (Abeles et al. 1993). Dam may play several roles in V. cholerae chromosome replication. As in E. coli , it may remethylate DNA that has been sequestered by SeqA due to hemimethylation. However, it is clear that dam must also play additional roles, since poriCII could not replicate in a dam host even in the absence of seqA. The methylation state of oriCII vc could affect binding of replication factors including RctB or RctA. Alternatively, oriCI vc and oriCII vc structures may be influenced by methylation in a manner similar to the ori of P1; providing a means by which the two V. cholerae origins are activated by methylation in a cell-cycle dependent and potentially synchronous manner.
Since the sequences of oriCI vc and oriC are similar, it is surprising that dam appeared essential for oriCI vc -based replication ( FIG. 6D ). It is possible that poriCI competes with the E. coli host chromosome for the available initiator molecules in the absence of Dam methylation. Such competition is believed to result in integration of oriC minichromosomes into the chromosome of dam E. coli (Lobner-Olesen and von Freiesleben 1996); in the absence of sufficient sequence homology for poriCI integration, competing poriCI plasmids may not be maintained in dam E. coli . If poriCI does compete with oriC in the absence of Dam methylation, then dam must regulate oriCI vc -based replication. The importance of dam in both oriCII vc - and oriCI vc -based replication is consistent with a role for Dam methylation in coordination of replication of the two V. cholerae chromosomes.
A bipartite genomic arrangement has persisted throughout Vibrionaceae speciation. Since there are many duplicated loci present on both V. cholerae chromosomes, it is surprising that the two chromosomes have remained separate replicons throughout evolution. Division of the genome into two chromosomes may provide an evolutionary advantage either by facilitating a faster replication time or by allowing for chromosome-specific replication control in certain environmental circumstances. This evolutionary advantage might be eclipsed by competition between two replicons with identical replication initiation factors. The distinct replication requirements of chrI and chrII may minimize competition and thereby help ensure the maintenance of the divided genome.
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Zyskind, J. W., et al., 1983. Chromosomal replication origin from the marine bacterium Vibrio harveyi functions in Escherichia coli : oriC consensus sequence. Proc. Natl. Acad. Sci. USA 80, pp. 1164–1168.
EQUIVALENTS
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of the present invention and are covered by the following claims. The contents of all references, issued patents, and published patent applications cited throughout this application are hereby incorporated by reference. The appropriate components, processes, and methods of those patents, applications and other documents may be selected for the present invention and embodiments thereof. | The invention relates to compositions, methods and kits useful in modulating bacterial cell DNA replication and for treating pathogenic bacterial. | 2 |
RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 08/274,075 filed Jul. 12, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention relates to rebuildable spin-on filters. More particularly, the present invention relates to rebuildable spin-on filters for lubricating oil.
BACKGROUND OF THE INVENTION
Most internal combustion engines utilized in automotive vehicles and the like are lubricated by circulating lubricating oil. The lubricating oil entrains solid contaminant particles resulting from engine wear, dirt entering the engine during operation and products of combustion. In order to prolong engine life, it is necessary to remove these contaminant particles. This is done by circulating the lubricating oil through a filter medium which in most cases is in the form of corrugated filter paper retained in a metal canister. As time passes, the filter paper becomes clogged. Engine manufacturers strongly suggest that the filter assembly, which includes the filter paper medium, be replaced after several thousand miles. The used filter assemblies must then be disposed of. Since the filter assemblies necessarily contain oil trapped in both the filter canister and in the filter medium, each used filter assembly is a potential source of pollution if disposed of in a conventional manner by deposit in a land fill. Since oil filters are usually replaced at least two to three times per year, used oil filters placed in land fills can contaminant ground water.
In order to protect the ground water, a number of states have now passed ordinances prohibiting disposing of used, canister-type, lubricating oil filters in landfills. This development has resulted in a need to reconfigure oil filters to accommodate these new regulations.
SUMMARY OF THE INVENTION
It is a feature of the present invention to provide an oil filter assembly which facilitates disposal of used oil filters while minimizing the environmental impact of such disposal.
In view of this feature and other features, the present invention is directed to a filter assembly useful for filtering lubricating oil circulated through internal combustion engines wherein the filter assembly includes a housing formed about an axis. The housing has a front end and a rear end with an end wall at the front end extending radially with respect to the axis. A plurality of inlet ports are positioned in the end wall and communicate with the interior of the housing. The inlet ports are distributed around the axis of the housing in spaced relation to the axis. An outlet port in the end wall is aligned with the axis of the housing and a removable end cap is secured to the rear end of the housing. An annular filter element is retained within the housing and has a hollow core surrounded by an annular filter medium with an outer cylindrical surface and an inner cylindrical surface disposed between front and rear end supports. The annular filter element is removably disposed within the housing with the inner surface of the filter medium isolated from the outer surface, wherein fluid flowing into the inlet ports passes through the filter medium and out through the outlet port. Since the filter element structure is readily separable from the housing, it can be separately disposed of, significantly reducing the amount of used lubricating oil which is disposed of by being trapped in or with the filter element.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a side view, partially in elevation, illustrating a first embodiment of the filter assembly configured in accordance with the principles of the present invention;
FIG. 2 is a side elevational view of a filter element removed from the assembly of FIG. 1;
FIG. 3 is a front view of the filter assembly of FIG. 1;
FIG. 4 is an enlarged side view, partially in elevation of a first embodiment of a threaded mounting stud utilized with the filter assembly of FIG. 1;
FIG. 5 is a side view, partially in elevation illustrating a second embodiment of the threaded mounting stud used with the assembly of FIG. 1;
FIG. 6 is a side elevation of a cylindrical filter housing utilized with the filter assembly of FIG. 1;
FIG. 7 is a planar view of an end cap used with the filter assembly of FIG. 1;
FIG. 8 is a side view, partially in elevation, of the end cap of FIG. 7;
FIG. 9 is a side view, partially in elevation, illustrating a second embodiment of the invention; and
FIG. 10 is a side elevation of a bypass valve used with the second embodiment.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a first embodiment of a rebuildable spin-on filter assembly, filter assembly 10, configured in accordance with the principles of the present invention for use with internal combustion engines (not shown). The filter assembly 10 includes an annular filter element 11 retained within an aluminum housing 13 which is concentric with an axis 14. The filter element 11 includes a pleated filter media 12 retained between a radially open front end support 15 and a radially closed rear end support 16, which supports extend radially from a unitary annular core support 18 having circular holes 20 therethrough which communicate with a hollow core 21. In a preferred embodiment, the filter medium 12 is configured of pleated paper having exterior and interior surfaces with the interior surfaces being in communication with the holes 20 in the core support 18 and the exterior surfaces being in communication with a space 22 provided in the assembly 10. As will be explained further hereinafter, oil in the space 22 flows through the pleated filter media 12 and the holes 20 in the core support 18 to emerge in a filtered state in the hollow core 21.
Referring now to FIG. 2, it is seen that the filter element 11 is a discrete, integral unit which is separable from the filter assembly 10. In accordance with the principles of the present invention, when the oil in the engine is changed, the filter element 11 is disposed of separately instead of being disposed of with the entire assembly 10. Since the filter element 11 has a hollow core 21, oil in the hollow core 12 is separated from the filter element when the filter element is removed from the assembly. Accordingly, the only oil remaining is the residue of oil coating the surfaces of the filter element 11 and the residue remaining within the material forming the pleats of the filter media 12.
A suggested method of disposing of the used filter elements 11 is incineration the filter elements at very high temperatures in order to minimize air pollution and then to dispose of the ash in a conventional environmentally safe manner.
Another method might be to wash the filter elements with detergent solution to separate the oil therefrom and then to separate the oil from the solution for environmentally safe disposal. The cleaned filter elements 11 are then disposed of, or recycled, in an environmentally safe manner.
In order to facilitate separation of the filter element 11 from the assembly 10, the filter element is slidably received within the aluminum housing 13 which is used in place of the conventional disposable canister. The housing 13 comprises a first end 31 and a second end 32. The structure of the first end 31 is best seen in FIGS. 1 and 3 wherein a unitary end wall 33 includes a first annular groove 34 (FIG. 1) and a second annular groove 35 (FIG. 1). The annular groove 34 seats a first annular gasket 36 while the second annular groove 35 seats a second annular gasket 38 which is spaced from and concentric with the first annular groove. A recessed portion 39 formed in the end wall interiorly of the gaskets 36 and 38 includes six inlet ports 40 and an internally threaded outlet port 42.
The internally threaded outlet port 42 is defined by either the steel mounting stud 50 of FIG. 4 or the steel mounting stud 52 of FIG. 5 which differ slightly from one another in that the mounting stud 50 has a shoulder 54 thereon. The studs 50 and 52 have internal threads 56 and 58, respectively, for threading with an inlet tube of the engine (not shown) and external threads 60 and 62 for threading with internal threads 64 (see FIG. 1) in the end wall 33.
As is seen in FIG. 6, the housing 13 includes a barrel portion 70 which is unitary with and extends from the end wall 33. The barrel portion 70 defines the space 22 into which oil flows from the input ports 40. The second end of the cylindrical housing 32 includes internal threads 72 and a groove 74 with an axially facing gasket 76.
Referring now primarily to FIGS. 7 and 8, a threaded end cap 80 having radially extending flange 82 and a plug portion 84 which is externally threaded with threads 86, threads into the rear end 32 of the housing 13 to close and seal the rear end of the housing. In order to facilitate attaching and removing the end cap 80, a square recess 88 is formed through the outer surface 90 of the end cap. The recess 88 receives non-rotatably the head of a tool (not shown) so that the end cap 80 may be rotated in order to be screwed into or unscrewed from the barrel portion 70 of the housing 13. The outer surface 90 and the inner surface 91 of the end cap 80 are preferably substantially planar in a radial direction with respect to the axis 14 of the filter assembly 10, thus configuring the end cap as a disk and minimizing the axial length of the filter assembly.
Preferably the barrel portion 70 and end cap 80 are both fabricated by being cast of aluminum while the mounting studs 50 and 52, which couple directly with the engine are made of steel.
Referring again to FIG. 1, in order to facilitate retaining the filter element 11 tightly within the barrel portion 70 of the housing 13, an annular spacing gasket 100 of resilient material is disposed between the rear end plate 16 of the filter element and the end cap 80. The spacing gasket 100 has a radial width greater than its axial thicknesses. A coil spring 102 is disposed within a spring steel up-front bypass valve 104. The up-front bypass valve 104 is configured to allow the filter element 11 to be bypassed if the filter media 12 becomes clogged. The up-front bypass valve 104 bears against a molded anti-drainback valve 106 which closes to seal the inlet ports 40 when the engine (not shown) on which the filter assembly 10 is mounted is not running.
In the present embodiment, up-front bypass valve 104 and anti-drainback valve 106 are components which are slidably received in the housing 13 and are slidably removed from the housing so as to be disposed of when the filter element 11 is changed. These retaining elements are furnished as a kit and are replaced each time the filter assembly 10 is "rebuilt" with a fresh filter element 11. Preferably, the spacing gasket 100 is integral with the filter element 11 and is disposed of and introduced each time the filter element 11 is changed.
When it is necessary to change the filter element 11, lubricating oil within the housing 13 (including the oil in hollow core 21) is drained into a container (not shown) upon removing the rear end cap 80. Consequently, the bulk of the oil within the oil filter assembly 10 is recycled in the same manner as oil drained from the engine block. Accordingly, the only oil which must be disposed of by an approach other than the usual recycling, is residual oil coating the filter element 11 and suspended in the material of the filter media 12.
Referring now to FIGS. 9 and 10, there is shown a second embodiment, filter assembly 110, of the invention which is similar to the first embodiment. The second embodiment 110 differs from the first embodiment 10 of FIG. 1 in that the bypass valve 120 of the second embodiment 110 is disposed between the threaded end cap 80 and a coil spring 122 instead of between the filter element 11' and an anti-drainback valve, as is the case with the bypass valve 104 of FIG. 1. In the embodiment of FIGS. 9 and 10, the spacing gasket 100 is not used because the assembly is biased together with coil spring 122.
As is seen in FIG. 10, the bypass valve 120 is a separate component with an internal coil spring 124 which biases a valve plate 126 to its closed position. When pressure in the housing 10 exceeds a predetermined level, the force exerted by the spring 124 is exceeded pushing the valve plate to an open position so that the lubricating oil flows through the bypass valve into the hollow core 21' of the filter element 11'. The bypass valve 120 and coil spring 122 are separate from the filter element 11 so that when the filter element is disposed of, the bypass valve 120, coil spring 122 and filter element (which includes the oil soaked filter media 12) are disposed of (or perhaps recycled) separately.
In the embodiment of FIG. 9, the filter element 11' has an end plate 16' which is annular so that the bypass valve 120 seats in the hollow core 21' of the filter element. The force of the coil spring 122 bearing on the bypass valve 120 urges the filter element 11' against an annular filter element support 128, which in turn seats against the end wall 33 at the first end 31 of the aluminum housing 13. The aluminum housing 13 is therefore useable with either the first embodiment of the invention (FIG. 1) or the second embodiment of the invention 110 (FIG. 9).
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. | A spin-on type filter assembly for lubricating oil includes a cast aluminum housing which contains a replaceable annular filter element. The filter element is resiliently retained in the housing by compressing a gasket thereon with a threaded end cap which closes one end of the housing. The housing includes a unitary front end wall with a plurality of inlet ports surrounding an axially positioned outlet port. In order to provide a secure coupling with the engine, an externally and internally threaded steel stud is threadably mounted in the outlet port for threadably coupling with the engine. | 1 |
CROSS-REFERENCE TO PRIOR APPLICATIONS
This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2010/006807, filed on Nov. 9, 2010, and claims benefit to German Patent Application No. DE 10 2009 058 429.3, filed on Dec. 16, 2009. The International Application was published in English on Jun. 23, 2011 as WO 2011/0072777 under PCT Article 21(2).
FIELD
The present invention relates to a process for producing geopolymers from oil shale and/or mineral residues, which originate from the production of oil by means of oil shale.
BACKGROUND
Geopolymers are inorganic aluminosilicate polymers, which are obtained by polycondensation at high pH values and low temperatures (room temperature). By means of an alkaline medium, Si(OH) 4 and [Al(OH) 4 ] monomers or also oligomers initially are released from the solid material. Subsequently, solidification is effected by polycondensation, whereby an aluminosilicate polymer network is formed. This network consists of SiO 4 and AlO 4 tetrahedrons, which each are linked with other tetrahedrons via four corners.
Geopolymers can be used as binder in the construction material industry, in order to decrease the cement content or ensure faster hardening. Further advantages of geopolymers include the chemical resistance, temperature resistance, high final strength, high density and low permeability.
A multitude of solids such as metakaolin or also fly ash can be used as educts. The use of geopolymers as an alternative binder for concrete opens up the possibility of a new construction material. Its potential chiefly consists in the fact that during the production of classical cements, such as Portland cement, major amounts of the greenhouse gas carbon dioxide are released by the reaction:
CaCO 3 →CaO+CO 2 .
Geopolymers thus represent an alternative binder, which decrease the CO 2 emission and counteract the greenhouse effect.
Since the properties of geopolymers depend on their composition, different geopolymers are produced in practice depending on the requirements profile.
U.S. Pat. No. 4,472,199 for example describes a geopolymer from the silicoalumina family with the following composition: Potassium oxide to silicon oxide 0.3 to 0.38, silicon oxide to alumina 4.0 to 4.2, water to alumina 14 to 20, and potassium oxide to alumina 1.3 to 1.52. The geopolymer thus obtained shows a distinctly pronounced structure, which has ion exchange properties and accordingly can be used in a similar way as zeolites or molecular sieves.
From U.S. Pat. No. 4,509,985 however a polymer is known, which has the following compositions: M 2 O to silica 0.2 to 0.36, silica to alumina 3 to 4.12, water to M 2 O 12 to 20, and M 2 O to alumina 0.6 to 1.35, wherein the letter M can be representative for a member of the group including sodium oxide, potassium oxide or a mixture of sodium oxide and potassium oxide. The solid material thus produced is characterized by a particular early high strength.
While in these two documents the polymer is produced from a mixture of different silicates by adding an alkaline activator and water while stirring continuously and at a slightly elevated temperature, DE 691 05 958 T2 describes a process for producing an aluminosilicate geopolymer in which silicon dusts are used. These silicon dusts are obtained by condensation of silicon oxide vapors from the electrofusion at very high temperatures and have an amorphous structure.
All documents have in common that minerals with a defined composition are used as educts.
SUMMARY
In an embodiment, the present invention provides a process for producing a geopolymer. The process includes combusting at least one of oil shale and mineral residues originating from a production of oil using the oil shale so as to produce a combustion product. The combustion product is ground. An alkaline activator is added to the combustion product to form a geopolymer mixture. Water is added to the geopolymer mixture. The geopolymer mixture is adjusted so as to obtain a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41. The geopolymer mixture is hardened.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described in even greater detail below based on the exemplary FIGURE. The invention is not limited to the exemplary embodiment. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawing which illustrates the following:
FIG. 1 schematically shows a plant for performing the process in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
For further improvement of the ecobalance, the present invention recognizes it to be expedient to use a substance obtained as waste product of another process. Such substance, in an embodiment, is oil shale.
Oil shales are rocks containing bitumen and/or low-volatility oils, wherein the amount of bound organic components can be between 10 and 30% depending on the deposit. Oil shale is particularly useful as energy source and has a calorific value between 4 and 8 megajoule per kilogram, based on the raw substance.
Accordingly, in an embodiment, the present invention uses the residues left during the combustion of oil shale for the production of geopolymers.
In an embodiment, the present invention provides that the oil shale and/or also mineral residues, which originate from the production of oil by means of shale are burnt and subsequently ground, before they are mixed with an alkaline activator and water and cured. During use of the oil shale calcining residue in accordance with an embodiment of the invention, the oil shale calcining residue acts both as mineral component and as activator. The effect as activator is caused by calcium oxide, which must be formed during production of the calcining residue. In contrast to previous practice, a rather complete decarbonation of the calcium carbonate contained in the crude oil shale is desired in calcining processes, in order to maximize the yield of calcium oxide. When adding water at a later time, calcium oxide (CaO) reacts to form calcium hydroxide (Ca(OH) 2 ) which in turn acts as an alkali. In this way, the added amount of an alkaline activator, which is necessary for producing geopolymers, can be decreased and the production costs can be reduced.
Due to the comparatively high calorific value, large amounts of heat are released during combustion, which can be utilized for recovering energy. At the same time, the use of the remaining mineral residue (in particular semicoke, a substance which results from the incomplete carbonization of the oil shale and in terms of composition and structure ranges between coal and pitch) as educt for geopolymers represents a reasonable use of this waste product.
To allow replacement of the alkaline activator by potassium hydroxide for the most part, the calcium content in the oil shale is at least 10% in accordance with an embodiment of the invention.
A preferred embodiment of the invention furthermore provides for grinding the oil shale prior to combustion. To be able to ensure a uniform combustion, grinding should be effected to a mean grain size of <10 mm, preferably <5 mm, with a narrow grain range of e.g. ±0.5 mm being preferred.
In accordance with an embodiment of the invention, the combustion is performed at 850 to 1000° C., wherein a particularly favorable temperature range ranges between 900 and 950° C., as from about 900° C. the limestone contained in the oil shale is completely decarbonised.
To avoid undesired side reactions, the raw material is cooled after the combustion in accordance with an embodiment of the invention. Cooling screws or fluidized-bed coolers are particularly useful for this purpose.
Furthermore, beside the actual oil shale calcining residue the addition of further binders is recommendable for producing the geopolymer binder, which can be e.g. fly ashes or calcined clay. The properties of the material, such as the strength, thereby can be influenced once again. The addition of rocks of different grain sizes also is within the scope of an embodiment of the invention.
To achieve a high pH value required in accordance with an embodiment of the invention, and hence the polycondensation of the aluminosilicate polymers, the addition of an alkaline activator furthermore is necessary. Sodium hydroxide solution, potassium hydroxide solution, sodium waterglass (sodium silicate solution) or potassium waterglass (potassium silicate solution) are particularly useful as such alkaline activator, since the same are readily available alkaline additives.
Preferably, hardening of the material then takes place within less than 24 hours, particularly preferably within less than 6 hours.
It was furthermore found to be advantageous to adjust the mol ratio of silicon to aluminum in the geopolymer mixture to 2 to 5, the mol ratio of potassium to aluminum to 0.6 to 0.7, the mol ratio of silicon to potassium to 3 to 10, the mol ratio of calcium to aluminum to 0.1 to 0.4, and the mol ratio of silicon to calcium to 4.9 to 41. This is done by fine adjustment and thus provides a selective control of the application parameters of the geopolymer thus obtained.
An embodiment of the invention also comprises a geopolymer which has been produced by the process of an embodiment of the invention and has the mol ratio of silicon to aluminum of 2 to 5, the mol ratio of potassium to aluminum of 0.6 to 0.7, the mol ratio of silicon to potassium of 3 to 10, the mol ratio of calcium to aluminum of 0.1 to 0.4, and the mol ratio of silicon to calcium of 4.9 to 41.
According to the plant construction shown in FIG. 1 , the oil shale first is charged to a grinding mill 1 , in which it is comminuted to a grain size of less than 10 mm, e.g. 4-5 mm. Via conduit 2 , the oil shale thus ground is delivered into the furnace 3 . This furnace is preferably a fluidized-bed furnace, wherein at larger feed rates (>1000 tons per day) the use of a circulating fluidized bed is recommended. At temperatures above 900° C., a complete decarbonisation of the limestone contained in the oil shale takes place.
Via conduit 4 , the powder thus burnt is supplied to a cooling stage 5 . Cooling screws or fluidized-bed coolers are particularly preferred configurations. The powder cooled down to about 150° C. then is supplied to a further grinding mill 7 via conduit 6 . In this grinding mill 7 , the powder is ground to a grain size of less than 100 μm, before it then is supplied to the first mixing tank 9 via conduit 8 .
Further binders, e.g. fly ashes or calcined clay, can be admixed here via conduit 10 , before the mixture is transferred via conduit 11 into the mixing tank 12 , into which an activator solution is introduced via conduit 13 , which consists of one or more alkaline activator(s), e.g. NaOH, KOH, sodium waterglass (sodium silicate solution) or potassium waterglass (potassium silicate solution). Through conduit 14 , the mixture flows into the mixing tank 15 , where it is mixed with water from conduit 16 , in order to quench the CaO contained in the burnt oil shale residue and achieves the desired workability of the mixture. When adding water, hydrated lime (CaO+H 2 O→Ca(OH 2 )) is formed. The geopolymer has the following composition: Mol ratios Si:Al=2 to 5, K:Al=0.6 to 0.7, Si:K=3 to 10, Ca:Al=0.1 to 0.4, Si:Ca=4.9 to 41. In dependence on the raw materials, the exact composition of the geopolymer will be optimized depending on the application. It was noted that an amount of 8% calcium hydroxide in the geopolymer mixture has an advantageous influence on the development of strength.
Instead of an arrangement in three separate mixing tanks it is also conceivable to have all three supply conduits open into a single tank. A reversal of the individual mixing stages is also possible.
Through conduit 17 , the geopolymer mixture is delivered into a further tank 18 , in which the composition of the mixture is controlled via a measuring device 19 . Via conduit 20 , missing components can then be supplied. Alternatively, the composition of the geopolymer in accordance with an embodiment of the invention can be achieved by means of a measuring device, which controls the supply of binder, alkaline activator and/or water into the respective mixing tank(s).
Via conduit 21 , the mixture is finally delivered to harden in the hardening tank 22 , from which the geopolymer or geopolymer concrete component of an embodiment of the invention can be demoulded after a sufficient hardening time.
While the invention has been described with reference to particular embodiments thereof, it will be understood by those having ordinary skill the art that various changes may be made therein without departing from the scope and spirit of the invention. Further, the present invention is not limited to the embodiments described herein; reference should be had to the appended claims.
LIST OF REFERENCE NUMERALS
1 grinding mill
2 conduit
3 furnace
4 conduit
5 grinding mill
6 conduit
7 cooling device
8 conduit
9 mixing tank
10 conduit
11 conduit
12 mixing tank
13 conduit
14 conduit
15 mixing tank
16 conduit
17 conduit
18 mixing tank
19 measuring device
20 conduit
21 conduit
22 hardening tank | A process for producing a geopolymer includes combusting at least one of oil shale and mineral residues originating from a production of oil using the oil shale so as to produce a combustion product. The combustion product is ground. An alkaline activator is added to the combustion product to form a geopolymer mixture. Water is added to the geopolymer mixture. The geopolymer mixture is adjusted so as to obtain a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41. The geopolymer mixture is hardened. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2007-007675 filed in Japan on Jan. 17, 2007, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates to coating compositions based on water-soluble silicon-containing polymers, a method for preparing the same, and articles coated or surface treated therewith. More particularly, it relates to coating compositions based on water-soluble silicon-containing polymers containing a plurality of primary amino groups and a hydrolyzable silyl group and serving as a primer or modifier (for composites) with improved properties, a method for preparing the same, and articles coated or surface treated therewith.
BACKGROUND ART
[0003] In the prior art, composite materials are prepared by treating glass fiber preforms such as glass cloth, glass tape, glass mat, and glass paper and mica preforms serving as an inorganic reinforcement with organic resins such as epoxy resins, phenolic resins, polyimide resins and unsaturated polyester resins. These composite materials find use in a wide variety of applications.
[0004] Laminates are often made of such composite materials. It is desired to improve the mechanical strength, electrical properties, water resistance, boiling water resistance, chemical resistance, and weatherability of such laminates. It was proposed to pretreat the inorganic reinforcements with silane coupling agents such as γ-aminopropyltriethoxysilane, β-aminoethyl-γ-aminopropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane, prior to the treatment with organic resins. This pretreatment enhances the adhesion of resins to the inorganic reinforcements.
[0005] Among others, those composite materials using phenolic resins as the organic resin have excellent heat resistance, dimensional stability and moldability and have long been used as the molding material in the basic industrial fields including automobiles, electric and electronic equipment. Under the recent trend aiming at reduced cost and weight, active attempts have been made to replace metal parts by high-strength molded parts of glass fiber-reinforced phenolic resins. In order to promote metal replacement in the future, the key is to achieve a high strength which has never been reached by prior art glass fiber-reinforced phenolic resin moldings. To achieve a high strength, many techniques of treating glass fibers with amino-silane coupling agents to enhance the adhesion to the matrix resin have been proposed. The treatment with coupling agents alone, however, encounters certain limits in enhancing strength. Under the circumstances, several techniques have been proposed for further improving the adhesion between glass fibers and matrix resins.
[0006] JP-A 52-12278 discloses that glass fibers to be admixed with a thermosetting resin are pretreated by applying a primer resin compatible with the thermosetting resin or a mixture of the primer resin and another primer agent such as a silane coupling agent closely to surfaces of glass fibers. It is described that high strength is achieved by dispersing the pretreated fibers in the thermosetting resin. This technique, however, exerts a rather little effect of enhancing the strength of molding material and is uneconomical because autoclave treatment is necessary at the stage when glass fibers are pretreated. For a diallyl phthalate polymer matrix, glass fibers pretreated with a diallyl phthalate polymer and a silane coupling agent are used. The disclosure thus refers to only the strength enhancement effect due to reaction and interaction between these diallyl phthalate resins, but nowhere to phenolic resin molding materials.
[0007] JP-A 10-7883 discloses a technique of producing a phenolic resin composition with improved rotational rupture strength by first sizing glass fibers with a phenolic resin of the same type as a matrix phenolic resin, then treating them with a coupling agent, and incorporating the treated glass fibers in a phenolic resin composition. With this technique, however, surfaces of glass fibers are directly treated with the phenolic resin. Since the phenolic resin generally has weak chemical bonding forces with glass fibers, a firm adhesion is not available between the fibers and the matrix resin. This technique is thus less effective in enhancing the strength of molding material.
[0008] In connection with the above technique, JP-A 2001-270974 discloses a technique of improving the mechanical strength of a phenolic resin composition at normal and elevated temperatures by treating glass fibers with a phenolic resin of the same type as a matrix phenolic resin and an amino-silane coupling agent at the same time, or treating with an amino-silane coupling agent and then with a phenolic resin of the same type as a matrix phenolic resin, and incorporating the treated fibers in a phenolic resin composition. The amino-silane coupling agent used herein has one or two primary amino and secondary amino groups per hydrolyzable silyl group. The degree of bond between the coupling agent with which glass fibers are treated and the phenolic resin is not sufficient. Then the coupling agent is regarded to be a factor of reducing the strength of the resin composition.
DISCLOSURE OF THE INVENTION
[0009] An object of the invention is to provide a coating composition featuring a high water solubility and good adhesion to inorganic materials and organic resins, and serving as a primer or modifier for improving many properties including mechanical strength, water and boiling water resistance and weatherability, a method for preparing the composition, and an article coated or surface treated with the composition.
[0010] The inventor has found that when a coating composition based on a water-soluble silicon-containing polymer containing a silyl group capable of reaction with an inorganic material to form a chemical bond and a plurality of amino groups capable of reaction with an organic resin to form chemical bonds is used as a primer or modifier for composites, an increased number of reaction sites with an organic resin are available as compared with prior art amino-silane coupling agents, which facilitate to increase a bond strength to the organic resin, resulting in improved adhesion.
[0011] In a first aspect, the invention provides a coating composition comprising a water-soluble silicon-containing polymer comprising recurring units having the general formula (1):
[0000]
[0000] wherein m is a number from 10 to 260, n is a number from 1 to 100, R 1 is hydrogen, a C 1 -C 4 alkyl group or acetyl group, and “a” and “b” each are an integer of 1 to 3, X is a C 1 -C 10 alkylene chain which may be substituted with a C 1 -C 6 alkyl group, Y is a single bond, oxygen atom or CHR 5 group, R 2 , R 3 , R 4 and R 5 each are hydrogen or a C 1 -C 6 alkyl group, R 3 or R 4 may bond with R 5 to form a saturated carbon ring, said polymer having a plurality of primary amino groups and a hydrolyzable silyl or silanol group or both, and an organic solvent or water or both.
[0012] In a second aspect, the invention provides a method for preparing a coating composition comprising a water-soluble silicon-containing polymer comprising recurring units having formula (1) and containing a plurality of primary amino groups and a hydrolyzable silyl or silanol group or both, and an alcohol or water or both, the method comprising the step of reacting a water-soluble primary amino group-containing polymer having the general formula (3):
[0000]
[0000] wherein m and n are as defined above, with an epoxy group-containing silicon compound having the general formula (2):
[0000]
[0000] wherein R 1 to R 4 , a, b, X, and Y are as defined above, in an alcohol and/or water.
[0013] In preferred embodiments of the first and second aspects, m and n in formula (1) are numbers in the range: 0.003≦n/(m+n)≦0.9; and the water-soluble silicon-containing polymer has a weight average molecular weight of 300 to 3,000.
[0014] In a third aspect, the invention provides an article comprising a substrate which is coated or surface treated with the coating composition of the first aspect. The substrate is typically a glass fiber item selected from among glass cloth, glass tape, glass mat, and glass paper, an inorganic filler, a ceramic, or a metal.
BENEFITS OF THE INVENTION
[0015] The coating composition of the invention is based on the water-soluble silicon-containing polymer containing a plurality of primary amino groups per hydrolyzable silyl group in its molecule. The polymer offers an increased number of reaction sites with organic resins and hence stronger bonding forces thereto, as compared with prior art amino-silane coupling agents. The coating composition then develops improved adhesion when it is used as a primer and specifically as a modifier for composite materials.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The notation (Cn-Cm) means a group containing from n to m carbon atoms per group. The term “polymer” refers to high-molecular-weight compounds.
[0017] The coating composition of the invention is based on a water-soluble silicon-containing polymer having the general formula (1).
[0000]
[0018] Herein m is a number from 10 to 260, n is a number from 1 to 100, R 1 is a hydrogen atom, a C 1 -C 4 alkyl group or an acetyl group, and “a” and “b” each are an integer of 1 to 3, X is a C 1 -C 10 alkylene chain which may be substituted with a C 1 -C 6 alkyl group, and Y is a single bond, an oxygen atom or a CHR 5 group. R 2 , R 3 , R 4 and R 5 each are a hydrogen atom or a C 1 -C 6 alkyl group. R 3 or R 4 may bond with R 5 to form a saturated carbon ring.
[0019] In formula (1), R 1 is a hydrogen atom, a C 1 -C 4 alkyl group such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, or acetyl group. Each of R 2 to R 5 is a hydrogen atom or a C 1 -C 6 alkyl group such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl, isopentyl or hexyl. R 3 or R 4 may bond with R 5 to form a saturated carbon ring such as cyclopentyl or cyclohexyl.
[0020] X is selected from straight, branched or cyclic C 1 -C 10 alkylene chains, which are optionally substituted, such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, 1,4-cyclohexylene, 1,2-cyclohexylene, 1,3-cyclopentylene, 1,4-cyclooctylene, and 1,4-cyclohexanedimethylene. When substituted, the substituent groups are C 1 -C 6 alkyl groups, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl, isopentyl, and hexyl.
[0021] The subscripts m and n are numbers in the range: 10≦m≦260 and 1≦n≦100, preferably 10≦m≦100 and 1≦n≦80, and more preferably 10≦m≦75 and 1≦n≦50. Also preferably m and n satisfy the range: 0.003≦n/(m+n)≦0.9, and more preferably 0.06≦n/(m+n)≦0.5. The inclusion of a plurality of amino groups per silyl group is preferred.
[0022] The water-soluble silicon-containing polymer has a plurality of primary amino groups, and is present in such a state that some amino groups within its molecular structure have reacted with a silane coupling agent to form bonds. Specifically, in an embodiment wherein a silane coupling agent having an epoxy group is used, the epoxy group undergoes ring opening to form a structure being bonded to the nitrogen atom of an amino group. The aforementioned reaction of an amino group with a silane coupling agent may be carried out either prior to or subsequent to polymer formation. Namely, by reacting a water-soluble polymer having a plurality of primary amino groups with a silane coupling agent, a hydrolyzable silyl group may be introduced into that polymer. Alternatively, a water-soluble polymer having a hydrolyzable silyl group introduced therein may be obtained by reacting an amino compound having a primary amino group with a silane coupling agent, then effecting polymerization or polycondensation reaction.
[0023] While the silane coupling agent capable of reacting with a primary amino group to form a bond is used for introducing a hydrolyzable silyl group into the water-soluble silicon-containing polymer according to the invention, exemplary silane coupling agents include epoxy-bearing silicon compounds having the general formula (2).
[0000]
[0000] Note that R 1 to R 4 , X, Y, a and b are as defined above.
[0024] Examples of suitable silicon compounds include, but are not limited to, glycidoxymethyltrimethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethyldimethylmethoxysilane, glycidoxymethyltriethoxysilane, glycidoxymethylmethyldiethoxysilane, glycidoxymethyldimethylethoxysilane, 3-glycidoxy-2-methylpropyltrimethoxysilane, 3-glycidoxy-2-methylpropylmethyldimethoxysilane, 3-glycidoxy-2-methylpropyldimethylmethoxysilane, 3-glycidoxy-2-methylpropyltriethoxysilane, 3-glycidoxy-2-methylpropylmethyldiethoxysilane, 3-glycidoxy-2-methylpropyldimethylethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These silicon compounds may be used alone or in admixture.
[0025] The water-soluble polymer having primary amino groups which is a precursor resin to the water-soluble silicon-containing polymer includes a polyallylamine obtained through homopolymerization of an allylamine which is a polymerizable monomer having a primary amino group. Other vinyl monomers may be polymerized together insofar as this does not interfere with water solubility.
[0026] Preferred is a water-soluble polymer having primary amino groups represented by the general formula (3):
[0000]
[0000] wherein m and n are as defined above.
[0027] In a preferred embodiment, a water-soluble polymer having primary amino groups represented by formula (3) is reacted with an epoxy-containing silicon compound of formula (2) in an alcohol and/or water.
[0028] Examples of the alcohol used herein include lower alcohols of 1 to 4 carbon atoms, such as methanol, ethanol, isopropanol, and butanol, with methanol and ethanol being preferred. The alcohol and/or water is preferably used in such amounts that the reaction mixture has a nonvolatile concentration of 20 to 50% by weight. Where alcohol and water are used in admixture, the preferred mixture contains 1 part by weight of water and 7 to 9 parts by weight of alcohol.
[0029] Referring back to formula (1), the subscripts m and n stand for the number of allylamine units and the number of units resulting from reaction of allylamine with silane in the molecule, respectively. A ratio of m to n represents a ratio of primary amino groups to silyl groups in the molecule. If 260<m or 100<n, which indicates a higher molecular weight, then such a polymer cannot be manufactured consistently because it reaches a very high viscosity at the synthesis stage. If m<10, and especially m=0, then acceptable water solubility is not available. If n<1, then a polymer lacks adhesion to inorganic materials.
[0030] Whatever is the silane coupling agent to be reacted with the polyallylamine precursor resin, the water-soluble silicon-containing polymer should preferably satisfy the range: 0.003≦n/(m+n)≦0.9, and more preferably 0.06≦n/(m+n)≦0.5 wherein n/(m+n) represents a ratio of the quantity (n) of silyl groups introduced to the quantity (m) of residual amino groups. If n/(m+n) is smaller than the range, then a polymer may lack adhesion to inorganic materials. If n/(m+n) is larger than the range, then a polymer may lack water solubility. It is then recommended that the polymer of formula (3) and the silicon compound of formula (2) be selected and used so that m and n may satisfy the above range.
[0031] The reaction temperature is generally up to 100° C., and preferably 25° C. to 70° C. The reaction time, which may vary over a wide range, is generally 1 to 100 hours, and preferably 2 to 50 hours.
[0032] Preferably, the water-soluble silicon-containing polymer has a weight average molecular weight (Mw) of 300 to 3,000, and more preferably 1,000 to 2,000, as determined by gel permeation chromatography (GPC) versus polystyrene standards. If Mw is greater than 3,000, then a polymer may be prone to gel and thus be difficult to manufacture and hold in shelf. If Mw is less than 300, then polymer synthesis is difficult because of uncontrollable polymerization.
[0033] The coating composition further contains an organic solvent or water or both. Typically, the coating composition contains 10 to 95%, and preferably 20 to 90% by weight of the solvent and/or water and the balance of the silicon-containing polymer. Preferred solvents are lower alcohols such as methanol and ethanol
[0034] Since the coating composition is based on the water-soluble silicon-containing polymer having silyl groups capable of reaction with an inorganic material to form chemical bonds and amino groups capable of reaction with an organic resin to form chemical bonds, it is advantageously used as a primer, or a modifier for a composite material having an inorganic material combined with an organic resin.
[0035] The substrates to be coated or surface treated with the coating composition of the invention include inorganic materials which are generally reactive with hydrolyzable silyl groups to form bonds and organic resins which are generally reactive with amino groups to form bonds. The shape of substrates is not particularly limited. Typical examples of inorganic materials include inorganic fillers such as silica, glass fibers and fiber glass items such as glass cloth, glass tape, glass mat and glass paper, ceramics, and metal substrates such as iron, aluminum, copper, silver, gold, and magnesium. Typical examples of organic resins include epoxy resins, phenolic resins, polyimide resins, and unsaturated polyester resins. The substrates are not limited to the illustrated examples.
[0036] The technique of coating or surface treating substrates with the coating composition of the invention is not particularly limited. Typical coating or surface treating techniques are flow coating, dipping, and spin coating. The conditions of subsequent curing are not particularly limited. Typical curing conditions include heating and drying. After treatment, the coating is preferably heated and dried at 60 to 180° C., preferably 80 to 150° C. for 5 minutes to 2 hours, to facilitate simultaneously removal of the solvent and chemical reaction of the base polymer in the coating composition with the substrate surface.
Example
[0037] Examples of the invention are given below by way of illustration and not by way of limitation. All parts are by weight. In Examples, pH is a measurement at 25° C. The viscosity is measured at 25° C. by a Brookfield rotational viscometer. The abbreviation GC is gas chromatography, NMR is nuclear magnetic resonance spectroscopy, and Mw is a weight average molecular weight as determined by gel permeation chromatography (GPC) versus polystyrene standards.
Example 1
[0038] Solvent exchange was carried out on 500.0 parts of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-01, Mw=1000) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 77.9 parts (0.33 mole) of 3-glycidoxypropyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 3-glycidoxypropyltrimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 3-glycidoxypropyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 3-glycidoxypropyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15% by weight of the active ingredient, obtaining a primer composition. This composition was a clear yellow solution which was quickly miscible with water and had pH 11.7 and a viscosity of 2.7 mPa-s. The base polymer portion had a degree of polymerization of about 17 and the following average structural formula.
[0000]
Example 2
[0039] Solvent exchange was carried out on 500.0 parts of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-01, Mw=1000) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 40.1 parts (0.17 mole) of 3-glycidoxypropyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 3-glycidoxypropyltrimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 3-glycidoxypropyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 3-glycidoxypropyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15% by weight of the active ingredient, obtaining a primer composition. This composition was a clear yellow solution which was quickly miscible with water and had pH 11.4 and a viscosity of 2.1 mPa-s. The base polymer portion had a degree of polymerization of about 17 and the following average structural formula.
[0000]
Example 3
[0040] Solvent exchange was carried out on 500.0 parts of a 20 wt % aqueous solution of polyallylamine (Mw=700) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 96.8 parts (0.42 mole) of 3-glycidoxypropyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 3-glycidoxypropyltrimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 3-glycidoxypropyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 3-glycidoxypropyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15% by weight of the active ingredient, obtaining a primer composition. This composition was a clear yellow solution which was quickly miscible with water and had pH 11.8 and a viscosity of 2.3 mPa-s. The base polymer portion had a degree of polymerization of about 12 and the following average structural formula.
[0000]
Example 4
[0041] Solvent exchange was carried out on 500.0 parts of a 20 wt % aqueous solution of polyallylamine (Mw=2500) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 96.8 parts (0.42 mole) of 3-glycidoxypropyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 3-glycidoxypropyltrimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 3-glycidoxypropyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 3-glycidoxypropyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15% by weight of the active ingredient, obtaining a primer composition. This composition was a clear yellow solution which was quickly miscible with water and had pH 12.0 and a viscosity of 14.8 mPa-s. The base polymer portion had a degree of polymerization of about 44 and the following average structural formula.
[0000]
Example 5
[0042] Solvent exchange was carried out on 500.0 parts of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-01, Mw=1000) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 81.2 parts (0.33 mole) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15% by weight of the active ingredient, obtaining a primer composition. This composition was a clear yellow solution which was quickly miscible with water and had pH 11.5 and a viscosity of 3.5 mPa-s. The base polymer portion had a degree of polymerization of about 17 and the following average structural formula.
[0000]
Comparative Example 1
[0043] Water was removed from 500.0 parts of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-15, Mw=25,000, m+n>360 in formula (3)) by vacuum distillation. The solution increased its viscosity as the amount of water decreased. Finally, the solution became quite difficult to handle, and water removal was no longer possible. Methanol was added to dissolve the solids, obtaining a mixed solution of 15 wt % methanol and water. 77.9 parts (0.33 mole) of 3-glycidoxypropyltrimethoxysilane was added to this solution whereupon the silane gelled. Synthesis could no longer continue.
Comparative Example 2
[0044] Solvent exchange was carried out on 500.0 parts of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-01, Mw=1000) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution. The solution, to which 309.2 parts (1.31 moles) of 3-glycidoxypropyltrimethoxysilane was added, was stirred at 60-70° C. for 5 hours. With the progress of reaction, the reactant, 3-glycidoxypropyltrimethoxysilane was consumed. The reaction solution was then analyzed by GC, but no peaks of the reactant, 3-glycidoxypropyltrimethoxysilane were detected. On NMR analysis of silicon, there were observed no signals of 3-glycidoxypropyltrimethoxysilane and instead, signals probably attributable to a target compound were observed. The completion of reaction was identified by these measurements. The solution was diluted with methanol to a concentration of 15 wt % of the active ingredient, obtaining a primer composition. It had pH 11.9 and a viscosity of 3.5 mPa-s. The base polymer portion had a degree of polymerization of about 17 and the following average structural formula.
[0000]
[0045] This solution, however, was less water soluble because it turned white turbid when mixed with water.
Comparative Example 3
[0046] A primer composition was prepared by diluting 3-aminopropyltrimethoxysilane with methanol to a concentration of 15 wt %.
Comparative Example 4
[0047] Solvent exchange was carried out on 500.0 parts (0.075 mole of polyallylamine with a molecular weight of 1,000) of a 15 wt % aqueous solution of polyallylamine (Nitto Boseki Co., Ltd, PAA-01, Mw=1000) by removing water under reduced pressure and adding methanol instead. It turned to a 15 wt % methanol solution, which was used as a primer composition.
[Preparation of Polyurethane Elastomer for Adhesion Test]
[0048] 150 parts of polyoxytetramethylene glycol with a molecular weight of 1,000, 100 parts of 1,6-xylene glycol, 0.5 part of water, 200 parts of hexamethylene diisocyanate, and 800 parts of dimethylformamide were mixed by agitation, and heated at 90° C. The mixture was agitated at the temperature for a further 2 hours, allowing the reaction to run. The reaction was stopped by adding 3 parts of dibutyl amine. The excess of amine was neutralized with acetic anhydride, yielding a polyurethane elastomer.
[Adhesion Test of Primer]
[0049] Each of the primer compositions obtained in Examples and Comparative Examples was brush coated to glass, steel and aluminum plates, and dried at 120° C. for 5 minutes. The polyurethane elastomer was brush coated thereon and dried at 100° C. for 10 minutes. The coating was subjected to a crosshatch adhesion test by scribing the coating in orthogonal directions at intervals of 1 mm to define 100 sections, attaching a pressure-sensitive adhesive tape to the coating, and stripping the tape. The number of stripped coating sections was counted, based on which the adhesion of primer to the urethane resin and the inorganic substrate was evaluated. For all the primer compositions of Examples, the number of stripped sections was zero, when applied to the three substrates. Superior adhesion performance was demonstrated.
[Water Solubility Test of Primer]
[0050] Each of the primer compositions obtained in Examples and Comparative Examples was held for about 10 hours in a 10 wt % aqueous solution form. Then the solution was visually observed for turbidity due to insoluble matter, precipitation, and layer separation. In terms of these factors combined, it was rated good (◯), fair (Δ) or poor (x).
[0051] The results of the adhesion test and water solubility test on the compositions of Examples and Comparative Examples are shown in Table 1.
[0000]
TABLE 1
Adhesion
Glass
Steel
Aluminum
Water
plate
plate
plate
solubility
Example 1
100/100
100/100
100/100
◯
Example 2
100/100
100/100
100/100
◯
Example 3
100/100
100/100
100/100
◯
Example 4
100/100
100/100
100/100
◯
Example 5
100/100
100/100
100/100
◯
Comparative Example 2
72/100
60/100
63/100
Δ
Comparative Example 3
94/100
95/100
90/100
◯
Comparative Example 4
73/100
53/100
48/100
◯
[0052] It is proven from the data of Examples and Comparative Examples that better results of adhesion are accomplished by the primer composition of the invention.
[0053] Japanese Patent Application No. 2007-007675 is incorporated herein by reference.
[0054] Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims. | A coating composition is based on a water-soluble silicon-containing polymer containing a silyl group capable of reaction with an inorganic material to form a chemical bond and a plurality of amino groups capable of reaction with an organic resin to form chemical bonds. This coating composition has a water solubility and adhesion to inorganic materials and organic resins, and serves as a primer or modifier for improving many properties including mechanical strength, water and boiling water resistance and weatherability. | 2 |
BACKGROUND
1. The Field of the Invention
The present invention relates to explosives, and more particularly, to dry explosives for use in developing surface seismic shock energy.
2. The Prior Art
Surface seismic shock explosives have been widely accepted as a preferred means of inducing shock waves into the earth. The shock waves, according to known techniques, are reflected by subsurface geological strata and detected again at or near the surface of the earth using detectors, such as geophones. Analysis of the reflected shock waves permits skilled analysts to gain valuable geological information which, among other uses, assists in the discovery of subsurface gas and oil.
The explosive composition which is used to induce the shock wave into the earth must develop the necessary shock energy, while at the same time permit safe and facile handling. Several prior art products have been developed to address these characteristics. Examples of such prior art products are "Thermex, " sold by Thermex Energy Corporation, and "Surf-a-seis," sold by Hercules, Incorporated.
Prior art compositions of dry explosive are typically packaged in a flexible plastic bag which is suspended upon a ground stake and tied with high grain (25 to 30 grains of PETN per foot) detonating cord. The detonating cord initiates the seismic explosive, which in turn generates the shock wave.
Typically, seismic explosives are used in field environments which give rise to serious concern about fire. In the typical circumstance, plastic containers of seismic explosives are placed on wooden stakes and spaced in an array at a site to be tested. It is not uncommon for the site to be covered with dry grass and foliage which creates a serious fire hazard when seismic explosives are used. One contributor to the fire hazard is the high grain detonating cord which is required to initiate many of the prior art seismic compositions.
To minimize the fire hazard, some prior art products are sold with a pouch of fire retardant to be placed on the positioning stake below the explosive prior to initiation. When the explosive shoots, the retardant is designed to quench any fire which is ignited. The retardant, however, increases the cost and the complexity of seismic exploration.
The prior art compositions each use an oxidizer and a fuel mixed together with a sensitizer, such as finely divided aluminum. However, finely divided (paint grade) aluminum is expensive and cannot be used alone reliably so as to be both safe in handling and reliable in initiating. Accordingly, prior art compositions typically include a Nitroparaffin sensitizer, such as 1-Nitropropane, which are liquids with high vapor pressures. When carefully mixed with the dry fuel and oxidizers, Nitroparaffins can effectively increase the sensitivity.
Liquid Nitroparaffins, however, used in the prior art compositions disadvantageously tend to vaporize under higher temperature conditions, thereby causing the plastic bag containing the composition to swell. Thus, special care and expense must be invested in each packaging bag to assure that margins and openings are sealed against the increased vapor pressure inside the bags. Unless the bag is specially sealed, it will rupture and the Nitroparaffin will evaporate.
It would, therefore, be a significant imporvement in the art to provide a dry surface seismic composition which reliably initiates with lower grain detonating cord and which is also safe and easy to handle without the attendant problems presented by the prior art compositions. Such an explosive composition is disclosed and claimed herein.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
The present invention is directed to novel dry explosive compositions which can be initiated by standard detonating cords of the low grain variety, but which are also safe and easy to handle.
Preferred embodiments of the present invention are dry explosive compositions of the present invention which include a Hexamine sensitizer. The resultant compositions control sensitivity without the use of liquid sensitizers which tend to vaporize and swell the packaging bags.
It is, therefore, a primary object of the present invention to provide an improved, dry, seismic explosive composition.
A further primary object of the invention is to provide a seismic explosive which can be initiated by low grain detonation cord so as to reduce fire hazard typically associated with high grain detonation cord.
Another important object is to provide a seismic explosive admixture having controlled sensitivity with superior safety and handling characteristics.
It is another important object of the present invention to provide a dry seismic explosive which will not become desensitized over a wide temperature range.
A still further object is to provide a dry seismic explosive admixture which does not vaporize to swell the bags containing the mixture.
These and other objects and features of the invention will become more fully apparent from the following description and appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention include at least one oxidizer, at least one fuel, and a unique mixture of dry sensitizers which can be selected to safely permit initiation of the composition with low grain (12 and less) detonating cord.
As an oxidizer, Ammonium Nitrate is preferred, because it is inexpensive and readily available. The Ammonium Nitrate is supplemented with another suitable nitrate such as Potassium Nitrate, Sodium Nitrate or Lead Nitrate which improves overall oxidation capacity and acts as a physical barrier to aid in minimizing caking of the Ammonium Nitrate. Sodium Nitrate has also been found to be an acceptable oxidizer. The oxidizers are ground to approximately 100 mesh and mixed together.
Any one of a variety of fuels may be added to the oxidizer mix. Granular aluminum and Gilsonite have been found to be effective. Other suitable fuels include coal dust, cellulose materials from a variety of origins; even sugar has been found to be acceptable for many situations. The amount of fuel may vary depending upon the stoichiometry of the total composition, but the amount of fuel in the composition is typically in the range of from about 1% to about 10% by weight.
In the embodiment described herein, it has been found desirable to add a small amount of fumed silica to minimize crystallization and caking of the Ammonium Nitrate. Commercially available silica sold under the trade names "Cab-o-Sil" and "Aerosil" are suitable for use in the present invention. Silica added in an amount up to about 0.3% will maintain the Ammonium Nitrate in a fine-dry powdered form, without adversely affecting sensitivity.
The sensitivity of the oxidizer/fuel mixture is improved with Hexamine, or a selected derivative thereof, in amounts in the range of from about 5% to about 8%. When the Hexamine is dispersed throughout the dry mix, the resulting composition was found to be safe and effective; equally important, the resulting composition can be reliably initiated with a number 8 blasting cap.
Desirably, a fire retardant may be incorporated into the composition to absorb energy and decrease the temperature of the explosive reaction. Sodium Chloride and phosphates have been found to be effective when used in concentrations of about 1% to 25%.
This composition, however, requires additional sensitization in order for initiation to be achieved with a low grain detonating cord. Increased sensitivity is accomplished by adding a small amount of finely divided (paint grade) aluminum in sufficient amounts that the composition will initiate with a 71/2 to 12 grain detonating cord.
The following examples illustrate the invention:
EXAMPLE 1
A composition within the scope of the present invention was prepared by thoroughly mixing the following ingredients in the indicated corresponding amounts:
______________________________________Ingredient Percent Composition______________________________________Ammonium Nitrate 80%Potassium Nitrate 10%Aerosil 0.2%Hexamine 6.3%Paint Grade Aluminum 1.5%Gilsonite 2%______________________________________
This composition resulted in a dry mix of powder to fine granular consistency which resisted caking. When sealed in a plastic bag and exposed to temperatures up to 140° F., the composition resisted vaporization. No swelling of the packaging bag was noted, and no vaporization of the sensitizer could be detected. The composition initiated reliably with a 71/2 grain detonating cord.
EXAMPLE 2
Another composition within the scope of the present invention is made by mixing the following ingredients in the indicated corresponding amounts:
______________________________________Ingredient Percent Composition______________________________________Ammonium Nitrate 70%Potassium Nitrate 19%Hexamine 8%Paint Grade Aluminum 0.5%Gilsonite 2.5%______________________________________
The resulting composition is a dry mix in which caking is minimal. In addition, the composition resists vaporization under conditions such as those set forth in Example 1. The composition of this Example is capable of reliable initiation using a 25 grain detonating cord.
EXAMPLE 3
Another composition within the scope of the present invention is made by mixing the following ingredients in the indicated corresponding amounts:
______________________________________Ingredient Percent Composition______________________________________Ammonium Nitrate 89%Aerosil 0.3%Hexamine 5%Paint Grade Aluminum 3.0%Gilsonite 2.7%______________________________________
The resulting composition has essentially the same physical characteristics as the composition of Example 2, and it is capable of reliable initiation with a 71/2 grain detonating cord.
EXAMPLE 4
Another composition within the scope of the present invention is made by mixing the following ingredients in the indicated corresponding amounts:
______________________________________Ingredient Percent Composition______________________________________Ammonium Nitrate 89%Aerosil 0.3%Hexamine 6.7%Paint Grade Aluminum 1%Gilsonite 3.0%______________________________________
The resulting composition has essentially the same physical characteristics as the composition of Example 2, and it is capable of reliable initiation with an 18 grain detonating cord.
EXAMPLE 5
Other compositions within the scope of the present invention were made according to the procedures of Example 1, except that the percent composition of fuel was varied in the range of from about 1% to about 3%. The variance in the amount of fuel did not significantly adversely affect the shooting (initiation) characteristics of the compositions.
EXAMPLE 6
Another composition within the scope of the present invention was made according to the procedures of Example 1, except that a Hexamine derivative was utilized as the sensitizer. The derivative of Hexamine was prepared by adding dilute nitric acid to the Hexamine. The resulting Hexamethylenetetramine Mononitrate was substituted for the Hexamine in the composition of Example 1.
The resulting composition possessed the same advantageous physical characteristics as the composition in Example 1 and was initiated reliably with a 12 grain detonating cord.
EXAMPLE 7
A composition within the scope of the present invention was prepared by mixing the following components in the indicated amounts:
______________________________________Ingredient Parts Composition______________________________________Ammonium Nitrate 75Aerosil 0.2Hexamine 6.3Paint Grade Aluminum 1.5Gilsonite 2Sodium Chloride 25______________________________________
This composition initiates reliably with a 12 grain detonating cord and advantageously decreases the temperature of the reaction significantly over that resulting from initiation of the composition of Example 1.
EXAMPLE 8
The composition of Example 1 was modified to substitute Lead Nitrate for the Potassium Nitrate. The composition initiated with a 12 grain detonating cord.
EXAMPLE 9
The composition of Example 1 was modified to substitute Sodium Nitrate for the Potassium Nitrate. The composition initiated with a 12 grain detonating cord.
The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A dry explosive seismic composition which can be initiated by low grain detonating cord so as to minimize the fire hazards typically associated with seismic testing. Preferred compositions within the scope of the present invention include a sensitizer of Hexamine or a derivative thereof, such as Hexamethylenetetramine Mononitrate. The compositions of the present invention not only reduce the fire hazards associated with using such compositions, but they also resist vaporization of the sensitizer, thereby minimizing the problems associated with handling the compositions. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a multi-band antenna, and more particularly to a multi-band antenna used for electronic devices, such as notebooks.
2. Description of the Prior Art
With the high-speed development of the mobile communication, people more and more expect to use a computer or other portable terminals to optionally connect to Internet. GPRS (General Packer Radio Service) and WLAN (Wireless Local Area Network) allow users to access data wirelessly over both cellular networks and 802.11b WLAN system. When operating in GPRS, the data transmitting speed is up to 30 Kbps˜50 Kbps, while when connected to a WLAN access point, the data transmitting speed is up to 11 Mbps. People can select different PC cards and cooperate with the portable terminals such as the notebook computer or the like to optionally connect to Internet. Since WLAN has a higher transmitting speed, WLAN is usually used to provide public WLAN high-speed data services in some hot areas (for example, hotel, airport, coffee bar, commerce heartland, conference heartland and etc.). When leaving from these hot areas, network connection is automatically switched to GPRS.
As it is known to all, an antenna plays an important role in wireless communication. As a result, the PC card may choose individual antennas to respectively operate at WWAN (Wireless Wide Area Network), namely GPRS, and WLAN. It arises a hot problem to integrate two individual antennas in a limited space to go along with the miniaturization of portal devices. Please refer to FIG. 1 , a multi-band antenna 10 ′ comprises a first type of antenna which is used in WWAN and has first and second antennas 1 ′, 2 ′ and a second type of antenna which is used in WLAN and has third and fourth antennas 3 ′, 4 ′. The multi-band antenna 10 ′ is integrally made from a metal sheet and integrates the first type of antenna for WWAN and the second type antenna for WLAN together. However, with the two types of antennas integration, the interference therebetween will become greater, and owing to this structure, the multi-band antenna 10 ′ can not achieve desired bandwidth. TW pat. No. 253070 discloses a wide band antenna. As shown in FIG. 2 of TW Pat. No. 253070, the wide band antenna has a gap 30 formed by cutting the radiating portion 24 of the antenna and an inductance is soldered on the position of the gap 30 , so that the radiating portion 24 of the antenna become an integer. However, the method of soldering a reactance on an antenna is difficult to achieve except the antenna is arranged on a PCB. In present removable devices, one most popular antenna, PIFA antenna for short, is used widely. Because of the lack of the supporting from a PCB, said means of assembling a reactance don't conform to this kind of antenna.
Hence, an improved antenna is desired to overcome the above-mentioned shortcomings of the existing antennas.
BRIEF SUMMARY OF THE INVENTION
A primary object, therefore, of the present invention is to provide a multi-band antenna used in WWAN and WLAN with simple structure to achieve a good impedance, and the antenna has low cost and easy manufacture.
In order to implement the above object and overcomes the above-identified deficiencies in the prior art, the multi-band antenna comprises a radiating element having at least two frequency bands and comprising a gap on one side edge thereof, a grounding element, a reactance, wherein the reactance is assembled on said gap to be received in.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a conventional multi-band antenna;
FIG. 2 is a perspective view of a multi-band antenna according to a preferred embodiment of the present invention;
FIG. 3 is a view similar to FIG. 2 , but take from a different aspect;
FIG. 4 is an exploded, perspective view of the multi-band antenna of FIG. 3 ; and
FIG. 5 is a test chart recording of Voltage Standing Wave Ratio (VSWR) of the multi-band antenna with reactance and without reactance as a function of frequency.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to a preferred embodiment of the present invention.
Reference to FIG. 2 to FIG. 4 , a perspective view of a multi-band antenna 1 in accordance with a preferred embodiment of the present invention is shown. The multi-band antenna 1 consists of an antenna body 100 , an insulative member 200 affixed to the antenna body 100 , a metal foil 300 and a reactance 400 soldered on the antenna body 100 . The multi-band antenna 1 also comprises a first antenna 2 used in WWAN, a second antenna 3 used in WLAN, a grounding element 6 integrally formed with the first antenna 2 and the second antenna 3 , and a pair of fitting elements 4 , 5 for mounting the multi-band antenna 1 to an electronic device. In this embodiment, the insulative member 200 , the metal foil 300 and the reactance 400 are all on the first antenna 2 . The antenna body 100 of the multi-band antenna 1 is made of a metal patch with a pressing means, which combine a WWAN antenna and a WLAN antenna. The grounding element 6 comprises a first grounding portion 61 , an L-shape metal patch 62 extending upwardly from the middle area of the first grounding portion 61 , and a metal patch 63 with interrupted shape.
The first antenna 2 comprises a radiating element 21 , a grounding element 6 , a connecting portion 22 connecting the radiating element 21 and the grounding element 6 and a protrusion 23 extending from the connecting portion 22 to connect a feeding line (not shown). The radiating element 21 is separated from and parallel to the grounding element 6 , and the radiating element 21 and are located on the same side of the connecting portion 22 . The radiating element 21 comprises a high-frequency radiating portion 210 and a low-frequency radiating portion 212 . The high-frequency radiating portion 210 comprises a first radiating arm 2101 having a triangle-shape notch 2101 a and a second radiating arm 2102 bending from the first radiating arm 2101 to the grounding element 6 . The low-frequency radiating portion 212 is a metal patch with interrupted shape like an “L”. The low-frequency radiating portion 212 comprises a first end 2120 connecting with the high-frequency radiating portion 210 and a second end 2122 opposite to the first end 2120 with a narrower width than that of the first end 2120 . A gap 2121 is defined by the first end 2120 by cutting itself on one side thereof to receive the reactance 400 . The insulative member 200 and the metal foil 300 are plastered to the second end 2122 . In this embodiment, the insulative member 200 comprises a rectangle main body 201 , a rib 202 extending from the joint of the upper surface 201 a and the side 201 c of the main body 201 , and a bar 203 extending from the joint of the lower surface 201 b and the side 201 c of the main body 201 . The side 201 c , the rib 202 and the bar 203 constitute a cavity (not labeled). The upper surface 201 a of the main body 201 is plastered on the surface, opposite to the grounding element 6 , of the low-frequency radiating portion 212 of the first antenna 2 . The side 201 c is adjacent to the second antenna 3 . The second antenna 3 is partially received in the cavity defined by the upper surface 201 a , the rib 202 and the bar 203 . The metal foil 300 is inverted-U shape, and plastered to the low-frequency radiating portion 202 to enclose the insulative member 200 . The metal foil 3 comprises an upper wall 301 , a lower wall 302 and a side wall 303 . The metal foil 300 opens toward the second antenna 3 . The upper wall 301 is fixed on the surface, facing to the grounding element 6 , of the first antenna 2 . The side wall 303 cover the side, opposite to the side 201 c , of the insulative member 200 . The lower wall 302 is plastered to the lower surface 201 b of the insulative member 200 . The metal foil 300 never touches the second antenna 3 . The metal foil 300 induces the area of the low-frequency radiating portion 212 of the second antenna rather than the length of the low-frequency radiating portion 212 , and then the band width of the low-frequency radiating portion 212 increases. To reduce the interference between the first antenna 2 and the second antenna 3 , a certain distance is needed therebetween. So the shape of the insulative member 200 is designed to fasten the first antenna 2 and the second antenna 3 together while still keeps the certain distance to reduce the interference between the first antenna 2 and the second antenna 3 . At the same time, the insulative member 200 supports the metal foil 300 . In alternative embodiment, the location site and shape of the insulative member 200 can be changed if needed. The reactance 400 locates in the gap 2121 of the low-frequency radiating portion 212 and defines a tinned area on its surface to solder itself on the low-frequency radiating portion 212 . The reactance 400 can be assembled on the other radiating portion, such as the high-frequency radiating portion 210 . The reactance 400 can be not only a Multi Layer Ceramic Capacitor but also a Multi Layer Ceramic Inductance. The protrusion 23 extends from a point M on the connecting portion 22 along the direction parallel to the grounding element 6 . The protrusion 23 is located on the same side of the connecting portion 22 same as the grounding element 6 .
The high-frequency radiating portion 210 is on a first plane same as the low-frequency radiating portion 212 of the first antenna 2 . The connecting portion 22 , extends from the joint of the high-frequency radiating portion 210 and the low-frequency radiating portion 212 , is Z shape and on a second plane perpendicular to the first plane. The connecting portion 22 connects the high-frequency radiating portion 210 and the low-frequency radiating portion 212 on a point Q. The gap 2121 of the low-frequency radiating portion 212 is adjacent to the point Q, while the triangle gap 2101 a is located on a side of the high-frequency radiating portion 210 opposite to the point Q.
The second antenna 3 comprises a radiating element 31 , a grounding element 6 , a connecting portion 32 connecting the radiating element 31 and the grounding element 6 , and a heave 33 connecting a feeding line (not shown). The radiating element 31 comprises a high-frequency radiating portion 310 , a low-frequency radiating portion 312 , a third radiating portion 314 and a common arm 3102 shared by the high-frequency radiating portion 310 and the low-frequency radiating portion 312 together. The common arm 3102 is perpendicular to the high-frequency radiating portion 310 and the low-frequency radiating portion 312 . The high-frequency radiating portion 310 also comprises a lengthwise radiating arm 3101 , and the low-frequency radiating portion 312 comprises a second radiating arm 3122 , Z shaped, extending along a direction reverse to the lengthwise radiating arm 3101 . The third radiating portion 314 connects the common radiating arm 3102 and the connecting portion 32 on a point P together. The radiating element 31 of the second antenna 3 is located on a plane same as the connecting portion 32 , and on the same side of the grounding element 6 as the radiating element 21 and the connecting portion 22 of the first antenna 2 .
In this embodiment of the present invention, the high-frequency radiating portion 210 of the first antenna 2 is used to receive and send the high frequency signal on 1800-1900 MHz, and the low-frequency radiating portion 212 is used to receive and send the low frequency signal on 900 MHz. The high-frequency radiating portion 310 of the second antenna 3 is used to receive and send the high frequency signal on 5 GHz, and the low-frequency radiating portion 312 is used to receive and send the low frequency signal on 2.4 GHz. The low-frequency radiating portion 212 of the first antenna 2 is adjacent to the low-frequency radiating portion 312 of the second antenna 3 . It's known that the radiating performance is greatly influenced by the impedance. In this embodiment, the first antenna 2 has small volume compared with conventional antenna while still has substantially same frequency and bandwidth because the aid of the insulative member 200 and the metal foil 300 . In addition, the existence of the reactance 400 regulates the impedance to increase the power of the low-frequency radiating portion 212 . FIG. 5 illustrates two gain curves of the first antenna 2 with the reactance 400 and without the reactance 400 . The gain increases 2 dBi when the reactance 400 is imported. Therefore, the antenna assembled reactance achieves good performance. Besides the excellent performance mentioned above, this method of assembling a reactance to the radiating element of the antenna of this embodiment has a simple manufacture process and low cost. In other embodiment, the reactance 400 can be assembled on different positions of different antennas in need.
While the foregoing description includes details which will enable those skilled in the art to practice the invention, it should be recognized that the description is illustrative in nature and that many modifications and variations thereof will be apparent to those skilled in the art having the benefit of these teachings. It is accordingly intended that the invention herein be defined solely by the claims appended hereto and that the claims be interpreted as broadly as permitted by the prior art. | A multi-band antenna includes a radiating element having at least two frequency bands and comprising a gap on one side edge thereof, a grounding element coupling and being perpendicular to said radiating element, and a reactance assembled to said radiating element and received in said gap. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods of producing fibre and has particular reference to methods of producing fibre having inherent flame retardancy properties.
2. Description of the Related Art
As used herein, the term "lyocell" is defined in accordance with the definition agreed by the Bureau International pour la Standardisation de la Rayonne et de Fibres Synthetique (BISFA) namely:
"A cellulose fibre obtained by an organic solvent spinning process; it being understood that:
(1) an "organic solvent" means essentially a mixture of organic chemicals and water; and
(2) "solvent spinning" means dissolving and spinning without the formation of a derivative".
As used herein, by a "flame retardancy chemical" is meant one which retards the burning of a product to which it is applied.
SUMMARY OF THE INVENTION
The present invention provides a method of producing a flame retardant lyocell fibre which comprises the steps of:
(i) forming a solution of cellulose in an organic solvent,
(ii) extruding the solution through a spinnerette downwardly into an air gap to form a plurality of strands,
(iii) passing the thusly formed strands downwardly through a water-containing spin bath,
(iv) leaching the solvent from the thusly formed strands to produce filaments of cellulose,
(v) incorporating into the filaments of cellulose, whilst still wet, a flame retardant chemical, and
(vi) fixing the chemical onto the cellulose to produce a cellulose filamentary material having inherent flame retardancy.
The present invention further provides a method of forming a flame retardant cellulose fibre comprising the steps of producing lyocell fibre and incorporating a flame retardant chemical into the fibre whilst the fibre is in the never-dried condition (i.e. prior to first drying).
The flame retardant chemical may be a phosphorous based chemical and may be a quaternary phosphonium compound. The flame retardant chemical may be tetrakis (hydroxymethyl) phosphonium salt.
The flame retardant chemical may be fixed by a curing process utilising the action of ammonia or heat. The flame retardant chemical is preferably applied to never-dried lyocell fibre in tow form. The tow may be cut into staple fibre prior to drying for the first time or after drying.
The tow having the flame retardant chemical or chemicals fixed thereon may be dried as tow, crimped and cut to form staple fibre. The tow may be provided with a finish, a chemical compound added to the tow to enhance or ease the processing of fibre during subsequent operations. The fixing of the flame retardant chemical to the cellulose may be carried out during the drying of the cellulose, or may be carried out as a separate step prior to the drying of the cellulose. Alternatively, the cellulose may be dried and then passed through a fixing process finally to fix the flame retardant chemical to the cellulose.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example the present invention will now be described with reference to the accompanying drawings.
FIG. 1 shows schematically an application route for the application of flame retardant (FR) PROBAN precondensate chemicals to fibre.
FIG. 2 shows schematically an application route for the application of FR PYROVATEX chemicals to fibre.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The production of lyocell fibre is described in U.S. Pat. No. 4,416,698, the contents of which are incorporated herein by way of reference. Lyocell fibre may be produced by any known manner. The invention is solely concerned with the production of a flame retardant lyocell fibre.
DESCRIPTION OF PREFERRED EMBODIMENTS
In a preferred process for the production of lyocell fibre, a solution of cellulose in an organic solvent, typically N-methyl morpholine N-oxide is formed by heating N-methyl morpholine N-oxide, water and cellulose to evaporate the water so as to form the solution. The solution may contain a suitable stabiliser. The solution is commonly referred to as a spinning dope. This dope is then forced through a spinnerette jet to pass in filamentary form as strands through an air gap into a spin bath. The spin bath contains water and leaches the solvent from the strands. During the leaching process the cellulose component of the solution re-forms to produce the cellulosic filamentary material. The filamentary material is in the form of a bundle of filaments, commonly referred to as a tow. The tow comprises essentially a plurality of parallel filaments, the number of filaments in the tow being equal to the number of strands produced by the spinnerette jet.
The tow of fibre having been produced by the leaching process is referred to as never-dried fibre, in the sense that the tow is still wet and has not been dried at that stage in its processing life. Never-dried fibre has slightly different physical characteristics to fibre which has been dried and is subsequently rewetted. Typically never-dried fibre contains a greater proportion of water than can be incorporated into dried fibre merely by wetting it.
One type of flame retardant treatment is the PROBAN precondensate treatment using tetrakis (hydroxymethyl) phosphonium (THP) available from Albright & Wilson Ltd., England.
The never-dried fibre is then treated to give it a PROBAN precondensate finish in accordance with the sequence illustrated in FIG. 1. The fibre is first passed through a bath containing PROBAN pre-condensate namely a mixture of tetrakis (hydroxymethyl) phosphonium and urea. The fibre emerging from the bath is then passed through the nip of a pair of rollers to remove excess pre-condensate. This is the process illustrated by block 1 in FIG. 1. The fibre is then passed through an ammonia solution or has ammonia sprayed onto it in box 2A. The thus treated fibre is then dried at 130° C. in a suitable drying equipment such as a drying tunnel or by being passed over heated drying rollers. The drying, at a temperature of 130° C. occurs in block 2B. In an alternative form of curing process, blocks 2A and 2B are replaced in their entirety by a heat cure step which occurs at 120°-170° C.
After the precondensate has been applied and cured onto the fibre it is oxidised as at block 3 using, for example, hydrogen peroxide solution.
The oxidised coating is then neutralised as at block 4 with, for example, a solution of sodium carbonate.
Subsequently the fibre is washed as at block 5 and is then passed through a soft finish roller as at block 6 prior to drying as at block 7.
The solutions of hydrogen peroxide, sodium carbonate or similar and soft finish can be applied either by dipping the fibre through the solution or by spraying a solution onto the fibre or by an other suitable means. Typically the fibre is washed by plating the fibre onto a porous support such as a steel mesh and then washing with demineralised water. The fibre is dried by suitable dryers such as drum dryers.
In an alternative process, PYROVATEX solution may be applied to the never-dried fibre. This process is illustrated in block form in FIG. 2. In this case the PYROVATEX solution is applied to the fibre at 8 by dipping the fibre in PYROVATEX solution, a fixing resin such as LYOFIX Resin and phosphoric acid. Subsequently the excess solution on the fibre is removed by passing the fibre through the nip of a pair of rolls. The fibre is then dried at 130° C. at 9 and cured in a separate curing oven at 160° C. for 5 minutes as shown at block 10. Subsequently the fibre is treated with sodium carbonate solution to neutralise the fibre as at block 11, washed as at block 12, has a soft finish applied to it as at block 13 and is then dried as at block 14. The solutions and drying processes described in connection with FIG. 2 would effectively be the same as those used in connection with the processed illustrated in connection with FIG. 1.
Once the never-dried fibre has been treated with THP or other treatment and cured it can then be dried in a conventional manner. The fibre is preferably washed prior to drying to remove excess THP from the fibre. The fibre can be dried either in tow form and utilised as tow, or it can be dried in tow form and subsequently cut to staple. Optionally the fibre may be crimped after drying by means of a mechanical crimping process, and then cut to form staple.
Alternatively, the fibre after curing may be cut to form staple, washed and dried as staple.
The flame retardant chemical may be applied to the fibre in staple form rather than in tow form. Thus after the leaching operation the fibre can be cut to form staple, washed, and the flame retardant chemical can then be applied to the staple. The staple can then be cured, washed and dried as staple. It is preferred, however, that the FR chemical be applied to the fibre in tow form because it is found that there is less entangling of the fibre and the tow treated fibre may be more readily carded to produce an open structure suitable for spinning. The treated fibre can then be processed in a conventional manner to produce fabric. In the case of filamentary material the filament would be wound up and converted by weaving or knitting or non-woven methods to produce a fabric. In the case of staple fibre, the fibre would be carded, spun and the yarn produced by spinning could be woven or knitted to produce a suitable fabric. The fabric may be dyed either after production or it may be dyed as yarn to produce a coloured yarn for the production of fabric.
Rather than using THP or other phosphorous-based compounds--typically quaternary phosphorous--based compounds, nitrogen-based compounds can be used or any other suitable flame retardant.
By incorporating the flame retardant chemical into the fibre in the never-dried state, it is possible to produce fibre which is inherently flame retardant when tested in accordance with British Standard 5867 and which produces fabrics having very good flame retardancy properties. The fibre can be treated on-line under controlled conditions and the customer need not carry out any subsequent flame retardancy treatment to have a flame retardant fabric. It is believed that never-dried fibre picks up about 75% by weight of the active phosphorous containing ingredient compared to a pick-up of about 30% by weight for dried fibre.
In a test, two samples of lyocell fibre were produced, one was dried and treated with 50% (by weight) PROBAN pre-condensate followed immediately by padding with a soft finish, CROSOFT XME finish at 20 g/l. The treated fibre was then dried at 70° C., cured in ammonia gas at ambient temperature, oxidised with hydrogen peroxide solution, neutralised with sodium carbonate, washed and dried. The other sample was given the same treatment, but the treatment was applied to lyocell fibre which had never been dried before the PROBAN precondensate and CROSOFT XME finish were applied.
The following results were obtained as set out in Table 1:
TABLE 1______________________________________ Never Dried Dried______________________________________1. Tensiles Tenacity (cN/tex) 34.05 30.64 Extension (%) 9.070 7.56 Dtex 2.129 2.202. Flame Retardancy % LOI 31 28 % Phosphorus (V) 4.15 2.46 % Phosphorus (III) 1.0 0.5 % Nitrogen 3.99 2.27 Formaldehyde (ppm) 170 1803. Additive Pick Up/Distribution Dry pick up (g/g) 0.45 0.28______________________________________
It can be seen, therefore, that the application of the PROBAN precondensate treatment to the never dried fibre not only significantly increases the LOI compared to the application to dried fibre, but that this is also accompanied by better tensile properties.
It can be seen that the phosphorus pick up in the never dried fibre is higher than in the dried fibre, and this is confirmed by elemental map micrographs. Comparing the elemental phosphorous maps across the individual fibres by means of line scans shows that there is a concentration of phosphorus in the skin of the dried fibre treated with Proban, whereas the fibre treated in the never dried condition shows a much more even distribution across the fibre. | A method of forming a flame retardant cellulose fiber is disclosed which comprises the steps of producing lyocell fiber and incorporating a flame retardant chemical into the fiber while the fiber is in the never-dried condition prior to first drying. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method of driving a plasma display panel, and more particularly to a method of driving an AC memory-operation type plasma display panel.
[0003] 2. Description of the Related Art
[0004] A plasma display panel is structurally grouped into a DC (direct current) type panel having electrodes exposed to discharge gas, and an AC (alternating current) type panel having electrodes covered with a dielectric layer to prevent from being directly exposed to discharge gas. An AC type plasma display panel is further structurally grouped into a memory-operation type panel which operates by virtue of a memory function caused by a function of a dielectric layer to store electric charges therein, and a refresh-operation type panel which operates not using a memory function.
[0005] Hereinbelow are explained a structure of an AC memory-operation type plasma display panel and a method of driving the same.
[0006] [0006]FIG. 1 is a perspective broken view of a conventional AC type plasma display panel suggested in Japanese Patent Application Publication No. 2001-272948.
[0007] As illustrated in FIG. 1, a plasma display panel 20 includes an electrically insulating front substrate 1 A and an electrically insulating rear substrate 1 B.
[0008] On the front substrate 1 A are arranged a scanning electrode 9 and a common electrode 10 spaced away from each other and in parallel with each other.
[0009] Each of the scanning electrode 9 and the common electrode 10 is comprised of a bus electrode 3 for presenting electrical conductivity, and a principal discharge electrode 2 formed on the bus electrode 3 for generating discharge therefrom. The principal discharge electrode 2 in the plasma display panel 20 is comprised of a transparent electrode composed of indium-tin oxide (ITO) or SnO 2 for preventing reduction in light transmissivity.
[0010] The scanning electrode 9 and the common electrode 10 are covered with a dielectric layer 4 a , which is covered with a protection film 5 composed of magnesium oxide to protect the dielectric layer 4 a from discharges.
[0011] On the rear substrate 1 B is arranged a plurality of data electrodes 6 extending in parallel with one another and perpendicularly to the scanning electrode 9 and the common electrode 10 .
[0012] The data electrodes 6 are covered with a dielectric layer 4 b . On the dielectric layer 4 b is formed a plurality of partition walls 7 extending in parallel with the data electrodes 6 for defining discharge areas and display cells.
[0013] A phosphor layer 8 is formed on an exposed surface of the dielectric layer 4 b and sidewalls of the partition walls 7 for converting ultra-violet rays generated by discharges, into visible light. By forming color phosphor layers in each of display cells, it would be possible to display colored images. For instance, color phosphor layers of three primary colors, that is, red (R), green (G) and blue (B) may be formed.
[0014] Discharge gas is introduced into a space sandwiched between the front and rear substrates 1 A and 1 B and partitioned by the partition walls 7 . For instance, discharge gas is comprised of helium (He), neon (Ne) and xenon (Xe) alone or in combination.
[0015] [0015]FIG. 2 is a plan view of the plasma display panel 20 as viewed from a viewer.
[0016] As illustrated in FIG. 2, the scanning electrode 9 and the common electrode 10 extend in a row direction in parallel with each other. A gap formed between the scanning electrode 9 and the common electrode 10 is called a discharge gap 12 , in which surface-discharge is generated between the scanning electrode 9 and the common electrode 10 .
[0017] Hereinbelow, a method of driving the plasma display panel 20 is explained with reference to FIG. 3.
[0018] [0018]FIG. 3 is a timing chart showing waveforms of pulse voltages applied to the scanning electrode 9 , the common electrode 10 and the data electrode 6 , and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge.
[0019] It is assumed in FIG. 3 that the previous sub-field is selected, but the illustrated sub-field is not selected.
[0020] Voltages are applied separately to each of the scanning and data electrodes 9 and 6 , and voltages having a common waveform are applied to all of the common electrodes 10 .
[0021] As illustrated in FIG. 3, a fundamental cycle for driving the plasma display panel 20 includes a reset period (A) in which display cells are reset for causing discharges to be readily generated in the subsequent period (B), a scanning period (B) in which it is selected which display cell or cells is(are) to be turned on or off, a sustaining period (C) in which discharges are generated in all of the selected display cells. Such a fundamental cycle is called a sub-field.
[0022] In the reset period, a sustaining-discharge eliminating pulse Pse is applied to all of the scanning electrodes 9 to generate charge-eliminating discharge to eliminate wall charges accumulated due to previous sustaining-discharge pulses.
[0023] Herein, the term “eliminate” should not be limited to elimination of all of wall charges, but should be interpreted as including reduction in wall charges for smoothly generating subsequent preliminary discharges, data-writing discharges and sustaining discharges.
[0024] The sustaining-discharge eliminating pulse Pse is a pulse voltage having an inclined waveform or a serrate waveform in which a voltage varies with the lapse of time.
[0025] Then, a positive priming pulse Pp+ is applied to all of the scanning electrodes 9 for causing compulsory discharges in all of the display cells. While the positive priming pulse Pp+ is being applied to the scanning electrode 9 , a negative priming pulse Pp− is applied to the common electrodes 10 .
[0026] Then, a priming-eliminating pulse Ppe is applied to all of the scanning electrodes 9 for causing charge-eliminating discharges to eliminate wall charges having been accumulated due to the positive priming pulse Pp+. The term “eliminate” should not be limited to elimination of all of wall charges, but should be interpreted as including reduction in wall charges for smoothly generating subsequent data-writing discharges and sustaining discharges.
[0027] Preliminary discharge caused by application of the positive priming pulse Pp+ and elimination of the preliminary discharge caused by application of the priming-eliminating pulse Ppe make subsequent data-writing discharge be readily generated.
[0028] Following the priming-eliminating pulse Ppe, a scanning base pulse Pbw is applied to the scanning electrode 9 .
[0029] The positive priming pulse Pp+ and the priming-eliminating pulse Ppe have an inclined waveform or a serrate waveform in which a voltage raises or lowers with the lapse of time. Discharge generated by application of a voltage having such an inclined waveform is just weak discharge which can extend only in the vicinity of the discharge gap 12 .
[0030] The above-mentioned preliminary discharge and charge-eliminating discharge are generated independently of images. Hence, light emission caused by those discharges is observed as background luminance. If the thus observed background luminance is at high level, contrast would be deteriorated, and hence, quality of images is degraded.
[0031] An operation of the plasma display panel 20 caused by the sustaining-discharge eliminating pulse Pse in a cross-section A 1 -A 2 (see FIG. 2) of the data electrode 6 in a display cell is explained hereinbelow with reference to FIG. 4 and FIGS. 5A to 5 E.
[0032] [0032]FIG. 4 illustrates the sustaining-discharge eliminating pulse Pse over a sustaining period to the next reset period, and FIGS. 5A to 5 E illustrate wall charges in a reset period in the case that weak discharges are stably generated.
[0033] In a conventional method of driving the plasma display panel 20 , a voltage Vs is applied to the scanning electrode 9 , and the common electrode 10 is grounded at a final sustaining discharge in a sustaining period.
[0034] Thus, as illustrated in FIG. 5A, negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 and positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 immediately before application of the sustaining-discharge eliminating pulse Pse and after sustaining discharge was generated. In contrast, positive electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 , as illustrated in FIG. 5A.
[0035] During the application of the sustaining-discharge eliminating pulse Pse to the scanning electrode 9 , the common electrode 10 is kept at the voltage Vs, and a voltage having an inclined or serrate waveform in which a voltage gradually varies to GND from the voltage Vs with the lapse of time is applied to the scanning electrode 9 (hereinbelow, such a voltage is referred to as “a serrate voltage”). After the application of the serrate voltage, when a sum of a voltage externally applied to the electrodes 9 and 10 and a voltage caused by wall charges exceeds a threshold voltage at which discharge starts, surface-discharge is generated between the scanning electrode 9 and the common electrode 10 .
[0036] The surface electrode starts at a time Tfsw (see FIG. 4). If the serrate voltage has an inclination of about 10V/microsecond or smaller, the surface-discharge is generated as weak discharge gradually expanding as the serrate voltage varies, as illustrated in FIG. 5B.
[0037] As illustrated in FIG. 5C, weak discharge is generated between the scanning electrode 9 and the common electrode 10 further at a time Tfss (see FIG. 4).
[0038] When a sum of a voltage externally applied to the electrodes 9 and 6 and a voltage caused by wall charges exceeds a threshold voltage at which discharge starts, cross-discharge is generated between the scanning electrode 9 and the data electrode 6 wherein the data electrode 6 is at a positive voltage and the scanning electrode 9 is at a negative voltage. The cross-discharge starts at a time Tfm (see FIG. 4).
[0039] As shown in FIG. 4, the time Tfsw is earlier than the time Tfm at which the cross-discharge is generated between the scanning electrode 9 and the data electrode 6 . That is, since the surface-discharge has been generated between the scanning electrode 9 and the common electrode 10 , ions and metastables already exist in a discharge space, namely, the discharge space is already activated. Accordingly, the cross-discharge is stably generated between the scanning electrode 9 and the data electrode 6 , as illustrated in FIG. 5D.
[0040] After the application of the sustaining-discharge eliminating pulse Pse to the scanning electrode 9 , electric charges are accumulated as illustrated in FIG. 5E.
[0041] An operation of the plasma display panel 20 caused by the priming-eliminating pulse Ppe is explained hereinbelow with reference to FIG. 6 and FIGS. 7A to 7 D.
[0042] [0042]FIG. 6 illustrates waveforms of the positive priming pulse Pp+ and the priming-eliminating pulse Ppe, and FIGS. 7A to 7 D illustrate wall charges in a reset period.
[0043] While the positive priming pulse Pp+ having an inclined waveform is applied to the scanning electrode 9 , the common electrode 10 is kept at GND.
[0044] When a sum of a voltage externally applied to the electrodes 9 and 10 and a voltage caused by wall charges exceeds a threshold voltage at which discharge starts, surface-discharge is generated between the scanning electrode 9 and the common electrode 10 . The surface-discharge is generated as weak discharge gradually expanding as the serrate voltage varies, similarly to discharge generated by the application of the sustaining-discharge eliminating pulse Pse to the scanning electrode 9 . The surface-discharge rearranges electric charges existing in the vicinity of the discharge gap 12 .
[0045] At the same time, cross-discharge is generated between the scanning electrode 9 and the data electrode 6 , resulting in that positive electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 .
[0046] After the application of the positive priming pulse Pp+ to the scanning electrode 9 has been terminated, as illustrated in FIG. 7A, negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , and positive electric charges are accumulated on the dielectric layer 4 b above the date electrode 6 .
[0047] While the priming-eliminating pulse Ppe having a negatively inclined waveform is applied to the scanning electrode 9 , the common electrode 10 is kept at the voltage Vs.
[0048] After the application of the priming-eliminating pulse Ppe to the scanning electrode 9 , when a sum of a voltage externally applied to the electrodes 9 and 10 and a voltage caused by wall charges exceeds a threshold voltage at which discharge starts, surface-discharge is generated between the scanning electrode 9 and the common electrode 10 . The surface-discharge starts at a time Tfsw (see FIG. 4). The surface-discharge is generated as weak discharge gradually expanding as the serrate voltage varies, as illustrated in FIG. 7B.
[0049] When a sum of a voltage externally applied to the electrodes 9 and 6 and a voltage caused by wall charges exceeds a threshold voltage at which discharge starts, cross-discharge is generated between the scanning electrode 9 and the data electrode 6 . The cross-discharge starts at a time Tfm (see FIG. 4).
[0050] Weak discharge is generated between the scanning electrode 9 and the common electrode 10 also at a time Tfss (see FIG. 6)
[0051] The time Tfsw at which the surface-discharge is generated between the scanning electrode 9 and the common electrode 10 is earlier than the time Tfm at which the cross-discharge is generated between the scanning electrode 9 and the data electrode 6 . That is, when the cross-discharge is generated between the scanning electrode 9 and the data electrode 6 , the surface-discharge has been already generated between the scanning electrode 9 and the common electrode 10 , as illustrated in FIGS. 7B and 7C.
[0052] After the application of the priming-eliminating pulse Ppe to the scanning electrode 9 has been terminated, electric charges are arranged such that operation in the subsequent scanning period can be smoothly carried out, as illustrated in FIG. 7D. That is, negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , and positive electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 .
[0053] When not selected in the subsequent scanning period, that is, when data-writing discharge is not generated, wall charges are reduced to such a degree that discharge is not generated in a sustaining period.
[0054] In a scanning period in which discharge is generated to select a display cell in which a light is to be emitted, a scanning pulse Pw is applied to the scanning electrodes 9 one by one at different timings from one another, and a data pulse Pd having a voltage Vd is applied to the data electrode 6 in accordance with images to be displayed and in synchronization with a timing at which the scanning pulse was applied. The voltage Vd is equal to about 70V, for instance. In a display cell in which while the scanning pulse Pw is applied to scanning electrode 9 , the data pulse Pd is applied to the data electrode 6 , cross-discharge is generated between the scanning electrode 9 and the data electrode 6 , and the cross-discharge induces surface-discharge to be generated between the scanning electrode 9 and the common electrode 10 . A series of these actions is called data-writing discharge.
[0055] As a result of the generation of the data-writing discharge, positive electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , negative electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , and negative electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 .
[0056] As a result of first sustaining-discharge, negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , and positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 .
[0057] In a second sustaining-pulse, a voltage has a polarity opposite to a polarity of a voltage to be applied to the scanning electrode 9 and the common electrode 10 in accordance with a first sustaining-pulse. Hence, a voltage caused by electric charges accumulated on the dielectric layer 4 a is added to a voltage in the second sustaining-pulse, and accordingly, there is generated second sustaining-discharge.
[0058] Hereinafter, sustaining-discharges are generated in the same way. If surface-discharge is not generated by virtue of the first sustaining-pulse, discharge will not be generated due to subsequent sustaining-pulses.
[0059] A combination of the above-mentioned reset period, scanning period and sustaining period is called a sub-field.
[0060] In order to accomplish displaying images at gray scales, one field which is a period for displaying one scene is divided into a plurality of sub-fields, and the different number of sustaining-pulses is assigned to each of sub-fields. If one field is divided into N sub-fields, and a luminance ratio among the sub-fields is defined equal to 2 (N−1) , it would be possible to display images at 2 N gray scales by selecting sub-fields to be displayed in a field and combining them with one another.
[0061] For instance, it is assumed that one field is divided into eight (8) sub-fields. Since the eighth power of two is equal to 256 (2 8 =256), it is possible to display images at 256 gray scales by controlling on/off of each of the eight sub-fields.
[0062] The above-mentioned conventional method of driving the plasma display panel 20 is accompanied with problems that weak discharge is not generated, but intensive discharge is generated at a voltage beyond a voltage at which weak discharge is to be generated, in a pulse having an inclined waveform in which a voltage gradually varies with the lapse of time, and that there is generated a difference in a panel in intensity of weak discharges, and resultingly, wall charges are not arranged uniformly in the panel.
[0063] [0063]FIG. 8 illustrates electric lines of force in an electric field generated between the scanning electrode 9 and the common electrode 10 . The reason for the above-mentioned problems is explained hereinbelow with reference to FIG. 8.
[0064] As shown with electric lines of force in FIG. 8, an electric field generated between the scanning electrode 9 and the common electrode 10 is curved about the discharge gap 12 as a center. Hence, the electric filed has a relatively small density in an area remote from the discharge gap 12 , whereas the electric field has a relatively high density in an area close to the discharge gap 12 . Accordingly, a remarkably intensive electric field is generated at the discharge gap 12 .
[0065] [0065]FIGS. 9A to 9 E illustrate arrangement of wall charges in a reset period in the case that there is generated intensive discharge.
[0066] In the conventional method of driving the plasma display panel 20 , the voltage Vs is applied to the scanning electrode 9 , and the common electrode 10 is kept at GND when final sustaining-discharge is generated in a sustaining period.
[0067] Accordingly, after the generation of the sustaining-discharge has been terminated and immediately before the sustaining-discharge eliminating pulse Pse is applied to the scanning electrode 9 , negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , and positive electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 , as illustrated in FIG. 9A.
[0068] If an efficiency at which discharge is generated is lowered at the application of the sustaining-discharge eliminating pulse Pse, surface-discharge is not accidentally generated at the time Tfsw (see FIG. 9B), but is sometimes generated at a time later than the time Tfsw.
[0069] If surface-discharge is generated between the scanning electrode 9 and the common electrode 10 at a time later than the time Tfsw, a voltage difference higher than a voltage difference found at a time at which discharge should start is applied across the scanning electrode 9 and the common electrode 10 , because a voltage in a pulse having an inclined waveform is lowered during the time Tfsw to the time at which surface-discharge is actually generated. As a result, the resultant surface-discharge expands to a higher degree than weak discharge, that is, there is generated discharge slightly more intensive than expected.
[0070] As mentioned above, a remarkably intensive electric field is generated at the discharge gap 12 formed between the scanning electrode 9 and the common electrode 10 . Hence, if there is generated discharge slightly more intensive than expected, the discharge swiftly grows into intensive discharge which expands all over a display cell, as illustrated in FIG. 9C.
[0071] The time Tfss shown in FIG. 4 is an earliest time at which such intensive discharge may be generated.
[0072] If intensive discharge is generated, positive electric charges are accumulated entirely on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges are accumulated entirely on the dielectric layer 4 a above the common electrode 10 , as illustrated in FIG. 9D.
[0073] Hereinafter, since discharge is never generated during application of a pulse voltage having an inclined waveform, to the scanning electrode 9 , wall charges are arranged as illustrated in FIG. 9E after the application of the sustaining-discharge eliminating pulse Pse. That is, positive electric charges are accumulated on the dielectric layer 4 b above the data electrode 6 , but positive electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , contrary to the arrangement of wall charges illustrated in FIG. 5E.
[0074] After the application of the sustaining-discharge eliminating pulse Pse to the scanning electrode 9 , wall charges are re-arranged by the positive priming pulse Pp+ and the priming-eliminating pulse Ppe. Arrangement of wall charges by the pulses Pp+ and Ppe is accomplished by generating weak discharge, similarly to the sustaining-discharge eliminating pulse Pse. Hence, influence caused by intensive discharge generated when the sustaining-discharge eliminating pulse Pse is applied to the scanning electrode 9 can be eliminated in the vicinity of the discharge gap 12 . However, it will be impossible to eliminate such influence all over a display cell. In particular, in an area remote from the discharge gap 12 , positive electric charges remain accumulated on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges remain accumulated on the dielectric layer 4 a above the common electrode 10 .
[0075] In a subsequent scanning period, voltages applied to the electrodes 9 and 10 are determined such that the plasma display panel can stably operate when negative electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , and positive electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 (see FIG. 5E). Accordingly, if positive electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , the plasma display panel operates unstably.
[0076] In order to reduce a background luminance, the positive priming pulse Pp+ and the priming-eliminating pulse Ppe are not sometimes applied to the scanning electrode 9 in a certain sub-field. This is because it is possible to arrange wall charges similarly to the arrangement of wall charges found after the application of the priming-eliminating pulse Ppe, even after wall charges have been arranged by the sustaining-discharge eliminating pulse Pse. Hence, the plasma display panel can operate stably in a subsequent scanning period in the same way as a case in which the positive priming pulse Pp+ and the priming-eliminating pulse Ppe are applied to the scanning electrode 9 .
[0077] However, if there is generated intensive discharge in the sustaining-discharge eliminating pulse Pse, positive electric charges are accumulated on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges are accumulated on the dielectric layer 4 a above the common electrode 10 , as illustrated in FIG. 9E. Since a subsequent scanning period starts in such a condition, there is caused erroneous light-emission, that is, light is emitted even in a non-selected display cell.
[0078] In addition, if positive electric charges accumulated on the dielectric layer 4 a above the scanning electrode 9 and negative electric charges accumulated on the dielectric layer 4 a above the common electrode 10 are not sufficiently eliminated, there is generated intensive discharge 30 B (see FIG. 3) as erroneous discharge in a sustaining period, or the priming-eliminating pulse Ppe causes intensive discharge, and accordingly, there is generated intensive discharge 30 B (see FIG. 3) as erroneous discharge in a sustaining period.
[0079] In order to prevent such erroneous light-emission, it is necessary to prevent generation of intensive discharge in the sustaining-discharge eliminating pulse Pse. If it is not possible to prevent generation of such intensive discharge, it would be necessary to prepare a countermeasure to such intensive discharge.
[0080] If an efficiency at which discharges are generated in the priming-eliminating pulse Ppe, similarly to the sustaining-discharge eliminating pulse Pse, weak discharge may not be generated between the scanning electrode 9 and the common electrode 10 .
[0081] If discharge is generated later, the resultant discharge would be more intensive than weak discharge because of a higher voltage difference than a voltage difference found at a time at which discharge should start is applied across the scanning electrode 9 and the common electrode 10 . Since a remarkably intensive electric field is generated at the discharge gap 12 formed between the scanning electrode 9 and the common electrode 10 , the discharge swiftly grows into intensive discharge 30 A (see FIG. 3) which expands all over a display cell. The time Tfss shown in FIG. 6 is an earliest time at which such intensive discharge 30 A is generated.
[0082] The generation of intensive discharge results in that positive electric charges are accumulated entirely on the dielectric layer 4 a above the scanning electrode 9 , and negative electric charges are accumulated entirely on the dielectric layer 4 a above the common electrode 10 . This is the same arrangement of wall charges as the arrangement found after data-writing discharge has been generated in a selected display cell in a scanning period.
[0083] Accordingly, even if not selected in a subsequent scanning period, if intensive discharge 30 A is generated in the priming-eliminating pulse Ppe, there would be generated discharge because of addition of wall charges to an externally applied voltage when a first sustaining-pulse Ps is applied to the electrodes. Discharges are continuously generated even in second and later sustaining pulses Pse.
[0084] As a result, there is caused erroneous light-emission, that is, light is emitted even in a non-selected display cell. In order to prevent such erroneous light-emission, it would be necessary to prevent generation of the intensive discharge 30 A in the priming-eliminating pulse Ppe, or to eliminate influence exerted by the intensive discharge 30 A, even if the intensive discharge 30 A was generated.
[0085] As explained above, the conventional method of driving the plasma display panel 20 is accompanied with a problem that images are deteriorated as a result that light is emitted in a non-selected display cell, namely, there occurs erroneous light-emission.
[0086] For instance, Japanese Patent Application Publication 2000-122602 has suggested a method of driving a plasma display panel which method is capable of solving a problem of erroneous light-emission.
[0087] Specifically, in the suggested method, surface-discharge and cross-discharge in charge-eliminating discharge are generated temporally separately from each other.
[0088] However, the suggested method is accompanied with a problem that if the discharges are concurrently generated, it would be quite difficult to control electric charges accumulated above a data electrode with the result of erroneous operation in a scanning period.
[0089] Specifically, if a ratio at which discharges are generated is quite low, priming particles are soon reduced when a certain period of time passes after generation of discharge. Accordingly, if surface-discharge and cross-discharge are generated temporally separately from each other as in the above-mentioned method, even if cross-discharge is first generated as weak discharge, subsequent surface-discharge will be generated as intensive discharge.
[0090] Thus, even in the above-mentioned method, the problem that light is emitted in a non-selected cell due to intensive discharge is not always solved.
SUMMARY OF THE INVENTION
[0091] In view of the above-mentioned problem in the conventional method, it is an object of the present invention to provide a method of driving a plasma display panel which method is capable of, even if intensive discharge is accidentally generated, preventing erroneous light-emission due to the accidentally generated intensive discharge, and further preventing occurrence of phenomenon that an area which should be displayed dark is displayed bright due to erroneous light-emission.
[0092] In one aspect of the present invention, there is provided a method of driving a plasma display panel comprised of (A) a first substrate including at least one first electrode, and at least one second electrode extending in parallel with the first electrode and defining a display area with the first electrode therebetween, and (B) a second substrate including at least one third electrode facing the first and second electrodes and extending perpendicularly to the first and second electrodes, wherein a display cell is arranged at each of intersections of the first and second electrodes with the third electrode, the method including (a) applying a serrate voltage having an inclined waveform in which a voltage varies with the lapse of time, to at least one of the first and second electrodes, and (b) applying a preliminary charge-eliminating pulse voltage to at least one of the first and second electrodes after the a charge-eliminating discharge has been generated due to the serrate voltage, wherein the preliminary charge-eliminating pulse voltage eliminates electric charges only when electric charges have not been sufficiently eliminated.
[0093] It is preferable that the preliminary charge-eliminating pulse voltage carries out narrow-width charge-elimination.
[0094] It is preferable that the preliminary charge-eliminating pulse voltage has a pulse width in the range of 0.5 to 2 microseconds both inclusive.
[0095] It is preferable that a negative preliminary charge-eliminating pulse voltage is applied to the second electrode.
[0096] It is preferable that a positive preliminary charge-eliminating pulse voltage is applied to the first electrode.
[0097] It is preferable that negative and positive preliminary charge-eliminating pulse voltages are concurrently applied to the second and first electrodes, respectively.
[0098] The method may further include (c) applying a preliminary pre-eliminating adjusting pulse voltage to at least one of the first and second electrodes to cause generate discharge in a display cell in which electric charges have not been sufficiently eliminated, the step (c) being carried out between the steps (a) and (b).
[0099] It is preferable that the preliminary pre-eliminating adjusting pulse voltage is applied to an electrode other than an electrode to which the preliminary charge-eliminating pulse voltage is applied.
[0100] It is preferable that the preliminary pre-eliminating adjusting pulse voltage has a pulse width greater than a pulse width of the preliminary charge-eliminating pulse voltage.
[0101] It is preferable that the preliminary pre-eliminating adjusting pulse voltage is applied a plurality of times to at least one of the first and second electrodes in the step (c).
[0102] It is preferable that the preliminary pre-eliminating adjusting pulse voltage has a pulse width in the range of 2 to 10 microseconds both inclusive.
[0103] It is preferable that the preliminary pre-eliminating adjusting pulse voltage is applied to at least one of the first and second electrodes immediately before application of the preliminary charge-eliminating pulse voltage.
[0104] It is preferable that the preliminary pre-eliminating adjusting pulse voltage has the same polarity as that of the preliminary charge-eliminating pulse voltage.
[0105] It is preferable that the preliminary charge-eliminating pulse voltage carries out thick-width charge-elimination.
[0106] It is preferable that the preliminary charge-eliminating pulse voltage has a pulse width in the range of 2 to 50 microseconds both inclusive.
[0107] It is preferable that the preliminary charge-eliminating pulse voltage is comprised of a self-eliminating pulse voltage.
[0108] It is preferable that a preliminary pre-eliminating adjusting pulse voltage is applied to an electrode other than an electrode to which the self-eliminating pulse voltage is applied such that the preliminary pre-eliminating adjusting pulse voltage temporally overlaps the self-eliminating pulse voltage, to generate discharge in a display cell in which electric charges have not been sufficiently eliminated.
[0109] For instance, the self-eliminating pulse voltage has a pulse width in the range of 2 to 50 microseconds both inclusive.
[0110] It is preferable that the preliminary charge-eliminating pulse voltage is applied to at least one of the first and second electrodes as a part of a pulse voltage applied in a scanning period.
[0111] It is preferable that the preliminary pre-eliminating adjusting pulse voltage generates an electric field having a polarity opposite to a polarity of an electric field generated by the preliminary charge-eliminating pulse voltage.
[0112] It is preferable that a time at which cross-discharge is generated between the third electrode and one of the first and second electrodes is set earlier than a time at which surface-discharge is generated between the first and second electrodes.
[0113] It is preferable that a preliminary pulse voltage is applied to the third electrode in synchronization with a timing at which application of the preliminary charge-eliminating pulse voltage starts, the preliminary pulse voltage having a polarity opposite to a polarity of the preliminary charge-eliminating pulse voltage.
[0114] It is preferable that a preliminary pulse voltage is applied to the third electrode in synchronization with a timing at which application of the preliminary pre-eliminating adjusting pulse voltage starts, the preliminary pulse voltage having a polarity opposite to a polarity of the preliminary pre-eliminating adjusting pulse voltage.
[0115] It is preferable that the preliminary pulse voltage is equal to a data pulse voltage.
[0116] For instance, the preliminary pulse voltage has a pulse width in the range of 0.1 to 2 microseconds both inclusive.
[0117] It is preferable that n the preliminary pulse voltage has a pulse width equal to or smaller than a pulse width of the preliminary charge-eliminating pulse voltage.
[0118] The advantages obtained by the aforementioned present invention will be described hereinbelow.
[0119] In accordance with the above-mentioned present invention, a serrate voltage having an inclined waveform in which a voltage varies with the lapse of time is applied to the first and/or second electrodes to generate weak discharge. Hence, it is possible to prevent generation of intensive discharge. Even if it is impossible to prevent generation of intensive discharge by application of the serrate voltage, it would be possible to prevent erroneous light-emission caused by intensive discharge, and further prevent occurrence of phenomenon that an area which should be displayed dark is displayed bright due to erroneous light-emission, by applying the preliminary charge-eliminating pulse voltage to the first and/or second electrodes.
[0120] The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0121] [0121]FIG. 1 is a perspective broken view of a conventional plasma display panel.
[0122] [0122]FIG. 2 is a plan view of the plasma display panel illustrated in FIG. 1, as viewed from a viewer.
[0123] [0123]FIG. 3 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge.
[0124] [0124]FIG. 4 is a partially enlarged view of FIG. 3.
[0125] [0125]FIGS. 5A to 5 E illustrate wall charges in a reset period in the case that weak discharges are stably generated, in the conventional plasma display panel.
[0126] [0126]FIG. 6 is a partially enlarged view of FIG. 3.
[0127] [0127]FIGS. 7A to 7 D illustrate wall charges in a reset period in the conventional plasma display panel.
[0128] [0128]FIG. 8 illustrates electric lines of force in an electric field generated between a scanning electrode and a common electrode in the conventional plasma display panel.
[0129] [0129]FIGS. 9A to 9 E illustrate arrangement of wall charges in a reset period in the case that there is generated intensive discharge, in the conventional plasma display panel.
[0130] [0130]FIG. 10 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with the first embodiment of the present invention.
[0131] [0131]FIG. 11 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with the second embodiment of the present invention.
[0132] [0132]FIG. 12 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with the third embodiment of the present invention.
[0133] [0133]FIG. 13 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with the fourth embodiment of the present invention.
[0134] [0134]FIG. 14 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with a first example of the fifth embodiment of the present invention.
[0135] [0135]FIG. 15 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with a second example of the fifth embodiment of the present invention.
[0136] [0136]FIG. 16 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with a third example of the fifth embodiment of the present invention.
[0137] [0137]FIG. 17 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in a method of driving a plasma display panel, in accordance with a fourth example of the fifth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0138] Preferred embodiments in accordance with the present invention will be explained hereinbelow with reference to drawings.
[0139] [First Embodiment]
[0140] Hereinbelow is explained a method of driving a plasma display panel, in accordance with the first embodiment with reference to FIG. 10.
[0141] A plasma display panel to which the method in accordance with the first embodiment is carried out has the same structure as that of the conventional plasma display panel illustrated in FIG. 1.
[0142] [0142]FIG. 10 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in the method in accordance with the first embodiment.
[0143] [0143]FIG. 10 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected.
[0144] In the first embodiment, a preliminary charge-eliminating pulse Phe is applied to the common electrode 10 immediately after a priming-eliminating pulse Ppe has been applied to the scanning electrode 9 . In the first embodiment, a preliminary charge-elimination period is arranged between a reset period and a scanning period. The preliminary charge-eliminating pulse Phe is applied to the common electrode 10 in the preliminary charge-elimination period.
[0145] The preliminary charge-eliminating pulse Phe causes discharge only in a display cell in which charges are not sufficiently eliminated, namely, intensive discharge 30 A is generated, even though the preliminary charge-eliminating pulse Phe has been applied to the scanning electrode 9 .
[0146] By applying the preliminary charge-eliminating pulse Phe to the common electrode 10 , a voltage across the scanning electrode 9 and the common electrode 10 is lowered immediately after generation of the intensive discharge 30 A, and hence, electric charges are not attracted to the scanning and common electrodes 9 and 10 . As a result, it is possible to prevent generation of wall charges. Accordingly, it is possible to suppress generation of erroneous discharge (namely, the intensive discharge 30 B) in scanning and sustaining periods following a reset period, and further prevent erroneous light-emission caused by the erroneous discharge, ensuring qualified images without occurrence of phenomenon that an area which should be displayed dark is displayed bright.
[0147] The preliminary charge-eliminating pulse Phe in the first embodiment carries out so-called narrow-width charge-elimination, and is designed to have a pulse width in the range of 0.5 to 2.0 microseconds. If intensive discharge is not generated in a reset period, the preliminary charge-eliminating pulse Phe is designed to have such a voltage that discharge is not generated.
[0148] The preliminary charge-eliminating pulse Phe has a voltage in the range of about −150 to −200V relative to a voltage of the scanning electrode 9 . In the first embodiment, the preliminary charge-eliminating pulse Phe is designed to have a voltage of about −170V relative to a voltage of the scanning electrode 9 .
[0149] In place of applying the negative preliminary charge-eliminating pulse Phe to the common electrode 10 , a positive preliminary charge-eliminating pulse may be applied to the scanning electrode 9 . As an alternative, a negative preliminary charge-eliminating pulse Phe and a positive preliminary charge-eliminating pulse may be concurrently applied to the common and scanning electrodes 10 and 9 , respectively. In both cases, even when electric charges are not sufficiently eliminated because of generation of intensive discharge in a reset period or for any reasons, narrow-width charge-elimination can be carried out by setting a voltage difference between the scanning and common electrodes 9 and 10 at the application of the preliminary charge-eliminating pulse Phe, equal to or greater than a voltage at which discharge starts.
[0150] [0150]FIG. 10 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected. However, it should be noted that waveforms of light-emission remain unchanged regardless of whether the previous and present sub-fields are selected or not.
[0151] [Second Embodiment]
[0152] Hereinbelow is explained a method of driving a plasma display panel, in accordance with the second embodiment with reference to FIG. 11.
[0153] A plasma display panel to which the method in accordance with the second embodiment is carried out has the same structure as that of the conventional plasma display panel illustrated in FIG. 1.
[0154] [0154]FIG. 11 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in the method in accordance with the second embodiment.
[0155] [0155]FIG. 11 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected.
[0156] In the second embodiment, a preliminary charge-elimination period is arranged between a reset period and a scanning period. In the preliminary charge-elimination period, the above-mentioned preliminary charge-eliminating pulse Phe is applied to the scanning electrode 9 , and further, a preliminary pre-eliminating adjusting pulse Pph is applied to the common electrode 10 immediately before the application of the preliminary charge-eliminating pulse Phe to the scanning electrode 9 .
[0157] When the intensive discharge 30 A is generated because of the application of the priming-eliminating pulse Ppe to the scanning electrode 9 , wall charges are arranged in dependence on a timing at which the intensive discharge 30 A is generated, namely, a voltage applied when the intensive discharge 30 A is generated. As a result, there is caused a difference in discharges caused by the preliminary charge-eliminating pulse Phe in display cells in which charges are not sufficiently eliminated, and hence, there is caused non-uniformity in charge-elimination among display cells.
[0158] Even when charges are not sufficiently eliminated because of generation of intensive discharge in a reset period or for any reasons, it would be possible to optimize arrangement of wall charges and allow charge-eliminating discharge caused by the preliminary charge-eliminating pulse Phe to be stably generated, by applying the preliminary pre-eliminating adjusting pulse Pph immediately before the application of the preliminary charge-eliminating pulse Phe to thereby generate discharge. As a result, it is possible to suppress generation of erroneous discharge (namely, the intensive discharge 30 B) in scanning and sustaining periods following a reset period, and further prevent erroneous light-emission caused by the erroneous discharge, ensuring qualified images without occurrence of phenomenon that an area which should be displayed dark is displayed bright.
[0159] The preliminary pre-eliminating adjusting pulse Pph is designed to have a pulse width greater than the same of the preliminary charge-eliminating pulse Phe. Specifically, the preliminary pre-eliminating adjusting pulse Pph is designed to have a pulse width in the range of 2 to 10 microseconds.
[0160] The preliminary pre-eliminating adjusting pulse Pph has a voltage in the range of about −150 to −200V relative to a voltage of the scanning electrode 9 . In the second embodiment, the preliminary pre-eliminating adjusting pulse Pph is designed to have a voltage of about −170V relative to a voltage of the scanning electrode 9 .
[0161] The negative preliminary charge-eliminating pulse Phe is applied to the scanning electrode 9 , and the negative preliminary pre-eliminating adjusting pulse Pph is applied to the common electrode 10 in the second embodiment. To the contrary, a positive preliminary charge-eliminating pulse Phe may be applied to the common electrode 10 , and a positive preliminary pre-eliminating adjusting pulse Pph may be applied to the scanning electrode 9 .
[0162] The negative preliminary pre-eliminating adjusting pulse Pph is applied only once to the common electrode 10 in the second embodiment. As an alternative, for instance, after the negative preliminary pre-eliminating adjusting pulse Pph has been applied to the common electrode 10 , the positive preliminary pre-eliminating adjusting pulse Pph and the negative preliminary charge-eliminating pulse Phe may be applied to the scanning and common electrodes 9 and 10 , respectively. That is, the preliminary pre-eliminating adjusting pulse Pph may be applied twice or greater, if necessary.
[0163] [0163]FIG. 11 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected. However, it should be noted that waveforms of light-emission remain unchanged regardless of whether the previous and present sub-fields are selected or not.
[0164] [Third Embodiment]
[0165] Hereinbelow is explained a method of driving a plasma display panel, in accordance with the third embodiment with reference to FIG. 12.
[0166] A plasma display panel to which the method in accordance with the third embodiment is carried out has the same structure as that of the conventional plasma display panel illustrated in FIG. 1.
[0167] [0167]FIG. 12 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in the method in accordance with the third embodiment.
[0168] [0168]FIG. 12 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected.
[0169] In the third embodiment, a preliminary charge-eliminating pulse Phe is applied to the common electrode 10 immediately after the application of the priming-eliminating pulse Ppe to the scanning electrode 9 , similarly to the first embodiment. In the third embodiment, a preliminary charge-elimination period is arranged between a reset period and a scanning period, similarly to the first and second embodiments. The preliminary charge-eliminating pulse Phe is applied to the common electrode 10 in the preliminary charge-elimination period.
[0170] The third embodiment makes it possible to suppress generation of erroneous discharge (namely, the intensive discharge 30 B) in scanning and sustaining periods following a reset period, and further prevent erroneous light-emission caused by the erroneous discharge, ensuring qualified images without occurrence of phenomenon that an area which should be displayed dark is displayed bright.
[0171] The preliminary charge-eliminating pulse Phe causes discharge only in a display cell in which charges have not been sufficiently eliminated, that is, there has been generated intensive discharge 30 A, even though the priming-eliminating pulse Ppe was applied to the scanning electrode 9 .
[0172] Whereas the preliminary charge-eliminating pulse Phe in the first embodiment carries out narrow-width charge-elimination, the preliminary charge-eliminating pulse Phe in the third embodiment carries out thick-width charge-elimination. Herein, thick-width charge-elimination means elimination of charges by applying a pulse having such a low voltage that there is not generated intensive discharge, to an electrode to thereby generate weak discharge. Since weak discharge is generated in thick-width charge-elimination, wall charges are generated in a small amount, which means that charges are eliminated to some degree.
[0173] Since a pulse for carrying out narrow-width charge-elimination has a narrow width like the preliminary charge-eliminating pulse Phe in the first embodiment, discharge for eliminating charges may not be generated while the preliminary charge-eliminating pulse Phe for carrying out narrow-width charge-elimination is being applied to the electrode. In contrast, the third embodiment makes it possible to generate charge-eliminating discharge more surely than the narrow-width charge-elimination by designing the preliminary charge-eliminating pulse Phe to have a sufficient pulse width to ensure generation of charge-eliminating discharge.
[0174] The preliminary charge-eliminating pulse Phe in the third embodiment is designed to have a lower voltage than a voltage of the preliminary charge-eliminating pulse Phe in the first embodiment. Whereas the preliminary charge-eliminating pulse Phe in the first embodiment has a voltage in the range of about −150V to −200V relative to a voltage of the scanning electrode 9 , the preliminary charge-eliminating pulse Phe in the third embodiment is designed to have a voltage in the range of about −100V to −150V relative to a voltage of the scanning electrode 9 . In the third embodiment, the preliminary charge-eliminating pulse Phe has a voltage of about −150V relative to a voltage of the scanning electrode 9 .
[0175] Since the preliminary charge-eliminating pulse Phe in the third embodiment has a lower voltage than a voltage of the preliminary charge-eliminating pulse Phe in the first embodiment, as mentioned above, the preliminary charge-eliminating pulse Phe in the third embodiment is designed to have a longer pulse width than a pulse width of the preliminary charge-eliminating pulse Phe in the first embodiment in order to ensure generation of discharge when charges are not sufficiently eliminated because of generation of intensive discharge in a reset period or for any reasons. Specifically, whereas the preliminary charge-eliminating pulse Phe in the first embodiment is designed to have a pulse width in the range of 0.5 to 2.0 microseconds both inclusive, the preliminary charge-eliminating pulse Phe in the third embodiment is designed to have a pulse width in the range of 2 to 50 microseconds both inclusive.
[0176] [0176]FIG. 12 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected. However, it should be noted that waveforms of light-emission remain unchanged regardless of whether the previous and present sub-fields are selected or not.
[0177] [Fourth Embodiment]
[0178] Hereinbelow is explained a method of driving a plasma display panel, in accordance with the fourth embodiment with reference to FIG. 13.
[0179] A plasma display panel to which the method in accordance with the fourth embodiment is carried out has the same structure as that of the conventional plasma display panel illustrated in FIG. 1.
[0180] [0180]FIG. 13 is a timing chart showing waveforms of pulse voltages applied to electrodes, and further showing waveforms of a light emitted in normal operation and at generation of intensive discharge, in the method in accordance with the fourth embodiment.
[0181] [0181]FIG. 13 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected.
[0182] In the third embodiment, the above-mentioned preliminary pre-eliminating adjusting pulse Pph is applied to the common electrode 10 , and further, the above-mentioned preliminary charge-eliminating pulse Phe is applied to the scanning electrode 9 , similarly to the second embodiment. In the third embodiment, a preliminary charge-elimination period is arranged between a reset period and a scanning period. In the preliminary charge-elimination period, the preliminary pre-eliminating adjusting pulse Pph and the preliminary charge-eliminating pulse Phe are applied to the common electrode 10 and the scanning electrode 9 , respectively.
[0183] Whereas the preliminary charge-eliminating pulse Phe was applied to the scanning electrode 9 as a single pulse independently of other pulses, the preliminary charge-eliminating pulse Phe in the third embodiment is applied to scanning electrode 9 as a part of a scanning base pulse Pbw and further as a self-eliminating pulse.
[0184] Herein, the term “self-eliminating” indicates generation of discharge caused by wall charges when a difference among voltages applied to electrodes is set equal to zero or set low. A self-eliminating pulse has a function of eliminating wall charges.
[0185] By applying the preliminary charge-eliminating pulse Phe to the scanning electrode 9 as a self-eliminating pulse, it would be possible to suppress generation of erroneous discharge (namely, the intensive discharge 30 B) in scanning and sustaining periods following a reset period, and further prevent erroneous light-emission caused by the erroneous discharge, ensuring qualified images without occurrence of phenomenon that an area which should be displayed dark is displayed bright.
[0186] In addition, the preliminary charge-eliminating pulse Phe can be designed to have a pulse width shorter than a pulse width in a pulse for carrying out thick-width charge-elimination.
[0187] The preliminary charge-eliminating pulse Phe in the third embodiment has a pulse width in the range of 2 to 50 microseconds both inclusive.
[0188] The preliminary charge-eliminating pulse Phe in the fourth embodiment has a voltage in the range of about −150V to −200V relative to a voltage of the common electrode 10 generating charge-eliminating discharge. In the fourth embodiment, the preliminary charge-eliminating pulse Phe has a voltage of about −170V relative to a voltage of the common electrode 10 generating charge-eliminating discharge.
[0189] The preliminary pre-eliminating adjusting pulse Pph in the fourth embodiment has a voltage in the range of about −150V to −200V relative to a voltage of the common electrode 10 generating charge-eliminating discharge. In the fourth embodiment, the preliminary pre-eliminating adjusting pulse Pph has a voltage of about −170V relative to a voltage of the common electrode 10 generating charge-eliminating discharge.
[0190] The preliminary charge-eliminating pulse Phe was applied to the scanning electrode 9 immediately after the application of the preliminary pre-eliminating adjusting pulse Pph to the common electrode 10 in the second embodiment. That is, the preliminary charge-eliminating pulse Phe is applied to the scanning electrode 9 temporally separately from the preliminary pre-eliminating adjusting pulse Pph. In contrast, in the fourth embodiment, the preliminary charge-eliminating pulse Phe and the preliminary pre-eliminating adjusting pulse Pph are applied to the scanning and common electrodes 9 and 10 , respectively, with the preliminary charge-eliminating pulse Phe temporally overlapping the preliminary pre-eliminating adjusting pulse Pph.
[0191] [0191]FIG. 13 illustrates waveforms of light-emission found when the previous sub-field is selected, and the present sub-field is not selected. However, it should be noted that waveforms of light-emission remain unchanged regardless of whether the previous and present sub-fields are selected or not.
[0192] [Fifth Embodiment]
[0193] Hereinbelow is explained a method of driving a plasma display panel, in accordance with the fifth embodiment with reference to FIGS. 14 to 17 .
[0194] In a first example of the fifth embodiment, a positive preliminary pulse Pde is applied to the data electrode 6 at a timing at which the preliminary charge-eliminating pulse Phe starts being applied to the common electrode 10 , as illustrated in FIG. 14. The application of the preliminary pulse Pde to the data electrode 6 ensures generation of charge-eliminating discharge.
[0195] The preliminary pulse Pde is designed to have a pulse width equal to or smaller than a pulse width of the preliminary charge-eliminating pulse Phe. The preliminary pulse Pde is equal in voltage to the data pulse Pd.
[0196] In a second example of the fifth embodiment, a positive preliminary pulse Pde is applied to the data electrode 6 at a timing at which the preliminary charge-eliminating pulse Phe starts being applied to the scanning electrode 9 and the preliminary pre-eliminating adjusting pulse Pph starts being applied to the common electrode 10 , as illustrated in FIG. 15. The application of the preliminary pulse Pde to the data electrode 6 ensures generation of charge-eliminating discharge.
[0197] The preliminary pulse Pde is designed to have a pulse width in the range of 0.1 to 2 microseconds. The preliminary pulse Pde is equal in voltage to the data pulse Pd.
[0198] In a third example of the fifth embodiment, a positive preliminary pulse Pde is applied to the data electrode 6 at a timing at which the preliminary charge-eliminating pulse Phe starts being applied to the common electrode 10 , as illustrated in FIG. 16. The application of the preliminary pulse Pde to the data electrode 6 ensures generation of charge-eliminating discharge.
[0199] The preliminary pulse Pde is designed to have a pulse width in the range of 0.1 to 2 microseconds. The preliminary pulse Pde is equal in voltage to the data pulse Pd.
[0200] In a fourth example of the fifth embodiment, a positive preliminary pulse Pde is applied to the data electrode 6 at a timing at which the preliminary charge-eliminating pulse Phe starts being applied to the scanning electrode 9 and the preliminary pre-eliminating adjusting pulse Pph starts being applied to the common electrode 10 , as illustrated in FIG. 17. The application of the preliminary pulse Pde to the data electrode 6 ensures generation of charge-eliminating discharge.
[0201] The preliminary pulse Pde is designed to have a pulse width in the range of 0.1 to 2 microseconds. The preliminary pulse Pde is equal in voltage to the data pulse Pd.
[0202] Hereinbelow is explained the reason why charge-eliminating discharge is surely generated by applying the positive preliminary pulse Pde to the data electrode 6 .
[0203] Whereas the scanning and common electrodes 9 and 10 are arranged on a common substrate, the scanning and data electrodes 9 and 6 are spaced away from each other with a discharge spaced being sandwiched therebetween and in parallel with each other, and face each other in a large area. Hence, an electric field formed between the scanning and data electrodes 9 and 6 has uniform electric lines of force, as illustrated in FIG. 8.
[0204] Since the scanning and data electrodes 9 and 6 face each other in a large area, a ratio at which discharge is generated therebetween is high, and hence, generation of discharge is not so delayed. Accordingly, a voltage difference exceeding a voltage at which discharge is generated between the scanning and data electrodes 9 and 6 is hardly generated. Thus, weak discharge is more stably generated between the scanning and data electrodes 9 and 6 than weak discharge generated between the scanning and common electrodes 9 and 10 .
[0205] If cross-discharge is generated between the scanning and data electrodes 9 and 6 , ions and metastables are much generated in a discharge space, and hence, the discharge space is rendered into an active condition in which discharge is likely to be generated. Hence, surface-discharge is likely to be generated between the scanning and common electrodes 9 and 10 , ensuring generation of charge-eliminating discharge.
[0206] Though the above-mentioned first to fifth embodiments are applied to a case in which charges are not sufficiently eliminated by priming-eliminating discharge, the first to fifth embodiments may be applied to a case in which charges are not sufficiently eliminated by sustaining-eliminating discharge.
[0207] In the second embodiment, wall charges can be rearranged by the application of the preliminary pre-eliminating adjusting pulse Pph and charge-eliminating discharge can be stably generated by the application of the preliminary charge-eliminating pulse Phe. Hence, the second embodiment can generate charge-eliminating discharge more stably than the first embodiment.
[0208] The thick-width charge-elimination in accordance with the third embodiment makes it possible to generate charge-eliminating discharge more surely than the first and second embodiments.
[0209] In accordance with the fourth embodiment, it is possible to generate charge-eliminating discharge by applying a low voltage to the electrodes by virtue of self-elimination, and design the preliminary charge-eliminating pulse Phe to have a long pulse width. Accordingly, the fourth embodiment can eliminate wall charges more surely and stably than the third embodiment.
[0210] While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
[0211] The entire disclosure of Japanese Patent Application No. 2002-357517 filed on Dec. 10, 2002 including specification, claims, drawings and summary is incorporated herein by reference in its entirety. | A method of driving a plasma display panel including (A) a first substrate including a first electrode, and a second electrode extending in parallel with the first electrode and defining a display area with the first electrode therebetween, and (B) a second substrate including a third electrode facing the first and second electrodes and extending perpendicularly to the first and second electrodes, includes (a) applying a serrate voltage having an inclined waveform in which a voltage varies with the lapse of time, to the first and/or second electrodes, and (b) applying a preliminary charge-eliminating pulse voltage to the first and/or second electrodes after the a charge-eliminating discharge has been generated due to the serrate voltage, wherein the preliminary charge-eliminating pulse voltage eliminates electric charges only when electric charges have not been sufficiently eliminated. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to a telemetry system for communicating data related to parameters such as pressure, flow, temperature and other parameters in a wellbore through a drill stem or tubing string by generating stress waves or controlled vibrations in the tubing string in the wellbore and sensing the vibrations with strain gauges and/or accelerometers disposed on the tubing string at or near the surface.
2. Background
A problem of longstanding in the art of drilling, completing and servicing -oil and gas wells is the transmission of information from deep in the wellbore to the surface, such information including pressure, temperature, fluid flow rate, and other parameters desired to be measured at a particular point in the wellbore. During drilling operations it is also desired to be able to determine the actual weight on the drill bit, stresses in the drillstem and bit, bit rotational speed and related parameters.
In regard to transmitting data while drilling, various types of so-called telemetry systems have been developed including mud pulse type systems, electromagnetic systems and acoustic wave transmission systems. Certain shortcomings have been recognized in all of these systems with respect to the quality of the signal received at the surface. However, in pursuing the invention in my U.S. Pat. No. 4,715,451, assigned to the assignee of the present invention, it has been recognized that axial, torsional, and bending vibrations of a drillstem or tubing string at various frequencies and intensities can be sensed at a point at or near the surface with the utilization of high resolution strain gauges and accelerometers suitably mounted on the drillstem or tubing string. Based on experimentation and the development of measuring drillstem and tubing string loading and behavior utilizing the method and apparatus described in the above-mentioned patent, an improved telemetry system has been developed in accordance with the present invention which overcomes the shortcomings of prior art systems and is believed to be suitable for use in drillstems, tubing strings and other elongated tubing members oriented in a borehole and extending to depths of several thousand feet or on the surface along generally horizontal runs or courses, also over distances of at least several thousand feet.
SUMMARY OF THE INVENTION
The present invention provides an improved telemetry system and method for transmitting signals from a designated point in a drillstem or tubing string by generating controlled vibrations or stress waves in the tubing string which are transmitted along the tubing string and are sensed by means which convert the vibrations to usable data.
In accordance with one aspect of the present invention, there is provided a downhole vibration or stress wave generator which is controlled to operate at various frequencies or frequency phase shifts for transmitting vibrations along a drillstem or tubing string toward the end disposed at the surface. The vibration generator is preferably of a continuous vibration or wave generating type which is controlled to transmit a signal related to a selected one of parameters to be measured downhole such as fluid pressure, temperature, fluid flow rates and related information.
In accordance with another aspect of the present invention, there is provided means disposed at or near the surface for sensing the vibrations of the drillstem or tubing string and for generating signals related to such vibrations for transmission to a signal receiving and recording device whereby usable data related to the parameters to be measured may be obtained.
In accordance with still another aspect of the present invention, there is provided a data telemetry system characterized by one or more downhole members or subs which include sensing devices, signal conversion devices and preferably a microprocessor or computer for data storage and manipulation and for controlling the excitation of a vibrator, shaker or exciter apparatus generating controlled vibrations or stress waves for transmission along a tubular stem or string for receipt by vibration sensing devices connected to the tubing string and located at or near the surface. One embodiment of the invention contemplates the provision of a torsional and bending stress wave generator and another embodiment of the invention contemplates the provision of an axial stress wave generator or exciter.
The superior features and advantages of the invention described hereinabove as well as other aspects thereof will be further appreciated by those skilled in the art upon reading the detailed description which follows in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a vertical section view in somewhat schematic form of a system for telemetering downhole data through a drillstem during a drillstem testing operation;
FIG. 2 is a detail elevation of the upper end of the drillstem illustrated in FIG. 1 showing the arrangement of the stress wave or vibration measuring strain gauges/and accelerometers;
FIG. 3 is an elevation of a sub including sensing devices, signal converting electronics and related apparatus for the system of the present invention;
FIG. 4 is an elevation showing one embodiment of a stress wave generator or exciter in accordance with the present invention;
FIG. 5 is a vertical section view in somewhat schematic form of a tubing string equipped with an alternate embodiment of the stress wave telemetry system of the present invention:
FIG. 6 is a detail view of a wellhead such as that shown in FIG. 5 showing an axial compression wave sensing accelerometer; and
FIG. 7 is a section view of an axial compressional stress wave generator in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the description which follows, like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain features are shown in schematic form or in generalized form in the interest of clarity and conciseness.
The present invention contemplates the provision of a telemetry system particularly adapted for use in conjunction with drillstems during drillstem testing operations, for example, and in wellbore tubing strings for use during various well completion, servicing or stimulation operations. It has been determined that stress waves may be transmitted along elongated steel pipe or tubing strings as either axial compressional waves, which, in steel, have a velocity in the range of about 16,000 feet per second, or as torsional waves which have a velocity in the range of about 10,000 feet per second. By propagating these waves at selected frequencies or through phase shift keying along the drillstem or tubing string suitable signal transmission may be carried out from relatively deep locations in wellbores to or near the surface and sensed by accelerometers and strain gauges of a suitable type mounted on the drillstem or tubing string. The arrangement of accelerometers and strain gauges may be similar to those described in U.S. Pat. No. 4,715,451. The carrier signal transmitted along the drillstem or tubing string may be digitized and modulated by frequency or by phase shifting to indicate the binary states.
Referring to FIG. 1, for example, there is illustrated a wellbore 12 which has been drilled into an earth formation 14 and is prepared for so-called drillstem testing of a certain portion of the formation such as the region 13. In accordance with the general procedure in drillstem testing, an elongated drillstem or tubing string 16 is lowered into the wellbore 12 and having connected thereto suitable spaced apart packers 18 and 20 which are operated to pack off the portion of the wellbore 12 that penetrates the region 13. When the formation conditions existing in the region 13 are to be tested suitable subs 22 and 24 are interposed in the drill string 16 between the packers 18 and 20 and a third sub 26 is interposed in the drill string uphole of the packer 18. The drillstem 16 extends to a conventional drilling rig 28 and is suspended from a suitable swivel 30 in a conventional manner. The swivel 30 may be adapted to rotate the drillstem in a so-called top drive arrangement or the drillstem may be rotated during normal operation by a conventional rotary table drive 32. During the drillstem testing operation the drillstem 16 is not normally rotated substantially but only as required to operate certain apparatus associated with the testing functions. For example, the sub 24 may include suitable test ports for admitting wellbore fluid into the interior of the drillstem to be measured by certain sensor elements disposed in the sub 22. Various combinations of commercially available drillstem components utilized in drillstem testing operations may be incorporated in the sub 24 or otherwise interposed in the drillstem between the packers 18 and 20.
For the sake of discussion in connection with the present invention, the sub 22 may include certain sensing elements, an electrical energy source, conversion electronic circuits and a data acquisition and manipulation unit or computer. For example, referring to FIG. 3 the sub 22 is illustrated as including a central passage 23 extending therethrough for receiving fluid from the wellbore or, alternatively, from the drillstem. Suitable sensing elements such as a flowmeter 36, a pressure sensor 38, and a temperature sensor 40 are disposed on the sub 22 and suitably connected to electrical circuit means 42 for receiving the signals generated by the sensors and for converting the signals to a digital format for storage and manipulation by a suitable processor 44. The circuit means 42 and processor 44 are suitably disposed in an annular cavity formed in the sub 22 and isolated from the passage 23. Digital signals output from the processor 44 are transmitted to an intermediate sub 27, FIGS. 1 and 4, disposed in the drillstem below the sub 26.
Referring now to FIG. 4, the sub 27 is adapted to include suitable control circuitry for operating a stress wave generator associated with the sub 26 which circuitry is generally designated by the numeral 50. The sub 27 may also include a source of electrical energy such as a battery pack 52, which may also be disposed in the sub 26, space permitting. The sub 26 is modified to include a side pocket portion 54 having an interior space isolated from an axial passage 29 and adapted for supporting a stress wave generator or vibrator means characterized by spaced apart motor driven rotating eccentric members 56 and 58. Each of the rotor members 56 and 58 may be suitably driven by a rotary DC type brushless electric motor 60 which may be precisely and separately controlled to rotate the members 56 and 58, respectively, upon command from the control circuitry 50. By timing the rotational speed and phase relationship of the rotating members 56 and 58, certain torsional stress waves may be induced in the sub 26 and the drillstem 16 for propagation therealong to the surface and to a sub 64, FIG. 2, connected to the swivel 30. The axial spacing of the rotor members 56 and 58 also provides for inducing bending stresses in the drillstem 16 depending on the phase relationship and the spacing of the members 56 and 58. The particular arrangement of the components of the subs 26 and 27 permits the inclusion therein of the axial passageway 29 for the throughput of fluids, if desired.
Referring further to FIG. 2, the sub 64 is characterized by a transverse hub portion 68 which serves as a platform for supporting a plurality of high resolution accelerometers generally of the type described in U.S. Pat. No. 4,715,451. The accelerometers, designated by the numerals 70, 72, 74 and 76 are arranged such that their sensitive axes measure torsional and axial or bending vibrations of the drillstem 16. For example, the accelerometers 72 and 74 are arranged to sense motion in a plane normal to the axis 17 of the drillstem 16 and tangentially with respect to the axis. The accelerometers 70 and 72 are arranged to sense motion along the axis 17 in opposite directions and thus are also capable of sensing a bending vibration imposed on the sub 64. Axial and torsional stress waves being propagated along the drillstem 16 may also be sensed by an arrangement of strain gauges 78, 80, 82 and 84 similar to that described in the above-mentioned patent. Surface waves propagated along the drillstem 16 may be sensed by strain gauges 86 and 88. The signals from the strain gauges and accelerometers described above may be transmitted through suitable conductors to a receiver and recorder 90 or other suitable signal receiving and treating device if the drillstem is not required to be rotated. However, if the drillstem 16 is adapted for rotation during the drillstem testing operation or during other operations while stress waves are being transmitted from the sub 26, it is preferable to transmit signals to the receiver-recorder 90 by way of a radio link including a transmitter 92 which is supplied with power from a battery pack 94. A suitable circular receiving antenna 96 is supported in proximity to the transmitter 92 by a depending bracket 98 supported by the swivel 30. A suitable cover 100 is disposed over the devices mounted on the plate 68 and the sub 64.
The operation of the stress wave telemetry system illustrated in FIGS. 1 through 4 is believed to be understandable from the foregoing description, however, when it is desired to perform a drillstem test of the formation region 13 the drillstem 16 is made up to include the packers 18 and 20, and the subs 22, 24, 26 and 27. This drillstem configuration is then lowered into the wellbore 12 in a conventional manner using the drilling rig 28 and including the sub 64 interposed between the swivel 30 and the remainder of the drillstem. The sub 64 may, of course, be left connected to the swivel 30 during other operations such as contemplated by U.S. Pat. No. 4,715,451. When the drillstem 16 has been installed and the packers 18 and 20 set a formation test may be conducted by allowing the flow of fluid through at least the sub 22 through suitable admission ports in the sub 24, not shown. Fluid flow, pressure and temperature values are then sensed, converted to digitized form and either stored or transmitted to the control circuit 52 for operation of the vibrator means represented by the motor driven eccentric rotors 56 and 58 so that torsional vibrations, for example, can be transmitted through the drill string 16 at selected frequencies for sensing by the accelerometers 72 and 74, for example. If bending vibrations are induced in the drillstem through operation of the exciter or vibrator the accelerometers 70 and 76 are capable of sensing these bending vibrations and providing an output signal to the receiver-recorder 90 through the radio transmission link, for example.
Through experimentation with the transmission of vibrations in conventional steel drillstems and surface pipelines, it has been determined that for frequencies up to about 100 hz attenuation factors are near 1.0 (essentially no attenuation) and excellent correlations between transmission and receipt have been experienced for frequencies around 20 hz to 30 hz. It is contemplated that tubing strings or drillstems as long as 30,000 feet may be capable of transmitting data in this manner.
Referring now to FIGS. 5 through 7, there is illustrated in FIG. 5 an alternate embodiment of the present invention for installation in tubing strings disposed in a wellbore for various operations such as the injection of fluids during fracturing of a formation. As shown in FIG. 5, an earth formation 102 has been penetrated by a wellbore having surface casing 104 and bottom casing 106 set therein. The wellbore has been prepared for injection of fracturing fluids or stimulation fluids through perforations 108 into the wellbore region 103 by way of an elongated tubing string 110 extending within the casings 104 and 106. The tubing string 110 as well as the casings 104 and 106 terminates in a conventional wellhead 112, see FIG. 6 also, and the upper end of the tubing string has mounted thereon an accelerometer 116 adapted for measuring vibrations which propagate axially along the tubing string in the form of a compressional wave. The accelerometer 116 includes a conductor 117 which transmits an output signal to a receiver-recorder 120 similar to the receiver-recorder 90.
Referring further to FIG. 5, the tubing string 110 includes a suitable packer 122 for sealing off the portion of the wellbore into which fracturing or stimulation fluids are injected for flow through the perforations 108. Typically, the sub 22 or a similar sub, including suitable sensors, is interposed in the tubing string and adapted to include means for energizing a compression wave generator or vibrator 124 also interposed in the tubing string, preferably above the packer 122.
Referring to FIG. 7, one embodiment of a compression wave generator or vibrator means is illustrated which may be constructed as a part of a sub 125 interposed in the tubing string 110. The vibrator 124 includes the sub 125 and a tubular section 128 which are secured together at a pinned joint including a plurality of transverse pin members 130 which are adapted to secure the two members 125 and 128 together but allow slight bending movement of the sub 125 relative to the sub 128. An annular member 132 formed of magnetic material is disposed around the member 128 and is secured to a peripheral flange 134 of the member 125 by a plurality of circumferentially spaced axially extending pins or rods 136. A solenoid coil 138 is disposed on a nonmagnetic spool 140 and encapsulated in a suitable sealant and around the exciter member 132. Suitable resilient seal members 142 and 144 are also bound to the coil and to the members 125 and 128, respectively.
When the coil 138 is energized by current of reversing polarity at a selected frequency, the member 132 is axially oscillated at a corresponding frequency. In this way, axial vibrations are transmitted to the flange 134 and axially through the tubing string 110 as a compression wave at the selected frequency. The solenoid coil 138 is connected to a suitable source of energy at a selected frequency by conductor means 145 for excitation at a frequency corresponding to a selected datapoint or data set to be transmitted through the tubing string 110 to the accelerometer 116.
A sub 113, FIG. 5, is preferably interposed in the tubing string between the sub 22 and the vibrator 124 and includes a suitable electrical energy source, not shown, for exciting the vibrator, and a controlling circuit, also not shown, which may be similar to the circuit 52 for controlling the torsional vibrators in the sub 26. The sub 113 may also be adapted to include an onboard signal processing unit for storing and manipulating the digital data received from the sub 22. Accordingly, the system illustrated in FIGS. 5, 6 and 7 is operable also to transmit data through the tubing string using stress wave propagation, the primary difference being that in the embodiment of FIG. 5 the stress waves are axial compressional waves as compared with the torsional and bending waves used as the transmission signal of the system illustrated in FIGS. 1 through 4. Depending on the specific configuration of the tubing string, other types of vibrators or exciters may be utilized for generating either axial compression waves or torsional waves.
The operation of the embodiment of the stress wave telemetry system described in conjunction with FIG. 5 is also believed to be understandable to those of skill in the art from the foregoing description. Although preferred embodiments of a method and system in accordance with the present invention have been described herein, those skilled in the art will also recognize that various substitutions and modifications may be made without departing from the scope and spirit of the invention as recited in the appended claims. | Downhole conditions in wellbores such as fluid pressure, temperature and flow conditions during drillstem testing or during wellbore stimulation or fracturing processes are transmitted through sensing and signal conversion circuits to axial or torsional wave vibrators secured to a drillstem or tubing string in the borehole for generating stress wave vibrations in the drillstem or tubing string for transmission to a point at or near the earth's surface. Accelerometers and/or strain gauges are mounted on the stem or tubing at a point near the earth's surface for sensing the torsional, axial or bending vibrations and converting the vibratory signals to signals for receipt and recording and correlated with the signals being transmitted from the borehole. The system includes an axial compression wave generator comprising a solenoid energized oscillator hammer member disposed on a sub which may be interposed in the drillstem. A torsional wave vibration generator may be utilized comprising a sub having motor driven eccentric rotors which are driven in timed relationship to each other to generate selected torsional and/or bending stress waves in the drillstem or tubing string. | 4 |
PRIORITY CLAIM
This application is a divisional application and therefore claims priority of U.S. patent application Ser. No. 09/989,851, filed Nov. 19, 2001 now U.S. Pat. No. 6,619,733.
FIELD OF THE INVENTION
This invention relates generally to a headrest and, more particularly, to a passenger seat headrest platform.
BACKGROUND OF THE INVENTION
In contrast to passengers seated in a first class section of an airplane, train, bus, or other transport vehicles, passengers seated in economy class are more squeezed for space. This results in a more crowded and fatiguing trip for those passengers riding in economy class sections of airplanes, trains, buses, or other transport vehicles. Unlike first class, cramped economy class passengers do not have space to rest their heads in comfort or stretch to relax. Tired passengers in economy class often, sometimes unintentionally, rest their heads on the shoulder of adjacent passengers and fall asleep. A surprise awakening then occurs as the adjacent passenger nudges the sleeping passenger.
Given these cramped conditions, an economy class passenger can only bend forward to rest his or her head. Food trays, which drop from the back sections of forward seats, are deployed at lap level and are too low for resting one's head. Furthermore, the hard surfaces of food trays makes it difficult to comfortably rest one's head.
Cramped passengers need a means to sleep or rest in relative comfort while in a sitting position. Such a comfort level would be achieved similarly as when a person sits at a desk, leans forward, and rests his or her head and arms on the desk's surface. Thus, there is an unmet need in the art to provide passengers a similar option that allows them to slightly lean forward, and then place their heads and arms onto a padded rest deployed in a position higher than is possible with drop down, lap-deployed food trays, and at a passenger-selected inclination angle and height.
SUMMARY OF THE INVENTION
Three embodiments of the invention permit passengers to slightly lean forward and place their heads and arms onto a padded headrest deployed in a position higher than is possible with a drop down, lap-deployed food trays. Two embodiments allow the passenger to use a deployed padded headrest without being affected by the seatback recline adjustments made by a passenger sitting in forward seat. In another embodiment the deployed padded headrest is susceptible to seatback recline interference caused by a passenger seated in forward seat who proceeds to make seatback recline adjustments.
An embodiment not susceptible to recline interference is the sleep bar. The sleep bar serves as a back-of-the-neck headrest and a forward face-headrest. When in a neutral or undeployed position, the sleep bar is in a stowed position, essentially collinear with and secured into the passengers seat. In the stowed position, the sleep bar serves as a cushioned back-of-the-neck headrest for the passenger.
The sleep bar is a passenger headrest that is platform deployable and stowable from a passenger seat. The platform operates as a rear headrest and is pivoted to a forward position to serve as a forward leaning face-headrest. The headrest includes a headrest platform that is attached to an adjustable post made of tubular construction and having a plurality of holes. The adjustable post is concentrically dimensioned to be slidably received by a tubular bar. The tubular bar has a set of holes and is pivotably attached to the passenger seat. A first connector secures the adjustable post and tubular bar to each other. The headrest is pivotable through a range of motion adjusted by a passenger, wherein the passenger selects an inclination angle. The inclination angle used by the passenger is established via a second connector that secures the tubular bar to the seat.
When the sleep bar is moved forward from its stowed undeployed position, it can be pivoted to a comfortable inclination angle and elevation adjusted to the preferred height as desired by the passenger. It is then secured by various locking connectors (to secure the adjusted height) or clamping connectors (to secure the adjusted inclination angle) by the passenger to establish the passenger's preferred deployed position for the headrest platform. In the deployed position, the passenger slightly leans forward and rests his or her forehead or side of the head on the cushioned sleep bar headrest platform.
The cushioned sleep bar platform offers several advantages. It is integral to the passenger's seat and its stowed and deployed position is controlled specifically by the passenger. The passenger has the option to convert the sleep bar's back-of-the-neck headrest function to a forehead headrest function simply by deploying the sleep bar to a forward angle-adjusted and height-adjusted position. The cushioned sleep bar's inclination angle position is not affected by nearby forward sitting passengers as it is deployed from the seat of a sitting passenger who makes the inclination angle and height adjustments.
Another embodiment of the invention not susceptible to seatback recline interference is a single-toggle padded food tray which is deployed from the seatback of a forward sitting passenger. The single-toggle padded food tray provides two functions. One function is to provide a hard food-serving surface deployed at lap-level, the other function is to provide a forward face-padded headrest deployed at a passenger selected height and inclination angle similar in function to the sleep bar. The single-toggle padded food tray, though deployed from the rear seatback of a forward sitting passenger seat, is not affected by seatback recline interference because it pivots from a stationary section of the forward sitting passenger seat.
An embodiment that is susceptible to seatback recline interference is a dual-toggle padded food tray that is also deployed from the moveable seatback of a forward passenger seat. As with the single-toggle invention, the dual-toggle invention also provides a lap-level food-serving surface and a forward leaning chest-to-head level padded surface for face resting. Because the dual-toggle embodiment deploys from the non-stationary forward seatback, it is susceptible to seatback recline interference. The height and inclination angle selected by the passenger will vary slightly with the seat recline adjustments made by the forward seated passenger. Nevertheless, the dual-toggle invention offers many of the same advantages as the single-toggle invention and the sleep bar invention that are not susceptible to seatback recline interference. In the deployed position the dual-toggle provides a cushioned head-resting surface that can be initially adjusted to a passenger-preferred angle of inclination and height, and also provides a lap-level hard food-serving surface.
As will be readily appreciated from the foregoing summary, all embodiments of the invention provide a forward head-resting surface that can be adjusted to a passenger preferred height and inclination angle. Embodiments of the invention are readily ascertained from the following drawings and detailed descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
FIG. 1A is a side view of a passenger seat with sleep bar deployed in the forward face resting position with the sleep bar surface unfolded in a secured position;
FIG. 1B is a top view of passenger seat with sleep bar deployed in the forward face resting position with the sleep bar surface unfolded in a secured position;
FIG. 2A is a front view of passenger seat with sleep bar in stowed and folded closed position for back-of-the-neck or rear head resting position;
FIG. 2B is a side view of the passenger seat showing the folded sleep bar in the stowed (rear headrest) and deployed (face headrest) position;
FIG. 3 is a rear view of the passenger seat with sleep bar in the stowed and folded position;
FIG. 4A is a sleep bar assembly in folded rear headrest position;
FIG. 4B is a sleep bar height positioning locking mechanism;
FIG. 5 is an underside of sleep bar headrest platform in the open and locked position;
FIGS. 6A-D depict the operation of the single-toggle padded food tray;
FIG. 6A is an angled view of the stowed, single-toggle padded food tray with padded surface facing outward;
FIG. 6B is the deployed single-toggle padded food tray with hard surface facing up;
FIG. 6C depicts the lateral movement of the single-toggle padded food tray with hard surface face up, horizontal and lap-level;
FIG. 6D depicts pivotal movement of single-toggle padded food tray with padded surface pivoted into the top position;
FIG. 6E is the single-toggle padded food tray with the padded surface in the face up position being positioned for face head resting as selected by the passenger;
FIG. 7A is a side view that more closely shows the single-toggle padded food tray subjected to lateral movement;
FIG. 7B is a side view that more closely shows the single-toggle padded food tray subjected to pivotal movement;
FIGS. 8A, 8 B, and 8 C depicts the mechanical positioning of the extended bar stop into the single-toggle padded food tray slide cavity;
FIG. 9 depicts the tray arm to tray leg assembly which prevents forward sitting passenger recline tilt interference;
FIG. 10A displays the angular device positioning mechanism of the single-toggle padded food tray;
FIG. 10B depicts a magnified portion of the angular device positioning mechanism;
FIG. 11 shows the dual-toggle padded food tray in a stowed position in the seatback of tiltable seat;
FIG. 12 displays dual-toggle padded food tray in a lap level horizontal position showing the lateral movement of the tray;
FIG. 13 depicts an exploded view of the dual-toggle padded food tray in relation to seatback;
FIG. 14 more details of the internal structures of the comfort pad secured to the vertically stowed food tray; and
FIGS. 15A, 15 B, and 15 C depicts the deployment of the comfort pad of the dual-toggle padded food tray assembly.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment free of forward seated passenger recline interference is shown in FIGS. 1A and 1B. A sleep bar 10 serves as a rearward and face-ward padded headrest. Operational utility of the sleep bar 10 is depicted in FIG. 1 A. Here a sleeping passenger in passenger seat 12 is able to sleep in a forward headresting position A—A on a deployed sleep bar platform 14 . The position of the sleep bar 10 is totally under control by the passenger. Extension or height is controlled by adjustable post 16 that slides along inner post 17 . The angle of the sleep bar is adjusted through a pivoting point 18 . FIG. 1B shows the top view of the operational utility of the sleep bar. Here the passenger is resting on the sleep bar platform 14 that is deployed in a forward head resting position A—A and held in position by adjustable post 16 and a clamping means near point 18 . The plurality of configurations for the sleep bar 10 is depicted in FIGS. 2A and 2B.
FIG. 2A shows a view of the passenger seat 12 with the stowed sleep bar 10 . Headrest 22 is on the top of the passenger seat 12 . The folded headrest platform 22 is stowed in a vertical position parallel to the spine of the passenger seat 12 . The folded headrest platform 22 is supported by adjustable post 16 secured by a locking means to inner post 17 . The inner post 17 resides aft to armrest 24 . FIG. 2B is a side view that represents possible configurations, angles, and adjustment extensions or heights from the folded stowed position 22 to the deployed position 14 depicted inside armrest 24 . The folded platform 22 is in pillow configuration to the passenger seat 12 . Vertical headrest 22 is attached to adjustable post 16 that is secured to inner bar 17 . The forward angle of the sleep bar 10 is controlled through pivot point 18 in which the vertical sleep bar 10 is unfolded at position 14 in the forward position to any angle preferred by the seated passenger.
The relation of the folded sleep bar 10 to other components of the seat 12 is described in rear view FIG. 3. A conventional food tray 32 with leg supports 34 is shown in a stowed position. Here the folded headrest platform 22 rests on top of the passenger seat 12 secured by adjustable post 16 . Inner bar 17 is internal to armrest 24 and is turned along pivoting axis 36 .
Adjustment of height of the sleep bar is shown in FIG. 4 A. In adjustable post 16 resides a plurality of positioning holes 42 which are linearly aligned. Similarly, there resides near the upper end on inner bar 17 a securing hole 45 . As adjustable post 16 slides along inner post 17 the bar height is locked into position as the positioning holes 42 of adjustable post 16 aligns with components of a positioning post locking mechanism (not shown), near view line B—B, and the upper end hole of inner bar 17 . Inner bar 17 has a pivot hole 46 wherein inner bar 17 is secured to the passenger seat via a bolt or equivalent connector.
FIG. 4B is a cross-sectional view of axial view B—B showing a depiction of the positioning post locking mechanism 49 . The extension or height of the sleep bar 10 is affected as the hollow adjustable post 16 is slid along hollow, inner post 17 , causing an alignment of positioning holes 42 with securing hole 45 . When this alignment occurs, a spring-loaded cylinder 47 pushes a positioning peg 48 through the aligned securing hole of inner bar 17 and positioning hole 42 of outer positioning post 16 . The positioning peg 48 is flanged to prevent its expulsion from the positioning post locking mechanism 49 . Once the sleep bar 10 is adjusted to a passenger-preferred height, it is pivoted into an angled position for forward sleeping.
FIG. 5 shows how the sleep bar 10 is unfolded. Along pivoting access 52 the two halves of the platform pads 55 are opened and reveal two hidden positioning switches, 56 and 57 , which are used to secure the two padded halves 55 into a locked open and unfolded position. Positioning switches 56 and 57 are pivoted into an engaged position 58 and 59 . Positioning switch 56 rotates in recess 53 and positioning switch 59 rotates in recess 54 . The unfolded deployed sleep bar 10 is shown attached to positioning post 16 .
Another embodiment of the invention independent of forward passenger recline interference is the single-toggle padded food tray 62 which contains a hard food-serving surface and a padded, pillow like surface 66 . The single toggle padded food tray is secured into a recess of a seatback with a toggle latch 61 engaged against a catch of the food tray. The toggle latch 61 can be rotated to engage or disengage the catch of the food tray. As shown in FIG. 6A, seat 60 contains a stowed single-toggle padded food tray 62 secured by a toggle 61 and tray legs 63 . As shown, the padded surface 66 is stowed vertically, secured by toggle 61 engaged against the food tray latch (not shown). As toggle 61 is rotated as indicated in FIG. 6B, a conventional food tray is pivoted about tray legs 63 downward to lap level with the hard surface 64 face up in a deployed position. In side view FIG. 6C, the hard surface 64 is face up and the padded surface 66 is face down. As lateral motion is applied to the single-toggle padded food tray 62 towards the passenger, tray arm 67 is partially revealed. Then, as depicted in FIG. 6D, the single-toggle padded food tray is rotated until it reaches a tray stop. Padded surface 66 is now in an angled and upwardly deployed position for use by the passenger. Finally, as depicted in FIG. 6E, the passenger preferred angle of rotation for using the single-toggle padded food tray 62 is then secured with the padded surface 66 face up. The tray 62 latch 65 displaced from toggle 61 .
FIGS. 7A and 7B depict how the single-toggle padded food tray 62 is subjected to horizontal and pivotal motion. In FIG. 7A, depressing catch 71 allows passenger to extend lateral movement of tray 62 , revealing tray arm 67 . The single-toggle padded food tray 62 is pulled toward the passenger along tray arm 67 that is attached to tray legs 63 via the tray arm pivots 70 . As the passenger continues to pull the single-toggle padded food tray closer to the passenger as shown in FIG. 7B, tray forearms 73 are partially revealed. The remainders of the tray forearms 73 are still inside the single-toggle padded food tray slide cavity as indicated by the dashed lines. The passenger is then able to pivot the single-toggle padded food tray 62 about the forearm pivot 72 attached to tray arm 67 , which is in turn connected to the tray legs 63 via the tray arm pivots 70 . The pivotal rotation continues until the beveled tray stop surface 74 of the tray forearm 73 engages against the upper ridge of tray arm 67 , located above latch 71 .
FIGS. 8A, 8 B, and 8 C describe the mechanical relationship of how the extended bar stop 81 fits into the single-toggle padded food tray slide cavity. In FIG. 8A, the extended bar stop 81 includes the tray arm 67 in linear alignment with the tray forearm 74 connected via the forearm pivot 72 . On the tray forearm 73 resides a tray catch 82 . In FIG. 8B, the extended bar stop 81 is then inserted into the single toggle padded food tray's 62 tray slide cavity 86 whereupon the tray catch 82 engages into cavity clip 84 . Padded surface 66 is shown face down. FIG. 8C shows a partial cross-sectional view of the single-toggle padded food tray 62 wherein the tray slide cavity 86 contains the cavity clip 84 located on the side of the slide cavity 86 which is in turn interior to the food service tray 62 . The cushioned comfort pad 66 is shown facing downward.
FIG. 9 depicts how the tray arm to tray leg assembly is prevented from forward sitting passenger recline tilt interference. To the tray leg 63 is attached the tray arm 67 which has an arm follower pin 90 which slides within pin slot cavity 91 . Tray arm 67 is secured to the companion tray arm via an interconnecting tie rod 94 that is secured to the tray arm 67 with a tie rod securing screw 95 engaged at each end of the tie rod 94 inserted through each companion tray arm 67 . Tray legs 67 are distally connected to bottom of forward passenger seat separated from the tilting seatback. The pivotal motion of tray arm 67 about the tray leg 63 occurs when following pin 90 slides within pin slot cavity 91 as the tray arm 67 is pivoted about tray arm pivot 70 .
FIGS. 10A and 10B displays the angular device positioning mechanism 99 of the single-toggle padded food tray. FIG. 10A depicts the arrangements of parts of the complete positioning mechanism 99 wherein ray arm 67 with latch 82 is shown articulated to tray forearm 73 via forearm pivot 72 . On tray forearm 73 is tray catch 62 . As shown in FIG. 10B, the pivotal motion of tray forearm 73 is stopped as the beveled tray stop surface 74 engages against the upper ridge of tray arm 67 .
Another embodiment similar to the single-toggle padded food tray is the dual-toggle padded food tray. The dual-toggle padded food tray is similarly a comfort padded food tray and food tray assembly, which is attached to the forward passenger seatback via a tray leg pivot. Though the dual-toggle padded food tray offers similar service tray and sleeping surface functionality, because it is pivotally deployed directly from the forward sitting passenger seatback, the dual-toggle padded food tray is subject to recline tilt interference.
FIG. 11 shows the dual-toggle padded food tray 114 in a stowed position in the seatback of forward sitting passenger seat 110 where the padded surface 116 is facing outward. In the stowed position are visible two toggle latches. The upper toggle latch is the food tray toggle latch 112 secured by food tray toggle catch 113 and the lower toggle latch is the comfort pad toggle latch 118 secured by catch 124 . Dual-toggle padded food tray 114 is secured by pivoting about tray legs 120 .
In FIG. 12, the food service tray 114 from seatback 110 is shown in a deployed position through pivots. As toggle latch 112 is pivoted clear from catch 113 , the food service tray 114 falls with gravity to lap level as it pivots through tray pivots 128 securing tray bayonets 122 to tray legs 120 . Tray legs 120 are attached to tiltable seatback 110 via seatback and tray leg pivots 111 .
FIG. 13 depicts an exploded view of the dual-toggle padded food tray 114 in seatback 110 . Internal structures include slots 132 , hinge 134 , and pivot link 136 . Toggles 112 and 118 are shown in an engaged vertical position. Dual-toggle padded food tray 114 is shown directly projecting from tray bayonets 122 , which in turn are connected to tray legs 120 . Padded surface 116 contains two spring-loaded slide pins 130 , located at the top end of padded comfort rest 116 .
FIG. 14 depicts more details of the internal structures of the padded surface 116 wherein two spring-loaded pins 130 are shown for reference. The planar design of the pivot link 136 imparts stability to the padded-surface when deployed to prevent wobbling and is secured to the internal side via a comfort pad hinge 140 .
FIGS. 15A, 15 B, and 15 C depict the deployment of the outward facing comfort pad of the dual-toggle padded food tray 114 from seatback 110 to a passenger use position. In a side view shown in FIG. 15A, the dual-toggle padded food tray 114 is stowed into seatback 110 with padded surface 116 facing outward towards the passenger. As shown in side view of FIG. 15B, as lower toggle latch 118 is rotated, the comfort pad 116 falls downward with gravity with the spring-loaded pivots 130 sliding in slots 132 . The angled comfort pad 116 is then secured via the pivot link 136 . Pivot link 136 is shown secured to tray 114 with padded surface 116 angled face up. FIG. 15C shows an angular view where the comfort pad is secured in a face-resting position from seatback 110 .
While the preferred embodiments of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. | A passenger headrest is platform deployable and stowable from a passenger seat. The platform operates as a rear headrest and is pivoted to a forward position to serve as a forward leaning face-headrest. The headrest includes a headrest platform that is attached to an adjustable post made of tubular construction and having a plurality of holes. The adjustable post is concentrically dimensioned to be slidably received by a tubular bar. The tubular bar has a set of holes and is pivotably attached to the passenger seat. A first connector secures the adjustable post and tubular bar to each other. The headrest is pivotable through a range of motion adjusted by a passenger, wherein the passenger selects an inclination angle. The inclination angle used by the passenger is established via a second connector that secures the tubular bar to the seat. | 1 |
FIELD OF INVENTION
The present invention relates generally to shingle cutters, and is more particularly directed to a portable, pneumatically operated shingle cutter capable of cutting multiple shingles in a single operation into a form suitable for roof-cap.
BACKGROUND OF INVENTION
Typically, roof-cap is manually cut from shingles by way of a utility knife. This job is time consuming, and depending upon the skill of the worker, may produce nonuniform pieces and substantial waste-product. Several machines have been proposed as described hereinafter; however, due to small gains in productivity, such machines have not been widely accepted or utilized.
U.S. Pat. No. 5,052,256 to Morrissey et al. discloses a shingle cutting apparatus including a base and a lever arm with a pair of diverging cutting blades mounted thereon. A pair of grooves are provided on the base corresponding to the cutting blades to facilitate cutting. The blades are angled so that the cutting apparatus cuts shingles into a six sided shape suitable for roof-cap. The apparatus of the '256 patent is designed to cut one shingle per operation and is hand-activated.
Another hand-activated shingle cutter is disclosed in U.S. Pat. No. 4,951,540 to Cross et al. The shingle cutter described in the '540 patent includes a pair of fixed blades on the base as well as a pair of movable blades mounted on a lever arm. In operation, a shingle is manually positioned along an edge of the base and cut to a combined trapezoidal/rectangular shape suitable for use as roof-cap.
Other vintage shingle-cutting devices and methods are disclosed in U.S. Pat. Nos. 2,779,325 to Beckham; 1,981,695 to Gundlach: 1,906,599 to Hoffert; and U.S. Pat. No. 1,665,600 to Mortimer. Like the devices of the '540 and '256 patents described above, the foregoing patents are generally directed to manually cutting one shingle per operation and are exceedingly labor-intensive as are cutting or punch devices such as those generally known, for example:
the "Card File Punch" of Merrick et al. disclosed in U.S. Pat. No. 4,869,143;
the "Siding Cutter" of Green et al. shown in U.S. Pat. No. 4,510,834;
the "Mat Cutting Machine" of Broides, U.S. Pat. No. 3,779,119; and
the "Trimming Device" of Nielsen described in U.S. Pat. No. 2,090,548.
A portable shingle cutter capable of cutting multiple shingles in a single operation while maintaining uniformity between pieces such as that of the present invention significantly increases production capability as well as maintains the quality of the end-product.
SUMMARY OF INVENTION
In accordance with the present invention, there is provided an apparatus for cutting a stack of multi-tabbed shingles into portions useful as roof-cap in a single cutting operation. The same is accomplished by way of a movable cutting plate with a plurality of cutting edges, a base plate provided with a plurality of cutting edges and means for positioning a stack of shingles therebetween. During a cutting operation, the shingles are in contact with the positioning elements of the apparatus so that there is no slippage and the cutting operation results in uniform product. Preferably, the apparatus is pneumatically powered and the stack of shingles is positioned by utilizing posts with fit securely into the tab-slot of the shingles.
BRIEF DESCRIPTION OF DRAWINGS
The invention is described in detail below with reference to the various figures wherein like numerals designate similar parts and in which:
FIG. 1 is a plan view of a typical 3-tabbed shingle;
FIG. 2 is a plan view of a hexagonal cut-out suitable for use as roof-cap produced from the 3-tabbed shingle of FIG. 1;
FIG. 3 is a perspective view of an apparatus constructed in accordance with the present invention;
FIG. 4 is a view in elevation of the apparatus of FIG. 3;
FIG. 5 is a plan view of a base plate useful in connection with the apparatus of FIGS. 3 and 4;
FIG. 6 is a detail of a punch which is mounted on a punch plate as shown in FIG. 4;
FIG. 7 is a detail of a base plate of the type shown in FIGS. 3, 4, and 5; and
FIG. 8 is a schematic illustration of the cooperation of a punch and base plate in accordance with the present invention.
DETAILED DESCRIPTION
The following illustrations and examples are provided for purposes of exposition and not limitation. One of skill in the art will readily appreciate that modification, improvement and embodiments other than shown here are possible. Likewise, terminology is selected for convenience and should be interpreted in the context and spirit hereof. For example the present invention is specifically described in terms of a movable plate and a base plate. Such language refers to relative motion only and that such language includes a pair of mutually hinged, opposing plates.
Turning to the figures, there is shown in FIG. 1 a typical 3-tabbed roofing shingle, commonly used in residential applications. Shingle 1 has an upper portion 3 as well as 3 tabs, 5, 7, and 9 respectively defining between them a pair of slots 11, 13. It is an object of the present invention to cut shingle into three smaller portions, such as that shown in FIG. 2. FIG. 2 is a plan view of a portion of shingle 1 having 6 sides 15, 17, 19, 20, 21 and 23 such that it is hexagonal in geometry, as shown. This shape, among others, is suitable for roof-cap; the shape illustrated being generally most preferred.
The cutting operation, that is getting from shingle 1 to portion 25 is accomplished by way of inventive apparatus 30 of FIG. 3. In accordance with the present invention, apparatus 30 has a base plate 32 and a movable upper cutting plate 34. Plate 34 has a plurality of cutting blades 36, 38, 40, 42, 44 and 46 mounted thereon, all forming an acute angle with edge 48 of plate 34 so that the required cuts can be made. Base plate 32 has a series of openings 50, 52, 54 and 56 which have cutting edges 58, 60, 62, 64, 66 and 68 corresponding to blades 36, 38, 40, 42, 44 and 46 of plate 34. In operation, the various cutting edges cooperate to cut a shingle, such as shingle 1 into 3 portions such as portion 25.
Plates 32, 34 are supported on a frame 70 including a bridge portion 72 and a base portion 74. A pair of actuating cylinders 76, 78 are mounted atop bridge portion 72 upon which plate 32 is reciprocally mounted. Cylinders 76, 78 are preferably 4 stroke, 1.5" bore, however any suitable working cylinder may be used so long as it generates sufficient force. Pneumatic cylinders may be preferred, however a hybrid pneumatic/hydraulic system may in some circumstances be superior. Both types of systems are referred to herein as "pneumatic" for purposes of convenience. Cylinders 76, 78 are connected to a high pressure reservoir 80 which in turn is connected to a compressor 82. Compressor 82 is of the portable type having a maximum output of about 150 psig, and apparatus 30 is preferably constructed so that it will operate satisfactorily at such pressures.
Base plate 32 is further provided with a pair of positioning posts, 84, 86 the salient features of which are discussed further hereinafter. Suffice it to say for present purposes, that during operation of apparatus 30, posts 84, 86 receive the slots, such as slots 11 and 13 of shingle 1, of a plurality of shingles to be cut into smaller portions for roof-cap.
Design details and operation of the inventive apparatus 30 are illustrated and explained with reference to FIGS. 4 through 8. FIG. 4 is a side view in elevation of apparatus 30 of FIG. 3, wherein like parts bear like numerals for identification. Upper blades 36, 38, 40, 42, 44 and 46 are mounted on four angular punches 88, 90, 92 and 94 secured to plate 34. Plate 34 is reciprocally mounted on a bridge 72 so that punches 88, 90, 92 and 94 are reciprocally opposed to openings 50, 52, 54 and 56 in plate 32, as shown in FIG. 4. The upper blades 36-46 may be integrally formed on the punches 88-94 or may be detachably secured thereto. The openings 50-56 are preferably in the form of relief in plate 32, as illustrated in 5, which is a plan view of apparatus 30 with bridge 72 removed, that is, along with upper plate 34 and the actuating cylinders.
Plate 32 is desirably mounted on a lower frame 74 which is operative as a side guide and is preferably provided with a plurality of slots, 96, 98 so that its axial position relative to plate 34 is adjustable.
Most preferably, the punches 88-94 and corresponding upper cutting blades 36-46 are provided with a pitch of inclination relative to the plate surface as shown in FIG. 6. That is, the upper cutting blades project more outwardly from plate 34 at one of their terminii with a pitch, for example, towards the apexes 100, 102, 104, 106 of openings 52-56 where the cut is made last. Thus a punch 90 and corresponding blades 38, 40 are thickest at the base of triangular portion 50, at 108 shown in FIG. 6. The pitch is mostly preferably inwardly directed so that a shingle is urged against a post, such as post 84 when cut. The pitch may be at any angle 110 from about 5 to about 20 degrees; about 10 degrees being most preferred. If an inward pitch is unnecessary, an outward pitch will likewise be preferable to a cutting blade parallel to the surface of plate 34.
Turning to FIG. 7, there is shown in schematic form a portion of lower plate 32. There is additionally provided however, removable inserts 112, 114 which are used as the lower cutting blades, such as blades 58-68. Inserts 112, 114 may be made of any suitable material, preferably of hardened steel. There is shown in FIG. 8 a punch 90 (with an outward pitch) as it would cooperate with base plate 32 to cut a plurality of shingles.
Due to the unique construction of the apparatus of the present invention, it is possible to stack multiple shingles on the lower plate 32 about posts 84, 86 so that at least 6 and up to one dozen shingles can be cut into roof-cap in a single operation. Moreover, since the positioning depends only upon the slots, such as slots 11, 13 the inventive apparatus can be readily adapted to cut shingles of even non-uniform size.
The invention has been described hereinabove in detail and is thus illustrated throughout the various figures. Further illustration is believed unnecessary. Modifications within the spirit and scope of the present invention will be apparent to those of skill in the art. Accordingly, the present invention is limited and defined only by the appended claims. | An apparatus for cutting each of a plurality of multi-tabbed shingles into smaller portions useful as roof-cap is disclosed and claimed. The apparatus includes upper and lower cutting plates mounted in reciprocating opposed spacial relationship. Preferably, the apparatus is pneumatically powered and it is possible to cut multiple shingles in a single operation. | 4 |
BACKGROUND OF THE INVENTION
The present invention generally relates to a thin film forming method and system, and more particularly to a thin film forming method and system suitable for fabricating a disk-shaped recording media provided in a disk storage device frequently used as an external storage device of a data processing device.
A disk storage device is widely used in a computer system. Particularly, a magnetic hard disk has a large storage capacity. A magnetic hard disk has a disk-shaped base having thin films made of a magnetic material on both sides thereof. In order to obtain uniform characteristics of thin films on each disk-shaped base, it is particularly necessary to uniformly grow the thin films on both the sides of the disk-shaped base. In addition, it is necessary to produce magnetic hard disks having almost the same characteristic in commercial quantity.
The growth of the thin films on the disk-shaped base by use of a vacuum apparatus depends on various film growth conditions, such as the temperature of the disk base, the film growth pressure, the amount of flowing a gas and the attainability of vacuum. Particularly, the characteristics of thin films are greatly affected by the temperature of the disk base.
A conventional thin film forming system (manufactured by, for example, NICHIDEN ANERUBA, Japan) has a heating means, such as a lamp heater, for heating disk bases so that the temperatures of the disk bases are maintained at a predetermined temperature. Normally, a group of a plurality of disk bases held by a holder is heated together by the lamp heater and then inserted into a vacuum room of the vacuum apparatus. Then, a thin film growing process is carried out for the disk bases of the same group one by one. Thus, the temperatures of the disk bases obtained when the sputtering process is respectively carried out for the disk bases one by one are greatly different from each other. The above fact causes differences of characteristics of the magnetic disks.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved thin film growing method and system in which the aforementioned disadvantages are eliminated.
A more specific object of the present invention is to provide a thin film growing method and system in which the temperature of each disk base obtained immediately before a film growing process is carried out one by one is regulated at an almost identical temperature, so that storage disks having almost the same characteristics can be produced in commercial quantity.
The above-mentioned objects of the present invention are achieved by a thin film forming method comprising the steps of:
(a) preheating a plurality of base plates placed at a first position;
(b) sequentially picking up said base plates one by one and positioning a picked-up base plate at a second position;
(c) heating said picked-up base plate at said second position so that a temperature of said picked-up base plate becomes approximately equal to a predetermined temperature;
(d) moving said picked-up base plate from said second position to a third position; and
(e) growing a thin film on a surface of said picked-up base plate at said third position.
The aforementioned objects of the present invention are also achieved by a thin film forming system comprising:
first heating means for preheating a plurality of base plates placed in a first room;
pick up means for sequentially picking up the base plates one by one and for placing a picked-up base plate at a predetermined waiting position in the first room;
second heating means for heating the picked-up base plate at the predetermined waiting position;
temperature measuring means for measuring a temperature of the picked-up base plate at the predetermined waiting position;
control means for controlling the temperature measuring means so that the temperature of the picked-up base plate measured by the temperature measuring means becomes approximately equal to a predetermined temperature;
moving means for moving the picked-up base plate from the predetermined waiting position in the first room to a second room; and
thin film forming means for growing a thin film on a surface of the picked-up base plate in the second room.
The aforementioned objects of the present invention are also achieved by a thin film forming system comprising:
conveyer means for transporting a holder holding a plurality of base plates to a first room;
first heating means for heating the plurality of base plates held by the holder so that temperatures of the base plates respectively become approximately equal to a first predetermined temperature;
first arm means for picking up the base plates from the holder one by one and for successively placing, one by one, the base plates at a predetermined waiting position in the first room;
temperature measuring means for measuring the temperature of one base plate at the predetermined waiting position;
second arm means for receiving the one base plate at the predetermined waiting position and for placing the one base plate in a second room close to the predetermined waiting position;
second heating means, provided near the predetermined waiting position, for heating the one base plate at the predetermined waiting position;
control means, coupled to the temperature measuring means and the second heating means, for controlling the second heating means on the basis of the temperature of the one base plate measured by temperature measuring means so that the temperature of the one base plate becomes approximately equal to a second predetermined temperature; and
thin film forming means for growing a thin film on a surface of the one base plate placed by the second arm means.
The aforementioned objects of the present invention are also achieved by a thin film forming system comprising:
first heating means for preheating a plurality of base plates placed at a first position;
pick up means for sequentially picking up the base plates one by one and positioning a picked-up base plate at a second position;
second heating means for heating the picked-up base plate at the second position so that a temperature of the picked-up base plate becomes approximately equal to a predetermined temperature;
moving means for moving the picked-up base plate from the second position to a third position; and
thin film forming means for forming a thin film on a surface of the picked-up base plate at the third position.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram illustrating the entire structure of a double side continuous sputtering system according to a first preferred embodiment of the present invention;
FIG. 2 is a perspective view of the double side continuous sputtering system shown in FIG. 1;
FIG. 3 is a perspective view illustrating an inner structure of a loading chamber and an inner structure of a sputtering chamber shown in FIGS. 1 and 2;
FIG.4 is a perspective view of a holder shown in FIGS. 1, 2 and 3;
FIG. 5 is a schematic side view of the sputtering chamber shown in FIGS. 1 through 3;
FIG. 6 is an enlarged perspective view illustrating a state where a disk base is waiting for a sputtering process;
FIG. 7 is a diagram illustrating the entire structure of a double side continuous sputtering system according to a second preferred embodiment of the present invention; and
FIG. 8 is a graph illustrating an advantage presented by the invention, compared to a prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description will be given of a first preferred embodiment of the present invention.
Referring to FIGS. 1 and 2, a double side continuous sputtering system is composed of a loading chamber (LC) 100, a sputtering chamber (SC) 200 and an unloading chamber (ULC) 300. An input transport conveyer 50 transports a holder 20, which holds a plurality of disk bases 1 (20 disk passes, for example). Each of the disk bases 1 has two opposite surfaces on which thin films are respectively formed by sputtering. An opening and shutting door 70 is provided at an interface between the loading chamber 100 and the sputtering chamber 200. Similarly, an opening and shutting door 80 is provided at an interface between the sputtering chamber 200 and the unloading chamber 300.
The disk bases 1 held by the holder 20 are inserted into the loading chamber 100 through a holder insertion opening 125 formed on a front surface of the loading chamber 100. A lid 120 is provided for the holder insertion opening 125. After the holder 20 is inserted into the loading chamber 100, the lid 120 is closed so that it totally covers the holder insertion opening 125 and thus an inner room of the loading chamber 100 is hermetically sealed.
Referring to FIG. 3 in addition to FIGS. 1 and 2, a lamp heater 110a having a plurality of heating elements is provided at an upper portion of the loading chamber 100, and a lamp heater 110b having a plurality of heating elements is provided at a lower portion of the loading chamber 100. The lamp heaters 110a and 110b heat (preheat) the disk bases 1 held by the holder 20 so that each of the disk bases 1 has a predetermined temperature equal to, for example, about 210° C. The lamp heaters 110a and 110b also function to remove an impurity gas emitted from the disk bases 1 and moisture.
The loading chamber 100 has a transport conveyer 130 provided for transporting the entire holder 20 to the sputter chamber 200. Further, the loading chamber 100 has a cryopump 140. After the lid 120 is closed, the cryopump 140 starts to exhaust air toward the outside of the loading chamber 100 so that the inner room of the loading chamber 100 has a degree of vacuum almost equal to that of an inner room of the sputter chamber 200. During this operation, the opening and shutting door 70 is maintained in the closed state.
Then, the opening and shutting door 70 is opened. The transport conveyer 130 transports the holder 20 to the sputtering chamber 200 through an opening formed by opening the opening and shutting door 70. After the holder 20 is inserted into the sputtering chamber 200 and placed on a tray 20a (FIG. 3) on a transport conveyer 205, the opening and shutting door 70 is closed. Then, a leaf valve 150 (FIG. 2) mounted on a back surface of the loading chamber 100 is opened, so that the pressure of the inner room of the loading chamber 100 becomes equal to atmosphere pressure. After that, the lid 120 of the loading chamber 100 is opened and thus the loading chamber 100 is ready to receive a next set of disk bases 1 held by the holder 20.
As shown in FIG. 3, the sputtering chamber 200 has a lamp heater 210a having a plurality of heating elements, and a lamp heater 210b having a plurality of heating elements. The lamp heater 210a is provided at an upper portion above the transport conveyer 205a, and the lamp heater 210b is provided at a lower portion of the transport conveyer 205a. The lamp heaters 210a and 210b function to heat (preheat) the disk bases 1 held by the holder 20 and the transport conveyer 205 so that they are set to a predetermined temperature equal to, for example, 210° C. The lamp heaters 210a and 210b also function to remove an impurity gas emitted from the disk bases 1 and moisture.
A thermocouple 212 is provided in the vicinity of the lamp heater 210a, as shown in FIG. 3. Similarly, a thermocouple 112 is provided in the vicinity of the lamp heater 110a of the loading chamber 100. The thermocouples 112 and 212 are connected to a controller 400 (FIG. 1), which controls the entire system including a procedure for measuring the temperature of an area near the lamp heater 112 and the temperature of an area near the lamp heater 212. The controller 400 is formed of, for example, a microcomputer.
Referring to FIG.4, there is illustrated the holder 20. The holder 20 has three shafts 21, 22 and 23. A plurality of grooves 20g are formed around each of the shafts 21, 22 and 23. A circumferential end portion of each disk base 1 engages with the corresponding grooves 20g of the three shafts 21, 22 and 23. The sputtering chamber 200 is provided with two cryopumps 240 (FIG. 2).
As shown in FIG. 1, the sputtering chamber 200 is divided into a transport room 201 and a sputtering room 202. The aforementioned transport conveyer 205 and the lamp heaters 210a and 210b are provided in the transport room 201. In the sputtering room 202, a magnetic thin film such as an α-Fe 2 O 3 film, is grown on each of the opposite surfaces of each disk base 1. As shown in FIG. 1, two targets 203a and 203b are disposed on both sides of the disk base 1 placed in the sputtering room 202. The targets 203a and 203b are sputtered, and thus α-Fe 2 O 3 thin films are formed on the surfaces of the disk base 1.
As shown in FIG. 5, a handling arm 220 is provided in the transport room 201. The handling arm 220 is used for picking up the disk bases 1 held by the holder 20 one by one. The handling arm 220 is rotatable around a center shaft 220a, as indicated by the arrow shown in FIG. 5. When the handling arm 220 is positioned at a sputtering waiting position indicated by a character P, a sputtering arm 230 rotatable around a center shaft 230a accesses the disk base 1 positioned at the sputtering waiting position P, and holds inner circumferential portions of the disk base 1. In this way, the disk base 1 is passed from the handling arm 220 to the sputtering arm 230.
The sputtering arm 230 has chucking mechanisms respectively provided on both ends thereof. FIG. 6 illustrates a chucking mechanism provided at one end of the sputtering arm 230. The chucking mechanism shown in FIG. 6 has a sputtering chuck 232, which holds the disk base 1 on both sides thereof. While the disk base 1 is being rotated by the chucking mechanism on one side of the sputtering arm 230 and being subjected to the sputtering process, the chucking mechanism on the other side thereof receives the disk base 1 from the handling arm 220. With the above-mentioned configuration, it is possible to successively move the disk bases 1 in the sputtering room 202 one by one and subject them to sputtering one by one.
More specifically, the handling arm 230 holds one of the disk bases 1 by one of the two chucking mechanisms. Then, the sputtering arm 230 rotates around the center shaft 230a by 180°, so that the disk base 1 is inserted into the sputtering room 202. Then, the sputtering process is carried out for about 3 minutes, for example. During sputtering, the holder 20 is driven to forward move a distance corresponding to one disk base by the transport conveyer 205, and the handling arm 220 takes out the disk base 1 from the holder 20 and places it at the sputtering waiting position P. The sputtering arm 230 holds the disk base 1 at the sputtering waiting position P by the other chucking mechanism.
After the sputtering process with respect to the disk base 1 held by one of the chucking mechanisms ends, the sputtering arm 230 is rotated around the center shaft 230a by 180°. Thereby, the disk base 1 held by the other chucking mechanism is inserted into the sputtering room 202, and the disk base 1 having the magnetic thin films grown on both sides thereof is passed to the handling arm 220. At the same time, the holder 20 is driven to backward move a distance corresponding to one disk base. Thus, the handling arm 220 places the disk base 1 at the original position. Then, the handling arm 220 is moved upward and the holder 20 is driven to move a distance corresponding to two disk bases by the transport conveyer 205. Then, the handling arm 220 takes out the next disk base 1 and places it at the sputtering waiting position P. Then, the disk base 1 at the sputtering waiting position P is passed to the sputtering arm 230.
The above-mentioned procedure is repeatedly carried out, and the sputtering process is successively carried out for the 20 disk bases 1 held by the holder 20.
As shown in FIGS. 1 and 6, a reflecting mirror 250 is provided in the transport room 201 of the sputtering chamber 200. The reflecting mirror 250 reflects a thermal radiation ray (which is illustrated by a dotted line) emitted from the disk base 1 held by the handling arm 220 or the sputtering arm 230 toward a view port 260 (FIG. 1), which has a glass plate and which is provided in a front surface of the sputtering room 202. The thermal radiation ray passes through the view port 220, and is then received by a thermal radiation ray thermometer 270 (FIG. 1), which is manufactured by, for example, CHINO SEISAKUSHO, Japan. The thermometer 270 detects the received thermal radiation ray, and outputs a corresponding electrical signal. A converter 280 converts the received electrical signal into corresponding video information, which is sent to a display device 290. The display device 290 is mounted on, for example, a control panel for use in remote control, which is placed in a control room different from a room where the system is placed.
It is desirable to detect a thermal radiation ray having a wavelength in a far infrared range when the disk bases 1 are formed of aluminum. It is preferable to determine the wavelength of the thermal radiation ray to be detected on the basis of a material forming the disk bases 1.
As shown in FIG. 2, the unloading chamber 300 has a transport conveyer 330, an eject opening 325 with a lid 320, and a cryopump 340 First, the cryopump 340 is activated, so that an inner room of the unloading chamber 300 is set to a substantially vacuum state. Next, the opening and shutting door 80 is opened. Then, the holder 20 is passed from the transport conveyer 205 to the transport conveyer 330 of the unloading chamber 300, and then the opening and shutting door 80 is closed. Then, a leaf valve (not shown for the sake of simplicity) like the leaf valve 150 (FIG. 1) is opened, so that the inner room of the unloading chamber 300 is returned to the atmosphere pressure. In this state, the lid 320 is opened so that the eject opening 325 is exposed. The holder 20 having the disk bases 1 having the grown thin films is passed to an output transport conveyer 60. After that, the lid 320 is closed and the inner room of the unloading chamber 300 is exhausted by the cryopump 340, so that the unloading chamber 300 is ready for the transport of the next holder 20.
According to the above-mentioned embodiments, it is possible to detect the temperature of the disk base 1 obtained immediately before it is inserted into the sputtering room 202 by means of the reflecting mirror 250, the thermometer 270, the temperature converter 280 and the display device 290. For example, information about the temperature is manually input to the controller 400. The controller 400 uses this temperature information in addition to the information obtained from the thermocouples 112 and 212 (FIG. 3), and controls the lamp heaters 110a, 110b, 210a and 210b so that the temperature of each disk base 1 obtained immediately before it is inserted into the sputtering room 202 becomes equal to a predetermined constant temperature.
A description will now be given of a second preferred embodiment of the present invention with reference to FIG. 7, in which those parts which are the same as those shown in the preceding figures are given the same reference numerals. The thin film forming system shown in FIG. 7 has a lamp heater 500 and a temperature controller 600. The lamp heater 500 heats the disk base 1 at the sputtering waiting position where the disk base 1 is rotated by one of the chucking mechanisms of the sputtering arm 230.
As shown in FIGS. 6 and 7, the lamp heater 500 is provided on both the sides of the disk base 1 at the sputtering waiting position P The lamp heater 500 is controlled by the temperature controller 600. The temperature information (electrical signal) output by the thermometer 270 is directly sent to the temperature controller 600 as a feedback signal. The temperature controller 600 adjusts a driving current to be supplied to the lamp heater 500 in accordance with the temperature information in such a way that the temperature obtained immediately before the disk base 1 is inserted into the sputtering room 202 is approximately equal to the predetermined temperature. It will be noted that the controller 400 directly controls the lamp heaters 110a, 110b, 210a and 210b. Alternatively, it is possible to control these lamp heaters by using the feedback signal from the thermometer 270.
According to the second embodiment of the present invention, the temperature of the disk base 1 obtained immediately before it is inserted into the sputtering room 202 is measured and fed back to the temperature controller 600 in real time. Thus, it is possible to always set the temperature of each disk base 1 which is about to be inserted into the sputtering room 202 to the predetermined temperature at high reliability. Thus, it is possible to produce the disk bases 1 having almost the same characteristics in commercial quantity.
FIG. 8 is a graph showing the temperatures of various samples of disk bases obtained when they are individually placed in the sputtering waiting position P. A broken line curve is related to a prior art having no temperature control and a solid line curve is obtained by the present invention having the aforementioned temperature control. According to the present invention, the temperatures of the samples are substantially uniform, compared to those obtained by the prior art.
The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention. | A thin film forming method includes the steps of preheating a plurality of base plates placed at a first position, sequentially picking up the base plates one by one and positioning a picked-up base plate at a second position, heating the picked-up base plate at the second position so that a temperature of the picked-up base plate becomes approximately equal to a predetermined temperature, moving the picked-up base plate from the second position to a third position, and growing a thin film on a surface of the picked-up base plate at the third position. | 2 |
This application is a continuation-in-part of application Ser. No. 866,458 filed Jan. 3, 1978, now U.S. Pat. No. 4,215,814.
BACKGROUND OF THE INVENTION
This invention relates to a heat energy conservation device for use with heating equipment, wherein the heater is ON and doing its heating and then again is OFF because it has done its work. In either case heat loss occurs and it is the minimizing of this heat loss that the invention is directed to. The term heater used herein includes furnaces, hot water boilers, not water tanks and heating apparatus of various types using gas, oil and other fuels requiring connection to a chimney.
More particularly the present invention relates to a choke in the form of an inverted U, V, or L shape combined with the flue of the heater to form a fluid trap. This trap employed between the flue of the heater and the chimney, chokes off hot air from its heat interchange surfaces while in an OFF or non-heating mode to eliminate this large loss of heat energy. Heaters such as these by their very nature and design are both heat absorbers as well as heat exchangers. Their nature does not change when they are changed from an OFF mode where their burner is OFF to an ON mode where their burner is ON or vice versa. They still act as heat exchangers and thereby promptly lose the heat they had gained to return to the ambient temperature of their environment.
One problem with the present flue connections used, which in many cases are mandatory by local laws, is the inclusion of a draft deflector or diverter usually placed at the top of the heater and then piped to the chimney. By virtue of its location, at the top of the heater, it is constantly taking away heated air lost from heating areas of the heater and also warm room air and delivering it to the chimney and out of the living space, a complete loss and waste of this heat energy. Also by being located at the top of the heater it is drawing room air from a stratum of, warmer than average room air.
The present invention uses the principle of a deflector or so called draft diverter, to take advantage of its usefulness and compliance to the safety laws but places it lower and to the side of the heater where it takes air from a lower stratum and a lower temperature, to reduce the thermal loss when evacuating room air. Of greater importance is the fact that the present invention further chokes off the lost hot air of the appliance to slow down the reverse heat transfer of its heating surfaces when the burner is OFF but yet does not impede the flow of hot combustion gasses through to the chimney when the burner is ON. The choking off of hot gasses also gradually lowers the chimney temperature and this then in turn lowers its motivation to draw as strongly as when hotter.
A principal object of this invention is to provide an attachment which allows free flow of hot gasses from a heater to a chimney when the heater is ON and which chokes off the flow of hot gasses when the heater is OFF to retain residual heat energy.
Another main object is to utilize all of the interior space in the overall displacement of the device to accomplish the maximum choke effect by stratification of the hot gasses.
A further object is to obtain that just mentioned object with the minimum amount of material in its make up.
Another object is to provide a choke without moving parts, which works by the natural law of gravity and changes its mode of ON or OFF by its confrontation with temperature and pressure of the flue gasses.
A still further object is to use the invention as a heat exchange device as well as a trap when in the ON mode to retain additional energy for the user.
Another object is to provide a choke chamber having a pan part formed from a folded single sheet of material.
One other object is to provide a choke chamber having a top plate with depending side walls and a base plate with upstanding side walls, each complimenting the other to form the closed choke chamber.
SUMMARY
This invention provides a means to prevent heat loss from a heating apparatus which has residual or stored heat energy. The natural law of gravity either lets the flow of hot gasses pass through the device freely or chokes off the flow of gasses by the stratification of these gasses in the trap chambers provided. Further saving of heat energy can be accomplished by using the device as a heat interchanger to return normally lost heat energy back into the heating system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention as well as further objects and features thereof will be understood more clearly and fully from the following detailed description of the preferred embodiment, when read in conjunction with the accompanying drawings, in which;
FIG. 1 is a central vertical longitudinal section of a hot gas trap fitted onto a heater,
FIG. 2 is a horizontal section taken along line 2--2 of FIG. 1, looking downwardly,
FIG. 3 is an end elevational view of FIG. 1 from the left,
FIG. 4 is a perspective view of a choke chamber constructed of a single retangle of sheet metal with gusseted folds at its corners,
FIG. 5 is a vertical, central, longitudinal section similiar to FIG. 1 of a modified construction,
FIG. 6 is a horizontal section, looking downwardly and taken along line 6--6 in FIG. 5,
FIG. 7 is an end elevational view, taken from the left of FIG. 5,
FIG. 8 is a vertical longitudinal section of a modification illustrated diagramatically,
FIG. 9 is a vertical, central, longitudinal section similiar to FIG. 1 of another construction,
FIG. 10 is a vertical cross section on line 10--10 of FIG. 9,
FIG. 11 is a horizontal section, looking downwardly along line 11--11 of FIG. 9 and
FIGS. 12 and 13 are perspective of a top part and a bottom part of FIG. 9.
GENERAL OPERATION
The cause and effect of the operation of the traps in the ON or free flow mode or in the OFF or choke mode as applied to heaters is elaborated in great detail in the previous application, Ser. No. 866,458, U.S. Pat. No. 4,215,814, so here only a brief review of operation will be explained.
When the trap is confronted with a pressurized fast flow of combustion gasses at a high temperature and large volume, it freely passes these gasses. The resistance to up and down flow in the trap is partially overcome by a siphoning effect.
Contrarily though when the trap confronts a slow flow of gasses of relatively low temperature and at small volume, it will allow, and aid in, the stratification of these gasses in stratta or layers, higher temperature gasses at the top and lower temperature gasses at the bottom to stifle and choke off the flow of gasses through the trap.
DETAILED DESCRIPTION
In FIGS. 1, 2 and 3 is shown a hot gas trap 12 positioned on a heater 10 having a flue 9. The trap 12 may be comprised of an inverted pan shaped housing 13 having a top wall 14 with depending end walls 15 and side walls 16 with the openside closed by a base plate 17 having a sealed periferal fastening 18. These parts 13, 14, 15, 16 and 17, combined from the horizontal leg or an elongated chamber 22 for the trap 12.
An opening 20 in the base plate 17 is provided with an upstanding heater connection 21. This duct 21 extends a distance somewhat greater than half of the height of the side and end walls 15 and 16, into the interior of the elongated chamber 22, inside of the top wall 14, end walls 15, side walls 16 and the base plate 17.
At its other end the base plate 17 is provided with another opening 23 which is provided with a depending tubular shroud portion 24 which has a chimney connection duct 25 fitted to it just below the base plate 17. The mounting of the shroud 24 into the opening 23 may be made in a conventional flaring fastening means 26 with sufficient looseness to allow for 360° rotation.
Fastened to the flared end of shroud 24 in any suitable manner is a chimney leg duct 27 which projects upwardly into the chamber 22 a distance somewhat greater than one half of the height of the side and end walls 16 and 15 similar to the heater connection duct 21, just explained.
Although the chimney leg duct 27 is shown fastened to the shroud portion 24 it could just as easily be stationarly fixed to the top side of the base plate 17 instead.
The chamber 22 is divided into two connected trap compartments, a first stage compartment 30 and a second stage compartment 31 by a baffle plate 32 having flanges 32'. Baffle plate 32 depends downwardly from the top wall 14 a distance somewhat greater than one half of the height of the side and end walls 16,15 and may be fastened in any suitable manner to walls 14,15,16. The space below the lower end of baffle 30 and base plate 17 provides a through passage 33 between the compartments 30,31 and provides a fluid connection between the heater connection duct 21 and the chimney leg duct 27.
As can be seen by the flow arrows 34,35,36 and 37 there is a clear communication passage for gasses from the heater connection duct 21, compartment 30, passage 33 compartment 31, chimney leg duct 27 into shroud 24 and to the chimney via the chimney connection 25.
The upstanding heater connection duct 21 and chimney leg duct 27 with the downstanding baffle plate 32 all contained in the chamber 22 now function as a pair of gas traps, a first stage in the compartment 30, and a second stage in the compartment 31.
The construction described thus far constitutes a hot gas trap 12 similar to that shown in any application Ser. No. 866,458, U.S. Pat. No. 4,215,814 with the exception that the heater connection duct 21 and the chimney leg duct 27 are inverted and inserted inside of the choke chamber 22, instead of extending away and outside of the chamber 22. This conserves and makes use of space that was not used and in addition provides a gas trap with two gas trap stages 30,31 rather than only one, thus making a more effective choke. The head h is now added to the head H giving a greater choking effect. If the same size scale is used relative to FIG. 10 of the previous application, that being one, the form shown in this application FIG. 1 would equal one and three quarters.
The chimney connection 25 being placed at a right angle to the shroud duct 24 effectively shields the heater by diverting the down drafts from the chimney into the environ space 37 as indicated by the arrow 40.
Pan shaped housing 13 and base plate 17 which comprise the trap 12 is covered with a thickness of insulation 41 to help retain heat in the trap to its highest temperature for best stratification when in the choke mode.
The housing 13 might be fabricated by deep drawing and stretching the metal into form as well as other fabricating means, however the housing 13 shown in FIGS. 1-4 is fabricated from a single rectangular sheet of metal by using a brake machine, Four folded pleats 19 at the corners are then turned inwardly along the inside or outside of one of the side or end walls 15,16 to form the housing 13.
It is also contemplated that this housing 13 might also be cast en-bloc of suitable material that in this form might combine the qualities required for structural strength and thermal insulation.
A further modified construction is shown in FIGS. 5-7 wherein three stages of choking are included in the same size and space required by the invention shown in FIGS. 1-4.
Similar terms are used here with the numbered parts having the prefix 1 added thereto.
The hot gas trap 112 comprises a similar pan shaped housing 113 having a top wall 114 with depending end and side walls 115,116. The openside is closed by a base plate 117 in a sealed relationship 118 to the periferal edges of the housing 113 as at 118.
Trap 112 is shown as fitting onto the top of a heater 110. Its base plate 117 is provided at one end with an opening 120 and another opening 123 at the other end. Opening 120 fits around the heater flue 109 to conduct flue gasses into a heater connection duct 121 formed in the interior of chamber 122 of housing 113 by a first baffle plate 150.
Plate 150 has side flanges 151 and a bottom flange 152. It may be fastened to the side walls 116 by flanges 151 or if preferred to base plate 117 by its bottom flange 152.
A similar center baffle plate 154 has side flanges 155 and a bottom flange 156 and another similar last baffle plate 160 forms the chimney leg duct 127. It Has side flanges 161 and a bottom flange 162. Both plate 154 and 160 may be mounted as explained above for plate 150. The upper ends of these baffles 150, 154 and 160 spaced from the wall 114 form the flow passages 153, 157 and 163.
Between the upstanding baffles 150 and 154 is another 170, depending from the top wall 114 and fastened thereto by its flange 172 and side flanges 171 to the side walls 116. The lowermost end of baffle plate 170 extends short of base plate 117 to provide a passage space 173.
Similarly baffle plate 174 extends down from top wall 114 between the plates 154, 160, short enough to form a passage space 177.
In the opening 123 of the base plate 117 a shroud portion or duct 124 is flared as at 126 which allows for 360° rotation. A chimney connection 125 is provided on the shroud 124 for venting to a chimney.
It can now be seen that the intermeshing of the upper baffles 171, 174 with the lower baffles 150, 154 and 160 provide three trap compartments 180, 181 and 182 for the stratification of the passive gasses when the heater is in the OFF mode. Hot gasses from the flue 109 of the heater 110 would flow into and through these trap compartments 180, 181, 182 in the following sequence, heater connection duct 121, compartment 180, passage 153, arrow 190, passage 173, arrow 191, compartment 181, passage 157, arrow 192, passage 177, arrow 193, compartment 182, passage 163, arrow 194, into chimney leg 127 and then to the chimney connection 125 of the shroud duct 124 via arrow 195.
The double headed arrow 196 in the shroud 124 and chimney connection 125 represent air flow from the chimney into environ space 137 or air flow from environ space 137 to the chimney.
From the foregoing the trap compartments 180 and 181 provide two heads of pressure h+h while the trap compartment 182 and the chimney leg duct 127 provides a larger head of pressure H. We now have a choking heat of h+h+H which as previously explained relative to my application Ser. No. 866,458, U.S. Pat. No. 4,215,814, this would be an improved choking of two and three eights to one. This materially aids the hot passive air/gas to stratify and trap the passage of air/gas.
This form of the invention has been provided with an outer housing 200 encompassing but spaced therefrom to provide a thin air space 205. This air space 205 can be used to insulate the housing 113 by trapped air in the space 205 or it can be used to act as a heat exchanger unit when used with a furnace having a hot air circulating system.
An air inlet 206 is provided as well as an air outlet 207 in the housing 200 and the outlet 207 is connected to the cold air return of the system. When the furnace is ON, environ air is drawn into the housing through inlet 206, the air is heated by the walls 114, 115, and 116 and drawn into the circulating system to have the heat reclaimed, adding to the efficiency of the furnace.
Suitable means for holding the trap 113 to a heater 110 may be used such as ears 210 on the base plate 117 and sheet metal screws 211.
FIG. 8 shows another form of the invention wherein similiar parts are numbered with the prefix 3. Here the chimney connection 325 passes through the top wall 314 of the housing 313 and projects downwardly into the chimney leg duct 327 by the dividing wall 360' to shroud 324 at the base plate 317. Otherwise it is about identical to the form of the invention shown in FIGS. 5, 6 and 7. It should also be noted that here in FIG. 8 is shown a construction wherein all of the walls 314, 315, 316, the baffles 350, 332, 360 might be made integral and monolithic, all of the walls molded into one.
Another form of construction for trap 13 is illustrated in the FIGS. 9-13 wherein all similar parts are numbered having the prefix 4.
As clearly shown in FIG. 12 the base plate 417 of the housing 413', 413" of the trap 412 in this instance has two upstanding side walls 415, 415, the two openings 420 and 423 and periferal fastenings 418 on all of its edges. In FIG. 13 the top plate 414 has two downstanding side walls 416, 416. The top wall 414 and the side walls 416 can have the baffle plates 450, 460 and 470 fastened to them in any suitable manner. A fastening lug may extend from the base plate 413" to hold the trap onto the heater 410 by a screw 411, with a gasket 475 to make the mounting gas tight.
A swiveling shroud 424 is shown in FIG. 9 with its flared mounting 426 in the opening 423 for connection to a chimney by its chimney connection 425.
Housing part 413" is fabricated as shown in FIG. 12 with the shroud 424 added and the periferal edges formed into the fastenings 418. Housing part 413' is fabricated with the baffles 450, 460, 470 and then assembeled to the part 413" by inserting its periferal edges into the fastenings 418 on part 413". The upper ends of the side walls 415, 415 are sprung away from each other to allow housing part 413' to seat into the fastenings 418 and when part 413' is down all the way into the fastenings 418, the side walls 415,415 are moved toward each other to complete the engagement of the top plate edges 414, 414 into the fastenings 418 to retain and seal all of the periferal edges of the part 413' to complete the assembly and form the chamber 422.
This just described construction has a minimum of wasted material, it being the material stamped out of the opening 420 and 423. It also has the maximum of enclosed gas volume within its outside dimensions.
From the forgoing descriptions and illustrations it should be apparent that a very compact flue gas trap is shown that will more effectively choke off lost heat from a heater because of its multiple choke effect in a space saving arrangement.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible within the scope of the invention claimed. | An energy conserving device for preventing loss of heat energy from a heater to a chimney by means of a fluid gas heat trap to choke off either chimney draft and/or heated convectional air currents lost to the chimney when the heater is OFF but allowing combustion gasses to vent freely to the chimney when such gasses are generated. The deivce also acts as a diverter for either up or down drafts from the chimney to direct them away from the heater. In another form when the device is used with a forced air type furnace, the device in addition provides heat interchange between room air and the hot gasses in the trap. This then heated air is drawn into the circulating system of the furnace adding to its temperature while lowering the temperature of the vented combustion gasses, to lessen the heat loss up the chimney. | 5 |
This application claims the benefit of U.S. Provisional Application No. 60/575,957, filed Jun. 1, 2004.
FIELD OF INVENTION
The present invention is directed towards a method of treating aquifers, ground water, waste streams, and soils contaminated with organic pollutants. More specifically, the invention relates to the area of treatment of contaminated waters or soils by an oxidizing agent and a catalyst. It was found that the use of certain forms of silica as the catalyst enhanced the activity of the oxidizing agent. Moreover, the use of silica with a metal catalyst and oxidizing agent exhibited even a greater remediation effect. Additionally the condition of the treated material is such that subsequent normal bacterial processes can occur unimpeded by residual chemicals from the treatment materials.
BACKGROUND OF INVENTION
The following description of the background of the invention is provided to aid in understanding the invention, but is not admitted to be, or to describe, prior art to the invention. All publications are incorporated by reference in their entirety.
Chemical oxidation of unwanted chemicals has been used for many decades. The use of oxidants such as chlorine bleach, hydrogen peroxide, potassium permanganate, potassium persulfate, sodium perborate and a host of other similar oxidizing chemicals dates from the 1800's. The science of chemical oxidation is similar to that of bleaching clothes. The two major differences between bleaching clothes and oxidizing undesirable chemicals are:
1) In bleaching clothes the oxidizing agent is applied at low concentration in hot water while in ground water treatment of chemicals, the concentrations of the oxidizing agent used are higher at the point of treatment and are in cold water. 2) In bleaching clothes the oxidants are selected so as not to impart color to the solution or to the clothes whereas in ground water remediation, discoloration of the soil is of lesser concern but the treated water color should not be affected.
For decades technology has been sought to improve the effectiveness of oxidizing agents. An example of one improvement is the use of metal catalysts to increase the oxidizing effects of oxidizing agents. For example, the use of iron as a catalyst is described in a 1955 text book (Edwin S. Gould, “Inorganic Reactions and Structure”, Henry Holt and Company, 1955 pp. 76-78). The oxidative relationship between hydrogen peroxide permanganate and persulfate is also described.
Fieser and Fieser (Louis F. Fieser and Mary Fieser, “Reagents for Organic Synthesis”, John Wiley and Sons, 1967 pp. 472-476, 952-954, 1102) describe the use of iron salts with peroxide to make the so-called Fenton's Reagent citing the original paper by Fenton in 1894. It was found that chelates of iron work as well or better than iron alone and that other metal salts may also work. The Fiesers also discussed the metal catalysis of persulfate. However it was found that the oxidation did not proceed to completion. That is, specific reaction sequences are described leading from one series of chemicals to another. Specifically it was not shown that the reactions, for example of hydrocarbons and carbohydrates, led to complete oxidation of the materials to carbon dioxide and water. The present day aim of oxidizing technology for removal of pollutants can be described as follows:
1) To proceed as far as possible toward complete removal of the substrate species;
2) To proceed as rapidly as possible; and
3) To use as little reagent as possible.
The concept of using minimal reagent while providing efficient oxidation is especially important in treating chemicals in ground water or soils by oxidation where it is not desirable to leave the oxidant in the water or in the ground and to minimize the concentration of non native chemical species.
The use of chelated metals, specifically iron with a hydrogen peroxide liberating salt such as sodium perborate or sodium percarbonate is disclosed in U.S. Pat. No. 4,119,557 as part of an overall detergent formulation. In this patent the chelating agent using iron was shown to be superior to other metals such as copper and cobalt.
Recent applications related to ground water have been published. Many of these pregrant publications do not discuss the common chemistry surrounding bleaching. For example, U.S. PreGrant Publication 20020002983 A1 discusses the addition of iron chelates to ground water under buffered conditions. The main claim is to the use of the reagent solution comprising iron chelate and a pH buffering agent. U.S. Pat. No. 6,315,494 B1 dealing with soil remediation by permanganate oxidation discloses the use of metal catalysts.
With regard to bleaching compositions, further technology has ensued in making various forms of particles to be added to detergent formulations either with or without catalysts. For example, U.S. Pat. No. 5,902,783 describes a bleaching agent which is based on a silicate core and contains a peroxy material such as sodium percarbonate and a metal chelating agent in an organic compound. These materials are described for washing use and are undesirable in groundwater remediation as the materials would add more organic materials to the water being treated. Furthermore, these particles are described as being useful for incorporation in a box of detergent powder. U.S. Pat. No. 6,547,490 B1 describes similar types of particles except these are silicone coated rather than the silicone acting as a core. Both the silicone products and the silicates are not silica. The silicones are considered to be ground water contaminats.
It is important to distinguish the purpose of chemical oxidation from the process where the release of oxygen is to cause biological remediation of ground water contaminants or contaminants in soils. In the case of biological remediation the purpose is to feed the bacteria oxygen slowly over time and allow them to metabolize the contaminant. Oxidizing agents such as described previously for the direct chemical oxidation of the contaminants would be injurious to the microbes and defeat the purpose of the subsequent aerobic metabolism. When using chemical oxidation the possibility exists that the oxidation is unlikely to be complete so that the aquifer or soil must be left in a condition where the residual microbes on the edges of the treatment zone can effectively metabolize the residual oxidized materials and reoccupy their ecological niche in the treatment zone.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 The reduction of toluene in hours by oxidation with KMnO 4 solutions
FIG. 2 The reduction of toluene in hours by oxidation with sodium persulfate solutions
FIG. 3 The reduction of toluene in hours by oxidation with sodium percarbonate solutions
FIG. 4 The reduction of PCE in hours by oxidation with sodium percarbonate solutions.
FIG. 5 The reduction of p-xylene in hours by oxidation with sodium percarbonate formulation.
FIG. 6 The reduction of MTBE in hours by oxidation with sodium percarbonate formulation.
FIG. 7 Comparison of sodium silicate versus silica in the reduction of PCE.
SUMMARY OF INVENTION
The present invention is directed towards a method of treating aquifer, ground water, or soil contaminated with organic pollutants. In one aspect methods are described where the aquifer or other waters are contacted with an oxidizing agent and a catalyst where the catalyst is silica. Additional methods are described where soil is contacted with an oxidizing agent and a catalyst where the catalyst is silica.
In one aspect the size of the size is 70 to 400 mesh. A further aspect is a silica mesh size of 100 to 230. In a further aspect the silica has a surface area available for nitrogen adsorption of 150 to 300 meters square per gram.
There are provided methods where the aquifer, ground water, or soil is contacted with the catalyst and an oxidizing agent sequentially. In a further aspect the catalyst and oxidizing agent are premixed in a slurry and then the slurry contacted with the aquifer, ground water, or soil. In an additional aspect the ratio of silica to oxidizing agent is 1:1.
Also are provided methods where the oxidizing agent is independently selected from the group consisting of salts of percarbonate, persulfate, and permanganate. In an additional aspect the oxidizing agent is independently selected from the group consisting of solutions of percarbonate, persulfate, and permanganate.
In one aspect a second catalyst is added to the remediation oxidation process. In a further aspect the second catalyst is independently selected from the group consisting of iron, palladium, platinum, ruthenium, and zinc. In another aspect the catalyst, second catalyst, and oxidizing agent are premixed in a slurry and then the slurry is contacted with the aquifer, ground water, or soil.
Also are provided formulations for the described methods where the concentration of oxidizing agent is 40 to 80% and the concentration of a catalyst is 15 to 60%. In a further aspect the concentration of the oxidizing agent is 40-80%, the concentration of the catalyst is 15-60% and the concentration of a second catalyst is 0 to 5%. In an additional aspect the concentration of oxidizing agent is 40-80%, the concentration of first catalyst is 15-55% and the concentration of a second catalyst is 4 to 5%. In another aspect the concentration of percarbonate is 80%, the concentration of silica is 15% and the concentration of iron is 5%
In one aspect the silica catalyst provides a means for maintaining open pores in the soil. In an additional aspect maintaining open pores allows the oxidant to penetrate the soil system further allowing the oxidizing agent to more thoroughly contact the contaminant in the presence of silica.
DEFINITIONS
In accordance with the present invention and as used herein, the following terms are defined with the following meanings, unless explicitly stated otherwise.
The term “enhancing” refers to increasing or improving a specific property.
The term “administered simultaneously” refers to the administration of one composition at or near the same time in which another composition is administered. Preferably administration is within 30 minutes of one another.
The term “therapeutically effective amount” refers to an amount that has any beneficial effect in treating aquifer, soil, wastestream, river(s) and river water, well(s) and well water, and any body of water.
The term “biodegradable” has its normal and usual meaning and may also refer to compounds that are readily utilized or degraded by naturally occurring microorganisms.
The term “silica” refers to amphorous silica, solid silica gel, or to high silica zeolites containing at least 95% silica.
The term “xylene” refers to p-xylene.
The term “soil” refers to the loose material that covers the land surfaces of Earth and supports the growth of plants. In general, soil is an unconsolidated, or loose, combination of inorganic and organic materials. The inorganic components of soil are principally the products of rocks and minerals that have been gradually broken down by weather, chemical action, and other natural processes. The organic materials are composed of debris from plants and from the decomposition of the many tiny life forms that inhabit the soil. Soils comprise a mixture of inorganic and organic components: minerals, air, water, and plant and animal material. Mineral and organic particles generally compose roughly 50 to 70 percent of a soil's volume. The other 30 to 50 percent consists of pores—open areas of various shapes and sizes. Networks of pores hold water within the soil and also provide a means of water transport. Oxygen and other gases move through pore spaces in soil. Pores also provide room for the growth of plant roots.
The term “aquifer” refers to an underground bed or layer of earth, soil, gravel or porous stone that yields water and through which water usually flows.
The term ‘organic pollutant’ refers to but is not limited to chemicals on the Environmental Protection Agency lists of such chemicals as updated from time to time and chemicals for which remedial action is required when they are released into the environment.
The term ‘silica surface area’ refers to the silica surface area for nitrogen gas as measured by the Brunauer, Emmett and Teller (BET) technique, in which nitrogen is used to measure the total surface area of the particles.
The following well known chemicals are referred to in the specification and the claims. Other abbreviations used and names are provided.
DCE: dichloroethylene
Fe: iron (ferrous or ferric)
KMnO 4 : potassium permanganate
PCE: tetrachloroethylene; perchloroethylene
MTBE: methyl tert-butyl ether
TCA: trichloroethane
BTEX: benzene, toluene, ethyl benzene and xylene
DETAILED DESCRIPTION OF INVENTION
Unexpectedly it was found that silica could be used to catalyze oxidation reactions to a surprisingly large extent. The effectiveness of sodium percarbonate, potassium persulfate and potassium permanganate were all improved utilizing silica as a catalyst, either with or without the use of iron catalyst. The silica gel can be added as a dry powder in a mixture with the oxidizing agent with or without a metal catalyst and the entire mixture injected into the treatment zone.
Silica gel in varying mesh sizes ranging from 70 to 400 were used in a weight ratio of about 1:1 with the oxidizing agent. The magnitude of the catalysis was extremely surprising considering that it is not clear that these reactions are surface mediated.
Since the purpose of metal catalysis is to generate free hydroxyl radicals when one uses peroxide under acid conditions and perhydroxyl radicals when one uses peroxide under basic conditions, it might be expected that increased surface area would capture and reduce the effectiveness of these short lived radicals. Unexpectedly it was found that silica increased the rate of the reactions due to catalysis. Silica gel may also increase the pH (more basic) in the vicinity of the particles, and it is generally held that acid conditions favor free hydroxyl radicals. Again it was found that the expected effect of silica on pH did not affect the rate of chemical oxidation.
The results in FIGS. 1-3 show three different oxidizing agents used for the same concentration of toluene. Toluene was selected as a typical aromatic hydrocarbon (usually termed BTEX for benzene, toluene, ethyl benzene and xylene). The toluene concentration used was the saturation concentration of toluene in water. This typically would be the maximum amount found in water. For example in ground water or aquifers, if free toluene was present, the free toluene would dissolve into the water to maintain a saturated concentration of toluene as the original water concentration of toluene decreased with the oxidation of toluene. Thus the toluene in both the water and surrounding area would be oxidized to effectively remove the contaminant from the site. The Figures ( FIGS. 1-3 ) show the results over the first 3-4 hours of treatment for each of three oxidants.
The results in FIG. 4 show four different sodium percarbonate oxidant formulations used for the oxidation of PCE.
The results in FIGS. 5 and 6 show the use of percarbonate with silica and an iron catalyst for the oxidation of xylene and MTBE, respectively.
Not surprisingly there are varying degrees of oxidation between the oxidants. Unexpectedly it was found that including silica with the oxidants and the catalyst gave sufficiently improved oxidation of the pollutants over the use of the oxidant and a metal catalyst. The silica effect was seen above that of the catalyst alone. Furthermore, in every case, the use of silica alone catalyzed the reaction and in the case of permanganate and persulfate the resultant catalysis was equivalent to the use of iron as the only catalyst. In remediation cases where it was undesirable to leave high levels of iron or other metal in the aquifer, silica's use would permit pollution reduction without further harm to the environment. In all cases it was found that the use of silica would shorten the time or amount of material needed for a given reduction.
The efficacy of silica with a variety of oxidants on a wider range of chemicals has been demonstrated. The list of materials oxidized is presented in the following table (Table 1) along with the half life for each of the oxidation reactions. The half lives and the reaction rate constant are based on the experimental system used. The reaction typically behaves in a first order manner in the laboratory. Even if the reaction behaves slightly different in selected field conditions, the experimental developed reaction rate constant allowed the inventors a way of evaluating the efficacy on various chemicals. The experimental developed information reactions were shown in a field site oxidation of contaminants study given in Example I (Tables 2-4).
The experimental data presented in Table 1 were obtained from experiments as described in the Examples A-H that follow. In general, a solution of the contaminant was made up in 100 ml of water. The solution contained either (1) dissolved contaminant or (2) saturated with contaminant. Two equivalent solutions were made and the oxidant formula was added to one of the two solutions. The second solution was untreated with the oxidant formula and served as the control for that particular contaminant and oxidant formula. Contaminant concentrations in both solutions (treated and untreated) were measured over time by gas chromatography. The reduction of the contaminant in the test solution was compared versus the concentration of the contaminant in the control. The methodology used accounted for the potential loss of contaminant by off-gassing from the control solution.
In one aspect the following range of formulations were used:
Sodium percarbonate (or other oxidant)
40-80%
Silica (or equivalent SiO 2 amount of silicate)
15-60%
Ferrous salt (equivalent Fe +2 as sulfate)
0-5%
In an additional aspect the higher rates of oxidation as measured occurred with the following formulations:
Sodium percarbonate (or other oxidant)
40-80%
Silica (or equivalent SiO 2 amount of silicate)
15-55%
Ferrous salt (equivalent Fe +2 as sulfate)
4-5%
In a further aspect another formulation as given below was used:
Sodium percarbonate (or other oxidant)
47.6%
Silica (or equivalent SiO 2 amount of silicate)
47.6%
Ferrous salt (equivalent Fe +2 as sulfate)
4.8%
In another aspect a further formulation as given below was used:
Sodium percarbonate (or other oxidant)
80.0%
Silica (or equivalent SiO 2 amount of silicate)
15%
Ferrous salt (equivalent Fe +2 as sulfate)
5%
The formulation will change depending on the geochemistry of the site's geochemistry. For example, a site high in organic materials other than the contaminant may require a higher oxidant to silica ratio.
It was found that making a premixed slurry of sodium silicate and water gave equivalent results in the half life of the contaminant along with an equivalent rate constant (Table 1). It was found that using a slurry that was partially sodium silicate gave a stable slurry. As the pH dropped the sodium silicate present in the slurry turned to silica. The results in FIG. 7 show that using of sodium silicate/percarbonate/iron versus using silica/percarbonate/iron formula gave equivalent results.
TABLE 1
Chemical Tested With Oxidant Formulation
Chemical
half life
rate constant
Treatment
Oxidized
hours
/hour
percarbonate + silica + iron
toluene
0.8
0.866
percarbonate + iron
toluene
1
0.693
percarbonate + silica
toluene
2.8
0.248
percarbonate
toluene
7
0.099
persulfate + silica + iron
toluene
1
0.693
persulfate + iron
toluene
1.25
0.555
persulfate + silica
toluene
1.5
0.462
persulfate
toluene
infinite
0
permanganate + silica + iron
toluene
3
0.231
permanganate + iron
toluene
7
0.099
permanganate + silica
toluene
7.5
0.092
permanganate
toluene
7
0.099
percarbonate + silica + iron
PCE
1
0.693
percarbonate + iron
PCE
4
0.173
percarbonate + silica
PCE
9
0.077
percarbonate
PCE
30
0.023
percarbonate + silica + iron
PCE
1.5
0.462
percarbonate + Na silicate + iron
PCE
1.9
0.365
persulfate + silica + iron
PCE
1.2
0.578
persulfate + iron
PCE
2.3
0.301
persulfate + silica
PCE
4.6
0.151
persulfate
PCE
30
0.023
permanganate + silica + iron
PCE
1.75
0.396
permanganate + iron
PCE
5
0.139
permanganate + silica
PCE
0.6
1.155
permanganate
PCE
0.9
0.770
percarbonate + silica + iron
TCA
6
0.116
percarbonate + silica + iron
xylene
2.6
0.267
percarbonate + silica + iron
phenanthrene
2.7
0.257
percarbonate + silica + iron
naphthalene
13
0.053
percarbonate + silica + iron
MTBE
10.5
0.066
percarbonate + silica + iron
ethylbenzene
7.5
0.092
percarbonate + silica + iron
DCE
1.2
0.578
percarbonate + silica + iron
benzene
16
0.043
percarbonate + silica + iron
octane
5.5
0.126
persulfate
octane
10.5
0.066
permanganate
octane
13
0.053
EXAMPLES
Example A
Oxidation of Toluene by Potassium Permanganate
Solutions containing equal concentration of toluene (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) potassium permanganate (3 g); (b) potassium permanganate (3 g) and silica (3 g), (c) potassium permanganate (3 g), ferrous sulfate (0.3 g).and (d) potassium permanganate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of toluene in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the toluene concentration in the test solution was compared versus the concentration of the toluene in the control. The methodology used accounted for the potential loss of toluene by off-gassing from the control toluene solution.
Example B
Oxidation of Toluene by Sodium Persulfate
Solutions containing equal concentration of toluene (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) sodium persulfate (3 g); (b) sodium persulfate (3 g) and silica (3 g), (c) sodium persulfate (3 g), ferrous sulfate (0.3 g).and (d) sodium persulfate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of toluene in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the toluene concentration in the test solution was compared versus the concentration of the toluene in the control. The methodology used accounted for the potential loss of toluene by off-gassing from the control toluene solution.
Example C
Oxidation of Toluene by Sodium Percarbonate
Solutions containing equal concentration of toluene (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) sodium percarbonate (3 g); (b) sodium percarbonate (3 g) and silica (3 g), (c) sodium percarbonate (3 g), ferrous sulfate (0.3 g).and (d) sodium percarbonate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of toluene in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the toluene concentration in the test solution was compared versus the concentration of the toluene in the control. The methodology used accounted for the potential loss of toluene by off-gassing from the control toluene solution.
Example D
Oxidation of PCE by Potassium Permanganate
Solutions containing equal concentration of PCE (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) potassium permanganate (3 g); (b) potassium permanganate (3 g) and silica (3 g), (c) potassium permanganate (3 g), ferrous sulfate (0.3 g).and (d) potassium permanganate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of PCE in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the PCE concentration in the test solution was compared versus the concentration of the PCE in the control. The methodology used accounted for the potential loss of the contaminant by off-gassing from the control solution.
Example E
Oxidation of PCE by Sodium Persulfate
Solutions containing equal concentration of PCE (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) sodium persulfate (3 g); (b) sodium persulfate (3 g) and silica (3 g), (c) sodium persulfate (3 g), ferrous sulfate (0.3 g).and (d) sodium persulfate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of PCE in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the PCE in the test solution was compared versus the concentration of the PCE in the control. The methodology used accounted for the potential loss of the contaminant by off-gassing from the control solution.
Example F
Oxidation of PCE by Sodium Percarbonate
Solutions containing equal concentration of PCE (500 ppm) were made up in 100 ml of water. One of the four oxidant formula was added to one of the solutions. The four oxidant formulations used were: (a) sodium percarbonate (3 g); (b) sodium percarbonate (3 g) and silica (3 g), (c) sodium percarbonate (3 g), ferrous sulfate (0.3 g).and (d) sodium percarbonate (3 g), silica (3 g) and ferrous sulfate (0.3 g). The second solution was untreated and served as the control for the solutions treated by oxidant formulation, a, b, c, or d. Concentration of PCE in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction of the PCE in the test solution was compared versus the concentration of the PCE in the control. The methodology used accounted for the potential loss of the contaminant by off-gassing from the control solution.
Example G
Oxidation of Xylene by Sodium Percarbonate
Solutions containing equal concentration of xylene (180 ppm) were made up in 100 ml of water. Oxidant formula consisting of sodium percarbonate (3 g), silica (3 g) and ferrous sulfate (0.3 g) was added to one of the solutions. A second solution was untreated and served as the control for the solution treated by oxidant formulation. Concentration of xylene in both solutions (treated solution and untreated control) was measured over time by gas chromatography. The reduction in concentration of the xylene in the test solution was compared versus the concentration of the xylene in the control. The methodology used accounted for the potential loss of the contaminant by off-gassing from the control solution.
Example H
Oxidation of MTBE by Sodium Percarbonate
Solutions containing equal concentration of MTBE (5500 ppm) were made up in 100 ml of water. Oxidant formula consisting of sodium percarbonate (3 g), silica (3 g) and ferrous sulfate (0.3 g) was added to one of the solutions. A second solution was untreated and served as the control for the solution treated by oxidant formulation. Concentration of MTBE in both solutions (treated solution and treated control) were measured over time by gas chromatography. The reduction of the MTBE concentration in the test solution was compared versus the concentration of the MTBE in the control. The methodology used accounted for the potential loss of the contaminant by off-gassing from the control solution.
Example I
Field Site Oxidation of Contaminants
At a field site that was 30×20 feet at the surface and 15 to 17 feet deep (approximately 10,000 ft 3 ), a formulation containing 475 pounds of sodium percarbonate (88%), 50 pounds of silica (9.3%) and 15 pounds of ferrous sulfate (2.7%) was injected after the materials were mixed in water. The contaminants at the site were benzene, ethylbenzene, toluene, xylene (meta/para and ortho), naphthalene, 1,2,4-trimethyl benzene and 1,3,5-trimethylbenzene. The formulation was injected in three separate wells and the results of the oxidation measured at each well over a period of one week after the injection.
The results for each well are given respectively in Tables 2-4.
TABLE 2 Values at Well 1 (μg/L) Chemical Peak Value Final Value Half life (hrs) Benzene 184 21 46 Ethylbenzene 381 7 25 Toluene 174 14 40 Xylene (m,p) 440 90 63 Xylene (o) 83 43 152 Naphthalene 91 43 132 1,2,4-Trimethylbenzene 236 5 28 1,3,5-Trimethylbenzene 128 115 374
Peak value is highest concentration measured during test
Final value is the concentration at the end of one week.
TABLE 3 Values at Well 2 (μg/L) Chemical Peak Value Final Value Half life (hrs) Benzene 174 6 52 Ethylbenzene 543 37 52 Toluene 57 2 52 Xylene (m,p) 420 35 51 Xylene (o) 85 4 49 Naphthalene 130 12 54 1,2,4-Trimethylbenzene 258 22 49 1,3,5-Trimethylbenzene 159 16 57
Peak value is highest concentration measured during test
Final value is the concentration at the end of one week.
TABLE 4 Values at Well 3 (μg/L) Chemical Peak Value Final Value Half life (hrs) Benzene 67 <1 24 Ethylbenzene 166 7 31 Toluene 28 1 32 Xylene (m,p) 195 10 33 Xylene (o) 31 4 49 Naphthalene 25 5 60 1,2,4-Trimethylbenzene 128 3 29 1,3,5-Trimethylbenzene 57 14 69
Peak value is highest concentration measured during test
Final value is the concentration at the end of one week.
The wells were monitored at the beginning and then four times during the test. The peak values of contaminants in the wells did not occur at the beginning of the test due to the movement of water and contaminants in field sites. The tables report the peak value that occurred during the period of the test and the value that was measured at the end of one week.
The half lives that are given in the tables are calculated from the time between readings using readings that showed a decrease between periods and assuming first order kinetics. This calculation is imprecise in field situation as a result of influx of material at the various wells. The half life values, however, are expected to be longer than in systems without packed soil due to the restricted movement of the oxidant and contaminant allowing fewer collisions per unit time in packed soil. In packed soils the solids obscure approximately 75% of the space in a three dimensional volume. Thus, molecules only have 25% of the space to move within compared to a solution and are more likely to hit soil than they are other molecules that are involved in the h reaction. Reactions take place when molecules collide so the rate of any reaction is related to the number of collisions that will occur per unit time. In the absence of other effects, therefore, one would expect that the rate would be some 3-4 times slower in soil because there are 3-4 times fewer collisions between the molecules involved in the reaction. The values are relatively consistent and provide validation for similar reactions occurring throughout the treatment zone. | The treatment of contaminated waters or soils by an oxidizing agent and a catalyst is described. The addition of silica as a catalyst to an oxidizing agent with or without an additional metal catalyst showed a greater remediation effect. Subsequent normal bacterial processes are unimpeded since the treatment process does not leave residual chemicals. | 2 |
BACKGROUND OF THE INVENTION
This invention relates generally to fasteners for securing composite decking to a steel supporting structure, and more particularly to a self-drilling fastener for use as a self-drilling stud in lightweight or normal weight composite deck structures which are used as floors or roofs in modern buildings.
During construction of a composite deck, sheets of metal decking, which is often corrugated but can also be flat, are usually fastened to steel structural members. Located along and projecting upwardly from the steel members are metal studs. A concrete slab formed over the steel decking encapsulates the metal studs, so that the studs restrict relative shear movement between the concrete slab and the steel member.
Two general types of studs, weld studs and self-drilling studs, are typically used in a composite deck. Standard weld studs are welded directly to the decking and steel structural members. These studs are ductile so they are suited to restrict the relative shear movement between the concrete slab and the steel. Installation of a weld stud requires that it burn through the decking in order to attach itself to the steel support member. During this process the decking will burn away around the steel weld stud and will typically not attach itself to the support member. This would require a separate attachment operation to attach the deck to the support member.
Further a round ceramic insulator is used at the end of the weld stud during the installation process. it is used in order to concentrate the heat and assist in welding of the stud to the support member. Once the weld stud is attached, the round ceramic insulator needs to be removed from the base of the weld stud, in order for the concrete to encapsulate the stud. At this point the typical way of removing these ceramic insulators is to strike them with a hammer to break them away from the base of the installed weld studs. Since these ceramic insulators are brittle, when broken away from the weld studs they shatter and scatter ceramic pieces over the deck surface. These ceramic pieces need to be removed from the deck surface prior to concrete pour, both for safety reasons and to avoid integration into the concrete mixture and contamination of the concrete integrity. Use of self-drill shear studs does not require the above extra operations.
In the process of stud welding through the decking the protective deck coating is damaged from the intense heat produced, rendering it susceptible to corrosion. Typical recommended practice is to apply a protective coating to the bare or damaged decking material to reduce corrosion effects. Use of self-drill shear studs does not require the above extra operation.
Due to the nature of the weld joint between the stud and the steel, the diameter of the weld stud establishes a minimum material thickness that is required for the structural member. The smallest weld studs that are presently commercially used establish a lower limit on the material thickness of the structural member that can be used with those weld studs. The smallest diameter weld stud currently available is 1/2" diameter which requires a minimum of 0.200" thick steel. If steel thicknessies less than 0.200" usually encountered in typical bar joist construction, the weld stud is not recommended. Self-drilling shear studs present an alternative in these applications.
Self-drilling studs are thus an attractive alternative to weld studs for use in composite decks. Self-drilling studs do not limit the minimum material thickness of the structural member. In addition, self-drilling studs secure the decking to the steel, thereby eliminating the separate attachment needed with the use of weld studs. Self-drilling studs also avoid other problems with weld studs, such as the removal of the ceramic insulator from the stud after its installation, and the cleanup of ceramic pieces which are occasioned by the removal. The decking is not damaged, and indeed, the need to repair the metal decking and attach it to the stud or the metal support is eliminated. Use of a self-drilling stud does not create a damaged area of the decking which must be repaired and instead, when properly installed provides a means for attaching the deck to the steel member. However, in order for the self-drilling studs to be capable of drilling the steel, the self-drilling studs must be heat treated to a relatively high degree of hardness. This standard processing results in the reduced ductility, and ductility is necessary in the self-drilling stud to transfer the shearing movement in the composite deck system. Some self-drilling studs have attempted to compensate for this basic deficiency by isolating the stud from the concrete with a spacer. The spacer attempts to convert the shearing action of the concrete slab into a bending moment which the hardened stud is more adept at resisting. However, it does not change the non-ductile nature of the self-drilling studs themselves.
SUMMARY OF THE INVENTION
The general aim of the present invention is to provide a new and improved one-piece self-drilling stud for use in a composite deck system where the use of standard weld studs is inappropriate because the material cross-section of the steel member is less than accepted practice.
A more detailed objective is to achieve the foregoing by heat treating the stud to a dual-hardness level so that a portion of the stud is capable of drilling the steel while the remaining portion of the stud is sufficiently ductile to transmit the shearing forces in a composite deck system to the main structural members.
An even more specific objective is to achieve the foregoing by heat treating a drill point, cutting threads and lead threads in the self-drilling stud to a relatively high degree of hardness while maintaining the remainder of the stud in a relatively ductile condition.
Another general aim of the invention is to provide for enhanced interlocking between the self-drilling stud and the concrete slab in a composite deck system.
It is a feature of the invention that a self-drilling stud is provided with an integral flange which automatically establishes the height of the portion of the stud that is encapsulated in the concrete slab for proper concrete cover, which secures the decking to the steel, and which is shaped to transmit shearing loads.
A further feature is the provision of a self-drilling stud with a second integral flange which is located near the driving head of the stud and which interacts with the concrete to limit deflection of the steel. This feature can be enhanced by use of a self-drilling shear stud composite nut in conjunction with the shear stud when used with thin steel structural members.
These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a typical composite deck structure utilizing new and improved self-drilling studs incorporating the unique features of the present invention.
FIG. 2 is a enlarged fragmentary cross-sectional view taken substantially along the line 2--2 of FIG. 1.
FIG. 3 is an enlarged side view of one of the studs shown in FIGS. 1 and 2.
FIG. 4 is an enlarged bottom view of the stud as seen along the line 4--4 of FIG. 3.
FIG. 5 is a cross-sectional view taken axially through the stud of FIG. 3, the cross hatch patten representing an area of the stud that is heat treated to a relatively high degree of hardness.
FIG. 6 is an enlarged view of the drilling and drilling end of the stud shown in FIG. 5.
FIG. 7 is a partial view, similar to FIG. 2, showing a modified version of shear stud in an installation suitable for light weight steel structural members.
While the invention is susceptible of various modifications and alternative constructions, a certain illustrated embodiment hereof has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For purposes of illustration, the present invention is shown in the drawings as embodied in a self-drilling fastener 10 (FIG. 1) which is especially useful as a self-drilling stud in composite deck structures 11 which are used as floors or roofs in modern buildings. A floor or roof deck is subject to shear forces which tend to cause a horizontal, or shearing, movement of the deck relative to its support structure. The self-drilling stud 10 of the present invention restricts and transfers this shearing movement when used in a composite deck system.
A composite deck 11 is typically fabricated at a building site. During construction of the building, metal secondary structural members 12, such as joist or beams, but not restricted thereto, are joined to the building structural support beams (not shown). The metal structural members will sometimes be referred to herein as metal joists, with such term being used in its broadest sense as a general characterization of metal secondary structural members. When steel joists are used they are typically comprised of vertically spaced upper and lower elongated horizontal members 13A and 13B, and further comprise supporting web members 14 joined to and extending between the horizontal members 13A and 13B. In light weight composite deck systems, the joist members are formed with material cords having a relatively thin cross-section (e.g., less than 0.200"). Metal decking 15 is typically laid over and spans adjacent joists so that corrugations, if present, run at a right angle to the joists, although the composite deck may be fabricated without corrugated decking. Located in and projecting upwardly from the upper members 13A of the joists and through the corrugated decking are the self-drilling studs 10. A concrete slab 16 is poured over the corrugated decking, encapsulating the upper portion of the studs.
Each self-drilling stud 10 (FIG. 3) has an elongated shank 17 with an integral threaded portion 18 having helical threads, and an unthreaded portion 19. Projecting from the lower end of the threaded portion is a fluted drill tip 20. Located at the end of the stud opposite the drill tip is a driving head 21. The driving head is formed to engage a driving tool which is capable of rotating the stud, such as but not limited to the hex-shaped driving head shown in FIG. 3 and a hex-shaped socket driver, or any of the many other well known rotational driving means. The driving tool is then used to drive the drill tip and threaded portion of the stud through the valleys of the corrugated decking 15 (FIG. 2) and the upper members 13A of the steel joist 12.
The drill tip 20 is defined by two metal cutting edges 22 and two flutes 23. The two flutes extend upwardly from the end of the stud and into the first few helical threads in the threaded portion 18. Two beveled faces 24 are milled on the end of the tip at an angle projecting upwardly and outwardly from the center of the stud. The two beveled surfaces are diametrically spaced around the end of the stud (FIG. 4). The two flutes 23 are also diametrically spaced and begin approximately 90 degrees rotated from the beveled surfaces. The cutting edges 22 of the drill tip are defined by the sharp edges created at the intersection of the flutes and the beveled surfaces and are located at the six o'clock and twelve o'clock positions when the stud is viewed as in FIG. 4. The cutting threads 25 (FIG. 3) of the self-drilling stud 10 are defined by the first few threads which are opened by the flutes that extend into the threaded portion 18 adjacent the drill point.
In accordance with the present invention, the self-drilling stud 10 (FIG. 2) is selectively heat treated to a dual-hardness level so that the lower portion of the stud has a relatively high degree of hardness to enable it to drill and tap the decking 15 and steel member (i.e. joists) 12, while the remaining portion of the stud is heat treated to a lesser degree of hardness so that it remains relatively ductile and capable of resisting and transmitting the shearing forces of the concrete slab 16, generally directed left or right, relative to the support. In addition, the self-drilling stud is uniquely constructed so that it correctly positions itself in and enhances interlocking with the concrete slab, in addition to establishing correct concrete slab cover.
More specifically, an integral annular flange 26 is located between the threaded and unthreaded portions 18 and 19 of the stud 10. During construction of the composite deck 11, the lower portions of the self-drilling studs 10 (FIG. 2) are driven through the valleys of the decking 15 and through the upper horizontal members 13A of the steel joists 12. When each stud is tightened, the bottom of the flange 26 engages the decking 15, thereby clamping the decking to the underlying horizontal joist member. The flange 26 provides positive localized clamping which is found to be quite effective in these applications. In addition, the flange 26 adds stability to the tightened stud and positions the height of the driving head 21 relative to the horizontal joist member, thereby defining the portion of the stud that will be encapsulated in the concrete slab 16, for correct concrete cover requirements above the stud.
The shape of the flange 26 is of particular significance. A lower surface 30 is substantially flat and joins the threaded shank portion 18 at a reasonably sharp right angle. When the stud is drilled into place as shown in FIG. 2, the lower surface 30 will securely clamp the top side of the decking to the underlying joist.
In contrast to the flat and sharply angled lower side, the upper side of the flange 26 is smoothly radiused as at 32 to flare slowly from the angular flange to the upstanding shank. It is found that the curved or radiused junction is important to prevent cracking of the stud when subjected to bending loads. The curved shape may also tend to distribute the shear forces, particularly when the concrete deck itself has a significant component loading the flange against the corrugated decking and joist.
A second integral annular flange 27 (FIG. 3) is located directly below the driving head 21, between the driving head and the unthreaded portion 19 of the stud 10. The flange 27 is larger in diameter than flange 26.
When a shearing force acts on the upper portion of the stud 10 which is encapsulated in the concrete slab 16 (FIG. 2), the unthreaded portion 19 of the stud tends to bend, in a cantilever fashion, about the center of the lower flange 26, thereby tending to pivot the driving head 21 and the upper flange 27. As the upper flange 27 and the driving head try to pivot in the concrete, the concrete surrounding the upper flange 27 and the driving head responds with a restoring force couple. This force couple is applied to the lower side of the flange 27 opposite the shearing force and to the upper side of the flange 27 and driving head on the side of the shearing force, thereby tending to reduce the deflection of the stud in response to the shearing force. In this manner, the relatively large diameter flange 27 enhances the structural interlocking between the stud and the concrete slab. This same force couple also has the effect of creating an upwardly directed force on the stud at the underside of the top flange 27, which tends to act through the threaded section to reduce the lower cord deflection of the joist into which the stud is threaded.
FIG. 7 illustrates a modified version of a shear stud according to the invention particularly suitable for light weight steel structural members. In the embodiments described thus far, the shear stud relies on threaded engagement with a steel structural member for retention to the decking system. However, when the secondary steel support is rather thin, an auxiliary means of retention can be useful. FIG. 7 shows a shear stud 10 constructed in the same manner as the shear studs of the prior embodiments, but associated with a retention member 40 intended to increase the resistance of the stud to pullout from the steel support. The retention member 40 is a special designed composite nut adapted for use with the shear stud 10. The shear stud 10 is installed in the decking system as in the case of prior embodiments. However, either before or after pouring of the concrete deck, a workman will access the array of shear studs from below the deck and apply a nut 40 to the threaded portion of the shank which projects through the decking and secondary structural support. The nut 40 can be applied with a conventional power nut driver, in a relatively simple operation where the workman simply proceeds along the line of studs, from stud to stud, applying special nuts to each. The presence of the nut 40 in connection with the thin structural member will significantly increase the pullout force from the stud and provide significant assistance in transmitting shear loads from the deck to the structural member.
In carrying out the invention, the self-drilling stud 10 is heat treated to a dual-hardness level with a Drill-Flex® heat treating process developed by Elco Industries, Inc., Rockford, Ill. Specifically, the lower portion of the self-drilling stud, as shown in FIGS. 5 and 6 by cross hatch, comprising the drill tip 20 and a minority of turns 28 of the threaded portion 18 including the cutting threads 25 and a few lead threads adjacent the cutting threads is heat treated to a relatively high hardness so that it is capable of effectively drilling and tapping the decking 15 and the upper horizontal joist member 13A. The remaining portion of the self-drilling stud, i.e., the driving head 21, the unthreaded portion 19, the annular flanges 26 and 27 and the remaining threaded portion 18 which engages the joist member and is adjacent the annular flange 26, is heat treated to a lesser degree of hardness so that it remains relatively ductile and capable of resisting and transmitting the shearing forces of the floor or roof secondary members to the main structural supports without failure. By way of example, the lower portion of the stud is hardened to 50 minimum Rockwell C while the remaining portion of the stud is hardened to 50%-70% of drill tip. An example not required with the above explanation.
From the foregoing, it will be apparent that the present invention brings to the art a new and improved unsheathed self-drilling stud 10 for use in lightweight or normal weight composite decks 11 where the use of standard weld studs is precluded. In addition, the ability of the self-drilling stud 10 to resist and transfer shear forces in a composite deck is enhanced over prior self-drilling studs by virtue of the dual-hardness levels embodied in the stud and the provisions of the integral flange 27 which enhances interlocking between the stud and the concrete slab 16 and secondary and primary structural members. Also installation advantages over weld studs. | A self-drilling stud particularly suited for use in normal weight or lightweight composite deck system where the use of standard weld studs is inappropriate because of the relatively thin material cross-section of the steel support member. The stud is heat treated to a dual-hardness level so that a portion of the stud is capable of drilling the support member and the decking. The remaining portion of the stud remains relatively ductile so that it can withstand and transfer shear loads imposed by shifting of the concrete slab which overlies the decking to the main support members. The stud is a single piece fastener which includes specially formed annular flanges which enhance interlocking between the stud, the concrete slab and support members. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to and the benefit of Korean Patent Application No. 10-2015-0170986 filed on Dec. 2, 2015, the entire contents of which is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an automatic transmission for a vehicle.
Description of Related Art
Recent increases in oil prices are triggering hard competition in enhancing fuel consumption of a vehicle.
In this sense, research on an engine has been undertaken to achieve weight reduction and to enhance fuel consumption by so-called downsizing and research on an automatic transmission has been performed to simultaneously provide better drivability and fuel consumption by achieving more shift stages.
In order to achieve more shift stages for an automatic transmission, the number of parts is typically increased, which may deteriorate installability, production cost, weight and/or power flow efficiency.
Therefore, in order to maximally enhance fuel consumption of an automatic transmission having more shift stages, it is important for better efficiency to be derived by a smaller number of parts.
In this respect, an eight-speed automatic transmission has been recently introduced, and a planetary gear train for an automatic transmission enabling more shift stages is under investigation.
Considering that gear ratio spans of recently developed eight-speed automatic transmissions are typically between 6.5 and 7.5, fuel consumption enhancement is not very large.
In the case of a gear ratio span of an eight-speed automatic transmission having a level above 9.0, it is difficult to maintain step ratios between adjacent shift stages to be linear, by which driving efficiency of an engine and drivability of a vehicle deteriorated.
Thus, research studies are underway for developing a high efficiency automatic transmission having nine or more speeds.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY
Various aspects of the present invention are directed to providing a planetary gear train of an automatic transmission for a vehicle having advantages of, by minimal complexity, realizing at least forward ninth speeds and at least one reverse speed, increasing a gear ratio span so as to improve power delivery performance and fuel consumption, and achieving linearity of shift stage step ratios.
An exemplary planetary gear set according to an embodiment includes
an input shaft for receiving an engine torque, an output shaft for outputting a shifted torque, a first planetary gear set having first, second, and third rotational elements, a second planetary gear set having fourth, fifth, and sixth rotational elements, a third planetary gear set having seventh, eighth, and ninth rotational elements, a fourth planetary gear set having tenth, eleventh, and twelfth rotational elements, and six control elements for selectively interconnecting the rotational elements.
The input shaft may be continuously connected with the third rotational element,
The output shaft may be continuously connected with the eleventh rotational element,
The first rotational element may be continuously connected with the fourth rotational element,
The second rotational element may be continuously connected with the eighth rotational element and twelfth rotational element,
The fifth rotational element may be continuously connected with the tenth rotational element. The sixth rotational element may be continuously connected with the seventh rotational element.
The first rotational element may be selectively connectable with the eleventh rotational element. The second rotational element may be selectively connectable with the third rotational element. The sixth rotational element may be selectively connectable with the ninth rotational element. The fifth rotational element may be selectively connectable with the transmission housing. The sixth rotational element may be selectively connectable with the transmission housing. The ninth rotational element may be selectively connectable with the transmission housing.
The first, second, and third rotational elements of the first planetary gear set may respectively be a sun gear, a planet carrier, and a ring gear of the first planetary gear set. The fourth, fifth, and sixth rotational elements of the second planetary gear set may respectively be a sun gear, a planet carrier, and a ring gear of the second planetary gear set. The seventh, eighth, and ninth rotational elements of the third planetary gear set may respectively be a sun gear, a planet carrier, and a ring gear of the third planetary gear set. The tenth, eleventh, and twelfth rotational elements of the fourth planetary gear set may respectively be a sun gear, a planet carrier, and a ring gear of the fourth planetary gear set.
A planetary gear train according to an exemplary embodiment of the present invention may realize at least forward ninth speeds and at least one reverse speed formed by operating the four planetary gear sets as simple planetary gear sets by controlling six control elements.
In addition, a planetary gear train according to an exemplary embodiment of the present invention may realize a gear ratio span of more than 8.7, thereby maximizing efficiency of driving an engine.
In addition, the linearity of step ratios of shift stages is secured while multi-staging the shift stage with high efficiency, securing linearity of step ratios of shift stages, thereby making it possible to improve drivability such as acceleration before and after a shift, an engine speed rhythmic sense, and the like.
Further, effects that can be obtained or expected from exemplary embodiments of the present invention are directly or suggestively described in the following detailed description. That is, various effects expected from exemplary embodiments of the present invention will be described in the following detailed description.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a planetary gear train according to an exemplary embodiment of the present invention.
FIG. 2 is an operational chart for respective control elements at respective shift stages in a planetary gear train according to an exemplary embodiment of the present invention.
It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
The drawings and description are to be regarded as illustrative in nature and not restrictive, and like reference numerals designate like elements throughout the specification.
In the following description, dividing names of components into first, second, and the like is to divide the names because the names of the components are the same as each other and an order thereof is not particularly limited.
FIG. 1 is a schematic diagram of a planetary gear train according to an exemplary embodiment of the present invention.
Referring to FIG, a planetary gear train according to an exemplary embodiment of the present invention includes first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 arranged on a same axis, an input shaft IS, an output shaft OS, seven connecting members TM 1 to TM 7 for interconnecting rotational elements of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , six control elements C 1 to C 3 and B 1 to B 3 , and a transmission housing H.
Torque input from the input shaft IS is shifted by cooperative operation of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , and then output through the output shaft OS.
The simple planetary gear sets are arranged in the order of first, first, third, second, fourth planetary gear sets (PG 1 , PG 3 , PG 2 , PG 4 ), from an engine side.
The input shaft IS is an input member and the torque from a crankshaft of an engine, after being torque-converted through a torque converter, is input into the input shaft IS.
The output shaft OS is an output member, and being arranged on a same axis with the input shaft IS, delivers a shifted torque to a drive shaft through a differential apparatus.
The first planetary gear set PG 1 is a single pinion planetary gear set, and includes a first sun gear S 1 , a first planet carrier PC 1 that supports a first pinion P 1 externally engaged with the first sun gear S 1 , and a first ring gear R 1 internally engaged with the first pinion P 1 . The first sun gear S 1 acts as a first rotational element N 1 , the first planet carrier PC 1 acts as a second rotational element N 2 , and the first ring gear R 1 acts as a third rotational element N 3 .
The second planetary gear set PG 2 is a single pinion planetary gear set, and includes a second sun gear S 2 , a second planet carrier PC 2 that supports a second pinion P 2 externally engaged with the second sun gear S 2 , and a second ring gear R 2 internally engaged with the second pinion P 2 . The second sun gear S 2 acts as a fourth rotational element N 4 , the second planet carrier PC 2 acts as a fifth rotational element N 5 , and the second ring gear R 2 acts as a sixth rotational element N 6 .
The third planetary gear set PG 3 is a single pinion planetary gear set, and includes a third sun gear S 3 , a third planet carrier PC 3 that supports a third pinion P 3 externally engaged with the third sun gear S 3 , and a third ring gear R 3 internally engaged with the third pinion P 3 . The third sun gear S 3 acts as a seventh rotational element N 7 , the third planet carrier PC 3 acts as an eighth rotational element N 8 , and the third ring gear R 3 acts as a ninth rotational element N 9 .
The fourth planetary gear set PG 4 is a single pinion planetary gear set, and includes a fourth sun gear S 4 , a fourth planet carrier PC 4 that supports a fourth pinion P 4 externally engaged with the fourth sun gear S 4 , and a fourth ring gear R 4 internally engaged with the fourth pinion P 4 . The fourth sun gear S 4 acts as a tenth rotational element N 10 , the fourth planet carrier PC 4 acts as an eleventh rotational element N 11 , and the fourth ring gear R 4 acts as a twelfth rotational element N 12 .
In the arrangement of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , the first rotational element N 1 is directly connected with the seventh rotational element N 7 , the second rotational element N 2 is directly connected with the fifth rotational element N 5 and the twelfth rotational element N 12 , and the fourth rotational element N 4 is directly connected with the ninth rotational element N 9 , the eighth rotational element N 8 is directly connected with tenth rotational element N 10 , by seven connecting members TM 1 to TM 7 .
The seven connecting members TM 1 to TM 7 are arranged as follows.
The first connecting member TM 1 is connected with the first rotational element N 1 (first sun gear S 1 ) and the fourth rotational element N 4 (second sun gear S 2 ).
The second connecting member TM 2 is connected with the second rotational element N 2 (first planet carrier PC 1 ) and eighth rotational element N 8 (third planet carrier PC 3 ) and the twelfth rotational element N 12 (fourth ring gear R 4 ).
The third connecting member TM 3 is connected with the third rotational element N 3 (first ring gear R 1 ), directly connected with the input shaft IS thereby continuously acting as an input element, and selectively connectable with the second connecting member TM 2 .
The fourth connecting member TM 4 is connected with the fifth rotational element N 5 (second planet carrier PC 2 ) and the tenth rotational element N 10 (fourth sun gear S 4 ), and selectively connectable with the transmission housing H thereby acting as a selective fixed element.
The fifth connecting member TM 5 is connected with the sixth rotational element N 6 (second ring gear R 2 ) and the seventh rotational element N 7 (third sun gear S 3 ), and selectively connectable with the transmission housing H, thereby acting as a selective fixed element.
The sixth connecting member TM 5 is connected with the ninth rotational element N 9 (third ring gear R 3 ), selectively connectable with the transmission housing H thereby acting as a selective fixed element, and selectively connectable with the fifth connecting member TM 5 .
The seventh connecting member TM 7 is connected with the eleventh rotational element N 11 (fourth planet carrier PC 4 ), selectively connectable with the first connecting member TM 1 , and directly connected with the output shaft OS thereby continuously acting as an output element.
The connecting members TM 1 to TM 7 may be selectively interconnected with one another by control elements of three clutches C 1 , C 2 , and C 3 .
, The connecting members TM 1 to TM 7 may be selectively connectable with the transmission housing H, by control elements of three brakes B 1 , B 2 , and B 3 .
The six control elements C 1 to C 3 and B 1 to B 3 are arranged as follows.
The first clutch C 1 is arranged between the first connecting member TM 1 and the seventh connecting member TM 7 , such that the first connecting member TM 1 and the seventh connecting member TM 7 may selectively become integral.
The second clutch C 2 is arranged between the second connecting member TM 2 and the third connecting member TM 3 , such that the second connecting member TM 2 and the third connecting member TM 3 may selectively become integral.
The third clutch C 3 is arranged between the fifth connecting member TM 5 and the sixth connecting member TM 6 , such that the fifth connecting member TM 5 and the sixth connecting member TM 6 may selectively become integral.
The first brake B 1 is arranged between the fourth connecting member TM 4 and the transmission housing H, such that the fourth connecting member TM 4 may selectively act as a fixed element.
The second brake B 2 is arranged between the fifth connecting member TM 5 and the transmission housing H, such that the fifth connecting member TM 5 may selectively act as a fixed element.
The third brake B 3 is arranged between the sixth connecting member TM 6 and the transmission housing H, such that the sixth connecting member TM 6 may selectively act as a fixed element.
The control elements of the first, second, and third clutches C 1 , C 2 , and C 3 and the first, second, and third brakes B 1 , B 2 , and B 3 may be realized as multi-plate hydraulic pressure friction devices that are frictionally engaged by hydraulic pressure.
FIG. 2 is an operational chart for respective control elements at respective shift stages in a planetary gear train according to an exemplary embodiment of the present invention.
As shown in FIG. 2 , a planetary gear train according to an exemplary embodiment of the present invention performs shifting by operating two control elements at respective shift stages.
In the forward first speed shift stage D 1 , the first and third brakes B 1 and B 3 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the fourth connecting member TM 4 and the sixth connecting member TM 6 simultaneously act as fixed elements by the operation of the first and third brakes B 1 and B 3 , thereby realizing the forward first speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward second speed shift stage D 2 , the third clutch C 3 and the first brake B 1 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the fifth connecting member TM 5 becomes integral with the sixth connecting member TM 6 by the operation of the third clutch C 3 . In addition, the fourth connecting member TM 4 acts as a fixed element by the operation of the first brake B 1 , thereby realizing the forward second speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward third speed shift stage D 3 , the first and second brakes B 1 and B 2 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , the fourth connecting member TM 4 and the fifth connecting member TM 5 simultaneously act as fixed elements by the operation of the first and second brakes B 1 and B 2 , thereby realizing the forward third speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward fourth speed shift stage D 4 , the first clutch C 1 and the first brake B 1 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the first connecting member TM 1 becomes integral with the seventh connecting member TM 7 by the operation of the first clutch C 1 . In addition, the fourth connecting member TM 4 acts as a fixed element by the operation of the first brake B 1 , thereby realizing the forward fourth speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward fifth speed shift stage D 5 , the first clutch C 1 and the second brake B 2 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the first connecting member TM 1 becomes integral with the seventh connecting member TM 7 by the operation of the first clutch C 1 . In addition, the fifth connecting member TM 5 acts as a fixed element by the operation of the second brake B 2 , thereby realizing the forward fifth speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward sixth speed shift stage D 6 , the second clutch C 2 and the second brake B 2 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the second connecting member TM 2 becomes integral with the third connecting member TM 3 by the operation of the second clutch C 2 . In addition, the fifth connecting member TM 5 acts as a fixed element by the operation of the second brake B 2 , thereby realizing the forward sixth speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward seventh speed shift stage D 7 , the first and second brakes C 1 and C 2 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the first planetary gear set PG 1 becomes integral by the operation of the second clutch C 2 . In addition, the first connecting member TM 1 becomes integral with the seventh connecting member TM 7 by the operation of the first clutch C 1 , thereby realizing the forward seventh speed and outputting an inputted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward eighth speed shift stage D 8 , the second clutch C 2 and the third brake B 3 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the second connecting member TM 2 becomes integral with the third connecting member TM 3 by the operation of the second clutch C 2 . In addition, the sixth connecting member TM 6 acts as a fixed element by the operation of the third brake B 3 , thereby realizing the forward eighth speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the forward ninth speed shift stage D 9 , the first clutch C 1 and the third brake B 3 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the first connecting member TM 1 becomes integral with the seventh connecting member TM 7 by the operation of the first clutch C 1 . In addition, the sixth connecting member TM 6 acts as a fixed element by the operation of the third brake B 3 , thereby realizing the forward ninth speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
In the reverse speed REV, the second and the third brakes B 2 and B 3 are simultaneously operated. As a result, torque of the input shaft IS is input to the third connecting member TM 3 , and the fifth connecting member TM 5 and the sixth connecting member TM 6 simultaneously act as fixed elements by the operation of the second and the third brakes B 2 and B 3 , thereby realizing the reverse speed by cooperative operation of respective connecting members and outputting a shifted torque through the output shaft OS connected with the seventh connecting member TM 7 .
As described above, a planetary gear train according to an exemplary embodiment of the present invention may realize the forward nine speeds and one reverse speed formed by operating the four planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 by controlling three clutches C 1 , C 2 , and C 3 and three brakes B 1 , B 2 , and B 3 .
In addition, a planetary gear train according to an exemplary embodiment of the present invention may realize a gear ratio span of more than 8.7, thereby maximizing efficiency of driving an engine.
In addition, the linearity of step ratios of shift stages is secured while multi-staging the shift stage with high efficiency, thereby making it possible to improve drivability such as acceleration before and after a shift, an engine speed rhythmic sense, and the like.
For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | Nine or more forward speeds and at least one reverse speed are achieved by a planetary gear train of an automatic transmission for a vehicle including an input shaft, an output shaft, four planetary gear sets respectively having three rotational elements, and six control elements for selectively interconnecting the rotational elements. | 5 |
BACKGROUND
1. Field
In communication systems, for example Long Term Evolution (LTE) of the 3rd Generation Partnership Project (3GPP), various ways of configuring a short scheduling request (SR) cycle may be able to add flexibility for a network (NW) to configure scheduling request cycles.
2. Description of the Related Art
Release 8 (Rel-8) of Long Term Evolution (LTE) of the 3rd Generation Partnership Project (3GPP) provides two scheduling request (SR) mechanisms: dedicated periodic scheduling requests resource on a physical uplink control channel (PUCCH) configured by radio resource control (RRC) and signaling and a scheduling request sent via random access. The latter is only allowed (in Rel-8) if dedicated scheduling request resources are not configured or transmissions on the dedicated scheduling request resources fail repeatedly.
Background type traffic can be considered, for example, to be user equipment (UEs) that infrequently generate/receive small amounts of data. The interarrival time of such traffic can be in the order of several seconds or several 10 s of seconds and the amount of data to be sent can be in the order of 50-150 bytes.
Background traffic user equipment, therefore, may be allocated less frequent scheduling request resources on a physical uplink control channel. Long scheduling request cycles produce latency of uplink transmissions, as user equipment have to wait for the next scheduling request resources to indicate to an evolved Node B (eNB) that the user equipment has some data to transmit. The extra latency may have less impact at the beginning of a data session and more during a data session.
Discontinuous reception (DRX) in LTE is specified such that when a user equipment receives either downlink (DL) assignment or uplink (UL) grant on a physical downlink control channel (PDCCH), the user equipment (re)starts an inactivity timer during which the user equipment monitors the physical downlink control channel for further uplink or downlink allocations. Furthermore, after the inactivity timer expires, the user equipment uses a short discontinuous reception cycle (if configured) for a given time (discontinuous reception short cycle timer) before entering a long discontinuous reception cycle again. Thus, downlink physical downlink control channel monitoring adapts to data transmission activity.
The same is not true for periodic scheduling requests. Periodic scheduling requests are simply configured by radio resource control signaling to a (semi-)static value, which can only be changed via radio resource control reconfiguration.
The extra latency for uplink can have an impact when some data is sent in the downlink direction, which should be acknowledged in the uplink direction (for example, transmission control protocol (TCP) acknowledgment (ACK)). Delay of acknowledgment can reduce the data rate in the downlink.
To summarize, currently discontinuous reception (for downlink physical downlink control channel monitoring) adapts with data activity (long and short discontinuous reception cycles and inactivity timer) but uplink scheduling requests can only be “adapted” via radio resource control signaling.
More particularly, periodic scheduling request resources can conventionally be configured via radio resource control signaling either for small latency (for example, scheduling request resource every 5 ms) or for less resource consumption (for example, scheduling request resource every 80 ms). Alternatively, a random access (RA) based approach can be used (if periodic scheduling request resources are not configured). Random access, however, can increase load and thus collisions on the random access channel (RACH).
Thus, conventionally, an uplink scheduling request cycle can only be adapted using radio resource control signaling. This approach, however, can either lead to increased latency and/or use of extra resources for, for example, background type traffic.
SUMMARY
According to certain embodiments, a method includes detecting that there is data activity associated with a user equipment. The method also includes activating a short scheduling request cycle upon the detecting the data.
A method according to certain embodiments includes scheduling a long scheduling request cycle for a user equipment. The method also includes scheduling a short scheduling request cycle upon receiving a request regarding the user equipment.
In certain embodiments, a method includes receiving a message for configuring scheduling request resources. The method also includes activating a configured scheduling request resource in response to another reception separate from the configuring message.
A method includes configuring scheduling request resources in certain embodiments. The method also includes activating a configured scheduling request resource.
An apparatus includes at least one processor and at least one memory including computer instructions in certain embodiments. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to detect that there is data activity associated with a user equipment. The at least one memory and the computer instructions are also configured to, with the at least one processor, cause the apparatus at least to activate a short scheduling request cycle upon detection of the data.
An apparatus includes, in certain embodiments, at least one processor and at least one memory including computer instructions. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to schedule a long scheduling request cycle for a user equipment. The at least one memory and the computer instructions are also configured to, with the at least one processor, cause the apparatus at least to schedule a short scheduling request cycle upon receiving a request regarding the user equipment.
In certain embodiments, an apparatus includes at least one processor and at least one memory including computer instructions. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to receive a message for configuring scheduling request resources. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to activate a configured scheduling request resource in response to another reception separate from the configuring message.
An apparatus includes at least one processor and at least one memory including computer instructions in certain embodiments. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to configure scheduling request resources. The at least one memory and the computer instructions are configured to, with the at least one processor, cause the apparatus at least to activate a configured scheduling request resource.
In certain embodiments, a non-transitory computer readable medium is encoded with instructions that, when executed in hardware, perform a process. The process includes detecting that there is data activity associated with a user equipment. The process also includes activating a short scheduling request cycle upon the detecting the data.
A non-transitory computer readable medium, in certain embodiments, is encoded with instructions that, when executed in hardware, perform a process. The process includes scheduling a long scheduling request cycle for a user equipment. The process also includes scheduling a short scheduling request cycle upon receiving a request regarding the user equipment.
In certain embodiments, a non-transitory computer readable medium is encoded with instructions that, when executed in hardware, perform a process. The process includes receiving a message for configuring scheduling request resources. The process also includes activating a configured scheduling request resource in response to another reception separate from the configuring message.
A non-transitory computer readable medium, in certain embodiments, is encoded with instructions that, when executed in hardware, perform a process. The process includes configuring scheduling request resources. The process also includes activating a configured scheduling request resource.
An apparatus, in certain embodiments, includes detection means for detecting that there is data activity associated with a user equipment. The apparatus also includes activation means for activating a short scheduling request cycle upon the detecting the data.
In certain embodiments, an apparatus includes scheduling means for scheduling a long scheduling request cycle for a user equipment. The apparatus also includes scheduling means for scheduling a short scheduling request cycle upon receiving a request regarding the user equipment.
According to certain embodiments, an apparatus includes receiving means for receiving a message for configuring scheduling request resources. The apparatus also includes activating means for activating a configured scheduling request resource in response to another reception separate from the configuring message.
An apparatus includes configuring means for configuring scheduling request resources in certain embodiments. The apparatus also includes activating means for activating a configured scheduling request resource.
BRIEF DESCRIPTION OF THE DRAWINGS
For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:
FIG. 1 illustrates a timing diagram according to certain embodiments.
FIG. 2 illustrates a method according to certain embodiments.
FIG. 3 illustrates another method according to certain embodiments.
FIG. 4 illustrates a method according to certain embodiments.
FIG. 5 illustrates another method according to certain embodiments.
FIG. 6 illustrates a system according to certain embodiments of the present invention.
DETAILED DESCRIPTION
Certain embodiments can keep several background traffic user equipment in connected mode without consuming excessive network resources, especially physical uplink control channel (PUCCH) resources.
Scheduling request (SR) resources can be configured to be available periodically, for example, from every subframe to once per 80 ms. For background traffic, an even longer scheduling request cycle may be acceptable, especially if the user equipment is in long discontinuous reception (DRX). A discontinuous reception cycle can be up to, for example, 2.5 s.
Certain embodiments use periodic scheduling request resources with a long and short scheduling request cycle. The long scheduling request cycle can be configured by radio resource control (RRC) signaling. The short scheduling request cycle can be pre-configured by radio resource control signaling. The short scheduling request cycle can then be dynamically activated and deactivated. When activated, a short scheduling request cycle can be partly configured by radio resource control signaling and partly by media access control (MAC)/physical layer signaling.
More particularly, certain embodiments specify periodic scheduling request resource with long and short scheduling request cycles. A long scheduling request cycle can be configured or reconfigured by radio resource control signaling in the same way as a conventional scheduling request and could also be called a semi-static scheduling request resource.
In contrast, a short scheduling request cycle can be pre-configured by radio resource control signaling and it can be dynamically activated and deactivated in various ways. For example, dynamic activation or deactivation can be explicit, for example, by media access control or physical downlink control channel signaling. Alternatively, the dynamic activation or deactivation can be implicit, for example, following discontinuous reception timers. This implicit approach can be particularly applicable to deactivation. A further option is that long scheduling request cycle is not configured at all. In this case, if short scheduling request cycle is not active, UE sends scheduling requests via random access procedure. Then the short scheduling request cycle can also be activated after a scheduling request is received via random access.
Thus, activating a short scheduling request cycle can occur when there is data activity. For example, when some data is sent in the downlink and some uplink feedback is expected, such as a transmission control protocol acknowledgment.
Various implementations are possible. For example, long scheduling request cycles can be configured by radio resource control signaling in the same way as Rel-8/Rel-10 scheduling request cycles. For example, the following parameters can be given: sr-ConfigIndex, PUCCH-ResourceIndex (and sr-PUCCH-ResourceIndexP 1 ), and dsr-TransMax. The parameter sr-ConfigIndex can indicate the periodicity and the subframe offset of scheduling request resources. The parameters sr-PUCCH-ResourceIndex and sr-PUCCH-ResourceIndexP 1 can be used to derive an orthogonal sequence index as well as a cyclic shift. The parameter dsr-TransMax can give the maximum number of transmissions allowed for scheduling requests before going to random access.
Short scheduling request cycles can be partly configured by radio resource control signaling and partly configured by media access control/physical layer when activating a short scheduling request cycle.
There are several alternatives for the configuration depending on how much is configured by radio resource control signaling and how much is left for media access control/physical layer configuration. In certain embodiments, at a minimum, radio resource control can be used to configure short scheduling request feature on/off (this could also be a user equipment capability feature, such that, for example, the user equipment that indicates this capability can then have the capability activated with media access control/physical downlink control channel) and then all parameters can be given by media access control/physical layer (media access control (MAC) control element (CE) or physical downlink control channel). At the other extreme, RRC would configure short scheduling request cycles completely and media access control/physical layer would simply activate/deactivate the configured short scheduling request cycle (e.g., a new “short scheduling request activation media access control CE” or a special physical downlink control channel format).
In a certain embodiment, part of the parameters would be preconfigured by radio resource control and the rest would be configured by media access control/physical layer when activating a short scheduling request cycle.
For instance, radio resource control signaling can configure scheduling request periodicity, physical uplink control channel resource indices, and dsr-TransMax. For scheduling request periodicity, a value range can be, for example, 2, 5, 10, or 20 ms/subframes. The set of physical uplink control channel resource indices may be, for example, 4 or 8 values (or pairs of values if both antenna ports P 0 and P 1 are used). The physical uplink control channel resource index can have a value range of 0 to 2047. The parameter dsr-TransMax can be provided for short scheduling request cycles. If needed, the same value as for long scheduling request can be used here or a fixed value can be used.
If media access control level activation is used, then a media access control CE can be specified. The media access control CE can indicate which physical uplink control channel resource index from preconfigured ones to use (2 or 3 bits needed if 4 or 8 values preconfigured, respectively) as well as the subframe offset (5 bits would be enough for max periodicity of 20 subframes).
Alternatively, the subframe offset can be derived from the subframe where the media access control CE was sent/received (due to hybrid automatic repeat request (HARQ) retransmissions, this may not be known exactly). Instead of preconfiguring 4 or 8 values for physical uplink control channel resource index, the physical uplink control channel resource index (11 bits) can be signaled with the media access control CE.
If physical downlink control channel activation is used, then a physical downlink control channel (or downlink control information (DCI)) format can be specified. The timing of the physical downlink control channel can be used to determining the subframe offset (in the similar way as semi-persistent scheduling (SPS) activation physical downlink control channel determines the subframe offset for semi-persistent scheduling). For semi-persistent scheduling, a different RNTI, namely “SPS C-RNTI” can be used to distinguish SPS activation physical downlink control channel from normal physical downlink control channel.
In one embodiment, a new RNTI for short scheduling request cycle activation is provided. Then, the contents of the physical downlink control channel can be freely redesigned. Alternatively, the same approach as for physical downlink control channel order can be used here: use Format 1A, set localized/distributed bit to ‘1’ and set all resource block assignment bits to ‘1’, then the rest of the bits can be set freely. The next 2 or 3 bits can be defined to indicate which ‘command’ is sent (they can be set to all ‘0’ in this case) and then 2 or 3 bits can be used to indicate one of the 4 or 8 preconfigured physical uplink control channel resource indices.
Alternatively, 11 bits can be allocated to indicate (directly) the physical uplink control channel resource index, which may have a value range of from 0 to 2047). In this case, the periodicity alone could be preconfigured by radio resource control signaling.
In one embodiment, radio resource control signaling is used for preconfiguring the scheduling request resources except for the subframe offset, and activating the short cycle happens when the user equipment receives downlink resource assignment on the physical downlink control channel. The subframe offset of the short cycle resource is derived from the subframe of the assignment. Even in this case, there could be an indication on PDCCH which tells whether the short scheduling request cycle is activated or not.
A typical use case for short scheduling request cycle could be when a user equipment receives downlink data. Then the eNB can first wait until the next discontinuous reception on duration to send physical downlink control channel and data on a physical downlink shared channel (PDSCH). Then eNB can send the short scheduling request cycle activation command (either as media access control CE together with downlink data or as a separate physical downlink control channel command) to the user equipment and after that the user equipment would use short scheduling request cycle. Thus the user equipment would be able to request uplink grant faster than with long scheduling request cycle.
Another use case of short scheduling request cycle is to allow rapid adjustment according to variations in the number of active UEs. At one moment the number of connected mode UEs may be so low that network may be able to activate short cycles for many UEs. This would be reasonable even without data transmissions because delays that UEs experience when initiating UL transmissions would be on the average shorter than with only long cycles. At a later moment the number of connected mode UEs could become larger, and the network could deactivate some of the short cycles in order to be prepared for providing them for UEs with data reception.
FIG. 1 illustrates a timing diagram according to certain embodiments. In FIG. 1 , the upper part of the figure shows downlink monitoring activity of the physical downlink control channel. The lower part of FIG. 1 shows scheduling request resources allocated to the user equipment. When the user equipment is in long discontinuous reception and only monitoring physical downlink control channel during the onDuration time, then the scheduling request cycle can be long, for example, 320 ms (although it can still be considered long while being shorter, such as 80 ms). When data activity in downlink starts, an evolved Node B (eNB) can also activate a pre-configured short scheduling request cycle in UL (for example, by a “short scheduling request media access control (MAC) control element (CE)” or by physical downlink control channel command). This can enable faster scheduling requests in uplink when there is downlink data which may require feedback (for example, TCP ACK). When downlink data ends and the discontinuous reception inactivity timer expires and the user equipment again enters long discontinuous reception, also the short scheduling request deactivates (implicitly). Alternatively, eNB can send, e.g., physical downlink control channel command to explicitly deactivate the short scheduling request cycle. The user equipment then returns to use the configured long scheduling request cycle. Instead of having either long or short scheduling request cycle active at a time, it can be beneficial to keep the long cycle active also when the short cycle is active. Thus, there is no requirement that the long scheduling request cycle be deactivated before or when the short scheduling request is activated.
Certain embodiments allow configuring long scheduling request cycles for user equipment with only background traffic, without sacrificing the uplink latency when there is more delay critical data to be sent. This may save scheduling request resources and allow more user equipment to be kept in connected mode.
FIG. 2 illustrates a method according to certain embodiments. The method of FIG. 2 can be performed by a device such as, for example, an evolved Node B (eNodeB). As shown in FIG. 2 , a method can include, at 210 , detecting that there is data activity associated with a user equipment (UE). This detection can be performed by a device that is actually sending the data to the user equipment. In an alternative embodiment, the device that detects is not the device that sends data. The detecting can be performed when the user equipment is in a long scheduling request cycle. A further detection can be performed to make a determination as to whether to continue or extend a short scheduling request cycle. The detecting can include detecting data in a downlink for which uplink feedback is expected, such as a transmission control protocol (TCP) acknowledgement (ACK) message.
The method can also include, at 220 , activating a short scheduling request (SR) cycle upon the detecting the data. This activation can be done through explicit signaling. Alternatively, this activation can be performed by sending the data to the user equipment. In the latter case, the user equipment may be preconfigured to interpret the data as an activation of a short scheduling request cycle. Sending an explicit activation message may permit the configuration of various parameters. This process is referred to as “activation,” although it may actually require a user equipment to engage in monitoring and consequently “activation” in a different sense can take place at the user equipment.
The activating the short scheduling request cycle can include, at 222 , sending radio resource control (RRC) signaling. Also or alternatively, the activating the short scheduling request cycle can include, at 224 , sending a media access control (MAC) control element (CE). As a further option or alternative, the activating the short scheduling request cycle can include, at 226 , sending signaling on a physical downlink control channel (PDCCH). Also, the activating the short scheduling request cycle can include, at 228 , sending a request including indication of desired periodicity.
FIG. 3 illustrates another method according to certain embodiments. The method of FIG. 3 can be performed by a device such as a user equipment, although other devices can be configured to perform the illustrated method. As shown in FIG. 3 , a method can include, at 310 , scheduling a long scheduling request (SR) cycle for a user equipment. The method can also include, at 320 , scheduling a short scheduling request cycle upon receiving a request regarding the user equipment. These schedulings can refer to the scheduling of monitoring by the user equipment. The actual schedule may be determined by a base station or other network element.
The method can further include, at 330 , deactivating the short scheduling request cycle upon the expiration of discontinuous reception (DRX) timer. Alternatively, the method can include, at 335 , deactivating the short scheduling request cycle upon an explicit request. Alternatively, a separate scheduling request resource deactivation timer can be specified. The timer can be started when the short cycle is activated and it can be restarted when receiving or transmitting data or when receiving activation signaling while the timer is still running. The short cycle can be deactivated when the timer expires.
FIG. 4 illustrates another method according to certain embodiments. As shown in FIG. 4 , a method can include, at 410 , receiving a message (such as a preconfiguration message) for configuring scheduling request resources (including a set of such resources). The preconfiguration message can include at least one of the following parameters: scheduling request cycle length or periodicity; (for example, a set of) physical uplink control channel resource indices (or even just one such index); or dsr-TransMax.
The method can also include, at 420 , activating a configured (for example, preconfigured) scheduling request resource. The activating can include receiving at least one of a scheduling request cycle offset; a scheduling request cycle length or periodicity; (for example, a set of) physical uplink control channel resource indices (or even just one such index); or dsr-TransMax.
The activating can include receiving radio resource control signaling, at 422 , or media access control (MAC) control element, at 424 . The activating can also or alternatively include, at 424 , receiving signaling on a physical downlink control channel. The signaling can be a downlink resource assignment and the subframe offset of the activated scheduling request resource can be derived from the subframe of the assignment. For example, the subframe offset of the scheduling request resource can be derived from the subframe of the physical downlink control channel.
Another scheduling request cycle can already be active when the preconfigured scheduling request cycle is activated. The other scheduling request cycle can be longer than the activated preconfigured scheduling request cycle.
The method can further include deactivating, at 430 , the short scheduling request cycle upon the expiration of discontinuous reception timer, at 432 , or a timer that was started when activating the scheduling request cycle, or upon an explicit request, at 434 .
FIG. 5 illustrates another method according to certain embodiments. As shown in FIG. 5 , the method can include, at 510 , preconfiguring scheduling request resources (this can also be referred to as configuring scheduling request resources). The method can also include, at 520 , activating a preconfigured scheduling request resource (that is to say, a scheduling request configured previously, which can be referred to as a configured scheduling request resource). The method can further include, at 530 , deactivating the scheduling request resource. The activating can be similar to the activating in the embodiments illustrated in FIG. 4 .
FIG. 6 illustrates a system according to certain embodiments of the present invention. As shown in FIG. 6 , the system can include a first apparatus 610 (such as a user equipment) and second apparatus 620 (such as a base station, for example, an eNB). Each of the apparatuses may be equipped with at least one processor 630 , at least one memory 640 (including computer program instructions), and transceiver/network interface card 650 (other communications equipment, such as an antenna, may also be included). The apparatuses may be configured to communicate with one another over an interface 660 , which may be a wireless interface, but may incorporate both wireless and wired interfaces in various embodiments.
The at least one processor 630 can be variously embodied by any computational or data processing device, such as a central processing unit (CPU) or application specific integrated circuit (ASIC). The at least one processor 630 can be implemented as one or a plurality of controllers.
The at least one memory 640 can be any suitable storage device, such as a non-transitory computer-readable medium. For example, a hard disk drive (HDD) or random access memory (RAM) can be used in the at least one memory 640 . The at least one memory 640 can be on a same chip as the at least one processor 630 , or may be separate from the at least one processor 630 .
The computer program instructions may be any suitable form of computer program code. For example, the computer program instructions may be a compiled or interpreted computer program.
The at least one memory 640 and computer program instructions can be configured to, with the at least one processor 630 , cause a hardware apparatus (for example, a user equipment or base station) to perform a process, such as the processes shown in FIGS. 1-5 or any other process described herein.
Thus, in certain embodiments, a non-transitory computer-readable medium can be encoded with computer instructions that, when executed in hardware perform a process, such as one of the processes described above. Alternatively, certain embodiments of the present invention may be performed entirely in hardware.
One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims. | In communication systems, for example Long Term Evolution (LTE) of the 3rd Generation Partnership Project (3GPP), using two cycles (long and short) to configure uplink (UL) scheduling request (SR) resources, and various ways of configuring a short scheduling request cycle may be able to add flexibility for a network (NW) to configure scheduling request cycles, allowing balance between latency and resource reservation. A method, according to certain embodiments, can include detecting that there is data activity associated with a user equipment and activating a short scheduling request cycle upon the detecting the data. | 7 |
This is a division of application Ser. No. 638,825, filed Jan. 8, 1991, now U.S. Pat. No. 5,121,613
BACKGROUND OF THE INVENTION
The present invention relates generally to air conditioning and heat pump systems and more particularly, but not by way of limitation, relates to refrigerant coils used therein.
The typical indoor coil utilized with heating and cooling indoor equipment is conventionally of an inverted "V" configuration defined by two multi-row, multi-circuit fin/tube refrigerant coil slabs across which air to be cooled is flowed on its way to the conditioned space served by a furnace or air handler. Indoor coils of this type (commonly referred to as "A"-coils in the air conditioning industry) are offered in various nominal tonnages, one air conditioning "ton" being equal to an air cooling capacity of 12,000 BTU/HR. Furnaces and other air handling equipment using this type of coil are normally offered to the residential or commercial customer in an appropriate range of air conditioning tonnages which are established by the size of the A-coil installed in the furnace, or other type of air handler, in conjunction with the correspondingly sized condenser side of the overall refrigeration circuitry.
A representative air conditioning tonnage range for residential furnace applications is, for example, one to five tons, while a representative light commercial tonnage range would be from five to twenty tons. Within this overall cooling capacity range, the tonnage increment between successively larger capacity A-coils is typically 1/2, 1, 21/2 or 5 tons, with the tonnage increments usually being smaller at the lower end of the capacity spectrum.
Conventional refrigerant "A" coils have been the norm in this general furnace and air handler tonnage range for many years and have been, generally speaking, well suited for their intended purpose. However, they are also subject to a variety of well-known problems, limitations and disadvantages, particularly as pertains to their manufacture and incorporation in their associated furnaces, air handlers or the like.
For example, for each A-coil within a given multi-tonnage set thereof, it has heretofore been necessary to manufacture and inventory a differently sized pair of refrigerant coil slabs. As an example, if a manufacturer produces a line of heating and air conditioning equipment having a cooling range of from 11/2 to 20 tons, there may representatively be twelve different capacity A-coils needed-e.g., A-coils of 11/2, 2, 21/2, 3, 31/2, 4, 5, 71/2, 10, 121/2, 15 and 20 ton nominal air cooling capacities. Accordingly, twelve differently sized refrigerant coil slabs must be manufactured and inventoried.
This conventional necessity increases both tooling costs and manufacturing floor space requirements, thereby also increasing the overall manufacturing costs associated with the air conditioning systems into which the A-coils are incorporated. Additionally, each of the A-coils in a necessary capacity range thereof will typically have different depths in the direction of intended air flow therethrough. For example, in up-flow furnaces, progressively larger capacity A-coils will have correspondingly increasing vertical installation height requirements. This can result in the necessity of oversizing the cabinet height of an air handler to accommodate A-coils of varying heights. Moreover, in an attempt to reduce the number of differently dimensioned refrigerant coil slabs which must be manufactured and inventoried to assemble A-coils of the necessary different refrigeration capacities, many manufacturers provide relatively large capacity increments at the upper end of their capacity range. For example, in light commercial air conditioning equipment, the highest capacity unit may be 20 tons, while the next smaller unit may be 15 tons. If the system designer determines that, for the conditioned spaced to be served by the equipment, an air conditioning capacity of 16 tons is needed, he normally must select the 20 ton unit. This undesirably results in a 25% oversizing of the air conditioning system.
In view of the foregoing, it can be seen that it would be desirable to provide a refrigerant coil structure, and manufacturing methods associated therewith, which eliminate or at least substantially reduce the above-mentioned and other problems, limitations and disadvantages heretofore associated with conventional "A-coils" used as the indoor coils of air conditioning and heat pump systems.
SUMMARY OF THE INVENTION
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a series of identically sized flat refrigerant coil modules are utilized to form a plurality of air cooling or heating refrigerant coils of different nominal air conditioning tonnages, the coils having a different number of the modules arranged in an accordion pleated orientation.
Each of the identically sized modules is defined by a single row of parallel, laterally spaced apart heat exchange tubes serially interconnected to form a single refrigerant circuit having an inlet end for receiving refrigerant from a source thereof, and an outlet end for discharging the received refrigerant. A longitudinally spaced series of heat exchange fins are transversely connected to the heat exchange tubes.
The modular, accordion pleated fin/tube refrigerant coils of the present invention are particularly well suited as replacements for the two-slab "A-coils" conventionally incorporated in combination heating and air conditioning furnaces and the like and provide a variety of manufacturing and other advantages compared to such A-coils. For example, only one size flat refrigerant coil slab needs to be manufactured and inventoried since the accordion pleated refrigerant coil assemblies of the present invention are all fashioned from varying numbers of the identically sized coil modules. Additionally, the use of these identically sized coil modules permits the varying capacity coil assemblies which they define to have identical depths in the intended air flow direction across the coils. In turn, this permits the allocated dimensions of the coil housing or air handler, in the direction of air flow therethrough, to be essentially uniform for each furnace in a manufacturing series thereof.
Compared to conventional A-coils, the accordion pleated coils of the present invention, which are preferably defined by three or more coil modules, provide a substantially increased coil face area. For a given flow rate across the coils, during furnace or air handler operation, this increased face area reduces the coil face velocity of the air to a magnitude considerably below the minimum design velocity typically associated with A-coils. Specifically, the accordion pleated module coils of the present invention are preferably sized to provide operating face velocities in the range of from approximately 100 feet per minute to approximately 200 feet per minute.
While under conventional refrigerant coil design wisdom this unusually low coil face velocity is considered undesirable, it uniquely permits the accordion pleated modular coils of the present invention to be provided with very closely spaced heat exchange fins which are of an enhanced, slotted construction, to thereby substantially increase the air-to-fin heat exchange efficiency without increasing the air pressure drop across the accordion pleated coil to a level beyond that normally associated with conventional A-coils. Specifically, the modular coils of the present invention are designed to operate at an air side pressure drop of less than about 0.10".
To further improve the overall heat exchange efficiency of the accordion pleated coils, the primary heat exchange efficiency (i.e., the heat exchange occurring between the refrigerant and the coil tubes) is also increased by providing the tubes with an enhanced construction, preferably by forming internal grooves within the tubes.
In a preferred embodiment of the accordion pleated refrigerant coils, the identically sized refrigerant coil modules used to define the coils have a nominal air conditioning tonnage capacity of 0.5 tons (6,000 BTU/HR.). This, of course, provides the ability to set the coil-to-coil tonnage increments correspondingly at 6,000 BTU/HR. This very desirably reduced capacity increment, in turn; provides the system designer with the ability to very precisely match the indoor side of the overall air conditioning circuitry to the conditioned space building load requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut-away schematic perspective view of a representative forced air furnace or air handler having installed thereon a compact, modular refrigerant coil which embodies principles of the present invention;
FIG. 2 is an enlarged scale perspective view of the modular coil removed from the furnace;
FIG. 2A is a perspectives view of the FIG. 2 modular coil in an alternate horizontal air flow orientation thereof;
FIG. 3 is a perspective view of a representative larger tonnage version of the FIG. 2 modular coil;
FIG. 3A is a perspective view of the larger tonnage FIG. 3 modular coil in an alternate, horizontal air flow orientation thereof;
FIG. 4 an enlarged scale, partially cut-away perspective view of one of the series of identically sized, single row, single circuit refrigerant coil modules used to form the representative refrigerant coils shown in FIGS. 2, 2A, 3 and 3A;
FIG. 5 is an enlarged scale cross-sectional view through the refrigerant coil module taken along line 5--5 of FIG. 4;
FIG. 5A is an enlargement of the circled area "A" in FIG. 5; and
FIG. 6 is an enlarged scale partial cross-sectional view through an adjacent pair of enhanced heat exchange fins on the refrigerant coil module.
DETAILED DESCRIPTION
Perspectively illustrated in FIG. 1 is a typical indoor up-flow combination heating and cooling system 10 having incorporated therein a uniquely configured air-cooling evaporator coil 12 which embodies principles of the present invention. System 10 includes a housing 14 having a return air section 16 with a blower 18 disposed therein, and a coil housing section 20 disposed above the return air section 16. The coil 12, and a suitable air-heating structure 22 (such as an electric resistance heating coil or a fuel-fired heat exchanger) are operatively mounted within the housing section 20 and housing section 16, respectively.
During cooling operation of the system 10, return air 24 from the conditioned space served by the system is drawn into the housing return air section 16, by the blower 18, through a return duct 26 suitably connected to a housing opening 16 a . Return air 24 entering the housing section 16 is drawn into the blower inlet 28 and forced by the blower 18 upwardly across the heating/cooling coil 12. The cooled or heated air 24 is then flowed back to the conditioned space through a suitable supply duct 30 connected to top side opening 20 a in the housing section 20.
Turning now to FIGS. 2 and 4, according to an important feature of the present invention, the coil 12 (FIG. 2) is formed from four identically sized flat refrigerant coil modules 32 (FIG. 4) arranged in an accordion-pleated configuration and supported within the housing 20 which has an open top side 36 and an open bottom side 38. As illustrated, the coil 12 has a depth D extending parallel to the flow of air 24 externally across the coil. As depicted in FIG. 2A, the coil 12 may be repositioned, if desired, to provide for horizontal flow of the air 24 externally across the coil. In either the horizontal or vertical orientation of coil 12 the air flow across the coil may be opposite to that shown if desired.
Turning now to FIG. 4, the flat refrigerant coil module 32 utilized to form the modular coil 12 includes a single row of parallel, laterally spaced apart refrigerant heat exchange tubes 40 connected at their ends by conventional "U" fittings 42 to form a single refrigerant circuit having an open inlet end 44 and an open outlet end 46. Transversely connected to the heat exchange tubes 40 are a longitudinally spaced series of heat exchange fins 48. The coil 12 (FIG. 2) is operatively connected in the refrigeration circuit serving the system 10 by conventional refrigerant supply piping 50 connected to the tube inlets 44 of the coil modules 32 and provided with refrigerant expansion means 52, and refrigerant return piping 54 connected to the open tube outlets 46 of the four coil modules 32. If desired, the refrigerant flow through the coil modules 32 can be reversed simply by connecting the supply piping to the module outlets, and connecting the return piping to the module inlets.
With reference now to FIGS. 1 and 2, the coil 12 is supported within its associated housing 20 by means of two sets of interconnected support bars 55 secured to the opposite ends of the coil modules 32 and having slots 57 through which the U-fittings 42 outwardly pass. At their lower ends the bars 55 are connected to conventional drain pan means (not shown) that are fastened to housing 20. The coils depicted in FIGS. 2A, 3 and 3A are supported in a similar manner within their associated housings.
According to a key aspect of the present invention, as may be seen by comparing FIGS. 2 and 3, a series of identical flat refrigerant coil modules 32 may be utilized to form a series of modular, accordion-pleated refrigerant coils, having identical coil depths D and different nominal air conditioning tonnages depending upon the number of modules 32 utilized to form the particular accordion pleated coil. For example, the larger coil 56 shown in FIG. 3 is formed from ten of the identically sized modules 32 arranged in an accordion pleated fashion and operatively supported in an appropriately larger housing 20a having an open top side 60 and an open bottom side 62. As may be seen by comparing FIGS. 3 and 3A, the larger coil 56, like the smaller coil 12, may be positioned in either vertical or horizontal air flow orientations
The refrigerant coil module 32 illustrated in FIG. 4 representatively has a nominal air cooling capacity of 0.5 tons (6,000 BTU/HR.). Accordingly, the modular coil 12 has a nominal air cooling capacity of 2.0 tons, and the larger coil 56 has a nominal air cooling capacity of 5.0 tons. It will be appreciated, however, that the nominal air conditioning tonnage of each coil module 32 could be greater or smaller if desired. It will also be appreciated that the two illustrated coils 12 and 56 are merely representative of a wide variety of accordion pleated coils that could be formed utilizing different numbers of the identically sized coil modules 32, ranging from a two module coil to a coil having as many identically sized modules as is necessary to provide the required total air conditioning tonnage of the coil. For system applications, the minimum number of modules 32 utilized in a given coil is preferably three.
Compared to conventional "A"-coils utilized in systems such as the system 10 depicted in FIG. 1, the present invention's concept of utilizing selected numbers of identically sized coil modules to form accordion-pleated refrigerant coils of mutually different air conditioning capacities provides a variety of advantages. For example, as is well known, the production of A-coils of the different air conditioning capacities typically needed in a given equipment line necessarily entails the fabrication and inventorying of several differently sized refrigerant coil slabs used to form the A-coils. This, of course, requires increased production machinery and associated manufacturing floor space. Additionally, to accommodate the differently sized refrigerant coil slabs, it is necessary to produce a corresponding number of differently sized heat exchange fins. Moreover, the air conditioning capacity increments between successively larger A-coils, particularly at the upper end of the equipment's capacity spectrum, is typically considerably larger than 0.5 tons. This often results in the necessity of considerably oversizing the system's actual air conditioning capacity compared to the calculated air conditioning requirement for the conditioned space served by the system.
In the present invention, however, it is only necessary to fabricate and inventory refrigerant coil slabs of a single size to produce all of the different capacity coils needed in a typical equipment line. This advantageously reduces the overall coil manufacturing costs, thereby reducing the overall manufacturing costs of the system 10. Another advantage provided by the coil manufacturing method of the present invention is that the incremental air conditioning capacity increase between successively larger accordion pleated coils may be advantageously made uniform, and quite small, throughout the air conditioning capacity range of the particular equipment line. Using the illustrated coil module 32 as the "building block" for a series of different capacity air conditioning coils, this uniform increment would be 0.5 tons. The ability to economically provide this small air conditioning capacity increment permits the air conditioning capacity of the particular system to be very precisely matched to the actual air conditioning requirement of the conditioned space served by a particular system.
As previously mentioned, the coil depth D of each accordion-pleated coil fabricated from a selected number of the identically sized coil modules 32 may be easily made identical for each different capacity coil produced. This advantageously avoids the coil depth variation typically encountered when conventional A-coils are utilized. Accordingly, the coil housing length (in the air flow direction) necessary to accommodate each of the different capacity refrigerant coils of the present invention may be advantageously kept at a constant value regardless of which capacity air conditioning coil is installed on the furnace, air handler or heat pump.
The "face velocity" of an air conditioning coil is conventionally defined as the total volumetric air flow passing through the coil divided by the total effective upstream side surface area of the coil. Thus, the face velocity of a coil having a 2.0 square foot face area across which a 1200 cubic feet/minute air flow occurs would be 600 feet/minute. For many years it has been thought necessary to size refrigerant coils (such as conventional A-coils) used in the indoor sections of air conditioning equipment in a manner such that the coil face velocity is maintained within the 300-500 feet/minute velocity range.
Conventional coil design wisdom has been that a coil face velocity below about 300 feet/minute results in unacceptably low coil heat exchange efficiency, while a coil face velocity above about 500 feet/minute yields an unacceptable degree of condensate "blow through" and additionally raises the air pressure drop across the coil to an undesirable level.
Also in accordance with conventional coil design theory, the two refrigerant coil slabs used to define refrigerant A-coils are of a multi-row, multi-circuit construction for purposes of heat exchange efficiency. This multi-row/multi-circuit configuration, coupled with the coil face area needed to keep the face velocity of the coil within the traditional 300-500 feet/minute range, typically results in an air pressure drop across the coil that, as a practical matter, precludes the use in the coil of "enhanced" fins (i.e., fins of, for example, a lanced or louvered construction designed to increase the air-to-fin heat exchange efficiency. Typically, the increased pressure drop associated with this type fin enhancement is unacceptable in conventional refrigerant A-coils. Accordingly, conventional A-coils are usually provided with unenhanced fins.
The present invention significantly departs from this conventional refrigerant coil design theory in several regards. For example, as previously mentioned, each of the identically sized coil modules 32 is of a single row, single refrigerant circuit design. Additionally, the face area of each coil module 32 is preferably sized so that the face velocity of each multi-module coil, during operation of the air conditioning unit in which it is installed, is below the conventional 300 feet/minute lower limit. Preferably, such face velocity is in the range of from about 100 feet/minute to about 200 feet/minute. This face velocity reduction desirably and quite substantially reduces the air pressure drop across the coil, thereby reducing the power requirements for the furnace blower. Specifically, the modular coils of the present invention are preferably designed to operate with air pressure drops of less than about 0.10" .
In turn, this substantial air pressure drop reduction permits a closer fin spacing to be used in the coil modules 32, the module fin spacing preferably being in the range of from about 16 fins/inch to about 22 fins/inch (compared to the 10-14 fins/inch used in conventional A-coils). The lowered face velocity of the accordion-pleated refrigerant coils of the present invention also permits the fins 48 to be of an enhanced construction as illustrated in FIGS. 5 and 6. While a variety of fin enhancement designs could be used, a representative louvered fin enhancement design is illustrated in FIGS. 5 and 6, and comprises louvers 64 formed in the fins and extending at an angle relative to the fin bodies and positioned adjacent fin. Openings 66 resulting from the formation of the louvers 64. This fin enhancement desirably increases the air-to-fin heat exchange efficiency of the coil modules 32. In the illustrated preferred embodiment of the coil module 32, its tubes 40 are internally enhanced, preferably by the formation of a circumferentially spaced series of radial grooves 68 (FIG. 5A) formed in the interior side surface 70 of each tube and extending along its length. This internal tube enhancement desirably increases the tube-to-refrigerant heat exchange efficiency of each coil module 32.
While the accordion-pleated refrigerant coils of the present invention have been illustrated in conjunction with the evaporator section of a forced air furnace 10, it will readily be appreciated by those skilled in this art that the coils of the present invention could also be used in other air conditioning applications such as in heat pumps or other types of air conditioning apparatus. Additionally, downflow or horizontal flow units could also have the coils of the present invention incorporated therein.
The single row/single circuit configuration of each of the coil modules 32 serves to maximize the primary heat transfer performance (i.e., the tube-to-refrigerant heat transfer efficiency of the accordion-pleated refrigerant coil by maintaining a generally optimum refrigerant flow per circuit. When smooth coil tubes are utilized, this permits the optimization of refrigerant pressure drop. When internally grooved or otherwise internally enhanced coil tubes are used, this allows for the optimization of refrigerant pressure drop with shorter length tubes.
The single row/single circuit design of the coil modules also permits the secondary heat transfer performance (i.e., the air-to-fin heat exchange efficiency) of the coil to be maximized by allowing the maintenance of an optimum cfm/ton air flow ratio. In turn, this provides the previously mentioned low air face velocity for the coils of the present invention which yields reduced air side pressure drops, reduces water blow-off potential, and maintains the latent capacity for the coil. With plain (i.e., unenhanced) fins, this permits a considerably higher fin density than is achievable with conventional evaporator coils. With enhanced fins and unenhanced coil tubes, this permits a low fin density. On the other hand, when enhanced, internally grooved coil tubes are used, this permits a considerably higher enhanced fin density to match the shorter overall tubing length requirements.
The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims. | Using a series of identically sized, single row, single circuit refrigerant coil modules, fin/tube refrigerant coils of different nominal air conditioning tonnages are constructed by arranging different numbers of the identically sized modules in accordion-pleated orientations, with each modular coil having the same depth in the direction of intended air flow across the coil. Compared to conventional "A" coils used on the indoor side of air conditioning circuits, these accordion-pleated modular coils are more compact in the air flow direction, provide more coil surface area, permit lower coil face velocities with higher fin density, and significantly reduce the overall coil manufacturing costs since only one size of coil slab needs to be fabricated and inventoried to later assemble refrigerant coils of widely varying nominal air conditioning tonnages. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a process for the extraction of paraffins from mixtures of paraffins and alkane-sulfonic acids.
More particularly, the present invention relates to a process for the extraction of paraffins from mixtures of said paraffins with alkane-sulfonic acids, sulfuric acid (H 2 SO 4 ) slightly polar alcohols and water (H 2 O).
The mixtures of alkane-sulfonic acids and paraffins are obtained in particular by the process of sulfoxidation of n-paraffins, e.g., according to German Pat. No. 910,165, hereby incorporated by reference.
The above-mentioned mixtures present problems of recovery of alkane-sulfonic acids and their salts, and of paraffins, from the mixtures. The mixtures may also include an excess of sulfur dioxide SO 2 .
The presence of SO 2 is not a difficult problem to overcome. Distillation under a moderate vacuum, or stripping with oxygen (O 2 ) which is recycled to the sulfoxidation reactor, is enough to completely separate it from the solution.
For the separation of paraffins which are not converted into alkane-sulfonic acids by the above-mentioned sulfoxidation process, and of H 2 SO 4 , several processes have been suggested. European Pat. No. 131,913 suggests isolating paraffin sulfonic acids or paraffin sulfonates from the aqueous mixture produced by sulfoxidation of the paraffins, by adding to the mixture alcohols having 2 or 3 carbon atoms, separating n-paraffins as the upper phase, and then adding a non-polar water-immiscible organic solvent, and separating the aqueous H 2 SO 4 .
The product containing the possibly salified alkane-sulfonic acids is heated to the purpose of separating the solvent and the residual paraffins, and is possibly whitened with hydrogen peroxide.
The processes of the known art, including EP No. 131,913, suffer from the drawback that the separation of paraffins is very poor when the alcohol used has 2 or 3 carbon atoms. Subsequent heating must be carried out for a very long time, causing high energy consumption and danger of deteriorating the alkane-sulfonic acids or alkane-sulfonates.
It was surprisingly found that overcoming the drawbacks of the known art is possible by resorting to use of carbon dioxide CO 2 in the supercritical state for extraction of paraffins.
BRIEF DESCRIPTION OF THE DRAWING
The sole drawing illustrates the extraction method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The process according to the present invention comprises exposing raw charge containing the alkane-sulfonic acids with 12 to 18 carbon atoms, one or more aliphatic alcohols having a solubility in water lower than 7% by weight, H 2 O paraffins having 12 to 18 carbon atoms and water, to extraction by CO 2 under supercritical conditions. An extracted phase contains the paraffins and the present alcohol or alcohols along with CO 2 , and a refined phase containing the alkane-sulfonic acids, H 2 SO 4 and H 2 O
Sulfuric acid is then neutralized or eliminated by known means, so that the alkane-sulfonic acids, or their salts, are recovered.
The extraction step is preferably carried out under the following conditions: temperature from 32° C. to 80° C.; pressure from CO 2 critical pressure (73.8 bars) up to a value, depending on the operating temperature, such that the density of supercritical CO 2 is slightly lower than that of the mixture being submitted to the extraction, e.g., from 75 to 350 bars; CO 2 under supercritical conditions; and CO 2 /SAS ratio preferably from 1/1 to 50/1 (wherein SAS=secondary alkane-sulfonate or alkane-sulfonic acid).
The aliphatic alcohols having a solubility in H 2 O lower than 7% can be linear, branched or cyclic, and have from 5 to 12 carbon atoms. Preferred alcohols are 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 1-dodecanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-ethyl-1-hexanol, 2,6-dimethyl-4-heptanol, 3-ethyl-1-hexanol, 2,7-dimethyl-octanol, 2-octanol, cyclohexanol, cyclooctanol and mixtures of these alcohols.
Many separating agents can be used for separating H 2 SO 4 acid. Preferably, the same aliphatic alcohols mentioned above, having a solubility in water less than 7%, can be used.
The process according to the present invention can be carried out as a continuous process or as a batch process, and is illustrated by the following examples in a non-limiting way.
EXAMPLE 1
The laboratory-size extraction equipment as schematically shown in FIG. 1 was used.
FIG. 1 shows a refrigeration cycle for condensing CO 2 in heat exchanger 8. Liquid CO 2 is pumped by membrane pump 2 to pre-heater 3 and then to the extracting unit 4. The temperature of preheater 3 and extracting unit 4 is maintained constant by circulating H 2 O coming from a thermostatic bath. Pressure in extracting unit 4 is maintained constant at the desired value by means of regulator 5 and actuation valve 6.
The CO 2 and the products extracted from the raw material charged to extracting unit 4 and outflowing from actuation value 6, leaves the supercritical fluid in separation unit 7. Thereafter, CO 2 evaporates and is condensed in heat exchanger 8. The CO 2 is then sent back to the already described cycle, while the extracted phase remains inside the separation unit 7. any required CO 2 is fed into the cycle at inlet 9.
Separation unit 7 is provided with two diametrically opposite glass windows so the level may be checked visually. The level is kept constant by adjusting the temperature of water coming from a second thermostatic bath. The pressure in separation unit 7 is kept constant by means of a pressure switch, which controls the refrigerating cycle. Inside the extraction unit 4, a cylindrical vessel can be provided, which has both its cover and bottom plates made from porous sintered steel, and to which the extraction-undergoing raw product can be charged. In the preferred form, the extracting unit is packed with stainless steel bodies, which are kept blocked by a demister.
Pump 10 is used to deliver the raw product to extraction, for continuous operation. The refined product is discharged through valve (11).
Inside the vessel of extraction unit 4 was charged with, 126.1 g of a raw mixture of (C 12 -C 18 )-paraffin-sulfonic acids (secondary alkane-sulfonic acids=SAS), containing besides sulfonic and disulfonic acids:
______________________________________1-hexanol = 17.06% by weight(C.sub.12 -C.sub.18)-n-paraffins = 36.72% by weightH.sub.2 O = 11.22% by weightH.sub.2 SO.sub.4 = 0.78% by weight______________________________________
The raw mixture underwent extraction by supercritical CO 2 at 40° C. and under 150 bars for 1 hour (CO 2 /raw SAS weight ratio=14.54).
At the end of the test the products contained in separation unit 7 (extracted phase) and in extraction unit 4 (refined phase) were respectively discharged through valve 12 and valve 11 and analyzed. The amount of extracted paraffin, relative to that contained in charged raw SAS, was 99.4%. The relative amount of 1-hexanol was 91.9%.
Example 2
The equipment as described in Example 1 was used. 125 g of a raw mixture of SAS, having the composition as indicated in Example 1, was submitted to extraction by supercritical CO 2 at 50° C. and under 150 bars for 3 hours (CO 2 /raw SAS weight ratio=43.8). The analyses carried out on the extracted phase and on the refined phase at test end demonstrated that paraffin was extracted to an extent of 99.53% (based on paraffin contained in charged raw SAS), and 1-hexanol was extracted to an extent of 98.87%.
Example 3
The equipment as described in Example 1 was used. 119.3 g of a raw mixture of paraffin-sulfonic acids, having the composition as indicated in Example 1, was submitted to extraction by supercritical CO 2 at 60° C. and under 150 bars for 2 hours (CO 2 /raw SAS weight ratio=30.5). The analyses carried out on the extracted phase and on the refined phase at test end demonstrated that paraffin was extracted to an extent of 99.87% (based on paraffin contained in charged raw SAS), and 1-hexanol was extracted to an extent of 98.12%. | The invention relates to a process for the extraction of paraffins from mixtures obtained by the sulfoxidation of paraffins having a number of carbon atoms within the range of 12 to 18, which is characterized in that carbon dioxide is used as the solvent under supercritical conditions. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 10/769,634, filed Jan. 30, 2004, pending, which claims the benefit of U.S. Provisional Application Ser. No. 60/468,398, filed May 5, 2003, under 35 U.S.C. § 119(e), the contents of which are hereby incorporated in their entirety by this reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an infusion syringe apparatus for applying and monitoring fluid pressure applied to the intervertebral disk of the spinal column, or more specifically, monitoring of the pressure applied through a needle or cannula through the annulus fibrosus of the disk and into the nucleus pulposus thus allowing the diagnosis of diseased or ruptured disks. The field may further include fluid pressure-inducing syringes and methods involved in percutaneous translumental angioplasty (PTA) procedures.
2. State of the Art
Infusers utilized in diskography and balloon angioplasty are well known and established in medical practice. The tools typically applied to angioplasty have found application in other fields as well, including opening diseased carotid arteries, improving or reestablishing blood flow to the extremities of diabetics, and similar procedures. Similar tools have been used in the field of pain diagnosis and management related to orthopedic procedures related to the spine.
The number of failed or ineffectual spine surgeries has driven the development of new techniques for verifying the location of damage or injury in the vertebral column. Typically, these procedures involve the insertion of a curved or specifically shaped cannula or needle under the transverse process of the vertebra and around the inferior articular process and penetrating the annulus fibrosus. Application of fluid pressure to the nucleus pulposus will either go undetected, create relief from chronic pain, or induce a pain episode due to the pinching of a nerve. By the application of this technique to suspect vertebral disks, a physician can identify the pain locus and, thus, use the appropriate intervention to provide relief for the patient. This process is typically performed utilizing ionic contrast media, typically made from ionically bound iodine. This media allows the physician to view the procedure on a fluoroscope, which aids in needle positioning and visual diagnosis. Diagnosis is based on the ability, or inability, of the end of inter-vertebral disks to contain the contrast media when it is injected under pressure into the nucleus pulposus of the disk.
Typically, any syringe with a mechanism for measuring pressure has been used to measure the patency of the inter-vertebral disk. However, such syringes typically utilize a transducer mounted at the distal end of the syringe barrel which is in communication with the fluid path of the syringe. The presence of a non-transparent transducer and associated fixtures adjacent the fluid path prevents clear vision of bubbles in the contrast media or other imperfections that may be of concern in interventional procedures. Such devices are described in U.S. Pat. Nos. 5,021,046 and 5,084,060. Also, many such devices are awkward to use, are unduly complex or fail to provide a flexible fluid pressure adjustment.
SUMMARY OF THE INVENTION
The present invention includes a hand-operated syringe for applying pressure to a fluid within the syringe. The pressurized fluid interacts, directly or indirectly, with some physiology of the human body.
The syringe has a barrel, which may be constructed from a rigid material and, optionally, may be transparent. A plunger adapted to slide within the barrel and to apply pressure to fluid within the barrel may be configured to have two operative motions: 1) a first, sliding motion induced by direct hand motion, e.g., thumb force, at the proximal end of the plunger or some plunger extension attached generally axially to the proximal end of the plunger, whereby a rapid increase or decrease in the fluid pressure can be controllably caused to occur within the syringe barrel and 2) a second motion wherein the plunger is not freely slidable but has threads which interact with an adjustment mechanism, wherein the adjustment mechanism is engageable and disengageable to permit minute axial motion of the plunger and, thus, adjustment of the applied fluid pressure in controlled micro pressure adjustments.
The adjustment mechanism includes means whereby the threads on the plunger may be rapidly (e.g., instantaneously) disengaged to permit the plunger to slide freely thereby releasing the fluid pressure within the syringe barrel. The adjustment mechanism engages threads on the plunger or on a casing (sleeve) associated with and enveloping at least a portion of the plunger's external surface.
Various features of the syringe enable a user to completely operate the syringe with a single hand, leaving the user's other hand free to perform other tasks.
A further feature of the syringe is a pressure monitoring system whereby the pressure of the fluid within the barrel may be observed and, by appropriate adjustment of the plunger, such pressure may be controllably increased, decreased, or released. The pressure monitoring system of the syringe may provide a user with one or more warnings when the pressure reaches a threshold value.
A pressure sensitive transducer is fitted to communicate directly, or indirectly, with the fluid within the syringe barrel. Such transducers have conventionally been attached to the barrel generally at or near the distal end of the barrel, as illustrated in U.S. Pat. Nos. 5,021,046, 5,009,662, and 5,004,472 to Wallace (hereinafter collectively referred to as “the Wallace Patents”). While such positioning of the pressure sensitive transducer is acceptable for many purposes, the transducer and its associated fittings are not transparent and block the syringe operator's vision of the fluid within the portion of the barrel adjacent the transducer. This may be very disadvantageous if air bubbles exist within the fluid within the syringe barrel or within the tubing leading to a patient's body especially where the fluid is intended to enter a portion of the body, such as occurs with fluid injection into a spinal disk.
A significant advantage is realized by attaching the transducer to the distal end (pressure tip) of the plunger and having at least a part of the electronics which are part of the pressure-monitoring apparatus contained within the plunger. A tip of the plunger in which the pressure transducer is positioned may be configured to cover, but accurately transmit pressure to, the pressure sensitive transducer.
Placement of the transducer and, optionally, electronics on the plunger is especially useful inasmuch as the electronics may emit a wireless signal to cause a pressure reading to occur on a remote display, i.e., a display located on the exterior of the syringe barrel, a remote display not attached to the syringe barrel, including a display positioned at or near the proximal end of the syringe plunger or an extension attached thereto, or a display which is remote from the entire syringe.
The display may alternatively interact with the electronics associated with the pressure transduced by an electrical conductor. For example, the pressure transducer may communicate, by wires, with electronics or a display that is permanently secured to a proximal end of the plunger, or with a electronics or a display that is configured to be detachably coupled to the syringe plunger.
The electronics may be configured to ensure that the pressure sensitive transducer is initially exposed to an appropriate amount of pressure and, if not, indicate that there is a problem with the syringe.
A memory element may be associated with the electronics to store and facilitate transfer of data generated by use of the pressure sensing transducer. In addition, or alternatively, the electronics of a syringe according to the present invention may be provided with a communication element that facilitates the transmission of data generated by the pressure sensing transducer to external electronic devices, such as computers.
Other features and advantages of the present invention will become apparent to those in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of a syringe of the present invention;
FIG. 2 is a perspective view of the proximal portion of the syringe of FIG. 1 ;
FIG. 3 is an exploded view of a plunger of the syringe and a rotatable sleeve that encases the plunger;
FIGS. 4A and 4B are exploded views of components associated with the distal end of the plunger;
FIG. 5 is an exploded view that includes a perspective view of a tip that is associated with the distal end of the plunger to shield a pressure transducer of the syringe while accurately transmitting fluid pressure to the pressure transducer;
FIGS. 6A-6C include several views of a clamshell locking mechanism for a syringe of the present invention;
FIG. 7 is a cross-sectional perspective view of the syringe of FIG. 1 ;
FIG. 7A is a schematic representation of exemplary electronics that may be associated with a syringe according to the present invention;
FIGS. 8A-8C are perspective views of a syringe with a streamlined block-shaped head containing a display element of a syringe that incorporates teachings of the present invention;
FIG. 9 is a cross-sectional view of a plunger having electronics that transmit a wireless signal to a display element located at a proximal end of the plunger;
FIG. 10 is a perspective view of the syringe of FIGS. 8A-8C with a fanciful display holder; and
FIG. 11 is an exploded view of a plunger that includes a reusable electronics and display module which is detachable from the remainder of the syringe.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an external perspective view of a syringe 10 that incorporates teachings of the present invention. Syringe 10 includes an elongate barrel 14 and a plunger 11 disposed within barrel 14 .
Barrel 14 , which may be configured similarly to other syringe barrels that are known in the art, includes a connection element 20 , such as a luer lock or a slip socket type connection element, at a distal end 14 d thereof. By way of example only, connection element 20 may be configured to secure a bonded extension line to barrel 14 , in pressure-tight fluid communication therewith. Barrel 14 may also include rings or other grasping elements 15 a and 15 b at or near the proximal end 14 p thereof. Grasping elements 15 a and 15 b may be held by the index finger and the middle finger of a health care professional (e.g., a physicial or technician) or other individual who is using syringe 10 .
Plunger 11 may have a ring or other grasping element 12 at the proximal end 11 p thereof. Grasping element 12 of plunger 11 may be configured to facilitate manipulation of plunger 11 (e.g., longitudinal movement of plunger 11 through barrel 14 and, thus, the fluid pressure generated by syringe 10 ) with the thumb or other digit of an individual who is using syringe 10 , or with automated apparatus for controlling the operation of syringe 10 .
In the illustrated embodiment of syringe 10 , grasping elements 12 , 15 a , and 15 b are positioned in a triangular arrangement, in which they are in close proximity to one another. Such an arrangement facilitates operation of syringe 10 with a single hand of an individual (e.g., the index finger, thumb, and middle finger of one hand, as previously described). By allowing an individual to operate syringe 10 and, thus, to perform any procedure in which fluid pressure is directly or indirectly applied to any human body part, including a spinal disk or an artery, with a single hand, the individual is free to use his or her other hand to accomplish additional tasks, particularly those associated with the procedure being performed.
The Plunger
With reference to FIG. 3 , the majority of plunger 11 is an elongate, at least partially hollow element, which has an outer surface 27 and includes an inner bore 26 that is located for communication with a distal end 11 d of plunger 11 . Additionally, plunger 11 may include a somewhat annular end cap 19 at distal end 11 d thereof, which is configured to retain a pressure transducer 24 and transducer retainer 31 in place relative to inner bore 26 , while allowing for the communication of fluid pressure from the exterior (at least at distal end 11 d ) of plunger 11 to pressure transducer 24 .
Pressure transducer 24 may comprise any transducer or group of transducers that is suitable for accurately measuring fluid pressures within one or more ranges that may be encountered by use of syringe 10 . Exemplary transducers that may be employed as pressure transducer 24 include those described in the aforementioned Wallace patents, the disclosure of each of which is hereby incorporated herein in its entirety by this reference.
A quantity of gel 24 G of a type known in the art (e.g., a silicone gel) may also be disposed within an aperture 19 A of end cap 19 and over a pressure-sensing region 24 P of pressure transducer 24 to provide some protection thereto. Of course, gel 24 G is of a type that accurately transmits fluid pressure present at distal end 11 d of plunger 11 to pressure-sensing region 24 P and may, therefore, also be referred to as a “force transmitting gel.”
Transducer retainer 31 is a small, somewhat annular element. Transducer retainer 31 is configured to be securely positioned relative to inner bore 26 and end cap 19 . Features of transducer retainer 31 are configured to be secured to pressure transducer 24 . Transducer retainer remains in a fixed position within inner bore 26 and, along with end cap 19 , fixes pressure transducer 24 in position along plunger 11 during movement of plunger 11 and when high fluid pressures are present within the lumen of barrel 14 ( FIG. 1 ).
As shown in FIGS. 4A and 4B , end cap 19 includes a detent 33 at a distal end 19 d thereof. Detent 33 is configured to receive corresponding features on the interior of a rubber plunger tip 32 , which seals against an inner surface of barrel 14 . As depicted, plunger tip 32 includes an aperture 32 a therethrough to facilitate the communication of fluid pressure to pressure transducer 24 .
Alternatively, with reference to FIG. 5 , a plunger tip 32 ′ that covers a pressure-sensing region 24 P of pressure transducer 24 may be positioned over distal end 11 d of plunger 11 ( FIG. 3 ), such as over the illustrated end cap 19 that is to be secured to distal end 11 d . Plunger tip 32 ′ includes a somewhat rigid sealing element 32 S′ at the outer periphery thereof, which surrounds a central element 32 C′.
Rigid sealing element 32 S′ of plunger tip 32 ′ is configured to be secured to an end of plunger 11 . Without limiting the scope of the invention, rigid sealing element 32 S′ may be configured to be secured to end cap 19 , as illustrated. Accordingly, rigid sealing element 32 S′ may include an internally protruding ridge (not shown) that is configured to be inserted into and engaged by detent 33 of end cap 19 . Additionally, rigid sealing element 32 S′ of plunger tip 32 ′ is configured to seal against an inner surface of barrel 14 ( FIG. 1 ).
Central element 32 C′ of plunger tip 32 ′ is configured to be disposed over, to substantially shield, and to accurately transmit fluid pressure to pressure-sensing region 24 P of pressure transducer 24 and, optionally, gel 24 G located thereover. In the illustrated example, central element 32 C′ is disposed over an aperture 19 A of end cap 19 , through which fluid pressure is communicated to pressure-sensing region 24 P. Central element 32 C′ may comprise the majority of a distal surface 32 d ′ of plunger tip 32 ′ (e.g., about 60% to about 70% of the area of distal surface 32 d ′). By way of example only, central element 32 C′ may be a pliable element that substantially shields pressure transducer 24 from fluids that are present at distal end 1 d of plunger 11 ( FIG. 3 ). The thickness of such an embodiment of central element 32 C′ and the material (e.g., silicone) from which such a central element 32 ′ is formed are together configured to accurately transmit fluid pressure that is present at distal end 1 d of plunger 11 to pressure-sensing region 24 P of pressure transducer 24 .
Other arrangements for securing a pressure transducer 24 to a plunger of a syringe may also be utilized and, thus, are also within the scope of the present invention.
Electronics
Turning to FIG. 7 , which is a perspective, sectional view of syringe 10 taken along the central longitudinal axis of plunger 11 and barrel 14 thereof, inner bore 26 may extend along substantially the entire length of plunger 11 . Additionally, plunger 11 may include an enlarged, hollow region 37 at proximal end 11 p thereof with an interior 37 I that communicates with inner bore 26 . It is within interior 37 I that an electronics assembly 38 may be incorporated to connect pressure transducer 24 to a display element 39 ( FIGS. 8A through 8C ), which may be located at proximal end 11 p of plunger 11 .
Wires (not shown) may extend through inner bore 26 to connect pressure transducer 24 with corresponding elements of the electronics assembly, as known in the art. Alternatively, inner bore 26 may facilitate wireless communication between pressure transducers and corresponding elements of the electronics assembly, as described in further detail hereinafter.
Electronics assembly 38 may, as shown in FIG. 7A , include one or more microcontrollers 38 C or other processing elements of a type known in the art, which receive signals from pressure transducer 24 , process the received signals, then output a signal that causes display element 39 to display a numeric indicator of the pressure that has been sensed at distal end 11 d of plunger 11 by pressure transducer 24 . Electronics assembly 38 also includes a power source 38 B, such as a battery, which may have a voltage (e.g., 3 V) sufficient for operating microcontroller 38 C, display element 39 , and other elements that are part of or otherwise associated with electronics assembly 38 .
Communication between power source 38 B and other electronic elements may be controlled by a switch of a known type. Alternatively, a power inhibitor 38 I, which is formed from electrically insulative material (e.g., plastic, paper, plastic-coated paper, ceramic, glass, etc.) may be positioned between power source 38 B and a contact (not shown) to power source 38 B. When power inhibitor 38 I is removed, electrical communication between power source 38 B and the contact and, thus, electronic components of syringe 10 ( FIG. 7 ) in communication with the contact is established.
Each time power is initially provided to microcontroller 38 C, such as when power is initially provided to microcontroller 38 C, microcontroller 38 C may be programmed to enter a “zero loop.” In the “zero loop,” microcontroller 38 C determines whether less than a minimum threshold or more than a maximum threshold in differential pressure (e.g., relative to atmospheric pressure, which is equal to zero) is being measured by pressure transducer 24 ( FIG. 7 ). As an example, and not to limit the scope of the present invention, the maximum threshold may be set at about 4 to about 4½ psi, which accommodates the typically 2½ psi variation between atmospheric high and low pressures, as well as variations in pressure at different elevations. Such programming of microcontroller 38 C may permit microcontroller 38 C to receive pressure signals from pressure transducer 24 for a given period of time (e.g., ten seconds), to provide a more accurate sample of the measured pressure. If the fluid pressure that has been measured by pressure transducer 24 exceeds the maximum threshold, microcontroller 38 C shuts down, causes display element 39 to shut down, or go “dark” or “blank,” and restarts, automatically reentering the “zero loop.” When the fluid pressure that is initially measured following provision of power to microcontroller 38 C is at or below the maximum threshold, microcontroller 38 C may output some indication that pressure transducer 24 has been calibrated, such as by causing display element 39 to show the characters “CAL.” Programming of this type prevents inaccurate pressure measurements that may be caused accidentally or by misuse of syringe 10 and provide a user of syringe 10 with an indication of the existence of a problem.
An improper initial pressure may be caused by a variety of factors, including, without limitation, if gel 24 G ( FIG. 5 ) sticks to an adjacent area of plunger tip 32 ( FIGS. 4A and 4B ) (which may result in a lower-than-actual) pressure reading by pressure transducer 24 ), leaving a cap over connection element 20 ( FIG. 1 ) of barrel 14 ( FIG. 3 ), the presence of bubbles in a fluid within the lumen of barrel 14 , a premature build-up of pressure within barrel 14 (e.g., by using syringe 10 before power is provided to microcontroller 38 C), or otherwise. In reaction to the repeated initialization and shutting down of microcontroller 38 C as a result of the detection of an undesirable fluid pressure as a “zero loop” is being effected, a user may be prompted to evaluate syringe 10 and its various components and correct the problem, then restart microcontroller 38 C.
The display element 39 ( FIGS. 8A and 8B ) of syringe 10 ( FIG. 7 ) that communicates with microcontroller 38 C may comprise any suitable type of display known in the art. By way of nonlimiting example, display element 39 may comprise one or more groups of light emitting diodes (LEDs), each of which may be illuminated in a variety of combinations to form a corresponding variety of characters (e.g., numbers, letters, etc.). As another example, display element 39 may comprise a liquid crystal display of a known type, which likewise includes elements that may be stimulated into displaying combinations of lines that form a variety of different characters. Of course, any other type of display that would be suitable for displaying pressure information and any other desired information that has been processed and output by microcontroller 38 C (e.g., in the form of characters, images, etc.) may also be used in a syringe 10 of the present invention without departing from the scope of the present invention.
In addition to processing pressure signals that have been received from pressure transducer 24 ( FIG. 7 ), a microcontroller 38 C of electronics assembly 38 that incorporates teachings of the present invention may be programmed to cause any displayed characters to flash when it may be desirable to catch the attention of an individual who is operating syringe 10 . Alternatively or additionally, microcontroller 38 C may transmit signals to other output elements (not shown), such as audio outputs, vibratory outputs, or the like, to provide a caution or warning to an individual who is using syringe 10 . Such signals may be provided merely for information purposes, or for safety purposes. For example, if the fluid pressure measured at distal end 11 d of plunger 11 by pressure transducer 24 exceeds a threshold value (e.g., 125 psi, which is approaching the upper limit of pressure that should be encountered during discography), microcontroller 38 C may cause characters of display element 39 (or images or a backlight on any other type of display element), which may show a value representative of the measured pressure, to repeatedly flash.
In some embodiments of syringe 10 , electronics assembly 38 may include a memory element 38 M in communication with microprocessor 38 C. Memory element 38 M may, by way of example only, comprise a flash-type memory (i.e., flash EEPROM) associated with microprocessor 38 C. Such a memory element 38 M may be an internal element, which is permanently associated with microprocessor 38 C, or an external element, which is configured to temporarily communicate with microprocessor 38 C by way of a communication element 38 P (e.g., a USB port), then be removed therefrom and used elsewhere. Of course, communication elements 38 P that communicate with microcontroller 38 C may also be used for any other suitable purpose, including for establishing communication between microcontroller 38 C and a processing element (e.g., a processor) of a computer (e.g., for further evaluation of transmitted data, to transfer data from memory element 38 M for storage on a centrally accessible file, etc.).
Internal memory elements 38 M may be used with syringes 10 that include reusable electronics assemblies 38 . External memory elements 38 M are particularly useful when transfer of the data stored thereon is desirable, or when syringe 10 , including electronics assembly 38 and display element 39 thereof, is disposable.
A further embodiment of syringe according to the invention incorporates a wireless transmission of pressure information from the pressure transducer to the read-out display at the proximal end of the syringe. The transducer analog output may be introduced to a wireless transmitter to transmit an analog signal to the distal end of the syringe, where a wireless receiver receives the signal, and converts it to a digital signal, which is introduced directly into the digital read-out display.
The wireless transmitter may be an infrared processor/transmitter which receives the analog electrical signal, converts it into an infrared analog signal which is emitted from an infrared (IR) emitter, which has a battery associated therewith. The IR analog signal may be transmitted through the body of the syringe through an open channel to an IR analog receiver/converter at the proximal end of the syringe. Alternatively, the electrical signal may be converted into a digital IR or other digital wireless signal to be received by an appropriate receiver. An optical fiber may be advantageously used for precise IR transmission from the IR transmitter to the IR receiver. Further, a digital signal may be sent via an electrical conductor between the transducer/transmitter and the receiver/display.
The IR signal may include pulses that flash at a rate which is indicative of a particular pressure measurement by pressure transducer 24 ( FIGS. 3 through 5 ), or that are embedded with data and, thus, pulse in a manner that is indicative of the embedded data (e.g., somewhat like Morse Code).
The disclosure of U.S. Pat. Nos. 5,215,523 and 5,387,194 to Williams/Call et al., the disclosures of both of which are hereby incorporated herein in their entireties by this reference, especially with respect to means and systems for wireless transmission of signals produced by a pressure transducer. Also, incorporated herein is U.S. Pat. No. 5,021,046 to Wallace, especially the disclosure relating to pressure transducers.
Also, wireless transmission of pressure transducer information by radio signals may be utilized within the syringe for the purposes of the invention. However, radio signals may interfere with various other equipment in an operating room-type of environment and would generally be contraindicated where such a syringe was to be utilized upon a patient having a pacemaker.
FIGS. 8A through 8C are perspective views of a syringe with a pressure display head located in a display holder having a thumb aperture located between the display and the plunger.
FIG. 8A is a perspective view of a syringe 10 ′ with a pressure display element 39 located in a display holder 37 ′ having a thumb aperture 12 ′ located between the display and the plunger. Syringe 10 ′ may include a wired connection between the pressure transducer and the pressure display or a wireless transmission system such as that illustrated in FIG. 9 .
FIG. 8B and 8C show an elevational view and plan view, respectively, of syringe 10 ′ (i.e., an infuser) of FIG. 8A . The display holder 37 ′ of syringe 10 ′ is unique in appearance, as can be seen in FIGS. 8A , 8 B and 8 C. Additionally, the style, shape and juxtaposition of the various elements of the syringe further provide a syringe 10 ′ of a distinctive appearance.
FIG. 8C shows the bottom of the display holder 37 ′, assuming that the surface in which the display is embedded is denoted the top surface, which is visible in FIGS. 8A and 8B .
The syringe 10 ′ of FIGS. 8A , 8 B, and 8 C has the thumb preferably inserted in thumb aperture 12 ′ from the bottom so that the display element 39 will face upwards to the technician operating syringe 10 ′.
An embodiment of the invention is shown in FIG. 9 illustrating in perspective view a hollow plunger 11 having a pressure transducer 24 located at or near plunger tip 32 (distal end), which transducer is electrically connected to an electronics system 40 which wirelessly transmits its output signal (IR or radio frequency (RF)) to a remote receiver/pressure display 41 system. Display element 39 may be located at or near the proximal end of plunger 11 or at a remote location separate from plunger 11 , e.g., attached to an external surface of The syringe or entirely separate and remote from the syringe, e.g., on a support which positions the pressure display element 39 visible to one or more members of a team involved in an infusion procedure.
The signal transmitted from the electronics system to the display may be an analog or digital signal. If the signal is an analog signal then the pressure display includes a receiver mechanism which receives the signal and converts the analog signal to a digital signal suitable for being displayed as a pressure in millimeters of mercury, pounds per square inch or other useful pressure units. The electronics may further include a memory device whereby the total infusion procedure is recorded in terms of elapsed time and regular (substantially continuously, if desired) pressure recordings so that a history of the entire infusion procedure may be later downloaded for permanent storage.
A substantially hollow plunger having an internal pressure sensing mechanism, e.g., pressure transducer, in the tip which is in direct or indirect contact with fluid of a syringe being pressurized has many advantages, many of which have been enumerated herein. One such advantage is that a direct pressure reading may be displayed in a display incorporated in the proximal end of the plunger. Also, in a structure such as described herein, a fluid, preferably liquid, may be contained within the hollow plunger to contact a dynamic (diaphragm) type-pressure influenced mechanism and conduct the received pressure through said fluid, preferably liquid, to a pressure transducer/display in the proximal end of the plunger.
In such a structure the pressure experienced at the tip of the plunger is transmitted by a fluid conductor to a pressure transducer or other pressure metering means, e.g., an analog pressure meter, at the proximal end of the plunger. Such a structure permits all the electronics necessary for a digital display, e.g., pressure transducer, analog/digital converter and digital signal receiving display to be directly coupled to one another and located at or near the proximal end of the hollow plunger.
The display at the proximal end of the syringe may be incorporated into a housing of the varying shapes and designs shown herein which accommodate functional purposes. The shape of the display housing shown in FIGS. 8A through 8C may be somewhat fanciful to provide a smooth aesthetic appearance while not diminishing its attributes as a display holder and thumb engagement device. A further perspective view of the syringe of FIGS. 8A through 8C is shown in FIG. 10 . The view is at an oblique angle from the rear of the syringe.
FIG. 11 illustrates another embodiment of syringe 10 ″ according to the present invention, which includes wires 46 that extend from the pressure transducer 24 thereof. Modular electronics 38 ″ may be “plugged into” and “unplugged” from an electrical connector 44 , or plug, of known type of syringe 10 ″. Electrical connector 44 may be positioned adjacent to distal end 11 d of plunger 11 in a relatively fixed position.
Electrical connector 44 includes pins or receptacles 45 that communicate with one or more wires 46 . Wires 46 , in turn, communicate with corresponding contacts (not shown) of a pressure transducer 24 .
Modular electronics 38 ″ also include an electrical connector 47 , which is configured complementarily to electrical connector 44 and, thus, includes receptacles or pins 48 that are positioned and configured to cooperate and electrically communicate with corresponding pins or receptacles 45 of electrical connector 44 . Receptacles or pins 48 have wires 49 coupled thereto, which establish communication with one or more of components (e.g., microcontroller 38 C, power source 38 B, etc.) of an electronic assembly 38 of modular electronics, such as the exemplary electronic assembly 38 depicted in FIG. 7A .
By way of example only, electrical connectors 44 and 47 may comprise electronic (e.g., computer) communication ports of known type that are configured to mate with one another.
As modular electronics 38 ″ may be uncoupled from syringe 10 ″, modular electronics 38 ″ may be used repeatedly, with a plurality of disposable syringes 10 ″. Additionally, modular electronics 38 ″ may be coupled with a communication port of a computer or other electronic device to facilitate programming of one or more elements (e.g., microcontroller 38 C) of electronic assembly 38 , data transfer (e.g., from memory element 38 M of electronic assembly 38 ), or for any other reason to establish communication between one or more components of electronic assembly 38 and an external electronic device.
Elements for Positioning the Plunger
With returned reference to FIGS. 1 through 3 , syringe 10 may additionally include means for adjusting the position of plunger 11 within barrel and, thus, for controlling the amount of pressure generated by syringe 10 . The means for adjusting may be configured to provide for fine adjustments of the position of plunger 11 and, thus, of the pressure generated by syringe 10 , as well as for larger adjustments.
Fine adjustments of the position of plunger 11 within barrel 14 may, for example, be accomplished with the depicted rotatable sleeve 16 , which is an elongate, hollow, cylindrical element that is disposed, as a sleeve, over and may be supported by at least a portion (e.g., a smooth portion) of outer surface 27 of plunger 11 . After rotatable sleeve 16 is slid over plunger 11 , a friction reduction washer 30 may be placed over outer surface 27 of plunger 11 , adjacent to distal end 16 d of rotatable sleeve 16 , to act as a friction reducing bearing between rotatable sleeve 16 and end cap 19 and, thus, to facilitate the substantially free rotation of rotatable sleeve 16 relative to end cap 19 . Rotatable sleeve 16 includes threads 13 on an exterior surface thereof and a control element 23 , such as the depicted wheel, at a proximal end 16 p thereof.
Threads 13 may be engaged by corresponding features (not shown) of a locking mechanism 17 , which is associated with and remains in a substantially fixed location relative to proximal end 14 p of barrel 14 . Locking mechanism 17 includes a housing 17 H and a locking element 17 L. Apertures 25 H and 25 L of housing 17 H and locking element 17 L, respectively, accommodate rotatable sleeve 16 . Housing 17 H is secured in place relative to proximal end 14 p of barrel 14 (e.g., by being molded integrally therewith, bonded thereto, etc.). Locking element 17 L is associated with housing 17 H and may be moved relative thereto.
As shown in FIG. 2 , housing 17 H is configured to captivate locking element 17 L in such a way that locking element 17 L may slide laterally relative to housing 17 H and radially relative to barrel 14 . In the illustrated example, opposite ends of locking element 17 L are exposed through housing 17 H to facilitate movement thereof. Aperture 25 H of housing 17 H has dimensions that facilitate the substantially free longitudinal movement of rotatable sleeve 16 and, thus, the plunger 11 therein transversely thereto. Aperture 25 L of locking element 17 L may comprise a keyhole-shaped opening, which may include two overlapping circular apertures, one having a larger diameter than the other. The smaller side of aperture 25 L has dimensions that facilitate engagement of threads 13 of rotatable sleeve 16 , while the dimensions of larger side of aperture 25 L are configured not to engage threads 13 and, thus, allow substantially free travel of plunger 11 longitudinally through barrel 14 .
Locking element 17 L may be placed in a locked, or set, position by causing an interior rib 18 , which is located at an edge of the smaller side of aperture 25 L, to engage threads 13 of rotatable sleeve 16 (e.g., by insertion within a groove of threads 13 ). When in an unlocked, or released, position, interior rib 18 disengages threads 13 of rotatable sleeve 16 , permitting substantially longitudinal movement of rotatable sleeve 16 and, thus, plunger 11 through barrel 14 .
When locking mechanism 17 is in a locked position (e.g., slid to one side), fine, or minute, adjustments of the position of plunger 11 within barrel 14 and, thus, associated fine or minute adjustments to volume or pressure within the lumen of barrel 14 may be made by use of control element 23 . For example, if control element 23 comprises a wheel which is positioned and configured to be rotated by the thumb of an individual (and, thus, may also be referred to herein as a “thumbwheel”), displacement of plunger 11 relative to barrel 14 may be generated by rotation of control element 23 . Rotation of control element 23 in a direction that forces rotatable sleeve 16 against a flange, such as that provided by a proximal edge 19 p ( FIG. 4B ) of end cap 19 , against which distal end 16 d of rotatable sleeve abuts, thereby forcing plunger 11 distally along the length of barrel 14 . As fluid pressure within the lumen of barrel 14 may exert force on plunger 11 , rotation of control element 23 and, thus, rotatable sleeve 16 in the opposite direction (i.e., such that rotatable sleeve 16 moves proximally relative to barrel 14 ), plunger 11 may move proximally relative to barrel 14 . The axial advancement or retraction of plunger 11 effected by rotation of control element 23 is very slight, thus, minute adjustments of fluid pressure are readily accomplished. The ability to achieve such precise adjustment of fluid pressure is desirable in a number of medical procedures, including, but not limited to, discography and angioplasty procedures.
When locking mechanism 17 is in an unlocked position (e.g., slid to the other side), plunger 11 may be substantially freely moved along the length of barrel 14 by placing force on proximal end 11 p thereof (e.g., as an individual places his or her thumb within the depicted grasping element 12 , then moves his or her thumb). Thus, larger adjustments of the position of plunger 11 may be made when locking mechanism 17 is in an unlocked position.
When fluid pressure within the lumen of barrel 14 increases, positioning of locking mechanism 17 in an unlocked position, so as to release threads 13 , allows the fluid pressure to force plunger 11 proximally through barrel 14 , facilitating a rapid, substantially instantaneous reduction of pressure (e.g., to zero additional pressure exerted by syringe 10 ) within barrel 14 and, thus, within a portion of the body of a subject with which the lumen of the barrel 14 is in fluid communication. This feature is desirable since many procedures may require a substantially instantaneous release of fluid pressure to prevent or minimize damage to a body part that is being treated or investigated.
While a particular embodiment of slide-lock mechanism has been illustrated and described herein, other locking mechanisms may be also effectively utilized on syringes that incorporate teachings of the present invention. For example, a two-piece clam-shell, spring-loaded mechanism, such as that shown in FIGS. 6A through 6C , can be usefully employed. Two clam-shaped elements 34 and 35 are hinged at their closed ends and spring-biased to be in a “closed” position, as shown in FIG. 6A . A rotatable cam 36 , which has an elongate cross-section taken transversely to the length thereof, is positioned between clam-shaped elements 34 and 35 , at the open ends thereof. While the smaller dimension of rotatable cam 36 separates clam-shaped elements 34 and 35 , they remain in the “closed” position. When the rotatable cam is rotated, larger dimensions thereof separate the open ends of clam-shaped elements 34 and 35 , forcing them apart from one another and into an “open” position, as shown in FIGS. 6B and 6C . When clam-shaped elements are in the “open” position, a threaded rotatable sleeve 16 or a threaded plunger 11 ′ may slide freely therebetween.
Alternative mechanisms for locking and unlocking threaded rotatable sleeve 16 ( FIGS. 1 through 3 ) or a threaded plunger ( FIGS. 6A through 6C ) in a fixed position to provide minute pressure adjustment may be also employed without departing from the scope of the present invention, including, without limitation, the locking mechanisms that are disclosed in U.S. Pat. Nos. 5,860,955, 5,433,707, and 5,685,848, the disclosures of which are hereby incorporated herein in their entireties by this reference.
Having a rotatable sleeve 16 that may be engaged or disengaged by a locking mechanism (e.g., locking mechanism 17 ( FIGS. 1 and 2 ) or locking mechanism 17 ′ ( FIGS. 6A through 6C )) permits minor axial adjustments of plunger 11 without requiring that plunger 11 itself be rotated. Thus, any features of syringe 10 , such as display element 39 ( FIGS. 8A through 8C ), that are affixed at proximal end 11 p of plunger 11 remain in a constant position (and, in the case of display element 39 , in a continuously visible position).
If, however, pressure transducer 24 ( FIGS. 3 through 5 ) and its associated electronics (not shown) are integrated into a plunger, with the electronics being configured to transmit wireless signals to remote processing or display apparatus, then the plunger 11 ′ ( FIGS. 6A through 6C ) itself may be threaded, at least near its proximal end 11 p , for engagement with a suitable locking mechanism (e.g., locking mechanism 17 ( FIGS. 1 and 2 ) or locking mechanism 17 ′ ( FIGS. 6A through 6C )) and, thus, rotated to accomplish minute axial adjustment of the position of plunger 11 along the length of barrel 14 . The grasping element 12 associated with such a plunger 11 may be configured (e.g., a ring with an enlarged open diameter) to facilitate operation of plunger 11 with an individual's thumb regardless of slightly offset rotation of grasping element 12 .
Syringes 10 that include grasping elements 12 (e.g., a ring), electronics, and/or display element 39 (and, of course, wireless connections or rotatable connection elements) that are secured in position relative to proximal end 11 p of plunger 11 in such a way that they substantially freely rotate relative to proximal end 11 p are also within the scope of the present invention.
Referring again to FIG. 1 , it is currently preferred that an individual who uses syringe 10 be able to control the position (i.e., locked or unlocked) of locking mechanism 17 with the same hand that he or she is using to hold or operate other features of syringe 10 . For example, the individual may use his or her thumb to set (i.e., lock) or release (i.e., unlock) locking mechanism 17 , while holding grasping elements 15 a and 15 b with the index finger and middle finger of the same hand. The location of control element 23 vis-a-vis grasping elements 12 , 15 a , and 15 b may likewise readily permit an individual using syringe 10 to remove his or her thumb from grasping element 12 and place it upon control element 23 to rotate control element 23 to achieve minute fluid pressure adjustments, further facilitating continuous one-handed operation of syringe 10 .
Use of a syringe 10 that incorporates teachings of the present invention facilitates control over the pressure generated or measured thereby with a single hand, while the individual operating syringe 10 may use his or her other hand to perform other tasks. For example, in discography procedures, the individual's free hand may be used to position a stylus that communicates with syringe 10 , while the hand that holds syringe 10 is used to inject additional fluorescent media to provide additional illumination on a fluoroscope and, thus, a better idea of the actual location of an end of the stylus.
Although the foregoing description contains many specifics, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some of the presently preferred embodiments. Similarly, other embodiments of the invention may be devised which do not depart from the spirit or scope of the present invention. Features from different embodiments may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions and modifications to the invention as disclosed herein which fall within the meaning and scope of the claims are to be embraced thereby. | A syringe configured for communication with a tubular member insertable into the body of a subject includes a pressure transducer integrally mounted in the plunger thereof, under a tip of the plunger, such that the force applied by the plunger to fluid within a barrel of the syringe is transmitted to the transducer. A resulting electronic signal is converted to a display value for aiding a physician. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to telephone answering equipment and more particularly to such equipment which is especially suited for use by radio broadcast stations and the like.
Interface units are available to interface between incoming and outgoing telephone lines and various equipment in a broadcast studio such as a playback deck, or a frequency extender or the like. For example, such interfaces are used for commonly offered services such as weather information lines, sports information lines and the like and in the running of radio contests. In these instances, each telephone line is connected through an interface to a playback deck which contains a prerecorded message for the caller. Such interfaces are also used in remote audio feed situations where the telephone conversation is sent over telephone lines to the studio.
Presently used interface units for these various purposes could be improved. For example, many of these interface units need auxiliary power supplies which requires additional space and add additional weight to the system. Moreover, currently interface units are relatively limited in function and inflexible in use. Separate units of differing types may be needed to perform various of the different functions listed above. In addition, a separate playback deck is generally required for each telephone line using the presently available interfaces. In the information line application, the presently available systems sometimes connect the caller to the prerecorded message in the middle of the message and then attempt to cut off the caller after a predetermined amount of time. However, on occasion the caller is cut off before the entire message is heard. Present interface units are also relatively bulky in general or must be mounted near their power supplies or other equipment such as a frequency extender, which require that they be hidden in a cabinet or the like where their various indicators such as an on-line indicator cannot be seen.
SUMMARY OF THE INVENTION
Among the several objects and features of the present invention may be noted the provision of an interface unit which requires no auxiliary power supply.
Another object of the present invention is the provision of such an interface unit which is relatively flexible and capable of performing a number of functions.
A third object of the present invention is the provision of such an interface unit and system which uses a single playback deck for a plurality of telephone lines.
A fourth object of the present invention is the provision of such a system which can always start a prerecorded message at the beginning of the message.
Another object of the present invention is the provision of such a system which provides for various modes of operation including studio or remote control of the unit and playback deck control of the interface unit.
A sixth object of the present invention is the provision of such a system which allows remote audio feeds to be readily supplied through the interface unit.
Another object of the present invention is the provision of such an interface unit which is relatively small in size and provides easily seen indications of line use.
Another object of the present invention is the provision of such an interface unit which causes relatively low loss between the telephone line and the device to which the telephone line is to be connected.
Other objects and features will be in part apparent and in part pointed out hereinafter.
Briefly, a multiline telephone answering system of the present invention includes a playback deck for supplying a prerecorded message and a plurality of interface units for interconnecting a plurality of telephone lines and the playback deck. Each interface unit is associated with a particular telephone line and includes circuitry for supplying a start signal to the playback deck when its associated line is ringing. Each interface unit further includes circuitry responsive to the state of the playback deck for connecting its respective telephone line to the playback deck only at the start of the prerecorded message and for inhibiting the connection between the playback deck and the telephone line associated with that interface unit unless the telephone line is ringing the start of the prerecorded message. All the telephone lines which are ringing at the start of the prerecorded message are connected to the playback deck to hear the prerecorded message from the start and all the telephone lines which are not ringing at the start of the prerecorded message remain unconnected to the playback deck throughout the playing of the message irrespectively of whether they subsequently begin ringing.
An interface unit of the present invention selectively provides interconnection between a telephone line and an audio device such as a playback deck or the like. It includes a switch for setting the mode of operation of the unit, enabling circuitry responsive to the unit being in the first mode and to the presence of a ring signal on the telephone line for putting the unit in a waiting state, and first switching circuitry responsive to a first state of the audio device for making a connection between the telephone line and the audio device only when the unit is in the first mode and the waiting state. Additional circuitry independent of the first switching circuitry is provided for making a connection between the telephone line and the device in response to a ring signal when the unit is in a second mode. Second switching circuitry is responsive to an external signal for making a connection between the telephone line and the audio device only in response to the external signal, independently of the mode of the unit as set by the mode setting switch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan of an interface unit of the present invention;
FIG. 2 is a block diagram illustrating the operation of the interface unit of FIG. 1;
FIG. 3 is an electrical schematic of the circuitry of the interface unit of FIG. 1;
FIG. 4 is a block schematic illustrating a system of the present invention;
FIG. 5 is a schematic similar to FIG. 4 illustrating an alternative embodiment of the system of the present invention; and
FIG. 6 is a schematic similar to FIGS. 4 and 5 illustrating a third embodiment of the system of the present invention.
Similar reference characters indicate similar parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An interface unit 11 (FIG. 1) of the present invention is mounted in a relative small, hard ABS plastic housing 13 having dimensions of, for example and not by way of limitation, 5.75" by 3.6" by 1.62". An optional LCD counter display 15 is visible through a window 17 in the upper surface of housing 13. Immediately below counter display 15 as shown in FIG. 1 is a three-position switch 19 for setting the three modes of operation of the unit as described below. These modes are labelled "Remote", "Off", and "Auto" and these labels are suitably imprinted on the upper surface of housing 13 by an overlay or the like.
Unit 11 also includes a terminal strip 21 disposed at the front of the housing. This strip includes a first pair of terminals 23A and 23B by means of which the unit supplies a momentary switch closure signal to the external world signifying that the telephone line associated with that unit is ringing. This telephone line is connected to the interface unit by means of a standard RJllC modular jack 24 disposed below the terminal strip as shown in FIG. 1. A legend consisting of the word "Momentary" and a symbol for a transistor are imprinted above terminals 23A and 23B to visually indicate the function of these terminals to the user or operator of the unit.
The terminal strip also includes a second pair of terminals 25A and 25B which are used to allow a control signal from external equipment such as a playback deck 27 (see FIG. 4) or other audio device to control the interface unit. A green light-emitting diode (LED) 29 is disposed above these terminals to visually indicate to the user that external equipment has control of the interface unit. A legend imprinted above these terminals indicates the permissible voltages and currents for these terminals, namely 3-30 mA at 5-30 VDC.
To the right of terminals 25A and 25B in terminal strip 21 is a third pair of terminals 31A and 31B. These terminals in use are connected to the audio signal terminals of the external equipment such as a playback deck. Internally they are connected to one side of a 600 ohm audio transformer, and a legend indicating this fact appears above these terminals. The recommended input level for incoming audio feed is -8 decibels average. Interface unit 11 itself has very low impedance and is practically unseen when connected between a telephone line and the playback deck or other audio device. Immediately above terminals 31A and 31B is a red LED 33 which when lit indicates to the user that the telephone line is in use. A legend to this effect is imprinted on housing 13.
Terminal strip 21 also includes a fourth pair of terminals 35A and 35B which latch closed for the entire time the telephone line is connected to the external audio device. These terminals may be used, for example, to operate an external display in those cases where interface unit 11 is mounted in a closet or some other location where LED 33 is not readily visible. These terminals are rated at 0.5 A at 24 VDC and this information along with a legend consisting of the word "Latched" and a transistor symbol are imprinted on the surface of housing 13.
The general operation of interface unit 11 is schematically illustrated in FIG. 2. Operation is controlled by the status of the telephone line (either ringing or not), which is indicated by the words "Telco In" on FIG. 2, and optionally by a control signal from an external source such as the run circuit of playback deck 27. This optional control signal is indicated on FIG. 2 by the legend "Remote 24 VDC", although the control voltage may be at any conventional level such as 5 VDC, 24 VDC, or 30 VDC.
The ringing signal on the telephone line is supplied to a coupling capacitor C1 (FIG. 3) that allows only the ac component of the waveform on the telephone line to pass to the control portion of the circuitry of the interface unit 11. A ring signal on the telephone line is passed by the coupling capacitor to a ring detect circuit 37 which includes a capacitor C3 which stores the charge generated by a ring signal so that the circuitry of FIG. 3 is ready to operate just as soon as the external control signal is received from playback deck 27. Ring detect circuit 37 (FIG. 3) is under the control of mode selecting switch 19 (labelled "Remote-Auto Switch" in FIG. 2).
The mode selecting switch 19 directly affects the operation of ring detect circuit 37 and also controls the operation of a pair of opto-isolators (optos) 39 and 41 (FIG. 3) which have a control function. Optos 39 and 41, by way of example, may be those sold under the trade designation MCT 5211 by General Instruments. Assuming the circuitry of FIG. 3 is in the proper state, a Momentary opto 43 causes a momentary switch closure across terminals 23A and 23B. The circuitry of FIG. 3 also includes a latching SCR 45 which as indicated in FIG. 2 latches when the momentary switch closure occurs and opto 39 conducts. The telephone line signal is supplied directly to the anode of the latching SCR so that when the SCR is gated the telephone line may be connected through the latching SCR to the playback deck or other audio device. Assuming the conditions are proper for a connection to be made between the telephone line and the playback deck, a latching opto 47 is activated to cause latching terminals 35A and 35B to close and LED 33 to light, visually indicating that the line is in use.
The output of latching SCR 45 is supplied to an audio transformer 49 having one of its windings connected to terminals 31A and 31B. These terminals in turn are connected to the customer provided audio equipment such as playback deck 27, so that interconnection is completed between the telephone line and the audio equipment.
In more detail (see FIG. 3), the operation of interface unit 11 is as follows: Mode selecting switch 19 is a three-pole, three-position, center off switch. For purposes of illustration the center position of the switch for each of the poles is illustrated by a contact, although it should be realized that there is no electrical connection to that contact. Switch 19 is shown in FIG. 3 in the Auto mode position in which the switch arm of each pole contacts the upper contact associated with that pole. In this mode connection is made between the telephone line and the audio device automatically upon the ringing of the telephone line. The signal from the ringing telephone line is rectified by a diode bridge 53 and supplied through coupling capacitor C1, which is a 1 micro-F, 250 V capacitor, to the ring detect circuit 3. Capacitor C1 insures that only ac current from the telephone line is supplied to the bridge. Bridge 53 has a surge clamp 55, rated at 200 V, connected across its input terminals to protect the circuitry of FIG. 3 from excessive voltages on the telephone line.
The output of bridge 53 is supplied to ring detect circuit 37, and more particularly to a 470 micro-F, 50 V capacitor C3. This capacitor is in series with a 30 V, 1 W Zener diode D1 and a 27.4 K-ohm resistor R1. In the Auto mode, current from the bridge passes through the second pole 19B of mode selecting switch 19 in series with a 100 K-ohm resistor R3 to the gate of an SCR 57. The anode of SCR 57 is connected to capacitor C3, and in the Auto mode this SCR conducts when the telephone line rings.
SCR 57 is inhibited by opto 41 when that opto conducts, but it does not conduct in the Auto mode. The third pole of switch 19, pole 19C, controls whether opto 41 can conduct. In the Auto mode as shown in FIG. 3, an SCR 59 connected through a 910 ohm resistor R5 to terminal 25A is prevented from firing because of an open circuit in its gating circuit. This gating circuit consists of a 600 V, 1 A diode D5, a 27.4 K-ohm resistor R7, a 0.01 micro-F capacitor C5, and a 47.5 K-ohm resistor R9 connected as shown. In the Remote mode this gating circuit receives gating current from terminal 25A, but this is impossible in the Auto mode because of the position of the third pole of switch 19. Optos 39 and 41 conduct only when SCR 59 fires, so in the Auto mode, neither of these optos conduct. Thus, in the Auto mode opto 41 does not conduct and SCR 57 is allowed to fire when the telephone line rings.
A 0.01 micro-F capacitor C7 and a 10 K-ohm resistor R11 are connected across the cathode/gate junction of SCR 57 so that when the SCR fires it latches itself. The cathode of SCR 57 is connected through a 4.75 K-ohm resistor R13 to the anode terminal of opto 43, the Momentary opto. The cathode of SCR 57 is also connected through a 2 K-ohm resistor R15 to the anode control terminal of an opto-SCR 61. By way of example, opto-SCR may be one such as is sold under the trade designation MCS 2401 by General Instruments. Firing of SCR 57 causes opto 43 to conduct and opto-SCR 61 to fire. Opto 43 has a 0.01 micro-F capacitor C11 connected between its base and emitter terminals. The emitter and collector terminals of opto 43 are connected to a Darlington 63, which in turn is connected across Momentary terminals 23A and 23B. Conduction of opto 43 causes the temporary switch closure across terminals 23A and 23B mentioned above. A protective 1000 V diode D7 is also connected across these terminals as shown.
When opto-SCR 61 fires, it gates latching SCR 45 so that the signal from the telephone line may pass through SCR 45 and the first pole 19A of switch 19 directly to one terminal 62 of audio transformer 49. The other terminal of that particular winding of transformer 49 is connected through a 10 micro-F capacitor C12 to the negative side of the telephone line. A pair of terminals 67A and 67B are provided across the series circuit of the transformer winding and capacitor C12 to allow counter 15 to receive signals indicative of a connection being made between the telephone line and the audio transformer.
Opto-SCR 61 has a 0.1 micro-F capacitor C13 between its gate and cathode terminals. The cathode of this opto-SCR is also connected to the gate of SCR 45 while the anode of the opto-SCR is connected to the anode of SCR 45 through a 600 V diode D11 in series with a 4.75 K-ohm resistor R21. With this arrangement, once the telephone line rings to fire opto-SCR 61, current from the telephone line flows through diode D11, resistor R21, and the opto-SCR to gate latching SCR 45. A 1.21 K-ohm resistor R23 and a 0.1 micro-F capacitor C15 are connected across the cathode/gate junction of SCR 45, so that once SCR 45 fires it latches on.
When the connection is made between the telephone line and the audio transformer, current flows through a 681 ohm resistor R25 in series with LED 33 and through the anode/cathode circuit of latching opto 47 to cause the LED to light. Latching opto 47 has a 0.01 micro-F capacitor C19 connected between its base and emitter terminals and a Darlington 71 connected between its emitter and collector terminals. This Darlington provides the previously mentioned switch closure between latching terminals 35A and 35B. When LED 33 lights, opto 47 conducts, thereby closing the circuit between these terminals.
In the Remote mode of operation, interface unit is under external control. In this mode the switch arms of switch 19 contact the lowermost of the three contacts per pole shown in FIG. 3. Putting the first pole 19A in this position prevents the completion of the circuit just described in connection with the Auto mode between the telephone line, SCR 45, and the audio transformer 49. The new position of the second pole 19B makes no functional change in the circuit described above because the top and bottom contacts of the second pole are functionally equivalent.
Placing the third pole 19C in the Remote position allows the voltage levels across terminals 25A and 25B to control the operation of the interface unit. When the voltage of terminal 25A with respect to terminal 25B is positive, for example, 5 V, 24 V, or 30 V, gating current is supplied to SCR 59. Such a positive voltage is supplied, for example, from the run circuit of playback deck 27 while it is running. However, when the playback deck is recued (ready to replay its prerecorded message from the beginning) the control voltage drops to zero.
While the control voltage is positive, SCR 59 is gated and conducts. This causes current to flow through a 240 ohm resistor R31 in series with LED 29. LED 29 then lights, giving a visual indication to the user that the playback deck is in operation. The current from SCR 59 during this condition also causes optos 39 and 41 to conduct. The emitter terminal of opto 41 is connected to its base terminal by a 0.001 micro-F capacitor C21 and through a 7.5 K-ohm resistor R33 to the cathode terminals of opto 43 and opto-SCR 61. Conduction of opto 41 inhibits opto 43 and opto-SCR 61 while the playback deck is running by inhibiting firing of SCR 57. This feature insures that the telephone line connected to interface unit 11 cannot be connected to the playback deck while the playback deck is running.
However, once the playback deck is recued and ready to start the prerecorded message again, the voltage goes to zero. SCR 59 stops conducting and as a result opto 41 no longer inhibits the operation of opto 43 and opto-SCR 61 so long as the voltage from the playback deck remains zero. If at this time the telephone line associated with interface unit 11 is ringing, opto 43 and opto-SCR 61 conduct, closing the circuit between terminals 23A and 23B and causing latching SCR 45 to attempt to latch. Terminals 23A and 23B are preferably connected to playback deck 27 to provide a start signal to the deck. Thus, once the deck is recued and the telephone line rings, the playback deck immediately starts its message because of the signal across terminals 23A and 23B. Of course, if there were no cart in the playback deck for some reason (such as the replacement of one cart by another) the control voltage on terminals 23A and 23B would stay at zero volts and latch 45 would be prevented from latching on until a cart was replaced in the playback deck.
As the playback deck begins running again, the control voltage across terminals 25A and 25B goes positive again, which inhibits further conduction by opto 43 or opto-SCR 61. However, this positive voltage also causes opto 39 to conduct. A 0.022 micro-F capacitor C25 is connected across the base and emitter terminals of opto 39 and an NPN transistor Qll has its collector/base junction connected across the collector and emitter of opto 39. When opto 39 conducts, this transistor conducts as well, causing latching SCR 45 to latch on. The cathode of SCR 45 is connected to the collector of transistor Qll and the emitter of the transistor is connected to terminal 62 of the audio transformer. When transistor Q11 causes SCR 45 to latch, this completes a circuit from the telephone line through SCR 45 and transistor Q11 to the audio transformer.
The inhibit feature described above is of special use when the playback deck is connected to a number of interface units 11 (see FIGS. 4 and 6). In this case, opto 41 inhibits all the interface units that were not connected to a ringing telephone line at the time the playback deck started from connecting their telephone lines to the playback deck. Those lines which begin ringing later simply continue to ring until the playback deck is recued and starts the message again from the beginning. Conversely, all those lines which are ringing when the inhibit signal is momentarily removed are connected by their interface units to the playback deck simultaneously at the start of the message.
The circuitry of FIG. 3 also includes an opto-SCR 77 and an SCR 79 which enable the interface unit to be used for remote audio feeds irrespective of the mode of the interface unit as set by switch 19 (this application is illustrated in FIG. 5). The cathode of SCR 79 is directly connected to terminal 62 of the audio transformer and through a 475 ohm resistor R41 to the negative side of the telephone line. The positive side of the the telephone line is directly connected to the anode of SCR 79. Thus, when SCR 79 is gated on it directly connects the telephone line to the audio transformer.
A 1.21 K-ohm resistor R43 and 0.1 micro-F capacitor C31 are connected across the cathode/gate junction of SCR 79. The gating current for this SCR is supplied from opto-SCR 77. When a reverse polarity voltage is applied to terminals 25A and 25B (terminal 25B positive with respect to terminal 25A), a circuit including the anode/cathode control terminals of opto-SCR 77, a 600 V diode D21, and a 200 ohm resistor R45 is completed which causes the opto-SCR to conduct. A 0.1 micro-F capacitor C33 is connected across the cathode/gate junction of the opto-SCR, while the anode of the opto-SCR is connected through a 600 V diode D23 and a 4.75 K-ohm resistor R47 to the anode of SCR 79. When the reverse polarity signal is supplied to control terminals 25A and 25B, therefore, a circuit is completed through SCR 79 between the telephone line and the audio transformer.
When the caller on the telephone line hangs up, the signal at 24 either reverses polarity or an open circuit appears across 24 as seen by the circuitry of FIG. 3. In either event, latching SCR 45 or SCR 79, depending upon the particular way in which the interface unit is being used, ceases to conduct and the connection between the telephone line and the audio transformer is broken by the interface unit. This feature is important when the interface unit is being controlled by the playback deck. In that situation, the connection between the telephone line and the playback deck cannot be reestablished until the playback deck has recued because opto 41 inhibits the firing of latching SCR 45 once it ceases conduction. That is, if one caller hangs up in the middle of the prerecorded message, interface unit 11 frees up that particular line immediately so that another caller may call in, but it will not connect that new caller to the message until the playback deck has recued. This ensures that each caller always hears the message from the beginning.
The third mode of operation, the Off mode is useful when the operator wants to change the message playing on the playback deck. This mode allows any line connected to the playback deck to remain connected until the message finishes (assuming the unit was previously in the Remote mode), but prevents any further telephone lines from being connected to the deck until the mode selecting switches for those lines are moved from the Off mode position. For example, assume that an interface unit already has connected its telephone line to the playback deck at the time the operator puts that unit in the Off mode. This action causes no change in the operation of the circuit so long as the caller remains on the telephone line. However, a new caller cannot get through because pole 19B has disabled the ring detect circuitry 37 in this mode. The operator places all the interface units in the Off mode and when all the LEDs 33 go out, indicating that all the connections are broken, he replaces the previous message in the playback deck with a new message. The operator may then place as many of the interface units as desired back in the proper mode (e.g., the Remote mode) and operation of the interface units resumes as described above.
It should be appreciated from the above that interface unit 11 is extremely flexible. Just a few of the possible system applications of this unit are schematically illustrated in FIG. 4 through 6. In FIG. 4, five interface units 11, each connected to its own telephone line TELCO, are connected to a single playback deck 27. When the playback deck is recued, all the interface units with telephone lines which are ringing at that time are simultaneously connected to the playback deck and the prerecorded message on the deck starts from the beginning. All interface units without a ringing telephone line when the playback deck is restarted are inhibited from connecting their telephone lines to the playback deck until the deck is recued. Although five interface units are shown in FIG. 4, it should be appreciated that a practically unlimited number of such units could be used with a single playback deck with suitable auxiliary power switching and amplified impedance matching circuitry.
Another application of interface units 11 is that of remote audio feeds as described above. Ordinary telephone lines have a limited frequency range which makes their audio generally unsuitable for high quality radio broadcasting. Devices are available which compress the frequency of the audio feed to provide the desired fidelity at the radio station, but these systems require the two telephone lines labelled TELCO in FIG. 5. Each line is suitably connected to its own interface unit 11 of the present invention and the audio transformer outputs of each unit 11 are supplied to a conventional frequency extender 81 to reconstruct the original audio signal. This reconstructed signal is then supplied in the conventional manner to the studio 83 for broadcast. Equipment such as frequency extender 81 is usually hidden in a closet or a rack which prevents the "on-line" indicators 33 of units 11 from being seen. However, latching terminals 35A and 35B of each of the interface units provide the switching needed for an external indicator lamp (not shown) for giving an immediate visual check in the studio on line status.
Another system using interface units 11 is shown in FIG. 6. In this system the telephone lines are connected to playback deck 27 as controlled by the playback deck or, at the operator's option, by operator control in the studio. This control could be exercised by a single studio control switch 85 for supplying the reverse polarity signal described above to terminals 25A and 25B.
In view of the above, it will be seen that the various objects and features of the present invention are achieved and other advantageous results attained.
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 and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A multiline telephone answering system includes a playback deck for supplying a prerecorded message and a plurality of interface units for interconnecting a plurality of telephone lines and the playback deck. Each interface unit is associated with a particular telephone line and supplies a start signal to the playback deck when its associated line is ringing. Each interface unit is responsive to the state of the playback deck for connecting its line to the playback deck only at the start of the prerecorded message and inhibits the connection between the playback deck and its telephone line unless that telephone line is ringing at the start of the prerecorded message. All telephone lines which are ringing at the start of the prerecorded message are connected to the playback deck to hear the prerecorded message from the start and all the telephone lines which are not ringing at the start of the prerecorded message remain unconnected to the playback deck throughout the playing of the message irrespective of whether they subsequently begin ringing. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluorescent tube holder for a fluorescent tube base mounting apparatus used in the manufacture of fluorescent lamps, and more particularly, to the fluorescent tube holder used for securely holding and transporting the fluorescent tube and the bases therefor with the leads emerging from ends of the fluorescent tube inserted into the base pins in the fluorescent tube base mounting apparatus.
2. Description of the Prior Art
In the conventional manufacture of fluorescent lamps, in order that the fluorescent tube and the bases therefor are adhered together in subsequent steps, it was the general practice in a base mounting apparatus to insert leads for the filament coil emerging from an end of the fluorescent tube together with base pins into the bases which are supported at the ends of the fluorescent tube during the intermediate steps in which the fluorescent tubes were held and transported by a number of fluorescent tube holders provided at equal distances in the conveyor chains. However, since the leads themselves were weak and there was no particular means provided to hold the bases securely, the conventional base mounting apparatus had a serious disadvantage that the bases supported in this manner easily separated or fell apart from the fluorescent tube in the course of transportation, thereby making it impossible to mount the bases reliably and securely at high speed.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to overcome the disadvantage of a reduction in efficiency of the base adhering operation caused heretofore by accidental falling off of the base from the fluorescent tube, by providing a fluorescent tube holder capable of reliably and securely supporting the fluorescent tube and bases therefor with the base pins thereof inserted through leads in the fluorescent tube base mounting apparatus.
The fluorescent tube holder according to the present invention is characterized in that it comprises a fluorescent tube holding chuck having a pair of releasable claws for holding the fluorescent tube, and a base chuck having a pair of releasable claws for holding the base of the fluorescent tube on the outer periphery thereof, in which the base chuck is movable toward and away from an end of the fluorescent tube held by the fluorescent tube holding chuck.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a plan view of fluorescent tube holders according to the present invention, showing the holders used in only one end of each of the fluorescent tubes;
FIG. 2 is a sectional side elevation of the fluorescent tube holder of FIG. 1;
FIG. 3 is an end view taken along line III--III of FIG. 2; and
FIG. 4 is a side elevation taken along line IV--IV of FIG. 1, showing a detent mechanism for fittingly stopping the fluorescent tube base chuck sideways.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the fluorescent tube holder according to the present invention will now be described in detail with reference to the drawings.
In FIG. 1 there are illustrated fluorescent tube holders according to the present invention. While the holders are provided symmetrically on both ends of the fluorescent tube, the holders on one end only of the fluorescent tube are shown in FIG. 1 for the sake of simplification. In the drawings, reference numeral 1 generally denotes each of a plurality of fluorescent tube holders according to the embodiment of the present invention, which comprises a fluorescent tube chuck 2 and a base chuck 4, both being held by a pair of longitudinally extending shafts 12 and 13 connected at both ends thereof in parallel to each other by links 11. Successive pairs of shafts 12 and 13 of successive holders are connected through links 14 to adjacent shafts 15 successively into an endless chain which extends in a closed path, perpendicular to the longitudinal extent of shafts 12, 13 and 15. The shafts 12, 13 and 15 are respectively provided at both ends thereof with rollers 16, 17 and 18 for chain gears. The linked shafts 12, 13 and 15 may be advanced by suitable means in the closed path.
As shown in FIGS. 1, 2 and 3, the fluorescent tube chuck 2 has a pair of arms 21 and 22 mounted pivotally on the shafts 12 and 13, respectively, through sleeves 25 and 26, respectively. The arms 21 and 22 are provided at upper ends thereof with claws 211 and 221, respectively, secured by set screws 212 and 222, respectively.
The arms 21 and 22 are urged toward each other by a spring 23 at their tip ends (upper ends in FIG. 2) so as to cooperate to hold a fluorescent tube V. Arms 21 and 22 are respectively secured to the sleeves 25 and 26, on which inter-meshing gears 250 and 260, are respectively formed concentrically with the respective shafts 12 and 13. These arms 21 and 22 are prevented from axial movement by a connector member 24 fixed to the shafts 12 and 13, but are pivotable about the shafts. When a projection 210 formed at a rear end (lower end) of the arm 21 is pushed by an external actuating means (not shown), the arms 21 and 22 are simultaneously moved apart (through the gears) to hold or release the fluorescent tube.
The base chuck 4 comprises sleeves 41 and 42 mounted rotatably and axially (longitudinally) movably on the shafts 12 and 13, respectively, arms 43 and 44 fixed at ends (rightward ends in FIG. 2) of the sleeves 41 and 42, respectively, claws 47 and 48 fixed at forward ends (upper ends in FIG. 2) of the arms 43 and 44, respectively, through axially extending rods 45 and 46, respectively, and a connector plate 50 on which the sleeves 41 and 42 are mounted. The claws 47 and 48 may be formed integrally with the arms 43 and 44, respectively.
The sleeves 41 and 42 are respectively formed with inter-meshing gears 410 and 420.
The arms 43 and 44 are urged toward each other by a spring 49 at the tip ends thereof so that the claws 47 and 48 can cooperate with each other to hold a base F. As is illustrated in FIG. 3, arm 43 has a projection 430 formed (in the same form as the projection 210 of the arm 21) at the lower end thereof. By urging the projection 430 in the direction X by means of an external means (not shown), the claws 47 and 48 may be opened apart in the directions Y and Z, respectively, so as to hold or release the base F.
Mounted rotatably on the underside of the connector plate 50 is a roller 51 which is received in a groove 520 of a cam plate 52 provided along the direction of advancement of the fluorescent tube holder which extends along the closed path of the endless chain of shafts 12, 13 and 15. Groove 520 curves back and forth between longitudinal positions A and B along the direction of advancement of the tube holder so that roller 51 rolls in the groove 520 causes the entire base chuck 4 to slide on the shafts 12 and 13 between positions A and B.
On the connector member 24 and the connector plate 50 is provided a detent mechanism 60 for holding the base chuck at a base mounting position (shown in FIG. 2). As shown in FIG. 4, the detent mechanism 60 comprises a shaft 61 projecting from the connector member 24 securely into the connector plate 50 between the shafts 12 and 13, a cavity 62 formed in the connector plate 50 for receiving the shaft 61, a sleeve 63 mounted on the connector plate 50, and a ball 64 inserted into the sleeve 63 and urged toward the cavity 62 by the spring 65. When the base chuck is in the mounting position and the shaft 61 enters the cavity 62, the ball engages with a peripheral groove 66 on the shaft 61 to prevent the axial movement of the base chuck.
The operation of the fluorescent tube holder having the construction described above will now be explained. A fluorescent tube V is held and transported by the fluorescent tube chuck 2 in a horizontal longitudinally extending orientation (parallel to shafts 12, 13 and 15), with a pair of leads L extending from an end thereof and directed horizontally as required. The claws 47 and 48 of the base chuck 4 have been advanced to the position shown by broken lines in FIG. 2 by moving the roller 51 to the position B. The base chuck 4 at this advanced position is opened apart by pushing the projection 430 upward to hold the base F prepared by known means, during which operation the leads L are inserted into a base pin P, and during the continued movement of the fluorescent tube holder 1 the roller 51 is returned to the position A and the base F is mounted to the end of the fluorescent tube V. Since the base chuck 4 is held at the mounting position by the detent mechanism 60 described hereinabove, the base F hereafter stays fitted into the end of the fluorescent tube. Furthermore, operation of the roller 51 is no longer necessary. The base thus combined is welded in the subsequent steps.
As will be apparent from the foregoing description, the fluorescent tube holder according to the present invention provides important advantages such as reliable and efficient mounting of the bases and efficient and speedier adhering in the succeeding step because the unsteady holding of the bases to the fluorescent tubes through leads in the conventional apparatus is eliminated in the apparatus according to the present invention.
While we have shown and described specific embodiment of our invention, it will be understood that these embodiments are merely for the purpose of illustration and description and that various other forms may be devised within the scope of our invention, as defined in the appended claims. | A fluorescent tube holder comprises a fluorescent tube holding chuck having a pair of releasable claws for holding the fluorescent tube, and a base chuck having a pair of releasable claws for holding the base of the fluorescent tube on the outer periphery thereof. The base chuck is movable toward and away from an end of the fluorescent tube held by said fluorescent tube holding chuck. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of Japanese Application No.2004-243166 filed Aug. 24, 2004, the contents of which are incorporated by this reference.
[0002] This application is a continuation of PCT application No. PCT/JP2005/010722, which was filed on Jun. 10, 2005.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a system for managing electronic data handled inside a hospital, and more particularly relates to how to transfer electronic data when transferring the data to outside the hospital.
[0005] 2. Description of the Related Art
[0006] Currently in a medical field too, with the development of a network technology and an information processing technology, a system for digitalizing information used inside a hospital facility, such as information about various types of medical actions, accounting information and the like, and exchanging this via a network is devised and put into practical use.
[0007] For example, Patent reference 1 (Japanese Patent Application No.2002-207822 (FIG. 1, paragraphs [0010]˜[0014]) discloses a system for exchanging medical information and the like by connecting an area information server provided for each area to a general home and a terminal provided for a medical facility in that area via a network or connecting each area information server and a comprehensive information server for exchanging data via a network, such as the Internet or the like.
[0008] Inside a hospital, with the advance of medical information connection system, such as a hospital information system (HIS) and the like, various data of a patient and its medical actions transmitted from examination equipment or a terminal device via a network is stored in/managed by an in-hospital server provided for each hospital.
[0009] It is considered that various types of information stored in/managed by the server in this hospital is used not only inside the hospital but also secondarily used outside the hospital. However, in this case, the rare data stored in the database of the in-hospital server is transferred to outside the hospital by copying it to a server outside the hospital. Alternatively, a service application outside the hospital directly obtains data field s to be secondarily used from the in-hospital server and uses them.
[0010] FIG. 1 shows how to conventionally transfer data to outside the hospital.
[0011] In FIG. 1A , each service application 102 for providing services using data stored in an in-hospital server 101 subsequently reads data from the in-hospital server individually. In FIG. 1B , an external server collectively sucks up data stored in the in-hospital server.
[0012] In the case of FIG. 1A , each of service applications 102 - 1 ˜ 102 -n individually accesses the in-hospital server 101 via a network and reads out necessary data.
[0013] In the case of FIG. 1B , an external server 103 sucks up all pieces of data stored in the in-hospital server 101 via a network and each of the service applications 102 - 1 ˜ 102 -n reads out necessary data from this external server 103 and secondarily uses it.
[0014] FIG. 2 is a flowchart showing the process of transfer data as shown in FIG. 1A .
[0015] FIG. 2A shows the process shown in FIG. 1A . In FIG. 2A when the process is started, firstly in step S 101 , information about examination is transmitted from each piece of examination equipment in the hospital to the in-hospital server 101 . Then, in step S 102 , the in-hospital server 101 registers and stores this information in an internal database.
[0016] In this state, in step S 103 , each service application 102 for secondarily using data in the in-hospital server 101 accesses the in-hospital server 101 via a network to obtain only necessary information from the in-hospital server 101 (step S 104 ). Then, each service application 102 uses this information to realize services (step S 105 ).
[0017] FIG. 2B shows the process shown in FIG. 1B . In FIG. 2B when the process is started, as in FIG. 2A , firstly in step S 111 , information about examination is transmitted from each piece of examination equipment to the in-hospital server 101 . Then, in step S 112 , the in-hospital server 101 registers and stores this information in an internal database as in-hospital information.
[0018] In this state, in step S 113 , the external server 103 accesses the in-hospital server 101 via the network to suck up and obtain all pieces of in-hospital information stored in the database and stored/accumulated in the in-hospital server 101 .
[0019] Then, in step S 113 , each service application 102 for secondarily using data in the in-hospital server 101 accesses the external server 103 via the network to obtain only necessary in-hospital information from the external server 103 (step S 114 ). Then, each service application 102 uses this information to realize services (step S 115 ).
[0020] As described above, when using in-hospital information outside the hospital, conventionally each service application 102 directly obtains and uses information collected in the in-hospital server 101 (method 1). Alternatively, the external server 103 sucks up all pieces of information in the in-hospital server 101 and service application 102 uses only necessary (method 2).
[0021] In method 1, since necessary information can be obtained on demand by an out-hospital server accessing an in-hospital server, necessary information can be obtained and processed for each service application. However, in this case, the more the number of service applications becomes, the more the number of accesses to the in-hospital server becomes. Therefore, it becomes more difficult to protect security and load to the in-hospital server becomes larger. Furthermore, when a plurality of service application must be generated, a mechanism for obtaining information from the in-hospital server must be provided for each service application and the in-hospital server. Therefore, it takes much time and labor to extend the entire system including the in-hospital server, out-hospital server or service applications. In method 2, since all pieces of information in the in-hospital server is sucked up, information which a hospital does not want to go out of the hospital and information which a law/regulation prohibits from going out of the hospital is also sucked up. Furthermore, since all pieces of information in the in-hospital server are sucked up, the transfer amount of data increases to give a large load to the out-hospital and in-hospital servers.
Patent reference 1: Japanese Patent Application No. 2002-207822 (FIG. 1, paragraphs [0010]˜[0014]) Patent reference 2: Re-published WO02/017171 (pages 14˜25, FIGS. 1˜9)
SUMMARY OF THE INVENTION
[0024] Therefore, it is an object of the present invention to provide a data management system with a mechanism for efficiently sucking up necessary information from an in-hospital server in order to provide each service.
[0025] It is another object of the present invention to provide a data management system for efficiently sucking up necessary information from an in-hospital server in order to provide each service while preventing information which a hospital does not want to go out of the hospital from the in-hospital server, such as personal information and the like, or information which a law/regulation prohibits from going out of the hospital, from leaking from the in-hospital server.
[0026] Furthermore, it is another object of the present invention to provide a highly extendable data management system capable of minimizing the number of modification points even when the number of services increases to increase the number of service applications for providing the services.
[0027] An in-hospital information processing device for storing and managing in-hospital information handled in a hospital comprises an in-hospital information storage means (or in-hospital information storage unit), a mask means (or mask setting unit) and a publishable information generation means (or publishable information generation unit) in order to solve the above-described problems.
[0028] The in-hospital information storage means stores and accumulates in-hospital information collected from within the hospital.
[0029] The mask setting means sets mask information indicating whether the in-hospital information stored in the in-hospital information storage means should be permitted to provide to outside the hospital.
[0030] The publishable information generation means generates only publishable information which is permitted to provide or output to outside the hospital via a communication line, based on the mask information.
[0031] An out-hospital information processing device installed outside a hospital comprises a publishable information reading means (or publishable information reading unit) and a publishable information storage means (or publishable information storage unit).
[0032] The publishable information reading means reads out the publishable information from the in-hospital server.
[0033] The publishable information storage means stores the publishable information read out from the in-hospital server.
[0034] By adopting such configurations, an external server can read out only publishable information excluding in-hospital information whose provision to outside the hospital is prohibited. Therefore, in-hospital information whose provision to outside the hospital is prohibited can be prevented from being read by an external server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1A shows how to conventionally transfer data to outside a hospital (No. 1 );
[0036] FIG. 1B shows how to conventionally transfer data to outside a hospital (No. 2 );
[0037] FIG. 2A is a flowchart showing the conventional process of transferring data (No. 1 );
[0038] FIG. 2B is a flowchart showing the conventional process of transferring data (No. 2 );
[0039] FIG. 3 shows how to transfer in-hospital information to outside the hospital in the data management system of the preferred embodiment;
[0040] FIG. 4 shows the basic configuration of all components installed inside the hospital, of the data management system in the preferred embodiment;
[0041] FIG. 5 shows the configuration of a system provided for a diagnosis and treatment department;
[0042] FIG. 6 shows the configuration of the in-hospital server;
[0043] FIG. 7 shows the basic configuration of the entire data management system in the preferred embodiment and its flow of information;
[0044] FIG. 8 shows the process flow in the hospital at the time of endoscopic examination and its major generated in-hospital information;
[0045] FIG. 9 is a flowchart showing the operational process of the in-hospital server at the time of mask information setting;
[0046] FIG. 10 shows an example of a mask information setting screen;
[0047] FIG. 11 shows an example of in-hospital information stored in the in-hospital server;
[0048] FIG. 12 shows an example of a definition sentence by a SQL code, for generating publishable in-hospital information View;
[0049] FIG. 13 is a flowchart showing the process of the external server, performed when sucking up information from the in-hospital server of a hospital;
[0050] FIG. 14 shows an example of a hospital selection screen;
[0051] FIG. 15A shows an example of publishable in-hospital information sucked up from a hospital by an external server;
[0052] FIG. 15B shows another example of publishable in-hospital information sucked up from a hospital by the external server (No. 1 );
[0053] FIG. 15C shows another example of publishable in-hospital information sucked up from a hospital by an external server (No. 2 );
[0054] FIG. 15D shows another example of publishable in-hospital information sucked up from a hospital by an external server (No. 3 );
[0055] FIG. 15E shows another example of publishable in-hospital information sucked up from a hospital by an external server (No. 4 );
[0056] FIG. 16 is a flowchart showing the process of the service application;
[0057] FIG. 17 shows the typical data management system of other preferred embodiments;
[0058] FIG. 18 shows the data management system of another preferred embodiment;
[0059] FIG. 19 is a flowchart showing the operation of a terminal;
[0060] FIG. 20 shows an example of a mask setting GUI screen displayed on the monitor of the terminal;
[0061] FIG. 21 shows an example of a mask table recorded on the terminal;
[0062] FIG. 22 is a flowchart showing a series of operations from the mask table transmitting operation of the terminal up to the mask table recording operation of an information registration server;
[0063] FIG. 23 shows an example of a mask table whose mask information is already modified;
[0064] FIG. 24 shows another example of a mask table whose mask information is already modified;
[0065] FIG. 25 shows an example of a database provided for a database management terminal;
[0066] FIG. 26 is a flowchart showing the data management system in the case where in-hospital information corresponding to the modified mask information is deleted from the database of the database management terminal;
[0067] FIG. 27 shows an example of the mask table in the case where old and new mask tables are combined;
[0068] FIG. 28 shows the database in the case where all examination contents areas corresponding to the modified mask information is nullified;
[0069] FIG. 29 is a flowchart showing the operation of additionally recording in-hospital information corresponding to the modified mask information on the database;
[0070] FIG. 30 shows an example of the mask table obtained by combining old and new mask tables;
[0071] FIG. 31 shows the data table of in-hospital information extracted from the database of an information storage server;
[0072] FIG. 32 shows how to additionally record lacking in-hospital information on the database;
[0073] FIG. 33 shows the configuration of another preferred embodiment of the data management system;
[0074] FIG. 34 is a flowchart showing the operation of a terminal;
[0075] FIG. 35 is a flowchart showing the operation of the data management system, of additionally recording in-hospital information on the database;
[0076] FIG. 36 is a flowchart showing the operation of the data management system, of deleting in-hospital information from the database;
[0077] FIG. 37 is a flowchart showing the operation of the data management system, of additionally recording in-hospital information on the database; and
[0078] FIG. 38 is a flowchart showing the operation of the data management system, of deleting in-hospital information from the database.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0079] One preferred embodiment of the present invention is described below with reference to the drawings.
[0080] FIG. 3 shows how to transfer in-hospital information to outside the hospital in the data management system of this preferred embodiment.
[0081] In this preferred embodiment, various types of information is collected from each diagnosis and treatment department and a reception in a hospital via an intra-hospital LAN installed in the hospital, and is stored in the database and stored in an in-hospital server (also called “in-hospital information processing device”) 1 . Then, the manager sets and inputs mask information for instructing the provision prohibition of information whose provision to outside the hospital is prohibited, such as information to be related to the privacy of a patient, of the various types of collected information. Then, information which is permitted to provide is generated based on this mask information, and an external server (also called “out-hospital information processing device”) 3 located outside the hospital sucks up only the information via a communication line (for example, a public network, such as the Internet or the like). Then, each of service applications 2 - 1 ˜ 2 -n generated for each service provides services by reading out its necessary information from the in-hospital information stored in the external server 3 , whose provision to outside the hospital is permitted, and using it.
[0082] Thus, information whose provision to outside the hospital is not desired, such as the personal information of patients and the like can be preventing from externally leaking. Since each of the service applications 2 - 1 ˜ 2 -n reads out necessary information not from the in-hospital server but from the external server 2 , the restriction of data transfer speed is loose. Furthermore, when a new external service application 2 must be generated, by extracting in advance information excluding one whose provision to outside the hospital is prohibited, from the data of the in-hospital server 1 to the external server 3 and a service application 2 for secondarily using the data using it, redundancy can be eliminated and extensibility can be provided.
[0083] In this specification, a term “in-hospital server” includes all servers for collecting, storing and managing electronic data inside a hospital, such as a server for storing and managing information handled inside the entire hospital facility, a server provided for each diagnosis and treatment department and other departments of the hospital and the like.
[0084] FIG. 4 shows the basic configuration of all components installed inside the hospital, of the data management system in the preferred embodiment.
[0085] In a data management system (also called “in-hospital system”) 10 , a plurality of terminals 12 , 14 and 16 are connected to each other by a LAN 13 .
[0086] The terminal 12 is used to refer to data stored in the data management system 10 . In FIG. 4 , portions enclosed by dotted lines 15 , 17 and 19 indicate department systems provided for each diagnosis and treatment department in a hospital, and the terminals 14 and 16 indicate ones belonging to each diagnosis and treatment department. For example, in a diagnosis and treatment department 15 , when inspecting using an endoscope, the terminal 14 is used to prepare an examination report by displaying the sensed image of the endoscope, inputting the opinion of a doctor, and so on. In a diagnosis and treatment department 17 , the terminal 16 is provided to prepare an examination report by displaying an image obtained in an examination and inputting the opinion of a doctor. The terminals 14 and 16 can also be medical equipment connected to a network.
[0087] FIG. 5 shows the configuration of a system provided for a diagnosis and treatment department. FIG. 5 corresponds to the diagnosis and treatment department 15 shown in FIG. 4 .
[0088] In FIG. 5 , to a LAN 23 , which is a part of the LAN 13 shown in FIG. 4 , an examination device terminal 22 , a report input/output terminal 24 , a data transmitting/receiving terminal 28 and a printer 29 are connected, and data can be exchanged among them via the LAN 23 .
[0089] The examination device terminal 22 is an information processing terminal for controlling an examination instrument and processing data, such as an examination result and the like. In FIG. 5 , an endoscopic examination device 21 is shown as an example of the examination instrument handled by the examination device terminal 22 . The image data of an image sensed by the endoscopic examination device 21 is taken into the examination device terminal 22 . The examination device terminal 22 also specifies the type of the endoscopic examination device 21 and so on.
[0090] The report input/output terminal 24 is used for a doctor conducting an examination to prepare a report by input its opinion and so on. A report prepared on this report input/output terminal 24 is transmitted to an in-hospital server 25 and a DVD control terminal 27 . The report prepared by the report input/output terminal 24 can be printed by the printer 29 b connected to this.
[0091] The in-hospital server 25 classifies data, such as patient information, including the name and age, of a patient, examination information, including image data obtained by an examination and a report describing the opinion of a doctor, equipment information, including the type and used time of a used examination instrument, user information, which is information about hospital staff, including a doctor and a nurse and the like, and stored the data in the database. These pieces of information collected via the LAN 23 are stored in the database as in-hospital information and is stored. The in-hospital server 25 also prints the information using the printer 29 a , based on a user's instruction. The DVD control terminal 27 stores image data obtained by an examination in a DVD mounted on a DVD changer 26 and reads out image data stored in the DVD.
[0092] The data transmitting/receiving terminal 28 receives the data of a patient from an electronic carte system 18 and accesses the data of another diagnosis and treatment department. The printer 29 is generally used to print data received by the data transmitting/receiving terminal 28 and to print data for a general purpose.
[0093] FIG. 6 shows the configuration of the in-hospital server 25 shown in FIG. 5 .
[0094] For the in-hospital server 25 , an ordinary general-purpose computer can be used. For example, its configuration is as shown in FIG. 6 .
[0095] In the configuration shown in FIG. 6 , a data control unit 36 , which can be realized by a CPU or the like, processes data, based on a program stored in a data storage unit, and realizes a process described later by storing data in the data storage unit 35 as requested and reading out data from the data storage unit 35 . To a data input unit 32 , an input device for a user inputting an instruction, such as a pointing device, including a mouse, a keyboard or the like is connected. By operating this input device, a doctor inputs information, such bas its opinion and the like. A data display unit 34 is connected to a PC monitor and transmits data for displaying an information setting/input screen, which is described later, on the PC monitor, to the PC monitor. A network I/F 31 is an interface for exchanging data with another device via the intra-hospital LAN. To a printer I/F 33 , a printer is connected, and prints and outputs in-hospital information stored in an external server and the like.
[0096] FIG. 7 shows the basic configuration of the entire data management system in the preferred embodiment and its flow of information.
[0097] In FIG. 7 , a service center for providing the management service of equipment used for examination, using in-hospital information handled in a hospital sucks up in-hospital information composed of character data, image data and the like, from the hospital, and provides services, such as the maintenance management of an examination instrument, charging and the like, using this in-hospital information.
[0098] A variety of information generated in equipment 43 - 1 ˜ 43 -m, such as an examination instrument, its terminals (corresponding to the endoscopic examination device 21 and examination device terminal 22 shown in FIG. 5 ) and one or a plurality of terminal devices 42 (corresponding to the terminals 12 , 14 and 16 shown in FIG. 4 ), which are connected to an intra-hospital LAN 41 , which is a network inside a hospital facility 40 is transmitted to an in-hospital server 45 (corresponding to the in-hospital server 25 shown in FIG. 5 ) via the intra-hospital LAN 41 (corresponding to the LAN 13 shown in FIG. 4 ) as shown by a route Rl and is stored/accumulated in the in-hospital server 45 .
[0099] When the read request of data stored in the in-hospital server 45 is issued from an external server 55 in an external facility 50 , such as a service center located outside the hospital facility 40 , to the in-hospital 45 via a route R 2 (or R 3 ), only information whose provision to outside the hospital the hospital side permits is sucked up by and stored in the external server 55 via a route R 4 (or R 5 ), which is the route the reversal of the route R 2 (or R 3 ).
[0100] The information stored in the external server 55 is obtained by service applications 56 - 1 ˜ 56 -n via an intra-house LAN 51 as shown in a route R 6 , upon the request of a service application used for each service, and is secondarily used in various ways.
[0101] On the route R 2 (or R 4 ) of the information routes shown in FIG. 7 , information is exchanged via a network 61 of the Internet. On the route R 2 , the external server 55 in the external facility 50 and the in-hospital server 45 in the hospital facility 40 are connected to the network 61 via a virtual private network (VPN) 44 (VPN 53 ) and a firewall 47 (firewall 52 ) to improve the security of data communication. On the route R 3 (and R 5 ), information is exchanged via a network 62 using a public line, such as a telephone line or the like. On the route R 3 (and R 5 ), the external server 55 in the external facility 50 and the in-hospital server 45 in the hospital facility 40 are connected to each other via the network 62 , using a dial-up router 46 (dial-up router 54 ).
[0102] Although in FIG. 7 , the external facility 50 , being a service center, is connected to one hospital facility 40 , the external facility 50 can also be connected to a plurality of hospital facilities 40 via the networks 61 and 62 , and can provide services by sucking up in-hospital information from the plurality of these hospital facilities 40 . In this case, by targeting a plurality of hospitals, wider services can be provided using in-hospital information collected from the plurality of hospitals.
[0103] Although service applications 56 - 1 ˜ 56 -n are provided in the same external facility 50 as the external server 55 , a part or all of these service applications 56 - 1 ˜ 56 -n can also be provided in a facility different the external facility 50 in which the external server 55 is installed and necessary in-hospital information can be read from the external server 55 via a dedicated line or the networks 61 and 62 .
[0104] In such a system configuration, for example, in the case of an endoscopic examination, an endoscopic examination device for conducting an endoscopic examination transmits equipment use information, examination information, examination result information, sensed image information and the like from the endoscopic examination device terminal 43 to the in-hospital server. When cleaning an endoscope after examination, cleaning information is transmitted from an endoscope cleaning device to the in-hospital server.
[0105] The in-hospital server 45 records and manages equipment/facility information, such as the number of endoscopic examination rooms, the number of endoscopic examination devices, the number of endoscopes, the number of endoscope cleaning devices as in-hospital information in addition to information about patients and examination transmitted from each piece of equipment 43 and each terminal from time to time. Then, by the mask setting process described later, the manager of the in-hospital server inputs mask information indicating whether the provision to outside the hospital of the information should be permitted, and the external server 55 sucks up only information whose provision to outside the hospital is permitted according to this mask information. In this case, such information can also be outputted to the external server 55 .
[0106] Then, in the external facility, the service application 56 realizes services using the information sucked up by the external server 55 .
[0107] As such services, a consultant service of calculating by how many endoscopes and endoscope cleaning machines an examination can be efficiently conducted in this hospital, based on the number of endoscopic examinations, an examination time, the number of doctors and nurses, the number of examination rooms, the number of endoscopes, the number of endoscope cleaning machines, etc., of information stored in the external server 55 , giving advices about the efficient use of equipment and giving consultations on the installation/introduction of endoscopic examination related facilities when installing a new hospital and when introducing such facilities, an equipment lease charging service of charging for the use of the device, based on the number of endoscopic examinations, the use of a special function of the endoscopic device, the used frequency of an endoscope, etc., and the like can be considered.
[0108] Next, the flow of each of various types of information in the data management system of this preferred embodiment is described in detail using various types of information generated by an endoscopic examination as an example.
[0109] FIG. 8 shows the process flow in the hospital at the time of endoscopic examination and its major generated in-hospital information.
[0110] In FIG. 8 , after in step S 1 a patient visits the hospital and in step S 2 the patient finishes its receiving procedures at the reception of a diagnosis and treatment department in which the patient takes diagnosis and treatment, patient information that hospital staff inputs from a terminal at the reception and patient information received from the HIS is stored in the in-hospital server of the diagnosis and treatment department.
[0111] Then, when in step S 3 the temperature and pulse rate of the patient are measured as the pre-treatment of an endoscopic examination, these performance records and vital sign data, which is the measurement result, are inputted from the terminal and are recorded and stored in the in-hospital server.
[0112] When starting the endoscopic examination, as its preparation (step S 4 ), information for specifying an examination instrument, such as an endoscopic device to be used and the like is inputted from the terminal. Then, at the time of examination (step S 5 ), the image data of a sensed endoscopic image, information about used equipment, the performance record of a used instrument is transmitted from the examination device terminal to which each piece of equipment is connected to the in-hospital server. The in-hospital server stores the data in the database, and stores and accumulates it.
[0113] While the patient rests in a recovery room (step S 7 ) aftertheendoscopicexaminationfinishes (step S 6 ), its temperature and pulse rate are measured. Then, these results are inputted from the terminal as vital sign data and are transmitted to the in-hospital server.
[0114] After the endoscopic examination finishes, in step S 8 a doctor in charge prepares an examination report. When preparing this report, the opinion of a doctor, the annotation data of an endoscopic image sensed by examination, diagnosis data are inputted from the terminal and are transmitted to the in-hospital server. Then, in step S 9 the examination result is explained to the patient.
[0115] In step S 10 , the instrument, such as an endoscope or the like, used for the endoscopic examination is cleaned by the endoscope cleaning device, and in step S 11 the instrument is accommodated into a predetermined place. However, in this case, a cleaning cycle log and cleaning history data are transmitted to the in-hospital server as the record of this cleaning.
[0116] The in-hospital information shown in FIG. 8 is transmitted to the in-hospital server via the intra-hospital LAN from time to time. The in-hospital server stores the in-hospital information in the database, and stores and manages it. Then, the manager of the in-hospital server inputs mask information indicating whether the provision to outside the hospital of this in-hospital information is permitted to the in-hospital information. Thus, the external server sucks up only information whose external provision is permitted by this mask information.
[0117] FIG. 9 is a flowchart showing the operational process of the in-hospital server at the time of mask information setting.
[0118] By this process, whether the external provision of the in-hospital information stored in the in-hospital server should be permitted is set in the in-hospital information.
[0119] In FIG. 9 , in step S 21 the manager of the in-hospital server logs in in-hospital server from the in-hospital server or a terminal connected to the in-hospital server via an in-hospital LAN.
[0120] Then, in step S 22 the manager of the in-hospital server inputs an authentication password. Authentication information is referenced by the inputted password and an authentication process is performed. If no authentication permit is given, processes after that are terminated.
[0121] If in the authentication process of step S 22 its authentication is permitted, then in step S 23 the in-hospital server activates a mask information setting application.
[0122] This mask information setting application performs a mask information setting process of setting whether the external provision of the information recorded and stored in the in-hospital server should be permitted. In step S 24 , in the in-hospital server the mask information setting application activated in step S 23 displays a mask information setting screen on which the field s of the in-hospital information stored in the in-hospital server is shown, on the monitor of the terminal logged in the in-hospital server in step S 21 . Then, in step S 25 the manager of the in-hospital server selects the fields of information whose external provision is prohibited from the screen displayed in step S 24 and inputs the fields.
[0123] FIG. 10 shows an example of a mask information setting screen displayed in step S 24 .
[0124] On the screen shown in FIG. 10 , the manager of the in-hospital server selects the field s of information whose external provision is prohibited from “patient information”, “examination information”, “equipment information” and “user information”, by operating a pointing device or the like. Then, the manager selects information fields which should not be published from the detailed information field s of the selected tab 71 by checking a radio button 72 (a field marked with ● indicates the selected field in FIG. 10 ) and records the selected and specified contents by pushing a “register” button 74 . Then, by pushing a “close” button 73 , the setting of mask information is completed. The classification of the in-hospital information stored in the database in the in-hospital server into “patient information”, “examination information”, “equipment information” and “user information” is one example. The in-hospital information can be classified appropriately according to how to define the type of collected and stored information and the data structure of its database.
[0125] When the manager of the in-hospital server selects all information field s whose external provision should be prohibited on the mask information setting screen shown in FIG. 10 and pushes the “register” button 74 on the screen (yes in step S 26 ), in step S 27 the in-hospital server stores and manages non-publishable in-hospital information field data indicating the field s that are selected and inputted in step S 25 , as mask information.
[0126] Then, in step S 28 the in-hospital server generates a definition sentence by the SQL code, for generating publishable in-hospital information View, based on the non-publishable in-hospital information field data stored in step S 27 and executes the definition sentence to generate publishable in-hospital information View. Then, in step S 30 the mask information setting screen is closed and this process is terminated.
[0127] FIG. 11 shows an example of in-hospital information stored in the in-hospital server on the basis of which View is generated in step S 28 .
[0128] FIG. 11 shows act.patient_table in which patient information is stored as its example. This act.patient_table has information field s to be classified as patient information in its column, and the column names of each information field, its Japanese name, its content character and numerical value data, which is not shown in FIG. 11 , corresponding to the column are stored in its line. In this example, in-hospital data collected in the in-hospital server is stored in the database and is stored as act.patient_table, act.study_table, act.equipment_table and act.user_table corresponding to the above-described “patient information”, “examination information”, “equipment information” and “user information”, respectively. Such a table structure is one example, and an appropriate structure can be taken according to how to define the type of collected and stored information and the data structure of a database.
[0129] FIG. 12 shows an example of a definition sentence by the SQL code, for generating publishable in-hospital information View generated in step S 29 .
[0130] The definition sentence shown in FIG. 12 defines how to generate the Views of “patient information”, “examination information” and “equipment information” by SQL commands. A table in which the values of PatientID, PatientName, Age and the like whose publication is prohibited by the non-publishable in-hospital information field data stored in step S 27 of FIG. 10 , in the column of a “patient information” table act.patient_table are replaced with “- - - - -” is generated as Reft.patient_table. Since “examination information” and “equipment information” have no field s whose publication is prohibited by the non-publishable in-hospital information field data, act.study_table and act.equipment_table are generated as ref.study_table and ref.equipment_table, respectively, without performing any modification.
[0131] By executing the definition sentence by SQL, shown in FIG. 12 , a View in which field s whose publication is prohibited are replaced with “- - - - -” is generated. By the external server sucking up this View from the in-hospital server, information whose publication is prohibited can be prevented from externally leaking.
[0132] FIG. 13 is a flowchart showing the process of the external server, performed when sucking up information from the in-hospital server of a hospital.
[0133] In FIG. 13 when the process is started, firstly in step S 41 the staff of a facility, such as a service center activates a publishable in-hospital acquisition application of the external server. Then, this publishable in-hospital acquisition application sucks up information from each hospital using a network.
[0134] In step S 42 , this publishable in-hospital acquisition application displays a selection screen and the staff of a facility, such as a service center selects a hospital from which information is obtained (no in step S 43 ).
[0135] FIG. 14 shows an example of the hospital selection screen displayed on this time.
[0136] In FIG. 14 , a tab 81 “ ”, “ ”, “ ” and “ ” which classify hospital names in order of Japanese alphabet ( ) is selected by operating a pointing device. Then, a target hospital name is selected from the hospital names shown in the selected tab 81 by checking the radio button 82 (a field marked with ● indicates the selected field). Then, the selected and specified contents are recorded by pushing a “connect” button 84 . Then, the selection/specification of the operator is registered by pushing the “close” button 83 , and the flow proceeds to the network connection process to a subsequent hospital.
[0137] When the staff of a facility, such as a service center, selects a hospital on the screen shown in FIG. 14 and pushes the “connect” button 84 (yes in step S 43 ), then in step S 44 the external server is connected to the selected one or plurality of hospital facilities via the network 61 or 62 shown in FIG. 7 . Then, the staff inputs an authentication password for obtaining an authentication permit from the hospital selected in step S 42 and transmits the password to the in-hospital server of a corresponding to make it perform an authentication process. Then, if the authentication permit can be obtained from the in-hospital server, in step S 45 the external server accesses the publishable in-hospital information View that is generated by the in-hospital server in step S 28 of FIG. 9 and is stored in the in-hospital server of the hospital.
[0138] Then, in step S 46 in the external server, the staff specifies and inputs the period of a publishable in-hospital information to be sucked up from the in-hospital server. Then, in step S 47 the publishable in-hospital information corresponding to the specified and inputted period is sucked up, and is stored and managed. If the external server is connected via the network 62 , the network is disconnected and then this process is terminated.
[0139] FIG. 15 shows examples of the publishable in-hospital information sucked up from the hospital by the external server in step S 47 .
[0140] Of a plurality of pieces of publishable in-hospital information sucked up from the in-hospital server by the external server, one shown in FIG. 15A is in-hospital facility information indicating information about endoscopic equipment in the hospital and includes the respective types and numbers of upper endoscopes, lower endoscopes, video processors, treatment instruments used for an endoscope, vital sign monitors and endoscopic systems. One shown in FIG. 15B is examination information indicating information about an endoscopic examination conducted in a hospital includes the name of an examined patient, the date of its visit, an examination starting time, the type of an examination, the name and ID of a used endoscope, the number of sensed endoscopic images, the name of an examining doctor, the names of nurses, the name and number of a used treatment instrument and the name and number of a used medicine. One shown in FIG. 15C is facility information, being information about the maintenance of endoscopic equipment in a hospital and includes the name of a target facility, its date of purchase, its unit price, its used frequency, its date of failure, its repair company, its period of guaranty, its availability and the date of repair application. One shown in FIG. 15D is information about an endoscope cleaning machine and includes the name and ID of an endoscope cleaned by a cleaning machine, the name and ID of a cleaner, a cleaning starting time and various types of cleaning machine setting information at the time of cleaning and the like. One shown in FIG. 15E is in-hospital resources information, being information about endoscopic examination staff and equipment in a hospital and includes the respective numbers of endoscopic doctors, nurses and cleaners in charge, the number of examination per day, the total number of vital sign monitors, endoscopes and video processors.
[0141] If the plurality of pieces of information shown in FIG. 15 is related to the above-described classification of in-hospital information, the in-hospital facility information shown in FIG. 15A , the facility information shown in FIG. 15C and the cleaning machine information shown in FIG. 15D correspond to the equipment information, the examination information shown in FIG. 15B corresponds to the examination information and the in-hospital resources information shown in FIG. 15E corresponds to the user information.
[0142] In FIG. 15 , since the publication of the name of a patient in the examination information is prohibited, in FIG. 15B its field is made “- - - - -” and the external server cannot read the patient name.
[0143] The publishable in-hospital information sucked up from a hospital by the external server can also be stored in the external server as rare data and each service application can process this rare data. Alternatively, the information sucked up by the external server can be processed in advance and each service application can read the data.
[0144] FIG. 16 is a flowchart showing the process of each service application. This service application is executed in the terminal 56 connected to the intra-house LAN 51 in the external facility 50 shown in FIG. 7 or an information processing device connected to the external server 55 via the networks 61 and 62 .
[0145] When the process shown in FIG. 16 is started, firstly in step S 51 a terminal in which each service application operates accesses an external server via an intra-house LAN or the like.
[0146] Then, in step S 52 a service application operating in the terminal makes a user to input an authentication password for obtaining an authentication permit to the external server and transmits the password to the external server to make the external server to perform an authentication process.
[0147] If in step S 52 receiving the authentication permit from the external server, in step S 53 the service application displays a selection screen on the terminal to make the user select a facility for conducting information processing.
[0148] Then, the service application reads the publishable in-hospital information recorded in and managed by the external server, and in step S 55 extracts data needed to provide a service, from this publishable in-hospital information. Then, in step S 56 the service application various types of processes corresponding to the service, using this data. Then, in step S 57 the service application outputs the process result and this process is terminated.
[0149] As described above, according to the data management system in this preferred embodiment, a mechanism for efficiently sucking up necessary in-hospital information from outside the hospital and providing each service can be realized.
[0150] Since of the in-hospital information handled inside the hospital, only one whose external provision is permitted can be externally read out, information whose external provision is prohibited, such as personal information and the like can be prevented from leaking.
[0151] Furthermore, even when a new service using in-hospital information is added and the number of service applications for realizing its services increases, the situation can be easily coped with only by giving the minimum modifications to the existing function.
[0152] Although in the data management system in this preferred embodiment, the exchange of information between a hospital facility and an external facility, such as a service center or the like, is conducted via a network, the information can also be exchanged using a portable storage medium, such as a DVD or the like.
[0153] Although in-hospital information collected in the in-hospital server in a hospital is stored in the database, and stored and managed, this database can be built using not only SQL but also another data manipulation language.
[0154] There is also a conventional data management system in which a terminal installed in a hospital transmits in-hospital information indicating the used state of medical equipment to an information registration server (for example, corresponding to the out-hospital server (out-hospital information processing device) and the external server 55 shown in FIG. 7 ) installed in an external facility for providing a medical service, such as the rental service of medical equipment via a network as a communication line, and the information registration server or the like provides the hospital with a medical service by analyzing the in-hospital information, or charging a fee for the medical service (for example, see re-published WO02/017171 (pages 14˜25, FIGS. 1˜9)).
[0155] If an external facility provides a medical service, based on in-hospital information and charges a fee for the medical service thus, it is preferable to record a variety of in-hospital information on the information registration server in order for the external facility to provide a hospital with better services.
[0156] However, if the law of medical treatment is revised or the policy of a hospital is modified, sometimes part of in-hospital information cannot be transmitted to an information registration server or new in-hospital information can be transmitted to the information registration server.
[0157] If part of in-hospital information cannot be transmitted to an information registration server, better services must be provided to the hospital by transmitting in-hospital information other than the in-hospital information that cannot be transmitted, to the registration server to meet the revised law.
[0158] If new in-hospital information can be transmitted to the information registration server, the new in-hospital information can be added to the in-hospital information and be transmitted to the information registration server. Therefore, an external server can provide the hospital with better medical services.
[0159] In order to meet the revised law and the modified hospital policy to continue to provide better services thus, in-hospital information that is met by the revised law and the modified hospital policy and whose transmission to the information registration server is permitted must coincide with in-hospital information actually recorded in the information registration server.
[0160] Therefore, in order to reset information whose transmission from the hospital to the external facility is permitted to match in-hospital information recorded on the hospital with in-hospital information recorded in the external facility, conventionally the entire data management system commonly provided for the hospital and the external facility is replaced.
[0161] However, it takes much labor and cost to replace the entire data management system commonly provided for the hospital and the external facility.
[0162] Therefore, in the following preferred embodiments, a data management system capable of matching in-hospital information whose transmission to the external facility is permitted, according to the revised law and the modified hospital policy with in-hospital information actually recorded in the external facility while suppressing labor and cost is described.
[0163] FIG. 17 shows a typical data management system capable of matching in-hospital information whose transmission to the external facility is permitted with in-hospital information actually recorded in the external facility.
[0164] The data management system 1000 shown in FIG. 17 comprises a terminal 1002 provided for an information transmitting source facility 1001 (this terminal 1002 (for example, corresponding to the in-hospital server (in-hospital information processing device) and the in-hospital server 45 shown in FIG. 7 )) and an information registration server 1004 (for example, corresponding to the out-hospital server (out-hospital information processing device)) provided for an external facility 1003 , which are connected via a network, such as the Internet or the like.
[0165] The terminal 1002 is connected to an information storage server 1005 provided for the information transmitting source facility 1001 via a network, such as a local area network (LAN) or the like.
[0166] The information storage server 1005 comprises a database (first database). On this database, aplurality of pieces of information (for example, corresponding to the patient information and endoscopic images, inputted by hospital staff, shown in FIG. 8 ) is recorded, and of the plurality of pieces of information, information based on a request from the terminal 1002 is transmitted to the terminal 1002 . The database provided for the information storage server 1005 can also be provided for the terminal 1002 .
[0167] The terminal 1002 comprises a mask setting means 1006 for relating field information indicating its field when the plurality of pieces of information recorded on the database of the information storage server 1005 is classified for each field to mask information indicating whether information corresponding to the field can be transmitted to the information registration server 1004 and recording them as a mask table and a transmitting means 1007 for transmitting modification information based on the mask table whose mask information is already modified to the information registration server 1004 .
[0168] The transmitting means 1007 checks information whose transmission to the information registration server 1004 is permitted, based on a mask table set by the mask setting means 1006 and extracts the checked information from the database of the information storage server 1005 . Then, the transmitting means 1007 transmits the information to the information registration server 1004 .
[0169] The information registration server 1004 is connected to a database management terminal 1008 for recording the information transmitted from the terminal 1002 (for example, corresponding to information shown in FIGS. 15 A˜ 15 E) via a network, such as a LAN or the like. The database management terminal 1008 comprises a database (second database) and records information transmitted from the information registration server 1004 to the database. The database management terminal 1008 can also comprise, for example, a personal computer or the like. The database provided for the database management terminal 1008 can also be provided for the information registration server 1004 .
[0170] The information registration server 1004 comprises a registration information management means 1009 for requesting previous information which is information recorded on the database of the information storage server 1005 before the mask information is modified, of the plurality of pieces of information of the terminal 1002 and recording the information the database of the database management terminal 1008 , or deleting the previous information already recorded in the database of the database management terminal 1008 , based on the modification information transmitted from the terminal 1002 .
[0171] The mask setting means 1006 and the transmitting means 1007 can also be realized by executing a program recorded on random-access memory (RAM), read-only memory (ROM) or the like provided for the terminal 1002 by a central processing unit (CPU) or the like.
[0172] The registration information management means 1009 can also be realized by a CPU or the like executing a program recorded, for example, on RAM, ROM or the like, provided for the information registration server 1004 .
[0173] In the data management system 1000 , when the mask information is modified, the previous information is recorded on the database of the database management terminal 1008 , or the previous information already recorded on the database of the database management terminal 1008 is deleted.
[0174] Thus, information whose transmission from the terminal 1002 to the information registration server 1004 is permitted and information recorded on the database of the database management terminal 1008 can usually be matched.
[0175] Next, the case where the data management system 1000 is used as a data management system in which a terminal provided for a hospital and an information registration server provided for an external facility for providing medical services are connected via a network is studied.
[0176] FIG. 18 shows the preferred embodiment in which the data management system 1000 is used as a data management system in which a terminal provided for a hospital and an information registration server provided for an external facility are connected via a network. The same reference numerals are attached to the same components as shown in FIG. 17 .
[0177] The data management system 200 shown in FIG. 18 comprises the terminal 1002 provided for a hospital 201 and an information registration server 1004 provided for an external facility 202 for providing the hospital 201 with medical services, which are connected via a network 2003 .
[0178] The terminal 1002 is connected to the information storage server 1005 via a network 204 . The information storage server 1005 is connected to a personal computer (PC) client 207 (for example, corresponding to the examination device terminal 22 ) provided with an endoscopic examination equipment 205 and an endoscopic examination equipment 206 (for example, corresponding to the endoscopic examination device 21 ), via the network 204 . In-hospital information indicating the examination results obtained by the endoscopic examination equipment 205 and 206 is transmitted from the endoscopic examination equipment 205 and the PC client 207 to the information storage server 1005 via the network 204 and is recorded on the database provided for the information storage server 1005 .
[0179] The terminal 1002 comprises the mask setting means 1006 and the transmitting means 1007 .
[0180] The mask setting means 1006 relates field information indicating its field when the plurality of pieces of information recorded on the database of the information storage server 1005 is classified for each field to mask information indicating whether information corresponding to the field can be transmitted to the information registration server 1004 and records them on the terminal 1002 as the mask table 208 .
[0181] The transmitting means 1007 extracts in-hospital information from the database of the information storage server 1005 , based on the mask table 208 and transmits the information to the information registration server 1004 .
[0182] When the mask information is modified, the transmitting means 1007 transmits the mask table 28 whose mask information is already modified to the information registration server 1004 .
[0183] The information registration server 1004 is connected to the database management terminal 1008 for recording the in-hospital information transmitted from the terminal 1002 via a network 209 . The database management terminal 1008 comprises a database and records the in-hospital information transmitted from the information registration server 1004 to the database.
[0184] The information registration server 1004 comprises a registration information management means 1009 for recording the mask table 208 whose mask information is not yet modified and the mask table 208 whose mask information is already modified as an old mask table 300 and a new mask 301 , respectively, and transmitting the in-hospital information transmitted from the terminal 1002 to the database management terminal 1008 .
[0185] FIG. 19 is a flowchart showing the operation of the terminal 1002 .
[0186] Firstly, in step A 1 the terminal 1002 relates each field to mask information indicating whether in-hospital information corresponding to the field should be transmitted to the information registration server 1004 , based on the operation of a user, and sets a mask table (mask setting).
[0187] FIG. 20 shows an example of a mask setting graphical user interface (GUI) screen displayed on the monitor or the like provided for the terminal 1002 .
[0188] As shown in FIG. 20 , the mask setting GUI screen 400 comprises a field display area 401 for displaying fields and a checkbox display area 402 for displaying a checkbox corresponding to each field.
[0189] In FIG. 20 , checkboxes corresponding to “patient name” and “weight” are checked. A setting completion button or the like can also be provided on the mask setting GUI screen 400 and the mask setting can be terminated when the setting completion button is pushed.
[0190] When the user checks a checkbox, the transmission of the in-hospital information of fields corresponding to the checkboxes is prohibited. Specifically, in FIG. 20 , since the checkboxes corresponding to “patient name” and “weight” are checked, the transmission to the information registration server 1004 of in-hospital information corresponding to “patient name” and “weight” is prohibited. The transmission to the information registration server 1004 of in-hospital information corresponding to the other fields “examination doctor”, “examination type” and “date of examination” whose checkboxes are not checked is permitted. If the law is revised or the policy of the hospital 201 is modified and the transmission to the information registration server 1004 of in-hospital information corresponding to the field “examination doctor” is prohibited, the user checks a checkbox corresponding to the field “examination doctor”.
[0191] FIG. 21 shows an example of the mask table 208 recorded on the terminal 1002 . The mask table 208 shown in FIG. 21 corresponds to the mask setting of each checkbox of the mask setting GUI screen 400 shown in FIG. 20 .
[0192] As shown in FIG. 21 , the mask table 208 stores and comprises many mask information records 500 ( 500 - 1 , 500 - 2 , 500 - 3 , 500 - 4 , 500 - 5 , . . . ). Each mask information record 500 comprises a field information area 501 for recording field information and a mask information area 502 for recording mask information indicating whether in-hospital information corresponding to field information should be transmitted to the information registration server 1004 .
[0193] In FIG. 21 , “examination doctor” and “not exist” are recorded in the field information area 501 and mask information area 502 , respectively, of the mask information record 500 - 3 . In FIG. 21 , “exist” recorded in the mask information area 502 indicates that the transmission to the information registration server 1004 of in-hospital information is prohibited. In FIG. 21 , “not exist” recorded in the mask information area 502 indicates that the transmission to the information registration server 1004 of in-hospital information is permitted.
[0194] Then, in step A 2 of FIG. 19 , when the user finishes the mask setting, the terminal 1002 writes the mask table 208 whose setting is finished over the mask table 208 used up to now and stores it.
[0195] Then, the terminal 1002 transmits the mask table 208 overwritten and stored to the information registration server 1004 .
[0196] FIG. 22 is a flowchart showing a series of operations covering transmitting a mask table 208 from the terminal 1002 up to recording the mask table 208 on an information registration server 1004 .
[0197] Firstly, in step B 1 , the terminal 1002 transmits the mask table 208 whose setting is finished to the information registration server 1004 .
[0198] FIG. 23 shows an example of the mask table 208 whose setting is finished and which is transmitted to the information registration server 1004 .
[0199] The mask table 208 shown in FIG. 23 is one in which “not exist” recorded in the mask information area 502 of the mask information record 500 - 3 in the mask table 208 shown in FIG. 21 is modified to “exist”. In this case, characters “exist” recorded in the mask information area 502 of the mask information record 500 - 3 can be bold so that the modification of the mask information can be visually detected by the user. Alternatively, the characters can be emphasized by changing their style to italic, changing their color or so on.
[0200] After the mask table is set thus, the set mask table 208 is transmitted from the terminal 1002 to the information registration server 1004 .
[0201] FIG. 24 shows another example of the mask table 208 whose setting is finished and which is transmitted to the information registration server 1004 . The mask table 800 shown in FIG. 24 is one in which characters recorded in the mask information area 502 of the mask information record 500 - 3 in the mask table 208 shown in FIG. 21 is modified from “not exist” to “exist” as in FIG. 23 .
[0202] The mask table 800 shown in FIG. 24 comprises only mask information record 801 ( 801 - 1 ) whose mask information is already modified. The mask information record 801 comprises a field information area 802 for recording field information and a mask information area 803 for recording mask information indicating whether in-hospital information corresponding to field information should be transmitted to the information registration server 1004 .
[0203] In FIG. 24 , “examination doctor” and “exist” are recorded in the field information area 802 and mask information area 803 , respectively, of the mask information record 801 - 1 .
[0204] As described above, the mask table 800 can comprise only mask information record 801 whose mask information is already modified and be transmitted from the terminal 1002 to the information registration server 1004 .
[0205] Then, in step B 2 of FIG. 22 , the information registration server 1004 receives the mask table 208 whose setting is finished.
[0206] Then, in step B 3 , the information registration server 1004 renames the old mask table 208 used up to now to record it as an old mask table 300 .
[0207] Then, in step B 4 , the information registration server 1004 records the new mask table 208 whose setting is finished and is transmitted from the terminal 1002 as a new mask table 301 .
[0208] Then, in step B 5 , the information registration server 1004 notifies the terminal 1002 of the reception completion of the mask table 208 .
[0209] Thus, the information registration server 1004 records the old mask table 300 and the new mask table 301 and compares the new mask table 301 with the old mask table 300 to check which mask information is modified.
[0210] Then, the information registration server 1004 requests in-hospital information corresponding to the modified mask information of the terminal 1002 , and transmits the information to the database management terminal 1008 or deletes it from the database of the database management terminal 1008 .
[0211] FIG. 25 shows an example of a database provided for the database management terminal 1008 .
[0212] The database 900 shown in FIG. 25 stores many in-hospital information records 901 ( 901 - 1 , 901 - 2 , 901 - 3 , 901 - 4 , 901 - 5 , . . . ). Each in-hospital information record 901 comprises a field information area 902 for recording field information and an examination contents area 903 ( 903 - 1 , 903 - 2 , . . . ) for recording examination contents obtained by endoscopic examination equipment 205 and 206 . The examination contents area 903 is added every time examination contents are transmitted from the terminal 1002 . For example, it can be added in ascending order of date.
[0213] In FIG. 25 , “examination doctor” and examination contents are recorded in the field information area 902 and examination contents areas 903 - 1 and 903 - 2 , respectively, of the in-hospital information record 901 - 3 . “∘” shown in the examination contents area 903 indicates that some examination contents are recorded. “X” shown in the examination contents area 903 indicates that no examination contents are recorded. The database 900 shown in FIG. 25 which is provided for the information storage server 1005 records in-hospital information in all the examination contents areas 903 .
[0214] Next, the operations of the registration information management means 1009 of comparing the old mask table 300 with the new mask table 301 and deleting in-hospital information corresponding to modified mask information from the database of the database management terminal 1008 are described.
[0215] FIG. 26 is a flowchart showing the operations of the data management system 1000 in the case where in-hospital information corresponding to the modified mask information is deleted from the database of the database management terminal 1008 .
[0216] Firstly, in step C 1 , the registration information management means 1009 reads the recorded old mask table 300 and new mask table 301 .
[0217] Then, in step C 2 , the registration information management means 1009 compares the old mask table 300 with the new mask table 301 .
[0218] FIG. 27 shows an example of the mask table in the case where the old mask table 300 and the new mask table 301 are combined in order to compare them. The mask table shown in FIG. 27 is obtained by combining the mask tables 208 shown in FIG. 21 and 23 .
[0219] The mask table 1100 shown in FIG. 27 stores many mask information records 1100 ( 1101 - 1 , 1101 - 2 , 1101 - 3 , 1101 - 4 , 1101 - 5 , . . . ). Each mask information record 1101 comprises a field information area 1102 for recording field information, an old mask information area 1103 for recording the mask information of the oldmask table 300 and a new mask information area 1104 for recording the mask information of the new mask table 301 .
[0220] In FIG. 27 , “examination doctor”, “not exist” and “exist” are recorded in the field information area 1102 , old mask information area 1103 and new mask information area 1104 , respectively, in the mask information record 1101 - 3 .
[0221] If “not exist” and “exist” are recorded in the old mask information area 1103 and new mask information area 1104 , respectively, in the mask information record 1101 thus, the registration information management means 1009 determines that in-hospital information corresponding to the field information of the mask information record 1101 cannot be recorded on the database of the database management terminal 1008 .
[0222] Then, in step C 3 of FIG. 26 , the registration information management means 1009 retrieves field information corresponding to the mask information whose modification is detected from the database of the database management terminal 1008 .
[0223] Then, in step C 4 , the registration information management means 1009 nullifies all the filed values of examination contents area corresponding to the retrieved field information in the database of the database management terminal 1008 .
[0224] FIG. 28 shows the database of the database management terminal 1008 in the case where all the examination contents areas corresponding to the modified mask information are nullified. The database shown in FIG. 28 is a part of the database 900 shown in FIG. 25 .
[0225] The database 900 shown in FIG. 28 shows that in-hospital information recorded in all the examination contents areas 903 corresponding to the in-hospital information record 901 - 3 are deleted as a result of the comparison between the old mask table 300 and the new mask table 301 in the mask table 1100 shown in FIG. 27 . Specifically, the database 900 shown in FIG. 28 shows that when in-hospital information to be recorded in the examination contents area 903 - 3 is transmitted from the terminal 1002 to the information registration server 1004 , the mask information area 502 of the mask information record 500 - 3 in the mask table 208 shown in FIG. 21 is modified from “not exist” to “exist”, the in-hospital information recorded in the examination contents areas 903 - 1 and 903 - 2 of the database of the database management terminal 1008 up to then has been deleted.
[0226] Thus, in-hospital information recorded on the database of the database management terminal 1008 can be deleted before the mask table 208 is modified.
[0227] In the database of the database management terminal 1008 , the field values of all the examination contents areas corresponding to the retrieved field information can also be set in such a way as to be referenced, instead of nullifying the field values of all the examination contents areas corresponding to the retrieved field information.
[0228] Next, the operations of the registration information management means 1009 of comparing the new mask table 301 with the old mask table 300 and adding in-hospital information corresponding to the modified mask information to the database of the database management terminal 1008 are described.
[0229] FIG. 29 is a flowchart showing the operation of additionally recording in-hospital information corresponding to the modified mask information to the database of the database management terminal 1008 .
[0230] Firstly, in step D 1 , the registration information management means 1009 reads the recorded old mask table 300 and new mask table 301 .
[0231] Then, in step D 2 , the registration information management means 1009 compares the new mask table 301 with the old mask table 300 .
[0232] FIG. 30 shows an example of the mask table obtained by combining the old mask table 300 and new mask table 301 in order to compare the new mask table 301 with the old mask table 300 .
[0233] The mask table 1400 shown in FIG. 30 stores many mask information records 1401 ( 1401 - 1 , 1401 - 2 , 1401 - 3 , 1401 - 4 , 1401 - 5 , . . . ). Each mask information record 1401 comprises a filed information area 1402 for recording field information, an old mask information area 1403 for recording the mask information of the old mask table 300 and a new mask information area 1404 for recording the mask information of the new mask table 301 .
[0234] In FIG. 30 , “weight”, “exist” and “not exist” are recorded in the field information area 14 O 2 , old mask information area 1403 and new mask information area 1404 , respectively, of the mask information record 1401 - 2 .
[0235] If “exist” and “not exist” are recorded in the old mask information area 1403 and new mask information area 1404 , respectively, of the mask information record 1401 thus, the registration information management means 1009 determines that in-hospital information corresponding to the field information of the mask information record 1401 can be recorded on the database of the database management terminal 1008 .
[0236] Then, in step D 3 of FIG. 29 , the registration information management means 1009 requests lacking in-hospital information corresponding to the modified mask information of the terminal 1002 . When requesting the lacking in-hospital information of the terminal 1002 , an examination contents area 903 corresponding to the lacking in-hospital information can also be requested. As shown in FIG. 30 , the registration information management means 1009 can also delete the entire mask information record 1401 in which “exist” and “not exist” are recorded in the old mask information area 1403 and the new mask information area 1404 , respectively, from the database of the database management terminal 1008 and request the corresponding entire new mask information record 1401 of the terminal 1002 .
[0237] Then, in step D 4 , the terminal 1002 extracts in-hospital information (field value) based on the request transmitted from the information registration server 1004 from the database of the information storage server 1005 . In this case, as shown in FIG. 12 , the in-hospital information can also be extracted by the structured query language (SQL), another database control language.
[0238] FIG. 31 shows the data table of the in-hospital information extracted from the database of an information storage server 1005 . The data table shown in FIG. 31 records in-hospital information corresponding to the field information “weight”.
[0239] The data table 1500 shown in FIG. 31 stores and comprises many lacking information records 1501 ( 1501 - 1 , 1501 - 2 , 1501 - 3 , . . . ) for recording lacking in-hospital information. Each lacking information record 1501 comprises an examination contents area 1502 for recording examination contents and a weight area 1503 for recording weight.
[0240] In FIG. 31 , “examination 1” and “68” are recorded in the examination contents area 1502 and weight area 1503 , respectively, of the lacking information record 1501 .
[0241] Then, in step D 5 of FIG. 29 , the terminal 1002 transmits the extracted in-hospital information to the information registration server 1004 .
[0242] Then, in step D 6 , the information registration server 1004 receives the in-hospital information.
[0243] Then, in step D 7 , the information registration management means 1009 transmits the received in-hospital information to the database management terminal 1008 and records it on the database of the database management terminal 1008 .
[0244] FIG. 32 shows how to additionally record the received in-hospital information on the database of the database management terminal 1008 . The database 900 shown in FIG. 32 is a part of the database 900 shown in FIG. 25 .
[0245] The database 900 shown in FIG. 32 the in-hospital information is additionally recorded in all the examination contents areas 903 corresponding to the in-hospital information record 901 - 2 as the result of comparison between the old mask table 300 and the new mask table 301 in the mask table 1400 shown in FIG. 30 . Specifically, the database 900 shown in FIG. 32 indicates that when transmitting in-hospital information to be recorded in the examination contents area 903 - 3 from the terminal 1002 to the information registration server 1004 , the mask information area 502 of the mask information record 500 - 2 in the mask table 208 shown in FIG. 21 is modified from “exist” to “not exist” and the in-hospital information recorded in the examination contents areas 903 - 1 and 903 - 2 in the database of the information storage server 1005 up to then has additionally recorded on the database of the database management terminal 1008 .
[0246] Thus, in-hospital information recorded on the database of the information storage server 1005 can be additionally recorded on the database of the database management terminal 1008 in the mask table 208 is modified.
[0247] As described above, when the mask information is modified, the data management system 1000 records the previous information recorded on the database of the information storage server 1005 before the mask information is modified on the database of the database management terminal 1008 or deletes the previous information recorded on the database of the database management terminal 1008 . Therefore, in-hospital information whose transmission from the terminal 1002 to the information registration server 1004 is permitted and in-hospital information actually recorded on the database of the database of the database management terminal 1008 can be always matched.
[0248] Thus, even when the in-hospital information law is revised or the hospital policy is modified, medical services and the like can be correctly analyzed. Since there is no need to replace the entire data management system, the labor and cost of building a data management system can be suppressed.
[0249] The present invention is not limited to the above-described preferred embodiments and various configurations in “claims” can be adopted. For example, the following configuration modification is possible.
[0250] FIG. 33 shows the configuration of another preferred embodiment of the data management system 1000 . The same reference numerals are attached to the same components as shown in FIG. 18 .
[0251] The data management system 1700 shown in FIG. 33 differs from the data management system 200 shown in FIG. 18 in that the transmitting means 1007 of the terminal 1002 compares a new mask table 1702 with an old mask table 1701 and if there is transmission-permitting mask information for modifying information whose transmission is prohibited to one whose transmission is permitted in the new mask table 1702 , previous in-hospital information corresponding to the transmission-permitting mask information and an add instruction for additionally recording the previous in-hospital information corresponding to the transmission-permitting mask information for modifying information whose transmission is prohibited to one whose transmission is permitted to the database of the database management terminal 1008 , the transmitting means 1007 transmits to the information registration server 1004 . If there is transmission-prohibiting mask information for modifying information whose transmission is permitted to one whose transmission is prohibited in the new mask table 1702 , a delete instruction for deleting the previous in-hospital information corresponding to the transmission-prohibiting mask information is deleted from the database of the database management terminal 1008 is transmitted to the information registration server 1004 . The data management system 1700 also differs from the data management system 200 in that when the additional instruction is transmitted from the terminal 1002 , the registration information management means 1009 of the information registration server 1004 additionally records previous in-hospital information corresponding to the transmission-permitting mask information to the database of the database management terminal 1008 and if a delete instruction is transmitted from the terminal 1002 , the previous in-hospital information corresponding to the transmission-prohibiting mask information is deleted from the database of the database management terminal 1008 .
[0252] Firstly, the operation of the terminal 1002 is described.
[0253] FIG. 34 is a flowchart showing the operation of the terminal 1002 of the data management system 1700 .
[0254] Firstly, in step E 1 , the terminal 1002 relates each field to mask information indicating whether in-hospital information corresponding to the field should be transmitted to the information registration server 1004 by the operation of a user to set a mask table (mask setting).
[0255] Then, in step E 2 , the terminal 1002 renames the old mask table used up to now and records it as an old mask table 1701 .
[0256] Then, in step E 3 , the terminal 1002 records the new mask table set in step E 1 as a new mask table 1702 .
[0257] Next, the operation of additionally recording in-hospital information corresponding to the modified mask information on the database of the database management terminal 1008 if there is modified mask information in the new mask table 1702 when the new mask table 1702 and the old mask table 1701 are compared is described.
[0258] FIG. 35 is a flowchart showing the operation of the data management system 1700 , of additionally recording in-hospital information on the database of the database management terminal 1008 .
[0259] Firstly, in step F 1 , the transmitting means 1007 of the terminal 1002 reads the recorded old mask table 1701 and new mask table 1702 .
[0260] Then, in step F 2 , the transmitting means 1007 of the terminal 1002 compares the new mask table 1702 with the old mask table 1701 .
[0261] Then, in step F 3 , the transmitting means 1007 of the terminal 1002 extracts in-hospital information corresponding to the modified mask information from the database of the information storage server 1005 . The transmitting means 1007 of the terminal 1002 can also extracts in-hospital information recorded on the database of the information storage server 1005 before the mask information is modified, of all pieces of in-hospital information corresponding to the modified mask information from the database of the information storage server 1005 . In-hospital information can also be extracted by an SQL or another database control language.
[0262] Then, in step F 4 , the transmitting means 1007 of the terminal 1002 transmits the extracted in-hospital information, an add instruction for additionally recording the in-hospital information on the database of the database management terminal 1008 , and the recording destination of the database to the information registration server 1004 .
[0263] Then, in step F 5 , upon receipt of the add instruction, the registration information management means 1009 of the information registration server 1004 transmits the in-hospital information and the recording destination of the database to the database management terminal 1008 and records the in-hospital information on the database of the database management terminal 1008 , based on the recording destination of the database.
[0264] Next, the operations of the terminal 1002 , of comparing the new mask table 1702 with the old mask table 1701 and deleting in-hospital information corresponding to the modified mask information from the database of the database management terminal 1008 are described.
[0265] FIG. 36 is a flowchart showing the operation of the data management system 1700 , of deleting in-hospital information from the database of the database management terminal 1008 .
[0266] Firstly, in step G 1 , the transmitting means 1007 of the terminal 1002 reads the recorded old mask table 1701 and new mask table 1702 .
[0267] Then, in step G 2 , the transmitting means 1007 of the terminal 1002 compares the new mask table 1702 with the old mask table 1701 .
[0268] Then, in step G 3 , the transmitting means 1007 of the terminal 1002 transmits a delete instruction for deleting in-hospital information corresponding to the modified mask information from the database of the database management terminal 1008 , to the information registration server 1004 .
[0269] Then, in step G 4 , the registration information management means 1009 of the information registration server 1004 delete in-hospital information from the database of the database management terminal 1008 , based on the received delete instruction. In the database of the database management terminal 1008 , in-hospital information corresponding to the modified mask information can also be set not tobe referenced, instead of deleting the in-hospital information corresponding to the modified mask information.
[0270] As in this data management system 1700 , the terminal 1002 can also determine whether in-hospital information recorded on the database of the information storage server 1005 before the mask information is modified should be recorded on the database of the database management terminal 1008 .
[0271] Next, a data management system in another preferred embodiment (hereinafter called “another data management system”) is described.
[0272] This other data management system differs from the data management system 1000 shown in FIG. 18 in that the transmitting means 1007 of the terminal 1002 transmits an instruction for recording previous in-hospital information recorded on the database of the information storage server 1005 before the mask information is modified, of a plurality of pieces of in-hospital information recorded on the database of the information storage server 1005 and an add instruction for recording additionally record the previous in-hospital information for deleting the previous in-hospital information to be recorded on the database of the database management terminal 1008 , or a delete instruction for deleting the previous in-hospital information to be recorded on the database of the database management terminal 1008 , without comparing the old and new mask tables and in that if the terminal 1002 transmits an add instruction, the registration information management means 1009 records the previous in-hospital information on the database of the database management terminal 1008 and if the terminal 1002 transmits a delete instruction, the registration information management means 1009 deletes the previous in-hospital information to be recorded on the database of the database management terminal 1008 .
[0273] Next, the operation of additionally recording in-hospital information corresponding to the modified mask information on the database of the database management terminal 1008 in this other data management system is described.
[0274] FIG. 37 is a flowchart showing the operation of this other data management system, of additionally recording in-hospital information on the database of the database management terminal 1008 .
[0275] Firstly, in step H 1 , each field is related to mask information indicating whether in-hospital information corresponding to the field should be transmitted to the information registration server 1004 as a mask table by the operation of a user to modify specific mask information.
[0276] Then, in step H 2 , the terminal 1002 extracts in-hospital information corresponding to the modified mask information from the database of the information storage server 1005 . The terminal 1002 can also extract in-hospital information recorded on the database of the information storage server 1005 before the mask information is modified, of all pieces of in-hospital information corresponding to the modified mask information from the information storage server 1005 . In-hospital information can also be extracted by an SQL and another database control language.
[0277] Then, in step H 3 , the terminal 1002 transmits the extracted in-hospital information, an add instruction for additionally recording the in-hospital information on the database of the database management terminal 1008 and the recording destination (field name) of the database to the information registration server 1004 . The terminal 1002 can also transmits the extracted in-hospital information, the add instruction for additionally recording the in-hospital information on the database of the database management terminal 1008 and the recording destination (field name) of the database to the information registration server 1004 on a list.
[0278] Then, in step H 4 , the information registration server 1004 receives the in-hospital information, the add instruction and the recording destination of the database that are transmitted from the terminal 1002 .
[0279] Then, in step H 5 , upon receipt of the add instruction, the registration information management means 1009 of the information registration server 1004 transmits the in-hospital information and the recording destination of the database to the database management terminal 1008 and records the in-hospital information on the database of the database management terminal 1008 , based on the recording destination of the database.
[0280] Next, the operation of this other data management system, of deleting in-hospital information corresponding to the modified mask information from the database of the database management terminal 1008 is described.
[0281] FIG. 38 is a flowchart showing the operation of this other data management system, of deleting in-hospital information from the database of the database management terminal 1008 .
[0282] Firstly, in step J 1 , each field is related to mask information indicating whether in-hospital information corresponding to the field should be transmitted to the information registration server 1004 as a mask table by the operation of a user to modify specific mask information.
[0283] Then, in step J 2 , the terminal 1002 transmits a delete instruction deleting in-hospital information corresponding to the modified mask information from the database of the database management terminal 1008 to the information registration server 1004 .
[0284] Then, in step J 3 , the registration information management means 1009 of the information registration server 1004 deletes the in-hospital information from the database of the database management terminal 1008 , based on the delete instruction transmitted from the terminal 1002 . In the database of the database management terminal 1008 , in-hospital information corresponding to the modified mask information can also be set not to be referenced, instead of deleting the in-hospital information corresponding to the modified mask information.
[0285] As in this other data management system, it can also be determined whether the in-hospital information corresponding to the modified mask information should be recorded on the database of the database management terminal 1008 without comparing the old and new mask tables.
[0286] Alternatively, in the above-described preferred embodiment, each of the terminal 1002 and the information registration server 1004 can be provided with a correspondence table relating field information to a simple symbol, such as a figure or the like and recording them. In this case, when the terminal 1002 transmits in-hospital information to the information registration server 1004 , the simple symbol can be transmitted instead of the field information and the information registration server 1004 can refer to the correspondence table.
[0287] By transmitting the simple symbol instead of the field information thus when transmitting in-hospital information, the amount of information to be transmitted can be reduced.
[0288] In the above-described preferred embodiment, in-hospital information can also be added to and recorded on the database of the database management terminal 1008 and then the fact can also be returned to the terminal 1002 .
[0289] Alternatively, in the above-described preferred embodiment, after in-hospital information is deleted from the database of the database management terminal 1008 , such a notice can be returned to the terminal 1002 .
[0290] Although in the above-described preferred embodiment, when a mask table is modified, the contents of the database of the database management terminal 1008 are updated, the currently used mask table and the contents of the database of the database management terminal 1008 can also be compared in intervals of a prescribed elapsed time and the contents of the database of the database management terminal 1008 can be updated based on the comparison result.
[0291] Thus, according to the above-described preferred embodiment, when mask information is modified, previous information is recorded on the database of the information registration server 1004 or previous information recorded on the database is deleted. Therefore, information whose transmission from the terminal 1002 to the information registration server 1004 is permitted can be always matched with information recorded on the database of the information registration server 1004 .
[0292] By providing the terminal 1002 and the information registration server 1004 for the hospital 201 and the external facility 202 for providing medical services, even when the medical law is revised or the policy of the hospital 202 on which in-hospital information should be stored outside the hospital 202 is modified, in-hospital information whose transmission from the terminal 1002 to the information registration server 1004 is permitted and in-hospital information recorded on the database of the information registration server 1004 can be always matched. Therefore, a medical service for analyzing in-hospital information recorded on the database and providing the hospital 202 with it can be correctly realized.
[0293] In this case, since there is no need to replace the entire data management system, the labor and cost of re-building a database handled in the data management system can be suppressed. | Mask information for instructing the prohibition of information which cannot be serviced to the outside, is set and inputted by a manager so that the information, the permission of service of which is indicated by the mask information is exclusively sucked up from an in-hospital server by an external server outside the hospital. A service application created for each service reads out and exploits the information needed by itself, from the in-hospital information sucked up by the external server. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This invention claims priority to currently pending U.S. patent application Ser. No. 14/166,467 filed on Jan. 28, 2014 and entitled, “Voltage Profile Based Fault Location Identification System and Method of Use”, which claims priority to U.S. Provisional Patent Application No. 61/757,507 filed on Jan. 28, 2013 and entitled, “Voltage Profile Based Fault Identification”.
STATEMENT OF GOVERNMENT INTEREST
This invention was made with Government support under Grant No. EEC0812121 awarded by the National Science Foundation. The Government has certain rights in the invention.
FIELD OF INVENTION
This invention relates to a voltage profile based fault location identification system for use in a power distribution system. The voltage profile based fault location identification system includes power electronic converters and employs a short circuit limiting fault current.
BACKGROUND OF INVENTION
The IEEE interconnection standard recommends that the distributed resources (DRs) of a power distribution system be disconnected from the power distribution system when the voltage level falls below a recommended threshold to ensure that the distributed resources do not inject power onto the main power grid of the power distribution system. The IEEE interconnection standard is additionally based on the fact that as the voltage level of the distribution system drops, the distributed resource's voltage reference from the substation may no longer be available or may no longer be accurate.
Identifying the location of a fault in a traditional power system is a challenging task. Electric power only flows in one direction, i.e. from the substation to the various loads. Therefore, when a severe short circuit fault occurs in a distribution system, there is an associated current rise and accompanying voltage sag near the faulted node which extends to every node that is downstream of the faulted node. The fault protection system of a power distribution system currently known in the art responds to the short circuit fault by isolating the assumed faulted nodes and all the downstream nodes of the actual faulted node.
In a power distribution system containing distributed resources, most fault location technologies known in the art ignore the presence of the distributed resources by assuming either low distributed resource penetration or no power injection from the distributed resources during a fault situation. While there are additional fault location technologies known in the art that do consider the presence of distributed resources, these technologies do not consider a current limited system when a fault situation does occur.
Accordingly, what is needed in the art is a system and method for fault location identification in a power distribution system that addresses the presence of distributed resources and provides a current limited system when a fault occurs.
SUMMARY OF THE INVENTION
The present invention provides a method to ensure that distributed resources remain connected to the circuit to assist in the fault location by continuing to inject current in the distribution system. The system contains a plurality of power electronic based converters which convert local direct current (DC) of the distributed resources (DRs) to the power grid alternating current (AC). These converters also have the ability to limit the current in the system when a fault occurs; hence, protecting the system equipment against high fault currents.
In one embodiment of the present invention, a method of identifying the location of a fault in a power distribution system is provided. In the present invention, the power distribution system includes a plurality of distributed resources, and the method includes, injecting, by one or more of the plurality of distributed resources, a current into the power distribution system, generating a voltage profile resulting from the injection of current by the one or more distributed resources and analyzing the voltage profile to identify the location of the fault in the power distribution system.
In an additional embodiment, the present invention provides a system for locating a fault in a power distribution system. The system includes a power distribution system including a plurality of distributed resources coupled to the power distribution system, one or more of the plurality of distributed resources comprising a controllable voltage source converter configured to inject a current into the power distribution system. The system further includes, a voltage profile generator configured for generating a voltage profile resulting from the injection of current by the one or more distributed resources and an analyzer configured for analyzing the voltage profile to identify the location of the fault in the power distribution system.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the disclosure set forth hereinafter and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is voltage profile for a fault at node 2 and node 6 in a traditional distribution system, wherein the system containing no distributed resources or they are disconnected during the fault in accordance with an embodiment of the present invention.
FIG. 2 is voltage profile for a fault at node 2 and node 6 in a distribution system containing distributed resources in accordance with an embodiment of the present invention.
FIG. 3 is voltage profile for a fault at node 6 in a traditional distribution system and one containing distributed resources in accordance with an embodiment of the present invention.
FIG. 4 is a schematic of a test system 11.9 kV ( 8 nodes) in accordance with an embodiment of the present invention.
FIG. 5 is a block diagram illustrating a fault location identification system in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Modern power distribution systems include distributed resources that provide local power generation and are connected to the power distribution system. Such local power generation sources include photovoltaic (PV) systems, wind systems and microturbines. The number and diversity of these local power generation sources is rapidly increasing. As the number of local power sources connected to an existing power distribution system rises, the distribution system fault location methods currently known in the art have become increasingly inadequate. Reasons for the increasing inadequacy of the current fault location methods include unreasonable cost of the system, system complexity (mesh-like topology) and bidirectional power flow in the distribution system that is not addressed by the current fault location methodologies.
The fault location identification system of the present invention takes advantage of the existing topology of the power distribution system. The fault location identification includes controllable voltage source converters (VSCs) to assist in the location of the fault and alters the voltage profile of the system in the presence of a fault condition. Utilizing controllable voltage source converters to locate the fault reduces miss-trips of the circuit breakers that result when relying on the measured voltage when there is no electrical supply in a section of the distribution system as a result of a fault. The incorporation of controllable voltage source converters in the fault location identification system will serve to boost the voltage of the distribution system, locate the fault and provide rapid restoration of the distribution system.
Power distribution system currently known in the art do not employ controllable voltage source converters and the voltage on a feeder associated with the distributed resource is expected to decrease as the distance between the distributed resource and the power distribution system increases. In accordance with the present invention, if the distributed resources in the power distribution system are allowed to inject power, the voltage profile of the system will change as shown in FIG. 1 for the prior art system and FIG. 2 for the fault location identification system of the present invention.
When a severe short circuit fault occurs in a distribution system, there is an associated current rise and accompanying voltage sag near the faulted node which extends to every node that is downstream of the faulted node. The fault protection system of a power distribution system currently known in the art responds to the short circuit fault by isolating the assumed faulted nodes and all the downstream nodes of the actual faulted node. As shown in the graph of FIG. 1 , when a fault occurs in a prior art fault location identification system, the voltage profile resulting from the fault will provides very limited information regarding the location of the fault. For example in the prior art system, when a fault occurs at node 2 100 , in both the 1MVA 105 and 12MVA 110 cases, the distributed resources at nodes 2 100 through 8 125 will be disconnected from the power distribution system by the fault protection system of the power distribution system. Similarly, a fault at node 6 130 will result in the distributed resources at nodes 6 130 through 8 125 being isolated from the rest of the system.
In contrast, as shown in the graph of FIG. 2 , the voltage profile resulting from a fault in accordance with the fault location identification system of the present invention identifies the fault at either node 2 200 or node 6 205 . For example, when a fault occurs at node 2 200 , it is seen that the voltage level 210 drops at node 2 200 , but the voltage level at nodes 3 220 through 8 225 is maintained by the use of the controlled voltage source converters at each of the distributed resources associated with each of nodes 3 220 through 8 225 . Additionally, when a fault occurs at node 6 205 , it is seen that the voltage level 215 drops at node 6 205 , but the voltage level at nodes 7 230 through 8 225 is maintained by the use of the controlled voltage source converters at each of the distributed resources associated with each of nodes 7 230 through 8 225 . As such, the voltage profile provided by the fault location identification system of the present invention results from the injection of current from all the distributed resource at each of the nodes in the system using the controllable voltage source converters.
FIG. 3 illustrates the difference in the voltage profiles of a prior art fault location system and the fault location identification system employing multiple distributed resource with controllable voltage source converters achieved by the present invention. As shown, when a fault occurs at node 6 310 in the prior art system, the voltage level drops at nodes 6 310 through 8 315 , in contrast, with the fault location identification system of the present invention, when a fault occurs at node 6 310 , the voltage level at node 7 320 through 8 315 is maintained by the controllable voltage source converters of the distributed resources at these nodes. As such, the voltage profile for a distributed resource system utilizing the fault location identification system of the present invention clearly indicates the fault at node 6 310 in the system of the present invention, whereas the fault is not clearly identified in the prior art system.
FIG. 4 is a schematic illustrating an exemplary embodiment of the present invention that was used to generate the graphs shown in FIGS. 1-3 . The physical distance between two adjacent distributed resource nodes will also determine if the faulty node can be located accurately. To get an accurate voltage profile for a power distribution system, it is necessary to measure the voltage at multiple nodes in the system. However, making measurements at the nodes is difficult in the prior art systems because there are limited nodes at which a voltage measurement can be performed. In contrast, in the fault location identification system of the present invention which includes a plurality of distributed resources and a controllable voltage source converter associated with each of the distributed resources, each controllable voltage source converters can serve as a measurement unit at which voltage measurement can be performed and used to generate an accurate voltage profile. As shown in FIG. 4 , each of the nodes 1 - 8 are positioned at varying distances from the distribution grid. It is known that the voltage level naturally decreases the farther the node is away from the distribution grid. In the present invention, the controllable voltage source converters at each of the nodes are used to inject current into the power distribution system thereby providing the system with a means for measuring the voltage level at each of the nodes. Knowing the distances between the nodes will improve the accuracy of the fault location identification system of the present invention.
The voltage profile of the power distribution system changes when a fault occurs in the system and the location of the observed voltage drop in the voltage profile is closely related to the location of the fault. Furthermore, most distributed resources provide DC voltage. Therefore, in a DC system, controllable voltage source converters can modulate an AC signal on top of the DC signal and that modulated AC signal profile may be used to locate the fault similarly to the AC system.
In an exemplary embodiment, as illustrated with reference to FIG. 5 , the fault location identification system of the present invention includes a power distribution system 400 and a plurality of distributed resources 405 , 410 , 415 , 420 coupled to the power distribution system 400 . One or more of the plurality of distributed resources 405 , 410 , 415 , 420 comprising a controllable voltage source converter 425 , 430 , 435 , 440 configured to inject a current into the power distribution system 400 . The power distribution system 400 further includes, a voltage profile generator 450 configured for generating a voltage profile resulting from the injection of current by the one or more distributed resources 405 , 410 , 415 , 420 and an analyzer 445 configured for analyzing the voltage profile to identify the location of the fault in the power distribution system 400 .
It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween. | The present invention provides a method to ensure that distributed resources of a power distribution system remain connected to the circuitry of the power distribution system when a fault occurs at a distributed resource node to assist in identifying the location of the fault by continuing to inject current from the distributed resources into the distribution system, wherein at least one of the distributed resources is a cogeneration resource. | 8 |
RELATED APPLICATIONS
The present application is a national-stage filing under 35 U.S.C. §371 of PCT International Application PCT/US2008/009285, titled “Compositions for Compounding and Extrusion of Foamed Fluoropolymers”, filed 1 Aug. 2008, which claims priority to U.S. Provisional Patent Application No. 60/963,322, titled “Compositions for Compounding and Extrusion of Foamed Fluoropolymers for Wire and Cable Applications”, filed 3 Aug. 2007.
The present application also claims priority under 35 U.S.C. §120 from U.S. patent application Ser. No. 12/221,280, titled, “Compositions for Compounding, Extrusion and Melt Processing of Foamable and Cellular Fluoropolymers”, filed 1 Aug. 2008; PCT International Application No. PCT/US2008/009286, titled “Compositions for Compounding, Extrusion and Melt Processing of Foamable and Cellular Fluoropolymers,” filed 1 Aug. 2008 and each of which also takes original priority from both U.S. Provisional Application No. 60/963,322, titled “Compositions for Compounding and Extrusion of Foamed Fluoropolymers for Wire and Cable Applications”, filed 3 Aug. 2007 and U.S. Provisional Application No. 60/953,729, titled “Perfluoropolymer Foamable Composition”, also filed 3 Aug. 2007.
Each of these references is hereby expressly incorporated by reference herein in its entirety.
FIELD OF INVENTION
Wire and cable applications, especially those using copper conductors, utilize the insulative properties of specific polymers over the conductors as insulation and over the entire cable core of insulated conductors as jackets. Cable fillers of varying shapes and size are used as well for their insulative properties and more specifically in communications designs to minimize pair-to-pair crosstalk within a cable as will as mitigating crosstalk between adjacent cables which is commonly referred to as “alien crosstalk.” Jackets and cable fillers provide mechanical and physical properties as well as an ever evolving requirement for enhanced fire performance i.e. (reduced flame spread, ignitability, and smoke evolution.) These mechanical, physical and fire retardancy performance requirements apply to fiber optic cables as well. Cable design demands a balance of these performance requirements and the attributes of processing, e.g., extruding a cellular foamed fluoropolymer (such as a perfluoropolymer) that improves both insulation values e.g. (lower crosstalk in communications cables) while lowering material content and therefore the amount of combustible materials used in a cable. These added performance characteristics through cellular (or microcellular) foaming can additionally lower cost of the overall cable design.
BACKGROUND OF INVENTION
Communication cables have evolved continuously over the years as we have evolved from a voice-based telecommunication network environment to the new structured cabling designs for high-speed data transmission which are commonly referred to as Local Area Networks or LAN's. Technical requirements, standards and guidelines of the Telecommunication Industry Association and Electronic Industry Association (TIA/EIA) and International Standard Organization (ISO) have been developed and published to support high-speed data communication of voice, internet and video. In addition, these requirements continue to evolve with more and more stringent electrical performance needs such that cellular foam insulation and fillers play an increasing role in the cable designs. The primary communications cable designs incorporate twisted copper pairs together to form a balanced transmission line, coaxial cables, and fiber optic cables. All of these cables may be run in a network of a building (LAN's) as separate functional cables or in hybrid or combination cable design.
Furthermore, TIA/EIA has defined standards that are published and recognized as well as industry drafts of soon-to-be published standards for commercial building telecommunication networks. Table 1, which follows, provides those published and pending, or soon-to-be adopted and published Technical Service Bulletin “TSB” standards.
TABLE 1
TIA/EIA Standards
Category 5e
Frequency
ANSI/TIA/EIA-568-A
ISO Class D
Bandwidth
Commercial Building Telecommunications Standard Part 2:
1 to 100 mhz
Balanced Twisted Pair Cabling Component; 2001
Category 6
Frequency
ANSI/TIA/EIA-568-B.2-1
ISO Class E
Bandwidth
Commercial Building Telecommunications Standard Part 2:
1 to 250 mhz
Addendum 1: Transmission Specification for 4 pair 100 ohm
Category 6 Cabling; 2002
Category 6A
Frequency
ANSI/TIA/EIA-568-B.2-10
ISO Class E A
Bandwidth
Commercial Building Telecommunications Standard Part 2:
1 to 500 mhz
Addendum 10: Transmission Specification for 4 Pair 100 ohm
Augmented Category 6 Cabling; TSB pending publication
Category 7
Frequency
TIA not actively developing standard;
ISO Class F
Bandwidth
ISO/EIA-11801, 2 nd Ed. Information Technology - Generic
1 to 600 mhz
Cabling for Customer Premises, 2002
Each of the standards of Table 1 illustrates continued widened bandwidth enabling greater data transmission. The broadening of communication cable bandwidth enhances the electrical characteristics or data bit rate based on the evolving needs of software, hardware and video transmission. The terminology within the standards for testing can be defined as electrical performance within the cable as measured by impedance, near end and far end crosstalk (NEXT & FEXT), attenuation to crosstalk ratio (ACR), ELFEXT, ELNEXT, Power Sum, etc., and the electrical performance that may be transferred to the adjacent cable a.k.a. (alien cross talk) which are measured within similar performance parameters while incorporating a power sum alien cross talk requirement.
Electromagnetic noise that can occur in a cable that runs alongside one or more cables carrying data signals can create alien crosstalk. The term “alien” arises from the fact that this form of G crosstalk occurs between different cables in a group or bundle, rather than between individual wires or circuits within a single cable. Alien Crosstalk can be particularly troublesome because of its effect on adjacent 4 pair cables which degrades the performance of a communications system by reducing the signal-to-noise ratio. Traditionally, alien crosstalk has been minimized or eliminated by aluminum Mylar® shields and/or braid in shielded cable designs i.e. (Category 7 or ISO Class F shielded designs) to prevent electromagnetic fields from ingress or egress from the cable or cables. The use of foamed or blown constructions for symmetrical and asymmetrical airspace designs further improve electrical performance characteristics in that the overall modulus and elasticity of the resulting foamed compounds are reduced leading to final conformations that more closely approach optimal geometries. Specifically, the ability to form inner structures of cables such that these inner structures have little or no plastic memory once the cabling process is completed, ensures that the nested pairs remain in the desired geometric configuration and that the use of foamed fillers, insulations and jackets using air as an insulator act to mitigate alien crosstalk in Unshielded Twisted Pair (UTP) designs i.e. (Category 6 or ISO Class E and Category 6 Augmented or ISO Class E A ).
These Electrical Performance Standards especially for UTP cables (Category 5e, 6, 6A and 7) necessitate improved insulative performance wherein foamed fluoropolymers optimize their inherently excellent insulative values i.e. (dielectric constant and dissipation factor.) Foamed fluoropolymers (such as perfluoropolymers) offer lower cost and lower material content while improving fire retardancy performance by lowering the amount of combustible material in a cable and the overall fire load of Local Area Network cables within a building.
A brief review of the Fire Performance Requirements both in North America and Globally follows:
In 1975, the National Fire Protection Agency (NFPA) recognized the potential flame and smoke hazards created by burning cables in plenum areas, and adopted within the United States, the National Electric Code (NEC), and a standard for flame retardant and smoke suppressant cables. This standard, commonly referred to as “the Plenum Cable Standard”, was later adopted for North America Communications Cabling by Canada and Mexico. The standard permits the use of power-limited type cables that includes communication cables without conduit, so long as the cable exhibits low smoke and flame retardant characteristics. The test method for measuring these characteristics is commonly referred to as the Steiner Tunnel Test. The Steiner Tunnel Test has been adapted for the burning of cables according to the following test protocols: NFPA 262, Underwriters Laboratories (U.L.) 910, or Canadian Standards Association (CSA) FT-6. The test conditions for each of the U.L. 910 Steiner Tunnel Test, CSA FT-6, and NFPA 262 are as follows: a 300,000 BTU/hour flame is applied for 20 minutes to a calculated number of cable lengths based on their diameter that fills a horizontal tray approximately 25 feet long with an enclosed tunnel. This test simulates the horizontal areas (ceilings) in buildings wherein these cables are run.
The criteria for passing the Steiner Tunnel Test UL 910/NFPA 262 are as follows:
A. Flame spread—a maximum flame spread of less that 5.0 feet. B. Smoke generation:
1. A maximum optical density of smoke less than 0.5. 2. An average optical density of smoke less than 0.15.
The premise of the standard is based on the concerns that flame and smoke could travel along the extent of a building plenum area if the electrical conductors and cable were involved and were not flame and smoke resistant. The National Fire Protection Association (“NFPA”) developed the standard to reduce the amount of flammable material incorporated into insulated electrical conductors and jacketed cables. Reducing the amount of flammable material would, according to the NFPA, diminish the potential of the insulating and jacket materials from spreading flames and evolving smoke to adjacent plenum areas and potentially to more distant and widespread areas within a building. The cellular foamable fluoropolymer products of this disclosure can typically reduce the quantity of combustible materials by 30 to 60 percent based on the extent of the foaming process within insulations, fillers and jacket materials.
The products of the present disclosure have also been developed to support the possible adoption of a new NFPA standard referenced as NFPA 255 entitled “Limited Combustible Cables” with less than 50 as a maximum smoke index and NFPA 259 entitled “Heat of Combustion” which includes the use of an oxygen bomb calorimeter that allows for materials with less than 3500 BTU/lb. for incorporation into cabling systems and buildings wherein survivability of the communication network from fires is required i.e. (military installation such as the Pentagon in Washington D.C.).
For these applications requiring survivability from flame spread and smoke generation, the cellular products of the present disclosure will be an effective method for reducing material content and the fuel load of cables in such critical environments.
Table 2 provides a hierarchy of fire performance standards for North America and Europe.
TABLE 2
Flammability Test Methods and Level of Severity for Wire and Cable
Cable Type
Test Method
Ignition Source Output
Duration
Limited
UL2424/NFPA
8,141 KJ/kg
(3,500 BTU/lb.)
10 min.
Combustible
259/255/UL723
CMP
Steiner Tunnel
88 kW
(300 k BTU/hr.)
20 min.
UL 910/NFPA 262
CMR
RISER
154 kW
(527 k BTU/hr.)
30 min.
UL 1666/UL2424/NFPA 259
CPD
Single Burning Item
30 kW
(102 k BTU/hr.)
30 min.
Class D
(20 min burner)
CPD
Modified IEC 60332-3
30 kW
(102 k BTU/hr.)
20 min.
Class D
(Backboard behind ladder
(heat impact))
CM
IEC 60332-3
20.5 kW
(70 k BTU/hr.)
20 min.
CMX
Vertical Tray
20.5 kW
(70 k BTU/hr.)
20 min.
CMUC
IEC 60332-1/ULVW-1
Bunsen Burner
1 min.
(15 sec. Flame)
Cable Fire Performance (Levels of Severity)
NFPA 255 & NFPA 259/LC/CPD Class B1+/UL 2424
(most stringent)
NFPA 262/EN 50289/FT-6/CPD Class B1/UL 910
|
UL 1666 Riser/FT-4/CPD Class C & B2
|
UL 1581 Tray/IEC 60332-3/FT-2/CPD Class D
|
VW 1/IEC 60332-1/FT-1/CPD Class E
(least stringent)
SUMMARY OF THE INVENTION
In the present disclosure the term blowing agent(s), foaming agent(s), are synonymous and may be used interchangeably and are associated with chemical reactions. The term nucleating agent(s) are used in materials that provide sites for the formation of cells resulting from the chemical reaction of the blowing agents or the use of gas injection.
The present disclosure provides for the use of talc or talc derivatives which are natural or synthetic hydrated magnesium silicate compound. Talc (derived from the Persian talc via Arabic talq) is a mineral composed of hydrated magnesium silicate with the chemical formula
H 2 Mg 3 (SiO 3 ) 4 or Mg 3 Si 4 O 10 (OH) 2
The present disclosure refers to talc as natural or synthetic hydrated magnesium silicate. It has been discovered that talc acts independently as a chemical blowing agent in combination with the fluoropolymers (such as perfluoropolymers) of the present invention without the need for additional blowing agents, foaming agents or the need for any other nucleating agent. In certain cases, the talc is compounded into solid fluoropolymer pellets or fluorinated polymeric foamable pellets (in the form of one or more pellets) from which foamed products may be obtained by extrusion or injection molding, wherein the pellets containing talc act as a chemical blowing agent and in some cases as a nucleating agent when the pellets are heated and extruded.
The embodiments within this disclosure reference talc as a chemical blowing agent as well as a nucleating agent except where otherwise noted. The use of talc in combination with the use of a chemical blowing agent or gas injection is also included in the scope the present disclosure.
This disclosure provides a composition, method and system for compounding foamable pellets from fluorinated polymers (either fluoropolymers (such as perfluoropolymers) and furthermore these foamable pellets may be extruded to create a lower cost communications cable, conductor separator, conductor/cable support-separator, jacketing, tape, tube, crossweb, wrap, wire insulation and as well as a conduit tube for individual components or any communications cables, conductor separators, cable support-separators, wire insulation and several combined configurations that exhibit improved electrical, flammability and optical properties.
The foamable fluoropolymers (such as perfluoropolymers) disclosed yield the inherent benefits of reducing the amount of combustible materials within a cable as well as enhancing electrical properties while reducing costs. The blown, foamed or cellular fluoropolymers (such as perfluoropolymers) insulation, jacket, or filler material using a nucleating/foaming agent of talc the chemical composition of which includes MgSiOH; H 2 Mg 3 (SiO 3 ) 4 ; Mg 3 Si 4 O 10 (OH) 2 ; 3MgO+4SiO 2 +H 2 O; MgOH+H 2 O+SiOH; or any derivatives thereof, that synergistically reacts with the fluoropolymers (such as perfluoropolymers) at their elevated or higher extrusion operating temperatures with or without a chemical blowing agent such as magnesium carbonate, calcium carbonate, and a mixture of both magnesium carbonate and calcium carbonate. The nucleating/foaming agent capabilities of talc creates a foam ideally suited for the requirement of Category 6 and 6A UTP insulation, jacket, or and tapes and is highly cost effective at approximately $1.00 per lb. as a replacement for the traditionally used Boron Nitride (nucleating agent) that costs approximately $60.00 per lb. The talc (a chemical blowing agent and it may also act as a nucleating agent), cost significantly less than $1.00 per lb when purchased in larger quantities.
The cost reduction in cost from changing Boron Nitride to talc is one of many benefits. Another benefit of using talc is that insulation, jacketing and filler extrusion may be performed by a relatively simplistic and robust chemical reaction that uses varying extrusion temperatures to foam at various rates or percentages which are desired based on varying talc loadings. Noteworthy, under specific extrusion conditions that are described in further detail, talc itself “foams”. Traditional foaming of fluoropolymers (such as perfluoropolymers) has been via a gas injection extrusion process and the use of nucleated fluoropolymers (such as perfluoropolymers) with Boron Nitride. The cost benefits of chemical foaming vis-à-vis gas foaming of fluoropolymers (such as perfluoropolymers) enable standard high temperature extruders to run foam fluoropolymers (such as perfluoropolymers) without the need to port the barrel with a highly sophisticated gas valve, as well as the design and use of a specialized compression screw. The use of talc as a nucleating agent also works effectively or as a partial or complete replacement for Boron Nitride.
An added benefit of using talc which is either alkali or base is that it neutralizes the acidity of hydrogen fluoride (HF) which may evolve during extrusion. HF is highly acidic and causes corrosion in extrusion barrels, screws and extrusion head, tools and dies. Traditional metals or non-Hasteloy or Inconel surfaces cannot be used to extrude fluoropolymers (such as perfluoropolymers) under normal process conditions and the use of talc significantly reduces the acidity of the HF, thus mitigating corrosive wear on standard extrusion equipment.
The introduction of talc has the benefit of being an acid (HF) scavenger when compounded into pellets prior to extrusion and acts as both a nucleating as well as a foaming agent. Furthermore, when enhanced with the addition of a pelletized fluoropolymers (such as perfluoropolymers) with MgCO 3 and CaCO 3 and AClyn® wax (a registered trademarked wax provided by Honeywell) fluoropolymers (such as perfluoropolymers) foaming levels are further enhanced. This foaming agent of magnesium carbonate and calcium carbonate may be added as a separate pellet in a tumble blended mix or compounded together in a single homogenous pellet of talc (MgSiOH) and MgCO 3 /CaCO 3 /AClyn wax. The single homogenous pellet can then be extruded for communication cables, conductor separators, cable support-separators, wire insulation, jacketing, wraps, tapes, conduit tubes or any combination of said communications cables, conductor separators, cable support-separators, wire insulation, or fillers in a very simplistic chemically foamed extrusion process for fluoropolymers (such as perfluoropolymers). The foaming rate from 15 percent to 50 percent can be raised or lowered based on the percentage of each constituent used as well as by adjustments in extrusion temperatures, and screw design.
The present disclosure provides for the use of fluoropolymers and/or perfluoropolymers in any amount and in any combination. The family of fluoropolymers (such as perfluoropolymers) wherein these compounded nucleating and foaming agents may be used is at least the following:
The fluoropolymers that are characterized here are the melt processable materials for which this disclosure is focused:
1. MFA (Polytetrafluoroethylene-Perfluoromethylvinylether)
2. FEP (Fluorinated Ethylene Propylene)
3. PFA (Perfluoroalkoxy)
4. PTFE (Polytetrafluoroethylene
5. ETFE (Ethylene tetrafluoroethylene or (poly(ethylene-co-tetrafluoroethylene))
6. ECTFE (Ethylene chlorotrifluoroethlyene)
7. PVDF (Polyvinylidene Fluoride)
The perfluoropolymers that are characterized here are the melt processable materials for which this disclosure is focused:
1. FEP (Fluorinated Ethylene Propylene)
2. PFA (Perfluoroalkoxy)
3. MFA (Polytetrafluoroethylene-Perfluoromethylvinylether)
4. PTFE (Polytetrafluoroethylene)
It should be emphasized that the use of talc may be independent of the use of MgCO 3 /CaCO 3 /AClyn wax or talc may be used in any combination with MgCO 3 /CaCO 3 /AClyn wax to produce the desired foamed compositions.
The perfluoropolymers described are fluoropolymer resins that can be used and include copolymers of TFE with one or more copolymerizable monomers chosen from perfluoroolefins having 3-8 carbon atoms and perfluoro (alkyl vinyl ethers) (PAVE) in which the linear or branched alkyl group contains 1-5 carbon atoms. Preferred perfluoropolymers include copolymers of TFE with at least one hexafluoropropylene (HFP) unit and one PAVE (unit). Preferred comonomers include PAVE in which the alkyl group contains 1-3 carbon atoms, especially 2-3 carbon atoms, i.e. perfluoro (ethyl vinyl ether) (PEVE) and perfluoro (propyl vinyl ether) (PPVE). Additional fluoropolymers that can be used include copolymers of ethylene with TFE, optionally including minor amounts of one or more modifying comonomer such as perfluorobutyl ethylene. Representative fluoropolymers are described, for example, in ASTM Standard Specifications D-2116, D-3159, and D-3307. Such fluoropolymers are non-functional fluoropolymers if they have essentially no functional groups, but are functionalized fluoropolymers if functional groups are added, e.g., by grafting. Alternatively or additionally, preferred fluoropolymers are non-elastomeric, as opposed to elastomeric.
Functionalized fluoropolymers include fluoropolymers such as those described in the foregoing paragraph and additionally containing copolymerized units derived from functional monomers. If the concentration of functional monomer is high enough in a TFE copolymer, however, no other comonomer may be needed. Usually, but not necessarily, the functional groups introduced by such monomers are at the ends of pendant side groups. Functional monomers that introduce pendant side groups having such functionality can have the general formula CYZ wherein Y is H or F and Z contains a functional group. Preferably, each Y is F and —Z is —Rf —X, wherein Rf is a fluorinated diradical and X is a functional group that may contain CH2 groups. Preferably, Rf is a linear or branched perfluoroalkoxy having 2-20 carbon atoms, so that the functional comonomer is a fluorinated vinyl ether. Examples of such fluorovinylethers include CF 2 CF[OCF 2 CF(CF 3 )]m —O—(CF 2 )n CH 2 OH as disclosed in U.S. Pat. No. 4,982,009 and the alcoholic ester CF 2 —CF[OCF 2 CF(CF 3 )]m —O—(CF 2 )n —(CH 2 )p —O—COR as disclosed in U.S. Pat. No. 5,310,838. Additional fluorovinylethers include CF 2 CF[OCF 2 CF(CF 3 )]m O(CF 2 )n COOH and its carboxylic ester CF 2 CF[OCF 2 CF(CF 3 )]m O(CF 2 )n COOR disclosed in U.S. Pat. No. 4,138,426. In these formulae, m=0-3, n=1-4, p=1-2 and R is methyl or ethyl. Preferred fluorovinylethers include CF 2 CF—O—CF 2 CF 2 —SO 2 F; CF 2 CF[OCF 2 CF(CF 3 )]O(CF 2 ) 2 —Y wherein —Y is —SO 2 F, —CN, or —COOH; and CF 2 .CF[OCF 2 CF(CF 3 )]O(CF 2 ) 2 —CH 2 —Z wherein —Z is —OH, —OCN, —O—(CO)—NH 2 , or —OP(O)(OH) 2 . These fluorovinylethers are preferred because of their ability to incorporate into the polymer backbone and their ability to incorporate functionality into the resultant copolymer.
In one embodiment, a foamable composition can include at least one fluoropolymer and a chemical agent capable of functioning as both a nucleating agent and a foaming agent. In this embodiment, the chemical agent constitutes the only foaming agent present in the foamable composition. For example, the chemical agent can include talc or any talc derivative. In another example, the chemical agent can consist essentially of talc or any talc derivative.
In some embodiments, the chemical agent can be present in a concentration range of up to about 50 percent by weight of said foamable composition. In other embodiments, the chemical agent can comprise about 7.5 percent by weight of said foamable composition.
The chemical agent, such as talc or any talc derivative, can be capable of functioning as both a nucleating agent and a foaming agent upon extrusion of said foamable composition at a temperature greater than about 525 degrees F. In some embodiments, the chemical agent can be capable of functioning as both a nucleating agent and a foaming agent of the foamable composition. The chemical agent can also allow for processing of the foamable composition at a temperature of up to about 30 degrees F. below conventional temperatures normally required during extrusion of conventional foamable compositions having the at least one fluoropolymer. For example, the chemical agent can act as a processing aid to reduce or eliminate melt fracture during processing of said foamable composition.
In another embodiment, a foaming composition can include at least one fluoropolymer in a molten state at an elevated temperature and a chemical agent dispersed in the molten fluoropolymer. The chemical agent can be capable of functioning as both a nucleating agent and a foaming agent and can constitute the only foaming agent present in the foaming composition. For example, the elevated temperature of the molten state of the fluoropolymer can be sufficient to cause the at least one chemical agent to foam. In other embodiments, the elevated temperature can be, for example, any temperature in which the fluoropolymer is in a molten state, for example, the elevated temperature can be greater than 340 degrees F., such as about 570 degrees F. to about 600 degrees F. In some embodiments, e.g., for lower melting fluoropolymers, the elevated temperature can be in the range of about 430 degrees F. to about 530 degrees F. In other embodiments, the elevated temperature can be in a range of about 490 degrees F. to about 530 degrees F.
Methods of manufacturing a foamable composition are also provided. In one embodiment a method includes forming a mixture comprising a blend of a chemical agent capable of functioning as both a nucleating agent and a foaming agent and at least one base fluoropolymer using thermal and mechanical energy at a processing temperature below a temperature at which foaming of the mixture occurs, and processing the mixture to form a foamable composition. In some embodiments, the chemical agent can constitute the only foaming agent present in the mixture. In some embodiments, the foamable composition can be further processed to form a foamed article.
In one embodiment, the foamable composition comprises at least one fluoropolymer, at least one magnesium silicate compound, and a foaming agent; where the foaming agent is present in a concentration range of about 0.1 percent to about 10 percent by weight of the foamable composition.
One embodiment is the use of talc at 7 percent by weight combined with 93 percent neat resin (fluoropolymer or perfluoropolymer). In the present application talc is referred to as both a chemical agent and a foaming agent and the terms have been used interchangeably.
One embodiment is that foaming in a composition will occur with the use of talc at 10 percent by weight with 90 percent by weight of the neat resin.
In a particular embodiment, at least one magnesium silicate compound includes talc or any talc derivative.
In a particular embodiment, at least one magnesium silicate compound comprises at least one hydrated magnesium silicate compound.
In one embodiment, at least one magnesium silicate compound is present in a concentration range of up to about 50 percent by weight of the foamable composition.
In a particular embodiment, at least one magnesium silicate compound comprises about 7.5 percent by weight the foamable compound.
In a particular embodiment, at least one magnesium silicate compound comprises about 6 percent by weight of the foamable composition and the foaming agent comprising of magnesium carbonate and calcium carbonate combined comprises about 0.4 percent by weight the foamable composition.
In a particular embodiment, magnesium carbonate comprises about 0.3 percent to about 3 percent by weight the foamable composition and the calcium carbonate comprises about 0.1 to about 1 percent by weight of the foamable composition.
In a particular embodiment, at least one magnesium silicate compound comprises about 6 percent by weight the foamable composition and the magnesium carbonate comprises about 1 percent by weight of the foamable composition.
In a particular embodiment, at least one magnesium silicate compound comprises a sufficient weight percentage of the magnesium silicate compound that together with a sufficient weight percentage of only calcium carbonate forms the foamable composition.
In one embodiment the foamable composition is in the form of one or more pellets and the pellets are capable of being processed to form a foamed article.
In one embodiment the foamable composition is capable of being combined with an additional of at least one fluoropolymer and the combination is capable of being processed to form a foamed article.
In a preferred embodiment the foamable composition comprises at least one fluoropolymer, talc and any talc derivative, and an additional foaming agent where the foaming agent is present in a concentration range of about 0.1 percent to about 10 percent by weight of the foamable composition.
In a preferred embodiment the foaming composition comprises at least one fluoropolymer in a molten state at an elevated temperature, at least one magnesium silicate compound dispersed in the molten fluoropolymer, and a foaming agent dispersed in the molten fluoropolymer; where the elevated temperature is sufficient to activate the foaming agent and where the foaming agent is present in a concentration range of about 0.1 percent to about 10 percent by weight of the foaming composition.
In a particular embodiment, the elevated temperature to activate the foaming agent is greater than 525 degrees F.
In one embodiment the chemical agent is capable of functioning as both a nucleating agent and a foaming agent of the foaming composition and where the chemical agent allows for processing at a temperature of up to 30 degrees F. below the conventional temperatures normally required during extrusion of the foaming composition.
Another added benefit of using talc is that it neutralizes the acidity of hydrogen fluoride (HF) which may evolve during extrusion. HF is highly acidic and causes corrosion in extrusion barrels, screws and extrusion head, tools and dies. Traditional metals or non-Hasteloy or Inconel surfaces cannot be used to extrude perfluoropolymers under normal process conditions and the use of talc significantly reduces the acidity of the HF, thus mitigating corrosive wear on standard extrusion equipment.
In one embodiment the conventional temperatures are near or above the melting point of at least one fluoropolymer and where the chemical agent acts as a processing aid to reduce or eliminate melt fracture during processing of at least one fluoropolymer.
Pellets of the compounds described above can be created at 430-660 degrees F. and under certain conditions as low as 340 degrees F. within the extruder barrel.
One embodiment of the present application includes a first composition comprising a foaming agent comprising fluoropolymers (such as perfluoropolymers), plus talc or other talc derivative (which may include H 2 Mg 3 (SiO 3 ) 4 ; Mg 3 S 4 O 10 (OH) 2 ; 3MgO+4SiO 2 +H 2 O; MgOH+H 2 O+SiOH) which is blended, melted and extruded into a solid pelletized form for extrusion that allows for blowing or foaming with or without gas injection and with or without another chemical foaming agent.
A specific embodiment includes mixtures of a foaming agent comprising perfluoropolymer pellets (85 percent) and talc (15 percent) which is compounded together via heating to a selected melting point and extruded into a pelletized form, tumble blended in pelletized form for subsequent extrusion such that the pellets are placed in an extruder, heated to a selected melting point allowing for manufacture of blown or foamed insulative components.
An additional composition may be used exclusively as a foaming agent with nucleating capabilities in a tumbled blend of 30 percent foaming agent and 70 percent perfluoropolymer pellets.
An additional embodiment includes the composition comprising a singular perfluoropolymer or a mixture of different perfluoropolymers or recycled perfluoropolymers wherein the recycled perfluoropolymers comprise from 1-100 percent of the perfluoropolymers.
In another embodiment of the composition, additional nucleating agent may be used in combination with the talc in an amount from 1 percent to 10 percent by weight.
In another embodiment the composition comprises talc in an amount from 2 percent-20 percent by weight.
Another embodiment includes the talc of the composition, during blowing or foaming, reacting synergistically with another composition to form smaller, more uniform cell structures in the foamed or blown other composition.
Additionally an embodiment is where the composition comprises 100 percent non-recycled talc powder combined with 100 percent non-recycled perfluoropolymer wherein the ratio of talc to perfluoropolymer is 0.5 percent-20 percent by weight.
In another embodiment the talc and/or the fluoropolymers (such as perfluoropolymers) may be recycled or virgin.
Another embodiment includes the extruded fourth composition comprising a foamed or blown cell structure wherein the cell structures are consistent and as small as 0.0005 inches to 0.003 inches with an average size of 0.0008 inches.
In another embodiment the foamed cells have a open and closed cell structure.
In another embodiment the composition comprises talc in an amount from 0.5 percent-20 percent by weight wherein the talc and/or fluoropolymers (such as perfluoropolymers) may be recycled materials.
Another added benefit of using talc is that it neutralizes the acidity of hydrogen fluoride (HF) which may evolve during extrusion. HF is highly acidic and causes corrosion in extrusion barrels, screws and extrusion head, tools and dies. Traditional metals or non-Hasteloy or Inconel surfaces cannot be used to extrude perfluoropolymers under normal process conditions and the use of talc significantly reduces the acidity of the HF, thus mitigating corrosive wear on standard extrusion equipment.
In another embodiment the composition comprises inorganic or organic salt(s) and fluoropolymers (such as perfluoropolymers).
In another embodiment the cellular insulation is 100 percent recyclable.
Another embodiment is that the composition may comprise either inorganic or organic additives or both that includes inorganic salts, metallic oxides, silica and silicon oxides as well as substituted and unsubstituted fullerenes.
Also in an embodiment the composition is capable of meeting specific flammability and smoke generation requirements as defined by UL 910, UL 2424, NFPA 262, 259, 255, and EN 50266-2-x, class B test specifications.
Another embodiment includes the use of a twin-screw extruder for melting, blending and pelletizing the composition. In more detail, the compounding process utilizes a two-step system to insure the foaming components are thoroughly distributed and dispersed in the base polymer of the final compound. The first step requires a masterbatch blend be made of the foaming agents. The foaming agents are in a fine powder form and a high intensity blender, (i.e. Henschel type) is used to prepare the powder blend according to the specified formulation. A certain amount of resin, also in powder form, can be used in the first blending step as a mechanism to predisperse the foaming agents and aid in the second extrusion compounding step. The second stage of the compound preparation process utilizes a twin screw extrusion compounding system to incorporate the foaming agent masterbatch blend with the base resin. The design of the compounding screw is such that there is sufficient heat and mechanical energy to fully thermally melt the base polymer and incorporate the masterbatch blend with proper distribution and dispersion during mixing for homogeneity, but yet mild enough to keep the processing temperature of the compound below that in which foaming may be prematurely initiated. The final compound can be strand extruded and pelletized or alternatively an underwater pelletizing technique may be used (in other words air or water cooling is acceptable).
In one embodiment the method of manufacturing a foamable composition comprises forming a mixture comprising of a blend of a magnesium silicate compound, a foaming agent and, at least one base fluoropolymer using thermal and mechanical energy at a processing temperature below a temperature at which foaming of the mixture occurs; where the foaming agent is present in a concentration range of about 0.1 percent to about 10 percent by weight of the mixture and; then processing the mixture to form a foamable composition.
In a particular embodiment, the method of further comprising pelletizing the extrudate to form a plurality of foamable pellets.
In a particular embodiment, the method where the processing of the mixture results in one or more foamable pellets having a solid phase such that the foamable pellets are capable of being processed to form a foamed article.
In a particular embodiment, the method where the foamable composition is produced at a temperature low enough to prevent the foamable composition from foaming.
In a particular embodiment, the method where the temperature is sufficiently low so as to thermally constrain the foamable composition from foaming.
In a particular embodiment, the method where processing the foamable composition comprises applying energy to the foamable composition.
In a particular embodiment, the method where applying the energy can be any of heat, pressure, or a combination of heat and pressure.
In a particular embodiment, the method where processing the foamable composition comprises melt processing.
In a particular embodiment, the method where foamable compositions is in a solid state or a molten state.
In one embodiment, a method for manufacturing a foamed article comprises providing a foamable composition including at least one fluoropolymer, at least one magnesium silicate compound and, a foaming agent, where the foaming agent is present in a concentration range of about 0.1 percent to about 10 percent by weight of the foamable composition and, extruding the foamable composition to form a foamed article.
In a particular embodiment, the method where the foamed article comprises communications cables, conductor separators, cable support-separators, wire insulation, jacketing, wraps, tapes, conduit tubes, or any combination of the communications cables, conductor separators, cable support-separators, wire insulation.
Another embodiment is a method and system for heating the talc powder and a selected pelletized fluoropolymer (such as perfluoropolymer) creating a melt blendable composition, extruding the molten composition, cooling the molten composition and forming the solid composition into a pelletized nucleating and foaming agent.
Another embodiment includes a communications cables, conductor separators, conductor/cable support-separators, jacketing, tapes, wraps, wire insulations, conduit tubes, or any combination of the communications cables, conductor separators, cable support-separators, wire insulation individually comprising the same blown or foamed composition or may utilize the composition that includes selected fluoropolymers (such as perfluoropolymers).
Another embodiment of the disclosure includes the use of a foamed core and/or the use of a hollow center of the core, which in both cases significantly reduces the material required along the length of the finished cable. The effect of foaming and/or producing a support-separator with a hollow center portion should result in improved flammability of the overall cable by reducing the amount of material available as fuel for the UL 910 test, improved electrical properties for the individual non-optical conductors, and reduction of weight of the overall cable.
A method and system wherein the blown and/or foamed perfluoropolymer composition, cable, support-separator, conduit tube, insulation, jacketing, wrapping and/or taping line speeds are at or about 75 to 1500 ft/min.
Additional benefits of the embodiments include reduction of the overall material mass required for conventional spacers, insulation and jacketing which contributes to flame and smoke reduction.
Another embodiment of the disclosure includes the using this foam process, with either chemical or gas foaming, and placing the foam skin with both being the same materials e.g. (Perfluoropolymers) in a coextrusion or a second extrusion of a thermoplastic non-fluoropolymer as a skin or encapsulated by a layer of foam or solid perfluoropolymer skin as an insulation, cable filler or jacket.
In an embodiment of the present disclosure it has been found that talc, generally known as a nucleating agent in foamed plastics, exhibits blowing agent properties without the presence of a blowing agent.
Another embodiment combines talc, as a blowing agent, with resin(s) in the absence of any additional chemical blowing agent wherein the talc comprises 2-50 percent by weight of the resin and wherein the resulting composition is extruded into an extrudate product.
In another embodiment the talc is combined with a resin as a masterbatch in a percentage of up to 15 percent talc by weight to resin and extruded as a pellet.
In another embodiment the talc is combined with a recycled resin as a masterbatch in a percentage of up to 20 percent talc by weight to recycled resin and extruded as a pellet.
In another embodiment the resin(s) may be perfluoropolymers as a subset of fluoropolymers FEP, MFA, PFA perfluoropolymers or semicrystalline fluoropolymers ECTFE, ETFE, PVDF, and PTFE, etc. as pure resin, recycled resin, as a single resin or in combination with other resins.
In yet another embodiment the extrudate is a pellet, insulation, jacketing, wire insulation.
In another embodiment the compounding pellet that is processed as an extrudate is sufficiently low temperature so that the fluoropolymer resin(s) are thermally constrained from foaming and subsequently extruded into jackets, separators, insulation, etc.
In another embodiment the pellets are extruded at a sufficiently high temperature so that the resin is receptive to the talc blowing agent wherein the product is a foamed article.
In another embodiment the pellets may optionally include a color concentrate.
Another object of the disclosure is a foamed insulation comprising said composition.
Still an object of the invention is a process for manufacturing the composition.
Still another object of the disclosure is a process for manufacturing foamed insulation from the composition.
Other objects of the disclosure include recycled or waste materials to form these compositions (pelletized or otherwise), which can be processed and tumble blended with or without virgin or bare fluoropolymers (such as perfluoropolymers) to obtain acceptable foamable compositions after heating and extrusion.
Additionally it is known that foamed or blown articles or foamed composition produced with a gas blowing agent can be used in combination with talc leading to an increase in the percentage of cellular structure within a foamed or foamable composition when the combination of talc and either a chemical or gas blowing agent is used. This works with the use of pellets that incorporate talc and where these pellets have been formed when talc and fluorinated polymers form pelletized extrudate. The pelletized extrudate (pellets) are then subsequently heated via extrusion, molding, etc. to form the foamed, blown or cellular articles of matter. These pellets are known as “foamable” pellets or foamable fluoropolymer compositions that may incorporate perfluoropolymers.
Additionally the pellets are suitable for foaming or blowing such that when the pellets are combined with additional one or more selected fluoropolymer (such as perfluoropolymers) in an amount of 7 weight percent to 70 weight percent of the pellets to form an extrudate that is a foamed cellular insulation article.
Another embodiment is a method for manufacturing foamed or blown perfluoropolymer cellular insulation compositions wherein a second composition is a blowing or foaming agent comprising 20 weight percent of the first composition and 80 weight percent of the selected one or more perfluoropolymers heated to an appropriate melting point with homogeneously blending, extruding, cooling and forming into pellets using chemical or gas injection methods.
Another embodiment is an extrusion process wherein extrusion of a composition capable of forming cellular foam is extruded in an extruder wherein the extruder is specifically designed to minimize mechanical shear and increased heating mitigating premature foaming during the process of melting, blending, extruding and pelletizing said composition as well as mitigating corrosion of the extruder barrel due to passivation of acid and acidic gases provided by the use of talc with the fluoropolymers (such as perfluoropolymers) during the extrusion process.
An additional embodiment is the perfluoropolymer compositions having been added into an extruded melt of a base perfluoropolymer resin, in sequential steps, sufficient talc to accomplish a loading of talc in a range of 0.5 to 20 percent in combination with perfluoropolymer resin forming compound pellets, wherein the compositions may be used for subsequent heat extrusion or molding processes and provide cellular or foamed or blown fluoropolymer (such as perfluoropolymer) end products.
In another embodiment the compounded pellets comprise 7.5 weight percent talc and 92.5 weight percent perfluoropolymer resin.
The perfluoropolymer compositions may be extruded or molded into desired shapes and geometries without pelletizing, wherein the talc is acting as a chemical blowing agent and may also act as a nucleating agent, a foaming agent or both during extrusion or molding.
The foamed cellular insulation article reduces the quantity of combustible materials by 30 to 60 percent based on the extent of the foaming process, wherein the foamed cellular insulation article is achieved with or without a chemical blowing agent or gas blowing agent.
Another embodiment is a method of making a communications cable having flame retardant properties comprising the steps of; mixing the pellet(s) at a temperature of at most 600 degrees F. to ensure reaching the melting point of the fluoropolymer and melt processing the cable compositions at predetermined temperatures exceeding 525 degrees F. to ensure reaching the required temperature of the blowing agent, extruding a metered amount of a melted composition around an advancing electrical conductor and allowing the composition to foam and expand to produce an insulated conductor with a chemically blown perfluoropolymer insulation.
The pellets comprise 7.5 weight percent of said talc and 92.5 weight percent of the fluoropolymer (such as perfluoropolymer).
The pellets comprise from 2 to 30 weight percent of said talc and 98 to 70 weight percent of the fluoropolymer (such as perfluoropolymer).
The talc or talc derivative is a chemical composition of a magnesium hydrosilicate represented by the formula; 3MgOSiO 2 H 2 O, wherein SiO 2 is 63.5 percent weight, MgO is 31.90 percent weight and H 2 O is 4.75 percent weight and optionally includes other minerals including magnesite, chlorite, calcite, magnetite, carbonate, and dolomite.
The pellets are chemically foamed or blown via an extrusion process, a molding process or any known process requiring heat and/or pressure to achieve a commercially viable cellular product(s).
The cellular product(s) include FEP, PFA and MFA, PTFE, ETFE, ECTFE or PVDF the resulting foamed extrudate of which comply with fire and smoke and sheathing requirements for LAN which may include electrical and/or optical fiber conductors within the cable.
Included as an embodiment in the present application is a foamable composition, comprising;
at least one fluoropolymer, and; a chemical agent capable of functioning as both a nucleating agent and a foaming agent; wherein the chemical agent constitutes the only foaming agent present in the foamable composition.
An additional embodiment wherein the chemical agent is capable of functioning as both a nucleating agent and a foaming agent of the foamable composition and wherein the chemical agent allows for processing the foamable composition at a temperature of up to about 30 degrees F. below conventional temperatures normally required during extrusion of conventional foamable compositions having at least one fluoropolymer.
A further embodiment includes a foamable composition capable of being combined with an additional one or more fluoropolymers and the combination is capable of being processed to form a foamed article.
An additional embodiment includes a foamable composition comprising; at least one fluoropolymer, and; a foaming composition consisting essentially of one or more magnesium silicate compounds.
A further embodiment includes a foaming composition comprising: at least one fluoropolymer in a molten state at an elevated temperature, and; a chemical agent dispersed in the molten fluoropolymer, the chemical agent capable of functioning as both a nucleating agent and a foaming agent; wherein the chemical agent constitutes the only foaming agent present in the foaming composition and wherein the elevated temperature is sufficient to cause said at least one chemical agent to foam.
A further embodiment includes an additional method of manufacturing a foamable composition is included herein comprising: forming a mixture comprising a blend of a chemical agent capable of functioning as both a nucleating agent and a foaming agent, and; at least one base fluoropolymer using thermal and mechanical energy at a processing temperature below a temperature at which foaming of the mixture occurs wherein the chemical agent constitutes the only foaming agent present in the mixture, and processing the mixture to form a foamable composition.
As additional embodiment, included is the method for manufacturing foamable perfluoropolymer cellular insulation compositions, wherein one composition includes up to 20 weight percent of a blowing or foaming agent and a second composition comprises up to 80 weight percent of one or more selected perfluoropolymers heated to a melting point to assure homogeneous blending, extruding, and cooling forming pellets that together with chemical or gas injection methods provide foamed articles.
Additionally, the method for manufacturing foamable fluoropolymer compositions include using organic or inorganic salt(s) together with one or more selected perfluoropolymers.
In a further embodiment, pellets are formed such that magnesium carbonate, calcium carbonate, or both magnesium carbonate and calcium carbonate are added into forming a separate pellet in a tumble blended mix or compounded together into a single homogenous pellet of talc and a blend of magnesium carbonate, calcium carbonate and Aclyn wax.
The same pellets may also include in their composition a color concentrate.
Additionally, another embodiment the insulation can be used for metal or optical conductors including insulation forming a separator comprising; an inner core of a non-fluoropolymer or fluoropolymer and an outer layer covering the core comprising a foamed or foamed skinned perfluoropolymer wherein a cellular foaming extrusion process is performed using a single or dual head extruder and wherein the cellular foam is formed by chemical means, gas injection means or both chemical and gas injection means.
In an additional embodiment includes an extrusion process wherein extrusion of a composition capable of forming a cellular foamed article is extruded in an extruder wherein the extruder is specifically designed to minimize mechanical shear and increase heating thereby mitigating premature foaming during the process of melting, blending, extruding, and pelletizing the composition as well as mitigating corrosion of the extruder barrel due to passivation of acid and acidic gases evolving from the use of talc together with the perfluoropolymers and fluoropolymers during the extrusion process.
A further embodiment includes fluoropolymer compositions comprising; adding into an extruded melt of a base fluoropolymer resin, in sequential steps, sufficient talc to accomplish a loading of talc in a range of 0.5 to 20 percent in combination with fluoropolymer resin to form pellets wherein the pellets are used for subsequent extrusion or molding processes providing cellular, foamed, or blown fluoropolymer end products.
An additional embodiment includes compositions that are extruded or molded into desired shapes and geometries without requiring pelletizing, wherein the talc acts as a chemical blowing agent and may also act as a nucleating agent, a foaming agent, or both a nucleating and foaming agent during extrusion or molding processes.
The embodiment above wherein the talc neutralizes the acidity of hydrogen fluoride and provides for lubricating and mitigating corrosion in extrusion barrels, screws, extrusion heads, tools and dies.
A further embodiment includes the use of talc significantly reduces the acidity of hydrogen fluoride during extrusion of the perfluoropolymer compositions.
An additional embodiment includes foamed cellular insulation articles that reduce the quantity of combustible materials by 30 to 60 percent based on the extent of the foaming process and wherein cellular foamed insulation articles are achieved with or without a chemical blowing agent or gas blowing agent.
The embodiment above wherein gas blowing agents are used in combination with talc leading to an increase in the percentage of cellular structure within the cellular foamed insulation article.
Another embodiment includes a method of making a communications cable having flame retardant properties comprising the steps of;
mixing the pellet(s) of the present application (any of those described or contemplated) at a temperature of at most 600° F. to ensure reaching the melting point of the polymer and melt processing the composition at a predetermined temperature exceeding 525° F. to ensure reaching the required temperature for the blowing agent, extruding a metered amount of a melted composition around an advancing electrical conductor and allowing the composition to foam and expand to produce an insulated conductor with a chemically blown perfluoropolymer insulation.
The embodiment above includes pellets comprising perfluoropolymers or fluoropolymers and a blowing agent consisting essentially of talc or any talc derivative, wherein the talc or any talc derivative is a natural or synthetic hydrated magnesium silicate.
Further to the latest two embodiments above, the talc or any talc derivative may be a chemical composition comprising magnesium hydrosilicate represented by the formula; 3MgOSiO 2 H 2 O, wherein SiO 2 is 63.5 weight percent MgO is 31.90 weight percent and H 2 O is 4.75 weight percent and can also include other minerals comprising; magnesite, chlorite, calcite, magnetite, carbonate, and dolomite.
A further embodiment includes cellular product(s) using one or more of the following; FEP, PFA MFA, PVDF, ECTFE, ETFE, and PTFE, the resulting foamed extrudate of which comply with fire and smoke and sheathing requirements for electrical or fiber optic cable.
Cellular material formed by heating pellets having a perfluoropolymer and a blowing agent consisting primarily of talc, to a temperature above the melting temperature of the perfluoropolymer, and above the required temperature of the talc.
The cellular material is formed by heating the pellets during an extrusion process.
The disclosure includes and defines a cable utilizing the compositions described above.
DETAILED DESCRIPTION OF THE INVENTION
For the purpose of the present invention, the expressions “fluoropolymer” is intended to denote any polymer comprising recurring units (R), with more than 25 weight percent of recurring units (R) being derived from at least one ethylenically unsaturated monomer comprising at least one fluorine atom (hereinafter, fluorinated monomer).
The fluoropolymer comprises preferably more than 30 weight percent more preferably more than 40 percent weight of recurring units derived from the fluorinated monomer.
The fluorinated monomer can further comprise one or more other halogen atoms (Cl, Br, I). When the fluorinated monomer is free of a hydrogen atom, it is designated as per(halo)fluoromonomer. When the fluorinated monomer comprises at least one hydrogen atom, it is designated as hydrogen-containing fluorinated monomer.
Non limitative examples of fluorinated monomers are notably tetrafluoroethylene (TFE), vinylidene fluoride (VdF), chlorotrifluoroethylene (CTFE), and mixtures thereof.
Optionally, the fluoropolymer may comprise recurring units derived one first monomer, said monomer being a fluorinated monomer as above described, and at least one other monomer [comonomer (CM), hereinafter].
Hereinafter, the term comonomer (CM) should be intended to encompass both one comonomer and two or more comonomers.
The comonomer (CM) can notably be either hydrogenated (i.e. free of fluorine atom) [comonomer (HCM), hereinafter] or fluorinated (i.e. containing at least one fluorine atom) [comonomer (FCM), hereinafter].
Examples of suitable hydrogenated comonomers (HCM) are notably ethylene, propylene, vinyl monomers such as vinyl acetate, acrylic monomers, like methyl methacrylate, acrylic acid, methacrylic acid and hydroxyethyl acrylate, as well as styrene monomers, like styrene and p-methylstyrene.
In an embodiment of the invention, the polymer is a hydrogen-containing fluoropolymer. By “hydrogen-containing fluoropolymer” it is meant a fluoropolymer as above defined comprising recurring units derived from at least one hydrogen-containing monomer. A hydrogen-containing monomer may be the same monomer as the fluorinated monomer or can be a different monomer.
Thus, this definition encompasses notably copolymers of one or more per(halo)fluoromonomers (for instance tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, perfluoroalkylvinylethers, etc.) with one or more hydrogenated comonomer(s) (for instance ethylene, propylene, vinylethers, acrylic monomers, etc.), and/or homopolymers of hydrogen-containing fluorinated monomers (for instance vinylidene fluoride, trifluoroethylene, vinyl fluoride, etc.) and their copolymers with fluorinated and/or hydrogenated comonomers. The hydrogen-containing fluoropolymer are preferably chosen among:
TFE and/or CTFE copolymers with ethylene, propylene or isobutylene (preferably ethylene), with a molar ratio per(halo)fluoromonomer(s)/hydrogenated comonomer(s) of from 30:70 to 70:30, optionally containing one or more comonomers in amounts of from 0.1 to 30 percent by moles, based on the total amount of TFE and/or CTFE and hydrogenated comonomer(s) (see for instance U.S. Pat. No. 3,624,250 and U.S. Pat. No. 4,513,129); Vinylidene fluoride (VdF) polymers, optionally comprising reduced amounts, generally comprised between 0.1 and 15 percent by moles, of one or more fluorinated comonomer(s) (see for instance U.S. Pat. No. 4,524,194 and U.S. Pat. No. 4,739,024), and optionally further comprising one or more hydrogenated comonomer(s); and mixtures thereof.
As used here, a blowing agent comprising “primarily talc” achieves at least most of its blowing function from talc. In certain exemplary embodiments wherein the blowing agent comprises primarily talc, the blowing agent is at least 30 weight percent talc. That is, in such embodiments talc is at least 30 weight percent of all materials operative as a blowing agent in the composition in the intended extrusion or other forming operation. In certain exemplary embodiments the blowing agent is at least 10 weight percent talc. In certain exemplary embodiments the blowing agent is at least 20 weight percent talc. In certain exemplary embodiments the blowing agent consists essentially of talc. In certain exemplary embodiments talc is used in combination with other blowing agents, including, e.g., boron nitride and/or other known blowing agents as well as any of the derivatives of talc. Magnesium carbonate and calcium carbonate are additional chemical agents that may used in combination with talc or any of the derivatives of talc.
Working Compounding Example 1
A composition including talc (MgSiOH; 3MgO+4SiO2+H2O; MgOH+H2O+SiOH) or other talc/talc derivatives such as Mg3Si4O10(OH) 2 is sequentially added into the feeder section with base perfluoropolymer resin in a ratio of 15 percent-20 percent talc and 80 percent-85 percent perfluoropolymer resin. The extrusion of the base resin perfluoropolymer is pelletized into a single pellet. The temperature profile for zones 1 through 6 would be as follows: 520, 530, 540, 560, 580 and 600 degrees Fahrenheit. The process temperatures of this single compound pellet with 7.5 percent talc and 92.5 percent perfluoropolymer resin is kept to a minimum to ensure no premature foaming occurs during pellet formation. The pellets are then extruded on a 30 to 1 ratio high temperature extruder with temperature zones of 525, 535, 550, 580, 640 and 660 degrees Fahrenheit for the subsequent extrusion into profiles, insulations and jackets.
Working Insulation Extrusion Example 2
A foamed perfluoropolymer insulation was extruded over 24 gage wire by using a cross head with a tip and die. The extruder was a high temperature 1½ inch, 30:1 ratio device. The screw design was a 4:1 high compression screw. The line speeds were in a range from 400 ft/min. to 1500 ft/min. The screw rpm were from 12 rpm to 35 rpm with pressure ranging from 1500 psi to 2000 psi. The melt temperature was 678 degrees F. The extruder was loaded with pellets containing 10 percent talc and 90 percent FEP. This resulted in an insulation extrudate that was 41 percent foamed with an average foamed cell size of 0.0007 inches.
Working Profile Extrusion Example 3
A cross web cable support-separator was manufactured with a 1½ inch high temperature extruder using the following materials and conditions;
Use of a cross web die with a high compression screw, a line speed of 148 ft./min. at a pressure of 1700 psi with a 48 RPM screw speed and a melt temperature of 649 degrees F. The extruder was loaded with a pellet master batch, the pellet comprising 15 percent talc and 85 percent FEP. The pellet master batch was blended in a 50:50 ratio with 100 percent FEP. Therefore, the final blend ratio was 50 percent master batch pellets and 50 percent FEP. This resulted in a cross web extrudate that was 40 percent foamed with an average foamed cell size of 0.0006 inches.
Working Profile Extrusion Example 4
A Double Helix cable support-separator was manufactured using a 1½ inch extruder with the following materials and conditions;
A web cable support-separator was manufactured using a profile extrusion die with a high compression screw, a line speed of 75 ft./min. at a pressure of 1850 psi with a 40 RPM screw speed and a melt temperature of 646 F. The extruder was loaded with master batch pellets containing 15 percent talc and 85 percent FEP. This master batch was blended with 100 percent FEP. The final blend ratio was 70 percent master batch pellets and 30 percent FEP. This resulted in a web extrudate that was 33 percent foamed with an average foamed cell size of 0.0007 inches.
Working Insulation Extrusion Example 5
A foamed perfluoropolymer insulation was extruded over 24 gage wire by using a cross head with a tip and die. The extruder was a high temperature 1½ inch, 30:1 ratio device. The screw design was a 4:1 high compression screw. The line speeds were in a range from 300 ft/min. to 900 ft/min. The screw rpm were from 12 rpm to 30 rpm with pressure ranging from 1500 psi to 2000 psi. The melt temperature was 680 F. The extruder was loaded with pellets containing 10 percent talc and 90 percent FEP. This resulted in an insulation extrudate that was 35 percent foamed with an average foamed cell size of 0.0007 inches.
Other desired embodiments, results, and novel features of the present invention will become more apparent from the following drawings, detailed description of the drawings, and the accompanying claims.
DETAILED DESCRIPTIONS
The following description will further help to explain the inventive features of the system, method and composition of the present disclosure.
The composition is comprised of magnesium silicate hydroxide, commonly known as talc and perfluoropolymer. The ratio of talc is at or about 15 percent with the perfluoropolymer at or about 85 percent by weight, however the talc may range in concentration from 0.2 to 20 percent and up to 50%. The perfluoropolymer component of the composition may be MFA, FEP, PFA, or ETFE, as a selected, uniform, pure fluoropolymer (such as perfluoropolymer) or as a mixture of one or more different fluoropolymers (such as perfluoropolymers) or 100 percent recycled and/or blended with non-recycled perfluoropolymers in any ratio from 1 to 99 percent. The composition is then placed in an extruder specifically designed to minimize heat transfer such that foaming or nucleation is not prematurely initiated and such that the composition may be melted, blended, extruded and pelletized. Additionally, an organic or inorganic salt may be added to the pellet composition.
The composition may also comprise inorganic and/or organic additives that include inorganic salts, metallic oxides, silica and silicon oxides as well as substituted and unsubstituted fullerenes.
The pellet composition may then be blended with virgin or recycled fluorinated polymers, fluoropolymers (such as perfluoropolymers), extruded at a temperature higher than the foaming or nucleation temperature so that foaming and nucleation occur in the fluorinated polymers.
It will, of course, be appreciated that the system, method and compositions that have been described have been given simply by the way of illustration, and the disclosure is not limited to the precise embodiments described herein; various changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention as defined in the inventive claims. | The disclosure provides a composition as well as a set of compositions and method for producing cellular or foamed or blown fluoropolymers such as perfluoropolymers and other thermoplastics articles allowing for the creation of a lower cost communications cable, conductor separator, conductor support-separator, jacketing, tape, wire insulation and in some cases a conduit tube as individual components or combined configurations that exhibit improved electrical, flammability and optical properties. Specifically, the foamable or blown fluoropolymer such as a perfluoropolymer cellular insulation composition comprises; talc and the selected fluoropolymer such as perfluoropolymers. Compounded pellets or products resulting in cellular or foamable products using these pellets has also been realized by providing the melt combination in the pellets of only talc and a perfluoropolymer. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improvement in poles, markers and the like provided with a device for linking to the ground with breaking point, in particular anti-parking posts or vertical signalling markers used in road signalling.
2. Description of the Related Art
It is relatively expensive to replace markers and posts damaged further to a shock by a vehicle, insofar as not only must the damaged part be replaced, but it has to be unsealed and the replacement part sealed.
In the past, it has therefore been proposed to fix the signalling markers or posts with the aid of a ground-linking device comprising a breaking part, so that, in the event of shock by a vehicle, only the linking piece or one of its elements is deformed or broken. It follows that, in principle, only the linking piece and/or the corresponding element are to be replaced.
U.S. Pat. No. 3,340,531 in particular discloses such a linking device. This document provides fixing the pole to the ground via a sealed base having a hollow tube with the diameter of the pole, the link between this hollow tube and the pole being ensured by a linking piece which is placed, half in this hollow tube and half in the pole. This linking piece presents a median circumferential thin section intended to form the zone of deformation or of rupture. This linking piece may be pierced in its length so as to receive a sling intended to maintain the pole and the base together when the linking piece has broken. The major drawback of this device consists in the risk of damaging the opposite edges of the pole and the base. In effect, in the event of a considerable shock, bringing about complete rupture of the linking piece, the edges of the pole and of the base may violently strike one another or part of the linking piece.
U.S. Pat. No. 3,912,405 discloses another device of this type, comprising a linking piece of which a part is interposed between the pole and the tube sealed in the ground, having the same diameter as the latter but having a thinned rupture zone. Inside this linking piece there extends a flat iron element intended to maintain the sealed tube and pole together after rupture of the linking piece. The geometry of this flat iron element is not favourable to correct functioning of this device apart from a shock perpendicular to the plane of this piece.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved linking device fully performing its role while avoiding any damage of the pole and of the base.
Another object of the invention is to provide such a device which may be adapted to poles of different geometrical shapes.
A further object of the invention is to provide a device which may be used with a base not projecting above ground level.
Yet another object of the invention is to be able to propose such a device not having a part projecting with respect to the pole on inclined ground.
The present invention has for its object a pole, marker or the like formed by an anchoring post and a vertical member or upright, in particular a tube, the anchoring post and upright being linked together by a linking piece, preferably cylindrical, having a zone of lesser resistance to force. The assembly is arranged so that the opposite edges of the anchoring post and the upright have a space therebetween in which the zone of lesser resistance is provided. The linking piece, possibly having a central longitudinal bore, receives a sling or the like shaped to provide a link between the anchoring post and upright after rupture of the linking piece. The post and the upright each include a plate or block element, the two plates oppose one another and at least one has a surface sloping from its center towards its periphery such that the space between the two plates is greater at the periphery of the pole than at its center.
The linking piece is therefore centered on the median axis of the pole and of the anchoring post.
The linking device according to the invention, formed by the two plates and the linking piece, may be used for any street structure fixed to the ground by one or more uprights or poles. Without this being exhaustive, mention may be made of anti-parking posts or markers, barriers, benches, candelabra, signalling, in particular road-signalling masts, advertizing supports and panels, luminous markers, supports of all types, such as trashcan supports. The expression pole, marker or the like is therefore intended to cover all of the possibilities.
The inclined surface of the plate is preferably a surface of generally convex shape. Advantageously, the curvature or the angle of the inclined surface is chosen so that the linking piece breaks before contact between the plates. In any case, the curvature makes it possible to avoid any contact between the edges of the plates. Possible contacts will be made in resistant zones of the plates. In addition, the plates may advantageously be pieces which are solid or of thickness greater than the thickness of the poles, and therefore present a high resistance.
According to the invention, the plates may have an outer diameter identical to or different from that of the anchoring post or the upright which bear them. It will very advantageously be identical when plate and pole will be off-the-ground in order not to increase the dimensions and to avoid any projecting part. The plate or plates may be fixed definitively, for example by welding, or be made in one piece with the upright and/or the anchoring post, or be removably fixed by any means known per se.
According to a particularly advantageous modality, anchoring post and corresponding plate are removably fixed together and are arranged so as to be able to be placed below ground level or substantially at that level. A circular, preferably flat, supple joint is provided between the two plates, preferably on their periphery. This embodiment ensures a certain tightness and renders invisible the adaptation of the pole or marker while allowing the linking piece to be easily changed after a shock. The outer diameter of the joint is preferably larger than or equal to that of the upper plate or the upright, which advantageously makes it possible to preserve the seal and the plate in the event of rupture. In the event of rupture, the upper plate linked to the upright does not come into contact with the seal, but with the joint. The joints are preferably chosen to present a diameter greater than the diameter of the plates.
According to a particular embodiment, a supple, flat, circular joint is provided between the two plates and not projecting therebeyond, as well as a second circular joint coming into position on the periphery of the preceding one, this joint being shaped to be able to adapt itself substantially to the inclination of the ground. It may therefore be a question of a second flat joint, of a joint presenting an inclined surface or, preferably, of a flat joint cut into two parts along an inclined plane so that, in the case of horizontal or substantially horizontal ground, the joint is used in its flat form and, in the case of inclined ground, one of the two joints is turned through 180° so that the maximum thicknesses of the two joints coincide. In the latter case, a flat, unequally cut joint may be used, so as to propose to the user different possibilities from the same joint set, as a function of the inclination of the ground, the user being able simply to use one or the other of the two half-joints thus produced or the association of the two.
According to a preferred embodiment of the invention, particularly adapted to a location below ground level, the plate fixed to the anchoring post is formed by a first half-plate secured with the anchoring post and presenting a housing to receive, on the one hand, one end of the linking piece and, on the other hand, a second half-plate having the bore for the linking piece and means for removable fixation in the housing of the first half-plate, in that the linking piece presents the end (for example a flange) shaped to be positioned in the housing of the first half-plate and to be removably immobilized therein when the second half-plate is in place, and in that this half-plate preferably includes the inclined or convex surface. The removable link between the two half-plates may be produced by any known means, for example by means of screws or, better, of a bayonet or catch fixation system, preferably with a screw or like locking.
The anchoring post and corresponding plate may also be one and the same piece and includes means for fixation on a surface. This embodiment is adapted in particular, but not exclusively, for fixation on a vertical surface for the suspension of signs or signalling panels.
The linking piece preferably comprises a circular groove near at least one of its two ends and the plate comprises one or more bores intended to receive means, for example points or screws, inserted in the groove to maintain the linking piece in place, this groove further being separated from the outer surface of the linking piece by a zone of diameter which is constant or not, intermediate the diameter of the linking piece and that of the groove.
According to an advantageous modality of the invention, in its part intended to be fixed to the pole, marker or the like proper, the upper plate is arranged so as to be able to receive poles, markers or the like of different diameters. For example, two or more shoulders of different sections or diameters decreasing from the periphery of the plate may be provided to that end, each section or diameter being able to receive poles of corresponding section or diameter.
These shoulders may be inscribed in the same plane orthogonal to the median axis of the linking device or in different planes, preferably with the reduction of section or diameter being made in the direction opposite the location of the linking piece. The shoulders may be of any shape as a function of the geometrical shape of the pole, e.g. circular, oval, rectangular, square, etc. . .
The invention also relates to the linking device formed by the two plates and by the linking piece, as defined hereinbefore. This device generally comprises a linking piece including a zone of lesser resistance and two plates each including a central bore having an inner diameter slightly larger than the outer diameter of the linking piece. The two plates are adapted to be mounted on the linking piece and to face each other by opposite surfaces of which at least one is inclined, preferably of generally convex shape, the linking piece being designed to be able to be removably immobilized with respect to the two plates, so that, after immobilization of the three pieces with respect to one another, a space remains between the two surfaces, in which the zone of least resistance is located.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with the aid of embodiments given by way of non-limiting examples and with reference to the drawings, in which:
FIG. 1 shows a view in partial section of a pole according to the invention.
FIGS. 2 and 3 show in partial section two other embodiments provided so that the anchoring post and its plate can be placed below ground level.
FIG. 4 shows in section a plate according to a particular embodiment.
FIG. 5 is a view in partial section of another embodiment, and
FIG. 6 schematically shows a mode of adaptation to inclined ground and an upper plate with shoulders.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a signalling pole 1 comprising an anchoring post or base 2 sealed in the ground 3 and the pole 4 . Pole and anchoring post are formed from a cylindrical metal tube. FIG. 1 shows that the pole and the anchoring post each comprise a plate or block elements 5 , 6 respectively. Each plate is fitted in the pole or the corresponding post and fixed by a welding bead 7 , 8 respectively; Of course, other fixing means may be provided for the plates.
The opposite surfaces of the plates or blocks 5 and 6 are referenced 9 , 10 respectively. Surface 9 is plane while surface 10 presents a curvature so as to give surface 10 a generally convex form.
The two plates or blocks 5 and 6 include a central bore 11 of generally cylindrical shape, adapted to receive, tightly, a linking piece 12 having a circumferential groove 13 . When the linking piece is in place, it leaves a space 14 between the two surfaces 9 , 10 of the plates 5 , 6 , in which space the circumferential groove 13 is inscribed. It is clearly seen that the central bores 11 and the linking piece 12 are centered on the median axis of the post and the upright or pole proper.
In the vicinity of each of its two ends, the linking piece 12 has grooves 15 . Opposite these grooves, when the linking piece 12 is in place, each of the plates 5 and 6 has three threaded transverse bores 16 intended to receive threaded fasteners 17 of which the inner end engages in the groove to maintain the linking piece in place. It will be noted that groove 15 presents a complex form with a part intended to receive the point in position of fixation and a part 19 of diameter intermediate the outer diameter of the linking piece and the diameter of this groove, this part 19 being provided to allow easy dismantling, even in the case of shock of high intensity with risk of damage at the point of contact between point and groove.
The linking piece 12 comprises a longitudinal central orifice 20 receiving a sling or connection 21 , which may be a supple or more or less rigid sling, intended to maintain anchoring post and pole attached together after rupture of the linking piece. To that end, the ends of the sling are provided with stop pieces 22 with diameter greater than orifice 20 .
A rigid sling may be used, particularly for relatively high poles, designed to avoid the upright falling to the ground too quickly after rupture of the linking piece.
Reference numeral 23 designates a joint intended to obturate the space 14 for sealing and aesthetic purposes. It may be a joint made of plastics material or of a metallic joint.
Reference will now be made to FIG. 2 which shows an embodiment of the invention in which the rupture device is rendered invisible by the fact that it is located below ground level, this making it possible not to modify substantially the outer appearance of the pole. This is particularly interesting in the domain of anti-parking posts and in particular of markers or small posts performing, at the same time, a decorative role, made in particular of cast iron, stainless steel and presenting various shapes, namely of constant diameters or of irregular diameters, for example generally conical, triangular, or oval in shape.
The anchoring post 30 , sealed in the ground 3 , presents an inner thread 32 intended to cooperate with an outer thread 33 borne by the plate or block element 31 . A flat, circular joint 34 is provided between the plate and the anchoring post so as to ensure tightness with respect to the threading.
As in the preceding embodiment, the plate 31 or has block element three bores 16 intended to allow passage of the fastener points 17 intended for fixation of the linking piece 12 in the plate 31 . It will be noted that the access to the point of plate 31 can be effected only after screwing and withdrawal of the plate 31 with respect to the anchoring post 30 .
The anchoring post and the plate or block element 31 are placed in the ground so that the surface 35 of the plate 31 which, here, is a surface of generally convex shape, lies slightly below the level 3 a of the ground. It will be noted that, in this embodiment, when the linking piece 12 is in place, the edge 36 of the linking piece 12 which upwardly defines the circumferential groove or area of reduced dimension 13 , lies substantially at ground level.
The pole 37 is, here, directly manufactured with the plate or block element 38 . Here a pole of cast iron essentially hollow, but presenting an initially solid part in which a blank may be formed in the foundry, allowing the subsequent machining of the bores intended to receive the linking piece 12 and the end of the sling 21 , and bores intended to receive the points of three fasteners 17 .
The lower surface 40 of the plate 38 is, here, a plane surface. When the assembly is mounted, it will be noted that this surface 40 lies substantially at ground level, in the plane of the edge 36 . During assembly, there is interposed between surfaces 40 and 35 , a supple, flat, circular joint 41 which, in the event of a shock, can deform under the effect of the deformation of the linking piece 12 , which will avoid any damage of the seal.
FIG. 3 shows a variant embodiment of FIG. 2, in which the fixation of the lower plate is made differently.
This plate or block elements 42 presents a peripheral flange 43 having bores 44 coming opposite corresponding bores 47 , threaded and made in the anchoring post 45 . It will be understood that the plate 42 is fixed on the anchoring post by screws 46 .
Of course, other variants of fixation of the lower plate may be envisaged, such as the embodiment of a bayonet system.
FIG. 4 shows the preferred embodiment in the case of a link below ground level. The plate fixed to the anchoring post 52 is formed by a half-plate 53 welded to the post and presenting in its upper part a circular housing 54 intended to receive the other half-plate 55 . This half-plate 55 has a bore 56 adapted to receive a linking piece 57 . The half-plate 55 presents a curvature 58 going from the bore 57 to the periphery of the half-plate 55 . In the region of this curvature 58 , it further has bores 59 for the passage of screws 60 intended to fix the two half-plates 55 and 53 together by screwing in corresponding threaded holes 61 . The half-plate 53 a central bore 62 with, in its upper part, a part 63 of larger diameter. The linking piece 57 presents a flange 64 which, on being housed in part 63 , may be immobilized in place by the fixation of the half-plate 55 on the other 53 by screws 60 .
As in the embodiments of FIGS. 2 and 3, this assembly is sealed below ground level 65 . The seal 66 proper stops, upwardly, at the upper end of the half-plate 53 . This is symbolized by the broken line in FIG. 4 . Two circular joints 67 , 68 (or one single joint) are placed between this end and the surface 65 . It is seen that, as in FIGS. 2 and 3, the pole 69 will be in contact with this joint, which is deformable.
The space 70 between the surface 65 and the seal 55 is filled with an appropriate material such as stone, cement, asphalt, etc. . .
For the rest, the linking piece comprises, as before, the circumferential groove, the groove for the engagement of the fastener points for fixation to the pole and the longitudinal central bore with the sling.
An elastic means such as a spring 48 (FIG. 1) may be provided between the plate and the end of the linking piece, in order to facilitate withdrawal of the latter from its housing in the plate.
In the different embodiments, anchoring post and associated plate may have standard dimensions in order to be usable with poles and associated plates of various shapes and diameters.
Reference will now be made to FIG. 5, which shows a plate or block element 50 having presenting sealing flanges 51 allowing the plate 50 to be fixed on a vertical surface. Furthermore, the plate 50 presents the characteristics allowing it to accommodate a linking piece according to the invention. The plate 50 therefore performs the role, here, of anchoring post intended in particular for a mural signalling or for signs.
In any case, the linking device may be adapted for positioning on an inclined surface 80 (pavement, road), the pole with its upper plate or block element 81 remaining vertical (cf. FIG. 6 ). A set of 2 circular joints 82 , 83 may in particular be used. One, 82 , is of constant section and is placed in the space between the two plates 81 , 84 in which it is totally inscribed. The otherjoint 83 is a flat joint cut into two along an inclined plane 85 and giving two substantially equal parts. This joint 83 may be used in its flat form in the case of horizontal ground or, as shown in FIG. 6 (inclined ground), after turning one of the parts over through 180°, in its inclined form in order to follow the inclination of the ground.
In a variant, the inclined plane 85 may have two unequal parts, which allows a greater flexibility of use, the installer being able to place one or the other of the two parts of different inclinations or the two superposed, depending on the slope of the ground.
A specific set of joints 83 of different shapes may also be resorted to.
FIG. 6 also shows that, in its upper part, the upper plate 81 has two shoulders of different diameters enabling two diameters of pole to be accommodated.
Anchoring post, pole proper, plates, linking pieces may, of course, be made of different materials. The poles may generally be made of metal, such as iron, aluminium, cast iron, or of plastics material and even wood. The linking device according to the invention may be made of metal, particularly steel or brass, or of plastics material, particularly reinforced plastics material. The device according to the invention may of course be adapted to the different geometrical shapes that the poles may have in general. Similarly, the person skilled in the art may select the constituent materials as a function of the desired shock resistance. | A pole or the like formed by an anchoring member and a vertical member which are linked by a linking piece having a zone of lower resistance to force. Block members are provided at the opposite ends of the anchoring member and the vertical member each of which has a central bore for receiving the linking piece and at least one of the block members has a surface slopping from its center towards it periphery such that a space between the opposite block members is greater at the periphery of the pole than at its center. | 4 |
PRIORITY CLAIM
Not Applicable
CROSS-REFERENCE TO RELATED ARTICLES
[1] Cusack et al., “Automatic Load Contour Mapping for Microwave Power Transistors”, IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-22, No 12, December 1974, page 1146–1152
[2] Tsironis, U.S. patent application Ser. No. 09/592,983 “Adaptable Prematched tuners and method”
[3] Tsironis, U.S. patent application Ser. No. 10/326,543 “Microwave Tuners for wideband high reflection applications”
[4] Ishida et al., U.S. Pat. No. 5,079,507 “Automatic Microwave Impedance Adjusting Apparatus”
[5] Tsukii, Toshikazu, U.S. Pat. No. 4,535,307 “Microwave circuit device package”
[6] ATN Microwave Inc., “A Load Pull System with Harmonic Tuning”, Microwave Journal, March 1996.
[7] Tsironis, C. “Product Note #41: Computer Controlled Microwave Tuner, CCMT”, Focus Microwaves Inc., January 1998.
[8] Tsironis, C. “System Performs Active Load-Pull Measurements”, Microwaves & RF, November 1995, page 102–108.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to a manual or automatic microwave tuner to be used mainly in wideband automatic load pull testing of power transistors or noise testing of low noise transistors by being able to synthesize the amplitude and phase of selected impedances.
Modern design of high power microwave amplifiers and oscillators, used in various communication systems, requires accurate knowledge of the active device's (microwave transistor's) characteristics. In such circuits, it is necessary for the transistors to operate in their highly non-linear region, close to power saturation, and it is inadequate to be described as such using non-linear analytical or numerical models, in order to design power amplifier circuits.
A popular method for testing and characterizing microwave components (transistors) in the non-linear region of operation is “load pull”. Load pull is a measurement technique employing microwave tuners and other microwave test equipment. The microwave tuners are used in order to manipulate the microwave impedance (or reflection factor) conditions under which the Device Under Test (DUT, or transistor) is tested ( FIG. 1 ).
When transistors operate in the non-linear range at high power and close to saturation, signal distortion inside the transistors creates significant harmonic frequency signals that reduce the efficiency and the signal transmission purity of the communication system. In order to improve and optimize the performance of such transistors under these operating conditions, the tuners used to test those high power DUT must provide for very high reflection factors of typically 0.95 to 0.98, corresponding to very low internal impedances of the DUT of the order of 0.5 Ohm or less.
The tuners used in such automatic load pull set-ups must be able to be pre-characterized (calibrated) for different states and at desired frequencies, using a calibrated Vector Network Analyzer (VNA) and to be able to reproduce repeatably the calibrated states.
There are essentially two types of tuners which can be used to allow generation and manipulation of microwave impedances presented to the DUT:
A. Passive electro-mechanical [7] or passive electronic tuners [6], leading to “passive load pull” ( FIGS. 1 , 2 ); and;
B. Active tuners, leading to “active load pull” [8].
Electro-mechanical tuners [7] have a number of advantages compared to active tuners [8], such as long-term stability, higher handling of microwave power, much easier operation and lower cost.
Passive electronic tuners [7] have been used in the past, but they provide limited tuning range and handling power and do not offer any significant benefit within the scope of this invention.
DESCRIPTION OF PRIOR ART
Existing passive automatic tuners are typically electromechanical, and are used in set-ups shown in FIG. 1 .
Typical electromechanical tuners of this kind ( 7 ) use the principle of a sliding-screw ( FIG. 1 ), in which adjustable mechanical obstacles (probes, typically metallic) ( 1 ) are inserted into the transmission media of the tuners (slotted microwave airlines) ( 2 ) and create variable and controllable capacitances ( 11 ) as shown in FIG. 3 . This reflects part of the power coming out of the DUT and creates a “real” impedance generated at the tuner test port ( 4 ) presented to the DUT ( FIG. 1 ).
Probe control is made by means of a horizontal translation mechanism (lead screw) ( 3 ) and a vertical control mechanism (vertical axis) ( 6 ). By moving the probe up and down ( 5 ) we can control the amplitude of the reflection factor and by moving horizontally ( 8 ) we can control the phase of the reflection factor presented to the DUT at the tuner's ( 7 ) test port ( 4 ).
The various electro-mechanical slide-screw tuners differ in the form and function of their RF probes (slugs). FIG. 3 shows the cross section of the tuning area of such a wideband, slide-screw tuner. The metallic RF probe ( 9 ) is attached to a (not shown) vertical axis ( 14 ) and moves inside a slotted airline or parallel-plate airline (slabline) ( 10 , 13 ) in the middle of which is the center conductor ( 12 ). When the probe ( 9 ) moves closer to the center conductor ( 12 ), a variable, controllable, capacitive load is created in the air-gap ( 11 ). This change in capacitance permits to control the amplitude of the microwave reflection factor seen at the test port of the tuner ( 4 ) in FIG. 2 . When moving the probe parallel to the axis of the airline ( 2 ), the phase of the reflection factor is modified and thus any impedance on the Smith Chart ( FIG. 5 ) can be reached. The reflection factor generated by this form of RF probe (slug) is wideband, covering more than 1 octave and typically two to three octaves. Typical reflection factors of 0.8 to 0.9 can be reached using the ‘slide-screw’ tuners ( FIG. 14 ).
Higher reflection factors, than with single-probe slide screw tuners, can be reached using the ‘pre-matching’ tuner concept, which includes two independently adjustable probes ( 15 and 16 ), in two separate sections of the tuner ( 22 ). The sections are separated by a physical vertical wall ( 23 ) and the probes are driven by two independent lead screws ( 18 and 19 ) and vertical control mechanisms ( 20 and 21 ) and are inserted in the same slotted airline ( 17 ), as shown in FIG. 4 .
In this case ( FIG. 5 [2]), a prematching reflection factor (vector, 24 ) is added to the tuning reflection factor (vector, 25 ) and combined their reflection factors can reach values of up to 0.99 in a certain area of the Smith Chart.
An alternative method for obtaining high reflection factors (or Voltage Standing Wave Ratio, VSWR, which is the equivalent) ( FIG. 6 ) is the concept of using two probes ( 26 , 27 ), driven by two parallel lead screws ( 32 , 33 ), with a once adjusted horizontal distance ( 28 ) and simultaneous horizontal ( 29 , 30 ) and vertical ( 34 , 35 ) control of the distance between the probes and the central conductor of the slotted airline ( 31 ) [3]. This type of structure allows generating high reflection factors all over the Smith Chart, and not only in a certain area as the pre-matching tuners, similar to the grey area covered on the Smith Chart in FIG. 16 .
An older method that obtains moderate controllable reflection factors automatically is described in 1974 by Cusack et al. [1]. The apparatus described in [1] uses two parallel lead screws ( 36 , 37 ) in a housing, ( FIG. 7 , 8 ). Using horizontal translation mechanisms ( 41 , 42 ) and electrical servo or stepper motors ( 43 , 44 ), each of which moves a cylindrical dielectric probe ( 38 , 39 and FIG. 9 ) along the central conductor of a slotted coaxial airline ( 86 , 87 , FIG. 7 ) {Cusack. [1], page 1146 bottom right}, independently from each-other. The said dielectric probes ( 45 ) envelope entirely the central conductor ( 46 ) in the coaxial slotted airline structure ( 47 ) ( FIG. 9 ). This type of tuner generates, because of the use of purely dielectric probes, moderate reflection factors of the order of 0.8–0.85 and covers a frequency range of about one octave (f max :f min =2) (Cusack et al. [1]).
FIG. 8 shows a cross section of the tuning area and the concept of the two horizontal probe tuner of Cusack et al. [1]. Total reflection at the tuner test port ( 49 ) is generated by superposition of both reflections ( 50 , 51 ) of the two dielectric probes ( 52 , 53 ). Changing the distance ( 48 ) between the two probes changes the amplitude of the reflection factor, whereas moving both probes horizontally and simultaneously ( 54 , 55 ) changes the phase of the reflection factor.
Alternative configurations of the cylindrical dielectric probes used by Cusack et al. [1] are possible (though not yet reported in the literature), as shown in FIG. 10 . Here a fully dielectric square slug ( 56 ) slides on the center conductor ( 59 ) of the slabline ( 57 , 58 ), leaving a small air gap ( 60 ), or no gap at all. The effect of this type of probe is the same as in the case of the cylindrical probe of FIG. 9 .
BRIEF SUMMARY OF THE INVENTION
This invention involves a new type of metal-dielectric combination RF probe (slug) used in the type of electromechanical tuner described by Cusack et al. [1]. Whereas Cusack uses RF probes made entirely of dielectric material ( FIG. 9 ) and are of cylindrical form, resembling thick-walled dielectric tubes ( FIG. 9 ), the RF probes proposed here are made of a combination of dielectric material and metal ( FIG. 11 ). The dielectric material is a thin tube ( 61 ), which is embedded inside a square metallic block ( 62 ). The total is mounted as a single unit and slides on the central conductor ( 63 ) of the slotted airline. The probe is moved horizontally attached by a top pin ( 64 ) to the horizontal carriage of the tuner ( 88 , 89 in FIG. 8 ).
Two such RF probes are used in a tuner ( FIG. 12 ) and their position is controlled by stepper motors and associated horizontal displacement mechanisms ( FIG. 7 ).
Compared with the previously used fully dielectric RF probes ( FIG. 9 and by extension FIG. 10 ), this new structure allows much higher reflection factors of up to 0.98 and higher bandwidth, beyond the limit of one octave reported by Cusack et al [1].
Calibrating this tuner in order to reproduce impedances later on in operation is not an obvious task. The tuner has to be characterized by means of two-port S-parameter measurements on a vector network analyzer for a large number of N positions of each of both carriages.
The tuning resolution is a direct result of the number of points N used in the calibration. If a resolution of 5 degrees on a Smith Chart is required then N=360/5=72, for each of both carriages, meaning that the combined number of tuner positions would be 72×72=5,184, for which S-parameters should be measured. Considering data acquisition and associated delays for mechanical movement of the tuners to be set to the corresponding positions, would require several hours for calibrating a tuner at a single frequency, which is unacceptable.
We therefore propose a new calibration method, consisting of positioning the tuner carriages at N+N=2N positions (instead of N×N) and measuring S-parameters over a wide frequency range, including all frequencies of operation of the tuner, then descrambling the data, de-embedding the influence of the tuner housing, and have the tuner fully calibrated at high resolution and over a wide frequency range within one or two hours.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention and its mode of operation will be more clearly understood from the following detailed description when read with the appended drawings in which:
FIG. 1 depicts Prior Art, a load pull test set-up using passive electro-mechanical tuners.
FIG. 2 depicts Prior Art, a front view of an electromechanical slide screw tuner using a single horizontally and vertically controllable RF probe.
FIG. 3 depicts Prior Art, a cross section of the RF probe of a slide screw tuner inside a parallel plate airline (slabline)
FIG. 4 depicts Prior Art, a front view of an electromechanical pre-matching slide screw tuner, using two independently controllable RF probes.
FIG. 5 depicts Prior Art, a presentation of the tuning area of a pre-matching tuner on the reflection factor display (Smith Chart).
FIG. 6 depicts Prior Art, a front view of an electromechanical slide screw tuner using two RF probes, which move simultaneously horizontally and vertically.
FIG. 7 depicts Prior Art; a top view of an electromechanical tuner using two horizontally movable RF probes.
FIG. 8 depicts a cross section of an electromechanical tuner using two horizontally movable metal-dielectric combination RF probes.
FIG. 9 depicts Prior Art, a cross section of a cylindrical RF probe, movable inside a coaxial airline in the apparatus described by Cusack [1].
FIG. 10 depicts partly Prior Art, a cross section of rectangular dielectric RF probe, movable inside a parallel plate airline (slabline).
FIG. 11 depicts a perspective view of the new proposed combination RF probe which can slide inside a parallel plate airline (slabline).
FIG. 12 depicts a perspective view of two new combination RF probes embedded and sliding inside the parallel plate airline (slabline)
FIG. 13 depicts an extension of Prior Art, a cross section of rectangular dielectric RF probe, movable inside a parallel plate airline (slabline), but without air gap between the dielectric material and the center conductor
FIG. 14 depicts Prior Art, a presentation of the maximum tuning range of a single probe slide screw tuner or a two Probe tuner by Cusack [1] on the reflection factor display (Smith Chart)
FIG. 15 depicts a cross section of the proposed metal-dielectric RF probe, using a dielectric ring of medium thickness.
FIG. 16 depicts a presentation of the maximum tuning range of a two probe tuner using metal-dielectric combination RF probes, movable horizontally inside the parallel plate airline (slabline).
FIG. 17 depicts a cross section of the proposed metal-dielectric RF probe, using a high thickness dielectric ring.
FIG. 18 depicts a cross section of the proposed metal-dielectric RF probe, using an low thickness dielectric ring.
FIG. 19 depicts a comparison of the frequency response of two horizontal probe tuners using either fully dielectric probes ( 75 , prior art) or new metal-dielectric probes ( 74 , this invention).
FIG. 20 depicts prior art, a typical set-up used to calibrate electromechanical microwave tuners employing a control computer and a calibrated vector network analyzer.
FIG. 21 depicts partly prior art, the tuning mechanism of two-horizontal-probe tuners represented on a Smith Chart.
DETAILED DESCRIPTION OF THE INVENTION
We propose an electro-mechanical microwave load pull tuner as shown schematically in FIGS. 7 and 8 , which comprises a slotted transmission airline ( 40 ) with an input or test port ( 65 ) and output or idle port ( 66 ). The airline is mounted inside an enclosure ( 67 ), which also holds two translation mechanisms ( 36 , 37 ), in the form of horizontal lead screws. The horizontal lead screws are driven via timing belts ( 41 , 42 ) by stepper motors ( 43 , 44 ), which are fixed on the base ( 67 ) of the tuner. The lead screws carry mobile carriages ( 68 , 69 ) that can be moved over the whole length of the tuner body ( 67 ).
The carriages ( 68 , 69 ) of the tuner shown in FIG. 7 , 8 also carry the metal-dielectric combination probes, inserted into and sliding horizontally along the axis of the slotted airline ( FIG. 12 ).
Alternative methods of movement control are known and possible, but shall impede on this invention as being the core of it.
The core of the invention is the nature of the proposed metal-dielectric combination RF probes. It has been established experimentally that, if the probes are made of entirely of dielectric material (as in [1]), then the frequency coverage and the amplitude of the reflection factor generated are low. Typical values of Gamma=0.8 (or VSWR=10:1)(80) are obtained over a frequency span of one octave (Cusack et al. [1]). This is because the probes act mainly as low impedance sections of the transmission airline and each create a moderate reflection factor of approximately 0.6 ( 78 , 79 )(depending on the dielectric constant of the dielectric material used, such as Teflon with epsilon=2.2); the individual reflections of each probe are combined at the test port of the tuner, generating a moderate total reflection factor ( 80 , FIG. 14 ). The optimum length of each dielectric probe is one-quarter wavelength at the center frequency of operation and the reflection factor declines thereafter (trajectory ( 75 ) in FIG. 19 ).
Fully metallic probes, as used in typical slide screw tuners ( FIG. 3 ), do not act as impedance transformers, at least not at low and moderate frequencies, up to 12 GHz. They act predominantly as variable capacitances, which provide, by nature, much higher bandwidth. Also, by positioning the metallic probes of slide screw tuners ( FIG. 3 ) very close to the central conductors (air gap ( 11 ) being close to zero) large capacitances can be generated resulting in higher reflection factors, of the order of 0.9, than with dielectric-only probes. The disadvantage of the fully metallic probes ( 9 ) in slide screw tuners ( FIG. 2 ) is that the probes have to be positioned vertically, very accurately, close to the central conductor and be held at this close distance for horizontal movement over a long section, spanning over one half of a wavelength, in order to cover 360 degrees of phase change of the reflection factor.
The proposed new metal-dielectric combination probes ( FIG. 11 , 12 , 15 ) include a metallic square block ( 62 ), which is as wide as the slot of the slotted airline ( 70 , 71 ) and has a round opening in its center ( 72 ), which is filled with dielectric material ( 61 ), which slides on the central conductor ( 63 ) of the slotted airline (slabline). A holding pin ( 64 ) at the top of the metal block connects the probe with the driving mechanism.
Such a probe inserted into a two-horizontally-movable-probe tuner as described by Cusack et al. [1] offers several advantages of full metallic probes, i.e. higher reflection ( 76 , FIG. 16 ) and larger bandwidth ( 74 , FIG. 19 ), since the capacitive effect of the metallic component supercedes the impedance transformation effect of the pure dielectric.
This better RF performance of the metal-dielectric combination probes, combined with the fact that these probes are vertically stationary, i.e. their distance from the center conductor of the slotted airline is constant, thus eliminating the need for very precise vertical positioning, makes them a valuable alternative for high reflection factor tuning.
By changing the thickness of the walls of the dielectric cylinder core of the new metal-dielectric probes ( FIG. 13 , 15 , 17 , 18 ) from a purely dielectric probe ( 81 , FIG. 13 ) to an almost purely metallic ( 82 , FIG. 18 ) probe, the basic behavior of the tuners can be varied between the narrow-band-moderate-reflection case of the fully dielectric probes [1], FIG. 14 ( 80 ), FIG. 19 ( 75 ), and the wideband-high-reflection case of the fully metallic probes of the slide screw tuners, FIG. 3 , FIG. 16 ( 76 ) and FIG. 19 ( 74 ). FIG. 18 shows such a probe with a very thin walled dielectric ( 73 ), but it is obvious that the thickness of the core wall cannot be set to zero, without the risk of electrical contact between the center conductor and the metallic probe itself. FIG. 17 shows such a probe with thick walled dielectric core ( 72 ), and, again, it is obvious that, increasing farther the thickness of the dielectric material will cut the metallic part ( 82 ) in two and we will find ourselves in the case of the fully dielectric probe ( FIG. 13 ), with its limited reflection factor and frequency bandwidth behavior.
Furthermore, it is important to recognize that the thickness of the dielectric material is most important on both lateral sides of the central conductor ( 84 , 85 , FIG. 17 ), because most of the electric field in the transmission airline in concentrated in this region, since it represents the shortest path between the center conductor ( 63 ) and the sidewalls ( 70 , 71 ) of the slabline.
When an appropriate thickness of dielectric material is used of roughly ⅓ to ⅔ of the distance between the sidewall of the slabline and the central conductor ( FIG. 15 ), very high reflection factors can be reached, as shown in FIG. 16 ( 76 ). Values of up to 0.98 (VSWR˜100:1) are easily obtainable over a frequency range of several hundred MHz or several GHz.
The operational frequency range itself of this tuner strongly depends on the length of the probes. The longer the probe the lower the frequency of operation.
The basic behavior of the various types of probes used in this tuner is shown in FIG. 19 . Here both extreme cases are depicted: Trace ( 75 ) corresponds to the reflection factor behavior of the tuner as a function of frequency for the tuner of Cusack et al. [1] with fully dielectric probes, showing one octave bandwidth and a moderate reflection. Trace ( 74 ) corresponds to a tuner using the proposed metal-dielectric combination probes with thin dielectric walls, showing high reflection over a wider frequency range.
The way in which the two individual reflection factors at the two metal-dielectric probes work is demonstrated in FIG. 21 . Arrow ( 76 ) shows the trajectory of the reflection factor when the distance between the two probes changes, but the virtual center between them remains stationary related to the test port of the tuner. In FIG. 21 , each trajectory of the reflection factor follows the same form shaped like the number ‘8’ marked with dotted lines, when the virtual center between the two probes remains stationary compared to the test port of the tuner.
Arrow ( 77 ) shows how the trajectories of the reflection factor change when both probes are moved simultaneously, so that the distance between them stays the same, but the distance of their virtual center changes compared to the test port (in this case getting away from the test port).
It is clear that by modifying the positions of both probes any point on the reflection factor plane (Smith Chart), within the amplitude tuning range of the tuner, can be reached ( FIG. 16 ).
In order to make the described tuner useful for load pull or noise measurements, it has to be pre-characterized on a calibrated vector network analyzer (VNA) ( FIG. 20 ).
In the set-up of FIG. 20 , used to calibrate the tuner, a control computer sends digital control signals to the motor control electronics of the tuner and sets its probes at certain precalculated positions. Once the probes are settled the control computer triggers readings of two-port S-parameters from the calibrated vector network analyzer (VNA). The data read from the VNA is then saved in a data file (calibration file) on the storage media of the control computer (hard-disk).
The calibration of the tuner has to be done for a great number of probe positions, in order to effectively cover the total area of the Smith Chart. For instance, if we want to cover every 5 degrees of phase, then we need at least 72 horizontal positions (360/5=72) for each probe. For the combination of both probes we need then 72×72=5184 positions. Considering the data transfer time and the motor movement time, such a procedure would require several hours. This kind of delay is not acceptable for this type of automatic measurement procedure.
We therefore propose a new calibration technique for this type of tuner. Using the same set-up as in FIG. 20 the following algorithm is used:
Both probes are set to their initial positions, one closest to the tuner test port and one closest to its idle port, at the opposite extreme.
The S-parameters of the tuner two-port are measured for the whole frequency band of operation of the tuner and saved in a data file, named S0.
Then, while probe 2 rests at the far end of the tuner, probe 1 is moved to a number of equidistant steps towards the far end of the tuner (in our example 72 times). Each time the S-parameters are measured for the same frequencies as previously and saved in a data file, named S1. File S1 is, in this case, 72 times larger than file S0.
Then probe 1 is returned to its initial position, closest to the tuner test port and probe 2 is moved in equal steps towards the test port, again in our example 72 times. Each time the S-parameters are measured over the same frequency range and saved in a third data file, named S2. This file has the same size as S1.
Then the data stored in files S0, S1 and S2 are processed in memory of the control computer to generate the final tuner calibration file. This data processing consists of cascading, for each frequency point and each probe 1 position, the S-parameters of file S1 with the inverse S-parameters of file S0 and then cascade the result of this operation, again for each frequency point and each probe 2 position with the S-parameters of file S2.
If the number of frequency points measured is N, the number of probe positions M, then the data points measured are (2×M+1)×N and the data saved in the final tuner calibration file (M×M+1)×N. Since all data manipulations and cascading of the data saved in files S0, S1 and S2 are executed in the computer memory with virtually no time delay, this calibration method is very efficient.
This procedure lasts a reasonably short time, since a total of 72+72+1=145 points (instead of 5184) are measured. The improvement in calibration time increases proportionally to the number of horizontal positions and thus to the selected tuning resolution. At 72 positions the new method is 36 times faster, at 200 positions it is 100 times faster. | Combination metal-dielectric microwave probes are sliding on the central conductor of an electro-mechanical microwave two-probe load pull tuner and create higher reflection factor over a wider frequency bandwidth than was previously possible using pure dielectric probes. The microwave probes are made of a combination of metal and dielectric materials in form of a square metallic slug body with a dielectric cylindrical core embedded inside. The cylindrical dielectric core also guides the probes and allows them to slide smoothly on the central conductor of the tuner airline without major alignment. The probes are positioned horizontally using a remote translation mechanism and allow continuous coverage of the Smith chart over a high frequency and VSWR (reflection factor) range. The mutual horizontal distance between the probes determines the amplitude of the reflection factor, whereas their common distance from the tuner test port determines its phase. | 6 |
This application is a continuation-in-part of my copending application Ser. No. 769,857, filed Feb. 18, 1977 and now abandoned.
BACKGROUND AND SUMMARY OF INVENTION
Recent years have seen widespread introduction of large rubber tired front end loaders in mining operations previously handled by crawler-type shovel dipper or dragline machines. By "large" reference is made to loader buckets having a capacity of the order of 9-22 cubic yards (or 7-17 cubic meters). Key factors which influenced this trend were considerably lower capital investment, better supplier availability of machines to suit high demands, and more versatility and flexibility in application.
Typical mining applications of front end loaders are stripping overburden and loading of ore or coal. Overburden tends to be a mixture of fines and medium-to-large blocks or slabs of shot material such as sandstone, limestone, basalt, quartz rock mixed with shales and clay. Ores typically are mixtures of fines and small-to-medium sized chunks which are denser than overburden. Coal, which is lighter than overburden in weight, is usually shot and is deposited in veins or seams that many times are multi-seam type separated by overburden partings. The front end loader buckets generally require teeth to dig and load these materials.
In order for a front end loader vehicle to get a load of material in its front-mounted bucket, it must first advance nearly horizontally into the material and then sweep up in an arc under the trapped material. To accomplish this, the bucket and loader encounter the aforementioned material which is difficult to load due to the very extreme variations in size and shape plus weight variations. The chunks or slabs tend to interlock and require high energy to penetrate and prize or lever the material into the bucket. Uneven terrain, which is generally typical, further reduces ease of penetration into the material.
To overcome these many and varied loading obstacles, a front end loader which is propelled through an articulated chassis on rubber tires, moves the bucket hydraulically in an up and down, arc-type or combination direction, producing two types of medium-to-high load forces on the tooth system. First, there is the penetration load form developed as the front end loader and bucket advances into the material being loaded. The variables of material size, weight and location require the teeth to gouge, break out and dig under the material in a fashion analogous to that encountered in a dozer. Second, a jacking or fluttering loading is encountered due to the variables in material shape and location as the teeth are moved up and down to allow both forward and upward bucket penetration through tight openings between chunks, blocks or slabs. More particularly, the jacking or fluttering of the tooth system stems from the sporadic engagement of the teeth with difficult to dislodge material whereby the teeth move up or down or even laterally in order to pass beyond the obstinate material. It will be appreciated that this is not usually uniform across the width of the bucket so that different teeth may be in different fluttering and penetration modes at the same time. Although, the background of the invention is discussed in terms of front end loaders and, more particularly, the jacking operation which characterizes them, such jacking operations have been characteristic of earlier earth moving devices, though generally not as severe. In other words, the problem has existed but had not been brought home to art workers quite as strongly prior to the advent of the large front end loader.
The severity of these jacking forces particularly in front end loaders gave rise to difficulties with conventional excavating teeth, particularly those which consisted of components secured to a vertically extending lock or key.
The vertically extending lock has, and still is, the preferred form for connecting the point and adapter components of the tooth. Inasmuch as the point components, in particular, wear rapidly, replacement is frequent--in some instances, daily. With a vertically extending lock, disengagement of the point from the adapter is easily achieved by merely using a hammer or sledge to pound out the locking pin. In contrast, the horizontally installed locking devices are difficult to remove because there is generally only a short distance between adjacent teeth, thereby limiting the type of drift pin or chisel and hammer or sledge arc--so much so that horizontally locked teeth have become known in the field as "knuckle-busters". Thus, horizontally extending pins were undesirable because of the difficulty of removal. On the other hand, the vertically extending pins were subject to ejection in the jacking mode. The loss of the locking pin (as from severe jacking) constitutes one of the most devastating things that can happen to an excavating tooth. Without the pin, the point generally will come off, exposing the adapter--and, if the machine is not stopped immediately, the adapter can be ruined because it is not intended to be the penetrating component. Even the stoppage is expensive--particularly when unscheduled.
Among the teeth that suffered from this loss of pin drawback were those constructed according to U.S. Pat. Nos. 2,919,506 and 3,079,710. These teeth made use of a combination of special bearing surfaces to absorb severe shock loads and to prevent the development of localized strains and negative thrust, these teeth having been referred to as "stabilized conicals".
Negative thrust tends to pull the point off the adapter. Prior to the 3,079,710 patent, this was resisted by providing a pin lock structure which was characterized by high shear and bearing strength to provide an artificial positive thrust at installation. Such an artificial positive thrust meant extreme difficulty in pin lock removal--thereby frustrating one of the principal objectives of a pin lock: easy removability for replacement while still providing secure locking during working.
The stabilized conical tooth changed the tooth standards--previously the trend was to tighter and tighter fits between the point and adapter to avoid localized strain and negative thrust, and to use bigger and stronger pin locks to resist negative thrust. With the supplemental beam and conical bearing surfaces of the stabilized conical tooth, a most desirable looseness in fit not only could be tolerated--but put to advantage, all while using a light, easily installed and removed pin lock system. Stabilized conical teeth, which had performed brilliantly under all conditions throughout the world for many years started coming apart due to locking pin loss when used on front end loaders. Thus, with the more frequent incidence or severity of the "jacking" stresses, this whole advantageous trend was jeopardized. For example, more frequent loss of pins made the desirable loose fit suspect. Here it should be appreciated that excavating teeth are designed for the exceptional occurrence--the relatively infrequent stress or impact that might destroy the system. If the excavating were always performed in dry sand--the only problem is abrasion. But the manufacturers of excavating equipment, particularly teeth, cannot be sure that a particular piece of equipment may not be moved from a stressless environment to one having high impact loadings. So teeth must be built to withstand the infrequent but severe stresses--the connection of the tooth parts must approach the strength of the connection of the bucket itself.
The stabilized conical tooth point was felt to be the best design because it was rugged, simple, had a relatively massive box section for strength and resistance to corner stresses, had conical bearing surfaces to resist lateral loads, and stabilizing "flats" to resist negative thrust. Yet, with all of this, it was this highly regarded tooth that encountered difficulty in staying together on front end loaders subject to jacking stresses.
The instant invention solved this problem of severe jacking stresses. According to the invention, the vertical pin lock is still used--no need for going to the "knuckle-buster". Further, the real advantage of looseness of fit is still present--contrary to expectation, and along with still being able to use the simple, light-weight pin lock system.
At first this was not felt possible because problems were experienced with the logical approach of making the pin installation more secure. The vertical lock in the stabilized conical tooth was of the corrugated type seen in U.S. Pat. No. 3,126,654. When these teeth encountered pin loss problems, the initial attempts focused on the pin locks themselves--changing the corrugated contour as seen, for example, in U.S. Pat. No. 4,061,432. This improved the situation relative to jacking but was not a complete answer so that in especially difficult cases, return to the horizontal pin lock was considered. The obvious solution to the problem (while still retaining the vertical pin lock) was to deform the pin as in U.S. Pat. No. 2,055,265--but this then created a problem of removal.
As a last ditch effort to avoid going to this unattractive arrangement, tests were performed with a tooth construction not used in excavating but only in dredging. Surprisingly enough, this different arrangement showed promise in solving the pin loss problem due to jacking of front end loader teeth. This was surprising because the dredge teeth were designed for a different function. For example, the forces normally encountered in dredging were generally random and seldom applied at angles greater than 45° to the longitudinal center line. In contrast, the jacking stresses were cyclic and often applied at angles of 80° to the longitudinal centerline.
Further, contra-indicating the use of the dredge tooth structure was the design of the point itself. It had, at the rear of the point, four rearwardly extending tongues--one for each of the top, bottom and sidewalls. The idea of having four rearwardly extending tongues on a point was old as shown by U.S. Pat. No. 1,803,311 and more recently, in U.S. Pat. No. 3,708,895, this being representative of the use of rearwardly extending tongues in the dredge point art. Also representative of the dredge point art is the structure seen in commonly-owned U.S. Pat. No. 4,080,708 where, in addition to the rearwardly extending tongues, the tooth is equipped with internal stabilizing bearing surfaces at the apex of the point socket according to U.S. Pat. No. 3,079,710. It was this 4,080,708 patent structure that showed the promise indicated above. This was unexpected because pin securement was deemed to stem from having a strong structure around the pin--as for example, a continuous section, viz., a box, at the point rear as in U.S. Pat. No. 3,790,353--rather than one that was essentially "weakened" by the removal of metal, in effect, from the box section to provide the tongues.
It is believed that the rearwardly extending tongues, particularly those extending from the top and bottom walls through which the vertical pin extends cooperate in a new manner with the stabilizing flats. These top and bottom tongues, by virtue of the fact that they support the pin independently of the remainder of the box section now can accommodate to the pin shift upon the application of the cyclic forces incident to jacking.
Not only was it necessary to go to a completely contra-indicated point rear end structure (the four tongues) but it was also essential to provide a specific forward part, viz., the dimensional arrangement of the so-called "stabilizing flats". The advantages of a vertically installed pin or keylock can be retained in an excavating tooth which is subject to the severe jacking stresses on a front end loader where the supplemental bearing surfaces are constructed to have a width to length ratio of approximately 2.5 and with the surfaces separated so that the section between surfaces has a width to spacing ratio of approximately 1.8. More particularly, the adapter nose and conforming point socket are defined by forwardly convergent top and bottom walls which terminate in a generally box shaped apex which in turn provides generally parallel stabilizing upper and lower surfaces--each of these surfaces having a width to length ratio of approximately 2.5 and the surfaces separated to obtain a width to thickness ratio of approximately 1.8 thus providing an optimum configuration balancing the considerations of surface area, strength vs. weight and external shape of point.
DETAILED DESCRIPTION
The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which
FIG. 1 is a perspective view of a front end loader employing teeth constructed according to the teachings of the instant invention;
FIG. 2 is a an exploded perspective view of the inventive excavating tooth with the parts separated and with the adapter component illustrated in fragmentary form;
FIG. 3 is a top plan view of the point component of the tooth of FIG. 2;
FIG. 4 is a side elevational view of the point of FIGS. 2 and 3;
FIG. 5 is a top plan view of the adapter component of the FIG. 2 tooth;
FIG. 6 is a side elevational view of the adapter of FIGS. 2 and 5;
FIG. 7 is a diagrammatic view (a side elevation) of a tooth showing various forces, lever arms and angles identified thereon;
FIG. 8 is a simplified version of FIG. 7; and
FIG. 9 is a plot of the reaction force ratio as a function of the load angle.
In the illustration given, and with reference first to FIG. 1, the numeral 10 designates generally a wheel equipped tractor or like vehicle which supports at its forward end a bucket 11 equipped with a plurality of excavating teeth 12 along the bottom forward edge 13. The bucket 11 is shown in its penetration or material entering mode and a small amount of material 14 is seen within the bucket 11. As further material is accumulated, the bucket 11 is swung upwardly preparatory to swinging laterally and dumping the load.
The teeth that have been found especially advantageous for the severe operating conditions previously discussed include a supporting member 15 (normally called an "adapter") which is fixed to the bottom wall of the bucket 11 as by welding along the undersurface 16. Inasmuch as the adapter 15 is not the principal penetrating component, the life expectancy is such as to accommodate a series of replacement points, one of which is designated 17 in FIG. 2. The point 17 is equipped with a leading or penetrating edge 18 at one end and at the other end with a socket 19 shown in dotted line in FIG. 4. The socket 19 conforms to and receives the forward portion or nose 20 of the adapter 15.
For the purpose of releasably securing the point 17 on the adapter 15, aligned openings as at 21, 22 and 23 are provided. As can be appreciated from a comparison of the showings in FIGS. 2, 4 and 6, the openings 21 and 23 are provided in the point 17 while the opening 22 is provided in the adapter 15. The opening 22 in the adapter 15 is enlarged to receive and support a resilient plug member 24 (see the upper right hand portion of FIG. 2) which serves as a lock for a vertically elongated pin 25 which extends through the aligned openings 21-23.
The socket 19 (referring to FIG. 4) is defined by top and bottom walls 26 and 27 and by sidewalls 28 and 29 (see FIG. 3). The sidewalls 28 and 29 are slightly convergent in a forward direction to provide the necessary draft for casting. The forward convergence of the top and bottom walls 26 and 27 is more pronounced and optimally the walls 26 and 27 (and the corresponding confronting walls 30 and 31--see FIGS. 5 and 6) are longitudinally arcuate along a parabolic curve.
The socket 19 and the conforming nose 20 each terminate in an apex which is box-shaped as at 32 relative to the socket 19 and 33 relative to the nose 20 (compare FIGS. 4 and 6). Relative to the box shaped apex 32 in the socket 19, generally parallel upper and lower surfaces 34 and 35 are provided as extension of the top and bottom walls 26 and 27. I have discovered that the advantageous operation previously described is achieved when the surfaces 34 and 35 (and the corresponding surfaces 36 and 37) in the apex portion 33 of the nose 20 are constructed with a width to length ratio of about 2.5. By length, I refer to the longitudinal dimension of the tooth, i.e., the dimension extending between the penetrating end 18 and the open end of the socket 19. For example, the prior art teeth were made with "flats" having a width of 115 mm., a length of 13 mm. and a spacing of 30 mm. yielding a W/L ratio of 8.85 and a W/S ratio of 3.83 for the size tooth having a nominal dimension of 51/2" (140 mm.) across the base of the nose. The inventive tooth has a corresponding W/L or surface ratio of 2.55 and a W/S or spacing ratio of 1.83 derived from a width of 71.5 mm., a length of 28 mm. and a thickness of 39 mm. For a larger size of inventive tooth corresponding to the prior art tooth having a nominal width of 81/2" (215 mm.) across the base of the nose, I provide a width of 114 mm., a length of 44 mm. and a spacing of 63.5 mm., yielding a W/L ratio of 2.59 and a W/S ratio of 1.80.
Additionally, I have found it advantageous to provide the keyway opening as illustrated in the accompanying drawing. For example, each of the walls 26-29 is extended rearwardly to provide ears 38-41 (compare FIGS. 3 and 4). The ears 38-41 are received within correspondingly contoured recesses 42-45 within the adapter 15. The ears 38 and 39 project rearwardly further than the ears 40 and 41 and it is seen that the rear walls 21a and 23a of the aligned openings 21 and 23 are spaced rearwardly of the rear edges of the tongues 40 and 41. Thus, the location of the keyway is spaced rearwardly of the nose 20 so as to retain the integrity of the nose and socket and thus develop more effective resistance to severe bending loads, particularly those incident to jacking or fluttering.
In operation, during the aforementioned jacking or fluttering loading, the stabilizing surfaces 34 and 36 or 35 and 37 come into engagement. These surfaces are spaced apart slightly in order to achieve a fit and are sized accordingly to the optimum relationship previously described so as to withstand the maximum encountered bending loads incident to jacking. The rearwardly extending ears 38-41 may also assist in a secondary manner in resisting such bending loads. Although it is preferred to utilize all four ears 38-41, in some instances it may be satisfactory to utilize only the upper and lower ears 38 and 39, reinforced if necessary.
The fact that the jacking operation results in different forces acting on the adapter nose 20 from those encountered during dredging can be demonstrated mathematically--with reference to the diagrams on the second drawing sheet, viz., FIGS. 7-9. As can be first appreciated by a consideration of FIG. 8, the load P applied to the point 17 at an angle θ 1 (to the longitudinal center line of the point) results in forces R 1 , R 2 and R 3 acting on the nose 20.
More particularly, R 1 is the reaction force on the "flats", viz., the surfaces 36 or 37; R 2 is the cone reaction force, viz., the forwardly convergent walls 30 and 31 while R 3 represents the reaction force on the walls of the ear sockets 44 and 45. The load P is defined as being applied at a distance L 0 from the imaginary intersection of the surfaces 30 and 31--see the dashed line 30a in FIG. 7. To compute the reaction forces, certain trigonometric relationships are established from the dimensions represented in FIG. 7. For example:
θ.sub.2 =tan.sup.-1 (Y/L.sub.0)
L.sub.1 =L.sub.0 /cos θ.sub.2
L.sub.2 =L.sub.1 [sin (θ.sub.1 +θ.sub.2)]
R 2 can be derived from summing the x or horizontal forces to zero, i.e., ΣF x =0. The x component of R 2 , viz., R 2x can be seen to be P cos θ 1 . The y component (R 2y ) is R 2x tan φ. From this hypotenuse R 2 is seen to be
R.sub.2 =P cos θ.sub.1 (1+tan.sup.2 φ)1/2
R 3 can be derived from summing the moments to zero, viz. ΣM 0 =0, from which
R.sub.3 =P (L.sub.2)/(L.sub.3), or ##EQU1## R.sub.1 can be derived from summing the y or vertical forces to zero, i.e., ΣF.sub.y =0. From this:
R.sub.1 =P sin θ.sub.1 -R.sub.2y +R.sub.3, or
R.sub.1 =P sin θ.sub.1 -P cos θ.sub.1 tan φ+R.sub.3, or
R.sub.1 =P [sin θ.sub.1 -cos θ.sub.1 tan φ]+R.sub.3
When φ is determined to be 55° for a constant strength parabolic cantilever, defined by Y=constant times square root of X and passing through coordinates determined by W/L=2.5 and W/H=1.8 as in FIG. 7, a series of values of R 1 , R 2 and R 3 can be obtained as a function of P and θ 1 . The ratio of these reaction forces to the applied load P, viz., R 1 /P, etc., is plotted as a function of θ 1 in FIG. 9. From this, the following is seen:
1. At low θ 1 , the thrust is on the cone, no appreciable load on the "flats";
2. At medium θ 1 (θ 1 ≦45°), the load on the flats is not as great as the load on the cone; and
3. At high θ 1 (45°<θ 1 <90°) the force on the flats is quite high.
This was not characteristic of the dredge tooth operation, previously referred to and wherein there happened to be rearwardly extending top, bottom and side tongues and flats. In the dredge teeth, there was no simple plane in which the forces would usually be applied, so the design reflected virtually the same elements top and bottom as on the sides, viz., flats and rearwardly extending tongues. Thus, a force applied in a horizontal plane would be resisted in approximately the same manner as one applied in the vertical plane. This operation was not characteristic of the excavating teeth subject to jacking so there was no indication that a combination of flats and ears, much less the optimum arrangement presented herein, would be effective in resisting jacking forces. Thus, not only was there a difference in the type of stress encountered between excavating and dredging teeth, but there was also difference in basic philosophy. That design philosophy, as just indicated, resulted in virtually a square apex in the nose and socket to accommodate omni-planar forces. Thus, there was nothing either from the design or the operation standpoints to indicate that any dredge tooth concepts would be helpful in an excavating tooth subject to jacking stresses.
The criticality of the arrangement proposed, viz., the rearwardly extending ears and the dimensional ratios concerning the flats can be appreciated from the fact that the strength of the flats matches the strength of the nose at the keyway opening 22 for high θ loadings.
The strength of the flats can be analyzed by published stress formula developed in the `40`s and `50`s by N.A.C.A. (NASA's predecessor) and S.A.E., for short, broad cantilevers such as parallel gear teeth, which the flats resemble in form and function. The force on the flats is taken as acting at the apex 30a of a parabolic (in the side view) constant-strength section, which is the basic shape of the nose illustrated. This results in a stress level of (R 1 /W) (5.8).
Utilizing the formula for a cantilever nose where 33% of the nose width is taken up by the keyway opening, the stress level at the keyway is also (R 1 /W) (5.8).
When flats are sized larger than the optimum recited (smaller W/H and W/L numbers), this results in a prediction of flats of excess strength relative to the critical section across the keyway. In addition, the required volume of metal increases, but at a greater rate, so the strength-to-weight ratio decreases and metal use is inefficient relative to the optimum. When flats are sized smaller than the optimum (larger W/H and W/L numbers), the top and bottom surfaces areas available to carry the contact forces acting on them are reduced--if this reduction of area is significant, detrimental peening and surface deformation results.
While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details hereingiven may be made by those skilled in the art without departing from the spirit and scope of the invention. | An excavating tooth especially adapted for use with large front end loaders which encounter repetitive jacking stresses, the point component of the tooth being equipped with uniquely sized bearing surfaces and rearwardly extending top and bottom tongues for the support of a vertical locking pin. | 4 |
TECHNICAL FIELD
The present invention relates to a process which makes it possible to improve the adhesion of carbon fibres with regard to an organic matrix forming, with these fibres, a composite material and resulting from the chain polymerization of a curable resin.
This process, which makes it possible to obtain composite materials with noteworthy properties of resistance to stresses, both transverse (that is to say, perpendicular to the direction of the carbon fibres) and longitudinal (that is to say, in the direction of the carbon fibres), is very particularly advantageous in the aeronautical, aerospatial, railway, ship building and automobile industries, whether in the production of structural components, engine components, passenger compartment components or bodywork components.
However, it can also be used in other types of industry, such as the armaments industry, for example in the production of components participating in the construction of missiles or of missile launch tubes, or that of sports and leisure articles, for example in the production of articles intended for water sports and for sports which involve sliding.
STATE OF THE PRIOR ART
Composite materials are heterogeneous materials which make it possible to make use of the exceptional mechanical properties of materials, the manufacture of which is only known in the form of fibres (and not in bulk form), by embedding them in a matrix formed of a cured organic polymer (or resin), which makes it possible to bond the fibres to one another, to distribute the stresses in the composite material and to protect the fibres against chemical attacks.
A necessary condition for the production of a high performance composite material is that the bonding between the fibres and the matrix of which it is composed is good. This is because, if the fibres/matrix bonding is inadequate, then a composite material is obtained with mediocre transverse mechanical properties (such as resistance to shearing) and thus with very limited possibilities of use, components made of composite materials generally being intended to operate under a state of three-directional stress.
Carbon is chemically rather unreactive and naturally exhibits a low adhesion with regard to polymer matrices. Consequently, manufacturers of carbon fibres have straightaway sought to adapt their fibres to the resins intended to be used as matrices by manufacturers of components made of composite materials.
Thus it is that the following have been proposed:
1) surface treatments which are all targeted at creating, at the surface of the fibres, functional groups capable of reacting with chemical functional groups carried by the resins; they are mainly electrolytic or chemical oxidation treatments (see, for example, JP-A-3076869 [1]) but other types of treatment have also been described, such as plasma heat treatments (see, for example, EP-A-1 484 435 [2]), electrolysis in an acidic or basic medium (EP-A-0 640 702 [3]) or the implantation of atoms of Si or B type (JP-B-2002327374 [4]);
2) the use of specific sizing agents, that is to say by the deposition, on the surface of the fibres, of products having the role of enhancing the compatibility of the fibres with regard to the resins, of facilitating their impregnation by the resins and of providing “attaching” between the fibres and the matrices formed by the polymerization of these resins; generally, the sizing agents used are polymers or copolymers with complex chemical structures, the choice of which is mainly guided by experience; and
3) the grafting to the surface of the fibres of an elastomeric phase (Wu et al., Carbon, 34, 59-67, 1996 [5]) or of polymers of polyester, vinyl polymer (in particular polystyrene) or polyacetal type (Tsubokawa, Carbon, 31, 1257-1263, 1993 [6]) capable, here again, of enhancing the compatibility of the fibres with regard to the resins.
It should be noted that sizing agents are also used on the carbon fibres for other objectives than that of improving the bonding thereof with an organic matrix, such as, for example, that of facilitating the handling thereof.
While the treatments mentioned above are generally relatively effective in the case of matrices obtained by thermal polymerization of resins (that is to say polymerization induced by heat), it turns out that they are not effective or insufficiently effective when the matrices are produced with resins, the polymerization of which is brought about by light radiation (visible or ultraviolet light) or ionizing radiation (β or γ radiation or X-rays).
This is because experience shows that the composites obtained with resins polymerized under radiation exhibit transverse mechanical performances which are markedly inferior to those of the better composites produced with resins polymerized by the thermal route, which is conventionally interpreted as the fact that the fibres/matrix bonding remains inadequate despite the treatments applied to the carbon fibres by the manufacturers thereof.
In point of fact, the polymerization of resins under radiation moreover exhibits a number of advantages with respect to the polymerization of resins by the thermal route, these advantages being related in particular to the possibility of operating without autoclaves and thus of more easily manufacturing composite components which are large in size or complex in structure and of obtaining much higher polymerization rates, which makes possible higher production rates for lower costs.
The Inventors thus set themselves the objective of providing a process which makes it possible to improve the adhesion of carbon fibres with regard to a polymer matrix in the case where this matrix is obtained by polymerization under radiation of a curable resin and more specifically of a resin which can be cured by chain polymerization since, in practice, the resins capable of polymerizing under radiation are resins, the polymerization of which takes place by a chain mechanism.
Furthermore, they set themselves the objective that this process be applicable to the greatest possible number of types of carbon fibres capable of being used in the manufacture of composite materials (long fibres, medium-length fibres, short fibres, oxidized fibres, sized fibres, and the like).
In addition, they set themselves the objective that the operating costs for this process be compatible with the use thereof on the industrial scale.
DESCRIPTION OF THE INVENTION
These objectives and yet others are achieved by the present invention, which provides a process for improving the adhesion of carbon fibres with regard to an organic matrix forming a composite material with these fibres, this composite material being obtained by bringing the fibres into contact with a resin which can be cured by chain polymerization and then polymerizing the resin, which process is characterized in that it comprises the grafting, to the surface of the fibres, before they are brought into contact with the resin, of groups capable of acting as chain transfer agents during the polymerization of said resin.
The carbon fibres as obtained by conventional processes for the pyrolysis of polyacrylonitrile (PAN), rayon, viscose, pitch and other oil residues are each composed of a multitude of monofilaments which can be more or less bonded to one another according to the treatments to which these fibres were subjected during the manufacture thereof.
For this reason, in that which precedes and in that which follows, the term “surface of the fibres” is understood to mean both the surface of the monofilaments themselves and the surface of assemblages resulting from the bonding of a plurality of monofilaments to one another. In the same way, the term “surface of a fibre” is understood to mean both the surface of a monofilament and that of an assemblage resulting from the bonding of several monofilaments to one another.
Furthermore, in that which precedes and in that which follows, the term “polymerization” should be understood as comprising not only the formation of polymer chains by bonding of monomers or prepolymers to one another but also the formation of a three-dimensional network by the establishment of bonds between these polymer chains, which is commonly known as crosslinking.
Thus, according to the invention, it is by grafting, to the surface of the carbon fibres, before the latter participate in the process for the manufacture of the composite material, organic groups capable of subsequently acting as chain transfer agents during the polymerization of the resin intended to form the organic matrix of the composite material that the adhesion of these fibres with regard to this matrix is enhanced.
In the current state of their studies, the Inventors believe that this increase in adhesion would be related to the fact that the groups thus grafted to the surface of the fibres will be converted, during the polymerization of the resin, to active centres (that is to say to radicals or to ions, depending upon whether the chain polymerization is of radical type or of ionic type) by reaction with growing polymer chains and that these active centres will be capable of initiating the formation of new polymer chains starting from the surface of the fibres, which would then be covalently bonded to this surface from the moment of their creation.
In other words, the polymerization of the resin would trigger the activation of the groups grafted to the surface of the fibres to give active centres, this activation being accompanied both by control of the polymerization and by the creation of covalent bonds between the fibres and the organic matrix.
This presumed mechanism can be illustrated diagrammatically in the following way:
where:
TA represents a group acting as chain transfer agent,
represents a polymer chain,
stage (a) illustrates the conversion of this group to an active centre, and stage (b) illustrates the formation of a new polymer chain starting from the surface of the fibre.
In accordance with the invention, the groups which are grafted to the surface of the carbon fibres and which are preferably all identical can be chosen from the many groups known for being capable of acting as chain transfer agents in a chain polymerization, it being understood that the selection will preferably be made of that or those which make(s) it possible to obtain a fibre/matrix bond which is the most satisfactory possible, in view of the curable resin which has to be used and/or the conditions under which the latter has to be polymerized.
In order to do this, it is entirely possible to evaluate the effect of different groups on the adhesion of carbon fibres with regard to a specific organic matrix and/or for specific polymerization conditions, for example by subjecting fibres on which one of these groups will have been grafted beforehand to a test conventionally used to assess the mechanical properties of a fibre/matrix interface, such as, for example, a loosening test of the type of that described in Example 1 below, and by comparing the results obtained for each grafted group.
Mention may in particular be made, as groups capable of acting as chain transfer agents in a chain polymerization, of carbon-based groups comprising an —I, —Br, —Cl, —F, —SH, —OH, —NH—, —NH 2 , —PH—, —PH 2 or ═S functional group and also carbon-based groups which are devoid of a heteroatom but which can give rise to radical transfer, such as, for example, optionally substituted allyl or benzyl —CH groups.
It turns out that, in the context of their studies, the Inventors have found that the grafting of carbon-based groups comprising a thiol functional group makes it possible to obtain a particularly significant improvement in the adhesion of carbon fibres, in particular with regard to matrices obtained by polymerization of epoxy acrylate resins under ionizing radiation. Consequently, carbon-based groups comprising a thiol functional group are those which it is preferable to graft in the context of the present invention.
Furthermore, in accordance with the invention, the grafting to the surface of the carbon fibres of the groups capable of acting as chain transfer agents is generally carried out by reacting functional groups present on this surface with a compound which generates, during this reaction, a group capable of acting as chain transfer agent or which comprises such a group, the choice of this compound being conditioned by the type or types of functional groups present at the surface of the fibres, which themselves depend on the treatment or treatments to which the fibres have been subjected during or on conclusion of the manufacture thereof.
Thus, for example, carbon fibres which have been subjected to an electrolytic or chemical oxidation carry, in principle, oxygen-based groups, such as hydroxyl, ketone, carboxylate or ether groups, while carbon fibres which have been subjected to sizing carry, for their part, generally epoxide groups.
It should be noted that, if it is not possible to obtain details on the type or types of functional groups carried by carbon fibres from the manufacturer, it is possible to assess the surface condition of these fibres by electron spectroscopy for chemical analysis (ESCA), also known under the name of X-ray photoelectron spectroscopy (XPS).
According to a first preferred embodiment of the process according to the invention, the grafting to the surface of the carbon fibres of the groups capable of acting as chain transfer agents is carried out by reacting functional groups present at the surface of these fibres with a cyclic organic compound which, by ring opening, becomes covalently bonded to the functional groups of the fibres and simultaneously generates a group capable of acting as chain transfer agent.
Thus, for example, in the case where it is desired to graft carbon-based groups comprising a thiol functional group to the surface of oxidized carbon fibres which comprise in particular carboxyl groups, this grafting is carried out by reacting these carboxyl groups with an episulphide which, by ring opening, becomes covalently bonded to a carboxyl functional group and simultaneously generates a group comprising a thiol functional group.
The episulphide is, for example, propylene sulphide, ethylene sulphide, cyclohexene sulphide, epithiodecane, epithiododecane or 7-thiabicyclo-[4.1.0]heptane and the reaction is advantageously carried out under hot conditions (for example, at a temperature of the order of 100° C.) in the presence of a catalyst, preferably a tertiary amine, such as triethylamine.
Furthermore, it is advantageously followed by one or more operations of washing the fibres and then by one or more operations of drying said fibres, which can be carried out according to procedures conventionally employed in the matter of washing and drying fibres and in particular carbon fibres.
According to another preferred embodiment of the process according to the invention, the grafting to the surface of the carbon fibres of the groups capable of acting as chain transfer agents is carried out by reacting functional groups present on the surface of these fibres with an organic compound which comprises a chemical functional group capable of reacting with the said functional groups and a group capable of acting as chain transfer agent.
Thus, for example, in the case where it is desired to graft carbon-based groups comprising a thiol functional group to the surface of the carbon fibres, this grafting is carried out by reacting the functional groups present at the surface of these fibres with an organic compound having a chemical functional group which is chosen as a function of the type or types of functional groups present at the surface of the fibres and a group comprising a thiol functional group.
For sized fibres rich in epoxide groups, the chemical functional group is advantageously a carboxyl or phenol functional group and the reaction is advantageously carried out under hot conditions (for example, at a temperature of 150° C.) under vacuum and in the presence of a catalyst, preferably a tertiary amine, such as dimethylaminoethyl methacrylate.
An organic compound having both a carboxyl functional group and a group comprising a thiol functional group is, for example, thiomalic acid, thioglycolic acid, thiolactic acid, 3-mercaptopropionic acid, 11-mercaptoundecanoic acid, 16-mercapto-hexadecanoic acid, 2-mercaptonicotinic acid, 6-mercaptonicotinic acid or 2-mercapto-4-methyl-5-thiazolacetic acid, while a compound having both a phenol functional group and a group comprising a thiol functional group is, for example, 2-mercaptophenol, 3-mercaptophenol, 4-mercaptophenol or 4-thiouracil.
In any case, it is within the normal competence of a person skilled in the art of the field of the coupling of chemical functional groups to know how to determine, according to the functional groups present at the surface of the carbon fibres which he intends to use, what are the compounds suitable for allowing him to graft, to the surface of these fibres, the groups of his choice and to fix the conditions under which the grafting has to be carried out in order to be effective, in particular as regards the carbon fibres/reactant(s)/catalyst(s) relative proportions which have to be used, and also the temperature and pressure parameters necessary for the satisfactory progression of this grafting.
In accordance with the invention, the curable resin can be chosen from any resin capable of curing by a chain polymerization mechanism, whether under the effect of heat or under the effect of light or ionizing radiation, this being because the Inventors have found, in the context of their studies, that the process according to the invention is effective both in the case of a thermosetting resin and of a photo- or radiation-curable resin.
However, for the reasons set out above, the resin is preferably chosen from resins which can be polymerized under radiation and in particular from resins of multiacrylates type, such as epoxy acrylates, novolac acrylates and polyurethane acrylates, bismaleimide resins and epoxide resins, epoxy acrylate resins being particularly preferred in the case where the composite material is intended for space or aeronautical applications.
Once the grafting to the surface of the fibres of the groups capable of acting as chain transfer agents has been carried out, the carbon fibres can either be used immediately in the manufacture of components made of composite materials or can be stored for the purpose of subsequent use or also be packaged for the purpose of their delivery to manufacturers of components made of composite materials. This is because the process according to the invention can be employed both by the manufacturers of carbon fibres and by the users thereof.
Another subject-matter of the invention is a process for the manufacture of a component made of composite material comprising carbon fibres and an organic matrix, which process comprises bringing the fibres into contact with a resin which can be cured by chain polymerization and then polymerizing the resin and is characterized in that it furthermore comprises the implementation of a process as described above before the fibres are brought into contact with said resin.
It is obvious that the manufacture of this component made of composite material can be carried out according to any technique known to a person skilled in the art of composite materials, such as, for example, simultaneous spray moulding, vacuum moulding, moulding by low pressure injection of resin (Resin Transfer Moulding (RTM)), low pressure “wet route” cold press moulding, compound injection moulding (Bulk Moulding Compound (BMC)), moulding by compression of preimpregnated mats (Sheet Moulding Compound (SMC)), filament winding moulding, centrifugal moulding or pultrusion moulding.
Other characteristics and advantages of the process for improving the adhesion of carbon fibres with regard to an organic matrix in accordance with the invention will become more clearly apparent on reading the remainder of the description which follows, which relates to examples of the implementation of this process and which refers to the appended drawings.
Of course, these examples are given solely by way of illustration of the subject-matter of the invention and do not under any circumstances constitute a limitation on this subject-matter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the reaction between two carboxyl functional groups situated on the surface of an oxidized and nonsized carbon fibre and propylene sulphide in the presence of a tertiary amine and shows the chemical structures of the two types of groups comprising a thiol functional group which are assumed to become attached to the surface of the fibre during this reaction.
FIG. 2A shows a negative taken with a scanning electron microscope (SEM), at a magnification of 500×, of a split in a composite material produced from an epoxy acrylate resin and oxidized and nonsized carbon fibres.
FIG. 2B shows a negative taken with an SEM, at a magnification of 3500×, of a split in a composite material produced using the same epoxy acrylate resin and the same carbon fibres as those present in the composite material of FIG. 2A but after having grafted groups comprising a thiol functional group to the surface of these fibres by the reaction illustrated in FIG. 1 .
FIG. 3 illustrates the reaction between an epoxide functional group situated at the surface of a sized carbon fibre and thiomalic acid in the presence of a tertiary amine.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
Example 1
This example relates to the grafting of groups comprising a thiol functional group to the surface of carbon fibres which have been subjected to electrolytic oxidation but which have not been subjected to any sizing.
These fibres originate from Tenax, which markets them under the reference IMS5001.
Their main chemical characteristics are collated in Table 1 below.
TABLE 1
Elemental
C
O
N
atomic ratios
83%
15%
2%
Nature and
—COR
—C═O
—COOH
distribution of
9.5%
3.1%
6.3%
the oxygen-
based groups
(as % of the
total carbon)
The grafting of the groups comprising a thiol functional group to the surface of the fibres is carried out by reacting the carboxyl functional groups present on this surface with propylene sulphide in an organic solvent and in the presence of triethylamine according to the reaction scheme represented in FIG. 1 .
The solvent used is toluene, this being because its low polarity makes it possible to limit the occurrence of undesirable side reactions.
These various compounds are used at the level of:
200 mmol of propylene sulphide,
30 mmol of triethylamine,
30 ml of toluene,
per 55 mg of carbon fibres.
The grafting reaction is carried out in a confined environment, without addition of pressure, at 100° C. and for 5 hours.
In practice, use is made of a steel reactor, of cylindrical shape, which is provided with a stirrer and a heater band which makes it possible to bring the reaction medium to and maintain it at the desired temperature. Furthermore, in order to prevent the fibres from becoming entangled around the stirrer, they are placed in the reactor by being enclosed beforehand in a nonwoven polypropylene bag which is permeable but resistant to toluene.
After reacting for 5 hours, the fibres are washed twice in an acetic acid/toluene (10/90 v/v) solution, in order to remove the triethylamine, and then washed five times in pure toluene, each washing operation being carried out in a beaker, with stirring and for 30 minutes.
The yield of the grafting reaction is assessed by subjecting the fibres to a Soxhlet extraction with water for 5 hours, so as to remove all the impurities liable to be present at the surface of the fibres, and by then carrying out an ESCA/XPS analysis of this surface. This analysis shows the proportion of the sulphide atoms present at the surface of the fibres as 3%.
The effect of the grafting of groups comprising a thiol functional group on the adhesion of the fibres with regard to a matrix obtained by polymerization of an epoxy acrylate resin, in the case in point the resin EB600 from UCB Chemicals, is for its part assessed by a loosening test.
In brief, this loosening test consists in immersing the end of a monofilament in a microdrop of resin, in bringing about the polymerization of the resin at ambient temperature and under an electron beam and in then exerting a tensile stress on the other end of the monofilament, at the rate of 1 mm/min, while keeping the drop of resin stationary.
The tensile force is recorded over time. The maximum tensile force recorded is regarded as the force necessary for the loosening of the monofilament from the cured resin drop.
The InterFacial Shear Strength (IFSS) is determined using the following formula:
τ = σ fd 2 L = F 2 π rL
in which:
d represents the diameter of the monofilament (in metre),
r represents the radius of the monofilament (in metre),
L represents the length of monofilament initially inserted into the drop of resin (in metre),
F represents the force necessary for the loosening of the monofilament from the cured resin drop (in newton), and
σ
f
=
F
π
r
2
(
in
newton
/
m
2
)
.
The loosening test is carried out on several monofilaments of IMS5001 fibres which have been grafted with groups comprising a thiol functional group and several monofilaments of IMS5001 fibres which have not been grafted, so as to be meaningful.
The results show that the IFSS is 59±3 MPa in the case where the IMS5001 fibres were grafted to groups comprising a thiol functional group, whereas it is only 49±4 MPa in the case where the IMS5001 fibres were not grafted.
The IFSS is thus increased by 20% by the presence of thiol functional groups on the surface of the fibres.
The positive effect of the grafting of the groups comprising a thiol functional group on the fibres/matrix adhesion is furthermore confirmed by an SEM analysis of splits in composite materials comprising a matrix obtained by polymerization of EB600 resin and IMS5001 fibres which are or are not grafted with groups comprising a thiol functional group.
These composite materials are produced in the form of unidirectional sheets by:
impregnation of the fibres with the resin (degree of impregnation 40% by weight); manufacture of unidirectional plies (12 plies) by winding the impregnated fibres around a flat mandrel; assembling the plies by drape moulding and compacting; polymerization under vacuum at ambient temperature by 4 passes at 25 kGy.
As is shown in FIG. 2B , which corresponds to a negative taken at a magnification of 3500× of a split in a composite material including IMS5001 fibres grafted with groups comprising a thiol functional group, these fibres exhibit resin residues attached at their surface which are not found on the fibres of a composite material including IMS5001 fibres not grafted with groups comprising a thiol functional group ( FIG. 2A ) and which testify to better bonding between the fibres and the epoxy acrylate matrix.
Example 2:
This example for its part relates to the grafting of the group comprising a thiol functional group to the surface of sized carbon fibres.
These fibres originate from Toray, which markets them under the reference T800H40.
They exhibit a sizing agent of epoxide type and more specifically of bisphenol A diglycidyl ether (BADGE) type, this being because these fibres are intended to be used mainly with epoxide resins.
The groups comprising a thiol functional group are grafted to the surface of fibres by reacting the epoxide functional groups present on this surface with thiomalic acid in the presence of dimethylaminoethyl methacrylate according to the reaction scheme represented in FIG. 3 . The solvent used is methyl ethyl ketone.
To do this, the fibres, in the form of a bobbin, are impregnated with a mixture of thiomalic acid and of amine, in a molar ratio of the amine functional groups to the carboxyl functional groups of 0.5%, diluted to 0.7% by weight in methyl ethyl ketone, and then the impregnated bobbin is subjected to a heat treatment at 150° C. for 30 minutes, after a rise in temperature over 45 minutes.
The effect of the grafting of the groups comprising a thiol functional group on the adhesion of the fibres with regard to a matrix obtained by polymerization of an epoxy acrylate resin, in a case in point the EB600 resin, is assessed by subjecting composite materials, produced according to a protocol analogous to that described in Example 1 from this resin and T800H40 fibres grafted or not grafted with groups comprising a thiol functional group, to a transverse bending test according to Airbus Standard IGC.04.06.245 or Standard EN 2582.
The results show that the bending σ2 is 70 MPa in the case where the T800H40 fibres were grafted with groups comprising a thiol functional group, whereas it was only 25 MPa in the case where the T800H40 fibres were not grafted.
Documents Cited
[1] JP-A-3076869
[2] EP-A-1 484 435
[3] EP-A-0 640 702
[4] JP-B- 2002327374
[5] Wu et al., Carbon, 34, 59-67, 1996
[6] Tsubokawa, Carbon, 31, 1257-1263, 1993 | The invention relates to a process for improving the adhesion of carbon fibres with regard to an organic matrix forming a composite material with these fibres, this composite material being obtained by bringing the fibres into contact with a resin which can be cured by chain polymerization and then polymerizing the resin, which process is characterized in that it comprises the grafting, to the surface of the fibres, before they are brought into contact with the resin, of groups capable of acting as chain transfer agents during the polymerization of said resin.
Fields of application: aeronautical, aerospatial, railway, ship building and automobile industries but also the armaments industry, the industry of sports and leisure articles, and the like. | 3 |
RELATED APPLICATIONS
This application is a continuation, claiming the benefit under 35 U.S.C. §120, of U.S. patent application Ser. No. 10/970,617, titled “TRANSCRIPTION DATA SECURITY,” filed on Oct. 21, 2004, the content of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Healthcare costs in the United States account for a significant share of the GNP. The affordability of healthcare is of great concern to many Americans. Technological innovations offer an important leverage to reduce healthcare costs.
Many Healthcare institutions require doctors to keep accurate and detailed records concerning diagnosis and treatment of patients. Motivation for keeping such records include government regulations (such as Medicare and Medicaid regulations), desire for the best outcome for the patient, and mitigation of liability. The records include patient notes that reflect information that a doctor or other person adds to a patient record after a given diagnosis, patient interaction, lab test or the like.
Record keeping can be a time-consuming task, and the physician's time is valuable. The time required for a physician to hand-write or type patient notes can represent a significant expense. Verbal dictation of patient notes offers significant time savings to physicians, and is becoming increasingly prevalent in modern healthcare organizations.
Over time, a significant industry has evolved around the transcription of medical dictation. Several companies produce special-purpose voice mailbox systems for storing medical dictation. These centralized systems hold voice mailboxes for a large number of physicians, each of whom can access a voice mailbox by dialing a phone number and putting in his or her identification code. These dictation voice mailbox systems are typically purchased or shared by healthcare institutions. Prices can be over $100,000 per voice mailbox system. Even at these prices, these centralized systems save healthcare institutions vast sums of money over the cost of maintaining records in a more distributed fashion.
Using today's voice mailbox medical dictation systems, when a doctor completes an interaction with a patient, the doctor calls a dictation voice mailbox, and dictates the records of the interaction with the patient. The voice mailbox is later accessed by a medical transcriptionist who listens to the audio and transcribes the audio into a text record. The playback of the audio data from the voice mailbox may be controlled by the transcriptionist through a set of foot pedals that mimic the action of the “forward”, “play”, and “rewind” buttons on a tape player. Should a transcriptionist hear an unfamiliar word, the standard practice is to stop the audio playback and look up the word in a printed dictionary.
The medical transcriptionist's time is less costly for the hospital than the doctor's time, and the medical transcriptionist is typically much more familiar with the computerized record-keeping systems than the doctor is, so this system offers a significant overall cost saving to the hospital.
The information dictated by the doctor often includes sensitive or confidential information, such as patient name, age, visit dates, medical record numbers, account numbers, referring physicians, consulting physicians, and other provider names and addresses, for example. Furthermore, recent federal regulations under the Health Insurance Portability and Accountability Act (HIPAA) increase the importance of maintaining the confidentiality of patient information. For example, HIPAA describes data called “Protected Health Information (PHI)”. Protected Health Information includes medical records data in which the patient is identified. As a result of this Act, many security measures are being created to protect this data.
SUMMARY OF THE INVENTION
Embodiments of the invention may provide security that is useful for medical records documents that include patient identification material. A mechanism may be provided that permits documents to be separated from the patient identification during transmission. Thus, an interceptor of a document during transmission will preferably not have enough information to identify the patient to which the document refers. Even if a document and its patient identification information are both intercepted, determining that the two portions of information belong with each other may be difficult. Security may be further enhanced by separating the patient identifying material from the text of the document.
In general, in an aspect, the invention provides a computer program product for use with dictated medical patient information, the computer program product residing on a computer-readable medium and comprising computer-readable instructions for causing a computer to analyze the dictated information, identify likely confidential information in the dictated medical patient information, and treat the likely confidential information disparately from likely non-confidential information in the dictated medical patient information.
Embodiments of the invention may include one or more of the following features. The computer program can be configured to cause the computer to restrict access to the likely confidential information. The instructions for causing the computer to treat the likely confidential information disparately from likely non-confidential information can cause the computer to store the likely confidential information and the likely non-confidential information such that which information is the likely confidential information is discernable. The instructions for causing the computer to treat the likely confidential information disparately from likely non-confidential information can also cause the computer to store a confidential indication in association with the likely-confidential information. The instructions for causing the computer to treat the likely confidential information disparately from likely non-confidential information can further cause the computer to transmit the likely confidential information separately from the likely non-confidential information to a communication network. The instructions for causing the computer to transmit the likely confidential information separately from the likely non-confidential information to a communication network can cause the computer to transmit likely confidential audio dictated information separately from likely non-confidential audio dictated information and to transmit likely confidential transcribed textual information corresponding to the likely confidential audio information separately from likely non-confidential transcribed textual information corresponding to the likely non-confidential audio dictated information.
Embodiments of the invention may further include one or more of the following features. The instructions for causing the computer to identify likely confidential information in the dictated medical patient information can cause the computer to identify particular phrases, containing at least one word, as the likely confidential information. The instructions for causing the computer to identify likely confidential information in the dictated medical patient information can further cause the computer to identify a boundary between a body of a transcribed document associated with the dictated information and at least one of a header and a footer of the transcribed document. The instructions for causing the computer to identify the boundary can further cause the computer to apply a statistical trigger model to the dictated information. The instructions for causing the computer to identify the boundary can also cause the computer to search for trigger phrases, of at least one word, associated with the boundary and compare boundary likelihoods associated with found trigger phrases. The instructions for causing the computer to identify the boundary can cause the computer to determine boundary likelihoods associated with the found trigger phrases by analyzing positions of the found trigger phrases in the dictated information relative to a beginning or an end of the dictated information.
In general, in another aspect, the invention provides a computer program product for use with text transcribed from audio information, the computer program product residing on a computer-readable medium and comprising computer-readable instructions for causing a computer to differentiate between a first portion and a second portion of the text, display the first portion of the text transcribed from audio information, inhibit the second portion of the text from being displayed, and display an indication that the second portion of the text exists.
Embodiments of the invention may include one or more of the following features. The indication that the second portion of the text exists can be a box. The box can be of a fixed size regardless of an amount of text contained in the second portion of the text. The indication that the second portion of the text exists can be an audible indicator. The instructions can be configured to cause the computer to display the indication in a location within the text using a token-alignment file that associates portions of the audio information with portions of the text.
Embodiments of the invention may further include one or more of the following features. The computer product may further include instructions for displaying the second portion of the text in response to a second-portion request for display of the second portion, distinct from a text request for display of the transcribed text. The computer product can include instructions for causing the computer to display the second portion of the text in response to provision of authorization information. Further, the computer product can include instructions for causing the computer to securely store the second portion of the text.
In general, in another aspect, the invention provides a method of processing text transcribed from an audio file regarding a patient, the method comprising displaying a portion of the transcribed text containing non-confidential patient information on a monitor, playing portions of an audio file associated with the transcribed text, and inhibiting a portion of the transcribed text containing confidential patient information from being displayed on the monitor.
Embodiments of the invention can include one or more of the following features. The inhibiting can comprise displaying an indication on the monitor that confidential information is being concealed. The indication can be disposed at a location within the transcribed text corresponding to where the confidential information belongs in the text. The indication can comprise a shaded box. The box can be of a fixed size regardless of an amount of confidential information being concealed. The indication can be an alias for the confidential information. The method can further comprise displaying the confidential information in response to a request to display the confidential information that is distinct from an initial request to display the transcribed text.
In general, in another aspect, the invention provides a method of processing a medical patient dictation, the method comprising analyzing the dictated information, identifying likely confidential information in the dictated medical patient information, and treating the likely confidential information disparately from likely non-confidential information in the dictated medical patient information.
Embodiments of the invention can include one or more of the following features. The method may further comprise labeling a portion of the dictated information to distinguish the likely confidential information from the likely non-confidential information. The method may further comprise inhibiting access to the likely confidential information. The method may also comprise transmitting the likely confidential information and the likely non-confidential information separately over a communication network. The method still further may comprise identifying a boundary between a body of a transcribed document associated with the medical patient dictation and at least one of a header and a footer of the transcribed document. Identifying the boundary can comprise applying a statistical trigger model to the medical patient dictation. Applying the statistical trigger model may comprise searching for trigger phrases, of at least one word, associated with the boundary and comparing boundary likelihoods associated with found trigger phrases.
Aspects of the invention may include one or more of the following capabilities. Confidential information is removed or concealed from the body of a medical record document. The confidential information is accessible to authorized users by listening to audio associated with a medical record document, or by accessing a secure database. Separate audio files having various levels of confidential information can be transmitted and/or stored separately from non-confidential information. Separate text files having various levels of confidential information can be transmitted and/or stored separately from non-confidential transcribed information. The confidential information is secured by associating it with a medical record document via a unique identifier. Medical records information contained in clinician audio dictations are de-identified from the resulting transcriptions. Transcribed information can be added or changed at a transcription device without revealing the confidential information. The cost of medical transcription is reduced. Information associated with a patient's identity can be inhibited from being paired with information of a patient's medical exam by an interceptor of information transmitted over a public network.
These and other capabilities of the invention, along with the invention itself, will be more fully understood after a review of the following figures, detailed description, and claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a simplified diagram of a system for transcribing dictations and editing corresponding transcriptions.
FIG. 2 is a simplified block diagram of an editing device of the system shown in FIG. 1 .
FIG. 3-5 are portions of a transcribed dictation showing concealment of a portion of the text.
FIG. 6 is a block flow diagram of a process of extracting information from an automatic transcription device.
FIG. 7 is a block flow diagram of a process of producing and editing a transcription.
FIG. 8 is a block flow diagram of a process of editing information extracted from an automatic transcription device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of the invention can provide a secure database for the storage of confidential information related to documents associated with a digital audio signal of speech to be transcribed. Confidential information can be removed from the body of a medical records document. Authorized users access the confidential information by listening to the audio associated with the document. Confidential information is stored separately in textual form in a medical records database, and associated with a medical record document. Confidential information is concealed from view in a text document being edited. The private information is accessible to authorized persons via a login or a password. Other embodiments are within the scope of the disclosure.
Referring to FIG. 1 , a system 10 for transcribing audio and editing transcribed audio includes a speaker/person 12 , a communications network 14 , a voice mailbox system 16 , an administrative console 18 , an editing device 20 , a communications network 22 , a database server 24 , a communications network 26 , and an automatic transcription device 30 . Here, the network 14 is preferably a public switched telephone network (PSTN) although other networks, including packet-switched networks could be used, e.g., if the speaker 12 uses an Internet phone for dictation. The network 22 is preferably a packet-switched network such as the global packet-switched network known as the Internet. The network 26 is preferably a packet-switched, local area network (LAN). Other types of networks may be used, however, for the networks 14 , 22 , 26 , or any or all of the networks 14 , 22 , 26 may be eliminated, e.g., if items shown in FIG. 1 are combined or eliminated.
Preferably, the voice mailbox system 16 , the administrative console 18 , and the editing device 20 are situated “off site” from the database server 24 and the automatic transcription device 30 . These systems/devices 16 , 18 , 20 , however, could be located “on site,” and communications between them may take place, e.g., over a local area network. Similarly, it is possible to locate the automatic transcription device 30 off-site, and have the device 30 communicate with the database server 24 over the network 22 .
The network 14 is configured to convey dictation from the speaker 12 to the voice mailbox system 16 . Preferably, the speaker 12 dictates into an audio transducer such as a telephone, and the transduced audio is transmitted over the telephone network 14 into the voice mailbox system 16 , such as the Intelliscript™ product made by eScription™ of Needham, Mass. The speaker 12 may, however, use means other than a standard telephone for creating a digital audio file for each dictation. For example, the speaker 12 may dictate into a handheld PDA device that includes its own digitization mechanism for storing the audio file. Or, the speaker 12 may use a standard “dictation station,” such as those provided by many vendors. Still other devices may be used by the speaker 12 for dictating, and possibly digitizing the dictation, and sending it to the voice mailbox system 16 .
The voice mailbox system 16 is configured to digitize audio from the speaker 12 to produce a digital audio file of the dictation. For example, the system 16 may use the Intelliscript™ product made by eScription.
The voice mailbox system 16 is further configured to prompt the speaker 12 to enter an identification code and a worktype code. The speaker 12 can enter the codes, e.g., by pressing buttons on a telephone to send DTMF tones, or by speaking the codes into the telephone. The system 16 may provide speech recognition to convert the spoken codes into a digital identification code and a digital worktype code. The mailbox system 16 is further configured to store the identifying code and the worktype code in association with the dictation. The system 16 preferably prompts the speaker 12 to provide the worktype code at least for each dictation related to the medical field. The worktype code designates a category of work to which the dictation pertains, e.g., for medical applications this could include Office Note, Consultation, Operative Note, Discharge Summary, Radiology report, etc. The worktype code may be used to refine speed settings, such that settings may be specific not only to speaker-transcriptionist pairings, but further to worktype of dictations provided by the speaker, and/or to other parameters or indicia. The following discussion, however, focuses on using only speaker-transcriptionist pairings.
The voice mailbox system 16 is further configured to transmit the digital audio file and speaker identification code over the network 22 to the database server 24 for storage. This transmission is accomplished by the system 16 product using standard network transmission protocols communicating with the database server 24 .
The database server 24 is configured to store the incoming data from the voice mailbox system 16 , as well as from other sources. For example, information such as patient Medical Record Number (MRN), date of dictation, date of encounter, account number, and other information can originate from the voice mailbox system 16 , from a hospital billing system, or from another source. The database server 24 may include the EditScript Server™ database product from eScription. Software of the database server is configured to produce a database record for the dictation, including a file pointer to the digital audio data, and a field containing the identification code for the speaker 12 . If the audio and identifying data are stored on a PDA, the PDA may be connected to a computer running the HandiScript™ software product made by eScription that will perform the data transfer and communication with the database server 24 to enable a database record to be produced for the dictation.
Preferably, all communication with the database server 24 is intermediated by a “servlet” application 32 that includes an in-memory cached representation of recent database entries. The servlet 32 is configured to service requests from the voice mailbox system 16 , the automatic transcription device 30 , the editing device 20 , and the administrative console 18 , reading from the database when the servlet's cache does not contain the required information. The servlet 32 includes a separate software module that helps ensure that the servlet's cache is synchronized with the contents of the database. This helps allow the database to be off-loaded of much of the real-time data-communication and to grow to be much larger than otherwise possible. For simplicity, however, the below discussion does not refer to the servlet, but all database access activities may be realized using the servlet application 32 as an intermediary.
The automatic transcription device 30 may access the database 40 in the database server 24 over the data network 26 for transcribing the stored dictation. The automatic transcription device 30 uses an automatic speech recognition (ASR) device (e.g., software) to produce a draft transcription for the dictation. An example of ASR technology is the AutoScript™ product made by eScription that also uses the speaker and, optionally, worktype identifying information to access speaker and speaker-worktype dependent ASR models with which to perform the transcription.
The device 30 transmits the draft transcription over the data network 26 to the database server 24 for storage in the database and to be accessed, along with the digital audio file, by the editing device 20 .
The device 30 is further configured to affect the presentation of the draft transcription. The device 30 , as part of speech recognition or as part of post-processing after speech recognition, can add or change items affecting document presentation such as formats, abbreviations, and other text features. The device 28 includes a speech recognizer and may also include a post-processor for performing operations in addition to the speech recognition, although the speech recognizer itself may perform some or all of these additional functions.
Automatic speech recognition (ASR) models in the device 30 used to produce draft transcriptions include different types of grammars for recognizing the speaker's dictation. The grammars can be, for example, generic, specific, or intermediate. Generic grammars are designed to recognize speech from a random speaker. Specific grammars are designed/adapted for a particular speaker, either being designed from scratch for the speaker 12 or having been adapted from a more general grammar in response to previous dictations and edited transcriptions. An example of an intermediate grammar is a grammar designed not for a particular speaker, but for speakers that are likely to follow a particular pattern. For example, doctors from a particular institution may be instructed to dictate patient records with a particular format, and the grammar can be designed to improve recognition based on knowledge of expected phrases and/or organization of the patient record.
The automatic transcription device 30 is further configured to identify confidential portions of dictations, including particular data, header regions, and footer regions. Confidential/private patient information includes, e.g., patient name, medical record number, and/or other information from which a patient's identity may be discerned, at least to reasonable (or unacceptable) degree of certainty. The ASR models can be used to identify particular data, such as portions of the dictation that includes the provider name, patient name, patient names spelled out, date of encounter, worktype and/or Medical Record Number (MRN). The device 30 also preferably is able to identify header and footer portions of a dictation as these introductory and closing portions often contain confidential information. The device 30 can analyze the text for the manner in which the speaker begins the dictation. For example, the device 30 may include a grammar such as, “This is Dr. <PROVIDER NAME> dictating an office note on <PATIENT NAME>, medical record number <MRN>. Date of visit is <DATE OF ENCOUNTER>”. The device 30 can additionally analyze the text for the manner in which a speaker 12 begins the body of a dictation, which indicates the completion of the header. For example, the device 30 may include a grammar such as, “CHIEF COMPLAINT: Mr. <PATIENT_LAST_NAME> comes in today complaining of chest pain.” The device 30 may also include a grammar related to the manner in which a speaker 12 dictates the end of a note, or footer. For example, the device 30 may include a grammar such as, “This is <PROVIDER NAME>. Please send a copy to <CONTACT1> and <CONTACT2>, as well as to my office.”
Preferably, the device 30 uses the grammars to identify the location of the header and footer in a dictation. These grammars provide trigger words or phrases that indicate the boundary from the header to the body of the dictation or from the body of the dictation to the footer. Examples of additional end-of-header (i.e. beginning-of-body) trigger phrases include: “The patient is a”, followed by an age; “The patient comes in today complaining of . . . ”; “history”. Examples of footer (i.e. end-of-body) trigger phrases include: “That's all”; “Please send a copy of this to . . . ”. In many cases, these triggers by themselves will be sufficient to reliably identify the end of the header and beginning of the footer. These phrases may, however, be supplemented by a statistical trigger model to help identify the boundaries. The model is statistical in that it determines the likelihood of one or more locations being a header/body or body/footer transition, and uses the most likely location as the actual location of the transition. A statistical trigger model can be used alone, or can be combined with a duration model, such as a specified number of words, for the header, body, and footer in order to resolve ambiguities in determining whether particular grammar is a part of the header or the footer. For example, a statistical analysis may include that the phrase “Please send a copy to . . . ” has a 90% probability of being a boundary phrase when it occurs within the final thirty words of a dictation. The statistical trigger model may be constrained by the structure of the document, for example, requiring that the footer follows the body, which follows the header.
The header and footer region of the dictation can alternatively be identified by the transcription device 30 in one of the following ways. The header and footer may be identified by using an instance of a listened-to/transcribed header/footer to form the grammar which is used to remove the header/footer from subsequent dictations. A catalog of grammars from a database of providers may be employed to identify headers/footers. The grammars can be scored to determine likely instances of headers/footers in different grammars. A generalized search for words associated with tags in the token-alignment file, discussed below, can be conducted, and may be narrowed using the current date or medical record numbers.
In the event that speech recognition errors occur, a) known or common errors from speech recognition can be explicitly included; b) “wild-cards” that model words which are known to cause recognition errors can be utilized. For example, instead of “the patient comes in today complaining of”, the grammar might be “* patient comes * complaining *”, since the non-wildcarded words are known to be reliably recognized. The identified confidential information, including header and footer information, are stored separately and treated differently than non-confidential information for the editing process discussed below. Portions of the dictation that include confidential information can be stored separately from non-confidential information in the database 40 . For example, the database 40 may include multiple databases, and the confidential information may be stored in a database separate from a database in which non-confidential information is stored. Confidential information can be stored in the same database, but in a separate portion (e.g., a separate file), as non-confidential information. The confidential information is stored separately in that access to the confidential information is inhibited/restricted such that a user that has access to non-confidential information in the database 40 does not necessarily have access to the confidential information. For example, access to the confidential information may require a password or other security measure. Further, the confidential information that appears in the body of the dictation document is tagged, e.g., to help inhibit access to the confidential information even if it is not contained in the header or footer. Additional security can include encrypting the data before sending the data to the user terminal for the editing process, or encrypting the data while the data is en route to the user terminal.
The transcription device 30 is further configured to produce a token-alignment file that synchronizes the audio with the corresponding text. This file comprises a set of token records, with each record preferably containing a token, a begin index, and an end index. The token comprises a character or a sequence of characters that are to appear on the screen during a word-processing session, or one or more sounds that may or may not appear as text on a screen. A begin index comprises an array reference into the audio file corresponding to the place in the audio file where the corresponding token begins. The end index comprises an array reference into the digital audio file corresponding to the point in the audio file where the corresponding token ends. As an alternative, the end index may not exist separately, with it being assumed that the starting point of the next token (the next begin index) is also the ending point of the previous token. The transcription device 30 can store the token-alignment file in the database 40 .
The token-alignment file may contain further information, such as a display indicator and/or a playback indicator. The display indicator's value indicates whether the corresponding token is to be displayed, e.g., on a computer monitor, while the transcription is being edited. Using non-displayed tokens can help facilitate editing of the transcription while maintaining synchronization between on-screen tokens and the digital audio file. For example, a speaker may use an alias, e.g., for a heading, and standard heading (e.g., Physical Examination) may be displayed while the words actually spoken by the speaker (e.g., “On exam today”) are audibly played but not displayed as text (hidden). The playback indicator's value indicates whether the corresponding token has audio associated with the token. Using the playback indicator can also help facilitate editing the transcription while maintaining synchronization between on-screen tokens and the digital audio file. The playback indicator's value may be adjusted dynamically during audio playback, e.g., by input from the transcriptionist. The adjustment may, e.g., cause audio associated with corresponding tokens (e.g., hesitation words) to be skipped partially or entirely, that may help increase the transcriptionist's productivity.
The tokens stored in the token-alignment file may or may not correspond to words. Instead, a token may represent one or more characters that appear on a display during editing of the transcription, or sounds that occur in the audio file. Thus, the written transcription may have a different form and/or format than the exact words that were spoken by the person 12 . For example, a token may represent conventional words such as “the,” “patient,” or “esophagogastroduodenoscopy,” multiple words, partial words, abbreviations or acronyms, numbers, dates, sounds (e.g., a cough, a yawn, a bell), absence of sound (silence), etc. For example, the speaker 12 may say “USA” and the automatic transcription device 30 may interpret and expand this into “United States of America.” In this example, the token is “United States of America” and the begin index would point to the beginning of the audio signal for “USA” and, if the token-alignment file uses end indexes, the end index would point to the end of the audio signal “USA.” As another example, the speaker 12 might say “April 2 of last year,” and the text might appear on the display as “04/02/2003.” The tokens, however, can synchronize the text “04/02/2003” with the audio of “April 2 of last year.” As another example, the speaker 12 might say “miles per hour” while the text is displayed as “MPH.” Using the tokens, the speech recognizer 30 , or a post-processor in or separate from the device 30 , may alter, expand, contract, and/or format the spoken words when converting to text without losing the audio synchronization. Tokens preferably have variable lengths, with different tokens having different lengths.
The token-alignment file provides an environment with many features. Items may appear on a screen but not have any audio signal associated with them (e.g., implicit titles and headings). Items may have audio associated with them and may appear on the screen but may not appear as words (e.g., numeric tokens such as “120/88”). Items may have audio associated with them, appear on the screen, and appear as words contained in the audio (e.g., “the patient showed delayed recovery”). Multiple words may appear on the screen corresponding to audio that is an abbreviated form of what appears on the screen (e.g., “United States of America” may be displayed corresponding to audio of “USA”). Items may have audio associated with them but not have corresponding symbols appear on the screen (e.g., a cough, an ending salutation such as “that's all,” commands or instructions to the transcriptionist such as “start a new paragraph,” etc.).
In addition, in the token-alignment file, XML tags, such as <Header>, </Header> and <Footer>, </Footer> are included as zero-duration, non-playable, non-displayable records. Tags are also added around other data contained in the headers and footers. For example, tags can be added to identify <MRN>, <DATE OF ENCOUNTER>, and <CONTACTS>. In the body of the dictation, tags are added around recognized information, including but not limited to <PATIENT NAME>, <PROVIDER NAME>, and <CONTACTS>. The tags allow identification of words in the dictation that contain specific information. The specified words can be manipulated due to the tag assigned to the words. For example, the words having specified tags associated with private/confidential information can be blocked from view in a transcribed document. At the time of editing, tagged words can be obfuscated. For example, <PATIENT NAME> can be changed to “the patient” or to “Mr. ???” for instances of its occurrence throughout the transcribed document to protect the identity of the patient.
Referring further to FIG. 1 , the editing device 20 is configured to be used by a transcriptionist to access and edit the draft transcription stored in the database of the database server 24 . The editing device 20 includes a computer (e.g., display, keyboard, mouse, monitor, memory, and a processor, etc.), an attached foot-pedal, and appropriate software such as the EditScript™ software product made by eScription. The transcriptionist can log onto the database server 24 with a password. The transcriptionist can request a dictation job by, e.g., clicking on an on-screen icon. The request is serviced by the database server 24 , which finds the dictation for the transcriptionist, and transmits the corresponding header, footer, and body audio files and the draft transcription text files. The transcriptionist edits the draft using the editing device 20 and sends the edited transcript back to the database server 24 . For example, to end the editing the transcriptionist can click on an on-screen icon button to instruct the editing device 20 to send the final edited document to the database server 24 via the network 22 , along with a unique identifier for the transcriptionist. With the data sent from the editing device 20 , the database in the server 24 contains, for each dictation: a speaker identifier, a transcriptionist identifier, a file pointer to the digital audio signal, and a file pointer to the edited text document.
The edited text document can be transmitted directly to a customer's medical record system or accessed over the data network 22 from the database by the administrative console 18 . The console 18 may include an administrative console software product such as Emon™ made by eScription.
Referring to FIG. 2 , components of the editing device 20 , e.g., a computer, include a database interaction module 41 , a user interface 42 , non-confidential information storage 43 , confidential information storage 45 , a word processor module 44 , an audio playback module 46 , an audio file pointer 48 , a cursor module 50 , a monitor 52 , and an audio device 54 . A computer implementing portions of the editing device 20 includes a processor and memory that stores appropriate computer-readable, computer-executable software code instructions that can cause the processor to execute appropriate instructions for performing functions described. The monitor 52 and audio device 54 , e.g., speakers, are physical components while the other components shown in FIG. 2 are functional components that may be implemented with software, hardware, etc., or combinations thereof. The audio playback device 46 , such as a SoundBlaster® card, is attached to the audio output transducer 54 such as speakers or headphones. The transcriptionist can use the audio device 54 (e.g., headphones or a speaker) to listen to audio and can view the monitor 52 to see the corresponding text. The transcriptionist can use the foot pedal 66 , the keyboard 62 , and/or the mouse 64 to control the audio playback. The database interaction, audio playback, and editing of the draft transcription is accomplished by means of the appropriate software such as the EditScript Client™ software product made by eScription. The body of dictation files 43 and the header/footer data files are sent to the user interface from the database. The editing software is loaded on the editing device computer 20 and configured appropriately for interaction with other components of the editing device 20 . The editing software can use a standard word processing software library, such as that provided with Microsoft Word®, in order to load, edit and save documents corresponding to each dictation.
The editing software includes the database interaction module 41 , the user interface module 42 , the word processing module 44 , the audio playback module 46 , the audio file pointer adjustment module 48 and the multi-cursor control module 50 . The interaction module 41 regulates communications between database server 24 and the editing device 20 via the network 22 . The control module 50 regulates the interaction between the interface module 42 and the word processors 44 , the audio playback modules 46 , and the audio file pointer 48 . The control module 50 regulates the flow of actions relating to processing of a transcription, including playing audio and providing cursors in the transcribed text. The user interface module 42 controls the activity of the other modules and includes keyboard detection 56 , mouse detection 58 , and foot pedal detection 60 sub-modules for processing input from a keyboard 62 , a mouse 64 , and a foot-pedal 66 . The foot pedal 66 is a standard transcription foot pedal and is connected to the editing device computer through the computer's serial port. The foot pedal 66 preferably includes a “fast forward” portion and a “rewind” portion.
The transcriptionist is permitted to access dictations downloaded to the user interface module 42 based on provider (or groups of providers) and patient identification. The transcriptionist logs onto the user interface module 42 with a logon name and a password so that dictations assigned to a particular transcriptionist are visible in a work queue. The transcriptionist can request a job from the database by selecting on-screen icon with the mouse 64 . The user interface module 42 interprets this mouse click and invokes the database interaction module 41 to request the next job from the database 40 . The database server 24 ( FIG. 1 ) responds by transmitting the audio data files, the draft transcription files, and the token-alignment files to the user interaction module 42 . The audio for confidential information is preferably transmitted to the device 20 separately from the audio for the non-confidential information. Likewise, the text for confidential information is preferably transmitted to the device 20 separately from the text for the non-confidential information. The confidential information is stored in the confidential information storage 43 separate from the non-confidential information storage 45 . The confidential information storage 43 can be access-restricted, e.g., by a password and/or other security feature(s). Also, portions of the confidential information can be restricted from access by a particular user, rather than all of the confidential information. With this downloaded information, the editing software can initialize a word-processing session by loading the draft text into the word processing module 44 . Audio information is accessed through function calls of the editing program while the dictation is being edited.
The audio playback module 46 is configured to play the audio file associated with the body of the dictation 43 and the audio associated with the header/footer 45 . The transcriptionist accesses the audio files 43 and 45 when prepared for editing. For initial playback, the module 46 plays the audio file sequentially. The playback module 46 can, however, jump to audio corresponding to an indicated portion of the transcription and begin playback from the indicated location. For example, the playback module 46 can request the header audio and begin playback of the header. The location may be indicated by a transcriptionist using appropriate portions of the editing device 20 such as the keyboard 62 , or the mouse 64 . For playback that starts at an indicated location, the playback module 46 uses the token-alignment file to determine the location in the audio file corresponding to the indicated transcription text. Since many audio playback programs play audio in fixed-sized sections (called “frames”), the audio playback module 46 may convert the indicated begin index to the nearest preceding frame for playback. For example, an audio device 54 may play only frames of 128 bytes in length. In this example, the audio playback module uses the token-alignment file to find the nearest prior starting frame that is a multiple of 128 bytes from the beginning of the audio file. Thus, the starting point for audio playback may not correspond precisely to the selected text in the transcription.
The transcriptionist can review and edit a document by appropriately controlling portions of the editing device 20 . The transcriptionist can regulate the playback using the foot pedal 66 , and listen to the audio corresponding to the text as played by the playback module 46 and converted to sound by the audio device 54 . Further, the transcriptionist can move a cursor to a desired portion of the display of the monitor 52 using the keyboard 62 and/or mouse 64 , and can make edits at the location of the cursor using the keyboard 62 and/or mouse 64 .
The user interface 42 downloads the text of the document to the word processor 44 according to the editing program, which provides restricted access and display of header/footer data and other confidential information. If the transcriptionist positions the cursor for playback of confidential information, then the transcriptionist can be prompted to enter a password, or otherwise fulfill a security measure (e.g., provide bioinformatic information such as a fingerprint) in order to be provided with the text and/or audio corresponding to the confidential information.
Referring to FIGS. 3-5 , confidential information can be obscured/hidden from view absent authorization. As shown in FIG. 3 , a header 70 and a footer data 72 appear as gray boxes on the monitor 52 . Thus, the confidential data in the header 70 and the footer 72 is not apparent to the user, but is hidden from view. The gray box is preferably of a standard size. As shown in FIG. 4 , confidential information contained in a body 74 of a document 76 is hidden with gray boxes 78 , 79 . The boxes 78 , 79 indicate data that have been tagged as confidential, and have been removed from appearing in the body of the text while the document is edited. The boxes 78 , 79 are preferably of a standard size to help prevent providing insight into confidential information (e.g., a length of a physician's name). In FIG. 4 , the blocked access box 78 indicating a physician's name has been blocked from view, although the name may be presented to the transcriptionist through the audio playback of the dictation. The blocked access boxes 78 , 79 allow presentation of the body of a document while concealing confidential information from a viewer. The blocked access boxes 78 , 79 may be interactive, allowing an authorized transcriptionist to edit data in or check data that appears in the blocked access block 78 during editing functions. Data entered or reviewed in the boxes 78 , 79 may include patient name, provider name, MRN, contacts, etc. Further, as shown in FIG. 4 and FIG. 5 , techniques other than gray boxes may be used for concealing confidential information, such as using a generic name 80 (“Patient X”) in lieu of actual confidential information. Other generic names include “the patient,” “Mr. ??,” etc.
A second hot key sequence is used by the transcriptionist to reveal recognized words in the body of the document which have been obfuscated by internal tags. The transcriptionist may use the hot key sequence to call forth and edit the protected language.
While the transcriptionist is editing the document, the user interface module 42 can service hardware interrupts from all three of its sub-modules 56 , 58 , 60 . The transcriptionist can use the foot pedal 66 to indicate that the audio should be “rewound,” or “fast-forwarded” to a different time point in the dictation. These foot-pedal presses are serviced as hardware interrupts by the user interaction module 42 . Most standard key presses and on-document mouse-clicks are sent to the word processing module 44 to perform the document editing functions indicated and to update the monitor display. Some user interaction, however, may be directed to the audio-playback oriented modules 46 , 48 , 50 , e.g., cursor control, audio position control, and/or volume control. The transcriptionist may indicate that editing is complete by clicking another icon. In response to such an indication, the final text file is sent through the database interaction module 42 to the database server 24 .
In operation, referring to FIG. 6 , with further reference to FIGS. 1-2 , a process 100 for extracting information from a transcription of speech using the system 10 includes the stages shown. The process 100 , however, is exemplary only and not limiting. The process 100 may be altered, e.g., by having stages added, removed, or rearranged.
At stage 102 , the automatic transcription device 30 seeks to transcribe the audio file, and to extract the header and footer from a dictation audio file stored in the database 40 . The automatic transcription device 30 accesses and retrieves the audio file from the database through the LAN 26 . The dictation is accompanied by the speaker name (and variants), the patient name (and variants), date information, MRN, as well as other available information.
At stage 104 , a speech recognizer of the device 30 analyzes the audio file in accordance with ASR models to produce a draft text document from the audio file. The ASR model includes information on the manner in which physicians dictate to decode word sequence.
At stage 106 , the device 30 identifies the header of the dictation using model grammars associated with header language. The identified header is removed from the dictation for separate storage in the database 40 . Confidential terms in the header are separately tagged.
At stage 108 , the device 30 identifies the footer of the dictation using model grammars associated with footer language. The identified footer is removed from the dictation for separate storage in the database 40 . Confidential terms in the header are separately tagged.
At stage 110 , the device 30 also produces a corresponding token-alignment file that includes the draft documents and associated portions of the audio file with the transcribed text of the documents. The token-alignment files include XML tags, such as <HEADER> </HEADER> and <FOOTER> </FOOTER> as meta information for the editing software, described below. The device 30 stores the token-alignment file in the database 40 via the LAN 26 .
At stage 112 , the header and the footer are stored in the database separate from other portions of the dictation. The header and footer are stored in a secure portion of memory in the server 24 . The remainder of the dictation is stored separately from the confidential information, e.g., in a separate file.
In operation, referring to FIG. 7 , with further reference to FIG. 1-6 , a process 200 for producing and editing a transcription of speech using the system 10 includes the stages shown. The process 200 , however, is exemplary only and not limiting. The process 200 may be altered, e.g., by having stages added, removed, or rearranged.
At stage 202 , the speaker 12 dictates desired speech to be converted to text. The speaker can use, e.g., a hand-held device such as a personal digital assistant, to dictate audio that is transmitted over the network 14 to the voice mailbox 16 . The audio is stored in the voice mailbox 16 as at least one audio file. The audio file is transmitted over the network 22 to the database server 24 and is stored in the database 40 .
At stage 204 , the automatic transcription device 30 seeks to transcribe the audio file according to the process 100 in FIG. 6 . The automatic transcription device 30 accesses and retrieves the audio file from the database through the LAN 26 . The dictation is accompanied by the speaker name (and variants), the patient name (and variants), date information, MRN, as well as other available information.
At stage 206 , the transcriptionist reviews and edits the transcribed draft document as appropriate. The transcriptionist uses the editing device 20 to access the database 40 and retrieve the audio file and the token-alignment file that includes the draft text document. The editing of header and footer data is further described below with respect to FIG. 8 . The transcriptionist plays the audio file and reviews the corresponding text as highlighted or otherwise indicated by an audio cursor and makes desired edits using, e.g., a text cursor 72 . The word processor 44 produces and stores track-changes information in response to edits made by the transcriptionist.
At stage 208 , the track-changes information is provided to the automatic transcription device 30 for use in improving the speech models used by the speech recognizer of the device 30 by analyzing the transcribed draft text and what revisions were made by the transcriptionist. The models can be adjusted so that the next time the speech recognizer analyzes speech that was edited by the transcriptionist, the recognizer will transcribe the same or similar audio to the edited text instead of the draft text previously provided. At stage 210 , the word processor provides a final, revised text document as edited by the transcriptionist. This final document can be stored in the database 40 and provided via the network 22 to interested parties, e.g., the speaker that dictated the audio file.
Referring to FIG. 8 , with further reference to FIGS. 1-7 , a process 300 for editing the header/footer data of the draft transcribed document, continued from stage 206 of FIG. 7 , using the editing device 20 includes the stages shown. The process 300 , however, is exemplary only and not limiting. The process 300 may be altered, e.g., by having stages added, removed, or rearranged.
At stage 302 , the transcriptionist logs in with a user name and password, and dictations assigned to them are shown in the queue. When a dictation is chosen, the audio and document are downloaded, preferably separately, to the transcriptionist's computer. The audio is preferably stored in a secure location. The audio may be separated into more than one file, such as a file for the header, a file for the footer, and a file for the body. Information from the token alignment file is used to find the correct location in the audio file in order to accomplish the audio separation.
In exemplary embodiments, audio separation is employed to additionally alter the audio file to remove patient identification information. For example, the audio might sound a tone in lieu of a spoken patient name is spoken. The audio exchanged for the confidential information may alternatively be an alias for the confidential term, such as a generic name, or other desired sound masking/concealing the actual spoken audio.
When the document is being edited, particular audio files can be accessed. The file-read permissions on the audio files and the document can restrict access to anyone but the transcriptionist who has logged on.
At stage 306 , the transcriptionist chooses an audio file associated with either the header, the footer, or the body. If the header or the footer are desired to be edited, the transcriptionist activates a hot key, at stage 312 , to call forth the grey boxes 78 , 79 so that the boxes appear on the monitor 52 . At stage 314 , the blocked access boxes 78 , 79 are displayed, and at stage 316 , the transcriptionist listens to audio associated with the header. A similar procedure would be used for editing other portions of a document containing confidential information. The transcriptionist may be required to enter a password or provide other security information before the grey boxes 78 , 79 appear on the monitor.
At stage 318 , the header fields are reviewed and/or edited. Data appearing in the grey boxes includes patient name and other confidential data that is reviewed for accuracy. Upon completion of editing, at stage 320 , the grey boxes 78 , 79 are hidden from view once again. Data entered into the boxes is no longer visible on the monitor 52 .
Other embodiments are within the scope and spirit of the appended claims. For example, due to the nature of software, functions described above can be implemented using software, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. In exemplary embodiments of the invention, the header and footer data are identified and separately stored in a database. It is possible that only one of the header and the footer may be identified and separately stored, or both the header and the footer data can be stored, e.g., in a common file separate from the remainder of the document. Storage of the header and the footer may not be separate from the remainder of the document, but transmittal of the header and the footer may be separated from transmittal of the remainder of the document. In an alternative embodiment, the editing program can include a timeout portion which observes whether there has been a break in editing or audio playback for a given amount of time. | A computer program product for use with dictated medical patient information resides on a computer-readable medium and comprises computer-readable instructions for causing a computer to analyze the dictated information, identify likely confidential information in the dictated medical patient information, and treat the likely confidential information disparately from likely non-confidential information in the dictated medical patient information. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of machine tools and more particularly to modifications with which a movable machining device can be displaced at high speed under the best environmental conditions.
2. Discussion of the Background
High-speed machining of parts in a machine tool generally takes place using a rotationally driven bit at the end of an electric spindle installed in a slide, which itself is mounted to be movable along two axes X, Y of a plane parallel to the plane of machining of the parts.
To facilitate reading of the description to follow, the plane XY of mobility of the movable device constituting the slide of the electric spindle will be assumed to be vertical, as is the case in the majority of embodiments of this type of machine tool in the field of high-speed machining.
A machine tool is classically provided with three main working stations, to wit:
a machining station proper, provided with the bit driven rotationally at the end of the electric spindle and shaping the part to be machined,
a drive station situated upstream from the machining station and made up of an assembly of devices that ensure in particular the X, Y and Z displacements of the slide of the electric spindle and the rotation of said spindle,
and a control station cooperating with the drive station and functioning with a program of instructions preestablished to take charge of the different stages of machining of the said part.
The Applicant has observed that, in machine tools for high-speed machining, the separation of the machining station from the drive station is never physically well defined, especially as regards the virtual vertical plane marking the boundary between the two stations. In fact, to permit free motion of the movable slide along the two axes X and Y in a displacement plane parallel to this vertical boundary plane, the most classical embodiment comprises making the external machining zone communicate with the internal drive zone of the machine. This results in major problems of protection with respect to how closely personnel can approach the inside of the drive station and also to the devices of the drive station, which are sensitive to thrown-off machining chips and to pollution in the external environment of the machine, which is generally placed in the midst of a more or less contaminated atmosphere.
This separation becomes necessary when the motors driving the devices of the machine in translational movement are linear motors. In fact, these motors are equipped with a permanent-magnet block, which thus attracts all wastes of metallic nature. In addition, the leaktightness of such a structure, which is most often planar, is never perfect regardless of the means for assuring leaktightness.
The publication DE A 4405247 describes a physical element having the form of a protective cowling for a device movable along two axes in a plane, comprising elements disposed parallel to the plane of displacement of the said movable device and guided by at least two pantographs, the end points of which are joined in articulated manner to the fixed first element and to a movable element, and the intermediate points of which are joined to movable intermediate elements, such that a displacement of the movable last element brings about a proportional displacement of the intermediate elements. In the present case of machine tools for high-speed machining, this protective cowling is therefore supposed to permit the installation of a distinct boundary between the machining station and the drive station and, in addition to sealing functions, it must also ensure great freedom of motion of the movable device (slide carrying the electric spindle) in a plane parallel to the machining plane. This preliminary disposition of the protective cowling has as an advantage the ability to act dynamically as a "hermetic" seal for the housing enclosing the devices of the drive station while ensuring that the movable device extending from the said housing has the kinematic ability necessary for positioning the bit during the different machining phases. In addition, the guarantee of leaktightness of the housing to external pollution for protection of the sensitive devices assembled in the drive station can be further improved by pressurizing the internal volume thereof relative to the outside situated behind the protective cowling.
SUMMARY OF THE INVENTION
To achieve these objectives, the telescoping cowling of the invention for protection of a device movable along the two axes X and Y meets all of these conditions and is adaptable more particularly to machine tools using high-speed machining operations with bits carried at the end of its electric spindle. For this purpose, the protective cowling of the invention is remarkable in that the said elements comprise panels, of which:
the first, fixed relative to the frame, is provided with a window through which the said movable device passes and the inner edges of which define the limits of freedom of motion of the latter,
the second, mounted slidingly relative to the first panel along the two displacement axes X, Y, has dimensions overlapping those of the window of the first panel and is provided with a window permitting motion of the said movable device,
and the third, movable and with dimensions substantially larger than those of the window of the first panel, accommodates at its center the said movable device, in such a way that the displacements of the movable device in the window of the first panel in the plane of the two axes X and Y brings about proportional mobility of the intermediate second panel, which is suitable for filling the opening of the window of the first panel left uncovered by the third panel as it accompanies the displacements of the said movable device.
The basic merit of this characteristic is to propose a cowling of three independent parts that cooperate with each other in such a way that:
the exterior panel can cover the part of the front face of the housing which is open around its window defining the limits of advance of the said movable device,
the intermediate panel can fill in as cover for the opening of the window of the exterior panel left free around the interior panel when the said movable device is displaced inside the said window, especially when it is close to the edges thereof,
and the interior panel can ensure that the opening of the window of the intermediate panel is covered around the said movable device.
In addition, when the movable device is displaced along the two axes X and Y in the window of the exterior panel, the interior panel cooperating therewith causes an identical displacement of the articulated end points of the pantographs to which it is joined and deforms the structure of the same pantographs, which transmit a displacement to the intermediate points thereof and to the intermediate panel joined thereto, since the position of the other two end points joined to the exterior panel is fixed.
The operation of a pair of pantographs as instruments for guiding the displacements of the intermediate panel offers numerous non-negligible advantages.
On the one hand, depending on the disposition of the intermediate points relative to the end points, they impose, for a unit of displacement of the movable device and of the interior panel attached thereto along the axes X or Y, a proportional unit of X or Y displacement of the intermediate panel such that the window of the exterior panel is always covered when the movable device borders the sides thereof, and this for a minimum overlap of the intermediate panel around the window of the fixed panel regardless of the travel of the movable device.
On the other hand, in the case of a vertical cowling, when the upper end points are joined to the high portion of the exterior panel, they ensure suspension and support of the intermediate panel between the interior panel and the exterior panel.
According to a particularly advantageous characteristic of the invention, two flat springs are disposed one on each side of the axis of the movable device, their central part being integral with the x and y movements of the movable device and their two ends being fixed to the said third panel such that they ensure that the extreme edges of that panel will press flat against the internal surface of the said intermediate panel. Thus a constant pressure is exerted on the joints, making it possible to ensure optimum leaktightness of the cowling and to compensate for the flatness defects as well as the spaces created between the panels when they are located slightly overhangingly in the extreme travel positions.
BRIEF DESCRIPTION OF THE DRAWINGS
Although the main aspects of the invention considered to be novel have been expressed hereinabove, more ample details concerning a preferred embodiment of a protective cowling in conformity with the fundamental concepts of the invention will be better understood by referring to the description hereinafter and to the accompanying drawings illustrating the said embodiment.
On these drawings:
FIG. 1 is a front view of such a telescoping protective cowling with a central position of the movable device.
FIG. 1a is a top view of the drawing of FIG. 1.
FIG. 2 is a front view of this protective cowling with an extreme position of the movable device.
FIG. 2a is a top view of the drawing of FIG. 2.
FIG. 3 is a side view of such a telescoping cowling with a central position of the movable device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated on the drawings as a whole, the telescoping cowling of the invention denoted by I as a whole is designed to ensure protection of a movable device, such as the slide (symbolized by the central shaded part O) of an electric spindle of a machine tool not shown, which moves in a vertical plane P according to displacements along the two axes X and Y, illustrated by the two double-headed arrows x and y. This slide O is also capable of motion relative to the cowling I, in a third translational movement illustrated by the arrows z of FIGS. 1a and 2a. This translational movement z specific to the slide as well as the rotational movement of the electric spindle will not be developed in the present description, because they do not add anything further to good understanding of the object of the present invention. This telescoping protective cowling is therefore designed to be installed perpendicular to the axis of the movable device O in a vertical plane parallel to the plane P of the two axes X and Y of mobility thereof, in order to define the limits of a physical boundary between the outside of the machine where a part is being machined by the bit attached at the end of the electric spindle, and the inside of the same machine, where there are installed the devices, which are sensitive to the surrounding pollution, for driving the said movable device.
According to the invention, the cowling I comprises three superposed vertical panels 100, 200 and 300 disposed parallel to the vertical plane P of displacement of the movable device O.
The first panel 100, situated on the outside of the machine, is mounted fixedly relative to the housing of the frame and is provided with a rectangular window 110, through which the movable device O extends and the inner edges of which define the limits of freedom of motion (arrows x and y) thereof.
The second panel 200, which is rectangular and situated toward the inside of the machine, and which is referred to as the intermediate panel, is mounted slidingly relative to the first panel 100 along the two axes X and Y according to two movements illustrated by the two double-headed arrows x' and y'. With dimensions smaller than those of the first panel 100, it outwardly overlaps the window 110 thereof for the purposes of covering it regardless of the position of the movable device O. It is also provided at its center with a rectangular window 210 disposed around the movable device and inwardly overhanging the edges of the window 110 of the panel 100 for a distance equal to that of the overlap of the intermediate panel 200 around the same window.
The third panel 300, which is rectangular and situated behind the intermediate panel 200 toward the inside of the machine, accommodates at its center a sleeve 310 in which there is installed the slide O of the electric spindle, which is also mounted to be movable perpendicular to the panel 300 in the inside of the sleeve 310, as shown by the arrow z. This panel 300, of dimensions substantially larger than those of the window 110 of the fixed panel 100, is urged in the same displacements of arrows x and y as those of its central sleeve 310 carried by the slide O of the electric spindle, which in the context of the present invention is understood to be the movable device.
A guide means 400 comprising two pantographs 400a and 400b situated in the same upper half-plane and on the same side of the fixed panel 100 makes it possible to ensure that the intermediate panel 200 is kept suspended and that it is guided in its displacements (arrows x' and y') between the panel 100 and the panel 300. For this purpose, the upper end points 410a and 410b of the pantographs 400a and 400b are joined in articulated manner to the fixed panel 100, the intermediate points 420a and 420b to the intermediate panel 200 and the lower end points 430a and 430b to the movable panel 300, such that a displacement (arrows x and y) of the panel 300 deforms the structures of the pantographs 400a and 400b, which necessarily transmit a proportional displacement (arrows x' and y') to their intermediate points 420a and 420b, since the position of the upper end points 410a and 410b is fixed relative to the fixed panel 100. By virtue of their displacements, these intermediate points 420a and 420b impart mobility to the intermediate panel 200 to which they are joined. According to a preferred embodiment of the invention, the intermediate points 420a and 420b are situated at the center of the end points of the pantographs 400a and 400b, so that a unit of displacement (arrows x and y) of the movable interior panel 300 suggests a half-unit of displacement (arrows x' and y') of the intermediate panel 200. This then results in simplifications of the panels, since it is sufficient that the overlap distances of the panel 200 to be respected inwardly and/or outwardly around the window 110 of the fixed panel 100 are equal to at least half the distances of displacement (arrows x and y) of the movable device O authorized inside the said window 110. This arrangement has the advantage of making the second panel 200 capable of completely filling the opening of the window 110 left uncovered by the panel 300 as it accompanies the x and y displacements of the slide of the electric spindle.
The drawings of FIGS. 1 and 1a illustrate the telescoping protective cowling I with the three panels 100, 200 and 300 in "intermediate" position, or in other words when the sleeve 310 of the panel 300 is at the center of the window 110. It is then observed that the opening of the latter is entirely covered by the panel 300 by itself and partly by the panel 200.
In the drawings of FIGS. 2 and 2a, the sleeve 310 of the panel 300 which has been displaced (arrows x and y) into the left lower corner of the window 110 of the panel 100 no longer ensures coverage of the opening of the same window at the position of its upper part and of its right part. This coverage is provided by the panel 200, which has followed a displacement proportionally reduced by half (arrows x' and y') and thus continues to cover the opening of the window 110, since these outside contours are kept back from the window 110 and since its inner window 310 is entirely covered by the panel 300.
According to a preferred embodiment of the invention, two flat springs 510 and 520 are disposed one on each side of the axis of the movable device O, their central part being integral with the x and y movements of the movable device O and their two ends 510a, 510b and 520a, 520b being fixed to the said third panel 300 such that they ensure that the extreme edges of that panel 300 will press flat against the internal surface of the said intermediate panel 200. The function of these springs 510 and 520 is to hold the joints on the surfaces with which they must achieve leaktightness, regardless of the position of the movable device O, while compensating for the flatness defects that can occur in the extreme positions of the movable device O.
As illustrated in the drawing of FIG. 3, a chute 600 fixed to the frame close to the said cowling I ensures collection, over the entire width of the window 110 provided in the first panel 100, of dust or chips that have infiltrated through the said cowling I. In fact, since the joints are most often placed on the fixed part and since the window 110 provided in the first panel 100 is larger than the window 210 provided in the intermediate panel 200, and taking into account the fact that the cowling I is vertical, it is particularly judicious to place this chute 600 under the entire width of the window 110 to recover the maximum of dust and chips.
Advantageously, the said chute 600 is made of a flat profile preformed at its upper end 610 in such a way as to form a first constriction with the wall of the cowling I, which constriction facilitates falling of chips or dust into the inside of the chute and prevents the dust or chips from climbing back up the said chute and, at the level of its lower end 620, a second constriction facilitating evacuation of the dust or chips to the outside of the housing toward the collection trough 700, which is classically situated between the vertical wall of the machine tool and the machining station.
The chute 600 forms with the wall of the said cowling I a pressure-drop airlock 630 discharging to the collection trough 700 situated in the machining station, while preventing infiltration of clouds of metallic dust and ensuring evacuation of the wastes infiltrating through the joints of the said cowling under the action of an air movement created in the inside of the housing formed by the machine tool. In fact, when equipped with this cowling, the machine tool forms a quasi-hermetic housing which permits the air pressure in the interior thereof to be increased either by the devices already present in the housing (supply by pneumatic devices, fan integrated into the components) or by an auxiliary ventilation source provided for this purpose. The displacement of air under pressure created in the housing of the machine tool will ensure, by virtue of the constrictions 610 and 620, a suction phenomenon making it possible to evacuate all of the dust and chips that have been able to infiltrate into the inside of the housing of the machine tool. Another advantage of this chute 600 is that the pressure drop beginning at the level of the airlock 630 permits a continuous jet of air toward the outside, which prevents the clouds of metallic dusts created by machining, especially by machining of cast iron, from infiltrating via the first constriction situated at the end 620 of the chute 600. As such auxiliary collection means, this chute, in association with the cowling I, permits a better guarantee of the service life of the components of the machine tool.
It is understood that the description and illustration just given hereinabove of the telescoping protective cowling are given for the purpose of disclosure and not limitation. It is obvious that various arrangements of, as well as modifications and improvements to, the example hereinabove will be possible without departing from the scope of the invention taken in its broadest aspects and spirit.
For example, it is possible to interpose a plurality of intermediate panels 200 between the exterior panel 100 and the interior panel 300 guided in their displacements by pantographs at a plurality of intermediate points (the number being equal to that of the intermediate panels), each joined to an intermediate panel. | A telescoping protective cowling for removing part of a machine tool. The device includes at least three elements consisting of panels and one of which is stationary or relative to the frame and provided with a window with inside edges restricting the freedom of movement of a moving part. The second panel is slidable relative to the first panel along two axes, is longer than the window of the first panel and is provided with a window within which the moving part is free to move. The third panel is movable and substantially larger than the window in the first panel and receives the moving part in its central portion. As a result, the movements of the moving part in the plane of the two axes in the window in the first panel means that the second panel has a proportional mobility and is thus able to fill the opening of the window in the first panel after it has been left clear by the third panel following the movements of the moving part. | 1 |
FIELD OF THE INVENTION
The present invention in general relates to an air handling detector housing, and in particular to a housing having components facilitating prolonged detector fail safe operation and efficient detector testing.
BACKGROUND OF THE INVENTION
Air handling duct systems are routinely fitted with air quality detectors such as smoke detectors or carbon monoxide detectors so as to detect an air quality problem and the resulting hazard before the gas is further distributed by the air handling system. Such detectors are routinely placed within a housing receiving inlet sample gas from an air handling system conduit and an outlet exhaust from which air handling system gas is returned to the same or different conduit of the air handling system so as to create a swirling flow pressure differential of air handling system gas around the detector within the housing. Such detectors are periodically tested to assure that a detector properly samples and signals an alarm in response to exposure to a target level of gas or activation of a test circuit.
A conventional air handling duct detector housing has a number of limitations that complicate testing and assured operation of a detector contained therein. A representative prior art air handling duct detector housing is provided in FIG. 1 . A conventional housing has a body including midline inlet I and outlet O apertures along line M-M′ for air to pass therethrough and a cover C that is often transparent that secures to the housing body by way of threaded fasteners F. The housing volume is proportioned and divided to accommodate a given detector D and related printed circuit boards P and electronics needed for coupling to a relay board, providing various normal, alarm, and trouble output signals and the like. The configuration of the air inlet and outlet apertures in communication with an air duct are routinely positioned midline within the housing as shown in FIG. 1 . When moisture-laden air is conveyed through the air handling system, or alternatively the housing is at a lower temperature than the inlet air, condensation tends to collect within the housing. Under prolonged condensation conditions, water can accumulate in the housing to the midline of the housing resulting in active detector elements for electronic components being submerged in water resulting in emergency service to avoid component failure. Additionally, the seal line at the interface between the housing body and cover, while providing a generally waterproof seal, provides an inadequate barrier against vapor and the thermocycling associated with outdoor placement and as such a detector housing of FIG. 1 is limited to indoor placement. Still another limitation found in a conventional prior art housing is reliance on multiple threaded fasteners to provide a gradual tightening of the cover to the housing body. As a result a loose cover placement will not signal a warning and inhibit proper operation of a detector system. The simultaneous operation of a screwdriver to drive threaded fasteners while holding already removed fasteners, stabilizing the cover all while often balancing on a ladder also leads to inefficient servicing, unpredictable alarm operation and a falling hazard.
In view of the limitations found in a conventional prior art housing, there exists a need for an air handling system duct detector housing that is less vulnerable to detector failure through water egress and provides assured repeatability of sealing. There also exists a need for a detector housing that expedites detector testing and servicing and assures proper alarm operation.
SUMMARY OF THE INVENTION
A duct detector housing includes a housing cover and a housing body defining a midline between the center of a detector and a printed circuit board within the body. The housing body has a gas inlet and a gas outlet in fluid communication therewith. The gas inlet in fluid communication with a gas duct. The gas inlet and the gas outlet are off axis of the midline to allow water that collects in conventional housing to drain from the housing regardless of mounting orientation when the water reaches the level of either the inlet or outlet.
A process for testing a detector mounted within a duct housing sampling a forced air duct includes providing a maintenance mode button associated with a duct detector housing cover that is secured to a housing body of the housing and containing the detector therein. The maintenance mode button is activated to provide a preselected time period during which removal of tie cover is independent of a cover removal alarm. The cover is then removed, the internal detector tested and the cover replaced without a spurious alarm signal being recorded.
A duct detector housing includes housing cover and a housing body having a gas inlet and a gas outlet with the gas inlet in fluid communication with a gas duct and complementary to the cover to form an interface therebetween. The housing encompasses a detector and a printed circuit board within the housing body. The printed circuit board has dedicated terminal blocks providing grouped connections of at least fire alarm connections, detector interconnect connections remote access connections, HVAC connections and inlet power connections with each of the groups segregated from another.
An improved duct detector terminal including a wire entering a terminal and a clamping lever that engages the wire through a clamping mechanism has the improvement of a hole in the terminal adapted to receive a test meter probe therethrough to provide an electrical contact between the wire and a test meter without resort to disengaging the wire through operation of the lever.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a prior art detector housing;
FIG. 2 is a plan view of an inventive detector housing;
FIG. 3 is a partial cutaway view of the housing of FIG. 2 depicting a single latch binary securement depicted in an open position;
FIG. 4 is a perspective magnified view of a slide binary securement apparatus herein;
FIG. 5 is a cross-sectional magnified view of a bayonet binary securement operative herein;
FIG. 6 is a plan view of the inventive housing of FIG. 2 with a housing cover hanging tethered to a housing body;
FIG. 7A is an exploded, partial cutaway, perspective view of the housing of FIG. 2 depicting an inventive cover seating system;
FIG. 7B is a magnified cross section of an inventive gasket closure in relation to a simultaneously contacting cover lip and housing extending wall surface of FIG. 7A ;
FIGS. 8A-8D are a schematic of water level management obtained through an inventive housing body of FIG. 6 regardless of mounting orientation;
FIG. 9 is an inventive layout for a duct detector printed circuit board;
FIG. 10A is a perspective view of a conventional prior art node to a wiring terminal; and
FIG. 10B is a perspective view of an inventive node to a wiring terminal including a test meter probe hole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An inventive duct detector housing provides numerous improvements over the prior art housings as embodied in FIG. 1 with these improvements alone or in combination rendering more efficient the testing and maintenance of a detector enclosed within such a housing. The aspects of the present invention will be further detailed with respect to the following figures.
Referring now to FIGS. 2-9 , an inventive housing is shown generally at 10 . The housing 10 has a housing body 12 having an inlet 14 and an outlet 16 . The inlet 14 is in fluid communication with an air flow through which air or any other flowing gas enters the housing 10 and into contact with a detector D energized and residing within a detector volume 18 . The detector volume 18 is defined by the cavity formed within the housing body 12 upon mating with a complementary housing cover 20 . The housing body 12 is formed from a variety of materials illustratively including steel, aluminum, thermoset resins, and thermoplastics. Preferably, the housing body 14 is formed of injection moldable thermoplastic such as Bayer Machrolon. The housing body 12 preferably includes a flange 22 adapted to pass a mechanical fastener therethrough so as to secure housing body 12 to a substrate. Typical substrates for mounting an inventive housing 10 are surfaces such as walls and air ducts. While it is conventional to position an inlet and outlet along a midline of the housing body per FIG. 1 , preferably an inlet 14 and outlet 16 in a housing body 12 according to the present invention are positioned such that at least one of the inlet 14 or outlet 16 is positioned proximal to a bottom edge based on mounting orientation of an inventive housing 10 to a vertical substrate. As a result of at least one of the inlet 14 or outlet 16 being positioned proximal to the bottom edge of the housing 10 as mounted, condensation introduced into the housing detector volume 18 drains back through the bottom edge proximal inlet 14 or outlet 16 so as to preclude condensation water levels rising within the housing detector volume 18 to a level that impairs function or induces malfunction of the detector D housed within the volume 18 . To facilitate joinder of inlet 14 and outlet 16 to tubing in fluid communication with an air duct, the portion of the inlet 14 and outlet 16 within the housing detector chamber 28 are preferably notched and have a securement as detailed in U.S. Pat. No. 7,204,822. More preferably, the inlet 14 and the outlet 16 are positioned diametrically relative to a central detector D so as to maintain conventional convection with the diametrically opposed inlet 14 and outlet 16 each being positioned at an angle of approximately 45 degrees removed from the midline 24 of the detector body 12 . The two possible diametric lines positioning for inlet 14 and outlet 16 are denoted in FIG. 2 as 26 and 26 ′. Although the figures depict the inlet 14 and outlet 16 as being along line 26 , it is appreciated that they are equally well positioned along line 26 ′ to provide an equivalent diametric position with at least one of the inlet 14 or outlet 16 able to act as a drain of condensate regardless of whether an inventive housing 10 is mounted horizontally per FIGS. 8A and 8B , an inverted horizontal mounting per FIG. 8 or a vertical mounting of an inventive housing 10 per FIGS. 8C and 8D . The ability of inventive housing 10 having diametrically positioned inlet 14 and outlet 16 that are offset from midline 24 by an angle of between 30 and 60 degrees and preferably about 45 degrees to function as a condensate drain is depicted schematically in FIG. 2 . While the housing body 12 is depicted with a rectilinear housing detector chamber 28 , it is appreciated that a variety of other shapes are also amenable to the condensation drain aspects associated with placement of an inlet 14 or outlet 16 along a bottom edge relative to mounting position. These other shapes illustratively include circular, square, triangular and other regular and nonregular polygonal shapes.
The housing body 12 is optionally divided into a housing detector chamber 28 and a printed circuit board (PCB) chamber 30 that are physically isolated yet provide electrical communication therebetween. A printed circuit board (PCB) 32 is secured to the housing body 12 by way of anchor posts 34 extending into the PCB chamber 30 . The advantage of physical isolation between housing detector chamber 28 and PCB chamber 30 is to isolate the electronics on PCB 32 from particulate and condensation associated with gas flow introduced by way of inlet 14 . It is appreciated that a single chamber housing is readily provided and protection of PCB 32 provided by way of PCB 32 encapsulation. Preferably, the housing body 12 has one or more preformed apertures 36 or a thin-walled region 38 that upon dislodgement defines an aperture. An aperture 36 or a thin-walled region 38 is intended to provide a site for joinder of an electrical wire coupling 40 .
Intermediate between the cover 20 and the housing body 12 is a gasket. As depicted with respect to prior art FIG. 1 , a circular, square or rectilinear cross section gasket G is press fit between a groove adapted to receive the gasket and a flat surface associated with the inner surface of a cover and housing body face. Unfortunately, such as gasket tends to be thin pinched by uneven pressure associated with fastener pressure urging the cover into contact with the gasket and the housing body thereby resulting in an unreliable seal. Additionally, single point of contact seals as well as fluid ingress by way of fastener holes precludes outdoor placement of such a prior art housing. In a preferred embodiment, an inventive gasket 42 having at least one lateral contact point 43 between a cover lip 52 encompassing an extending wall 44 of the housing body 12 . The gasket 42 secures to an extending wall bounding one or both of the housing detector chamber 28 and the PCB chamber 30 in FIG. 7A . The extending wall 44 projects upward relative to housing body surface 46 as depicted in FIGS. 7A and 7B . The gasket 44 is adhesively secured to the extending wall 44 such that at least one protrusion from the gasket 42 extends outward relative to the extending wall 44 to form contact points 43 and preferably multiple contact points 43 . More preferably, the gasket 42 has a top cap portion 48 . Most preferably, the top cap portion 48 overhangs the extending wall 44 so as to overlie one of the housing detector chamber 28 or PCB chamber 30 . The nature of the inventive gasket is best shown with regard to the magnified outset cross-sectional image provided in FIG. 7B . A cover 20 engaging an inventive gasket 42 has a cover lip 52 adapted to encompass the extending wall 44 with a degree of clearance such that the protrusions 46 are laterally compressed therebetween. The cover lip 52 intersects a covering surface 54 of the cover 20 and simultaneously compresses a top cap portion 48 of gasket 42 , if portion 48 is present. Preferably, the cover 20 has an inner lip 56 adapted to engage an overhang portion 50 of the gasket 42 , if present. In contrast to prior art gasket sealing schemes per prior art FIG. 1 , an inventive sealing system involving a cover 20 , housing body 12 and a gasket 42 preferably provides multiple contact points 43 . With securement of a gasket 42 to an extending wall 44 with a conventional adhesive such as an acrylic adhesive, five separate gasket seal points are provided as depicted in FIG. 7B with three contacts associated with protrusions 46 , one with top cap protrusion 48 and one with overhang portion 50 . Such a gasket renders an inventive housing suitable for outdoor placement. An inventive gasket 42 requires a degree of compressibility difficult to achieve with a conventional solid neoprene gasket such as G of FIG. 1 . Preferably, an inventive gasket is an expanded elastomer such as neoprene, latex, natural rubber, or other appropriate compounds either in singular or mixed compounds present as either an open-celled or closed-celled foam sponge. Preferably, the gasket 42 is a closed-cell foam so as to preclude water intercalation by way of gasket porosity.
An additional problem associated with conventional housings such as those of prior art FIG. 1 , through resort to multiple mechanical fasteners to secure a cover to a housing body since integrity of the seal between cover and housing body is suspect owing to variables such as differential torque applied to fasteners, stripped fastener threads, and a missing fastener. Additionally, a technician standing on a ladder using one hand to position a cover by using the other hand to attempt to secure fasteners represents not only an installation and maintenance inefficiency but also a safety hazard. In order to overcome the limitations associated with multiple threaded fasteners used to secure a cover in place, an inventive housing 10 preferably resorts to a binary securement mechanism 60 . The binary securement mechanism is distinguished over the prior art in having definitive “open” and “closed” positions that preclude the graded tightening of a threaded fattener. The binary mode securement mechanism 60 is depicted as a pivoting latch 61 in FIGS. 2 , 3 , 6 and 7 ; a sliding latch 61 ′ as depicted in FIG. 4 ; and a bayonet latch 61 ″ in FIG. 5 . The binary mode securement mechanism 60 provides ease of cover securement while assuring seal integrity regardless of whether an inventive gasket 42 or a conventional gasket G is present at the interface between the cover 20 and the housing body 12 . The latch 61 - 61 ″ is typically formed of materials such as those from which the housing body 12 is formed and includes a hook engagement portion 62 , 62 ′ or a pin 63 and a handle portion 64 - 64 ″. The latch 61 is pivotally secured to the cover 20 about a pivot pin portion 66 of the cover 20 of FIG. 3 . The latch 61 ′ is mounted to track 59 to slide laterally in the cover 20 ′ of FIG. 4 . Preferably, the hook engagement portion 62 or 62 ′ has a first notch 68 or 68 ′ in a complementary position relative to a catch 70 or 70 ′. The latch 61 ″ of FIG. 5 press fits against cover 20 ″ in response to a pin 63 engaging a groove 65 in a socket 67 adapted to receive cylindrical base 69 of the latch 61 ″ with rotation of the handle portion 64 ″. The groove 65 has a discontinuous closed portion 71 that assures a binary closed position. Preferably, a spring-loaded plate 73 ejects the base 69 to an “open” position when in a position other than the pin 63 engaging groove closed portion 71 .
The common feature of binary mode securement mechanism 60 reproducible assurance that the latch 61 - 61 ″ is either “open” or “closed.” Preferably, the binary mode securement mechanism 60 is located intermediate between a housing detector chamber 28 and a PCB chamber 30 so as to assure a generally uniform circumferential pressure applied to a gasket 42 or G upon sealing of a cover 20 - 20 ″ to a housing body 12 - 12 ″. More preferably, a second notch 76 or 76 ′ is provided that is complementary to a cover stay 78 , 78 ′ or 78 ′ integral with the cover 20 or 20 ′ such that the second notch 76 or 76 ′ upon engagement of the cover stay 78 or 78 ″ holds the binary mode securement mechanism 60 in an “open” position. It is appreciated that first notch 68 is readily placed on surface 72 while catch 70 is readily placed onto hook engagement portion 62 forming an inverted complementary pair of notch and catch. Likewise second notch 76 or 76 ′ and cover stay 78 or 78 ′ are readily inverted as to placement on hook engagement portion 62 or 62 ′ and cover 20 or 20 ′ to form an equivalent latch retention position. Still more preferably, an indent 80 is provided in the cover 20 adjacent to the handle portion 64 of the latch 61 when in a closed position. An indent 80 is provided to facilitate operation of the latch 61 . Preferably, cover removal button 82 is provided to communicate to the cover removal switch 84 on a printed circuit board 32 . The cover removal switch 84 - 84 ″ sends an electrical signal based on whether the cover removal button 82 - 82 ″ is depressed by the handle 64 - 64 ″ or free of contact with the latch 61 - 61 ″. Preferably, when a cover removal button 82 is present, the button is positioned in the cover 20 - 20 ″ so as to be depressed when the handle portion 64 - 64 ″ in a fully closed position. Alternatively, a cover removal button 82 is provided in an underlying relationship relative to mode binary securement mechanism surface 72 or 72 ′ or plate 73 such that the hook engagement portion 62 or 62 ′ or base 69 likewise depresses a cover removal button 82 when the mode binary securement mechanism 60 is in a closed position. It is appreciated that covers 20 ′ and 20 ″ as well as complementary housings 12 ′ and 12 ″ are identical to cover 20 and housing 12 , respectively, with the exception of differences in securement mechanism 60 and description of other inventive attributes are equally operative therewith.
Optionally, a removable baffle 37 designed to insert within the housing detector chamber 28 serves to overlie the detector D and overlie at least one of inlet 14 or outlet 16 is provided to modify air circulation within the housing detector chamber 28 based on the performance characteristics of the detector D and the velocity of gas entering housing 10 by way of the inlet 14 . An alarm test of detector D is optionally provided by inclusion of an elastomeric test port in the cover 20 as detailed in U.S. Pat. No. 6,741,181.
In a preferred embodiment, a cover 20 has exposed thereon a maintenance mode button 90 , a test/reset button 92 and indicator lights indicative of pilot mode 94 , trouble mode 96 and alarm mode 98 . Preferably, the lights 94 , 96 , 98 are light emitting diodes (LEDs). An inventive housing 10 with the provision of buttons 80 , 92 , 94 and indicator lights 94 , 96 , 98 allows an installer, a service technician or an inspector of an inventive housing 10 to readily access sequence of operations for either indoor or outdoor units. In contrast to conventional detector test protocols initiated by removal of a cover, an inventive detector housing 10 eliminates dual trouble signals when trouble and alarm testing are performed on detectors associated with monitoring smoke alarm systems. As a result of the ability to initiate maintenance or test/reset detector associated electronics without cover removal, alarm cover removal switch 84 is not triggered in the process thereby simplifying system testing readout and test protocols.
By way of example, operation of an inventive detector housing 10 in a maintenance mode is provided. The detector D and associated housing 10 in normal mode is indicated by operating power on, the cover 20 in place and pilot light 94 illuminated steady, preferably color coded as green; trouble indicator 96 , preferably a yellow LED off; and alarm indicator 98 off, preferably in a red LED, as well as the trouble and test/reset buttons in normal inactive states 92 and 94 . Depressing the maintenance button on the cover 20 , housing body 12 , or remote from the housing 10 activates a maintenance mode switch causing the pilot indicator light 94 to begin to flash which confirms maintenance mode initiation. A remote button is typically associated with a master control unit monitoring multiple detectors in multiple housings 10 . Once maintenance mode button 92 has been pushed, the detector D goes into approximately a three minute timed test/maintenance mode where the front cover 20 can be removed for internal testing trouble and alarm functions of the detector D itself. Specific problems associated with the detector D which are tested for include proper placement of a detector head and an alarm caused by smoke testing of the detector head. During this three minute timed test, the position of the cover 20 does not affect the status of the detector housing 10 . It is appreciated that this three minute timed test/maintenance mode is readily preselected to be a longer or shorter interval and is also well suited for troubleshooting minor wiring or electrical problems. While pilot light 94 is flashing, the trouble light 96 and alarm light 98 follow the actions as performed on the detector D itself. The alarm and trouble contacts on the printed circuit board P will also follow these actions as performed on the detector D for proper system integration testing. Upon proper replacement of the cover 20 , the maintenance mode is automatically canceled but housing 10 reverts to normal operational status where failure of the cover 20 to be properly placed and the latch 60 closed to depress button 82 immediately causes a trouble condition. During the maintenance mode timing sequence optionally additional testing and maintenance time can be provided in three minute increments with a momentary repeated depression of the maintenance mode switch on the printed circuit board P that was previously engaged by depressing maintenance button 90 . With depression of the maintenance mode switch, additional three minute increments of maintenance time are provided. In the event the maintenance mode switch is not activated to provide an additional three minute increment of operational time, the pilot indicator light 94 extinguishes and the trouble indicator 96 illuminates and the trouble contacts transfer immediately upon opening binary mode securement mechanism 60 and/or subsequent removal of the cover 20 . A representative test sequence procedure includes: (1) Push maintenance mode button 90 momentarily and confirm mode activation by flashing pilot light optionally alternating with trouble indicator LED 96 . (2) Unlatch latch 60 and remove cover 20 . Preferably, a tether 100 as shown in FIG. 6 maintains the cover 20 in proximity to the housing body 12 after removal. (3) The head of the detector D is twisted out to verify proper unit and system trouble response. (4) The head of the detector D is twisted back into place to verify proper unit and system trouble restoral. (5) A smoke test for the detector D is used to provide proper unit and alarm response. (6) With the clearing of any residual smoke from the detector head and with momentary depression of the test/reset button 92 , proper unit and system alarm restoral is confirmed. (7) The cover 20 is replaced and secured by pressing the latch handle portion 64 to a closed mode and in the process depressing a cover removal button 82 , if present.
Preferably, while an inventive housing 10 is in maintenance mode, the flash rate of the pilot indicator light 94 begins flashing at a rate that increases as the timed maintenance mode period approaches within thirty seconds of preselected time sequence completion, or any other preselected window of time test completion. In the event that the maintenance mode button 90 is activated by mistake, maintenance mode button 92 is optionally depressed within a preselected amount of time within the initial depression such as for example ten seconds to cancel the maintenance mode request. An additional optional mode is that if the maintenance mode button 90 is activated and the binary mode securement mechanism 60 is not released within a preselected amount of time such as for example twenty seconds, the timed test/maintenance mode is terminated and the housing 10 is returned to normal mode as indicated by pilot indicator light 94 being continually green. It is appreciated that the lights 94 , 96 , 98 are mounted on an underlying printed circuit board P and visible through the cover 20 such that removal of cover 20 does not limit operational status information from installer or a service provider or an inspector during removal of the cover 20 .
Referring now to FIG. 10 , an inventive layout for a printed circuit board for inclusion in an inventive housing 10 is provided generally at 212 . The printed circuit board 212 in contrast to a conventional PCB P segregates wire connection blocks based on individual specialists who may access an inventive housing 10 . Specifically, terminal blocks are associated with fire alarm connections 202 , HVAC connections 204 , detector interconnect connectors 206 , remote accessory connections 208 and input power connections 210 on PCB 212 . With the provision of dedicated terminal blocks based on specialty, an individual accessing a PCB 212 for a specific purpose concentrates their energy on a collected set of connections related to their purpose instead of the same number of connections scattered across the surface of PCB 212 . Preferably, indicia as to the nature of the terminal blocks 214 is provided on the board 212 . More preferably, the dedicated terminal blocks 202 - 210 of PCB 212 are color coordinated.
Referring now to FIG. 11A , a conventional prior art terminal as used on PCB P is shown inclusive of a wire W entering the terminal T. A clamping lever L allows for selective securement or release of the wire W and the terminal T. The testing of terminal T and wire W currently requires the latch L to be operated to disengage the wire W.
FIG. 11B shows an improved inventive terminal 300 that represents an improvement over the prior art terminal depicted in FIG. 11A on the basis of providing a test meter probe hole 302 providing electrical continuity testing of the wire W without resort to operating the clamping lever L. Like numerals and letters are used to designate like components detailed above with respect to prior art FIG. 11A . With the provision of hole 302 , the time of testing is reduced as well as the prospect of damaging by over stripping resulting in shock and short danger the contact between a wire W and a terminal T associated with unclamping and repeatedly clamping wire W with resort to lever L.
Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.
The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention. | A duct detector housing includes a housing cover and a housing body defining a midline between the center of a detector and a printed circuit board within said body. Gas inlet and outlets are off axis of the midline to allow water that collects in conventional housing to drain from the housing. A maintenance mode button associated with a duct detector housing cover that is secured to a housing body of the housing provides a preselected time period during which removal of the cover is independent of a cover removal alarm. A printed circuit board within the housing has dedicated terminal blocks providing grouped connections with each of the groups segregated from another. An improved duct detector terminal has a hole in the terminal adapted to receive a test meter probe therethrough to provide an electrical contact between the wire. | 5 |
REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent application Ser. No. 13/029,876, filed Feb. 17, 2011, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/306,155 filed Feb. 19, 2010 entitled MULTI-POSITIONED ANGLED STEP AND RISERS both of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to aerobic exercise devices and, more particularly, to an adjustable stepping structure for aerobic exercises.
BACKGROUND OF THE INVENTION
[0003] Aerobic exercise platform devices, such as The STEP® are often used in physical fitness regimens to assist in aerobic workouts and simulating climbing or stair activities. One example of these is shown in U.S. Pat. No. 5,158,512. These platforms are typically horizontal with elongate, rectangular shapes having a height simulating a stair step. When a higher step is desired for a more difficult routine, one or more risers can typically be placed under the platform to raise the total height of the platform. A typical platform includes a tread or traction area on the top and a stable base to minimize the risk of a person slipping.
[0004] An improved exercise system is desired.
SUMMARY OF THE INVENTION
[0005] In one configuration, the present system includes an adjustable top portion or platform with one or more support elements or risers. In certain preferred embodiments, the platform and risers may be placed or arranged to provide various levels of platform height and/or an angled platform surface. Preferably each support element is capable of being telescopingly received within the bottom of the platform section, as well as being received within the bottom of another support element so that they are vertically stackable. In certain embodiments, one or more of the support elements include notches in the top section allowing the platform section to be supported at an angled orientation relative to either the length or width of the platform section.
[0006] Preferably the exercise system can be used as a standard horizontal platform or as an angled platform for aerobic exercises, stretching, yoga, or balancing exercises.
[0007] It is an object of the invention to provide an improved exercise system.
[0008] Further objects, features and advantages of the present invention shall become apparent from the detailed drawings and descriptions provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 . is an exploded perspective view of an embodiment of the present invention.
[0010] FIG. 2 is a front view of a portion of the embodiment of FIG. 1 .
[0011] FIG. 3 is a bottom plan view of a portion of one of the support elements of the embodiment of FIG. 1 .
[0012] FIG. 4 is a cross-sectional view of the embodiment taken along line 4 - 4 of FIG. 2 .
[0013] FIG. 5 is a perspective view of a support element of the embodiment shown in FIG. 1 .
[0014] FIG. 6 is a top view of a support element of the embodiment shown in FIG. 1 .
[0015] FIG. 7 is a side view of a support element of the embodiment shown in FIG. 1 .
[0016] FIG. 8 is a perspective view of a platform supported along a lengthwise angle on a support element.
[0017] FIG. 9 is a side view of the embodiment of FIG. 8 .
[0018] FIG. 10 is a front view of a platform supported along a widthwise angle on two support elements.
[0019] FIG. 11 is a side view of the embodiment of FIG. 10 .
[0020] FIG. 12 is a perspective view of a support element according to a further embodiment for use with the platform of FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations, modifications, and further applications of the principles being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0022] FIGS. 1-11 depict an example embodiment, denoted generally by the numeral 100 , comprising a platform section 112 and a plurality of risers or support elements 114 which provide means for vertically adjusting the height of platform section 112 in a horizontal or angled arrangement above a support surface, such as a floor. The illustrated embodiment 100 is constructed of molded high impact plastic materials.
[0023] The platform section 112 is generally rectangular in shape with a length and a width and a substantially planar top with a stepping surface 116 having a non-slip, textured surface or coating 117 thereon. A pair of sidewalls 118 and a pair of endwalls 120 extend downward and optionally slightly outwardly from the top surface 116 to a transition point 121 . The walls 118 and 120 then extend further downwardly to lower rounded side edges 123 and end edges 125 . Optional openings or passages 129 are provided, for example by molded areas, to aid in maneuvering and aligning the platform section 112 .
[0024] As illustrated in FIGS. 1 and 2 , each support element 114 is capable of being telescopingly or nestably received within the bottom of the platform section 112 , as well as being received within the bottom of another support element 114 so that they are vertically stackable. In certain embodiments, one or more of the support elements further include notches 170 in the top section allowing the platform section to be supported in an angled orientation relative to either the length or width of the platform section. In other words, the platform 112 may oriented with the smaller-width end supported within the notches 170 , or oriented with the longer-length side supported within the notches 170 .
[0025] The illustrated support element 114 is a generally square or rectangular shaped unitary member, preferably with an open center. Each support element includes a top section 131 having a slightly rounded top 133 and downwardly extending outer sidewalls 135 . A lower section 143 includes a curved, base portion 145 that terminates in a lower edge 149 . Lower section 143 is generally arranged and configured to rest flat upon a support surface or to rest flat upon an underlying support element. The cross-section of top section 131 is substantially parallel to the cross-section of lower section 143 . Optional molded openings 153 are formed in the lower edges 149 of support elements 114 to aid in maneuvering and aligning the support elements 114 .
[0026] As seen in a cross-sectional view in FIG. 4 , the walls of platform 112 and sidewalls of lower section 143 each include interior wall portions which project downwardly. Preferably the outer cross-section of top section 131 is sized to be telescopingly and internally snugly received adjacent the interior wall portions within the bottom of the platform section 112 or within the bottom of another support element 114 so that one or more support elements 114 and platform 112 may be vertically stacked. In alternate embodiments, a platform may have portions which telescopingly engage a support element, for example by having portions of the platform received within a cavity defined in a support element.
[0027] In one embodiment, as shown in FIG. 5 , the support elements 114 may each include continuous or discontinuous horizontal ledge portions 137 . The ledge portions 137 extend outward from sidewall 135 of top section 131 and above lower section 143 . In the illustrated embodiment, each support element 114 includes a pair of short ledge portions on two opposing sides of the support element and a pair of longer ledge portions on the other two sides of the support element. In certain embodiments, the top portions of the ledge portions 137 are at a height equal to or slightly below the height of the lowest points of notches 170 .
[0028] In certain embodiments, ledge portions 137 may be sized and placed to correspond to the positions of molded openings 129 and 153 , and can extend horizontally outward to support all or a portion of the thickness of the respective platform or support element sections. In the illustrated embodiments, the pair of short ledge portions are intended to allow a support element 114 to engage in registry with corresponding short molded sections along the sidewalls 123 of platform 112 , while the longer ledge portions allow for a support element 114 to be placed at either end of platform 112 with a longer ledge portion of the support element engaging one of the end walls 125 of the platform. The differently sized ledge portions assist in aligning the platform with a support element. The ledge portions 137 may also be used to ensure a desired alignment when multiple support sections 114 are stacked.
[0029] Optionally, an element such as a circular foot portion 155 is located at each bottom corner of platform 112 and each support element 114 to engage a support surface or to engage in registry with an upwardly facing depression 157 located on an upper facing surface of an underlying support element. Foot portions 155 preferably assist in supporting, aligning and stabilizing the upper platform and/or support elements in horizontal arrangements.
[0030] In certain preferred embodiments, support elements 114 include at least one pair of notches 170 defined in parallel on opposite edges of top section 131 . In these embodiments, the rounded top 133 has downward arcuately curved notches 170 with a length equal to or shorter than the length of a sidewall of top section 131 . In certain embodiments, the profile of notches 170 substantially corresponds to the profile of the lower edges of sidewalls 123 and endwalls 125 of platform 112 . The profile of the notches may include such properties as length, width, depth, radius, cross section, or other dimensional properties.
[0031] Preferably, notches 170 are arranged in parallel pairs aligned both vertically and horizontally to define a channel 172 with a horizontal axis 174 crossing the top of the support element 114 . While illustrated with one pair of notches, in alternate embodiments two pairs of notches can be formed with one notch in each side of top section 131 . Alternately, multiple notches of greater or lesser length and depth can be defined along a side of top section 131 to define alternately selectable horizontal channels and angular arrangement.
[0032] In preferred embodiments, notches 170 have sufficient size in length and depth to receive either a lengthwise lower edge 123 of a sidewall 118 or a shorter width-wise lower edge 125 of an endwall 120 of platform 112 . In one configuration, shown in FIGS. 8 and 9 , a pair of notches 170 receive and support a first endwall 125 at a raised height, to support platform 112 in an angled arrangement along the length of platform 112 , with the second endwall of the platform supported at a lower height, typically by a support surface such as the floor.
[0033] In an alternate configuration, shown in FIGS. 10 and 11 , a pair of notches 170 receive the edge 123 of a sidewall 118 along the length of platform 112 . In this configuration, the support element 114 supports the sidewall edge 123 at a raised height, supporting platform 112 at an angled arrangement along the shorter width of platform 112 , with the opposite sidewall of the platform 112 supported at a lower height, typically by a support surface such as the floor. In certain embodiments, more than one support element 114 with parallel aligned notches 170 can be arranged and spaced along the length of a sidewall to provide stability via support points spaced along the length of the platform.
[0034] In certain angled arrangements, for example as illustrated in FIGS. 8-11 , foot portions 155 assist in supporting, aligning and stabilizing the upper platform over the support elements. For example, foot portions 155 can be sized and placed so the lower surface of the foot portion rests upon the upper surface of a ledge portion 137 , such as the short ledge portions illustrated. Preferably, the foot portions 155 are made from a non-slip material to assist in supporting the platform without undesired movement.
[0035] Notches 170 preferably have a length and depth sufficient to inhibit the edges of the platform 112 from slipping out of the notches 170 during use of an angled arrangement. In certain optional embodiments, a non-slip texture or surface material may be mounted in the notches 170 and/or along the lower edges of the platform's sidewalls and end walls to further reduce the risk of slippage during use. In still further embodiments, separate engagement features such as fasteners could be used to secure the platform sidewall or endwall in a notch with a desired placement and/or orientation. Examples of such engagement features include pegs or gear teeth extending upward within notches 170 , below the height of the upper plane of top section 131 , which engage corresponding openings or gearing on the lower edges of the platform.
[0036] FIG. 12 shows another embodiment of a generally rectangular support element 180 for use with platform 112 and having an upper portion 182 and a lower portion 184 . As illustrated, the support element 180 includes a closed center with two perpendicularly-opposed notches 190 and 192 . The profile of the notches 190 and 192 may be sized to accommodate different lower surfaces of a platform 112 or to allow support element 180 to be used to support different sizes or models of platforms. For example, notch 190 may be correspond to the profile of the lower edge of endwalls 125 of platform 112 , thereby allowing platform 112 to be supported in a lengthwise angled arrangement, similar to that shown in FIGS. 8 & 9 . Likewise, notch 192 may be sized to correspond to the radius and thickness of the lower edge of sidewalls 123 of platform 112 , thereby allowing platform 112 to be supported in a widthwise angled arrangement upon two support elements 180 , similar to that shown in FIGS. 8 & 9 . The notches 190 and 192 may optionally be laterally offset towards one side of the support element to facilitate better fitment when platform is placed in an angled orientation. In certain embodiments, the notches may form channels which may be fully or partially-continuous across the length of upper portion 182 . The notches may be also be non-continuous, such as notch 192 , which is fully intersected by notch 190 .
[0037] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An adjustable stepping structure for aerobic exercise is disclosed having a platform and a plurality of support elements. The support elements include a downwardly arcuate notch or channel for receiving a sidewall or endwall of the platform, allowing the platform to be arranged in multiple angled orientations. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to single point mooring devices for offshore mooring of cargo vessels and transfer of cargo to and from the vessels and consists particularly in novel means for transferring multiple fluids while eliminating any possibility of cross-leakage of the fluids.
Single mooring point buoys heretofore devised have generally embodied sealed swivel joints located in such positions that extremely undesirable cross-leakage between the fluids may result in case of leakage in the swivel joints. Furthermore, such equipment, generally, has been of the catenary anchor chain type in which the sealed swivels are carried by the floating elements of the buoy and do not carry heavy loads.
SUMMARY OF THE PRESENT INVENTION
Accordingly, it is an object of the present invention to provide a single point mooring apparatus of the single anchor leg type in which the fluid line swivel connections are incorporated in a rugged base structure anchored to the sea floor and in which danger of cross-leakage of the fluids, even in the case of failure of a swivel packing, is avoided.
Another object is to provide novel emergency sealing means for a swivel joint of the above type.
In accordance with the present invention a load-carrying central pipe shaft projects upwardly from rugged base structure anchored to the sea floor. A transfer chamber near the upper end of this pipe shaft is closed by a structural top wall and the side wall of the transfer chamber has one or more apertures for communicating the transfer chamber with the interior of an annular housing rotatably and sealingly mounted about the transfer chamber. A second transfer chamber is mounted on the upper end of the load-carrying central pipe shaft and is sealed from the first transfer chamber by the mentioned structural top wall. The second transfer chamber has one or more apertures in its side wall communicating with a second housing rotatably and sealingly mounted abreast of the second transfer chamber.
Cargo fluid connections with pipes leading to the vessel extend through the load-carrying central pipe shaft into the first and second transfer chambers.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is an elevation of a single anchor leg type of mooring buoy embodying the invention.
FIG. 2 is a plan view showing the base portion of the buoy.
FIG. 3 is in part an enlarged side elevation and in part a vertical transverse section on the longitudinal center line of the base structure.
FIG. 4 is a still further enlarged vertical transverse section of one of the sealing swivel joints.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The buoy consists in general of rugged base structure generally designated A with upstanding, central swivel assembly B and an upper float part C connected to the base structure by a chain D. The float part C incorporates a mooring bracket 6 for connection to the mooring line 6a leading to the vessel being serviced. Any suitable float construction C may be utilized, since the details of this construction, in themselves, do not constitute the present invention. Chain D is connected to the base structure through a swivel E.
The base structure A, B, as best shown in FIG. 3, includes the sufficiently wide and rugged base plate construction 7 resting on and secured to the seal floor, as by means of pilings 8 (FIG. 1). Primary fluid pipes 9 and 10 on the sea floor connect with the bottom of the rugged, upstanding, load-carrying central shaft-pipe 11 which extends through and is rigidly secured to base plate construction 7. Near the upper extremity of shaft-pipe 11, there is a transfer chamber 12, forming a part of the interior of shaft-pipe 11 and closed at the top by a structural wall 13. Rotatably received about the upper portion of shaft-pipe 11, by means of longitudinally spaced, sealing swivel joints 14 and 15, is the chambered housing 16. As indicated in FIG. 2, a pair of hose arms 17 and 18 project diametrically oppositely from housing 16, being connected thereto by swivel joints, generally designated 19 and 20, for coupling to the pair of main cargo pipes 21 and 22 leading to the vessel being serviced. A plurality of apertures 23 in the side wall of transfer chamber 12 provide communication between the transfer chamber and the interior of rotatable housing 16.
Mounted above structural top wall 13 of shaft-pipe 11 and rigid therewith is a relatively short, cylindrical structure 25 forming the upper transfer chamber 35 which is closed at the top by an integral transverse wall 26, the side wall of structure 25 having a plurality of apertures 27 for communcation with the interior of a second housing 28 rotatably and sealingly mounted on structure 25 by swivel joints 29 and 30. Housing 28 has a lateral nipple 31 for connection to the secondary fluid pipe or hose 32 leading to the cargo vessel.
All of the cargo pipes or hoses 21, 22 and 32 leading to the vessel are shown as supported by a buoyancy tank 35 from which depends the triangular structure 36 supporting the stabilizing ballast 37, as disclosed and claimed in a copending application, Ser. No. 424,958 filed Dec. 17, 1973, by Kristen I. Pedersen and assigned to the assignee of the present invention now U.S. Pat. No. 3,883,912. The upper transfer chamber 35 communicates through a central downward pipe 38 with a secondary fluid pipe 39 leading along the seabed to the shore or other terminal.
FIG. 4 illustrates in detail one of the swivel seal joints in enlarged transverse section. The joint includes the inner body 45 which securely engages the load-carrying central shaft structure 16 and outer body part 46 which rotates on ball bearings 47 and is secured to one of the chambered housings 16 and 28. Primary and secondary seals are provided at 48, 49, 50, and 51, which, when in normal working order, prevent the escape of cargo fluid or the leakage of water into the transfer or rotary chambers. All of the above is more or less conventional and commercially obtainable. Of especial significance is the emergency seal ring 53 interposed between the uppermost ball bearings 47 and the adjacent secondary seal 51. The emergency seal, conveniently, is made primarily of synthetic rubber, as "Buna-N", with the Teflon face 54 for bearing against the lined seal area 55, for instance, of Monel. Emergency seal 53, etc., is normally retracted, as shown in FIG. 4. However, actuating fluid may be applied to the cupped rear face of emergency seal 53 through a short cross bore 56 with connection fitting 57 for strongly actuating the emergency seal against opposing swivel body 45 to effectively prevent any leakage along the interface between swivel body parts 45 and 46. Such actuation of the emergency seal may be manually initiated from the surface.
OPERATION
With base construction 7 firmly secured to the seabed and float portion C anchored thereto by the chain D, a vessel to be loaded or unloaded will be secured by the mooring line 6a to mooring bracket 6. The entire float C is free to rotate relative to structures A and B to permit swinging of the vessel about the buoy under the influence of wind, wave, and current action. Fluid unloading or loading hoses 21 and 22, for instance for the main fluid cargo, are then connected to hose arms 17 and 18; and hose 32, for instance, for a different fluid, such as bunker fuel, is connected to nipple 31. Since hose arms 17 and 18 and nipple 31 are mounted, respectively, on rotatable housings 16 and 28, these mountings, normally, will remain fluid-tight and interference between the hoses and the buoy will be avoided during swinging of the vessel about the buoy. While connections for only two different fluids are shown, any number of different fluids may be handled by a buoy embodying the principles of the present invention simply by duplicating the supplementary and structurally separate transfer chambers and associated rotatable housings, as 25, 28, on top thereof with corresponding sealed and rotatably mounted housings for connection to the additional hose lines leading to the vessel.
In the present instance, cargo lines 21 and 22 from the vessel connect through the main load-carrying shaft-pipe 11 with a pipe or pipes 9 and 10 leading along the seabed to the shore or other terminal. Secondary line 39 connects with the angled pipe 38 which extends securely and sealingly through the wall of shaft-pipe 11, thence turns upwardly, passing concentrically through first transfer chamber 12 and its structural top wall 13 into upper transfer chamber 35. Where other vessel hose lines are to be accommodated, the additional seabed connections may extend along or through shaft-pipe wall 11 concentrically through the intervening surmounted transfer chambers and their structural top walls.
Of particular significance is the fact that transfer chambers 12, 35 and their corresponding rotary housings 16 and 28 and the swivel seal joints for the respective housings are spaced apart and fully and structurally segregated so that the continuing efficacy of the swivel seals need not be relied upon to prevent cross-leakage of the different fluids being handled. Any leakage through the swivel joints will pass into the surrounding water and not contaminate the transported fluids. The invention may be modified in various respects as will occur to those skilled in the art, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated. | A single anchor leg type single point mooring and cargo transfer buoy has a load-carrying central shaft pipe for anchoring on the sea bottom and having a plurality of structurally segregated transfer chambers about which rotatable housings are sealingly mounted. Cargo vessel piping connects with these rotatable housings which communicate with the sea floor piping through connections extending longitudinally through the central shaft pipe and through apertures in the central shaft pipe wall. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/730,932 (Attorney Docket No. 20920-712.301), filed Mar. 24, 2010, which is a continuation of U.S. patent application Ser. No. 11/280,530 (Attorney Docket No. 20920-712.201), filed on Nov. 15, 2005, which claims the benefit of priority of U.S. Provisional Patent Application No. 60/628,856 (Attorney Docket No. 20920-712.101), filed on Nov. 16, 2004, the contents of each are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical devices, systems and methods. In preferred embodiments, the present invention relates to methods and apparatuses for effecting lung volume reduction by aspirating isolated segments of lung tissue.
[0004] Chronic obstructive pulmonary disease is a significant medical problem affecting 16 million people or about 6% of the U.S. population. Specific diseases in this group include chronic bronchitis, asthmatic bronchitis, and emphysema. While a number of therapeutic interventions are used and have been proposed, none are completely effective, and chronic obstructive pulmonary disease remains the fourth most common cause of death in the United States. Thus, improved and alternative treatments and therapies would be of significant benefit.
[0005] Lung function in patients suffering from some forms of chronic obstructive pulmonary disease can be improved by reducing the effective lung volume, typically by resecting diseased portions of the lung. Resection of diseased portions of the lungs both promotes expansion of the non-diseased regions of the lung and decreases the portion of inhaled air which goes into the lungs but is unable to transfer oxygen to the blood. Lung reduction is conventionally performed in open chest or thoracoscopic procedures where the lung is resected, typically using stapling devices having integral cutting blades. Although these procedures appear to show improved patient outcomes and increased quality of life, the procedure has several major complications, namely air leaks, respiratory failure, pneumonia and death. Patients typically spend approximately 5-7 days in post-op recovery with the majority of this length of stay attributed to managing air leaks created by the mechanical resection of the lung tissue.
[0006] In an effort to reduce such risks and associated costs, minimally or non-invasive procedures have been developed. Endobronchial Volume Reduction (EVR) allows the physician to use a catheter-based system to reduce lung volumes. With the aid of fiberoptic visualization and specialty catheters, a physician can selectively collapse a segment or segments of the diseased lung. An occlusal device is then positioned within the lung segment to prevent the segment from reinflating. By creating areas of selective atelectasis or reducing the total lung volume, the physician can enhance the patient's breathing mechanics by creating more space inside the chest wall cavity for the more healthy segments to breath more efficiently.
[0007] Additional improvements to EVR are desired. A delivery system is desired which can position an occlusal device within a desired segment of a lung passageway with high accuracy. Such a delivery system should be easy to use, should allow interchangeability of a variety of instruments, and should allow delivery of multiple occlusal devices. It is desired that such delivery of multiple occlusal devices be achieved while maintaining evacuation of a diseased region of the lung. It is also desired to provide a system which utilizes conventional bronchoscopes to deliver the occlusal devices to the lung passageways. Such utilization should be easy to operate and should not interfere with additional therapies which utilize the bronchoscope. At least some of these objectives are met by the current invention.
[0008] 2. Description of the Background Art
[0009] Patents and applications relating to lung access, diagnosis, and treatment include U.S. Pat. Nos. 6,709,401; 6,585,639; 6,527,761; 6,398,775; 6,287,290; 5,957,949; 5,840,064; 5,830,222; 5,752,921; 5,707,352; 5,682,880; 5,660,175; 5,653,231; 5,645,519; 5,642,730; 5,598,840; 5,499,625; 5,477,851; 5,361,753; 5,331,947; 5,309,903; 5,285,778; 5,146,916; 5,143,062; 5,056,529; 4,976,710; 4,955,375; 4,961,738; 4,958,932; 4,949,716; 4,896,941; 4,862,874; 4,850,371; 4,846,153; 4,819,664; 4,784,133; 4,742,819; 4,716,896; 4,567,882; 4,453,545; 4,468,216; 4,327,721; 4,327,720; 4,041,936; 3,913,568 3,866,599; 3,776,222; 3,677,262; 3,669,098; 3,542,026; 3,498,286; 3,322,126; WO 98/48706; WO 95/33506, and WO 92/10971.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention provides methods, systems, and devices for performing lung volume reduction in patients suffering from chronic obstructive pulmonary disease or other conditions where isolation of a lung segment or reduction of lung volume is desired. These methods, systems, and devices are likewise suitable for the treatment of bronchopleural fistula. The methods are minimally invasive with instruments being introduced through the mouth (endotracheally) and rely on isolating the target lung tissue segment from other regions of the lung and occluding various lung passageways with the use of occlusal stents.
[0011] In a first aspect of the present invention, an occlusal stent delivery system is provided for delivering an occlusal stent to a target lung passageway. In preferred embodiments, the delivery system includes a visualization instrument configured for endobronchial advancement into a lung passageway leading to the target lung passageway. The instrument having a proximal end, a distal end, a working lumen extending therethrough, means for visualization near the distal end, and an occlusive member disposed near its distal end which is configured to be expandable to occlude the lung passageway. In addition, the system includes a delivery catheter having a proximal end, a distal end and a receptacle formable within its distal end for loading the occlusal stent therein. The delivery catheter is configured to be advanced through the working lumen of the visualization instrument so that its distal end extends beyond the distal end of the visualization instrument and wherein its distal end is retractable so that retraction of its distal end releases the occlusal stent to the target lung passageway. Typically, the distal end of the delivery catheter has portions of variable flexibility to allow the catheter to be advanced through a potentially curved working lumen without applying forces sufficient to redirect the visualization instrument.
[0012] In preferred embodiments, the system further includes a clamp connector. In some embodiments, the clamp connector comprises a connector body having a passageway therethrough, and means for connecting the connector body to a visualization instrument having a working lumen so that insertion of an instrument through the passageway of the connector body inserts the instrument into the working lumen of the visualization instrument. In preferred embodiments, the passageway and the working lumen are non-axially aligned during connection. In some embodiments, the clamp connector comprises a connector body having a first end, a second end and an arc-shaped arm connecting the first and second ends, wherein the passageway passes through the first and second arms. However, it may be appreciated that the connector body many have a variety of suitable shapes and forms. Typically, the visualization instrument has a handle to which the connector body is attachable. The means for connecting may have a variety of forms including a fitting, such as a quick connector. In some embodiments, the quick connector comprises a side-action quick connector which allows the connector to be attached and detached from a side approach. Typically, the delivery catheter includes a handle at its distal end and the clamp connector includes a locking mechanism which is capable of locking the handle of the delivery catheter to the clamp connector. Such locking holds the delivery catheter in place in relation to the visualization instrument. In some embodiments, the locking mechanism tightens the passageway through the connector body to hold the at least a portion of the catheter by frictional forces. The locking mechanism may comprises a screw, knob or tensioning lever, among other mechanisms. While the delivery catheter is locked in place, the occlusal stent may be deployed from the delivery catheter by manipulation of the handle of the delivery catheter.
[0013] In preferred embodiments, the delivery catheter comprises positioning rod, a tubular shaft extending from its proximal end to its distal end, and a handle positioned at its proximal end. The positioning rod is disposed within the tubular shaft and is fixedly attached to the handle. A receptacle formable within the distal end of the delivery catheter is disposed within the tubular shaft distal of the distal end of the positioning rod. The distance between the distal end of the positioning rod and the distal end of the tubular shaft is the axial length of the receptacle. The tubular shaft is slidable in relation to the positioning rod so that sliding of the tubular shaft shortens the axial length of the receptacle exposing the occlusal stent. When the occlusal stent has a self-expanding design, exposure of the occlusal stent deploys the occlusal stent within the lung passageway. In some embodiments, the occlusal stent is self-expanding in free space to a configuration that has an approximately 11 mm outer diameter. Alternatively, the occlusal stent may be expanded by alternative mechanisms after it has been released into the lung passageway. In either case, the occlusal stent may be comprised of a wire structure or any other type of framework at least partially encapsulated in a polymer. The wire structure is used as an example in the following descriptions but it can be appreciated that the framework can be of a variety of types.
[0014] Typically, the positioning rod comprises a main body coil extending along the positioning rod terminating at a plunger tip. In some embodiments, the main body coil has an axial length in the range of approximately 80 to 100 cm and the main body coil is comprised of stainless steel wire.
[0015] In some embodiments, the visualization instrument comprises a bronchoscope. It may be appreciated that any suitable bronchoscope may be used, including conventional bronchoscopes. A principal advantage of the present invention is that it allows a user to modify a conventional bronchoscope for use in delivery of occlusal stents in a convenient and economical manner. However, it may also be appreciated that other instruments or catheters may be used which provide viewing or visualization capabilities. Thus, the visualization instrument may further comprise a sheath having a proximal end, a distal end, a lumen extending therethrough and the occlusive member disposed near its distal end, the lumen configured to receive the bronchoscope so that the occlusive member is disposed near the distal end of the bronchoscope. The sheath typically comprises a flexible tubular body having a length in the range from 40 cm to 70 cm, an inside lumen diameter in the range from 1.5 mm to 10 mm, and a wall thickness in the range from 0.2 mm to 0.7 mm.
[0016] In a second aspect of the present invention, a loading system is provided. In preferred embodiments, the loading system includes an occlusal stent, a loading body, and a loading mandrel. Again, the occlusal stent is transitionable between an expanded configuration and a contracted configuration. The loading body has a wide-mouthed end and a narrow-mouthed end, wherein the wide-mouthed end is configured to receive the occlusal stent in the expanded configuration and the narrow-mouthed end is configured to hold the occlusal stent in the contracted configuration. The loading mandrel has a proximal end, a distal end, and an attachment device disposed near its distal end that is removably attachable to the occlusal stent. The attachment device may be comprised of a hook, clasp, fastener or magnet, to name a few. The mandrel is configured to load the removably attached occlusal stent into the wide-mouthed end and move the occlusal stent to the narrow-mouthed end.
[0017] In preferred embodiments, the loading body comprises a loading receptacle within the wide-mouthed end, wherein the loading receptacle is sized to receive the occlusal stent in the expanded configuration. The loading receptacle may have any suitable size or shape. Typically, the loading receptacle is cylindrical in shape and has a diameter in the range of approximately 10 to 13 mm. In addition, loading body comprises a holding tube within the narrow-mouthed end, wherein the holding tube is sized to receive the occlusal stent in the contracted configuration. Similarly, the holding tube may have any suitable size or shape, typically having a cylindrical shape with a diameter in the range of approximately 2 to 2.5 mm. Further, in preferred embodiments, the loading body comprises a restrictor disposed between the loading receptacle and the holding tube, wherein the restrictor has a funnel shape to transition the occlusal stent from the expanded configuration to the contracted configuration. In some embodiments, loading mandrel includes a first marking near its distal end and the loading body includes a second marking near its narrow-mouthed end, wherein alignment of the first marking with the second marking positions the occlusal stent within the narrow-mouthed end.
[0018] In some embodiments, the loading system further comprises a delivery catheter having a proximal end, a distal end and a receptacle formable within its distal end for loading the occlusal stent therein. The narrow-mouthed end of the loading body is typically configured to mate with the distal end of the delivery catheter. The occlusal stent may then be moved from the narrow-mouthed end to the receptacle within the distal end of the delivery catheter with the use of the loading mandrel. Further, in some embodiments the catheter is provided pre-positioned to the narrow-mouthed end of the loading body and the occlusal stent is provided pre-positioned and or pre-attached to the wide-mouthed end and or pre-connected to the positioning rod of the catheter.
[0019] In a third aspect of the present invention, methods of delivering an occlusal stent to a lung passageway within a lung of a patient are provided. In preferred embodiments, such methods include providing a visualization instrument, wherein the instrument has a proximal end, distal end, a working lumen therethrough, means for visualization near the distal end, and an occlusive member disposed near its distal end which is configured to be expandable to occlude the lung passageway. The visualization device is advanced through a trachea of the patient to a first location with the lung passageway. The lung passageway is then occluded at the first location with the occlusive member and the lung passageway evacuated. The method further includes providing a delivery catheter having a proximal end, a distal end, and an occlusal stent loaded within a receptacle within its distal end. The delivery catheter is advanced through the working lumen of the visualization instrument so that the distal end of the delivery catheter extends beyond the distal end of the visualization instrument to a second location within the lung passageway. The distal end of the delivery catheter is then retracted which releases the occlusal stent from the receptacle at the second location within the evacuated lung passageway.
[0020] Such methods may be performed within lung passageways of various dimensions, shapes and branching patterns. For example, lung passageway may be comprised of a main passageway and at least one branch passageway. The first location may be disposed within the main passageway and the second location disposed within one of the at least one branch passageways. Thus, the distal end of the delivery catheter may be steered or guided in various directions as it is advanced beyond the visualization instrument to reach a desired branch passageway.
[0021] Typically, the methods further comprise withdrawing the delivery catheter from the visualization instrument after releasing the occlusal stent while the lung passageway remains evacuated. Another delivery catheter having a proximal end, a distal end, and another occlusal stent loaded within a receptacle within its distal end may then be provided. This may be the delivery catheter that was removed with a new occlusal stent loaded therein, or a different delivery catheter that has been preloaded with an occlusal stent. The another delivery catheter is then advanced through the working lumen of the visualization instrument so that the distal end of the another delivery catheter extends beyond the distal end of the visualization instrument to a third location within the evacuated lung passageway. The third location may be disposed within another of the at least one branch passageways.
[0022] Again, the delivery catheter typically comprises a tubular shaft extending from its proximal end to its distal end wherein the occlusal stent is disposed within the tubular shaft within the distal end of the catheter. Thus, releasing comprises withdrawing the tubular shaft to expose the occlusal stent. In preferred embodiments, the delivery catheter comprises a handle disposed at its proximal end and the tubular shaft is slidably connected with the handle by a handle button or any other hand-operated feature such as a loop or trigger, henceforth referred to as button. In these embodiments, withdrawing comprises moving the handle button to withdraw the tubular shaft.
[0023] In some embodiments, the visualization instrument has a handle section near its proximal end, and the method further comprises connecting a clamp connector to the handle section of the visualization instrument. Typically, the clamp connector has a passageway therethrough so that advancing the delivery catheter comprises passing the distal end of the delivery catheter through the passageway of the clamp connector and into the working lumen of the visualization instrument. The working lumen is typically accessible via an access port, which extends through the proximal end and typically the handle section of the visualization instrument. The clamp connector can attach directly to the working lumen access port or elsewhere on the visualization instrument handle section as described in the following detailed descriptions. Again, the delivery catheter typically comprises a tubular shaft extending from its proximal end to its distal end and a handle disposed at its proximal end. The clamp connector may further include a locking mechanism wherein the method would further comprise actuating the locking mechanism to lock the handle of the delivery catheter to the clamp connector. The handle of the delivery catheter can be provided in a variety of configurations, such as a configuration that does not enter the working channel of the bronchoscope as well as a configuration that can enter the working channel of the bronchoscope, and combinations thereof. The clamp connector can also be provided in many configurations, wherein the clamp connector physically attaches to a portion of the bronchoscope, typically in the handle section and sometimes directly to the access port, and allows access of the catheter to the bronchoscope working channel. The clamp connector can be an item provided separately, or can be provided as an integral piece of the delivery catheter, and can be reusable or disposable.
[0024] When the tubular shaft is slidably connected with the handle of the catheter by a handle button, releasing may comprise moving the handle button to withdraw the tubular shaft and expose the occlusal stent. Releasing may also comprise expanding the occlusal stent to occlude the lung passageway.
[0025] In a fourth aspect of the present invention, methods are provided for using the loading system. Such methods include providing a loading mandrel having a proximal end, a distal end and an occlusal stent removably attached to its distal end, wherein the occlusal stent is transitionable between an expanded configuration and a contracted configuration. These methods also include providing a loading body having a wide-mouthed end and a narrow-mouthed end, wherein the wide-mouthed end is configured to receive the occlusal stent in the expanded configuration and the narrow-mouthed end is configured to hold the occlusal stent in the contracted configuration. The loading mandrel is positioned within the loading body so that the occlusal stent is near the wide-mouthed end. The loading mandrel is then manipulated to load the occlusal stent into the wide-mouthed end and move the occlusal stent to the narrow-mouthed end within the loading body.
[0026] When the loading body comprises a loading receptacle within the wide-mouthed end, manipulating the loading mandrel may comprise moving the loading mandrel relative to the loading body so that the occlusal stent is positioned within the loading receptacle. When the loading body includes a restrictor adjacent to the loading receptacle, manipulating the loading mandrel may comprise moving the loading mandrel relative to the loading body so that the occlusal stent enters the restrictor. And when the loading body includes a holding tube adjacent to the restrictor, manipulating the loading mandrel may comprise moving the loading mandrel relative to the loading body so that the occlusal stent is positioned within the holding tube. In some embodiments, the loading mandrel includes a first marking near its distal end and the loading body includes a second marking near its narrow-mouthed end. In these embodiments, the method may further comprise aligning the first marking with the second marking indicating that the occlusal stent is positioned within the narrow-mouthed end. The methods may further comprise detaching the occlusal stent from the loading mandrel.
[0027] A delivery catheter having a proximal end, a distal end and a receptacle formable within its distal end for loading the occlusal stent therein may also be provided. Such methods may then further include transferring the occlusal stent from the narrow-mouthed end of the loading body to the receptacle of the delivery catheter. To accomplish this, the method may further comprise mating the distal end of the delivery catheter with the narrow-mouthed end of the loading body prior to the transferring step. Transferring may also comprise advancing a loading mandrel through the open-mouthed end of the loading body which pushes the occlusal stent into the distal end of the delivery catheter. The delivery catheter loading system and occlusal stent can be provided separately in which case the user may mate the elements for transferring, or the pieces can be provided pre-positioned together or in a mated configuration so that the user only has to transfer the stent into the catheter through the pre-positioned loading system.
[0028] It may be appreciated that the delivery system and/or loading system may be used for a variety of applications. For example, components of the delivery system may be used to deliver non-occlusal tracheobronchial stents, bronchopulmonary fistula plugs or stents, or occlusal stents for the treatment of tuberculosis. Further, components of the delivery system may be modified for to deliver vascular stents, vascular grafts or vascular occlusal devices to the vascular system to treat a variety of vascular ailments. Likewise, the loading system may be used to load a variety of stent-like devices within instruments and catheters having a receptacle for receiving the devices. Further, the clamp connector of the present invention may be used for the passage of any suitable instrument therethrough, such as instruments for implant removal, endoluminal injection (such as of a therapeutic agent, a hemostatic agent, etc.), specimen collection (such as for a biopsy), inspection, or other treatment, such a radiation therapy, etc.
[0029] Other objects and advantages of the present invention will become apparent from the detailed description to follow, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates an embodiment of a delivery system of the present invention.
[0031] FIG. 2 provides a cross-sectional side view of an embodiment of an occlusal stent delivery catheter.
[0032] FIG. 3 provides a cross-sectional side view of a tubular shaft of the delivery catheter of FIG. 2 .
[0033] FIG. 4 provides a cross-sectional side view of the positioning rod of FIG. 2 .
[0034] FIGS. 5 , 6 - 6 A, 7 illustrates various views of an embodiment of a clamp connector.
[0035] FIGS. 8A-8B illustrate an embodiment of a clamp connector having the form of a bracket.
[0036] FIGS. 8C-8E illustrate an embodiment of a clamp connector having the form of an elongate holder.
[0037] FIGS. 9-9A illustrate an embodiment of an occlusal stent.
[0038] FIG. 10A illustrates an exploded view of an embodiment of a loading system of the present invention.
[0039] FIG. 10B provides a top view of a loading body having a mandrel positioned therein.
[0040] FIGS. 11A-11D illustrate loading of an occlusal stent into the loading system.
[0041] FIG. 11E-11G illustrate transferring of an occlusal stent to a delivery catheter.
[0042] FIGS. 12A-12C illustrate an alternative method of loading a delivery catheter with an occlusal stent.
[0043] FIGS. 13A-13C illustrate an similar method of loading a delivery catheter to that of FIGS. 12A-12C .
[0044] FIGS. 14A-14C illustrates methods of using the occlusal stent delivery system of the present invention within lung passageways.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Lung volume reduction is performed by collapsing a target lung tissue segment, usually within lobar or sub-lobular regions of the lung which receive air through a single lung passage, i.e., segment of the branching bronchus which deliver to and receive air from the alveolar regions of the lung. Such lung tissue segments are first isolated and then collapsed by aspiration of the air (or other gases or liquids which may be present) from the target lung tissue segment. Lung tissue has a very high percentage of void volume, so removal of internal gases can reduce the lung tissue to a small percentage of the volume which it has when fully inflated, i.e. inflated at normal inspiratory pressures.
[0046] The methods of the present invention rely on accessing the target lung tissue segment using an occlusal stent delivery system 10 adapted to be introduced endotracheally into the bronchus of the lung. An exemplary delivery system 10 is illustrated in FIG. 1 . As shown, the system 10 comprises a bronchoscope 12 having a proximal end 14 , a distal end 16 and at least a working lumen 18 and a scope lumen 20 extending from the proximal end 14 to the distal end 16 . Additional lumens, such as an aspiration lumen 22 , may also extend therethrough. The bronchoscope 12 also includes a handle 24 disposed near the proximal end 14 . The handle 24 is formed to include a sidearm 24 a which provides access to the working lumen 18 . The handle 24 also includes a connector 28 which permits attachment to an external viewing scope.
[0047] It may be appreciated that the bronchoscope 12 included in this embodiment of the system 10 of the present invention may be comprised of any suitable bronchoscope, including conventional bronchoscopes. Conventional bronchoscopes are available from a number of commercial suppliers. Particular bronchoscopes which may be used in the methods and assemblies of the present invention are commercially available from Olympus and Pentax. A principal advantage of the present invention is that it allows a user to modify a conventional bronchoscope for use in delivery of occlusal stents in a convenient and economical manner. However, it may also be appreciated that other instruments or catheters may be used which provide viewing or visualization capabilities.
[0048] In this embodiment, the system 10 also includes a sheath 30 having an occlusive member 32 disposed near its distal end, a full description of which is provided in U.S. Pat. No. 6,585,639[Attorney Docket No. 017534-001300US], assigned to the assignee of the present invention and incorporated by reference for all purposes. The sheath 30 includes a flexible tubular body having a distal end and an occlusive member 32 disposed at or near the distal end of the tubular body. Typically, the occlusive member will be formed from an inflatable elastomeric material which, when uninflated, lies closely over an exterior surface of the distal end of the flexible tubular body. Upon inflation, the material of the occlusive member will simply stretch and permit radial expansion. The elastic nature of the member will permit the member to conform to irregular geometries of a target lung passageway to provide for effective sealing.
[0049] The system 10 of FIG. 1 also includes an occlusal stent delivery catheter 40 which is positionable within the working lumen 18 of the bronchoscope 12 . The catheter 40 comprises a tubular shaft 41 having a distal end 42 , wherein the distal end 42 is extendable beyond the distal end 16 of the scope 12 . This may be achieved by slidably advancing the catheter 40 within the working lumen 18 . The catheter 40 also includes a positioning rod 44 that is disposed within the tubular shaft 41 . The positioning rod 44 is used to expel an occlusal stent 46 from the distal end 42 of the catheter 40 , as will be described and illustrated in later sections. The catheter 40 is positionable within the working lumen 18 of the scope 12 by advancement through the sidearm 24 a of the handle 24 .
[0050] The catheter 40 also includes a handle 48 which typically remains outside of the sidearm 24 a , though inn some optional configurations an extension of the handle 48 can enter the 24 a sidearm or the working lumen 18 of the bronchoscope. Both the tubular shaft 41 and the positioning rod 44 are attached to the handle 48 so that gross movement of the handle 48 toward or away from the sidearm 24 a advances or retracts the catheter 40 within the working lumen 18 . To assist in positioning the catheter 40 within the working lumen 18 and to lock portions of the catheter 40 in relation to the scope 12 , a clamp connector 60 may be used. The clamp connector 60 may be joined with the sidearm 24 a by a quick connector 62 , however any connecting mechanism may be used. The catheter 40 is advanceable through the clamp connector 60 and the handle 48 is lockable to the clamp connector 60 by a locking mechanism 64 . As shown in later figures, the clamp connector can assume other shapes and configurations and can attach to other portions of the bronchoscope in the bronchoscope handle area with a variety of connection mechanisms.
[0051] As will be described in later sections, the positioning rod 44 is fixedly attached to the handle 48 and the tubular shaft 41 is slidably attached to the handle 48 . Thus, locking of the handle 48 to the clamp connector 60 using locking mechanism 64 in turn locks the positioning rod 44 in relation to the scope 12 . The tubular shaft 41 may then be slidably advanced or retracted in relation to the scope 12 and the positioning rod 44 by movement of a handle button 50 on the handle 48 . The handle button 50 is fixedly attached to the tubular shaft 41 . In this manner, the tubular shaft 41 may be retracted to deploy the occlusal stent 46 . It may be appreciated that such a handle button 50 is an example mechanism for achieving such movement of the tubular shaft 41 and that other suitable mechanisms may be used.
Occlusal Stent Delivery Catheter
[0052] FIG. 2 provides a cross-sectional side view of an embodiment of an occlusal stent delivery catheter 40 . As shown, the catheter 40 includes a positioning rod 44 having a distal end 45 , a tubular shaft 41 and a handle 48 . The positioning rod 44 is disposed within the tubular shaft 41 and is fixedly attached to the handle 48 , in this embodiment by a set screw 72 however any mechanism can be used. The tubular shaft 41 is fixedly attached to a catheter adapter 70 which is sized to fit at least partially within the handle 48 . The adapter 70 is slidably attached to the handle 48 with the use of a handle button 50 . The handle button 50 is attached to the catheter adapter 70 and shaped to extend through a slot (not shown) in the handle 48 so that the button 50 is able to slide along the slot thereby moving the tubular shaft 41 in relation to the handle 48 .
[0053] The handle button 50 is positionable so that a receptacle 80 is formed within the tubular shaft 41 between the distal end 45 of the positioning rod 44 and the distal end 42 of the tubular shaft 41 . The receptacle 80 is sized to hold an occlusal stent 46 in a contracted form. In preferred embodiments, the maximum axial length of the receptacle 80 is in the range of approximately 20 to 30 mm. Movement of the button 50 along the slot retracts the tubular shaft 41 , shortening the axial length of the receptacle 80 until the distal end 45 of the positioning rod 44 meets the distal end 42 of the tubular shaft 41 . At this point the receptacle 80 is completely diminished and the occlusal stent 46 is fully exposed and released.
[0054] FIG. 3 provides a cross-sectional side view of the tubular shaft 41 of FIG. 2 . As shown, the tubular shaft 41 is connected with a catheter adapter 70 . In this embodiment, the connection is achieved with adhesive and heat shrink tubing 74 , however any connection methods and materials may be used. In addition, the tubular shaft 41 has a end portion 52 that terminates at the distal end 42 of the shaft 41 . In preferred embodiments, the end portion has an axial length in the range of approximately 20 to 120 mm. The end portion 52 is typically comprised of a more flexible material than the remainder of the tubular shaft 41 . Such differences in flexibility provide sufficient rigidity throughout the shaft 41 while maintaining maneuverability and kink resistance near the distal end 42 . In addition, the end portion 52 typically has a slightly larger diameter than the remainder of the shaft 41 to accommodate the cross-sectional diameter of the collapsed stent 46 while minimizing the diameter of the remainder of the shaft 41 which minimizes friction within the visualization instrument. In preferred embodiments, the overall length of the tubular shaft 41 and adapter 70 is in the range of approximately 30 to 34 inches.
[0055] The tubular shaft 41 may include markings 82 , as shown. The markings 82 may be comprised of ink or any suitable marking material. Any number of markings 82 may be present, such as a stripe approximately 20 mm from the distal end 41 and another approximately stripe 22.5 mm from the distal end 41 . Such markings 82 may be used to assist in positioning the distal end 41 in a passageway. The markings 82 may be observed through the scope 12 as the distal end 41 is manipulated within a lung passageway. Particular markings may be aligned with particular anatomical features to assist in proper placement of the stent 46 . For example, when a stent 46 is to be positioned within a relatively large lung passageway, a particular marking such as a distal-most marking may be aligned with the ostium associated with the target lung passageway. Whereas, when a stent 46 is to be positioned within a smaller lung passageway, a different marking, such as a proximal-most marking may be aligned with the ostium associated with the target lung passageway.
[0056] FIG. 4 provides a cross-sectional side view of the positioning rod 44 of FIG. 2 . In this embodiment, the positioning rod 44 is comprised of a main body coil 92 which extends along the length of the rod 44 terminating at a plunger tip 94 . Thus, the axial length of the main body coil 92 is in the range of 34 to 40 inches. Typically, the main body coil 92 has an inner diameter in the range of 0.030 to 0.040 inches. The main body coil 92 is comprised of 304 stainless steel wire, however any suitable material may be used. In this embodiment, the plunger tip 94 is comprised of 303 stainless steel and has a maximum outer diameter in the range of 0.075 to 0.085 inches. The positioning rod 44 also includes a push end hypotube 90 disposed within the main body coil 92 opposite to the plunger tip 94 . In this embodiment, the hypotube 90 is comprised of 304 stainless steel, however any suitable material may be used. The hypotube 90 has an inner diameter of approximately 0.023 inches and an outer diameter of approximately 0.0355 inches. In addition, the hypotube 90 has an axial length of in the range of 14 to 18 inches. Adjacent to the hyptotube 90 , within the main body coil 92 , is a strain relief coil 96 . In this embodiment, the strain relief coil 96 has an axial length in the range of 1 to 2 inches. The strain relief coil 96 is comprised of 304 stainless steel wire, however any suitable material may be used.
Clamp Connector
[0057] FIG. 5 provides a perspective view of an embodiment of a clamp connector 60 . The clamp connector 60 comprises a connector body 100 , a quick connector 62 , and a locking mechanism 64 . The connector body 100 may be comprised of any suitable material, such as a rigid thermoplastic, acetyl butyl styrene (ABS), Delrin.RTM. acetal resin, nylon, polycarbonate, metal, or various polymers, to name a few. The connector body 100 may also have any suitable form. In preferred embodiments, the body 100 has a C-shaped form, as shown, having a first end 102 , a second end 104 and an arc-shaped arm 106 therebetween. The body 100 has a passageway 108 that extends through the first and second ends 102 , 104 . Therefore, an instrument, such as the delivery catheter 40 may be passed through the passageway 108 so that the handle 48 of the catheter 40 is positioned at least partially within at least the second end 104 , typically so that the handle button 50 remains outside of the connector body 100 . By positioning the handle 48 at least partially within the second end 104 , the handle 48 can be locked in relation to the connector 60 with the use of the locking mechanism 64 . In some embodiments, the passageway 108 extending through the second end 104 has a split 110 . Such a split 110 may be seen in FIG. 5 and FIG. 7 . The split 110 allows the passageway 108 through the second end 104 to expand. At least a portion of the handle 48 may then be advanced into the expanded passageway 108 . A locking mechanism 64 , such as a screw, knob or quick release tensioning lever, may then be tightened, turned or actuated to close the split 110 . This in turn applies compressive forces to the handle 48 so that it is held by friction. It may be appreciated, however, that any suitable locking mechanism may be used. The button 50 may then be manipulated to move the tubular shaft 41 of the delivery catheter 40 while the handle 48 is locked to the connector 60 .
[0058] FIG. 6 provides a top perspective view of an embodiment of a clamp connector 60 . Again the clamp connector 60 is shown to have a first end 102 , a second end 104 and an arc-shaped arm 106 therebetween. A quick connector 62 is shown joined with the first end 102 , and a locking mechanism 64 is shown joined with the second end 104 . FIG. 6A illustrates a cross-sectional view along line A-A of FIG. 6 . This view illustrates the passageway 108 extending through the quick connector 62 , the first end 102 , and the second end 104 . In addition, this view illustrates the locking mechanism 64 . FIG. 7 provides another perspective view of the clamp connector 60 of FIG. 5 .
[0059] The clamp connector 60 provides a number of advantages. As mentioned, the clamp connector 60 provides a stable platform for introduction of the stent delivery catheter 40 and various other instruments into the working lumen 18 of the bronchoscope 12 . As described in this embodiment, the clamp connector fixes the position of the catheter or instrument to the bronchoscope, or optionally fixes a component of the catheter or instrument to the bronchoscope while another component of the catheter or instrument is free to advance or retract within the bronchoscope working lumen while the fixed catheter component remains stationary. In addition, the connector 60 provides for locking of these instruments in a fixed position relative to the bronchoscope. Further, various embodiments of the connector 60 include a quick connector 62 which allows the connector 60 to be quickly and easily attached and detached from the bronchoscope 12 . Some embodiments include a side-action quick connector 62 which allows the connector to be attached and detached from a side approach rather than an axial approach. In addition to being more ergonomic, this approach reduces any axial pushing or pulling on the bronchoscope 12 which could inadvertently move the bronchoscope from its desired position. Some embodiments of the connector 60 also include a seal or are attachable with a seal. Commercially available seals include Biopsy Valve (MAJ-210) provided by Olympus America, Inc. (Melville, N.Y.). Such seals may be mounted on the connector 60 for mating with the bronchoscope 12 rather than mounted directly on the bronchoscope 12 .
[0060] Although the clamp connector 60 may have various forms, the C-shaped form provides particular advantages. The C-shape provides direct access to the passageway 108 through the first end 102 while it is connected to the bronchoscope 12 . When the stent delivery catheter or other instrument is passed through the passageway 108 , the physician or user can easily grasp the catheter near the first end 102 to assist in advancing the catheter through the bronchoscope 12 . This may reduce any risk of kinking the catheter and may assist is passing the catheter through seals within the bronchoscope and/or clamp connector. In addition, such direct access to the passageway 108 through the first end 102 allows the insertion of various instruments without passing the instruments through the second end 104 . For example, a syringe may be inserted through the first end 102 to directly inject drugs, etc., into the working lumen 18 of the bronchoscope 12 . Likewise suction can be drawn through the working lumen 18 and the first end 102 without drawing suction through the entire connector 60 .
[0061] FIGS. 8A-8B illustrate another embodiment of a clamp connector 60 . In this embodiment, the clamp connector 60 has the form of a bracket which attaches to the handle 24 of a bronchoscope 12 , as shown in FIG. 8A . An occlusal stent delivery catheter 40 may be advanced through the side arm 24 a of the bronchoscope handle 24 so that its distal end 42 passes through the bronchoscope 12 . The positioning rod 44 , which passes through the catheter 40 and extends from the its proximal end, may then be coupled with the clamp connector 60 to lock the positioning rod 44 in a fixed position in relation to the bronchoscope 12 . FIG. 8B illustrates the occlusal stent delivery catheter 40 of this embodiment showing the positioning rod 44 extending through the tubular shaft 41 . The occlusal stent 46 is shown disposed within the tubular shaft 41 near the distal end 42 . Thus, when the positioning rod 44 is locked to the connector 60 , the rod 44 is fixed in place. The tubular shaft 41 may then be retracted to expose and deploy the stent 46 . By fixing the positioning rod 44 in relation to the bronchoscope 12 , there is reduced variability in positioning the stent 46 thereby improving placement accuracy.
[0062] FIGS. 8C-8E illustrate another embodiment of a clamp connector 60 . In this embodiment, the clamp connector 60 includes an elongate holder 170 , a base 172 and a support 174 , as illustrated in FIG. 8C . The elongate holder 170 is comprised of a shaft 176 having a plate 178 (with an aperture 180 ) attached near one end, and its other end is configured to receive the support 174 . Referring to FIG. 8D , the elongate holder 170 is coupleable with a bronchoscope 12 . The plate 178 may be positioned against the bronchoscope 12 so that the side arm 24 a of the bronchoscope 12 passes through the aperture 180 . The base 172 is positioned against the bronchoscope 12 on a side opposite to the side arm 24 a so that the base 172 wraps around the bronchoscope 12 as shown. The plate 178 may then be attached to the base 172 with the use of screws 182 or any suitable device. This fixes the clamp connector 60 to the bronchoscope 12 . The embodiments described in FIGS. 8A-8D are exemplary and any bracket configuration which attaches to the bronchoscope can be used.
[0063] An occlusal stent delivery catheter 40 may then be advanced through the side arm 24 a and coupled with the clamp connector 60 to lock the positioning rod 44 in a fixed position in relation to the bronchoscope 12 . FIG. 8E provides a side view of the occlusal stent delivery catheter 40 positioned on the clamp connector 60 . The plate 178 may be connected with the shaft 176 at any suitable angle so that the shaft 176 holds the catheter 40 in a desired position while allowing manipulation of the bronchoscope 12 . The positioning rod 44 passing within the catheter 40 is locked in place by coupling the rod 44 with the support 174 . Thus, the rod 44 , clamp connector 60 and bronchoscope 12 are in fixed relation to each other. The tubular shaft 41 of the delivery catheter 40 may then be retracted to expose and deploy the stent 46 . Again, by fixing the positioning rod 44 in relation to the bronchoscope 12 , there is reduced variability in positioning the stent 46 thereby improving placement accuracy.
Occlusal Stent
[0064] The occlusal stent delivery system 10 may be used to deliver a variety of occlusal stents 46 . Occlusal stents 46 may also be referred to, for example, as occlusal devices, occlusive stents, obstructive devices or plugs. Exemplary occlusal stents 46 are provided in U.S. Pat. No. 6,527,761 [Attorney Docket No. 017534-001200US], and U.S. Provisional Patent Application No. 60/628,649 [Attorney Docket No. 017534-002000US], both assigned to the assignee of the present invention and incorporated by reference for all purposes. A number of embodiments of occlusal stents 46 are comprised of structural supports which expand to anchor the occlusal stent 46 in a lung passageway.
[0065] Referring now to FIG. 9 and FIG. 9A , an embodiment of an occlusal stent 46 is shown. Here, the occlusal stent 46 comprises a braid 400 . The braid 400 may be comprised of any type of wire, particularly superelastic and/or shape-memory wire, polymer or suitable material. In this embodiment, the braid 400 is comprised of 0.006″ Nitinol wire (30-45% CW, oxide/etched surface). The wire braid 400 can be woven from wires having the same diameter, e.g. 24 wires each having a 0.006″ diameter, or wires having varied diameters, e.g. 12 wires each having a 0.008″ diameter and 12 wires each having a 0.003″ diameter. Other numbers of wires and combinations of wire diameters can also be used.
[0066] The braid 400 is fabricated on a mandrel having a diameter close in size to the desired diameter of the occlusal stent 46 when unrestrained or in free space. The unrestrained diameter of the stent 46 is typically desired to slightly exceed the internal diameter of the bronchial tube within which it will be placed. Thus, the diameter of the braid 400 may vary depending on the intended usage of the stent 46 . Once the braid has been fabricated, the braid is then cut to an appropriate length and shape-set to a desired configuration by heat treatment. The desired configuration generally comprises the ends of the cut length of braid collapsed to form ends or tails, which will be secured and covered by bushings 401 , and a portion therebetween having an overall shape conducive to occluding a lung passageway. When other materials, such as Elgiloy.RTM. and stainless steel, are used, the wire is formed into the desired configuration using methods different from shape setting methods used for shape memory alloys. After shape-setting, the braid may then be etched to remove oxidation and to form a new passivation layer.
[0067] The desired configuration may include a variety of overall shapes, each allowing the occlusal device 46 to perform differently or occlude lung passageways of differing shapes, sizes and configurations. FIG. 9 is a side view of one embodiment of the stent 46 having shoulders 402 which are at an angle which is approximately 90 degrees to a longitudinal axis 404 of the stent 46 . Shoulders 402 at such an angle allow maximum contact surface area in relation to length of the stent 46 . This is useful when placing the stent 46 into short bronchial segments or take-offs. FIG. 9A is an end view of the embodiment shown in FIG. 9 .
[0068] Typically, the braid 400 is connected to, encapsulated in, coated or impregnated with a material to prevent flow of gases or liquids through the occlusal device 46 , thereby providing an obstruction. In addition, the material may optionally include an antibiotic agent for release into the lung passageway. Examples of obstructive materials include a thin polymer film 120 at least partially encapsulating the occlusal device 46 , which may be used to seal against the surface of the lung passageway. Such a design is depicted in FIG. 9 . As shown, the film 120 does not completely encapsulate the device 46 , leaving a portion of the shoulders 402 exposed. This allows for air to escape from the device 46 when the device is collapsed or contracted. In some embodiments, a bushing 401 located near the exposed area is color coded to signify the area so that the device 46 is loaded in the desired orientation within the delivery catheter 40 .
Occlusal Stent Loading
[0069] One or more occlusal stents 46 may be loaded within the delivery system 10 for delivery within a lung passageway. In preferred embodiments, the occlusal stent(s) are loaded into the delivery system 10 with the use of an occlusal stent loading system 130 . An embodiment of a loading system 130 of the present invention is illustrated in FIG. 10A . As shown, the system 130 includes a loading body 134 , a loading mandrel 136 , and a lubricious liner 132 . The loading body 134 has a wide-mouthed end 138 and narrow-mouthed end 140 , wherein the occlusal stent 46 is loadable into the wide-mouthed end 138 in an expanded configuration and removed from the narrow-mouthed end 140 in a contracted configuration. Thus, the loading body 134 contracts the occlusal stent 46 for loading into the delivery catheter 40 . The loading body 134 is also used to load the contracted stent 46 into the delivery catheter 40 .
[0070] The occlusal stent 46 can be loaded into the loading body 134 with the use of the loading mandrel 136 . The mandrel 136 includes a proximal end 141 , a distal end 142 and a shaft 143 therebetween. An attachment device 144 is disposed near the distal end 142 which is used to removably attach to the occlusal stent 46 . The attachment device 144 may be integral with the mandrel 136 or mounted on, attached to, coupled with the mandrel 136 , for example. The attachment device 144 may have any suitable form, including a hook, fork, clasp, fastener, or magnet, to name a few. The mandrel 136 may also include a mandrel grip 146 which has an inner lumen 148 sized for passage of the mandrel 136 therethrough so that the grip 146 may be positioned at any location along the length of the shaft 142 . In some embodiments, the grip 146 also serves as a depth stop when loading the stent 46 within the loading body 134 . In these embodiments, the grip 146 is preferably positioned in the range of approximately 34 to 38 mm from the proximal end 141 of the shaft 143 . The use of the grip 146 as a depth stop will be further described in later sections. In addition, the mandrel 136 may also include one or more mandrel end covers 149 .
[0071] The shaft 143 is sized to be passed through loading body 134 . FIG. 10B provides a top view of the loading body 134 having the mandrel 136 positioned therein. As shown, the body 134 includes a loading receptacle 150 , a restrictor 152 and a holding tube 154 . The lubricious liner 132 is shown inserted into the wide-mouthed end 138 and positioned so that the liner 132 extends through the restrictor 152 and holding tube 154 . FIGS. 11A-11D illustrate how an occlusal stent 46 may be prepared for loading into the catheter 40 with the use of these elements of the loading body 134 .
[0072] FIG. 11A illustrates a portion of the loading body 134 wherein the distal end 142 of the loading mandrel 136 is shown passed through the narrow-mouthed end 140 to and beyond the wide-mouthed end 138 . The attachment device 144 is shown attached to the occlusal stent 46 . In this embodiment, the attachment device 144 comprises a fork which releasably joins with the occlusal stent 46 . The mandrel 136 is then retracted, drawing the occlusal stent 46 into the loading receptacle 150 at the wide-mouthed end 138 , as shown in FIG. 11B . Further retraction of the mandrel 136 pulls the occlusal stent 46 into the restrictor 152 which gradually collapses the stent 46 , as shown in FIG. 11C . As the stent 46 collapses, air within the stent 46 is forced out toward the narrow-mouthed end 140 . Still further retraction of the mandrel 136 pulls the contracted stent 46 into the holding tube 154 , as shown in FIG. 11D . The liner 132 serves to reduce any friction between the stent 46 and the loading body 134 as the stent 46 is collapsed and passed through the loading body 134 . Thus, the liner 132 may be comprised of any suitable material which reduces friction, such as Teflon.RTM. It may be appreciated that the liner 132 may alternatively be integral with the loading body 134 or may have the form of a coating on surfaces of the loading body 134 . The occlusal stent 46 is now ready for loading into the delivery catheter 40 .
[0073] It may be appreciated that the loading system 130 may be constructed from any suitable materials. Preferably, the loading body 134 is constructed from a material which allows visibility of the stent 46 throughout the loading process. This may ensure that the stent 46 is properly loaded within the loading body 134 . Alternatively or in addition, a variety of markings 82 , 82 ′ may be used to ensure proper loading. For example, as shown in FIG. 10A , the mandrel 136 may include a marking 82 , such as a line of ink, on the shaft 143 a desired distance from the distal end 142 . In preferred embodiments, the marking 82 is disposed approximately 0.3 inches from the distal end 142 . The loading body 134 then includes a corresponding marking 82 ′ near the narrow-mouthed end 140 , approximately 0.35 inches from the holding tube 154 . When the mandrel 136 is retracted so that the marking 82 on the shaft 143 is aligned with the marking 82 ′ on the loading body 134 , the occlusal stent 46 is properly positioned within the holding tube 154 .
[0074] The occlusal stent 46 may then be transferred to the delivery catheter 40 , as illustrated in FIGS. 11E-11G . FIG. 11E illustrates the delivery catheter 40 positioned against the holding tube 154 of the loading body 134 . The loading mandrel 136 or any other suitable instrument is used to transfer the occlusal stent 46 to the distal end 42 of the delivery catheter 40 . As shown, the proximal end 141 of the loading mandrel 136 is advanced through the loading receptacle 150 and the restrictor 152 until it contacts the occlusal stent 46 . Continued advancement of the loading mandrel 136 pushes the occlusal stent 46 from the holding tube 154 and into the catheter 40 . FIG. 11F illustrates the loading mandrel 136 fully advanced so that the occlusal stent 46 is fully loaded within the catheter 40 . In some embodiments, the mandrel grip 146 assists in proper placement of the stent 46 within the holding tube 154 by serving as a depth stop for the loading mandrel 136 . The grip 146 is sized so that it may be advanced into the loading receptacle 150 but cannot be advanced into the restrictor 152 , thus serving as a depth stop. The grip is positioned along the length of the mandrel 136 so that when the grip 146 is positioned against the restrictor 152 , as shown in FIG. 11F , the stent 46 is properly positioned within the holding tube 154 . FIG. 11G illustrates the distal end 42 of the catheter 40 removed from the loading body 134 and having the occlusal stent 46 loaded inside.
[0075] It may be appreciated that the loading system 130 may be adapted to load more than one occlusal stent 46 . For example, the holding tube 154 may be lengthened to hold two, three, four, five or more stents 46 at one time. The stents 46 may be individually loaded into separate delivery catheters, simultaneously loaded into a single delivery catheter or loaded in groups into a few catheters.
[0076] FIGS. 12A-12C illustrate an alternative method of loading a delivery catheter 40 with an occlusal stent 46 . In this embodiment, one or more stents are loaded directly into the distal end 42 of the delivery catheter 40 . As shown in FIG. 12A , the delivery catheter 40 includes a positioning rod 44 having a grasping device 160 disposed at its tip. In this example, the grasping device 160 has the shape of a ring, loop, hoop or circle. The device 160 may be comprised of any suitable material, such as wire, polymer, thread, fiber, or suture, to name a few. A restricting insert 162 is positioned at least partially within the distal end 42 , such as shown. Optionally it can be appreciated that the restricting insert 162 can be of the type that engages with an outer surface or edge of the distal end 42 so that the insert 162 is not at least partially within the distal end 42 . The restricting insert 162 is used to assist in collapsing and loading the stent 46 within the distal end 42 of the catheter 40 . This is achieved by retracting the tubular shaft 41 so that the grasping device 160 can be removably attached to a bushing 401 on an occlusal stent 46 . As shown in FIG. 12A , at least one of the bushings 401 includes a notch 164 which is mateable with the grasping device 160 . As shown in FIG. 12B , the grasping device 160 attaches to the bushing 401 and draws the occlusal stent 46 through the restricting insert 162 and into the tubular shaft 41 of the catheter 40 . FIG. 12C shows the distal end 42 of the catheter 40 having the occlusal stent 46 loaded inside and the restricting insert 162 removed.
[0077] FIGS. 13A-13C illustrate an similar method of loading a delivery catheter 40 with an occlusal stent 46 . As shown in FIG. 13A , the delivery catheter 40 includes a positioning rod 44 having a grasping device 160 disposed at its tip. In this example, the grasping device 160 has the shape of a pincher or claw. The tubular shaft 41 is retracted so that the grasping device 160 pinch onto a bushing 401 on an occlusal stent 46 . As shown in FIG. 13A , at least one of the bushings 401 includes one or more protrusions 166 which the grasping device 160 is able to utilize in grasping. As shown in FIG. 13B , the grasping device 160 grasps the bushing 401 and draws the occlusal stent 46 through the restricting insert 162 and into the tubular shaft 41 of the catheter 40 . A restricting insert 162 is positioned at least partially within the distal end 42 , as shown. The restricting insert 162 is used to assist in collapsing the stent 46 and loading the stent 46 within the distal end 42 of the catheter 40 . The grasping device 160 may also be used to retrieve or adjust an occlusal stent 46 which has been deployed in a lung passageway LP, as illustrated in FIG. 13C . As shown, the distal end 42 of the catheter 40 may be retracted to expose the grasping device 160 which can be used to grasp onto the bushing 401 of the occlusal stent 46 . The stent 46 may then be manipulated by the grasping device 160 . In some methods, the occlusal stent 46 may be deployed in a more distal position within the lung passageway LP than desired so that the stent 46 may then be pulled proximally to a desired position with the use of the grasping device 160 .
[0078] It may further be appreciated that delivery catheters 40 of the present invention may alternatively be provided to a physician or user in a preloaded state wherein one or more occlusal stents 46 are provided within the catheters 40 , ready for delivery. Further, it may be appreciated that automatic loading systems may be provided, or systems in which the stent is pre-connected to the catheter rod but not yet loaded into the catheter receptacle.
Methods of Use
[0079] The occlusal stent delivery system 10 of the present invention may be used for a variety of therapeutic procedures, preferably for performing “endobronchial volume reduction” (EVR). EVR is a non-surgical technique for isolating and occluding diseased lobar and sub-lobar regions of a patient's lung. An isolated region will be a portion (usually not the whole) of the right or left lung, and volume reduction will be accomplished by evacuating the region and occluding a bronchial passage within or leading to the region with an occlusal stent 46 . One or more bronchial passageways within or leading to the region may be occluded while the region is evacuated, as will be described.
[0080] Initially, the bronchoscope 12 is separate from the sheath 30 and the distal end 16 of the scope 12 is then introduced through a luer or other proximal connector 34 of the sheath 30 . Referring back to FIG. 1 , the distal end 16 is advanced until the occlusive member 32 is disposed at a desired position along the length of the scope 12 . At that point, the luer or other connector 34 is then tightened on to the scope 12 . A suitable monitor may then be connected to the bronchoscope 12 in a conventional manner. Inflation of member 32 may be effected through an inflation tube 36 , typically using a pressurized air or other gas source.
[0081] Referring now to FIG. 14A , the assembly of the sheath 30 and bronchoscope 12 may be introduced through the trachea T to a target location in a patient's lung LNG. The sheath-bronchoscope assembly 30 / 12 is introduced so that the occlusive member 32 reaches a desired location, in this example a major takeoff in the left lung. At that point, the member 32 may be inflated. During the advancement and after inflation of the member 32 , viewing through the bronchoscope 12 may be accomplished through the monitor connected to the scope 12 .
[0082] While the member 32 is inflated, lung segments beyond the member 32 may be evacuated by applying vacuum suction through an aspiration lumen 22 in the bronchoscope 12 . The occlusal stent delivery catheter 40 (having an occlusal stent 46 pre-loaded within its distal end 42 ) is then advanced through the working lumen 18 of the bronchoscope 12 . Forward imaging by the bronchoscope 12 is effected by illuminating through light fibers within the scope lumen 20 and detecting an image through a lens at the distal end 16 of the bronchoscope 12 . The resulting image can be displayed on conventional cathode-ray or other types of imaging screens. In particular, forward imaging permits a user to selectively place the catheter 40 through a desired route through the branching bronchus. It may be appreciated, however, that as an alternative positioning could be done solely by fluoroscopy.
[0083] In any case, referring again to FIG. 14A , the delivery catheter 40 is then advanced until its distal end 42 reaches a region in the bronchus or lung passageway which leads directly into a diseased region DR. The delivery catheter 40 is advanced through the working lumen 18 of the bronchoscope 12 via the passageway 108 of the clamp connector 60 attached to the side arm 24 a , as previously described. Once the distal end 42 of the catheter 40 is positioned in a desired location within the lung passageway, the catheter 40 is locked in place with the use of the locking mechanism 64 on the clamp connector 60 . The occlusal stent 46 may then be deployed in the passageway. Recall, the occlusal stent 46 is pre-loaded in a compressed or collapsed state within an interior lumen of the delivery catheter 40 . The occlusal stent 46 is deployed by retracting the tubular shaft 41 of the delivery catheter 40 . This is achieved by sliding the handle button 50 on the handle 48 of the catheter 40 , as previously described. As the tubular shaft 41 retracts, the positioning rod 44 holds the occlusal stent 46 in place. Thus, the occlusal stent 46 is gradually exposed. If the stent 46 is self-expanding, for example by tension or shape-memory, the stent 46 will expand and anchor itself in the passageway as the occlusal stent 46 is exposed, as shown in FIG. 14A . If the occlusal stent 46 is not self-expanding, it may be expanded with the use of a balloon or other mechanism provided by the delivery catheter 40 , a catheter or device delivered through the catheter 40 , or another device.
[0084] While the sheath 30 and occlusive member 32 are in place, additional occlusal stents may be positioned within the evacuated lung passageways beyond the member 32 . The delivery catheter 40 may be removed and loaded with a second occlusal stent 46 ′ for reintroduction, or the delivery catheter 40 may be removed and replaced with another delivery catheter 40 that has already been preloaded with a second occlusal stent 46 ′. Referring now to FIG. 14B , the delivery catheter 40 is then advanced until its distal end 42 reaches a region in the bronchus or lung passageway which leads directly into a second diseased region DR′. Again, the delivery catheter 40 is advanced through the working lumen 18 of the bronchoscope 12 with the use of the clamp connector 60 attached to the side arm 24 a , as previously described. Once the distal end 42 of the catheter 40 is positioned in a desired location within the lung passageway, the catheter 40 is locked in place with the use of the locking mechanism 64 on the clamp connector 60 . The second occlusal stent 46 ′ may then be deployed in the passageway. The second occlusal stent 46 ′ is deployed by retracting the tubular shaft 41 of the delivery catheter 40 . As the tubular shaft 41 retracts, the positioning rod 44 holds the second occlusal stent 46 ′ in place. If the stent 46 ′ is self-expanding, the stent 46 ′ will expand and anchor itself in the passageway as the second occlusal stent 46 ′ is exposed, as shown in FIG. 14B .
[0085] Further, while the sheath 30 and occlusive member 32 are in place, any number of additional occlusal stents may also be positioned within the evacuated lung passageways beyond the member 32 . Again, the delivery catheter 40 may be removed and loaded with a third occlusal stent 46 ″ for reintroduction, or the delivery catheter 40 may be removed and replaced with another delivery catheter 40 that has already been preloaded with a third occlusal stent 46 ″ (thus, it may be efficient to utilize two delivery catheters 40 so that one catheter 40 may be preloaded with an occlusal stent while the other is in use). The delivery catheter 40 is then advanced until its distal end 42 reaches a region in the bronchus or lung passageway which leads directly into a third diseased region DR″. Again, the delivery catheter 40 is advanced through the working lumen 18 of the bronchoscope 12 with the use of the clamp connector 60 attached to the side arm 24 a , as previously described. Once the distal end 42 of the catheter 40 is positioned in a desired location within the lung passageway, the catheter 40 is locked in place with the use of the locking mechanism 64 on the clamp connector 60 . The third occlusal stent 46 ″ may then be deployed in the passageway, as shown in FIG. 14C .
[0086] The occlusive member 32 may then be deflated and the delivery system 10 removed, leaving the occlusal devices 46 , 46 ′, 46 ″ behind wherein each occlusal device isolates and occludes a diseased region DR, DR′, DR″, respectively.
[0087] Although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that various alternatives, modifications and equivalents may be used and the above description should not be taken as limiting in scope of the invention which is defined by the appended claims. | Methods, systems and devices are provided for performing lung volume reduction in patients suffering from chronic obstructive pulmonary disease or other conditions where isolation of a lung segment or reduction of lung volume is desired. The methods are minimally invasive with instruments being introduced through the mouth (endotracheally) and rely on isolating the target lung tissue segment from other regions of the lung and occluding various lung passageways with the use of occlusal stents. The occlusal stents are delivered with the use of an occlusal stent delivery system which is loaded with the occlusal stent with the use of an occlusal stent loading system. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a checker-like iron wire mesh fence structure which can be assembled without limitation of tolerance and can be quickly installed without requiring any special technique.
It is known that some leisure sites such as swimming pools, tennis courts, baseball fields, etc. are surrounded by walls or iron wire meshes in order to control the access to these sites and facilitate the management. Such iron wire meshes are manufactured and installed in two ways as follows: 1. assembling type; and 2. welding type. Several shortcomings exist in such ways as follows:
1. Assembling type: The supporting posts are fixed by concrete. The interval between the posts and the inclination of the posts cannot be accurately controlled. Therefore, it often takes place that after the concrete is solidified, two adjacent posts are respectively inclined leftward and rightward. This results in the upper transverse beam and the lower transverse beam between the fixed posts being unequal to each other. Accordingly, the iron wire meshes can not be quickly installed.
2. Welding type: The transverse beam is welded to the fixed posts and the iron wire meshes are point-welded on the transverse beam and the posts into intersected checker-like iron wire meshes. Although the working speed is faster than that of the assembling type, because the material of the iron wire mesh is damaged due to the welding operation, the welded portions are subject to rusting and breakage. Therefore, the useful life of the product is shortened.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a checker-like iron wire mesh fence structure in which the supporting posts and the upper and lower transverse beams are assembled with each other by hooking seats to achieve the following advantages:
1. The upper and lower transverse beams are engaged with hooking seats, whereby when installed, a thread rod is directly passed through the hooking seats to quickly secure the upper and lower transverse beams on the supporting posts.
2. It is unnecessary to cut off the upper and lower transverse beams due to the separation of the supporting posts. Therefore, when installed, the transverse beams can be extensively adjoined without limitation and it is possible to mass-produce the transverse beams.
3. The hooking seat is made directly by punching and bending so that it is quite easy to manufacture the hooking seat which has light weight and can be used more conveniently.
4. The parts of the hooking seat can be easily replaced so that the working time for processing is reduced and it is possible to mass-produce the hooking seat at low cost.
5. The assembly of the iron wire mesh fence can be easily completed without requiring any special technique.
The present invention can be best understood through the following description and accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective exploded view of the present invention;
FIG. 2 is a side sectional view of the present invention;
FIG. 3 is a front view of the present invention;
FIG. 4 is a perspective exploded view of another embodiment of the present invention; and
FIG. 5 is a perspective assembled view of the embodiment according to FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Please refer to FIGS. 1 to 5. The checker-like iron wire mesh fence structure of the present invention consists of concrete 1, a plurality of supporting posts 2 set in concrete 1, an upper transverse angle beam 3, a lower transverse angle beam 4, an iron wire mesh 30, a plurality of hooking seats 5, a plurality of threaded rods 6, a plurality of nuts 7 and a plurality of washers 8.
The supporting post 2 has a U-shaped cross-section, Two lateral wall faces of the upper and lower ends of the supporting post 2 are punched to form oppositely directed upper and lower reverse hooks 22.
The upper and lower transverse angle beams 3, 4 have oppositely oriented angle legs punched to form multiple equally spaced and oppositely directed hanging hooks 31, 41 on the same side, whereby the upper and lower sides of the iron wire mesh can be hooked on the hanging hooks 31, 41.
The hooking seat 5 is made from a steel sheet by punching the same into a T-shaped member, two sides of which are equally bent toward each other to form the hooking seat 5 with a double L-shaped cross-section having an engagement opening in the form of a notch 52. The equal sides of the hooking seat 5 are parallel to adjoined with each other by a bight section 53.
According to the above arrangement, the supporting posts 2 are fixed by the concrete 1 at equal intervals. The upper and lower transverse beams 3, 4 are respectively disposed in the notches 52 of the hooking seats 5. The threaded rod 6 is passed through the thread hole 21 of the supporting post 2 and the bight section 53 of the hooking seat 5. Then the washer 8 is fitted around the threaded rod 6 and the nut 6 is fastened on the threaded rod 6 to retain the upper transverse beam 3 in the reverse hooks 22 and secured on the supporting posts 2. The lower transverse beam 4 is similarly secured on the supporting posts 2 by means of the reversely directed hooking seat 5 and the threaded rod 6 and nut 7. Then the iron wire mesh 30 is hung on the hanging hooks 31, 41 of the upper and lower transverse beams 3, 4 to form the checker-like iron wire mesh as shown in FIG. 3.
FIG. 4 shows another embodiment of Q hooking seat 9 which is punched into a substantially T-shaped member and oppositely bent into a hook-like member having an arrangement opening in the form of an insertion slot 91 for hanging the upper and lower transverse beams 3, 4 thereon. In addition, a bight section 92 of the hooking seat 9 defines a space for the thread rod 6 to pass therethrough.
After the supporting posts 2 are fixed, the upper and lower transverse beams 3, 4 are respectively directly placed into the reverse hooks 22 of the supporting posts 2. Then the insertion slots 91 of the hooking seats 9 are placed on the horizontal sections 32, 42 of the upper and lower transverse beams 3, 4. Then the iron wire mesh 30 is hung on the hanging hooks 31, 41 thereof to complete the assembly of the checker-like iron wire mesh structure.
The above embodiments are only examples of the present invention and the scope of the present invention should not be limited to the examples. Any modifications or variations derived from the examples should fall within the scope of the present invention. | A wire mesh fence is formed by securing a plurality of spaced posts in concrete, each post being provided with upper and lower oppositely directed reverse hooks and hooking seats for engaging and supporting a pair of angle beams having a plurality of oppositely directed hanging hooks for securing a wire mesh between the beams. | 4 |
FIELD OF THE INVENTION
This invention relates in general to a charge intake system for a fuel injected automotive type engine. More particularly, it relates to one having more than one intake valve per cylinder, and a deactivation or charge flow blocking valve for selectively controlling flow into the intake ports.
BACKGROUND OF THE INVENTION
It is well known that engines designed with two intake valves per cylinder are capable of producing high horsepower levels. This capability is maximized when both ports receive an equal amount of fuel. A single injector spraying into both tracks or runs of a siamesed intake manifolding arrangement, such as shown in FIG. 1A, can economically provide for this fueling requirement.
Stringent NOx emission control requirements can be met without fuel efficiency loss if the burn rate in the engine is sustained at an optimal level while introducing high rates of charge diluting EGR to suppress knocking. Desired control of burn rate can be achieved by blocking most or all of the air flow to one of the ports. If a flow deactivator or control valve is installed into the siamesed port arrangement shown, for example, in FIGS. 1B and 1C upstream of the injector, the burn rate improvement is inadequate because the siamesing connection still allows sufficient air to cross over into and bypass the supposedly deactivated port. Good burn rate control has been achieved with separated ports, one of them being deactivated, such as is shown in FIG. 1D, with fuel being injected into the active port. However, the drawback to this arrangement is that when both ports are open, only half of the air is impregnated with fuel. This leads to some power and fuel economy losses.
If a port deactivator or control valve is applied to a siamesed port layout downstream of the siamesed section, again FIG. 1A, the active port induces high swirl rate into the cylinder; however, some concern might be had about fuel being injected to both the active and the inactive port. Experimental results with separate ports, one of them being deactivated, however, indicate that half of the fuel can continue to be injected into the inactive port without detrimental effects. The reasons for this are:
1. Backflow during overlap between the exhaust and intake cycles, and a slight leakage through the deactivated valve will carry the fuel into the cylinder.
2. Swirl induced by the biasing of the air flow into one passage is so beneficial for mixing and burn rate that the possible detrimental effect of fuel stratification is completely eliminated.
It follows from the above that there can be two alternative resolutions that could achieve optimal results.
1. Twin porting with a very small siamesed section, adequate only for the installation of a unique injector having two spray holes about 8-10 mm apart so that fuel is introduced to both ports from one injector. The port deactivation valve would be upstream of the injector.
2. Conventional siamesed porting with a deactivation valve downstream of the siamesed, section, such as is illustrated in FIG. 1A.
This invention is directed to the use of a one-piece deactivation or control valve that can be installed into the cylinder head intersecting all of the multiple intake valve passages and situated close to the intake ports, thereby facilitating the use of conventional siamesed porting and fueling, such as is shown in FIG. 1A.
Takii et al. U.S. Pat. No. 4,766,866 shows a charge intake system similar to that shown herein in FIG. 1C. More particularly, it shows a cylinder with three intake valves 24, 25, 26 receiving a charge from a passage 31, with individual runners or logs 37 and 38 upstream of a fuel injector 32. One of each pair of the logs can be controlled by a butterfly type valve 41, 42, the valves being mounted on a common shaft 43. It should be noted that the valves in this case are upstream of the fuel injector and also outside of the cylinder head, and require separate mounting of the valve, per se, to a shaft, in contrast to the construction to be described.
Aoyama et al. U.S. Pat. No. 4,703,734 shows a charge intake system having two intake valves per cylinder connected by separated passages to a common intake passage leading into the cylinder head. In this case, a fuel injection valve 30 is mounted in one passage and a deactivation or flow control valve 8 is mounted in the other passage, in a manner similar to that shown in FIG. 1D herein. The butterfly type valves are fixed to a common shaft. Here again, as in FIG. 1D herein, only half of the air is impregnated with fuel when both ports are open.
Aoyama et al. U.S. Pat. No. 4,628,880 is another example of an engine having two intake valves per cylinder with separated intake passages, one containing a deactivation or control valve, and the other the fuel injection valve. The disadvantages of this construction are as described above in connection with U.S. Pat. No. 4,703,734.
Yagi et al. U.S. Pat. No. 4,317,438 and Motosugi et al. U.S. Pat. No. 4,240,387 are examples of engines with one or more intake valves and deactivation or control valves regulating the charge flow into the cylinders. However, in each case, there is no fuel injection valve and the mixture is supplied by a carburetor. Furthermore, in each case, the multiple control valves appear to be individually attached to a single shaft outside of the cylinder head.
Sugiyama U.S. Pat. No(s). 4,512,311 and 4,576,131, both show a multi-intake valve per cylinder engine having a common intake runner and separated siamesed passages to the intake ports. FIG. 4 shows one of the passages being controlled by a deactivation or control valve to regulate the flow from a fuel injector mounted upstream of both passages. It will be noted, however, that the individual deactivation or control valves appear to be individually attached to a common shaft; and that the shaft is mounted outside of the cylinder head and therefore not close to the intake ports, and is not of a simplified construction, such as is to be described hereinafter. The outside mounting increases the length of the divided passages and, therefore, eliminates the use of conventional siamesed passages.
Walchle et al. U.S. Pat. No. 3,750,698 is cited merely as an illustration of a valve having a polytetrafluoroethylene coating for reducing friction.
SUMMARY OF THE INVENTION
As stated previously, the invention is directed to the use of a one-piece deactivation or control valve that is installed within the cylinder head close to the intake ports so that conventional siamesed porting constructions can be used. This simplifies the construction and provides for an economical assembly. As will be described, the deactivation or control valve in this case is a die casting of aluminum around a central steel rod and contains the end disks for sealing between the flow passages. Integral with it are individual flat plate valves or a valve for selectively controlling the charge flow into the various intake ports. The valve in this case is inserted by sliding into a bore of constant diameter provided in the cylinder head.
Therefore, it is a primary object of the invention to provide a charge intake system for a multi-intake valve per cylinder engine that includes a port deactivation or control valve of a unique construction that simplifies the assembly and reduces the cost of manufacture, and yet provides finite control of the charge flow into the engine.
Another object of the invention is to provide a deactivation or control valve of the type described above that consists of a simple barrel type, paddle-like valve slidably insertable into a constant diameter bore directly into the cylinder head per se, to permit the use of conventional siamesed passage manifolding connected to the cylinder head.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the invention will become more apparent upon reference to the succeeding, detailed description thereof, and to the drawings illustrating the preferred embodiment thereof; wherein:
FIGS. 1A, 1B, 1C and 1D are schematic illustrations of various type engine charge intake systems for conveying air and fuel to a multiple intake port engine;
FIG. 2 is an enlarged cross-sectional view of a portion of the cylinder head of an engine embodying the invention;
FIG. 3 is an enlarged cross-sectional view taken on a plane indicated by and viewed in the direction of the arrows III--III of FIG. 2;
FIG. 4 is a cross-sectional view similar to that of FIG. 3, but showing the valve located out of the position shown in FIG. 3 for illustrating other details of the invention; and
FIGS. 4A, 4B, 4C and 4D are cross-sectional views taken on planes indicated by and viewed in the direction of the arrows 4A--4A, 4B--4B, 4C--4C and 4D--4D of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1A, 1B, 1C and 1D have already been described above in connection with a discussion of the prior art. However, briefly, FIG. 1A shows an engine intake manifolding consisting of a single intake passage, or runner, or log, 10, that is bifurcated or divided at its lower portion to provide two siamesed passages 12 and 14. A fuel injection valve 16 is located at the point of bifurcation upstream of the two passages. The separated passages 12 and 14 lead to individual intake ports 18 and 20 located in the cylinder head.
FIG. 1B shows a construction in which the single intake log or runner 10 is divided at 22 into two branch passages 24 and 26, passage 24 containing a deactivation or flow control valve 28. Downstream, the passages recombine momentarily past a fuel injection valve 30 before being subdivided again into a pair of siamesed passages 32 and 34.
FIG. 1C shows a construction similar to FIG. 1B except that the primary air intake is provided by separate intake passages 36 and 38. Otherwise, the construction is the same as that described in connection with FIG. 1B.
FIG. 1D shows a single runner or log 40 subdivided into separate intake passages 42 and 44 for separate connection into the intake ports 46 and 48. A fuel injector 50 is installed in the one passage 44 while a deactivation or control valve 52 is installed in the other passage 42.
FIG. 2 shows more specifically the construction of a cylinder head and adjoining parts embodying the invention. A cylinder head 60, in this case, encloses a valve train of the overhead cam type, as indicated by the camshaft 62 having a cam 64 secured thereto. A roller finger follower type rocker arm 66, having a fulcrum 68, engages the cam 64 at one end and the stem 70 of an intake valve 72 at its opposite end. Valve 72 is reciprocably movable into or out of a non-circular (see FIG. 3) intake port 18, commonly provided in the cylinder head. The intake port is connected by a non-circular passage 12 to the outside face of the cylinder head indicated schematically at 78.
In the passage 12, closely adjacent the port 18, is provided a constant diameter bore 80 drilled straight through the cylinder head longitudinally and transverse to passages 12 and 14. It is vertically aligned insofar as the cylinder head is concerned with the top portion of the head just outside where the cylinder head bolts normally are provided, but not shown in this particular installation. The head bolts, four of them to each cylinder, usually straddle the cylinder as close to the cylinder as manufacturing will permit. This leaves a space between the head bolts and the outer face of the cylinder head, especially in the case of the angled intake valves and intake ports shown. This space otherwise is not used, but in this particular case, is used to incorporate the deactivation or control valve in the bore 80.
More particularly, as stated, a cylindrical hole 80 is machined through the cylinder head lengthwise, just outside of the head bolts, as described. The hole intersects all of the intake passages, as shown more clearly in FIG. 3, the passage cross-sections being indicated by dotted lines 12, 14. The diameter of hole 80 is slightly larger than the height of the passages 12, 14. The two intake passages of each cylinder at the hole centerline are separated; however, as indicated in FIG. 1A, they are joined, or siamesed, upstream of this point, in this case at a distance somewhat more than half of the diameter of hole 80.
FIG. 3 shows the one-piece barrel valve 82 that is inserted in the hole 80. The valve is constructed by die casting of aluminum around a central steel rod 84. This method provides for adequate rotational strength, as well as a degree of lateral flexibility desirable to prevent binding due to thermal or other distortions of the bore 80. The valve consists of the central steel rod 84 to which are die cast a number of annular disks 86, 88, 90. The disks are axially separated the width of the intake passages 12 and 14 in FIG. 1A for sealing communication between the passages and the cylinder head outside areas. Section 4A shows that the barrel valve at the passage 12, to be deactivated or controlled or blocked, has a cross-section, 92, resembling a rectangular throttle plate. Passage deactivation, or blocking, is achieved by the rotation of the barrel valve and throttle plate about 90°. In the open position shown in FIG. 2, the plate aligns with the flow direction and allows air and fuel passage. In the closed position, the valve blocks a very large fraction of the passage cross-section, thereby deactivating or blocking this passage.
Referring to FIG. 1A, considering that fuel is being injected into both ports 18 and 20, the throttle plate is constructed of a height slightly less than the full diameter of bore 80 such that a leakage path is provided both at the top and bottom of the valve in cross-section 4A. This path will assure the ingestion into the cylinder of the fuel that is injected towards the closed, or deactivated, passage 12. In passage 14 leading to intake port 20, and indicated in FIG. 4C, is a small diameter cylindrical section 94, as shown in FIG. 4C, that can prevail across the entire width of the passage 14, if desired. This part of the flow path would be unaffected by the rotation of the valves 92. Alternatively, the primary passage 14 flow area can be reduced, if desired, as shown by the partial deactivation valve 96, indicated in Section 4B. The partial blocking of the flow area in port 20 will increase the air velocity and the swirl rate in the cylinder. The width of the partial deactivation valve 96 in passage 14 will also control the maximum swirl rate. Gradual reduction of swirl can be achieved by the gradual opening of the valve. Therefore, it will be seen from the above construction that at least one passage 12 can be essentially blocked, with small leakage around the top and bottom of the valve, to control the air flow and fuel flow into the engine. Also, the primary passage 14 can be entirely open or partially blocked by the use of a partial deactivation plate 96, as shown.
The design of the barrel valve 82 is such that special features are provided that will cope with deposit build-up in the intake ports. For example, the outside diameter of the barrel valve is machined to the full diameter at the disk sections 86, 88, and 90 to provide for guidance in the bore 80 as the valve is rotated. These disk sections are a constant width and uninterrupted around their circumferences, thereby disallowing deposit build-up that otherwise might hinder valve rotation. The throttle plate portions 92 and 96 of the valve are machined or cast about 2 mm smaller than a nominal full diameter. This feature provides for the leakage path, as described, and shown in FIG. 4A, and allows a degree of deposit build-up without blocking the movement of the valve. The entire valve may be coated to reduce friction and deposit adhesion. The coating could be a material such as polytetrafluorethylene or other materials known to those skilled in the art and suggested by this disclosure.
Experience has shown that the air and fuel dynamics limit the deposit build-up in the ports, and the thicker the deposit, the softer the deposit is. Therefore, with the clearance provisions as described, the valve will remain operable throughout the life of the engine.
As described previously, the construction of the barrel deactivation valve is by die casting. The lateral flexibility described can be obtained by the use of small cross-sectional reinforcement bars 78 that can be cast between the disks during machining to provide stiffness. Subsequent to finished machining, the bars can be removed by cutting or by impact. These are shown in FIG. 4D. They could also be applied in FIGS. 4A and 4B, if desired.
In summary, the advantage of the barrel valve is that it combines the burn rate control feature of separated passages with the power and high-speed fuel efficiency characteristics of the conventional siamesed passages. The manufacture of the system should be simpler than that of the conventional deactivation valve that consists of many components with a complicated assembly process.
The disadvantages of conventional deactivation or shut-off valves have been pointed out beforehand. Additionally, in a V8 engine installation, for example, most modern-day, 4-valve per cylinder heads have valves at angled positions to the cylinder bore instead of vertical. Any attempt to use a conventional butterfly valve in the cylinder head would require that each intake passage be machined individually in a cylindrical fashion to assure accommodation of the circular butterfly valve. Also, there would be a need for individual attachment of each butterfly plate to its own shaft, connection of all of the shafts to each other and to some sort of bellcrank linkage, machining a vertical hole for the shaft from underneath the head because the valve train occupies the space on top, and making sure the shaft and linkage do not extend into an oil space, which would leak oil into the intake port passage. In a V8 engine, with the intake manifolding in the valley between banks of cylinders, the shaft would need to be installed from underneath the head, but in this type of engine, it is not easily accessible, and assembly of the shut-off valve, together with the individual injectors and other components would be difficult.
All of these disadvantages have forced engine designers to go outside the cylinder head to an adapter or a spacer, as shown in some of the prior art references, to provide the valving and linkages necessary. This increases complexity and cost.
The advantages of the barrel valve of this invention are, inter alia; its simplicity of construction and operation; i.e., its one-piece paddle-like design with guidance and sealing disks all integral; the capability of varying the amount of flow interruption through the passage by adjusting the size of the valve plate; the location of the valve in the cylinder head in a space normally not occupied by anything else, thereby permitting a hook-up of the cylinder head in a normal manner to siamesed intake manifolding; and the ability to insert the valve in a single constant diameter bore in the head close to the intake ports without interference with anything else.
While the invention has been described above and shown in the drawings in its preferred embodiment, it will be clear to those skilled in the arts to which it pertains that many changes and modifications may be made thereto without departing from the scope of the invention. | An automotive type fuel injection engine has for each cylinder a single intake manifold runner or log connected by siamesed flow passages to multiple side-by-side intake ports in the cylinder head. A fuel injector is installed in the runner upstream of the dividing portion of the runner. A single constant diameter bore is provided through the cylinder head close to the intake ports intersecting the siamesed flow passages at right angles. The bore contains a one-piece rotatable paddle-like valve with a thin plate in a flow passage, the valve being variable rotatable to close off the passage for fuel economy and power control. The valve is self-contained with sealing and guidance disks. | 8 |
TECHNICAL FIELD
The present invention relates to cam phasers for reciprocating internal combustion engines for altering the phase relationship between valve motion and piston motion; more particularly, to cam phasers having a vaned rotor disposed in an internally-lobed stator to form actuation chambers therebetween; and most particularly to an axially-compact cam phaser wherein an inverted sprocket or pulley hub bearing permits a large reduction in the axial length of the phaser compared with that of prior art phasers, while providing substantially equivalent torque capacity.
BACKGROUND OF THE INVENTION
Cam phasers are well known in the automotive art as elements of systems for reducing combustion formation of nitrogen oxides (NOX), reducing emission of unburned hydrocarbons, improving fuel economy, and improving engine torque at various speeds. As is known, under some operating conditions it is desirable to delay or advance the closing and opening of either the intake valves or the exhaust valves or both, relative to the valving in a similar engine having a fixed relationship between the crankshaft and the camshaft.
Cam phasers employ a first element driven in fixed relationship to the crankshaft and a second element adjacent to the first element and mounted to the end of the camshaft in either the engine head or block. The first element is typically a cylindrical stator mounted coaxially to a crankshaft-driven gear or pulley and having a plurality of radially-disposed chambers separated by inwardly-extending radial lobes and the second element is a vaned rotor mounted to the end of the camshaft through an axial bore in the stator and having a vane disposed in each of the stator chambers such that limited relative rotational motion is possible between the stator and the rotor. The chambers are sealed typically by front and rear face seals of the stator. The apparatus is provided with suitable porting so that hydraulic fluid, for example, engine oil under engine oil pump pressure, can be brought to bear controllably on opposite sides of the vanes in the chambers. Control circuitry and valving, commonly a multiport spool valve, permits the programmable control of the volume of oil on opposite sides of each vane to cause a change in rotational phase between the stator and the rotor, in either the rotationally forward or backwards direction, to either advance or retard the opening of the valves with respect to the position of the pistons in the cylinders.
Cam phaser designs heretofore have faced two powerful and antithetical needs: compact size and high torque capacity.
Regarding small size, many engine applications require the addition of a cam phaser unit within the envelope of an existing engine design which may have been in production for several years and which gives no special consideration to space for such a unit in the vicinity of the camshaft end. Thus, to be useful with as many engine designs as possible, a cam phaser should occupy as little volume as possible.
Regarding high torque capacity, a cam phaser must be capable of generating sufficient rotational torque between the stator and rotor to drive the advancing and retarding of valve opening and closing, which average torque for representative engines can be about 3 Nm. The rotational torque that a cam phaser is capable of generating depends on several variables including the operating temperature of the engine, the operating age of the engine, the viscosity of the oil, and numerous other known engine factors. Therefore, for smooth engine operation and rapid response under all anticipated oil pressure and use conditions, the torque capacity of a cam phaser should be substantially greater than the average torque of 3 Nm for representative engines.
Torque capacity is the product of force applied at a distance from an axis of rotation. The torque capacity (T 1 ) of a specific cam phaser can be expressed in terms of available oil pressure (P) and volume displacement per radian (V) as follows:
T 1 =PV (Eq. 1)
A volume parameter, referred to herein as the Phaser Envelope (PHE), is defined herein as pi times the square of the stator diameter D times the axial length L of the phaser, divided by 4, and represents the cylindrical volume required to contain the phaser:
PHE =(π D 2 L )/4 (Eq. 2)
The radial dynamic load imposed by the engine on the timing sprocket or pulley of the cam phaser is quite large and requires a substantial axial length of bearing between the sprocket and the camshaft to sustain the load. In prior art cam phasers, such a bearing is provided adjacent to, and axially displaced from, the stator/rotor hydraulic components of the phaser, thereby extending substantially the overall axial length of the phaser, the space required in the engine envelope to accommodate the phaser and, most significantly, the cylindrical volume or phaser envelop (PHE) required to contain the phaser. The PHE, in cm 3 , for prior art cam phasers having axially displaced bearings is typically in the range of 250 to 300. In a newer compact cam phaser design, disclosed in U.S. Patent to Lichti, et al titled “Diametrically Compact Cam Phaser”, assigned to the assignee hereof, bearing Ser. No. 09/388,103, the cam phaser has a PHE of 190 cm 3 while still maintaining a torque capacity (T 1 ) of 4.8 Nm at 20 psi oil pressure. However, in the Diametrically Compact Cam Phaser, because the bearing is displaced axially away from the stator/rotor hydraulic components, approximately 36% of the unit's total PHE is used up in providing support for the radial load of the chain drive.
What is needed is a compact cam phaser having an axial length significantly less than that of prior art cam phasers such that the Phaser Envelope can be substantially smaller at no significant sacrifice in bearing load capability or torque capacity.
SUMMARY OF THE INVENTION
The present invention is directed to an axially-compact camshaft phaser wherein the bearing on the camshaft is axially inverted, in comparison to prior art cam phasers, so that the bearing extends inwardly of the phaser stator and rotor such that the bearing function is carried out over an axial length primarily within the hydraulic portion of the phaser rather than externally thereof. The overall axial length L and phaser envelop PHE of the phaser may be thereby significantly reduced without sacrificing torque capacity.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the invention, as well as presently preferred embodiments thereof, will become more apparent from a reading of the following description, in connection with the accompanying drawings in which:
FIG. 1 is an axial cross-sectional view of the Diametrically Compact Cam Phaser taken along line 1 — 1 in FIG. 2, showing an axially displaced bearing of the prior art;
FIG. 2 is an axial-transverse cross-sectional view of the cam phaser shown in FIG. 1, taken along line 2 — 2 in FIG. 1;
FIG. 3 is an axial cross-sectional view of an axially-compact cam phaser in accordance with the invention, taken along line 3 — 3 in FIG. 4, showing an inverted bearing extending into a well in the rotor; and
FIG. 4 is an axial-transverse cross-sectional view of the cam phaser shown in FIG. 3, taken along line 4 — 4 in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
The benefits of the present invention can be more fully appreciated by first examining Diametrically Compact Cam Phaser 10 having its bearing displaced away from its stator/rotor components, as in the prior art, as shown in FIGS. 1 - 2 . Cam phaser 10 includes well-known generic components: a stator-drive element 14 (in this case, a chain drive sprocket); a stator 16 having a plurality of inwardly extending lobes 17 ; a rotor 18 having a cylindrical hub 20 and a plurality of outwardly-extending vanes 22 ; and a plurality of timing-advancing chambers 24 and timing-retarding chambers 26 being formed between the rotor vanes and the stator.
Chambers 24 and 26 are axially closed on a first side by a cover plate 28 , which can be integral with stator 16 , and on a second side by an axial face 30 of a bearing 32 , which may be integral with stator-drive element 14 . Oil for actuating the rotor with respect to the stator, by expanding the volume of chambers on first sides of the vanes and contracting the volume of chambers on second sides of the vanes, is distributed to the chambers via passages 34 .
Bearing 32 has a cylindrical bore 35 which is rotatably disposed against journal 36 of camshaft 38 , as shown in FIG. 1, to sustain the radial load imposed by the timing chain or belt in creating torque T 1 . Journal 36 defines a portion of camshaft 38 which is axially separated from end portion 40 of camshaft 38 , which may extend a distance into hub 20 , as in FIG. 1 . Thus, the load is borne on bearing elements 32 and 36 which are axially additional in length to the hydraulic elements 16 , 18 , and 28 . Hence, the use of volumetric space in the vicinity of the end of the camshaft is rather inefficient. In some engines, the outermost camshaft bearing (not shown) is near enough to the end of the camshaft that phasers designed in accordance with the prior, art bearing design cannot be fitted thereto.
Referring to FIGS. 3 - 4 , an axially-compact camshaft phaser 42 in accordance with the invention includes the above-listed generic parts. Phaser 42 exhibits torque performance at least equivalent to prior art phasers within a much smaller Phaser Envelope (PHE).
Unlike the prior art stator drive elements, drive element 14 of phaser 42 is preferably of the minimum axial thickness required structurally to sustain the sprocket working load. Further, element 14 does not extend axially away from the hydraulic elements of the phaser, as in the prior art. Instead, preferably drive element 14 is substantially smooth on its outer axial face 44 and is provided with a cylindrical bearing flange 46 extending axially inwards of phaser 42 such that the journal portion 36 of camshaft extension 48 is included within stator drive element 14 and rotor 18 . In the embodiment shown in FIGS. 3 and 4, camshaft 38 is a pre-existing camshaft which is provided with a press-fit extension 48 , although, obviously, the end of camshaft 38 itself can be formed in the shape of extension 48 within the scope of the invention.
Phasers driven by dry timing belts typically require a cylindrical “snout” (not shown) extending rearwards of drive element 14 for cooperation with a rotating oil seal to prevent engine oil from reaching the timing belt. Therefore, phasers having oil-lubricated timing chains and gears can obtain the greatest measure of axial compactness from the invention, as the snout is obviated thereby.
Extension 48 preferably is provided with an axial face 49 and a cylindrical axial extension 50 , onto which rotor 18 is pressed via central bore 52 therein such that rotor 18 is both centered on and rotationally fixed to extension 48 and hence to camshaft 38 . Kidney shaped oil grooves 54 formed in axial face 56 of rotor 18 is sealed against face 49 to form passages which communicates with radial passages 34 in hub 20 and with feed passages 33 in camshaft 38 and extension 48 to supply oil to chambers 24 . Similar radial passages 37 supply oil to chambers 26 from a supply via bore 52 . Rotor face 56 extends radially beyond the inner end of bearing flange 46 and is recessed within rotor 18 by the length I of wall 57 substantially equal to the axial length of flange 46 , face 56 and wall 57 forming thereby a well 58 , as shown in FIG. 3 .
Recessing the bearing up into the rotor/stator while maintaining the same torque capacity requires either an increase in stator axial height (H) or an increase in overall diameter (D) over the prior art. The embodiment shown in FIGS. 3 - 4 maintains the stator axial height (H) while increasing overall diameter (D). This slight diameter increase moderately increases the volume occupied by the rotor/stator hydraulic components but dramatically reduces the volume required for the bearing support. The total improvement by this invention is a 25% reduction of the overall length (L) of the cam phaser and a reduction of the PHE by 15%.
A cam phaser in accordance with the invention, having radial bearing surfaces recessed within a well in the rotor, has a phaser envelope PHE less than 190 cm 3 , a stator diameter D less than 80 mm, a stator axial height H less than 23 mm, an overall axial length L less than 40 mm, a hydraulic capacity of at least 16 ml, and a phase operating range of at least 250°, provides a torque T 1 of at least 5.0 Nm at 20 psi oil pressure. A preferred embodiment thereof, providing 5.0 Nm of torque T 1 at 20 psi has a phaser envelope PHE of 162 cm 3 , a stator diameter D of 79 mm, a stator axial height H of 22 mm, an overall axial length L of 33 mm, a hydraulic capacity of 16 ml, and a phase operating range of 30°.
The foregoing description of the invention, including a preferred embodiment thereof, has been presented for the purpose of illustration and description. It is not intended to be exhaustive nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above teachings. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, the foregoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the following claims. | An axially-compact camshaft phaser wherein the phaser bearing flange on the camshaft, connected to a timing chain sprocket or cam drive gear, is axially inverted in comparison to prior art cam phasers so that the bearing flange extends axially and inwardly of the phaser stator and rotor such that radial drive load on the phaser is sustained within the hydraulic portion of the phaser rather than externally thereof. The overall axial length of the phaser may be reduced thereby by about 25% relative to some prior art phasers and the Phaser Envelop volume may be reduced by 15% while maintaining an equivalent torque capacity. | 8 |
FIELD OF THE INVENTION
The present invention relates to a method in optical fiber based spectral filtering. The invention further relates to a spectral filter device implementing the method.
BACKGROUND OF THE INVENTION
Telecommunications based on optical fibers is a rapidly evolving technical field. In addition to long distance transmission fibers replacing more traditional conducting wire cables, a large variety of other types of optical fiber components are also required in order to make up a complete modern optical telecommunication system. Such components include, for example, optical amplifiers based on rare-earth metal doped active fibers and different types of spectral multiplexing and filtering devices. Spectral filtering in various forms is especially important in systems based on wavelength division multiplexing, WDM.
It is known that an optical fiber, more specifically a single mode fiber can be used as a spectral filter device by coiling the fiber around a reel or corresponding circular body in order to subject the fiber lengthwise to a certain continuous curvature. The radius of this curvature determines the cut-off wavelength of such a coiled fiber filter. With smaller radius of the curvature the cut-off wavelength moves towards shorter wavelengths. When the wavelength of the light transmitted through the fiber core exceeds the aforementioned cut-off wavelength, the optical power starts to leak from the fiber core to the cladding layer surrounding the core. In the cladding layer the light experiences significantly higher attenuation than in the fiber core. The overall attenuation characteristics of a the fiber filter can be controlled by the number of fiber turns coiled around the reel.
In practise, the operation of a coiled fiber filter deviates from ideal because above the cut-off wavelength all of the wavelengths do not become attenuated equally and homogeneously. Because only a finite number of guided modes exits in the cladding layer, some wavelengths become coupled to cladding modes more effectively than others. The limited number of cladding modes gives rise to a certain amount of unwanted coupling of the light from the cladding layer back to the fiber core, i.e. reversed coupling effects. As a result of these aforementioned effects, the typical transmission of a prior art coiled fiber filter shown in FIG. 1 as graph P is not a smooth downward curve after the cut-off wavelength λ off , but instead shows significant “interference” peaks at certain wavelengths. For comparison, FIG. 1 also shows a more desirable smooth transmission graph I of a more ideal low-pass filter.
From the prior art certain solutions are known in order to reduce the aforementioned effects. These solutions are primarily based on the idea of increasing the attenuation of the cladding layer and/or by arranging the cladding layer to be surrounded with a specific envelope layer, which allows the light to leak from the cladding layer further to this outside envelope or jacket layer. However, these prior art solutions have certain significant limitations. Because they are basically based on increasing the attenuation of the cladding layer, they are not suitable for those applications where also the cladding layer itself is utilized as an optical waveguide. Such applications include, for example, cladding pumped optical fiber amplifiers, where the pump light propagating in the cladding layer should not become attenuated due to the intrinsic optical properties of the cladding layer.
SUMMARY OF THE INVENTION
The objective of the present invention is to introduce a new approach that makes it possible to construct optical fiber based spectral filtering devices, whose spectral properties are superior to the prior art devices. Especially, the intention is to achieve filter devices where after the cut-off wavelength the transmission drops down more smoothly than in the prior art devices. Further, one specific objective of the invention is to construct devices, which are also suitable to be used in the kind of applications, where, in addition to the fiber core, also the cladding layer of the fiber has a role of acting as an optical waveguide. An important example of such application can be found among cladding pumped fiber amplifiers.
In this invention it has been rather surprisingly discovered that the performance of a coiled optical fiber filter can be significantly improved when the fiber is twisted over its length in whole or in part around its longitudinal axis in addition to subjecting it to a certain longitudinal curvature.
In order for the longitudinal twisting of the fiber to have the desired effect, the optical fiber needs to be of a type without radial symmetry, i.e. radially asymmetrical fiber. Such radially asymmetrical optical fibers are known as such from the prior art. Radial asymmetry can be achieved, for example, by using an off-centered core, or by providing a cladding layer where the refraction index varies in a radially asymmetrical manner. Radial asymmetry may also be achieved by using optical fiber structures, where the cross-section of the fiber core (or even cladding) is non-circular. Such fibers are known from polarization sensitive applications. Fundamentally, in this context the radial asymmetry refers broadly to any optical fiber structures where the radial distribution of the refractive index is asymmetrical.
In an optical fiber filter, where the fiber is both coiled and twisted according to the invention, the leak of light from the fiber core to the cladding layer takes place more ideally than in the prior art filters, i.e. without significant amount of reversed coupling effects. Above the cut-off wavelength all wavelengths thus “see” temporally substantially equal amount of matching with the cladding modes. In other words, when a certain length of the twisted and coiled optical fiber is considered, with high probability, there always exist such cladding modes which allow the light to become coupled from the core to the cladding.
As a result of this the transmission curve of the device has a smoothly descending behaviour after the cut-off wavelength.
The current invention is especially suitable to be used as a distributed spectral filter in cladding pumped fiber amplifiers, because the fiber structure allows the propagation of the pump light in the cladding layer.
For a person skilled in the art, it is clear that compared to the prior art solutions, the invention significantly widens the possibilities to optimize the fiber filter structures. Without “interference” peaks the cut-off wavelength and the attenuation properties of the fiber filter can be more freely adjusted than in the prior art devices.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be described in more detail with reference to the appended drawings, in which
FIG. 1 shows schematically a typical transmission behaviour of a prior art coiled fiber filter together with a more ideal smooth transmission curve,
FIG. 2 shows some experimental and comparison results illustrating the basic transmission properties of an optical fiber filter according to the invention,
FIGS. 3 a,b describe conceptually the propagation of light in a substantially straight and radially symmetric fiber,
FIGS. 4 a,b describe conceptually the propagation of light in a longitudinally curved and radially symmetric fiber, and
FIGS. 5 a,b,c describe conceptually the propagation of light in a longitudinally curved and radially asymmetric fiber, which has been twisted around its longitudinal axis according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following conceptual explanation is meant to describe, in a simplified way, some of the most important physical phenomena behind the invention. It should be noted that this description is not intended to be scientifically exhaustive, but it is only meant to help recognise the most essential features of the invention.
To begin, a few measurement results are presented in FIG. 2 in order to illustrate the effect that can be achieved when the optical fiber in a coiled fiber filter is additionally twisted around its longitudinal axis according to the invention. It should be understood, that the results in FIG. 2 and the construction of the corresponding fiber filter devices are provided only to illustrate the effect itself and therefore do not necessarily correspond with the results or construction of any practical fiber filter device.
The measurement results shown in FIG. 2 have been recorded using an approximately 2 meter long single-mode fiber having an off-centered core, i.e. a radially asymmetric construction. The fiber core diameter was 6 μm and the total diameter of the fiber including the cladding layer was 125 μm. The core was located approximately 30 μm from the center. The refractive index distribution of the fiber was of the same “W-type” as schematically shown in FIGS. 5 a – 5 c , i.e. with a depressed refractive index cladding region G next to the fiber core.
In FIG. 2 graph C 70 first shows the transmission for the aforementioned off-centered fiber, which has been coiled without twisting one lap around a reel with an approximately 70 mm diameter. Therefore, graph C 70 may be regarded to correspond to the performance of a prior art type fiber filter, such as shown schematically in FIG. 1 with graph P. Graph TC 70 shows the transmission of the same fiber in an otherwise similar situation, except that in this case the fiber was twisted around its longitudinal axis according to the invention. After coiling the fiber was twisted so that the fiber experienced an approximately 720° twist around its longitudinal axis substantially evenly along its coiled length. In other words, the fiber was first coiled one turn around the 70 mm reel. Then the fiber was fixed from the starting point of the turn to the reel and the fiber was twisted approximately two full turns from the point close to the ending point of the lap. It can be clearly seen, that graph TC 70 corresponds to much more desirable transmission properties than graph C 70 .
For comparison, FIG. 2 also contains additional graphs MS 70 and MS 150 . These graphs correspond to coiled, but non-twisted fibers with reel diameters of approximately 70 and 150 mm, correspondingly. The coating of these fibers was stripped off and immersion oil was further used for mode stripping, i.e. for elimination of the cladding modes.
In the following, with reference to FIGS. 3 a – 5 c , the basic physical phenomena behind the invention are further explained together with some possible embodiments of the invention.
FIGS. 3 a , 3 b describe conceptually the propagation of light in a substantially straight and radially symmetric fiber 30 comprising a core region CR and a cladding region CL. FIG. 3 a shows in its upper section the refractive index profile R and the corresponding mode field M of the fiber 30 . In this case the refractive index profile R includes a narrow depressed refractive index cladding region G in the cladding next to the fiber core. In this depressed refractive index cladding region G the refractive index is arranged to be somewhat lower than in the other outer parts of the cladding region CL. Such “W-type” refractive index profiles R having a certain depressed region G in the refractive index around the fiber core are known as such from the prior art. Respectively, FIG. 3 b shows conceptually in its upper section the core mode propagation constant PCR and the cladding mode propagation constants PCL depicted with horizontal solid lines.
When the wavelength of the light changes, this affects the core mode propagation constant PCR in a known manner. This effect is depicted in FIG. 3 b with arrow A. The core mode propagation constant PCR depends substantially linearly on the wavelength. When the core mode propagation constant PCR decreases the amount of mode field M in the cladding region CL increases exponentially. When the wavelength of light increases, the core mode propagation constant PCR becomes smaller and when the core mode propagation constant PCR and that of the cladding modes PCL coincide, there exists strong coupling from the core mode to the cladding modes. The amount of the mode field in the cladding region CL gives the coupling coefficient between the core mode and the cladding modes. If and when the propagation constants are the same for the core mode and a cladding mode, the power starts to go back and forth between these two modes.
FIGS. 4 a , 4 b describe in a similar conceptual manner the propagation of light in a longitudinally curved and radially symmetric fiber 40 . Therefore, FIGS. 4 a , 4 b describe the basic phenomena covering the operation of a prior art coiled fiber filter.
From FIGS. 4 a , 4 b it can be seen that the curvature of the fiber 40 (to the left in FIGS. 4 a , 4 b and also in FIGS. 5 a – 5 c ) causes an increase in the refractive index in the outer bend of the fiber 40 . Therefore, the refractive index profile R becomes tilted as schematically shown in the upper sections of FIGS. 4 a , 4 b . Correspondingly, the propagation constants of the modes in the cladding region CL in the outer bend become elevated. This lowers the cut-off wavelength for a coiled and curved fiber.
The “interference” peaks shown in FIGS. 1 and 2 (graphs P and C 70 , respectively) arise due to the fact that there exists only a finite number of propagating modes in the cladding layer CL. Therefore, for certain wavelengths above the cut-off wavelength the conditions become such, that the light power is able to couple to the cladding layer CL (and back) only at certain occasions when moving along the length of the fiber 40 . In other words, when a certain length of the fiber 40 is considered, the different wavelengths become treated unequally in what comes to the coupling between core CR and cladding CL and to the consequential loss of the light from core CR.
FIGS. 5 a – 5 c now describe conceptually the propagation of light in a longitudinally curved and radially asymmetric fiber 50 , which has been further twisted around its longitudinal axis according to the invention. FIGS. 5 a – 5 c describe three different situations with a relative twist of approximately 90° between FIGS. 5 a and 5 b , and again the same between FIGS. 5 b and 5 c.
Because of the twist of the fiber 50 , in different locations along the fiber length, the core mode propagation constant PCR can be found to have moved compared to the cladding modes PCL. The reason for this is that when moving along the length of the twisted and coiled fiber 50 , the core CR moves into different positions compared to the outer curved surface (cladding surface) of the fiber (see lower sections of FIGS. 5 a – 5 c ). This “averages” the coupling between the core mode to a certain set of the cladding modes. Now, above the cut-off wavelength substantially all wavelengths, i.e. substantially all core mode propagation constants PCR, “see” temporally an equal amount of matching with the cladding modes PCL. In other words, when a certain length of the fiber 50 is considered, such cladding modes which allow the light to become coupled from the core to the cladding always exist. As a result of this, above the cut-off wavelength the transmission of the fiber 50 has a smooth descending behaviour without disturbing interference peaks.
In the lower sections of FIGS. 5 a – 5 c the hatched area CA depicts the cross-sectional area in which the cladding mode propagation constants PCL are equal or higher than the core mode propagation constant PCR. In those situations the core and cladding modes have possibility to match and energy can move from the core to the cladding layer.
In order for the longitudinal twisting of the fiber 50 to have the desired effect, the fiber 50 needs to have a certain degree of radial asymmetry. In the embodiment described in FIGS. 5 a – 5 c the radial asymmetry is achieved by using an optical fiber 50 with an off-centered core CR. However, the current invention is not limited to such embodiments, but also other means for providing radial asymmetry of the refractive index distribution may be applied. For example, radial asymmetry in a fiber can be achieved by providing a cladding layer CL where the refraction index varies in a radially asymmetrical manner. Radial asymmetry may also be achieved by using such fiber structures, where the cross-section of the fiber core CR and/or the fiber cladding CL is non-circular. Such fibers are known, for example, from certain polarization sensitive applications where the fiber core is non-circular or cladding pumped fibers where the fiber cladding is non-circular.
It should be noted, that even if the fiber 50 shown in FIGS. 5 a – 5 c includes the depressed refractive index cladding region G in the cladding layer next to the fiber core, this is not an absolute necessity for a fiber filter according to the invention. Such a structure, however, is preferable in many applications because it makes the filtering effect sharper.
The current invention is especially suitable to be used as a distributed spectral filter in cladding pumped fiber amplifiers, because the fiber structure now allows the propagation of the pump light in the cladding layer. For a person skilled in the art, it is clear that compared to the prior art solutions the invention significantly widens the possibilities to optimize the fiber filter structures. Without “interference” peaks the cut-off wavelength and the attenuation properties of the fiber filter can be freely engineered and fine-tuned according to the respective needs.
The invention also makes it possible to use very large fiber core designs (>10 um), which can handle higher laser powers without problems created by non-linear optical phenomena.
An important benefit of the invention is that the fiber filter devices according to the invention are simple to manufacture also in practise. In addition to coiling an optical fiber, the fiber only needs to be twisted around its longitudinal axis either before, during or after the coiling process. The strength of the effect can be adjusted by selecting the amount of twisting (degrees or turns) per a certain length of the fiber. The twisting may be arranged to appear evenly along the total length of the fiber, or to be concentrated only to certain parts of the fiber. In a fiber filter having several laps coiled around a reel, the twisting may be arranged to distribute over all of the coiled laps or only to some or one of the coiled laps. Depending on the amount of radial asymmetry of the fiber, the amount of twisting may be freely adjusted to accomplish desired transmission properties. These and other parameters, including the length and the optical properties of the fiber, may be freely selected.
Even though the invention has been shown and described above with respect to selected types of embodiments, it should be understood that these embodiments are only examples and that a person skilled in the art could construct other fiber filter devices utilizing techniques other than those specifically disclosed herein while still remaining within the spirit and scope of the present invention. It should, therefore, be understood that various omissions and substitutions and changes in the form and detail of the filter devices illustrated, as well as in the operation of the same, may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to restrict the invention only in the manner indicated by the scope of the claims appended hereto. | A method and a device in optical fiber based spectral filtering. A length of an optical fiber including at least a core region surrounded by a cladding region is coiled over its length in whole or in part to subject the fiber to longitudinal curvature in order to affect the optical transmission properties of the fiber. The fiber is arranged to have radially asymmetric refractive index distribution and in addition to coiling the fiber lengthwise, the fiber is over its length in whole or in part also twisted around its longitudinal axis. The method and device can be used to significantly improve the performance of fiber based filtering devices. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 08/797,198, filed Feb. 11, 1997, now U.S. Pat. No. 5,907,577.
The invention disclosed herein is related to the US patent application by Alamouti, al., entitled “Method for Frequency Division Duplex Communications”, Ser. No. 08,796,584, filed Feb. 6, 1997, now U.S. Pat. No. 5,933,421, assigned to AT&T, and incorporated herein by reference.
FIELD OF THE INVENTION
This invention involves improvements to delay compensation systems and methods in a wireless discrete tone communications system.
BACKGROUND OF THE INVENTION
Wireless communications systems, such as cellular and personal communications systems, operate over limited spectral bandwidths and must make highly efficient use of the scarce bandwidth resource to provide good service to a large population of users. The Personal Wireless Access Network described in the Alamouti, et al. Patent application cited above, is an example of a successful technology for wireless service.
The personal wireless access network (PWAN) system described in the referenced Alamouti et al. patent application, uses a form of protocol known as discrete tone to provide efficient communications between a base station and a plurality of remote units. In this protocol, the user's data signal is modulated by a set of weighted discrete frequencies or tones. The weights are spatial spreading codes that distribute the data signals over many discrete tones covering a broad range of frequencies or tones. The weights are complex numbers with the real component acting to modulate the amplitude of a tone while the complex component of the weight acts to modulate the phase of the same tone. Each tone in the weighted tone set bears a different data signal. The weighted tone set for a particular user is transmitted to the receiving station where it is processed with spatial despreading codes to recover the user's data signal. For each of the spatially separated antennas at the receiver, the received discrete tone signals are transformed from time domain signals to frequency domain signals. Despreading weights are assigned to each frequency component of the signals received by each antenna element. The values of the despreading weights are combined with the received signals to obtain an optimized approximation of individual transmitted signals characterized by a particular discrete tone set and transmitting location. The PWAN system has a total of 2560 discrete tones (carriers) equally spaced in 8 MHz of available bandwidth in the range of 1850 to 1990 MHz. The spacing between the tones is 3.125 kHz. The total set of tones are numbered consecutively from 0 to 2559 starting from the lowest frequency tone. The tones are used to carry traffic messages and overhead messages between the base station and the plurality of remote units. The traffic tones, are divided into 32 traffic partitions, with each traffic channel requiring at least one traffic partition of 72 tones.
In addition, the PWAN system uses overhead tones to establish synchronization and to pass control information between the base station and the remote units. A Common Link Channel (CLC) is used by the base to transmit control information to the Remote Units. A Common Access Channel (CAC) is used to transmit messages from the Remote Unit to the Base. There is one grouping of tones assigned to each channel. These overhead channels are used in common by all of the remote units when they are exchanging control messages with the base station.
In the PWAN system, Frequency Division Duplexing, (FDD) is used by the base station and the remote unit to transmit data and control information in both directions over different frequencies. Transmission from the base station to the remote unit is called forward transmission and transmission from the remote unit to the base station is called reverse transmission. The base station and each remote unit must synchronize and conform to the timing structure and both the base station and the remote unit must synchronize to a framing structure. All remote units and base stations must be synchronized so that all remote units transmit at the same time and then all base stations transmit at the same time. When a remote unit initially powers up, it must acquire synchronization from the base station so that it can exchange control and traffic messages within the prescribed time format. The remote unit must also acquire phase synchronization for the signals so that the remote is operating at the same frequency and phase as the base station.
When a remote unit is first installed, it transmits a signal over the CAC channel to the base station. This signal will probably be received at the base station at a time which is not the same as the other remote units transmitting to the base station. The difference between the expected time of the signal, and the time that the signal actually arrives at the base station, is the delay.
Previous systems that compensate for this delay have included systems which have a delay time measurement resolution that is limited. Furthermore, delay time measurement in a protocol is subject to both noise noise and multipath fading.
SUMMARY OF THE INVENTION
This invention solves the delay compensation problem by providing the base station with the ability to measure the magnitude and angle of the phase of delay compensation tones transmitted by the remote unit (RU) on the Common Access Channel (CAC), and calculating the slope of the phase ramp across the frequency range. Because the delay is proportional to the slope of the phase ramp, the delay can be calculated and transmitted to the RU on the Common Link Channel. The RU is provided with the ability to adjust the timing of the signals sent from the RU to the base station on the CAC.
The delay compensation pilots are discrete tones with frequencies that are uniformly spaced throughout each of the upper and lower sub-band frequency ranges. These tones are transmitted by the RU on the CAC and received by the base station. The received tones are digitized, sampled, passed through a Fast Fourier Transform (FFT) processor and stored in FFT incremental frequency bins as complex numbers. These numbers represent points in a 16 Quadrature Amplitude Modulation (QAM) constellation and are related to the average amount of energy of the received tone in the increment of frequency represented by the FFT bin.
In accordance with this invention, the base station uses the information about the signals received, as represented by the FFT bins, to calculate the amount of delay and prepare a signal containing the corresponding amount of compensation to be sent to the RU on the CLC.
In accordance with the invention, the phase difference between the expected phase angle and the received phase angle is calculated for each delay compensation pilot (DCP) tone. The difference in phase between each successive DCP tone is proportional to the time delay and the uniform frequency difference between tones. Because of this, the plot of phase difference as a function of frequency is a constant slope line, where the slope is proportional to the time delay.
In a first embodiment of the invention, the phase angle differences are measured by taking the FFT output representing the first DCP and multiplying it by the complex conjugate of the all sixteen of the FFT outputs from one of the two sub-bands. This gives sixteen phase angle measurements for slope calculation.
In a second embodiment of the invention, each symbol corresponding to the 16 elements of the QAM constellation is correlated with each symbol sequence from the sixteen FFT outputs from one sub-band. This allows sixteen phase-angle measurements based on the correlation coefficients.
In a third embodiment of the invention, the output of the FFT from both sub-bands is used. Sixteen symbol sequences are created from each sub-band, and then the first sequence of each sub-band are added to each other, then the second sequence of each sub-band, and so on until the sixteenth sequence of each sub-band are added together. Sixteen phase angle measurements are generated when the QAM symbol sequence is correlated with each of the 16 symbol sequences.
In a fourth embodiment of the invention, the output of the FFT from both sub-bands and from eight antenna elements is used. Sixteen symbol sequences are received from each sub-band for each antenna element. Sixteen symbol sequences are created when the 32 first sequences of each sub-band for each antenna element are summed, then the 32 second sequences of each sub-band for each antenna are summed, and so on until the 32 sixteenth sequences of each sub-band for each antenna are summed. Each summed sequence is normalized and correlated with the QAM symbol sequence to generate 16 phase angle measurements.
Currently, the invention has advantageous applications in the field of wireless communications, such as cellular communications or personal communications, where bandwidth is scarce compared to the number of the users and their needs. Such applications may be effected in mobile, fixed, or minimally mobile systems. However, the invention may be advantageously applied to other, non-wireless, communications systems as well.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing signals sent and received at a base station.
FIG. 2 is a block diagram showing how a delay compensation method acts to synchronize the signals of multiple remote units.
FIG. 3 is a plot showing a best-fit line for nine data points.
FIG. 4 is a plot showing how phase wrapping results from the use of an arctan function.
FIG. 5 shows the mapping between Delay Compensation Pilots and the PWANs tone number.
FIG. 6 shows how the Second Pass algorithm is implemented to provide phase angle measurements from 16 data points.
FIG. 7 shows how the Third Pass Algorithm is implemented to provide phase angle measurements from 32 data points.
FIG. 8 shows how the Final algorithm is implemented to provide phase angle measurements from 256 data points.
DETAILED DESCRIPTION
In the personal wireless access network (PWAN) application, there is a need for the radio signals from each remote unit (RU) to arrive at the base station at the same time. The RUs are at different distances from the base station. It takes a finite amount of time for signals from each RU to travel to and from the base station. It takes approximately 1 ns per foot for signals to propagate from the transmitter to receiver.
When a RU is installed, it needs to know when to transmit its signals in relation to the signals received from the base station so that its signal will arrive at the base station at the same time as the signals from the other Rus. The base station measures the difference between the expected time of arrival and the actual time of arrival of the RU signals. It then transmits this measurement information to the RU so it can advance or delay the time that it sends signals to the base station.
FIG. 1 shows the signals that appear at the base station. The base station expects to see the signals from the RU arrive 225 ms after it transmits its last burst. FIG. 2 shows the signals that appear at the base and the RU. Before the RU is compensated, the signals it transmits arrive at the base at a time that is different from the signals transmitted by the other Rus. The base measures the delay and transmits the measurement to the RU. The RU then adjusts the time of transmission to compensate for the delay.
Delay compensation can be performed upon installation and also at every call setup. The delay compensation calculation routine examines the average signal power in the signals used for the delay calculations and if they are above a certain threshold then a delay compensation measurement is made.
Phase Shift In Time-Delayed Sinusoids
There are sixteen tones available to the RU in each of the upper and lower sub-bands of a sub-band pair for Delay Compensation measurement purposes. These tones are referred to as Delay Compensation Pilots (DCPs).
The RU transmits the DCPs to the base station with each DCP having the same phase shift. If the RU has been compensated properly the DCP tones arrive at the base station in phase with each other. If the signal from the RU is delayed then each of the DCP tones experiences a phase shift.
A single DCP can be represented as a time domain signal in the form:
DCP n (t)=sin (2 πf n t+φ n )
If the signal is delayed by a time of τ then the equation of the delayed signal is:
DCP n ( t )=sin (2 f n ( t −τ)+φ n )=sin (2πf n t −2 πf n τ+φ n )
Thus a phase difference of −2πf n τ is introduced by the delay. Each of the DCPs are delayed by the same time, τ. When τ=0, the DCPs all have the same phase. When τ≠0, each of the DCPs has a phase difference proportional to the frequencies of the DCPs.
In the base, tones are 3.125 Khz apart. If two adjacent tones with the same phase are delayed by a time τ, then the phase difference of the delayed tones is 2π(3.125 kHz)τ. Thus for every microsecond the signal is delayed, the phase of the adjacent tones defers by 0.019635 radians.
The Base measures the phase of each DCP and uses linear regression to fit the phases to a straight line. The slope of this line is proportional to the delay. A slope of zero indicates that no delay compensation is needed. A positive slope means that the signal is arriving too early and the RU needs to advance transmission of its signal.
Measuring Phase Differences
A tone can be represented by a complex value a+ib. this can also be written in the form Ae jθ , where A=(a 2 +b 2 ) ½ and Θ=tan −1 (b/a). Here, A represents the magnitude of the tone and Θ represents the phase angle of the tone.
There are several ways of measuring the phase difference between two tones. One way is to calculate the phase of each tone and subtract them. This is computationally expensive however, as it requires two arctan computations and two divisions. Another way is to multiply the first complex value by the complex conjugate of the other. Mathematically, this is expressed as:
A 1 e jθ1 ×B 1 e −jφ1 =A 1 B 1 e j(θ1−φ1 )
This results in a complex value that has a phase angle equal to the difference in phases of the two original values. Now, a single arctan and a division can be performed to determine the phase of this value.
If we have a sequence, A, of complex values A 1 e jθ1 , A 2 e jθ2 , . . . A n e jθn that are then phase shifted by slightly different amounts, and also attenuated by different amounts to give the sequence B: B 1 e jφ1 , B 2 e jφ2 , . . . B n e jφn , we can calculate an average phase shift by correlating the original sequence of values with the resulting sequence. Correlation of the sequence A, with the sequence B is defined here as ∑ i = 1 n A i j θ i B i - jφ i
The result of the correlation is known as the correlation coefficient. This is a complex value that has a phase angle equal to a weighted average of the phase differences of the corresponding elements of A and B. If the phase difference between the ith element of each sequence is constant then the correlation coefficient has a phase angle equal to this difference.
Correlation is a function that is very fast to perform on a digital signal processor (DSP) as it consists only of multiplications and additions.
Linear Regression
FIG. 3 shows how Linear Regression is used to find a line that is the ‘best fit’ to a set of data points. If is assumed that the data x-coordinates are known exactly and that the y-coordinate error is normally distributed. FIG. 3 shows some data points and the best fit line through those points. The ‘best fit’ in this case minimizes the sum of the squares of the errors between the y-coordinate of each point and the y value of the line for the x-coordinate of the point. The error, e i for one of the points is indicated in FIG. 3 .
Linear regression is explained in many references. See, e.g.: Press et al., Numerical Recipes in C, ad, ed., Cambridge University Press 1992; Chapra et al., Numerical Methods for Engineers, ad. ed., McGraw-Hill 1989. linear regression algorithm is also included here to aid understanding of how it works and how it used in the Delay Compensation algorithm of this invention.
Let e i be the error associated with the point (x i , y i ). Let the equation of the line be y=mx+c. The square of the error e i is given by: e i 2 −(y i −mx i −c) 2
The sum of the squares of the errors is given by: ∑ i = 1 n e i 2 = ∑ i = 1 n ( y i - mx i - c ) 2
where there are n data points.
To minimize the sum of the squares, it is differentiated with respect to m and with respect to c to give two simultaneous equations: c ∑ i = 1 n e i 2 = - ∑ i = 1 n 2 ( y i - mx i - c ) = - 2 ∑ i = 1 n y i + 2 m ∑ i = 1 n x i + 2 cn m ∑ i = 1 n e i 2 = - ∑ i = 1 n 2 x i ( y i - mx i - c ) = - 2 ∑ i = 1 n x i y i + 2 m ∑ i = 1 n x i 2 + 2 c ∑ i = 1 n x i
For the best fit line, e i 2 is at a minimum and the derivatives of e i 2 are equal to zero. Setting the above equations equal to zero and solving for m gives: m = n ∑ i = 1 n x i y i - ∑ i = 1 n x i ∑ i = 1 n y i n ∑ i = 1 n x i 2 - ( ∑ i = 1 n x i ) 2
Once m is calculated, c can be found by back substitution as follows:
c={overscore (y)}−{overscore (mx)}
where the x and y are the mean values of y and x, respectively.
The formula for calculating m can also be written as: m = ∑ i = 1 n y i ( x i - x _ ) ∑ i = 1 n ( x i - x _ ) 2 = ∑ i = 1 n y i t i
where: t i = x i - x _ ∑ i = 1 n ( x i - x _ ) 2
This can be verified by direct substitution. If the x i values are the same each time the linear regression algorithm is called, as they are in the case of the delay compensation algorithm, then the t i values can be calculated once, at initialization, and the slope of the line is calculated by multiplying each y i by each t i and summing the results.
In the Delay Compensation algorithm, it is necessary to only solve for m and the final step of solving for c can be left out. The x i terms remain the same for each iteration of the delay compensation algorithm, so the process of fitting data to a best fit line and finding its slope can be implemented with one multiply and one addition per point on the line. This algorithm is ideally suited for implementation on a DSP.
Unwrapping Phase Angles
The phase angle of a complex value a+jb lies in the range 0 ±π. If we write this value in the form
Ae jθ then A={square root over ( a 2 +b 2 )} and θ=tan −1 (− b/a )
The tan −1 function returns a value between −π and π. If θ is incremented continuously and a graph of the phase angle of Ae jθ is plotted, the graph in FIG. 4 is the result. The phase angle increments until it reaches n and then jumps back down to −π. This is known as phase wrapping.
In the Delay Compensation algorithm of this invention the phase angle of each tone is calculated and the best straight line fit of these angles is calculated. However, the phase angles are in the range 0±π and need to be unwrapped before the linear regression algorithm is used on them.
To use the phase unwrapping algorithm, a positive cutoff point (pos_cut) and a negative cutoff point (neg_cut) need to be chosen. The cutoff points are used to decide when an angle needs to be unwrapped. If the difference between two phase angles is outside the range of the cutoff angles then the angles need to be unwrapped. Good, general purpose values for pos-cut and neg-cut are +π and −π respectively.
In the case of the base station, cutoff points of +π and−π are good first choice candidates. In simulations, these cutoff angles allowed Rus to be compensated at distances of up to approx 8000 feet. Once the Rus were positioned further away than 8000 feet, the phase difference between the angles was greater than −π. The unwrap algorithm treats this as a phase difference in the positive direction and doesn't unwrap directly in the positive direction and doesn't unwrap correctly. The way to fix this problem and allow Rus to be compensated at distances of greater than 8000 feet is to change the phase wrap cutoff points. Cutoffs of +π/2 and −3π/2 allows Rus to be compensated at up to 12000 feet. Cutoffs of +π/4 and −7π/4 could allow compensation at distances of up to 14000 feet.
The phase unwrapping algorithm first creates an array A and sets the first element in A equal to the first phase in the sequence. Next, it finds the difference between adjacent phases and stores these differences in A. The second element in A is set to the difference of the first and second phase angles etc.
The algorithm then creates another array, P. For every entry in A greater than pos_cut, that entry in P is set to −2π. For every entry in A less than neg_cut, that entry in P is set to +2π. If an entry in A is in the range neg_cut to pos_cut then the corresponding entry in P is set to 0.
Next each entry in P is replaced by the cumulative sum of all the previous entries. This is done by summing the entries starting at the first element and replacing each element by the sum so far. Once this is done, these elements of P are added to the original phases to give the unwrapped angles.
Phase Unwrapping Example
This example uses the algorithm described above with cutoff points of 0±π to unwrap a typical set of phase angle. The sequence of phase angles is:
{−0.1 −1.2 −2.2 −3.1 2.9 1.4 0.6 −0.8 −1.9 −2.7 2.8}
The array A is:
{−0.1 −1.1 −1.0 −0.9 6 −1.5 −0.8 −1.4 −1.1 −0.8 5.5}
The array P is:
{0 0 0 0 −6.28 0 0 0 0 0 −6.28}
Summing P and replacing each entry with the sum so far gives:
{0 0 0 0 −6.28 −6.28 −6.28 −6.28 −6.28 −6.28 −12.56}
Adding this to the original phase angles gives:
{−0.1 1.2 2.2 −3.1 −3.38 −4.88 −5.68 −6.88 −7.08 −8.18 −8.98 −9.76}
These phases are in a form that can be fitted to a straight line.
DCP Tone Mapping
There are 320 tones in each of the upper sub-band of a sub-band pair. Of these 320 tones, 16 are used for delay compensation purposes. They are spaced 20 tones apart throughout the sub-band. The first DCP in a sub-band is at position 0 , the next at position 20 , etc., with the last tone at position 300 . The tones in one sub-band are shown in FIG. 5 The DCPs in a given sub-band are numbered DCP 0 to DCP 15 .
For every microsecond the signal form the RU is delayed, there is a phase difference of 0.3927 radians between adjacent DCPs in a sub-band.
Delay Compensation Algorithm
In order to minimize the effects of multipath fading that occur when signals are transmitted between the RU and the base station, DCPs are transmitted during eight consecutive bursts from the RU. Each burst contains 16 DCPs on the upper sub-band and a further 16 DCPs in the lower sub-band.
There are 8 symbols transmitted on the DCPs—one in each burst. This symbol set, S, is represented as S 0 , S 1 , . . . S 7 . S 0 is transmitted on all the DCPs of the first burst. S 1 is transmitted on all the DCPs of the second burst etc. The symbols are encoded using QPSK encoding and are normalized so their average power is equal to the average power of the traffic channel data.
The actual symbol set transmitted is:
S=[1 −i , −1 +i , 1 +i , −1 +i , −1 −i , −1 +i , −1 −i , 1 −i]×f n
where f n is the normalization factor.
The actual Delay Compensation Algorithm is best described in incremental stages. This helps show how the algorithm has been developed to make it as immune as possible to noise and multipath fading.
A first pass at calculating the phase difference of the DCPs is to simply take the DCPs of the upper or lower sub-band of one tone burst and multiply the first DCP by the complex conjugate of the other DCPs. This gives the phase difference between the DCP and the other DCPs in that burst. These phase differences can then be unwrapped and fitted to a straight line using linear regression. The slope of the line is proportional to the delay.
The above is a perfectly valid method of measuring the delay in the absence of noise, multipath channel fading and other interference. When these factors are taken into account, this algorithm doesn't provide reliable results and a more robust algorithm is required.
FIG. 6 shows how the Second Pass Algorithm is implemented. A second pass algorithm takes into account the DCPs from the upper or lower sub-band of all the tone bursts. Sixteen sequences are created from the DCPs in each burst. The first sequence consists of the DCP 0 from each burst. The second sequence consists of the DCP 1 form each burst, etc. The symbol set S is then correlated with each of these sequences. This results in sixteen correlation coefficients. The phase of each coefficient is then calculated and these phases are unwrapped and fitted to a best fit line using linear regression. Once again, the slope of the line is proportional to the delay in the signal from the RU.
This algorithm is much more robust than the first pass algorithm and averages out the effects of noise and multipath fading.
FIG. 7 shows how the Third Pass algorithm is implemented. Even more accurate results can be obtained by using the DCPs from the upper and lower sub-bands off one antenna element. Thirty two sequences are created from the DCPs from eight bursts. The first sequence, S 0 consists of the DCP 0 from the lower sub-band of each burst. The second sequence, S 1 consists of the DCP 1 from the lower sub-band of each burst, etc. The seventeenth sequence, S 16 consists of the DCP 0 from the upper sub-band of each burst etc.
Next S 0 and S 16 are correlated with other. This results in a correlation value, the phase angle of which is the phase difference of the two sequences. This correlation value is normalized to give it an absolute value of one. Next, S 16 is multiplied by the normalized autocorrelation value. This effectively ‘rotates’ the sequence S 16 to give it the same phase as S 0 . Finally the corresponding elements of S 0 and S 16 are summed together. This sum also has the same phase as S 0 in the sense that if this sum is correlated with S 0 , a real value results. This procedure is repeated for S 1 and S 17 , S 2 and S 18 and so on until S 18 and so until S 15 and S 31 have been summed.
The original symbol set S is then correlated with each of these newly generated sequences. This results in sixteen correlation coefficients. The phase of each coefficient is then calculated and these phases are unwrapped and fitted to a best fit line using linear regression. Once again, the slope of the line is proportional to the delay in the signal from the RU.
Simulations have shown that this algorithm improves upon the results of the second pass algorithm.
FIG. 8 shows how the Final Algorithm is implemented. The Final Algorithm uses the DCP tone information from all eight antenna elements. Each antenna provides 32 sets of eight symbols. There are 32 DCPs per burst from each antenna, and eight bursts. Each set of symbols is made up of eight DCPs from one antenna, one DCP from each burst. The symbol sets from antenna 0 are numbered S 0 to S 31 . Those from antenna 1 are numbered S 32 to S 63 etc. Those from antenna 7 are numbered S 240 to S 255 (see FIG. 4 . 8 ). together and then the sum is correlated with the original symbol set, S, to determine the phase angle associated with that tone. To add them together, S 0 is correlated with S 16 , the correlation coefficient is normalized and S 16 is multiplied by the normalized correlation coefficient. The same thing is done with S 0 and S 32 , S 0 and S48 and so on. Now S 0 , S 16 , . . . , S 240 are added together and this sum is correlated with S. The angle of the resulting correlation coefficient is the phase angle for that tone.
The above process is then repeated for S 1 , S 17 , S 33 , S 49 , . . . , S 241 to measure the phase angle for the second tone. This is repeated until all 16 phase angles have been measured. These phases are unwrapped and fitted to a best fit line using linear regression, as before. Yet again, the slope of the line is proportional to the delay in the signal from the RU.
No simulations have been done on the Final algorithm. However, it uses information from all eight antennas and from both sub-bands, averaging the data received before coming up with a result. As noted in the discussion about the Third Pass algorithm, improvements in measurement accuracy were obtained when data from the upper and lower sub-bands were averaged together. The Final algorithm uses eight times the amount of data as the Third Pass algorithm, thus making the measurement less susceptible to noise and multipath fading, and further improvements in measurement accuracy are expected. If processing time of the algorithm is an issue then a reduced version of the final algorithm can be used. In a reduced version, tones are processed from as many antennas as can be processed in the allotted time, with a slight reduction in the accuracy of the results.
Still another alternate embodiment applies the above described invention in the PWAN Frequency Division Duplex Communications System described in the Alamouti, Michaelson et al. patent application cited above.
Although the preferred embodiments of the invention have been described in detail above, it will be apparent to those of ordinary skill in the art that obvious modifications may be made to the invention without departing from its spirit or essence. Consequently, the preceding description should be taken as illustrative and not restrictive, and the scope of the invention should be determined in view of the following claims: | In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application 61/290,843, filed Dec. 29, 2009, and is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to gas turbine engines, and more particularly, to gas turbine engine vanes.
BACKGROUND
Gas turbine engine vanes remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
One embodiment of the present invention is a gas turbine engine. Another embodiment is a gas turbine engine vane system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engine vanes. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 schematically depicts a non-limiting example of a gas turbine engine in accordance with an embodiment of the present invention.
FIG. 2 depicts a non-limiting example of a vane assembly for a gas turbine engine in accordance with an embodiment of the present invention.
FIG. 3 depicts a non-limiting example of an inner ring, an outer ring and spokes coupling the inner and outer ring of the vane assembly of FIG. 2 .
FIG. 4 depicts a non-limiting example of an airfoil with a cooling air tube and spokes disposed in the cooling air tube of the vane assembly of FIG. 2 .
FIG. 5 is a cross-section through the airfoil depicted in FIG. 4 that illustrates a bushing and a pad that transfer loads between the airfoil and a spoke of the vane assembly of FIG. 2 .
DETAILED DESCRIPTION
For purposes of promoting an understanding of the principles of the 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 nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention.
Referring now to the drawings, and in particular, FIG. 1 , a non-limiting example of a gas turbine engine 10 in accordance with an embodiment of the present invention is schematically depicted. In one form, gas turbine engine 10 is an axial flow machine, e.g., an aircraft propulsion power plant. In other embodiments, gas turbine engine 10 may be a centrifugal flow machine or a combination axial centrifugal flow machine. It will be understood that the present invention is equally applicable to various gas turbine engine configurations, for example, including turbojet engines, turbofan engines, turboprop engines, and turboshaft engines having axial, centrifugal and/or axi-centrifugal compressors and/or turbines.
In the illustrated embodiment, gas turbine engine 10 includes an engine core 12 . Engine core 12 includes a compressor 14 having a plurality of blades and vanes 16 , and outlet guide vanes (OGV) 18 , a diffuser 20 , a combustor 22 and a turbine 24 . Diffuser 20 and combustor 22 are fluidly disposed between OGV 18 of compressor 14 and turbine 24 . Turbine 24 is drivingly coupled to compressor 14 via a shaft 26 . Although only a single spool is depicted, embodiments of the present invention are equally applicable to multi-spool engines. In various embodiments, gas turbine engine 10 may include, in addition to engine core 12 , one or more fans, additional compressors and/or additional turbines.
During the operation of gas turbine engine 10 , air is supplied to the inlet of compressor 14 . Blades and vanes 16 compress air received at the inlet of compressor 14 , and after having been compressed, the air is discharged via OGV 18 into diffuser 20 . Diffuser 20 reduces the velocity of the pressurized air from compressor 14 , and directs the pressurized air to combustor 22 . Fuel is mixed with the air and combusted in combustor 22 , and the hot gases exiting combustor 22 are directed into turbine 24 .
Turbine 24 includes a plurality of blades and vanes 28 . Blades and vanes 28 extract energy from the hot gases to generate mechanical shaft power to drive compressor 14 via shaft 26 . In one form, the hot gases exiting turbine 24 are directed into an exhaust nozzle (not shown), which provides thrust output the gas turbine engine. In other embodiments, additional turbine stages in one or more additional rotors may be employed, e.g., in multi-spool gas turbine engines, which may include turbines upstream and/or downstream of turbine 24 .
Referring now to FIGS. 2-4 , turbine 24 includes a vane assembly 30 and a static engine component 32 . In one form, vane assembly 30 is a second stage vane assembly. In other embodiments, vane assembly 30 may be a vane assembly of another turbine stage or of a compressor stage. In one form, second stage vane assembly 30 is formed of a plurality of vane packs 34 , described below, which are arranged circumferentially to form an annular gas path 36 .
Vane assembly 30 includes a plurality of circumferentially spaced composite airfoils 38 , an inner ring 40 , an outer ring 42 , a plurality of spokes 44 and a plurality of cooling air tubes 46 . Gas path 36 extends radially between inner ring 40 and outer ring 42 . Gas path 36 directs hot gases exiting the first stage turbine blades of blades and vanes 28 through composite airfoils 38 into the second stage turbine blades of blades and vanes 28 . In the depiction of FIG. 3 , composite airfoils 38 are removed for purposes of illustration.
Composite airfoils 38 are turbine vane airfoils. Composite airfoils 38 are slidably disposed between inner ring 40 and outer ring 42 . In one form, each composite airfoil 38 includes an opening 48 . Opening 48 extends through composite airfoil 38 in the span-wise direction. In other embodiments, a greater or lesser number of openings 48 may be employed in vane assembly 30 . In still other embodiments, no openings 48 may be employed. Composite airfoils 38 are formed of a composite material. In one form, the composite material is a ceramic matrix composite. Other composite materials may be employed in other embodiments, e.g., including metal matrix composites, organic matrix composites and/or carbon-carbon composites.
Inner ring 40 defines the inner wall of gas path 36 . Inner ring 40 is formed of a circumferentially arranged plurality of arcuate inner shroud segments 50 . In one form, each inner shroud segment 50 includes an opening 52 adjacent and corresponding to the opening 48 of each composite airfoil 38 in vane pack 34 . In other embodiments, a greater or lesser number of openings 52 may be employed. In still other embodiments, no openings 52 may be employed.
Inner shroud segments 50 are metallic, e.g., nickel-base superalloys. An example of a material for inner shroud segments 50 is Inconel 718. In other embodiments, inner shroud segments 50 may be formed of a nonmetallic material, such as a composite material.
Inner ring 40 is coupled to static engine component 32 via piloting features 54 . In one form, piloting features 54 may be pilot diameter arrangements. In one form, static engine component 32 is a preswirler that provides a circumferential velocity component to cooling air being supplied to second stage turbine blades (not shown) from vane assembly 30 . In other embodiments, static engine component 32 may take other forms. In still other embodiments, static engine component 32 may house or support one or more rotating engine components. In some embodiments, static engine component 32 is coupled to and supported by inner ring 40 . In some embodiments, static engine component 32 is supported and positioned by only vane assembly 30 . In some embodiments, static engine component 32 provides hoop loading via piloting features 54 to retain inner shroud segments 50 in circumferential contact and/or close circumferential proximity to each other, to maintain the circularity of inner ring 40 , and/or to provide a structural ground for spokes 44 (via inner shroud segments 50 ) to allow spokes 44 to be in a state of tension. In yet other embodiments, inner ring 40 may not be coupled to any static engine component. In some forms, inner shroud segments 50 may include interlocking features (not shown) or interface features (not shown) that interface with interlocking features (not shown) in order to provide inner ring 40 with a hoop load carrying capacity.
Outer ring 42 defines the outer wall of gas path 36 . Outer ring 42 is formed of a circumferentially arranged plurality of arcuate outer shroud segments 56 . In one form, each outer shroud segment 56 includes an opening 58 adjacent and corresponding to the opening 48 of each composite airfoil 38 in vane pack 34 . In other embodiments, a greater or lesser number of openings 58 may be employed. In still other embodiments, no openings 58 may be employed.
Outer shroud segments 56 are metallic, e.g., nickel-base superalloys. An example of a material for outer shroud segments 56 is Inconel 718. In other embodiments, outer shroud segments 56 may be formed of a nonmetallic material, such as a composite material.
Outer ring 42 is coupled to a turbine structure 60 and a turbine structure 62 , which may be, for example, turbine case structures, such as vane case structures, or first and second stage turbine blade tracks, respectively. In other embodiments, outer ring 42 may be coupled to only a single component or may be coupled to more than two components.
In one form, each vane pack 34 includes a single inner shroud segment 50 , a single outer shroud segment 56 and two composite airfoils 38 . In some embodiments, each vane pack 34 includes a single inner shroud segment 50 , a single outer shroud segment 56 and two composite airfoils 38 . In other embodiments, a greater or lesser number of airfoils 38 may be associated with each vane pack 34 . A plurality of vane packs 34 are assembled together circumferentially to yield the annular vane assembly 30 illustrated in FIG. 3 .
Spokes 44 are disposed within opening 48 each composite airfoil 38 . Spokes 44 extend between inner ring 40 and outer ring 42 , and are coupled to both inner ring 40 and outer ring 42 . In particular, spokes 44 are coupled to each inner shroud segment 50 and outer shroud segment 56 of inner ring 40 and outer ring 42 , respectively. Inner ring 40 , outer ring 42 and spokes 44 form a hub-and-spoke arrangement. Spokes 44 are operative to transfer loads between inner ring 40 and outer ring 42 , in conjunction with composite airfoils 38 . In one form, spokes 44 are pre-tensioned at assembly, i.e., pre-stressed with a tensile load. In one particular example, spokes 44 are preloaded to 80% of room temperature yield strength at assembly. In one form, there are two (2) spokes for each composite airfoil 38 . In other embodiments, a greater or lesser number of spokes 44 may be employed. In one form, spokes 44 are formed from wire. An example of a material for spokes 44 is Waspalloy, e.g., Waspalloy wire.
Cooling air tube 46 is disposed within opening 48 . In one form, cooling air tube extends through composite airfoil 38 . In another form, portions of cooling air tube 46 also extend into opening 52 of inner shroud segment 50 on one end, and extend into opening 58 of outer shroud segment 56 on the other end. Spokes 44 are disposed within and extend through cooling air tube 46 . Cooling air tube 46 is operative to transfer cooling air through second stage vane assembly 30 to static engine component 32 . In one form, cooling air tube 46 is metallic, e.g., a nickel-base superalloy. An example of a material for cooling air tube 46 is Inconel 718. In other embodiments, cooling air tube 46 may be formed of a nonmetallic material, such as a composite material. It will be understood that some embodiments may not employ a cooling air tube 46 .
Referring now to FIG. 5 , vane assembly 30 includes a plurality of bushings 64 disposed around spokes 44 and inside cooling air tube 46 . Bushings 64 are operative to transfer loads from composite airfoil 38 to spokes 44 . In one form, two (2) bushings 64 are employed at each spoke 44 . In other embodiments, a greater or lesser number of bushings 64 may be employed. In still other embodiments, vane assembly 30 may not include any bushings 64 .
Cooling air tube 46 includes pads 66 adjacent the inner surface in opening 48 of each composite airfoil 38 . Pads 66 are operative to transfer loads between composite airfoil 38 and spokes 44 (in one form, via cooling air tube 46 and bushings 64 ). In one form, each cooling air tube 46 includes three (3) pads 66 . In other embodiments, a greater or lesser number of pads 66 may be employed. In still other embodiments, cooling air tubes 46 may not include any pads 66 . In yet other embodiments, opening 48 of each composite airfoil 38 may include raised pads to transfer loads from composite airfoil 38 to spokes 44 . In some embodiments, pads 66 are compliant, e.g., in order to distribute loading on the interior surface of opening 48 of composite airfoils 38 .
During the operation of gas turbine engine 10 , cooling air is supplied to static engine component 32 via openings 58 of outer ring 42 , cooling air tubes 46 disposed within openings 48 of composite airfoils 38 , and openings 52 of inner ring 40 . In some forms, vane assembly 30 includes seals 68 ( FIG. 2 ) to prevent leakage of cooling air from opening 48 and to prevent ingress of hot gases into openings 48 , 52 and 58 . In one form, seals 68 are located in inner shroud segments 50 and outer shroud segments 56 . In other embodiments, seals 68 may be located in composite airfoils 38 or otherwise between surfaces of composite airfoils 38 and surfaces of inner shroud segments 50 and outer shroud segments 56 . In other embodiments, seals 68 may not be employed. In some embodiments, vane assembly 30 includes seals (not shown) operative to provide sealing between each adjacent pair of inner shroud segments 50 . In some embodiments, vane assembly 30 includes seals (not shown) operative to provide sealing between each adjacent pair of outer shroud segments 56 .
In some embodiments, cooling air tube 46 reduces undesirable heating of the cooling air supplied through vane assembly 30 by preventing or reducing contact of the cooling air with hot surfaces in opening 48 of composite airfoil 38 . In some embodiments, spokes 44 are kept relatively cool due to the passage of cooling air through cooling air tube 46 , which in some embodiments bathes the spokes 44 in the flow of cooling air and enhances the load-carrying capacity of spokes 44 by preventing or reducing degradation of the spoke 44 material properties that may otherwise result from operation at elevated temperatures.
Aerodynamic loading of composite airfoils 38 , e.g., in direction 70 ( FIG. 5 ), causes composite airfoils 38 to slide against inner shroud segments 50 and outer shroud segments 56 until pads 66 nest against composite airfoils 38 . Once nested, spokes 44 limit the movement of composite airfoils 38 , and aerodynamic loads on composite airfoils 38 are transferred to spokes 44 via pads 66 , cooling air tube 46 and bushings 64 . These loads are transferred to turbine structure 60 , 62 via outer ring 42 .
Loads from static engine component 32 are transferred to inner ring 40 , e.g., via piloting features 54 that couple static engine component 32 and inner ring 40 . These loads are then transferred from inner ring 40 to outer ring 42 by composite airfoils 38 in conjunction with spokes 44 , and are transferred to turbine structure 60 , 62 via outer ring 42 .
Embodiments of the present invention include vane segment for a gas turbine engine, comprising: an outer shroud; an inner shroud; a composite airfoil slidably disposed between the outer shroud and the inner shroud, the airfoil having a passage extending between the outer shroud and the inner shroud; and a spoke extending through the passage between the outer shroud and the inner shroud, wherein the spoke is operative to limit a movement of the airfoil.
In a refinement, the vane segment is structured to transfer aerodynamic loads from the airfoil to the spoke.
In another refinement, the spoke is pre-stressed at room temperature conditions with a tensile preload.
In yet another refinement, the spoke is a metal wire.
In still another refinement, the vane segment is structured to transfer loads from the inner shroud to the outer shroud via the spoke.
In yet still another refinement, the spoke is affixed to the inner shroud and to the outer shroud.
In a further refinement, the vane segment further comprises a tube disposed in the passage, wherein the spoke extends through the tube.
In yet a further refinement, the vane segment further comprises a compliant pad structured to transfer aerodynamic loads from the airfoil to the tube, and wherein the tube is structured to transfer the aerodynamic loads to the spoke.
In still a further refinement, the vane segment further comprises a second spoke extending through the passage and between the outer shroud and the inner shroud.
In yet still a further refinement, the vane segment further comprises a bushing disposed on the spoke and structured to transmit aerodynamic loads to the spoke.
Another embodiment includes a gas turbine engine, comprising: a compressor; a turbine; and a vane stage having an inner ring, an outer ring, a plurality of airfoils disposed between the inner ring and the outer ring, and a plurality of spokes extending between the inner ring and the outer ring through the plurality of airfoils, the spokes interconnecting the inner ring and the outer ring in a hub-and-spoke arrangement.
In a refinement, the gas turbine engine further comprises a vane case structure, wherein the outer ring is supported by the vane case structure.
In another refinement, the plurality of spokes are coupled to the inner ring and to the outer ring, and wherein the vane stage is structured to transfer loads from the inner ring to the vane case structure via the plurality of spokes and the outer ring.
In yet another refinement, the outer ring is formed of a plurality of vane segment outer shrouds.
In still another refinement, the inner ring is formed of a plurality of individual vane segment inner shrouds.
In yet still another refinement, the gas turbine engine further comprises an engine component supported by the inner ring, wherein the vane stage is structured to transfer loads from the engine component via the inner ring and the plurality of spokes to the outer ring.
In a further refinement, the engine component is a preswirler.
In a still further refinement, the plurality of airfoils are structured to float in a flowpath direction and transfer aerodynamic loads imposed on the plurality of airfoils to the plurality of spokes.
Embodiments also include gas turbine engine, comprising: at least one of a fan, a compressor and a turbine, wherein at least one of the fan, the compressor and the turbine includes a vane stage, the vane stage including: an inner ring; an outer ring; a plurality of airfoils slidably disposed between the inner ring and the outer ring; and means for transferring loads from the inner ring to the outer ring, wherein the means for transferring loads extends between the inner ring and the outer ring through the plurality of airfoils.
In a refinement, the means for transferring loads from the inner ring to the outer ring includes means for transferring aerodynamic loads from the plurality of airfoils to the outer ring.
In another refinement, the plurality of airfoils are composite airfoils.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary. | One embodiment of the present invention is a gas turbine engine. Another embodiment is a gas turbine engine vane system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engine vanes. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith. | 5 |
TECHNICAL FIELD
In the field of boring or penetrating the earth or other geological formation, a self-acting apparatus is disclosed having subject matter directed to exploding a charge in an inaccessible hole to propel a drill-head portion of the apparatus into the formation. Successive charges enable cyclic advance of the apparatus into the formation.
BACKGROUND ART
The long history of earth is one of vast geological tumult and change. As new continents have been formed, large land masses have broken apart or collided and combined with great pressures exerted on tectonic plates. This great pressure and movement on these tectonic plates over time has created many earthquakes and seismic fault lines to appear.
Measuring seismic waves with surface instrumentation is many centuries old. As long ago as 132 AD, Zhang Heng of China's Han dynasty invented a functional seismic detector. This was a large bronze vessel, about 2 meters in diameter. At eight positions around the top of the vessel were dragon's heads holding bronze balls. When an earthquake occurred, the internal mechanisms would react to the direction of the seismic waves and cause one of the mouths to open and drop its ball into a bronze toad at the base, making a sound and supposedly showing the direction of the earthquake.
Small movements of the earth can foreshadow larger events to follow. Typically, earth movements have been detected by a variety of sensors placed on or near the surface. Currently, electronic sensors also mounted at the surface are used to provide broadband radio-frequency detection covering a wide range of frequencies produced by earth movements. Some seismometers can measure motions with frequencies from 500 Hz to 0.00118 Hz (1/500=0.002 seconds per cycle, to 1/0.00118=850 seconds per cycle). Greater sensitivity can be obtained if underground devices directly measure earth movements and frequencies that are too weak to be detected above noise distortion at the surface.
If one looks to the history of large earthquakes over our long history on earth, it becomes alarmingly clear that the number of large quakes has drastically gone up over the last 15 years. We are living in a time of large-scale quakes, and because of overpopulation and lax earthquake-resistant building codes, significant populations live in areas where survival is influenced by earthquake dangers.
Down-hole instrumentation for seismological purposes is sometimes used by creating a borehole from the surface. For example, triaxial sensors have been employed down a borehole to measure ground motion and the potential for seismic amplification at surface structures, such as bridges. Such seismic engineering practice requires a costly and complex drilling operation to remove the earth to create multiple smooth boreholes and then lowering the instrumentation package from the surface down each such borehole to the measurement locations.
SUMMARY OF INVENTION
A device for penetrating the earth includes a hollow cylindrical housing holding a computer controller that automatically controls the device. A battery within the housing supplies power for the components. A hydraulic system within the housing has at least two arms that extend outward from the housing to engage the earth to resist movement of the housing with respect to the earth when required and to push the housing downward if needed. A drill head has a main body and a shaft. The shaft slides up and down within a shaft chamber in the housing. The main body is located below the housing. The main body is conically shaped at least at its bottom which rises from a pointed end. The main body has a base opposite the pointed end. The base has a diameter that is larger than that of the housing so that when it is propelled downward it compresses the earth to form a bore larger in diameter than the housing. A cartridge chamber within the housing holds a cartridge blank that is made to discharge an explosive charge above the shaft and propel it downward within the shaft chamber, pushing the main body into the earth below the housing. Once discharged the cartridge blank is ejected from the cartridge chamber and a new cartridge blank is inserted into the cartridge chamber from a magazine within the housing. The drill head may incorporate passages that form a pathway for rubble to flow from under the drill head to above it. When the housing is not heavy enough to sufficiently resist upward reaction thrust from a cartridge explosion or to fall downward after such explosion, then the computer activates the hydraulic system to engage the earth prior to causing the cartridge chamber to discharge the cartridge blank, or after such explosion to push the housing downward.
Technical Problem
To aid in seismological research, it would be helpful to have a simple and easy apparatus to deliver scientific earthquake sensors and other test equipment directly to these underground fault regions. Such an apparatus could deliver data useful for predicting the location and likelihood of future massive quakes or provide data for evaluation of engineered surface structures. Such an apparatus could help to save tens of millions of lives and countless billions of dollars in property damages.
Solution to Problem
The solution that will advance earthquake science research has arrived with the invention of the repetitive charge seismology unit. With the repetitive charge seismology unit, researchers can now place a whole variety of research equipment directly into these underground fault zones and key tectonic locations.
The repetitive charge seismology unit works by having a hardened metal drill head that has a conical or bullet-shaped nose slidably engaged with a hollow cylindrical housing holding computer-operated hydraulics and test equipment. A magazine within the housing holds blank cartridges with high explosives that are repetitively discharged to drive the drill head downward in increments, which compresses the surrounding earth so that a borehole larger than the housing results. As the blank cartridges are fired, the discharge propels the drill head downward a limited distance creating a hole with a diameter larger than the housing. Then, gravity and/or the hydraulics cause the housing to drop lower into the earth to follow the drill head.
After a blank cartridge is fired, the magazine automatically inserts a new blank cartridge from the magazine into the firing chamber for a repeat of the process. Each charge that explodes lowers the repetitive charge seismology unit lower into the earth. This repetitive explosion and lowering process would continue until the unit is at the desired depth along the fault line or tectonic plate.
A payload compartment in the housing holds various scientific research and other equipment, which is conveyed to the underground location for operation by the computer. The computer automatically implements the operational functions of the unit and saves and transmits the data retrieved to the surface using an antenna that employs the earth as a conduction pathway or utilizes a conduction line connected to the surface. A satellite broadcast unit may be employed to relay the data received to remote receivers.
The repetitive charge seismology unit is a beneficial technology that will give scientists the ability to place equipment throughout various underground fault lines to be able to start accurately predicting where and when our future big quakes may occur.
Advantageous Effects of Invention
The repetitive charge seismology unit will give scientists a low cost and easy way to place various research equipment underground in the fault and tectonic plate zones or simply under an engineered structure.
Researchers can place a large number of seismic-sensing equipment all along these faults. They may now be able to place new types of earthquake equipment such as pressure sensors that will measure the pressure on tectonic plate edges and junctions with known fault lines.
With the ability of the repetitive charge seismology unit to easily place this equipment underground, it will be possible to monitor plate pressure and any changes on plate pressure along fault lines. The repetitive charge seismology unit data can be relayed to satellites for transmission to far away research centers, leading to a potential to better predict possible coming quakes before any destructive seismic activity takes place.
BRIEF DESCRIPTION OF DRAWINGS
The drawings illustrate preferred embodiments of the repetitive charge seismology unit according to the disclosure. The reference numbers in the drawings are used consistently throughout. New reference numbers in FIG. 2 are given the 200 series numbers. Similarly, new reference numbers in each succeeding drawing are given a corresponding series number beginning with the figure number.
FIG. 1 is a sectional elevation view of a preferred embodiment of the device termed a repetitive charge seismology unit.
FIG. 2 is a sectional elevation view of a second preferred embodiment of the device shown in a geological setting.
FIG. 3 is a sectional top view of a magazine showing an assemblage of cartridge blanks within.
FIG. 4 is a perspective of a cartridge blank with a cut-out showing the explosive charge within.
FIG. 5 is a perspective of a tubular configuration of a housing in a preferred embodiment of the device.
FIG. 6 is an elevation view of a drill head in a preferred embodiment of the device.
DESCRIPTION OF EMBODIMENTS
In the following description, reference is made to the accompanying drawings, which form a part hereof and which illustrate several embodiments of the present invention. The drawings and the preferred embodiments of the invention are presented with the understanding that the present invention is susceptible of embodiments in many different forms and, therefore, other embodiments may be utilized and structural, and operational changes may be made, without departing from the scope of the present invention.
FIG. 1 is a sectional elevation view of a preferred embodiment of a device ( 100 ) also referred to herein as a repetitive charge seismology unit. The device ( 100 ) is for penetrating the earth ( 220 ) as an aid in seismological studies or to pursue other purposes requiring entry into the earth or other geological structure, such as regolith on the moon or other planet. In this sense, use of the term “earth” herein is meant to encompass all types of geology on Planet Earth and other bodies in the solar system.
The preferred embodiment of the device ( 100 ) includes a housing ( 105 ); a computer controller ( 135 ); a battery ( 150 ); a hydraulic system ( 155 ); a drill head ( 605 ); a cartridge blank ( 175 ); and a magazine ( 185 ) for semi-auto loading of cartridge blanks.
The housing ( 105 ) has a tubular configuration ( 505 ) because it is shaped like a pipe and is a long, hollow cylinder. The housing ( 105 ) preferably is closed off at the ends by covers or lids, which are preferably removably screwed on and off, but may also be attached in other ways.
As with a pipe of limited length, the housing ( 105 ) has an inner wall ( 110 ), an outer wall ( 115 ), a top end ( 510 ), and a bottom end ( 515 ). The housing ( 105 ) is the structure that holds or guides the components of the device ( 100 ) as it works its way into the earth ( 220 ).
The housing ( 105 ) preferably defines one or more chambers within the pipe structure. These chambers are defined in a variety of embodiments to include: a payload compartment ( 120 ) that is used to convey instruments or such other components as may be desired into the ground; a cartridge chamber ( 125 ), much like the chamber in a firearm, where the cartridge chamber ( 125 ) is used to hold and discharge a cartridge blank ( 175 ) that has an explosive charge ( 410 ); a shaft chamber ( 130 ) in fluid communication with the cartridge chamber ( 125 ), where the shaft chamber ( 130 ) holds and confines upward and downward travel of the shaft ( 170 ) of the drill head ( 605 ).
The computer controller ( 135 ) is situated within the housing ( 105 ). The computer controller ( 135 ) includes a central processing unit ( 140 ) and non-transitory computer memory ( 145 ) storing program instructions implemented by the central processing unit ( 140 ) to automatically control the device ( 100 ) once it begins its drilling operation. An antenna ( 225 ) energized by a data receiver/transmitter ( 245 ) is preferably operated by the computer controller ( 135 ) to receive instructions from the surface and convey data generated by the instruments in the payload compartment ( 120 ). Transmission signals from the device ( 100 ) are preferably propagated by conduction through the earth or via a conductor wire ( 230 ) extending from the surface ( 235 ) and fed out from a coil ( 240 ) within or attached to the housing ( 105 ). A surface transmitter ( 255 ) provides a means to send data obtained from sensors on the device ( 100 ) to a remote receiving station. The surface transmitter ( 255 ) either receives signals through the earth ( 220 ) or via the conductor wire ( 230 ). The conductor wire ( 230 ) is fed out from the coil ( 240 ) as the housing ( 105 ) sinks into the earth ( 220 ).
The battery ( 150 ) supplies power to the computer controller ( 135 ), the battery ( 150 ) is positioned within the housing ( 105 ). If a conductor wire ( 230 ) is employed, the battery ( 150 ) may be connected to a power source ( 250 ) on the surface ( 235 ).
The hydraulic system ( 155 ) is within the housing ( 105 ). The hydraulic system ( 155 ) includes at least two arms ( 160 ) that extend outward from the outer wall ( 115 ) of the housing ( 105 ) to engage the earth ( 220 ). The computer controller ( 135 ) is optionally programmed to extend the arms of the hydraulic system ( 155 ) to engage the earth ( 220 ) prior to causing the cartridge chamber ( 125 ) to discharge the cartridge blank ( 175 ). This may not be needed because the weight of the device ( 100 ) should be sufficient in most applications to avoid the need for such engagement with the earth ( 220 ) or bracing prior to detonating the explosive charge ( 410 ).
Thus, for some embodiments where the weight of the device ( 100 ) is insufficient to resist the reaction forces from the firing of the explosive charge ( 410 ), the hydraulic system ( 155 ) may be configured to resist movement of the housing ( 105 ) with respect to the earth ( 220 ) so that when the drill head ( 605 ) is pushed downward by firing the explosive charge, the housing ( 105 ) is not pushed up in reaction.
The hydraulic system ( 155 ) is preferably configured to push the housing ( 105 ) downward if gravity fails to lower it to the bottom of the hole created by the drill head ( 605 ). The hydraulic system ( 155 ) is powered by the battery ( 150 ) and controlled by the computer controller ( 135 ).
The drill head ( 605 ) includes two parts which are either integral components of a single unit, or two separate attached components. These two parts of the drill head ( 605 ) are the shaft ( 170 ) and the main body ( 165 ). The shaft ( 170 ) may be thought of as analogous to a piston in an internal combustion engine. The shaft ( 170 ) initially resides mostly within the confines of the shaft chamber ( 130 ) in an initial firing position near the cartridge chamber ( 125 ), analogous to a point near top dead center in an engine.
In a preferred embodiment, the shaft ( 170 ) is integrally constructed with the main body ( 165 ) as a single object. Whether attached or integrally formed, when the shaft ( 170 ) moves downward ( 180 ), the main body ( 165 ) of the drill head ( 605 ) pushes down in the earth and compresses the earth ( 220 ) down and to the side of the device ( 100 ). The main body ( 165 ) of the drill head ( 605 ) is forced downward ( 180 ) when the explosive charge ( 410 ) in the cartridge blank ( 175 ) is ignited. Downward movement of the drill head ( 605 ) creates space for the housing ( 105 ) to follow the drill head ( 605 ) down into the earth ( 220 ) either by action of gravity or by being pushed down by the hydraulic system ( 155 ).
In a preferred embodiment, the main body ( 165 ) is located below the bottom end ( 515 ) of the housing ( 105 ). The main body ( 165 ) includes a conical shape ( 610 ) for at least a portion of the drill head ( 605 ). The main body ( 165 ) rises from a distal pointed end ( 615 ), which is the tip of the conical shape ( 610 ), to a base ( 620 ). The base ( 620 ) has a diameter ( 625 ) extending beyond the outer wall ( 115 ) of the housing ( 105 ) so that the earth ( 220 ) is pushed away from the outer wall ( 115 ) of the housing ( 105 ).
The shaft ( 170 ) is configured to slide up and down in the shaft chamber ( 130 ) below the cartridge chamber ( 125 ). The downward movement of the shaft ( 170 ) is implemented by firing the cartridge blank ( 175 ). In the preferred embodiment of the device ( 100 ), the subsequent upward movement of the shaft ( 170 ) is implemented when gravity pulls the housing down to the main body ( 165 ) of the drill head ( 605 ).
The cartridge blank ( 175 ) includes an explosive charge ( 410 ). The cartridge blank ( 175 ) is adapted to be held within the cartridge chamber ( 125 ) for discharge of the explosive charge ( 410 ) within cartridge chamber ( 125 ). The cartridge blank ( 175 ) is similar to a blank cartridge in a firearm, except that the explosive charge ( 410 ) in the cartridge blank ( 175 ) has much greater propellant force than in a firearm.
The cartridge chamber ( 125 ) is configured: to hold the cartridge blank ( 175 ) in position to be discharged; to discharge the cartridge blank ( 175 ) upon command from the computer controller ( 135 ); and to eject the discharged cartridge blank ( 175 ) from the cartridge chamber ( 125 ). The cartridge blanks ( 175 ) are loaded similarly to the action in a semi-automatic firearm. The propulsive force from the explosion is channeled into the shaft chamber ( 130 ) where it then acts on the shaft ( 170 ), much like the piston in an automotive engine. The shaft ( 170 ) is adapted to be pushed downward ( 180 ) toward the bottom end ( 515 ) of the housing ( 105 ) upon discharge of the cartridge blank ( 175 ).
The magazine ( 185 ) is positioned within the housing ( 105 ) so that it can feed successive cartridge blanks into the cartridge chamber ( 125 ), much like a drum magazine for a firearm. The magazine ( 185 ) holds a plurality of cartridge blanks ( 305 ).
In an alternative embodiment, the drill head ( 605 ) is configured with passages ( 190 ) therethrough, said passages ( 190 ) enabling transit of rubble ( 215 ) from below the drill head ( 605 ) to above the drill head ( 605 ). This is an optional configuration because the drill head ( 605 ) is adapted to push open a hole by compacting the earth ( 220 ) around it, and not by creating pebbles or rubble ( 215 ).
In yet another alternative embodiment, the drill head ( 605 ) is further adapted to rotate like a drill bit to provide greater ability to penetrate hardened earth ( 220 ). For these embodiments, a rubble skirt ( 210 ) may be added to prevent rubble from collecting between the bottom end ( 515 ) of the housing ( 105 ) and the base ( 620 ) of the drill head ( 605 ).
The rubble skirt ( 210 ) slides down, telescopes out from the outer wall ( 115 ) of the housing ( 105 ), or telescope out from the bottom end ( 515 ) of the housing ( 105 ). The rubble skirt ( 210 ) preferably surrounds the outer wall ( 115 ) of the housing ( 105 ) and is connected to the drill head ( 605 ), preferably near the periphery of the base ( 620 ) of the drill head ( 605 ).
The above-described embodiments including the drawings are examples of the invention and merely provide illustrations of the invention. Other embodiments will be obvious to those skilled in the art. Thus, the scope of the invention is determined by the appended claims and their legal equivalents rather than by the examples given.
INDUSTRIAL APPLICABILITY
The invention has application to the drilling industry. | A device for penetrating the earth includes a hollow cylindrical housing holding a computer controller that automatically controls the device. A battery within the housing supplies power for the components. A hydraulic system within the housing engages the earth to resist movement of the housing when required and to push the housing downward if needed. A drill head shaft slides up and down within the housing. The main body of the drill head is located below the housing. The drill head has a diameter that is larger than that of the housing. A semi-auto cartridge chamber within the housing cyclically fires cartridges above the shaft to propel it downward. When the housing is not heavy enough to resist upward reaction thrust from a cartridge explosion or to fall downward following the drill head then the computer activates the hydraulic system to engage the earth. | 4 |
FIELD OF USE
[0001] This invention is in the field of devices and methods used to prevent the formation of scar tissue that often occurs as a result of a surgical procedure.
BACKGROUND OF THE INVENTION
[0002] Post-operative scar tissue formation, adhesions and blood vessel narrowing are major problems following abdominal, neurological, vascular or other types of surgery. For example, narrowing of a blood vessel at the site of an anastamosis is often caused by the unwanted proliferation of scar tissue at that location.
[0003] U.S. patent application Ser. No. 09/772,693 by R. E. Fischell, et al, filed on Jan. 1, 2001 describes various means and methods to reduce scar tissue formation resulting from a surgical procedure. However, this patent application does not describe a cytostatic anti-proliferative surgical wrap that is placed around some human tissue where there is a risk of formation of scar tissue. Although several companies have developed products (such as sheets of biodegradable mesh, gels, foams and barrier membranes of various materials) that can be placed between these structures to reduce the tissue growth, none are entirely effective.
[0004] U.S. Pat. No. 5,795,286 describes the use of a beta emitting radioisotope placed onto a sheet of material to reduce scar tissue formation by means of irradiation of the local tissue. Although radioisotopes may be effective at preventing cellular proliferation associated with adhesions, the limited shelf life and safety issues associated with radioisotopes make them less than ideal for this purpose.
[0005] Recent publications (Transcatheter Cardiovascular Therapeutics 2001 Abstracts) report a greatly reduced cellular proliferation and reduced restenosis within angioplasty injured arteries when vascular stents used for recannalization are coated with a cytostatic anti-proliferative drug such as Rapamycin (sirolmus), Actinomycin-D or Taxol. However, these drugs have never been used for reducing cellular proliferation at the site of a surgical procedure.
[0006] In U.S. Pat. No. 6,063,396, P. J. Kelleher describes the use of highly toxic, antimitotic drugs such as ricin, anthracycline, daunomycin, mitomycin C and doxorubin for reducing scar tissue formation and for wound healing. However, he makes no mention of any cytostatic anti-proliferative drug such as sirolimus or similar acting compounds.
[0007] In U.S. Pat. No. 5,981,568 Kunz et al describe the use of certain cytostatic agents that are used to inhibit or reduce restenosis of an artery that is treated from inside that artery. However, Kunz et al does not address the problem of restenosis at an anastamosis which is the surgical connection of two blood vessels. Kunz et al also fails to consider the drug sirolimus or its functional analogs as the drug to be applied for reducing cellular proliferation that can result in scar tissue formation or adhesions.
SUMMARY OF THE INVENTION
[0008] One embodiment of this invention is a device consisting of cytostatic anti-proliferative drug impregnated into, coated onto or placed onto a material sheet or mesh designed to be placed generally around human tissue that has been surgically joined or surgically treated; the goal being the prevention of formation of excess post-operative scar tissue. A drug that is impregnated into a suture or gauze-like material or sheet or coated onto the material or joined to the material by adhesion and/or capillary action is defined herein as a drug “attached” to a suture or mesh or sheet This suture, mesh or gauze onto which the drug is attached may be either a permanent implant or it may be biodegradable. The drug can be attached to an existing product such as the Johnson & Johnson SURGICEL™ absorbable hemostat gauze-like sheet or a Vicryl mesh product. With a cytostatic anti-proliferative drug such as sirolimus or its functional analogs which have a known effect on proliferating cells, the drug released from the biodegradable mesh would decrease cellular proliferation and hence be a deterrent to the formation of excess scar tissue at the surgical site.
[0009] It is also envisioned that a cytostatic anti-proliferative drug could be attached to surgical suture material. This suture/drug combination could be used (for example) to join together two blood vessels; i.e., an anastomosis, with the attached drug causing a reduction in cellular proliferation in the vicinity where the sutures penetrate through the wall of the vessel. A suture material with a cytostatic, antiproliferative drug attached that decreases scar tissue formation would also be useful for sutures in the skin, particularly for plastic surgery. A very important application would be for sutures that are required for eye surgery where reduced scar tissue formation is very much needed. It should be understood that the suture material could be either soluble or insoluble and could be used for any application for which sutures are used.
[0010] Still another embodiment of the present invention is a cytostatic anti-proliferative drug coated onto a surgical staple thus reducing scar tissue around that staple.
[0011] In addition to applying the cytostatic anti-proliferative drug at the surgical site by means of a device to which the cytostatic anti-proliferative drug is attached, it is also envisioned to apply the cytostatic anti-proliferative drug systemically by any one or more of the well known means for introducing a drug into a human subject. For example, a cytostatic anti-proliferative drug could be systemically applied by oral ingestion, by a transdermal patch, by a cream or ointment applied to the skin, by inhalation or by a suppository. Any of these methods being a systemic application of a cytostatic anti-proliferative drug. It should be understood that such a drug could be applied systemically starting at least one day prior to a surgical procedure but could be started as long as 5 days prior to a surgical procedure. Furthermore, the drug could be applied for a period of at least one day after the procedure and for some cases as long as 60 days. It should be understood that a cytostatic anti-proliferative drug could be given systemically without using any of the devices described herein. It should be understood that the cytostatic anti-proliferative drug could be given systemically in addition to the application of a cytostatic anti-proliferative drug attached to any one or more of the devices described herein. It should also be understood that an optimum result might be obtained with using one cytostatic anti-proliferative drug attached to a device with a second and/or third drug being used for systemic administration. The dose of the drug(s) would, of course, depend on the cytostatic anti-proliferative drug that was used and the characteristics of the patient such as his/her weight.
[0012] The optimal result in reducing scar tissue formation will be obtained if the cytostatic anti-proliferative drug that is used is both cytostatic and anti-inflammatory. Sirolimus and its functional analogs are therefore the ideal cytostatic anti-proliferative drugs for this application. Cytotoxic drugs such as Taxol, though they are anti-proliferative, are not nearly as efficient as cytostatic drugs such as sirolimus for reducing scar tissue formation resulting from a surgical procedure. Therefore, this invention involves only the use of cytostatic drugs that are slowly released to reduce the formation of scar tissue following a surgical procedure. These drugs are attached to devices/meshes/sheets/gels in such a way that the drugs slowly elute (for a time of at least one day) from the material onto which they are attached. In describing this invention, the use of the terms “mesh” or “sheet” or “gel” shall mean the same thing (i.e., a material to which or into which a cytostatic drug is attached) and these words will be used interchangeably. The present invention ideally utilizes those cytostatic drugs, such as sirolimus or Everolimus, that interfere with the initiation of mitosis by means of interaction with TOR protein complex formation and cyclin signaling. These drugs prevent the initiation of DNA replication by acting on cells in close proximity to the mesh from which the drug slowly elutes as very early cell cycle mitosis inhibitors that act at or before the S-phase of cellular mitosis.
[0013] Thus it is an object of this invention to have a sheet of material that can be placed into or wrapped generally around some human tissue at the site of a surgical procedure, the material having a cytostatic anti-proliferative drug attached for reducing scar tissue formation at the site of the surgical procedure.
[0014] Another object of this invention to have a sheet of material that can be wrapped around a blood vessel, a ureter, a bile duct, a fallopian tube, or any other vessel of the human body at the site of a surgically created anastamosis, the material having a cytostatic anti-proliferative drug attached to reduce scar tissue formation that can result in a narrowing of the vessel or duct at the site of anastamosis.
[0015] Still another object of this invention is to have a biodegradable sheet of material or mesh suitable for placement between body tissues including an attached drug that elutes slowly from the sheet of material to prevent cellular proliferation associated with post-surgical adhesions and/or scar tissue formation.
[0016] Still another object of the invention is to have a suture material or surgical staple to which a cytostatic anti-proliferative drug is attached.
[0017] Still another object of this invention is to have the cytostatic anti-proliferative drug be sirolimus or a functionally equivalent cytostatic and anti-inflammatory drug.
[0018] Still another object of the invention is to employ a device placed into the body of a human subject, which device has an attached cytostatic anti-proliferative drug, plus using the same or a different cytostatic anti-proliferative drug as a medication to be applied systemically to the human subject from some time prior to a surgical procedure and/or for some time after that procedure in order to reduce excessive post-surgical scar tissue formation.
[0019] These and other objects and advantages of this invention will become obvious to a person of ordinary skill in this art upon reading of the detailed description of this invention including the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 illustrates a sheet of material to which a cytostatic anti-proliferative drug has been attached; the sheet is formed so that it can be wrapped around or placed on or between human tissue at the site of a surgical procedure.
[0021] [0021]FIG. 2 is an enlargement of the cross section of a single strand of the mesh where the drug is embedded within the strand.
[0022] [0022]FIG. 3 is an enlargement of the cross section of a single strand of the mesh where the drug is coated onto the strand.
[0023] [0023]FIG. 4 is an enlargement of two strands of the mesh that have been dipped into a solution of a cytostatic anti-proliferative drug thereby attaching the drug to the strands by adhesion and capillary action.
[0024] [0024]FIG. 5 is a lateral cross section of cytostatic anti-proliferative surgical wrap placed around an end-to-end anastamosis of a vessel or duct.
[0025] [0025]FIG. 6 is a layout view of the surgical wrap of FIG. 5.
[0026] [0026]FIG. 7 is a plan view of an annular anti-proliferative sheet for application to anastamoses.
[0027] [0027]FIG. 8 is a plan view of a annular anti-proliferative sheet for application to anastamoses, the interior of the annulus having slits to facilitate placement onto a connecting blood vessel.
[0028] [0028]FIG. 9 is a cross section of cytostatic anti-proliferative surgical wrap placed at an aorta-vein graft anastamosis.
[0029] [0029]FIG. 10 is a cross section of cytostatic anti-proliferative surgical wrap placed at the anastamosis of the internal mammary artery into the side of a coronary artery.
DETAILED DESCRIPTION OF THE INVENTION
[0030] [0030]FIG. 1 shows an absorbable mesh sheet 10 with mesh strands 12 and open spaces 11 . The sheet 10 is designed to be placed post-operatively into or around human tissue at the site of a surgical procedure. When placed at the site of a surgical procedure, the sheet 10 is designed to slowly elute a cytostatic drug so as to decrease the formation of scar tissue and to reduce the extent of adhesions. When placed generally around human tissue, the mesh 10 forms a cytostatic anti-proliferative surgical wrap. The mesh strands 12 can be made from oxidized regenerated cellulose or other biodegradable materials with the cytostatic anti-proliferative drug either embedded within the strands, coated onto the outer surfaces of the strands or held onto the strands by adhesion or capillary action. Any of these possibilities will be described herein as the drug being attached to the mesh or attached to the strand of the mesh.
[0031] [0031]FIG. 2 is an enlargement of a cross section of a single strand 12 of the mesh 10 in which the cytostatic anti-proliferative drug 14 is embedded within the strand 12 .
[0032] [0032]FIG. 3 is an enlargement of the cross section of a single strand 12 of the mesh where the cytostatic anti-proliferative drug is placed into a coating 17 formed onto the exterior surface of the strand 12 . The strand 12 could be formed from either a biostable or biodegradable polymer material. The material of the coating 17 is selected so that the drug that is placed into the coating 17 will slowly elute into the human tissue at the site of a surgical procedure. To further adjust the rate of release of the drug into adjacent tissue, the coating 17 could be covered with an additional coating (not shown).
[0033] [0033]FIG. 4 is an enlargement of two adjacent strands 12 of the mesh 10 onto which a cytostatic anti-proliferative drug 18 is attached by means of adhesion and capillary action.
[0034] The anti-proliferative drugs that are less suitable for this purpose include cytotoxic cancer drugs such as Taxol, Actinomycin-D, Alkeran, Cytoxan, Leukeran, Cis-platinum, BiCNU, Adriamycin, Doxorubicin, Cerubidine, Idamycin, Mithracin, Mutamycin, Fluorouracil, Methotrexate, Thoguanine, Toxotere, Etoposide, Vincristine, Irinotecan, Hycamptin, Matulane, Vumon, Hexalin, Hydroxyurea, Gemzar, Oncovin and Etophophos. The optimum drugs for this purpose do include cytostatic drugs such as sirolimus, anti-sense to c-myc (Resten-NG), tacrolimus (FK506), Everolimus and any other analog of sirolimus including: SDZ-RAD, CCI-779, 7-epi-rapamycin, 7-thiomethyl-rapamycin, 7-epi-trimethoxyphenyl-rapamycin, 7-epi-thiomethyl-rapamycin, 7-demethoxy-rapamycin, 32-demethoxy, 2-desmethyl and proline.
[0035] Although a mesh has been discussed herein, more generally, a cytostatic anti-proliferative drug can be made to be part of any sheet of material that is or is not biodegradable, as long as the sheet of material is biocompatible. In any case, this material should gradually release the cytostatic anti-proliferative drug into the surrounding surgically injured tissue over a period from as short as a day to as long as a few months. The rate of release being controlled by the type of material into which the drug is placed. It is also envisioned that a polymer coating could be placed over the drug to slow the eluting of the drug into the surrounding tissue. Such polymer materials are well known in the field of slow release of medications, and one example is described in some detail in U.S. Pat. No. 6,143,037 by S. Goldstein et al. The effect of the cytostatic anti-proliferative drug that is attached to at least part of the sheet of material will decrease cellular proliferation and therefore decrease the formation of scar tissue and/or adhesions. Most importantly, such a mesh 10 wrapped around a vascular anastamosis would reduce the narrowing of that vessel which often occurs at the site of the anastamosis.
[0036] [0036]FIG. 5 is a cross section of a cytostatic anti-proliferative surgical wrap 21 shown wrapped around an anastamosis of a vessel or duct, the sutures 22 being used to join the cut ends of the vessel or duct. The vessel or duct can include, but is not limited to, a vein, an artery, the joining of an artificial graft to a vein or artery, a ureter, a urethra, a bile duct, an ileum, a jejunum, a duodenum, a colon or a fallopian tube. Such a wrap could be used anywhere at a site where a surgical procedure has been done. For example, the surgical site might be at the site of operations on the backbone, nerves coming out of a verterbrae, the colon or ileum, etc. A cytostatic anti-proliferative surgical wrap is defined herein as a gauze-like mesh that is wrapped generally around some human tissue at the site of a surgical procedure. The wrapping could be somewhat more or less than a full 360-degree wrap around the tissue. To accommodate tissues having different diameters, the wrap material could be sterilized in comparatively long lengths and the surgeon could it to the correct length at the time of surgery. This wrap can be sutured in place with either a conventional suture or with sutures to which a cytostatic anti-proliferative drug has been attached. FIG. 6 shows such a wrap 21 having ends 23 and 24 , which ends are typically sutured onto the vessel that has an anastamosis.
[0037] [0037]FIG. 7 shows an annular sheet 25 having a cut 26 ; the sheet 25 would have an anti-proliferative drug attached to it. The use of this sheet 25 will be explained below with the assistance of FIGS. 9 and 10. FIG. 8 shows a slit annular sheet 27 that has a cut 28 and slits 29 . This type of slit annular sheet is particularly well suited for being sutured onto the aorta at the site of an anastamosis with the sections between the slits 29 being placed and sutured onto the blood that is joined to the aorta.
[0038] [0038]FIG. 9 illustrates a typical anastamosis that occurs during coronary bypass surgery; namely, a blood vessel (typically a vein from the patient's leg) surgically joined to the aorta by sutures 31 and 32 . FIG. 9 shows the surgical wrap 21 attached to the blood vessel by means of at least one suture 35 . Also shown in FIG. 9 is an annular sheet 25 attached to the aorta by means of sutures 33 and 34 . The wrap 21 and sheet 25 would each have attached an anti-proliferative drug as described herein to prevent the formation of scar tissue within the blood vessel and within the aorta. Such an anastamosis is a frequent site where the formation of scar tissue diminishes the flow of blood through the blood vessel. By the slow release of an anti-proliferative drug attached to the wrap 21 and the sheet 25 , there will be a decreased incidence of stenosis at the site of the anastamosis. It should be understood, that either the wrap 21 or the sheet 25 , separately or together, could be used at this type of anastamosis.
[0039] [0039]FIG. 10 illustrates a typical coronary artery bypass graft of an artery or a vein to a coronary artery. FIG. 10 specifically shows an internal mammary artery surgically joined to a coronary artery such as the left anterior descending, left circumflex or right main coronary artery. To avoid the formation of scar tissue inside the anastamosis, a slit annular sheet 27 (as shown in FIG. 8) has been sutured to the coronary artery and the internal mammary artery by means of the sutures 36 , 37 , 38 and 39 . It should be understood that the wrap 21 and/or the sheet 25 could also be applied at this site. Furthermore, the surgeon could cut away some of the sheet located between the slits 29 of the sheet 27 before attaching it by sutures to the site of the anastamosis. Although FIG. 9 shows an anastamosis between the internal mammary artery and a coronary artery, any suitable vein could also be used in place of the internal mammary artery.
[0040] Another alternative embodiment of the invention is a suture material to which a cytostatic anti-proliferative drug is attached. A drawing of a highly enlarged cross section of such a suture would be shown by FIGS. 2 or 3 . That is, FIG. 2 could be considered to be a cross section of a suture 12 into which is embedded a cytostatic anti-proliferative drug 14 . FIG. 3 could be considered a highly enlarged cross section of a suture 12 that is coated with a cytostatic anti-proliferative drug 17 . FIG. 5 shows cytostatic anti-proliferative coated sutures 22 used to join a vascular anastamosis. The object of attaching a cytostatic anti-proliferative drug to a suture would be to reduce scar tissue formation where the suture penetrates through human tissue. This would be particularly true for the use a suture to join together two vessels, i.e., an anastamosis. This could be used for both soluble and insoluble suture materials. By using a suture to which a cytostatic anti-proliferative drug is attached, a surgeon would have a method for reducing scar tissue formation on the surface of the skin or anywhere else where sutures are used. A particularly valuable place for such sutures would be for eye or plastic surgery where scar tissue formation can compromise the result of a surgical procedure. Furthermore, a cytostatic anti-proliferative drug could be attached to any surgical staple that is used to join together human tissue after a surgical procedure. It should be understood that sutures or staples with a cytostatic anti-proliferative agent attached could be used for joining any tissue of a human subject where it is desired to reduce cellular proliferation, i.e., the formation of adhesions or scar tissue. It should also be understood that any of the sutures 22 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 or 39 as shown in FIGS. 5, 9 and 10 could be conventional sutures or could have a cytostatic drug as described herein attached to that suture.
[0041] When cytostatic anti-proliferative sutures are used on the skin's surface, it should be understood that an ointment that includes a cytostatic anti-proliferative agent could be applied to the skin at the site of a surgical incision. The cytostatic anti-proliferative agent would be selected from the group that includes sirolimus, anti-sense to c-myc (Resten-NG), tacrolimus (FK506), Everolimus and any other analog of sirolimus including: SDZ-RAD, CCI-779, 7-epi-rapamycin, 7-thiomethyl-rapamycin, 7-epi-trimethoxyphenyl-rapamycin, 7-epi-thiomethyl-rapamycin, 7-demethoxy-rapamycin, 32-demethoxy, 2-desmethyl and proline.
[0042] If an arterio-venus fistula shunt is placed into the arm of a dialysis patient, then the same type of cytostatic anti-proliferative agent(s) as described above could be attached to that shunt device to increase the time during which the associated vein in the arm would remain patent. Ideally, the cytostatic anti-proliferative drug could be placed throughout the inner surface of the shunt or it could be placed near the ends where the shunt attaches to the vein or to the artery.
[0043] For any of the applications described herein, the systemic application of one or more of the cytostatic anti-proliferative agents that have been described could be used conjunctively to further minimize the creation of scar tissue.
[0044] Although only the use of certain cytostatic anti-proliferative agents has been discussed herein, it should be understood that other medications could be added to the cytostatic anti-proliferative drugs to provide an improved outcome for the patients. Specifically, for applications on the skin, an antiseptic, and/or anti-biotic, and/or analgesic, and/or anti-inflammatory agent could be added to a cytostatic anti-proliferative ointment to prevent infection and/or to decrease pain. These other agents could also be applied for any other use of the cytostatic anti-proliferative drugs that are described herein. It is further understood that any human subject in whom a cytostatic anti-proliferative agent is used plus at least one of the other drugs listed above could also benefit from the systemic administration of one or more cytostatic anti-proliferative agent that has been listed herein.
[0045] Various other modifications, adaptations, and alternative designs are of course possible in light of the above teachings. Therefore, it should be understood at this time that within the scope of the appended claims, the invention can be practiced otherwise than as specifically described herein. | Disclosed is a cytostatic drug attached to a sterile sheet that is designed to be placed between internal body tissues to prevent the formation of post-operative adhesions, which adhesions are really scar tissue formation. This sheet onto or into which the drug is placed may be either a permanent implant or it may be biodegradable. By impregnating an existing product such as the Johnson & Johnson SURGICEL™ absorbable hemostat gauze-like sheet with an anti-proliferative drug such as sirolimus, the biodegradable, drug impregnated mesh would act as a barrier to cell proliferation and hence be a deterrent to the formation of adhesions or scar tissue. Another embodiment of this invention is a cytostatic drug attached to a sheet that is placed at the site of an anastamosis to decrease scar tissue formation from within the vessel at the site of the anastomosis. | 0 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to integrated circuit device design, and more particularly to integrated circuit design techniques to mitigate on-chip noise of such device.
2. Description of Related Art
Improvements in manufacturing processes are enabling integrated circuit devices to offer more functionality as the size of individual transistors contained therein get smaller and smaller, thus allowing more transistors to be packaged within an integrated circuit device. As the trend of integrating more functions in a single high performance integrated circuit device (also called a chip) continues, the on-chip noise condition due to switching activity on the chip has become a major new challenge. In addition, as the power density increases with each technology generation (for example, 0.25 micron line widths, 0.18 micron line widths, 0.13 micron line widths, etc.), it becomes increasingly difficult to provide adequate power distribution when the power grid structure is shrinking at a similar rate to that of the power consuming gates/transistors. High frequency noise is impeding the desired increase in clock cycle time and improved reliability for these highly integrated systems on a chip. In order to optimally mitigate the noise impact, a systematic chip-wide approach is needed since the worst conditions anywhere on the chip will become the ultimate limiter or bottleneck.
Today, a highly integrated chip typically contains greater than 100,000 placeable objects or macros. In order to analyze and optimize the interaction between these objects/macros, a computer database with reduced memory usage and a highly efficient algorithm is needed.
SUMMARY OF THE INVENTION
An improved method and system for integrated circuit device physical design and layout. The physical layout of the integrated circuit device is optimally stored in a database to provide improved analysis capabilities of the integrated circuit device's characteristics. The method and system evaluates local interactions between functional blocks and decoupling cells on a given floor plan of a chip using this optimized database in order to reduce memory and processor utilization. Local noise is projected by using dI/dt and capacitance estimates. Areas of highest noise concern are identified, and floorplan mitigation actions are taken by tuning the placement of neighboring decoupling cells and their properties. Upon several iterative cycles, a near optimal solution for a given floorplan of the total chip is achieved.
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 depicts the overall design flow for on-chip noise mitigation of an integrated circuit device.
FIG. 2 depicts a representative chip floor plan broken up into a matrix of smaller blocks.
FIG. 3 depicts two neighboring macros and their respective logical boundary boxes.
FIG. 4 depicts three neighboring macros and their respective logical boundary boxes.
FIG. 5 depicts three neighboring macros and a plurality of decoupling capacitor (decap) cells.
FIG. 6 depicts three neighboring macros and their associated initial logical boundary boxes.
FIG. 7 depicts three neighboring macros and their associated logical boundary boxes after an initial tuning to account for projected noise.
FIG. 8 depicts three neighboring macros and their associated logical boundary boxes after final tuning to account for projected noise.
FIG. 9 depicts decap cells identified for replacement to a different type of decap cell.
FIG. 10 depicts an equivalent circuit RLC grid used for simulating macro and decap cell characteristics.
FIG. 11 depicts simulated on-chip noise for a given macro size/power as a function of boundary box radial distance from the macro and the added on-chip decap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The method and procedure for improving noise characteristics of an integrated circuit device is shown generally at 100 in FIG. 1 . The database is initialized at 102 with initial information, including chip level floor plan information such as size and position of all objects, macro specific data such as current signature and intrinsic capacitance of the macro, and decoupling capacitor (decap) properties such as capacitance and response time. Using the above described initial database information, the intrinsic noise level for the device is projected at 104 . Each macro for the chip is given an initial expansion/boundary box size at 106 . The expansion/boundary box is a variable-sized, logical perimeter around the physical macro, as will be further described below. Database 108 is used to evaluate the total capacitance for each boundary box at 110 . In similar fashion to the initial noise analysis done at 104 , the noise for each boundary box and its associated capacitance is projected at 112 . The size of each boundary box is then tuned at 114 , depending upon whether the associated noise is above or below a noise threshold. For example, for macros having projected noise above the noise threshold, the associated boundary box is made bigger. For macros having projected noise below the noise threshold, the associated boundary box is made smaller. The updated database 108 is again used to evaluate total capacitance for each boundary box at 110 , and to project noise for the macro within each expansion at 112 . This process iteratively loops for forty times in the preferred embodiment. Once the boundary box sizes have been finally sized based on such iteratively looping, a fine tuning of decoupling capacitor properties is performed at 116 , where decap cells having different properties are swapped into local areas still having projected excessive noise. The database is updated accordingly at 108 , capacitance evaluated at 110 , and noise projections are again determined at 112 . This fine tuning by decap cell swapping then repeats for one or two more iterations in the preferred embodiment, finally resulting in a final database at 118 , where the process then exits at 120 . Many of these internal processes will now be described in more detail.
Database 102
There are currently more than 60,000 macros and 300,000 decoupling capacitors (decaps) on a typical processor or system-on-a-chip (SOC) integrated circuit device. This represents a very large data set which grows with each new generation of technology. In order to deal with such large volume of data, memory usage becomes a critical aspect of an optimization process for the whole chip/device. Cells sharing common information are grouped together and indexed. A single copy of the common information is stored in memory, in a hash table for fast lookup, with each cell associated with an index identifier.
The principal algorithm uses a procedure to find all cells (macros and decaps) that fall in, or partially in, a given boundary box. Since this procedure is frequently used, the database is optimized to reduce search time. In order to avoid searching every cell, the chip is broken up into a matrix of smaller blocks. Cells or pointers of cells are stored in the matrix at location(s) where they belong. This way, cells are searched only if they are stored in matrix locations covered by the particular boundary box.
For example, as shown in FIG. 2 , there is shown a representative chip floor plan 101 containing eight cells 111 , 113 , 115 , 117 , 119 , 121 , 123 and 125 . This chip floor plan is shown being broken up into an M row by N column matrix 103 , in this case M=5 and N=6. Other matrix sizes are also possible. Cells or pointers of cells are stored in the matrix 103 at location(s) where they belong. For example, cell 117 is stored in Matrix (2,2) since it is fully contained within that matrix location. Cell 121 is stored in Matrix (1,3) and Matrix (1,4) since it spans across two matrix locations.
Similarly, cell 119 is stored in Matrix (2,3), Matrix (2,4), Matrix (2,5), Matrix (3,3), Matrix (3,4) and Matrix (3,5) as it spans these matrix locations. The other remaining cells 111 , 113 , 115 , 123 and 125 are similarly stored in the matrix 103 at location(s) where they belong. In order to find all cells that are within, or overlap, a boundary box such as 127 , only matrix locations covered by the particular boundary box need to be searched. With the example shown in FIG. 2 , in order to find all cells that overlap boundary box 127 , only the matrix locations Matrix (3,3), Matrix (3,4), Matrix (4,3) and Matrix (4,4) need to be searched to locate the cell or cell pointer information.
Evaluate Macro Intrinsic Capacitance in a Given Boundary Box (Step 110 )
The intrinsic capacitance associated with a given block (e.g. Macro A shown in FIG. 3 ) is part of the total capacitance which counteracts the dI/dt noise induced by its switching activity. This capacitance contains two components—(1) the self quiet capacitance related to non-switching parts of the circuits in Macro A, and (2) parts of a neighboring block (e.g. Macro B shown in FIG. 3 ) provided such neighboring block falls within a range of interaction defined by a given boundary box around Macro A. However, if a macro (or portions of a macro) is included in another macro's boundary box, its intrinsic capacitance is shared with the other macro. For example, with reference to FIG. 3 , see Macro A at 120 and Macro B at 122 . Part of Macro A is within Macro B's boundary box 126 , as shown by cross-hatched area S 2 . Therefore, the capacitance in area S 2 is shared by both Macro A and Macro B. In similar fashion, part of Macro B is within Macro A's boundary box 124 , as shown by cross-hatched area S 1 . The capacitance in area S 1 is also shared by both Macro A and Macro B.
Referring now to FIG. 4 , there is shown an additional Macro C at 128 and having a boundary box 130 . It can be seen that part of Macro A is within Macro C's boundary box 130 , as shown by cross-hatched area S 3 . Also, part of Macro C is within Macro A's boundary box 124 , as shown by cross-hatched area S 4 . Now, part of area S 2 is shared by both Macro B and Macro C at 132 , so the union of areas S 2 and S 3 are shared by all three Macros A, B and C. On the other hand, Macro A's boundary box covers part of Macro B (at S 1 ) and Macro C (at S 4 ), so Macro B and C share part of their capacitance with Macro A as well. The effective (after sharing) intrinsic capacitance of Macro A equals the original (without sharing) capacitance of Macro A plus the sharing of capacitance under area S 1 and S 4 , less the sharing of area S 2 and S 3 . As can be appreciated, the problem becomes more complicated as the sharing involves more macros.
For the general case, assume that for every macro, there are M macros sharing all or part of its intrinsic capacitance. To calculate one macro's effective capacitance, the complexity is M*M. Assuming that there are a total of N macros on the chip, the complexity is M*M*N, if all N macros are evaluated macro by macro. To reduce the complexity, a different approach is taken. An example will now be shown for three macros. The effective capacitance of each macro is defined as follows:
Effective Capacitance ( A )=original capacitance ( A )−sharing of A ( S 2 , S 3 )+sharing of B ( S 1 )+sharing of C ( S 4 )
Effective Capacitance ( B )=Original capacitance ( B )−sharing of B ( S 1 )+sharing of A ( S 2 )
Effective Capacitance ( C )=Original capacitance ( C )−sharing of C ( S 4 )+sharing of A ( S 3 )
If we just evaluate Macro A, the value of the following parameters are known: (i) original capacitance (A); (ii) sharing of A(S 2 , S 3 ); (iii) sharing of A(S 2 ); and (iv) sharing of A(S 3 ). Sharing of A(S 2 , S 3 ) can be distributed to Macro B and C when A is evaluated, so that we have the following when evaluating Macro A:
Effective Capacitance ( A )=Original capacitance ( A )−sharing of A ( S 2 , S 3 )
Effective Capacitance ( B )=+sharing of A ( S 2 )
Effective Capacitance ( C )=+sharing of A ( S 3 )
When evaluating Macro B, we distribute the sharing of B(S 1 ) to Macro A, resulting in the following when evaluating Macro B:
Effective Capacitance ( A )=Original capacitance ( A )−sharing of A ( S 2 , S 1 )+sharing of B ( S 1 )
Effective Capacitance ( B )=Original capacitance ( B )−sharing of B ( S 1 )+sharing of A ( S 2 )
Effective Capacitance ( C )=+sharing of A ( S 3 )
When evaluating Macro C, the result is:
Effective Capacitance ( A )=Original capacitance ( A )−sharing of A ( S 2 , S 3 )+sharing of B ( S 1 )+sharing of C ( S 4 )
Effective Capacitance ( B )=Original capacitance ( B )−sharing of B ( S 1 )+sharing of A ( S 2 )
Effective Capacitance ( C )=Original capacitance ( C )−sharing of C ( S 4 )+sharing of A ( S 3 )
As can be seen, the complexity has been reduced to M*N.
Tuning the Boundary Box Radius (Step 114 )
For noise reduction, decoupling capacitor cells are generally added to the placed macros, as shown by elements 134 in FIG. 5 . Hence, these are also contained within a boundary box as indicated in FIG. 6 . The quiet capacitance available to counteract the noise of any given macro is dependent on the size of the boundary box assigned to this given macro. Since these boundary boxes in a typical dense design are overlapping with each other, the size of each boundary box needs to be tuned for the respective macro, such that the capacitance in the boundary box is just sufficient to meet its noise target. As one macro's boundary box shrinks, some decoupling capacitance is freed up for other macros, and in turn has a ripple affect on all macros' boundary box sizes. To effectively solve this multi-body problem, a method of trial and error is employed. A solution is typically reached in less than forty iterations in the preferred embodiment.
An example of this process will now be described. Referring again to FIG. 5 , there is shown a chip having three macros and ninety-nine decap cells. Each macro 120 , 122 and 128 is initially assigned an initial boundary box size based on its noise projection, as depicted by boundary boxes 124 , 126 and 130 in FIG. 6 . For purposes of this example, decap cells in the overlap region of bounding boxes 124 and 130 are regarded as being shared equally between macros There are ten decaps for Macro A, six decaps for Macro B, and forty four decaps for Macro C. Using this information, the noise for each macro is projected again. If a macro's newly projected noise level is below its target, its boundary box is decreased to free up unneeded decaps. If a macro's newly projected noise level is above its target, its boundary box is increased to capture more decaps. The possible range of the boundary box size depends on power grid and decap response time, and is typically zero to five hundred microns in the preferred embodiment. Assume the noise of Macro A and B are above the noise target, meaning they need more decap cells, and the projected noise of Macro C is under the noise target, so that it can free some decaps by shrinking its boundary box size. After the boundary box sizes have been adjusted accordingly, Macro A has twenty three decaps, Macro B has fifteen decaps, and Macro C has nine decaps, as shown in FIG. 7 . The noise projection is then repeated, and the boundary box sizes for the macros are re-tuned When the final solution is reached (in the preferred embodiment, after forty iterations), as shown in FIG. 8 , those macros with maximum boundary box sizes (given by the hard distance limit), are considered as failing to meet set noise targets, whereas all other macros are within the noise limit.
Improvement of Noise Reduction
Once areas on the chip are identified where the macros fail set noise targets, several different steps can be taken. Different approaches are needed depending on the status of the chip design. Early in the design cycle, floor plan changes (e.g. spacing out macros in those problem areas identified above) are preferred. In the later stages of the design, basic changes of the floor plan will have a more significant impact on schedule and hence a less intrusive approach is desired.
The particular technology being used for the IC chip can provide several types of decoupling capacitors which may differ, for example, in their capacitance density or response behavior. Exchanging capacitance types in critical areas (e.g. replace thick oxide cap with thin oxide cap, deep-trench caps, or active caps) near these macros can dramatically improve the local noise problem. However, the use of these high performance caps typically come at a higher cost, such as design complexity, more leakage current or lower device yield, such that only a limited amount of usage of these high performance caps is acceptable. Therefore, these are placed at strategic places where they will be most effective. For example, as shown in FIG. 9 , some decap cells in the Macro A boundary box 124 need to be replaced (since Macro A and B are failing their noise targets in this example). Replacing decap cells in circled area 140 is the most effective because they are shared by two macros that are both having noise problems. Decap cells in circled area 142 are a secondary choice for replacement because they are shared by Macro A and Macro B. Although Macro C met its noise target, it is always better to have less noise. In addition, the added capacitance introduced by the replaced decap cells may allow further shrinkage the Macro C boundary box, which in turn would free up more decaps which can then be used to reduce the noise of Macro A and/or Macro B.
Noise Projection (Given Macro ac Power, Dimension, Decaps) 112
To quantify the noise created by a macro—which is used for the initial noise projection and the noise projection after adding decap, a detailed equivalent model of the on-chip power distribution grid is extracted and simulated. In today's high performance digital integrated circuits, the power distribution network is set up as multilayer grids. In such a grid, and on each layer, straight vdd/gnd intedigitated lines (which are orthogonal to lines in adjacent layers) run the length of the chip and connect to the appropriate vdd/gnd lines above/below it through vias. This physical structure is input into a R,L,G,C extraction tool and an equivalent resistance/unit length, inductance/unit length and capacitance/unit length of the mesh is extracted for each of the orthogonal directions.
Using these extracted parameters, an equivalent circuit simulation deck is setup, as shown in FIG. 10 . On this RLC grid, whose granularity can be determined by the detail required, the equivalent circuit elements for the switching macro 152 and intrinsic/added cap 154 are hooked at the appropriate nodes. This setup is then simulated and the peak noise and time of occurrence is stored. The sensitivity of the noise created is simulated as a function of (i) macro power, (ii) macro size, and (iii) added decap. These parameters are varied one parameter at a time during simulation, and the results are stored for subsequent use in noise projections. For example, as shown in FIG. 11 , each curve depicts the on-chip noise as a function of boundary box radial distance from the source (from zero to the maximum bounding box) for a given macro size, power and on-chip decap. The family of curves is for different added on-chip decoupling capacitance (the parameter being varied). The top most curve represents the macro's original intrinsic capacitance, with each subsequent curve depicting projected noise for increasingly added decap.
It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system.
The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | An improved method and system for integrated circuit device physical design and layout. The physical layout of the integrated circuit device is optimally stored in a database to provide improved analysis capabilities of the integrated circuit device's characteristics. The method and system evaluates local interactions between functional blocks and decoupling cells on a given floor plan of a chip using this optimized database in order to reduce memory and processor utilization. Local noise is projected by using dI/dt and capacitance estimates. Areas of highest noise concern are identified, and floor plan mitigation actions are taken by tuning the placement of neighboring decoupling cells and their properties. Upon several iterative cycles, a near optimal solution for a given floor plan of the total chip is achieved. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to an hydraulic distributor of the kind used in hydraulic systems for controlling, for example, hydraulic motors or jacks.
Such an hydraulic distributor has a distributing slide that is movable through several positions. This distributor is described as the proportional type when, for a given displacement of the slide, a given constant output is obtained in the operating circuits independent of the conditions of force or couple encountered by the receiver, jack, or similar equipment. Such a proportional hydraulic distributor is disclosed, for example, in the application for French Pat. No. 84 06 747, made by the present Applicant on the 18th Apr., 1984 under the title: "Hydraulic Distributor of the Proportional Type with Sensing of the Highest Pressures in the Operating Circuits." U.S. patent application Ser. No. 724,523 corresponds to such application for French patent. Besides the main distributing slide, an hydraulic distributor according to the present invention includes a pressure compensating slide which moves against a compression spring in a bore provided with annular operating channels, each one is connected to various branches of the hydraulic circuit.
In practice, it will be seen that, even if the position of the compensating slide is established at any moment in time by an equilibrium between the return force of the spring and the forces due to pressures which are applied to it at each of its ends, parasitic phenomena occur in dynamic operation which harm the stability of the control. These parasitic phenomena are due essentially to the appearance of a force of hydrodynamic drag, which is connected with the instantaneous characteristics of the flow, and which acts on the compensating slide with an intensity proportional to the variation in the quantity of movement between the upflow and downflow portions of the flow within the slide.
SUMMARY OF THE INVENTION
The present invention has the object of avoiding the stability disadvantages of a prior art hydraulic distributor that has a compensating slide by automatically creating, through a system of assistance, a force that is equal and in opposite direction to the force of hydrodynamic drag, so that the latter has no influence on the instantaneous position of equilibrium of the compensating slide.
A compensating slide for an hydraulic distributor according to the present invention has a cylindrical body sliding in a bore in the stator along which are placed distribution grooves. In such an hydraulic distributor the cylindrical body is hollow, and it has drilled apertures in it which slide with it opposite the distribution grooves to place the distribution grooves as required in communication with its internal space. The internal space of the cylindrical body opens at one end on a seat which is provided in the body of the slide, and on which the end of a blocking piston can come to bear. The blocking piston has a return spring which tends to press against the seat, the seat also being surrounded by an assistance chamber in the stator. According to another feature of the invention, the stator chamber surrounds the front end of the compensating piston, and the central port of the piston slides in a bore in the stator and forms a seal therein, while the rear part of the piston is surrounded by a chamber in which the pressure is in permanent communication with the operating pressure of the slide.
According to another feature of the invention, one of the stator grooves is connected to the input pressure, and it communicates with the assistance chamber through a choke.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached drawings, given by way of non-limiting example, will allow the features of the invention to be better understood.
FIG. 1 is a diagrammatic sectional view showing the assembly of a proportional hydraulic distributor of the known type;
FIG. 2 is a graph showing the result of the strength of the hydrodynamic drag on the quality of regulation of the output of an apparatus with a pressure compensator; and
FIG. 3 is a view of a portion of the proportional hydraulic distributor of FIG. 1 which has been modified according to the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
There is shown in FIG. 1 a proportional hydraulic distributor, identified generally by reference numeral 10, of the type disclosed by the application for a French Pat. No. 84 06 747 made in the name of the present Applicant on the Apr. 18th 1984 under the title: "Hydraulic Distributor of the Proportional Type with Sensing of the Highest Pressures in the Operating Circuits," corresponding to U.S. patent application Ser. No. 724,523.
The proportional hydraulic distributor 10 has a stator 1 and a main distributing slide 3 which is movable within the stator 1. The stator 1 includes a groove 35 which communicates with a first operating channel 13, a groove 36 which communicates with the return circuit, a groove 38 which communicates with a second operating channel 14 and a groove 39 which is connected to the return circuit. The main distributing slide is movable within the stator 1 across the grooves 35, 36, 38 and 39.
An annular chamber 27 surrounds the central port of the distributing slide 3. Two annular chambers 42 and 45 in the stator 1, located at the ends of the main distributing slide 3, are connected by a channel 46 for the detection of the operating pressure. The channel 46 communicates permanently with a chamber 18 in a spring 17 that is provided to return a compensating slide 16.
Experience shows that in the dynamic phase of the operation of the proportional hydraulic distributor 10, that is to say during the phases when the compensating slide 16 is in movement, the movement of the compensating slide 16 is influenced by the force of hydrodynamic drag, which harms the quality of the control of the output of the proportional hydraulic distributor. In particular, if the variations in the hydraulic output Q as a function of the difference Pe-Pu, where Pe is the entry pressure, and Pu is the pressure upflow of a choke in the section of the main distributing slide, are traced on a diagram, the results shown in FIG. 2 are obtained. It will be seen that the output Q, instead of remaining constant, decreases as the value Pe-Pu increases.
The present invention is intended to avoid the decrease in output Q as the value Pe-Pu increases, and it does so by replacing the compensating slide 16 in FIG. 1 by the construction illustrated in FIG. 3, in which the effects of the force of hydrodynamic drag are automatically compensated and cancelled.
As illustrated in FIG. 3, the compensating slide according to the invention is identified generally by reference numeral 100 and has a hollow tubular body 101 sliding in the stator 1 opposite the grooves 102 (in which the entry pressure Pe is present) and 103 (in which the pressure Pu is present upflow of an operating choke 104). Drilled holes 105 and 106 extend through the wall of the tubular body 101 to open into an internal space 107. The tubular body 101 carriers a tapered seat 108 at one of its ends, and the front end of a sliding piston 109 can come to bear on the tapered seat 108 under the return thrust of a spring 110, which also bears against a plug 111 fixed in the stator 1.
At the front end of the sliding piston 109, near to the tapered seat 108, the hollow tubular body 101 of the compensating slide 100 is surrounded by an assistance chamber 112, in which a pressure Pas is present. The assistance chamber 112 communicates with the groove 102 through a choke 113. The pressure Pas located downflow of the choke 113 may, therefore, differ from the pressure Pe in the groove 102.
The operation of the hydraulic distributor of the present invention is as follows:
When the hollow tubular body 101 of the compensating slide 100 moves in the stator 1 in front of the grooves 102 and 103, it allows the fluid to pass through the internal space 107 to continue towards the operating choke 104 which controls the output, as shown by the arrows. The external diameter of the sliding piston 109 bears against the tapered seat 108 in the hollow tubular body 101. The sliding piston 109 is thrust against the tapered seat of the hollow tubular body 101 by the spring 110. The assistance chamber 112 is fed from the pressure in the groove 102 through the choke 113.
When the sliding piston 109 bears on the tapered seat of the hollow tubular body 101, it interrupts the connection between the assistance chamber 112 and the pressure Pu in the groove 103 and in the internal space 107. The pressure in the assistance chamber 112 can then increase, and approach the value Pe in the groove 102, but its increase will be limited when it gives rise to a force equal and opposite to that of the force of the hydrodynamic drag on the annular section formed between the body of the hollow tubular body 101 and the sliding piston 109. Thus, the assistance pressure is a function of the force of the hydrodynamic drag. The automatic operation is obtained as a result of the laws which govern the balance of force on the sliding piston 109 and the hollow tubular body 101 which functions as a slide member in the compensating slide 100. In fact, the position of the sliding piston 109 is determined by the difference in pressure, Pu-Pui, the pressure Pui representing the pressure downflow of the operating choke 104.
If the difference in pressure, Pu-Pui, increases, the sliding piston 109 moves compressing the spring 110; the hollow tubular body 101 of the compensating slide 100 follows the sliding piston 109 and reduces the connection between the grooves 102 and 103. Because of this, the movement of the hollow tubular body 101 causes a reduction of pressure in the groove 103, so that the sliding piston 109 assumes a new position of balance.
If the difference in pressure Pu-Pui decreases, the sliding piston 109 is pressed by the spring 110 against the hollow tubular body 101 of the compensating slide 100, which moves and increases the connection between the grooves 102 and 103. Because of this, the pressure Pu increases, and the sliding piston 109 assumes another new position of balance.
According to another feature of the present invention, the rear of the sliding piston 109 as well as the spring 110 is surrounded by a chamber 114 and a channel 115 keeps the chamber 114 connected to the hydraulic circuit downflow of the operating choke 104 where the pressure Pui obtains.
Although the best mode contemplated by the inventor for carrying out the present invention as of the filing date hereof has been shown and described herein, it will be apparent to those skilled in the art that suitable modifications, variations and equivalents may be made without departing from the scope of the invention, such scope being limited solely by the terms of the following claims. | A proportional hydraulic distributor with a hollow, cylindrical compensating slide, a seat at one end of the compensating slide, a reciprocable piston, an end of which is urged against the seat by a spring, a pressure assistance chamber surrounding the seat, and a choke connecting the entry pressure of the hydraulic distributor to the pressure assistance chamber. The balance of forces on the reciprocable piston and on the cylindrical compensating slide is equal to and oppositely directed with respect to the hydrodynamic drag force that develops during transitional phases of the operation of the hydraulic distributor. | 8 |
This application claims the benefit of our provisional application No. 60/414,327 filed Sep. 30, 2002 which is relied and incorporated herein by reference.
INTRODUCTION
The present invention relates to specific aqueous hydrogen peroxide solutions that are characterized by a maximum amount of alkali metals, alkaline earth metals, and amines having a pk B of less than 4.5, and that are particularly suitable for use in processes for the epoxidation of olefins. In another aspect, the present invention relates to a process for the preparation of such an aqueous hydrogen peroxide solution.
BACKGROUND OF THE INVENTION
Today, the vast majority of hydrogen peroxide is produced by the well-known anthraquinone process. A survey of the anthraquinone process and its numerous modifications is given in G. Goor, J. Glenneberg, S. Jacobi: “Hydrogen Peroxide” Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, 6 th ed. Wiley-VCH, Weinheim June 2000, page 14. Generally, the anthraquinone loop process comprises the following steps:
(a) Hydrogenation of a working solution comprising an organic solvent or mixture of organic solvents, and one or more active anthraquinone compounds;
(b) oxidation of the resulting hydrogenated working solution to form hydrogen peroxide;
(c) extraction of hydrogen peroxide with water;
(d) stabilizing of the extracted aqueous hydrogen peroxide solution;
(e) drying of the working solution after extraction; and
(f) regeneration and purification of the working solution.
For each of the above distinct process steps, the Ullmann reference discloses numerous different possibilities.
Crude hydrogen peroxide solutions or concentrated hydrogen peroxide solutions obtained from the anthraquinone process contain a plurality of compounds in addition to hydrogen peroxide in low concentrations. These compounds are either impurities or additives like stabilizers. The impurities are compounds that are extracted from the working solution into the aqueous phase. They are mainly ionic or polar species like carboxylic acids, alcohols, carbonyl compounds and amines. These impurities are therefore also found in commercial hydrogen peroxide solutions.
For example, hydroquinone solvents that are commonly used in the above described process are nitrogen containing compounds like amides and ureas (see Ullmann supra page 6). Particularly preferred are tetraalkyl ureas like tetrabutyl urea. The use of these solvents result in amine impurities like monoalkyl or dialkyl, especially monobutyl and dibutyl, amines in the final hydrogen peroxide solutions. For example, the commercial hydrogen peroxide solution HYPROX® available from Degussa AG contains up to 200 wppm mono- and dibutyl amine based on the weight of hydrogen peroxide.
Depending on the final use of the hydrogen peroxide solutions, it is also known to conduct additional purification steps in order to obtain the required specification for the respective use of the hydrogen peroxide solution.
For example, DE-A 100 26 363 discloses a purification process for aqueous hydrogen peroxide solutions, whereby the solutions are treated with an anion exchange resin, a nonionic absorbing resin having a specific structure, and a neutral absorbing resin also having a specific macroporous structure. The hydrogen peroxide solutions obtained in this way are substantially free of cationic, anionic and organic impurities. Therefore, the solutions are particularly useful in microelectronics applications.
Similarly U.S. Pat. No. 4,999,179 discloses a process for purification of hydrogen peroxide solutions that contain, after purification, each metal cation in an amount of less than 5 ppb, each anion in an amount of less than 10 ppb and organic impurities in an amount of not more than 5 ppm in terms of total organic carbon content.
The drawback of such methods is that the purification is extremely expensive and can therefore, for economic reasons, not be used for the preparation of chemical mass products like propylene oxide. Furthermore, such highly purified hydrogen peroxide solutions are substantially free of anionic components like phosphates and nitrates that are necessary for the stabilization of aqueous—especially highly concentrated—hydrogen peroxide solutions for safety reasons.
From EP-A 100 119, it is known that propene can be converted by hydrogen peroxide into propene oxide if a titanium-containing zeolite is used as catalyst.
Since then, many investigations with respect to the effect of the addition of basic, acidic and ionic compounds either during preparation of the titanium silicalite catalyst or their presence in the reaction mixture on the activity and selectivity of the catalysts have been published.
From EP-A 230 949, it is known to neutralize the titanium silicalite catalyst either prior to its use in an epoxidation reaction or in situ with strong bases thereby introducing large amounts of alkali metal or alkaline earth metal ions into the reaction mixture. Said neutralization resulted in an increase in activity and selectivity to the desired olefin oxide in a batch process.
The experiments in EP-A 757 043, however, show that in a continuous process the activity is considerably reduced if the catalyst is neutralized prior to or during the reaction. Therefore, it is suggested to treat the catalyst prior to or during the epoxidation reaction with a neutral or acidic salt. The experimental data in EP-A 757 043 confirm that by addition of neutral or acidic salts the selectivity is increased but the activity is less reduced compared to the addition of a base. But EP-A 757 043 only shows examples wherein the catalyst is treated with the salt prior to the reaction and the catalyst is used in slurry form. Additionally, the experiments were only run for 8 hours but nevertheless show a dramatic drop in catalyst activity only after 4 hours, which is by no means acceptable for an industrial process.
Similarly, EP-A 712 852 teaches that by performing an epoxidation process catalyzed by titanium silicalite in the presence of a non-basic salt the selectivity is increased. All the examples are run in batch operation mode with a stirred catalyst slurry for one hour. Although it can be confirmed that the presence of non-basic salts may have a positive influence on catalyst selectivity in a short term experiment, it was discovered that even if non-basic salts are present in a reaction mixture for a continuous epoxidation reaction the activity and selectivity drops dramatically over time. Thus, the teaching of EP-A 712 852 does not lead to a reaction system that can be economically employed in a continuous epoxidation process using hydrogen peroxide in the presence of a heterogeneous catalyst.
In WO 00/76989, the influence of ionic components in commercially available aqueous hydrogen peroxide solutions that are used in epoxidation reactions as described in the above prior art documents is discussed. Ionic components, especially phosphates and nitrates, are added to commercially available aqueous hydrogen peroxide solutions as stabilizers to reduce hazardous decomposition of hydrogen peroxide. Contrary to the disclosure in the above prior art documents, WO 00/76989 teaches that the presence of ionic components in the reaction mixture—even those that have been added as stabilizers to commercial hydrogen peroxide—is detrimental to the long term selectivity in a continuous titanium silicalite catalyzed epoxidation reaction and should therefore be reduced to a minimum.
Contrary to the above prior art documents, continuous reactions running up to 300 hours were conducted showing that if ionic components are present in an amount of more than 100 ppm the long term selectivity is reduced. To solve this problem, it is suggested to remove ionic componenets from hydrogen peroxide solutions prior to use in epoxidation reactions by means of ion exchangers. Moreover, WO 00/76989 teaches that ammonium compounds and ammonia should be avoided under any circumstances since these compounds may lead to undesired side products by oxirane ring opening reactions with the formed olefin oxide. Although the teaching in WO 00/76989 leads to some improvement in long term selectivity compared to the above art, this improvement is still insufficient for an industrial scale process. Furthermore, this improvement can only be achieved with the complicated and, both in terms of investment and process costs, economically undesirable additional process step of ion exchange. Last but not least, removal of stabilizing ions like phosphate and nitrate from the hydrogen peroxide solution makes the process more hazardous and additional measures have to be taken to ensure safety during the entire process.
Contradicting the teaching of WO 00/76989, WO 01/57012 discloses that the use of crude hydrogen peroxide solutions directly obtained from the anthraquinone process having large amounts of, for example, sodium, nitrate, phosphate, and organic impurities, is superior with respect to product selectivity compared to highly purified hydrogen peroxide solutions containing very low amounts of sodium, nitrate, and phosphate. The experiments, however, were only conducted for a few hours so that the long term activity and selectivity of the catalyst cannot be determined from that reference.
Again another approach is disclosed in WO 01/92242, wherein a titanium silicalite catalyzed process for epoxidation of olefins using crude hydrogen peroxide solutions in the presence of a compound having aminocarbonyl functionality in which the nitrogen bears at least one hydrogen atom is disclosed. The examples show a batch type process that is conducted up to a conversion of hydrogen peroxide of 85%. After two hours the reaction is terminated even if the conversion of 85% has not been reached. Although the experimental data show an improvement with respect to the reaction rate compared to compounds with aminocarbonyl functionality having no hydrogen atom bonded to the nitrogen atom, long term activity and selectivity of the catalyst in a continuous process is not determinable from the information in WO 01/92242.
DE-A 199 36 547 discloses a continuous titanium silicalite catalyzed process for epoxidation of olefins with hydrogen peroxide whereby the conversion is kept constant by increase of reaction temperature and adjusting the pH of the reaction mixture. In a long term experiment (1000 hours), it could be verified that by adjusting the pH the increase in temperature and the rate of increase could be reduced compared to an experiment without pH adjustment. But conversion and selectivity were the same, irrespective of whether the pH was adjusted or not.
Thus, the object of the present invention is to provide an aqueous hydrogen peroxide solution that can be economically produced, that can be safely handled, stored, and shipped, and that is suitable for the epoxidation of olefin in the presence of a heterogeneous catalyst and leads to improved long term activity and selectivity of the catalyst.
SUMMARY OF THE INVENTION
In carrying out the present invention there is prepared an aqueous hydrogen peroxide solution comprising:
i) less than 50 wppm of a member selected from the group consisting of an alkali metal, an alkaline earth metal or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form;
ii) less than 50 wppm of amines having a pk B of less than 4.5 or the corresponding protonated compounds in total; and
iii) at least 100 wppm anions or compounds that can dissociate to form anions in total,
whereby the wppm are based on the weight of hydrogen peroxide.
This inventive aqueous hydrogen peroxide solution can be obtained by a process for the preparation of the hydrogen peroxide solution according to the anthraquinone loop process comprising:
(a) hydrogenation of a working solution comprising an organic solvent or mixture of organic solvents and one or more active anthraquinone compounds,
(b) oxidation of the resulting hydrogenated working solution to form hydrogen peroxide,
(c) extraction of hydrogen peroxide with water,
(d) stabilizing of the resulting extracted aqueous hydrogen peroxide solution,
(e) concentrating the aqueous hydrogen peroxide solution to a concentration of hydrogen peroxide of at least 50% by weight based on the weight of the hydrogen peroxide solution,
(f) drying of the working solution after extraction, and
(g) regeneration and purification of the working solution, and during the entire process neither alkali or alkaline earth metals nor amines having a pk B of less than 4.5 or compounds forming such amines during the process are introduced in amounts that result in amounts of
i) 50 wppm or more of alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; or ii) 50 wppm or more of amines having a pk B of less than 4.5 or the corresponding protonated compounds in total; in the resulting aqueous hydrogen peroxide solution, where the wppm are based on the weight of hydrogen peroxide.
The hydrogen peroxide solution of the present invention is particularly suitable for use in a process for the epoxidation of olefins in the presence of a heterogeneous catalyst. It is a surprising result of the present invention that a hydrogen peroxide solution fulfilling the above-specified requirements and that can be safely handled, stored, and shipped, can easily be prepared in an economical process. Furthermore, surprisingly, this aqueous hydrogen peroxide solution leads to an improved long term activity and selectivity of the heterogeneous catalyst in an epoxidation process. Consequently, the overall economics of an epoxidation process can be considerably improved using the inventive aqueous hydrogen peroxide solution, since the solution itself can be economically produced and leads to reduced deactivation of the catalyst so that the operation time between regeneration cycles in the epoxidation process can be increased.
DETAILED DESCRIPTION OF THE INVENTION
The present inventors have thus discovered, contrary to the teaching of the prior art, that the presence of alkali metals and alkaline earth metals above a certain limit are detrimental to the activity and selectivity of the catalyst employed in epoxidation reactions of olefins. Moreover, the inventors have recognized that—in addition to alkali metals and alkaline earth metals—amines having a pk B of less than 4.5 are even more detrimental to the activity and selectivity of the catalyst, and therefore their content in hydrogen peroxide solutions that are used in epoxidation reactions of olefins has to be carefully controlled to be below the specified limits. On the other hand, anions like phosphate or nitrates, that are frequently used to stabilize aqueous hydrogen peroxide solutions, have no or only very little effect on the activity and selectivity of the epoxidation catalyst. Since these anions are necessary for the stabilization in order to ensure safety of handling, storing, and shipping of the aqueous hydrogen peroxide solution, they should be present in stabilizing amounts of at least 100 wppm based on the weight of the hydrogen peroxide in the solution.
Contrary to the teaching of the prior art, neither the use of crude hydrogen peroxide solutions obtained from the anthraquinone process without carefully controlling the amount of alkali metals and amines having a pk B below 4.5, nor the use of purified hydrogen peroxide solutions, where in addition to the metal cations also the stabilizing anions have been removed, are suitable for an economical process for epoxidation of olefins.
Although an amount of alkali metals or alkaline earth metals of less than 50 wppm based on the weight of hydrogen peroxide in the solution is acceptable, it is preferred to reduce the amount of these components to be less than 40 wppm, more preferred less than 35 wppm, in order to further improve the long term activity and selectivity of the catalyst.
So far, in the literature, the detrimental effect on amines having a pk B of less than 4.5 on the long term selectivity and activity of an epoxidation catalyst has not been recognized.
The effect of the presence of such amines is even more pronounced than the effect of the alkali metals or alkaline earth metals. Therefore, it is particularly preferred to reduce the amount of amines having a pk B of less than 4.5 in the aqueous hydrogen peroxide solution in total to less than 40 wppm, preferably less than 30 wppm, more preferably less than 20 wppm, and most preferably less than 10 wppm, based on the weight of hydrogen peroxide in the solution.
Especially detrimental to the activity and selectivity of the epoxidation catalyst is the presence of alkyl amines, especially secondary and tertiary alkyl amines.
Another surprising result of the inventors' investigations is that although amines having a pk B below 4.5 above certain amounts dramatically reduce the long term activity and selectivity of the epoxidation catalyst, the addition of at least 100 wppm of bases having a pk B of at least 4.5 even improve the long term activity and selectivity of the epoxidation catalyst. Thus, according to a preferred embodiment of the present invention, the aqueous hydrogen peroxide solution contains in addition at least 100 wppm of bases having a pk B of at least 4.5, or the corresponding protonated compounds in total based on the weight of hydrogen peroxide.
These bases may be either introduced during the process for preparation of the hydrogen peroxide or may be added to the hydrogen peroxide solution at any stage between production of the solution and final use in the epoxidation reaction.
Such bases are preferably present in the hydrogen peroxide solution in an amount of at most 3000 wppm in total, more preferred from 150 to 2000 wppm, particularly preferred from 200 to 1500 wppm, and most preferred from 300 to 1200 wppm, based on the total weight of hydrogen peroxide.
Such bases are preferably selected from organic amines and amides having a pk B of at least 4.5, organic hydroxylamines having a pk B of at least 4.5, ammonia and hydroxylamine. Ammonia is particularly preferred.
It is a particular advantage of the hydrogen peroxide solutions of the present invention that anions can be present in the usual stabilizing amounts. These stabilizing anions are preferably any kind of oxophosphorous anions like orthophosphate, hydrogen phosphate, dihydrogen phosphate, pyrophosphate, nitrate.
These stabilizing anions, or compounds that can dissociate in the hydrogen peroxide solution to produce these stabilizing anions, are preferably present in an amount of at most 1000 wppm, preferably 100-1000 wppm, more preferred 200-800 wppm, most preferred 200-600 wppm, based on the weight of hydrogen peroxide.
Thus, the hydrogen peroxide solution of the present invention ensures high selectivity and activity of a catalyst in the epoxidation reaction without compromising safety when handling, storing, and shipping the hydrogen peroxide solution.
Another advantage of the hydrogen peroxide solution of the present invention is that it can be easily produced in an economical way employing the well-known anthraquinone process, whereby additional purification steps are not necessary and are preferably not carried out when conducting the process of the present invention. The only requirement for the process of the present invention compared to the known modifications of the anthraquinone process is that the process has to be carefully controlled to avoid introduction of alkali metals, alkaline earth metals, amines having a pk B of less than 4.5, or compounds that may form, during the anthraquinone process, such amines during the preparation of the hydrogen peroxide solution in amounts that would result in concentrations above the limits specified according to the present invention.
Although many variations of the anthraquinone process to achieve this requirement are conceivable, it is particularly preferred to use a working solution that is essentially free of organic nitrogen compounds, to dry the working solution in above step (f) without using alkali metals or alkaline earth metal compounds that are in the anthraquinone process of the prior art commonly employed for drying, and to regenerate the working solution in step (g) by treating with active aluminum oxide. Preferably, drying is conducted by water evaporation in vacuum.
Thus, the process of the present invention provides the inventive hydrogen peroxide solution that is particularly useful in epoxidation reactions without employing cost- and labor-intensive purification steps. It follows that a crude hydrogen peroxide solution obtained from the process of the present invention can be used directly without any further purification steps.
It is preferred to concentrate the hydrogen peroxide solution to a hydrogen peroxide concentration of more than 50% by weight, preferably more than 60% by weight, most preferred from 60 to 70% by weight, based on the total weight of the hydrogen peroxide solution. The inventors have recognized that such concentrated hydrogen peroxide solutions are particularly useful in the epoxidation reaction since they further improve the long term activity and selectivity of the catalyst.
The hydrogen peroxide solution of the present invention can be employed in any epoxidation reaction using hydrogen peroxide known in the art. It is particularly preferred to use the present hydrogen peroxide solution in a continuous epoxidation process conducted in the presence of a water-miscible solvent and a heterogeneous catalyst. Preferably, the solvent is methanol, the olefin is propene, and the heterogeneous catalyst is a titanium silicalite catalyst.
The invention will now be explained in more detail with reference to the following examples.
EXAMPLES
Example 1
Preparation of an aqueous hydrogen peroxide solution according to the present invention.
In a trial plant for the loop process according to the anthraquinone process for the preparation of hydrogen peroxide comprising the steps of hydrogenation, oxidation, extraction, drying, and regeneration, a working solution is used comprised of 0.11 mol/l 2-ethyl anthraquinone, 0.29 mol/l 2-ethyl tetra-hydroanthraquinone, 0.13 mol/l 2-isohexyl anthraquinone, and 0.12 mol/l 2-isohexyl tetra-hydroanthraquinone in a solvent mixture comprising 75 vol % of C 9 /C 10 alkyl substituted aryl compounds, and 25 vol % of tris(2-ethyl hexyl) phosphate. In the hydrogenation step, a loop reactor was run at a hydrogen pressure of 0.35 and a temperature of 58° C. Palladium black (0.5:1 g/l) was used as hydrogenation catalyst. The hydrogen peroxide equivalent in the hydrogenation was 13.0 g/l.
After the hydrogenation, a part of the hydrogenated working solution is regenerated using active aluminum oxide. Thereafter, the combined working solution is oxidized using the Laporte oxidation as described in Ullmann, supra, page 14. Thereafter, the hydrogen peroxide is extracted using deionized water. To the extraction water, 50 ppm H 3 PO 4 and 20 ppm HNO 3 , both based on the weight of the hydrogen peroxide were added. The concentration of the extracted aqueous hydrogen peroxide solution was 41%. The working solution was dried by water evaporation in vacuum, and thereafter recycled to the hydrogenation step. The crude hydrogen peroxide solution was stabilized using 200 ppm sodium pyrophosphate based on the weight of hydrogen peroxide and concentrated in vacuum by water evaporation.
The hydrogen peroxide concentration of the solution obtained in this way was 43 wt-%, based on the total weight of the solution, and contained 250 mg/kg H 2 O 2 phosphates, 20 mg/kg H 2 O 2 nitrate, and 30 mg/kg H 2 O 2 of sodium.
Examples 2 to 5 and Comparative Examples 1 to 3
The hydrogen peroxide solution obtained from Example 1 is concentrated to a hydrogen peroxide concentration as indicated in Table 1.
Additionally, alkali metal ions and/or amines having a pk B of less than 4.5 are added as indicated in Table 1. Furthermore, ammonia is added in an amount of 500 wppm (1000 wppm ammonia in example 5), based on the weight of hydrogen peroxide.
A titanium silicalite catalyst was employed in all examples. The titanium silicalite powder was shaped into 2 mm-extrudates using a silica sol as binder in accordance with Example 5 in EP-A 1 138 387.
Epoxidation is carried out continuously in a reaction tube of 300 mm volume, a diameter of 10 mm, and a length of 4 m. The equipment further comprises three containers of liquids and relevant pumps and a liquid separation vessel. The three containers for liquids contained methanol, the hydrogen peroxide solution, and propene. The reaction temperature is controlled via an aqueous cooling liquid circulating in a cooling jacket, whereby the cooling liquid temperature is controlled by a thermostat. The reaction pressure was 27 bar absolute. Mass flow of the feeding pumps were adjusted to result in a propene concentration of 38 wt-%, a methanol feed concentration of 48.7 wt-%, and a hydrogen peroxide feed concentration of 8 wt-%. The reactor was operated in down-flow operation mode. The cooling jacket temperature was adjusted to 35° C. and total mass flow was 0.35 kg/h. Product output and propene oxide concentration were determined by gas chromatography, and the hydrogen peroxide conversion by titration. The selectivity of hydrogen peroxide with respect to propene oxide was calculated.
The results are given in Table 1.
TABLE 1
Addition
H 2 O 2
Running
SH 2 O 2
Exam-
[mg/kg
concentration
time
CH 2 O 2
to PO
ple
H 2 O 2 ]
[wt-%]
[h]
[%]
[%]
2
—
60
649
95
91
3
Na 25
70
754
95
90
4
Li 25
60
988
94
89
5
—
60
2356
94
90
C1
Na 20; dibutyl
43
2083
26
72
amine 135
C2
methyl amine
60
1193
22
81
100
C3
170
60
1007
89
79
In Table 2, the pk B values for nitrogen-containing bases are given.
TABLE 2
Bases
pk B
Ammonia
4.76
Methyl amine
3.36
Dibutyl amine
2.75
As is evident from the experimental results summarized in Table 1, high hydrogen conversions and selectivities can be maintained for a long running time of the experiment if the alkali metal concentration is below 50 wppm, based on the weight of hydrogen peroxide. When looking to the comparative examples, it becomes evident that if the claimed limits for alkali metal ions and amines having a pk B below 4.5 are exceeded, the conversion as well as the selectivity of the catalyst dramatically drops over time.
Further variations and modifications of the foregoing will be apparent to those skilled in the art and are intended to be encompassed by the claims appended hereto. | An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pk B of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed. | 2 |
This application is a Reissue of Ser. No. 08 / 425 , 440 , filed Apr. 20 , 1995 , now U.S. Pat. No. 5 , 584 , 198 , issued Dec. 17 , 1996 .
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to machines and methods for forming metal panels for constructing metal buildings, and more particularly relates to apparatus and methods for forming curved building panels from flat sheet metal material by crimping.
2. Background and Prior Art
It is known in the prior art to construct metal buildings from metal panels which are arched or curved, assembled side-by-side and seamed together. See U.S. Pat. No. 3,902,288 to Knudson. In such buildings the roof panels continue as the side walls of the building and the basic building construction is in the shape of a self-supporting continuous arch or semicircle when viewed from one end. A machine for making the building panels in which U-shaped panels are corrugated or crimped both on the bottom or “belly” and on the sides to create the curvature is shown in U.S. Pat. No. 3,842,647 to Knudson.
An arched building construction in which the walls and roof are completely arched has advantages, but also has a number of limitations. One limitation is the absence of vertical walls which limits the use of vertical space. Users of metal buildings often want vertical walls both for aesthetic purposes as well as to obtain the use of more vertical space near the edges to the building. The basic size and strength of such metal buildings is also limited by wind and live load limitations as established by local and national building codes. A completely arched building must be limited in size in order to prevent overloading as could occur from extensive wind loads produced by hurricanes. However, when the total roof height is reduced to approximately one-fifth of the total building width, hurricane force winds do not affect the building as much because of the reduced frontal area.
Improvements to the above technology are disclosed in U.S. Pat. Nos. 5,249,445 and 5,359,871 to Morello, incorporated by reference herein in their entirety. These patents disclose microprocessor-controlled methods and apparatus wherein metal building panels could be formed by automatically controlling the radius of curvature and wherein the panels may have a straight as well as a curved portion so that metal panel buildings could be constructed with arched roofs and vertical walls. The cited Morello patents disclose the use of hydraulics and microprocessor controlled machinery which forms U-shaped building panels of predetermined length from a coil of sheet metal. The formed panels are then continuously crimped on their side edges for strength and are adjustably curved by crimping the belly of the panel. The crimping is automatically controlled so that building panels may be formed with vertical wall portions and curved or arched roof portions.
A problem in the prior art, however, was the fact that the depth of the crimp on the side edges of the panel remained constant, even as the radius of the panel being curved changed. If the radius of the panel was tight, and the depth of side crimp was shallow, the side walls of the panel buckled due to the excess material not taken up by the crimp. Analogously, if the radius was large or the panel section being formed was straight, and the depth of side crimp was deep, the belly of the panel buckled due to excess material in the belly not taken up by the crimping. Because of the physical distance between the side crimping apparatus and the main crimping apparatus, the simultaneous adjustment of the side and main crimping apparatus caused the length of panel between the side crimper and the main crimper during this adjustment not to have the change in depth of crimp on the side walls, which caused the buckling effect discussed above. Thus, there exists a need in the art for improvement to such apparatus and methods to eliminate the deleterious buckling effects caused by adjustment of the crimping mechanisms during formation of such panels.
SUMMARY OF THE INVENTION
The panel crimping apparatus and method of the present invention is unique in that the depth of crimp in the side portion of a metal building panel is controlled by a microprocessor and the side crimping rollers are adjusted independently of the main crimping rollers, according to the radius of panel being curved and the length of panel that has passed through the apparatus. The present invention thus eliminates the problem of metal panel buckling in the prior art when the radius of curvature of a building panel was varied during formation.
The crimping apparatus includes two sets of rotatably mounted panel side portion crimping rollers with the sets mounted vertically with respect to each other and the rollers mounted horizontally on shafts. The outside roller of each set is rotatably mounted on a shaft supported at both ends by stationary bearings. The inside roller of each set is rotatably mounted on a cantilevered shaft supported on only one end by bearings. The bearings of the cantilevered shaft are mounted in a non-stationary sliding block that is movable in the direction of the stationary crimping rollers, thus creating a change in the depth of crimp by changing the distance between the inside roller and the outside roller. The sliding mechanism consists of male and female V-grooved guide bars, with the male guide bar being attached to the sliding block and the female guide bar being attached to a main support plate. Extending through the center of the main plate is a machine screw which is supported on the reverse side of the main plate by a block that houses three angular-contact bearings. On this machine screw is a bronze nut that is attached to a block mounted horizontally in a plane at a right angle to the crimping rollers. This block is the center point for a scissors-jack type linkage that extends to each of the two non-stationary crimping roller blocks. The linkage is such that as the machine screw is rotated, the linkage center block moves along the screw to cause the non-stationary crimping roller blocks to slide in the direction perpendicular to the screw and thus change the depth of crimp.
Mounted on the opposite side of the machine screw is a universal joint which constitutes a coupling to a hydraulic motor. A linear encoder tracks the position of the center linkage block along the length of the machine screw and sends that information to a microprocessor. A rotary encoder tracks the length of panel that is being crimped by the apparatus and sends that information to the microprocessor. The rotation of the hydraulic motor that controls the depth of crimp is controlled by a valve that is controlled by the microprocessor. The microprocessor determines when to adjust the crimping rollers and to what depth based on the information received from the encoders.
Each shaft that supports the crimping rollers also supports a gear that fits into a drive train. This drive train is driven by a hydraulic motor separate from the motor that adjusts the crimping depth. The drive train motor controls the rotary motion of both the side crimping rollers and the main crimping rollers, and is also controlled by the microprocessor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a preferred embodiment of the side crimper apparatus disconnected from the entire building panel forming machine and showing a portion of a panel midway through the side crimper;
FIG. 2 is a side view of the side crimper apparatus of FIG. 1 from the direction of entry of the panel;
FIG. 3 is an isometric view of the slide blocks and linkage arms of the side crimper apparatus according to a preferred embodiment of the invention; and
FIG. 4 shows an isometric view of the center linkage adjustment mechanism of the side crimper apparatus according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail, referring to FIGS. 1-4. The panel 1 being crimped has a bottom or “belly” 10 and two sides 20 at 90 degrees to the belly. The panel feeds into the side crimping apparatus 30 in the orientation shown. There are inside crimping rollers 40 (FIG. 2) and opposing outside crimping rollers 50 . The rollers consist of a steel hub with blades welded radially around the perimeter of the hub so as to cause a corrugated crimp 21 in the sheet metal panel when it is passed through mating sets of rollers. The top outside crimping roller is rotatably mounted on a steel shaft 60 that is supported on both ends by bearings 62 . The bearings are mounted in a steel main plate 80 and an aluminum outside plate 90 . On the main plate side, the top shaft 60 continues through bearing 62 and supports a gear and sprocket which are components of rotary motion drive train 100 . The bottom outside shaft 70 differs from shaft 60 only in that it is not directly connected to drive train 100 but continues through the bearing housed in the outside plate 90 and supports a miter gear 72 that serves as a link to the main curver drive train (not shown), which powers the forward rotation of the crimping rollers 40 and 50 . The bottom shaft 110 is supported by a bearing at each end with one end continuing through the main plate bearing to support a gear and sprocket which are further components in the rotary motion drive train 100 .
The rotary motion drive train 100 is configured such that the top and bottom sets of crimping rollers rotate together to feed the panel 1 through the apparatus. The inside crimping rollers 40 are rotatably mounted on cantilevered shafts 42 which are supported only on one end by bearings 44 so as to allow the belly 10 of the panel to pass through the other side 46 . The bearings 44 are press fitted into aluminum slide blocks 48 . In each slide block 48 there are two bearings (not shown) mounted back to back to aid in supporting the load of the panel being crimped.
The shafts 42 continue through the slide blocks 48 and the main plate 80 to support gears that fit into the rotary drive train. Each edge of the slide blocks 48 holds a male guide bar 15 (FIG. 3) which slides vertically along a female guide bar 16 . The guide bars 15 and 16 are “V” grooved in shape. This causes the slide bars to be self-centering and to have a large contact area to aid in high load support. All edges of the male guide bar 15 are rounded to prevent them from catching or knifing into the female guide bar 16 as they are sliding. The female guide bars 16 are permanently attached to the main plate 80 . Both sets of guide bars are constructed of high strength, hardened steel that has an Armoloy plating. All of these features lead to a durable, low friction slide made to withstand high loads.
Mounting holes 33 in the female guide bars are slotted so as to allow the female guide bars to adjust closer to the male guide bars and ensure that they seat firmly together so as to take advantage of the self-centering properties of the “V” groove. Steel stiffener plates 17 , which are attached to main plate 80 , hold set screws 35 which tighten onto the backs of the female guide bars to perform this adjustment and to ensure that the guide bars will not slip back after the adjustment. The stiffener plates 17 also prevent the main plate 80 from flexing due to the loading. The inner ends of the slide blocks 48 have milled slots 34 which accommodate steel linkage arms 18 . The linkage arms are mounted at one end to the sliding blocks 48 using Teflon permeated plane bearings 19 which ride on high tensile strength precision ground shoulder bolts 39 so as to allow a pivoting motion of the linkage arms with respect to the sliding blocks.
The other end of the linkage arms 18 are connected to a steel, Armoloy coated center linkage block 51 (FIG. 4) via additional shoulder bolts. Center linkage block 51 has the male portion of a dovetail joint machined into both ends. The female portion of the dovetail joint is machined into two steel, Armoloy coated upright guide blocks 52 . The purpose of the Armoloy coating is rust prevention and an extremely hard, smooth surface to act as a bearing surface. The upright blocks 52 are solidly mounted to both the main plate 80 and the stiffener plates 17 for extra rigidity. This configuration allows the center linkage block 51 to travel only in a linear horizontal sliding motion, preventing the panel load from forcing the entire inside roller and slide block assembly along the vertical plane.
The center linkage block 51 houses a bronze acme-threaded bearing nut 23 (FIG. 4 ). Machine screw 24 travels through a clearance hole in the center linkage block 51 , a clearance hole in the main plate 80 , and into a set of three angular contact bearings 25 (FIG. 2) that are housed in an aluminum bearing block 26 . Angular contact bearings have the ability to support both axial and radial loads. Two of the three bearings are oriented to support an axial load in the direction towards the outside plate 90 and the third bearing is mounted opposite of the other two. The machine screw 24 is constrained from axial travel by a machined shoulder that rests against the third angular contact bearing on the side closest to the main plate 80 , and a threaded bearing nut 27 on the opposite side of main plate 80 to remove any axial play, ensuring an accurate system.
A universal joint 28 provides a rotary link between the machine screw 24 and a hydraulic motor 29 . As the machine screw 24 is turned by the motor 29 , the nut 23 causes the center linkage block 51 to travel axially along the machine screw. As the center linkage block 51 moves closer to the main plate 80 , the linkage arms 18 flatten vertically and push against the slide blocks 48 , causing them to slide along the guide bars toward the stationary outside crimper rollers 50 , thus moving inside crimper rollers 40 closer to rollers 50 , resulting in a deeper crimp. When the rotation of the machine screw is reversed, the center linkage block 51 travels away from the main plate 80 , pulling the linkage arms 18 with it. This causes the slide blocks 48 to be pulled down along the guide bars, moving inside rollers 40 away from the stationary crimper rollers 50 , resulting in a shallower crimp.
A microprocessor (not shown) controls the valves that control the hydraulic motor 29 . The microprocessor receives inputs from a rotary encoder 120 (FIG. 1) and a linear encoder 31 (FIG. 4 ). The rotary encoder measures the length of panel that has traveled through the apparatus. The linear encoder is linked through a stainless steel shaft 32 to the center linkage block 51 , enabling the encoder to track the linkage block's position along the machine screw and relay that information to the microprocessor. The microprocessor determines at what depth the side crimpers need to be at predetermined locations along the panel length, independently from the main crimpers. The aforementioned U.S. Pat. No. 5,359,871 discloses other capabilities and functions of the mentioned microprocessor.
The side crimper control function of the microprocessor has the ability to perform the following tasks:
enable/disable the entire side crimper adjust function;
determine the depth of crimp as a function of panel material thickness and radius at which the panel is being curved;
control the direction and start/stop of the hydraulic motor 29 to reach the desired depth of crimp;
control the speed of the hydraulic motor including a standard high and low speed;
set electronic safety stops for the maximum and minimum depth of crimp;
LCD readout of the rotary and linear encoder positions; and
determine the position along the panel to begin adjusting as a function of the type of panel being formed, the speed at which the curver is being run, and the total change of depth.
Of course, the microprocessor may be used to carry out many other functions in addition to those mentioned above.
The invention having been thus described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the invention. Any and all such modifications as would be obvious to those skilled in the art are intended to be within the scope of the following claims. | Apparatus and method for crimping the side walls of a sheet metal building panel independently of a main crimper which crimps the belly of the panel. The depth and the position along the panel of the side crimp is adjusted independently of the main crimpers in relation to the radius the panel is being curved and the length of panel that has passed through the apparatus. The adjustment is controlled by a microprocessor. The microprocessor controls a hydraulic motor which drives a machine screw which activates a scissors-jack type linkage. Blocks holding the rotatably mounted crimping rollers are mounted on slides and attached to the linkage. As the linkage moves, the depth of the crimping rollers is adjusted. The rotation of the crimping rollers is hydraulically driven through a gear-sprocket rotary motion drive train. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/381,996, filed Sep. 12, 2010, the entire of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to positive displacement pumps, and more particularly, metering pump that provides a continuous fluid flow of an adjustable volume.
BACKGROUND OF THE INVENTION
[0003] Metering pumps are commonly used to pump fluids when fluid flow rate must be precise and adjustable. The term “metering pump” is based more on the use of the pump rather than the actual type of the pump used. There are several classes of pumps that are typically used to meter fluids, including piston, diaphragm and peristaltic pumps. Each of these classes of pumps include a pump head and a motor that is operatively connected to the pump head to drive the pump head to pump or meter a fluid to a desired delivery location at a precise and adjustable flow rate. Further, pump heads may be classified as a loss-motion type or a no loss motion type. A loss-motion pump has a discontinuous positive fluid displacement during a fluid displacer's discharge stroke, whereas a no loss motion pump has a continuous positive fluid displacement. For the purpose herein, the invention is generally concerned with piston or diaphragm no loss motion type pumps or the like.
[0004] Conventional piston or diaphragm metering pump are well known in the art, and accordingly, a complete description of such is not warranted here for an understanding of the embodiments of the invention. However, in the basic concept a piston or diaphragm or the like may be termed as a fluid displacer that is moved within a housing having a pump cavity into which the fluid displacer is disposed. The displacer is reciprocated within the pump housing to create and collapse the volumetric size of the cavity. There is set of check valves or other form of valves located on the suction and discharge sides of the pump housing. The valves are so designed to allow the creation and collapsing of the cavity or chamber to create liquid displacement. The valve operational timing is so designed to isolate the differential pressure across the pump housing during its normal operation. The displacer within the pump housing is mechanically or mechanically hydraulically connected to some of transmission. Typically an electric motor applies rotary motion to the transmission to operate the metering pump and cause displacement.
[0005] Conventionally, the transmission includes an eccentric member that converts rotary motion to reciprocating motion. The transmission will have a form of mechanics for speed ratio and torque adjustment. There are other various ancillary components of common art within the pump to make a fully operational metering pump. They will have some form of mechanics or hydraulics to change the stroke length. Conventional no-loss pumps typically utilize eccentric members that create sinusoidal motion or similar to a sinusoidal motion for their reciprocating motion. These forms of reciprocating motion when applied to a duplex pump design cannot create sufficient substantially continuous non-pulsating displacement. The liquid being pumped always has period of zero velocity across the pump. This will cause undesirable pulsating liquid flow rates. They typically do not create the preferred continuous displacement motion of the invention.
[0006] Various electronic solutions have been proposed and utilized to reduce or eliminate the undesirable pulsating liquid flow rate. In one solution a synchronous motor is used to driver the displacers which are modulated through control electronics to control the fluid flow rate and reduce pulsing. Other solutions include digital controlled solenoid driven pumps which have been successful to a point in producing non-pulsating liquid flow rates. However, they have limited flow rates and pressures limitations due to the limitations of solenoid technology. They cannot create true continuous fluid flow at certain flow rates and fluid pressure.
[0007] There are a number of duplex mechanical metering pumps that incorporate continuous non-pulsating flow rate and incorporate mechanical stroke length modulation. A few use barrel cams, because they can create substantially uniform constant velocity stroke motion. When applied to two or more displacers they can create substantially uniform liquid flow rates. One example of a duplex pump utilizes a form of barrel cam style mechanical member. It can create continuous low pulsating flow rates. The stroke modulation is not integral. It is an added mechanical hydraulic mechanism. This adds extra components and complexity to its design and has not been readily accepted by the market. Another mechanical pumps may utilize a barrel cam, but do not have a stroke adjustor. As discussed above, there is exists digitally controlled synchronous motor driven metering pumps that have accomplished non-pulsating flow rates. They can create substantially non-pulsating flow rates, but current commercially offerings do not create substantially continuous flow rate delivery. They can achieve wide flow rate turn down creation as required for metering pumps They tend to be limited by cost and complexity. Embodiments, of a duplex version of the invention can deliver substantially or sufficient continuous flow rate delivery and low pulsations being imposed upon the pumped liquid. This preferred flow delivery is sustained through its zero to 100% stroke length modulation.
[0008] Various manufacturers produce pumps with single “simplex” or multiple pump heads “duplex”. Each pump head has a batch delivery of liquid displacement. Each batch is always defined by a two moments of zero liquid displacement with liquid displacement between those moments. These zero liquid displacement moments for each batch causes the liquid being displaced across the pump to go from a position of rest to high rates of velocity over very small increments of time back to a position of rest.
[0009] The all mechanical single and duplex pumps of common art typically create non-linear, non-proportional and non-continuous liquid flow rates during their normal operation. The more commonly sold pumps of common state of art require at least three or more displacers to create continuous liquid flow rates. Pumps that utilize three or more displacers can be phased to create a more substantially constant velocity across the pump at any given rotational speed. There is prior art for two displacers creating continuous flow rates. The invention can be designed for three or more displacers with integral stroke length modulation.
[0010] The physics of metering pumps is that they create batch flow rates. Each displacer displaces a given batch volume of liquid for each displacement cycle. The current state of art typically has the liquid being pumped going from zero velocity at the beginning of a batch to peak velocity and back to zero at the end of the batch. This causes negative pulsating liquid flow rates. This is transferred to the liquid up-stream and down-stream of the pump. This sudden change in liquid velocity creates mass acceleration problems applied to the liquid being pumped. It can create what is commonly called water hammer or cavitation. This is due to the sudden stopping of the liquid on the suction side of the pump at an end of a batch cycle. This causes a resultant high pressure to be enacted upon the pumped liquid on the suction side of the pump. This is due to the liquid on the suction side being a mass in motion that wants to stay in motion, but is suddenly stopped. At the end of a batch cycle the liquid pumped to the discharge side of the pump goes to zero velocity. The liquid has motion and tends to continue in motion. The sudden loss in liquid velocity causes a low pressure to be enacted upon the liquid at the discharge side of the pump. This process is repeated many times per minute. This occurs on the majority of applications of the current state of art for simplex and duplex metering pumps. A typical duplex pump has two batch liquid flows per revolution, but the pulsating flow remains. These negative flow characteristics are imparted to the liquid being pumped from the source to the point of application. Typically the source is a tank at a given distance to the pump. The application point is at given distance from the pump. These negative hydraulics characteristics created by the pump are transferred to the entire pumping system. The result is pulsating flow rates are transferred to the entire pumping system. This cause many negative issues. The invention shares these negative liquid hydraulics characteristics local at its suction and discharge at each of its reciprocating pump. Unlike the common art, the invention with two displacers can create substantially net constant liquid velocity across the pump. This is unlike the typical common art for a duplex pump with integral mechanical stroke adjustor. The overall pumping system is exposed minimal or virtually no pulsating liquid flow rates.
[0011] Typically the manufacturers of current state of art metering pumps recommend accessories to remedy the associated problems created by pulsating flow rates. If these accessories are not applied the pump may not operate properly and could cause a failure of the pump and pumping system. The typical solution to pulsating flow rates is the addition of peripheral equipment such as a back pressure valve and pulsation dampener or accumulator. They typically sufficiently mitigate the severity of the pulsating liquid flow rate. The addition of the pulsation dampener adds costs and complexity for a complete installation of a pumping system. It also adds its own set of maintenance issues. This same pulsating flow typically inherent in the current state of art of duplex metering pumps can cause liquid siphoning across the pump. This tends to negate the proper functioning of the check valves. It also can create the discharge piping to vibrate and be mechanically stressed. The recommend accessory to mitigate the problem is a back pressure valve. The valve is located on the discharge side of the pump. This creates enough pressure resistance to force the check valves to properly seat and to assure a satisfactorily operating pump. The back pressure valve reduces the potential for liquid siphoning across the pump. Some process applications have sufficient minimum back pressure to negate the requirement for a back pressure valve. It is typical for the pump manufacture to recommend the installation of the back pressure valve as a precaution of the potential problems. The back pressure valve adds costs and its own set of problems. The invention as a duplex pump creates sufficiently continuous low pulsating flow rates that it eliminates the need for pulsation dampeners or accumulators. In addition it further reduces the applications that would require a back pressure valve if certain minimum back pressure value is present.
[0012] There are process applications that utilize a flow meter in close proximity to these pumps that approximately verify that the pump is delivering the desired volumetric liquid required. They are at times used, but are more limited due to the typical pulsating flow for the duplex pumps of the current common art. Pulsating liquid is more difficult for a flow meter to accurately measure. Flow meters are typically calibrated with constant liquid head conditions at different constant liquid velocities. The typical state of art for duplex metering pumps with integral mechanical stroke adjustor do not create constant liquid velocities or constant head conditions. That is due to their pulsating flow rates that create variable liquid velocities. The variable liquid flow rate velocities cannot create constant head conditions on the suction and discharge sides of the pump. This virtually assures that the flow meter cannot measure the pumped liquid output to the stated accuracy and repeatability of the flow meter. This assures an accuracy offset that cannot be fully resolved. It would be desirable to pair a flow meter for verification, certification and calibration to national and international standards of a duplex metering pump. That is to match the flow rate creation of the metering pump to the flow meter. These international bodies such as the National Institute of Standards and Technology “NIST” a US based third party and outside the US such as DKD, NABL and others. Most manufacturers of higher accuracy flow meters calibrate to one or more of these recognized third party standards. All of these international flow calibration institutes, which certify to traceable internationally accepted standards, require constant liquid velocities. This constant liquid velocity is consistent with constant positive pressure of the inlet flow that is constant head of the source liquid. These third parties have developed measurement standards that allow manufacturers to assign quality controlled traceability of their calibration procedures. The manufacture can then state that their flow meters conform to a specific body of standards. Their flow meters will have a traceable accuracy and repeatability to a specific standard. The flow meter can claim a pedigree to a transferable standard. For example the flow meter would state that their flow meters are NIST traceable. The pulsating flow characteristics of the common art for duplex pumps tend to limit the use of flow meters, although they are used. The invention as a duplex pump can be calibrated to NIST or one of the other standards organizations requirements for transferability of pedigree. That is done by paring the suction or discharge side of the pump to a traceable flow meter. The invention as a duplex pump will be operated at fixed speeds and stroke length. The momentary produced flow creation of the invention will be compared to the momentary flow rate of the calibration flow meter. This comparison will create a calibration curve data sheet that will be certifying the traceability of the invention to a pedigree flow meter. The pedigree of the flow meter is transferred to the invention. No duplex metering pump of current art is claiming the ability to be calibrated to NIST, DKD, NSBL or any other like type standard. The invention with two displacers creates sufficiently continuous non-pulsating flow rates at substantially constant liquid velocities. These created substantially constant liquid velocities by the invention allow for a constant head creation in a close loop calibration rig. This means that the calibration requirement to these international bodies' standards for flow meter calibrations is transferrable to the invention. This compatibility of hydraulics allows the invention to be certified to any one of these standards and will be so claimed. This will give a more accurate and true verification of the pump's accumulated liquid flow rates over time as compared to the state of art. This also allows for more accurate momentary flow rate verification between the invention and a properly installed flow meter. There seems to be no traceable certified metering pump commercially available as of this filing.
[0013] A typical scenario for use of a metering pump is to add one liquid to another at a controlled desired continuous proportional ratio. Proper mixing allows for the optimum homogeneity and combines the two or more liquids. As common to the state of art for metering pumps they deliver pulsating liquid flow rates even with two displacers. This reduces the ability to achieve highly homogenous blends between two or more constituents or chemicals. The invention would allow for an optimum ratio of two or more liquids. This is due to the ability to have virtually one constant liquid velocity being combined to another virtually constant velocity liquid. The invention can maintain a fixed pumped flow rate delivery. The flow rate delivery by the pump is constant and if the primary chemical flow rate is constant then the invention can maintain a substantially constant fixed ratio. This is not achieved in the current state of art for duplex metering pumps. There are many industries that desire this ability.
[0014] Common to all metering pumps as with the invention is the need for some form of valves to be used to operate. The most common are ball check valves. Other types substitute the ball for cones or discs. Under certain conditions the check valves the balls, cones or discs can float off their seats when the pump is not operating. This allows for the source liquid to the suction side of the pump to flow across the pump. The source liquid is typically from a tank and under certain conditions the pump will drain the tank. This is commonly due to an operator error. The invention has an option for seating the diaphragms in their respective pump housing. This can be manually activated by an operator or automatically activated. This option is most effective when it is on the invention that has the smart electronics with the motor driven stroke adjustor. This automatic option would be programmed into the pump so that when the pump is shut-off or in stand-by it will seat its diaphragms before stopping. This assures that the pump will not allow the liquid to leak across the pump.
[0015] There does not seem to be common art for the ability of duplex or more displacer metering pump to mechanically engage and disengage a displacer in the field. This ability would allow for greater flow rate turn down, flexibility in manufacturing and field modification. The invention incorporates allow for an optional mechanical diaphragm engagement pin and mechanism for each driven diaphragm. This allows for a pump to be converted to a simplex pump to a duplex by adding a second pump housing in the field.
[0016] Any pump that does not produce continuous flows will have non-continuous torque demand to operate. This means that the torque demand will have peaks that require greater torque to operate at the peaks. For example a pump of common art that produces a sinusoidal volumetric displacement will have that peak torque of the sine curve. This means that a larger motor will be required to meet peak torque demands. The larger motor will require more current to operate. The non-continuous flow rate pumps will typically consume more power to operate than a continuous flow rate pump during its normal operation. The invention would typically have a smaller motor for any given volumetric displacement over the state of art of metering pumps
SUMMARY OF THE INVENTION
[0017] Embodiments of the present invention address and overcome the drawback of existing no-loss motion reciprocating metering pump by providing a metering pump including a transmission and stroke modulation assembly that provides a continuous and adjustable fluid flow without fluid pulsation.
[0018] Embodiments of the present invention also provide a metering pump including a transmission and stroke modulation assembly including three-dimensional, variable profile conjugate cams.
[0019] Embodiments of the present invention also provide a metering pump including a transmission and stroke modulation assembly that permits conversion between simplex and duplex pump configurations.
[0020] Embodiments of the present invention also provide a metering pump including a transmission and stroke modulation assembly that prevents fluid flow across the pump during non-operational periods
[0021] Embodiments of the present invention also provide a metering pump including a transmission and stroke modulation assembly that can be calibrated to a flow meter with constant head at a given constant velocity.
[0022] Embodiments of the present invention also provide a metering pump that can be calibrated to a flow meter with constant head at a given constant velocity
[0023] To achieve these and other advantages, in general, in one aspect, a fluid metering pump is provided. The fluid metering pump includes a first reciprocating pump have a first fluid displacer, a second reciprocating pump having a second fluid displacer and a transmission and stroke adjuster assembly for coupling a prime mover to each of the first and the second fluid displacers and converting a rotary movement of the prime mover into a reciprocating stroke movement of the first and the second fluid displacers. The transmission and stroke adjuster assembly includes a driven shaft rotatable about an axis of rotation, first and second three-dimensional cam members mounted to the driven shaft for conjoined rotation therewith, the first and second cam members are congruent with respect to one another, a first pair of followers in contact with the first cam member on opposite sides thereof, the first pair of followers connected to the first fluid displacer and imparting a reciprocating motion on the first fluid displacer during rotation of the driven shaft, a second pair of followers in contact with the second cam member on opposite sides thereof, the second pair of followers connected to the second fluid displacer and imparting a reciprocating motion on the second fluid displacer during rotation of the driven shaft, and, wherein the first cam member and the second cam member each have a non-cardioid shape cam profile that results in a constant velocity reciprocation motion of the first and second pair of followers during rotation of the driven shaft.
[0024] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
[0025] Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The following drawings illustrate by way of example and are included to provide further understanding of the invention for the purpose of illustrative discussion of the embodiments of the invention. No attempt is made to show structural details of the embodiments in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Identical reference numerals do not necessarily indicate an identical structure. Rather, the same reference numeral may be used to indicate a similar feature of a feature with similar functionality. In the drawings:
[0027] FIG. 1 is a top view of pump in accordance with an embodiment of the invention;
[0028] FIG. 2 is a perspective view of a pump in accordance with an embodiment of the invention;
[0029] FIG. 3 is a side view of a pump in accordance with an embodiment of the invention;
[0030] FIG. 4 is a partial cross-sectional view of a pump in accordance with an embodiment of the invention;
[0031] FIGS. 5 a and 5 b are representative illustrations of positional locations of oppositely located and simultaneously driven diaphragm members;
[0032] FIGS. 6 a and 6 b are representative illustrations of positional locations of oppositely located and simultaneously driven diaphragm members;
[0033] FIGS. 7 a and 7 b are representative illustrations of an operational position of oppositely located and simultaneously driven diaphragm members;
[0034] FIG. 8 is a diagrammatic perspective view of a three dimensional conjugate cam in accordance with the principles of the present invention;
[0035] FIG. 9 is a diagrammatic end view of the conjugate cam of FIG. 8 ;
[0036] FIG. 10 is a diagrammatic, partial assembly of the conjugate cam and drive shaft;
[0037] FIG. 11 is a diagrammatic plan view of the conjugate cam of FIG. 8 including spherical followers;
[0038] FIG. 12 is a diagrammatic perspective, exploded view of a transmission and stroke adjuster assembly in accordance with an embodiment of the invention;
[0039] FIG. 13 is a diagrammatic side view of the transmission and stroke adjuster assembly partially assembled;
[0040] FIG. 14 is a diagrammatic perspective view of the transmission and stroke adjuster assembly with portions thereof removed for purpose of illustrative clarity;
[0041] FIG. 15 is a diagrammatic perspective view of the transmission and stroke adjuster assembly with portions thereof removed for purpose of illustrative clarity;
[0042] FIG. 16 is a diagrammatic top view of the transmission and stroke adjuster assembly;
[0043] FIG. 17 is a diagrammatic side view of the transmission and stroke adjuster assembly;
[0044] FIG. 18 is an illustrative plan view of an alternative embodiment in accordance with the invention; and
[0045] FIG. 19 is a fluid flow diagram illustrating fluid flow characteristic of embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0046] In FIGS. 1 to 3 , a metering pump representatively embodying the principles of this invention is designated generally by reference number 114 . Metering pump 114 , as illustrated here, takes the form of a duplex pump head having a pump head casing or gear box 109 supporting oppositely positioned reciprocating pumps 101 a and 101 b . Casing or gear box 109 further supports a prime mover mounting flange 105 for the attachment and the connection of a prime mover to the pump head 114 , stroke length indicator 108 that operates to indicate the stroke length of each fluid displacer, a stroke length control knob 104 that is operated by a user to adjust the stroke length of each fluid displacer (herein illustrated as diaphragms), and pump head mounting flanges 111 for attaching the pump head to a suitable mounting surface.
[0047] Each reciprocating pump 101 a and 101 b include fluid suction ports 150 a and 150 b , respectively, and fluid discharge ports 152 a and 152 b , respectively. Fluid suction ports 150 a and 150 b are configured to be connected to a source of fluid by suitable fluid carrying conduits or the like. Fluid discharge ports 152 a and 152 b are configured to be connected suitable fluid carrying conduits for the delivery of the pumped fluid. As it will be further described below, reciprocating pumps 101 a and 101 b include access ports 110 a and 110 b , respectively, that permit an operator access to the driven shaft connected to each respective fluid displacer for either the engagement or disengagement of the fluid displacer from its driven shaft to enable or disable the operation of the respective fluid displacer. To this end, the representatively illustrated duplex pump head 114 may be converted between a simplex configuration and a duplex configuration.
[0048] In FIG. 4 , there is illustrated a partial cross sectional view of a representative embodiment of the pump head 114 of the invention. As depicted here, housing 109 contains transmission and stroke adjustor assembly 90 . Further depicted are diaphragms 106 a and 106 b , connected to shafts 12 a and 12 b , respectively, of the transmission and stroke adjustor assembly 90 . As will be further discussed in detail below, a prime mover such as an electric motor, hydraulic motor or the like is operatively connected to the transmission and stroke adjust assembly 90 to rotatably drive shaft 58 of the transmission which, through the transmission, causes the reciprocation of shafts 12 a and 12 b , and thus also the reciprocation of diaphragms 106 a and 106 b that are connected thereto.
[0049] With initial reference to FIGS. 5 a and 5 b , there is representatively illustrated cross sectional views reciprocating pumps 101 a and 101 b , wherein pump 101 a is illustrated in FIG. 5 a and pump 101 b is illustrated in FIG. 5 b . Each pump 101 a and 101 b there is a liquid flow channel 138 a , 138 b that has a seating area 132 a , 132 b across which diaphragms 106 a , 106 b are disposed, an inwardly flow check valve 102 a , 102 b disposed across fluid suction inlet 150 a , 150 b , and an outwardly flow check valve 102 c , 102 d disposed across fluid discharge 152 a , 152 b . The reciprocation of diaphragms 106 a , 106 b with respect to seating area 132 a , 132 b results in a fluid pumping action from suction inlet 150 a , 150 b through flow channel 138 a , 138 b and out fluid discharge 152 a , 152 b . This pumping action has been long established in the field of the invention and is readily understood by one skilled in the art. Accordingly, a more detailed explanation of the physics and related structure permitting this pump action is not warranted here.
[0050] Further illustrated in FIGS. 5 a and 5 b , and subsequently in FIGS. 6 a and 6 b , are various positions of diaphragms 106 a , 106 b through a single stroke action. In FIG. 5 a , diaphragm 106 a is shown in a “Full Suction” position, and in FIG. 5 b , diaphragm 106 b is shown in an opposite “Full Stroke” position. In FIG. 6 a , diaphragm 106 a is shown in a “Full Stroke” position, and in FIG. 6 b , diaphragm 106 b is shown in the opposite “Full Suction” position. At the full suction position diaphragm 106 a , 106 b is at the momentary end position of P 3 . At the full stroke position diaphragm 106 a , 106 b is at the momentary end position of P 2 . At these two positional moments P 2 and P 3 diaphragms 106 a , 106 b will not have any motion. These two positions can be termed bottom dead center and top dead center respectively. These are the cross over positions where the diaphragms 106 a , 106 b change their direction of reciprocating motion. This change in reciprocating motion for each diaphragm is phased to happen at the same moment in time. When diaphragm connector shafts 12 a and 12 b respectively reciprocate their diaphragms 106 a , 106 b they will do so with substantially constant velocity of motion. Diaphragms 106 a , 106 b will move substantially uniform velocity between positions P 2 and P 3 and between P 3 and P 2 . The transmission and stroke adjustment assembly 90 utilizes a conjugate three dimensional cam that can create various characterized reciprocating motions. To this end, diaphragms 106 a , 106 b have near substantial uniform motion. They will have constant motion between positions P 2 and P 3 and P 3 and P 2 , but the velocity will moderately vary between these positions of no momentary displacement. For example there can be some rate in velocity change at both ends of the displacing cycle for each diaphragm as noted in FIG. 19 . As the examples of volumetric displacement V 3 and V 4 depict. The displacement gap between V 3 and V 4 is so small that the liquid being pumped across the pump 114 never comes to zero velocity. That is the liquid approaching the pump and discharging the pump has sustained motion at all times. The pumped liquid will have sustained motion, but not absolute constant velocity. These forms of reciprocating motion as described with proper phasing of the diaphragms 106 a , 106 b is accomplished by the invention. This assures the invention shall keep the liquid pumped in sufficiently constant motion during its operation.
[0051] Turning to FIGS. 7 a and 7 b , diaphragms 106 a , 106 b are representatively illustrated in an operation state wherein both diaphragms are simultaneously positioned at P 1 . In this position, diaphragms 106 a , 106 b are fully seated within each of their respective reciprocating pump 101 a , 101 b and prevent fluid from leaking or siphoning across the pump. This is a safety feature that can be manually done by the proper manual rotation of stroke adjustor knob 104 . It can also be an automated feature if the invention is an automated version.
[0052] The transmission and stroke assembly 90 of pump 114 utilizes aspects of co-pending U.S. patent application Ser. No. 13/084,086, the entirety of which is incorporated herein by reference. In FIGS. 8 through 11 , there is illustrated a conjugate cam 50 reflecting the principles of the aforementioned U.S. patent application. The eccentric three dimensional conjugate cam 50 includes two integrated elongated cams 52 and 54 . The surface areas are integral thrust washer 48 of the cam assembly 50 . The cam assembly 50 has an internal full axial hole 56 with spline grove lines 57 through its center. It is parallel to center line 36 . The cams 52 and 54 each have a surface profile 53 with a length of each cam of “Y”.
[0053] Each cam 52 and 54 are congruent geometries that are properly integrated to create a conjugate cam assembly 50 . The cam surface areas 53 of cams 52 and 54 have an area along the dimension “Y” that is expanded from a position of no displacement to maximum displacement to one direction along “Y”. To the opposite direction from a position of no displacement for both cams 52 and 54 begins a tapered outward area 107 about the center 36 . These two tapered areas 107 expand their surface areas 53 and gradually expand to approach the surface areas 112 for each congruent cam 52 and 54 . The cams 52 and 54 circular surface areas 112 are expanded surface areas about the center 36 . This surface area of 112 for each cam 52 and 54 shall have a radius greater than the most eccentric position along the cam profile 53 . These surface areas 112 expand the FIG. 12 cam follower 82 halves 82 a and 82 b to cause the diaphragms 106 a , 106 b to seat in their respective reciprocating pump 101 a , 101 b at internal surface area 132 a and 132 b , as illustrated in FIGS. 7 a and 7 b . The seating will be at position P 1 .
[0054] FIG. 10 is a three dimensional conjugate cam 50 that is fitted over and mates to its drive shaft 58 . There is a high tolerance clearance between the axial hole 56 of the three dimensional cam assembly 50 to its mated splined cam drive shaft 58 . The drive shaft 58 has raised splines 59 that integrate into the cam assemblies splined groves 57 . This creates an integrated rotationally relationship and an aligned movable lateral motion relationship of the three dimensional cam assembly 50 to its mated cam drive shaft 58 . The splined drive shaft 58 has a drive gear 62 . It will mate with drive gear shaft 116 as shown in FIG. 12 . There are example positional points for three of the four sphere bearings 84 a or 84 b . The bearings 84 a and 84 b are at positions with respect cams 52 and 54 where they are initially tangential to the inclined area 107 . They are positional at tangents 44 to the two cams 52 and 54 and the incline area 107 . The drive shaft 58 , cam assembly 50 and drive gear 62 comprise the shaft driven three dimensional cam assemblies 50 as an assembly 92 .
[0055] FIG. 11 is the cam assembly 50 with the four spherical bearings of two 84 a and two 84 b . These bearings have their centers intersecting to the two planes 100 , one sphere bearing center 84 a and 84 b each plane 100 as shown. The plane 100 is defined as the intersecting point of the center of the sphere bearings 84 a and 84 b . The drawing depicts spherical bearings, but other designs can be used such as rollers. There are limitations to the load that spheres can bear. For higher force applications the sphere bearings can be substituted for roller followers. The rollers and their support mechanisms are not depicted. If the roller followers were deployed they would have to be allowed to freely pivot to stay parallel to the cam profiles 53 . In addition, FIG. 11 depicts a tapered circular area 107 and a circular area of 112 for about center line 36 for each cam 52 and 54 . This is an option to cause the diaphragms 106 a , 106 b to expand outward to seat to a mating position in their respective reciprocating pump 101 a , 101 b . This pump hydraulic sealed position is sustained whether the pump is running or shut-off. The cam assembly 50 is laterally moved back to allow bearings 84 a and 84 b form tangents with the each cam eccentric portion of 52 and 54 and the stroke creation will begin again.
[0056] FIG. 12 is an exploded view of the modular cam mechanism assembly 90 . Only the pertinent components are shown, there are some ancillary components not depicted to provide a better view of the more critical components. The drive shaft 58 is supported by bearings 64 . These bearings 64 are held in the cam assembly frame 68 . The conjugate cam assembly 50 is positional held by the stroke adjustor frame 70 . The stroke adjustor frame 70 has two perpendicular arms 72 that are in positional contact with thrust washers 48 of the cam mechanism 50 . The stroke adjustor rod 76 is connected to stroke adjustor frame 70 at threaded holes 74 and locked in place by nut not shown. The threads of 74 and 76 are not detailed. The stroke adjustor rod 76 is aligned and held to the cam assembly frame 68 by alignment linear bearing area 80 the actual bearing is not detailed only the hole is shown. When the stroke adjustor frame 70 is held in place within the cam assembly frame 68 the rod 76 and cam assembly frame 68 is constrained and aligned to allow for lateral motion only.
[0057] The stroke adjustor frame 70 , stroke adjustor rod 76 and arms 72 comprise the stroke adjustor assembly 94 that fits into the cam assembly frame 68 . The cam stroke adjustor shaft 76 has a drive gear 121 . That drive gear has internal threads 123 not detailed. Gear 121 interacts with a worm gear and shaft 119 . The stroke adjustor knob 104 not shown is connected to the shaft 119 . The cam assembly 50 , drive gear 62 and the motor drive shaft 58 comprise the major components for the driven cam assembly 92 . The drive shaft gear 62 meshes with the worm gear drive shaft 116 . The worm gear drive shaft is connected to the drive motor (not shown) that is mounted to motor flange mount 105 not shown. There would be some form of coupling between 116 and the motor shaft not shown. The follower assembly 88 is comprised of 82 a and 82 b of 82 , diaphragm drive shafts 12 a and 12 b , spherical bearings two 84 a and two 84 b , springs 127 and four bolts 96 . In addition the sphere bearings 84 a and 84 b shown as detail “D” are constrained by contact to small ball bearings 126 that are held in place the flat bearing race 125 . That is held in place by flanged diaphragm shafts 12 a and 12 b . This supports the sphere bearings 82 a and 82 b and allows them to rotate.
[0058] The follower holder assembly 82 has two pieces 82 a and 82 b . The holder assembly 82 confines the four bearings of two pairs of 84 a and 84 b . When the bolts 96 attach the two cam follower haves 82 a and 82 b the four bolts 96 pass through springs 127 through both 82 a and 82 b and 12 a and 12 b . There are four or eight springs 127 depending on design and are held in compression between each cam follower plates 12 a or 12 b and the head of bolt heads 96 and their nuts (not shown). Certain designs may incorporate external springs to accomplish the same effect of springs 127 . This configuration maintains the sphere bearings 84 a and 84 b to stay in contact with the cam surface 50 . The sphere bearings 84 a and 84 b are mechanical connected to each cam follower half 82 a and 82 b that is positively connected to flanged diaphragms shafts 12 a and 12 b . This is true when each cam follower 82 a or 82 b is expanding away from the center 36 and a diaphragm 106 is displacing. When a diaphragm 106 is in return and creating a cavity the spring 127 forces have to be sufficient to pull back the diaphragms 106 as if 12 a or 12 b were joined rigid. That is that the follower 82 was one solid piece. The springs 127 allow for manufacturing tolerances and to allow the diaphragms to be expanded outward during hydraulic shut-off. As depicted in the drawings the spherical ball 84 a and 84 b are incorporated in this design, but it can be of a different design, such as rollers. The spherical geometry is the simplest to design, but may have practical design limitations that a cylindrical roller would solve. The follower assembly holder 88 encapsulates the cam assembly 50 .
[0059] The cam follower assembly 88 is continuously constrained by its tangents 44 to the surface area profiles 53 of the conjugate cams 52 and 54 . The cam follower assembly 88 is further constrained by the connector shafts 12 a and 12 b being held in rigid alignment within the linear bearings 64 . This combination of two defined mechanical constraints holds the cam follower 88 assembly in proper position. As shown on FIG. 20 assemblies 88 , 92 , 94 and cam assembly frame 68 with its bearings 64 comprise the cam assembly mechanism 90 .
[0060] FIG. 13 is a drawing of the cam assembly 50 on its splined drive shaft 58 . The drive shaft 58 is supported by bearings 64 . The cam drive gear 62 hidden is connected to drive shaft 58 . The sphere bearings 84 a and 84 b are shown without the cam follower assembly 82 . The cam drive shaft with worm gear 116 that then goes up through the motor flange 105 that would then be connected to a drive motor not shown. The gears 62 and 116 interact to cause the motor rotation to be transferred to the drive shaft 58 that is then applied to the cam assembly 50 . The stroke adjustor knob 104 is connected to the worm drive shaft 119 that engages gear 121 . The 121 gear has internal threads 123 not shown, that engages with the threads on the stroke adjustor shaft 76 . The stroke shaft 76 is supported by bearing area 80 as shown in FIG. 12 . The gear 121 is positional constrained by two nuts washers 95 that are to either side of gear 121 . This allows the rotation of gear 121 to cause the lateral motion of stroke adjustor frame 94 . The rotation of gear 121 and its internal threads 123 to shaft 76 drives the shaft 76 lateral in both directions.
[0061] FIG. 14 is an inverted cut away view of the driven cam assembly with its shaft and stroke adjustor for overall assembly 90 . The cut away view shows a diaphragm 106 and the motorized worm gear drive shaft 116 . The drawing depicts the engagement of the drive shaft gear 62 and the geared stroke adjustor shaft 119 .
[0062] FIG. 15 is an additional inverted cut away view of the complete cam mechanism and stroke adjustor assembly 90 without diaphragms 106 . As compared to FIG. 14 it adds the stroke adjustor worm gear shaft 116 that is engaged with gear 121 .
[0063] FIGS. 16 and 17 are additional views of the cam assembly with drive gears, stroke adjustor assembly as assembly 90 . It has the drive gearing for the stroke adjustor mechanism and for driving the cam assembly. It shows the diaphragms 106 and the disengagement section 130 of diaphragm drive shafts 12 a and 12 b as per Detail “E”. This is where the shafts 12 a and 12 b are split and are joined. This section is where each shaft 12 a and 12 b interacts and can be coupled or uncoupled. The hole 131 accommodates a through bolt and nut not shown or it is threaded section for a bolt. The bolt or pin not shown would allow for the engaging and disengaging of diaphragms 106 a , 106 b on either side of the pump 114 . All pumps of common art will have some form of mechanical connection between its diaphragm and diaphragm drive shaft. There are no known pumps that are designed to allow this as a field addition. The invention is so designed that it can built as a single headed diaphragm pump and allow for the addition of a pump head 101 and its diaphragm 106 to be added in the field. This is achieved with the rated volumetric liquid displacement specified and at its stated accuracy for the invention. This also allows for a single headed pump to ship as a left hand or right hand pump. The preferred side of pump head can be changed in the field. This also allows for a duplex pump to operate with only one diaphragm 106 in a pump housing 101 engaged. That is the other diaphragm 106 in the second pump housing 101 in place, but disengaged and not displacing.
[0064] FIG. 18 is a top view of the pump 134 with only one pump housing 101 as compared to the duplex pump 114 . A pump housing 101 can be mounted to either side of the pump 134 . Cap 128 is to cover the pump shaft 12 a or 12 b for safety and to keep the pump gear housing 109 sealed. The diaphragm pump shafts 12 a and 12 b will always be reciprocating on the both sides of the transmission housing 109 . This is true even though the pump is built with one pump housing 101 . The seal cap 128 can be removed and a pump housing 101 can be added to change the pump to a duplex pump 114 . The additional pump housing 101 to be added will have the engagement section 130 connected. The engagement section 130 as shown in Detail “E” will have a through bolt or pin incorporated through hole 131 when a second diaphragm 106 is added. It should be noted that as a single headed pump it will create non-continuous pulsating flow rates.
[0065] FIG. 19 is an illustration of examples for two liquid volumetric displacements at two given stroke lengths (50% and 100%) and at a constant rotational speed for a duplex pump. Where V 1 is the theoretical volumetric displacement for assigned diaphragm D 1 and V 2 is the theoretical volumetric displacement for assigned diaphragm D 2 . Whereas the flow rate for V 1 and V 2 have substantially constant velocity of displacement respectively created by D 1 and D 2 . That is due to the substantially uniform or constant velocity of reciprocating motion for D 1 and D 2 . The volumetric displacements of V 1 and V 2 by diaphragms D 1 and D 2 are theoretical and the actual volumetric liquid displaced may have a small difference. They could be closer to V 3 and V 4 or some other curve of displacement. The invention's conjugate cam can be designed to create other forms of volumetric displacement such as V 3 and V 4 may be optimal. The invention is so designed that the peak liquid displacement velocities are minimized. For example the displacement curves of V 1 and V 2 do not have the peak velocities that a sinusoidal displacement would create over the same time constant. The phasing of the diaphragms D 1 and D 2 is such that the volumetric displacement across the pump is continuous. The volumetric displacement across the pump needs to be substantially continuous, but will have some variations of displacement velocities. The volumetric displacements of V 3 and V 4 are examples of sufficient sustained displacement with less than perfect constant velocity. In additions the actual design mechanics and hydraulic issues can cause different displacement curves. It is a matter of acceptable amounts of very low pulsating flow rates by the invention. The non-continuous displacement of V 1 by diaphragm D 1 creates an undesirable intermittent pulsating flow rates as defined by V 0 . Whereas V 0 is when the diaphragm is in a suction cycle and is not displacing liquid. The non-continuous displacement of V 2 by diaphragm D 2 creates an undesirable intermittent pulsating flow rates as defined by V 0 . Whereas V 0 is when the diaphragm is in a suction cycle and is not displacing liquid. The gap between the displacing and non-displacing for each diaphragm is V 0 . The cycle rate of the displacement C is 360° of rotational operation. That is the 360° cycle rate C is repeated as C+C 2 +C 3 continuous during the invention's rotational operation. As mentioned each displacement V 1 and V 2 are phased as to substantially assure that one is displacing while the other is in suction. This phasing is such that the volumetric displacement is typically split 180° to each diaphragm D 1 and D 2 . The combined volumetric liquid displacements of V 1 +V 2 have resultant properly phased alternating flow rates as V 1 +V 2 =Q 3 . The substantially continuous flow rate of Q 3 creates substantially desirable continuous non-pulsating flow rates by the invention. A critical and unique feature of the invention is how stroke length is changed. If the pump was operating at the same speed as Q 3 , but at 50% of maximum stroke length then V 5 and V 6 would be 50% of V 1 and V 2 . The continuous flow rate Q 4 would be 50% of Q 3 . The pump creates substantially continuous uniform reciprocating displacement motion with resultant continuous non-pulsating flow rates. The stroke adjusting mechanism combined with the invention's conjugate three dimensional cam assembly substantially assures Q 3 is as described. That is continuous uniform flow rate generation that can be equally proportionally changed by its stroke length change For any given stroke length position the output flow rate would be substantially uniform to a given rotational speed.
[0066] Operationally when the Pump's motor not shown rotates the worm gear drive shaft 116 it turns the geared drive shaft 62 that in turn rotates its integral drive shaft 58 that in turn rotates the cam assembly 50 . The shaft 58 and the cam assembly 50 are constrained to rotate together due to their splined relationship of 57 and 59 . The follower assembly 88 is encapsulating the cam assembly 50 to assure constant tangents of the sphere bearings 84 a and 84 b to cam assembly 50 . The cam assembly 50 is free to laterally move on shaft 58 . The rotation of the cam assembly 50 will impart the reciprocating motion to the follower assembly 88 . This reciprocating motion would be prescribed by the conjugate cam's 52 and 54 profiles 53 . That is the resultant tangents of sphere bearings 84 a and 84 b at that cam profile 53 at planes 100 will impart a prescribed reciprocating motion to the follower 88 . The theoretical planes 100 move lateral with the centers of bearings 84 a and 84 b . The form of reciprocating motion will be as described herein this writing. The motion will be transferred to the diaphragm shafts 12 a and 12 b . In turn transferred to the diaphragms 106 . As the motor drives the invention each diaphragm 106 creates batch displacement. The properly phased summation of the two batch displacements will create very low or non-pulsating continuous liquid flow rates. The pump 114 liquid displacement will be as shown and described in FIG. 19 . The pumps 114 and 134 have an integral stroke adjustor assembly 94 as shown in FIGS. 12 and 13 . As shown in FIG. 13 , when the stroke adjustor knob 104 (the stroke adjustor knob can be substitute for a motor not shown) is rotated it turns the stroke adjustor worm gear shaft 119 that turns gear 121 that has internal threads 123 that engage the stroke adjustor shaft 76 threaded section that causes the shaft 76 to move laterally moving the stroke adjustor frame 70 . This moves the stroke adjustor assembly 94 . The frame 70 has two arms 72 that are in contact with the cam assembly 50 at washer areas 48 . The cam assembly 50 in turn is driven lateral to either direction when the stroke adjustor assembly 94 moves. This changes the positional relationship between the cams 52 and 54 surface areas 53 and the follower's sphere bearings 84 a and 84 b . That in turn changes the stroke length and the resultant displacement by each diaphragm 106 a , 106 b . This method of lateral motion of the cam assembly 50 can move the bearings 84 a and 84 b to cam surface area 107 a tapered incline area to a circular area 112 . FIGS. 7 a and 7 b shows when the bearings 84 a and 84 b are riding on the surface area 112 the diaphragms 106 a , 106 b will be forced to expand outward and cause the face of each diaphragm 106 a , 106 b to seat within each pump housing 101 a , 101 b . When the follower bearings 84 a and 84 b are riding on the surface areas 107 or 112 the follower assembly haves 82 a and 82 b will expand apart. The springs 127 will allow the expansion, but keep the bearings 84 a and 84 b to stay in contact to areas 107 or 112 . As per FIGS. 7 a and 7 b , when the diaphragms 106 a , 106 b are in position P 1 the liquid cannot leak across the pump 114 or 134 . This can be manually or automatically done depending on the pump configuration. This hydraulic shut-off position can be changed back to displacing by moving the cam assembly 50 to the opposite direction. The shut-off can be maintained even if the motor is running There are other minor ancillary components required to have a properly operating system not described. The volumetric displacement can also be change by changing the speed of the motor as is common to the state of art metering pumps. There is a section of the diaphragm shafts 12 a and 12 b that are split as shown in detail “E” on FIG. 16 . This split section 130 of the diaphragm shafts 12 a and 12 b has a hole 131 that accommodates a pin or bolt that connects the shaft. This is a form of coupling can be automated as well, but not described within. This ability to couple the diaphragms 106 a , 106 b is incorporated to allow a single headed pump 134 ( FIG. 18 ) to add a pump housing 101 in the field by a user of the pump to double the capacity of pump and create a duplex pump 114 . The cap 128 is removed with the pump 134 powered off to allow a new pump housing 101 to be bolted on with bolts 113 . The proper piping installations would be added and the pump turned back for doubling of the pump flow rate capacity. It also allows the user to change the side that the pump housing 101 is connected to the transmission housing 109 . This feature can also be done in the field.
[0067] From the above description advantages of embodiments of the invention herein are readily recognized by those skilled in the field of the invention. Alternative embodiments are possible. In an alternative embodiment, conventional prime mover control electronics and prime mover control methods may be employed. In such an embodiment, the stroke control of the diaphragms may be automated by replacing the control knob 104 with an electric motor that is interfaced with the prime mover control electronics. To this end, the stroke length may be adjust remotely in a similar manner to conventional methods of remotely controlling the prime mover through the control electronics and an established communication link between the control electronics and a remotely located controller or computer interface. In another alternative embodiment, the diaphragms could be replaced with pistons or other reciprocating displacement mechanisms. In another alternative embodiment, three or reciprocating pump containing displacers (diaphragms, pistons, or the like) may be phased about the pump in order to overlap suction and discharge phases, e.g. to have 240° of suction and 120° of discharge for each diaphragm. It would be provide continuous non-pulsating flow rates. It can be built as a four diaphragm pump for additional capacity with the same features as the duplex embodiment. Other embodiments are also possible within the scope of the invention and the claims. | A fluid metering pump is provided having reciprocating pumps including a first fluid displacer and a second reciprocating pump include a second fluid displacer. A transmission and stroke adjuster assembly for couples a prime mover to each of said first and said second fluid displacers and converting a rotary movement of the prime mover into a reciprocating stroke movement of said first and said second fluid displacers resulting in a continuous fluid flow free of fluid pulsing. | 5 |
BACKGROUND OF THE INVENTION
This invention is a method for ranking politically exposed persons (“PEPs”) and/or other persons and entities that pose a heightened compliance, legal, regulatory, and reputation risk to financial institutions (e.g. known and suspected criminals and their associates) based on their centrality or “importance” within certain graph representations of the watch list databases in which are profiled. The rankings provide for an objective measure of the underlying risk posed by individual PEP's and other heightened-risk entities relative to others in the same watch list database source. The invention is considered to be particularly useful to financial institutions in screening potential and existing clients.
In the international financial industry, there is a general consensus that senior political figures, along with their family members and known close associates, collectively referred to as “Politically Exposed Persons” or “PEPs”—represent an inherent heightened risk given their direct or indirect access to public funds and influence over the business and commercial affairs in their jurisdictions. Consequently, most financial institutions are counseled, and in many cases required, to mitigate the risk of becoming wittingly or unwittingly complicit in the furtherance of political corruption by performing the following steps: 1) proactively identifying customers who are PEPs, 2) comprehensively assessing the acceptability of the specific risk they pose and, 3) if deemed to pose an acceptable risk, placing their accounts under continuing heightened scrutiny and periodic re-assessment.
For the first step, proactive identification, many financial institutions automatically screen their client databases against subscription-based commercial PEP watch list databases that are themselves compiled from public sources such as government, law enforcement and news media websites. Many of these databases, since coming into being, have augmented their coverage beyond PEPs to include other categories of risk (e.g. fraud, money laundering, narcotics crime, terrorism, etc.) and are often referred to as “PEP/KYC databases” (“KYC” is an acronym for “Know Your Customer”, industry parlance for general customer due diligence policies). Records of related persons and entities in PEP/KYC databases typically link to one another.
The screening of large target client databases against large source PEP/KYC databases inevitably leads to the problem of false positive matches given the public nature of the source data; PEP/KYC database records rarely provide unique identifiers such as social security numbers and often do not provide strong ones such as date of birth. Thus, most matches are generated based solely on the similarity between target and source names and can be properly viewed only as a starting point for investigating whether the two matching names represent the same person or entity.
In wide-recognition of the infeasibility of investigating all potential matches, there is a consensus in favor of a risk-based approach where priority is given to matches against the highest-risk PEP/KYC records. Such an approach requires some method for grouping or ranking PEP/KYC records by risk. The conventional method makes use of the various category and attribute fields available in records such as risk type (e.g. PEP, fraud, narcotics, terrorism), political position (e.g. Presidents, Governors, Mayors) and country of origin to create risk groups (e.g. Presidents from Countries X and Y are a high-risk group; Mayor from Country Z, a low-risk one). A related variant is a rudimentary risk scoring scheme where category values are assigned scores (e.g. Presidents=3, Governors=2, Mayors=1, Country X=3, Country Y=2, Country Z=1) that are aggregated to derive profile scores (e.g. Presidents from Country X=3×3=9, Mayors from Country Z=1×1=1).
These top-down, category-based methods come in infinite varieties but operate from the same overly simplistic premise: namely that the level of risk that best characterizes a general class of PEP/KYC records adequately characterizes each individual member of that class. Local officials from highly developed countries, for example, may be best characterized as low risk as a general class. It does not follow, however, that each individual local official from a highly developed country is adequately characterized as low risk. It certainly does not adequately characterize the local official, for example, who happens to be the related to a prominent national political figure or notorious criminal or who is reported in the news to be under suspicion for corruption.
The example above alludes to a more useful alternative approach where PEP/KYC records are not evaluated based on their membership to a general class (e.g. local officials) but based on their particular connections to relevant entities (e.g. ties to a prominent national figure or a notorious criminal, or a news article on corruption).
SUMMARY OF THE INVENTION
The present invention is a method of measuring the importance imparted to each member of a population of persons by having a relationship with at least one other member of the population and/or being affected by at least one exposure factor. According to the method, an identifier is assigned to each member of the population of politically exposed persons. A designator is assigned to each exposure factor having an effect on at least one of the members of the population of politically exposed persons. An exposure index is then derived for each member of the population of politically exposed persons and for each exposure factor. The exposure index is a recursive function of the exposure indexes derived for each of the respective other members of the population of politically exposed persons having a relationship with the member, and of the indexes derived for each of the exposure factors having an effect on the member. The exposure factors may include one or more of the following: political position of the member, geographical jurisdiction in which the member resides or operates, and source of published information which mentions the member. The list of the members is sorted in order of derived exposure index and then filtered to provide a subset of the members of the population who present the greatest risk.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a tabular description of a population of politically exposed persons;
FIG. 2 is a graphical view of the relationships among the politically exposed persons described in FIG. 3 ;
FIG. 3 is a graphical view of the relationships between the politically exposed persons described in FIG. 1 and sources of information which mention one or more of the politically exposed persons listed in FIG. 1 .
FIG. 4 is a graphical view of the relationships between the information sources described in FIG. 1 that are connected by virtue of co-citing same the politically exposed persons listed in FIG. 1 .
FIG. 5 combines the graphs of FIGS. 2-4 . into a single graph
FIG. 6 is a tabular description of the ranking of a population of politically exposed persons;
FIG. 7 is a mathematical flow diagram illustrating the logic of the method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While PEP/KYC databases are typically created, stored and used in tabular format, they can be represented as a series of interconnected graphs. These graphs can be divided into three distinct types: 1) a regular social graph where PEP's are nodes connected by explicit social relationships 2 ) a binomial graph where PEPs are one class of nodes and one or more exposure factors (e.g. information sources, political positions) are the other class and 3) a graph where exposure factors are nodes connected to each other by virtue of being connected to the same PEP.
To illustrate the above, a database table listing a population of politically exposed persons is illustrated in FIG. 3 . The database may be stored on a computer-readable medium such as a magnetic disc as will be known by those skilled in the art. While typical PEP/KYC databases contain hundreds of thousands to millions of records, for simplicity, this population consists of only six.
In the table, a record for John Doe indicates that he is a mayor of a city in the United States and that his wife is Jane Doe and father-in-law is Tom Smith. This information was found on website entitled “Mayors.com” and “News.com.” Jane Doe is also listed as a politically exposed person by virtue of having a relationship with husband, John Doe, and father, Tom Smith. Although not an officeholder, Jane Doe is mentioned in her capacity as being a family member of officeholders on the websites entitled Mayors.gov and News.com.
Richard Roe is also listed as a mayor of a U.S. city by the source Mayors.gov but is not listed as having any relationships.
Tom Smith is listed as a senator in the U.S. and as having four relationships: John and Jane Doe, his daughter and son-in-law, and Dick and Harry Smith, his two brothers. This information was found on two websites: Senate.gov and News.com. Finally, Dick and Harry Smith are listed as PEPs due to their relationship to their brother, a senator, and in the Fraud category due to criminal convictions as mentioned in the Justice.gov source.
FIGS. 2-5 are graphical representations of the relationships contained in FIG. 1 . FIGS. 2-4 represent individual graphs that correspond to the three types of graphs described above. Note in FIG. 4 that the information sources Mayor.gov and News.com are connected because they are both sources for John Doe and that Senate.gov and News.com are connected because they are both sources for Tom Smith. Similarly, Justice.gov and News.com have two connections as they are both sources for Dick and Harry Smith. FIG. 5 illustrates the three previous separate graphs as a combined, interconnected one.
The interconnected graph allows an “Exposure Index” or “EI” or risk score for each PEP and exposure factor to be calculated in a recursive fashion based on the Exposure Index of the PEPs and exposure factors connected to a given PEP or exposure factor.
In one preferred embodiment, the recursive Exposure Index can be found by solving the following system of linear equations derived from the graph representation of a PEP/KYC database:
x
i
=
α
(
∑
j
=
1
m
a
ij
x
j
a
j
+
∑
k
=
1
n
b
ik
y
k
b
k
)
y
k
=
β
(
∑
i
=
1
m
b
ki
′
x
i
b
i
′
+
∑
l
=
1
,
≠
k
n
c
kl
y
l
c
l
)
Where:
x i is the EI of the ith profile in a set of m profiles x;
y k is the EI of the jth profile in a set of n profiles y;
a ij =a ji =1 if there is a link between profile i and profile j, otherwise a ij =a ji =0.
a j = ∑ i = 1 m a ij ,
i.e., the total number of profiles linked to profile j.
b ik =b′ ki =1 if there is a link between profile i and source k, otherwise b ik =b′ ki =0.
b k = ∑ i = 1 m b ik , b i ′ = ∑ k = 1 n b ki ′ ,
i.e., the total number of profiles linked to source j and the total number of sources linked to profile i, respectively.
c kl = ∑ i = 1 m b ki ′ b il ,
i.e., the number of profiles which link to both source k and source l.
c l = ∑ l = 1 , ≠ k m c kl ,
i.e., the total number of profiles which link to both source k and another source l for all source l not equal to k.
0≦α,β≦1 and α+β=1
Using the given example and assuming α=β=0.5, the system of equations becomes:
E
I
(
JohnDoe
)
=
.5
*
(
E
I
(
JaneDoe
)
/
2
+
E
I
(
TomSmith
)
/
4
)
+
.5
*
E
I
(
Mayors
.
gov
)
/
2
+
(
E
I
(
News
.
com
)
/
5
)
E
I
(
JaneDoe
)
=
.5
*
(
E
I
(
JohnDoe
)
/
2
+
E
I
(
TomSmith
)
/
4
)
+
.5
*
(
E
I
(
News
.
com
)
/
5
)
E
I
(
RichardRoe
)
=
.5
*
(
E
I
(
Mayors
.
gov
)
)
E
I
(
TomSmith
)
=
.5
*
(
E
I
(
JohnDoe
)
/
2
+
E
I
(
JaneDoe
)
/
2
+
E
I
(
DickSmith
)
/
2
+
E
I
(
HarrySmith
)
/
2
+
.5
*
(
E
I
(
Senate
.
gov
)
+
E
I
(
News
.
com
)
/
5
)
E
I
(
DickSmith
=
.5
*
(
E
I
(
TomSmith
)
/
4
+
E
I
(
HarrySmith
)
/
2
)
+
.5
*
(
E
I
(
News
.
com
)
/
5
+
E
I
(
Justice
)
/
2
)
E
I
(
HarrySmith
=
.5
*
(
E
I
(
TomSmith
)
/
4
+
E
I
(
DickSmith
)
/
2
)
+
.5
*
(
E
I
(
News
.
com
)
/
5
+
(
E
I
(
Justice
)
/
2
)
E
I
(
Mayors
.
gov
)
=
.5
*
(
E
I
(
JohnDoe
)
/
2
+
E
I
(
RichardRoe
)
)
+
.5
*
(
E
I
(
News
.
com
)
/
4
)
E
I
(
News
.
com
)
=
.5
*
(
E
I
(
JohnDoe
)
/
2
+
E
I
(
JaneDoe
)
+
E
I
(
TomSmith
)
/
2
+
E
I
(
DickSmith
)
/
2
+
E
I
(
HarrySmith
)
/
2
)
+
.5
*
(
E
I
(
Mayors
.
gov
)
+
E
I
(
Senate
.
gov
)
+
E
I
(
Justice
.
gov
)
)
E
I
(
Senate
.
gov
)
=
.5
*
(
E
I
(
TomSmith
)
/
2
)
+
.5
*
(
E
I
(
News
.
com
)
/
4
)
E
I
(
Justice
.
gov
)
=
.5
*
(
E
I
(
Dick
Smith
)
/
2
)
+
E
I
(
Harry
Smith
)
/
2
)
+
.5
*
(
2
*
E
I
(
News
.
com
)
/
4
)
Typically, it is easier to express and solve system of linear of equations in matrix form:
x
y
=
α
A
α
B
β
B
′
β
B
x
y
The example becomes:
x
1
x
2
x
3
x
4
x
5
x
6
y
1
y
2
y
3
y
4
=
0
.25
0
.125
0
0
.25
.1
0
0
.25
0
0
.125
0
0
0
.1
0
0
0
0
0
0
0
0
.25
0
0
0
.25
.25
0
0
.25
.25
0
.1
.5
0
0
0
0
.125
0
.25
0
.1
0
.25
0
0
0
.125
.25
0
0
.1
0
.25
.25
0
.5
0
0
0
0
.125
0
0
.25
.5
0
.25
.25
.25
.5
0
.5
.5
0
0
0
.25
0
0
0
.125
0
0
0
0
0
0
.25
.25
0
.25
0
0
x
1
x
2
x
3
x
4
x
5
x
6
y
1
y
2
y
3
y
4
The above yields the following solution:
x
1
x
2
x
3
x
4
x
5
x
6
y
1
y
2
y
3
y
4
=
0.75
0.64
0.15
1.46
0.98
0.98
0.59
2.60
0.69
1.15
Which, in turns, yields the rankings of FIG. 6 . Of particular note is the difference in rank between John Doe and Richard Roe. Both are mayors of U.S. cities and would receive the same ranking in many prior art systems. However, this invention credits John Doe with the additional risk inherent in being married to the daughter of a Senator who, in turn, is a brother of two convicted criminals.
It must be pointed that it is only due to the small size (i.e. six PEPs) of this example that the solution to above equation could be calculated directly. In real world situations where there are hundreds of thousands or millions of PEP's, other heightened risk entities and exposure factors, the solution must be arrived at iteratively through successive approximation after making an initial arbitrary guess (i.e. a vector of all ones) as follows:
x
0
y
0
=
1
m
1
n
⇒
x
n
+
1
y
n
+
1
=
α
A
α
B
β
B
′
β
B
x
n
y
n
The above is based on the convergence of an infinite sequence until the difference between the last term of the sequence and the preceding term is less than or equal to a predetermined small number, ε:
x
y
=
lim
n
→
∞
α
A
α
B
β
B
′
β
B
n
x
n
y
n
FIG. 7 illustrates a flow chart of this iteration process.
Exposure factors are not limited to sources but may include one or more of the following: political position of the member, geographical jurisdiction in which the member resides or operates, and source of published information which mentions the member. Each exposure factor to which a PEP is related adds another component to the exposure index for the PEP. In addition, although the method of the invention does not require that sources of risk be weighted relative to one another as is done in the prior art, the present invention can take into account a priori estimates of relative risk. For example, when the exposure index of PEPs is based on exposure to other PEPs, categories/positions, and country of residence, and it is desired to include an a priori estimate of risk such as Transparency International's corruption perception index which ranks countries in accordance with their perceived levels of corruption, the exposure index can be calculated from the following:
x
i
=
1
3
(
∑
j
=
1
m
a
ij
x
j
a
j
+
∑
j
=
1
n
b
ij
y
j
b
j
+
∑
k
=
1
p
∑
l
=
1
q
c
i
l
k
z
k
l
c
k
l
)
y
j
=
1
3
(
∑
i
=
1
m
b
ji
′
x
i
b
j
′
+
∑
k
=
1
,
≠
j
n
(
∑
i
=
1
m
b
ji
′
b
ik
)
y
k
b
′
b
k
+
∑
k
=
1
p
∑
l
=
1
q
(
∑
i
=
1
m
b
ji
′
c
i
l
k
)
z
k
l
b
′
c
k
l
)
z
k
l
=
1
3
(
∑
i
=
1
m
c
k
l
′
x
i
i
c
i
′
+
∑
i
=
1
n
∑
i
=
1
m
c
k
l
′
b
ij
i
)
y
j
c
′
b
j
+
∑
j
=
1
p
cpi
k
l
z
j
l
j
l
cp
i
l
j
)
Where:
x i is the EI of the ith profile in a set of m profiles x;
y j is the EI of the jth profile in a set of n profiles y;
z k l is the EI of the kth country and lth category/position pair in a set of p countries and q categories and positions;
a ij =a ji =1 if there is a link between profile i and profile j, otherwise a ij =a ji =0.
a j = ∑ i = 1 m a ij ,
i.e., the total number of profiles linked to profile j.
b y =b′ ji =1 if there is a link between profile i and source j, otherwise b y =b′ ji =0.
b j = ∑ i = 1 m b ij , b i ′ = ∑ j = 1 n b ji ′ ,
i.e., the total number of profiles linked to source j and the total number of sources linked to profile I, respectively.
c ik l =c′ k l l =1 if there is a link between profile i and country k plus category/position l, otherwise c ik l =c′ k l l =0.
c k l = ∑ i - 1 m c i l k , c i ′ = ∑ k = 1 p ∑ l = 1 q c l k l ,
i.e., the total number of profiles linked to country k and category/position l, and vice versa, respectively.
∑ i = 1 m b ji ′ b ik ,
i.e., the number of profiles which link to both source j and source k.
b ′ b k = ∑ j = 1 n ∑ l = 1 m b ji ′ b ik
is the total number of source co-links with source k for all sources.
∑ i = 1 m b ji ′ c i l k = ∑ c k i l ′ b ij
i.e., the total number of profiles which link to both source j and country k plus category/position l.
cpi k j l l =the inverse of the Transparency Int'l Corruption Perception Index for country k, if ranked; otherwise
Cpi k j l l =the average inverse Transparency International Corruption Perception Index for all countries.
cpi j l = ∑ k = 1 p cpi k l j l ,
i.e., a CPI normalization factor.
The above formulas can be recursively solved through the use of a computer, as will be known by those skilled in the art. In matrix notation, the linear system of equations becomes an eigensystem where the vector of EI scores corresponds to the principal eigenvector of the composite matrix:
x
y
z
=
1
3
A
B
C
B
′
B
′
B
B
′
C
C
′
C
′
B
CPI
x
y
z
As can be seen from the foregoing, the method of the invention determines a ranking of risk presented by members of a population based solely on the number of relationships between the persons themselves, and between the persons and exposure factors such as information source, geographic region, and political/career position. Errors introduced by prior art ranking methods in prematurely weighting the various exposure factors without consideration of their relationships to the population to be ranked are avoided.
It is to be appreciated that variations and modifications may be made to the invention without departing from the spirit and scope of the invention. | A method for ranking politically exposed persons and/or other persons and entities that pose a heightened risk based on their importance wherein an exposure index is determined for each person in the population as a function of the existence or absence of a relationship with each of the other members of the population and each of one or more exposure factors such as position held by the person, country in which the position is held, and source of information about the person. The politically exposed persons in the population are ranked in accordance with their respective exposure indexes. The population is sorted and a subset of the population containing those politically exposed persons having exposure indexes indicative or the highest likelihood of illicit financial activity is thereby identified. | 6 |
BACKGROUND
[0001] The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides an expandable well screen having a temporary sealing substance.
[0002] It is desirable to be able to circulate through a well screen while installing the screen in a well. In the past, such circulation has been provided by a washpipe extending through the screen. The washpipe permits fluid to be circulated through the screen before, during and after the screen is conveyed into the well, without-allowing debris, mud, etc. to clog the screen.
[0003] Expandable screens have been used in the past, either with or without the use of a washpipe. When the washpipe is used, a separate trip into the well is typically needed to expand the screen after the washpipe is removed from the screen. When the washpipe is not used, there is no sealed path available in the screen assembly to allow fluids to be pumped from the top of the screen to the bottom. As a result, any attempts to circulate fluid in the well would result in large volumes of fluid being pumped through the screen media, potentially plugging or clogging the screen.
[0004] Therefore, it may be seen that improved methods and systems are needed to permit circulation through an expandable well screen during its installation in a well, while not requiring an additional trip into the well to expand the screen. Other benefits could also be provided by improved methods and systems for installing well screens in a well.
SUMMARY
[0005] In carrying out the principles of the present invention, in accordance with an embodiment thereof, systems and methods are provided for installing well screens in a well. A temporary sealing substance is used to prevent fluid flow through a wall of an expandable screen during the installation process. Preferably, the screen is conveyed into the well and expanded in a single trip into the well.
[0006] In one aspect of the invention, a method of installing a well screen in a subterranean well is provided. The method includes the steps of: providing the screen including a temporary sealing substance preventing fluid flow through a wall of the screen; positioning the screen in a wellbore of the well; expanding the screen in the wellbore; and degrading the sealing substance, thereby permitting fluid flow through the screen wall.
[0007] In another aspect of the invention, a method of installing a well screen in a subterranean well includes the steps of: providing the screen including a temporary sealing substance preventing fluid flow through a wall of the screen; conveying the screen into a wellbore of the well while the sealing substance prevents fluid flow through the screen wall; expanding the screen in the wellbore; and degrading the sealing substance, thereby permitting fluid flow through the screen wall.
[0008] In yet another aspect of the invention, an expandable well screen system is provided. The system includes a well screen having a filtering layer for filtering well fluid as the fluid flows through a wall of the screen. A temporary sealing substance prevents the fluid from flowing through the screen wall. The screen has an expanded configuration and an unexpanded configuration in a well.
[0009] These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic cross-sectional view of a well screen installation system embodying principles of the present invention;
[0011] FIG. 2 is a schematic cross-sectional view of the system of FIG. 1 , wherein a well screen is being expanded in a well;
[0012] FIG. 3 is a schematic cross-sectional view of the system of FIG. 1 , wherein a screen installation process has been completed; and
[0013] FIG. 4 is an isometric view of a wall of the screen used in the system of FIG. 1 .
DETAILED DESCRIPTION
[0014] Representatively illustrated in FIG. 1 is a system 10 which embodies principles of the present invention. In the following description of the system 10 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
[0015] As depicted in FIG. 1 , a well screen assembly 12 is conveyed into a wellbore 14 . The assembly 12 includes an expandable hanger 16 , a fluid loss control device 18 , expandable screens 20 and a one-way valve 22 . The screens 20 are conveyed into an open hole portion of the wellbore 14 , while the hanger 16 is set in casing 24 above. However, it should be clearly understood that the principles of the invention are not limited to any particular details of the system 10 described herein. For example, any number of the screens 20 could be used, the screens could be positioned in a cased portion of the wellbore 14 , more, less or different tools, equipment, etc. could be included in the assembly 12 , etc.
[0016] The assembly 12 is preferably conveyed into the wellbore 14 with an expander tool 26 attached thereto. This permits the assembly 12 to be conveyed into, and expanded in, the wellbore 14 in a single trip into the well. The assembly 12 and expander tool 26 may be conveyed by means of a tubular string 28 , such as drill pipe or production tubing, or any other type of conveyance.
[0017] During installation of the assembly 12 , it is beneficial to be able to circulate through the assembly, including circulating through a passage 30 formed longitudinally through the screens 20 . For example, debris in the wellbore 14 may be displaced by circulating if problems are encountered in conveying the screens 20 into the uncased wellbore portion, specialized fluid pills may be spotted in the wellbore as needed (such as, to remediate a fluid loss problem), an appropriate completion fluid may be circulated into the wellbore prior to expansion of the screens, etc. The one-way valve 22 (such as a float shoe or float collar) prevents fluid circulated down through the passage 30 and into the wellbore 14 from flowing back into the interior of the screens 20 .
[0018] To provide this circulation capability, and also to prevent solids from clogging the screens 20 during installation, a sealing substance 32 (not visible in FIG. 1 ) is used to prevent fluid flow through sidewalls of the screens. The sealing substance 32 provides the function of a washpipe, without requiring an additional trip into the well to remove the washpipe and install the expander tool 26 .
[0019] As depicted in FIG. 1 , the liner hanger 16 has been set in the casing 24 . Referring additionally now to FIG. 2 , the expander tool 26 is being used to expand the screens 20 in the wellbore 14 . The same expander tool 26 may have previously been used to expand the hanger 16 (as depicted in FIG. 1 ), or another tool may be used if desired. An acceptable expander tool for use in the system 10 is available from Halliburton Energy Services, Inc. of Houston, Tex.
[0020] Referring additionally now to FIG. 3 , the screens 20 have all been expanded, and the expander tool 26 has been retrieved from the well, along with the tubular string 28 . Note that only a single trip into the well is required to convey the screen assembly 12 , position the assembly in the wellbore 14 , set the hanger 16 and expand the screens 20 . This is accomplished in the system 10 while also providing the ability to circulate through the assembly 12 during the installation.
[0021] The fluid loss control device 18 is closed as depicted in FIG. 3 , in order to prevent loss of well fluid after the tubular string 28 and expander tool 26 are retrieved. An acceptable fluid loss control device is the Quick Trip Valve available from Halliburton Energy Services, Inc. of Houston, Tex.
[0022] Referring additionally now to FIG. 4 , an enlarged view of a sidewall 34 of one of the screens 20 is representatively illustrated, apart from the remainder of the screen. The screen sidewall 34 includes a perforated tubular outer shroud 36 , an outer relatively coarse wire mesh drainage layer 38 , a relatively fine wire mesh filtering layer 40 , an inner relatively coarse wire mesh drainage layer 42 , and a tubular perforated inner base pipe 44 . The filtering layer 40 is sandwiched between the drainage layers 38 , 42 , and these are positioned between the outer shroud 36 and the base pipe 44 .
[0023] Preferably, at least the filtering layer 40 has the sealing substance 32 therein, for example, by impregnating the filtering layer with the sealing substance, so that the sealing substance fills voids in the filtering layer. However, any of the other layers 38 , 42 , shroud 36 or base pipe 44 could have the sealing substance 32 applied thereto, in keeping with the principles of the invention. For example, the sealing substance 32 could block fluid flow through the perforations in the shroud 36 or base pipe 44 , or the sealing substance could be impregnated in the wire mesh of the drainage layers 38 , 42 , or any combination of the above.
[0024] Preferably, the sealing substance 32 is degradable when exposed to a subterranean well environment. More preferably, the sealing substance 32 degrades when exposed to water at an elevated temperature in a well. Most preferably, the sealing substance 32 is provided as described in copending U.S. patent application Ser. No. 10/609,031, filed Jun. 27, 2003, the entire disclosure of which is incorporated herein by this reference.
[0025] The sealing substance 32 may be a degradable polymer, such as one or more of a polysaccharide, chitin, chitosan, protein, aliphatic polyester, poly( 1 actide), poly(glycolide), poly(ε-caprolactone), poly(hydroxybutyrate), poly(anhydride), aliphatic polycarbonate, poly(orthoester), poly(amino acid), poly(ethylene oxide), or a polyphosphazene. The sealing substance 32 may include a plasticizer, poly(lactic acid), a poly(lactide), or poly(phenyllactide).
[0026] The sealing substance 32 may degrade in the presence of a hydrated organic or inorganic compound solid, which may be included in the screens 20 , so that a source of water is available in the well when the screens are installed. For example, the hydrated organic or inorganic compound could be provided in the wire mesh of the drainage layers 38 , 42 . Alternatively, another water source, such as an aqueous solution, may be delivered to the sealing substance 32 after the screens 20 are conveyed into the well, such as by circulating the water source down to the screens.
[0027] Note that the sealing substance 32 may be degraded, thereby permitting fluid flow through the screen sidewall 34 , either before or after the screens 20 are expanded in the wellbore 14 . For example, formation water may be used as the water source to degrade the sealing substance after expansion of the screens 20 .
[0028] Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents. | An expandable well screen having a temporary sealing substance. In a described embodiment, a method of installing a well screen in a subterranean well includes the steps of: providing the screen including a temporary sealing substance preventing fluid flow through a wall of the screen; positioning the screen in a wellbore of the well; expanding the screen in the wellbore; and degrading the sealing substance, thereby permitting fluid flow through the screen wall. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a particle detector. More specifically, it relates to a device for simultaneously measuring alpha and/or beta particles with the same detector element.
Conventional detection devices for the measurement of alpha and beta particles employ, in addition to solids detectors, proportional counting tubes which generate pulses having heights proportional to the energy emitted by the particles. The separation between alpha and beta radiation is accomplished in these prior art devices by an energy analysis; that is, the separation process depends on the assumption that at a lower operating voltage only the alpha pulses exceed the counting threshold and at a higher operating voltage both alpha and beta pulses are measured. If two energy channels are provided, alpha and beta radiation can be detected simultaneously and separately. The same result can be realized by the use of a double counter if a separating foil is employed to assure that no alpha radiation enters the second counter.
The acuracy of these methods depends on the assumption that all alpha particles emit more energy than beta particles, or when a "mechanical" foil separation is employed, that the "reach" of all beta particles is greater than that of alpha particles. However, both requirements are met only in part and therefore lead to erroneous measurements.
For example, in large area counters, beta particles emit up to 200 keV of energy. Depending on the counting gas, alpha particles, which have already lost the majority of their energy due to absorption and self-absorption, emit the same amount of energy. Accordingly, under these conditions, alpha particles can not be distinguished from beta particles using the prior art energy analysis method. In practice, this means that a pure alpha radiator simulates an additional beta radiator and, depending on the operating voltage, a pure beta radiator may simulate an additional alpha radiator.
Depending on the operating voltage applied in a "mechanical" separation, the low-energy beta component, which is always present because of the continuous beta spectra, is lost or is recorded as alpha radiation. In difference measurements, alpha and beta particles cannot be distinguished if they both emit the same energy.
These basic errors become evident in measurements with proportional counting tubes and with solids and liquid detectors. The error occurs particularly with large counting tubes, when there is diffuse impingement of radiation and in certain counting gas mixtures such as CH 4
Since prior art detector devices, particularly those employing proportional counting tubes, cannot distinguish alpha particles from beta particles of the same energy if the alpha particles have lost energy before they entered the detector device, it is an object of the present invention to provide a device for detection of alpha and/or beta particles of any energy. That is, the invention is an improvement over prior art devices in which alpha particles which have lost energy within the radiation source cannot be detected or distinguished from beta particles.
SUMMARY OF THE INVENTION
In accordance with the present invention, a device is provided for simultaneously detecting alpha and beta particles which comprises a detector element, amplification means coupled to the output of the detector element and measuring means coupled to the output of the amplification means. The alpha and beta particles which impinge on the detector element exhibit different ionization densities, and this results in a voltage being generated at the output of the amplification means which has a rise time and amplitude corresponding to the type of particle impinging on the detector element. The measuring means measures at least the rise time of the voltage at the output of the amplification means, the rise time being different for the alpha and beta particles and providing a means for distinguishing between the two types of particles.
The present invention utilizes the ionization density rather than the emitted energy for separation of alpha from beta rays, the ionization density being different for alpha and beta radiation. The ionization density manifests itself in the pulse shape at the output of the amplification means making it possible to effectively separate alpha and beta radiations.
The advantage of such a separation is that the measurements are correct, and that with simultaneous measurement of alpha and beta particles, shorter measuring times or a higher statistical accuracy can be realized. Further, with the use of control radiators during the measurements of alpha and beta radiation, the reliability of the measurements can be increased. Also, this type of alpha/beta discrimination provides a higher time resolution capability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the invention showing a large area counter.
FIG. 2 is a detailed schematic diagram of an embodiment of the invention;
FIG. 3 is a voltage-time curve showing the output of the apparatus depicted in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a top schematic view of a large area proportional counting tube 1 having a counting gas inlet 2 and an outlet 3. A typical gas which can be used in the counter tube is CH 4 with a pressure of approximately 30 mb above atmospheric pressure.
An insulating frame 4 consisting of individual, mutually parallel tensioned wires 5 made of molybdenum with a diameter of 0.03 mm. are disposed within the tube 1, one end of each of the wires 5 being connected through a resistor 6 to one terminal of a common resistor 7. In a typical application, each of the resistors 6 has a value of 10,000 ohms and resistor 7 has a value of 1000 ohms. The other terminal of resistor 7 is connected to a terminal 8 for coupling to a high voltage source V H having a magnitude on the order of 6000 volts.
An amplifier 9 has an input coupled through a capacitor 10 to the junction of resistor 7 and resistors 6, capacitor 10 having a capacitance of 100 pF and a voltage rating of 6000 volts. Power for operation of amplifier 9 is provided by a current supply connected to a terminal 11. An output voltage pulse is obtained at output terminal 12 when particles impinge on the wires 5 of counter tube 1.
The resistor 7 and amplifier 9 may be integrated with the detector element or directly attached thereto in order to minimize the effect of capacitances which could influence the rise time of the output pulse at terminal 12. The capacitances of the individual wires 5 with respect to the mass potential must be kept as low as possible (preferably substantially below 20 pF) so as not to flatten the rise times of the alpha particle pulses. A plurality of counting wires can be combined as long as this condition is met.
A detailed schematic diagram of another embodiment of the invention is shown in FIG. 2. In this embodiment, a counting wire 5 is coupled through the 10,000 ohm resistor 6, the 100 pF signal coupling capacitor 10 and a 1000 ohm resistor 22 to the positive input of an operational amplifier 23. In a typical embodiment of the invention, the capacitance C z between the wire 5 of the counting tube 1 and ground is about 7 pF.
A capacitor bank 24 consisting of parallel capacitors 25 is charged (with a time constant of >1 ms for the rise of the high voltage V H at junction 28) through a resistor 27 having a value in excess of 100,000 ohms to approximately 6000 volts with respect to ground by a positive voltage source connected to a terminal 26. The junction 28 between the ungrounded end of capacitor bank 24 and resistor 27 is connected through a 470 ohm resistor 29 to the junction of resistor 6 and capacitor 10. The voltage at the junction 28 has a delayed rise time in order to protect the amplifier 23, the amplifier 23 being typically a type LH 0032 CG manufactured by "National Semiconductors." Resistors 6 and 29 form a potentiometer.
This amplifier has the ability to process pulses having a rise time of less than 50 ns.
Current is supplied to the positive input of amplifier 23 through a Schottky diode 30 by a positive 12 volt source connected to a terminal 31, the diode 30 being poled to conduct current from the amplifier input toward terminal 31. Similarly, current is supplied to the positive input of amplifier 23 through a Schottky diode 32 by a negative 12 volt source connected to a terminal 33, the diode 32 being poled to conduct current from terminal 33 toward the positive input terminal of the amplifier. Resistance 22 and diodes 30,32 form a clamping circuit to protect the amplifier 23. A 10,000 ohm resistor 34 is connected between the positive input terminal of amplifier 23 and ground.
The output of amplifier 23 is coupled to an output terminal 35, to ground through a 1000 ohm resistor 36 and to the negative input terminal of the amplifier through a 10,000 ohm resistor 37. A 1000 ohm resistor 38 connects the negative input terminal of amplifier 23 to ground. Resistors 37,38 adjust the amplification of the amplifier 23. Frequency compensation is obtained by a 5 pF fixed capacitor 39 connected to amplifier 23 in parallel with a variable capacitor 40 having an adjustable range between 1 and 5 pF Capacitances 41 and 42 are coupled between terminals 31 and 33 respectively and ground to protect the amplifier 23 from the 12 volt sources, terminal 31 and 33 being connected to amplifier 23 via leads 43 and 44 respectively in order to couple the respective +12 volt and -12 volt sources to the amplifier.
The operation of the circuit is as follows. Due to their different ion densities, the α- and β-particles generate pulses with different pulse rise times in the detector 1 shown in FIGS. 1 and 2. The relatively short rise times of the pulses can only be resolved by a special detector arrangement with appropriate electronic properties, with the time constant of detector 1 during the ionization process being of prime importance. This constant has to be equal to or less than the shortest rise time to be resolved of the pulses generated. This time constant T D of the detector 1 is determined primarily by two factors: (1) the internal resistance R iD during the ionization process, and (2) the detector capacity C D between counting wire 5 and the casing of detector 1. These two characteristic values, it can be stated in a simplified way, determine the internal time constant T D the deteator 1 by the relationship
T.sub.D ≈R.sub.iD.C.sub.D
This relation shows that short pulse rise times can only be obtained with a relatively low detector capacity C D .
FIG. 2 shows the measuring arrangement in which the detector 1 with only one counting wire 5 is used (C D =7 pF). The different rise times of α- and β-pulses can be observed on the output 35 of the measuring arrangement with the aid of an oscilloscope (Tektronix Typ 547). FIG. 1 presents the design of a large-area detector with a counting grid of 26 wires. Each wire 5 has a capacity of about 2 pF against the detector casing. All detector elements 5, 6 are connected to a common coupling load resistance 7 (220Ω) via 26 collecting load resistances 6 (10 kΩ). Sufficient electronic decoupling of the individual detector elements 5, 6 is assured by a resistance ratio of the resistances 6, 7 of 45:1. In this type of detector, a high voltage V H of 3800 V is required in the socket 8.
The pre-amplifier 9 is designed so that even pulse rise times of 10 ns can be transmitted at a maximum amplitude of about 10 V s . During injection of α- and β-particles in the detector 1, the curves 52 (FIG. 3) can be observed at the output 12 of the amplifier 9 with the aid of the oscilloscope.
Typical voltages at the output terminal 35 of amplifier 23 are shown graphically in FIG. 3 which is a plot of voltage in volts against time in nanoseconds, each division on the time axis being equal to 100 ns and each division of the voltage axis being equal to one volt. The crosshatched area bounded by envelope 50 sharply defines the voltage-time region produced by beta particles. The voltage amplitudes generated by the beta particles is in the range 1 to 300 mV and the rise time of the envelope 50 from zero to its maximum value is approximately 100 ns.
The areas bounded by curves 52, on the other hand, show the amplitude spectrum of various alpha particles having different energy losses before entering the detector device 1. The rise times of the envelopes 52 generated by the alpha particles from zero to a maximum voltage value are on the order of 50 ns, and it is this difference in rise time which permits the apparatus to distinguish between alpha and beta particles.
The reliability of the measurements can be further increased by the use of control radiators. Referring to FIG. 2.
By means of a control radiation source 55 with a movable disk 56 of a diaphragm 57, the optimum separation of the α- and β-measuring channels can be controlled during measurement of α- or β-particles. For example, a β-control-radiation-source can be measured at the same time as the α-radiation. With correct adjustment of the α-β-discrimination, no β-impulse should enter the α-measuring channel.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A device for simultaneously detecting alpha and beta particles which comprises a detector element, amplification means coupled to the output of the detector element and measuring means coupled to the output of the amplification means. The alpha and beta particles which impinge on the detector element exhibit different ionization densities, and this results in a voltage being generated at the output of the amplification means which has a rise time and amplitude corresponding to the type of particle impinging on the detector element. The measuring means measures at least the rise time of the voltage at the output of the amplification means, the rise time being different for the alpha and beta particles and providing a means for distinguishing between the two types of particles. | 1 |
BACKGROUND AND SUMMARY
Co-owned Pat. Nos. 4,581,026, 4,626,250, and 4,932,948 disclose male external catheters intended for use with urinary drainage systems. Each such catheter is in the form of a sheath having a cylindrical body section, an intermediate neck section, and a reduced drainage tube section, with the entire catheter being formed of a soft elastic material such as latex or silicone rubber. In addition, the catheters disclosed in each of these patents have tubular elongated inner sleeves of soft elastic material designed to fit over the glans of a wearer's penis. Such a sleeve is intended to make sealing contact with the glans and is maintained in stretched condition over the glans by adhesive means adhering the cylindrical section to the penile shaft.
As shown in these patents, the tubular sleeves are relatively long, so as to cover as much of the glans as possible, and terminate in small distal openings so that urine may be discharged into the intermediate neck portions of the sheaths. For sealing effectiveness, it has been considered important to insure that the thin elastic sleeves are stretched over the glans and are maintained in such stretched condition when the catheters are worn. That requires the caregiver or the patient (if a catheter is self-applied) to hold the penis in position as the sleeve is stretched over the glans. While devices have been developed to make the task easier (see, for example, the applicator of co-owned Pat. No. 4,589,874), it is still necessary for the user to use both hands in the application of such a catheter, one for unrolling the sheath over the penis and the other for holding the penis, with the sleeve in stretched condition over the glans, at least at the commencement of that operation.
While an adhesively-attached catheter with an inner sleeve operates effectively if it is applied carefully with the sleeve stretched over the glans, instances have occurred where nurses (or other caregivers) have failed to perform such procedures completely, or with sufficient patience and care, because they are concerned about possible discomfort or injury to the patient, or are rushing to perform other healthcare duties, or simply because they find themselves uncomfortable making such direct and extended contact with the limp penis of an incontinent patient. If such an external catheter is improperly or incompletely applied, it may cause considerable patient discomfort and produce other serious consequences such as rendering the device ineffective or inoperative and causing leakage of urine when the drainage system is in use.
Other problems may also arise. If the stretched inner sleeve is to cover the glans, it is important that it be relatively long and that its distal opening be small. However, such a device obviously will fail to operate properly if the small distal opening of the stretched sleeve is not in register with the urethral opening of the patient, so care must be taken to assure that proper alignment exists. Also, in fitting such a sheath upon a patient, it is important that the sleeve be stretched, but not stretched excessively, because excessive stretching might cause the distal end of the sleeve to be positioned near the backside of the glans, or even behind the glans, applying a clearly undesirable constrictive force on the patient.
Recent developments in catheter-applying techniques involve the use of catheters that are similar to those described above but may or may not supplied or applied in rolled form and may or may not have inner sleeves. Reference may be had to co-owned Pat. Nos. 5,423,784, 5,336,211, 4,586,974, 4,540,409, and Des. No. 358,882. In each, a catheter is supported by an open-ended applicator tube with the neck and drainage tube portions of the catheter located within the tube and the cylindrical portion of the catheter reverted or turned backwardly over the outside of the tube. Such a system generally allows the user to apply a catheter to a patient without gripping the penis between the fingers, but some gripping may still be necessary if the catheter has an inner sleeve that should be stretched over the glans during application. In such a case, the ease of application may be decreased rather than increased because operation of the applicator tube in releasing and applying a catheter is itself a two-handed operation, making it difficult for the user to also hold the penis and stretch the sleeve over the glans.
An important aspect of this invention therefore lies in the discovery that the advantages of sleeve-equipped catheter may be realized without encountering the difficulties indicated above if such a sleeve is shortened, its opening is greatly enlarged, and it is positioned so that it may make sealing contact with the penile shaft rather than the glans. Unlike the inner sleeves of the catheters disclosed in the aforementioned patents, the sleeve of the present catheter must be relatively short, taking the form of a narrow annular flap, and its opening must be relatively large. Specifically, the opening must be large enough so that the annular flap slides easily over the glans (or the foreskin covering the glans in an uncircumcised patient) and will sealingly engage the penile shaft or the proximal portion of the glans (or foreskin) immediately adjacent the shaft. The flap should be dimensioned so that its opening has a diameter in the general range of 75 to 92% of the inside diameter of the cylindrical portion of the sheath, with the preferred range being 78 to 89% and the optimum range being about 81 to 87%. The length of the flap depends partly on the size of the catheter but, in general, the flap should have a length within the range of about 0.25 to 0.65 inches and should not in any case exceed 35% of the length of the sheath's intermediate section. A flap length of 0.5 inches has been found particularly effective for adult-size catheters, whereas 0.3 inches has been found suitable for a pediatric-size catheter.
Other features, objects and advantages will become apparent from the specification and drawings.
DRAWINGS
FIG. 1 is a vertical longitudinal sectional view of a catheter embodying the invention in combination with an applicator tube.
FIG. 2 is a sectional view of the catheter in extended condition.
FIG. 3 is a sectional view of a catheter embodying the invention in rolled condition.
FIGS. 4-6 are longitudinal sectional views illustrating steps in the application of the catheter to a patient.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 2 of the drawings, the numeral 10 generally designates a catheter in the form of a thin, unitary sheath of soft elastic material such as, for example, latex or silicone rubber. The sheath includes a generally cylindrical body portion 11, an intermediate portion 12, and a drainage tube portion 13. At its forward or distal end, the intermediate portion 12 is provided with a rounded taper 14 that merges with the drainage tube portion 13. Convolutions or annular enlargements 15 may be provided in the drainage tube portion at its proximal end, the purpose of such convolutions being to permit greater stretchability, bending, and twisting of the drainage tube portion when the device is in use, and to do so with less chance that kinking or obstruction of the lumen might occur. The catheter is conventionally produced by dipping and curing steps in which a mandrel of selected configuration is alternately lowered into and removed from a liquid bath of latex (or other suitable elastomer), with the wall thickness of the intermediate portion 12 and the drainage tube portion 13 being substantially thicker than the wall of cylindrical portion 11.
The sheath also includes an annular flap 16 located within the interior of the sheath. The flap has an outer end (determined radially) 16a that merges with the inner surface of the sheath at a point (or line) between cylindrical portion 11 and intermediate portion 12. The opposite inner end 16b of the flap defines an opening 17 slightly smaller than the interior of the cylindrical portion and intermediate portion of the sheath. In FIG. 2, the flap is shown as sloping forwardly or distally but, if desired, the flap may slope in a proximal direction or even extend radially inwardly in a plane normal to the axis of the sheath. Even when the sheath has its flap normally sloping distally, as shown in FIG. 2, that flap may tend to reverse its direction when the sheath is tensioned slightly and mounted upon an applicator tube (FIG. 1).
Like the cylindrical portion 11, the flap 16 should be extremely thin and elastically stretchable. A thickness of about 0.008 inches has been found effective for both the flap and the cylindrical wall, but greater or lesser thicknesses may be provided, if desired.
There is a critical size relationship between the opening of flap 16 and the inside diameter of the cylindrical portion 11 if effective sealing and safe operation of the catheter are to be achieved. The diameter "d" of opening 17 should generally fall within the range of 75 to 92% of the inside diameter "D" of the cylindrical body portion 11 when the sheath is in unstretched or untensioned condition. The preferred percentage ratio is 78 to 89%, with the optimum falling within the range of about 81 to 87%. The length "l" of the flap--that is, the distance between ends 16a and 16b--should be no greater than 35% of the length "L" of the intermediate portion 12 and, in general, should be within the range of about 0.25 to 0.65 inches. For adult-size catheters, the optimum is believed to be about 0.50 inches, whereas for pediatric catheters a dimension of about 0.30 inches is preferred.
The d/D ratio is critical because the flap 16 of catheter 10 must be capable of sliding over the glans of the penis (or the foreskin-covered glans for an uncircumcised male) with only limited stretching and, therefore, limited resistance. For any given patient the proper size of a catheter as a whole is primarily determined by dimension D. Ideally, the cylindrical body portion 11 of the catheter should have approximately the same diameter (inside), or a slightly smaller diameter, as that of the patient's penis in a flaccid state so that when the sheath is fitted upon the patient, adhesive layer 18 will contact the penile shaft without gaps, wrinkles, or channels that might cause leakage. Therefore, while catheters of the type depicted in FIG. 2 would be available in several different sizes, once such a catheter of proper size is selected for a given patient, based on dimension D, the flap opening 17 will also be of the proper size if the catheter embodies d/D ratios given above.
The adhesive layer 18 along the inner surface of cylindrical body portion 11 may be of any suitable medical-grade pressure sensitive adhesive. A conventional medical-grade acrylic adhesive has been found effective, but other known adhesives may be used.
FIG. 1 depicts catheter 10 supported upon an applicator tube 20. The tube is open-ended and the intermediate portion of the catheter is located within the interior of the tube with the reduced drainage tube portion 13 projecting from one end 20a. The cylindrical portion 11 of the catheter extends out of the opening at the opposite end 20b of the tube and is folded backwardly over the outside of the tube. To reduce friction between the catheter and the surfaces along the outside and end 20b of the tube 20, a mesh sleeve 21 of nylon, polyethylene, polypropylene, or some other suitable polymeric material is interposed between the two. The adhesive layer 18, on what will become the inner surface of the catheter when the cylindrical section is reverted, is covered by a removable strip of silicone-coated paper tape 22 or other suitable release covering.
Since tube 20 has a larger inside diameter than the unstretched outside diameter of the sheath, the sheath is stretched slightly about the opening at end 20b and the cylindrical body section 11 is in a moderately tensioned state about the outer surface of the tube. Such stretching may cause the annular flap 16 to protrude outwardly away from the open end 20b of the tube as illustrated in FIG. 1. In any case, flap 16 can be easily viewed by the user at the time of application. Such application is commenced by first removing the protective release tape 22 and then urging the open end 20b of the applicator tube over the patient's penis P as depicted in FIG. 4. Flap 16 engages the glans (or the foreskin over the glans) and flexes inwardly. Continued advancement of the tube 20 brings the flap 16 to a position about the penile shaft directly behind the glans (FIG. 5). Thereafter, the user grips the exposed portion of the applicator tube near end 20a and pulls the drainage tube portion 13 of the catheter in a distal direction (away from the patient) while simultaneously urging the applicator tube 20 in a proximal direction (towards the patient) to cause the cylindrical body portion 11 to slide off of the applicator tube and onto the penile shaft. The applicator tube 20 and mesh sleeve 21 are then withdrawn, leaving the catheter in place upon the patient as illustrated in FIG. 6.
Effective sealing between annular flap 16 and the penile shaft occurs even though the flap is not highly stretched because the surface of the shaft is generally smooth and of even contour and because backflow, if it should occur, will tend to urge the flap into tighter sealing engagement with the penile shaft. It is to be understood, however, that the short annular flap 16 may be operative, although generally to a lesser extent, if it also engages the rear (proximal) portion of the glans--that is, if the catheter were applied with penile insertion into intermediate portion 12 no further than as shown in FIG. 4.
While the use of an applicator tube 20 is preferred, catheter 10 might instead be rolled in a conventional manner as illustrated in FIG. 3. In such a case, some means are necessary to prevent adhesive 18 from adhering to the outer surface (or what will become the outer surface) of the catheter. Such release means might take the form of a release tape or interliner (which in this case should be highly flexible) or of a release coating or release layer (e.g., of silicone rubber) applied to the outer surface of the catheter during manufacture. In all other respects, the catheter illustrated in FIG. 3 is identical to the catheter of FIG. 2.
While in the foregoing, we have disclosed embodiments of the invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of the invention. | An external catheter for a male urinary incontinence collection system is disclosed, the catheter taking the form of a tubular sheath of soft elastic material having a thin-walled cylindrical section, a reduced drainage tube section, and an intermediate section merging with both the drainage tube and cylindrical sections. The sheath also includes a thin elastic annular flap extending inwardly from the sheath's inner surface where the intermediate and cylindrical sections merge. The flap has an inner end defining a generally circular opening of a critical size in relation to the inside diameter of cylindrical section and the length of the intermediate section. | 0 |
FIELD OF THE INVENTION
[0001] The disclosed invention relates to the manufacture of gears and other toothed articles. In particular, the invention is directed to the chamfering and/or deburring of gears, especially bevel gears.
BACKGROUND OF THE INVENTION
[0002] In the cutting of gears and other toothed articles, such as bevel gears and in particular spiral bevel and hypoid gears, it is common to produce a burr at the end of a tooth where the cutting tool exits the tooth slot. Burrs are particularly noted at the end of concave tooth flanks on spiral bevel ring gears and pinions. Regardless of location on a gear, burrs pose a safety and performance hazard and therefore must be removed.
[0003] It may also be desirable to provide a chamfer at one or both ends of gear teeth including tip and root ends. After cutting, sharp corners usually exist at the intersection of the tooth sides, tip and/or root with the front and/or back faces and removing the sharp corners makes handling the gear safer and eliminates a potential area of unacceptably high hardness after heat treating.
[0004] Chamfering may be carried out at various times and locations with respect to the actual cutting process. Separate chamfering machines are known in the art. Chamfering and/or deburring of a gear with a rotary tool while the gear remains positioned on the work spindle of a cutting machine is known, for example, from U.S. Pat. No. 7,431,544 or U.S. Patent Application Publication No. 2007/0020058. However, chamfering in this manner slows production of the particular machine since cutting of a subsequent workpiece must wait until after the gear is chamfered and/or deburred.
[0005] From U.S. Pat. No. 3,083,616 it is disclosed to provide a chamfering mechanism adjacent a workpiece spindle in a gear cutting machine whereby chamfering takes place simultaneously with gear cutting. A rod-shaped deburring tool advances from a retracted position to chamfer the edge of a newly-cut tooth as the gear is indexed to the next tooth slot position for cutting. While such an arrangement may reduce non-cutting time on the machine, there is little flexibility with such a system with respect to modifying the size, extent or shape of the chamfer. Furthermore, the disclosed chamfering mechanism is not capable of chamfering gears produced by continuous indexing processes (i.e. face hobbing).
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a gear processing machine, such as a gear cutting or grinding machine, wherein a chamfering and/or deburring apparatus and auxiliary spindle are included on the same machine. A transfer mechanism loads, unloads and transfers workpieces between a machining spindle and the auxiliary spindle thereby enabling simultaneous cutting and chamfering and/or deburring processes to be carried out. Via the auxiliary spindle, completed workpieces may be removed from the machine and blank workpieces may be loaded into the machine while another gear is being processed on the machine spindle thereby enhancing machine output and creating a more efficient operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a partial front view of a gear processing machine showing a work spindle and the inventive chamfering and/or deburring apparatus with auxiliary spindle.
[0008] FIG. 2 is a side view of the inventive chamfering and/or deburring apparatus and auxiliary spindle.
[0009] FIG. 3 is a front view of the inventive chamfering and/or deburring apparatus and auxiliary spindle.
[0010] FIG. 4 is a partial front view of a gear processing machine showing a work spindle, the inventive chamfering and/or deburring apparatus with auxiliary spindle and a transfer arm in a working position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Before any features and at least one construction of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other constructions and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purposes of description and should not be regarded as limiting.
[0012] The use of “including”, “having” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Although references may be made below to directions such as upper, lower, upward, downward, rearward, bottom, top, front, rear, etc., in describing the drawings, there references are made relative to the drawings (as normally viewed) for convenience. These directions are not intended to be taken literally or limit the present invention in any form. In addition, terms such as “first”, “second”, “third”, etc., are used to herein for purposes of description and are not intended to indicate or imply an order of importance or significance.
[0013] In the context of the present invention, the term “bevel” gears is understood to be of sufficient scope to include those types of gears known as bevel gears, “hypoid” gears, spiral bevel and hypoid gears, as well as those gears known as “crown” or “face” gears.
[0014] The inventive chamfering and deburring apparatus 2 is shown in FIG. 1 . The apparatus 2 is preferably included as an element of a gear processing machine 4 , preferably a gear cutting or grinding machine of the type as disclosed in U.S. Pat. Nos. 6,669,415 and 6,712,566, the disclosures of which are hereby incorporated by reference. For the sake of clarity and ease of viewing, outside sheet metal and some guarding has been omitted. The chamfering and deburring apparatus 2 is preferably positioned near to a workpiece spindle 6 of the gear cutting or grinding machine 4 (discussed hereafter with reference to a gear cutting machine). A pivoting transfer arm 8 transfers workpieces between the workpiece spindle 6 and an auxiliary spindle 10 which forms a part of the chamfering and deburring apparatus 2 although auxiliary spindle 10 may also have utilities apart from chamfering and deburring as will be discussed further below. A three-jaw chuck 12 for holding a workpiece is shown on spindle 10 but other suitable workholding equipment may be utilized as can be appreciated by the skilled artisan. Workpiece spindle 6 is shown without workholding equipment. However, the skilled artisan will understand that appropriate workholding equipment will be utilized depending upon the geometry of the workpiece being machined.
[0015] FIG. 2 illustrates a preferred arrangement for the chamfering and deburring apparatus 2 and the auxiliary spindle 10 . The apparatus 2 comprises a tool head 3 , tool spindle 5 and tool 14 , such as a chamfering and deburring tool, which is rotatable about a tool axis T. Tool 14 is driven for rotation by a servo motor 16 . Tool head 3 is pivotable about a pivot axis P driven by servo motor 18 . Tool head 3 is movable in a first linear direction, Y, along rails 20 mounted to a column 22 with the linear motion being driven by servo motor 24 . Column 22 , and hence tool head 3 , is movable in a second linear direction, Z, via a servo motor 25 ( FIG. 3 ). Column 22 is movable on rails 26 mounted to frame 28 . Frame 28 is movable in a third linear direction, X, on rails 30 via hydraulic piston 32 although other types of movers, such as a servo motor, may be utilized. Preferably, hydraulic piston 32 moves frame 28 between an advanced position toward the tool head 3 (shown) and a retracted position away from the tool head 3 although additional defined stops or coordinated movement with other machine motions are also contemplated. A servo motor may be used for moving frame 28 instead of hydraulic piston 32 .
[0016] Auxiliary spindle 10 is driven for rotation about axis A by a servo motor 34 . Auxiliary spindle 10 is also linearly movable in direction X on rails 36 via servo motor 38 . Alternatively, auxiliary spindle 10 may be direct driven. Preferably, directions X, Y and Z are mutually perpendicular with respect to one another although one or more may be inclined with respect to its perpendicular orientation. For purposes of illustration, in all Figures, the Y direction is vertical.
[0017] Movement of the tool head 3 in direction Y, column 22 in direction Z, auxiliary spindle in direction X, pivoting of tool head 3 about axis P, as well as tool 14 rotation about axis T and auxiliary spindle 10 rotation about axis A, is imparted by the separate drive motors 24 , 25 , 38 , 18 , 16 and 34 respectively. The above-named components are capable of independent movement with respect to one another or may move simultaneously with one another. Each of the respective motors is preferably associated a feedback device such as a linear or rotary encoder, such as pivot axis encoder 40 or Y direction encoder 42 ( FIG. 2 ), as part of a computer numerically controlled (CNC) system which governs the operation of the drive motors in accordance with instructions input to a computer controller (i.e. CNC) such as a Fanuc model 30i (not shown).
[0018] With respect to loading a workpiece from outside of the machine 4 into auxiliary spindle 10 , such as a blank workpiece to be cut, or with respect to unloading a workpiece from machine 4 by removing a machined workpiece from auxiliary spindle 10 , such as a deburred and/or chamfered workpiece, the loading and unloading may be carried out manually or via an automated mechanism (e.g. gantry or robotic loading/unloading mechanism).
[0019] An operation for chamfering and/or deburring will be described from an exemplary beginning reference point of a blank workpiece (e.g. pinion with shank) being positioned on spindle 6 and a cut workpiece of the same type (e.g. pinion with shank) being positioned on auxiliary spindle 10 . Cutting commences on the blank workpiece on spindle 6 and chamfering commences on the workpiece on auxiliary spindle 10 . The chamfering and deburring tool 14 is moved along a path relative to the workpiece by a combination of one or more motions in the previously described linear and/or rotary directions X, Y, Z, P, T and A whereby the desired chamfered surface is produced on the teeth of the workpiece at the ends of the teeth (e.g. on one or both sides, top and/or root) at the front face and/or back face of the gear. Additionally, chamfering along all or part of the lengthwise direction of the tooth tip may also be carried out.
[0020] Once chamfering is completed, the workpiece is unloaded from auxiliary spindle 10 and removed from the machine 4 in a manner as discussed above. Another workpiece blank is then loaded into auxiliary spindle 10 . Since the gear chamfering process is usually of a shorter duration than cutting a gear blank, there is sufficient time remaining after chamfering to unload the completed gear and subsequently load a gear blank into auxiliary spindle 10 during which cutting of the gear blank is still being carried out on spindle 6 . For example, a cutting time of 1 minute and 50 seconds is needed for a spiral bevel pinion having 11 teeth while only about 1 minute is needed for chamfering. Therefore, it can be seen that about 50 seconds remains in which one or more additional procedures may be carried out and/or the completed gear can be unloaded from auxiliary spindle 10 and a gear blank can then be loaded on to the auxiliary spindle.
[0021] Thus, upon the completion of cutting, the transfer arm 8 is actuated outwardly (i.e. away from the spindles 6 , 10 ) from its rest position ( FIG. 4 ) and rotated to simultaneously grip a cut gear 44 on spindle 6 and a gear blank 46 on auxiliary spindle 10 via grippers 48 (two or more at each end of transfer arm 8 ), withdraw both workpieces from their respective spindles and then rotate (about 180 degrees in the preferred embodiment) to bring the blank gear 46 to the work spindle 6 for cutting and the cut gear 44 to auxiliary spindle 10 for chamfering. Inward movement of the transfer arm 8 (i.e. toward the respective spindles) is then effected in order to load the gear blank 46 and cut gear 44 in their respective spindles. Once the workpieces are loaded, the transfer arm 8 returns to its rest position as shown in FIG. 1 .
[0022] A partition or divider (not shown), such as an accordion-style door, may be included between the spindle 6 and the auxiliary spindle 10 for preventing the influx of metal chips, grinding swarf, processing fluids, etc. into the area around auxiliary spindle 10 during those times when machining operations are being performed on spindle 6 . The operation of the partition or divider may be coordinated with the operation of transfer arm 8 such that when transfer arm 8 is in its retracted position ( FIG. 1 ), the partition or divider is extended to form separate chambers, one chamber containing spindle 6 and the other chamber containing auxiliary spindle 10 . Upon axial movement of transfer arm 8 out of its retracted position to an operating position, the partition or divider is retracted thereby allowing the transfer of workpieces between spindle 6 and auxiliary spindle 10 .
[0023] Transfer arm 8 is preferably driven by two servo motors. First servo motor 50 controls the linear outward and inward movements as well as the extent of the linear movement which is dependent upon, among other things, the geometry of the workpiece since it can be understood that greater linear travel is necessary to provide adequate clearance for longer workpieces, such as bevel pinions with shafts, than for gears without shafts such as, for example, most designs of bevel ring gears. The other servo motor (not shown) controls the rotation of transfer arm 8 in order to exchange the workpieces between spindles 6 , 10 and bring them into the proper alignment with respect to the spindles 6 , 10 . While servo drives are preferred, the movements of transfer arm 8 may be effected by other linear and rotational driving means such as hydraulic or pneumatic means.
[0024] In loading cut bevel pinions with shafts into auxiliary spindle 10 for chamfering, it may be desirable to axially retract auxiliary spindle 10 be a predetermined amount prior to or during loading in order to create an amount of clearance (i.e. a gap) between the back face of the pinion and the front of chuck 12 to allow the chamfering tool 14 access to the back face of the pinion for chamfering the ends of the teeth at their intersection with the back face of the pinion. By retracting auxiliary spindle 10 a predetermined controlled amount (via servo motor 32 ), the shank of a cut pinion will not be fully inserted into chuck 12 and a gap of a predetermined dimension will be created for chamfering. Upon removal of the chamfered gear from chuck 12 , a pinion blank is then loaded and the shaft of the pinion may be completely inserted into chuck 12 which may then be axially advanced to a position parallel with the pinion being cut on spindle 6 whereby they both may be gripped simultaneously by the transfer arm 8 subsequent to the completion of cutting.
[0025] As previously mentioned, in addition to chamfering and/or deburring, or as an alternative thereto, other processes may be carried out on a workpiece positioned in auxiliary spindle 10 . For example, if machine 4 is a gear grinding machine and grinding of previously cut gears is being carried out on spindle 6 , auxiliary spindle 10 may be utilized as a spin station for removing grinding fluids from a workpiece. Also, measuring of gears may also be performed while a workpiece is positioned on auxiliary spindle 10 . Any noted deviations from a desired tooth surface geometry may be utilized for making process corrections in the cutting or grinding process being performed on machine 4 in an effort to reduce or eliminate such deviations on successive workpieces. Additionally, a fixed deburring tool may be attached to and extend from tool head 3 or tool spindle 5 .
[0026] Alternatively, auxiliary spindle 10 may be utilized for stock division of cut gears prior to grinding. Stock dividing is the proper positioning of a partially finished (e.g. cut) gear relative to a tool (e.g. grinding wheel) prior to the initiation of a finishing cycle (e.g. grinding). Once the proper positioning for grinding of cut workpiece is known with respect to a probe or other device relative to auxiliary spindle 10 , that same relative positioning can be repeated for the workpiece positioned on work spindle 6 with respect to a grinding wheel.
[0027] While the invention has been described with reference to preferred embodiments it is to be understood that the invention is not limited to the particulars thereof. The present invention is intended to include modifications which would be apparent to those skilled in the art to which the subject matter pertains without deviating from the spirit and scope of the appended claims. | Gear processing machine ( 4 ), such as a gear cutting or grinding machine, wherein a chamfering and/or deburring apparatus ( 2 ) and auxiliary spindle ( 10 ) are included on the same machine. A transfer mechanism ( 8 ) loads, unloads and transfers workpieces between a machining spindle ( 6 ) and the auxiliary spindle ( 10 ) thereby enabling simultaneous cutting and chamfering and/or deburring processes to be carried out. Via the auxiliary spindle, completed workpieces may be removed from the machine and blank workpieces may be loaded into the machine while another gear is being processed on the machine spindle thereby enhancing machine output and creating a more efficient operation. | 8 |
BACKGROUND OF THE INVENTION
In a wide variety of applications there exists the need for a product which will thicken or gel organic based formulations. To meet this need, several gelling agents for organic solvents are available on the market. These generally include colloidal particles (such as silica), metallic soaps (aluminum soap), and cellulose derivatives that require polar cosolvents.
In co-pending application Ser. No. 222,660, entitled ESTERS OF POLYMERIC HYDROXYPROPYL CARBOHYDRATES AND METHOD OF USING SAME AS GELLING AGENT FOR ORGANIC SOLVENTS, filed on Feb. 1, 1972 and assigned to the assignee of the present invention, now U.S. Pat. No. 3,824,085, issued July 16, 1974, there is described and claimed a gelling agent and process for making same. The process of said co-pending application involves the use of hydroxypropyl cellulose and starch esters, specifically the acetate and laurate esters. The process is quite satisfactory and the hydroxypropyl carbohydrate esters are capable of gelling a large number of organic solvents.
In accordance with the present invention a new composition and process has been discovered which comprises the hydroxypropylation, methylation and acetylation of cellulose in one continuous process to produce methyl hydroxypropyl cellulose acetate, a water insoluble gelling agent for organic solvents. More specifically, the process of this invention involves the simultaneous hydroxypropylation and methylation of cellulose with the continued derivatization of cellulose into acetate. The commencement of the acetylation process prior to the cessation of the hydroxypropylation process eliminates the isolation and recovery of the methyl hydroxypropyl cellulose. As a result, the product is formed in one continuous process.
The preparation of this new polymeric carbohydrate derivative is economical, based on both material and processing costs. The reactions are run under mild conditions, with only a closed reaction vessel required.
Thus, one of the principal objects of the present invention is to provide a new polymeric carbohydrate derivative capable of gelling organic solvents. Another principal object of this invention is to provide a gelling agent for organic solvents that is water insoluble. Still another object is to provide a method of making a gelled organic solvent from methyl hydroxypropyl cellulose acetate. Another object is to provide a method of making an improved gelling agent for organic solvents by the simultaneous hydroxypropylation and methylation of cellulose and continuing the cellulose derivatization by acetylation. Other objects and advantages will become apparent hereinafter.
Gelling of volatile chemicals retards the rate of vaporization allowing only a slow release of vapor. The gelling agent of the present invention is useful in many applications, some of which include gelling jet fuel, soil fumigants, herbicides, paint stripping formulations and cleaning solvents. Some of the organic solvents which the methyl hydroxypropyl cellulose acetate of this invention is capable of gelling include: carbon tetrachloride, toluene, acetonitrile ethylacetate, methyl ethyl ketone, dioxane, dimethyl sulfoxide, dimethyl formamide, pyridine, and benzyl alcohol.
SUMMARY OF THE INVENTION
This invention comprises a water insoluble polymeric carbohydrate derivative, methyl hydroxypropyl cellulose acetate, which is capable of gelling a broad range of organic solvents, and the process of making the same.
DETAILED DESCRIPTION
The product of this invention is a mixed ether ester capable of thickening or gelling a wide variety of solvents. This polymeric gelling agent provides many desirable properties which are lacking in the presently available gelling agents. It is insoluble in water, soluble in organic solvents and is inert, non-ionic and non-hygroscopic. It is easy to handle, creating no dust or bulk problem and no special equipment, such as homogenizers, are needed for dissolution. Solutions and gels may be easily prepared by adding the gelling agent to an organic solvent under high speed agitation. After mixing, the mixture is allowed to stand for about one to ten minutes to complete gelation or thickening. The gel which is formed has a long shelf life, developing no syneresis, and is stable to temperature changes and vibrational influences. The gel has a smooth elastic body but not to the point of excessive stringiness. The thickened solutions exhibit thixotropic or pseudo-plastic properties at low concentrations. This facilitates handling of the thickened solutions in pumping and mixing. Gels can usually be formed at concentrations below 1.5% of gelling agent. The present gelling agent is soluble in a wide range of organic solvents and is an effective thickener or gellant at low concentrations.
Examples of solvents which are capable of being gelled with methyl hydroxypropyl cellulose acetate are seen in Table I. These organic solvents may be esters, ketones, aromatic ring ethers, nitrites, amides, alcohols or halogenated solvents with a solubility parameter of about 8 to about 12.
The solubility parameter is a method of measuring gelling ability of the methyl hydroxypropyl cellulose acetate and is set forth in Polymer Handbook edited by E. H. Immergut, Interscience Publishers (1966). Solubility parameter or δ is a thermodynamic property of solvents and may be used to measure their mutural compatibility. For example, two solvents with the same δ value will be miscible and a solute with the same δ value will be soluble in both, regardless of the nature of the solvents. Once the δ value for a given polymer is determined by dissolution in a few solvents, all other solvents with comparable δ values will also dissolve it.
The term solubility as used in this context has a somewhat different meaning than it conventionally has. Solubility is used generally to indicate the extent of interaction between a solid and a solvent. A piece of solid, when placed in a solvent, will dissolve into the solvent until the saturation point is reached. At that point, the two phases, solid and liquid coexist at equilibrium. The amount of solute in liquid is measured as the solubility of the material in solution. However, there is no such saturation point in the case of the gelling agents of this invention. When immersed in a "compatible" solvent, the gelling agents swell and dissolve. As more and more gelling agent is added, the material will continue to swell and dissolve. When there is insufficient solvent to disassociate completely the polymers, then swelling only occurs. A single phase (solution or gel) is reached at all times. To examine qualitatively the compatibility of a gelling agent, 5 g. of gelling agent is placed in 100 ml. of solvent. It is compatible if only one phase is observed (gel or solution). It is incompatible when the mixture retains two phases.
Table I shows examples of solvents with their corresponding solubility parameter. The methyl hydroxypropyl cellulose acetate gels solvents with a solubility parameter of about 8-12.
TABLE I______________________________________ SOLUBILITYSOLVENTS PARAMETER______________________________________Isoamylacetate 7.8Ethyl acetate 8.4Carbon tetrachloride 8.4Toluene 8.9Methyl ethyl ketone 9.3Methylene chloride 9.7Dioxane 10.0Pyridine 10.3Acetonitrile 11.5Dimethyl sulfoxide 12.0Dimethyl formamide 12.1Benzyl alcohol 12.1______________________________________
The product of this invention is chemically distinct from the product of application Ser. No. 222,660 even though they possess similar properties.
The methyl hydroxypropyl cellulose acetate of this invention has a D.S. of about 0.1 to about 1.0 methyl group, preferably about 0.1 to about 0.5; a D.S. of about 0.8 to about 2.5 acetyl groups, preferably about 1 to about 2; and an M.S. of about 2 to about 8 hydroxypropyl groups, preferably about 3.5 to about 4.5.
The purpose of the following paragraph is to explain the use herein of the term "degree of substitution" (D.S.) and degree of molar substitution (M.S.).
The degree of substitution is defined as the average number of hydroxyl groups substituted per anhydroglucose unit. The maximum number of hydroxyl groups per anhydroglucose is three and therefore the theoretical maximum degree of substitution is also three in the case of monofunctional substituents.
In the case of polyfunctional or polymerizable substituents that can react not only with the hydroxyl groups but also with themselves, the number of substituents is no longer limited by the three available hydroxyl groups on the anhydroglucose unit. The term "degree of molar substitution", (M.S.) is adopted and defined simply as the number of moles of substituent per anhydroglucose unit. There is no theoretical maximum value for the degree of molar substitution, (M.S.).
The amount of polymeric carbohydrate derivative used as a gelling agent is at least about 0.3 grams per 100 ml. of solvent and may be as much as 5 grams per 100 ml. depending upon the desired gel viscosity.
Gels and thickened solutions may be easily prepared by adding the methyl hydroxypropyl cellulose acetate to the solvent under high speed agitation. Heat may be used to speed dissolution. The final gel has a specific gravity substantially that of the solvent being gelled.
The preferred process for making the composition of this invention involves the simultaneous hydroxypropylation and methylation of cellulose with the continued derivatization of cellulose into the acetate ester. Each of these steps may be done independently of each other if desired. That is, the hydroxypropyl cellulose may be obtained from a commercial source and then subjected to the methylation and acetylation procedures.
SPECIFIC EXAMPLES
Following are specific examples showing the method of making methyl hydroxypropyl cellulose acetate and its application in gelling organic solvents.
EXAMPLE NO. 1
The following reactants are placed in a reactor with stirring for 45 minutes at 15° to 30°C.
______________________________________cellulose 40 g.sodium hydroxide 8 g.toluene 470 ml.water 16 g.______________________________________
At the end of the prescribed time, approximately 130 g. of propylene oxide and 5 g. methyl chloride are added to the reactor, the air being displaced from the vessel with nitrogen. The reactor is heated at 60°C. for 1 hour. Thereafter, the temperature is slowly raised to 95°C. over a period of 5 hours.
At the end of this period the reaction is substantially complete. The reactor is cooled to room temperature and the toluene solvent is decanted.
Next, approximately 500 ml. hexane, 120 ml. acetic anhydride and about 120 ml. of a 1:1 (v/v) trimethylamine hexane solution are added to the reactor with stirring for 30 minutes at room temperature.
The final reaction mixture is washed with an aqueous solution of sodium bicarbonate solution and water, then filtered and dried. The methyl hydroxypropyl cellulose acetate is recovered as a white solid.
EXAMPLE NO. 2
This example employs the same conditions as Example No. 1. The primary difference from Example No. 1 is in allowing the toluene to remain in the crude methyl hydroxypropyl cellulose and serve as a solvent during the acetylation. After the acetylation with acetic anhydride, methyl hydroxypropyl cellulose acetate is precipitated by adding 500 ml. hexane and then purified by aqueous sodium bicarbonate solution washing and water washing.
EXAMPLE NO. 3
This example is performed under the same condition as Example No. 1, except that pyridine is used as a catalyst during the acetylation. The crude methyl hydroxypropyl cellulose is treated with 110 ml. of acetic anhydride and 62 g. of pyridine in 500 ml. of hexane. The reaction temperature is kept at 25°C. for 2 hours. The methyl hydroxypropyl cellulose acetate is recovered and has the same properties as the acetate in Example No. 1.
EXAMPLE NO. 4
A slurry of 40 g. of cellulose is mixed with agitation in 24 g. of 33% aqueous sodium hydroxide solution and 480 g. of hexane mixture in a closed reactor provided with a mechanical stirrer. Air in the reactor is displaced with nitrogen. The mixture is agitated over a period of about 45 minutes at 4°-10°C. At this point, 136 g. of propylene oxide and 6.7 g. of methyl chloride are added, the air being displaced from the reactor with nitrogen. The resulting charge is then raised to a temperature of about 60°C. and held at this temperature for one hour, then 75°C. for 3 hours, and 85°C. for 6 hours. At this stage, the reaction mixture contains a slurry of crude methyl hydroxypropyl cellulose.
The crude methyl hydroxypropyl cellulose is then treated with 120 ml. of acetic anhydride and 120 ml. of hexane trimethylamine (1:1 v/v) and allowed to react with stirring at room temperature for approximately 1/2 hour.
After the reaction, the hexane is removed by filtration. The reaction product is washed with 500 ml. of 4% aqueous sodium bicarbonate solution. The product, methyl hydroxypropyl cellulose acetate, is substantially completely soluble in carbon tetrachloride, toluene, acetonitrile, ethyl acetate, methyl ethyl ketone, dioxane, dimethylsulfoxide, dimethylformamide, pyridine, and benzyl alcohol to form smooth solutions. The Brookfield viscosity (spindle No. 3 at 10 rpm) of a 1% dimethylformamide solution at room temperature is 2300 cps.
The methyl hydroxypropyl cellulose acetate is capable of gelling organic solvents with a solubility parameter of about 8 to about 12.
EXAMPLE NO. 5
A slurry of 40 g. of cellulose is added to 400 ml. of 7% aqueous sodium hydroxide solution and stirred for 1 hour at 0°-5°C. Then the excess alkali solution is removed by vacuum filtration using a rubber sheet over the filter to prevent air from passing through the cake, leaving a filter cake weighing 162.5 g. which has an alkali/cellulose ratio of 0.31 and a water/cellulose ratio of 2.3.
This alkali cellulose cake is broken up and placed in the reaction vessel along with 400 g. of toluene and 6 g. of methyl chloride, the air being displaced from the vessel with nitrogen. After the mixture has been stirred for 1/2 hour at room temperature, 800 g. of propylene oxide is added to the reactor. The vessel is then heated gently to 65°-75°C. and held at this temperature for about 6 hours. At this stage, the vessel is cooled to room temperature, the toluene solvent and the unreacted propylene oxide are filtered off. The reaction mixture is neutralized with 85% H 3 PO 4 . The product, methyl hydroxypropyl cellulose, is purified by washing with hot water and then dried at 70°C. under vacuum.
This pure methyl hydroxypropyl cellulose is then acetylated with 58 ml. of acetic anhydride and 20 g. of trimethylamine in 350 ml. of hexane. The resulting charge is allowed to react for 1/2 hour with agitation at room temperature. The product is purified by washing with aqueous sodium bicarbonate solution and water. A methyl hydroxypropyl cellulose acetate is obtained which has the same solubility in various organic solvents as the acetate made from Example No. 1.
EXAMPLE NO. 6
Cellulose in sheet form weighing 39.8 g. is steeped in 12% sodium hydroxide for 20 minutes and then pressed at 5000 psi to obtain a press weight ratio of 1.91. The pressed cake has an alkali/cellulose ratio of 0.16 and a water/cellulose ratio of 0.87 (bone dry cellulose basis).
The alkali cellulose cake is broken up and placed in the reaction vessel with 500 ml. toluene, 6 g. methyl chloride, plus 175 g. propylene oxide, the air being displaced from the vessel with nitrogen. The vessel is then heated to 65° to 75°C. and held at this temperature for 6 hours. The vessel is then cooled to room temperature, and the excess solvent filtered off. The acetylation is carried out by reacting the crude methyl hydroxypropyl cellulose with 200 g. of acetic anhydride and 60 g. of trimethylamine in 600 ml. hexane for 1 hour at 25°C. The acetate has the same properties as the acetate made in Example No. 1. | This disclosure involves the acetate ester of methyl hydroxypropyl cellulose. This particular cellulose ester is useful as a gelling agent for organic solvents. The methyl hydroxypropyl cellulose acetate is prepared by the simultaneous hydroxypropylation and methylation of cellulose and by the continuation of the cellulose derivatization into acetylation. The overlapping relationship of the hydroxypropylation and acetylation processes is found to be efficient and economical in that it eliminates the difficulty of isolation and recovery of the water insoluble methyl hydroxypropyl cellulose. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to an improved method for the removal of non-targeted components from a non-targeted component containing fluid stream. More particularly, the method of the present invention is intended to facilitate the removal of certain non-targeted components from fluid streams using an agent such as open water, seawater, produced water or other water sources.
BACKGROUND ART
[0002] Oil and gas reservoirs often contain very large volumes of carbon dioxide and many of these are located in isolated offshore locations. Due to the location and environment of such offshore gas fields and the quantity of carbon dioxide, the cost of removing and processing the carbon dioxide is significantly higher than it would be otherwise. Some of these oil and gas reservoirs also contain other non-targeted component gases such as hydrogen sulphide, non-targeted produced water and non-targeted solids such as sands which need to be separated from the produced fluid stream and further processed or sequestered.
[0003] This cost is further increased when the greenhouse effects of releasing gases such as carbon dioxide into the atmosphere are considered. Once the greenhouse gas implications and costs are taken into account it becomes apparent that systems which enable the removal and processing or sequestration of the CO 2 and other greenhouse gases such as H 2 S, whilst remaining compact enough for use in offshore locations, will be most favored.
[0004] Seawater or brine has previously been considered as a possible solvent/reactant for scrubbing power station flue gases in a conventional vertical tower scrubbing process located on land. The problems associated with this particular process are the large volumes of seawater required and the associated large vessels and significant pumping power required. Further, water at sea level and atmospheric pressure has a much lower capacity to absorb carbon dioxide than that it does at higher water pressure and lower water temperature.
[0005] Whilst the use of seawater for the removal of greenhouse gases would be advantageous in offshore installations, the large size of the apparatus for conventional vertical tower scrubbing processes makes their implementation highly impractical.
[0006] Further, the offshore location provides additional problems not faced in land installations as a result of greatly reduced system footprint availability and the increased operating pressures, especially in deep water, and the challenges faced with deployment and long term operation without regular vessel inspections.
[0007] Other attempts to use liquid solvents to remove greenhouse gasses from gas streams such as WO 2000074816 have utilised counter-current absorbers. However, these to experience a number of problems. Counter-current systems are heavily limited by gas velocity, due to the fact that above a certain gas velocity, counter-current systems will flood and entrain the liquid in the gas. Additionally, the solvent used (such as amines) will typically need to be regenerated, which requires the addition of further pressure vessels associated with regeneration. It is also the case that the absorbed gas is not easily sequestered.
[0008] Conventional counter-current absorbers are also limited by the fabrication limitations associated with large vessels operating under pressure. For large vessels this is around a design pressure of 100 bar. In order to accommodate this pressure requirement, the large pressure vessels have the following significant engineering and economic impacts:
Weight; High fabrication costs (as special high cost alloys are required for certain applications such as carbon dioxide); Large footprints, making them unsuitable for most offshore applications; and Large Inventory (holding costs).
[0013] There also remain safety concerns associated with the often dangerous, explosive and/or environmentally impacting inventory. In addition to the above problems, such pressure vessels cannot be safely deployed below depths of a few hundred metres.
[0014] Whilst co-current processes, such as those taught by EP 0180670, have been developed, these rely on atomised liquid droplets to perform the mass transfer function. Generally the efficiency of the mass transfer step is increased as the droplet size is decreased, as a higher liquid surface area contact is achieved with many small droplets as opposed to fewer larger ones. This type of process however does require a large vessel diameter to carry out the mass transfer process in order to prevent the droplets from coalescing together. According, these processes to suffer the aforementioned limitations.
[0015] Additionally the counter-current and co-current processes such as taught by WO 2000074816 and by EP 0180670 are not suitable for separating non-target liquids, such as water from the fluid streams produced at oil and gas reservoirs and non-target solids such as produced sands.
[0016] One object of the present invention is to provide a method for the removal of non-targeted components from targeted gas streams which can be utilised in the confined conditions of typical offshore or subsea locations. A further object is that the problems associated with increased operating pressures, deployments and the need for regular vessel inspections will be significantly reduced.
[0017] The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia or any other country or region as at the priority date of the application.
[0018] Throughout the specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
[0019] Throughout the specification, unless the context requires otherwise, the term “gas”, will be understood to be predominantly gas although it may contain some liquids and/or some solids.
[0020] Throughout the specification, unless the context requires otherwise, the term “liquid”, will be understood to be predominantly liquid although it may contain some gas or gases and/or some solids.
[0021] Throughout the specification, unless the context requires otherwise, the term “greenhouse gases”, will be understood to include any one or more of CO 2 , H 2 S, CO, HCl, CH 4 , N 2 O, CCl 2 F 2 , CHClF 2 , CF 4 , C 2 F 6 , SF 6 and NF 3 .
[0022] Throughout the specification, unless the context requires otherwise, the term “inline process”, will be understood to include any process in which the elements of the process are pipe and comply with piping requirements. It will be understood that inline processes are not limited to those which are horizontal or in a straight line, but may include elements of any orientation including vertical elements.
[0023] Throughout the specification, unless the context requires otherwise, the terms “solvent” and “reactant”, will be understood to include any suitable fluid which can be any one or more of water, seawater, treated water, open source water, brine, and other aqueous and non-aqueous absorbents for gases including CO 2 and other gases.
[0024] Throughout the specification, unless the context requires otherwise, the term “fluid”, will be understood to include any combination of gases, liquids and fluidised solids, including natural gas, condensate, oil and other hydrocarbons, water and sand.
[0025] Throughout the specification, unless the context requires otherwise, the term “non-targeted component”, will be understood that or those components not desired to be present above certain levels in the target fluid stream produced after passing through the invention.
[0026] Throughout the specification, the term “non-targeted” should not be construed to mean of no commercial value. The non-targeted components may have significant commercial value. The terms “non-targeted” and “targeted” are used to distinguish one component or combination of components from another component or combination of components.
[0027] Throughout the specification, unless the context requires otherwise, the term “purified gas”, will be understood to mean gas with a reduced level of non-targeted components.
[0028] Throughout the specification, unless the context requires otherwise, the term “wet gas”, will be understood to mean gas after the solvent has been added into it.
[0029] Throughout the specification, unless the context requires otherwise, the term “dry gas”, will be understood to mean gas after the bulk of the solvent has been separated from it.
[0030] Throughout the specification, unless the context requires otherwise, the term “rich”, will be understood to mean containing a high level of non-targeted component.
[0031] Throughout the specification, unless the context requires otherwise, the term “lean”, will be understood to mean containing a low level of non-targeted component.
SUMMARY OF INVENTION
[0032] In accordance with the present invention there is provided an improved method for the removal of non-targeted components from a non-targeted component containing gas stream, the method comprising the steps of:
i) contacting the non-targeted component containing gas stream with a fluid solvent stream; ii) passing the product of step i) through a co-current phase separation step to produce both a non-targeted component containing solvent stream and a partially purified gas stream; iii) passing the partially purified gas stream product of step ii) through a mass transfer step to produce a wet gas product; and iv) passing the wet gas product of step iii) through a final co-current phase separation step to produce a purified gas stream.
[0037] In one form of the present invention the wet gas product of step iii) is passed through at least one further combination of an inline co-current phase separation step and an inline mass transfer step before proceeding to step iv).
[0038] In one form of the present invention, the method further comprises the step of:
Separating the non-targeted component containing gas stream from a fluid stream by way of an initial co-current phase separation step in order to separate any residual liquids or solids,
prior to the step of:
Contacting the non-targeted component containing gas stream with a liquid solvent stream
Preferably, the separated liquids and solids may undergo further phase separation to separate produced water and/or sand before the targeted liquids are sent downstream for further processing and/or collection.
[0041] Preferably, the non-targeted components are carbon dioxide, hydrogen sulphide and/or other greenhouse gases.
[0042] Preferably, the co-current phase separation step, the mass transfer step and the final co-current phase separation step are all inline processes.
[0043] Preferably, the inline co-current phase separation step ii) comprises passing the solvent containing gas stream through an inline co-current phase separation apparatus to separate the gas stream from the non-target component containing fluid solvent.
[0044] Preferably, the inline mass transfer step iii) comprises passing the gas stream through an inline mass transfer apparatus, in which it is contacted with a fine spray of additional fluid solvent.
[0045] Preferably, the fluid solvent is high pressure water. More preferably, the fluid solvent is an open water source. Still preferably, the fluid solvent is sea water or high pressure produced water. The water is preferably drawn from locations which contain low levels of non-targeted components and releasing the component rich water at deep levels where solubility is higher.
[0046] Preferably, the fluid solvent is low temperature, high pressure water. Still preferably, the fluid solvent is low temperature, high pressure open source water, sea water or produced water. Still preferably, the water is drawn from locations which contain low levels of non-targeted components.
[0047] Preferably, fresh (uncontacted) fluid solvent is introduced at each stage to maximize each mass transfer stage's efficiency.
[0048] In a further embodiment of the present invention, the non-targeted component containing gas stream is contacted with low temperature, high pressure water, whilst the partially purified gas stream of step (iii) is contacted with an alkylamine. Preferably, the alkylamine is selected from a group containing monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropylamine (DIPA) or diglycolamine (DGA).
[0049] Preferably, the non-targeted component containing solvent is released in deep water areas, so that the non-targeted components may be sequestered. Still preferably, the non-targeted component containing solvent is progressively released over a length of pipeline or injected into a suitable surface reservoir for enhanced oil recovery and/or sequestration.
[0050] Preferably, the non-targeted component containing fluid solvent may be injected into a natural reservoir for sequestration purposes and/or enhanced oil and/or gas production purposes.
[0051] In a further embodiment of the present invention, the solvent separated at each inline co-current phase separation step may be passed through a regeneration step, so that it may be recycled for use in the inline mass transfer step iii).
[0052] In a further embodiment of the present invention the solvent is passed through inline separation devices to remove solid non-targeted components from the solvent prior to being contacted with the gas stream.
[0053] In accordance with the present invention there is further provided an improved method for the production of methane from methane hydrate reserves, the method comprising the steps of:
i) contacting a non-targeted component containing gas stream with a fluid solvent stream; ii) passing the product of step i) through a co-current phase separation step to produce both a non-targeted component containing solvent stream and a partially purified gas stream; iii) passing the partially purified gas stream product of step ii) through a mass transfer step to produce a wet gas product; iv) passing the wet gas product of step iii) through a final co-current phase separation step to produce a purified gas stream; and v) injecting the non-targeted component containing solvent stream into a methane hydrate reserve to produce methane and a hydrate.
[0059] Preferably, the non-targeted component present in the non-targeted component containing gas stream includes CO 2 .
[0060] Preferably, only the concentrated the non-targeted component containing solvent stream of stage (ii) is injected into the methane hydrate reserve.
[0061] In one form of the present invention, the method further comprises the step of:
Separating the non-targeted component containing gas stream from a fluid stream by way of an initial co-current phase separation step in order to separate any residual liquids or solids,
prior to the step of:
Contacting the non-targeted component containing gas stream with a liquid solvent stream
[0064] In accordance with the present invention there is still further provided a means for the removal of non-targeted components from a fluid stream which have been dissolved in a fluid solvent, the means comprising:
i) an initial co-current phase separation apparatus; ii) an mass transfer apparatus; and iii) a final co-current phase separation apparatus,
whereby a purified gas stream and a non-targeted component rich solvent stream are produced.
[0068] Preferably, the initial co-current phase separation apparatus, the mass transfer apparatus and the final co-current phase separation apparatus are arranged in series. Still preferably, they are all inline with the fluid stream.
[0069] In one form of the present invention there is provided at least one further combination of inline co-current phase separation apparatus and inline mass transfer apparatus before the final inline co-current phase separation apparatus.
[0070] Preferably, the non-targeted components are carbon dioxide, hydrogen sulphide or other greenhouse gases.
[0071] Preferably, the fluid solvent is low temperature, high pressure water. More preferably, the fluid solvent is low temperature, high pressure open source water, sea water or produced water. Still preferably, the water is drawn from locations which contain low levels of non-targeted components and the non-targeted component containing water is released at deep levels where solubility is higher.
[0072] Preferably, the non-targeted component containing fluid solvent may be injected into a natural reservoir for sequestration purposes and/or enhanced oil and/or gas production purposes.
[0073] Preferably, the non-targeted component containing solvent is progressively released over a length of pipeline.
[0074] In a further form of the present invention, the separated solvent product of each inline co-current phase separation apparatus may be passed through regeneration apparatus, so that it may be recycled for use in the inline mass transfer apparatuses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:
[0076] FIG. 1 is a schematic representation of a flow sheet depicting a method for the removal of non-targeted components from a gas stream in accordance with the present invention;
[0077] FIG. 2 is a cross sectional view of an inline co-current phase separation apparatus in accordance with the method of FIG. 1 ; and
[0078] FIG. 3 is a cross sectional view of an inline mass transfer apparatus in accordance with the method of FIG. 1 .
DESCRIPTION OF EMBODIMENTS
[0079] In FIG. 1 there is shown a method 10 for the removal of non-targeted components from a fluid stream, for example either atmospheric or non-atmospheric gas streams. In general terms, the method 10 utilises a high pressure, low temperature open water source as a solvent in order to remove greenhouse gases from a gas stream.
[0080] A gas or multi-phase fluid stream 12 may be combined with one or more other gas or multi-phase fluid streams 14 to produce a combined multi-phase fluid stream 16 . The combined multi-phase stream 16 is then directed to a first co-current phase separation apparatus, for example an inline co-current phase separation apparatus 18 , wherein the combined multi-phase stream 16 is separated into a predominantly gas stream 20 and a predominantly liquid stream 22 . The predominantly gas stream 20 is then directed to a first mass transfer apparatus, for example an inline mass transfer apparatus 24 , where it is spray contacted with a solvent stream 26 to produce a mixed phase stream 28 .
[0081] The mixed phase stream 28 is then directed to a second co-current phase separation apparatus, for example an inline co-current phase separation apparatus 30 , wherein the mixed phase stream 28 is separated into a gas stream 32 and a solvent stream 34 .
[0082] The gas stream 32 is then directed to a second mass transfer apparatus, for example an inline mass transfer apparatus 36 , where it is spray contacted with solvent stream 38 to produce a mixed phase stream 40 .
[0083] The mixed phase stream 40 is then directed to a final co-current phase separation apparatus, for example an inline co-current phase separation apparatus 44 , wherein the mixed phase stream 40 is separated into a purified gas stream 46 and a solvent stream 48 . The purified gas stream 46 then can be piped or otherwise transported for storage and/or further processing.
[0084] The predominantly liquid stream 22 is then directed for downstream transportation which can include for injection into a reservoir or piping for storage and/or further processing and this may be facilitated by pump means 50 as required.
[0085] If the solvent is to be regenerated rather than released or sequestered Solvent streams 34 and 48 may be passed to regeneration means 52 which may involve de-pressurization with release of non-targeted components to produce a regenerated solvent stream 54 . The regenerated solvent stream 54 is directed for use at inline mass transfer apparatuses 24 and 36 by way of pumping means 56 .
[0086] The method 10 of the present invention as hereinbefore described is a two stage method. It is envisaged that the number of phase separation/mass transfer steps may be increased or decreased to one mass transfer step and one phase separation depending on the composition of the flow streams and the level of separation required.
[0087] It is further envisaged that whilst highly applicable to natural gas and also oil and/or condensate and natural gas streams, the method of the present invention may be used for the removal of carbon dioxide and other greenhouse gases from the coal seam gas streams, biogas streams, steel works, power station flue gases and other gas or fluid streams, including from the atmosphere, where these gas or fluid streams contain undesirable levels of non-targeted components and where a suitable solvent, such as a high pressure, low temperature water source, is available in sufficient quantities.
[0088] It is further envisaged that the method of the present invention may be used for the removal of any targeted component from any fluid containing the targeted component where there is a suitable solvent for the targeted component.
[0089] In FIG. 2 there is shown an inline phase separating apparatus 100 for use in a method for the removal of non-targeted components from a gas stream, for example atmospheric or non-atmospheric gas streams. The inline phase separating apparatus 100 utilises cyclonic separation to generate high G-forces in order to separate liquid from a gas stream.
[0090] The inline phase separating apparatus 100 comprises a main separation section 102 in which the liquid is extracted from the wet gas stream entering at the wet gas inlet 104 to produce a predominantly single phase gas stream at the dry gas outlet 106 . The separated liquid is directed to a liquid outlet stream 108 by way of liquid drains 110 , 112 , 114 . Therefore the unit is fully capable of producing two predominantly single phase outlet streams from one multiphase inlet stream. Upon entering the main section 102 , the wet gases velocity is decreased due to the increase in the pipe's cross section. This allows large liquid particles to drop to the bottom of the vessel due to gravitational effects and such may be drained from the unit by way of liquid drain 110 . The remaining gas, which contains a fine mist of liquid particles, then proceeds through a cyclonic spinner 116 . This forces the gas to spin, which will act to agglomerate the smaller liquid droplets and force them to the outer edge of the flow stream due to their increased mass over the gas particles. This allows the droplets to be caught radially and drained from the vessel by way of liquid drains 112 and 114 . The remaining dry gas then exits the separator by way of dry gas outlet 106 .
[0091] The inline phase separating apparatus 100 may be manufactured from suitable materials including any material used in offshore applications and is also suitable for subsea installation. If sand is expected, erosion can be prevented by applying a coating such as tungsten carbide.
[0092] The inline phase separating apparatus 100 may accommodate both thin and thick liquid films through the use of a gas recycle loop (not shown). Thin liquid films are on the wall of the cyclone are generated by low liquid loadings and as a result of the friction with the cyclone' wall they have a low momentum.
[0093] As the gas approaches the gas outlet cone of the cyclone it has to constrict and as a consequence a local “negative” pressure field is set up in addition to a gas recirculation. This in combination with the low liquid film momentum leads to an accumulation of the liquid, which subsequently leads to increased liquid carryover from the cyclone. By adding the recycle the “negative” pressure fields and gas recirculation zones are not formed as the gas is allowed to flow in the annulus between the gas outlet and the wall of the cyclone.
[0094] The use of the gas recycle loop is not required for higher liquid loading as the thin film effect will not be as problematic. Due to the increased quantities of the liquid required for the mass transfer process of the present invention it is envisaged that the liquid loadings will be typically high and that the gas recycle loop will not be required during normal operation.
[0095] In FIG. 3 there is shown an inline mass transfer apparatus 200 for use in a method for the removal of non-targeted components from a gas stream, for example atmospheric or non-atmospheric gas streams. The inline mass transfer apparatus 200 introduces a smaller liquid phase 202 into a gas stream 204 through a liquid injector pipe 206 that discharges a fine spray of the liquid phase 202 by way of a liquid spray nozzle 208 . This ensures the uniform introduction of the liquid phase 202 into the gas stream 204 . The liquid and gas phases are contacted by static mixing elements 210 . Fine liquid stream 202 droplets are developed by the high velocity gas/liquid streams resulting in a greater amount of liquid phase 202 surface area exposed to the gas phase stream 204 . The static mixing elements 210 produce a mixed phase output stream 212 .
[0096] The use of static mixer elements 210 provides increased mass transfer between the liquid phase 202 and the gas stream 204 . The pressure drop is also minimized due to parallel paths offered to the static mixing elements 210 . The decreased pressure drop lowers the required horsepower, average requirements and therefore utility costs. It is envisaged that the mixing elements 210 may be removed and through the use of fine droplets, similar mass transfer efficiencies may be achieved.
[0097] It is further envisaged that the removed non-targeted components may be sequestered in deep water areas, where solubility is higher than at sea level. The non-targeted components may further be sequestered as a gas hydrate in deep water, by injecting the non-targeted component gas into methane hydrate reserves. In doing so the non-targeted component gas molecules, for example CO 2 with or without additional non-targeted components will exchange with the methane in the hydrates, forming for example a CO 2 hydrate, and thereby releasing methane from the methane hydrate reserves.
[0098] The process of the present invention may be implemented in a variety of locations in the overall process of an upstream oil and/or gas production facility. However, it is envisaged that there are two main locations where this technology is most likely to be employed, being subsea and/or on a topsides facility such as a platform or floating production vessel.
System Configurations
[0099] It is envisaged that the method and apparatus of the present invention may be implemented in a number of advantageous configurations. These include:
Transmission Pipelines
[0100] In such a configuration the method and apparatus of the present invention is implemented in the form of transmission line which may supplement already established pipeline used to transport gas streams. Such a configuration provides a pipeline that has multiple injection point by which fresh or lean fluid solvent streams may contact the non-targeted component rich gas stream. Downstream from such injection points there are provided separation/extraction points for the non-targeted component rich solvent stream. Given that such transmission pipelines extend across large distances, the contact time of the non-targeted component containing gas stream and the fluid solvent stream is extended, thus substantially improving the absorption of the non-targeted components into the fluid solvent.
Modular Systems
[0101] In such a configuration the method and apparatus of the present invention are configured in the form of a compact modular multi-stage inline pipe based system. In such a configuration it is envisaged that the apparatus would comprise vertical orientation stages, followed by subsequent separation/extraction stages. In such a configuration, the apparatus of the present invention may be implemented in environments where space is limited, such as an offshore oil rig. The modular design of apparatus may be inserted in line with existing equipment on site.
[0102] The method of the present invention may implemented in a number of locations on an existing topsides facility, the following location is provided by way of example:
Immediately Upstream or Downstream of the Topsides Chokes
[0103] The benefit of this location is to reduce the gas loading to the downstream processes. For example, one of these processes could be gas drying through the use of MEG or TEG. Alternatively, in the case of an existing facility the total production throughput of the platform may be increased.
High Pressure Solvent
[0104] The performance of the system is greatly improved when the pressure of the fluid solvent is increased, the temperature is lowered and the the concentration of the component to be absorbed is low. Thus to improve the efficiency of the process it is envisaged that the inclusion of an apparatus, such as a pump, to increase the pressure of the fluid solvent may be included. When operating in subsea environments, the fluid solvent is preferably obtained from deep water sources. Such deep sources, such as deep ocean water, are high pressure, low temperature and have a low carbon dioxide concentration.
[0105] If implemented subsea, it is expected this will be between the wellhead and the topside facility chokes. Ideally it would be located as close to the well head as possible to minimise slugging flow entering the initial stage of separation. This will provide additional benefits of improved liquid from gas separation and a reduced line pressure drop.
[0106] When locating the unit subsea, except where seawater is utilised as a solvent, it is likely that the regeneration of the solvent/reactant that is selected may need to be handled on a topside or onshore facility.
[0107] The process and associated apparatus of the present invention has a number of advantages over the prior art. Importantly, the pipelines are able to be fabricated to operate safely at pressures of over 200 bar and as such, can be deployed below depths of 1000 m below sea level. Accordingly, the aforementioned advantages of utilising high pressure deep ocean water can be achieved. Typically the absorbed gas may also be sequestered directly into seawater at deep sea levels or injected in storage reservoirs, thus preventing their release into the atmosphere.
[0108] As the method of the present invention is an inline process, it is far less limited by gas velocity than counter-current systems. Advantageously, the inline process may not require the regeneration of the solvent. As opposed to conventional systems incorporating large pressure vessels the compact inline systems utilised in the present co-current process are characterised by:
[0109] light weight
[0110] lower fabrication costs
[0111] small footprints
[0112] small inventory (reduced holding cost and improved safety)
[0113] overall improved safety; and
[0114] a low inspection and regulation regime in comparison with pressure vessels.
[0115] Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention. | An improved method for the removal of non-targeted components from a non-targeted component containing gas stream, the method includes the steps of: (i) contacting the non-targeted component containing gas stream with a fluid solvent stream; (ii) passing the product of step i) through a co-current phase separation step to produce both a non-targeted component containing solvent stream and a partially purified gas stream; (iii) passing the partially purified gas stream product of step ii) through a mass transfer step to produce a wet gas product; and (iv) passing the wet gas product of step iii) through a final co-current phase separation step to produce a purified gas stream, wherein the method is performed in a subsea location. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for continuous mercerization specifically of a long circular cloth.
It has hitherto been well-known to the public a process for mercerizing textile products which are made of yarn, cloth, circular cloth knitted in a form of a cylindrical shape. According to prior arts, however, it has rather been difficult to mercerize continuously as well as uniformly the foregoing circular cloth, because of the fact that, in the course of treatment under mercerization, cloth to be treated is generally subjected to impregnation with caustic solution and is squeezed of said impregnated solution to a predetermined quantity, then put under tension with timing adjustment and finally subjected to a rinsing treatment. Further, when the cloth to be treated is circular knitted article, the edge of circular knitted article to be treated is apt to be impregnated unevenly with said caustic solution resulting in appearance of creases or pleats thereon, and moreover, causing unbalanced tension to be exerted upon the whole width of the treated article in the stage of squeezing the treating solution or the stage of transferring the circular knitted article by means of guide rolls or the stage of loading the tension on the treated article, thus said long circular knitted article cannot be mercerized continuously and uniformly.
The above-mentioned drawbacks in the process for carrying out mercerization of long circular knitted articles according to the prior arts are the problem to be solved urgently.
SUMMARY OF THE INVENTION
The present invention has its object to provide an apparatus for mercerizing circular knitted articles, continuously as well as uniformly to assure that the circular knitted articles can be impregnated uniformly with caustic solution in a predetermined quantity, and the whole parts of the circular knitted articles impregnated with caustic solution are subjected to the timing treatment under an uniform tension, and the circular knitted articles thus treated are subjected to the rinsing treatment efficiently in a short period of time.
The present invention will now be described with reference to the attached drawings by way of example in a form of embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an apparatus for mercerizing circular knitted articles applicable to the process according to the present invention showing the mechanism in the arrangment of the whole constitutional elements,
FIG. 2 is a vertical sectional view of a rinsing tank in an enlarged scale, and
FIG. 3 is a side view of a dancer roll in an enlarged scale showing the detailed structure thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, the reference numeral 1 designates circular knitted articles in a flat shape, and the circular knitted articles 1 are initially fed into a first vessel 2 filled with alkali solution arranged in the alkali treating step of process (A). The concentration of the solution filled in said alkali solution vessel 2 is preferably about 27-15%, and the temperature of said solution is desirably in the range from 0° to 50° C. The circular knitted articles 1 fed into the alkali solution vessel 2 is subjected to impregnation abundantly with an excessive amount of solution while being transferred within the solution in a vertically zigzag course introduced by means of guide rolls 3 arranged at the inner part of the alkali solution vessel 2, subsequently the circular knitted articles 1 are discharged from said vessel 2. However, just before the discharge from said vessel 2, said circular knitted articles are blown at the inner part thereof with air blast from an air injection pipe 4 and are expanded to form a cylindrical shape to be stood upright and transferred in an upward direction. The circular knitted articles thus expanded are pressed by means of a pair of pressure rolls 5 each oppositely disposed leaving a space therebetween, thereby the circular knitted articles 1 are loaded with tension in the transverse direction thereof so as to be effectively permeated with alkali solution into the internal part of said circular knitted articles.
In the next step, the circular knitted articles are squeezed of the solution impregnated therewithin by means of pinch rolls 6 and are fed into a second alkali solution vessel 2' to be subjected to the treatment with alkali solution again in the same way as in the initial stage, subsequently fed into a third alkali solution vessel 2" to be treated with alkali solution in the same as the foregoing. The circular articles treated with alkali solution in the alkali treating step (A) are henceforth transferred to a timing treatment station 7 equipped with a number of guide rolls and are subjected to a reaction treatment, then forwarded to the step (B) for recovering the alkali solution. In the alkali solution recovering step (B), the circular knitted articles are initially fed into a first alkali solution recovering vessel 8, within which the circular knitted articles are treated with water at a temperature in the range of 0°-100° C., subsequently just before the discharge from the recovery vessel 8, the circular knitted articles 1 are blown at the inner part thereof with air blast from an air injection pipe 4 to be expanded into a form of a cylindrical shape, then the circular knitted articles thus expanded are sprayed around the outer periphery thereof with solution poured down from a ring shower pipe 9 disposed to encompass the expanded cylindrical knitted articles so as to wash out effectively the alkali solution contained within the expanded knitted articles. In the next stage, after having passed through the pinch rolls 6, the circular knitted articles are subjected to a treatment within a second alkali solution recovering vessel 8' and a third alkali solution recovering vessel 8" in sequence for the recovery of the alkali solution contained therewithin in the same way as in the initial stage, thus the treatment in the alkali solution recovering step (B) is terminated. In the further subsequent stage, the circular knitted articles thus treated for alkali solution recovery are fed to the rinsing step (C) wherein a number of rinsing vessels 10 are disposed in a multistage arrangement which are filled with water having a temperature ranging from 0° to 100° C., each of the rinsing vessels 10 is provided therewithin guide rolls 3 for transferring the circular knitted articles to be guided in a vertically zigzag course as well as air injection pipes 11 for supplying air at the junctions between the guide rolls 3 and the circular knitted articles. Furthermore, within each rinsing vessel 10 an air injection pipe 4 is provided to supply air to the inner part of the circular knitted articles just before being discharged from the vessel 10. Accordingly, the circular knitted articles are expanded into a form of a cylindrical shape due to air sprayed from the air injection pipe 4 and are subjected to stretching treatment so as to have an extended width thereof in the transverse direction by means of tentering rolls 12, and further squeezed of the water content by means of pinch rolls 6, and then fed into the other rinsing vessel 10 disposed at the subsequent stage wherein the circular knitted articles are subjected to the rinsing treatment once more just in the same way as in the foregoing procedure, thus the rinsing treatment is completed before the circular knitted articles have passed throughout all the rinsing vessels 10.
As described hereinbefore, the mercerization of circular knitted articles according to the present invention comprises the step (A) for treating the articles with alkali solution wherein the alkali solution is repeatedly applied for several times to the circular knitted articles under tension loaded thereon in the longitudinal as well as transversal directions thereof, the timing treatment station 7 for imparting the reaction to the circular knitted articles which have passed through the step (A) of treating with alkali solution, the step (B) for recovering alkali solution wherein the alkali solution impregnated within the circular knitted articles thus subjected to the reaction treatment is repeatedly recovered for several times, and the rinsing step (C) wherein the circular knitted articles removed of impregnated alkali solution therefrom are washed repeatedly. However, the apparatus applicable to the mercerization according to the present invention has the following enumerated characteristics in view of construction to constitute the apparatus for carrying out the step (A) of treatment with alkali solution, the step (B) of recovering alkali solution from said circular knitted articles and the rinsing step (C) respectively described hereinbefore. In other words, for the sake of preventing appearance of nip marks on both edges of the circular knitted articles due to constant pleats formed by folding at both sides of the articles as well as uneven treatment with alkali solution on the whole parts thereof when the circular knitted articles are merely transferred under pressure by means of guide rolls or pinch rolls with no provision of any means as a countermeasure for preventing the aforementioned defects. So that, taking the foregoing viewpoint into consideration, the present invention is completed to eliminate the aforementioned defects by staggering the pleats formed on both sides of the circular knitted articles with the help of torsion generated at the expansion of the circular knitted articles into a form of a cylindrical shape while they are transferred from one solution treatment vessel arranged in the initial stage to the other solution treatment vessel disposed in the subsequent stage.
When the circular knitted articles expanded into a form of a cylindrical shape are nipped by a pair of pressure rolls 5 and a pair of tentering rolls 12 respectively, the cylindrically expanded knitted articles are subjected to pressure exerted upon an alternative roll of the paired pressure rolls and tentering rolls to move it obliquely so as to generate torsion on the cylindrically expanded periphery of the knitted articles and to displace the location of pleats formed thereon, thereby staggering of pleats on the expanded knitted articles can favourably be fulfilled.
As an additional result obtained according to the present invention, the ring shower pipes 9 equipped in the alkali solution recovering step (B) to encompass the circular knitted articles are subjected to a spray treatment where solution or liquid is sprayed over the outer periphery of the circular knitted articles having the cylindrically expanded shape, wherefore the good permeability of the sprayed liquid at the outer periphery of said expanded knitted articles results in fulfilment of efficient recovery of the alkali solution, that is, thorough wash-out of the alkali solution.
Moreover, within each of the rinsing vessels 10 disposed in the rinsing treatment step (C), since the air injection pipes 11 are mounted adjacent to the guide rolls 3, blast air blown from the air injection pipes 11 is supplied to the junction between the guide rolls 3 and the knitted articles to trespass between meshes of the knitted articles due to the pressure of the guide rolls forcedly contacting the knitted articles, whereby the rinsing liquid is also caused to trespass between the meshes of the knitted articles with the help of the air permeation action, so that an effective rinsing treatment can advantageously be carried out.
Besides, the reference numeral 14 represents a dancer roll interposed between every two liquid vessels arranged adjacent to each other, and the dancer roll 14 is pivoted to an arm 16 at one end thereof, the arm 16 is pivotally supported at nearly the middle part thereof by a fulcrum shaft 15 as shown in FIG. 3, and at the other end of the arm 16 is mounted with a weight 17 which can adjust the swinging boundary of the arm in the axial direction thereof. Therefore, the tension loaded on the knitted articles to be treated can automatically be adjusted by controlling the location of the weight 17.
In short, features of the present invention lies in that the mercerization of circular knitted articles can effectively be carried out because the caustic solution is applied to the circular knitted articles to be treated in a form of an expanded shape, namely, under the loaded condition in the longitudinal as well as transversal direction thereof, and in the course of transferring the circular knitted articles to the subsequent stage in sequence, the knitted articles are given somewhat a slight torsion so as to stagger the location of pleats formed by folding the knitted articles at both side fringes thereof, whereby uniform mercerization of the whole parts of the circular knitted articles can be achieved. Further, in the course of the alkali solution recovering step (B), the ring shower pipes are employed, moreover, in the course of the rinsing treatment step (C), the blast air is adapted to be sprayed between the guide rolls and the circular knitted articles within each of the rinsing vessels so as to remove the alkali solution effectively as well as to wash out efficiently the circular knitted articles with only a small consumption of rinsing water and rinsing hot water for obtaining the desired objects of the present invention. | A process and apparatus for mercerizing circular knitted articles, continuously as well as uniformly to assure that the circular knitted articles can be impregnated uniformly with caustic solution in a predetermined quantity, and the whole parts of the circular knitted articles impregnated with caustic solution are subjected to the timing treatment under an uniform tension, and the circular knitted articles thus treated are subjected to the rinsing treatment efficiently in a short period of time. | 3 |
CROSS REFERENCE TO RELATED U.S APPLICATION
[0001] This patent application relates to, and claims the priority benefit from, U.S. Provisional Patent Application Ser. No. 60/525,832 filed on Dec. 1, 2003, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and device used in medical imaging. In particular, the invention is related to a method and device for enabling reduced motion-related displacement artifacts in parallel magnetic resonance imaging.
BACKGROUND OF THE INVENTION
[0003] Magnetic Resonance Imaging (MRI) is based on the absorption and emission of energy in the radio frequency range. A patient is placed in a magnetic resonance scanner that provides a uniform magnetic field that causes the alignment of the moments of the magnetic spin of atoms contained within the patient. The magnetic resonance scanner further provides multiple coils that apply a transverse magnetic field, generated by RF pulses, to the patient such that the aligned moments rotate or tip thereby exciting the spins of the atoms. The excited spins of the atoms generate a signal that is detected by imaging coils contained within the magnetic resonance scanner. The data obtained by the imaging coils is collectively referred to as k-space data which comprises multiple lines or rows of data called phase encodes or echoes. A set of k-space data is acquired for each image frame and converted to an image by applying a Fast Fourier Transform.
[0004] One of the major recent advances in MRI has been the development of “parallel imaging with sensitivity encoding” using multiple radio frequency (RF) coil elements to reduce echo train lengths in multi-echo (e.g. fast spin echo and echo planar imaging) and echo numbers in single echo (e.g. spin echo and gradient recalled echo) MRI scans, with associated improvement in image sharpness and acquisition speed. This methodology has been commercialized by at least three major MRI vendors (Philips, GE, Siemens) and marketed as “SENSE”, “ASSET” or “iPAT” products.
[0005] In the parallel imaging methodology, only part of the k-space data (i.e. under-sampling) is used to generate the MRI images with the effect of reducing the field of view, leading to foldover or aliasing. Using multiple receiver coils each with different (and known) spatial sensitivities allows unfolding of the overlapping data and reconstruction of the full field of view image. However, when the under-sampled k-space data is converted to an MRI image, the resulting images have aliasing defects called artifacts or ghost artifacts. Several image processing techniques have been developed to reduce the affects of ghost artifacts such as the SENSE and SMASH methods in which complex data from the multiple imaging coils are obtained in parallel and weighted in such a way to suppress under-sampling artifacts in the final reconstructed image. The weighting provides spatial filtering which is done in the k-space domain (as in the SMASH method) or in the image domain (as in the SENSE method).
[0006] The complex weights that are used in the SMASH and SENSE methods are related to the coil sensitivities of the imaging coils. The coil sensitivity depends on the proximity of the imaging coils to the patient. Furthermore, it is common practice to place the imaging coils as close to the patient as possible to increase the Signal-to-Noise ratio of the acquired data. Accurate knowledge of coil sensitivities is crucial for parallel MRI, and errors in calibration represent one of the most common and the most pernicious sources of error in parallel image reconstructions. Accordingly, these techniques rely on the “calibration” or “sensitivity encoding” of the multi-coil imaging array (typically achieved by means of a low-resolution scan of the object with individual coil images stored separately). Subsequent multicoil or “parallel” imaging requires this calibration scan data during the reconstruction process to deliver the final image, without foldover or aliasing artifact. Calibration is done before, and/or during, and/or after obtaining imaging data and it is assumed that the sensitivities of the coils remain static during data acquisition or between calibration data and image data acquisition. However, in practice if the coil moves during data acquisition, for example due to breathing, the estimated coil sensitivities will be compromised, ghost artifacts will be generated and the resulting image quality will degrade.
[0007] An attractive opportunity for parallel imaging exists in the abdomen and pelvis, where scans are typically limited in quality by the requirement for acquisition to be completed during a single period of suspended respiration (breath-hold). Since parallel imaging increases acquisition speed and/or decreases echo train length, improved image quality can be obtained within the same (typically 20-30 sec) period of scanning. However, most multi-element RF coils for imaging of the abdomen are of a flexible design, typically tightly coupled to the patient abdomen (to achieve maximum signal to noise ratio). As such the RF imaging coils are physically displaced by normal and abnormal patient motion (such as respiration). Accordingly, the problem of varying coil sensitivity is particularly pronounced for imaging of the abdomen, where calibration scans and images are typically acquired during separate periods of suspended respiration (breath-holds) which are rarely precisely reproducible. In fact, the problem is so severe that the ghost artifact mechanism may impose a limitation on the use of these accelerated imaging methods in some settings.
[0008] Approaches to achieve more uniform breath-holds have been proposed to address this issue such as providing feedback of abdomen wall position to the patient. However, these approaches are limited by patient compliance and reproducibility. Further, respiration is only one source of coil displacement. Other applications of MR imaging such as “interventional” or study of joint kinematics involve other types of motion and hence cannot use an approach related to minimizing coil movement due to respiration.
SUMMARY OF THE INVENTION
[0009] In accordance with a first aspect, the present invention provides several embodiments of a device for physically separating RF imaging coils from any source of movement, thereby eliminating any potential coil-displacement related reconstruction effect or artifact. The device can be used to enable parallel imaging of the abdomen, pelvis and other moving body parts such that normal or abnormal patient movement does not displace the coil elements between the calibration scan and the imaging scans.
[0010] In one aspect of the invention there is provided a method of parallel magnetic resonance imaging, comprising the steps of placing a patient on a magnetic resonance imaging (MRI) table and positioning anterior coil elements of a RF multi-coil imaging array around the patient at a sufficient distance so that the patient does not contact or otherwise move the coils, then performing a calibration scan of the multi-coil imaging array and storing calibration scan data; performing a scan with the multi-coil imaging array and obtaining imaging data of a selected part of a patient's body and storing the imaging data. The calibration scan data and the imaging data is processed to produce a final MRI image of the selected part of a patient's body.
[0011] In another aspect of the invention there is provided a device for retrofitting to a magnetic resonance imaging apparatus for physically separating RF imaging coils from any source of movement by a patient thereby eliminating any potential coil-displacement related reconstruction effect or artifact in parallel magnetic resonance imaging, comprising:
rigid support members being attached to a magnetic resonance imaging apparatus, an RF multi-coil imaging array being attached to the rigid support members with the rigid support members being positioned with respect to a patient lying on a magnetic resonance imaging (MRI) table so that the RF multi-coil imaging array is positioned at a sufficient distance from the patient so that the patient does not contact or otherwise move the coils during movement, voluntary or involuntary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings which show a preferred embodiment of the present invention and in which:
[0014] FIG. 1 is a block diagram of an embodiment of a coil immobilization device in accordance with the present invention;
[0015] FIG. 2 is a block diagram of an alternative embodiment of a coil immobilization device in accordance with the present invention;
[0016] FIG. 3 is a block diagram of another alternative embodiment of a coil immobilization device in accordance with the present invention;
[0017] FIG. 4 is a block diagram of another alternative embodiment of a coil immobilization device in accordance with the present invention;
[0018] FIG. 4 b is a perspective view of another alternative embodiment of a coil immobilization device accordance with the present invention;
[0019] FIG. 4 c is a perspective view of an MRI apparatus which has been retrofitted with the coil immobilization device shown in FIG. 4 b;
[0020] FIG. 5 is a diagram illustrating a water phantom due to the effects of object displacement with and without a coil immobilization device;
[0021] FIG. 6 is another diagram illustrating a water phantom due to the effects of object displacement with and without a coil immobilization device;
[0022] FIG. 7 is a diagram illustrating MRI images obtained with and without a coil immobilization device; and
[0023] FIG. 8 is a diagram of an alternative embodiment of a coil immobilization device in accordance with the present invention in which Illustrations are shown for coils arranged in an “anterior/posterior” configuration, analogous coil arrays with coil elements to the “left” and “right” of the object are similarly considered.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring now to FIG. 1 , shown therein is a block diagram of an embodiment of a coil immobilization device in accordance with the present invention. FIG. 1 is a cross-sectional view of the body of a patient in the MRI bore of an MRI scanner. The MRI scanner includes excitation RF coils (not shown) for generating excitation magnetic fields that create changes in the magnetic spin moments of the atoms in the patient's body. The changes in the magnetic spin moments provides data that is recorded by the anterior and posterior imaging RF coil elements.
[0025] The anterior RF coil elements are statically held in place by the coil immobilization device. The posterior RF coil elements are integrated into a cushion (not shown) or the platform upon which the patient lies. The posterior RF coils cannot move regardless of whether the patient moves.
[0026] In current practice by those skilled in the art, the anterior RF coils are placed directly on the outer wall of the patient's body for imaging for improving the Signal-to-Noise ratio of the resulting MRI images. It was previously thought that such “FLEX” coils are best. However, in the case of parallel imaging, the use of FLEX coils, in part, generates ghost artifacts in the resulting MRI images when body parts that move, for whatever reason, are imaged.
[0027] The inventors have therefore devised the coil immobilization device which is used to separate the anterior and posterior RF imaging coil elements, such that normal or abnormal physiologic movement of the patient's (or healthy subject's) abdomen (or other body part) does not displace the imaging coil elements. As such, the necessary “parallel imaging sensitivity calibration scan” and the desired “parallel image with sensitivity encoding” can be acquired with the imaging coils in identical physical positions. Consequently, displacement-related reconstruction artifacts (see FIGS. 5-7 ), which typically manifest as shifted, interfering “ghost” images, will be minimized.
[0028] In the embodiment shown in FIG. 1 , an MRI system shown generally at 10 includes an MRI bore 12 into which a patient 14 is positioned on an MRI table 16 and an anterior RF coil array and a posterior RF imaging coil array. A coil immobilization device 18 comprises two distancing members 20 and 22 and a support member 24 upon which the anterior RF imaging coil array rests. The height of the distancing members 20 and 22 can be adjusted to accommodate patients 14 with different body cavity thickness. Alternatively, there may be several distancing members with various heights that can be attached to the support member. Further, the support member 24 may be arched as shown in FIG. 1 or can be straight. The coil immobilization device can be placed over the patient 14 before the patient is slid into the MRI bore.
[0029] Referring now to FIG. 2 , shown therein is a block diagram of an alternative embodiment of a coil immobilization device 30 in accordance with the present invention. The coil immobilization device 30 comprises two distancing members 20 and 22 and two support members 32 and 34 upon which the anterior RF imaging coil array rests. The height of the distancing members 20 and 22 can be adjusted to accommodate patients 14 with different body cavity thickness. Alternatively, there may be several distancing members with various heights that can be attached to the support members, Further, the support members 32 and 34 can be angled upwards as shown in FIG. 2 or they can project horizontally from the standing members 20 and 22 . The coil immobilization device 30 can be placed over the patient 14 before the patient is slid into the MRI bore 12 .
[0030] Referring now to FIG. 3 , shown therein is a block diagram of another alternative embodiment of a coil immobilization device 40 in accordance with the present invention. The coil immobilization device 40 comprises two bracket members 42 and 44 and a support member 46 upon which the anterior RF imaging coil array rests. The bracket members 42 and 44 are mounted on the inside surface of the MRI bore 12 . Only two bracket members are shown for simplicity. However, there are actually several bracket members on each inner portion of the MRI bore. Using one of the inner sides of the MRI bore as an example, the bracket members 42 and 44 are aligned vertically with respect to one another so that the support member can be mounted at several heights to accommodate patients 14 with different body cavity thickness. Accordingly, the bracket members 42 and 44 on either inner side of the MRI bore 12 that correspond to a particular height are horizontally aligned with respect to one another. Further, the support member 46 can be horizontal as shown in FIG. 2 or can have straight edges which slide within, or on top of, the bracket members 42 and 44 and an arched middle portion (not shown). The support member 46 of the coil immobilization device is slid or placed on (depending on the design of the brackets) a particular pair of brackets at a suitable height before the patient is slid into the MRI bore 12 .
[0031] Referring now to FIG. 4 , shown therein is a block diagram of another alternative embodiment of a coil immobilization device 60 in accordance with the present invention. The coil immobilization device 60 comprises two distancing members 62 and 64 that are suspended from the inner top portion of the MRI bore. The anterior RF imaging coil array is releasably mounted to the ends of the two distancing members 62 and 64 such that the RF imaging coil array is at rest. The length of the suspension members 62 and 64 can be varied to accommodate patients 14 with different body cavity thickness. The length of the distancing members 62 and 64 can be adjusted before the patient 14 is slid into the MRI bore 12 . The distancing members 62 and 64 do not necessarily have to be suspended from the same point on the inner top portion of the MRI bore 12 , nor do they have to be suspended from the topmost portion of the inner edge of the MRI bore 12 . The distancing members may be telescopic or there can be a variety of different distancing members, having different lengths, to accommodate patients 14 with different body sizes.
[0032] Accordingly, the distancing members can be removably suspended from the top inner portion of the MRI bore. A variation on this embodiment includes one distancing member with a support member that is used to immobilize the anterior RF imaging coils.
[0033] Referring now to FIG. 4 b , shown therein is a perspective view of another alternative embodiment of a coil immobilization device 70 . Device 70 includes an arcuate or arched support member 76 so that it is parallel to the curvature of the chest or abdomen so the RF multi-coil array, when secured on top of immobilization device 70 has “uniform sensitivity” to the body. The perspective view shown in FIG. 4 c shows an MRI system which has been retrofitted with the support members of FIG. 4 b with the patient lying on the MRI table. Device 70 includes ends 72 and 74 which are adapted to engage the sides of MRI table 16 so that they can slide along to the desired position. Only one support 70 is shown but in general several will be present to fully support the anterior RF multi-coil array. In general, the coil immobilization device can be a rigid or a semi-rigid device that is capable of immobilizing the anterior RF imaging coils. The coil immobilization device can be made of any non-ferromagnetic or non MRI-signal influencing material. Examples of such materials include, but are not limited to, plastics, polymers, wood and the like.
[0034] The vertical dimensions of the coil immobilization device are such that the device can fit within the bore of the MRI scanner (typically the bore has a 60 cm diameter). The vertical dimensions of the coil immobilization device are adjustable so that the RF imaging coils are placed as close as possible to the patient's body so that the motion of the patient's body does not displace the RF imaging coils while at the same time minimizing distance related signal to noise reduction in the resultant MR images. Accordingly, embodiments in which the support member is arched to match the outer curvature of the patient's body are preferable. In fact, the support member can be made of a semi-rigid material so that the curvature of the support member can be changed depending of the body wall curvature of the patient that is currently being imaged. In this regards, embodiments in which the RF imaging coils are immobilized at an angle that matches the body wall curvature of the patient are also preferable.
[0035] There can also be variations in the embodiments shown herein in which the RF imaging coils are mounted to the bottom of the support member. The support member in the various embodiments can also be modified such that there are indentations in which the RF imaging coils are placed. The indentations have a shape that accommodates the shape of the RF imaging coils.
[0036] FIG. 8 is a diagram of an alternative embodiment of a coil immobilization device in accordance with the present invention in which Illustrations are shown for coils arranged in an “anterior/posterior” configuration, analogous coil arrays with coil elements to the “left” and “right” of the object are similarly shown.
[0037] Referring now to FIG. 5 , shown therein are a series of panels of images illustrating a water phantom due to the effects of object displacement with and without a coil immobilization device. The water phantom included a container of water doped with copper sulphate solution to allow more rapid imaging (T1 shortening) which is common practice in phantom design. The upper two elements of a four-channel imaging coil array were displaced 1 cm between the calibration and image scans. The left topmost panel shows an image obtained with conventional MRI imaging methods. The remaining panels show images that were obtained with the ASSET image processing method. The top rightmost panel shows an MRI image obtained with a parallel factor of 2 without displacement of the test object. The parallel factor indicates the speed up factor in parallel imaging (this factor is usually 2 and cannot be more than the total number of imaging coils). The left bottommost panel shows an MRI image obtained with a parallel factor of 2 with displacement of the test object. There is a horizontal line artifact that is indicated by the arrow. The right bottommost panel shows an MRI image obtained with a parallel factor of 2, with a similar displacement of the test object and with the RF coils held in place by the coil immobilization device of the present invention. The artifact is no longer present.
[0038] Referring now to FIG. 6 , shown therein are a series of panels of images illustrating another water phantom due to the effects of object displacement with and without a coil immobilization device. The upper two elements of a four-channel imaging coil array were displaced several cm between the calibration and image scans. The left topmost panel shows an image obtained with conventional MRI imaging methods. The remaining panels show images that were obtained with the ASSET image processing method. The top rightmost panel shows an MRI image obtained with a parallel factor of 2 with displacement of the test object. The left bottommost panel shows an MRI image obtained with a parallel factor of 2.6 with displacement of the test object. The right bottommost panel shows an MRI image obtained with a parallel factor of 2.6, with a similar displacement of the test object and with the RF coils held in place by the coil immobilization device of the present invention. The artifact is no longer present.
[0039] Referring now to FIG. 7 is a diagram illustrating MRI images obtained on a healthy volunteer with and without a coil immobilization device. A four-channel imaging coil array was used. The left topmost panel shows an image obtained with the ASSET image processing method using a parallel factor of 2 without the coil immobilization device. The ghost images, indicated by the two arrows, result in image quality degradation. The top rightmost panel shows an MRI image obtained with the ASSET image processing method using a parallel factor of 2.6 without the coil immobilization device. Once again, there are significant ghost images, indicated by the arrows, which degrade image quality. The left bottommost panel shows an MRI image obtained with the ASSET image processing method using a parallel factor of 2 with the coil immobilization device. The right bottommost panel shows an MRI obtained with the ASSET image processing method using a parallel factor of 2.6 with the coil immobilization device. In both cases, the ghost artifacts are no longer present and the image quality is enhanced.
[0040] Accelerated MRI techniques increase in speed with increasing “parallel factor”. This is commercially implemented as a factor of 2, but in development can been as high as 4.0 or more. In general, as the community moves to higher (than 1.5T) magnetic field strengths, with more intrinsic MR signal, one can speculate that the use of higher than 2.0 parallel factors (SENSE factor, ASSET factor) will increase. As shown in FIGS. 6 and 7 , comparing ASSET factors of 2.0 and 2.6, obtained at 1.5T, the appearance of the ghost artifacts not only becomes more pronounced as the coil displacement increases, but also becomes more pronounced as the parallel factor is increased.
[0041] Advantageously, the coil immobilization device of the present invention can also reduce the ghost artifacts that occur when high parallel factors are used to generate the MRI images.
[0042] The device of the present invention can be used to immobilize imaging coil elements that may move due to a variety of reasons. Some examples include, but are not limited to: 1) endogenous movement (i.e. breathing which affects imaging of the abdomen, thorax, etc.), 2) necessary movement for kinematic studies (i.e. joint motion in the finger, wrist, shoulder, knee, ankle, etc.) and 3) external movement due to a consequence of external action (i.e. such as intervention or surgery of any body part).
[0043] Furthermore, the device of the present invention may be used for a variety of different magnetic resonance imaging methods. These methods include, but are not limited to, accelerated magnetic resonance imaging which comprises a family of parallel imaging techniques that use multiple imaging coils/receivers and sensitivity encoding, such as SENSE, SMASH, ASSET, iPAT, as a means of suppressing ghost artifacts in reconstructed images.
[0044] It should be understood that various modifications can be made, by those skilled in the art, to the preferred embodiments described and illustrated herein, without departing from the present invention.
[0045] As used herein, the terms “comprises”, “comprising”, “including” and “includes” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises”, “comprising”, “including” and “includes” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.
[0046] The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents. | The present invention provides several embodiments of a device for physically separating RF imaging coils from any source of movement thereby minimizing potential coil-displacement related reconstruction effect or artifact. The device can be used to enable parallel imaging of the abdomen, pelvis and other moving body parts such that normal or abnormal patient movement does not displace the coil elements between the calibration scan and the subsequent imaging scans. | 6 |
BACKGROUND OF THE PRESENT INVENTION
The present invention relates to load indicating members and load indicating fasteners and further relates to methods and apparatuses for making and using load indicating members and load indicating fastening members. More particularly, the present invention relates to a method of measuring a load in an ultrasonic load indicating member, a load measuring device using the method of measuring the load, a fastener tightening tool for tightening an ultrasonic load indicating fastener member using the method of measuring, an ultrasonic load indicating member and an ultrasonic load indicating fastener for use in conjunction with the method of measuring, a method of making the ultrasonic load indicating fastener, a method of tightening the ultrasonic load indicating fastener, and a transducer for instrumenting the load indicating member.
In many operations, it is desirable to determine the amount of longitudinal load experienced by a longitudinally stressed member. This information is particularly useful when the longitudinally stressed member is a fastener since the measurement of the longitudinal stress provides a verification of the existence of a proper joint.
Many prior techniques have been developed to indicate the amount of longitudinal stress experienced by a fastener providing a load indicating feature on the fastener itself. This is usually done by interconnecting one end of an elongated member, such as a pin, to a portion of the fastener prior to the installation of the fastener
An example of this type of load indicating member is depicted in FIG. 1 of the drawing. The elongated member 10 extends parallel to the fastener 12 and is unaffected by the elastic deformation of the fastener in response to longitudinal stress. The free end 14 of the elongated member 10 therefore provides a reference for indicating the elongation of the fastener 12 in response to the longitudinal stress. Typically, the elongated member 10 is a pin received within an elongated bore 16 disposed longitudinally of the fastener 12 and extended from the head 18 of the fastener and partially through the shank 20 of the fastener. One end 22 of the pin 10 is interconnected with the shank 20 of the fastener 12 at the base of the bore 16 by means, for example, of adhesives, threads, or an interference fit. The various prior load indicating members and load indicating fasteners of this type differed greatly in structure as well as in the methods and apparatuses with which they were used to provide an indication of the elongation of the load indicating member or fastener. Examples of this type of fastener are disclosed in U.S. Pat. Nos. 3,812,758 issued May 28, 1974 to Robert B. Bessler, Jr.; 3,823,639 issued July 16, 1974 to Theodore Liber; 2,503,141 issued Apr. 4, 1950 to Albert R. Stone; 3,943,819 issued Mar. 16, 1976 to Charles S. Charron; 2,600,029 issued June 10, 1952 to Albert R. Stone, 3,908,508 issued Sept. 30, 1975 to William J. Payne; 3,987,668 issued Oct. 26, 1976 to Charles H. Popenoe; and 4,144,428 issued Sept. 19, 1978 to Charles H. Popenoe; as well as in commonly assigned U.S. patent application Ser. No. 670,260 filed 11/13/84, now U.S. Pat. No. 4,676,109.
While each of the various pin-type load indicating members, and load measuring devices described above provides its own advantages in terms of accuracy, ease of manufacture, or ease of reading, they are still expensive to manufacture, since they each require extensive modifications and the addition of a centrally located pin-member to the load indicating member. As a result, such load indicating members are only selectively used in practice, either where there is a specific immediate diagnostic need or a serious recognized safety hazard involved. These members are simply too expensive for routine use in assemblies which may only occasionally benefit from such monitoring.
An alternate approach to measuring the elongation of a member or fastener is to use an ultrasonic measurement device. Typically, this is done, as shown in FIG. 2 of the drawing, by removably interconnecting an ultrasonic transducer 24 to one end of the member being measured, typically to the head 26 of a fastener 28. In order to obtain a reliable indication, the head of the bolt must be ground extremely flat and a reliable ultrasonic transmission media must be applied to the head of the bolt. The transducer must be properly positioned on the bolt and held in position while the measurements are being taken. Examples of techniques and apparatuses using this method are disclosed in U.S. Pat. Nos. 3,306,100 issued Feb. 28, 1967 to Wilheim et al.; 3,307,393 issued Mar. 7, 1967 to Kessler; 3,308,476 issued Mar. 7, 1967 to Kleesattel; 3,759,090 issued Sept. 18, 1973 to McFaul et al.; 3,812,709 issued May 28, 1974 to Benson et al.; 3,822,587 issued July 9, 1974 to Makino et al.; 4,0l4,208 issued Mar. 29, 1977 to Moore et al.; 4,062,227 issued Dec. 13, 1977 to Heyman; 4,117,731 issued Oct. 3, 1978 to Heyman; 4,363,242 issued Dec. 14, 1982 to Heyman; 4,402,222 issued Sept. 6, 1983 to Oson et al.; 4,413,518 issued Nov. 8, 1983 to Jones and 4,471,657 issued Sept. 18, 1984 to Voris et al.
The patents teach the notion of combining the measuring device with a tightening tool so that the information gained from measuring the elongation of the bolt can be used determining when to shut off the tightening tool or, alternatively, monitor the tightening process to determine whether a proper joint has been formed. Examples of such tightening tools are disclosed in U.S. Pat. Nos. 3,969,960 issued July 20, 1976 to Pagano, 3,969,810 issued July 20, 1976 to Pagano.
While the above listed methods and apparatuses can provide reliable information about a fastener and a joint, they are in very limited use. This is mainly because the bolt must be carefully manufactured and must be easily accessible to the instrumentation. Thus, ultrasonic tension measurement is recognized as a highly accurate laboratory tightening method for calibration application testing and for tightening very critical joints. It is replacing strain gage bolts in several calibration and critical quality control applications. However, the practical difficulties associated with taking ultrasonic tension measurements described above have prevented its application as a general assembly tightening strategy
Some attempts have been made to combine the advantages of the pin-type load indicating members, described previously, with the ultrasonic elongation measurement device described above by incorporating a piezoelectric or other ultrasonic sensor into the member itself. Examples of such members are disclosed, for example, in U.S. Pat. Nos. 4,127,788 issued Nov. 28, 1978 to Daugherty and 4,294,122 issued Oct. 13, 1981 to Couchman. Each of these disclosures provide an instrumented load bearing fastener which has been modified to incorporate a stress indicating feature. However, like the pin-type fasteners described previously, these instrumented fasteners are greatly modified in order to accept large and complicated ultrasonic sensing devices. They are therefore prohibitably expensive for wide spread use.
Examples of additional prior patents known to the applicant which teach or claim ultrasonic piezoelectric or alternate methods are:
______________________________________Patent No. Issue Date Inventor______________________________________3,201,977 8/24/65 Kutsay3,306,100 2/28/67 Wilhelm, Lyndhurst, Kliever3,307,393 3/7/67 Kessler3,308,476 3/7/67 Kleesattel3,541,844 11/24/70 Stover3,650,016 3/21/72 McMaster3,759,090 9/18/73 McFaul3,810,385 5/14/74 McFaul3,812,709 5/28/74 Benson3,822,587 7/9/74 Makino3,918,294 11/11/75 Makino3,924,444 12/9/75 Heyman3,930,405 1/6/76 Renken3,969,810 7/20/76 Pagano3,969,960 7/20/76 Pagano3,975,948 8/24/76 Makino4,014,208 3/29/77 Moore4,015,464 4/5/77 Miller4,062,227 12/13/77 Heyman4,117,731 10/3/78 Heyman4,121,467 10/24/78 Gerhart4,127,788 11/28/78 DaughertyRe. 30,183 1/8/80 Popenoe4,294,122 10/13/81 Couchman4,393,242 12/14/82 Heyman4,402,222 9/6/83 Olson4,413,518 11/8/83 Jones4,423,634 1/3/84 Audenard4,445,360 5/1/84 Treder4,471,657 9/18/84 Voris4,569,229 2/11/85 de Halleux4,567,766 2/4/86 Seiferling4,584,676 4/22/86 Newman4,601,207 7/22/86 Steblay4,602,511 7/29/86 Holt______________________________________
Very few actual products have resulted from these developments and their use has generally been limited t laboratory work and expensive and critical installations due to the difficulty in maintaining reliable coupling during tightening, the expense and complexity of the required equipment, and the strict control required over fastener materials and properties.
What is needed, therefore, is a low cost ultrasonic transducer permanently attached to a fastener in an inexpensive manner to provide accurate tightening information on a mass production basis. Such an ultrasonic load indicating member would permit easy interconnection with measuring or assembly tool devices and avoid the problems encountered with prior ultrasonic measuring devices in attempting to obtain a reliable acoustical coupling.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a load indicating member and a load indicating fastener, as well as methods and apparatuses for the use of the load indicating member and the load indicating fastener, which combine many of the advantages, heretofore only available separately in different load indicating members or fasteners, in a single member or fastener. The present invention further provides additional features and advantages not previously available in load indicating members, load indicating fasteners, load measuring devices, and tightening tools.
The load indicating member of the present invention includes a shank subjected to elastic deformation when stressed longitudinally, and first and a second generally flat surface, each formed adjacent to one longitudinal end of the shank, the first and second flat surface being coplanar and at approximately a preselected distance apart when the shank is unstressed. A piezoelectric element permanently, mechanically and electrically interconnected with first and second electrode means is disposed on the first flat surface of the shank. The first electrode means is permanently, mechanically, electrically and acoustically interconnected with the first flat surface. The first electrode means may, for example, consist of a conductive adhesive, a metallic film, or the member itself.
In a preferred embodiment, the piezoelectric element is a thin flexible piezoelectric disk, the first and second electrode means being metallic layers deposited on opposite faces of the disk. Furthermore, in this preferred embodiment, the load indicating member is a load indicating fastener having an enlarged head and the first flat surface is formed on the head of the fastener.
The method of making a load indicating fastener according to the present invention includes the steps of providing a flat surface at one longitudinal end of a fastener, disposing first and second electrode means on opposite faces of a flexible piezoelectric element; and permanently, mechanically, electrically and acoustically interconnecting the first electrode means with the flat surface of the fastener such as to electrically isolate the second electrode means from the surface.
The load measuring device according to the present invention provides a first contact means electrically engageable with the first electrode means, second contact means engageable with the second electrode means, and an electronic measurement device responsive to electronic differential signals between the first and second electrode means such as to provide a measurement of the tensile load of the load indicating member when stressed longitudinally.
In a preferred embodiment, the piezoelectric element may also provide a driving means for producing an ultrasonic signal such as to generate the electronic differential signals. Furthermore, in a preferred embodiment, the load indicating member is electrically conductive and the first contacts means is electrically engaged with the first electrode means indirectly by engagement of the first contact means with the load indicating member.
The tightening tool of the present invention includes first and second contact means electrically engageable, respectively, with the first and second electrode means, a load inducing means for imparting a tensile load in the load bearing member, and a load means for imparting a tensile load in the load bearing member, and a load measuring device responsive to the electrical differential signal such as to provide an accurate measurement of the tensile load.
In the preferred embodiment, the tightening tool of the present invention includes a electrically conductive fastener engagement means engageable with a load indicating fastener, a contact member engageable with a second electrode means of the load indicating fastener, a drive means imparting a torque on the fastener engagement means so as to rotatably drive the load indicating fastener, and a load measuring device responsive to the electrical differential signal received from the socket and the contact member such as to provide an accurate measurement of the tensile load of the shank of the fastener when stressed longitudinally as a result of the tightening process.
The output of the load measuring device may be used to provide a continuous reading of the instantaneous tensile load of the fastener or, alternatively, may be used to determine when the fastening operation is complete or to provide an indication of the load in a previously tightened fastener. When the load indicating member is a fastener, the load measuring device may be used simultaneously with a fastener tightening tool or, alternatively, may be incorporated directly into the fastener tightening tool. When the fastener tightening tool incorporating the load measuring device is of an automatic tightening type, the tensile load indication in the load measuring device may be combined with other parameters, monitored by the fastener tightening tool, such as angle and torque, to determine when the tightening cycle is complete and to detect irregularities in the joint.
The method of measuring the load in a load indicating member according to the present invention includes the steps of interconnecting a load measuring device of the present invention with a load indicating member of the present invention and calculating the tensile load of the shank of the load indicating member from ultrasonic measurements.
The method of tightening a load indicating fastener according to the present invention includes the steps of interconnecting a load measuring device according to the present invention to the head of a load indicating fastener according to the present invention, tightening the load indicating fastener while continuously monitoring the load measuring device to determine when a preselected load is reached, and ceasing the tightening of the load indicating fastener when the preselected load is reached, as indicated by the load measuring device.
A primary object of the present invention is to provide an inexpensive load indicating member or fastener which may be easily installed with conventional tools. Another object of the present invention is to provide an inexpensive and accurate method of measuring the load in the load indicating member or a load indicating fastener, a load indicating device and a fastener driving tool using the method of measuring of the present invention, a load indicating member for use in conjunction with the method of measuring of the present invention, a method of making the load indicating member of the present invention, and a method of tightening the load indicating fastener of the present invention.
Another object of the present invention is to provide an inexpensive method of making a reliable, accurate and compact load indicating member or fastener from a conventional member or fastener.
Another object of the present invention is to provide a transducer having improved performance including a higher signal to noise ratio than prior designed.
Yet another object of the present invention is to provide a method and an apparatus for reliably and removably coupling a load measuring device with a load indicating member or fastener and for repeatedly or continuously monitoring the load indicating member or fastener
Still another object of the present invention is to provide a method, tool, and load indicating member providing a means for monitoring the quality of the member by detecting imperfections in the member and further inspecting members which were stressed at an earlier time to determine the current condition, and particularly, to determine if prestressed fasteners have loosened
Yet another object of the present invention is to provide a load indicating fastener which may be tightened by conventional tightening tools and, more particularly, to provide a load indicating fastener which may be monitored by a load measuring device during a tightening operation.
Still another object of the present invention is to provide a method for providing a continuous indication of the load in a load indicating fastener during a tightening operation or during use of the device to which the fastener is attached.
Still yet another object of the present invention is to provide a fastener tightening device for use in conjunction with a load indicating fastener, which fastener device provides an automatic fastening operation responsive to a measurement of a tensile load responsive characteristic such as the shank of the load indicating fastener, during the tightening operation.
These and any other objects, features, and advantages of the present invention will become apparent to those skilled in the art when the following exemplary detailed description of the present invention is read in conjunction with the drawings appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like reference numerals refer to the like elements throughout:
FIG. 1 is a partially cut-away side view of the load indicating member of the prior art;
FIG. 2. is a partially cut-away side view of an ultrasonic load measuring device of the prior art;
FIG. 3 is a perspective view depicting an example of a load indicating member according to the present invention;
FIG. 4 is an enlarged and partially sectional view illustrating the indicating fastener of FIG. 1;
FIGS. 4a through 4c are partial views similar to FIG. 4 but illustrating alternate examples of load indicating members according to the present invention;
FIG. 5 is a partially schematic and partially cut-away side view depicting a load indicating fastener according to the present invention as well as a fastener tightening tool engaged therewith, the fastener tightening tool incorporating a load measuring device according to the present invention; and
FIGS. 6 through 10 are graphical views illustrating the acoustical operation of the present invention in its various embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and more particularly to FIGS. 3 and 4 thereof, a first example of a load indicating member, and more particularly, a load indicating fastener 110 is illustrated. The load indicating fastener 110 is formed from a conventional bolt which has been modified to provide an indication of the tensile load, stress, elongation or other characteristics of the bolt during a tightening operation as well as at various other times during the life of a joint. The bolt has a shank 112 with threads 114 formed at one end and with a head 116 formed at the other end. A shoulder 118 is formed between the head 116 and the shank 112. The head 116 has a generally flat upper surface 120 disposed normal to the longitudinal axis 122 of the shank 112. A lower surface 124 is formed at the opposite end of the shank 112 and is also disposed normal to the longitudinal axis 122. The head is also provided with a wrenching or tool engagement surface 126, such as a hexagonal wrenching surface, disposed about the periphery thereof.
Alternatively, as shown in FIG. 4b a flat surface 120a may be formed in a recess 121 in a head ll6a. The recess 121 may be a tool engagement socket or a lightening hole or a shallow recess created for the purpose of protecting the piezoelectric sensor 128 from environmental hazards.
The piezoelectric ultrasonic sensor 128 is permanently or semi-permanently mounted to the upper surface 120 or l20a of the head 116. As illustrated in the drawing, the piezoelectric sensor preferably consists of a disk 130 of piezoelectric material having a first and second electrode 132 and 134, respectively, applied to each of its opposite flat surfaces.
Preferably, the piezoelectric disk is formed of a flexible inexpensive piezoelectric material, such as a polymeric material. In the preferred embodiment polyvinylidene fluoride is chosen since it is very resistance to corrosive substances. However, other materials may exist or be developed having satisfactory properties and laminated bimorphs and multimorphs are contemplated as alternatives. The electrodes may be formed of metallic layers vacuumed deposited on the piezoelectric disk, a conductive ink or paint, or a conductive adhesive. Alternatively, one or both may be a conductive foil permanently bonded to the disk. The first electrode is electrically and acoustically coupled to the head 116 while the piezoelectric disk 130 and the second electrode 134 are electrically isolated from the head 116. For some embodiments, the head 116 will perform the function of the first electrode 132.
For some installations, the first electrode 132 may consist of a conductive adhesive. Alternatively the adhesive may be non-conductive and rely on capacitive coupling for the electrical communication between the first electrode 132 and the head 116.
In experimental work, the echo signal levels of a thin film polymeric piezoelectric transducer adhesively coupled with a member was compared with prior art thick ceramic transducers removably mechanically coupled with a member. While signal levels were comparable, the signal to noise ratio was considerably higher with the film transducer, thus demonstrating a greater ease and reliability of echo detection.
The higher noise levels of the ceramic transducer may be attributable to echoes resulting from ultrasonic waves reflected internally within the transducer and transducer housing. Reflected acoustic waves within the film transducer may decay more quickly since the lower acoustic impedance of polymeric piezoelectric films such as polyvinylidene fluoride permit more efficient transfer of energy to the air or conductive rubber contact.
It should be noted that the use of the piezoelectric film transducer therefore is a significant transducer performance improvement over the prior art.
Referring to FIG. 5, an example of a load indicating fastener 110 described above is shown with a fastener tightening tool 140 according to the present invention engaged therewith. The fastener tightening tool 140 includes a conventional power tool 142, only the housing of which is shown in the drawing. The conventional power tool 142 has a rotary output driver 144 engageable with a socket member 146. The socket member 146 engages the head 116 of the fastener 110 both electrically and mechanically.
A contact pin 148 is reciprocally mounted to the fastener tightening tool 140 to reciprocate relative to the socket member 146 into engagement with the second electrode 134 of the piezoelectric sensor 128 and the head 116 of the fastener 110. The contact pin 148 is preferably provided with a conductive rubber tip l48a such as to provide a low acoustic impedance interface while refraining from damaging the transducer.
An electronic control device 150, shown only schematically in the drawing, is electrically interconnected with the contact pin 148 and the socket member 146 by means of electrical lines 152 and 154, respectively, by way of slip ring wipers 156 and 158, as is well-known in the art. Alternatively, the signal may be transferred by a non-contact means, such as by capacitive coupling, and other techniques well-known in the art. The electronic control device 150 supplies and measures electronic differential signals between the first and second electrodes 132 and 134 of the piezoelectric sensor 128 such as to provide an ultrasonic measurement of the tensile load, stress or elongation of the shank 112 of the fastener 110.
It will be appreciated by those skilled in the art that the fastener tightening tool 140 may be provided with a display device, not shown in the drawing, for displaying ultrasonic measurement of the tensile load, stress or elongation obtained during the fastener operation. Alternately, the fastener tightening tool 140 may be adapted to use the information continuously supplied by the electronic control device to determine when a predetermined amount of tensile load or elongation has occurred and therefore when a tightening operation should be stopped.
It will further be appreciated by those skilled in the art that the power tool chosen may, in a manner well-known in the art, monitor other characteristics of the joint being formed, such as the torque and the instantaneous angle of the load indicating fastener. An example of such a power tool may be found in the U.S. Pat. No. 4,344,216 issued Aug. 17, 1982 to Robert J. Finkleston. This other information available from the power tool may be combined with the tensile load, stress or elongation information supplied by electronic control device 150 to provide a precisely controlled tightening operation wherein the various measured parameters are used directly to control the tightening sequence or to monitor the results of the tightening operation. For example the socket member 146 may be used in conjunction with the power tool using what is known in the art as a "turn of the nut tightening sequence" while the elongation information is used subsequently to determine whether the joint formed by the tightening sequence meets certain specifications.
In use, the load indicating fastener 110 for the present invention may be used to secure panels 136 and 138 together by being passed progressively through suitable bores therein and being fastened therebehind by a nut 139. The fastener tightening tool 140 or, if desired, any standard tightening tool, engages the tool engagement surface 126 of the load indicating fastener 110 and is rotated to tighten to joint. As the panels 136 and 138 engage, respectively, the shoulder 118 and the nut 139, the shank 112 of the load indicating fastener 110 experiences longitudinal stress causing longitudinal elastic deformation of the shank 112. The amount of tensile load, stress or elongation of the shank 112 can be measured by the fastener tightening tool 140.
While FIG. 5 illustrates a fastener tightening tool 140 incorporating a convention power tool 142 and electronic control device 150, it will be appreciated by those skilled in the art that a fastener measuring tool may be made incorporating all the components of the fastener tightening tool 140 except the power tool 142. Such a device may be used to measure the elongation of a bolt independently of the tightening tool.
It should be further noted that the design of the load indicating fastener 110 described above facilitates rapid modification of existing bolts. No special surface treatment is required except the provision of a generally flat upper surface 120. In practice, it was found to be desirable with prior art methods to have a surface finish on the order of 125 micro inches while 250 micro inches has been determined to be acceptable for the purpose of acoustical coupling. However, for the present invention, a surface finish of substantially more than 250 micro inches has been found to be acceptable because of the use of an adhesive coupling A piezoelectric sensor 128 may be formed independently of the bolt by applying a film of metallic material to each of opposite faces of a piezoelectric disk 130. A suitable adhesive for acoustically and mechanically coupling the piezoelectric sensor 128 to the upper surface 120 of the head 116 may be applied to the piezoelectric sensor in advance together with a peel-off sheet of inert material, not shown in the drawing but well-known in the art for storing the piezoelectric sensor until the time for installing the sensor on the fastener 110.
The apparatus of the present invention permits a direct measurement of the time of flight of ultrasonic waves along the axial length of the member. The time of flight will vary with the length of the bolt and with the stress in the bolt.
Many different electronic techniques for the measurement of time of flight are well-known in the art as a result of ultrasonic developments in the field of non-destructive testing. Most are capable of providing the required resolution and accuracy. However some offer advantages in terms of the number of pulses for accurate measurement, circuit complexity and power consumption.
A significant factor is that the affect of axial stress on the speed of transverse ultrasonic waves is much less than that of longitudinal waves. Therefore, measurement of the time of flight of both waves can be used to determine axial stress without knowledge of the length of the bolt. This therefore allows measurement of the axial load in pre-installed fasteners A brief comparison of the information available from using transverse and longitudinal waves is provided below.
All ultrasonic equipment currently available uses the measurement of the time of flight of a longitudinal ultrasonic wave generated with a piezoelectric transducer mounted on one end of the bolt (usually the head). The ultrasonic wave travels to the opposite end where it is reflected back and detected by the same transducer. The numerous approaches to measuring this time of flight are briefly described below, but all produce a measurement of the change in time from the zero tension condition from which the tension is the calculated
It is common practice to grind the ends of the fastener parallel and to a surface finish of better than 250 micro inches. A good surface finish is a requirement for adequate acoustic coupling to the bolt.
The ultrasonic wave used for this time of flight measurement may be a longitudinal wave. The particle motion in a longitudinal wave is in the direction of propagation forming moving zones of compression and tension. The time of flight of a longitudinal wave is dependent on the length of the bolt and the speed of the ultrasonic wave. The variations in the length of the bolt result from thermal expansion, elongation due to axial load as a result of tightening, and plastic deformation if tightened to yield. The speed of the ultrasonic wave is dependent on the properties of the material, that is, the composition, heat treat, and temperature, for example, and the axial stress in the fastener induced by tightening. Parameters associated with material properties and their variations with temperature are determined experimentally and normally entered into the ultrasonic tension measurement equipment along with an ambient temperature measurement.
As the fastener is tightened, the bolt extends under axial load and the speed of propagation of the ultrasonic wave is reduced due to the axial stress. The latter accounts for approximately two-thirds of the increase in the measured time of flight.
Grip length, or a preselected relevant compensating stress factor, must also be entered as a parameter when measuring tension with this technique since it affects not only the bolt elongation under load but also the average stress and hence the average speed of propagation over the length of the bolt.
There are therefore several limiting characteristics of using the time of flight of longitudinal waves over the entire length of the fastener. The measurements are dependent on grip length which must be entered as a control parameter. Additionally, variations in local stress distributions in the region of the nut affect accuracy. It is not practical to measure the tension in the fastener after it is installed unless bolts are all ground to an exact length, typically to plus or minus one ten thousandth of an inch, or the exact length is measured and entered into the measurement system as a parameter. Tension measurements are normally based on the increase in the time of flight relative to the zero load measurement made prior to commencement of tightening.
Longitudinal waves are the more commonly known sound waves in that they are the waves which are used to transmit the oscillations of a source of acoustic energy through the air to the ear. In contrast, the particles of a transverse wave do not oscillate in the direction of propagation but at right angles to it. This wave is sometimes referred to as a shear wave since adjacent particles are subject to shear forces. Since gases and liquids are generally incapable of transmitting transverse waves, a special high viscosity coupling fluid is required by prior art equipment to acoustically couple from a transducer temporarily attached to the bolt.
A longitudinal wave travels almost twice as fast as a transverse wave in steel and the time of flight is affected to a different degree by axial stress. The variation in speed of the transverse wave in response to stress is about one and one half orders of magnitude less than that of the longitudinal wave.
As described in the patent to Holt, cited in the background, longitudinal and transverse waves may be applied to one end of the fastener by a piezoelectric crystal producing a wave having both longitudinal and transverse components. The time of flight of each of the longitudinal and transverse waves is measured. The tensile stress can then be determined from these two measurements without prior knowledge of the exact length of the bolt.
The use of both longitudinal and transverse waves provides, in theory, two significant advantages over the use of the longitudinal wave only. First, tensile load measurements can be made without first making zero load measurement i.e. load can be measured in already installed fasteners. Second, the effect of bolt to bolt variations from material properties, heat treatment etc, is reduced since they affect both longitudinal and transverse waves.
The apparatus of the present invention may be used with either or both of these waves, as contemplated by the inventor.
It is further contemplated by the inventor that the apparatus of the present invention may be used with any of the various timing techniques, including direct timing, indirect timing, clock interpolation, double pulsing, resonant frequency detection, acoustic impedance detection, harmonic frequency detection, and phase detection, as briefly described below.
The direct timing technique involves measurement of the time interval from the transmission of the drive pulse to the receiving of the echo signal with a gated oscillator and counter as shown in FIG. 6. For example, one commercially available instrument sold by Raymond Engineering uses a 100 MHz clock and averages 160 measurements to achieve the required resolution. Clock rates as high as 2 GHz are now possible with Gallium Arsenide technology.
The indirect timing techniques involves timing from the first echo to the second echo as shown in FIG. 7. Measurement of the time interval between the first and second echoes eliminates errors due to trigger point variations with difference echo waveform shapes and circuit and wiring time delays. Bolt end finish is more critical since the second echo is attenuated at each of the three reflections.
In the clock interpolation method resolution is improved by using analog techniques to determine a fraction of a clock cycle in addition to the clock count. One approach illustrated in FIG. 8, uses two synchronized out of phase clocks which are each integrated over the same short period at the end of the gating interval.
In the double pulsing technique, two pulses A and B are transmitted, as depicted in FIG. 9. Pulse A produces first echo A1 and second echo A2, and pulse B produces first echo B1 and second echo B2. The time interval between the paired pulses A and B is adjusted so that the second echo from A, i.e. A2. coincides with the first echo from pulse B, i.e. B1. The result is rectified and integrated to produce a frequency control voltage for a voltage controlled oscillator which adjusts the pulse timing. The frequency of the voltage controlled oscillator is used to calculate tension.
In the fundamental frequency detection technique, the bolt is maintained in longitudinal wave resonance at its fundamental frequency and the difference in its value before and after tightening used to determine the tension.
In the acoustic impedance detection technique the bolt is driven near its fundamental frequency and the change in mechanical or acoustic impedance used to determine tension.
The harmonic resonance frequency detection technique is a variation of the resonant method in which a harmonic longitudinal wave resonance is maintained at a harmonic frequency in for example, the 5-10 MHz range. Bolt tension is calculated from frequency shift during tightening.
The phase detection technique uses a pulsed phase locked loop approach. The radio frequency output of a voltage controlled oscillator is periodically gated to the transducer. The received signal produced by the reflected wave is mixed with the output of the voltage controlled oscillator as shown in FIG. 10. If the oscillator and the received signal are in phase, the summed signal will be a maximum, if one hundred and eighty degrees out of phase, the two signals will cancel, forming a minimum. This summed signal, therefore represents the difference in phase and is used to control the frequency of the voltage controlled oscillator so that the phase remains constant, that is, the summed signal is a minimum or maximum. In this way, the frequency of the oscillator is adjusted so that the time of flight is maintained at an exact number of cycles. The time of flight is determined from the frequency and the number of cycles counted between the start of transmitting to the start of receiving.
It will be appreciated that the above described techniques and the two types of waves may be used in various combinations to measure one or more parameters to the desired accuracy.
It should be appreciated by those skilled in the art that the load indicating fastener 110 of the present invention facilitates the rapid interconnection of a conventional fastening tool or an instrumented fastening tool such as the fastening tool 140. Both the fastener 110 and the fastener tightening tool 140 are comparably inexpensive to manufacture use. The present invention therefore would facilitate more widespread use of ultrasonic fastening and monitoring techniques in production.
The fastener 110 and the fastener tightening tool 140 facilitate rapid formation of reliable joints having repeatable and predictable characteristics. They permit a means to detect flaws in the joint during actual installation process thus reducing the risk of catastrophic joint failure. They further permit the monitoring, at a later time, of the characteristics of the joint.
It should be noted that the fastener, method, and tool of the present invention provide an inspection feature for monitoring the condition of the load indicating member. If the approximate length of the member is known, the approximate time of flight of an ultrasonic pulse is also known. If the measured result does not agree, or if the signal is in others unlike the expected signal, there may be imperfections, such as cracks, in the member. It should also be noted that the sensor 128 can be used on either end of any bolt or threaded rod and the tool can be used in engagement with other head engagement means or with a nut engagement means.
The above detailed description includes the best mode contemplated by the inventor at the time of filing of the present application for carrying out the present invention. It will be appreciated by those skilled in the art that many modifications may be made to the load indicating fastener, the load measurement device, and the fastener tightening apparatus described above without departing from the spirit of the present invention. Such modifications are included within the intended scope of the claims appended hereto. | A method of measuring the load in a member subjected to longitudinal stress, a load measuring device and a fastener tightening device using the method of measuring, a load indicating member and a load indicating fastener for use in conjunction with the method of measuring, a method of making the load indicating fastener, a method of making the load indicating fastener, a method of tightening the load indicating fastener and a transducer for instrumenting a load bearing member are each disclosed and claimed. A thin piezoelectric sensor consisting of a piezoelectric film sandwiched between two thin electrodes is permanently mechanically and acoustically coupled to the upper surface of a member and is used to determine the length, tensile load, stress, or other tensile load dependant characteristic of the member by ultrasonic techniques. | 6 |
BACKGROUND OF THE INVENTION
In a gate restraining mechanism in a hydraulic turbine, the bolt must be prestressed so as to provide the necessary force to effect adequate clamping of the shear lever on a hub. In the past it has been the practice to provide an axial opening through the bolt and insert an electrical heater therein to elongate the bolt. After the bolt had been elongated, the end nuts were snugged up and the bolt was allowed to cool. This method is time consuming; and, also, by drilling the axial opening in the bolt to accommodate the electrical heater, the bolt was weakened. The electrical heating method was also hazardous to the personnel working around the hot parts.
It is the general purpose of this invention to provide a prestressing device which operates solely on the piece to be prestressed of a mechanical arrangement without reacting on any other component of the arrangement.
Another object of the present invention is to provide a prestressing device which is removable after prestressing has been accomplished.
The present invention includes a relatively long bolt which is provided for prestressing in lieu of the normal length clamp bolt. The threaded ends of the bolt receive the normal clamping nut, and the extreme ends of the bolt receive end nuts. Two levers are attached to the ends of the end nuts by means of removable pins. A hydraulic cylinder and piston mechanism is connected to act upon the other ends of the levers. A fulcrum bar connected between the ends of the levers acts as a fulcrum for the levers. As the hydraulic cylinder and piston pulls on the levers, the force is transmitted to the bolt which is elongated. The clamping nuts are snugged up and the pressure in the cylinder released. Thereafter the pins are removed releasing the device from the bolt and the attaching ends nuts removed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary plan view of a portion of a wicket gate assembly with operators for the several wicket gates in which the present invention is incorporated; and,
FIG. 2 is an enlarged view of the prestressing device of the present invention connected to an operator clamp bolt for prestressing the same.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1 a hydraulic turbine includes a plurality of wicket gates 11 which are circumferentially spaced for pivotal movement between open and closed positions on an annular head cover 12. The wicket gates are operated simultaneously by a gate operating ring 14. To this purpose each of the wicket gates is operatively connected to the gate operating ring 14 by operating linkages. The operating linkages for each wicket is identical; thus, like parts will be identified by the same reference numerals.
As shown, the wicket gate 11 is provided with a shaft 16 on which is mounted a hub 17 of a strain link 18. A drive connection is established between the wicket gate shaft 16 and the hub 17 by means of a key 19. An operating lever arm 21 is mounted on the hub 17 of the strain link 18 and is connected to the strain link 18 by means of a strain pin 22. At one end the operating lever 21 is pivotally connected to one end of a drive link 23. The opposite end of the drive link 23 is pivotally connected to the gate operating ring 14.
With the single gate operating ring 14 connected to move all of the wicket gates 11 between open and closed positions simultaneously, the gates and their associated operating levers must be adjusted individually to establish a closed position for each gate with respect to adjacent gates. Also the position of the associated operating lever with respect to the wicket gate and its connection with gate operating ring 14 must be established. To this purpose the end of the operating lever 21 that is connected around the hub 17 by the strain lever 18 is split so as to present two resilient arms 26 and 27 that are spaced from each other by a gap or space 28. A threaded bolt 31 is inserted through bores 32 and 33 formed in bosses that are integral with the arms 26 and 27. Nuts 34 and 36 are engaged on the extending ends of the bolt 31 and snugged up to clamp the operating lever 21 to the hub 17.
However, the frictional engagement of the lever 21 on the hub 17 of the strain link 18 must be substantially equal to the shear force which will shear the pin 22. This ratio of forces is necessary so that damage to the wicket gate will not occur should the gate be blocked from moving by foreign substances lodging in the gate opening. In this case the pin 22 will shear and the operating lever 21 must slip around the hub 17. However, it is not possible to snug up the nuts 34 and 36 to provide the necessary frictional engagement of the bifurcated end of the operating lever 21 on the hub 17 with wrenches alone. Also, in a powerhouse there is not always sufficient space to apply power apparatus to the nuts 34 and 36 when it is necessary to readjust the gates. It is, therefore, necessary to prestress the bolt 31 so that the nuts 34 and 36 can be snugged up with hand tools to provide the desired clamping force.
To this purpose, as shown in FIG. 2, there is provided a hydraulic actuated prestressing means 40 which is releasably attachable to the bolt 31 for prestressing the same. The prestressing means 40 acts solely on the bolt 31 and not on any other component of the wicket gates or the associated operators. The prestressing means 40 includes a pair of stressing nuts 41 and 42. The nuts 41 and 42 are cylindrical in form and are threaded on each end of the bolt 31 outwardly of the clamp nuts 34 and 36. A pair of levers 43 and 44 are removably and pivotally attached to the stressing nuts 41 and 42 by means of pins 46 and 47. A hydraulic cylinder 51 is connected to the opposite end of the lever 43 by a pin 52 that extends through a suitable bracket 53 welded or otherwise secured to the end of the cylinder. Within the cylinder 51 is a reciprocal piston 54 having a piston rod 56 which extends outwardly of the cylinder 51. The free end of the piston rod 56 is provided with a threaded fitting 57 and is connected to the end of the lever 44 by a removable pin 58. A fulcrum bar 61 is connected by pins 62 and 63 to the levers 43 and 44 and is located so as to provide substantially 2-to-1 mechanical advantage.
In operation hydraulic pressure is admitted to the cylinder 51 at the rod side of piston 54. The fluid pressure acting on the piston 54 on the rod side thereof will cause the connected ends of the levers 43 and 44 to be pulled inwardly toward each other. The fulcrum bar 61 provides a fulcrum for the levers and the levers transfer the force to the ends of the bolt 31 to elongate the bolt. With the bolt 31 in a prestressed condition, the clamp nuts 34 and 36 are snugged up and the pressure in the cylinder released.
It is apparent that the present invention by utilizing opposing levers and a fulcrum does not react on any other component of the gate apparatus other than the clamp bolt with which it is directly concerned. The present invention does not weaken the bolt and does not present hazards to personnel. The device can be utilized where the clearance beyond the ends of the bolt is limited. | A hydraulic cylinder and piston mechanism which acts on opposing levers with a fulcrum bar interposed to prestress a shear lever bolt of a gate restraining mechanism of a hydraulic turbine without reacting on any other component. | 8 |
FIELD OF APPLICATION
[0001] In its most general aspect, the present invention relates to a process for the separation and recovery of carbon dioxide from waste gas or fumes produced by combustible oxidation.
[0002] In particular, the present invention relates to a process for the separation and recovery of carbon dioxide from exhaust gases or fumes produced by the oxidation of fossil fuels or fractions and derivatives thereof with air.
[0003] The term “oxidation” is meant to comprise both the normal combustion of fuels, particularly fossil fuels, with air, carried out on a domestic or industrial scale, and the electrochemical oxidation thereof, occurring, for example, in the fuel cells.
PRIOR ART
[0004] It is well known that exhaust (waste) gases or fumes produced by the combustion or by other oxidative processes of fossil fuels (combustible) in industrial or domestic plants, are dispersed in the atmosphere causing various environmental impact problems. The most severe of such problems relates to the overall heating of the planet, known as “greenhouse effect” for which the carbon dioxide contained in said exhaust gases or fumes is responsible.
[0005] Furthermore, it is known that carbon dioxide is a feed raw material in several industrial processes; for carrying out such processes, the thermal energy produced by the combustion of fossil fuels is usually employed. For these processes, therefore, it could be convenient to separate and recover at least part of the carbon dioxide from the combustion exhaust gases, in order to increase the production capacity and/or to reduce the purchasing costs of this raw material.
[0006] For example, in the processes for the production of ammonia and urea or methanol, it is known that the feed raw materials such as hydrogen, carbon monoxide and carbon dioxide are generally obtained in the form of a gaseous mixture through the reforming of methane or other light hydrocarbons such as natural gas, LPG (liquefied petroleum gas), naphtha.
[0007] The methane conversion is carried out in a dedicated furnace of a reforming plant, usually associated to the that used for the production of ammonia and urea or methanol, exploiting the thermal energy produced by the combustion of a part of the feed methane with air.
[0008] Within the production process of ammonia and urea, nitrogen is then added in stoichiometric amount to the gaseous mixture obtained through the reforming, in order to convert hydrogen into ammonia.
[0009] However, in this way, the amount of carbon dioxide contained in the aforesaid gaseous mixture is smaller than the stoichiometric amount required to convert into urea all the ammonia produced, so that the urea production plant capacity is disadvantageously reduced.
[0010] Instead, in the methanol production process, it is the hydrogen of the gaseous mixture obtained through the reforming that is in excess with respect to the amount necessary for converting all the carbon monoxide and carbon dioxide into methanol and therefore part of it is purged from the synthesis reactor and often used as fuel.
[0011] In the above mentioned two processes, hence, it is clear that the production capacity of urea and methanol, respectively, could be significantly increased, should it be possible to recover even only part of the carbon dioxide contained in the combustion gases of the methane reforming plant.
[0012] Therefore, the problem regarding the separation and recovery of carbon dioxide from the combustion gases or fumes is quite felt and in the last decades has been the subject of several studies.
[0013] The larger part of these studies was directed to the so-called “wet” separation and recovery processes of carbon dioxide. That is to say, processes based upon the scrubbing of the combustion gases with suitable solutions or solvents able to adsorb selectively carbon dioxide and the recovery of the adsorbed carbon dioxide through heating of the adsorbing solution or solvent.
[0014] Various processes of the aforesaid type have been developed in the prior art; however, they suffer of various drawbacks that limit their industrial applicability.
[0015] One of the drawbacks, which are more often encountered lies in the fact that the scrubbing solution is subjected to oxidation phenomena of its components, which phenomena are due to the presence of oxygen in the combustion gases, and therefore requires a frequent replacement.
[0016] Furthermore, it shall be noted that the combustion gases usually contain also sulphur and nitric oxides (SOx and NOx), that react with some components of the scrubbing solution, creating stable salts and other harmful compounds of difficult removal and disposal.
[0017] Hence, the need of frequently replacing the scrubbing solution as well the removal and disposal of the harmful compounds deriving from its degradation imply relevant operating costs for the aforesaid known processes of gaseous carbon dioxide separation and recovery.
[0018] Furthermore, the equipment required for implementing the carbon dioxide separation and recovery processes of the prior art are complicated, expensive, difficult to be operated and have a large size, and therefore high investment and maintenance costs are also implied.
[0019] The technical problem underlying the present invention is that of providing a process for the separation and recovery of carbon dioxide from waste gases produced by combustible oxidation that is simple and cost-effective to be carried out, and does not exhibit the previously described drawbacks with reference to the carbon dioxide separation and recovery processes of the prior art.
SUMMARY OF THE INVENTION
[0020] This technical problem is solved by a process for the separation and recovery of carbon dioxide from waste gases produced by combustible oxidation comprising the steps of:
[0021] feeding a flow of waste gas to a gas semipermeable material,
[0022] separating a gaseous flow comprising high concentrated carbon dioxide from said flow of waste gas through said gas semipermeable material, and
[0023] employing at least a portion of said gaseous flow comprising high concentrated carbon dioxide as feed raw material in an industrial production plant and/or stockpiling at least a portion of said gaseous flow comprising carbon dioxide.
[0024] The gas semipermeable material can be chosen from the group comprising hollow fibre membranes and materials able to adsorb preferentially carbon dioxide, such as the molecular sieves.
[0025] The hollow fibre membranes can be of the type preferentially permeable to carbon dioxide or of the type substantially non-permeable to this gas.
[0026] The term “molecular sieves” is meant to comprise all those conventional materials having micropores adapted to adsorb preferentially the carbon dioxide contained in a gaseous mixture, including activated carbon. According to the specific way the carbon dioxide is adsorbed and released, these materials are classified as molecular sieves or activated carbons of the PSA (pressure swing adsorption) or TSA (temperature swing adsorption) type.
[0027] In the PSA adsorption process, the gas mixture containing carbon dioxide is made pass through the molecular sieve under pressure in such a way to promote the preferential adsorption of carbon dioxide in the micropores. Then, the pressure is reduced in such a way as to obtain a desorption of the carbon dioxide together with other gaseous components possibly retained therewith and accordingly regenerate the molecular sieve.
[0028] Differently, in the TSA method, the preferential adsorption of carbon dioxide into the micropores is carried out by letting the gaseous mixture containing carbon dioxide to be separated, pass through the above mentioned molecular sieve, at a temperature not higher than 80° C. Then the temperature is increased, for example with the aid of a vapour flow, in such a way as to obtain a desorption of the carbon dioxide together with other gaseous components possibly retained therewith and accordingly regenerate the molecular sieve.
[0029] Preferably, in the process according to the present invention at least a molecular sieve of the TSA type is used.
[0030] The use of molecular sieves of the TSA type in the process according to the invention does not require the compression of large amounts of gas to be separated and therefore is advantageous because of the resulting low energy costs.
[0031] Furthermore, in order to regenerate the molecular sieves of TPA type, it is enough to let a vapour flow or, alternatively, a portion of the gas flow comprising high concentrated carbon dioxide, pass through these sieves, wherein such portion of gas flow is suitably heated at the regeneration temperature of such sieves.
[0032] Otherwise, the use of hollow fibre membrane or molecular sieves of PSA type in the process according to the invention is less advantageous, if compared with the use of molecular sieves of TSA type, because of the relevant energy costs connected to the required compression of the exhaust gases to be treated.
[0033] Further on, the hollow fibre membranes are very expensive even if they guarantee a greater effectiveness and separation yield of the carbon dioxide from other gaseous components contained in the combustion exhaust gases.
[0034] According to a preferred embodiment of the present invention, the gas semipermeable material is able to adsorb preferentially carbon dioxide and the separation of the gaseous flow comprising high concentrated carbon dioxide from said waste gas flow comprises the steps of:
[0035] letting a waste gas flow permeate into said gas semipermeable material in such a way as to adsorb at least a relevant portion of the carbon dioxide contained in said waste gas flow and obtain a permeated gas flow with a low carbon dioxide content,
[0036] dispersing said permeated gas flow with low carbon dioxide content, and
[0037] deabsorbing said at least one relevant portion of carbon dioxide from said gas semipermeable material, thus obtaining said gaseous flow comprising high concentrates of carbon dioxide.
[0038] The features and advantages of the process for the recovery of carbon dioxide from combustion exhaust gases according to the present invention will become clearer from the following description of an indicative and non-limiting example of implementation thereof, made with reference to the attached drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0039] [0039]FIG. 1 shows a block diagram of an embodiment of implementation of the process for the separation and recovery of carbon dioxide from a combustion exhaust gas according to the present invention.
DETAILED DESCRIPTION
[0040] With reference to the annexed figure, block 1 refers to an equipment of a domestic or industrial plant for the combustion of a fuel, in particular a fossil fuel, with air.
[0041] Block 2 refers to a heat exchanger for cooling an exhaust gas flow at high temperature produced by the combustion within block 1 .
[0042] The gaseous composition of this exhaust gas flow mainly comprises carbon dioxide, water, oxygen and nitrogen and, to a limited extent, nitric and sulphur oxides (SOx and NOx).
[0043] Block 3 refers to a compression unit adapted to compress up to a desired pressure the exhaust gas flow cooled within block 2 . Such block 3 is optional and becomes particularly important when for the carbon dioxide separation PSA type molecular sieves or hollow fibre membranes are used, since it is necessary to suitably compress the exhaust gas to be treated.
[0044] If TSA type molecular sieves are used, the block 3 can be omitted or, alternatively, it may-consist of a simple fan.
[0045] Block 4 refers to a gas semipermeable material, such as a membrane or a molecular sieve, to separate the gaseous flow comprising high concentrated carbon dioxide from the exhaust gas flow coming from the block 2 or block 3 as it will be explained later on in the present description.
[0046] Block 5 refers to another compression unit adapted to compress a gas flow comprising high concentrated carbon dioxide coming from the block 4 .
[0047] Block 6 refers to another heat exchanger adapted to heat a portion of gas flow comprising high concentrated carbon dioxide coming from the block 4 .
[0048] The flow line 7 indicates an exhaust gas flow at high temperature produced by the combustion within block 1 .
[0049] This exhaust gas flow is then fed to the block 2 where it is cooled down to a temperature comprised between 20° and 80° C.
[0050] The flow line 8 indicates the cooled gas flow coming from the block 3 . If the gas semipermeable material of block 4 consists of a hollow fibre membrane or by a PSA type molecular sieve, the exhaust gas flow 8 is firstly compressed in the block 3 at a pressure comprised between 1 abs bar and 20 abs bar, and then fed, as indicated by the flow line 9 , to the block 4 .
[0051] On the contrary, if the gas semipermeable material of block 4 consists of a TSA type molecular sieve, block 3 may be omitted and therefore the exhaust gas flow 8 coming from the block 2 is directly fed to the block 4 .
[0052] The gas semipermeable material of block 4 provides for the separation of a gas flow comprising high concentrated carbon dioxide from the exhaust gas flow 8 or 9 .
[0053] Preferably, this material consists of a TSA type molecular sieve that allows the preferential passage of nitrogen, adsorbing at the same time the mixture gaseous components containing oxygen, i.e. mainly carbon dioxide, water and oxygen.
[0054] Therefore, as indicated by the flow line 10 , at the outlet of the block 4 a gas flow is obtained comprising mainly nitrogen that is dispersed in the atmosphere.
[0055] In order to obtain a desorption of the, carbon dioxide and the other oxygenated compounds adsorbed in the block 4 , an interruption of the exhaust gas flow 8 or 9 to the block 4 and a regeneration of the hollow fibre membrane or of the molecular sieve represented in the block 4 is provided.
[0056] In the case of a hollow fibre membrane or a molecular sieve of the PSA type, the regeneration is carried out by decreasing the pressure in the block 4 (decompression) in such a way as to separate the carbon dioxide adsorbed in such materials.
[0057] In the case of a TSA type molecular sieve, the regeneration is carried out in a manner that will be explained later on in the present description.
[0058] As indicated by flow line 11 , from the regeneration step a gaseous flow is thus obtained, which turns out to have a carbon dioxide concentration higher than that in the exhaust gas flow 8 or 9 . Also the concentration in the gaseous flow 11 of the other gaseous components adsorbed in the block 4 is higher than the concentration of these components in the exhaust gas flow 8 or 9 .
[0059] Then, the gaseous flow 11 comprising high concentrated carbon dioxide can be used as a feed raw material in suitable industrial processes, directly or after having been further treated. Alternatively, the flow 11 can be liquefied or stockpiled in a suitable manner in order to be subsequently used according to specific needs.
[0060] For instance, the gaseous flow 11 can be compressed in block 5 to a suitable pressure, and the so obtained gaseous flow indicated by flow line 12 can be directly utilized as feed raw material in a plant for the production of urea or methanol.
[0061] Anyway, should the complete or partial removal from the flow 11 of gaseous components, such as oxygen and nitric or sulphur oxides (SOx, NOx) be necessary, then it is possible to arrange for the passage of the gaseous flow 11 under suitable operative conditions through one or more membranes or molecular sieves and/or for the treatment of the flow 11 with other types of separation systems.
[0062] In this case, the flow 11 completely or partially purified from the above mentioned gaseous components can be compressed in the block 5 and used in a plant for the urea of methanol production as a feed raw material.
[0063] In the present example, a flow portion 11 comprising high concentrated carbon dioxide, indicated by the flow line 13 , is heated in block 6 and fed to block 4 through the flow line 14 , in order to regenerate the TSA-type molecular sieve.
[0064] Alternatively, for the above-mentioned regeneration it is possible to use water steam at high temperature.
[0065] The regeneration implies the desorption of the gaseous components, and in particular of carbon dioxide retained into the micropores of the TSA-type molecular sieve, which are recovered in the flow 11 .
[0066] Obviously a man skilled in the art can make a plurality of modifications to the process according to the invention in order to fulfill specific and peculiar requirements, all falling within the scope of protection of the invention as defined in the following claims. | A process for the separation and recovery of carbon dioxide from waste gases produced by combustible oxidation is described comprising the steps of feeding a flow of waste gas to a gas semipermeable material, separating a gaseous flow comprising high concentrated carbon dioxide from said flow of waste gas through said gas semipermeable material, and employing at least a portion of said gaseous flow comprising high concentrated carbon dioxide as feed raw material in an industrial production plant and/or stockpiling at least a portion of said gaseous flow comprising carbon dioxide. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a method of and an apparatus for forming groups of face-to-face stacked flat articles, particularly confectionery items, such as crackers or cookies. The apparatus includes a conveyor on which the items are advanced in a flat-lying state. The items are generally randomly arranged in rows and columns and thus form what will be hereafter referred to as an "item carpet". The apparatus further includes item group-forming chambers which arrange the items from the item carpet into groups of stacked items.
A method and an apparatus of the above-outlined type is known, for example, from Swiss Patent No. 521,265. In this prior art construction the items of the item carpet are first arranged into columns, and, subsequently, the items are accumulated by gripping fingers which advance the items above a stage. In case underneath the stage two items are in a superposed state, they are shifted by pushers into group-forming chambers where the items are stacked. While such an apparatus has proven generally to be satisfactory, it has the disadvantage that it requires separate column forming, guiding and item accumulating devices. Such arrangements limit the capacity of the apparatus and also, the items must be relatively robust. The known apparatus is inadequate for items such as delicate, fragile cookies and for certain particular item configurations.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method and apparatus of the above-outlined type which operates with a high output and yet ensures a gentle handling of the items.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for forming groups of flat, face-to-face stacked items includes a conveyor belt for receiving the items in a flat-lying orientation; a motor for driving the conveyor belt to advance the items disposed thereon in a conveying direction; a sensor disposed above the conveyor belt for determining a position of individual items on the conveyor belt; a plurality of group-forming chambers; a plurality of serially disposed gripping units situated downstream of the sensor as viewed in the conveying direction for grasping the items advanced on the conveyor belt and for introducing the items into the group-forming chambers; and a control device having an input connected to the sensor and outputs connected to the gripping units for controlling the gripping units as a function of signals applied to the control device by the sensor.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic top plan view of an apparatus incorporating the invention.
FIG. 2 is a schematic fragmentary perspective view of a preferred embodiment of the invention.
FIG. 3 is a schematic front elevational view, partially in section, of a part of the preferred embodiment.
FIG. 4 is a schematic side elevational view of the structure shown in FIG. 3.
FIG. 5 is a schematic side elevational view of another preferred embodiment of the invention.
FIG. 6 is a schematic perspective view of still another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the operational principle of the invention.
On a conveyor belt 1 individual, flat-lying confectionery items 3 are advanced in a conveying direction A as an item carpet 2 in a slightly spaced, side-by-side and serially arranged orientation as they emerge from a non-illustrated baking oven. A sensor station 4 provided with a plurality of reflecting light barriers determines the position of the items on the conveyor belt 1. Downstream of the sensor station 4--as viewed in the conveying direction A--on either side of the conveyor belt 1 a plurality of consecutive stations B, C, D and E are arranged which are provided with gripping devices for successively removing items 3 from the belt 1 and for stacking the flat-lying items on one another in item group-forming chambers 5. The group-forming chambers 5 are schematically shown in FIG. 1 as packaging containers, each accommodating three stacks 7 of items 3. The item quantity decrease on the conveyor 1 in the conveying direction A thus equals the item quantity increase in the item group-forming chambers 5.
In the schematic FIG. 2, only the outermost right-hand longitudinal marginal zone of the conveyor belt 1 is shown (as viewed in the conveying direction A) and, accordingly, only the outermost, right-hand column 10 of the item carpet 2 of FIG. 1 is illustrated and also, only the group-forming station B is shown. The item group-forming chambers 5 are formed by intermediate spaces defined between fork-shaped pushers 11 which are secured at uniform distances to an endless belt 12 driven by a motor 13. The tines of the pushers 11 project through slots 14 provided in a sloping ramp 15. The pushers 11 shift the formed stacks 7, for example, to a packing machine 16. Such a conveyance to the machine 16 may be effected directly as illustrated or with the intermediary of an item accumulating (storing) line.
In FIG. 2, of the sensor station 4 illustrated in FIG. 1 only the outermost optical barrier 19 is shown which scans the items 3 of the outermost column 10 and reports their position on the conveyor belt 1 to a control device 20. For purposes of correlation, the control device 20 further receives a signal of an angular position transmitter 21 which is coupled to the rotary shaft 22 of the motor 23 driving the conveyor belt 1. The gripping unit 25 in the station B includes three grippers 26 arranged in series in the conveying direction A. The grippers 26 are each guided in a longitudinal guide 27 and are displaceable in the height direction Z by a crank 29 each driven by a separate motor 28. The three guides 27 are mounted on a common shaft 30 which is oriented parallel to the conveyor belt 1 and the conveying direction A and is driven by a motor 31. Each gripper 26 is provided at its lower end with a suction head 32 which is coupled to a non-illustrated suction line. The motors 13, 28 and 31 are connected with the control device 20.
In the description which follows, the operation of the above-described device will be set forth.
The randomly distributed items 3 on the conveyor belt 1 are scanned by the optical barriers 19 and the position of the items on the belt 1 is stored in the control device 20 in conjunction with signals transmitted by the angular position sensor 21 and representing the angular orientation of the conveyor belt drive shaft 22. As the leading item 3 reaches the downstream-arranged first gripper 26 the control device 20 energizes the motor 28 of that gripper, causing the latter to be lowered and to engage and lift the item 3 from the belt 1 with the suction head 32. The two immediately successive items 3 are grasped and lifted in a similar manner by the other two grippers 26. As soon as all three grippers 26 have each grasped an item, the motor 31 rotates the shaft 30 and thus the three grippers 26 are moved jointly into a position of the item group-forming chambers 5 and the vacuum supply to the grippers 26 is interrupted for a short period so that the items are deposited in the chambers 5 to form stacks 7 therein. Thereafter, the grippers 26 are moved into their earlier position by the motor 31 in order to grasp and lift the successive items 3 of the item column 10. After each such step or after every other such step, the belt 12 is moved by the motor 13 through a distance corresponding to the length of one chamber. In the variant schematically shown in FIG. 1 where packaging containers 6 are being filled, these containers 6 may, in the alternative, remain stationary in the same position until they are filled and may thereafter be replaced by respective empty containers 6.
The above-described apparatus may operate at a very high speed because the items 3 need not be accumulated and they are grasped during their advance in the conveying direction A. In this apparatus no alignment of the items with respect to one another is necessary so that the items may be directly grasped by the apparatus as they are delivered, for example, from a baking oven or another upstream-arranged item handling machine. Since no item accumulating conveyor lengths are necessary, the items are handled in a very gentle manner so that the apparatus may be well used even for very delicate, fragile items. By virtue of the fact that no aligning and item accumulation devices are needed and because a plurality of grippers 26 may be shifted jointly, the structural length of the apparatus is short as compared to conventional stacking devices.
Further, a very high degree of operational safety may be ensured by arranging, downstream of the normally operating gripping units 25, a standby gripping unit which may serve more than one column 10. In case of breakdown of one of the gripping units 25, the standby gripping unit may assume its function. Further individual items which escaped the regular gripping units 25 may be caught by the standby gripping unit by providing each gripper 26 with a vacuum sensor which reports the proper grasping of an item 3 to the control device 20.
The described apparatus is of modular construction and may thus be manufactured economically. It is, for example, also feasible to perform with an additional, down-stream arranged gripping unit 25 a stack complementation preceded by a weight or length check of the stack 7. Such a downstream-arranged gripping unit may be, as commanded by the control device 20, supplied with the required number of items 3 by one of the upstream-arranged gripping units 25 in case such gripping unit exceeds the required number of items.
Turning to FIGS. 3 and 4, the gripping unit 25 schematically shown in FIG. 2 is illustrated in more detail. The gripper 26 is suspended from a guide 27 which, in turn, is pivotally supported by a horizontal shaft 30. The motor 31, during a 180°-turn, rotates the shaft 30 by means of a crank 34, a push rod 35 and a lever 36 to move the gripper 26 into the dash-dotted position shown in FIG. 3. The guide 27 is formed of two pairs of circumferentially grooved rollers 37 engaging respective rails 38 of wedge-shaped cross section. The item group-forming chambers 5 are packaging containers 6 similarly to FIG. 1. The tubular gripper 26 is connected by a hose 39 to a vacuum source, not shown.
The embodiment shown FIG. 5 differs from that of FIG. 4 in that the suction heads 32 of the grippers 26 are shiftable individually transversely to the conveying direction A. For this purpose the tubes 43 of the grippers 26 are angled twice underneath a rotary bearing 44 so that the suction heads 32 are disposed eccentrically to the rotary axis 45. To each gripper tube 43, underneath the bearing 44, a gear 46 is secured which meshes with a pinion 47 which, in turn, is driven by a further motor 48. By virtue of this arrangement, each suction head 32, driven by the respective motor 48, may be shifted transversely to the conveying direction A. This is particularly useful if the item carpet 2 does not form item columns 10. In such a case, for controlling the motors 48, the sensor station 4 has to transmit signals representing the position of the items transversely to the conveying direction A. This is feasible, for example, by using a significantly greater number of optical barriers 19 or a TV camera associated with an appropriate evaluating device.
In the embodiment according to FIG. 6, the ramps 15 (only one shown) and the shaft 30 are oriented transversely to the conveying direction A. Each ramp 15 extends above the conveyor belt 1. The item carpet 2 is formed of aligned rows and columns 10 so that all the grippers 26 of the gripping unit 25 have a common motor 28 for executing the lifting and lowering motions thereof. In case of irregular distances between the items 3 within the columns 10 each gripper 26 would need its own lifting motor similarly to the embodiment shown in FIGS. 2, 3, 4 and 5.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | An apparatus for forming groups of flat, face-to-face stacked items includes a conveyor belt for receiving the items in a flat-lying orientation; a motor for driving the conveyor belt to advance the items disposed thereon in a conveying direction; a sensor disposed above the conveyor belt for determining a position of individual items on the conveyor belt; a plurality of group-forming chambers; a plurality of serially disposed gripping units situated downstream of the sensor as viewed in the conveying direction for grasping the items advanced on the conveyor belt and for introducing the items into the group-forming chambers; and a control device having an input connected to the sensor and outputs connected to the gripping units for controlling the gripping units as a function of signals applied to the control device by the sensor. | 1 |
FIELD OF THE INVENTION
[0001] The invention relates generally to printers, and more particularly to a pinch control in a printer for controlling a pinch force exerted on a medium.
BACKGROUND OF THE INVENTION
[0002] A printer generally uses a linefeed roller and an output roller to drive a medium in the printer during a printing process. The linefeed roller and the output roller are driven by a servo motor. A pick motor controls a pick system to pick up the medium, for example a paper, from an input tray and feeds it to the linefeed roller. The linefeed roller drives the paper into a printing area where droplets of ink are sprayed onto the paper from an ink cartridge.
[0003] One or more pinch rollers are biased against the linefeed roller so that the paper is driven between the pinch rollers and the linefeed roller. Since the pinch rollers are biased against the linefeed roller, a pinch force is exerted on the paper. The linefeed roller and the pinch rollers control the advancement of the paper during most of the printing process.
[0004] In some printing processes, once a bottom of form (BOF) edge of the paper leaves the linefeed roller and the pinch rollers (the pinching point), the output roller drags the paper from the printing area to an output tray. One or more star wheels are normally used together with the output roller to drag the paper from the printing area. The star wheels are located adjacent to the output roller, with the spikes of the star wheels touching the output roller. The paper is dragged out of the printing area between star wheels and the output roller.
[0005] The configuration of the printer described above allows the printer to continue to print on the paper even when the paper has left the pinching point. This enables the printed image on the paper to have very small BOF margin, or even full bleed printing.
[0006] However, paper positioning errors normally occur when the control of the driving of the paper is changed from the linefeed roller to the output roller. Such positioning errors are called BOF transition error (BOFTE). The BOFTE are more prominent in high quality photo printing. One of the main causes of BOFTE is the result of pinch rollers squeezing the bottom edge of the paper when the paper leaves the pinching point.
[0007] Special print mode may be applied during or after transition from the linefeed roller to the output roller to smoothen printing defects caused by BOFTE. It is also possible to use special print head swath shifting corresponding to the paper movement during the transition to minimize such printing defects. However, the printing defects caused by BOFTE still could not be eliminated using such methods, and these methods may also cause additional printing defects.
[0008] It is desirable to provide a method and a system to reduce BOFTE in small BOF margin and full bleed printing.
SUMMARY OF THE INVENTION
[0009] In an embodiment, a pinch control apparatus in a printer for controlling a pinch force exerted on a medium which is being fed into a printing zone is provided. The pinch control apparatus includes a camshaft rotatably mounted across a width of the medium, at least one cam attached to the camshaft, a plunger and a biasing rod. The cam has a predefined profile and is able to rotate with the camshaft. The plunger abuts the predefined profile of the at least one cam. The biasing rod extends from a pinch plate to the plunger to bias the pinch plate to a linefeed roller for exerting the pinch force on the medium therebetween. The pinch force exerted on the medium is controllable by the rotation of the camshaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The embodiments of the invention will be better understood in view of the following drawings and the detailed description.
[0011] FIG. 1 shows a cross-sectional view of a part of a paper driving mechanism in a printer.
[0012] FIG. 2 shows an isometric view of a pinch control apparatus with a pinch support holder and a transmission gear train according to an embodiment.
[0013] FIG. 3 a shows a cross-sectional view of the pinch control apparatus with a cam in a home position according to an embodiment.
[0014] FIG. 3 b shows the cross-sectional view of the pinch control apparatus with the cam in a position where the pinch force exerted by the pinch roller on the linefeed roller is zero according to an embodiment.
[0015] FIG. 4 shows a cross-sectional view of a protrusion of the pinch support holder acting as a stopper for the cam according to an embodiment.
[0016] FIG. 5 shows the transmission gear train with a selector gear disengaged from a connecting gear according to an embodiment.
[0017] FIG. 6 shows the transmission gear train with the-selector gear engaged with the connecting gear according to an embodiment.
[0018] FIG. 7 shows a cross-sectional of a pick motor and its relation with an idler gear of the transmission gear train according to an embodiment.
[0019] FIG. 8 shows a flow chart of a printing process with pinch control according to an embodiment.
[0020] FIG. 9 a shows a cross-sectional view of the pinch control apparatus having a second cam according to an embodiment.
[0021] FIG. 9 b shows the cross-sectional view of the pinch control apparatus with the second cam in a position pushing the pinch plate, resulting in the pinch roller to be lifted away from the linefeed roller according to an embodiment.
[0022] FIG. 10 shows a cross-sectional view of a protrusion of the pinch plate acting as a stopper for the second cam according to an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 shows a cross-sectional view of a part of a paper driving mechanism in a printer. The paper driving mechanism includes a linefeed roller 101 , an output roller 102 , a servo motor 103 , a pinch roller 104 and a star wheel 105 . The servo motor 103 drives the linefeed roller 101 and the output roller 102 . The pinch roller 104 is mounted at one end of a pinch plate 106 . The other end of pinch plate 106 is attached to a spring 107 . The pinch plate 106 is pivoted 108 between the two ends. The pinch roller 104 is biased by the spring 107 to the linefeed roller 101 .
[0024] Although only one pinch plate 106 is shown, and one spring 107 is attached to the pinch plate 106 , it should be noted that it is possible that the paper driving mechanism includes more than one pinch plates 106 with one or more springs 107 attached to each pinch plate 106 in other embodiments. Also, each pinch plate 106 may include one or more mounted pinch rollers 104 . Similarly, the paper driving mechanism may also include more than one star wheels 105 in other embodiments.
[0025] The spring 107 is attached to the pinch plate 106 at one end, and to a plunger 109 at the other end. The plunger 109 sits or abuts on a cam 120 which is attached to a camshaft 110 . The structure of the plunger 109 , the cam 120 and the camshaft 110 will be described in greater detail later.
[0026] FIG. 2 shows an isometric view of the pinch control apparatus with a pinch support holder 130 and a transmission gear train 131 . It can be seen that the pinch control apparatus includes four plungers 109 , four springs 107 and four pinch plates 106 . Each spring 107 is attached to one of the plungers 109 . It should however be noted that the pinch control apparatus may include any number of plungers 109 , springs 107 , and pinch plates 106 in other embodiments. The camshaft 110 is supported by the pinch support holder 130 , and is rotatable with respect to the pinch support holder 130 . In an embodiment, the pinch plate 106 is pivoted 108 on the pinch support holder 130 .
[0027] The transmission gear train 131 transfers a torque or rotation from a pick motor 145 (see FIG. 7 ) to the camshaft 110 . The transmission gear train 131 has a reduction ratio of 18.9 in one embodiment. The pick motor 145 is normally engaged to a pick system in a printer to pick paper from an input tray and feeds it to a turn roller 113 . The turn roller 113 then feeds the paper to the linefeed roller 101 which drives the paper for printing.
[0028] The transmission gear train 131 includes an idler gear 132 rotatably mounted on a same shaft 129 of the linefeed roller 101 , a selector gear 133 , two connecting gears 134 , 135 and a camshaft gear 136 . The idler gear 132 is able to rotate independently from the shaft 129 of the linefeed roller 101 . The selector gear 132 is engaged to the idler gear 133 , and can be selected using a selector mechanism 137 to be engaged with the connecting gear 134 or with another system such as the pick system.
[0029] FIG. 3 a shows a cross-sectional view of the pinch control apparatus according to an embodiment. A cam 120 is provided on the camshaft 10 , and has a predefined profile 120 a . The plunger 109 sits on or abuts the profile 120 a of the cam 120 . The profile 120 a of the cam 120 is defined in such a manner that a rotation of the camshaft 110 in a counter-clockwise direction causes the distance between the plunger 109 and the camshaft 110 to decrease. FIG. 3 b shows a cross-sectional view of the pinch control apparatus when the cam 120 is rotated in a counter-clockwise direction. As can be seen from FIG. 3 b , the distance between the plunger 109 and the camshaft 110 has decreased compared to that in FIG. 3 a . As a result, the biasing force of the spring 107 , and hence, the force exerted by the pinch rollers 104 on the linefeed roller 101 is decreased.
[0030] The pinch support holder 130 may also include a protrusion 140 for the cam 120 as shown in FIG. 4 . Similarly, the cam 120 also includes a corresponding protrusion 142 . When the camshaft 110 is rotated in the clockwise direction beyond a certain point, the protrusion 142 of the cam 120 is restrained by the protrusion 140 of the pinch support holder. Therefore, any further clockwise rotation of the camshaft 110 is prevented.
[0031] Accordingly, the protrusion 140 of the pinch support holder 130 acts as a stopper for the cam 120 and prevents the rotation of the camshaft 110 in the clockwise direction beyond an end point. Therefore the protrusion 140 may be used as a hard stop for firmware identification and counts reset for the rotation of the camshaft in the clockwise direction. The hard stop is also referred as a home position of the camshaft 110 .
[0032] In an embodiment, each spring 107 delivers approximately 650 grams of force on the pinch plate 106 when the camshaft 110 is in the home position. To keep the home position of the camshaft 110 and the force exerted by spring 107 on the pinch plate 106 stable, a 10 degrees counter-clockwise rotation of the camshaft 110 from the home position keeps the plunger 109 in the same position with respect to the camshaft 110 . Therefore, the design of the pinch control apparatus according to the embodiment is robust to any undesirable changes in the force exerted by the spring 107 due to any slight movement of the camshaft 110 at the home position. Such design robustness of the pinch control apparatus is advantageous as the constant force of approximately 650 grams exerted by the pinch plate 106 can be ensured without the need for a precise calibration of the position of the camshaft 110 to the home position.
[0033] As the camshaft 10 is further rotated 180 degrees in the counter-clockwise direction, the force exerted by the spring 107 on the pinch plate 106 , and hence the pinch force exerted on the linefeed roller 101 , decreases to approximately 0 grams. When the camshaft 100 is rotated a further 10 degree in the counter-clockwise direction beyond this point, the pinch force exerted on the linefeed roller 101 is maintained as zero.
[0034] It should be noted that the degrees of rotation of the camshaft 110 and its corresponding force exerted by the springs 107 in the above-described embodiment only illustrate one manner of implementation. Any combination of the degrees of rotation of the camshaft 110 and the corresponding forces exerted by the springs 170 are possible in other embodiments.
[0035] FIG. 5 shows the transmission gear train 131 with the selector gear 133 disengaged from the connecting gear 134 . FIG. 6 shows the transmission gear train 131 with the selector gear 133 engaged with the connecting gear 134 .
[0036] FIG. 7 shows a cross-sectional view of the pick motor 145 and its relation to the idler gear 132 in an embodiment. The pick motor 145 drives a pick motor gear 146 using a rotating shaft 147 . The pick motor gear 146 is engaged with the idler gear 132 . The rotation of the pick motor gear 146 causes the idler gear 132 to rotate. It can be seen that a clockwise rotation of the pick motor gear 146 by the pick motor 145 results in the counter-clockwise rotation of the camshaft 10 . Similarly, a counter-clockwise rotation of the pick motor gear 146 results in the clockwise rotation of the camshaft 110 .
[0037] It should be noted that it is also possible to use a separate motor in another embodiment for directly rotating the camshaft 110 . In this embodiment, the rotation of the camshaft 110 is not controlled by the pick motor 145 . Therefore, the transmission gear train 131 for connecting the pick motor 145 to the camshaft 110 is not needed.
[0038] When a print job is initiated, a medium, such as a paper, is picked from an input tray 111 . The paper travels along a path indicated by the arrow 112 (see FIG. 1 ) and is driven by a turn roller 113 into a paper guiding zone 114 . A paper sensor 115 senses the presence of the paper in the guiding zone 114 and an Out Of Paper Sensor (OOPS) 116 senses the Bottom of Form (BOF) edge of the paper.
[0039] During a printing process, the paper in the guiding zone 114 is driven into a printing zone 117 by the linefeed roller 101 and the pinch rollers 104 . In the printing zone 117 , droplets of ink are ejected from an ink cartridge 118 onto the paper. Once the OOPS detects that the paper BOF edge of the paper is leaving the linefeed roller 110 , the linefeed pinching force is released. Hence, the output roller 102 and the star wheels 105 drive the paper from the printing zone 117 into an output tray (not shown).
[0040] FIG. 8 shows a flow chart of a printing process for printing on paper according to an embodiment. Step 800 includes picking a paper by the pick motor 145 . Step 801 includes detecting the presence of paper using a sensor 115 provided in the guiding zone 114 of the printer. Step 802 includes switching the selector mechanism 137 to engage the selector gear 133 to the connecting gear 134 when the paper is detected.
[0041] Step 803 includes rotating the pick motor 145 in the counter-clockwise direction until the cam 120 touches the protrusion 140 of the pinch support holder 130 . This step 803 ensures the camshaft 110 is in its home position.
[0042] Step 804 includes advancing the paper by the linefeed roller 101 into the printing area 117 to be printed. The paper is advanced into the printing area 117 in a series of paper advancement steps. Step 805 includes detecting the bottom of form (BOF) edge of the paper. The BOF edge of the paper can be detected using the Out-Of-Paper Sensor (OOPS) 116 in an embodiment. Step 806 includes rotating the pick motor 145 in the clockwise direction corresponding to the paper advancement. Specifically, the pick motor 145 is rotated in the clockwise direction in predefined steps or counts for every certain number of paper advancement steps. Each predefined step or count of the pick motor 145 translates to a counter-clockwise rotation of the camshaft 110 . The pinch force exerted on the paper between the pinch rollers 104 and the linefeed roller 101 decreases when the pick motor 145 is rotated in the clockwise direction. The pinch force exerted on the paper gradually becomes zero when the paper has advanced a predetermined number of steps.
[0043] Step 807 includes checking if the paper advancement has exceeded the predetermined number of steps for the pinch force to become zero. Step 808 includes advancing the paper into the printing zone 117 by the output roller 102 and the star wheels 105 for BOF printing when the pinch force becomes zero. When the printing is completed, the paper is ejected by the output roller 102 in step 809 .
[0044] Step 810 includes resetting the position of the camshaft 110 to the home position by rotating the pick motor 145 in the counter-clockwise direction. This sets the camshaft 110 back to its home position so that the spring 170 delivers a biasing force of 650 g to the pinch plate 106 . Step 811 includes switching the selector mechanism 137 to engage the selector gear 133 to the pick system for picking another paper into the guiding zone. Steps 800 to 810 are repeated for controlling the pinch force on another paper during the printing process.
[0045] The pinch control apparatus as described in the above embodiments allows the pinch force exerted on the paper to be gradually reduced to zero before the BOF edge of the paper leaves the pinching point. Therefore, a watermelon seed effect causing paper feeding error during a transitional point from the linefeed roller to the output roller is eliminated. The watermelon seed effect is a phenomenon when the pinch rollers squeezes the bottom edge of the paper during printing, and causing the paper to over advance (pushed forward suddenly) when the bottom edge leaves the pinch point. The watermelon seed effect is one of the main causes of Bottom of Form Transition Error (BOFTE) as already described earlier.
[0046] In an embodiment, the camshaft 110 further includes a second cam 121 arranged adjacent to each cam 120 . The second cam 121 has a profile 121 a which abuts the pinch plate 106 as shown in FIG. 9 a and FIG. 9 b.
[0047] The profile 121 a of the second cam 121 is defined in a manner such that when the camshaft 110 is rotated in the counter-clockwise direction beyond the position when the pinch force exerted on the linefeed roller 101 has decreased to zero, the end of the pinch plate 106 where the springs 107 are attached to are pushed away from the camshaft 110 by the second cam 121 as shown in FIG. 9 b . As a result, the pinch plate 106 is rotated about its pivoted point 108 , causing the other end of the pinch plate 106 where the pinch rollers 104 are mounted on to be lifted from the linefeed roller 101 .
[0048] A final hard stop may be provided as an end point for the rotation of the camshaft 110 in the counter-clockwise direction. The final hard stop may be provided as a protrusion 141 extending from the pinch plate 106 as shown in FIG. 10 in one embodiment. In this embodiment, the second cam 121 includes a corresponding protrusion 143 . When the camshaft 110 is rotated in the counter-clockwise direction beyond the end point, the protrusion 143 of the second cam 121 is restrained by the protrusion 141 of the pinch plate 106 . Therefore, any further counter-clockwise rotation of the camshaft 110 is prevented. The final hard stop may also be controlled by motor stall torque values using firmware in another embodiment.
[0049] Thus the embodiment described above not only is able to control the pinch force exerted on the medium during printing, but is also able to control the lifting of the pinch rollers 104 from the linefeed roller 101 . The lifting of the pinch rollers 104 from the linefeed roller 101 allows the paper to be reversed into the guiding zone 114 even when the paper has left the pinching point. This allows small margin or even borderless duplex printing even when a duplexer is arranged at a rear end of the printer. The lifting of pinch rollers 104 may also allow a thick medium, such as a CD, to be fed into the paper guiding zone 114 from a front end of the printer (the same end where the input and output tray are) for printing.
[0050] It should also be noted that the pinch force exerted on the medium may be adjusted to any desired level according to different media properties for different print jobs. Also, by varying the profiles 120 a of the cams 120 , different pinch force may be applied on the medium from different pinch plates 106 in accordance to any special print requirements. Furthermore, pinch rollers may be separately controlled to be lifted from the linefeed roller, and hence from the medium, during printing by varying the profiles 120 a of the cams 120 of the different pinch plates 106 . This separate control of pinch plates 106 lifting can be used to prevent certain area of printed media from being contacted by the pinch rollers 104 .
[0051] Although the present invention has been described in accordance with the embodiments as shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | A pinch control apparatus in a printer for controlling a pinch force exerted on a medium which is being fed into a printing zone is provided. The pinch control apparatus includes a camshaft rotatably mounted across a width of the medium, at least one cam attached to the camshaft, a plunger and a biasing rod. The cam has a predefined profile and is able to rotate with the camshaft. The plunger abuts the predefined profile of the at least one cam. The biasing rod extends from a pinch plate to the plunger to bias the pinch plate to a linefeed roller for exerting the pinch force on the medium therebetween. The pinch force exerted on the medium is controllable by the rotation of the camshaft. | 1 |
BACKGROUND OF THE INVENTION
Inasmuch as most passenger vehicles and the like include rear overhang portions which project considerably rearward of the rear wheels of the vehicle and trailer hitches are constructed in a manner such that the forward tongue portion of a trailer towed behind such vehicles are actually coupled to the vehicles, at a point spaced slightly rearward of the rear bumpers of the vehicles any slight right and left lateral shifting of the forward end of the towing vehicle results in left and right lateral shifting, respectively, of the forward end of the trailer. This operational feature of the combination of a passenger vehicle and a trailer being towed there behind can be very dangerous, especially if the trailer is not properly loaded in a manner such that the gross load represented by the trailer has its center of gravity disposed forward of the wheels of the trailer. This is especially true when a trailer being towed has a large side elevational area upon which crosswind gusts and slip stream blasts may react. Accordingly, a need exists for a hitch connection between a vehicle and a trailer which will eliminate the sway tendencies of the vehicle and trailer combination as a result of slight lateral shifting of the forward end of the towing vehicle.
Examples of various different forms of anti-sway trailer hitches including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 2,201,660, 2,913,256, 3,254,905, 3,785,680, 3,787,077 and 3,825,282.
BRIEF DESCRIPTION OF THE INVENTION
The anti-sway trailer hitch of the instant invention is constructed in a manner whereby slight lateral deflections to the right and left by the front end of a towing vehicle will not be directly transmitted to the trailing vehicle in the form of left and right lateral swaying movements.
The anti-sway trailer hitch is relatively simple in construction and includes only three major components other than the usual forwardly projecting trailer tongue assembly and may therefore be readily incorporated into the manufacture of new trailers and trailer hitches as well as retrofitted to existing trailers and trailer hitches.
The main object of this invention is to provide an anti-sway trailer hitch which may be utilized to couple a trailer to a towing vehicle in a manner such that slight lateral left and right movements of the forward end of the towing vehicle will not be transferred into lateral left and right movements, respectively, of the forward end of the towing vehicle.
Another object of this invention is to provide an anti-sway trailer hitch which may be readily retrofitted to existing trailer hitches and trailers.
Still another object of this invention is to provide a trailer hitch including an adjustment feature enabling adjustment of the anti-sway action of the hitch in accordance with the gross load represented by the associated trailer.
A final object of this invention to be specifically enumerated herein is to provide an anti-sway trailer hitch in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a conventional towing vehicle and trailer combination incorporating the anti-sway trailer hitch of the instant invention;
FIG. 2 is a top plan view similar to FIG. 1 but illustrating the manner in which the forward end of the trailer continues to move in a straight line path even though the forward end of the towing vehicle has been slightly shifted to the left from a straight line path of movement;
FIG. 3 is a fragmentary enlarged top plan view of the adjacent portion of the towing vehicle and trailer and illustrating the hitch construction in operative association with the towing vehicle trailer hitch and the forwardly projecting tongue assembly of the trailer;
FIG. 4 is a fragmentary longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 4--4 of FIG. 3; and
FIG. 5 is a fragmentary transverse vertical sectional view taken substantially upon the plane indicated by the section line 5--5 of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring now more specifically to the drawings the numeral 10 generally designates a towing vehicle in the form of a conventional passenger vehicle and a box body equipped trailer is referred to in general by the reference numeral 12. The vehicle 10 includes a rear mounted trailer hitch 14 incorporating a transverse bar 16 from which a conventional ball hitch member 18 is supported.
The trailer 12 includes a frame 20 including a forwardly projecting tongue assembly 22 and it may be seen from FIGS. 1 and 2 of the drawings that the longitudinal center of the box-type body 24 supported from the frame 20 is disposed at least slightly forward of the axle of the trailer from which opposite side wheels 26 are journalled. This placement of the body 24 relative to the wheels 26 and the inclusion of the forwardly projecting tongue assembly 22 tends to ensure that a load supported within the body 24 will exert a reasonable downward force on the forward end of the tongue assembly 22 so that when the tongue assembly 22 is coupled to the rear of the vehicle 10, the tendency of the trailer 12 to sway back and forth will be reduced.
Conventionally the tongue assembly 22 is provided with a slight-y forwardly projecting extension including a socket hitch member releasably coupled to the ball hitch member 18.
However, inasmuch as the bar 16 and ball hitch member 18 are disposed appreciably rearward of the rear wheels 28 of the vehicle 10 any tendency of the forward end of the vehicle to shift laterally to the right and left will result in the ball hitch member 18 being shifted to the left and right, respectively, and thus the forward end of the tongue assembly 22 to be shifted to the right and left. This inherent operation of a vehicle and trailer combination tends to amplify the swaying movements exerted on the vehicle and trailer combination by crosswind gusts and slip stream blasts of large vehicles passing the vehicle and trailer combination. Accordingly, even if the trailer 12 is properly loaded, a swaying movement may be imparted to the vehicle 10 and trailer 12.
In order to eliminate such swaying movements the anti-sway trailer hitch 30 of the instant invention has been provided. The hitch 30 includes an elongated hitch bar including first connecting means in the form of a socket hitch member 34 supported at one end and utilized to removably universally couple the corresponding end of the bar 32 to the ball hitch member 18. The approximate longitudinal midportion of the bar 32 includes a vertical sleeve secured therethrough and a vertical pivot fastener 38 is secured through the sleeve and the forward apex portion of the tongue assembly 22 pivotally connecting the intermediate length portion of the bar 22 from the forward end of the tongue assembly 22 for oscillation about an upstanding axis.
The tongue assembly 22 includes a transverse brace member 40 spaced rearward of the point of pivotal connection of the bar 32 to the forward portion of the tongue assembly 22 and a control member 42 in the form of a bell crank incorporating right angularly disposed arms 44 and 46 is pivotally supported from the midportion of the brace member 40 by a pivot fastener 48. The arm 44 projects forwardly from the pivot fastener 48 and includes an upstanding pin 50 on its forward end rotatably and slidably received in a longitudinal slot 52 formed in the rear end of the bar 32. In addition, the arm 46 extends laterally outward to the left from the pivot fastener 48 and rotatably supports a fitting 54 therefrom for angular displacement about a vertical axis. The fitting 54 is carried by the outer end of the arm 46 and defines a horizontal bore 56 extending therethrough.
An elongated cylindrical link bar 58 has its rear end portion slidably and rotatably received through the bar 56 and a pair of stop collars 60 are mounted on the bar 56 on opposite sides of the fitting 54 and a pair of compression springs 62 are disposed on the bar 58 on opposite sides of the fitting 54. The compression springs 62 are at least slightly compressed and have their adjacent ends abutted against remote sides of the fitting 54 while their remote ends are abutted against adjacent sides of the collars 60. Thus, longitudinal shifting of the bar 58 relative to the fitting 54 is possible but yieldingly resisted by the springs 62.
The forward end of the bar 58 is pivotally anchored as at 64 to the left end of the transverse bar 16. In this manner, the bar 58 substantially parallels the bar 32 and the arm 44 when the bar 32 and arm 44 are substantially aligned.
The pivotal connection at 54 may be a ball type universal pivotal connection and structure may be provided on the free end of the pin 50 to prevent upward displacement of the rear end of the bar 32 relative to the pin 50. In addition, various different forms of pivotal connections may be substituted for the pivot fasteners 38 and 48 and any suitable form of socket hitch member may be used on the forward end of the bar 32. Still further, other hitch member constructons may be used in lieu of the socket hitch member 34 and the ball hitch member 18, if desired.
With attention now invited more specifically to FIGS. 1 and 2 of the drawings, it will be seen that straightforward movement of the vehicle 10 and trailer 12 maintains the socket hitch member 34, the pivot fastener 38 and the pin 50 along the coinciding longitudinal center lines of the vehicle 10 and trailer 12. However, should the forward end of the vehicle 10 be laterally deflected to the left as viewed in FIG. 2 of the drawings the socket hitch member 34 is displaced to the right of the center line of the previous straight path of movement of the vehicle and trailer combination with the result that the forward end of the tongue of a conventional trailer would be displaced to the right.
However, with the anti-sway hitch 30, lateral displacement of the forward end of the vehicle 10 to the left causes the pivot connection at 64 to be displaced rearward relative to the ball member 18 and thus a rearward thrust to be applied on the free end of the arm 46 by the bar 58 and the collars 60 and springs 62. The rearward thrust on the free end of the arm 46 translates into a counterclockwise angular displacement of the bell crank 42 as viewed in FIG. 2 of the drawings and thus a displacement of the rear end of the bar 32 to the left of the center line of the previous straight line path of movement of the vehicle and trailer. This in turn causes the forward end of the bar 32 to be displaced to the right of the aforementioned center line with the effect that the pivot fastener 38 remains substantially on the center line of the previous straight line path of movement of the vehicle 10 and trailer 12. Therefore, although the forward end of the vehicle 10 has been displaced to the left and may be immediately steered back to the right the trailer 12 will experience continued straight line movement. Of course, if the wheels of the vehicle 10 in FIG. 2 are turned to the left in order to execute a left hand turn the trailer 12 will follow the vehicle 10 through the turn.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A hitch connection is provided for use between a towing vehicle and a trailer and includes structure whereby slight right and left lateral movement of the forward end of the towing vehicle will not be translated into left and right lateral movement, respectively, of the forward end of the trailer and thereby eliminates the tendency of a trailer to sway back and forth during crosswind gusts and as a result of the slip stream of a large vehicle such as a tractor and semi-trailer combination passing a lighter vehicle towing a trailer. | 1 |
RELATED APPLICATIONS
[0001] This application claims priority from U.S. application Ser. No. 10/847,134, filed May 17, 2004, which claims priority from U.S. application Ser. No. 10/173,070, filed Jun. 17, 2002, which claims priority to U.S. Provisional Application Ser. No. 60/298,559, filed Jun. 15, 2001.
FIELD OF THE INVENTION
[0002] This invention relates to phthalate polyester-based compositions and high dimensional stability all water-blown spray polyurethane foams derived from such compositions. More particularly, it relates to phthalate polyester-based compositions comprising a polyester polyol, a cell opening agent, a catalyst, and water. The invention also relates to methods for preparing the phthalate polyester-based compositions and methods of producing spray foams therefrom. Further, the invention relates to the use of such foams as insulation materials, especially roof insulation materials.
DESCRIPTION OF THE RELATED ART
[0003] In the manufacture of refrigeration cabinets, picnic coolers, doors, and other insulated containers, polyurethane foam is poured in place between two substrates defining a cavity. In the production of roofing insulation, polyurethane foam is typically sprayed into place.
[0004] There are several desirable criteria that polyurethane foam should possess. One requirement is that the polyurethane foam should flow well and/or spread evenly on a surface so that the entire cavity is filled with the foam or the entire surface area is evenly coated with the foam. If the foam prematurely gels, voids will form behind the prematurely gelled foam where the foaming mass could not reach or as in a spray foam application, the foam will not produce uniform coverage over a substrate. A second requirement is to use the least amount of raw foaming material to fill a particular cavity or cover a surface to save on raw material costs. To adequately fill all portions of the cavity and prevent the presence of voids, it is often necessary to over pack the cavity or over cover the surface. The less overpacking that is necessary to completely fill the mold, however, the greater the savings in raw material costs. Thus, it is desired to form a polyurethane-filled container having the lowest density possible. A third criteria is that an alternative blowing agent to ozone depleting CFCs and HCFCs is needed. Several fully halogenated hydrocarbons (chlorofluorocarbons, commonly referred to as CFC's) normally used as blowing agents for the preparation of rigid foams are believed to cause environmental problems. For instance, CFC-11 (trichlorofluoromethane) and CFC-12 (dichlorodifluoromethane) have been implicated in the deterioration of the stratospheric ozone layer and are no longer used in the preparation of polyurethanes. Many partly halogenated hydrocarbons currently in use will no longer be available for polyurethane foam use beyond 2003.
[0005] Water is clearly viewed as the safest, most economically and ecologically attractive alternative blowing agent for the spray foam industry and many polyurethane foam manufacturers are now turning to water as the sole source of blowing agent instead of CFCs or HCFCs. However, to this point, no water blown spray foam has proven practical or effective due to a variety of significant limitations. For example, in the field of cooling containers where the foam is poured in place, water-blown rigid polyurethane foams present a unique problem. Rigid polyurethane foams blown with water tend to be closed-celled foams which shrink and pucker over a period of time after foaming and during cure. This is partly due to the migration of carbon dioxide gas, produced by the reaction of water with polyisocyanate, out of the closed cells and leaving behind a vacuum which then tightens and shrinks the foamed mass over time. Foam that shrinks in foamed-in-place applications will either pull away from a substrate, or continue to adhere to the inner surface of the substrates causing waviness and surface deformities on the substrate. The problem of foam shrinkage in CFC-blown and HCFC blown foams has not been as acute since CFC gases tend to migrate out of the closed cells very slowly over a period of months or years, if at all, resulting in a minimized pressure gradient within the foam. The problem of foam shrinkage or dimensional stability is more severe in applications such as picnic coolers where the coolers are often subject to wide temperature variations, from indoor 70-80° F. temperatures to beach temperatures in direct sun which may climb to 110-12° F., causing the gas in the cells to further expand and diffuse out.
[0006] In general, water-blown foams have suffered from poor dimensional stability, narrow processing window, high reaction exotherm, poor inter-laminar and substrate adhesion, and an inability to be processed on conventional spray foam equipment. The difficulty in processing on routine equipment has been the result of higher formulation viscosity; due to the absence of HCFC-141b blowing agent, no thinning of the resin occurs as is normally the case when such a blowing agent is present. Additionally, the requirement for increased isocyanate usage (due to the presence of significant water levels) has precluded use on conventional equipment which frequently require processing at 1:1 isocyanate/resin volume ratios. Poor adhesion characteristics are the result of increased foam friability associated with poor mixing (due to the higher resin viscosity) as well as extensive use of high functional polyether and/or Mannich-type polyols. These high functional polyols are normally required in order to provide the foamed polymer with adequate crosslink density to resist shrinkage. The high reaction exotherm, a direct result of the water-isocyanate reaction and the absence of cooling from a physical blowing agent such as HCFC-141b, contributes to foam cracking and surface blisters. The extensive heat also makes it difficult to control the reaction profile thereby limiting the range of environmental conditions under which the spray foam can be applied.
[0007] It is, therefore, desirable to produce a foam having a lower density yet which fully fills the cavity or spreads on a surface and is dimensionally stable in order to lower raw material costs. Lowering the density, however, especially in water-blown foam already having a tendency to shrink has the attendant disadvantage of further exacerbating the dimensional instability of the foam. Examples of open celled foams have been described in U.S. Pat. Nos. 5,214,076; 5,219,893; 5,250,579; 5,262,447; 5,318,997; 5,346,928; 5,350,777; 6,066,681; and 6,211,257, each of which is incorporated herein in its entirety.
SUMMARY OF THE INVENTION
[0008] The invention avoids many or all of the limitations which have excluded water-blown spray foams from commercial viability. The invention provides a solution to the dimensional stability issue. By smoothly and homogeneously opening the cells of the sprayed foam, a rapid pressure equalization is permitted after carbon dioxide departure, thereby limiting or eliminating vacuum-induced shrinkage. Through incorporation of the unique cell opening technology of the invention, formulation component modifications can readily be made without impacting foam dimensional stability. In particular, the invention makes it possible to adjust the polyol composition to lessen polymer reliance on high functional polyester or Mannich-type polyols. This results in lower formulation viscosity and improved adhesion characteristics. In one aspect of the invention, a significant proportion of low functional, i.e., 1-2 functional groups, polyester polyol is incorporated into the polyol formulation.
[0009] The invention also relies on the use of diluents in the formulation. These diluents (which are typically plasticizers) perform several functions including viscosity reduction, enhanced flammability performance, reduction in reaction exotherm, and the ability to process the resin on conventional spray foam equipment. In particular, the use of diluents as provided herein allows the foam to be processed at 1:1 A/B volume-ratio without adversely affecting the qualitative or physical properties of the polymer, wherein the “A-side” means materials comprising an isocyanate and/or isocyanurate and the “B-side” means materials comprising a polyol, as those terms are used by those skilled in the art.
[0010] In summary, the invention provides spray foam technology and spray foams that meet the physical and processing requirements stipulated by the industry; the invention provides the first and only commercially viable all water-blown spray foam available. Thus, in one aspect, the invention provides spray foams that are the product of a reaction mixture comprising a polyol blend and a polymeric isocyanate, preferably at a blend/isocyanate volume ratio of about 1:1. These blends comprise a polyol formulation, diluent, cell opening agent, and blowing agent. The blends optionally include other components as necessary to adjust, e.g., the viscosity and stability of the blend. The polyol formulation, as discussed below comprises any of a variety of polyols, i.e., polyester polyol, polyether polyol, and/or Mannich-type polyol.
[0011] The invention provides dimensionally stable, low density, all water blown polyurethane foams that are prepared predominantly with low functional polyester polyols. These foams have an open cell content sufficient to prevent shrinkage of the foam. Further, the inventive foams are of a strength sufficient to prevent shrinkage of the foam.
[0012] Accordingly, in one aspect of the invention, there is provided a method for preparing a polymeric foam comprising urethane units and having an open-cell content sufficient to resist shrinkage. This method comprises mixing an aromatic polymeric isocyanate with a dispersed polyol blend, where the polyol blend comprises:
(a) from about 20%, preferably 25%, to about 90% based on the weight of the polyol blend of a polyol formulation; (b) a blowing agent; (c) a cell opening agent which is a divalent metal salt of a fatty acid; and (d) from about 0.05 to about 50% by weight of the polyol blend of a diluent, and spraying the mixture of the aromatic polymeric isocyanate and the polyol blend to react the aromatic polymeric isocyanate and the polyol blend to form the polymeric foam.
[0017] Another aspect the invention provides polyol blends, i.e., polyol resins, suitable for preparing a polymeric foam comprising urethane units and having an open-cell content sufficient to resist shrinkage. These blends comprise:
a. a polyol formulation comprising from about 25 to about 90% by weight of the blend of a polyester polyol, a polyester polyol and/or a Mannich-type polyol; b. a blowing agent; c. a cell opening agent which is a divalent metal salt of a fatty acid; and d. from about 0.05% to about 50% by weight of the blend of a diluent.
[0022] In one aspect, the polyol blends are dispersed polyol blends.
[0023] The inventive foams are produced using cell opening agents having melting points or softening points between about 100° and about 180° C. When formulated according to the invention, these cell opening agents form part of a dispersed polyol blend having a dispersion droplet or particle size of less than about 50μ. Without being bound by a particular theory, it is believed that during the polymerization reaction, the dispersion containing the cell opener breaks down releasing the cell opener thus allowing controlled cell opening. Without being bound by a particular theory, it is believed that cell opening takes place immediately prior to polymer gelation.
[0024] The resulting low density, water blown foam is primarily an open celled foam and exhibits dimensional stability in both the sprayed free rise state as well as within a packed cavity. By “primarily open celled” is meant a foam that has a sufficient amount or percentage of open cells to resist shrinkage.
[0025] Thus, the invention encompasses methods and compositions for preparing polyurethane foams having strength and an open-cell content sufficient to prevent or resist shrinkage comprising reacting an aromatic polymeric isocyanate with a dispersed polyol blend. The dispersed polyol blend of the invention comprises a polyol formulation, a blowing agent, a cell opening agent, and a diluent.
[0026] The polyol formulation of the invention may optionally contain an acid. It has been unexpectedly discovered that the addition of an acid to a combination of a polyol, a blowing agent such as water, and a specific cell opening agent provides a dispersed polyol blend that has surprising stability. The dispersed polyol blends, when reacted with aromatic isocyanates, form open-celled, spray and pour-in-place urethane foams having excellent dimensional stability at low densities.
[0027] The invention also provides polyol blends comprising a polyol formulation, preferably containing high levels, i.e., up to about 100% by weight of the formulation, of a polyester polyol, together with a blowing agent and a cell opening agent. Optionally, the polyol blends of the invention may comprise an emulsifier.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In this document, all temperatures are stated in degrees Celsius unless otherwise indicated. All amounts, ratios, concentrations, proportions and the like are stated in weight units, unless otherwise stated, except for ratios of solvents, which are in volume units. Percentages are by weight unless otherwise indicated.
[0029] By OH value is meant hydroxyl value, a quantitative measure of the concentration of hydroxyl groups, usually stated as mg KOH/g, i.e., the number of milligrams of potassium hydroxide equivalent to the hydroxyl groups in 1 g of substance.
[0030] By NCO/OH index is meant the molar ratio, multiplied by 100, of isocyanate groups to hydroxyl groups (including those contributed by water) in the reaction between the polyol blend and the polyisocyanate.
[0031] By functionality is meant the number of reactive groups, e.g., hydroxyl groups, in a chemical molecule.
[0032] By uniform open cell content is meant a polyurethane foam having an average open cell content that does not vary substantially between two or more samples removed from the same foam material and separated in the foam material by a distance of at least about 2 cm.
[0033] The polyol blends of the invention are preferably “dispersed polyol blends.” By the term “dispersed polyol blend” is meant a polyol blend or polyol resin, i.e., a mixture comprising a polyol formulation, a cell opening agent, a diluent and a blowing agent, together with any optional components, where the cell opening agent, preferably as particles, and more preferably as particles having a mean diameter of less than about 50μ, is stably suspended in the polyol blend. Such a dispersion is stable for a period of time sufficient to allow reaction with the polyisocyanate to form an open-celled foam having an open-cell content sufficient to prevent or resist shrinkage. Preferably, the dispersed polyol blends are stable at a temperature of about 25° C. for at least about 1 week, more preferably, the blends are stable at about 25° C. for at least about 3 months.
[0034] By softening point as used herein is meant a temperature at which a material becomes more liquid, less rigid, softer, or more elastic; i.e., a temperature at or above its glass transition temperature.
[0035] As used herein, resistance to shrinkage means less than about 5% shrinkage of a polyurethane foam material.
[0036] The polyol blends of the invention preferably have particles having mean diameters of less than about 50μ, more preferably less than about 25μ, even more preferably less than about 10μ, and most preferably less than about 1μ. Smaller particles are believed to result in improved stability of the polyol blends which in turn results in improved uniformity of the open celled content of the final polyurethane foams.
[0037] The invention provides polyurethane foams suitable for use as insulating materials disposed on or between a variety of substrates. Suitable substrate materials comprise metal such as aluminum or sheet metal; wood, including composite wood, acrylonitrile-butadiene-styrene (ABS) triblock of rubber, optionally modified with styrene-butadiene diblock, styrene-ethylene/butylene-styrene triblock, optionally functionalized with maleic anhydride and/or maleic acid; polyethylene terephthalate, polycarbonate, polyacetals, rubber modified high impact polystyrene (HIPS), blends of HIPS with polyphenylene oxide; copolymers of ethylene and vinyl acetate, ethylene and acrylic acid, ethylene and vinyl alcohol; homopolymers or copolymers of ethylene and propylene such as polypropylene, high density polyethylene, high molecular weight high density polyethylene, polyvinyl chloride, nylon 66, or amorphous thermoplastic polyesters, fiberglass or fiberglass composites; roof decking materials such as gypsum board, Dens-Deck, Isoboard, Cementitious Wood Fiber (Tectum Deck), Light Weight Concrete, Modified Bitumen, and a variety of rubber based membranes.
[0038] The foams of the invention have in-place densities of from about 2 to about 5.0 lbs./ft 3 (pcf) and, in one embodiment, the foams of the invention have in-place densities of from about 2.3 to about 3.5 lbs./ft 3 (pcf). The sprayed foams of the invention have sprayed in-place densities of from about 2.0 to about 3.5 and, preferably, from about 2.3 to about 3.3, pcf.
[0039] As explained in more detail below, the foams of the invention may be water blown foams. The water blown foams according to the invention have K-factors of at least about 0.16 to about 0.24.
[0040] The polyurethane foam of the invention comprises the product of the reaction of the aromatic polyisocyanate with at least one polyol component in a polyol blend. The polyurethane foam is rigid, meaning that the ratio of tensile strength to compressive strength is high, on the order of about 0.5 to about 1 or greater, and has less than about 10 percent elongation.
[0041] The blends disclosed herein are generally free of CFC and/or hydrocarbon blowing agents and are highly suited for use in spray foam applications, e.g., insulative roof spray foams.
[0042] Although not critical to the invention, the blends of the invention may optionally contain from about 0.01 to about 50.0% by weight of a cross linking agent. Suitable cross linking agents are, for example, higher functionality alcohols such as triols or pentaerythritol.
[0043] In a preferred aspect, the invention provides polyol blends suitable for preparing a urethane foam, comprising:
(a) from about 28% to about 85%, more preferably about 80%, by weight, based on the weight of the composition, of a polyol formulation; (b) from about 0.05% to about 3%, preferably about 2.0%, by weight, based on the weight of the composition, of a cell opening agent; (c) from about 3.5%, preferably about 5%, to about 50%, preferably about 45%, by weight, based on the weight of the composition, of a diluent; and (d) from about 0.5% to about 5% by weight, based on the weight of the composition, of water.
[0048] More preferred polyol formulations of the invention comprise from about 1% to about 100% by weight of a polyester polyol or mixtures of such polyols. More preferably, the polyol formulation or mixtures thereof comprise polyester polyols having an OH value of from about 150 to about 350 and a molecular weight of from about 350 to about 700.
[0049] Even more preferred polyol formulations comprise from about 30% to about 48% of polyester polyol by weight of the polyol blend, and most preferably from about 30% to 45% of polyester polyol by weight of the polyol blend.
[0050] The blends of the invention can further comprise:
(e) from about 0.25% to about 5% by weight, based on the weight of the composition, of a urethane catalyst; and/or (f) from about 0% to about 1% by weight, based on the weight of the composition, of an acid; and/or (g) from about 0% to about 3% by weight, based on the weight of the composition, of a surfactant.
[0054] In a preferred embodiment, the polyol formulation comprises from about 1% to about 100%, more preferably about 75% to about 100%, by weight, based on the weight of the polyol formulation, of a diethylene glycol phthalate polyester polyol having an OH value of from about 150 to about 350 and comprising:
(a) the reaction product of a mixture comprising a phthalic acid compound and a low molecular weight aliphatic diol and (b) an optional nonionic surfactant, and
where the diethylene glycol phthalate polyester polyol has a molecular weight of from about 350 to about 700.
[0057] In a particularly preferred embodiment, the polyol blend comprises from about 50% to about 85% by weight of a polyol formulation comprising a modified diethylene glycol phthalate polyester polyol having an OH value of about 290 to about 325, a Mannich-type polyol having an OH value of about 415 to about 435, and diethylene glycol.
[0058] In another particularly preferred embodiment, the polyol blend comprises from about 50% to about 85% by weight of a polyol formulation comprising a modified diethylene glycol phthalate polyester polyol having an OH value of about 23 to about 350, a Mannich-type polyol having an OH value of about 415 to about 435, and diethylene glycol.
[0059] In another particularly preferred embodiment, the polyol blend of the invention comprises:
(a) from about 30% to about 35% by weight of a modified diethylene glycol phthalate polyester polyol having an OH value of about 290 to about 325 or a modified diethylene glycol phthalate polyester polyol having an OH value of about 230 to about 250; (b) from about 20% to about 30% by weight of a Mannich-type polyol having an OH value of about 415 to about 435; (c) from about 5.5% to about 9% by weight of diethylene glycol; (d) from about 1% to about 3% by weight of water; (e) from about 0.1% to about 1% by weight of the cell opener; and (f) from about 18% to about 34% by weight of the diluent.
[0066] In another preferred embodiment, the polyol blend comprises, based on the weight of the blend,
about 30% to about 35% by weight of the modified diethylene glycol phthalate polyester polyol having an OH value of about 290 to about 325, or the modified diethylene glycol phthalate polyester polyol having an OH value of about 230 to about 250, from about 20% to about 30% by weight of the Mannich-type polyol having an OH value of about 415 to about 435, from about 6% to about 8% by weight of diethylene glycol, from about 1% to about 3% by weight of water, from about 0.15% to about 2.5% by weight of the cell opener, and from about 20% to about 34% by weight of the diluent.
[0073] In one aspect, the invention relates to a urethane foam made from a reaction mixture comprising (a) a polyol blend of the invention, and (b) an isocyanate, a polyisocyanate, or a mixture thereof. In this embodiment, the isocyanate preferably is 2,4- and/or 2, 4/2, 6-toluene diisocyanate, diphenyl methane 4,4′-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, or a mixture thereof. Also in this embodiment, the polyisocyanate is alternatively a polyphenyl polymethylene polyisocyanate.
[0074] The invention further relates to a method for preparing polyol compositions which is suitable for preparing a urethane foam. This method comprises combining:
(a) from about 38% to about 90% by weight, based on the weight of the composition, of a polyol formulation; (b) from about 0.05% to about 2.0% by weight, based on the weight of the composition, of a cell opening agent; (c) from about 5% to about 45% by weight, based on the weight of the composition, of a diluent; and (d) from about 0.5% to about 5% by weight, based on the weight of the composition, of water.
[0079] The methods of the invention can further include adding the following optional components:
(e) from about 0.25% to about 5% by weight, based on the weight of the composition, of a urethane catalyst; and/or (f) from about 0% to about 1% by weight, based on the weight of the composition, of an acid; and/or (g) from about 0% to about 3% by weight, based on the weight of the composition, of a surfactant.
[0083] In anther embodiment, the invention provides a polyurethane foam comprising from about 0.01% to about 1% by weight of a cell opening agent which is a divalent metal salt of a fatty acid, where the foam has an open-cell content sufficient to resist shrinkage and exhibits less than about 5% shrinkage when stored at about 158° F. and about 100% relative humidity for about 28 days. These foams comprise the reaction product of an aromatic polymeric isocyanate with a polyol blend of the invention.
[0084] Preferably, the polyurethane foam exhibits less than about 3% shrinkage when stored at about −20° F. for 28 days.
[0085] In yet another embodiment, the invention relates to a method for preparing a urethane foam comprising reacting the polyol composition with an isocyanate, a polyisocyanate, or a mixture thereof, to produce the foam. In accordance with this embodiment, the NCO/OH index of the foam is about 85 to about 125. The foam produced in accordance with the embodiments disclosed herein is pourable, and/or is sprayable. Accordingly, the invention also relates to methods of applying spray foams, which are derived from the blends described herein, to various substrates, particularly roofs.
[0000] Polyols
[0086] The polyols suitable for use in the invention are polyester polyols, polyether polyols and Mannich-type polyols. Preferred polyol blends are those that comprise a polyester polyol. In these preferred blends, the polyester polyol can be up to about 100% of the polyol formulation. In other preferred polyol blends, the polyol formulation is a mixture of polyols, e.g., (a) polyester polyol and polyether polyol, (b) polyester polyol and Mannich-type polyol, (c) polyether polyol and Mannich-type polyol, or (d) polyether polyol, polyester polyol, and Mannich-type polyol. Thus, the polyol formulation may be up to about 100% by weight of polyether polyol, i.e., it may be polyester polyol free, or may contain a mixture of polyether and polyester polyols.
[0087] Starting polyol components suitable for use in the polyol blends or mixtures according to the invention include polyesters containing at least two hydroxyl groups, as a rule having a molecular weight of from about 300 to about 10,000, in particular, polyesters containing from 2 to 8 hydroxyl groups, and, in some embodiments of the invention, having a molecular weight of from about 350 to about 700, in other embodiments having a molecular weight of from about 350 to about 600, wherein the acid component of these polyesters comprise at least about 50% by weight in one embodiment, and at least about 70% by weight in another embodiment, of phthalic acid residues.
[0088] These polyesters containing hydroxyl groups include for example, reaction products of polyhydric, such as dihydric and trihydric, alcohols with phthalic acids and other polybasic, such as dibasic, carboxylic acids. Instead of using the free phthalic acids or polycarboxylic acids, the corresponding acid anhydrides or corresponding acid esters of lower alcohols or mixtures thereof may be used for preparing the polyesters. Orthophthalic acids, isophthalic acids and/or terephthalic acids may be used as the phthalic acid. The optional polybasic-carboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and may be substituted, for example, with halogen atoms and/or may be unsaturated. The following are mentioned as examples; succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, trimellitic acid, trimellitic anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, endomethylene tetrahydro phthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids, such as oleic acid, optionally mixed with monomeric fatty acids. Suitable polyhydric alcohols include, for example, ethylene glycol, propylene glycol-(1,2) and -(1,3), diol-(1,8), neopentyl glycol, cyclohexane dimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propane diol, glycerol, trimethylolpropane, hexanetriol-(1,2,6), butane triol-(1,2,4), trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, methylglycoside, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols, dibutylene glycol, and polybutylene glycols. The polyesters may also contain carboxyl end groups. Polyesters of lactones, such as ε-caprolactone, or hydroxycarboxylic acids, such as δ-hydroxycaproic acid, may also be used.
[0089] In one embodiment, polyester polyols for use in the invention comprise the reaction products of (a) phthalic acid compounds, (b) low molecular weight aliphatic diol compounds, (c) and nonionic surfactant compounds. Such polyester polyols are described in U.S. Pat. Nos. 4,644,047 and 4,644,048, each of which is incorporated herein in its entirety.
[0090] Suitable polyols for the invention also include Mannich-type polyols. Mannich-type polyols are prepared by reacting, for example, nonylphenol, formaldehyde, and mono or dialkanolamines or mixtures thereof. This intermediate is then typically reacted with alkylene oxide to produce the final “Mannich Polyol.” The preparation of Mannich-types polyols is also described in U.S. Pat. Nos. 3,297,597; 4,137,265; 4,383,102; 4,247,655; 4,654,376, each of which is incorporated herein in its entirety.
[0091] According to the invention, polyesters containing at least one, generally from 2 to 8, and, in one embodiment of the invention, 3 to 6 hydroxyl groups and having a molecular weight of from about 100 to about 10,000 may be used in the polyol blend. These are prepared, for example, by the polymerization of epoxides, such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, or epichlorohydrin, either on its own for example in the presence of BF 3 , or by chemical addition of these epoxides, optionally as mixtures or successively, to starting components having reactive hydrogen atoms, such as alcohols or amines, for example water, ethylene glycol, propylene glycol-(1,3) or -(1,2), trimethylol propane, 4,4-dihydroxy diphenylpropane aniline, ammonia ethanolamine or ethylene diamine. Sucrose polyethers which have been described, for example in German Auslgeschrift Nos. 1,176,358 and 1,064,938 may also be used according to the invention.
[0092] Among the corresponding polythioethers which may also be used are the condensation products obtained from thiodiglycol on its own and/or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or aminoalcohols should be particularly mentioned. The products obtained are polythio mixed ethers, polythio ether esters or polythio ether ester amides, depending on the co-components.
[0093] Polyhydroxyl compounds already containing urethane or urea groups and modified or unmodified natural polyols, such as castor oil, carbohydrates or starch may also be used. Addition products of alkylene oxides and phenyl/formaldehyde resins or of alkylene oxides and urea/formaldehyde resins are also suitable according to the invention.
[0094] Representatives of these compounds which may be used according to the invention have been described, for example, in High Polymers, Volume XVI, “Polyurethanes, Chemistry and Technology”, by Saunders and Frisch, Interscience Publishers, New York; London, Volume I, 1962, pages 32-42 and pages 44 to 54 and Volume II, 1964, pages 5 and 6 and 198-199, and in Kunststoff-Handbuch, Volume VII, Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, for example, on pages 45 to 71.
[0095] In certain embodiments, the polyol formulation comprises a phthalate polyester-ether polyol. These polyester-ether polyols are the reaction product of a phthalate polyester polyol (“intermediate polyester polyols”), and a polyhydridic polyol. The intermediate phthalate polyester polyol is the reaction product of:
(1) about 2% to about 60% by weight, based on the weight of the polyester polyol, of phthalic anhydride or phthalic acid; and (2) about 40% to about 98% by weight, based on the weight of the polyester polyol, of at least one polyol of the formula:
HO—R 1 —OH
wherein R 1 represents:
(a) alkylene groups of about 2 to about 10 carbon atoms; or (b) —CH 2 —R 2 —CH 2 —
where R 2 represents:
(c) a mixture thereof.
[0101] The R 1 alkylene group may be branched or straight chain, saturated or unsaturated, and when R 2 contains a hydroxyl moiety, such hydroxyl group may be optionally alkoxylated.
[0102] Preferably, the phthalate polyester polyol is of the general formula
wherein R represents:
(a) alkylene groups of about 2 to about 10 carbon atoms; or (b) —CH 2 —R 2 —CH 2 —
wherein R 2 represents:
(c) a mixture thereof.
[0106] Suitable polyhydridic polyols include (i) alkoxylated glycerine, such as propoxylated glycerine, (ii) alkoxylated sucrose, and (iii) alkoxylated glycols, such as diethylene glycol, ethylene glycol, propylene glycol, butylene glycol, and the like, or mixtures of any of these polyhydric alcohols. Typical alkoxylating agents for any of these polyhydric alcohols are ethylene, propylene and/or butylene oxide.
[0107] In a preferred aspect, the polyester and polyhydric alcohol are combined together in the polyol blend and before reacting the blend with the isocyantate “A-side”. In these blends, the polyester polyol and polyhydric alcohols may be present at a variety of suitable ratios. Suitable ratios of polyester polyol to polyhydric alcohol are from about 25:1 to about 1:1. More preferred ranges are from higher ratios of about 20:1 or about 15:1 to lower ratios of about 1.5:1. Even more preferred higher ratios are about 8:1. More preferred lower ratios are about 3:1 or about 2:1.
[0108] The polyester-ether polyols of the invention may be the reaction product of phthalic anhydride (PA), a polyhydroxyl compound, and an alkoxylating agent, e.g., propylene oxide, as shown below:
wherein R is branched or linear, saturated or unsaturated C 2-10 alkyl, cycloalkyl, alkenyl, alkynyl, aromatic, polyoxyethylenic, polyoxypropylenic; wherein R may contain pendant secondary functionality such as hydroxyl, aldehyde, ketone, ether, ester, amide, nitrile, amine, nitro, thiol, sulfonate, sulfate, and/or carboxylic groups. Where pendant secondary hydroxyl functionality is present, such hydroxyl groups may optionally be alkoxylated. In some embodiments of the invention, phthalic anhydride is reacted with a polyol, i.e., a diol such as diethylene glycol to form a polyester polyol.
[0109] Preferred polyester polyols may be made as follows
wherein n=2-10, x=1-500. In accordance with this embodiment, PA polyester polyol intermediates for use in the invention are derived from the condensation of phthalic anhydride and ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol, triethylene glycol, and tetramethylene glycol and mixtures thereof.
[0110] Specific polyester polyols suitable for use in the compositions of the invention include for example phthalic acid diethylene glycol polyester polyols. Suitable phthalic acid diethylene glycol polyester polyols are commercially available from Stepan Company, Northfield, Ill. Representative auxiliary polyols are StepanPol® PS-2002 (a phthalic anhydride diethylene glycol polyester polyol having an OHv of 195 and a functionality of 2), StepanPol® PS-3152 (a phthalic anhydride diethylene glycol polyester polyol having an OHv of 315 and a functionality of 2), StepanPol® PS-4002 (a phthalic anhydride diethylene glycol polyester polyol having an OHv of 400 and a functionality of 2), and StepanPol PS-2502A (an aromatic polyester polyol having an OHv of 245) and mixtures thereof. In the invention, by OH value (OHv) is meant hydroxyl value, a quantitative measure of the concentration of hydroxyl groups, usually stated as mg KOH/g, i.e., the number of milligrams of potassium hydroxide equivalent to the hydroxyl groups in 1 g of substance. By functionality is meant the number of reactive groups, e.g., hydroxyl groups, in a chemical molecule.
[0111] Other auxiliary polyester polyols, i.e. non-phthalic anhydride-based polyester polyols, include for example, polyester polyols derived from the condensation of caprolactone and a poly alcohol, and terate polyester polyols (e.g. Terate-203; a diethylene glycol terephthalate polyester polyol having an OHv of 315 and a functionality of 2.3; commercially available from Kosa). Specific auxiliary polyether polyols suitable for use in the methods and compositions of the invention include for example the condensation products of propylene glycol/propylene oxide, trimethylolpropane/ethylene oxide/propylene oxide, trimethylolpropane/propylene oxide, sucrose/propylene glycol/propylene oxide, alkylamine/propylene oxide, and glycerin/propylene oxide, and mixtures thereof.
[0000] Polyisocyanate
[0112] The polyisocyanate starting components used according to the invention include aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as those described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie 562: 75-136. Examples include ethylene diisocyanate; tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and 1,4-diisocyanate and mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (German Ausiegeschrift No. 1,202,785, U.S. Pat. No. 3,401,190); hexahydrotolylene-2,4- and 2,6-diisocyanate and mixtures of these isomers; hexahydrophenylene-1,3- and/or -1,4-diisocyanate; perhydrodiphenylmethane-2,4′- and/or 4,4′-diisocyanate; phenylene-1,3- and -1,4-diisocyanate; tolylene-2,4- and -2,6-diisocyanate and mixtures of these isomers; diphenylmethane-2,4′- and/or -4,4′-diisocyanate; naphthylene-1,5-diisocyanate; triphenylmethane-4,4′,4″-triisocyanate; polyphenylpolymethylene polyisocyanate which may be obtained by aniline/formaldehyde condensation followed by phosgenation and which have been described, for example, in British Pat. Nos. 874,430 and 848,671; m- and p-isocyanatophenyl sulphonyl isocyanate according to U.S. Pat. No. 3,454,606; perchlorinated aryl polyisocyanate as described, for example, in U.S. Pat. No. 3,277,138; polyisocyanate, containing carbodiimide groups as described in U.S. Pat. No. 3,152,162; the diisocyanates described in U.S. Pat. No. 3,492,330; polyisocyanates containing allophanate groups as described, for example, in British Pat. No. 994,890, Belgian Pat. No. 761,626 and Published Dutch Patent application No. 7,102,524; polyisocyanates containing isocyanurate groups as described, for example, in U.S. Pat. No. 3,001,973, in German Pat. Nos. 1,022,789; 1,222,067 and 1,027,394 and in German Offenlegungsschriften Nos. 1,929,034 and 2,004,048; polyisocyanates containing urethane groups as described, for example, in Belgian Pat. No. 752,261 or in U.S. Pat. No. 3,394,164; polyisocyanates containing acrylated urea groups according to German Pat. No. 1,230,778; polyisocyanates containing biuret groups as described, for example, in U.S. Pat. Nos. 3,124,605 and 3,201,372; and in British Pat. No. 889,050; polyisocyanates prepared by telomerization reactions as described, for example in U.S. Pat. No. 3,654,016; polyisocyanates containing ester groups as mentioned, for example, in British Pat. Nos. 965,474 and 1,072,956, in U.S. Pat. No. 3,567,763 and in German Pat. No. 1,231,688; reaction product of the above-mentioned isocyanates with acetals according to German Pat. No. 1,072,385; and, polyisocyanates containing polymeric fatty acid groups as described in U.S. Pat. No. 3,455,883. Also suitable for use in the present invention are isocyanate terminated pre-polymers using hydroxy containing reactants of any of the foregoing.
[0113] The distillation residues obtained from the commercial production of isocyanates and which still contain isocyanate groups may also be used, optionally dissolved in one or more of the above-mentioned polyisocyanates. Mixtures of the above-mentioned polyisocyanates may also be used.
[0114] In some embodiments of the invention, the polyisocyanates which are readily available are used, for example, toluene-2,4- and -2,6-diisocyanate and mixtures of these isomers (“TDI”); polyphenyl polymethylene polyisocyanates which may be obtained by aniline/formaldehyde condensation followed by phosgenation (“crude MDI”); and, polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups (“modified polyisocyanates”), and mixtures thereof.
[0115] In some embodiments of the invention, polyisocyanates are 2,4- and/or 2,4/2,6-toluene diisocyanate, diphenyl methane 4,4′-diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, and mixtures thereof.
[0116] In one embodiment of the invention, the polyisocyanate is methylene bis(phenyl isocyanate).
[0117] Suitable polyisocyanurates useful in the invention also include, as is well known to those skilled in the art, the cyclotrimerization product of any of the aforementioned polyisocyanates.
[0118] In a typical rigid spray-in-place application, the polyisocyanate mixture is reacted with a polyol blend at a ratio of about 0.9 to about 1.1:1 (v/v) ratio. The reaction can be achieved using a spray gun apparatus or other suitable mixing devices. Alternatively, the reaction can be achieved using a high pressure impingement machine provided with a nozzle capable of filling a void volume. As another alternative, the reaction may be achieved using a low pressure static mixing machine equipped with a nozzle to fill a void volume.
[0000] Acid Component
[0119] Some embodiments of the polyol formulation used in the invention comprises a polyester polyol and an acid. The acid is used in an amount capable of maintaining the dispersed polyol blend as a dispersion for a period of time sufficient to allow for the production of a polyurethane foam and preferably a foam having a uniform open celled content. The foam is made by reacting the polyol blend with an aromatic polyisocyanate.
[0120] The amount of acid optionally present is generally up to about 5% by weight of the polyol blend. In one embodiment, the amount of the acid is from about 0.05 to about 5% by weight of the polyol blend. In another embodiment, the amount of acid is from about 0.1% to about 1%.
[0121] Suitable acids are generally Bronsted acids, i.e., substances that can donate protons. In one embodiment of the invention, the acids are organic acids. In another embodiment, the acids are various alkanoic or alkenoic acids of the formula RCO 2 H, where R is hydrogen, a straight or branched chain alkyl group having from about 1 to about 12 carbon atoms, or a straight or branched chain alkenyl group having from about 2 to about 12 carbon atoms. Representative acids include, for example, formic, acetic, isobutyric, and 2-ethylhexanoic acids. In a preferred embodiment, the acid is 2-ethylhexanoic acid.
[0000] Blowing Agent
[0122] According to the invention, the reaction of the dispersed polyol blend as set forth above with a polyisocyanate provides an open cell rigid polyurethane foam as desired. In a preferred embodiment of the invention, water is used as a primary blowing agent in the dispersed polyol blend. In this embodiment, the amount of water as a blowing agent is about 0.5% to about 5% and can be about 1% to about 4% and further can be about 1.5% to about 2.5%, based on the weight of the composition. When the amount of water is insufficient, a low density foam may not be produced.
[0123] Although the preparation of the foam is typically carried out using a dispersed polyol blend having water as a blowing agent, in another embodiment, the blowing agent comprises a secondary blowing agent, either alone, or preferably in combination with the primary blowing agent, water. Suitable secondary blowing agents include both CFC and non-CFC blowing agents. Secondary blowing agents are typically liquids having low boiling points.
[0124] Suitable secondary blowing agents include, but are not limited to, halogenated hydrocarbons such as, for example, 2,2-dichloro-2-fluoroethane (HCFC-141b), water, and hydrocarbons such as pentane, hydrofluorocarbons (HFCs) and perfluorocarbons for example. Other suitable organic blowing agents include, for example, acetone, ethyl acetate, halogenated alkanes, such as methylene chloride, chloroform, ethylidene chloride, yinylidene chloride, and also butane, pentane, hexane, heptane or diethylether. The effect of a blowing agent may also be obtained by adding compounds which decompose at temperatures above room temperature to liberate gases, such as nitrogen, for example, azo compounds, such as azoisobutyric acid nitrile. Other examples of blowing agents and details about the use of blowing agents may be found in Kunststoff-Handbuch, Volume VII, published by Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, for example, on pages 108 and 109, 453 to 455 and 507-510.
[0125] Further examples of suitable optional blowing agents are described in U.S. Pat. No. 5,346,928, which is incorporated herein in its entirety.
[0000] Cell Opening Agent
[0126] Cell opening agents suitable for use in the invention include known powdered divalent metal salts of long chain fatty acids having from about 1 to about 22 carbon atoms. Examples of such agents are divalent metal salts of stearic or myristic acid, such as calcium stearate, magnesium stearate, strontium stearate, zinc stearate or calcium myristate, as disclosed in Japanese Patent Application Laid-open No. 61-153480. The cell opening agent is used in an amount of about 0.01% to about 2.0% based on the weight of the composition. The cell opening agent is typically capable of forming a stable dispersion with the polyester polyol.
[0127] In preferred embodiments of the invention, cell opening agents having melting or softening points of from about 100 to about 180° C. are used. In one embodiment, dispersed polyol blends comprise from about 0.05% to about 1.5% cell opening agent based on the weight of the composition. In another embodiment, dispersed polyol blends comprise from about 0.1% to about 0.8% cell opening agent based on the weight of the composition.
[0000] Isocyanate Polymerization Catalyst
[0128] Compounds which readily initiate a polymerization reaction of the NCO-groups at temperatures as low as room temperature are used as the catalyst system for polymerization. Compounds of this type are described, for example, in French Pat. No. 1,441,565, Belgian Pat. Nos. 723,153 and 723,152 and German Pat. No. 1,112,285.
[0129] Such catalyst systems are, in particular, mononuclear or polynuclear Mannich bases of condensable phenols, oxo-compounds and secondary amines which are optionally substituted with alkyl groups, aryl groups or aralkyl groups, and, in one embodiment of the invention, those in which formaldehyde is used as the oxo-compound and dimethylamine as the secondary amine.
[0130] According to the invention, the catalysts that may be used as the catalyst for the polyurethane reaction include, for example, tertiary amines, such as triethylamine, tributylamine, N-methyl morpholine, N-ethyl-morpholine, N-cocomorpholine, N,N,N′,N′-tetramethylethylenediamine, 1,4-diaza-bicyclo-(2,2,2)-octane, N-methyl-N′-dimethyl aminoethyl-piperazine, N,N-dimethylbenzylamine, bis-(N,N-diethylaminoethyl)-adipate, N,N diethylbenzylamine, pentamethyldiethylenetriamine, N,N dimethylcyclohexylamine, N,N,N′,N′-tetramethyl-1,3-butane diamine, N,N-dimethyl-.beta.-phenylethylamine, 1,2-dimethylimidazole and 2-methylimidazole and Curithane 52 (available from Air Products).
[0131] Tertiary amines containing isocyanate-reactive hydrogen atoms used as catalysts include, for example, triethanolamine, triisopropanolamine, N-methyl-diethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine and the reaction products thereof with alkylene oxides, such as propylene oxide and/or ethylene oxide.
[0132] Silaamines having carbon-silicon bonds as described, for example, in German Pat. No. 1,229,290 (corresponding to U.S. Pat. No. 3,620,984) may also be used as catalysts, for example, 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyl-tetramethyl-disiloxane.
[0133] The catalysts used may also be basic nitrogen compounds, such as tetralkylammonium hydroxides, alkali metal hydroxides, such as sodium hydroxide, alkali metal phenolates, such as sodium-phenolate, or alkali metal alcoholates, such as sodium methylate. Hexahydrotriazines may also be used as catalysts. Typically, the amine catalyst is employed in excess of the required acid. However, any of the catalysts derived from amines may be used in the invention as the corresponding ammonium salts or quaternary ammonium salts. Thus, in the practice of the invention, catalysts derived from amines may be present in the polyol blends as their corresponding acid blocked form. Accordingly, in certain embodiments, such a catalyst and the requisite acid may be simultaneously added conveniently as the amine salt of the acid.
[0134] According to the invention, organic metal compounds, in particular organic tin compounds, may also be used as catalysts.
[0135] Suitable organic tin compounds are, in some embodiments of the invention, tin(II)-salts of carboxylic acids, such as tin(II)-acetate, tin(II)-octoate, tin(II)-ethylhexoate and tin(II)-laurate, and the tin(IV)-compounds, for example dibutyl tin oxide, dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate or dioctyl tin diacetate.
[0136] Suitable organo lead compounds for use as primary catalysts include lead naphthanate and lead octoate.
[0137] All of the above-mentioned catalysts may be used as mixtures.
[0138] Further representatives of catalysts which may be used according to the invention, as well as details on the mode of operation of the catalyst are described in Kunststoff-Handbuch, Volume III, published by Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, for example, on pages 96 to 102.
[0139] Other catalysts include N,N-dimethyl-cyclohexylamine, lead naphthanate, tin octanoate and tin dilaurate.
[0140] Still other catalysts suitable for use in the invention include amino acid salt catalysts, e.g., those derived from sarcosine. Suitable amino salts derived from sarcosine include various N-(2-hydroxy or 2-alkoxy-5-alkylphenyl)alkyl sarcosinates. The alkyl groups are independently C 1 -C 18 alkyl groups and the alkoxy groups are C 1 -C 6 alkoxy groups. Of course, each of the sarcosinate derivatives includes a suitable counterion, such as, for example, sodium, potassium, magnesium, lithium, etc. In one embodiment of the invention, the amino acid salt is sodium N-(2-hydroxy-5-nonylphenyl)methyl sarcosinate. Each of the amino acid derivatives may be prepared according to the procedures set forth in U.S. Pat. No. 3,903,018. Representative amino acid salt catalysts are, for example, sodium N-(2-hydroxy-5-methylphenyl)methyl sarcosinate; sodium N-(2-hydroxy-5-ethylphenyl)methyl sarcosinate; sodium N-(2-hydroxy-5-butylphenyl)methyl sarcosinate; sodium N-(2-hydroxy-5 heptylphenyl)methyl sarcosinate; sodium N-(2-hydroxy-5-nonylphenyl)methyl sarcosinate; sodium N-(2-hydroxy-5-dodecylphenyl)methyl sarcosinate; potassium N-(2-hydroxy-5-nonylphenyl)methyl sarcosinate; lithium N-(2-hydroxy-5-nonylphenyl)methyl sarcosinate; and mixtures thereof. Other suitable catalysts include, for example, the disodium salt of 2,6-bis-(N-carboxymethyl-N-methylaminomethyl)-p-ethylphenol and the disodium salt of 2,6-bis-(N-carboxymethyl-N methlaminomethyl)-p-nonylphenol; and mixtures thereof.
[0141] The catalysts are generally used in a quantity of from about 0.001% to about 10% by weight, based on the quantity of the polyesters used according to the invention.
[0000] Diluents
[0142] As used herein, the terms diluent or diluents include within their scope plasticizer materials. Diluents suitable for use in the invention include those described in U.S. Pat. Nos. 3,773,697, 5,929,153, 3,929,700 and 3,936,410, the disclosures of each of which are incorporated herein by reference in their entirety. Suitable diluents include
(a) phthalic plasticizers such as di-n-butyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, diisooctyl phthalate, octyldecyl phthalate, butylbenzyl phthalate and di-2-ethylhexyl isophthalate, aliphatic ester plasticizers such as di-2-ethylhexyl adipate, di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate and di-2-ethylhexyl sebacate, trimellitic plasticizers such as trioctyl trimellitate and tridecyl trimellitate, phosphoric ester plasticizers such as tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyldiphenyl phosphate and tricresyl phosphate, epoxy plasticizers such as epoxy soybean oil, polyester-based high-molecular plasticizers, and the like. Other diluents suitable for use in the invention include, for example, (b) propylene carbonate, (c) alkyl esters of monobasic acids where the alkyl group is straight or branched chain alkyl having from 1-20 carbon atoms, such as 2-ethylhexylbenzoate, methyl 2-ethylhexanoate and the like (hereinafter “monobasic esters”), (d) dialkyl esters of dibasic acids where each alkyl group is independently a straight or branched chain alkyl having from 1-20 carbon atoms (hereinafter “dibasic esters”), (e) diacid esters of α, ω-diols where the acid is a straight or branched chain alkanoic acid having from 1-6 carbon atoms and the diol is a straight or branched chain aliphatic diol (hereinafter “diol esters”), (f) mono- and di(C 1 -C 6 )alkyl ethers of alkylene and polyalkylene glycols (hereinafter “glycol ethers”), (g) nonyl phenols alkoxylated with from 1 to about 50 moles of an alkoxylating agent or mixture of alkoxylating agents having from 1-6 carbon atoms, preferably about 7 to about 12 moles of an alkoxylating agent having from 2-4 carbon atoms (hereinafter “alkoxylated nonyl phenols”), e.g., Makon 10 (available from Stepan Company), (h) tris-isopropylchlorophosphate, and (i) mixtures of any of (a)-(h).
[0152] Representative glycol ethers include monomethyl diethylene glycol, monoethyl dipropylene glycol, and monomethyl tripropylene glycol.
[0153] Suitable diesters of dibasic acids for use in the invention include, for example, dimethyl adipate, dialkyl adipate, dimethyl glutarate, dimethyl succinate, H 3 CO(CO) (CH 2 ) n (CO)OCH 3 , wherein n is an integer between 1 and 10, and di(2-ethylhexyl) adipate. A preferred aspect of the invention employs a mixture of dibasic esters. A particularly preferred mixture contains about 20% by weight of dimethyl succinate, about 21% by weight of dimethyl adipate and about 59% by weight of dimethyl glutarate.
[0154] A representative diacid ester of an α, ω-diol is 2,2,4-trimethyl-1,3-pentanediol diisobutyrate.
[0155] Preferred diluents include propylene carbonate, a dibasic ester mixture, alkoxylated nonyl phenols, more preferably Makon 10, tris-isopropylchlorophosphate, and glycol ethers, more preferably monomethyl dipropylene glycol and monomethyl tripropylene glycol.
[0156] In preferred embodiments of the invention, the diluents are of low viscosity (less than approximately 50 centipoise at 25° C.) and act as plasticizers within the polymer.
[0000] Surfactants and Additives
[0157] Surfactants suitable for use in the invention include non-ionic surfactants and amphoteric surfactants such as those disclosed in U.S. Pat. No. 6,017,860, the disclosure of which is incorporated herein by reference in its entirety. Suitable nonionic surfactants in accordance with the invention are also generally disclosed at column, 13 line 14 through column 16, line 6 of U.S. Pat. No. 3,929,678, the disclosure of which is incorporated herein by reference in its entirety. Generally, the nonionic surfactant is selected from the group comprising polyoxyethyleneated alkylphenols, polyoxyethyleneated straight chain alcohols, polyoxyethyleneated branched chain alcohols, polyoxyethyleneated polyoxypropylene glycols, polyoxyethyleneated mercaptans, fatty acid esters, glyceryl fatty acid esters, polyglyceryl fatty acid esters, propylene glycol esters, sorbitol esters, polyoxyethyleneated sorbitol esters, polyoxyethylene glycol esters, polyoxyethyleneated fatty acid esters, primary alkanolamides, ethoxylated primary alkanolamides, secondary alkanolamides, ethoxylated secondary alkanolamides, tertiary acetylenic glycols, polyoxyethyleneated silicones, N-alkylpyrrolidones, alkylpolyglycosides, alkylpolylsaccharides, EO-PO blockpolymers, polyhydroxy fatty acid amides, amine oxides and mixtures thereof.
[0158] Suitable amphoteric surfactants are selected from the group comprising alkyl glycinates, propionates, imidazolines, amphoalkylsulfonates sold as “Miranol” by Rhone Poulenc, N-alkylaminopropionic acids, N-alkyliminodipropionic acids, imidazoline carboxylates, N-alkylbetaines, amido propyl betaines, sarcosinates, cocoamphocarboxyglycinates, amine oxides, sulfobetaines, sultaines and mixtures thereof.
[0159] Additional suitable amphoteric surfactants include cocoamphoglycinate, cocoamphocarboxyglycinate, lauramphocarboxyglycinate, cocoamphopropionate, lauramphopropionate, stearamphoglycinate, cocoamphocarboxypropionate, tallowamphopropionate, tallowamphoglycinate, oleoamphoglycinate, caproamphoglycinate, caprylamphopropionate, caprylamphocarboxyglycinate, cocoyl imidazoline, lauryl imidazoline, stearyl imidazoline, behenyl imidazoline, behenylhydroxyethyl imidazoline, caprylamphopropylsulfonate, cocoamphopropylsulfonate, stearamphopropylsolfonate, oleoamphopropylsulfonate and the like.
[0160] Other surfactants suitable for use in the invention include, but are not limited to, polyether siloxanes or alkoxylated polysiloxanes such as Niax L-5440 (available from OSI Specialties, Crompton), Tegostab B-8404 (available from Goldschmidt), Dabco DC-5357 (available from Air Products), and mixtures thereof.
[0161] Surface-active additives and foam stabilizers, may also be used in the invention. Suitable materials include, for example, the sodium salts of ricinoleic sulphonates, or salts of fatty acids and amines, such as oleic acid diethylamine or stearic acid diethanolamine. Alkali metal or ammonium salts of sulphonic acids, such as dodecyl benzene sulphonic acid or dinaphthylmethane disulphonic acid, or of fatty acids, such as ricinoleic acid, or of polymeric fatty acids may also be used as surface-active additives.
[0162] The foam stabilizers used are preferably polyether siloxanes, especially those which are water-soluble. These compounds generally have a polydimethyl siloxane group attached to a copolymer of ethylene oxide and propylene oxide. Foam stabilizers of this type have been described, for example, in U.S. Pat. Nos. 2,834,748; 2,917,480 and 3,629,308.
[0163] According to the invention, it is also possible to use known cell regulators such as paraffins or fatty alcohols or dimethyl polysiloxanes, as well as pigments or dyes and known flame-proofing agents, for example, trischloroethylphosphate, tricresylphosphate or ammonium phosphate or polyphosphate, also stabilizers against ageing and weathering, plasticizers, fungistatic and bacteriostatic substances and fillers, such as barium sulphate, kieslguhr, carbon black or whiting.
[0164] Other examples of surface-active additives, foam stabilizers, cell regulators, reaction retarders, stabilizers, flame-proofing substances, plasticizers, dyes, fillers and fungistatic and bacteriostatic substances which may also be used according to the invention and details concerning the use and action of these additives may be found in Kunststoff-Handbuch, Volume-Val, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, for example on pages 103 and 113.
[0000] Emulsifiers
[0165] The polyol blends may optionally include emulsifiers to prolong the stability and shelf-life of the dispersed polyol blends. Examples of suitable emulsifiers include sodium N-(2-hydroxy-5-nonylphenyl)methyl sarcosinate and soybean oil.
[0166] All documents, e.g., patents and journal articles, cited above or below are hereby incorporated by reference in their entirety.
[0167] One skilled in the art will recognize that modifications may be made in the invention without deviating from the spirit or scope of the invention. The invention is illustrated further by the following examples which are not to be construed as limiting the invention or scope of the specific procedures described herein.
[0168] The following is a description of certain materials used in the following examples:
Stepanpol PS-2352: a low functional (functionality of 2) modified diethylene glycol phthalate polyester polyol having an OH value of about 220 to about 250, sold by Stepan Company, Northfield, Ill. Stepanpol PS-3152: a low functional (functionality of 2) diethylene glycol phthalate polyester polyol having an OH value of about 290 to about 325, sold by Stepan Company, Northfield, Ill. Stepanpol® PS-2502-A: a low functional (functionality of 2) modified diethylene glycol phthalate polyester polyol having an OH value of about 230 to about 250, sold by Stepan Company, Northfield, Ill. Dabco® DC5357: a polysiloxane surfactant composed of dimethyl, methyl (polyethylene oxide) siloxane copolymer, sold by Air Products Corporation of Allentown, Pa. Tegostab B8404: a polysiloxane surfactant composed of dimethyl, methyl (polyethylene oxide) siloxanecopolymer, sold by Goldschmidt. Niax® A-1: a catalyst which contains about 70% bis(2-dimethylaminoethyl) ether in 30% dipropylene glycol, sold by OSI Specialty Chemical. Mondur MR®: polymethylene polyphenyl isocyanate having an isocyanate content of about 31.5%, commercially available from Bayer, Pittsburgh, Pa. Thanol R-360: an alkoxylated sucrose glycerin polyether polyol having an OH value of about 345 to about 375, sold by Eastman. Polycat 8: Dimethylcyclohexylamine catalyst, sold by Air Products. Jeffeat ZR-70: a catalyst containing 2-(2-(dimethylamino)ethoxy]ethanol, sold by Huntsman. Pluracol P-975: a high functional alkoxylated sucrose diol having an OH value of approximately 380-420, sold by BASF. Voranol-270: a low functional alkoxylated glycerin having an OH value of 230-250, sold by Dow Chemical. Voranol-470X: a Mannich-type polyol having an OH value of 460-480, sold by Dow Chemical. Markol RB 216: a Mannich-type polyol having an OH value of 470-490, sold by Quimica Pumex. Silpol SIP-425LV: a Mannich-type polyol having an OH value of 415-435, sold by Siltech Corp. Carbowax 400: polyethylene glycol of approximately 400 MW sold by Union Carbide. Makon 10: nonyl phenol ethoxylated with an average of 10 ethylene oxide units sold by Stepan Company. Terate-203: a diethylene glycol terephthalate polyester polyol having an OH value of 300-330, sold by Kosa. Surfactant L-5440: an alkoxylated polysiloxane surfactant sold by Crompton OSI. Curithane 52: an isocyanate polymerization catalyst available from Air Products.
GENERAL EXPERIMENTAL
[0189] Amounts of components in the below examples are percentages by weight of the polyol (resin) blend unless indicated otherwise. The individual resin components are added and mixed until a stable homogeneous polyol dispersion is obtained.
[0190] The polyol blends set forth below are prepared according to the invention and reacted by hand mixing and/or spraying with a polyisocyanate (Mondur MR®). The hand mixed foams are reacted in an amount of 150 g of total material at an isocyanate/resin weight ratio of 52/48 (approximately 1:1 isocyanate/resin ratio by volume). Unless otherwise indicated, the isocyanate and resin components are conditioned to 77° F. prior to mixing. The isocyanate is pre-weighted in a 32 ounce No. 2 cup. The desired quantity of resin component is then added to the isocyanate and the two are mixed vigorously for 3 seconds using a double Conn mix blade rotating at approximately 3500 rpm. The foam is allowed to rise and cure in the cup used for mixing. The properties of the hand mix foams are indicated below. Machine sprayed foams utilize either a Gusmer machine or GlasCraft machine with parameters as indicated by the particular examples.
Example 1
[0191]
Phthalate Polyester (Stepanpol PS-3152)
37.26%
Terate Polyester (Terate-203)
14.90%
Propoxylated Glycerine (Voranol-270)
22.35%
Surfactant (L-5440)
1.49%
Cell Opener (Calcium Stearate)
0.33%
Amine-Catalysts*
5.23%
Lead Catalyst (30% Pb Naphthanate)
0.22%
2-Ethylhexanoic Acid
0.37%
Diluents**
14.90%
Water
2.94%
*Amine catalysts: Polycat 8 = 2.24%; Dimethylethanolamine = 2.24%;
Curithane 52 = 0.75%..
**Diluents: tris-isopropylchlorophosphate
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
4
sec.
Tack Free Time
11
sec.
Cup Density
2.49
pcf
Resin Viscosity (77° F.)
580
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Dim. Stability (100° F./
−0.82%
95% R.H., 28 day, ASTM D-2126)
Water Absorption (28 day weight gain)
1.75%
Water Vapor Permeability
2.69
(with surface skin, ASTM E-96)
perm in. (permeability X inch)
Water Vapor Permeability
4.59
perm in.
(without surface skin, ASTM E-96)
Example 2
[0192]
Phthalate Polyester (Stepanpol PS-3152)
37.02%
Terrate Polyester (Terate-203)
14.81%
Propoxylated Glycerine (Voranol-270)
22.21%
Surfactant (L-5440)
2.04%
Cell Opener (Calcium Stearate)
0.30%
Amine Catalysts*
5.18%
Lead Catalyst (30% Pb Naphthanate)
0.22%
2-Ethylhexanoic Acid
0.37%
Diluents**
14.81%
Water
3.04%
*Amine catalysts: Polycat 8 = 2.22%; Dimethylethanolamine = 2.22%;
Curithane 52 = 0.74%.
**Diluents: tris-isopropylchlorophosphate.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
5
sec.
Tack Free Time
12
sec.
Cup Density
2.53
pcf
Resin Viscosity (77° F.)
550
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Density (with passline, ASTM D-1622)
2.76
pcf
Density (no passline, ASTM D-1622)
2.19
pcf
Compressive Strength (with passline, ASTM D-1621)
26.9
psi
Compressive Strength (no passline, ASTM D-1621)
22.8
psi
Shear Strength (with passline, ASTM C-273)
30.2
psi
Shear Strength (no passline, ASTM C-273)
26.6
psi
Tensile Strength (with passline, ASTM D-1623)
38.8
psi
Tensile Strength (no passline, ASTM D-1623)
54.6
psi
Friability (with passline, % wt. loss, ASTM C-421)
0.21%
Friability (no passline, % wt. loss, ASTM C-421)
0.45%
Dim. Stab. (with passline, −20° F., 28 day, ASTM D-2126)
−0.01%
Dim. Stab. (with passline, 158° F., 28 day, ASTM D-2126)
−0.36%
Dim. Stab. (w/passline, 100° F./95% R.H., ASTM D-2126)
0.91%
Example 3
[0193]
Phthalate Polyester (Stepanpol PS-3152)
46.11%
Propoxylated Sucrose (Pluracol P-975)
23.05%
Surfactant (L-5440)
2.11%
Cell Opener (Calcium Stearate)
0.21%
Amine Catalysts*
5.77%
Lead Catalyst (30% Pb Naphthanate)
0.15%
2-Ethylhexanoic Acid
0.38%
Diluents**
19.21%
Water
3.01%
*Amine catalysts: Polycat 8 = 2.50%; Dimethylethanolamine = 2.50%;
Curithane 52 = 0.77%.
**Diluents: tris-isopropylchlorophosphate = 1.53%; Makon 10 = 7.68%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
5
sec.
Tack Free Time
12
sec.
Cup Density
2.56
pcf
Resin Viscosity (77° F.)
680
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Density (with passline, ASTM D-1622)
2.64
pcf
Density (no passline, ASTM D-1622)
2.25
pcf
Compressive Strength (with passline, ASTM D-1621)
30.3
psi
Compressive Strength (no passline, ASTM D-1621)
17.2
psi
Shear Strength (with passline, ASTM C-273)
22.3
psi
Shear Strength (no passline, ASTM C-273)
20.8
psi
Tensile Strength (with passline, ASTM D-1623)
42.7
psi
Tensile Strength (no passline, ASTM D-1623)
36.6
psi
Example 4
[0194]
Phthalate Polyester (Stepanpol PS-3152)
45.27%
Mannich Polyol (Voranol 470X)
20.89%
Diethylene Glycol
3.48%
Surfactant (L-5440)
2.09%
Cell Opener (Calcium Stearate)
0.35%
Amine Catalysts*
3.55%
Diluents**
21.58%
Water
2.79%
*Amine catalysts: Polycat 8 = 1.25%; Dimethylethanolamine = 1.95%;
Curithane 52 = 0.35%.
**Diluents: tris-isopropylchlorophosphate = 14.62%; Makon 10 = 6.96%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
6
sec.
Tack Free Time
13
sec.
Cup Density
2.81
pcf
Resin Viscosity (77° F.)
600
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Shear Strength (with passline, ASTM C-273)
32.7
psi
Shear Strength (no passline, ASTM C-273)
46.6
psi
Tensile Strength (with passline, ASTM D-1623)
64.7
psi
Tensile Strength (no passline, ASTM D-1623)
99.2
psi
Friability (with passline, % wt. loss, ASTM C-421)
0.61%
Friability (no passline, % wt. loss, ASTM C-421)
1.35%
Dim. Stab. (with passline, −20° F., 28 day, ASTM D-2126)
0.20%
Dim. Stab. (no passline, −20° F., 28 day, ASTM D-2126)
0.20%
Dim. Stab. (with passline, 158° F., 28 day, ASTM D-2126)
1.12%
Dim. Stab. (no passline, 158° F., 28 day, ASTM D-2126)
−0.91%
Dim. Stab. (w/passline, 100° F./95% R.H., ASTM D-2126)
3.37%
Dim. Stab. (no passline, 100° F./
−0.05%
95% R.H., ASTM D-2126)
Dim. Stab. (w/passline, 158° F./95% R.H., ASTM D-2126)
0.45%
Dim. Stab. (no passline, 158° F./
−2.60%
95% R.H., ASTM D-2126)
Water Absorption (Gusmer H-2, GX-7, 800 psi, D-2842)
2.56%
Water Absorption (Gus. H-2000, GX-7, 1500 psi, D-2842)
0.08%
Example 5
[0195]
Phthalate Polyester (Stepanpol PS-3152)
36.93%
Mannich Polyol (Voranol 470X)
26.87%
Diethylene Glycol
6.72%
Surfactant (L-5440)
2.02%
Cell Opener (Calcium Stearate)
0.32%
Amine Catalysts*
3.77%
Diluents**
20.83%
Water
2.54%
*Amine catalysts: Polycat 8 = 1.21%; Dimethylethanolamine = 1.88%;
Curithane 52 = 0.34%; Niax A-1 = 0.34%.
**Diluents: tris-isopropylchlorophosphate = 14.11%; Makon 10 = 6.72%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
5
sec.
Tack Free Time
12
sec.
Cup Density
2.94
pcf
Resin Viscosity (77° F.)
550
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Density (with passline, ASTM D-1622)
2.74
pcf
Compressive Strength (with passline, ASTM D-1621)
34.7
psi
Shear Strength (with passline, ASTM C-273)
38.1
psi
Tensile Strength (with passline, ASTM D-1623)
65.6
psi
Friability (with passline, % wt. loss, ASTM C-421)
0.33%
Dim. Stab. (with passline, −20° F., 28 day,
−0.44%
ASTM D-2126)
Dim. Stab. (with passline, 158° F., 28 day,
−1.49%
ASTM D-2126)
Dim. Stab. (w/passline, 158° F./95% R.H.,
−3.13%
ASTM D-2126)
Water Vapor Permeability (with passline, ASTM E-96)
2.01
perm in.
Machine Sprayed Prop.
(Gusmer H-2000; GX-7 Gun; 130° F. Temps.; 1500 psi Pressures)
Density (with passline, ASTM D-1622)
3.18
pcf
Density (no passline, ASTM D-1622)
2.93
pcf
Compressive Strength (with passline, ASTM D-1621)
41.3
psi
Compressive Strength (no passline, ASTM D-1621)
40.0
psi
Water Vapor Permeability (with passline, ASTM E-96)
1.23
perm in.
Example 6
[0196]
Phthalate Polyester (Stepanpol PS-3152)
42.54%
Mannich Polyol (Markol RB 216)
15.47%
Diethylene Glycol
5.80%
Surfactant (L-5440)
1.90%
Cell Opener (Calcium Stearate)
0.48%
Amine Catalysts*
3.46%
Diluents**
27.85%
Water
2.49%
*Amine catalysts: Polycat 8 = 1.06%; Dimethylethanolamine = 1.66%;
Curithane 52 = 0.39%; Niax A-i = 0.35%.
**Diluents: tris-isopropylchlorophosphate = 16.25%; Makon 10 =
11.60%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
5
sec.
Tack Free Time
11
sec.
Cup Density
2.99
pcf
Resin Viscosity {77° F.)
520
cps
Machine Sprayed Properties
(Gusmer H-2; GX-7 Gun; 120° F. Temps.; 800 psi Pressures)
Density (with passline, ASTM D-1622)
3.82
pcf
Density (no passline, ASTM D-1622)
3.22
pcf
Compressive Strength (with passline, ASTM D-1621)
61.8
psi
Compressive Strength (no passline, ASTM D-1621)
52.1
psi
Shear Strength (with passline, ASTM C-273)
42.4
psi
Shear Strength (no passline, ASTM C-273)
52.3
psi
Tensile Strength (with passline, ASTM D-1623)
68.9
psi
Tensile Strength (no passline, ASTM D-1623)
72.8
psi
Friability (with passline, % wt. loss, ASTM C-421)
0.31%
Friability (no passline, % wt. loss, ASTM C-421)
0.34%
Water Absorption (no passline, ASTM D-2842)
0.58%
Example 7
[0197]
Phthalate Polyester (Stepanpol PS-3152)
32.47%
Mannich Polyol (Silpol SIP-425LV)
21.65%
Diethylene Glycol
7.22%
Surfactant (L-5440)
1.77%
Cell Opener (Calcium Stearate)
0.39%
Amine Catalysts*
3.36%
Diluents**
30.97%
Water
2.16%
*Amine catalysts: Polycat 8 = 1.04%; Dimethylethanolamine = 1.63%;
Curithane 52 = 0.36%; Niax A-1 = 0.33%.
**Diluents: tris-isopropylchlorophosphate = 15.15%; Makon 10 =
10.82%; Propylene Carbonate = 5.00%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
5
sec.
Tack Free Time
13
sec.
Cup Density
3.08
pcf
Resin Viscosity (77° F.)
320
cps
Machine Sprayed Properties
(GlasCraft; Probler Gun; 120° F. Temps.; 1500 psi Pressures)
Density (with passline, ASTM D-1622)
3.14
pcf
Compressive Strength (with passline, ASTM D-1621)
43.0
psi
Shear Strength (with passline, ASTM C-273)
46.8
psi
Tensile Strength (with passline, ASTM D-1623)
76.4
psi
Friability (with passline, % wt. loss, ASTM C-421)
0.71%
Dim. Stab. (with passline, 158° F., 28 day,
0.58%
ASTM D-2126)
Dim. Stab. (w/passline, 100° F./95% R.H.,
−0.32%
ASTM D-2126)
Dim. Stab. (w/passline, 158° F./95% R.H.,
−2.44%
ASTM D-2126)
Water Vapor Permeability (with passline, ASTM E-96)
2.09
perm in.
Water Absorption (no passline, ASTM D-2842)
0.79%
Machine Sprayed Prop.
(Gusmer H-2000; GX-7 Gun; 130° F. Temps.; 1500 psi Pressures)
Density (with passline, ASTM D-1622)
3.18
pcf
Compressive Strength (with passline, ASTM D-1621)
41.9
psi
Example 8
[0198]
Polyethylene Glycol (Carbowax 400)
32.70%
Mannich Polyol (Silpol SIP-425LV)
21.80%
Diethylene Glycol
7.27%
Surfactant (L-5440)
0.75%
Cell Opener (Calcium Stearate)
0.40%
Amine Catalysts*
3.36%
Diluents**
31.17%
Water
2.55%
*Amine catalysts: Polycat 8 = 1.04%; Dimethylethanolamine = 1.63%;
Curithane 52 = 0.36%; Niax A-1 = 0.33%.
**Diluents: Iris-isopropylchlorophosphate = 15.26%; Makon 10 =
10.90%; Dibasic Esters = 5.00%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
Component Temperatures
77°
F.
Initiation Time
4
sec.
Tack Free Time
12
sec.
Cup Density
2.97
pcf
Resin Viscosity (77° F.)
130
cps
Cup Open Cell Content
95.7%
Hand Mix Dimensional Stability
<2.0%
(158° F./95% R.H., 7 Days)
Example 9
[0199]
Polyethylene Glycol (Carbowax 400)
39.79%
Mannich Polyol (Silpol SIP-425LV)
26.53%
Surfactant (L-5440)
0.75%
Cell Opener (Calcium Stearate)
0.40%
Amine Catalysts*
3.36%
Diluents**
26.62%
Water
2.55%
*Amine catalysts: Polycat 8 = 1.04%; Dimethylethanolamine = 1.63%;
Curithane 52 = 0.36%; Niax A-1 = 0.33%.
**Diluents: tris-isopropylchlorophosphate = 15.56%;
Makon 10 = 11.05%.
Hand Mix Properties
Mix Ratio (A/B by Volume)
1:1
(by volume)
Component Temperatures
77°
F.
Initiation Time
4
sec.
Tack Free Time
12
sec.
Cup Density
3.02
pcf
Resin Viscosity (77° F.)
180
cps
Cup Open Cell Content
92.4%
Hand Mix Dimensional Stability
<2.0%
(158° F./95% R.H., 7 Days)
[0200] The invention and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification. | The invention relates to methods and compositions for preparing all water blown spray polyurethane foams by reacting a polyisocyanate with a polyol blend. The polyol methods and compositions of the invention comprises a polyol component, water, a cell opening agent, and a diluent. Polyurethane foams prepared according to the invention meet the physical and processing requirements stipulated by the industry. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a process for the production of pulp. More specifically, the present invention relates to an improved process to break down lignin macromolecules and liberate cellulose fibers in lignocellulosic material using delignifying reactants with a gaseous organic agent as a heating and reaction-accelerating media.
BACKGROUND OF THE INVENTION
[0002] The majority of the papermaking pulp produced in the world today is produced by the so-called kraft method. Kraft pulping produces strong fibers, a fact that has given the method its name. This method, however, has the drawback of being very capital intensive. This is due to the need for a very complex system for chemicals recovery and very large unit sizes in the reactors. The reactors have in fact become so big that controlling the actual reactions and liquor circulations has become extremely difficult. The huge unit sizes in all parts of the process also leads to very large in-process inventory and a process that reacts very slowly to e.g. grade changes, etc. Any improvement that would lead to a faster process with shorter in-process delays would therefore have to be seen as a big step forward.
[0003] Another problem regarding the kraft method is the use of sulfur, which leads to larger amounts of chemicals being in circulation, odor problems, as well as making the recovery of spent chemicals extra complicated. A process without sulfur would make it possible to have much more efficient burning processes for the dissolved organic material in the process.
[0004] In order to address the problems of slow and cumbersome processes and to get rid of the sulfur, and often all inorganic chemicals in the process, several researchers have proposed the use of organic solvents to act as a cooking chemical and dissolve the lignin that holds the cellulose fibers together in wood.
[0005] According to J. Gullichsen, C-J Fogelholm, Book 6A, Papermaking Science and Technology, Fapet, 1999, Helsinki, Finland, p. B411, the pulping methods using organic solvents can be classified as follows:
Autohydrolysis methods, in which organic acids released from the wood by thermal treatment act as delignification agents Acid catalyzed methods, in which acid agents are added to the material Methods using phenols Alkaline organosolv methods Sulfite and sulfide cooking in organic solvents Cooking using oxidation of lignin in organic solvent
[0012] The basic idea in autohydrolysis, as explained for instance in U.S. Pat. No. 3,585,104 (Kleinert), is to cook the wood in a solvent at high temperature. The high temperature leads to hydrolysis of sugars present in the wood, thus releasing acids. These acids are then supposed to break down and dissolve lignin together with the solvent. The drawback of this process is that very harsh conditions are needed in order to properly delignify the wood. This leads to yield losses and low pulp quality. Others have attempted to improve on the basic idea in order to improve the pulp quality. One such attempt is the so-called IDE process described in EP 0 635 080. The idea is to limit the drop in pH in order to salvage pulp quality. The process is proposed to achieve this by cooking using solvent in a countercurrent manner, thus removing the acids as they are formed early in the cook, and by adding alkali to maintain the pH as desired. The method has never been possible to implement on a commercial scale, possibly due to the large amount of solvent needed to maintain the proposed countercurrent flow. Further, even in the laboratory it is not well suited for all wood species.
[0013] If pulp quality is not seen as a major criteria (emphasis on by-product value), acid can be added to the system to increase the speed of the pulping process. Processes have for instance been developed that use acetic and formic acid as delignification agents. The drawback for these processes is that there is no market for the inferior quality pulp, and that severe corrosion problems arise in the equipment.
[0014] The so-called Organocell process has been closest to large-scale commercialization of the solvent-using pulping methods. This process is a variant of alkaline organosolv pulping, using simultaneous action of soda-anthraquinone and organic solvent on the lignin. The process seemed to give acceptable pulp quality in the laboratory, but when tried on mill scale the results were not satisfactory.
[0015] All prior pulping methods employing organic solvents have been attempts to develop substitutes for the presently dominating kraft pulping method. However, kraft pulping has been constantly improved upon for the last 100 years and is today quite efficient and thus hard to compete with. This can be seen from the fact that no solvent pulping method has proven to be commercially viable. There is, however, still room for improvement in the kraft process itself. For example, the odors of the process are seen as a problem, as is the fact that the reactors are becoming increasingly large and hard to control. Steps have been taken to improve alkaline kraft pulping. One such method is rapid steam phase pulping. The idea is to impregnate the wood with all the alkaline chemicals needed for the reactions in an impregnation stage, followed by heating in a water steam phase. This would make the reactors smaller and partly remedy the problems with odor as described in Canadian Patent No. 725,072. However, this method has not demonstrated enough improvement over the kraft process in liquid phase—yield increase has been very small and reactors still very big, leading to too high chip columns in vapor phase, in turn leading to compaction and collapsing of the digester content, thus plugging flows and destroying pulp quality.
[0016] In light of the current research it is clear that the previous research has failed largely because the true role of the organic solvent was not identified. In the current research it has been clearly seen that organic solvents do not participate in the reactions themselves as a solvent of lignin or active chemical, but in fact only have the impact of providing such a reaction environment as to boost the efficiency of other delignifying chemicals.
SUMMARY OF THE INVENTION
[0017] In accordance with the present invention, these and other objects have now been realized by the invention of a process for production of pulp from comminuted lignocellulosic material comprising impregnating the comminuted lignocellulosic material in a liquid phase containing fresh reactants at a first temperature so as to produce impregnated lignocellulosic material, removing a majority of the liquid surrounding the impregnated lignocellulosic material, heating the impregnated lignocellulosic material to a second predetermined reaction temperature using the heat released by the condensation of a gaseous organic agent, and maintaining the second predetermined reaction temperature for a desired reaction time, the second predetermined reaction temperature being higher than the first temperature. In a preferred embodiment, the fresh reactants comprise a solution containing at least one of a hydroxide, a sulfide, an anthraquinone, a carbonate, a polysulfide ion, a sulfite or an acid.
[0018] In accordance with one embodiment of the process of the present invention, the gaseous organic agent is an aliphatic alcohol, a ketone, or an aldehyde. In a preferred embodiment, the organic agent is methanol, ethanol, propanol, butanol, acetone or a mixture of these compounds, preferably in a purity of over 50% with the remainder being water and impurities.
[0019] In accordance with one embodiment of the process of the present invention, the first temperature is between about 20 and 130° C.
[0020] In accordance with another embodiment of the process of the present invention, the second predetermined reaction temperature is a maximum of between about 120 and 200° C.
[0021] In accordance with another embodiment of the process of the present invention, the impregnating step is between about 10 and 120 minutes long.
[0022] In accordance with another embodiment of the process of the present invention, the heating step is between about 2 and 400 minutes long.
[0023] In accordance with the present invention, an improved method for producing pulp from lignocellulosic material has been provided.
[0024] According to the present invention, the lignocellulosic material is first impregnated with reactant chemicals. This can be performed by submersing the material in a solution containing the chemicals, followed by a removal of excess liquid. The liquid can be any solution containing a delignifying agent. Examples of such liquids are aqueous solutions of hydroxide, sulfide, sulfite, bisulfite, carbonate (e.g. the sodium compounds), sulphur dioxide, anthraquinone, amines or acids. The impregnation can also be performed by contacting the material with delignifying chemicals in the gas phase. An example of this is sulphur dioxide gas that is taken up by the chip moisture.
[0025] Subsequently, the energy required for the delignification reactions is provided through heating with a gaseous organic agent, condensing and releasing energy to the solid lignocellulosic material. For the purpose of this specification, a gaseous organic agent is any organic material above its boiling temperature at the pressure of the process at the relevant stage. The gaseous organic agent may comprise various amounts of vapors or droplets, i.e. it need not be in a completely gaseous state. Examples are lower alkyl alcohols, ketones and aldehydes. Mixtures of organic agents may be used, and the agent may contain water. In an industrial process it will not be practical to purify the stream of circulated organic agent. Therefore, the composition will change over time and become a mixture of several volatile compounds. For the purpose of the present invention it is considered that the heating media used is the same as originally used, as long as at least 50% (by mass) of the heating stream is made up of the original organic agent or agents. Preferably, the mass percentage of organic agent(s) in the heating stream is at least 60; more preferably, at least 75; and most preferably at least 90.
[0026] Preferable agents include methanol, ethanol, propanol, butanol, acetone and any mixture thereof.
[0027] Preferably, the temperature during the impregnation step is in the range of from about 20 to 130° C., and the duration of this step is in the range of about 10 to 130 min. The temperature during the heating step with a gaseous organic agent is higher than the temperature during the impregnation step.
[0028] Preferably, the temperature during the heating step reaches a temperature in the range of from about 120 to 200° C.; the pressure during the step evidently corresponds to the physical properties of the organic agent or mixture of agents used. Preferably, the duration of this step is in the range of from about 2 to 400 min.
[0029] A surprising benefit is seen when pre-impregnated material is heated by this means. The beneficial effects include very rapid reactions, high yield, lowered energy demand, lowered demand of cooking chemicals and lower rejects compared to conventional kraft pulping. In contrast to earlier work on the so called organosolv processes, the present invention does not involve using the organic agent to dissolve or react with lignin, but rather, the organic agent provides a new kind of non-aqueous media for rapid heating and acceleration of reactions taking place inside the impregnated chips.
[0030] The benefit seen from the surprising rise in the speed of delignification can be utilized in several ways, including those mentioned below. For instance, a pulp mill restricted in chemicals recovery capacity could produce much more pulp due to better pulp yield and lower cooking chemicals consumption.
[0031] On the other hand, a pulp mill restricted by digester volume could enjoy increased throughput due to a faster process. It could use lower temperatures and gain heat efficiency. A mill restricted by the bleaching line could delignify the wood further in cooking and thus increase production.
BRIEF DESCRIPTION OF THE DRAWING
[0032] In the following detailed description, the method of the present invention is disclosed in detail, all reference numerals relating to FIG. 1 , which is a schematic elevational view of the essential process steps of the present invention.
DETAILED DESCRIPTION
[0033] Lignocellulosic materials, such as any type of wood, straw or bamboo, is comminuted into easily processed parts (chips in the case of wood; in the following, reference is made to chips) as is customary. The chips are steamed to facilitate air removal. Referring to FIG. 1 , the steamed chips ( 1 ) are brought into contact with liquid containing lignin-breaking reactants, as disclosed above, at a high concentration ( 2 ). The chips are impregnated with the liquid under such conditions that enough reactants are transferred to the chips to enable lignin cleavage to the desired level. The dosage of reactants and combination of time and temperature in both the impregnation and the delignification steps are chosen based on the desired degree of delignification.
[0034] Impregnation using a gaseous compound can also be used utilizing a chemical that is enriched in the moisture present in the chips.
[0035] After impregnation, the excess liquor is removed and concentrated for reuse ( 4 ) and the chips are brought into contact with a gaseous organic agent at the preferred temperature. This constitutes the heat-up stage ( 3 ), where the gaseous organic agent is brought in through line 5 . The condensation of the heated gaseous agent on the chips releases energy, thus heating the chips to the reaction temperature at which the chips are kept for a predetermined time in stage 6 . The temperature is maintained by adding organic agent as needed. After the reaction time the chips are washed and cooled down in stage 7 , according to methods known by those skilled in the art. From the washing stage, a mixture of wash water, spent chemicals and organic agent is removed in stream 9 . This mixture is heated to vaporize the organic agent, which is then recycled to the heating stage. The spent delignification chemicals are recovered using an appropriate technique, such as current recaustisizing methods, and brought back into the impregnation step.
[0036] There are several possible ways to utilize the present invention, depending on which aspect of chemical pulping is seen as the most valuable. Below are a few examples of the aim of the process and what a possible embodiment would be to achieve this aim.
[0037] In one variation of the process of the present invention, aiming at minimizing the physical size of a batch digester the process is as follows. The digester is filled with chips according to prior art methods. The digester is then filled with white liquor and impregnation is performed for 10 to 120 minutes at 20 to 130° C. After the impregnation time the spent impregnation liquor is withdrawn and recycled. The chips (without free liquor) are then heated to between 140 and 200° C. by allowing gaseous methanol to condense on the chips and by keeping the digester at this temperature for the duration of the reactions by the addition of gaseous methanol.
[0038] In a preferable embodiment for a continuous process, the chips are steamed and brought into an impregnation vessel where they are impregnated with white liquor at 20 to 130° C. for 10 to 120 minutes. The impregnation vessel can be built with either co- or countercurrent liquor flow configuration, according to principles known to a person skilled in the art. From the impregnation vessel the chips are transferred to the digester, at the top of which the free liquor is removed from the chips, according to prior art methods. When the liquor has been removed the chips are fed forward so that they are brought into contact with a methanol vapor atmosphere at 140 to 200° C. and kept at this temperature for the duration of the reaction time. The digester used can be similar to present continuous kraft digesters or specifically built for the present invention.
[0039] In a preferred embodiment of the present invention aimed at minimizing cooking plant (batch or continuous) steam consumption, impregnation is performed at 30 to 130° C. and a reaction temperature of 120 to 140° C. is used, the reaction temperature however being higher than the impregnation temperature.
[0040] In a preferred embodiment aimed at achieving maximum pulping capacity for a given capacity of chemicals recovery, the impregnation is performed using diluted white liquor and the reaction time is extended to that typical of present generation digesters.
[0041] In a preferred embodiment aimed at simplifying the chemicals recovery, the improved cooking efficiency can be used to make it possible to use sulfur-free cooking that does not require the use of the so called lime cycle in chemicals recovery. Such processes are green liquor pulping, pulping using carbonate or autocaustisizing using borohydride.
[0042] In a preferred embodiment of the present invention, it is used to pulp raw materials other than wood, such as straw, reeds or bamboo. Due to the boost given to the process by heating using a gaseous organic agent, less powerful lignin degrading chemicals, such as carbonate, can be used in the process.
[0043] In addition to the embodiments presented above based on the dominating pulping method, kraft cooking, the invention boosts the reactions of any cooking method, such as sulfite and bisulfite cooking.
EXAMPLES
[0044] The method of the present invention can be used with a wide variety of raw materials and cooking methods. In the following examples, numerical data for tests with both wood and straw pulping is presented. All tests have been performed using the same laboratory scale digester. “Steam” refers to steam phase water.
[0045] The digester used has been purposely built to facilitate the testing of vapor phase processes. The design includes a special heating jacket that prevents the heating power of the vapor from being spent on heating the digester itself. This problem, typical for laboratory scale systems, will not arise in industrial applications as the ratio of wood to equipment weight is much higher.
[0046] Wood as Raw Material
[0000]
Experimental Wood:
fresh softwood mill chips, dry matter
content 50%
Batch size:
400 g wood as oven dry mass
Chemicals:
mill white liquor
Digester size:
2200 ml
[0000]
TABLE 1
Amounts of liquor used in softwood pulping experiments:
Cooking liquor in batch pulping
2000
ml
(same liquor present throughout the process)
Steam phase & present invention:
Impregnation liquor:
1500
ml
Impregnation liquor removed:
800
ml
Heating agent fed into the system:
600
ml
[0000]
TABLE 2
Comparison of process conditions in softwood pulping
using prior art technology and the present invention.
Batch
kraft
Kraft
Conventional
with
steam
Present
batch kraft
methanol
phase
invention
Impregnation
90
95
80
80
temperature
(° C.)
Impregnation
60
60
60
60
time (min)
Alkali into
25%
25%
19%
19%
reaction
stage (EA on
wood as
NaOH) 1
Composition of
heating media:
H 2 O steam
100%
Liquid H 2 O
100%
40%
Organic
60%
agent liquid
Gaseous
100%
organic
agent
Reaction
175
175
175
175
temperature
(° C.)
1 In conventional pulping, the term alkali charge is used to determine how much chemical is used. In vapor phase pulping, the important variable is the amount of alkali that has been absorbed by the wood prior to the reaction stage. In the conventional and batch kraft examples the number relates to alkali charge; in the steam phase and in the examples of the present invention, the number has been calculated by subtracting the charge of alkali left in the spent impregnation liquor from the amount originally charged
[0047] Results
[0000]
TABLE 3
Results from softwood pulping using prior
art technology and the present invention.
Batch
kraft
Kraft
Conventional
with
steam
Present
batch kraft
methanol
phase
invention
Kappa
23
23
23
23
number
Reaction
80
73
74
38
time (min)
Alkali
17.4%
18.9%
16.9%
15.5%
consumption
(EA on wood
as NaOH)
Total yield
44.6
45.7
48.7
49.8
(% on wood)
Rejects (%
0.1
0.2
0.1
0.1
on wood)
[0048] As can be seen from Table 3, the benefits of the present invention are quite clear. Compared to liquid phase processes (conventional batch kraft and batch kraft with methanol) the amount of chemicals needed in the digester in the reaction stage is much lower. Also, compared to a steam phase without methanol, the present invention offers a huge benefit in terms of total reaction time and alkali consumption. The benefit seen in reaction time can also be translated to a lower need for alkali in the reaction stage, or lower reaction temperature when using the same reaction time as for the other processes, further increasing the flexibility of the process.
[0049] In the above example all cooks have been performed at the same reaction temperatures. Therefore, the benefit of accelerated cooking kinetics can be seen directly as a decrease in reaction time. In practical chemical pulping, time and temperature is usually combined into a single variable, the so-called H-factor. In experiments at varying temperatures it has been seen that the benefits of the current process are observed as a decrease of almost 50% in the H-factor required to reach a certain degree of delignification, regardless of temperature.
[0050] Non-Wood Raw-Materials
[0051] The present invention is also suitable for use with other raw-materials than wood, and also enables the use of cooking chemicals that under normal circumstances lack the delignifying power to produce acceptable pulp. Table 5 shows a comparison between the use of steam phase pulping and the present invention for straw delignification, using only carbonate as the pulping chemical. Both cooks have been performed identically except for the choice of heating media.
Experimental
[0052] Raw-material: air dried wheat straw, dry matter content 90%
[0053] Batch size: 250 g as oven dry straw
[0054] Pre-treatment: the straw was cut into approx. 5 cm long pieces for easy handling
[0055] Equipment: present invention and steam-phase pulping performed in the same digester as the softwood experiments. The conventional pulping experiment shown in Table 6 was performed using a simple air-heated autoclave digester.
[0000]
TABLE 4
Amounts of liquor used in straw pulping experiments:
Cooking liquor in batch pulping
2000
ml
(same liquor present throughout the process)
Steam phase & present invention:
Impregnation liquor:
2000
ml
Impregnation liquor removed:
1000
ml
Heating agent fed into the system:
600
ml
[0000]
TABLE 5
Comparison of wheat straw pulping performance of
steam phase pulping and the present invention using
Na 2 CO 3 as the delignification reagent.
Carbonate AQ
Present
steam-phase
invention
Impregnation
80
80
temperature (° C.)
Impregnation time
60
60
(min)
Concentration of NaOH
0
0
in
impregnation/cooking
liquor (g/l)
Alkali into reaction
107
99
stage (% Na 2 CO 3 on
straw)
AQ in impregnation (%
0.2
0.2
on straw)
Reaction temperature
160
160
(° C.)
Time at reaction
71
69
temperature (min)
Kappa number
58
18
Total yield (% on
58.3
52.4
straw)
Rejects (% on straw)
15.3
2.9
[0056] From Table 5 it can clearly be seen how the accelerating effect of the organic agent makes it possible to produce low-reject pulp using only carbonate as the pulping chemical. The pulp produced with the steam-phase method is unusable as papermaking pulp due to high rejects and high lignin content. The fact that no sodium hydroxide is needed in the present invention constitutes an immense benefit over present industrial processes, as chemicals recovery can be simplified drastically.
[0000]
TABLE 6
Comparison of the wheat straw pulping performance
of the present invention using Na 2 CO 3 and state
of the art technology using NaOH
Conventional
batch soda
Present
AQ process
invention
Impregnation
No separate
90
temperature (° C.)
impregnation
Impregnation time
No separate
60
(min)
impregnation
Heat-up time (min) 1
45
9
Concentration of NaOH
31
0
in
impregnation/cooking
liquor (g/l) 2
Concentration of
9.3
212
Na 2 CO 3 in
impregnation/cooking
liquor (g/l) 2
AQ in
0.1
0.2
impregnation/cooking
(% on straw)
Reaction temperature
160
160
(° C.)
Time at reaction
10
69
temperature (min)
Kappa number
17
18
Total yield (% on
49.1
52.4
straw)
Rejects (% on straw)
3.4
2.9
1 Heat-up 25-160° C. for conventional, 90-160° C. for present invention
2 In conventional - all liquid used in cooking, in present invention - free liquor removed after impregnation
[0057] Table 6 shows a comparison between the present invention and the currently industrially important soda-AQ method. As can be seen, the yield of pulp is superior in the present invention and no sodium hydroxide is needed. The benefits of the present invention are hereby twofold. Investment costs for a new mill are kept low as chemicals recovery is simplified and the operating costs are lower, as less raw material is required for the production of a given amount of pulp.
[0058] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. | The invention relates to an improved process to break down lignin macromolecules and liberating cellulose fibers in lignocellulosic material using delignifying reactants with a gaseous organic agent as a heating and reaction-accelerating media. Lignocellulosic material is first impregnated with reactant chemicals, e.g. commonly used agents such as sodium hydroxide and sodium sulfide. Subsequently, the energy required for the delignification reactions is provided through heating with a gaseous organic agent such as methanol or ethanol, condensing and releasing energy to the solid lignocellulosic material. The temperature during the heating step with a gaseous organic agent is higher than the temperature during the impregnation step. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This invention claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/507,126 filed Oct. 1, 2003, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention is directed to brassieres. More particularly, this invention is directed to a wireless support system for a brassiere or other breast supporting garments.
BACKGROUND OF THE INVENTION
Brassieres provide support and enhance the shape of breasts. Brassieres often have a device in the cups of the brassiere to provide support. Devices intended to provide support and shaping for the cups of a bra and similar articles have long been known. These devices are commonly known as underwires and are inserted into and held within a fabric sleeve disposed about the periphery of the lower section of the bra cup. They are made from materials, such as bone, metal or plastic, and are provided in various forms, shapes and cross-sections. Most commonly, the underwire is formed of relatively thin metallic pieces of rectangular cross-section, shaped into an essentially semi-circular or U-shaped form that allows the underwire to be fitted within a sleeve disposed about the periphery of the lower half of the bra cup.
While such underwire structures have achieved widespread usage, a number of significant disadvantages result from their use. In particular, the underwires can damage the fabric sleeve into which the underwire is inserted or irritate the skin of a user leading to discomfort and sometimes bruising. Deformation or distortion of the underwires arises from washing and drying of bras containing underwires. Multiple washings lead to degradation of the fabric of the garment due to shrinkage of the fabric and/or the relative movement occurring between the stiff, rigid metal underwire and the fabric of the bra brought about in machine washing and drying. Using underwires coated with a polymeric material or metal underwires that have plastic tips at their ends does not alleviate these problems completely.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a wireless support structure for breast-supporting articles, such as bras (with or without straps), swimwear, sportswear, contour or bra pads, daywear, camisoles and the like, that provides the necessary rigidity to accomplish its supporting function.
It is another object of the present invention to provide a wireless support structure for breast supporting articles that is form fitting, to avoid unsightly gaps in the supporting articles underneath the breast.
It is a preferred object of the present invention to provide a brassiere comprising (i) an outer layer having two front bra cups and two back bands extending from the lateral sides of the two front bra cups; (ii) two sideback supports adhered to the outer sides of the front bra cups and inside the outer layer; (iii) at least one centerfront support adhered to the inner sides of the front bra cups and inside the outer layer, as shown in the drawings; and (iv) an inner layer having two front bra cups with side backs extending from the lateral sides of the two front bra cups, wherein the two side backs end approximately at the outermost edge of the two sideback supports, and further wherein the inner layer is adhered to the two sideback supports and at least one centerfront support. The sideback supports and the centerfront support(s) are preferably made of Mylar®.
It is a second preferred object of the present invention to provide a brassiere comprising (i) an outer layer having two front bra cups and a single back band extending from the lateral side of the first bra cup to the lateral side of the second bra cup; (ii) two sideback supports adhered to the outer sides of the front bra cups and inside the outer layer; (iii) two centerfront supports adhered to the inner sides of the front bra cups and inside the outer layer, as shown in the drawings; and (iv) two inner layers each having one front bra cup with a side back extending from the lateral sides of each of the two front bra cups, wherein the two side backs end approximately at the outermost edge of the two sideback supports, and further wherein the inner layer is adhered to the two sideback supports and two centerfront supports. The sideback supports and the centerfront support(s) are preferably made of Mylar®.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a perspective view of a brassiere showing the front of a frame of a wireless support system according to one embodiment of the present invention.
FIG. 1 b is a perspective view of a brassiere showing the back of a frame of a wireless support system according to one embodiment of the present invention.
FIGS. 2 a - 2 f are perspective views of embodiments of sideback supports for the wireless support system of the present invention.
FIGS. 3 a - 3 e are perspective views of embodiments of centerfront supports for the wireless support system of the present invention.
FIG. 4 is a perspective view of a brassiere showing a frame of a wireless support system according to a second embodiment of the present invention, in which the brassiere is strapless.
FIG. 5 a is a perspective view of a brassiere showing a frame of a wireless support system according to a third embodiment of the present invention, in which the brassiere connects at the front of the body.
FIG. 5 b is a perspective view of a brassiere showing the back of a frame of a wireless support system according to a third embodiment of the present invention, in which the brassiere connects at the front of the body.
FIG. 6 is a perspective view of a brassiere showing a frame of a wireless support system according to a fourth embodiment of the present invention, a banded set in bra cup brassiere, in which the bra cups are produced separately from the rest of the brassiere frame, and subsequently attached to the appropriate place on the frame.
FIG. 7 a is a perspective view of a brassiere showing a wireless support system according to a fifth embodiment of the present invention, a bandless, or un-banded, set in bra cup brassiere, in which the bra cups, front band and back bands are each produced separately and subsequently attached to one another, with the front band located between the two bra cups and the back bands attached to the lateral sides of said bra cups.
FIG. 7 b is a perspective view of the back of the front band of the brassiere according to the fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a , a perspective view of a bra 10 made according to the present invention is shown. It will be understood that the present invention can be incorporated into any style bra, swimsuit or other undergarment known to those of ordinary skill in the art. The bra 10 features an outer layer, 12 , having two front bra cups, 14 and 16 , and two back bands, 18 and 20 , extending from the lateral sides of the two outer layer front bra cups, 14 and 16 , and preferably having a back retaining device, 22 , attached to the ends of the back bands and including a set of locking pieces engageable with each other. Preferably, the outer layer is made of two or more pieces of material, but in an alternative embodiment the outer layer may be made of one piece of material.
The bra 10 also features at least one centerfront support 24 and two sideback supports 26 and 28 . The centerfront support 24 is located between the two outer layer front bra cups, 14 and 16 . The centerfront support 24 may be in the shape of an inverted V, as shown in FIGS. 3 a - 3 d , the sides of the V following the shape of the two outer layer front bra cups, 14 and 16 . The opening between the two bottom ends of the inverted V may be of varying shapes and sizes. Alternatively, the centerfront support 24 may be comprised of two separate support pieces, 68 and 70 , as shown in FIG. 3 e , that follow the shape of the outer layer front bra cups. The sides of the centerfront support 24 , as shown in FIGS. 3 a - 3 d , or the two separate centerfront supports, 24 , as shown in FIG. 3 e , may be joined together by a stabilizing ribbon.
The bra 10 also features two sideback supports, 26 and 28 . The sideback supports 26 and 28 follow the shapes of the outer layer front bra cups, 14 and 16 , from the bottom of the outer layer front bra cups to the outer sides. The sideback supports, 26 and 28 , may have one or multiple slits, 32 , and/or legs, 34 , on the side (see FIGS. 2 a - 2 f ) that allow for proper fitting of the bra 10 to the body. The legs, 34 , may be joined together by stabilizing ribbons or alternatively by various stitch-type configurations known in this art (such as single needle, double needle, three step zig zag, two step zig zag, etc.). A flexibility gap 80 exists between the sideback supports, 26 and 28 , and the centerfront support(s), 24 . This flexibility gap allows for proper fitting, without bulges, to the body. The sideback supports 26 and 28 may be held to the centerfront support(s) 24 by stabilizing ribbons which span the flexibility gaps, 80 or alternatively by various stitch-type configurations known in this art (such as single needle, double needle, three step zig zag, two step zig zag, basting, etc.).
The centerfront supports, 24 , and the sideback supports, 26 and 28 , are preferably made of a flexible, stable, and rigid plastic or polyester material. More preferably, the centerfront support(s), 24 , and sideback supports, 26 and 28 , are made of a polyester film that is flexible, stable and rigid. The polyester film is preferably Mylar®, and is preferably pre-bonded with an adhesive, such as an adhesive film. For example, the Mylar® used in the present invention may be Mylinex® #561 (obtained from Tecra®) which is a Mylar® film pre-bonded with Bemis #3402, an adhesive film, and pretreated on both sides for improved adhesion of inks and coatings, and specially formulated for improved die cutting. Bemis #3402 is a soft, highly elastic, polyurethane adhesive film designed for intimate apparel applications, to provide excellent bond strength while maintaining the softness, stretch, recovery, and molding properties that are critical in intimate apparel.
Mylinex® #561 is a tough, general purpose film that is transparent and pretreated to have a textured surface to provide ease of handling, good adhesion, and processability. Mylinex® #561 is translucent in heavier gauges and has balanced tensile properties and excellent resistance to moisture and most chemicals. Mylinex® #561 can withstand temperature extremes from −100° F. to 300° F., and does not become brittle with age under normal conditions. Of course, other polyester films with properties similar to Mylar® or Mylinex® #561, and other adhesives or adhesive films to be applied to Mylar®, may be used in the present invention. For example, adhesive webs, powders, or dots may be applied to the polyester film.
The bra 10 also features an inner layer, 38 , having two front bra cups, 40 and 42 , and two back bands, 44 and 46 , extending from two lateral sides thereof, respectively, wherein the two back bands, 44 and 46 , end approximately at the outermost edge of the two sideback supports, 26 and 28 (see FIG. 1 b ). In an alternative embodiment, the inner layer, 38 , extends beyond the two sideback supports, 26 and 28 , to the end of the back bands, 18 and 20 of the outer layer. The inner layer may be composed of one or more pieces of material. The front bra cups of the inner layer, 40 and 42 , are formed such that they fit together with the front bra cups of the outer layer, 14 and 16 , and together they form the front bra cups of the bra, 48 and 50 .
The outer layer is typically made of a decorative/non-decorative material such as lace, jacquard or satin. The inner layer is preferably made of a soft material that absorbs and wicks moisture away, such as cotton or polypropylene cloth. The stabilizing ribbons are preferably made of a cotton or polypropylene cloth. The type of fabric used for the bra of the present invention will of course depend on the proposed use of the bra (everyday use, sports bra, swimsuit, etc.).
The optional shoulder straps, 52 and 54 , are each located with a first end, 56 and 58 , attached to the top edge of the bra cups, 48 and 50 , and a second end, 60 and 62 , attached to the back bands, 18 and 20 , and have a conventional plastic buckle attached thereto that allows for the straps to be adjusted for length. Alternative embodiments of the shoulder straps include a “racerback” design, in with the shoulder straps join together in the back of the bra and connect as one to the back bands (in the case of a bra without locking pieces) or divide again into two, each connecting to either side of the back retaining device, 22 . FIG. 4 depicts an embodiment of the present invention that does not have the optional shoulder straps.
In an alternative embodiment of the present invention, the bra has a front retaining device, 64 including a set of locking pieces engageable with each other (see FIG. 5 a ) instead of a back retaining device. In this embodiment, the outer layer, 12 , has two separated front bra cups, 14 and 16 , and a single back band, 66 , connecting said two separated front bra cups, 14 and 16 . Similar to the previous embodiment, this embodiment of the present invention includes two sideback supports, 26 and 28 . The bra of this embodiment has two centerfront supports, 68 and 70 , one each located between the front bra cups, 14 and 16 , and the front retaining device.
In this alternative embodiment, the inner layer may be comprised of two separate pieces of material, 72 and 74 (see FIG. 5 b ). Alternatively, the inner layer may be comprised of a single piece of material that follows the same pattern as the outer layer, 12 (embodiment not depicted).
In any of the embodiments of the present invention, the bra cups, 48 and 50 , may further comprise bra pads, which will enhance the shape of the bust. These bra pads may be made of material known to one of skill in the art, including commonly known foam (polyester or polyether), spacer, fiberfill or gel, and may or may not be removable from the bra.
Furthermore, as depicted in FIG. 6 , in any of the embodiments of the present invention (i.e., whether strapless, front clasp, or rear clasp), the bra cups may be set in bra cups, 82 and 84 , set within a frame, 86 . In the art, such a brassiere is referred to as a banded set in bra cup brassiere. The set in bra cups, 82 and 84 , are made separately from the frame, 86 , of the brassiere, and then attached to the frame, 86 , prior to completion. In such an embodiment, the outer and inner layers, 88 and 90 , of the frame of the brassiere have two U-shaped cut-outs in the front of the frame, into which the completed set in bra cups, 82 and 84 , are set and attached. Prior to or after attaching the set in bra cups, 82 and 84 , to the front of the frame, 86 , the shoulder straps (if present) are attached to the set in bra cups, 82 and 84 . The set in bra cups, 82 and 84 , may have a bra pad, as disclosed above, and may further be comprised of an outer and/or inner layer of material.
In addition, as depicted in FIG. 7 a , in any of the embodiments of the present invention (i.e., whether strapless, front clasp, or rear clasp), the bra cups may be set in bra cups, 92 and 94 , and the brassiere frame may be composed of a center band, 96 , which is affixed between the bra cups, 92 and 94 , and two back bands, 98 and 100 , may be affixed to the lateral sides of the set in bra cups, 92 and 94 . In the art, such a brassiere is referred to as a bandless set in bra cup brassiere. In this embodiment, the center band, 96 , has an outer and an inner layer, 102 and 104 , and the centerfront support, 24 , is placed between the outer and inner layers, 102 and 104 , of the center band, 96 , prior to attaching the center band, 96 , to the set in bra cups, 92 and 94 . Similarly, the back bands, 98 and 100 , have outer and inner layers, 106 and 108 , and the sideback supports, 26 and 28 , are placed between the outer and inner layers, 106 and 108 , of the back bands, 98 and 100 , prior to attaching the back bands, 98 and 100 , to the set in bra cups, 92 and 94 . The set in bra cups, 92 and 94 , may have a bra pad, as disclosed above, and may further be comprised of an outer and/or inner layer of material.
Moreover, in any of the embodiments of the present invention, the bra may be a maternity and/or nursing bra, in which front bra cups, 14 and 15 , can be partially detached by the wearer to expose the breast for breastfeeding.
The bra, 10 , of the present invention is made generally by cutting the inner layer, 38 (using a GERBERCUTTER® or die cutter), to the appropriate size, removing release paper (not shown) and placing the sideback supports, 26 and 28 , and the centerfront support(s), 24 or 72 and 74 , on the appropriate location on the inside part of the outer layer (also cut using a GERBERCUTTER® or die cutter), with the film (texturized) side up. The sideback supports, 26 and 28 , the centerfront support(s), 24 or 72 and 74 , and the inner layer, 38 , are preferably pre-bonded with an adhesive. The sideback supports and the centerfront support(s) may be adhered to the inner layer with a glue stick and/or a heat regulated tool type-gun so as to spot seal them, reinforcing the proper placement prior to the final press bond sealing. The outer layer, 12 , cut to the appropriate size, is then placed on top of the inner layer/centerfront support/sideback support assembly, and aligned properly. This assembly is then heat pressed, permanently bonding all layers. As an exemplary embodiment, the heat press has a temperature of about 350-400.degree. F., and is left on the assembly for approximately 25-45 seconds (dwell time). One of skill in the art could easily adjust the temperature of the press and the dwell time in accordance with the types of fabric, adhesive, and polyester film used to make the bra of the present invention. After the bra assembly is cooled, it is cut into the desired shape using an automated cutter. As an alternative, the bra assembly may be die cut into the desired shape. In the embodiment in which set in bra cups 82 and 84 , or 92 and 94 , are used (whether in a banded or bandless set in bra cup brassiere), the brassiere frame or the center band and back bands (including the inner and outer layer, sideback supports, and centerfront supports) is/are constructed, similar to as described above, and the set in bra cups 82 and 84 , or 92 and 94 , are made separately and then attached to the brassiere frame (as described above) or to the center band and back bands (as described above).
While it is apparent that the illustrative embodiments of the invention herein disclosed fulfill the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. For example, the present invention could be made of a variety of materials. Furthermore, the centerfront and sideback supports could be shaped differently to provide different support for different bust sizes. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the present invention. | The invention is directed to a wireless support system for a brassiere. The wireless support system comprises at least one centerfront support and two sideback supports which are composed of a material such as a polyester film. The two sideback supports may be attached to the centerfront support via a stabilizing ribbon or stitches. The brassiere of the present invention has the advantage of providing comfortable support that is form fitting. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a lens information introducing device in a camera for transmitting lens information to a camera body.
2. Description of the Prior Art
As the means for suitably quantizing a set value in a lens such as distance, aperture or the like and transmitting the same to a camera body, there is known one in which ON-OFF switches corresponding in number to the number of bits necessary for the transmission of the information are provided on the lens side or the camera body side and are mechanically operated or transmission of the information is carried out by relative movement of a brush contact and a code plate. (Examples of such means are disclosed in U.S. Pat. No. 3,928,858 corresponding to Japanese Laid-Open Patent Application No. 67650/1975 and U.S. Pat. No. 4,104,649 corresponding to Japanese Laid-open Patent Application No. 56926/1977.) However, such means requires many parts such as the brush contact, the code plate, the wiring parts, etc. to be provided in a lens or in a camera and this not only means the necessity of the space therefor but also has a disadvantage that considerable labor and cost are required for the wiring work and the check-up of the electrical reliability thereof.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lens information introducing device which is low in cost and high in reliability.
It is another object of the present invention to provide a lens having code patterns as a part of such lens information introducing device, and a camer body having a device for reading the code patterns.
The invention will become fully apparent from the following detailed description of some embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an embodiment of the lens information introducing device in a camera provided with code patterns.
FIG. 2 illustrates a digital signal in the embodiment of FIG. 1.
FIG. 3 is a block diagram showing the circuit construction for obtaining the digital signal in the embodiment of FIG. 1.
FIG. 4 shows specific examples of the binary coded code patterns.
FIG. 5 shows another embodiment of the lens information introducing device in a camera provided with the code patterns according to the present invention.
FIG. 6 shows the code patterns in the embodiment shown in FIG. 5.
FIGS. 7 and 8 show the conversion of the code patterns into digital signals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a camera body 1 had a lens L attached thereto, and an aperture ring 2 for setting the aperture value is rotatably supported relative to the camera body. In FIG. 1, an aperture scale 3 and a code pattern 4 for quantizing the aperture information are provided on the outer surface of the aperture ring. The code pattern 4 comprises binary coded stripes of light and dark, and the arrangement of these stripes is such that a set of stripes (in FIG. 1 five stripes) corresponds to an aperture set value, and forms an optical code plate. On the camera body 1, there is provided an optical system for covering the one set of stripes and projecting the conjugate image thereof onto the light-receiving surface of a light-receiving element 5 secured to the camera side. The optical system comprises, for example, an image forming lens 7 provided around an unshown pentaprism and a mirror 6 for bending the light from the code pattern 4 toward the lens 7. The light-receiving element 5 has its light-receiving surface divided into five segments so that five independent sets of photoelectric output signals can be produced from the five segments in accordance with the light and dark of the projected stripes. Designated by 10 is a distance ring. In the condition of FIG. 1, the stripes 4a, 4b, 4c, 4d and 4e of the aperture ring 2 are projected onto the light-receiving surface of the light-receiving element 5 by an optical system 6, 7 to form images 4a', 4b', 4c', 4d' and 4e' of the light and dark stripes which are conjugate therewith. Therefore, by processing the photoelectric outputs of the light-receiving elememt 5, there are obtained digital signals corresponding to these light and dark stripes, namely, signals 1, 0, 0, 1, 0 as shown in FIG. 2.
FIG. 3 shows a circuit for obtaining these digital signals, which are utilized for the exposure control and the display. In FIG. 3, the photoelectric outputs 100a-100e of the light-receiving element 5 are compared with the reference voltage 102a of a reference voltage generating circuit 102 by a comparator circuit 101. As a result, the digital signals as shown in FIG. 2 are obtained as the outputs 103a-103e of the comparator circuit 101. These digital signals 103a-103e are decoded by a decoder 104 and applied to an operational unit 105. The operational unit effects signal processing in accordance with the decoded inputs and other inputs such as, for example, film sensitivity, etc. as is well-known, and produces the result thereof to an exposure control unit 106 and a display unit 107. On the basis of the output of the operational unit, the exposure control unit 106 controls the shutter speed and the display unit 107 effects a predetermined display, for example, the display of the shutter speed controlled. The operational unit 105, the exposure control unit 106 and the display unit 107 may be of the well-known types.
FIGS. 4A and 4B show specific examples of the binary coded code pattern and this code pattern is binary coded into one-track light and dark stripes of the known M-sequences (maximal length sequences: FIG. 4A) and the improved M-sequences (FIG. 4B), respectively. The light-receiving element in the present example receives five bits of the pattern as shown at the block 5 of FIGS. 4A and 4B. The present example is one in which the aperture value is quantized by 1/3 of a step each. That is, in FIG. 1, the light receiving element 5 (photoelectrically reads (detects) five bits of light and dark stripes of the code pattern through the optical system 6, 7 and therefore, if the code patterns shown in FIGS. 4A and 4B are moved for one bit each in the direction of arrow correspondingly to the aperture value setting of the aperture ring, the patterns corresponding to the set aperture value are successively detected by the light-receiving element 5 as shown in FIGS. 4C and 4D, respectively. Thus, the aperture value quantized by 1/3 of a step each is transmitted to the camera body side.
The code patterns of the M-sequences and the improved M-sequences shown in FIGS. 4A and 4B, with the binary code pattern and the grey code pattern, and the well-known patterns in the field of displacement encoder, and in a lens, they are excellent in the following points in quantizing the lens information. (Of course, the present invention also permits the use of binary or grey code patterns.)
(1) In a binary code pattern or a grey code pattern, tracks corresponding to the number of bits of encoding must be prepared, whereas the code pattern of the M-sequences or the improved M-sequences can secure a number of bits necessary for the encoding by one track of code patterns and accordingly, when arranging such code pattern in a lens, the space occupied by it can be made smaller than the space occupied by the former code pattern and the reform of the conventional lenses can be simply accomplished.
(2) Being one track of code patterns, the code patterns of the M-sequences or the improved M-sequences are suited for the quantization of lens information obtained from a movable member having a relatively great angle of rotation such as the aperture ring or the distance ring.
(3) Since the code patterns of the M-sequences or the improved M-sequences are one track of code patterns, consideration need only be given to the direction of movement of the movable member (code pattern) for an error of the relative position between the code pattern and the reading means including the light-receiving element and there is a greater advantage in securing accuracy than that of the binary code pattern.
FIG. 5 shows another embodiment of the present invention. On the outer peripheral surface 8 of the aperture ring 2 of a lens, there are arranged photoelectrically legibly code-patterned numerals (for example, JIS-C6250: JIS stands for Japanese Industrial Standard). The code-patterned numerals are arranged correspondingly to the aperture value, as shown in FIG. 6, and are also visually legible. A light-receiving element 5' is divided into ten segments 10-19, each of which produces a photoelectric signal corresponding to the incident light. For example, a code pattern 8a projected and imaged on the light-receiving surface of the light-receiving element 5' by an optical system 6', 7' produces a distribution of the light and dark of the image on the light-receiving surface as shown in FIG. 7, and the output of each segment is converted into a digital signal by a comparator circuit as shown in FIG. 8, and is decoded by a decoder similar to that shown in FIG. 3. Subsequently, it is suitably processed as already explained in conjunction with FIG. 3. In providing on the aperture ring the code-patterned numerals as shown in FIG. 5, and where the number of figures of the aperture value is increased, for example, for f2 to f22, two sets of light-receiving elements 5' may be prepared so that the aperture value information may be obtained from the outputs of these two sets of light-receiving elements. Since such calligraphic style of figures is sufficiently visually legible, it is suited for the case as shown in FIG. 1 where there is no sufficient space available for both the code pattern and the ordinary scale to be provided. Further, as the object of the quantization of the lens information set value, distance, guide number or other fixed lens information may be selected in addition to aperture. It is also possible to make such a design that not only a bit of lens informtion but also a plurality of bits of lens information can be read. Also, in interchangeable lens groups, quantizing means for various kinds of set values can be provided at a low cost. A code plate can be simply added to the outside of the aperture values, etc. by alumite printing and thus, the reform of the conventional lens can be readily accomplished.
According to the present invention, the lens and the camera body are photoelectrically connected with each other and this eliminates the need to provide an electrical contact or a mechanical operating member as in the prior art, and there is provided a lens information introducing device of high reliability. Further, as compared with the conventional construction in which an optical system for observing the scale on the lens barrel is also provided on the camera body side, no special limitation is imposed on the location of the light-receiving element, that is, no special consideration need be given to the erect position, the inverted position and the visibility of the image and this leads to a very simple and inexpensive construction of the optical system itself. The electrical processing system connected with the light-receiving element can also be simply made into an IC by the existing technique and this means an advantage in terms of both space and cost. | A lens information introducing device in a camera comprises n bits of code patterns provided on a lens and photoelectrically legible, optical means for introducing the code patterns into a camera body and imaging the same at a predetermined position, and photoelectric converter means disposed at the predetermined position and having n photoelectric converting elements corresponding to the code patterns and being effective to produce a digital electrical signal corresponding to the lens information on the basis of the photoelectric signals produced by the photoelectric converting elements. | 6 |
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