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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to U.S. Provisional Application No. 61/521,443, filed on Aug. 9, 2011, and entitled “Tank for an all terrain vehicle,” the disclosure of which is incorporated by reference in its entirety.
BACKGROUND
[0002] The present application relates to personal off-road vehicles. More particularly, the application discloses a small off-road vehicle, commonly referred to as a utility terrain vehicle, with improvements geared towards applications for military, law enforcement, and emergency personnel.
[0003] Over the last several years, the popularity of utility terrain vehicles (also referred to as “UTVs”) has greatly increased. UTVs are practical and versatile, as the vehicle may be used for work or leisure related tasks. The compact nature, mobility, and traction of UTVs means the vehicles are capable of traversing all sorts of surfaces, from the relatively smooth surfaces of paved roadways to rough, uneven terrains, including rocky areas, woodland trails, wetlands, and sand dunes. UTVs are also typically designed to pull or push various objects such as a trailer or a snow-plow.
[0004] A typical UTV is a personal vehicle and may contain side by side seats. Such a vehicle comprises four or more wheels mounted to a frame, the front wheels being steerable. A fuel tank and a seat are disposed on an upper portion of the frame. The engine, which represents one of the heaviest components of the vehicle, is typically mounted in a central portion of the vehicle. The engine location is specifically chosen to ensure a proper weight distribution. If the engine is water cooled, a radiator will be provided in front of the engine. The fuel tank is adjacent the engine.
[0005] While such a configuration provides vehicles with performance levels that are more than adequate, there are nonetheless many disadvantages associated with it. For example, if the vehicle is to be used for special utility purposes, or by emergency personnel or military personnel, additional vehicle storage, stability, and utility are required from what is typically found in a standard model known in the art. Particularly, absent in the prior art is a system with a large liquid holding tank.
SUMMARY
[0006] A first embodiment includes a utility terrain vehicle having four or more wheels, a frame held above the ground by the wheels, and a liquid storage tank. The liquid storage tank is attached to the frame to create a low center of gravity for the utility terrain vehicle.
[0007] A second embodiment includes a utility terrain vehicle having two front tires and two rear tires, a vehicle frame held above the ground by the front tires and the rear tires, one or more seats, and a liquid storage tank. The seats have a seat frame, a lower seating surface, and an upper seating surface. The liquid storage tank is located above the vehicle frame and below the seat frame.
[0008] A third embodiment includes a utility terrain vehicle having two front tires and two rear tires, a vehicle frame held above the ground by the front tires and the rear tires, a subframe attached to the vehicle frame to provide additional support to the vehicle, a first seat and a second seat, a flatbed, a pump carried on the flatbed, a liquid storage tank, and an inlet to the liquid storage tank. The first and second seats have a combined seat frame, a lower seating surface, and an upper seating surface. The liquid storage tank is located above the vehicle frame and below the lower seating surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side elevation view of a tank for a utility terrain vehicle (UTV).
[0010] FIG. 2 is a perspective view of the tank from the passenger's side of the vehicle.
[0011] FIG. 3 is a perspective view of the tank from the driver's side of the vehicle.
[0012] FIG. 4 is a side elevation view of the tank.
[0013] FIG. 5 is a rear perspective view of the tank from the driver's side of the vehicle.
[0014] FIG. 6 is perspective view of a multi-passenger UTV with a specialized tank.
[0015] FIG. 7 is a perspective view of a tank beneath the seats of an UTV.
[0016] FIG. 8 is a rear perspective view of the tank from the driver's side of the vehicle with a portion of the seat removed.
[0017] FIG. 9 is a front perspective view of the tank from the driver's side of the vehicle with the seat removed.
[0018] FIG. 10 is front elevation view of the tank for the vehicle with a portion of the seat removed.
[0019] FIG. 11 is a front perspective view of the tank from the passenger's side of the vehicle with the seat removed.
[0020] FIG. 12 is a passenger side elevation view of a multi-passenger UTV.
[0021] FIG. 13 is a passenger side elevation view of the fuel tank for an UTV.
[0022] FIG. 14 is a side elevation view of the UTV tank.
[0023] FIG. 15 is a top plan view of a UTV tank beneath seating for the vehicle.
[0024] FIG. 16 is a passenger's side perspective view of the UTV tank beneath seating for the vehicle.
[0025] FIG. 17 is a driver's side perspective view of the UTV tank beneath seating for the vehicle.
[0026] FIG. 18 is a perspective view of the tank and rear passenger seating area.
[0027] FIG. 19 is a top plan view of the tank.
[0028] FIG. 20 is a side plan view of the tank.
[0029] FIG. 21 is a perspective view of the tank.
[0030] FIG. 22 is a front elevation view of the tank.
DETAILED DESCRIPTION
[0031] FIG. 6 is a perspective view of multi-passenger UTV 10 with liquid tank 30 . FIG. 12 is a passenger side elevation view of multi-passenger UTV 10 . UTV 10 includes front wheels 12 , rear wheels 14 , main body portion 16 , cage 18 , flatbed 20 , gas tank 21 , pump 22 , cab 24 , seat frame 26 , upper seat 28 , lower seat 29 (not shown), liquid tank 30 , front footrest 32 , rear footrest 34 , liquid tank inlet 36 , flatbed tank 38 , a frame, and a subframe. Front wheels 12 are capable of being steered and front wheels 12 and rear wheels 14 are attached to a front axle and rear axle, respectively (not shown). Front wheels 12 and rear wheels 14 are part of a drive train system. Each axle is mounted on a suspension system relative to a frame. The frame supports the drive train system and an engine, where the engine actuates the drive train system. Main body portion 16 covers the frame. The frame is reinforced with a subframe to support the additional weight added to UTV 10 from liquid tank 30 .
[0032] Other elements of UTV 10 include various support structures, such as flatbed 20 and cage 18 . Cage 18 is connected to main body portion 16 and assists in preventing injury to passengers from passing branches or similar obstacles, as well as acting as a support in the event of a vehicle rollover. Cab 24 is defined by main body portion 16 and cage 18 . Flatbed 20 extends rearward of cab 24 . Flatbed 20 supports pump 22 , flatbed tank 38 , and liquid tank inlet 36 . Pump 22 and liquid tank inlet 36 are connected to tank 30 with hoses. Liquid tank inlet 36 has the capacity to retain some liquid and is thus capable of acting as a surge when filing liquid tank 30 . Liquid tank inlet 36 creates a pressure differential between liquid tank 30 and liquid tank inlet 36 so that the liquid in liquid tank inlet 36 moves through the hose into liquid tank 30 . UTV 10 also includes gas tank 21 located rearward of liquid tank 30 on the passenger's side, to supply gas to the engine. UTV 10 further includes seat frame 26 , upper seat 28 , and lower seat 29 . Seat frame 26 is disposed on specialized tank 30 , and upper seat 28 and lower seat 29 are attached to seat frame 26 . Upper seat 28 provides support for the backs of the driver and passengers and lower seat 29 provides support for the sitting of the driver and passengers.
[0033] In the embodiment shown, UTV 10 includes three seats: a driver's seat, a first passenger's seat next to the driver's seat, and a second passenger's seat rearward of the driver's seat. A portion of flatbed 20 extends behind the first passenger's seat and next to the second passenger's seat. In other embodiments, UTV 10 may include more seats or fewer seats. Front footrest 32 is forward of liquid tank 30 and provides a place for the driver and first passenger to rest their feet. Rear footrest 34 is located rearward of liquid tank 30 behind the driver's seat and provides a place for the second passenger to rest their feet.
[0034] FIG. 21 is a perspective view of liquid tank 30 . FIG. 19 is a top plan view of liquid tank 30 . FIG. 22 is a front elevation view of liquid tank 30 . FIG. 20 is a side plan view of liquid tank 30 . Tank 30 includes forward end 42 , aft end 44 , first side 46 , second side 48 , third side 54 , top side 50 , bottom side 52 , slanted aft end 56 , and curved edges 58 A and 58 B. Forward end 42 is connected to top side 50 , bottom side 52 , and curved edges 58 A and 58 B. Second side 48 is connected to curved edge 58 B, top side 50 , aft end 44 , and bottom side 52 . Aft end 44 is connected to top side 50 , second side 48 , bottom side 52 , and third side 54 . Second side 46 is connected to top side 50 , curved edge 58 A, slanted aft end 56 , and bottom side 52 . Third side 54 is connected to aft end 44 , top side 50 , bottom side 52 , and slanted aft end 56 . Slanted aft end 56 is connected to top side 50 , bottom side 52 , first side 46 , and third side 54 . Top side 50 is connected to forward end 42 , curved edges 58 A and 58 B, second side 48 , aft end 44 , third side 54 , slanted side 56 , and first side 46 . Bottom side 52 is connected to forward end 42 , curved edges 58 A and 58 B, second side 48 , aft end 44 , third side 54 , slanted side 56 , and first side 46 .
[0035] In the embodiment shown, tank 30 has the following dimensions: height H of tank 30 is 15 inches; width W p of tank 30 on the first passenger's side is 32 inches; width W b of tank 30 on the driver's side bottom is 15 inches; width W t of tank 30 on the driver's side top is 21 inches; forward length L f of tank 30 is 59 inches; and rear length L r of tank 30 behind the passenger's seat is 37 inches. The dimensions of tank 30 can be adjusted based on the size and arrangement of UTV 10 . For instance, in the case that UTV 10 does not have a second passenger's seat, tank 30 is capable of being shaped to fill the space that is left open for footrest 34 in the embodiment shown.
[0036] Tank 30 extends under the driver's seat and passenger's seat, and rearward of the passenger's seat under a portion of flatbed 20 . The space behind the driver's seat is left open for rear footrest 34 . This allows the second passenger to have leg room when they are riding on UTV 10 . The second passenger's leg room is further expanded with slanted aft end 56 . Slanted aft end 56 allows tank 30 to extend fully rearward under the driver's seat, while at the same time providing more open space for rear footrest 34 . Top side 50 of tank 30 needs to extend fully rearward under the driver's seat to support seat frame 26 .
[0037] Tank 30 is shaped to be placed under seat frame 26 on UTV 10 . Tank 30 is capable of supporting the weight of seat frame 26 , upper seat 28 , lower seat 29 , a portion of flatbed 20 , and the sitting weight of an operator and passenger. In the embodiment shown, tank 30 is made out of aluminum, although any material capable of supporting the weight and holding liquid can be used. The materials best suited for supporting the additional weight are rigid materials with a high tensile strength, and the materials best suited for holding liquid are rigid and non-corrosive materials. Tank 30 has the capacity to hold over 100 gallons of liquid.
[0038] Tank 30 as designed and as located on UTV 10 provides many benefits, especially when UTV 10 is being used for military, emergency, medical, and fire protection purposes. In the prior art, liquid storage tanks are carried on flatbeds of a UTV. Carrying a liquid storage tank on a flatbed greatly raises the center of gravity of the UTV, which decreased the handling of the vehicles and increased the possibility of a roll-over. Placing tank 30 under seat frame 26 gives UTV 10 a low center of gravity, which improves the handling of UTV 10 . When tank 30 is empty, the center of gravity of UTV 10 is similar to the center of gravity of UTV 10 without tank 30 . When tank 30 is full, the center of gravity is still lower than the height of the tank and thus low on the vehicle, which reduces the risk of a roll-over. Placing tank 30 under seat frame 26 also distributes the weight of the liquid more evenly across front tires 12 and rear tires 14 , which again results in improved handling.
[0039] Placing tank 30 under seat frame 26 allows for additional equipment to be carried on flatbed 20 of UTV 10 . Opening up this space increases the effectiveness of UTV 10 as a vehicle that can be used in fire fighting. Tank 30 allows for a larger amount of water to be carried on UTV 10 and leaves flatbed 20 open to carry a pump, hose, and other firefighting tools. Opening up flatbed 20 also increases the effectiveness of using UTV 10 for emergency purposes. Flatbed 20 is capable of holding a stretcher and other medical equipment. The configuration of UTV 10 also allows a paramedic to tend to a patient while UTV 10 is moving. Tank 30 is also capable of holding additional fuel for UTV 10 , which greatly increases the travel distance of UTV 10 . UTV 10 can also hold fire suppressant materials, chemical mixtures for pest control, and any other liquid.
[0040] FIG. 9 is a front perspective view of tank 30 from the driver's side of UTV 10 with lower seat 29 removed. FIG. 10 is front elevation view of tank 30 for UTV 10 with lower seat 29 removed. FIG. 11 is a front perspective view of tank 30 from the passenger's side of UTV 10 with lower seat 29 removed. Tank 30 is located in cab 24 of UTV 10 under seat frame 26 . In the prior art, seat frame 26 was placed on top of a plastic support system with a cavity under the driver's seat to store small equipment. In order to maximize the amount of liquid that could be carried on UTV 10 , the prior plastic support system has been removed and replaced with tank 30 . Tank 30 extends fully from the driver's side of UTV 10 to the passenger's side of UTV 10 , as evident in FIG. 10 . A part of the remaining plastic system can be seen as plastic front 70 in FIGS. 9 and 11 . In the prior art, plastic front 70 wrapped around the edges of tank 30 and extended fully rearward. In order to maximize the span of tank 30 from the driver's side to the passenger's size, the edges and corners of plastic front 70 have been removed.
[0041] FIG. 7 is a perspective view of tank 30 beneath seat frame 26 of UTV 10 . FIG. 13 is a passenger side elevation view of fuel tank 21 and tank 30 for UTV 10 . Tank 30 extends fully from the driver's side to the passenger's side of UTV 10 . As seen in FIG. 7 , tank 30 extends rearward of the driver's seat to the second passenger's seat and rear footrest 34 . As seen in FIG. 13 , tank 30 extends rearward of the passenger's seat underneath flatbed 20 . In the prior art, a third passenger's seat was provided in place of flat bed 20 on top of gas tank 21 . Flatbed 20 has been extended forward over gas tank 21 here so a stretcher can be placed on flatbed 20 . The stretcher will extend forward behind the first passenger's seat so that a passenger riding in the second passenger's seat can attend to a patient on the stretcher while UTV 10 is in operation. Further, removing the third passenger's seat allowed for tank 30 to extend further behind the first passenger's seat toward gas tank 21 . This further maximized the amount of liquid that can be carried in tank 30 .
[0042] FIG. 17 is a driver's side perspective view of tank 30 beneath seat frame 26 . FIG. 16 is a passenger's side perspective view of tank 30 beneath seat frame 26 . FIG. 15 is a top plan view of tank 30 beneath seat frame 26 . Seat frame 26 is bolted to tank 30 in the embodiment shown, although other means of attaching the two can be used including any type of fastener. As stated previously, in the prior art seat frame 26 was attached to a plastic support system. In the present invention, seat frame 26 has been modified to attach to tank 30 . These modifications include adjusting the attachment means on seat frame 26 to fit with tank 30 , and removing the two side portions of plastic front 70 so that the space under seat frame 26 can be optimized.
[0043] FIG. 8 is a rear perspective view of tank 30 from the driver's side of UTV 10 with lower seat 29 removed. FIG. 18 is a perspective view of tank 30 and a rear passenger seating area. On the first passenger's side, tank 30 extends rearward underneath flatbed 20 . On the driver's side, tank 30 extends rearward until slanted aft end 56 . Slanted aft end 56 mimics the shape of the prior plastic support system under seat frame 26 . Slanted aft end 56 and rear footrest 34 are designed to provide leg and foot space for a second passenger. The design of slanted aft end 56 also allows tank 30 to extend fully rearward under the driver's seat to support seat frame 26 , which again allows the capacity of tank 30 to be maximized. Leaving space for the second passenger's seat also allows a passenger riding on the second passenger's seat to tend to a patient on a stretcher on flatbed 20 , as flatbed 20 extends forward next to the second passenger's seat.
[0044] FIG. 3 is a front perspective view of tank 30 from the driver's side of UTV 10 .
[0045] FIG. 2 is a perspective view of tank 30 from the passenger's side of UTV 10 . FIG. 3 and FIG. 2 show tank 30 extending fully across UTV 10 from the driver's side to the passenger's side when lower seat 29 is attached to seat frame 26 . As evident, the location and arrangement of tank 30 allows leg and foot space for the driver and first passenger, similar to the prior art, while maximizing the capacity of tank 30 .
[0046] FIG. 4 is a side elevation view of tank 30 . FIG. 1 is a side elevation view of tank 30 for UTV 10 . FIG. 4 and FIG. 1 show how tank 30 extends rearward of the driver's seat to the second passenger's seat and rearward of the first passenger's seat underneath flatbed 20 to gas tank 21 with lower seat 29 attached to seat frame 26 . As discussed above, this arrangement maximizes the capacity of tank 30 . FIG. 1 also shows stretcher 72 on flatbed 20 . Stretcher 72 is located beside the second passenger's seat, so that a passenger riding on the second passenger's seat can tend to a patient while UTV 10 is in operation.
[0047] FIG. 5 is a rear perspective view of tank 30 from the driver's side of UTV 10 . FIG. 5 shows the leg and foot room that is maintained for the second passenger's seat, while at the same time maximizing the capacity of tank 30 . FIG. 14 is a side elevation view of tank 30 and gas tank 21 . FIG. 14 shows how tank 30 extends rearward of the first passenger's seat to gas tank 21 underneath flatbed 20 .
[0048] While the invention has been described with reference to an exemplary embodiment(s), 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. In addition, 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(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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A first embodiment includes a utility terrain vehicle having four or more wheels, a frame held above the ground by the wheels, and a liquid storage tank. The liquid storage tank is attached to the frame to create a low center of gravity for the utility terrain vehicle.
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FIELD OF THE INVENTION
This invention relates to an α-amino-N-allylamidino nitrobenzene compound and process for its preparation.
BACKGROUND OF THE INVENTION
The photographic art employs couplers to provide colored dyes in image reproductions. The couplers react imagewise with color developer to produce the desire reproduction. One of the couplers useful for this purpose is a pyrazolo[1,5-b][1,2,4]triazole compound that has found utility for forming a magenta dye in the usual system employing subtractive primaries.
Such couplers and methods of making them were originally disclosed in U.S. Pat. No. 4,621,046. Other methods have been disclosed in U.S. Pat. Nos. 4,705,863 and 6,020,498. The latter patent suggests the use of certain N-alkylamidino nitrobenzene derivatives for synthesizing intermediates in the process. It is desirable, however to provide alternative processes for preparing the desired compounds, especially processes that can provide improved yields.
SUMMARY OF THE INVENTION
The invention provides a process comprising reacting an N-allylimino nitrobenzene compound with a diaminodinucleophile to form an α-amino-N-allylamidino nitrobenzene compound and also provides the compound itself as a composition of matter.
The invention provides a useful process for synthesizing useful compounds employing allyl groups. Embodiments of the invention can provide improved yields compared to prior art processes.
DETAILED DESCRIPTION OF THE INVENTION
The invention is summarized above. The process of the invention is generally shown in reaction scheme 3 in the following scheme.
In reaction 3, an N-allylimino nitrobenzene compound is reacted with a diaminodinucleophile to form an α-amino-N-allylamidino nitrobenzene compound. Suitably, the reaction is carried out in the presence of a solvent that is inert under the reaction conditions. Useful solvents may be selected from the group consisting of C 1 to C 8 aliphatic alcohols, chlorinated or unchlorinated aromatic hydrocarbons such as toluene, the xylenes, monochlorobenzene or dichlorobenzenes, chlorinated or unchlorinated aliphatic hydrocarbons, ethers such as tetrahydrofuran, and esters such as ethyl acetate or isopropyl acetate. Preference is given to using alcohols, in particular isopropyl alcohol. In particular the reaction may be carried out using a mixture of toluene and isopropyl alcohol where the 3-tert-butyl-5-aminopyrazole in an isopropyl alcohol solution is added to a toluene solution of the amidine.
The reaction is exothermic and conveniently carried out at a temperature ranging from −10° C. to +30° C. and desirably from 0 to 15° C.
The reaction is carried out with the diaminodinucleophile being present in stoichiometric quantity or in excess compared to the α-amino-N-allylamidino nitrobenzene compound, with an excess of up to 0.5 mols/mol and a range of 1 to 1.25 mols/mol preferred. The compound is one having at least two nucleophilic nitrogen atoms and may include a ring compound such as an 3-tert-butyl-5-aminopyrazole.
Reaction 3 is typically described using the above captioned equation and the following limitations:
Z and X may independently be halogen, alkoxy, aryloxy, alkylthio, arylthio or heterocyclic groups;
R 1 , R 2 , and R 3 may independently be hydrogen, halogen, alkoxy, aryloxy, alkylthio, arylthio, (cyclo-)alkyl, alkenyl, alkynyl, silyl or heterocyclic groups; provided that R 1 , R 2 , and R 3 may also be contained within a carbocyclic or heterocyclic aromatic or non-aromatic ring system;
R 4 and R 5 may independently be hydrogen, halogen, alkoxy, aryloxy, alkylthio, arylthio, alkyl, alkenyl, alkynyl, silyl or heterocyclic groups; provided that R 4 and R 5 may also be contained within a carbocyclic or heterocyclic aromatic or non-aromatic ring system; and
Y is a leaving group such as hydroxy, halogen, alkoxy, aryloxy, acetoxy, siloxy, mesylate or tosylate. The preferred leaving groups are mesylate or tosylate.
The reaction may be represented by the following reaction 3
wherein
Z and X are independently selected from halogen, alkoxy, aryloxy, alklthio, arylthio and heterocyclic akyl groups and n is 0 to 4;
R 1 , R 2 , R 3 are independently selected from H, halogen, alkoxy, aryloxy, alkylthio, arylthio, alkyl, saturated or unsaturated cyclohydrocarbyl, heterocylic, aroyl, alkenyl, alkynyl, and silyl groups, provided that R 1 , R 2 , R 3 may also be contained within a ring system; and
R 4 and R 5 are independently selected from H, halogen alkoxy, aryloxy, alkylthio, arylthio, alkyl, saturated or unsaturated cyclohydrocarbyl, hetereocylic, aromatic, aryl, alkenyl, alkynyl, silyl, provided that R 4 and R 5 may also be contained within a ring system.
The starting amide can be prepared using known methods, for example where the amine can be reacted with an acyl halide, an anhydride, an ester, or direct coupling with a carboxylic acid. (Woodcock, D. J. in Patai The Chemistry of the Amino Group ; Wiley: N.Y., 1968, p. 440.)
In order to carry out step 2, use is generally made of a chlorinating agent such as, in particular, thionyl chloride (SOCl 2 ), phosphorus pentachloride (PCl 5 ), phosphorus oxychloride (POCl 3 ), phosgene (COCl 2 ), or oxalyl chloride (COCl) 2 , or one of their mixtures as more fully described in:
SOCl 2 Lawson, A.; Miles, D. H. ; J Chem Soc [JCSOA9] 1959, 2865.
POCL 3 Harris, R. L. N.; Synthesis [SYNTBF] 1980 (10), 841.
PCl 5 Madronero, R.; Vega, S.; Synthesis [SYNTBF] 1987 (7), 628.
(COCl) 2 Fujisawa, T.; Mori, T.; Sato, T.; Tetrahedron Lett [TELEAY] 1982, 23 (48), 5059.
Preference is given to using thionyl chloride. The chlorinating agent is employed in stoichiometric quantity or in excess. For reasons of economy, the quantity of chlorinating agent is preferably from 1 to 1.25 mol per mol of amide. The reaction can be carried out without solvent, with the chlorinating agent then serving as the solvent, or in the presence of a solvent or a mixture of solvents which are inert under the reaction conditions and which are selected from chlorinated or unchlorinated aromatic hydrocarbons such as toluene, the xylenes, monochlorobenzene or the dichlorobenzenes, or chlorinated or unchlorinated aliphatic hydrocarbons such as ethane or dichloromethane. Toluene is very suitable.
The temperature of this reaction is generally between 25° C. and the reflux temperature of the solvent. When toluene is the chosen solvent and the chlorinating agent is thionyl chloride, the temperature is, in particular, between 70° C. and 110° C.
Catalysts such as N,N-dialkylated amides, in particular dialkylated formamides whose alkyl groups possess from 1 to 8 carbon atoms, such as N,N-dimethylformamide and, more especially, N,N-dibutylformamimde, can be added in order to accelerate the reaction. In general, the chlorination lasts between 2 and 15 hours. Once the reaction has finished, it is not necessary to isolate the chloroimine that is formed from the reaction medium.
General conditions for forming the oxime are described in the following literature:
C. G. McCarty, “ Chemistry of the Carbon - Nitrogen Double Bond ” Ed. S. Patai, Interscience, New York (1970), pp 408-439;
J. A. Gautier, M. Miocque and C. C. Farnoux, “The Chemistry of Amidines and Imidates”, Ed. S. Patai, Interscience, New York, (1975) pp 313-314.
Steps 5 and 6 are ring closure reactions and are more fully described in U.S. Pat. No. 4,705,863.
Unless otherwise specifically stated, use of the term “group”, “substituted” or “substituent” means any group or radical other than hydrogen. Additionally, when reference is made in this application to a compound or group that contains a substitutable hydrogen, it is also intended to encompass not only the unsubstituted form, but also its form further substituted with any substituent group or groups as herein mentioned, so long as the substituent does not destroy properties necessary for the intended utility. Suitably, a substituent group may be halogen or may be bonded to the remainder of the molcule by an atom of carbon, silicon, oxygen, nitrogen, phosphorous, or sulfur. The substituent may be, for example, halogen, such as chloro, bromo or fluoro; nitro; hydroxyl; cyano; carboxyl; or groups which may be further substituted, such as alkyl, including straight or branched chain or cyclic alkyl, such as methyl, trifluoromethyl, ethyl, t-butyl, 3-(2,4-di-t-pentylphenoxy) propyl, cyclohexyl, and tetradecyl; alkenyl, such as ethylene, 2-butene; alkoxy, such as methoxy, ethoxy, propoxy, butoxy, 2-methoxyethoxy, sec-butoxy, hexyloxy, 2-ethylhexyloxy, tetradecyloxy, 2-(2,4-di-t-pentylphenoxy)ethoxy, and 2-dodecyloxyethoxy; aryl such as phenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, naphthyl; aryloxy, such as phenoxy, 2-methylphenoxy, alpha- or beta-naphthyloxy, and 4-tolyloxy; carbonamido, such as acetamido, benzamido, butyramido, tetradecanamido, alpha-(2,4-di-t-pentyl-phenoxy)acetamido, alpha-(2,4-di-t-pentylphenoxy)butyramido, alpha-(3-pentadecylphenoxy)-hexanamido, alpha-(4-hydroxy-3-t-butylphenoxy)-tetradecanamido, 2-oxo-pyrrolidin-1-yl, 2-oxo-5-tetradecylpyrrolin-1-yl, N-methyltetradecanamido, N-succinimido, N-phthalimido, 2,5-dioxo-1-oxazolidinyl, 3-dodecyl-2,5-dioxo-1-imidazolyl, and N-acetyl-N-dodecylamino, ethoxycarbonylamino, phenoxycarbonylamino, benzyloxycarbonylamino, hexadecyloxycarbonylamino, 2,4-di-t-butylphenoxycarbonylamino, phenylcarbonylamino, 2,5-(di-t-pentylphenyl)carbonylamino, p-dodecyl-phenylcarbonylamino, p-tolylcarbonylamino, N-methylureido, N,N-dimethylureido, N-methyl-N-dodecylureido, N-hexadecylureido, N,N-dioctadecylureido, N,N-dioctyl-N′-ethylureido, N-phenylureido, N,N-diphenylureido, N-phenyl-N-p-tolylureido, N-(m-hexadecylphenyl)ureido, N,N-(2,5-di-t-pentylphenyl)-N′-ethylureido, and t-butylcarbonamido; sulfonamido, such as methylsulfonamido, benzenesulfonamido, p-tolylsulfonamido, p-dodecylbenzenesulfonamido, N-methyltetradecylsulfonamido, N,N-dipropylsulfamoylamino, and hexadecylsulfonamido; sulfamoyl, such as N-methylsulfamoyl, N-ethylsulfamoyl, N,N-dipropylsulfamoyl, N-hexadecylsulfamoyl, N,N-dimethylsulfamoyl; N-[3-(dodecyloxy)propyl]sulfamoyl, N-[4-(2,4-di-t-pentylphenoxy)butyl]sulfamoyl, N-methyl-N-tetradecylsulfamoyl, and N-dodecylsulfamoyl; carbamoyl, such as N-methylcarbamoyl, N,N-dibutylcarbamoyl, N-octadecylcarbamoyl, N-[4-(2,4-di-t-pentylphenoxy)butyl]carbamoyl, N-methyl-N-tetradecylcarbamoyl, and N,N-dioctylcarbamoyl; acyl, such as acetyl, (2,4-di-t-amylphenoxy)acetyl, phenoxycarbonyl, p-dodecyloxyphenoxycarbonyl methoxycarbonyl, butoxycarbonyl, tetradecyloxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl, 3-pentadecyloxycarbonyl, and dodecyloxycarbonyl; sulfonyl, such as methoxysulfonyl, octyloxysulfonyl, tetradecyloxysulfonyl, 2-ethylhexyloxysulfonyl, phenoxysulfonyl, 2,4-di-t-pentylphenoxysulfonyl, methylsulfonyl, octylsulfonyl, 2-ethylhexylsulfonyl, dodecylsulfonyl, hexadecylsulfonyl, phenylsulfonyl, 4-nonylphenylsulfonyl, and p-tolylsulfonyl; sulfonyloxy, such as dodecylsulfonyloxy, and hexadecylsulfonyloxy; sulfinyl, such as methylsulfinyl, octylsulfinyl, 2-ethylhexylsulfinyl, dodecylsulfinyl, hexadecylsulfinyl, phenylsulfinyl, 4-nonylphenylsulfinyl, andp-tolylsulfinyl; thio, such as ethylthio, octylthio, benzylthio, tetradecylthio, 2-(2,4-di-t-pentylphenoxy)ethylthio, phenylthio, 2-butoxy-5-t-octylphenylthio, and p-tolylthio; acyloxy, such as acetyloxy, benzoyloxy, octadecanoyloxy, p-dodecylamidobenzoyloxy, N-phenylcarbamoyloxy, N-ethylcarbamoyloxy, and cyclohexylcarbonyloxy; amine, such as phenylanilino, 2-chloroanilino, diethylamine, dodecylamine; imino, such as 1 (N-phenylimido)ethyl, N-succinimido or 3-benzylhydantoinyl; phosphate, such as dimethylphosphate and ethylbutylphosphate; phosphite, such as diethyl and dihexylphosphite; a heterocyclic group, a heterocyclic oxy group or a heterocyclic thio group, each of which may be substituted and which contain a 3 to 7 membered heterocyclic ring composed of carbon atoms and at least one hetero atom selected from the group consisting of oxygen, nitrogen and sulfur, such as 2-furyl, 2-thienyl, 2-benzimidazolyloxy or 2-benzothiazolyl; quaternary ammonium, such as triethylammonium; and silyloxy, such as trimethylsilyloxy.
If desired, the substituents may themselves be further substituted one or more times with the described substituent groups. The particular substituents used may be selected by those skilled in the art to attain the desired desirable properties for a specific application and can include, for example, hydrophobic groups, solubilizing groups, blocking groups, and releasing or releasable groups. When a molecule may have two or more substituents, the substituents may be joined together to form a ring such as a fused ring unless otherwise provided.
EXAMPLES
Example 1
Step 1′ A 2-L, three-necked, round-bottomed flask equipped with a magnetic stirring bar, a 24/40 adapter fitted with a thermometer, an argon inlet adapter, and a 250-mL pressure-equalizing addition funnel fitted with a glass stopper was purged with argon. The flask was charged with 3-nitrobenzoyl chloride (J) 112.0 g (0.6035 mol) and 850 mL of dichloromethane, and then cooled with an ice-water bath. The addition funnel was charged with triethylamine 93.0 mL (0.667 mol) and allylamine (K) 50.0 mL (0.666 mol), and this solution was then added dropwise to the reaction mixture over ca. 2.5 h while the reaction temperature was maintained at 0-4° C. The addition funnel was then rinsed with two 5-mL portions of dichloromethane. The resulting turbid pale orange-pink reaction mixture was allowed to slowly warm to and stir at room temperature. After 16.5 h, 600 mL of 1N HCL was added to the turbid bright yellow solution over 30 sec and the biphasic mixture was transferred to a separatory funnel. The reaction flask was rinsed with three 100-mL portions of 1:1 CH 2 Cl 2 : 1N HCl and the organic phase was separated and washed with 500 mL of saturated sodium chloride solution, dried over sodium sulfate, filtered, and concentrated under reduced pressure to afford 122 g (98% crude yield) of a pale yellow solid. The crude product was recrystallized from 450 mL of toluene to afford 113 g (91 % yield) of N-allyl-3-nitrobenzamide (L) as a powdery pale yellow solid.
1 H NMR spectrum (CDCl 3 , 300 MHz), δ (ppm):4.11 (tt, J=6.0, 3.0 Hz, 2H), 5.21 (dq, J=10.5, 3.0 Hz, 1H), 5.28 (dq, J=16.5, 3.0 Hz, 1H), 5.87-6.00 (m, 1H), 6.62 (br s, 1H), 7.64 (appar. t, J=9.0 Hz, 1H), 8.18 (appar. dt, J=9.0, 1.5 Hz, 1H), 8.35 (ddd, J=6.0, 3.0, 1.5 Hz, 1H), 8.60 (appar. t, J=3.0 Hz, 1H). LRMS m/z 205 (M − ).
Step 2′ A 50-mL, one-necked, round-bottomed flask equipped with a magnetic stirring bar and a reflux condenser fitted with an argon inlet adapter was evacuated and purged with argon three times and then maintained under an atmosphere of argon during the course of the reaction. The flask was charged with N-allyl-3-nitrobenzamide (L) 5.15 g (0.025 mol) and thionyl chloride 12.2 mL (0.167 mol), and then the clear pale yellow reaction mixture was heated to reflux over 50 min. After stirring at reflux for 2.25 h, the oil bath was removed and the clear yellow reaction mixture was allowed to cool to room temperature over 45 min. The magnetic stirring bar was removed and rinsed along with the condenser using a total of ca. 10 mL toluene. The yellow solution was concentrated at reduced pressure to afford the chloroimine M as a dark yellow liquid. The chloroimine M was treated with five successive 6-mL portions of toluene and each time the toluene was removed under reduced pressure. The product was used in the next step without purification.
Step 3′ A 50-mL, one-necked, round-bottomed flask containing the chloroimine M equipped with a magnetic stirring bar and a 30-mL pressure-equalizing addition fimnel fitted with an argon inlet adapter was purged with argon. The flask was charged with 6 mL of toluene and then cooled with an ice-water bath. Then a solution of 3-tert-butyl-5-aminopyrazole (N) 3.45 g (0.025 mol) in 9 mL of isopropyl alcohol was added dropwise via addition funnel over 1.25 h. The addition funnel was then rinsed with two 5-mL portions of isopropyl alcohol, the ice-water bath was removed and the clear orange-yellow reaction mixture was stirred at room temperature for 19 h and then the N-allylamidine O in toluene-isopropyl alcohol was used in the next step without purification. Preparation, isolation, and characterization of this intermediate, N-allylamidine O, can be found in Example 5.
Step 4′ A 100-mL, three-necked, round-bottomed flask equipped with a magnetic stirring bar, a reflux condenser fitted with an argon inlet adapter, and two glass stoppers was evacuated and purged with argon three times and then maintained under an atmosphere of argon during the course of the reaction. The flask was charged with the solution of N-allylamidine O in toluene-isopropyl alcohol prepared in the previous reaction and a total of 10 mL of methanol was used to aid in the transfer. The flask was then charged with hydroxylamine hydrochloride 3.63 g (0.052 mol) and the slightly turbid pale orange reaction mixture was heated to 40° C. over 45 min followed by the addition of sodium acetate 1.95 g (0.024 mol) in one portion. The resulting yellow heterogeneous reaction mixture was stirred at 40-48° C. for 20.5 h. The reaction mixture was then partially concentrated under reduced pressure using an aspirator followed by the addition of 25 mL total of ca. 50° C. water to the viscous yellow slurry in portions over ca. 1 min. After stirring at 40-44° C. for ca. 1.5 h, the oil bath was removed and the biphasic yellow solution was allowed to cool to room temperature over 55 min. The biphasic yellow-green solution was diluted with 25 mL of ethyl acetate and transferred to a separatory funnel with the aid of three 10-mL portions of 1:1 EtOAc:H 2 O. The green-yellow organic phase was separated and washed with 25 mL of water, 25 mL of saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure. The resulting yellow-green glass was treated with five successive 50-mL portions of dichloromethane and each time the dichloromethane was removed under reduced pressure. Further concentration under high vacuum afforded 7.3 g (96% crude yield based upon the starting amide) of the amidoxime P as a yellow-green glass which was 86% pure by LC. By multiplying the crude yield times the LC purity a final yield of 83% was obtained. 1 H NMR and mass spec were consistent with the product.
1 H NMR spectrum (DMSO, 300 MHz), δ (ppm): 1.12 (s, 9H), 5.45 (s, 1H), 7.56 (appar. t, J=7.5 Hz, 1H), 7.76 (appar. d, J=9.0 Hz, 1H), 8.06 (appar. t, J=3.0 Hz, 1H), 8.08 (s, 1H), 8.13 (appar. d, J=6.0 Hz, 1H), 10.60 (s, 1H), 11.70 (br s, 1H). LRMS m/z 302 (M − ).
Example 2
Step 1′ A 3-L, three-necked, round-bottomed flask equipped with a mechanical stirrer, a nitrogen inlet adapter, and a 500-mL pressure-equalizing addition finnel fitted with a glass stopper was purged with nitrogen. The flask was charged with allylamine (K) 33.9 g (0.593 mol), 50 mL of ethyl acetate, triethylaamine 60.0 g (0.593 mol), and then cooled with an ice-water bath. The addition funnel was charged with 3-nitro-benzoyl chloride (J) 100.0 g (0.539 mol) and 230 mL ethyl acetate, and this solution was then added dropwise to the reaction mixture over 1 h while the reaction mixture was maintained at 0° C. The reaction mixture was stirred at 0° C. for 3 h and then filtered. The filtrate was transferred to a separatory finnel and washed with 150 mL of a 10% (by volume) HCl aqueous solution, 100 mL of saturated sodium chloride solution, dried over magnesium sulfate, and the solvent volume was reduced to one-third the original volume under reduced pressure. The clear solution was cooled to 0° C. overnight. The resulting yellow solid was collected by filtration and dried in a vacuum oven at 50° C. for 6 h to afford 89.4 g (80% yield) of N-allyl-3-nitrobenzamide (L) as a yellow solid.
Step 2′ A 1 -L, one-necked, round-bottomed flask equipped with a magnetic stirring bar and a reflux condenser fitted with a nitrogen inlet adapter was purged with nitrogen. The flask was charged with N-allyl-3-nitrobenzamide (L) 85.0 g (0.412 mol), thionyl chloride 383.5 g (3.22 mol), three drops of DMF, and the reaction was stirred at reflux for 2.5 h. The excess thionyl chloride was then removed under reduced pressure. The resulting chloroimine M (yellow oil) was treated with three successive 75-mL portions of toluene and each time the toluene was removed under reduced pressure. The chloroimine M was dissolved in 50 mL of toluene and used in the next step without purification.
Step 3′ A 3-L, three-necked, round-bottomed flask equipped with a mechanical stirrer, a nitrogen inlet adapter, and a 250-mL pressure-equalizing addition funnel fitted with a glass stopper was purged with nitrogen. The flask was charged with the solution of chloroimine M in 50 mL of toluene and the flask was placed in an ice-water bath. Separately, a 1 -L, one-necked, round-bottomed flask was charged with 3-tert-butyl-5-aminopyrazole (N) 61.94 g (0.445 mol) and 150 mL of toluene. The toluene was removed under reduced pressure. The resulting red oil was dissolved in 110 mL of isopropyl alcohol and transferred to the addition funnel. The solution of 3-tert-butyl-5-aminopyrazole (N) in 110 mL of isopropyl alcohol was added dropwise via addition funnel to the 0° C. solution of chloroimine M in toluene over 1.25 h while maintaining a reaction temperature of 0-10° C. The reaction mixture was stirred at 0° C. for 2 h and at the end of this time, an orange precipitate formed.
Step 4′ A 3-L, three-necked, round-bottomed flask containing the solution of N-allylamidine O in toluene-isopropyl alcohol equipped with a mechanical stirrer, a glass stopper, and a reflux condenser fitted with a nitrogen inlet adapter was purged with nitrogen. The flask was charged with 280 mL of methanol, hydroxylamine hydrochloride 57.26 g (0.824 mol), and placed in an oil bath. The reaction mixture was heated and upon reaching 45° C., sodium acetate 40.56 g (0.494 mol) was added in one portion. The reaction was stirred at 45° C. for 14 h. The reaction mixture was then cooled to room temperature and 300 mL of a 10% HCL/H 2 O was solution was added. The biphasic solution was transferred to a separatory funnel and the organic layer was recovered. The aqueous layer was extracted with two 150-mL portions of ethyl acetate. The combined organic layers were dried over magnesium sulfate and concentrated under reduced pressure. The resulting dark yellow oil was treated with three successive 1 50-mL portions of dichloromethane and each time the solvent was removed under reduced pressure. Further concentration under high vacuum afforded 102 g (80% crude yield based upon the starting amide) of the amidoxime P as a yellow solid which was 89% pure by LC. By multiplying the crude yield times the LC purity a final yield of 73% was obtained. 1 H NMR and mass spec was consistent with product data in Example 1.
Example 3
Comparative as Taught in U.S. Pat. No. 6,020,498
A 250-mL, one-necked, round-bottomed flask equipped with a magnetic stirring bar and a reflux condenser fitted with a nitrogen inlet adapter was purged with nitrogen. The flask was charged with N-propyl-3-nitrobenzamide 9.0 g (0.043 mol), thionyl chloride 40.0 g (0.336 mol), and several drops of DMF. The reaction mixture was stirred at reflux for 2 h. The excess thionyl chloride was then removed under reduced pressure. The resulting yellow oil was treated with two successive 10-mL portions of toluene and each time the toluene was removed under reduced pressure. The yellow oil was dissolved in 15 mL of toluene and used without purification. The reflux condenser was replaced with a 60-mL pressure-equalizing addition funnel and the flask was placed in an ice-water bath. The addition funnel was charged with 3-tert-butyl-5-aminopyrazole (N) 6.47 g (0.046 mol) dissolved in 35 mL of isopropyl alcohol and this solution was added dropwise via addition funnel to the 0° C. solution of chloroimine in toluene over 0.5 h. The reaction mixture was stirred at 0° C. for 5 h and then allowed to warm to 20 ° C. over 4 h. After stirring at 20° C. for an additional 3 days, approximately two-thirds of the solvent was removed under reduced pressure to afford an orange slurry.
A 250-mL, one-necked, round-bottomed flask containing the orange slurry equipped with a magnetic stirring bar and reflux condenser fitted with a nitrogen inlet adapter was purged with nitrogen. The flask was charged with 20 mL of methanol, hydroxylamnine hydrochloride 6.72 g (0.097 mol), and placed in an oil bath. The reaction mixture was heated and upon reaching 45 ° C, sodium acetate 5.75 g (0.070 mol) was added in one portion. The reaction was stirred at 45° C. for 4 days. The final TLC and LC indicated a complex mixture with three major products present. Compared to an authentic sample of the amidoxime P, LC analysis indicated a 38% yield of product P.
Example 4
The procedure as described in Example 3, where R=methyl, afforded the amidoxime P in 46% yield by LC.
TABLE I
% Yield
Example
U.S. Pat. No. 6,020,498
Allyl Modification
R
1
83%
C 3 H 5
2
73%
C 3 H 5
3
38%
C 3 H 7 -n
4
46%
CH 3
The data in Table I shows that preparation of the oxime intermediate of Example 3 following the prior art procedure taught in U.S. Pat. No. 6,020,498, gave the desired product in only 38-46% yield. Several other products were also produced during this reaction indicating competing, undesired, side reactions. In contrast, preparation of the oxime in the manner described in Examples 1 and 2 where N-allyl (i.e., Allyl Modification) was substituted for alkyl, resulted in significant increases in yields (83% and 73% respectively). No major side reactions were observed. Preparation of the 4-nitrobenzene oxime proceeded with similar yields that were comparable to the prior art.
Example 5
Synthesis of Isolated Intermediate N-allyl, N′-(3-tert-butyl-5-pyrazolyl)-4-nitrobenzamidine (O)
A 100-mL, one-necked, round-bottomed flask equipped with a magnetic stirring bar and a reflux condenser fitted with an argon inlet adapter was evacuated and purged with argon three times and then maintained under an atmosphere of argon during the course of the reaction. The flask was charged with N-allyl-3-nitrobenzamide (L) 5.15 g (0.025 mol), prepared as described previously in example 1, and thionyl chloride 12.2 mL (0.167 mol), and then the clear pale yellow reaction mixture was heated to reflux over 50 min. After 2 h, the oil bath was removed and the clear yellow reaction mixture was allowed to cool to room temperature over 25 min. The condenser was rinsed with three 1.5-mL portions of toluene and the yellow solution, containing the magnetic stirring bar, was concentrated under reduced pressure to afford the chloroimine M as a dark yellow liquid. The chloroimine M was treated with five successive 6-mL portions of toluene and each time the toluene was removed under reduced pressure. The product was used in the next step without purification.
A 100-mL, one-necked, round-bottomed flask containing the chloroimine M equipped with a magnetic stirring bar and a 30-mL pressure-equalizing addition funnel fitted with an argon inlet adapter was purged with argon. The flask was charged with 6 mL of toluene and then cooled with an ice-water bath. Then a solution of 3-tert-butyl-5-aminopyrazole (N) 3.45 g (0.025 mol) in 9 mL of isopropyl alcohol was added dropwise via addition fimnel over 1 h. The addition funnel was then rinsed with two 5-mL portions of isopropyl alcohol, the ice-water bath was removed and the clear orange-yellow reaction mixture was stirred at room temperature for ca. 5 days. The clear orange-yellow reaction mixture was then transferred to a separatory containing 100 mL of ethyl acetate and 100 mL of half-saturated sodium bicarbonate solution. The flask was rinsed with three 10-mL portions of 1:1 toluene:isopropyl alcohol. The yellow organic phase was separated and washed with 100 mL of water, 100 mL of saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure. The resulting orange oil was treated with three successive 100-mL portions of dichloromethane and each time the dichloromethane was removed under reduced pressure. Further concentration under high vacuum afforded 8.0 g (98% crude yield based upon the starting amide) of the N-allylamidine O as a bright yellow solid which was 88% pure by LC. By multiplying the crude yield times the LC purity a final yield of 86% was obtained. The 1 H NMR and mass spec were consistent with N-allyl, N′-(3-tert-butyl-5-pyrazolyl)-4-nitrobenzamidine (O).
1 H NMR spectrum (CDCl 3 , 300 MHz), δ (ppm): 1.32 (s, 9H), 3.81 (br s, 2H), 5.15-5.31 (m, 2H), 5.77-5.90 (m, 1H), 6.02 (s, 1H), 7.57 (appar. t, J=7.5 Hz, 1H), 7.89 (appar. d, J=9.0 Hz, 1H), 8.26 (dd, J=9.0, 1.5 Hz, 1H), 8.43 (appar.t, J=3.0 Hz, 1H), 9.37 (br s, 1H). LRMS m/z 326 (M − ).
The entire contents of the patents and other publications referred to in this specification are incorporated herein by reference.
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Disclosed is a process comprising reacting an N-allylimino nitrobenzene compound with a diaminodinucleophile to form an α-amino-N-allylamidino nitrobenzene compound and the compound itself.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. Ser. No. 08/445,265, filed May 19, 1995 which will issue on Dec. 16, 1997 as U.S. Pat. No. 5,697,901, which is a continuation-in-part of U.S. Ser. No. 08/076,550, filed Jun. 11, 1993, now abandoned which is a continuation-in-part of U.S. Ser. No. 07/897,357, filed Jun. 11, 1992, for "System and Method for Transplantation of Cells", by Elof Eriksson and Peter M. Vogt, now U.S. Pat. No. 5,423,778, which is a continuation-in-part of U.S. Ser. No. 07/707,248, filed May 22, 1991, by Elof Eriksson, now U.S. Pat. No. 5,152,757, which is a continuation of U.S. Ser. No. 07/451,957 filed Dec. 14, 1989, now abandoned.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to a system for delivering genetic material into cells in situ in a patient.
Various methods for introducing genetic material into an internal or external target site on an animal exist. Most prominent are methods of accelerated particle mediated gene transfer, such as are described in U.S. Pat. No. 4,945,050 (Sanford, et al.), U.S. Pat. No. 5,204,253 (Sanford, et al.) and U.S. Pat. No. 5,015,580 (Christou, et al.).
Other methods have focussed on introducing genetic material into skin cells, particularly keratinocytes. Keratinocytes are the principle cells which cover the surface of the body. They are capable of producing proteins, particularly keratin, which constitute the main surface barriers of the body. For several different reasons, keratinocytes are attractive potential targets for gene transfer. Since they are located on the surface of the body, they are easily accessed both for gene manipulation and monitoring. If complications from gene transfer would occur, for instance, the development of local tumors or local infections, these could more easily be treated in the skin than elsewhere.
To date, genetic manipulation of keratinocytes has been done in one principal way. Skin has been harvested, the keratinocytes have been separated from the fibroblasts, and then the keratinocytes individually isolated and brought into suspension. These suspensions of keratinocytes have then been cultured to confluence using tissue culture techniques, as reported by Rheinwald, J. G., Green, H. Serial Cultivation of Human Epidermal Keratinocytes: The Formation of Keratinizing Colonies From Cells. Cell G, 331-343, 1975.
The new genetic material has been introduced into the keratinocyte while being grown in vitro using either a viral vector or plasmid, as reported by Morgan, J. R., Barrandon, Y., Green, H., Mulligan, R. C. Expression of an Exogenous Growth Hormone Glue by Transplantable Human Epidermal Cells. Science, Vol. 237, 1476-1479 (1987) and Tenmer, J., Lindahl, A., Green, H. Human Growth Hormone in the Blood of Athymic Mice Grafted With Cultures of Hormone-Secreting Human Keratinocytes. FASEB J., 4:3245-3250 (1990). The transfected cells are then usually resuspended and grown on selective media in order to increase the yield of transfection. Sheets of keratinocytes are then transplanted back to the mammal from which the keratinocytes were harvested.
Even though the in vitro yield has been acceptable, the in vivo yield has been unacceptably low, both short and long term. It has been very difficult to document any significant long term (more than thirty days) expression with these techniques, for example, as reported by Garlick, J. A., Katz, A. B., Fenvjes Esitaichman, L. B. Retrovirus Mediated Transduction of Cultured Epidermal Keratinocytes. J. Invest. Dermatol., 97:824-829, 1991.
BRIEF SUMMARY OF THE INVENTION
Direct gene transfer of genetic material into internal or external target sites in optional combination with the use of an "in vivo" culture chamber is particularly effective for long term expression of polypeptides.
Direct delivery of genetic material is accomplished by repetitive microneedle injection into intact skin cells, open skin wounds, and internal tissues or organs. In a 1 cm 2 target area, microneedles make between 500 and 5000 separate injections of an aqueous solution comprising genetic material at a desired concentration.
By employing the optional culture chamber system, direct in vivo gene transfer to exposed cells in an open wound can be performed. If these cells were not covered by the chamber, they would desiccate and die. The chamber also completely seals the wound from the outside, eliminating the spread of genetic material and vectors to places outside of the wound. At the same time, the chamber prevents the accidental introduction of undesired contamination, including viruses and other microorganisms and chemical contaminants into the wound.
The use of the chamber system for gene transfer also allows non-invasive assessment of the success of transfer by assaying for the presence of the expressed protein in wound fluid, in contrast to the prior art use of invasive techniques, such as biopsies, in order to achieve the same assessment of early expression.
A wide variety of proteins and materials can be expressed, either for secretion into the general blood and lymphatic system, or to alter the properties of the protein, for example, to not express proteins eliciting an immune response against the transplanted cell.
It is an object of the present invention to provide a method for delivery of genetic material which is economical, and practical, and can be customized to the patient with minimal effort and expense.
It is another object of the present invention to provide an apparatus suitable for direct delivery of genetic material to internal target sites.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic representation of a microseeding device for delivering genetic material into cells of a patient.
FIG. 2 is a cross-sectional view of a microneedle 10 shown in FIG. 1.
FIGS. 3(a and b) are representations of microseeding devices for delivering genetic material into cells of a patient.
FIG. 4 is a schematic of the exposed undersurface of a partial thickness skin flap used to expose hair follicles to obtain epidermal stem cells.
FIG. 5 shows the EGF concentration in target sites [intact skin (Stippled) and wound (Filled)] at various times after microseeding with an EGF-expressing genetic construct.
FIG. 6 shows the levels of EGF in fluid and in tissue biopsies taken 3 days after delivery of pWRG1630 into intact skin and into partial thickness wounds.
DETAILED DESCRIPTION OF THE INVENTION
The method described herein is a method for delivering genetic material into cells at an internal or external target site on an human or non-human patient using a microneedle delivery apparatus. This process has been termed "microseeding" by the inventors. Examples of disorders that can be treated include wounds such as burns, pain, tumors, and infections.
Also described herein is a microneedle delivery apparatus for delivering DNA according to the method of the present invention.
Also described herein is use of a treatment system for wounds and other skin disorders that can optionally be employed in the method of the present invention when delivering DNA to an external target site. The treatment system has previously been described in U.S. Pat. No. 5,152,757, which is incorporated herein by reference.
Target Cells.
The method of the present invention delivers genetic material into any accessible target cell type in any human or non-human patient. Among non-human patients, most preferred are mammalian animals, especially domesticated animals such as dogs, cats, cattle, swine, goats, sheep and the like, in which the method is envisioned as a desired veterinary therapy.
The preferred target cells in all target animals are skin cells, which are most readily transduced with genetic material because of their proximity to the exterior of the patient. "Skin" is intended to encompass cells in all skin layers including epidermal, dermal, and subdermal layers. More specifically, skin includes superficial keratinocytes, stem cell keratinocytes and dermal fibroblasts. For purposes of this patent application, "skin" also encompasses the muscular tissue beneath the skin that can be accessed from the exterior by the microneedles described herein. The target skin can be intact or can be prepared for treatment by wounding. In addition, internal tissues and organs within a patient are also desirable target sites into which exogenous genetic material can be introduced in keeping with the method. Suitable internal sites include any soft tissue that can be pierced by microneedles as described herein. For purposes of this patent application, "internal sites" are those target sites which are not accessible from the exterior of the patient but which are accessible using the microneedle delivery device for internal use, as disclosed herein. Without intending to limit application of the method to particular internal sites, specifically envisioned as targets are smooth and striated muscle, connective and epithelial tissues, walls of abdominal passages, and internal organs including, but not limited to, liver, kidney, stomach, appendix, intestines, pancreas, lungs, heart, bladder, gall bladder, brain and other nervous system cells, as well as reproductive, endocrine, lymphatic and other glandular tissues. The region surrounding the bone, in particular the periosteum, is also well suited as a target tissue for in vivo gene transfer by microseeding in human and non-human animals.
In any particular target tissue, it is envisioned that a subpopulation of cells (e.g., keratinocytes in skin cells) may be most preferred target cells, insofar as they exhibit a superior ability to take up or express introduced genetic material. The particular preferred subpopulations can readily be determined empirically in an experimental system designed to measure a particular response to introduction of a particular genetic molecule. If a particular subpopulation of cells is found to be a preferred target, one of ordinary skill will understand how to direct the genetic material into that subpopulation either by orienting the microneedle delivery apparatus toward a portion of a target tissue, or by selecting a preferred delivery depth to which the genetic material is delivered, or both.
Genetic Material.
The genetic material that is introduced into the target cells using the method can be any native or non-native genetic molecule that can provide a desirable activity to a target cells. The genetic material can encode any native or non-native protein or polypeptide having such a desirable activity in a target cell. Alternatively, the introduction of the genetic material itself can alter the target in a desirable way, such as by interference with the transcription or translation of a gene normally present in the target. "Non-native" means that neither the genetic material, nor any protein or polypeptide product encoded by the genetic material is detectable in the untreated target cells or tissue. The nature of the introduced genetic material itself forms no part of the present invention.
The genetic material, can be RNA, but is preferably DNA and is most preferably supercoiled plasmid DNA. The genetic material is prepared according to any standard preparation or purification method among the many known to the art and is provided in an aqueous solution, buffered or unbuffered. The amount of genetic material delivered is not absolutely critical, though better results have been observed for DNA molecules tested when the amount of DNA is below 500 μg, and preferably below 200 μg. Suitable concentrations can readily be determined by routine experimentation. Delivery to the target site of approximately 100 μl of an aqueous solution containing genetic material in the preferred concentration range is sufficient to function in the method. The genetic material can be attached to microparticles such as iron oxide particles in the range of 0.5 to 1 micron in size. Alternatively, unsupported genetic material in solution is also suitable for delivery according to the method.
The genetic material typically includes an expressible DNA sequence that encodes a native or non-native polypeptide. The DNA can be of any length and can include genomic DNA fragments, engineered DNA produced in a microbial host, or synthetic DNA produced according to known chemical synthetic methods, including, but not limited to, the Polymerase Chain Reaction. The art is cognizant of the various required and preferred elements (including promoters, terminators, transcription- and translation-regulating sequences, and the like) that one of ordinary skill would provide on an expressible genetic construct. One of ordinary skill is also able to select appropriate elements from the many known elements to facilitate or optimize expression in a particular target animal. The native or non-native polypeptide produced in the method can be maintained intracellularly or secreted to the extracellular space. One of ordinary skill in the art is familiar with the genetic elements necessary to direct a sequence to a particular cellular or extracellular microenvironment and with methods for constructing a genetic construct to facilitate such direction. For example, a polypeptide expressed after gene transfer can be directed to cross a cell membrane by adding an appropriate signal peptide to the gene that encodes the polypeptide.
Desirable proteins that can be expressed after gene transfer include, without limitation, growth factors, hormones, and other therapeutic proteins. These would speed the healing of wounds and correct certain deficiencies, such as parathyroid, growth hormone, and other hormone deficiencies, as well as deficiencies of certain clotting factors such as factor VIII. For instance, if the gene encoding the growth factor is introduced into the genome or cytoplasm of target skin cells in a wound, these cells can be made to produce a desirable growth factor. The expressed growth factor will then not only speed the healing of the wound, but may also help to heal wounds that would not heal otherwise.
Cells can also be engineered to not express a protein, such as a protein involved in an immune response, for example, a human leukocyte antigen (HLA). This can be accomplished in a variety of understood ways, the most common being the introduction of "antisense" genetic material that hybridizes with mRNA present in a cell to prevent translation of the mRNA.
This approach can be used to insert other genetic material of interest into target cells in order to eliminate, or restore, missing or defective functions of patients having any of a variety of skin diseases. Also, the mode in which cytokines act can be changed in that when a factor is expressed in a cell that normally does not produce that factor, a paracrine pathway can be changed into an autocrine pathway. In the same fashion, target cells can be genetically engineered to repair or compensate for inherent genetic defects, such as epidermolysis bullosa. The target cells in a superficial excisional wound can be microseeded with appropriate genetic material to generate a new epidermis with the desired features. Problematic wounds may require coverage of the defect and fast healing.
Microneedles
Genetic material can be delivered directly into target cells of a patient using a microneedle delivery apparatus to repeatedly puncture a target area, and to deliver, with each puncture, a small amount of the genetic material provided in an aqueous solution. A microneedle delivery device 10, suitable for use in the method of the present invention, such as the preferred devices shown in FIGS. 1-3(a and b), include microneedles 12 having beveled tips 14, mounted in a row on a support 16, such as a handle. The microneedle diameter is about 300 microns. The beveled tip 14 tapers to a zero diameter along the 2 mm closest to the tip; at 100 microns from the tip, the diameter is about 60 microns, while at 50 microns from the tip, the diameter is about 35 microns. The beveled tip 14 facilitates puncturing of the selected target site by the microneedles 12 and opening of cells along the needle path, which is thought to facilitate high expression levels after delivery. The microneedles 12 can be solid (FIG. 3) or can have hollow centers (as in FIG. 2), although preferred microneedles are solid, since no genetic material is lost to the interior of the needle during delivery. If hollow needles are used, the hollow center should terminate to the side, rather than the bottom, of the tip 14, as is shown in FIG. 2. Moreover, the solid interior applies significantly higher force than hollow needles to the solution containing the genetic material, to help direct the material into the target cells.
The microneedles 12 are reciprocally driven by a power source 18, secured to the support, which can be an electric motor or any other suitable power source. The microneedles 12 have a proximal end and a distal end, relative to the power source 18. If the motor is electric, as in the preferred devices, the motor is attached to a switch that controls whether electric power is applied to the motor. The switch can provide variable or constant power to the device. The motor is connected by a cam to a reciprocating piston 20, which includes an attachment slot thereupon. The microneedles are joined to the piston attachment slot through a bar connected to the microneedles and inserted into the piston attachment slot. When energized, the piston can oscillate the microneedles at a wide range of speeds between 8 and 50 oscillations per second. The speed of the needles is not thought to be critical to their use in the invention. The amplitude of the oscillating microneedles can vary up to approximately 5 mm. The amplitude is also not believed to be critical, the effect of a greater amplitude simply being a deeper penetration depth. A 3 mm amplitude is suitable. Both the speed and amplitude can be predetermined by, for example, varying the power applied to the motor.
Surrounding the microneedles is a needle tube 22, shaped to accommodate the microneedles 12, which supports the microneedles 12 in all four directions and urges the microneedles 12 into a very small delivery area. The needle tube 22 itself is rigid or semi-rigid and is secured to the support 16 with a fastener, such as a wing nut, in a narrow opening.
If hollow microneedles 12 are used, as in FIG. 2 (schematic), the hollow centers of the microneedles are in fluid communication with controllable port 24 for connecting a fluid receptacle that holds the solution comprising the genetic material. The fluid receptacle can be a syringe. The solution can flow from the fluid receptacle through the hollow centers to the distal tips 14 of the microneedles 12.
If solid microneedles are used, delivery of the solution comprising genetic material through the microneedles to the tips is not practical. No fluid delivery structure is needed if the device is to be used for delivery only to an external target site, such as an intact skin or wound target site because fluid delivery can be readily accomplished by manual delivery of the solution to the site before applying the microneedle device. However, tubing for delivering the genetic material, as described elsewhere herein, is preferably also used for delivery to an external target site because less DNA is consumed when delivery is performed through delivery tubing.
When the genetic material is to be injected into internal sites within the patient, the genetic material needs to be delivered to the distal tips 14 of the microneedles 12. In a preferred apparatus 25 that facilitates direct gene transfer to an internal or external target site, separate structures are provided as part of the device, to bring the genetic material in solution to the distal tips of the solid microneedles. As shown in both embodiments of FIGS. 3a and 3b, the tube that surrounds the needle can be provided with one or more additional channels 26 on its inner or outer surface to serve as fluid conduits. The channels 26 can be separate from and attached to the needle tube, or can be formed directly thereto or therein. A first channel terminates at a first end at the motor end of the device at a controllable port 28 connectable to a fluid receptacle such as a syringe. A second end of the channel is at the distal end of the microneedles 12. A second, optional, larger channel, connectable by a controllable port 30 at one end to an external suction device, also opens at the opposite end near the tips, and provides suction of fluid from the delivery site. The second channel can alternatively be provided with a second fluid receptacle and used as a second fluid delivery channel to deliver a second fluid, such as a sealant, a biological glue or a hemostatic agent, to the distal ends of the solid microneedle tips.
The overall size of the apparatus 25, and, in particular the length of the microneedle 12, is such that that power source remains user-operable and external to the patient when the distal end of the microneedle 12 is positioned at the internal target site. Thus, the length will depend upon the distance of the internal site from the incision through which the apparatus 25 is introduced into the patient. A suitable length of the device for internal use is 10-15 inches, preferably 13 inches, which allows adequate manipulation to numerous internal target sites.
The inventors have determined that optionally placing the microneedles 12 in a 35% (12.1 M) solution of hydrochloric acid for 12 hours before use in the method etches the needles slightly. Another way to modify the needles is to bombard the needles with aluminum oxide microbeads. It is not yet known whether needle surface modification provides additional surface area onto which the genetic material can adhere during delivery, or whether the modified needle surface advantageously affects the needle's ability to puncture the cells. Although not essential, dipping the microneedle tips 14 into hot paraffin can also prevent DNA from sticking irreversibly to the microneedles during microseeding.
Direct in situ introduction of the genetic material into target cells.
Microseeding can be used to insert genetic material directly into target cells in situ in a human or non-human patient. One or more microneedles are ideal for this purpose. In the method, a solution containing genetic material is placed on the target surface. The microneedles are then moved as a group across the target site to "inject" and thereby deliver the genetic material through the surface of the target to the underlying tissue along several parallel lines. The microneedle or microneedles repeatedly penetrate a site on a surface of the target tissue to a depth within the tissue at which a plurality of preferred or most preferred target cells are found. The penetrating and delivering steps are repeated in the vicinity of the target cells until sufficient genetic material has been delivered that a change in the patient attributable to the delivery of the genetic material is detectable, preferably within twenty-four hours. The change can be physiological, biochemical, histological, genetic, or immunological, or otherwise. Detection of an added or eliminated characteristic of the patient, genetic or phenotypic, is sufficient.
The method can be used to deliver unsupported genetic material in solution, or genetic material attached to carriers, such as iron oxide microparticles. This technique is useful for delivery of a suspension of genetic material alone, without delivery of infectious viral material or attachment to microparticles. This is desirable because of the minimal sample preparation time required. In addition to persistent expression, high transient expression levels are observed.
It is preferred that a large number of independent microneedle penetrations be performed to ensure delivery of an adequate amount of genetic material in the method. The number of penetrations should range from between about 500 to about 5,000 per cm 2 of surface at the target site. Preferably, between 3,000 and 4,000 independent penetrations should be performed at each 1 cm 2 site. To reduce the total delivery time, it is highly preferred that more than one oscillating microneedle, preferably six or more oscillating microneedles, be used to deliver the genetic material. Because of the large number of microinjections, it is also highly preferred that the oscillation be accomplished using an apparatus designed for repeated penetration of oscillating microneedles, such as either of the microneedle delivery devices described herein. Such a microneedle delivery device, placed under control of a scanner 27, can systematically and accurately cover a predefined area of skin or other tissue, and can deposit the genetic material very evenly into a large number of target cells in the predefined area.
For delivery into a wound or intact skin, the microneedles are placed over a desired treatment site that has previously been prepared, as needed. No particular preparation is necessary for delivery into intact skin. The site for delivery of genetic material into a wound is prepared by removing infected or burned skin, if necessary, or by creating an appropriate wound for the purpose of in situ delivery of genetic material. An artificially created wound is shown in FIG. 4. Stem cells located in the hair follicles 30 deep to the epidermal dermal junction can be exposed by creating a flap 32 of epidermis where the deep portion of the flap contains the basal layer of the epidermis. The exposed wound surface 34 contains the portion of the hair follicles with the stem cell keratinocytes. After delivery of the genetic material, the epidermal flap 32 of an intentional wound is sutured back in place and the wound is sealed with a dressing or in a chamber, as described below.
When internal delivery is desired, surgical access to a desired delivery site is provided for a microseeding apparatus such as that described herein. Surgical access to the interior of the patient can be provided through laparoscopic ports made in a manner known to the art. The laparoscopic ports can also accommodate a viewing scope and an assisting instrument for accurate placement of the microseeding apparatus. In such cases, no wound chamber is needed after treatment, since the treated cells are not exposed to the air and will not dry out.
Regardless of location of the delivery site, the beveled tips of a plurality of microneedles are surrounded with an aqueous solution comprising the genetic material. As noted above, the genetic material is provided to the microneedle tips manually or via a channel provided on the microneedle delivery device. Oscillation of the microneedles placed on the target site at a rate of between 8 and 50 oscillations per second is initiated by energizing the power source. The power source reciprocates the piston at a predetermined rate so that the microneedles repeatedly enter the treatment site to a desired depth. The desired depth, which can range from 0 to about 5 mm, is selected to deliver the solution containing genetic material to a depth at which a large number of cells competent to take up and express the genetic material are found. For instance, it has been determined by the inventors that, when the target is skin, the preferred target cells are keratinocytes, generally located at about 2 mm beneath the skin surface. The optimal penetration depth for other delivery sites can readily be determined empirically by looking under controlled experimental conditions for a desired change in an art-accepted model system, for example, a pig, using a physiological, biochemical, chemical, histological, genetic, immunological or like detection method.
After treatment, no particular method steps need to be followed. However, should one desire to either regulate the fluid in which the treatment site is bathed, or to analyze the products produced at the treatment site, isolation of the site in a vinyl adhesive chamber, or other such isolating chamber is recommended.
The technique can also be enhanced by practicing it in combination with other biological agents, such as liposomes.
This method of introducing genetic material into cells may be superior to gene transduction using plasmids or retroviral vectors, because the latter have an unacceptably low yield. Transfer of genetic material with accelerated particles, employing "gene guns," have a higher yield than plasmid or retroviral transduction, but can, in some embodiments, have other disadvantages, such as a very loud blast and a risk of accidental discharge. Moreover, this method does not leave particles inside patients after treatment. For internal delivery, the microneedles are advantageous because it is not necessary to fully expose internal organs before delivery; rather, only an few incisions large enough to receive a manipulable microneedle apparatus, assisting tool, and viewing scope are made.
Thus, microseeding of genetic material into cells with oscillating microneedles provides a practical, affordable, and a predictable method of insertion of genetic material for localized or systemic expression. The invention finds particular utility as a method for immunization against a non-native polypeptide, and as a method for introducing a foreign genetic material as a therapeutic agent.
The Chamber.
If a polypeptide is secreted from treated intact skin or wound cells, it may be desirable to localize the secreted polypeptide at or near the target site. Such is the case, for example, when the secreted polypeptide accelerates wound healing. In such cases, the target site can be isolated after treatment by enclosing the treated wound site in a sealed chamber, in the manner of U.S. Pat. No. 5,152,757, which is incorporated herein by reference. The structure of the chamber is described in the referenced patent, and is not described in detail herein.
Isolation of the treatment site has an additional benefit of protecting the treatment site from external pathogens such as bacteria and viruses. Moreover, one has the ability to surround the treated target site with fluid having a desired composition, and the ability to analyze samples of the fluid to evaluate the concentrations of desired or undesired compounds in the fluid. However, if delivery is made into a non-wound skin site, use of the sealed chamber may not be necessary, as the skin provides sufficient protection to transduced cells.
In a preferred embodiment, treated skin and wound cells are protected by a system including a chamber, treatment fluid (which may be nutrient media, physiological saline, or some other compatible solution), treatment additives (such as antibiotics and buffering agents), means for controlling treatment variables and means for monitoring cell growth.
The treatment system includes a chamber securable about the periphery of a wound, having portal means for introduction into and removal of treatment fluids from the chamber, treatment fluid, at least one treatment additive, control means for treatment variables, and monitoring means for monitoring wound conditions. The chamber is secured about the periphery of a wound, a treatment fluid and at least one treatment additive are introduced into the chamber, and the treatment variables are controlled according to wound conditions. The wound chamber, which is made of vinyl or other flexible transparent material, such as polyurethane, has a bellows shape and an opening which corresponds to the size of the wound, either the chronic wound or a superficial wound created specifically for the purpose of gene transfer. The chamber contains a small amount of normal saline with antimicrobial agents. When the microneedle is used, the DNA is delivered into the cell and the chamber with normal saline and antibiotics is then attached to the perimeter of the wound. Wound fluid is sampled in order to assay expression of the secretable gene product (e.g., growth factor) at 24 and 48 hours. The wound is treated in the chamber until healed.
The chamber encloses a predetermined surface area about the treatment site. The chamber provides protection for the wound from the surrounding non-sterile environment, control of treatment variables, containment for continuous fluid treatment, an effective delivery system for additives, direct monitoring of cell growth. Monitoring can be accomplished visually if the chamber is formed of a transparent material, or by extraction and analysis of fluid from the chamber. Fluid extracted from the system can be analyzed for factors which provide an indication of the status of healing, as well as the presence of undesirable components such as microorganisms, low oxygen, high carbon dioxide and adverse pH. The fluid may be tested for the number and type of bacteria and other microorganisms, the number and type of cells, the amount and type of proteins secreted by the patient and the cells within the chamber, and other factors such as drug levels, oxygen, carbon dioxide and pH.
The treatment system provides control over variables including temperature, specific ion concentration, colloid osmotic pressure, glucose concentration, amino acid content, fat concentration, oxygen concentration and carbon dioxide concentration and pH.
Portal means provide access for the introduction of treatment fluids and treatment additives into the chamber and extraction of fluid from the chamber. In some embodiments, treatment fluid is introduced into the chamber by injection with a conventional hypodermic syringe through the wall of the chamber, preferably made of a flexible, self-repairing plastic. In other embodiments, the chamber has an inlet and outlet port or separate inlet and outlet ports. Valve mechanisms are necessary where the apparatus is not to be connected to a treatment fluid reservoir and a drain or connected to a continuous perfusion system. The seals of the ports would be broken at an appropriate time for connection to other apparatus, such as a continuous perfusion system, at a hospital for example.
A preferred embodiment of the treatment system incorporates continuous perfusion of treatment fluid through inlet and outlet ports. A pump or gravity may be used to move the treatment fluid. The treatment fluid may be recirculated after filtering and other appropriate action (eg. heating or cooling). Alternately, fresh treatment fluid may be introduced and contaminated fluid disposed of. In an embodiment described in U.S. Pat. No. 5,152,757, the chamber contains a reservoir or more than one chamber, with the additional chamber serving as a source of fresh culture media, oxygen, and treatment additives.
As those skilled in the art will readily recognize, a removable sheet for protecting the adhesive and maintaining the sterility of the interior of the chamber is desirable. The chambers may be stored in a sterile pack for years. This chamber can take many shapes in order to fit wounds from the size of one square centimeter up to the size of a whole extremity. It is important that the adhesive surface be sufficient to secure the bandage to the skin surface to ensure a leak-proof seal.
As previously mentioned, treatment fluid and treatment additive introduction and subsequent extraction may be accomplished directly through the chamber walls by a needle and syringe. A self-repairing material to construct chamber 10 is contemplated. An alternative method would be to use inlet and outlet ports allowing the introduction and extraction of various substances into the chamber.
If the chamber is to be used to cover a wound or intact skin site, the skin adjacent to the site is cleaned so that there will be good adhesion between the chamber and the skin. The open portion of the chamber is then placed over the site, with the adhesive edges securing the chamber to the skin, then an appropriate culture medium and cells are introduced into the sealed chamber. The treatment fluid may be introduced and then extracted in favor of fresh culture media in a continuous or batch process. Selected treatment additives may be introduced into the chamber continuously or at a predetermined time or at periodic intervals. Appropriate control of treatment variables is also effected. Monitoring is accomplished by examination of the patient and visual examination of the fluid within the chamber and the wound itself. In addition, samples of fluid are extracted from the chamber for analysis and diagnosis. The chamber is removed once sufficient healing of the wound has occurred.
For example, to determine whether or not the wound is healed, the protein content of the extracted fluid is analyzed. When the protein content of the extracted fluid decreases to the level present in chambers containing fluid that are placed over normal skin, the wound is healed. Methods for determining protein content are well known in the art and are inexpensive and fast. The types of protein and the relative amounts of the types of protein can also be determined to further evaluate healing and expression of exogenous genetic material.
Control of Treatment or Culture variables using wound chamber.
Treatment of each patient is specific for the conditions within the chamber. Control over treatment variables can include continuous cooling to 34° C. for the first 24 hours. Monitoring can include analyzing extracted fluid for protein and microorganisms, with samples extracted every 24 hours. For example, when the number of microorganisms is less than 10 4 per milliliter or per cc, infection has been resolved. Protein levels checked every day should be less than 24 mg/dl/cm 2 .
As noted above, there are a number of treatment variables which may be controlled by the system. One such treatment variable which may be controlled is temperature. It has been found that heating the wound from a temperature of approximately 27° C. (a common temperature of a lower extremity wound) to 37° C. accelerates wound healing. Experimental data has shown that at a wound temperature of approximately 37° C., the rate of wound healing is more than twice as fast as at a temperature of 27° C. The temperature of the wound area can be achieved by heating the treatment fluid. Cooling has also been proven beneficial in the case of acute burn and other traumatic wounds. Cooling reduces pain, swelling and destruction of tissue. In general terms, acute wounds benefit from cooling during the first hours after occurrence of the wound and later, wounds benefit from a temperature of approximately 37° C. Cooling can similarly be effected by cooling the treatment fluid.
Other treatment variables may also be optimized. For example, ion concentrations should be kept close to extracellular ion levels. Glucose, amino acid and fat concentrations should be kept close to the concentrations present in plasma or corresponding to a skin tissue culture medium. Oxygen and carbon dioxide concentrations should also be maintained at their normal tissue levels. Oxygen is an important treatment additive, and is essential for cell growth.
Treatment additives and Culture Media in wound chamber.
Normal or physiological buffered saline is the basic culture media. Buffering agents, anesthetics such as lidocaine, antibiotics such as penicillin or streptomycin, chemotherapeutic agents, and growth factors including epidermal growth factor (EGF), platelet-derived growth factor (PDGF), insulin-like growth factor (IGF), basic fibroblast growth factor (bFGF), and cholera toxin (CT) can be added to the culture/treatment media. Tissue culture mediums and fluids which increase osmotic pressure and oxygen accessibility may also be introduced to the chamber as treatment additives.
Selection of treatment additives is wound specific. For example, if an infection has been diagnosed, antibiotics are added in the amount of one single parenteral dose per 1,000 cc of fluid. Furthermore, a treatment additive of gentamicin, tobramycin or carbenicillin is appropriate for a wound infection with Pseudomonas, detected by analyzing extracted fluid. When hypoxia has been diagnosed, the liquid is passed through an oxygenating chamber before entering the chamber. If a tumor has been diagnosed, chemotherapy is given in an amount of one single parenteral dose per 1,000 cc of fluid. In situations involving a wound containing necrotic tissue and debris, proteolytic enzyme is added to the liquid. Immune modulators are added to the treatment fluid if an inflammatory reaction is exhibited. Epidermal growth factor is added in a concentration of 10 nanograms per cc when required.
The present invention will be further understood by reference to the following nonlimiting examples.
EXAMPLES
Example 1
Introduction of DNA into keratinocytes and fibroblasts using "microseeding"
Iron oxide particles ranging in size from 0.05 microns to 1 micron in diameter were mixed with DNA plasmids in Tris-EDTA buffer. Drops of this material were placed on intact human skin. A microseeding was placed on the material on the skin to insert, or inject, the DNA into superficial keratinocytes as well as stem cell keratinocytes in the deep epidermis, or dermal fibroblasts.
Example 2
Microseeding of Expression Plasmids Into Skin and Wounds, Without Carrier Particles
The method of the present invention was tested in a laboratory model system for wound healing. Dorsal skin sites on domestic female Yorkshire pigs (3-4 months old, 40-45 kg) were outlined and were randomly assigned for partial-thickness wound or intact skin treatment. Wounds (15×15×1.2 mm) were created using a dermatome. Animals were maintained in accordance with the Harvard Medical Area Standing Committee on Animals. Surgical procedures were performed under Halothane (1-1.5%) anesthesia in a 3:5 mixture of oxygen and nitrous oxide.
Supercoiled plasmid DNA was introduced into the intact skin or into the wound bed using an oscillating microneedle apparatus driven by an electric motor and a piston. The oscillating microneedle apparatus for external (skin and wound) use is commercially available from Spaulding and Rogers Manufacturing, Inc. (Voorheesville, N.Y.). Controls included skin and wound sites untreated with DNA. 100 μl of solution containing supercoiled plasmid DNA in water was introduced into the intact skin or into the wound bed. After delivery, the skin and wound site were covered with sealed vinyl adhesive chambers, of the type described in U.S. Pat. No. 5,152,757, containing 1.2 ml of isotonic saline with 100 units/ml penicillin and 100 mg/ml streptomycin.
a. Histochemical Determination of Transduced Cells
Plasmid pCMVβ-gal, described by MacGregor, G. R. and C. T. Caskey, Nucl. Acids Res., 17:2365 (1989), was delivered to wound sites. Plasmid pCMVβ-gal encodes a β-galactosidase enzyme which is histochemically detectable upon the addition of 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-gal chromogen), which forms a blue precipitate in transduced cells. The treated tissues and control tissues were frozen and thin sections prepared from the frozen samples were histochemically stained for β-galactosidase activity. Positive staining was observed only in the epidermal keratinocytes and in the hair follicles of sites treated with pCMVβ-gal DNA. No stained cells were observed in control sections.
Skin biopsies were flash-frozen, embedded in O.C.T. and cut into 8 micron cross-sections. The sections were then fixed in 1.5% glutaraldehyde and were stained for β-galactosidase activity. See MacGregor, G. R. et al., Somat. Cell Molec. Genet. 13:253 (1987). The tissues were counterstained with hematoxylin. Blue spots were observed in portions of the tissues having β-galactosidase activity.
b. Delivery of Epidermal Growth Factor-Encoding Plasmid DNA
Plasmid pWRG1630, an epidermal growth factor-encoding expression plasmid, contains an in-frame fusion of the hGH secretory signal peptide to the mature EGF polypeptide. Plasmid pWRG1630 includes, upstream of the chimeric hGH-EGF gene, the cytomegalovirus (CMV) immediate early transcriptional promoter. Downstream of the mature human EGF coding region is the 3' untranslated sequence and polyadenylation signal from the bovine growth hormone gene (obtained from pRc/CMV, commercially available from Invitrogen, Inc.).
The complete nucleotide sequence of plasmid pWRG1630 is attached hereto as SEQ ID NO: 1. The 93 amino acid long polypeptide, encoded in two separate exons by pWRG1630, is shown in SEQ ID NO: 2. Referring now to SEQ ID NO: 2, the hGH secretory signal peptide is the first 26 amino acids. These amino acids are cleaved during signal-peptide processing at a cleavage site between amino acids 26 and 27. The next 14 amino acids are encoded in part by the hGH DNA and in part by the plasmid polylinker. Following the 14 amino acid long portion, is a 53 amino acid long mature EGF portion that corresponds to the 53 amino acids of the naturally occurring mature EGF peptide. The ability of this plasmid to produce an EGF polypeptide has been demonstrated by showing that after transduction of the plasmid into cultured fibroblast KB-3-1 cells, a polypeptide secreted into the culture medium reacted with hEGF monoclonal antibodies in ELISA and Western Blot assays. The culture medium containing the secreted polypeptide was biologically active in an [ 3 H]-thymidine incorporation assay using primary human foreskin fibroblasts and Madine-Darvy Canine Kidney (MDCK) cells.
c. Expression After Delivery
Initial experiments were performed to determine DNA transfer conditions to obtain high specific transfer (expression level per μg of input DNA). Parameters tested included the amount of DNA delivered per wound, the depth of needle penetration, and the density of penetrations. These parameters were adjusted to yield the greatest concentration of hEGF polypeptide in wound fluid after treatment. The preferred conditions for this plasmid were determined to be 20-200 μg of pWRG1630 DNA per wound delivered to a penetration depth of 2 mm at a density of 3,330 penetrations per cm 2 surface area. In the experiment, 7500 penetrations were performed using the oscillating microneedle apparatus in a 2.25 cm 2 surface area over a 25 second duration. Microneedles used for microseeding DNA were routinely pre-treated by dipping the tips of the microneedles into hot paraffin and then placing the microneedles into a 35% (12.5 M) solution of hydrochloric acid for 12 hours. This pre-treatment scarifies the needles and provides increased surface area for trapping DNA during delivery.
Plasmid pWRG1630 was delivered into wounds at 20 μg, 200 μg or 2,000 μg per wound. At 72 hours post delivery, the wound tissue and the chamber fluid bathing the wound were tested for EGF polypeptide. EGF gene expression was monitored daily after gene transfer by measuring EGF concentrations in wound tissue, intact skin, and wound fluid for at least 7 sites for each group. Wound fluid was withdrawn from the wound chambers every 24 hours. The fluid was immediately chilled on ice, filtered and centrifuged. Samples from each group were then pooled, flash frozen and stored at -70° C. Skin biopsies were homogenized and protein was extracted from the homogenate before analysis. A commercially available EGF ELISA assay (Quantikine, R & D Systems, Minneapolis, Minn.) was used to determine EGF concentrations in samples. The minimum detection limit was 0.2 pg EGF per ml.
When 20 μg of DNA were delivered, between about 25 and 75 (average about 50) pg/ml of EGF were observed.
When 10-fold more EGF-encoding DNA (200 μg) was delivered, both the chamber fluid and the skin extracts contained about 150-175 pg/ml on average. The range of concentrations in the chamber fluid samples was between about 75-250 pg/ml, while the range in the skin extract samples was between about 50-300 pg/ml and was, on average, slightly higher than in the chamber fluid samples.
When yet another 10 fold increase in EGF-encoding DNA (2000 μg) was delivered into wounds, only about a 2 fold increase in EGF concentration was observed over the previous level. In this case, the EGF concentration in the chamber fluid samples ranged from about 250 to about 400 with an average of about 325 pg/ml while the concentration in skin extract samples was, on average, about 400 pg/ml with a range of between about 250 and 575 pg/ml.
From these data, it was determined that a maximally efficient response was observed in the range of 20-200 μg of DNA per wound. In future examples, 20 μg of DNA were delivered per wound or skin site, unless otherwise indicated.
Temporal variation in EGF level after gene delivery was monitored in chamber fluid over 5 days. Maximal EGF concentrations in fluid from wound sites (276±149 pg/ml) were observed 48 hours after microseeding. In fluid from intact skin treatment sites, a maximal EGF level of 165±113 pg/ml was observed 72 hours after microseeding. Detectable EGF concentrations were maintained over the entire 5 day monitoring period, as is shown in FIG. 5. The figure shows the EGF concentration in intact skin sites (Stippled) and in wound sites (Filled). Controls from wound sites seeded with 20 μg of pCMVβ-gal, and wound sites treated topically with 20 μg of EGF DNA are not shown. However, no EGF was detected in these controls using the ELISA assay. No evidence of abnormal cell growth, dysplasia tissue disorganization or the like has been observed in cells microseeded with pWRG1630.
d. EGF Yield in Fluid and Tissue after Delivery
Three days after delivery of the pWRG1630 EGF-encoding plasmid DNA into partial thickness wounds and into intact skin, analysis of the fluid surrounding the delivery site and of biopsies of the tissue itself were performed to determine the yield of EGF in such tissues. The results shown in FIG. 6 demonstrate that EGF levels in biopsied tissue (filled bars) are much higher than EGF levels in the fluid (stippled bars), and can reach nanogram levels. In FIG. 6, EGF in both wound and intact skin was above 2000 pg (2 ng), on average, and in some samples was above 4000 pg (4 ng), three days after treatment.
e. Persistence of Transferred DNA
Wound biopsy specimens were evaluated using the polymerase chain reaction (PCR) on days 1 through 30 to analyze the persistence of the transgenes. DNA was prepared from wound biopsies on days 6, 9, 12, 15, and 30 after delivery using a Puregene kit, commercially available from Gentra. To monitor for the presence of the introduced DNA, 400 ng of DNA prepared from the wound biopsy was mixed in a PCR reaction with 0.2 μg of each primer and 2.5 units of AmpliTAQ® DNA polymerase (from Perkin Elmer) in 100 μl of 10 mM Tris-HCl, pH 9.0 (25° C.), 50 mM KCl, 0.1% Triton X-100, 1.5 mM MgCl 2 , and 0.2 mM of each DNTP. The sequences of the primers used are attached hereto as SEQ ID NO: 3 and SEQ ID NO: 4. After 3 minutes at 96° C., the reactions were subjected to 30 cycles of 60° C. for 75 seconds, 720C for 60 seconds, 96° C. for 60 seconds. See Mullis, K. B. and F. A. Faloona, Meth. Enzymol. 155:335 (1987). A 10 μl aliquot of each reaction mix was analyzed by agarose gel electrophoresis. The PCR products were visualized by staining with an ethidium bromide and their identities were confirmed by Southern Blot (Southern, E. M., J. Mol. Biol. 98:503 (1975) using internal hybridization probes. The PCR results demonstrated that plasmid DNA persisted in the wound site for at least 30 days. It is as yet unclear whether the persistent DNA resides within cells or is present in the extracellular matrix. These results contrast with the observation that both EGF and β-galactosidase protein expression diminish after 5-6 days.
Example 3
Endoscopic DNA Delivery
An anesthetized Yorkshire pig was placed on its back. Laparoscopic ports were placed into the abdomen to accommodate a viewing scope, an assisting instrument, and a microseeding instrument adapted for use inside the patient as is shown in FIG. 3. A DNA solution containing the pCMVβ-gal plasmid and a small amount of a black iron oxide pigment was delivered to four sites in the liver, two sites in the stomach, and two sites in the abdominal wall. The black iron oxide pigment was added to the DNA solution to facilitate visualization of the treated area after the experiment. The DNA in solution was not coated onto the iron oxide.
Three days later, the tissues were harvested from the pig for processing to visualize expression of the inserted lac-Z gene. Strong expression was observed in the stomach. No expression was found in the liver. Expression in the abdominal wall was questionable. A reference site on the skin that was microseeded as a control showed strong expression. It is possible that the rapid healing of the liver tissue may have obscured the target sites and that the sites were missed during harvesting. In any event, the utility of the microseeding instrument for internal use was demonstrated by the strong lac-Z expression levels in the stomach.
Example 4
In vivo gene transfer to the porcine and murine periosteum by microseeding pigs were anesthetized using 1.0-2.5 Halothane delivered in conjunction with a 30:50 mixture of oxygen and nitrous oxide via a facial mask. The heart rate and oxygen saturation of blood was monitored throughout the procedure. Rats were anesthetized using 3 mg of sodium pentobarbital per 100 g of body weight. Animal housing, feeding, and all performed animal procedures were reviewed and approved by the Harvard Medical Area Standing Committee on Animals.
Under sterile conditions the porcine femoral periosteum was exposed, elevated, and the target sites were marked with sutures. The target sites were microseeded with plasmid DNA at 35 μg of DNA per site, as described. Four sites were tested per animal. Likewise, the murine tibial periosteum was prepared and microseeded at 3 μg of DNA per site. The microseeded plasmid DNA was pWRG1630 that encodes a secretable, mature form of human epidermal growth factor. Control sites received sham microseeding treatments without plasmid.
Forty-eight hours after microseeding, the microseeded sites were harvested and were processed as described. Briefly, the biopsies were homogenized and protein was extracted from the homogenate before analysis. The protein was subjected to a commercially available EGF ELISA assay (Quantikine, R & D Systems, Minneapolis, Minn.) which was used to determine EGF concentrations in the samples. The minimum detection limit was 0.2 pg EGF per ml.
The levels of hEGF gene expression are shown below in Tables 1 and 2. No EGF expression was detected in the sham-microseeded controls.
TABLE 1______________________________________PERIOSTEUM, Pigs (35 μg DNA/site), 48 h:periosteal site # 1 2 3 4______________________________________pg/ml of tissue extract 3976 1374 1225 1729.6______________________________________
TABLE 2______________________________________PERIOSTEUM, Rats (35 μg DNA/site), 48 h:periosteal site # 1 2 3 4______________________________________pg/ml of tissue extract 93.3 146.4 57.5 128.6______________________________________
Collectively, these results demonstrate that the periosteal cells can be successfully made to express an exogenous gene by microseeding in an animal. Comparable results are anticipated in humans. The method described in Example 4 can bring about new gene transfer applications in bone healing. For example, by delivering the genes that encode one or more bone morphogenic proteins to the periosteum in an area near a bone defect, the cells that receive the gene by microseeding can express bone morphogenetic proteins which can enhance the healing of the bone defect. A preferred gene for delivery can include, but is not limited to, a gene that encodes a product that can modulate bone growth, which products can include, for example, cytokines or the products of a bone development regulatory gene, such as those listed in Table 3, and variants thereof. A plurality of genes may be delivered in combination. The BMP genes described by Wozney, J. M. et al., Science 242:1528-34 (1988), incorporated herein by reference, are well characterized and are, therefore, considered more preferred for delivery.
TABLE 3
Cytokines Involved in Bone or Cartilage Regeneration:
1) TGF-beta superfamily, particularly including BMP-1,2,7,12,13,14, and GDFs (growth differentiating factors)
2) LIF (Leukemia inhibitory factor)
3) OSM (oncostatin-M)
4) CT-1 (cardiotrophin-1)
5) IL-3,4,6,8,11 (Interleukins)
6) PDGF-AA,AB,BB
7) IGFs
8) FGFs
9) TNF-alpha
10) GM-CSF
11) EGF, HG-EGF
12) VEGF
13) IP-10
14) PF-4
15) MCP-1
16) HGF
17) RANTES
18) PGE (Prostaglandins)
19) Decorin
Bone Development Regulatory Genes:
1) Osf2/Cbfa1
This application is particularly enhanced by employing the described endoscopic modification of the microseeding instrument which further diminishes the trauma caused by the procedure.
The invention is not intended to be limited to the preferred embodiments nor to the specific examples, but is intended to include all such modifications and variations of the invention as fall within the scope of the appended claims.
__________________________________________________________________________# SEQUENCE LISTING- (1) GENERAL INFORMATION:- (iii) NUMBER OF SEQUENCES: 4- (2) INFORMATION FOR SEQ ID NO:1:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 4283 base (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular- (ii) MOLECULE TYPE: other nucleic acid#= "Plasmid DNA"SCRIPTION: /desc- (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: join(713..72 - #1, 981..1250)- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:- GGGCGAATTC GATCCTGCAG GTCCGTTACA TAACTTACGG TAAATGGCCC GC - #CTGGCTGA 60- CCGCCCAACG ACCCCCGCCC ATTGACGTCA ATAATGACGT ATGTTCCCAT AG - #TAACGCCA 120- ATAGGGACTT TCCATTGACG TCAATGGGTG GAGTATTTAC GGTAAACTGC CC - #ACTTGGCA 180- GTACATCAAG TGTATCATAT GCCAAGTACG CCCCCTATTG ACGTCAATGA CG - #GTAAATGG 240- CCCGCCTGGC ATTATGCCCA GTACATGACC TTATGGGACT TTCCTACTTG GC - #AGTACATC 300- TACGTATTAG TCATCGCTAT TACCATGGTG ATGCGGTTTT GGCAGTACAT CA - #ATGGGCGT 360- GGATAGCGGT TTGACTCACG GGGATTTCCA AGTCTCCACC CCATTGACGT CA - #ATGGGAGT 420- TTGTTTTGGC ACCAAAATCA ACGGGACTTT CCAAAATGTC GTAACAACTC CG - #CCCCATTG 480- ACGCAAATGG GCGGTAGGCG TGTACGGTGG GAGGTCTATA TAAGCAGAGC TC - #GTTTAGTG 540- AACCGTCAGA TCGCCTGGAG ACGCCATCCA CGCTGTTTTG ACCTCCATAG AA - #GACACCGG 600- GACCGATCCA GCCTCCGCGG CCGGGAACGG TGCATTGGAA CGGACTCTAG AG - #GATCCCAA 660- GGCCCAACTC CCCGAACCAC TCAGGGTCCT GTGGACAGCT CACCTAGCTG CA - # ATG 715# Met# 1- GCT ACA GGTAAGCGCC CCTAAAATCC CTTTGGCACA ATGTGTCCTG AG - #GGGAGAGG 771Ala Thr- CAGCGACCTG TAGATGGGAC GGGGGCACTA ACCCTCAGGG TTTGGGGTTC TG - #AATGTGAG 831- TATCGCCATC TAAGCCCAGT ATTTGGCCAA TCTCAGAAAG CTCCTGGCTC CC - #TGGAGGAT 891- GGAGAGAGAA AAACAAACAG CTCCTGGAGC AGGGAGAGTG TTGGCCTCTT GC - #TCTCCGGC 951- TCCCTCTGTT GCCCTCTGGT TTCTCCCCA GGC TCC CGG ACG TCC - # CTG CTC CTG1004# Gly Ser A - #rg Thr Ser Leu Leu Leu# 10- GCT TTT GGC CTG CTC TGC CTG CCC TGG CTT CA - #A GAG GGC AGT GCC TTC1052Ala Phe Gly Leu Leu Cys Leu Pro Trp Leu Gl - #n Glu Gly Ser Ala Phe# 25- CCA ACC ATT CCC TTA TAT CAA GCT TCG ATA TC - #C CGG GTT AAT AGT GAC1100Pro Thr Ile Pro Leu Tyr Gln Ala Ser Ile Se - #r Arg Val Asn Ser Asp# 40- TCT GAA TGT CCC CTG TCC CAC GAT GGG TAC TG - #C CTC CAT GAT GGT GTG1148Ser Glu Cys Pro Leu Ser His Asp Gly Tyr Cy - #s Leu His Asp Gly Val# 55- TGC ATG TAT ATT GAA GCA TTG GAC AAG TAT GC - #A TGC AAC TGT GTT GTT1196Cys Met Tyr Ile Glu Ala Leu Asp Lys Tyr Al - #a Cys Asn Cys Val Val# 75- GGC TAC ATC GGG GAG CGA TGT CAG TAC CGA GA - #C CTG AAG TGG TGG GAA1244Gly Tyr Ile Gly Glu Arg Cys Gln Tyr Arg As - #p Leu Lys Trp Trp Glu# 90- CTG CGC TGAAAACACC GTGCGGCCGC ATCGATCTCG AGCATGCATC TA - #GAGGGCCC1300Leu Arg- TATTCTATAG TGTCACCTAA ATGCTAGAGC TCGCTGATCA GCCTCGACTG TG - #CCTTCTAG1360- TTGCCAGCCA TCTGTTGTTT GCCCCTCCCC CGTGCCTTCC TTGACCCTGG AA - #GGTGCCAC1420- TCCCACTGTC CTTTCCTAAT AAAATGAGGA AATTGCATCG CATTGTCTGA GT - #AGGTGTCA1480- TTCTATTCTG GGGGGTGGGG TGGGGCAGGA CAGCAAGGGG GAGGATTGGG AA - #GACAATAG1540- CAGGCATGCT GGGGATGCGG TGGGCTCTAT GGAACCAGCT GGGGCTCGAG CA - #TGCAAGCT1600- TGAGTATTCT ATAGTGTCAC CTAAATAGCT TGGCGTAATC ATGGTCATAG CT - #GTTTCCTG1660- TGTGAAATTG TTATCCGCTC ACAATTCCAC ACAACATACG AGCCGGAAGC AT - #AAAGTGTA1720- AAGCCTGGGG TGCCTAATGA GTGAGCTAAC TCACATTAAT TGCGTTGCGC TC - #ACTGCCCG1780- CTTTCCAGTC GGGAAACCTG TCGTGCCAGC TGCATTAATG AATCGGCCAA CG - #CGCGGGGA1840- GAGGCGGTTT GCGTATTGGG CGCTCTTCCG CTTCCTCGCT CACTGACTCG CT - #GCGCTCGG1900- TCGTTCGGCT GCGGCGAGCG GTATCAGCTC ACTCAAAGGC GGTAATACGG TT - #ATCCACAG1960- AATCAGGGGA TAACGCAGGA AAGAACATGT GAGCAAAAGG CCAGCAAAAG GC - #CAGGAACC2020- GTAAAAAGGC CGCGTTGCTG GCGTTTTTCG ATAGGCTCCG CCCCCCTGAC GA - #GCATCACA2080- AAAATCGACG CTCAAGTCAG AGGTGGCGAA ACCCGACAGG ACTATAAAGA TA - #CCAGGCGT2140- TTCCCCCTGG AAGCTCCCTC GTGCGCTCTC CTGTTCCGAC CCTGCCGCTT AC - #CGGATACC2200- TGTCCGCCTT TCTCCCTTCG GGAAGCGTGG CGCTTTCTCA TAGCTCACGC TG - #TAGGTATC2260- TCAGTTCGGT GTAGGTCGTT CGCTCCAAGC TGGGCTGTGT GCACGAACCC CC - #CGTTCAGC2320- CCGACCGCTG CGCCTTATCC GGTAACTATC GTCTTGAGTC CAACCCGGTA AG - #ACACGACT2380- TATCGCCACT GGCAGCAGCC ACTGGTAACA GGATTAGCAG AGCGAGGTAT GT - #AGGCGGTG2440- CTACAGAGTT CTTGAAGTGG TGGCCTAACT ACGGCTACAC TAGAAGGACA GT - #ATTTGGTA2500- TCTGCGCTCT GCTGAAGCCA GTTACCTTCG GAAAAAGAGT TGGTAGCTCT TG - #ATCCGGCA2560- AACAAACCAC CGCTGGTAGC GGTGGTTTTT TTGTTTGCAA GCAGCAGATT AC - #GCGCAGAA2620- AAAAAGGATC TCAAGAAGAT CCTTTGATCT TTTCTACGGG GTCTGACGCT CA - #GTGGAACG2680- AAAACTCACG TTAAGGGATT TTGGTCATGA GATTATCAAA AAGGATCTTC AC - #CTAGATCC2740- TTTTAAATTA AAAATGAAGT TTTAAATCAA TCTAAAGTAT ATATGAGTAA AC - #TTGGTCTG2800- ACAGTTACCA ATGCTTAATC AGTGAGGCAC CTATCTCAGC GATCTGTCTA TT - #TCGTTCAT2860- CCATAGTTGC CTGACTCCCC GTCGTGTAGA TAACTACGAT ACGGGAGGGC TT - #ACCATCTG2920- GCCCCAGTGC TGCAATGATA CCGCGAGACC CACGCTCACC GGCTCCAGAT TT - #ATCAGCAA2980- TAAACCAGCC AGCCGGAAGG GCCGAGCGCA GAAGTGGTCC TGCAACTTTA TC - #CGCCTCCA3040- TCCAGTCTAT TAATTGTTGC CGGGAAGCTA GAGTAAGTAG TTCGCCAGTT AA - #TAGTTTGC3100- GCAACGTTGT TGGCATTGCT ACAGGCATCG TGGTGTCACG CTCGTCGTTT GG - #TATGGCTT3160- CATTCAGCTC CGGTTCCCAA CGATCAAGGC GAGTTACATG ATCCCCCATG TT - #GTGCAAAA3220- AAGCGGTTAG CTCCTTCGGT CCTCCGATCG TTGTCAGAAG TAAGTTGGCC GC - #AGTGTTAT3280- CACTCATGGT TATGGCAGCA CTGCATAATT CTCTTACTGT CATGCCATCC GT - #AAGATGCT3340- TTTCTGTGAC TGGTGAGTAC TCAACCAAGT CATTCTGAGA ATAGTGTATG CG - #GCGACCGA3400- GTTGCTCTTG CCCGGCGTCA ATACGGGATA ATACCGCGCC ACATAGCAGA AC - #TTTAAAAG3460- TGCTCATCAT TGGAAAACGT TCTTCGGGGC GAAAACTCTC AAGGATCTTA CC - #GCTGTTGA3520- GATCCAGTTC GATGTAACCC ACTCGTGCAC CCAACTGATC TTCAGCATCT TT - #TACTTTCA3580- CCAGCGTTTC TGGGTGAGCA AAAACAGGAA GGCAAAATGC CGCAAAAAAG GG - #AATAAGGG3640- CGACACGGAA ATGTTGAATA CTCATACTCT TCCTTTTTCA ATATTATTGA AG - #CATTTATC3700- AGGGTTATTG TCTCATGAGC GGATACATAT TTGAATGTAT TTAGAAAAAT AA - #ACAAATAG3760- GGGTTCCGCG CACATTTCCC CGAAAAGTGC CACCTGACGT CTAAGAAACC AT - #TATTATCA3820- TGACATTAAC CTATAAAAAT AGGCGTATCA CGAGGCCCTT TCGTCTCGCG CG - #TTTCGGTG3880- ATGACGGTGA AAACCTCTGA CACATGCAGC TCCCGGAGAC GGTCACAGCT TG - #TCTGTAAG3940- CGGATGCCGG GAGCAGACAA GCCCGTCAGG GCGCGTCAGC GGGTGTTGGC GG - #GTGTCGGG4000- GCTGGCTTAA CTATGCGGCA TCAGAGCAGA TTGTACTGAG AGTGCACCAT AT - #GCGGTGTG4060- AAATACCGCA CAGATGCGTA AGGAGAAAAT ACCGCATCAG GCGCCATTCG CC - #ATTCAGGC4120- TGCGCAACTG TTGGGAAGGG CGATCGGTGC GGGCCTCTTC GCTATTACGC CA - #GCTGGCGA4180- AAGGGGGATG TGCTGCAAGG CGATTAAGTT GGGTAACGCC AGGGTTTTCC CA - #GTCACGAC4240# 428 - #3ATTGTAAT ACGACTCACT ATA- (2) INFORMATION FOR SEQ ID NO:2:- (i) SEQUENCE CHARACTERISTICS:#acids (A) LENGTH: 93 amino (B) TYPE: amino acid (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: protein- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:- Met Ala Thr Gly Ser Arg Thr Ser Leu Leu Le - #u Ala Phe Gly Leu Leu# 15- Cys Leu Pro Trp Leu Gln Glu Gly Ser Ala Ph - #e Pro Thr Ile Pro Leu# 30- Tyr Gln Ala Ser Ile Ser Arg Val Asn Ser As - #p Ser Glu Cys Pro Leu# 45- Ser His Asp Gly Tyr Cys Leu His Asp Gly Va - #l Cys Met Tyr Ile Glu# 60- Ala Leu Asp Lys Tyr Ala Cys Asn Cys Val Va - #l Gly Tyr Ile Gly Glu# 80- Arg Cys Gln Tyr Arg Asp Leu Lys Trp Trp Gl - #u Leu Arg# 90- (2) INFORMATION FOR SEQ ID NO:3:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 24 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid#= "PCR Primer"ESCRIPTION: /desc- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:# 24ATGT CCCC- (2) INFORMATION FOR SEQ ID NO:4:- (i) SEQUENCE CHARACTERISTICS:#pairs (A) LENGTH: 20 base (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear- (ii) MOLECULE TYPE: other nucleic acid#= "PCR Primer"ESCRIPTION: /desc- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:# 20 CTAG__________________________________________________________________________
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Direct gene transfer of genetic material into an external or internal target cell site ("microseeding"), in optional combination with a wound treatment chamber, are particularly effective as a means of obtaining long term expression of native or non-native polypeptides in a host. A wide variety of proteins and materials can be expressed, either for secretion into the general blood and lymphatic system, or to alter the properties of the protein, for example, to not express proteins eliciting an immune response. The use of the optional wound chamber system for gene transfer to skin target sites also allows non-invasive assessment of the success of transfer by assaying for the presence of the expressed protein in wound fluid, in contrast to the prior art use of invasive techniques, such as biopsies, in order to achieve the same assessment of early expression.
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This is a division of application Ser. No. 380,071, filed May 20, 1982.
CROSS-REFERENCES TO RELATED APPLICATIONS
Applicants claim priority under 35 USC 119 for application No. P 31 22 341.9, filed June 5, 1981 in the Patent Office of the Federal Republic of Germany.
The disclosure of assignee's copending application Ser. No. 206,282, filed Nov. 12, 1980, is incorporated herein to further show the state of the art of self extinguishing fine particulate expandable styrene polymers.
BACKGROUND OF THE INVENTION
The field of the invention is fire retardant, fine particulate, expandable styrene polymers for the preparation of molded articles. The present invention is particularly concerned with expandable, particulate molding compositions of styrene polymers containing organic halogen compounds and an epoxidation product.
The state of the art of expandable polystyrene may be ascertained by reference to the Kirk-Othmer, "Encyclopedia of Chemical Technology," 2nd Edition, Vol. 9 (1966) under the section entitled "Foamed Plastics," pages 847-884, particularly pages 852, 853 and 855 where polystyrene is disclosed, and Vol. 19 (1969) under the section entitled "Styrene Plastics," pages 85-134, particularly pages 116-120, where polystyrene foams are disclosed and pages 120, 121 where prior art self-extinguishing polystyrene foams are disclosed and U.S. Pat. Nos. 3,755,209; 4,029,614; 4,192,922; 4,228,244 and 4,281,036 the disclosures of which are incorporated herein.
The preparation of the epoxidation additives useful in the present invention is disclosed in West German Published Application No. 2,436,817; the article by Swern in Organic Peroxides, Vol. II, pp. 355-533 (1971) and the article by Weigert in Chemikerzeitung #99 at page 109 (1975).
Shaped articles of foamed material are produced commercially by expanding fine particulate expandable styrene polymers in molds. In this procedure, the fine-particulate styrene polymers are first heated with steam or hot gases to temperatures above their softening points and as a result thereof foaming into discrete particles takes place. This process step, wherein the particles have room for free expansion, is called pre-foaming as disclosed in U.S. Pat. No. 4,228,244. The pre-foamed styrene polymers first are stored and then are further expanded in a pressure-resistant mold, which however is not gas-tight, by renewed heating with steam. Due to spatial limitations, the particles fuse together into a molded body corresponding to the cavity of the mold used. This second process step is termed final foaming as also disclosed in U.S. Pat. No. 4,228,244. The molded object, after final foaming, is cooled inside the mold until the inside temperature drops below the softening point. Otherwise, deformation is incurred. The time interval allowing the earliest removal of the molded object from the mold without deformation is ordinarily call the "minimum mold dwell time". It is also possible to use as a measurement, the drop in the inside mold pressure to near atmospheric as a criterion for removing the shaped object from the mold. After being removed from the mold, the molded object most often is stored until fully cooled and thereafter it can be cut into foamed sheets or panels for use as thermal insulation.
Especially when flame retardant organic halogen compounds are added, the production of expandable styrene polymers often results in products having irregular cell structures. Such foamed blocks tend to a significant collapse of their sides (block shrinkage) some time after being removed from the mold, and furthermore they are also less fused inside the block. Consequently foamed panels cut from a block are of varying grades. Furthermore the blocks having defective sides must be trimmed, whereby an undesired waste is incurred.
Another limitation exists in relation to pre-foaming. Part of the pre-foaming beads shrink and accordingly the low densities desired cannot be achieved. The shrinkage of the prefoam beads is related to a high loss in expanding agent, whereby the above mentioned uneven fusing, takes place and hence the collapse of the blocks at the sides is enhanced. Furthermore, the surface of the finished objects has an uneven appearance, which is particularly bothersome for the manufacture of panels which are visible to the public.
U.S. Pat. No. 3,755,209 discloses that by adding hydroxylamines to expandable styrene polymers made self-extinguishing by halogen compounds, it is possible to improve the above cited processing problems. U.S. Pat. No. 4,029,614 discloses a similar effect by adding slight amounts of amines free of hydroxyl groups, and U.S. Pat. No. 4,192,922 defines amine-substituted triazine derivatives for remedying these known processing problems.
SUMMARY OF THE INVENTION
It is true that the additives disclosed in U.S. Pat. Nos. 3,755,209; 4,029,614 and 4,192,922 often improve the product quality significantly.
Nevertheless they still fail to provide fully satisfactory products. The poor reproducibility of the properties of the product is most bothersome of all.
It is an object of the present invention to provide compounds which, in low concentrations, will prevent the occurrence of the above mentioned drawbacks such as uneven cellularity, fusing and block shrinkage. Moreover such compound additives should not be degraded, as regards effectiveness, by the auxiliary materials required for polymerization such as initiators, suspension-assisting agents or other additives such as flame proofing agents or expanding agents, whereby the product quality achieved is reproducible.
It has been found, according to the present invention, that epoxidation products of aliphatic hydrocarbons which are soluble in the monomers to be polymerized and of which the epoxidated aliphatic chain comprises from about 6 to 18 carbon atoms, particularly from 10 to 14 carbon atoms, favorably affect the important processing properties of "fusing quality" and "block shrinkage" of foamed blocks made from styrene polymers containing expandable, organic halogen compounds. These epoxidation products are also free from the above mentioned limitations relating to amine addition. The styrene polymers obtained by the present invention offer greater processing latitude, that is, foamed blocks having good fusing and excellent surfaces are always obtained for various steam pressures when they are final foamed in the mold.
According to the present invention expanded, flame retardant, styrene polymers having an improved minimum mold dwell time and reduced block shrinkage are prepared by:
(a) mixing together styrene or a mixture of styrene and a copolymerizable monomer with an organic halogen compound and an expanding agent in an aqueous dispersion;
(b) adding before or during polymerization to the mixture of (a) in proportions of 0.0001 to 1%, preferably from 0.001 to 0.1% by weight referred to the monomers to be polymerized of an epoxidation product of an aliphatic hydrocarbon having an epoxidated chain containing from 6 to 18 carbon atoms, this epoxidation product being soluble in the organic phase of the suspension (the monomers);
(c) carrying out a polymerization in the aqueous suspension of (a) and (b) using radical forming initiators at temperatures of 80° C.-130° C. to form expandable particles;
(d) pre-foaming the expandable particles resulting from (c);
(e) ageing the pre-foamed particles of (d); and
(f) molding the pre-foamed and aged particles of (e) in a pressure resistant mold.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The epoxidation products of aliphatic hydrocarbons conceived according to the present invention are both those obtained from straight chain and from branched hydrocarbons. The epoxy group can be present both as a terminal group and within the chain, also in single or multiple form.
Suitable epoxidation products are for instance 1,2-epoxyhexane, 3,4-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, 1,2-epoxyoctadecane, in particular 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, branched-chain 1,2-epoxy-2-butylocane and 1,2-epoxybutyldecane.
Again the epoxidation products may be based on mixtures of hydrocarbons such as the corresponding C 12 /C 13 blends and products designated as μ-C 12 /C 13 -epoxyalkanes comprise both terminal epoxy groups and epoxy groups distributed over the chain.
The following epoxidation products with multiple epoxy groups are illustrative: 1,2,5,6-bis-epoxyhexane, 1,2,9,10-bis-epoxydecane and 1,2,7,8-bis-epoxyoctane.
These epoxidation products are known to the prior art and no protection is claimed for the production of the epoxidation products within the scope of the present invention. Their production takes place by prior art methods such as disclosed by Swern in Organic Peroxides, Vol II, pp. 355-533 (1971) or in West German Published Application No. 2,436,817, especially as disclosed by Weigert in Chemikerzeitung #99, page 109 (1975).
A suitable method for preparing the styrene polymers of the present invention which contain an organic halogen compound and also an expanding agent is carried out according to the prior art by polymerizing styrene or a mixture of styrene and comonomers polymerizable therewith in an aqueous suspension using radical-forming initiators at temperatures in excess of 80° C. The suspension polymerization is carried out in the presence of the flame-retarding organic halogen compounds and the expanding agents and the epoxidation product soluble in the organic phase of the suspension is added to the aliphatic hydrocarbons before or during the polymerization.
As disclosed in U.S. Pat. No. 4,228,244 the radical forming initiators include benzoylperoxide, laurylperoxide, ter.-butylperbenzoate, ter.-butylyseroctate, di-ter. butylperoxide or mixtures as well as unstable azo compounds such as azobisisobutyronitrite. These initiators generally are used in proportions between 0.01 and 1% by weight referred to the monomers. The temperature of polymerization is preferably between 80° C. and 130° C.
Definite factors regarding the effectiveness of the epoxidation products used include:
(a) good solubility of the epoxidation products in the organic phase of the suspension and
(b) good solubility of the organic halogen compound (flame proofing means) in the epoxidation products.
The epoxide products of the present invention are used in proportions of about 0.0001 to 1, preferably however from 0.001 to 0.1% by weight referred to the weight of monomers to be polymerized. In every instance the amount to be used, measured with respect to the amount of the organic halogen compound added, is small. The substances can be added either to the organic phase or to the reaction mixture before or during polymerization up until the end of the polymerization. The preferred addition of the epoxide products is during the polymerization conversion of 50 to 90%. This addition is made possible together with the expanding agent. The amount of epoxide, and the time of the addition, is each independent of the temperature profile of the polymerization and independent of the kind of the respective initiator used. The amount and the kind of epoxide however depends on the kind of halogen compound incorporated and this is easily ascertained empirically.
The raw materials for the production of the styrene polymers of the present invention are mixtures of monomers containing at least 50% by weight of styrene and possibly components copolymerizable therewith for instance alpha-methylstyrene, nuclear-halogenated styrenes, acrylonitrile, esters of acrylic- or methacrylic acid with alcohols having 1 to 8 C atoms, N-vinyl compounds such as N-vinylcarbazole, and also slight amounts of butadiene or divinylbenzene.
The organic halogen compounds used as flame retardant agents are especially bromine compounds such as brominated oligomers of butadiene or of isoprene, at an average degree of polymerization from 2 to 20, the bromination being full or partial. Examples are 1,2,5,6-tetrabromocyclooctane, 1,2,5,6,9,10-hexabromocyclododecane, brominated polybutadiene with a polymerization degree for instance of 3 to 15. The organic halogen compounds may be contained in the expandable styrene polymer in proportions of 0.05 to 1% by weight, when added as flame-proofing agents in proportions of 0.4 to 3% by weight to the expandable styrene polymer. In addition to the halogen compounds as the flame proofing means, the known synergists can be used in conventional amounts, preferably organic peroxides, in particular those having a half-value time of at least two hours at 373° K.
The suspension stablilizers used are suitably organic protective colloids such as polyvinyl alcohol, polyvinyl pyrrolidone or polyvinyl pyrrolidone copolymers or mineral suspension auxiliaries such as finely distributed tricalcium phosphate, barium phosphate etc.
The expanding agents used in the process of the invention are for instance such aliphatic hydrocarbons as propane, butane, pentane, hexane, cycloaliphatic hydrocarbons such as cyclohexane, or halogen hydrocarbons such as dichlorodifluoromethane and 1,2,2-trifluoro-1,1,2-trichloroethane. Mixtures of such compounds can also be used. The proportion of expanding agents used is 3 to 15% by weight, preferably between 5 and 8% by weight referred to the styrene polymer.
The expandable styrene polymers moreover can contain such additives as dyes, fillers and stabilizers. Once prepared, the expandable polymers are present in fine-particulate form conventionally as beads and in general are 0.4 to 3 mm in diameter. The pre-foamed expandable styrene beads are further foamed by the conventional final foaming method by being heated in molds which close without being gas-tight and are sintered into foamed shapes corresponding in their dimensions to the inside cavity of the molds used. The styrene polymers of the present invention can be processed into extraordinarily dimensionally stable shaped bodies. Once removed from the mold, foam blocks 1×1×0.5 m show only an extremely slight tendency to have collapsing sides. The foam shapes or blocks are further characterized by an especially good fusing of the individual particles. Accordingly they evince an especially good mechanical stability.
EXAMPLES
A mixture of 100 parts by weight of fully desalted water, 100 parts by weight of styrene, 0.4 parts by weight of benzoyl peroxide, 0.1 parts by weight of tertiary butyl perbenzoate, 0.75 parts by weight of hexabromocyclododecane, 0.30 parts by weight of dicumyl peroxide and the amount listed in Table 1 of the corresponding epoxy alkanes (dissolved in styrene) was heated with stirring to 90° C. in a pressure-resistant agitation vessel made of a corrosion-proof steel. This is true in every case of the examples tabulated. After 2 hours heating at 90° C., 5 parts of a 2% aqueous solution of polyvinyl alcohol having a saponification number of 140 is added. After another 2 hours, 7 parts by weight of a mixture of 25 parts by weight of isopentane and 75% by weight of n-pentane are added within 10 to 15 minutes. This mixture is heated, after another hour, to 90° to 120° C. and is kept at this temperature for 6 hours.
Following the termination of the polymerization cycle, cooling is carried out, the bead polymer so obtained is separated from the aqueous phase, dried and sifted.
The bead fraction between 1 and 2 mm in diameter is prefoamed in a continuous Rauscher type agitation pre-foamer with flowing steam to a bulk weight of 15 grams/liter, then was interim-stored or aged for 24 hours and next was foamed out into a foam block mold of the size 100×50×100 cm type Rauscher at various vapor pressures. Table 1 lists the test values. Each example is repeated at least five times. The standard deviations are shown next to the test values and these standard deviations are quite clearly higher for the control tests than for the examples of the invention.
TABLE 1__________________________________________________________________________ Addition Additive in Vapor Degree Amount Bulk Steaming Pres- of Block Cell % By Weight Time sure Fusing Shrinkage Block StructureAdditive Weight g/l.sup.1 Sec..sup.2 bar.sup.3 %.sup.4 %.sup.5 Surface.sup.6 Cells/mm.sup.7__________________________________________________________________________1. Examples of the inventionμ-C.sub.12 /C.sub.13 -- 0.01 0.4 ± 0.2 20 1.8 80 ± 10 0.4 ± 0.2 Good 4 to 6 50 1.5 90 ± 10 0.3 ± 0.1 Good 4 to 6 20 1.5 80 ± 10 0.5 ± 0.2 Good 4 to 6epoxy 0.005 0.8 ± 0.2 20 1.8 80 ± 10 0.6 ± 0.2 Good 4 to 8alkane 50 1.5 80 ± 10 0.6 ± 0.2 Good 4 to 8 20 1.5 70 ± 20 0.6 ± 0.2 Good 4 to 81,2,9,10-bis- 0.005 0.5 ± 0.2 20 1.8 80 ± 10 0.5 ± 0.3 Good 4 to 8Epoxy decane1,2-epoxy- 0.005 20 1.8 80 ± 10 0.4 ± 0.2 Good 4 to 8tetradecaneμ-C.sub.12 /C.sub.13 -- 0.005 0.4 ± 0.2 20 1.8 80 ± 10 0.4 ± 0.2 Good 4 to 6Epoxy 50 1.5 90 ± 10 0.3 ± 0.1 Good 4 to 6alkane dis- 20 1.5 80 ± 10 0.5 ± 0.2 Good 4 to 6solved inpentane2. Control testsN,N--Dicyclo- 0.005 0.5 ± 0.2 20 1.8 70 ± 30 0.5 ± 0.5 Good 2 to 10hexylamine 20 1.5 60 ± 40 0.7 ± 0.5 Good 2 to 10N--Tetradecyl- 0.005 0.4 ± 0.2 20 1.8 60 ± 40 0.8 ± 0.7 Good 2 to 10amine 20 1.5 70 ± 20 0.6 ± 0.6 Good 2 to 102,4-Diamino- 0.005 0.8 ± 0.4 20 1.8 60 ± 40 1.0 ± 0.5 Good 10 to 206-nonyl-1,3, 20 1.5 70 ± 30 1.2 ± 0.6 Good 10 to 205-triazineBis-(hydroxi- 0.05 1.0 ± 0.5 20 1.8 60 ± 40 1.5 ± 0.5 Good 2 to 10ethyl)-dode- 20 1.5 60 ± 40 1.3 ± 0.5 Good 2 to 10cylamine__________________________________________________________________________ .sup.1 addition in bulk weight of the prefoamed beads following pneumatic conveyance into a silo and after 24 hours of interim .sup.2 the steaming time is the time from the stated steam pressure being reached in the block mold until the steam supply valves are .sup.3 steam pressure in the block .sup.4 the fusing degree is the ratio of the number of torn particles to the total number of particles multiplied by 100 (= %); the test object is a foam panel 100 × 100 × 5 cm in .sup.5 block shrinkage is the collapse of the sides when measured 24 hour after production of the block by measuring the block thickness from the center of a large side to the opposite one and at right angles to both; the difference between the inside mold dimension at this location and the block thickness at this site in percent of the inside mold dimension is the block shrinkage .sup.6 the block surface is designated as "good" when no collapsed beads with a molten appearance can be observed .sup.7 the microscopic determination of the cell number is determined by taking panels from ten different sites of the block in every test; the values stated are always the highest and lowest cell numbers found; the closer the values to each other, the more homogeneous is the cell structure of the block
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Fine particulate expandable flame retardant styrene polymers having an improved minimum mold dwell time and reduced block shrinkage are prepared by:
(a) mixing together styrene monomer or a mixture of styrene and a cpolymerizable monomer with an organic halogen compound and an expanding agent in an aqueous disperson;
(b) adding before or during polymerization to the mixture of (a) from 0.0001 to 0.1% by weight of an epoxidation product of an aliphatic hydrocarbon of which the epoxidated aliphatic chain comprises from 6 to 18 C atoms, this epoxidation product being soluble in the monomers;
(c) carrying out a polymerization in the aqueous suspension of (a) and (b) using radical forming initiators at temperatures of 80° C.-130° C. to form expandable particles;
(d) pre-forming the expandable particles resulting from (c);
(e) ageing the pre-formed particles of (d); and
(f) molding the pre-formed and aged particles of (e) in a pressure resistant mold.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of International Patent Application PCT/DK99/00259 with an international filing date of May 7, 1999, now abandoned. This application is based on application No. 0631/98 filed in Denmark on May 7, 1998, the contents of which are incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a clip-on shield for spectacles wherein the shield is secured to the spectacles by means of a clip-on device to allow occasional use thereof over ordinary lenses.
The invention further relates to a combination of a removable shield and a pair of spectacles.
The term “spectacles” is used herein to designate the well known optical accessory which basically comprises a pair of lenses made from glass or other refractive material, usually made according to an optician's prescription and intended for being worn by a wearer in order for him to enjoy an optically corrected view by seeing through them, and provided with fitting means for conveniently securing the lenses in the preferred in-use position in which the wearer is offered the possibility of looking straight through the respective lenses while both eyes have generally parallel directions of vision.
Occasionally a bespectacled person may want to use a pair of auxiliary lenses together with his or her spectacles, most often a pair of tinted lenses adapted for reducing sunglare. Although such items are referred to herein as lenses, this is not intended to signify that they would necessarily include optically refractive means, in most cases they rather include some type of optical filters known in the art.
As generally known in the art, the occasional use of auxiliary lenses by bespectacled persons is facilitated by fitting the lenses in the form of a detachable shield, i.e. in the form of an accessory with fitting means adapted for detachable fastening onto the spectacles in such a manner that the shield lenses are secured in a position to substantially cover the ordinary lenses in a slightly spaced surface to surface relation. Such a shield essentially comprises two shield lenses, a bridge designed to straddle over the wearer's nose and means for detachable fitting of the shield acccessory over the spectacles.
2. Description of the Prior Art
DE patent No. 27 18 445 teaches an accessory shield which comprises two clips or clamps arranged to allow the accessory shield to be mounted on the spectacles by being shifted downwards over the spectacles from above and constructed to obtain flexible securing by means of tongues which engage and clamp the front and the back of each of the lenses in a substantially vertically extending area adjacent to the inner rim, i.e. generally close to the wearer's nose. Each of the clips is further provided with a connecting branch adapted for abutment on a top frame portion of the spectacles.
Although simple and commonly used, shields of this general type are associated with certain drawbacks. From an aesthetical point of view, they are rarely accomplished since they easily slide and become awry. Usually, the abutment on the top frame of the spectacles is not sufficient to ensure stable centering and perfect orientation, since most often the top frame of the spectacles extends in a curved manner, which means that the shield comes to rest on a curved area where the shield is likely to slide sideways. In order to provide such a shield with the capacity of fitting over any among a range of spectacles where the spacing between the inner rims of the lenses and the corresponding rims of the frame, respectively, varies, the clips must be adapted with a width sufficient to straddle the wider spacing. Hereby the clips will on the majority of spectacles, where the rim spacing is average or below average, engage the lenses at zones relatively far away from the rims.
Moreover, it is difficult to ensure stable fitting of the flexible clips onto any thickness of frames and lenses, and since different wearers wear different thicknesses of frames and lenses, some wearers are unable to use shields with this type of fastening means.
During mounting and dismounting the flexible clips are to slide up and down over the support areas in the full vertical extent of the clip which involves a risk of scratching both the front and the back of the lenses. Often, the movement becomes irregular with lateral displacements due to the two spring clips engaging curved portions of respective lens rims, while the user attempts to displace the shield vertically. This means that the area exposed to such scratching is comparatively large. In case of lenses made of glass, this does not present a problem, however, in case of lenses made from plastics, it is not acceptable.
Since many wearers prefer plastic lenses, e.g. because they favor low weight or shatterproofness, fastening means which do not cause scratching problems are very much in demand.
The movement for applying the shield onto the spectacles as well as the movement for removing the shield are generally oriented parallel to the plane of the glass surfaces. This manipulation is difficult to accomplish without the user having to remove the spectacles.
U.S. Pat. No. 5,920,369 discloses a removable shield with a central connection bridge provided with hook projections adapted to engage the spectacle nose bridge. The shield may also be provided with guide pegs in lateral positions, oriented generally perpendicular to the glasses and adapted to engage apertures in the spectacle frame adjacent the hinges. This shield is applied from the front. Application of this shield neccesitates registrering the hook projections with the nose bridge and registering the lateral pegs. Generally the user will register first the hook projections and will subsequently register the pegs, one at a time. This shield achieves a good fit and a good hold on the spectacles, but at the cost of a somewhat complicated handling which the user may not find easy, at least not unless the spectacles are removed during this operation.
U.S. Pat. No. 5,614,963 illustrates a combination of a removable shield and a pair of spectacles in which the spectacle frame is provided with lateral protuberances, each protuberance being provided with a bore, which bore is oriented generally perpendicular to the glass surfaces. The shield is provided with lateral pin members adapted for registering in respective bores. The pin members may be bifurcated with fork ends adapted for securing the shield. The part of the shield intermediate the pegs is secured to the glasses by means of patches of mating hook and loop pile fastening material.
Thus, this prior art relies on dedicated attachment means on the eyeglasses which may create an undesirable bulky look. The parts require delicate manufacturing and delicate matching, and additional means need to be provided in order to secure a good fit.
SUMMARY OF THE INVENTION
The invention, in a first aspect, provides a clip-on shield for a pair of spectacles, which pair of spectacles comprises a pair of spectacle glasses, a spectacle frame with lateral portions, which lateral portions provide frame guide faces oriented generally perpendicular to the plane of the spectacle glass surfaces, and temples connected with the spectacle frame by hinges, said shield comprising a shield frame, shield glasses, lock means for securing said shield to the spectacle frame and shield guide faces, wherein said shield guide faces are adapted for cooperation with the frame guide faces so as to permit sliding said shield along a direction generally perpendicular to the plane of the spectacle glass surfaces and into a secured position, while preserving the mutual orientation of said shield and the spectacle glasses during a final stage of approach.
This shield is adapted for use on a pair of spectacles which comprises guide faces. The guide faces may be provided by parts of the spectacle frame, e.g. parts of the hinges. Thus, the guide faces may be small and unobtrusive in the appearance of the spectacles. During application of this shield, the mutual orientation of the shield and the glasses is controlled during a final stage of approach. This avoids any risk of accidentally contacting the shield glasses with the spectacle glasses.
The control of the orientation should generally at least apply to the inclination or the attitude of the shield relative to the glasses. The control of the orientation should not be too narrow in respect of the bearing or the azimuth angle, as it should allow fitting one lateral side of the shield on the glasses prior to the fitting of the opposite side. The control of the orientation by mutually cooperating guide faces according to the invention does not exclude the option of backing-up the control by other motion limiters, such as spacers, etc. The control of the orientation should be suitable to ensure that no accidental, undesired contact between the shield glasses and the spectacle glasses may occur during this succession of steps. Hereby the invention substantially facilitates application of the shield.
A preferred embodiment calls for spacer means adapted to maintain a spacing between the shield glasses and the spectacle glasses. The spacer means preferably comprises a pad of soft material. This provides a positive spacing between the glasses, and thus controls any risk of unintentional scratching. The pad may provide a double utility by also being used as a base for securing a part of the shield frame vis-a-vis the glasses.
According to a preferred embodiment, the lock means comprises resilient means and a pair of retainers adapted for retaining the shield in the secured position. This provides an easy snap fitting and avoids any play in the fit. The spring may may be implemented by any suitable means, e.g. by dedicated spring means, such as a strip of resilient plate.
According to a preferred embodiment, the shield guide faces are adapted to engage the spectacle frame in zones adjacent respective hinges for the temples. This provides an optimum control of the shield attitude or shield orientation. The structural details are thus gathered in the zones adjacent the hinges which provides an aesthetically accomplished solution. Manipulating the shield may also be confined to the zones adjacent the hinges where access is easy and where risk of accidentally touching and possibly staining the glasses is at a minimum.
The shield guide faces may be provided in a pair of slide blocks, which slide blocks may comprise shoes of low-friction resilient material. This provides for easy sliding of the shield and avoids scratching or damaging the spectacle frame.
The invention, in a second aspect, provides a combination of a removable shield and a pair of spectacles, said pair of spectacles comprising a pair of spectacle glasses, a spectacle frame with lateral portions, which lateral portions provide frame guide faces oriented generally perpendicular to the plane of the spectacle glass surfaces, and temples connected with said spectacle frame by hinges, said shield comprising a shield frame, shield glasses, lock means for securing said shield to said spectacle frame and shield guide faces, wherein said shield guide faces are adapted for cooperation with said frame guide faces so as to permit sliding said shield along a direction generally perpendicular to the plane of said spectacle glass surfaces and into A secured position with said shield glasses generally parallel to the plane of said spectacle glasses, wherein said spectacle guide faces and said shield guide faces are adapted to permit sliding said shield into the secured position, while preserving the mutual orientation of said shield and said spectacle glasses during a final stage of approach.
This achieves the advantages as enumerated above in the context of the shield.
According to a preferred embodiment, at least one of the pair of spectacles and the shield comprises a resilient means and the lock means comprises a pair of retainers, each one of the retainers being adapted for engaging the pair of spectacles at a zone adjacent a respective one of the hinges.
This provides an easy snap fitting and avoids any play in the fit. The spring may in this case be provided by various means, such as by including springs, by making the shield frame or parts hereof of a resilient material, by making the spectacle frame or parts hereof from a resilient material or by a combination of these means.
According to a preferred embodiment, the shield guide faces are provided in a pair of slide blocks. The provision of slide blocks to be assembled with the remaining portion of the shield frame offers the possibility of adapting the shield to different types of spectacles merely by providing different sets of dedicated slide blocks. Adaptation to different thicknesses of spectacle glasses, such as may arise in case of prescription glasses, may also be accommodated for by providing a range of different slide blocks. This facilitates logistics and widens the application range.
Further embodiments appear from the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in further detail with reference to the specific embodiments shown in the drawings. In the drawings
FIG. 1 is a plan view of a shield and a pair of spectacles in a separated arrangement just prior to being engaged,
FIG. 2 illustrates a plan view of the shield and the spectacles in a mutually secured position,
FIG. 3 is an enlarged detail from FIG. 2,
FIG. 4 shows an isometric view of a detail from a shield according to a first embodiment of the invention, and as secured onto a pair of spectacles,
FIG. 5 illustrates the detail from FIG. 4 in plan view,
FIG. 6 illustrates an isometric view of a shield according to a second embodiment secured onto a pair of spectacles,
Fig. 7 illustrates a plan view of the detail from FIG. 6,
FIG. 8 illustrates a horizontal section of parts of a shield and parts of a pair of spectacles,
FIG. 9 shows a front view of a component for the shield according to the first embodiment, and
FIG. 10 shows the component from FIG. 9 in side elevation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
All figures are schematic and not necessarily to scale and illustrate only details essential to the understanding of the invention while other details have been omitted. In all figures the same reference numerals are used to designate identical or similar items.
Reference is first made to FIG. 1 which illustrates a plan view of a shield 1 placed adjacent to, but slightly spaced in front of a pair of spectacles 2 . The spectacles comprise spectacle glasses 7 , spectacle hinges 4 , temples 5 , and a frame, which frame at the lateral portions provides guide faces 3 . The shield comprises shield glasses 9 and a shield frame. The main component of the shield frame is a shield beam 12 with extended lateral end portions. Referring to FIG. 3, these end portions of the shield beam 12 are angled at knees 13 from where they continue by respective extensions 16 which terminate in respective curved parts generally referred to as the retainers 11 .
FIG. 2 illustrates the same portions as FIG. 1, but in a situation where the shield has been fitted onto the spectacles and thus secured to the spectacles.
The spectacles 2 comprise temples 5 secured to the frame by means of spectacle hinges 4 . The spectacle hinge provides a bulged portion with an approximately cylindrical outline, as illustrated in FIG. 3 .
The shield beam 12 comprises a resilient piece of material in order that the shield as a whole appears as a resilient structure, referring also to FIG. 2 . The two rounded retainers 11 are adapted to engage the respective bulged parts provided by the hinges 4 and laterally clamp them by the resilient force of the shield beam. The retainers are adapted to match the bulged parts in order to provide a snug fit.
The knee 13 at the lateral part of the beam 12 , which knee connects the rear extension 16 with the front part of the shield, provides a salient which presents itself as a convenient touch point in manipulations of the shield. The knee is readily engaged by the user with his fingers without any fingers having to approach the shield glasses or the spectacle glasses. Thereby the shield offers the possibility of being manipulated with no risk of unintentional staining or scratching of any of the glasses.
Reference is now made to FIGS. 4 and 5 for a description of the guide faces. FIGS. 4 and 5 illustrate parts of the spectacle frame, in order to illustrate how the frame is cut and shaped from a sheet material, the spectacle frame comprising a lateral extension provided by a strip of metal with generally parallel edges, which strip is angled and provides one of the parts of the hinge. The temple similarly comprises a strip of sheet material also with generally parallel edges. The hinge proper comprises an essentially cylindrical component, and the vertical extension of the hinge is generally equivalent to the vertical extension of the strip parts of the spectacle frame and temple.
A pair of spectacles with a hinge of this shape is the subject of a c-i-p application Ser. No. 09/541,789, filed on Apr. 3, 2000, the contents of which are incorporated hereinto by reference. The invention is well suited for the spectacles illustrated in this patent application, but also applicable to other spectacles.
The rearward extension of the spectacle frame 16 together with parts of the hinge 4 provides spectacle guide faces. The spectacle guide faces more particularly comprise upper and lower edges 19 of the rearward extension together with the upper and the lower faces of the hinge. The guide faces further comprise the lateral face 20 of the rearward extension 16 together with the lateral exterior side of the hinge 4 . These guide faces, which are referenced 3 as a whole, refer also to FIGS. 1 and 2, define an axis of displacement 6 generally parallel to the edges of the rearward frame extension 16 . Respective guide faces at the respective sides of the spectacle frame define respective axes which may be mutually parallel, or which may include a mutual angle.
As illustrated in FIGS. 4 and 5, the shield, at each lateral side, comprises a shoe 14 fitted on the extension 16 . This shoe 14 provides shield guide faces 8 which are adapted for cooperating engagement with the respective spectacle guide faces in order to control shield orientation during the final stages of approach. The shoe may comprise a plastics material, e.g. polycarbonate. In the first embodiment, re. FIGS. 4 and 5, the shoe provides the retainer 11 , i.e. a part with a concave inner face adapted to match the lateral face of the hinge bulge. In other embodiments (not shown), the shoe merely has the form of a liner inside a curved end portion of the extension 16 , which curved portion end is provided by suitable shaping of an end portion of the strip of material that provides the root of the extension 16 . Generally, the shoe comprises a low-friction material in order to-facilitate mutual sliding of cooperating guide faces.
The spectacle guide faces, the shield and the shield guide faces are adapted in order that the shield guide faces may register the respective spectacle guide faces on both sides in a relieved state, whereas the shield guide faces are forced to gradually spread during the phase of sliding the shield into the snapping engagement. The spreading of the shield guide faces is permitted by the beam 12 being resilient in bending. This permits easy registry of the shield onto the spectacles, and following displacing the shield into the secured position, a positive grip with no play.
During application of the shield, the shield and the glasses are mutually approached, and the faces of the shoe guide the shield, once they have engaged the spectacle lateral parts, commencing from the spectacle frame knees. Further displacement, which takes the shield backwards until the retainer 11 snappingly engages the hinge, is generally by a parallel displacement. The guiding function of the guide faces is effective while these components approach the snapping engagement, and also once the engagement has been reached. In the snapped-in position, the resilient clamping of the retainers about the hinges provides a positive hold, which secures the parts with no play. The shield is adapted to the spectacles so that a suitable spacing between the respective glasses is preserved when the shield is in the secured position. Thus, the shield is guided in such way that the shield glasses never unintentionally engage the spectacle glasses.
With a pair of spectacles as explained in the above identified c-i-p application Ser. No. 09/541,789, the lateral, exterior hinge face actually comprises a temple extension, thus the shoe actually contacts a component integral with the temple. As this temple extension is cylindrical and as the shoe comprises a low-friction material, this does not impair the easy turning of the temple in the hinge while the shield remains engaged, snapped into secured position.
Reference is now made to FIGS. 6 and 7 for a description of a second embodiment of the shield according to the invention. The shield according to the second embodiment 22 is distinguished over the shield of the first embodiment mainly by the shoe. The shoe 17 according to the second embodiment is longer than is the case with the first embodiment in order that it provides extended guide faces. This extends the guiding engagement in order to provide a more accurate control of the shield inclination relative to the spectacle frame.
The shoe 17 according to the second embodiment is adapted for engaging the shield rearward extension 16 by way of the shoe comprising a suitable aperture which receives the extension 16 . The components comprise interlocking protrusions (not shown) adapted to provide a secure snap fitting. The shoe 17 according to the second embodiment provides the rearmost component of the shield, including the retainer. Adaptation of the shield according to the second embodiment 22 in order to achieve different spacings between the shield glasses and the spectacle glasses may be provided simply by supplying a selection of shoes 17 of different lengths. This is a practical advantage since such adaptation may be necessary, e.g. in view of the range of thicknesses by prescription spectacle glasses.
Reference is now made to FIG. 8 for a description of details concerning the fitting of the shield glasses relative to the shield beam. The beam 12 provides a rim component which engages a recess along the upper part of the edge of the respective shield glass. The shield glass 9 is also provided with a pair of through-bores. The beam 12 comprises a sheet material which has been suitably cut and shaped so as to provide near the knee a hook 15 which is threaded through a first one of the bores in the glass. Having threaded the glass onto the hook 15 , the glass is turned to bring the glass into surface contact with the beam. The beam in the area adjacent the nose region comprises a part which has been bent to provide a lug 21 adapted for engaging a second one of the bores in the glass. In assembled state the glass generally resides in surface contact with the beam with the lug 21 received in the second bore.
The head of the lug 21 is also provided with enlargements or with barbs (not shown), in order that a pad 10 comprising plastics and provided with a suitable bore may be engaged on the end of the lug 21 where it is retained by the barbs. The pad comprises a plastics material, such as polycarbonate. It secures the glass and it also provides a spacer means vis-a-vis the spectacle glass 7 in the region generally adjacent the nose bridge.
Reference is now made to FIGS. 9 and 10 for a description of the shoe 14 according to the first embodiment, FIG. 9 showing a front elevation, and FIG. 10 showing a side elevation. As illustrated in FIG. 10, the shoe 14 provides guide faces 8 in a generally U-shaped arrangement adapted to engage the upper edge, the lower edge, and the lateral face of the spectacle frame extension. The shoe 14 on the side opposite the guide faces 8 also comprises a shallow recess 23 with a knob 24 .
This recess provides a mating engagement with the rearwardmost part of the shield frame extension which is suitably rounded such as illustrated in FIG. 3 . The knob 24 is received in a bore 25 (illlustrated in FIG. 4) in order to secure the shoe.
Although specific embodiments have been described above to illustrate the invention, it is to be understood that such embodiments are exemplary only and not in any way intended to limit the invention which may be widely varied by a person skilled in the art without departing from the scope of the appended claims.
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A shield ( 2 ) for selective fitting on a pair of spectacles ( 2 ) comprises shield glasses, a shield frame and shield guide faces ( 8 ). The spectacles comprise a spectacle frame with frame guide faces ( 3, 19, 20 ), which are oriented generally perpendicular to or in an oblique direction relative to the spectacle glasses. The spectacle guide faces and the shield guide faces are adapted to permit sliding the shield into a secured position, while preserving the mutual orientation of the shield and the glasses during a final stage of approach.
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BACKGROUND OF THE INVENTION
This invention relates to highway and roadway reflectors and, more particularly, to reflectors mounted on corrugated metal barriers, roadway dividers and the like.
Roadway reflectors show motor vehicle drivers outlines of the highways or lanes in which they are driving during nighttime hours. They may be mounted in the concrete or macadam road surfaces between lanes or on the periphery thereof. They may also be mounted on metal posts on the side of the highways, on overhead signs, or on roadway barriers.
Metal or concrete roadway barriers or guardrails are vertically oriented and typically mounted immediately outwardly adjacent the highway shoulder to prevent vehicles from unintentionally leaving the highway or crossing medians in divided highways. As these barriers run generally parallel to the highway lanes, reflectors positioned on those barriers need to be positioned at right angles to the barriers to be seen by oncoming traffic.
U.S. Pat. No. 3,214,142 discloses reflector elements that may be mounted in the corrugations of metal highway barriers.
Larger reflectors that are set at 90 degree angles to concrete lane dividers are shown at U.S. Pat. Nos. 4,249,832 and 5,678,950. A more modern guard rail reflector that sits at 90 degrees to the guard rail to which it is mounted is shown at U.S. Pat. No. 5,950,992. This patent discloses two embodiments, one that sits on the top of I-beam guard rail supports and a second that fits in the corrugation of the metal guardrail.
U.S. Pat. No. 4,000,882, discloses a foam type reflector that is mounted in the corrugations of a steel roadway or Armco barrier. However, except for the small end of the panel, the reflective panel on these foam rubber inserts faces the roadway rather than oncoming drivers.
These reflective panels in most cases face an oncoming motor vehicle. In the case of reflectors positioned within the corrugation of steel roadway barriers, the existing reflective members are exposed to damage or breakage by the pressure of snow being forced against the barriers by snowplows during winter. Some of the patents disclose in writing supposedly resilient or elastic members, but do not show how that feature would act in the drawing. Even though a snowplow itself may not contact the roadway barrier or the reflector mounted in a corrugation or on top of the barrier (or on the side of a concrete barrier), the pressure of snow being forced to the side of the roadway by snowplows is enough to severely bend a metal based reflector or break a plastic based reflector of current construction. Resilience in the impact, as a vehicle rubs against a barrier, is also desirable.
A need has developed for a roadway reflector that is mountable on the top or side of a road barrier that will withstand the pressures and forces of snow being packed against it by a passing motor vehicle equipped with a snow plow.
It is therefore an object of the invention, generally stated, to provide a new and improved reflector for use in connection with highway road barriers.
Another object of the present invention is the provision of a highway road barrier mountable reflector that has the ability to resiliently withstand the forces of snow packed thereon by highway vehicles with snowplows attached thereto.
SUMMARY OF THE INVENTION
An articulated guard rail reflector assembly includes an elongate base suitable for mounting within at least one of the corrugation of a metal roadside barrier and the top and side of a roadside barrier, a reflector retaining member having reflective material mounted thereon and an L-shape spring steel member selectably releaseably retained at one end on said base and at an opposing end on said reflective retaining member.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention may best be understood from the following detailed description of currently preferred embodiments thereof taken in conjunction with the accompanying drawings wherein like numerals refer to like parts, and in which:
FIG. 1 is a cross-sectional view of a highway barrier post having a corrugated steel barrier mounted thereon and including circular and trapezoidal reflectors constructed in accordance with the present invention;
FIG. 1 a is a fragmentary side view of the circular reflector shown at the top of FIG. 1 as it appears mounted on top of a barrier post (shown in cross-section);
FIG. 2 is an exploded view of the reflectors of the present invention showing the construction of the circular and trapezoidal reflectors in metal;
FIG. 3 is an exploded view of the trapezoidal and circular versions of the reflectors of the present invention shown as constructed in plastic;
FIG. 4 is a fragmentary sectional view of the base and spring steel member of the plastic reflector shown in FIG. 3 ;
FIG. 5 is a fragmentary sectional view of the base member and L-shape spring member of the metal embodiment shown in FIG. 2 ; and
FIG. 6 is a perspective view of the L-shape spring steel member of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 1 a , two embodiments of the articulated reflector of the present invention are shown at 10 and 11 , respectively. Both reflectors 10 and 11 are metal framed and reflector 10 is circular in outline and adapted to be positioned on the top of a road barrier, generally indicated at 12 , or a concrete lane divider (not shown). The trapezoidal shaped reflector, generally indicated at 11 , is ideally suited for mounting on the flat portion 13 a between the corrugations 13 b , 13 c of the metal road barrier, generally indicated at 13 . In FIGS. 1 and 1 a , the circular reflector, generally indicated at 10 , is mounted to the top of the wood road barrier 12 by a wood screw 14 that has a washer 15 positioned on top of the wood road barrier 12 . In FIG. 1 , the trapezoidal shaped reflector 11 is mounted on flat portion 13 a of the corrugated road barrier 13 by means of a through bolt 16 with washers 17 — 17 positioned at each end thereof and secured by a nut 18 .
Referring to FIGS. 1 and 1 a , the circular reflector, generally indicated at 10 , includes a sheet or galvanized metal base 20 that is secured to the top of the wood road barrier 12 by wood screw 14 . In an important aspect of the present invention, an L-shape spring steel member 21 is slidably mounted and retained at one end to the metal base member 20 and at its opposing end to the circular reflector mounting plate 22 ′. The circular reflective plate 23 mounted on mounting plate 22 may be made of reflective tape, plastic or the like. As shown most clearly in FIG. 1 a , by the dotted line representation, spring steel L-shaped member 21 may be elastically bent to a substantial degree, most likely by forces asserted on the top plate 22 and reflector 23 , and still spring back into a vertical position when the force is removed therefrom.
The trapezoidal metal reflector, generally indicated at 10 , includes the identical base 20 of the circular reflector 10 . Likewise, the identical L-shape spring steel member 21 is mounted at one end to the base 20 and at its other end to the trapezoidal reflector 24 . The trapezoidal shape reflectors 25 — 25 a may be made of reflective tape, plastic, or the like. Part of reflector 25 may be cut out, if necessary, to clear the L-shape members 57 – 60 .
Referring to FIGS. 2 and 6 , both the round metal reflector, generally shown at 10 , the trapezoidal shape reflector, generally shown at 11 share the same metal base, generally shown at 20 and the same L-shape spring steel member, generally shown at 21 that on one end thereof is mounted to the base 20 and on its opposing end is mounted to either the trapezoidal shape reflector 11 or the circular shape reflector 10 .
Referring to FIGS. 2 and 5 , the metal reflector base 20 starts out as a generally flat, generally rectangular metal stamping sheet measuring 3-¼×1-½×⅛ inch including a large slot 28 11/16×1-¾ inch extending inward and defining a pair of distal ends 29 and 30 , sized to fit under and be retained by the head of a typical guardrail bolt, and an opposing rectangular mounting end 31 including a plurality, in this embodiment, four L-shape tabs 32 , 33 , 34 , 35 approximately 3/16× 5/16 that are displaced downwardly from the outward sides of the U-shape apertures 32 a , 33 a , 34 a , 35 a formed by the displacement of the respective tabs. Centrally of each of the four L-shape tabs 32 – 35 , is a central circular aperture 36 5/16 inch in diameter that will be discussed in more detail below.
Referring to FIG. 2 , the round metal reflector, generally indicated at 10 , includes in this preferred embodiment, a rectangular bottom portion 40 1-½ inch across and a large circular top portion 41 3-¼ inches in diameter preferably made out of stamped sheet metal the same thickness as generally rectangular base member 20 with the rectangular bottom portion 40 being sized substantially similar to the rectangular mounting portion 31 of base member 20 .
In a manner identical to that on the rectangular mounting end 31 of the slotted base member 20 , the rectangular base end 40 of the circular metal reflector 22 includes a plurality, in this preferred embodiment four L-shape offsets 42 – 45 stamped into the rectangular mounting end 40 from the outsides thereof with the offset portions being attached to the circular metal reflector at the outsides of the apertures 42 a – 45 a formed by the displacement of metal during the stamping of the L-shape tabs 41 – 45 . The L-shape tabs 42 – 45 are identical to the tabs 34 , 35 shown in FIG. 5 . In the center of the four L-shape tabs 42 – 45 , is a circular aperture 46 to be discussed in more detail below. Additionally, centrally of the circular portion 41 of base 22 is a second aperture 47 preferably threaded through which a threaded screw 48 , or a rivet if desired, fixedly retains the circular reflective material 23 which, in this embodiment, includes a circular plastic lens 49 , preferably of white or yellow color, retained in a circular metal frame 50 .
Similarly to the mounting portion 31 of the base metal stamping and the mounting portion 40 of the round metal reflector 10 , the trapezoidal reflector 11 includes a generally flat base side 53 1-½ inches long, and an elongate top side 54 5 inches long with opposed converging sides 55 , 56 , defining a 2-¾ inch high reflector preferably made of ⅛ inch stamped sheet metal. As with the reflector base 31 and the round reflector base 40 , adjacent the base side 53 of trapezoidal reflector 11 is a plurality, in the preferred embodiment, four tabs stamped out of the sheet metal tabs 57 , 58 , 59 and 60 , stamped out of the sheet metal to extend rearwardly of the reflector 11 , also defining U-shape apertures 57 a , 58 a , 59 a and 60 a . These tabs are shaped and positioned identically to the metal tabs 42 , 45 in the circular reflector 10 and tabs 32 – 35 in the reflector base, and are of a depth to retain the L-shape spring steel member therein. Also, a central aperture 61 is in the same position as the central apertures 46 and 36 of the reflector base and round reflector and performs the same function.
In this embodiment, a variation of the reflector is shown as having two adhesive panels 25 and 25 a that are adhered to the front and back sides of the trapezoidal metal reflector.
Referring to FIGS. 5 and 6 , one important aspect of the present invention is the spring steel L-shape member, generally indicated at 21 in FIG. 6 . Generally L-shape member 21 is made of spring steel, starts out as a flat piece of sheet metal, approximately 1×2-½× 1/32 inch, is bent into an L-shape defining base rectangular portion 58 about 1×1- 3/16 inch, and vertical rectangular portion 59 about 1× 3/16 inch joined by a semi-cylindrical rolled portion 60 ⅛ inch in inside diameter therebetween.
The inch width of L-shape spring steel member across the flat portions parallel to the axis of the rolled portion 60 is sized to fit snugly between the vertical portions of the various opposed L-shape members such as 32 and 34 in metal base member 20 , 42 and 44 in upright round metal reflective member 22 and 58 – 60 in trapezoidal reflective member 24 i.e., the members define an opening about 1/32 inch in height. This allows the base member 58 to slide between the L-shape members 32 – 34 and 33 – 35 until such time as the tab 61 , about 9/32×⅜ inch slips into and is retained by aperture 36 in the metal base member 20 .
Likewise, the vertical tab 62 will be retained either in aperture 46 of the round metal reflector or aperture 60 of the trapezoid metal reflector when either of those reflectors is slidably mounted by its respective L-shape tabs on the vertical portion 59 of spring steel member 21 . The central rolled portion 60 provides a structure to allow the vertical portion 59 to bend arcuately from its vertical portion to an obtuse angle when sufficient force is applied to the reflective member, such as by packed snow being moved by a highway snowplow, road grader or the like. The elasticity of the spring steel member allows the movement of the reflective member as shown in FIG. 1 a in dotted line and allows that member to return to its original vertical position after the applied force has been removed therefrom.
Tabs 61 and 62 are not L-shaped similarly to the prior mentioned tabs, but are simply bent or creased at their bottom at an acute angle with the adjacent flat portion of the spring steel member.
Sliding the spring steel member along the L-shape tabs of the respective reflector mounting portion until the tab 61 or 62 enters and retains itself in the adjacent aperture 26 , 46 or 60 will selectively lock the spring steel member to the respective reflective metal member. That locking engagement may be released by depressing the tab through the aperture until it elastically is positioned generally parallel to the remainder of the adjacent portion of the L-shape member from which it is springingly deformed, as shown most clearly in FIG. 5 .
Referring to FIGS. 3 and 4 , third and fourth embodiments of the articulated reflector of the present invention are shown with the reflector base 65 , circular reflective material 66 and trapezoidal reflective material, generally indicated at 67 all made out of a tough plastic material such as polycarbonate, ABS, or the like. The outside dimensions of plastic reflector base 65 are sized substantially identical to those of metal reflective base 20 including an elongate slot 66 defining two distal end members 67 , 68 and a rectangular mounting portion 69 .
Similarly, circular reflective mounting plate 66 is sized on its outward dimensions identically to circular metal mounting plate 22 with respect to the size of the rectangular mounting portion 71 and circular reflector mounting portion 72 , central threaded aperture 73 that allows the mounting of a reflector base 74 that includes a reflective lens element 75 mounted to a backing member 76 and includes a central aperture 77 through which a threaded screw 78 , or rivet if desired retains the reflector lens 74 on the circular reflector mounting plate 66 .
Likewise, the plastic trapezoidal reflector mounting plate 67 is sized identically on its outward dimensions to metal trapezoidal reflector plate 11 and includes a flat base mounting side 80 . Trapezoidal reflector 67 includes, in this embodiment, reflective members 84 , 85 that are substantially identical to reflective members 25 , 25 a and adhere to the front and back of trapezoidal plastic reflective member 67 .
Referring to FIG. 4 , the structure by which either of the opposing flat ends 58 or 59 of the L-shaped spring steel member 21 is mounted on and retained by the reflector base 65 , and correspondingly in an identical manner to the plastic reflector mounting plate 66 and the trapezoidal reflector mounting plate 67 , includes a cutout slot 80 that extends upwardly from the bottom surface of base member 65 in a generally rectangular shape defined by a top wall 81 , side walls 82 and an opposing side wall (not shown) and an end wall 84 . Slot 80 is approximately 1×1-¼× 1/16 inch in size, with tolerances to allow the L-shape spring steel member to snugly slide therein.
While the plastic reflector base and circular and trapezoidal reflector mounting plates do not include L-shape tabs punched out of a metal plate like the metal reflector 10 , the slot 80 does include four semicircular tabs 5/16×5- 3/32× 1/32, two of which are shown at 85 and 86 in FIG. 4 that extend inwardly of each of the opposing walls of the slot to slidingly engage and embrace the lower surface of either the rectangular base portion 58 or rectangular vertical portion 59 of the L-shape spring steel member 21 . The bottom of base 20 is to fit flush against its mounting without the washers used on the metal embodiments. The flush fit aids the toughness of the tabs.
A central aperture 87 5/16 inch in diameter extend from the top wall 81 through the remainder of the plastic reflector base 65 provides an identical function as apertures 36 , 46 and 60 of the metal reflector base and reflector mounting portions, respectively, in that it receives and restrainingly retains the spring steel mounting plate tab ( 61 as shown in FIG. 4 ).
In a manner identical to that shown in FIG. 5 , the tab 61 may be bent downwardly until it is parallel to the remainder of the spring steel portion 58 when the reflector needs to be disassembled.
In the embodiment shown in FIG. 4 , apertures 88 and 89 are formed above the respective tabs 85 and 86 and are sized similarly thereto to provide for ease of molding the tabs 85 and 86 . In a manner similar to apertures 88 and 89 on one side of the plastic reflector base 65 , apertures 91 and 92 are formed on the opposing side to allow for molding their complementary tabs (not shown) to extend inwardly adjacent the bottom of the slot 80 in base portion 65 . In the preferred embodiment, tabs 85 and 86 , and the remainder of the tabs in the base mounting plate 65 circular reflector mounting plate 66 and trapezoidal reflector mounting plate 67 are semicircular in shape, although it should be noted that other shapes such as rectangular, triangular or the like may be utilized in forming tabs to retain the spring steel, L-shape member on the respective reflector base and reflector mounting members.
The circular reflective mounting member 66 includes a central aperture 95 and apertures 96 a , 96 b , 96 c and 96 d positioned spatially adjacent corresponding semicircular tabs (not shown) because the vertical portion of the L-shape spring steel mounting member 59 covers same.
In a trapezoidal plastic reflector mounting member 67 , tabs 100 and 101 are shown through apertures 10 a and 101 a respectively while the inward facing face of tabs 102 and 103 are shown through apertures 102 a and 103 a , respectively. Central aperture 104 again forms the same purpose in trapezoidal reflector mounting member as the central aperture 95 in the circular reflector mounting member.
Thus, two embodiments of a metal reflector are shown and described, and two embodiments of a plastic reflector are shown and described, disclosing features that provide the inventive aspects of the present disclosure.
All of these embodiments disclose articulated highway reflectors that will survive and continue to function after being deformed by pressure from snow, impact, or the like and will spring back to working position when that pressure or force has been released to provide for continued reflectivity, increased life of the reflector, and increased safety for travelers traveling on the roads adjacent which these reflectors are mounted.
While four embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the true spirit and scope of the present invention. It is the intent of the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.
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An articulated guard rail reflector assembly includes a standardized base adapted for mounting the corrugations of a metal guardrail or on top of a guard rail and a pair of interchangeable top reflector holding members, one being circular in outline and one being trapezoidal in outline to fit in the corrugation of a metal highway barrier. The base member and the reflective member are joined by a spring steel L-shape clip that snaps into place. The base and reflector holding members may be made of sheet or galvanized metal, aluminum, polycarbonate plastic, ABS plastic or the like. The L-shape member is made of spring steel and allows the reflector to be moved backwardly of its direction facing traffic by either brushing forces rubbing against the guardrail, or by the pressure of packed snow being pushed against the guardrail by a motor vehicle carrying a snowplow or the like. Preferred reflector material includes plastic lenses and/or reflective tape.
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CLAIM OF PRIORITY UNDER 35 U.S.C. §119
[0001] The present application for patent claims priority to Provisional Application No. 62/093,135 entitled “UNIFORM LIGHT SOURCE WITH VARIABLE BEAM DIVERGENCE” filed Dec. 17, 2014, and assigned to the Assignee hereof, the entire contents of which are hereby expressly incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to illumination devices including adjustable light sources with a mixing chamber for providing uniform illumination.
BACKGROUND
[0003] Light-emitting diodes (LEDs), particularly white LEDs, have increased in size in order to provide the total light output needed for general illumination. As LED technology has advanced, the efficacy (measured in lumens/Watt) has gradually increased, such that smaller die now produce as much light as was previously created by emission from far larger die areas. Nonetheless, the trend favoring higher light outputs has led to larger semiconductor LED die sizes, or, for convenience, arrays of smaller die in series or series-parallel arrangements. Series arrangements are generally favored because the forward voltage of LEDs varies slightly, resulting, for parallel arrangements, in an uneven distribution of forward currents and, consequently, uneven light output.
[0004] Ordinary light sources commonly have a fixed light-distribution pattern that cannot be modified by the user. The beam angle of the light emanating from the light source depends on the intended application; in the retail marketplace, for example, “spotlights” refer to narrow-beam sources while “floodlights” illuminate over a wide area. While the technology for varying beam angle is well known, the resulting systems tend to be too costly or inefficient for consumer use. Movable refractive optics, for example, can be used to alter beam angle as the position of a lens is varied. But the acceptance angle of such optical systems varies with position, so the efficiency decreases as the beam angle is altered. Moreover, because multiple optical surfaces are required, light losses can quickly mount as additional optical elements are added. Preventing color separation, distortion and other artifacts may require still further optical features.
[0005] Yet the ability to vary beam angle may be desired in various applications where expensive optical systems would not be cost-justified. A merchant, for example, may wish to vary the output of the same display light source to illuminate an array of objects or a single, small object. A need, therefore, exists for cost-effective light sources that produce variable beam angles with uniform illumination and without sacrificing beam quality.
SUMMARY
[0006] One aspect of the present disclosure provides a light source producing a beam of variable divergence. The light source may comprise one or more light-emitting devices arranged on a planar substrate, with each of the light-emitting devices having a Lambertian emission distribution. The light source may further comprise a chamber for mixing light emitted from the one or more light-emitting devices, the chamber itself comprising a base defined by the planar substrate, one or more side walls having a reflective interior surface, and a planar diffusive emission surface defining a ceiling of the chamber. The chamber may have an adjustable height. Further, the light source may comprise a reflector extending from the chamber for redirecting light exiting from the chamber to form a light beam, the reflector surrounding and having a focal plane coincident with the ceiling of the chamber. Finally, the light source may comprise a mechanism to control a height of the chamber to thereby variably control a divergence of the light beam.
[0007] Another aspect of the disclosure provides a light source comprising one or more light-emitting devices arranged on a planar substrate and a chamber for mixing light emitted from the one or more light-emitting devices, the chamber comprising a base defined by the planar substrate, one or more side walls having a reflective interior surface, and a planar diffusive emission surface defining a ceiling of the chamber, wherein the base is movable in relation to the ceiling. The light source may also comprise a reflector extending from the chamber for redirecting light exiting from the chamber to form a light beam, the reflector surrounding and having a focal plane coincident with the ceiling of the chamber.
[0008] Yet another aspect of the disclosure provides an adjustable light source for producing a light beam of variable divergence. The light source may include one or more light-emitting devices arranged on a reflective substrate. The light source may further comprise a chamber for mixing light emitted from the one or more light-emitting devices, the chamber itself comprising a base defined by the reflective substrate, one or more side walls having a reflective and flexible interior surface, and a diffusive emission surface defining a ceiling of the chamber, wherein the distance between the base and the ceiling is adjustable. The adjustable light source may also comprise a reflector extending from the chamber for redirecting light exiting from the chamber to form a light beam, the reflector surrounding and having a focus coincident with the ceiling of the chamber. Finally, the adjustable light source may comprise a mechanism for adjusting the distance between the base and the ceiling, wherein adjusting the distance changes the divergence of the light beam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a Lambertian distribution of light output intensity at various angles.
[0010] FIG. 2 is a side cross-section view of a light mixing chamber containing an LED light and a coupled reflector, with a base of the light mixing chamber being shown in two alternate positions.
[0011] FIG. 2A shows side cross-section view of light mixing chambers with rigid walls in expanded and collapsed positions.
[0012] FIG. 2B shows a side cross-section view of a light mixing chamber with flexible walls in expanded and collapsed positions.
[0013] FIG. 2C shows a side cross-section view of a light mixing chamber with rounded, flexible walls in expanded and collapsed positions.
[0014] FIG. 3 is a diagram showing how a radius corresponding to an internal beam angle originating from an LED light increases as a distance from the LED to an exit screen increases.
[0015] FIG. 4A shows a front view diagram of an LED arrangement having a particular diameter upon a base of a mixing chamber,
[0016] FIG. 4B shows a side view diagram of the LED arrangement of FIG. 4A in a mixing chamber, the mixing chamber having a particular distance from the LED to the exit screen.
[0017] FIG. 5 shows a side view diagram of a light mixing chamber and particular distances of of its components.
[0018] FIG. 6 is a graph depicting how as the LED-to-exit screen distance of the mixing chamber increases, the output beam angle increases and the center beam intensity decreases.
[0019] FIG. 7A shows a side view diagram of a light mixing chamber with flexible side walls in a fully expanded position and having a frusto-conical shape.
[0020] FIG. 7B shows a side view diagram of the light mixing chamber of FIG. 5A with the base and exit screen in a closer position and the flexible walls partially collapsed.
[0021] FIG. 8A shows a side view diagram of a light mixing chamber with flexible side walls with pleats in a fully expanded position and having a rectangular shape.
[0022] FIG. 8B shows a side view diagram of the light mixing chamber of FIG. 6A with the base and exit screen in a closer position, and the flexible walls with pleats folded outward and forming the shape of a bellows.
[0023] FIG. 9 is a logical block diagram of a light source coupled to a power source, an adjustment mechanism for varying the size of the light mixing chamber, and a controller for the adjustment mechanism.
DETAILED DESCRIPTION
[0024] Embodiments of the present disclosure provide light sources that include an arrangement of LEDs and a light mixing chamber having a variable height; the height of the mixing chamber and other optical parameters collectively determine the output light distribution.
[0025] Embodiments of the disclosure exploit the fact that the light distribution of LEDs varies in intensity with the cosine of the angle measured from the central optical axis perpendicular to the plane of the LED emitter. This cosine variation, also known as a Lambertian distribution, is illustrated in the polar plot 100 of FIG. 1 for a typical LED, with the central optical axis 110 depicted in the middle.
[0026] An important feature of the distribution is that the light output of an LED decreases rapidly as the angle increases from 0° to 90° (normal to the optical axis). This dependence of intensity Ion angle can be written as,
[0000] I=l 0 cos n Φ
[0000] where Φ is the angle measured from the optical axis, n is a number indicative of the width of the light distribution (higher values indicate a narrow distribution), and l 0 is the maximum intensity at Φ=0.
[0027] In various embodiments, the present disclosure includes a light mixing chamber and a coupled reflector. With reference to the representative embodiment shown in FIG. 2 , the mixing chamber 210 may contain within its volume one or more LED light sources 220 mounted on a base or floor 225 . In the embodiment shown, one or more of the interior surfaces 215 of the mixing-chamber walls may be highly (i.e., at least 90%) reflecting; this surface may be either specularly reflecting or diffusely reflecting. Advantages of the reflective properties of the surface will be discussed later in this disclosure. In various embodiments, the mixing chamber may be cylindrical, as shown in FIG. 2 , with the base 225 , the reflective surface 215 , and exit screen 250 forming the sides of the cylinder. The view in FIG. 2 is shown from a side cross section of the cylinder, which is illustrated by the base 255 , the upper and lower portions of the reflective surface 215 , and the exit screen 250 forming a “rectangle.” It is contemplated that in some embodiments, the light source 220 could comprise a linear parabolic reflector and LED arrangement within a rectangular cubic light mixing chamber rather than a cylindrical one. In such an embodiment, the view along the optical axis would appear rectangular. The various embodiments illustrated throughout the disclosure may be thought of as either cylindrical, cubical, or polygonal.
[0028] The exit screen 250 in the embodiment shown is a transmissive material that lies in the focal plane of the reflector 230 to which it is attached. Throughout the present disclosure, the exit screen 250 may be referred to as a “diffuse screen,” a “transmissive screen,” or a “transmissive ceiling.” The distance between the LED(s) 220 and the transmissive ceiling 250 is desirably adjustable. FIG. 2 shows the base 225 and the LED 220 in two different positions: a first position 240 shows the LED 220 further away from the transmissive ceiling 250 than it is in the second position 245 . Because the exit screen 250 lies in the focal plane of the reflector 230 , the LED-to-exit distance directly determines the resulting output beam angle of the light that ultimately exits the reflector 230 . In general, and for a given reflector design, the output beam angle of the light sources will increase as the distance between the LED(s) and the exit screen increases. Therefore, the output beam angle of the light exiting the reflector 230 may be greater at the first position 240 than at the second position 245 .
[0029] As previously mentioned, the LED-to-exit distance is adjustable, which allows for the variation in the output beam angle. The adjustment can be accomplished either by moving an adjustable base closer to a fixed exit screen, moving an adjustable exit screen closer to a fixed base, or moving both an adjustable base and an adjustable exit screen closer to each other. FIG. 2A shows embodiments of a design with a rectangular (as viewed from a side cross-section) mixing chamber with rigid side walls. The first view 260 A shows the mixing chamber with a movable base at first base position 1 , and the second view 270 A shows the same chamber, but with the movable base at a second position 2 , which is closer to the exit screen than position 1 . As shown, the base moves along the inside of the rigid walls, and the exit screen and rigid walls remain in place. FIG. 2A also shows alternative embodiments of the mixing chamber on the right with a first view 280 A and a second view 290 A which have an exit screen and reflector that are fixed to each other, but which are movable in relation to a fixed base. Mixing chamber 280 A is shown in an expanded position, and mixing chamber 290 A is shown in a shortened position, with the exit screen and reflector moved closer to the fixed base. A number of physical structures may be used to accomplish the movement of the various sides within the chamber as described herein. For example, the mixing chamber may be constructed with inner and outer portions arranged like two nested paper cups, with the inner cup capable of moving back and forth within the outer cup.
[0030] FIG. 2B shows a side view cross section of a mixing chamber with flexible, rather than rigid side walls. The first view 265 B shows the chamber in a fully expanded position, and the second view 275 A shows the chamber in a shortened (i.e., collapsed) position, with the flexible side walls folding somewhat to accommodate the shorter LED-to-exit distance. The flexible side walls may be constructed in a number of ways to specifically control how the side walls collapse or fold. These embodiments will be discussed in greater detail later in the disclosure. Alternatively, the mixing chamber may have a rounded shape with a single wall, forming a half-spherical shape, as shown in cross-section in FIG. 2C . The first view 285 C shows the mixing chamber in a fully expanded position and the second view 295 C shows the same chamber in a shortened of collapsed position. The embodiments shown in FIGS. 2B and 2C may have their flexible walls constructed like a bag, with the LED arrangement at the bottom and the exit screen at the top opening of the bag. The material may have elastic properties in some embodiments in order to provide uniformity in shape as the chamber expands and collapses. The embodiments of variable-distance mixing chambers shown herein are just a few examples of possible mixing chamber configurations. Any number of shapes may be used. For example, a mixing chamber may be polygonal with multiple wall segments.
[0031] The diffusing property of the transmissive screen 250 may be uniform thereacross or may vary from center to edge. In various embodiments, the screen is a diffusing material having an angle of distribution (i.e., the angle from the optical axis at which beam intensity is half of that along the optical axis) ranging from 30° to 55°; the optimum degree of diffusion of the screen depends on the height of the mixing chamber. Materials with appropriate degrees of diffusion that could be used in embodiments of the present disclosure include, for example, glass that is highly transparent, and textured plastic, though other materials may be used. For the purposes of the present disclosure, the “height” of the mixing chamber refers to the distance between the base and the exit screen. This measurement may also be referred to as an “LED-to-exit distance.” Insufficient diffusion by the screen may cause undesirable images of the LEDs to form. For example, dark spots in between individual LEDs may become visible, or a dark circle in the middle of the light source may appear. At the same time, in an arrangement of multiple LEDs, varying the LED output intensity from the center outward can be exploited (by itself or in combination with a variable diffusing screen) to create a desired light distribution. For example, varying the LED output intensity can mimic the output of a halogen bulb. In one embodiment, LEDs at the central zone of an LED cluster may have a light output of 100 lumens or more (e.g., close to 250 lumens), while LEDs outside the center zone may have an output of only 25 lumens. The optimal size of the center zone varies with the application; in a working design, the center is about 4 mm 2 while the overall area of the focal plane is 380 mm 2 . LEDs with different outputs may be used or the arrangement may consist of the same LEDs driven at different current levels. Therefore, various properties of transmissive screen diffusiveness and LED output intensity may be combined, in addition to varying the height of the light mixing chamber, in order to create the desired light output attributes from light sources in accordance with this disclosure.
[0032] The principle of operation of varying the chamber height is illustrated in FIG. 3 . For simplicity, we consider two positions for a single LED 320 in relation to the transmissive exit screen to illustrate the effect on the internal beam angle. The beam angle discussed in FIG. 3 may be referred to as the “internal beam angle” because it refers to the angle of the beam produced by the LED within the light mixing chamber, as opposed to the angles of beams produced from the exit screen or from the end of the reflector. As previously stated, the output beam angle is the angle of light exiting the reflector. For the purposes of the present disclosure, the internal beam angle φ is chosen as a fixed angle that is measured at the angle for which the light intensity is half of the maximum light output at zero degrees.
[0033] FIG. 3 shows the transmissive exit screen which is shown at a closer position (position 1 ) and labeled 350 and a further position (position 2 ) labeled 360 . Close proximity of the LED 320 to the transmissive exit screen at position 1 350 corresponds to an image of radius h 1 produced on the exit screen given the internal beam angle φ and a separation distance labeled d 1 . A large separation distance from the LED 320 to the transmissive exit screen at position 2 360 corresponds to an image of radius h 2 (a larger radius than h 1 ) given the same internal beam angle φ and larger separation distance labeled d 2 .
[0034] Given the angle φ at which a ray travels, it can be seen that the projected light from the LED 320 occupies a narrow spot of radius h 1 , when the LED-to-exit distance is d 1 , and forms a much larger spot of radius h 2 when the distance is d 2 . Because of the cosine distribution of the light shown in FIG. 1 , the intensity decreases quickly from the center 362 to the edges 364 and 356 of the transmissive exit surface 360 ; but because the light is distributed over a greater surface area at distance d 2 than at distance d 1 , the overall surface brightness that is created by the image on the transmissive exit screen is much lower when the transmissive screen is at position 2 360 . As the LED-to-exit distance increases, the radius of the image (i.e., the “spot” of light created on the transmissive exit screen) also increases.
[0035] As previously stated, embodiments of the present disclosure provide a reflector coupled to the light mixing chamber, so various effects occur as a result of pairing a light mixing chamber with an adjustable LED-to-exit distance with different kinds of reflectors. Parabolic reflectors are one type of reflector shape commonly used with LED light sources. One property of a parabolic reflector (not shown in FIG. 3 ) is that it collimates light exiting from the exit screen. In embodiments of the present disclosure, the exit screen is located at the focus of the parabolic reflector; as a result of the location of the exit screen in relation to the parabolic reflector, the parabolic reflector only collimates the light emitted from the center point of the exit screen surface. Light outside the center point is sent at various angles away from the optical axis 310 and, therefore, a wider beam exiting the reflector is produced. The greater the LED-to-exit distance, the larger the image (i.e., spot) will be, and the less focused the image will be; as a result, more light will be off-center and not collimated, and the wider the beam exiting the reflector will be. This effect of the LED-to-exit distance (and therefore, the width of the beam) can be further enhanced by constructing the parabolic reflector in nested, concentric parabolic sections, wherein the angle of reflection is collimated (i.e., equal to zero) at the exit aperture of the reflector but which has an aiming angle that lies off the optical axis (i.e., is greater than zero) closest to the plane of focus (i.e., at the exit screen.) By using the nested, concentric parabolic sections, the degree of collimation can vary over the length of the entire reflector such that it has a large angle at the bottom (close to the transmissive exit screen) and a narrower angle at the top (at the exit aperture of the reflector). An off-axis aiming angle of approximately 25° for a parabolic reflector is found to be optimal in many applications. In many embodiments, the length of each nested parabolic section of the reflector will be less than or equal to the largest value of the radius h of the image.
[0036] Alternatively, an elliptical reflector (or series of concentric elliptical reflectors) may be used, as may other reflector shapes in a similar manner as a parabolic reflector, so long as the beam exit angle changes gradually enough from the focal plane to the top of the reflector. This gradual change in angle from the bottom of the reflector to the top would be accompanied by a loss of optical efficiency, rendering the device less useful, if it were not for the properties of the mixing chamber. Inevitably, a portion of the light from the LED striking the transmissive exit surface is reflected back into the mixing chamber. At position d 2 , however, a larger fraction of the light originating from the LED strikes the reflecting wall(s) of the mixing chamber first than the fraction that strikes when the exit surface is at d 1 . Because of the high reflectivity of the wall(s), any light that initially hits the reflective walls is reflected one or more times against the various surfaces of the mixing chamber until it eventually strikes the transmissive exit surface and leaves via the reflector. Hence, there is little loss in efficiency regardless of the position of the LED and beam angle when the interior walls of the mixing chamber are highly reflective. Computations taking account of the optical properties of the materials indicate a decrease in efficiency of only about 3% over the full range of beam angles and LED positions. Therefore, elliptical, parabolic, or other shaped reflectors may be used with a mixing chamber with highly reflective interior walls without much loss in efficiency.
[0037] It is found that optimal performance of a light source of the present disclosure, as measured by efficiency of the light source and the widest range of potential output beam angles, occurs when the LED-to-exit screen distance is no greater than five times the diameter of a single LED or the diameter of multiple LEDs in an arrangement. The term “diameter,” for the purposes of describing the dimensions of the light source, means the longest dimension of the LED arrangement, corresponding to the geometric diameter in the case of a circular pattern. FIG. 4A shows a front view of a base 425 A and an LED arrangement 420 A. As shown, the LED arrangement 420 A has a diameter d 3 . FIG. 4B shows the base and LED arrangement of FIG. 4A in a side profile view within a light mixing chamber 400 B. The LED arrangement 420 B has the same diameter d 3 , and the LED-to-exit screen distance has a distance d 4 , which is approximately five times the diameter d 3 . A ratio greater than five to one wastes light from the LED because at such a great distance, too much light initially bounces off the walls, and only a small portion initially hits the exit screen, and there is very little light available near the plane of the LED (since the intensity falls off with the cosine of the emission angle). In other words, the light that is emitted from the angles furthest from the central optical axis (e.g., the light that is emitted at angles closest to the base upon which the LED sits) has a lower intensity than the light emitted closer to the central optical axis, as illustrated in FIG. 1 . Therefore, at greater distances, a large amount of low-intensity light is reflected off of the walls of the mixing chamber. To limit adverse effects of this phenomenon, in certain embodiments of the present disclosure, the ratio of the LED-to-exit distance to the diameter of the LED light arrangement is exactly five to one. For example, in some embodiments, the diameter of an LED cluster is about 2 mm and the height of the chamber is 1 cm.
[0038] In addition, the ratio of the LED-to-exit distance to the radius of the exit screen is desirably no greater than two to one. The term “radius,” for the purpose of the present disclosure, means half the longest dimension of the exit screen, corresponding to the geometric radius in the case of a circular screen. FIG. 5 shows a light mixing chamber 500 with an exit screen 550 . The exit screen 550 has a radius of distance d 6 . The light mixing chamber 500 has an LED-to-exit screen distance d 5 , which, as shown in FIG. 5 , is approximately two times the distance d 6 . The ratio of the diameter of the LED arrangement, (shown as distance d 7 ), to the diameter of the exit screen (shown as distance d 8 ) determines the smallest achievable beam angle exiting the reflector. The larger the diameter of the LED, the larger the radius h (of the image) will be. If the diameter of the LED is too large, the radius h of the image will quickly equal the radius of the screen as the LED-to-exit distance increases, which limits how small the output beam angle can be. It is possible to make the minimum beam angle very small by altering various dimensions of the light source. For example, if the radius of the exit screen is made larger in comparison to the diameter of the LED, the output beam angle becomes smaller. The output beam angle can also be made smaller by increasing, in relation to the diameter of the LED, both the radius of the exit screen and also the size of the exit aperture of the reflector. In the limit, the minimum beam angle can be made infinitely small by making the entrance opening and the reflector infinitely large, thereby making the range achievable output angles also infinitely large.
[0039] FIG. 6 illustrates the relationships between LED-to-exit distance (“chamber position”) and (i) output beam angle and (ii) center output beam intensity based on geometric model calculations. As shown, the chamber position is plotted on the x-axis from zero to twelve mm. As the distance increases from just over 2 mm to just under 4 mm, the center beam intensity, plotted along the left y-axis and measured in candela, drops significantly from over 3500 Cd to approximately 2000 Cd. Over the same increase in chamber position, the output beam angle from the reflector, plotted on the right x-axis and measured in degrees, increases from approximately 8 degrees to approximately 12 degrees. As the chamber position increase from less than 4 m to over 6 mm, the center beam intensity continues to drop significantly, down to approximately 750 candela, and the beam angle continues to increase significantly, to approximately 20 degrees. As the chamber position is increased to 10 mm, the center beam intensity continues to drop, though not as drastically, to approximately 500 Cd, and the beam angle increases, though also not as drastically, to approximately 30 degrees.
[0040] As previously discussed, either the base or the exit screen or both of the mixing chamber can be moved to vary the LED-to-exit distance. Since it is often required to mount the LED on a rigid metallic surface to enable the removal of heat by conduction, which limits the desirability of having the base itself be flexible, an aspect of the present disclosure provides a mixing chamber with reflecting walls that are flexible. A number of different types of materials may be utilized to fabricate flexible, reflective walls, including thin papers, metals, plastics, or films. Additionally, the flexible, reflective walls may form a variety of shapes, which themselves may further vary in shape depending on the relative positions of the LED base and the exit screen. A first representative implementation is shown in FIGS. 7A and 7B . In FIG. 7A , a mixing chamber 700 A comprising a rigid base 725 A, a transmissive exit screen 750 A, and flexible walls 715 A is shown in a fully expanded position. In this implementation, the mixing-chamber walls 715 A is flexible and wider where it meets the base 725 A than where it attaches to the exit screen 750 A; this frusto-conical configuration permits ready mechanical collapse and expansion of the mixing chamber 700 A. FIG. 7B shows the same mixing chamber shown in FIG. 7A , but in a configuration in which the distance between the base to the exit screen ceiling is less than its maximum distance. In FIG. 7B , either the base 725 B or the exit screen 750 A may be moved in order to reduce the LED-exit screen distance, and as a result, the flexible side walls 715 B fold. In some instances, it may not be desirable for the flexible side walls to fold such that they fall inward within the mixing chamber, toward the center or toward the LED. This is because if the walls of the mixing chamber fold inward too much, they may block some light rays originating from the LED that would otherwise directly hit the exit screen without being reflected within the chamber first. An advantage of the frusto-conical shape shown in FIG. 7A is that by making the attachment point of the side walls 715 A further away from the center of the LED, the flexible side wall material remains further away from the LED when the walls are collapsed. Still, it is contemplated that the highly reflective interior surface of the side walls will mitigate any adverse effects resulting from the folding of the walls into the chamber.
[0041] In another implementation, the flexible wall may have one or more pleats that causes the flexible walls to fold outwardly from the interior of the mixing chamber and form the shape of a bellows. As shown in FIG. 8A , a mixing chamber 800 A may have a base 852 A, an exit screen 850 A, and flexible side walls 815 A which form a rectangle when the LED-to-exit distance is at its maximum point. In FIG. 8B , when either the base 852 B or the exit screen 850 B is moved to reduce the LED-to-exit distance, the pleated side walls 815 B fold outwards, forming a bellows. By implementing pleated side walls that fold outwardly, no extra material from the side wall may interfere with rays originating from the LED before they hit the exit screen. The examples shown in FIGS. 7A and 7B, and 8A and 8B are just two examples of shapes and configurations for variable-distance mixing chambers according to the present disclosure. Many other shapes are contemplated.
[0042] In order to move either the base, the exit screen, or both, any suitable arrangement for causing relative movement between the mixing chamber floor and ceiling, using mechanical or electromechanical drive mechanisms, may be employed. For example, a mechanical linkage may be operated manually or via a motor such as a piezoelectric motor that requires little input power and occupies little space. FIG. 9 shows a logical block diagram of various components that may implement aspects of the variable-distance light mixing chamber. The diagram in FIG. 9 should not be construed as a hardware diagram, though various components may be implemented by hardware, software, or a combination of both. As shown, a light source 900 in accordance with the present disclosure is operatively connected to a power source 902 to provide power to the LED 920 . The power source 902 may be connected to a mechanical or electromechanical adjustment mechanism 904 . In some embodiments, if the adjustment mechanism 904 is electromechanical, the same power source 902 may supply power to both the LED and the drive mechanism 904 . Alternatively, different power sources may be used for each.
[0043] In some embodiments, the height of the mixing chamber is controlled by a controller 910 , with circuitry 906 programmed to move one or both of the base and the exit screen to achieve a desired beam divergence and/or center beam intensity of the light source. For example, based on the chart shown in FIG. 6 , a programmable controller 910 can store, in a memory 908 , the quantitative relationship between beam divergence and chamber height as a smooth curve. The controller 910 may also comprise a user interface 909 and respond to a user-supplied beam divergence value by adjusting the chamber height to produce the target beam divergence value in accordance with the curve. The same approach can be used for center beam intensity.
[0044] The terms and expressions employed herein are used as terms and expressions 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. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive.
[0045] Each of the various elements disclosed herein may be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled.
[0046] As but one example, it should be understood that all action may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, by way of example only, the disclosure of a reflector should be understood to encompass disclosure of the act of reflecting—whether explicitly discussed or not—and, conversely, were there only disclosure of the act of reflecting, such a disclosure should be understood to encompass disclosure of a “reflector mechanism”. Such changes and alternative terms are to be understood to be explicitly included in the description.
[0047] The previous description of the disclosed embodiments and examples is provided to enable any person skilled in the art to make or use the present invention as defined by the claims. Thus, the present invention is not intended to be limited to the examples disclosed herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention as claimed.
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A light source producing a beam of variable divergence, comprising one or more light-emitting devices arranged on a planar substrate, with each of the light-emitting devices having a Lambertian emission distribution. The light source may further comprise a chamber for mixing light emitted from the one or more light-emitting devices, the chamber itself comprising a base defined by the planar substrate, one or more side walls having a reflective interior surface, and a planar diffusive emission surface defining a ceiling of the chamber. The chamber may have an adjustable height. A reflector extends from the chamber for redirecting light exiting from the chamber to form a light beam, the reflector surrounding and having a focal plane coincident with the ceiling of the chamber. Finally, the light source may comprise a mechanism to control a height of the chamber to thereby variably control a divergence of the light beam.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method for operating a hearing aid, said hearing aid comprising a hearing aid component that can be worn in a human auditory canal and a balloon, the size of which can be changed and which at least partially encloses the hearing aid component. The present invention further relates to a corresponding hearing aid.
Hearing aids are portable hearing devices that provide support for people who are hard of hearing. In order to accommodate the numerous individual needs, various design formats of hearing aids are available, such as behind-the-ear (BTE) hearing aids, hearing aids with an external receiver (RIC: receiver in the canal) and in-the-ear hearing aids (ITE), e.g. including concha hearing aids or complete-in-the-canal hearing aids (ITE, CIC). The hearing aids cited by way of example are worn on the outer ear or in the auditory canal. Bone conduction hearing aids, implantable or vibrotactile hearing aids are also available. The stimulation of the damaged hearing is either mechanical or electrical in this case.
Hearing aids generally comprise an input converter, an amplifier and an output converter as main components. The input converter is usually a sound receiving unit, e.g. a microphone, and/or an electromagnetic receiving unit, e.g. an induction coil. The output converter is normally embodied as an electroacoustic converter, e.g. miniature loudspeaker, or as an electromagnetic converter, e.g. bone conduction headphone. The amplifier is usually integrated in a signal processing unit. This basic structure is illustrated in FIG. 1 with reference to the example of a behind-the-ear hearing aid. One or more microphones 2 for receiving the sound from the environment are incorporated in a hearing aid housing 1 that is worn behind the ear. A signal processing unit 3 , which is likewise integrated in the hearing aid housing 1 , processes and amplifies the microphone signals. The output signal of the signal processing unit 3 is transferred to a loudspeaker or receiver 4 , which outputs an acoustic signal. The sound is optionally transferred to the eardrum of the instrument wearer via a sound tube that is fixed in the auditory canal by means of a molded earpiece. The energy supply of the hearing aid and in particular that of the signal processing unit 3 is provided by means of a battery 5 that is likewise integrated in the hearing aid housing 1 .
The ventilation of the auditory canal when a hearing aid is worn is usually an important objective when adapting a hearing aid. A so-called ‘vent’ should therefore ensure that an exchange of air still occurs in the auditory canal if a hearing aid or a hearing aid component is positioned in the auditory canal. If e.g. an ITE hearing aid or an earpiece of an RIC device is positioned in the auditory canal, care is usually taken to ensure that a so-called open supply is achieved by means of a vent during normal operation, in order thereby to avoid any occlusion effects.
In most hearing situations, however, an open vent (i.e. a pressure-equalization facility or air-exchange facility) is primarily desirable when the hearing aid wearer is speaking. A closed vent is advantageous in environments where interference noise is present, since the interference noise cannot then reach the eardrum directly. In this case, only interference noise that has been reduced by means of e.g. bidirectional processing reaches the eardrum from the hearing aid.
It is also advantageous to close the vent in the case of so-called audio reception applications. For example, this relates to hearing situations in which the hearing aid wearer uses a telephone or receives music signals for the hearing aid via an electromagnetic connection. Direct low-frequency sound is then lost, however.
Hearing aid acousticians customarily select a specific vent for the hearing aid wearer during an initial adaptation of the hearing aid. This vent is typically a compromise between the sound quality of in particular the speech of the wearer on the one hand, and the comprehensibility of speech in interference noise on the other hand.
The publication U.S. Pat. No. 7,227,968 B2 discloses an expansible receiver module. This can be positioned in the auditory canal and has a receiver that is capable of receiving time-dependent electrical signals and outputting corresponding output signals. An expansible element encloses the receiver housing, but has an opening such that the sound generated by the receiver can reach the eardrum.
In addition, the publication U.S. Pat. No. 7,425,196 B2 describes a balloon-encapsulated receiver for wearing in the auditory canal. Here likewise, the receiver has a receiver housing that is at least partially enclosed by an expansible arrangement. The expansible arrangement is used to suppress vibration feedback and to ensure that the hearing device can be worn comfortably.
Furthermore, the publication US 2009/0028356 A1 discloses a method by means of which an inflatable balloon can be pumped up by means of low-frequency sound. This allows e.g. acoustic devices to be adapted comfortably to an auditory canal.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to achieve improved sound quality during the operation of the hearing aid, in particular while the hearing aid is being worn.
According to the invention, this object is achieved by a method for operating a hearing aid, said hearing aid comprising a hearing aid component that can be worn in a human auditory canal and a balloon, the size of which can be changed and which at least partially encloses the hearing aid component, wherein
a value specific to the current hearing situation is detected by the hearing aid during the operation thereof, and the size of the balloon is set according to the value that has been determined.
According to the invention, provision is further made for a hearing aid comprising
a hearing aid component that can be worn in a human auditory canal and a balloon, the size of which can be changed and which at least partially encloses the hearing aid component, and comprising a detection device for detecting a value specific to the current hearing situation during the operation of the hearing aid and a pump device by means of which the size of the balloon can be set according to the value that has been determined.
This means that the size of the balloon of the hearing aid and hence the size of the vent is advantageously continuously adapted to the current hearing situation. A previously unused parameter is therefore used to control the operation of the hearing aid.
In a particular application, the specific value that is detected for the current hearing situation by the hearing aid during the operation thereof relates to the presence of the voice of the wearer of the hearing aid. In particular, the balloon is made smaller when the wearer of the hearing aid is speaking. In this way, the vent between hearing aid or hearing aid component and auditory canal wall is enlarged when the voice of the actual hearing aid wearer is identified, thereby avoiding occlusion effects, in particular the increased perception of the voice signals via bone conduction.
However, the specific value can also relate exclusively or additionally to an interference noise, such that the size of the balloon is changed according to the quality or the quantity of the interference noise. It is thus possible e.g. to prevent exterior interference noise from arriving unimpeded at the eardrum.
The specific value can be determined by a classifier. For example, the specific value provides classification information which can be used to adjust the size of the balloon as appropriate.
Alternatively, the specific value can also be determined by means of a signal-to-noise ratio measurement. In this way, the size of the balloon can advantageously be continuously set as a function of the signal-to-noise ratio, for example.
However, the specific value can also be supplied by an audio receiving unit of the hearing aid. It then relates to e.g. the information that an inductively transferred telephone signal or a music signal is present.
Furthermore, the specific value can also be supplied by a feedback detector of the hearing aid. In this way, the size of the balloon can be directly set with reference to the strength of feedback.
In a particular embodiment, the hearing aid automatically learns at what time or at what specific value the balloon is made smaller, before a feedback effect occurs above a predetermined threshold. It is thereby possible to prevent feedback whistles from occurring in recurring situations.
The present invention is now explained in greater detail with reference to the appended drawings, in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows the fundamental structure of a hearing aid according to the prior art;
FIG. 2 shows a receiver in the auditory canal with an inflatable balloon; and
FIG. 3 shows an RIC hearing aid according to the present invention.
DESCRIPTION OF THE INVENTION
FIG. 2 illustrates an auditory canal 10 in which a so-called ‘external receiver’ 11 is positioned. This external receiver 11 is part of an RIC hearing aid as per FIG. 3 . It consists essentially of the actual receiver 12 and a balloon 13 which encloses the receiver 12 . The illustration in FIG. 2 is purely schematic in this case.
The receiver 12 is triggered by means of electrical signals via a line 14 . The line here leads to the actual hearing aid 15 (cf. FIG. 3 ), for example, though this is not illustrated in FIG. 2 .
The balloon 13 encloses the receiver 12 completely here. However, this is not obligatory. The essential aspect is that the balloon 13 can close at least part of the auditory canal around/at the receiver 12 or around a sound tube, such that less sound or no more sound can reach the eardrum 16 from the exterior. The balloon 13 is inflated by a pump device (not shown in FIG. 2 ). This pump device 20 can be arranged in the hearing aid 15 , i.e. outside the auditory canal 10 , or at the receiver 12 . In the first case, the line 14 or a tube running parallel therewith must accordingly also carry air from the hearing aid that is worn in the auditory canal 10 or behind the ear to the balloon 13 . In the second case, it must be possible to trigger the pump device accordingly. The pump device can be developed using the loudspeaker and corresponding valves, for example, wherein the balloon can be inflated in this case by means of low-frequency sound as per the publication US 2009/0028356 A1.
The structure of a BTE hearing aid 15 as per the present invention is schematically illustrated in FIG. 3 as mentioned above. The hearing aid 15 has a microphone 17 whose signal is supplied to a classifier 18 . The classifier transfers a corresponding classification result to a further signal processing unit 19 . This is used to e.g. filter, amplify, etc. the microphone signal and to trigger the external receiver 11 . The signal line 14 is provided for this purpose.
In addition, the hearing aid 15 here has a pump device 20 by means of which the balloon 13 of the external receiver 11 can be inflated. The pump device 20 can also be triggered directly by the classifier 18 (broken line in FIG. 3 ). The air that is required for the balloon 13 can be transported by the pump device 20 through a tube 21 that runs parallel with the line 14 to the balloon 13 . Alternatively, as suggested above, the pump device 20 can also be realized as a simple triggering device. In other words, the actual pump is located in the external receiver 11 , for example, and is merely triggered by the pump control device 20 . In this case, the hearing aid features a corresponding electrical conductor instead of the air tube 21 .
As mentioned above, hearing aids already exist which inflate in the auditory canal when active and amplify the sound. A closed adaptation is therefore possible in the inflated state, and an open adaptation is possible in the empty state.
However, the fundamental idea of the invention is to adapt the size of the vent according to the situation during use. The larger the required size of the vent, the less the balloon must be inflated. However, in order to allow an adaptation according to the situation, it is necessary for the hearing aid to detect the current hearing situation. If the hearing aid or the classifier 18 identifies an interference noise in the current hearing situation, the size of the vent is reduced by inflating the balloon 13 . The registration of an interference noise situation can be done by means of the classifier, or alternatively also by means of a simple SNR (signal-to-noise ratio) measurement. A classifier is no longer required as a detection device in the latter case, as an SNR measuring device is then sufficient.
Hearing situations can be divided into various classes. For example, the following classes of noises are distinguished: driving noise in a motor vehicle, quiet, voice, voice in interference noise, interference noise and music. The size of the balloon can be controlled as a function of these classes, wherein intermediate sizes between completely empty and completely inflated can also be achieved. The classifier (or the detection device generally) then produces a value (e.g. a classification result) that is specific to the hearing situation as a function of the class that has been detected. However, this specific value can also be the result of an SNR measurement.
In a particular embodiment, the detection device can also recognize a mixture of noises and supply a plurality of specific values for the hearing situation accordingly. An appropriate triggering value for the balloon must then be generated from this plurality of values. This can be achieved by weighting the detection values or classification values in a particular way, for example. If the hearing aid has a classifier and an SNR measuring device, for example, and the classifier detects ‘voice of wearer’ while the SNR measuring device detects interference noise in the current hearing situation, the situation ‘voice of wearer’ is considered to take precedence and the vent is opened, even if it would otherwise be closed in the case of interference noise. In this way, different classification results that occur simultaneously can be hierarchically categorized.
A further application scenario for the automatic control of the vent or the balloon 13 is the receipt of an audio signal. For example, if the classifier 18 identifies the receipt of a wireless audio signal (the hearing aid wearer is making a telephone call or wants to listen to music, for example), it is normally advantageous for the vent to be as small as possible or closed. The balloon can therefore be set to the appropriate size automatically as a function of the received audio signal in this case.
In the ‘voice of wearer’ case, particularly in a quiet environment situation, the hearing aid will increase the size of the vent adaptively, i.e. reduce the size of the balloon.
In a further exemplary embodiment, the feedback can be controlled automatically by means of the vent. If a feedback situation is specifically detected by a feedback detector, the vent size can be reduced automatically, for example, in order ultimately to reduce the feedback. This automatic feedback control using the balloon 13 , like any other control function of the balloon 13 , can be learned automatically. For example, if the same hearing situation actually occurs every day at the same time, and in this case a feedback whistle is always produced in this situation, the size of the vent can already be changed in advance before this situation occurs.
According to the invention, the balloon is therefore not always inflated when the hearing aid is worn, but only when a closed adaptation or a closed vent is necessary, e.g. in the case of audio reception or interference noise. On the basis of the current hearing situation that has been detected, a specific acoustic signal which inflates the balloon can be activated or deactivated at the receiver.
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A hearing aid and a method for operating a hearing aid to improve the quality of the hearing aid, in particular depending on the situation, include a hearing aid component that can be worn in a human auditory canal and a balloon, the size of which can be changed and which at least partially encloses the hearing aid component. During the operation of the hearing aid, a value specific to the current hearing situation is detected by the hearing aid. The size of the balloon is then set according to the determined value.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a process for applying marks at predetermined increments to a continuously moving line.
In certain applications, it is desirable to measure the length of a line by optically detecting the presence of marks applied to the line at predetermined increments. For example, U.S. patent application Ser. No. 956,065, filed on Oct. 22, 1992 discloses an optical fishing line meter for measuring the length of a fishing line. A optical sensor detects dye marks on the fishing line as the fishing line passes by the optical sensor and either increments or decrements a counter.
Processes for applying dye or other coloring to a man-made line or filament are well known to those skilled in the art. The most common method used is to force a disperse dye through a package containing the line to color the line. This process is used primarily for coloring the line along its entire length. However, there is no known method for applying dye to a line at predetermined increments.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention provides a method and apparatus for applying dye marks to a line at predetermined fixed increments. According to the present invention, an unmarked line is wound around a roller tube which has a slot formed therein communicating with the interior of the roller tube. A disperse dye is heated and vaporized. The vaporized dye is supplied to the interior of the roller tube and exits through the slot in the roller tube. The dye penetrates the portion of the line overlying the slot to produce a dye mark on the line at a predetermined increment equal to the circumference of the roller tube.
The present invention can be used in a continuously running process to mark an advancing line. In a continuously running process, the roller tube rotates such that the tangential speed of the roller tube exactly matches the speed of the advancing line. The advancing line winds onto the roller tube at one end and winds off of the roller tube at the opposite end. The process may be implemented either as a stand alone process, or may be combined with other treatment processes.
Accordingly, it is an object of the present invention to provide a line marking system and method for marking a line at predetermined fixed increments.
Another object of the present invention is to provide a line marking system for applying marks to a line where the line is continuously advancing.
Another object of the present invention is to provide a line marking system and method which is relatively simple in construction and has only a small number of moving components.
Yet another object of the present invention is to provide a line marking system and method for marking a line at predetermined increments which is capable at operating at relatively high speeds without diminishing the accuracy of the markings.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating the line marking system of the present invention.
FIG. 2 is a partial section view illustrating the construction of the marking roller used in connection with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the line marking system of the present invention is shown therein and indicated generally by the numeral 10. The line marking system 10 includes a marking roller 12 around which the line is wound, a line feed system 14 for feeding the unmarked line towards the marking roller 12, a line take-up means 16 for taking-up the marked line, drive means 18 for driving the marking roller 12, and a supply means 20 for supplying a disperse dye to the marking roller 12.
The line marking system 10 of the present invention is used to apply marks to a line at predetermined increments. In particular, the present invention is designed for use with man-made thermoplastic yarns such as nylon, acrylic, polyester and acetate yarns. The unmarked line is first wound onto the marking roller 12. A disperse dye is vaporized and supplied to the interior of the marking roller 12. The heated and vaporized dye passes through one or more openings in the marking roller 12 and impregnates the line. The location of the openings and the circumference of the roller 12 determine the increments between the marks.
Referring now to FIG. 2, the marking roller 12 is shown in more detail. The marking roller 12 comprises a generally cylindrical roller tube 22 made from thin-walled metal tubing. The interior of the roller 12 defines a dye chamber 24 which contains the vaporized disperse dye. A slot 26 is formed in the wall of the roller tube 22 which communicates with the dye chamber 24 in the roller tube 12. The slot 26 extends parallel to the axis of the roller tube and terminates short of the ends of the roller tube 22. The disclosed embodiment shows a single slot 26, however, it should be understood that any number of slots 26 can be used limited only by the size of the tube. The roller tube 22 is rotatably mounted on sealed bearings 28 which are journalled around a pipe fitting 30. The outer surface of the roller tube 22 may include a continuous, helical groove 32 to assure proper tracking of the line as it moves across the roller tube 22.
The drive means 18 is provided for rotating the marking roller 12. In the embodiment shown, the drive means 18 comprises a kiss roller 34 which contacts the line wound on the marking roller 12. The kiss roller 34 is mounted on a roller shaft 36 which is driven by a motor (not shown). The surface of the kiss roller 34 is covered with a material having a relatively high coefficient of friction to assure efficient transfer of torque to the marking roller 12 without slipping.
The supply means 20 supplies a disperse dye to the interior 24 of the marking roller 12. The supply means 20 includes a supply tank 56 where a disperse dye is introduced. Conduits 58 and 60 extend from the supply tank 56 through respective pipe fittings 30 and communicate with the dye chamber 24 in the marking roller 12. A heating means 62 heats the dye within the supply tank 56 causing the dye to vaporize. The pressure of the vaporized dye causes the dye to flow through conduits 58 and 60 to the interior of the marking roller 12. The vaporized dye passes through the slot 26 in the marking roller 12 and impregnates the portion of the line which overlies the slot.
For illustrative purposes, the unmarked line is shown initially wound onto a supply spool 40. The supply spool 40, however, is not an essential part of the invention. Instead, the marking roller 12 could be disposed in line with other treatment processes for example, the marking roller 12 could be preceded by a drawing apparatus. The spool 40 is mounted on a winder (not shown) which unwinds the line from the spool 40. A tension device 42 regulates the speed of the winder and insures constant tension on the unmarked line. A guide means, such as a guide wire 44, is provided to insure that the line does not get fouled as it is being wound around the marking roller 12.
The line take-up system 16 includes a take-up spool 48 for taking up the marked line. As with the supply spool 40, the take-up spool is not an essential part of the invention. The marked line winding off the marking roller 12 could be subjected to a subsequent treatment process. The take-up spool 48 is mounted on a winder (not shown), which is regulated by a tension device 50. A guide wire 52 is provided to guide the marked line as it winds off the marking roller 12.
In use, the line is wound off the supply spool 40 or advanced from a previous treatment process onto the marking roller 12. The line is wound around the marking roller a sufficient number of times to completely cover the slot 26. Preferably, the windings of the line should extend beyond both ends of the slot 26. During operation, the line is continuously advanced. The speed of the line and tangential speed of the marking roller 12 are exactly matched so that any given point on the line which overlies the slot 26 will remain in a position over the slot 26 as the line advances from one end of the marking roller 12 to the other. There should not be any slippage between the line and the marking roller, otherwise the marks will not be equally spaced. The helical grooves 32 in the marking roller 12 and the pressure applied by the kiss roller 34 should insure that slippage does not occur.
As the line advances along the marking roller 12, the vaporized dye passes from the dye chamber 24 through the slot 26 and impregnates that portion of the line overlying the slot 26. The width of the slot 26 determines the length of the marks on the line. The circumference of the marking roller 12 determines the distance between the marks.
Because of the heat being applied to vaporize the dye, the entire marking roller 12 will become hot during operation. Accordingly, it may be desirable in certain applications to preheat the line before it is wound onto the marking roller 12. If any preheating is necessary, a preheater 46 can be used to preheat the line before it is wound on the marking roller 12. Similarly, a blower 54 can be used to cool and dry the line as it winds off the marking roller.
Based on the foregoing, it is apparent that the present invention provides a simple, yet efficient method for marking a line at predetermined increments. Because the present invention applies marks to a continuously moving line, the process of the present invention is able to achieve a relatively high throughput. Further, no complicated metering or measuring devices are used which renders the present invention very economical.
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
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A method and apparatus for applying dye marks to a line at predetermined fixed increments. An unmarked line is wound around a roller tube which has a slot formed therein communicating with the interior of the roller tube. A vaporized dye is supplied to the interior of the roller tube and exists through the slot and the roller tube. The disperse dye contacts and penetrates the portion of the line overlying the slot to produce a dye mark on the line at predetermined increments equal to the circumference of the roller tube.
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DESCRIPTION
The invention has to do with a bent bridoon bit which has on both opposite ends one eyelet each for holding a bridoon ring.
From the use as well as from pertinent horse books there have been known bar bits and divided bits, among the latter especially the widely known so-called water bits. On the one hand, a bit must lie in the mouth without causing pain to the horse and must transfer the movement of the reins to the tongue or the jaw of the horse as clearly as desired each time (while being gentle to the mouth). On the one hand, there are bits, such as the continuous rubber bit, which, just due to the material, are very soft for the mouth but have the disadvantage of an insufficient transfer of the command to the horse. On the other hand, there exists a curved bar which has a very sharp effect for the horse and whose sharpness gradually destroys the sensitivity of the mouth as well as the guidability of the horse.
The invention is therefore based on the problem of developing by a better adjustment to the anatomy of the mouth a bridoon by means of which the horse can be guided more sensitively and by means of which the sensitivity of the horse is maintained as long as possible.
For this purpose the bridoon as defined in the invention is designed as a bar having soft edges which is thickened in the center and at the ends and whose center part can be rigid or, however, movable. By the thickening in the center, the bit adjusts to the center cleft of the tongue and encloses the tongue partly laterally in a widened semi-circle which then ends again at both sides before the passage through the mouth cleft of the lip in a slight counter movement in form of a slight curvature of the right side and of the left side. By the special shape, a sliding of the bridoon through the mouth cleft is prevented and a slight guiding to the right or to the left is guaranteed--with simultaneous gentle treatment of the opposite lip of the horse during a predominantly one-sided pull on the reins.
The horse feels this predominantly one-sided pull on the reins immediately in its mouth and not only after the sliding through of the bit on the opposite lip. Thus it can react more sensitively. Testing with the bridoon bits as defined in the invention confirms that.
For the rigid types of the bridoon bit as defined in the invention, the possibility of a turning of the bit in connection with a stronger pull on the reins was taken into consideration in such a way that, with a slight tightening of the reins, the horse finds an especially soft bit form at the tongue on which the horse can pleasantly lean in order to guarantee the necessary connection between the mouth of the horse and the hand of the rider. With increasing leaning, i.e. with a stronger counter-pressure of the horse against the rider's hand, the more considerably curved side of the elliptical center cross section of the bit bears, in place of the broad side, more and more against the tongue because of the slight turning movement of the bit. This forces the horse to respect the restraining help of the reins by slowing down the speed and demands less force of the rider. On the one hand, the horse's mouth stays soft longer and it is thus more sensitive in its reactions to the assistance of the reins and, on the other hand, the horse can be dominated more easily by the rider in dangerous situations.
For a horse which is difficult to rein in its forward urge because its mouth is hard inside or because of temperamental faults or for other reasons, the center crosspiece, which is bent forward, is bridged as defined in a further development of the invention. Here the crosspieces can also be thickened in the center, and the center of the crosspiece can then be located expediently in the connection line of the two eyelets for the bridoon rings.
For special purposes there is recommended to design the thickened center portion of the bar as a roll which has an expediently eccentric contour and is turnable around an axis located transversely to the axes of the eyelets.
The invention allows additional especially advantageous developments which are partly the object of the sub-claims and are explained in the following by means of the embodiments of the invention illustrated in the attached drawings. In the following description, "top" means the zone adjacent to the horse's ears, "below" means the zone of the end of the mouth, "front" means the zone of the bridge of the nose and "back" means the zone of the lower jaw.
FIG. 1 shows a top view of a bit equipped with the characteristics of the invention;
FIG. 2 shows a view of the bit according to FIG. 1 from the back;
FIG. 3 shows a top view of the inserted bit of FIG. 1;
FIG. 4 shows a cross section through the center IV--IV of the bar bit, as defined in the invention, according to FIG. 1;
FIG. 5 shows a cross section, according to FIG. 4, of the bit shifted after a slight pull on the reins;
FIG. 6 shows a cross section, according to FIG. 4, of the bit shifted after a strong pull on the reins;
FIG. 7 shows a perspective top view of another embodiment of the invention;
FIG. 8 shows a view of the bit, according to FIG. 7 from the back;
FIG. 9 shows a lateral view of the bit according to FIG. 7;
FIGS. 10, 11 show a schematic illustration for the explanation of the mode of operation of the bit according to FIG. 7;
FIG. 12 shows a top view of another type example of a bit as defined in the invention;
FIG. 13 shows a front view of the bit from FIG. 12;
FIG. 14 shows a top view of the bit from FIG. 12 with a cross section of the mouth;
FIGS. 15, 16 show a schematic illustration for the explanation of the mode of operation of the bit from FIG. 12;
FIG. 17 shows a view from the back of another type example of a bit as defined in the invention;
FIG. 18 shows a top view of the bit according to FIG. 17;
FIG. 19 shows the view along a cut A-B from FIG. 17;
FIG. 20 shows a front view of a center part of a variation of the bit from FIG. 17;
FIG. 21 shows a top view of another type example of a bit, as defined in the invention, as a transition bridoon for bridle bit curbing;
FIG. 22 shows a back view onto the bit according to FIG. 21;
FIG. 23 shows a schematic illustration of the mode of operation of the bit according to FIG. 21;
FIG. 24 shows a front view of another type example of the bit as defined in the invention;
FIG. 25 shows a top view of the inserted bit from FIG. 24;
FIG. 26 shows a schematic back view onto the upper jaw with the mouth open--with the bit, according to FIG. 24, set in;
FIG. 27 shows a top view of another type example of the bit as defined in the invention;
FIG. 28 shows a back view of the bit from FIG. 27;
FIG. 29 shows the view of a cut A-B through the bit according to FIG. 20;
FIG. 30 shows a schematic illustration for the explanation of the mode of operation as well as the position of the eyelets relative to the bit plane for the bits from FIGS. 1-5.
The bit 1 illustrated in FIG. 1 has the form of a hollow or solid bar of refined steel or Argentan essentially closed on both ends. On each of its ends 2, 3, the bit is provided with an eyelet 6, 7. Through each eyelet 6, 7 there is led a bridoon ring 4, 5 which is only partly illustrated.
The bar 1 as a whole is bent forward thus in the direction of that plane which is set by the two axes extending through the two eyelets 6, 7. In detail, from each eyelet 6, 7 there extends a somewhat curved first zone 8 or second zone 9 to a center portion 10 which connects the two zones and which is curved in a direction opposite to the palate. As shown, the diameter of the first zone 8 and of the second zone 9 narrows starting from the respective eyelet 6, 7 toward the center. Compared to that, the center portion is formed into a thickening 11 (FIG. 2) which has an oval or round cross section and is stretched olive-like or plank-like.
This form of bit has no sharp edges on its periphery, it is smooth throughout and, with the reins loose, leaves enough play. By means of the center thickening 11, the bit--by the adjustment to the upper contour of the tongue-remains localized to the tongue because the thickening 11 places itself into the center groove of the tongue. Thereby the horse can be turned around very easily by means of the shifting of the bit by the horse because lateral shifting of the bit is immediately noticed by the horse because of the shifting of the thickening. With a strong pull on the reins, the back side of the thickening 11 presses on the tongue, thus it forwards the command to the horse without the bit cutting in deeply.
The bar bit illustrated in FIGS. 1-6 excels by the fact that the center part of the triple-curved bar points even without pull on the reins toward the palate 21 and is bent around the tongue 14 in such a way that the side ends of the bridoon bit must have a slight counter-curve at 8, 9 before they lead into the zone of the lips 17, 19. With a pull on the rein, for instance at the lip 17, the center part bent around the tongue 14 essentially holds the bit in the center of the mouth so that the opposite lip, lip 19, is treated more gently and thus makes sliding of the bit through the mouth cleft difficult. The illustration in FIG. 4 shows the position of the rigid bit according to FIGS. 1, 2 and 3 without pull on the reins. Here the center part of the bit, which in the cross section 22 has the shape of an ellipse, lies parallel to the front surface of the tongue.
The illustration in FIG. 6 shows the further turning of the bit--recognizable by means of the cross section 22--produced by stronger pull on the rein, said turning is brought about by the fact that the bit slides up somewhat on the bridoon rings 4, 5. The bridoon bit returns on the starting position corresponding to FIG. 4 when the pressure of the reins diminishes and the bit slides downward into the bridoon ring by gravity and also by the tension of the lips.
The bit illustrated in FIGS. 7-11 excels by the fact that between the bridoon rings 4, 5 it consists firstly of a thick and therefore soft bar 1 which is bent downward thus toward the palate of the horse and, secondly, farther above approximately between the eyelets 6, 7 of the bridoon rings 4, 5 it has a thinner crosspiece 13 which is bent even farther toward the front--thus toward the palate. The lower curve (bar 1) is strengthened in the center toward the tongue 14 (at 11) and is widened there like a plum pit. Said strengthening 11 is solid and forms the main weight of the bit. Because of the point of gravity being shifted downward, only this soft center portion 10 of the bit touches the tongue 14 in case of a lighter pull on the rein 15. The upper thinner crosspiece 13 is effective only in case of a stronger pull of the rein 15 to the tongue 14, namely last but not least by a forward shifting of the bridoon heads in the bridoon rings 4, 5 (FIG. 11) toward the front above.
One can take into consideration the different temperaments of the horses as well as the different hardness and insensitivity of the tongue by producing the bit, as defined in the invention, with different degrees of hardness or sharpness, especially with respect to the sharpness of the crosspiece 13.
Thus the bit according to FIGS. 7, 8 and 9 can be made also in such a way that it enables the horse to chose between soft leaning on the lower thick bar 1 or on the more unpleasant rein guiding at the upper sharper crosspiece 13. Since, as a rule, the horse decides in favor for the more pleasant thing, hunts can be ridden more easily and the horse can be better controlled without the necessity of putting in a sharper bit from the start. The emphasizing of the bar center 10 toward the tongue side makes it easier for the horse to react in time to a lateral pull on the reins and thus prevents the pulling through toward one side with simultaneous stress on the opposite lip.
FIG. 10 shows as a broken line the position of the bit, as defined in the invention, on the tongue 14 in the mouth of the horse without pull on the rein 15. One sees that the horse leans against the soft center 10 of the bar. When the rein 15 is pulled, one recognizes from FIG. 11 that the crosspiece 13, which is sharper toward the back, puts pressure on the tongue 14 of the horse. Thereby the horse receives an easily perceivable command.
The bit is especially suited for the temporary correction of horses, which push the reins out of the rider's hand, and is immediately understood by the horse. However, it requires a gentle hand of the rider and wise self-restriction to that which is absolutely necessary. When the upper thin bar moves farther in the direction of the palate, the contrast effect is weakened. Thus it can also be used for so-called "pullers" (horses that put too much weight into the rider's hand).
The bit as defined in the invention and shown in FIGS. 12-16 is especially suited to induce horses, whose mouths have been dulled inside--which are thus "dead" in the mouth--to play with the bit and to promote a slight desirable chewing activity. According to the invention, the bit excels by the fact that the eyelets 6, 7 are attached on short arms 23, 24 bent upward at an angle. Said arms 23, 24 are located transverse to the axis of the center bar 10 of the bit which is curved forward (FIGS. 12, 14) an upright (FIG. 13). By means of the bridoon rings 4, 5, the bit hangs on the lateral arms 23, 24 in the upper closure of the mouth cleft 21 which holds the bit elastically downward.
If the rein 15 (FIGS. 15, 16) is pulled, the bar 1, which is bent several times and lies horizontally in the mouth, makes a turn against the tongue 14--namely from the position indicated by a broken line in FIG. 15 into the position indicated in FIG. 16.
As it is also shown especially in FIGS. 12-14, there is used in the center of the bar 1 a padded ring 26 which is rotatable over a thinner axis 25 and has in its periphery a one-sided strengthening enlargement 27 and on the other side a flattening 28. Thereby an eccentric unbalance originates which is terminated smoothly at the transition zones to the center portion 10 of the bar 1. The transitions are soft and go over smoothly with respect to their form. By playing with its tongue, the horse can turn the short thickened padded ring 26 and the flat side or the curved side can alternatingly play toward the tongue if the surface of the padded ring has a suitable grip.
The embodiment of the invention shown in FIGS. 17-20 is a bit divided twice where the first zone 8 and the separate second zone 9 are flexiblby connected by a softly made center piece 29. The shortened first zone 8 is formed as an eye 31 toward the center and the shortened second zone 9 is provided with a second eye 30 toward the center. The first eye 31 and the second eye 30 extend each through an eyelet 32, 33 on the lateral ends of the center piece 29. Thereby the center piece 29 is relatively freely movable with the tongue play of the horse. Nevertheless, this bit does not pinch the tongue either on the right or on the left since the first and the second zone 8, 9 are kept apart from each other by the center piece 29, which is about 4 cm long, so that an acute angle cannot originate in the center. This type stimulates the chewing of the horse's mouth valued so highly by the rider.
The center piece 29, for which expedient forms of the cross section can be recognized from FIGS. 19 and 29, is made very soft at the back side 34 of the tongue and is possibly made softer at the narrower front side 35. Naturally, the bit can also be buckled on in order to make a rough horse controllable.
With a strong pull on the reins, the pressure acts always on the center of the tongue 14 which can be pressed together only at the lateral edges 36, 37. The pinching of the tongue nerves, that is otherwise feared so much, and the bleeding of the tongue can no longer occur with this bit as defined in the invention. This embodiment of the invention is therefore without problems for the rider and the horse alike. The soft side is therefore recommended better than the singly divided water snaffle for young horses being trained to ride or jump. The sharper front side of the center piece 35, too, has a more pleasant effect on the tongue of the horse than the singly divided bit. Therefore this type example of the bit as defined in the invention is recommended especially for horses that are ridden by riding students who, as a rule, do not yet have a hand independent of the sitting motions.
The embodiment of the invention illustrated in FIGS. 21-23 shows a bit especially intended for young horses in the first training stage which still have difficulties keeping their head still because the neck muscles are not sufficiently developed, wherefore these horses still have difficulties leaning steadily on the bit. As it is illustrated, the bar 1 is bent slightly downward (FIG. 22) and considerably more toward the palate side (FIG. 21) and has on the right end and on the left end short arms 23, 24 turned downward and on whose ends the eyelets 6, 7 are provided. As illustrated especially in FIG. 23, with only a gentle pull on the rein 15 (for example, a pull of about 1 to 2 cm.) pressure is hardly exerted on the tongue 14. This is due first to the shape and orientation of the center portion 10 of the bar 1 relative to the arms 23, 24. The curve of the bar 1, which hangs down slightly forward, first turns upward with a light pull on the rein. It is only with a stronger pull on the rein (about 3 to 4 cm.) that the bar 1 exerts pressure on the tongue. Pressure on the tongue is limited secondly, in that the center portion 10 of the bar 1 is made as a soft thickening 38 shaped like a plum pit.
This bit, too, is recommended especially for use in the training of young horses as well as in riding schools since in contrast to the rubber snaffle frequently used otherwise it keeps the mouth softer.
FIGS. 24 to 27 show a further development, as defined in the invention, of the usual water snaffle. The usual water snaffle has frequently an unpleasant effect on the horse because the ring link 39--even with a slight pull on the rein--presses too sharply on the tongue, causes unnecessary friction on the palate and, on horses with a relatively sharp edge of the jaw bone, pinches the edge of the tongue laterally between the bit and the edge of the jaw bone.
The further development as defined in the invention excels by the fact that the eye 40 is integrated smoothly on the tongue side as well as on the palate side into the following zone 41 in such a way that on both sides of the ring joint common otherwise there originates a continuous line which cannot lead to chafing, blisters or soreness--neither on the tongue nor on the palate and therefore no longer lies pointlike on the tongue when there is pull on the reins but as a whole bit lies uniformly on the tongue.
With the common prior art snaffle the horse's tongue is frequently pinched when the reins are pulled. Furthermore, the juncture of the two parts of the standard snaffle has a point that chafes the palate. These deficiencies are overcome by the snaffle illustrated in FIG. 25. However, some horses have a relatively sharp edge of the jaw bone 51 (bone edges of the lower jaw covered with skin tissue) or a wide but relatively thin tongue so that the edges of the tongue are pinched between the jaw bone 51 and the bit sides 7, 8 whereby the different tongue defects originate, such as pulling up the tongue over the bit (the edges of the jaw bone are relatively insensitive to pain), putting out the tongue downward or more frequently toward a certain side. Especially the last two defects of the tongue were not correctable up to now and can be corrected only by the bits according to FIGS. 21-23 as defined in the invention.
Furthermore, the two sides 8-9 according to FIGS. 24-26 are formed uniformly strong and bent on both sides. Thereby severe tongue defects, as described in the preceding, can be avoided at least preventively.
The further embodiment of the invention according to FIGS. 27 to 29 shows a two-part bit where the first side part 44 is connected with a second side part 45 by way of a precise spherical hinge 75. The outer contour of the hinge 75 is made so smooth that trouble on the tongue 14 is out of the question. One sees also especially from FIG. 27 that the first side part 44 as well as the second side part 45 on both sides of the hinge pin 76 are rigidly curved in the direction of the tongue whereby the formation of an acute pinching angle is prevented in case of a strong pull on the reins. Otherwise this bit--especially with respect to the inclination of the axis of the eyelets 6, 7--is made essentially similar to the first embodiment of the invention.
This form of the bit combines the advantage of a rubber bit with a very versatile usability, however, without having the disadvantageous adhesive characteristics of rubber. If the center portion 10 is made thinner, this bit can be used also as a support snaffle for the bridle-bit.
In FIG. 27, the initial position of the bit is illustrated. When the reins are pulled, the angle with the tongue narrows and widens again when the pull on the reins is lessened.
As it can be further recognized especially in FIG. 30, the rigid bridoon bit as defined in the invention excels by the fact that the axis of each eyelet 6, 7 rises--with the bit lying flat--from the back to the front toward the nose by an angle α which is about 20°. If one puts down the bit with the sides reversed, thus in a way that the right side lies toward the left and vice versa, the axis of the eyelet 6, 7 descends by the same angle α from the back to the front. Therefrom the possibility results to have the bit--after the buckling--act on a higher or lower spot of the tongue.
In the embodiments of the invention explained in the preceding, many kinds of modifications are familiar to the expert without departing thereby from the idea of the invention. Although the attached drawings are to be regarded as independent means of disclosure in the sense that characteristics of the invention can be learned from the drawn representation, the invention, on the other hand, is not restricted to the details of the embodiments.
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A bridoon bit is provided with a thickened center portion having a curved lateral axis, and with end portions outwardly thereof having an opposite curvature in order that the bit may best conform to the anatomy of a horse's mouth, avoiding pressure points and preventing the horse's mouth from becoming insensitive.
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BACKGROUND OF THE INVENTION
This invention relates to an improved omega connector for electrically coupling two electronic components. More particularly, this invention relates to an omega connector having solid copper plate end sections solder bonded to the components and an intermediate loop section formed of interwoven copper fibers for enhanced flexibility.
In a typical multicomponent electronic assembly, electrical connections are made between components arranged in side-by-side relationship using an omega connector. The omega connector is commonly formed of a copper ribbon generally in a configuration corresponding to the Greek letter Ω, that is, having coplanar, flat end sections and an intermediate loop section. The components, typically printed circuit boards or the like, are positioned in a coplanar arrangement with adjacent edges spaced apart by a gap. The connector end sections are solder bonded to terminal pads on the components so that the loop section bridges the gap to provide the electrical interconnection.
During operation, the electronic assembly is subjected to temperature fluctuations that cause shifts in the relative positions of the components. This shifting tends to expand and contract the gap between the components. One advantage of the omega connector is that the loop section flexes to accommodate variations in the width of the gap. However, repeated cycling tends to harden the metal within the loop section and produce cracks that ultimately disrupt the electrical connection. Furthermore, the relative position of the components also tends to vary along the gap, that is, in a direction parallel to the component edges. This shifting also generates fatigue stresses within the loop section, which is accentuated due to the restricted flexibility of the copper strip across the width. These stresses may produce cracks that result in failure of the connection. However, a more common problem involves creep of the solder that bonds the end sections to the component. This creep is evidenced by a dramatic pulling away of the end section from the component pad and ultimately leads to failure of the solder bond, thereby breaking the connection with the component.
SUMMARY OF THE INVENTION
This invention contemplates an improved omega connector for electrically coupling two electronic components, which connector comprises an interwoven copper fiber loop section having enhanced flexibility both in the direction across the gap and in the direction along the gap to accommodate shifts in the relative positions of the components and thereby reduce fatigue-induced cracking within the connector and creep within solder bonds thereto. In this manner, the improved omega connector in accordance with this invention increases the life of the multicomponent assembly, despite repeated thermal cycling, more than a hundred fold as compared to conventional copper strip omega connectors.
In accordance with a preferred embodiment, an omega connector of this invention comprises first and second flat, generally coplanar end sections formed of nonporous copper plate and an intermediate loop section formed of interwoven copper fibers. The copper plate sections are adapted for solder bonding to suitable pads on the components. The copper fibers extend longitudinally between the end sections and are integrally formed therewith to provide a continuous electrically conductive network therebetween, which network is composed of a multitude of low resistance, fibrous electrical paths. Also, the copper fibers carry a solder nonwettable coating. A preferred coating is a nickel cladding. Alternately, the copper fibers may carry a polymer coating, such as a silicone rubber resin, of the type conventionally used as a solder stop.
In the manufacture of a multicomponent electronic assembly, the first and second end sections of the omega connector of this invention are solder bonded to terminal pads respectively on first and second electronic components arranged in side-by-side relationship separated by a gap. A strong solder bond is readily formed between the nonporous end plate and the pad. It is a feature of this invention that the end sections are not formed of copper fibers as in the loop section, which would tend to absorb solder alloy and thus remove the alloy from the pad to inhibit formation of the desired solder bond. Further, the nonwettable coating on the copper fibers of the loop section avoids wicking of the solder alloy into the loop section, which would also interfere with formation of the desired bond.
This invention further contemplates the product multicomponent assembly comprising at least two electronic components electrically coupled by the copper fiber omega connector. The connector end sections are solder bonded to terminal pads of the respective components, with the connector loop section bridging the gap between the components to provide the desired electrical communication across the gap. The discrete nature of the copper fibers within the loop section enhances flexibility of the connector to accommodate shifting in the relative position of the components during thermal cycling of the type experienced by the assembly during use. In this manner, the useful life of the assembly is dramatically increased, particularly in comparison to previous copper strip connectors.
This invention also includes a method for manufacturing the omega connector. In a preferred embodiment, the omega connector is formed from a singular, continuous strip of interwoven nickel-plated copper fibers. The strip comprises first and second portions spaced apart by an intermediate portion. Each end portion is cold welded, for example by localized application of ultrasonic energy, to bond the copper fibers there into a nonporous copper plate and thereby form the end section of the connector. The intermediate portion is shaped into a self-sustaining loop for the intermediate section of the connector. In an alternate embodiment, an omega connector in accordance with this invention is formed from a strip of uncoated copper fibers. After welding the end portions to form the end sections and shaping the intermediate portion to form the loop section, a microdroplet of suitable curable polymer precursor liquid is dispensed onto the loop section and is spread by capillary forces to coat the copper fibers. The precursor is then cured to produce a solder nonwettable coating on the copper fibers. In any event, the copper fiber omega connector is conveniently formed from interwoven copper fiber strip that is readily commercially available and using welding and forming steps that are conducive to mass production.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further illustrated with reference to the following figures:
FIG. 1 is a perspective view showing a multicomponent electronic assembly comprising electronic components electrically coupled by a copper fiber omega connector of this invention; and
FIG. 2 is a top elevational view of the loop section of the omega connector in FIG. 1 showing the interwoven copper fiber pattern.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with a preferred embodiment of this invention, referring to the figures, there is depicted a multicomponent electronic assembly 10 that includes a first printed circuit 12 and a second printed circuit board 14 connected by a braided copper fiber omega strip 16. Boards 12 and 14 comprise major faces 18 and 20 that include terminal bond pads 22 and 24, respectively, formed of copper or other suitable solder wettable metal. Boards 12 and 14 further include edges 26 and 28 and are arranged in side-by-side relationship, as depicted in the figure, with edges 26 and 28 parallel, but spaced apart by a gap. Bond pads 22 and 24 are operatively connected to electrical features (not shown) located elsewhere on boards 12 and 14 and are interconnected by omega connector 16.
Omega connector 16 comprises first and second end sections 30 and 32 and an intermediate loop section 34. End sections 30 and 32 are formed of solid copper plates. In this embodiment, loop 34 is formed of nickel-plated copper fibers interwoven in a braid pattern as shown in FIG. 2. Omega connector 16 is manufactured from a continuous strip of braided nickel-plated copper fibers of the type that is commercially available for use in forming a shield electrode in the manufacture of coaxial cable. The connector is formed from the strip in the as-shipped, collapsed condition. A first portion of the strip is clamped between suitable jaws that are ultrasonically vibrated to cold weld the fibers into an integral plate of end section 30. Similarly, a second portion of the strip spaced apart from section 30 is ultrasonically welded to produce end section 32. Alternately, the end sections may be formed by resistance welding or any other suitable process for coalescing the several fibers into an integral plate. It is believed that the nickel from the coating becomes alloyed into the copper during welding, but produces a minor nickel content that does not significantly affect the properties of the welded plates. The portion of the strip intermediate the cold welded sections is then formed into a self-sustaining loop of section 34. Following welding and forming, the strip is severed to separate the end sections from adjacent portions of the strip and complete the omega connector.
Preferably, a series of connectors are sequentially manufactured from a continuous braided strip, in which event, adjacent portions of the strip are concurrently welded and severed to form end sections of successive connectors.
To produce electronic assembly 10, boards 12 and 14 are positioned in the desired arrangement with edges 26 and 28 spaced apart by a predetermined distance. Pads 22 and 24 are initially coated with a suitable solder paste composed of tinlead solder alloy microparticles and a flux compound dispersed in a vaporizable liquid vehicle. Connector 16 is positioned with the end sections 30 and 32 set upon paste-coated pads 22 and 24. The assembly is heated to a temperature sufficient to reflow the solder alloy at the interfaces between each end section and pad. This reflow is facilitated by the low porosity of the welded plate that prevents the liquid alloy from being absorbed into the end section. In addition, the nickel clad on the copper fiber surfaces is not wet by the liquified solder, which would otherwise result in wicking of the liquid solder into the loop section 34, thereby diminishing the solder available for bonding to the components and bonding of the fibers within the loop section into a rigid mass. Thus, solder is retained between the end sections and the corresponding pads and resolidifies upon cooling to produce the desired bonds.
The resulting assembly 10 thus comprises a first end section 30 of connector 16 bonded to pad 22 of first substrate 12 and a second end section 32 bonded to pad 24 of second substrate 14, with loop section 34 bridging the gap between components. The plurality of copper fibers that forms loop section 34 are integrally formed to the welded copper plates and extend longitudinally between end sections 30 and 32. Thus, the fibers provide an electrically conductive network for carrying current between the components.
Furthermore, because of the small diameter, the fibers within the loop section provide enhanced flexibility. Flexibility is further enhanced because the fibers are not bound together into a rigid strip, but rather form a bundle of discrete strands. When assembly 10 is subjected to thermal cycling during use, the relative positions of boards 12 and 14 tend to shift. Referring to the coordinate system indicated in FIG. 1, shifting may occur along the X axis in a direction across the gap perpendicular to component edges 26 and 28, along the Y axis in a direction parallel to edges 26 and 28 and along the Z axis normal to the plane of component faces 18 and 20. With regard to shifting in the X direction, loop section 34 flexes to accommodate increases and decreases in the distance between the end sections 30 and 32 affixed to the components. For purposes of comparison, a conventional omega connector formed of a solid copper strip also flexes to adjust to changes in the width of the gap, but such flexing is accompanied by a concentration of stress in the uppermost region of the loop that work hardens the metal and tends eventually to produce cracking that disrupts the electrical connection. However, the bundle of small diameter fibers in omega connector 16 of this invention exhibits enhanced flexibility to avoid the concentration of work hardening stress and the resulting cracking. With regard to relative movement of the components in the Y direction, the unbonded bundle of small diameter fibers readily flexes to relieve stress both within the loop section and at the solder bonds to the components, in marked contrast to the limited widthwise flexibility of a conventional solid copper ribbon connector. For purposes of comparison, multicomponent assemblies similar to assembly 10 in FIG. 1 were subjected to an accelerated fatigue test that included mechanical vibration in the Y direction comparable to shifting in the positions of the components of the type experienced during operation of an electronic assembly due to temperature fluctuations. It was found that an assembly comprising a copper fiber omega connector 16 withstood greater than 50,000 cycles without failure. In contrast, an assembly comprising a conventional copper ribbon connector failed after about 500 cycles. Thus, the omega connector 16 of this invention extended the useful life of the assembly by a factor of over 100.
Omega connector 16 also exhibits enhanced flexibility to accommodate shifts in the Z direction, although such shifts are generally not deemed to be a significant factor in reducing the useful life of the assembly.
In an alternate embodiment, an omega connector similar to connector 16 in the figures is derived from a braided strip of bare copper fibers, that is, copper fibers that do not carry a coating such as the nickel cladding in the first described embodiment. The portions of the braid were ultrasonically welded to produce the copper plates that form the end sections, whereafter the intermediate portion was formed into the desired loop shape. Thereafter, a microdroplet of an ultraviolet curable two-component silicone rubber precursor was dispensed onto the uppermost region of the loop. The liquid wet the copper fiber surfaces and spread within the loop section to produce a liquid layer which, upon exposure to ultraviolet radiation, was cured to produce a silicone rubber coating. The coating was not wet by liquid solder and was thus suitable to avoid wicking of the solder into the loop section during reflow to bond the end sections to the components. In this embodiment, the polymer coating tends to bond the fibers at points of contact within the bundle, nevertheless the increased elasticity of the silicone rubber, particularly relative to copper metal, enhances flexibility of the fiber bundle over conventional copper ribbon.
While this invention has been described in terms of certain examples thereof, it is not intended that it be limited to the above description but rather only to the extent set forth in the claims that follow.
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An improved omega connector for electrically coupling components of a multicomponent electronic assembly comprises first and second flat end sections each formed of nonporous copper plate adapted for solder bonding to components, and an intermediate loop section formed of interwoven copper fibers extending between the end sections to provide a continous electrically conductive network therebetween. The fibers in the loop section carry a solder nonwettable coating to avoid interference with bonding operations to attach the end section to the components. Preferably, the loop section is composed of nickel-clad copper fibers. The fibrous loop section exhibits enhanced flexibility to reduce stresses attributed to shifting of the components during operation and thereby extend the useful life of the assembly.
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FIELD OF THE INVENTION
[0001] The disclosed embodiments relate to a high-frequency surgical testing device for testing a neutral electrode during treatment, particularly monopolar coagulation of biological tissue by means of a high-frequency current.
BACKGROUND
[0002] High-frequency surgery has been used for many years in both human and veterinary medicine in order to coagulate and/or cut biological tissue. With the aid of suitable electrosurgical instruments, high-frequency current is conducted through the tissue to be treated, so that said tissue changes due to protein coagulation and dehydration. In the process, the tissue contracts such that the vessels become closed and bleeding is stopped. A subsequent increase in the current density brings about explosive evaporation of the tissue fluid and tearing open of the cell membranes, so that the tissue is fully parted.
[0003] Both bipolar and monopolar techniques are used for the thermal treatment of biological tissue. In the case of monopolar arrangements, the high-frequency current fed from the high-frequency generator to the electrosurgical instrument is applied to the tissue to be treated via a ‘different’ electrode, wherein the current path runs through the body of a patient to an ‘indifferent’ neutral electrode and from there back to the high-frequency generator. A high current density per unit area is provided at the ‘different’ electrode for the treatment, whereas at the ‘indifferent’ electrode, the current density per unit area is significantly less compared with the ‘different’ electrode. This can be achieved with a suitably large area configuration of the neutral electrode. This arrangement ensures that no injuries, such as burns, occur in the tissue at the interface between the tissue and the neutral electrode.
[0004] In order to perform a coagulation, a high-frequency surgical apparatus is used which comprises an high-frequency surgical device with an high-frequency generator to create a high-frequency voltage or a high-frequency alternating current, as well as switching equipment and/or control and regulating equipment for activating or deactivating, or more generally for controlling the high-frequency generator.
[0005] For the safety of the patient, provision should be made, during a procedure, for constantly checking whether the neutral electrode is operating correctly and, for example, is properly placed on the patient. Any detachment of the electrode leads to a dangerous increase in the current density at the regions which still adhere, so that the injuries mentioned above could possibly occur. In order to ensure a high degree of safety for the patient, monitoring circuits are used which, for example, test the adhesion of the neutral electrode on the patient. Neutral electrode monitoring circuits of this type in a high-frequency surgical apparatus typically determine the transition resistance and/or the current distribution between the two conductive segments of the neutral electrode. Conclusions are often drawn concerning possible heating of the electrodes from these measured values. However, these conclusions are only relevant if electrode-specific parameters, such as area, geometry and structure of the electrodes are known. Particularly problematic in this context is the evaluation of very small neutral electrodes such as those sold for use with babies and small children. These can only be operated with a reduced high-frequency current strength since otherwise the heating can reach unacceptably high values. Also problematic herein is assessing neutral electrodes for their ‘operating behavior’.
[0006] It is therefore an object of the disclosed embodiments to provide a high-frequency surgical testing device which not only enables this evaluation and assures a high level of safety both for the patient and the surgeon when using a neutral electrode and but also is as easy to use as possible.
SUMMARY
[0007] Disclosed embodiments include a high-frequency surgical testing device for testing a neutral electrode during treatment, in particular monopolar coagulation of biological tissue by means of a high-frequency current, wherein the neutral electrode comprises at least one first electrically conductive electrode segment which can be brought into contact with the tissue and has a first cable for connecting to a high-frequency generator and a second electrically conductive electrode segment which can be brought into contact with the tissue and has a second cable for connecting to the high-frequency generator and wherein the testing device comprises an encoding element with a coding characterizing the neutral electrode between the first and second electrode segments, and a measurement device which is configured so that the coding can be detected in order to identify the neutral electrode.
[0008] In the disclosed embodiments, electrode identification can be carried out with divided neutral electrodes, allowing the treatment process to be designed more readily plannable. Through identification of the neutral electrode, i.e. by identifying the type of the neutral electrode, the course of the treatment can be optimized and a high degree of safety for the patient can be assured. For example, depending on the identified neutral electrode, particular current and/or voltage values can be specifically set.
[0009] Preferably, the testing device or measurement device comprises a source for direct current or low frequency alternating current as a testing current, in order to detect the coding of the encoding element. Electrical and/or electronic decoding can be carried out without great difficulty. In the process, a property of the hydrogel used to fasten the neutral electrode to the patient is utilized. The hydrogel in question has a chemical composition such that it has very low electrical conductivity for direct currents and alternating currents of very low frequency (up to ca. 100 Hz), i.e. it has high ohmic resistance. If an encoding element is now installed on the divided neutral electrode between the two partial surfaces, said encoding element can be measured with the direct current signal or the alternating current signal of very low frequency. Since the gel has a high resistance in this condition, it is irrelevant whether the neutral electrode is placed on the patient, i.e. whether a low value parallel resistance through the tissue is present or not.
[0010] According to one disclosed embodiment, the testing device, or at least portions of the testing device, is/are arranged between the first cable and the second cable such that the test current can be conducted via the first and second cable. Since the test current—as distinct from the working current—is a direct current or a low frequency alternating current, it is possible to detect the characterizing coding without providing a special conductor for this purpose. The existing cable system therefore simultaneously serves as a cable system for the measurement device and thus for detecting the coding. An additional test line or measuring line is therefore not necessary. This means that a significant advantage with regard to compatibility results therefrom that, despite the extended functional scope of the neutral electrode identification, only the two existing neutral electrode connections are used for measuring. Thus the electrodes, the connecting cables and the plug connectors remain compatible with the components available on the market. No additional cables or electrical contacts are needed.
[0011] In another disclosed embodiment, the encoding element includes a resistor element having a resistance value which characterizes the neutral electrode, wherein the testing device is configured such that the resistance value can be detected to identify the neutral electrode. Encoding via a resistor element can be carried out easily and is also easily identified by means of the test current.
[0012] The resistor element is preferably configured as an ohmic resistor or a complex resistor with inductive behavior. The resistors used (encoding resistors) must have resistance values that are significantly smaller than the resistance of the gel at the measuring frequency. However, the values must be large enough such that no appreciable high-frequency currents can flow via the resistance between the two electrode segments. Typical values lie in the range of 1 kΩ<R K <100 kΩ. For direct current and alternating current of low frequency, the relation R Gel >R K >R P applies.
[0013] In another disclosed embodiment, the resistor element is provided as a resistor film or resistor wire integrated into the neutral electrode. It is herein possible to equip even electrodes without fixed cables which are contacted via a suitable cable to a terminal with this functionality. The resistor element is therefore installed, for example, in the divided neutral electrode between the two electrode segments.
[0014] In the case of electrodes that are equipped with suitable cables, the encoding element or the resistor element, or possibly resistor elements, can be arranged between the first cable and the second cable. The application of a resistor, for example, to the cable segments, can be very easily realized.
[0015] Decoupling the test current from the (high-frequency) working current can be undertaken, for example, by connecting in an inductor as a filter element into the measuring system.
[0016] In another disclosed embodiment, the testing device or the measurement device comprises a voltage measurement device for measuring a voltage across the encoding element or resistor element (e.g. arising from the test current). The resistance value can therefore be easily determined for the respective neutral electrode. It is also possible to measure the coding or the resistance value by means of a current measurement device for measuring the direct current or the low-frequency current. This type of indirect measurement can be carried out without difficulty.
[0017] In another disclosed embodiment of the testing device, the testing device or at least parts of the testing device are configured to be integrated in the high-frequency generator to generate a high-frequency voltage. This means that the high-frequency generator is configured such that when the neutral electrode is plugged into the generator, an identification procedure can be performed, without a separate apparatus being necessary to do so. In other words, the testing device can be integrated in a high-frequency surgical apparatus.
[0018] In another disclosed embodiment, the testing device is configured such that it controls the high-frequency generator to the relevant setting, depending on the coding detected, for example, based on the resistance value detected. This means that all the values to be set at the high-frequency generator, such as current strength, would be automatically set depending on the neutral electrode that is identified. This is particularly advantageous when neutral electrodes are used which would cause burning of the patient upon exceeding a particular current strength. Therefore, a suitable current limitation could be automatically implemented, particularly with neutral electrodes for babies and small children.
[0019] It is also possible for a control device to be assigned to the testing device, the control device (which is possibly also integrated into the testing device) being configured to control the high-frequency generator to the setting thereof depending on the detected coding or the detected resistance value. A distinct control device could also be configured programmable for this purpose and could thus take over the control or regulation of the high-frequency generator.
[0020] It is also possible to carry out the relevant settings based on the detected resistance value by hand. As soon as the surgeon receives the feedback from the system concerning the detected neutral electrode, he can make the required settings, particularly on the high-frequency generator.
[0021] A storage device is preferably assigned to the testing device, in which the encodings, for example, the resistance values of resistor elements, of different neutral electrodes, can be stored as comparison values for neutral electrode identification. Thus, details concerning the neutral electrodes used can be output in simple manner which simplifies assignment for the user and enables planning of the progress of the intervention. The surgeon can therefore make suitable settings on the high-frequency generator which are adapted to the neutral electrode used.
[0022] Information concerning the neutral electrode identified can, quite generally, be output via a display on the high-frequency generator or on the high-frequency surgical apparatus. Sounds, light signals or the like can also be used for this purpose.
[0023] Preferably, the testing device is assigned to an input unit which is configured such that a user can, for example, input the comparative values into the storage device. Any other communication with the high-frequency surgical apparatus is also possible via the input unit, for example, a keyboard. The storage device can also be configured so that encodings that are not yet stored, or the values of any resistors of neutral electrodes, are detected and stored as soon as they are detected by the measurement device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The disclosed embodiments will now be described by reference to example embodiments which will be explained in greater detail with reference to the enclosed drawings.
[0025] FIG. 1 illustrates a testing device according to a disclosed embodiment.
[0026] FIG. 2 illustrates a further representation of the embodiment of FIG. 1 .
[0027] FIG. 3 illustrates a further representation of the embodiment of FIG. 1 .
DETAILED DESCRIPTION
[0028] In the following description, the same reference signs are used for the same and similarly acting parts.
[0029] FIG. 1 illustrates one disclosed embodiment of a testing device 20 . As shown in FIG. 1 , a two-part neutral electrode 40 is connected to a high-frequency generator 30 of a high-frequency surgical apparatus 10 , said high-frequency generator 30 supplying a high-frequency current. The neutral electrode 40 has a first electrically conductive electrode segment 41 and a second electrically conductive electrode segment 42 , wherein the first electrode segment 41 is connected to the high-frequency generator 30 via a first cable 50 and the second electrode segment 42 is connected thereto via a second cable 51 . The electrode segments are arranged on a common support element 43 .
[0030] The neutral electrode 40 can be applied as an indifferent electrode, particularly in monopolar treatment methods, to a tissue section of a patient and serves finally to conduct away current over a relatively large area. The flat configuration of the electrode segments 41 , 42 ensures good current distribution, so that high current peaks do not occur at points across the transition between the tissue and the neutral electrode 40 . In this way, burns and similar injuries to the patient can be avoided.
[0031] It is advantageous if the neutral electrode 40 can be identified for use thereof. This means that essential parameters of the neutral electrode 40 are identifiable to the surgeon, so that all settings regarding current strength, etc. can be specifically matched on the high-frequency generator 30 to the particular neutral electrode 40 . The setting can be carried out by hand, for example, by the surgeon, or the testing device 20 is configured or is connected to a control device 100 such that necessary settings are carried out automatically. Identification of the neutral electrode 40 and the associated matching of setting parameters are especially important, for example, for electrodes to be used with babies and small children. With these electrodes, depending on the identification thereof, a suitable current limit can be set automatically (or by hand).
[0032] In this example embodiment, a resistor element 90 is provided for identification of the neutral electrode 40 as an encoding element between the two electrode segments 41 , 42 . The resistor element 90 has a particular resistance value as the coding which is characteristic of the corresponding neutral electrode 40 , so that the precise type of neutral electrode used can be determined. The resistor element 90 is connected between the two conductive electrode segments 41 , 42 .
[0033] In order to detect the resistance value, components of the testing device 20 are connected between the generator 30 and the neutral electrode 40 . Aside from the resistor element, the testing device 20 also comprises a direct current source as the measuring current source 71 , a voltage measurement device 70 for indirect detection of the resistance value of the resistor element 90 and an inductor (e.g., a coil as the filter element 80 ) which enables decoupling of the working current and the test current or measuring current. These components of the testing device 20 constitute a measurement device 60 and are arranged such that the measuring current can be conducted via the already existing cables for connecting the neutral electrode 40 to the high-frequency generator 30 . The testing device therefore includes the encoding element 90 and the measurement device 60 .
[0034] The measuring current can be decoupled as direct current or as low frequency alternating current from the high-frequency working current in that, for example, the coil is provided as a filter, the reactive impedance of which is greater the higher the frequency is.
[0035] The direct current is supplied from the direct current source 71 ; measurement of the resistance value takes place, for example, indirectly via the voltage measurement device 70 with subsequent resistance calculation. It is also possible to use, for example, measuring bridges for resistance determination.
[0036] The resistance can be measured using the direct current or a low frequency alternating current (measuring current) without the measuring current flowing through the body of the patient. The body of the patient is essentially only capacitively coupled to the electrode. It is not necessary to provide a special connecting cable for signal transmission. A current is thus applied which, for lack of coupling into the body of the patient, cannot be used as a working current and thus enables electrode identification without the need for a special transmission line therefor. A hydrogel 44 , 44 ′ applied to the electrodes 41 , 42 for contacting the neutral electrode 40 to the tissue 130 of the patient has a chemical composition for this purpose such that said hydrogel represents a high value resistance R Gel and R′ Gel for direct current or alternating current at low frequencies (up to ca. 100 Hz). Since the gel has a high resistance in the region of the measuring current, it is unimportant whether the neutral electrode is placed on the patient, i.e. a low value parallel resistance due to the tissue 130 is present or not. With a type of filter which is in any event present (capacitive coupling of the neutral electrode to the patient) and the use of an “unsuitable” measuring current, additional cables are not necessary for data transmission in the context of neutral electrode recognition.
[0037] As described above, a control device 100 can optionally be provided, by means of which the high-frequency generator 30 is controllable depending on the detected coding value, e.g. depending on the detected resistance value. The high-frequency generator 30 can then be set to a particular current value or a current limit is preset. This is advantageous particularly in the case of neutral electrodes for children, in order to avoid overheating.
[0038] The control device 100 can be configured integrally with at least parts of the testing device 20 and the testing device 20 and/or control device 100 can also be configured integrally with the high-frequency generator 30 . In one example embodiment, a storage device 110 (which could also be assigned directly to the testing device 20 ) is also assigned to the control device 100 . Thus a particular resistance value can be assigned as the coding for each type of neutral electrode. By means of a table (e.g., type of neutral electrode vs. associated setting parameters) stored in the storage device 110 , the high-frequency generator 30 , in particular, can be automatically adjusted in the context of an instrument (or electrode)-oriented system configuration to the circumstances at the identified neutral electrode.
[0039] Furthermore, an input unit 120 is assigned to the testing device 20 via which input device a user can communicate with the system and, for example, input information which is to be stored.
[0040] FIGS. 2 and 3 show a different representation of the arrangement shown in FIG. 1 . FIG. 2 shows the neutral electrode 40 applied on a tissue section 130 of a patient by means of hydrogel 44 , 44 ′. The two conductive electrode segments 41 , 42 are separated from one another by means of a gap. The two electrode segments 41 , 42 are connected via the encoding element, the resistor element 90 which has the resistance value that is characteristic of the neutral electrode 40 . The measuring current can be applied via the connecting cables of the electrode segments (cables) 50 , 51 for connecting the electrode segments 41 , 42 to the high-frequency generator 30 and via the measurement device 60 such that the resistance value can be detected (e.g., measured). The first electrode segment 41 and the second electrode segment 42 lie on top of the gel 44 , 44 ′ on the tissue 130 of the patient. The neutral electrode monitoring system, which is integrated, for example, in the high-frequency generator 30 or in a high-frequency surgical device of a high-frequency surgical apparatus 10 , is shown in a simplified form. The divided active contact surface (electrode segments 41 , 42 ) is made, for example, from aluminium.
[0041] FIG. 3 shows, in the form of an equivalent circuit, the connection between the individual resistors. The encoding element 90 , i.e. the resistor element with the resistance R K is connected in parallel to a patient resistance R P . The two resistors R Gel and R′ Gel of the gel layers 44 and 44 ′ under the respective electrode segments behave as if they had high resistance values, as described above.
[0042] It is therefore clear that, in order to detect a coding which is characteristic for the neutral electrode, the cables with which the neutral electrode is connected to the high-frequency generator can be used. Using a suitable measuring current, the parameters of the measuring circuit can be predetermined such that a neutral electrode identification can be carried out with the least possible effort.
[0043] It should be pointed out here that all the above described parts and in particular the details illustrated in the drawings are essential for the disclosed embodiments alone and in combination. Adaptations thereof are the common practice of persons skilled in the art.
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A high-frequency surgical testing device for testing a neutral electrode during treatment, particularly during monopolar coagulation of biological tissue using a high-frequency current. The neutral electrode includes at least one first electrically conductive electrode segment having a first cable for connecting to a high-frequency generator, and a second electrically conductive electrode segment having a second cable for connecting to a high-frequency generator, the first and second electrode segments contacting the tissue. The test device includes an encoding element having a code for describing the neutral electrode and a measurement device for capturing the code describing the neutral electrode. The test device allows an identification of the neutral electrode to ensure safety.
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This application is a continuation of application Ser. No. 343,788, filed Jan. 29, 1982 now abandoned.
CROSS-REFERENCE TO RELATED APPLICATION
Zircaloy alloy fabrication methods and resultant products which also exhibit improved high temperature, high pressure steam corrosion resistance are described in related application Ser. No. 343,787 filed on Jan. 29, 1982 now abandoned, assigned to the same assignee. This related application describes a process in which a conventional beta treatment is followed by reduced temperature alpha working and annealing to provide an alpha worked product having reduced precipitate size, as well as enhanced high temperature, high pressure steam corrosion resistance. Application Ser. No. 343,787 now abandoned is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to alpha zirconium alloy intermediate and final products, and processes for their fabrication. More particularly, this invention is especially concerned with Zircaloy alloys having a particular microstructure, and the method of producing this microstructure through the use of high energy beam heat treatments, such that the material has improved long term corrosion resistance in a high temperature steam environment.
The Zircaloy alloys were initially developed as cladding materials for nuclear components used within a high temperature pressurized water reactor environment (U.S. Pat. No. 2,772,964). A Zircaloy-2 alloy is an alloy of zirconium comprising about 1.2 to 1.7 weight percent tin, about 0.07 to 0.20 weight percent iron, about 0.05 to 0.15 weight percent chromium, and about 0.03 to 0.08 weight percent nickel. A Zircaloy-4 alloy is an alloy of zirconium comprising about 1.2 to 1.7 weight percent tin, about 0.12 to 0.18 weight percent iron, and about 0.05 to 0.15 weight percent chromium (see U.S. Pat. No. 3,148,055).
In addition variations upon these alloys have been made by varying the above listed alloying elements and/or the addition of amounts of other elements. For example, in some cases it may be desirable to add silicon to the Zircaloy-2 alloy composition as taught in U.S. Pat. No. 3,097,094. In addition oxygen is sometimes considered as an alloying element rather than an impurity, since it is a solid solution strengthener of zirconium.
Nuclear grade Zircaloy-2 or Zircaloy-4 alloys are made by repeated vacuum consumable electrode melting to produce a final ingot having a diameter typically between about 16 and 25 inches. The ingot is then conditioned to remove surface contamination, heated into the beta, alpha+beta phase or high temperature alpha phase and then worked to some intermediate sized and shaped billet. This primary ingot breakdown may be performed by forging, rolling, extruding or combinations of these methods. The intermediate billet is then beta solution treated by heating above the alpha+beta/beta transus temperature and then held in the beta phase for a specified period of time and then quenched in water. After this step it is further thermomechanically worked to a final desired shape at a temperature typically below the alpha/alpha+beta transus temperature.
For Zircaloy alloy material that is to be used as tubular cladding for fuel pellets, the intermediate billet may be beta treated by heating to approximately 1050° C. and subsequently water quenched to a temperature below the alpha+beta to alpha transus temperature. This beta treatment serves to improve the chemical homogeneity of the billet and also produces a more isotropic texture in the material.
Depending upon the size and shape of the intermediate product at this stage of fabrication, the billet may first be alpha worked by heating it to about 750° C. and then forging the hot billet to a size and shape appropriate for extrusion. Once it has attained the desired size and shape (substantially round cross-section), the billet is prepared for extrusion. This preparation includes drilling an axial hole along the center line of the billet, machining the outside diameter to desired dimensions, and applying a suitable lubricant to the surfaces of the billet. The billet diameter is then reduced by extrusion through a frustoconical die and over a mandrel at a temperature of about 700° C. or greater. The asextruded cylinder may then be optionally annealed at about 700° C. Before leaving the primary fabricator, the extruded billet may be cold worked by pilgering to further reduce its wall thickness and outside diameter. At this stage the intermediate product is known as a TREX (Tube Reduced Extrusion). The extrusion or TREX may then be sent to a tube mill for fabrication into the final product.
At the tube mill the extrusion or TREX goes through several cold pilger steps with anneals at about 675°-700° between each reduction step. After the final cold pilger step the material is given a final anneal which may be a full recrystallization anneal, partial recrystallization anneal, or stress relief anneal. The anneal may be performed at a temperature as high as 675°-700° C. Other tube forming methods such as sinking, rocking and drawing, may also completely or partially substitute for the pilgering method.
Thin-walled members of Zircaloy-2 and Zircaloy-4 alloys, such as nuclear fuel cladding, processed by the above-described conventional techniques, have a resultant structure which is essentially single phase alpha with intermetallic particles (i.e. precipitates) containing Zr, Fe, and Cr, and including Ni in the Zircaloy-2 alloy. The precipitates for the most part are randomly distributed, through the alpha phase matrix, but bands or "stringers" of precipitates are frequently observed. The larger precipitates are approximately 1 micron in diameter and the average particle size is approximately 0.3 microns (3000 angstroms) in diameter.
In addition, these members exhibit a strong anisotropy in their crystallographic texture which tends to preferentially align hydrides produced during exposure to high temperature and pressure steam in a circumferential direction in the alpha matrix and helps to provide the required creep and tensile properties in the circumferential direction.
The alpha matrix itself may be characterized by a heavily cold worked or dislocated structure, a partially recrystallized structure or a fully recrystallized structure, depending upon the type of final anneal given the material.
Where final material of a rectangular cross section is desired, the intermediate billet may be processed substantially as described above, with the exception that the reductions after the beta solution treating process are typically performed by hot, warm and/or cold rolling the material at a temperature within the alpha phase or just above the alpha to alpha plus beta transus temperature. Alpha phase hot forging may also be performed. Examples of such processing techniques are described in U.S. Pat. No. 3,645,800.
It has been reported that various properties of Zircaloy alloy components can be improved if beta treating is performed on the final size product or near final size product, in addition to the conventional beta treatment that occurs early in the processing. Examples of such reports are as follows: U.S. Pat. No. 3,865,635, U.S. Pat. No. 4,238,251 and U.S. Pat. No. 4,279,667. Included among these reports is the report that good Zircaloy-4 alloy corrosion properties in high temperature steam environments can be achieved by retention of at least a substantial portion of the precipitate distribution in two dimensional arrays, especially in the alpha phase grain boundaries of the beta treated microstructure. This configuration of precipitates is quite distinct from the substantially random array of precipitates normally observed in alpha worked (i.e. below approximately 1450° F.) Zircaloy alloy final product where the beta treatment, if any, occurred much earlier in the breakdown of the ingot as described above. The extensive alpha working of the material after the usual beta treatment serves to break up the two dimensional arrays of precipitates and distribute them in the random fashion typically observed in alpha-worked final product.
It has been found that conventionally processed, alpha worked Zircaloy alloy cladding (tubing) and channels (plate) when exposed to high temperature steam such as that found in a BWR (Boiling Water Reactor) or about 450° to 500° C., 1500 psi steam autoclave test have a propensity to form thick oxide films with white nodules of spalling corrosion product, rather than the desirable thin continuous, and adherent substantially black corrosion product needed for long term reactor operation.
Where beta treating is performed on the final product in accordance with U.S. Pat. No. 4,238,251 or U.S. Pat. No. 4,279,667, the crystallographic anisotropy of the alpha worked material so treated tends to be dimensioned and results in a higher proportion of the hydrides formed in the material during exposure to high temperature, high pressure aqueous environments being aligned substantially parallel to the radial or thickness direction of the material. Hydrides aligned in this direction can act as stress raisers and adversely affect the mechanical performance of the component.
In addition the high temperatures utilized during a beta treatment process, especially such as that described in U.S. Pat. No. 4,238,251, can create significant thermal distortion or warpage in the component. This is especially true for very thin cross-section components, such as fuel clad tubing.
Through the wall beta treating the component, before the last cold reduction step, as described in U.S. Pat. No. 3,865,635, may result in increased difficulty in meeting texture-related properties in the final product since only a limited amount of alpha working can be provided in the last reduction step.
BRIEF SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention it has been found that the high temperature steam corrosion resistance of an alpha zirconium alloy body can be significantly improved by rapidly scanning the surface of the body with a high energy beam so as to cause at least partial recrystallization or partial dissolution of at least a portion of the precipitates.
Preferably the high energy beam employed is a laser beam and the alloys treated are selected from the groups of Zircaloy-2 alloys, Zircaloy-4 alloys and zirconium-niobium alloys. These materials are preferably in a cold worked condition at the time of treatment by the high energy beam and may also be further cold worked subsequently.
In accordance with the present invention intermediate as well as final products having the microstructures resulting from the above high energy beam rapid scanning treatments are also a subject of the present invention and include, cylindrical, tubular, and rectangular cross-section material.
In accordance with a second aspect of the present invention the high temperature, high pressure steam corrosion resistance of an alpha zirconium alloy body can also be improved by beta treating a first layer of the body which is beneath and adjacent to a first surface of said body so as to produce a Widmanstatten grain structure with two dimensional linear arrays of precipitates at the platelet boundaries in this first layer, while also forming a second layer containing alpha recrystallized grains beneath the first layer. The material so treated is then cold worked in one or more steps to final size, with intermediate alpha anneals between cold working steps.
Preferably any intermediate alpha or final alpha anneals performed after high energy beam beta treatment are performed at a temperature below approximately 600° C. to minimize precipitate coarsening. It has been found that Zircaloy bodies surface beta treated in accordance with this aspect of the invention are easily cold worked. It has also been found that typically both the alpha recrystallized layer as well as the beta treated layer when processed in accordance with the present invention possess good high temperature, high pressure steam corrosion resistance.
Preferably the beta treating is performed by a rapidly scanning high energy beam such as a laser beam. In one embodiment of this aspect of the invention, the degree of cold working after beta treating may be sufficient to redistribute the two dimensional linear arrays of precipitates in a substantially random manner while retaining good high temperature, high pressure steam corrosion resistance.
Beta treated and one-step cold worked alpha zirconium bodies in accordance with this second aspect of the invention are characterized by two microstructural layers. Both layers have anisotropic crystallographic textures; however, it is believed that the outermost layer, that is, the layer that received the beta treatment, is less anisotropic than the inner layer. This difference, however, diminishes as the number of cold working steps and intermediate anneals after beta treating increases.
These and other aspects of the present invention will become more apparent upon review of the drawings in conjunction with the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show optical micrographs of micro-structures produced by laser treating Zircaloy-4 tubing in accordance with one embodiment of the present invention.
FIGS. 3A and 3B show optical micrographs of a Widmanstatten basket-weave structure produced by laser treating Zircaloy-4 tubing.
FIGS. 4A and 4B show transmission electron micrographs of typical microstructures found in the embodiment shown in FIGS. 1 and 2.
FIG. 5 shows optical and scanning electron microscope micrographs of typical microstructures present in the as-laser treated tube according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In one embodiment of the present invention it was found that scanning of final size Zircaloy-4 tubing by a high power laser beam would provide high temperature, high pressure steam corrosion resistance even though a Widmanstatten basket-weave microstructure was not achieved. It was found that material processed as described in the following examples could achieve high temperature, high pressure steam corrosion resistance even though optical metallographic examination of the material revealed it to have partially or fully recrystallized microstructural regions with a substantially uniform precipitate distribution typical of that observed in conventionally alpha worked and annealed Zircaloy tubing.
The laser treatments utilized in this illustration of the present invention are shown in Table I. In all cases a 10.6μ wavelength, 5 kilowatt laser beam was rastered over an area of 0.2 in.×0.4 in. (0.508 cm×1.08 cm) of conventionally fabricated, stress relief annealed, final size Zircaloy-4 tubing, the tubing having a mechanically polished (400-600 grit) outer surface, was simultaneously rotated and translated through the beam area under the conditions shown in Table I. As the tube rotation and tube withdrawal rates decreased, more energy was transmitted to the specimen surface and higher temperatures were attained. This relationship of tube speed to energy is illustrated by the increase in specific surface energy (that is energy striking a square centimeter of the tube surface) with decreasing tube rotation and tube withdrawal rates as shown in Table I. Although the treatment chamber was purged with argon at a rate of about 150 cubic feet/hour, most tubes were covered with a very light oxide coating upon exit from the chamber.
Representative sections of each treatment condition were metallographically polished to identify any microstructural changes that had occurred. Results obtained from optical metallography are listed in Table II, where it can be seen that no obvious microstructural effects were discerned until the rotation speed had been reduced to below 285 rpm, at which recrystallization occurred (241 rpm). At the next slowest speed (196 rpm) the whole tube was transformed to a Widmanstatten basket-weave structure, FIG. 3. Similar Widmanstatten structures were also observed at a rotation speed of 147 rpm. The structures produced at rotation speeds of 241 rpm and 285 rpm are shown in FIGS. 1 and 2, respectively. The only visible difference between the structures was that the 241 rpm sample had a fine recrystallized grain structure, whereas, the 285 rpm sample did not. Faster rotation speeds resulted in structures which were optically indistinguishable from the 285 rpm sample. In no case was a beta treated structure produced solely in an outer layer of the tubing. Both the 196 rpm sample, as well as the 147 rpm sample, had Widmanstatten basket-weave structures (FIGS. 3A and 3B) extending through the wall thickness. Microhardness measurements performed on these specimens indicated that significant softening occurred only in samples where the rotation speed was less than 241 rpm.
Sections of the laser treated tubing were pickled in 45% H 2 O, 45% HNO 3 and 10% HF to remove the oxide that had formed during the processing, and were subsequently corrosion tested in 454° C. (850° F.), 1500 psi steam to determine the effect of the various treatments on high temperature corrosion resistance. After five days corrosion exposure, all samples that had experienced rotation rates greater than 285 rpm had disintegrated, while those with comparable or slower rotation rates had black shiny oxide films. A summary of the corrosion data obtained after 30 days exposure in 454° C. steam is presented in Table III, as are data obtained on beta-annealed+water quenched Zircaloy-4 control coupons which were included in the exposures. It can be seen that the laser treated tubing generally had lower weight gains than the beta treated Zircaloy-4 control coupons. For comparison, conventionally processed cladding disintegrates after 5-10 days in the corrosion environment utilized.
Because beta-treated Zircaloy-4 with a Widmanstatten microstructure has good corrosion resistance in 454° C. steam, it was anticipated, on the basis of optical metallography, that the laser treated specimens with the Widmanstatten structure (FIG. 3) would also have good corrosion resistance. However, the change from catastrophic corrosion behavior to excellent corrosion behavior that occurred between rotation rates of 332 rpm and 285 rpm was not expected on the basis of optical metallography and forms the basis of this embodiment of the present invention. In order to determine what specific microstructural changes were responsible for this phenomena, transmission electron microscopy (TEM) samples were prepared from the 332-241 rpm tubing. The structures that are characteristic of these specimens are shown in FIGS. 4A and 4B. (The dark particles shown in these micrographs are not indigenous precipitates, but are oxides and hydride artifacts introduced during TEM specimen preparation.) All of the samples had areas which were well polygonized (FIG. 4A, area X) and/or recrystallized (FIG. 4B). The structures were quite similar, in overall appearance, to cold-worked Zircaloy-4 that had been subjected to a relatively severe stress relief anneal. Precipitate structures were typical of those in normally processed Zircaloy-4 tubing, although many precipitates were more electron transparent than normally expected, indicating that partial dissolution may have occurred. No qualitatively discernible difference between the specimens which had poor corrosion resistance and good corrosion resistance was noted. It is however theorized that dissolution of intermetallic compounds may result in enrichment of the matrix in Fe and/or Cr, thereby leading to the improved corrosion resistance observed.
In accordance with the present invention the above examples clearly illustrate that laser treating of Zircaloy-4 tubing so as to provide an incident specific surface energy at the treated surface of between approximately 288 and 488 joules per centimeter squared can produce Zircaloy-4 material which forms a thin, adherent and continuous oxide film upon exposure to high temperature and high pressure steam. Based on these corrosion test results it is believed that Zircaloy-4 material so treated will possess good corrosion resistance in boiling water reactor and pressurized water reactor environments.
While these materials in accordance with this invention possess the corrosion resistance of Zircaloy-4 having a Widmanstatten structure, it advantageously is believed to substantially retain the anisotropic texture produced in the alpha working of the material prior to laser treating, making it less susceptible to formation of hydrides in undesirable orientation with respect to the stresses seen by the component during service.
While the invention has been demonstrated using a laser beam, other high energy beams and methods of rapid heating and cooling may also be suitable. The heat up time to the elevated temperature for the above described rapid alpha-annealing treatments was about one third of a second or less (as calculated by dividing the major beam dimension by the tube translation speed, e.g. 0.4 inch/72 inches/minute=0.33 seconds, see tables I and II). Upon leaving the beam the Zircaloy immediately began to cool.
The values of specific surface energy cited above in accordance with the invention may of course vary with the material composition and factors, such as section thickness and material surface condition and shape, which may affect the fraction of the incident specific surface energy absorbed by the component.
It is also believed that the subject treatments are also applicable to other alpha zirconium alloys such as Zircaloy-2 alloys and zirconium-niobium alloys. It is also believed that the excellent corrosion resistance obtained by the described high energy beam heat treatment can be retained after further cold working and low temperature annealing of the material.
The material to be treated may be in a cold worked (with or without a stress relief anneal) or in a recrystallized condition prior to laser treatment.
In other embodiments of the present invention conventionally processed Zircaloy-2 and Zircaloy-4 tubes are scanned with a high energy laser beam which beta treats a first layer of tube material beneath and adjacent to the outer circumferential surface, producing a Widmanstatten grain and precipitate morphology in this layer while forming a second layer of alpha recrystallized material beneath this first layer (see FIG. 5). The treated tubes are then cold worked to final size and have been found to have excellent high temperature, high pressure steam corrosion resistance. The following examples are provided to more fully illustrate the processes and products in accordance with these embodiments of the present invention.
Note, as used in this application, the term scanning refers to relative motion between the beam and the workpiece, and either the beam or the workpiece may be actually moving. In all the examples the workpiece is moved past a stationary beam.
The laser surface treatments utilized in these illustrations of the present invention are shown in Table IV. In all cases a continuous wave CO 2 laser emitting a 10.6μ wavelength, 12 kilowatt laser beam was utilized. An annular beam was substantially focused onto the outer diameter surface of the tubing and irradiated an arc encompassing about 330° of the tube circumference. The focused arc had a diameter equal to the tube diameter and a length of 0.1 inch. The materials were scanned by the laser by moving the tubes through the ring-like beam. While being treated in a chamber continually being purged with argon, the tubes were rotated at a speed of approximately 1500 revolutions per minute while also being translated at the various speeds shown in inches per minute (IPM) in Table IV, so as to attain laser scanning of the entire tube O.D. surface. The variation in translation speeds or withdrawal or scanning speeds were used to provide the various levels of incident specific surface energy (in joules/centimeter squared) shown in Table IV. Under predetermined conditions of laser scanning, as the specific surface energy increases the maximum temperature seen by the tube surface and the maximum depth of the first layer of Widmanstatten structure, both increase. Rough estimates of the maximum surface temperature reached by the tube were made with an optical pyrometer and are also shown in Table IV. While these values are only rough estimates they can be used to compare one set of runs to another and they complement the calculated specific surface energy values since the latter are known to be effected by interference of the chamber atmospheric conditions on laser workpiece energy coupling.
The tubes treated included conventionally processed cold pilgered Zircaloy-2 and Zircaloy-4 tubes having a 0.65 inch diameter×0.07 inch wall thickness, and a 0.7 inch diameter×0.07 inch wall thickness, respectively. The tubes had a mill pickled surface. Ingot chemistries of the material used for the various runs are shown in Table V.
After the beta treatment the tubes were cold pilgered in one step and processed (e.g. centerless ground and pickled) to final size, 0.484 inch diameter×0.0328 inch wall thickness, and 0.374 inch diameter×0.023 inch wall thickness for the Zircaloy-2 and Zircaloy-4 heats, respectively.
Representative sections from various runs were then evaluated for microstructure, corrosion properties, and hydriding properties. Microstructural evaluation indicated that for the runs shown in Table IV the Widmanstatten structure originally produced in the 0.070 inch wall typically extended inwardly from the surface to a depth of from 10 to 35 percent of the wall thickness, depending upon the beta treatment temperature. The absolute value of these first layer depths, of course, decreased significantly due to the reduction in wall thickness caused by the final cold pilgering.
Lengths of tubing from the various runs were then pickled and corrosion tested in high temperature, high pressure steam and the data are as shown in Tables VI and VII. It will be noted that in all cases the samples processed in accordance with this invention had significantly lower weight gains than the conventionally alpha worked material included in the test standards. It was noted, however, that in some cases varying degrees of accelerated corrosion were observed on the laser beta treated and cold worked samples (see Table VI 1120° C., and 1270°-1320° C. materials). These are believed to be an artifact of the experimental tube handling system used to move the tube under the laser beam which allowed some portions of tubes to vibrate excessively while being laser treated. These vibrations are believed to have caused portions of the tube to be improperly beta treated resulting in a high variability in the thickness of the beta treated layer around the tube circumference in the affected tube sections, causing the observed localized areas of high corrosion. It is therefore believed that these incidents of accelerated corrosion are not inherent products of the present invention, which typically produces excellent corrosion resistance.
Oxide film thickness measurements performed on the corrosion-tested laser-treated and cold-worked Zircaloy-4 samples from the tests represented in Table VI surprisingly indicated that the inside diameter surface, as well as the outside diameter surface, both had equivalent corrosion rates. This was true for all the treatments represented in Table VI except for the 1120° C. treatment, where the inner wall surface had a thicker oxide film than the outer wall surface.
Based on the preceding high temperature, high pressure steam corrosion tests it is believed that these alpha Zirconium alloys will also have improved corrosion resistance in PWR and BWR environments.
The mechanical property characteristics and hydriding characteristics of the treated materials were found to be acceptable.
In this invention since only a surface layer of the intermediate tube is beta treated, it is believed that the crystallographic texture of the final product can be more easily tailored to provide desired final properties compared to the method disclosed in U.S. Pat. No. 3,865,635. In this invention both the alpha working before and after the surface beta treatment can be used to form the desired texture in the inner layer of the tube.
Both good outside diameter and inside diameter corrosion properties have been achieved by laser surface treating and cold working according to this invention, without resort to the precipitate size control steps of copending application Ser. No. 343,787, (filed on Jan. 29, 1982 and assigned to Westinghouse Electric Corporation) prior to the laser treating step, as demonstrated by the preceding examples. However, in another embodiment of the present invention, the process of the copending application, utilizing reduced extrusion and intermediate annealing temperature, may be practiced in conjunction with the high energy beam beta treatments of this invention. In this embodiment, the high energy beam surface treatment would be substituted for the intermediate anneal at step 5, 7 or 9, of the copending application. The intermediate product, in the surface beta treated condition, would have an outer layer having a Widmanstatten microstructure adjacent and beneath one surface, and an inner layer, beneath the outer layer, having recrystallized grain structure with the fine precipitate size of the copending application. Subsequent working and annealing in accordance with the present invention would produce a final product having a substantially random precipitate distribution and a fine precipitate size in its inner layer.
In applying the present process to Zirconium-niobium alloys it is preferred that the material be aged at 400°-600° C. after cold working. This aging will occur during intermediate and final anneals performed on the material after the laser surface treatment.
The above examples of this invention are only illustrative of the many possible products and processes coming within the scope of the attached claims.
TABLE I__________________________________________________________________________LASER PROCESSING PARAMETERS FOR HEAT TREATMENTOF FINISHED DIMENSION ZIRCALOY TUBING Calculated incident Tube Beam Laser Tube Tube Power SpecificCondition Dimensions Configuration Power Rotation Withdrawal Density Surface EnergyNo. (dia/wall) (Line Source)* (on work) RPM/1PM** 1PM KW/cm.sup.2 J/cm.sup.2__________________________________________________________________________1 0.375"/0.022" 0.2" × 0.4" 5 KW 485/590 146 9.7 1972 0.375"/0.022" 0.2" × 0.4" 5 KW 473/574 142 9.7 2023 0.375"/0.022" 0.2" × 0.4" 5 KW 455/552 137 9.7 2104 0.375"/0.022" 0.2" × 0.4" 5 KW 430/521 129 9.7 2235 0.375"/0.022" 0.2" × 0.4" 5 KW 407/494 122 9.7 2356 0.375"/0.022" 0.2" × 0.4" 5 KW 376/456 113 9.7 2547 0.375"/0.022" 0.2" × 0.4" 5 KW 332/403 100 9.7 2888 0.375"/0.022" 0.2" × 0.4" 5 KW 285/345 86 9.7 3369 0.375"/0.022" 0.2" × 0.4" 5 KW 241/293 72 9.7 39810 0.375"/0.022" 0.2" × 0.4" 5 KW 196/238 59 9.7 48811 0.375"/0.022" 0.2" × 0.4" 5 KW 147/178 44 9.7 651__________________________________________________________________________ *Major dimension of beam (0.4") aligned parallel to rotational axis of tube. **1PM = inches per minute = vector sum of the rotational velocity and translational velocity (tube withdrawal 1PM).
TABLE II______________________________________ZIRCALOY-4 LASER HEAT TREATMENTSRotation Translation OpticalRate Rate Microstructural Microhardness(rpm) (in/min) Observations (kg/mm.sup.2)______________________________________485 145.5 No Observable Effect 219473 142 " 228455 136.5 " 215430 129 " 228407 122 " 222376 113 " 224332 100 " 223285 85.5 " 207241 72 Fine Recrysrallized 222 Structure196 59 Widmanstatten Structure 196147 44 Widmanstatten Structure 196______________________________________
TABLE III______________________________________454° C. (850° F.) CORROSION DATA OBTAINED ONLASER TREATED ZIRCALOY-4 TUBINGEXPOSED FOR 30 DAYS Mean Weight GainSample (mg/dm.sup.2)______________________________________285 rpm 168241 rpm 217196 rpm 207147 rpm 211Beta-Annealed (950° C.) + 262Water Quenched______________________________________
TABLE IV__________________________________________________________________________LASER PROCESSING PARAMETERS FOR HEAT TREATMENTOF INTERMEDIATE DIMENSION ZIRCALOY TUBING Calculated Incident Tube Beam Laser Tube Tube Power Specific EstimatedRun Dimensions Configuration Power Rotation Withdrawal Density Surface Energy MaximumNo. (dia/wall) (ring) (on work) RPM 1PM KW/cm.sup.2 J/cm.sup.2 Surface Temp.__________________________________________________________________________ (Zr-4)23 0.700/0.070 0.7" × 0.1" 12 KW ˜1500 20 8.5 255024 " " " " " " "25 " " " " " " "26 " " " " " " " ˜1210° C.27 " " " " " " "28 " " " " " " "29 0.700/0.070 0.7" × 0.1" 12 KW ˜1500 24 8.5 212530 " " " " " " "31 " " " " " " " ˜1150° C.32 " " " " " " "33 " " " " " " "34 0.700/0.070 0.7" × 0.1" 12 KW ˜1500 28 8.5 182035 " " " " " " " ˜1120° C.36 " " " " " " "37 " " " " " " "41 " " " " 29 " 175945 " " " " 29 " 1759 ˜1270-1320° C.46 " " " " 31 " 164542 0.700/0.070 0.7" × 0.1" 12 KW ˜1500 32 8.5 159447 " " " " 31 " 1645 ˜1230° C.48 " " " " 33 " 1545 (Zr-2)49 0.650/0.070 0.65" × 0.1" 12 KW ˜1500 33 9.1 165450 " " " " " " " ˜1160-1175° C.51 " " " " " " "52 0.650/0.070 0.65" × 0.1" 12 KW ˜1500 28 9.1 195053 " " " " " " " ˜1300-1320° C.54 " " " " " " "55 0.650/0.070 0.65" × 0.1" 12 KW ˜1500 30 9.1 182056 " " " " " " " ˜1210-1275° C.57 " " " " " " "58 " " " " " " "59 0.650/0.070 0.65" × 0.1" 12 KW ˜1500 34 9.1 160560 " " " " " " " ˜1175-1185° C.61 " " " " " " "62 0.650/0.070 0.65" × 0.1" 12 KW ˜1500 36 9.1 1517 ˜1170° C.63 " " " " " " "__________________________________________________________________________
TABLE V______________________________________INGOT CHEMISTRY OF ZIRCALOY TUBESPROCESSED IN ACCORDANCE WlTH THE INVENTION Zircoloy-4Zircaloy-4 Heat A Heat B Zircaloy-2Run Nos. 23-43 Run Nos. 44-48 Run Nos. 49-63______________________________________Sn 1.46-1.47 w/o 1.42-1.52 w/o 1.44-1.63 w/oFe .22-.23 w/o .19-.23 w/o .14-.16 w/oCr .11-.12 w/o .10-.12 w/o .11 -.12 w/oNi <50 ppm <35 ppm .05-.06 w/oAl 42-46 ppm 39-58 ppm <35 ppmB <0.5 ppm <0.25 ppm <0.2 ppmCa NR <15 ppm NRCd <0.5 ppm <0.25 ppm <0.2 ppmC 115-127 ppm 125-165 ppm 10-40 ppmCl <10 ppm 7-11 ppm <10 ppmCo <10-13 ppm <10 ppm <10 ppmCu <10 ppm <25-44 ppm <25 ppmHf 52-53 ppm <80-84 ppm 51-57 ppmMn <10 ppm <25 ppm <25 ppmMg <10 ppm <10 ppm <10 ppmMo <20 ppm < 25 ppm <25 ppmPb NR <25 ppm NRSi 52-54 ppm 60-85 ppm 99-119 ppmNb <50 ppm <50 ppm NRTa 100 ppm <100 ppm NRTi 18-48 ppm <25 ppm <25 ppmU <0.5 ppm <1.8 ppm <1.8 ppmU235 .002-.004 ppm .010 ppm NRV <20 ppm <25 ppm NRW <50 ppm <50 ppm <50 ppmZn <50 ppm NR NRH 2-18 (12-17) ppm 5-7 ppm (<12) ppmN 35-40 (35-43) ppm 40 ppm (21-23) ppmO 1100-1140 1200-1400 ppm (1350-1440) ppm(1100-1200) ppm______________________________________ Values reported typically represent the range of analyses determined from various positions on the ingot. Values in parentheses represent the range of analyses as determined on TREX. NR = not reported
TABLE VI__________________________________________________________________________AS PILGERED ZIRCALOY-4 TUBING850° F. 1500 PSI, 20 DAY EXPOSURECORROSION TEST RESULTS Weight Gain Estimated Approximate (mg/dm.sup.2)Run Nos. Maximum Surface Temp. .sup.--X* S* Remarks__________________________________________________________________________34, 35, 36, 37 1120° C. 230.2 12.5 Accelerated corrosion occurred on 8 of 12 coupons29, 30, 31, 1152° C. 86.3 4.8 Adherent black continous oxide on OD and ID32, 3323, 24, 25, 1210° C. 95.8 9.6 Adherent black continous oxide on OD and ID26, 27, 2842, 47, 48 1230° C. 105.6 10.4 Adherent black continous oxide on OD and ID41, 45, 46 1270-1320° C. 83.4 6.9 Adherent black continous oxide on OD and ID 285.0 79.0 White oxide on portions of samples, but not spallingZircaloy-4 445.2 48 Exposure terminated at 10 days due toStandards white spalling oxide__________________________________________________________________________ *.sup.--X = mean weight gain *S = estimated standard deviation
TABLE VII__________________________________________________________________________AS PILGERED ZIRCALOY-2 TUBING935° F., 1500 PSI 24 HOUR EXPOSURECORROSION TEST RESULTS Weight GainEstimated Approximate (mg/dm.sup.2)Maximum Surface Temp. .sup.--X S Remarks__________________________________________________________________________1170-1185° C. 52.9 14.7 Adherent black continous oxide on OD and ID1210-1275° C. 50.6 2.9 Adherent black continous oxide on OD and ID1300-1320° C. 65.6 5.4 Adherent black continous oxide on OD and IDZircaloy-2 261.4 51.9 White spalling oxide at edges of couponsstandards__________________________________________________________________________
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Described herein are alpha zirconium alloy fabrication methods and resultant products exhibiting improved high temperature, high pressure steam corrosion resistance. The process, according to one aspect of this invention, utilizes a high energy beam thermal treatment to provide a layer of beta treated microstructure on an alpha zirconium alloy intermediate product. The treated product is then alpha worked to final size. According to another aspect of the invention, high energy beam thermal treatment is used to produce an alpha annealed microstructure in a Zircaloy alloy intermediate size or final size component. The resultant products are suitable for use in pressurized water and boiling water reactors.
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This application claims the benefit of Provisional Application No. 60/351,577, filed Jan. 25, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to wall covering borders and layer sheets of wall covering that are attached to a wall without wallpaper paste or other type of adhesive, and more particularly to wall covering borders and wall covering in general that are attached to a wall by placing them into a channel or clip.
2. Description of Prior Art
Wall coverings are used to provide a decoration for walls. These coverings offer an alternative from painting by providing more decorative and design options. Wall coverings can also be used as borders or trim on walls, providing a touch of color or design on an otherwise plain wall surface. However, wall coverings, either full or borders, must be pasted or adhered to walls making them a permanent decoration. The result is that, when a wall covering is removed, the wall itself is often damaged, requiring it to be patched and repainted or recovered. Changing wallpaper, either as a trim or for a larger portion of a wall, is difficult since the old paper must be removed which is a time consuming and tedious process, and is generally frowned upon by the owners of residences, rental units, stores, offices or cottages where such changes are more likely to occur (or at least be more desirable) due to the change in tenants. Thus, owners of rental homes, apartments, offices and stores usually will not permit the renters or temporary dwellers to apply new wall coverings or change existing ones. There is a desire of building owners in particular, and of others who are responsible for changes in wall design, to have a pasteless wall paper system for changing wall paper without having to scrape off or otherwise remove old wallpaper before installing new wall paper. In addition, there is a desire for those decorating walls to have a fast and inexpensive way to change wall paper. Further, it is difficult to apply traditional wall coverings or wall borders to textured or non-smooth walls.
SUMMARY OF THE INVENTION
The present invention provides a solution to the problems of the prior art with a pasteless wall covering system in which wall covering becomes easily installable, removable, changeable and reusable without damaging walls. This invention will allow apartment and other rental property owners, such as store and office owners, to encourage tenants to change wall decorations to suit individual tenant's tastes, and will also enable tenants to easily install and change wall decorations on non-smooth or textured wall surfaces. The invention has particular advantages for wall covering borders but it can be used for larger sections of wall coverings as well. Further, it could be used with non-paper wall coverings such as fabric, carpeting, etc.
In accordance with a preferred embodiment of the present invention, a conventional wall covering border is attached to a semi-rigid paper type stock, or a decoration is printed onto a semi-rigid paper type stock, creating a semi-rigid wall covering border. Likewise, the semi-rigid paper stock can itself carry the decoration and form the border. A holder for the semi-rigid wall covering border is created by scoring and folding a channel that is stapled or otherwise attached to the wall surface at the desired wall covering border location.
An object of this invention is to provide an article that serves as a wall covering border or wall covering and is easy to install and change.
A further object of this invention is to provide an article that serves as a wall covering border or wall covering and is interchangeable.
A further object of this invention is to provide an article that serves as a wall covering border or wall covering and does not damage the wall surfaces when removed.
Yet another object of this invention is to provide an article that serves as a wall covering border or wall covering and can go over smooth or textured surfaces.
Yet another object of this invention is to provide an article that serves as a wall covering border or wall covering and is reusable.
Yet another object of this invention is to provide an article that serves as a wall covering border or wall covering and is inexpensive.
Yet another object of this invention is to provide an article that serves as a wall covering border or wall covering and has no pattern matching required.
Yet another object of this invention is to provide an article that serves as a wall covering border or wall covering and is supplied in a continuous roll.
Still another object is to provide a wall paper system for providing a pasteless or adhesiveless wall paper that can be easily and quickly changed.
These and other objects will become apparent from the following description of a preferred embodiment taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is an end perspective view of a wall covering border in a holder;
FIG. 2 is an end view of the wall covering border in the holder of FIG. 1 ;
FIG. 2 a is a top view of the holder prior to folding the channels;
FIG. 3 is a side view of a two layer or two member wall covering border;
FIG. 3 a is a side view of a one piece wall covering border;
FIG. 4 is a side view of the two piece wall covering border in a holder;
FIG. 5 is a perspective view of the wall covering border in a holder,
FIG. 6 is a perspective view of the wall covering border in a holder,
FIG. 7 is a front perspective view of an interior or exterior corner;
FIG. 8 is a top view of the wall covering border corner piece; and
FIG. 9 is a front perspective view of a wall covering border in a holder on a wall.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein the showings are for the purpose of illustrating the preferred embodiment of the invention only, and not for the purpose of limiting same, FIG. 1 and FIG. 2 show a wall covering border 2 in a holder 4 . The holder 4 can be can preferably be made of PVC or other materials, can be flexible or made of flexible materials, and can preferably have a matte finish that does not reflect light. The length of the holder can be as short as about three feet. A preferred length can be between six and thirty feet. The holder 4 has a top longitudinal side 6 , a bottom longitudinal side 8 , and a support 9 including a front surface 10 and a back surface 12 . The longitudinal sides 6 , 8 of the holder 4 are folded over twice to form channels, top channel 16 and bottom channel 18 , each having a base 20 a , 20 b , and a channel or fold lip 22 a , 22 b with a fold or channel edge 24 a , 24 b , extending along the length of the holder 4 . The channels 16 , 18 hold the wall covering border 2 when it is installed on the wall. As shown in FIG. 2 a , the holder can be scored with score lines 26 in the front surface 10 so that it can be stored and distributed without channels and folded to create the channels 16 , 18 at the installation site.
Numerous attachments means can be used to attach the back surface 12 of the holder 4 to a wall. Such means include hook and latch systems such as Velcro®, adhesives, double faced tape, staples, or glue. In a preferred embodiment, the top channel lip 22 a is larger than the bottom channel lip 22 b. In a preferred embodiment, the channel lips 22 a, 22 b, are biased in an inward direction, that is, the channel lips have “memory”, so that they press against the wall paper border, holding the border firmly in place.
FIG. 3 shows the wall covering border 2 which is comprised of a top member 28 and a bottom member 30 . The top member 28 can preferably be made of wall covering material, which can be from 2″ to 30″ wide, and, in one preferred embodiment, from 6¼″ to 6¾″ wide. The bottom member 30 can be made of a semi-rigid paper stock. The paper stock, or alternative material, should be flexible enough so that wall covering border 2 can be changed from a flat position to a roll for storing and transporting. The bias of the roll could help keep it in place in the holder. For the bottom member 30 , a material having one side covered with pressure sensitive adhesive can be used to so that the bottom member 30 can be inexpensively and simply attached to the top member 28 . In the alternative, as shown in FIG. 3 a, the decoration can be placed directly on a semi-rigid paper stock 32 .
FIG. 4 shows a second embodiment, wherein the holder 40 is separated into two pieces, each “J” shaped and having a back 42 , an upper wall 44 and a front or top 46 . A channel 48 is formed between the top 46 and the back 42 of the holder 40 , there being two channels 48 for each assembly. FIG. 5 shows another embodiment, wherein the holder 50 can preferably be made of molded foam, channeled wood or other moldable, semi-rigid material. In the alternative, the holder 50 can be made of rigid or semi-rigid PVC with clear edges, similar to the material found in vertical blinds. The front 52 of the holder 50 can be rounded or angled. A pair of opposing channels 54 are formed between the front 52 and the back 56 of the holder 50 .
Another embodiment of the invention is shown in FIG. 6 in which the holder 60 , attached to a wall 62 , is the hook-type material of a hook and latch connecting system, such as Velcro, and the latch material 64 is attached to the back of the wall covering border 2 . In the alternative, the holder 60 could be made of double faced adhesive tape.
FIG. 7 shows a corner piece 70 , which can be used at the junction of walls, typical inside corners as well as outside corners. These corner pieces can be made of rigid PVC vinyl, wood, foam, plastic or other materials. The holder 4 and wall covering border 2 can be applied to each wall forming the juncture and the corner piece 70 can be inserted into the corner, abutting holder. In the embodiment shown in FIG. 7 , the corner piece can contain slots 72 into which the wall covering border 2 can be inserted. In the alternative, the wall covering border may abut the corner piece. In a preferred embodiment, the wall covering border 2 and holder 4 may be bent to wrap the corner; no special corner piece would be necessary.
FIG. 8 shows a corner piece 80 which can be used in a non-square corner, that is, a corner that is not 90°. This corner piece 80 has a center score-line 82 along which it can be bent or folded, creating the desired corner angle. In addition, a channel 84 is formed between the top 86 , the side 88 and the back 90 of the corner piece 80 , there being two channels 84 for each corner piece 80 . The top 86 and the side 88 of the channel 84 do not extend the entire length of the wall covering border holder; instead, each terminates before reaching the score-line 82 , enabling the corner piece to bend and form the corner angle. There are vertical score-lines 92 along which the corner piece can be folded to create the top and the side of the channel.
Installation of the current invention is easy. In the embodiment shown in FIGS. 1 and 2 , channels 16 , 18 are created by folding the holder 4 along the scored lines 26 . In all of the embodiments, the holder 4 , 40 , 50 , 60 is attached to the wall using fasteners such as clips, staples, or adhesives such as pressure sensitive adhesives and double faced tape. Key shaped holes can be made in the backs of the holder having an enlarged bottom portion and a narrow top portion. A screw or other fastener can be inserted in a wall with its top end extending outwardly from the wall, and the back of the holder can be placed so that the head of the fastener extends through the enlarged bottom portion hole. The holder can then be released so that the fastener supports the holder through the upper edge of the narrow portion of the hole. Once the holder is secured on the wall, the wall covering border 2 is unrolled and inserted into the holder 4 , preferably by sliding it into the channel 16 , 18 , 48 , 54 along the wall. Corner pieces, which can be made of rigid PVC vinyl, wood, foam or plastic, can be used at the junction of walls. These corner pieces can contain slots into which the wall covering border can be inserted. Corner pieces can be used in typical inside corners as well as outside corners; in both cases, the channel 16 , 18 , 48 , 54 and wall covering border 2 can be applied to each wall forming the juncture. The wall covering border 2 may wrap the corner, if it is pliable enough.
Changing the wall paper is very easy. The user simply grasps the end portion of the wall paper and withdraws it from the holder, and inserts a replacement wall paper by forcing it between the front and back of the holder.
The invention has been described with particular emphasis on the preferred embodiments. It should be appreciated that these embodiments are described for purposes of illustration only, and that numerous alterations and modifications may be practiced by those skilled the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention or the equivalents thereof.
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The present invention provides a pasteless wall covering system in which wall covering becomes easily installable, removable, changeable and reusable without damaging walls. A wall covering border is attached to, or made from, a semi-rigid paper stock and is held on the wall by a holder with channels. The holder can be created by scoring and folding a top and bottom channel. The holder can be attached to the wall by stapling, adhesives or other attachment means.
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BACKGROUND
[0001] 1. Field of Invention
[0002] The present invention relates generally to an applicator. More specifically, the present invention relates to a one-piece brush applicator formed by rolling a sheet of material.
[0003] 2. Description of Related Art
[0004] Brushes in various forms are used for various applications. The applications vary from brooms, paint brush, to cosmetic applicator brushes. Generally the brushes are formed from various materials, such as wood, metal, plastic, and animal or artificial hairs. A conventional brush generally comprises of a handle, a section that affixes the brush portion to the handle, and the brush tip. Often the three main components are all made of different material and are assembled together to form the final brush applicator. The process requires the separation formation of a handle, a section that affixes the brush portion to the handle, and a brush tip. A separate assembly process is required to assemble the three main components.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention is a one-piece brush applicator formed by rolling a sheet of material. The brush handle and the brush tip are formed from a single sheet of material that is rolled to form the brush with a handle. Only one material is required and no assembly is necessary. The brush handle and the brush tip are formed at the same time from a single sheet of material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows the preferred embodiment of the brush before the sheet of material is rolled.
[0007] FIG. 2 shows the preferred embodiment of the brush after the sheet of material is rolled to form the brush with a flat tip.
[0008] FIG. 3 shows another embodiment of the brush before the sheet of material is rolled.
[0009] FIG. 4 shows yet another embodiment of the brush before the sheet of material is rolled.
[0010] FIG. 5 shows the embodiment of the brush shown in FIG. 4 after the sheet material is rolled to form the brush with a pointed tip.
[0011] FIG. 6 shows yet another embodiment of the brush before the sheet of material is rolled.
[0012] FIG. 7 shows the embodiment of the brush shown in FIG. 6 after the sheet of material is rolled to form the brush with a pointed tip and a narrow handle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] The following description and figures are meant to be illustrative only and not limiting. Other embodiments of this invention will be apparent to those of ordinary skill in the art in view of this description.
[0014] FIG. 1 shows the preferred embodiment of the present invention. In the preferred embodiment, the brush comprises of a flat sheet of material 1 , preferably plastic. However, the sheet of material 1 may be selected from a variety of other materials such as paper, cotton, or any other suitable flexible materials. In the preferred embodiment, the sheet of material 1 is generally rectangular shape with fine slits 2 formed along one edge of the sheet of material 1 . Multiple parallel thin strips 3 are formed along one edge of the sheet of material 1 defined by the fine slits 2 . The slits 2 may be formed by simply making multiple parallel cuts along one edge of the sheet of material 1 leaving a portion of the sheet of material 1 intact. Alternatively, instead of fine slits, the edge of the sheet of material 1 may be frayed, particularly if the sheet of material is made of cotton or paper.
[0015] The sheet of material 1 is then rolled parallel to the multiple thin strips 3 with the final loose edge affixed to the rolled sheet of material 1 to form the final brush as shown in FIG. 2 . The loose edge may be affixed to the rolled sheet of material 1 by an adhesive or any other suitable means. The brush that is formed in this embodiment has a flat tip 4 and an elongated cylindrical handle 5 that is approximately the width of the brush tip 4 . If the sheet of material 1 is rolled tightly, there is virtually no space in the core of the brush. However, if the sheet of material 1 is rolled with a small hollow core left in its center, a fluid flow path is left in the brush through which a fluid may flow through core of the handle 5 into the brush tip 4 . Alternatively, the edge of the sheet of material 1 with the slits 2 may be formed with different profiles such as a wave pattern to form brush tips 4 with different contours. If the edge of the sheet of material 1 is frayed, the resulting tip will be a flexible applicator tip similar to a cotton swab.
[0016] Additionally, the opposite edge of the sheet of material may also have either fine slits formed along the edge or frayed. In this embodiment, the resulting applicator has a brush or a flexible applicator tip similar to a cotton swab, respectively, on both ends of the applicator.
[0017] FIG. 3 shows another embodiment of the present invention. In this embodiment, the brush comprises of a flat sheet of material 1 , preferably plastic. The sheet of material 1 is generally rectangular shape with fine slits 2 formed along one edge of the sheet of material 1 . Multiple parallel thin strips 3 are formed along one edge of the sheet of material 1 defined by the fine slits 2 . The opposite edge and the adjacent portion of the sheet of material 1 are left intact without any slits. Multiple grooves 6 are formed on the sheet of material 1 at this portion of the sheet of material 1 without the slits. When this sheet of material 1 is rolled to form the final brush, multiple fluid flow paths are formed at the location of the grooves 6 in the sheet of material 1 through which a fluid may flow through the grooves 6 in the handle into the brush tip.
[0018] FIG. 4 shows another embodiment of the present invention. In this embodiment, the brush comprises of a flat sheet of material 7 , preferably plastic. In this embodiment, the sheet of material 7 is generally a trapezoid shape with fine slits 8 formed along one non-parallel/slanted edge of the sheet of material 7 . Multiple parallel thin strips 9 are formed along the non-parallel/slanted edge of the sheet of material 7 defined by the fine slits 8 . The lengths of the parallel thin strips 9 vary from the longest at one end of the edge to the shortest at the other end of the edge.
[0019] The sheet of material 7 is then rolled parallel to the multiple thin strips 9 with the final loose edge affixed to the rolled sheet of material 7 to form the final brush as shown in FIG. 5 . The loose edge may be affixed to the rolled sheet of material by an adhesive or any other suitable means. The brush that is formed in this embodiment has a pointed tip 10 and an elongated cylindrical handle 11 that is approximately the width of the brush tip 10 . If the sheet of material 7 is rolled tightly, there is virtually no space in the core of the brush. However, if the sheet of material 7 is rolled with a small hollow core left in its center, a fluid flow path is left in the brush through which a fluid may flow through core of the handle 11 into the brush tip 10 . Similar multiple grooves 6 may also be formed as in FIG. 3 through which a fluid may flow through the grooves 6 in the handle into the brush tip.
[0020] FIG. 6 shows another embodiment of the present invention. In this embodiment, the brush comprises of a flat sheet of material 12 , preferably plastic. In this embodiment, the sheet of material 12 is generally a trapezoid shape with one corner of the material removed. Preferably the portion that is removed is generally a rectangular shape and is from a corner of the sheet of material 12 that has an approximate right angle. Fine slits 13 are formed along one non-parallel/slanted edge of the sheet of material 12 . Multiple parallel thin strips 14 are formed along the non-parallel/slanted edge of the sheet of material 12 defined by the fine slits 13 . The lengths of the parallel thin strips 14 vary from the longest at one end of the edge to the shortest at the other end of the edge near the corner with the material removed.
[0021] The sheet of material 12 is then rolled parallel to the multiple thin strips 14 with the final loose edge affixed to the rolled sheet of material 12 to form the final brush as shown in FIG. 7 . The loose edge may be affixed to the rolled sheet of material 12 by an adhesive or any other suitable means. The brush that is formed in this embodiment has a pointed tip 15 and a elongated cylindrical handle 16 that has a diameter smaller than the width at the bottom of the brush tip 15 . If the sheet of material 12 is rolled tightly, there is virtually no space in the core of the brush. However, if the sheet of material 12 is rolled with a small hollow core left in its center, a fluid flow path is left in the center of the brush through which a fluid may flow through core of the handle 16 into the brush tip 15 . Similar multiple grooves 6 may also be formed as in FIG. 3 through which a fluid may flow through the grooves 6 in the handle into the brush tip.
[0022] In all the embodiments, instead of the fine slits, the edge of the sheet of material may be frayed, particularly if the sheet of material is made of cotton or paper. When the edge of the sheet of material is frayed, the resulting tip will be a flexible applicator tip similar to a cotton swab.
[0023] Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
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A one-piece brush applicator formed by rolling a sheet of material is disclosed. The brush handle and the brush tip are formed from a single sheet of material that is rolled to form the brush with the handle. Only one material is required and no assembly is necessary. The brush handle and the brush tip are formed at the same time from a single sheet of material. The brush tip may have various shapes such as a flat tip or a pointed tip.
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RELATED APPLICATION DATA
This application is a continuation of U.S. patent application Ser. No. 11/465,405, filed Aug. 17, 2006 (now U.S. Pat. No. 7,650,008) which is a continuation of U.S. patent application Ser. No. 10/778,762, filed Feb. 13, 2004 (now U.S. Pat. No. 7,099,492). The Ser. No. 10/778,762 application is a division of U.S. patent application Ser. No. 09/800,093, filed Mar. 5, 2001 (now U.S. Pat. No. 7,061,510). The above U.S. Patent documents are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to image management and processing, and is particularly illustrated in the context of near real-time management of satellite and other aerial imagery, and automatic revision of map data based on such imagery.
BACKGROUND AND SUMMARY OF THE INVENTION
Acquisition of aerial imagery traces its history back to the Wright brothers, and is now commonly performed from satellite and space shuttle platforms in addition to aircraft.
While the earliest aerial imagery relied on conventional film technology, a variety of electronic sensors are now more commonly used. Some collect image data corresponding to specific visible, UV or IR frequency spectra (e.g., the MultiSpectral Scanner and Thematic Mapper used by the Landsat satellites). Others use wide band sensors. Still others use radar or laser systems (sometimes stereo) to sense topological features in 3 dimensions.
The quality of the imagery has also constantly improved. Some satellite systems are now capable of acquiring image and topological data having a resolution of less than a meter. Aircraft imagery, collected from lower altitudes, provides still greater resolution.
For expository convenience, the present invention is particularly illustrated in the context of a Digital Elevation Model (DEM). A DEM, essentially, is an “elevation map” of the earth (or part thereof). One popular DEM is maintained by the U.S. Geological Survey and details terrain elevations at regularly spaced intervals over most of the U.S. More sophisticated DEM databases are maintained for more demanding applications, and can consider details such as the earth's pseudo pear shape, in addition to more localized features. Resolution of sophisticated DEMs can get well below one meter cross-wise, and down to centimeters or less in actual elevation. DEMs—with their elevation data—are sometimes supplemented by albedo maps (sometimes termed texture maps, or reflectance maps) that detail, e.g., a grey scale value for each pixel in the image, conveying a photographic-like representation of an area.
There is a large body of patent literature that illustrates DEM systems and technology. For example:
U.S. Pat. No. 5,608,405 details a method of generating a Digital Elevation Model from the interference pattern resulting from two co-registered synthetic aperture radar images.
U.S. Pat. No. 5,926,581 discloses a technique for generating a Digital Elevation Model from two images of ground terrain, by reference to common features in the two images, and registration mapping functions that relate the images to a ground plane reference system.
U.S. Pat. Nos. 5,974,423, 6,023,278 and 6,177,943 disclose techniques by which a Digital Elevation Model can be transformed into polygonal models, thereby reducing storage requirements, and facilitating display in certain graphics display systems.
U.S. Pat. Nos. 5,995,681 and 5,550,937 detail methods for real-time updating of a Digital Elevation Model (or a reference image based thereon), and are particularly suited for applications in which the terrain being mapped is not static but is subject, e.g., to movement or destruction of mapped features. The disclosed arrangement iteratively cross-correlates new image data with the reference image, automatically adjusting the geometry model associated with the image sensor, thereby accurately co-registering the new image relative to the reference image. Areas of discrepancy can be quickly identified, and the DEM/reference image can be updated accordingly.
U.S. Pat. No. 6,150,972 details how interferometric synthetic aperture radar data can be used to generate a Digital Elevation Model.
From systems such as the foregoing, and others, a huge quantity of aerial imagery is constantly being collected. Management and coordination of the resulting large data sets is a growing problem.
In accordance with one aspect of the present invention, digital watermarking technology is employed to help track such imagery, and can also provide audit trail, serialization, anti-copying, and other benefits.
In accordance with another aspect of the invention, incoming imagery is automatically geo-referenced and combined with previously-collected data sets so as to facilitate generation of up-to-date DEMs and maps.
The foregoing and additional features and advantages of the present invention will be more readily apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a flow chart of steganographically embedding auxiliary data in imagery.
FIG. 2 shows a flow chart of steganographically hiding information in media.
FIG. 3 shows a flow chart of steganographically hiding or embedding information in an image or media, including an act of decoding first information hidden or embedded in the media or image.
FIG. 4 shows a flow chart of steganographically hiding or embedding second information in media or an image, including overlaying the first information.
FIG. 5 shows a flow chart of steganographically hiding or embedding second information in media or an image, including overwriting the first information.
DETAILED DESCRIPTION
(For expository convenience, the following specification focuses on satellite “imagery” to illustrate the principles of the invention. The principles of the invention, however, are equally applicable to other forms of aerial surveillance data and other topographic/mapping information. Accordingly, the term “image” should be used to encompass all such other data sets, and the term “pixel” should be construed to encompass component data from such other data sets.)
When new aerial imagery is received, it is generally necessary to identify the precise piece of earth to which it corresponds. This operation, termed “georeferencing” or “geocoding,” can be a convoluted art and science.
In many systems, the georeferencing begins with a master reference system (e.g., latitude and longitude) that takes into account the earth's known deformities from a sphere. Onto this reference system the position of the depicted region is inferred, e.g., by consideration of the satellite's position and orientation (ephemeris data), optical attributes of the satellite's imaging system, and models of the dispersion/refraction introduced by the earth's atmosphere.
In applications where precise accuracy is required, the foregoing, “ephemeris,” position determination is refined by comparing features in the image with the placement of known features on the earth's surface (e.g., buildings and other man-placed objects, geological features, etc.) and compensating the georeference determination accordingly. Thus, for example, if the actual latitude and longitude of a building is known (e.g., by measurement from a ground survey—“ground truth”), and the corresponding latitude and longitude of that building as indicated in the georeferenced satellite imagery is different, the reference system applied to the satellite data can be altered to achieve a match. (Commonly, three or more such ground truth points are used so as to assure accurate correction.)
Ground-truthing is a tedious undertaking. While computer methods can be used to facilitate the process, the best ground truth correction of imagery generally requires some human involvement. This is impractical for many applications.
Let us consider the basic principle of cost/meter as a useful metric, and imagine that various applications for exploiting satellite data are willing to pay different amounts in order to achieve given levels of geocoding accuracy. The following disclosure hypothesizes that there are ways (possibly novel, alluding to the idea that the author lacks detailed knowledge of the state of the art, and presumes no novelty nor lack thereof) to utilize all collected satellite data, properly identified and stored as a huge intercorrelated reference system—itself anchored by ground truth data—as a means to automatically geocode incoming raw pixels to the massive overall data set. The accuracy of this automated geocoding would hopefully be higher than that obtainable from ephemeris-type systems alone, but would probably be less accurate than “manually instigated” precision geocoding based directly on ground truth. The hope and goal would be that a lower core cost/meter geocoding accuracy could be achieved.
Such a system may involve the following elemental components:
1) An ideal sphere with an arbitrary time origin (as the starting point for the DEM model) 2) A time-evolving DEM 3) A time-evolving master-correlate albedo texture map
3A) A finite layered index map, organizing current raw data contributors to map
4) Ground Truth Data 5) Nominal ephemeris data per contiguous datastream
The ongoing automation process includes:
1) Creating initial sphere, DEM, and texture map using existing ground truth 2) Creating a layered index map 3) Each newly acquired datastream is cloud-masked, DEM-projection-and refraction-corrected 4) The masked-corrected data—using nominal ephemeris data as a starting point—is correlated to a master DEM/albedo map, itself projected along nominal ephemeris 5) The quality of the new data is evaluated, and incrementally added to the master albedo map and index map if it is deemed acceptable
5A) a pseudo infinite impulse response (based on time and quality of data) in coming up with current albedo map pixel value (omnidirectional pixel value)
At the core of building the albedo-map (and also the DEM) is the need to always track its inputs for several reasons:
redundant checking for accuracy and veracity of inputs; indexing of what data is contributing to the master albedo map; coordination of data from similar or even vastly different sources, all contributing to either the master maps or to existing relational databases.
As detailed below, watermarking can play an important role in the achieving these objects.
The foregoing will be clearer from the following.
Consider an illustrative DEM system with a 10 meter horizontal resolution, and featuring continual refresh and georeferencing. At two bytes per pixel, and a model size of 4M by 2M pixels, the model comprises 16 Terabytes of data. The albedo map is on the same order of resolution, with the same data storage requirements. The database storing this information desirably is arranged to easily graph necessary correlation scenes.
Presume an existing master DEM and albedo map. These may have been formed by a dozen or more redundant component data sets (e.g., aerial images, ground surveys), acquired over the previous days, months or years, that have been composited together to yield the final DEM/map (“model”).
Now imagine a new satellite image is acquired corresponding to part of the region represented by the master model. The particular terrain depicted by the satellite image can be inferred from ephemeris and other factors, as noted above. By such techniques, the location of the depicted image on the earth's surface (e.g., the latitude and longitude of a point at the center of the image) may be determined within an error of, say 5-500 meters. This is a gross geo-referencing operation.
Next a fine geo-referencing operation is automatically performed, as follows. An excerpt of the master model is retrieved from the database—large enough to encompass the new image and its possible placement error (e.g., an area centered on the same latitude/longitude, but extending 250 meters further at each edge). A projective image is formed from this master DEM/map excerpt, considering, e.g., the satellite's position and atmospheric effects, thereby simulating how the master model would look to the satellite, taking into account—where possible—the particular data represented by the satellite image, e.g., the frequency bands imaged, etc. (The albedo map may be back-projected on the 3D DEM data in some arrangements to augment the realism of the projective image.)
The projective image formed from the master DEM/map excerpt differs somewhat from the image actually acquired by the satellite. This difference is due, in part, to the error in the gross geo-referencing. (Other differences may arise, e.g., by physical changes in the region depicted since the master DEM/map was compiled.)
The projective image is next automatically correlated with the satellite image. A variety of known mathematical techniques can be utilized in this operation, including dot product computation, transforming to spatial frequency domain, convolution, etc. In a lay sense, the correlation can be imagined as sliding one map over the other until the best registration between the two images is obtained.
From the correlation operation, the center-to-center offset between the excerpt of the master DEM/map, and the satellite image, is determined. The satellite image can thereby be accurately placed in the context of the master model. Depending on system parameters, a fine placement accuracy of, e.g., between 5 cm and 5 meters (i.e., sub-pixel accuracy) may be achieved.
(In some embodiments, affine transformations can be applied to the satellite data to further enhance the correlation. E.g., particular geological or other features in the two data sets can be identified, and the satellite data (e.g., map or image) can then be affine-transformed so that these features correctly register.)
With the satellite image thus finely geo-referenced to the master DEM/map, it can be transformed (e.g., resampled) as necessary to correspond to the (typically rectilinear) reference system used in the master model, and then used to refine the data represented in the model. Buildings or other features newly depicted in the satellite image, for example, can be newly represented in the master model. The master model can be similarly updated to account for erosion and other topological changes revealed by the new satellite image.
Part of the finely geo-referenced satellite data may be discarded and not added to the master model, e.g., due to cloud cover or other obscuring phenomena. The remaining data is assessed for its relative quality, and this assessment is used in determining the relative weight that will be given the new satellite data in updating the master model.
In one embodiment, the finely geo-referenced satellite data is segmented into regions, e.g., rectangular patches corresponding to terrain 1000 meters on a side, and each patch is given its own weighting factor, etc. In a system with 10 meter resolution (i.e., a pixel size of 10 m 2 , the patch thus comprises an array of 100×100 pixels. (In some embodiments, the fine geo-referencing is done following the segmentation of the image, with each patch separately correlated with a corresponding area in the master model.) Each patch may take the form of a separate data file.
When the new satellite data is added to update the master model, old data may be discarded so that it no longer influences the model. Consider an area that is imaged monthly by a satellite. Several months' worth of image data may be composited to yield the master model (e.g., so cloud cover that obscured a region in the latest fly-over does not leave part of the model undefined). As each component image data gets older, it may be given less and less weight, until it no longer forms any part of the master model. (Other component data, in contrast, may be retained for much longer periods of time. Map information collected by ground surveys or other forms of “ground truth” information may fall into this category.)
The master model may be physically maintained in different ways. In one exemplary arrangement, a database stores the ten sets of data (e.g., acquired from different sources, or at different times) for each 1000×1000 meter patch. When interrogated to produce a map or other data, the database recalls the 10 data sets for each patch, and combines them on the fly according to associated weighting factors and other criteria (e.g., viewing angle) to yield a net representation for that patch. This composite patch is then combined (e.g., graphically stitched) with other adjoining, similarly-formed composite patches, to yield a data set representing the desired area.
In another embodiment, the component sets of image data are not separately maintained. Rather, each new set of image data is used to update a stored model. If the new image data is of high quality (e.g., good atmospheric seeing conditions, and acquired with a high resolution imaging device), then the new data may be combined with the existing model with a 20/80 weighting (i.e., the existing model is given a weight four-times that of the new data). If the new image data is of low quality, it may be combined with the existing model with a 5/95 weighting. The revised model is then stored, and the new data needn't thereafter be tracked.
(The foregoing examples are gross simplifications, but serve to illustrate a range of approaches.)
The former arrangement—with the component data stored—is preferred for many applications, since the database can be queried to yield different information. For example, the database can be queried to generate a synthesized image of terrain as it would look at a particular time of day, imaged in a specified IR frequency band, from a specified vantage point.
It will be recognized that a key requirement—especially of the former arrangement—is a sophisticated data management system. For each data set representing a component 1000×1000 meter patch stored in the database, a large quantity of ancillary data (meta data) must be tracked. Among this meta data may be a weighting factor (e.g., based on seeing conditions and sensor attributes), an acquisition date and time (from which an age-based weighting factor may be determined), the ID of the sensor/satellite that acquired that data, ephemeris data from the time of acquisition, the frequency band imaged, the geo-referenced position of the patch (e.g., latitude/longitude), etc., etc. (Much of this Data May be Common to all Patches from a Single Image.)
Classically, each component source of data to the system (here referred to as an “image” for expository convenience) is associated with a unique identifier. Tapes and data files, for example, may have headers in which this identifier is stored. The header may also include all of the meta data that is to be associated with that file. Or the identifier can identify a particular database record at which the corresponding meta data is stored. Or hybrid approaches can be used (e.g., the header can include a file identifier that identifies a data base record, but also includes data specifying the date/time of data acquisition).
In the final analysis, any form of very reliable image identification may suffice for use in such a system. The header approach just-discussed is straightforward. Preferable, however, is to embed one or more identifiers directly into the image data itself (i.e., “in band” steganographic encoding using digital watermarking). A well-designed watermarking name-space can in fact become a supra-structure over several essentially independent serial numbering systems already in use across a range of satellite sources. Moreover, rudimentary georeferencing information can actually be embedded within the watermark name-space.
For example, on initial acquisition, an initial watermark can be applied to satellite imagery detailing the ephemeris based gross georeferencing. Once the image has been finely georeferenced, the existing watermark can either be overlaid or overwritten with a new watermark containing the georeferencing information (e.g., “center lat: N34.432-4352, long: W87.2883134; rot from N/S: 3.232; x2.343, y2.340, dx0.123, dy493, etc.”). These numbers essentially encode georeferencing info including projective and atmospheric distortions, such that when this image is DEM-projection corrected, high accuracy should be achieved.
Another way to explain the need for watermarking might be the following: Pity the first grade teacher who has a class of young upstarts who demand a lengthy dissertation on why they should simply put their names on their papers. The uses defy even common sense arguments, and it is no different with watermarks . . . sear in a serial number and just keep track of it.
The assignee's U.S. Pat. No. 6,122,403, and pending application Ser. No. 09/503,881, detail suitable digital watermarking techniques in which values of pixels, e.g., in a 100×100 pixel patch, can be slightly altered so as to convey a plural-bit payload, without impairing use of the pixel data for its intended purpose. The payload may be on the order of 50-250 bits, depending on the particular form of encoding (e.g., convolution, turbo, or BCH coding can be employed to provide some error-correcting capability), and the number of bits per pixel. Larger payloads can be conveyed through larger image patches. (Larger payloads can also be conveyed by encoding the information is a less robust fashion, or by making the encoding more relatively visible.)
The watermark payload can convey an image identifier, and may convey other meta data as well. In some systems, the component image files are tagged both by digital watermark identifiers and also by conventional out-of-band techniques, such as header data, thereby affording data redundancy.
Watermarking may be performed in stages, at different times. For example, an identifier can be watermarked into an image relatively early in the process, and other information (such as finely geo-referenced latitude/longitude) can be watermarked later. A single watermark can be used, with different payload bits written at different times. (In watermark systems employing pseudo-random data or noise (PN), e.g., to randomize some aspect of the payload's encoding, the same PN data can be used at both times, with different payload bits encoded at the different times.)
Alternatively, different watermarks can be applied to convey different data. The watermarks can be of the same general type (e.g., PN based, but using different PN data). Or different forms of watermark can be used (e.g., one that encodes by adding an overlay signal to a representation of the image in the pixel domain, another that encodes by slightly altering DCT coefficients corresponding to the image in a spatial frequency domain, and another that encodes by slightly altering wavelet coefficients corresponding to the image).
In some multiple-watermarking approaches, a first watermark is applied before the satellite image is segmented into patches. A later watermark can be applied after segmentation. (The former watermark is typically designed so as to be detectable from even small excerpts of the original image.)
A watermark can be applied by the imaging instrument. In some embodiments, the image is acquired through an LCD optical shutter, or other programmable optical device, that imparts an inconspicuous patterning to the image as it is captured. (One particular optical technique for watermark encoding is detailed in U.S. Pat. No. 5,930,369.) Or the watermarking can be effected by systems in the satellite that process the acquired data prior to transmission to a ground station. In some systems, the image data is compressed for transmission—discarding information that is not important. The compression algorithm can discard information in a manner calculated so that the remaining data is thereby encoded with a watermark.
The ground station receiving the satellite transmission can likewise apply a watermark to the image data. So can each subsequent system through which the data passes.
As indicated, the watermark(s) can identify the imaging system, the date/time of data acquisition, satellite ephemeris data, the identity of intervening systems through which the data passed, etc. One or more watermarks can stamp the image with unique identifiers used in subsequent management of the image data, or in management of meta data associated with the image.
A watermark can also serve a function akin to a hyperlink, e.g., as detailed in application Ser. No. 09/571,422. For example, a user terminal can permit an operator to right-click on a region of interest in a displayed image. In response, the system can respond with a menu of options—one of which is Link Through Watermark(s). If the user selects this option, a watermark detection function is invoked that decodes a watermark payload from the displayed image (or from a portion of the image in which the operator clicked). Using data from the decoded watermark payload, the terminal interrogates a database for a corresponding record. That record can return to the terminal certain stored information relating to the displayed image. For example, the database can present on the terminal screen a listing of hyperlinks leading to other images depicting the same area. By clicking on such a link, the corresponding image is displayed. Or the database can present, on the user terminal screen, the meta-data associated with the image.
In some embodiments, watermarks in component images may carry-through into the master DEM/map representation. If an excerpt of the master DEM/map is displayed, the user may invoke the Link Through Watermark(s) function. Corresponding options may be presented. For example, the user may be given the option of viewing each of the component images/data sets that contributed to the portion of the master model being viewed.
(It will be recognized that a variety of user interface techniques other than right-clicking, and selecting from a menu of options thereby displayed, can be employed. That interface is illustrative only.)
In some embodiments, a watermark can be applied to each DEM/map from the master database as it is retrieved and output to the user. The watermark can indicate (i.e., by direct encoding, or by pointing to a database record) certain data related to the compiled data set, such as the date/time of creation, the ID of the person who queried the database, the component datasets used in preparing the output data, the database used in compiling the output data, etc. Thereafter, if this output data is printed, or stored for later use, the watermark persists, permitting this information to be later ascertained.
Watermarks can be applied to any data set (e.g., a satellite image, or a map generated from the master database) for forensic tracking purposes. This is particularly useful where several copies of the same data set are distributed through different channels (e.g., provided to different users). Each can be “serialized” with a different identifier, and a record can be kept of which numbered data set was provided to which distribution channel. Thereafter, if one of the data sets appears in an unexpected context, it can be tracked back to the distribution channel from which it originated.
Some watermarks used in the foregoing embodiments can be “fragile.” That is, they can be designed to be lost, or to degrade predictably, when the data set into which it is embedded is processed in some manner. Thus, for example, a fragile watermark may be designed so that if an image is JPEG compressed and then decompressed, the watermark is lost. Or if the image is printed, and subsequently scanned back into digital form, the watermark is corrupted in a foreseeable way. (Fragile watermark technology is disclosed, e.g., in application Ser. Nos. 09/234,780, 09/433,104, 09/498,223, 60/198,138, 09/562,516, 09/567,405, 09/625,577, 09/645,779, and 60/232,163.) By such arrangements it is possible to infer how a data set has been processed by the attributes of a fragile watermark embedded in the original data set.
Assuming that early testing proves out that the addition of “watermarking energy” into the normal workflow of satellite imaging systems does not materially disturb the function of most of the output of that system, nevertheless certain “watermark removal” tools can be built to alleviate any problems in cases where unacceptable impact is identified. This can either be a generic tool or one highly specialized to the particular application at hand (perhaps employing secret data associated with that application). In a second generation system (without too much fanfare) a fairly simple “remove watermark before analyzing this scene” function could be automatically included within analysis software such that 99% of image analysts wouldn't know or care about the watermarking on/off/on/off functionality as a function of use/transport.
As will be apparent, the technology detailed herein may be employed in reconnaissance and remote sensing systems, as well as in applications such as guidance of piloted or remotely piloted vehicles.
To provide a comprehensive disclosure without unduly lengthening this specification, applicant incorporates by reference, in their entireties, the disclosures of the above-cited patents and applications.
It should be understood that the technology detailed herein can be applied in the applications detailed in the cited DEM patents, as well as in other mapping and image (or audio or video or other content) asset management contexts (Likewise, the technologies detailed in the cited patents can be advantageously used in embodiments according to the present invention.)
While particular reference was made to Digital Elevation Models and albedo maps, the same principles are likewise applicable to other forms of maps, e.g., vegetative, population, thermal, etc., etc.
While the illustrated embodiment correlated the incoming imagery with a projective image based on the master DEM/map, in other embodiments a reference other than the master DEM/map may be used. For example, a projection based just on part of the historical data from which the DEM/map was compiled can be used (e.g., one or more component data sets that are regarded as having the highest accuracy, such as based directly on ground truths).
Although not belabored, artisans will understand that the systems described above can be implemented using a variety of hardware and software systems. One embodiment employs a computer or workstation with a large disk library, and capable database software (such as is available from Microsoft, Oracle, etc.). The registration, watermarking, and other operations can be performed in accordance with software instructions stored in the disk library or on other storage media, and executed by a processor in the computer as needed. (Alternatively, dedicated hardware, or programmable logic circuits, can be employed for such operations.)
Certain of the techniques detailed above find far application beyond the context in which they are illustrated. For example, equipping an imaging instrument with an optical shutter that impart a watermark to an image finds application in digital cinema (e.g., in watermarking a theatrical movie with information indicating the theatre, date, time, and auditorium of screening).
In view of the wide variety of embodiments to which the principles and features discussed above can be applied, it should be apparent that the detailed embodiments are illustrative only and should not be taken as limiting the scope of the invention. Rather, I claim as my invention all such modifications as may come within the scope and spirit of the following claims and equivalents thereof. (For expository convenience, the term “map” as used in the claim should be construed to encompass terrain models, such as DEMs.)
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Digital watermarking technology is used in conjunction with video captured from airborne platforms (e.g., satellites, remotely controlled aerial vehicles and aircraft). One claim recites an airborne platform comprising: a camera for capturing video depicting at least a portion of the earth's surface; and an electronic processor. The electronic processor is programmed for: obtaining geographical metadata associated with captured video; encoding first digital watermarking in the captured video through alterations to data representing the captured video, in which the first digital watermarking is generally imperceptible to a human observer of the captured video when rendered to the human observer in real time, and in which the first digital watermarking comprises or links to the geographical metadata; and controlling transmission of digital watermarked video to a remotely located receiver on or in the earth's surface. Another claim recites: that the electronic processor is further programmed for: hiding second digital watermarking in data representing the captured video, the second digital watermarking comprising a plural-bit payload that includes data representing a refinement relative to at least some of the geographical metadata. Other claims and combinations are provided too.
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OBJECT OF THE INVENTION
[0001] The present invention relates to a constructive assembly for building walls which allow forming wall coverings. Examples of coverings that can be formed with the present invention are façades, party walls and partition walls.
[0002] The constructive assembly is characterized by being formed by a plurality of cables intended for being arranged under stress in the vertical position, and a plurality of blocks having coupling means for coupling them to the cables such that integral joining is assured, forming the wall.
[0003] Walls thus formed do not require the use of mortar or the need to be built by skilled labor, making it possible to build reformed or new exposed faces more easily and in a cleaner and faster manner and, in the case of thin material (tiles), with the certainty that such material will not become detached.
BACKGROUND OF THE INVENTION
[0004] The shortage of skilled labor in placing certain construction materials makes the overall amount for installing such works more expensive, making the placement of such materials in some circumstances unfeasible. A wall made from top-quality materials will often produce a terrible result if it is not done by professionals who obtain the right finish.
[0005] These results that do not comply with the established requirements can be merely aesthetic (for example, in exposed brick façades) or functional (as in the case of installing sound insulation or thermal insulation), with regulatory impositions that must be complied with.
[0006] Particular constructive quality problems in walls include the lack of flatness in the built surface and the presence of stains due to poor building and/or inexistent or substandard cleaning.
[0007] The high quality requirements demanded in the work not only on the supplied material level but also on the finished final element level lead to developing products that allow limiting, to the extent possible, poor practices that can occur in installation, such that the smallest number of variables possible is left for the installer to decide.
[0008] Awareness of environmental pollution, higher demands for comfort, economic studies conducted and other factors have resulted in an increase in regulatory demands as regards sound and thermal insulation in construction. This has caused a thorough revision in constructive systems used up until now.
[0009] The present invention is particularly useful in reforming homes with rather thin parts (tiles) because it enables placement ease and reasonableness, and most importantly it eliminates the risk of parts peeling off and detaching.
DESCRIPTION OF THE INVENTION
[0010] The present invention solves the problems identified above by means of using a constructive assembly which is configured to not require the use of mortar and which, as it is very simple to build, gives rise to a defect-free wall with a very high quality finish.
[0011] The terms horizontal and vertical will be used throughout the description, these terms being, in the context of the invention, absolute and non-relative terms because the term vertical must be interpreted as being oriented or distributed according to the direction of gravity (Z) and horizontal must be interpreted as being the direction perpendicular to the vertical.
[0012] The constructive assembly for building walls according to the invention allows generating or covering a surface extending between a lower bearing member and an upper bearing member located above it. The lower bearing member is the support for the wall because it receives the wall's weight. A typical embodiment of the invention consists of a wall extending on a lower bearing member formed by the floor reaching the upper bearing member formed by the ceiling. Both the floor and the ceiling give rise to horizontal planes between which the wall is located.
[0013] The constructive assembly comprises:
a plurality of sections of cable with fixing means at the ends thereof adapted to be fixed tautly between the lower bearing member and the upper bearing member, distributed according to a directrix path in the lower bearing member (P) and the upper bearing member (T). Each of the sections of cable with fixing means at the ends thereof is intended for being fixed tautly between the lower bearing member and the upper bearing member. In the operative position, when the wall is in the process of being built and once it is built, the sections of cable are arranged according to a vertical direction. Tautness is obtained by the fixing means located at the ends thereof, one end being fixed to the lower bearing member and the other end being fixed to the upper bearing member. The vertical projection of the upper bearing member does not necessarily have to coincide with the lower bearing member, as long as it is above the latter and allows the fixing means for fixing the upper ends of the sections of cable to be located in such a position that it allows obtaining the tautness and vertical orientation of said sections of cable. This is the case in which the lower bearing member is formed by a horizontal floor, for example, on which the wall is erected, and the upper bearing member is a cantilevered element on the edge of which the upper ends of the cables are fixed such that said cables are vertical. The sections of cable are distributed according to a directrix path F. This directrix path is the same in the lower bearing member and in the upper bearing member. The directrix path is usually a straight line giving way to planar walls. In these cases, the directrix path coincides with the intersection between a plane parallel to the generated wall and the horizontal support plane located on the lower bearing member. This same directrix is the path along which the upper ends of the sections of cable are distributed in the fixing thereof to the upper bearing member. This path can be curved and will give rise to a surface formed by the wall that is also curved. The surface of the wall once it is built will be a ruled surface with parallel upper and lower directrix paths ┌ and with vertical straight generatrices. It is also possible to carry out the invention with upper and lower bearing members in sections. One embodiment in which the upper and lower bearing members are distributed in sections is that wall located on a floor in the form of steps or planes at different heights, a ceiling in the form of steps or planes at different heights, or one in which both the floor and ceiling are formed by stepped planes located at different heights. According to one embodiment of the invention, the sections of cable with fixing means at the ends thereof are partial sections of a single cable forming a zigzag configuration. One end of the cable is fixed to either the lower bearing member or upper bearing member and extends vertically to the opposite bearing member where there is arranged a pulley or tension element that allows changing the direction of the cable. It extends from this element for changing the direction to the next one horizontally, and from there it extends vertically giving rise to the second vertical section of cable. This zigzag configuration alternates vertical sections of cable extending between the lower bearing member and the upper bearing member, and horizontal sections of cable connecting a vertically oriented section of cable and the next one. The final end of the cable is the one fixed to the upper or lower bearing member assuring the tension of all the intermediate sections of cable. The tension generated by fixing the two ends of cable is transmitted to the remaining intermediate sections of cable as a result of the intermediate means for changing the direction. According to one embodiment, the fixing means or the means for changing the direction securing the position of the ends of the vertical sections of cable are one-piece components. This embodiment has the advantage that it is not necessary to measure and position each of the fixing means on site, but that by positioning one-piece components both above and below the fixing means are properly distributed along the directrix path. According to another embodiment, this one-piece component has a specific length such that walls of greater horizontal length make use of more than one one-piece component in both the lower bearing member and upper bearing member. a plurality of building blocks having an essentially prismatic body where each building block comprises at least:
a first support base configured for resting on the lower bearing member or on at least another building block, a second base arranged on the face opposite the first base configured for supporting at least another building block, an exposed surface extending between the first base and second base, an anchoring surface extending between the first base and second base arranged on the face opposite the exposed surface,
wherein the anchoring surface of the building blocks comprise anchoring means for the anchoring thereof to sections of cables for stabilizing the wall.
Once the sections of cable are fixed and distributed along the directrix curve, wall construction progresses by placing the building blocks having a prismatic body in rows from bottom to top. The rows follow the path imposed by the directrix path. Each of the building blocks has two bases, the first lower support base resting its weight either on the lower bearing member if it is the first row or on the row of building blocks of the lower row if it is not the first row. The upper base is the base which is in turn arranged to act as a support for the row located immediately thereabove. The support can be direct by supporting a building block on lower building blocks, or it can be indirect by means of parts generating a gap or distance between building blocks. Examples of intermediate parts which generate a gap and can have elements with additional functions will be described in the detailed description of the invention. The building block also has an exposed face extending between the first base and second base. This face will usually be vertical and generates the exposed surface of the wall that is built. Opposite this face is the anchoring surface. This anchoring surface has anchoring means adapted for anchoring sections of cables to stabilize the construction. In other words, the building blocks are not simply supported, distributed in rows, but rather the non-exposed face is anchored to the cables. The distribution of the sections of cable must correspond with the position of the anchoring means of the building blocks such that when the building blocks are placed in rows, each of the anchoring means of these building blocks coincide with a section of cable according to the vertical projection.
[0033] In the context of the invention, the anchoring which has been obtained is of particular interest out of the different anchoring means with a cable due to the shape of the anchoring surface of the building block.
[0034] Before defining this particular way of anchoring, two directions which will be used throughout the description are defined.
[0035] The horizontal direction X is defined as the direction tangent to the directrix path ┌. If the directrix path ┌ is straight, the wall that is built will be planar. In this case, the horizontal direction X is the horizontal straight line resulting from the intersection between the vertical plane of the wall that is built and the horizontal plane.
[0036] The transverse direction Y is defined as the horizontal direction that is perpendicular to both the direction of gravity (Z) and the horizontal direction X. In the particular case of a planar wall this direction is the direction perpendicular to said wall.
[0037] Having defined these directions, these are the directions that will be taken as a reference on a building block considering that said building block is oriented according to its operative position in the wall. In other words, although the building block is an independent part, the vertical direction will be taken to be the direction in which the first base and second base are spaced from one another, direction X will be taken to be the direction along which the building block is oriented to be distributed in rows, and the transverse direction Y will be taken to be the direction giving rise to the spacing between the exposed face and the face where the anchoring means are located.
[0038] Also by applying these orientation references to the block as if it were in the operative mode on the wall, the horizontal direction X and transverse direction Y are the directions defining the support plane for the first base and second base.
[0039] After having established these references on the building block, the anchoring means of the building block according to a preferred example of the invention is by means of a recess penetrating the anchoring surface adapted for receiving at least one of the sections of cable.
[0040] The recess is such that in the plan projection on a plane parallel to the plane formed by the horizontal direction X and the transverse direction Y, this recess additionally shows a protuberance projecting in the horizontal direction X, this protuberance being configured for retaining at least one section of cable according to direction Y. The section of cable is housed in this recess.
[0041] The manner of obtaining this recess with the retaining protuberance is not unique. Examples of configurations of recesses with a protuberance are the dovetails. Dovetail is a recess having two protuberances oriented opposite one another according to the horizontal direction X; that is, facing to one another.
[0042] The term “half-dovetail” will also be used. In the context of the invention, half-dovetail will be understood as that recess in which there is only one protuberance oriented in the recess according to direction X. Dovetail can be interpreted to mean two half-dovetails forming a single recess and with the protuberances of both half-dovetails facing one another.
[0043] When one and the same building block has two anchoring means with protuberances oriented opposite one another either in the same recess or in different recesses, the two sections of cable intended for entering and being anchored with a block must be forced, moving them according to direction X. The movement is one that brings them closer. This movement bringing them closer is possible, even if the sections of cable are under stress, especially when building the wall as a result of part of the length of the sections of cable still being free. As the height of the wall progresses, the free sections of cable are shorter and shorter, making it harder to move them in direction X or “clamping them”. According to one embodiment, the use of blocks in which recesses with protuberance have said protuberances oriented in a single direction following transverse direction Y is suitable for the final rows. This configuration allows placing the building block with two movements, a first movement for insertion in transverse direction Y, making the sections of cable enter the recesses, and a second lateral movement according to direction X so that the protuberance prevents the building block from coming out according to direction Y.
[0044] Building blocks configured as tiles are of particular interest.
[0045] A set of drawings will be used to describe embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
[0046] These and other features and advantages of the invention will be better understood based on the following detailed description of a preferred embodiment, given solely by way of illustrative and non-limiting example in reference to the attached drawings.
[0047] FIG. 1 This figure schematically shows the most relevant elements of the invention that allow securing the building blocks as well as a schematic depiction of a building block for building a wall.
[0048] FIG. 2A, 2B These figures show embodiments of anchoring parts for anchoring the ends of sections of cable giving rise to a pre-established distribution along the directrix path r, in this case straight.
[0049] FIGS. 3A-3D These figures show the use of embodiments of anchoring parts like those shown in FIGS. 2A and 2B with the sections of cable installed and under stress.
[0050] FIG. 4 This figure shows four examples of building blocks configured as tiles where the separation between the exposed surface and the anchoring surface is very small. The different examples show different heights of the tile.
[0051] FIG. 5 This figure shows a plan view, from top to bottom, according to the orientation of the page, of a sequence of a) a building block with the sections of cable introduced in the anchoring means; b) two adjacent building blocks with the sections of cable introduced like; and c) the two previous blocks with a third superimposed block to show how the superimposition blocks lateral movement of the section of cable, stabilizing the construction.
[0052] FIG. 6 This figure shows the same sequence but with the area of one of the cables enlarged.
[0053] FIG. 7 This figure shows a plan view, from top to bottom, according to the orientation of the page, of a sequence for insertion of sections of cable in another example of tile-type building block with a very stable configuration of the anchoring means.
[0054] FIGS. 8A, 8B FIG. 8A shows two different perspective views of the configuration of a tile-type building block, and FIG. 8B shows a sequence for insertion of the sections of cable for the fixing thereof.
[0055] FIGS. 9A, 9B FIG. 9A shows two different perspective views of the configuration of a tile-type building block having a horizontal configuration or a configuration narrow in height, and FIG. 9B shows two different perspective views of the configuration of a tile-type building block having a vertical configuration or a configuration narrow in width.
[0056] FIGS. 10A, 11A FIG. 10A shows a sequence like that shown in FIG. 5 using another example of a configuration for a tile-type building block, and FIG. 11A shows the same sequence but with the area of two of the cables enlarged.
[0057] FIGS. 10B, 11B FIG. 10B shows a sequence like the one shown in FIG. 10A using another example of a configuration for a tile-type building block in which the recesses are oriented in the opposite direction and there are recesses at the ends of each part. FIG. 11B shows the same sequence but with the area of two of the cables enlarged.
[0058] FIG. 12A, 12B These figures show perspective views of building blocks of three different rows corresponding to the examples shown in FIGS. 10A, 11A, 10B and 11B , respectively, including spacers defining a pre-established gap.
[0059] FIG. 13 This figure shows a perspective view of a lower fixing part with the sections of cable departing upwardly from same, as well as building blocks according to another embodiment forming the first and second row.
[0060] FIG. 14 This figure shows various examples of parts that allow finishing the corner where two wall planes converge according to an embodiment of the invention.
[0061] FIG. 15 This figure shows a retaining element that can be housed in a recess of the building blocks to secure the position of the section of cable without it coming out of said recess.
[0062] FIG. 16 This figure shows a perspective view equivalent to the perspective view of FIG. 13 where the sections of cable are secured with a part like that shown in the preceding drawing.
[0063] FIG. 17 This figure shows a perspective view of a spacing part also incorporating a portion that can be housed in the recess for maintaining the separation between sections of cable.
[0064] FIG. 18 This figure shows another embodiment different from that shown in the preceding drawing.
[0065] FIG. 19 This figure shows another embodiment different from that shown in the preceding drawing furthermore incorporating a vertical spacer for generating vertical gaps between consecutively arranged building blocks.
[0066] FIG. 20 This figure shows a perspective view of another embodiment of the spacer keeping two consecutive sections of cable spaced from one another.
[0067] FIG. 21 This figure shows a perspective view of other embodiments of the spacer keeping a plurality of sections of cable covering the horizontal gap between rows of building blocks spaced from one another. One embodiment includes a vertical spacer between building blocks.
[0068] FIG. 22 This figure shows a perspective view of the use of an embodiment of the spacer for sections of cable when it is arranged between consecutive rows of building blocks.
[0069] FIG. 23 This figure shows a retaining anchor for establishing a structural link between the wall according to an embodiment of the invention and a structure such as a wall spaced from the former.
[0070] FIG. 24 This figure shows a plan view of two examples of fixing means for fixing a retaining anchor when it is already housed in the recess of the building block.
[0071] FIG. 25 This figure shows a perspective view of the construction of the two first rows of a wall according to an embodiment of the invention showing a retaining anchor in the rear part.
[0072] FIG. 26 This figure shows an embodiment of a retaining anchor the fixing means of which further comprising elements working as spacers configured for being housed in a recess.
[0073] FIG. 27 This figure shows the configuration of a building block having in its bases a recess and a longitudinal protrusion arranged for allowing coupling in stacking, improving stability of the wall that is built and with a dovetail coupling in the heads.
[0074] FIG. 28 This figure shows another embodiment of a building block, with the housings for confining the cables.
[0075] FIG. 29 This figure shows another embodiment where the anchoring means allow two sections of cables per recess.
[0076] FIG. 30 This figure shows the same building block as in the preceding example as well as a spacing element adapted for maintaining the separation between pairs of sections of cable, for serving as a gap spacer and for acting as permanent formwork for subsequent filling with mortar, insulation and other materials.
DETAILED DESCRIPTION OF THE INVENTION
[0077] According to the first inventive aspect, the present invention is a constructive assembly for building walls where the wall that is built can be a wall giving rise to a constructive spacing element or giving rise to an element for covering another wall, for example for obtaining a finish in a specific space.
[0078] FIG. 1 schematically shows a lower bearing member (P) configured as a base, for example a section of floor. An upper bearing member (T) configured as an upper base, for example a section of ceiling, is also schematically shown in the upper part. A plurality of sections of cable ( 1 ) under stress extend between the lower bearing member (P) and the upper bearing member (T) as a result of fixing means ( 1 . 1 ) arranged at each of the ends of the sections of cable ( 1 ) which are fixed to the lower bearing member (P) and to the upper bearing member (T), respectively.
[0079] The upper and lower fixing means ( 1 . 1 ) corresponding to one and the same section of cable ( 1 ) coincide according to the vertical projection Z, where said vertical direction Z is defined by the direction of the force of gravity {right arrow over (g)}. Therefore, the sections of cable ( 1 ) are also oriented vertically.
[0080] The sections of cable ( 1 ) are distributed along a directrix path (┌) which is reproduced both on the lower bearing member (P) and on the lower surface of the upper bearing member (T).
[0081] Once the building blocks ( 2 ) are installed in the sections of cable ( 1 ) shown in this FIG. 1 , a wall following the configuration imposed by the directrix path (┌), in this case according to a curve, will be obtained.
[0082] In one embodiment, the operator responsible for fixing each of the sections of cable ( 1 ) can perform the measurement and positioning of the fixing means ( 1 . 1 ) for fixing the sections of cable ( 1 ) one by one. According to another embodiment, the use of a part which has more than one fixing means ( 1 . 1 ) allows arranging a plurality of properly positioned fixing means. FIG. 2A shows three L-profiles which in turn have perforations as fixing means ( 1 . 1 . 2 ) for fixing thereof to a wall to be covered with a wall according to one embodiment of the invention, and perforations or slots ( 1 . 1 . 1 ) for the passage of the ends of the sections of cable ( 1 ) which allow fixing the ends thereof. The position of the perforations or slots ( 1 . 1 . 1 ) determines the correct spacing and spatial distribution for the sections of cable ( 1 ).
[0083] This same FIG. 1 schematically shows a building block ( 2 ) comprising at least:
a first support base ( 2 . 1 ) configured for resting on the lower bearing member (P) or on at least another building block ( 2 ) and located in the lower non-exposed part; a second base ( 2 . 2 ) arranged on the face opposite the first base ( 2 . 1 ) configured for supporting at least another building block ( 2 ) and positioned in the upper part according to the orientation of the drawing; an exposed surface ( 2 . 3 ) extending between the first base ( 2 . 1 ) and second base ( 2 . 2 ); and an anchoring surface ( 2 . 4 ) extending between the first base ( 2 . 1 ) and second base ( 2 . 2 ) arranged on the face opposite the exposed surface ( 2 . 3 ).
[0088] The anchoring means ( 2 . 5 ) are located on the anchoring surface ( 2 . 4 ). The anchoring means ( 2 . 5 ) in the building block ( 2 ) shown in FIG. 1 are configured as a recess which in plan view shows an L-shaped configuration suitable for the entrance of the section of cable ( 1 ) and for retaining said section of cable ( 1 ) therein.
[0089] The drawing shows an enlargement of the building block ( 2 ), and the arrow shows the direction for moving said block closer to the lower part of one of the sections of cable ( 1 ) according to direction Y.
[0090] FIG. 2B shows another profile with two parallel flanges, where both parallel flanges comprise perforations or slots ( 1 . 1 . 1 ).
[0091] FIGS. 3A-D show perspective views of profiles ( 1 . 1 ) like those shown in FIGS. 2A-2B , spaced from one another and with the sections of cables ( 1 ) positioned between both profiles. The lower profile ( 1 . 1 ) will be fixed to a lower bearing member (P) and the upper profile ( 1 . 1 ) will be fixed to an upper bearing member (T). Not all the perforations or slots ( 1 . 1 . 1 ) that are available have to be used. Use will depend on the type of building block ( 2 ) used. One and the same profile ( 1 . 1 ) can have a valid configuration for several configurations of building blocks ( 2 ).
[0092] FIG. 3D shows an embodiment in which there are two sections of cable ( 1 ) in one and the same position according to the directrix path (┌), which is straight in this case. This configuration increases stability of the wall that is built and is suitable for building blocks ( 2 ) having anchoring means ( 2 . 5 ) suitable for two sections of cable ( 1 ) simultaneously. Examples of building blocks ( 2 ) allowing two sections of cable ( 1 ) will be described below when FIGS. 29 and 30 are described.
[0093] FIG. 4 shows a particular configuration of a building block ( 2 ) configured as a tile. The drawing shows tiles of different heights. The exposed face ( 2 . 3 ) is smooth, and the first ( 2 . 1 ) and second ( 2 . 2 ) bases are very narrow because the distance between the exposed face ( 2 . 3 ) and the anchoring surface ( 2 . 4 ) is narrow compared with the remaining dimensions of the building block ( 2 ).
[0094] The anchoring surface ( 2 . 4 ) has a configuration incorporating dovetail-shaped recesses ( 2 . 4 . 1 ). These dovetail-shaped recesses ( 2 . 4 . 1 ) are recesses having two protuberances ( 2 . 4 . 1 . 1 ) opposite one another according to the orientation of the side faces in an oblique plane oriented towards the inside of said recess ( 2 . 4 . 1 ). The dovetail or half-dovetail configuration is an alternative for the anchoring means ( 2 . 5 ).
[0095] FIGS. 5 and 6 show another alternative configuration of the recess ( 2 . 4 . 1 ) and protuberance ( 2 . 4 . 1 . 1 ) intended for preventing the section of cable ( 1 ) from coming out. FIG. 6 shows direction X and transverse direction Y with respect to the block ( 2 ) with the understanding that the building block ( 2 ) will be positioned and oriented following the direction that is tangential to the directrix path (┌), and therefore such directions can be taken to be directions with respect to the building block ( 2 ).
[0096] FIG. 5 shows a sequence of three graphical depictions arranged from top to bottom. The first graphical depiction shows a building block ( 2 ) where the alternative configuration for the recess ( 2 . 4 . 1 . 1 ) and protuberance ( 2 . 4 . 1 . 1 ) intended for preventing the section of cable ( 1 ) from coming out is configured according to an L-shape.
[0097] The second row shows two consecutive blocks ( 2 ) with sections of cable ( 1 ) positioned in the anchoring means ( 2 . 5 ), i.e., at the end of the L-shaped recess ( 2 . 4 . 1 ).
[0098] The third row in FIG. 5 shows the same row of blocks ( 2 ) superimposing another building block ( 2 ) in a staggered pattern. In other words, the third building block ( 2 ) is supported in two adjacent halves of a block ( 2 ) located thereunder.
[0099] Each building block ( 2 ) has two L-shaped recesses ( 2 . 4 . 1 ) although the L-shaped configuration of each recess ( 2 . 4 . 1 ) is in opposition, i.e., they have a symmetrical configuration.
[0100] By superimposing a building block ( 2 ) in a staggered pattern, the section of cable ( 1 ) is housed in a recess ( 2 . 4 . 1 ) with the L shape oriented towards one side according to direction X and it is housed in another recess ( 2 . 4 . 1 ) with the L shape oriented towards the opposite side according to the same direction X, in recess ( 2 . 4 . 1 ) of the building block ( 2 ) arranged thereabove.
[0101] The enlargement shown in FIG. 6 allows seeing that the opposing orientations of both L-shaped recesses ( 2 . 4 . 1 ) trap the section of cable ( 1 ) as shown in the vertical projection Z or in plan view.
[0102] FIG. 7 shows another example of a building block ( 2 ) with two L-shaped recesses ( 2 . 4 . 1 ) opposite one another close to the side ends with respect to the view used in said FIG. 7 , but with the orientation opposite the orientation shown in FIGS. 5 and 6 . It additionally has a central recess ( 2 . 4 . 1 ) having two protuberances ( 2 . 4 . 1 . 1 ) opposite one another giving rise to a T-shaped recess. This configuration allows keeping the building block ( 2 ) secured by sections of cable ( 1 ) without needing the blocks ( 2 ) arranged adjacent to one another to laterally cooperate.
[0103] FIG. 7 shows a sequence, from top to bottom, of the entrance of sections of cable ( 1 ) in the recesses ( 2 . 4 . 1 ). The entrance of sections of cable ( 1 ) requires forcing the position of each section of cable ( 1 ) so that the building block ( 2 ) is positioned correctly on the wall and the sections of cable ( 1 ) are suitably housed at the end of each recess ( 2 . 4 . 1 ) behind the protuberance ( 2 . 4 . 1 . 1 ).
[0104] By way of example, two sections of cable ( 1 ) housed in the same central recess ( 2 . 4 . 1 ) are brought closer to one another by means of clamping. Although the sections of cable ( 1 ) are under stress, when the section of cable ( 1 ) is long lateral movement thereof is possible to allow the entrance of such building blocks ( 2 ) where there are protuberances opposite one another.
[0105] As construction of the wall progresses, the length of free sections of cable ( 1 ) between the last building block ( 2 ) and the upper end is increasingly shorter and it is more difficult to force lateral movement. One way to help in this deformation is by means of using tools which enhance the force applied on the section of cable, such as pliers.
[0106] Even with these tools, for the last rows of section of cable ( 1 ) it may not be enough to obtain sufficient deformation. FIGS. 8A and 8B show a configuration of a building block ( 2 ) which can be used in these last rows.
[0107] In the configuration shown in FIGS. 8A and 8B , the protuberances of each of the recesses ( 2 . 4 . 1 ) are oriented in the same direction according to direction X.
[0108] The sequence for the entrance of the sections of cable ( 1 ) in the building block ( 2 ) with this configuration is shown in FIG. 8B from top to bottom. In the first two images the building block ( 2 ) is brought closer to the sections of cable ( 1 ) with a movement according to direction Y until such sections of cable ( 1 ) have completely entered the cavity. In this position, the building block ( 2 ) is moved laterally according to direction X until the sections of cable ( 1 ) are located behind the protuberance ( 2 . 4 . 1 . 1 ), assuring retention.
[0109] This second lateral movement imposes an order in the construction of the wall. If, for example, building blocks ( 2 ) are being incorporated according to the positive direction X. The configuration of each “L” must be such that the following building block ( 2 ) will have to be inserted according to the transverse direction Y, slightly shifted according to the positive direction X (separated from the building block ( 2 ) that is already placed in the wall), and the second movement is according to the negative direction X to secure the building block ( 2 ) in the sections of cable ( 1 ) by means of the protuberances ( 2 . 4 . 1 . 1 ). This operation is possible for all building blocks ( 2 ) of the row except the last one, which will require a smaller block at the end corresponding to the positive direction X and an additional filler part if the gap that is left is to be covered.
[0110] This reasoning must be changed to the opposite direction if the orientation of the L-shaped recesses ( 2 . 4 . 1 ) is the opposite.
[0111] This configuration of building block ( 2 ) allows ending the construction of the wall in the final rows thereof if the upper bearing member (T) is to be reached.
[0112] FIGS. 9A and 9B show perspective views of two embodiments of building blocks ( 2 ) with recesses ( 2 . 4 . 1 ) having two dovetail-shaped protuberances ( 2 . 4 . 1 . 1 ) opposite one another. FIG. 9A corresponds to a building block ( 2 ) having a horizontal configuration once placed in the wall, and FIG. 9B corresponds to a building block ( 2 ) having a vertical configuration.
[0113] The same reasoning followed in the sequence of FIGS. 5 and 6 for showing how sections of cable ( 1 ) are being trapped by stacking in a staggered pattern is valid for the sequence of FIGS. 10A and 11A , where this sequence uses a building block ( 2 ) like the one shown in FIG. 7 . The advantage of this building block is that each building block ( 2 ) has a section of cable ( 1 ) blocked at the end thereof, resulting in a very stable wall.
[0114] FIG. 12A shows a perspective view of a portion of wall with the upper building block ( 2 ) being slightly raised. This figure shows the use of spacing elements ( 3 ) adapted for being located between two sections of cable ( 1 ) where in the operative mode such sections of cable ( 1 ) are supported opposite one another in the at least one recess ( 2 . 4 . 1 ). The spacer ( 3 ) is shown in further detail in FIG. 20 .
[0115] FIGS. 10B and 11B reproduce another example where the configuration of the building blocks ( 2 ) has L-shaped recesses ( 2 . 4 . 1 ) oriented in the opposite direction according to direction X. The result is the same, primarily when there is a stack comprising two or more rows, as shown in the detail of FIG. 11B and in the perspective view of FIG. 12B , given that from one row to the row immediately thereabove or therebelow, the orientation direction of the recess ( 2 . 4 . 1 ) is the opposite and the cable ( 1 ) also remains trapped.
[0116] In this embodiment, the spacing elements ( 3 ) are formed by a part in the form of a plate with two end grooves ( 3 . 1 ) opposite one another.
[0117] One groove ( 3 . 1 ) receives a section of cable ( 1 ) and the opposite groove receives another section of cable ( 1 ). This spacer ( 3 ) prevents the linking sections of cable ( 1 ) from moving closer to one another. In the case of the central recess ( 2 . 4 . 1 ) of the building block ( 2 ), this limitation means that it is not possible for the sections of cable ( 1 ) to come out of their housing.
[0118] Additionally, these spacers ( 3 ) also involve a gap or separation between rows of consecutive blocks. This gap allows the passage of air between blocks, favoring ventilation. Other configurations of spacers ( 3 ) cover the entire free space resulting from the gap or separation such that the gap is shown covered.
[0119] FIG. 13 shows an embodiment of the invention where the building blocks ( 2 ) are configured with multiple dovetail-shaped recesses ( 2 . 4 . 1 ) that allow choosing different positions for the building blocks ( 2 ) with respect to the sections of cable ( 1 ).
[0120] FIG. 14 shows embodiments of building blocks ( 2 ) that are formed by two sections, each of them having an exposed surface ( 2 . 3 ) and an anchoring surface ( 2 . 4 ) for handling corners. In these embodiments, dovetail-shaped recesses ( 2 . 4 . 1 ) are on two inner faces and result in two exposed surfaces ( 2 . 3 ), one per plane of the wall converging in the corner.
[0121] FIG. 15 shows a spacing element ( 3 ) particularly configured for being inserted between cables.
[0122] According to other embodiments of the invention, a spacer ( 3 ) with a configuration that does not generate a gap in the construction of the wall because it is housed in the recess ( 2 . 4 . 1 ) of the block ( 2 ) where said cables ( 1 ) pass is used to maintain the separation between cables ( 1 ).
[0123] FIG. 16 shows the use of this spacing element ( 3 ) on a construction formed by a row of building blocks ( 2 ) with dovetail-shaped recesses ( 2 . 4 . 1 ) and also shows a second row of building blocks ( 2 ) that are slightly raised to allow seeing insertion of the spacing element ( 3 ).
[0124] Once the building block ( 2 ) is placed with the sections of cable ( 1 ) housed in the recess ( 2 . 4 . 1 ), the spacing element ( 3 ) is placed spacing out sections of cable ( 1 ) because they are located in the notches or grooves ( 3 . 1 ).
[0125] FIG. 17 shows an embodiment of a spacer ( 3 ) having two bodies attached to one another, a first body ( 3 . 2 ) intended for being housed in a dovetail-shaped recess ( 2 . 4 . 1 ) and a second body ( 3 . 3 ) spacing out two rows of blocks, giving rise to a gap or vertical separation.
[0126] The first body ( 3 . 2 ) has two bevels ( 3 . 2 . 1 ) used for leaving the space to which the passage of the section of cable ( 1 ) is limited such that it is confined in a position coinciding with the inner corner of the dovetail-shaped recess ( 2 . 4 . 1 ). The function of the spacer ( 3 ) is thereby obtained.
[0127] FIG. 18 shows another embodiment of a spacer ( 3 ) similar to the preceding embodiment, but the first body ( 3 . 2 ) and the second body ( 3 . 3 ) are vertically spaced from one another by a stripped plate ( 3 . 4 ). This configuration allows the first body ( 3 . 2 ) to be inserted in the recess ( 2 . 4 . 1 ) up to a greater depth and allows the second body ( 3 . 3 ) to have a larger area for supporting the building block ( 2 ) located above it. Given this larger area, the second body ( 3 . 3 ) is slotted ( 3 . 3 . 1 ) to allow the passage of the sections of cable ( 1 ).
[0128] FIG. 19 shows another example of spacer ( 3 ) where a vertical stripped plate ( 3 . 5 ) serving as a separation between two building blocks ( 2 ) arranged consecutively in one and the same row emerges from the upper surface of the second body ( 3 . 3 ). This separation allows there to be a vertical gap, and furthermore it allows this gap to be filled with the material of the spacer.
[0129] FIG. 20 shows the simple spacer ( 3 ) described in FIG. 12A in an enlarged view.
[0130] FIG. 21 shows a spacer ( 3 ) having a very elongated second body ( 3 . 3 ) for allowing passage of multiple sections of cable ( 1 ) through its grooves ( 3 . 3 . 1 ). This spacer allows filling extensive horizontal gap sections as shown in FIG. 22 .
[0131] Said FIG. 22 shows how the use of these spacers ( 3 ) with the second body ( 3 . 3 ) having a length equal to the width of a building block ( 2 ) or having the width of several building blocks ( 2 ) allows the generated horizontal gap to be filled with the material of the spacer ( 3 ). The spacer ( 3 ) can be manufactured from materials such as injected plastic, which allows using various colors, giving rise to high-quality finishes.
[0132] FIG. 23 shows a retaining anchor ( 4 ). The retaining anchor ( 4 ) comprises:
fixing means ( 4 . 1 ) for fixing to a fixed structure, fixing means ( 4 . 2 ) configured for being housed or being retained in a recess ( 2 . 4 . 1 ) of the building block ( 2 ),
and the retaining anchor ( 4 ) allows stabilizing the wall at one or more points with respect to the fixed structure.
[0135] According to the embodiment shown in this FIG. 23 , the retaining anchor ( 4 ) is formed by a die cut and bent metal stripped plate. The vertical section has a perforation that allows fixing ( 4 . 1 ) to a fixed structure. If the wall according to the invention is for example a coating wall, the fixed structure is the wall being covered.
[0136] The fixing means ( 4 . 2 ) configured for being housed in a recess ( 2 . 4 . 1 ) of the building block ( 2 ) are in this case a widened section with the dovetail shape of a recess ( 2 . 4 . 1 ) where the corners are beveled to allow the passage of sections of cable ( 1 ) performing the function of a spacer ( 3 ).
[0137] This function of spacer is shown in plan view in FIG. 24 in the example on the left. The width and shape of the fixing means ( 4 . 2 ) are such that the retaining anchor ( 4 ) enters the recess ( 2 . 4 . 1 ) and the bevels leave space for sections of cable ( 1 ).
[0138] In the embodiment on the right, the fixing means ( 4 . 2 ) are wider than the recess ( 2 . 4 . 1 ), such that the section of horizontal stripped plate of the retaining anchor ( 4 ) is trapped and retained between two or more building blocks ( 2 ) stacked on one another, whether or not they are vertically aligned, because the widening makes that it will not be housed in the recess ( 2 . 4 . 1 ), and it will only be retained in its position in plan view.
[0139] FIG. 25 shows an embodiment of a wall with three building blocks ( 2 ), once they are placed in the sections of cable ( 1 ), and with part of the retaining anchor ( 4 ) oriented towards the non-exposed part of the wall arranged for having its fixing means ( 4 . 1 ) for fixing to a fixed structure parallel to and supported on the wall to be covered (not shown in the drawing for the sake of clarity).
[0140] FIG. 26 shows an anchor ( 4 ) the fixing means ( 4 . 2 ) of which are an element having a complementary configuration of the recess ( 2 . 4 . 1 ) in which it is intended for being housed, except bevels ( 4 . 2 . 1 ) allowing the passage of sections of cables ( 1 ), on which there is a planar body ( 4 . 3 ) to give rise to the horizontal gap, and on the latter there is a vertical stripped plate ( 4 . 4 ) for the vertical gap. This embodiment incorporates all the elements: horizontal gap, vertical gap, spacer and retaining anchor.
[0141] FIG. 27 shows an embodiment of a building block ( 2 ) which, unlike the tile that is widely used in the preceding examples, has greater width. The first support base ( 2 . 1 ) has a longitudinal protuberance according to the direction X which is complementary to a longitudinal channel arranged in the second base ( 2 . 2 ). These complementary shapes mean that there is retention between rows of building blocks ( 2 ) according to the transverse direction Y with respect to the wall, and stability of the construction is greater.
[0142] The perspective view selected in FIG. 27 allows seeing the anchoring surface ( 2 . 4 ) where the recesses ( 2 . 4 . 1 ) are dovetail-shaped. As occurs in other configurations of any of the preceding examples, this figure shows how the recesses ( 2 . 4 . 1 ) have a configuration such that when stacked, they give rise to a continuous vertical groove that allows sections of cable ( 1 ) to extend when they are housed in the plurality of recesses ( 2 . 4 . 1 ) through which they pass along the entire length thereof.
[0143] These building blocks ( 2 ) additionally incorporate a dovetail-shaped anchor on the faces intended for being adjacent with contiguous building blocks ( 2 ) of the same row.
[0144] FIG. 28 shows another example of a building block ( 2 ) similar to the preceding example, where in this example the recesses ( 2 . 4 . 1 ) of the anchoring surface ( 2 . 4 ) have an L-shaped configuration.
[0145] As indicated above, FIG. 3D shows fixing means ( 1 . 1 ) fixing two sections of cable ( 1 ) for each position according to direction X, spaced from one another according to direction Y.
[0146] FIG. 29 shows a building block ( 2 ) suitable for this distribution of sections of cable ( 1 ) because the anchoring surface ( 2 . 4 ) has recesses ( 2 . 4 . 1 ) in which in each recess ( 2 . 4 . 1 ) there are two protuberances ( 2 . 4 . 1 . 1 ) at different depths which in turn give way to two housings for sections of cable ( 1 ).
[0147] FIG. 30 shows the same building block ( 2 ) with a spacer ( 3 ) in the stacking having two pairs of prolongations with successive recesses adapted for receiving pairs of sections of cable ( 1 ). The spacer ( 3 ) can therefore be positioned in the stack between building blocks ( 2 ), defining the horizontal gap, and establishing a reference with respect to the relative positioning of this spacer ( 3 ) and the building blocks ( 2 ) when stacked.
[0148] Optionally, both horizontal and vertical continuous spacers ( 3 ) can furthermore be used as permanent formwork if the possible space between the fixing wall to be covered and the wall according to the invention in any of its thicknesses can be filled with cement mortar, insulating mortar, expanded polyurethane or any other thermal and/or resistant insulating material that requires being confined. The spacers ( 3 ) establish a barrier that prevents the material filling in the space between the fixing wall to be covered and the wall according to the invention from coming out through the gaps generated by said spacers ( 3 ).
[0149] Although the main application of the invention is the formation of a wall intended for covering another fixing wall, according to other embodiments it is possible to have two walls according to the invention arranged parallel to and spaced out from one another.
[0150] According to another embodiment, between both walls there is one or more retaining anchors ( 4 ) which together strengthen walls arranged parallel to one another. When these walls that are spaced out from one another use spacers ( 3 ) forming gaps and a barrier between the space located on either side of the wall, they also allow filling with cement mortar, insulating mortar, expanded polyurethane or any other thermal and/or resistant insulating material that requires being confined.
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The present invention relates to a constructive assembly for building walls which allow forming wall coverings. Examples of coverings that can be formed with the present invention are façades, party walls and partition walls. The constructive assembly is characterized by being formed by a plurality of cables intended for being arranged under stress in the vertical position, and a plurality of blocks having coupling means for coupling them to cables such that integral joining is assured, forming the wall. Walls thus formed do not require the use of mortar or the need to be built by skilled labor, making it possible to build reformed or new exposed wall faces more easily and in a cleaner and faster manner and, in the case of thin material (tiles), with the certainty that such material will not become detached.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a divisional from U.S. patent application Ser. No. 11/773,175 filed Jul. 3, 2007 now U.S. Pat. No. 7,665,356 which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The invention is generally related to oil and gas wells, and more particularly to determination of the integrity of cement between two points in a borehole as indicated by permeability or transmissibility.
BACKGROUND OF THE INVENTION
Geological sequestration of CO 2 is currently being studied as a possible method for mitigating the rapid rise of greenhouse gases in the atmosphere. For example, CO 2 might be sequestered in the permeable layers of formations associated with oil and gas wells. Such the permeable layers are typically located beneath an impermeable layer which form a natural barrier against upward movement of the CO 2 . Well boreholes provide a pathway for moving CO 2 into the permeable layer. However, it is possible for leakage pathways to form through the cement annulus between the well casing and the formation. Cement, in a multitude of reaction steps, has been demonstrated to deteriorate and form CaCO 3 in the presence of CO 2 and water (see Ch. 7 Special Cement Systems, by E. B. Nelson et al., Cement Handbook, section on Cements for Enhanced Oil Recovery by CO2-Flooding). In order for long term CO 2 storage to be practical, relatively little of the injected gas can be permitted to leak back into the atmosphere (see IPCC's special report on carbon dioxide capture and storage, pg 197, 2006). It is therefore desirable and important to know the quality of the cement in a formation selected for CO 2 sequestration, both before and after injection of CO 2 .
Until now, formation tests have been designed to measure the permeability of a reservoir. Although quantifying skin is a common practice in well testing, and it may be appealing to regard cement as a skin, conventional skin estimation procedures work only when skin is sufficiently transmissible, i.e., the skin zone permeability is not orders of magnitude smaller than that of the formation. The reason for this is the skin zone is treated as being in pseudo-steady state, i.e., pressure drop across the skin region is directly related to flux (van Everdingen, A. F. 1953, The Skin Effect and its Influence on the Productive Capacity of a Well, Trans. AIME, 198, 171-176). Consequently, existing techniques are not entirely suited to estimating degradation of cement.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the invention, a method of estimating hydraulic isolation between first and second points in a material under test that is disposed between a hydraulically impermeable barrier and a geological formation comprises the steps of: forming first and second openings in the hydraulically impermeable barrier adjacent to the first and second points under test, the openings being formed up to, but not completely through, the material under test; causing a change in pressure at the second opening; at the first opening, measuring transmission of the pressure change across the material; and storing the measured pressure change for estimating hydraulic isolation between the first and second points.
In accordance with another embodiment of the invention, apparatus for estimating hydraulic isolation between first and second points in a material under test that is disposed between a hydraulically impermeable barrier and a geological formation comprises: an ablating component operable to form first and second openings in the hydraulically impermeable barrier adjacent to the first and second points under test, the openings being formed up to, but not completely through, the material under test; a probe operable, when set at the first opening, to measure transmission of a pressure change across the material in response to a change in pressure at the second opening; and a memory operable to store the measured pressure change, from which hydraulic isolation between the first and second points is estimated.
In accordance with another embodiment of the invention, apparatus for generating a pressure pulse of known magnitude comprises: a first chamber filled with an incompressible fluid; a second chamber filled with a gas, the second chamber hydraulically linked with the first chamber; a third chamber filled with an incompressible fluid, the third chamber hydraulically linked with the second chamber; a fourth chamber filled with an incompressible fluid, the fourth chamber hydraulically linkable with the third chamber via a first valve; means for sensing pressure in the third chamber; and means for sensing pressure in the fourth chamber, whereby a pressure pulse of a magnitude corresponding to the sensed pressure differential between third chamber and the fourth chamber with the valve closed can be generated by opening the valve.
In accordance with another embodiment of the invention, a method for generating a pressure pulse of known magnitude comprises: with a tool having a first chamber filled with an incompressible fluid, a second chamber filled with a gas, the second chamber hydraulically linked with the first chamber, a third chamber filled with an incompressible fluid, the third chamber hydraulically linked with the second chamber, a fourth chamber filled with an incompressible fluid, the fourth chamber hydraulically linkable with the third chamber via a first valve, means for sensing pressure in the third chamber, and means for sensing pressure in the fourth chamber, with the first valve in a closed state, creating a pressure differential between third chamber and the fourth chamber and, generating a pressure pulse of a magnitude corresponding to the sensed pressure differential by opening the first valve.
Further features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying Drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a pressure tester tool utilized in a borehole to determine cement integrity adjacent to a permeable layer.
FIG. 2 illustrates a multi-probe pressure test tool.
FIG. 3 illustrates a mechanism for generating a pressure pulse of known magnitude.
FIG. 4 illustrates a single-probe pressure test tool.
DETAILED DESCRIPTION
Referring to FIG. 1 , a pressure tester tool ( 100 ) is utilized to test the integrity of cement ( 102 ) in a well completion. The pressure tester tool is secured to a spool ( 104 ) of cable located at the surface. The cable is spooled out in order to lower the pressure tester tool ( 100 ) into the borehole to a desired depth, e.g., above a permeable layer ( 106 ) into which CO 2 has been, or might be, injected. The pressure tester is in communication with a control unit ( 108 ) located at the surface via electrical, optical, wireless, or other suitable communications links, through which data and instructions may be transmitted and received. In the illustrated embodiment, the pressure tester tool is responsive to instructions transmitted from the control unit ( 108 ), and transmits pressure data to the control unit in real time. Although a tethering cable is shown, the pressure tester tool could be permanently installed in the borehole. Alternatively, the pressure tester might operate autonomously, and might accumulate data in memory for subsequent retrieval, e.g., when brought to the surface.
The formation surrounding the borehole includes the hydraulically permeable layer (reservoir) ( 106 ) adjacent to an impermeable layer ( 110 ) or seal, and various other layers which make up the overburden ( 112 ) (not shown to scale in FIG. 1 ). The permeable layer ( 106 ) is, potentially at least, utilized for carbon sequestration. The borehole is equipped with a completion which functions to maintain the structural integrity of the borehole within the formation. The completion also provides a hydraulic barrier between the formation and the borehole. In the illustrated embodiment the completion includes a tubular casing ( 114 ), which may be constructed of metal, fiberglass, or other substantially hydraulically impermeable material. The completion also includes cement ( 102 ) which is disposed in the annulus between the casing ( 114 ) and the formation ( 110 ). Ideally, the cement ( 102 ) should be structurally sound in order to prevent CO 2 leakage. The pressure tester tool is utilized to determine the integrity of the cement, particularly in the area above the permeable layer ( 106 ).
Operation of one embodiment of the tester tool ( 100 a , FIG. 2 ) will now be described with reference to FIGS. 1 and 2 . Because of the relatively large diameter of the tester tool relative to the inner diameter of the casing, any injection tubing that is present may have to be pulled out before testing begins. A first packer ( 200 ) is set to close when the tubing is pulled out, and if necessary, a second packer is also set above the tubing packer ( 200 ). Typically, the annular cement ( 102 ) will be saturated with water as its pore fluid. In order to reduce tool storage induced delay and obtain the correct borehole pressure gradient, both the tool ( 100 a ) and the borehole are filled with brine in preparation for testing. This may be accomplished in a number of ways, including flushing the flowline with the borehole fluid after opening the hydraulic lines to the borehole. Alternatively, the tool may also be flushed at the surface. It is desirable that all residual gas in the tool flow lines are flushed out.
Holes are formed through the casing in order to prepare for a test of the integrity of the cement. The holes may be formed by mechanical, electrical, chemical or laser ablation. In the illustrated embodiment, the tool drills (mechanically) through the casing ( 114 ) with a bit in a first location in order to establish hydraulic communication with the cement ( 102 ). The drilling is stopped at the cement interface with the casing. This may be accomplished based on the known casing thickness, and by monitoring the torque on the drill bit. In particular, an initial increase in drill bit torque is indicative of contact with the casing, and a subsequent sudden change in the torque is indicative of the drill bit having reached the cement-casing interface. The length of travel of the drill bit (or quill) between torque gradient events may also be measured against the known casing thickness to verify or determine when to cease drilling. Drilling may continue some distance into the cement, but only to a distance smaller than the cement thickness such that the formation is not reached. In the illustrated embodiment, penetration of the drill bit into the cement is limited to a minute fraction of the overall thickness of the cement.
Once the hole has been drilled at the first location, a “sink” probe ( 202 ) is set at that location. The probe includes a seal which, when the probe is set, hydraulically isolates the probe sensor from the borehole fluid. Nevertheless, the set probe may read the cement fluid pressure as being about the same as the borehole pressure (equal to the brine column in gauge pressure) and, in the absence of any cement permeability, continue to hold this pressure. A slow drift suggests minor permeation through the cement, and that the fluid pressure in the cement column is different from that of the hydrostatic column pressure. This may occur due to pressure anomalies in formation layers. If no noticeable trend in pressure is seen upon setting the first probe, two possibilities arise: (i) no measurable hydraulic communication is present in the cement; or (ii) cement fluid is close to the borehole fluid pressure. The latter may be tested by adding more borehole fluid as explained in greater detail below and, if no observable trend in pressure exists, increased likelihood of the first possibility is indicated. One advantage to filling the borehole entirely with brine is that this will give a pressure equivalent to an entire hydrostatic column.
It is preferable for testing purposes that the borehole pressure be as close to the native cement fluid pressure as practical. One technique for accomplishing this is to start with a borehole fluid level height corresponding to a pressure that is slightly lower than the expected cement pressure. The probe is set first, and if there is an upward drift in pressure, the probe seal is relaxed, and more borehole fluid added. The probe is then set again, and the pressure trend noted. The cycle may be repeated as many times as necessary to achieve equalization, noting that each foot of water column height corresponds to about 0.43 psi of pressure increase at the bottom of the borehole.
Once the pressure drift is found to be small, and within acceptable range, a second (observation) probe ( 204 ) is set. Setting the probe includes hydraulically sealing the probe against the casing. The second probe should be in hydrostatic equilibrium with the first probe. After both probes are set, the internal hydraulic communication between the probes is terminated with an isolating valve. Note that the observation probe may be offset either horizontally, or vertically, or both. Further, multiple observation probes may be set in any combination of offsets.
Once the sink and observation probes are set, a pressure pulse is induced in the “sink” probe ( 202 ). The pressure pulse may be generated by a fixed pressure increase within the tool. The observation probe (or probes) are monitored for a responsive pressure signal. If a pressure pulse is observed at the observation probes, poor hydraulic isolation in the cement is indicated. The decay of the pressure within the pulsed probe as well as any observed pulse in the offset observation probe(s) may be used to adjudicate the effectiveness of cement isolation. In particular, the hydraulic isolation can be quantified based on the difference in time between the pressure pulse and the responsive pressure signal. In this manner the cement transmissibility and permeability may be calculated.
Those skilled in the art will recognize that it is quite difficult to control the pressure pulse with hydraulic lines filled with brine. An embodiment of a mechanism for reliably generating a pressure pulse of known magnitude is illustrated in FIG. 3 . The illustrated pulse generator includes an isolation valve (V 1 ) that may be actuated during testing in response to commands from either the control unit or the tool itself. Opening the isolation valve allows the brine in chamber ( 312 ) to hydraulically communicate to an air filled chamber ( 302 ) through a floating piston ( 308 ). Hydraulic oil in chamber ( 306 ) may be pumped on one side of the floating piston ( 304 ), which has stops on either side. A second piston ( 308 ) separates the air from the brine in a brine chamber ( 310 ) and the brine line (chamber) ( 312 ) to the probe. The second piston also has two stops, one of which it shares with the first piston.
In order to prepare to generate the pressure pulse, isolation valve (V 1 ) is open and valve (V 2 ) is closed. Valve (V 2 ) should be as close to the probe as practical. Initially, the pressure is built in the probe line by pumping hydraulic oil into chamber ( 306 ), which compresses the air in the chamber, and which in turn builds pressure in the probe hydraulic line ( 312 ). When the pressure is built sufficiently (e.g., a few hundred psi, at most), the pumping is stopped and valve (V 1 ) is then closed. In order to determine when the pressure is built sufficiently, pressure is monitored at one or more pressure sensors (P) and (P 1 ). Valve (V 2 ) is then opened in order to generate the pressure pulse. The resulting pulses in the pulsing probe as observed by pressure sensor P, and the pressure sensor P in a chamber (not shown) associated with the observation probe 1 ) may be differentiated and correlated, and the correlation time should be directly related to the permeability of cement. Detailed modeling will yield the exact nature of this correlation. The principles behind such correlations for a vertical well in an infinite medium are illustrated in published U.S. patent application 20050270903, and in an SPE paper, T. S. Ramakrishnan and B. Raghuraman, 2005, A Method for Continuous Interpretation of Permanent Monitoring Pressure Data, presented at the SPE/ATCE Annual meeting, SPE90910, both of which are incorporated by reference.
An alternative embodiment does not have valve (V 2 ). In this embodiment the pressure buildup in the probe (at the cement interface) is relatively gradual, and will depend on the pumping rate of the hydraulic fluid and the compressibility of the air. Any inability to build pressure in this line implies continuous leakage of liquid into the cement, and if the pistons top out, it clearly indicates a complete disintegration or lack of cement at the zone of interest.
Testing in a monitoring well should be similar to that of the injection well if the well is perforated and has tubing. If the well has no tubing, and there are no perforations, assuming the diameter of the well will accept a cased hole formation tester, a packer is set below the test zone. As in the injection well, the well is filled with brine. The test then follows that of the procedure in the injection well.
Referring now to FIG. 4 , in an alternative embodiment of the test tool ( 100 b ), only one probe ( 400 ) is needed. As in the previously described embodiment, at least one packer ( 200 ) is set so that the bottom section of the borehole is sealed off. The probe ( 400 ) is initially set at a location ( 402 ), and a hole is drilled through the casing ( 114 ) to the cement ( 102 ). Fluid pressure (measurable only when the cement has a measurable permeability) is obtained by letting the probe come to equilibrium, as evidenced by an imperceptible decay in pressure. As discussed above, if the cement fluid pressure is measurable, the level in the borehole is adjusted so that the wellbore fluid pressure is in equilibrium with cement fluid pressure.
The next step is to retract the probe ( 400 ) from the wellbore and set it at an offset location ( 404 ), i.e., either horizontally or vertically displaced. Once the probe is set at an offset location ( 404 ), additional fluid is added to the borehole, or the borehole pressure is raised through air pressure at the top of the wellbore. A pressure increase of 10 psi may be adequate. An increase in the bottom hole pressure corresponding to the hydrostatic head therefore occurs. The pressure increase is communicated to the cement fluid through the hole drilled through to the cement in the first location. If the cement between locations ( 402 ) and ( 404 ) has a permeability at all, then location ( 404 ) would be found to have a slow and steady pressure increase from which the transmissibility between ( 402 ) and ( 404 ) may be inferred. In particular, the pressure increase over a period of time is matched with a pressure response over a period of time, and the time differential between the pressure increase and pressure response is indicative of transmissibility.
In the absence of tubing and perforations in the monitoring well, a packer is first installed in the casing adjacent to a shale layer above the formation that had CO 2 uptake. The remainder of the testing is carried as already described above.
While the invention is described through the above exemplary embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Moreover, while the preferred embodiments are described in connection with various illustrative structures, one skilled in the art will recognize that the system may be embodied using a variety of specific structures. Accordingly, the invention should not be viewed as limited except by the scope and spirit of the appended claims.
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A cased hole pressure test tool is used to determine the integrity of cement between two points in a borehole in terms of permeability or transmissibility. The test tool drills at least one probe hole through the casing up to the cement. In one embodiment, two probes are set and the dissipation of a pressure pulse through the cement initiated by the first probe is observed by the second probe. In another embodiment, one probe hole is in hydraulic communication with the borehole fluid and a single offset probe is set in another probe hole. Fluid (water) is then added to the borehole to cause a pressure increase in the borehole fluid. Detection of the pressure increase through the cement by the offset probe is indicative of a loss of hydraulic isolation. Packers may be used to isolate the portion of the borehole under test. A mechanism for generating a pressure pulse of known magnitude is also described.
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FIELD OF THE INVENTION
The present invention is related to an oil-spill detection system, and more particularly to an interferometric oil-spill detection system.
BACKGROUND OF THE INVENTION
Oil spillage could occur in numerous locations such as seabed exploration sites, oil refineries, or areas close to oil tanks and pipelines. The loss of oil causes both capital and environmental damages. In particular, the environmental damage often takes a long period of time to recover. It is desirable to have an automatic oil spill detection system that monitors oil leaks in the early stage and transmits a suitable warning signal to dispatch a rescue effort for repair.
The existing oil spill detection schemes are mostly in two categories, the scanning type and the fixed-location type. The scanning type, usually satellite-based, monitors a large area of many square kilometers. For example the synthetic aperture radar (SAR) has a large coverage over seawater. The SAR imagery previously had some difficulty in distinguishing dark areas and lookalikes from oil spills. The fixed-location oil spill detectors are often buoyantly situated or anchored. Sometimes the buoy is set adrift but its coordinates are controlled by the global positioning system. These fixed-type oil-spill detectors monitor oil spills by chemical or optical means. Chemical reactions usually cause pollution themselves and chemicals are relatively difficult to maintain. Among the optical means, the generation of UV-induced fluorescence and the change of surface reflectivity on surface oil are the two existing oil-spill detection mechanisms. Unfortunately all of the existing detection schemes have one or several disadvantages, such as poor reliability, high power consumption, high cost, difficulties in maintenance, and complexity.
The SAR oil spillage detection technique is aimed for large-area monitoring while those fixed-location buoy detectors are suitable for real-time, prompt spillage warning at the deployed area. However, both the SAR oil detection technique and the fixed-location buoy detector have the disadvantages of high cost, difficulties in maintenance, and complexity. Therefore, it is desirable to design an early-warning type, surface-oil detector by using optical interferometric techniques. Unlike the existing optical schemes, the interferometric technique detects the interferometric images formed by oil thin films or by oil droplets. The interferometric image formation is more related to the oil geometry than its material property. Integrated into a compact circuit board, this technique is relatively simple, reliable, low-cost, and low-power consuming.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an interferometric oil-spill detection system for detecting the existence of surface oil or oil drops in water.
It is further an object of the present invention to provide a relatively simple, reliable, low-cost, and low-power consuming oil-spill detection system.
It is further an object of the present invention to provide an interferometric oil-spill detection system for detecting the existence of oil spillage on a body of water by using interferometric techniques. The interferometric oil-spill detection system includes a light source for providing an incident light to the oil-spilled body of water, an image extraction device for receiving the reflected light from the oil-spilled body of water and recording the interference fringes of the reflected light, and an image process device connected to the image extraction device for determining whether oil spillage exists according to the interference fringes.
Preferably, the light source is an electromagnetic radiation source of any kind in the optical wavelength range. More preferably, the light source is a laser for providing coherent or partially coherent electromagnetic radiation. The light source consists of one or a few optical elements for collimating, focusing, defocusing, shaping, or directing the optical electromagnetic radiation to the body of water.
Preferably, the image extraction device is a one-dimensional charge-coupled-device (CCD) array sensor, or a CMOS linear sensor array, or a two-dimensional array of the same.
Preferably, the image process system is a computer having a computer program capable of processing the interference fringes and determining whether oil spillage exists.
It is further an object of the present invention to provide a method for detecting the existence of oil-spill on a body of water and transmitting a warning signal to dispatch a rescue effort for repair by using an oil-spill detection system comprising a light source, an image extraction device and an image process device. The method includes the steps of sending a light from the light source to the oil-spilled body of water, receiving the reflected light from the oil-spilled body of water, recording the interference fringes by the image extraction system, processing the interference fringes and checking whether the specific interference parameters are above the threshold values pre-programmed in the image process device, and thereby transmitting a warning signal to dispatch a rescue effort for repair when the specific interference parameters are above the pre-programmed threshold values.
In accordance with one aspect of the present invention, the specific interference parameters are fringe intensity, infringe width, and the number of fringes detected from the image sensor.
It is further an object of the present invention to provide an oil-spill detection system for detecting the existence of oil spillage on a body of water by interferometric techniques. The oil-spill detection system includes a light source system and a discerning medium. This light source system includes a light source and one or a few lenses for providing an incident light to the oil-spill on the water of body. The discerning medium has an image sensor for receiving the reflected light from the oil-spilled body of water, and a logic circuit connected to the image sensor for processing the interference light to determine whether oil spillage exists according to the existence of the interference fringes.
Preferably, the discerning medium is an integrated circuit element, which includes the image sensor and a logic circuit monolithically integrated in a semiconductor chip or a compact circuit board similar to the size of a computer interface card powered by a low-voltage power supply or a solar battery.
More preferably, the light source system and the discerning medium are fabricated monolithically in a semiconductor circuit chip or a compact circuit board similar to the size of a computer interface card powered by a low-voltage power supply or by a solar battery.
Preferably, the light source is any coherent, partially coherent, or incoherent electromagnetic radiation source generating radiations at the optical wavelengths.
Preferably, the light source is a laser of any kind providing coherent or partially coherent electromagnetic radiation.
Preferably, the image sensor is a one-dimensional CCD array sensor, or a CMOS linear sensor array, or a two-dimensional array of the same.
It is further an object of the present invention to provide a method for detecting the existence of oil-spill on a body of water and transmitting a warning signal to dispatch a rescue effort for repair by using an oil-spill detection system comprising a light source and a discerning medium, wherein the discerning medium has an image sensor and a logic circuit. The method includes the steps of transmitting an incident light from the light source to an oil-spilled body of water, receiving the reflected light from the oil-spilled body of water by the image sensor of the discerning medium, processing the interference fringes formed by the reflected light and checking whether the specific interference parameters are above the threshold values pre-programmed in the logic circuit of the discerning medium, and thereby transmitting a warning signal to dispatch a rescue effort for repair when the specific interference parameters are above the threshold values.
Preferably, the specific interference parameters are fringe intensity, infringe width, and the number of fringes.
The present invention utilizes two light interference mechanisms, the thin-film interference and the wavefront-splitting interference. It may be best understood through the following descriptions with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the configuration for performing the thin-film interference calculation according to the present application, wherein the three media are air, oil, and water, respectively, and the total reflected optical field is the sum of all individual reflected fields, E r1 , E r,2 , E r,3 . . . (θ 1 is the incident angle in the medium 1 and θ 2 is the refractive angle in the medium 2 );
FIG. 2 is a computer simulation of the thin-film interference fringe intensity versus the incident angle for TE and TM incident waves, wherein the refractive indices of the three media in this example are n 1 =1 (air), n 2 =1.1 (oil), n 3 =1.3 (water), and the gasoline film thickness is assumed to be 20 μm;
FIG. 3 is the schematic illustration of wavefront-splitting interference resulting from an oil drop;
FIG. 4 is the scattering configuration for modeling the wavefront-splitting interference, wherein a plane wave is incident normally in the—z direction onto a oil bump, the reflected wave is approximately a superposition of a plane wave and a spherical wave;
FIG. 5 is a typical wavefront-splitting interference image resulting from a real oil drop in the experiment;
FIG. 6 is a schematic view showing a oill-spill detection system according to the preferred embodiment of the present invention;
FIG. 7 shows the output of the preferred oill-spill detection system on a LabView™ computer platform, wherein the horizontal axis is the position coordinate of the interference fringes, the vertical axis is the fringe intensity (both in arbitrary units), the threshold intensity is set at 160 in the vertical scale, the threshold fringe width is set at 4 in the horizontal scale, and the threshold number of qualified interference fringes is set at 10, as shown in the T.P.N. box;
FIG. 8 is the data processing flowchart of a discerning circuit according to another preferred embodiment of the present invention; and
FIG. 9 shows a typical interference fringe signals before and after digitization, wherein the lower trace shows the amplified fringe signals at Point A of FIG. 8, and the upper trace is the digitized fringe signal at Point B of FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In general, oils on a body of water are of two kinds, one with its surface tension smaller than water and one with its surface tension larger than water. The one with a smaller surface tension spreads itself into an oil thin film above the water surface, whereas the other with a larger surface tension often forms oil drops in water. For example, gasoline spreads itself quickly into a thin film above water and heavy engine oil sometimes forms droplets. The interferometric techniques for detecting both types of oil spillage on a water surface is delineated in the following.
A thin layer of oil on a water surface may generate rainbow-type interference fringes when viewed under the sun, a broadband white light source. This phenomenon is often observed routinely in one's life. It results from the well-known thin-film interference, where the reflected light from the oil surface interferes with that from the water surface below the oil film. Because the sun is a white light source, one observes constructed interference of different colors at different angles. When incident by a narrow-band coherent light source, like a laser, the interference image is even more pronounce, interleaved with bright and dark stripes corresponding to the constructive interference and destructive interference at that particular wavelength. Thin-film interference occurs only when the refractive index of the film differs from those sandwiching the film.
FIG. 1 illustrates the scattering configuration for the theoretical calculation according to the present application, wherein a monochromatic light is incident from the medium 1 toward the medium 3 with the thin film, the medium 2 , sandwiched in between. By performing the standard infinite-sum calculation for the successive reflected field,
E
r
=E
r1
+E
r2
+E
r3
the reflectance expression as following is obtained, R = I r I 0 = ( ρ 23 - ρ 21 1 - ρ 21 ρ 23 ) 2 + F sin 2 δ 2 1 + F sin 2 δ 2 , ( 1 )
where F = 4 ρ 21 ρ 23 ( 1 - ρ 21 ρ 23 ) 2
is the coefficient of finesse, δ is the optical phase difference between successive reflections, ρ mn is the reflection coefficient when light is incident from the medium m to the medium n. The phase difference is given by δ = 2 π λ 0 2 d n 2 cos θ 2 ,
cosθ 2 , where λ 0 is the free-space wavelength of the incident light, d is the thin film thickness, and θ 2 is the refractive angle in the medium 2 . The refractive angle θ 2 can be found from Snell's law with a known incident angle θ 1 in the medium 1 . If the medium 1 and medium 3 are the same materials and therefore ρ 21 =ρ 23 , the reflectance in Eq. (1) is reduced to the well-known etalon formula R = I r I 0 = F sin 2 δ 2 1 + F sin 2 δ 2 . ( 2 )
In the etalon formula, the contrast or visibility of the reflected image is always 100%, because the destructive interference reflects no light to the medium 1 . However, for the case of three medium layers, the reflected light from the medium 3 can not completely cancel the light refected from the medium 1 in its destructive phase. Therefore the visibility of the reflection fringes from an oil thin film sandwitched between air and water is not as good as an etalon, depending on the difference among the refractive indices of the three media. Furthermore the reflection coefficients ρ 21 and ρ 23 are functions of light polarization, as can be seen from the Fresnel equations. FIG. 2 illustrates the reflectance versus the incident angle calculated from Eq. (1) for a TM incident wave and a TE incident wave. The TE incident wave has its electric field polarized normal to the plane of FIG. 1 and the TM incident wave has its electric field polarized in the plane of FIG. 1 . The refractive indices of the three media in the calculation are n= 1 =1 (air), n 2 =1.1 (October 1995 unleaded gasoline, Chinese Petroleum Corp.), and n 3 =1.3 (water). The thickness of the gasoline layer at a certain location varies over the time course of oil spillage, depending on the amount of gasoline in that area. In FIG. 2, a thickness d=20 μm is arbitrarily choosen to illustrate a typical situation. The number of interfernce fringes in FIG. 2 increases with the thickness of the oil layer over a fixed range of the incident angle. For TM-wave incidence, no light is refected at the Brewster angle near 48°. However, it is evident that TM polarization shows more intensity modulation and thus gives better visibility.
When the refactive indices of the oil and water are not much different, the reflectance expression (1) reduces to R = I r I 0 ≈ ρ 21 2 + 4 ρ 21 ρ 23 sin 2 δ 2
with the approximation ρ 23 ≈0 and |ρ 21 |>>|ρ 23 |. It is straightforward to show that the visibility becomes V = I r , max - I r , min I r , max + I r , min ≈ 2 | ρ 23 ρ 21 | ≈ 0.
Therefore the thin-film interference fringes might not be discernible by an image recording aparatus when the refractive indices of the second and third media are very close to each other. However, highly visible interference fringes were observed in the experiment according to the present invention, when the medium 2 was the Castrol 10W-60 engine oil with its refractive index n=1.4 and the medium 2 water with its refractive index n=1.3. The interference fringes result from the splitting of the laser wavefront at the joint of the oil and water interface, as FIG. 3 illustrates. In particular, some oil has a larger surface tension, forming a curved surface at the edge immediately next to a water flat. The radius of curvature of the curved surface, typically less than a millimeter, can be much smaller than that of the laser wavefront if the laser source is placed far away or the laser beam diverges quickly. Therefore, the reflected wave is approximately a superposition of a plane wave and a wave with its wavefront conforming to the curved oil edge. These two waves form an interference pattern in the far field. Because the refractive indices of the oil and water are close to each other, the visibility of the interference pattern is nearly 100%. The mechanism is in fact similar to the wavefront-splitting interference. As shown in FIG. 3, a curved wavefront and a nearly plane-wave wavefront, derived from a single laser wavefront at the joint of oil and water, interfere with each other in the far field.
For oils with a small surface tension, the same technique applies as well. When oil starts to spread from a high concentration area on a water surface, it moves with a curved edge in the depth direction and eventurally forms a thin oil layer on water. As an early warning system, this technique is capable of picking up the interferene signal at the initial phase of oil spread. Moreover, surface oil is often broken into many dorplets or islands under a shaky water environment, and those oil droplets and islands can be effective scattering centers for wavefront-splitting interferometry.
The interference can be best appreciated by summing a plane wave and a spherical wave. FIG. 4 shows this simplified configuration, where a plane wave is incident normally to a spherical oil bump of radius r above a water surface. The dark dashed lines above the water surface represent the wavefronts of the plane wave and the spherical wave, and the thin dashed lines are the virtual wavefronts originating from the spherical center of the oil bump. In the far field z=d, the scattered field is approximately the superpostion of a plane wave and a spherical wave, originating at a distance r 0 below the water surface at z=0. At large d, the spherical wave can be approximated by a paraboloidal wave, given by the phasor representation E s = I 0 exp [ - j k d - j k r 2 2 d ] , ( 3 )
where I 0 is the normalized intensity of the laser at z=d, r is the distance from the z axis, j={square root over (−1)} is the imaginary unit, and k = 2 π λ
is the wavenumber. Assuming that the plane wave field at z=d has a comparable intensity, one obtains its phasor representation
E p ={square root over ( I 0 )} exp[−jkd] (4)
The total intensity at z=d is therefore I ( z = d ) = | E s + E p | 2 = 4 I 0 cos 2 ( k r 2 4 d ) . ( 5 )
Equation (5) predicts the N-th constructive interference ringe at the radius of
r N ={square root over (2 dλN )} (6)
The constructive interference at z=d forms a series of bright rings with a reducing separation in r. For example, to have r 1 =1 mm for λ=670 nm, d is about 75 cm. If the image plane is 30 cm above the water surface, the radius of curvature of the oil bump is 45 cm. Those highly visible rings with their shape mimicing the oil drop were frequently observed in the experiment of the present invention. FIG. 5 shows a typical interference image, in which the laser incident angle is 80° with respect to the normal of the water surface, the laser wavelength is 670 nm, and the distance between the water surface and the image plane is 30 cm. The oil drop was formed by the Castrol 10-60 W engine oil with a measured refractive index of 1.4.
FIG. 6 illustrates the oil-spill detection system according to the preferred embodiment of the present invention, where a 670 nm-wavelength diode laser module (made by Simpatico Co. Ltd) is the light source, an image extraction device records the interference fringes, and the image process system determines whether oil spillage exists. Since the oil film thickness is so thin that the interference fringes can even be viewed under a white light source, the coherence length of the laser source is relatively not important. The diode laser module consists of a 6.4 mW, 670 nm laser diode and an aspherical lens positioned at 1 cm in front of the diode. The aspherical lens has a 3-mm diameter aperture, preserving the central part of the laser wavefront and clipping 60% of the laser diode power to make a circular beam. Since the lens aperture only transmits a small portion of the diode laser wavefront, the laser module produces a 2.5 mW, nearly flattop, circular beam with a half divergent angle of 0.5 mrad in both transverse directions. To expand the laser beam, a 5-cm focal length, double convex lens is installed at a 3-cm distance from the aspherical lens. A 2.5-cm diameter, circular laser beam is generated on the image screen (not shown). The distance between the diode laser module and the water surface is 22 cm and that between the water surface and the image screen is 30 cm, as shown in FIG. 6 . The laser waist, after the focusing lens, is about 14 cm from the water surface. Therefore the radius of curvature of the laser wavefront is much larger than that of the curved oil edge, which allows the wavefront splitting interference to be modeled by using a plane wave and a spherical wave in the previous section. In this experiment, the laser incident angle is about 75° relative to the normal of the water surface. At this incident angle, the laser beam has an elliptical beam profile on the water surface with its major axis=3.8 cm and its minor axis=1 cm.
In the imaging experiment of the present invention, a charged-coupled-device (CCD) camera is firstly employed as the image extraction device. The CCD signal is connected to a National Instrument IMAQ image capture board installed in a computer (i.e. image process system). A LabView™ computer code processes the recorded image, and determines whether the image is indeed an interference fringe pattern. In the second phase of the experiment, according to the present invention, the whole imaging and discerning system is replaced with a CMOS linear sensor array connected to a compact, integrated, logic circuit.
In the CCD-LabView™ system (i.e. the oil-spill detection system) of the present invention, a National Instrument IMAQ card captures the CCD image and displays the interference fringes on a computer. It is necessary to program the LabView™ such that the computer is capable of scanning the intensity signal linearly both in the vertical and horizontal directions throughout the two-dimensional image. During the scanning process, the program automatically checks three threshold parameters, the fringe intensity, the fringe width, and the number of fringes. The threshold values set the least condition of sending out a warning signal in the event of oil spillage. Checking the fringe intensity ensures that the image signal is above the noise level and checking the other two parameters guarantees the existence of interference fringes. The linear scan sends out a warning signal whenever it detects a set of interference fringes that satisfies all three threshold values. FIG. 7 shows a typical computer output of the detection system according to the present invention, where the horizontal axis of the window is the position coordinate of a one-dimension image sample from the CCD camera and the vertical axis is the intensity of that particular sample. The units are arbitrary. The horizontal line intercepting the intensity signal sets the intensity threshold at 160 in the vertical scale. For this particular case, the threshold fringe width is 4 in the horizontal scale, and the threshold number of qualified interference fringes is 10, as shown in the T.P.N. box. In FIG. 7, the automatic scanning process returns a result of 15 qualified interference fringes, as the # Found box shows. The warning button lights up whenever the scanned sample satisfies all three threshold values. The LabView™ program of the present invention has the full flexibility in presetting the three threshold values, according to the field conditions.
In order to minimize the size and cost, the CCD camera and the image-processing computer can be replaced by a discerning circuit board. The circuit board consists of a Hamamatsu N-MOS linear image sensor (S3923-256Q) and a logic circuit for checking the three threshold parameters given previously. In the embodiment, the circuit board is powered by a 5 Volt DC power supply and its overall size is similar to a typical computer interface card.
A 250 kHz, 50% duty-cycle, 2.5 Volt square wave serves as the master clock of the Hamamatsu image sensor. A 100 Hz, 50% duty cycle square wave modulates the 250 kHz master clock to separate independent measurements. In each of the 10 msec period, one cycle of the 100 Hz, the interference intensity information is extracted by the Hamamatsu linear image sensor, amplified in an operational amplifier, and analyzed by three logic stages for threshold value checking. FIG. 8 is the data flowchart of the circuit according to the present invention, and FIG. 9 shows the output waveforms at the points A and B in FIG. 8 . The lower trace of FIG. 9 illustrates the amplified interference signal taken by the linear image sensor, corresponding to the point A in FIG. 8 . The upper trace of FIG. 9 shows the digitized intensity at the points B in FIG. 8 . The closely packed lines are square waves of the 250 kHz master clock. The digitized intensity is set to 5 volt if the signal at the point A is higher than the pre-programmed threshold value and is otherwise set to zero. The digitized intensity then goes though two more logic stages to check the fringe width and the number of qualified fringes. If the signal satisfies all the three logic checks, an oil spillage warning signal is sent to a radio beeper for subsequent actions. All the electronics are commercial-grade, low-cost, and low-power integrate circuit chips, such as CMOS 4538B, 4047, 4040, 4064, 40174, and the like.
The threshold values are programmable through three reference voltages, subjected to the field conditions and the optical design. In general, the intensity threshold voltage value can be set at a value slightly higher than the background noise. The background noise is the signal voltage measured without the oil thin film. A preferred intensity threshold voltage is set 20% above the background noise. The upper limit of the intensity threshold voltage ought to be less than the signal voltage. Typically a signal-to-noise ratio larger than two is obtained. Optical design determines the threshold values of the fringe width and the number of fringes. For example, if the optics is designed such that the laser incident angle is 75 degrees and the laser beam has a full divergence angle of 10 degrees, the threshold value of the number of fringes can be ˜5 for a TM incident field, as indicated in FIG. 2 . It is assumed that the material parameters used in FIG. 2 are still valid for this example. The threshold value of the fringe width is approximately the multiplication of the fringe angular width and the distance between the imaging apparatus and the water surface. For example, near the 75-degree incident angle, the fringe angular width is about 1 degree in FIG. 2 and the fringe spatial width should be ˜5 mm for a 30-cm separation between the water surface and the imaging apparatus. If the interference fringes are primarily from wavefront-splitting interference, the threshold values can be inferred in a similar fashion.
In natural water, tidal waves may disturb the signal extraction in a buoyant optical system. If each measurement event is faster than the time constant of water motion, the water surface is considered static by the electronics circuit. Since the surface water wave usually conducts low-frequency motion, the 100 Hz data refreshing rate is adequate for most situations. If necessary, the 100 Hz data rate can be increased to avoid the problem of water motion.
Oil spillage with unleaded gasoline and engine oil in a water tank is experimentally simulated. The success rate of detecting oil spillage is nearly perfect. The image sensor array circuit performs equally well as does the CCD-LabView™ system. As an early warning system, this technique is designed to provide oil spill detection before the oil spreads into a large area. Occasional failure occurs when the engine oil forms a thick and smooth oil layer in the water tank. Under this circumstance, no water-oil interface is available to generate wavefront-splitting interference fringes, and the oil layer is too thick to generate well-separated thin-film interference fringes. However, small air bubbles are often present in the thick oil layer, which are in fact excellent scattering centers for generating wavefront-splitting interference fringes.
An optical early warning system for monitoring oil spillage has been successfully implemented according to the present invention. The system takes advantage of the thin-film interference and wavefront-splitting interference from the oil and water interfaces. In particular, the wavefront-splitting interference gives excellent fringe visibility even when the refractive indices of water and oil are close to each other. In addition, two detection systems, a CCD/LabView system and a sensor-array/logic-circuit system have also been tested. Both systems show excellent reliability and flexibility in discerning the interference fringes resulting from oil slicks. The sensor-array/login-circuit detection system is compact, low-cost, low power consuming, and can be installed in a stand-alone buoy with ease.
While the invention has been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures. Therefore, the above description and illustration should not be taken as limiting the scope of the present invention which is defined by the appended claims.
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An automatic, oil-spill-detection system, which employs thin-film and wavefront-splitting interference techniques to determines the existence of surface oil or oil drops in water is disclosed. Two independent automatic, decision-making systems are disclosed, which provide a reliable means for oil spillage detection. A computer code and a image extraction system are employed to discern and monitor the interference fringes generated from oil slicks. The computer-based imaging system can be further replaced by a compact and low-cost imaging circuit that functions reliably in a buoy with relatively low power consumption.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Application No. 62/292,389 entitled “FUNCTIONAL HARD CANDY OPTICS AND A METHOD FOR PRODUCING THE SAME” and filed on Feb. 8, 2016, the contents of which are incorporated by reference herein in their entirety.
FIELD OF THE DISCLOSURE
[0002] The present invention relates generally to optics. More particularly, the present invention relates to lenses, prisms, optical flats, and color filters constructed from hard candy, and the process of making the same.
BACKGROUND
[0003] Lenses, prisms, optical flats, and color filters (hereinafter collectively referred to as ‘optics’) are commonly used in laboratories and in equipment such as cameras, telescopes, magnifying glasses, and binoculars. The performance of an optic depends on three major characteristics: transparency in the spectrum of interest, shape, and refractive index.
[0004] In order for a material to be suitable for constructing an optic, it must absorb very little of the wavelengths it is intended to transmit—for example, a magnifying glass intended to be used by the naked eye should absorb very little of the visible spectrum. Suitable materials must also be able to hold a shape related to the intended function of the optic—for example, a plano-convex lens includes one flat and one convex surface, so a material may be suitable for constructing a plano-convex lens if the material can be formed into a shape with one flat and one convex surface. The refractive index of an optic determines how the path of a beam of light will be altered by the optic; a prism spreads white light into a rainbow due to each wavelength of the rainbow experiencing a different refractive index.
[0005] The quantitative traits of an optic, such as focal length and acceptance angle, are determined by a combination of the shape and the refractive index of the optic; a lower refractive index material uses a smaller radius of curvature to achieve the same focal length in a lens, and a higher refractive index material will result in a prism with a larger acceptance angle. Design constraints such as size or feasibility of construction may restrict what materials are valid for construction of an optic due to placing constraints on the refractive index.
[0006] Optics are usually constructed partially or entirely from a glass or plastic, or, less commonly, from a transparent liquid. These materials satisfy the three major characteristics listed above, and methods of constructing optics from these materials are widely known.
[0007] Although optics are present in many widely-used consumer products and technical equipment, the details of their construction and function are minimal or absent in most science curricula. This can, in part, be attributed to the fragility and cost of conventional optics; shattered glass poses a danger to students, and most optics are too expensive to be replaced frequently in classrooms. In addition, because glass and plastic require special training and equipment in order to form optics, children often do not participate in the construction process.
[0008] Cost and difficulty of manufacture can also cause projects requiring custom-built optics to be prohibitively expensive, especially when the project requires many optic components or when iterations of the project result in the destruction or obsolescence of one or more optics.
[0009] Some alternatives to glass and plastic exist that partially address the above problems for construction of optics. For example, gelatin lenses have recently gained popularity as an educational tool. However, gelatin deforms easily under its own weight, and so is not suitable for the construction of many types of optics. Gelatin is also delicate and very sensitive to motion, which further restricts its use to certain orientations. Gelatin is therefore not a valid material for the majority of optical equipment, interactive educational experiences, or scientific projects, which all usually utilize a wide range of shapes and orientations, tolerance for motion, and durability.
[0010] Some current methods of lens construction result in a lens that must be polished after the initial casting. In order for these methods to result in a lens suitable for optical applications, special equipment is required, increasing the time and cost of lens fabrication. Some current methods also destroy the mold used for casting the lens, limiting the consistency of lenses formed using these methods.
SUMMARY
[0011] A method of manufacturing a hard candy optic may comprise providing a mold, the mold comprising a depression; coating the depression with a lubricant; heating a mixture comprising either table sugar, light corn syrup, and water, or isomaltitol and water; pouring the mixture into the depression; cooling the mixture, wherein the cooling cures the mixture into the hard candy optic; and removing the hard candy optic from the mold.
[0012] A hard candy optic may comprise a lens comprising a first surface and a second surface, wherein the lens comprises an index of refraction of about 1.5 or about 1.63.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements.
[0014] FIG. 1 illustrates a perspective view of a hard candy optic in accordance with various embodiments.
[0015] FIG. 2 illustrates a cross-section view of the hard candy optic in accordance with various embodiments.
[0016] FIG. 3 illustrates plan view of a lens with hard candy handles in accordance with various embodiments.
[0017] FIG. 4 illustrates a hard candy optic in the shape of a prism in accordance with various embodiments.
[0018] FIG. 5 illustrates a mold for casting hard candy lenses in accordance with various embodiments.
[0019] FIG. 6 illustrates a mold for casting hard candy prisms in accordance with various embodiments.
[0020] FIG. 7 illustrates a flowchart of a process for manufacturing hard candy optics in accordance with various embodiments.
DETAILED DESCRIPTION
[0021] The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and their best mode. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the inventions, it should be understood that other embodiments may be realized and that logical, chemical and mechanical changes may be made without departing from the spirit and scope of the inventions. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation.
[0022] For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact.
[0023] Optics components, including lenses, prisms, optical flats, and color filters that are cheap, durable, safe, and of high enough optical quality to have real-world applications are disclosed herein. A wide variety of lenses, prisms, optical flats, and color filters with the above characteristics may be provided.
[0024] Optics made from hard candy may be manufactured using a method that results in consistent, optically-functional shapes. Hard candy may be a suitable material for optics. A method of preparing the hard candy may result in either clear or tinted optics, depending on the recipe. The entire fabrication process can be safely performed in the average home kitchen using common household items by anyone with rudimentary food preparation knowledge, making it both safe enough and simple enough to be used in educational settings.
[0025] Hard candy is a type of candy that does not deform under external pressure or its own weight. Optically-suitable hard candy is hard candy that is transparent in the appropriate wavelengths for the desired application of the optic. Optically-suitable hard candy is created by heating an appropriate mixture of sugars to a sufficiently-high temperature that the mixture will become hard when allowed to cool. The molten sugar mixture can then be shaped into its final form by pouring the mixture into appropriately-shaped molds and allowing it to cool.
[0026] Referring to FIG. 1 , a perspective view of a hard candy optic 100 is illustrated according to various embodiments. The hard candy optic 100 may comprise a lens 110 and a handle 120 . The lens 110 may generally comprise the shape of a circular disk. The lens 110 may comprise a first surface 112 and a second surface 114 . In various embodiments, the first surface 112 may be convex, concave, planar, cylindrical, spherical, axicon, or aspheric. Similarly, the second surface 114 may be convex, concave, planar, cylindrical, spherical, axicon, or aspheric. In various embodiments, the first surface 112 and/or the second surface 114 may be back-silvered with an edible reflective material, such that the lens forms a reflective mirror. In various embodiments, a non-edible reflective material, such as foil, may be coupled to the lens, and the reflective material may be removable. The combination of the shapes of the first surface 112 and the second surface 114 may control the path of light rays through or reflected by the hard candy optic 100 .
[0027] In various embodiments, the handle 120 may be coupled to the lens 110 in such a way that the optical performance is only slightly impaired. This results in an optically-functional confectionery. The handle 120 may be located at least partially within the lens 110 .
[0028] The handle 120 may allow the user to manipulate the hard candy optic 100 without leaving fingerprints or scratches on the optical surfaces. While some adults can be expected to have the caution and self-control necessary to avoid damaging or soiling an optic, children tend to be less careful. Thus, the handle 120 makes the hard candy optic 100 more suitable for educational use, as the optics are less likely to require cleaning or replacement during the lesson. In various embodiments, the handle 120 may comprise wood, hard candy, or a compressed paper or cotton material.
[0029] The handle 120 may transform the lens 110 into a popular form of candy, such as a lollipop. The lollipop shape may draw the attention of children, making them more willing to interact with the hard candy optic 100 . The shape may also allow instructors the option of treating the hard candy optic 100 as both an instructional tool and a reward.
[0030] Referring to FIG. 2 , a cross-section view of the hard candy optic 100 is illustrated according to various embodiments. In the illustrated embodiment, the first surface 112 may comprise a convex surface, and the second surface 114 may comprise a convex surface. The handle 120 may be located within a central region 116 of the lens 110 , the central region 116 being located between the first surface 112 and the second surface 114 . In various embodiments, the lens 110 may comprise a clear hard candy. However, in various embodiments, one or more portions of the lens 110 may comprise a colored tint. In various embodiments, differently colored regions of the lens 110 may allow a user to create different functions of the lens 110 as the hard candy optic 100 is consumed. For example, a first outer region 113 comprising the first surface 112 may be clear, the central region 116 may be clear, and a second outer region 115 comprising the second surface 114 may comprise a red tint. Thus, initially the lens 110 may have two convex surfaces and have a red tint. However, a user may consume the second outer region 115 until reaching a planar interface 118 between the central region 116 and the second outer region 115 , resulting in a clear lens with one convex surface 112 and one planar surface at the previous location of the planar interface 118 . Those skilled in the art will recognize that many different color combinations may be used to form lenses of various shapes.
[0031] Referring to FIG. 3 , a plan view of a lens 300 comprising hard candy handles 310 is illustrated according to various embodiments. The hard candy handles 310 may protrude from the edge of the optically functional portion of the lens 300 . The hard candy handles 310 may be formed in a molding process with the lens 300 , such that the lens 300 including the hard candy handles 310 form a single unitary component. The hard candy handles 310 may allow a user to hold and manipulate the lens 300 without smudging or scratching the optical surfaces of the lens 300 .
[0032] Referring to FIG. 4 , a perspective view of a hard candy optic 400 in the shape of a prism is illustrated according to various embodiments. The hard candy optic 400 may comprise a first optical surface 412 , a second optical surface 414 , and a third optical surface 416 . An angle between adjacent optical surfaces may be 60 degrees. The hard candy optic 400 may comprise a first end surface 422 and a second end surface 424 . The first end surface 422 and the second end surface 424 may each be triangular. The hard candy optic 400 may separate white light into a rainbow due to each wavelength of the rainbow experiencing a different refractive index in the hard candy optic 400 .
[0033] Referring to FIG. 5 , a perspective view of a mold 500 for hard candy optics is illustrated according to various embodiments. The mold 500 may comprise one or more depressions in a face 501 of the mold 500 which may be used to form hard candy optics of various shapes. For example, the mold 500 may comprise a concave spherical depression 510 that can be used to produce a convex lens, such as a plano-convex lens. The mold 500 may comprise a concave cylindrical depression 520 that can be used to produce a convex cylindrical lens. The mold 500 may comprise a channel 522 connecting the edge 502 of the mold 500 to the concave cylindrical depression 520 , allowing for the creation of a hard candy handle, or for the incorporation of an element such as a wooden or paper handle, or for the filling of the mold when the face 501 containing the depression is inaccessible. The mold 500 may comprise a cylindrical depression 530 with a convex lower surface 532 . The cylindrical depression 530 may be used to produce a concave lens.
[0034] The mold 500 may comprise a solid piece of material that contain depressions in the shape of the negative of the final desired form of one or more hard candy optics. The mold 500 may be formed by imprinting, vacuum-forming, or mass-removal, and can be constructed from any material that can withstand the casting process. In the case of reusable hard candy optic molds, suitable materials include, but are not limited to, silicone, plastic, and metal. In various embodiments, the material of the mold 500 may be able to withstand temperatures of 275° F. without deforming or breaking and may not react with sugar.
[0035] In various embodiments, the mold 500 may comprise silicone. The mold 500 may be created using an initial template. The template may comprise solid objects of the desired shape of hard candy optics affixed to the bottom surface of a container such that mild force will not cause the objects to shift. The walls of the container may be at least 0.25 inches taller than the highest point of any object used in the template. The objects and container may all be impermeable to uncured (liquid) silicone. The objects may be glass or plastic optics, any object with an optically-suitable form, or objects of any other form that facilitate the fabrication of hard candy optics (such as lollipop sticks). Uncured silicone may be poured into the container until all objects are covered by at least 0.25 inches of silicone. The silicone may then be cured according to the type of silicone used. Possible curing methods include, but are not limited to, temperature-based curing, light-based curing, and time-based curing. Depending on the silicone used, the uncured silicone may be degassed before curing to remove air bubbles. Once the silicone is cured, it may hold the shape of the template when relaxed, but can be temporarily deformed to facilitate removal from the template or release of molded objects.
[0036] In various embodiments, the mold 500 may comprise plastic. The mold 500 may be formed using a similar template to the silicone mold process, but the objects may be affixed to a flat screen with no walls. The objects and screen may be able to withstand temperatures above the sag temperature of the plastic being used. Using a vacuum, air may be sucked from under the screen. A sheet of plastic may be heated until the plastic begins to deform under its own weight. The hot plastic is then draped over the template such that the plastic deforms into the shape of the objects, pulled against the objects by the vacuum to ensure faithful reproduction of the forms of the objects. The plastic is then allowed to cool. Once the plastic is cool, it permanently holds the shape of the template, but can be slightly deformed to facilitate removal from the template or release of molded objects.
[0037] In various embodiments, the mold 500 may comprise metal. The mold 500 may be formed by removing material from the surface of a piece of metal until the depression approximates the negative of the desired optic shape. The depression may then be polished. The smoother the depression, the smoother the surface of the resulting hard candy optic, and thus, the more light transmitted by the optic.
[0038] Although the silicone and plastic molds may be unsuitable for creating glass and plastic lenses due to the temperature requirements for creating glass and plastic lenses, the silicone and plastic molds may be capable of withstanding the temperature of liquid candy used to create hard candy optics.
[0039] Referring to FIG. 6 , a perspective view of a mold 600 for forming hard candy optics in the shape of prisms is illustrated according to various embodiments. The mold 600 may comprise a depression 610 in the shape of the negative of a Littrow prism. The mold 600 may comprise a depression 620 in the shape of the negative of a Dove prism. The depressions 610 , 620 may be used to produce Littrow and Dove prisms, respectively.
[0040] Referring to FIG. 7 , a flowchart 700 of a method of manufacturing a hard candy optic is illustrated according to various embodiments. The method may comprise providing a mold (step 710 ). If the desired hard candy optic should have one large, flat face, a single mold may be used. If the desired optic has no large, flat faces, two or more molds can be sandwiched together with a channel allowing for the mold to still be filled.
[0041] The mold may be coated with a lubricant (step 720 ). In various embodiments, only the depressions are coated. However, in various embodiments the entire mold may be coated. For a silicone mold, the mold may be coated with a thin layer of vegetable oil to prevent bubbles from forming within the hard candy optic as it cools. If the mold is left uncoated, the molten candy may heat air trapped within the silicone, causing the air to expand into the molten candy and create bubbles along the mold-candy interface. These bubbles may reduce the optical quality of the optic and create differences in behavior between optics made from the same mold.
[0042] For a plastic or metal mold, the mold may be coated with a thin layer of vegetable oil to facilitate the release of the hard candy optic from the mold. If the mold is left uncoated, the surface of the hard candy optic may become stuck to the mold after cooling. This may result in parts of the optic deforming or breaking while being separated from the mold, reducing consistency and optical quality of the optic.
[0043] Vegetable oil is nearly transparent to visible light, edible, cheap, and safe to use without special training or equipment, so the existence of a thin film of vegetable oil on the surface of a hard candy optic may not substantially change the performance, price, or applications of the optic. While vegetable oil is one type of lubricant used to manufacture hard candy optics due to its availability, other substances may also be suitable for mold preparation.
[0044] In various embodiments, a handle or other rigid object may be placed in the mold (step 730 ). A lollipop stick, screw, or other additional element can be incorporated into the hard candy optic to allow for easier manipulation and use of the optic. The mold may comprise space for the rigid object in the mold, and the rigid object may be positioned in the designated space before pouring the molten candy into the mold. The molten candy may surround and bind to the object, securely incorporating the object into the final hard candy optic.
[0045] A molten candy mixture may be prepared (step 740 ). Pure sucrose (table sugar) may not result in optically-suitable hard candy, due to the sucrose rapidly crystallizing during the cooling process; crystalline sucrose is opaque in the visible spectrum. However, adding glucose or fructose to sucrose may prevent crystallization of the sucrose, resulting in hard candy with only minor absorption across the visible spectrum. Sucrose-based optics may be prepared by combining two parts table sugar, one part light corn syrup, and one part distilled water over high heat. The sugars may dissolve in the water, preventing burning by allowing the heat to distribute more evenly throughout the mixture. As the temperature rises, the water will boil away, leaving a sugar mixture that is less than 1% water by volume. Once the temperature of the mixture reaches 303° F. (as measured by, for example, a candy thermometer or rapid cooling of a drop of mixture), the container may be removed from the heat source and partially submerged in cold water to prevent the temperature of the mixture from continuing to increase. If coloring or flavoring is desired, the dyes or flavorings are added immediately after the container is removed from the water and thoroughly stirred into the mixture. The mixture may then be uniformly held at 275° F. (by, for example, placing the container in an oven) for five minutes to eliminate air bubbles introduced by the boiling process. If no color is added, this method results in transparent optics with a slight golden tint and an index of refraction of about 1.5, similar to that of popular optical glasses. As used herein, “about” refers to +/−5%.
[0046] In various embodiments, isomaltitol may be used as an alternative to the above sucrose, fructose, and glucose mixture. Isomaltitol is a mixture of two parts glucose, one part mannitol, and one part sorbitol. Isomaltitol-based optics may be formed by combining three parts isomaltitol and one part distilled water over high heat. Again, the water will boil off as the temperature of the mixture rises. Once the temperature of the mixture reaches 333° F., the container is removed from the heat source and partially submerged in cold water to prevent the temperature of the mixture from continuing to increase. If coloring or flavoring is desired, the dyes or flavorings are added and thoroughly stirred into the mixture immediately after the container is removed from the water. The mixture is then uniformly held at 275° F. for five minutes. If no color is added, this method results in optics with very similar transparency to clear glass and an index of refraction of about 1.63.
[0047] Isomaltitol, unlike table sugar and light corn syrup, cannot be purchased in typical grocery stores. Optics made from isomaltitol are approximately twice as expensive as optics made from table sugar and light corn syrup, and exhibit superior resistance to humidity-catalyzed surface crystallization.
[0048] The preferred optic composition depends on the desired application of the optic; sucrose-based optics are generally suitable for recreational and educational activities involving small children, while isomaltitol optics are recommended for prototyping and experimental applications. Alternative compositions of hard candy can be evaluated for suitability using the criteria of transparency, refractive index, and cost.
[0049] The molten candy may be poured into the mold (step 750 ). The mixture is then allowed to cool for twenty minutes (step 760 ). Once the molten candy is cured, the hard candy optics may be removed from the mold in the form of a finished hard candy optic. In various embodiments, the described methods result in a hard candy optic in which no polishing or reshaping is required, which is an improvement over existing methods for creating hard candy lenses or glass optics. The finished hard candy optic may be used to conduct optical experiments, eaten, or wrapped for future use.
[0050] The disclosed methods may also be suitable for creating optics with features that are not optically relevant, but expand the applications of the optic. An appropriate mold will result in an optically functional hard candy optic with handles of additional material around the edge of the optic, allowing the optic to be securely held without impairing its optical properties. In various embodiments, a mold may comprise features that result in a hard candy optic with a threaded rim, allowing the optic to be screwed into a holder without incorporating additional elements.
[0051] The disclosed ingredients and processes are substantially cheaper than those of existing mass-produced optics, resulting in individual optics that may cost approximately one-tenth or less than the price of equivalent off-the-shelf optics. The disclosed processes may be nondestructive and scalable, which allows for even lower costs due to economies of scale. In various embodiments, the process may be completed in less than thirty minutes. This combination of cost and speed make the disclosed hard candy optics suitable for mass production and rapid prototyping applications.
[0052] Those skilled in the art will recognize that a wide variety of hard candy optics may be produced according to the present disclosure. For example, this method can produce lenses including, but not limited to, bi-convex, bi-concave, plano-convex, plano-concave, cylindrical, axicon, and aspheric lenses. In addition, this method can produce prisms in any shape currently sold by major optics suppliers, with similar size constraints to existing products. Standard optical flats and color filters can also be produced using this method.
[0053] While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
[0054] Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
[0055] Methods and systems are provided herein. In the detailed description herein, references to “one embodiment,” “an embodiment,” “various embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
[0056] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
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Functional optical equipment such as lenses, prisms, optical flats, and color filters are made from hard candy, resulting in working optics that can be treated as either experimental equipment or confectionaries. These hard candy optics are manufactured by an extremely precise casting process, which avoids the need to polish or reshape the candy after casting and allows for the production of a wider selection of optical equipment. This process also allows the inclusion of features that expand the applications of the hard candy optics, but are not themselves optically functional.
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BACKGROUND OF THE INVENTION
The present invention relates to systems for pumping liquids under relatively high pressures. More particularly, the invention relates to a portable system for pumping liquids, wherein liquid pressure is regulated by a transducer which develops electrical control signals for controlling an electric motor drive source.
The present invention is primarily adaptable for use with portable high-pressure spraying systems for spraying coating materials such as paint and the like. However, the invention is also adaptable for use in connection with any high-pressure liquid spraying system, particularly of a portable nature wherein the driving force is an electrical motor or equivalent. Portable spraying systems of this general classification are known in the art, and are generally typified by an electrical motor drive source which is mechanically linked to drive a reciprocable pump, wherein the liquid pressure is controlled by a pressure transducer coupled to an electric motor switching circuit. The pressure transducer monitors the liquid output pressure from the pump, and controls a switching circuit which applies an electrical driving voltage to the motor when the monitored pressure drops below a predetermined or preset amount, and provides a motor shut-off control signal whenever the pressure exceeds a predetermined or preset higher value.
Portable pumping systems of the type generally related to the present invention are disclosed in U.S. Pat. No. 4,009,971, issued Mar. 1, 1977, and U.S. Pat. No. 4,397,610, issued Aug. 9, 1983. The '971 patent discloses a portable pumping system having a positive on/off motor control, wherein a pressure transducer is connected into a liquid manifold and may be preset to a predetermined pressure which causes the transducer to activate an electrical switch for controlling power delivered to the motor. The '610 patent discloses a variable speed motor utilizing a pressure transducer to generate a variable drive voltage to the motor, to slow down and speed up the drive motor in response to pressure fluctuations. Various forms of pressure transducer have been developed for use in connection with pumps of the general type associated with the present invention. For example, U.S. Pat. No. 4,212,591, issued Jul. 15, 1980, discloses a pressure transducer which senses the expansion and contraction of a flexible pressure hose as a means for determining liquid pressure. The U.S. Pat. No. 4,335,999, issued Jun. 22, 1982, discloses a further variation of the flexible hose sensing mechanism. U.S. Pat. No. 4,323,741, issued Apr. 6, 1982, discloses a Bourdon tube construction wherein the deflection of the Bourdon tube causes a switch activation to occur. The aforementioned '971 patent discloses a pressure transducer comprising a slidable piston rod responsive to pressure, the piston rod having a threadable knob at its distal end, the knob being engageable against a pin which is movable to contact a switch lever. Each of the foregoing patents disclose various forms of reciprocable drive liquid pumping cylinders having an output liquid delivery line coupled to a pressure sensor, via either a simple manifold or liquid flow-through device, and an output delivery line coupled to the pressure sensor mechanism.
SUMMARY OF THE INVENTION
The present invention comprises a portable reciprocable drive pumping system having a liquid manifold affixed directly to the pumping cylinder, the manifold receiving pressurized liquid delivered from the cylinder, a pressure transducer coupled into a liquid delivery chamber in the manifold, with an adjustable pressure setting device linked to the pressure transducer, and a pressure relief valve system also coupled to the manifold chamber. The single manifold therefore accommodates all of the liquid delivery, pressure setting and pressure relief functions of the portable pumping system. The pressure transducer and pressure setting mechanism includes a slidable piston in liquid contact in the manifold, the slidable piston having a projecting stem which engages a spherical bearing, the bearing also engaging a spring-loaded push rod located in an adjacent housing, the push rod being engageable into movable contact against a switch lever, the switch lever controlling a switch for switching electric motor power on/off.
It is the principal object of the present invention to provide a portable reciprocable drive pumping system having all of the liquid delivery functions confined to a compact unit.
It is another object of the present invention to provide a single manifold directly connected to a reciprocable piston and cylinder, the manifold housing all of the pressure delivery, sensing and relieving functions for the system.
It is a further object of the present invention to provide a pressure transducer in direct liquid contact within the manifold chamber, the transducer being externally linked to a movable bearing surface.
It is yet another object of the present invention to provide a pressure control mechanism linked to the aforesaid movable bearing surface, and coupled to a power switch, all of which are external to the liquid delivery components of the system.
The foregoing and other objects and advantages of the invention will become apparent from the following specification and claims, and with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of a portable pumping system of the type associated with the present invention;
FIG. 2 shows an isometric view of the liquid delivery components of the invention;
FIG. 3 shows a partially exploded view of the manifold of the present invention, including associated and connected components;
FIG. 4A shows a cross-sectional view of the pressure control mechanism taken along the lines 4A--4A of FIG. 3; and
FIG. 4B shows a cross-sectional view of the pressure transducer of the invention, taken along the lines 4B--4B of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, the portable pumping system 10 of the present invention is shown in isometric view. A drive motor 12 is mounted on a portable stand 11 which is movable by a handle 13. The drive motor 12 is mechanically connected via a gear box 14 to drive a reciprocable pump 16. The reciprocable pump 16 is connected to a manifold 22 for receiving the liquid delivered by the pump 16. A suction hose 18 is connected to the pump 16, for insertion into a container of the liquid being pumped. A liquid drain hose 20 is connected to the manifold 22, and is controllable by a drain knob 26, to relieve pressurized liquid into the drain hose 20, which is typically placed into the same container as the suction hose 18. A pressure adjustment knob 24 is connected to the manifold 22 for providing a preferred delivery pressure setting.
FIG. 2 shows an isometric view of the liquid delivery components of the present invention. The liquid delivery components are affixed to the gear box 14 which has a projecting crankshaft 15 coupled to a connecting rod 17, which is coupled to a piston rod 17a. The piston rod 17A is reciprocable within a cylinder 19 to form the pump 16. The pump 16 has a liquid delivery passage (not shown) coupled directly into manifold 22. A liquid outlet 28 is connected to a liquid delivery hose 29 and also coupled to manifold 22, and pressure adjustment knob 24 is attached to a pressure-sensing mechanism 25 which is also affixed to gear box 14 and is coupled via a pressure transducer into manifold 22. The manifold 22 is preferably bolted to the underside of the gear box 14 housing.
FIG. 3 shows an isometric and exploded view of the liquid delivery components of the invention. Manifold 22 forms a common housing for mounting all of the components associated with the liquid delivery function. For example, pump 16 is affixed to an opening in the bottom of manifold 22, liquid outlet 28 is affixed to an opening through one side of manifold 22, drain valve 27 is affixed into an opening on another side of manifold 22, and pressure transducer 30 is inserted into a further opening in manifold 22. The pressure setting mechanism 25 is attached to a switch box 32 and a push rod 34 projects from the underside of switch box 32 to engage the movable components of pressure transducer 30, to be hereinafter described. A liquid delivery hose 29 may be connected to liquid outlet 28 for delivering the pumped liquid over extended distances, as for example to a spray gun or the like.
Drain valve 27 is threadably affixed into manifold 22, and has a valve rod 31 projecting externally therefrom. Valve rod 31 extends through an opening in switch detent cover 35, and is secured to drain knob 26 by means of a pin or other locking mechanism. Switch detent cover 35 has two detent positions to identify preferred positions for drain knob 26, the two positions being at different elevations, so as to pull valve rod 31 outwardly from drain valve 27 when knob 26 is rotated to one of these positions. The outer surface 41 of switch detent cover 35 provides the necessary grooved detent surfaces and the raised surface for pulling valve rod 31 outwardly when knob 26 is rotated.
FIG. 4A shows a cross-sectional view of the pressure setting mechanism 25 which is coupled to the pressure transducer 30, and FIG. 4B shows a cross-sectional view of pressure transducer 30. Pressure transducer 30 is sealably inserted into an opening in manifold 22, so as to expose the bottom opening 36 of pressure transducer 30 to the interior of manifold 22. A slidable piston 38 is therefore exposed to the internal liquid pressures within manifold 22, and piston 38 is movable along vertical axis 37 in response to pressure variations within manifold 22. Pressure transducer 30 is not threadably attached to either manifold 22 or gear box housing 14, and is therefore free to move along axis 37 to a position which is determined by mechanical contact of the top surface 54 against the housing comprising gear box 14. Fluid pressure acting against O-ring seal 56 provides a liquid seal preventing liquid in manifold 22 from escaping through the pressure transducer bore. The positive stop afforded by the housing for gear box 14 assures that pressure transducer 30 will always be positioned at the same point along axis 37, thereby simplifying calibration procedures whenever the unit is disassembled for service or repair.
Piston 38 has a projecting rod 39 which is slidable but sealably projecting into an upper housing 40 of transducer 30. A spherical ball 42 rests atop the end of rod 39 and is movable therewith. Upper housing 40 has an interior bore 43 which is sized slightly larger than the diameter of ball 42, so as to permit ball 42 to freely move upwardly and downwardly. The interior of bore 43 is wholly isolated from liquid contact, suitable O-rings and packings being utilized to prevent liquid flow from manifold 22 into bore 43. A leakage passage 55 is provided through upper housing 40 in the event the seal provided by the piston fails.
Pressure setting mechanism 25 is mounted generally along axis 37 in endwise alignment with pressure transducer 30. Pressure adjustment knob 24 is connected to a stem 23 which is threadably insertable into one end of a housing 44. A compression spring 45 is supported in the inner end of stem 23, and a spherical ball 46 is supported at the other end of the compression spring 45. Push rod 34 has a first end contacting spherical ball 46, and a second end contacting spherical ball 42. The range of travel of push rod 34 along axis 37 is limited by a shoulder stop 47 on push rod 34. Stop 47 is confined within switch box 32 by a calibration nut 48, which adjustably positions shoulder stop 47 along axis 37.
A microswitch 51 is mounted inside of switch box 32, and microswitch 51 has an actuator button 50 which is movable by contact with flange 60 on push rod 34. Wires 33 are connected to microswitch 51, so as to provide a switch connection between the "common" terminal and the "normally open" (NO) terminal in one switch position, and between "common" and the "normally closed" (NC) terminal in the other switch position. The signals produced by switch 51 are utilized to drive further electric circuits which turn on and turn off the electric drive motor 12.
Because push rod 34 transfers its linear motion along axis 37 via spherical ball bearings 42 and 46, axial alignment of all of the components is not a critical requirement. Push rod 34 may be axially misaligned relative to rod 39, and push rod 34 may be axially misaligned relative to housing 44 and compression spring 45. The respective spherical balls 42 and 45 engage push rod 34 via respective conical depressions in the ends of push rod 34. This mechanical linkage and coupling mechanism greatly reduces the frictional forces which might otherwise be caused by misalignment of the respective components.
In operation, knob 24 may be threadably adjustable into and out of housing 44, so as to increase and/or decrease the compression force of a spring 45, which acts against ball 46. This compression spring force urges push rod 34 downwardly against ball 42, and the force is transferred further downwardly against rod 39 connected to piston 38. When the liquid pressure within manifold 22 rises to a sufficient level, it acts against the spring force of spring 45 to move push rod 34 upwardly. Flange 60 also moves upwardly, and at some pressure level the flange 60 releases switch button 50 and causes switch button 50 to switch the microswitch 51. This switch action generates an electrical signal which is coupled through circuitry to turn the drive motor 12 off. As the liquid pressure within manifold 22 decreases, push rod 34 and shoulder flange 60 move downwardly, thereby depressing switch button 50, causing microswitch 51 to switch back into its initial position. Microswitch 51 may be selected from any of a number of well-known commercially available switches, as for example Switch Type V3, manufactured by the Microswitch Division of Honeywell.
Pump 16 acts as a conventional double-acting reciprocable pump, delivering pressurized liquid into manifold 22 during both the pressure stroke and suction stroke portions of its pumping cycle, and this pressurized liquid is passed into a liquid delivery line via outlet 28.
Drain valve 27 may be actuated at any time to relieve liquid pressure from within manifold 22. When the drain knob 26 is rotated to a first position drain valve 27 is caused to pass liquid from manifold 22 into drain hose 20; when knob 26 is placed in a second position, valve 27 is closed and prevents such liquid passage. Drain valve 27 is particularly useful for relieving static liquid pressure buildup which may be retained in manifold 22 after the pump has been operated for some period of time and then shut off. Drain valve 27 may also be used as a cooperating element in the function of priming the pump for initial operation. Drain valve 27 also operates as a safety relief valve, because valve element 53 may be forced open whenever the pressure within manifold 22 exceeds the force of compression spring 52. The spring force may be preset to permit drain valve 27 to operate as a safety relief valve at some preset pressure limit.
Manifold 22 and its associated components are readily removable from the overall device by merely disconnecting the two bolt fasteners which affix the manifold to the underside of the gear box 14, thereby providing for swift and easy maintenance and repair.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.
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A self-contained liquid manifold attachable to a drive mechanism for a reciprocable pump, the manifold having a pumping cylinder, pressure transducer, pressure control mechanism, drain valve and control mechanism attached thereto, and liquid delivery outlets all forming a part thereof. The manifold and its associated components are removable from the reciprocable drive mechanism by detaching two fasteners. The pressure transducer and control mechanism includes a piston and cylinder removably indexed in a manifold bore, and an electrical switch in an adjacent housing with a ball bearing on the piston and a push rod resting on the ball bearing, the other push rod end constrained by a ball and spring combination.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to ball joints for showerheads. More particularly it relates to the provision of an air induction system associated with such ball joints to heighten the perceived water volume.
[0004] Primarily for water conservation reasons the flow rate to conventional showerheads has been restricted. However, this can lead a consumer to perceive the shower as being less forceful than desired.
[0005] It is known in connection with a variety of faucets and showerheads that aerating the water stream can make a given volume of water flow appear more bulky and substantial. Hence, aerating systems are often attached to the outlet of a faucet spout, and sometimes integrated into a showerhead. See e.g. U.S. Pat. Nos. 6,471,141 and 6,796,518 and U.S. patent application publications 2004/0199995 and 2007/0158470.
[0006] However, associating the aeration system with the showerhead itself, or the faucet spout, can disrupt the aesthetics, and in some cases can add complexity to the manufacturing of the product. One such aerating low-flow showerhead accomplishes this through a variety of moving parts. Further, associating the aeration system with the showerhead itself does not provide a solution for aerating the millions of existing showerheads which don't have this capability.
[0007] Hence, there were attempts to place the aeration system on a separate ball joint upstream of the showerhead, which would be hidden by the showerhead. See e.g. U.S. Pat. Nos. 5,111,994, 5,154,355 and 6,260,273, and U.S. patent application publication 2007/0193153. The approach used in these designs was to place a radial air inlet at the ball joint, and associate it with a venturi passage so as to induce air into the water flow in the joint. In this regard, as water passes through a throat of the venturi, the water velocity increases and the pressure decreases. The resulting negative pressure draws in ambient air through the radial inlet. The air then mixes with the water to produce an aerated water supply.
[0008] These ball joint-related designs are not without their own drawbacks. For example, their air inlet ports are nothing more than uncovered holes formed in the water supply line. This creates the possibility of water leaking back out the air inlet, creating a path for water waste, spitback, or water spray into the main bath area. Further, designs of this type can create undesirable noise such as a whistling or a roaring sound.
[0009] Hence, a need still exists for improved ways to aerate showerhead flow while avoiding these problems.
SUMMARY OF THE INVENTION
[0010] The present invention provides a joint connector for linking a water supply to a showerhead. The joint connector has a housing having an inlet section at one end suitable to connect to a water supply pipe, an outlet section at an opposed end suitable to mount the showerhead thereon, and a central portion there between. There is a passageway extending axially through the housing from the inlet section, through the central portion, and through the outlet section. The passageway is suitable to carry water there through, and a portion of the passageway in the central portion forms a venturi.
[0011] There is also an air inlet port positioned in the central portion and extending radially from the passageway to an exterior wall of the housing so as to be suitable to let air pass through the air inlet port into the housing. Further, an insert positioned within the air inlet port (e.g. to provide one-way flow and/or to reduce noise).
[0012] In preferred forms of the invention the insert is in the form of a check valve that permits air flow through the inlet port into the passageway, but restricts reverse flow from the passageway through the inlet port. One such check valve is an elastomeric duckbill check valve.
[0013] Surprisingly it has been found that this type of check valve greatly reduces noise associated with the joint while still controlling reverse flow through the air inlet. A particularly desirable placement for the intersection between the air inlet and the passageway is the throat of the venturi. Alternatively, noise reduction without check valve function can be obtained by using a cylindrical/sleeve form insert.
[0014] Various refinements are also possible such as having the inlet section provided with a flat area on its upper exterior which extends to the air inlet port (to provide a hidden position for the insert), providing the inlet section with interior threads (to facilitate linkage to a water supply pipe), and providing the outlet section with a generally ball-shaped exterior (to facilitate mounting a showerhead for essentially universal pivoting).
[0015] In another aspect the invention provides a showerhead mounted on such a joint connector.
[0016] In some forms the passageway can have in the central section a portion that narrows in a conical fashion. This then leads to a narrowed cylindrical section to define a venturi throat. Water flowing through the passageway obtains a higher velocity through the throat than upstream of the throat. The passageway then expands sharply downstream of the throat. This causes a pressure drop at the throat, causing air to be sucked in past the insert. The air becomes mixed with the water supply to create the aerated water stream.
[0017] It will be appreciated from the following description and the drawings that the present invention provides a number of advantages. First, because the air induction occurs at the ball joint, millions of existing showerheads can be retrofitted with this type of ball joint instead of the one they currently use. Hence, aeration can be provided for them.
[0018] Also, there is no spurting or leaking of water back out the air inlet port. Also, the air inlet port and associated insert are essentially hidden from view.
[0019] Further, the problem of noise due to air induction is overcome. Moreover, all these advantages can be obtained without materially increasing the cost of a standard ball joint.
[0020] These, and still other advantages, can be obtained with the present invention. While preferred embodiments are described below, the claims should be looked to in order to judge the full scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a side elevational view of a joint connector of the present invention linking a water supply pipe and a showerhead;
[0022] FIG. 2 is an exploded perspective view of the joint connector of FIG. 1 ; and
[0023] FIG. 3 is a cross sectional view taken along line 3 - 3 of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Ball joint connector 10 is shown threaded onto a conventional water supply line 12 . The ball joint connector 10 has a generally tubular outer housing which has an inlet portion 14 and an outlet portion 16 which is generally ball-shaped. The intermediate portion there between houses an internal venturi and an air inlet port 34 , as well as an axially extending passageway 18 .
[0025] A passageway inlet 20 is located at an upstream end of the ball joint connector 10 , and a passageway outlet 22 is located at the opposing downstream end. When installed as shown in FIGS. 1 and 3 , the passageway 18 carries water from the water supply line 12 to a conventional showerhead 24 .
[0026] The ball joint connector 10 , apart from the insert 40 , is preferably made of a metal such as brass. Standard internal threads 26 are provided in the passageway inlet 20 and are designed to threadingly engage the water supply line 12 . The showerhead 24 can be movably secured to the outlet portion 16 in a known manner so as to be easily swiveled (compare the mounting system of U.S. Pat. No. 6,796,518).
[0027] The passageway 18 includes a venturi entry section 28 that provides a taper (preferably conical) to speed up the flow through a venturi throat 30 . Downstream of the venturi throat 30 , the passageway 18 has a venturi exit cone 32 to expand flow outwardly. The passageway 18 may further include a pocket section within which a flow regulator and/or a filter screen may be placed. The passageway 18 may further include a pocket section within which a flow regulator and/or filter screen may be placed.
[0028] When water flows through the passageway 18 , the reduction provided by the venturi entry cone 28 , throat 30 , and exit cone 32 causes the velocity of the water to increase and the pressure to decrease. This phenomenon is well known in the art and often referred to as the Bernoulli principle.
[0029] The ball joint connector 10 has a radially extending air inlet port 34 . An elastomeric insert in the form of a duck bill type check valve 36 is situated within the air inlet port 34 . The reduced water pressure in the venturi throat 30 is less than the pressure of the ambient air when water is rushing through the ball joint connector 10 . Due to the resulting pressure difference, ambient air is drawn into the passageway 18 through the air inlet port 34 and becomes inducted, or entrained, into the water stream contained therein.
[0030] The air inlet port 34 as shown extends transversely between the water supply passageway 18 and a flat outer upper surface portion 38 of the ball joint connector 10 . Alternatively, the air inlet port 34 may extend at an acute angle. The flat outer upper surface portion 38 also facilitates use of a gripping wrench. When installed as shown in FIG. 3 , an inlet end 46 of the check valve 36 is flush with the flat outer upper surface portion 38 .
[0031] Still referring to FIG. 3 , the air inlet port 34 joins the passageway 18 at the venturi throat portion 30 . The entry point of the air inlet port 34 could alternatively be formed in other locations in the passageway 18 .
[0032] In the embodiment shown, the elastomeric check valve 36 is force fit into the air inlet port 34 and through which air flows into the passageway 18 . The check valve 36 permits the flow of air into the passageway 18 while preventing water (or air) from discharging out of the passageway 18 . The preferred check valve design, as shown in FIGS. 2 and 3 , is commonly referred to as a “duckbill” valve because its outlet end 42 has a pair of lips 44 that taper like the bill of a duck.
[0033] The check valve 36 has a cylindrical flange at its inlet end 46 configured to fit snugly within the air inlet port 34 . A central bore 48 extends completely through the check valve 36 . Air drawn into the bore 48 acts to drive the flexible tapered lips 44 apart, thereby permitting air flow into the passageway 18 . Pressure applied against the outlet 42 of the check valve 36 acts to drive the lips 44 closed and prevent reverse flow through the check valve 36 .
[0034] When first starting a shower, the check valve 36 prevents the initial surge of water from discharging out of the air inlet port 34 . Similarly, if the venturi-induced vacuum is interrupted, such as by air trapped in the line, the potential exit path provided by the air inlet port 34 is blocked by the one-way nature of the check valve 36 .
[0035] Surprisingly, the check valve 36 further acts to substantially reduce the level of noise. If the ball joint connector were used without an insert such as check valve 36 , a shrill whistling or roaring noise is oftentimes produced. The noise level has been measured as high as ninety-five decibels just outside of the air inlet port 34 .
[0036] However, it has been found that by placing a small sleeve-like insert within the air inlet port 34 , the noise emanating from the ball joint connector 10 can be greatly reduced. It is believed this is occurring because a flexible sleeve absorbs and limits the sound waves, while still permitting air passage.
[0037] It should be appreciated that merely preferred embodiments of the invention have been described above. However, many modifications and variations to the preferred embodiments will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. For example, the insert could be a rubber cylindrical sleeve, rather than a rubber or other elastomeric check valve. Therefore, the invention should not be limited to the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced.
INDUSTRIAL APPLICABILITY
[0038] The invention provides a ball joint-type connector for linking a showerhead to a water supply pipe, where the connector provides aeration function with reduced noise and water waste.
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A ball joint connector is provided for linking a showerhead to a water supply pipe. The connector has an internal venturi that draws air into the connector to aerate water being provided to the showerhead. An insert such as a check valve is provided in a radial air inlet connected to the venturi. The insert prevents spraying or leaking out the air inlet, while reducing noise associated with the air induction.
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This is a Divisional of application Ser. No. 08/664,442 filed Jun. 21, 1996, now abandoned.
This invention relates to composite framing members, more specifically to studs and tracks, joists and bands, headers, and rafters formed from wood and metal composites.
BACKGROUND AND PRIOR ART
Residential and light commercial construction generally use wood as the primary building material for studs, plates, joists, headers and trusses. However, all-wood construction has problems. The rapidly rising cost of raw wood supplies has in effect substantially raised the cost of these members. Further, the quality of available framing lumber continues to decline. Finally, wood is flammable and susceptible to insects and rot.
Due to these problems, many builders have been switching to using all steel framing. The costs between using wood or steel framing is getting closer. In January 1990, the cost of framing lumber was about $225 per thousand board feet, peaking to highs of $500 in both January, 1993 and January 1994. Since June 1995, the framing lumber composite price has been rising from $300 per thousand board feet. Estimates from the AISI and NAHB Research Center state at a framing lumber cost of $340 to $385, there would be no difference between the cost of framing a house in steel as compared in wood. Thus, the break-even point between wood and steel framing is at about $360 per thousand board feet of framing lumber, and the lumber price has exceeded that point several times in recent years by as much as 40%, giving steel a competitive advantage.
Recycling has additionally helped the cost of steel to remain on a stable or downward trend. Steel costs have varied little in recent years. Traditionally variations can be correlated to steel demand by the automobile industry when demand is high, steel usually increases slightly in price. Consequently, the use of metal framing in residential and light commercial construction is increasing, a trend recognized and encouraged by the American Iron and Steel Institute (AISI).
All steel studs, tracks and trusses are being manufactured by Tri-Chord, HL Stud Corporation, Truswall Systems, Techbuilt Manufacturing, Knudson Manufacturing, John McDonald, and MiTek Ultra-Span Systems.
A problem with using all steel framing is its high thermal conductivity, leading to thermal bridging, "ghosting", and greater potential for water vapor condensation on interior wall surfaces. "Ghosting" is when an unsightly streak of dust accumulates on the interior wallboard, where the steel studs lie behind, due to an acceleration of dust particles toward the colder surface. Another problem of using all steel framing is the increased energy use for space conditioning (heating and cooling). Metal used for exterior framing members allows greater conduction heat transfer between the outside and inside surfaces of a wall, roof or floor. In colder climates, this increased conduction can cause condensation in interior surfaces, contributing to material degradation and mold and mildew growth. Metal framing also decreases the effectiveness of insulation installed in the cavity between the metal framing due to increased three dimensional thermal shorting effects. Higher sound transmission is another disadvantage of metal framing since sound conductivity is greater in metal than in wood. Electricians have more difficulty working with all steel framing when running holes for wiring since metal is more difficult to drill than wood, and grommets or conduits must be used to protect the wire.
U.S. Pat. No. 5,285,615 to Gilmour describes a thermal metallic building stud. However, the Gilmour member is entirely formed from metal. In Gilmour, the thermal conductivity is only partially reduced by having raised dimples on the ends contacting other building materials.
U.S. Pat. No. 3,960,637 to Ostrow describes impractical wood and metal composites. Ostrow requires each end flange have tapered channels, the end flanges being formed from extruded aluminum, molded plastic and fiberglass. Ends of the vertical wood web must be fit and pressed into a tapered channel. Besides the difficulty of aligning these parts together, other inherent problems exist. Extruding the channel flanges from aluminum or using molds, cuts and rolling to create the channelled plastic and fiberglass end flanges is expensive to manufacture. To stabilize the structures, Ostrow describes additional labor and manufacturing costs of gluing members together and sandwiching mounting blocks on the outsides of each channel.
Other metal and wood framing member patents of related but less significant interest include: U.S. Pat. Nos. 5,452,556 to Taylor; 5,440,848 to Deffet; 5,072,547 to DiFazio; 4,875,316 to Johnston; 4,301,635 to Neufeld; 4,274,241 to Lindal; 4,031,686 to Sanford; and 3,531,901 to Meechan.
SUMMARY OF THE INVENTION
The first objective of the present invention is to provide a metal/wood composite wall stud that increases the total thermal resistance of a typical steel framed insulated wall section by some 43 percent and would eliminate interior condensation and "ghosting" for all but the coldest regions of the United States.
The second object of this invention is to provide a wood and metal composite framing combinations that achieve a resource efficient and economic construction framing member. Metal is used for its high strength, and potentially lower cost and resource efficiency through recycling. Wood is used primarily for its lower thermal conductivity and for its availability as a renewable resource, and for its workability.
The third object of this invention is to provide a wood and metal composite framing members that allows electricians to be able to route wires through walls in the same way they are accustomed to doing with solid framing lumber.
The fourth object of this invention is to provide a wood and metal composite framing member that would be easy to manufacture.
The fifth object of this invention is to provide a wood and metal composite framing member that has low sound conductivity compared to prior art steel framing members.
The sixth object of this invention is to provide a wood and metal composite framing member that has reduced effects from flammability compared to all wood members.
The invention includes J-shaped, L-shaped, triangular shaped cross-sectional metal forms (plate legs) connected by a wood midsections, whereby the wood is fastened to the metal by machine pressing of the metal to wood, similar to the common truss plate, or by nails, staples, screws, or other mechanical fastening means, or by adhesive glue. The outward faces of the metal members are pre-formed with four longitudinal ridges such that the contact surface area to applied sheathings is reduced by about 90%.
Metal and wood composites are used to create framing members (studs and tracks, joists and bands, headers, rafters, and the like) for light-weight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break. The metal used can be steel of approximately 18 to approximnately 22 gauge.
Metal/wood composite framing members can be used in place of conventional wood framing members such as: 2×4 and 2×6 wall studs, and 2×8, 2×10, 2×12 and other dimensions of roof rafters, floor joists and headers. The novel framing members can be used to replace conventional light-gauge steel framing to reduce thermal transmittance and sound transmission.
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1A is a perspective isometric view of a first preferred embodiment metal/wood stud.
FIG. 1B is a cross-sectional view of the embodiment of FIG. 1A along arrow AA.
FIG. 2A is a perspective isometric view of a second preferred embodiment metalwood stud.
FIG. 2B is a cross-sectional view of the embodiment of FIG. 2A along arrow BB.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal/wood stud.
FIG. 3B is a cross-sectional view of the embodiment of FIG. 3A along arrow CC.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment metal/wood joist, rafter and header.
FIG. 4B is a cross-sectional view of the embodiment of FIG. 4A along arrow DD.
FIG. 5A is a top perspective view of a fifth embodiment track for metal/wood stud systems.
FIG. 5B is a bottom perspective view of the embodiment of FIG. 5A along arrow E1.
FIG. 5C is a cross-sectional view of the embodiment of FIG. 5B along arrow EE.
FIG. 6A is a perspective view of a sixth preferred embodiment metal/wood band.
FIG. 6B is a cross-sectional view of the embodiment of FIG. 6A along arrow FF.
FIG. 7 is a cross-sectional view a framing system utilizing the embodiments of FIGS. 1A-6B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
The preferred method of calculating thermal transmittance for building assemblies with integral steel is the zone method published by the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE). A recent study by the National Association of Home Builders Research Center and Oak Ridge National Laboratory verified the usefulness of the zone method for cafculating thermal transmittance for light gauge steel walls.
Thermal transmittance calculations were completed using the zone method for the metal/wood stud invention embodiments. Table 1 shows a comparison of thermal transmittance (given as total R-value) for nine wall configurations. The first wall listed is a conventional 2×4 wood frame wall with 1/2" plywood sheathing and R-11 fiberglass cavity insulation. The total wall R-value is 13.2 hr-F-ft 2 /Btu. the second and third walls listed are conventional metal stud walls, one with 1/2" plywood sheathing (R-7.9) and the other with 1/2" extruded polystyrene sheathing (R-11.4). With conventional metal studs, high resistivity insulated sheathing is necessary to limit the large loss of total thermal resistance when low resistivity sheathings are used. In some cases, it is not desirable to use the non-structural insulated sheathing, such as when brick ties are needed, or when higher racking resistance is needed.
In comparison, the metal/wood stud walls corresponding to those described in the subject invention has a 43 per cent greater total R-value than the conventional metal stud wall when using plywood sheathing. Thernal performance of the metal/wood stud wall with plywood sheathing is nearly the same as the conventional wall with 1/2" extruded polystyrene (XPS insulated sheathing). Where non-structural sheathing is acceptable, fiber board sheathing, which is much less expensive than plywood, further increases the total R-value of the metal/wood stud wall.
TABLE 1__________________________________________________________________________COMPARISON OF THERMAL TRANSMITTANCE FOR CONVENTIONALMETAL STUD WALL AND NOVEL METAL/WOOD STUD WALL Stud Size Stud Spacing Cavity Exterior TotalDescription Inch Inch O.C. Insulation Sheathing R-Value__________________________________________________________________________1. Conventional metal stud,* 1.625 × 3.625 24 R-11 1/2" plywood 7.92. Conventional metal stud,* 1.625 × 3.625 24 R-11 1/2" XPS 11.43. Novel metal/wood stud, 1.5 × 3.5 24 R-11 1/2" plywood 11.34. Novel metal/wood stud 1.5 × 3.5 24 R-13 1/2" plywood 12.85. Novel metal/wood stud 1.5 × 3.5 24 R-15 1/2" plywood 14.26. Novel metal/wood stud 1.5 × 3.5 24 R-11 1/2" fiber board 12.17. Novel metal/wood stud 1.5 × 3.5 24 R-13 1/2" fiber board 13.68. Novel metal/wood stud 1.5 × 3.5 24 R-15 1/2" fiber board 15.0__________________________________________________________________________ *Conventional metal stud values from "Thermodesign Guide for Exterior Walls, American Iron and Steel Institute, Washington, D.C., Pub. No. RG9405, Jan. 1995. Comparison of vertical, transverse, and racking load capacities of 2 × 4 wood stud, metal stud, and subject invention wood/metal composite stud. Structural analysis by Kim McLeod, P.E. Of Keymark Enterprises, Boulder, Colorado.
Summary calculation results compared the allowable axial load for stud elements subjected to combined loading with axial and bending components. The three elements analyzed were a conventional 2×4 wood, a conventional 20 gauge steel stud, and the present invention metal/wood composite stud. All elements were 8' tall, and spaced 16" O.C. Wind (transverse) load at 110 mph. Table 2 shows that the metal/wood composite section can support 54% more weight than the metal stud, and 250% more weight than the wood stud. This gives the opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required, or for reducing the amount of steel used in the composite section.
TABLE 2______________________________________STRUCTURAL CALCULATION RESULTS FORNOVEL METAL/WOOD STUDAllowable 3.5" 20 Gauge 3.5" Metal/WoodAxial Load 2 × 4 Wood Stud Metal Stud Composite Section______________________________________8' tall stud 551 lb 894 lb 1378 lb16" O.C.110 mph wind______________________________________
FIG. 1A is a perspective isometric view of a first preferred embodiment metal/wood stud 100. FIG. 1B is a cross-sectional view of the embodiment 100 of FIG. 1A along arrow AA. Referring to FIG. 1A-1B, embodiment 100 includes metal forms 110, 120 such as but not limited to 20 gauge steel has been cold-formed in a roll press into a cross-sectional channel J-shape. Each form 110, 120 includes steel web portions 112, 122 that have staggered rows of cut-out portions 115, 125 which are of a pressed tooth type triangular shape. Web portions 112, 122 are perpendicular to flanges 116, 126 which include approximately 4 rows of raised V-shaped grooves 117, 127 running longitudinally along the exterior of the flanges 116, 126. Flange returns 118, 128 are perpendicular to flanges 116, 126. Teeth 115, 125 can be hydraulically pressed adjacent the top and bottom rear side 152 of central web board 150. Central web board 150 can be solid wood, OSB, (oriented strand board) plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, web portions 112, 122 of forms 110, 120 can be fastened to the central web board 150 by nails, screws, staples and the like, or adhesively glued. A finished metal/wood stud 100 can have a length, L1, of approximately 8 feet or longer, height H1 of approximately 3.5 to 5.5 inches, width W1 of approximately 1.5 inches. Web portions 112, 122 can have a height, h1 of approximately 1.125 inches, front plate height, h2 of approximately 0.75 inches, raised grooves R1, of approximately 0.125 inches. A spacing, x1 of approximately 0.125 inches separates each flange 116, 126 from the top and bottom of central web board 150.
FIG. 2A is a perspective view of a second preferred embodiment metal/wood stud 200. FIG. 2B is a cross-sectional view of the embodiment 200 of FIG. 2A along arrow BB. Referring to FIGS. 2A-2B, embodiment 200 includes metal forms 210, 220 such as but not limited to 20 gauge steel that has been roll pressed into a cross-sectional channel right-triangular-shape. Each form 210, 220 includes outer web portions 212, 222 that have staggered rows of cut-out portions 213, 223 which are of a pressed tooth type triangular shape. Outer web portions 212, 222 are perpendicular to flanges 214, 224 which include approximately 4 rows of raised V-shaped grooves 215, 225 running longitudinally along their exterior surface. Flange returns 216, 226 are approximately 45 degrees to flanges 214, 224, and are connected to inner web portions 218, 228 each having staggered rows of cut-out portions 219, 229 which also are of the pressed tooth type triangular shape. Teeth 213, 219 and 223, 229 can be firmly pressed adjacent the top and bottom of central web board 250. Central web board 250 can be solid wood, OSB, plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, web portions 212, 218, 222, 228 can be fastened to the central web board 250 by nails, screws, staples and the like. Outer web portions 212, 222 can have a height, B1 of approximately 1.1625 inches, flanges 214, 224 can have a width, B2 of approximately 1.5 inches, flange returns 216, 226 can have a height, B3 of approximately 0.925 inches and inner web portions 218, 228 can have a height, B4 of approximately 1 inch. A finished metal/wood stud 200 can have the remaining dimensions and spacings similar to the embodiment 100 previously described, except height, B5 can be approximately 5.5 to approximately 7.25 inches.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal/wood stud 300. FIG. 3B is a cross-sectional view of the embodiment 300 of FIG. 3A along arrow CC. Referring to FIGS. 3A-3B, embodiment 300 includes metal forms 310, 320 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 310, 320 includes metal web portions 312, 322, 318, 328 that have staggered rows of cut-out portions 313, 323, 319, 329 which are of a pressed tooth type triangular shape. Web portions 312, 322, 318, 328 attach to 45 degree flange returns 314, 324 which are attached to respective flanges 315, 325 which include approximately 4 rows of raised V-shaped grooves 316, 326 running longitudinally along their exterior surface. Teeth 313, 319 and 323, 329 can be pressed adjacent the top and bottom of central web board 350. Central web board 350 can be solid wood, OSB, plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, metal web portions 312, 318, 322, 328 can be fastened to the central web board 350 by nails, screws, staples and the like. Metal web portions 312, 318, 322, 328 can have a height, C1 of approximately 0.875 inches, flanges 315, 325 can have a width, C2 of approximately 1.5 inches, flange returns 314, 317, 324, 327 can have a height, C3 of approximately 0.4625 inches. A finished metal/wood stud 300 can have remaining dimensions and spacings similar to the embodiment 200 previously described.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment 400 useful as a metal/wood joist, rafter and header. FIG. 4B is a cross-sectional view of the embodiment 400 of FIG. 4A along arrow DD. Referring to FIGS. 4A-4B, embodiment 400 includes metal forms 410, 420 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 410, 420 includes metal web portions 412, 422, 418, 428 that have staggered rows of cut-out portions 413, 423, 419, 429 which are of a pressed tooth type triangular shape. Metal web portions 412, 422, 418, 428 attach to 45 degree flange returns 414, 424, 417, 427 which are attached to respective flanges 415, 425 which include approximately 4 rows of raised V-shaped grooves 416, 426 running longitudinally along their exterior surface. Teeth 413, 419 and 423, 429 can be pressed adjacent the top and bottom portions of central web boards 452, 454. A central metal plate 460 has left facing tooth rows 463 and right facing tooth rows 465 for connecting to adjacent respective web boards 452, 454. Plate 460 has a spacing above and below to separate such from flanges 415, 425. Central web boards 452, 454 can be solid wood, OSB, plywood and the like, having a thickness of approximately 0.375 inches. Alternatively, metal web portions 412, 418, 422, 428 can be fastened to the central web boards 452, 454 by nails, screws, staples and the like. Metal web portions 412, 418, 422, 428 can have a height, D1 of approximately 1.0188 inches, flanges 415, 425 can have a width, D2 of approximately 1.5 inches, flange returns 414, 417, 424, 427 can have a height, D3 of approximately 0.3188 inches. A finished embodiment 400 can have practically any length, L2 to serve as a floor joist, rafter or header, width D2 can be approximately 1.5 inches and height D4, can be approximately 5.5 inches or more.
FIG. 5A is a top perspective view of a fifth embodiment track 500 for metal/wood stud and track systems. FIG. 5B is a bottom perspective view of the embodiment 500 of FIG. 5A along arrow E1. FIG. 5C is a cross-sectional view of the embodiment 500 of FIG. 5B along arrow EE. Referring to FIGS. 5A-5C, embodiment 500 includes metal forms 510, 520 each having a generally L-shaped cross-section. Forms 510, 520 each include flanges 512, 522 approximately 1.125 inches in height perpendicular to metal web portions 514, 524, which are approximately 1.1625 inches in length. Metal web portions 514, 524 have tooth shaped triangular cut-outs 515, 525, which are pressed into sides of center-web-board 550. A spacing E2 of approximately 0.125 inches separates the ends of center-web-board 550 from flanges 512, 522, respectively. A finished embodiment 500 can have remaining dimensions and spacings similar to the embodiments 100, 200, and 300 above.
FIG. 6A is a perspective view of a sixth preferred embodiment metal/wood joists and bands 600. FIG. 6B is a cross-sectional view of the embodiment 600 of FIG. 6A along arrow FF. Referring to FIGS. 6A-6B, embodiment 600 includes top metal form 610 having a T-cross-sectional shape and lower metal form 620 having a straight line cross-sectional shape. Form 610 includes metal web portion 612, having a length, F1 of approximately 1.0375 inches having tooth shaped triangular cut-outs 613 which are pressed into upper end sides of wood center web board 650. Form 610 further includes an upright leg 614 having a length F2 of approximately 1.3 inches, perpendicular to a third leg 616, having a length, F3 of approximately 1.25 inches, which abuts against and overlaps top end 652 of centerboard 650. Lower metal form 620 has a metal web portion 622 having tooth shaped triangular cut-outs 623 which are pressed into upper end sides of wood center board 650, and a continuous extended plate 624. The continuous width F4, of metal plate 622, 624 is approximately 1.75 inches, with plate 624 extending a length F5 of approximately 0.75 inches from the lower end 654 of center-web-board 650 having thickness of approximately 0.5 inches. A finished embodiment 600 can have a width F6 and length L3 similar to embodiment 400.
FIG. 7 is a cross-sectional view a framing system 700 utilizing the embodiments of FIGS. 1A-6B. Embodiment 700 can be a two story building having a metal/wood bottom track 500 attached at floor 702 by conventional fasteners such as nails, screws, bolts and the like. Vertically oriented metal/wood studs 100/200/300 can be attached to floor and ceiling tracks 500 by steel framing screws 715 and the like. A metal/wood band 600 attaches first floor ceiling track 500 to metal/wood floor joist 400 and subfloor 710, which has conventional steel framing flathead type screws 716 and the like. The second floor has a similar arrangement with rafters 400 attached at conventional angles to upper metal/wood top track 500.
A cost of a metal/wood composite stud such as those described in the previous embodiment 100 is estimated to be $4.24. The lowest cost of conventional 20 gauge steel studs is $2.52 each, however, to obtain the same thermal performance, an insulated sheathing is required which raises the cost to $4.55 per stud. The metal/wood framing member's invention is directly cost effective compared to the conventional metal stud. In addition, structural calculations show that the metal/wood stud configuration can support 54% more weight at the same 8' wall height, 16" O.C. spacing, and 110 mph wind load. This give opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required. For example, a 2000 square foot house framed 16" O.C. will have about 168 conventional steel exterior wall studs, the same house framed 24" O.C. with the stronger metal/wood composite exterior wall studs will use only 107 studs. With 61 fewer exterior wall studs required, the builder can save about $270.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. For the claims, the invention will be described as having all metal portions including the forms to be referred to as flanges, and all mid wood portions will be referred to as wood web members.
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Metal and wood composites are used to create framing members (studs and tracks, joists and bands, rafters, headers and the like.) for lightweight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Metal that can be used includes roil formed steel approximately 18-22 gauge. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break. The invention connects J-shaped or triangular shaped metal forms to wood sections. The metal flange ends can have various J, C, L, right triangular, triangular, T and straight line cross-sectional shapes. The wood is fastened to the metal by machine pressing of the metal to wood. Alternatively the fastening includes nails, staples, screws, and the like, and also by adhesive glue. The outward faces of the metal members are pre-formed with four longitudinal ridges such that the contact surface area to applied sheathings is reduced by about 90%.
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BACKGROUND
The present invention relates to a method and apparatus for injection molding, and in particular, to a method and apparatus for molding injection molded parts.
Conventionally, a variety of methods have been utilized for injection molding in various fields. Of these methods, a molding metal mold of a runnerless (hot runner) system has been widely used.
There are a variety of molds in such a hot runner system. Smaller molds generally only require one inlet for injecting molten material. For larger molds, several inlets are used to inject molten material at different points within the mold cavity. These larger molds are sometimes referred to as multi-gate mold cavities. In multi-gate mold cavities, the pressure of molten material differs at various points inside the cavity. The pressure typically becomes constant throughout the cavity once the cavity is completely filled with molten material.
A conventional molding process can be done using power from hydraulic means or electrical means. The molding process uses two platens, a movable platen and a stationary platen. In a process using hydraulic means, a hydraulic cylinder applies a certain force to push a movable platen against a stationary platen. Molding members within or attached to the platens form a molding cavity. The force is maintained on the stationary platen or die plate while a molten material is injected into the molding cavity. The molten material is injected into the cavity with a resin feeding screw until the pressure inside the cavity reaches a predetermined molding pressure or until the screw has moved a predetermined distance and for a set period of time, thereby ensuring that the cavity is filled. After injecting the molten material, the molten material is allowed to cool and solidify, the force is then released, and the plates are separated and the process begins anew.
Some injection molding machines use a mold with only one cavity, thereby allowing for the production of one molded object per cycle. Total cycle time is the sum of the fill time and the cool down time. The cool down time is generally substantially longer than the fill time. For example, a typical fill time is about 5 seconds, whereas a typical cooling time is about 30 seconds, for a total of about 35 seconds for the production of one molded article.
To reduce process time per molded article, some injection molding machines utilize molds with a plurality of cavities for forming a plurality of molded articles. The molten material fills into each of the cavities simultaneously. While this may extend the fill time a few seconds, for example for mold cavities for car doors, to about 8 seconds, the cooling time remains fixed at about 40 seconds. The total time of this process is about 48 seconds for the production of two molded articles. Thus, using multiple cavities increases the efficiency almost two-fold.
A problem with the multiple cavity method, however, is that the mold clamping force must also be doubled since the article molding area is doubled. As a result, a larger injection molding machine must be used to apply the extra force needed to hold the molding platens together. A larger injection molding machine costs more, takes up more floor space, and requires more power. Therefore, using multiple cavity molds with the conventional method can sacrifice cost for greater time efficiency.
Furthermore, for molding larger articles, the molten material is injected at several different points in the mold cavity. This is due to the limits on the flow of molten plastic. These larger mold cavities are commonly known as multi-gate mold cavities. An example of an article that would require a multi-gate mold cavity is an interior car door panel, which typically requires four or five gates per single cavity mold. In the manufacture of such parts, it is desirable to maintain the injected pressure of the molten material constant so that the part is formed accurately. Without maintaining the pressure constant, the structural accuracy of the formed part may suffer. For example, the resulting part may include short shots, ripples, or other dimensional inaccuracies. As such, there is a need to be able to accurately measure the pressure of molten plastic inside of the mold cavity.
Accordingly, a general object of the present invention is to provide an injection molding machine and a method for injection molding either large or small articles where there is process control for each cavity.
A further object of the present invention is to provide an injection molding machine and a method for injection molding large articles with greater efficiency and reduced costs.
BRIEF SUMMARY
In one aspect, the invention is a method for sequentially injecting a molten material comprising clamping a stationary platen and a movable platen at a clamping force to define at least two cavities, opening a first valve gate to inject a molten material into a first cavity, closing the first valve gate either by position, time or pressure switch, opening a second valve gate to inject the molten material into a second cavity, and closing the second valve gate when the desired position, time or pressure switch value has been met.
In a second aspect, the invention is an injection molding apparatus comprising a mold having at least two mold cavities, a molten material inlet system in communication with said at least two mold cavities, at least two valve gates in said molten material inlet, wherein each of said at least two valve gates are associated with one of said mold cavities; and a controller adapted to sequentially open and close said valve gates.
In a third aspect, the invention is a controller for use with a injection molding device having a mold with at least two cavities, the controller comprises means for opening a first valve gate associated with a first mold cavity to initiate a flow of molten material into the first mold cavity, means for closing the first valve gate by either position, time or pressure switch, means for opening a second valve gate associated with a second cavity to initiate a flow of molten material into a second mold cavity, and means for closing the second valve gate by either position, time or pressure switch.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the invention, are given by way of illustration only, the invention being defined only by the claims following this detailed description.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein:
FIG. 1 is a schematic view of an injection molding apparatus suitable for the method of injection molding a molten material, provided by the present invention.
FIG. 2 is a schematic view of a part of the injection molding apparatus showing a state immediately after clamping the mold, and a state in which the introduction of the molten material is initiated, in the method of injection molding, provided by the present invention.
FIG. 3 is a perspective view of a part of the injection molding apparatus showing a multi-gate injection molding system with multiple multi-gate molds, in the method of injection molding, provided by the present invention.
FIG. 4 is a flowchart illustration of the sequential injection molding process of the present invention.
FIG. 5 schematically shows a change in injection velocity with time for a conventional injection molding method and a sequential injection molding method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, the injection molding apparatus suitable for use in the method of injection-molding a thermoplastic or thermoset resin, provided by the present invention, will be outlined below with reference to FIG. 1 . Although the injection molding apparatus described and shown in FIG. 1 uses hydraulic power, one of ordinary skill in the art would recognize that an electrically powered molding apparatus can also be used for the present invention. The injection molding apparatus includes an injection cylinder 12 having a resin-feeding screw or extrusion screw 10 inside, a stationary platen 40 , a movable platen 44 , an inlet 26 , tie bars 34 , a clamping hydraulic cylinder 30 and a hydraulic piston 32 . The movable platen 44 is actuated with the hydraulic piston 32 in the hydraulic cylinder 30 to move in parallel on the tie bars 34 .
A mold is formed by a stationary mold member 36 and a movable mold member 46 . The stationary mold member 36 is attached to the stationary platen 40 , and the movable mold member 46 is attached to the movable platen 44 . The platens 40 , 44 , the tie bars 34 , and the cylinder 30 and piston 32 define a clamping system for applying a clamping pressure to the mold members 36 , 46 . The movable platen 44 is moved towards the stationary platen 40 until the movable mold member 46 is engaged with the stationary mold member 36 , and the mold is clamped to form multi-gate cavities 22 , 24 . This clamped position is illustrated in FIG. 2 .
After the mold has been clamped, the clamping force is controlled with the clamping hydraulic cylinder 30 . The clamping force may also be controlled by toggle or an electric machine. The molten material flows into the cavities 22 , 24 via inlets 26 . Valve gates 50 , 52 may be used, but are not necessary, to open and close inlets 26 . If used, valve gates 50 , 52 would face cavities 22 , 24 and at least one valve gate is associated with each cavity 22 , 24 respectively. After the molten material cools and hardens, the clamping force is released and the movable platen 44 is moved away from the stationary platen 40 , in order to release the molded product.
For the exemplary two-cavity multi-gate mold shown in FIG. 2 , the sequential injection molding method begins with clamping the mold with at a mold clamping force. The controller 60 then closes valve gate 52 and opens valve gate 50 . Molten material fills cavity 22 . The amount of material that enters the cavity may be controlled by the use of pressure transducers P 1 , P 2 or preferably can be controlled by predetermining the distance or time the resin feeding screw 10 must travel to fill cavity 22 . Conventional molding processes use the position of the resin feeding screw 10 to control the amount of material being injected into the mold cavity and to ensure that the cavity is full and packed. Sometimes, the time the screw travels is the controlling variable in filling the cavity.
As molten material enters through the inlet, it gradually fills the entire cavity. A stroke sensor or potentiometer 65 measures the distance resin feeding screw 10 has moved and transmits this reading to the controller 60 . The controller 60 uses the data from the stroke sensor and/or a timer to determine when to close valve gate 50 to stop the flow of molten material into cavity 22 and open valve gate 52 to start the flow of molten material into cavity 24 . The controller closes valve gate 50 when the resin feeding screw has traveled a pre-determined distance or for a predetermined period of time. If no hold pressure is used in molding the article, the valve gate 50 is closed at the switchover point which is the point when the entire cavity gets filled with molten material and begins to exert a pressure on the cavity. If a hold pressure is used, the valve gate is kept open for a fixed period of time after the molten material has filled the entire cavity and the resin feeding screw exerts a holding pressure. After the fixed period of time the valve gate 50 is closed. If pressure transducers are used, the controller closes valve gate 50 and opens valve gate 52 when the pressure inside the cavity reaches a set point pressure. The controller opens valve gate 52 and the resin feeding screw may then retreat back or may continue from its end position depending on whether or not there is enough material in the injection chamber to fill the second cavity 24 . In a preferred embodiment, the pressure exerted by the resin feeding screw is decreased between the closing of valve gate 50 and the opening of valve gate 52 . In the alternative, the screw is activated after delay time of about 0.5 seconds after opening valve gate 52 . This prevents a sudden high pressure shot upon the opening of valve gate 52 and provides greater control of the process. Molten material then fills into cavity 24 . When the resin feeding screw 10 has moved the predetermined distance or time to fill and pack cavity 24 , the molten material is held inside cavities 22 , 24 and is allowed to cool and solidify. At this point, valve gate 52 may be left open if there are no additional mold cavities to be utilized, otherwise the controller closes valve gate 52 and the process repeats.
FIG. 3 shows a perspective view an embodiment of the multiple multi-gate mold injection system of the present invention. In particular, there are two multi-gate mold cavities for interior car door panels 71 . Molten material enters into the main inlet 75 and then flows into the multi-drop hot manifold 76 that has inlets at various points in the mold cavity. Pressure transducers 73 may be placed inside the cavity, preferably at the end of fill point 72 , to measure the pressure inside the cavity. Ejector pins 74 release the molded article once the molten material cools and solidifies.
FIG. 4 is a flowchart illustration of the sequential injection molding process of the present invention. It will be understood that each step of the flowchart illustration can be implemented by computer program instructions or can be done manually. These computer program instructions may be loaded onto a computer or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart step. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart step. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart step.
It will be understood that each step of the flowchart illustration can be implemented by special purpose hardware-based computer systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions, or can be done manually.
An injection molding machine utilizing a sequential injection molding process has a plurality of multi-gate mold cavities formed by the movable mold member 46 and the stationary mold member 36 . For an injection molding machine with m cavities, where n equals 1 to m, the process begins with step 100 by closing the clamp with a mold clamping force calculated by the equation:
mold clamping force required=(clamp tonnage required per square inch)×(surface area of cavity n )
The clamp tonnage is predetermined and is calculated based upon the type of molding material and the desired characteristics of the molded article. For example, an ABS material may require two to three tons of pressure per square inch of area. Other materials require different amounts of pressure. In step 110 , a first valve gate is opened which faces a first cavity. The first cavity is then injected with molten material using a resin-feeding screw at a predetermined injection velocity in step 120 . The injection velocity may be changed or may be kept constant as the cavity becomes filled with molten material. The time it takes to fill the cavity to the V/P change over position or the set-point pressure depends on the size of the cavity and the injection velocity. In a preferred embodiment, the injection velocity is varied and it takes about one second to about ten seconds to fill the cavity to the set-point pressure or V/P change over position. In step 130 , the controller monitors the distance, time and/or velocity at which the resin screw has moved and compares it to the set-point values said screw must move in order for molten material to fill the cavity or reach the velocity to pressure (V/P) switch point. The V/P switch point occurs when the molten material has fully filled the cavity and begins to exert a pressure inside the cavity. In one embodiment, if a predetermined holding pressure at which the material must be held is used, resin feeding screw exerts a holding pressure for a predetermined time before the controller closes the valve gate to the cavity. The process goes back to step 120 if the cavity is not full or has not reached the V/P switch point if there is no holding pressure, or has not reached a predetermined holding pressure if using holding pressure or has not reached the pressure switch set value. The first valve gate is closed once the cavity is full if not using holding pressure or once it is full and has been held for a predetermined period of time at a holding pressure or has reached the pressure switch set value in step 140 . The process goes back to step 110 and repeats for n cavities. After all of the cavities are full, the machine recovers for the next shot in step 150 the molten material inside the cavities is allowed to cool and solidify in step 160 . The cooling process takes about 20 seconds to about 40 seconds, depending upon the size of the molded article and the type and temperature of the molded material. After cooling, the mold clamping force is released and the clamp is opened in step 170 . The sequential injection molding process ends with step 180 , when the molded articles are ejected from the molding cavities.
The mold clamping force required is reduced significantly in a sequential injection molding process for a multiple cavity mold. This is because the area to be pressurized does not increase when there are multiple cavities. For a mold with multiple cavities, the area to be pressurized remains constant and equals the area of one cavity since each cavity in the mold is pressurized and closed sequentially. Therefore, the mold clamping force required in a two-cavity mold is reduced to almost half by using the sequential injection molding method compared to a conventional method. The mold clamping force required in a three-cavity mold the force required is reduced by over fifty percent compared to the force required in the conventional method. This significant reduction in mold clamping force allows for a reduction in the press size, which in turn allows for dramatic cost savings in terms of production cost per molded article.
FIG. 5 shows how the injection velocity varies during the step of filling a cavity for a standard injection molding process compared to a sequential injection molding process in a two-cavity mold. The injection velocity is controlled by the machine set-point of the resin-feeding screw 10 . In a standard injection molding process the cavities are filled with molten material simultaneously and in the sequential method the cavities are filled sequentially. Both processes may be carried out with more than two cavities. The sequential molding process, however, has at least two cavities.
In a standard injection molding process, the injection pressure is set above the necessary pressure requirement to fill the mold cavity. The injection velocity of the molten material is set at a filling flow rate prior to the valve gate being opened. As illustrated in FIG. 5 , the injection velocity is kept at filling flow rate until the cavities are almost full. The injection velocity is then gradually tapered down from the filling flow rate so that the injection velocity of the molten material can be controlled to allow proper fill of the entire cavity. Once the pressure inside the cavity reaches the set-point molding pressure, the injection velocity is brought down to zero or if molding by position when the cavity reaches the desired fill level. Decreasing the injection velocity ensures that the molten material is uniform inside the cavities, thereby yielding a higher quality molded article.
In the sequential injection molding process, the injection pressure is set above the necessary pressure requirement to fill the mold cavity. This pressure requirement is dependent on the physical properties of the molten material such as its viscosity. The injection velocity of the molten material is set at a filling flow rate when a valve gate is opened. The injection velocity is kept at the filling flow rate until a cavity is almost full and then gradually tapered down until the cavity is full at the switchover point or if holding pressure is utilized until the hold timer times out. The difference in the sequential method compared to the standard method, is that the injection velocity is increased again to the filling flow rate when the second valve gate is opened. This adds approximately 0.5 seconds to about 4 seconds to the total fill-time for the process. In a preferred embodiment, the ramp up of the injection velocity to the filling flow rate is rapid so that the total process time does not increase significantly.
It is contemplated that numerous modifications may be made to the injection molding method and apparatus of the present invention without departing from the spirit and scope of the invention as defined in the claims. For example, while the exemplary embodiment shown in the drawings has two multi-gate mold cavities, those skilled in the art will appreciate that the same sequential steps can be used to control the flow of molten material into molds having more than two cavities. In addition, for molds having more than two cavities, there may be a valve gate associated with each cavity, with each valve gate opened and closed sequentially. Alternately, for molds having more than two cavities, there may be fewer valve gates than cavities, as long as there are at least two cavities. In this embodiment, at least one of the valve gates would control the inlet to at least two cavities. Accordingly, while the present invention has been described herein in relation to several embodiments, the foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, arrangements, variations, or modifications and equivalent arrangements. Rather, the present invention is limited only by the claims appended hereto and the equivalents thereof.
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A multi-cavity injection molding method and device, and a controller for sequentially injecting material into cavities in the injection molding device. The methods and devices are effective to reduce the clamping force needed to clamp multiple cavity molds.
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SUMMARY OF THE INVENTION
The present invention is concerned with a process for decarburizing ferro-manganese having a high content of carbon, so-called "carburized" ferro-manganese, in order to obtain ferro-manganese having a lower content of carbon, so-called "refined ferro-manganese".
It is well known to refine baths of pig iron and steel in converters provided with tuyeres which are protected from attack by a surrounding stream of protection fluid. Such metallurgical operations are rapid and thus give good productivity and a very competitive cost. Such processes have not previously been applied to the refining of ferro-manganese. In oxidative refining, the treatment of ferro-manganese presents two specific difficulties:
(a) the loss of a sizeable part of the manganese into the slag, as a result of preferential oxidation of the manganese with respect to oxidation of the carbon, and
(b) the loss of a substantial part of the manganese by volatilization during blowing as manganese is a relatively volatile element.
It has been found that in order to favor decarburization rather than oxidation, of the manganese, it is necessary to heat the bath to the maximum possible temperature, whilst to reduce the volatilization of the manganese, it is necessary to heat the bath to the lowest possible temperature.
We have now developed a process for the oxidative decarburization of ferro-manganese which represses the two disadvantages mentioned above sufficiently for the process to become competitive.
According to the present invention, we provide a process for decarburizing a ferro-manganese melt from a carbon content of as high as 7.5% down to 2% or less by blowing an oxidizing gas into the melt in two stages through one or more immersed tuyeres protected with a peripheral fluid introduced into said tuyeres, utilizing temperatures between 1650° and 1750° C.
DETAILED DESCRIPTION
The process of the invention comprises the successive steps of:
(a) blowing pure oxygen to reduce the carbon content from an initial value, C 1 , of from 6 to 7.5% to a second value, C 2 , of from 2% to 3.5% and to raise the melt to a temperature of from 1650° to 1750° C., and
(b) blowing an oxidizing gas consisting of 0 to 50% of oxygen, at least 30% of steam, and 0 to 70% of an inert gas, all by volume, said gases being blown as a mixture or separately, to reduce the carbon content from the second value, C 2 , to a third value, C 3 , which is at most 1.6% and to maintain the temperature of the melt at from 1650° to 1720° C.
In step (a), the melt is preferably raised to a temperature of from 1670° to 1710° C.
Where a final carbon content of less than 1.2% is required, an advantageous option is as follows: the melt is blown with an oxidizing gas consisting of 0 to 25% of oxygen from 30 to 50% of steam, and from 30 to 70% of an inert gas, all by volume, said gases being blown as a mixture or separately, to reduce further the carbon content from the value C 3 and to maintain the temperature of the melt at from 1660° to 1720° C.
It is conventional in oxidative blowing decarburization processes to protect the tuyere (s) from attack by providing a surrounding stream of protective fluid (liquid or gas). If this procedure is used, the protective fluid used in steps (a) and (b) may or may not be such as to introduce carbon into the melt, but the protective fluid used in the option hereabove described for low carbon contents must not be such as to introduce carbon into the melt.
When steps (a) and (b) are completed, the melt may, if desired, be subjected to dehydrogenation by blowing with an inert gas, such as argon or nitrogen.
On completion of decarburization, it is desirable to recover some of the manganese which is present in the slag as manganese oxide. One way of doing this is to add one or more reducing components, such as ferro-silicon or silico-manganese, to the slag and then to blow the melt with an inert gas such as argon or nitrogen so as to liquefy the slag and reduce manganese oxides present therein to manganese.
Another way of recovering manganese is to add silica, alumina or calcium fluoride to the slag in order to liquefy it, decant off the liquefied slag and pass it to a reduction furnace wherein the manganese oxides present in the slag are reduced to manganese and the latter recovered.
When it is desired to obtain a nitrided refined ferro-manganese, the inert gas used in step (b) and/or in the dehydrogenation step mentioned above, should be nitrogen, the amount of nitrogen used being such as to give the desired nitrogen content in the final ferro-manganese.
If desired, controlled additions of manganese minerals, such as pyrolusite, or pellets made with manganese oxide-containing dust collected by dedusting converter fumes, may be introduced through the mouth of the refining converter during step (a). In this way relatively cheap manganese oxide can be introduced into the slag and can be at least partially reduced during the first step by virtue of the reduction potential of the melt which is relatively rich in carbon at that moment.
Following completion of decarburization, the final slag may, if desired, not be removed and a fresh charge of ferro-manganese to be decarburized is introduced into the converter, reduction of the manganese oxide present in the slag from the previous charge being effected in carrying out step (a) on the fresh charge.
As will be understood, the advantages of the invention arise from being able to use simultaneously, and in the metallurgically optimum proportions at any instant:
oxygen as an oxidizing and heating gas,
steam as an oxidizing and cooling gas which also, as a result of the hydrogen resulting from its decomposition, has a diluting effect on the carbon monoxide hence favoring the decarburization of the melt relative to the oxidation of the manganese,
an inert gas, for example nitrogen or argon, to dilute the carbon monoxide, but without cooling the melt as much as the steam does, and
a surrounding protective fluid which protects the blowing nozzle (s) against wear.
Accordingly, in the process according to the invention the following different effects are, in effect, quite distinct: oxidation--heating--cooling--dilution of the carbon monoxide--protection of the nozzles. And it is possible to vary one of them without disturbing the others. Thus, for example, at a bath temperature of less than 1,700° C., an increase in the amount of steam enables a possible rise in temperature, with concommitant volatilization of the manganese, to be reduced or prevented. Steam therefore plays a fundamental role in step (b) as a thermal regulator and hence as a moderator of the volatilization of the manganese.
Conversely, if, during step (b), the temperature of the melt is too low and it is therefore necessary to reduce the supply of steam, it is nevertheless possible to maintain the dilution of the carbon monoxide so as to avoid excessive scorification of the manganese, by increasing the supply of inert gas in accordance with the reduction in the supply of steam.
In order that the invention should be more fully understood, the following example, in which all percentages are by weight unless otherwise specified, is given by way of illustration only:
EXAMPLE
A converter having a capacity of 6 tons, the bottom of which was provided with 2 vertical tuyeres each consisting of 3 concentric tubes, was charged with 5,340 kg of ferro-manganese containing 78.3% manganese, 6.51% carbon, 0.17% silicon and 14.7% iron, and 100 kg of calcined dolomite, the ferro-manganese being liquid and at a temperature of 1,305° C.
In a first step, (a), pure oxygen was blown through the two inner tubes of each of the two tuyeres, at a rate of 20 Nm 3 /minute for the two tuyeres until a total of 281 Nm 3 had been blown. The two tuyeres were protected against wear by a stream of fuel-oil introduced through each external tube.
at the end of step (a), the melt had the following analysis:
C=2.01%, Mn=81.65%, Si=less than 0.1%, Fe=14.2%, and its temperature was 1,700° C.
The slag had the following analysis:
SiO 2 =0.57%, CaO=8.35%, Al 2 O 3 =0.15%, MgO=5.7%, total iron=9.35%, total Mn=68.3% (including metal balls dispersed in the slag).
In a second step, (b), pure oxygen was blown through the middle tube of each tuyere at a rate of 6 Nm 3 /minute for the two tuyeres and steam was blown through the central tube at the rate of 6 Kg/minute, representing 7.5 Nm 3 /minute for the two tuyeres, until a total of 35 Nm 3 of oxygen and 35 kg (or 43.5 Nm 3 ) of steam had been blown.
At the end of step (b) the melt had the following analysis:
C=1.37%, Mn=80.85%, Fe=16.7%, and its temperature was 1,680° C.
The slag had the following analysis:
SiO 2 =1.32%, CaO=7.6%, Al 2 O 3 =0.21%, MgO=10.5%, total iron=9.45%, total Mn=64.4% (including metal balls dispersed in the slag).
To the melt were then added 130 kg of 75% ferro-silicon and 130 kg of lime, while blowing 6 Nm 3 of argon per minute through the melt until a total of 30 Nm 3 of argon had been blown therethrough.
4,770 kg of ferro-manganese were obtained, of the following analysis:
C=1.33%, Mn=81.05%, Si=0.77%, Fe=16.6%, whilst the analysis of the slag was
SiO 2 =24.4%, CaO=29.0%, Al 2 O 3 =0.77%, MgO=9.5%, total iron=1.8%, total Mn=29.85%.
Metal which had been deposited around the mouth of the converter, known as "mouth skull", was recovered in an amount of about 100 kg.
Overall, the yield of refined ferro-manganese was 88.2% and the yield of manganese amounted to 91.47%.
Of course, these yields could be improved slightly if converters of larger capacity were to be used.
The consumption of fuel-oil to protect the two tuyeres amounted to 29 liters, representing 6.1 liters per ton of ferro-manganese refined. Here again, the consumption of fuel-oil per ton produced would drop significantly with converters of larger capacity.
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Ferro-manganese is decarburized from a carbon content of as high as 7.5% down to 2% or less by blowing an oxidizing gas into the melt in two stages through one or more immersed tuyeres protected with a peripheral fluid introduced into said tuyeres, utilizing temperatures between 1650° and 1750° C.
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BACKGROUND
[0001] This disclosure relates generally to the field of integrated circuit manufacturing, and more particularly to verification patterns for optical proximity correction (OPC) numerical models.
[0002] The formation of various integrated circuit (IC) structures on a wafer often relies on lithographic processes, sometimes referred to as photolithography or lithography. Lithographic processes can be used to transfer a pattern of a photomask (or mask) to a semiconductor wafer.
[0003] A pattern may be formed using a photoresist layer disposed on a wafer by passing light energy through a photomask (or mask) of the pattern to image the desired pattern onto the photoresist layer. The pattern is thereby transferred to the photoresist layer. In areas where the photoresist is sufficiently exposed to the light, and after a development process, the photoresist material becomes soluble such that it may be removed to selectively expose an underlying layer (e.g., a semiconductor layer, hard mask layer, etc.). Portions of the photoresist layer not exposed to a threshold amount of light energy will not be removed and serve to protect the underlying layer during further processing of the wafer (e.g., etching exposed portions of the underlying layer, implanting ions into the wafer, etc.). After processing is completed, the remaining portions of the photoresist layer may be removed.
[0004] There is a trend in IC fabrication to increase the density with which various structures are arranged on a wafer; feature size, line width, and the separation between features and lines are becoming increasingly smaller. For example, nodes with a critical dimension (CD) of about 65 nanometers (nm) to about 45 nm have been proposed. In these sub-micron processes, yield of the wafer manufacturing process is affected by factors such as mask pattern fidelity, optical proximity effects, and photoresist processing. Some of the more prevalent concerns include line end pullback or bridging, corner rounding, and line width variations. Contact holes may also have a tendency to bridge and/or shift from a desired location. These concerns are largely dependent on local pattern density and topology.
[0005] OPC modeling is a technique used to improve lithographic image fidelity in semiconductor fabrication. OPC involves executing an OPC software program on a computer. The OPC program carries out a computer simulation that takes an initial data set having information relating to a desired pattern on a semiconductor product, and manipulates the data set to arrive at a corrected data set in an attempt to compensate for the above-mentioned concerns. The photomask can then be made in accordance with the corrected data set. The OPC process can be governed by a set of optical rules, employing fixed rules for geometric manipulation of the data set, modeling principles, employing predetermined behavior data to drive geometric manipulation of the data set, or a hybrid set of optical and fixed rules.
[0006] Prior to correcting a data set using OPC, it may be desirable to verify the performance (or accuracy) of the OPC model upon which the OPC routine relies and to select one of a plurality of OPC models to be used during the OPC routine. Verifying an OPC model may involve hand checking layout corrections made to a test pattern that is exposed and printed on a test wafer to verify that the OPC model performs in an expected manner. Such techniques for validating OPC models involve intensively manual processes that are time consuming and prone to error.
BRIEF SUMMARY
[0007] In one aspect, a method for optical proximity correction (OPC) model accuracy verification for a semiconductor product includes generating a multifeature test pattern, the multifeature test pattern comprising a plurality of features selected from the semiconductor product; exposing and printing the multifeature test pattern on a test wafer under a process condition; generating an OPC model of the semiconductor product for the process condition; and comparing the test wafer to the OPC model to verify the accuracy of the OPC model.
[0008] In another aspect, a test mask comprises a multifeature test pattern for optical proximity correction (OPC) model accuracy verification for a semiconductor product, the multifeature test pattern comprising a plurality of features selected from the semiconductor product, wherein the test mask is configured to be exposed and printed under a process condition on a test wafer that is compared to an OPC model of the semiconductor product generated for the process condition to verify the accuracy of the OPC model.
[0009] Additional features are realized through the techniques of the present exemplary embodiment. Other embodiments are described in detail herein and are considered a part of what is claimed. For a better understanding of the features of the exemplary embodiment, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
[0011] FIG. 1 is a top view of an embodiment of a multifeature test pattern for OPC model verification.
[0012] FIG. 2 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a focus of negative 80 nanometers (nm).
[0013] FIG. 3 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a focus of negative 40 nm.
[0014] FIG. 4 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a negative 10% dose.
[0015] FIG. 5 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a best focus.
[0016] FIG. 6 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a positive 10% dose.
[0017] FIG. 7 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a focus of positive 40 nm.
[0018] FIG. 8 is a top view of the printed multifeature test pattern for OPC model verification of FIG. 1 at a focus of positive 80 nm.
[0019] FIG. 9 illustrates a flowchart of an embodiment of a method for OPC verification using a multifeature test pattern.
DETAILED DESCRIPTION
[0020] Embodiments of a multifeature test pattern for OPC are provided, with exemplary embodiments being discussed below in detail. A test pattern is designed to include a selection of multiple features that are present in a final semiconductor wafer product. By designing a single test pattern that combines a plurality of features that exist in the semiconductor product, and in the OPC model of the semiconductor product, to be measured as well as produce failure aspects, the OPC verification data collection process may be simplified, allowing collection of OPC verification data for a relatively large number of wafer features under a wide variety of process conditions. The features that may be included in the multifeature test pattern may include, but are not limited to: pitch, line-end, dense line-end, H bar, broken H bar, nested U, mirror U, landing-pad, two-T, snake, mushroom, rotated-L, and contacts. The time required to validate the OPC model may be reduced, and the amount of data available for different process conditions increased. Inclusion of multiple features in a single test pattern may also ensure that the modeler is able find data for all of the semiconductor product features that need to be validated. Failure modes, including pinching, bridging, necking, and ringing, may also be evaluated under a variety of process conditions.
[0021] The OPC model is a numerical tool that simulates aspects of the exposure process. OPC model verification to check the performance and accuracy of the OPC model is an essential step in the OPC process. The multifeature test pattern may be designed to contain features that are arranged so as to include some or all of the representative features in the semiconductor product being modeled. The multifeature test pattern is exposed and printed on a wafer to collect verification data, and compared to an OPC model representing the production process, or the mask exposure process, generated using OPC computer simulation. The OPC model is also constructed using test structures that are representative of the semiconductor product. Exposure, printing, and modeling may be repeated for a wide variety of process conditions. Data from a printed test wafer, including both CD measurements and printing contours of individual features on the test wafer and images of the test wafer, are then used to verify the accuracy of the prediction of the OPC model. The verification process may check aspects of the OPC model such as the ability of the OPC model to accurately predict the CDs of the printed features, and to predict failure aspects, such as bridging, pinching, necking, and ringing, under different process conditions.
[0022] The measurements and images of the printed test pattern on the test wafer may be taken by a scanning electron microscope (SEM). The multifeature test pattern may be designed such that the size of the printed multifeature test pattern is about the same as the maximum field of image of the SEM. The resolution of the multifeature test pattern may also be designed to be about the same as the maximum resolution of the SEM. Therefore, the size and resolution of a multifeature test pattern may depend on the particular SEM tool being used to take the validation measurements of the test wafer. In some embodiments of OPC verification, only images of the test wafer test structures are overlaid and compared to the OPC model prediction, without performing comparison of individual feature CD measurements. In such an embodiment, selection of the size and resolution of the multifeature test pattern based on the SEM requires only one image of the test wafer to be taken by the SEM per process condition, as the image may contain the entire test pattern at a relatively high resolution. This allows OPC verification to be performed over a wide variety of process conditions relatively quickly. In embodiments in which measurements of the individual features on the printed wafer are also performed, the metrology time as well as the time for the OPC verification process may also be significantly reduced by the presence of a relatively large number of features on the single multifeature test pattern, requiring only one test wafer to be exposed and printed per process condition.
[0023] FIG. 1 illustrates an embodiment of a multifeature test pattern 100 . The multifeature test pattern includes a plurality of IC test features and possible failure modes, including but not limited to possible bridging at 101 , broken H bar 102 , pitch and line end 103 , possible pinching at 104 , and possible ringing at 105 . Multifeature test pattern 100 is shown for illustrative purposes only; a multifeature test pattern may include any number and type of features, arranged in any appropriate way, based on the test pattern features representing the features present in the final semiconductor product being evaluated by the OPC model. The features on a multifeature test pattern, such as multifeature test pattern 100 , may include, but are not limited to, any or all of pitch (also referred to as dense lines), line-end, dense line-end, H bar, broken H bar, nested U, mirror U, landing-pad, two-T, snake, mushroom, rotated-L, and contact (also referred to as pillar) features. Failure modes that may be evaluated include but are not limited to pinching, bridging, necking, and ringing. The multifeature test pattern may be designed such that only a single exposure and printing of the test pattern per process condition is necessary to collect data for each of the features in the final semiconductor wafer product. The size and resolution of a multifeature test pattern may be determined based on the field of image of an SEM used to take the images and/or measurements of the printed test wafer that are used to validate the OPC model.
[0024] FIGS. 2-8 illustrate embodiments of the multifeature test pattern 100 of FIG. 1 as exposed and printed under various different process conditions. The semiconductor product may be processed under various different dose and focus conditions during production; printed test patterns under such varied conditions, such as FIGS. 2-8 , may be used to verify that the OPC model is valid within a band of accepted process conditions. Printed multifeature test patterns 200 - 800 are shown for illustrative purposes only; a multifeature test pattern may be exposed and printed under any number of different process conditions. FIG. 2 shows a printed multifeature test pattern 200 at a focus of negative 80 nm. Various failure modes are illustrated in multifeature test pattern 200 , including pinching at 201 , bridging at 202 , necking at 203 , and ringing at 204 . FIG. 3 shows a printed multifeature test pattern 300 at a focus of negative 40 nm, and shows how the pinching at 301 , bridging at 302 , necking at 303 , and ringing at 304 vary under the changed focus. FIG. 4 shows a printed multifeature test pattern 400 for OPC at a negative 10% dose, and shows how the pinching at 401 , bridging at 402 , necking at 403 , and ringing at 404 vary under the changed focus. FIG. 5 shows a printed multifeature test pattern 500 at a best focus, and shows how the pinching at 501 , bridging at 502 , necking at 503 , and ringing at 504 vary under the changed focus. FIG. 6 shows a printed multifeature test pattern 600 at a positive 10% dose, and shows how the pinching at 601 , bridging at 602 , necking at 603 , and ringing at 604 vary under the changed focus. FIG. 7 shows a printed multifeature test pattern 700 at a focus of positive 40 nm, and shows how the pinching at 701 , bridging at 702 , necking at 703 , and ringing at 704 vary under the changed focus. FIG. 8 shows a printed multifeature test pattern 800 at a focus of positive 80 nm, and shows how the pinching at 801 , bridging at 802 , necking at 803 , and ringing at 804 vary under the changed focus. Data may be collected from each of printed multifeature test patterns 200 - 800 using, for example, an SEM to take images or perform individual CD measurements.
[0025] FIG. 9 illustrates an embodiment of a method 900 of performing OPC verification using a multifeature test pattern. In block 901 , a multifeature test pattern is generated based on the semiconductor product being modeled using OPC. The multifeature test pattern may include a plurality of features of any appropriate number and type, in any appropriate arrangement. The features on a multifeature test pattern may include, but are not limited to, any or all of pitch, line-end, dense line-end, H bar, broken H bar, nested U, mirror U, landing-pad, two-T, snake, mushroom, rotated-L, and contact features. Failure modes that may be evaluated include but are not limited to pinching, bridging, necking, and ringing. The multifeature test pattern may have a size and resolution determined based on a field of image and resolution of an SEM being used to take images of the printed and exposed test wafers to collect data for the OPC verification process. In block 902 , the multifeature test pattern is put on a test mask that is exposed and printed on a test wafer under a specific process condition. For example, the multifeature test pattern may be exposed and printed under any of the process conditions shown with respect to FIGS. 2-8 , or under any other appropriate process condition. In block 903 , an OPC model of the semiconductor product under the process condition used in block 902 is generated using a computer. In block 904 , the OPC model is compared to the test wafer. The comparison may be performed using image(s) of the test wafer, or measurements of individual CDs of features on the test wafer, taken by an SEM. In some embodiments, only a single image of the test wafer may be required. Modifications to the OPC model may then be determined based on the comparison. In block 905 , blocks 902 - 904 may be repeated for any number of additional different process conditions. This allows determination of whether the OPC model will predict failures if the process conditions are changed.
[0026] The technical effects and benefits of exemplary embodiments include simplification of an OPC verification process by reducing necessary metrology requests and increasing available verification data.
[0027] 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.
[0028] 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.
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A method for optical proximity correction (OPC) model accuracy verification for a semiconductor product includes generating a multifeature test pattern, the multifeature test pattern comprising a plurality of features selected from the semiconductor product; exposing and printing the multifeature test pattern on a test wafer under a process condition; generating an OPC model of the semiconductor product for the process condition; and comparing the test wafer to the OPC model to verify the accuracy of the OPC model.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of U.S. provisional application 60/834,207 filed on Jul. 28, 2006, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a highchair. In particular the invention relates to a highchair with height adjustment, comprising a base arranged to rest on a floor and a seat connected to said base comprising a substantially horizontally extending seat surface, wherein the seat is adjustable in a substantially vertical direction with respect to said base.
BACKGROUND OF THE INVENTION
[0003] Highchairs for children with height adjustment to accommodate for their growth are well-known in the field. Such highchairs are for instance described in U.S. Pat. No. 4,109,961, international patent application publication no. WO 95/30360 and international patent application publication no. WO 2006/031112. In those highchairs the height of the seat surface can be adjusted by moving the seat up and down along two uprights of the base.
[0004] The inventions aims at a highchair that is comfortable and safe, that can be used in many stages of a child's life and that is easy to adjust and use.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the invention the modular highchair comprises a base arranged to rest on a floor, a carrier mounted on said base and adjustable in a substantially vertical direction with respect to said base, and a seat comprising a substantially horizontally extending seat surface connected to said carrier, wherein said carrier extends substantially downward from the front edge of said seat surface. Such an arrangement makes it easy to adjust the height of the seat, and furthermore there is no need for unnecessary parts of the base to extend above the seat surface when the seat is in the lower positions, as the entire base can remain under the seat surface at all heights. Also an empty space is provided between the base and the seat.
[0006] Preferably a backrest extends substantially upward from the rear edge of said seat surface. The height of the backrest thereby does not change when the height of the seat adjusted.
[0007] Preferably said carrier is mounted on and movable up and down along the front side of said base.
[0008] Preferably said carrier extends downward and slightly forward from said front edge of said seat surface. Preferably said carrier forms a leg support of said seat. Preferably said carrier is substantially plate shaped. The carrier is thereby completely integrated in the seat.
[0009] Preferably said base comprises two spaced apart front legs, and preferably said base also comprises two spaced apart rear legs. Preferably said base comprises two spaced apart front legs and a cross member connected to the front legs, wherein said carrier is movable on the cross member. Preferably said front and rear legs are connected by a horizontally extending substantially H-shaped or U-shaped connecting portion. Preferably said connecting portion is substantially U-shaped, wherein the lateral connecting portion of said U-shape extends near the front side of the base, and said carrier is mounted to said lateral connecting portion of said U-shaped connecting portion.
[0010] Preferably the highchair comprises a locking device for locking the seat at a desired height relative to the base, said locking device comprising a lever being formed by a lower portion of said carrier and movable between a locked position wherein said lower portion extends in the lateral plane through the carrier, and an unlocked position wherein said lower portion extends in front of said plane.
[0011] Preferably the lever is a hinged lever mounted on the carrier with at least one cam, and at least one substantially vertical rack mounted on the base having a scalloped surface with ridges and grooves, such that the cam can be rotated around the hinge axis into and out of a chosen groove of the rack in order to lock the vertical movement of the seat. Preferably said lever is hinged at its upper end, and extends downward abutting a fixed portion of the carrier in the locked position. Preferably said lever comprises a secondary lock for locking the lever against the carrier in the locked position. Preferably said secondary lock comprises an operating handle near the lower edge of the lever for operating the secondary lock.
[0012] Preferably said lever is plate shaped and is integrated in the plate shaped carrier in the locked position.
[0013] Preferably said highchair comprises at least one gas spring, one end of which is mounted on the base and the other end of which is mounted on the seat. Preferably said gas spring extends substantially vertically in the carrier.
[0014] Preferably said carrier is mounted on the base by means of at least one substantially vertical guide member mounted on one of said base and carrier and a connector member mounted on the other one of said base and carrier, meshing with said guide member and vertically movable along it. Preferably said connector member is detachably connected to said guide member, such that the seat and carrier is detachable from the base. Preferably the connector member and guide member are arranged such, that the connector member can be lifted from the guide member if the seat is moved beyond the uppermost position.
[0015] According to another aspect of the invention the highchair comprises a base arranged to rest on a floor, a carrier mounted on said base and adjustable in a substantially vertical direction with respect to said base, and a seat comprising a substantially horizontally extending seat surface connected to said carrier, wherein said base entirely extends under the plane of said seat surface.
[0016] According to another aspect of the invention the highchair comprises a base arranged to rest on a floor, a carrier mounted on said base and adjustable in a substantially vertical direction with respect to said base, and a seat comprising a substantially horizontally extending seat surface connected to said carrier, wherein the highchair comprises a locking device for locking the seat at a desired height relative to the base, said locking device comprising a hinged lever mounted on the carrier with at least one cam, and at least one substantially vertical rack mounted on the base having a scalloped surface with ridges and grooves, such that the cam can be rotated around the hinge axis into and out of a chosen groove of the rack in order to lock the vertical movement of the seat.
[0017] According to a further aspect of the invention the highchair comprises a seat made of a substantially rigid material, and removable accessories such as a harness, a bumper bar, a crutch bar and/or a footrest, said seat and accessories comprising attachment means for attaching the accessories to the seat, wherein said attachment means comprises at least one slot in said seat and at least one attachment clip on said accessory that fits into said slot, said clip and slot combination comprising a resilient tongue and edge snap connection that lock said clip into said slot upon insertion, and wherein said slot is formed such, that said snap connection can be released by inserting an unlocking tool into said slot.
[0018] According to a still further aspect of the invention the highchair comprises a base arranged to rest on a floor, a seat comprising a seat member and a leg support member extends downwardly from a front edge of the seat surface, the leg support member is slidable mounted on the base, a locking device mounted between the base and the leg support member and movable between a locked position and unlocked position so as to lock the seat at a desired height relative to the base. Preferably the base includes two inverted U shaped legs and a cross member connected between the two legs, the locking device is mounted on between the cross member and the leg support member. Preferably the locking device includes a lever pivotally connected mounted on the support member with a cam surface, and at least one substantially vertical rack mounted on the base having a scalloped surface with plurality of ridges and grooves, when the locking device is in the locked position, the cam surface is engaged with the one of the grooves to lock the seat at the desired height relative to the base. Preferably the rack is in the form of a T-profile, the leg support member of the seat includes an extrustion mated with the rack so that the leg support member is detachably connected to the base and can slide along the rack
[0019] According to a still further aspect of the invention the highchair comprise a base frame, a seat comprising a seat member and a leg support member extends downwardly from a front edge of the seat surface, the seat is movable mounted on the base and the leg support member includes a main portion and a cover portion pivotally connected to the main portion, wherein the cover portion of the leg support member is moved between a first position where the cover plate is in the same horizontal plane of the main portion and the seat is locked relative to the base in a desired height position; and a second position where the cover plate is pivoted relative to the main portion to an forward position and the seat is free moved relative the base.
[0020] According to a still further aspect of the invention the highchair comprises a base frame includes two inverted U shaped legs and a cross member connected between the two legs, a seat comprising a seat member and a leg support member extends downwardly from a front edge of the seat surface, the leg support member is detachably mounted on the cross member and having a latch clip to prevent the seat from being removed from the base. Preferably the cross member of the base includes a rack in the form of a T-profile, the leg support member of the seat includes an extrustion mated with the rack so that the leg support member is able to slide relative to the base to a desired height position, and the latch is attached to the extrusion so as to extend under the T-profile.
[0021] Further aspects of the invention and advantages thereof are described in the following detailed description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be further explained by means of the preferred embodiment as shown in the accompanying drawings, wherein:
[0023] FIGS. 1 A/B/C shows perspective views of a modular highchair with accessories in accordance with the invention;
[0024] FIG. 2 shows a perspective exploded view of the modular highchair with accessories of FIG. 1 ;
[0025] FIG. 3 shows a perspective view of the disassembled modular highchair of FIG. 1 in a box;
[0026] FIG. 4 shows a top view of the guide member as shown in FIG. 3 ;
[0027] FIGS. 5 A/B shows perspective views of the secondary locking mechanism of the highchair of FIG. 1 ;
[0028] FIG. 5C shows a cross-section of the carrier with the secondary locking mechanism and the footrest of the highchair of FIG. 1 ;
[0029] FIG. 6 shows a partly open perspective view of the carrier with locking mechanism of the highchair of FIG. 1 ;
[0030] FIG. 7 A/B shows a cross-section of the carrier with the locking mechanism of the highchair of FIG. 1 ;
[0031] FIG. 8 shows a perspective view of a detail of the carrier with footrest of the highchair of FIG. 1 ;
[0032] FIG. 9A shows a perspective cross-section of the connection of the bumper bar with the backrest of the highchair of FIG. 1 ;
[0033] FIG. 9B shows a perspective view of the connection of the crutch bar with the seat surface of the highchair of FIG. 1 ;
[0034] FIG. 9C shows a perspective view of a detail of the highchair of FIG. 1 with bumper bar, crutch bar and tray;
[0035] FIG. 10A shows a perspective view of the harness of the highchair of FIG. 1 ;
[0036] FIGS. 10 B/C show perspective cross-sections of the buckle of the harness of FIG. 10A ; and
[0037] FIGS. 11 A/B show a perspective cross-sections of the connection between the harness and the seat of the highchair of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] In the figures is shown a highchair 1 that has height adjustment, and a number of removable components that give the highchair modularity. The highchair 1 comprises of a seat 2 , a base 3 and a number of removable components such as a footrest 4 , tray table 5 , a harness 6 complete with buckle 7 , a combined bumper/crutch bar 8 , 9 , and a cushion 10 . The base 3 forms the legs 11 , 12 , 12 , 14 of the chair 2 and the seat 2 moves vertically over the front of the legs 11 , 12 to provide the height adjustment. The seat 2 is locked in position vertically by means of a mechanism 15 such as an over centre cam 1501 which clamps onto a component of the base 3 . The form of the seat 2 consists of a seat surface 201 , an upwardly extending back surface 202 and a downwardly extending leg surface 203 . The base 3 consists of two inverted U shaped legs 301 , 302 with a cross member 303 that runs between the two front straight sections of the legs. The leg surface 203 of the seat 2 is connected to this cross member 303 and can slide vertically over this surface when the mechanism lock 15 , which comprises for example an over centre cam 1501 , is released. The height adjustment movement is assisted by means of motion control hardware, such as gas springs 1502 .
[0039] As shown in FIGS. 1 and 2 the highchair comprises of a seat 2 , a base 3 and a number of removable components such as a footrest 4 , tray table 5 , a harness 6 complete with buckle 7 , a combined bumper/crutch bar 8 , 9 , and a cushion 10 .
[0040] The form of the seat 2 consists of a seat surface 201 , an upwardly extending back surface 202 and a downwardly extending leg surface 203 . The seat exterior is made from, for instance, an injection moulded plastic, such as Polypropylene, and consists of two major parts, a front shell 204 and a back shell 205 . An internal frame 206 is sandwiched between these two shells 204 , 205 and the three parts are fastened together, preferably using a combination of snaps 207 and screws as shown in FIG. 6 . The internal frame 206 is made from, for instance, folded sheet steel. This internal frame 206 provides some additional rigidity to the seat 2 and has a further two functions. The first is to provide the height adjustable connection between the seat 2 and the base 3 and the second is to house the axle 1503 for the rotating the mechanism 15 , which comprises for example an over centre cam component 1511 , that locks the height adjustment as shown in FIGS. 5C , 6 and 7 A/B. A section of the leg surface 203 of the front and back shells 204 , 205 is open and a separate moveable cover 208 fills the gap. This moveable cover 208 is attached to the over centre cam (or similar) component 1511 . The moveable cover 208 and the cam component 1501 are made, for instance, from injection moulded polypropylene. The cam component 1511 and the moveable cover 208 fit together to form the height adjustment lock handle assembly 15 as shown in FIGS. 5C , 6 and 7 A/B. This part also houses a secondary latch assembly 1504 . The secondary latch assembly 1504 is comprised of a lever handle 1505 and a latch 1506 and is attached to the back of the moveable cover 208 . The latch 1506 and lever handle 1505 are, preferably, injection moulded polypropylene components. A compression spring 1508 , or similar actuating component, fits between the moveable cover 208 and the latch 1506 to keep the latch 1506 in the upward (locking) position. When the moveable cover 208 is rotated to its lock position (flush with the front and back shells 204 , 205 ) the latch 1506 fits behind a section of the internal frame 206 . The latch 1506 also contains an angled surface 210 as shown in FIG. 5C so that the internal frame 206 pushes the latch 1506 down when the moveable cover 208 is rotated to the locked position. The back shell 205 incorporates two long slots 211 , behind which are, for instance, two aluminium extrusions 212 , 213 that are fastened to the internal frame 206 . Inside both of the slots 211 are located gas springs 1502 (or similar devices). The top end fittings of the springs 1502 are retained by the back shell 205 and the internal frame 206 . The lower end of the gas spring 1502 , the pin, has a small rounded or chamfered plastic cap to aid in the assembly of the seat 2 to the base.
[0041] The base 3 as shown in FIGS. 2 and 3 consists of two inverted U shaped components 301 , 302 which create four legs 11 , 12 , 13 , 14 with a single cross member 303 that runs between the front two ‘legs’ 11 , 12 . The two inverted U shaped components 301 , 302 are made from, for instance, rectangular Aluminium extrusion that is bent to comprise three straight sections and two radii. Each inverted U component 301 , 302 provides a front and back leg. The front and back legs 11 , 12 , 13 , 14 are not parallel and the angle between the top of the inverted U shape and the legs on either side is greater than 90 degrees. The two inverted U shape components 301 , 302 are separated by a cross member 303 that fits between the two front ‘legs’ 11 , 12 . The two inverted U shape components 301 , 302 are also not parallel with each other as they are angled outwards at the foot end. The cross member 303 is, for instance, a folded sheet steel component with an injection moulded polypropylene cover. The cross member is fastened between the two front legs 11 , 12 . Four feet 1101 , 1201 , 1301 , 1401 are fitted into the cut ends of the legs 11 , 12 , 13 , 14 . The feet are likely to be made from injection moulded polypropylene. Fastened to the cross member 303 are two injection moulded T-profiles 304 , 305 as shown in FIGS. 3 and 4 , which are for instance made from POM or Nylon. These two profiles 304 , 305 are made to fit inside the two aluminium extrusions 212 , 213 that are attached to the internal frame 206 of the seat. The T-profiles 304 , 305 , in length, are longer than the height adjustment range. They have a recess 306 down the middle to house the gas spring 1502 (or similar device) and they have a scalloped surface section 307 on which the cam component 1501 clamps against. The top end is chamfered to provide ease of assembly.
[0042] On assembly of the seat 2 and the base 3 , the two aluminium extrusions 212 , 213 in the seat 2 are slid over the two T-profiles 304 , 305 of the base. As this is done, the pin end of the gas springs 1502 complete with end caps comes into contact with the end wall of the T-profiles 304 , 305 and this begins to compress the gas spring 1502 . When the seat 2 reaches its highest most lockable position in relation to the base 3 , two plastic latch fingers 214 clip under each T-profile 304 , 305 to prevent the seat from being removed again accidentally. These plastic latch fingers 214 are attached, for example, to the aluminium extrusions 212 , 213 of the seat frame work.
[0043] In addition there are a number of removable parts. There is a footrest 4 as shown in FIGS. 2 and 8 which will be made for instance using gas assisted injection moulding of polypropylene. This is attached to the height adjustable lock handle assembly 15 , and therefore moves with it. When the height adjustable lock handle assembly 15 is in the unlocked position, the foot rest 4 can be easily removed by flexing it open. Two protrusions 401 fit into two slots 1509 in the cam component 1511 .
[0044] There is also a bumper bar 8 as shown in FIGS. 2 and 9 A/B that is permanently attached to a crutch bar 9 by means of snaps for example. The ends of the bumper bar 8 are rotated into through-holes 215 in the back surface 202 of the seat 2 . A small protrusion 801 on the ends of the bumper bar 8 fits into a small recess 217 in the through-holes 215 in the back surface 202 , thereby holding the bumper bar/crutch bar 8 , 9 assembly in place when the crutch bar 9 is clicked in place. The crutch bar 9 has a flexible snap 901 which, when the end of the crutch bar 9 is pressed into a through-hole 219 in the seat surface 201 of the seat 2 , clicks into place locking the whole assembly. By pushing on a section 902 of the crutch bar 9 the snap 901 is pushed back and the crutch bar/bumper bar 8 , 9 can be removed. These parts are to be made from, for instance, gas assisted injection moulding of polypropylene.
[0045] As shown in FIGS. 2 , 10 A and 11 A/B there are five attachment clips 601 that allow attachment of the harness 6 to the seat. These attachment clips 601 fit into through-holes 220 in the back surface 202 and seat surface 201 and are held in place by a snap 602 moulded into each attachment clip. To remove the harness 6 a tool 618 needs to be inserted from the back/underside of the seat 2 to release the snap 602 . There are two attachment clips 601 for the left and right shoulders 603 , 604 , two for the left and right waist 605 , 606 positions and one for the crutch position 607 . These attachment clips 601 are to be, for instance, made from injection moulded polypropylene. A soft webbing is used for the harness 6 . Three lengths are used. One length runs from the left shoulder to the left waist position and contains a buckle clip 608 . One length runs from the right shoulder to the right waist position and also contains a buckle clip 609 . The other length joins the crutch attachment clip 610 to the buckle 7 . The buckle 7 as shown in FIGS. 10 A/B/C, including the two buckle clips 608 , 609 , is made from five plastic components that are for instance made from injection moulded ABS (Acrylonitrile Butadiene Styrene). There is the front half 701 and back half 702 , which comprise the buckle housing; a flexible button 703 ; and two buckle clips 608 , 609 that each contain a flexible snap 615 , 616 . When the button 703 is compressed, it causes the flexible snaps 615 , 616 to release from behind a rib 704 in the front half 701 . Two compression springs 705 are incorporated to propel the buckle clips 608 , 609 out of the buckle housing upon compression of the button 703 .
[0046] A tray table 5 fits over the bumper 8 bar as shown in FIGS. 1A , 2 and 9 C. Two protruding ribs 501 , 502 fit into the through-holes 215 of the back surface 202 of the seat 2 along side the bumper bar ends. Two tray snaps 503 , 504 are located in the inside edge of the tray and click to the bumper bar 9 . To release the tray 5 these snaps 503 , 504 are bent rearwards and then the tray 5 can be pulled up and away from the seat 2 . This part will be made for instance from injection moulded polypropylene. A removable foam cushion 10 as shown in FIGS. 1 A/B/C and 2 can be added to the seat 2 for small babies.
[0047] The cube size of a product, prior to being purchased by a consumer, needs to be minimised to make best use of shipping container capacity and to minimise storage requirements. In order to minimise the cube size of the boxed highchair 1 , the seat 2 and the base 3 are produced as two separate parts which allows them to be nested together in a box and therefore conserve space, as shown in FIG. 3 .
[0048] It is desired that a consumer be able to assemble the highchair 1 with ease without following extensive instructions and without the need for tools. It is also preferable that a consumer be able to disassemble the highchair 1 and return it to its original box should they need to return the product to the factory for repair, be moving house or want to put the product into storage. However this should only occur through a deliberate action. Disassembly should not occur by accident.
[0049] The two parts are easily fitted together by the consumer by first fully opening the height adjustment lock handle assembly 15 and then sliding the two aluminium extrusions 212 , 213 in the back of the seat 2 over the two T-profile components 304 , 305 of the base. Two gas springs 1502 will begin to exert a force as the seat 2 is pushed over the profiles 304 , 305 . As the seat reaches its highest lockable position in relation to the legs 11 , 12 , 12 , 14 , a “click” sound will be heard indicating that the seat 2 is now attached to the legs 11 , 12 , 13 , 14 . The seat 2 and legs 11 , 12 , 13 , 14 can now only be separated when required only through a deliberate action.
[0050] Incorporated into the seat 2 are two aluminium extrusions 212 , 213 or similar. These two parts slide over the two T-profiles 304 , 305 that are attached to the cross member 303 between the legs 11 , 12 , 13 , 14 of the base. Two gas springs 1502 (or similar devices) are situated in the centre of each of the two pieces of aluminium extrusion 212 , 213 and these fit inside the two T-profiles 304 , 305 when the seat 2 is assembled onto the base 3 . One end of each of the gas springs 1502 is connected to the seat 2 and as the seat 2 is assembled on to the base 3 the other end of each of the gas springs 1502 makes contact with the end wall of the T-profiles 304 , 305 . When the seat 2 is pushed down to its highest lockable position with relation to the leas 11 ; 12 , 13 , 14 , four plastic latch fingers 214 (that are elastically deformed during the assembly) snap back into position preventing the seat 2 from being removed from the base 3 . These must be pushed apart before the seat 2 can again be removed from the base 3 .
[0051] The consumer would like their purchase to serve them for as long a time as possible. By adding a height adjustment mechanism to a high chair 1 , the chair 1 can be used for a longer period of time. The chair 1 is able to be lowered as the child grows. Also the height adjustment allows for the parent to adjust the chair 1 should they want to feed the baby while they are themselves, for example, seated on a couch.
[0052] Should the consumer fail to lock the height adjustment mechanism, through normal use of the highchair 1 , the mechanism should lock itself. It should also be visually obvious to the consumer whether or not the highchair 1 height position is locked. It is furthermore desired that the height be adjustable to any chosen position between the highest and lowest available positions rather than restricting adjustment to only a few positions. It is also required that the height adjustment be easily performed by an adult using both hands. It is also important that the height adjustment can not be accidentally released by either the child in the high chair 1 or a sibling. Furthermore it is desired when the height is locked that any play between the seat 2 and the base 3 will be removed or at least minimised so that there is no rattling or feeling of instability/flexibility that would serve to give the chair 1 an unsafe feel.
[0053] The locking function as shown in FIGS. 5 A/B/C, 6 and 7 A/B consists of a primary and a secondary locking device 15 , 1504 . The primary locking device 15 uses, for instance, an over centre cam quick-release type lock. The cam 1501 is positioned so that when a load is applied to the chair 1 the cam 1501 will rotate to the locked position. This means that whenever a child is seated in the chair 1 the weight of the child will cause the mechanism to lock. When locking, the cam 1501 comes into contact with a scalloped surface 307 on the T-profile 304 , 305 . The scalloped surface 307 is used to increase the contact area between the cam 1501 and the clamping surface and also increases the vertical component of force, to oppose forces that would initiate movement in the upwards or downwards directions. When the cam 1501 is in the locked position it pushes firmly against the T-profile 304 , 305 , thereby removing any play between the seat 2 and the base 3 and creates a rigid structure.
[0054] When the height adjustment lock handle assembly 15 is in the unlocked position, it is sticking out from the leg surface 203 of the seat 2 . Therefore it is obvious to the user if the seat 2 is not in the locked position.
[0055] Because a cam type mechanism is used rather than the more usual pin/hole type mechanism, there is less limitation in the number of positions available for the seat 2 to be set at. The addition of gas springs 1502 (or similar devices), which gently propel the seat 2 in the upward direction when the cam 1501 is released, simplifies the height adjustment. The user can push down on the seat 2 with one hand and when the desired height is achieved can then lock the seat 2 using the other hand.
[0056] Without gas springs 1502 (or similar devices) the user would need to pull the seat 2 up to the desired position which is a more difficult action. This would create the possibility that the whole chair 1 is lifted off the floor rather than only the seat 2 being moved upward or the possibility that the seat 2 is pulled on one side only, which could lead to the seat 2 becoming skewed and adjusting would then become difficult.
[0057] The prevention of accidental release is provided through a secondary latch 1504 which must first be released before the height adjustment lock handle assembly 15 can rotate. The secondary latch 1504 is released by sliding the lever handle 1505 down as shown in FIG. 5 A/B. The rotating follows the sliding movement providing a smooth secession of movements rather than two disjointed movements.
[0058] As described previously, the seat 2 contains, for instance, two aluminium extrusions 212 , 213 which slide over two T-profiles 304 , 305 that are attached to the cross member 303 between the legs 11 , 12 , 13 , 14 of the base 3 . In the centre of the extrusion 212 , 213 there is a cut-out which allows the cam 1501 from the cam component 1511 to protrude through. The two T-profiles 304 , 305 on the cross member 303 of the legs 11 , 12 , 13 , 14 have a scalloped surface 307 which the cam 1501 makes contact with when in the locked position. The cam component 1511 itself is attached to the moveable cover 208 . Inside of the plastic seat shells 204 , 205 is the internal frame 206 which contains the axles 1503 that the cam 1501 (and height adjustable lock handle assembly 15 ) rotate about. The secondary latch 1506 is located on the back of the height adjustable lock handle assembly 15 and can be slid downwards with the fingers, allowing the cam 1501 to be rotated. When in the upwards position the latch 1506 fits behind a section of the internal frame 206 which prevents the rotating of the cam 1501 . When the lever 1505 is moved downward the latch 1504 is also moved and the cam 1501 is then free to rotate. A compression spring 1508 fits between the moveable cover 208 and the latch 1506 to keep the latch 1506 in the upward (locked) position. The latch 1506 is pushed down by the seat's internal frame 206 pushing against an angled section 210 of the latch 1506 .
[0059] As well as suiting a range of ages it is desirable for the child's caregiver that the highchair 1 can be modified to suit the particular child's needs as well as those of the caregiver.
[0060] The tray 5 should be removable for cleaning and the highchair 1 should still be able to be used without the tray 5 . Also the relevant Standards state that a crotch bar 9 is mandatory when the tray table 5 is in use. For small babies a harness 6 is desired but this should be able to be removed for bigger children. It is desired that both the footrest 4 and bumper bar 8 be removed when they are no longer required.
[0061] The seat can be easily changed as the baby grows and their needs change. The high chair 1 can be converted from a standard baby's high chair 1 to a normal child's chair 1 by removing the different components as shown in FIG. 1 . The tray 5 can only be used when the crotch bar/bumper bar 8 , 9 is in place thereby complying with the Standards. Once the tray table 5 is removed, the crotch bar/bumper bar 8 , 9 is still in place giving extra versatility to the high chair 1 .
[0062] A soft cushion 10 is included in the design for very young children. When the child is bigger this can be removed by first removing the harness 6 . The harness 6 is attached to the chair 1 by means of attachment clips 601 that can only be removed by use of a tool 618 . The tool 618 must be inserted into the slots 220 in the back shell of the seat 2 and this in turn pushes a flexible snap 602 of the attachment clip 601 away allowing the attachment clip to be released. The tray 5 is easily removed by first releasing the tray snaps 503 , 504 on the inside of the tray 5 and then sliding the tray out of the slots 215 in the back surface of the seat 2 . The bumper bar 8 is released in a similar manner. There is a snap 901 in the crutch bar 9 that is released by pressing on a flexible section 902 of the bar 9 . This then allows the crutch bar 9 to be pulled out. The bumper bar 8 can then be rotated out of the slots 215 in the back surface of the seat 2 . The foot rest 4 can be removed by first releasing the height adjustment lock handle assembly 15 , and then the foot rest 4 can be detached one side at a time by pulling the footrest 4 open.
[0063] Buckles that are complicated to fasten are less likely to be used by the caregiver. It is desirable that the harness buckle 7 be simple and easy to use by the caregiver. The buckle 7 is attached to the length of webbing that fits between the child's legs. Two buckle clips 608 , 609 are attached to two lengths of webbing, one that goes over the left shoulder of the child and to the left of the child's waist and one that goes over the right shoulder of the child and to the right of the child's waist. The two buckle clips 608 , 609 can be clipped independently into the buckle 7 .
[0064] The buckle 7 is made from five plastic components. The front half 701 and back half 702 of the buckle 7 , which comprise the buckle housing; a flexible button 703 and two buckle clips 609 , 610 containing a flexible snap 615 , 616 that is flexed on compression of the button 703 and is released from behind a rib 704 in the back half 702 . Two compression springs 705 are incorporated to propel the clips 608 , 609 out of the buckle housing on compression of the button 703 .
[0065] Although the invention is described herein by way of the preferred embodiment as an example, the man skilled in the art will appreciate that many modifications and variations are possible within the scope of the invention.
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A highchair comprising a base arranged to rest on a floor, a carrier mounted on said base and adjustable in a substantially vertical direction with respect to said base, and a seat comprising a substantially horizontally extending seat surface connected to said carrier, wherein said carrier extends substantially downward from the front edge of said seat surface.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The invention lies in the field of sheet-processing machines. More specifically, the invention relates to a sheet feeder for a sheet-processing machine, such as a sheet-fed printing press.
[0002] In sheet feeders having a clutch for the drive connection to the sheet processing machine, such as a printing press, there exists the problem that the sheet feeder is not usually connected until the printing press has a very high operating speed. A joltlike drive torque caused by the coupling process firstly stresses the drive means with a torque surge and leads to heavy wear of the drive, as well as of driven components and the driving components.
[0003] To solve the above-described problem, German published patent application DE 100 40 070 A1 discloses a switchable sheet feeder which, in addition to the actual feeder clutch, has an additional torsionally elastic clutch that diminishes the coupling surge. In order to suppress oscillations between the machine and the feeder in operation, the torsionally elastic clutch is bypassed via a further, torsionally rigid clutch after the coupling process.
[0004] A clutch configuration of that type, however, is complicated in construction terms and it is relatively expensive.
SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a sheet feeder for a sheet-processing machine which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides for a sheet feeder that can be coupled in and has a device for absorbing the torque surges caused by the coupling process.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a sheet feeder for the synchronized feeding of sheets to a sheet processing machine having a machine drive, the sheet feeder comprising:
[0007] drive assemblies for driving the sheet feeder and a drive train connecting the drive assemblies to the machine drive of the sheet processing machine;
[0008] a clutch selectively switchable with a determined angular position into the drive train between the drive assembly of the sheet feeder and the machine drive of the sheet processing machine; and
[0009] a switch-on torque limiter with a pretensioned spring element connected in the drive train.
[0010] Arranging a switch-on torque limiter according to the invention in the drive train of the feeder leads to a reduction of the torque surge when coupling the feeder to the rotating machine, for example sheet processing machine, in particular printing press, while ensuring the correct phase relation between the latter in operation and reducing oscillations between the feeder and machine.
[0011] In one advantageous refinement, a pretensioned elastic element is incorporated into the drive train, which becomes active after a threshold load is exceeded (for example during the coupling process) and limits the torque surge.
[0012] This threshold load is higher than the torques to be transmitted during feeder operation, so that the elastic element is not effectively loaded and the feeder is rigidly coupled to the machine.
[0013] In one advantageous development of the subject matter of the invention, it is possible to integrate the switch-on torque limiter into a phase adjusting mechanism.
[0014] In accordance with an added feature of the invention, the switch-on torque limiter is disposed between the machine drive of the sheet processing machine and the clutch. Alternatively, the switch-on torque limiter is disposed between the clutch and the drive assemblies of the sheet feeder.
[0015] In accordance with a specific embodiment of the invention, the switch-on torque limiter includes four stationary and symmetrically disposed deflection rollers and two displaceable deflection rollers.
[0016] Furthermore, there may be provided an endless belt that is part-way wrapped around each of the deflection rollers (the four stationary deflection rollers and the two displaceable deflection rollers).
[0017] In accordance with another feature of the invention, there is provided a carriage that supports the displaceable deflection rollers, and a second spring element holding the carriage in a pretensioned state in an operating position.
[0018] In accordance with again a further feature of the invention, the first above-mentioned pretensioned spring element configured to absorb a torque surge introduced when the machine drive is first connected to the drive assemblies of the sheet feeder, and a second spring element is configured to cushion a recoil movement of the switch-on torque limiter.
[0019] In accordance with a preferred embodiment of the invention, the first spring element and the second spring element are disposed coaxially inside one another.
[0020] In accordance with a concomitant feature of the invention, an actuating motor is operatively associated with the carriage for adjusting the carriage specifically to adjust a phase between the machine drive and the drive assemblies of the sheet feeder. Specifically, the actuating motor is operatively associated with the carriage for adjusting a phase between a pinion of the machine drive and a pulley wheel in the drive train.
[0021] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0022] Although the invention is illustrated and described herein as embodied in a sheet feeder having a drive for the synchronized feeding of sheets to a sheet processing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0023] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a diagrammatic representation of a section taken through a sheet-fed rotary printing press;
[0025] [0025]FIG. 2 is a diagrammatic representation of a section through a drive for the feeder of the sheet-fed rotary printing press;
[0026] [0026]FIG. 3 is a diagrammatic view of the switch-on torque limiter according to the invention in the switched operating state of the feeder;
[0027] [0027]FIG. 4 is a similar view of the switch-on torque limiter during absorption of the switch-on torque surge; and
[0028] [0028]FIG. 5 is a similar view of the switch-on torque limiter during the cushioning of the recoil movement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a rotary press, e.g. a printing press 1 which processes sheets 7 , has a feeder 2 , at least one printing unit 3 or 4 and a delivery 6 . The sheets 7 are taken from a stack of sheets 8 , a sheet pile 8 , and, separated or overlapped, are fed over a feed table 9 to the printing units 3 and 4 . Each of the printing units 3 , 4 contains a respective plate cylinder 11 , 12 . The plate cylinders 11 and 12 each have a device 13 , 14 for fastening flexible printing plates. Furthermore, each plate cylinder 11 , 12 is assigned a device 16 , 17 for semiautomatic or fully automatic printing plate change.
[0030] The sheet pile 8 is stacked on a pile board 10 which can be raised under control. The removal of the sheets 7 takes place from the top of the sheet pile 8 by way of a suction head 18 , which inter alia has a number of lifting and dragging suckers 19 , 21 to separate the sheets 7 . Furthermore the blowing devices 22 for loosening the top sheet layers and sensing elements 23 for tracking the stack are provided. In order to align the sheet pile 8 , in particular the top sheets 7 of the sheet pile 8 , a number of side and rear stops 24 are provided.
[0031] The sheet feeder 2 is driven from a drive shaft 26 of the machine drive. A switchable clutch 27 connects the drive of the sheet-processing machine 1 to the drive assemblies of the sheet feeder 2 , for example the drive 28 for the suction head mechanism and air control means; a drive 29 for the intermittently operated roller and flap shaft; and a drive 31 for the transport belt. The drive shaft 26 is provided with a pinion 32 for an endless belt 33 . The belt 33 wraps around a pulley wheel 34 of the clutch 27 .
[0032] A device for absorbing a torque surge of the belt 33 is disposed on a side frame 36 . The device will be referred to as a “switch-on torque limiter 37 ” in the following text. It substantially comprises four stationary deflection rollers 38 , 39 , 41 , 42 that are symmetrically arranged and two further, non-stationary deflection rollers 43 , 44 . It will be understood that the term “stationary” refers to the respective axes of the rollers only. The rollers are rotatably supported. The rollers 43 , 44 can be displaced together. The rollers 43 , 44 are disposed on a displaceable carriage 46 . The belt 33 is wrapped around all the deflection rollers 38 , 39 , 41 , 42 , 43 , 44 . In the drive direction shown in FIGS. 3 to 5 (counter-clockwise), the deflection roller 44 is disposed in the region of the load run and the deflection roller 43 is disposed in the region of the empty run.
[0033] At its end adjacent to the deflection roller 44 , the carriage 46 has a guide 47 with a stop 48 for a first spring element 49 . The spring element 49 is configured as a helical spring, and one end of it is supported on the stop 48 and the other end is supported on a plate 51 which can be displaced along the guide 47 . As the spring element 49 is installed in a pretensioned state (approximately 2 to 3 times the operating moment), it pushes the plate 51 against a stop 50 of a housing 53 . A second spring element 52 encloses the spring element 49 , and one end of the former is likewise supported on the plate 51 and the second end is supported on the housing 53 which encloses the spring elements 49 , 52 , the plate 51 and the guide 47 . The second spring element 52 is also constantly in a pretensioned state. When the sheet feeder 2 or its stationary drive assemblies are coupled to the sheet processing machine 1 which is already rotating at a rotational speed, the result is a not inconsiderable torque surge which acts on the belt 33 . The load is applied here to the load run. This tension leads to the deflection roller 44 being deflected upward in the direction of the arrow in FIG. 4. Together with the carriage 46 and the deflection roller 43 , said deflection occurs counter to the force of the first spring 49 . As a result of this measure, the torque surge is absorbed by the spring deflection when the sheet feeder 2 is coupled in, that is to say it is limited to an amount which corresponds to the spring force.
[0034] [0034]FIG. 4 shows the carriage 46 extended upward counter to the force of the first spring element 49 . The carriage 46 is pressed back into the operating position by the action of the first spring element 49 . Here, as shown in FIG. 5, the carriage 46 swings beyond the operating position, to be precise in such a manner that the second spring element 52 is now compressed, while the first spring element 49 is relieved to its original pretensioned state. The carriage can thus oscillate back and forth a number of times, depending on the magnitude of the coupling torque. After a short time, the switch-on torque limiter 37 is again situated in its stationary initial position, the operating position. Here, the pretensioned spring elements 49 , 52 are designed to be so stiff that operational torques cannot lead to a deflecting movement of the carriage 46 .
[0035] In the preferred exemplary embodiment, the switch-on torque limiter 37 is also simultaneously used as a phase adjusting mechanism. There is provision here for the housing 53 to be provided with an actuating motor 56 via a gear mechanism 54 , for example a threaded rod and hole. The actuating movement is transmitted to the carriage 46 via the stiffly designed second spring element 52 and therefore ensures specific deflection of the load run and empty run which results in phase adjustment of the drive pinion 32 with respect to the pulley wheel 34 .
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In a sheet feeder for a sheet processing machine, such as a sheet-fed rotary printing press, and initial torque spike when the sheet feeder is first switched into the system is reduced with a switch-on torque limiter. The torque limiter is disposed in the drive train between the sheet processing machine and the sheet feeder, so that a torque surge which occurs when the sheet feeder is coupled in at an increased basic speed of the sheet processing machine can be absorbed.
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FIELD OF INVENTION
[0001] The subject of this application relates generally to the field of electronic device manufacturing and, more particularly, to improving solder attach applications.
BACKGROUND OF INVENTION
[0002] As integrated circuit fabrication technology improves, manufacturers are able to integrate additional functionality onto a single silicon substrate. As the number of these functionalities increases, however, so does the number of components on a single chip. Additional components add additional signal switching, in turn, creating more heat. The additional heat adds to the already-existing thermal expansion issues.
[0003] Thermal expansion differences between a semiconductor device and a system motherboard have been a fundamental problem facing the semiconductor industry. Generally, a semiconductor package provides a device with electrical connection to the motherboard, heat dissipation, and mechanical and environmental protection. As part of the mechanical protection function, the package can provide a solution to the thermal mismatch issue between the device and the motherboard.
[0004] During normal operation, the device is expected to survive a fairly wide range of temperature fluctuations. While undergoing these fluctuations, if the device expands and contracts at one rate while the package and/or board move at vastly different rates, a great deal of stress can be generated within the combined structure. These stresses can produce failures within the components themselves or at any of the interfaces between these components.
[0005] An attach design that is quickly gaining acceptance by semiconductor industry is flip chip. Flip chip technology generally places chips on circuit boards face side down. The chips are then connected to circuits by small “bumps” of solder. This configuration eliminates wire bonding and allows shorter interconnections between circuits and components to provide more robust, lighter, smaller, and faster networks. An ever-increasing number of semiconductor manufacturers are adapting flip chip designs, in part, because of the increasing number of I/Os employed in devices.
[0006] As the number of I/Os for each device increases, there is correspondingly less space to place the I/Os around the periphery of a device. To solve this problem, many semiconductor manufacturers are moving to full area array or partial area array I/O designs. Such designs, in turn, increase the need for the advantages provided by a flip chip process.
[0007] Unfortunately, no method of device to package attach seems to be more sensitive to thermal expansion problems than flip chip. This sensitivity is, in part, based on the flip chip technology requiring a small bump size, which brings the die very close to the package. This lack of distance combined with the rigid nature of the solder results in a high stress interconnect when the CTE is not matched. In addition, as the device size grows, the problem becomes worse because as the distance from neutral point grows, the relative movement (or strain) increases.
[0008] A classic question facing the package designers is: Should the package thermal expansion be matched to the device or to the motherboard. Both approaches have been employed with varying degrees of success throughout the industry. If the package is matched more closely to the device, then the attachment method between the board and the package must be compliant enough to absorb the movement. Typical solutions include sockets, pins, solder columns, and interposers. All of these can provide a compliant interface either with the materials themselves or sufficient distance (i.e. stand off) between the package and board. Each of these methods, however, has drawbacks.
[0009] In the case of sockets, there exists a significant cost versus electrical performance trade off. A socket, which adds marginally to the overall costs, can significantly degrade electrical performance. In addition, these sockets usually require pins to be placed on the package, adding cost and process steps. Conversely, a socket which does not degrade electrical performance or require pins can cost as much as the package itself. In addition, these types of sockets typically require a great deal of force to be placed on the package to ensure good socket contact. This can limit the mechanical and thermal design solutions.
[0010] Solder columns provide another solution by providing the proper stand off with good electrical connection, but are difficult to process and limited in supplier base. Another approach is to make use of solders with different melting, or re-flow, temperatures. Components within the solder attach method can be designed with higher melting solders. These can act as a stand off to maintain a greater distance between the package and motherboard because they would not melt and collapse during the normal board mount process. This method adds complications to the assembly process.
[0011] The interposer solution is relatively untested and is inherently undesirable because it, like sockets, adds a component to the assembly process and bill of materials.
[0012] If the package is matched thermally to the board, then the attachment method between device and package must absorb the inherent stresses. Presently, this method is achieved by using an epoxy, or epoxy like material, called an under-fill which is dispensed between the device and the package after the flip chip attach is completed. The under-fill acts to absorb stresses. This method, however, can be employed successfully for relatively small devices. Unfortunately, as the devices grow larger, even the under-fill cannot reduce the stresses to non-lethal levels. A great deal of process and material development will be required to achieve success with a larger die.
SUMMARY OF INVENTION
[0013] The present invention includes novel methods and apparatus to provide dynamic solder attach, in part, to decrease the affects of thermal variations. In an embodiment, an apparatus is disclosed. The apparatus includes a semiconductor package, a device to be attached to the semiconductor package, a spacer to provide a gap between the semiconductor package and the device, an attachment material disposed between the device and the semiconductor package, and an environmental control device to provide an appropriate environment to activate the attachment material.
[0014] In another embodiment, while the attachment material is substantially activated, the spacer increases the gap between the semiconductor package and the device to elongate the attachment material in a plane substantially perpendicular to the device and the semiconductor package.
[0015] In yet a different embodiment, the elongated attachment material assumes a substantially hourglass shape.
[0016] In various embodiments, the apparatus may further include any of the following:
[0017] a stopper to limit the increase of the gap once a desired size of the increased gap is reached;
[0018] a locking device to lock in the spacer once a desired size of the increased gap is reached;
[0019] a brake to maintain the gap at a desired size;
[0020] a computing device to actuate the brake; and/or
[0021] an aligner to align the semiconductor package and the device.
[0022] In a different embodiment, a novel method is disclosed. The method includes providing a spacer to control a gap between a semiconductor package and a device, providing attachment material between the device and the semiconductor package, positioning the device and the semiconductor package adjacent to each other to provide substantial contact between the device and the semiconductor package via the attachment material, providing an appropriate environment to activate the attachment material, and utilizing the spacer to increase the gap between the semiconductor package and the device while the attachment material is substantially activated.
[0023] In a further embodiment, the attachment material is elongated in a plane substantially perpendicular to the device and the semiconductor package.
[0024] In yet another embodiment, the elongated attachment material assumes a substantially hourglass shape.
[0025] In yet a different embodiment, the attachment material conducts electricity.
[0026] In a certain embodiment, the method further includes actuating a brake to maintain the gap at a desired size.
BRIEF DESCRIPTION OF DRAWINGS
[0027] The present invention may be better understood and its numerous objects, features, and advantages made apparent to those skilled in the art by reference to the accompanying drawings in which:
[0028] [0028]FIG. 1A illustrates an exemplary partial cross-sectional view of a device 100 in accordance with an embodiment of the present invention;
[0029] [0029]FIG. 1B illustrates an exemplary partial cross sectional view of the device 100 of FIG. 1A after the solder balls 106 are elongated;
[0030] [0030]FIG. 2A illustrates an exemplary partial cross sectional view of a device 200 in accordance with an embodiment of the present invention;
[0031] [0031]FIG. 2B illustrates an exemplary partial cross sectional view of the device 200 of FIG. 2A after heat is applied to put the solder balls 106 in there reflow state;
[0032] [0032]FIG. 3A illustrates an exemplary partial cross sectional view of a device 300 in accordance with an embodiment of the present invention;
[0033] [0033]FIG. 3B illustrates an exemplary partial cross sectional view of the device 300 after the lifting mechanism 130 increases the distance between the motherboard 102 and the semiconductor package 104 ;
[0034] [0034]FIG. 4 illustrates an exemplary partial cross sectional view of a device 400 in accordance with an embodiment of the present invention; and
[0035] [0035]FIG. 5 illustrates an exemplary partial cross sectional view of a device 500 in accordance with an embodiment of the present invention.
[0036] The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
[0037] In the following description, numerous details are set forth. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
[0038] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0039] [0039]FIG. 1A illustrates an exemplary partial cross-sectional view of a device 100 in accordance with an embodiment of the present invention. A motherboard 102 is attached to a semiconductor package 104 via solder balls 106 . As illustrated, a semiconductor device 108 is attached to the semiconductor package 104 via solder balls 110 . The semiconductor device 108 can be any semiconductor device including an integrated circuit, a processor, an application specific integrated chip (ASIC), and the like. It is envisioned that the semiconductor device 108 may be attached to the semiconductor package 104 utilizing a flip chip technique. A lifting mechanism 112 is attached to the semiconductor package 104 . The lifting mechanism 112 can utilize a spring 114 to increase the distance between the semiconductor package 104 and the motherboard 102 at a given point in time. It is envisioned that the lifting mechanism 112 can utilize a bimetallic spring 114 . The bimetallic spring 114 can be designed such that it would raise the semiconductor package 104 once the solder balls 106 are in their molten state. The spring can also be designed such that it would expand at a given rate depending on a given temperature and/or rate of temperature change applied to the spring.
[0040] [0040]FIG. 1B illustrates an exemplary partial cross sectional view of the device 100 of FIG. 1A after the solder balls 106 are elongated. The spring 114 lifts the semiconductor package 104 as shown in FIG. 1B by expansion. It is envisioned that the solder balls 106 may assume an hourglass form as illustrated in FIG. 1B. The heat required to put the solder balls 106 in their molten state, or other wise to provide reflow, can be provided by putting the device 100 in, for example, furnace or on a belt furnace which may in some embodiments employ different zones for heating. The temperature of each zone and the speed of the belt movement can be adjusted for an optimal case. Additionally, the temperature that the device 100 is exposed to may be appropriately chosen to burn off any fluxes which may be present for cleaning organics or otherwise for improving the soldering process.
[0041] Generally solder may have a propensity to stick to metallic surfaces. As such metal plated pads may be utilized on the contact points where the solder balls meet a device such as the semiconductor package 104 . These pads may also be plated with nickel and/or gold for better adhesion and to reduce corrosion. The propensity to stick to the metallic surfaces also helps in achieving the hourglass shape of the solder balls 106 illustrated in FIG. 1B. It is believed that an hourglass shape solder joint can be one of the most reliable structures during temperature cycling. Thus, such a structure may decrease the effects of thermal expansion substantially.
[0042] Moreover, it is envisioned that the expanded spring of 114 of FIG. 1B can be locked in place to provide sufficient distance between the semiconductor package 104 and the motherboard 102 . The locking may also assist the rigidity of the solder balls during the cooling stage by avoiding undesirable movements in certain directions.
[0043] [0043]FIG. 2A illustrates an exemplary partial cross sectional view of a device 200 in accordance with an embodiment of the present invention. As illustrated, the lifting mechanism 112 of FIG. 2A further includes a hard stop 116 . As the spring 114 increases the distance between the semiconductor package 104 and the motherboard 102 , the hard stop 116 limits the expansion of the spring 114 beyond a desirable point. This desirable point may be chosen, for example, based on the desired distance between the devices being attached. The stop point may also depend on the amount of solder being utilized and the appropriate curvature to be achieved for the hourglass shape.
[0044] [0044]FIG. 2B illustrates an exemplary partial cross sectional view of the device 200 of FIG. 2A after heat is applied to put the solder balls 106 in there reflow state. In FIG. 2B, the hard stop 116 limits the movement achieved by expansion of the spring 114 . It is further envisioned that the lifting mechanism 112 of FIG. 2B also provide for locking the lifting mechanism once a desired distance is reached. As shown in FIG. 2B, this can be achieved by utilizing a mechanical locking design, such as the illustrated hard stop 116 . The locking in place of the lifting mechanism 112 will prevent any spacing decrease between the semiconductor package 104 and the motherboard 102 after the spring 114 has performed its task during reflow.
[0045] It is envisioned that any lifting apparatus discussed herein may utilize numerous devices to achieve the lifting. Examples of other lifting apparatus include a spring (with any shape including cylindrical, spiral, conical, flat, u-shaped, and the like), a hydraulic mechanism, a screw, a gear, a wheel, a semi-solid (in an embodiment, epoxy like) material, which expands with temperature then solidifies to not only set the proper stand off but acts as an under-fill, any device that may be utilized to provide lifting, or any combination thereof. It is envisioned that a gear may be utilized that would engage teeth present on the objects being separated. Alternatively, a gear may be installed on the objects being separated with teeth on a bracket. With respect to wheels, they may be selected from material such that sufficient friction would be present for separating the objects. It is further envisioned that any of the lifting apparatus may be externally controlled, utilizing techniques including those discussed herein.
[0046] [0046]FIG. 3A illustrates an exemplary partial cross sectional view of a device 300 in accordance with an embodiment of the present invention. The device 300 utilizes a lifting mechanism 130 . The lifting mechanism 130 includes a hard stop 132 , a brake 138 , a control connection 136 , and a lifting device 134 . The lifting device 134 may be any type of a device capable of lifting including those discussed herein. The brake 138 may be a secondary brake or a brake under external control through, for example, the control connection 136 . As a secondary brake, the brake 138 will ensure that no movement is provided until a desired time and/or distance is reached. In some embodiments, the control connection 136 may be wiring for external temperature or time control. In certain embodiments, the brake 138 may be externally actuated and/or be temperature sensitive. Also, wireless communication (utilizing electromagnetic waves such as radio waves, infrared, visible light, ultraviolet, X rays, gamma rays, and the like) may be employed to provide communication and/or control of elements within the device 300 .
[0047] [0047]FIG. 3B illustrates an exemplary partial cross sectional view of the device 300 after the lifting mechanism 130 increases the distance between the motherboard 102 and the semiconductor package 104 . As illustrated in FIG. 3B, the lifting mechanism 130 has achieved a desired distance between the semiconductor package 104 and the motherboard 102 such that the solder balls 106 have achieved an hourglass shape. It is also envisioned that the brake 138 may be actuated under periodical and/or gradational control such that the distance between the package 104 and the motherboard 102 is controlled as a function of time and/or temperature. This can ensure that the solder balls 106 are given sufficient time to expand during the reflow, for example. It is also envisioned that finite element methods and/or fuzzy logic techniques can be utilized to ensure proper movement provided by any lifting apparatus. Any movement provided for herein can also be controlled and/or directed by a computing device such as a general purpose computer, a personal digital assistant (PDA), an embedded device, and the like.
[0048] In an embodiment, the computing device includes a Sun Microsystems computer utilizing a SPARC microprocessor available from several vendors (including Sun Microsystems of Palo Alto, Calif.). Those with ordinary skill in the art understand, however, that any type of computer system may be utilized to embody the present invention, including those made by Hewlett Packard of Palo Alto, Calif., and IBM-compatible personal computers utilizing Intel microprocessor, which are available from several vendors (including IBM of Armonk, N.Y.). Also, instead of a single processor, two or more processors (whether on a single chip or on separate chips) can be utilized to provide speedup in operations.
[0049] The computing device may also employ a network interface to provide communication capability with other computer systems on a same local network, on a different network connected via modems and the like to the present network, or to other computers across the Internet. In various embodiments, the network interface can be implemented in Ethernet, Fast Ethernet, wide-area network (WAN), leased line (such as T1, T3, optical carrier 3 (OC3), and the like), digital subscriber line (DSL and its varieties such as high bit-rate DSL (HDSL), integrated services digital network DSL (IDSL), and the like), time division multiplexing (TDM), asynchronous transfer mode (ATM), satellite, cable modem, and FireWire.
[0050] Moreover, the computing device may utilize operating systems such as Solaris, Windows (and its varieties such as NT, 2000, XP, ME, and the like), HP-UX, Unix, Berkeley software distribution (BSD) Unix, Linux, Apple Unix (AUX), and the like. Also, it is envisioned that in certain embodiments, the computing device is a general purpose computer capable of running any number of applications such as those available from companies including Oracle, Siebel, Unisys, Microsoft, and the like.
[0051] [0051]FIG. 4 illustrates an exemplary partial cross sectional view of a device 400 in accordance with an embodiment of the present invention. The device 400 includes a lifting mechanism 140 . The lifting mechanism 140 includes a lifting aligner 142 , a hard stop 132 , a lifter 134 , a control mechanism 136 , a stop 138 , and alignment pins 148 . It is envisioned that the lifting mechanism 140 may be any lifting apparatus discussed herein. The device 400 may also include the illustrated alignment holes 146 in the motherboard 132 . In some embodiments, the alignment may be provided by the semiconductor package and the lifting may be applied to the motherboard or any device being attached. As illustrated, the alignment pins 148 may be inserted in the alignment holes 146 of the motherboard 102 . The combination of the alignment brackets 142 , alignment holes 146 , and alignment pins 148 provide the device 400 with proper alignment between the semiconductor package 104 and the motherboard 102 . This is especially important as packages increase in size and the solder balls decrease in size. The device 400 may also include an optional expansion frame 144 which can be aligned with the alignment pins 148 and the alignment holes 146 . The expansion frame 144 shown can be mounted to the motherboard 102 through alignment pins 148 and/or alignment holes 146 . It is envisioned that utilizing alignment techniques discussed herein will stabilize the semiconductor package in the X, Y, and theta directions.
[0052] [0052]FIG. 5 illustrates an exemplary partial cross sectional view of a device 500 in accordance with an embodiment of the present invention. The device 500 includes a lifting mechanism 504 which can control the distance between the semiconductor package 104 and the semiconductor device 108 during reflow. The lifting mechanism 504 includes a spring 506 a stop 508 and a locking mechanism 510 . It is envisioned that the lifting mechanism 504 may be any lifting apparatus discussed herein. As illustrated in FIG. 5, the locking mechanism 510 may be engagingly attached to the spring 506 . The device 500 can provide lifting to the semiconductor device itself during the device attach reflow process. Thus, elongated solder joints are provided during reflow to reduce stress on the structures.
[0053] The foregoing description has been directed to specific embodiments. It will be apparent to those with ordinary skill in the art that modifications may be made to the described embodiments, with the attainment of all or some of the advantages. For example, the techniques discussed herein may be applied to any items being attached together. Also, the techniques discussed herein may be applied with other attachment material including glues (such as chemical, thermal, combinations thereof, and the like), welds, and the like. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the spirit and scope of the invention.
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Disclosed are novel methods and apparatus for efficiently providing dynamic solder attach, in part, to decrease the affects of thermal variations. In an embodiment, a spacer provides a gap between a semiconductor package and a device, an attachment material is disposed between the device and the semiconductor package, and an environmental control device provides an appropriate environment to activate the attachment material. In another embodiment, while the attachment material is substantially activated, the spacer increases the gap between the semiconductor package and the device to elongate the attachment material in a plane substantially perpendicular to the device and the semiconductor package. In yet a different embodiment, the elongated attachment material assumes a substantially hourglass shape.
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This is a division of application Ser. No. 08/518,459 filed Aug. 23, 1995.
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for assembling a disc-shaped recording medium, such as an optical disc or a magneto-optical disc. More particularly, it relates to a method and apparatus for assembling on a disc substrate a hub adapted for magnetically chucking the optical disc on a disc table of a recording/reproducing apparatus under a force of magnetic attraction.
The optical disc is a recording medium having information signals, such as speech signals or video signals, recorded with a high recording density, or capable of recording the information signals with a high recording density, recorded thereon. When loaded on the recording/reproducing apparatus, the optical disc is loaded on the disc table thereof so as to be run in rotation at a high rpm. When the optical disc is rotated at a high rpm, the information signals recorded on a recording area formed on its major surface are reproduced by a laser light radiated from an optical pickup unit. On the other hand, recording of desired information signals is carried out on the optical disc capable of recording the information signals by application by an external magnetic field generating unit of an external magnetic field modulated in accordance with the information signals to be recorded, whilst the laser light radiated from the optical pickup device is radiated on the signal recording area of the disc.
Meanwhile, for correctly radiating the laser light on a fine recording track of the signal recording area of the optical disc rotated at a high rpm, it is necessary for the optical disc to be reliably unified to the disc table of the recording/reproducing apparatus and to be correctly chucked relative to the disc table with the center of rotation of the disc coincident with the axis of the disc table. As a chuck mechanism for the optical disc, a so-called magnet chuck system is employed, in which the force of magnetic attraction of a magnet is utilized for highly accurately positioning and positively chucking the optical disc and which renders it possible to reduce the thickness of the recording/reproducing apparatus.
The magnet chuck system includes a magnet provided on the disc table and a hub formed by a magnetic plate, such as a magnetic metal plate, which is mounted in a center opening of the disc. Therefore, when loaded on the recording/reproducing apparatus, the hub is attracted by the magnet and thereby unified to the disc table so as to be rotated at a high rpm by a disc rotating driving mechanism.
An optical disc 100, to which is applied the above-described magnet chuck system, is made up of a disc substrate 101 and a hub 102, as shown in FIGS. 30 to 32. The disc substrate 101 is formed by a disc-shaped transparent substrate, such as a glass plate or a plate of a transparent synthetic resin, such as polycarbonate resin. The disc substrate 101 has a center aperture 103 and an information recording area on its major surface for surrounding the center opening 103 for recording information signals thereon. A hub 102 is mounted in the center aperture 103 of the disc substrate 101. The hub 102 for magnet clamping is fabricated by drawing a magnetic plate, such as a magnetic metal plate, and includes a bottomed tubular fitting portion 104 and an outer flange portion 105 extended on the outer periphery of the opening of the fitting portion 104. The fitting portion 104 has an outer diameter substantially equal to the diameter of the center aperture 103 of the disc substrate 101. The fitting portion 104 has in its center a spindle shaft receiving opening passed through by a spindle shaft of the disc rotating driving unit of the recording/reproducing apparatus, although such spindle shaft receiving opening is not shown.
With the above-described optical disc 100, the disc substrate 101 and the hub 102 are assembled together by a method which is now to be described. The disc substrate 101 is run in rotation, as shown in FIG. 30, as it is supported by supporting means, not shown. A UV curable adhesive 107 is dripped on the outer periphery of the center aperture 103 of the disc substrate 101 from an adhesive dispenser 106 provided on a major surface of the disc substrate. Since the disc substrate 101 is run in rotation, the adhesive 107 is applied homogeneously around the center aperture 103 by the disc substrate 101 being run in rotation.
The hub 102 is mounted on the disc substrate 101 by having the fitting portion 104 introduced into the center aperture 103 from the major surface thereof coated with the adhesive 107, as shown in FIG. 31. With the fitting portion 104 of the hub 102 fitted into the center aperture 103, the hub 102 is strongly thrust against the major surface of the disc substrate 101, so that the adhesive 107 is extended along the inner surface of the outer flange 105.
Subsequently, a UV beam radiated from a UV beam radiating device 108 is radiated on the disc substrate 101, as shown in FIG. 32. The adhesive 107, coated on the outer rim of the center aperture 103, is cured by the radiated UV beam for securely bonding the opposite surface portions of the disc substrate 101 and the outer flange 105 of the hub 102 for completing the optical disc 100.
Meanwhile, for correctly radiating the laser light on a recording track of the information signal recording area of the optical disc 100 rotated at a high rpm, the optical disc 100 is chucked by having its center of rotation correctly coincident with the axis of the disc table of the disc rotating driving unit, as described previously. Thus the optical disc 100 needs to be assembled in a centered state, that is in a state in which the center of rotation of the information signal recording area of the disc substrate 101 having information signals recorded thereon is correctly coincident with that of the hub 102 as a chucked member.
For centering the disc substrate 101 relative to the hub 102, there are known two methods, that is a first method in which the center of rotation of the disc substrate 101 is calculated by utilizing a picture processing device, and a second method in which the center of rotation of the disc substrate 101 is calculated by counting traverse signals.
That is, shown in FIG. 33, the basic concept of the first method is that an information signal recording area 110 of the disc substrate 101, that is an area carrying pits or grooves, differs in light reflectance from the area not carrying the pits or grooves, that is the inner most region or the outer most region of the disc substrate. The disc substrate 101 is set on an X-Y table, not shown, and the positions of at least three points on the same recording track of the information signal recording area 110, such as two points X1, X2 on the X-axis and two points Y1, Y2 on the Y-axis, as shown in FIG. 34, are read. The read-out points X1, X2, Y1 and Y2 are processed by a picture processing device, and the center position of these read-out points is calculated.
On the other hand, the hub 102 is arranged by being supported by supporting means, not shown, at a lower portion of the disc substrate 101. Thus the disc substrate 101 is centered relative to the hub 102 by controlled movement of the X-Y table controlled along the X-Y direction based upon a calculated output of the picture processing apparatus. The disc substrate 101 and the hub 102, centered relative to each other, are integrally assembled to each other by the method described previously.
The second method consists in rotationally driving the disc substrate 101, supported by a disc substrate driving device, not shown, and reading out information signals from an information signal recording area 110 provided on the disc substrate 101 by an optical pickup unit 111, as shown in FIG. 35. In such case, the optical pickup unit 111 is driven such that it is controlled in the focusing direction but not in the tracking direction, and counts traverse signals of the traversed recording tracks.
The amount of offset from the center of rotation of the disc substrate 101 is found from a product of the number of the traverse signals counted by the optical pickup device 111 and the track pitch. Thus the disc substrate 101 is centered with respect to the hub 102 by controlled movement of the X-Y table in the X-Y direction based upon the amount of correction corresponding to the amount of offset. The disc substrate 101 and the hub 102, centered relative to each other, are integrally assembled to each other by the method described previously.
With the above-described conventional centering method, in which the position of the center of rotation is directly found from the state of the information signal recording area 110 of the disc substrate 101, the hub 102 can be assembled on the disc substrate 101 by coinciding the center of the hub with the center of rotation of the information signal recording area 110, even if the center aperture 103 is offset from the center of the information signal recording area 110.
The above-described conventional centering methods suffer from the problem that the time required for searching the effective center of rotation of the disc substrate, more specifically, the time required for obtaining the picture information for the first method and the time required for counting the traverse signals of traversing the recording tracks by rotating the disc substrate for the second method, are protracted, while the time required for controlled movement of the X-Y table in the X-Y direction, is also protracted, thus lowering the productivity. In addition, the apparatus employed with the conventional centering method is extremely expensive.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an inexpensive apparatus for assembling an optical disc whereby a disc substrate and a hub can be assembled in a highly centered state in a short time.
It is another object of the present invention to provide a method for assembling an optical disc whereby a, disc substrate and a hub can be assembled in a highly centered state in a short time for reducing production cost of the optical disc.
The apparatus for assembling an optical disc according to the present invention includes a disc substrate having a center opening and an information recording area for concentrically recording information signals with the center opening as the center, and a hub assembled to the disc substrate by being fitted into the center opening from one major surface of the disc substrate so that the inner surface of the outer periphery thereof is unified to the outer periphery of the center opening. The apparatus includes an assembly guide member having a first guide portion movable in a direction perpendicular to one major surface of the disc substrate so as to be engaged in the center opening in the disc substrate, and a second guide portion formed integrally with the first guide member so that its center axis is aligned with the distal end of said first guide portion. The second guide portion is fitted in the spindle shaft opening in the hub. The assembly guide member has the first guide portion fitted in the center opening for positioning the disc substrate and the second guide portion engaged in this state in the spindle shaft opening for centering the disc substrate with respect to the hub.
A taper guide to be used at the time of engagement in the center opening is formed at the distal end of the first guide portion of the assembly guide member. Another taper guide to be used at the time of engagement in the spindle shaft opening is formed at the distal end of the second guide portion of the assembly guide member. The assembly guide member is run in rotation by driving means with the disc substrate assembled on the hub by the first guide portion being fitted in the center opening in the disc substrate and by the second guide portion being fitted in the spindle shaft opening in the hub.
The apparatus for assembling the disc-shaped recording medium includes a lower jig member having a guide opening for mounting the assembly guide member for reciprocating movement, and an upper jig member movable towards and away from the lower jig member. An end face of the lower jig member on which the guide opening is opened is arranged as a setting surface for a disc substrate. The upper jig member has a tubular disc substrate holding portion mating with the outer periphery of the center opening, and a hub thrusting portion mounted in the guide opening in the disc substrate holding portion for reciprocating movement and mating with the flange portion of the hub. The disc substrate and the hub are assembled on the assembly guide member by the first guide portion of the guide member protruded from the guide opening in the lower jig member being fitted in the center opening and the second guide portion being engaged in the spindle shaft opening. The disc substrate and the hub are assembled with respective centers in alignment with each other by the upper jig member being abutted against the jig member. The lower jig member has a suction opening, one end of which is connected to a vacuum suction device and the other end of which is opened on the peripheral region of the guide opening.
The apparatus for assembling the disc-shaped recording medium according to the present invention includes a lower jig member whose end face is constructed as a disc substrate setting surface configured for supporting the outer rim of the center opening of the disc substrate, and an upper jig member movable towards and away from the lower jig member and having a guide opening in which is mounted the assembly guide member for reciprocating movement. An end face of the upper jig member on which the guide opening is opened is configured as a hub thrusting portion for thrusting the flange portion.
The apparatus for assembling the disc-shaped recording medium according to the present invention includes a suction opening, one end of which is connected to a vacuum suction device and the other end of which is opened on the peripheral region of the guide opening. The lower jig member has a UV beam radiating unit in register with the outer periphery of the center opening in the disc substrate for opening on the disc substrate setting surface, and a UV beam radiating device in the UV beam radiating unit.
The method for assembling a disc-shaped recording medium including a disc substrate having a center opening and an information recording area for concentrically recording information signals with the center opening as the center, and a hub assembled to the disc substrate by being fitted into the center opening from one major surface of the disc substrate so that the inner surface of the outer periphery thereof is unified to the outer periphery of the center opening, employs an assembly guide member movable towards and away from the disc substrate in a direction at right angles to its major surface and having a first guide portion fitted into the center opening in the disc substrate and a second guide portion integrally and coaxially formed at the distal end of the first guide portion and fitted into a spindle shaft opening in the hub. The method includes a first step of assembling the disc substrate in position by inserting the first guide portion of the assembly guide member in the center opening and assembling the hub by fitting the second guide portion in the spindle shaft opening, a second step of coating an adhesive to the outer rim of the center opening in the disc substrate, and a third step of receding the assembly guide member for fitting the hub in the center opening in the disc substrate.
The method for assembling a disc-shaped recording medium employs a lower jig member having a guide opening for mounting the assembly guide member for reciprocating movement, and an upper jig member movable towards and away from the lower jig member. An end face of the lower jig member on which the guide opening is opened is arranged as a setting surface for a disc substrate. The upper jig member has a tubular disc substrate holding portion mating with the outer periphery of the center opening, and a hub thrusting portion mounted in the guide opening in the disc substrate holding portion and mating with the flange portion of the hub. The method includes a first step of assembling the disc substrate in position by inserting the first guide portion of the assembly guide member in the center opening and assembling the hub by fitting the second guide portion in the spindle shaft opening, a second step of coating an adhesive to the outer rim of the center opening in the disc substrate, a third step of lowering the assembly guide member along the guide opening in the lower jig member for abutting the disc substrate assembled on the assembly guide member against the disc setting surface of the lower jig member and lowering a disc substrate holding portion of the upper jig member towards said lower jig member in this state for clamping the disc substrate between the holding portion and the disc setting surface, a fourth step of lowering the assembly guide member further along the guide opening in the lower jig member for fitting the hub in the center opening in the disc substrate and lowering the hub thrusting portion of the upper jig member towards the lower jig member for thrusting the flange portion of the hub to the outer rim of the center opening of the disc substrate by the hub thrusting portion, and a fifth step of raising the upper jig member relative to the upper jig member for taking out the assembled disc-shaped recording medium.
The method for assembling a disc-shaped recording medium employs a lower jig member whose upper end face is constructed as a disc substrate setting surface configured for supporting the outer rim of the center opening of said disc substrate, and an upper jig member movable towards and away from the lower jig member and having a guide opening in which is mounted the assembly guide member for reciprocating movement. A lower end face of the upper jig member on which the guide opening is opened is configured as a hub thrusting portion for thrusting the flange portion. The method includes a first step of setting a disc substrate on the disc substrate setting surface of the lower jig member, a second step of lowering the assembly guide member along the guide opening in the upper jig member for fitting the first guide portion in the center opening in the disc substrate for positioning the assembly guide member on the disc substrate setting surface, a third step of coating an adhesive to the outer rim of the center opening in the disc substrate, a fourth step of fitting the second guide portion in the spindle shaft opening with the assembly guide member being raised along the guide opening in the upper jig member for assembling the hub to the assembly guide member, a fifth step of lowering the assembly guide member along the guide opening in the upper jig member for fitting the hub in the center opening in the disc substrate while lowering the hub thrusting portion towards the upper jig member for thrusting the flange portion of the hub by the hub thrusting portion against the outer rim of the center opening of the disc substrate, and a sixth step of raising the upper jig member relative to the lower jig member for taking out the assembled disc-shaped recording medium.
The method for assembling a disc-shaped recording medium in which the adhesive applied to the outer rim of the center opening of the disc substrate is a UV curable adhesive further includes the step of radiating a UV light beam for securing the disc substrate and the hub to each other with the flange portion of the hub being thrust against the outer peripheral surface of the center opening in the disc substrate by the hub thrusting portion of the upper jig member.
With the above-described apparatus for assembling the disc-shaped recording medium according to the present invention, the first guide portion of the guide member is fitted in the center opening in the disc substrate, while the second guide portion of the assembly guide member is fitted in the spindle shaft opening of the hub, so that the disc substrate and the hub are assembled together via this assembly guide member for assembling the correctly centered disc-shaped recording medium. The taper guides formed in the first and second guide portions of the assembly guide member operate as inserting guides and facilitate fitting of the first guide portion in the center opening in the disc substrate or the fitting of the second guide portion in the center opening in the disc substrate.
The disc substrate and the hub are assembled together in a relatively positioned state with the assembly guide member. The disc substrate is set and held on the disc substrate setting surface of the lower jig member via the assembly guide member. The upper jig member is abutted against the lower jig member for thrusting the hub thrusting portion against the outer flange portion of the hub for assembling the hub along the assembly guide member in a centered position in the center opening of the disc substrate. The suction opening in the disc substrate setting surface of the lower jig member operates for securely holding the disc substrate positioned by being engaged by the first guide portion of the assembly guide member.
The disc substrate set n the disc substrate setting surface of the lower jig member is positioned by the assembly guide member provided on the upper jig member being lowered towards the lower jig member so that the first guide portion is engaged in the center opening. The hub is assembled on the assembly guide member in the raised position by the second guide portion being fitted in the spindle shaft opening. The upper jig member is abutted against the lower jig member so that the hub thrusting portion thrusts the outer peripheral flange portion of the hub for assembling the hub in a centered state on the disc substrate setting surface along the assembly guide member. The suction opening opened in the second guide portion of the assembly guide member sucks and holds the hub which is assembled with the second guide portion fitted in the spindle shaft opening.
With the method for assembling the disc-shaped recording medium according to the present invention, the first guide portion of the guide member is fitted in the center opening in the disc substrate, while the second guide portion of the assembly guide member is fitted in the spindle shaft opening of the hub, so that the disc substrate and the hub are positioned relative to each other. Thus the disc substrate and the hub are assembled via the assembly guide member whereby the disc-shaped recording medium is assembled in the correctly centered state.
In addition, the assembly guide member, in which the disc substrate and the hub have been assembled together in the relatively positioned state, is lowered along the lower jig member so that the disc substrate is set and held on the disc substrate setting surface of the lower jig-member. The upper jig member is abutted against the lower jig member so that the hub having its outer flange portion thrust by the hub thrusting portion is assembled on the disc substrate in the centered state in the center opening along the assembly guide member. The suction opening formed in the disc substrate setting surface of the lower jig member positively holds the disc substrate in which the fitting state of the first guide portion in the center opening has been canceled by the lowering of the assembly guide member.
According to the present invention, the disc substrate and the hub may be assembled together in the correctly centered state via the assembly guide member by a simplified operation with minimum cost thus assuring reduction in investment cost and improved productivity. In addition, the centering between the disc substrate and the hub, which usually required a time-consuming laborious operation, may be achieved easily by employing the assembly guide member, so that the assembly process may be simplified thus lowering the cost of the disc-shaped recording medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a disc cartridge.
FIG. 2 is a perspective view of the disc cartridge, looking from a top surface thereof.
FIG. 3 is a perspective view of the disc cartridge, looking from its bottom surface.
FIG. 4 is a front view showing essential portions of an assembly guide member provided in an assembling apparatus for a disc-shaped recording medium according to the present invention.
FIG. 5 illustrates the step of loading a disc substrate on the assembly guide member.
FIG. 6 illustrates the step of coating an adhesive on the disc substrate loaded on the assembly guide member.
FIG. 7 illustrates the step of loading a hub on the assembly guide member.
FIG. 8 illustrates the step of securing the hub on the assembly guide member.
FIG. 9 illustrates the step of detaching the disc substrate having the hub assembled thereon from the assembly guide member.
FIG. 10 is a longitudinal cross-sectional view showing the setting state of the assembling apparatus.
FIG. 11 illustrates the step of loading the disc substrate on the assembly guide member in the assembling apparatus shown in FIG. 10.
FIG. 12 illustrates the step of loading the hub on the assembly guide member in the assembling apparatus shown in FIG. 10.
FIG. 13 illustrates the step of sucking the disc substrate loaded on the assembly guide member on a disc substrate setting surface of a lower jig member in the assembling apparatus shown in FIG. 10.
FIG. 14 illustrates the step of securing the hub to the disc substrate in the assembling apparatus shown in FIG. 10.
FIG. 15 illustrates the step of pressing the hub onto the disc substrate by a hub pressing member of an upper jig member in the assembling apparatus shown in FIG. 10.
FIG. 16 illustrates the step of radiating UV rays to the disc substrate from a UV radiating unit built in the lower jig member in the assembling apparatus shown in FIG. 10.
FIG. 17 illustrates the step of releasing the hub from pressure by the lower jig member in the assembling apparatus shown in FIG. 10.
FIG. 18 illustrates the step of releasing the disc substrate from pressure exerted by the disc substrate pressing member of the upper jig member in the assembling apparatus shown in FIG. 10.
FIG. 19 illustrates the step of taking out the optical disc comprised of the disc substrate and the hub assembled together in the assembling apparatus shown in FIG. 10.
FIG. 20 is a longitudinal cross-sectional view showing the setting state of essential portions of an assembling apparatus for a disc-shaped recording medium according to a second embodiment of the present invention.
FIG. 21 illustrates the step of loading the disc substrate in a provisional holding state on a disc substrate setting surface of the lower jig member.
FIG. 22 illustrates the step of centering the disc substrate by an assembly guide member while the disc substrate is set on the disc substrate setting surface of the lower jig member in the assembling apparatus shown in FIG. 20.
FIG. 23 illustrates the step of primary releasing of the disc substrate by upward movement of an upper jig member while keeping the disc substrate positioned on the disc setting surface of the lower jig member in the assembling apparatus shown in FIG. 20.
FIG. 24 illustrates the step of loading the hub on the assembly guide member in the assembling apparatus shown in FIG. 20.
FIG. 25 illustrates the step of securing the hub to the disc substrate by the lowering of the upper jig member in the assembling apparatus shown in FIG. 20.
FIG. 26 illustrates the step of pressing the hub to the disc substrate by a hub pressing member of the upper jig member in the assembling apparatus shown in FIG. 20.
FIG. 27 illustrates the step of radiating a UV beam to the disc from a UV beam radiating unit mounted in the lower jig member in the assembling apparatus shown in FIG. 20.
FIG. 28 illustrates the step of terminating the radiation of the UV beam from the UV beam radiating device to the disc substrate in the assembling apparatus shown in FIG. 20.
FIG. 29 illustrates the step of taking out the optical disc comprised of the disc substrate and the hub assembled together in the assembling apparatus shown in FIG. 20.
FIG. 30 illustrates the step of coating an adhesive in a conventional production process of a disk-shaped recording medium.
FIG. 31 illustrates the step of mounting a hub in the conventional production process of a disk-shaped recording medium.
FIG. 32 illustrates the step of radiating a UV beam to the conventional optical disk.
FIG. 33 is a perspective view showing the construction of a convention optical disk.
FIG. 34 is a plan view showing the conventional optical disk.
FIG. 35 illustrates the step of rotationally driving the disk and reading out information signals by an optical pick-up unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, illustrative embodiments of the present invention will be explained in detail.
As shown in FIGS. 1-3, a disc cartridge 10 is comprised of a cartridge casing (cartridge main body) made up of an upper cartridge half 11 and a lower cartridge half 12, each formed of a synthetic resin material, and an optical disc 1 rotatably housed within the cartridge casing. The upper cartridge half 11 and the lower cartridge half 12 are formed with a peripheral wall members 13, 14 which, when the upper cartridge half 11 and the lower cartridge half 12 are assembled together, the wall members 13, 14 are abutted against each other to form an outer wall of the cartridge casing.
The opposing inner surfaces of the upper and lower cartridge halves 11, 12 are formed with disc housing forming wall members 15, 16 formed as arcuate peripheral wall members disposed on a circumference of a circle circumscribing the wall members 13, 14. When the upper and lower cartridge halves 11, 12 are assembled together, the disc housing forming wall members 14, 15 are abutted against each other to form a disc housing. In addition, the opposing inner surfaces of the upper and lower cartridge halves 11, 12 are formed with plural protrusions, with the protrusions on the lower half 12 being shown at 18.
The upper and lower cartridge halves 11, 12 are assembled together by abutting the peripheral wall members 13, 14 and the disc housing forming wall members 15, 16 and by fitting the protrusions together and bonding them together by ultrasonic welding to constitute the cartridge casing.
The lower half 12 is formed at a mid portion thereof with a circular opening 20. When the disc cartridge 10 is loaded on a recording/reproducing apparatus, a disc table of the recording/reproducing apparatus driving the optical disc 1 housed within the cartridge casing is intruded into the opening 20. Specifically, the opening 20 exposes to outside a hub 4 formed of a magnetic material for magnet clamping which is mounted for closing a center aperture 3 of the optical disc 1 contained in the cartridge casing. An annular holding wall member 21 is provided at a mid portion of the upper cartridge half 11 in register with the opening 20. The holding wall 21 is abutted against the inner periphery of the optical disc 1 to permit smooth rotation of the optical disc 1 within the cartridge casing.
The upper and lower surfaces of the cartridge casing, that is. the upper and lower cartridge halves 11, 12, are formed with recording/reproducing apertures 22, 23, for exposing at least portions of the signal recording area of the optical disc 1 rotatably housed within the disc housing across the inner and outer rims of the disc. These recording/reproducing apertures 22, 23 are rectangular-shaped and extended from the positions close to the opening 20 and the holding wall section 21 to the front side of the cartridge casing at a mid portion in the transverse direction of the cartridge casing, as shown in FIG. 1.
The upper and lower cartridge halves 11, 12 are respectively formed with guide recesses 25, 26 on their front sides defining a guide groove 24 into which is intruded a shutter opening member of the recording/reproducing apparatus designed for shifting a shutter member 28 now to be explained. That is, with the upper and lower cartridge halves 11, 12 assembled together, the guide recesses 25, 26 make up a shutter opening member guide groove on the front surface of the cartridge casing.
For prohibiting dust and dirt from being intruded via the apertures 22, 23 into the disc housing so as to be deposited on the optical disc 1 housed in the cartridge casing (cartridge main body), a shutter member 28 is assembled on the cartridge main body for closing the apertures 22, 23. The shutter member 28 is fabricated by press-working a thin metal plate into substantially a U-shape and is comprised of a first shutter portion 29 and a second shutter portion 30, dimensioned to close the apertures 22, 23, respectively, and a connecting portion 31 interconnecting the proximal ends of the first and second shutters 29, 30. The second shutter portion 30 is dimensioned to close the opening 20 from the front side of the lower half 12 and closes the aperture 23 and the opening 20.
The shutter member 28 has a shutter guide member 32 on the inner surface of the connection portion 31. The shutter guide member 32 is formed substantially in the form of a rod of a synthetic resin material having a length substantially twice the width of the shutter member 28. An engagement portion 33 is formed integrally with one end of the shutter guide member 32. The shutter guide member 32 has its side opposite to the engagement portion 33 assembled to the inner surface of the connecting portion 31 of the shutter member 28 for constituting a shutter assembly. With the shutter assembly assembled on the cartridge main body, the shutter guide member 32 delimits a gap between the cartridge main body and the engagement portion 33. The gap is configured to be engaged by a shutter driving member of the recording/reproducing apparatus.
The shutter assembly is assembled on the cartridge main body by the first and second shutter portions 29, 30 of the shutter member 28 clamping the cartridge main body and by the shutter guide member 32 being engaged in the guide groove 24. When the disc cartridge 10 is loaded on the recording/reproducing apparatus, the shutter assembly is moved by the shutter driving member of the recording/reproducing apparatus from a first position of closing the apertures 22, 23 to a second position of opening the apertures 22, 23 by the first and second shutter portions 29, 30.
The shutter assembly is normally held by the elastic force of a spring 34 in the position of closing the apertures 22, 23 by the first and second shutter portions 29, 30 of the shutter member 28, respectively. The spring 34 is constituted by a coil base portion both ends of which are extended as shown. The spring 34 is assembled by having its coil base portion inserted into a front side one 35 of the plural protrusions 18 provided on the lower half 12. The spring 34, thus assembled on the lower cartridge half 12, has its both ends slightly compressed in order to store an elastic force. In this state, the spring 34 has its one end engaged with the shutter guide member 32 and has its other end engaged with the opposite side protrusion 18.
In a region of the upper and lower cartridge halves 11, 12 constituting the cartridge main body extending from the periphery of the apertures 22, 23 to one lateral sides of the halves 11, 12, along which the first and second shutter portions 29, 30 of the shutter member 28 are moved, and reaching the front side of the cartridge main body, there are formed recesses 36, 37 of substantially the same depth as the plate thickness of each of the first and second shutter portions 29, 30. These recesses 36, 37 render it possible to assemble the shutter member 28 so that its first and second shutter portions 29, 30 are mounted with the surfaces thereof flush with the surface of the cartridge main body. Thus the disc cartridge 10 is prevented from being increased in thickness due to assembling the shutter member 28 to the cartridge main body.
The disc cartridge 10 is provided with a mistaken recording inhibiting mechanism for inhibiting mistaken erasure of information signals recorded on the optical disc 1. This mistaken recording inhibiting mechanism is comprised of a mistaken recording inhibiting member 39 provided at a rear side corner of the lower cartridge half 12 associated with the front side corner thereof provided with the spring 34, and a mistaken recording detection opening 40 formed in the upper cartridge half 11.
The mistaken recording inhibiting member 39 is a substantially E-shaped member of a synthetic resin excellent in sliding properties and in resilient displacement properties which is comprised of a base portion, a pair of resilient click pieces and an operating piece extending parallel to one another. The base portion is substantially of an elliptical cross-section and is dimensioned to close the mistaken recording detection opening 40 as later explained. The lower half 12 is formed in its major surface with an elliptically-shaped guide opening 41 in register with the base portion of the mistaken recording inhibiting member 39. The upper cartridge half 11 is formed with click protrusions, not shown, resiliently engaged by the resilient clicks. The upper and lower cartridge halves 11, 12 are formed with a cut-out by partially removing portions of the peripheral wall members 13 and 14 in register with the operating piece of the mistaken recording inhibiting member 39.
The mistaken recording detection opening 40 is formed in the upper cartridge half 11 in register with one end of the guide opening 41 formed in the lower half 12. By the operating piece facing the opening 42, the mistaken recording inhibiting member 39 is switched between the first portion closing the mistaken recording detection opening 40 by its base portion and the second position of opening the mistaken recording detection opening 40. When set to the first position of closing the mistaken recording detection opening 40 by the base portion, the mistaken recording inhibiting member 39 prohibits a mistaken recording inhibiting mechanism of the recording/reproducing apparatus from being intruded into the mistaken recording detection opening 40 for enabling information signals to be recorded on the optical disc 1 housed within the cartridge main body.
When switched by the operating piece along the guide opening 41 so as to be set by the base portion to the second position of opening the mistaken recording detection opening 40, the mistaken recording inhibiting member 39 permits the mistaken recording detection mechanism of the recording/reproducing apparatus to be intruded into the mistaken recording detection opening 40 in order to disable recording of information signals on the optical disc 1 housed within the cartridge main body.
The optical disc 1, rotatably housed within the above-described disc cartridge 1, is made up of a disc substrate 2, and a hub 4 for the magnet clamp which is assembled into the center opening 3 of the disc substrate 2. The disc substrate 2 is constituted by stacking and bonding a pair of transparent disc-shaped disc substrate portions formed of glass or transparent synthetic resin, such as polycarbonate. The first disc substrate portion has an information signal recording area of pits or grooves on its major surface bonded to the second disc substrate portion which is formed spirally or concentrically and on which information signals are pre-recorded or are to be recorded. The second disc substrate portion is precisely bonded to the major surface of the first disc substrate portion, such as by a hot melt, for sheathing the information signal recording area, and has its major surface operating as a read-out surface for information signals. The disc substrate 2 may also be of a unitary structure.
The hub 4 is a member formed by press-working or drawing a magnetic plate, such as a magnetic metal plate, and is made up of a bottomed tubular fitting portion 5 of an outer diameter substantially equal to the inner diameter of the center opening 3 of the disc substrate 2 and an outer peripheral flange portion 6 formed for extending around the entire periphery of the opening in the fitting portion 5. The fitting portion 5 has a height slightly larger than the thickness of the disc substrate 2 and has a spindle shaft opening 7 at its center for accommodating a spindle shaft of the recording/reproducing apparatus, not shown. The outer flange portion 6 has an outer diameter slightly smaller than the inner most rim of the information recording area formed in the disc substrate 2.
The disc substrate 2 and the hub 3 are assembled together by an assembly guide member 50 shown in FIG. 4. The assembly guide member 50 is made up of a first guide portion 51 as a basic shaft portion and a second guide portion 52 formed as one with the foremost part of the first guide portion 51. The first guide portion 51 has an outer size slightly larger than the diameter of the center opening 3 of the disc substrate 2 and has a taper guide 52 at its foremost part which is gradually decreased in outer diameter. Of course, the outer size of the front end face of the first guide portion 51 carrying the taper guide 52 is larger than the outer diameter of the second guide 53.
The second guide portion 53 has its outer diameter slightly larger than the diameter of the spindle shaft opening 7 of the hub 4. The second guide portion 53 is formed at the foremost part of the first guide portion 51 co-axially therewith.
The above-described assembly guide member 50 is run into rotation by being supported by a driving unit, not shown, while being moved vertically in FIG. 4 for assembling the disc substrate 2 and the hub 4 together. FIGS. 5 to 9 illustrate basic assembly steps for the optical disc 1 with the aid of the assembly guide member 50. The disc substrate 2 is assembled to the assembly guide member 50 by the first guide portion 51 being fitted in the center opening 3, as shown in FIG. 5. The taper guide 52 facilitates fitting of the first guide portion 51 in the center opening 3, and operates for correcting the tolerance in outer diameter of the center opening 3 of the disc substrate 2 for assembling the disc substrate 2 with respect to the assembly guide member 50.
That is, with the disc substrate 2, manufactured extremely precisely, it is difficult to maintain its precision due to fluctuations in the molding condition or in the lot of the starting resin material, such that the diameter of the center opening 3 usually has some tolerance. Of course, the center opening 3 is molded to high circularity. When assembling the disc substrate 2 having some tolerance in the diameter of the center opening 3, the taper guide 52 operates for coinciding the center of the disc substrate 2 with that of the first guide portion 51.
The disc substrate 2, thus assembled in position on the assembly guide member 50 by the above-described operation, is held by a holding device, not shown. With the disc substrate 2 assembled on the assembly guide member 50, a UV curable adhesive 55 is applied to the outer periphery of the center opening 3, as shown in FIG. 6. The UV curable adhesive is applied from an adhesive supplying unit, not shown, provided above the major surface of the disc substrate 2, to a region between the center opening 3 and the information signal recording area. Since the disc substrate 2 is rotated via the assembly guide member 50, the adhesive is applied uniformly on the outer rim of the center opening 3.
The hub 4 is mounted on the assembly guide member 50 by the second guide portion 53 being fitted into the spindle shaft opening 7, as shown in FIG.13. A taper guide 54 is provided in the second guide portion 53. Similarly to the taper guide 52 provided in the guide portion 51, the taper guide 54 facilitates fitting of the second guide portion 53 with the spindle shaft opening 7, while correcting the tolerance in the diameter of the spindle shaft opening 7 for assembling the hub 4 to the assembly guide member 50. Since the assembly guide member is made up of the first and second guide portions 51, 53 integrally and in axial alignment with each other, as described previously, the disc substrate 2 and the hub 4 are assembled to the guide member 50 with the center of the center opening 3 in register with the center of the spindle shaft opening 7, that is, in the centered state relative to each other.
The assembly guide member 50 is moved downward relative to the disc substrate 2 held by the holding device, so that the first guide portion 51 clears the center opening 3, as shown in FIG. 8. The hub 4, assembled to the assembly guide member 50 by the second guide portion 53 in the spindle shaft opening 7, has the fitting portion 5 fitted in the center opening 3 by such downward movement of the assembly guide member 50, while the outer flange portion 6 is unified to the outer rim of the center opening 3, thus assembling the hub relative to the disc substrate 2.
The hub 4 is assembled to the disc substrate 2, with the assembly guide member 50 as guide, in an extremely precise holding state, while the assembled state is held by a holding device, not shown. A UV beam radiating device, not shown, radiates a UV beam to the outer rim portion of the center opening 3 of the disc substrate 2 to which the hub 4 has been assembled as described above. The UV curable adhesive 55, coated on the outer rim of the center opening 3, is cured by the radiation of the UV beam for securing the outer flange portion 6 of the hub 4 to the major surface of the disc substrate 2 for completing the optical disc 1.
The assembly guide member 50 is further moved downward, as shown in FIG. 9, so that the second guide portion 53 is detached from the spindle shaft opening 7 of the hub 4 to permit extraction of the optical disc 1 comprised of the disc substrate 2 and the hub 4 centered and assembled together.
FIGS. 10 to 19 illustrate the assembly process of the optical disc 1 by an assembling device 8 for carrying out the basic assembling process as described above. The assembly device 8 is comprised of a lower jig 60 holding the assembly guide member 50 and an upper jig 70 adapted for being moved towards and away from the lower jig 60, as shown in FIG. 10. The lower jig 60 is made up of a tubular lower jig member 61, as a main part, and the aforementioned assembly guide member 50. The lower jig member 61 has a guide opening 62 extending in the height-wise direction and along which the assembly guide member 50 is moved axially. The lower jig member 61 has its upper end face as a disc substrate setting surface 63 and includes plural suction openings 64 opened on the disc substrate setting surface 63 and a UV beam radiating unit 65 having a UV beam radiating device 67.
The disc substrate setting surface 63, constituted as a horizontal surface of higher horizontality, has an outer size large enough to support a region between the center opening 3 of the disc substrate 2 and the information signal recording area, and carries the center guide opening 62. A plurality of suction openings 64 are opened on the disc substrate setting surface 63 for encircling the guide opening 62. These suction openings 64 are connected at the lower ends thereof to a vacuum suction system, not shown. Thus, on actuation of the vacuum suction device, the disc substrate setting surface 63 of the lower jig 60 operates as a suction surface.
On the other hand, the UV beam radiating unit 65 is comprised of a space provided in the lower jig member 61 so as to be opened in the lateral surface of the lower jig member 61 and so as to be opened at its upper portion on the disc substrate setting surface 63 for operating as UV beam radiating opening 66. The UV beam radiating device 67 is mounted in the UV beam radiating unit 65 with the radiating surface thereof directed to the disc substrate setting surface 63 from the lateral surface of the lower jig member 61.
The upper jig 70 is made up of a tubular first upper jig member 71 having a vertically extending guide opening 72 and a second upper jig member 74 assembled for vertical movement in the guide opening 72 in the first jig member 71. The tubular flange portion of the first upper jig member 71 carrying the guide opening 72 has an outer diameter slightly larger than the upper end of the lower jig member 61 constituting the disc substrate setting surface 63. The first upper jig member 71 operates as a disc substrate thrusting portion 73, as will be explained subsequently. The first upper jig member 71 is driven by driving means, not shown, in a vertical direction towards and away from the lower jig member 61.
The second upper jig member 74 is constituted by a piston rod member having an outside diameter slightly larger than the diameter of the guide opening 62 of the lower jig member 61, and is driven vertically in the guide opening 72 in the first upper jig member 71 by a driving mechanism, not shown. The lower end of the second upper jig member 71 operates as a hub thrusting portion 75, as will be explained subsequently. The second upper jig member 74 has an axial clearance opening 76 opened on the hub thrusting portion 75. The clearance opening 76 is formed in the second upper jig member 74 with a diameter and a length sufficiently larger than the axial size of the second guide portion 53 of the assembly guide member 50.
An adhesive supplying unit, not shown, is provided on the upper lateral side of the lower jig 60. When the disc substrate is assembled on the assembly guide member 50 built into the lower jig member 61 for vertical movement, as will be explained subsequently, the adhesive supplying device is intruded into a space between the lower jig 60 and the upper jig 70 for dripping the UV curable adhesive to the outer rim of the center opening 3 of the disc substrate 2. At this time, the assembly guide member 50 is run in rotation by a driving mechanism, not shown, for rotating the disc substrate 2 in unison therewith for allowing the dripped UV curable resin to be uniformly coated on the outer rim of the center opening 3. After the end of the coating step of the UV curable adhesive to the disc substrate 2, the adhesive supplying device is retracted to a lateral area outside the range of movement of the upper jig 70.
With the above-described assembly device 8, the upper jig 70 is raised with respect to the lower jig 60. As for the assembly guide member 50, the upper end of the first guide portion 51, is protruded and exposed from the upper end portion of the first guide portion 51. That is, the taper guide 52 is protruded and exposed from the disc substrate setting surface 63. The disc substrate 2 is assembled to the assembly guide member 50 with the first guide member 52 introduced into the center opening 3. The UV curable resin is coated in a uniform state on the outer rim of the center opening 3 by the above-described adhesive supplying device, as shown in FIG. 6. The hub 4 is mounted on the assembly guide member 50 by having the first guide portion 53 being fitted in the spindle shaft opening 7, as shown in FIG. 7. The disc substrate 2 and the hub 4 are assembled on the assembly guide member 50 with the respective center positions coincident with each other.
With the disc substrate 2 and the hub 4 mounted on the guide member 50, a driving system, not shown, is actuated for lowering the first upper jig member 71 and the second upper jig member 74 towards the lower jig 60. Prior to the downward movement of the upper jig 70, a vacuum suction system, not shown, is driven for operating a force of suction on the disc substrate setting surface 63 of the lower jig member 61, and for lowering the assembly guide member 50 by a driving system, not shown.
This releases the fitting state of the first guide portion 51 of the assembly guide member 50 in the center opening 3 while sucking the disc substrate 2 onto the disc substrate setting surface 63. As for the first upper jig member 71, the disc substrate thrusting portion 73 thrusts the disc substrate 2 against the disc substrate setting surface 63 along the assembly guide member 60, as shown in FIG. 15. The disc substrate 2 is clamped by the disc substrate thrusting portion 73 and the disc substrate setting surface 73 of the lower jig member 61 so as to be held in position on the disc substrate setting surface 63 under the force of suction exerted via the suction opening 64. When the upper jig 70 has been lowered, the assembly guide member 50 is positioned in the clearance opening 76.
The assembly guide member 50 is then lowered by a driving mechanism, not shown. This releases the fitting state of the frost guide portion 51 of the assembly guide member 50 in the center opening 3. However, since the disc substrate 2 is held in position on the disc substrate setting surface 63 under the operation of the disc substrate thrusting portion 73 of the first upper jig member 71 and the suction opening 64, the disc substrate 2 is prohibited from being moved in idleness. The assembly guide member 50 is further lowered until the hub 4 built in the assembly guide member 50 is fitted into the center opening 3 of the disc substrate 2, as shown in FIG. 14.
With the hub 4 assembled to the disc substrate 2, the second upper jig member 74 of the upper jig 70 is lowered along the guide opening 72 in the first upper jig member 71 by driving means, not shown, until the hub thrusting portion 75 thrusts the outer flange portion 6 of the hub 4 towards the disc substrate 2, as shown in FIG. 15. The disc substrate 2, carrying the hub 4, is irradiated with a UV light beam L from the UV light beam radiating device 67 provided in the UV light beam radiating unit 65 of the lower jig member 61. The UV light beam L is radiated on the outer periphery of the center opening 3 of the disc substrate 2 via the UV light beam radiating port 66 formed on the disc substrate setting surface 63, as shown in FIG. 16. The UV curable adhesive, coated on the outer periphery of the center opening 3, is cured by radiation of the UV beams for securing the outer peripheral flange portion 6 of the hub 4 to the major surface of the disc substrate 2 for completing the optical disc 1.
On completion of the assembling of the hub 4 to the disc substrate 2 by the above process, driving means, not shown, of the assembling device 8 is actuated for lifting the upper jig member 74 of the upper jig 70, as shown in FIG. 17. In this state, the optical disc 1 is pressed by the disc substrate thrusting portion 73 of the first upper jig member 71 against the disc substrate setting surface 63 of the lower jig member 61.
The upper jig 70 is separated away from the lower jig 60 by the first upper jig member 71 being uplifted by driving means, not shown, as shown in FIG. 18. The optical disc 1, now carrying the disc substrate 2 and the hub 4, is released from the state of being sucked on to the disc substrate setting surface 63 of the lower jig 60, since the vacuum suction device is halted. Thus the assembly guide member 50 is uplifted along the guide opening 62 of the lower jig member 61, with the upper jig being now floated above the lower jig 60, as shown in FIG. 19. The optical disc 1 can now be taken out of the assembly device 8.
FIGS. 20 to 29 illustrate the assembly steps by an assembly device 9 of the second embodiment for realization of the above-described basis assembly process. The assembly device 9 is made up of an assembly device, a lower jig 60 and an upper jig 80 as shown in FIG. 20. The assembly guide member 50 is vertically movable towards the upper jig 80. With the assembly device 8 of the first embodiment, the lower jig member 61 constituting the lower jig 60 operates as a guide opening to permit vertical movement of the assembly guide member 50. In the assembly device 9 of the present embodiment, the guide opening 62 operates as a clearance opening for the assembly guide member 50.
Although the lower jig member 61 is of the same constriction as the lower jig member of the previously described first embodiment, it may also be constructed uniquely. In such case, the lower jig member 61 naturally needs to be provided at least with a clearance opening 62 for the assembly guide member 50, disc substrate setting surface 3, holding mechanism for the disc substrate 2 and with the a UV light beam radiating unit 65 for the UV light beam radiating device 67.
The assembly guide member 50 is moved vertically in a guide opening 82 by driving means, not shown, in an upper jig member 81 which will be explained subsequently. The assembly guide member 50 holds the hub 4 by fitting the second guide portion 53 in the spindle shaft opening 7 in the assembly process as later explained, and has an axially extending suction opening 56 for prohibiting detachment of the hub 4. The suction opening 56 has its one end opened in the distal end of the first guide portion 51 for surrounding the second guide portion 53 and has its other end connected to a vacuum suction system, not shown. Thus the end face of the first guide portion 51 operates as a suction surface for the hub 4. Meanwhile, it suffices if the suction opening 56 is so designed as to develop a force of suction sufficient to transiently hold the hub 4 relatively light in weight to the assembly guide member 50. The number of the suction holes 56 may be set arbitrarily.
The upper jig 80 is made up of a tubular upper jig member 81 and an assembly guide member 50 movably mounted in a vertically extending guide opening 82 formed in the upper jig member 81. The upper jig member 81 is moved by driving means, not shown, in a direction towards and away from the lower jig member 60. The upper jig member 81 is integrally formed with a hub thrusting portion 83 in its lower portion. The hub thrusting portion 83 has an outer diameter substantially equal to the outer diameter of the outer flange portion 6 of the hub 4.
Similarly to the assembly device 8 of the first embodiment, the assembly device 9 is provided with an adhesive supplying device, not shown, at an upper portion of the lower jig 60. When the disc substrate 2 is assembled on the lower jig member 61 as later explained, the adhesive supplying device is intruded into a space between the lower jig 60 and the upper jig 80 for dripping the UV curable adhesive to the outer rim of the center opening 3 of the disc substrate 2. The lower jig member 60 is provided with a UV radiating unit 65 formed as a UV light radiating port 66 by being opened on the lateral surface of the lower jig member 60 and by being opened at an upper portion thereof in the disc substrate setting surface 63. A UV light beam 67 is mounted on the UV light beam radiating unit 65 with its radiating surface being directed from the lateral side of the lower jig member 61 towards the disc substrate setting surface 63.
With the above-described assembling device 9 of the second embodiment, the upper jig 80 is raised with respect to the lower jig 60, as shown in FIG. 20. The distal end of the first guide portion 51 of the assembly guide member 50 is protruded and exposed via the guide opening 82 of the upper jig member 81. The disc substrate 2 is set on the disc substrate setting surface 63 of the lower jig member 61, as shown in FIG. 21. In such case, if suffices to set the disc substrate 2 on the disc substrate setting surface 63 so that the center opening 3 is in register with the clearance opening 62, while there is no necessity of precise position matching. The disc substrate 2, set on the disc substrate setting surface 63, is sucked and held on the disc substrate setting surface 63 via the suction opening 64 by actuating the vacuum suction device.
With the disc substrate 2 provisionally held on the lower jig 60, the upper jig 80 is lowered by driving means, not shown, as shown in FIG. 22. Thus the assembly guide member 50, built into the upper jig member 81, positions the disc substrate 2 by the first guide portion 51 being fitted into the center opening 3 of the disc substrate 2 on which the first guide portion 51 is held provisionally. The upper jig 80 is again raised by actuation of the driving means, as shown in FIG. 23. Although the fitting state of the first guide portion 51 of the assembly guide member 50 in the center opening 3 is canceled, the disc substrate 2 is sucked by vacuum suction means in position on the disc substrate setting surface 63 of the lower jig member 61. Although the process step is not shown, the UV curable adhesive is uniformly coated on the outer rim of the center opening 3 by the adhesive supplying unit, as described previously.
The hub 4 is assembled on the raised upper jig 80 by the second guide portion 53 of the assembly guide member 50 being fitted into the spindle shaft opening 7, as shown in FIG. 24. The hub 4 is sucked and held on the end face of the first guide portion 51 of the assembly guide member 50 via the suction opening 56, by actuation of the vacuum suction system, without the risk of detachment. The upper jig 80 is then lowered towards the lower jig 60 by actuation of driving means, not shown, as shown in FIG. 25. The hub 4 is assembled by being fitted into the center opening of the disc substrate 2 which is sucked and held in position by the above-described process on the disc substrate setting surface 63 of the lower jig member 61. The decent of the assembly guide member 50 is terminated when the disc substrate 2 and the hub 4 have been assembled together. However, the descent of the upper jig member 81 is continued. The upper jig member 81 thrusts the hub 4 against the major surface of the disc substrate 2 by the hub thrusting portion 83, as shown in FIG. 26. The disc substrate 2, carrying the hub 4, is irradiated with the UV light beam L from the UV radiating device 67 arranged in the UV light beam radiating unit 65 of the lower jig member 61. The UV light beam L is radiated on the outer rim of the center opening 3 of the disc substrate 2 via the UV light beam radiating port 66 opened on the disc substrate setting surface 63, as shown in FIG. 27. The UV curable adhesive, coated on the outer periphery of the center opening 3, is cured by irradiation with the UV light beam for positively securing the outer peripheral flange portion 6 of the hub 4 onto the major surface of the disc substrate 2 for completing the optical disc 1, as shown in FIG. 28.
When the disc substrate 2 and the hub 4 have been assembled together by the above process, the driving means, not shown, of the assembly device 9 is actuated for raising the upper jig 80 in its entirety, as shown in FIG. 29. By termination of the vacuum suction system, the optical disc 1, comprised of the disc substrate 2 and the hub 4 assembled together, is released from the state in which the disc is held under the force of suction on a disc substrate setting surface 63 of the lower jig 60, so as to be taken out of the assembly device 9.
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A method and apparatus for assembling a hub for magnetically chucking an optical disc on a disc table of a recording/reproducing apparatus under a force of magnetic attraction includes an assembly guide member having a first guide portion movable in a direction perpendicular to one major surface of the disc substrate so as to be engaged in a center opening in the disc substrate, and a second guide portion formed integrally with the first guide portion so that its center axis is aligned with the distal end of the first guide portion. The second guide portion is fitted in a spindle shaft opening in the hub. The assembly guide member having its first guide portion fitted in the center opening for positioning the disc substrate and the second guide portion being engaged in this state in the spindle shaft opening for centering the disc substrate with respect to the hub. The disc substrate and the hub may be assembled together in the correctly centered state via the assembly guide member by a simplified operation with minimum cost, thus assuring reduction in investment cost and improved productivity. In addition, the centering between the disc substrate and the hub, which usually required time-consuming laborious operation, may be achieved easily by employing the assembly guide member, so that the assembly process may be simplified thus lowering the cost of the disc-shaped recording medium.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a locking device, and more particularly to locking device to secure an inner tube in an outer tube of a telescopic tube assembly.
2. Description of Related Art
With reference to FIG. 6 , a conventional locking device ( 50 ) for a telescopic tube assembly having an outer tube ( 40 ) and an inner tube ( 41 ) slidably received in the outer tube ( 40 ) includes a knob ( 51 ) rotatably mounted on a side of the locking device ( 50 ).
When the relative position of the inner tube ( 41 ) is to be readjusted, the operator has to hold the inner tube ( 41 ) to prevent the inner tube ( 41 ) from slipping too far into the outer tube ( 40 ). Then the operator is able to unscrew the knob ( 51 ) and change the relative position of the inner tube ( 41 ) to the outer tube ( 40 ). However, when a distal end of the inner tube ( 41 ) is provided with a heavy load, i.e. an illuminating device, the operator has to struggle to hold the weight of the illuminating device. Therefore, assistance from the other operators is essential. That is, it is almost impossible for a lone operator to finish the adjustment of the telescopic tube assembly, especially when a weighty object is on top of the telescopic tube assembly.
To overcome the shortcomings, the present invention tends to provide an improved locking device to mitigate the aforementioned problems.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide an improved locking device to enable a lone operator to safely finish the adjustment of the relative position of the inner tube relative to the outer tube.
Another objective of the present invention is to eliminate danger to the operator by providing a safety device to prevent excessive movement of the inner tube relative to the outer tube.
Other objects, advantages and novel features 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 perspective view of the locking device applied on a telescopic tube assembly;
FIG. 2 is schematically cross sectional view of the locking device in FIG. 1 ;
FIG. 3 is a schematic view showing the operation of the locking device of the present invention;
FIG. 4 is a schematic view showing the application of the locking device;
FIG. 5 is a schematic view showing an illuminating device is mounted on the telescopic assembly with the locking device of the present invention applied thereto; and
FIG. 6 is side view showing a conventional locking device applied to a telescopic tube assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1 and 2 , a telescopic tube assembly includes an outer tube ( 10 ) and an inner tube ( 11 ) slidably received in the outer tube ( 10 ). The inner tube ( 11 ) has multiple adjusting recesses ( 111 ) defined in an outer periphery of the inner tube ( 11 ) and a guiding groove ( 112 ) defined on the outer periphery of the inner tube ( 11 ) along a longitudinal axis of the inner tube ( 11 ).
A locking device in accordance with the present invention includes an enclosure ( 20 ) partially securely mounted on a peripheral edge of the outer tube ( 40 ) and having a guide ( 201 ) formed on an inner face of the enclosure ( 20 ), a first space ( 21 ) defined in a side face of the enclosure ( 20 ), a first hole ( 22 ) defined through a bottom face defining the first space ( 21 ), a second hole ( 23 ) defined through the enclosure ( 20 ) to be opposite to the first hole ( 22 ) and a second space ( 24 ) defined to communicate with the second hole ( 23 ).
Furthermore, a lever ( 25 ) is received in the first space ( 21 ) and has a proximal end, a distal end, a pivot ( 251 ) and a through hole ( 252 ). The pivot ( 251 ) extends from the lever ( 25 ) and abuts the bottom surface of the first space ( 21 ) to allow the lever ( 25 ) to pivot in the first space ( 21 ). The through hole ( 252 ) is defined through the lever ( 25 ) close to the proximal end. A positioning rod ( 26 ) has a first distal end, a second distal end and a pivot pin ( 263 ). The first distal end is mounted pivotally in the through hole ( 252 ) in the lever ( 25 ). The second distal end of the positioning rod ( 26 ) has a head ( 261 ) corresponding to the adjusting recesses ( 111 ). The pivot pin ( 263 ) extends through the lever ( 25 ) and first distal end of the positioning rod ( 26 ) to allow the positioning rod ( 26 ) to pivot on the lever ( 25 ). A spring ( 262 ) is mounted on the positioning rod ( 26 ) and compressibly received in the first hole ( 22 ) such that when the positioning rod ( 26 ) is moved by the lever ( 25 ), the spring ( 262 ) is able to provide a recoil force to the positioning rod ( 26 ) to return the positioning rod ( 26 ). A knob ( 27 ) having a bolt ( 271 ) integrally formed with the knob ( 27 ) is screwingly extended into the second hole ( 23 ) to abut an abutting block ( 28 ) received in the second space ( 24 ) so that the outer periphery of the inner tube ( 11 ) is engaged by the abutting block ( 28 ). Especially, a safety device is mounted on the outer periphery of the inner tube ( 11 ) to prevent excessive movement of the inner tube ( 11 ) relative to the outer tube ( 10 ).
With reference to FIG. 3 , it is noted that before the locking device of the present invention is in application, the head ( 261 ) of the positioning rod ( 26 ) is received in one of the adjusting holes ( 111 ) so as to secure the position of the inner tube ( 11 ) relative to the outer tube ( 10 ). When the lever ( 25 ) is depressed, the positioning rod ( 26 ) leaves the corresponding adjusting recess ( 111 ) to allow the operator to adjust the relative position of the inner tube ( 11 ) to the outer tube ( 10 ). After adjustment of the relative position of the inner tube ( 11 ) to the outer tube ( 10 ), the spring ( 262 ) provides a recoil force to the positioning rod ( 26 ) to force the positioning rod ( 26 ) to return to its original position such that the head ( 261 ) of the positioning rod ( 26 ) is received in a corresponding one of the adjusting recesses ( 111 ) of the inner tube ( 11 ) and the adjustment of the telescopic tube assembly is accomplished.
However, during the adjustment of the telescopic tube assembly, the operator is able to use the abutting block ( 28 ) to secure the position of the inner tube ( 11 ) in the outer tube ( 10 ). That is, the operator is able to use the abutting block ( 28 ) to increase the friction between the abutting block ( 28 ) and the outer periphery of the inner tube ( 11 ) by rotating the knob ( 27 ) such that the position of the inner tube ( 11 ) in the outer tube ( 10 ) is temporarily secured. Alternatively, the operator is able to use the abutting block ( 28 ) as an auxiliary securing device to secure the position of the inner tube ( 11 ) relative to the outer tube ( 10 ).
Further, the guide ( 201 ) slidable in the guiding groove ( 112 ) is able to smoothen the sliding movement of the inner tube ( 11 ) to the outer tube ( 10 ).
Preferably, the safety device ( 12 ) which is mounted on the outer periphery of the inner tube ( 11 ) is a boss. The boss ( 12 ) is integrally formed on the outer periphery of the inner tube ( 11 ) such that excessive sliding movement of the inner tube ( 11 ) relative to the outer tube ( 10 ) is prevented.
With reference to FIGS. 4 and 5 , it is noted that when a loudspeaker ( 31 ) or an illuminating device ( 32 ) is mounted on top of the free end of the inner tube ( 11 ), the locking device of the present invention is able to safeguard the operator from possible injury by the sudden falling of the inner tube ( 11 ) due to the weight on top of the telescopic tube assembly.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A locking device has an enclosure partially securely mounted on a peripheral edge of the outer tube and having a lever pivotally connected to the enclosure; and a positioning rod securely connected to a side of the lever to be driven by the lever and having a head formed on a free end of the positioning rod to correspond to one of the adjusting recesses of the inner tube such that pivotal movement of the lever is able to drive the head of the positioning rod to selectively move away from the corresponding adjusting recess to allow the inner tube to move relative to the outer tube.
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BACKGROUND OF THE INVENTION
This invention relates to a non-irritating composite suture of silk and hydrophobic thermoplastic elastomers containing at least 25% soft segments which composite suture retains the handling qualities of silk and is also capable of retaining at least thirty-two percent of its initial mechanical strength in vivo after eight weeks. This composite suture has surface barrier properties of a monofilament and tissue reaction comparable to common synthetic sutures. This invention also relates to the process for preparing the composite suture.
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e., monofilament sutures, or as multifilament strands in a braided, twisted or other multifilament construction. Silk does not lend itself to the fabrication of monofilament sutures and is accordingly generally used in one of the multifilament constructions, preferably the braided form. This results in a silk suture having desirable handling characteristics, being sufficiently flexible and having good knot-tying ability and knot security. However, presently available untreated silk sutures are known (a) to provoke a significant tissue reaction in the biologic environment, (b) have a significant strength loss in living tissues (typically a 2-0 silk suture retains about twenty percent of its original strength after eight weeks, post-implantation, and (c) to lack the surface barrier properties needed for retarding cellular infiltration into the suture interior in living tissue.
The composite suture of the present invention displays equivalent handling properties to those of the untreated braided silk suture, it elicits reduced tissue reaction after seven days and later post-implantation intervals, and when implanted intramuscularly, is more effective in retarding cellular infiltration due to the monofilamentous geometry of the composite suture and it is characterized by improved strength retention after fifty-six days post-implantation.
The prior art discloses a number of methods for coating sutures in general. Coating material for sutures normally would require low surface friction characteristics so as to facilitate the knot-tying ability of the resultant coated suture. Contrary to such expectations, the present invention utilizes an elastomer (which has high surface friction characteristics) in preparing the present composite suture.
Braided silk sutures are desirably flexible due to the interlocking geometry of the fibers. in accordance with the present invention, a multifilament silk suture is treated with a hydrophobic, limp thermoplastic elastomer in order, not only to coat the suture, but to substantially fill all the interstices between the silk filaments. It has been found, surprisingly, that the particular elastomers utilized in accordance with the present invention, when filling the spaces between the silk fibers, do not adversely affect the flexibility of the suture as a whole.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 3,527,650 teaches that multifilament non-absorbable sutures can be improved with respect to tie-down performance by depositing solid particles of polytetrafluoroethylene and a binder resin on the external surface. No infiltration of this coating to the suture interior was described in this patent. Furthermore, the coating flakes off during use, especially during knot tie-down.
According to U.S. Pat. No. 3,942,532, non-absorbable sutures can be improved with respect to tie-down performance by coating them with a linear polyester having a molecular weight between about 1,000 and about 15,000 and at least two carbon atoms between the ester linkages.
This patent pertains to simple linear thermoplastic polyesters which are highly crystalline, low melting materials. These are expected to impart lubricity and are not (a) segmented in structure, (b) elastomeric or (c) significantly capable of contributing to the mechanical properties of braided sutures (including silk) to any discernible extent.
U.S. Pat. No. 3,297,033 discloses that synthetic absorbable sutures can be coated with coating materials used on conventional sutures, such as a silicone or beeswax to modify handling. However, it does not describe any material or system that can be combined with braided silk sutures to form the unique composite sutures subject of the present invention.
U.S. Pat. No. 4,043,344 shows that the handling characteristics and particularly the knot run down and tissue drag characteristics of non-absorbable sutures are improved by a coating with a lubricating film of bioabsorbable copolymer having copolyoxyethylene blocks and polyoxypropylene blocks. The copolymer has a molecular weight such that it is pasty to solid at 25° C. This lubricant coating is described as absorbable (in vivo) in less than two days which results in improved long term knot security.
The lubricant coating as described should (a) have a low molecular weight, about 8350 Dalton, and low Tm and hence would be expected to have hardly any integrity at usual levels of stress; (b) it is soluble in the biologic environment and likely to migrate to the surrounding tissue in two days to cause additional foreign body reaction; (c) it is water-soluble and hence would be expected to provide minimum lubricity during wet tie-down and (d) would not be expected to render a commercial silk suture less irritating to tissue and more resistant towards losing its breaking strength, for the coating does not act as a hydrophobic inert barrier about the braid components and does not mask effectively the undesirable morphological features of a braided suture.
U.S. Pat. No. 4,185,637 discloses a multifilament suture having improved tie-down properties, said suture being coated with from about 1 to 5 percent by weight of the dry residue of a composition comprising a gel of a polyvalent metal ion salt of C 6 or higher fatty acid in a volatile organic solvent.
The coating described by this patent can only serve as a lubricant, for it is a low molecular weight system that cannot impart any discernible physical changes to the mechanical integrity of the suture braid construction. If used for silk sutures, this absorbable coating would not be expected to decrease the tissue reaction or increase the strength retention.
According to U.S. Pat. No. 4,105,034 the tie-down properties of a multifilament surgical suture are improved by coating the suture with an absorbable composition comprising a low molecular weight polyalkylene oxalate.
If silk sutures were to be treated with such a coating, the latter would be expected to only impart desirable surface lubricity, without affecting the tissue reaction or breaking strength retention of the implanted suture in any positive sense. This is simply because the coating is an absorbable low molecular weight material which limits the residence time about the fibers and the effect on the suture properties of the braid.
Canadian Pat. No. 902439 describes a polyfilamentary silk suture having a plurality of fine solid particles of insoluble synthetic polymeric material incorporated in the interstices thereof, in an amount sufficient to embue the suture with substantially the properties of a monofilament. However, these particles cannot be expected to act as a hydrophobic inert barrier about the braid components and accordingly, the method of said reference is not likely to increase the tissue reaction or increase the strength retention of the suture.
In view of the above discussion it will be seen, with respect to non-absorbable sutures such as braided silk sutures, that the prior art does not disclose any effective method for reducing tissue reaction at later post-implantation periods, retarding cellular infiltration or bringing about improved strength retention after eight weeks post-implantation. It is accordingly an object of the present invention to prepare a composite suture which is non-irritating and retains the handling qualities of silk, and which is capable of retaining a higher proportion of the initial mechanical strength, in vivo, after eight weeks, than in the case of an untreated silk suture per se. It is a further object of the present invention to provide a composite suture having surface barrier properties comparable to those of a monofilament and tissue reaction comparable to common synthetic sutures. It is a further object of the invention to provide a composite silk-elastomer suture in which the elastomer substantially fills all the interstices between the silk filaments and having properties such that the elastomer nevertheless permits the individual components of the silk to flex in such a way that the flexibility of the silk suture, as a whole, is not impaired. It is yet a further object of the present invention to provide a composite silk-elastomer suture wherein the primary strength is provided by the silk (since the elastomer matrix is much less strong).
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a non-irritating composite suture retaining the handling qualities of silk, which, in the case of size 5-0, is capable of retaining at least 32% of its initial mechanical strength, in vivo, after eight weeks; said suture having surface barrier properties against cell infiltration comparable to those of a monofilament and tissue reaction comparable to common synthetic sutures; comprising multifilament silk embedded in a hydrophobic, limp thermoplastic elastomer; said elastomer comprising copolymers having hard and soft components, said soft components comprising about 25-80% by weight of said elastomer, depending upon the melting temperature and crystallizability of the hard components, said elastomer having a suitable molecular weight sufficient to provide a solution viscosity that is consistent with optimum diffusion into the interior of the suture structure, resulting in a high integrity matrix which does not flake when the suture is subjected to mechanical stress.
In accordance with the preferred embodiment of the present invention, the silk is of braided construction and the elastomer is selected from the group consisting of copolymers having the following recurring units: ##STR1## wherein each G individually represents an alkylene group of from 2 to 6 carbon atoms, and p is 9 to 15, e and f each represent a number having a value greater than 1 such that the B units comprise 50 to 80 weight percent of the copolymer and the A units comprise the remainder; wherein Z represents 1,4-phenylene, 1,3-phenylene or trans-1,4-cyclohexylene;
(Q) a copolymer consisting essentially of a multiplicity of recurring A [poly(alkylene terephthalate, isophthalate or cyclohexane-1,4-dicarboxylate)] and B [poly(alkylene dimerate)] units having the following general formula: ##STR2## wherein x and y are integers, such that the B units comprise 50 to 80 weight percent of the copolymer, and the A units comprise the remainder; ##STR3## denotes a branched hydrocarbon chain containing from 24 to 32 carbon atoms and Z and G are as hereinabove defined;
(R) a copolymer consisting essentially of a multiplicity of recurring poly(alkylene) terephthalate, isophthalate or cyclohexane-1,4-dicarboxylate, and poly(alkylene) alkyl or alkenyl succinate units having the following general formula: ##STR4## wherein Alk 1 is a linear or branched alkyl or alkenyl radical with a chain length of about 4 to 30 carbon atoms and g and h are integers such that the B units comprise 50 to 80 weight percent of the copolymer and the A units comprise the remainder; and Z and G are as hereinabove defined;
(S) a random copolymer having the following general formula: ##STR5## wherein J is either: ##STR6## wherein Alk 2 is alkyl or alkenyl moieties with a chain length of 8 to 30 carbon atoms; ##STR7## denotes a branched hydrocarbon chain with an estimated formula of C 32 H 60 , or ##STR8## wherein p is 9 to 15 and G is as hereinabove defined and R' is an aliphatic or aromatic disubstituted moiety and wherein e and f are such that the B units comprise about 25 to 50% by weight of the copolyester and the A units comprise the remainder.
The elastomer of the present invention possesses an inherent viscosity which ranges between about 0.02 and 1.4, and has a melting temperature by thermal microscopy of between about 80° and 180° C. The elastomer comprises between 5 and 50% by weight of the total composite system and preferably has a molecular weight of at least 2000 Dalton, and most preferably at least 10,000 Dalton. Preferably the soft segments of the elastomer of the formulae (P), (Q) and (R) comprise between 55% and 75% by weight thereof and in the instance wherein the elastomer has the above formulae (P), (Q), or (R), the soft segments comprise between 60 and 70% thereof. Furthermore, in the instance wherein the elastomer has the formula (S), the soft segments preferably comprise between 30 and 50% thereof.
In the instance wherein the elastomer has the formula (P), the inherent viscosity in HFIP (hexafluoro-2-propanol) is preferably between 0.8 and 1.3. In the instance wherein the elastomer has the formula (Q) or (R), the inherent viscosity in hexafluoro-2-propanol is preferably between 0.2 and 0.7; and in the instance wherein the elastomer has the formula (S) the inherent viscosity in hexafluoro-2-propanol is preferably between 0.3 and 0.6.
Within the scope of the present invention is a composite suture, having a surgical needle attached to at least one end, preferably in a sterile condition.
In this connection, it is important that sutures be presented to the operating room in sterile condition. Several methods of achieving sterility are known. Of these the most commonly employed method for silk sutures consists of exposure to 2.5 Mrads of γ irradiation derived from a Cobalt 60 source. It is important therefore that the thermoplastic elastomers used in this invention be capable of resisting exposure to this level of irradiation without significant change in their physical properties.
In accordance with the present invention, there is also provided a method of preparing a non-irritating and strength retaining composite silk thermoplastic elastomer suture comprising the steps of (a) treating a multifilament silk suture with a hydrophobic, limp thermoplastic elastomer dissolved in a solvent therefor at a temperature between 20° and 80° C. but preferably between 30° and 50° C. in order to coat said suture, said elastomer comprising copolymers having hard and soft components, said soft components comprising about 25-80% by weight of said polymer; said elastomer having a suitable molecular weight sufficient to provide a solution viscosity that is consistent with optimum diffusion into the interior of the suture structure, resulting in a high integrity matrix which does not flake when the suture is subjected to mechanical stress; and optionally, (b) rapidly heating the treated suture at a temperature between about 340° and 500° C. to obtain a continuous and consistent impregnation of the multifilament silk suture, and to substantially fill all the interstices between the silk filaments.
DESCRIPTION OF PREFERRED EMBODIMENTS
The preferred synthetic matrix (P), used to prepare the composite suture of the present invention, is a segmented polyether-ester made by the condensation of dimethyl terephthalate, polyoxytetramethylenediol (molecular weight 650 to 10,000 Dalton and preferably 1000 Dalton) and butanediol in the presence of a typical polyesterification catalyst [e.g. Ti(OBu) 4 , Ti(OBu) 4 +Mg(OAc) 2 ], optionally, an antioxidant of the hindered phenol type (e.g. Irganox 1098 [N,N'-hexamethylene bis (3,5-ditert-butyl-4-hydroxyhydrocinnamide] at 0.1 to 1%) or aromatic secondary amine type (e.g. Naugard 445 [4,4'bis(α,α-dimethylbenzyl)-diphenylamine] at 0.2 to 1%). The polymerization can be achieved under conventional conditions of temperature, pressure and stirring. The resulting polymer is characterized by having long sequences of crystallizable polybutylene terephthalate (4GT) units linked to low Tm or liquid (at room temperature) poly(polyoxytetramethylene) terephthalate (POTMT); these units are commonly referred to as hard and soft segments, respectively. The structure of the matrix material can be represented as follows: ##STR9##
Although some of these segmented copolyesters are availble commercially and disclosed broadly in U.S. Pat. No. 3,023,192 (sold in the U.S. under the trade name Hytrel) the relatively high proportion of hard segments and high molecular weight of the commercially available products render them less suitable for use in the present invention, and accordingly special compositions are made in order to provide optimum matrixes for the composite sutures of this invention. The composition and physical properties of two typical matrix materials are shown in Table I. If tested in the appropriate physical form (e.g. compression molded film Die C) these polymers are expected* to have an ultimate elongation of 300%, ultimate tensile strength of 5000 psi and a flex. modulus of <10,000 psi.
TABLE 1______________________________________Properties of Two Typical Matrix MaterialsPolymer No.: 135 137______________________________________Soft Segment Content 63 71Wt. % (determined by NMR)Inherent Viscosity in HFIP 1.27 1.12(hexafluoro-2-propanol)Melting Temperature by Microscopy 126-143 138-145° C.% Crystallinity, by X-ray -- 15-20______________________________________
Based on available physical data* on compositions other than those described in Table I, the glass transition temperature of polymers #135 and 137 are expected to be well below -40° C. irrespective of the analytical procedure used for the Tg measurement.
The crystallinity detected in sample #137 is shown to be due to the hard 4GT segments. Considering the available data on Hytrel-type polymers* the molecular weight of polymers #135 and 137 can be equal to or exceed 10,000 Dalton.
The synthetic matrix Q) is prepared by the polycondensation of dimethyl terephthalate, dimer acid, or preferably its diisopropyl ester and a polymethylene diol (n=4 to 8, and preferably 4). ##STR10##
The preferred parent dimer acid of the diisopropyl ester utilized in the polymerizations is derived from high purity oleic acid and is formed by a clay catalyzed high pressure dimerization of the oleic acid in the presence of water. The mechanism of formation of the dimer acid is probably free radical in nature and the product is believed to consist of a mixture of acyclic unsaturated C 36 acids. The unsaturated materials are then hydrogenated and the dimer ester used in the present polymerization possesses a slight degree of unsaturation as evidenced by an Iodine number of 5. In addition to the C 36 acids that make up the dimer acid there is present some monofunctional acid (iso-stearic) and a certain quantity of trifunctionality in terms of a "Trimer (C 54 ) acid." The former may act as a chain terminator and the latter as crosslinking agent. Detailed structures of the C 36 components of the dimer acid have not been elucidated as yet and the diacid is sometimes represented graphically as shown below (with four almost equal branches). ##STR11##
The reaction may be run in the absence or preferably in the presence of stabilizers taken from the types of hindered phenols or secondary aromatic amines. An example of the former is Irganox 1098 sold by Ciba-Geigy [N,N'-hexamethylene bis (3,5-ditert-butyl-4-hydroxy hydrocinnamide)] and an example of the latter is Naugard 445 sold by Uniroyal [4,4'-bis(α,α-dimethylbenzyl)diphenyl amine)]. Oxides and alkoxides of numerous polyvalent metals may be employed as catalysts. A preferred catalyst for the polymerization is a mixture of about 0.1% tetrabutyl orthotitanate and about 0.005% magnesium acetate (percentages based on total charge weight).
The polymerization is run in two stages. In the first stage, run under nitrogen at temperatures ranging from 160° to 250° C., polycondensation via transesterification and esterification occurs resulting in oligomeric chains. These are converted to materials having high degree of polymerization in the subsequent step run at 240° to 255° C., at pressures of less than 1 mm of mercury.
The resulting polymers exhibit inherent viscosities (measured in hexafluoroisopropyl alcohol) of 0.5 to 0.9. The Tm of the polymers, depending on composition, varies from 100° to 180° C.
Polymerization Procedure for Preparing Matrix Q
For each mole of the desired amounts of dimethyl terephthalate and diisopropyl dimerate (obtained from Emery Industries as Emerest 2349), a 1.3 to 2.2 molar excess of a polymethylene diol and a given stabilizer are placed under nitrogen into a dry reactor fitted with an efficient mechanical stirrer, a gas inlet tube and a takeoff head for distillation. The system is heated under nitrogen to 160° C. and stirring is begun. To the homogeneous stirred solution the required amount of catalyst is added. The mixture is stirred and heated under nitrogen for given time periods of 190° C. (2-4 hours) and 220° C. (1-3 hours). The temperature is subsequently raised to 250° to 255° C. and over a period of 0.4-0.7 hours, the pressure is reduced in the system to below 1 mm/Hg (preferably in the range of 0.05 mm to 0.1 mm). Stirring and heating under the above conditions is continued to the completion of the polymerization. The endpoint is determined by either (a) estimating visually the attainment of maximum melt viscosity, (b) measuring inherent viscosity or melt indices of samples removed from the reaction vessel at intermediate time periods, and (c) using a calibrated torquemeter immersed into the mixture. In practice, depending on the terephthalate/dimerate ratio, in vacuo reaction times vary from 2 to 13 hours.
At the end of the polymerization cycle the hot mixture is equilibrated with nitrogen and allowed to cool slowly. The reaction product is isolated, chilled in liquid nitrogen and ground. The ground chips are dried at 80° to 110° C. for 8 to 16 hours under vacuum of 1 mm or less.
Copolyesters (Q) of aromatic diacids (e.g. terephthalic acid) and "dimer acids" of C 18 unsaturated fatty acids have been known for some time in the technical and patent literature.
Hoeschele [Angew.Makormol.Chem. 58/59, 229(1977)] disclosed the preparation of thermoplastic PBT (polybutylene terephthalate)/dimerate systems.
According to a number of patents [U.S. Pat. No. 3,390,108 (1968), U.S. Pat. No. 3,091,600 (1963) and British Pat. No. 994,441 (1965)], PET (polyethylene terephthalate) copolymers were disclosed containing small amounts of dimerate moieties.
In a few instances higher concentrations of dimerates are disclosed as being incorporated into PET copolymers [Belgium Pat. No. 649,158 (1964), U.S. Pat. No. 3,383,343 (1968) and French Pat. No. 1,398,551 (1965)]. Copolymer Q) is also disclosed in copending U.S. application Ser. No. 328,351.
The general structure of the poly[polymethylene terephthalate-co-(2-alkenyl or alkyl) succinate] R), useful in forming the composite sutures of the present invention, may be expressed as follows: ##STR12## wherein Z and G are as defined hereinabove.
The structure belongs to the copolymer type and g and h can be predicted from the quantities of starting materials;
"G" is preferably 1,4-butylene, and
"Alk 1 " is a linear or branched alkyl, or alkenyl (preferably a 2-alkenyl) group with a chain length of about 4 to 30 carbon atoms with the preferred range lying between about 12 and 22 carbon atoms.
The preferred polymers R) useful in the present invention are prepared by the polycondensation of dimethyl terephthalate, an alkyl (or 2-alkenyl) succinic anhydride and a polymethylene diol: ##STR13##
The required diols are commercially available. The substituted succinic anhydrides can be prepared by the "ene" reaction of maleic anhydride and an olefin (preferably a terminal olefin): ##STR14##
The reaction may be run in the absence or, preferably, in the presence of stabilizers such as hindered phenols, (e.g., Irganox 1098) or secondary aromatic amines, (e.g., Naugard 445). Acetates, oxides and alkoxides of numerous polyvalent metals may be employed as the catalyst such as, for example, zinc acetate, or magnesium acetate in combination with antimony oxide, or zinc acetate together with antimony acetate. However, the preferred catalyst for the polymerization is a mixture of about 0.1% (based on total charge weight) tetrabutyl orthotitanate and about 0.005% magnesium acetate.
The polymerization is run in two stages. In the first stage, run under nitrogen at temperatures ranging from 160° to 250° C., polycondensation via transesterification and esterification occurs, resulting in lower molecular weight polymers and oligomers. These are converted to higher molecular weight materials in the subsequent step run at 240° to 255° C., at pressures of less than 1 mm of mercury. The resulting polymers, exhibit inherent viscosities (measured in hexafluoroisopropyl alcohol) of 0.3 to 0.9. A representative molecular weight determination of one of the polymers by light scattering gives a value of 78×10 3 Daltons. The Tm of the polymers, depending on composition varies from about 100° to 180° C.
POLYMERIZATION PROCEDURE FOR PREPARATION OF POLYMER R
The desired amounts of dimethyl terephthalate, a 2-alkenyl succinic anhydride (or an alkylsuccinic anhydride), a 1.3 to 2.0 molar excess of a polymethylene diol and a given stabilizer are placed under nitrogen into a dry reactor fitted with an efficient mechanical stirrer, a gas inlet tube and a takeoff head for distillation. The system is heated under nitrogen to 160° C. and stirring is begun. To the homogeneous stirred reaction mixture the required amount of catalyst is added. The mixture is then stirred and heated under nitrogen for given time periods at 190° C. (2-4 hours) and 220° C. (1-3 hours). The temperature is subsequently raised to 250° to 255° C. and over a period of 0.4 to 0.7 hours, the pressure is reduced in the system to about 1 mm/Hg (preferably 0.05 mm to 0.1 mm). Stirring and heating under the above conditions is continued to complete the polymerization. The endpoint is determined by either (a) estimating visually the attainment of maximum belt viscosity, (b) measuring inherent viscosity or melt indices of samples removed from the reaction vessel at intermediate timer periods, or (c) using a calibrated torquemeter (attached to the stirrer of the reactor).
At the end of the polymerization cycle the molten polymer is extruded and pelletized (or slow cooled in the glass reactor, isolated and ground in a mill). The polymer is dried at 80° to 110° C. for 8-16 hours under reduced pressure. One alternate method of polymerization is set forth in U.S. Pat. No. 3,890,279.
Said U.S. Pat. No. 3,890,279 and U.S. Pat. No. 3,891,604 as well as copending U.S. application No. 218,998, disclose copolymer R). The flexible polyesters (S) useful in the present invention have rigid AB type ester units of an alkylene oxybenzoate and one of the following flexible AA-BB type ester sequences of (1) an alkylene, 2-alkenyl (or alkyl) succinate, (2) an alkylene dimerate (from a dimer of a long chain unsaturated fatty acid), (3) a dicarboxylate of poly(oxytetramethylene) glycol. Preferrred copolymers (S) have the following general formula: ##STR15## wherein G is defined hereinbefore and e and f can be determined by the amount of starting materials and J is either: ##STR16## wherein Alk 2 is alkyl or alkenyl with a chain length of 8 to 30 carbon atoms; ##STR17## denotes a branched hydrocarbon chain with an estimated formula of C 32 H 60 , or ##STR18## wherein R' is an aliphatic, cycloaliphatic or aromatic disubstituted moiety and p is about 10. The J units comprise about 25-50% by weight of the copolyester.
The general structures of the preferred copolymers (S) useful in the present invention may be expressed as follows: ##STR19##
Copolymers (S) of type I are prepared typically by the polycondensation of p-(4-hydroxy-n-butoxy) benzoic acid (HB-OB) (or its methyl ester) (MB-OB), an alkenyl (or alkyl) succinic anhydride (or the corresponding dialkyl succinate) and a polymethylene diol in the presence of a suitable catalyst and preferably an antioxidant. Typical illustration of the reaction can be given as follows: ##STR20##
The MB-OB can be prepared according to the following tpical reaction scheme: ##STR21##
Copolymers (S) of type II are prepared typically by the polycondensation of p-(4-hydroxy-n-butoxy) benzoic acid (or its methyl ester), the dialkyl ester of dimer acid (or the free acid) and a polymethylene diol in the presence of a suitable catalyst and preferably an antioxidant. Typical illustration of the reaction can be given as follows: ##STR22##
The parent dimer acid of the diisopropyl ester utilized in the polymerization is derived by a catalyzed high pressure dimerization of high purity oleic acid.
Copolymers (S) of type III are prepared typically by the polycondensation of p-(4-hydroxy-n-butoxy) benzoic acid (or its alkyl ester), dimethyl terephthalate, and polyoxybutylene diol (Mol. Wt.=1000 Daltons), a suitable catalyst and stabilizer. Typical illustration of the reaction can be given as follows: ##STR23##
The polymerization may be conducted either in the absence or preferably in the presence of stabilizers of the hindered phenol or secondary aromatic amine type. An example of the former is Irganox 1098 and an example of the latter is Naugard 445. As catalyst, oxides and alkoxides of numerous polyvalent metals may be employed. However, the preferred polymerization catalysts are combinations of (a) tetrabutyl orthotitanate and/or magnesium acetate, (b) Mg(OAc) 2 and/or Sb 2 O 3 , and (c) combinations of tin and antimony catalysts, such as BuSnO (OH) and Sb 2 O 3 .
The polymerization is conducted in two stages. In the first stage, run under nitrogen at temperatures ranging from 160° to 250° C. polycondensation via transesterification and esterification occurs resulting in lower molecular weight polymers and oligomers. These are converted to higher molecular weight materials in the subsequent step run at 240° to 260° C., at pressures of less than 1 mm of mercury.
Polymerization Prodedure for Preparation of Polymer (S)
The desired amounts of monomers (and prepolymers as in system III) and a given stabilizer (optional) are placed under nitrogen into a dry reactor fitted with a mechanical stirrer, a gas inlet tube and a take-off head for distillation. The system is heated under nitrogen at 100° to 160° C. and stirring is begun. To the homogeneous stirred solution the required amount of catalyst is added. The mixture is then stirred and heated under nitrogen for given time periods at 190° C. (2-4 hours) and 220° C. (1-3 hours). The temperature is subsequently raised to 250° to 260° C. and over a period of 0.4-0.7 hours the pressure is reduced in the system to below 1 mm/Hg (preferably in the range of 0.05 mm to 0.1 mm). Stirring and heating under the above conditions is continued to the completion of the polymerization. The end point is determined by either (a) estimating visually the attainment of maximum melt viscosity, (b) measuring inherent viscosity or melt indices of samples removed from the reaction vessel at intermediate time periods, and (c) using a calibrated torquemeter immersed into the reaction mixture. In practice, depending on the copolymer composition, in vacuo reaction times varies from 2 to 8 hours.
At the end of the polymerization cycle the hot mixture is equilibrated with nitrogen and allowed to cool slowly. The reaction product is isolated, cooled in liquid nitrogen, and then ground. (In the case of metal reactors the hot melt is extruded at the bottom of the vessels into Teflon covered metal trays.) The ground chips are dried at 60° to 110° C. for 8-32 hours under a vacuum of 1 mm or less.
Copolymer (S) is disclosed in copending U.S. application Ser. No. 253,418.
In accordance with the present invention, pure silk filaments of braided construction are preferably used (a wide range of sizes being available). Addition of the elastomer to the silk does not significantly alter the diameter thereof. The elastomers utilized in accordance with the present invention are designed to be soft, ductile and elastomeric but capable of retaining their mechanical integrity under the ordinary mechanical stresses that the composite suture may be subjected to during end use. Retention of physical form and mechanical integrity is achieved by having quasi-crosslinks due to the crystallites of the crystaline phase in this system. This constitutes about 5 to 35% of the weight of the polymer. The low modulus and "soft handle" of the polymer are associated with the soft component of the polymer which comprises between about 25% and 80% by weight thereof [for polymers (P), (Q) and (R), the soft components comprise between 50% and 80% by weight thereof, preferably between 55% and 75%, and for polymer (S), the soft component comprises between 25% and 50%, preferably 30 % to 50% by weight]. By virtue of their compositions, these quasi-crosslinked systems can be made to flow above the melting temperature (Tm) of the hard block. These thermal characteristics of the matrix material are of importance in connection with the optimal development of the composite suture, for it is then possible to rapidly sinter the matrix about the fibers of the silk braid at a temperature of above 200° C., without causing thermally induced degradation of the silk.
Suitable solvents for applying the elastomer matrix material to silk are halocarbons or mixtures of halo carbons with aromatics, methylene chloride being referred. Methylene chloride was selected for (a) its ability to induce certain amounts of swelling of the silk braid so as to ensure an ultimate strong joint between the braid components and the elastomeric matrix; (b) its ability to provide polymer solutions in a preferred case, with 20 to 5% concentrations having low Brookfield viscosities; this facilitates the impregnation of the braid with these solutions and (c) its high fugacity under mild devolatilization conditions, for drying the composite suture.
The elastomer is applied to the silk suture from a warm solution in a suitable solvent, as discussed above, especially dichloromethane. The temperature of the solution and the concentration of the polymer in the solution are not critical but it is preferred to have a temperature close to the boiling point of the solvent (about 40° C. in the case of dichloromethane) and a concentration which will not substantially increase the viscosity of the solution.
In order to carry out the process of the present invention, the braided silk suture is passed in a continuous process through a warm solution of elastomer, then immediately above the solution surface through a felt wipe, then vertically upward to air dry the treated suture over a short distance (e.g. 2 to 3 feet). The treated suture is then submitted to a rapid heating process in which the suture travels through a hot air zone to momentarily melt the elastomer layer inside the braided silk suture in order to substantially fill all interstices between the silk filaments. The temperature of the heated zone is adjusted for optimum polymer infiltration and depends upon the polymer used, the speed of the threadline and the suture diameter.
Typical temperatures of the hot air medium used for sintering during the rapid heat treatment range between 340° C. and 500° C. This temperature range is not necessarily the same as that of the suture itself. In the instance wherein the polymer has the structure (P) and the silk suture is size 2/0 travelling at 14 feet per minute, the temperature is preferably 415° C., the length of the heated zone being 22 centimeters.
The composite sutures of the present invention are extremely inert and have a minimal to very slight tissue reaction and are impervious to cellular ingrowth. They also exhibit a greater strength retention after eight weeks than silk coated with beeswax. These properties are demonstrated by the following studies:
In Vivo Performance of the Composite Suture
Needle Attachment and Sterilization
Needles are attached by hand swaging with a crimping tool and all samples are Cobalt sterilized.
In Vivo Implantation
Tissue Reactions of Polymer (P) Coated Silk Implanted in Rats
Materials
1. Materials of the following description are implanted, Polymer (P) being the product of Example 2:
______________________________________Sample No. Size Coating Treatment______________________________________1 2-0 Polymer (P) coating2 2-0 Wax coated control3 5-0 Polymer (P) coating4 5-0 Wax coated control______________________________________
2. Amount of Material Required for Tissue Reaction
Twenty-two needled strands at least eight inches long for each sample; strands are fitted with drilled straight tapered needles.
3. All samples are sterilized by Cobalt 60 .
Procedures
1. Tissue Reaction Study
A. Animals--Rats, female, Sprague Dawley, weight 150 to 200 grams. Thirty-six animals are used.
B. Implantation Periods--7, 28 and 56 days.
C. Experimental Design:
Implantation of samples for tissue reaction are carried out according to the following design:
______________________________________ Periods in Days/No. of RatsSample No. 7 28 56______________________________________1 3 3 32 3 3 33 3 3 34 3 3 3______________________________________
D. Standard conditions of anesthesia and aseptic procedures are observed during suture preparation and surgical implantation.
Utilizing one strand per side, 2 cm segments of each suture are implanted in the right and left gluteal muscles, two implants per side. Strands from the same suture sample are implanted on both sides of each rat.
Rats are sacrificed according to experimental design after period of 7, 28, and 56 days. The gluteal muscles containing implants are excised and preserved in formalin fixative. A single block is cut transversely from each gluteal muscle and a single cross section of the two implant sites are stained with Hematoxylin and Eosin for microscopic evaluation. This procedure yields twelve sites per sample per period for evaluation.
E. Evaluation
1. Tissue Reaction Evaluation
A method modified from that described by Sewell, Wiland and Craver, (Surg., Gynecol. and Obstet. 100:483-494, 1955) is utilized to assess responses to implanted sutures. In this scheme the width of the reaction zone measured along the radius from the center of the suture cross section, is graded as:
______________________________________ Assigned Grade______________________________________ 0-25 microns 0.525-50 microns 1.0 50-200 microns 2.0200-400 microns 3.0400-600 microns 4.0______________________________________
Cellular response is graded from 0 to 4 based on increasing concentrations of cells in the reaction zone. A grade of 0.5 is assigned where only a few cells are widely scattered in the reaction zone, while a grade of 4 is assigned where a high cellular concentration is present in the site.
Weighting factors are assigned to zone of reaction and inflammatory cells in computing reaction score as follows:
______________________________________Characteristic Weighting Factor______________________________________Width of Zone 5Overall cell density 3Neutrophils 6Giant cells 2Lymphocytes/plasma cells 1Macrophages 1Eosinophils 1Fibroblasts/fibrocytes 1______________________________________
A sample score is computed as follows:
______________________________________Parameter Grade × Weighting factor = Score______________________________________Zone 2 5 10Cell density 2 3 6Macrophages 2 1 2Giant cells 1 2 2Fibroblasts 2 1 2Total Score 22______________________________________
Adjectival ratings assigned to reaction scores are arbitrarily assigned within the following limits: 0-none; 1-8 minimal; 9-24 slight; 25-40 moderate; 41-56 marked; over 56, extensive.
2. Cellular Invasion of Strands
The extent of cellular invasion of suture fibrils is estimated subjectively as: none, minimal, slight, moderate or marked; these ratings correspond approximately to 0, 25, 50, 75 and 100 percent of suture invaded.
Determination of Tissue Reaction
The implants are recovered after the designated intervals and fixed in buffered formalin. Using standard histologic techniques, Hematoxylin and Eosin stained slides of the muscle cross-sections are prepared and examined microscopically, twelve sites per sample per period. Tissue reactions are evaluated according to the modified Sewell-Wiland method as described above (See Tables 2 and 3).
In addition, the muscle cross-sections containing the polymer (P) treated silk are stained with Oil Red 0 to visualize the presence of the polymer inside the silk braid.
Calculation of the tissue reaction area is accomplished by measuring the reaction diameters using an ocular micrometer. Since the shape of the tissue reaction tends to be elliptical, the formula for the area of an ellipse, A=(D 1 ×D 2 )/4×II is used to calculate these areas. The suture is included in these diameter measurements (See Tables 2 and 3).
The measurements of cellular invasion inside the silk braids are estimated subjectively as a percentage of suture area invaded.
DETERMINATION OF IN VIVO TENSILE STRENGTH LOSS
Breaking Strength Evaluation of Coated Silk Sutures After Implantation in Rats
The purpose of this study is to determine the breaking strength of silk sutures coated with a Polymer (P) coating (product of Example 2) at baseline (0 days), 7, 28 and 56 days in the rat subcutis.
Materials
Forty-eight young (approx. 200 gm) female Long-Evans (Blue Spruce Farms) rats.
Test Material
One lot each of sizes 2-0 and 5-0 sterile silk, coated as follows:
A. Standard Wax Coating
B. Polymer (P) Coating
Eight strands 18 inches each are used for each coating group.
Methods
Eight 18 inch strands of each coating type are divided into four groups of eight segments each. One segment from each of the strands is placed into each of three implanted groups (7, 28, 56 days) and one unimplanted (0 day) group. Each segment to be implanted is clamped at each end in a hemostatic forceps.
The rats are prepared for surgery by clipping fur from the dorsal scapular region of the skin. They are anesthetized using METOFANE* and swabbed in the operative area with an antiseptic solution.
A transverse incision approximately 2 cm. long is centered in the shaved area. Two segments of test material are implanted in the posterior dorsal subcutis through this single incision, one left and one right. The wound is closed with stainless steel wound clips.
Sutures are so implanted in four rats for each time period previously listed, thus yielding eight replicate segments/period.
The animals are sacrificed at the designated time periods and suture segments are gently and carefully removed from their respective sites. The recovered segments are stored in prelabeled moist paper towels for subsequent breaking strength testing.
All suture segments for this study are tested on an Instron Universal Testing Unit using the following machine parameters:
______________________________________Jaw Face: Coplanar rubber faced steelGage Length: 1 inchCrosshead distraction rate: 2 inches/minuteChart speed: 2 inches/minuteJaw Pressure: 70 PSIBaseline day sample condition: Dry______________________________________ *Trademark of PitmanMoore
Data Handling
The results of the breaking strength tests are summarized for each sample lot as follows:
Averages
Standard Deviation
95% upper and lower confidence limits
Conversion of all numbers to kilograms
Calculation of percent remaining of baseline
These data are listed for each time period including baseline.
Results
Biological response, tensile strength loss and other physical test data are summarized in Tables 2, 3 and 4.
Discussion
The cellular responses to all the tested suture samples are foreign body in nature. However, the polymer (P) treated silk is extremely inert, provoking minimal to very slight tissue reaction scores and preventing cellular ingrowth inside the silk braid.
Oil Red 0 stained cross sections reveal that the polymer is infiltrated throughout the braid. In the case of the size 2-0 material, distribution of polymer tends to be higher in the peripheral carriers than in the central core. The extent of the polymer infiltration is similar after the 7, 28 and 56 day implantation periods, and comparable to the non-implanted suture cross sections.
The silk filaments of the polymer (P) treated samples have a less intense black coloration than the beeswaxed (control) silk filaments, but this can only be seen in the cross-sections and is not apparent grossly.
The waxed silk elicits a moderate tissue reaction. The primary cell types seen in these reaction zones are macrophages, multinucleated foreign body giant cells and fibro blasts. Individual filaments or bundles of filaments of the waxed silk sutures are separated and surrounded by inflammatory cells.
The cross-sectional areas of the waxed controls show considerable cell infiltration and consequent "explosions" of the silk braid.
After four and eight week implantation periods the polymer (P) treated silk exhibits increasingly greater strength retention compared with beeswaxed controls.
Infiltration of braided silk with the polymer (P) results in a tissue-inert silk suture with an excellent "silk hand" and an improved strength retention. Both tissue inertness and in vivo strength retention are rated significantly better than standard silk controls.
A further study, similar to the above is conducted utilizing 36 female Long Evans rats, rather than Sprague Dawley rats, and the results are summarized in Tables 5, 6, 7 and 8. Table 5 sets forth Average Breaking Strength values for polymer (P) coated Sutures after subcutaneous implantation in rats, whereas Tables 6, 7 and 8 relate to tissue response evaluation.
Results
The reactions elicited by the sutures are foreign body in nature. In implant sites of Polymer (P) sutures the reactions are primarily confined to the periphery of the suture. The reactions consist mostly of fibroblastic/fibrocytic cells and macrophages on the suture surface. Other inflammatory cells are absent or present in minimal numbers. Neutrophilic leukocytes are prominent in implant sites of wax coated sutures especially at seven days post implantation. Giant cell and fibroblast/fibrocyte cellular reaction are dominant in the 28 and 56 day waxed suture implant sites.
Fibrous encapsulation of Polymer (P) sutures is well-defined at 56 days while encapsulation of wax coated sutures is poorly defined at the interval.
With respect to overall reactions elicited by size 2-0 sutures, it is noted that Polymer (P) coated sutures tend to evoke less tissue reaction than wax coated silk at seven days post-implantation (see Table 6).
The areas of reaction zones for sizes 2-0 and 5-0 Polymer (P) coated sutures are significantly smaller than are observed for the control samples at 7, 28 and 56 days (see Table 7). The smaller tissue reaction areas observed for Polymer (P) coated sutures are due mainly to lesser amounts of interfibrillar cellular infiltration.
Polymer (P) coating is highly effective in preventing cellular invasion of both sizes of silk sutures at all three periods (7, 28 and 56 days) as shown in Table 8.
In hematoxylin and eosin stain sections of implant sites of paraffin/beeswax, coatings are not visible due to their solubility in histoprocessing solutions. Polymer (P) coating is faintly visible in ordinary transmitted light and is readily seen in polarized transmitted light. Sections of Polymer (P) coated suture sites stained with oil red 0 reveal the coating to be uniformly distributed at the periphery of the suture and variably dispersed around filaments near the center of the suture.
TABLE 2__________________________________________________________________________Biological Response and Physical Test Data for Polymer (P) andBeeswax Paraffin Coated Sutures after Implantation in Sprague-DawleyRats Area of Suture Tissue Reaction Cellular & Tissue Reaction Tensile Strength Period Score Tissue Reaction Invasion % in Square mm. in Kg. RemainingSize 2/0 Days -x σ Median & Range -x of % σ -x σ -x σ %__________________________________________________________________________Polymer (P) 0 -- -- -- -- -- -- -- -- 3.89 0.11 100.0 UCL 3.98 LCL 3.80 7 14.75 5.2 14 (8-21) 9.58 6.2 .301 .13 2.20 .08 56.6 UCL 2.27 LCL 2.13Dry Day O T.S. -x 3.89 kg. σ.11 28 10.75 3.0 10 (5-18) 5.00 5.2 .215 .04 1.92 .12 49.4 UCL 2.02 LCL 1.82*UCL 3.98 56 10.58 3.7 10 (5-17) 2.92 7.2 .183 .03 1.55 .12 39.9LCL 3.80 UCL 1.65 LCL 1.45Beeswax 0 -- -- -- -- -- -- -- -- 4.01 .05 100.0Paraffin UCL 4.05Control LCL 3.97 7 34.08 5.9 35.5 (23-41) 66.67 3.08 .853 .51 2.31 .06 57.6 UCL 2.36 LCL 2.26Dry Day 0 T.S. -x 4.01 kg. σ.05 28 33.42 1.8 33.5 (31-36) 100.00 0 .448 .11 1.52 .20 37.9 UCL 1.69 LCL 1.35UCL 4.05 56 28.83 3.6 28.5 (24-37) 100.00 0 .418 .15 0.84 .19 20.9LCL 3.97 UCL 1.00 LCL .68__________________________________________________________________________ *UCL 95% Upper Confidence Level LCL 95% Lower Confidence Level
TABLE 3__________________________________________________________________________Biological Response and Physical Test Data for Polymer (P) andBeeswax Paraffin Coated Sutures after Implantation in Sprague DawleyRats Area of Suture Tissue Reaction Cellular & Tissue Reaction Tensile Strength Period Score Tissue Reaction Invasion % in Square mm. in Kg. RemainingSize 5/0 Days -x σ Median & Range -x of % σ -x σ -x σ %__________________________________________________________________________Polymer (P) 0 -- -- -- -- -- -- -- -- 0.78 .06 100.0 UCL .83 LCL .73 7 11.75 2.1 11 (10-16) 2.50 4.5 .051 .01 .46 .03 58.9 UCL .49 LCL .43Dry Day 0 T.S. -x .78 kg. σ.06 28 10.90 1.5 10 (10-13) 3.18 4.1 .040 .01 .36 .03 46.2 UCL .39 LCL .33*UCL .83 56 11.58 1.8 11 (10-15) 1.67 2.5 .043 .01 .25 .03 32.1LCL .73 UCL .27 LCL .23Beeswax 0 -- -- -- -- -- -- -- -- .89 .02 100.0Paraffin UCL .91Control LCL .87 7 30.33 6.7 29 (22-47) 97.90 7.2 .303 .22 .54 .01 60.7 UCL .55 LCL .53Dry Day 0 T.S. -x .89 kg. σ.02 28 21.00 3.3 20.5 (17-26) 89.58 16.7 .109 .04 .34 .02 38.2 UCL .36 LCL .32UCL .91 56 21.50 4.0 20.0 (17-29) 85.42 12.9 .105 .06 .24 .05 26.9LCL .87 UCL .28 LCL .19__________________________________________________________________________ *UCL 95% Upper Confidence Level LCL 95% Lower Confidence Level
TABLE 4______________________________________Physical Test Data for Non-Implanted Untreated Silk aswell as Polymer (P) and Beeswax Paraffin Coated Sutures Straight Tensile Dry Knot Strength Diameter Pulls Kg. (kg) in mm. -x σ -x σ -x σ______________________________________2/0*Polymer (P) 2.18 .13 3.89 .11 .340 .013Beeswax Paraffin Control 2.18 .09 4.01 .05 .295 .018Untreated Silk of Same 2.63 .15 4.06 .03 .306 .006Original Lot5/0* -Polymer (P) .50 .04 .78 .06 .125 .005Beeswax Paraffin Control .52 .04 .89 .02 .127 .005Untreated Silk of Same .56 .04 .78 .10 .130 .003Original Lot______________________________________ *All measurements after CO Sterilization
TABLE 5______________________________________AVERAGE BREAKING STRENGTH VALUESFOR POLYMER (P) SUTURESAFTER SUBCUTANEOUS IMPLANTATIONIN LONG EVANS RATSDATA EXPRESSED IN POUNDS TIME IN DAYS 0 7 28 56 DESCRIPTIONS______________________________________SIZE: 2-0 8.60 5.00 4.27 3.02 PARAFFIN/% REMAINING 100 58 50 35 BEESWAXSIZE: 2-0 8.31 5.13 4.37 3.88 POLYMER (P)% REMAINING 100 62 53 47 COATEDSIZE: 5-0 1.82 1.17 0.88 0.68 PARAFFIN/% REMAINING 100 64 49 37 BEESWAXSIZE: 5-0 1.65 0.99 0.79 0.74 POLYMER (P)% REMAINING 100 60 48 45 COATED______________________________________
TABLE 6______________________________________MEDIAN TISSUE OVERALL REACTIONSCORES FOR COATEDSILK SUTURES AFTER INTRAMUSCULARIMPLANTATION IN LONG EVANS RATS* DAYS POST-IMPLANTATIONSIZE DESCRIPTION 7 28 56______________________________________2-0 Polymer (P) Coated 14.5 8 11 (8-17) (6-14) (7-14)2-0 Paraffin/Beeswax 38.5 31 25.5 Coated (13-42) (17-52) (15-40)5-0 Polymer (P) Coated 16 7.5 10.5 (13-23) (5-15) (8-14)5-0 Paraffin/Beeswax 26 17 16 Coated (20-30) (14-34) (15-23)______________________________________ *Data represent the median of 10-12 cross section in three rats per period. Arbitrary assignment of scores are as follows: 1-8 minimal, 9-24 slight, 25-40 moderate, 41-56 marked, 56+ extensive. ** ( ) = range of tissue reaction scores for the period.
TABLE 7______________________________________AVERAGE TISSUE REACTION AREASFOR COATED SILK SUTURESAFTER INTRAMUSCULAR IMPLANTATIONIN LONG EVANS RATS* DAYS POST-IMPLANTATIONSIZE DESCRIPTION 7 28 56______________________________________2-0 Polymer (P) Coated .204 .196 .170 (.026) (.026) (.030)2-0 Paraffin/Beeswax .857 .768 .539 Coated (.200) (.415) (.331)5-0 Polymer (P) Coated .112 .049 .053 (.036) (.009) (.013)5-0 Paraffin/Beeswax .280 .161 .143 Coated (.074) (.040) (.041)______________________________________ *Data represent the mean of 10-12 cross sections per period and are presented in square millimeters (mm.sup.2). **( ) = Standard deviation.
TABLE 8______________________________________DEGREE OF INTERFIBRILLAR CELLULARINFILTRATION INTOCOATED SILK SUTURES AFTERINTRAMUSCULAR IMPLANTATIONIN LONG EVANS RATS* DAYS POST-IMPLANTATIONSIZE DESCRIPTION 7 28 56______________________________________2-0 Polymer (P) Coated 0.6** 0.7 0.92-0 Paraffin/Beeswax 4.0 3.8 3.8 Coated5-0 Polymer (P) Coated 0.5 0.7 0.85-0 Paraffin/Beeswax 3.9 3.9 4.0 Coated______________________________________ *Data represent the average of 10-12 cross sections per period. **Arbitrary assignment of scores is as follows: 0 = no infiltration 1 = slight infiltration 2 = moderate infiltration 3 = marked infiltration 4 = complete infiltration
EXAMPLE 1
Polymer (P) Poly[tetramethylene terephthalate-Co-Poly(oxytetramethylene terephthalate)](25/75 PBT/POTM-T)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________27.9 g 1,4 dimethyl terephthalate (0.1439 mol)24.6 g 1,4 butanediol (0.2730 mol)53.1 g (Poly tetramethylene oxide diol). (0.0531 mol) (Molecular Weight 1000 Dalton)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitante (0.244 g) and magnesium acetate (0.01 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 2.5 hours, 220° C. for 2.5 hours.
As the distillation of volatile by-products slows, after 2.5 hours at 220° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 230° C. for 4.5 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
EXAMPLE 2
Polymer (P) Poly[tetramethylene terephthalate-Co-Poly-(oxytetramethylene terephthalate)](29/71 PBT/POTM-T)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 500 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________38.8 g 1,4 dimethyl terephthalate (0.1998 mol)37.7 g 1,4 butanediol (0.4183 mol)65.4 g (Poly tetramethylene oxide diol) (0.0654 mol) Molecular Weight 1000 Dalton0.0331 g dibutyl tin oxide (0.000133 mol)______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 3.0 hours, 230° C. for 4.0 hours.
As the distillation of volatile by-products slows, after 4.0 hours at 230° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 230° C. for 6.0 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
______________________________________Analytical Data: Tm (microscopy) 140°-150° C. I.V. (in HFIP) 1.2______________________________________
EXAMPLE 3
Polymer (P) Poly[tetramethylene terephthalate-Co-Poly(oxytetramethylene terephthalate)](45/55 PBT/POTM-T)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________39.3 g 1,4 dimethyl terephthalate (0.2024 mol)44.1 g 1,4 butanediol (0.4893 mol)38.9 g (Poly tetramethylene oxide diol) (0.0389 mol) Molecular Weight 1000 Dalton0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.244 g) and magnesium acetate (0.01 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 2.0 hours, 220° C. for 2.5 hours.
As the distillation of volatile by-products slows, after 2.5 hours at 220° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 230° C. for 3.5 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
EXAMPLE 4
Polymer (R) Poly[tetramethylene terephthalate-Co-(2-octadecenyl)succinate](40/60 PBT/C 18 succinate)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________28.2 g 1,4 dimethyl terephthalate (0.1453 mol)39.8 g 2-octadecenyl succinic anhydride (0.1136 mol)69.9 g 1,4 butanediol (0.7756 mol)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.244 g) and magnesium acetate (0.01 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 3.0 hours, 220° C. for 3.0 hours.
As the distillation of volatile by-products slows, after 3.0 hours at 220° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 240° C. for 2.0 hours, 250° C. for 2.0 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
______________________________________Analytical Data: Tm (microscopy) 113°-118° C. I.V. (in HFIP) 0.46______________________________________
EXAMPLE 5
Polymer (S) Poly[poly(tetramethylene oxybenzoate)-Co-poly(hexamethylene-2-octadecenyl succinate)](40/60 PBB/C 18 succinate)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________37.3 g methyl para(4-hydroxy butoxy)benzoate (0.1666 mol)37.3 g 2-octadecenyl succinic anhydride (0.1065 mol)13.9 g 1,6 hexanediol (0.1176 mol)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 100° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 100° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.305 g) and magnesium acetate (0.0125 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 2.5 hours, 220° C. for 3.0 hours, 240° C. for 2.25 hours.
As the distillation of volatile by-products slows, after 2.25 hours at 240° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 240° C. for 2.5 hours, 250° C. for 2.75 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
Analytical Data: Tm(microscopy) 50°-70° C.
EXAMPLE 6
Polymer (S) Poly[poly(tetramethylene oxybenzoate)-Co-poly(hexamethylene-2-octadecenyl succinate)](50/50 PBB/C 18 succinate)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________46.7 g methyl para(4-hydroxy butoxy)benzoate (0.2082 mol)31.1 g 2-octadecenyl succinic anhydride (0.0888 mol)11.6 g 1,6 hexanediol (0.0981 mol)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 100° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 100° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.305 g) and magnesium acetate (0.0125 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 3.0 hours, 220° C. for 2.3 hours, and 240° C. for 1.25 hours.
As the distillation of volatile by-products slows, after 1.25 hours at 240° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 240° C. for 4.5 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
______________________________________Analytical Data: Tm (microscopy) 98°-101° C. I.V. (in HFIP) 0.38______________________________________
EXAMPLE 7
Polymer (Q) Poly[tetramethylene terephthalate-Co-dimerate](30/70 PBT/dimerate)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________21.2 g 1,4 dimethyl terephthalate (0.1090 mol)58.7 g diisopropyl dimerate (0.0903 mol)53.7 g 1,4 butanediol (0.5959 mol)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.244 g) and magnesium acetate (0.01 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 2.0 hours, 220° C. for 2.5 hours.
As the distillation of volatile by-products slows, after 2.5 hours at 220° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 240° C. for 3.5 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
______________________________________Analytical Data: Tm (microscopy) 151°-156° C. I.V. (in HFIP) 0.36______________________________________
EXAMPLE 8
Polymer (Q) Poly[tetramethylene terephthalate-Co-dimerate](40/60 PBT/dimerate)
Under a dry nitrogen atmosphere, the following materials are placed into a flame and vacuum dried 300 ml two-neck, round-bottom flask equipped with a stainless steel paddle stirrer, a short distilling head fitting with a receiver, and a gas inlet nozzle:
______________________________________28.2 g 1,4 dimethyl terephthalate (0.1453 mol)50.3 g diisopropyl dimerate (0.0774 mol)60.3 g 1,4 butanediol (0.6691 mol)0.16 g Irganox 1098______________________________________
After stoppering the open neck of the flask, the entire charge-containing assembly is removed from the nitrogen atmosphere and exposed to a high (less than 1 mm) vacuum for several hours. The charged reaction vessel is then vented with nitrogen, and the reactants are melted by heating to 165° C. Once the charge is liquified, the reaction flask is connected to an efficient mechanical stirrer and thorough mixing at 165° C. is performed for 15 minutes. Next, the catalyst consisting of a mixture of tetrabutyl orthotitanate (0.244 g) and magnesium acetate (0.01 g) dissolved in a mixture of methanol and butanol, is quickly syringed into the reaction vessel via the side arm. Still under a continuous flow of nitrogen, the melted reaction mixture is then subjected to the following heating sequence: 190° C. for 2.5 hours, 220° C. for 3.0 hours.
As the distillation of volatile by-products slows, after 3.0 hours at 220° C., the receiver containing the distillate is replaced with an empty receiver. Then, gradually over the course of 0.75 hours the pressure in the reaction flask is reduced to 0.05 mm. Under reduced pressure the reaction mixture is subjected to the following heating scheme: 240° C. for 2.0 hours.
At the end of this heating cycle, the reaction vessel is removed from the oil bath, equilibrated with nitrogen, and then allowed to cool to room temperature. The polymer is isolated after chilling in liquid nitrogen, ground, and then dried under vacuum.
______________________________________Analytical Data: Tm (microscopy) 148°-151° C. I.V. (in HFIP) 0.23______________________________________
EXAMPLE 9
Impregnation of Silk Suture with Polymer
The laboratory coating line consists of the conventional spool let-off, solution treatment, drying the suture takeup operations, arranged sequentially. Two black dyed silk sutures, sizes 2-0 and 5-0 are treated. The suture material is passed through a 15-20% w/v solution of polymer (P) prepared in accordance with Example 2 in dichlormethane, maintained at 40°±5° C.
On emerging from the polymer solution, excess solution is removed by passage through a felt wipe. Solvent is evaporated by running the sutures past a hot air blower (150° C.).
Both polymer solution temperature and concentration are important in achieving the desired polymer add-on in a single pass. Desirable polymer add-on is in the 7-15% range, with a value of 9% for size 2-0 and 12% for size 5-0.
At this stage of the process, the polymer encapsulates the suture and does not appreciably penetrate the interior of the braid. The hand of this material is very stiff. Desirable suture properties of hand and knot-tying are achieved by causing the polymer to infiltrate and penetrate the interior of the braid by subjecting the polymer sheathed suture to a short duration, high temperature heating stage.
The polymer sheathed suture is passed in a vertical mode centrally through a 0.5 cm diameter hole bored in a 22 cm electrically heated aluminum block. Conditions of block temperature and suture speed for achieving optimum infiltration are given below:
______________________________________Suture Size Block Temperature Suture Speed______________________________________2-0 415 ± 5° C. 7.1 cm/sec5-0 345 ± 5° C. 9.6 cm/sec______________________________________
The above conditions are found to confer a soft, supple hand, as contrasted to the stiff, wiry hand of the encapsulated suture.
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Composite suture of multifilament silk embedded in a highly flexible, hydrophobic highly deformable matrix made of thermoplastic elastomer. This suture exhibits minimal irritation to living tissue and retains its strength in vivo for extended periods of time and also retains the desirable handling qualities of silk. The suture is prepared by treating a multifilament silk suture with a solution of a suitable polymer in a solvent and heating the moving suture to obtain a continuous impregnation of the silk with the elastomer.
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BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates generally to telescoping bleacher assemblies, and more particularly to an automatic end closure system for utilization in conjunction with telescoping bleacher assemblies as an add-on or integrated component.
2) Description of the Related Art
Telescoping bleacher assemblies are widely used in gymnasiums, sports arenas and other similar facilities throughout the country. The telescoping bleacher assembly is extended from a retracted position to an extended position to provide seating for an event. When the seating is no longer needed, the bleacher is retracted to allow for a greater open space in the gymnasium or arena. The space saving feature of these telescoping bleacher assemblies make them ideal for gymnasiums and arenas where the seating needs change depending on the event. However, when the telescoping bleacher assembly is extended, the undersection of the bleacher is exposed to the public. In the past, such exposed undersections might not have posed a problem to the owners and operators of such facilities. However in this day and age of the aggressive sports fan, negligent parents who become too involved in the event and pay little attention to their children, and the ever increasing number of destructive juvenile delinquents, owners and operators see exposed undersections as sites of potential liability or mischievous activity.
The undersection may contain various hazards depending on the type of telescoping bleacher assembly. If the bleacher assembly is one that automatically extends and retracts then the drive mechanism is open to intruders who may vandalize the mechanism. If the bleacher assembly is extended and retracted by tractor then intruders might still wreak havoc on the understructure of the bleacher assembly. There is also the possibility of children or adults who may stray into the undersection of the bleacher assembly and cause harm to themselves including the possibility of being enclosed in the undersection when the bleacher assembly is retracted after an event. In addition to the "common" type of misbehavior, increased terrorism from foreign and domestic sources make exposed undersections tempting targets for concealing explosive devices. Therefore, the potential liability due to exposed undersections of telescoping bleacher assemblies is tremendous.
The prior art has failed to address this potential liability arising from an exposed undersection of a telescoping bleacher assembly. Instead, the prior art has focused its attention on improving safety for the uppersection of telescoping bleacher assemblies by inventing various guard rails for attachment to or integration into the bleacher assemblies. The guard rails are often attached to the seats of the bleacher assembly in order to prevent well-behaved spectators from accidentally falling off the end of the bleacher assembly. However, what is equally needed is an apparatus for protecting the undersection of the bleacher assembly from mischievous or curious spectators. Unlike the uppersection where identical guard rails units may be used, protecting the undersection requires matching the protective units to the descending height of each forward row of seats. This also requires a guiding system which would not interfere with the extension and retraction of the bleacher assembly. Also, substantially the entire end of the bleacher assembly must be substantially covered which requires a moveable apparatus of greater weight and complexity than the guard rail units of the uppersection. At the same time such factors cannot be detrimental to the easy extension and retraction of the bleacher assembly.
It therefore will be appreciated by those in the pertinent art that there has been a substantial need for enclosing the undersection of the telescoping bleacher assembly without deterring from the telescoping feature of the bleacher assembly. The present invention fulfills this need and provides other related advantages.
SUMMARY OF THE INVENTION
The present invention provides the necessary protection of the undersection of telescoping bleacher assemblies while not deterring from the easy extension and retraction of such bleacher assemblies. The present invention meets the needs of the pertinent art by providing an automatic end closure system for preventing ingress and egress of the undersection of telescoping bleacher assemblies. The present invention also provides an apparatus which is an add-on or integrated component to telescoping bleacher assemblies.
In its most basic form, the automatic end closure system of the present invention comprises a plurality of panels attached to the telescoping bleacher assembly, a plurality of top guidance tracks attached to each panel of the plurality of panels for guiding the plurality of panels during extension and retraction of the telescoping bleacher assembly, a plurality of bottom guidance tracks attached to each panel of the plurality of panels for also guiding the plurality of panels during extension and retraction of the telescoping bleacher assembly, and wheels connected to each panel of the plurality of panels for undersupporting the same.
The automatic end closure system further may comprise a means for anchoring the automatic end closure system to a stationary support such as a wall. The automatic end closure system further may comprise a plurality of panel locking engagements integrated into each track of the plurality of top guidance tracks and each track of the plurality of bottom guidance tracks. Also, each of the bottom and top guidance tracks are composed of an upper arm and a lower rail with the upper arm on one panel and the lower rail on a neighboring panel. In this design, the top and bottom guidance tracks connect each of the panels to each other in a non-interfering manner. The automatic end closure system still further may comprise means for attaching the plurality of panels to the frame of the telescoping bleacher assembly for automatic movement of the automatic end closure system with the movement of the telescoping bleacher assembly.
In alternative embodiment, the automatic end closure system of the present invention is integrated into the telescoping bleacher assembly. In this embodiment, the telescoping bleacher assembly comprises a plurality of rows of seats and foot decks supported on a series of moveable flames, and an automatic end closure structure. The plurality of rows of seats and foot decks are capable of extending forward to an extended state where the plurality of rows of seats and foot decks are in descending spaced relation to each other. The plurality of rows of seats and foot decks are also capable of retracting rearward to a retraction state where the rows are superimposed upon each other in a vertical column. The automatic end closure structure includes a plurality of panels attached to the frame of the bleacher assembly, a plurality of top guidance tracks attached to each panel of the plurality of panels, a plurality of bottom guidance tracks attached to each panel of the plurality of panels for moveably undersupporting the same, and means for anchoring the automatic end closure structure to a stationary support.
The telescoping bleacher assembly of this embodiment further may comprise a plurality of panel locking engagements integrated into each track of the top guidance tracks and each track of the bottom guidance tracks. Also in this embodiment, each of the bottom and top guidance tracks are composed of an upper arm and a lower rail with the upper arm on one panel and the lower rail on a neighboring panel. In this design, the top and bottom guidance tracks connect the panels to each other in a non-interfering manner.
In a more detailed embodiment of the present invention, the automatic end closure system is connected to a telescoping bleacher assembly which extends and retracts. The bleacher -assembly has an undersection exposed on at least one end and a plurality of rows of seats and foot decks supported on cantilever flames. In the extended state, the plurality of rows of seats and foot decks are extended forward and are spaced in descending relation to each other. In the retracted state, the plurality of rows of seats and foot decks are retracted rearward and are superimposed upon each other in a vertical column. The automatic end closure system comprises a plurality of panels for substantially preventing ingress and egress to the undersection of the bleacher assembly. Each panel of the plurality of panels corresponds in height to the vertical distance from the floor to the foot deck of the bleacher assembly above the panel, and correspond in length to two rows of seats of the bleacher assembly. A rear most panel is anchored to a stationary support such as a wall. The automatic end closure system also comprises a plurality of top guidance tracks attached to the upper region of each panel of the plurality of panels for interconnecting the plurality of panels to one another and for latitudinally slidably guiding the plurality of panels during extension and retraction of the bleacher assembly. The automatic end closure system in this embodiment also comprises a plurality of bottom guidance tracks attached to the lower region of each panel of the plurality of panels for interconnecting the plurality of panels to one another and for latitudinally slidably guiding the plurality of panels during extension and retraction of the bleacher assembly. The automatic end closure system also comprises wheels connected to the bottom of each panel of the plurality of panels for moveably undersupporting the same and a plurality of panel locking engagements integrated into each track of the plurality of top guidance tracks and bottom guidance tracks for preventing disconnection of the plurality of panels during extension and retraction and for maintaining the integrity of the automatic end closure system.
The automatic end closure system in this embodiment has each track of the plurality of guidance tracks consisting of an upper arm connected to one of the plurality of panels and a lower rail connected to an adjacent panel. The upper arm overlaps the lower rail thereby interconnecting succeeding panels from rearward to forward. During extension of the automatic end closure system the most forward panel is extended until the panel locking engagement engages an immediately rearward panel for extension thereof in a like manner. The progression of panels continues in this manner until all of the plurality of panels are fully extended.
In a very specific embodiment of the present invention, the automatic end closure system includes five panels of increasing height at opposite ends of the telescoping bleacher assembly. It being recognized that the number of panels will vary depending on the number and size of the bleacher sections to be covered by the automatic end closure system. In another specific embodiment, the plurality of panels are composed of an inner metal frame substantially covered with a wooden facade.
It is an object of the present invention to provide an automatic end closure system for blocking ingress and egress to the exposed undersection of a telescoping bleacher assembly.
It is a further object of the present invention to provide an apparatus which increases the safety of a telescoping bleacher assembly.
It is a further object of the present invention to provide an apparatus to decrease the potential liability of a telescoping bleacher assembly.
It is a further object of the present invention to provide an apparatus for protecting the drive motor and related mechanisms of the telescoping bleacher assembly.
Having briefly described this invention, the above and further objects, features and advantages thereof will be recognized by those of skill in this art from the following detailed description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in connection with the accompanying drawings, in which:
FIG. 1 is a side perspective of a typical telescoping bleacher assembly in the extended state.
FIG. 2 is a side perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the extended state.
FIG. 3 is a top perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the extended state.
FIG. 4 is a top perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the retracted state.
FIG. 5 is a front perspective cross section of two panels of the present invention connected to each other in order to illustrate the preferred embodiment of the guidance tracks of the present invention.
FIG. 6 is a top perspective of the panel locking engagements of the present invention.
FIG. 7 is a front perspective of the present invention connected to a telescoping bleacher assembly in a retracted state which also illustrates an alternative embodiment of the bottom guidance track of the present invention.
FIG. 8 is a front perspective of a panel of the present invention without a top or bottom guidance track.
FIG. 9 is a side perspective of a panel of the present invention without a top or bottom guidance track.
FIG. 10 is a front perspective of the wheel mechanism of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
There is illustrated in FIG. 1 a side perspective of a typical telescoping bleacher assembly in the extended state. There is illustrated in FIG. 2 a side perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the extended state. The automatic end closure system 12 of this invention is therein shown in FIG. 2 installed with a multi-tiered telescoping bleacher assembly, indicated generally at 14. Multi-tiered telescoping bleacher assembly 14 is composed of a frame 18, a guard rail 19, a plurality of rows of seats 20, a plurality of rows of foot decks 22, a plurality of front risers 24 and a plurality of rear risers 26.
In FIGS. 1 and 2, the bleacher assembly 14 is in its extended or open state in which all of the plurality of rows of seats 20 and their corresponding plurality of rows of foot decks 22, except the stationary top most row of seats 20 and its corresponding row of foot deck 22, are moved successively outwardly (bottom to top) to provide the familiar tiered bleacher seating. Once extended, the undersection 27 of the bleacher assembly 14 is exposed and open to spectators at the event. The undersection 27, as shown in FIG. 1, may contain the drive motor 29 and related mechanism for automatically extending and retracting the bleacher assembly 14. The undersection 27 also contains the frame 18 which supports the bleacher assembly 14. Thus, the undersection 27 of the bleacher assembly 14 provides a tempting target for mischievous and curious spectators at the event which increases the potential liability to the facility. It will be understood that this invention is particularly directed to preventing the ingress and egress to the undersection 27 of the bleacher assembly 14 and thereby providing a safer environment which is substantially vandal-free.
The automatic end closure system 12 consists of a plurality of generally planar panels designated 32, 34, 36, 38 and 40. The number of panels will vary depending on the number and size of the bleacher sections to be covered by the automatic end closure system 12. FIG. 2 illustrate only five panels however the present invention may consists often panels for a larger bleacher assembly, twenty panels for a still larger bleacher assembly, and so on for any size of bleacher assembly. The most rearward panel 40 is a stationary panel and is anchored to a stationary support 16 which is usually a vertical wall. The means for attaching the stationary panel 40 to the stationary support 16 is preferably a "L" shaped plate 44 bolted to the panel 40 and the support 16. In one embodiment, the plurality of panels 32-38 are designed to match the height of the corresponding foot deck 22 of the bleacher assembly 14 with the panels 32-38 rearwardly becoming progressively taller with the stationary panel 40 the tallest. The height of each panel of the plurality of panels 32-38 corresponds to the vertical distance from substantially the floor to the row of foot decks 22 which is directly above the panel 32-38. In the preferred embodiment, each panel of the plurality of panels 32-38 corresponds to two rows of seats 20. In this embodiment, the height of each panel of the plurality of panels 32-38 generally will match the height of the most rearward of the associated two rows of seats 20. If the height of the plurality of panels 32-38 is descending rearward to forward in a continual manner as illustrated in FIG. 2, then the height of each panel of the plurality of panels 32-38 descends from a high point near the midpoint of the rearward row of foot decks 22 to near the midpoint of the associated forward row of foot decks 22. In an alternative embodiment, the length of each panel 32-38 corresponds to the length of a single row of seats 20, from front riser 24 to rear riser 26.
In the preferred embodiment, the plurality of panels 32-38 are designed to automatically extend forward and retract rearward with the movement of the bleacher assembly 14. The extension or retraction of the automatic end closure system 12 is accomplished with the assistance of wheels 42 connected to the bottom of each panel of the plurality of panels 32-38. Wheels 42 also provide independent moveably undersupport for the automatic end closure system 12.
Specifically referring to the embodiment illustrated FIG. 2, the plurality of panels 32-40 have a plurality of portholes 43 therethrough to allow for viewing of the undersection 27 when the bleacher assembly 14 is in its extended slate. The plurality of portholes 43 are selectively positioned among the plurality of panels 32-40 to allow for the greatest viewing of the undersection 27 without deterring from the ability of the automatic end closure system 12 to prevent ingress and egress to the undersection 27 of the bleacher assembly 14. In FIG. 2, the plurality of portholes 43 are circular in shape. However the shape of the portholes 43 could be non-circular shapes including but not limited to square, hexagonal, octagonal and the like.
There is illustrated in FIG. 3 a top perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the extended state. As shown in FIG. 3, the automatic end closure system 12 is connected to the bleacher assembly 14 by a plurality of frame connectors 46. In the preferred embodiment, frame connectors 46 are connected to each panel of the plurality of panels 32-38 and to the frame 18 of the bleacher assembly 14 at two row intervals. When connected in this manner, end closure 12 automatically extends and retracts with the movement of bleacher assembly 14.
The automatic end closure system 12 is designed such that the plurality of panels 32-38 are slidable forward and forward in a non-interfering manner with each other panel. In this design, the plurality of panels 32-38 have individual movement paths which are parallel to each other. However, this design allows for a rearward increasing chasm 47 as each succeeding rearward panel 32-40 is a greater lateral distance away from the bleacher assembly 14 than the proceeding panel 32-40. It is anticipated that uppersection guard rails 19 would prevent access to the undersection 27 through this chasm 47. In the alternative, a foam cushion piece or the like may be used to cover the chasm 47.
There is illustrated in FIG. 4 a top perspective of the preferred embodiment of the present invention connected to a telescoping bleacher assembly in the retracted state. As shown in FIG. 4, the automatic end closure system 12 in the retracted state has the plurality of panels 32-40 horizontally juxtaposed to each other. In this design, the automatic end closure system 12 does not substantially increase the amount of a space occupied by the bleacher assembly 14 thereby conserving space when not in use for an event. The automatic end closure system 12 also substantially prevents ingress and egress to the undersection 27 when the bleacher assembly 14 is in its retracted state.
There is illustrated in FIG. 5 a front perspective cross section of two panels 38 and 40 of the present invention connected to each other in order to illustrate the preferred embodiment of the guidance tracks of the present invention. There is illustrated in FIG. 7 a front perspective of the present invention connected to a telescoping bleacher assembly in a retracted state which also illustrates an alternative embodiment of the bottom guidance track of the present invention. As shown in FIG. 5, the top guidance tracks are generally designated 48 and the bottom guidance tracks are generally designated 50. Both guidance tracks 48 and 50 provide means for slidably connecting the plurality of panels 32-40 to each other. Each panel of the plurality of panels 32-40 has a top guidance track 48 and a bottom guidance track 50.
Each track of the plurality of top guidance tracks 48 is composed of an upper arm 52 and a lower rail 54. For each top guidance track 48, an upper arm 52 is connected to one of the plurality of panels 32-40 and the lower rail 54 is connected to the neighboring panel 32-40. Thus, on a single panel, for example panel 34, the lower rail 54 is on one side of the panel 34 while the upper arm 52 is on the opposite side, with the upper arm 52 and the lower rail 54 corresponding to two separate top guidance tracks 48. The plurality of top guidance tracks 48 are generally located in the top end region of the sides of the plurality of panels 32-40. The plurality of bottom guidance tracks 50 are generally located in the bottom end region of the sides of the plurality of panels 32-40. However it will be appreciated by those skilled in the pertinent art that the plurality of guidance tracks 48 and 50 may be positioned at any region along the sides of the plurality of panels 32-40 as long as the plurality of panels 32-40 are slidably connected in a non-interfering manner and the vertical integrity, of the automatic end closure system 12 is maintained by the plurality of guidance tracks 48 and 50.
Each track of the plurality of bottom guidance tracks 50 is composed of an upper arm 56 and a lower rail 58. In the preferred embodiment, the bottom guidance track 50 is a one piece metal track having an upside-down "U" shaped section which forms the upper arm 56 at its rearward end, a flat base attached to the bottom of each of the plurality of panels 32-38 and an upwardly projecting section on the opposite side of the "U" shaped section which forms the lower rail 58. In an alternative embodiment, the upper arm 56 is a separate piece from the lower rail 58 as shown in FIG. 7. In this alternative embodiment, the upper arm 56 is composed of a first straight section connected to a panel 32-38 which at one end becomes a diagonal section which then becomes a second straight section which is itself parallel to the first straight section. This second straight section will overlap the lower rail 58 which is itself a "U" shaped piece connected to the bottom of a panel 32-38.
The lower rails 54 and 58 latitudinally extend along the length of each panel of the plurality of panels 32-40. The upper arms 52 and 56 are positioned substantially near the rearward end of each panel of the plurality of panels 32-40. As shown in FIGS. 5 and 7, the upper arm 52 and the lower rail 54 of the top guidance tracks 48 are positioned to overlap in order to connect the plurality of panels 32-40 to each other. In the preferred embodiment, the upper arms 52 and 56 are bolted to each of their corresponding panels 32-40. However, other methods of connecting the upper arms 52 and 56 to the panels 32-40 are possible including adhesion, indentation, and the like.
Referring specifically to FIG. 7, the horizontal juxtaposition of the plurality of panels 32-40 is better illustrated. The bleacher assembly 14 is in its collapsed or retracted state in which the multi-tiered cantilever supported rows of seats 20 and rows of foot decks 22 are superposed in a vertical stacked relationship. Also, the frame connectors 46 are shown as vertically juxtaposed on each other in the retracted state. This allows the plurality of panels 32-40 to be positioned laterally parallel to each other to conserve space. The frame connectors 46 are connected to panels 32-40 and the frame 18 at two row intervals. However other embodiments might have the frame connectors 46 connected at single row intervals. Still other embodiments might have only one frame connector 46 connected to the most forward panel 32 and the frame 18.
Referring again to FIG. 5, the wheels 42 are connected to each track of the plurality of bottom guidance tracks 50. The wheels 42 provide moveably undersupport for the automatic end closure system 12 independent of the bleacher assembly 14. A plurality of wheel flanges 59 are connected to each track of the plurality of bottom guidance tracks 50, usually at the most forward and rearward positions. The wheels 42 are connected to the wheel flanges 59 by bolts 60.
There is illustrated in FIG. 6 a top perspective of the panel locking engagements of the present invention. The panel locking engagements, generally designated 61, provide means for preventing the disconnection of the plurality of panels 32-40 from each other when the automatic end closure system 12 is being extended and retracted. In the preferred embodiment, the panel locking engagements 61 consists of the lower rail 54 of each track of the plurality of top guidance tracks 48 closed off at one end in order to prevent further movement of the overlapping upper arm 52. The rearward section 62 of each lower rail 54 is bent perpendicular to the rest of the rail 54 in order to prevent the disengagement of the panels 32-40 from each other. A similar design is used for the panel locking engagements of each track of the plurality of bottom guidance tracks 50. In this design, the plurality of panels 32-40 are slidably connected to each other which maintains the integrity of the automatic end closure system 12. It should be well understood by those skilled in the pertinent art that a second panel locking engagement may be placed on the forward end of each of the top and bottom guidance tracks 48 and 50 to provide further stability of the automatic end closure system 12.
There is illustrated in FIG. 8 a front perspective of a panel of the present invention without a top or bottom guidance track. There is illustrated in FIG. 9 a side perspective of a panel of the present invention without a top or bottom guidance track. As shown in FIGS. 8 and 9, the plurality of panels 32-40 are composed of an outer coveting 64 connected to an inner framing 66. In the preferred embodiment, the inner framing 66 is a metal frame providing for support and stability of each panel of the plurality of panels 32-40. The outer covering 64 is preferably composed of a stained wood to provide an aesthetically appealing facade with strength to resist intruders. However in other embodiments, the outer covering 64 of the plurality of panels 32-40 might consist of aluminum, tin, plastics, other woods and the like placed on a metal frame. Whatever the composition of the inner framing 66 and outer covering 64, the plurality of panels 32-40 are created to resist the forcible entry of intruders to the undersection 27 of the bleacher assembly 14.
There is illustrated in FIG. 10 a from perspective of the wheel mechanism of the present invention. As shown in FIG. 10, the wheels 42 are bolted to the wheel flanges 59 which are themselves connected to or part of each track of the plurality of bottom guidance tracks 50. In this embodiment, as better seen in FIG. 9, the weight of each panel of the plurality of panels 32-38 is distributed between two wheels 42, one positioned on the forward end of the panel and one positioned on the rearward end of the panel. Referring again to FIG. 10, the bottom guidance track 50 is shown as a singular piece having not only the upper arm 56 and lower rail 58, but also the wheel flange 59. The bottom guidance track 50 is connected to a panel 32-38 by bolts (not shown), and the wheel flange 59 is connected to the wheel 42 by a bolt 60.
In attaching the automatic end closure system 12 as an add-on component to a telescoping bleacher assembly 14, the bleacher assembly 14 should preferably be in its extended state. Assuming an automatic end closure system 12 consisting of five panels (installing an automatic end closure system 12 consisting of more or less than five panels will proceed in a similar manner), the installation should proceed in the following manner. First the most rearward panel, stationary panel 40, should be connected to the stationary support 16 by the "L" shaped plates 44. Then the next most rearward panel, panel 38, should have its lower rails 54 and 58 engaged with the upper arms 52 and 56 of the stationary panel 40. The panel 38 should be extended to its most forward position thereby engaging its panel locking engagements 61. The panel 38 should then be connected to the frame 18 of the bleacher assembly 14 by a frame connector 46. Then the next most rearward panel, panel 36, should have its lower rails 54 and 58 engaged with the upper arms 52 and 56 of the panel 38. The panel 36 should be extended to its most forward position thereby engaging its panel locking engagements 61. The panel 36 should then be connected to the frame 18 of the bleacher assembly 14 by a frame connector 46. Then the next most rearward panel, panel 34, should have its lower rails 54 and 58 engaged with the upper arms 52 and 56 of the panel 36. The panel 34 should be extended to its most forward position thereby engaging its panel locking engagements 61. The panel 34 should then be connected to the frame 18 of the bleacher assembly 14 by a frame connector 46. Finally, the most forward panel, panel 32, should have its lower rails 54 and 58 engaged with the upper arms 52 and 56 of the panel 34. The panel 32 should be extended to its most forward position thereby engaging its panel locking engagements 61. The panel 32 should then be connected to the frame 18 of the bleacher assembly 14 by a frame connector 46. The bleacher assembly 14 should then be retracted to insure that the automatic end closure system 12 automatically retracts along with the bleacher assembly 14.
From the foregoing it is believed that those skilled in the art will recognize the meritorious advancement of this invention and will readily understand that while the same has been described in association with a preferred embodiment thereof, illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims.
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An automatic end closure system for use in conjunction with a typical telescoping bleacher assembly. The automatic end closure system substantially blocks ingress and egress to the undersection of the telescoping bleacher assembly which prevents mischievous or curious spectators from causing harm to themselves or to the equipment contained in the undersection. The automatic end closure system basically includes a plurality of panels, a plurality of guidance tracks, a plurality of panel locking engagements and wheels. Each of the panels may be composed of an inner metal framing covered with a wooden facade. The automatic end closure system may be an add-on or integrated component of the telescoping bleacher assembly. Once connected to the telescoping bleacher assembly, the automatic end closure system automatically expands and retracts with the expansion and retraction of the telescoping bleacher assembly. When the automatic end closure system is in its retracted state, the plurality of panels rests in horizontal juxtaposition to each other thereby conserving space when not in use for an event.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a U.S. National Stage of International Patent Application No. PCT/EP2014/054531 filed Mar. 10, 2014, and claims priority of Austrian Patent Application No. A50165/2013 filed Mar. 11, 2013.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electrically actuated friction brake with a brake pad actuated by an actuation device, wherein the actuation device is driven by an electrical actuator and comprises a first transmission element that is connected to the brake pad and the actuation device rotates the first transmission element about a rotational angle for a brake action to achieve a pad pressing force and the first transmission element requires an input torque depending on the rotational angle for achieving the pad pressing force.
[0004] The present invention relates to electrically actuated brakes, thus to brakes in which an electrical actuator such as an electric motor, via transmission parts such as levers, screws, ball screws, cams, eccentrics, fluids, gases, etc., presses on the brake pad, such as a brake disc for example, on the friction surface, such as a brake disc or brake drum, for example. The design of the force characteristics over the actuation travel in electrically actuated brakes is important for the actuation time and the energy expenditure for applying the braking torque.
[0005] 2. Discussion of Background Information
[0006] Especially for electrically actuated service brakes of vehicles, there are high standards with regard to short actuation times and pressing force requirement. For example, today's vehicles demand an actuation time for full braking of around 200 ms. At the same time, in modern vehicle front wheel disc brakes, brake pad pressing forces of 30 to 40 kN can arise, in many cases even significantly more. Since actuation travel * pad pressing force is the energy requirement for actuation of the brake and leads to the required actuation power for a given actuation time, it is apparent that the electrical actuators require accordingly high levels of electrical power. If an actuation travel of 2 mm is covered for full braking for 40 kN of pad pressing force, the energy requirement is roughly 40 Ws. If the braking process here takes 0.2 s, an average mechanical power of at least 200 W per brake is required, which must be provided by the electrical actuator. Available mounting space, weight, costs, and current requirement for the electrical actuator require that the motor power be kept low, which is why an optionally large electrical actuator cannot be used.
[0007] For a linear electrically actuated brake, i.e., for linear transmission elements such as screws, ball screws, and fluids with a linear relationship between the actuation travel and actuator (force, torque), a pad pressing force rising linearly from zero to a maximal value is necessary, under the assumption of a constant coefficient of friction. The necessary transmission ratio of the linear brake is determined here by the required maximal force (full braking), as this must be guaranteed, and remains constant for all lower pad pressing forces. That is disadvantageous, however, because, in all other, generally more frequent cases, the electrical actuator cannot be optimally utilized and is over-dimensioned. For such a linear brake, the electrical actuator is thus operated, up to design full braking, with a smaller than possible load, while the transmission ratio and thus also the attainable actuation time are determined by the constantly high transmission specified for the case of full braking. As a result, optimal and/or short-as-possible actuation times cannot be achieved for linear brakes for braking that does not correspond to the case of full braking.
[0008] In addition, the cost pressure on electrically actuated brakes is also high, because they have to compete with relatively simple hydraulic brakes. Therefore, any possible cost optimization of the electrical actuator is important. It is understood here that the smaller the electrical actuator can be kept, the more advantageous it will be.
[0009] Non-linear electrically actuated brakes such as those described in WO 2010/133463 A1, in which a non-linear transmission element, such as a cam, eccentric, non-linear ramp, etc., is provided between the actuator and brake pad, offer an improvement over linear brakes. In WO 2010/133463 A1, for example, a shaft with an eccentric pin, or a cam to which the brake pad is secured, is turned by an actuation means. Here the torque of an electric motor is transmitted via a linkage and lever to the non-linear transmission element of the brake. Due to the eccentricity of the pin or cam, the brake pad is pressed against the friction surface, and a non-linear relationship arises between the actuation travel or angle of rotation of the shaft and the pad pressing force or the arising braking torque. Due to the eccentric or cam, a force transmission also arises (a small travel effects a high force), whereby the electrical actuator can be dimensioned so as to be smaller. This also makes it possible to shorten the actuation times in comparison with a linear electrically actuated brake.
[0010] As a rule, the installation conditions of the brake, in particular for vehicle brakes, are such that only a very limited mounting space is available to receive the brake, so that electrical motors of small size have to be used. The very high pressing force of the brake pad must be produced from the high speed of the preferably small electric motor. Instead of the linkage and lever of WO 2010/133463 A1, this can be also be achieved, for example, by a transmission driven by an electric motor. For example, the output stage of the transmission rotates the shaft that is integrated in the transmission and has the eccentric or cam, while the non-linear transmission element again acts on the brake pad. With such a transmission, even transmissions of 1:40 can be implemented in a tiny mounting space, whereby small electric motors can be used. The actuation time can thus be reduced even further. But such transmissions are very complex and therefore also expensive.
[0011] A parking brake is known from WO 01/90595 A1 in which a brake actuating linkage is actuated by an electrically driven drive connection. The drive connection is embodied in the form of a cam disc that is rotated by the electric motor and an adjusting element guided along a surface of the cam disc. The cam disc can be embodied such that a constant torque is set on the electric motor in order to shorten the braking time and to achieve a particularly rapid translational movement of the brake actuating linkage.
[0012] For release of a friction brake, often a return spring is tensioned, which is released during release of the friction brake, and opens the friction brake by means of the energy released thereby. For example, DE 10 2006 012 076 A1 shows an electrically actuated friction brake in which a return spring is tensioned during actuation, and is released for release. The electrical drive must therefore supply energy for tensioning the release spring during the entire actuation of the friction brake.
SUMMARY OF THE EMBODIMENTS
[0013] It is an object of the present invention to reduce the attainable actuation times of an electrically actuated friction brake and simultaneously to keep the friction brake inexpensive.
[0014] This object is achieved according to the invention through the provision of a second transmission element with an elevation curve and a coupling element provided on the first transmission element, wherein a follower element is arranged on the coupling element that follows the elevation curve under the action of the electrical actuator for actuating the first transmission element, wherein the second transmission element provides the input torque for the first transmission element and in that the input torques of the first transmission element over the rotational angle for different wear states of the brake pad result in an envelope curve and the input torque provided by the second transmission element over the rotational angle covers the range of the envelope curve. The second transmission element can supply much of the transmission required in the actuation device, whereby the electrical actuator is released. In the example of a transmission motor, for an otherwise identical friction brake, the transmission of the motor transmission can be reduced from 1:40 down to 1:12 (in the case of a non-linear second transmission element), because the second transmission element supplies force transmission (or torque transmission). A savings of 1 to 2 transmission stages can thus be achieved in the motor transmission, and hence a cost reduction. Simultaneously, the output torque of the electrical actuator becomes smaller, so that significantly smaller gears can be used in the motor transmission, which again results in a further price advantage. Due to the additional transmission of the second transmission element, however, the actuation time of the friction brake is also reduced. Conversely, at an actuation time to be achieved, the motor size can also be reduced. Likewise, operation can be ensured over the entire wear state of the friction brake.
[0015] The connection of the coupling element and of the first transmission element is done in a mechanically very simple manner if a first end of a lever in the coupling element is rotatably mounted and a second end of the lever is connected to the first transmission element.
[0016] A very especially simple and advantageous embodiment results if the second transmission element is embodied as a cam disc or as a sliding guide with an elevation curve and the electrical actuator rotates the cam disc or the sliding guide. In this way, the actuation device can be implemented by simple and robust means and in a very compact manner.
[0017] If two first transmission elements are provided, it is advantageous if they each be connected via a lever to the coupling element for formation of a parallelogram drive. By means of the parallelogram, a forced synchronization of the two transmission elements is effected in a simple and inexpensive manner.
[0018] In an alternative embodiment, the coupling element is designed as a rocker lever, whose knee joint is guided by a follower element along the elevation curve, wherein the electrical actuator acts on the first leg of the rocker lever, and the other leg of the rocker lever is connected to the first transmission element. By means of the rocker lever, especially high transmissions can be implemented in the second transmission element.
[0019] A very simple parking brake function can be implemented if an indentation is provided in the elevation curve, in which the follower element assumes a stable position. The actuation device can thus be fixed in a specific position (parking brake) and can no longer be released except by an outside force.
[0020] The first transmission element is preferably embodied as an eccentric drive or a cam drive, since high transmissions can thereby be implemented with short actuation travels.
[0021] It is very especially advantageous if the elevation curve is formed according to the path translation characteristic of the first transmission element. A substantially constant torque of the electrical actuator can be achieved in this manner. The electrical actuator can therefore always be driven over the entire actuation range of the actuation device in a specific torque range, in which favorable efficiencies can be achieved.
[0022] In order to achieve an automatic release of the friction brake over the entire actuation range, a release spring is advantageously provided that acts on the actuation device. If the release spring is tensioned or released via a spring follower element provided on the first transmission element, the range in which the release spring is tensioned or released can be controlled in a purposeful manner. In this way, the release spring can provide supplemental energy in specific ranges of the actuation range for return or actuation of the friction brake, and in other ranges support the electrical actuator in actuation or return of the friction brake.
[0023] Further effects and advantages of the of the present friction brake follow from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention is explained in more detail below with reference to FIGS. 1 to 9 , which show exemplary, schematic, and non-restrictive advantageous embodiments of the invention.
[0025] FIG. 1 shows a representation of a friction brake according to the invention,
[0026] FIG. 2 shows an alternative embodiment of the actuation device,
[0027] FIG. 3 shows the pad pressing force over the actuation range of the first transmission element,
[0028] FIG. 4 shows the input torque in the first transmission element over its actuation range,
[0029] FIG. 5 shows the arising torque and path transmission characteristic of the second transmission element,
[0030] FIG. 6 shows a representation of an inventive friction brake with release spring,
[0031] FIG. 7 shows the torque from the internal pad pressing force over the actuation range of the electrical actuator,
[0032] FIG. 8 shows the reset torque of the release spring over the actuation range, and
[0033] FIG. 9 shows the torque of the electrical actuator of a friction brake according to the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] FIG. 1 shows schematically an advantageous exemplary embodiment of a friction brake 1 according to the invention, here in the form of a disc brake with a brake disc as a friction surface 2 and a brake pad 3 , which is pressed by means of an actuation device 10 on the friction surface 2 for braking. The friction brake 1 could also be embodied as a drum brake, however, and could of course also brake linear movements, i.e., a flatiron as a friction surface instead of a brake disc, for example. Like here, the brake pad 3 can also be arranged on a brake pad carrier 4 . The friction brake 1 can be designed as a sufficiently known floating caliper brake, for example. Components of such a friction brake 1 known per se are not shown here for reasons of clarity, or are only suggested.
[0035] A first transmission element 5 connected to the brake pad 3 (or the pad carrier 4 ) and interacting with same acts on the brake pad 3 or the pad carrier 4 . The first transmission element 5 is embodied here, for example, as an actuation shaft 6 , on which an eccentric journal 7 is provided (suggested by means of the displaced rotational axes). For example, an eccentric journal 7 can be formed on the actuation shaft 6 , or an eccentric, axial borehole, into which a journal 7 is inserted, can be provided in the actuation shaft 6 . The actuation shaft 6 is rotatably mounted on a fixed part, for example on the brake caliper, or quasi-fixed part, for example on a wear adjuster, of the friction brake 1 . The brake pad 3 or the pad carrier 4 is arranged on the journal 7 . If the actuation shaft 6 is pivoted by a rotational angle a, the brake pad 3 moves the actuation travel s toward the friction surface 2 or away from same (suggested by the double arrow), depending on the direction of rotation. Instead of an eccentric journal 7 , a cam can also be provided as the transmission element 5 . For example, a rotational angle a of 90° from non-braking to full braking can be provided, and the eccentric or the cam can be geometrically designed in order to ensure the actuation travel s necessary for braking. This type of actuation of a friction brake 1 is described in WO 2010/133463 A1.
[0036] Moving the brake pad 2 against the friction surface 2 by means of a first transmission element 5 produces, starting with contact, a normal force (pad pressing force F N ) that effects the braking force or the braking torque. The normal force is thereby produced by the first transmission element 5 and is also received in full by the latter. That is, the normal force is fully supported by the transmission element 5 . Even an increased normal force due to potentially arising self-reinforcement effects is supported by the transmission element 5 .
[0037] In principle, the pressing of the brake pad 3 against the friction surface 2 can be implemented with any geometry and method that brings a “height gain,” i.e., a travel in the direction of the brake pad 3 . The first transmission element 5 is preferably non-linear. This means that there is no linear relationship between the input (here the rotational angle α, for example) and the output (here the actuation travel s, for example). It is also conceivable for the first transmission element 5 to be linear, however, for example as a cam with a linear elevation curve. The first transmission element 5 is also conceivable as a ball ramp or as rolling movement with thread turns. A cam is a rolled oblique plane, whereby it also being possible for the rolled plane to be rolling or in an any curve or surface in a plane or space, for example also as a helix or multiple helix, such as a ball ramp, thread turns, or rolling pitch, for example. Likewise, the first transmission element 5 can also comprise a hydraulic or pneumatic cylinder with pistons that is actuated for example by an eccentric or cam.
[0038] According to the invention, a second transmission element 8 is now provided in the friction brake 1 which interacts with the first transmission element 5 as described below.
[0039] Here, the second transmission element 8 comprises a cam disc 11 rotatably mounted on a center of rotation 9 and having an elevation curve 17 , which is driven by an electrical actuator 12 , here for example an electric motor of a transmission motor. The cam disc 11 or the electrical actuator 12 is supported on a fixed part 13 of the friction brake 1 , such as for example a brake caliper or a not shown, sufficiently known wear adjuster (regarded as quasi fixed), as suggested in FIG. 1 . A follower element 14 , for example a needle bearing, rolls on the cam disc 11 , whereas the follower element 14 being rotatably mounted on a coupling element 15 . Depending on the shape of the elevation curve 17 , the second transmission element 8 is thus linear or non-linear. Furthermore, the ends of two levers 16 are rotatably mounted on the coupling element 15 . In each case, the opposing ends of the levers 16 are secured to the actuation shaft 6 . From a mechanical standpoint, the coupling element 15 is a roller cam follower that is simultaneously part of a parallelogram drive. Of course, only one first transmission element 5 could be provided, in which case also only one lever 16 would be necessary. Likewise, more than two first transmission elements 5 could also be provided, and thus also more than two levers 16 .
[0040] If the curve disc 11 is rotated for example by the electrical actuator 12 clockwise, the follower element 14 rolls on the cam disc 11 , whereby the coupling element 15 is moved up or down according to the curve shape of the cam disk 11 . Due to the movement of the coupling element 15 , the actuation shaft 6 is simultaneously rotated via the lever 16 , and the brake pad 3 is pressed against the friction surface 2 . To raise the brake pad 3 from the friction surface 2 , the cam disc 11 is rotated in the opposite direction.
[0041] The kinematics of the actuation device 10 of the friction brake 1 thus consist of the path translation ratio (or equivalently the force- or torque transmission ratio) of the first transmission element 5 and the second transmission element 10 .
[0042] The elevation curve 17 of the second transmission element 10 can also be implemented by a sliding guide instead of a cam disc 11 . The elevation curve 17 can thus also be repeatedly rolled or spatially formed, thus enabling a range of rotation of more than 360° between the initial and end position. For example, the cam disc 11 can be formed as a helix, and the cam disc 11 can always be correctly positioned by a feed device, for example a thread. A sliding guide could also be formed in a spiral shape.
[0043] The elevation curve 17 of the cam disk 11 or a sliding guide or, more generally, any desired elevation curve 17 in space or in a plane can naturally be followed in any mechanically reasonable manner, i.e., apart from the described roller cam follower, a rocker lever or other guide of the follower element 14 as well. Following can naturally also be implemented differently than with a roller bearing, for example by means of a roller, a sliding contact, or a ball. Consequently, following is understood as rolling or sliding of the follower element 14 on the elevation curve 17 .
[0044] The coupling element 15 can also be embodied in multiple parts, for example several elements or levers connected in an articulated manner.
[0045] The elevation curve 17 of the cam disc 11 (or of the sliding guide) can also have a range that is shaped such that the follower element 14 in this range assumes a stable or energy-favorable position, so that the second transmission element 8 therefore cannot independently return, without external forces, in the direction of the unbraked position. This is provided in FIG. 1 , for example, at the end of the elevation curve 17 of the cam disc 11 in the form of an indentation 20 . If the follower element 14 comes to rest in this indentation, the follower element 14 cannot advance on its own from this position without the action of an external force, for example the electrical actuator 12 , a wire rope, or the like. This can be used for a parking brake function, for example.
[0046] A parking brake function can also be implemented by means of a detent latch. If, due to actuation of the actuation device 10 , a detent latch passes a specific position and engages, the actuator position (parking position) is likewise fixed. For unlatching, for example in order to release the parking brake, the detent latch must be released again, for example by means of a wire rope. An electromagnet can also be used to push the detent latch against a spring. The detent latch then remains locked in the parking position without magnetic action due to friction. For release, the actuation device 12 can be moved somewhat further along, whereby the friction is reduced and the spring releases the detent latch.
[0047] In an alternative embodiment of the inventive friction brake 1 according to FIG. 2 , a follower element 14 is again rotatably mounted on the coupling element 15 , and again rolls on an elevation curve 17 of the second transmission element 8 . The coupling element 15 is embodied here as a rocker lever, whereby the knee joint is rolling on the elevation curve 17 by means of the follower element 14 . On one leg of the coupling element 15 is again hinged one end of the lever 16 , by means of which a cam is rotated. An actuation lever 18 , which is actuated by means of a motor lever 19 driven by the electrical actuator 12 , acts on the other leg of the coupling element 15 . However, a linear drive could also act on the actuation lever 18 . The elevation curve 17 is arranged in a fixed position.
[0048] Other rolling guides are also conceivable. For example, the follower element 14 , which rolls on the elevation curve 17 , could also be guided with a sliding guide or a journal, which slides in a borehole.
[0049] The starting point for the design of a friction brake 1 according to the invention can for example be a predetermined pad pressing force F N -actuation travel s diagramor a pad pressing force F N -rotational angle a diagram, as shown in FIG. 3 . The diagram can reflect a linear or non-linear (as in FIG. 3 ) relationship. Such a diagram arises for example from the fundamental brake design, which considers the stiffnesses of the brake parts and the geometry of the first non-linear transmission element 5 , i.e. for example the geometric relationships on the eccentric, and is thus to be regarded as known, or it is predetermined according to the application. Different wear states of the friction brake 1 can also be considered. In FIG. 3 , the curve 3 a shows the brake without wear, and the curve 3 b shows the brake with full wear. The stiffness of the friction brake 1 is altered significantly as a result of the wear of the brake pad 3 . Likewise, the temperature influence on the stiffness of the friction brake 1 can also be considered.
[0050] From this pad pressing force F N -rotational angle a diagram, the required input torque T E of the first transmission 5 can be obtained from the known geometric relationships to achieve the pad pressing forces F N , as shown in FIG. 4 . Different wear states are again shown here, whereby the curve 4 a again reflecting the friction brake 1 without wear, and the curve 4 b the friction brake 1 with full wear. In order to be able to ensure operation of the friction brake 1 over the entire wear state, the input torque T E must cover the range that is given by the envelope curve (dotted curve 4 c ). This input torque T E is to be provided by the second transmission element 8 , which is designed accordingly.
[0051] For the electrical actuator 12 , however, it is especially advantageous if the latter can be operated over the entire actuation range with a torque as constant as possible (for example in case of an electric motor) or with a constant force, preferably in a range with high efficiency. Assuming a desired constant torque of the actuator 12 , the input torque T E or the envelope curve in FIG. 4 (applied to the input rotational angle of the second transmission element 8 ) directly represents the required torque transmission characteristic (or force transmission characteristic) of the second transmission element 8 . However, since the local torque transmission corresponds to the respective slope of the tangent of the path translation characteristic, the path translation characteristic, and thus the shape of the elevation curve 17 , conversely results as the integral of the torque transmission characteristic, as shown in FIG. 5 . In FIG. 5 the curve 5 a shows the torque transmission characteristic (envelope curve with allowance for wear) and the curve 5 b the integral of this curve, i.e. the path translation characteristic. The shape of the elevation curve 17 over the rotational angle α (actuation travel) can be derived directly from this in order to achieve a substantially constant torque of the electrical actuator 12 . For this reason, a non-linear second transmission element 8 is preferably used, the elevation curve 17 of which is formed according to the path translation characteristic of the first transmission element 5 .
[0052] For a friction brake with a transmission motor and a first transmission element according to WO 2010/133 463 A1, an actuation time of around 250 ms was measured with a pad pressing force of 40 kN. For a friction brake 1 according to the present invention, the actuation time could be reduced to around 180 ms, which represents a significant improvement.
[0053] In many electrically actuated friction brakes 1 , it is required that they be self-actuating in an energy-free state (electrical actuator 12 without power) and assume an unbraked state without electrical assistance. That can be impossible with high mechanical friction in the drive of the friction brake 1 , because in an electrical actuator 12 , a breakaway torque or a breakaway force, which typically is made up of the mechanical bearing friction and the magnetic “snap” and can amount to 10% of the nominal torque or nominal force, must first be overcome. In addition, with a transmission motor as electrical actuator 12 , for release, cranking against the gear ratio must also be performed with greater torque than present on the motor shaft. In friction brakes 1 with low mechanical drive friction and/or favorable path of actuation force, the friction brake 1 can press itself open by the high pad pressing force n specific ranges. However, this is not possible in all ranges, as for example with a very small pad pressing force (e.g. braking on ice or snow) no adequate force is available for pressing itself open against the breakaway torque. In this state, a non-electrical, storable auxiliary energy must be present for pressing open of the friction brake 1 . These can for example be a release spring, which is tensioned during braking, and which releases the stored energy for pressing open the friction brake 1 when needed.
[0054] When the auxiliary energy is supplied from actuation of the friction brake 1 itself, for example via a release spring, which is tensioned during brake actuation, the total actuation force (or the total actuation torque) is higher by the value of this spring action. Although the energy would not be lost, because it is recovered again no later than on release of the friction brake 1 , it increases the drive torque requirement. Thus, in the simplest case, the release spring would be continuously effective according to their spring characteristic, and thus additionally effective also in the range of large actuation torques, although the release springs in such ranges would be entirely unnecessary for the pressing open of the friction brake 1 . This can be counteracted with a non-linear transmission for the release spring by actuating the release spring by means of a suitably designed non-linear transmission, for example a release spring 21 that acts via a spring cam 22 , as described below with reference to FIG. 6 . The non-linear transmission is also driven by the actuation device 10 .
[0055] A spring cam 22 is arranged on an actuation shaft 6 and is co-rotated with the actuation shaft 6 . A spring lever 23 is rotatably mounted at one end. A spring follower element 24 , here for example a rotatably mounted roller, is arranged on the other end of the spring lever 23 and the spring follower element 24 follows the spring cam 22 and rolls thereon. Kinematically speaking, a roller cam follower is therefore implemented again. A release spring 21 acts on the spring lever 23 . If the spring cam 22 is rotated, the spring lever 23 is pivoted by an angle β, and the release spring 21 is thus tensioned.
[0056] However, without the spring cam 22 , the release spring 21 can also act directly on the first transmission element 5 or the second transmission element 8 and release the friction brake 1 and/or support it in actuation. For example, the release spring 21 can pull or press on a lever 16 or the parallelogram drive. Through the selection of the geometry (contact point of the release spring 21 on the actuation device 10 and/or on the friction brake 1 ), the release spring 21 can deliver variable torques to brake actuation, which can also change magnitude and sign during actuation of the friction brake 1 . For example, the return spring torque can become smaller due to the release spring 21 and the geometry when there is an increasing rotational angle α, can change sign and grow larger when there is an further increasing rotational angle α.
[0057] This release spring action, however it is caused exactly (cam, direct action of the release spring 21 , etc.), can also be effected on different positions of the friction brake 1 , not only on the actuation shaft 6 or the lever 16 or the parallelogram, but for example also on the cam disk 11 , the shaft of the electrical actuator 12 , the transmission stages of the electrical actuator 12 , on a separate transmission, etc. In short, at every point of the actuation device 10 via which the return effect or actuation effect of the release spring 21 can be applied by means.
[0058] The release spring 21 can also have uncoupling or coupling capabilities, for example by means of an electromagnet, in order for example to exert no actuation effect in an unpowered state, for example when the unpowered friction brake 1 must be forcibly moved to the released state.
[0059] The above-described method for obtaining a favorable path transmission characteristic of the second transmission element 8 does not assess the origin of the force (torque). Therefore, the release spring 21 , which is always or occasionally necessary for pressing open the friction brake 1 , can simply be used as an additional force. One thus obtains a total path transmission characteristic including release spring 21 for forming the transmission of the actuation device 10 . The previously described procedure can now be applied to determining the elevation curve of the spring cam 24 .
[0060] FIG. 7 shows the torque that the friction brake 1 exerts from its internal pad pressing force over the actuation range of the electrical actuator 12 on the latter. In the small actuation angle range, the torque is negative, that is, this negative torque is absent in order to release the friction brake 1 automatically. Again, a characteristic diagram over relevant states is used that covers all pad wear states, temperatures, and other influences. Accordingly, the dotted envelope curve 7 a is the range of the absent release torques and must be supplied by auxiliary energy (for example release spring 21 ). The cam elevation of the spring cam 22 is thus also established by the course of the release torque (envelope curve 7 a ) and the given kinematics. The release spring 21 is thus only tensioned where it is used as release assistance. If the electrical power supply in this rotational angle range fails, the friction brake 1 is reliably opened by the release spring 21 . Outside of this range, the release of the release spring 21 effects support of the electrical actuator 12 for the actuation process of the friction brake. In this way, the otherwise interfering release spring 21 suddenly becomes a support for actuation of the friction brake 1 .
[0061] The result is illustrated in FIG. 8 , which shows the course of the return torque T F over the rotational angle of the spring cam 22 . The return spring torque T F acts for small brake actuation as the internal force from the friction brake 1 to release the friction brake 1 . With strong braking (larger rotational angle), the release spring 21 is again released, in order to support the electrical actuator 12 in brake actuation.
[0062] The transmissions of the actuation device 10 and the release spring 21 mutually influence one another. Therefore, such a friction brake 1 is generally designed in an iterative process in which the optimization steps are repeated until the improvement potential is largely exhausted. One could also proceed in a new design of a friction brake 1 from an already known favorable release spring 21 with transmission or from an already known linear or non-linear transmission of the actuation device 10 .
[0063] The result of such optimization is illustrated in FIG. 9 , for example. The torque T of the electrical actuator 12 (curve 9 a ) and the return spring torque T F of the release spring 21 (curve 9 c ) are shown over the actuation range of the electrical actuator. Here, the achieved, substantially constant torque T of the electrical actuator over the actuation range is readily recognized. The curve 9 b additional allows for self-reinforcement effects of the friction brake 1 , whereby the necessary torque T of the electrical actuator 12 naturally drops.
[0064] The friction brake 1 according to the invention was described above using the example of a brake in which force (torque) must be actively applied in order to press on the brake pads as is required for example in motor vehicles. However, the direction of action of the electrical actuator 12 is insignificant for the invention. The electrical actuator 12 can also prevent the friction brake 1 from actuation with active force (torque), whereby the direction of action would be reversed. The energy for actuation of the friction brake 1 in this case can originate from an auxiliary energy source, such as a spring, for example. Such a friction brake 1 is used, for example, as a railroad brake, elevator brake, crane brake, etc., that has to brake when there is a power loss. The above-described release spring 21 can also be used as an auxiliary energy source for braking, the actuation curve then naturally being designed favorably for the actuation behavior of the brake. For such a friction brake 1 , the kinematics can be designed such that in the range to be kept open, the force (torque) at the electrical actuator 12 is as small as possible or even zero. This can occur similarly to as described above for the parking brake function over a special range of the cam disc, slide, or kinematics. A described detent latch could also be used to hold the friction brake 1 open.
[0065] In friction brakes 1 that are held in the released state by the electrical actuator 12 , for example in a railroad brake or an elevator brake, a spring, and/or the release spring 12 , can of course conversely be used for actuation of the friction brake 1 . The spring or the kinematics of the actuation device 10 can then also be favorably designed for this reverse actuation behavior.
[0066] In these spring-actuated friction brakes 1 , the actuation device 10 can be designed advantageously such that, for all cases to be covered (different or no self-reinforcement, different pad states and elasticities, different coefficients of friction, tolerances, return torque of the motor (“cogging”) in different motor states (also unpowered), different friction losses in actuation, temperature, etc.), reliable actuation by the spring is always possible.
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To reduce the attainable actuation times of an electrically actuated friction brake and simultaneously keep the friction brake inexpensive, a second transmission element ( 8 ) with an elevation curve ( 17 ) is proposed in which a coupling element ( 15 ) is provided on a first transmission element ( 5 ), and on the coupling element ( 15 ) there is arranged a follower element ( 14 ) which follows the elevation curve ( 17 ) under the action of the electric actuator ( 12 ) for the actuation of the first transmission element ( 5 ).
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This application is a continuation of now abandoned application, Ser. No. 07/578,309 filed Sep. 6, 1990 now abandoned.
FIELD OF THE INVENTION
The present invention relates to an improved method of recovering hydrocarbon halides.
BACKGROUND OF THE INVENTION
Hydrocarbon chlorides (such as methylene chloride, 1,1,1,-trichloroethane, trichloroethylene, tetrachloroethylene and carbon tetrachloride) have been widely used as a dissolving agent of rubber and fatty acid or a cleaning agent for dry cleaning and precision machines and elements. The hydrocarbon chlorides have many advantages in low boiling point, high solubility or detergency, non-combustibility and so on, but have some disadvantages in toxicity and carcinogenicity. They are therefore used under very limited conditions, e.g. limited concentration in drainage. Air pollution based on the hydrocarbon chlorides is also one of the big problems and very strict regulations have been applied since April 1989 in Japan.
The hydrocarbon chlorides are recovered or removed by an active carbon absorption method which, however, is insufficient because the absorbing rate is poor and the recovering process is complicated.
Hydrocarbon fluorides or Fleons or Flons (such as trichloromonofluoromethane (Fleon 11), trichlorotrifluoroethane (Fleon 113) and dichlorodifluoromethane (Fleon 12)) have also been widely used for spraying, refrigerant, a foaming agent, a solvent and a cleaning agent for IC or precision machine and elements. The hydrocarbon fluorides have a wide boiling point range within -40° to 50 ° C. and very low toxicity. They also have high solubility with oil and organic material and therefore exhibit very high detergency. Accordingly, the hydrocarbon fluorides are very important in recent industries.
However, in 1974, Professor Lorland of California University warned that Fleon gas which was exhausted into air reached the stratosphere without being decomposed in the troposphere and was decomposed by a strong ultraviolet beam at the stratosphere, so as to cause the decomposition or destruction of the ozone layer. He added that the destruction of the ozone layer reduced the ultraviolet beam absorbing capacity of the ozone layer and adversely increased the ultraviolet beam which reached to the earth's surface, so as to adversely affect the ecosystem. This means that, in respect to human beings, bad effects such as increase of skin cancer would be increased. He further warned that the destruction of the ozone layer is a public pollution on the whole earth. After that, many researches and studies have been conducted to find that ozone holes above the south pole and increase of skin cancer have been observed. As the result, it is recognized that the phenomena are substantial and represent a serious danger to human beings and have been considered as important problems in many international congresses, such as Montreal Protocol and Den Haag International Congress.
It is strongly desired to inhibit the use of some Fleon and to develop Fleon substitutes. It also has been intensely studied to recover Fleo and not to exhaust it in the air.
SUMMARY OF THE INVENTION
The present invention provides a method of effectively recovering a hydrocarbon halide and the use of a specific aprotic polar compound for said method. Accordingly the present invention provides a method of recovering a hydrocarbon halide comprising absorbing the hydrocarbon halide into an aprotic polar compound which has a 5 or 6 membered ring and a nitrogen atom at an alpha-position of a carbonyl group. In the present method, the absorbed hydrocarbon halide can be easily recovered at a high recovery of more than 90% by usual methods.
The present invention also provides the use of an aprotic polar compound which has a 5 to 6 membered ring and a nitrogen atom at an alpha-position of a carbonyl group for recovering a hydrocarbon halide.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a specific compound, i.e. the aprotic polar compound which has a 5 or 6 membered ring and a nitrogen atom at an alpha-position of a carbonyl group, is employed as an absorbing agent of the hydrocarbon halide. The aprotic polar compound is known to the art, but generally is represented by the following chemical formula: ##STR1##
wherein A represents a methylene group or --NR-- and R is an alkyl group having 1 to 3 carbon atoms. Typical examples of the aprotic polar compounds are 1,3-dimethyl-2-imidazolidinone (DMI), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-oxohexahydropyrimidine and a mixture thereof. Preferred are those having a dipole moment of 3.7 to 4.8 D, especially 4.0 to 4.7 D, such as 1,3-dimethyl-2imidazolidinone (DMI), N-methyl-2-pyrrolidone (NMP) and 1,3-dimethyl-2-oxohexahydropyrimidine. If the dipole moment is outside the above range, absorption and desorption abilities of the hydrocarbon halide are deteriorated. Although a particular theory does not govern the present invention, it is believed that the dipole moment is one of important factors for which the absorption and desorption abilities are varied.
The hydrocarbon halide to be recovered is occasionally present in gaseous form together with other gas, such as air, inert gas and the like. The hydrocarbon halide of the present invention may be off-gas containing the hydrocarbon halide, which is produced from many industries (i.e. precision industry, dry cleaning, microlithographic process, etc.). In the present invention, the hydrocarbon halide containing gas is contacted with the aprotic polar compound (liquid) to absorb the hydrocarbon halide into the aprotic polar compound. The contact is generally carried out by gas-liquid contacting processes which are known to the art. It is usually conducted by an absorption train or absorption tower which is also known to the art.
In the present invention, the hydrocarbon halide is absorbed into the aprotic polar compound in a high absorption ratio, i.e. more than 90% by weight, preferably more than 95% by weight.
The absorbed hydrocarbon halide may be recovered or desorbed at very high recovery of more than 90% from the aprotic polar compound. The recovering step is carried out by distillation, evaporation or introduction of heated air or nitrogen. The recovered hydrocarbon halide and aprotic polar compound can be used again.
In the present invention, the hydrocarbon halide is absorbed in the aprotic polar compound in a very high absorption ratio and can be recover or desorbed very easily. The aprotic polar compound per se is known to the art as solvent for chemical reactions and the like, but has not been used as a solvent for the gaseous state of the hydrocarbon halide. It is surprising that the aprotic polar compound can absorb the hydrocarbon halide at a very high absorption ratio and easily desorb it.
EXAMPLES
The present invention is illustrated by the following Examples which, however, are not to be construed as limiting the present invention to their details.
EXAMPLES 1 to 16
A test tube having an inside diameter of 26 mm and a length of 200 mm was equipped with a gas inlet tube and a gas outlet tube, and the gas inlet tube reached to the bottom of the test tube. The hydrocarbon halide was charged in the test tube and air was introduced thereto to form a mixture gas of the hydrocarbon halide and air. The above process is called a gas producing step. The amount of the hydrocarbon and other conditions (temperature, etc.) are shown in Table 1.
The same test tubes as mentioned above equipped with a gas inlet tube and a gas outlet tube were charged with 20 ml of the aprotic polar compound of the present invention. Four to six test tubes were connected with Teflon tubes and kept at an absorption step temperature as shown in Table 1 to constitute an absorption step.
The mixture gas produced in the gas producing step was introduced and passed through the test tubes of the absorption step and an absorption amount of the hydrocarbon halide in each test tube was measured by gas chromatography. The results are shown in Table 2.
The same tests were conducted by changing the hydrocarbon halide and aprotic polar compound as shown in Table 1. The results are shown in Table 2.
TABLE 1__________________________________________________________________________Example Hydrocarbon Temperature at Air flow rate Evaporation Absorption Aprotic polarNo. halide (ml) evaporation (°C.) (1/min) time (min) temperature compound.C.)__________________________________________________________________________1 Trichloroethane 5 2 1 40 20 DMI2 Trichloroethane 5 20 1 35 20 DMI3 Trichloroethylene 5 20 1 45 1 NMP4 Trichloroethylene 5 30 1 23 20 DMI5 Tetrachloroethylene 5 31 1 120 19 DMI6 Fleon 113 5 -20 0.5 55 5 DMI7 Fleon 113 5 1 0.5 25 19 DMI8 Fleon 113 13 16.5 0.5 27 3 NMP9 Fleon 113 25 14 0.5 53 4 NMP10 Fleon 11 5 5 ± 1 0.3 15 1-2 NMP11 Fleon 11 5 -2 ± 1 0.3 22 1-2 NMP12 Fleon 11 5 -23 ± 1 0.3 56 1-2 NMP13 Fleon 113 10 -10 ± 0.3 60 1-2 NMP14 Fleon 113 5 -23 ± 2 0.5 60 0 DMI + NMP*15 Fleon 113 5 -11 ± 1 0.5 18 2 DMI + NMP16 Fleon 113 5 2 0.3 21 1 DMI__________________________________________________________________________ + NMP *DMI + NMP shows a mixture of DMI 20 ml + NMP 4 ml.
TABLE 2__________________________________________________________________________ Absorption amount ml/20 ml · solv.ExampleGas concentration Absorption test tube Total absorptionNo. vol. % wt. % 1 2 3 4 5 6 amount (%)__________________________________________________________________________1 2.7 11.8 2.91 1.24 0.64 0.16 -- -- 98.52 3.13 13.0 2.77 1.58 0.57 0.10 -- -- 98.23 2.7 11.2 4.30 0.44 0.06 0.06 -- -- 97.64 5.15 19.8 4.53 0.43 trace -- -- -- 99.25 0.91 4.99 1.91 1.65 0.83 0.25 0.08 -- 94.26 3.3 10.2 1.76 1.23 0.85 0.52 0.26 -- 96.37 7.0 32.7 1.42 1.27 0.97 0.54 0.32 0.10 92.48 15.3 54.0 8.65 2.74 0.90 0.19 0.06 -- 96.59 15.0 53.5 14.2 5.51 2.30 0.89 0.31 0.10 93.210 21.1 61.7 3.69 0.96 0.30 0.02 -- -- 99.811 15.4 45.5 3.53 1.02 0.19 0.15 0.04 0.02 99.412 6.72 25.5 1.92 1.47 0.70 0.28 0.11 0.06 90.513 11.8 38.9 3.34 3.11 1.96 0.99 0.37 0.09 98.614 3.41 18.1 1.21 1.34 0.89 0.54 0.22 0.10 85.915 10.5 40.4 3.37 1.14 0.36 0.10 0.02 -- 99.716 16.0 47.4 3.51 0.99 0.16 -- -- -- 93.2__________________________________________________________________________
In Table 2, the gas concentration shows the hydrocarbon halide content of the mixture gas of the gas producing step in volume % and weight %.
As is apparent from the above Tables, DMI and NMP are very good absorbing agents of the hydrocarbon halide. Especially, the Fleon 113 content of the first absorbing tube of Example 9 almost reaches 41.5%.
EXAMPLES 17
The same test tube as Example 1 was charged with 5 ml of Fleon 113 and 20 ml of DMI and heated to 53±1° C., to which air was passed through at 0.5 l/min for 60 minutes. The produced gas was introduced into 6 test tubes containing 20 ml of DMI at 5° C. to absorb Fleon 113.
Absorption amounts of the test tubes were respectively 139, 1.17, 1.06, 0.77, 0.33 and 0.1 (ml/20 ml DMI) and the total absorption amount was 97.8%.
This Example shows that Fleon 113 could be substantially completely recovered from a mixture solution of Fleon 113 and DMI (containing 20 volume % (27.2 wt %) of Fleon 113) by passing through 30 liters of air at 50° C.
EXAMPLE 18
A 200 ml glass vessel equipped with an air introducing tube and a mixed gas outlet tube was charged with 10 ml of tetrachloroethylene, through which air was passed at 24.3° C. at a flow rate of 0.4 l/min. After 340 minutes, tetrachloroethylene was completely evaporated to produce a mixed gas having a volume concentration of 1.72 vol %, a weight concentration of 9.17 wt % and 17,800 ppm.
The mixed gas was passed through 200 ml of N-methyl-2-pyrrolidone at 20.5° C. in an absorption tue. The outlet gas from N-methyl-2-pyrrolidone contained no tetrachloroethylene until 50 minutes from the start. Then, the concentration of tetrachloroethylene in the outlet gas slowly increased and reached a limit concentration of 50 ppm after 220 minutes, at which the concentration of the absorbed liquid phase reached 3.13 wt %. After 340 minutes, the concentration of tetrachloroethylene in the outlet gas was 200 ppm and the concentration of the absorbed liquid phase was 4.75%. Accordingly, the total absorption percentage of tetrachloroethylene in N-methyl-2-pyrrolidone reached 99.7%. The concentration of tetrachloroethylene in the outlet gas was determined by a Drager detection tube (made by Dragerwerke AG, Germany) detection tube and the concentration of the liquid phase was determined by gas chromatography.
EXAMPLE 19
As described in Example 18, 10 ml of tetrachloroethylene was charged in a glass vessel equipped with an air introducing tube and a mixed gas outlet tube, through which 160 liters of air was passed at 18° C. for 400 minutes at a flow rate of 0.4 l/min. Then, tetrachloroethylene was completely evaporated to produce a mixed gas having a volume concentration of 1.47 vol %, a weight concentration of 7.91 wt % and 15,100 ppm.
The mixed gas was passed through 200 ml of 1,3-dimethyl-2-imidazolidinone at 20.5° C. in an absorption tube. The outlet gas therefrom contained tetrachloroethylene in an amount of less than 5 ppm until 170 minutes from the start. Then, the concentration of tetrachloroethylene in the outlet gas linearly increased and reached 70 ppm after 315 minutes. After 400 minutes, the concentration of tetrachloroethylene in the outlet gas was 100 ppm and the concentration of the absorbed liquid phase was 4.75%. Accordingly, the total absorption percentage of tetrachloroethylene in 1,3-dimethyl-2-imidazolidinone reached 96.5%.
EXAMPLE 20
An evaporator was charged with 12.8 ml of trichloroethylene at 0° C., through which air was passed at a flow rate 2 l/min for 80 minutes to produce a mixed gas having a trichloroethylene content of 117 mg/l and an air content of 2.0 vol % and 21,800 ppm. The mixed gas was then passed through four absorption tubes which were series-connected and contained 40 ml of 1,3-dimethyl-2-imidazolidinone of 5° C. The amount of trichloroethylene was 9.46 ml in the first absorption tube, 2.3 ml in the second one, 0.34 ml in the third one and 0.12 ml in the fourth, one. Accordingly, the total absorption percentage was 95.5% and the outlet gas concentration of each absorption tube was respectively 5,700 ppm, 1,770 ppm, 1,200 ppm and 990 ppm.
EXAMPLE 21
A mixed gas having a 1,1,1-trichloroethane content of 500 ppm was prepared by mixing 20.4 μl of 1,1,1-trichloroethane and 10 1 of air. The mixed gas (100 1) was passed through an absorption tube containing 20 ml of N-methyl-2-pyrrolidone at -25° C. The initial 50 1 of the mixed gas was substantially completely absorbed, but the remaining 50 1 was absorbed to give an outlet gas of 50 to 160 ppm. The outlet gas concentration was 46 ppm.
EXAMPLE 22
A three neck flask was equipped with a dropping funnel, a capillary and a rectifying column with which a low temperature trap (dry ice and acetone) and an absorption tube containing 40 ml of N-methyl-2-pyrrolidone at 0° C. were connected. The flask was put in a warm bath of 70° C., and a mixture of 70 ml of Fleon 113 and 100 ml of N-methyl-2-pyrrolidone were added dropwise over 60 minutes at 200 mmHg. Vaporized Fleon 113 was trapped by the low temperature trap and heated to fuse it, thus obtaining 65.1 ml of Fleon 113. The remaining Fleon 113 was absorbed with N-methyl-2-pyrrolidone in the absorption tube. The absorption amount was 0.6 ml determined by gas chromatography. The distillation residue contained 1.3 ml of Fleon 113 which was determined by gas chromatography.
The total Fleon 113 caught was 67 ml, i.e. 95.7%.
EXAMPLE 23
The same flask as in Example 22 was heated to 60° C., to which a mixture of 50 ml of Fleon 11 and 100 ml of 1,3-dimethyl-2-imidazolidinone was added dropwise over 45 minutes at 200 mmHg. The amount of Fleon 11 in the low temperature trap was 45.5 ml, the amount of it in the absorption tube was 0.2 ml and the distillation residue contained 1.3 ml of Fleon 11. The total Fleon 11 caught was 47 ml which is equivalent to 94%.
EXAMPLE 24
A 500 ml three neck flask was equipped with a capillary and a 50 cm rectifying column with which a cooling trap (-20° C.) and a low temperature trap (-70° C.) were connected. A mixture of 50 g of 1,1,1-trichloroethane and 100 ml of N-methyl-2-pyrrolidone was charged in the flask and distilled at 150 mmHg. The flask was heated to 120° C. and then slowly elevated to 150° C. a which distillation continued for one hour. The top temperature of the rectifying column was within 28° to 32° C. at which 1,1,1-trichloroethane was distilled out to the cooling trap. The cooling trap contained 38.2 g of 1,1,1-trichloroethane and the low temperature trap contained 5.7 g of 1,1,1-trichloroethane. The distillation residue contained 3.2 g of 1,1,1-trichloroethane which was determined by gas chromatography. The total 1,1,1-trichloroethane caught was 94.2%.
EXAMPLE 25
The same flask as in Example 24 was charged with a mixture of 120 g of tetrachloroethylene and 200 g of 1,3-dimethyl-2-imidazolidinone and distilled at a reduced pressure of 150 mmHg. The flask was heated to 170° C. from 120° C., at which distillation continued for 1.5 hours. The top temperature of the rectifying column was within 50 to 60 ° C. at which tetrachloroethylene was distilled out to the cooling trap. The cooling trap contained 98 g of tetrachloroethylene and the low temperature trap contained 11.6 g of tetrachloroethylene. The distillation residue contained 6.5 g of tetrachloroethylene which was determined by gas chromatography. The total tetrachloroethylene caught was 96.8%.
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The present invention provides a method of effectively recovering a hydrocarbon halide and the use of a specific aprotic polar compound for said method. Thus, the present invention provides a method of recovering a hydrocarbon halide comprising absorbing the hydrocarbon halide into an aprotic polar compound which has a 5 or 6 membered ring and a nitrogen atom at an alpha-position of a carbonyl group. In the present method, the absorbed hydrocarbon halide can be easily recovered by usual methods.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/108,345, filed Oct. 24, 2008, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The present invention relates in general to LED replacements for fluorescent lights.
BACKGROUND
LED-based lights shaped to replace conventional fluorescent tubes have appeared in recent years. Typically, such lights include a hollow tube with two end caps, one at each longitudinal end of the tube. The end caps generally include molded plastic cup-shaped bodies that slide over the ends of the tube to secure the end caps to the tube. End caps can seal ends of the tube to prevent contaminants from interfering with operation of the light. Additionally, each end cap can include one or more pins for compatibility with standard fluorescent fixtures. For example, many end caps carry two pins for compatibility with fixtures designed to receive standard-sized tubes, such as T5, T8, or T12 tubes.
SUMMARY
Embodiments of a replacement light for a fluorescent tube usable in a fluorescent fixture are disclosed herein. In one such embodiment, the light includes a housing having a first end and a second end opposite the first end. A support structure is disposed within the housing. At least one LED is positioned within the housing and is arranged on the support structure. A first seal has at least one aperture and is disposed within the first end of the housing. The first seal is configured to conform to an inner circumference of the first end of the housing. At least one electrical connector extends through the at least one aperture is and connectable to the fluorescent fixture.
In another such embodiment, the light includes a housing having a first end and a second end opposite the first end. A support structure is disposed within the housing. At least one LED is positioned within the housing and arranged on the support structure. Sealing means for replacing a conventional end cap are disposed within the first end of the housing.
Embodiments of a method of manufacturing a seal for a fluorescent tube replacement light containing at least one LED are also disclosed herein. In one such embodiment, the method includes providing a housing having a first end and a second end opposite the first end. A hardenable material is introduced to at least the first end of the housing. The hardenable material is hardened such that it conforms to an inner circumference of the first end.
These and other embodiments will be described in additional detail hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section of an example of a light tube according to one embodiment of the present invention;
FIG. 2 is a perspective view of an example of the end cap replacing seal of FIG. 1 ;
FIG. 3 is a perspective view of material being poured into a housing to form an end cap replacing seal; and
FIG. 4 is an exploded side view of an end cap replacing seal being inserted into a housing.
DESCRIPTION
Examples of LED-based lights including end cap replacing seals for use instead of plastic cup-shaped end caps and other types of end caps are discussed below with reference to FIGS. 1-4 . FIG. 1 illustrates a light 10 sized for placement in a fixture 12 designed to receive standard-sized tubes. The fixture 12 can be, for example, of the type for accepting a T5, T8, T12 or any other suitable tube. Alternatively, the fixture 12 can be of the type for accepting another light, such as a halogen light or an incandescent bulb.
The light 10 , as shown in FIG. 1 , includes a tubular housing 14 , a circuit board 16 , multiple LEDs 20 , and two end cap replacing seals 22 . The tubular housing 14 defines a through-bore 17 . The housing 14 can be made from polycarbonate, acrylic, glass or another light transmitting material (i.e., the housing 14 can be transparent or translucent). For example, a translucent housing 14 can be made from a composite, such as polycarbonate with particles of a light refracting material interspersed in the polycarbonate. While the illustrated housing 14 is cylindrical, housing having a square, triangular, polygonal, or other cross sectional shape can alternatively be used. Similarly, while the illustrated housing 14 is linear, housing having an alternative shape, e.g., a U-shape or a circular shape can alternatively be used. Additionally, the housing 14 need not be a single piece as shown in FIG. 1 . Instead, another example of a housing can be formed by attaching multiple individual parts, not all of which need be light transmitting. For example, a housing formed by attaching multiple individual parts can include an opaque lower portion and a lens or other transparent cover attached to the lower portion to cover the LEDs 20 . The housing 14 as shown in FIG. 1 can be manufactured to include light diffusing or refracting properties, such as by surface roughening or applying a diffusing film to the housing 14 . For compatibility with the fixture 12 as discussed above, the housing 14 can have a length such that the light 10 is approximately 48″ long, and the housing 14 can have a 0.625″, 1.0″, or 1.5″ diameter. Of course, housing 14 can have other suitable dimensions. Additionally, the housing 14 can define a groove 15 for slidably receiving the circuit board 16 .
The circuit board 16 , as illustrated in FIG. 1 , is an elongate printed circuit board. Multiple circuit board sections can be, for example, joined by bridge connectors to create the circuit board 16 . The circuit board 16 is slidably engaged with the groove 15 of the housing 14 , though the circuit board 16 can alternatively be clipped, adhered, snap- or friction-fit, screwed or otherwise connected to the housing 14 . For example, the circuit board 16 can be mounted on a heat sink that is attached to the housing 14 . As another example, the circuit board 16 can be secured by the seals 22 as is discussed below in greater detail. Also, other types of circuit boards may be used, such as a metal core circuit board. Or, instead of a circuit board 16 , other types of electrical connections (e.g., wires) can be used to electrically connect the LEDs 20 to a power source. Additional electrical components, such as a rectifier and filter, can also be mounted on the circuit board 16 .
The LEDs 20 can be surface-mount devices of a type available from Nichia, though other types of LEDs can alternatively be used. For example, although surface-mounted LEDs 20 are shown, one or more organic LEDs can be used in place of or in addition thereto. The LEDs 20 can be mounted to the circuit board 16 by solder, a snap-fit connection, or other means. The LEDs 20 can produce white light. However, LEDs that produce blue light, ultra-violet light or other wavelengths of light can be used in place of white light emitting LEDs 20 .
The number of LEDs 20 can be a function of the desired power of the light 10 and the power of the LEDs 20 . For a 48″ light, such as the light 10 , the number of LEDs 20 can vary from about five to four hundred such that the light 10 outputs approximately 500 to 3,000 lumens. However, a different number of LEDs 20 can alternatively be used, and the light 10 can output a different amount of lumens. The LEDs 20 can be evenly spaced along the circuit board 16 , and the spacing of the LEDs 20 can be determined based on, for example, the light distribution of each LED 20 and the number of LEDs 20 .
As shown in FIG. 1 , the seals 22 can be positioned in opposing ends of the housing 14 (i.e., in opposing ends of the through-bore 17 defined by the housing 14 ). The seals 22 can be made from a variety of materials, such as an epoxy or other resin-based substance, rubber, cork, gel, concrete, glass, clay, wax, a polymer, silicone, or another material. The seals 22 can prevent the unintended entry of objects to the interior of the housing 14 . The seals 22 can also perform additional functions as described below.
Each seal 22 can have a perimeter 22 a shaped to conform to an inner circumference of the housing 14 . As such, each seal 22 can have a perimeter 22 a substantially identical to an inner circumference of the housing 14 such that the seal 22 can plug an end of the housing 14 . For example, each seal 22 can be generally disc-shaped if the housing 14 is cylindrical. Alternatively, the seals 22 can be shaped to contact only portions of the inner circumference of the housing 14 when fit into ends of the housing 14 . Thus, while the seals 22 can serve to prevent the unintended entry of an object to the interior of the housing 14 , the seals 22 need not necessarily be air-tight or water-tight.
The thickness of the seals 22 (i.e., the distance that each seal 22 extends longitudinally from an end of the housing 14 toward a center of the housing 14 ) can be based on multiple factors. A large thickness can allow the seals 22 to strengthen the housing 14 , can be more securely engaged with the housing 14 , and/or can enhance the ability of the seals 22 to prevent unintended entry of an object to the interior of the housing 14 . However, a seal 22 with a large thickness can require more material to produce, can be more difficult to install in the housing 14 , and can limit the length of the housing 14 through which light can be produced. These factors, among others, can be considered to determine a proper seal shape. Additionally, the seals 22 can protrude from ends of the housing 14 (i.e., the seals 22 need not be fully contained within the housing 14 or flush with ends of the housing 14 ).
Each seal 22 can also define two apertures 24 a and 24 b to allow pins 26 a and 26 b to communicate between the socket 12 and circuit board 16 . The apertures 24 a and 24 b can be circular, with diameters as large as or larger than diameters of the pins 26 a and 26 b . However, apertures 24 a and 24 b can have alternative shapes, such as shapes that allow the pins 26 a and 26 b to pass through the seal 22 . The apertures 24 a and 24 b can also physically support the pins 26 a and 26 b . For example, each seal 22 can hold the pins 26 a and 26 b in position via a friction fit between the apertures 24 a and 24 b and the pins 26 a and 26 b , respectively. If the seals 22 are made from a material that is not electrically insulating, a rubber O-ring or other insulator can be included between the seal 22 and the pins 26 a and 26 b.
The pins 26 a and 26 b can physically and electrically connect the light 10 to the fixture 12 . The pins 26 a and 26 b can be the sole physical connection between the light 10 and the fixture 12 , though ends of the housing 14 and/or portions of the seals 22 can also contact the fixture 12 . The pins 26 a and 26 b can be directly electrically connected to the circuit board 16 as shown in FIG. 1 to provide power to the LEDs 20 from the fixture 12 , or the pins 26 a and 26 b can be coupled to another structure that in turn is electrically connected to the circuit board 16 . Of the four total pins 26 a and 26 b , two of the total four pins 26 a and 26 b can be “dummy pins” that do not provide an electrical connection. Alternatively, instead of pairs of pins 26 a and 26 b , other types of electrical connectors depending on the type of fixture 12 can extend through the seals 22 or otherwise past the seals 22 into the housing 14 . For example, a single pin can be used instead of two pins 26 a and 26 b for compatibility with a single pin fixture. Alternatively, three of the four total pins 26 a and 26 b can be “dummy pins” that do not provide an electrical connection, thereby permitting only one of the pins to electrically connect with the fixture 12 .
A variety of methods can be used to manufacture the seals 22 . In a first example, the seals 22 are formed from a liquefied or viscous material that is introduced to the housing 14 , and then hardened in the position shown in FIG. 1 . The liquefied or viscous material can be an epoxy prior to setting or mixing with a hardener, concrete prior to hardening, a polymer heated to above its melting point, melted wax, or another liquefied or viscous material. Several different processes can be used to form the seals 22 from the liquefied or viscous material depending on the characteristics of the material. For example, as shown in FIG. 3 , the circuit board 16 can be engaged with the housing 14 , and one end of the housing 14 can be sealed with a non-stick mat 28 or other structure while liquefied material 23 is poured into the top of the bore 17 of the housing 14 . The seal 22 can be formed when the material 23 dries or cures, and the apertures 24 a and 24 b can be drilled in the seal 22 for the insertion of pins 26 a and 26 b . However, prior to inserting the pins 26 a and 26 b into the apertures 24 a and 24 b , the housing 14 can be rotated 180° and the seal 22 forming process can be repeated at the other end by pouring liquefied material 23 through one of the apertures 24 a or 24 b . Finally, the pins 26 a and 26 b can be inserted into the apertures 24 a and 24 b in each seal 22 and electrically connected to the circuit board 16 . Alternatively, the circuit board 16 can be supported without being attached to the housing 14 during the seal 22 forming process, in which case the seals 22 , once hardened or cured, can each define a groove 22 b as shown in FIG. 2 for receiving and/or securing the circuit board 16 .
As another example of manufacturing the seals 22 , the housing 14 can be inserted into a pool of liquefied or viscous material, and the material can be allowed to harden to form the seal 22 . The insertion can occur with the pins 26 a and 26 b already coupled to the housing 14 such that the seals 22 are formed to include apertures 24 a and 24 b without drilling, in which case sleeves can be installed over the portions of the pins 26 a and 26 b that engage the fixture 12 during insertion of the housing 14 into the pool of material in order to avoid getting material on the pins 26 a and 26 b.
If the material is too viscous to be poured into the housing 14 , the material can be packed into an end of the housing 14 . For example, pliable clay can be packed in an end of the housing 14 and then be allowed to dry, or silicone sealant can be applied in the end of the housing 14 .
In yet another example, seals 28 as shown in FIG. 4 can be shaped prior to insertion into the housing 14 . For example, each seal 28 can be made from an elastic material such as rubber or cork, and each seal 28 can shaped to have a perimeter 28 a transitioning from slightly smaller than an inner circumference of the housing 14 to slightly larger than the inner circumference of the housing 14 , allowing the seal 28 to be press fit into the housing 14 as shown in FIG. 4 . If made from a less elastic material, each seal 28 can be shaped to have a perimeter slightly smaller than an inner circumference of the housing and a rubber O-ring or similar elastic strip can circumscribe the seal 28 . By using O-rings, the seals 28 can be inserted into the housing 14 without substantially deforming the seals 28 . Also, each seal 28 can define a groove 28 b for receiving and/or securing the circuit board 16 similar to the groove 22 b in the seal 22 .
Also, regardless of the elasticity of the seals 28 , installation of the seals 28 can include inserting the pins 26 a and 26 b through the apertures 24 a and 24 b in the seals 28 prior to the pins 26 a and 26 b being physically attached to the circuit board 16 . For example, the pins 26 a and 26 b can be coupled by flexible wires to the circuit board 16 , then inserted into the apertures 24 a and 24 b of the seals 28 , and then the seals 28 can be press-fit into the housing 14 . As another example, the pins 26 a and 26 b can be coupled to the circuit board 16 with the circuit board 16 disconnected from the housing 14 . The pins 26 a and 26 b can then be inserted into the apertures 24 a and 24 b . Then, the circuit board 16 can be slid into the housing 14 until the seal 28 is press-fit into the housing 14 , in which case the circuit board 16 is supported by the seals 28 instead of directly by the housing 14 .
Additionally, structures other than seals 22 or seals 28 can be used instead of plastic end caps. For example, tape can be applied over ends of the housing 14 , or the housing 14 can be formed of a solid rod that is drilled to accommodate pins 26 a and 26 b without end caps.
The above-described embodiments have been described in order to allow easy understanding of the invention and do not limit the invention. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structure as is permitted under the law.
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Disclosed herein is a replacement light for a fluorescent tube usable in a fluorescent fixture. The light includes a housing having a first end and a second end opposite the first end. A support structure is disposed within the housing. At least one LED is positioned within the housing and is arranged on the support structure. A first seal has at least one aperture and is disposed within the first end of the housing. The first seal is configured to conform to an inner circumference of the first end of the housing. At least one electrical connector extends through the at least one aperture is and connectable to the fluorescent fixture.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to recovery boiler furnace safety appliances. More specifically, the invention is directed to safe operating methods and apparatus for paper pulp mill recovery furnaces adapted to burn concentrated black liquor.
2. Description of the Prior Art
Pursuant to present-day paper pulp mill operations, raw wood is delignified by a thermo-chemical process comprising an approximately 350° F. cook in the presence of sodium hydroxide, sodium carbonate, sodium sulfide and other sodium based compounds. Under such conditions, the lignin binder in the raw wood matrix which holds the natural cellulose fibers together reacts with the sodium compounds to form water soluble lignin-sodium complexes thereby permitting a water wash separation of the black, tar-like lignin from the pulp for manufacture of bleached white paper.
Although the sodium compounds used in the aforedescribed process are relatively inexpensive, the quantities consumed in the 1500 tons of dry pulp per day production of an average pulp mill necessitate an economical recovery and re-cycle of the chemical values used for wood pulping. Moreover, such sodium-lignin complexes contain sufficient heat value and volatility to contribute favorably to the overall mill heat balance. These characteristics are combined in the liquor recovery furnace by fueling a boiler furnace with a concentrated flow stream of the spent or black pulping liquor. Combustion of the lignin fraction generates sufficient heat to evaporate the residual water vehicle and heat the steam required for the primary evaporative liquor concentration process. The residual ash, predominately sodium carbonate, falls to the furnace bed as a viscous smelt. Such smelt is cooled and dissolved in water to form the green liquor makeup stream from which the other fresh cooking liquor compounds are made.
Economics and thermal efficiency highly favor the use of such recovery furnaces but the practical, daily operation is critical and may be hazardous due to the explosive potential of a sodium-water reaction. Liquid sodium reacts to a combination of free water with explosive violence.
The presence of water containing boiler tubing above the furnace combustion chamber creates the greatest potential for such an explosion. As in any steam generating furnace, the boiler tubes are constantly subjected to high temperature and pressure stresses. In addition, however, such tubes in a sodium recovery furnace are subjected to a corrosive combustion atmosphere. Consequently, water leakage from the tubes is an ever present danger which occurs periodically as an operative fact and must be accommodated by appropriate safety procedures when it occurs.
Another necessary but hazardous operating circumstance arises from the viscous flow characteristics of the concentrated, 60% (plus) solids black liquor fuel that is consumed by such recovery furnaces. Such concentrated liquor fuel supply must be maintained above a certain temperature to be pumped and properly nebulized from spray nozzles for combustion. Consequently, the nozzle bearing spray guns are supplied from an externally heated circulation loop. Even so, in the course of normal operation, internal pipe walls of the circulation loop become coated with liquor deposits and, if allowed, will completely choke the passage. Accordingly, such circulation loop piping must periodically be purged with wash water. It is during such purging cycles that opportunity arises for an accidental discharge of purge water into the furnace smelt from an open liquor spray gun remaining in a firing port.
Still another hazardous operating circumstance relating to black liquor recovery combustion involves the critical balance of liquor solids and the heat available therefrom. Such liquor is derived from diverse pulp processing steps starting with the digester blow tanks and finishing with the pulp washers. The combination of aqueous residuals from such diverse steps is highly diluted and contains only about 5% solids. Accordingly, considerable concentration of the dilute liquor must occur before a combustible consistency is attained. Such concentration is a continuous evaporative process subject to numerous, critically balanced variables which occasionally fails to achieve the necessary 60 to 70% solids content. If the lignin/solids concentration in the black liquor fuel stream falls so low as to preclude sufficient lignin fuel content to evaporate all the water vehicle thereof, free water is available for direct, reactive contact with the sodium smelt in the furnace bed. When such conditions are allowed to continue, furnace explosions can and have occurred. For this reason, the solids content of the concentrated liquor to the spray guns is constantly monitored by means such as refractometer instruments. When the monitoring instruments detect a less than acceptable solids consistency, the pumps for the liquor spray supply loop are automatically stopped and automatic valves therein closed to preclude continued flows of such excessively dilute liquor to the spray guns.
Such response to a low liquor solids consistency condition meets the immediate explosion problem but creates a secondary problem of the supply loop line plugging as the liquor contained therein begins to cool. Consequently, under such conditions, the normal procedure is, as in the case of periodic line purge operation, to remove all liquor spray guns from their respective gun ports in the furnace wall and restart the circulation pumps so as to displace the low solids liquor in the liquor circulation piping system and to maintain sufficient fluidizing heat.
Whether prompted by periodic purge circulation or by a low liquor solids alarm, removal of liquor spray guns from respective furnace wall ports is a manual task. Unfortunately, such a recovery furnace has numerous liquor guns distributed about the firebox periphery. Consequently, the potential for oversight and failure to remove one or more guns is high. Moreover, the manual valves respective to each gun are subject to considerable handling abuse and tend to prematurely leak. A leaking gun tempts an operator to leave it in the port so he'll not have to cleanup the resulting floor mess.
It is, therefore, an object of the present invention to teach a method and apparatus which positively requires the removal of all liquor spray guns from a recovery furnace before the black liquor fuel supply circulation loop may be purged or resumed following a low consistency shutdown.
Another object of the present invention is to teach an apparatus for positively preventing the insertion if a liquor spray gun in a gun port during a periodic purge circulation interim or following a low consistency shutdown of the black liquor fuel supply system.
SUMMARY OF THE INVENTION
These and other objects of the invention which shall subsequently become apparent are accomplished by means of a swing safety gate apparatus for each firing port which, when closed, physically prevents the presence of a fuel gun in the port and also closes a switch in a series circuit including all such switches. When the black liquor fuel supply circulation system is stopped due to concurrent low consistency signals from the refractometers, all safety gate switches must be closed before the liquor circulation pump may be started again.
BRIEF DESCRIPTION OF THE DRAWING
Relative to the drawing wherein like reference characters designate like or similar elements throughout the several figures of the drawing:
FIG. 1 is a detail illustration of the present invention safety gate; and,
FIG. 2 is an integrated wiring and plumbing schematic of the present invention operating system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An essential apparatus to the present invention system is illustrated by FIG. 1 and generally characterized as a swing gate 10. A swing gate 10 assembly is mounted to the recovery furnace wall 11 adjacent each firing port 12. There may be 15 or more firing ports in a recovery furnace, depending on the size of the furnace.
Each swing gate assembly comprises a bar grate 13 of 3/8 inch diameter stainless steel rod, for example, formed to the shape shown having a port 12 obstructing portion 14 and an arm portion 15. The dominate characteristic of the obstructing portion is that the spacing between the bar undulations be sufficiently close as to prohibit insertion of a liquor spray gun nozzle therebetween. Obviously, the undulating bar construction of the firing port obstructing portion 14 could be replaced by other structural configurations such as a solid plate or an expanded metal grate. However, to be acceptable, other configurations should accommodate the auxiliary functions of the firing ports 12 such as visual firebox inspection windows and supplementary air drafts. The illustrated bar construction is ideally suited to the task as accommodating both primary and auxiliary functions but it also efficiently dissipates the radiant and convective heat absorbed by the furnace flame exposed surfaces thereof.
The arm portion 15 of the grate assembly is provided with a pivot journal 16 about which the entire grate may be rotated to the open position illustrated by phantom line 20. If the suggested stainless steel construction is used, it will be necessary to provide a magnetic metal segment 17 on the arm 15 to operatively cooperate with the permanent magnet actuator of a single throw proximity switch 21. A more conventional mechanical push-button type of limit switch may be used in lieu of a magnetic switch if desired.
Accessory to the foregoing essential function components are an open bottomed protective enclosure 22 and an adjustable abutment 23. A handle protrusion 18 from the arm portion 15 distal end facilitates manual manipulation of the grate.
The present invention safety system is schematically represented by FIG. 2 wherein the magnetic gate switches 21 are electrically connected in a series circuit 30 which also includes liquor gun holster switches 31, a safe alarm 32 and a start-up push-button switch 33.
The heavy line circuit portion of FIG. 2 represents the concentrated black liquor fuel circulation loop which comprises an externally heated circulation tank 40. From the tank 40, hot black liquor is drawn by a pump 41 driven by a prime mover such as electric motor 42. Pump 41 discharges into a parallel loop 43 wherein each shunt leg includes a refractometer 44 for continuously measuring the liquor consistency and emitting an actuating signal 45 in the event that such consistency falls below a predetermined set-point. The object of such parallel redundancy of liquor consistency monitoring is to require the concurrence of two identical instruments monitoring the same fluid flow stream as a condition precedent to further action. When such conditions occur, the entire flow stream is stopped by an interruption of line power to the pump motor 42 due to de-energization of the normally open, energize-to-close power relay 46.
Following refractance monitoring, the liquor fuel stream enters a ring header distribution pipe 47 around the periphery of the furnace 11. At appropriately spaced junctions, flexible conduits 48 carry the liquor from the header 47 to each of the manually manipulated liquor spray guns 49 which, in normal operation, are inserted through the firing ports 12 and held in the cradle of respective power oscillators.
Motor valves 51 and 52 in the header loop 47 provide automatic and immediate isolation of the header loop from the liquor supply when required. Motor valve 53 in a shunt leg between the pump 41 discharge and the circulation tank 40, is operatively interconnected with valves 51 and 52 so that the three valves function simultaneously with the starting and stopping of pump 41 motor 42. Header loop valves 51 and 52 close and shunt valve 53 opens when the pump 41 is stopped due to a commanded opening of power relay switch 46 in the motor 42 power supply.
Double throw solenoid switches 55 and 56, in the switch position illustrated by FIG. 2, direct operating power to the energized closed power relay 46 and the motor valves 51, 52 and 53 for normal running operation. Relay 54 in the motor valve control circuit is of the energized open type which closes upon loss of energy to the normal running circuit thereby connecting motive power to close motor valves 51 and 52 and open valve 53.
The illustrated normal running position for double throw switches 55 and 56 corresponds to the de-energized condition of the respective solenoids. Energization to throw these switches to the alternative, dotted-line, position is initiated by a signal pulse from the refractometers 44. Since switches 55 and 56 are in parallel with the line power, both switches must throw to de-energize the pump power relay 46. Upon switching to the alternative position, line power is connected to respective solenoid holding circuits which maintain the switches 55 and 56 in the alternative position. Also in the holding circuits are energized-to-open relays 57, 58 and 61, 62.
Relays 61 and 62 are in the switch 55 and 56 holding circuit to release one or the other in the event of a false actuating signal from one of the refractometers 44, for example. These relays 61 and 62 are of the normally closed, energize-to-open type which draw actuating energy from that portion of the normal operating circuit in parallel between the switches 55 and 56. Such actuating energy for the release relays 61 and 62 is normally interrupted by normally open, push-button switches 66 and 67. If only one of switches 55 or 56 is thrown to the alternative position by a false signal from a respective refractometer, normal operating power will remain available to the release relays 61 and 62 through the undisturbed switch 55 or 56. To restore the falsely thrown switch 55 or 56 to the normal operating condition, it is only necessary to manually close the appropriate push-button switch 66 or 67. On the other hand, if both switches 55 and 56 are thrown to the alternative position, no actuating energy is available to the release relays 61 and 62 notwithstanding closure of the push-button switches 66 or 67.
The solenoid operating circuit of holding circuit release relays 56 and 58 is in series with all the firing port gate switches 21 and the liquor gun holster switches 31. Consequently, operating power for these switches cannot be obtained unless all of switches 21 and 31 are closed. Even then, the double throw switches 55 and 56 will not throw to the running position due to normally open, manual switch 33. However, ready alarm 32 is provided to inform the operator that all firing ports 12 are safely closed and conditions are safe for liquor or wash water circulation through the header loop 47. Accordingly, when the ready alarm 32 indicates that all firing ports 12 are positively closed and all guns 49 are securely holstered, manual switch 33 may be closed to release holding relays 57 and 58 and allow re-start of pump 41.
It will be noted that gun holster switches 31 are redundant to gate switches 21 since the latter positively serves the primary safety objective. Singularly, the gun holster switches 31 cannot positively assure undesired fluid discharges through the firing ports 12 since it is common practice to have more guns 49 in the furnace proximity than firing ports 12 as maintenance replacements. Consequently, it would be possible to satisfy all gun holster switches 31 with one or more unconnected replacement guns 49 and still have an actively working gun in the port 12. Nevertheless holster switches 31 have a desirable housekeeping function by providing a reasonably reliable signal that the active guns 49 are holstered in appropriately drained sockets.
Auxiliary to the primary safety circuit heretofore described, are dependent circuits which permit safe operating flexibility pursuant to system maintenance.
Energized-to-close relay 64 is disposed between the primary line power and the pump power relay 46. Actuation energy is provided by the series gate switch 21 circuit. Consequently, if all switches 21 and 31 are closed, power is thereby available to start the pump 41 with a selective closure of manual switch 65. However, should any of the switches 21 and 31 be subsequently opened, energized-to-close relay 64 will also open thereby stopping the pump 41.
Adjunctive to the above safe running circuit for the pump 41 is an auxiliary switching circuit for permitting liquor to be circulated through the circulating loop 47 so long as all gates 13 are closed and guns 49 are holstered. Manual switch 63 is normally closed to the running position illustrated which drives the circulating loop valves 51 and 52 to the open position and shunt valve 53 to the closed position. When switch 63 is changed to the alternative position, power is derived from the gate switch 12 circuit which is inoperative unless all of switches 21 and 31 are closed. If power is available from the gate switch circuit, closure of switch 63 therewith will open the energize-to-open relay 54 thereby driving valves 51 and 52 open and valve 53 closed. Should power to the gate circuit fail as by reason of opening a switch 21 or 31, so, too, will power to the energize-to-open relay 54 fail thereby permitting relay 54 to close and complete the valve 51 and 52 closure circuit.
For the purpose of periodic liquor line flushing with fresh water or dilute black liquor, autovalves 71, 72, 73 and 74 are provided. Valve 71 in the flush water or liquor supply line is normally closed. Valve 72 in the fuel liquor tank 40 supply line is normally open as is valve 73 in the circulation loop 47 tank return line. Valve 74 to the liquor drain lines is normally closed. All of these valves are interlocked to be simultaneously operated to jointly compatible positions by the relay 70 which has mechanically interlocked opposite switch positions for two contact sets 70a and 70b. Actuation energy for the relay 70 is obtained from the firing gate circuit subject to a manual switch 69. In the normal running condition, no operating energy is available to the relay 70 which is statically biased to the switch 70a closure condition corresponding to a valve 72 and 73 open position and valves 71 and 74 to the closed position. To reverse the switch 70 contact condition whereby contacts 70a open and contacts 70b close, manual switch 69 must be closed upon a charged firing gate circuit. Should the firing gate circuit be subsequently opened, actuating energy to the relay 70 will fail thereby permitting reversion of the contacts 70a and 70b to the illustrated normal running position.
Having fully disclosed my invention, those of ordinary skill in the art will recognize obvious alternatives and mechanical equivalents to accomplish the same or similar objectives. For example, I have chosen electrically operated motor valves for my preferred embodiment. Obviously, pneumatic or hydraulic control valves may be substituted for the motor valves if desired. Similarly, relays and solenoid switches are utilized in the control circuit. Many of such devices may be replaced by solid-state conductive devices. Therefore, as my invention,
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During a clean-out period when black liquor supply lines to paper pulp mill recovery furnace fuel spray guns are circulated with purge water or when black liquor firing is interrupted due to low consistency solids, the removal and unauthorized insertion of such fuel spray guns is positively verified and prevented by swing gates and series condition switches respective to each gun port. In order for a liquor circulation pump to be restarted following an automatic shutdown, all gates must be closed across respective gun ports which simultaneously closes all gate switches.
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[0001] This application is a continuation-in-part of co-pending application Ser. No. 11/983,377 filed Nov. 8, 2007 which was a continuation-in-part of application Ser. No. 10/666,584, now abandoned, filed Sep. 18, 2003 which claimed priority from provisional patent application No. 60/411,907 filed Sep. 19, 2002. Application Ser. Nos. 11/983,377, 10/666,584 and 60/411,907 are hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of polymers and more particularly to a class of polymers with pendant alkyl chains.
[0004] 2. Description of the Problem Solved by the Invention
[0005] Polymers are very useful compounds that have a wide range of applications. It is known that different monomers allow the customization of properties of the polymer to suit the intended end use. A particular property that is very useful is that of hydrophobicity. A polymer with hydrophobic properties repels water and thus finds great use whenever this property is desired. This type of polymer is particularly useful as a coating, especially if it can be sprayed on.
[0006] The most common method of adding hydrophobicity to a surface is the use of waxes. Stains and other coatings often incorporate a wax to increase the surface tension of water. The disadvantages are the possible adverse effect on the adhesion, short service life due to oxidation and the relative ease of removal, either by mechanical means or through washing and leaching if incorporated into a coating. This method would not be suitable for a low-drag marine coating. Another method is the use of PTFE polymer or incorporation of PTFE polymers into the coating. The use of PTFE is prohibitive in most coatings applications.
[0007] U.S. Pat. No. 3,936,409 describes the synthesis of urea urethanes that can be used to protect various substrates from water, but these polymers do not have substantial hydrophobicity for many applications. U.S. Pat. No. 3,936,409 is hereby incorporated by reference.
[0008] What is badly needed is a polymer that can be made cheaply and can possibly be sprayed on to form a water repellant coating.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a hydrophobic polymer made by incorporating alkyl chains pendant to the main backbone of the polymer. Alkyl chains of from about 6 to over 22 carbons are present in fatty compounds well known in the art. The present invention allows creating polymers with these alkyl chains pendant to the polymer chain. It is well known that synthetic and naturally derived starting materials such as tallow diamine or ethoxylated tallow amine typically contain a mixture of chain lengths with varying degrees of branching and unsaturation. The unsaturated positions in the final polymer can be made to cross-link in the presence of a catalyst to increase the hardness and reduce the effect of heat and solvent borne exposures.
[0010] The present invention can be a replacement to current monomers or additive to common polymers to replace or modify the current polymers to alter the properties of a polymer. The present invention adds the known benefits of fatty compounds to common polymers such as hydrophobicity, or in altering the HLB (hydrophilic lipophilic balance) of polymeric surfactants.
[0011] The present invention is directed primarily to urea and urethane polymers, but can be useful in the incorporation of pendant alkyl structures in other types of polymers that use an amine or alcohol groups to form the linkage. Other polymer types which can utilize this invention include, but are not limited to the following: polyamide, polyester, polycarbonate, polyether, polysiloxane, and epoxy.
DESCRIPTION OF THE FIGURES
[0012] Attention is now drawn to several figures which aid in understanding the present invention.
[0013] FIG. 1 : Shows the process for making a polyurea with a pendant fatty chain.
[0014] FIG. 2 : Shows the process for making a polyurethane with a pendant fatty chain.
[0015] FIG. 3 : Shows the process for making several types of polymers with fatty pendant chains using a fatty acid and polyol as starting materials.
[0016] FIG. 4 : Shows the process for making polymers with fatty pendant chains using a fatty acid and diethanolamine as starting materials.
[0017] FIG. 5 : Shows the process for making polymers with fatty pendant chains using a fatty acid and diethylene triamine (DETA).
DETAILED DESCRIPTION OF THE INVENTION
[0018] It is well known in the art to combine polyols or polyol pre-polymers with organic isocyanates and other materials to form polymers and polymeric resins. In particular, paints and coatings often contain polyurethane or other polymeric coating materials derived from an amine or alcohol functional monomer. A generic urethane has the following structure:
[0000]
[0000] It is well known in the art that R and R′ can be the same or different. A typical polyurethane polymer is made up of chains of the form:
[0000]
[0000] or of the form:
[0000]
[0019] Multifunctional fatty compounds, such as polyamines or ethoxylated amines, can be reacted with isocyantes to form polymers or pre-polymers that have uses in coatings, films, fibers, or structural components. In particular, ethoxylated fatty acids can be combined with organic isocyanates to form polyurethane type polymers. The resulting polymer contains fatty chains that are covalently bonded pendant to the backbone of the polymer. Ethoxylated fatty acids and fatty diamines or similar compounds containing multiple isocyanate cross-linkable moieties can be mixed, with or without the aid of a co-solvent, with the polyol component of commercially available two-component systems to the extent they are soluble. In the case of polyurethane, the linked moiety is similar to that shown in FIG. 1 .
[0020] FIG. 1 . Shows synthesis of a typical polymer of the type described by this invention. R may be any alkyl or alkoxy group of between around 6 to around 22 carbons. R′ and R″ can be the same or different, chosen from a wide range of materials, including, but limited to, H, —(CH2) n H, —(CH2) n NH2, —[(CH2) n NH] m (CH2) o ]NH2, with n, m and o from 1 to 30, —(CH2CH2O) a — (CH2CH(CH3)O) b —(CH2CH(CH2CH3)O) c H with a, b, and c integers from 0 to 30, —(CH2) x H with x from 1-30, —(CH2) n N[(CH2CH2O) a — (CH2CH(CH3)O) b —(CH2CH(CH2CH3)O)CH]—(CH2CH2O) a —(CH2CH(CH3)O) b —(CH2CH(CH2CH3)O) n H, —[(CH2) n N(CH2CH2O) a —(CH2CH(CH3)O) b —(CH2CH(CH2CH3)O) c H] m (CH2) o ]N[(CH2CH2O) a —(CH2CH(CH3)O) b —(CH2CH(CH2CH3)O) c H]—(CH2CH2O) a —(CH2CH(CH3)O) b —(CH2CH(CH2CH3)O) c H. Together R′ and R″ must contain a total of at least two terminal —NH 2 or —OH or a combination of either totaling at least two. The use of alkoxylated polyamines (at least three terminal —OH groups are present) as included above, produces polymers with tertiary cross linking when reacted with diisocyanates as opposed to the linear structures that result from diisocyanates and alkoxylated primary amines. Another way to achieve tertiary cross linking is to utilize a polyisocyanate that has more than two isocyanate groups available for the urea/urethane reaction.
[0021] Quaternary alkoxy amines are produced from alkoxylated amines, and contain at least two terminal —OH groups, such as the Tomah Q-series, and can be polymerized in the same manner as alkylated amines.
[0022] Another embodiment of the invention is the use of fatty ether polyamines or ethoxylated fatty ether amines. FIG. 2 Describes the case in which the fatty moiety is an alkoxy group.
[0023] A typical example of an embodiment of the invention is to combine, for example, an ethoxylated amine with a polyisocyanate. By varying the reactants, various hardnesses and flexibilities can be achieved. By varying the type of isocyanate used, the speed of cure can be adjusted. By changing the functionality of the alkyl containing component, different properties can be achieved.
[0024] It is an object of the present invention to create a class of hydrophobic urethane and urea polymers with alkyl side chains pendant to the main polymer backbone.
[0025] It is another object of the present invention to provide a way to control cross-linking in a hydrophobic polymer by controlling the amount of unsaturation present in pendant side chains.
[0026] It is another object of the present invention to provide a way to control cross-linking in a hydrophobic polymer by controlling the number amine groups or alcohol groups in the polyamine/alkoxylated amine reactant utilized.
[0027] It is another object of the present invention to provide a way to control cross-linking in a hydrophobic polymer by controlling the number of isocyanates groups present in the polyisocyanate.
[0028] It is still another object of the present invention to provide a method of making low cost sprayable hydrophobic polymeric coatings.
[0029] The preferred embodiment of the present invention is primarily directed toward polyurethane and polyurea structures, but other embodiments can include the incorporation of pendant alkyl structures in other types of polymers that use an amine, carboxylic acid or alcohol group to form the linkage. Other polymer types which can utilize this invention include, but are not limited to, the following: polyamide, polyester, polycarbonate, polyether, polysiloxane, and epoxy.
[0030] The presence of pendant saturated or partially unsaturated fatty chains causes the resulting polymers to have hydrophobic and other desirable properties such as the ability to control the amount of final cross-linking between backbones and the pendant chains.
[0031] Another application of the invention is the use in water-proof or water resistant, semi-permeable materials. This is achieved by processing the material of the invention in such a way that it contains pores of a size that are larger than that of water vapor, and smaller than a water droplet, roughly on the order of roughly 90 microns in diameter. Processing can be achieved in many ways, including but limited to, molding, extrusion, sintering, and via air bubble formation during the synthesis reaction. The inclusion of these pores allow for the passage of water vapor through the film, while the pores are too small for water droplets to pass through. The hydrophobic nature of the material prevents wicking. Thus, an effective water barrier that allows water vapor to pass through.
[0032] Alternatively, by controlling the cross-link density of the polymeric material as described in the invention, a matrix can be achieved with the desired permeability. This utilizes the same principles as used in the manufacture of polyacrylamide gels that are used in PAGE electrophoresis for separating proteins of various sizes. The use of varying carbon chain lengths of the starting materials and, in the case of alkoxylated starting materials, the amount of alkoxylation, the properties of the final film can be adjusted to meet the various needs of the final application, such as strength and flexibility. A typical application of the invention would be in the manufacture of water-proof, breathable clothing.
[0033] By controlling the cross link density and hydrophobicity as described in the invention, other materials could also be separated. This would provide a means of separating materials from water or other solvents. Other gas phase separations are also within the scope of the invention.
[0034] FIG. 3 shows how similar polymers with pendant fatty chains may be reached by reacting fatty carboxylic acids, which are typically carboxylic acids with greater than 6 carbon atoms, with polyols including, but not limited to, trimethylol propane or pentaerythrol. The resulting polyol can then enter into the same types of polymerization reactions as the ethoxylated amines. If polyols with more than three hydroxyls are used, the resulting product can be used to increase tertiary cross link density, giving greater rigidity, or additional moles of a fatty carboxylic acid can be reacted to give greater hydrophobicity. Similarly, ethylene amines, such as diethanolamine, can be used as starting materials with fatty carboxylic acids to form the amide that has multiple hydroxyl groups, as shown in FIG. 4 . In the case of triethanolamine, the carboxylic acid forms an ester linkage and again, a polyol that can be polymerized similarly to the ethoxylated amines described above. Alternatively, fatty amines can be reacted with carboxylic acid functional polyols. Fatty amines can be reacted with polycarboxylic acids, so long as the number of carboxylic acid groups is three or greater, to form polycarboxylic functional amides. These polycarboxylic amides can then be reacted with a variety of polyols, including, but not limited to those described herein, to form hydrophobic polyesters. Another embodiment is to react polyamines, such as DETA (diethylenetriamine) and TETA (triethylenetriamine), with fatty carboxylic acids to yield a starting material that can then enter into reactions similar to the polyamines with pendant fatty chains, such as is shown in FIG. 5 . It is worth noting that in the case of polyamines where more than three amine groups are present, the amide nitrogen need not be reacted with epichlorohydrin to form a stable epoxy adduct. The above products can all then be reacted with isocyanates, polycarboxylic acids (including carboxylic acid anhydrides), epoxides, etc. to form hydrophobic polymers that can be used in all the applications described herein.
EXAMPLES
Example 1
[0035] 8 g of Tomah E-17-5 (poly (5) oxyethylene isotridecyloxypropylamine) was added to 10 g of Bayer Mondur E744 (pre-poly of diphenylmethane 4,4′-diisocyanate). The resulting tack free solid showed typical polymeric properties as it reacted. During the reaction, a highly fibrous and ordered plastic could be pulled from the vessel. The product liberated heat and foamed during the reaction as well.
Example 2
[0036] 6 g of Tomah E-17-2 (poly (2) oxyethylene isotridecyloxypropylamine) was added to 10 g of Bayer Mondur E744 (pre-poly of diphenylmethane 4,4′-diisocyanate). The resulting tack free solid showed typical polymeric properties as it reacted. During the reaction, a highly fibrous and ordered plastic could be pulled from the vessel. The product liberated heat, but foamed less than than Example 1. In a repeat of the reaction, the addition FB100 reduced foam substantially and resulted in a product that is much better suited to be a coating.
Example 3
[0037] 6 g of Tomah E-17-5 (poly (2) oxyethylene isotridecyloxypropylamine) was added to 10 g of Bayer Mondur N3200 (pre-poly of hexamethylene diisocyanate) and 0.5 g FB100 butyrate antifoam. The resulting tack free solid showed typical polymeric properties as it reacted. During the reaction, a highly fibrous and ordered plastic could be pulled from the vessel. The product reacted much slower than EXAMPLE 2 and foamed much less. This product was suitable as a coating or cast product.
Example 4
[0038] 4.3 g Tomah Q-17-5PG (74% active isotridecyloxypropyl poly (5) oxyethylene in propylene Glycol) were added to 10 g of Bayer Mondur E 744 (pre-poly of diphenylmethane 4,4′-diisocyanate). This reaction occurred very slowly with very little visible foaming. The material did form a translucent tack free solid after eight hours.
Example 5
[0039] 5.5 g of Crison Crisamine PC-2 (poly (2) oxyethylene primary cocoamine) was added to 10 g of Bayer Mondur E744 (pre-poly of diphenylmethane 4,4′-diisocyanate). The resulting tack free solid showed typical polymeric properties as it reacted. During the reaction, a highly fibrous and ordered plastic could be pulled from the vessel. The product liberated heat and foamed during the reaction but the addition of FB100 butyric antifoam helped reduce this. This material was optically clear. A slight reduction in Bayer Mindur E744 yielded a very soft flexible tack free material.
Example 6
[0040] 7 g of Crison Crisamine DC (cocodiamine) dissolved in 40 g of a 50:50 mixture of naphtha and acetone was added to 10 g of Bayer Mondur N3200 (pre-poly of hexamethylene diisocyanate). The products reacted very quickly, even with the solvent present and the aliphatic isocyanate. A tack free rubbery solid formed.
Example 9
[0041] 12 g of Tomah DA-17 (Isotridecyloxypropyl-1,3-diaminopropane) was added 10 g to Bayer Mondur N3200 (pre-poly of hexamethylene diisocyanate) in 40 g of naphtha. The reaction was almost instantaneous, white strands formed immediately upon contact and a tack free stringy mass resulted after the solvent was evaporated.
Example 10
[0042] 10 g of Crison Crisamine PC-2 (poly (2) oxyethylene primary cocoamine) was added to 5.8 g of Bayer Desmodur H (hexamethylene diisocyanate, HDI). The resulting tack free solid had a straw color, but good clarity and moderate to high stiffness with essentially no foaming.
Example 11
[0043] 10 g of Crison Crisamine PC-2 (poly (2) oxyethylene primary cocoamine) was combined with 10 g of Crison Crisamine DT-3 (Tris(2-hydroxyethyl)-N-tallowalkyl-1,3-diaminopropane) before being added to 12.9 g of Bayer Desmodur H (hexamethylene diisocyanate, HDI). The resulting material formed a tack free solid more quickly than Example 10. The resulting solid was very elastic with good clarity and essentially no foaming.
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A hydrophobic polymer well suited for applications such as general purpose coatings, ship coatings, fibers and sheets. The present invention is particularly well suited for making breathable, yet waterproof clothing.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims benefit to U.S. Provisional Application 61/071,647, filed May 9, 2008, which is herein incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with government support under Grant Number CA117991 awarded by the National Institutes of Health and Grant Number W81XWH-04-1-0101 awarded by the Department of Defense. The U.S. government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Cancer
[0003] Despite many years of research, there exists a compelling need to develop new and more effective therapeutic strategies for cancer. The use of many agents used in cancer treatment is limited because of their cytotoxic effects on normal tissues and cells. This is a particular concern for agents that kill cells by damaging DNA and/or inhibiting DNA replication.
Retinoids
[0004] Retinoids are a group of natural and synthetic analogues of vitamin A. All-trans-retinoic acid (ATRA), the biologically most active metabolite of vitamin A plays a major role in regulating cellular growth and differentiation. i Since retinoids are capable of inhibiting growth, inducing terminal differentiation and apoptosis in cultured cancer cell lines, there is a wide interest in their use in cancer therapy. ii The biological effects of retinoids result from modulation of gene expression, mediated through two complex types of nuclear receptors, retinoic acid receptors, and retinoid X receptors (RARs and RXRs). iii Each type includes 3 distinct subtypes (α, β, and γ) encoded by distinct genes. Each RAR and RXR subtype is expressed in specific patterns in different tissues and is thought to have a specific profile of gene-regulating activity. The nuclear receptors function as dimers. RARs form heterodimers with RXRs. RXRs are more versatile, binding to RARs and other nuclear receptors, including thyroid hormone receptors and vitamin D receptors. Therefore, ATRA and other retinoids, through a variety of mechanisms, can modulate the expression of an extraordinarily large number of genes. iv
[0005] One of the most impressive effects of retinoids is on acute promyelocytic leukemia (APL). Treatment of APL patients with high doses of ATRA results in most of the cases in complete remission (Castaigne et al., 1990). Other research has been conducted on retinoid-based therapies for other cancers. v
[0006] Exogenous application of retinoids such as ATRA inhibits the growth and induces apoptosis in prostate cancer cell lines. Pasquali et al showed that the concentration of ATRA was 5-8 times lower in prostate carcinoma tissue compared with normal prostate and benign prostate hyperplasia. vi In vivo studies showed that ATRA inhibited induction and caused the disappearance of prostate tumors in animals. vii In spite of these encouraging results, the effects of ATRA therapy on human prostate cancer in the clinic have been disappointing.
[0007] One of the causes of the scarce therapeutic effects seems to be the rapid in vivo metabolism of ATRA into inactive metabolites. viii The inhibition of cytochrome P450 mediated ATRA metabolism by retinoic acid metabolism blocking agents (RAMBAs) is a promising approach in order to increase the levels of ATRA. ix Liarozole, the first RAMBA to undergo clinical investigations, was shown to increase ATRA levels in the tumor, resulting in anti-tumor activity. x Although, clinical development of this compound for prostate cancer therapy was discontinued for undisclosed reasons, it was recently approved in Europe and USA as an orphan drug for the treatment of congenital ichthyosis. xi
[0008] PCA tumors that arise after anti-hormonal therapy generally are less differentiated. Differentiation therapy remains a promising therapeutic approach in the treatment and chemoprevention of a variety of cancers, including PCA. Among the differentiation agents, retinoids, rexinoids, retinoid-related molecules (RRIVIs) and histone deacetylase inhibitors (HDACIs) have shown promising biological activities as single agents in several preclinical studies of both hematological and solid malignancies. xii
[0009] A goal of differentiation therapy is to induce malignant cells to pass the block to maturation by allowing them to progress to more differentiated cell types with less proliferative ability. Others have led the way in the discovery of agents that inhibit the enzyme histone deacetylase, thereby altering chromatin structure and changing gene expression patterns. xiii RAs exert their effects via a nuclear receptor complex that interacts with promoters of RA-responsive genes. xiv
[0010] Applicants have reported on a family of compounds that inhibit the P450 enzyme(s) responsible for the metabolism of all-trans retinoic acid (ATRA). xv These compounds, also referred to as retinoic acid metabolism blocking agents (RAMBAs), are able to enhance the antiproliferative effects of ATRA in breast and prostate cancer cells in vitro. xvi In addition, the RAMBAs were shown to induce differentiation and apoptosis in these cancer cell lines. Applicants' observed that the breast cancer cell lines were exquisitely more sensitive to the RAMBAs. xvii
[0011] By introduction of nucleophilic ligand at C-4 of ATRA or 13-CRA, and modification of the terminal carboxylic acid group, Applicants invented a series of potent RAMBAs some of which are by far the most potent retinoic acid metabolism inhibitors known. xviii xix See U.S. Pat. No. 7,265,143, which is hereby incorporated by reference in its entirety.
[0012] Applicants also demonstrated that these RAMBAs inhibited the growth of several breast and prostate cancer cell lines and could exquisitely enhance the ATRA-mediated antiproliferative activity in vitro and in vivo. xx xxi xxii It was shown that VN/14-1 binds and activates the RARα,β,γ receptors, albeit it is significantly less potent than ATRA. Furthermore, none of the RAMBAs showed significant binding to either cellular retinoic binding proteins (CRABP I or II). XXiii It has also been demonstrated that some RAMBAs inhibited the growth of established breast and prostate tumor xenografts and that their mechanisms of action may in part be due to induction of differentiation, apoptosis and cell cycle arrest. xxiv xxv xxvi xxvii
[0013] Some of Applicants' proprietary RAMBAs appear to be the most potent ATRA metabolism inhibitors known. xxviii Furthermore, some of these proprietary RAMBAs also exhibit retinoidal and cell antiproliferative activities in a number of human cancer cell lines. These multiple biological activities have prompted Applicants to classify them as “atypical RAMBAs”.
[0014] The anti-neoplastic activities of RAMBAs may be cell type dependent. Applicants have shown that some RAMBAs (e.g., VN/14-1) are more effective in breast cancer cell lines while others (e.g., VN/66-1) are more effective in prostate cancer cell lines. xxix xxx xxxi xxxii
[0015] The apparent lack of sensitivity of the breast cancer cells (MDA-MB-231) and two prostate cancer cell lines (LNCaP and PC-3) to ATRA and some of Applicants' proprietary RAMBAs may be due to the differential expressions of various genes that are essential for retinoid activity.
[0016] There continues to be an urgent need to develop new therapeutic agents with defined targets to prevent and treat cancer, including prostate and breast cancer.
BRIEF SUMMARY OF THE INVENTION
[0017] Applicants' invention includes new RAMBAs that are potentially more potent than known RAMBAs.
[0018] One embodiment of Applicants' invention are novel RAMBAs without the phenolic hydroxyl group as shown in some of the RAMBAs of U.S. Pat. No. 7,265,143. Acylation presents a likely avenue for metabolic instability. 4-methoxyphenylretinamide has previously been identified as a major inactive metabolite of the closely related 4-hydroxyphenyl retinamide (4-HPR) in several animal and human studies. xxxiii
[0019] One embodiment of Applicants' invention includes replacing the phenol moiety with a more metabolically stable functionality, with a goal of modulating the physical properties of these analogs without affecting the enzyme and antiproliferative potencies already achieved by the RAMBAs of U.S. Pat. No. 7,265,143, for example, VN/66-1.
[0020] Applicants' invention also includes enantiomers of the new RAMBAs of the present application (structural formulae 2A, 3A, 3B, 4B, 4C and 5) and their use and enantiomers of certain RAMBAs of U.S. Pat. No. 7,265,143 and their use.
Anilineamide RAMBAs
[0021] The phenolic hydroxyl moiety may replaced with its classical isosteres, for example, halogens such as F and Cl, or non-classical bioisosteres, for example, —CF 3 , —CN, and —SH. xxxiv
[0022] General Formulae 2A represents new anilineamide RAMBAs of the present invention.
[0000]
[0023] where R 1 is an azole group, a sulfur containing group, an oxygen containing group, a nitrogen containing group, a pyridyl group, an ethinyl group, a cyclopropyl-amine group, an ester group, a cyano group, a heteroaryl ring or an 1H-midazole group, or R 1 forms, together with the C-4 carbon atom, an oxime, an oxirane or aziridine group;
[0024] each R 3 is independent and is selected from a halogen group, a cyano group, a thiol group, or an alkyl group substituted with at least one of a halogen group, a cyano group, and a thiol group; and
[0025] n is from 0 to 5.
[0026] Non-limiting examples of such sulfur containing groups include thiirane, thiol and alkylthiol derivatives. Examples of such alkylthiol derivatives include C 1 to C 10 alkyl thiols.
[0027] Non-limiting examples of oxygen containing groups include —OR 4 , where R 4 is hydrogen or an alkyl group (preferably a 1-10 carbon alkyl, more preferably methyl or ethyl), cyclopropylether or an oxygen containing group that forms, together with the 4-position carbon, an oxirane group.
[0028] Non-limiting examples of nitrogen containing groups include the formula —NR 5 R 6 , where R 5 and R 6 are independently selected from the group consisting of hydrogen and alkyl groups (preferably a 1-10 carbon alkyl, more preferably methyl or ethyl), or R 5 and R 6 may together form a ring. Preferably the ring formed by R 5 and R 6 is a imidazolyl ring or a triazole ring.
[0029] Azole substituent groups may be imidazoles and triazoles, including attachment through a nitrogen ring atom. The azole substituent groups may be 1H-imidazole-1-yl, 1H-1,2,4-triazol-1-yl and 4H-1,2,4-triazol-1-yl.
[0030] R 1 may be cyano, amino, azido, cyclopropylamino, or R 1 may be a nitrogen containing group that forms, together with the 4-position carbon, an aziridine group or an oxime group.
[0031] R 1 may also be a pyridyl group or an allylic azole group, preferably methyleneazolyl.
[0032] The definitions for R 1 of an ester includes substituent groups that contain an ester moiety, including substituent groups attached via an ester moiety.
[0033] Non-limiting examples of the alkyl group include linear and branched alkyl groups, including primary, secondary and tertiary alkyl groups, and substituted and unsubstituted alkyl groups.
[0034] The R 3 substituent groups may be F, —CN, —SH and —CF 3 .
[0035] An example of General Formula 2A is General Formula 2A′
[0000]
[0036] where R 3 and n are as defined for General Formula 2A.
[0037] Exemplary compounds of Formula 2A are Compounds VNLG/146, VNLG/153, and
[0038] Compounds 4-33.
[0000]
Sulfamoylated and Carbamate RAMBAs
[0039] Applicants' invention also includes blocking metabolic conjugation of the phenolic —OH group of the RAMBAs of U.S. patent by conversion to a corresponding sulfamate and carbamate. This strategy has been successfully used to improve the antiproliferative activity and metabolic stability of 2-methoxyestradiol xxxv xxxvi xxxvii xxxviii as well as several dual aromatase-steroid sulfatase inhibitors, some of which have been tested in phase I clinical trials. xxxix xl
[0040] General Formulae 3A and 3B are new sulfamoylated and carbamate RAMBAs of the present invention.
[0000]
[0041] Where R 1 has the same definitions as set forth for Formula 2A above; Each R 2 is independent and is a hydrogen or an alkyl group. Non-limiting examples of the alkyl group include linear and branched alkyl groups, including primary, secondary and tertiary alkyl groups, and substituted and unsubstituted alkyl groups.
[0000]
[0042] Where R 1 and R 2 have the same definitions as set forth for Formula 3A above.
[0043] Non-limiting examples of General Formulae 3A and 3B include General Formulae 3A′, 3B′, 3A″ and 3B″ below.
[0000]
[0044] Where R 1 and R 2 have the same definitions as set forth for Formula 3A above.
[0045] Non-limiting examples of General Formulae 3A and 3B are Formula 34 and 35 below:
[0000]
Heterocyclic Amide RAMBAs
[0046] Applicants' invention also includes new heterocyclic amine containing RAMBAs. General Formulae 4B and 4C are new heterocyclic amine containing RAMBAs of the present invention.
[0000]
[0047] Where R 1 has the same definitions as set forth for Formula 2A above;
[0048] Each R 5 is independently selected from a hydrogen atom, an alkyl group, and a ring containing a nitrogen atom.
[0049] Non-limiting examples of the ring containing a nitrogen atom include monocyclic and multicyclic rings, which consist of carbon atoms and one or more nitrogen atoms. The rings may also include other heterocyclic atoms, such as O, S and Si. The rings may be substituted or unsubstituted. Non-limiting examples of the ring containing a nitrogen atom include an amine group, an azine group, a triazine group, an azirene group, an azete group, an diazetidine group, an azole group, a triazole group, a tetrazole group, an imidazole group, an azocane group, a pyridine group, piperidine group, benzimidazole group, and purine groups. The ring containing a nitrogen atom may be substituted or unsubstituted and may be fused with another ring. The ring containing a nitrogen atom may be attached to the nitrogen atom via a carbon group or via a nitrogen group of the ring.
[0050] Non-limiting examples of the ring containing a nitrogen atom 2,3,4 triazoles, 1,3 imidazoles, 2,3,4,5 tetrazole.
[0051] Non-limiting examples of the alkyl group include linear and branched alkyl groups, including primary, secondary and tertiary alkyl groups, and substituted and unsubstituted alkyl groups. A non-limiting example is a tertiary butyl group.
[0000]
[0052] Where R 1 has the same definitions as set forth for Formula 4A above; and
[0053] X forms, together with the nitrogen atom, a heterocyclic ring. The heterocyclic ring may be substituted or unsubstituted and may be fused with another ring.
[0054] Non-limiting examples of the ring formed by X include monocyclic and multicyclic rings, which consist of carbon atoms and one or more nitrogen atoms. The rings may also include other heterocyclic atoms, such as O, S and Si. The rings may be substituted or unsubstituted. Non-limiting examples of the ring formed by X atom include an amine group, an azine group, a triazine group, an azirene group, an azete group, an diazetidine group, an azole group, a triazole group, a tetrazole group, an imidazole group, an azocane group, a pyridine group, piperidine group, benzimidazole group, and purine groups.
[0055] The fused ring may contain all ring carbon atoms or be heterocyclic.
[0056] A non-limiting example of a fused heterocyclic rings is a purine group.
[0057] Examples of General Formulae 4B and 4C are Formula 4A, 4B′ and 4C′ below:
[0000]
[0058] R 5 has the same definitions as set forth for R 5 in Formula 5B above.
[0000]
[0059] Where R 5 and n have the same definitions as set forth for Formula 4B above.
[0000]
[0060] Where X has the same definitions as set forth for Formula 4C above.
[0061] Exemplary compounds of Formula 4B and 4C are Compounds 36-48 and VNKG/148 and VNLG/145 below:
[0000]
[0062] Synthetic purine derivatives possess great potential to interfere with important cellular functions xli and a number of major purine-based drugs exist which find current application for the treatment of cancer xlii xliii and a variety of other diseases. xliv A further interesting pharmacological property of purine derivatives is that they can be transported across biological membranes by nucleobase active and passive transport systems, which have been characterized in a variety of mammalian cells. xlv
Non-4-Position-Hydroxyl RAMBAs
[0063] Applicants' invention also includes RAMBA compounds where the hydroxyl group of ring C is not in the 4-position. For Example, General Formula 5 and VNLG/147.
[0000]
[0064] Where R 1 has the same definitions as set forth for Formula 2A above.
[0065] A non-limiting example of General Formula 5 is VNLG/147.
[0000]
Enantiomers
[0066] The present invention also includes enantiomers of the new RAMBAs of the present application and their use and enantiomers of certain RAMBAs of U.S. Pat. No. 7,265,143 and their use.
[0067] VN/66-1 exists as a racemate of two enantiomers as a result of chiral C-4 and studies have been conducted with racemic (±)-VN/66-1. Racemic (±)-VN/12-1 (a potent RAMBA and also the methyl ester of (±)-VN/14-1) is considerably (up to 28-fold) a more potent RAMBA than either of the pure (4S)-(+)- or (4R)-(−)-VN/12-1 enantiomers. xlvi However, Applicants consider that the enantiomers may exhibit differential anti-neoplastic activities on PCa cell lines. It has been demonstrated from previous studies that the anti-neoplastic activities of the atypical RAMBAs, including (±)-VN/66-1 are independent of their RAMBA activity. xlvii xlviii xlix l li lii liii
[0068] Specifically contemplated are synthesis and use of (+)- or (−)- and (±)-VN/66-1 and (+)- or (−)- analogs of the RAMBAs of the present application.
[0069] One embodiment of the present invention involves the use of Applicants' new RAMBAs and enantiomers to treat cancer.
[0070] It is another object of the present invention to use Applicants' new RAMBAs and enantiomers to treat melanoma, leukemia, including acute promyelocytic leukemia, lymphoma, osteogenic sarcoma, breast, prostate, ovarian, lung, epithelial tumors, colon cancer, pancreatic cancer or other types of cancers.
[0071] One embodiment of the present invention is the use of Applicants' RAMBAs and enantiomers to treat breast cancer.
[0072] One embodiment of the present invention is the use of Applicants' RAMBAs and enantiomers to treat prostate cancer.
[0073] The pharmaceutical composition may contain a pharmaceutically acceptable inactive ingredient. The pharmaceutically acceptable inactive ingredient may be at least one selected from the group consisting of diluent, carrier, solvent, disintregrant, lubricant, stabilizer, and coating.
[0074] The method of treatment may be oral administration and the pharmaceutical composition may be formulated for oral administration.
[0075] The method of treatment may be parentral administration and the pharmaceutical composition may be formulated for parentral administration, including subcutaneous, intramuscular, intracapsular, intraspinal, intrasternal, or intravenous.
[0076] The compound may be used in a pharmaceutical composition. The pharmaceutical composition may be formulated for oral administration, parentral administration or for injectable administration.
[0077] In making the compositions of the present invention, the compounds of the present invention can be mixed with a pharmaceutically acceptable carrier or an excipient, diluted by an excipient or enclosed within such a carrier which can be in the form of a capsule, sachet, paper or other container. When the excipient serves as a diluent, it can be a solid, semi-solid, or liquid material, which acts as a vehicle, carrier, or medium for the compounds. Thus, the compositions can be in the form of tablets, pills, powers, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, soft and hard gelatin capsules, and other orally ingestible formulations.
[0078] The pharmaceutical compositions may be in the form of a solution, suspension, tablet, capsule or the like, prepared according to methods well known in the art. It is also contemplated that administration of such compositions may be by the oral, injectable and/or parenteral routes depending upon the needs of the artisan. The compounds of the present invention can be administered by nasal or oral inhalation, oral ingestion, injection (intramuscular, intravenous, and intraperitoneal), transdermally, or other forms of administration.
[0079] Some examples of suitable excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. The formulations can additionally include lubricating agents such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propyl-hydroxybenzoates, sweetening agents; and flavoring agents. The compositions of the present invention can also be formulated so as to provide quick, sustained or delayed release of the compounds of the present invention after administration to the patient by employing procedures known in the art.
[0080] The term “pharmaceutically acceptable carrier” refers to those components in the particular dosage form employed which are considered inert and are typically employed in the pharmaceutical arts to formulate a dosage form containing a particular active compound. This may include without limitation solids, liquids and gases, used to formulate the particular pharmaceutical product. Examples of carriers include diluents, flavoring agents, solubilizers, suspending agents, binders or tablet disintegrating agents, encapsulating materials, penetration enhancers, solvents, emollients, thickeners, dispersants, sustained release forms, such as matrices, transdermal delivery components, buffers, stabilizers, and the like. Each of these terms is understood by those of ordinary skill.
[0081] Aerosol formulations for use in this invention typically include propellants, such as a fluorinated alkane, surfactants and co-solvents and may be filled into aluminum or other conventional aerosol containers which are then closed by a suitable metering valve and pressurized with propellant, producing a metered dose inhaler. Aerosol preparations are typically suitable for nasal or oral inhalation, and may be in powder or solution form, in combination with a compressed gas, typically compressed air. Additionally, aerosols may be useful topically.
[0082] The amount of the compounds used in the treatment methods is that amount which effectively achieves the desired therapeutic result in animals. Naturally, the dosages of the various compounds of the present invention will vary somewhat depending upon the parent compound, rate of in vivo hydrolysis, etc. Those skilled in the art can determine the optimal dosing of the compounds of the present invention selected based on clinical experience and the treatment indication. The amount of the compounds of the present invention may be 0.1 to 100 mg/kg of body weight, more preferably, 5 to 40 mg/kg.
[0083] Suitable solid carriers are known, e.g., magnesium carbonate, magnesium stearate, talc, lactose and the like. These carriers are typically used in oral tablets and capsules.
[0084] Suitable carriers for oral liquids include, e.g., water, ethanol, propylene glycol and others.
[0085] Topical preparations useful herein include creams, ointments, solutions, suspensions and the like. These may be formulated to enable one to apply the appropriate dosage topically to the affected area once daily, up to 3-4 times daily as appropriate. Topical sprays may be included herein as well.
[0086] Depending upon the particular compositions selected, transdermal delivery may be an option, providing a relatively steady state delivery of the medication which is preferred in some circumstances. Transdermal delivery typically involves the use of a compound in solution, with an alcoholic vehicle, optionally a penetration enhancer, such as a surfactant and other optional ingredients. Matrix and reservoir type transdermal delivery systems are examples of suitable transdermal systems. Transdermal delivery differs from conventional topical treatment in that the dosage form delivers a systemic dose of medication to the patient.
[0087] The delivery may be enhanced by promoting a more pharmacologically effective amount of the compound reaching a site of action, preferably a cancerous tumor site. The delivery may also be enhanced by promoting a more effective delivery of the compound across a cell membrane or within the cell and across the intra-cellular space.
[0088] The RAMBAs can be converted into a pharmaceutically acceptable salt or pharmaceutically acceptable solvate or other physical forms (e.g., polymorphs by way of example only and not limitation) via known in the art methods. The RAMBA compounds of the present invention can also be administered as a prodrug or as a separate compound.
[0089] The method of treatment may be injectable administration and the pharmaceutical composition may be formulated for injectable administration.
[0090] As used herein, “treat” and all its forms and tenses (including, for example, treat, treating, treated, and treatment) refer to both therapeutic treatment and prophylactic or preventative treatment. Those in need of treatment include those already with a pathological condition of the invention (including, for example, cancer) as well as those in which a pathological condition of the invention is to be prevented. For example, “treat” means alter, apply, effect, improve, care for or deal with medically or surgically, ameliorate, cure, stop and/or prevent an undesired biological (pathogenic) process. The skilled artisan is aware that a treatment may or may not cure.
[0091] As used herein, the effective amount or “therapeutically effective amounts” of the compound of the present invention to be used are those amounts effective to produce beneficial results in the recipient animal or patient. Such amounts may be initially determined by knowledge in the art, by conducting in vitro tests or by conducting metabolic studies in healthy experimental animals.
[0092] A therapeutically effective amount of a compound of the present invention as a treatment varies depending upon the host treated and the particular mode of administration.
[0093] In addition to a single therapy, which is the case with the administration of, for example, a single compound of the invention, cancer treatments are commonly combined with other methods of treating cancer. Combination therapy includes combining the method of treating cancer as described in the invention and one or more cancer therapeutic methods. Cancer therapeutic methods include surgical therapy, radiation therapy, administering an anticancer agent (including, for example, antineoplastics (including, for example, novantrone, bicalutamide, esterified estrogens, goserelin, histrelin, leuprolide, nilandron, triptorelin pamoate, docetaxel, taxotere, carboplatin, and cisplatin) or combinations thereof, and angiogenesis inhibitors), immunotherapy, antineoplastons, investigational drugs, vaccines, less conventional therapies (sometimes referred to as novel or innovative therapies, which include, for example, chemoembolization, hormone therapy, local hyperthermia, photodynamic therapy, radiofrequency ablation, stem cell transplantation, and gene therapy), prophylactic therapy (including, for example, prophylactic mastectomy or prostatectomy), and alternative and complementary therapies (including, for example, dietary supplements, megadose vitamins, herbal preparations, special teas, physical therapy, acupuncture, massage therapy, magnet therapy, spiritual healing, meditation, pain management therapy, and naturopathic therapy (including, for example, botanical medicine, homeopathy, Chinese medicine, and hydrotherapy)).
[0094] The method of treatment and the pharmaceutical composition may further comprise an all-trans retinoic acid (ATRA) and/or another RAMBA, including the use of multiple RAMBAs of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0095] FIG. 1 shows the antiproliferative effects of VNLG/145 PC-3 cell proliferation measured after 6 days of treatment using a MTT assay. Data are means (SEM<±5%) of at least three independent experiments.
DETAILED DESCRIPTION OF THE INVENTION
Synthesis
Anilineamide RAMBAs
[0096] Scheme 1 and Scheme 2 below are examples of the syntheses of the Anilineamide RAMBAs. The examples involves the coupling of the imidazolyl carboxylic acid (VN/14-1) with various anilines using 1,3-dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBT) in dimethylformamide (DMF) to yield the corresponding amides. This synthesis has been used for synthesis of VNLG/145, VNLG/146, VNLG/147, VNLG/148, VNLG/152, and VNLG/153 and VN/66-1.
[0000]
[0000]
Sulfamoylated and Carbamate RAMBAs
[0097] Scheme 3 below shows an example of the synthesis of Compounds 34 and 35. VN/66-1 may be sulfamoylated under standard conditions liv lv , with sulfomoyl chloride in dimethyl acetamide to give Compound 34. The carbamate (35) may be synthesized in two steps from VN/66-1, first reacted with trichloroacetyl isocyanate to give the N-trichloroacetyl carbamate, followed by hydrolysis with K 2 CO 3 in MeOH/THF/H 2 O) to give Compound 35. N,N-dialkyl derivatives of 34 and 35 may be synthesized by reaction with appropriate alkyl halides under basic conditions. lvi
[0000]
Heterocyclic Amide RAMBAs
[0098] The heterocyclic and amide RAMBAs of the present invention may be synthesized as outlined in Scheme 4 below. Some reactions will involve the coupling of the imidazolyl carboxylic acid (VN/14-1) with various anilines using 1,3-dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBT) in dimethylformamide (DMF) to yield the corresponding amides. While other compounds will involve formation (i.e., reactions with carbonyldiimidazole (CDI)) of imidazolide intermediates followed by coupling with appropriate amino heterocyles. ivii For synthesis of Compounds 42, 44, 46 and 48, the primary amino groups will first be protected with di-tent-butyl dicarbonate (Boc) 2 O lviii prior to use for coupling reactions. The Boc groups will then be readily deprotected to give the desired compounds. With the recent availability of simple procedures for the synthesis of large numbers of substituted purines lix , purine related compounds may be synthesized.
[0000]
Non-4-Position-Hydroxyl RAMBAs
[0099] The compounds of General Formulae 5 may be made with synthesis methods similar to those for making VN/66-1.
[0100] In the above synthesis methods, the starting RAMBA may be a racemate or a (+) or (−) enantiomer to obtain an enantiomer of the RAMBAs of the present invention.
[0101] The synthesized compounds (intermediates and final products) may be purified by chromatographic procedures (flash column chromatography, TLC or HPLC) and/or crystallization. The compounds may be fully characterized by spectroscopic methods (IR, UV, NMR and MS) and elemental analyses. The melting points of all compounds may be determined with a Fisher-Johns melting point apparatus.
Enantiomers
[0102] Synthesis of VN/66-1 enantiomers: One synthesis of enatiopure (4S)-(+)-VN/66-1 and (4R)-(−)-VN/66-1 is outlined in Scheme 1 below, starting from racemic (45,R)-(±)-4-hydroxymethylretinoate which will be readily synthesized from commercially available all-trans-retinoic acid (ATRA) as previously described. 1x lxi Next the recent efficient and high yielding procedure reported by Learmonth lxii will be used to resolve the racemic allylic alcohol (1) to give the enantiopure alcohols 2 and 3. The procedure involves use of diacetyl-L-tartaric acid anhydride to precipitate the diastereoisomeric precursor (1a) of (4S)-(+)-1 and diacetyl-D-tartaric acid anhydride to precipitate the diastereoisomeric precursor (1b) of (R)-(−)-1 followed by mild hydrolysis to give eantiopure alcohols (Scheme 1). Based on previous studies, it is expected that the terminal methyl ester group will be stable under the mild hydrolysis of the diastereoisomers. lxiii lxiv These two alcohols are expected to have optical purity in the range 92 to 99%, which will be purified to 100% ee either by several recrystallizations or by HPLC using a Chiralcel OJ semipreparative column. lxv The enantiopure alcohols 2 and 3 will each be used to synthesize enatiopure (4S)-(+)-VN/66-1 and (4R)-(−)-VN/66-1 as previously described lxvi lxvii and will be characterized by HPLC, 1 H-NMR and optical rotation. It has been previously reported that conversion of the allylic alcohol to the corresponding imidazole via reaction with carbonyl diimidazole proceeds via SN i mechanism with retention of configuration lxviii corroborated by earlier studies. lxix
[0000]
[0103] Several alternative procedures to enantiopure VN/66-1 and analogs are described below.
[0104] There are several other methods to prepare chiral allylic alcohols such as asymmetric reductions lxx lxxi lxxii and enzymatic lxxiii , as well as non-enzymatic lxxiv kinetic resolutions. Compounds (s)-2 and (R)-3 may be synthesized via enantioselective reduction of precursor 4-ketone using (R)- or (S)-2-methyl-CBS-oxazaborolidine and BH 3 .Se 2 as recently reported for closely related retinoids lxxv (Scheme 4a). Another alternative method will be formation of amine salts lxxvii of (±)-VN/12-1 to form two diastereoisomers and subsequent separation by crystallization.
[0105] Another alternative method will be formation of amine salts lxxvii of (±)-VN/66-1 to form two diastereoisomers and subsequent separation by crystallization.
[0106] The coupling of some amines may be difficult. Applicants propose to use alternative strategies of amide syntheses as outlined in Scheme 4b below. These procedures involve either key pyridylthioester intermediate lxxviii or solid phase synthesis that involves reaction of the carboxylic acid with an activating chlorinating reagent. lxxix
[0000]
Evaluation
[0107] The new compounds synthesized may be screened at 1 and 10 μM concentrations for their ability to inhibit ATRA metabolizing enzymes using established procedure. lxxx lxxxi lxxxii lxxxiii lxxxiv Compounds may also be evaluated to determine their concentrations that will cause 50% enzyme inhibition (IC 50 values).
[0108] Potent RAMBAs from U.S. Pat. No. 7,265,143 VN/14-1 and VN/66-1 and liarozole can be used to determine the relative potencies of the new compounds.
Assessments of VN/66-1 Enantiomers In Vitro and In Vivo:
[0109] The RAMBA activities of the pure enantiomers, racemic VN/66-1 and 4-HPR (standard) and also their growth inhibitory effects on four PCa cell lines (LNCaP, LAPC4, C 4 -2B and LAPC4-BR may be tested. The RAMBA activities of (+)-VN/66-1 and (−)-VN/66-1 may also be tested to check for differential anti-neoplastic activities against the four prostate cancer cell lines.
[0110] Applicants also consider that the enantiopure (+)- and (−)-VN/66-1 may be more stable in in vitro and more importantly, in vivo.
[0111] In vitro stability of entiopure (+)- or (−)-VN/66-1 and the derivatives of VN/66-1 may be assessed by treating PCa cells with their IC 50 and IC 90 concentrations. Cells and media may be extracted at specific time intervals over the usual MTT assay conditions, and than analyzed by chiral HPLC column. To further evaluate their stabilities in vivo, animals may be dosed with 10 mg/kg of pure (+)- or (−)-VN/66-1. Blood will be drawn at specified times, processed and than analyzed as described above.
EXAMPLES
[0112] Applicants synthesized novel retinamides of the present invention with reactions that involve coupling of our imidazolyl carboxylic acid (VN/14-1) with appropriate amines/anilines using 1,3-dicyclohexylcarbodiiimide (DCC) and 1-hydroxybenzotriazole (HOBT) in dimethylformamide (DMF) as outlined in Scheme 1 below.
[0000]
[0000] Compounds VNLG/145, VNLG/146, VNLG/147, VNLG/148, VNLG/152 and VNLG/153 were tested and evaluated for their ability to inhibit the growth (proliferation) of PC-3 prostate cancer cells using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (Gediyal et al. 2005). VN/66-1 of U.S. Pat. No. 7,265,143 was tested side by side for comparison. The GI 50 values (concentrations that cause 50% growth inhibition) were determined from dose-response curves. See in FIG. 1 for VNLG/145.
[0113] The growth inhibitory experiments with the other compounds gave plots that were similar to FIG. 1 .
[0114] The structures of the six compounds of the present invention and the parent VN/66-1 and their GI 50 values are presented in Table 1 below.
[0000]
TABLE 1
Compounds
GI50 Values (μM)
1.86 ± 0.05
14.13 ± 7.12
1.70 ± 0.07
5.62 ± 0.37
0.61 ± 0.11
1.17 ± 0.05
1.70 ± 0.05
[0115] VNLG/152 is the same as Compound 6 above.
[0116] VNLG/152 and VNLG/153 exhibited potencies better than VN/66-1.
[0117] VNLG/145 and VNLG/147 exhibited potencies similar to VN/66-1.
[0118] It is contemplated that VNLG/145, VNLG/146, VNLG/147, VNLG/148, VNLG/152 and VNLG/153 (except for VNLG/147 (with a 2-hydroxy group)) may exhibit superior in vivo antineoplastic activity attributable to putative superior absorption, distribution, metabolism, and excretion (ADME) properties.
[0119] As used herein in the specification, “a” or “an” may mean one or more. As used herein in the claims, when used in conjunction with the word “comprising,” the words “a” or “an” may mean one or more than one. As used herein “another” may mean at least a second or more. Furthermore, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.
[0120] It is believed that the present invention and many of its attendant advantages will be understood by the forgoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof.
i Sonneveld et al, Human retinoic acid ( RA ) 4- hydroxylase ( CYP 26) is highly specific for all - trans - RA and can be induced through RA receptors in human breast and colon carcinoma cells , Cell Growth Differ, 9: 629-637, 1998 ii Lotan et al., Retinoids and apoptosis, implications for cancer chemoprevention and therapy , J Natl Cancer Inst, 87: 1655-1657, 1995 iii Mangelsdorf et al., The nuclear receptor superfamily, the second decade , Cell, 83: 835-839, 1995 iv Jonk, L. J., de Jonge, M. E., Vervaart, J. M., Wissink, S., and Kruijer, W. Isolation and developmental expression of retinoic-acid-induced genes. Dev Biol, 161: 604-614, 1994 v Altucci et al., The promise of retinoids to fight against cancer , Nat Rev Cancer, 1: 181-193, 2001.; Njar et al., Retinoids in clinical use , Med Chem, 2: 431-438, 2006 vi Pasquali et al., Abnormal level of retinoic acid in prostate cancer tissues , J Clin Endocrinol Metab, 81: 2186-2191, 1996 vii Altucci et al., The promise of retinoids to fight against cancer , Nat Rev Cancer, 1: 181-193, 2001.; Njar et al., Retinoids in clinical use, Med Chem, 2: 431-438, 2006 viii Miller, W. H., Jr., The emerging role of retinoids and retinoic acid metabolism blocking agents in the treatment of cancer , Cancer, 83: 1471-1482, 1998; Njar, V. 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Cytochrome p 450 retinoic acid 4- hydroxylase inhibitors, potential agents for cancer therapy , Mini Rev Med Chem, 2: 261-269, 2002; Njar et al., Retinoic acid metabolism blocking agents ( RAMBAs ) for treatment of cancer and dermatological diseases , Bioorg Med Chem, 14: 4323-4340, 2006; Belosay et al., Effects of novel retinoic acid metabolism blocking agent ( VN/ 14-1) on letrozole - insensitive breast cancer cells , Cancer Res, 66-11485-11493, 2006; Huynh et al., Inhibitory effects of retinoic acid metabolism blocking agents ( RAMBAs ) on the growth of human prostate cancer cells and LNCaP prostate tumour xenografts in SCID mice , Br J Cancer, 94: 513-523, 2006; Patel et al., Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice , J Med Chem, 47-6716-6729, 20041; Patel et al., Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth , Br J Cancer, 96-1204-1215, 2007 x Debruyne et al., Liarozol—a novel treatment approach for advanced prostate cancer: results of a large randomized trial versus cyproterone acetate , Liarozole Study Group. 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C., Nnane, I. P., and Brodie, A. M. Potent inhibition of retinoic acid metabolism enzyme(s) by novel azolyl retinoids. Bioorg Med Chem Lett, 10: 1905-1908, 2000 xix Patel, J. B., Huynh, C. K., Handratta, V. D., Gediya, L. K., Brodie, A. M., Goloubeva, O. G., Clement, O. O., Nanne, I. P., Soprano, D. R., and Njar, V. C. Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice. J Med Chem, 47: 6716-6729, 2004 xx Huynh, C. K., Brodie, A. M., and Njar, V. C. Inhibitory effects of retinoic acid metabolism blocking agents (RAMBAs) on the growth of human prostate cancer cells and LNCaP prostate tumour xenografts in SCID mice. Br J Cancer, 94: 513-523, 2006 xxi Patel, J. B., Huynh, C. K., Handratta, V. D., Gediya, L. K., Brodie, A. M., Goloubeva, O. G., Clement, O. O., Nanne, I. P., Soprano, D. R., and Njar, V. C. Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice. J Med Chem, 47-6716-6729, 2004 xxii Patel, J. B., Mehta, J., Belosay, A. Sabnis, G, Khandelwal, A. Brodie, A. M. Soprano, D. R. and Njar, V. C. Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth. Br J Cancer, 96: 1204-1215, 2007 xxiii Patel, J. B., Mehta, J., Belosay, A., Sabnis, G, Khandelwal, A., Brodie, A. M., Soprano, D. R., and Njar, V. C. Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth. Br J Cancer, 96: 1204-1215, 2007 xxiv Belosay, A., Brodie, A. M., and Njar, V. C. Effects of novel retinoic acid metabolism blocking agent (VN/14-1) on letrozole-insensitive breast cancer cells. Cancer Res, 66: 11485-11493, 2006 xxv Huynh, C. K., Brodie, A. M., and Njar, V C Inhibitory effects of retinoic acid metabolism blocking agents (RAMBAs) on the growth of human prostate cancer cells and LNCaP prostate tumour xenografts in SCID mice. Br J Cancer, 94: 513-523, 2006 xxvi Patel, J. B., Huynh, C. K., Handratta, V. D., Gediya, L. K., Brodie, A. M., Goloubeva, O. G., Clement, O. O., Nanne, I. P., Soprano, D. R., and Njar, V. C. Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice. J Med Chem, 47: 6716-6729, 2004 xxvii Patel, J. B., Mehta, J., Belosay, A. Sabnis, G, Khandelwal, A. Brodie, A. M. Soprano, D. R. and Njar, V. C. Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth. Br J Cancer, 96: 1204-1215, 2007 xxviii Njar et al., Retinoic acid metabolism blocking agents ( RAMBAs ) for treatment of cancer and dermatological diseases , Bioorg Med Chem, 14: 4323-4340, 2006 xxix Belosay, A., Brodie, A. M., and Njar, V. C. Effects of novel retinoic acid metabolism blocking agent (VN/14-1) on letrozole-insensitive breast cancer cells. Cancer Res, 66: 11485-11493, 2006 xxx Huynh, C. K., Brodie, A. M., and Njar, V C Inhibitory effects of retinoic acid metabolism blocking agents (RAMBAs) on the growth of human prostate cancer cells and LNCaP prostate tumour xenografts in SCID mice. Br J Cancer, 94: 513-523, 2006 xxxi Patel, J. B., Huynh, C. K., Handratta, V. D., Gediya, L. K., Brodie, A. M., Goloubeva, O. G., Clement, O. O., Nanne, I. P., Soprano, D. R., and Njar, V. C. 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Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth. Br J Cancer, 96: 1204-1215, 2007 li Gediya, L. K., Chopra, P., Purushottamachar, P., Maheshwari, N., and Njar, V. C. A new simple and high-yield synthesis of suberoylanilide hydroxamic acid and its inhibitory effect alone or in combination with retinoids on proliferation of human prostate cancer cells. J Med Chem, 48: 5047-5051, 2005 lii Gediya, L. Belosay, A, Khandelwal, A. Purushottamachar, P. Njar, V. C. O. Improved synthesis of histone deacetylase inhibitors (HDACIs) (MS-275 and CI-994) and inhibitory effects of HDACIs alone and in combination with RAMBAs or retinoids on growth of human LNCaP prostate cancer cells and tumor xenografts. Submitted to J. Med. Chem., 2007 liii Khandelwal, A., Gediya, L. K., Njar, V. C. O, Synergistic effects of MS-275 and VN/66-1 in a hormone-refractory prostate cancer model. Submitted to Cancer Research, 2007 liv Leese, M. P., Hejaz, H. A. Mahon, M. F. Newman, S. P. Purohit, A. Reed, M. J. and Potter, B. V. A-ring-substituted estrogen-3-O-sulfamates: potent multitargeted anticancer agents. J Med Chem, 48: 5243-5256, 2005 lv Leese, M. P., Leblond, B., Smith, A., Newman, S. P., Di Fiore, A., De Simone, G., Supuran, C. T., Purohit, A., Reed, M. J., and Potter, B. V. 2-substituted estradiol bis-sulfamates, multitargeted antitumor agents: synthesis, in vitro SAR, protein crystallography, and in vivo activity. J Med Chem, 49: 7683-7696, 2006 lvi Leese, M. P. Leblond, B. Smith, A. Newman, S. P. Di Fiore, A. De Simone, G. Supuran, C. T., Purohit, A., Reed, M. J., and Potter, B. V. 2-substituted estradiol bis-sulfamates, multitargeted antitumor agents: synthesis, in vitro SAR, protein crystallography, and in vivo activity. J Med Chem, 49: 7683-7696, 2006 lvii Frickel, F.-F., Nuerrenbach, A. Amides of retinoic acid with 5-amino tetrazole. USA, 1984 lviii Boenoist, E., Loussouarn, A., Remaud, P., Chatal, J., Gestine, J. Convinient and simplified approaches to N-momprotected triaminepropane derivaties: Key intermediates for bifunctional chelating agent. Synthesis: 1113-1118, 1998 lix Yang, J. Dan Q. Q., Liu, J. Wei, Z. Wu, J. and Bai, X. Preparation of a fully substituted purine library. J Comb Chem, 7: 474-482, 2005 lx Njar, V. C Nnane, I. P. and Brodie, A. M. Potent inhibition of retinoic acid metabolism enzyme(s) by novel azolyl retinoids. Bioorg Med Chem Lett, 10: 1905-1908, 2000 lxi Patel, J. B., Huynh, C. K., Handratta, V. D., Gediya, L. K., Brodie, A. M., Goloubeva, O. G., Clement, O. O., Nanne, I. P., Soprano, D. R., and Njar, V. C. Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice. J Med Chem, 47: 6716-6729, 2004 lxii Learmonth, D. A. 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Novel retinoic acid metabolism blocking agents endowed with multiple biological activities are efficient growth inhibitors of human breast and prostate cancer cells in vitro and a human breast tumor xenograft in nude mice. J Med Chem, 47: 6716-6729, 2004 lxxxii Patel, J. B., Mehta, J., Belosay, A. Sabnis, G, Khandelwal, A. Brodie, A. M. Soprano, D. R. and Njar, V. C. Novel retinoic acid metabolism blocking agents have potent inhibitory activities on human breast cancer cells and tumour growth. Br J Cancer, 96: 1204-1215, 2007 lxxxiii Belosay, A. Jelovac, D. Long, B. Njar, V. C. O., Brodie, A. Histone deacetylase inhibitors synergize with retinoic acid metabolism blocking agent (VN/14-1) in letrozole resistant human breast cancer cells. In The Endocrine Society's 88th Annual Meeting, Boston, Mass., USA, Jun. 24-27, 2006 lxxxiv Gediya, L. K. Chopra, P. Purushottamachar, P. Maheshwari, N. and Njar, V. C. A new simple and high-yield synthesis of suberoylanilide hydroxamic acid and its inhibitory effect alone or in combination with retinoids on proliferation of human prostate cancer cells. J Med Chem, 48: 5047-5051, 2005
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Retinoic acid metabolism blocking agents (RAMBAs). The RAMBAs may be used for treatment of cancer, including breast and prostate cancers. Methods for preparing novel retinamide RAMBAs. The methods include reacting RAMBAs with terminal polar carboxylic acid group with a variety of amines in the presence of suitable coupling reagents. The retinamide RAMBAs are potent inhibitors of the growth of prostate and breast cancer cells and may be useful for the treatment of these diseases in humans.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2009/059218, filed Jul. 17, 2009 and claims the benefit thereof. The International Application claims the benefits of German application No. 10 2008 044 955.5 DE filed Aug. 29, 2008. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a method for the “in-situ” extraction of bitumen or very heavy oil from oil sand deposits as a reservoir, as claimed in the claims. In addition, the invention also relates to the associated device for implementation of the method.
BACKGROUND OF INVENTION
[0003] For the extraction of very heavy oils or bitumen from oil sand or oil shale deposits by means of pipe systems which are introduced through boreholes, the fluidity of the raw materials which are present in a solid consistency has to be increased considerably. This can be achieved by increasing the temperature of the deposit in the reservoir.
[0004] If inductive heating is used for this purpose exclusively or in support of the usual SAGD (Steam Assisted. Gravity Drainage) process, the problem arises that adjacent inductors which are supplied with current simultaneously can have a negative effect on one another. For example, adjacent inductors which are supplied with current in opposing directions weaken one another in terms of the thermal energy deposited in the reservoir.
[0005] In the German patent applications DE 10 2007 008 292, DE 10 2007 036 832, and DE 10 2007 040 605, individual inductor pairs, i.e. forward and return conductors, are supplied in a predetermined geometric configuration with current in order to heat the reservoir inductively. The current strength is used for adjusting the desired the final output while the phase position is fixed at 180° between adjacent inductors. This supply of current in phase opposition follows necessarily from running an inductor pair comprising forward and return conductor to a generator. In a parallel patent application by the applicant designated “System for the in-situ extraction of a substance comprising hydrocarbons”, among other things, the control of the heat output distribution in an array of inductors is described, this being achieved through the adjustability of the current amplitudes and phase position of adjacent inductor pairs. All previous patent applications assume that the supply of current over lengthy time periods of from days to months undergoes only minor adjustments and that a generator is permanently assigned to an inductor pair.
SUMMARY OF INVENTION
[0006] Proceeding on this basis, the object of the invention is to propose suitable methods and to provide associated devices which will serve to improve efficiency in the extraction of bitumen or very heavy oil from oil sand or oil shale reservoirs.
[0007] The object is achieved in a method of the type referred to in the introduction in the measures described in the claims. An associated device is described in the claims. Further developments of the method and of the associated device are the subject matter of the respective dependent claims.
[0008] The subject matter of the invention is to configure the key parameters of the necessary electric power generators for the electric heating of the reservoir in a chronologically and/or locally variable manner and to provide the possibility of changing these parameters from outside the reservoir in order to optimize the extraction volume during the extraction of the bitumen or very heavy oil. This creates very far-reaching possibilities for controlling the supply of current to the inductors in that locally measured temperatures, in particular, can also be used as control variables. In addition, the temperatures in the reservoir can be measured in a locally distributed manner, for example on the individual inductors, but optionally also outside the reservoir, namely, in the overburden, i.e. in the area of rock above the reservoir, or in the underburden, i.e. in the area of rock below the reservoir.
[0009] In detail, the invention includes a wide range of different possible combinations of individually energizable inductors and of generators which can be assigned to these inductors. In particular, the following steps are possible:
[0010] The invention proposes implementing the supply of current to adjacent inductors in a chronologically sequential manner and using forward and return conductors which are preferably located spatially far apart. For this purpose, the chronologically sequential switching of four inductor pairs is shown further below by way of example. The inductors, which serve as forward and return conductors, can be selected by means of individual switches.
[0011] The supply of current to the inductor pairs can, for example, take place over identical time portions. Due to the high heat capacities of the reservoir, long time intervals in the region of hours or days can be chosen, provided the thermal loading capacity of the inductors is not exceeded.
[0012] The time portions for the supply of current can be chosen so as to be different for the individual inductor pairs and can be changed during different phases of exploitation of the reservoir.
[0013] The combination of forward and return conductors forming an inductor pair can be changed during different phases of exploitation of the reservoir.
[0014] The temperature of the inductors and/or that of the reservoir surrounding them can be used for controlling the time intervals and for putting the inductors together into forward and return conductor pairs. In this way, preference can be given to supplying current to inductors with a low thermal loading and/or to heating reservoir areas which are low in temperature.
[0015] The formation of an inductor pair can be used to influence the heat output proportions in the overburden, reservoir and underburden. During different chronological phases of exploitation of the reservoir, the two types of current supply—chronologically sequential or simultaneous current supply with multiple generators—can be switched between.
[0016] The lines can be configured to run in close spatial proximity to one another through the overburden on the generator and/or connection side in order to prevent or reduce undesired heating of the overburden.
[0017] Instead of the switches to forward and return conductors, multiple permanently connected generators can be used which can be operated chronologically sequentially or simultaneously at the same or different frequencies.
[0018] When current is supplied to adjacent inductors at different frequencies, no cancellation effects occur and the overall heat output (and its distribution) is given by the sum of the heat outputs (and their distributions) of the individual inductors.
[0019] The effective resistance which the reservoir constitutes as a secondary winding is very much higher with respect to forward and return conductors that are located far apart than in the case of closely adjacent conductors, as a result of which high thermal outputs can be introduced into the reservoir by means of comparatively small currents in the inductor (primary winding).
[0020] When the generators are operated at different frequencies, an inductive coupling of the generators with fundamentals and harmonics is preferably avoided, as this could otherwise lead to malfunctions of and/or high loads on the generators.
[0021] The capacitatively compensated inductors have basically to be produced so as to match the respective operating frequency. If the generators can deliver a small part of the total reactive power to be applied, or if the compensation thereof can be effected directly on the generator through capacitative and/or inductive connections, uniform inductor designs that are matched to an average operating frequency can be used. With the aid of these external compensation circuits, inductors which are otherwise identical can be operated at slightly different frequencies, which is sufficient to prevent cancellation effects.
[0022] The invention is based on the findings obtained from detailed studies that substantial advantages over the prior art can be attained by means of the steps described hereinabove. These are, in particular:
[0023] Re: 1: The effective resistance of the inductive reservoir heating is increased considerably, for example by a factor of 4. This means that, for current of the same amplitude into the inductor, the heat output in the reservoir can have a value four times higher compared to current supplied simultaneously.
[0024] Within the scope of the invention, model calculations were carried out: in accordance with the Finite Elements Method (FEM), a model containing just one conductor pair was taken as a basis, four such sections being arranged adjacent to one another and one further section containing no inductors forming the left and right boundary regions, respectively.
[0025] Together, a 2D FEM model advantageously emerges comprising eight individual inductors which, for example, foam four separate inductor pairs ( 1 / 5 ), ( 2 / 6 ), ( 3 / 7 ) and ( 4 / 8 ), as well as associated boundary regions. This 2D FEM model can be used for investigating the heat output distribution when different currents are supplied.
[0026] Calculations then yield a suitable heat output distribution where a first inductor serves as a forward conductor and an inductor located as far as possible therefrom serves as a return conductor. The total heat output is P 1 in W/m if the inductors are constantly supplied with a current of a predetermined amplitude I 1 at a predetermined frequency f 1 . A frequency of 10 kHz is preferably taken as the basis, with frequencies between 1 and 500 kHz being suitable in principle.
[0027] If all the inductors are simultaneously supplied with current of the same current amplitude I 1 at the same frequency f 1 , the result is a different heat output distribution. The currents of adjacent inductors each exhibit a phase shift of 180°. However, the total heat output amounts again to approximately P 1 in W/m.
[0028] Re. 2: If in the example described under item 1, for example, four individual inductor pairs ( 1 / 5 ), ( 2 / 6 ), ( 3 / 7 ) and ( 4 / 8 ) are each supplied with current for one quarter (25%) of the time, then for this purpose only one generator (converter) is needed which can supply the necessary current of the specified current amplitude (1350 A) with four times the effective power, but without the reactive power demand increasing. Thus, the mean heat output introduced into the reservoir over time would be the same as in the case of current supplied simultaneously, as described under item 1. This means that instead of four generators which each have to provide ¼ of the required heat output as effective power and, in addition, a reactive power depending on the inductor, only one generator is needed with four times the effective power, without the demand for reactive power increasing.
[0029] Re. 3: Control of the heat output distribution can now be achieved in accordance with the particular requirements. Thus, for example, inhomogeneities in the temperature distribution due to uneven heating through steam injection can, up to a point, be compensated for.
[0030] Re. 4: As under item 3, control of the heat output distribution can thus be effected.
[0031] Re. 5: The variation of the current supply over time in combination with the flexible choice of forward and return conductor can advantageously be used to protect the inductors from excessive temperature due to their ohmic losses that occurs in addition to external heating by the reservoir.
[0032] Re. 6: The heat output proportions in overburden, reservoir and underburden can be influenced up to a point through the supply of current to the inductors. This is examined in detail further below.
[0033] Re. 7: The losses in the overburden can be minimized by means of the latter steps. The bringing of all the lines through the overburden together allows a flexible arrangement of forward and return conductor together with the advantages as described under items 3-6.
[0034] Re. 8: Advantageously, a simple switching of the types of current supply is now possible.
[0035] Re. 9: It is alternatively proposed that current be supplied to adjacent inductors simultaneously but at different frequencies. By way of example, the connection of four inductor pairs to four generators of different frequency is possible.
[0036] Re. 10: Each generator feeds a forward/return conductor pair of inductors, the individual conductors lying spatially as far as possible from one another.
[0037] Re. 11: The frequencies of the generators involved should not in the case of the latter procedure be integer multiples of one another.
[0038] Re. 12: The frequencies of the generators involved can be nearly equal, e.g. deviate from one another by less than 5%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Further details and advantages of the invention will emerge from the description of the figures below of exemplary embodiments based on the drawings in conjunction with the claims.
[0040] FIG. 1 shows a section from an oil sand deposit comprising repeating units as the reservoir and a respective electrical conductor structure running horizontally in the reservoir;
[0041] FIG. 2 shows the schematic layout of the circuit arrangement of four inductor pairs with a chronologically sequential current supply,
[0042] FIG. 3 shows the schematic layout of the circuit arrangement of four inductor pairs with a simultaneous current supply by means of separate generators which may have different frequencies, the associated forward and return conductors lying spatially far from one another and
[0043] FIG. 4 shows the schematic layout of the circuit arrangement of four inductor pairs with separate generators of different frequencies, the associated forward and return conductors lying near to one another.
DETAILED DESCRIPTION OF INVENTION
[0044] Whereas FIG. 1 shows a perspective representation as a linearly repeating arrangement (array), FIGS. 2 to 4 are in each case top views, i.e. horizontal sections in the inductor plane seen from above, the overburden being located on the two opposing sides. The same elements in the figures have the same reference characters. The figures are described, in part jointly, below.
[0045] For the extraction of very heavy oils or bitumen from oil sand or oil shale deposits by means of pipe systems which are introduced through boreholes into the oil deposit, the fluidity of the solid-like bitumen or of the viscous very heavy oils has to be improved considerably. This can be achieved by increasing the temperature of the deposit (reservoir), the effect of which is a lowering of the viscosity of the bitumen or very heavy oil.
[0046] The applicant's earlier patent applications were aimed primarily at using inductive heating to support the usual SAGD process. The forward and return conductors of the inductor lines, which together form the induction loop, are arranged at a comparatively large interval of, for example, 50-150 m. The reciprocal weakening of the forward and return conductors which are supplied with current in opposing directions is in this case small and can be tolerated.
[0047] Increasingly, EMGD processes are being considered in which inductive heating is to be used as the only method of heating the reservoir, without the introduction of hot steam, which brings with it the advantage among others of reduced or practically zero water consumption.
[0048] Where inductive heating alone is used, the inductors have to be arranged nearer to the bitumen production pipe so as to enable an early production start with simultaneously reduced pressure in the reservoir. In this way, the forward and return conductors likewise move closer together. This brings with it the problem that the reciprocal field weakening of the forward and return conductors which are fed with current in opposing directions is considerable and results in decreased heat output. While this can in principle be compensated for by higher inductor currents, this would, however, increase the demands on the conductors in terms of current-carrying capacity and thus considerably increase the production cost thereof.
[0049] It is possible to supply current to conductors which are spatially closely adjacent in a chronologically sequential, i.e. non-simultaneous, manner, as a result of which the problem of field weakening does not arise. It is advantageous here that one generator (converter) can be used for multiple conductor loops. A disadvantage, however, is that the inductors are supplied with current only for a fraction of the time and only then contribute to the heating of the reservoir. This is illustrated further below with the aid of FIGS. 2 to 4 .
[0050] FIG. 1 shows an arrangement for inductive heating. This can comprise a long, i.e. from several hundred meters up to 1.5 km long, conductor loop 10 to 20 laid in a reservoir 100 , the forward conductor 10 and return conductor 20 running alongside one another, i.e. at the same depth at a predetermined distance, and being connected at the end via an element 15 as the conductor loop inside or outside the reservoir 100 . Initially, the conductors 10 and 20 lead vertically or at a predetermined angle downward in boreholes through the overburden and are supplied with electric power by an HF generator 60 which can be accommodated in an external housing.
[0051] In particular, the conductors 10 and 20 run at the same depth either alongside one another or above one another. It may be useful for the conductors to be offset. Typical distances between the forward and return conductors 10 , 20 are 10 to 60 m, the conductors having an external diameter of 10 to 50 cm (0.1 to 0.5 m).
[0052] An electric two-conductor line 10 , 20 in FIG. 1 having the above-mentioned typical dimensions has a longitudinal inductance per unit length of 1.0 to 2.7 pH/m. The transverse capacitance per unit length, at the dimensions stated, lies at only 10 to 100 pF/m so that the capacitive transverse currents are initially negligible. Wave effects must be prevented. The wave velocity is given by the capacitance and inductance per unit length of the conductor arrangement.
[0053] The characteristic frequency of an inductor arrangement from FIG. 1 is determined by the loop length and the wave propagation velocity along the arrangement of the two-conductor line 10 , 20 . The loop length should therefore be chosen so as to be sufficiently short that no interfering wave effects are produced here.
[0054] FIG. 2 shows how four inductor pairs can be switched with a chronologically sequential current supply. 60 again designates the high-frequency power generator whose outputs are given to switching units 61 , 61 ′. The switching units 61 , 61 ′ each have four different contacts, the switching unit 61 being connected to four inductors 1 , 2 , 3 , 4 as the forward conductors and the switching unit 61 ′ being connected to four inductors 5 , 6 , 7 , 8 as return conductors. A switching clock 62 provides for the switching or connection of the generator voltage to the individual lines 1 to 8 .
[0055] The individual inductors 1 to 8 are arranged in accordance with FIG. 1 in the reservoir 100 . On both sides of the reservoir 100 there are areas 105 which are not to be heated and which phenomenologically represent the overburden. Furthermore a connection 15 is connected to the ends of the inductors which connects the forward and return conductors to one another. The connection 15 may be arranged above or below ground.
[0056] With the latter arrangement, it is possible for individual adjacent areas of the reservoir each to be heated in a controlled manner. This can, in particular, be carried out chronologically successively, i.e. sequentially. The switching clock 62 can be controlled by a separate control unit 63 which, in particular, takes into account the temperature T in the reservoir 100 . To this end, temperature sensors (not shown in FIG. 2 ) can, for example, be positioned on the individual inductors or inductor lines in order to measure local temperatures T i there and to transmit these to the control unit 63 for analysis. In this way, account can be taken, in particular, of excessive temperatures on the inductors.
[0057] It is, however, also possible to measure the temperatures locally at other points in the reservoir 100 or even in the overburden and/or underburden and to take these into account in the activation of the generators. An essential aspect here is that the power output of the generators can in this way be altered and adapted to the particular requirements which change in the phases of exploitation of the deposit over time. This applies in particular because the exploitation time phases are long, for example years or more.
[0058] In FIG. 3 , the arrangement according to FIG. 2 has been modified to the effect that four high-frequency power generators 60 ′, 60 ″, 60 ′″ and 60 ″″ are present, each of which controls two of the inductors 1 to 8 in pairs. An above-ground or below-ground connection 15 is again present. This arrangement makes it, in particular, possible to supply current at different current strengths and of different frequencies to four inductor pairs simultaneously.
[0059] An arrangement according to FIG. 3 can be modified such that different frequencies can also be used. This is shown in FIG. 4 , in which eight inductors 1 to 8 are again arranged parallel to one another in the reservoir. Two of the inductors 1 to 8 are in each case controlled by a separate generator 60 ′ to 60 ″″. In this case, generators are chosen such as generate differently predeterminable frequencies. For example, generator 60 ′ has the frequency f 1 , generator 60 ″ the frequency f 2 , generator 60 ′″ the frequency f 3 , generator 60 ″″ the frequency f 4 . The supply with currents of different frequencies means that the individual areas are now heated differently in a targeted manner.
[0060] With the aid of the examples, it has been shown that the heat output proportions in the overburden (OB), reservoir 100 and underburden (UB) can up to a point be influenced by means of a differentiated current supply to the inductors. These proportions are, in conclusion, reproduced for an example examined in detail:
[0061] a: If, for example, current is supplied to the inductors 1 to 5 , for example, a percentage loss distribution is obtained of:
[0062] OB 31.3%, reservoir 45.5% and UB 23.2%
[0063] b: If current is supplied simultaneously to all the inductors, the following is obtained by contrast:
[0064] OB 24.2%, reservoir 62.8% and UB 13.0%
[0065] The latter signifies that the greatest proportion of the heat output is deposited in the reservoir when current is supplied simultaneously to the inductors, with a phase shift of φ=180 between adjacent inductors. Switching between the types of current supply may therefore be advantageous depending on the chronological progress of exploitation of the deposit, in particular depending on the desired heat output distribution of the generators and/or on the number of generators used.
[0066] In conclusion, it should be pointed out that where the power generator is arranged outside the reservoir, an underground installation of the generator is also possible, which may under certain circumstances be advantageous. In this case, the electric power would then be conducted downward at low frequency, i.e. 50-60 Hz or possibly even as direct current, and conversion to the kHz range could possibly take place underground, so no losses would occur in the overburden.
[0067] It can be stated overall that the key electric parameters for heating the reservoir can be predetermined in a chronologically and/or spatially variable mamier and can be changed from outside the reservoir in order to optimize the extraction volume during the extraction of bitumen. At least one generator is present in the associated device, though multiple generators are preferred, the electric parameters (I, f i , φ) thereof being variable.
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A method for the “in situ” extraction of bitumen or very heavy oil is provided. An electric/electromagnetic heater to reduce the viscosity of bitumen or very heavy oil with at least two linearly expanded conductors are configured in a horizontal alignment at a predetermined depth of the reservoir. The conductors are connected to each other in an electrically conducting manner inside or outside of the reservoir, and together form a conductor loop, and are connected to an external alternating current generator outside of the reservoir for electric power. The heating of the reservoir is predetermined in a chronologically and/or locally variable manner in accordance with the electric parameters, and may be changed outside of the reservoir for optimizing the feed volume during the conveying of the bitumen. At least one generator is present in the related device, wherein the parameters thereof are variable for the electric power.
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BACKGROUND
The present invention relates generally to missile autopilots, and more particularly, to blended missile autopilots comprising a direct lift missile autopilot employing canards or side thrusters and a tail-controlled autopilot.
A tactical missile accelerates normal to its velocity vector in order to maneuver and hit an intended target. Guidance algorithms are used to determine the desired acceleration. An autopilot is then commanded to deliver that acceleration. The term autopilot refers to software and hardware dedicated to delivering the missile acceleration commanded by the guidance algorithms.
The objective of autopilot design is to deliver commanded acceleration as accurately and quickly as possible. Acceleration can be generated aerodynamically via lift, or less commonly, via thrusters oriented normal to the missile longitudinal axis. Aerodynamic autopilots fall into four basic categories. These include tail controlled autopilots, autopilots having fixed tails with movable wing surfaces, canard controlled autopilots, and autopilots having a combination of movable tails and canards.
Tail controlled autopilots have movable control surfaces (tails) located at the aft end of the body of the missile, aft of the center of gravity. The tails are used to generate pitching moments. As the body is pitched, the resulting angle of attack generates body lift, providing the desired acceleration. Fixed wings may be used forward of the tails for improved lifting capabilities.
In an autopilot having fixed tails with movable wings, the wings are located near the missile center of gravity. The wings are pitched to directly generate lift, while the body remains at low angles of attack, generating little lift. The fixed tail surfaces provide pitching moments which tend to restore the body to zero angle-of-attack.
Canard controlled autopilots operate in a manner similar to tail controlled autopilots. The canards are mounted forward of the center of gravity, and are used to generate pitching moments, and angle-of-attack of the body of the missile. Fixed wings mounted aft of the canards are used to generate lift.
With direct lift autopilots employing both movable tails and canards, the pitching moments from forward mounted canards are balanced against the pitching moments of the aft mounted tails.
Each autopilot type has distinct advantages. Where high acceleration capability is needed, autopilots employing body lift (tail or canard control) are desirable since the body is capable of generating significantly more lift than relatively small, movable control surfaces, thrusters, or canards. Where very fast response time is required, direct lift autopilots are desirable, since the control surfaces or thrusters can generate lift much faster than the body of the missile, and thus generate lift more quickly.
With regard to other prior art, it is known that several Soviet missile designs employ movable tails and canards, but nothing is known about the autopilot designs used therein.
Accordingly, it is an objective of the present invention to provide for improved blended missile autopilots comprising a direct lift missile autopilot employing canards or side thrusters and a tail-controlled autopilot.
SUMMARY OF THE INVENTION
To meet the above and other objectives of the present invention provides for blended missile autopilots that include a direct lift missile autopilot having canards or side thrusters coupled to a tail-controlled autopilot. The blended missile autopilots employ movable tails aft of the center of gravity of the missile and lateral force generating members comprising either side force thrusters or movable canards mounted forward of the center of gravity of the missile, and are controlled using direct lift and tail-controlled autopilots. Lift is generated from the tails and side force is generated by the thrusters or canards, such that the body of the missile maintains zero angle of attack and generates no lift. The present invention thus combines the fast response of a direct lift autopilot with the high acceleration capability of a body lift autopilot, and blends the two to achieve improved performance.
More particularly, the blended missile autopilot comprises a missile having a body that houses a plurality of rotatable tails aft of its center of gravity and a plurality of actuatable lateral force generating members forward of the center of gravity, and a plurality of controllable actuators coupled to the tails and lateral force generating members. A controller is coupled to the plurality of actuators that implements a predetermined transfer function comprising a tail controlled autopilot for controlling the tails and a direct lift autopilot for controlling the lateral force generating members. One key aspect of the present autopilot is that the direct lift autopilot is coupled to the tail controlled autopilot by means of a blending filter.
The present invention provides tactical missiles with extremely fast autopilot response while preserving high acceleration capability. In one embodiment, fast autopilot response is achieved using forward mounted thrusters oriented normal to the missile longitudinal axis in combination with aft mounted tail control surfaces. In a second embodiment, fast autopilot response is achieved using forward mounted aerodynamic control surfaces and actuators in combination with the aft mounted tail control surfaces. Because of missile packaging constraints and the desire to minimize weight, thruster propellant supply is limited, and is managed carefully during an engagement, and is optimally reserved for the final seconds prior to impact. Consequently, a tail controlled autopilot is employed in the present invention and provides control until the thrusters or canards are activated. Using thrusters or canards in the manner of the present invention allows the autopilots to be effective at higher altitudes than those that rely on aerodynamic control only.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIGS. 1a-1c illustrate conventional autopilot schemes that are useful in understanding the improvements provided by the present invention;
FIGS. 1d and 1e illustrate autopilot schemes in accordance with the principles of the present invention;
FIG. 2 shows a first embodiment of a blended direct lift, thruster and tail controlled autopilot in accordance with the principles of the present invention corresponding to the embodiment shown in FIG. 1d;
FIG. 3 shows the step response achieved by the conventional tail controlled autopilot of FIG. 1a;
FIG. 4 shows the step response achieved by the blended thruster and tail controlled autopilot of FIGS. 1d and 2;
FIG. 5 shows a second embodiment of a blended direct lift, canard and tail controlled autopilot in accordance with the principles of the present invention corresponding to the embodiment shown in FIG. 1e;
FIG. 6 shows a block diagram of an actuator model employed in the autopilot of FIG. 5 illustrating software position and rate limiters; and
FIG. 7 shows the step response achieved by the blended thruster and tail controlled autopilot of FIGS. 1e and 5.
DETAILED DESCRIPTION
Referring to the drawing figures, FIGS. 1a-1c illustrate conventional autopilots for a missile 11 that are useful in understanding the improvements provided by the present invention. FIG. 1a shows a conventional tail controlled autopilot 10 that comprises a controller 12 that controls the motion of tails 13 located aft of the center of gravity 16 of the missile 11. The relative motion (M) of the missile 11 about the center of gravity 16 due to forces (F) exerted by the body of the missile and tail 13 are also shown in FIG. 1a. FIG. 1b shows a conventional wing controlled autopilot that comprises a controller 12 that controls the motion of wings 13 located at the center of gravity 16 of the missile 11. The forces (F) exerted by the wings 14 are also shown in FIG. 1b. FIG. 1c shows a conventional canard controlled autopilot that comprises a controller 12 that controls the motion of canards 14 located forward of the center of gravity 16 of the missile 11. The relative motion (M) of the missile 11 about the center of gravity 16 due to forces (F) exerted by the body of the missile and canard 14 are also shown in FIG. 1c.
Referring to FIG. 1d, it illustrates a first embodiment of a blended missile autopilot in accordance with the principles of the present invention. The missile autopilot comprises a controller 12, a plurality of rotatable tails 13 mounted aft of the center of gravity of the missile 11, and a plurality of actuatable lateral force generating members comprising a plurality of thrusters 15 mounted forward of the center of gravity 16 of the missile 11. A plurality of controllable actuators 17 are coupled to the tails 13 and thrusters 15. The plurality of rotatable tails 13 and thrusters 15 are controlled by way of the actuators 17 using the controller 12. The controller 12 implements a predetermined transfer function to operate the actuators 17 as will be described below. Thus, the present autopilot comprises a tail controlled autopilot 21 for controlling movement of the tails 13 in combination with the direct lift autopilot 22 for controlling the plurality of thrusters 15.
FIG. 2 shows a detailed block diagram of a linearized closed loop transfer function for the blended missile autopilot of FIG. 1d. The tall-controlled autopilot 21 is enclosed in the dashed box shown in FIG. 2, and the direct lift autopilot and blending scheme in accordance with the principles of the present invention is the balance of FIG. 2. The designs of the tail-controlled autopilot 21, the direct lift autopilot 22, and the blending mechanism are discussed below.
The tail-controlled autopilot 21 operates to turn the tails 13 of the missile 11 to create pitching moment on the body of the missile 11, which generates missile angle-of-attack, resulting in lift. At the angle of attack where desired acceleration is achieved, the pitching moment generated by the tails 13 is equal and opposite to the pitching moment generated by the body of the missile 11, and the missile 11 is trimmed.
The linearized closed loop transfer function of the tail-controlled autopilot 21 is: ##EQU1## and s is the Laplace operator, K ss is a steady state gain correction term, α is angle-of-attack, δ(=δ T ) is tail deflection angle, q is dynamic pressure, S ref is aerodynamic reference area, d is an aerodynamic reference length, m is the mass of the missile 11, V m is velocity of the missile 11, I yy is pitch moment of inertia, C m α is moment derivative with respect to angle-of-attack, C n α is a normal force derivative with respect to angle-of-attack, C m δ is a moment derivative with respect to tail deflection, and C n δ is a normal force derivative with respect to tail deflection.
Gains K a , K b , and K.sub.θ are chosen to provide fast, well damped response. One suitable choice of closed loop poles (neglecting actuator effects) is:
p.sub.1,2 =-0.7ω±0.7ωj, and p.sub.3 =-0.7ω.
Equating coefficients with the desired closed loop transfer function: ##EQU2## where z is the z transform operator, and ω is the bandwidth of the autopilot 21. K a , K b , and K.sub.θ can be calculated: ##EQU3## Zeroes of the closed loop transfer function are not controlled. The bandwidth (ω) of the autopilot 21 is set as large as stability allows.
With reference to FIGS. 1d and 2, in the first embodiment of the present invention, the blended missile autopilot uses both tails 13 and thrusters 15 to generate force normal to the body of the missile 11, and balance opposing pitching moments, keeping the body of the missile 11 unrotated. The normal force is generated as fast as actuators for the tails 13 and thrusters 15 allow, much faster than the body of the missile 11 can rotate and produce lift, yielding an extremely fast autopilot. The tail-controlled autopilot 21 is used to control disturbance torques, such as those generated by wind gusts, or aerodynamic unbalances.
K TAIL is a proportionality constant between commanded thrust and the direct lift portion of the tall commands. K TAIL is calculated to balance pitching moments due to tails 13 and thrusters 15. ##EQU4## ∂ RCS is the normalized commanded thrust. The total direct lift acceleration is: ##EQU5## where T is the maximum available side thrust and L is the thruster moment arm. The tail deflection command provided by the direct lift autopilot 22 is summed with the deflection command of the tail-controlled autopilot tail 21 at location "A" in FIG. 2.
The blending mechanism used to transition from the direct lift autopilot 22 to the tail-controlled autopilot 21 is designed to take full advantage of the fast response of direct lift autopilot 22. The blending mechanism comprises the use of a blending filter coupled between the direct lift autopilot 22 and the tail-controlled autopilot 21. Normal force generated by the tails 13 and thrusters 15 is replaced by lift generated by the body of the missile 11 as fast as the tail-controlled autopilot 21 allows resulting in a smooth step response. The blending filter 24 also allows graceful degradation to the tail-controlled autopilot 21 when the commanded acceleration is greater than the tails 13 and thrusters 15 can deliver.
The autopilot blending mechanism implemented in the present invention is to command the direct lift autopilot 22 to deliver precisely the commanded acceleration less what the tail controlled autopilot 21 delivers. This is accomplished in open loop fashion using the blending filter 24 illustrated in FIG. 2. The blending filter 24 is a very precise model of the response of the tail-controlled autopilot 21. Location "B" in FIG. 2 indicates where the estimate of the acceleration derived from the tail-controlled autopilot 21 is subtracted from the total acceleration command, leaving the net direct lift acceleration command. The blending filter 24 is a digital implementation of the desired closed loop response of the tail-controlled autopilot 21 given by Equation (1) above. Both poles and zeroes are modeled.
An important innovation of this design is the feedforward of the direct lift acceleration command into the tail-controlled autopilot 21 shown at location "C" in FIG. 2. This causes the tail-controlled autopilot 21 to perform as if it is acting alone. Without feedforward of the direct lift acceleration command, the blending filter 24 could not properly match the response of the tail controlled autopilot 21, and the overall response of the autopilot would be degraded.
Linear, single plane simulation results for the first embodiment of the present invention are shown in FIGS. 3 and 4. FIG. 3 shows the step response for a conventional tail-controlled autopilot shown in FIG. 1a. Aerodynamics and flight conditions used are typical of ground and air launched tactical missiles 11. FIG. 4 shows the step response for the blended direct lift, tail-controlled autopilot 21 of FIGS. 1d and 2. Flight conditions are identical. Comparing the first graph in FIGS. 3 and 4, the benefits of direct lift are striking. The commanded acceleration is achieved in a fraction of the time required for the tail-controlled autopilot of FIG. 1a. The fourth, fifth, and sixth graphs indicate the contributions to total acceleration from tails 13, thrusters 15, and body of the missile 11. A smooth transition from tail/thruster lift to body lift is effected by the blending mechanism. The thrust level returns to zero (third graph) and the thrusters 15 are available for further maneuvers.
With reference to FIG. 5, in the second embodiment of the present invention is shown. The second embodiment is substantially the same as the first embodiment, but with differences as are described below. More particularly, FIG. 5 shows a blended direct lift, tail controlled autopilot corresponding to the embodiment shown in FIG. 1e. The second embodiment of the direct lift autopilot 21 uses tails 13 and canards 14 (actuatable lateral force generating members 14) to generate lift, and balance opposing pitching moments, keeping the body of the missile 11 unrotated. The lift from control surfaces (tails 13 and canards 14) is generated as fast as their actuators allow, yielding an extremely fast autopilot.
The equations for the basic transfer function for the second embodiment of the blended missile autopilot is as presented above with reference to FIG. 2. However, in this second embodiment, K tail is the proportionality constant between direct lift canard commands and the direct lift portion of the tail commands. K tail is calculated to balance pitching moments due to tails and canards.
K.sub.tail M.sub.δ =M.sub.δ.sbsb.C
δ=K.sub.tail δC
The direct lift acceleration is:
A.sub.DL =V.sub.m (N.sub.δ δ+N.sub.δ.sbsb.C δC)=V.sub.m (N.sub.δ K.sub.tail δ.sub.C +N.sub.δ.sbsb.C δC)
where ##EQU6## and δ C is the canard deflection angle, C m δ.sbsb.C is the moment derivative with respect to canard deflection, C n δ.sbsb.C is the normal force derivative with respect to canard deflection, and K C is the proportionality constant between direct lift acceleration and canard deflection: ##EQU7## The direct lift portion of the tail deflection command is summed with the tail-controlled autopilot tall deflection command at location "A" in FIG. 5.
The blending mechanism used to transition from the direct lift autopilot 22 to the tail-controlled autopilot 21 comprises the blending filter 24 that is coupled between the direct lift autopilot 22 and the tail-controlled autopilot 21. Lift generated by the tails 13 and canards 14 is replaced by lift generated by the body of the missile 11 as fast as the tail-controlled autopilot 21 allows resulting in a smooth step response. The blending filter 24 also allows graceful degradation to the tail-controlled autopilot 21 when commanded accelerations are greater than tail and canard lift can generate.
The implementation of autopilot blending is to command the direct lift autopilot 22 to precisely deliver the commanded acceleration less what the tail-controlled autopilot 21 delivers. This is accomplished in open loop fashion using the blending filter 24 illustrated in FIG. 5. Location "B" in FIG. 5 indicates where the estimate of the acceleration derived from the tail-controlled autopilot 21 is subtracted from the total acceleration command leaving the net direct lift acceleration command. The blending filter 24 is a digital implementation of the desired closed loop autopilot response given by Equation (1). Both poles and zeroes are modeled.
Feedforward of the direct lift acceleration command into the tail-controlled autopilot 21 at location "C" in FIG. 5 causes the tail-controlled autopilot 21 to perform as if it is acting alone. Without the feedforward, the blending filter 24 could not properly match the tail controlled response, and the overall response of the autopilot would be degraded.
For the direct lift autopilot 22 to generate lift without pitching the missile 11, the proportionality relationship,
δ.sub.T =K.sub.tail δ.sub.C
must be maintained throughout the angular excursion of the tails 13 and canards 14. This means that any angular position limits, either hardware constraints or aerodynamic effectiveness constraints, imposed on one set of control surfaces, must be imposed on the other set. Assuming that the canards 14 reach their limit first,
[δ.sub.T ].sub.LIM =K.sub.tail [δ.sub.C ].sub.LIM.
This limit applies to the direct lift portion of the tail command only. Similarly, rate limits imposed on one set of control surfaces (tails 13 and canards 14) must be applied to the other set in proportion:
[δ.sub.T ].sub.LIM =K.sub.tail [δ.sub.C ].sub.LIM.
FIG. 6 shows a block diagram of an actuator model employed in the controller 12 of the autopilot of FIG. 5 illustrating software position and rate limiters.
FIG. 7 shows simulation results from a linear single plane simulation similar to those shown in FIGS. 3 and 4. FIG. 7 shows a step response for the blended direct lift, tail-controlled autopilot at flight conditions identical to those of FIGS. 3 and 4. Aerodynamics have been modified to include canard effects. Comparing the first graphs of FIGS. 3 and 7, the benefits of direct lift are clear. The commanded acceleration is achieved in a fraction of the time required for the tail-controlled configuration. The fourth, fifth, and sixth charts indicate the contributions to total acceleration from tails 13, canards 14, and body of the missile 11. A smooth transition from tail/canard lift to body lift is effected by the blending filter 24. Canard angle deflections are returned to zero (third graph) and the canards 14 are available for further maneuvers.
Thus, new and improved blended missile autopilots comprising a direct lift missile autopilot to control canards or side thrusters and a tail-controlled autopilot to control tails have been disclosed. It is to be understood that the described embodiments are merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.
|
Blended missile autopilots for a missile employing direct lift and tail controlled autopilots coupled by way of a blending filter. The blended missile autopilots have movable tails aft of the center of gravity of the missile and side force thrusters or movable canards mounted forward of the center of gravity, and that are controlled using the direct lift and tail-controlled autopilots. Lift is generated from the tails and side force is generated by the thrusters or canards, such that the body of the missile maintains zero angle of attack and generates no lift. The present invention thus combines the fast response of a direct lift autopilot with the high acceleration capability of a body lift autopilot, and blends the two using the blending filter to achieve improved performance.
| 5
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RELATED APPLICATION INFORMATION
This application claims priority to provisional application Ser. No. 61/439,401 filed on Feb. 4, 2011, incorporated herein by reference.
BACKGROUND
1. Technical Field
The present invention relates to wavelength-division multiplexing (WDM), and more particularly to routing, wavelength assignment, and spectrum allocation in wavelength convertible flexible optical WDM networks.
2. Description of the Related Art
In International Telecommunication Union, Telecommunication Sector (ITU-T) standardized fixed grid networks, a fixed amount of spectrum (50 GHz) is allocated to every channel irrespective of the operating line rate, and the center frequency of a channel remains fixed. FIG. 1 shows the fixed channel spacing 100 of a fixed grid wavelength-division multiplexing (WDM) network. Such a fixed channel grid may not be sufficient to support immerging super-channels which operates at 400 Gb/s or 1 Tb/s line rates. For example, 50 GHz of spectrum is not sufficient for 400 Gb/s and 1 Tb/s channels which require 75 GHz and 150 GHz of spectrum, respectively. On the other hand, supporting such super-channels by increasing the channel spacing in fixed grid networks may not optimize the spectrum allocation for channels operating at lower line rates. For example, a 10 Gb/s channel only requires 25 GHz of spectrum. Thus, no single fixed channel grid is optimal for all line rates.
There has been growing research on optical WDM systems that is not limited to a fixed ITU-T channel grid, but offers a flexible channel grid to increase spectral efficiency. We refer to such grid-less WDM networks as flexible optical WDM networks (FWDM). In FWDM networks, a flexible amount of spectrum is allocated to each channel, and the channel center frequency may not be fixed. FIG. 2 shows the flexible channel spacing 200 of a flexible optical wavelength-division multiplexing network (FWDM). Thus, while establishing a channel in FWDM networks, a control plane must follow (1) the requirement of having the same operating wavelength on all fibers along the route of a channel which is referred to as the wavelength continuity constraint, (2) the requirement of allocating the same amount of spectrum on all fibers along the route of a channel which is referred to as the spectral continuity constraint, and (3) the requirement of allocating non-overlapping spectrum with the neighboring channels in the fiber which is referred to as the spectral conflict constraint. The problem of finding a channel satisfying these constraints is referred to as the routing, wavelength assignment, and spectrum allocation (RWSA) problem.
Due to wavelength continuity, spectral continuity, and spectral conflict constraints, a channel may not be established even though there is sufficient amount of spectrum available on all fibers along the route. Wavelength and spectral conflicts between different fibers can be resolved by employing wavelength converters at nodes which can convert the wavelength on the incoming fiber to an available wavelength on the outgoing fiber at which sufficient spectrum is available. Thus, wavelength converters can improve the channel blocking probability. FWDM networks with wavelength converters are referred to as wavelength convertible FWDM networks.
One of the open problems in wavelength convertible FWDM networks is as follows: for a given configuration of the optical network in terms of the location of optical nodes and deployed fibers connecting optical nodes, the number of wavelength converters at each optical node, the wavelength conversion range of each wavelength converter, the set of line rates offered by the network and the respective spectrum requirement, the problem is how to find a channel operating at the requested line rate in the wavelength convertible FWDM network such that the blocking probability of a channel is minimized. Finding a channel in FWDM networks involves sub-problems such as how to route the channel, how to assign a wavelength to the channel, and how to allocate the required spectrum to the channel. Together the problem is referred to as the routing, wavelength assignment, and spectrum allocation in wavelength convertible FWDM networks (RWSA-WC).
If we restrict the spectrum allocation to every channel to be fixed, then the problem is transformed into the routing and wavelength assignment (RWA-WC) problem in wavelength convertible fixed grid networks. However, existing methods directed to the RWA-WC problem are not applicable to the RWSA-WC problem due to the additional spectral continuity and spectral conflict constraints.
Existing solutions of the RWSA problem are applicable to the RWSA-WC problem. However, existing RWSA solutions suffer from higher blocking probability because these solutions are not able to take advantage of wavelength converters. Accordingly, there is no existing solution addressing the RWSA-WC problem in FWDM networks.
SUMMARY
These and other drawbacks and disadvantages of the prior art are addressed by the present principles, which are directed to routing, wavelength assignment, and spectrum allocation in wavelength convertible flexible optical wavelength-division multiplexing (WDM) networks.
According to an aspect of the present principles, there is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a plurality of optical nodes interconnected by a plurality of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one of the plurality of optical nodes has at least one wavelength converter for wavelength conversion. The method includes determining a channel route through the network commencing at a source node and ceasing at a destination node. The determined channel route is selectively tunable responsive to selected ones of a plurality of routing methods. The selected ones of the plurality of routing methods are so selected responsive to a routing policy having one or more objectives of minimization of a blocking of one of more channels in the set, minimization of a number of wavelength converters used in the network, minimization of physical distance traversed by a channel between a source node and a destination node, and minimization of operating wavelengths of a channel.
According to another aspect of the present principles, there is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a set of optical nodes interconnected by a set of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one of the optical nodes in the set has at least one wavelength converter for wavelength conversion. The method includes constructing an auxiliary graph having a set of auxiliary nodes. Each of the auxiliary nodes corresponds to a respective one of the optical nodes in the set of optical nodes. The auxiliary graph further has a set of auxiliary links. Each of the auxiliary links corresponds to a respective one of the optical fibers in the set of optical fibers. The method further includes determining a subset of auxiliary links that support an amount of the spectrum specified for a given channel. The method additionally includes searching the subset of auxiliary links to select one or more auxiliary links in the subset that minimize a channel blocking probability.
According to yet another aspect of the present principles, there is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a plurality of optical nodes interconnected by a plurality of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one of the plurality of optical nodes has at least one wavelength converter for wavelength conversion. The method includes performing an incremental search on a subset of consecutive wavelength slots in the set starting at a given slot in the subset having a lowest wavelength corresponding thereto. The method further includes terminating the incremental search when a particular one of the consecutive wavelength slots in the subset is available on each of the plurality of nodes. The method additionally includes establishing a channel using the particular one of the consecutive wavelength slots. The establishing step includes determining a route for the channel by selecting a node along the route from among multiple candidate nodes responsive to node parameters and respective priorities of the node parameters.
These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
The disclosure will provide details in the following description of preferred embodiments with reference to the following figures wherein:
FIG. 1 shows the fixed channel spacing 100 of a fixed grid wavelength-division multiplexing (WDM) network;
FIG. 2 shows the flexible channel spacing 200 of a flexible optical wavelength-division multiplexing network (FWDM);
FIG. 3 is a block diagram illustrating an exemplary processing system 300 to which the present principles may be applied, according to an embodiment of the present principles;
FIG. 4 shows a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network architecture 400 , in accordance with an embodiment of the present principles; and
FIG. 5 is a flow diagram showing an exemplary method for tunable routing, wavelength assignment, and spectrum allocation in a WC-FWDM network, according to an embodiment of the present principles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As noted above, the present principles are directed to routing, wavelength assignment, and spectrum allocation in wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) networks. Advantageously, the present principles address and overcome the aforementioned routing, wavelength assignment, and spectrum allocation in WC-FWDM networks (RWSA-WC) problem.
In an embodiment, the present principles address routing, wavelength assignment, and spectrum allocation sub-problems at the same time using an auxiliary graph based method. Additionally, the solution for the routing sub-problem is tunable to various methods. Thus, the proposed approach may be interchangeable referred to herein as the tunable routing, wavelength assignment, and spectrum allocation approach.
Again referring to existing solutions to the routing, wavelength assignment, and spectrum allocation (RWSA) problem, as noted above, the same may still block connections due to the wavelength continuity, spectral continuity and spectral conflict constraints. To increase efficiency, in an embodiment, we propose a wavelength-convertible FWDM network (WC-FWDM) in which wavelength converters are employed at intermediate switching ROADM nodes. Of course, the present principles are not limited to ROADM nodes and, hence, other types of optical nodes may also be used as readily contemplated by one of ordinary skill in the art given the teachings of the present principles provided herein, while maintaining the spirit of the present principles. A wavelength converter can change the wavelength of a transit connection from any incoming wavelength to any arbitrary wavelength. Thus, wavelength conflicts along the route of a channel can be resolved, and utilization of spectral resources can be increased.
Referring now in detail to the figures in which like numerals represent the same or similar elements and initially to FIG. 3 , a block diagram illustrating an exemplary processing system 300 to which the present principles may be applied, according to an embodiment of the present principles, is shown. Such a processing system 300 may be used to implement various methods in accordance with the present principles. The processing system 300 includes at least one processor (CPU) 302 operatively coupled to other components via a system bus 304 . A read only memory (ROM) 306 , a random access memory (RAM) 308 , a display adapter 310 , an I/O adapter 312 , a user interface adapter 314 , and a network adapter 398 , are operatively coupled to the system bus 304 .
A display device 316 is operatively coupled to system bus 304 by display adapter 310 . A disk storage device (e.g., a magnetic or optical disk storage device) 318 is operatively coupled to system bus 304 by I/O adapter 312 .
A mouse 320 and keyboard 322 are operatively coupled to system bus 304 by user interface adapter 314 . The mouse 320 and keyboard 322 are used to input and output information to and from system 300 .
A (digital and/or analog) modem 396 is operatively coupled to system bus 304 by network adapter 398 .
Of course, the processing system 300 may also include other elements (not shown), as readily contemplated by one of skill in the art.
WC-FWDM Network Architecture
The WC-FWDM network architecture includes the following four key features: (1) dynamic allocation of network resources; (2) dynamic provisioning of connections; (3) an automated control plane; and (4) wavelength conversion capability.
Resource allocation in the WC-FWDM network is flexible and dynamic. The WC-FWDM architecture can establish channels operating at the requested data rates, and thus, minimizes stranded channel capacity in the network. Additionally, these channels are established by allocating an optimum amount of spectrum using advance modulation schemes. Such channels are referred to as flexible channels. Thus, the WC-FWDM network architecture increases spectral utilization of the network. Flexible channels in WC-FWDM networks may be static or may be adaptive to dynamic traffic. The line rate and spectrum of an adaptive channel can be changed over time to support time varying traffic demands. Such flexible adaptive channels can be realized using variable rate transponders, which can use an OFDM based modulation scheme with variable subcarrier assignment or use a single carrier modulation scheme with switchable modulation stages and variable rate data multiplexer to adjust the line rate according to traffic demand.
The WC-FWDM architecture provides dynamic provisioning of connections through spectrum-variable colorless, directionless, and contentionless multi-degree ROADM nodes. Similar to fixed grid networks, the multi-degree ROADM nodes have colorless and directionless features so that adding/dropping of connections are not restricted to a specific wavelength or transponder, and the connections can be flexibly routed to any direction. Furthermore, both of these features are achieved without incurring wavelength contention at nodes by using optical demultiplexers with large scale fiber switches, or wavelength-selective switch (WSS)-based ROADM sub-modules with wavelength aggregators. In the FWDM network, the demultiplexers and WSS's are spectrum-variable by using switching technologies with small pixels, such a liquid crystal on silicon (LCoS) or digital micro electro mechanical systems (MEMS), to obtain finer switching granularity and to perform adding/dropping/cross-connecting with different passband widths.
Channels in a WC-FWDM network can be set up, torn down, and managed by an automated control plane in which an existing generalize multi-protocol label switching (GMPLS) control plane is modified by incorporating channel width and operating frequency related parameters or establishing channels (lambda paths) at a subcarrier granularity.
The wavelength conversion function of the FWDM network is also performed in the ROADM node. There are several options for positioning wavelength converters in the ROADM node, as illustrated in the example of FIG. 5 .
FIG. 4 shows a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network architecture 400 , in accordance with an embodiment of the present principles. The WC-FWDM network architecture 400 includes an automated control plane 410 , incoming optical fibers 420 , separators (seps) 431 , a fiber cross-connect (OXC) 432 , a bank 440 of wavelength converters with full-wavelength conversion capability, a bank 450 of wavelength converters with sparse wavelength conversion capability, a bank 460 of transponders, and outgoing optical fibers 480 .
In the example of FIG. 4 , the FWDM optical signals from the incoming fibers 420 are first demultiplexed using FWDM channel separators 431 . A separator 431 can be realized by using a spectrum variable wavelength selectable switch (WSS). Each separated wavelength is switched to its respective output port using a fiber cross-connect 432 . Each output port of the fiber cross-connect 432 includes a dedicated wavelength converter ( 440 , 450 , and/or 460 , so that the wavelength at the output port may be changed dynamically. Finally an optical combiner 470 is used to multiplex the FWDM channels onto each outgoing optical fiber 480 . The combiner 470 can be realized by using a passive optical coupler.
If d is the outbound degree of a node, Y is the total optical spectrum, and l is the minimum required spectrum by a channel, then the WC-FWDM architecture requires
d ⌈ Y l ⌉
wavelength converters. This architecture is referred to as WC-FWDM with full wavelength conversion capability (Option A, i.e., 440 in FIG. 4 ).
In the case of availability of the same wavelength at the outbound fiber 470 as at the inbound fiber 420 , a transit connection does not require a wavelength converter. Thus, full wavelength conversion may not be a cost efficient approach. An alternative solution is to use a wavelength converter bank 450 in which wavelength converters are shared between transit connections over time. The connections that need wavelength conversion are switched by the fiber cross-connect 432 to a wavelength converter in the bank 450 instead of switching them to output ports, and after wavelength conversion, these connections are sent back to input ports of the fiber cross-connect 432 which switches them to the appropriate output ports. This architecture is referred to as WC-FWDM with sparse wavelength conversion (Option B, i.e., 450 in FIG. 4 ). Sparse wavelength conversion can be provided by using a limited number of converters at each node, or wavelength converters with limited range conversion capability, or a few nodes with wavelength conversion capability.
Another alternative is to drop the channels that require wavelength conversion at the node and to use back-to-back transponders 460 to change the wavelengths before adding them back to the node (Option C, i.e., 460 in FIG. 4 ).
Wavelength conversion using back-to-back connection of a transponder pair requires O-E-O conversion which affects the transparency of the signal and creates bottlenecks in the transmission speed. Additionally this technique is not power efficient. Optical wavelength conversion can be realized using techniques such as optical gating and wave-mixing. In particular, the wave mixing techniques, such as four-wave mixing using semiconductor amplifiers and difference frequency generation in periodically poled LiNbO 3 waveguides and semiconductor waveguides, allow transparency of the signals and allow the simultaneous conversion of multiple channels.
RWSA-WC
Given the WC-FWDM network, total optical spectrum, and arrival and connection holding time distributions of traffic demands, the problem is how to accommodate each traffic demand in the network such that connection blocking probability is minimized. The problem is referred to as the routing, wavelength assignment, and spectrum allocation problem in wavelength convertible FWDM networks (RWSA-WC). If the given network is a fixed grid network, then the problem is transformed into the routing and wavelength assignment problem with wavelength conversion (RWA-WC). The RWSA-WC problem considers allocation of an additional parameter, spectrum, as compared to the existing RWA-WC problem in fixed grid networks. The RWSA-WC problem can formally be defined as follows.
We are given a physical topology G(V,E), where V is a set of optical nodes (e.g., but not limited to ROADM nodes) and E is a set of fibers connecting the optical nodes. Each node i includes a number C i wavelength converters. The total network spectrum is Y GHz. The conversion range of a wavelength converter is ±M GHz. That means a wavelength converter is capable of converting an input wavelength w to any wavelength within (w−M) and (w+M). For example, M=Y indicates that an incoming wavelength can be converted to any outgoing wavelength. The WC-FWDM network supports a set of line rates L. For example, L={10 Gb/s, 40 Gb/s, 100 Gb/s, 400 Gb/s, 1 Tb/s}. A traffic demand requesting a connection between source s and destination d operating at line rate l i εL is denoted as R(s,d,l i ). Arrival and connection holding time distributions of traffic demands are given. Each line rate l i εL requires a spectral width of x l i GHz. For example, 100 Gb/s line rate requires 50 GHz of spectrum. We assume that the transponders are tunable. The goal of the problem is to find a set of lightpaths for traffic demands such that the connection blocking probability is minimized. For each lightpath, we must find the route of a lightpath over the physical topology, assign a wavelength, and allocate sufficient amount of spectrum to support the requested line rate. We assume that the transponders are wavelength tunable, and the optical network is ideal.
Routing, Wavelength Assignment, and Spectrum Allocation Method for WC-FWDM Networks
We prove the hardness of the RWSA-WC problem by mapping it to the well known RWA problem in fixed grid networks, we describe the proposed method, and we evaluate the complexity of the proposed heuristic.
Theorem 1: The RWSA-WC problem is NP-Complete.
Proof If we restrict the number of converters at each node to be zero, C i =0, then the RWSA-WC problem is transformed into the RWSA problem in the FWDM network. For a given identical spectral width of each line rate, x l i =x l j , ∀i,j, the RWSA problem in the FWDM network is transformed into the RWA problem in the mixed line rate fixed grid networks, and finally for the offered single line rate, |L|=1, the RWA problem in mixed line rate systems is reduced to the RWA problem in single line rate fixed grid WDM networks. Since the RWA problem, which is the constrained version of the RWSA-WC problem, is an NP-Complete problem, the RWSA-WC problem is also an NP-Complete problem.
We propose the first practical solution of the RWSA-WC problem referred to as the routing, wavelength assignment, and spectrum allocation method. In order to reduce the complexity of the problem, we assume that the spectrum is slotted in the frequency domain. Each slot is referred as a wavelength slot, and has a spectral width of δ GHz. The index of a wavelength slot is denoted as
w ∈ { 1 , 2 , 3 , … ⌈ Y δ ⌉ } .
The spectrum can also be defined in terms of the number of consecutive wavelength slots. The lowest index of the allocated wavelength slots to a channel is referred to as the wavelength of the channel. In a fiber, a wavelength slot can either be in an occupied state or be in an available state. The state information of a wavelength slot w in a fiber (i,j) is referred to as the spectrum availability information, which is denoted as G ij w ε{0,1}. G ij w =1 indicates that a wavelength slot w is available and G ij w =0 indicates that a wavelength slot w is occupied by a channel.
In an embodiment, the proposed method can be implemented using an auxiliary graph based approach. Of course, given the teachings of the present principles provided herein, the method can be readily constructed and/or otherwise modified into other forms while maintaining the spirit of the present principles. The following pseudo code of METHOD 1 is used to find a set of available wavelength slots and to construct an auxiliary graph.
METHOD 1: RWSA-WC (G(V,E), C i , H sd , R(s, d, l i ), x li )
comment: Find a set of available wavelength slots
for
w
←
0
to
⌈
Y
δ
⌉
do
{
for
∀
(
i
,
j
)
∈
E
{
it
←
1
for
k
←
0
to
⌈
x
l
i
δ
⌉
do
{
if
G
ij
w
+
k
×
it
=
1
then
it
←
1
else
it
←
0
if
it
=
1
then
W
ij
←
W
ij
⋃
{
w
}
for
∀
(
i
,
j
)
∈
E
{
if
w
∈
W
ij
then
exit
done = false
repeat
{
comment
:
Construction
of
an
auxiliary
graph
N
=
V
for
∀
(
i
,
j
)
∈
E
{
if
W
ij
>
0
then
(
i
,
j
)
∈
A
{
PATH
,
WL
}
=
Method
2
(
G
′
(
N
,
A
)
,
R
(
s
,
d
,
l
i
)
,
H
sd
,
ρ
,
M
)
if
PATH
≤
f
(
ρ
,
H
sd
)
then
done
=
true
else
W
ij
←
W
ij
-
{
min
(
w
)
❘
w
∈
W
ij
,
∀
(
i
,
j
)
∈
E
}
comment
:
Remove
the
minimum
wavelength
slot
from
all
sets
until done = false and |w ij | = 0, ∀(i, j)∈ EA
if done=true
then return (PATH, WL)
else Block the Request
The pseudocode of METHOD 1 first finds a set of wavelength slots W ij starting from which
⌈ x l i δ ⌉
consecutive wavelength slots are available in the spectrum availability information G ij w of each link (i,j)εE. The search of these wavelength slots is started from the lowest wavelength slot, and terminated when a wavelength slot w is available on every link (i,j), wεW ij , ∀(i,j)εE. In the second step, based n the found sets of wavelength slots, the method constructs an auxiliary graph G′(N,A), where N represents a set of auxiliary nodes and A represents a set of auxiliary links. A set of auxiliary nodes N is the same as the set of physical (i.e., optical) nodes V. An auxiliary link (i,j) is established if at least one wavelength slot is available on the fiber (i,j), W ij ≠ø, that is if the set of wavelength slots W ij is not empty.
After constructing an auxiliary graph, a route connecting source and destination nodes are found as follows according to the pseudo code of METHOD 2.
METHOD 2: ({acute over (G)} (N, A), R (s, d, l i ), H sd , ρ, M)
comment: Initialization of node parameters
for ∀i ∈ N{p i ← ∞, a i ← ∞, t i ← 0, r i ← 0, h i ← ∞
h s ← 0
Q ← φ
repeat
{
comment
:
Select
a
node
based
on
priority
u
←
{
i
❘
(
1
)
min
(
h
i
)
,
(
2
)
min
(
r
i
)
,
(
3
)
min
(
t
i
)
,
∀
i
∈
(
N
-
Q
)
}
Q
←
Q
⋃
{
u
}
for
∀
j
∈
Adj
(
u
)
and
j
≠
Q
{
comment
:
Update
the
node
parameters
of
neighboring
nodes
if
u
=
s
then
{
if
h
u
+
1
<
h
j
then
{
Update
(
)
r
j
←
0
else
{
if
a
u
=
{
min
(
w
)
❘
w
∈
W
uj
}
then
{
if
h
u
+
1
<
h
j
then
{
Update
(
)
r
j
←
r
u
else
if
h
u
+
1
=
h
j
then
{
if
r
u
<
r
j
then
{
Update
(
)
r
j
←
r
u
else
if
r
u
=
r
j
then
{
if
max
(
t
u
,
{
min
(
w
)
❘
w
∈
W
uj
}
)
<
t
j
then
{
Update
(
)
r
j
←
r
u
else
if
a
u
-
M
≤
{
min
(
w
)
❘
W
uj
}
≤
a
u
+
M
and
C
u
>
0
then
{
if
h
u
+
1
<
h
j
then
{
Update
(
)
r
j
←
r
u
+
1
else
if
h
u
+
1
=
h
j
then
{
if
r
u
+
1
<
r
j
then
{
Update
(
)
r
j
←
r
u
+
1
else
if
r
u
+
1
=
r
j
then
{
if
max
(
t
u
,
{
min
(
w
)
❘
w
∈
W
uj
}
)
<
t
j
then
{
Update
(
)
r
j
←
r
u
+
1
until (N − Q) ≠ φ
comment: Obtain routing, wavelength assignment information
u ← d
repeat
PATH ← PATH ∪ {p u }
WL ← WL ∪ {a u }
u ← p u
until u ≠ ∞
One node at a time is added to the covered set of nodes based on the physical distance of a node from the source node, the number of wavelength converters required to reach a node from the source node, and the maximum available wavelength along a route connecting a node to the source node. The method starts with Q as a set of visited nodes. Initially, Q is an empty set. For each node uεN, five pieces of information (referred to herein as node parameters) are maintained, physical distance in terms of number of hops h u from the source node, wavelength at the input port a u , maximum wavelength along the route from the source node t u , the number of required wavelength converters along the route from the source node r u , and predecessor node p u . Initially, a u =∞, t u =0, r u =0, and p u =∞ for all uεN, h u =∞ for all uεN−{s}, and h s =0.
The method repeatedly selects a vertex u from the set N−Q, which has the lowest physical distance h u , and adds this node to set Q. In case of a tie, a node with the minimum number of converters r u along the route from the source node is selected. If the physical distance h u and the number of required wavelength converters r u are the same, then the tie is resolved by selecting a node with the minimum wavelength along the route t u along the route from the source node.
In the next step, the method updates the node parameters of adjacent nodes jεAdj(u), j∉Q, where Adj(u) represents a set of adjacent nodes of node u. The node parameters of a neighboring node are only updated if the neighboring node is either reached with the wavelength continuity constraint or in case of wavelength conflicts, node u has sufficient number of wavelength converters and the wavelength at the input port is convertible to an available wavelength at the output port. If any node parameter of the neighboring node is improved, then based on a priority of a parameter, all other parameters are updated. In an embodiment, the first priority is given to the physical distance h j . If h j is improved, then all other parameters are updated. In the case of a tie, in an embodiment, the second priority is given to the required number of wavelength converters r j . Hence, the node parameters are updated if the number of employed converters along the route r j is improved. In the case of having the same physical distance h j and the same number of required wavelength converters r j , then in an embodiment the third priority is given to the minimum available wavelength t j .
The same procedure is repeated until N−Q=ø. At last, the predecessor information p u includes the routing information, the wavelength at the input port a u includes the wavelength assignment information, and
⌈ x l i δ ⌉
is the spectrum allocation information. Thus, the proposed method solves the routing, wavelength assignment, and spectrum allocation subproblems at the same time and improves the network optimization.
The found RWSA solution is only acceptable if it satisfies certain criteria based on the route length, the number of converters, and the set of wavelengths along the route. Here, the method accepts the solution if the route length is less than f(ρ, H sd ), which represents the acceptable route length as a function of network load ρ and the shortest physical distance between source and destination nodes H sd .
f (,ρ, H sd )= H sd (1)
f (ρ, H sd )= H sd +∞ (2)
f (ρ, H sd )= H sd +((1−ρ)× H sd ) (3)
f (ρ, H sd )= H sd +(10 −ρ ×H sd ) (4)
The function in Equation (1) restricts the routing of traffic demands on the physical shortest paths, which is referred to as shortest path approach, while the function in Equation (2) does not restrict the length of a route. Thus, the routing of a traffic demand adapts based on the current network state, and greedily selects the shortest route among the available routes at lower wavelengths. This approach is referred to as the pure-adaptive approach. As is known a greedy method is any method that follows the problem solving heuristic of making the locally optimal choice at each stage with the hope of finding the global optimum. The functions in Equations (3) and (4) restrict the path length based on the current network load. Both of these approaches reduce the acceptable length of a route as the network load increases. Thus, at lower network load, both approaches behave like the pure-adaptive approach, and at higher network load, they behave like the shortest path approach. In Equation (3), the acceptable length of a route decreases linearly, which is referred to as the linear-load-adaptive approach, while in Equation (4), the acceptable length of a route decreases exponentially, which is referred to as the exponential-load-adaptive approach.
If the physical distance of the route is higher than f(ρ, H sd ), then the solution is rejected, and the minimum available wavelength slot w in the entire network is removed from all sets of wavelength slots W ij , ∀(i, j)εE. The process is repeated until either a route is found whose physical distance is less than f(ρ, H sd ) or all sets of wavelength slots W ij , ∀(i, j)εE are empty.
The proposed method is also applicable to the RWSA and RWA problems with/without wavelength conversion.
In the pseudocode, it and done are iterators. PATH is a set of nodes along the route, and WL is a set of wavelengths along the route starting from which at least x l i amount of spectrum is available.
Theorem 2: The tunable routing, wavelength assignment, and spectrum allocation heuristic is a polynomial-time method.
Proof. For the given wavelength convertible FWDM network G(V,E) and Y GHz of optical spectrum, if the spectrum is slotted by δ GHz, then the amount of time required to find wavelength slots starting from which x l i amount of spectrum is available is
O ( ⌈ Y δ ⌉ ⌈ x li δ ⌉ E ) .
The time required to construct an auxiliary graph G′(N,A) is O(|E|). After constructing an auxiliary graph the time required to solve the routing, wavelength assignment, and spectrum allocation subproblem using METHOD 2 above is O(|N|lg|N|+|A|). The procedure of constructing an auxiliary graph and solving the subproblems through METHOD 2 above is repeated
⌈ Y δ ⌉
times in the worst case. Thus, the time complexity of the tunable routing, wavelength assignment, and spectrum allocation problem is
O ( ⌈ Y δ ⌉ ( ⌈ x li δ ⌉ E + N lg N + A ) ) ,
which is polynomial.
METHOD 3: Update(—)
comment: Update node parameters
h j ← h u +1
p j ← u
a j ← {min(w)|w∈ W uj
t j ← max{t u ,{min(w)|w∈ W uj }}
The preceding will now be further described with respect to FIG. 5 . FIG. 5 is a flow diagram showing an exemplary method for tunable routing, wavelength assignment, and spectrum allocation in a WC-FWDM network, according to an embodiment of the present principles.
At step 501 , the first wavelength slot w=1 is initialized and considered. At step 502 , a search is performed on
⌈ x l i δ ⌉
number of consecutive wavelength slots starting from the wavelength slot w on fiber (i, j). If
⌈ x l i δ ⌉
consecutive wavelength slots are available, then the method proceeds to step 503 . Otherwise, the method proceeds to step 504 .
At step 503 , wavelength slot w is included into the set of available wavelength slots W ij . At step 504 , wavelength slot w is not included into the set of available wavelength slots W ij .
At step 505 , it is verified whether all fibers (i, j)εE are checked for the availability of
⌈ x l i δ ⌉
number of consecutive wavelength slots. If any fiber is still left for the consideration, then the method proceeds to step 506 . Otherwise, the method proceeds to step 507 .
At step 506 , a fiber (i, j)εE is selected which is not yet taken into consideration and the method returns to step 502 . At step 507 , it is checked whether or not the wavelength slot w is available on every fiber (i, j,) i.e., W j , ∀(i, j)εE or
w = ⌈ Y δ ⌉ .
If it is available, then the method proceeds to step 509 . Otherwise, the method proceeds to step 508 .
At step 508 , the index of the wavelength slot w is incremented, and the method returns to step 502 . At step 509 , a set of auxiliary nodes N is constructed from the set of optical nodes V, i.e., N=V.
At step 510 , the number of available wavelength slots on a fiber (i, j) is checked, i.e., |W i,j |>0. If at least one wavelength slot is available, then the method proceeds to step 511 . Otherwise, the method proceeds to step 512 .
At step 511 , an auxiliary link (i, j) in G′(N, A) is established between auxiliary nodes i and j. At step 512 , no auxiliary link is established between auxiliary nodes i and j in G′(N, A).
At step 513 , it is checked whether the set of available wavelength slots for each fiber (i,j)εE is considered. If any fiber is still left, then the method proceeds to step 514 . Otherwise, the method proceeds to step 515 .
At step 514 , a fiber (i,j)εE is selected which is not yet taken into account and the method returns to step 510 . At step 515 , the following are initialized: p i =∞, a i =∞, t i =0, r i =0, h i =∞∀iεN, h s =0, and Q=Ø.
At step 516 , a node u is found from the set N−Q which has the minimum h u value, and this node is added into set Q. In case of conflicts (e.g., ties), a node is selected that has the minimum r u . If h u and r u are the same, then a node that has the minimum t u is selected.
At step 517 , the neighboring node of the node u which does not exist in set Q is found, i.e., jεAdj(u)−Q. At step 518 , it is checked whether or not the found node u is the source node, i.e., u=s. If u is the source node, then the method proceeds to step 519 . Otherwise, the method proceeds to step 521 .
At step 519 , it is checked whether the distance to neighboring node j from the source node s routed directly from node s is less than the distance to neighboring node j from the source node s routed through any other node, i.e., h u +1<h j . If the distance routed directly from node s is less than that of routed through any other node, then the method proceeds to step 520 . Otherwise, the method returns to step 517 .
At step 520 , the following are updated, with the method thereafter proceeding step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to 0; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 521 , if node u is an intermediate node, then this step checks the requirement of the wavelength continuity between the wavelength at the input port of a node u, a u , and the minimum wavelength in the set of available wavelength slots W uj . If the wavelength continuity is satisfied, then the method proceeds to step 522 . Otherwise, the method proceeds to step 530 .
At step 522 , it is checked whether the distance to neighboring node j from the source node s routed through node u is less than the distance to neighboring node j from the source node s routed through any other node, i.e., h u +1<h j . If the distance routed through node u is less than that of routed through any other node, then the method proceeds to step 523 . Otherwise, the method proceeds to step 524 .
At step 523 , the following are updated, with the method thereafter proceeding to step 539 : distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to r u ; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 524 , it is checked whether the distance to neighboring node j from the source node s routed through node u is the same as the distance to neighboring node j from the source node s routed through any other node, i.e., h u +1=h j . If the distance routed through node u is the same as that of routed through any other node, then the procedure follows step 525 . Otherwise, the method returns to step 517 .
At step 525 , it is checked whether the number of required converters on the route from the source node s to neighboring node j routed through node u is less than the number of required converters on the route from the source node s to neighboring node j routed through any other node, i.e., r u <r j . If the number of required converters on the route through node u is less than that on the route through any other node, then the method proceeds to step 526 . Otherwise, the method proceeds to step 527 .
At step 526 , the following are updated, with the method thereafter proceeding to step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to r u ; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 527 , it is checked whether the number of required converters on the route from the source node s to neighboring node j routed through node u is the same as the number of converters on the route from the source node s to neighboring node j routed through any other node, i.e., r u =r j . If the number of required converters on the route through node u is the same as that on the route through any other node, then the method proceeds to step 528 . Otherwise, the method returns to step 517 .
At step 528 , it is checked whether the maximum wavelength on the route from the source node s to neighboring node j routed through node u is less than that on the route from the source node s to neighboring node j routed through any other node, i.e., max(t u ,{min(w)|wεW uj })<t j . If the maximum wavelength on the route through node u is less than that on the route through any other node, then the method proceeds to step 529 . Otherwise, the method returns to step 517 .
At step 529 , the following are updated, with the method thereafter proceeding to step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u, the number required wavelength converters r j to r u ; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 530 , if node u is an intermediate node and the requirement of wavelength continuity is not satisfied between wavelengths at input and output ports of node u, then it is checked whether there is a wavelength converter at node u and the wavelength at the input port is convertible to the wavelength at the output port. i.e., a u −M<={min(w)|wεW uj }<=a u +M and C i >0. If there is a wavelength converter at node u and input wavelength is convertible to the output wavelength, then the method proceeds to step 531 . Otherwise, the method returns to step 517 .
At step 531 , it is checked whether the distance to neighboring node j from the source node s routed through node u is less than the distance to neighboring node j from the source node s routed through any other node, i.e., h u +1<h j . If the distance routed through node u is less than that of routed through any other node, then the method proceeds to step 532 . Otherwise, the method proceeds to step 533 .
At step 532 , the following are updated, with the method thereafter proceeding to step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to r u +1; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 533 , it is checked whether the distance to neighboring node j from the source node s routed through node u is the same as the distance to neighboring node j from the source node s routed through any other node, i.e., h u +1=h j . If the distance routed through node u is the same as that of routed through any other node, then the method proceeds to step 534 . Otherwise, the method returns to step 517 .
At step 534 , it is checked whether the number of required converters on the route from the source node s to neighboring node j routed through node u is less than the number of converters on the route from the source node s to neighboring node j routed through any other node, i.e., r u <r j . If the number of required converters on the route through node u is less than that on the route through any other node, then the method proceeds to step 535 . Otherwise, the method proceeds to step 536 .
At step 535 , the following are updated, with the method thereafter proceeding to step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to r u +1; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 536 , it is checked whether the number of required converters on the route from the source node s to neighboring node j routed through node u is the same as the number of converters on the route from the source node s to neighboring node j routed through any other node, i.e., r u =r j . If the number of required converters on the route through node u is the same as that on the route through any other node, then the method proceeds to step 537 . Otherwise, the method returns to step 517 .
At step 537 , it is checked whether the maximum wavelength on the route from the source node s to neighboring node j routed through node u is less than that on the route from the source node s to neighboring node j routed through any other node, i.e., max(t u ,{min(w)|wεW uj })<t j . If the maximum wavelength on the route through node u is less than that on the route through any other node, then the method proceeds to step 538 . Otherwise, the method returns to step 517 .
At step 538 , the following are updated, with the method thereafter proceeding to step 539 : the distance of node j, h j , to h u +1; predecessor node p j to u; the number required wavelength converters r j to r u +1; wavelength at the input port a j to the minimum wavelength slot in the set of available wavelength slots W uj ; maximum wavelength along the route t j to the maximum of t u ; and the minimum wavelength slot into the set of available wavelength slots W uj .
At step 539 , it is checked whether all neighboring nodes are taken into consideration, i.e., jεAdj(u)−Q. If so, then the method proceeds to step 541 . Otherwise, the method proceeds to step 540 .
At step 540 , a neighboring node is selected from the set N−Q which is not yet considered, and the method returns to step 517 .
At step 541 , it is checked whether all nodes in set N−Q are covered. If the set N−Q includes at least one node, then the method proceeds to step 516 . Otherwise, the method proceeds to step 542 .
At step 542 , the destination node is selected, i.e., initialize u=d. At step 543 , the selected node is added in set PATH (i.e., PATH←PATH∪{p u }) and the wavelength at the input port of the selected node a u is added in set WL (i.e., WL←WL∪{a u }). Finally, the predecessor of the selected node p u is chosen (i.e., u=p u ).
At step 544 , it is checked whether the selected node is infinite, i.e, u=∞. If the node is infinite, then the procedure follows the step 545 , otherwise the procedure follows step 543 .
At step 545 , after obtaining the routing and wavelength assignment information in PATH and WL sets, this step checks whether the physical distance traveled by a channel is less than or equal to f(ρ, H sd ), while satisfying the constraints of Equations (1)-(4). If the distance is smaller or equal to f(ρ, H sd ), then the method proceeds to step 547 . Otherwise, the method proceeds to step 546 .
At step 546 , the lowest wavelength slot w among all available wavelength slots W ij , ∀(i, j)εE in the network is removed from all sets of available wavelength slots W ij .
At step 547 , if the distance is smaller than f(ρ, H sd ), then the found routing (PATH) and wavelength assignment (WL) and spectrum allocation
( ⌈ x l i δ ⌉ )
information is returned.
At step 548 , after removing the lowest available wavelength slot w from all sets of wavelength slots W ij , this step checks whether all sets of wavelength slots are empty, i.e., W ij , =ø,∀(i, j). If all sets W ij are empty, then the method proceeds to step 549 . Otherwise, the method proceeds to step 510 .
At step 549 , since no path is available, this step blocks the channel.
It is to be appreciated that the present principles provide many advantages over the prior art. Some of these advantages will now be described. One such advantage is that the tunable routing feature optimizes the network performance over various network load scenarios. Additionally, the proposed procedure reduces the channel blocking probability compared to the RWA-WC procedures in fixed-grid WDM networks. Moreover, the proposed procedure reduces the channel blocking probability compared to the RWSA procedures in FWDM networks. Also, the proposed procedure increases the traffic carrying capacity of networks. Further, the time required in finding the route, operating wavelength and spectrum on each fiber along the route of a channel through the proposed procedure is quick.
Embodiments described herein may be entirely hardware, entirely software or including both hardware and software elements. In a preferred embodiment, the present invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
Embodiments may include a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. A computer-usable or computer readable medium may include any apparatus that stores, communicates, propagates, or transports the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The medium may include a computer-readable medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk, etc.
It is to be appreciated that the use of any of the following “/”, “and/or”, and “at least one of”, for example, in the cases of “A/B”, “A and/or B” and “at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of “A, B, and/or C” and “at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended, as readily apparent by one of ordinary skill in this and related arts, for as many items listed.
Having described preferred embodiments of a system and method (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
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There is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a plurality of optical nodes interconnected by a plurality of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one optical node has at least one wavelength converter for wavelength conversion. The method includes determining a channel route through the network commencing at a source node and ceasing at a destination node. The determined channel route is selectively tunable responsive to selected ones of a plurality of routing methods. The routing methods are so selected responsive to a routing policy having one or more objectives of minimization of channel blocking, minimization of a number of wavelength converters used in the network, and minimization of physical distance traversed by a channel, and minimization of operating wavelengths of a channel.
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FIELD OF THE INVENTION
[0001] The present invention relates to an improvements in the safety and use of a mandolin slicer and more particularly to safety features in a simple mandolin device including a “dead man handle” which works with at least one of a dropping platform or a blade barrier, as well as a child resistant lock to protect, respectively, users and children.
BACKGROUND OF THE INVENTION
[0002] The traditional mandolin slicer which has been commercially available for several decades typically has a sliding board over which is mounted a blade which lies parallel to the sliding board which can produce sliced food by pushing the food to be sliced across the blade. Generally the dimension of the blade above the sliding board determines the thickness of cut. The mandolin board is used to quickly produce a number of slices of even thickness. The user typically controls the food as it is sliced and food stabbing devices are often used to protect the user's hands.
[0003] Another problem with many mandolin slicers is the problem of prevention of movement during use. Many free standing mandolin slicers can move during use because even though they may be free-standing, they don't have structures which enable the users to grasp them securely. When a conventional slicer moves it can slide away, tip over and tumble.
[0004] Further, conventional mandolin slicers have their cutting blades constantly exposed, whether or not the slicer is in use. Any inadvertent contact with the blade, during the time when the slicer is deployed or when being stored and retrieved is a significant danger. Young adults and children who are not aware of the danger of an exposed blade are especially at risk. Many mandolin slicers have a locked position in which the platform is raised to a locking position at the same level as the cutting edge of the blade (or slightly higher). This means that if the slicer is handled there is no chance of the user accidentally slicing their finger or hand. However to resume slicing, the user must unlock the platform so that it can return to a position that allows the blade to slice the food. If the user is using the product and suddenly called away, for example to answer the telephone, the blade remains unguarded. Another person, maybe a child, may touch the slicer and suffer a serious cut as a consequence. This is because locking must be done specially as well as unlocking.
[0005] The utility value of a mandolin slicer depends upon its safety, simplicity and ease of use. For safety, any steps which protect injury during use and after use are very important. Simplicity is important, since a complicated device with many features which occupy a significant volume can complicate cleaning and maintenance. Ease of use is another important factor. The mandolin should be quickly deployable, easy and simple to use, and after use, have a structure which is quickly and easily washable, and quickly stowable to a storage position.
SUMMARY OF THE INVENTION
[0006] A board shaped mandolin slicer includes a folding leg to stably enable the slicer to assume a stable angled orientation. The mandolin slicer includes a front platform having a front end and a rear end, with the rear end of the front platform adjacent and slightly above a front cutting end of a blade. The invention consists of a mandolin slicer with a “dead mans handle”. If the user wants to use the product, a spring loaded handle is squeezed which will automatically expose the blade by either allowing the platform to lower away. If a user were to releases their grip on the handle, the platform or barrier return to their position in front of the cutting edge of the blade thereby returning the product to a safe mode. It is further possible to add a child resistant lock that would stop a young child managing to operate the “dead man's handle” even if the child were strong enough to operate the spring opposed handle.
[0007] So, any time that a user leaves the mandolin slicer and is not clutching a spring loaded handle, the mandolin slicer is in a safety position in which the rear of the front platform covers the front of the blade and insures that any object moving toward the blade is isolated from the blade and is forced to pass over the protected front end of the blade. Also, while in this position the underside of the blade is protected due to a very close and possibly touching relationship of one end of the cam face, and such that it would be nearly impossible to place any object in front of the blade and thus nearly impossible to be cut by the blade even from the underside of the mandolin slicer.
[0008] The use of the mandolin slicer can only be accomplished by placing one hand on the grip actuator. This mechanism insures that the only time the blade is exposed is during use, and that it automatically causes the user to have a very good and stable grip on the overall mandolin slicer to eliminate the possibility that a user could lose control of it.
[0009] In terms of mechanics, a handle includes a spring resist grip actuator which causes a front edge of a front platform to move toward the handle to instantly place the mandolin slicer in a position for use. Aside from providing a slicer where the blade is protected during non-use, the force needed to overcome the spring is strong enough that very small children will be unlikely to be able manipulate the front platform forward to expose the cutting blade. In addition, the spring resist is used in conjunction with a mechanical position guide limiting switch which allows the user to limit the degree to which the front edge of a front platform to move toward the handle to thereby limit the spacing between the rear side of the front platform and the front of the blade, to thus limit the thickness of the slices.
[0010] The user can, by determining the degree to which the spring loaded handle is squeezed, also instantly control the slice thickness. So, without the mechanical position guide limiting switch, the user is free to make slices of varying thickness by controlling the squeeze of the handle. However, most mandolin slicer users want uniform sized slices. The mechanical position guide limiting switch is there so that the user will have a “stop” against which to squeeze, so that the user doesn't have to precisely control a manual grip of the spring loaded handle. In essence the mechanical switch will be enabled to allow the user to squeeze the spring loaded handle to different depths, with the user's only needed control aspect being to simply make physically sure that the handle is squeezed to an extent that it remains securely displace against one of the internal stops controlled by the mechanical position guide limiting switch. In order to allow the user to select the thickness of a slice, it is normal to adjust the height of the platform relative to the blade edge. By linking the height adjustment of the platform to the degree to which the “dead man's handle” is squeezed, it is possible to have the blade edge exposed by varying amounts thereby allowing the thickness of the slice to be adjusted according to the displacement of squeeze. By using adjustable stops, the user can simply move the adjustable stop to the selected position and squeeze the handle fully. The platform will move away from the blade and drop down to the selected position allowing accurate and repeatable slicing.
[0011] Once the mechanical position guide limiting switch is set to a position, actuation of the spring opposed handle will move the front platform forward to a limited position which corresponds to both physical separation of the front platform from the blade and a reduced elevation of the front platform with respect to the blade (due to the action of the cam face at the back end of the front platform acting against the support shaft). The mechanical position guide limiting switch can be configured to perform a locking function by disabling the ability of a user to displace the front platform at all. This position will prevent the blade from becoming uncovered even if the spring urged handle is pulled or squeezed.
[0012] Alternatively, and in addition to the locking function of the mechanical position guide limiting switch, two locking buttons may also be provided through holes in the main housing to lock whenever the front platform is brought to a position to rest over and cover the blade. Thus, it will close two side locks whenever it is left unattended. Two buttons, one on each side of the housing, would provide a child resistant feature as both buttons would need to be urged inwardly at the same time, while the other hand operates the grip, in order to open the mandolin slicer. The two buttons could be depressed to unlock the front platform fairly easily with an adult's hand, whereas a child's hand would have considerable difficulty. Therefore, a child would have to find a way to close both side buttons to unlock, insure that the mechanical position guide limiting switch is unlocked, and then while holding both side buttons, begin to actuate the spring loaded handle to begin to open the space in front of the main blade.
[0013] An adjustable julienne multi blade structure may be provided through the front platform in front of the blade. A series of cutting members supported by a rotatable member is easily deployed in front of the horizontal main blade. The rear side of the front platform is lowered so that the julienne blades assume a height in front of the main horizontal blade which is proportional to the depth of cut to be made by the main horizontal blade. In this configuration, the blades will not exceed the thickness of cut to be made by the main blade. Further, any device which is used to push food and which depends upon the upper rails of the board will not tend to touch the julienne blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:
[0015] FIG. 1 is a perspective drawing of the upper surface of the mandolin slicer to facilitate a brief introduction of the names and orientation of the main components of the slicer, and shown with the folding leg in stowed position;
[0016] FIG. 2 is a side view roughly corresponding to the overall view seen in FIG. 1 shown to emphasize the exterior simplicity, and portability, stowability and ease of use;
[0017] FIG. 3 is an exploded view of the mandolin slicer seen in FIGS. 1-2 and in which the components are further identified and the details and relationship of assembly is more completely seen;
[0018] FIG. 4 is a front perspective view of the spring loaded handle with the mechanical position guide limiting block exploded away from to reveal details as a double series of cross shaped projections or stops from a back wall of the handle;
[0019] FIG. 5 is a perspective upward view of the underside of the mandolin slicer illustrating button locks which can be employed, in addition to the “dead man's handle” to even further child-proof the mandolin slicer;
[0020] FIG. 6 is a perspective view of the underside of the mandolin slicer illustrating an overall view of the components and detail of structures;
[0021] FIG. 7 a perspective view of the mandolin slicer seen in a deployed position ready for use with the leg assembly deployed and supporting the handle end of the slicer;
[0022] FIG. 8 is a perspective view from above of one possible embodiment of a food engaging pusher which may be used with the mandolin slicer of FIGS. 1-7 ;
[0023] FIG. 9 is an exploded view of the food engaging pusher of FIG. 8 which illustrates a separate plug portion having a series of food engaging extensions and a base having a regularly triangularly jagged downwardly directed member;
[0024] FIG. 10 illustrates a bottom plan view of the food engaging pusher of FIGS. 8-9 ;
[0025] FIG. 11 is a closeup view of the end of the front platform showing an exaggerated view of blade guard which exceeds the height of the front platform;
[0026] FIG. 12 illustrates a closeup view of the end of the front platform showing an exaggerated view of a “Y” shaped blade guard which has portions which will cover the exposed blade both above and below the edge of the blade; and
[0027] FIG. 13 illustrates a reversal of the location of the cam face seen as a structure supported by the side rails, with a cam follower provided as part of the front platform;
[0028] FIG. 14 illustrates an embodiment in which the front end of the front platform is pinned to the side rails and in which the handle operates a blade guard directly to pull the blade guard underneath the front platform to give the advantage of stability and the ability to have the blade guard move relative to the front platform; and
[0029] FIG. 15 illustrates an arrangement similar to that seen in FIG. 14 , but where a cam member having a surface which cooperates with a support shaft which is moved farther toward its pivot point and where a platform is seen having a flattened end which has an arc of swing which brings it close to the front edge of the blade.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] The description and operation of the mandolin slicer of the invention is best begun with reference to FIG. 1 which illustrates a perspective drawing of the upper surface of a mandolin slicer 21 to facilitate a brief introduction of the names and orientation of the main components. Mandolin slicer 21 has a pair of side rails, including a left side rail 23 and a right side rail 25 . The side rails 23 and 25 may be joined by an end handle 27 . Side rails 23 and 25 and end handle 27 may be formed simultaneously.
[0031] The end handle 27 may have a mechanical switch 31 to set the cutting height between a front platform 33 and a cutting blade 35 . In the view of FIG. 1 , the front platform 33 slightly overlies the front edge (not seen in FIG. 1 ) of handle upper portion of the slicer, and is shown with the folding leg in stowed position. Considering the end handle 27 to be the front end of the mandolin slicer 21 , to the rear of the cutting blade 35 is a rear platform 37 which is seen to have a curved portion 41 .
[0032] The end handle 27 has a number of symbols 43 printed above the mechanical switch 31 which include a picture of a pad lock, adjacent a number of columns having one rectangular symbol, two rectangular symbols and three rectangular symbols. These symbols correspond to and show that the mechanical setting of the mechanical switch 31 can be set to allow the front platform 33 and a cutting blade 35 to be set to a locked position as shown, or can assume a position where front platform 33 is gradually separated away from cutting blade 35 in graduated degrees in order to produce a graduated cutting slot just in front of the cutting blade 35 , as will be shown in greater detail in subsequent drawings.
[0033] A spring loaded handle 47 includes a grip portion 51 and a guide rail portion 53 , of which only a left guide rail portion 53 is observable in FIG. 1 . When gripped and when force is applied to cause the grip portion 51 to move toward the end handle 27 , the portion of the spring loaded handle 47 seen will move into the end handle 27 , and the front platform 33 will move toward the end handle 27 . Before or after this compressive movement has occurred, and to limit the distance the grip portion 51 can be drawn into end handle 27 to limit the movement of the front platform 33 away from the blade 35 the mechanical switch 31 can be moved to a limit position. By limiting the movement of the front platform 33 away from the blade 35 the user can have a controlled, consistent limitation on the cutting thickness without having to keep the user's hand under exactly displacement control.
[0034] Also seen on the right side of the mandolin slicer 21 is a julienne control knob 55 , having a covering end cap 56 . Julienne control knob 55 controls a series of blades (not shown in FIG. 1 ) which can be raised through a series of julienne blade slots 57 which are formed into front platform 33 . A separation is seen between the julienne blade slots 57 and the blade 35 of about the same distance as the length of the julienne blade slots 57 . Turning the julienne control knob 55 will deploy the blades (not seen), each one in its associated julienne blade slot 57 .
[0035] Other details seen include a curving portion 61 of the front platform 33 , and an upper handle guide rail 65 in which slidably supports guide rail portion 53 of spring loaded handle 47 from the upper side. Curving portion 61 of the front platform 33 is adjacent an opening 63 between curving portion 61 and the grip portion 51 . Mechanical switch 31 is seen operating as a side to side slide switch within a depression 67 to provide stable, protected, controlled movement for the mechanical switch 31 . A leg and notch fixture 75 is also partially seen at the underside of the right side rail 25 at the end opposite end handle 27 .
[0036] Referring to FIG. 2 , a side view roughly corresponding to the overall view seen in FIG. 1 shown to emphasize the exterior simplicity, and portability, stowability and ease of use of the mandolin slicer 21 . Leg and notch fixture 75 is seen to have a notch 77 for resting the mandolin slicer 21 on the edge of a bowl or pan. Leg and notch fixture 75 may be made of a soft, non-skid material to stabilize the mandolin slicer 21 whether supported by a flat surface or pan or bowl. The underside of right side rail 25 (and left side rail 23 although not seen in FIG. 2 ) is seen as having a less recessed, downwardly projecting outer wall 81 and a more recessed, downwardly projecting inner wall 83 . The space between the outer wall 81 and inner wall 83 form a channel 85 . The channel 85 is utilized to partially accommodate a fold down leg angled member 87 . As can be partially seen, is a fold down leg angled member 87 which is attached to a bar portion 91 which may be covered in a soft elastomeric member 93 for non-skid support when the mandolin slicer 21 is supported by its own folding leg assembly (not yet completely seen).
[0037] Near the bottom of FIG. 2 , on the end of the mandolin slicer 21 nearest the mechanical button 31 , a leg bushing 95 is seen inboard of outer wall 81 and outboard of inner wall 83 . The leg bushing 95 engages the leg and assists its pivot action. A leg bushing securing member 97 has walls to match outer wall 81 and inner wall 83 , including an inner wall 103 and an outer wall 105 . A slanted joining line 107 is seen between the inner walls 103 and 83 , while a very abbreviated slanted joining line 109 is seen between the outer walls 81 and 105 . To the right of julienne control knob 55 is a julienne blade guard 113 which guards against inadvertent manual contact with the julienne blades (not yet seen), especially in their stowed position.
[0038] Referring to FIG. 3 , an exploded view of the mandolin slicer 21 is see to better illustrate all of the components of the mandolin slicer 21 and their relationship with each other. At the upper left, the rear platform 37 is shown as having a recessed space 121 for accommodating the blade 35 so that in general the planar top of blade 35 will be generally even with the top surface of rear platform 37 . A series of mounting apertures 123 or other structures. Partially seen at the underside of the rear platform 37 is a series of protrusions or locating pegs 125 are preferably ultrasonically welded to left and right side rails 23 and 25 to help further stabilize the rear platform 37 . The underside of the recessed space 121 has an angled surface 127 to provide a more gentle exit for food sliced by blade 35 and to facilitate an unmolested orderly exit for the sliced portion of such food.
[0039] Shown to the right of the angled surface 127 , the blade 35 is seen. Blade 35 has a sharpened front edge 131 . Blade 35 may have structures on its underside or opposite side to that shown in FIG. 3 with will interfit with the mounting bores or apertures 123 . In FIG. 3 , just below the blade 35 , a support shaft 135 is seen. Support shaft 135 connects between the left side rail 23 and right side rail 25 and forms a support for the camming action of the rear of the front platform 33 . The support shaft 135 has a pair of reduced diameter portions 137 at each end, only one of which is clearly seen in FIG. 3 , so that it can engage an aperture and be limited in its insertion into that aperture.
[0040] Below the support shaft 135 , a julienne assembly 141 is seen. In addition to the control knob 55 and covering end cap 56 , a friction spring 145 is seen. To the left of friction spring 145 a julienne blade support barrel 147 supports a series of evenly spaced julienne blades 149 . The julienne blade slots 57 should be able to accommodate the julienne blades 149 over the range of translation and elevation changes which the front platform 33 is capable. The spacing of the julienne blades 149 are spaced to correspond to the spacing of the julienne blade slots 57 of the front platform 33 . The orientation of the julienne blades 149 are the same as they would appear through the julienne blades slots 57 , with the rear of the blades having a flat edge 151 which would be supported by the end of the julienne blades slots 57 nearest the main blade 35 as seen in FIG. 1 . Julienne blade support barrel 147 has a pair of projections 153 , only one of which is seen an partially obscured by spring 145 . The friction spring 145 will surround the projection 153 on one side and is used so that some frictional stability is added to the supported julienne blade support barrel 147 so that when the julienne blades 149 are raised they will not inadvertently tip down and so that when the julienne blades 149 are in the down position, they will not be inadvertently raised. Further, projection 153 is surrounded by a series of detent projections 154 which may be on one side only of the julienne blade support barrel 147 and interact with matching structure on the inside of right side rail 25 (not shown) so that the julienne blade support barrel 147 may be selectably set at a number of stable positions. This is but one of many ways that the julienne blade support barrel 147 may be pivotally fixed in a stable position.
[0041] Seen below the julienne assembly 141 is the julienne blade guard 113 . Julienne blade guard 113 has a three sided structure including a base 155 , longer front wall 157 and shorter rear wall 159 . A pair of side walls 116 cover the sides of the portion of the julienne blade guard 113 which extend slightly below the more recessed, downwardly projecting inner wall 83 on each of the left and right side rails 23 and 25 .
[0042] Near the upper corners of the longer front wall 157 and the shorter rear wall 159 , a lateral projection 161 is seen, but only on the lateral side facing the viewer. The projections 161 on the opposite sides are not clearly seen and are indicated by arrows.
[0043] To the left of the julienne blade guard 113 , the front platform 33 is again seen. Some details of the underside are seen including a front cam face 165 which is positioned to engage the support shaft 135 . As front cam face 165 engages the support shaft 135 , the support shaft 135 supports the rearward side of the front platform 33 . When the front platform 33 is moved slightly forward, toward the end handle 27 , the rear end of the front platform 33 most closely adjacent the blade 35 is allowed to both move forward and downward by the action of the front cam face 165 . Movement of the front platform 33 toward the blade 35 causes the rear end of the front platform 33 to move upward as it approaches the blade 35 , and preferably to a point that it meets but is slightly above the sharpened front edge 131 of the blade 35 . This action of meeting at a point slightly above the front edge 131 of the blade 35 helps insure protection of the sharpened front edge 131 of the blade 35 as well as to protect users from inadvertent contact with sharpened front edge 131 of the blade 35 .
[0044] Front cam face 165 may be planar to give a completely proportional action against the support shaft 135 , but it can also be curved to produce a non-linear approach/displacement profile, such as an exponential drop away at the start of the displacement of the front platform 33 . This causes the ability to make thicker slices to occur immediately upon opening of the mandolin slicer 21 , but gives a finer adjustment range concentrating on the thicker slices. Conversely, it may cause the rear end of the front platform to drop slowly during the first portion of its travel and drop more steeply at the latter portion of its travel, to give a finer adjustment range concentrating on the thinner slices.
[0045] Further, the action of moving the platform 33 away from the blade 35 adjusts the height at which the sharpened front edge 131 of the blade 35 will engage a moving food mass. When the front platform 33 is in a forward position, the rear end of the front platform 33 will have moved down to enable the front edge 131 of the blade 35 to cut a moving food mass at a greater height above the front platform 33 to produce a thicker slice to be ejected during cutting below the angled surface 127 . Conversely, when the front platform 33 is in a rearward position, the rear end of the front platform 33 will have moved upward to enable the front edge 131 of the blade 35 to cut a moving food mass at a lesser height above the front platform 33 to produce a thinner slice to be ejected during cutting below the angled surface 127 and underneath the mandolin slicer 21 .
[0046] Front platform 33 , underneath and adjacent curving portion 61 , has a curved fitting 171 having a downwardly directed engagement opening 173 . Curved fitting 171 and downwardly directed engagement opening are used to enable the grip portion 51 of the spring loaded handle 47 to exert forward motion, toward the end handle 27 , upon the front platform 33 .
[0047] As can be seen, the end handle 27 and the side rails 23 and 25 may be formed as a one piece unit. With the exception of an upward extension of the more recessed, downwardly projecting inner wall 83 to form an accommodation space 181 , both of the insides of the side rails 23 and 25 are nearly identical. In the view of FIG. 3 , many of the inside details of side rail 25 are identical to those of side rail 23 and those features of side rail 23 may be may be visible.
[0048] Side rails 23 and 25 each have a rear platform support rail 185 which may have a series of small blind bores 187 to interfit with the series of protrusions 125 of the rear platform 37 . The rear platform support rails 185 support the rear platform 37 and insure that it will remain locked into place between side rails 23 and 25 and is preferably affixed by ultrasonic welding.
[0049] Forward of the a rear platform support rail 185 each of the side rails 23 and 25 have a shallow support shaft blind bore 191 into which will fit the reduced diameter portions 137 at each end of the support shaft 135 .
[0050] Also seen is an inwardly disposed rim 193 which may be used as a limited overhang and against which the front platform 33 may be limited in its upward pivoting movement, and which may also serve to support and stabilize blade 35 and rear platform 37 . Adjacent the shallow support shaft blind bore 191 , each of the side rails 23 and 25 has a julienne blade support barrel bore 195 which will rotationally support projections 153 of the julienne blade support barrel 147 to pivot between a deployed and stowed position. Accommodation space 181 is adjacent julienne blade support barrel bore 195 . Accommodation space 181 enables a closer connection of julienne control knob 55 to one of the pair of projections 153 .
[0051] A pair of small blind bores 197 and 199 on each of the side rails 23 and 25 correspond to the lateral projections 161 on the julienne blade guard 113 . The longer front wall 157 is supported between the small blind bores 197 and the shorter rear wall 159 is supported between the small blind bores 199 .
[0052] A small slot 207 interrupts the more recessed, downwardly projecting inner wall 83 at a place where the bar portion 91 of the leg assembly (to be discussed) folds under the side rails 23 and 25 . Closer to the end handle 27 and under the level of the upper handle guide rail 65 , a lower handle guide rail 211 is present on both the side rails 23 and 25 . Between the upper handle guide rail 65 and lower handle guide rail 211 , the guide rail portion 53 of the spring loaded handle 47 is supported, guided and allowed to translate between the forward and rear positions smoothly.
[0053] A number of components are seen adjacent the end handle 27 . A lower housing 221 , during assembly, makes way for entry of the spring loaded handle 47 , with its guide rail portions 53 slidably entered into the space between the upper handle guide rail 65 and lower handle guide rail 211 . Lower housing 221 includes spring securing posts 225 which will engage springs 227 . The other end of springs 227 engage spring engaging posts 231 at the front of the spring loaded handle 47 . Thus, when the lower housing 221 is assembled in place, the spring loaded handle 47 is urged toward the blade 35 and away from the end handle 27 .
[0054] On the end handle 27 , the depression 67 is adjacent an access opening 235 . The mechanical switch 31 is seen as having a lever 237 which will extend into the access opening 235 . A clip 239 is slidably attached to the lever 237 after it is extended through the access opening 235 to hold it in place. A mechanical position guide limiting block 243 is engaged by the lever 237 and used to control the permitted position of the spring loaded handle 47 in the direction towards the end handle 27 .
[0055] To the right of the right side rail 25 , a full view of a leg assembly 251 is shown. In addition to the fold down leg angled member 87 , bar portion 91 , and soft elastomeric member 93 , the angled member 87 is seen to be connected to a fold down leg curved member 253 . The curved member 253 and straight member 71 join to form a single member and curve inward to a pair of terminations 255 . These facing terminations 255 are inserted into the leg bushings 96 . The placement of the Lower housing 221 causes the covering outer wall 105 to trap end terminations 255 within the leg bushings 96 .
[0056] The leg and notch fixture 75 are each seen as having a plug insert portion 261 each of which are affixed into the far ends of the left and right side rails 23 and 25 . On the inside of the guide rail portion 53 , inward projections 265 are seen. The projections 265 will be engaged by the engagement opening 173 of the curved fitting 171 . The engagement opening 173 may have a snap fit onto the projections 265 .
[0057] Referring to FIG. 4 , a front perspective view of the spring loaded handle 47 with mechanical position guide limiting block 243 exploded away from it sufficient to see its details, reveals a number of structures. Aside from the two spring engaging posts 231 already seen, a series of cross shaped projections from a back wall 271 are horizontally joined by a common central horizontal projection 275 . The central horizontal projection 275 is shared by the two spring engaging posts 231 , and a number of projection areas from the back wall 271 . The projections seen occur in pairs and include a first locking projection 281 and a second locking projection 283 . The first and second locking projections 281 and 283 project farthest from the back wall 271 (disregarding the two spring engaging posts 231 ) and when mechanical position guide limiting block 243 is positioned in front of first and second locking projections 281 and 283 , the spring loaded handle 47 cannot be compressed into the lower handle guide rail 211 , and the front platform 33 cannot be urged away from the blade 35 .
[0058] A first thinnest slice support projection 287 and a second thinnest slice support projection 289 are located adjacent the first and second locking projections 281 and 283 and have a displacement away from the back wall 271 of a lesser distance than the first and second locking projections 281 and 283 . First and second thinnest slice support projections 287 and 289 enable spring loaded handle 47 to be slightly compressed into the lower handle guide rail 211 , so that the front platform 33 is urged down and away from the blade 35 sufficient to produce the thinnest slices.
[0059] Adjacent first and second thinnest slice support projections 287 and 289 , First and second medium slice support projections 291 and 293 enable spring loaded handle 47 to be compressed into the lower handle guide rail 211 about half of the maximum distance, so that the front platform 33 is urged down and away from the blade 35 sufficient to produce the medium thickness slices. Adjacent first and second medium slice support projections 291 and 293 , first and second thickest slice support projections 297 and 299 enable spring loaded handle 47 to be compressed into the lower handle guide rail 211 to the maximum distance, so that the front platform 33 is urged down and away from the blade 35 sufficient to produce the maximum thickness slices.
[0060] The mechanical position guide limiting block 243 has a main plate 307 with a rectangular aperture 309 through which the lever 237 extends, in order to connect the mechanical position guide limiting block 243 to the mechanical switch 31 and enable the mechanical position guide limiting block 243 to move laterally with any lateral movement of the mechanical switch 31 . Attached to the main plate 307 are a pair of spaced apart parallel engagement plates 311 and 313 . The spacing of the spaced apart parallel engagement plates 311 and 313 is the same spacing between projections 281 and 283 , projections 287 and 289 , projections 291 and 293 , and projections 297 and 299 . These force bearing pairs help spread and stabilize the force resistance of the grip portion 51 against the mechanical position guide limiting switch 243 , which is in turn supported, through its main plate 307 as main plate 307 bears against the inside of the lower housing 221 . Other possibilities include greater multiples of the spaced apart parallel engagement plates 311 and 313 , and corresponding multiples of the projections 281 , 287 , 291 , and 297 . A sloping, and therefore continuous surface would allow selection of an infinite number of thicknesses to be selected.
[0061] Referring to FIG. 5 , a perspective upward view of the underside of the mandolin slicer 21 nearest the end handle 27 illustrates one possible embodiment of the previously mentioned button locks. A button aperture 325 permits partial passage of a spring loaded button 327 . As can be seen from the opposite side, the button 327 can be made of a cantilevered part of the material making up the guide rail portion 53 of the spring loaded handle 47 . A keyhole cut about the cantilevered portion and its location in the guide rail portion 53 of the spring loaded handle 47 permits this feature to be added simply with a button aperture 325 and a substituted spring loaded handle 47 .
[0062] FIG. 6 is a perspective view of the underside of the mandolin slicer 21 which illustrates a good overall view of the components and detail of structures best seen from a bottom view. A series of three rivets 351 are seen adjacent the angled surfaces 127 for holding the blade 35 in place. The notches 77 of each of the leg and notch fixtures 75 are seen as having a parallel orientation and are wide enough to accommodate either a linear or curved member placed between them.
[0063] Referring to FIG. 7 , a perspective view of the mandolin slicer 21 is seen in a deployed position ready for use. There is plenty of clearance for a user to set the mechanical switch 31 , and bring the user's hand around the end handle 27 through the leg assembly 251 . The user will likely bring their fingers around the grip portion 51 in order to urge it toward the end handle 27 to cause the front platform 33 to move away and down from the blade 35 . While still grasping the end handle 27 and grip portion 51 together simultaneously the user can slice foods by sliding them along the front platform 33 and toward the main blade 35 . The julienne blades 149 are also illustrated in the deployed position.
[0064] Referring to FIG. 8 , one possible embodiment of a food engaging pusher 375 is shown. The use of a food engaging pusher 375 is important for protecting the user's hand from any contact with either the main blade 35 or the julienne blades 149 , especially when the mass of food being cut has a small remaining mass. The food engaging pusher 375 has a knob portion 377 , upper cap 379 and an upwardly curved lower portion 381 . The upwardly curve lower portion 381 may have a regular shape and thus may have some indicators such as arrows 385 to indicate the orientation for the user to use with the mandolin slicer 21 .
[0065] Referring to FIG. 9 , an exploded view of the food engaging pusher 375 shows that the cap 379 is part of a plug 391 having a series of food engaging extensions 393 . The upwardly curved lower portion 381 has a bore 395 , with the lower opening of the bore 395 having a regularly triangularly jagged downwardly directed member 397 . A curved space 399 lies under the arrows 385 seen in FIG. 8 . Referring to FIG. 10 , a bottom view of the food engaging pusher 375 illustrates the overall shape and illustrates the structures which will engage a mass of food working together.
[0066] Referring to FIG. 11 , a closeup schematic side view of the end of the front platform shows an exaggerated view of a blade guard 425 which exceeds the height of the front platform 33 . Here the end of blade guard 425 extends slightly above the surface of the front platform 33 . The ramp effect will not significantly impact the slicing function, and the top of the blade guard 425 may simply include a slight upturn of the end of the front platform 33 to form the over coverage of the edge 131 of the blade 35 . The blade guard 425 is shown as somewhat continuous with the angled surface 127 but it can be discontinuous with the angled surface 127 .
[0067] Referring to FIG. 12 a closeup view of the end of the front platform showing an exaggerated view of a “Y” shaped blade guard 431 is seen. The “Y” shaped blade guard 431 is shown somewhat exaggeratedly, but provides an upper edge 433 which will rest over the edge 131 of blade 35 and a lower edge 435 which will rest under edge 131 of blade 35 .
[0068] Referring to FIG. 13 , a reversal of the location of the cam face 127 is seen where a cam follower member 341 is provided to work in conjunction with a cam member 345 which may depend from the left side rail 23 . The cam member 345 may be formed integral with the left side rail 23 (not shown in FIG. 13 ) and it may only need to extend a centimeter or so beyond the inside surface of the left side rail 23 and thus can be inexpensively formed and made. The front platform 33 may still guard the front edge 131 of the blade 35 depending upon the manner in which the cam member 345 is set.
[0069] Referring to FIG. 14 , an embodiment in which a front end of a front platform 352 may have a pivot pin 353 or other pivot connection to the left and right side rails 23 and 25 . A guard link 357 is connected to a combination blade guard and cam member 361 , and to the curved fitting 171 . The guard link 357 moves underneath the front platform 33 and in essence moves behind the edge of the front platform 352 which may then be positioned quite close to the front edge of the front edge of the blade 131 .
[0070] Referring to FIG. 15 an arrangement similar to that seen in FIG. 14 is illustrated, but where a cam member 127 is seen as having a surface which cooperates with a support shaft 135 which is moved farther toward its pivot point 353 . A front platform 381 has a vertically broader end 385 which has the capability to provide a guarding extent both above and below the blade 35 . FIG. 15 also illustrates that a range of placement for the cooperating cam members can occur along a broad length, from adjacent and under the blade 35 to a point much farther away from the blade 35 . This also opens the possibility for a shorter displacement stroke for grip portion 51 which may translate into a mechanically advantaged lowering of the front platform 381 . The flattened end 385 of the platform 381 has an arc of swing which comes close enough to the front edge 351 of the blade 35 to effectively isolate it from manual contact, but so close enough that any part of the flattened end 385 will touch front edge 351 of the blade 35 .
[0071] While the present invention has been described in terms of a structure, device and process for a new mandolin slicer and which has high safety and ease of use characteristics; one skilled in the art will realize that the structure and techniques of the present invention can be applied to many structures and devices which are used in the kitchen, and particularly where ease of use, safety, and adjustability can be achieved in a single device.
[0072] Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.
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A board shaped mandolin slicer includes a folding leg for stability in an angled orientation, and a “dead mans handle” for to enable exposure of the blade and adjustable thickness slicing only upon actuation of the handle. In addition, a spring resist in the handle is used in conjunction with a mechanical position guide limiting switch and angled cam which allows the user to better control the degree to which a platform move forward to expose the front of a main blade, to thus adjust the thickness of the slices uniformly. An additional child safety feature includes a pair of buttons on either side of the housing which need to be urged inwardly at the same time to unlock the mandolin slicer.
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BACKGROUND OF THE INVENTION
The system design aspect of recent years has driven the requirements for special tools and practices to ensure high speed signaling quality, especially for backplanes and connector via arrays.
The speeds of signals used in the industry increases at about an average rate of twice every two years. As a result the rise time of signals used on backplanes and other printed circuit boards (PCBs) decreases and the bandwidth required to deliver those signals from point to point increases (doubles every two years). Transport data rates of 3.125 Gigabits per second (Gbps) are now commonplace in board-to-board applications. As data rates increase to 5, 6.25, or 10 Gbps each part of the channel must be examined to increase performance.
A channel includes plated through holes (PTHs), also called vias, that transport signals into interior layers of a multi-layer PCB as depicted in FIG. 1 . PTHs are common to many device packages such a Ball Grid Arrays (BGAs) and other connector types. Typically, in a backplane system a signal path between a transmitter and receiver includes several vias or PTHs.
PTHs are fabricated by drilling a hole through a multi-layer PCB. As is known in the art, a multi-layer PCB includes conductive traces separated by dielectric layers. The hole is plated with a conductor, such as copper, and a pad is formed to connect the PTH to a particular one of the conductive traces. As depicted in FIG. 1 , a PTH 10 may be utilized to conduct a signal from a capture pad 12 mounted on the surface 14 of the PCB to an internal trace 16 . In this case, the PTH has a pad on the surface for connecting with the capture pad and another pad connected to the selected internal trace. The PTH is insulated from all other traces.
At high frequencies the PTH joining a surface pad to an interior trace will affect signal shaping. Depending on the frequency of the signal and the dimensions of the PTH, signal energy may be reflected from the PTH or converted into radiation thus causing loss of signal power and other undesirable side effects.
It is known that the frequencies where the PTH acts as a filter are determined by the unused portion of the hole, referred to as the resonant stub. In FIG. 1 , the portion of the PTH that extends beyond the selected trace layer is the resonant stub 18 . One technique for controlling the effects of the stub is to alter its size by a technique known as “back-drilling”, where plating is removed from the unused portion of the PTH by drilling from the back side of the PCB as depicted in FIG. 2 . Back-drilling necessarily entails a tradeoff between manufacturing costs and electrical performance. Its effectiveness is limited by drilling depth accuracy and the increased cost of multi-depth drilling.
However, these simple back-drilling techniques (used to reduce the stub effect) in some cases are not adequate to guarantee high quality signaling at the speed of 2 Gbps and above.
Other known techniques exist that utilize more exotic technology, such as embedded passive or active filters in the PCB, to reduce reflections and shape signals. However, those techniques are expensive and, in most cases, not useful in mass production of PCBs.
The challenges in the field of high-frequency transmission continue to increase with demands for more and better techniques having greater simplicity and lower cost. Therefore, a need has arisen for a new system and method for controlling reflection and signal shaping caused by PTHs.
BRIEF SUMMARY OF THE INVENTION
In one embodiment of the invention, standard back-drilling technology is utilized to remove resonant stubs of ground PTHs in the vicinity of a back-drilled signal PTH to shape a signal and reduce reflections.
In another embodiment of the invention, the stub lengths of ground PTHs are varied to control signal shaping at selected signal frequencies.
Other features and advantages of the invention will be apparent in view of the following detailed description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective, cut-away view of a plated through hole;
FIG. 2 comprises cross-sectional views depicting the back-drilling process;
FIG. 3 is top view of a layout of signal and ground PTHs;
FIG. 4 is a side view of the layout of FIG. 3 ;
FIG. 5 is a perspective, cut-away view of an embodiment of the invention;
FIG. 6 is a graph illustrating the operation of an embodiment of the invention; and
FIG. 7 is a flow chart depicting steps performed by an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to various embodiments of the invention. Examples of these embodiments are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that it is not intended to limit the invention to any embodiment. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. However, the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
FIGS. 3 and 4 depict a layout of PTHs on a printed circuit board. As is known in the art, signal PTHs are usually placed between ground PTHs to reduce cross-talk between signals. In FIG. 3 , signal PTH 30 is placed between first, second, third, and fourth ground PTHs 32 ( 1 )- 32 ( 4 ). FIG. 4 is a side views depicting a signal PTH 30 that has been back-drilled to reduce the size of the resonant stub and that is surrounded by the four ground PTHs 32 ( 1 )- 32 ( 4 ).
The inventors have discovered that the signal quality of a channel and the ability to transfer high frequency signals through a variety of board thicknesses can be improved by applying standard back-drilling techniques to reduce the resonant stub length of the ground PTHs surrounding a signal PTH.
FIG. 5 depicts a preferred embodiment of the invention where ground PTHs 32 ( 1 )- 32 ( 4 ) have been back-drilled so the resonant stubs of the ground PTHs have been reduced in size.
FIG. 6 is a graph depicting the attenuation of a signal at various frequencies. The dotted line depicts a significant increase in signal attenuation at 15 Ghz. As depicted by the dashed line, this signal attenuation is much less pronounced after the ground PTHs have been back-drilled. The effect of the ground PTH back-drilling as shown in the graph makes the channel much more “flat”, i.e. there is much less resonance and reflection on the channel. This has a direct effect on the signal quality at the output of that channel/via structure.
In the embodiment described above standard back-drilling techniques are utilized. The signal and ground PTHs can be back-drilled during the same fabrication without adding significant cost or complexity to manufacturing a PCB.
In a preferred embodiment, the ground PTHs in a backplane are back-drilled, however the technique is useful in any board used to form high-frequency signal transmission channels.
In another embodiment of the invention, the lengths of the resonant stubs of the signal and ground PTHs can be varied to shape the transmitted signal according to the requirements of the channel.
In this embodiment of the invention, signal PTH back-drilling combined with the GND PTH back-drilling creates a filter effect on the signal. As depicted in the flow chart of FIG. 7 , the filtering formula is changed by adjusting the depth of the back-drilling of the signal PTH and back-drilling the ground PTHs to the same or different depths.
Using modeling tools (like HFSS manufactured by Ansoft) the transformation formula of the channel is extracted for every back-drilling depth and the required signal filtering or shaping can be set. Thus, the output signal can be controlled, filtered and shaped according to the transformation formula of the PTH structure and can be adjusted by changing the back-drilling depths.
The invention has now been described with reference to the preferred embodiments. Alternatives and substitutions will now be apparent to persons of skill in the art. For example, the diagrams depict a signal PTH surrounded by four ground PTHs, however, the invention is not limited to any number or configuration of PTHs. Further, modeling programs other than HFSS can be utilized as is understood by persons of skill in the art. Accordingly, it is not intended to limit the invention except as provided by the appended claims.
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A method and apparatus for shaping signals transmitted via plated through holes (PTHs) utilizes standard back-drilling techniques to reduce the resonant stub lengths of ground PTHs in the vicinity of a back-drilled signal PTH.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of co-pending U.S. Provisional Patent Application No. 61/659,988, filed on Jun. 15, 2012, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a flexible-rigid circuit board composite and a method for producing a flexible-rigid circuit board composite according to the preambles of the independent claim(s).
BACKGROUND
[0003] A flexible-rigid circuit board composite represents a hybrid composite of circuit boards, also referred to as PCB (printed circuit board), in which flexible and rigid circuit boards are connected to one another to form a single circuit board composite. The various layers of a multilayer flexible-rigid circuit board composite are typically connected via metallically coated through openings.
[0004] U.S. Publication No. 2004/0118595 discloses a circuit board composite made of flexible and rigid circuit boards, in which at least one flexible circuit board is arranged on at least one rigid circuit board. For this purpose, the rigid circuit board intentionally has a structural weak point at a defined position. The structural weak point is used for the purpose of intentionally breaking off the rigid circuit board and connecting the fracture edges to the flexible circuit board.
[0005] A method for producing a rigid-flexible printed circuit board composite (PCB) from rigid and flexible circuit boards is disclosed in U.S. Pat. No. 7,690,104. The circuit boards are placed on a carrier, on which the circuit boards are aligned to one another so that the bond regions of the flexible circuit board overlap with the bond regions of the rigid circuit board. The aligned circuit boards are subsequently pressed together and sent through a reflow furnace, with the solder on the circuit boards melting and, after the solidification, the circuit boards and electrical components located thereon being mechanically and electrically connected.
[0006] The fastening of flexible connecting bridges to rigid or stiffened PCBs is typically performed to utilize the advantages of packaging, i.e., construction and connection technology, with flexible substrates in costly electronic components, in which significantly more cost-effective rigid circuit boards are used for reasons of cost. Such a connection step, typically by means of hot bar soldering or laser soldering, is performed in discrete steps, circuit by circuit.
[0007] The additional handling and positioning of isolated flexible connecting bridges and PCB structures is difficult to automate, which results in high production costs and decreases the cycle time for the production of the flexible connections. In small PCB structures, as are used in medical implants, these problems are increased still further.
[0008] The present invention is directed toward overcoming one or more of the above-identified problems.
[0009] The present invention is based on an object of providing a flexible circuit board which allows extensive automation of the production method of a flexible-rigid circuit board composite.
[0010] A further object is the provision of a flexible circuit board arrangement having at least one flexible circuit board for a flexible-rigid circuit board composite, which allows extensive automation of the production method of a flexible-rigid circuit board composite.
[0011] Yea a further object is to provide a flexible-rigid circuit board composite which is producible cost-effectively with high precision and is suitable, in particular, for electronics in medical implants.
[0012] Still a further object comprises providing an improved method for producing a flexible-rigid circuit board composite.
SUMMARY
[0013] An object(s) is achieved according to the present invention by the features of the independent claim(s). Advantageous exemplary embodiments and advantages of the present invention result from the further claims, the drawings, and the description.
[0014] According to a first aspect, the present invention is directed to a flexible circuit board for producing a flexible-rigid circuit board composite made of at least one flexible circuit board and at least one rigid circuit board, the at least one flexible circuit board having at least one first planar segment, which interacts as intended with at least one second planar segment of the at least one rigid circuit board in the installed state.
[0015] It is proposed that the at least one planar segment comprise at least one flexible connecting element, which is elastically connected to a face of the at least one first planar segment.
[0016] Through the elastic connection, the flexible connecting element can be movable, in particular, parallel to the surface of the first planar segment, in particular within the first planar segment. If the first planar segment extends, e.g., in the x-y plane, the flexible connecting element can advantageously be movable in the x-direction and in the y-direction before a fixed connection to the rigid circuit board. It is advantageously possible through the elastic connection of the flexible connecting element to align it for contacting with high precision. The flexible connecting element can be coarsely pre-aligned for this purpose, if the flexible circuit board having the at least one first planar segment is moved toward its connection partner, the rigid circuit board, during installation as intended. This can be performed particularly advantageously if multiple first and second planar segments are provided in a matrix-type arrangement, which can be aligned in parallel in one method step.
[0017] The flexible connecting element can have one or more electrical components, for example, electrical feedthroughs, components such as surface-mountable SMD components (SMD=surface-mounted device), electrical circuits, and the like.
[0018] According to an advantageous embodiment, the at least one flexible connecting element can be embedded within the face of the at least one first planar segment. This allows simple production of the flexible connecting element using typical means in the production of circuit boards.
[0019] According to an advantageous embodiment, the at least one flexible connecting element can be connected by means of elastic webs to the face of the at least one first planar segment. Such elastic webs can be structured by suitable shaping, for example, serpentine fingers, protrusions arranged transversely to the longitudinal extension, and the like, during the production of the circuit board, for example, by means of etching technology, laser cutting, and the like.
[0020] According to an advantageous embodiment, at least one opening can be provided in the at least one first planar segment, through which, in the intended installed state of the at least one flexible and rigid circuit boards, one or more components of the at least one rigid circuit board can be accessible. Therefore, components on the rigid circuit board cannot collide with the flexible circuit board when the flexible circuit board and rigid circuit board are brought into contact. The placement of the components on the rigid circuit board can be performed uninfluenced by the flexible connecting element installed later.
[0021] According to an advantageous embodiment, the flexible connecting element can directly adjoin the opening and the flexible connecting element can have an indentation, which is provided in the intended installed state as a contacting zone between the flexible circuit board and the rigid circuit board. The space occupied by the arrangement is thus reduced. The connection zone between flexible and rigid circuit boards can be precisely defined.
[0022] According to a further aspect, the present invention is directed to a circuit board arrangement having at least one flexible circuit board according to the present invention, the at least one flexible circuit board being clamped in a frame. This makes the handling of the flexible circuit board arrangement easier.
[0023] According to an advantageous embodiment, a plurality of first planar segments can be provided in a matrix-type arrangement, which first planar segments each comprise at least one flexible connecting element, which are each elastically connected to a face of the at least one first planar segment.
[0024] This embodiment allows a plurality of first planar segments of a flexible circuit board arrangement to be processed jointly, which reduces the throughput during the production of a flexible-rigid circuit board composite. The first planar segments of the flexible circuit board arrangement advantageously correspond to second planar segments of the rigid circuit board arrangement.
[0025] Through the elastic attachment of the respective flexible connecting element to the face of its planar segment, after a coarse pre-alignment of the flexible circuit board arrangement in relation to its connection partner, in particular, a rigid circuit board arrangement, a fine alignment of the respective flexible connecting elements to second planar segments of the rigid circuit board arrangement can be performed by machine. In particular, this can be performed by means of an optical alignment method on an x-y stage, on which the flexible and rigid circuit board arrangements laid one over another are laid, and in which a corresponding alignment movement of the flexible connecting element for fine alignment can be performed. For example, a vacuum suction unit can be applied to the flexible connecting element, which moves the flexible connecting element with optical monitoring to its end position in relation to the assigned second planar segment of the rigid circuit board arrangement.
[0026] According to a further aspect, the present invention is directed to a flexible-rigid circuit board composite made of at least one flexible circuit board according to the present invention and at least one rigid circuit board, the at least one flexible circuit board having at least one first planar segment, which interacts as intended with at least one second planar segment of the at least one rigid circuit board.
[0027] It is proposed that the at least one first planar segment comprises at least one flexible connecting element, which is elastically connected to a face of the at least one first planar segment.
[0028] The elastic connection or attachment of the flexible planar segment can advantageously be performed through corresponding shaping of connecting webs between the flexible planar segment and the face during the production of the flexible circuit board or circuit board arrangement.
[0029] In particular, the at least one flexible connecting element can be embedded within the face of the at least one first planar segment. Therefore, less complex manufacturing and handling of the flexible circuit board or circuit board arrangement is possible.
[0030] According to an advantageous embodiment, at least one opening can be provided in the at least one first planar segment, through which one or more components of the at least one rigid circuit board can be accessible. This allows placement of the components on the rigid circuit board or circuit board arrangement to be uninfluenced by later installation of the flexible circuit board or circuit board arrangement.
[0031] According to an advantageous embodiment, a contacting zone, in particular, a soldering zone, can be provided, the contacting zone being able to be arranged on an interface between the at least one flexible connecting element and the at least one opening. In this way, a precisely defined position of the contacting zone is available, which, in particular, in the case of an array of first planar segments allows automated fine alignment and automated production of soldered connections.
[0032] According to an advantageous embodiment, the at least one flexible circuit board and the at least one rigid circuit board can be formed by isolating planar segments, respectively, of a flexible and rigid circuit board arrangement. A plurality of in particular similar circuit board composites can thus be manufactured by machine.
[0033] According to a further aspect, the present invention relates to a method for producing a circuit board composite between a flexible circuit board according to the present invention and a rigid circuit board, the method being characterized by the following steps:
providing a flexible circuit board arrangement and a rigid circuit board arrangement, the flexible circuit board arrangement having at least one planar segment which has a flexible connecting element which is elastically connected to a face of the at least one first planar segment; bringing the flexible and rigid circuit board arrangements into contact with one another with a pre-alignment of the at least one first planar segment of the flexible circuit board arrangement in relation to at least one second planar segment of the rigid circuit board arrangement; finely aligning the at least one first planar segment in relation to the at least one second planar segment by adapting a position of the flexible connecting element at least parallel to or within the at least one first planar segment; connecting the at least one first planar segment to the at least one second planar segment; forming at least one circuit board composite by cutting out the connected first and second planar segments from the connected circuit board arrangements.
[0039] A method for connecting flexible connecting elements to rigid circuit boards can advantageously be provided, which can be carried out by machine. The method allows high throughput and precise alignment of flexible connecting elements in relation to rigid circuit boards.
[0040] The method can advantageously be carried out using typical facilities. The production of flexible-rigid circuit board composites can be performed more rapidly and cost-effectively. In particular, flexible-rigid circuit board composites having small dimensions, as are required in medical implants, can be provided.
[0041] According to an advantageous embodiment, the at least one second planar segment can have one or more components, in particular SMD components, which are prepared on their contact regions for a soldered connection, the connection of the first and second planar segments being able to be performed in a processing step with connection of the one or more SMD components to contact faces of the at least one second planar segment.
[0042] The arrangement made of flexible and rigid circuit board arrangements can be arranged fixed in place, i.e., a device for aligning and soldering moving in relation to the arrangement, or the arrangement made of flexible and rigid circuit board arrangements can be arranged so it is movable in relation to a fixed device for aligning and soldering, for example, on an x-y stage, which is movable in the x-direction and in the y-direction.
[0043] According to an advantageous embodiment, the at least one first planar segment, before the flexible and rigid circuit board arrangements are brought into contact with one another, can be pre-equipped with one or more components, in particular SMD components, for example, capacitors, feedthroughs, circuits, and the like. The method according to the present invention and the embodiment according to the present invention of the flexible circuit board arrangement allow great design freedom.
[0044] According to a further aspect, the present invention also relates to a device for carrying out the method according to the present invention for producing a circuit board composite between a flexible circuit board and a rigid circuit board, having at least one flexible circuit board, with at least the following steps being able to be performed:
finely aligning the at least one first planar segment in relation to the at least one second planar segment by adapting a position of the flexible connecting element at least parallel to or within the at least one first planar segment; and connecting the at least one first planar segment to the at least one second planar segment.
[0047] The device advantageously allows automated handling in parallel of multiple flexible connecting element simultaneously, which are connected to rigid circuit boards in an automated manner. The production costs are reduced in comparison to production costs in the case of single part handling. The general piece costs of a production method of hybrid structures having cost-effective rigid circuit boards and flexible connecting elements of flexible circuit boards are reduced. Through the automation of the method, error rates can be reduced and the product output can be increased.
[0048] It is advantageously possible to make so-called tape automated bonding (TAB), a contacting method for semiconductor chips, which allows rapid automated installation directly on the circuit board, usable in such a circuit board composite.
[0049] Further features, aspects, objects, advantages, and possible applications of the present invention will become apparent from a study of the exemplary embodiments and examples described below, in combination with the figures, and the appended claims.
DESCRIPTION OF THE DRAWINGS
[0050] The present invention is explained in greater detail hereafter for exemplary purposes on the basis of exemplary embodiments shown in drawings. In the schematic figures:
[0051] FIG. 1 shows an exploded view of an exemplary embodiment of a rigid circuit board arrangement having an array of preinstalled components and a flexible circuit board arrangement having an array of flexible connecting elements according to the present invention;
[0052] FIG. 2 shows, in the assembled state, the rigid circuit board arrangement and the flexible circuit board arrangement from FIG. 1 ;
[0053] FIG. 3 shows an isolated flexible-rigid circuit board composite according to the exemplary embodiment of FIG. 1 ;
[0054] FIG. 4 shows a detail view of an embodiment of a first planar segment having a flexible connecting element, which is elastically connected using serpentine webs to a face of the first planar segment;
[0055] FIG. 5 shows a detail view of a further exemplary embodiment of a first planar segment having a flexible connecting element, which is elastically connected using wavy webs to a face of the first planar segment;
[0056] FIG. 6 shows a detail view of a further exemplary embodiment of the first planar segment having a flexible connecting element, which is elastically connected using bridge-type webs to a face of the first planar segment; and
[0057] FIG. 7 shows a detail view of a further exemplary embodiment of a first planar segment having a flexible connecting element, which is elastically connected using zigzag webs to a face of the first planar segment.
DETAILED DESCRIPTION
[0058] In the figures, functionally identical or identically acting elements are each identified by the same reference numerals. The figures are schematic illustrations of the present invention. They illustrate non-specific parameters of the present invention. Furthermore, the figures merely illustrate typical embodiments of the present invention and are not to restrict the present invention to the embodiments shown.
[0059] To explain the present invention, FIG. 1 shows an exploded view of an exemplary embodiment of a flexible circuit board arrangement 110 having a matrix-type arrangement (array) of first planar segments 120 , of which each planar segment 120 has a flexible connecting element 150 , and a rigid circuit board arrangement 210 having a corresponding array of second planar segments 220 , each of which comprises preinstalled components 250 . FIG. 2 shows, in the assembled state, the flexible circuit board arrangement 100 and the rigid circuit board arrangement 200 from FIG. 1 . The flexible circuit board arrangement 110 is formed, for example, from a plastic, e.g., polyimide and the like.
[0060] First and second planar segments 120 , 220 , which are connected to one another, form in each case a flexible-rigid circuit board composite 300 , which is obtained by cutting off (isolation) from the connected circuit board arrangements 110 , 210 . FIG. 3 shows a flexible-rigid circuit board composite 300 according to the exemplary embodiment of FIG. 1 , which is formed by isolating the planar segments 100 , 200 .
[0061] For example, the rigid circuit board arrangement 210 comprises an array of six second planar segments 220 , each having a number of components 250 , in particular, surface-mounted components (SMD components), while the flexible circuit board arrangement 110 comprises an array of six first planar segments 120 each having a flexible connecting element 150 . One skilled in the art will appreciate that the numbers of planar segments may vary, and the present invention is not limited to six on each circuit board arrangement.
[0062] The flexible circuit board arrangement 110 is integrated for better handling in a unit 114 and clamped in a frame 102 of the unit 114 . Markings 104 in the flexible circuit board arrangement 110 , e.g., in the form of openings, correspond to markings 204 of the rigid circuit board arrangement 210 . These are used for the coarse alignment of the two circuit board arrangements 110 , 210 to one another. The alignment can be performed using optical image recognition, for example.
[0063] Markings 162 on the respective flexible connecting elements 150 (only identified on two first planar segments 120 in the figures) correspond to markings 262 of the second planar segments 220 . These markings 162 , 262 are used for the fine alignment of the flexible connecting elements 150 in relation to the planar segments 220 . The alignment can be performed using optical image recognition, for example.
[0064] Markings 106 on the unit 114 can be used for the initial coarse alignment of the unit 114 in relation to the second circuit board arrangement 210 .
[0065] Each first planar segment 120 of the flexible circuit board arrangement 110 has, adjacent to the respective flexible connecting element 150 , an opening 130 , through which the components 250 of the rigid circuit board arrangement 210 are accessible. The components 250 on the rigid circuit board arrangement 210 , which are preinstalled on the planar segments 220 , can protrude through the opening 130 , without being disturbed by the flexible circuit board arrangement 110 , or its contact arrangements. In particular, the flexible circuit board arrangement 110 is implemented so that the components 250 on the rigid circuit board arrangement 210 do not interfere with the arrangement of the contact arrangement of the flexible circuit board arrangement 110 , via which it is connected to the rigid circuit board arrangement 210 . The flexible connecting element 150 is elastically connected to a face of the planar segment 120 , which allows a fine alignment of the flexible connecting element 150 during the connection step, in that the flexible connecting element 150 is aligned in narrow boundaries in the plane of the first planar segment 120 .
[0066] The arrangement in FIG. 2 shows the combination of the flexible circuit board arrangement 110 with the rigid circuit board arrangement 210 , prealigned and ready for laying on an x-y stage, and a device for carrying out the fine alignment of the respective flexible connecting elements 150 and for producing the soldered connection.
[0067] In order to execute the connection, the rigid circuit board arrangement 210 , which is prepared for the soldered connection by being previously tin plated and provided with flux on the contact faces, is brought into contact with the flexible circuit board arrangement 110 and laid on the x-y stage of the device (not shown). The device is programmed to position the combination under a unit for the alignment and soldered connection. The unit can comprise an image recognition mechanism, for example, so that the alignment can be performed automatically by image recognition. This unit has a vacuum gripper on a fine alignment head, using which the elastically attached flexible connecting element 150 can be moved within narrow boundaries, in order to align it precisely to the corresponding region of the rigid circuit board arrangement with assistance of the image recognition system. If the flexible connecting element 150 is precisely aligned, the connecting is performed by means of a hot bar soldering tool or a laser soldering tool, for example.
[0068] Of course, it is also conceivable to mount the combination of the flexible and rigid circuit board arrangements 110 , 210 in a stationary manner and to move the unit for alignment and soldered connection in relation thereto using a corresponding x-y stage or a robot arm, on the other hand.
[0069] If the soldered connection between the flexible and rigid circuit board arrangements 110 , 210 has been executed, isolation of the array can be performed, for example, by means of laser cutting or mechanical methods.
[0070] FIGS. 4-7 show detail views of exemplary embodiments of a first planar segment 120 having a flexible connecting element 150 , which is elastically connected to a face 122 of the first planar segment 120 . The planar segment 120 is part of the flexible circuit board 100 , in particular.
[0071] The flexible connecting element 150 has a face 152 , which is essentially aligned with the face 122 and is elastically attached to this face 122 . Components can be arranged in an inner region 154 . For example, a feedthrough 160 having contact pins arranged perpendicularly (to the plane of the drawing) is shown. Furthermore, two markings 162 are provided in the inner region 154 , which correspond to markings 262 (see FIG. 1 ) of the corresponding second planar segment 220 (see FIG. 1 ) of the rigid circuit board arrangement 210 (see FIG. 1 ) and which allow a fine alignment.
[0072] The flexible connecting element 150 has, in this exemplary embodiment, a T-shaped footprint having a crossbeam 156 and a web 158 arranged transversely thereto, with the feedthrough 160 being arranged on the end opposite to the crossbeam 156 . The crossbeam 156 has a recess on its free end, which forms a contact zone 140 , on which the connection between the flexible connecting element 150 and the second planar segment 220 is produced. The connection between the flexible circuit board arrangement 110 and the rigid circuit board arrangement 210 or the flexible circuit board 100 and the rigid circuit board 200 is thus also produced (see FIG. 3 ).
[0073] The contact zone 140 is arranged on an interface 142 between the flexible connecting element 150 and an opening 130 , through which in case of contact the components 250 (see FIGS. 2-3 ) of the rigid circuit board arrangement 210 /circuit board 200 can protrude. The contour 132 of the opening is adapted to the corresponding dimensions of the second planar segment 210 (see FIGS. 2-3 ).
[0074] A trench 170 is arranged between the face 122 of the first planar segment 120 and the face 152 of the flexible connecting element 150 , which separates the two faces 152 , 122 from one another and permits a movement of the flexible connecting element 150 relative to the face 122 .
[0075] A plurality of connecting webs 172 extends between the edges of the trench 170 , whose shaping allows them to be elastic and allows a lateral movement of the connecting element 150 within the plane or parallel to the surface of the first planar segment 120 .
[0076] In FIG. 4 , the connecting webs 172 are implemented as serpentine fingers arranged in parallel. In FIG. 5 , the connecting webs 172 are implemented as wavy fingers arranged in parallel. In FIG. 6 , the connecting webs 172 are implemented as H-shaped elements arranged in parallel. In FIG. 7 , the connecting webs 172 are implemented as zigzag fingers arranged in parallel. Of course, the connecting webs 172 can also have other shapes. These structures may be produced easily during the production of the flexible circuit board arrangement 110 by typical structuring methods.
[0077] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof.
[0078] Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range.
LIST OF REFERENCE NUMERALS
[0000]
100 flexible PCB
102 frame
104 marking
106 marking
110 circuit board arrangement
114 unit
120 planar segment
122 face
130 opening
132 edge
140 region
142 interface
150 flexible connecting segment
152 face
156 transverse element
154 web
160 planar region
162 marking
170 trench
172 elastic web
200 rigid PCB
204 marking
210 circuit board arrangement
220 planar segment
250 component
262 marking
300 circuit board composite
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A flexible circuit board for producing a flexible-rigid circuit board composite made of at least one flexible circuit board and at least one rigid circuit board, the at least one flexible circuit board having at least one first planar segment, which interacts as intended in the installed state with at least one second planar segment of the at least one rigid circuit board, wherein the at least one first planar segment comprises at least one flexible connecting element, which is elastically connected to a face of the at least one first planar segment. Furthermore, a flexible-rigid circuit board composite is provided having at least one flexible circuit board, a flexible-rigid circuit board arrangement, and a method and a device for producing a flexible-rigid circuit board composite.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from India Application Serial No 1640/CHE/2010, filed on Jun. 14, 2010, entitled Process for the Preparation of Gabapentin, which application is assigned to the same assignee as this application and whose disclosure is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a new process for converting gabapentin acid salts to gabapentin.
BACKGROUND OF THE INVENTION
[0003] Gabapentin is chemically, 1-(aminomethyl)-1-cyclohexane acetic acid, having the structure shown below:
[0000]
[0004] Gabapentin is useful in treating epilepsy and various other cerebral disorders. It was first described by Warner-Lambert Co. in U.S. Pat. No. 4,024,175.
[0005] Several processes for the preparation of gabapentin are reported in the literature. U.S. Pat. No. 4,024,175 describes three methods to prepare gabapentin. All the methods result in gabapentin hydrochloride salt, which is converted to free gabapentin by treatment with a basic ion-exchange resin. U.S. Pat. No. 4,894,476 discloses a hydrated gabapentin which is prepared by liberating the free gabapentin base from its hydrochloride salt by pouring the salt solution onto a column of ion exchange resin like Amberlite IRA-68, eluting with deionised water and further work up to recover the hydrated form. U.S. Pat. No. 5,091,567 discloses the conversion of the gabapentin hydrochloride salt to gabapentin base by passing through a weakly basic anion exchanger. Gabapentin is manufactured in ton lot quantities and a preparative column chromatography is not convenient for applications on an industrial scale. It requires long time and results in a large volume of aqueous solution to be evaporated at low temperature, which makes the process cumbersome and uneconomical.
[0006] A process for the conversion of gabapentin hydrochloride to free gabapentin is described in the U.S. Pat. No. 6,255,526 B1. In this process, gabapentin hydrochloride is dissolved in a solvent such as ethyl acetate, in which free gabapentin is insoluble. An alkyl amine such as tributylamine is added to precipitate gabapentin, which is insoluble in the solvent and is recovered by filtration. Alkyl amine hydrochloride, formed in the reaction being soluble in the solvent, will remain in solution. Here, gabapentin is obtained as Form III and again has to be converted to Form II, which is the generic form. In addition to ethylacetate, the patent also mentions benzyl alcohol as a solvent and gives 43% yield of gabapentin (Table-1, Example 11). It is clear that only 43% gabapentin precipitates out from the solution and the remaining 57% remains in the solution. With only 43% yield, the process is uneconomical. Thus, benzyl alcohol is not a suitable solvent for this process.
[0007] U.S. Pat. No.7,439,387 B2 describes the conversion of gabapentin hemisulphate salt to free gabapentin by treating with alkyl amines such as triethylamine or diisopropyl ethyl amine. In all these cases, the alkyl amines used are nonvolatile liquids and are difficult to remove, requiring repeated extractions.
[0008] U.S. Pat. No. 7,196,216 describes the conversion of gabapentin hydrochloride first to free base and then to its sulphate salt which is further treated with an inorganic base to obtain free gabapentin. The patent also describes the use of barium hydroxide as one of the inorganic bases which converts sulphate salt to free gabapentin. The process is cumbersome and involves a number of steps. Further use of barium hydroxide introduces toxic barium ions into the product at the final stages and requires extensive purification steps. Indian patent No. 186285 describes a process to convert gabapentin hydrochloride to gabapentin directly by treating with aqueous sodium hydroxide or other inorganic bases. U.S. Pat. Application No. US 2006/0149099 also describes a similar process and defines specific amounts of water and the alkali metal base to be used. Here, the reaction mixture is heated to 50-90° C., preferably at 60-70° C. This results in the formation of lactam to a significant extent and a method to recover lactam from the mother liquor is described (Mother liquor B, Example 1). Gabapentin obtained by these methods show high amounts of chloride, which is mainly from sodium chloride formed during neutralization with sodium hydroxide. Extensive purification steps are required to remove the chlorides.
[0009] Thus there is a need for a good process to convert gabapentin acid salt to free gabapentin which is free from anionic and other impurities.
SUMMARY OF THE INVENTION
[0010] Hitherto the approach has been to utilize a solvent in which either the gabapentin acid salt or the free gabapentin is soluble, so that when the salt is neutralized by an alkaline reagent, only one of them will be in solution and the other precipitated facilitating separation. This invariably depended on efficient solubility which influenced the overall recovery of the free gabapentin. In addition, none of these processes could efficiently remove the inorganic byproduct of the process from the resulting gabapentin. A solvent in which both the gabapentin acid salt and the free base are soluble but the alkali salt byproduct is insoluble might provide an alternative resulting in low inorganic anion content.
[0011] While studying the process described in U.S. Pat. No. 6,255,526 B1, we found that surprisingly benzyl alcohol dissolves both gabapentin acid salts and free gabapentin to a significant extent. Further experimentation with various solvents revealed that nitrobenzene also dissolves both gabapentin salts and free gabapentin to a significant extent.
[0012] We have utilized this unique property and have developed a novel, industrially useful process for the conversion of gabapentin hydrochloride and other salts to gabapentin. The invention avoids the disadvantages associated with the earlier methods. The process consists of dissolving gabapentin salt in benzyl alcohol or nitrobenzene and stirring the solution with finely powdered solid alkali base, which is not soluble in these solvents. Gabapentin acid salt reacts with the alkaline base and the gabapentin generated will remain in the solution. Inorganic salts, formed during the neutralization and being insoluble, are removed by filtration along with the excess alkali. The clear filtrate is treated with an anti-solvent, such as methyl t-butyl ether (MTBE), ethyl acetate (EtOAc), toluene, acetone or methylene chloride and the precipitated pure gabapentin is collected by filtration. It was found that the clear filtrate of benzyl alcohol or nitrobenzene can also be extracted with water. Pure gabapentin can be obtained by removing water under vacuum by evaporation or distillation.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention provides a process for the conversion of gabapentin acid salt to free gabapentin which comprises:
(i) treating gabapentin acid salt with an organic solvent in which both gabapentin salt and free gabapentin are soluble; (ii) treating the organic phase with a solid anhydrous alkali base and stirring until the pH of the solution is 7.0 to 7.5; (iii) filtering the solution to remove alkali salt formed during neutralization and any unreacted solid alkali and treating the filtrate with a suitable drying agent, if necessary, and filtering to remove the drying agent; (iv) treating the filtrate with an anti-solvent to precipitate gabapentin free base, filtering the precipitate; and (v) stirring gabapentin obtained in step (v) using a suitable alcoholic solvent.
[0019] Gabapentin hydrochloride can be prepared by one of the methods described in the literature, for example U.S. Pat. Nos. 4,024,175 or 4,152,326. Gabapentin sulphate can be prepared as described in U.S. Pat. No.7,439,387 B2. It is dissolved in benzyl alcohol or nitrobenzene or in any other suitable organic solvent in which free gabapentin is also soluble. Such solvents being immiscible with water offer another important advantage. The aqueous solution of gabapentin hydrochloride obtained after Hoffmann rearrangement from cyclohexane diacetic acid monoamide (CDMA), in the popular route of synthesis, can be directly extracted from the reaction mixture with the selected solvent as for example benzyl alcohol or nitrobenzene. The solution is then treated with finely powdered solid alkali base such as sodium carbonate, potassium carbonate or potassium hydroxide and stirred till the solution is rendered neutral to pH. Gabapentin acid salt which is in solution reacts with the solid base in a biphasic manner. The liberated free gabapentin remains in solution and the inorganic salt such as sodium chloride formed during the neutralization is insoluble and is precipitated. The reaction is slow because of the biphasic nature of the reaction system and may take several hours for complete neutralization. Other bases in solid form, such as NaOH, KOH, LiOH, Ca(OH) 2 , Mg(OH) 2 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 , CaCO 3 , Ce 2 CO 3 , NaHCO 3 , KHCO 3 or mixtures containing these can also be used. The process was also successfully extended to gabapentin sulfate since it is also soluble in the selected solvents, such as benzyl alcohol and nitrobenzene. Filtering the solution removes the inorganic salt formed during the neutralization and also the unreacted alkali base. The clear filtrate is treated with an anti-solvent, such as methyl tert.butyl ether and the solution is stirred until gabapentin precipitates completely. Filtering the suspension gives gabapentin free base. Stirring at a lower temperature such as at 0-5° C. gives higher yields. The presence of moisture results in lower yields, which may be caused by the highly hygroscopic nature of some of the solid bases. One can overcome the problem of moisture in the solution by stirring the solution with a dehydrating agent, such as sodium sulfate, molecular sieves, etc.
[0020] Instead of treating with an anti-solvent, the filtrate can also be extracted with water. Gabapentin has a higher solubility in water than in benzyl alcohol or nitrobenzene and is easily extracted into water. Removal of water under reduced pressure gives gabapentin, which can be converted to the desired form by known methods.
[0021] Gabapentin obtained either by using anti-solvent or by extraction with water is stirred in alcoholic solvents, such as methanol (MeOH), ethanol, isopropyl alcohol (IPA), or a mixture of MeOH-IPA-water. This will help in removing the traces of benzyl alcohol and other impurities. This process directly yields the generic Form II polymorph of gabapentin of very high purity (>99.5%) and is free from anionic impurities. Since the reaction conditions are mild and efficient, the product obtained is completely free from the lactam impurity.
[0022] The embodiments of the present invention are further described in the following examples, which are not intended in any way to limit the scope of the invention.
EXAMPLE-1
[0023] Gabapentin hydrochloride (50 g, 0.24 mol) was dissolved in benzyl alcohol (335 ml) at room temperature. Finely powdered sodium carbonate (25.4 g, 0.23 mol) was added, and the reaction mixture was stirred until the solution pH reaches 7.0 to 7.5. It will take about 2 to 3 hours. The suspension was filtered and the residue washed with about 15 ml benzyl alcohol. The clear filtrate was cooled to 0-5° C. and 700 ml of methyl tert.butyl ether (MTBE) was added. The solution was stirred for one hour and the precipitated gabapentin filtered. The crude gabapentin was washed with MTBE and stirred in ethanol to remove traces of benzyl alcohol to obtain pure gabapentin. Yield: 36.7 g (90%), HPLC: 99.7%, chloride content: 22 ppm, lactam content: 0.01%.
EXAMPLE-2
[0024] Gabapentin hemi-sulfate hemihydrate (10 g, 0.043 mol) was dissolved in benzyl alcohol (70 ml) at room temperature. Finely powdered sodium carbonate (4.63 g, 0.043 mol) was added and the reaction mixture was stirred until the solution pH reaches 7.0 to 7.5. It will take about 2 to 3 hours. The suspension filtered and the residue washed with about 5 ml benzyl alcohol. The clear filtrate was cooled to 0-5° C. and 140 ml of methyl tert.butyl ether (MTBE) was added. The solution was stirred for one hour and the precipitated gabapentin filtered. The crude gabapentin was washed with MTBE and stirred in ethanol to remove traces of benzyl alcohol to obtain pure gabapentin. Yield: 5.49 g (73.5%), HPLC: 99.5%.
EXAMPLE-3
[0025] Gabapentin hydrochloride (10 g, 0.048 mol) was dissolved in benzyl alcohol (70 ml) at room temperature. Finely powdered potassium hydroxide (2.7 g, 0.048 mol) was added and the reaction mixture was stirred till the solution pH reaches 7.0 to 7.5. It will take about 2 to 3 hours. The suspension was filtered and the residue washed with about 5 ml benzyl alcohol. The clear filtrate was cooled to 0-5° C. and 140 ml of methyl tert.butyl ether (MTBE) was added. The solution was stirred for one hour and the precipitated gabapentin filtered. The crude gabapentin was washed with MTBE and stirred in ethanol to remove traces of benzyl alcohol to obtain pure gabapentin. Yield: 6.9 g (84%), HPLC: 99.6%.
EXAMPLE-4
[0026] Gabapentin hemi-sulphate hemihydrate (10 g, 0.043 mol) was dissolved in nitrobenzene (100 ml) at room temperature. Finely powdered potassium carbonate (6.04 g, 0.043) was added and the reaction mixture was stirred until the solution pH reaches 7.0 to 7.5. After about 2 to 3 hours the suspension was filtered and the residue washed with about 5 ml nitrobenzene. The clear filtrate was cooled to 0-5° C. and 150 ml of methyl tert.butyl ether (MTBE) was added. The solution was stirred for one hour and the precipitated gabapentin filtered. The crude gabapentin was washed with MTBE and stirred in ethanol to remove traces of benzyl alcohol to obtain pure gabapentin. Yield: 4.56 g (61%), HPLC: 99.6%.
EXAMPLE-5
[0027] Gabapentin hydrochloride (10 g, 0.048 mol) was dissolved in benzyl alcohol (70 ml) at room temperature. Finely powdered potassium carbonate (6.65 g, 0.048 mol) was added and the reaction mixture was stirred until the pH of solution reaches 7.0 to 7.5. After about 2 to 3 hours the suspension was filtered and the residue washed with about 5 ml benzyl alcohol. Filtrate was extracted with water (30 ml×2). Water layer was washed with ethyl acetate to remove traces of benzyl alcohol. The aqueous layer was concentrated under reduced pressure at 45° C. to obtain crude gabapentin. Stirring in ethanol resulted in pure gabapentin. Yield: 6.5 g (79%), HPLC: 99.8%.
EXAMPLE-6
[0028] Cyclohexane diaceticacid monoamide (20 g, 0.1 mol) was dissolved in 4 N NaOH solution (30 ml) at 15-20° C. To this 100 ml of a solution of 7-8% sodium hypochlorite and 10.2 g sodium hydroxide were added and stirred for 5 h. Excess hypochlorite was neutralized by 1 g sodium metabisulphite solution. The solution was acidified to pH 2 by HCl. The aqueous solution was extracted with benzyl alcohol (40 ml×2). The organic layer was dried over anhydrous Na 2 SO 4 . Finely powdered sodium carbonate (10.65 g, 0.1 mol) was added and the reaction mixture was stirred until the solution pH reaches 7.0 to 7.5. It will take about 2 to 3 hours. The suspension was filtered and the residue washed with about 5 ml benzyl alcohol. The clear filtrate was cooled to 0-5° C. and 160 ml of methyl tert.butyl ether (MTBE) was added. The solution was stirred for one hour and the precipitated gabapentin filtered. The crude gabapentin was washed with MTBE and stirred in ethanol to remove traces of benzyl alcohol to obtain pure gabapentin. Yield: 11.8 g (68.6% based on CDMA), HPLC: 99.6%.
EXAMPLE-7
[0029] Cyclohexane diaceticacid monoamide (20 g, 0.1 mol) was dissolved in 4N NaOH solution (30 ml) at 15-20° C. To this 100 ml solution of 7-8% sodium hypochlorite and 10.2 g sodium hydroxide were added and stirred for 5 h. Excess hypochlorite was neutralized by 1 g sodium metabisulphite solution. The solution was acidified to pH 2 by HCl. The aqueous solution was extracted with benzyl alcohol (40 ml×2). The organic layer was dried over anhydrous Na 2 SO 4 . Finely powdered sodium carbonate (10.65 g, 0.1 mol) was added and the reaction mixture was stirred until the solution pH reaches 7.0 to 7.5. It will take about 2 to 3 hours. The suspension filtered and the residue washed with about 5 ml benzyl alcohol. The organic solution was extracted with water (60 ml). The layer was separated and washed with ethyl acetate to remove traces of benzyl alcohol.
[0030] The aqueous layer was concentrated to obtain crude gabapentin. Stirring in ethanol resulted in pure gabapentin. Yield: 10.14 g (59% based on CDMA), HPLC: 99.6%.
[0031] Without further elaboration the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.
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This invention discloses a process for converting gabapentin acid salt to free gabapentin, where the salt is dissolved in an organic solvent in which both gabapentin acid salt and free gabapentin are soluble. The solution is treated with a powdered alkaline base to liberate free gabapentin which will remain in solution. The insoluble alkali salt of the acid is removed by filtration. From the filtrate free gabapentin is obtained either by adding anti-solvent or by extraction with water.
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TECHNICAL FIELD
The present application relates to a booklet maker or sheet folding apparatus, as would be used in conjunction with a printing or copying apparatus.
BACKGROUND
Booklet makers and sheet folders are well-known devices for forming folded booklets or folded sheet sets. It is becoming common to include booklet makers and sheet folders in conjunction with office-range copiers and printers (as used herein, a “copier” will be considered a type of “printer”). In basic form, a booklet maker/sheet folder includes a slot for accumulating signature sheets, as would be produced by a printer. In booklet mode, the accumulated sheets, forming the pages of a booklet, are positioned within the stack so that a stapler mechanism and complementary anvil can staple the stack precisely along the intended crease line. In one embodiment, the creased and stapled sheet sets are then pushed, by a blade, completely through crease rolls, to form the final main fold in the finished booklet. The basic hardware of a booklet maker, such as including the crease rolls, can be controlled to provided C- or Z-folds to sheets or sets of sheets as well. The finished booklets or sheets are then accumulated in a tray downstream of the crease rolls.
Whether the final product of a booklet maker is a multi-page booklet, or a folded sheet or set of sheets, if it is desired to mail the product without an envelope, it is known to place a sticker on an edge of the product to prevent the booklet or folded sheet from opening or unfolding in the mail.
PRIOR ART
U.S. Pat. No. 5,980,676 discloses a finishing device for a copier or digital printer which places tapes along the edges of output sheet sets.
SUMMARY
According to one embodiment, there is provided an apparatus for processing sheets, comprising a roller pair forming a main nip therebetween, the roller pair being operable to move at least one sheet through the main nip in a process direction and a reverse direction opposite the process direction. A sticker applicator is operatively disposed upstream of the main nip along the process direction. A control system, operative of the roller pair and the main nip, causes the roller pair to move a sheet in the reverse direction to receive a sticker from the sticker applicator, and then to move the sheet through the main nip in the process direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified elevational view of a “finisher module,” including a booklet maker, as would be used with an office-range digital printer.
FIG. 2 is a simplified elevational view, showing an embodiment of a sticker applicator in conjunction with folding hardware.
DETAILED DESCRIPTION
FIG. 1 is a simplified elevational view of a “finisher module,” generally indicated as 100 , including a sheet folder and booklet maker, as would be used with an office-range digital printer. Printed signature sheets from the printer 99 are accepted in an entry port 102 . Depending on the specific design of finisher module 100 , there may be numerous paths such as 104 and numerous output trays 106 for print sheets, corresponding to different desired actions, such as stapling, hole-punching and C- or Z-folding. It is to be understood that the various rollers and other devices which contact and handle sheets within finisher module 100 are driven by various motors, solenoids and other electromechanical devices (not shown), under a control system, such as including a microprocessor (not shown), within the finisher module 100 , printer 99 , or elsewhere, in a manner generally familiar in the art. For present purposes what is of interest is the booklet maker generally indicated as 110 , the basic hardware of which can be used in other types of folding as well.
Booklet maker 110 defines a slot 112 . Slot 112 accumulates signature sheets (sheets each having typically four page images thereon, for eventual folding into pages of the booklet) from the printer 99 . Each sheet is held within slot 112 at a level where a stapler 114 can staple the sheets along a midline of the signatures, the midline corresponding to the eventual crease of the finished booklet. In order to hold sheets of a given size at the desired level relative to the stapler 114 , there is provided at the bottom of slot 112 an elevator 116 , which forms the “floor” of the slot 112 on which the edges of the accumulating sheets rest before they are stapled. The elevator 116 is placed at different locations along slot 112 depending on the size of the incoming sheets.
As printed signature sheets are output from printer 99 , they accumulate in slot 112 . When all of the necessary sheets to form a desired booklet are accumulated in slot 112 , elevator 116 is moved from its first position to a second position where the midpoint of the sheets are adjacent the stapler 114 . Stapler 114 is activated to place one or more staples along the midpoint of the sheets, where the booklet will eventually be folded.
After the stapling, elevator 116 is moved from its second position to a third position, where the midpoint of the sheets are adjacent a blade 14 and crease rolls 10 and 12 , which form a crease nip 16 . The action of blade 14 and crease rolls 10 and 12 performs the final folding, and sharp creasing, of the sheets into the finished booklet. Blade 14 contacts the sheet set along the stapled midpoint thereof, and bends the sheet set toward the nip of crease rolls 10 and 12 , which draw all the sheets in and form a sharp crease. The creased and stapled sheet sets are then drawn, by the rotation of crease rolls 10 and 12 , completely through the nip, to form the final main fold in the finished booklet. The finished booklets are then conducted along path 122 and collected in a tray 124 .
The basic hardware of a finisher as shown in FIG. 1 , especially as regards booklet maker 110 , can also be controlled to create C-, and in some cases, Z-folds in sheets or sets of sheets.
FIG. 2 is an elevational view of a sticker applicator that can be used with the basic hardware shown in FIG. 1 . As can be seen, downstream of crease rolls 10 , 12 along a basic process direction (indicated as P) of the finisher module is what can be called a roller pair 20 , 22 , together forming what can be called a main nip 24 . In this embodiment, the rollers 20 , 22 are selectably controllable (through a control system and motors, not shown) to direct a sheet S disposed in main nip 24 either in the process direction P (i.e., toward the output tray, or to the right in the Figure) or, as needed, in a reverse direction opposite the process direction P (i.e., toward the crease nip 16 , or toward the left in the Figure). In this way, as part of a process, the rollers 20 , 22 can “back up” a folded sheet or set of sheet some distance as needed at certain times.
In FIG. 2 , a sheet indicated as S, which in this view has emerged from folding through crease nip 16 and is disposed in main nip 24 , can in practice be a single sheet, or set of sheets, which has been folded once or in a C- or Z-shape, or can be a multi-sheet, and possibly stapled, booklet. (In any case, for present purposes, a booklet or other folded set of sheets will include at least one sheet.) The trailing edge of such a sheet S along the process direction P is “open,” or in other words, not a fold line, and therefore, once the sheet exits the system and is mailed, the sheet is liable to unfold. It is therefore desirable to place a sticker over the open, trailing edge of the sheet S, in effect to keep the sheet folded or the booklet closed.
Disposed between crease rolls 10 , 12 and roller pair 20 , 22 is what can generally be called a sticker applicator 30 . The applicator 30 provides stickers (such as small pieces of paper or tape, having adhesive on one side thereof) and applies the stickers to the trailing edge (relative to process direction P) of a sheet S held in main nip 24 .
The sticker applicator 30 in this embodiment includes a dispenser having a supply spool 32 for retaining a supply of stickers on substrate such as backing tape, and take-up spool 34 for taking up the tape as sticker are removed. As shown, the sticker-bearing tape is threaded around a pin 36 , which causes a sharp turn in the motion of the backing tape BT; as the backing tape BT makes the sharp turn, a single sticker ST is effectively peeled from the backing tape and disposed along the path of a sheet S. The backing tape BT would typically be pulled by a friction roller nip (not shown) associated with take-up spool 34 . Because of the large variation in diameter of the take-up spool 34 over the course of its use, it is preferably over-driven with a slipping drive. The main body of sticker applicator 30 can be in the form of an easily replaceable cartridge, so that a spent roll of backing tape on take-up spool 34 can be quickly replaced with a new roll of backing tape on supply spool 32 .
Because a sticker ST must be placed on a trailing edge of a sheet passing mainly through the process direction, the roller pair 20 , 22 is controlled to momentarily “back up” the sheet S so that the trailing edge of the sheet S is pushed against the sticky (toward the right in the Figure) side of the sticker ST. At an appropriate moment, the applicator interposes a sticker ST in a path of a folded sheet S moving in the reverse direction. In one embodiment, the sheet S can be backed up to such an extent that the sticker ST is placed on the trailing edge and the trailing edge is backed up into crease nip 16 , where the sticker ST is folded down by the crease nip 16 over the trailing edge of sheet S. In this embodiment, the crease rolls 10 , 12 function both to perform a main fold in the sheet S as it moves in the process direction and fold the sticker ST when the sheet moves in the reverse direction. Once the sticker ST is placed on and folded over the trailing edge of sheet S, the direction of roller pair 20 , 22 is again reversed to push the sheet through the process direction (to the right in the Figure) and to an output tray as desired.
In a practical application of the apparatus in FIG. 2 , the spooling of the backing tape BT around pin 36 is coordinated with the motion of a sheet or booklet past sticker applicator 30 so that, at times in the process when the sheet S is moving in the process direction past the sticker applicator 30 , a sticker ST is not peeled off and placed in the path; rather, the sticker ST is peeled from the backing tape and placed in the path only at such time as the roller pair 20 , 22 is “backing up” the sheet S to receive the sticker. This coordination of the actions of applicator 30 (in particular, of take-up spool 34 ) with the motion of a sheet S can be carried out by precise timing of the motion of the hardware, or with a mechanical or optical feedback system (not shown) governing the motion of the backing tape and/or the sheet S. An optical feedback system governing the backing tape BT could exploit, for instance, synchronization marks or holes on the backing tape BT, such as between each sticker ST.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
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In a finishing apparatus, such as would be used with a copier or high-speed printer, an applicator places stickers on a folded sheet or booklet, to prevent the sheet or booklet from unfolding or opening. At one point in the operation, the folded sheet or booklet is “backed up” in its basic process direction to receive a sticker on its trailing edge, and backed up further so that the sticker is folded over the trailing edge by a pair of crease rolls.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 10/968,763 filed on Oct. 19, 2004 now U.S. Pat. No. 7,104,379.
FIELD OF THE INVENTION
The present invention relates generally to power transfer systems and, more particularly, to torque transfer mechanisms having a clutch actuator for actuating a clutch assembly in a power transfer system.
BACKGROUND OF THE INVENTION
Power transfer systems of the type used in motor vehicles including, but not limited to, four-wheel drive transfer cases, all-wheel drive power take-off units (PTU), limited slip drive axles and torque vectoring drive modules are commonly equipped with a torque transfer mechanism. In general, the torque transfer mechanism functions to regulate the transfer of drive torque between a rotary input component and a rotary output component. More specifically, a multi-plate friction clutch is typically disposed between the rotary input and output components and its engagement is varied to regulate the amount of drive torque transferred therebetween.
Engagement of the friction clutch is varied by adaptively controlling the magnitude of a clutch engagement force that is applied to the multi-plate friction clutch via a clutch actuator system. Many traditional clutch actuator systems include a power-operated drive mechanism and an operator mechanism. The operator mechanism typically converts the force or torque generated by the power-operated drive mechanism into the clutch engagement force which, in turn, can be further amplified prior to being applied to the friction clutch. Actuation of the power-operated drive mechanism is controlled based on control signals generated by a control system.
Currently, a large number of the torque transfer mechanisms used in motor vehicle driveline applications are equipped with an electrically-controlled clutch actuator that can regulate the drive torque transferred as a function of the value of the electric control signal applied thereto. In some applications, an electromagnetic device is employed as the power-operated drive mechanism of the clutch actuator. For example, U.S. Pat. No. 5,407,024 discloses use of an electromagnetic coil that is incrementally activated to control movement of a ballramp operator mechanism for applying the clutch engagement force to the friction clutch. Likewise, Japanese Laid-Open Patent Application No. 62-18117 discloses an electromagnetic actuator arranged to directly control actuation of the friction clutch.
As an alternative, the torque transfer mechanism can employ an electric motor as the power-operated drive mechanism of the clutch actuator. For example, U.S. Pat. No. 5,323,871 discloses a clutch actuator having an electric motor that controls angular movement of a sector cam which, in turn, controls pivoted movement of a lever arm used to apply the clutch engagement force on the friction clutch. Likewise, Japanese Laid-Open Publication No. 63-66927 discloses a clutch actuator which uses an electric motor to rotate one cam plate of a ballramp operator mechanism for engaging the friction clutch. Finally, U.S. Pat. Nos. 4,895,236 and 5,423,235, respectively, disclose a clutch actuator with an electric motor driving a reduction gearset for controlling movement of a ballscrew operator mechanism and a ballramp operator mechanism. Finally, commonly owned U.S. Pat. No. 6,595,338 discloses an electrohydraulic clutch actuator for controlling engagement of a friction clutch.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed toward a clutch actuator that is operable to adaptively regulate engagement of a friction clutch assembly. The clutch actuator includes a power-operated drive mechanism and an operator mechanism. The operator mechanism generally includes a first actuator plate, a second actuator plate, a ballramp unit operably disposed between the first and second actuator plates, and a linear operator for controlling relative angular movement between the first and second actuator plates. Such angular movement causes the ballramp unit to move one of the first and second actuator plates axially for generating a clutch engagement force that is applied to the friction clutch assembly.
Pursuant to a preferred construction, the ballramp unit is integrated into the first and second actuator plates to provide a compact operator mechanism. In addition, the linear operator is disposed between first and second arm segments provided on the corresponding first and second actuator plates. The linear operator may be a dual piston assembly having first and second pistons disposed in a common pressure chamber. The first piston has a first roller engaging a first cam surface formed on the first arm segment of the first actuator plate while the second piston has a second roller engaging a second cam surface formed on the second arm segment of the second actuator plate.
In accordance with another feature, the operator mechanism associated with the clutch actuator of the present invention further includes an apply plate that is disposed adjacent to the second actuator plate and which is axially moveable therewith to apply the clutch engagement force to the friction clutch assembly. In yet another feature, the operator mechanism of the clutch actuator further includes a stop plate that is disposed adjacent to the first actuator plate and which inhibits axial movement of the first actuator plate.
The drive mechanism associated with the clutch actuator of the present invention is operable to control the fluid pressure within the pressure chamber, thereby controlling the position of the first and second pistons and the relative angular position of the first actuator plate relative to the second actuator plate. The drive mechanism includes an electric motor, a ballscrew unit, a gearset interconnecting a rotary output of the motor to a rotary component of the ballscrew unit, and a control piston disposed in a control chamber. The control piston is fixed to an axially moveable component of the ballscrew unit while a fluid delivery system provides fluid communication between the control chamber and the pressure chamber. In operation, the location of the axially moveable ballscrew component within the control chamber controls the fluid pressure within the pressure chamber.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the present invention will become apparent to those skilled in the art from analysis of the following written description, the appended claims, and accompanying drawings in which:
FIG. 1 illustrates an exemplary drivetrain in a four-wheel drive vehicle equipped with a power transfer system;
FIG. 2 is a sectional view of a torque transfer mechanism having a friction clutch assembly and a clutch actuator according to the present invention integrated in the power transfer system;
FIG. 3 is another view of the clutch actuator of the present invention;
FIG. 4 illustrates an alternative version of the clutch actuator shown in FIG. 3 ;
FIG. 5 is a schematic illustration of the torque transfer mechanism of the present invention arranged to provide drive torque to an axle assembly of a motor vehicle;
FIG. 6 is a schematic illustration of the torque transfer mechanism of the present invention arranged as a slip limiting and torque biasing differential in an axle assembly;
FIG. 7 is a schematic illustration of a pair of torque transfer mechanisms arranged as a torque vectoring axle assembly for a motor vehicle;
FIG. 8 illustrates another exemplary drivetrain equipped with a power transfer device to which the torque transfer mechanism of the present invention is applicable;
FIGS. 9 through 12 are schematic illustrations of various power transfer devices adapted for use with the drivetrain of FIG. 8 ;
FIG. 13 illustrates yet another exemplary drivetrain for a four-wheel drive vehicle; and
FIGS. 14 and 15 illustrate transfer cases equipped with the torque transfer mechanisms of the present invention and which are adapted for use with the drivetrain of FIG. 13 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to a torque transfer mechanism that can be adaptively controlled for modulating the torque transferred between a first rotary member and a second rotary member. The torque transfer mechanism finds particular application in power transfer systems of the type used in motor vehicle drivelines and which include, for example, transfer cases, power take-off units, limited slip drive axles and torque vectoring drive modules. Thus, while the present invention is hereinafter described in association with one or more particular arrangements for specific driveline applications, it will be understood that the arrangements shown and described are merely intended to illustrate embodiments of the present invention.
With particular reference to FIG. 1 , a schematic layout of a vehicle drivetrain 10 is shown to include a powertrain 12 , a first or primary driveline 14 driven by powertrain 12 , and a second or secondary driveline 16 . Powertrain 12 includes an engine 18 and a multi-speed transaxle 20 arranged to normally provide motive power (i.e., drive torque) to a pair of first wheels 22 associated with primary driveline 14 . Primary driveline 14 further includes a pair of axle shafts 24 connecting wheels 22 to a front differential unit 25 associated with transaxle 20 .
Secondary driveline 16 includes a power take-off unit (PTU) 26 driven by the output of transaxle 20 , a propshaft 28 driven by PTU 26 , a pair of axle shafts 30 connected to a pair of second wheels 32 , a rear differential unit 34 driving axle shafts 30 , and a power transfer device 36 that is operable to selectively transfer drive torque from propshaft 28 to rear differential unit 34 . Power transfer device 36 is shown integrated into a drive axle assembly and includes a torque transfer mechanism 38 . Torque transfer mechanism 38 functions to selectively transfer drive torque from propshaft 28 to differential unit 34 . More specifically, torque transfer mechanism 38 includes an input shaft 42 driven by propshaft 28 and a pinion shaft 44 that drives differential unit 34 .
Vehicle drivetrain 10 further includes a control system for regulating actuation of torque transfer mechanism 38 . The control system includes a clutch actuator 50 , vehicle sensors 52 , a mode select mechanism 54 and an electronic control unit (ECU) 56 . Vehicle sensors 52 are provided to detect specific dynamic and operational characteristics of drivetrain 10 while mode select mechanism 54 enables the vehicle operator to select one of a plurality of available drive modes. The drive modes may include a two-wheel drive mode, a locked (“part-time”) four-wheel drive mode, and an adaptive (“on-demand”) four-wheel drive mode. In this regard, torque transfer mechanism 38 can be selectively engaged for transferring drive torque from input shaft 42 to pinion shaft 44 to establish both of the part-time and on-demand four-wheel drive modes. ECU 56 controls actuation of clutch actuator 50 which, in turn, controls the drive torque transferred through torque transfer mechanism 38 .
Referring now to FIGS. 2 and 3 , a cross-section of torque transfer mechanism 38 is shown. Torque transfer mechanism 38 generally includes a friction clutch assembly 60 having a multi-plate clutch pack 62 . Clutch actuator 50 is operable to generate and apply a clutch engagement force on clutch pack 62 so as to regulate engagement and thus, the amount of drive torque transfer through clutch pack 62 . Friction clutch assembly 60 also includes a clutch hub 64 and a drum 66 . Hub 64 is adapted to be coupled for rotation with input shaft 42 while drum 66 is adapted to be coupled for rotation with pinion shaft 44 . As seen, a set of first or inner clutch plates 68 associated with clutch pack 62 are fixed for rotation with hub 64 . Likewise, a set of second clutch plates 70 are interleaved with first clutch plates 68 and are fixed for rotation with drum 66 .
The degree of engagement of clutch pack 62 , and therefore the amount of drive torque transferred therethrough, is largely based on the frictional interaction of clutch plates 68 and 70 . More specifically, with friction clutch assembly 60 in a disengaged state, interleaved clutch plates 68 and 70 slip relative to one another and little or no torque is transferred through clutch pack 62 . However, when friction clutch assembly 60 is in a fully engaged state, there is no relative slip between clutch plates 68 and 70 and 100% of the drive torque is transferred from input shaft 42 to pinion shaft 44 . In a partially engaged state, the degree of relative slip between interleaved clutch plates 68 and 70 varies and a corresponding amount of drive torque is transferred through clutch pack 62 .
In general, clutch actuator 50 includes an operator mechanism 72 and a power-operated drive mechanism 73 . Operator mechanism 72 is shown to include a first actuator plate 74 , a second actuator plate 76 , a stop plate 78 , an apply plate 80 , a ballramp unit 82 , and a piston assembly 84 . First and second actuator plates 74 and 76 are rotatably supported on hub 64 by a bearing assembly 86 and include corresponding arm segments 74 A and 76 A, respectively, that extend tangentially. More specifically, arms 74 A and 76 A include respective edges 87 and 89 that are generally parallel to the axis A.
First and second actuator plates 74 and 76 also include first and second ballramp groove sets 90 and 92 , respectively. Balls 94 are disposed between first and second actuator plates 74 and 76 and ride within ballramp groove sets 90 and 92 . As best seen from FIG. 3 , each set has three equally spaced grooves aligned circumferentially relative to the “A” axis. Thus, ballramp unit 82 is shown to be integrated into actuator plates 74 and 76 so as to provide a compact arrangement. Stop plate 78 is supported on hub 64 and is inhibited from axial movement by a lock ring 96 . More specifically, stop plate 78 is disposed between lock ring 96 and first actuator plate 74 and is separated from first actuator plate 74 by a thrust bearing assembly 98 . Apply plate 80 is disposed between clutch pack 62 and second actuator plate 76 and is separated from second actuator plate 76 by another thrust bearing assembly 100 . Apply plate 80 is adapted to move axially to regulate engagement of clutch pack 62 , as is explained in further detail below.
Piston assembly 84 is actuated by drive mechanism 73 to control relative rotation between first and second actuator plates 74 and 76 . More specifically, piston assembly 84 includes a first piston 104 and a second piston 106 that are disposed for sliding movement within a pressure chamber 108 formed in a cylinder housing 110 . As seen, first and second pistons 104 and 106 have first and second rollers 112 and 114 , respectively, attached thereto. First and second rollers 112 and 114 engage corresponding first and second cam surfaces 116 and 118 formed on first and second arms 74 A and 76 A, respectively. First and second rollers 112 and 114 are induced to ride against first and second cam surfaces 116 and 118 in response to movement of pistons 104 and 106 caused by actuation of drive mechanism 73 . Specifically, rolling movement of first and second rollers 112 and 114 against first and second cam surfaces 116 and 118 results in relative rotation between first and second actuator plates 74 and 76 . Pistons 104 and 106 are shown in FIG. 3 in a first or “retracted” position within pressure chamber 108 such that first and second actuator plates 74 and 76 are located in a corresponding first angular position relative to each other. A return spring 120 is provided for normally biasing first and second actuator plates 74 and 76 toward this first angular position. With the actuator plates located in their first angular position, ballramp unit 82 functions to axially locate second actuator plate 76 in a corresponding first or “released” position whereat apply plate 80 is released from engagement with clutch pack 62 . In this position, a minimum clutch engagement force is applied to clutch pack 62 such that little or no drive torque is transmitted from input shaft 42 to pinion shaft 44 .
As will be detailed, drive mechanism 73 is operable to cause pistons 104 and 106 to move toward a second or “expanded” position within pressure chamber 108 such that actuator plates 74 and 76 are caused by engagement with rollers 112 and 114 to circumferentially index to a second angular position. Such rotary indexing of actuator plates 74 and 76 causes ballramp unit 82 to axially displace second actuator plate 76 from its released position toward a second or “locked” position whereat apply plate 80 is fully engaged with clutch pack 62 . With second actuator plate 76 in its locked position, a maximum clutch engagement force is applied to clutch pack 62 such that pinion shaft 44 is, in effect, coupled for common rotation with input shaft 42 .
Drive mechanism 73 is shown in FIG. 3 to include a piston housing 122 , a ballscrew and piston assembly 124 , a gearset 126 , and an electric motor 128 . Electric motor 128 rotatably drives gearset 126 which, in turn, rotatably drives a leadscrew 130 associated with piston assembly 124 . Such rotation of leadscrew 130 results in axial movement of a nut 131 mounted thereon which, in turn, causes corresponding axial movement of a piston plunger 132 within a fluid control chamber 134 formed in housing 122 . Control chamber 134 is in fluid communication with pressure chamber 108 via a closed hydraulic control system. Specifically, as piston plunger 132 translates along an axis “B”, it regulates the volume of fluid in control chamber 134 . As the volume of control chamber 134 decreases, fluid is supplied through a conduit 136 to pressure chamber 108 in piston assembly 84 , thereby causing pistons 104 and 106 to move in concert toward their expanded position. In contrast, as the volume of control chamber 134 increases, the fluid flows back through conduit 136 from piston chamber 108 to relieve the pressure exerted by first and second rollers 112 and 114 against first and second cam surfaces 116 and 118 .
Accordingly, rotation of leadscrew 130 in a first rotary direction results in axial movement of piston plunger 132 in a first direction (right in FIG. 3 ), thereby causing pistons 104 and 106 to be forcibly moved toward their expanded position for angularly indexing first and second actuator plates 74 and 76 toward their second angular position in opposition to the biasing force exerted thereon by return spring 120 . In contrast, rotation of leadscrew 130 in a second rotary direction results in axial movement of piston plunger 132 in a second direction (left in FIG. 3 ), thereby permitting the biasing force of return spring 120 to forcibly rotate actuator plates 74 and 76 toward their first angular position which, in turn, causes pistons 104 and 106 to move back toward their retracted position. A pressure sensor 140 is responsive to the pressure within conduit 136 and generates a signal that is sent to ECU 56 . Preferably, ECU 56 is functional to correlate line pressure readings from pressure sensor 140 to the torque output of friction clutch assembly 60 .
In its neutral, clutch actuator 50 imparts no clutch engagement force on clutch pack 62 such that first and second clutch plates 68 and 70 are permitted to slip relative to one another. As first and second actuator plates 74 and 76 are caused to rotate relative to one another, balls 94 ride within ballramp grooves 90 and 92 to axially move second actuator plate 76 . Since stop plate 78 inhibits axial movement of first actuator plate 74 , as balls 94 ride up ballramp grooves 90 and 92 , second actuator plate 76 is separated from first actuator plate 74 and moves linearly to impart the clutch engagement force on apply plate 80 through thrust bearing assembly 100 . Apply plate 80 , in turn, imparts this linear clutch engagement force on clutch pack 62 , thereby regulating engagement of clutch pack 62 .
With second actuator plate 76 in its released position, virtually no drive torque is transferred from input shaft 42 to pinion shaft 44 through friction clutch 60 , thereby effectively establishing the two-wheel drive mode. In contrast, axial movement of second actuator plate 76 to its locked position causes a maximum amount of drive torque to be transferred through friction clutch 60 to pinion shaft 44 for, in effect, coupling pinion shaft 44 for common rotation with rear prop shaft 28 , thereby establishing the part-time four-wheel drive mode. Accordingly, controlling the position of second actuator plate 76 between its released and locked positions permits variable control of the amount of drive torque transferred from rear prop shaft 28 to pinion shaft 44 , thereby establishing the on-demand four-wheel drive mode. Thus, the control signal supplied to electric motor 128 controls the angular position of actuator plates 74 and 76 for controlling axial movement of apply plate 80 relative to clutch pack 62 .
ECU 56 sends electrical control signals to electric motor 128 for accurately controlling the position of control piston 132 within control chamber 134 by utilizing a predefined control strategy that is based on the mode signal from mode selector 54 and the sensor input signals from vehicle sensors 52 . In operation, if the two-wheel drive mode is selected, motor 156 drives leadscrew 130 in its second direction for moving control piston 132 so as to reduce the fluid pressure within pressure chamber 108 . As such, return spring 120 forcibly biases actuator plates 74 and 76 toward their first angular position until second actuator plate 76 is axially moved to its released position. In contrast, upon selection of the part-time four-wheel drive mode, motor 128 drives leadscrew 130 in its first rotary direction for increasing the fluid pressure in pressure chamber 108 until pistons 104 and 106 are located in their expanded position. As noted, such movement causes actuation plates 74 and 76 to rotate to their second angular position such that second actuator plate 76 is axially moved to its locked position for fully engaging friction clutch 60 .
When mode selector 54 indicates selection of the on-demand four-wheel drive mode, ECU 56 energizes motor 128 for initially rotating leadscrew 130 until second actuator plate 76 is located in an intermediate or “ready” position. Accordingly, a predetermined minimum amount of drive torque is delivered to pinion shaft 44 through friction clutch 60 in this adapt-ready condition. Thereafter, ECU 56 determines when and how much drive torque needs to be transferred to pinion shaft 44 based on the current tractive conditions and/or operating characteristics of the motor vehicle, as detected by sensors 52 . Sensors 52 detect such parameters as, for example, the rotary speed of the shafts, the vehicle speed and/or acceleration, the transmission gear, the on/off status of the brakes, the steering angle, the road conditions, etc. Such sensor signals are used by ECU 56 to determine a desired output torque value utilizing a control scheme that is incorporated into ECU 56 . This desired torque value is used to actively control actuation of electric motor.
In addition to adaptive torque control, the present invention permits release of friction clutch 60 in the event of an ABS braking condition or during the occurrence of an over-temperature condition. Furthermore, while the control scheme was described based on an on-demand strategy, it is contemplated that a differential or “mimic” control strategy could likewise be used. Specifically, the torque distribution between prop shaft 28 and pinion shaft 44 can be controlled to maintain a predetermined rear/front ratio (i.e., 70:30, 50:50, etc.) so as to simulate the inter-axle torque splitting feature typically provided by a mechanical center differential unit. Regardless of the control strategy used, accurate control of clutch actuator 50 will result in the desired torque transfer characteristics across friction clutch 60 . Furthermore, it should be understood that mode select mechanism 54 could also be arranged to permit selection of only two different drive modes, namely the on-demand 4WD mode and the part-time 4WD mode. Alternatively, mode select mechanism 54 could be eliminated such that the on-demand 4WD mode is always operating in a manner that is transparent to the vehicle operator.
Referring to FIG. 4 , clutch actuator 50 is now shown to include a modified operator mechanism 72 ′ wherein first actuator plate 74 is held against angular movement such that only second actuator plate 76 is rotated relative to first actuator plate 74 . In this regard, anti-rotation members 150 and 152 are located on opposite sides of arm segment 74 A so as to prevent bi-directional rotation of first actuator plate 74 . In addition, grooves 90 on first actuator plate 74 have been removed to permit balls 94 to ride on a planar face cam surface on first actuator plate 74 . Also, piston assembly 84 ′ now only includes piston 106 ′ which is still retained for sliding movement within pressure chamber 108 such that roller 114 rides against cam surface 118 on arm segment 76 A of second actuator plate 76 . As before, drive mechanism 73 functions to control the position of piston 106 ′ so as to control the rotated position of second actuator plate 76 relative to first actuator plate 74 . In particular, piston 106 ′ is moveable between retracted and expanded positions to cause corresponding angular movement of second actuator plate between its first and second angular positions. When second actuator plate 76 is in its first angular position, ballramp unit 82 ′ causes second actuator plate 76 to also be axially located in its released position. In contrast, rotation of second actuator plate 76 to its second angular position causes ballramp unit 82 ′ to axially move second actuation plate 76 to its locked position.
It is contemplated that alternative drive mechanisms can be used in place of the closed-circuit hydraulic system disclosed. For example, a motor-driven leadscrew could be implemented to drive one or both of first and second pistons 104 and 106 of operator mechanism 72 between their retracted and expanded positions. Likewise, it is to be understood that the particular drivetrain application shown is merely exemplary of but one application to which the clutch actuator of the present invention is well suited.
FIG. 5 is provided to show incorporation of friction clutch 60 and clutch actuator 50 associated with torque transfer mechanism 38 in power transfer device 36 . As seen, pinion shaft 44 drives a pinion 160 that is meshed with a ring gear 162 fixed to a carrier 164 of differential unit 34 . Carrier 164 rotatably supports and drives a pair of pinion gears 166 that each mesh with a pair of side gears 168 . Each side gear 168 is fixed for rotation with a corresponding one of axleshafts 30 . The arrangement shown for the drive axle assembly of FIG. 5 is operable to provide on-demand four-wheel drive by adaptively controlling the transfer of drive torque from the primary driveline to the secondary driveline. In contrast, a drive axle assembly 170 is shown in FIG. 6 wherein a torque transfer mechanism, hereinafter referred to as torque coupling 38 A, is now operably installed between differential case 164 and one of axleshafts 30 to provide an adaptive “side-to-side” torque biasing and slip limiting feature. Torque coupling 38 A is schematically shown to again include friction clutch 60 and clutch actuator 50 , the construction and function of which are understood to be similar to the detailed description previously provided herein for each sub-assembly. As see, drum 66 is shown to be driven by carrier 164 while hub 64 is driven by one of axleshafts 30 .
Referring now to FIG. 7 , the power transfer device is shown as having a pair of torque couplings 38 L and 38 R that are operably installed between propshaft 28 or pinion shaft 44 and axleshafts 30 . The driven shaft drives a right-angled gearset including pinion 160 and ring gear 162 which, in turn, drives a transfer shaft 174 . First torque coupling 38 L is shown disposed between transfer shaft 174 and the left one of axleshafts 30 L while second torque coupling 38 R is disposed between transfer shaft 174 and the right axleshaft 30 R. Each torque coupling includes a corresponding friction clutch 60 L and 60 R and clutch actuator 50 L and 50 R. Accordingly, independent torque transfer and slip control is provided between the driven shaft and each of rear wheels 32 L and 32 R pursuant to this arrangement.
To illustrate additional alternative power transfer systems to which the present invention is applicable, FIG. 8 schematically depicts a front-wheel based four-wheel drive drivetrain layout 10 ′ for a motor vehicle. In particular, engine 18 drives multi-speed transaxle 20 which has front differential unit 25 for driving front wheels 22 via first axleshafts 24 . As before, PTU 26 is driven by transaxle 20 . However, in this arrangement, a power transfer device 176 functions to transfer drive torque to propshaft 28 . Power transfer device 176 includes a torque coupling 180 having an output member coupled to propshaft 28 which, in turn, drives rear wheels 32 via rear axleshafts 34 . The rear axle assembly can be a traditional driven axle with a differential or, in the alternative, be similar to the drive axle arrangements described in regard to FIGS. 6 or 7 . Accordingly, in response to detection of certain vehicle characteristics by sensors 52 (i.e., the occurrence of a front wheel slip condition), the power transfer system causes torque coupling 180 to deliver drive torque “on-demand” to rear wheels 32 . It is contemplated that torque coupling 180 would be generally similar in structure and function to that of torque transfer coupling 38 previously described herein
Referring now to FIG. 9 , torque coupling 180 is schematically illustrated in association with an on-demand four-wheel drive system based on a front-wheel drive vehicle similar to that shown in FIG. 8 . In particular, an output shaft 182 of transaxle 20 is shown to drive an output gear 184 which, in turn, drives an input gear 186 that is fixed to a carrier 188 associated with front differential unit 25 . To provide drive torque to front wheels 22 , front differential unit 25 includes a pair of side gears 190 that are connected to front wheels 22 via axleshafts 24 . Differential unit 25 also includes pinions 192 that are rotatably supported on pinion shafts fixed to carrier 188 and which are meshed with side gears 190 . A transfer shaft 194 is provided for transferring drive torque from carrier 188 to a clutch hub 64 associated with friction clutch 60 . PTU 26 is a right-angled drive mechanism including a ring gear 196 fixed for rotation with drum 66 of friction clutch 60 and which is meshed with a pinion gear 198 fixed for rotation with propshaft 28 . According to the present invention, the components schematically shown for torque transfer coupling 180 are understood to be similar to those previously described. In particular, clutch actuator 50 includes a power-operated drive mechanism 73 that controls operation of an operator mechanism 72 or 72 ′ to adaptively control the clutch engagement force applied to clutch pack 62 . As such, drive torque is adaptively transferred on-demand from the primary (i.e., front) driveline to the secondary (i.e., rear) driveline.
Referring to FIG. 10 , a modified version of the power transfer device shown in FIG. 9 is now shown to include a second torque coupling 180 A that is arranged to provide a limited slip feature in association with primary differential 25 . As before, adaptive control of torque coupling 180 provides on-demand transfer of drive torque from the primary driveline to the secondary driveline. In addition, adaptive control of second torque coupling 180 provides adaptive torque biasing (side-to-side) between axleshafts 24 of primary driveline 14 . As seen, components of torque coupling 180 A that are common to those of torque coupling 180 are identified with an “A” suffix.
FIG. 11 illustrates another modified version of FIG. 9 wherein an on-demand four-wheel drive system is shown based on a rear-wheel drive motor vehicle that is arranged to normally deliver drive torque to rear wheels 32 while selectively transmitting drive torque to front wheels 22 through torque coupling 180 . In this arrangement, drive torque is transmitted directly from transmission output shaft 182 to power transfer unit 26 via a drive shaft 200 which interconnects input gear 186 to ring gear 196 . To provide drive torque to front wheels 22 , torque coupling 180 is shown operably disposed between drive shaft 200 and transfer shaft 194 . In particular, friction clutch 60 is arranged such that drum 66 is driven with ring gear 196 by drive shaft 200 . As such, clutch actuator 50 functions to transfer drive torque from drum 66 through clutch pack 62 to hub 64 which, in turn, drives carrier 188 of differential unit 25 via transfer shaft 194 .
In addition to the on-demand four-wheel drive systems shown previously, the power transmission technology of the present invention can likewise be used in full-time four-wheel drive systems to adaptively bias the torque distribution transmitted by a center or “interaxle” differential unit to the front and rear drivelines. For example, FIG. 12 schematically illustrates a full-time four-wheel drive system which is generally similar to the on-demand four-wheel drive system shown in FIG. 11 with the exception that an interaxle differential unit 210 is now operably installed between carrier 188 of front differential unit 25 and transfer shaft 194 . In particular, output gear 186 is fixed for rotation with a carrier 212 of interaxle differential 210 from which pinion gears 214 are rotatably supported. A first side gear 216 is meshed with pinion gears 214 and is fixed for rotation with drive shaft 200 so as to be drivingly interconnected to the rear driveline through power transfer unit 26 . Likewise, a second side gear 218 is meshed with pinion gears 214 and is fixed for rotation with carrier 188 of front differential unit 25 so as to be drivingly interconnected to the front driveline. Torque coupling 180 is now shown to be operably disposed between side gears 216 and 218 . Torque coupling 180 is operably arranged between the driven outputs of interaxle differential 210 for providing an adaptive torque biasing and slip limiting function between the front and rear drivelines.
Referring now to FIG. 13 , a drivetrain layout for a four-wheel drive vehicle is shown to include a power transfer device, hereinafter referred to as a transfer case 240 , arranged to transfer drive torque from engine 18 and transmission 20 to rear propshaft 28 and a front propshaft 242 that is arranged to drive front wheels 22 in via front differential 25 and axleshafts 24 . Transfer case 240 is shown to include a rear output shaft 244 coupled to rear propshaft 28 and a front output shaft 246 coupled to front propshaft 242 . From FIG. 14 , transfer case 240 is further shown to include an input shaft 248 driven by transmission 20 , a transfer unit 250 driving front output shaft 246 , and a differential 252 interconnecting input shaft 248 to transfer unit 250 and rear output shaft 244 . Transfer unit 250 includes a first sprocket 254 rotatably supported on rear output shaft 244 , a second sprocket 256 fixed to front output shaft 246 and a power chain 258 therebetween. Differential 252 includes an input 260 driven by input shaft 248 , a front output 262 driving first sprocket 254 , a second output 264 driving rear output shaft 244 , and a speed differentiating gearset therebetween. As seen, torque coupling 180 is operably disposed between transfer unit 250 and rear output shaft 244 to control adaptive torque biasing therebetween. FIG. 15 illustrates a modified version of transfer case 240 wherein differential 252 is removed such that input shaft 248 is directly coupled to rear output shaft 244 with friction clutch 60 arranged to permit on-demand transfer of drive torque from rear output shaft 244 to front output shaft 246 .
Various preferred embodiments have been disclosed to provide those skilled in the art an understanding of the best mode currently contemplated for the operation and construction of the present invention. The invention being thus described, it will be obvious that various modifications can be made without departing from the true spirit and scope of the invention, and all such modifications as would be considered by those skilled in the art are intended to be included within the scope of the following claims.
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A clutch actuator for controlling engagement of a friction clutch and having a first actuator plate rotatable about an axis, a second actuator plate adjacent to the first actuator plate, and a ballramp unit disposed between the first and second actuator plates. A piston assembly acts to induce rotation of the first actuator plate relative to the second actuator plate. Relative rotation between the first actuator plate and the second actuator plate induces linear movement of one of the first and second actuator plates along the axis to regulate engagement of the friction clutch.
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FIELD OF THE INVENTION
[0001] This invention relates to methods for synthesis of biologically active di- and tri-saccharides comprising α-D-Gal(1→3)-D-Gal. In particular the invention provides novel reagents, intermediates and processes for the solution or solid phase synthesis of α-D-galactopyranosyl-(1→3)-D-galactose, and derivatives thereof.
BACKGROUND OF THE INVENTION
[0002] The advent of methods for successful organ transplantation has led to an increasing shortage of donor organs suitable for clinical application. Immuno-concordant species such as non-human primates are potentially a source of allografts which would provide the lowest immunological barrier, but limited availability and ethical concerns, as well as the risk presented by primate retroviruses, mean that this source does not provide a long term solution. Xenografts from discordant but more readily available species, such as pigs, are usually rejected almost immediately. This phenomenon is known as hyperacute rejection (HAR). Thus the suppression of xenoreactive natural antibodies is a key procedure in the implementation of successful xenotransplantation (Tong, Z. et al, 1998). It has been reported that ligands comprising the non-reducing terminal oligosaccharides Galα(1-43)Gal and Galα(1→3)Galβ(1→4)GlcNAc showed the highest affinity with human anti-porcine antibodies (Good, H. et al. 1992). Of the various means proposed for overcoming HAR, the simplest in concept are the competitive blocking of Galα(1→3)Gal antibodies in vivo, or the extracorporeal removal of these antibodies from the circulation (Simon, P. M., 1996). Both methods require the ready availability of the disaccharide or trisaccharide.
[0003] In addition to this problem, intestinal infection by Clostridium difficile is one of the most common causes of diarrhoea in hospital patients, especially in the elderly (Boriello, S. P., 1990). C. difficile has been found to be an aetiological agent of antibiotic-associated diarrhoea and pseudomembranous colitis (Smith, J. A. et al., 1997). C. difficile produces two toxins, toxin A and toxin B. Of these, toxin A was shown in animal studies to be an enterotoxin that elicits increased intestinal permeability, fluid secretion and inflammation, and causes severe disruption of the intestinal epithelium (Burakoff, R. et al, 1995; Castex, F. et al, 1994; Eglow, R. et al., 1992; Torres, J. et al, 1990). In model animal systems, the carbohydrate moiety to which toxin A binds has been shown to terminate in the trisaccharide sequence Galα(1→3)Galβ(1→4)GlcNAc (Krivan, H. C. et al, 1986).
[0004] Although the chemistry and biochemistry of oligosaccharide compounds has been extensively studied, there are still difficulties associated with their synthesis and purification. Consequently there is a need in, the art for improved methods of synthesis and purification of these compounds.
[0005] Apart from the design of effective building blocks, one of the most difficult steps in the synthesis of Galα(1→43)Gal, Galα(1→3)Galβ(1→4)GlcNAc and related compounds is the formation of the α(1→3) linkage. Although a number of synthetic routes have been described, all of these methods are complex, time-consuming, and costly, and are unsuited to large-scale synthesis.
[0006] Chacon-Fuertes provided a procedure for the synthesis of 3-O-α-D-galactopyranosyl-D-galactose [i]
[0007] which required a mercuric cyanide-catalysed glycosylation for formation of the α(143) glycosidic linkage (Chacon-Fuertes M. E. and Martin-Lomas, M., 1975). The synthesis was protracted, required chromatography, and used dangerous reagents. Lemieux described the chemical synthesis of 3-O-α-D-galactopyranosyl-D-galactose using a per-O-benzylated α-D-galactopyranosyl bromide sugar donor and a 2,2,2-trichloroethyl 2,4,6-tri-O-acetyl-β-D-galactopyranoside acceptor (Lemieux, R. U. and Driguez, H., 1975). Lemieux employed tetraethyl ammonium bromide as a promoter in a reaction that after chromatography gave 35% yield of product. 1 H NMR spectroscopy indicated that the glycosylation product still contained substantial impurities. After deprotection with zinc/acetic acid and preparative thin layer chromatography, de-O-acetylation, hydrogenolysis and paper chromatography, an authentic sample of 3-O-α-D-galactopyranosyl-D-galactose was finally achieved.
[0008] An alternative approach used an allyl 2-O-benzoyl-4,6-O-benzylidene-β-D-galactopyranoside acceptor and an acetimidate sugar donor (Sinay, P. and Jacquinet, J. C., 1979). The formation of the α(1→43) linkage was effected with toluene sulphonic acid in nitromethane in good yield, but chromatography was required for purification. Although generally maintaining yields of greater than 90% for the remainder of the synthesis to the target 3-O-α-D-galactopyranosyl-D-galactose, chromatography was required at most steps. Similarly a benzylated Gal(α1-3)Gal disaccharide was synthesised using an α-D-galactopyranosyl bromide donor, but employing stannylene chemistry to selectively activate the 3-O-position of the acceptor galactoside, (Augé, C. and Veyrières, A., J. C. S., 1979). The benzylated Galα(1→3)Gal disaccharide subsequently underwent hydrogenolysis to afford 3-O-α-D-galactopyranosyl-D-galactose. The reported yields were very low, and most steps required chromatography.
[0009] Another synthesis of the 3-O-α-D-galactosyl-D-galactose disaccharide employed a benzyl 2,4,6-tri-O-benzyl-β-D-galactopyranoside acceptor and a fully-benzylated imidate galactosyl donor (Milat, M-L. et al, 1982). The free disaccharide was eventually obtained after a final hydrogenolysis, and although reasonable yields were achieved, chromatography was unavoidable at many stages of the synthesis. Takeo employed a galactosyl bromide donor and tetraethylammonium bromide as a promoter, and synthesised the disaccharide of interest in a protected form in 40% yield after chromatography. Hydrogenolysis then yielded 3-O-α-D-galactopyranosyl-D-galactose (Takeo, K. and Maeda, H., 1988). A chemo-enzymatic synthesis utilised α-D-galactosidase from coffee beans to form the disaccharide, in unreported yield. p-Nitrophenyl-α-D-galactopyranoside was used as both the acceptor and donor. The resultant disaccharide derivative was then modified and chromatographed to afford 3-O-α-D-galactopyranosyl-D-galactose (Matsuo, I. et al, 1997).
[0010] It is desirable to avoid the use of toxic reagents, and in order to reduce costs it is also highly desirable to minimise the number of purification steps. If possible, it is particularly desirable to minimize the number of chromatographic purification steps, or even to avoid entirely the need for chromatographic purification, because this technique is time-consuming and costly.
[0011] Synthesis of the trisaccharide α-D-galactopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-N-acetyl-D-glucosamine (ii) has understandably been even more difficult than that of α-D-galactopyranosyl-(1→3)-D-galactose.
[0012] There have been no methods reported in the literature for the synthesis of (ii) using chemical means, although closely analogous compounds have been developed for in vitro and in vivo applications (Garegg, P. J. and Oscarson, S., 1985; Schaubach, R. et al, 1991). There have been some reports of enzymatic synthesis of oligosaccharide (ii) and derivatives thereof. Nilsson synthesised the 2-N-trichloroethoxycarbonyl protected ethyl thioglycoside of (ii) by enzymatic methods, using an α-D-galactosidase to effect the formation of the α(1→43) glycosidic linkage followed by β-D-galactosidase treatment (Nilsson, K. G. I., 1997). Similarly galactosidases have been used for the synthesis of target compound (ii), employing similar methodologies (Matsuo, I. et al, 1997). Another ethyl thioglycoside derivative of (ii) was synthesised using a and β galactosidases (Vic, G. et al, 1997). Analogues of (ii) similar to those described above with lipophilic tails attached via the glycosidic linkage were synthesised using α(1→3) galactosyltransferases (Sujino, K. et al., 1998).
[0013] All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.
[0014] We have now found that novel thioacyl-substituted glycosides of 3-O-α-D-galactopyranosyl-D-galactose can be used for glycoconjugate synthesis by chemical methods. These derivatives can be linked to a suitable soluble support, such as polyethylene glycol. These compounds can be used for removal of anti-Gal antibodies from a transplant recipient's blood prior to xenotransplantation, or as anti-bacterial agents to combat bacteria such as C. difficile.
SUMMARY OF THE INVENTION
[0015] In a first aspect the invention provides a protected glucosamine compound of general formula I:
[0016] in which R 1 is H or acetyl and R 2 is benzyl or 4-chlorobenzoyl,
[0017] with the proviso that when R 2 is benzyl, R 1 is not acetyl.
[0018] In a second aspect, the invention provides a protected monosaccharide building block of general formula II:
[0019] in which R 3 is H, methoxy or methyl, and in which
[0020] (a) when R 3 is methoxy or methyl, R 1 is H, benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-II methylenedioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl; and
[0021] R 2 is H, Fmoc, benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl;
[0022] (b) when R 3 is H, R 1 is benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, benzyl, 3,4-methylene-dioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl, and
[0023] R 2 is Fmoc, benzoyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl,
[0024] with the provisos that
[0025] (i) when R 1 is acetyl, R 2 is not chloroacetyl or acetyl, and vice versa;
[0026] (ii) when R 2 is levulinoyl, R 1 is not benzoyl, and vice versa; and
[0027] (iii) when R 1 is benzoyl, R 2 is not benzoyl, and vice versa.
[0028] When R 2 is Fmoc, R 1 is benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-methylene-dioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl.
[0029] Preferably the compound is of general formula III:
[0030] in which R 1 is pivaloyl, benzoyl, 4-chlorobenzoyl, 4-methoxybenzyl, or 3,4-methylenedioxybenzyl, and
[0031] R 2 is H, Fmoc, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methoxybenzyl, or 3,4-methylenedioxybenzyl, with the proviso that if R 1 is benzoyl, R 2 is not levulinoyl.
[0032] In preferred embodiments, the compound is
[0033] (a) a galactopyranoside of general formula III, in which R 1 is 4-chlorobenzoyl, pivaloyl or acetyl, and R 2 is Fmoc or H;
[0034] (b) a compound of general formula III in which R 1 is 4-chlorobenzoyl and R 2 is chloroacetyl; or
[0035] (c) a compound of general formula III in which both R 1 and R 2 are 3,4-methylenedioxybenzyl.
[0036] In a third aspect, the invention provides a galactopyranoside compound of general formula IV:
[0037] in which each R 1 is independently 4-chlorobenzyl, 4-azidobenzyl, 4-N-acetamidobenzyl, 4-methylbenzyl, 3,4-methylenedimethoxybenzyl, or 2-nitrobenzyl.
[0038] Preferably each R 1 is 4-chlorobenzyl.
[0039] In a fourth aspect the invention provides a polyethyleneglycol (PEG)-linked monosaccharide of general formula V:
[0040] in which n is an integer from 1-5;
[0041] R 1 is a linking group or a group suitable for the formation of a covalent linkage, and includes but is not limited to groups such as halogen, azido, carboxylic acid, thiol, hydroxyl, thioester, xanthate, amido, or dithiocarbamate; R 2 is acetyl, 4-chlorobenzoyl, levulinoyl, pivaloyl, chloroacetate, benzoyl, or 4-methybenzoyl;
[0042] R 3 is H, Fmoc, benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, or 4-azidobenzyl; and
[0043] R 4 is methoxy, H, or methyl.
[0044] Preferably n is 2, R 1 is thiobenzoate or thiobiphenylcarbonyl, R 2 is 4-chlorobenzoyl, R 3 is H, and R 4 is H.
[0045] In a fifth aspect the invention provides a compound of general formula VI:
[0046] in which R 7 is H, methoxy or methyl;
[0047] R 1 is aryl, substituted aryl, benzyl, substituted benzyl, alkyl, substituted alkyl, PEG, or substituted PEG;
[0048] R 2 is acetamido or amino;
[0049] R 3 and R 4 are independently benzyl, substituted benzyl, silylether or acyl;
[0050] R 5 is 4-chlorobenzoyl, benzoyl, pivaloyl, acetyl, levulinoyl or 4-methylbenzoyl; and
[0051] R 6 is a substituted or unsubstituted pyranosyl or furanosyl sugar, H, Fmoc, acetyl, chloroacetyl, levulinoyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, or 4-azidobenzyl.
[0052] When the anomeric configuration of the glucosamine moiety of general formula VI is α and R 3 is benzyl and R 4 is benzoyl and R 7 is H, then R 2 may be acetamido, amino, N-phthalimido, R 5 may be 4-chlorobenzoyl, benzoyl, pivaloyl, acetyl, levulinoyl or 4-methylbenzoyl, and R 6 is a substituted or unsubstituted pyranosyl or furanosyl sugar, H, Fmoc, acetyl, chloroacetyl, levulinoyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, or 4-azidobenzyl.
[0053] When the anomeric configuration of the glucosamine moiety of general formula VI is β and R 1 is benzyl and R 7 is H, then R 2 is acetamido, amino, or N-phthalimido; R 3 and R 4 are independently benzyl, substituted benzyl, silylether or acyl; R 5 is 4-chlorobenzoyl, benzoyl, pivaloyl, acetyl, levulinoyl or 4-methylbenzoyl, and R 6 is a substituted or unsubstituted pyranosyl or furanosyl sugar, H, Fmoc, acetyl, chloroacetyl, levulinoyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, or 4-azidobenzyl.
[0054] When the anomeric configuration of the glucosamine moiety of general formula VI is α and R 1 , R 3 , and R 4 are benzyl or substituted benzyl and R 7 is H, then R 2 is acetamido, amino, or N-phthalimido, R 5 is pivaloyl, 4-chlorobenzoyl, benzoyl, or levulinoyl, and R 6 is a substituted or unsubstituted pyranosyl or furanosyl sugar, H, Fmoc, acetyl, chloroacetyl, levulinoyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, or 4-azidobenzyl, with the proviso that when R 3 and R 4 are benzyl, R 5 is not acetyl or benzoyl.
[0055] In preferred embodiments:
[0056] (a) the anomeric configuration of the glucosamine moiety of general formula VI is β, R 1 is benzyl, R 2 is amino or acetamido, R 3 and R 4 are benzyl, R 5 is 4-chlorobenzoyl, pivaloyl or acetyl, R 6 is Fmoc or H, and R 7 is H;
[0057] (b) the anomeric configuration of the glucosamine moiety of general formula VI is α, R 1 is benzyl, R 2 is acetamido, R 3 is benzyl, R 4 is benzoyl or benzyl, R 5 is 4-chlorobenzoyl, R 6 is H or 4-chloroacetyl and R 7 is H;
[0058] (c) the compound is a trisaccharide of General Formula VII:
[0059] in which R is H or acetyl; R 1 is hydrogen, benzyl, benzoyl or p-chlorobenzoyl; and R 2 is hydrogen, 4-chloro-benzoyl, acetyl, benzoyl or pivaloyl;
[0060] (d) the compound is a trisaccharide of general formula VII, in which the anomeric configuration of the reducing end is a, R is acetyl, R 1 is benzoyl, 4-chlorobenzoyl or H, and R 2 is 4-chlorobenzoyl or H; or
[0061] (e) the compound is a trisaccharide of general formula VII, in which the anomeric configuration of the reducing sugar is β, R is acetyl or H, R 1 is benzyl, and R 2 is H, 4-chlorobenzoyl, pivaloyl or acetyl.
[0062] In a sixth aspect the invention provides a compound of general formula VIII:
[0063] in which R 5 , R 6 and R 7 are independently H, 4-chlorobenzyl, 4-methoxybenzyl, 4-methylbenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl;
[0064] X is O, S, or N;
[0065] R 1 is alkyl, substituted alkyl, aryl, substituted aryl, PEG or substituted PEG;
[0066] R 2 is levulinoyl, 4-chlorobenzoyl, benzoyl, 4-methylbenzoyl, acetyl or pivaloyl; and
[0067] R 3 and R 4 may combine to form a benzylidene ring, which may optionally be substituted at the 4 position by methyl or methoxy; alternatively R 3 and R 4 may independently be H, benzyl or substituted benzyl.
[0068] When R 5 is 4-chlorobenzyl, 4-methoxybenzyl, 4-methylbenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl, and R 6 and R 7 combine to form a benzylidene or substituted benzylidene ring, then X is O, S, or N, R 1 is alkyl, substituted alkyl, aryl, substituted aryl, PEG, substituted PEG, acyl or substituted acyl, and R 2 is levulinoyl, 4-chlorobenzoyl, benzoyl, 4-methylbenzoyl, acetyl or pivaloyl.
[0069] When X is oxygen and R 1 is 3,4-methylenedioxybenzyl, then R 2 is H, 4-chlorobenzoyl, pivaloyl, acetyl, levulinoyl, benzoyl or chloroacetyl, R 3 and R 4 may combine to become a benzylidene ring or may independently be H, benzyl or substituted benzyl, and R 5 , R 6 and R 7 may be H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl.
[0070] When X is oxygen and R 1 is 2-[2-(2-thiobenzoyl)-ethoxy)ethyl or 2-[2-(2-thiobiphenylcabonyl)ethoxy], then R 2 is H, 4-chlorobenzoyl, pivaloyl, acetyl, levulinoyl, benzoyl or chloroacetyl, R 3 and R 4 may combine to form a benzylidene ring or may independently be H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl, R 5 is H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl, and R 6 and R 7 may combine to become a benzylidene ring or may independently be H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl.
[0071] When X is sulphur, R 1 is alkyl, substituted alkyl, aryl or substituted aryl, R 3 and R 4 combine to form a benzylidene ring and R 5 , R 6 and R 7 are benzyl, then R 2 is levulinoyl, 4-chlorobenzoyl, benzoyl, acetyl or pivaloyl, with the proviso that when R 1 is phenyl, R 2 is not levulinoyl.
[0072] Preferably either
[0073] (a) X is oxygen, R 1 is 2-[2-(2-thiobenzoyl)ethoxy)ethyl or 2-[2-(2-thiobiphenylcabonyl)ethoxy], R 2 is H or 4-chlorobenzoyl, R 3 and R 4 are H or combine to form a benzylidene ring, R 5 is H or 3,4-methylenedioxybenzyl, and R 6 and R 7 are both H or combine to form a benzylidene ring;
[0074] (b) X is S, R 1 is methyl, R 2 is 4-chlorobenzoyl, R 3 and R 4 combine to form a benzylidene ring, and R 5 , RE and R 7 are each 4-chlorobenzyl; or
[0075] (c) X is oxygen, R 1 is 3,4-methylenedioxybenzyl, R 2 is 4-chlorobenzoyl or H, R 3 and R 4 combine to form a benzylidene ring or are both H, and R 5 , RE and R 7 are independently 4-chlorobenzyl or H.
[0076] In a seventh aspect the invention provides a compound of general formula IX:
[0077] in which R 1 is 4-chlorobenzoyl, pivaloyl, acetyl, levulinoyl, benzoyl or chloroacetyl;
[0078] R 2 is H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl, 3,4-methylenedioxybenzyl, Fmoc, levulinoyl, acetyl or chloroacetyl; and
[0079] R 3 and R 4 may combine to form a benzylidene ring, or may independently be H, benzyl, 4-chlorobenzyl, 4-methoxybenzyl, 4-acetamidobenzyl, azidobenzyl or 3,4-methylenedioxybenzyl.
[0080] Preferably R 1 is 4-chlorobenzoyl, R 2 is H, and R 3 and R 4 combine to form a benzylidene ring.
[0081] In an eighth aspect the invention provides a polyethyleneglycol(PEG)-linked disaccharide of General Formula X or a trisaccharide of General Formula XI:
[0082] in which R is hydrogen or acyl, and n is an integer of from 1 to 3.
[0083] Preferably the compound of General Formula 2-[2-(2-thiobiphenylcarbonyl)ethoxy]-ethyl 3-O-(α-D-galactopyranosyl)-α-galactopyo de.
[0084] In a ninth aspect, the XI ion provides Galα(1→3)Galβ(1→44)GlcNAc coupled to a solid support to give a compound of general formula XII:
[0085] in which X is a solid support such as Sepharose or silica gel, and n is an integer of from 3 to 6.
[0086] The compounds of the first seven aspects of the invention are useful as intermediates in the synthesis of di- and trisaccharides. Accordingly, in a tenth aspect, the invention provides a method of synthesis of a desired compound of General Formula X to General Formula XII, or of α-D-galactopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-N-acetyl-D-glucosamine (Galα(1→43)Galβ(1→4)GlcNAc), α-D-galactopyranosyl-(1→3)-β-D-galactopyranose (Galα(1→43)Gal), or β-D-galactopyranosyl-(1→4)—N-acetyl-D-glucosamine (Galβ(1→4)GlcNAc), comprising the step of using a compound of General Formula I to IX as an intermediate.
[0087] Preferably when the desired compound is of general Formula X or XI the intermediate compound is of General Formula V. It will be clearly understood that although a compound of General Formula VI may be synthesised using a compound of General Formula I as an intermediate, alternative syntheses are available.
[0088] For the purposes of this specification, the term “alkyl” is intended to include saturated, unsaturated and cyclic hydrocarbon groups, and combinations of such groups. Suitable substituents on hydrocarbon chains or aryl rings include Br, Cl, F, I, CF 3 , NH 2 , substituted amino groups such as NHacyl, hydroxy, carboxy, C 1-6 alkylamino and C 1-6 alkoxy groups such as methoxy, and are preferably F, Cl, hydroxy, C 1-6 alkoxy, amino, C 1-6 alkylamino or C 1-6 carboxy.
[0089] In a eleventh aspect, the invention provides a method of preventing or reducing a hyperacute rejection response associated with xenotransplantation, comprising the step of administering an effective dose of thioalkyl Galα-(1→3)Gal or thioalkyl Galα(1→3)Galβ(1→4)GlcNAc to a subject in need of such treatment.
[0090] The compound may be administered before, during or after xenotransplantation.
[0091] In a twelfth aspect, the invention provides a method of preventing or reducing hyperacute rejection associated with xenotransplantation, comprising the steps of
[0092] a) removing plasma from a patient who is to undergo xenotransplantation;
[0093] b) exposing the plasma to thioalkyl Galα(1→3)Gal or thioalkyl-Galα(1→3)Galβ(1→4)GlcNAc linked to a solid support, and
[0094] c) reinfusing the thus-treated plasma into the patient.
[0095] In a thirteenth aspect, the invention provides a method of depleting anti-Galα(1→3)Gal antibodies from a plasma or serum sample, comprising the step of exposing the plasma or serum to thioalkyl Galα(1→3)Gal or thioalkyl Galα(1→3)Galβ(1→4)GlcNAc linked to a soluble support.
[0096] In a fourteenth aspect, the invention provides a method of treatment of C. difficile infection, comprising the step of administering an effective amount of α-D-galactopyranosyl-(1→3)-β-D-galacto-pyranosyl-(1→4)-N-acetyl-D-glucosamine (Galα(1→3)Galβ(1→4)GlcNAc) or of thioalkyl Galα(1→3)Galβ(1→4)GlcNAc, preferably linked to a soluble support, to a subject in need of such treatment.
[0097] Preferably the soluble support is a multidentate ligand or a dendrimer compound. Suitable dendrimers are disclosed for example in International patent application No. PCT/AU95/00350 (WO95/34595) by Biomolecular Research Institute Ltd.
[0098] In the eleventh to the fourteenth aspects of the invention, the subject may be a human, or may be a domestic, companion or zoo animal. While it is particularly contemplated that the compounds of the invention are suitable for use in medical treatment of humans, they are also applicable to veterinary treatment, including treatment of companion animals such as dogs and cats, and domestic animals such as horses, cattle and sheep, or zoo animals such as felids, canids, bovids, and ungulates.
[0099] Methods and pharmaceutical carriers for preparation of pharmaceutical compositions are well-known in the art, as set out in textbooks such as Remington's Pharmaceutical Sciences, 19th Edition, Mack Publishing Company, Easton, Pa., USA.
[0100] The compounds and compositions of the invention may be administered by any suitable route, and the person skilled in the art will readily be able to determine the most suitable route and dose for the condition to be treated. Dosage will be at the discretion of the attendant physician or veterinarian, and will depend on the nature and state of the condition to be treated, the age and general state of health of the subject to be treated, the route of administration, and any previous treatment which may have been administered.
[0101] The carrier or diluent, and other excipients, will depend on the route of administration, and again the person skilled in the art will readily be able to determine the most suitable formulation for each particular case.
[0102] For the purposes of this specification it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises” has a corresponding meaning.
DETAILED DESCRIPTION OF THE INVENTION
[0103] The invention will now be described in detail by way of reference only to the following non-limiting examples. Abbreviations used herein are as follows:
AcN Acetonitrile Bn Benzyl CH 2 Cl 2 Dichloromethane CHCl 3 Chloroform pClBn para-chlorobenzyl pClBz para-chlorobenzoyl DCM Dichloromethane DMF N,N′-Dimethylformamide DMTST Dimethyl (methylthio) sulphoniumtrifluoro- methanesulphonate EtOAc Ethyl acetate EtOH Ethanol H 2 O Water HRMS High resolution mass spectrometry MDBn 3,4-methylenedioxybenzyl Me Methyl MeCN Acetonitrile MeOH Methanol MgSO 4 Magnesium sulphate NaHCO 3 Sodium hydrogen carbonate NMR Nuclear magnetic resonance PEG Polyethylene glycol Ph Phenyl SOCl 2 Thionyl chloride TBDMS tertiary-butyldimethylsilyl THF Tetrahydrofuran
EXAMPLE 1
Preparation of 3,4-Methylenedioxybenzyl 4,6-O-Benzylidene 2-O-(4-chlorobenzoyl)-β-D-Galactopyranoside Acceptor
[0104] The strategy for this preparation is set out in Reaction Scheme 1.
[0105] Synthesis of α-D-Galactopyranosyl-(1→3)-D-Galactose
[0106] Methyl 6-O-tert-butyldimethylsilyl-1-thio-β-D-galactopyranoside (2)
[0107] A mixture of t-butyldimethylsilyl chloride (68.35 g, 453.51 mmol) and 4-dimethylaminopyridine (55.40 g, 453.51 mmol) in dry 1,2-dichloroethane (800 ml) was stirred at 80° C. for 15 minutes. Methyl 1-thio-β-D-galactopyranoside (1) (100 g, 476.19 mmol) was added in 5 portions in 15 minutes to the stirred solution at 80° C., and the reaction mixture was stirred under reflux for 1 hour. The resulting clear solution was cooled to room temperature, diluted with CHCl 3 (2 000 ml), washed four times with diluted brine solution (water-brine 2:1) (750 ml). The aqueous layers of the last two washings were collected and extracted with CHCl 3 (400 ml). The organic layers were combined, dried over MgSO 4 and evaporated. The residue was kept under high vacuum for 15 min, then was dissolved in dry MeCN (200 ml). The solution was evaporated, and the residue was kept under high vacuum for 15 min. This drying process was repeated using another 200 ml of dry MeCN, to give the crude methyl 6-O-tert-butyldimethylsilyl-1-thio-β-D-galactopyranoside (2) (117.5 g, 80%) as a syrup.
[0108] R f 0.65 (MeCN/H 2 O 10:1) MS (electrospray) C 13 H 28 O 5 SSi (324.23) m/z (%) 347[M+Na] + (100), 325[M+H] + (75).
[0109] Methyl 6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (3)
[0110] A mixture of crude methyl 6-O-tert-butyldimethylsilyl-1-thio-β-D-galactopyranoside (2) (117.46 g, 362.27 mmol), 2,2-dimethoxypropane (66.82 ml, 543.41 mmol) and p-toluenesulphonic acid (200 mg) in dry MeCN (800 ml) was stirred at 40° C. for 30 minutes. The reaction mixture was neutralized with triethylamine (3 ml) and evaporated to give a white crystalline residue (3) (161.3 g)
[0111] R f 0.62 (EtOAc/Hexane 2:1) MS (electrospray) C 16 H 32 O 5 SSi (364.58) m/z (%) 387[M+Na] + (45), 365 M+H] + (100).
[0112] Methyl 6-O-tert-butyldimethylsilyl-2-O-(4-chlorobenzoyl)-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (4)
[0113] A mixture of methyl 6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (3) (155.44 g, 427.03 mmol) and 4-dimethylaminopyridine (62.60 g, 512.44 mmol) in dry 1,2-dichloroethane (750 ml) was stirred at room temperature. 4-Chlorobenzoyl chloride (89.68 g, 512.44 mmol) was added to the stirred reaction mixture in 15 minutes. After the addition the resulting suspension was stirred under reflux for 30 minutes. The reaction mixture was cooled to 10° C. and filtered. The crystalline solid was washed on the funnel with dry 1,2-dichloroethane (300 ml) and filtered. The filtrates were combined, diluted with CHCl 3 (2000 ml) and washed twice with-diluted brine solution (water-brine 2:1) (1500 ml). The organic layer was dried over MgSO 4 and evaporated. The residue was kept under high vacuum for 15 minutes. The resulting syrup was dissolved in dry MeCN (200 ml) and evaporated using high vacuum at the end of the evaporation, to give the crude methyl 6-O-tert-butyldimethylsilyl-2-O-(4-chlorobenzoyl)-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (4) (165 g) as a colourless syrup.
[0114] R f 0.68 (Hexane/EtOAc 2:1) MS (electrospray) C 23 H 35 O 6 SSi (50.3.14), m/z (%) 503[M+H] + (100), 525[M+Na] + (38).
[0115] Methyl 2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (5)
[0116] A mixture of methyl 6-O-tert-butyldimethylsilyl-2-O-(4-chlorobenzoyl)-3,4-isopropylidene-β-D-galactopyranoside (4) (173 g, 344.62 mmol) and p-toluenesulphonic acid (600 mg) in MeOH-MeCN 3:1 (2000 ml) was stirred under reflux for 1 hour. The reaction mixture was cooled to room temperature and evaporated. The resulting white solid residue was suspended in diisopropylether (1000 ml) and filtered. The crystalline solid was washed twice with diisopropylether (300 ml), then with diethylether (500 ml) and dried to give methyl 2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (5) (107 g) as a white crystalline powder.
[0117] R f 0.45 (MeCN/H 2 O 10:1) MS (electrospray) C 14 H 17 ClO 6 S (348.80) m/z (%) 371[M+Na] + (35), 349[M+H] + (100).
[0118] Methyl 2-O-(4-chlorobenzoyl)-4,6-O-benzylidene-1-thio-β-D-galactopyranoside (6)
[0119] A mixture of methyl 2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (5) (94.16 g, 270.57 mmol), α,α-dimethoxytoluene (60.9 ml, 405.86 mmol) and p-toluenesulphonic acid (200 mg) in dry MeCN (500 ml) was stirred at 70° C. for 30 minutes. The reaction mixture was cooled to room temperature, neutralized with triethylamine (3 ml) and evaporated. The residue was taken up in CHCl 3 (1500 ml), washed with diluted brine solution (water-brine. 2:1) (750 ml), with saturated NaHCO 3 solution (500 ml), with diluted brine again (water-brine 2:1) (750 ml), dried over MgSO 4 and evaporated. The resulting white solid was kept under high vacuum for 15 minutes. The dry residue was crystallized from MeCN (250 ml) at room temperature to give 68.5 g pure product. Water (80 ml) was added slowly to the mother liquor, and the solution was left at room temperature to crystallize another 20.8 g of methyl 2-O-(4-chlorobenzoyl)-4,6-O-benzylidene-1-thio-β-D-galactopyranoside (6) (yield: 75%).
[0120] R f 0.65 (EtOAc/Hexane 2:1) MS (electrospray) C 21 H 21 ClO 6 S (436.91) m/z (%) 437[M+H] + (56), 459[M+Na] + (100).
[0121] [0121] 1 H N (CDCl 3 ) δ 8.01-7.37 (9H, aromatic), 5.56 (s, 1H, benzylidene), 5.44 (t, 1H, H-2), 4.5 (d, 1H, J 1-2 =9.0, H-1), 4.38 (dd, 1H, H-6a), 4.30 (dd, 1H, H-4), 4.04 (dd, 1H, H-b), 3.90 (m, 1H, H-3), 3.6 (s, 1H, H-5), 2.25 (s, 3H, S—H 3 ).
[0122] 3,4-Methylenedioxybenzyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (7)
[0123] To a mixture of methyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (6) (10 g, 22.9 mmol), 3,4-methylenedioxybenzyl alcohol (5.6 g, 36.8 mmol) and powdered molecular sieves (5 Å, 15 g) in dry 1,2-dichloroethane (200 mL) at 0° C., was added methyl trifluoromethanesulphonate (6 g, 36.6 mmol) in one portion under nitrogen atmosphere. The reaction mixture was sealed and left to warm to room temperature, and stirred for 3 h. The mixture was then neutralized with triethylamine (15 mL), diluted with CHCl 3 (350 mL) and filtered through celite. The filtrate was washed with saturated NaHCO 3 solution (4×500 mL), and the organic layer was dried over MgSO 4 and evaporated to dryness leaving a white solid. The solid was suspended in diisopropylether (200 mL), filtered, washed with diisopropylether (200 mL) and dried to give 3,4-methylenedioxybenzyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (7) (7.5 g, 61% yield) as a white powder.
[0124] R f 0.60 (CH 2 Cl 2 /EtOH 20:1) MS (electrospray) C 28 H 25 ClO 9 (540.95) m/z (%) 437[M+H] + (56), 558[M+H+NH 3 ] + (100).
EXAMPLE 2
Preparation of Methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-1-thio-β-D-Galactopyranoside Glycosyl Donor
[0125] Methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-1-thio-β-D-galactopyranoside (8)
[0126] To a stirred suspension of sodium hydride (95%) (14.43 g, 571.42 mol) in dry DMF (300 ml) a solution of methyl 1-thio-β-D-galactopyranoside (1) (20 g, 95.23 mmol) in dry DMF (200 ml) was added dropwise at 0° C. in nitrogen atmosphere. At the end of the addition the ice-bath was removed and the reaction mixture was stirred at room temperature for 30 minutes. 4-Chlorobenzyl chloride (97.74 g, 571.42 mmol) was added dropwise to the stirred reaction mixture keeping the temperature 10-20° C. After the addition, the reaction mixture was stirred at room temperature overnight. The resulting suspension was cooled with ice-bath and methanol (11 ml) was added slowly. When the hydrogen formation had stopped, the suspension was evaporated to dryness at 45-50° C. The remaining DMF was removed by co-evaporation with xylene (100 ml). The residue was taken up in CH 2 Cl 2 (500 ml), washed twice with water (500 ml), saturated NaHCO 3 solution (500 ml), dried over MgSO 4 and evaporated. The residue was crystallized from EtOH (500 ml) to give methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-1-thio-β-D-galactopyranoside (8) (40 g, 60%) as a white crystalline solid.
[0127] R f 0.72 (Hexane/EtOAc 3:1) MS (electrospray) C 35 H 34 Cl 4 O 5 S (708.53) m/z (%) 709[M+H] + (100), 731[M+Na] + (48).
EXAMPLE 3
Preparation of 3-O-(α-D-galactopyranosyl)-D-galactopyranose
[0128] 3,4-Methylenedioxybenzyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galac-topyranoside (9)
[0129] Methyl trifluoromethanesulphonate (4 g, 24 mmol) was added under nitrogen to a mixture of 3,4-methylenedioxybenzyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (7) (6.5 g, 12 mmol), methyl 2,3,4,6-tetra-o-(4-chlorobenzyl)-thio-p-D-galactopyranoside (8) (12 g, 17 mmol) and powdered molecular sieves (5 Å, 10 g) in dry 1,2-dichloroethane (250 mL). The sealed reaction mixture was left to warm to room temperature and then stirred for 80 minutes. The reaction mixture was neutralized with triethylamine (12 g) and diluted with CHCl 3 (500 mL). The suspension was filtered through celite and the filtrate was washed with saturated NaHCO 3 solution (3×500 mL). The organic phase was dried over MgSO 4 and evaporated to dryness to give an oily residue. The residue was suspended in diisopropylether (150 mL) and the resulting solid was filtered. The solid was washed with diisopropylether (100 mL) and dried under high vacuum at room temperature to give 3,4-methylenedioxybenzyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (9) (6.7 g, 47%) as a white powder.
[0130] R f 0.50 (EtOAc/Hexane 1:1) MS (electrospray) C 62 H 55 Cl 5 O 14 (1201.38) m/z (%)1221[M+Na] + (80).
[0131] 3,4-Methylenedioxybenzyl 4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (10)
[0132] To a solution of sodium methoxide (280 mg, 10.4 mmol) in dry methanol (50 mL), 3,4-methylenedioxy-benzyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (9) (6.3 g, 5.2 mmol) in dry THF-MeOH 2:1 (150 mL) was added. The resulting mixture was stirred at 40° C. for 5 hours. The reaction mixture was cooled to 18° C. and neutralized (pH 7.0) with Aimberlite IR-120H + cation exchange resin. The resin was filtered off and the filtrate evaporated to dryness to give an oily residue. The &rude product was suspended in hexane (200 mL), which was then vigorously stirred to break up the clumps. The suspension was-filtered and dried in vacuum at room temperature to give 3,4-methylenedioxybenzyl 4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (10) (5.2 g, 93%) as a white powder.
[0133] R f 0.30 (CH 2 Cl 2 /ethanol 50:1), MS (electrospray) m/z C 55 H 52 Cl 4 O 13 (1062.83) m/z (%) 1098[M+K] + (72)
[0134] 3,4-methylenedioxybenzyl 3-O-(α-D-galactopyranosyl)-β-D-galactopyranoside (11)
[0135] To a suspension of Pd/C (10%) catalyst (220 mg) in a mixture of THF-EtOR-H 2 O 6:2:1 (5 mL), a solution of 3,4-methylenedioxybenzyl 4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (10) (200 mg, 0.19 mmol) in a mixture of THF-EtOH-H 2 O 6:2:1 (5 mL) was added. The resulting suspension was shaken under a positive pressure (45 PSI) of hydrogen for 2.5 h. The reaction mixture was filtered through celite and the filtrate was concentrated under high vacuum at room temperature to a volume of approximately 15 mL. The resulting yellow solution was diluted with deionised water (50 mL) and neutralized (pH 7.0) with excess mixed bed resin (Amberlite-MB 1). The aqueous suspension was filtered and the filtrate was evaporated to dryness under high vacuum to give the crude product as a colourless residue. The crude product was purified by chromatography using CHCl 3 -MeOH—H 2 O 5:5:1 as the mobile phase to give 3,4-methylenedioxybenzyl 3-O-(α-D-galactopyranosyl)-β-D-galactopyranoside (11) (72 mg, 73%).
[0136] R f 0.42 (CHCl 3 /MeOH/H 2 O 5:5:1) MS (electrospray) C 20 H 28 O 13 (476.43) m/z (%) 499[M+Na] + (38), 477[M+H] + (72)
[0137] 3-O-(α-D-Galactopyranosyl)-D-galactopyranose (12)
[0138] A mixture of Pd(OH) 2 (20%) Pearlman's catalyst (0.7 g) and 3,4-methylenedioxybenzyl 4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranoside (10) (2.0 g, 1.9 mmol) in a mixture of THF-MeOH—H 2 O 4:1:1 (30 mL) was shaken under a positive pressure (60 PSI) of hydrogen overnight. The reaction mixture was filtered through celite and the filtrate was neutralized with mixed-bed ion exchange resin (Amberlite-MB 1)/negative silver (I) nitrate test/. The reaction mixture was filtered and the filtrate was concentrated to dryness in vacuum at room temperature. The residue was taken up in deionised water (2 mL) and passed through a C18 Sep Pak cartridge eluting with milli-Q-water (30 mL). The filtrate was evaporated under reduced pressure to give 3-O-(α-D-galactopyranosyl)-D-galactopyranose (12) (560 mg, 86%) as a white solid foam.
[0139] TLC (CHCl 3 -MeOH—H 2 O 10:10:2) R f =0.3, High performance anion exchange chromatography with pulsed amperometric detection /HPAE-PAD/ (4×250 mm Dionex CarbopaK-PA1 analytical column with guard column, 150 mM sodium hydroxide at 1 mL/min.) t R =5.0 min., MS (electrospray) m/z 365 [M+Na] + .
[0140] R f 0.30 (CHCl 3 /MeOH/H 2 O 5:5:1) MS (electrospray) C 12 H 22 O 11 (342.29) m/z (%) 406[M+Na+MeCN] + (100), 365[M+Na] + (62)
EXAMPLE 4
Preparation of 2-[2-(2-thiobiphenylcarbonyl)-ethoxy]ethyl 3-O-α-D-galactopyranosyl-β-D-galactopyranoside (23)
[0141] The synthesis of the reagents for this preparation and the preparation scheme itself are set out in Reaction Schemes 2 and 3 respectively.
[0142] Reagents for the Synthesis of 2-[2-(2-Thiobiphenyl-carbonyl)-ethoxy]ethyl 3-O-α-D-Galactopyranosyl-β-D-Galactopyranoside
[0143] 2-[2-(2-Thiobenzoyl)ethoxy]ethanol (14)
[0144] A mixture of 2-[2-(2-chloroethoxy)ethoxy]ethanol (13) (17.1 g, 101 mmol) and cesium thiobenzoate (38.24 g, 142 mmol) in dry DMF (200 ml) was stirred at 75° C. for 1.5 hours. The reaction mixture was cooled to room temperature and evaporated to dryness. The residue was taken up in diethylether (600 ml), washed three times with saturated NaHCO 3 solution (400 ml) and with water (500 ml). The organic phase was dried over MgSO 4 and evaporated to dryness to give 23 g of crude product. The crude residue was purified by chromatography using diethylether as the mobile phase to give 2-[2-(2-thiobenzoyl)ethoxy]ethanol (14) (18.75 g, 68%) as an orange syrup.
[0145] R f 0.60 (diethylether/EtOH 19:1) MS (electrospray) C 13 H 18 O 4 S (270.34) m/z (%) 293[M+Na] + (62), 271[M+H] + (100)
[0146] 3,4-Methylenedioxybenzyl chloride (16)
[0147] A solution of 3,4-methylenedioxybenzyl alcohol (15) (50 g, 328.62 mmol) in CH 2 Cl 2 (50 ml) was cooled to 0° C. and SOCl 2 (250 ml) added dropwise. The reaction mixture was stirred at 0° C. for 1 hour, at room temperature for 4 hours, then evaporated to dryness. The residue was purified by distillation under vacuum to give 3,4-methylenedioxybenzyl chloride (16) (49 g, 87%).
[0148] R f 0.75 (CHCl 3 /EtOAc 20:1)
[0149] Methyl 4,6-O-benzylidene-1-thio-β-D-galactopyranoside (17)
[0150] A mixture of methyl 1-thio-β-D-galactopyranoside (1) (23.6 g, 112 mmol), α,α-dimethoxytoluene (25.62 g, 168 mmol) and p-toluenesulphonic acid (100 mg) in MeCN (500 ml) was stirred at room temperature for 30 minutes. The-reaction mixture was neutralized with triethylamine (1 ml) and evaporated to dryness, followed by a co-evaporation with toluene. The residue was taken up in CH 2 Cl 2 (250 ml), washed twice with brine (250 ml), dried over MgSO 4 and evaporated. The resulting white solid was crystallized from EtOH to give methyl 4,6-O-benzylidene-1-thio-β-D-galactopyranoside (17) (27.5 g, 82%).
[0151] R f 0.32 (EtOAc) MS (electrospray) C 14 H 18 O 5 S (298.36) m/z (%) 321[M+Na] + (32), 299[M+H] + (100)
[0152] Methyl 4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxy-benzyl)-1-thio-β-D-galactopyranoside (18)
[0153] A mixture of methyl 4,6-O-benzylidene-1-thio-β-D-galactopyranoside (17) (20 g, 66.80 mmol) and sodium hydride (95%) (4.80 g, 201.2 mmol) in dry DMF (350 ml) was stirred at 0° C. for 30 minutes, then 3,4-methylenedioxy-benzyl chloride (34.3 g, 201.2 mmol) (16) added in DMF (20 ml). The reaction mixture was stirred at room temperature overnight. Methanol (20 ml) was added and the reaction mixture was evaporated to dryness. The residue was taken up in CH 2 Cl 2 (500 ml), washed twice with brine (500 ml), dried over MgSO 4 and evaporated. The residue was crystallized from 2-propanol (1 l) to give methyl 4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxybenzyl)-1-thio-β-D-galactopyranoside (18) (19 g, 50%).
[0154] R f 0.62 (CHCl 3 /EtOAc 20:1), MS (electrospray) C 30 H 30 O 9 S (566.62) m/z (%) 589[M+Na] + (100), 567[M+H] + (25)
[0155] 2-[2-(2-Thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (19)
[0156] A mixture of methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (6) (10 g, 22.93 mmol), 0.2-[2-(2-thiobenzoyl)ethoxy]ethanol (13) (6.81 g, 25.22 mmol), powdered molecular sieves 4 Å (˜20 g) and dimethyl(methylthio)sulfonium tetrafluoroborate (7.0 g, 35.71 mmol) was stirred in dry 1,2-dichloroethane (100 mL) at 0° C. for 2 hours. The mixture was neutralized with triethylamine (10 mL), diluted with CH 2 Cl 2 (300 mL) and filtered through celite. The filtrate was washed three times with saturated sodium bicarbonate solution (200 mL), dried over MgSO 4 and evaporated to dryness. The residue was suspended in diisopropylether (600 mL) and filtered. The resulting solid was crystallized from ethanol (50 ml), washed with diisopropylether (200 mL) and dried to give 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (19) (10 g, 66%) as a white powder.
[0157] R f 0.30 (Diethylether/EtOAc 2:1), MS (electrospray) C 33 H 35 ClO 10 S (659.15) m/z (%) 681[M+Na] + (70), 659[M+H] + (40)
[0158] 2-[2-(2-Thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-[4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxybenzyl)]-α-D-galactopyranosyl)-β-D-galactopyranoside (20)
[0159] A mixture of 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (19) (8.55 g, 12.99 mmol), methyl 4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxybenzyl)-1-thio-β-D-galactopyranoside (18) (8.00 g, 14.29 mmol), powdered molecular sieves 4A (20 g) and methyl trifluoromethanesulfonate (4.68 g, 28.58 mmol) was stirred in dry 1,2-dichloroethane (100 mL) at room temperature for 2 hours. The mixture was neutralized with triethylamine (4 mL), diluted with CH 2 Cl 2 (200 mL) and filtered through celite. The filtrate was washed three times with saturated NaHCO 3 solution (200 mL), dried over MgSO 4 and evaporated to dryness. The residue was purified by chromatography using diethylether-EtOAc 2:1 as the mobile phase to give 7.5 g-of 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-[4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxybenzyl)]-α-D-galactopyranosyl)-β-D-galactopyranoside (20) (7.5 g, 50%) as a white solid foam.
[0160] R f 0.55 (Diethylether/EtOAc 2:1), MS (electrospray) C 62 H 61 ClO 19 S (1177.67) m/z (%) 1199[M+Na] + (100), 1177 (21)
[0161] 2-[2-(2-Thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(4,6-O-benzylidene-α-D-galactopyranosyl)-β-D-galactopyranoside (21)
[0162] A mixture of 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-[4,6-O-benzylidene-2,3-di-O-(3,4-methylenedioxybenzyl)]-α-D-galactopyranosyl)-β-D-galactopyranoside (20) (7.02 g, 5.97 mmol) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (2.71 g, 11.93 mmol) in the mixture of CH 2 Cl 2 /H 2 O 7:2 (70 ml) was stirred at room temperature for 1 hour. The reaction mixture was filtered, the filtrate was diluted with CHCl 3 (300 ml), washed twice with saturated NaHCO 3 solution (150 ml) and concentrated to dryness. The residue was taken up in hot diisopropylether (150 ml) and the solution was stirred at room temperature for 2 hours. The resulting suspension was filtered, then crystallized from EtOAc (40 ml). The mother liquid was purified by chromatography using diethylether-EtOAc 1:1 mixture as the mobile phase. The purified products were combined to give 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(4,6-O-benzylidene-α-D-galacto-pyranosyl)-β-D-galactopyranoside (21) (3.69 g, 68%).
[0163] R f 0.32 (Diethylether/EtOAc 2:1), MS (electrospray) C 46 H 49 ClO 15 S (909.40) m/z (%) 931[M+Na] + (35), 909[M+H] + (100)
[0164] 2-[2-(2-Thiobenzoyl)ethoxy]ethyl 2-O-(4-chlorobenzoyl)-3-O-α-D-galactopyranosyl-β-D-galactopyranoside (22)
[0165] A mixture of 2-[2-(2-thiobenzoyl)ethoxy]ethyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(4,6-O-benzylidene-α-D-galactopyranosyl)-β-D-galactopyranoside (21) (3.5 g, 3.85 mmol) and p-toluenesulphonic acid (100 mg) in the mixture of acetonitrile-methanol 1:1 (350 ml) was stirred under reflux for 2 hours. The reaction mixture was evaporated to dryness then the residue was chromatographed using MeCN—H 2 O 10:1 as the mobile phase to give 2-[2-(2-thiobenzoyl)ethoxy]ethyl 2-O-(4-chlorobenzoyl)-3-O-α-D-galactopyranosyl-β-D-galactopyranoside (22) (2.46 g, 87%).
[0166] R f 0.42 (MeCN/H 2 O 10:1), MS (electrospray) C 32 H 41 ClO 15 S (733.13) m/z (%) 755[M+Na] + (52), 733[M+H] + (100)
[0167] 2-[2-(2-Thiobiphenylcarbonyl)ethoxy]ethyl 3-O-α-D-galactopyranosyl-β-D-galactopyranoside (23)
[0168] A mixture of 2-[2-(2-thiobenzoyl)ethoxy]ethyl 2-O-(4-chlorobenzoyl)-3-O-α-D-galactopyranosyl-β-D-galactopyranoside (22) (210 mg, 0.287 mmol) and sodium methoxide (9 mg, 0.287 mmol) in dry methanol (15 ml) was stirred at 40° C. for 4 hours. The reaction mixture was cooled to room temperature and biphenylcarbonyl chloride (62.17 mg, 0.287 mmol) was added. After 30 minutes stirring at room temperature, the reaction mixture was evaporated to dryness. The residue was purified by chromatography using MeCN—H 2 O 5:1 as the mobile phase to give 2-[2-(2-thiobiphenylcarbonyl)ethoxy]ethyl 3-O-α-D-galactopyranosyl-β-D-galactopyranoside (23) (120 mg, 62%).
[0169] R f 0.35 (MeCN/H 2 O 10:2), MS (electrospray) C 31 H 42 O 14 S (670.73) m/z (%) 693[M+Na] + (100), 671[M+H] + (20)
EXAMPLE 5
Preparation of 2-Acetamido-2-Deoxy-4-O-[3-O-(α-D-Galactopyranosyl)-β-D-Galactopyranosyl]-D-Glucopyranose (28)
[0170] The general strategy for this preparation is set out in Reaction Scheme 4.
[0171] Methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-1-thio-β-D-galactopyranoside (24)
[0172] A mixture of methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-thio-β-D-galactopyranoside (8) (3.9 g, 5.5 mmol), molecular sieves 4 Å (4 g) in dry THF (30 ml) was stirred at room temperature, then a solution of bromine (1.18 g, 6.66 mmol) in CH 2 Cl 2 (5 ml) was added. The reaction mixture was stirred at room temperature for 10 minutes, then cyclohexene (1 ml) added. To the stirred reaction mixture methyl 4,6-O-benzylidene 2-O-(4-chlorobenzoyl)-β-D-galactopyranoside (6) (2.0 g, 3.7 mmol)was added then the suspension was cooled to −15° C. A solution of silver trifluoromethanesulphonate (1.4 g, 5.5 mmol) in dry THF (10 ml) was added dropwise under-nitrogen atmosphere in 15 minutes. The reaction mixture was kept at 0° C. overnight. The reaction mixture was neutralized with triethylamine (2 ml) and filtered. The filtrate was evaporated to dryness and the residue was taken up in CHCl 3 (300 mL). The solution was washed with saturated NaHCO 3 solution (3×300 mL). The organic phase was dried over MgSO 4 and evaporated to dryness to give an oily residue. The residue was chromatographed using diethylether-ethanol 20:1 as the mobile phase to give methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chloro-benzyl)-α-D-galactopyranosyl)-1-thio-β-D-galactopyranoside (24) (1.60 g, 40%).
[0173] R f 0.30 (Diethylether), MS (electrospray) C 55 H 51 Cl 5 O 11 S (1097.33) m/z (%) 1117[M+Na] + (100), 1095[M+H] + (32)
[0174] Benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (26)
[0175] A mixture of methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-1-thio-β-D-galactopyranoside (24) (430 mg, 0.39 mmol), benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-α-D-glucopyranoside (25) (300 mg, 0.59 mmol), molecular sieves 4 Å (5 g) and methyl trifluoromethane-sulphonate (97 mg, 0.59 mmol) in dry 1,2-dichloroethane (15 ml) was stirred at room temperature overnight. The reaction mixture was neutralized with triethylamine (2 ml) and filtered. The filtrate was diluted with CHCl 3 (100 ml) and was washed with saturated NaHCO 3 solution (2×100 mL). The organic phase was dried over MgSO 4 and evaporated to dryness to give an oily residue. The residue was chromatographed using diethylether-ethanol 25:1 as the mobile phase to give benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (26) (300 mg, 50%).
[0176] R f 0.33 (Diethylether/EtOH 25:1), MS (electrospray) C 83 H 80 Cl 5 NO 17 (1540.83) m/z (%) 1560[M+Na] + (100), 1538[M+H] + (27)
[0177] Benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (27)
[0178] To a solution of sodium methoxide (73 mg, 0.13 mmol) in dry methanol (10 mL), benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-20-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (26) (300 mg, 0.19 mmol was added. The resulting mixture was stirred at 40° C. for 4.5 hours. The reaction mixture was kept at 0° C. for 1 hour and filtered. The solid precipitate was washed with-cold dry MeOH (10 ml) to give benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (27) (190 mg, 67%) as a white powder.
[0179] R f 0.35 (CHCl 3 /MeOH 7:3), MS (electrospray) C 76 H 77 ClNO 16 (1402.27) m/z (%) 1423[M+Na] + (100), 1401[M+H] + (35)
[0180] 2-Acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (28)
[0181] To a suspension of Pd/C (10%) catalyst (1.0 g), benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (27) (190 mg, 0.13 mmol) and acetic acid (3 drops) was shaken under a positive pressure (45 PSI) of hydrogen for 4 hours. The reaction mixture was filtered through celite and the filtrate was neutralized (pH 7.0) with excess mixed bed resin (Amberlite-MB 1). The resin was filtered off and the filtrate was evaporated to dryness. The residue was taken up in milli-Q water (10 mL) and the resulting solution was filtered using a 0.22 μm filter. The filtrate was passed through a C-18 Sep-pak cartridge (1 g). The filtrate was evaporated-to dryness and the remaining solid was further dried over phosphorus pentoxide at room temperature under high vacuum to give 2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (28) (32 mg, 43%) as a white solid.
[0182] R f 0.36 (CHCl 3 /MeOH/H 2 O 10:12:3), MS (electrospray) C 20 H 35 NO 16 (545.50) m/z (%) 568[M+Na] + (100), 546[M+H] + (52)
EXAMPLE 6
Alternative Synthesis of Compound (28)
[0183] Compound (28) may also be prepared using a different glucosamine acceptor, benzyl-6-O-benzoyl-3-O-benzoyl 1-2-acetamido-2-deoxy-x-D-glucopyranoside, using the strategy set out in Reaction Scheme 5. The acceptor can readily be prepared in high yield.
[0184] 2-Acetamido-2-deoxy-D-glucopyranose (29)
[0185] Sodium (23.4 g, 1.02 mol) was reacted with dry methanol (1.6 L), then the resulting solution was cooled to 40° C. Glucosamine hydrochloride (200 g, 0.926 mol) was added to the solution and the reaction mixture was stirred vigorously for 5 minutes. The suspension was filtered in dry conditions. Acetic anhydride (140 mL, 1.48 mol) was added dropwise to the filtrate at 0° C. in 30 min. The resulting suspension was stirred at room temperature for another 30 minutes. The reaction mixture was diluted with ether (2 L), filtered and the solid product was dried to give 2-acetamido-2-deoxy-D-glucopyranose (29) (177 g, 86%).
[0186] Benzyl 2-acetamido-2-deoxy-α-D-glucopyranoside (30)
[0187] A mixture of 2-acetamido-2-deoxy-D-glucopyranose (29) (150 g, 0.68 mol), Amberlite IR 120 [H] + ) ion exchange resin (150 g) in benzyl alcohol (1.25 L) was stirred at 80° C. for 3.5 hours. The reaction mixture was filtered. The filtrate was evaporated under reduced pressure at 90 C°. The residue was taken up in hot isopropanol (600 mL) and filtered. The filtrate was left to crystallize, the white crystalline solid was filtered off, washed twice with cold isopropanol (200 mL) and twice with ether (200 mL) to give 2-acetamido-2-deoxy-α-D-glucopyranoside (30)(56.2 g, 27%).
[0188] Benzyl 4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (31)
[0189] Benzyl 2-acetamido-2-deoxy-α-D-glucopyranoside (30) (50 g, 0.16 mmol)-was dissolved in dry DMF (200 mL). Dry acetonitrile (100 mL), α,α-dimethoxytoluene (29 g, 0.19 mol, 1.2 eq) and p-toluenesulphonic acid (50 mg) was added to the DMF solution. The reaction mixture was stirred at 80° C. for 2 hours under vacuum (350 mbar); the product started to precipitate after 1 hour. The resulting suspension was cooled (60° C.) and the pH adjusted to 7 by addition of triethylamine. The suspension was cooled to 0° C., and cold methanol (500 mL) (−10° C.) was added slowly to the mixture. The product was filtered, washed with cold methanol (200 mL) then with cold ether (2×200 mL) to give benzyl 4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (31) (48 g, 75%)
[0190] Benzyl 3-O-benzyl-4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (32)
[0191] A suspension of sodium hydride (3.6 g, 0.15 mol, 1.2 eq) in dry DMF (25 mL) was cooled to 0° C., and a solution of benzyl 4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (32) (50 g, 0.125 mol) in dry DMF (450 mL) was added dropwise in 30-minutes. The resulting solution was stirred at 0° C. for 30 minutes and benzyl bromide was added (25.66 g, 0.15 mol, 1.2 eq) dropwise at 0° C. (the product started to precipitate at the beginning of the addition of the benzyl bromide). The reaction mixture was stirred at room temperature for 45 minutes, cooled to 0° C. and dry methanol (25 mL) was added dropwise. The reaction mixture was diluted with cold ether (1 L) and the mixture was stirred for 30 minutes. The resulting suspension was filtered and washed three times with ether (400 mL) to give benzyl 3-O-benzyl-4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (32) (62.0 g) as a white powder with quantitative yield.
[0192] Benzyl 3-O-benzyl-2-acetamido-2-deoxy-α-D-glucopyranoside (33)
[0193] A suspension of benzyl 3-O-benzyl-4,6-O-benzylidene-2-acetamido-2-deoxy-α-D-glucopyranoside (32) (50 g, 0.102 mol) in acetic acid (500 mL) and water (25 mL) was stirred at 110° C. for 45 minutes. The reaction mixture was concentrated under reduced pressure at 40 C°. The oily residue was taken up twice in toluene (200 mL) and concentrated. The residue was treated with di-isopropyl ether (250 mL) and the resulting suspension was stirred for 30 minutes. The white solid was filtered off, washed twice with cold ether (200 mL) to give benzyl 3-O-benzyl-2-acetamido-2-deoxy-α-D-glucopyranoside (33) (38.0 g, 93%).
[0194] Benzyl 6-O-benzoyl-3-O-benzyl-2-acetamido-2-deoxy-α-D-glucopyranoside (34)
[0195] A solution of benzoyl chloride (6.3 g, 0.045 mol, 1.2 eq) and imidazole (6 g, 0.09 mol, 2.4 eq) in dry 1,2-dichloroethane (150 mL) was stirred for 20 minutes at 5° C. The resulting suspension was filtered under dry conditions. The filtrate was added to a solution of benzyl 3-O-benzyl-2-acetamido-2-deoxy-α-D-glucopyranoside (33) (15 g, 37.6 mmol) in dry 1,2-dichloroethane (600 mL). The-reaction mixture was stirred at 90° C. for 48 hours and cooled to room temperature. The resulting suspension was filtered, washed twice with brine (300 mL), dried over MgSO 4 and concentrated. The residue was taken up in hot isopropanol (300 mL) and left to crystallize. The white crystalline solid was filtered off to give Benzyl 6-O-benzoyl-3-O-benzyl-2-acetamido-2-deoxy-α-D-glucopyranoside (34) (11.7 g, 62%).
[0196] Methyl 4,6-O-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (35)
[0197] A mixture of methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (6) (10.0 g, 23 mmol) and 4-dimethylaminopyridine (3.40 g, 27.8 mmol) in dry 1,2-dichloroethane (100 mL) was stirred at 0° C., then chloroacetyl chloride (3.4 g, 27.8 mmol, 1.2 eq) was added dropwise to the solution. The reaction mixture was stirred at room temperature for 2.5 hours, then diluted with 1,2-dichloroethane (100 mL). The resulting solution was washed twice with saturated brine solution (100 ml), dried over MgSO 4 and concentrated to give methyl 4,6-O-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (35) (10.2 g, 86%) as a white crystalline solid.
[0198] Benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-O-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-β-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (36)
[0199] To a mixture of benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-2-deoxy-α-D-glucopyranoside (34) (5 g, 9.9 mmol), methyl 4,6-O-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside (35) (5.71 g, 11.1 mmol, 1.12 eq) and Molecular sieves 4A (2.5 g) in dry 1,2-dichloroethane (300 mL), DMTST (5.75 g, 2.4 eq) was added under nitrogen. The reaction mixture was stirred at room temperature for 5 hours, then neutralized by addition of pyridine (5 mL). Acetic anhydride was added (2.5 mL) and the reaction mixture was stirred at room temperature for 0.5 hours. The resulting suspension was filtered through a bed of Celite. The filtrate was washed with a saturated solution of NaHCO 3 (200 mL), twice with brine (200 ml), dried over MgSO 4 and concentrated. The residue was taken up in DCM (25 mL) and diisopropyl ether (200 mL) was added. The resulting yellow precipitate was filtered off and washed twice with cold diisopropyl ether (100 mL). The solid was crystallized using a mixture of DCM (20 mL) and ether (25 mL) to give benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-O-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-β-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (36) (5.1 g, 0.55%) as a white crystalline solid.
[0200] Benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-β-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (37)
[0201] A mixture of benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-o-benzylidene-3-O-chloroacetyl-2-O-(4-chlorobenzoyl)-β-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (36) (0.5 g) and thiourea (303 mg) in THF (3 mL) and water (0.5 mL) was stirred at room temperature for 14 hours, then the reaction mixture was diluted with chloroform (100 mL). The resulting solution was washed twice with water (50 ml), dried over MgSO 4 and concentrated. The residue was purified by flash chromatography using DCM/EtOAc 1:1 as the mobile phase to give benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-β-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (37) (280 mg, 61%) as a white solid.
[0202] Benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O--(4-chlorobenzyl)-α,β-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (38)
[0203] To a mixture of methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-1-thio-β-D-galactopyranoside (430 mg, 0.602 mmol), benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-o-D-galactopyranosyl]-2-deoxy-α-D-glucopyranoside (37) (280 mg, 0.301 mmol) and molecular sieves 4 Å (300 mg) in dry 1,2-dichloroethane (3 mL), DMTST (300 mg, 1.2 mmol) was added. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was neutralized with triethylamine (1 ml)., diluted with CHCl (50 mL) and filtered. The filtrate was then washed with-saturated NaHCO 3 solution (3×50 mL). The organic phase was dried over MgSO 4 and evaporated to dryness to give a solid foam. The residue was purified by chromatography using CHCl 3 — EtOAc 1:1 as the mobile phase to give benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α,β-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (38) (325 mg, 70%, α/β=85/15).
[0204] Benzyl 2-acetamido-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (39)
[0205] To a solution of sodium methoxide (20 mg, 0.37 mmol) in dry methanol (2 mL), benzyl 2-acetamido-6-O-benzoyl-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α,β-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (38) (190 mg, 0.12 mmol was added. The resulting mixture was stirred at 40° C. for 4 hours. The reaction mixture was cooled to room temperature and filtered. The solid precipitate was washed with cold dry MeOH (10 mL), followed by hexane (2×25 mL) to give benzyl 2-acetamido-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (39) (110 mg, 68%) as a white powder. TLC R f 0.35 (EtOAc/CHCl 3 7:3
[0206] 2-Acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (28)
[0207] To a suspension of Pd/C (10%) catalyst (100 mg), benzyl 2-acetamido-3-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-α-D-glucopyranoside (39) (80 mg, 0.06 mmol) and acetic acid (3 drops) in THF-MeOH—H2O 5:1:1 (7 mL) was shaken under a positive pressure (60 PSI) of hydrogen overnight. The reaction mixture was diluted with milliQ water (30 mL), filtered through Celite and the filtrate was neutralized (pH 7.0) with excess mixed bed resin (Amberlite-MB 1). The resin was filtered off and the filtrate was evaporated to dryness. The residue was taken up in milli-Q water (5 mL) and the resulting solution was passed through a C-18 Sep-pak cartridge (1 g). The filtrate was evaporated to dryness and the remaining solid was further dried over phosphorus pentoxide at room temperature under high vacuum to give 2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (28). (20 mg, 53%) as a white solid.
[0208] R f 0.36 (CHCl 3 /MeOH/H 2 O 10:12:3), MS (electrospray) C 20 H 35 NO 16 (545.50) m/z (%). 568[M+Na] + (100), 546[M+H] + (52)
EXAMPLE 6
Immobilization of 2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (28)
[0209] The following reaction scheme, Scheme 6, illustrates how a compound of the invention can be bound to a solid support, using two alternative linking groups. The second linking group is a dioxo compound, as discussed in our International patent application No. PCT/AU98/00808. It will be appreciated that other compounds of the invention can be linked to a solid support in a similar manner.
EXAMPLE 7
Synthesis of Methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-fluorenylmethyl-oxycarbonyl-1-thio-β-D-galactopyranoside
[0210] Methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-fluorenylmethyloxycarbonyl-1-thio-B D-galactopyranoside (43)
[0211] A suspension of methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-1-thio-β-D-galactopyranoside 6 [20 g, 45.87 mmol] in 1,2-dichloroethane [200 mL was cooled to 0° C. To the cooled suspension was added DMAP [16.81 g, 138 mmol] followed by Fmoc-Cl [35.60 g, 137 mmol]]. The now solution was returned to ambient temperature and stirred for 2 hours. The reaction mixture was then diluted with Chloroform [200 mL, and washed with 5% citric acid solution [2×400 mL] and saturated brine solution [2×400 mL. The layers were separated and the organic layer dried over Na 2 SO 4 followed by filtration and removal of the solvent in vacuo. The resulting residue was purified by column chromatography [20% ethylacetate/petroleum ethers v/v] to afford methyl 4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-fluorenylmethyloxycarbonyl-1-thio-β-D-galactopyranoside 43 as a white foam [27.2 g, 90%]; R f =0.22; ES-MS gave m/z (ion, relative intensity); 1 H NMR (CDCl 3 ) δ 7.88-7.07 (17H, aromatic), 6.01 (t, 1H, H-2), 5.79 (s, 1H, benzylidene) 5.36 (dd, 1H, H-3), 4.91 (d, 1H, J 1-2 =8.5, H-1), 4.89 (d, 1H, H-4), 4.78 (dd, 1H, H-6 a ), 4.67 (m, 2H, Fluorenyl-CH 2 —), 4.52 (t, 1H, 9-fluorenylmethyne), 4.49 (dd, 1H, H-6 b ), 4.14 (s, 1H, H-5), 2.29 (s, 3H, S—CH 3 )
EXAMPLE 8
Synthesis of Methyl 4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-2-O-pivaloyl-1-thio-β-D-galactopyranoside
[0212] Methyl 6-O-tert-butyldimethylsilyl)-3,4-O-isopropylidene-2-O-(pivaloyl)-1-thio-β-D-galactopyranoside (44)
[0213] To a mixture 6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside [11.5 g, 31.59 mmol] and DMAP [5.5 g, 45.5 mmol] in 1,2-dichloroethane [40 mL) was added dropwise, 2,2,2-trimethylacetylchloride. The reaction was stirred for 2 hours then diluted with chloroform [100 mL] and washed with 10% citric acid solution [2×150 mL], saturated NaHCO 3 solution (2×150 mL] and saturated brine solution [2×150 mL]. The layers were separated and the organic layer dried over Na 2 SO 4 . The solvent was removed in vacuo to give an oily residue. The residue was purified by column chromatography (5% ethylacetate/petroleum ethers) to give a white foam, methyl 6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-2-O-pivaloyl-1-thio-β-D-galactopyranoside 44 (13.7 g, 97%]. R f =0.75 (ethylacetate/petroleum ethers, 1:2, v/v); 1 H NMR (CDCl 3 ) δ 5.05 (dd, 1H, H-2), 4-29 (dd, 1H, H-4), 4.25 (d, 1H, J 1-2 =10.12, H-1), 4.17 (dd, 1H, H-3), 3.93-3.84 (m, 3H, H-6 a , H-6 b , H-5), 2.16 (s, 3H, S—CH 3 ),
[0214] Methyl 2-O-pivaloyl-1-thio-β-D-galactopyranoside (45)
[0215] Methyl 6-O-tert-butyldimethylsilyl-2-O-pivaloyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside 44 (3.34 g, 7.45 mmol] x, was dissolved in 25% acetonitrile/methanol [40 mL]. To the solution was added 4-toluenesulphonic acid [17 mg, 90.43 μmol], the solution was then stirred under refluxed for 3 hours. The reaction temperature was then reduced to 40° C. and left overnight. The reaction mixture was then concentrated and the residue azeotroped with toluene followed by diethylether to give a white residue. The residue was purified by column chromatography (10% acetonitrile/ethylacetate, v/v) to give a white solid, methyl 2-O-pivaloyl-1-thio-β-D-galactopyranoside 45 [2.19 g, 83%], R f =0.20 (ethylacetate); ES-MS m/z (ion, relative intensity). 295 ([M+H] + , 100%); 1 H NMR (CDCl 3 ) δ 5.08 (dd, 1H, H-2), 4.39 (d, 1H, J 1-2 =9.88 Hz, H-1), 4.13 (d, 1H, H-4), 4.01-3.92 (m, 2H, H-6 a , H-6 b ), 3.72 (dd, 1H, H-3), 3.62 (dd, 1H, H-5), 2.21 (S, 3H, S—CH 3 ), 1.27 (s, 9H, t-butyl).
[0216] Methyl 4,6-O-benzylidene-2-O-pivaloyl-1-thio-β-D-galactopyranoside (46)
[0217] A mixture of methyl 2-O-(pivaloyl)-1-thio-β-D-galactopyranoside 45 [1.68 g, 5.71 mmol], α,α-dimethoxytoluene and 4-toluenesulphonic acid [10 mg, 43.19 mmol] was dissolved in acetonitrile [50 mL] and heated at 60° C. with stirring for 1 hour. The reaction was then allowed to return to ambient temperature, neutralised with 2 equivalents of triethylamine and concentrated under vacuum. The residue was taken up in chloroform [100 mL] and the organic layer washed with dilute brine [3:1; H 2 O:Brine, 1×100 mL], saturated NaHCO 3 solution [1×100 mL], and saturated brine solution [1×100 mL]. The layers were separated and the organic layer dried over Na 2 SO 4 . The organic layer was concentrated and the residue purified by column chromatography (33% ethylacetate/petroleum ethers, v/v) to give methyl 4,6-O-benzylidene-2-O-pivaloyl-1-thio-β-D-galactopyranoside 46 [1.91 g, 87%]. R f =0.63 (ethylacetate), ES-MS m/z (ion, relative intensity) 341 ([M+H] + , 100%); 1 H NMR (CDCl 3 ) δ 7.51 (m, 2H, aromatic) 7.41 (m, 3H, aromatic), 5.58 (s, 1H, CH-benzylidene), 5.24 (dd, 1H, H-2), 4.4 (dd, 1H, H-6 a ), 4.39 (d, 1H, J 1-2 =9.77, H-1), 4.29 (dd, 1H, H-4), 4.08 (dd, 1H, H-6 b ), 3.8 (ddd, 1H, H-3), 3.60 (s, 1H, H-5), 2.26 (s, 3H, S—CH 3 ), 1.27 (s, 9H, t-butyl)
[0218] Methyl 4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-2-O-pivaloyl-1-thio-β-D-galactopyranoside (47)
[0219] Methyl 4,6-O-benzylidene-2-O-pivaloyl-1-thio-β-D-galactopyranoside 46 [1.90 g, 4.97 mmol] was dissolved in 1,2-dichloroethane (20 mL) and the resulting solution was cooled to 0° C. At this time DMAP [1.82 g, 14-92 mmol] and. Fmoc-Cl [3.87 g, 14.92 mmol] were added sequentially. The cold bath was then removed, and the reaction allowed to return to room temperature. The reaction was stirred at ambient temperature for 2 hours and then diluted with CHCl 3 [˜50 mL]. The reaction mixture was then washed with 5% citric acid solution [2×100 mL] and saturated brine solution [2×100 mL]. The layers were separated and the organic layer dried over Na 2 SO 4 . The solution was then filtered and concentrated to afford a yellow residue which was purified by column chromatography (20% ethylacetate/petroleum ethers v/v) to give methyl 4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-2-O-pivaloyl-1-thio-β-D-galactopyranoside 47 [2.74 g, 91%]; R f =0.38 (25% ethylacetate/petroleum ethers v/v); ES-MS m/z (ion, intensity); 1 H NMR (CDCl 3 ) δ 7.78-7.25 (13H, aromatic), 5.61 (t, 1H, H-2), 5.57 (s, 1H, benzylidene), 4.97 (dd, 1H, H-3), 4.50 (d, 1H, H-4), 4.45 (d, 1H, J 1-2 =9.10 hz, H-1), 4.47-4.33 (m, 2H, Fmoc-CH 2 —), 4.25 (t, 1H, 9-fluorenylmethyne), 4.40, (dd, 1H, H-6 a ) 4.08 (dd, *1H, H-6 b ) 3.65 (s, 1H, H-5), 2.30 (s, 3H, S—CH 3 ), 1.20 (s, 9H, t-butyl)
EXAMPLE 9
Synthesis of Synthesis of Methyl 2-O-acetyl-4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-1-thio-β-D-galactopyranoside
[0220] Synthesis of Methyl 2-O-acetyl-6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (48)
[0221] A mixture of methyl 6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside (3.0.0 g, 8.24 mmol) and 4-dimethylaminopyridine (2.42 g, 19.78 mmol) in dry 1,2-dichloroethane (750 ml) was stirred at room temperature. Acetyl chloride [1.05 mL, 14.84 mmol] was added dropwise to the solution over 15 minutes. The reaction stirred at room temperature for 2 hours at which time it was diluted with chloroform and washed with 10% citric acid solution [2×100 mL] saturated sodium hydrogen carbonate [2×100 mL] and finally with saturated brine solution [2×100 mL]. The layers were separated and the organic layer dried over Na 2 SO 4 . The solution was filtered and concentrated to afford a white residue which was purified by column chromatography (20% ethylacetate/petroleum ethers v/v) to afford methyl 2-O-acetyl-6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside 48 as a white solid [2.65 g, 79%]; R f =0.43 (25% ethylacetate/petroleum ethers v/v)
[0222] Synthesis of Methyl 2-O-acetyl-1-thio-β-D-galactopyranoside (49)
[0223] 2-O-Acetyl-6-O-tert-butyldimethylsilyl-3,4-O-isopropylidene-1-thio-β-D-galactopyranoside x was dissolved in 50% acetonitrile/methanol [50 mL] and heated at 60° C. To the stirred solution was added 4-toluenesulphonic acid [10 mg, 53.19 μmol] and the reaction was left for 4 hours. The reaction temperature was then reduced to 40° C. and left overnight. The reaction mixture was then concentrated and the residue crystallised from methanol to afford 2-O-acetyl-1-thio-β-D-galactopyranoside 49 as a white solid [1.26 g, 79%]; R f =0.2 (25% acetonitrile/ethylacetate, v/v); 1 H NMR (d-MeOH) δ 3.95 (t, 1H, H-2), 3.27 (d, 1H, J 1-2 =8.63, H-1), 2.92, 1H, H-4), 2.79-2.69 (m, 2H, H-6 a and H-6 b ), 2.62 (t, 1H, H-3), 2.38 (m, 1H, H-5) 1.37 (s, 3H, S—CH 3 ), 1.31 (s, 3H, —C(O)CH 3 )
[0224] Synthesis of Methyl 2-O-acetyl-4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-1-thio-β-D-galactopyranoside (50)
[0225] 2-O-Acetyl-1-thio-β-D-galactopyranoside 49 was dissolved in acetonitrile [20 mL] and heated to 60° C. To the stirred solution was added α,α-dimethoxytoluene [1.09 g, 7.10 mmol] and 4-toluenesulphonic acid [10 mg, 53.19 μmol]. The reaction was stirred for 2 hours and then allowed to return to room temperature. The reaction was neutralised with 2 equivalents of triethylamine and evaporated to dryness. The residue was taken up in chloroform and washed with dilute brine [1×100 mL], saturated sodium hydrogencarbonate solution [1×100 mL] and saturated brine solution [1×100 mL]. The layers were separated and the organic layer dried over Na 2 SO 4 . The solution was filtered and concentrated. The residue was washed successively with petroleum ethers, and the resulting white solid then suspended in toluene and any remaining water azeotroped under co-evaporation. The residue from the previous step was suspended in 1,2-dichloroethane [20 mL] and cooled to 0° C. To the stirred suspension at 0° C. was added 4,4-dimethylaminopyridine [1.62 g, 13.23 mmol] and Fmoc-Cl [3.42 g, 12.23 mmol]. The now solution was allowed to return to room temperature and stirred for 1 hour. At this time the reaction was diluted with chloroform and washed with 5% citric acid solution [2×75 mL] and saturated brine solution [2×75 mL]. The layers were then separated and the organic layer dried over Na 2 SO 4 . The solution was filtered and the solvent removed in vacuo to give a yellow oily residue which was purified by column chromatography (33% ethylacetate/petroleum ethers v/v) to give methyl 2-O-acetyl-4,6-O-benzylidene-3-O-fluorenylmethyloxycarbonyl-1-thio-β-D-galactopyranoside 50 [2.19 g, 82%] R f =0.2 (33% ethylacetate/petroleum ethers, v/v); 1 H NMR (CDCl 3 ) δ 7.78-7.24 (13H, aromatic), 5.60 (t, 1H, H-2), 5.55 (s, 1H, benzylidene), 4.88 (dd, 1H, H-2), 4.50 (d, 1H, H-4), 4.55-4.38 (m, 4H, H-1, Fmoc-CH 2 , H-6 a ), 4.28 (t, 1H, 9-fluorenyl-methyne), 4.06 (dd, 1H, H-6 b ), 3.63 (s, 1H, H-5), 2.29 (s, 3H, S—CH 3 ), 2.1 (s, 3H, —C(O)CH 3 )
EXAMPLE 10
Synthesis of a Partially Protected Resin-Linker-Sugar Conjugate
[0226] Benzyl 3,6-di-O-benzyl-2-deoxy-2-amino-β-D-glucopyranoside (51)
[0227] To a solution benzyl of 3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside [6.20 g, 10.71 mmol] in ethanol [100 mL], was added hydrazine hydrate [6.2 mL, 55%/H 2 O] and water [5 mL]. The solution was refluxed overnight and then allowed to return to ambient temperature. The solution was filtered, the solvent removed in vacuo, and the residue taken up in CHCl 3 [200 mL]. The Chloroform suspension was filtered, the filtrate dried over Na 2 SO 4 and concentrated under reduced pressure to give a pure clear oil, benzyl 3,6-Di-O-benzyl-2-deoxy-2-amino-β-D-glucopyranoside 51 [4.7 g, 97%); R f =0.5 (Acetonitrile), ES-MS gave m/z (ion, relative intensity): 450 ([M+H] + , 100%); 1 H NMR (CDCl 3 ) δ 7.43-7.30 (m 15H, aromatic), 5.00-4.60 (6H, 3CH 2 —C 6 H 5 ), 4.38 (d, 1H, J 1-2 =7.92 Hz, H-1), 3.85-3.75 (m, 3H, H-6 a , H-6 b , H-3), 3.53 (ddd, 1H, H-5), 3.38 (dd, 1H, H-3), 2.92 (dd, 1H, H-2).
[0228] Benzyl 3,6-Di-O-benzyl-2-deoxy-2-N-(6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-pentanoic acid-6-yl)-β-D-glucopyranoside (52)
[0229] To a solution of Benzyl 3,6-Di-O-benzyl-2-deoxy-2-amino-β-D-glucopyranoside 51 [4.70 g, 10.47 mmol] in ethanol [100 mL], was added 6-hydroxy-6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-pentanoic acid [5.32 g, 20.93 mmol] followed by the addition of triethylamine [1.5 mL, 10.69 mmol]. The reaction mixture was heated overnight at 60° C. and then allowed to return to room temperature. The reaction mixture was concentrated and the residue taken up in chloroform [200 mL]. The organic layer was washed with a solution of 0.3N HCl [2×200 mL] and saturated Brine solution [1×200 mL]. The organic layer was dried over Na 2 SO 4 and concentrated to give a pale yellow residue. The residue was purified by column chromatography with ethylacetate-petroleum ethers-acetic acid, 5:15:0.4 to give benzyl 3,6-Di-O-benzyl-2-deoxy-2-N-(6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-pentanoic acid-6-yl)-β-D-glucopyranoside 52 [6.09 g, 85%]. R f =0.10 (ethylacetate-petroleum ethers-acetic acid, 5:15:0.4), ES-MS m/z (ion, relative intensity): 686.5 ([M+H] + , 100%)
[0230] Coupling of Benzyl 3,6-Di-O-benzyl-2-deoxy-2-N-(6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-pentanoic acid-6-yl)-β-D-glucopyranoside to MBHA resin (0.7 mmol/g) (53)
[0231] In a 200 mL peptide reaction vessel MBHA resin [11.86 g, 8.30 mmol] was swollen in a minimum of dry N,N-dimethylformamide (DMF). A DMF [50 mL] solution was made of Benzyl 3,6-Di-o-benzyl-2-deoxy-2-N-(6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-pentanoic acid-6-yl)-β-D-glucopyranoside 52 [6.09 g, 8.90×mmol], diisopropylethylamine (DIPEA) [3.11 mL, 17.8 mmol] and O-Benzotriazole-1-yl-N,N,N′,N′-tetramethyluroniumhexa-fluorophosphate (HBTU) [3.37 g, 8.9 mmol] which was then added to the reaction vessel. The vessel was sealed and shaken overnight. Ninhydrin assay indicated that the reaction was greater than 99.4% complete, the reaction was stopped, and the resin was washed with DMF [4×100 mL], 50% DCM/MeOH [4×100 mL] and DCM [4×100 mL]. The resin was dried under house vacuum for 4 hours and then dried under high vacuum overnight. Yield of resin 53 was [17.15 g, 98.6% by weight].
[0232] Synthesis of Benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-pivaloyl-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside (58)
[0233] Under an atmosphere of nitrogen, resin 53 (300 mg, 141 μmol], 4,6-O-benzylidene-3-O-fluorenylmethyloxycarbon-yl-2-O-pivaloyl-1-thio-β-D-galactopyranoside 47 [557 mg, 846 μmol] and powdered molecular sieves 4 Å [600 mg], were suspended in dichloromethane [3 mL], followed by the addition of methyl trifluoromethanesulphonate [95.7 μL, 846 μmol]. The reaction vessel was sealed and the reaction mixture agitated for five hours at ambient temperature. The resin was then washed with DMF [3×20 mL], 50% MeOH/DCM [3×20 mL] and DCM [3×20 mL]. The resin was then floated in DCM to separate the resin from any remaining sieves. Resin 54 was collected and dried under house vacuum for 1 hour. The resin was then treated with a 20% triethylamine/DMF solution for 25 mins followed by workup as above. Resin 55 was dried under hi-vacuum overnight. Under an atmosphere of nitrogen the resin was then combined with methyl 2,3,4,6-tetra-O-(4-chlorobenzyl)-1-thio-β-D-galactopyranoside 8 [600 mg, 846 μmol], powdered molecular sieves 4 Å[800 mm] and dichloromethane [4 mL], followed finally by the addition of methyl trfluoromethanesulphonate [95.74 μL, 846 μmol]. The reaction vessel was sealed and the reaction mixture agitated at ambient temperature for five hours. The resin was then washed as standard and collected and dried on a sintered funnel. In a reaction vessel resin 56 was then combined with a 5% hydrazine hydrate (55%/H 2 O)/DMF [5 mL] solution and agitated at ambient temperature for 4 h. The DMF solution was filtered from the resin and the resin then further washed with DMF [7 mL3. The filtrates were combined and the solvent removed in vacuo. The residue was taken up in minimal dichloromethane and passed through a plug of silica (eluent; DCM, TLC: CH 2 Cl 2 :MeOH, 20:0.3). The combined fractions were concentrated, residue 57 was then taken up in 1,2-dichloroethane [3 mL] and reacted with acetylchloride [46 μL, 648 μmol] in the presence of DMAP [84 mg, 684 μmol] for three hours at ambient temperature. The reaction was diluted with chloroform [20 mL] and washed with saturated citric acid solution [2×20 m], saturated sodium hydrogen carbonate solution (2×20 mL] and saturated brine solution [2×20 mL]. The organic layer was separated, dried over Na 2 SO 4 and concentrated to give a white solid residue. The residue was purified by column chromatography (0.5% MeOH/DCM, v/v) to give 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-pivaloyl-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside 58 (213 mg, 76.3%). R f =0.57 (66% ethylacetate/petroleum ethers, v/v), ES-MS m/z (ion, intensity) 1486.29 ([M+H] + 100%)
[0234] In a cognate experiment to experiment 58, compound 47 was substituted with compound 43 (the experiment employing resin 53 (425 mg, 0.199 mmol/g)), to afford 2-acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-2-O-(4-chlorobenzoyl)-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside 59 (96 mg, 34%), R f =0.23 (1.64% methanol/dichloromethane, v/v), ES-MS m/z (ion, intensity) 1543.29 ([M+H] + 100%)
[0235] In a further cognate experiment to experiment 58, compound 47 was substituted with compound 50 to afford 2-amino-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside 60, R f =0.5 (1.96% methanol/dichloromethane, v/v), ES-MS m/z (ion, intensity) 1360.73 ([M+H] + 100%)
[0236] Synthesis of 2-Acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzyli-dene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyrano-syl)]-β-D-glucopyranoside (61)
[0237] 2-Acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzyli-dene-2-O-pivaloyl-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside 58 [288 mg, 188 μmol] was suspended in a solution of NaOMe/MeOH [0.13M, 10 mL] to which was added acetonitrile [5 mL]. The reaction was heated at 70° C. until TLC indicated that the reaction had gone to completion (4-5 days). The reaction mixture was then concentrated and taken up in dichloromethane [20 mL] and washed with 10% citric acid solution [2×20 mL] and saturated brine solution [2×20 mL]. The organic layer was separated, dried over Na 2 SO 2 and the solvent removed in vacuo to provide a solid white residue. The residue was purified by preparative thin layer chromatography (eluent: 13% Acetone/DCM) to give 2-Acetamido-3,6-di-O-benzyl-2-deoxy-4-O-[4,6-O-benzyli-dene-3-O-(2,3,4,6-tetra-O-(4-chlorobenzyl)-α-D-galactopyranosyl)-β-D-galactopyranosyl)]-β-D-glucopyranoside 61 [189 mg, 69%]. R f 0.24 (1.47% MeOH/DCM); ES-MS m/z (ion, intensity) 1403.29 ([M+H] + , 100%)
[0238] Synthesis and Immobilisation of Gal-α-(1-3)-Gal-β-(1-4)-GlcNAc-Linker Conjugate.
EXAMPLE 11
Synthesis of Sugar-Linker Conjugate
[0239] 2-Acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranosylamine (62)
[0240] A solution of 2-Acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranose (1 g, 1.8 mmol) 28 and ammonium bicarbonate (0.15 g, 1.9 mmol) in 30% aqueous ammonia (20 mL) was left to stir at 40° C. for 48 h. The reaction mixture was then freeze dried to give 62 (1.0 g, ˜80% yield by tlc) as a white solid.
[0241] Tlc R f 0.2 (AcN:water, 3:1)
[0242] 1-N-(3-chloropropyl)-1-N′-ureido-2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranoside (63)
[0243] To a solution of 62 (0.35 g, 6.5 mmol) in methanol (5 mL), was added, 3-chloropropylisocyanate (0.1 g, 0.84 mmol). The reaction mixture was then left to stir at room temperature overnight. The reaction contents was evaporated to dryness and the remaining residue was dissolved in water* (˜3 mL) and loaded on to a C-18 Sep-pack column (5 g). The column was eluted** with water (50 mL) followed by 25% methanol in water (50 mL). The methanol fractions were combined and evaporated to dryness giving pure 63 (350 mg, ˜80% yield) as a white solid.
[0244] Tlc R f 0.6 (AcN:water, 3:1)
[0245] M+H found 664
[0246] HPLC R t 4.0 and 4.5 min for α/β anomers (linear gradient:
[0247] 5% AcN to 20% AcN over
[0248] 15 min, C-18 column)
[0249] 1-N-(3-acetoxythiopropyl)-1-N′-ureido-2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranoside (64)
[0250] A mixture of 63 (0.2 g, 0.30 mmol), sodium iodide (0.1 g, 0.67 mmol) and potassium thioacetate (0.2 g, 1.74 mmol) in water (10 mL) was left to stir at 80° C. for 2 h. The reaction mixture was then cooled to room temperature and concentrated to 5 ml. The concentrate was loaded on to a C-18 Sep-pack column (5 g) which was then eluted with water (100 mL) followed by 25% methanol in water (100 mL). The methanol fractions were combined and evaporated to dryness to give pure 64 (0.18 g, ˜85% yield) as a white solid.
[0251] Tlc R f 0.6 (AcN:water, 3:1)
[0252] M+H found 703
[0253] HPLC R t 5.5 and 6.0 min for α/β anomers (linear gradient:
[0254] 5% AcN to 20% AcN over
[0255] 15 min, C-18 column)
[0256] 1-N-[3-(methyl carboxymethythio)-propyl]-1-N′-ureido-2-acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranoside (65)
[0257] To a solution of sodium methoxide (14 mg, 0.26 mmol) in methanol (3 mL), was added 64 (110 mg, 0.24 mmol). The, reaction mixture was stirred at room temperature for 20 min and then methyl bromoacetate (50 mg, 0.30 mmol) was added. The resultant mixture was left to stir at room temperature for 2 h. The reaction mixture was quenched with acetic acid (200 μL) and then evaporated to dryness. The residue was dissolved in water (2 mL) and loaded on to a C-18 Sep-pack column (5 g). The column was eluted with water (50 ml) followed by 50% methanol in water (50 mL). The methanol fractions were combined and evaporated to dryness giving 65 (100.8 mg, 90% yield) as a white solid.
[0258] Tlc R f 0.65 (AcN:water, 3:1)
[0259] M+H found 734, M+Na found 755
[0260] 1-N-[3-(carboxymethylthio)-propyl]-1-N′-ureido-2acetamido-2-deoxy-4-O-[3-O-(α-D-galactopyranosyl)-β-D-galactopyranosyl]-D-glucopyranoside (66)
[0261] A solution of 65 (300 mg, 0.41 mmol) and potassium hydroxide (30 mg, 0.53 mmol) in 30% aqueous methanol (15 mL) was left to stir at room temperature for 4 h. The reaction mixture was diluted to 50 mL with methanol and then neutralised with IR-120H + resin. The suspension was then filtered and the filtrate evaporated to dryness leaving 66 (295 mg, 100% yield) as a white solid.
[0262] Tlc R f 0.30 (AcN:water, 3:1)
[0263] M+H found 719
[0264] Notes
[0265] *Milli-Q-Water was used at all times
[0266] **Flow rate was one drop/sec at all times
EXAMPLE 12
Immobilisation of Gal-α-(1-3)-Gal-β-(1-4)-GlucNAc-Linker Conjugate
[0267] Preparation of 0.3 mmol propylamido-Fmo-Ala-functionalised Silica (67)
[0268] To a mixture of FMOC-Ala (2.65 g, 8.5 mmol) and HBTU (3.23 g, 8.5 mmol) in dry DMF (20 mL), was added DIPEA (1.1 g, 8.5 mmol). The mixture was shaken for 2 min and then left to stand for 15-min. The mixture was then added to a suspension of propylamino functionalised silica* (17 g) in dry DMF (20 mL). The resultant mixture was shaken end over end for 18 h at room temperature. The mixture was filtered and the silica washed with DMF (3×100 mL) followed by methanol (3×100 mL). The resin was resuspended in a mixture of methanol (100 mL) and acetic anhydride (50 mL) and then shaken for 2 h (negative ninhydrin test after this time). The suspension was filtered and the silica was then washed with methanol (4×100 mL) and dried. The loading of FMOC-Ala was found to be 0.3 mmol per gram** of silica
[0269] Coupling of 66 to propylamido-Ala-functionalised Silica (68)
[0270] FMOC-Ala modified silica from above was cleaved by the standard method (20% piperidine in DMF, rt, 20 min) to give the corresponding free amino (˜0.3 mmol loading) functionalised silica. This was then used for the trisaccharide couplings described below.
[0271] Loading 1, ˜20 mg of F per gram of Ala-capped Silica:
[0272] To NHS (235 mg, 2.08 mmol), was added a solution of 66 (100 mg, 0.139 mmol) and EDC.HCl (2.15 g, 11.2 mmol) in water (10 mL). The resulting solution was added to a suspension of Ala-capped silica (5 g) in water (˜10 mL). The suspension was left to shake at room temperature for 3 h, at which time no trisaccharide was present in the filtrate, by tlc. The suspension was then drained, washed with water (4×50 ml), dilute sodium bicarbonate solution (3×50 ml) and again with water (3×50 ml). The silica was then resuspended in methanol/acetic anhydride (30 ml, 3:1) and left to shake for 1 h (negative ninhydrin test after this time). The suspension was then drained and the silica washed with methanol (4×50 ml) to give the trisaccharide capped silica.
[0273] Loading 2, ˜5.0 mg of 66 per gram of Ala-capped silica:
[0274] 66 (25 mg, 0.034 mmol), NHS (100 mg, 0.884 mmol), EDC.HCl (1.2 g, 6.25 mmol),
[0275] and Ala-capped silica (5 g).
[0276] Prepared as described for loading 1.
[0277] Loading 3, ˜0.5 mg of 66 Per Gram of Ala-capped Silica:
[0278] 66 (2.5 mg, 0.0034 mmol), NHS (30 mg, 0.265 mmol), EDC.HCl (130 mg, 0.677 mmol),
[0279] and Ala-capped silica (5 g).
[0280] Prepared as described for loading 1.
[0281] Coupling of 66 to hexylamino-functionalised Sepharose (EAH Sepharose 4B) (69)
[0282] Loading, ˜3.5 to 6.0 mg of 66 per mL of EAH Sepharose:
[0283] EAH Sepharose (5 mL) was washed with water (3×50 ml) and then suspended in water (5 ml). To the suspension a solution of 66 (94 mg, 0.131 mmol), EDC.HCl (1.55 g, 8.10 mmol) and NHS (290 mg, 2.57 mmol) in water (15 mL) was added. The reaction mixture was left to shake overnight at room temperature. Tlc of the filtrate showed no 66 present after this time. The reaction contents were drained and the resin was washed with water (3×50 mL). The modified Sepharose was then stored as a concentrated suspension in 5% ethanol in water (5 mL).
[0284] It will be apparent to the person skilled in the art that while the invention has been described in some detail for the purposes of clarity and understanding, various modifications and alterations to the embodiments and methods described herein may be made without departing-from the scope of the inventive concept disclosed in this specification.
[0285] References cited herein are listed on the following pages, and are incorporated herein by this reference.
REFERENCES
[0286] Augé, C. and Veyrières, A., J. C. S. Perkin I, 1979 1825-1832
[0287] Boriello, S. P., J. Med. Microb., 1990 33 207-215
[0288] Burakoff, R., Zhao, L., Celifarco, A. J. et al, Gastroenterology, 1995 109 348-354
[0289] Castex, P., Jouvert, S., Bastide, M. and Corthier, G. J. Med. Microbiol., 1994 40 102-109
[0290] Chacon-Fuertes, M. E. and Martin-Lomas, M. Carbohydrate Res., 1975 43 51-56
[0291] Eglow, R. et al. J. Clin. Invest., 1992 90 822-829
[0292] Garegg, P. J. and Oscarson, S. Carbohydrate Research, 1985 136 207-213
[0293] Good, H., Cooper, D. K. C. et al. Transplant. Proc., 1992 24 559
[0294] Ichiro, Matsuo., Hiroshi, Fujimoto., Megumi, Isomura. and Katsumi, Ajisaka., Biorganic & Medicinal Chemistry Letters, 1997 7 (3) 255-258
[0295] Krivan, H. C., Clark, G. F., Smith, D. F. and Wilkins, T. D. Infect. Immun., 1986 53 573-581
[0296] Lemieux, R. U. and Driguez, H., Journal of the American Chemical Society, 1975 97(14) 469-475
[0297] Matsuo, Ichiro; Fujimoto, Hiroshi; Isomura, Megumi and Ajisaki, Katsumi Bioorganic & Medicinal Chemistry Letters, 1997 7(3) 255-258
[0298] Milat, M-L., Zollo, P. A. and Sinay, P. Carbohydrate Research, 1982 100 263-271
[0299] Nilsson, K. G. I. Tetrahedron Letters, 1997 38 (1) 133-136
[0300] Schaubach, R., Hemberger, J. and Kinzy, W. Liebigs Ann. Chem., 1991 607-614
[0301] Simon, P. M., DDT 1 (12) December 1996
[0302] Sinaÿ, P. and Jacquinet, J. C. Tetrahedron, 1979 35 365-371
[0303] Smith, J. A. et al. J. Med. Microb., 1997 46 953-958
[0304] Sujino, Keiko., Malet, Charles., Hindsgaul, Ole. and Palcic, Monica M. Carbohydrate Research, 1998 305 483-489
[0305] Takeo, Ken'ichi and Maeda, Hideaki J. Carbohydrate Chemistry, 1988 7(2) 309-316
[0306] Tong Zhu and Geert-Jan Boons J. Chem. Soc., Perkin Trans.I, 1998 857-861
[0307] Torres, J., Jennische, E., Lange, S. and Lonnroth, I., Gut, 1990 31 781-785
[0308] Vic, G., Chuong Hao Tran, Scigelova, M. and Crout, D. H. G. Chem. Commun., 1997 169-170
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This invention relates to reagents and methods for synthesis of biologically active di- and tri-saccharides comprising α-D-Gal(1→3)-D-Gal. In particular the invention provides novel reagents, intermediates and processes for the solution or solid phase synthesis of α-D-galactopyranosyl-(1→3)-D-galactose, and derivatives thereof. In one preferred embodiments the invention provides a protected monosaccharide building block of general formula (II): in which R 3 is methoxy or methyl; R 1 is H, benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4-chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl; and R 2 is H, Fmoc, benzoyl, pivaloyl, 4-chlorobenzoyl, acetyl, chloroacetyl, levulinoyl, 4-methylbenzoyl, benzyl, 3,4-methylenedioxybenzyl, 4-methoxybenzyl, 4 -chlorobenzyl, 4-acetamidobenzyl, or 4-azidobenzyl.
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RELATED APPLICATIONS
Benefit of the filing date of U.S. provisional patent application Ser. No. 60/995,694 filed on Sep. 27, 2007 is hereby claimed, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
This disclosure relates generally to continuous motion packaging machines for packaging articles such as bottles and cans into paperboard or corrugated board cartons. More particularly, the disclosure relates to feeder assemblies of continuous motion packaging machines for picking individual paperboard or corrugated board blanks from a stack of blanks and feeding them sequentially to downstream work stations of the packaging machine to be filled with or erected around articles.
BACKGROUND
Feeders that selectively deliver articles to a work zone in a manufacturing operation are well known. For example, in the packaging industry, the packaging of food or beverage containers, such as bottles or cans, into cartons requires high speed feeders that deliver carton blanks successively to a conveyor, which then delivers the blanks to the next work station. The carton blanks generally are substantially flat, stiff paperboard or corrugated board items that previously have been fabricated from rolled stock by cutting blanks from the stock and scoring features, such as fold lines and score lines, into the blanks. Similar feeders also are employed in many other industries, such as in the magazine and publications industries, where the continuous sequential feeding of relatively flat articles from a stack or queue is required. U.S. Pat. No. 6,550,608, owned by the assignee of the present application, discloses a carton feeding system for a packaging machine that exemplifies many of the attributes mentioned above. This patent is hereby incorporated by reference in its entirety.
The term “carton feeder” commonly is used to refer to feeders that select and deliver carton blanks to a work zone in high speed continuous packaging operations. Many different types of carton feeders are used in the packaging industry, and have varying features depending upon the specific use and application requirements. It is common, however, for carton feeders to include some common structural and operation features. For example, most carton feeders used in the packaging industry are part of a carton feeding system, which can include a device for delivering stacks of carton blanks to a carton magazine. The carton magazine stores sufficient numbers of carton blanks and includes a conveyor system for conveying the blanks toward the feeder. At the feeder, individual carton blanks are sequentially selected or picked from the forwardmost end of the stack and delivered to downstream workstations of the packaging machine.
A carton magazine typically supports carton blanks on edge in a horizontal stack of hundreds or thousands of blanks, so that each carton blank rests on an edge with one face of the blank generally facing in a downstream direction toward the feeder. The magazine can include a conveyor, such as moving chain flights, on which the stack of blanks rests, and which progressively moves the carton blanks toward the feeder as the feeder progressively picks carton blanks from the forwardmost end of the stack. Rails on either side of the conveyor may maintain the stack of blanks centered or otherwise properly positioned on the conveyor. The stack of carton blanks generally is tilted, at least in the vicinity of the feeder, slightly towards the feeder to insure that the blanks maintain their upright orientations.
At a selection zone of the carton feeder, which is disposed at the most downstream end or position of the magazine, the first exposed carton in the stack contacts and is supported along its top edge by, for example, a bar or a shaft having rollers or by mechanical clips or tabs. This top edge leans against the rollers of the shaft, or against the bar or clips, depending upon the elements used, to support the upper edge portion of the stack of blanks. The bottom edge of the forwardmost blank in the magazine also contacts and is held by mechanical elements such as upstanding clips or tabs. The exposed forwardmost blank in the stack, and the stack itself, is thus supported in the proper position for selection of the forwardmost blank by the feeder. In this position, the forwardmost carton blank in the stack is urged with significant force against the rollers, bar, or clips, either by the weight of the stack of blanks, or by the force of the conveyor moving the stack forward, or both.
In one feeder system, a long horizontally oriented section of the magazine, which may support and convey thousands of carton blanks, terminates at a short downwardly oriented chute section of the magazine, sometimes referred to as the waterfall. Shorter stacks of carton blanks are conveyed from the horizontally oriented portion of the magazine into the chute, where they come to rest against the aforementioned shaft, clips, and/or tabs with the exposed face of the forwardmost blank always exposed so that it may be selected from the stack.
A common selection mechanism for a carton feeder is a vacuum system. This system includes a group of spaced vacuum cups on a pick arm assembly that are controlled to move into engagement with the exposed face of the forwardmost blank in the magazine, attach with a vacuum seal, pull the forwardmost blank from the stack, and slide the blank off of the stack for delivery to downstream stations of the packaging machine. The vacuum system includes vacuum lines, valves, and pumps that are operated in timed relationship, so that a vacuum is drawn on the face of the blank at the desired moment and held until the carton blank is released by the vacuum system. Once the forwardmost carton blank is contacted by the vacuum cups, the pick arm assembly pulls the carton blank forwardly away from the magazine a short distance until one edge of the carton blank is pulled over and away from contact with the clips or tabs holding the edge in position. The pick arm assembly then may be rotated, or otherwise moved, to slide the selected blank from beneath the shaft, clips, and/or tabs at the other edge of the blank and off of the end of the stack. The selected blank is then moved to the next work station, usually a conveyor assembly. At this position, the carton blank is released by the vacuum system and the carton is moved by the conveyor to the next area, where the carton either is folded around a group of containers, or erected, or positioned over a group of containers, depending upon the type of carton blank used. The pick arm assembly may include a plurality of vacuum cup assemblies that select carton blanks from the stack in rapid succession.
Selection and removal of the single forwardmost or first carton blank from the magazine requires that the vacuum cup attachment and forces applied to pull the carton blank forward and then slide it from beneath the clips and off of the stack are sufficient to overcome the mechanical forces that hold the carton blank in the magazine. Usually these forces include friction that is induced by the weight of the carton stack and/or the magazine chain conveyor pressing the forwardmost carton against the rollers and/or clips at the end of the magazine. If the vacuum is insufficient or the pulling forces are insufficient to overcome this friction, the carton blank will not be selected correctly. For The force of the vacuum attaching the vacuum cups to the face of the forwardmost carton is strongest in a direction perpendicular to the face of the blank; that is, along the axis of the vacuum cup. Conversely, the force is weakest in a direction parallel to the face of the blank or transverse to the axis of the vacuum cup. As a consequence, one edge of the forwardmost blank often is pulled easily over and away from the clips holding it in place at the end of the magazine. However, when the pick arm assembly rotates the vacuum cups to slide the blank off of the stack, the friction between the blank and the bar and/or clips holding the opposite edge portion of the blank can be sufficiently great to overcome the force of the vacuum. This can cause the vacuum cups to slide or slip off the face of the blank, particularly during high speed operation of the feeder. The result can be that a carton blank is not picked, or selected, from the magazine, or that a carton blank is only partially separated from the magazine, resulting in a system jamb and an operational stoppage.
Therefore, there is an advantage in reducing the frictional forces that are exerted on the forwardmost carton blank in a magazine in these types of feeder systems, so that the gripping force of the vacuum cups needed to select the first carton reliably also is reduced and/or controlled. Prior feeder systems have addressed this issue by using small spaced clips instead of bars at the end of the magazine to hold the forwardmost carton blank at its edges, thus reducing the contact area between the carton edge and the mechanical element. Other methods and elements used to reduce the frictional forces between carton blanks and the mechanical structures holding them in place at the end of the magazine include freewheeling rollers placed along a support shaft instead of clips or bars. Sometimes the rollers themselves can be positively driven by a shaft, in order to reduce further the force needed to select the first carton. Another prior feeder system includes a movable support bar synchronized with the pick arm and suction cups such that just before a blank is to be slid off the stack at the end of the magazine, the support bar moves quickly a short distance toward the stack of blanks and back again to toss the stack briefly backward a short distance. The forwardmost blank is then slid from beneath the support bar as the stack falls back toward the support bar, a time when friction allegedly is reduced.
A need exists for an improved system for insuring that the forwardmost carton blank of a stack in the magazine is reliably selected and removed from the stack, particularly during high speed operation of the packaging machine. It is to the provision of such a system that the present invention is primarily directed.
SUMMARY
Briefly described, the present invention, in one embodiment thereof, includes a carton feeder and carton magazine assembly having, at the downstream end of the magazine, a support shaft assembly. The support shaft assembly includes a driven eccentrically rotating support shaft against which the forwardmost blank in a stack of carton blanks rests and by which the stack is supported. Several freewheeling bushings or rollers preferably are mounted at spaced intervals along the support shaft. The support shaft rotates relatively rapidly and oscillates, simultaneously, against the forwardmost blank of the carton stack. This motion of the support shaft maintains the forwardmost carton blank spaced slightly from and out of contact with the rollers of the support shaft for the great majority of each revolution of the support shaft. During this time, there is virtually no friction between the forwardmost blank and the rollers of the support shaft. Thus, the average frictional force between the blank and the rollers of the support shaft is significantly reduced. The eccentrically rotating motion of the support shaft against the forwardmost blank also vibrates and “shakes down” the stack of blanks, reducing friction between successive blanks in the stack and helping to keep the blanks aligned. As a result, significantly less force is required for suction cups of the pick arm assembly to slide the forwardmost carton blank from beneath the support shaft and off of the stack. Consequently, mispicks of carton blanks and the resulting machine jambs and down time are virtually eliminated.
The support shaft assembly includes the generally cylindrical support shaft body with spaced freewheeling rollers that extends across the downstream end of the carton magazine to support a stack of carton blanks as described. Cylindrical bosses, smaller in diameter than the support shaft body, project axially from each end of the support shaft body. The cylindrical bosses are axially aligned with each other, but their axes are offset a small distance from the axis of the support shaft body. The cylindrical bosses are rotatably journaled by bearing assemblies that are supported by the frame of the carton magazine. One of the cylindrical bosses is driven by an electric induction motor that is controlled by a machine controller. Thus, upon activation of the motor, it will be seen that the support shaft body and its rollers are caused to rotate eccentrically and not concentrically about the axes of the cylindrical bosses, and thus the support shaft oscillates as it rotates. The support shaft body has milled balancing kerfs at various locations along its “high side” to insure that the support shaft is balanced as it rotates eccentrically and does not shake in its bearings because of the eccentric nature of its rotation.
The eccentric rotation and consequent oscillation of the support shaft and its rollers causes the stack of carton blanks to move rearwardly, that is, away from the carton feeder, a short distance as the high side of the support shaft body and the freewheeling rollers thereon move toward the stack during each eccentric revolution. When the high side of the support shaft begins to rotate away from the stack, the rollers move out of contact with the forwardmost carton blank and the stack begins to fall back toward the support shaft under the weight of the stack. However, if the support shaft is rotated at a sufficiently high rate such as, for example, 1500 revolutions per minute, the stack will not have time to fall back into contact with the rollers of the support shaft before the next rotational cycle when it is again urged rearwardly by the support shaft rollers. As a result, the forwardmost carton blank of the stack is out of contact with the rollers of the support shaft for most of the time, which can be as much as ninety or ninety-five percent of the time. Only when the “high side” of the support shaft rotates toward the stack do its rollers contact the forwardmost blank for a short time to nudge the stack rearwardly once again.
When suction cups of the feeder assembly grasp the forwardmost carton blank of the stack, pull its bottom edge from behind the upstanding support tabs, and begin to slide the blank from beneath the support shaft and off of the stack, the average friction between the face of the blank and the support shaft, and the friction between successive blanks in the stack, is significantly reduced compared to that present with prior art support clips and bars. Thus, the forwardmost blank of the stack slides easily from beneath the support shaft and off of the stack and the suction cups do not tend to slip off of the face of the blank due to shear forces generated in overcoming friction, as has been common in the past. In one embodiment, the support shaft is rotated in the same direction that the carton blanks are to be slid off of the stack, which imparts to the forwardmost carton a slight force in that direction. This slight force assists the suction cups of the pick arm assembly to slide blanks from the end of the stack and thus further insures against machine jambs and down time.
Thus, a carton feeder and magazine assembly is now provided that successfully addresses shortcomings of the prior art. The assembly will be better understood upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, looking downstream toward the feeder assembly, of the end portion of a carton magazine illustrating aspects of the invention in one preferred embodiment thereof.
FIG. 2 is a perspective view, looking upstream, of the end portion of a carton magazine illustrating aspects of the invention.
FIG. 3 is a side elevational view, with end view projection, showing the support shaft, rollers, and cylindrical bosses of the support shaft assembly according to aspects of the invention.
FIGS. 4 a - 4 d illustrate, sequentially, a carton blank being picked or selected from the end of a stack of blanks in a system wherein the present invention is employed.
DETAILED DESCRIPTION
Referring now in more detail to the drawing figures, wherein like reference numerals indicate like parts throughout the several views, FIG. 1 is a perspective view of a carton feeder and magazine system according to the invention looking downstream from the carton magazine toward the feeder assembly. The feeder assembly, generally indicated at 11 , is similar in construction and operation to that disclosed in the fully incorporated U.S. Pat. No. 6,550,608, owned by the assignee of the present invention. As such, the feeder assembly itself need not be described here in great detail. In general, however, the feeder assembly 11 is located at the end 16 of the carton magazine 12 . The feeder assembly is configured and operates to feed carton blanks from the end of a stack of blanks supported on the magazine 12 into an overlying relationship with a series or groups of articles, such as beverage cans or bottles, passing through an article packaging machine, where the articles are packaged into cartons. The feeder assembly 11 is a rotary type carton feeder having a series of carton engaging assemblies, each including a vacuum cup bar 21 on which is mounted a plurality of spaced apart vacuum cups 22 connected to a vacuum system.
The carton magazine 12 has a generally horizontal section 13 with rails and conveyor chain flights for supporting a stack of hundreds or thousands of carton blanks resting on edge on the magazine. The chain flights move in a downstream direction to convey the stack of cartons on the magazine toward the carton feeder assembly. A downwardly angled chute section of the magazine, sometimes referred to as the waterfall, is disposed at the downstream end of the magazine adjacent to the feeder assembly 11 . The chute section of the magazine has a discharge end, generally indicated at 16 , adjacent the feeder assembly where the forwardmost carton blank of a stack of blanks in the magazine is held in position with its face exposed to the feeder assembly for selection.
An array of upstanding tabs or clips 17 are disposed along the bottom edge of the discharge end 16 of the magazine and a support shaft 18 , constructed and operating according to the present invention, extends across the discharge end near its upper extent. As a stack of carton blanks is progressively conveyed toward the discharge end 16 of the magazine, the bottom edge of the forwardmost blank of the stack is engaged by the upstanding tabs 17 and the upper portion of the forwardmost blank of the stack leans against and is supported by the support shaft 18 . The weight of the stack of blanks is thus supported by the upstanding tabs 17 and the support shaft 18 with the forwardmost carton blank of the stack positioned with its surface facing and exposed to the carton feeder 11 .
The carton feeder 11 sequentially selects or picks the exposed forwardmost carton blanks from the end of the stack on the magazine and delivers them, in rapid succession, to downstream workstations of the packaging machine. More specifically, a vacuum cup bar 21 of the feeder assembly is rotated toward the forwardmost blank in the stack until the vacuum cups 22 of the bar 21 engage the exposed surface of the forwardmost blank near its bottom edge. The vacuum system applies a vacuum to the vacuum cups 22 , which attaches the vacuum cups to the surface of the forwardmost blank. The vacuum cups 22 are then moved back a short distance in a direction generally perpendicular to the face of the blank, which pulls the bottom edge of the forwardmost blank from behind the upstanding clips 17 to free the bottom edge of the blank. With the bottom edge of the forwardmost blank freed from the stack, the feeder assembly 11 rotates the vacuum bar 21 and its vacuum cups 22 in a downward direction, which pulls the forwardmost blank downwardly to slide it from beneath the support shaft 18 and off of the stack to be delivered to downstream workstations of the packaging machine. This process is repeated at relatively high speeds during operation of the packaging machine to select and feed carton blanks from a stack in the magazine in rapid succession to downstream workstations, where they are erected around or otherwise packaged with articles such as beverage cans or bottles.
According to the present invention, the support shaft 18 against which the forwardmost blank of the stack rests, comprises an elongated generally cylindrical body 26 that extends across the discharge end 16 of the magazine 12 , and that has an axis. A series of bushings or rollers are mounted at spaced intervals along the length of the body 26 and each roller is freely rotatable about the body 26 and thus may be said to be freewheeling. A cylindrical boss 27 projects from each end of the body 26 and each boss 27 is rotatably journaled by a bearing 28 mounted in a support 29 . The boss on the right hand side of the support shaft 18 in FIG. 1 is coupled to an induction motor 31 that, when activated, rotates the boss and thus rotates the support shaft 18 .
Each of the cylindrical bosses 27 at the ends of the support shaft body 26 is smaller in diameter than the support shaft body 26 and has an axis that is offset a predetermined relatively small distance from the axis of the support shaft body, but that is aligned with the axis of the cylindrical boss at the other end of the support shaft body. Thus, when the support shaft 18 is rotated by the induction motor 31 , the support shaft does not rotate concentrically about its axis, but rather rotates eccentrically about the axes of the cylindrical bosses. The surface of the support shaft body 26 and the surfaces of the freewheeling rollers 20 thus oscillate toward and away from a stack of carton blanks on the magazine as a result of the rotation of the support shaft.
A series of milled balancing kerfs 32 are formed along the length of the support shaft body 26 on its “high side” in order to remove a sufficient amount of material to balance the support shaft as it rotates eccentrically. The determination of how much material and weight to remove from the shaft body 26 can be made with any of numerous commercially available computer assisted drawing (CAD) software programs well known to those of skill in the art. The balancing of the support shaft is important since, in operation, it is rotated at a high rate such as, for instance, 1500 revolutions per minute. Without proper balancing, the support shaft 18 would tend to shake or vibrate violently within its bearings 28 .
FIG. 2 is a view of the discharge end 16 of the carton magazine looking upstream from the perspective of the feeder assembly. The feeder assembly and its various components are omitted in FIG. 2 for clarity. A stack of carton blanks 40 is disposed in the carton magazine 12 ( FIG. 1 ) with a forwardmost carton blank 41 having is face exposed at the end 16 of the magazine in position to be selected by the vacuum cups of the feeder assembly. While the carton blanks in this figure are illustrated as simple rectangular blanks for clarity, it will be understood by those of skill in the art that, in most applications, the blanks will be cut and scored to form various flaps, panels, tabs, and the like appropriate for packaging articles such as beverage cans or bottles. The carton blanks typically are made of paperboard, but also may be made of corrugated board or other carton material.
The bottom edge 42 of the forwardmost carton blank 41 is located behind and is held in place by the upstanding tabs 17 at the bottom of the discharge end of the magazine. The tabs 17 may take on a variety of configurations such as, for instance, upstanding tabs formed on a bar as illustrated in FIG. 2 , or separate vertical bars that project slightly upwardly into the end of the magazine to engage and capture the bottom edge 42 of the forwardmost carton blank. In any event, the upstanding tabs 17 engage and arrest the forward movement of the bottom edge 42 of the forwardmost carton blank 41 and thereby hold the bottom edge of the stack 40 on the magazine bed. As the chain flights of the magazine move in a downstream direction, the bottoms of the carton blanks are urged together against the upstanding tabs 17 to keep the blanks of the stack tightly packed.
The support shaft 18 , embodying principles of this invention, extends across the discharge end 16 of the carton magazine 12 a predetermined distance below the top edges of the carton blanks of the stack 40 . The stack of carton blanks lean forward in the waterfall portion of the magazine so that the exposed face of the forwardmost carton blank 41 rests against the support shaft 18 . Thus, the upper portion of the stack 40 is supported against the support shaft with the face of the forwardmost carton blank exposed to the feeder assembly in position to be selected from the end of the stack.
The axially displaced cylindrical bosses 27 ( FIG. 1 ) on the ends of the body 26 of the support shaft are rotatably journaled by respective bearings 28 that are mounted within structural supports 29 of the magazine. The cylindrical boss on the right hand side in FIG. 2 extends through its bearing 28 and is operatively coupled to induction motor 31 my means of a coupler sleeve 33 . Freewheeling rollers or bushings 20 are rotatably mounted on the body 26 of the support shaft at spaced intervals therealong. As detailed below, the freewheeling rollers are held in place by appropriate clips secured to the body 26 at the ends of the rollers. These clips may be spring clips secured within annular grooves of the body 26 , or any other type of clip that maintains the rollers in position along the body 26 and yet allows the rollers to rotate freely about the support shaft body. Balancing kerfs 32 are milled at spaced intervals along the support shaft body on its “high side;” that is, on the side opposite to the direction in which the axes of the bosses 27 are offset from the axis of the support shaft body. The depth and size of the balancing kerfs are predetermined to balance the support shaft 18 as it rotates eccentrically about the axes of the cylindrical bosses and thus to prevent vibration and shaking that might otherwise occur.
During a packaging operation, the induction motor 31 is activated to rotate the support shaft 18 at a relatively high rate, preferably, but not necessarily, in the direction of arrow 35 . While a wide variety of rotation rates may be selected, it has been found that a rotation rate of between 1000 and 2000 revolutions per minute (rpm), and preferably about 1500 rpm functions well and represents the best mode of carrying out the invention. The rotation of the support shaft by the motor 31 causes the body of the support shaft, and thus the freewheeling rollers, to move eccentrically or, in other words, to oscillate rapidly back and forth toward and away from the forwardmost carton blank of the stack. As this occurs, the high sides of the freewheeling rollers 20 repeatedly engage the face of the forwardmost blank 41 . This has the effect of pushing the upper edge portion of the stack of blanks 40 in an upstream direction just slightly. As the high sides of the rollers rotate past the forwardmost blank, the stack begins to fall back toward the support shaft under the influence of gravity. However, before the stack can fall back into engagement with the support shaft, the high side again rotates around to engage the stack and push it, once again, slightly upstream. As a result of this action, the face of the forwardmost blank 41 is out of engagement with the freewheeling rollers 20 for a great majority of the time and is only in contact with the rollers briefly as their high sides rotate around to engage and push the stack slightly backward. It has been estimated that the face of the forwardmost blank 41 remains out of contact with the rollers for as much as ninety percent (90%) or more of the time, although this figure might be more or less depending upon numerous factors such as rotation rate of the support shaft, the weight of the stack, etc.
As a consequence of the forgoing action, the average friction between the face of the forwardmost blank 41 and the support shaft 18 is greatly reduced relative to the friction encountered with prior art tabs, clips, or bars. Furthermore, the freewheeling rollers 20 , since they rotate in a downward direction when impacting the forwardmost blank 41 , impart a slight downward force to the forwardmost blank due to momentum and rotational resistance of the rollers themselves. This helps to keep the bottom edge of the forwardmost blank properly aligned and seated against the upstanding tabs 17 before it is selected. Furthermore, as detailed below, the slight downward force imparted to the forwardmost blank assists the vacuum cups to slide the forwardmost blank downwardly from beneath the support shaft and off of the stack 40 when the forwardmost blank is selected. Finally, it has been found that the vibration imparted to the stack 40 by the eccentrically rotating support shaft 18 helps to “shake down” the stack, eliminating air between the blanks, keeping the blanks properly aligned, and generally improving the efficiency of the selection operation.
FIG. 3 illustrates a preferred construction of the support shaft in greater detail. The relative sizes of some of the components shown in FIG. 3 have been exaggerated for clarity of description. For example, the diameter of the cylindrical boss 27 relative to that of the support shaft body 26 has been exaggerated, as has the offset between the axis of the cylindrical boss and the axis of the support shaft body. In reality, the diameters of the support shaft body and the cylindrical boss are closer to the same, and the offset of the axes is small, 1/32 of an inch in the preferred embodiment, but large enough to realize the advantages of the present invention.
The support shaft 18 has an elongated generally cylindrical body 26 with an axis 47 and ends 24 , only one of which is visible in FIG. 3 . A cylindrical boss 27 projects from the end 25 of the body 26 and has an axis 46 . It will be understood that a similar cylindrical boss projects from the opposite end of the body 26 and also has an axis. The axis 46 of the cylindrical boss 27 is radially offset from the axis 47 of the support shaft body 26 . In the illustrated embodiment, the offset is relatively small, 1/32 of an inch; however, this particular offset is not a limitation of the invention and other offsets may be selected by skilled artisans. Further, the cylindrical boss on the opposite end of the body 26 is offset by the same amount and in the same radial direction relative to the axis 47 of the body 26 . In other words, the axes of the cylindrical bosses at each end of the support shaft body 26 are offset equally and are coextensive with each other.
With the just described configuration, it will be seen that when the cylindrical bosses are journaled within their bearings as described above and one is rotated by induction motor 31 , the body 26 rotates eccentrically about the coextensive axes of the cylindrical bosses. Thus, the surface of the body 26 wobbles or follows an oscillating path as a result of its rotation. Balancing kerfs 32 are milled at spaced intervals along the high side of the support shaft body 26 ; that is, along the side radially opposite to the direction in which the axes of the cylindrical bosses are offset from the axis of the body 26 . The amount of material removed from the body in the balancing kerfs is predetermined so that the eccentrically rotating support shaft is balanced and does not shake as it rotates at relatively high rates. Freewheeling rollers 20 are rotatably mounted on the support shaft body 26 at spaced intervals, preferably in between the balancing kerfs. The rollers, which may be metal or plastic bushings, are retained in position on the body by appropriate retainer clips, such as ring clips 15 in the illustrated embodiment.
FIGS. 4 a through 4 d illustrate sequentially the operation of the support shaft 18 of this invention as forwardmost carton blanks are selected and removed by the feeder assembly from the stack for delivery to downstream stations of a packaging machine. FIG. 4 a shows a stack 40 of carton blanks at the end of magazine 12 with the forwardmost blank 41 of the stack being exposed for selection and being supported along its bottom edge by upstanding tabs 17 . Support bar 18 , carrying freewheeling rollers 20 , extends across the end of the magazine spaced a predetermined distance down from the top edge of the forwardmost carton blank 41 . The support shaft 18 is being rotated by motor 31 (not shown) eccentrically in direction 35 and, as a result of its rotation, the rollers 20 disposed about the body of the support shaft oscillate rapidly back and forth toward and away from the forwardmost blank 41 of the stack 40 . As described above, this causes the surface of the forwardmost blank to be out of contact with the rollers 20 for a great majority of the time. Vacuum cup 22 of the feeder assembly is shown approaching the forwardmost blank 41 for selecting the forwardmost blank and removing it from the front of the stack.
In FIG. 4 b , the vacuum cup 22 rotates into engagement with the face of the forwardmost blank 41 , in this case near its bottom edge portion, and the controller of the packaging machine applies an appropriate vacuum to cause the suction cup to stick or adhere to the face of the forwardmost blank. The support shaft 18 continued to rotate eccentrically as described, reducing greatly the friction between the face of the forwardmost blank and the support shaft.
In FIG. 4 c , the feeder assembly next withdraws the vacuum cup a short distance in the direction of arrow 50 substantially perpendicular to the face of the forwardmost blank and along the axis of the vacuum cup. This, in turn, pulls the bottom edge 42 of the forwardmost blank from behind the upstanding tabs 17 that previously held the bottom edge in place. The next blank of the stack falls in behind the clips 17 . The support shaft continues to rotate so that the friction between the surface of the forwardmost blank 41 and the support shaft continues to be minimized.
In FIG. 4 d , the feeder assembly rotates the vacuum cup downwardly with a vacuum still applied to the vacuum cup by the vacuum system. In prior art systems, this is the point at which the vacuum cups sometimes would slip off of the face of the forwardmost blank due to the shear forces on the cup caused by overcoming friction between the blank and the support structure (clips, tabs, or bars) supporting the top portion of the blank. However, with the present invention, the friction between the support shaft 18 and the face of the forwardmost blank 41 is minimized. In fact, it has been found that, with the support shaft and its rollers rotating in direction 35 , the rollers impacting the face of the blank impart a small downward force to the blank. Accordingly, the support shaft of this invention actually assist the vacuum cups to slide the forwardmost blank off of the stack and from beneath the support shaft. As a result, instances of machine jams as a result of the vacuum cups slipping off of blanks during a packaging operation are greatly reduced or eliminated.
The sequence illustrated in FIGS. 4 a through 4 d is repeated in rapid succession to select carton blanks from the stack and feed or deliver them to downstream workstations of the packaging machine, as described in detail in the incorporated U.S. Pat. No. 6,550,608.
The invention has been described herein in terms of preferred embodiments and methodologies considered by the inventors to represent the best mode of carrying out the invention. It will be clear to skilled artisans, however, that many modifications might be made to the illustrated embodiments within the scope of the invention. For example, while an eccentrically rotating cylindrical body has been illustrated and described herein, equivalent results may be obtained by, for instance, a concentrically rotating body having a slightly oval or oblong cross section; although, in such a configuration, it is believed that freewheeling rollers would be difficult to implement successfully. In another example, a concentrically rotating cylindrical body might be provided with a ridge, bumps, or rollers along one side that engage the surface of the forwardmost blank as the body is rotated. Thus, eccentricity of rotation is not necessarily are requirement of the present invention. Further, the support shaft assembly and methodology has been illustrated herein within the context and used with a particular type of rotary feeder assembly. It should be understood that the invention certainly is not limited to a rotary feeder, or to any particular type of feeder, or to feeders with vacuum cups used to select carton blanks. For example, the support shaft and methodology of the invention is equally applicable to a segment wheel type feeder assembly or, indeed, any feeder assembly where a stack of carton blanks is supported at an end from which blanks are selected or picked. More broadly, the invention applies to industries other than the packaging industry in any situation where a stack of substantially flat items needs to be supported with reduced friction between the support and the items. Finally, while an electric induction motor has been described as the preferred means of driving the pusher assembly, it will be understood that any appropriate drive, such as, for instance, a pneumatic or hydraulic drive, or a drive mechanism linked to another shaft, my be substituted with equivalent results. These and other additions, deletions, and modifications might well be made to the embodiments illustrated herein without departing from the spirit and scope of the invention, which is defined only by the claims hereof.
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A carton feeder assembly is disclosed for selecting or picking carton blanks from the end of a stack of blanks in a magazine. The assembly includes a magazine and conveyor for moving stacks of carton blanks toward a carton feeder assembly. A support shaft assembly is disposed at the downstream end of the magazine and includes a support shaft against which the forwardmost carton blank in the stack leans and rests to support the stack of carton blanks. The support shaft is eccentrically rotatably mounted and driven by a motor so that the support shaft oscillates rapidly as it is rotated. This motion of the support shaft keeps the forwardmost blank of the stack spaced slightly from and out of contact with the support shaft for a significant majority of the time, thus reducing substantially the average friction between the forwardmost blank and the support shaft. Thus, the forwardmost blank can gripped with suction cups of the feeder assembly, which can then be moved to slide the forwardmost blank from beneath the support shaft and off of the stack of blanks with very little frictional resistance. The suction cups thus stay attached to the blank and do not tend to slide off due to shear forces developed in overcoming frictional resistance.
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FIELD OF THE INVENTION
The invention relates to a valve assembly for pressure control of a pressure medium from a pressure medium pump to at least one first consumer, comprising a pilot-operated pressure control valve. The valve includes a main piston pressurized by the pressure medium and a pilot piston. A pressure chamber between a back of the main piston and the pilot piston can be relieved.
BACKGROUND OF THE INVENTION
Typically, pressure control valves are used if the travel speed of a hydraulic cylinder or the speed of a hydraulic motor is to be kept constant independently of the pressure difference prevailing on a flow valve, independently of the temperature or viscosity of a pressure medium used for this purpose and independently of the load to be moved. The pressure medium flow that has not been routed through the pressure control valve is drained via a pressure limiting valve for a pressure medium pump with relatively great losses in performance and pressure.
To minimize such performance losses, linking a pressure control valve that works as a pressure compensator to a load sensor on a consumer, for example, of a hydraulic cylinder, such that the LS (load sensing) pressure from the load sensor of the consumer prevails in a pressure chamber downstream of the pilot piston, is known. In particular, the pump pressure can be compared essentially to the spring pretensioning on the control piston plus the pressure on the consumer (LS). When the consumer is in the off-position, the pressure medium can be drained with less energy loss than in use with a pressure limiting valve. The performance loss of these known pilot-operated pressure control valves with a pressure compensator function, however, cannot be completely avoided.
DE 103 22 585 A1 describes, for example, a valve assembly for pressure control of a pressure medium from a pressure medium pump to a consumer, wherein a main control valve can be able to be hydraulically actuated by a pilot valve. In particular, the document describes a valve module system with at least one valve housing that, on its opposite ends both to the inside and to the outside on the periphery and in the housing interior, has standardized nominal sizes for mounting of other valve components. Such valve components can be a valve piston, an energy store, a pilot valve, and at least one fluid port for securing the valve assembly designed as a screw-in cartridge in the vicinity.
DE 10 2005 059 240 A1 shows and describes a hydrostatic drive system with a variable-stroke pressure medium pump that supplies a consumer with pressure medium via control valves. In idle operation of the hydrostatic drive system in which the control valves are not actuated, a pressure compensator used as a circulation device is set to a minimum control pressure difference. The pressure medium pump is set to a minimum delivery volume, with the pressure medium flow that comes from the pressure medium pump flowing via the pressure compensator to a pressure medium tank with low power loss.
The hydraulic drive system has a complex structure and does not have minimized pressure losses.
DE 689 08 317 T2 describes a pressure control valve whose main valve is pilot-operated by a pilot valve located in a common valve housing.
SUMMARY OF THE INVENTION
An object of the invention is to provide an improved valve assembly for pressure control of a pressure medium that enables further minimization of the pressure loss when a consumer is not connected.
This object is basically achieved with a valve assembly for pressure control of a pressure medium from a pressure medium pump to a consumer and includes a pilot-operated pressure control valve with a spring-loaded main piston. A pilot piston that controls a valve seat for a fluid-carrying connection on a rear pressure chamber of the main piston is a component of the pressure control valve. The pressure chamber of the main piston on the piston back is pressurized via a first throttle in the main piston by the pump pressure so that the circulating pressure compensator formed in this way allows a comparison between the pump pressure and the pressure on the load sensor plus the spring pretensioning of the main control piston and of the pilot piston. A pressure of the pressure medium pump that is higher by the respective set spring tensions than the pressure on the load sensor of the consumer is established. Furthermore, according to the invention, a relief valve is provided for the space between the main piston and the pilot piston.
The relief valve is formed as a gate valve or seat valve, with a valve element of the relief valve being arranged such that at zero pressure of the load sensor, corresponding to the consumer in the off position, a flow of the pressure medium from the space between the main piston and pilot piston to a pressure medium vessel, tank, or into the LS line is enabled. During operation in unpressurized circulation, the relief valve is opened, and likewise the main valve can be opened. The pilot valve is closed in this case.
If the pressure on the load sensor rises above a set value at the relief valve, the relief valve closes the bypass formed in this way and enables a load sensing-controlled function of the pressure control valve according to the known prior art. The main valve and pilot valve are in the control position here.
The relief valve according to the invention thus enables a significant reduction of the pressure losses of the valve assembly compared to the known circuits of circulating pressure compensators.
In a travel position of the valve element of the relief valve, the pressure medium coming from the pressure medium port of the pressure control valve can be drained away via a first throttle and via the relief valve to the pressure medium tank. The pressure medium can be routed to the relief valve via a longitudinal channel between the pressure chamber of the main piston and another second pressure chamber that can be traversed by the pilot piston.
In one especially preferred exemplary embodiment of the valve assembly, the longitudinal channel has another second throttle. The second throttle then divides the longitudinal channel into two channel sections. A first channel section is assigned to the pressure chamber of the main piston in this case. A second channel section of the longitudinal channel is assigned fluidically to the second pressure chamber, which second pressure chamber can be traversed by the pilot piston. The second throttle can be used as a damping element for the relief valve. In one especially preferred exemplary embodiment, the relief valve is located in the housing of the pressure control valve. The valve element of the relief valve in this case is guided to be able to move axially in a longitudinal bore. A fluid-carrying connection to one channel section of the longitudinal channel or the other in at least one travel position of the valve element is established via at least one annular recess in the housing of the pressure control valve or in the valve element of the relief valve.
The valve element of the relief valve is preferably preloaded using an energy store (compression spring) in the direction of the second pressure chamber that can be traversed by the pilot piston. The pilot piston of the pilot valve can actuate a fluid-carrying connection between a load sensor LS and one free side of the valve element of the relief valve, which side is opposite the energy store. In partial load or full load operation of a consumer controlled using the pressure control valve and at a corresponding LS pressure, the valve element of the relief valve blocks a fluid-carrying connection between the pressure chamber of the main piston and the pressure medium tank. However, when the consumer is in the off position and at an LS pressure that approaches zero, the valve element of the relief valve conversely under the action of the energy store is moved into a travel position in which a direct fluid-carrying connection between the pressure chamber of the main piston is opened via the relief valve to the pressure medium tank. In this case, the pressure medium flows via the annular recess on the relief valve.
In a valve solution in which the annular recess in the housing or in the valve element discharges into the second channel section of the longitudinal channel between the pressure control valve and the pilot valve, the annular recess is linked at the second pressure chamber of the pilot piston or of the pressure chamber that can be traversed by the pilot piston to carry fluid.
Instead of an integrated construction of the pilot valve, main valve, and relief valve, a decentralized individual arrangement of the indicated valves into an overall valve assembly is possible. The relief valve can be located in a parallel arrangement to the pressure control valve between a pressure medium pump and the pressure medium tank. The relief valve can be pilot-operated directly. Alternatively and advantageously, the relief valve can be designed as an electrically actuatable 2/2-way valve that is actuated, for example, by a control and/or regulating device processing pressure signals of a pressure sensor.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1 a is a schematic diagram of a valve assembly with a side elevational view in section, not to scale, of a pressure control valve assembly according to an exemplary embodiment of the invention with a relief valve in the opened operating position in a pressure control valve with linkage to a constant flow-pressure medium pump and to two consumers;
FIG. 1 b is an enlarged side elevational view in section of detail I in FIG. 1 a;
FIG. 1 c is a schematic side elevational view in section, not to scale, of the pressure control valve assembly of FIG. 1 with the relief valve in the control position of the main valve and of the pilot valve with the closed operating position of the relief valve;
FIG. 1 d is an enlarged side elevational view in section of detail I in FIG. 1 c;
FIG. 1 e is a side elevational view in section of a pressure control valve according to a second exemplary embodiment of the invention with a relief valve;
FIG. 1 f is a side elevational view in section of detail I in FIG. 1 e;
FIG. 2 is a hydraulic circuit diagram of the valve assembly according to a third exemplary embodiment of the invention;
FIG. 3 is a hydraulic circuit diagram of a valve assembly with a connection of a relief valve downstream of a first throttle and upstream of a second throttle between the main control valve and the pilot valve of the pressure control valve according to a fourth exemplary embodiment of the invention;
FIG. 4 is a hydraulic circuit diagram of a valve assembly according to a fifth exemplary embodiment of the invention; and
FIG. 5 is a hydraulic circuit diagram of a valve assembly according to a sixth exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 a shows a closed hydraulic circuit of a valve assembly 1 , comprising a constant pressure medium delivery pump 3 for supplying a consumer 4 with pressure medium 2 . The consumer 4 is shown as a hydraulic motor with two possible flow directions. The consumer 4 is actuated via an electrically actuated 4/3-way valve 19 . The pressure prevailing on the consumer 4 is signaled to an LS line by a selector valve 18 . A 2/2-way valve 20 with a pressure limiting function in the opened operating position is located upstream of this valve control.
In the exemplary embodiment of a hydraulic system shown in FIG. 1 a , two consumers 4 , each with identical valve control engineering, are connected in parallel and can be supplied by a constant pressure medium delivery pump 3 . The manner of operation of the valve control block formed in this way for the consumers 4 will not be detailed here since it is adequately known from the prior art. The hydraulic system calls for a constant pressure medium delivery pump 3 as a more economical alternative to a variable delivery pump, but requires a control of its volumetric flow to be able to operate the consumer with a definable speed. A flow valve, especially a pressure control valve, is required, constituting altogether a simpler overall solution that is more economical than the one that results when using a variable delivery pump.
As FIG. 1 a further shows, to display a load-independent constant speed of the two consumers 4 , a single pressure control valve 5 with piloting, while taking into consideration a load sensor LS provided for the two consumers 4 . The load sensor LS proceeds first separately on each selector valve 18 for each consumer 4 to display or indicate the consumer in the off position and in the operating position. Upstream of each selector valve 18 one check valve 22 at a time is connected to the hydraulic circuit into the control lines that can also be referred to as “load sensing” control lines 21 . Each check valve 22 has the same set opening pressure and opens in the direction of the pressure control valve 5 , especially in the direction to its load sensing port LS. This parallel connection of the control lines 21 with respect to the pressure control valve 5 enables a comparison of the two load pressures on the consumers 4 , with the higher of the two possible load pressures being taken into account. In the pressure control valve 5 , also shown in FIG. 1 c and in another embodiment in FIG. 1 e , a valve assembly 1 is provided with an additional relief valve 10 , which additional relief valve in this respect is an important component of the solution according to the invention.
The operating principle of the pressure control valve 5 corresponds to a pilot-operated circulating pressure compensator 17 , with three valves that are different in terms of operation being combined in a common housing 12 . The fundamental functional linkage of the valves is also shown in a schematic circuit diagram in a detached construction. In particular, the three valves are the following:
a main valve 23 with main piston 6 and a compression spring 24 that preloads it, a pilot valve 25 with a pilot piston 7 and a compression spring 26 that preloads it, and a relief valve 10 made as a miniature valve with a valve element 27 or relief valve piston and an energy store 28 that keeps it in the direction of a closed position.
In the cartridge-shaped housing 12 of the pressure control valve 5 , which housing is designed as a cartridge valve, in a main valve control section, the main piston 6 is guided to move longitudinally in a bore 29 of the housing 12 in a main valve control section. The main piston 6 actuates or operates in a pressure medium inlet 30 , by opening and blocking the fluid communication between inlet 30 and port 31 , extending centrally and axially into the housing 12 . A possible fluid-carrying connection can be established to a pressure medium port 31 extending radially out of the housing 12 , optionally including several radially arranged passage bores in the housing 12 and able to be connected to a pressure medium tank 11 from which the pressure medium pump 3 takes pressure medium for the hydraulic circuit.
The main valve 23 is designed with reference to its effective cross section such that the entire volumetric flow of the pressure medium 2 can be conveyed to the pressure medium tank 11 by the constant pressure medium delivery pump 3 . In the main piston's 6 piston bottom, a first throttle 13 has the form of a through opening or bore with a definable diameter. This throttle 13 enables the pressure on the piston back 9 of the main piston 6 to be signaled, which pressure is prevailing on the pump side. The main piston 6 is designed essentially as a cylindrical sleeve with a piston bottom as fluid separation so that on the back 9 of the piston a cup-shaped pressure chamber 8 is formed and is used for centering and accommodating the compression spring 24 and for accommodating the pressure medium 2 . In the axial direction of the pressure control valve 5 , a bore 32 with a diameter of roughly ⅕ of the main piston 6 in the valve housing 12 is made in the center. The bore 32 in roughly its axial center has another second throttle 14 . The second throttle 14 divides the bore 32 into a first channel section 32 ′ and a second channel section 32 ″. As FIGS. 1 b, d , and f each show in respective details I, the first channel section 32 ′ is assigned to the pressure chamber 8 of the main valve 23 , whereas the second channel section 32 ″ is assigned to a second pressure chamber 35 that can be traversed by the pilot piston 7 .
The pilot piston 7 in turn is formed as a flat disk with a centering aid 33 in the form of a truncated cone for a compression spring 26 . The pilot piston 7 is exposed to the force of the compression spring 26 supported with radial play in a bore 34 for the pilot piston 7 and the compression spring 26 . The second pressure chamber 35 , on the front side of the pilot piston 7 , is the same pressure chamber as the space 34 in which the compression spring 26 is placed. Hence, a seal is not required. A bore 36 traversing the wall of the housing 12 for the load sensor LS of the consumer 4 discharges into the space 34 of the pilot piston 7 . The flow pressure of the pilot valve 25 arises from the pressure defined by the compression spring 26 plus the pressure on the load sensor LS. If the pump pressure is greater than the pressure from LS and the pressure set by the spring 24 of the main piston and set by the compression spring 26 of the pilot piston 7 , the pilot valve 25 and consequently the main valve 23 open and the pressure medium can flow out via the main valve 23 to the pressure medium tank 11 .
As FIGS. 1 a to 1 f further show, the relief valve 10 with a valve element 27 , located in an axial region A in a longitudinal bore 40 is able to move between the pilot valve 25 and the main valve 23 , and is connected, in particular, in parallel to the pressure control valve 5 . The relief valve 10 , shown enlarged in FIGS. 1 b, d , and f is incorporated into the housing 12 , is located radially offset laterally to a longitudinal axis 37 of the valve housing 12 and has a diameter roughly identical to the load bore formed by the bore 32 above and below the second throttle 14 . A valve element 27 or a relief valve piston is shown striking an upper stop on which it terminates more or less flush with the end of the bore 34 for the accommodation of the pilot piston 7 . The positions of the relief valve piston which are shown in FIGS. 1 a , 1 b , 1 e , and 1 f correspond to an opened operating position of the relief valve 10 . The relief valve piston is sprung or biased by a smaller energy store 28 , a compression spring that, for example, applies a flow pressure of 0.5 bar on its opposite face side in the sense of an opened position.
In the axial vicinity to the compression spring-side end of the relief valve piston, an annular recess 41 is formed as an annular groove 38 in the periphery of the relief valve piston. In the exemplary embodiment of the valve assembly 1 shown in FIGS. 1 a , 1 b , 1 c , and 1 d , the annular recess 41 communicates with the first channel section 32 ′ of the bore 32 . If, at this point, there is no longer any pressure on the load sensor LS on the side facing away from the load sensor side of the pilot valve piston 7 and thus facing away from the compression spring 28 , the relief valve piston assumes the position shown in FIGS. 1 a , 1 e , and 1 f . The annular groove 38 overlaps an assigned opening 39 of the bore 34 . The pressure medium can thus be routed or conveyed from the pressure chamber 8 on the back 9 of the main piston 6 via the bore 32 , the opening 39 and a connecting line 42 communicating with the opening in the housing 12 via the annular groove 38 to a discharge 15 of the relief valve 10 . The pressure medium 2 then flows out unpressurized without the pressure medium pump 3 having to deliver against the set pressure on the pilot valve 25 . This design measure saves considerable energy in the operation of the hydraulic system equipped with a valve assembly 1 according to the invention when the consumer 4 is shut off. If the pressure on the load sensor LS rises when the consumer 4 is restarted, the relief valve piston travels against the spring force of its compression spring 26 into the position shown in FIGS. 1 c and 1 d closing the opening 39 and the connecting line 42 with the annular groove 38 . The pressure control valve 5 in its above-described control operation is not influenced by the relief valve 10 .
FIGS. 1 e and 1 f in turn show in a schematic longitudinal section (not to scale) a version of a valve assembly 1 modified relative to FIGS. 1 a , 1 b , 1 c , and 1 d , in turn combined in a housing 12 of the pressure control valve 5 with an offset opening 39 to the extent that the drainage of the pressure medium 2 out of the pressure chamber 8 into the LS line is ensured to take place. In this exemplary embodiment, the opening 39 is assigned to the second channel section 32 ″. The second throttle 14 thus acts in a damping manner on the entire operation of the valve assembly 1 , especially on the main piston 6 .
FIGS. 2 and 3 show the interconnection of the three valves 10 , 23 , and 25 with a pressure medium sensor according to the solutions shown in FIGS. 1 a and 1 c . In this way, the valve assembly 1 according to the invention can also be implemented in an unattached valve design.
FIGS. 4 and 5 in turn show a circuit diagram comparable to FIG. 3 , with the relief valve 10 being able to be designed as 2/2-way valve 16 , implemented for the entire volumetric flow of the pressure medium pump 3 .
The relief valve can generally be integrated into an existing pressure control valve as a valve of compact size. Advantageously, the relief valve can be arranged axially between the pilot valve and the main valve with a valve piston of the relief valve being insertable into the housing of the pressure control valve from the pilot valve side. In this way, the main bore for the relief valve can be produced from the same valve side as a throttle between the pressure chamber and the pilot valve.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
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A valve assembly for regulating the pressure of a pressure medium ( 2 ) of a pressure medium pump ( 3 ) to at least one first consumer ( 4 ) includes a pilot-controlled pressure control valve ( 5 ) with a main piston ( 6 ) acted on by the pressure medium ( 2 ) and a pilot piston ( 7 ). A pressure chamber ( 8 ) between a piston back side ( 9 ) of the main piston ( 6 ) and the pilot piston ( 7 ) can be relieved. A relief valve ( 10 ) is connected in a fluid-conducting manner to the pressure chamber ( 8 ), opens when pressure at the load sensor (LS) represents an out-of-operation mode of the consumer ( 4 ), and recirculates pressure medium ( 2 ) having a low pressure to a pressure medium reservoir ( 11 ) or to the pressure medium pump ( 3 ). The relief valve ( 10 ) closes when the pressure at the load sensor (LS) represents an in-operation mode of the consumer ( 4 ).
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BACKGROUND OF THE INVENTION
This invention relates to an improved type of exercise bicycle, which is capable of providing exercise for not only the muscles of the leg, but also muscle groups in the upper part of the body. Most exercise bicycles simulate bicycles and provide exercise for only the muscles of the legs and the lower torso. Activities such as jogging and running, however, may be considered to be more beneficial than cycling, because they involve more muscle groups and place a greater cumulative demand on the aerobic system of the body.
Accordingly, in recent years there has been a need for a bicycle type exerciser which operates as a conventional exercise bicycle, but is also capable of providing exercise for muscle groups in the upper part of the body.
One particular cycle exerciser that has been marketed in recent years by Schwinn is protected by Hooper (U.S. Pat. No. 4,188,030). In the Hooper cycle exerciser, in addition to the conventional pedals 18 and 20, the cycle exerciser also includes elongated levers 28 with handgrips 32. The elongated levers 28 can pivot about the wheel axle 15, and the person using the bicycle can thus obtain exercise of the muscles in the upper part of the body. These elongated levers 28 are connected by means of drive bars 34 to the crank ring 35 which causes rotation of the energy-absorbing wheel 5.
This invention affords another type of exercise bicycle which can provide exercise for both the lower and upper part of they body, but which uses a different system for mounting the arm levers.
SUMMARY OF THE INVENTION
The exercise bicycle of this invention is constructed in the manner of a conventional exercise bicycle with foot pedals, a chain drive system and a flywheel. Extending outward from the axle of the flywheel is a first gear which rotates with the flywheel. A second gear is positioned so as to mesh with the first gear. Located on the face of the second gear, but offset from the center of the gear, is an eccentric which supports reciprocating arms. Movement of the reciprocating arms by the exerciser will cause rotation of the second and first gears and, consequently, the flywheel. Thus, the instant exercise bicycle will also provide exercise for the upper part of the body, as well as the lower part of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
1. FIG. 1 is a right-side, elevational view of the invention.
2. FIG. 2 is a cross-sectional view taken substantially along line 2--2 of FIG. 1.
3. FIG. 3 is a cross-sectional view taken substantially along line 3--3 of FIG. 1.
4. FIG. 4 is an enlarged perspective view showing the first and second gears and the eccentric of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The reciprocating arm levers construction of this invention can be attached to any conventional exercise bicycle.
The typical exercise bicycle would include a frame 2, comprising a base 4, a front support 6, a rear support 8, a seat support 10 and the seat itself 12. An example of one typical type of exercise bicycle is disclosed in Hooper (U.S. Pat. No. 4,188,030). The frame may be made of tubes, as shown in FIG. 1, or it may be made of plates or other structures which will provide a solid support for the exercise bicycle. Preferably the frame will be made of metal, but some plastics or alloy materials may also prove to be suitable. Any conventional bicycle seat or exercise bicycle seat may be used on the exercise bicycle.
The exercise bicycle also includes right and left foot pedals 14, which are mounted in the usual fashion. Rotation of the foot pedals 14 by the user of the exercise bicycle causes rotation of the main drive shaft 16 and the primary sprocket 18. A chain 20 is passed over the sprocket 18 at one end and on the other end it is connected to a secondary sprocket 22. The secondary sprocket is mounted on the surface of a second primary sprocket 23 and a second secondary sprocket 25 is attached to the front energy-absorbing wheel (or flywheel) 24. A second chain 27 connects the second primary sprocket 23 and the second secondary sprocket 25. Thus, pedalling by the user of the exercise bicycle will cause rotation of the primary sprocket 18 and, consequently, the chain drives 20 and 27 and the sprockets 22, 23 and 25, which causes rotation of the flywheel 24. Any of the conventional other systems that are currently in use for exercise bicycles may also be used to link the pedals to the front flywheel 24. In some situations, it may be desirable to use only one chain drive and to connect the first secondary sprocket directly to the front flywheel. In most instances, it will be desirable to place chainguards over the chains in order to prevent the user of the exercise bicycle from getting dirty or getting his clothes or body caught in the chains.
The front energy absorbing wheel 24 may be of any conventional type that are typically used on exercise bicycles. It may be a solid disk, as shown in FIG. 1, or it may be of a cage-like structure, as shown in Hooper.
If desired, a speedometer and/or odometer may be connected to the front wheel in order to provide appropriate read-outs to the user. Any other electronic devices, such as clocks or stopwatches, etc. may also be attached, as is commonly known.
The front wheel 24 rotates about an axle 26 whose distal ends 28 extend out of the right and left side of the front wheel 24. On each of the ends 28 of the axle a small pinion gear 30 is mounted. The axle 26 is designed to rotate with the front wheel 24, so that the pinion gear 30 will also rotate as the front wheel 24 rotates.
The front support of the bicycle includes two upright vertical supports 6, one on each side of the flywheel 24. Journaled in the front supports 6 are axles 33. Mounted on these axles 33 are large gears 32 which are positioned so as to be in mesh with the respective pinion gears 30. As the front wheel 24 rotates and causes rotation of the pinion gear 30, the large gear 32 will necessarily rotate.
Extending outward from the front support 6 is a support rod 34. The lower ends 36 of reciprocating arm levers 38 are mounted for rotation about the support rod 34. One way to do this is to provide an opening 40 in the lower end 36 of the arm levers and to place a bushing (not shown) in the opening and insert the lower end 36 onto the support rod 34. This structure would permit the arm lever 38 to rotate or pivot about the support rod 34. Any other method of connecting the arm lever 38 to the support rod 34 may also be used, provided that it permits rotation or pivoting of the arm lever in the manner hereinafter described. If desired, a footrest can be placed on the support rod 34, outside of the lower end 36 of the arm lever 38.
The arm levers 38 are generally made up of round tubing, and the upper end 44 is bent so as to define a handle portion. In the preferred embodiments, a handgrip may be placed on the distal ends of the handle portion 44.
A pin or bolt 52 passes through the large gear 32 and secures a bottom plate 42 relative to the outer surface 50 of the large gear 32. As shown in FIG. 2, it may be desirable to make the pin or bolt 52 integral with the bottom plate 42. Spindles 54 are used to attach a top plate 56 securely to the bottom plate 42, and rollers 46 and 48 are positioned for rotation on the said spindles 54. The entire structure that is made up by the pin 52, the plates 42 and 56, the spindles 54 and the rollers 46 and 48 serve to define an eccentric 55 which is used to connect the reciprocating arms 38 to the gear train 30 and 32. The pin or bolt 52 is mounted for rotation or rocking within the large gear 32, so that the eccentric 55, as a whole, is permitted some degree of rotation about the outer surface 50 of the large gear 32, as will be hereinafter described.
The arm levers 38 are positioned so that they pass between the plates 42 and 56 of the eccentric and bear against the rounded surfaces 58 of the rollers 46 and 48.
In order to use the exercise bicycle of this invention, the exerciser would sit on the exercise bicycle in a conventional fashion. He could use the foot pedals in the conventional manner and not use the reciprocating arm levers of this invention. Alternatively, he could use both the foot pedals and the reciprocating arm levers or just the arm levers without the foot pedals. Thus, this invention would provide three modes of exercise. In one mode only the lower body would be exercised, in another mode only the upper body would be exercised, and in the third mode both upper and lower portions of the body could be exercised.
In operation, the exerciser would reciprocate or move the arm levers 38 forwards and backwards. At one extreme point, the right arm lever would be forward and the left arm lever would be back, and at the other extreme point the positions would be reversed. As the arm levers are moved back and forth, they will pivot or rotate about the support rod 34. Because the arm levers 38 are held captive in the eccentric structure 55, this reciprocating or back and forth motion of the arm lever will necessarily cause rotation of the gear 32. Because the eccentric is free to float with respect to the surface 50 of the gear 32, the rollers 46 and 48 will maintain their respective positions and will securely hold the arm levers 38. As shown in FIG. 4, as the gear 32 rotates, the eccentric 55 rotates with it. Because the bolt 52 permits the eccentric's structure to slightly rotate or rock, the eccentric is able to maintain its position as the gear 32 rotates. In FIGS. 2 and 4, the eccentric is shown in phantom in different positions on the rotating gear 32.
This rotation of the gear 32 necessarily causes rotation of the pinion gear 30. As the pinion gear 30 is secured to the axle 26, rotation of the pinion gear causes rotation of the axle 26 and the front wheel 24.
In one embodiment of the invention, the ratio of the pinion gear 30 to the gear 32 is 1:9, but this can be changed or modified in order to make it easier or more difficult to reciprocate the arm levers.
In an alternate embodiment of the invention, it is possible for the pinion gear 30 to be eliminated and to simply use the large gear 32 which is secured to the axle 26. Such an arrangement would also come within the scope of the invention and would work.
In some embodiments, it may be desirable to provide an element to disengage the pedals when the exerciser is using only the arm levers 38, and not the foot pedals 14. Thus, the pedals will not rotate when only the arm levers are being used, and this will prevent the needless banging of the foot pedal against the lower legs of the exerciser. For this purpose, a one-way clutch 21 may be provided. In this way, the secondary sprocket 22 will engage the second primary sprocket 23 only when the pedals are being rotated by the feet of the exerciser, but it will not engage when the pedals are not rotated and only the flywheel 24 is being turned. In other words, when the exerciser is using the foot pedals 14, the one-way clutch 21 will engage, and the secondary sprocket 22 will cause rotation of the second primary sprocket 23; and, when the foot pedals are not used and the flywheel 24 is rotating by means of reciprocation of the arm levers 38, the one-way clutch will cause disengagement of the second primary sprocket and the second sprocket 22, thereby preventing rotation of the foot pedals 14. This one-way clutch is shown in FIG. 1, but it can be appreciated that it can be either included or not included at the option of the person making the invention. In some situations it may be advisable to include the one-way clutch between the second secondary sprocket 25 and the flywheel 24, instead of between the secondary sprocket 22 and the second primary sprocket 23.
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The invention includes a conventional exercise bicycle with foot pedals, a chain drive system and a flywheel. Rotating with the flywheel is a first gear which is in mesh with a second larger gear. Located on the face of the second gear, but offset from the center of the gear, is an eccentric which supports reciprocating arms. Movement of the reciprocating arms by the exerciser causes rotation of the second and first gears and, consequently, the flywheel.
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This is a continuation of PCT/AU00/01120 filed Sep. 15, 2000.
The present invention relates to valves, more particularly to outlet valves to control the flow of liquid. It will be convenient to describe the invention in relation to outlet valves for cisterns, especially water cisterns for use in toilets although it will be appreciated that the invention may have wider application.
Environmental concerns about the excessive use of water has lead to numerous domestic practices aimed at reducing water wastage. One such practice involves the use of more water-efficient toilet flushing systems, in particular cisterns which allow the user the option of flushing using a full volume of water or a reduced volume. Building regulations differ from country to country but generally such regulations specify the particular minimum and maximum volumes of water to be used, for example a full flush of 6 liters and a half flush of 3 liters. Although the terms “full flush” and “half flush” are used throughout the description and claims of this specification, it will be appreciated by the skilled addressee that “half flush” is not necessarily exactly half the volume of a “full flush” but, for example, a full flush may equate to 9 liters and a half flush to 6 liters. The term “half flush” should therefore be considered to refer to any desired reduced flushing volume.
A wide variety of dual-flush cistern outlet valves have been proposed and used. Many of these comprise apparatus for dividing the cistern into two separate reservoirs each having separate outlet valves: when a half flush is required, one of the outlet valves is opened so that one of the reservoirs empties. When a full flush is required, both valves are opened so that both reservoirs empty. These and many other dual-flush apparatus generally require two separate actuating systems to open the two valves. It is desirable to reduce the number of separately manufactured parts for a dual flush system.
SUMMARY AND OBJECTS OF THE INVENTION
It is an object of the present invention to provide a dual flush outlet valve which can be made using a minimum of separate moveable parts. It is a further object to provide a dual flush outlet valve which can be suitably adjusted to allow a variety of full and half flush volumes without the need for differently dimensioned components so that the one apparatus can be used throughout the world and adjusted easily to comply with differing regulatory requirements on flushing volumes. It is yet a further object of the present invention to provide a dual flush apparatus which utilises a pivoting or ‘flapper” valve rather than a plunger valve.
Most known dual flush outlet valves also have limited scope to provide variable or extra capacity for overfilling relief from the reservoir, for example In the case of failure of the reservoir filling valve to shut-off when the reservoir has been filled to its desired level. It is an object of another aspect of the present invention to provide a dual flush outlet valve with added fixed or variable overflow protection.
In accordance with the present invention there is provided a dual volume discharge apparatus for selectively discharging a full flush or a half flush of liquid from a reservoir, said discharge apparatus including:
actuator means selectively moveable from a closed position to either a full flush position or a half flush position,
sealing means moveable by said actuator means from a closed position to either a full flush position or a half flush position, said sealing means being biased toward said closed position when in said half flush position,
liquid outlet which is sealed by said sealing means to prevent flow of liquid out of said reservoir when said sealing means is in said closed position and which allows flow of liquid out of said reservoir when said sealing means is in the full flush position or the half flush position,
stop means co-operable with said sealing means and being biased towards position capable of holding said sealing means in said half flush position when said actuator means is moved to said half flush position until a predetermined volume of liquid has been discharged from said reservoir and then allowing aid sealing means to move to said closed position thereafter.
The actuator means is selectively moveable from a closed position to either a full flush position or to a half flush position. The actuator means preferably further includes means for selecting either the half flush or full flush functions. In a preferred embodiment the actuator means includes twin selection means, a first selection means being adapted to move said actuator means from the closed position to the half flush position, and a second selection means being adapted to move the actuator means from the closed position to the full flush position. Said means may be in the form of a dual press-button device where each button when depressed causes the actuator means to move a certain distance, the two buttons each moving the actuator means a different distance. Preferably the half flush position is intermediate the closed and full flush positions and the distance the first selection means moves the actuator means when depressed by the user is less than the distance the second selection means moves the actuator means when depressed.
The actuator means moves the sealing means from a closed position to either a full flush position or to a half flush position. In a preferred embodiment the sealing means is a flapper-type valve and the actuator means acts on the sealing means to cause the sealing means to pivot between said closed, half flush and full flush positions.
The sealing means seals the liquid outlet when the actuator means is in. the closed position. When the sealing means is moved to either of the flush positions, the liquid outlet is opened and liquid in the reservoir is able to flow by gravity out of the liquid outlet.
When in the half flush position, the sealing means is biased toward the closed position. Preferably this bias is caused by the resolved static and dynamic fluid and gravitational forces acting on the sealing means when the sealing means is in the half flush position. When the sealing means has been moved from the closed position, liquid will flow out of the reservoir causing a venturi effect. This will result in a lower pressure acting on the lower surface of the sealing means and a greater pressure acting on the upper surface of the sealing means, the resultant net forces acting to urge the sealing means toward the closed position. Preferably when the sealing means is a flapper-valve, less pivotal movement of the sealing means away from the liquid outlet is required to put the sealing means in the half flush position than in the full flush position. In other words, when the actuator means is moved to the half flush position, the sealing means moves a first distance away from the liquid outlet, but when the actuator means is moved to the full flush position, the sealing means moves a further distance away from the liquid outlet.
Preferably when the sealing means is in the full flush position, the resolved forces acting upon it urge It to remain in that position, at least until the liquid level in the reservoir drops to a point where the sealing means is no longer covered with liquid. The sealing means may include a float which provides a buoyant force greater than any downward acting forces on the sealing means such that it remains in the full flush open position while there is still water in the reservoir but when the water level drops to below the float, the lack of buoyancy will cause the sealing means to close.
The apparatus further includes stop means co-operable with the sealing means. The stop means is biased towards a position capable of holding said sealing means in a half flush position when the actuator is moved to the half flush position. The stop means then holds the sealing means in the half flush position until a predetermined volume of liquid has been discharged from the reservoir. Thereafter, the sealing means moves to the closed position so that no more liquid is able to flow out of the liquid outlet. In a preferred embodiment, the stop means includes a cam which is capable of moving into a locking position when the sealing means is moved into the half flush position and there it is engaged by cooperating latching means associated with the sealing means. The stop means may move into the locking position by way of a float which biases the stop means toward the locking position when the float is providing upward buoyant forces, i.e. when there is liquid at least partially around the float. When the liquid level has dropped so that the float no longer provides upward buoyant forces the stop means may move away from the locking position so that the resultant forces acting on the sealing means cause the latter to move to the closed position and thus prevent further outflow of water from the reservoir.
In another aspect of the present invention there is provided a dual volume discharge apparatus for discharging liquid from a reservoir, said apparatus including:
a main liquid outlet communicating between said reservoir and a discharge passage,
valve means selectively moveable between a closed position where liquid is prevented from flowing out of said reservoir into said discharge passage through said main liquid outlet and an open position where liquid is able to flow out of said reservoir into a discharge passage through said main liquid outlet,
a first overflow passage having an outlet into said discharge passage and an inlet positioned at a selected fill level in said reservoir, and
at least one additional overflow passage having an outlet into said discharge passage and an inlet positioned at a selected fill level in said reservoir, such that when said valve means is in said closed position and liquid in said reservoir reaches said selected fill level liquid will flow into said overflow passages and flow into said discharge passage.
Preferably the additional overflow passage or passages are connected to the apparatus in parallel with the first overflow passage. The additional overflow passages may connect to the apparatus in a modular fashion by for example, a friction fit into an openable port in the apparatus. The additional discharge passages may have a telescopic extension sleeve allowing adjustment of the height of the inlet.
The present invention will now be described in more detail with reference to a preferred embodiment illustrated in the accompanying drawings. The description will refer to a preferred form of the invention when utilised in a toilet cistern. It is to be understood that the drawings and the following description relate to a preferred embodiment only, and are not to limit the generality of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is an exploded view of separate parts of an apparatus made in accordance with the present invention.
FIG. 2 is a side elevation of an apparatus of the present invention shown in the closed position.
FIG. 3 is a side elevation of an apparatus of the present invention shown in the half flush position.
FIG. 4 is a side elevation of an apparatus of the present invention shown in the full flush position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, activator means 1 collectively comprises half flush button 3 , full flush button 5 , push rod 7 and connecting arm 9 . Sealing means 11 collectively comprises float seal 13 and cantilever arm 15 . Liquid outlet 17 is located in apparatus body 19 . Stop means 21 collectively comprises float 23 and float guide 25 .
Half and full flush buttons 3 and 5 are biased toward an upper position where they do not apply any force to the head of push rod unless they are being depressed by the user. Half and full flush buttons 3 and 5 are preferably mounted on the cover (not shown) of the cistern, and are exposed and visible to the user. The remaining parts of the apparatus are most suitably housed within the cistern and may be submerged under water when the cistern is full as is conventional in the art.
Push rod 7 has adjustment stop 27 on its shank 29 which rests on an shoulder 31 in connecting arm 9 . Preferably the adjustment stop 27 can be screwed to a selected position along a thread 33 on shank 29 so that the push rod 7 can be adjusted to an optimal position relative to connecting arm 9 and half and full flush buttons 3 and 5 . Alternative arrangements to a screw thread may be provided for the adjustment stop 27 , although it is considered that a screw thread will provide the greatest degree of adjustability. Push rod 7 may pass through a guide 35 so as to keep its motion (when activated by either of the flush buttons) substantially linear.
In FIG. 2 the apparatus is shown in the closed position. This position correlates to the situation where the cistern is filled with water to the desired level and is ready to be activated to provide either a half flush or a full flush. Connecting arm 9 transfers linear downward motion of the push rod 7 to hinge point 37 where surface 39 of connection arm 9 contacts actuating end 41 of cantilever arm 15 . Preferably connecting arm 9 passes around body 19 which acts as a guide to keep the motion of connecting arm 9 linear. Desirably cantilever arm 15 is hinged about pivot 43 on body 19 . Seal end 45 of cantilever arm 15 has pivotally mounted thereon float seal 13 which consists of sealing gasket 47 and float 49 shown in FIG. 1 . Preferably seal end 45 of cantilever arm 15 includes recesses 51 on the upper side 53 of seal end 45 , said recesses 51 being capable of retaining water therein when the cistern is empty so as to provide ballast to the seal end 45 of cantilever arm 15 after the cistern has been emptied by a full flush. This ballast is the amount of water which can be retained in the recesses 51 will preferably be sufficient so as to weight down the seal end 45 to cause the sealing gasket 47 fall and come into contact with annular outlet rim 55 . Seal end 45 may include a lip 57 adapted to bear upon part 59 of the upper surface 61 of sealing gasket 47 to assist in sealing liquid outlet 17 . Cantilever arm 15 includes cam follower 63 between pivot 43 and seal end 45 .
Body 19 is hollow and incorporates internal overflow passage 65 which extends from overflow inlet 67 to outlet 17 . It will be appreciated that outlet 17 communicates with toilet pan (not shown) such that water flushed from cistern flows into the toilet pan, and water flowing down the overflow passage 65 will also flow into the pan. Overflow passage 65 includes telescopic extension sleeve 69 co-axial with the overflow passage 65 and capable of being adjusted up or down along the axis 71 of overflow passage 65 . Accordingly the height of inlet 67 may be varied as desired so that the level reached by water in the cistern may be selected and determined by the degree to which the telescopic extension sleeve 69 has been extended. Telescopic extension sleeve 69 may include O-ring seal 73 to ensure water does not flow from the cistern into the overflow passage 65 through any gap between the overflow passage 65 and the extension sleeve 69 . The extension sleeve 69 also preferably includes a locking clip 75 to ensure that once it has been extended to a desired height, it is locked into position. Guide 35 may be connected to and extend from telescopic extension sleeve 69 .
The apparatus may further include one or more additional overflow passages 77 in parallel with the overflow passage 65 previously described. The additional overflow passage 77 or passages may be connected in a modular fashion to chamber 79 . Similar to the primary overflow passage 65 , the additional passage(s) may have a telescopic extension sleeve (not shown) allowing adjustment of the height of the respective overflow inlet 81 , or alternatively the additional overflow passages 77 may be of fixed length. The additional overflow passages 77 may be provided to give further protection against overflow of the cistern if the cistern filling valve should fail and water continues to enter the cistern despite reaching the selected filling level.
When in the closed position and when the cistern is full, the weight of water acting on the upper surface 61 of the sealing gasket 47 will hold the gasket 47 against the annular outlet rim 55 of the outlet 17 and this will cause the hinge point 37 of actuating end 41 of cantilever arm 15 to act upon surface 39 of connecting arm 9 to keep connecting arm 9 and hence push rod 7 in an upper position.
Apparatus also includes stop means 21 which facilitates and is essential to the half flushing function of the apparatus. Stop 21 comprises a body 25 19 having a cam end 85 , a float end 87 and a hinge point 89 intermediate said ends 85 and 87 . The hinge point 89 is preferably hinged to the body 19 and the stop 21 is capable of pivoting between a locking position and a release position. On float end 87 there is a float 23 which is adjustably mounted to track 83 . Float 23 may be adjusted along track 83 to a desired height. When cistern is full of water, float 23 will preferably be submerged below the surface of the water so that it provides a buoyant force acting upwardly on hinged stop 21 .
Cam end 85 of hinged stop 21 includes three cam surfaces; a closed cam surface 91 , a half flush cam surface 93 and a full flush cam surface 95 . When the apparatus is in the closed position cam follower 63 bears against the closed cam surface 91 . In this position the downward force of water acting on the upper surface 61 of the sealing gasket 47 is sufficient to overcome any buoyant forces acting on the float 23 so that the hinged stop 21 is held in a downwardly pivoted position. The half flush and full flush cam surfaces 93 and 95 will be described in more detail in relation to later figures.
Turning to FIG. 3, this figure illustrates the configuration of the apparatus when a half flush has been initiated by the user and the water level in the cistern is reducing from a full level to above the selected half flush level. The half flush position is initiated by the user depressing the half flush button 3 . When the half flush button 3 is depressed fully it presses upon the push rod 7 which travels distance A and causes cantilever arm 15 to raise float seal 13 distance B. In the process of moving cantilever arm 15 into the half flush position, cam follower 63 ceases to beer upon the closed cam surface 91 and hinged stop 21 is able to pivot by virtue of the buoyant forces acting on float 23 until half flush cam surface 93 comes into contact with cam follower 63 . The transition from the closed position to the half flush position will generally take only a fraction of a second, being the time it takes for a user to fully depress the half flush button 3 . The half flush button will then react to its normal position.
Once in the half flush position, water will evacuate from the cistern through the outlet 17 as the seal between the sealing gasket 47 and the annular outlet rim 55 will have been broken. Accordingly, the level of water in the cistern will begin to drop. The outflow of water around the seal end 45 and sealing gasket 47 and out of the outlet 17 will result in a net downward force acting on the upper surface 61 of the sealing gasket 47 such that it is urged towards the closed position. The downward forces may be made up of the mass of water above the seal end 45 and sealing gasket 47 acting downwardly on the upper surfaces 53 and 61 of those components. Additionally it is considered that there will also be a significant venturi effect caused by flow of water out of the outlet 17 resulting in a reduced pressure on the underside 97 of the sealing gasket 47 . This added to the other downward forces will urge the sealing gasket 47 towards the closed position. In the half flush position however, the half flush cam surface 93 comes into contact with the cam follower 63 . The shape of the half flush cam surface 93 is such that when the hinged stop 21 is biased upwardly by float 23 said surface engages with the cam follower 63 so as to prevent movement of the cantilever arm 15 towards the closed position. In other words the half flush cam surface 93 provides a temporary lock against which the cam follower 63 acts and is prevented from moving past. The locking action is sufficient to resist the downward acting forces on the seal end 45 and float seal 13 as long as there is an upward force acting on the hinged stop by virtue of the float 23 being immersed in water. Accordingly the locking action of the hinged stop 21 will remain to hold the cantilever arm 15 and float seal 13 in the half flush position until such time as the water level drops in the cistern to a point where the float 23 is no longer immersed in water. As described above, position of the float 23 can be selected by moving it up or down along track 83 . Therefore by selecting an appropriate position for the float 23 on the track 83 , this dictates the level at which the hinged stop 21 ceases to provide the half flush locking function and thus the sealing gasket 47 will close to prevent further flow of water out of the cistern.
When the water level has dropped to a point where the float 23 no longer provides an upward force on the hinged stop 21 , the hinged stop 21 will pivot back to the downwardly pivoted position, the same as when the apparatus is in the closed position. The half flush cam surface 93 will therefore move back away from the cam follower 63 allowing the cantilever arm 15 to move to the closed position.
FIG. 4 shows the apparatus in the full flush position. This position is adopted when the user depresses the full flush button 5 . The full flush button 5 moves push rod 7 distance C, which is greater than distance A. This causes cantilever arm 15 to raise float seal 13 distance D. It can be seen that in the process of moving cantilever arm 15 into the full flush position, cam follower 63 moves past the half flush position until it bears on full flush cam surface 95 . Again the transition from the closed position to the full flush position will generally only take a fraction of a second, being the time it takes for a user to fully depress the full flush button 5 . Full flush button then retracts to its normal position. The speed of actuation is such that half flush cam surface 93 of the hinged stop 21 does not have time to engage the cam follower 63 as the cantilever arm 15 is moved from the closed position through the half flush position to the full flush position. The cam follower 63 may abut the full flush cam surface 95 although the action between this surface and the cam 63 is not critical.
When in the full flush position, water will evacuate from the cistern through the outlet 17 as the seal between the sealing gasket 47 and the annular outlet rim 55 will have been broken. The level of water in the cistern will drop. In the full flush position, although water will be flowing around the sealing gasket 47 and the seal end 45 , sealing gasket 47 will be positioned such a distance away from the any venturi effect described above such that there is little if any such downward force acting upon it. Further, float 23 will have an upwardly acting buoyancy force acting upon its surface because float 23 will be surrounded with water, unlike the situation in the half flush position. The net forces acting on the cantilever arm 15 in the full flush position while the water level is above the seal end 45 and float 23 will cause it to remain in that position.
As the water level drops to a point where the float 23 no longer provides a dominant upward force, which will generally be when the water level has dropped to the position of the float 23 , the downward forces acting on the seal end 45 will cause the cantilever arm 15 to move to the closed position. At such a point, a full flush volume of water will have been discharged from the cistern. Water trapped in the recesses 51 of the seal end 45 will provide a mass to assist in moving the apparatus to the closed position. As the water level rises to fill the cistern in preparation for a future flush the mounting downward forces acting on the sealing gasket 47 will hold it in the closed position.
The apparatus may be made from any suitable materials by any suitable means. For example, various components of the apparatus may be made by injection moulding of polymeric materials.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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A dual volume discharge apparatus for selectively discharging a full flush or a half flush of liquid from a reservoir, said discharge apparatus including: actuator means ( 1 ) selectively moveable from a closed position to either a full flush position or a half flush position, sealing means ( 11 ) moveable by said actuator means ( 1 ) from a closed position to either a full flush position or a half flush position, said sealing means being biased toward said closed position when in said half flush position, liquid outlet ( 17 ) which is sealed by said sealing means ( 11 ) to prevent flow of liquid out of said reservoir when said sealing means ( 11 ) is in said closed position and which allows flow of liquid out of said reservoir when said sealing means ( 11 ) is in the full flush position or the half flush position, stop means ( 21 ) co-operable with said sealing means and being biased towards position capable of holding said sealing means in said half flush position when said actuator means in said half flush position until a predetermined volume of liquid has been discharged from said reservoir and then allowing said sealing means ( 11 ) to move to said closed position thereafter.
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This disclosure is a division of U.S. application Ser. No. 09/409,348, filed Sep. 30, 1999, now U.S. Pat. No. 6,291,915.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an eccentric rotor used as a silent call device for a mobile communications apparatus, a compact vibrator motor having the rotor and a method of manufacturing the rotor, and more particularly, to an improvement of assembly and structure of an eccentric rotor which does not require an eccentric weight.
2. Description of the Related Art
Referring to FIG. 21, as a silent call device for a pager or a mobile phone, an eccentric weight W made of tungsten alloy is coupled to an output shaft S of a cylindrical DC motor M. When the motor M rotates, vibrations are generated due to the difference in centrifugal force of the eccentric weight W.
However, as the above addition of the eccentric weight W to the output shaft S requires a space for rotation of the eccentric weight W in an apparatus such as a pager, there is a limit in designing the apparatus. Also, use of the expensive tungsten alloy increases the production costs.
The present applicant have suggested a cylindrical coreless vibrator motor in Japanese Patent Application No. Hei 2-309070 and the corresponding U.S. Pat. No. 5,107,155, in which a built-in rotor itself is made eccentric excluding an output shaft. The above motor having no output shaft and no eccentric weight is favorably noticed by the market as there is no limit in design, use thereof is easy and there is no danger during rotation. However, as the motor requires three cylindrical coreless coils, the number of parts or processing steps increases, thus increasing the production costs.
In order to make a rotor with a core itself vibrate instead of the cylindrical coreless coil type, the present applicant has suggested removing one of three salient pole type cores as shown in FIG. 4 of Japanese Patent Publication No. Hei 6-81443. The above two salient pole type cores where one pole in three phases is missing are preferable in the case of a motor such as a massager needing a relatively large amount of output. However, for a portable apparatus such as a portable terminal using a low voltage, as the portable apparatus is small, movement of the center of mass is little and the amount of vibrations is insufficient.
Also, as disclosed in U.S. Pat. No. 5,341,057, the present applicant has suggested a compact vibrator motor having an eccentric armature iron core which is formed by arranging three salient poles made of magnetized material at one angular side with respect to a rotor to face a field magnet having four alternate north and south pole sections. Also, the same technical concept has been disclosed in Japanese Laid-open Patent Application No. 9-261918. However, as the three armature iron cores made of magnetized material are distributed at one angular side and cogging torque (a force of being absorbed by a field magnet) increases in the case of the motor, pores needs to be enlarged and the diameter of the motor itself cannot be reduced.
The above motor having a built-in type eccentric rotor becomes a shaft-fixed type as it does not need an output shaft. As the size of the above motor is reduced, the distance between armature coils decreases. Thus, connection of the end portion thereof to the commutator without damage to the armature coil is very difficult. Particularly, when a printed circuit board is used as a flat panel commutator as it is, where the end portion of the armature coil is directly welded thereon, welding of the end portion is not easy as the end portion is easily detached from a printed pattern due to elasticity of the end portion.
SUMMARY OF THE INVENTION
To solve the above problems, it is the first objective of the present invention to provide a structure of a built-in type non-mold eccentric rotor to obtain vibrations with only an eccentric rotor in which each end portion of an armature coil can be easily connected to a commutator.
It is the second objective of the present invention to provide the structure in which the armature coil can be easily fixed although arranged to be inclined.
It is the third objective of the present invention to provide an eccentric rotor having a resin bearing portion, without using a sintered oil-storing bearing, which has advantages in that a mechanical noise can be reduced, the number of parts can be reduced as the commutator functions as a bearing, and the production costs can be saved.
It is the fourth objective of the present invention to secure a sufficient maintenance intensity using a printed wiring commutator device in arranging a guide for determining the position of a resin holder having a bearing portion and an air-core coil when a non-molding type flat rotor is configured to solve the problems of the conventional mold type.
It is the fifth objective of the present invention to provide an eccentric rotor in which the nature of sliding and the amount of eccentricity coexist.
It is the sixth objective of the present invention to solve the problems of the conventional mold type or loss of properties, without sacrifice of the thickness, by forming a printed wiring coil at the eccentric printed wiring commutator device constituting a non-mold type flat rotor.
It is the seventh objective of the present invention to provide a low-postured eccentric rotor, that is, a thin vibrator motor.
It is the eighth objective of the present invention to provide a method of manufacturing a non-mold type flat rotor which can be subject to mass production due to the property of a printed wiring commutator device.
Accordingly, to achieve the above objects, there is provided an eccentric rotor which includes a printed wiring commutator device where a hole for shaft installation is formed at the center thereof and a plurality of segment patterns are formed at the periphery of one surface thereof, a winding type armature coil integrally formed in a non-mold manner so as to be eccentric toward the other surface of the printed wiring commutator device, an end connection portion installed at such a position at the outer circumferential portion of the printed wiring commutator device that latching an end portion of the winding type armature coil is possible within a range of not deviating from the turning circumference during rotation and simultaneously electrical connection with the segment patterns is possible, and also at the position of not overlapping the winding type armature coil viewed from a plane, a resin bearing holder inserted in the shaft installation hole so that part thereof protrudes toward the segment pattern and simultaneously the other part thereof is extended toward the other surface of the printed wiring commutator device, and a resin eccentric weight exhibiting density of over 3 installed at the printed wiring commutator device.
It is preferred in the present invention that the resin bearing holder exhibits a feature of sliding of a mobile friction coefficient equal to or less than 0.4 (1.5 kg/cm 2 ) and is installed in a bearing hole located at the center to be capable of directly rotating to the shaft.
It is preferred in the present invention that a compact vibrator motor includes a printed wiring commutator device where a hole for shaft installation is formed at the center thereof and a plurality of segment patterns are formed at the periphery of one surface thereof, a winding type armature coil configured in a non-mold manner by being wound around two magnetized salient poles, which become a winding type armature coil position determination guide, facing each other and by making an open angle of wiring of a blade receiving magnetic flux of a field magnet eccentric, at the other surface of the printed wiring commutator device, an eccentric rotor having an eccentricity accentuating non-magnetized salient pole simultaneously used as a resin holder and an eccentric weight made of sliding, high density resin exhibiting density of equal to or more than 3 and a mobile friction coefficient of equal to or less than 0.4 (1.5 kg/cm 2 ), and arranged such that the thickness thereof is within a thickness in the axial direction of the winding type armature coil, by being inserted in the shaft installation hole, to maintain the magnetized salient poles, between two magnetized salient poles, a shaft supporting the eccentric rotor to be capable of rotating, and a housing accommodating the eccentric rotor and a magnet for applying magnetic force to the eccentric rotor.
It is preferred in the present invention that the compact vibrator motor further comprises an eccentric rotor configured by winding a third armature coil around the non-magnetic salient pole.
To achieve the above objects, there is provided an eccentric rotor including a printed wiring commutator device formed to be eccentrically as an expanded fan viewed from a plane, in which a hold for shaft installation is formed at the center thereof and a plurality of segment patterns are formed at the periphery of one surface thereof, a winding type air-core armature coil incorporated in an air-core armature coil position determination guide in a non-mold manner, which protrudes and is formed to be eccentric at the other surface of the printed wiring commutator device, an end connection portion installed at such a position at the outer circumferential portion of the printed wiring commutator device that latching an end portion of the winding type armature coil is possible within a range of not deviating from the turning circumference during rotation and simultaneously electrical connection with the segment patterns is possible, and also at the position of not overlapping the winding type armature coil viewed from a plane, a resin bearing holder inserted in the shaft installation hole so that part thereof protrudes toward the segment pattern and simultaneously the other part thereof is extended toward the other surface of the printed wiring commutator device, and a resin eccentric weight exhibiting density of over 3 installed at a fan-like arc-shaped portion of the printed wiring commutator device.
It is preferred in the present invention that the air-core armature coil position determination guide and the eccentric weight are connected by a resin passing portion installed at the printed wiring commutator device for reinforcement.
It is preferred in the present invention that the resin bearing holder, the air-core coil position determination guide and the arc-shaped eccentric weight are connected together by the same resin.
It is preferred in the present invention that, in forming conductive bodies electrically connecting predetermined segment patterns of the printed wiring commutator device through through holes, the through holes are used as a resin passing portion when the resin bearing holder is formed integrally.
To achieve the above objects, there is provided a compact vibrator motor including an eccentric rotor; a shaft supporting the eccentric rotor for rotating; and a housing accommodating the eccentric rotor, and a magnet for applying a magnetic force to the eccentric rotor.
It is preferred in the present invention that an eccentric rotor includes an eccentric printed wiring commutator device formed as an expanded fan viewed from a plane, in which a hole for shaft installation is formed at the center thereof, a plurality of segment pieces are exposed toward the periphery of one surface thereof, at least one armature coil is formed in a printed wiring manner at at least one surface, a winding type armature coil installation guide is eccentrically incorporated, and an end connection portion for each coil is arranged in the turning outer circumference during rotation, a winding type air-core coil incorporated in the air-core position determination guide in a non-mold manner and the end portion is connected to the end connection portion, a resin bearing holder inserted in the shaft installation hole so that part thereof protrudes toward the segment pattern and simultaneously the other part thereof is extended toward the other surface of the printed wiring commutator device, and a resin eccentric weight exhibiting density of over 3 installed at a fan-like arc-shaped portion of the printed wiring commutator device.
It is preferred in the present invention that a printed wiring commutator device is provided in which an armature coil formed by the printed wiring is formed at both surfaces, the device functioning as one coil through a through hole.
It is preferred in the present invention that, in forming bodies electrically connecting predetermined segment patterns of the printed wiring commutator device through the through holes, the through holes are used as a resin passing portion when the resin bearing holder is formed integrally.
It is preferred in the present invention that resin holder, air-core coil position determination resin guide and eccentric weight are integrally formed at the printed wiring commutator device using the same sliding resin exhibiting density of equal to or more than 3 and a mobile friction coefficient of equal to or less than 0.4 (1.5 kg/cm 2 ).
To achieve the above objects, there is provided a method of manufacturing an eccentric rotor which includes the steps of (a) forming a hold for shaft installation at the center thereof and at least a plurality of segment patterns at the periphery of one surface thereof, installing an end connection portion at the outer circumference thereof, and installing a plurality of printed wiring commutator devices where a resin passing portion is formed through a connection portion arranged at the outer circumference thereof, (b) integrally forming a resin bearing holder with resin exhibiting a sliding property and a mobile friction coefficient of equal to or less than 0.4 (1.5 kg/cm 2 ) by setting the printed wiring commutator device to an injection mold, (c) integrally installing a winding type armature coil to be eccentric by separating from each connection portion or as it is, in a non-mold manner, and (d) configuring an eccentric rotor by connecting an end portion of the winding type armature coil to the end connection portion.
It is preferred in the present invention that, when the resin bearing holder is integrally molded in the step (b), the air-core coil position determination guide and the eccentric weight are formed concurrently, that the method further includes a step of injection-molding at least an eccentric weight portion with resin exhibiting density over 3, after the step (b), and that, as a means for installing a winding type armature coil of the step (c) of claim 45 , the air-core armature coil determination guide is heated and extended.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objectives and advantage of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a cross sectional view showing a compact vibrator motor having an eccentric rotor according to the first preferred embodiment of the present invention;
FIG. 2 is a vertical sectional view of the motor of FIG. 1;
FIG. 3 is a vertical sectional view of a modified example of the motor of FIG. 1;
FIG. 4 is a view for explaining the principle of operation of the above motor;
FIG. 5 is a cross sectional view showing a motor according to the second preferred embodiment of the present invention;
FIG. 6 is a cross section view showing a modified example of the motor according to the second preferred embodiment of the present invention;
FIG. 7 is vertical sectional view taken along line α-β of FIG. 6;
FIGS. 8 (A) and 8 (B) are cross sectional views showing another modified example of the motor according to the second preferred embodiment of the present invention, in which FIG. 8 (A) is a cross sectional view viewed from opposite the commutator and FIG. 8 (B) is a cross sectional view viewed from the commutator's side;
FIG. 9 is a vertical sectional view taken along line γ-δ of FIG. 8;
FIG. 10 is a vertical sectional view of a modified example of the motor shown in FIG. 9;
FIGS. 11, 12 , 13 and 14 are plan views showing a method of manufacturing major members of the eccentric motor according to the present invention;
FIG. 15 is a cross sectional view of an eccentric rotor according to the third preferred embodiment of the present invention, which is viewed from the side of a segment;
FIG. 16 is a plan view of the eccentric rotor of FIG. 15, viewed from the opposite side of the segment;
FIG. 17 is a cross sectional view of the eccentric rotor integrated with a resin holder and made to a non-mold type flat rotor, viewed from the opposite side of the segment;
FIG. 18 is a cross sectional view of the eccentric rotor integrated with a resin holder and made to a non-mold type flat rotor, viewed from the opposite side of the segment;
FIG. 19 is a vertical sectional view of an axial direction pore type coreless vibrator motor having an eccentric rotor, taken along line ε-η of FIG. 13;
FIG. 20 is a view for explaining the operation of the axial direction pore type coreless vibrator motor using the above rotor; and
FIG. 21 is a perspective view showing a conventional compact vibrator motor.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 and 2, letter m denotes a ring type field magnet made of rare-earth plastic material consisting of N/S alternating magnetized 6 pole sections. H 1 denotes a casing made of a tin-plated steel plate which maintains the field magnet m and concurrently provides a path for magnetic field. Letter C denotes an eccentric core made of two sheets of silicon steel plates. Two blades Ca and Cb disposed to face each other while forming an open angle are slightly larger than the field poles and simultaneously the overall open angle of the two blades Ca and Cb, viewed from a plane, is formed to be within four poles+N (N is non-magnetized portion) of the magnet m. Also, two salient poles Ta and Tb (coil portions) incorporated in the blades Ca and Cb are eccentric so as to not be in a radial direction from the center of the core C, to be off the center of each blade, and to be at an eccentric position with respect to the center of the core C, so that an armature coil described later can be easily wound. The armature coils C 1 and C 2 are wound around the outer circumference of the magnetic salient pole of the eccentric core via a coating layer (not shown), and the end connecting portion is connected to the outer circumference of the opposite weight center of the commutator so as to not overlap a commutator made of a printed wiring commutator device, described later, when viewed from a plane.
An eccentric armature core TD is configured by a non-magnetized salient pole D situated between two salient poles Ta and Tb. The non-magnetized salient pole D for accentuation of eccentricity is made of a high sliding, i.e., low friction, resin of density (specific gravity) over 5 to simultaneously function as a bearing. A bearing hole Da is formed in the center of the non-magnetized salient pole Dc. The commutator S made of the printed wiring commutator device is inserted in and incorporated in a hole Sa for shaft installation disposed at the center thereof around the bearing hole Da opposite the center of the non-magnetized salient pole D. The commutator S has 9 sectioned segments Sa, Sb, Sc, Sd, Se, Sf, Sg, Sh and Si, described later, of which a sliding surface is plated with a noble metal. Concave portions X, Y, and Z and k for supporting an armature coil end connecting portion made of a half through hole (having the outer circumference thereof notched), at the segment disposed at the opposite central side. In this case, the concave portion k as a common electrode is independent of all segments.
Thus, the end connecting portion is situated within a pivot space.
The non-magnetized salient pole D also used as the bearing determines the position to be coupled by a guide hole e formed in the eccentric core C. Also, as the high sliding resin of density (specific gravity) over 3, resin of specific gravity 3 through 7 is selected considering balance between properties of high specific gravity and high sliding.
In the eccentric armature core TD, an air-core armature coil Db is wound around the blade of the non-magnetized salient pole D and this portion is of a coreless type.
Each initial end portion of the armature coils C 1 and C 2 and the air-core armature coil Db is preliminary welded so that the initial end portion is hooked by the respective concave portionsX, Y, and Z. The terminating end portion of the coil, including the air-core armature coil Db, is hooked together by the concave portion k and connected through welding in a star-shaped connection manner. Also, the commutator S has an electrode pattern, not specifically shown here, electrically connecting every two other commutator pieces, forming an eccentric rotor R 1 . Thus, the end connection portion is separated from each armature coil in a plane so that welding is made easy.
The eccentric rotor R 1 having the above structure is rotatably installed through the bearing hole Dc of the non-magnetized salient pole concurrently used as a bearing at a shaft J fixed to a bracket H 2 constituting a housing with the casing H 1 . A pair of brushes B and B arranged through welding at the bracket H 2 through a flexible substrate F slidingly contact the commutator S at an open angle an odd number of times (here, 180 degrees) so that electric power is supplied to the armature coils C 1 and C 2 .
Also, although the commutator is described as a flat plate type formed of a substrate for a printed wiring circuit in each preferred embodiment, it is alright that a substrate K 1 for printed wiring circuits which are not plated with a noble metal as a wiring of conductive bodies (not shown) which connect the commutator pieces facing as shown in FIG. 3 be integrally formed and a thin cylindrical commutator S 2 welded at each terminal S 2 a . In this case, the concave portions X. Y, Z and k are installed at the outer circumference of a substrate for a printed wiring circuit K 1 which is not plated with the noble metal, as each initial end connection portion of the armature coils C 1 and C 2 and the air-core armature coil Db. For making a slim body, at least a part of the printed wiring circuit substrate K 1 and a terminal portion (a riser portion) S 2 b of the cylindrical commutator S 2 is accommodated within the thickness of the non-magnetized salient pole D. Also, the brushes B 1 and B 2 slidingly contacting the thin cylindrical commutator S 2 are installed at the bracket H 2 by being bent to avoid a protrusion where the armature coil is wound. Also, a part of a support portion H 2 a of the shaft J fixedly installed at the bracket H 2 is inserted in the cylindrical commutator S 2 .
Such a structure makes it possible to form a cored motor, having a protrusion about which the armature coil is wound, that is thin. Also, instead of each concave portion, each terminal portion S 2 b of the cylindrical commutator S 2 may protrude toward a position opposite the center.
When a DC voltage from a power source (not shown) is applied to a pair of brushes B 1 and B 2 , and when the eccentric rotor R 1 , consisting of the armature coils C 1 and C 2 , the magnetized salient poles Ta and Tb (a coil portion) and the commutator S, is at the position of 0 degrees, current flows in a direction indicated by arrows though the armature coil and the blades Ca and Cb of the salient pole are respectively magnetized by N and S poles. The blade Ca is attracted by S 1 pole of the field magnet and simultaneously repels N 1 . Here torque in a direction indicated by arrow A is generated. When the rotation proceeds to 30°, as the blade Cb is magnetized to S pole so as to be attracted by N 3 pole of the field magnet and simultaneously repelled by S 2 pole, torque in the direction indicated by arrow A is generated. Here, the armature coil C 1 becomes non-conductive and the north pole facing the south pole of the blade Ca of the salient pole Ta, so as to be attracted to the S 1 pole of the field magnet. Also, the air-core armature coil Db of the non-magnetized salient pole D becomes conductive, and torque in the direction indicated by arrow A is generated according to Fleming's left-hand rule. Thus, stronger rotation can be obtained. Anti-torque to hinder the rotation is not generated at the other positions. Also, when the rotation further proceeds to 60° of FIG. 4, current flows in the reverse direction, but the position of the field magnet is changed to the contrary. Thus, torque is generated in a direction indicated by arrow A for rotation. Anti-torque to hinder the rotation is not generated at the other positions.
Thus, as long as the power is supplied, the rotation continues periodically. Also, although the above description is based on the star-shaped connection type, a delta connection type can be used by changing the position of the brush.
Each preferred embodiment adopting the coreless eccentric rotor will now be described. Here, the portions having the same functions are indicated by the same reference numerals and the description thereof may be omitted.
FIG. 5 shows a motor according to the second preferred embodiment of the present invention. Reference numeral 1 denotes an eccentric commutator device made of a printed wiring circuit substrate shaped as an expanded fan viewed from a plane and having a hole 1 a for shaft installation at the center thereof. To encompass the eccentric commutator device 1 , high sliding, i.e., low friction, resin 2 exhibiting high density of specific gravity 6 is integrally and thinly formed on the entire surface of the eccentric commutator device 1 , like a half-circle viewed from a plane, so as to form an eccentric commutator SS. Six printed wiring segment patterns is having inclined slits for preventing a spark are arranged at the eccentric commutator device 1 . An armature coil end connection terminal 1 b protrudes from the semicircular arc shaped bottom portion of three segment patterns at the movement of the center. The eccentric commutator device 1 is installed by being extended with an reinforced portion 1 c to the inside of both ends of a half-circle of which both ends are formed of high density high sliding resin 2 . The segment patterns is electrically connect each segment pattern facing each other according to the rotation using the inside surface through a pattern on the surface and a through hole 1 A. A resin bearing holder 2 a ascends from the high density high sliding resin 2 toward the opposite segment pattern in the shaft installation hole 1 a at the center of the eccentric commutator device 1 . A bearing hole 2 b is formed at the center of the eccentric commutator device 1 and is maintained at the eccentric commutator device 1 by a dam portion 2 c protruding toward the segment pattern from the high density high sliding resin 2 .
In the eccentric commutator device 1 having the above structure, an arc shaped portion 2 d which becomes a portion of an eccentric weight for center movement is installed at the semicircular outer circumferential portion. Air-core armature coil position determination fixing guides 2 e , described later, are integrally formed with the high density high sliding resin 2 , as indicated by a dotted line, at the inside surface of each of the six segment patterns 1 s at an arranged open angle of 120°. The air-core armature coils 3 and 3 made of a winding around a self-fusing line are inserted in the air-core armature coil position determination fixing guides 2 e and the beginning and termination end portions of the winding are wound around the armature coil end connection terminal 1 b , and dipping-welded thereto, through a predetermined groove so as to not come out from the thickness of the rotor, thus forming an eccentric rotor R 2 . A magnet 4 for driving the rotor is magnetized to have four alternating N/S poles.
Also, the principle of operation in which one phase is open in the above three phase armature coil will be omitted as it is a well-known technology.
FIG. 6 shows a cross sectional surface of the vibrator motor using a modified eccentric rotor of FIG. 5; and FIG. 7 shows a vertical sectional surface of the vibrator motor shown in FIG. 6 . The eccentric commutator device 11 is formed to be slightly greater than a half-circle viewed from a plane and the armature coil end connection terminal if is installed at the opposite position of the center, unlike the above embodiment.
A notch f for hooking is formed at each of the armature coil end connection terminal 1 f . The armature coil end connection terminal 1 f is disposed to not overlap the air-core armature coils 3 , viewed from a plane, so that the connection of the end portion is made easy.
In the shaft installation hole 1 a at the center of the eccentric commutator device 11 , a resin bearing holder 2 a lifted from the semicircular high density high sliding resin 2 is installed by being extended toward the opposite position of the segment pattern, and a bearing hole 2 b is formed at the center thereof. A dam portion 2 c formed of the high density high sliding resin 2 protrudes toward the segment pattern. The second dam portion 2 cc for reinforcement is installed toward the segment pattern at the part of the resin bearing holder 2 a via the through hole 1 A. Each of the dam portions 2 c and 2 cc is molded to prevent the resin from flowing into each slit of the segment 1 s.
The air-core armature coils 3 and 3 made of a winding around a self-fusing line are inserted in the air-core armature coil position determination fixing guides 2 e and the beginning and termination end portions of the winding are welded to the armature coil end connection terminal 1 f , so as to not come out from the thickness of the rotor, thus forming an eccentric rotor R 3 . Preferably, as a fixing device for the air-core armature coil 3 , the air-core armature coil position determination fixing guides 2 e are deformed by heating and fused, or are fixed by a reflow of powder or solid epoxy.
The motor including the eccentric rotor R 3 is an axial direction pore type and driven by a flat magnet 4 . Reference numeral 5 denotes a bracket made of a tinplated steel plate for maintaining the magnet 4 and concurrently providing a magnetic path. The bracket 5 forms a housing with a case 6 . A shaft J fixed at the center of the bracket 5 is rotatably installed through the bearing hole 2 b of the resin bearing holder 2 a . A pair of brushes 7 and 7 disposed at the bracket 5 sliding-contact the segment pattern at an open angle of 90° so that power is supplied to the armature coils 3 and 3 from the outside via a flexible substrate 8 .
FIGS. 8 (A) and 8 (B) show a modified shape of the second preferred embodiment shown in FIG. 6, in which FIG. 8 (A) is a cross sectional view viewed from opposite the commutator and FIG. 8 (B) is a cross sectional view viewed from the side of the commutator. That is, reference numeral 111 denotes a printed wiring commutator device formed to have an expanded fan shape, viewed from a plane, and six segments 1 s, of which surfaces are plated with the noble metal and having inclined slits, are arranged on one side thereof for spark prevention. Conductive bodies electrically connect the segments facing each other among the above segments are formed at an inner surface via the through hole 1 B. Reference numerals 1 h , 1 i , 1 j and 1 k denote a resin passing portion which is one of the features of the present invention. The resin passing portion is reinforced when a resin holder, an air-core coil position determination guide, an eccentric weight, which will be described later, are integrally formed with the printed wiring commutator device 11 . The resin passing portions 1 h and 1 i are installed at the air-core coil position determination guide, the resin passing portions 1 j and 1 k formed by notching a part of the outer circumference are installed at the eccentric weight, and the through hole 1 B is installed at the resin bearing holder 2 a.
A sliding portion 2 h where the bearing hole 2 b and an oil storing groove rotatably installed at a shaft which will be described later are coaxially installed is arranged at the resin bearing holder 2 a , and passes through the through hole 1 A by leg portions which are well arranged to be balanced. The second dam portion 2 cc at the surface and the first dam portion 2 c at the central portion are reinforced by being coated with resin.
Part 2 f of the eccentric weight lifts the other part 2 d of the arc-shaped eccentric weight toward the segment through the resin passing portion 1 j . Both ends of the other part 2 d of the eccentric weight are tapered to prevent loss of wind during rotation.
Next, FIG. 9 shows a flat coreless vibrator motor using the eccentric rotor R 4 . As the bearing hole 2 b has a recess c of a few microns formed inside, loss of bearing is reduced. In a means for forming the recess c, a middle portion of the resin holder 2 a is thicker than other portions as shown in the drawing so that a recess can be easily formed using the difference in percentage of contraction of resin. Also, the few-micron recess can be fabricated by excessive drawing with a mold pin.
As the resin bearing holder, the air-core coil position determination guide, and the eccentric weight can be formed together with the single resin injection molding according to the above method, the structure is simplified and the cost is lowered. Also, as the air-core coils 3 and 3 can be directly installed at the printed wiring commutator device 11 , pore can be made small and efficiency is increased.
Also, as shown in FIG. 10, it is possible that the resin bearing holder 22 a is formed of low density sliding resin and then the air-core coil position determination guides 2 e and the eccentric weight portions 2 f and 2 n are molded with a high density resin.
FIGS. 11, 12 , 13 and 14 shows a basic method of manufacturing an eccentric rotor having the above eccentric printed wiring commutator device. That is, eccentric printed wiring commutator devices 1 , 11 and 111 are plurally and integrally connected by the connection portions 1 g at the same pitch for mass production and are manufactured through press work.
The printed wiring commutator device 11 manufactured in the above method, as shown in FIGS. 12, 13 and 14 , is set to an injection mold installed by being connected plurally at the same pitch. By outset molding using resin of about specific gravity 4-5 and mobile friction coefficient of 0.3 (15 kg/cm 2 ), the resin holder 2 a , the two air-core coil position determination guides 2 e , and the part 2 f of the eccentric weight connected to the resin bearing holder 2 a are installed at the opposite side of the segment.
The bearing hole 2 b rotatably installed at the shaft J which will be described later and the sliding portion 2 h where the oil storing groove is coaxially installed are arranged at the resin holder 2 a . The well-arranged and balanced leg portions penetrate the through holes 1 A and the second dam portion 2 cc at the surface and the first dam portion 2 c at the central portion are coated with resin for reinforcement.
The part 2 f of the eccentric weight lifts the other part 2 d of the arc-shaped eccentric weight toward the segment through the resin passing portion 1 j . Both ends of the other part 2 d of the eccentric weight are tapered like the above leg shape to prevent loss of wind during rotation.
The air-core armature coils 3 and 3 are inserted in the air-core armature coil position determination guide 2 e and the beginning and termination end portion of a winding are hooked and welded on the notch f of the three air-core coil end connection terminals 1 If, thus forming the eccentric rotor. In the drawing, r denotes a printed resistor for preventing spark.
Also, as a fixing unit of the air-core armature coil 3 , preferably, a head portion 2 ee of the air-core armature coil position determination guide 2 e is pressed and welded by a heated wedge-shaped jig, or heated and cured by powdered epoxy or fixed in a reflow manner using an ultraviolet curing type adhesive. Also, although one phase is open in the three-phase armature coil, the description thereof will be omitted as the principle of operation is a well-know technology.
FIGS. 15 and 16 show an eccentric rotor according to the fourth preferred embodiment of the present invention. Here, reference numeral 12 denotes an eccentric printed wiring commutator device formed to be an expanded fan viewed from a plane, in which a shaft installation hole 1 a is formed at the center thereof and simultaneously the six segments 1 s of which surfaces are plated with the noble metal and having inclined slits installed at one side thereof for spark prevention. Part C 3 of the armature coil is print-wired above the segments 1 s and part C 4 of the armature coil is print-wired on the other side of the eccentric printed wiring commutator 12 and the parts C 3 and C 4 are connected in series through the through hole 1 A to characteristically form a single armature coil. The resin passing portions 1 h , 1 k and 1 n , which are the characteristic feature of the present invention, are reinforced when the resin bearing holder, the air-core coil position determination resin guide, and the resin eccentric weight are integrally formed with the printed wiring commutator device 11 as described above. Of the resin passing portions, the resin passing portion 1 h is hooked by the air-core coil position determination resin guide and the resin eccentric weight, the slit 1 n and the resin passing portion 1 k formed by notching part of the outer circumference are hooked by the resin eccentric weight, and the through hole 1 A is hooked by the resin bearing holder. In the drawing, reference numeral 2 ef denotes a space for drawing the end portion of the air-core armature coils 3 and 3 .
The printed wiring commutator device 12 having the above structure is set to an injection mold by being connected plurally at the same pitch, as shown in FIG. 14 . As shown in FIG. 18, by outset molding using resin of about specific gravity 4-5 and mobile friction coefficient of 0.3 (15 kg/cm 2 ), the resin holder 2 a , the two air-core coil position determination guides 2 e , and the part 2 f of the eccentric weight connected to the resin bearing holder 2 a are installed at the opposite side of the segment.
The axial direction pore type coreless vibrator motor using the above eccentric rotor R 5 is assembled as shown in FIG. 19 . Here, it is characteristic that an insulation copper wire 9 is embedded in the eccentric weight. In this case, the insulation copper wire 9 is coated with polyurethane except for cut-away portions of both ends thereof and formed to be arc-shaped so as not to be shorted by the printed wiring armature coil located inside. As a result, the position of the center can be moved much further so that vibrations become greater.
In the principle of the operation of the axial direction pore type coreless vibrator motor using the eccentric rotor R 5 , referring to FIG. 20, when a DC voltage by a power source (not shown) is applied to a pair of main and sub brushes 7 and 7 , at the position of 0 degree, current flows in a direction indicated by arrows in the left and right winding type armature coils 3 and 3 via the printed wiring commutator and rotational torque in a direction indicated by arrow A is generated according to Fleming's left-hand rule. When the rotation proceeds to a degree of 60°, rotational torque in a direction of arrow A is generated to the printed wiring armature coil C 3 and the winding type air-core armature coil 3 . Anti-torque preventing rotation is not generated at other positions. Thus, as long as the power is supplied, the rotation continues cyclically. As two armatures are always electrically connected in three-phase three armatures, torque is improved compared to three-phase two armatures where one armature is open.
In the above embodiments of the present invention, it is obvious that various modifications can be made to detailed contents of the size, shape and structure thereof s long as the scopes of claims are met.
Also, it is preferable that, in integrally forming the resin holder 2 a in the printed wiring commutator device, a part of copper pattern portion which is a boundary with the resin portion is made wider by mold so as not to be shorted.
As described above, in the compact vibrator motor having the above structure according to the present invention for obtaining vibrations with only an eccentric rotor, the connection between each end portion of the armature coil and the commutator is made easy, the armature coil can be easily fixed when installed to be inclined, particularly, mechanical noise can be reduced without using a sintered oil-storing bearing, the number of parts can be reduced by using the commutator as a bearing, and an eccentric rotor having a resin bearing portion which is advantageous in costs is available.
Also, to solve the problems of the conventional mold type rotor, in configuring a non-mold type flat rotor, the resin holder having a bearing portion and the air-core coil position determination guide are arranged using the printed wiring commutator device so that a sufficient maintenance intensity is secured and the property of sliding and the amount of eccentricity can be compatibly maintained.
Further, as the printed wiring coil is formed in the eccentric printed wiring commutator device forming the non-mold type flat rotor without sacrifice of the thickness, the problems or properties of the conventional mold type rotor can be solved. Thus, a low postured eccentric rotor, that is, a thin type vibrator motor can be provided. Also, using the advantages of the printed wiring commutator device, a method of manufacturing a non-mold type flat rotor capable of mass production can be provided.
In detail, the vibrator motor according to the present invention has the advantages as follows.
According to the invention, as the end connection portion does not overlap the armature coil, the end portion is easily hooked as well as welded. Large vibrations can be generated to the rotor itself during rotation by the winding type armature coil and the eccentric weight exhibiting density of over 3 which are integrally formed to be eccentric and in a non-mold manner.
According to the invention, as a metal bearing is not needed, production costs can be lowered.
According to the invention, a thin cored vibrator motor can be obtained.
According to the invention, the armature coil wound around the non-magnetized salient pole becomes a pseudo coreless winding to contribute to the rotational torque. Cogging torques of two magnetized salient poles facing each other are offset and decreased and the amount of movement of the center of the eccentricity accentuating non-magnetized salient pole is increased.
According to the invention, as the printed wiring commutator device itself is eccentric, the eccentric air-core coil position determination guide or the eccentric weight is easily installed.
According to the invention, as the printed wiring commutator device becomes a main frame, the air-core armature coil position determination guide and the resin eccentric weight can be maintained at high intensity.
According to the invention, as the resin bearing holder, the air-core coil position determination guide, and the resin eccentric weight can be formed through a single injection-molding, efforts rendered in the process can be reduced and, as all the above elements are connected together, a high intensity can be maintained.
According to the invention, as the resin bearing holder can be maintained at a high intensity, impacts in the latitudinal direction with respect to the eccentric rotor can be endured.
According to the invention, a thin axial direction pore type coreless vibrator motor can be provided.
According to the invention, due to at least one armature coil formed in print-wiring, an eccentric rotor having three-phase overlapped armature coil is available with sacrifice of the thickness. As a conductive body contributing to torque is increased, an effective eccentric rotor is obtained.
According to the invention, as the number of windings of at least one armature coil formed in print-wiring increases, more effective eccentric rotor is available.
According to the invention, an eccentric rotor having a large amount of eccentricity, without a metal bearing, is possible and a flat vibrator motor having the rotor is possible.
According to the invention, mass production of eccentric rotors is possible.
According to the invention, the mass production of eccentric rotor is possible.
According to the invention, a high density eccentric weight can be used so that a motor generating greater vibrations is obtained.
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An eccentric rotor includes an eccentric printed wiring commutator device having first and second surfaces, an expanded fan shape when viewed in a plane, a central hole for shaft installation, and a plurality of segment patterns at a periphery of the first surface; a wound, non-molded air-core armature coil incorporated in an air-core armature coil position determination guide protruding from and eccentric at the second surface of the printed wiring commutator device; an end connection portion located at an outer circumferential portion of the printed wiring commutator device for latching an end portion of the wound armature coil within a range not deviating from a turning circumference and simultaneous electrical connection with the segment patterns is possible, and not overlapping the wound armature coil when viewed in a plane; a resin bearing holder inserted in the shaft installation hole with a first part protruding toward the segment pattern and, simultaneously, a second part extending toward the second surface of the printed wiring commutator device; and a resin eccentric weight having a density exceeding 3 installed at a fan-like arc-shaped portion of the printed wiring commutator device. A vibrator motor includes the eccentric rotor, a housing accommodating the eccentric rotor, and a magnet for applying a magnetic force to the eccentric rotor.
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BACKGROUND OF THE INVENTION
The invention relates to a frequency-shift-keyed (FSK) data receiver comprising a mixer stage in which a received FSK signal, having a carrier frequency f c which is frequency-modulated by a data signal to produce a given frequency swing. Δf, and a local oscillator signal produced by a voltage-controlled oscillator with a signal frequency f L located within the band of the receiver, are mixed. Relative to the carrier signal frequency f c , the local oscillator frequency is shifted through a given value δf. A bandpass filter is connected to the mixer stage, a detection circuit is connected to the bandpass filter for recovering the data signal from the sum and difference-frequency signals Δf±δf produced by the mixer stage, and an AFC control loop is connected between the detection circuit and the voltage-controlled oscillator.
Such a receiver is disclosed in United Kingdom patent application No. 8132181, to which U.S. Pat. No. 4,523,324 corresponds. In this receiver the sum and difference signal frequencies are filtered in separate filters after having passed the bandpass filter and are applied to a differential amplifier. This differential amplifier checks whether at that moment a high or a low signal level of the transmitted data signal is received.
The AFC control loop comprises a mixer stage to which a separate oscillator having a signal frequency equal to the frequency swing Δf is connected. The sum and difference signal frequencies applied to this mixer stage are down-transformed, whereafter the signal component having the given frequency value δf is obtained with the aid of a low-pass filter. This signal component is converted into a control voltage for the voltage-controlled oscillator with the aid of a frequency-voltage converter.
This receiver has the disadvantage that at least three sharp filters are used which, for production in accordance with integrated circuit techniques requires many external capacitors and a correspondingly large number of connections. In addition, the AFC loop comprises an additional oscillator. In the receiver a controllable intermediate-frequency amplifier having a large dynamic range is required, which necessitates a large amount of current, which makes integration still more difficult. AM noise is not suppressed. Finally, the AFC loop used does not work satisfactorily with small input signals which however still have an adequately large S/N ratio to enable adequate detection. The reason for this AFC failure is that for such small input signals the loop can lock onto several frequencies, more specifically onto noise signals.
In certain applications such as pagers very severe requirements are imposed on the sensitivity, the selectivity and the consumed power. Thus, in England a sensitivity of 10 μV/m, a selectivity of -65 dB at ±25 kHz and a power dissipation less than 6 mW is required for an aerial having a length of 3 cm in the frequency band for pagers from 148-152 MHz.
SUMMARY OF THE INVENTION
The object of the invention is to provide a novel FSK data receiver arrangement which eliminates these disadvantages; and more specifically, a receiver which has a high selectivity, combined with a wide pull in-range for the AFC control loop and which is easy to integrate.
According to the invention, an FSK data receiver as described in the first paragraph includes a means for emphasising the energy content of signals having frequencies located near the ends of the passband of the receiver, over signals having intervening frequency signals; and an integrator coupled to the means for emphasising the energy content of signals, having frequencies located near the ends of the passband, for generating an AFC control signal for the voltage-controlled oscillator.
This has the advantage that only one filter must be provided, which can be a very narrow-band filter. Further, the AFC loop still has a wide pull-in range, is simple to integrate and enables a high signal-to-noise ratio.
Preferably, the energy-emphasizing means comprise the bandpass filter and the detection circuit. The bandpass filter has two peaks located around the signals having frequencies located near the ends of the passband, and the detection circuit comprises a limiter connected to the bandpass filter and a frequency-voltage converter having such a characteristic that the absolute value of the output voltage for the signals having frequencies located near the ends of the passband of the bandpass filter exceeds the output voltage for the signals having intervening signal frequencies.
Such a filter and detection circuit can be produced in a simple manner.
According to a different embodiment, the energy-emphasizing means comprise the detection circuit and a non-linear detector arranged in the AFC control loop. The detection circuit comprises a frequency-voltage converter having such a characteristic that the absolute value of the output voltage for the signals having frequencies located near the ends of the passband of the bandpass filter exceeds the output voltage for the signals having intervening signal frequencies.
Making such circuits is at least equally simple as the double-peaked filter.
Finally, in still another embodiment, the means comprise the detection circuit, which comprises a frequency-voltage converter having an amplitude and phase characteristic which is a non-linear function of the frequency. This characteristic is mirror-symmetrical relative to a reference point and the AFC control loop comprises a rectifier arranged between the converter and the integrator.
The invention and its advantages will be described in greater detail by way of example with reference to the embodiments shown in the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block circuit diagram of the FSK data receiver according to the invention;
FIGS. 2a-d show characteristics of signals in the receiver of FIG. 1 without the use of the measures according to the invention;
FIGS. 3a-d show characteristics for signals in the receiver of FIG. 1, when a special bandfilter is used;
FIGS. 4a-d show characteristics for signals in the receiver of FIG. 1 if a non-linear rectifier is used in the AFC loop;
FIGS. 5a-d show characteristics for signals in the receiver of FIG. 1 if both a special bandpass filter and a non-linear rectifier circuit are used; and
FIG. 6 shows an example of the passband characteristic of the special bandpass filter according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The FSK data receiver shown in FIG. 1 is arranged for receiving a carrier signal which is frequency-modulated by a data signal, for example a data signal of 512 b/s frequency-modulating a carrier signal having a frequency f c of 150 MHz with a frequency swing Δf of 4.5 kHz. Such an FSK signal having the frequencies f c ±Δf determined by the logic signal values of the data signal is applied, after reception by the aerial 1, to a mixer circuit 2. A signal produced by a local oscillator 3 and having a frequency f L is also applied to this mixer circuit. The frequency f L is chosen such that it is frequency-shifted through a given small value δf relative to the carrier frequency f c , so that it is well within the band of the receiver. δf has, for example, a value equal to 750 Hz.
The sum and difference-frequency signals Δf+δf and Δf-δf are formed in the mixer circuit 2. These signals are consequently mutually shifted through a frequency of 2δf. Because of this frequency shift it is possible to recover the logic values of the data signal in a simple manner.
To that end, these signals are applied to a detection circuit 5 after having been filtered in a bandpass filter 4. This detection circuit comprises a first limiter 6, a frequency-voltage converter 7 and a low-pass filter 8. The limiter 6 is used, among other things for suppressing AM noise. The frequency-voltage converter is, for example, a Foster-Seeley discriminator as is described, for example, in the article "Foster-Seeley Discriminator" by C. G. Mayo and J. W. Head, published in Electron. Radio Egnr. February 1958. Such a discriminator has an amplitude and phase characteristic which is a linear function of the frequency. If the reference point of the characteristic is chosen at the frequency Δf, the points on the characteristic curve for the frequencies are located plus and minus δf symmetrically relative to this reference point; and at these frequencies +δf and -δf, equal but opposite output voltages compared with the voltage level determined by the reference points are supplied.
These output voltages are filtered by the low-pass filter 8 with a frequency at the breakpoint of approximately 250 Hz for a 512 b/s data signal. The data signal thus recovered is applied to an output 9 of the receiver.
In addition, the data receiver comprises an AFC control loop including an AFC circuit 10 connected between the output 9 and a control input 11 of the voltage-controlled oscillator 3, for having the voltage-controlled oscillator vary with the frequency drift of the input signal. This control circuit 10 comprises a detector 12, a reference voltage source 13, a differential amplifier 14, an integrator 16 and optionally a second limiter 17. A signal produced by the detector 12 is applied together with the reference voltage produced by the reference voltage source 13 to the differential amplifier 14, which has a current output 15. In the differential amplifier the voltage difference between the input signals is determined and converted into an output current I AFC proportional thereto. This output current I AFC is applied to the integrator 16. The output voltage of integrator 16 is applied as a control signal to the control input 11 of the voltage-controlled oscillator 3, through the optional second limiter 17.
In FIG. 2a, the current I AFC supplied by the differential amplifier 14 is shown as a function of the frequency difference between the frequency of a received signal and the signal frequency f L produced by the voltage-controlled oscillator 3. Let it be assumed that the bandpass filter 4 has a straight transmission characteristic as shown in FIG. 2b and that the second detector 11 is a rectifier having a linear rectifier characteristic denoted by |V 1 | in FIG. 2c. In this Figure, the solid line applies to small input signals and the broken-line portion indicates the deviation of the solid line for large input signals.
The zero point of the frequency axis is located at the reference frequency Δf determined by the frequency-voltage converter, so that δf is plotted along the frequency axis.
The zero-crossing point of the current axis is determined by the magnitude of the desired value of the frequency δf, to which normally the voltage-controlled oscillator 3 (VCO) above or below the carrier frequency is tuned. In this embodiment a tuning above the carrier frequency, more specifically +750 Hz is opted for. As will be obvious from this Figure, the current I AFC produced is negative for mixed frequencies located between -750 Hz and +750 Hz and the current I AFC is positive for small signals for mixed frequencies between +750 Hz and approximately 1200 Hz. The voltage V AFC produced by the integrator 16 in response to these currents controls the voltage-controlled oscillator 3 such that the frequency of the oscillator is up-controlled for a negative control voltage and is down-controlled for a positive control voltage. As a result thereof the frequency of the oscillator 3 is always adjusted to the desired value of δf. The integrator 6 ensures that not residual error remains.
In order to realise a largest possible signal-to-noise ratio (S/N) and a best possible channel separation, the bandwidth of the bandfilter 4 is chosen as low as possible. This has the result that if no transmitted signal is received by the receiver and consequently only noise is received within the band, the receiving level is so low that the current I AFC applied to the integrator 6 is below the reference level and is consequently negative, as is shown in FIG. 2d. Moreover, in the example shown in FIG. 2a this also occurs when δf is frequency-shifted through more than 1250 Hz in the positive direction relative to Δf. In both cases the frequency of the VCO 3 is adjusted to higher values of δf and the AFC control loop is shifted to its highest frequency value. Consequently, the control loop cannot be pulled in any more by a transmitted signal as the loop is outside the pull-in range.
To obviate this, without widening the passband of the filter, and therefore without decreasing the signal-to-noise ratio, a bandpass filter 4 is used whose transmission characteristic has two peaks located near the ends of the passband of the filter as is shown in FIG. 3b. Because of these two peaks in the passband the amplitudes of signals having frequencies located near the ends of the passband are larger than the amplitudes of signals having intervening frequencies; and more specifically, larger compared with signals having frequencies located near δf=0.
These signals are limited in the hard limiter 6. As is known, such a limiter has the property to benefit signals having the largest amplitude at the cost of signals having a smaller amplitude. The ratio in which this occurs is the so-called "capture ratio". This means that, after having passed the limiter 6, the ratio of the number of frequency components located at the ends of the passband relative to the frequency components in the center of the band (δf =0) is increased with respect to the ratio of the signals applied thereto.
In the frequency-to-voltage converter 7 frequencies located near the center of the band are converted into a voltage having a much smaller amplitude than frequencies located near the ends. After rectification in the detector 12 the average value of the current I AFC applied to the integrator 16 has increased, because of the joint action of the special bandpass filter 4, the limiter 6 and the frequency-voltage converter 7 relative to the average value for a bandpass filter having a flat transmission characteristic.
A bandpass filter suitable for this purpose is realized by means of the cascade-arrangement of two differently adjusted Sallen and Key filters, whose transmission characteristics are shown in FIG. 6. As this figure shows, the lowest point between two peaks of the transmission characteristic is located at a chosen Δf of 4.5 kHz, and the peaks of a δf of 750 Hz chosen associated therewith are selected at 3.75 and 5.25 kHz. The difference in level at 4.5 kHz and at 3.75 and 5.25 kHz, respectively is ≈3 dB. The higher average value of the current I AFC obtained with the aid of this filter and applied to the integrator 16 is shown in the FIGS. 3a and 3b, both for the case that the oscillator frequency has such a value that the signal mixed with a received signal is located outside the band, so for a δf larger than approximately 1200 Hz, and for the case in which there is no input signal and only white noise is received.
As these Figures clearly show the average value of the signals has increased, more specifically to such an extent that the current I AFC applied to the integrator 6 is located above the zero level for both the above-mentioned cases. Consequently, the integrator 6 applies a positive control voltage V AFC to the oscillator 3 in response to which the frequency of the oscillator is adjusted downwards.
If no input signal is present, the oscillator will be controlled to the desired value of δf, in this case +750 Hz, and will be maintained without residual error. If no input signal is present, then the frequency of the oscillator is controlled down to such an extent that the oscillator clips, so that when off-set occurs between the transmitting frequency and the frequency of the VCO, for example due to drift, the desired signal is always located within the passband of the filter. The pull-in range of the AFC-loop is in principle extended upwards to infinity because of the use of the special bandpass filter 4, without the signal-to-noise level of the receiver being reduced.
When the oscillator 3 has a control range which in the negative direction passes the frequency of the unstable setting point at -750 Hz, the limiter 17 shown in FIG. 1 as a broken-line block is indispensable. This limiter limits the control voltage V AFC produced by the integrator 6 to such a value that the maximum frequency offset between the oscillator 3 and the signal to be received can never become larger than -750 Hz, for example -720 Hz. In this way, a perfect operation of the AFC-loop is ensured in all circumstances without loss in sensitivity.
The width of the pull-in range of the AFC-loop after said measures have been applied is only shown in the FIGS. 5a and 5d, denoted by L. This pull-in range also holds, however, for the FIGS. 3a, 3d, 4a and 4b.
Instead of using a special bandpass filter 4, an increase in the average value of the current I AFC applied to the integrator 6 on receipt of noise can alternatively be affected by using other measures, more specifically by using in the detector 12 a rectifier having a non-linear rectification characteristic instead of a rectifier having a square-law characteristic. This is shown in FIG. 4c by means of |V 2 |.
As has already been described in the foregoing, the frequency-voltage converter 7 produces converter output signals with an amplitude which increases and decreases linearly from a value of zero corresponding to δf=0 (for example, an input noise component having a frequency equal to f L ), to values corresponding to their noise components. As these signals are rectified with a square-law characteristic in the detector 12, the amplitude of large-amplitude signals are given preference over signals having a small amplitude. As a result thereof, the current I AFC applied to the integrator 6 has the value shown in FIG. 4a as a function of the frequency δf when an input signal is received and has the characteristic shown in FIG. 5d when only white noise is received. By giving the higher signal frequencies the advantage due to the joint operation of the frequency-voltage converter 7 and the detector 12, an increase in the average value of the current I AFC is again realized without deteriorating the signal-to-noise ratio. The signal value on receipt of white noise is consequently again located above the zero level and the pull-in range for positive δf is in principle again increased to plus infinity.
Instead of a square-law rectification characteristic it is alternatively possible to use detectors having a higher order rectification characteristic, whereby said effect is still further increased.
It is, however, alternatively possible to use a rectifier having a linear characteristic and to use a frequency-voltage converter 7 having a non-linear, for example a square-law characteristic, mirror-inverted around the reference point Δf, but together with a bandpass filter 4 having a flat transmission characteristic. The results shown in the FIGS. 4a and 4d are also obtained with a frequency-voltage converter 7 having a square-law characteristic.
It will be obvious that all combinations from the set given by a specific bandpass filter, a non-linear characteristc of the frequency-voltage converter and a non-linear rectification characteristic of the detector 12 can be applied. Thus FIGS. 5a and 5d show the result of a receiver comprising the special bandpass filter 4 (FIG. 5b) and a square-law rectification characteristic (FIG. 5c) of the detector 12. The higher average value of the current I AFC applied to the integrator 6 obtained by the joint operation is clearly shown in these Figures as is also the increase of the noise level near δf=0. However, because of its comparatively low value this last increase is not objectionable. An advantage of the large positive current value of I AFC for noise is a shorter settling time of the AFC-loop after switch-on of the receiver.
The additional space obtained may, however, alternatively be used to increase the selectivity of the receiver by somewhat reducing the bandwidth of the bandpass filter.
Because of the fact that the receiver has only one single filter it can be easily produced in integrated circuit technique.
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For receiving frequency shift keyed data, a local oscillator generates a signal which is frequency shifted through a fixed frequency relative to the carrier signal, and is mixed with the received FSK signal. A circuit processes the mixer output to emphasize the energy content of signals located at the ends of the receiver passband, over signals located toward the center of the pass band. The output of that circuit is integrated to provide the AFC signal to the voltage-controlled local oscillator.
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[0001] The present invention relates to web-based service delivery systems and, more particularly, to user customizable website templates with intelligent monitoring capability.
BACKGROUND OF THE DISCLOSURE
[0002] The growth of uses of the internet continues as new services are offered to users. More and more providers of goods and services realize that their customer base can be expanded from a local geographic catchment, to a national or even a world wide clientele.
[0003] A difficulty, particularly for smaller firms, is how to arrange the web-based promotional infrastructure required, to alert that wider potential clientele, to what the firm has to offer.
[0004] It is an object of the present invention to address or at least ameliorate some of the above disadvantages.
SUMMARY OF THE INVENTION
[0005] Accordingly, in a first broad form of the invention, there is provided an integrated web-based system; said system including:
(a) code tangibly embodied on servers and databases, (b) web-based templates generated by said code in a first language, (c) a first web-based module included in said code for customization of a said web-based global master template (built around the Vendor specific marketing campaign) into a website to suit a registered third party Vendor, (d) a second web-based module included in said code for translation of a selected said website into at least a second language translation undertaken by a translation service outside of the system, (e) a tracking facility in which a said registered third party Vendor receives statistical data of contact interaction with a said website of a third party Vendor Partner.
[0011] Preferably, said servers and databases are maintained by a Central Agency.
[0012] Preferably, a said global master template is structured using Adobe® Flash®.
[0013] Preferably, visibility of navigation items within a said website is controlled by changing settings within an xml file.
[0014] Preferably, text elements of a said website are extracted through xml files; changes of text elements being effected by means of changes to elements in a corresponding xml file.
[0015] Preferably, third party Vendors are registered with said Central Agency on payment of a fee.
[0016] Preferably, a customized website of a said registered Vendor may be further modified by a Vendor's Country Campaign Manager to include a subset of websites for use by registered Vendor Partners of said Vendor.
[0017] Preferably, text elements contained in text fields of a said website are inserted into fields of a spread sheet; said text elements translated from said first language into a selected second language; said second language text elements transferred from said spread sheet to text fields of said website.
[0018] Preferably, a said registered third party Vendor's website is structured so as to allow a said Vendor to select a language other than a primary language of said Vendor's global master template; said template then automatically displaying in said other language.
[0019] Preferably, said Central Agency generates emails to recipients nominated by said registered Vendors and said Vendor Partners; said emails including links to websites of said Vendors and Vendor Partners.
[0020] Preferably, said tracking includes capture and storage of details of said recipients nominated for receipt of emails by said registered Vendors and said registered Vendor Partners.
[0021] Preferably, said tracking includes formation of a profile of use of a said website; said profile of use including statistical data made available to said registered Vendors and Vendor Partners.
[0022] Preferably, a said profile is a function of interactions with various elements of a Vendor website according to matches with criteria established by a said Vendor's Country Campaign Manager.
[0023] Preferably, a said Campaign Manager is alerted to a matching of said criteria by an email generated by said Central Agency.
[0024] In another broad form of the invention, there is provided a method of transforming a Vendor website template into a region specific website; said method including the steps of:
(a) constructing a master website template using Adobe Flash®, (b) controlling visibility of navigation items of said template by changing settings within an xml file, (c) displaying text content by abstracting text elements through a said xml file,
[0028] Preferably, page headings, button backgrounds and colour scheme for said Vendor specific website are abstracted from a said xml file.
[0029] Preferably, a said Vendor specific website is provided with reserved space for Vendor Partner logo and Vendor Partner contact page.
[0030] In another broad form of the invention, there is provided a computer implemented method of structuring web-based marketing campaigns; said method including a Central Agency; said Central Agency:
(a) providing web-based marketing campaign master templates for a Vendor in a first language for customizing into region specific websites, (b) providing web-based modules enabling configuration and translation of a said market specific website into at least a second language, (c) providing tracking of accessing by visitors of configured said market specific websites, and
wherein said Central Agency maintains servers and databases for storage, configuration and display of said templates and for said tracking.
[0034] In still another broad form of the invention, there is provided code of a web-based system implemented on servers and databases maintained by a Central Agency; said code executing steps for generating web-based templates for websites in a first language; said code including a web-based module for translation of a selected one of said templates into at least a second language.
BRIEF DESCRIPTION OF DRAWING
[0035] Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:
[0036] FIG. 1 is a schematic layout of the components of the web based system of the invention,
[0037] FIGS. 2 to 4 are flow charts of processes associated with one of the components of the system of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0038] The present invention provides Vendors with a powerful method of advertising products and services and attracting potential customers. In addition the system of the invention provides Vendors with an intelligent tracking facility which informs Vendors of levels of propensity to buy a product or service by persons accessing a Vendor's website, allowing effective follow up.
[0039] In this specification, the following terms are defined as:
[0000] Elastic Digital—the name used in the drawings for the Central Agency of the web-based system of the invention.
Elastic Connect—A collective term encompassing the various components which make up the web-based system.
Global Campaign—A website which is built to be run globally (across all regions and languages).
Flash—A browser plug in built by Adobe which allows websites to be a lot more dynamic and interactive compared to a standard HTML site.
Tracking Data—Each interaction with a website is tracked accordingly. This data is them fed into the enterprise database for reporting purposes.
Country Campaign Manager—Vendor's marketing manager for a given country running a global campaign. It's their responsibility to ensure they update content to suit their specific language and country.
Vendor—Usually, the manufacturers of goods or services who distribute their goods/services via a channel sales model. For example, IT Vendors usually distribute their products first through a distributor, then through their own Vendor Partner community (registered resellers).
Vendor Grid—A Vendor branded version of a Global Campaign which a Vendor's Vendor partner community can access and register to run any of a Vendor's available campaigns.
Vendor partner—a registered partner of a Vendor who is allowed to market and sell good/services provided by the Vendor.
XML file—XML (Extensible Markup Language) is an electronic file format which can be used to structure data. Providing the application reading the XML file knows how it is formatted, the application can retrieve specific data elements from the XML file as it is needed. For the Global Campaigns of the web-based system of the invention, the data embedded in the XML file is the text content for the Global Campaign.
[0040] With reference to FIG. 1 , the web-based system 10 of the invention includes a Central Agency which maintains servers and databases 12 on which the system of the invention is implemented. Through program code stored on these servers and databases, the Central Agency develops website marketing campaigns 14 “Global Campaigns”, in effect master templates of websites. The websites are structured in a primary language, for example English, to suit various technology products or services for use by Vendors. These templates are built using Adobe Flash®, giving the benefit of a greater level of interactivity in both 2D and 3D, as well as providing a website, so constructed as to have consistency of appearance across all known internet browsers.
[0041] The Central Agency further provides two web-based modules 16 “Elastic Locale” which includes as well as customization tools, a facility to populate a spreadsheet of the text in all the text fields of a Vendor global master website. This spreadsheet may be provided to a third party agency which returns the spreadsheet with all the text translated into the desired secondary language. These translated text items are then pasted back into the text fields of the website.
[0042] This module also allows Country Campaign Managers to customize a Vendor's global campaign template to suit the Country Campaign Manager's region. In a second module 18 “Elastic Grid”, sites based on the Vendor's web site, can be propagated through XML files. The subset “grid” of web sites is made available to registered “Vendor partners”, users with some commonality of purpose, for example the promotion of a particular product or service within a particular language group or a particular type of potential purchasers of the product or service. These sites are so structured that a registered Vendor may select a language other than the primary language of the Vendor's global master template and the template will automatically display in that other language.
[0043] A further feature of the system of the invention, is the tracking system (referred to above) which is implemented by the Central Agency and provides data 22 “Elastic Profile”, relating to the accessing of the Vendor or Vendor Partner websites 24 .
[0044] A master website template, (referred to as a “Flash Piece”) provided by the Central Agency (within Flash), allows for the customization of the template website to suit third party users, registered Vendors and Vendor partners, in the following ways, without the need to modify any of the template's code:
1. All navigation items (as part of a menu) may be made visible or invisible by changing a setting within an xml file. This allows certain sites to be built using the entire site map, or a site to be built from a subset of the main site (containing only a few navigation items). 2. All text elements are abstracted through xml files—this means that the Flash Piece itself looks to the xml file for the content to display in any given text field. To change the content of the site simply involves the changing of elements within the corresponding xml file. This updating of content is automated through the customizing module (so that the xml file doesn't have to be modified manually). 3. Personalisation of the site is effected through the use of animation or standard text elements—if a contact (visitor accessing a website) arrives at the site by clicking on a personalised email (sent from the Central Agency to contacts nominated by registered third party Vendors or their registered partners, the contact's details are firstly captured and stored on the Central Agency's database. Personal details of the contact can subsequently be extracted from the database and passed onto the Flash Piece via FlashVars (variables used by Flash). This personalisation can be as simple as “Hi David” when the contact first enters the site, right through to the use, where appropriate, of the contact's company name in animation graphics. The site may also pre-populate any form that is displayed on the site with the contact's details. 4. Certain key elements of the site, such as the site background, page headings, as well as button backgrounds, are configured in a way that the site may pull a desired alternative colour scheme from an xml file. This means that changing the colour elements in the xml file changes the site's appearance to match a Vendor partner's corporate style guide. 5. The master template, or Flash Piece, is built with co-branding in mind. This means that there is always a reserved space for a Vendor partner's logo and contact page, along with a customisable Vendor partner page (where the Vendor partner can choose what content they'd like displayed). All these elements are configurable through xml files (along with the ability to change the colour scheme (as listed in point 4 ). This allows easy automation through the Elastic Grid.
[0050] The components or modules making up the web-based system of the invention will now be further described with reference to the flow charts of FIGS. 2 to 4 .
[0051] Elastic Locale— FIG. 2 .
[0052] As shown in FIG. 2 , the Elastic Locale component or module of the system, provides the tools for a Vendor's Country Campaign Manager (Campaign Manager) to customize the appearance and language of a Global Campaign website provided by the Central Agency. The module provides a system for a Campaign Manager to create a particular version of a Global Campaign. This may involve just the removal of certain pages of the template website and modifying a small amount of content, right through to the conversion of the entire site from the primary, or original language of the site, to any other language.
[0053] The Campaign Manager is enabled to log into the Elastic Locale module hosted by the Central Agency and select a desired language 26 . The system then builds a modified version 28 of the site based on the Global Campaign 14 . The Elastic Locale module 16 provides for translation assistance into any of a large selection of languages (including double byte languages such as Simplified and Traditional Chinese, Korean and Japanese).
[0054] Translation is completed by the Campaign Manager navigating through the site map and pasting the translated text elements into the corresponding fields 30 .
[0055] Once the Campaign Manager is satisfied with the customization, the website is submitted to the Central Agency for any adjustments and approval. The site is tested for the tracking functionality described above and the Campaign Manager notified that the site has been made “live” and ready for use. The Campaign Manager is then able to begin generating traffic to the website, trough links embedded in web banners and in emails sent by the Central Agency to nominated recipients at the request of the Campaign Manager. As the site is visited, data tracking builds a profile of site visitors and usage based on site visitor's interaction with the various elements of the site. This profile is matched with a set of criteria established by the Campaign Manager before the campaign is launched. If these criteria are met, the Campaign Manager is alerted by an email generated by the system.
[0056] Elastic Grid— FIG. 3 .
[0057] This module 18 is a tool provided to Vendors enabling them to host on their Vendor websites a subset (“grid”) of Vendor Partner based websites. As shown in the flow chart of FIG. 3 , either standard master website templates provided by the Central Agency, or those modified by a Vendor's Campaign Manager by means of the Elastic Locale described above, are loaded onto a respective Vendor's Grid. Interested parties may then select and apply to register to use one of the grid campaign websites.
[0058] If the application is approved, the applicant, on payment of a fee, becomes a registered Vendor Partner. Once registered, the Vendor Partner is then enabled to further modify the content and appearance of their chosen grid campaign website. When this modification step is complete, the Central Agency reviews the site, making any adjustments if required.
[0059] Once both the Vendor Partner and the Central Agency are satisfied with the final form of the website, the Vendor Partner may load a contact list onto the site. The Central Agency generates emails based on this contact list, inviting recipients to the Vendor Partner website. Visits to the site by email recipients, is tracked by the Central Authority for building a usage profile against criteria preset by the Vendor Partner and the Vendor Partner is alerted to the Visitor's interaction with the Vendor Partner website.
[0060] Emails include a personalised URL (Uniform Resource Locator) containing the recipients unique identifier. When a recipient “clicks” on a link to the Vendor partner's website embedded in the email, the Central Agency's database checks the unique identifier and retrieves any personal stored data it has on that recipient and passes it into the website (via FlashVars). Thus, if for example, the first name of the recipient is known, the website may display a personal salutation.
[0061] Elastic Profile— FIG. 4 .
[0062] This module of the system allows a Vendor, the Vendor's Campaign Manager or a Vendor Partner to assess the effectiveness of a website. When logged into the appropriate Central Agency site, the Elastic Profile module pools all campaign tracking data and displays statistical data of visits to the Vendor or Vendor Partner's website. Visits made as a result of emails are identified, allowing follow up by the Vendor or Vendor Partner. The statistical information may be manipulated to filter for a selected time period or geographic area for example. This module also produces the profile which is used by the Elastic Grid.
[0063] The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.
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Internet based provision of goods and services continues to proliferate as providers of goods and services realize that their customer base can be expanded from a local geographic catchment, to a national or even a world wide clientele. The present invention provides an integrated web-based system which includes the provision of web-based templates generated by said code in a first language, a first web-based module for customization of a web-based global master template into a website to suit a registered third party Vendor. The system further provides a second web-based module for translation of a selected website into at least a second language. Also provided is a tracking facility in which a registered third party Vendor receives statistical data of contact interaction with a website of a third party Vendor Partner.
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This is a continuation of application Ser. No. 07/439,616, filed Nov. 20, 1989, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
FIELD OF THE INVENTION
The invention relates to the field of substituted guanosine derivatives and methods for their production.
BACKGROUND OF THE INVENTION
One of the recurring problems in biochemistry is the availability of raw materials. Not surprisingly, of particular interest are raw materials corresponding to the basic building blocks fundamental to biochemistry, such as nucleosides and nucleotides of the naturally occurring purines and pyrimidines found in deoxyribonucleic acids (DNA) and ribonucleic acids (RNA). For the purposes of this application, a monomeric unit consisting of a nitrogenous heterocyclic base which is derived from either a purine or a pyrimidine, a pentose, and a molecule of phosphoric acid is known as a nucleotide. A nucleoside is the same as a nucleotide except for the absence of the phosphoric group. Experimentation on nucleosides or nucleotides may take the form of structural and functional analysis of derivatives such as the identification of potential antitumor activity associated with several 6-thioguanine nucleosides. See Hanna, et al, "A Convenient Synthesis of 2'-Deoxy-6-thioguanosine, Ara-Guanine, Ara-6-Thioguanine and Certain Related Purine Nucleosides by the Stereospecific Sodium Salt Glycosylation Procedure," J. Heterocyclic chem., 25, 1899 (1988).
Alternatively, nucleotides having specific properties may be inserted or attached to various probes or small sections of polynucleotides such that their effects may be monitored or their corresponding base pairs located For example, Chollet, "DNA Containing the Base Analog 2-Aminoadenine: Preparation, Uses, Hybridization Probes and Cleavage By Restriction Endonucleases," Nucleic Acids Research, Vol. 16, No. 1, 1988, p. 305, discusses that modified bases can be incorporated into DNA by chemical or enzymatic procedures. These modified 2'-deoxy-guanosine derivatives are shown to be good substrates for in vitro DNA polymerase I mediated enzymatic syntheses and allow for preparation of DNA containing 2-aminoadenine at defined sites on DNA strands. These probes having defined sequences are important tools for the identification and isolation of specific DNA sequences. The introduction of a stabilizing DNA duplex produced with the 2-amino-adenosine also allows for the use of more stringent hybridization conditions, and therefore increases the probes specificity for its target.
Of particular interest to researchers are modifications of the active bonding sites in purines and pyrimidines, such as, for example, those in the 6th and 2nd position in a purine. Unfortunately, the production of stable nucleosides has been historically plagued with a long list of problems. This is particularly true of 6-substituted guanosine nucleosides. These problems include cost, efficiency and specificity.
For example, Chollet et al discussed a route for synthesis of 2-amino-2-deoxyadenosine derivatives via 2-amino-6(N-pyridinium)purine-2'-deoxyribosides in a paper entitled "Synthesis of Oligodeoxyribonucleotides Containing the Base 2-Aminoadenine," presented at the second International Conference on "Synthetic Oligonucleotides in Molecular Biology," Uppsala, Sweden, 18-24 Aug. 1985, at page two thereof. As discussed therein, the formation of the 6-amino-substituted purine required treatment with ammonia in water and dioxane for three days, and resulted in the production of only trace amounts of 2-amino-2'-deoxyadenosine. The remainder of the product was a base protected form having an isobutyryl group on the nitrogen bonded in the 2nd position to the purine. This is the "N 2 " nitrogen. The isobutyryl group is extremely difficult to cleave from the N 2 due to its slow hydrolysis. In fact, complete cleavage of the N 2 isobutyryl group may require over 7 days of heating in concentrated aqueous ammonia. Id. at page 2, (NH 3 in H 2 O (min. conc. 25-30%) at 65° C. for 7 days). See also Gaffney et al., "The Influence of the Purine 2-Amino Group on DNA Conformation and Stability--II", Tetrahedron, Vol. 40, No. 1, p 3, 1984 at p 7. Obviously, such inefficient synthesis routes produce costly end products. Furthermore, the presence of the isobutyryl group is a limiting factor in the usefulness of protected amino purines because the isobutyryl group will prevent hydrogen bonding between base pairs. See also Gaffney and Jones "Thermo-dynamic Comparison of the Base Pairs Formed by the Carcinogenic Lesion O 6 -Methylguanine with Reference Both to Watson-Crick Pairs and to Mismatched Pairs," Biochemistry, 1989, 28, 5881 at 5883. (Incomplete deprotection occurs because the isobutyryl group N 2 protecting group is cleaved "exceptionally slowly, particularly in an oligonucleotide." Id.)
One remedy for the situation was reported directly above in Gaffney and Jones by the use of an N 2 -acetyl-O 6 -methyl-2'-deoxyguanosine. The N 2 -acetyldeoxyguanosine was synthesized by suspending deoxyguanosine in pyridine (40 mL per mmol deoxyguanosine) and 4-dimethylaminopyridine (0.1 mmol per mmol deoxyguanosine), triethylamine (11 mmol per mmol deoxyguanosine) and acetic anhydride (10 mmol per mmol deoxyguanosine) are added and the mixture is heated at 50° for 20 hours. This gives 2-N,3'-O,5'-triacetyl-2'-deoxyguanosine in 76% yield. However, while the N 2 -acetyl group is easier to remove than the isobutyryl group, it is still slow and problematic.
Furthermore, individual routes or mechanisms are required for each individual desired end product. That is to say that specific methodologies must be developed for each corresponding element to be added in the 6th position of a quanine nucleoside. For example, Hanna et al., supra describes a pathway for the conversion of a chlorinated purine to a 6-thioquanosine and to a guanine nucleoside or nucleotide. The process utilizes commercially available 6-chloropurine or 2-amino-6-chloropurine which were glycosylated to form the corresponding nucleoside intermediates. These are then converted into 2'-deoxy-6-thiopurine nucleosides by direct nucleophilic displacement. In addition to being very specific and therefore limited in applicability, the synthesis of Hanna et al is quite time consuming. (over 18 hours to obtain the 6-chlorinated nucleoside (61% yield) and an additional approximately 3 hours thereafter.)
Another route was suggested in Reese et al. "The Protection of Thymine and Guanine Residues in oligodeoxyribonucleotide Synthysis," J. Chem. Soc. Perkin Trons. I, 1984, 1263 wherein 2-Deoxyguansine is converted in five steps into its 6-O-(2-nitrophenyl)-2-N-phenylacetyl and crystalline 6-O-(3,5-dichlorophenyl)-2-N-phenylacetyl derivatives, respectively, in 39 and 42% overall yields, respectively. The 6-O-(2-nitrophenyl derivative was produced by a multistep process in which triethylamine was added to a stirred suspension of 3',5'-di-O-methyoxyacetyl-2'-deoxyguanosine and mesitylene-2-sulphonylchloride in dry acetonitrile. After reaction, cooling, extraction, drying and fractioning under pressure, the resulting sulfonated derivative was dissolved in pyridine and diisopropylethylamine and 2-nitrophenol. This mixture was then heated under reflux for 1 hour, cooled, and separated. After several more steps including a series of washing and elutions; and a reaction with 2,6-Lutidine and phenylacetylchloride in acetonitrile, the aforementioned compound was produced.
A modified procedure was used to produce the 6-O-(3,5-dichlorophenyl) derivative. This process, however, also involved the use of Mesitylene-2-sulphonylchloride to produce a first, sulfur continuing guanine nucleoside derivative. See Id. at 1268.
Also of interest with regard to substituted guanine nucleosides is a paper by Bridson et al., "Acylation of 2',3',5'-Tri-O-acetylguanosine," J.C.S. Chem. Comm., 1977, 791 which cites the Reese et al. paper discussed above. Accordingly, an unreacted guanosine was reacted with an unsubstituted acetic anhydride in a solvent of pyridine to give 2',3',5'-tri-O-acetylguanosine. This compound can undergo further acylation in the N 2 position to yield the tetra acetyl derivative. Acylation of the 6th position, however required the treatment of triacetyl derivative with an excess of 2,6-dichlorobenzoyl chloride in a pyridine solution which yields the O(6)-aroyl derivative. This derivative appears, however, to be unprotected in the N 2 position. In another procedure, the tri-acetyl derivative is reacted with methanesulphonyl chloride in a pyridine solution to yield the O(6)-mesyl derivative. The paper left open the question of why the tri-substituted guanine nucleoside is attacked by some acylating agents in the N 2 position and others in the O(6) position. They appear to have been unable to produce compounds substituted in both positions. The paper suggests the possibility of O(6)-acylguanosine derivatives being useful as intermediates and discusses the succeptability of the mesitylenesulphonyl derivative to nucleophitic substitution to yield a compound substituted in the 6th position with inter alia a secondary amine. However, the methods described are insufficient to actually convert the acylated products to other useful products and intermediates such as those of the present invention.
Another long standing problem in DNA/RNA research is the lack of a convenient methodology for adding substituted and N 2 protected quanine nucleosides into an oligonucleotide and subsequently removing at least the N 2 protecting group therefrom. This protecting group may serve as a block which prevents the formation of hydrogen bonds between corresponding base pairs on a plurality of oligonucleotides. Often the methodologies currently available are time consuming and may adversely effect the oligonucleoside. There has also been a lack of compositions which could make such a method practicable.
Another problem which is closely related is that of "marking" or "labeling". Marking or labeling is useful for identification of reaction pathways by permitting an easy way of determining the status of a marked or labeled compound. Labeled compounds may also be useful in a quantification of labeled reaction products. Unfortunately, synthesis of labeled compounds is often difficult, time consuming and expensive. When combined with the problems and technologies associated with the formation of substituted guanine nucleosides, it can be readily appreciated that the subject matter may become unworkable.
In addition, there remains a need for a quick, high-yield procedure which will allow for the production of a wide variety of 6-substituted guanine nucleosides and nucleotides from a single convenient protocol. Furthermore, there remains a need for the creation of shelf- and storage-stable guanosine reaction intermediates capable of being further processed to form desirable end products such as 2-amino-2'-deoxyadenosine or 2-aminoadenosine, or which may alternatively be used for the formation of other nucleoside derivatives. Therefore, there remains a need to produce labeling compounds which may be easily produced and easily incorporated into oligonucleosides.
SUMMARY OF THE PREFERRED EMBODIMENTS
Therefore, it is one object of the present invention to provide for compositions of matter and processes which may be useful for the formation of 2,6-diamino-9-[saccharide]purines or other 6-substituted N 2 amino guanine nucleosides.
It is another object of the present invention to provide compositions which may be directly inserted into DNA or RNA and thereafter, conveniently converted to useful forms.
It is another object of the present invention to provide compositions which are useful as fluorescent markers or labels.
It is another object of the present invention to provide a process of producing 2,6-diamino-9-[saccharide]purine.
It is also an object of the present invention to provide a process of producing a guanine nucleoside substituted in the 6th position.
Another object of the present invention is a process of producing 6-(nitrophenoxy)-9-[saccharide]purine having a nitro group in the 3, 4 or 5 position.
It is another object of the present invention to provide a process of producing 6-(substituted halophenoxy-9-[saccharide]purine.
In accordance with these objects, as well as others which will be readily apparent to the skilled artisan, the present invention provides a composition of matter having the structure of the formula (I): ##STR1## wherein R 1 is a substituted or unsubstituted nitrophenoxy group having a nitro group in the 3, 4 or 5 position, or a pentafluorophenoxy group. R 2 is an electron withdrawing group, H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons or a substituted or unsubstituted aromatic compound having from about 1 to about 20 carbons; R 3 may be the same as or different from R 2 and may be an electron withdrawing group, H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons, or a substituted or unsubstituted aromatic compound having from about 1 to 20 carbons; and R 4 is a substituted or unsubstituted saccharide.
In accordance with another aspect of the present invention, there is provided a composition of matter having a structure of the formula (I): ##STR2## wherein R 1 is a nucleophile capable of binding at the 6th position of a purine ring system without cleaving R 2 ; R 2 is an electron withdrawing group whose corresponding carboxylic acid has a pK a less than that of acetic acid, R 3 may be the same as or different from R 2 and may be an electron withdrawing group, H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons, or a substituted or unsubstituted aromatic compound having from about 1 to 20 carbons; and R 4 is a substituted or unsubstituted saccharide.
Further in accordance with another aspect of the present invention, there is provided a composition of matter as described immediately above, wherein R 1 is a substituted or unsubstituted nitrophenoxy group having a nitro group in the 3, 4 or 5 position, a non-sterically hindered compound having a structure of the formula (II): ##STR3## wherein R 5 comprises a halogen or hydrogen and wherein at least three R 5 groups are halogens, an aromatic tertiary amine, or an aliphatic tertiary amine.
Also in accordance with the present invention, there is provided a composition of matter having a structure of formula (I): ##STR4## wherein R 2 and R 3 may be the same or different and comprise H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons, or a substituted or unsubstituted aromatic compound having from about 1 to 20 carbons; R 4 is a substituted or unsubstituted saccharide; and wherein R 1 is selected from the group consisting of (CH 3 ) 2 NC 5 NH 4 --, a substituted or unsubstituted nitrophenoxy group having a nitro group in the 3, 4 or 5 position, or a pentafluorophenoxy group.
In a particularly preferred aspect of the present invention, compositions are provided wherein R 1 is a 4-nitrophenoxy group and R 2 is a trifluoroacetyl group. In another preferred aspect thereof, R 1 is a pentafluorophenoxy group and R 2 is a trifluoroacetyl group.
In accordance with another aspect of the present invention there is provided a composition of matter 2-N-trifluoracetamido-6-(4-nitrophenoxy)-9-(2-deoxy-beta-D-erythro-pentofuransoyl)pyrine and a composition or matter 2-N-(trifluoroacetamido-6-pentafluorophenoxy)-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine.
In accordance with another aspect of the present invention there is provided a composition of matter 2-N-trifluoracetamido-6-(4-nitrophenoxy)-9-(ribo)purine and a composition of matter 2-N-trifluoroacetamido-6-(pentafluorophenoxy)-9-(ribo)purine.
These compositions have uses and advantages far in excess of expectations. Specifically, these compounds may be produced quickly, (i.e. the pyridyl compound may be formed in less than about two hours and the pentafluorophenoxy derivatives were formed in between about 24-48 hours) in high yield (i.e. in excess of 67%) from conventional and commercially available starting materials with little or no effort. Many of the compounds produced according to the present invention are shelf/storage stable and may be prepared in advance for subsequent use.
These uses may include, without limitation, the formation of other 6 substituted guanine nucleosides such as, for example, 2,6-diamino-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine which is useful in stability studies of DNA, as well as the ribose derivative which is similarly useful for RNA. Other uses include those previously discussed. Furthermore, from these compounds various fluorescently labeled compositions and compositions having potential anti-tumor activity may be produced.
Furthermore, some of these compositions may be quickly, conveniently and easily inserted into or attached to an oligonucleotide and, thereafter, converted to another form, (deprotected), in situ.
Other compounds, in accordance with the present invention, are particularly useful as intermediates for the formation of such compounds as those previously described.
It has been discovered that while some guanine nucleosides having a pyridine or selected other tertiary amine in the 6th position in accordance with the present invention are not stable for long periods of time, they may be nucleophilically substituted by other compounds which are storage stable, in dramatically increased yields. For example, when concentrated aqueous ammonia (which is nucleophilic in and of itself) is added directly to the 6-pyridine substituted guanine nucleoside compositions in accordance with the present invention, a substituted guanine nucleoside having an NH 2 group in the 6th position thereof is obtained in yields of about 34%. This is a substantially greater yield than can be obtained through known processes. However, this yield is substantially lower than those obtained through the use of other processes, in accordance with the present invention.
In accordance with another aspect of the present invention there is provided a composition of matter comprising a saccharide and a nitrogenous heterocyclic purine having a compound derived from a mono-, di-, and tri-halogen substituted acetic anhydride bonded thereto in the N 2 position. In a particularly preferred embodiment the anhydride is a trifluoroacetic anhydride.
It has been advantageously discovered that guanine nucleosides having specific N 2 protecting groups are useful in the formation of 6-substituted guanine nucleosides, even when compared to N 2 protecting groups of very similar structure. For example, it was unexpectedly discovered that a 6-substituted pyridyl guanine derivative would be formed having at least one N 2 group of CF 3 CO under the mild conditions of the processes of the present invention.
As previously discussed, these pyridyl-containing guanine nucleosides may be readily converted to other useful intermediates, such as, for example, 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine in yields approximating 95% after 24 hours. These intermediates can then be inserted into an oligonucleotide and used as is, or converted while within a nucleotide to other useful forms, or may be converted to other useful 6-substituted nucleosides such as 2,6-diamino-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine in high yields.
The pyridyl may also be readily converted to the 2,6-diamino-deoxyguanosine directly; however, yields are lower, on the order of 34% in only 1.5 hours.
While not wishing to be bound by any particular theory of operation, the present invention includes the realization of the roles played by substituents in the N 2 and 6th positions of a guanine nucleoside in the formation of six substituted derivatives thereof. As the aforementioned Bridson et al. paper clearly indicates, the art has been unable to find the right combination of factors which will allow for the formation of guanine nucleosides and nucleotides substituted in the 6th position with any degree of specificity, versatility, or usefulness. For example, the aforementioned article discloses the ability to convert, by acylation, quanosine to a 6th acyl substituted form. However, it is unable to accomplish anything useful with this compound. The present invention includes the realization that certain highly electron withdrawing acyl groups when reacted to form acyl derivatives in the 6th position can be readily substituted by a pyridyl or pyridinium ion and thereafter further substituted to form useful compounds. Thus, the invention includes a realization of the roles, respectively, of acylation and substitution with a pyridinium ion in the formation of useful 6-substituted guanine nucleosides and nucleotides.
It has also been hypothesized that the presence of a sufficiently electron withdrawing species in the N 2 position is necessary for the formation of, for example, the pyridyl or other tertiary amine containing compound. For example, preliminary indications are that use of the processes of the present invention on inosine (a nucleoside having an H bonded to the second position) will not result in the formation of a pyridyl derivative even when such strongly electron withdrawing species as trifluoroacetic anhydride derivatives are used to acylate the 6th position. It appears, therefore, that there are some localized effects which encompasses both the 6th and the N 2 position and which allow for the formation of intermediates in accordance with the present invention. Presumably, of course, any acylating agent which is a derivative of a carboxcylic acid or in fact, any electron withdrawing group might be sufficient in the N 2 position to allow for the formation of a pyridyl group in the 6th position depending upon the electronegativity of the acylating group used in the 6th position. It has been found, however, that the use of more strongly electronegative substituents in the N 2 position will allow for greater flexibility in the groups used to both acylate and substitute in the 6th position. It is preferred therefore, that the N 2 group or its corresponding carboxylic acid analog will have an electronegativity greater than that of acetic acid. This means the corresponding acid is more acidic than acetic acid.
Consider, for example, that reactions using a deoxyguanosine having an acetyl group(s) in the N 2 position fail to produce readily detectable amounts of the pyridyl derivative even though the reaction mixture was driven for 20 hours at 50° C. Trifluoroacetic anhydride derivatives used to acylate the 6th and the N 2 positions, however, produce radically different results, including the formation of a high concentration of the pyridyl derivative.
While these compounds are structurally similar in some respects, (acetic acid and trifluoroacetic acid) they are very different in terms of their electron withdrawing nature and electronegativity. For example, the relative acidity of acetic acid and trifluouroacetic acid are indicators of such electronegativity. Trifluoroacetic acid is considerably more acidic (lower pH, higher in acidity) and has a disassociation constant (K a ) of 0.59 while acetic acid has K a of 1.8×10 -5 . In terms of pK a , these values are 0.23 and 4.72, respectively. This indicates that the former (trifluoroacetic acid) is about 33,000 times as acidic as the latter (acetic acid).
Presumably, therefore, an acyl group containing an acylating agent whose corresponding carboxylic acid analog has a pK a which is lower than that of acetic acid may be useful in accordance with the present invention. Certainly compounds with electronegativities comparable to or greater than that of trifluoroacetic anhydride derivatives will be readily useful. Accordingly, compounds having substituents in the N 2 position whose carboxylic acid counterparts have an pK a less than that of acetic acid are preferred, as is the use of such compounds as acylation agents for the 6th position.
In addition to being relatively efficient to make, the nucleosides produced in accordance with the present invention are useful in that they may be used to generate a wide variety of other useful compounds. For example, these compounds are useful in the production of oligonucleotides in a quick and convenient manner because these N 2 protecting groups will be completely cleaved with a high degree of specificity and control.
Furthermore, the compounds of the present invention may be inserted into oligonucleotides in various forms, and thereafter converted into other useful forms. For example, a nucleoside having a pentafluorophenoxy group in the 6th position could first have the saccharide protecting group removed from the 3' and 5' positions of the 2'-deoxyribose by hydrolysis without removing the N 2 protecting group. The resulting 6th and N 2 position substituted guanine nucleoside can be re-protected in the 3' and 5' positions with protecting groups useful for nucleotide insertion and subsequently inserted into a nucleotide. Thereafter, the phenoxy group in the 6th position could be replaced, for example, with dimethylamino pyridine. This may be accomplished in an environment substantially free from compounds which promote hydrolysis such that the N 2 protecting group remains. In the presence of compounds which do promote hydrolysis, the deprotected, 6 substituted derivative is formed. Both of these compounds are fluorescent.
Specifically, there is provided, a process for the modification of an oligonucleotide containing a 6-substituted guanine nucleoside comprising the steps of:
providing an oligonucleotide having a structure of the formula (VI): ##STR5## wherein n is 0 or a positive integer, G, G' and G" may be the same or different and comprise hydrogen, hydroxyl, or a protected hydroxyl group, Base1, Base2, and Base3 may be the same or different and comprise a substituted or unsubstituted purine or pyrimidine base, or mixtures thereof, and wherein at least one of said Bases has a structure of the formula (VII): ##STR6## wherein R 1 is a nucleophile capable of binding at the 6th position of a purine ring system without cleaving R 2 ; R 2 is an electron withdrawing group whose corresponding carboxylic acid has a pK a less than that of acetic acid; R 3 may be the same as or different from R 2 and may be an electron withdrawing group or hydrogen, and wherein A comprises a first protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, B comprises a second protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, and A and B may be the same or different; and substituting R 1 with a nucleophile.
In accordance with another aspect of the present invention there is provided a 6-dialkylaminopyridinium-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine. In a preferred embodiment the composition is 6-dimethylaminopyridinium-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine. The corresponding ribose nucleosides are also provided hereby. These compositions have been found to be particularly useful since they are highly compatible with oligonucleotides and may be readily inserted therein and because they are, in general, fluorescent and therefore useful as labeling compounds. These may be used for replacing radioactive species such as P 32 which is used in auto radiography (DNA fingerprinting). P 32 has the disadvantage of a short half-life and radioactivity. The use of fluorescent nucleosides in accordance with the present invention overcomes both problems. Thus the fluorescent species in accordance with the present invention may be used in place of radioactive compounds in other classic diagnostic techniques such as radioimmunoassay and the like.
In accordance with another aspect of the present invention there is provided an oligonucleotide having a structure of the formula (VI): ##STR7## wherein n is 0 or a positive integer, G, G' and G" may be the same or different and comprise H, OH, or a protected hydroxyl group, Base1, Base2, and Base3 may be the same or different and may be a substituted or unsubstituted purine or pyrimidine base, or mixtures thereof, and wherein at least one Base has a structure of the formula (VII): ##STR8## wherein R 1 is a nucleophile capable of binding at the 6th position of a purine ring system without cleaving R 2 ; R 2 is H or an electron withdrawing group; R 3 may be the same as or different from R 2 and may be an electron withdrawing group or H; and wherein A comprises a first protecting group, OH, H, or a mono-, di-, or tri-phosphate, B comprises a second protecting group, OH, H, or a mono-, di-, or tri-phosphate, and A and B may be the same or different.
In a preferred embodiment, R 2 comprises an acyl portion of a reactive acid derivative whose corresponding carboxylic acid has a pK a less than that of acetic acid.
These compositions are oligonucleotides which may be useful as DNA probes, as fluorescent labeling compounds, and the like.
In accordance with yet another aspect of the present invention, there are provided processes for the production of 2,6-diamino-9-[saccharide]purine. This includes the production of both substituted guanosine and deoxyguanosine derivatives. One such process comprises the steps of:
acylating at least the 6th position of a guanine nucleoside with an acylating agent;
substituting a pyridinium ion for said acyl group in the 6th position of said nucleoside; and
reacting said nucleoside with concentrated aqueous ammonia and forming said 2,6-diamino-9-[saccharide]purine.
In a closely related aspect according to the present invention, there is provided a process of producing 2,6-diamino-9-[saccharide]purine comprising the steps of:
acylating at least the 6th position of a guanine nucleoside with an acylating agent;
substituting a tertiary nitrogen of a tertiary nitrogen-containing compound for said acyl group in the 6th position of said nucleoside;
wherein said step of acylating and said step of substituting are conducted in an environment which is substantially free from compounds which promote hydrolysis; and
reacting said nucleoside with concentrated aqueous ammonia and forming said 2,6-diamino-9-[saccharide]purine. This includes both ribose and 2'-deoxyribose containing compounds.
In accordance with a further aspect of the present invention a process is provided for making 2,6-diamino-9-[saccharide]purine comprising the steps of:
reacting a guanine nucleoside with a tertiary amine compound which is a pyridine and an acylating agent to form a first reaction product; and
reacting said first reaction product with concentrated aqueous ammonia to form a 2,6-diamino-9-[saccharide]purine.
In accordance with another aspect of the present invention, there is provided a process of producing 2,6-diamino-9-[saccharide]purine comprising the steps of:
reacting a guanine nucleoside with a tertiary amine compound and an acylating agent to form a first reaction product, wherein said reaction is conducted in an environment which is substantially free from compounds which promote hydrolysis; and
reacting said first reaction product with aqueous ammonia to form a 2,6-diamino-9-[saccharide]purine.
As with all of the other compounds provided hereby, the ribose and 2'-deoxyribose containing nucleosides are particularly preferred.
The processes of the present invention utilize commercially available starting materials and are highly versatile in that either protected or unprotected guanine nucleosides may be used. Experimental yields of these processes have been approximately 34%, which represents a substantial improvement over the prior procedures, such as that disclosed in the Tetrahydron article, supra.
Perhaps the most significant and unexpected feature of the processes according to this aspect of the present invention is the dramatic decrease in the length of time required to produce 2,6-diamino-guanine-nucleosides in accordance with the present invention when compared to the times required for conventional processes. In fact, the time required to obtain significantly higher yields of the 2,6-diamino-guanine-nucleosides according to the present invention may be measured in hours, instead of days. See the Tetrahedron article, supra. Thus the processes in accordance with the present invention provide highly versatile protocols for the formation of 2,6-diamino-guanine-nucleosides in a more efficient, more cost effective manner.
In accordance with another aspect of the present invention there is provided a process of producing a guanine nucleoside substituted in the 6th position comprising the steps of:
providing a guanine nucleoside;
acylating at least the 6th position of said guanine nucleoside with an acylating agent;
substituting a tertiary amine group for said acyl group in the 6th position of said guanine nucleoside, wherein said steps of acylating and substituting are conducted in an environment which is substantially free from compounds which promote hydrolysis; and
substituting said tertiary amine group with a first nucleophile to form a guanine nucleoside substituted in the 6th position.
In accordance with another aspect of the present invention there is provided a process of producing a guanine nucleoside substituted in the 6th position comprising the steps of:
reacting a guanine nucleoside with a tertiary amine compound and an acylating agent to form a first reaction product wherein said reaction is conducted in an environment which is substantially free from compounds which promote hydrolysis; and
reacting said first reaction product with a first nucleophile capable of binding at a 6th position of said guanine nucleoside and forming a guanine nucleoside substituted in the 6th position.
These processes allow for the convenient production of guanine nucleosides substituted in the 6th position from commercially available starting materials. They allow for the use of both protected and unprotected guanine nucleosides, and may be used to form a wide variety of useful intermediate and end products.
For example, the processes hereof may be used for the direct formation of 2,6-diamino-substituted-guanine-nucleosides or compositions having dialkylaminopyridinium or methoxy groups in the 6th position thereof. As previously noted, the diamino compounds are useful as intermediates in the formation of other substituted products as well as being directly useful for studying the structure of DNA and the formation of bonds between polynucleotides.
The 6-methoxyguanine derivatives have been useful in quantifying thermodynamic comparisons of base pairs formed by the carciogenic lesson as was discussed in Gaffney and Jones cited supra.
Furthermore, these highly versatile processes may be used for the formation of six substituted guanine nucleosides having, for example, a 4-nitrophenoxy or, pentafluorophenoxy group bonded thereto. As discussed previously these compositions are useful as intermediates for direct insertion into oligonucleotides.
Processes are also provided for the production of 6-(nitrophenoxy)-9-[saccharide]-purine wherein the nitrophenoxy has a nitro group in the 3, 4 or 5 position comprising the step of reacting a guanine nucleoside having a pyridinium ion in the 6th position thereof with a substituted or unsubstituted nitrophenol having a nitro group in the 3, 4 or 5 position and forming a 6-(nitrophenoxy)-9-[saccharide]purine and 6-(substituted halo-phenoxy-9[saccharide]purine comprising the step of: reacting a guanine nucleoside having a pyridinium ion in a 6th position thereof with a compound having a structure of the formula (II): ##STR9## wherein R 5 comprises a halogen or hydrogen and wherein at least three R 5 groups are halogens, and forming a 6-(substituted halo-phenoxy-9-(saccharide)purine.
Also provided hereby is a composition of matter having a structure of the formula (I): ##STR10## wherein R 1 is a substituted phenoxy group having at least one election withdrawing group attached thereto, with the proviso that if said electron withdrawing group is a halogen, at least three halogens are attached to said phenoxy group, and with the further proviso that the phenoxy group does not contain a substituent at the 2 or 6 position of a size that will create steric hindrance. R 2 is an electron withdrawing group, H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons or a substituted or unsubstituted aromatic compound having from about 1 to about 20 carbons; R 3 may be the same as or different from R 2 and may be an electron withdrawing group, H, a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons, or a substituted or unsubstituted aromatic compound having from about 1 to 20 carbons; and R 4 is a substituted or unsubstituted saccharide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Generally, a nucleoside comprises a nitrogenous heterocyclic base which is derived from either a pyrimidine or purine, and a pentose or five-membered sugar. A nucleotide has an additional molecule of phosphoric acid attached to the saccharide. In accordance with the present invention, however, a nucleoside may broadly include a nitrogenous heterocyclic base as previously described attached to a saccharide which may or may not be a pentose. Saccharides include both aldoses (sugars derived from monosaccharides having an empirical formula (CH 2 O) n where n equals 3 or some larger number and the monosaccharide has an aldehyde or like group at the end of its chain) or a ketose (derivatives of monosaccharides having a ketone group within its structure other than at its end). Saccharides also include both the ring and open chain forms and the levorotatory (L) and the dextrorotatory (D) forms and the alpha and the beta forms thereof.
Pentoses include ribose, arabinose, xylose, lyxose, ribulose, and xylulose. Other useful saccharides include hexoses such as allose, altrose, glucose, mannose, gluose, idose, galactose, talose, psicose, fructose, sorbose, and tagatose. Tetroses include erythrose, threose, and erythrulose. Thus, when in this document reference is made to a chemical whose name includes "[saccharide]", or elsewhere where the word saccharide is used it should be understood that the alpha or beta, D or L; and oxy or deoxy forms of saccharides are contemplated. Furthermore, in preferred embodiments according to the present invention, the term "[saccharide]" in a name, or the term saccharide in text both refers to ribose or 2'-deoxyribose.
Purines and pyrimidines are two classes of nitrogenous bases which are generally found in nucleosides and are heterocyclic compounds. The most well known of these compounds are the purines adenine (6-amino purine), guanine (2-amino-6-oxopurine) and the pyrimidines cytosine (4-amino-2-oxopyrimidine), thymine (5-methyl-2,4-dioxopyrimidine) and uracil (2,4-dioxopyrimidine) which are the so called "Watson-Crick" compounds of DNA and RNA. They are also referred to, generically, as bases. Other bases include N 6 -methyladenine, 2-methylguanine, 5-methylcytosine, 5-hydroxymethylcytosine, psuedo-uridine, inosine, ribothymidine, 5,6-dihydrouridine, 1-methylinosine, 1-methylguanosine, N 2 -dimethylguanosine, 5,6-dihydrouracil, 1-methyluracil, 3-methyluracil, 5-hydroxymethyluracil, 2thiouracil, N 4 -acetylcytosine, 3-methylcytosine, 5-methylcytosine, 5-hydroxymethylcytosine, 1-methyladenine, 2-methyladenine, 7-methyladenine, N 6 -methyladenine, N 6 ,N 6 -dimethyladenine, N 6 -(delta 2 -isopentenyl)adenine, 1-methylguanine, 7-methylguanine, N 2 -methylguanine and N 2 ,N 2 -dimethylguanine.
In general, the present invention is directed to compounds which are based in part on guanine having a structure of the formula (A) ##STR11## having an oxo, ketone group in the 6th position and an amine group attached in the 2nd position. Traditionally, guanine is attached to a saccharide at the 9th position to form a nucleoside.
While one aspect of the present invention is primarily directed to compounds in which guanine is attached in the 9th position to a saccharide, it should be understood that guanine may be attached to other compositions without departing from the scope of the present invention. This is particularly true if the group attached to the ninth position is something other than a proton or a group having strong localized electrophilic or nucleophilic properties.
For example, instead of a saccharide, it is envisioned that long or short chain aliphatic and substituted aliphatic groups, as well as aromatic compounds such as benzene, would behave much the same in nucleosides as nucleosides containing saccharides in the 9th position when used in the processes of the present invention. It is possible that where the 9th position contains a proton, reactions may be somewhat different. However, it is anticipated that the processes need only be modified to the extent that additional stoichiometric amounts of acylating agents or other material will be required. Alternatively, it is anticipated that the reaction might preferentially include the use of a protecting group to prevent further reactions in that position.
In accordance with preferred embodiments of the present invention, there is provided a nucleoside which has a structure of the formula (I): ##STR12## wherein R 1 is an oxo, ketone, or a nucleophile.
A nucleophile in accordance with the present invention is a group which contains an electron rich atom or atoms capable of donating electrons. During different portions of the process of the present invention, the term nucleophile may include those compounds which are capable of bonding at the 6th position of a purine ring system without cleaving R 2 or which do not themselves promote hydrolysis. These may include nitrophenoxy groups having a nitro group in the 3, 4 or 5 position or other substituted phenoxy groups. Also included are halogen substituted phenoxy compounds so long as the aggregate of the halogen substitutions is sufficient electronegative or electron withdrawing. When the halogen used is fluorine, two or more fluorine substituents have been found to be required. It is preferred, of course, that the aggregate of the substitutions be as electronegative as possible and to that end, a pentafluoro substituted phenoxy group is amongst the most preferred nucleophiles useful in accordance with the present invention.
When the halogen used is chlorine or another of the less electronegative halogens, three or more will be required.
Phenoxy groups which are substituted in the 3, 4 and/or 5 position are most preferred in accordance with the present invention. This is because substitutions in the 2 and/or 6 position may be of a size sufficient to create steric hindrance which interfere with their ability to react in the processes of the present invention. Therefore, such compounds as ortho- or 2-nitrophenoxy or compound substituted in the 2 and/or 6 position with electron withdrawing species having a greater atomic radii than, for example, chlorine are not preferred, as they will reduce the process efficiency.
Tertiary amines have also been found to be effective as nucleophiles in accordance with the instant invention in that they are capable of bonding to the 6th position without cleaving the R 2 group. While primary and secondary amines are chemical analogs to compounds such as alcohols inasmuch as they have both electron donating properties and electron accepting properties, tertiary amines are the chemical analogs of ethers in that both ethers and tertiary amines have only basic, electron donating properties. A tertiary amine is a nitrogen bonded in three positions to carbon or other non-proton based substituents. Tertiary amines include both aromatic compounds such as pyridine or substituted pyridines such as dialkylamino pyridine or dimethylamino pyridine (DMAP), and aliphatic amines including trialkylamines, such as trimethylamine or triethylamine.
Other nucleophiles useful in accordance with the present invention and particularly useful during other portions of the present invention are those which cause hydrolysis of the R 2 group in the N 2 position, (the N 2 protecting group). These include primary amines and ammonia as well as primary alcohols, certain secondary and tertiary alcohols, certain secondary amines, thiols, H 2 S and the like. When added, these compositions tend to promoted hydrolysis, particularly of the N 2 protecting groups such as R 2 .
Certain nucleophiles do not, in and of themselves, cause hydrolysis of R 2 . However, when combined with other compounds such as water, alcohol, or ammonia they may cause hydrolysis. These may, of course, be useful in accordance with the present invention. Consider, for example, that DMAP may be added during the step of substituting a tertiary amine with a first nucleophile. If this substitution is conducted in the presence of compounds which promote hydrolysis, then a 6th substituted substituent would be realized in which protecting groups on a saccharide attached as R 4 as well as the groups in positions R 2 and R 3 would be hydrolyzed to form hydrogen or hydroxide groups. The same group (DMAP), however, may be added in an environment which is substantially free from other compounds which promote hydrolysis. In this eventuality, a DMAP 6 substituted guanosine may be realized wherein at least the N 2 protecting group in the R 2 position remains.
Secondary amines represent an interesting class of compounds with regard to the present invention in that certain secondary amines will behave more as an electrophile than a nucleophile. To that extent, these compounds will not be useful in accordance with the processes of the present invention. However, those which are more nucleophilic in character as defined above may find application in the processes of the present invention.
Other nucleophiles useful in accordance with the present invention include methylamine, ethylamine, propylamine, butylamine, pentylamine, other primary alkylamines; dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, other secondary alkylamines; trimethylamine, triethylamine, other tertiary alkylamines; benzylamine, substituted benylamines; pyridine, substituted pyridines, methanol, ethanol, propanol, other primary and secondary alcohols, H 2 S, methanethiol, other primary and secondary thiols; thiophenol and substituted thiophenols; other aromatic or heterocyclic thiols.
R 2 may be hydrogen in the unreacted nucleosides and may be hydrogen again at the conclusion of the processes in accordance with the present invention and/or when placed into a nucleotide or oligonucleotide. R 2 may be a substituted or unsubstituted aliphatic compound having from about 1 to about 20 carbons or a substituted or unsubstituted aromatic compound having from about 1 to 20 carbon atoms. R 2 may also be an N 2 protecting group. For the purposes of the present invention, the term "protecting group" indicates a compound which will inhibit the reaction of a group in the position being protected, but which may be readily removed when desired. The term "N 2 protecting group" indicates a group which protects at least one of the positions on the nitrogen attached in the 2nd position to the purine ring. R 2 is preferentially, however, an electron withdrawing group and in particular, an electron withdrawing group whose corresponding carboxylic acid has a pK a less than that of acetic acid. That is to say, compounds whose carboxylic acid analog are stronger acids than acetic acid. More particularly, the R 2 group comprises at least the acyl portion of a reactive carboxylic acid derivative and particularly those whose corresponding carboxylic acid have a pK a as discussed above.
pK a is the negative log of K a , which is a dissociation constant. K a may be expressed, based on the equation HA (proton containing acid)+H 2 O=H 3 O + +A (conjugate base), as: ##EQU1## where [H 3 O+], [A] and [HA] represent the concentrations of conjugate acid, conjugate base and acid respectively and where fH, fA and fHA are activity coefficients. See Ramette, Chemical Equilibrium And Analysis, Addison-Wesley, 1981, 258-260. pH is the negative log of [H 3 O+].fH.
Carboxylic acids from which anhydrides, esters and acid halides in accordance with the present invention are derived, may include, without limitation, fluoroacetic acid, chloroacetic acid, bromoacetic acid, dichloroacetic acid, trichloroacetic acid, dibromoacetic acid, trichloracetic acid, methoxyacetic acid, cyanoacetic acid, nitroacetic acid, iodoacetic acid, HCOOH, ClCH 2 CH 2 COOH, C 6 H 5 COOH, H 2 C═CHCOOH and C 6 H 5 CH 2 COOH.
R 3 may be the same as or different from R 2 and may include hydrogen, or an electron withdrawing group. In a preferred embodiment according to the processes of the present invention, both the R 2 and R 3 positions contain electron withdrawing groups prior to hydrolysis. However, it is believed that the propensity for compounds in accordance with the present invention to form reaction intermediates in which both N 2 positions, namely R 2 and R 3 , are substituted with electron withdrawing species, is somewhat depended upon the stoichiometric amounts of electron withdrawing group added to the reaction mixture, and the amount of steric interference that one group will generate with regard to another.
R 4 may be hydrogen, a substituted or unsubstituted aromatic or aliphatic group, or may be a substituted or unsubstituted saccharide as previously described. In preferred embodiments in accordance with the present invention, R 4 is a saccharide, and is more preferably a pentose. The most preferred pentoses are the pentoses ribose and 2'-deoxyribose in which the hydroxide group and the 2'-position is replaced by hydrogen. The beta-D forms are also particularly preferred.
In accordance with the present invention, saccharides may be protected at various times by one or more protecting groups. Protecting groups are as defined previously with regard to the R 2 group, and are groups which, in the present context, will inhibit the reaction of the saccharide in the position being protected and which may be removed in a controlled fashion by hydrolysis. The list of potential protecting groups is virtually endless so long as the basic functions discussed above are fulfilled. However, in accordance with preferred aspects of the present invention, the following may be considered for use as protecting groups:
R 6 X 2 CCOO--, wherein X comprises hydrogen or a halogen and mixtures thereof, and R 6 is an aliphatic group of between about 1 and about 20 carbons or R 6 X 2 CCO-- wherein R 6 is as above, or halogen substituted or unsubstituted trityl, (CH 3 ) 3 C(CH 3 ) 2 SiO--, toluyl, substituted or unsubstituted benzyl, isobutyryl, tert-butyldiarylsilyl, tert-butyldialkylsilyl, COCH 2 CH 2 COMe, bis(diisopropylamino)methoxyphosphine, or compounds having a structure of the formula (III-V). ##STR13## wherein R 7 is a phosphate protecting group.
It should also be noted that certain protecting groups may be used during specific reactions such as those placed in the 3' and 5' position of a ribose and/or 2'-deoxyribose to assist in the facilitation of the attachment of a nucleoside to an oligonucleotide in accordance with the present invention.
In one aspect and one preferred embodiment of processes in accordance with the present invention, saccharide protecting groups may be added to the saccharide prior to the reaction of a nucleoside containing the protected saccharide in accordance with the procedures discussed herein. Thus, a guanine nucleoside may be pre-protected. In that eventuality, the saccharide protecting groups and the N 2 protecting groups may be the same or different. In another preferred aspect of the present invention, however, the guanine nucleoside may contain no protecting groups prior to their initial reaction using the processes of the present invention. In that eventuality, and provided sufficient stoichiometric amounts of reactants are used, these saccharides will be protected during acylation by groups which will be the same as the N 2 protecting groups. Saccharides would otherwise have an H, OH, or mono-, di-, or triphosphate attached thereto.
Another form of protecting group is the phosphate protecting group which may be found in certain saccharide protecting groups. A phosphate protecting group, like the N 2 and saccharide protecting groups, will inhibit a reaction in the position protected. In this case, it will provide protection for the phosphorus found in certain other saccharide protecting groups which are themselves useful for inserting nucleosides into nucleotides. Without limitation, phosphate protecting groups may include methyl and 2-cyanoethyl groups. The trichloroethyl group is also used.
The term acylating agent or acylating compound includes electron withdrawing groups which comprise an acyl portion of a reactive acid derivative. Reactive acid derivatives include substituted aliphatic acids and hydrides, substituted aliphatic acid halides and substituted phenol esters. The most preferred constituents are electron withdrawing groups whose carboxylic acid counterparts have a pK a less than that of acetic acid. Therefore, the most preferred reactive acid derivatives are those comprising mono-, di-, and tri-halogen substituted acetic anhydrides. The most preferred acylating agent according to the present invention is trifluoroacetic anhydride which yields a trifluoroacetyl in the N 2 and 6th positions.
By the term capable of promoting hydrolysis, it is understood that hydrolysis of the N 2 groups is contemplated. The fact that hydrolysis of the protecting groups of the saccharide such as those in the 2', 3', or 5' positions of a ribose, and the 3' and 5' positions of a 2'-deoxyribose are hydrolyzed is not of importance. Thus, a reaction conducted in an environment which is substantially free from compounds which promote hydrolysis means an environment free from compounds which will promote hydrolysis in the N 2 position. If a pentafluorophenoxy group is used to substitute a pyridinium ion attached in the R 1 position in accordance with the processes of the present invention, the fact that, over time, hydrolysis of the saccharide protecting groups occurs, is inconsequential. The pentafluorophenoxy group is not considered as promoting hydrolysis.
An oligonucleotide is a polymeric-like compound wherein a plurality of saccharides are connected by phosphate groups and wherein each individual saccharide has a base or nucleic acid attached thereto. RNA and DNA are forms of oligonucleotides. For the purposes of the present invention, an oligonucleotide may be represented by the formula (VI): ##STR14## wherein n is 0 or a positive integer, G, G' and G" may be the same or different and comprise hydrogen, hydroxyl, or a protected hydroxyl group, Basel, Base2, and Base3 may be the same or different and comprise a substituted or unsubstituted purine or pyrimidine base, or mixtures thereof, and wherein at least one of said Bases has a structure of the formula (VII): ##STR15## wherein R 1 is a nucleophile capable of binding at the 6th position of a purine ring system without cleaving R 2 ; R 2 is H or an electron withdrawing group; R 3 may be the same as or different from R 2 and may be an electron withdrawing group or hydrogen, and wherein A comprises a first protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, B comprises a second protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, and A and B may be the same or different.
It should be emphasized that neither the length of the oligonucleotide nor the order of bases contained therein is of particular importance in accordance with the present invention so long as at least one of the bases is a nucleic acid derivative in accordance with the present invention. It is preferred, however, that oligonucleotides in accordance with the present invention have a length of between about 2 and about 50 repeating units based on the number of nucleic acids contained therein. In a most preferred embodiment according to the present invention, the oligonucleotide is of a size adapted and effective for use as a probe. This generally includes between about 10 and about 20 bases. Oligonucleotides in accordance with the present invention may be produced including nucleosides in accordance with the present invention by any known method. These include, without limitation, the H-phosphonate method and the beta cyanoethyl phosphoromidite method.
The H-phosphonate method is described in Gaffney and Jones, "Large-Scale Oligonucleotide Synthesis By the H-Phosphonate Method" Tetrahedron Letters, Vol. 29, No. 22, pp 2619-2122, 1988. Briefly, the pentafluorophenyl derivative of a guanine nucleoside in accordance with the present invention was converted to a 5'-DMT-3'-phosphonate derivative by standard procedures. To summarize one such procedure: the 6-pentafluorophenoxy guanosine of the present invention was first reacted with a slight excess of 4,4'-dimethoxytrityl chloride (DMT-Cl) in pyridine solution (about 5-10 mL per mmol of said pentafluorophenoxy derivative) using a catalytic amount (0.05 eq) of 4-dimethylaminopyridine (DMAP). These are standard conditions, which have been widely published. See for example "Oligonucleotide Synthesis: A Practical Approach" Ed. M. J. Gait, IRL Press, Washington DC, 1984, pp. 23-34. The resulting product was then converted to the H-phosphonate form using the method of Froehler et al. (Froehler, B. C.; Ng, P.G.; Mateucci, M. D. Nucleic Acids Res. 1986, 14, 5399-5401) as modified by (Gaffney, B. L.; Jones R. A. Tetrahedron Lett. 1988, 22, 2619-2622). In this procedure, a solution of the above compound is dissolved in methylene chloride (about 10-20 mL per mmol thereof) and was added dropwise to a cooled (ice bath) methylene chloride solution of PCL 3 , N-methyl morpholine and 1,2,4-triazole in the ratios of 10 mL of CH 2 Cl 2 per mmol of PCL 3 , 5 mmol of PCl 3 , per mmol of the resulting product above, 46 mmol of N-methyl morpholine per mmol of the resulting product above, and 3.3 mmol of triazole per mmol of PCl 3 ). The remainder of the synthesis and the oligonucleotide synthesis is reported in the above referenced Tetrahedron Letters article. The particular oligonucleotide produced was d[TT(PFPG)TT], where d(PFPG) is pentafluorophenyl-2'-deoxyguanosine. This material was then converted to the 2-amino-2'-deoxyadenosine containing molecule d[TT(2-NH2-A)TT] by treatment with concentrated aqueous ammonia for approximately 24 hours.
B-CYANOETHYL PHOSPHORAMIDITE METHOD is reported in Gaffney and Jones, "Thermodynamics of the Base Pairs Formed by the Carcinogenic Lesion O 6 -Methylguanine with Reference both to Watson-Crick Pairs and to Mismatched Pairs" Biochemistry, 1989, 28, p 5881. Briefly, the 5'DMT derivative above was reacted with 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite. To summarize its preparation the 5'DMT derivative, dissolved in dry acetonitrile (5 mL per mmol), was treated with tetrazole (0.5 eq), diisopropylamine (0.7 eq), and after five minutes between 1.1 and 1.3 eq of the 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite was added. See A. D. Barone et al., "In situ Activation of Bis-Dialkylphosphines--A New Method for Synthesizing Deoxyoligonucleotides On Polymer Supports," Nucleic Acids Res., 1984, Vol 12, pgs 4051-4061. The product was purified by chromatography. The production of the oligonucleotide may be summarized as follows: 5'-DMT-thymidine bound to controlled pore glass (CPG) was treated sequentially with: 1) 2% dichloroacetic acid (to cleave the DMT group); 2) a solution of 0.16M tetrazole in acetonitrile (20-32 eq) and 0.04M of the 5'-protected cyanoethylphosphoramidite IV' (5-8 eq) in acetonitrile (coupling); 3) a solution of 0.016M I 2 in 89% tetrahydrofuran (THF), 10% water, and 1% pyridine, for 30 sec (oxidation); 4) a mixture containing 5% DMAP, 5% pyridine, 8% acetic anhydride and 82% THF for 11 sec (capping). This cycle was then repeated using 5'-DMT-thymidine-3'-cyanoethylphosphoramidite in place of the 5', 3' protected guanine nucleoside, to give as the final product d[T(PFPG)T] . This compound was converted to d[T(2-NH 2 -A)T] by heating in concentrated aqueous ammonia for 24 hours.
After the 6-substituted guanine nucleoside has been inserted into an oligonucleoside, it may be used directly. For example, a nucleoside having a DMAP in the 6th position may be used in as much as the nucleotide is fluorescently labeled. This may include its use in both the N 2 protected or unprotected form. However, the nucleoside may also be further substituted in the 6th position after the nucleoside has been incorporated in an oligonucleotide. For example, a 6-substituted pentafluorophenoxy guanine nucleotide which is part of an oligonucleotide may be converted to the DMAP species with or without deprotecting the N 2 position. Alternatively, the nucleotide may be converted to 2,6-diamino compound by reaction with concentrated ammonia.
Specifically there is provided a process for the modification of an oligonucleotide containing a 6-substituted guanine nucleoside comprising the steps of:
providing an oligonucleoside having a structure of the formula (VI): ##STR16## wherein n is 0 or a positive integer, G, G' and G" may be the same or different and comprise hydrogen, hydroxyl, or a protected hydroxyl group, Base1, Base2, and Base3 may be the same or different and comprise a substituted or unsubstituted purine or pyrimidine base, or mixtures thereof, and wherein at least one of said Bases has a structure of the formula (VII): ##STR17## wherein R 1 is a nucleophile capable of binding at the 6th position of a purine ring system without cleaving R 2 ; R 2 is an electron withdrawing group whose corresponding carboxylic acid has a pK a less than that of acetic acid; R 3 may be the same as or different from R 2 and may be an electron withdrawing group or hydrogen, and wherein A comprises a first protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, B comprises a second protecting group, hydroxyl, hydrogen, or a mono-, di-, or tri-phosphate, and A and B may be the same or different; and substituting R 1 with a nucleophile.
In one embodiment the step of substituting R 1 may be conducted in the presence of compounds which promote hydrolysis. This includes the use of nucleophiles which themselves cause hydrolysis of the N 2 protecting group, such as concentrated NH 3 , or those nucleophiles which do not, such as DMAP, but which are added in conjunction with other compounds which can cause hydrolysis. Nucleophiles in accordance with this aspect of the present invention include primary, secondary, or tertiary amines, primary alcohols, H 2 S, thiols, or concentrated ammonia.
In accordance with another embodiment of this process the step of substituting R 1 with said nucleophile is conducted in an environment which is substantially free from compounds which promote hydrolysis. In this case, nucleophiles useful for substitution into the R 1 position include tertiary amines or a substituted phenoxy having at least one electron withdrawing group attached thereto, with the proviso that if said electron withdrawing group is a halogen, a plurality of halogens are attached to said phenoxy and with the further proviso that said phenoxy does not contain a substituent at the 2 or 6 position of a size that will create steric hindrance. These may include a substituted or unsubstituted nitrophenoxy group in the 3, 4 or 5 position, a non-sterically hindered compound having a structure of the formula (II): ##STR18## wherein R 5 comprises a halogen or hydrogen and wherein at least three of said R 5 groups are halogens, or a substituted or unsubstituted tertiary amine.
In either event, it is preferable that the nucleophile be present in an amount effective to completely substitute R 1 . This may be generally accomplished by the use of a stoichiometric quantity of nucleophile or, more preferably, in excess thereof. Typically, the substitution is also conducted at a temperature above room temperature and at least above 20° C. It is more preferred that the reaction be run at a temperature of greater than 49° C. and most preferably at between about 50° and about 55° C.
In accordance with one aspect of the present invention, processes for producing 2,6-diamino-9-[saccharide]purine are provided. One such process includes the steps of acylating at least the 6th position of a guanine nucleoside with an acylating agent; substituting a pyridinium or pyridyl ion for said acyl group in the 6th position of said nucleoside; and reacting said nucleoside with concentrated aqueous ammonia to form said 2,6-diamino-9-[saccharide]purine.
In accordance with another aspect of the procedure described, a tertiary nitrogen of a tertiary nitrogen containing compound is used to substitute for said acyl group in the 6th position of a nucleoside and the steps of acylating and substituting the guanine nucleoside are conducted in an environment which is substantially free from compounds which promote hydrolysis. These steps are again followed by reacting the nucleoside with concentrated aqueous ammonia to form 2,6-diamino-9-[saccharide]purine. By saccharide, it is understood that preferred saccharides are the beta-D forms of ribose and 2'-deoxyribose.
Those of ordinary skill in the art have assumed that acylation of guanosine and substitution with a pyridinium ion are two incongruous steps. This is evidenced by the Bridson, et al. article discussed in the background section which illustrates that it is possible to acylate the R 1 position or the N 2 position of a guanine nucleoside, but not both, even when pyridine is present, albeit present as a solvent. Chollet, also referred to in the background section hereof, demonstrates that it is possible to form pyridyl containing nucleosides; however, acylation was not a route contemplated.
The present invention demonstrates, contrary to the teachings of the art, that guanosine may be acylated at least at the 6th position and preferably at at least both the 6th and the N 2 positions and thereafter, the acyl group in the 6th position may be selectively substituted with a pyridinium ion formed in situ therewith. The resulting pyridinium/guanine nucleoside complex may then be readily converted to other useful forms, quickly and in high yield or, in accordance with the instant aspect of the present invention, directly converted to the useful 2,6-diamino-9 form by reaction with concentrated aqueous ammonia.
By concentrated aqueous ammonia, it is understood that ammonia having a concentration of 10M or greater is contemplated. Preferentially, commercially available aqueous ammonia solutions having a concentration of 15M may be used. It should be understood, however, that greater concentrations than 15M are also useful. It should be further understood that one having ordinary skill in the art could easily use ammonia concentrations lower than 10M by providing other driving forces such as heat, long periods of exposure, and/or catalysts to drive the reaction, all of which are within the scope of the present invention. Generally, however, solutions of concentration of only 1M will cause hydrolysis of the saccharide protecting groups and may cause hydrolysis of the N 2 protecting groups. It is self-evident that ammonia may be considered a compound which in and of itself, provides an environment which promotes hydrolysis.
In a preferred aspect according to the present invention, the acyl group in the 6th position is substituted by a tertiary nitrogen of a tertiary nitrogen-containing compound and preferably pyridine. This includes compounds such as those derived from pyridine, like DMAP. The latter may be particularly useful in that it is fluorescent and may be used as an indication of the degree in which reactions have occurred, etc.
In accordance with another aspect of the present invention, processes of producing 2,6-diamino-9-[saccharide]purine are provided to include the steps of reacting a guanine nucleoside with a tertiary amine compound which is a pyridine and an acylating agent to form a first reaction product and subsequently reacting the first reaction product with concentrated aqueous ammonia to form a 2,6-diamino-9-[saccharide]purine.
More broadly, the process as described may include reacting a guanine nucleoside with a tertiary amine compound and an acylating agent to form a first reaction product wherein said reaction is conducted in an environment which is substantially free from compounds which promote hydrolysis, followed by reaction of the first reaction product with concentrated aqueous ammonia. In a preferred aspect of both of the above-described processes, the tertiary amine compound and the acylating agent are present in an amount effective to completely convert said guanine nucleoside to said first reaction product and the acylating agent is a reactive acid derivative. In accordance with a more preferred embodiment of the present invention, the reactive acid derivative is a substituted aliphatic acid anhydride substituted aliphatic acid halide or substituted phenol ester. More preferred are the reactive acid derivatives of mono-, di-, and tri-halogen substituted acetic anhydrides; and most preferred are the trifluoroacetic anhydride derivatives. However, any reactive acid derivative whose corresponding acid has a pK a lower than that of acetic acid may be used. It is preferred that the tertiary amine compound be present in an amount of between 3 and 20 ml per mmol of the guanine nucleoside and more preferably, in an amount of between about 5 to 10 ml per mmol of the guanine nucleoside. The reactive acid derivative should be present in an amount of at least 3 mmol per mmol of guanine nucleoside and preferably, between about 3 and about 8 mmol per mmol of said nucleoside.
As is appreciated by the present invention and apparently overlooked by the art, pyridine or other tertiary amine compounds may be used as both solvent as well as reactant. In principle, the amount of pyridine used, for example, can be quite low relative to the amount of guanine nucleoside, but at least the amount of pyridine or other tertiary amine should be a stoichiometric amount. It is hypothesized that acylation using an anhydride produces an ester and an equivalent of acid with each acid molecule protonating a molecule of pyridine or other tertiary amine compounds. Thus, at least stoichiometric amounts of both are required. If the amount of pyridine is drastically reduced, displacement reaction at the 6th position will suffer from a rate reduction as well as a reduction, potentially, in yield.
One molecule of anhydride, which will produce an electron withdrawing group corresponding to a carboxylic acid, having a pK a lower than that of acetic acid, is required for each sight of acylation. While it may be possible that as little as two molecules of acylating agent will be required for each guanine nucleoside (one each for the 6th and N 2 positions), it is likely that acylation of the N 2 position occurs at both protons. Thus, the N 2 position will be di-acylated at R2 and R3. This is particularly true where the acylating group is of a size that will not interfere sterically with the attachment of a second acyl group. Furthermore, because the processes in accordance with the present invention ideally contain highly electron withdrawing species at both the N2 and 6th positions, it is preferred that the N2 position be di-acylated. Therefore, at least three molecules of reactive acid derivative or acylating agent are preferably used for each mole of guanine nucleoside.
When R 4 is ribose and is unprotected in the 2', 3' and 5' positions, additional acylation occurs forming protecting groups at these positions. This requires the equivalence of at least three more molecules of acylating agent per molecule of guanine nucleoside. Additional acylating agent may be present to insure the formation of sufficient pyridyl ions to drive the reaction forward. Thus, it is preferred that an excess of stoichiometric acylating agent and pyridine or other tertiary amine be present. In accordance with a preferred aspect of the process described herein, the saccharides used as R 4 are beta-D-ribose and beta-D-2'-deoxyribose. It is also preferred that the reaction be conducted in the presence of a cooling medium such as, for example, an ice bath or cooling jacket. Temperatures of below 23° C. have found to be useful; and particularly, a temperature of 4° C. has been found to be highly preferred optimum.
In addition to the previously described reactions which are primarily useful for the formation of guanine nucleosides having an amino group in the 6th position, similar processes may be used for the formation of 6-substituted guanine nucleosides having a methoxy group in the 6th position.
In accordance with another aspect of the processes of this invention, guanine nucleosides substituted in the 6th position may be produced by providing a guanine nucleoside; acylating at least the 6th position thereof with an acylating agent; substituting a tertiary amine group for said acyl group in the 6th position of the guanine nucleoside, wherein the steps of acylating and substituting are conducted in an environment which is substantially free from compounds which promote hydrolysis; and substituting the tertiary amine group with a first nucleophile. A guanine nucleoside substituted in the 6th position is thus formed.
As discussed previously, the guanine nucleoside provided prior to use of the instant process may be saccharide protected (protected by saccharide protecting groups in all reactive positions on the saccharide, R 4 ). More importantly, however, the guanine nucleoside provided may be protected in at least one N 2 position by at least one N 2 protecting agent. These include the protecting agents previously discussed.
In accordance with another aspect of the present process, the guanine nucleoside provided may be unprotected in the N 2 position as well as in the active sites on the saccharide, R 4 . In these cases, the process step of acylation will also acylate the N 2 and reactive saccharide groups, thus protecting them from further reaction. Acylation occurs as previously described in that the reactive acid derivative, such as, for example, trifluoroacetic anhydride, reacts to form an acid and an ester. The acid protonates one molecule of the tertiary amine and the reactive acid derivative reacts with the oxo group in the 6th position of the guanine nucleoside to form an acyl group, in this case a trifluoroacetyl group. This group is subsequently displaced by the tertiary amine group.
When the compound to be produced is eventually to be used in the production of nucleotides, it is important that the step of acylation and substitution be conducted in an environment which is substantially free from compounds which promote hydrolysis of the N 2 protecting group. Otherwise, side reactions will occur which will drastically impact upon the speed and yield of the process of the present invention. Furthermore, reprotection would be required at a later date. The acylating agent should, as in all aspects of the processes of the present invention, be present in an effective amount to completely acylate at least the 6th position of the guanine nucleoside, and the tertiary amine group should be present in an amount effective to completely substitute the acyl group in the 6th position. When unprotected at the N 2 position, the amount of acylating agent should be an effective amount to acylate the N 2 position as well. If the saccharide is unprotected, the amount of acylating agent should be adjusted accordingly.
Generally, the tertiary amine compound should be present in an amount of between about 3 and about 20 mL per mmol of the guanine nucleoside, and most preferably in an amount of between about 5 to about 10 mL per mmol thereof. The reactive acid derivative from which the acyl group is derived should be present in an amount of at least three mmol per mmol of the guanine nucleoside, and preferably be present in an amount between about 3 and about 8 mmol per mmol of the nucleoside.
Following the steps of acylation and substitution, another substitution step is carried out wherein the tertiary amine group is substituted with a first nucleophile to form a guanine nucleoside substituted in the 6th position. While the guanine nucleoside/tertiary amine group complex is a guanine nucleoside substituted in the 6th position, it is not stable for long periods of time and is not considered to be within the meaning of the term as used herein.
The first nucleophile may be a nucleophile which, in and of itself, provides an environment which promotes hydrolysis. An example of a nucleophile of this type is ammonia. Therefore, the addition of concentrated ammonia at this stage in the process will drive the reaction directly to the formation of guanine nucleosides having an amino group in the 6th position. Yields have been found to be approximately 34% when the process is utilized in this form. The 6-amino-substituted guanine nucleoside would be deprotected in the N 2 position in this case.
In accordance with another embodiment of the present invention, a nucleophile may be substituted which does not promote hydrolysis of the N 2 position in and of itself, but whose substitution is conducted in the presence of other compounds which will promote hydrolysis. One example of such a substitution is the addition of DMAP accompanied by water, alcohol, or a less concentrated solution of ammonia. This will produce a guanine nucleoside which is deprotected at the N 2 position and which is substituted in the 6th position with DMAP.
Alternatively, the first nucleophile may be of a type which does not promote hydrolysis and is added for substitution without the presence of other compounds which will promote hydrolysis. In that eventuality, a N 2 protected 6-substituted guanine nucleoside will be produced. Nucleophiles according to this process protocol include tertiary amines, substituted phenoxy compounds having at least one electron withdrawing group attached thereto with the proviso that, if said electron withdrawing group is a halogen, a plurality of halogens are attached to said phenoxy group, and with the further proviso that the phenoxy does not contain a substituent at the 2 or 6 position of a size that will create steric hindrance.
In accordance with a preferred aspect of this protocol, the first nucleophile comprises a substituted or unsubstituted nitrophenoxy group having a nitro group in the 3, 4 or 5 position, a non-sterically hindered compound having a structure of the formula (II): ##STR19## wherein R 5 comprises a halogen or hydrogen and wherein at least three R 5 groups are halogens, or a tertiary amine such as DMAP or other dialkylaminopyridine.
These compounds are storage-stable and may be separated, purified and stored for later use. One such use involves the subsequent substitution of the nucleophile in the 6th position with a second nucleophile. Such a substitution may be accomplished in the absence of compounds which will promote hydrolysis in which case compounds with different 6-substitutions but which are protected in the N 2 position may be realized. For example, a compound having a pentafluorophenoxy group in the 6th position may be substituted with a second nucleophile, such as a 4-nitrophenoxy group, to produce a 4-nitrophenoxy substituted guanine nucleoside. This nucleoside may then be protected in, for example, the 3' and 5' positions of a ribose or deoxyribose attached as R 4 and inserted into RNA or DNA, respectively.
Furthermore, the substitution of the first nucleophile with the second nucleophile may be accomplished either in the presence of compounds which do promote hydrolysis or by using compounds which themselves promote hydrolysis. In this eventuality, 6-substituted guanine nucleosides which are deprotected in the N 2 position are realized, such as, 2,6-diamino-9-[saccharide]purine or 2-amino,6-methoxy-9-[saccharide]purine. These "second nucleophiles" may therefore comprise primary, secondary or tertiary amines, primary alcohols, H 2 S, thiols, NH 3 (concentrated) or any of the first nucleophiles identified above. These compounds may thereafter be purified.
Thus, the process of the present invention is highly versatile and provides a plurality of routes to accomplish realization of the same compounds. It should be noted, however, that the yields of, for example, the 2,6-diamino-9-[saccharide]purine are dramatically superior when using the two-step nucleophilic substitution of a first nucleophile and a second nucleophile when compared to the more direct tertiary amine displacement. In fact, yields may be quantitative.
In accordance with another aspect of the process of the present invention, a guanine nucleoside substituted in the 6th position may be produced by the steps of reacting a guanine nucleoside with a tertiary amine compound and an acylating agent to form a first reaction product wherein said reaction is conducted in an environment which is substantially free from compounds which promote hydrolysis; and thereafter reacting the first reaction product with a first nucleophile capable of binding at the 6th position of the guanine nucleoside. A guanine nucleoside substituted in the 6th position is thus formed. This 6th position substituted guanine nucleoside may be further reacted with a second nucleophile as previously described.
In accordance with this process the guanine nucleoside may be provided in an N 2 protected form or an unprotected form. If the guanine nucleoside is protected, then that amount of tertiary amine compound useful in accordance with this aspect of the present invention is preferably between about 2 and about 20 mL per mmol of the nucleoside and the acylating agent is preferably present in an amount of between about 1 and about 6 mmol per mmol of the guanine nucleoside.
When the guanine nucleoside is unprotected prior to being reacted with the tertiary amine compound and the acylating agent, the amount of tertiary amine compound present in the reaction is preferably between about 2 and about 20 mL per mmol of the guanine nucleoside and the acylating agent should be present in an amount of at least about 3 mmol per mmol of said guanine nucleoside. In a more preferred embodiment in accordance with this process, the tertiary amine compound should be present in an amount of between about 5 and about 10 mL per mmol of guanine nucleoside and said acylating agent should be present in an amount of between about 3 and about 8 mmol per mmol of said guanine nucleoside. The processes of the present invention, as noted before, are preferentially conducted in the presence of a cooling medium and are preferably conducted at a temperature below about 23° C., and most preferably at a temperature of about 4° C.
Finally, a process for producing 6-(nitrophenoxy)9[saccharide]purine wherein said nitrophenoxy has a nitro group in the 3, 4 or 5 position includes the steps of reacting a guanine nucleoside having a pyridinium ion or other tertiary amine compound in the 6th position thereof with a substituted or unsubstituted nitrophenol having a nitro group in the 3, 4 or 5 position. The process of producing a 6-(substituted)halo-phenoxy-9-[saccharide]purine is also provided comprising the step of reacting a guanine nucleoside having a pyridinium ion or other tertiary amine in a 6th position thereof with a non-sterically hindered compound having a structure of the formula of (II): ##STR20## wherein R 5 comprises a halogen or hydrogen and wherein at least three R 5 groups are halogens.
As will be readily appreciated by one of ordinary skill in the appropriate art, the various 6-substituted nucleosides may be separated from their respective reaction mixtures and purified by any number of conventional means such as those discussed in the references cited herein and in the examples which follow. One preferred method of purification includes neutralization of remaining acid species followed by evaporation, with the residue later being dissolved in water and purified by reversed-phase high pressure liquid chromatography (HPLC) using a gradient elution of from 2 to 5% acetonitrile in water. Other separation techniques exclude the use of neutralizing material and merely include the steps of evaporation of the product to dryness and redissolving the residue in water followed by filtering and washing.
The foregoing will be better understood with reference to the following examples. These examples are for the purposes of illustration. They are not to be considered limiting as to the scope and nature of the present invention.
EXAMPLE I
Production of 2-amino-6-methoxy-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine.
To 2 mmol of deoxyguanosine, dried by evaporation of pyridine and suspended in 10 mL of dry pyridine was added dropwise 2.3 mL (16 mmol) of trifluoroacetic anhydride, with cooling in an ice both. After ten minutes a suspension of 4.3 g of sodium methoxide in 300 mL of methanol was added dropwise. After a further 24 hrs, the mixture was treated with a solution of pyridine hydrochloride (12 mL of pyridine/4 mL conc HCl). The excess acid was destroyed by addition of 2 g of sodium bicarbonate and the mixture was evaporated to dryness. The residue was dissolved in water and purified on a Dynamax reversed-phase hplc column using a gradient of 2-5% acetonitrile in water in 45 min at a flow rate of 6 mL/min. Evaporation of appropriate fractions gave 0.36 g (60%) of pure 2-amino-6-methoxy-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine. A crystalline sample was obtained by crystallization from water, mp 155°-7°. UV max (MeOH) 281 nm; UV min 281 nm; 1 H NMR (DMSO-d 6 ) delta (ppm) 8.07 (s, 1,H 8 ), 6.43 (br s, 2, NH 2 ), 6.20("t", 1, J app =6.9 Hz, H 1' ), 5.27 (d, 1, J=3.8 Hz, 3'-OH), 4.98 (t, 1, J=5.5 Hz, 5'-OH) , 4.35 (m,1,H 3' ), 4.00 (s, 3, OCH 3 ), 3.82 (m, 1, H 4' ), 3.53 (m, 2, H 5' ,5'), 2.57 & 2.22 (m & m, 1 & 1, H 2' & H 2" ). Anal. Calcd. for C 11 H 15 N 5 O 4 .H 2 O: C, 44.15; H, 5.72; N, 23.40. Found: C, 44.15; H, 5.83; N, 23.43.
EXAMPLE II
Production of 2-amino-6-methoxy-9-[2-deoxy-3,5-bis-O-(tert-butyldimethylsilyl)-Beta-D-erythro-pentofuranosyl]purine).
To 6 mmol of 3',5'-bis-tert-butyldimethylsilyl-deoxyguanosine, dried by evaporation of pyridine and dissolved in 60 mL of dry pyridine was added dropwise 3.0 mL (21 mmol) of trifluoroacetic anhydride, with cooling in an ice bath. After stirring for 15 minutes a suspension of 5.7 gm of sodium methoxide in 610 mL of methanol was added in portions. After a further 20 hrs the reaction mixture was poured into 500 mL of water. The mixture was partitioned using four 200 mL portions of petroleum ether. The combined organic layers were evaporated, traces of pyridine were removed by evaporation of toluene and the resulting foam was dissolved in 50 mL of petroleum ether and placed in the cold. Crystallization gave, after filtration, 2.4 gm (80%) of 2-amino-6-methoxy-9-[2-deoxy-3,5-bis-O-(tert-butyldimethylsilyl)-Beta-D-erythro-pentofuranosyl]purine) mp 101°-105° d. UV max (MeOH) 250 nm, UV min 283 nm; 1 H NMR (CDCI 3 ) delta (ppm) 7.90 (s, 1, H 8 ), 6.30 ("t", 1, J app =6.6 Hz, H 1' ), 4.81 (s, 2, NH 2 ), 4.57 (m, 1, H 3' ), 4.01 (s, 3, OCH 3 ), 3.96 (m, 1, H 4' ), 3.77 (m, 2 , H 5' ,5"), 2 .55 & 2.38 (m & m, 1 & 1, H 2' & H 2" ), 0.89 & 0.06 (m & m, 9 & 9, Me 3 CSi). Anal. Calcd. for C 23 H 43 N 5 Si 2 O 4 : C, 54.18; H, 8.50; N, 13.73; Si, 11.01. Found: C, 54.05; H, 8.63; N, 13.80; Si, 10.69.
EXAMPLE III
Production of 2-amino-6-ethoxy-9-[2-deoxy-3,5-bid-O-(tert-butyldimethyslsiyl)-Beta-D-erythro-pentofuranosyl]purine).
To 2 mmol of 3',5'-bis-tert-dimethylsilyldeoxyguonosine, dried by evaporation of pyridine and suspended in 50 mL of dry pyridine was added dropwise 1.0 mL (7mmol) of trifluoroacetic anhydride, with cooling in an ice bath. After 15 minutes a solution of 2.3 gm of sodium ethoxide in 1.75 L of absolute ethanol was added in portions. After a further 60 hours the mixture was concentrated to about 800 mL and poured into 600 mL of cold water. The mixture was filtered and partitioned using five 200 mL portions of petroleum ether. Crystallization from petroleum ether as described above for 6a, gave 540 mg (51%) of 2-amino-6-ethoxy-9-[2-deoxy-3,5-bid-O-(tert-butyldimethyslsilyl)-Beta-D-erythro-pentofuranosyl]purine, mp 120°-124° d. UV max (MeOH) 250 nm, UV min 283 nm; 1 H NMR (CDCI 3 ) delta (ppm) 7.9(s, 1, H 8 ), 6.33 ("t", 1, J app =6.6 Hz, H 1' ), 4.80 (s, 2, NH 2 ), 4.59 (m, 1, H 3' ), 4.54 (q, 2, J=7, CH 2 ), 3.87 (m, 1, H 4' ), 3.79 (m, 2, H 5' ,5"), 1.46 (t, 3, CH 3 ), 2.55 & 2.38 (m & m, 1 & 1, H 2' & H 2' ), 0.91 & 0.06 (m & m, 9 & 9, Me 3 CSi) . Anal. Calcd. for C 24 H 45 N 5 Si 2 O 4 : C, 55.03; H, 8.65; N, 13.36. Found: C, 54.97; H, 8.83; N, 13.36.
EXAMPLE IV
Production of 2,6-diamino-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine.
To 2 mmol of deoxyguanosine, dried by evaporation of pyridine and suspended in 20 mL of dry pyridine was added dropwise 2.3 mL (16 mmol) of trifluoroacetic anhydride, with cooling in an ice bath. After ten minutes 20 mL of cold, concentrated aqueous ammonia was added. After a further 11/2 hours the mixture was evaporated to dryness, the residue dissolved in water and the solution filtered through a 100 mL portion of Bio Rad AG 1-X2, hydroxide from resin to remove colored impurities. The resin was washed with 40% methanol in water to elute crude 2,6-diamino-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine, which was further purified on the reversed-phase column described above using a gradient of 2-15% acetonitrile in water. Evaporation of appropriate fractions gave 192 mg (34%) of 2,6-diamino-9-(2-deoxy-D-erythro-pentofuranosyl)purine, a sample crystallized from water gave a mp of 148°. UV max (MeOH) 282 nm, UV min 256 nm; 1 H NMR (DMSO-d 6 ) delta (ppm) 7.91 (s, 1,H 8 ), 6.73 (br s, 2, NH 2 ), 6.17 ("t", 1, J app =6 Hz, H 1' ), 5.73 (br s, 2, NH 2 ), 5.25 (m, 2, 3'-OH & 5'-OH), 4.35 (m, 1, H 3' ), 3.84 (m, 1, H 4' ), 3.54 (m,2,H 5' ,5"), 2.59 & 2.17 (m & m, 1 & 1, H 2' & H 2" ). Anal. Calcd. for C 10 H 14 N 6 O 3 .H 2 O: C, 42.25; H, 5.67; N, 29,56. Found: C, 42.54; H, 5.33; N, 29.56.
EXAMPLE V
Production of 2-N-trifluoroacetamido-6-(4-nitrophenoxy)-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine.
To 4 mmol of deoxyguanosine, dried by evaporation of pyridine and suspended in 60 mL of dry pyridine was added dropwise 3.4 mL (24 mmol) of trifluoroacetic anhydride, with cooling in an ice bath. After 15 minutes a solution of 11.1 g (80 mmol) of 4-nitrophenol in 200 mL of pyridine was added. After a further 48 hours the mixture was concentrated to about 150 mL and poured into 600 mL of water. The mixture was partitioned using four 200 mL portions of ethyl acetate. The combined organic layers were backwashed with three 50 mL portions of water, concentrated to about 15 mL, toluene was added and the mixture was concentrated to a gum which was dissolved in ethyl acetate, filtered and added dropwise to a 400 mL portion of toluene. Filtration and washing with petroleum ether gave 1.3 g (67%) of 2-N-trifluoroacetamido-6-(4-nitrophenoxy)-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine. UV max (MeOH) 271; 1 H NMR (DMSO-d 6 ) delta (ppm) 12.12 (br s, 1, NH), 8.72 (s, 1,H 8 ), 8.34 & 7.69 (dd, 4, J=9.1 Hz, C 6 H 4 NO 2 ), 6.41 ("t", 1, J app =6.7 Hz, H 1' ), 5.35 (d, 1, J=4.2 Hz, 3'-OH), 4.91 (t, 1, J=5.5 Hz, 5'-OH), 4.50 (m, 1, H 3' ), 3.88 (m, 1, H 4' ), 3.57 (m,2,H 5' ,5"), 2.78 & 2.40 (m & m, 1 & 1, H 2' & H 2" ). Anal. Calcd. for C 18 H 15 N 6 F 3 O 7 : C, 44.63; H, 3.12; N, 17.35; F, 11.77. Found: C, 44.80; H, 3.13; N, 17.20; F, 11.30.
EXAMPLE VI
Production of 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine.
To 4 mmol of deoxyguanosine, dried by evaporation of pyridine and suspended in 60 mL of dry pyridine was added dropwise 3.4 mL (24 mmol) of trifluoroacetic anhydride, with cooling in an ice bath. After 15 minutes a solution of 9.6 g (52 mmol) of pentafluorophenol in 200 mL of pyridine was added. After a further 24 hrs the mixture was concentrated to about 150 mL and poured into 500 mL of water. The mixture was partitioned using four 200 mL portions of ethyl acetate. The combined organic layers were washed with three 50 mL portions of water, concentrated to a gum, which was dissolved in about 15 mL of ethyl acetate, and the product precipitated by dropwise addition of this solution to 700 mL of petroleum ether. Filtration gave 2.0 g (95%) of 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine. An analytical sample of 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-Beta-D-erythro-pentofuranosyl)purine was obtained by treatment with carbon and reprecipitation. UV max (MeOH) 268 nm; 1 H NMR (DMSO-d 6 ) delta (ppm) 12.1 (br s, 1, NH), 8.80 (s, 1,H 8 ), 6.42 ("t", 1, J app =6.7 Hz, H 1' ), 5.38 (m, 1, 3'-OH), 4.90 (m, 1, 5'-OH), 4.20 (m, 1, H 3' ), 3.90 (m, 1, H 4' ), 3.55 (m, 2, H 5' ,5"), 2.80 & 2.38 (m & m, 1 & 1, H 2' & H 2" ). Anal. Calcd. for C 18 H 11 N 5 F 8 O 5 .3/4 H 2 O: C, 39.83; N, 12.90; F, 28.00. Found: C, 39.38; H, 2.03; N, 12.60; F, 25.56. ##STR21##
EXAMPLE VII
(H-Phosphonate Method)
With reference to the above formula (B), the pentafluorophenyl 6-substitued guanine nucleoside 1 was converted to the 5'-DMT-3'-phosphonate derivative 3 by standard procedures as follows: 1 was first reacted with a slight excess of 4,4'-dimethoxytrityl chloride (DMT-Cl) in pyridine solution (about 5-10 mL per mmol of 1) using a catalytic amount (0.05 eq) of 4-dimethylaminopyridine (DMAP). This resulted in a 5'DMT-6-pentafluorophenoxy-guanine nucleoside 2. A solution of 2 dissolved in methylene chloride (about 10-20 mL per mmol2) was added dropwise to a cooled (ice bath) methylene chloride solution of PCL 3 , N-methyl morpholine and 1,2,4-triazole in the ratios of 10 mL of CH 2 Cl 2 per mmol of PCL 3 , 5 mmol of PCl 3 , per mmol of 2, 46 mmol of N-methyl morpholine per mmol of 2, and 3.3 mmol of triazole per mmol of PCl 3 ). This resulted in the formation of 5'DMT-3'-phosphonate-6-pentafluorophenoxy-guanine nucleoside, 3. An oligonucleotide was then prepared using 3 which had a sequence of d[TT(PFPG)TT], where d(PFPG) is pentafluorophenyl-2'-deoxyguanosine by the following protocol:
1. Wash, CH 2 Cl 2 : 20 sec wash, 10 sec wait, repeat 7 times.
2. Deblock, 2.5% dichloroacetic acid, purines: 20 sec acid, 10 sec wait, 40 sec acid; pyrimidines: 20 sec acid, 20 sec wait, then 10 sec acid, 40 sec wait, repeat last two steps three times.
3. Wash, CH 2 Cl 2 : 50 sec.
4. Wash, pyridine/CH 3 CN (1/1): 20 sec wash, 10 sec wait, repeat five times.
5. Couple: 0.5 sec 15 mM H-phosphonate, 0.5 sec 75 mM or 0.3 sec 125 mM pivaloyl chloride, repeat as described.
6. Wash, pyridine/CH 3 CN (1/1): 20 sec wash, 10 sec wait, repeat five times.
7. Deblock, or repeat from step 1 until completed, or cap: 0.5 sec 50 mM 4, 0.5 sec 250 mM pivaloyl ts chloride, repeat 179 times, wash as step 4, then repeat from step 1 until completed.
8. Oxidize: 0.5 sec 0.4M I 2 in THF, 0.5 sec pyridine/N-methylimidazole/water/THF (10/2/10/78), 40 sec wait, repeat 30 times; 0.5 sec 0.4M I 2 in THF, 0.5 sec triethylamine/water/THF (10/10/80), 40 sec wait, repeat 30 times.
9. Removal from CPG: The CPG was treated with 1.0M aqueous ammonia for 12 hours at room temperature, filtered and concentrated.
10. The compound is heated in concentrated ammonia for about 24 hours to form the 2,6-diamino derivative
EXAMPLE VIII
Using the procedure of Example VII above up through Step 9, other substituted oligonucleotides may be formed by reaction of the PFPG residue(s) with the other nucleophiles indicated above. For example, heating at 55° with an aqueous solution containing excess DMAP for 48 hours brings about formation of the fluorescent 6-DMAP labeled oligonucleotide, while similar treatment with an ethanolic solution of NaSH or sodium thiophenoxide gives the corresponding 6-S derivatized molecules. ##STR22##
EXAMPLE IX
Beta-Cyanoethyl Phosphoramidite Method.
With reference to the above formula (C) 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite is first produced by the following procedure:
To 61 mL of freshly distilled phosphorus trichloride (0.70 mol) dissolved in 300 mL of anhydrous diethyl ether (previously dried over molecular sieves), which was stirred mechanically under a N 2 atmosphere and maintained at -30° C., was added dropwise over 2 hours a mixture of 57 mL (0.70 mol) of pyridine, 48 mL (0.70 mol) of freshly distilled 3-hydroxypropionitrile, and 50 mL of anhydrous diethyl ether. The cooling bath was removed, and the mixture was stirred for 18 hours under a small positive N 2 pressure. The ether solution was transferred under N 2 pressure with filtration into a dry flask. The remaining pyridinium hydrochloride was washed twice with 100-mL portions of anhydrous diethyl ether which was transferred as above. The solution was concentrated on a rotary evaporator, and the resulting liquid was distilled under vacuum (500-1000 mT) with a falling-film distillation apparatus with refluxing ethyl acetate as the heat source to give 70 g (0.41 mol, 58%) of 2-cyanoethyl dichlorophosphite. The 31 P NMR (CDCI 3 ) showed a single peak at 178.8 ppm (reference 85% H 3 PO 4 ).
To 28 g (163 mmol) of this compound dissolved in 300 mL of anhydrous diethyl ether and stirred under N 2 at -20° C. was added dropwise 96 mL (685 mmol, 4.2 equiv) of diisopropylamine. The ice bath was removed, and the mixture was stirred for 1 h. The ether solution was transferred with filtration under N 2 pressure to a dry flask. The remaining salt was washed twice with 70-mL portions of anhydrous ether which was transferred as above. The solution was concentrated on a rotary evaporator and filtered into a small, dry flask. The liquid was stirred under vacuum for 20 min and then distilled under vacuum (400-500 mT) with the falling-film distillation apparatus with refluxing toluene as the heat source to give 18.5 g (61 mmol, 37% yield) of clear, colorless product. The 31 P NMR (CDCI 3 ) spectrum showed a single peak at 123.6 ppm (reference 85% H 3 PO 4 ).
Compound 2 from Example VII, (5-DMT-6-pentafluorophenoxy-guanine-nucleoside) was then reacted with the 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite prepared above. Specifically, nucleoside 2, dissolved in dry acetonitrile (5 mL per mmol), was treated with tetrazole (5 eq), diisopropylamine (7 eq), and after five minutes between 1.1 and 1.3 eq of the 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite was added. Product was purified by the following procedure:
After 1 hour, the mixture was partitioned between 200 mL of 5% aqueous NaHCO 3 and 200 mL of methylene chloride. The organic layer was washed with a 100-mL portion of water and was then concentrated to a gum. The crude product was purified by flash chromatography on silica gel using a step gradient of 10-25% ethyl acetate in methylene chloride. The appropriate fractions were combined and evaporated to a solid foam. This resulted in the production of a guanine nucleoside protected in both the 5' and 3' positions, nucleoside 4.
An oligonucleotide was then produced by the following protocol:
5'-DMT-thymidine bound to controlled pore glass (CPG) was treated sequentially with: 1) 2% dichloroacetic acid to cleave the DMT group); 2) a solution of 0.16M tetrazole in acetonitrile (20-32 eq) and 0.04M of nucleoside 4 (5-8 eq) in acetonitrile (coupling); 3) a solution of 0.016M of I 2 in 89% tetrahydrofuran (THF), 10% water, and 1% pyridine, for 30 sec. (oxidation); 4) a mixture containing 5% DMAP, 5% pyridine, 8% acetic anhydride and 82% THF for 11 sec. (capping). This cycle was then repeated using 5'-DMT-thymidine-3'-phosphonate in place of nucleoside 4, to give as the final product d[T(PFPG)T]. This compound was converted to d[T(2-NH 2 -A)T] by heating in concentrated aqueous ammonia for 24-48 hours.
EXAMPLE X
Synthesis of 2-amino-6-(4-dimethylaminopyridyl)-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine.
To 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2deoxy-beta-D-erythro-pentofuranosyl)purine dissolved in water or aqueous pyridine was added excess 4-dimethylaminopyridine and the mixture was heated at about 50° for one hour to give quantitative conversion to the product. ##STR23##
EXAMPLE XI
Synthesis of 6-thio-2'deoxyguanosine.
To 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine dissolved in ethanol was added excess sodium hydrogen sulfide. After heating at reflux for 2-6 hours, conversion to the product was complete. ##STR24##
EXAMPLE XII
Synthesis of 6-phenylthio-2'-deoxyguanosine.
To 2-N-trifluoracetamido-t-pentafluorophenoxy-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine dissolved in ethanol was added excess thiophenol and base, such that the number of mmol of base was less than the number of mmol of thiophenol. After heating at reflux for 2-6 hours, conversion to the product was complete. ##STR25##
EXAMPLE XIII
Synthesis of N 6 -benzyl-2'-deoxyguanosine.
The 2-amino-6-(4-dimethylaminopyridyl)-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine was suspended in excess benzylamine and heated at 50° for 20 hours to give complete conversion to the product. ##STR26##
EXAMPLE XIV
Synthesis of O 6 -methyl-2'-deoxyguanosine.
To 2-amino-6-(4dimethylaminopyridyl)-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine or 2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-beta-D-erythro-pentofuranoxsyl)purine dissolved or suspended in methanol was added excess base, either triethylamine for the former or DBU (1,8-diazabicyclo[5.4.0]undec-7-ene] for the latter. After stirring at room temperature for several days or heating to 50° complete conversion to the product was effected. ##STR27##
The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular embodiments disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the spirit and scope of the invention.
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The following species of N6-activated guanosine derivatives are disclosed:
2-N-trifluoroacetamido-6-(4-nitrophenoxy)-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine
2-N-trifluoroacetamido-6-pentafluorophenoxy-9-(2-deoxy-beta-D-erythro-pentofuranosyl)purine
6-dimethylpyridinium-9-(2-deoxy-beta-D-erythropentofuranosyl)purine
These guanosine compounds are useful as precursors in the synthesis of a wide variety of antiviral and anticancer nucleosides such as 2-amino-2-deoxyadenosine or 6-thio-deoxyguanosine. Also disclosed are oligonucleotides containing the above nucleosides which are precursors to modified oligonucleotides which are useful as hybridization probes.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the United States national phase of International Application No. PCT/EP2014/001006 filed Apr. 15, 2014, and claims priority to European Patent Application Nos. 13002005.0 and 13004350.8 filed Apr. 17, 2013 and Sep. 5, 2013, respectively, the disclosures of which are hereby incorporated in their entirety by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a fibre optic based intrusion sensing system comprising at least one fiber optic cable buried in a shallow trench in the ground, a fibre optic interrogator measuring a predetermined property related to a change in the length of the cable and a control unit, wherein the cable having one end connected to an interrogator and a free second end at the end of the monitored perimeter, wherein the control unit is connected to the interrogator and adapted to analyse the measurements of said predetermined property and adapted to detect the presence of a specific object on the surface near the perimeter and identify the type of the object.
Description of Related Art
U.S. Pat. No. 5,194,847 A by Taylor and Lee discloses an apparatus for sensing intrusion into a predefined perimeter using buried fibre optic cables. The fiber optic cable is placed along a predefined perimeter which shall be monitored. The used apparatus roughly consists of a light source, an interferometer and a photodetector, which is able to detect the change of the backscattered light in an optical fiber. This change is interpreted as an intrusion. Using the time of flight of the light pulse in the fiber allows for locating the intrusion.
WO 2011/058312 A2 by Hill D. J. and McEwen-King M. describes a method for distributed sensing comprising a plurality of longitudinal sensing portions, which are all located along one cable. The different sensing portions are used to measure different sensing functions.
WO 2012/022934 A2 by McEwen-King M., Hill D. J. and Godfrey A. describes a system for the detection of moving objects based on distributed acoustic sensing along one buried fibre optic cable. The object is detected via the acoustic signal it produces during the movement over the fibre optic cable.
US 2012/130930 A1 by Klar et al. discloses a system, where one fibre optic cable is buried in a shallow trench and in deep boreholes to detect underground tunneling. The effect of tunnel excavation on the strains in the fiber optic cables is investigated. It is stated that surface loads may induce strains in a buried cable at a shallow depth which may disturb the signal caused by the tunneling. Tests with different surface loads were performed and the corresponding strain in one cable was measured. No attempt was made to identify the loads on the surface using the strain along the cable.
U.S. Pat. No. 4,482,890 A by Forbes G. et al. discloses an intruder detection system using a cable containing several parallel fibres wherein the fibres are placed in contact to each other. The cable with multiple fibres is used as a microbend sensor to measure compression of the soil due to an intruder.
Juarez J. C., Maier E. W., Choi K. N., and Taylor H. F. have published a paper “Distributed fiber-optic intrusion sensor system” in Journal of Lightwave Technology, vol. 23, pp. 2081-2087, 2005. Juarez J. C., Taylor H. F. have published a paper “Field test of a distributed fiber-optic intrusion sensor system for long perimeters”, Applied Optics, Vol. 46, Issue 11, pp. 1968-1971, 2007. Park J., Lee W. and Taylor H. F. have published a paper “A fiber optic intrusion sensor with the configuration of an optical time domain reflectometer using coherent interference of Rayleigh backscattering” in Proc. SPIE, 3555, 49-56, 1998. Juarez et al. as well as Park et al. at Texas A&M University improved the perimeter intrusion detection system based on U.S. Pat. No. 5,194,847 A. Klar A., Linker R. have also published a paper “Feasibility study of automated detection of tunnel excavation by Brillouin optical time domain reflectometry”, Tunneling and Underground Space Technology 25, 575-586, 2010. These authors also showed applicability of the system for intrusion detection and localization of the intruder in laboratory and field tests.
Madsen C. K., Bae T., Snider T. have published “Intruder Signature Analysis from a Phase-sensitive Distributed Fiber-optic Perimeter Sensor” in Fiber Optic Sensors and Applications V, Proc. of SPIE Vol. 6770, 67700K, 2007. A further publication is from Madsen C. K., Snider W. T., Atkins R. A., and Simcik J. C. as “Real-Time Processing of a Phase-Sensitive Distributed Fiber Optic Perimeter Sensor” in Proc. SPIE, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense VII, vol. 6943, no. 6943-36, 2008. These two publications, Madsen et al. (2007) and Madsen et al. (2008), show that these groups were able to extract a vibration signature of the intruder from the measured data by signal processing using the technology based on U.S. Pat. No. 5,194,847 A. This signature allows for a distinction between different intruders (e.g. a pedestrian and a car). The signature showed for a car, however, might be also caused by other machines or vehicles. Furthermore they managed to do the signal processing to provide the signature of the intruder in real-time.
Kirkendall C. K., Bartolo R., Salzano J., Daley K. have shown with their publication, “Distributed Fiber Optic Sensing for Homeland Security” in Naval Research Laboratory, Washington D.C., 2007, that they had developed their own distributed fiber optic sensing system to monitor intrusion of a perimeter and borders. In their system the fiber optic cable works as distributed seismic sensor. The intruder induces seismic waves in the subsoil which are detected along the cable. In field tests they show applicability to detection and localization of the intruder in the same way as the system used by Madsen et al. (2007).
SUMMARY OF THE INVENTION
All currently available and published perimeter intrusion detection systems, using one buried fiber optic cable, are able to detect and localize an intruder on the surface, while the system developed at Texas A&M University, Madsen et al. (2007) is even able to extract a signature of the intruder out of the measured data. However, none of these systems is capable to clearly identify the objects on the ground surface.
Based on this prior art it is an aim of the present invention to provide a secure object identification upon detection of an intrusion signal.
It is further within the reach of the present invention to measure accurately any property related to a change in length of buried fibre optic cables and to use these measurements in order to detect and identify any object on the ground surface.
A fibre optic based intrusion sensing system can comprise two or more parallel fiber optic cables buried in a shallow trench in the ground in such a way that the fibre exhibits the same displacements as the surrounding material of the ground. This feature can be realized using tight buffered cables with outer diameters of approx. 1-10 mm and low tensile stiffness. The fibres have to be chosen to exhibit the same displacements as the surrounding soil (e.g. slip), otherwise the inverse analysis is not optimum and very accurate because according to the simplest embodiment one does not measure soil deformations. They are buried side by side with a defined nonzero distance to each other at predetermined depths, each of them having one end connected to an interrogator and a free second end at the end of the monitored perimeter.
The invention is inter alia based on the insight that the use of a combination of simultaneous measurements of two or more parallel buried fibre optic cables is essential to enable a quick and simple identification of objects on the ground surface. The invention uses a mechanical model and mechanical inverse analysis to back-calculate the contact forces acting on the ground surface. The mechanical inverse analysis uses a mathematical model of the ground as a solid half space, loaded with arbitrary forces on its surface. This mathematical model is capable of mapping the forces acting on the surface to the distinct displacement field of the whole half space formed by the ground. This displacement field is evaluated along fictitious lines in the half space where the fibre optic cables are located. Strains are calculated out of the displacements by differentiating the displacements with respect to the spatial coordinate along the fictitious cable. This calculated strain using the mathematical model of the half space is compared to the measured strains along the buried fibre optic cables and the forces acting on the surface are optimized by minimizing the error between the measured and the calculated strains, e.g. least squares optimization. One of the systems according to the invention uses the position and the magnitude of these contact forces to identify the object on the surface.
Compared to the above mentioned prior art systems the present invention uses the simultaneous measurements in two or more buried fibre optic cables and allows the application of a mechanical model of the contact problem between any object on the surface and the ground to perform a mechanical inverse analysis and identify the location and the magnitude of the contact forces acting on the ground surface with high temporal resolution.
A system for detecting intrusion and identifying the intruding object at any location along a large perimeter using ground buried fiber optic cables is as such disclosed. The fiber optic cables, together with a fiber optic sensing interrogator work as distributed dynamical strain sensors, which measure a property of the fibre cable indicating a change in the length of the fibre. Two or more parallel buried cables are used to measure the strains in the ground produced by an object on the surface. The measurements of all the cables are combined and analysed. By applying mechanical inverse analysis of the contact problem between the object and the continuum half space formed by the ground, the load over time on the surface is back-calculated. The back-calculated load pattern over time on the surface allows for a distinct identification of the intruding object on the surface
In other words, the present invention relates to a buried fibre optic perimeter monitoring system and method for object identification. Tight buffered fibre optic cables are buried in a shallow trench in a predetermined way. A fibre optic interrogator is provided to be used to measure any property related to a change in the length of the fibre. The measurements are used to calculate the corresponding contact forces over time between the object and the ground surface. Different types of objects are correlated to the pattern of the contact forces over time. Object identification provides an alarm system to identify threatening intrusions of a secured perimeter and allows preventing false positives.
The invention relates to a perimeter monitoring system composed of buried fibre optic cables. With a fibre optic interrogator any property related to a change in length of the fibre is measured with high accuracy (˜1 microstrain=1 μm/m), high spatial resolution (˜1-20 millimeter) and high frequency (˜50-1000 Hz). The change in the length of the fibre can be measured with any fibre optic sensing technology (e.g. Swept wavelength interferometry to measure the Rayleigh backscatter, Frogatt and Moore (1998); Brillouin optical time domain analysis, Nikles (2007), etc.). An object on the ground surface induces a distinct displacement field in the ground. Due to these displacements of the ground, the buried cables are strained. This strain is measured and when exceeding a predefined threshold is exceeded, the system emits an alarm that the perimeter had been crossed by any object and provides information about the type of the object.
The buried fibre optic cables are tight buffered, i.e. the coating of the fibre made from synthetic plastic material and or a possible metal coating is connected tightly to the glass fibre. This ensures the strain of the coating to be coupled to the strain in the fibre and allows measuring the true ground displacements due to an object on the ground surface along a line with high precision.
The measurement of the ground displacement along the fibre optic cables allows for an inverse calculation of the forces acting on the ground surface. This inverse analysis is done using a mechanical model of the contact problem between the object and the ground surface. Depending on the ground, more or less sophisticated constitutive laws for the mechanical model are required (e.g. linear isotropic elasticity, Boussinesq (1885); linear cross-anisotropic elasticity; non-linear elasticity, Puzrin and Burland (1996); elasto-plastic constitutive laws). The result of the inverse analysis is a pattern of contact forces on the surface over time and is represented by the location and the magnitude of the contact forces for each measurement time.
The mechanical model may be calibrated in advance to improve the accuracy of the inverse analysis. The calibration procedure is performed in the field and involves static or dynamic loading of the ground surface above the secured perimeter with predefined objects (e.g. vehicle driving along the perimeter, placing a defined weight at defined locations along the perimeter). The parameters of the mechanical model are then optimized in such a way that the difference between the theoretical predicted and the measured strains are minimized. The calibrated mechanical model allows for an improved identification of the location and the magnitude of the contact forces between the object and the ground surface.
Different objects moving on the surface produce different patterns of contact forces over time. Using the inverse calculated pattern of contact forces over time, a correlation of different object types is done. With this procedure the objects moving or standing on the perimeter containing the buried fibre optic cables are identified.
When one or more fibre optic cables are placed in a loop, then the arms of the loop can be provided parallel to each other in one trench with a defined nonzero distance to each other a and in a defined depth, wherein each arm of the loop has the same function as one cable. In the inverse analysis, the date of each arm of the loop is used as if it was one cable of different cables provided in parallel one to the other
In another embodiment the loop is formed based on two or more cables. Then an entire closed perimeter can be monitored and any cut through one or more cable would still allow monitoring the perimeter based on a plurality of cables having then “free ends” at the location of the trench. Of course, this necessitates the provision of a detection routine and a change of the monitoring surveillance.
The control unit can analyse the measurements and identify objects on the surface by combining the measurements of all the parallel cables and performing mechanical inverse analysis in order to calculate the dynamic contact forces acting between the object and the ground surface and using the calculated pattern of contact forces over time and correlate it to the type of object on the surface, the location of the object on the perimeter, the weight of the object, the speed of the object and the direction of the object. Wherein the prior art provides only the detection of the object using the measured signal in the cable, here the step using the mechanical inverse analysis is added and the correlation to the type of the object is done depending on the back-calculated contact force pattern over time.
According to a further preferred embodiment the control unit receives further calibration signals based on the mechanical inverse analysis in advance in time by moving defined objects over the surface and using the knowledge of the objects (e.g. weight, location, speed, direction of movement) as input. Then the parameters of the mechanical model use for the inverse analysis are calibrated, wherein this calibration process is done in the laboratory on a standardized soil used to refill the trench in the field. The situation of the cables, distances a and heights h are not important due to the fact that soil parameters are independent to this situation. Any placing of the cables will allow to calibrate these soil parameters and will lead to the same soil parameters.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,
FIG. 1 shows a schematic sketch of a perimeter to be monitored with a perimeter monitoring system comprising two or more buried cable around a sensitive facility
FIG. 2 shows a schematic sketch of a perimeter monitoring system with three parallel buried fibre optic cables for the situation of FIG. 1 ;
FIG. 3 shows a schematic sketch of a perimeter monitoring system with one cable placed in serpentines for the situation of FIG. 1 ;
FIG. 4 shows a schematic sketch of a perimeter monitoring system with one buried fibre optic cable placed in a loop for the situation of FIG. 1 ;
FIG. 5A to 5C show different cross-sections of shallow trenches containing the buried fibre optic cables according to different embodiments according to FIG. 1 ;
FIG. 6A to 6C show a schematic sketch of the mechanical inverse analysis with a representation of an object, the measured strain and the calculation steps;
FIG. 7 shows a schematic procedure of inverse analysis using the data of three strain measurements along parallel buried fibre optic cables;
FIGS. 8A & 8B shows a schematic sketch of the inverse calculated contact force pattern on the surface for a pedestrian crossing the perimeter with three buried fibre optic cables; and
FIG. 9A to 9C shows different strain measurements along three parallel buried fibre optic cables with a pedestrian crossing the perimeter.
DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic sketch of a perimeter to be monitored with a perimeter monitoring system comprising two or more buried cable around a sensitive facility 1 . Such a perimeter monitoring system can also be described as a fibre optic based intrusion sensing system.
The sensitive facility 1 , which has to be secured, is hosting a fibre optic interrogator and a control unit. The secured perimeter 2 is monitored with at least two buried fibre optic cables 10 in each cross section (see FIGS. 2 to 5 ). The arrangement of the cables may vary (see FIGS. 2 to 5 ), e.g. can comprise free ends or being provided as a loop for each cable.
The feed cable 3 runs from the interrogator 13 and control unit 14 to the secured perimeter 2 . An object 4 , which has to be identified, is crossing the perimeter 2 with the buried fibre optic cables from outside 5 the perimeter towards inside 6 the perimeter. Of course, it is not mandatory but preferred to provide the interrogator 13 and control unit 14 in a distance from the secured perimeter 2 on the inside 6 to avoid direct access to the cables 10 before detection. Of course the system is also capable to detect a movement from the inside 6 to the outside 5 , which can be interesting if a long not-closed line, like a border, is to be monitored.
FIG. 2 shows a schematic sketch of a perimeter monitoring system with three parallel buried fibre optic cables 10 for the situation of FIG. 1 . Two (continuous lines) or more (dashed line) fibre optic cables 10 are buried in a shallow trench 15 (see FIG. 5 ) in the ground 16 . The fibre optic cables 10 have free ends 11 . A further and opposite end 12 of each fibre optic cable 10 is connected to a dynamic distributed fibre optic interrogator 13 . A control unit 14 is combining the measurements of all the cables 10 and identifying the object 4 on the ground surface 20 .
FIG. 3 shows a schematic sketch of a perimeter monitoring system with one or more buried fibre optic cable 10 placed in a serpentine for the situation of FIG. 1 . The bends of the serpentine are placed at the start and the end of the perimeter respectively, such that the cable crosses each cross-section (see FIG. 5 ) two or more times and each part of the cable is parallel to each other between the bends. The cable 10 has a free end 11 which can be placed either at the start or the end of the secured perimeter. A further end 12 of the fibre optic cable 10 is connected to a dynamic distributed fibre optic interrogator 13 . A control unit 14 is combining the measurements of all the parts of the cable serpentine 10 and identifying the object 4 on the ground surface 20 . One or more fibre optic cables may be used but each cross-section along the secured perimeter 2 contains at least two fibre optic cables.
FIG. 4 shows a schematic sketch of a perimeter monitoring system with one or more buried fibre optic cables 10 placed in a loop for the situation of FIG. 1 . The loop is place in such a way that both arms of the loop cross each cross-section (see FIG. 5 ) along the secured perimeter. The cable 10 has two ends 12 connected to a dynamic distributed fibre optic interrogator 13 . A control unit 14 is combining the measurements of both arms 10 and identifying the object 4 on the ground surface 20 . One or more fibre optic cables may be placed in such a loop.
If more than one cable 10 is used, then it would also be possible to arrange all cables 10 in loops having the form of the closed perimeter 2 in FIG. 1 , where the free ends of all cables 10 would run parallel to line 3 to the center to close the loop at that place.
For the disclosed perimeter monitoring system it is preferred but not mandatory to use tight buffered fibre optic cables. A tight buffered fibre optic cable 10 is a cable comprising for example a standard commercially single mode fibre with a 9 μm glass core and a 125 μm glass cladding coated by a 250 μm primary buffer connected tight to prevent slippage, around the primary buffer a protection coating comprising for example a 0.9 mm second plastic buffer and a Polyamide protection sheet with outer diameter between 1 mm and 10 mm is placed, alternatively the protection coating can contain a steel armouring built of a thin steel tube placed between the second plastic buffer and the Polyamide protection sheet. It is also possible to use other fibre optic cables 10 which might have less protection around the fibre optic core. Depending on the interrogation technique used to perform distributed strain or displacement measurements along the cable also multimode cables can be used. The main common feature of usable cables 10 is a fibre built from a material which is able to transport light pulses over long distances, e.g. glass.
A dynamic distributed fibre optic interrogator 13 is a commercially available device e.g. from Luna Inc. or Neubrex Co. and its main function is to generate light pulses, to feed them into the fibre core and to detect back scattered light. The expression dynamic denotes a high sample rate of the interrogator and the expression distributed means that measurements are not taken at discrete points on the cable but distributed along the whole cable with one single measurement, comparable to lots of point sensors arranged along a line. With the change in the backscattered light compared to a reference measurement, the interrogator calculates the change in the length of the fibre along the length of the fibre (i.e. strain). A dynamic distributed fibre optic interrogator measures strains along the fibre with high accuracy (˜1 microstrain=1 μm/m), high spatial resolution (˜1-20 millimeter) and high frequency (˜50-1000 Hz). Detailed description of the physical background and the mode of operation of such an interrogator are described in Frogatt et al. 1998 as mentioned in the introduction of the present specification.
The control unit 14 is adapted to receive the signals from the different fibre optic interrogators 13 and combines these into an answer signal of the intrusion detection system according to the following description.
FIG. 5A to 5C show different cross-sections of the shallow trench 15 containing the buried fibre optic cables 10 . The following definitions are used in this context and used as such in the drawings:
h
defines the depth of a cable 10 with respect to the ground surface 20
a
defines the horizontal distance of each cable 10 to one another
h1
depth of the upper buried fibre optic cable(s) 10 with respect to the
ground surface 20
h2
depth of the lower buried fibre optic cable(s) 10 with respect to the
ground surface 20
FIG. 5A now shows three cables 10 , as an example of “two or more” parallel buried fibre optic cables 10 , side by side near the bottom surface 18 of the trench 15 . However it is also possible to provide the cables 10 at a higher position. However, since the major influence on the signal detection as will be shown subsequently is based on the soil portion between the ground surface 20 and the cable 10 , it is preferred to prepare the depth of a trench 15 only to the necessary extent.
FIG. 5B shows two parallel buried fibre optic cables 10 one over the other. Finally, FIG. 3C shows six parallel buried fibre optic cables 10 placed in a matrix configuration 2×3, i.e. two rows of three cables each. The trench 15 then comprises refilled excavated material or soil 17 up to the ground surface 20 .
The embodiments show that further possibilities, not shown in the drawings, are available to obtain the advantages of the invention. It is also possible, to use three heights of cables 10 , i.e. add a further layer in a distance h 3 from ground surface 20 , but the better approach would be to use more cables one beside the other to avoid that someone knowing the placements of the trench jumps or is carried above ground over the entire system.
It is also possible to provide the cables 10 of FIG. 5A at two or three different heights below ground, as long as the depth is predetermined and this predetermined depth can be calibrated to calculate back and identify the type of intrusion. In other words, the time of flight of the light, either backscattered or transmitted, indicate the position of the intrusion. The knowledge of the disposition of the cables at that place along the cable 10 allows deducting the kind of intrusion, i.e. the object identification.
FIG. 6A to 6C show a schematic sketch of the mechanical inverse analysis. The following definitions are used in this context and are used as such in the drawings: FIG. 6A shows an intruding object 21 as an example like object 4 in FIG. 1 entering the perimeter 2 by crossing the buried fiber optic cables 10 . The weight of the intruder 21 on the ground surface 20 and as such on the soil induces contact forces 22 between the intruder 21 and the ground surface 20 . These contact forces 22 induce a stress field in the ground which is in equilibrium with the contact forces acting on the ground surface 20 . Depending on the stiffness of the ground the stress field corresponds to a displacement field of the ground. These displacements are transferred to the cables and yields to a change in the length of the cables. The relative change in the length of the cables, i.e. strain, is measured with a distributed fibre optic interrogator.
FIG. 6B shows the induced strain in two or more fibre optic cables which is measured dynamically with commercially available distributed fibre optic sensing interrogators 13 . Using the measured strain in all the cables 10 allows the detection of an intruder 21 and his localization along the cables 10 . Curve 23 shows the result of a schematic strain measurement conducted in a fibre optic cable 10 near to the object. Further schematic strain measurements as shown in curve 24 are conducted in a different fibre optic cable 10 parallel to the cable 23 further away from the object 21 . The value of the strain is shown against the position on the cable 10 , which is already deducted from time delay measurements of the back scattered light (or the light in a optic fibre ring, then the cable and fibre does not have an open end but forms a ring for delay time measurements).
FIG. 6C shows the contact forces 22 between the object 21 and the ground surface 20 , back-calculated from the measurements along the fibre optic cables 10 .
FIG. 7 shows a schematic procedure of inverse analysis using the data of three strain measurements along parallel buried fibre optic cables 10 in a depth of h=40 centimeters and with a distance to each other of a=50 centimeters, with the meaning of a and h as defined above. Therein, first cable 10 is located directly under the person standing on the ground surface 20 . The strain 33 , 34 and 35 , respectively, along the three cables 10 is calculated with arbitrary contact forces at the ground surface 20 . By minimizing the error between the calculated strains and the measured strains in all the three cables 10 , the position of the contact forces 22 and their magnitude is optimized.
Representative the inverse analysis is shown here for a static point load using an isotropic linear elastic constitutive law to model the soil. Depending on the type of object crossing the perimeter with the buried fibre optic cables more than one load can occur or not only point loads occur.
In the mechanical model arbitrary forces acting on the surface produces the calculated strain 33 , 34 , 35 along the three cables 10 . Depending on the ground conditions the strain along the cables can be calculated using different constitutive laws (e.g. linear isotropic elasticity, Boussinesq (1885); linear cross-anisotropic elasticity; non-linear elasticity, Puzrin and Burland (1996); elasto-plastic constitutive laws). Using the simplest isotropic linear elastic constitutive law, the strains along one cable due to a point load acting at the position x p , y p are calculated by:
ɛ
xx
=
(
x
,
y
c
,
z
c
)
=
P
·
f
(
x
,
x
p
,
y
c
,
y
p
,
z
c
)
with
f
(
x
,
x
p
,
y
c
,
y
p
,
z
c
)
=
1
+
v
2
π
E
·
[
z
c
(
y
~
2
-
2
x
~
2
+
z
c
2
)
R
1
5
+
(
1
-
2
v
)
(
x
~
(
z
c
·
x
R
1
+
2
x
)
)
R
2
2
-
(
1
-
2
v
)
R
2
]
and
R
1
=
x
~
2
+
y
~
2
+
z
c
2
R
2
=
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c
(
R
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+
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)
+
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~
2
+
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~
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x
~
=
x
-
x
p
and
y
~
=
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c
-
y
p
Wherein x is the spatial coordinate along the cable, y c and z c denote the location and the depth of the cable with respect to a predefined reference point at the ground surface. E denotes the youngs-modulus and v denotes the poisson's ratio of the soil.
Now the calculated strains are compared to the measured strains along the cable. The position of the forces and their magnitudes can be back-calculated with different methods, e.g. minimization of the sum of squared error:
min
(
∑
i
=
1
N
(
ɛ
calculated
(
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i
,
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,
x
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,
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measured
(
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The minimization of the sum of squared error can be done with gradient based nonlinear optimization or more sophisticated optimization algorithms (e.g. Levenberg-Marquard, Trust-region-reflective, genetic algorithms, particle swarm optimizers). For the inverse analysis the strain measurements of all buried fibre optic cables are used in order to ensure a distinct and accurate back-calculation of the forces acting on the ground surface.
Since the strain measurements are taken with high temporal resolution, this inverse analysis allows for back-calculating the forces acting on the surface with the same temporal resolution.
FIGS. 8A and 8B show a schematic sketch of the inverse calculated contact force pattern on the surface 20 for a pedestrian 21 crossing the perimeter 2 with three buried fibre optic cables 10 and FIG. 9A to 9C show different strain measurements along three parallel buried fibre optic cables 10 with a pedestrian 21 crossing the perimeter 4 . Therein is defined and shown: FIG. 8A and FIG. 9A show the locations 50 of the contact forces 22 , each point (a, b, c, d, e, or b, d, respectively) corresponds to a footstep, also designated with reference numeral 50 . FIG. 8B and FIG. 9B show the load 60 over time for footsteps 50 at all locations from FIG. 8A or 9A , respectively, wherein in FIG. 9B specific moments in time are chosen as t 1 to t 6 with the respective force values 61 .
FIG. 9C shows measured strains along the three buried cables 10 for the time steps t 1 to t 6 corresponding to the magnitude 60 of the contact force 22 shown in FIG. 9B . Time steps t 1 , t 2 and t 3 correspond to the position of the contact force b and time steps t 4 , t 5 and t 6 correspond to the position of the contact force d.
LIST OF REFERENCE SIGNS
1
Sensitive facility
2
Secured perimeter
3
Feed cable
4
Object, to be identified
5
outside the perimeter
6
inside the perimeter
10
tight buffered fibre optic cable
11
free end of the fibre optic cable
12
further end of the fibre optic cable
13
dynamic distributed fibre optic interrogator
14
control unit
15
trench
16
ground
17
refilled excavated material, soil
18
bottom surface of trench
20
ground surface
21
object moving or standing on the surface
22
contact forces between the object and the ground surface
23
schematic strain measurements in a fibre optic cable near to the
object
24
schematic strain measurements in a fibre optic cable parallel further
away from the object
33
measured strain in first cable
34
measured strain in second cable
35
measured strain in third cable
50
foot step
60
load magnitude over time
61
load magnitude at time t1
111
first cable
112
second cable
113
third cable
133
optimized strain for first cable
134
optimized strain for second cable
135
optimized strain for third cable
a
horizontal distance between two adjacent cables
h
depth of a cable with respect to the ground surface
h1
depth of an upper buried fibre optic cable with respect to the
ground surface
h2
depth of a lower buried fibre optic cable with respect to the
ground surface
t1-t6
time steps
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A fiber optic based intrusion sensing system includes two or more fiber optic cables buried in a shallow trench in the ground, side by side in a predetermined nonzero distance to each other and at one or more predetermined depths. A dynamic distributed fiber optic interrogator measures a predetermined property related to a change in the length of the cables connected to it. A control unit is connected to all interrogators and analyzes the measurements of the predetermined property and identifies objects on the surface by combining the simultaneous measurements of all cables and correlating the measurements to the type of object on the ground surface, the location of the object on the perimeter, the weight, speed and direction of the object, particularly the direction in or out of the secured perimeter.
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BACKGROUND OF THE INVENTION
The invention relates to a method of maintaining a predetermined quality of a carded silver produced in a card and/or drafted in a drawframe, the silver being delivered into a can by a sliver delivery device in a continuous spinning mill process.
The actual spinning machine which produces the yarn end product is of course the costliest machine in the spinning process and is therefore required to operate at maximum efficiency--i.e., to have very short downtimes.
The various machines before and after the spinning machine are therefore so designed performance-wise as to overperform relative to the spinning machine so that the same does not have to wait for the feeding of its feedstock nor for subsequent processing, for example, in a winder.
The overperformance system applies to all the machines involved in the feeding of the feedstock for the spinning machine--i.e., in the blowroom of a spinning mill--viz. as will be described hereinafter with reference to the drawings any machine in the working process has a higher output than the machine immediately following it. This is how the present day machine park in spinning mills has evolved; however, if a blowroom process has to be performed by a machine considerably more expensive than a following machine (excluding the spinning machine), the previous machine may of course have a shorter downtime than the subsequent machine for the sake of economic balance.
These differences in performance can of course be compensated for by buffer stores of product which will vary in size in dependence upon the difference between the performance of the previous stage and the performance of the next stage. Clearly, large buffer stores are undesirable for purely economic reasons and in the course of spinning mill automation systems must be devised throughout from bale opening to end product either to eliminate the known manual intermediate buffer stores or at least so to organize them so that they are automatable.
SUMMARY OF THE INVENTION
The problem which the inventor had to address was therefore to optimize the performance steps in a spinning mill blowroom to minimise the size of the buffer stores for intermediates and to facilitate automation.
To solve the problem, according to the invention, the card and/or drawframe, which each have a predetermined overproduction relative to a spinning machine associated with the process, have a predetermined temporary decrease in production which temporarily compensates correspondingly for the overproduction.
Also suggested for performing the method is a drawframe wherein the drawframe control has a computer part which at the changeover to decreased production effects the programmed slowdown and, if applicable, the stoppage and at the changeover from decreased production effects the programmed acceleration preceded, if applicable, by restarting.
Also suggested for performing the method is a combined card and drawframe system wherein the drawframe system has a supply of cans and, disposed in such supply, a can row with a can counter and the same responds to the presence of predetermined number of cans in the row by outputting a signal.
The advantage of the invention is that it offers a basis for optimising profitability and a possibility for automation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail hereinafter with reference to embodiments.
In the drawings:
FIG. 1 is a diagram showing the efficiency of various items of spinning mill machinery;
FIG. 2 is an illustration in graph form of the method steps according to the invention;
FIG. 3 shows a variant of FIG. 2;
FIG. 4 is a diagrammatic view of a card having a silver delivery device, the view being in cross-section;
FIG. 5 is a diagrammatic plan view of the card of FIG. 4;
FIG. 6 is a diagrammatic plan view of a combined card and drawframe system, and
FIGS. 7 and 8 are each a view to an enlarged scale of a detail of the system shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an efficiency diagram of a number of spinning mill machines in which total efficiency is represented by a chain-dotted line W and the downtimes of the various machines are illustrated (in purely diagrammatic form) by means of spacer arrows DP, DK, DST, DF, DR and DSP.
The letters in the hatched rectangles have the following meanings:
The letter P denotes blowroom machines
The letter K denotes cards
The letter ST denotes drawframes
The letter F denotes roving frames
The letter R denotes ring spinning machines
The letter SP denotes winders
The rectangles containing the letters P to SP are purely diagrammatic representations of machine performaces or outputs, their areas being such that the area of any machine type is less than the area of the immediately previous type except for the area representing the winders, which is greater than the area representing the ring spinning machines. The aim of the diagram is to visualize the decrease in output as seen from the blowroom machines up to and including the ring spinning machine, the differences between the areas being exaggerated so that the differences can be more clearly visualized: Also, the areas shown are not in their actual relation to downtime and the latter too is shown for the sake of clarification with greater differences than are usually found in practice.
Correspondingly, in the co-ordinate system shown in FIGS. 2 and 3, efficiency is plotted along the ordinate and the steps of the method along the abscissa. As previously stated, the steps of the method are:
Blowroom=P
Card room=K
Drawframe=ST
Roving frame=F
Ring spinning machine=R
Winding room=SP
Of the machine types P to F the card is the most complex--i.e., a machine in which a large number of technical and technological functions must co-operate if a uniform and high-quality card sliver is to be produced.
Consequently, the co-operation between the various functions does not of course lead to absolutely the same result as regards sliver quality in all the performance steps and the same assumption is made further on in the production process--i.e., in drafting and in the roving frame--so that is may be necessary to separate out the carded sliver in the event of substantial output changes.
In the method according to the invention, to link this elimination of a sliver which cannot be used in the subsequent stages with can changing in the card, when it is required to decrease card output, the card continues to produce at its normal output until can changing becomes necessary, the card being changed over to decreased output shortly after can changing, either until stoppage of the card or until further production at a minimum output step.
The decrease in production occurs with a slowdown of the kind represented by a line 1 in FIG. 2, where the card is brought to a standstill, then restored after a controlled time T to full output represented by lines 2a, 2b, a line 3 representing this acceleration.
Chain-dotted lines 4, 5 indicate the activation times for can changing, the line 4 denoting the activation time before the slowdown 1 while the line 5 denotes the changeover time for further can changing after the acceleration 3, whereafter the sliver produced on full output is delivered into the next can.
Consequently, no sliver produced on decreased output can be delivered into a "good" can intended to receive only sliver which has been produced on full output.
FIG. 3 shows the same principle except that output is not reduced to zero as it is in FIG. 2; instead the card continues to produce at a very low output, for example, 10% of normal output until the control instruction for acceleration back to normal output is given.
The advantage of the method shown in FIG. 3 is that cards which cannot be completely guaranteed to produce breakage-free sliver until the card stops can continue to produce on low output without a large quantity of waste sliver accumulating. The decrease in production shown in FIG. 3 is represented by a line 6. Since the other lines relate to functions substantially corresponding to the functions of FIG. 2, the latter lines have the index 1 added to their references.
FIG. 4 is a view in cross-section of a known card 10 having a known sliver delivery device 11 and, disposed between the same and the card 10, a known sliver loop sensor 12.
The card 10 is a card produced by the Applicants and sold world-wide as type C4/C1 and the facility comprising the elements 11, 12 is sold by the Applicants world-wide as type CBA.
The two combined machines were presented to the public, for example, at the 1989 American Textile Machinery Exhibition (ATME) in Greenville.
The card 10 and the device 11 operate through the agency of a control 13 which triggers the card with the necessary output-controlling signals and which imposes on the delivery device 11 a sliver delivery corresponding to card output, sliver delivery being adapted by means of the sliver loop control 12 to the alteration in card output in dependence upon the alteration thereof.
Sliver output--i.e., the weight of sliver produced per unit of time--is measured by means of a measuring roller pair 14 at the card exit and communicated by means of a measuring signal 15 to the control 13. The same deduces from the signal 15 an output-controlling signal 16 which controls the motor 17 driving the delivery device 11.
Alterations in sliver delivery after the roller pair 14 are recorded by the sensor 12 and communicated by means of a signal 18 to the control 13 so that by means of the signal 16 the motor 17 has its speed varied in accordance with the change in output.
A novel feature provided by the invention is that the control 13 has a computer attachment which is indicated in purely diagrammatic form by the reference 19 and which responds to the operation of a switch to be described hereinafter by decreasing card output in accordance with either FIG. 2 or FIG. 3, further operation of the same switch accelerating the card in the manner shown in FIGS. 2 and 3.
The decrease in output and the acceleration cause a change in the position of loop 20 of the sliver 21 which the card 10 produces and which the device 11 delivers into a can 22. This change in the position of the loop 20 produces corresponding signals 18 so that the delivery device 11--i.e., motor 17 thereof--either slows down or accelerates the device 11 correspondingly. This feature provides the advantage that no additional synchronization between the card motors and the motor 17 driving the device 11 is required.
FIG. 5 is a plan view of the card 10 and delivery device 11 and also shows the sliver loop sensor 12.
Like elements in FIGS. 4 and 5 have the same references.
As previously stated, the device 11 is known from the publication. A novel feature provided by the invention is that the entering empty cans are conveyed by a conveyor belt 23 as far as an exit position M in which a displacing arm 24 of can displacer 25 moves the can into sliver delivery position N in which sliver is introduced into the can.
The can which has been filled with good sliver is moved by a second displacing arm 26 into a first removal position T on a conveyor belt 27 while a can which has been filled with a low-output sliver is moved into a second removal position Q on a conveyor belt 28. The computer part 19 controls these operations.
The arms 24, 26 can so pivot (not shown) as to be pivoted from a vertical position, in which they can be moved past the stationary cans, into a horizontal position in which they can displace the cans. The arms 24, 26 are parts of the delivery device 11.
The significance of the conveyor belts 23, 27, 28 will be described in greater detail with reference to FIG. 6.
FIG. 6 shows a number of cards 12 so disposed parallel to and adjacent one another that the conveyor belts 23, 27, 28 extend to a can conveyor 29. The cans on the conveyor belts are moved in directions indicated by arrows in FIGS. 5 and 6--i.e., the cans on the belt 23 are moved towards the can delivery and the cans on belts 27, 28 are moved towards the can conveyor 29. The cans on the belt 23 are empty cans, the cans on the belt 27 are full cans and the cans on the belt 28 are cans containing the sliver produced with the card on decreased output so that a can may have any level of filling.
So that the cans can either be pushed off the conveyor 29 on to the belt 23 or pulled off the belts 27, 28 on to the conveyor 29, the conveyor 29 has pneumatic reciprocating actuators 30, the operation of which is shown in greater detail in FIG. 8. As can be gathered therefrom, the actuators comprise a suction and shifting shoe 31 adapted to the diameter of the cans 22 and having an air-permeable but plastically deformable wall 32 which is adapted to can diameter and which covers a hollow member 33 associated with a bore 34 extending through piston rod 35 and piston 36, so that cavity 37 communicates with pressure chamber 38 of cylinder 39.
At its end near the delivery chamber, the bore 34 has a check flap 40; when the chamber 38 is maintained at a positive pressure by way of a compressed air valve 41 connected to the chamber 38, the flap 40 closes the bore 34 so that the piston 36 and, therefore, the shoe 31 can move in the direction indicated by an arrow 42.
When, however, a suction valve 43, which is also connected to the chamber 38, is open instead of the compressed air valve 41, the chamber 38 is at a negative pressure, so that the flap 40 opens and the cavity 37 is at a negative pressure. The negative pressure sucks tightly on to wall 32 of a can 22 in contact therewith which is also displaced together with the shoe 31 in the direction indicated by an arrow 44 until the hollow member 33 contacts an abutment 90 limiting this movement in the direction 44.
Sensors detecting the position of the shoe 31 for the valves 41, 43 to be changed over by means of a control (not shown) are not shown here.
The suction valve 43 is connected to a suction source 45 and the compressed air valve 41 to a compressed air source 46.
By means of a pneumatic reciprocating actuator 30, empty cans are pushed off the can conveyor 29 on to the conveyor belt 23 and full cans are pushed off the conveyor belt 27 on to the conveyor 29; the cans are also pushed off the belt 28 on to the conveyor 29.
The can conveyor 29 is movable on rails 47. A control station controlling movement of the can conveyor 29 is illustrated diagrammatically in the form of a rectangle having the reference 48; it is the subject of the Applicants' patent application No. CH 0 4410/88-1 and is not further described here.
A drawframe 50 is contiguous with the rails 47 and is disposed on a side remote from the cards of the rail oval shown in FIG. 6; the drawframe 50 takes over the cans filled by the cards 12 and processes their silver. A drawframe of this kind is known and, for example, sold by the Applicants world-wide under the designation D1.
The drawframe includes the actual drafting unit 51 which drafts slivers 53 infed on a feed table 52.
The slivers 53 are delivered from can row 54 in which emptying cans are disposed. Can row 55, which extends parallel to row 54, consists of full cans in a reserve position. Can row 56 which is parallel to and in FIG. 6 immediately above row 55 is another full-can row but a row adapted to take up full cans from the conveyor 29.
On the bottom side of the feed table 52, looking at FIG. 6, a row of empty cans 57 stands ready parallel to the feed table 52 for transfer to the can conveyor 29.
This can arrangement just described is shown more clearly and to an enlarged scale in FIG. 7. As will be apparent, the cans of row 56 can be moved both in the conveying direction 58 and in the conveying direction 59, movement in the direction 58 being produced by discrete conveyor belts 60 disposed in adjacent end-to-end relationship to one another whereas the cans 52 can be moved in the direction 59 by reciprocating actuators 30. The same move the cans 22 from row 56 to row 55. Conveyor belts 60 are provided to move the cans 22 in the rows 55, 54 but are at a 90° offset in their conveying direction from the conveyor belts of the row 56 so that the cans are moved in the direction 59.
The cans emptied in the row 54 are moved through below the feed table 52 by means of another row of conveyor belts which move the cans so far in the direction 59 that the cans can be drawn by further actuators 30 on to the conveyor belts of the row 57. The cans move in the direction 61 on the latter belts for conveyance towards the can conveyor 29. Instead of the discrete conveyor belts of the row 57 shown in FIG. 7, a single conveyor belt (not shown) can be used.
Cans are displaced into the next row--i.e., e.g., from row 56 into row 55 and so on--when the cans in row 54 are empty, a state which is detected by a sliver sensor (not shown) on the feed table 52, for example, at the deflections 91 which deflect the sliver through 90°, and which is fed into a control 63 as a signal 92 (not completely shown). The control 63 initiates activation of whichever conveyor belts and reciprocating actuators move the cans in the direction 59--i.e., the conveyor belts 55, 54, 62 and the actuators 30 for both pushing and pulling the cans.
The control 63 is also responsible for moving the cans in the drawframe 50 in good time--i.e., changing full cans for empty cans--something which is performed in basically the same way as described with reference to the cards 12 and indicated by corresponding arrowed directions. The actual drafting unit 51 of the drawframe 50 is controlled by means of an associated computer part for both stop-start operation and low-output operation.
A can conveyor 29.1 is provided for the drawframe 50 in just the same way as for the cards 12 and has the same function as the conveyor 29 but it conveys the full and empty cans to a machine which follows the drawframe, such as one or more roving frames.
The cans previously described which contain sliver produced during low-output operation of the cards 12 and which are supplied with the silver 28 to the can conveyor 29 are delivered thereby to a standby row 70 in which the cans are conveyed on a conveyor belt in a direction 71 so that they can be received by further means (not shown) and conveyed to a clearing station (not shown), whence empty cans return and are introduced into a standby row 72 also in the form of a conveyor belt so operated that the empty cans can be conveyed in a direction 73 towards the can conveyor 29 and delivered thereto.
The can-displacing arrangement for the drawframe 50 corresponds basically to the arrangment described for the cards 12 and so will not be described and illustrated again. Similar considerations apply to the standby position of the full and empty cans containing sliver of below normal quality so that this sliver is cleared in the clearing station.
Basically, however, output can be controlled down to zero with the drawframe 50 without any loss of quality in the drafted sliver so that the conveyor belt and the corresponding function associated with reception of the cans, similarly to the cans on the belt 28, can be omitted.
Finally, the row 56 has a can detector which by means of a signal 80 informs station 48 of the number of cans present in the row.
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The present invention is directed to a method of maintaining a predetermined quality of a carded sliver, wherein there is a predetermined overproduction from a card and/or a drawframe relative to a spinning machine. The method includes temporarily decreasing production to temporarily compensate for the overproductions. The sliver which is produced during the decrease in production may be delivered to a separate can.
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FIELD OF THE INVENTION
The invention relates to Bank Owned Life Insurance (BOLI) and a system for designing and administering a BOLI plan for financial organizations (herein referred to as the BOLI system). The BOLI system provides a single comprehensive and integrated computer system and computer program incorporating all the necessary requirements for ensuring the BOLI plan meets the financial needs of the bank in accordance with substantive and complex legal regulatory guidelines. Examples of the type of functionality offered by the BOLI system includes the capability of determining premiums, deriving the insurable interest for a particular state, monitoring reinsurance, tracking and reporting on the performance of the reinsurance plan, and performing necessary administrative procedures.
BACKGROUND OF THE ART
Employee benefits, such as medical, group life, dental, disability and other ERISA welfare plan expenses, are a significant element in a financial organization's compensation programs. The expenses associated with these benefits comprise from 20 to 30 percent of all compensation expenses. This is a meaningful number for financial institutions, especially for a national bank. In general, total compensation is a national bank's second largest expense. In addition, recent studies have suggested that benefit plan expenses will continue to increase at a rate that is far in excess of the rate of increase of a bank's interest income.
Thus, the careful management of compensation expenses can have a pronounced impact on net income for a bank. The banks, however, are severely limited in the methods by which they can manage these compensation expenses, especially those methods which involve increasing revenue to offset rising employee benefit expenses.
One tool available for financing employee benefit expenses is Bank Owned Life Insurance ("BOLI"). BOLI plans or their equivalents can be implemented for a number of financial organizations which are subject to similar financial and legal constraints. The traditional market for a BOLI plan, however, are national banks.
Under a BOLI plan, a bank purchases insurance on a group of employees. The group can be all full time employees or a group of managers, e.g., Assistant Vice Presidents and above. The bank pays the premium(s) and owns the cash value of the polices. The bank is also the beneficiary of the insurance. The employees may or may not receive any of the insurance benefits directly depending upon the discretion of the financial organization. The coverage does not replace or interfere with any other insurance provided by the bank, e.g., group term life insurance and so forth.
The bank earns income from the policies from two sources. The first is from the growth of the cash value of the policy. The cash value is the monetary value of the policy if surrendered. It is also the value which is counted as an asset by the bank. The cash value increases each year as interest is added by the insurance company. The second source of income comes from the insurance proceeds paid to the bank when an employee dies. The payment of insurance proceeds and the earnings from the cash value are income tax-free (unless surrendered).
The reasons banks use BOLI to offset employee benefit costs are two-fold. First, BOLI earns a greater after-tax yield than many bank investments. Therefore, a favorable spread is created. This spread is greater than what a bank earns on other investments, e.g., Treasury Bills, corporate bonds, etc. Second, BOLI is a long-term investment which corresponds to the long-term nature of benefit plan expenses.
The policies the bank buys are investment-oriented and produce income for the bank in the first year they are purchased. The after-tax income they earn is higher than what the bank earns on many alternative investments. This explains the growing popularity of BOLI as demonstrated by the industry wide increase in BOLI investments from $500,000 in the 1980's to over an estimated $5,500,000,000 in 1995.
There are two guidelines which determine the amount of coverage a bank could purchase on employees. The first is governed by the State's Insurable Interest Guidelines which varies from state to state. The second is regulated through guidelines established by the Office of the Comptroller of the Currency (the "OCC"). The guidelines which are of particular importance to BOLI plans are found in OCC Banking Circular 9651 (the "Circular").
The OCC provides federal regulatory oversight for a national bank's purchase of life insurance policies. The Circular provides general guidelines for national banks to use in determining whether they may purchase a particular life insurance product. Under the Circular, a national bank may purchase life insurance only for a purpose incidental to the business of banking, and not as an investment.
A bank may also take an interest in life insurance policies as security for loans. The Circular confirms that life insurance death benefits and cash surrender values are unsecured assets of the bank. The cash surrender value of insurance should be reported as an "Other Asset" on the bank's financial statement.
BOLI appeals to the banking industry because it is marketed as a high-return, low-risk, long-term asset. The "high return" is premised in part on the fact that BOLI policies' earnings are not taxed either currently or when their death proceeds are paid, and in part on the expectation that the insurers issuing the policies offer and will continue to offer a greater yield on the policies than purchasing banks could obtain with other assets. Intermediary companies arrange the placement of BOLI coverage issued by unrelated life insurance companies that are typically AAA, AA+ or AA rated by Standard and Poors, in an effort to minimize risk for the purchasing banks. In placing BOLI coverage, the intermediary company performs actuarial calculations to determine the amount of life insurance that the bank may purchase in accordance with Banking Circular 9651, thus designing a plan to meet the particular bank's needs, and administering the plan.
The problems associated with constructing a BOLI plan to fulfill the needs of a particular financial organization are considerable. Specifically, there are problems associated with determining BOLI plan limits imposed by federal and state regulatory guidelines. In many cases, the numerous factors involved in determining these limits for even a medium size bank could lead to hundreds of thousands of different permutations. The sheer volume of variables make such a calculation nearly impossible to generate by hand, especially given the yearly review and reporting requirements of these regulatory guidelines.
Another problem associated with implementing the BOLI plan is the bank's need for complicated financial data such as Earnings Per Share, Return on Asset, Return on Equity, Net Income, and a host of other categories. The bank uses this information for accounting and strategic planning purposes.
Yet another problem is the size and sheer volume of administrative functions associated with the ongoing management of the BOLI plan. These administrative functions make the BOLI plan a difficult and cumbersome plan to implement in accordance with the numerous financial considerations and legal requirements.
Aside from the management and administrative problems associated with designing and implementing a BOLI plan, the traditional BOLI plan has inherent drawbacks which makes it unattractive to the banking industry. In particular, banks are not comfortable making a large premium payment to a carrier that would go into the general account or portfolio of the carrier. If the carrier has a credit difficulty or an impediment to making payments the bank becomes the general creditor of the carrier. Thus there is a problem with maintaining control over the banks' transferred assets. Further, given the long-term nature of the plan, banks were concerned with the long-term credit worthiness of the insurance carriers and the delay in cash flow (since it is predicated on the death of an employee). Another problem with traditional BOLI products is that banks can only lend 15% of shareholder equity to a single entity, and only 25% total of a bank's shareholder equity can be used for life insurance. Thus, if a favored carrier of the bank has existing insurance products, the premium amount the bank could pay to the carrier would be limited. Finally, the plan fails to provide an after-tax interest gain exceeding straightforward and vastly less complicated investments such as Treasury Bills.
The aforementioned problems, coupled with the significant administrative burden in executing the plan and the long-term nature of the plan, removes BOLI as an attractive investment opportunity for banks. This comes at a time when competition with non-bank entities is projected to lower the profit margins for most banks over the next few years, while costs associated with employee benefits are predicted to rise, thus forcing banks to rely more heavily on investments as a means of maintaining financial health. This makes the removal of BOLI as a profitable investment vehicle particularly onerous given the relatively few number of investment options left open to the banks due to federal and state regulations.
Beyond some simple spread sheet programs which are currently used to ensure compliance with the Circular, relatively little attention has been paid to computer hardware and computer software systems for handling the problems associated with the BOLI plan to minimize actuarial, management and accounting time and costs. Even more critically, no computer software and/or computer hardware system has been developed to correct the deficiencies inherent in traditional BOLI plans by providing a system capable of managing and controlling the reinsurance of the BOLI plans.
In fact, prior systems are solely directed towards monitoring current BOLI plans to ensure governmental compliance. Those systems have thus not integrated all phases of a BOLI plan, especially those involving a reinsurance option. In sum, there does not appear to be a computer software, hardware system available for designing, implementing and monitoring BOLI plan parameters in an efficient integrated system.
SUMMARY OF THE INVENTION
It is thus apparent from the above that there exists a significant need in the art for a system which enables a company to effectively and efficiently design and administer a BOLI plan to offset employee benefit expenses while providing the company with the analytical and management capabilities for controlling a BOLI plan with a reinsurance option.
It is therefore one of the objectives of this invention to provide a system for designing and implementing a BOLI plan for national banks in conformance with legal regulatory requirements.
Another object of this invention is to provide a system for implementing a BOLI plan for banks with reinsurance of the BOLI plan by a captive insurance company of the bank in conformance with legal regulatory requirements.
Another object of this invention is to provide a system for effectively and efficiently generating the highest amount of BOLI premiums a bank may purchase within the guidelines set forth in the Circular.
Another object of this invention is to provide a system for calculating the insurable interest for a given State's insurable interest requirements.
Another object of this invention is to provide a system which automatically produces complicated financial data by category with respect to the BOLI plan such as Earnings Per Share, Return on Asset, Return on Equity, Net Income, Net Interest Margin, Capital Ratios and a host of others.
Yet another object of this invention is to provide a system for evaluating statutory restrictions of reinsurance policies and risk assumption, and ensure compliance with applicable legal regulations.
It is a further object of this invention to provide a system for modeling reinsurance company financials to measure impact on surplus and to test for life company tax status.
It is yet another object of this invention to provide a system for ceding business from an insurance company to a reinsurance company which includes the transfer of risk, assets and liabilities, as well as calculating ceding fees, cash flow and in force calculations and mortality risks.
Another object of this invention is to provide a system for calculating investment income and expenses charged in order to determine net income or loss.
It is still another object of this invention to provide a system for adjusting reserve requirements to send to the trust company.
Another object of this invention is to provide a system for recording by the reinsurance company BOLI plan reinsurance profit or loss.
It is a further object of this invention to provide a system for a computer support system which verifies, reconciles, consolidates and reports policy values for the client bank, including summary detail of all accounting entries, premium values report, beneficiary report, current and projected cash surrender value report, census reconciliation report, comprehensive listing of policy information report, cash flow report, net policy face value report, profit/loss report, and plan liquidity report.
Another object of this invention is to provide a system for performing administrative procedures such as the periodic sweep of social security records to identity and initiate death claims for covered employees who have terminated or retired, periodic employee status updates to identity terminated or retired employees covered in the plan, and alternative policy settlement options.
Briefly described, these and other objectives of the invention are accomplished by providing a system which smoothly integrates the following functions into an integrated computer-based system for designing and administering a BOLI plan for national banks under current federal and state guidelines and financial market constraints, including such means as for determining the highest BOLI premium permitted under OCC Banking Circular 9651. The system determines insurable interest requirements by accessing a database with the appropriate state's insurable interest guidelines, generating performance estimates for the BOLI plan, allocating premium amount by business unit and employee and ensuring that the BOLI plan is in compliance with the regulatory requirements for the business unit. The systems also reinsures the BOLI plan through a captive insurance company of the financial organization. Other functions performed by the system include obtaining policy values for the captive insurance company, verifying, reconciling, consolidating and reporting policy values for the financial organization, and performing administrative procedures for the BOLI plan of the financial organization.
With these and other objectives, advantages and features of the invention that may become apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims, and to the several drawings attached herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block flow diagram showing the life insurance organization according to a preferred embodiment of the present invention;
FIG. 2 is a block flow diagram of the analytical system for determining parameters for the life insurance organization according to FIG. 1;
FIG. 3 is a block flow diagram of the analytical system for calculating BOLI plan limits per the Circular;
FIG. 4 is a block flow diagram of the analytical system for calculating a State's insurable interest;
FIG. 5 is a block flow diagram of the analytical system for sizing the BOLI transaction and generating performance estimates for the BOLI plan;
FIG. 6 is a block flow diagram of the analytical system for completing allocation of the BOLI plan premium amount by business unit and employee; and a block flow diagram of the analytical system for implementing the BOLI plan;
FIG. 7 is a block flow diagram of the analytical system for reinsuring the BOLI plan; and
FIG. 8 is a block flow diagram for obtaining policy values and a listing of information required to obtain such policy values; a block flow diagram showing the reports generated by the system; and a block flow diagram showing the administrative procedures performed by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, there is illustrated in FIG. 1 a block-flow diagram of the BOLI plan life insurance organization 110 according to a preferred embodiment of the present invention. The financial institution which will be used in the preferred embodiment is a national bank.
One of the purposes of the life insurance organization 110 is to implement a BOLI plan as an asset which mitigates balance sheet recognition of the indirect cost portion of employee benefits liability, while also generating earnings sufficient to cover the cost of the employee benefits. The life insurance organization, as implemented in FIG. 1, also provides an ongoing administrative computer-based system to enable corporations to manage the BOLI plan efficiently and in full compliance with federal and state regulatory guidelines.
Under a BOLI plan, a purchasing bank 100 of a parent bank and/or Holding Company 101 sells Treasury Bills or other assets to provide cash to purchase individual, single premium life insurance policies covering the lives of a group of its employees. The bank 100 enters into a BOLI plan binder agreement and/or insurance contracts 102 which sets forth the details of the insurance policy between the bank and the insurance company 106. The bank 100 pays the premiums 104 to the insurance company 106 and owns the cash value and death benefits 122 of the policies. The bank is the beneficiary of the insurance and holds the policies' values as its general assets. The employees may or may not receive any of the insurance benefits directly depending upon the discretion of the financial organization. The coverage does not replace or interfere with any other insurance provided by the bank, e.g., group term life insurance and so forth. The earnings from the cash surrender values and death benefits from the policies are expected to offset a substantial portion of the bank's expenditures under its employee benefit plans.
The insurance company 106 in turn reinsures the BOLI plan of the bank 100 with a reinsurance company 118 which is a captive insurance subsidiary of the parent bank or holding company 101. The reinsurance can be implemented using a number of different systems such as assumptive reinsurance or mortality reinsurance. In the preferred embodiment, the quota shared method of reinsurance is used. This method passes a certain percentage of the premium dollars, risk and liabilities 116 to the reinsurance company 118 in exchange for the assumption of the equivalent percentage of investment performance, death benefits, premium tax and commissions 120 associated with the BOLI plan. The relationship between the insurance company 106 and reinsurance company 118 is defined by the reinsurance treaty 112. The surplus drain and required reserves of the transaction is held in a trust company controlled by the custodial trust agreement and/or letter of credit 114.
Referring now to FIG. 2, flow chart 125 illustrates the front-end analytical system used by a computer system for implementing the BOLI plan. The computer system operates the BOLI system programs shown in FIG. 1. The analytical system consists of computer hardware and software. The computer hardware comprises a personal microcomputer that has the capacity for rapidly developing value estimates based on the software. Although many types of computers may be used, the present invention contemplates a computer system using at least an 80-386 based microprocessor and at least a 40 MB hard drive capacity and at least 1 MB of RAM.
FIG. 2 also shows a HRIS computer interface 130 which interfaces with the Human Resources Information System (the "HRIS") to pull data on the employees which is used to calculate the eligible employee benefit plan expenses and contributions. This information is passed to the Circular limits generator 150 which determines BOLI plan limits in conformance with the Circular. Once the federal plan limits are established, the insurable interest generator 170 calculates the insurable interest limit (i.e., amount of death benefits) allowed for each employee as per the guidelines for the State where the BOLI transaction has legal residence.
Once the system establishes these limits, the pro forma module 190 generates performance estimates for the BOLI plan. The premium allocatur 210 then calculates the regulatory requirements for each business unit involved in the life insurance organization 110 by employee and ensures that the BOLI plan is in compliance with such requirements. Once the BOLI plan has been fully designed for the bank 100, the BOLI plan installer 230 initiates the process for implementing the BOLI plan.
The reinsurance module 250 controls the reinsurance of the BOLI plan by the reinsurance company 118. The fronting company interface 270 gathers information from both the insurance company and reinsurance company to obtain policy values. The client reporting subsystem 290 verifies, reconciles, consolidates and reports the policy values for the bank 100. The administrative support subsystem 310 performs administrative procedures relating to the BOLI plan.
FIG. 3 is a block flow diagram of the analytical system for determining BOLI plan limits in accordance with the Circular. Under the Circular, a national bank may purchase life insurance only for a purpose incidental to the business of banking, and not as an investment. A life insurance policy is considered to be purchased and held for non-investment purposes if it satisfies either of two tests.
Test A applies if a bank purchases life insurance to indemnify itself against the death of an individual, i.e., key-person insurance. The amount of insurance coverage must closely approximate the risk of loss. The OCC considers the amount of insurance to be the total death benefit to be received upon the death of the insured. This includes the face amount of the policy, and premium to be returned, and accrued interest and/or dividends.
Under Test A, a bank can purchase life insurance to protect itself against the loss of key employees. Generally, a bank may purchase life insurance on the life of any officer or director of the bank whose death would be sufficiently significant to the bank as to create an insurable interest in his or her life.
The banks' board of directors is required to document the basis for determining which employees are key persons and the amount of insurance needed to indemnify the bank against the death of such persons. The bank may not purchase life insurance for an employee who cannot be demonstrated to be key to its business nor can the bank purchase an amount in excess of its potential loss.
The Circular also states that the bank's authority to hold life insurance on key employees terminates if the employee ceases to be a key person due to retirement, discharge, or some other event. Therefore, the economic effect of terminating or transferring life insurance policies must be evaluated carefully on an individual basis under Test A.
This provision of the Circular also allows a bank to purchase life insurance on the life of borrowers under certain circumstances and depending on applicable state law. Such policies must comply with the restrictions discussed above and may not be used by a bank as a method to recover obligations that have been or are expected to be written off.
Test B, which is used in a preferred embodiment of the present invention, applies when the bank purchases life insurance in conjunction with providing certain employee compensation or benefits, or when the insurance constitutes all or part of the benefit. Then, based upon reasonable actuarial benefit and financial assumptions, the present value of the projected cash flow from the policy must not substantially exceed the present value of the projected cost of the associated compensation or benefit program liabilities. The bank may include the insurance premiums paid and the associated time value of money in its calculation of the total cost of the liabilities.
Banks, including National banks, are afforded discretion in establishing compensation levels and benefit plans, though these banks are responsible to justify both. The Circular confirms that life insurance is a legally viable means for a bank to finance such obligations. Benefit plans discussed in the Circular include traditional employee benefits and direct fee deferral programs, but not estate management programs for key employees except as part of reasonable compensation. Life insurance purchased in connection with compensation agreements and benefit plans may be held for so long as the bank has a continuing liability under such agreements or plans. The OCC National Office staff confirms that calculations under Test B may be performed on an aggregate or group basis, that is, a particular policy need not be identified to finance a particular employee's benefit.
Thus, as shown in FIG. 3, employee census data 151, bank benefit plan expenses/contributions data 152, bank compensation plan information 153, life insurance company data such as mortality, cash value, cost of insurance, expenses and death proceeds 154, and bank balance sheet data 155, are inputted into the system. This information is derived from the HRIS interface 130 which interfaces with the HRIS system of the bank 100. Data 152 and data 153 are used to estimate the annual inflation factor, annual discount factor and bank tax rate 156 used by the circular limit module 150. Data 151 and data 156 are used to calculate the present value of the projected after tax cost of employee benefit plan expenses/contributions on a year-by-year basis and sum projected expenses and contributions for all eligible benefit plans 157. Data 154 and data 156 are used to calculate the present value of the projected cost of the BOLI policies on a year-by-year basis as based on actuarial estimates 158. The information generated by step 157 and 158 is used to calculate the sums of projected expenses and contributions for all eligible benefit plans and projected BOLI policies cost based on actuarial estimates 159.
Further shown in FIG. 3 is that bank balance sheet data 155 is used to determine target BOLI premium 160. To derive the target BOLI premium an asset and liability analysis is performed on the banks' balance sheet. The assets and liabilities analysis provides information to the assets and liability committee ("ALCO") of the bank.
Thus, the target BOLI premium 160 uses a software program ("ALCO program") which evaluates and compares the assets and liabilities of the bank to determine the advantages and disadvantages associated with the BOLI plan. The program also provides accounting characteristics of the BOLI plan and forecasts the performance of the plan.
The ALCO program uses the Monte Carlo method for its analysis. The program generates random scenarios and using those scenarios develops a probability curve showing the risk and rewards of the transaction. The bank's financial situation is compared to the probability curve in order to identify and eliminate as much risk from their assets and liability measurement as possible. In particular, the bank weighs various risk factors such as interest rate risks and credit risks and attempts to protect itself from interest rate swings or credit risk from the carrier. Thus, by using the probability curve and comparing the bank's financial situation to this curve to identify and minimize the risks associated with the transaction, a final premium amount for the BOLI plan is identified.
__________________________________________________________________________ Insurable InsurableState Interest Consent State Interest Consent__________________________________________________________________________Alabama st wr Montana st wrAlaska st wr Nebraska st crArizona md cr Nevada st wrArkansas md wr New Hampshire clCalifornia md wr New Jersey mdColorado cl New Mexico st wrConnecticut cl New York st wrDelaware md wr North Carolina mdDistrict of Col. cl North Dakota stFlorida cl cr Ohio clGeorgia md pc Oklahoma me wrHawaii st wr Oregon st wrIdaho st wr Pennsylvania st noIllinois me ng Puerto Rico clIndiana st Rhode Island clIowa cl South Carolina clKansas me ng South Dakota st wrKentucky ** ** Tennessee clLouisiana st wr Texas st wrMaine me wr Utah st wrMaryland me wr Vermont clMassachusetts nr wr Virginia me ntMichigan me cr Washington st wrMinnesota md wr West Virginia st crMississippi cl Wisconsin st wrMissouri me ng Wyoming st wr__________________________________________________________________________ Key cl common law or case law statement of insurable interest st statutory statement of insurable interest without explicit statement that an employer has such an interest md statutory statement of insurable interest with statement that employer has such an interest in nonkey employees me statutory statement of insurable interest with statement that employer has such an interest and instruction as to measuring the value of the interest nr insurable interest not required cr consent required wr written "positive" consent required ng "negative" consent allowed nt notice only required no consent not required pc public corporations with insurable interest may insure without consent others require written consent ** Kentucky appears to be inhospitable to COLI since a corporation may only insure employees if the benefit is payable to a pension or benefit plan
The goal of ALCO management is to match the bank's assets which would be invested in the BOLI plan against their liabilities which include the bank deposits. The bank wants to avoid the situation where the pricing of their deposits have a certain time duration associated with them. If those deposits shift or move away from the bank the bank must buy down their asset to balance this out. If the bank takes a wrong position on a product like BOLI, and fund it with short-term assets, they end up with disintermediation, which is the net outflow of capital from a bank or from a depository institution.
Thus, the bank is matching the probability of a 1% rise up or down in interest differentials and measuring the impact of that to the transaction. This is referred to as duration analysis, which is one of the analytical tools that banks use in their ALCO management. The program frames a transaction and the risk environment of the transaction given the deposit base of the bank or other liabilities for the banker.
A pro forma is then done for the bank based on this information. The pro forma states the profit potential for the BOLI plan. The bank uses the pro forma to decide whether it should engage in the BOLI transaction. If the bank can earn more with an alternative investment, that has comparable or reduced risk profile, it will forego purchasing the BOLI plan.
Once the target BOLI premium 160 is calculated, it is combined with data 156 and data 154 to calculate the present value of projected life insurance proceeds based on targeted BOLI premium amounts 161. The figure generated from present value costs 159 and present value proceeds 161 are compared. If present value proceeds 161 exceeds that of present value costs 159, the Circular limits generator 150 solves for the highest BOLI premium amount that does not exceed the present value costs 159.
FIG. 4 shows a block flow diagram for calculating a State's insurable interest. The insurable interest generator 170 calculates the insurable interest the bank 100 has in it employees as defined in the pertinent state statutes. Table 1 shows a listing of legal requirements for calculating insurable interest by state.
The purposes of the consent requirements and statutory requirements for insurable interest are to insure that a bank does not take out a death benefit policy on the life of an employee which exceeds the bank's loss. In general, a bank may take out a death benefit policy in the amount which is a multiple of 8-10 times the annual compensation of that employee. Annual compensation is the direct compensation which is taxable income to the employee in that year including any incentive awards.
The insurance carrier is responsible and punishable under state regulations for not complying with state insurable interest guidelines. Thus the bank is not directly responsible for not conforming with these guidelines. The bank, however, typically wants a warranty from the insurance carrier that they are purchasing a life insurance product as defined by the insurance statutes. For the insurance carrier to give such a warranty, the state insurable interest guidelines must be calculated and met.
Thus, the information needed to calculate insurable interest 172 are inputted into the system, including cost incurred due to the death of an employee, employee census data, life insurance company mortality tables, target premium amount, and employee benefit plan expenses. The insurable interest generator calculates individual premium and death benefit amounts using the target premium amount and insurable interest requirements.
FIG. 5 is a block flow diagram of the analytical system for sizing the BOLI transaction and generating performance estimates for the BOLI plan. Once the system calculates the BOLI premium amount which is in compliance with the Circular, determines death benefits according to the pertinent state statute, and meets bank investment parameters and OCC shareholder equity guidelines 192, the pro forma module 190 calculates performance estimates for the BOLI plan. These estimates are derived from financial information 194 inputted into the system, and translated into the pro forma categories 196.
One such pro forma category is Capital Ratios. In addition to the Circular, national banks are also required by the OCC to comply with so-called risk-based capital (or "RBC") requirements. Under these requirements, a bank must maintain at least a minimum amount of capital which varies depending upon, among other things, the perceived quality of its assets. In applying these requirements, a life insurance policy held as an asset is treated as having a "100 percent risk-weight," meaning that capital is required for 100 percent of the life insurance policy's cash surrender value. In contrast, the Treasury bills or other assets that a purchasing bank will have sold to buy BOLI may have a lower risk-weight (e.g., Treasury bills have a zero-percent risk weight), meaning that less (or no) capital was required with respect to these assets. Thus, by converting its assets into BOLI policies, a purchasing bank's minimum capital requirements could increase. In a marginal case, the acquisition of BOLI could require the bank either to attract more equity or to restrict the loans that it makes. A purchasing bank therefore must use capital, not borrowed money, to purchase BOLI in order to preserve its pre-purchase capital ratio and help meet its RBC requirements.
FIG. 6 shows a block flow diagram of the analytical system for completing allocation of the BOLI plan premium amount by business unit and employee 212. The premium allocatur 210 calculates regulatory requirements for each business unit and ensures the BOLI plan is in compliance 214.
FIG. 6 also shows a block flow diagram of the analytical system for implementing the BOLI plan. Although steps 232, 234, 236, and 238 are currently not part of the computer-based system, but rather are procedures which are initiated through information derived from the BOLI system, it is apparent that such steps can be implemented in computer form in future embodiments of the present invention. For example, it is envisioned that binder agreements between BOLI plan insurance companies and a bank could be handled in a paperless fashion utilizing computerized forms and signatures. Instead of executing agreements by written signature, electronic signatures could be affixed to electronic documents at the press of a keystroke, with hard copies distributed as a verification step. Similarly, master applications could be completed in an identical manner with the signatures of a bank officer being in electronic rather than handwritten form. Employee notification could be automated, and premium payments are already handled by wire transfers for the most part and could be simply and efficiently administered by the BOLI system as well. The computer-based BOLI system ensures that actual policies issued and premium amounts are reconciled 240.
FIG. 7 shows a block flow diagram of the analytical computer system for reinsuring the BOLI plan. Reinsuring the BOLI plan by a captive insurance subsidiary of the parent bank or holding company allows the bank to augment the cash value gains of the BOLI plan by providing cash revenue sources from fee income associated with investment and trust management. Reinsurance also minimizes the impact to the bank's profit and loss statement by keeping the assets within the corporate structure of the bank holding company. Furthermore, since a large portion of the premium assets remain within the reinsurance company, the premium assets left in the insurance company are minimized with respect to complying with the 15% institutional lending limit.
The preferred embodiment of the reinsurance module uses the share quota approach to reinsurance. The share quota approach and the relationship between the insurance company 106 and the reinsurance company 118 are defined by the reinsurance treaty 112. The reinsurance treaty 112 sets forth in detail the percentage of premiums the insurance company is to pay to the reinsurance company, and the risk sharing relationship and responsibilities of each party.
For example, the bank 100 purchases a BOLI plan with a hundred million dollar premium amount and one thousand policies. The reinsurance company will take a certain portion of the premium dollar amount in return for assuming the risk, liability, and investment performance requirements associated with that premium dollar amount. The reinsurance company could choose to acquire a fifty percent interest in all thousand policies or a one hundred percent interest in the first five hundred policies. The exact details will be defined in the reinsurance treaty.
The BOLI system administers and supports the steps required to implement the reinsurance plan. As shown in FIG. 7, the first step 252 in reinsuring the BOLI plan is to prepare and execute the reinsurance treaty. The second step 254 is to evaluate statutory restrictions of reinsurance policies and risk assumptions and ensure compliance. Both these steps are currently performed by hand, but could easily be converted into a component of the computer-based BOLI system.
The third step 256 is to model the reinsurance company's financials to measure impact on surplus and to test life company tax status. These steps are performed by the computer-based BOLI system.
To measure impact on surplus the financial statements of the acquiring reinsurer are examined to determine if it can support the risk. One aspect of this risk is determined by using certain financial assumptions. Take our example of one hundred million dollars of premium amount, and a fifty-fifty reinsurance relationship where the insurance company retains fifty-percent of the policies, or in other words, the reinsurance company is going to reinsure fifty million dollars of the premium amount. Assuming four dollars worth of death benefit for every dollar of premium, the mortality risk assumed by the reinsurance company is two hundred million dollars for this transaction. The financial position of the reinsurance company is modeled to determine the impact on surplus since this transaction causes a surplus drain. To prepare for this drain on surplus, a determination is made as to whether the reinsurance company has the necessary reserves or surplus to cover the potential mortality risk, or whether the bank or holding company (i.e., parent company) is going to transfer the necessary capital to the reinsurance company (i.e., captive insurance provider).
The second reason the reinsurance company's financials are examined is to ensure life company status. The reason for this is for tax purposes. Insurance companies are taxed differently depending on their status as a property and casualty company or life company. The reserves of life companies are not taxed. To have life company status the company must have fifty-percent of the company's premiums and reserves in the form of life insurance.
Thus, in our example of fifty million dollars worth of reinsurance, the inflow of fifty million dollars is going to dramatically affect even the largest reinsurer's balance sheet. This inflow of capital potentially impacts the life company status of the reinsurer, and must be evaluated.
The fourth step 258 is to prepare and execute the custodial trust agreement 114 and/or letter of credit between the insurance company, reinsurance company and trust company. The custodial trust agreement and/or letter of credit 114 is necessary since the reinsurance company is a captive subsidiary of the parent bank or holding company. Thus, to ensure an arms length relationship between the bank and the reinsurance company, the assets must be placed in a trust so that it is not commingled with any assets of the bank or other subsidiary of the holding company. This prevents the situation where the bank fails thus relieving the reinsurance company from its obligations and yet allowing the bank to demand full payment from the insurance company.
In addition to governing the trusteed assets, the custodial trust agreement 114 defines the relationship under which additional funds can be added or subtracted from the reinsurance arrangement. It also defines the minimum amounts that need to be on deposit at any point in time. The insurance company will want assurances that the reinsurance company has enough unencumbered reserves to meet the minimum requirements for the transaction.
Step five 260 involves ceding the business from the insurance company to the reinsurance company. "Ceding" is the technical term for actually moving the risk, assets and liabilities off the insurance company to the reinsurance company. This is executed through an automated reserve letter and ceding statement which contains calculation of ceding fees, premiums, claims, taxes, commissions and cash flow, risks and reserves assumed, and the "in force" calculations and descriptions of the mortality risk associated with the transaction. Inforce is a schedule which defines what risk the reinsurance company is assuming. In our previous example, if we use the share quota approach and will assume the premiums and risk for fifty-percent of the one hundred million dollar BOLI plan with one thousand policies, the inforce schedule will contain information on whether the reinsurance company will take fifty-percent of the one thousand policies or one-hundred percent of five hundred policies.
Step number six 262 requires the premiums received by the reinsurance company to be automatically invested according to Investment Committee Guidelines, which form a codicil of the custodial trust agreement. These guidelines are governed by federal and state insurance regulations, which are generally broader than those governing banks, and agreements made between the insurance and reinsurance company.
The seventh step 264 is performed by the computer-based BOLI system. On a monthly basis, investment income is calculated and charged against the expenses to determine the profit and loss on the transaction. Similarly, on a monthly basis step eight 266 is calculated to ensure that the stipulated minimum cash value of the BOLI plan that the bank originally purchased is on deposit. The Trustee will examine the reserves monthly and determine the amount of reserves needed to cover the amount of investment performance stipulated by the BOLI plan. If deficient, the difference will be made up from investment income or from additional paid-in capital from the reinsurance company.
In our example of a one hundred million dollar BOLI plan with fifty-percent being reinsured and a five percent growth in cash value per year, the cash value of the policies should amount to one hundred and five million at the end of year one. The reinsurance company must ensure that fifty-two million five hundred thousand dollars is in the reserves to cover the cash surrender value of the policies should they be surrendered. This is detailed in the reinsurance treaty.
Step nine 268 is accomplished by the computer-based BOLI system. The BOLI system records the BOLI plan reinsurance profit or loss by the reinsurance company. The determination of profit or loss depends on whether the generally accepted accounting principles (GAAP) or statutory accounting principles (STAT) are used.
FIG. 8 shows a block flow diagram for obtaining policy values and a listing of information required to obtain such policy values, showing the reports generated by the system and the administrative procedures performed by the present invention. The fronting company interface 270 takes insurance information such as billings, death benefits, cash values, dividends/excess interest credited, policy loans if any, withdrawals if any, interest due, claims in process for each of the accounts 272 from the insurance company and reinsurance company. The client reporting subsystem 290 takes this information and prepares reports 292 for the bank 100 showing the value of the transaction.
The administrative support subsystem 310 performs periodic sweeps of social security records to identify death claims for covered employees who have terminated or retired 312. Periodic employee status updates are also done to identify terminated or retired employees covered in the plan 314. This information is used as a basis for determining whether a policy has endowed. Endowment means that the life of the insured matches that defined by the policy. Thus, if the life insurance policy is a life to 95 policy, and if the insured lives to age 95, the policy is endowed.
At this point, alternative settlement options are evaluated 316. Typically, the cash value of the policy is left deposited with the insurance carrier, and the bank pays taxable interest on the gain from that point on since it technically no longer constitutes life insurance. Once the insured passes away, the bank receives the death benefits tax free. If the policy is surrendered before the insured passes away, all the accrued interest over the policy basis is treated as taxable gain. Thus, depending on the bank's need for capital at the particular moment of endowment drives the selection of the appropriate settlement option.
Although a preferred embodiment is specifically illustrated and described herein, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of this invention.
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The present invention involves a computer software and hardware system which smoothly integrates the following functions into an integrated computer-based system for designing and administering a BOLI plan for national banks under current federal and state guidelines and financial market constraints. The systems includes determining the highest BOLI premium permitted under OCC Banking Circular 9651, determining insurable interest requirements by accessing a database with the appropriate state's insurable interest guidelines, generating performance estimates for the BOLI plan and allocating premium amount by business unit and employee. The system also ensures that the BOLI plan is in compliance with the regulatory requirements for the business unit. In addition, the system reinsures the BOLI plan through a captive insurance company of the financial organization, obtaining policy values for the captive insurance company. Other aspects of the system include verifying, reconciling, consolidating and reporting policy values for the financial organization, and performing administrative procedures for the BOLI plan of the financial organization.
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This application claims the benefit of the Provisional Application No. 60/199,965, filed Apr. 27, 2000.
FIELD OF THE INVENTION
The invention relates to a system for moving a component part of a motor vehicle. In particular, the invention relates to an actuator used to selectively provide access to an enclosure of a motor vehicle.
DESCRIPTION OF THE RELATED ART
As motor vehicles characterized by their utility become a mainstream choice, consumers demand certain luxuries primarily associated with passenger cars, either due to their inherent design and/or size. One of the features desired by consumers is the automated movement of such items as sliding doors and lift gates. While features providing automated motion are available, the designs for mechanisms used to accommodate manual overrides are lacking in capability and functionality.
U.S. Pat. No. 5,144,769 discloses an automatic door operating system. This system requires a great deal of control, both by an electronic controller and an operator of the motor vehicle. To overcome forces due to manual operation, the manually operated seesaw switch used by the operator to electromechanically operate the door is in an open state, preventing current from passing through the motor. While this system may not generate a current, the iron core of the motor armature must move with respect thereto and this will create an inertial force and a magnetic loss that must be overcome. Further, there is no contemplation of overcoming the friction forces generated by the belt and transmission system that incorporates the use of the motor.
SUMMARY OF THE INVENTION
An automation assembly is adapted to be connected to a door system of a motor vehicle. The automation assembly includes a frame that is fixedly secured to the motor vehicle. A motor is fixedly secured to the frame and adapted to receive power. The motor converts the power into a rotational output force. The motor includes a non-ferrous core. A set of rollers are fixedly secured to the frame at predetermined positions. A continuous belt extends around the set of rollers and the motor. The belt is fixedly secured to the door system such that the motor moves the continuous belt and the door system bidirectionally between an open position and a closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a side view of a motor vehicle with a sliding side door in its open position;
FIG. 2 is a top view of one embodiment of the invention;
FIG. 3 is a top view of a second embodiment of the invention;
FIG. 4 is a top view, partially cut away, of a third embodiment of the invention;
FIG. 5 is a cross-sectional side view of the frame and motor utilized by the third embodiment of the invention;
FIG. 6 is a cross-sectional side view of a portion of the frame in a track utilized by the third embodiment of the invention;
FIG. 7 is a top view of a fourth embodiment of the invention;
FIG. 8 is an exploded perspective view of the fourth embodiment of the invention;
FIG. 9 is an exploded perspective view of the motor incorporated into the four embodiments of the invention; and
FIG. 10 is a cross-sectional side view of a portion of the frame incorporated into the fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the Figures, wherein like primed reference characters represent similar elements through the different embodiments of the invention, the invention 10 is generally a closure assembly for a motor vehicle 12 . Although the invention 10 will be described to be incorporated into and/or working in conjunction with a sliding door 14 of a minivan-styled motor vehicle 12 , it should be appreciated by those skilled in the art that the invention 10 is not limited to this style closure and motor vehicle.
Referring to FIGS. 2 and 3 , a coreless motor is generally indicated at 18 . The coreless motor 18 is used in an assembly to automatically move the sliding door 14 with respect to a specific frame of reference, i.e., the door opening 20 . The coreless motor 18 includes a housing 22 within which an ironless disk 24 is housed. Motor brushes (not shown) are connected to an electrical current via electrical leads (not shown). The disk 24 is secured to a motor output shaft 26 . A pinion gear 28 is mounted to the motor output shaft 26 and rotates therewith.
The pinion gear 28 rotates the drive gear 30 . The ratio of the pinion gear 28 with respect to the drive gear 30 is between 1:6 and 1:8. This allows the disk to have a smaller diameter than would otherwise be possible if the drive gear 30 was closer in diameter to the pinion gear 24 . In the preferred embodiment, the disk 24 has a diameter of approximately 10 mm. A pulley 32 is secured to the drive gear 30 such that there is no lost motion therebetween. The pulley 32 drives a belt 34 , discussed subsequently.
The coreless motor 18 is a direct current (DC) electrodynamic machine having its armature coil-turn windings (not shown) within the magnetic air-gap without using a ferrous material for a flux linkage. The absence of the ferrous core for flux linkage requires the diameter of the disk to be larger than would otherwise be needed. The coreless motor 18 does, however, generate less current when it is manually rotated in a direction opposite that in which the current flowing through the brushes would dictate. Likewise, less current is generated in the coreless motor 18 if the coreless motor 18 is not being operated. Therefore, a smaller force is needed to move the sliding door 14 manually without the aid of the automatic opening features. For a brush-commutated motor, the armature is the rotor and the field is the stator. For a brushless motor, the field rotates and the armature is the stator.
An electronic controller 36 controls the coreless motor 18 . It does so by receiving inputs from a motor encoder sensor 38 that determines the position of the belt 34 and the sliding door 14 with respect to the motor vehicle 12 .
Tensioning devices 40 are used to take up slack when the sliding door is moved manually. In the embodiment shown in FIG. 2 , the tensioning devices 40 are pulleys 44 with spring loaded plungers 42 . In the embodiment shown in FIG. 3 , a compression spring 42 ′ extends between the two pulleys 44 ′. A potentiometric sensor 46 ′ is used to identify the amount of potential stored within the spring 42 ′. If the spring 42 ′ is unbalanced, the electronic controller 36 ′ operates the coreless motor 18 ′ to return the spring 42 ′ to balance.
The presence of a back-driving force may be sensed in the interfacing transmission, i.e., the pinion gear 28 ′, the drive gear 30 ′ and the pulley 32 ′. Once sensed, the information is in a manner similar to feedback wherein the information is transmitted back to the electronic controller 36 ′ allowing it to then operate the coreless motor 18 ′. In this manner, the coreless motor 18 ′ would be operated to keep up with the movement of the sliding door 14 ′ eliminating the need for the operator to manually overcome the losses due to the coreless motor 18 ′ and the interfacing transmission. Sensing such movement may be accomplished using the belt path shown in FIG. 3 . This embodiment of the belt path includes a center spring 41 and the potentiometric sensor 46 ′. When the belt 34 ′ is being forced one direction or another, the center spring 41 is unbalanced. This unbalance is sensed by the potentiometric sensor 46 ′ and then transmitted to the electronic controller 36 ′ which, in turn, operates the coreless motor 18 ′ to attempt to return the center spring 41 to balance. Once the center spring 41 returns to steady state or balance, typically by the operator ceasing to move the sliding door 14 ′, the electronic controller 36 ′ stops the coreless motor 18 ′.
Referring to FIGS. 4 through 6 , a third embodiment of the invention 10 ″ is shown. The invention is an automated assembly 10 ″ adapted to operate the sliding door 14 ″ of the motor vehicle. The automated assembly 10 ″ includes a frame 48 . The frame 48 is moveable with respect to a track 50 used by the sliding door 14 ″ to move between the open and closed positions. The frame 48 slides along the track 50 using rollers (not shown).
The coreless motor 18 ″ is fixedly secured to the frame 48 . The coreless motor 18 ″ moves the frame 48 by rotating its output shaft 26 ″ to move a pulley (not shown). The pulley forces the frame 48 to move along the belt 34 ″. The belt 34 ″ in this embodiment is not continuous. The belt 34 ″ extends along a curved path between a first end 52 and a second end, graphically represented at 54 in FIG. 4 . In this embodiment, three guide pulleys 56 are shown directing the belt 34 ″ through its curved path.
Referring to FIG. 5 , the coreless motor 18 ″ is secured to the frame and driving the pinion gear 28 ″. The pinion gear 28 ″ then drives an intermediate spur gear set 58 . The intermediate spur gear set 58 drives a spur gear 60 and a bevel gear 62 .
Referring to FIG. 6 , the sliding door 14 ″ is shown with the lower hinge, i.e., the frame 48 attached thereto. A toothed drive pulley 64 drives the sliding door 14 ″ between its open and closed positions by rotating and forcing itself along the belt 34 ″. The bevel gear 62 rotates a second bevel gear 66 which, in turn, rotates a drive shaft 68 that drives the toothed drive pulley 64 .
Referring to FIGS. 7 through 10 , a fourth embodiment of the invention 10 ′″ is shown. The belt 34 ′″ is continuous in this embodiment as it was in the first two embodiments. The belt 34 ′″ rolls along pulleys 70 and rollers 72 . An attachment clip 74 secures the sliding door 14 ′″ to a single position with respect to the belt 34 ′″. Therefore, the sliding door 14 ′″ follows the belt 34 ′″ as the belt 34 ′″ moves between its extreme positions.
A frame 48 ′″ positions the pulleys 70 and rollers 72 and is secured to the coreless motor 18 ′″. The frame 48 ′″ and the coreless motor 18 ′″ are secured together via an intermediate bracket 76 and motor housing 78 . The intermediate bracket 76 includes an elongated opening 80 that allows the belt 34 ′″ to move around the coreless motor 18 ′″ and around the frame 48 ′″.
FIG. 10 illustrates the belt 34 ′″ and how it is secured to the frame 48 ′″. A load roller 82 aids in the movement of the sliding door 14 ′″. The belt 34 ′″ moves through a channel 84 in the frame 48 ′″ as the coreless motor 18 ′″ moves the belt 34 ′″ therearound. The positioning clip 74 ′″ includes an upper clip 86 and a lower clip 88 . The positioning clip 74 ′″ clamps on one portion of the belt 34 ′″. A guide roller 90 moves through the track 50 ′″ to help guide the sliding door 14 ′″ as it moves between the open and closed positions.
In all of the embodiments disclosed herein, the invention 10 , 10 ′, 10 ″, 10 ′″ is designed to be modular. More specifically, the automation assembly 10 , 10 ′, 10 ″, 10 ′″ is designed to be fit into a motor vehicle that was designed to have the option of whether the sliding door 14 is to be automatically driven or whether the sliding door 14 is to be strictly manually operated. Except for the belt in some of the embodiments, the entire assembly is designed to be secured to the motor vehicle as a single entity. This allows the assembly of the invention 10 to the motor vehicle 12 to be simple.
The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.
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An automation assembly is adapted to be connected to a door system of a motor vehicle. The automation assembly is modular and includes a frame that is fixedly secured to the motor vehicle. A motor is fixedly secured to the frame and adapted to receive power. The motor converts the power into a rotational output force. The motor includes a non-ferrous core. A set of pulleys and rollers are fixedly secured to the frame at predetermined positions to direct the path of a continuous belt. The continuous belt is fixedly secured to the door system such that the motor moves the continuous belt and the door system bidirectionally between an open position and a closed position. Sensors are used to determine the position of the door, the speed thereof and whether the door is being moved manually.
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RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 12/442,347, filed on Feb. 16, 2010, which application is a U.S. National Stage Filing under 35 U.S.C. 371 from International Application No. PCT/US2007/020472, filed on Sep. 21, 2007, and published as WO 2008/036395 A1 on Mar. 27, 2008; which application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 60/826,709, filed on Sep. 22, 2006, which applications and publication are incorporated herein by reference in their entirety.
FIELD
[0002] The subject matter relates to underground formation investigation, and more particularly, apparatus and methods for formation testing and fluid sampling within a borehole.
BACKGROUND
[0003] The oil and gas industry typically conducts comprehensive evaluation of underground hydrocarbon reservoirs prior to their development. Formation evaluation procedures generally involve collection of formation fluid samples for analysis of their hydrocarbon content, estimation of the formation permeability and directional uniformity, determination of the formation fluid pressure, and many others. Measurements of such parameters of the geological formation are typically performed using many devices including downhole formation testing tools.
[0004] During drilling of a wellbore, a drilling fluid (“mud”) is used to facilitate the drilling process and to maintain a pressure in the wellbore greater than the fluid pressure in the formations surrounding the wellbore. This is particularly important when drilling into formations where the pressure is abnormally high: if the fluid pressure in the borehole drops below the formation pressure, there is a risk of blowout of the well. As a result of this pressure difference, the drilling fluid penetrates into or invades the formations for varying radial depths (referred to generally as invaded zones) depending upon the types of formation and drilling fluid used. The formation testing tools retrieve formation fluids from the desired formations or zones of interest, test the retrieved fluids to ensure that the retrieved fluid is substantially free of mud filtrates, and collect such fluids in one or more chambers associated with the tool. The collected fluids are brought to the surface and analyzed to determine properties of such fluids and to determine the condition of the zones or formations from where such fluids have been collected.
[0005] One feature that all such testers have in common is a fluid sampling probe. This may consist of a durable rubber pad that is mechanically pressed against the rock formation adjacent the borehole, the pad being pressed hard enough to form a hydraulic seal. Through the pad is extended one end of a metal tube that also makes contact with the formation. This tube is connected to a sample chamber that, in turn, is connected to a pump that operates to tower the pressure at the attached probe. When the pressure in the probe is lowered below the pressure of the formation fluids, the formation fluids are drawn through the probe into the well bore to flush the invaded fluids prior to sampling. In some prior art devices, a fluid identification sensor determines when the fluid from the probe consists substantially of formation fluids; then a system of valves, tubes, sample chambers, and pumps makes it possible to recover one or more fluid samples that can be retrieved and analyzed when the sampling device is recovered from the borehole.
[0006] It is important that only uncontaminated fluids are collected, in the same condition in which they exist in the formations. Often the retrieved fluids are contaminated by drilling fluids. This may happen as a result of a poor seal between the sampling pad and the borehole wall, allowing borehole fluid to seep into the probe. The mudcake formed by the drilling fluids may allow some mud filtrate to continue to invade and seep around the pad. Even when there is an effective seal, borehole fluid (or some components of the borehole fluid) may “invade” the formation, particularly if it is a porous formation, and be drawn into the sampling probe along with connate formation fluids.
[0007] Additional problems arise in Drilling Early Evaluation Systems (EES) where fluid sampling is carried out very shortly after drilling the formation with a bit. Inflatable packers or pads cannot be used in such a system because they are easily damaged in the drilling environment. In addition, when the packers are extended to isolate the zone of interest, they completely fill the annulus between the drilling equipment and the wellbore and prevent circulation during testing.
[0008] There is a need for an apparatus that reduces the leakage of borehole fluid into the sampling probe, and also reduces the amount of borehole fluid contaminating the fluid being withdrawn from the formation by the probe. Additionally, there is a need for an apparatus that reduces the time spent on sampling and flushing of contaminated samples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a system for testing and drilling operations as constructed in accordance with at least one embodiment.
[0010] FIG. 2 illustrates a wireline system for drilling operations as constructed in accordance with at least one embodiment.
[0011] FIG. 3 illustrates a probe as constructed in accordance with at least one embodiment.
[0012] FIG. 4 illustrates a probe as constructed in accordance with at least one embodiment.
[0013] FIG. 5 illustrates a probe as constructed in accordance with at least one embodiment.
[0014] FIG. 6 illustrates a side view of a probe as constructed in accordance with at least one embodiment.
[0015] FIG. 7 illustrates a side view of a probe as constructed in accordance with at least one embodiment.
[0016] FIG. 8 illustrates a side view of a probe as constructed in accordance with at least one embodiment.
[0017] FIGS. 9-16 illustrates an example of a retractable wiper for a probe as constructed in accordance with at least one embodiment.
DESCRIPTION
[0018] In the following description of some embodiments of the present invention, reference is made to the accompanying drawings which form a part hereof, and in which are shown, by way of illustration, specific embodiments of the present invention which may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. The following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
[0019] FIG. 1 illustrates a system 100 for drilling operations. It should be noted that the system 100 can also include a system for pumping operations, or other operations. The system 100 includes a drilling rig 102 located at a surface 104 of a well. The drilling rig 102 provides support for a down hole apparatus, including a drill string 108 . The drill string 108 penetrates a rotary table 110 for drilling a borehole 112 through subsurface formations 114 . The drill string 108 includes a Kelly 116 (in the upper portion), a drill pipe 118 and a bottom hole assembly 120 (located at the lower portion of the drill pipe 118 ). The bottom hole assembly 120 may include drill collars 122 , a downhole tool 124 and a drill bit 126 . The downhole tool 124 may be any of a number of different types of tools including measurement-while-drilling (MWD) tools, logging-while-drilling (LWD) tools, etc.
[0020] During drilling operations, the drill string 108 (including the Kelly 116 , the drill pipe 118 and the bottom hole assembly 120 ) may be rotated by the rotary table 110 . In addition or alternative to such rotation, the bottom hole assembly 120 may also be rotated by a motor that is downhole. The drill collars 122 may be used to add weight to the drill bit 126 . The drill collars 122 also optionally stiffen the bottom hole assembly 120 allowing the bottom hole assembly 120 to transfer the weight to the drill bit 126 . The weight provided by the drill collars 122 also assists the drill bit 126 in the penetration of the surface 104 and the subsurface formations 114 .
[0021] During drilling operations, a mud pump 132 optionally pumps drilling fluid, for example, drilling mud, from a mud pit 134 through a hose 136 into the drill pipe 118 down to the drill bit 126 . The drilling fluid can flow out from the drill bit 126 and return back to the surface through an annular area 140 between the drill pipe 118 and the sides of the borehole 112 . The drilling fluid may then he returned to the mud pit 134 , for example via pipe 137 , and the fluid is filtered.
[0022] The downhole tool 124 may include one to a number of different sensors 145 , which monitor different downhole parameters and generate data that is stored within one or more different storage mediums within the downhole tool 124 . The type of downhole tool 12 . 4 and the type of sensors 145 thereon may be dependent on the type of downhole parameters being measured. Such parameters may include the downhole temperature and pressure, the various characteristics of the subsurface formations (such as resistivity, radiation, density, porosity, etc.), the characteristics of the borehole (e.g., size, shape, etc.), etc.
[0023] The downhole tool 124 further includes a power source 149 , such as a battery or generator. A generator could be powered either hydraulically or by the rotary power of the drill string. The downhole tool 124 includes a formation testing tool 150 , which can be powered by power source 149 . In an embodiment, the formation testing tool 150 is mounted on a drill collar l 22 The formation testing tool 150 includes a probe that engages the wall of the borehole 112 and extracts a sample of the fluid in the adjacent formation via a flow line. The probe includes one or more inner channels and one or more outer channels, where the one or more outer channels captures more contaminated fluid than the one or more inner channels. As will be described later in greater detail, the probe samples the formation and, in an option, inserts a fluid sample in a container 155 . In an option, the tool 150 injects the carrier 155 into the return mud stream that is flowing intermediate the borehole wall 112 and the drill string 108 , shown as drill collars 122 in FIG. 1 . The container(s) 155 flow in the return mud stream to the surface and to mud pit or reservoir 134 . A carrier extraction unit 160 is provided in the reservoir 134 , in an embodiment. The carrier extraction unit 160 removes the carrier(s) 155 from the drilling mud.
[0024] FIG. 1 further illustrates an embodiment of a wireline system 170 that includes a downhole tool body 171 coupled to a base 176 by a logging cable 174 . The logging cable 174 may include, but is not limited to, a wireline (multiple power and communication lines), a mono-cable (a single conductor), and a slick-line (no conductors for power or communications). The base 176 is positioned above ground and optionally includes support devices, communication devices, and computing devices. The tool body 171 houses a formation testing tool 150 that acquires samples from the formation. In an embodiment, the power source 149 is positioned in the tool body 171 to provide power to the formation testing tool 150 . The tool body 171 may further include additional testing equipment 172 . In operation, a wireline system 170 is typically sent downhole after the completion of a portion of the drilling. More specifically, the drill string 108 creates a borehole 112 . The drill string is removed and the wireline system 170 is inserted into the borehole 112 .
[0025] FIG. 2 illustrates the formation testing tool 150 in greater detail. As mentioned above, the formation testing tool 150 can be included on the wireline system 170 or a drilling system, for example. It should be noted the formation testing tool 150 can be included on other tools, including, but not limited to tools that lower themselves into the borehole. In FIG. 2 , an example of the wireline system is shown with formation testing tool 150 .
[0026] A portion of a borehole 201 is shown in a subterranean formation 207 . The borehole wall is covered by a mudcake 205 . The formation tester body 171 is connected to a wireline system 170 leading from a rig at the surface ( FIG. 1 ). The formation tester body 171 is provided with a mechanism, denoted by 210 , to clamp the tester body at a fixed position in the borehole. In an option, the clamping mechanism 210 is at the same depth as a probe 152 . Other mechanisms for engaging the probe 152 with the borehole include, but are not limited to inflatable packers.
[0027] In an example, a clamping mechanism 210 and a fluid sampling pad 213 are extended and mechanically pressed against the borehole wall. The fluid sampling pad 213 includes a probe 152 that has one or more outer channel 156 , and one or more inner channel 154 . The inner channel(s) 15 is disposed within at least a portion of the outer channel(s) 156 . In an option, the inner channel(s) 154 is extended from the center of the pad, through the mud cake 205 , and pressed into contact with the formation. For instance, the inner channel(s) 156 is connected by a hydraulic flow line 223 a to an inner channel sample chamber 227 a . In another option, the fluid sample pad 213 is extended via extendable members 211 ( FIGS. 6 and 7 ), and the inner and outer channels 154 , 156 can contact the formation. In an option, flow lines 223 a , 223 b for the inner and/or outer channels 154 , 156 extend through the extendable members 211 , and to their respective channels. In a further option, the probe 152 is an articulating probe, where the probe can hinge at one or more locations 184 ( FIG. 8 ) to contact the surface of a formation and borehole more readily.
[0028] The outer channel(s) 156 has one or more openings 158 ( FIG. 3 ) therealong, the openings being hydraulic connected with the formation thru the channel. Optionally the outer channel(s) can be directly contacting the formation. All of the openings can be connected to one or more hydraulic lines with in the body of the tool. In an option, the outer channel(s) 154 is connected by its own hydraulic flow line, 223 b , to an outer channel sample chamber, 227 b . Because the flow line 223 a of the inner channel(s) 154 and the flow line 223 b of the outer channel(s) 156 are separate, the fluid flowing into the outer channel(s) 156 does not mix with the fluid flowing into the inner channel(s) 154 . The outer channel(s) can 156 isolate the flow into the inner channel(s) 154 from the borehole beyond the pad 213 . In a further option, the inner channel flow line 223 a and/or the outer channel flow line 223 b extend through extendable members 204 ( FIGS. 6 and 7 ).
[0029] The hydraulic flow lines 223 a and 223 b are optionally provided with pressure transducers 211 a and 211 b . In an option, the pressure maintained in the outer channel flowline 223 b is the same as, or slightly less than, the pressure in the inner channel flowline 223 a . In another option, the pressure ratio maintained in the inner channel flowline 223 a to the outer channel flowline 223 b is about 2:1 to 1:2. In another option, the flow rates of the inner channel(s) 154 and the outer channel(s) 156 are regulated. For example, the flow rate ration of the inner channel(s) 154 to the outer channel(s) 156 is about 2:1 to 1:2. With the configuration of the pad 213 and the outer channel(s) 156 , contaminated borehole fluid that flows around the edges of the pad 213 is drawn into the outer channel(s) 156 , and diverted from entry into the inner channel(s) 154 .
[0030] The flow lines 223 a and 223 b are optionally provided with pumps 221 a and 221 b , or other devices for flowing fluid within the flow lines. The pumps 221 a and 221 b are operated long enough to substantially deplete the invaded zone in the vicinity of the pad 213 and to establish an equilibrium condition in which the fluid flowing into the inner channel(s) 154 is substantially free of contaminating borehole filtrate.
[0031] The flow lines 223 a and 223 b are also provided with fluid identification sensors, 219 a and 219 b . This makes it possible to compare the composition of the fluid in the inner channel flowline 223 a with the fluid in the outer channel flowline 223 b . During initial phases of operation, the composition of the two fluid samples will be the same; typically, both will be contaminated by the borehole fluid. These initial samples are discarded. As sampling proceeds, if the borehole fluid continues to flow from the borehole towards the inner channel(s) 154 , the contaminated fluid is drawn into the outer channel(s) 156 . Pumps 221 a and 221 b discharge the sampled fluid into the borehole. At some time, an equilibrium condition is reached in which contaminated fluid is drawn into the outer channel(s) 156 and uncontaminated fluid is drawn into the inner channel(s) 154 . The fluid identification sensors 219 a and 219 b are used to determine when this equilibrium condition has been reached. At this point, the fluid in the inner channel flowline is free or nearly free of contamination by borehole fluids. Valve 225 a is opened, allowing the fluid in the inner channel flowline 223 a to be collected in the inner channel sample chamber 227 a . Similarly, by opening valve 225 b , the fluid in the outer channel flowline 223 b is collected in the outer channel sample chamber 227 b . Alternatively, the fluid gathered in the outer channel(s) can be pumped to the borehole while the fluid in the inner channel flow line 223 a is directed to the inner channel sample chamber 227 a . Sensors that identify the composition of fluid in a flowline can also be provided, in an option.
[0032] FIGS. 3-5 illustrate additional variations for the probe 152 . The probe 152 is defined by a height 180 and a width 182 . In an option, the probe has an elongate shape and the height 180 is greater than the width 182 . This allows for the probe 152 to contact a greater number of laminates. In another option, the probe 152 has an overall oval shape.
[0033] As discussed above, the probe 152 includes inner and outer channels 154 , 156 , and the inner and outer channels 145 , 156 include a number of openings 158 or ports therein, where fluid flows through the openings 158 . The number of flow ports, in an option, in the outer channel(s) 156 is different than in the inner channel(s) 154 . In an option, the outer channels 156 have an overall oval, elongate shape and/or encircle with inner channel(s) 154 . While an elongate or oval shape are discussed, it should be noted other shapes for the probe or outer channels can be used. Furthermore, the area of the outer channel(s) 156 relative to the area of the inner channel(s) 154 can be varied, for example, as seen in FIGS. 3 and 4 . In another option, the outer channel(s) 156 do not completely encircle the inner channel(s) 154 , as shown in FIG. 5 . For example, the outer channel(s) 156 are disposed on one or more sides of the inner channel(s) 154 .
[0034] In a further option, the probe 152 includes an outer sealing member such as a seal 162 that encircles the outer channel(s) 156 , as shown in FIG. 3 . In further option, the probe 152 includes a seal 164 disposed between the outer channel(s) 156 and the inner channel(s) 154 , where the seal 164 is optionally retractable within the probe 152 . The seals 162 , 164 seal against the bore hole wall to enclose a contact surface therein. The seals can be made of elastomeric material, such as rubber, compatible with the well fluids and the physical and chemical conditions expected to be encountered in an underground formation.
[0035] The probe 152 can be operated, cleansed, or kept cleansed in a number of manners. For example, the probe 152 includes one or more screens 166 over the openings 158 . In an option, the one or more screens 166 are retractable to promote flow. Although only one screen 166 is shown in FIG. 3 , the screens 166 can be disposed over one or more of the openings 158 for the inner channel(s) 154 and/or the outer channel(s) 156 . In another option, the probe further includes at least one wiper that excludes or assists in excluding mud entry into the inner or outer channels.
[0036] In another example, fluid can be pumped through the probe 152 in various manners, such as out of the inner and/or outer channels 154 , 156 or into the inner and/or outer channels 145 , 156 . For instance, fluid is pumped through the probe 152 clearing the inner channel(s) 154 including pumping fluid out of the inner channel(s) 154 while optionally pumping into the outer channel(s) 156 . In a further option, fluid is pumped through the probe 152 clearing the outer channel(s) 156 including pumping fluid out of the outer channel(s) 156 while optionally pumping into the inner channel(s) 154 . In another option, fluid pump through the probe 152 is a selected fluid, such as a fluid that is capable of dissolving material that can clog formation pores near the probe. The fluid can be stored in a collection chamber that can be prefilled, or empty.
[0037] In yet another option, mud cake can be displaced, including removed, adjacent the seals, the inner channel member, or the outer channel member. For example, a wiper assembly as shown in FIG. 9-16 can be included with the above-discussed probe 152 . The wiper assembly includes a retractable wiper. The wiper can be used to remove or exclude mud cake from the probe as the pad sets.
[0038] Advantageously, the formation samples with low levels of contamination can be collected more quickly using the formation tester. Furthermore, the probe can be self cleaning without having to remove the probe from the borehole. This can increase the efficiency of the pumping or drilling operations. Furthermore, the probe allows for a thin layer or fracture to be identified because the probe can capture a layer or fracture by spanning vertically along the well bore.
[0039] Reference in the specification to “an option,” “an embodiment,” “one embodiment,” “some embodiments,” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the options or embodiments is included in at least some embodiments, but not necessarily all embodiments, of the invention. The various appearances of “an embodiment,” “one embodiment,” or “some embodiments” are not necessarily all referring to the same embodiments.
[0040] Although specific embodiments have been described and illustrated herein, it will be appreciated by those skilled in the art, having the benefit of the present disclosure, that any arrangement which is intended to achieve the same purpose may be substituted for a specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
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Apparatus and methods for downhole formation testing including use of a probe having inner and outer channels adapted to collect or inject injecting fluids from or to a formation accessed by a borehole. The probe straddles one or more layers in laminated or fractured formations and uses the inner channels to collect fluid.
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FIELD OF THE INVENTION
The present invention relates to an apparatus for regularly collecting pipes, rods and similar objects.
BACKGROUND OF THE INVENTION
An apparatus is already known in which a transfer rail is connected with a U-shaped rigid rack at the tip thereof, to a receiving rack; pipes or similar objects are transfered from the rail down into the receiving rack. The known apparatus has some defects, for example, a loud noise is made when the pipes collide with each other. The surfaces of the pipes are also injured as the result of the collision. Another kind of apparatus has been developed in order to eliminate these defects. An inclining flexible belt is substituted in place of the above-described U-shaped rack. The belt, in the latter apparatus, is positioned at the end of the transfer rail and receives the pipes continuously one by one into its hollow space. The receiving space become gradually bigger and deeper as the belt is pulled downward by the weight of the pipes; the greater the number of pipes, the further the belt is pulled downward, until some limit is reached. The pipes received onto the belt stand in a row until the last pipe is flush with the transfer rail. Succeeding pipes entering into the space will fiercely roll down over the row of the pipes already received, thereby making loud noise and damaging the surface of the pipes. In addition, the pipes, are so irregularly collected into the belt space that they can not be easily bundled and lifted upward.
SUMMARY OF THE INVENTION
The present invention offers an apparatus which collects pipes, rods and similar articles parallel to each other, and which includes a transfer rail and a pair of roller chains supported by a device comprising a pair of feed sprockets, a pair of take-up sprockets, a pair of swing sprockets and a pair of front and rear props. The feed sprockets are rotatably fixed on the upper portion of the front props. The take-up sprockets are rotatably fixed on the upper portion of the rear props. The feed sprockets drive the roller chains faster than the take-up sprockets. Thus, the roller chains between the feed sprockets and the take-up sprockets will expand downward by the swinging motion of the swing sprockets. The section of the roller chains between the feed sprockets and take-up sprockets receives the pipes.
The apparatus in accordance with the present invention can receive pipes or similar articles smoothly and in regular sequence. The pipes are regularly collected to form an equilateral polygon when viewed from the side.
The structure of the apparatus will be understood and certain of its advantages more fully appreciated from the detailed description which follows, read in connection with the accompanying drawings illustrating practical embodiments of the apparatus in which the invention may be practiced.
IN THE DRAWINGS
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side plan view of a first embodiment of the invention;
FIG. 2 is a top plan view of the first embodiment of the invention;
FIGS. 3,4,5 and 6 are diagrammatic side plan views of the first embodiment of the invention showing the process of collecting the pipes;
FIG. 7 is a diagrammatic side plan view showing the oil-hydraulic system in said first embodiment of the invention; and
FIG. 8 is a diagrammatic side plan view of a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 and FIG. 2, 1 and 2 show, respectively, the front and rear props located at certain intervals. The rear props 2 are higher than the front props 1. The right and left sides of the apparatus are equipped with props 1 and 2. The top end of the front props 1 are connected to inclined transfer rails 3 and the lowest end thereof. The rear props 2 which are elbow-shaped and project backward, are fixed to a shaft 6.
The shaft 6 is rotatable within certain angular limits and is supported by bearings 5 fixed to the lower surface of the bottom frame 4. Levers 7 are also fixed at one end to the shaft 6, and connected at their other end to fluid-cylinders 8. Thus, the above-mentioned rear props 2 can be caused to swing forward and backward by the levers 7, driven by the fluid-cylinders 8.
Each feed sprocket 9 is fixed revolvably upon the top of a bracket 10, attached to the upper portion of the props 1. The sprockets 9 stand close to the tip ends of the transfer rails 3. The symbol 11 indicates take-up sprockets fixed revolvably upon the top of the rear props 2. The take-up sprockets 11 and the feed sprockets 9 are idle wheels of the same diameter. The symbol 12 indicates endless flexible strips of roller chains. The roller chains 12 are mounted on the feed sprockets 9, the take-up sprockets 11, intermediate sprockets 13, 14, driving sprockets 15, 16 and swing sprockets 17. The roller chains 12 rotate in the direction indicated by the arrows in FIG. 1. Intermediate sprockets 13 are fixed to the lower portion of the rear props 2, and the other intermediate sprockets 14 are fixed to the rear bottom portion of frame bases 18. The driving sprockets 15 are fixed to a shaft 44, supported rotatably by the rear end portions of the bases 18, half way up the bases 18. The other driving sprockets 16 are fixed to a shaft 45 rotatably supported upon the brackets 10, at the lower portions thereof. Sprockets 13-17 have the same diameter as the foregoing sprockets 9 and 11.
The swing sprockets 17 are freely rotatably fixed upon the top of levers 20 supported by the frame bases 18. The levers 20 are caused to swing forward and backward by fluid-cylinders 21 within certain angular limits.
The symbol 22 indicates a cyclo-reduction gear driven by an oil-hydraulic motor 23. A pinion 24, installed onto the output shaft of the cyclo-reduction gear 22, drives, via a chain 54, a sprocket 25, fixed to the above-mentioned shaft 44, holding the driving sprockets 15. The pinion 24 further drives, via chain 54, and large sprockets 26, sprockets 27 which are fixed to the shafts 45, holding the driving sprockets 16. In this way, the roller chains 12 are driven in the direction indicated by the arrow in FIG. 1.
It will be understood from the above description that the driving sprockets 16 are devised so as to rotate faster than the driving sprockets 15. The diameter of the sprockets 26 is larger than that of the sprockets 27, and the sprockets 26 and 27 are connected respectively to driving sprockets 15 and 16 through respective common shafts 44 and 45. Therefore, the speed of the part of the roller chains 12 engaging feed sprockets 9 under the direct influence of the driving sprockets 16, is greater than the speed of that part of the same roller chains engaging the take up sprockets 11, under the indirect influence of the driving sprockets 15 through the intermediate sprockets 14 and 13. Because of the difference in the speeds of various parts of roller chains 12, the roller chains 12 will hang down between sprockets 9 and 11.
The symbol 28 indicates stoppers. The bottom ends of the stoppers 28 are fixed to a shaft 31, supported rotatably with bearings 30. The bearings 30 are attached to the lower surfaces of frame tops 29, said frame tops 29 supporting the transfer rails 3 at the upper surfaces thereof. The symbol 32 indicates levers whose top ends are fixed to the shafts 31, and whose bottom ends are joined to fluid-cylinders 33. Accordingly, when the fluid cylinders 33 are actuated the top portions of the stoppers 28 are raised above the transfer rails 3 and then brought down below the transfer rails 3.
A roller conveyor 34 is positioned near the entrance of the transfer rails 3 at right angles thereto. The symbol 35 indicates kickers supplying the pipes or similar articles to the rails 3 from the said conveyor 34.
The operation of the embodiment having the construction described above is explained as follows.
The rear props 2 are tilted slightly forward by the motion of the fluid-cylinders 8. The fluid-cylinders 21 are then activated and the swing sprockets 17 are shifted to their most forward position by the levers 20. The roller chains 12 are consequently stretched and straightened between the feed sprockets 9 and the take-up sprockets 11. Further, the stoppers 28 are lifted above the transfer rails 3 by the motion of the fluid-cylinders 33, acting through the levers 32.
In the above state of the apparatus, the pipes or similar articles on the roller conveyor 34 are then supplied in order, onto the transfer rails 3 by the kickers 35. Those pipes will roll down toward the stoppers 28 and rest on transfer rails 3, thereupon lying in a parallel row. Next, the stoppers 28 are retracted to put the forefront pipe "a" in contact with the roller chains 12 supported under tension by the feed sprockets 9 and the take-up sprockets 11, as shown in FIG. 3.
The cyclo-reduction gear 22 is now put into operation to drive-pinion 24. The pinion 24 drives the sprocket 25 by means of a chain 54. The large sprockets 26, fixed to the same shaft as said sprocket 25, will drive, in turn, the sprockets 27. The driving sprockets 15 are fixed to the same shaft 44 as sprockets 26, and the driving sprockets 16 are fixed to the same shaft 45 as sprockets 27. Thus, driving sprockets 15 and 16 drive the roller chains 12 in the direction indicated by the arrows in FIG. 1. It will be here noted that the driving sprockets 16 make more revolutions per minute than driving sprockets 15, because of the larger diameter of the sprockets 26 compared with that of the sprockets 27. As a result, the feed sprockets 9 driven by the sprockets 16 will make more revolutions than the take-up sprockets 11 driven by the sprockets 15 through the sprockets 14 and 13.
Consequently, the length of the roller chains 12 fed by the feed sprockets 9 is longer than that taken up by the take-up sprockets 11. The roller chains 12 will thus be loosened between said feed sprockets 9 and take-up sprockets 11. At the same time, the roller chains 12 are stretched at the front (entrance) side of the feed sprockets 9.
The swing sprockets 17 will be subsequently drawn toward the feed sprockets 9 by the power of the fluid-cylinders 21, stressing the roller chains 12 as shown in FIG. 7. In this way, the roller chains 12 will hang gradually deeper and deeper between the said feed sprockets 9 and take-up 11, moving toward the latter sprockets.
The pipes are delivered one by one to roller chains 12, and are moved along with the roller chains 12. The pipes are received into the space made by the roller chains 12 and bundled up thereby into a bundle in the shape of regular polygon when viewed from the side shown in FIGS. 4,5 and 6.
The horizontal distance "A" between the feed sprockets 9 and the take-up sprockets 11 should be preferably increased when the number of pipes to be received is increased. As a result of experiments, the relation shown in Table 1 between said distance "A" and the number of the pipes to be received, was found to give good performance by the apparatus;
Table 1______________________________________Number of pipes or Horizontal distance "A" betweenthe like received the feed and take-up sprockets______________________________________0˜7 2D 8˜19 3D20˜37 4D______________________________________
where "D" signifies the diameter of the pipes or similar articles.
In regard to the ratio of the peripheral velocity of the feed sprockets 9 to that of the take-up sprockets 11, it was found that the ratio should be decreased when the number of pipes or similar articles to be received increases. According to experimental results, the relation between said parameters as shown in Table 2 was found to be desirable for satisfactory performance of the apparatus;
Table 2______________________________________ Ratio of the peripheral velocityNumber of pipes of the feed sprockets 9 to that ofreceived the take-up sprockets 11______________________________________ ˜9 2:119˜37 1.75:137˜61 1.5:1______________________________________
where the ratio 1.66:1 is taken as an average value.
After the predetermined number of the pipes or similar articles on the transfer rails 3 have been received into the hollow space formed by the roller chains 12, the fluid-cylinders 33 are then operated to raise up the stoppers 28 above the rails 3. The stoppers 28 be held there until the next cycle will starts. The cyclo-reducing gear 22 is simultaneously stopped to rest the roller chains 12. The fluid-cylinders 8 are next put into operation to rotate the rear props 2 backward. The distance between the feed sprockets 9 and take-up sprockets 11 is thus so enlarged that the received pipes or similar articles may be easily taken out from the above mentioned space.
In addition to the above operations, the fluid cylinders 21 are then activated bringing the swing sprockets 17 forward by the motion of the levers 20; the roller chains 12 are simultaneously circulated in the reverse direction by the reverse revolution of the feed sprockets 9, and the take-up sprockets 11. The roller chains 12 are in this way stretched again between the feed sprockets 9 and the take-up sprockets 11.
The roller chains 12 are used as endless flexible strips in the embodiment described above. However, the present invention is not restricted to using roller chains 12 to function as flexible strips. A kind of timing belt, for example, can be adoped. In addition, ordinary belts might be used as shown in FIG. 8. In this said embodiment, an endless ordinary belt 12' is mounted over feed wheels 9', take-up wheels 11', lower intermediate wheels 13', swing wheels 17' and driving wheels 16'.
The swing wheels 17' are capable of moving forward and backward under the action of the piston rods of the fluid-cylinders 21. Accordingly, said swing wheels 17' stretch up or loosen the belt 12' between the feed wheels 9' and the take-up wheels 11', in the same manner as in the first embodiment. When occasion demands, the apparatus is equipped with a pinch wheel 47 engaging the driving wheels 16'. The pinch wheel 47 thrusts the belt 12' upon the wheel 16' giving a stronger tension to the portion of the belt 12' and not between the wheels 9' and 11'.
As described above, the structure of the apparatus in the present invention is summarized as follows. The rear props 2 are located to the rear of the front props 1, said rear props 2 being higher than said front props 2. The right and left sides of the apparatus are equipped with front props 1 and rear props 2; feed wheels or sprockets 9, 9' and the take-up wheels or sprockets 11, 11' are rotatably supported, respectively on the tops of said front props 1 and rear props 2; the roller chains 12 or ordinary belts 12' are mounted onto said feed and take-up wheels or sprockets 9,11 or 9', 11' and the swing wheels 17 or swing sprockets 17' moved forward, to the feed wheels 9' or feed sprockets 9 and backward; the driving mechanism for said roller chains 12 or belts 12' circulating said roller chains 12 or belt 12' from the feed wheels 9' or feed sprockets 9 to the take-up wheels 11' or take-up sprockets 11; said driving mechanism also causes the feed wheels 9' or feed sprockets 9 to be rotated with higher peripheral velocity than the take-up wheels 11 or take-up sprockets 11.
As a result of the operation of the above-mentioned structure, said roller chains 12 or belts 12', receiving the pipes or similar articles, move in the direction from the feed sprockets 9 or feed wheels 9' to the take-up wheels 11' or take-up sprockets 11, and are simultaneously pulled down gradually, between the feed sprockets 9 or feed wheels 9' and take-up wheels 11' or take-up sprockets 11.
The many advantages over prior conventional apparatuses include: the pipes or similar articles are quietly and softly received without any harsh collision thereamong; the pipes or similar articles already received move together with the roller chains 12 or belts 12', thus smoothing the way for the next pipe or similar articles; the pipes or the like are protected from damages and injuries; and the pipes or similar articles are automatically gathered to make a preliminary polygonal assemblies for easier succeeding operations, such as tying, hoisting and carrying out.
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An apparatus which collects pipes, rods and similar objects parallel one another, to form a bundle. The apparatus includes at least one pair of transfer rails from which the pipes are transferred to a pair of roller chains where the pipes are collected. The roller chains are mounted on driving sprockets, swing sprockets, feed sprockets and take-up sprockets. The velocity of the take-up sprockets is lower than the velocity of the feed sprockets, causing the roller chain to sag therebetween, creating a space to collect the pipes.
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PRIORITY
[0001] This invention claims priority from provisional patent applications No. 61/073,109 filed Jun. 17, 2008 and 61/073,456 filed Jun. 18, 2009 the contents of each are herein incorporated by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
[0002] This invention was made with Government support under Contract DE-AC0576RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention generally relates to fuel cells and more particularly to seals for fuel cells such as solid oxide fuel cells.
[0005] 2. Background Information
[0006] High temperature electromechanical devices such as solid oxide fuel cells (SOFC) require a critical seal to separate different materials such as gasses. However, as these seals under go successive thermal cycling during routine operations they can become brittle and break. In addition, these seals must be able to have a sufficient amount of mechanical strength so as to withstand the structural strains required by typical use. While various materials have been attempted in trying to provide a seal that provides for these properties, an acceptable material has not as of yet been provided. The present invention however provides a seal that overcomes at least one of these sealing problems.
[0007] Additional advantages and novel features of the present invention will be set forth as follows and will be readily apparent from the descriptions and demonstrations set forth herein. Accordingly, the following descriptions of the present invention should be seen as illustrative of the invention and not as limiting in any way.
SUMMARY
[0008] The present invention is a seal for device such as a solid oxide fuel cell. The seal is a double seal having a first sealing material having a first preselected characteristic and a second sealing material having a second sealing characteristic. In one embodiment of the invention the first sealing material is a compressive sealing material and the second sealing material is a hermetic sealing material. Examples of this embodiment include those applications wherein the compressive sealing material is a mica-based seal and the hermetic sealing material is a glass sealing material. In other applications and embodiments the compressive material may be any material that can withstand the associated mechanical and thermal stresses. These include materials such as expanded vermiculite, graphite, and composites containing each. The hermetic sealing material can be any material that provides an appropriate gas-tight seal under the associated conditions these include glass materials, brazes or metallic composites containing brazing material.
[0009] In some embodiments a dimensional stabilizer may also be included as a part of the seal. Examples of materials that could serve as dimensional stabilizers include metal oxides such as Al2O3, MgO and ZrO2; as well as other materials such as simple or complex oxides which have melting temperatures higher than the general operation conditions for solid oxide fuel cells. In use these seals are typically positioned between two portions of a solid oxide fuel cell stack such as between the cell frame and interconnect as is shown the detailed description below. This double sealing concept provides superior thermal cycling stability in electrochemical devices where gasses must be separated from each other. While this exemplary example has been provided, it is to be distinctly understood that the invention is not limited thereto but maybe variously alternatively embodied according to the needs and necessities of the respective users.
[0010] The purpose of the foregoing abstract is to enable the United States Patent and Trademark Office and the public generally, especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0011] Various advantages and novel features of the present invention are described herein and will become further readily apparent to those skilled in this art from the following detailed description. In the preceding and following descriptions I have shown and described only the preferred embodiment of the invention, by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of modification in various respects without departing from the invention. Accordingly, the drawings and description of the preferred embodiment set forth hereafter are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic view of a first embodiment of the present invention
[0013] FIG. 2 is schematic side view of a portion of a solid oxide fuel showing the placement and location of one embodiment of the present invention having a top plan view of the embodiment of the invention shown in FIG. 1 .
[0014] FIG. 3 shows a schematic view of a solid oxide fuel cell demonstrating the presence of the seal of the present invention.
[0015] FIG. 4 shows the results of testing of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore the present description should be seen as illustrative and not limiting. While the invention is susceptible of various modifications and alternative constructions. It should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0017] FIGS. 1-2 show various embodiments of the present invention. Referring first to FIG. 1 a schematic of a single cross section of a single cell assembly is shown. In this embodiment, the double seal 10 is comprised of a first sealing material 12 and a second sealing material 14 placed between an interconnect anode 2 and an interconnect cathode 4 . In this embodiment of the invention the first sealing material 12 is a compressive sealing material, such as compressive mica such as the one described. The term “mica” encompasses a group of complex aluminosilicate minerals having a layer structure with varying chemical compositions and physical properties. More particularly, mica is a complex hydrous silicate of aluminum, containing potassium, magnesium, iron, sodium, fluorine and/or lithium, and also traces of several other elements. It is stable and completely inert to the action of water, acids (except hydro-fluoric and concentrated sulfuric) alkalis, convention solvents, oils and is virtually unaffected by atmospheric action. Stoichiometrically, common micas can be described as follows:
[0000] AB 2-3 (Al, Si) Si 3 O 10 (F, OH) 2
[0000] where A=K, Ca, Na, or Ba and sometimes other elements, and where B=Al, Li, Fe, or Mg. Although there are a wide variety of micas, the following six forms make up most of the common types: Biotite (K 2 (Mg, Fe) 2 (OH) 2 (AlSi 3 ) 10 )), Fuchsite (iron-rich Biotite), Lepidolite (LiKAl 2 (OH, F) 2 (Si 2 O 5 ) 2 ), Muscovite (KAl 2 (OH) 2 (AlSi 3 O 10 )), Phlogopite (KMg 3 Al(OH)Si 4 O 10 )) and Zinnwaldite (similar to Lepidolite, but iron-rich). Mica can be obtained commercially in either a paper form or in a single crystal form, each form of which is encompassed by various embodiments of the invention. Mica in paper form is typically composed of mica flakes and a binder, such as, for example, an organic binder such as a silicone binder or an epoxy, and can be formed in various thicknesses, often from about 50 microns up to a few millimeters. Mica in single crystal form is obtained by direct cleavage from natural mica deposits, and typically is not mixed with polymers or binders.
[0018] In addition to this material a variety of other compressive materials may also be utilized examples of other compressive materials include expanded vermiculite, graphite, and composites containing either or both. The second material is preferably a hermetic sealing material such as a glass material like alkaline earth (Ba, Ca, Sr, Mg) aluminosilicates glasses, borate glasses, silicate glass containing rare earth, or alkali-containing silicate/borate glasses. In addition to glass other hermetic sealing materials including brazes such as precious metal based brazes, brazing materials containing active agent such (copper oxide), or composites containing brazing materials and other materials may also be utilized.
[0019] The present invention thus provides high-temperature electrochemical devices such as solid oxide fuel cell (SOFC), solid oxide electrolysis cell (SOEC), gas permeation membranes and others critical seals to separate different gases in the device. Referring now to FIGS. 2 and 3 , FIGS. 2 and 3 show schematic drawings of the cross-section view of a repeating unit cell consisting of the interconnect plates 2 , 4 (anode and cathode side), a ceramic positive electrode-electrolyte-negative electrode (PEN) plate 6 sealed onto a metallic window-frame plate 8 , contact materials 18 at both electrodes, and seals 10 . With a standard single seal the failure probability increases substantially, if not proportionally when using only one particular seal at one particular sealing location. However in the present invention the combination of a compressive seal material and a hermetic seal material provides increased advantages in that it protects and supports the seal and keeps the contact (compressive) load in the planar SOFC/SOEC stacks to keep good contact of tens of repeating unit cells in spite of the fact that temperature distribution would not be isothermal throughout the whole stack during transient heating/cooling or even steady-state operations.
[0020] The present invention thus overcomes the prior art problems associated with dimensional shrinkage of the sealing materials by creep, plastic deformation or viscous flow especially for glass seal or metallic brazes. This prevents localized opening stress pushing up the ceramic PEN plate from the window-frame plate which typically leads to failure.
[0021] In this preferred embodiment of the invention set forth in FIGS. 2 and 3 , the seal 10 includes a mica-based compressive seal gasket 12 and a hermetic seal 14 such as glass or brazes at the same sealing location to form the double seal. In addition a dimensional stabilizer 16 such as a crystalline mineral with layer structure and a ceramic material (such as Al2O3, MgO, ZrO2 etc) placed on the other side of the PEN to window-frame seal offers another control to assist with dimensional stability. Together the proposed novel seal assembly offered the best seal system for planar SOFC/SOEC to a much controlled dimensional change, to withstand numerous thermal cycling and long-time operation in a harsh environment
[0022] A demonstration of this invention was carried out on a single commercial cell (2″×2″) sealed onto a SS441 window-frame plate with a high-temperature sealing glass. The pre-sealed cell/window-frame couple was then assembled with a SS441 anode plate and a SS441 cathode plate. Conducting contact pastes were also applied at the anode and cathode with the dimensional stabilizer (alumina in paste form) applied on the opposite of the window-frame glass seal. The double seal was composed of a glass seal in paste form along the inner seal circumference and the hybrid mica using phlogopite mica sandwiched between two layers of Ag foil along the outer seal circumference. This single cell “stack” was then sandwiched between two heat-exchanger blocks to pre-heat the incoming fuel and air. The seal between heat-exchanger blocks and the mating electrode plates was hybrid mica with Ag interlayers. The whole assembly was pressed at 10 psi and slowly heated to elevated temperatures by first to 550° C. for binder burn-off, followed by 950° C. for sealing, 800° C. for crystallization, and then to 750° C. for open circuit voltage (OCV) measurement. The fuel was 97% H2 and 3% H2O and the oxidizer was air. The theoretical (Nernst) voltage for this concentration of fuel and air at 750° C. was 1.110 V. The cell's OCV was then monitored versus thermal cycling. The temperature profile for each thermal cycle was heated from room temperature to 750° C. in 3 hrs, held at 750° C. for 3 hrs, and then cooled first in a controlled manner followed by natural furnace cooling. The total period of time for each cycle was 24 hours. The measured OCV versus 25 thermal cycles is shown in FIG. 4 . Clearly the current double seal with dimensional control demonstrated the excellent thermal cycle stability with nearly constant OCV of 1.104-1.106V at 750° C.
[0023] This invention could well advance the technologies of solid oxide fuel cells, solid oxide electrolysis cells, and gas permeation membranes operated at elevated temperatures and would experience numerous thermal cycling during routine operations. These high-temperature electrochemical devices would be used in stationary power generation as small units or large units, military applications for providing low-noise power in rural or hostile areas, auxiliary power units for transportation applications, and gas separation/generation related chemical industries. The unique advantage is the superior thermal cycle stability over the existing technologies where single seal is used for each particular sealing area.
[0024] While various preferred embodiments of the invention are shown and described, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.
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A seal for devices such as a solid oxide fuel cells. The seal is a double seal having a first sealing material having a first preselected characteristic and a second sealing material having a second sealing characteristic. In one embodiment of the invention the first sealing material is a compressive sealing material and the second sealing material is a hermetic sealing material. In some embodiments a dimensional stabilizer may also be included as a part of the seal. In use these double seals provide superior thermal cycling stability in electrochemical devices where gasses must be separated from each other.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/447,509, filed Feb. 28, 2011, and is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present disclosure is directed to an attachment to a pet training device, such as a clicker used to train a dog.
[0003] Training animals to behave as desired is an important aspect of pet ownership, and to this end many training techniques have been utilized over the years. One ubiquitous method of training a dog, for example, uses a clicking device that takes advantage of the phenomenon famously documented by Ivan Pavlov in which an animal can, over time, be conditioned to associate a pleasurable event (in Pavlov's experiment, being fed) with an auditory sound or other event, even to the extent that the animal enjoys the auditory sound itself.
[0004] In this method, the dog or other pet is repetitiously given a treat, or other reward, simultaneously with activation of a hand-held clicker after behaving in a desired manner. Eventually, the pet begins to associate the clicking sound itself as a reward, after which a pet owner may simply use the clicker to indicate to the pet approval of behavior.
[0005] A typical pet clicker is described in U.S. Pat. No. 7,674,153 and comprises a rigid housing surrounding an actuation member that, when actuated—usually by depression with the digit of a hand—emits a clicking sound. Usually, this sound is produced by the deflection of one end of a thin piece of metal relative to another end. Also, when the metal piece is affixed inside the cavity of a housing surrounding the metal piece, that sound may be amplified somewhat. A typical pet clicker may include an aperture at one end of the housing with which to attach the clicker to a key chain, wrist band, or other device to secure the clicker to a belt loop, a hand, etc.
[0006] To be effective, the pet clicker is preferably activated as quickly as possible after the pet behaves in a desired manner. One problem that arises is that the pet clicker, when dangling from a wrist or a belt loop, is not ready for activation quickly enough to be of use, as the pet may have changed its behavior while a person grasps for the clicker and positions it in an orientation in which it can be manually actuated, after which the pet would be “rewarded” for the wrong behavior. Conceivably, a pet owner, when walking a dog, for example, could always keep the pet clicker in hand and ready to click the instant it is desired, but this is often inconvenient as the owners hands may be needed for, say, throwing a ball or other matters.
[0007] What is desired, therefore, is an improved pet training apparatus that improves the speed at which a pet training device may be actuated from a position that is not grasped in a person's hand.
BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS
[0008] FIG. 1A shows a perspective view of a first exemplary attachment to a pet training device.
[0009] FIG. 1B shows a perspective view of the attachment shown in FIG. 1A , secured to both the digit of a person's hand and a pet training device in a first orientation, and also shows a phantom view of a second orientation , displaced form the first orientation, of the attachment of FIG. 1A and the attached pet training device.
[0010] FIG. 2A shows a perspective view of a second exemplary attachment to a pet training device.
[0011] FIG. 2B shows a perspective view of the attachment shown in FIG. 2A , secured to a pet training device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] Referring to FIGS. 1A and 1B , an exemplary attachment 10 to a pet training device, such as the device 12 (in this example a dog clicker) is shown, in which an auditory sound or other activation signal is emitted upon activation after depression of an activation surface 30 on the device 12 . The attachment 10 may include a first end 14 selectively securable to the pet training device 12 . For example, because most existing dog clickers include an opening 32 for securing a key chain, wristband, etc., an attachment 10 for a pet training device that is a dog clicker 12 may have a first end 14 comprising an appropriately-sized peg-portion 16 and a flexible anchor 18 having a diameter in a relaxed state that is larger than that of the opening 32 , such that that the peg portion 16 may be inserted through the opening 32 and then used to pull the anchor 18 that so that it squeezes through the opening 32 , as well, after which the anchor 18 relaxes and secures the attachment 10 to the device 12 . It should be appreciated that other means of securing an attachment 10 to a pet training device may be appropriate, depending on the pet training device. Conceivably, for example, a pet training device may be equipped with a clevis-type mount, such that a first end 14 would only need an appropriately-sized aperture to line up with those on either side of the clevis, and a securing pin used to complete the connection. It is also desirable, though not necessary, that the first end 14 be selectively detachable from the device 12 so that it can alternately be attached to other pet training devices. For example, as can be seen in the figures, the anchor 18 may be squeezed back through the opening 32 to detach the attachment 10 from the clicker 12 .
[0013] The exemplary attachment 10 may also include a second end 22 for selectively attaching the attachment 10 to a digit of a person's hand, such as a thumb. In this example, the second end 22 is a flexible ring that may expand to be squeezably secured to the desired digit. Also, as with the first end 14 , the second end may have other configurations, as appropriate, For example, the second end 22 may not be formed as a complete circle so long as it does not slip easily from the digit to which it is secured. Preferably, the second end 22 includes a tab 24 used to pull the attachment 10 from a person's digit after use.
[0014] As can be readily appreciated from these figures, when the disclosed attachment 10 is used to secure a pet training device 12 to the digit of a person's hand, the training device 12 does not need to be grasped in hand, yet is always ready to be grasped, and may be activated virtually instantaneously with the very act of grasping the device 12 by depressing an activation surface 30 on the device 12 . To facilitate this feature, the attachment 10 may include a flexible neck 20 between the anchor 18 and the second end 22 that tapers in the direction of the first end 14 . The flexible neck 20 may serve two related functions. First, the taper of the neck 20 immediately adjacent the anchor 18 secures the opening 32 to the flexible neck 20 . Also, the flexibility of the neck 20 is such that the neck 20 permits the device 12 to be displaced in hand from a relaxed position as shown by the solid outline of FIG. 1B to a displaced position as shown by the phantom outline in this figure. In this case, the relaxed position refers to that to which the flexible neck region will cause the device 12 to return when displaced. In other words, the neck 20 acts to ensure that, whatever the angle or amount of deflection of the pet training device 12 , due to for example, holding a ball to be thrown, the pet training device afterward returns to its relaxed position where not only will the pet training device be ready to be grasped by simply closing the hand to which it is attached, but the activation surface 30 is also ready to be activated merely upon grasping the device 12 .
[0015] Another feature of the attachment 10 is that its relative orientation with the device 12 may be reversed, and it will not lose its functionality. For example, in FIG. 1B the attachment 10 is shown in a configuration where the device 12 is secured to the digit that is used to activate the device by depressing the activation surface 30 . It is possible, however, to detach the device 12 from the attachment 10 , turn the device 12 over and reattach it so that the activation surface is facing away from the digit to which the device 12 is attached. In that case, when grasped, the activation surface may be activated using another digit, e.g. an index finger where the device 12 is attached to the thumb. This reversal may even be accomplished while the attachment is continuously secured to the thumb (or another digit) for long training periods where one digit becomes fatigued or sore after continual use, or to avoid repetitive stress injuries by a professional dog trainer, for example.
[0016] In one preferred embodiment, the attachment 10 is approximately 2 inches in length and is advantageously integrally formed of the same flexible material. The inventors have discovered that Kraton G7720 G1 is a suitable material for the disclosed attachment, and preferably has a durometer of approximately 57. In this context, the term “approximately” means within 10%, although more preferably the durometer of the material used is within 5% of this number and even more preferably 2%. The inventors discovered that these disclosed ranges provide an appropriate balance between sufficient flexibility to securely extend over the digit of a person's hand, and the resiliency to both maintain a proper relative orientation of an attached pet training device 12 and to return a device 12 to that orientation from a deflected position. It should be understood that the dimensions suitable for the attachment 10 will vary based on factors such as the size of a person's fingers for which it is designed, the type and weight of pet training device to which it is intended to be attached, the size of any opening 32 on that device, etc.
[0017] FIGS. 2A and 2B show another exemplary attachment 40 . The attachment 40 preferably includes a member 50 , which like the second member 22 of the attachment 10 , is used to secure the attachment 40 to the digit of a person's hand. The attachment 40 preferably includes first and second flexible attachment rings 42 and 44 , respectively, used to squeezably secure the attachment 40 to either end of a pet training device 60 having an activation surface 62 . The member 50 also includes a tab 52 used to quickly remove the attachment 40 from a digit to which it is attached. The attachment 40 is also preferably integrally formed of the same flexible material, such as Kraton G7720 G1 with a durometer of approximately 57.
[0018] Preferably the attachment rings 42 and 44 are not spaced an equal distance to either side of the member 50 . This advantageously causes the aperture of the member 50 to tilt at an angle relative to the actuation surface of the pet training device 50 to which it is attached, so that a digit inserted therein is directed downwardly towards the actuation surface. The present inventors have discovered that an appropriate angle is approximately 45-degrees, and that the attachment rings 42 and 44 be spaced apart from the member 50 by respective distances equal to or exceeding a 3:1 ratio and more preferably a 4:1 ratio through opposed flexible neck regions 46 and 48 .
[0019] The attachment 40 includes the functional advantages of the device 10 as previously described. More specifically, when attached to the digit of a person's hand, such as a thumb, it may be displaced to, for example throw a ball, and yet return to a relaxed position where the device 60 is ready to be activated immediately upon being grasped by a person's hand.
[0020] The terms and expressions that have been employed in the forgoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalence of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.
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An attachment selectively attachable to a pet training device that emits signal upon actuation by the hand that grasps the pet training device. The attachment includes an aperture for selectively securing the attachment to a hand and at least one connector for securing the attachment to the pet training device.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 14/331,456 filed Jul. 15, 2014, which is a continuation in part of U.S. application Ser. No. 13/626,057 filed Sep. 25, 2012, and further claims priority to U.S. Provisional Application No. 61/846,270 filed on Jul. 15, 2013.
BACKGROUND
This disclosure generally relates to method and device for creating a linked item. More particularly, this disclosure relates to a method and device for creating a linked wearable item from elastic bands.
Kits that include materials for making a uniquely colored bracelet or necklace have always enjoyed some popularity. However such kits usually just include the raw materials such as different colored threads and beads and rely on the individual's skill and talent to construct a usable and desirable item. Accordingly there is a need and desire for a kit that provides not only the materials for creating a unique wearable item, but also that simplifies construction to make it easy for people of many skill and artistic levels to successfully create a desirable and durable wearable item.
SUMMARY
A Brunnian link is a link formed from a closed loop doubled over itself to capture another closed loop to form a chain. Elastic bands can be utilized to form such links in a desired manner. The example kit and device provides for creation of Brunnian and other linked articles. Moreover, the example kit provides for the successful creation of unique wearable articles using Brunnian and other link assembly techniques.
The example kit includes a template for mounting an initial band and a hook utilized for attaching additional bands to the initial bands placed on the template. The template includes pins that hold the initial band in place while additional bands are linked onto each other. The kit further includes a clip utilized to attach ends once the desired length is formed.
These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 perspective view of an example kit for creating a linked article.
FIG. 2 is schematic view of link article.
FIG. 3 is a schematic view of a series of a series of Brunnian links.
FIG. 4 is a side view of an example template.
FIG. 5 is an end view of the example template.
FIG. 6 is a top view of the example template.
FIG. 7 is a plan view of an example clip for securing loose ends of a Brunnian linked article.
FIG. 8 is perspective view illustrating elastic bands secured with the example clip.
FIGS. 9A-9M are views of an example method of creating a linked article using the example template and kit.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , an example kit is indicated at 10 for creating linked items such as bracelets, necklaces and other wearable or decorative article as generally indicated in FIG. 2 . The example kit 10 includes a template 12 , a clip 16 and a hook 14 . The example kit 10 also includes a number of elastic members 18 that are used with the kit 10 to form links for the resulting wearable article. The elastic members 18 are consumed as articles are fabricated, and are replaced and replenished with additional elastic members. Moreover, the example elastic members 18 are of a size corresponding with the example template 12 . Further, although a single clip 16 is illustrated, the example kit 10 will include many clips 16 to provide for the fabrication of many articles 26 .
Referring to FIG. 3 , a Brunnian link 20 is formed from a continuous looped structure without forming an actual knot. Several links 20 are formed in a chain to form a circular structure. Ends 22 of each elastic member 18 are secured and a durable wearable article is created. In this example three links 20 are shown forming a single chain. Each link 20 is formed by capturing the ends 22 of one loop structure with a mid portion 24 of another loop structure in series. Each link 20 depends on the previous and subsequent links 20 to maintain the desired shape and integrity. Removing one link 20 results in all of the links becoming loose from each other.
Referring to FIGS. 4, 5 and 6 , the example template 12 includes two posts 28 A, 28 B spaced a distance 30 apart from each other. Each of the pins 28 A, 28 B includes a first arm 32 a - b and second arm 34 a - b supported on a base 36 . The arms 32 a - b , 34 a - b defines an access slot 38 that extends across both of the posts 28 A, 28 B. The base 36 includes a link opening 40 for completed links of a linked article during fabrication. Each of the first and second arms 32 a - b , 34 a - b include upper and lower tabs 42 that maintain a linked article within a center section 44 .
Referring to FIGS. 7 and 8 , the example clip 16 is generally C-shaped with inwardly facing ends 48 . The inwardly facing ends 48 point inwardly to an open space 50 where parts of the elastic members are kept. The inwardly facing ends 48 prevent ends 22 from sliding out from the inner area 50 off of the clip 16 .
Referring to FIGS. 9A-M , the example template 12 is utilized for the formation of a linked article. As appreciated, elastic bands 18 can be difficult to manipulate and hold during the construction of a desired article. The example template 12 provides for holding of an initial number of links 20 and subsequent connection of each link in the linked article. The template 12 includes the first and second posts 28 A, 28 B along with the access slot 38 across both of the posts 28 A-B. The specific linked configuration can be a simple Brunnian link, but may also be more complex and intricate link structures such as a fishbone type link structure. The template 12 includes the link opening 40 to facilitate the fishbone link structure where the linked article grows and extends from the template 12 through the link opening 40 .
The Figures illustrate formation of a fishbone linked structure utilizing the example template 12 . The initial step illustrated in FIG. 9A includes assembling a first elastic band 18 A by crossing over itself to form a FIG. 8 pattern across the posts 28 A-B. A second elastic band 18 B and third elastic band 18 C is then assembled over the first elastic band 18 A without crossing over as is shown in FIG. 9B . Three elastic bands are therefore supported across the posts 28 A-B with the first band 18 A on the bottom below the second and third elastic bands 18 B, 18 C.
Utilizing the hook tool 14 , the bottom, lower most, or first elastic band 18 A is pulled off of the posts 28 A-B and looped over the second and third elastic bands 18 B, 18 C as is shown in FIGS. 9C and 9D . The first elastic band 18 A is positioned to loop around each of the second and third elastic bands 18 B, 18 C and is not supported directly by the posts 28 A-B.
An additional elastic band 18 D is then added above the second and third elastic bands 18 B, 18 C such that the second elastic band 18 B is now the lower most elastic band as is shown in FIG. 9E . The lower most elastic band 18 B is then grasped with the hook tool 14 ( FIG. 9F ) by extending the hook tool 14 into the access slot 38 and grasping ends of the elastic band in sequence, pulling the ends away from the corresponding post ( FIG. 9G ) and looping each end over onto the and around the other links supported between the first and second posts as is shown in FIG. 9H .
An additional link is added above the two remaining links 18 C, 18 D across the two posts 28 A-B as is shown in FIG. 9I and the process shown in FIGS. 9F through 9H is repeated with additional links to grow the length of the linked structure as is shown in FIGS. 9J and 9K until a desire length or number of links are connected to each other as is illustrated in FIG. 9L .
Once the desired length is achieved, as the example in FIG. 9L illustrates a clip 16 is attached to the end elastic link. The remaining links on the posts 28 A-B can be removed and attached to the clip 16 to form the completed linked article as is shown in FIG. 9M . As appreciated although the ends are connected to form the example linked article. The linked article may have terminal ends that are separately terminated to provide a length of a linked article.
Accordingly, the example kit and method provide for the creation of many different combinations and configurations of linked structures and articles for the creation of bracelets, necklaces, and other wearable items. Moreover, the example kit is expandable to further create and expand the capabilities of potential linked structures and articles. Further, the example kit provides for the creation of such links and items in an easy manner allowing persons of varying skill levels to be successful in creating unique wearable items.
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this invention.
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A disclosed device for creating an item consisting of a series of links includes at least two posts spaced part from each other in a first direction with each of the posts including a first arm and a second arm and an access slot.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/692,153 filed Jun. 20, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates in general to conducting coil tubing operations in wellbores and more specifically to maintaining depth control during the operations.
BACKGROUND
[0003] In a cased oil or gas well, the hydrocarbon in the formation can be accessed by perforating the casing with a high-energy shape charge or by abrasively cutting holes or slots in the casing with a jetting tool. In the latter application, slurry is pumped down a tubular and through a small jetting nozzle. This abrasive mixture exits the jetting tool at a high velocity, impinges on the casing wall and abrades or cuts holes in the casing. Abrading holes in casing is performed by technologies such as the Abrasijet™ tool introduced by Schlumberger.
[0004] Conventional jetting assemblies are lowered on drillpipe. Some drillpipe conveyed jetting assemblies include slip-type mechanisms to limit the vibration of the bottom hole assembly (BHA) in the wellbore, however, these slips are not designed to stop axial movement of the BHA in the wellbore.
[0005] Recently, jetting tools have been attached to coiled tubing and this has introduced new challenges. The primary issue facing coiled tubing deployed jetting is depth control. Knowing exactly where the BHA is during a job and maintaining the BHA in a desired location during operations is difficult. The coiled tubing length is susceptible to axial compression and tension forces, internal pressure, flow rate down the tubing or annulus, high temperatures, coiled tubing friction with casing wall, etc. During jet cutting and other wellbore operations, many of the forces mentioned act on the tubing and BHA. The result is that the overall length of the coiled tubing changes and the tool moves during the operation. Movement of the jetting tool during cutting operations results in slots or incomplete cutting of the casing. In a worst-case scenario, the jetting tool can move as much as ten ft (3 m), which can be enough to jet holes into the wrong formation behind the reservoir.
[0006] Conventional techniques for maintaining depth control of coiled tubing include devices that monitor how much tubing has been fed into the wellbore, however these techniques do not provide the extent of buckling, stretch, etc. Enhancements to these methods include the step of using forward modeling or knowledge of the tubing properties to predict this buckling, stretch, etc.
[0007] Depth control during abrasion cutting has conventionally included the step of using a mechanical casing collet locator (CCL) that activates a hammer to “strike” the coiled tubing each time the CCL crosses a casing collar. The sound of the hammer striking the coil can (sometimes) be picked up by listening to the coil at the surface.
[0008] Therefore, there is a desire to provide methods and systems for controlling the depth of a coiled tubing conveyed tool during wellbore operations.
SUMMARY OF THE INVENTION
[0009] Accordingly, depth control systems and methods for maintaining a tubing conveyed tool at a desired depth in a cased wellbore during wellbore operations is provided. An embodiment of a depth control system for maintaining a tubing conveyed tool in a desired location in a cased wellbore during wellbore operations performed with the tool includes a bottom hole assembly carried by a tubing, the bottom hole assembly including a tool and an anchoring device.
[0010] An embodiment of a method for maintaining a tool at a desired depth in a cased wellbore while performing wellbore operations with the tool includes the steps of conveying a tool and an anchoring device on a tubing to a desired depth in a wellbore having a casing, operating the tool to perform a wellbore operation and actuating the anchoring device to engage the casing and maintain the tool at the desired depth.
[0011] The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 is a perspective view of an embodiment of the depth control system of the present invention;
[0014] FIG. 2A is perspective view of an anchoring device of the present invention in a retracted position;
[0015] FIG. 2B is a perspective view of the anchoring device of FIG. 2A in the extended or engaged position; and
[0016] FIG. 3 is a perspective view of another embodiment of an anchoring device of the present invention.
DETAILED DESCRIPTION
[0017] Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
[0018] As used herein, the terms “up” and “down”; “upper” and “lower”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements of the embodiments of the invention. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth of the well being the lowest point.
[0019] The present invention relates to controlling and maintaining the depth of a tubing conveyed tool during wellbore operations. The present invention is described herein in relation to jet cutting and stimulation operations, however, it should be recognized that the depth control systems and methods of the present invention may be utilized in conjunction with other wellbore operations. It should further be noted, that although the invention is particularly suited for coiled tubing operations, the system and method may be utilized with other tubulars including drillpipe.
[0020] FIG. 1 is a perspective view of an embodiment of the depth control system of the present invention, generally denoted by the numeral 10 . Depth control system 10 includes a tool 12 and anchoring mechanism 14 conveyed by tubing 16 into a wellbore 18 having casing 20 . Tool 12 and anchoring mechanism 14 are referred to herein as the bottom hole assembly (BHA) and generally designated by the numeral 5 . Depth control system 10 may further include a depth management system 22 .
[0021] A first step in conducting wellbore operations is to position tool 12 at the desired depth in wellbore 18 . In the illustrated embodiment, it is desired to cut hole 24 proximate formation 26 and then to stimulate formation 26 for production or injection. Depth management system 22 is utilized to accurately convey tool 12 via tubing 16 to the desired depth at formation 26 by identifying the location of BHA 5 in wellbore 18 . In one embodiment of the present invention, depth management system 22 includes one or more sensors 28 carried by BHA 5 operationally connected to a surface unit 30 for displaying depth readings of BHA 5 . Sensor 28 may be connected to surface unit 30 via a cable 32 , such as but not limited to optical fibers, monocable or heptacable. Sensor 28 may be operationally connected to surface unit 30 via wireless telemetry. Sensors 28 may further be adapted to measure and provide additional data, including pressure, temperature and BHA 5 telemetry information such as axial and azimuthal data to surface unit 30 . It should further be noted that surface unit 30 may be in operational connection with tool 12 and/or anchoring mechanism 14 to provide electronic control of their operation.
[0022] Anchoring mechanism 14 is adapted to engage casing 20 so as to limit or prevent longitudinal movement of BHA 5 in wellbore 18 when engaged. Examples of anchoring mechanisms 14 include (i) pressure, flow, or mechanically activated gripping slips that engage casing 20 during tool 12 operation or (ii) spring, pressure, flow or mechanically activated drag blocks that simply use friction to hold tool 12 in place during operation of tool 12 .
[0023] Referring now to FIGS. 2A and 2B , anchoring mechanism 14 is illustrated as a button type slip. Anchoring mechanism 14 includes a button slip 34 moveable between a retracted position shown in FIG. 2A and an extended or engaged position, shown in FIG. 2B . Anchoring mechanism 14 may further including shoulders 36 extending from button slips 34 and a matable lip 38 to limit the extension of button slip 34 .
[0024] Operation of button slips 14 is further described with reference to FIGS. 1, 2A and 2 B. When wellbore operations are commenced, fluid, such as an abrasive fluid, is pumped through the internal bore 40 of coiled tubing 16 , tool 12 and anchoring mechanism 14 . As the pressure increases in bore 40 over the pressure in the annulus 42 between BHA 5 and casing 20 , button slip 34 extends outward from BHA 5 and engages casing 20 . When the wellbore operations cease and the pressure in bore 40 equalizes with pressure in annulus 42 , button slip 34 is biased back to the retracted position of FIG. 2A .
[0025] FIG. 3 is a perspective view of another embodiment of anchoring device 14 . In this embodiment, anchoring device 14 includes a drag block 44 . Drag block 44 is extended from anchoring device 14 and engages casing 20 . Drag block 44 utilizes friction to minimize the movement of BHA 5 . Drag block 44 may be actuated via pressure in bore 40 and/or by biasing means such as, but not limited to, springs 46 .
[0026] Depth control of BHA 5 may further include the step of adjusting or controlling the location of tool 12 to enable adjustment of its axial location or its azimuthal location. As previously indicated, depth management system 22 may provide BHA 5 telemetry information and operator control of tool 12 operation. In the case of adjusting the axial location of a jet tool 12 , an injector control may be utilized. In the case of adjusting the azimuthal location, a gravity-sensor, such as a hanging weight 48 may be added to BHA 5 and the jets 50 oriented with respect to hanging weight 48 . A combination of these techniques could be used to create spirals, ovals, etc in casing 20 .
[0027] Downhole measurement data can be obtained and transmitted during the stimulation via depth management system 22 using optical telemetry, wireless telemetry and telemetry along a cable. A preferred embodiment is optical telemetry, in which case optical devices exist to transmit temperature and pressure. Downhole pressure can also be used to derive flow-rate, foam-quality and viscosity or dedicated sensors can be used.
[0028] In an embodiment of the present invention, formation 26 is stimulated utilizing hydraulic fracturing via tool 12 . Measured data, via sensors 28 , is pressure and the method includes the step of monitoring the downhole pressure to give an indication of at least one of: screen-out, radial fracture extent, vertical fracture extent, and perforation friction. The measured data can be transmitted up cable 32 and plotted on a chart of log-time versus log-pressure. If the slope of this approaches one then this is indicative of a screen-out, wherein the formation cannot absorb any more proppant. In such a case, the pumping operation needs to be quickly switched to stop wellbore 18 from completely filling with sand. Having a downhole measurement gives many minutes of advance warning. Other slopes on the log/log plot are indicative of either the fracture growing radially or vertically.
[0029] During wellbore operations such as jetting, downhole measurement data can be transmitted to optimize the procedure, e.g., adjusting the flow rate to maintain a constant pressure drop across jets 50 in cutting operations. As the abrasive cutting material passes through jets 50 , the jets will lower the impinging pressure on casing 20 . By monitoring this, the flow-rate can be increased in accordance so as to maintain a constant pressure on the casing surface, resulting in a cleaner and faster cut hole 24 .
[0030] The present invention covers both pumping down a tubular and into annulus 42 between tubular 16 and casing 20 . For example, coiled tubing 16 can be introduced into wellbore 18 and stimulation fluid is pumped down annulus 42 .
[0031] Alternatively, the stimulation fluid can be pumped down coiled tubing 16 . In older wells the stimulation fluid is forced into jetted holes 24 via a zonal isolation apparatus (not shown) straddling those holes. Typically such apparatus include cups and inflatable packers.
[0032] Once holes 24 have been jetted and reservoir formation 26 stimulated, the reservoir will be allowed to flow-back, sometimes kicked off with nitrogen to initiate the flow. In the case of hydraulic fracturing, this initiation can allow a significant amount of sand to return into the well-bore. This sand coming at high-speed through the jetted holes will then itself act as a sort of abrasive jet and can cut holes in the tubular used to convey the bottom hole assembly. Consequently, it is a preferred feature of this method to pull the tubular up above the incoming fluid, so as to avoid abrading that tubular.
[0033] From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a depth control system and method for maintaining and controlling a tubing conveyed tool during wellbore operations that is novel has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow.
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A depth control system for maintaining a tubing conveyed tool in a desired location in a cased wellbore during wellbore operations performed with the tool includes a bottom hole assembly carried by a tubing, the bottom hole assembly including a tool and an anchoring device. A method for maintaining a tool at a desired depth in a cased wellbore while performing wellbore operations with the tool includes the steps of conveying a tool and an anchoring device on a tubing to a desired depth in a wellbore having a casing, operating the tool to perform a wellbore operation and actuating the anchoring device to engage the casing and maintain the tool at the desired depth.
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BACKGROUND INFORMATION
[0001] German Patent Application No. DE 41 21 310 describes a fuel injector which has a valve-seat member, on which a fixed valve seat is formed. A valve-closure member, which is axially movable in the injector, cooperates with this valve seat formed in the valve-seat member. Adjoining the valve-seat member in the downstream direction is a flat jet-directional plate in which, facing the valve seat, an H-shaped depression is provided as an intake region. Adjoining the H-shaped intake region in the downstream direction are four spray-discharge orifices, so that a fuel to be discharged can be distributed over the intake region toward the spray-discharge orifices. In so doing, the flow geometry in the jet-directional plate is not to be influenced by the valve-seat member. Rather, a flow passage is implemented downstream of the valve seat in the valve-seat member so far that the valve-seat member has no influence on the opening geometry of the jet-directional plate.
SUMMARY OF THE INVENTION
[0002] The method of the present invention for producing and securing an apertured disk has the advantage that particularly small apertured-disk thicknesses are easily attainable. Since according to the present invention, the spray-discharge openings are introduced in the thickness-reduced middle region of the apertured disk, it is possible to form a plurality of spray-discharge openings having very small spray-orifice diameters in the apertured disk, while maintaining known and customary ratios of length to diameter of each individual spray-discharge opening. Consequently, an apertured disk produced according to the present invention and mounted on a fuel injector guarantees the finest uniform atomization of the fuel, a particularly high atomization quality and a jet formation adapted to the specific requirements being attained.
[0003] The impressing or embossing process employed for reducing the thickness of the apertured disk may advantageously be used with low expenditure for forming apertured disks in very large quantities.
[0004] In particularly advantageous manner, the apertured disk produced according to the present invention is mounted in such a way on a fuel injector that the apertured disk, disposed downstream of a valve seat, has an opening geometry for a complete axial passage of the fuel, the opening geometry being bounded by a valve-seat member encompassing the fixed valve seat. The valve-seat member therefore already assumes the function of influencing the flow in the apertured disk. An S-twist is especially advantageously attained in the flow for improving the fuel atomization, since a lower end face of the valve-seat member covers the spray-discharge openings in the apertured disk.
[0005] The S-twist in the flow, attained by the geometrical arrangement of the valve-seat member and the apertured disk, allows the formation of bizarre jet forms having high atomization quality. The apertured disks, in conjunction with suitably implemented valve-seat members for single-jet, dual-jet and multi-jet sprays, permit jet cross-sections in countless variants. Using such a fuel injector, it is possible to reduce the exhaust emissions of the internal combustion engine, and fuel consumption is able to be reduced as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a partially depicted injector having an apertured disk downstream of the valve-seat member.
[0007] FIG. 2 shows an enlarged representation of the valve-seat part made up of the valve-seat member and apertured disk.
[0008] FIG. 3 shows schematically the method step of impressing or embossing.
DETAILED DESCRIPTION
[0009] FIG. 1 partially shows a valve in the form of an injector for fuel injection systems of mixture-compressing internal combustion engines having externally supplied ignition. The injector has a tubular valve-seat support 1 , in which a longitudinal opening 3 is formed concentrically with respect to a longitudinal valve axis 2 . Situated in longitudinal opening 3 is a, for example, tubular valve needle 5 , which is securely joined at its downstream end 6 to a, for instance, spherical valve closure member 7 , at whose periphery, five flattenings 8 , for example, are provided for the fuel to flow past.
[0010] The fuel injector is actuated in a known manner, e.g. electromagnetically. A schematically indicated electromagnetic circuit having a solenoid coil 10 , an armature 11 and a core 12 is used for axially moving valve needle 5 and, as such, for opening the injector against the spring force of a restoring spring (not shown) and for closing the injector. Armature 11 is connected to the end of valve needle 5 facing away from valve-closure member 7 by, for example, a welded seam formed by a laser, and is aligned with core 12 .
[0011] A guide opening 15 of a valve-seat member 16 , which is sealingly mounted by welding into the downstream end of valve-seat support 1 facing away from core 12 , in longitudinal opening 3 running concentrically with respect to longitudinal valve axis 2 , is used for guiding valve-closure member 7 during the axial movement. At its lower end face 17 facing away from valve-closure member 7 , valve-seat member 16 is concentrically and securely joined to a, for instance, cup-shaped apertured disk 20 . Apertured disk 20 is implemented with a base part 24 and a retention rim 26 . Retention rim 26 extends in the axial direction facing away from valve-seat member 16 , and is bent outwardly in conical fashion up to its end. Valve-seat member 16 and apertured disk 20 are joined, e.g., by a first peripheral and impervious welded seam 25 , formed by a laser, in an outer annular region of base part 24 . For reasons of fatigue strength of the injector, apertured disk 20 should have a thickness of at least 0.2 mm in this securing region. In the region of retention rim 26 , apertured disk 20 is moreover joined to the wall of longitudinal opening 3 in valve-seat support 1 , e.g., by a peripheral and impervious second welded seam 30 .
[0012] According to the present invention, a middle region 33 of base part 24 of apertured disk 20 is reduced in thickness compared to the outer annular region of base part 24 and compared to retention rim 26 . At least one, however, ideally a plurality of spray-discharge openings 34 , is introduced in this middle region 33 . In this context, spray-discharge openings 34 are advantageously located in the outer edge region of thickness-reduced middle region 33 , which, for example, is circular, so that lower end face 17 of valve-seat member 16 covers spray-discharge openings 34 , which means downstream of valve seat 29 between an outlet orifice 31 in valve-seat member 16 and spray-discharge openings 34 in apertured disk 20 , in each case the fuel flow takes an S-shaped course.
[0013] The insertion depth of the valve-seat part, made up of valve-seat member 16 and cup-shaped apertured disk 20 , into longitudinal opening 3 determines the size of the lift of valve needle 5 , since the one end position of valve needle 5 when solenoid coil 10 is not energized is determined by the contact of valve-closure member 7 against valve seat 29 of valve-seat member 16 , valve seat 29 tapering conically downstream. When solenoid coil 10 is energized, the other end position of valve needle 5 is determined, e.g., by the seating of armature 11 on core 12 . Therefore, the path between these two end positions of valve needle 5 represents the lift. Valve-closure member 7 cooperates with valve seat 29 .
[0014] Valve-seat member 16 is formed with its lower outlet orifice 31 in such a way that lower end face 17 of valve-seat member 16 partially forms an upper covering of an intake region 40 of apertured disk 20 , formed by the depression in middle region 33 of apertured disk 20 , and thus determines the entry area of fuel into apertured disk 20 . In the exemplary embodiment shown in FIG. 1 , outlet orifice 31 has a smaller diameter than the diameter of an imaginary circle on which spray-discharge openings 34 of apertured disk 20 are situated. Because of the radial displacement of spray-discharge openings 34 with respect to outlet orifice 31 , an S-shaped flow pattern of the medium, here the fuel, results toward each individual spray-discharge opening 34 , which is indicated clearly in FIG. 2 by arrows 36 .
[0015] The so-called S-twist within apertured disk 20 having several sharp reroutings of the flow impresses a strong, atomization-promoting turbulence on the flow. The velocity gradient transversly to the flow is thereby particularly strongly pronounced. It is an expression for the change in velocity transversely to the flow, the velocity in the middle of the flow being perceptibly greater than in the vicinity of the walls. The increased shear stresses in the fluid resulting from the velocity differences promote the disintegration into fine droplets near spray-discharge openings 34 . Since because of the impressed radial component, the flow in the outlet is detached on one side, it experiences no calming because there is a lack of contour guidance. The fluid exhibits an especially high velocity at the detached side. The atomization-promoting turbulences and shear stresses are therefore not dissipated in the outlet. Due to the S-twist, a high-frequency turbulence is generated in the fluid, this turbulence causing the jet to disintegrate into suitably fine droplets immediately after exiting apertured disk 20 .
[0016] FIG. 2 shows an enlarged representation of the valve part formed by valve-seat member 16 and apertured disk 20 , in order to clearly indicate the S-shaped flow pattern, denoted by arrows 36 , toward each spray-discharge opening 34 . FIG. 3 shows schematically the impression method step.
[0017] In a first method step, not shown, a flat metallic sheet 20 ′ having a constant thickness is made available. This sheet 20 ′ has a thickness of approximately 0 . 2 mm, for example, which is retained outside of region 33 even after application of the method steps according to the present invention. For instance, sheet 20 ′ is a stainless steel material such as 1.4404, 1.4301 or SUS304, having a tensile strength of 500 to 700 N/mm 2 and an original hardness of 160±15 HV. For reasons of long-term endurance of the fuel injector, apertured disk 20 should have a minimum thickness of 0.2 mm at least in its annular region of base part 24 , in which apertured disk 20 is secured to valve-seat member 16 by welded seam 25 . In order to optimally adhere to the ratio of length to diameter of each individual spray-discharge opening 34 from the standpoint of fluid mechanics, given the predefined minimum thickness, the spray-orifice diameters are likewise largely predefined with a minimum value. If, for reasons of improved atomization and spray conditioning, a plurality of spray-discharge openings 34 having very small spray-orifice diameters, e.g. less than 0.2 mm, is now to be formed in apertured disk 20 , it is advantageous in region 33 of spray-discharge openings 34 , to reduce the thickness of sheet 20 ′, from which the later apertured disk 20 is formed.
[0018] In a further method step, thickness is reduced by impressing, a depression 40 ′ thereby being formed in sheet 20 ′ ( FIG. 3 ). This depression 40 ′ has, for example, a frustoconically inclined or cylindrical limiting wall. Given an original thickness of sheet 20 ′ of 0.12 mm to 0.25 mm, the thickness reduction in region 33 , accomplished by impressing, may amount to approximately 0.05 mm to 0.1 mm. A stamping tool 41 is indicated symbolically in FIG. 3 . During the impressing process, a plastic deformation is carried out and material of sheet 20 ′ is displaced and piled up a little bit on the contact side of stamping tool 41 around depression 40 ′. This displaced material can easily be distributed in a rolling process. By this rolling or method also called “stamping”, the mound around impressed region 33 is uniformly distributed radially outwardly, resulting in a negligible increase in thickness in the region immediately outside of impressed region 33 .
[0019] As an alternative to impressing, the thickness of sheet 20 ′ may also be reduced in region 33 , in which spray-discharge openings 34 are located, by so-called embossing. It is a stamping-bending operation, similar to deep drawing, as a further possibility for cold-working a metal. Embossing is suitable for forming intake region 40 of apertured disk 20 in particular when the hardness of the material to be deformed is greater or considerably greater than 160 HV. During the embossing process, material is pushed out on the bottom side of sheet 20 ′ facing away from the contact side of embossing tool 41 ′. This protruding material is subsequently removed again by grinding, for example, so that the bottom side of sheet 20 ′, i.e., of apertured disk 20 , is even.
[0020] After thickness has been reduced by impressing or embossing, in a further method step, the at least one spray-discharge opening 34 is introduced in region 33 of sheet 20 ′. Sheet 20 ′ is thereupon finish-machined until apertured disk 20 is obtained with its predefined outside dimensions. However, apertured disk 20 may also already be provided with the desired outside dimensions prior to introducing spray-discharge openings 34 by separating it from sheet 20 ′, for example, by punching out, cutting out, or in a similar manner. The at least one spray-discharge opening 34 is introduced by punching, eroding or laser drilling.
[0021] As already described in detail above, in conclusion, apertured disk 20 is secured according to the present invention in a manner that the flow approaches spray-discharge openings 34 in an S-shape, since in the mounted state of apertured disk 20 , material of valve-seat member 16 overlaps spray-discharge openings 34 radially inwardly.
[0022] FIG. 1 shows, by way of example, a cup-shaped apertured disk 20 , mounted on a fuel injector, which, because of its retention rim 26 , is able to be mounted in a particularly secure and reliable manner. However, the method steps of the present invention for producing an apertured disk 20 are by no means limited to such geometrical designs of apertured disks 20 . Rather, apertured disks 20 which are completely flat or bent differently are also able to be reduced in thickness according to the present invention in a region 33 .
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The method for producing and securing an apertured disk for a fuel injector is distinguished by the use of the following method steps: a) making available a flat, metallic sheet having a constant thickness, b) reducing the thickness in one region of the sheet by impressing or embossing, c) introducing at least one spray-discharge opening in the region having reduced thickness, d) machining the sheet until an apertured disk having predefined outside dimensions is attained, and e) securing the apertured disk on a valve-seat member of the fuel injector in such a way that a lower end face of the valve-seat member overlaps an intake region of the apertured disk produced by the thickness reduction, such that the at least one spray-discharge opening is covered.
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This application is the U.S. national-phase application of PCT International application Ser. No. PCT/EP93/01569.
BACKGROUND OF THE INVENTION
The present invention relates to a circuit for monitoring an inductive circuit which is formed as part of a signal-processing circuit or as an additional element and which is connected, through a high-ohmic input circuit or filter circuit, to the signal-processing circuit. The monitoring initiates a test cycle to determine the inductance of the circuit to be monitored, including the filter circuit, if predetermined conditions apply and/or in predetermined intervals.
A monitoring circuit of this type is disclosed in EP 0 358 887 A1. In this monitoring circuit, the duration of a test signal passing through the inductive circuit to be monitored is monitored and evaluated with respect to proper duration by means of a time-difference measuring apparatus. To this end, the time difference of the duration of a signal, which is conducted to the time-difference measuring apparatus through the inductance and a time element, is compared to the signal which is conducted directly through an equal time element to the measuring apparatus.
Circuits of this type are particularly suitable to detect short circuits in the inductive transducer of a wheel sensor. If the short circuit is in the line leading to the transducer, in its input circuit or filter circuit, the short circuit is likewise detected in the monitoring operation. A line interruption is also detected. Sensors of this type, which are required in anti-lock systems or traction slip control systems of automotive vehicles, for example, are safety-critical component parts which should be checked permanently for operability, short circuits or line interruptions. In a low-ohmic input circuit or filter circuit, a short circuit may be detected relatively easily by determining the ohmic resistance between an output of the filter circuit and ground. For a high-ohmic filter circuit, such an arrangement is not suitable in practical operations because the ohmic internal resistance of the inductive circuit is low compared to the resistors in the circuit or input circuit. Therefore, the voltage drop, which may be measured at the output of the filter circuit when a current is applied, will be changed by a short circuit only to such a minor extent that reliable evaluation of the measurement results is not possible.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a circuit for monitoring an inductive circuit which has a simple design, does not require additional terminals and permits detecting short circuits or line interruptions in a reliable manner, even if the inductive circuit is connected through a high-ohmic filter circuit or input circuit.
This object can be achieved by circuitry having the special features that, at the beginning of the test cycle, one of the two outputs of the filter circuit is connected to ground, while the second output is connected to a voltage source for a predetermined period, and the inductance is determined from the potential variation at a second output of the filter circuit.
It is expedient that the predetermined period corresponds at least to the transient time of the circuit to be monitored, including the filter circuit. Upon lapse of the predetermined time period and disconnection of the voltage source, the potential variation at the second output is evaluated to determine the inductance.
Also, symmetrically arranged filter circuits may be used, each of which has one high-ohmic series resistance in the lines leading from the inductive circuit to the signal-processing circuit, one capacitor interconnecting both outputs of the filter circuit, and one input capacitor which connects one of the outputs of the inductive circuit or one of the inputs of the filter circuit to ground.
To simplify the analysis of the signal, a d.c. voltage potential may be set for such a filter circuit by a voltage divider which is connected to a source of d.c. voltage on one side and to ground on the other side. When a line interruption occurs, an elevated potential difference results at the two inputs of the signal-processing circuit. However, the circuitry according to the present invention also allows detecting a line interruption by the consequent change in the inductance of the circuit to be monitored.
In another embodiment of the present invention, the monitoring circuit discharges the capacitor, which interconnects both outputs, instantaneously after or simultaneously with the disconnection of the voltage source by grounding the second output for a short interval. The analysis of the potential variation during the test cycle to determine the inductance of the inductive circuit is highly facilitated by this arrangement.
Further features, advantages and possible applications of the present invention will be understood from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a circuit diagram of a monitoring circuit for an inductive circuit constructed in accordance with the present invention and one embodiment of a filter circuit or input circuit between the inductive circuit and a signal-processing circuit,
FIG. 2 is a circuit diagram of a modified form of the embodiment of FIG. 1, and
FIG. 3 shows a number of waveforms useful in understanding the operation of the circuitry of the embodiment of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, an equivalent circuit 1' of an inductive transducer 1, a signal-processing circuit 2 and a high-ohmic input circuit or filter circuit 3 are shown. The signal-processing circuit 2 includes, in dashed lines, a monitoring circuit 4, being part of the circuit 2, which initiates test cycles to determine the inductance of the inductive circuit 1 and evaluates the signals obtained and applied to the input terminals C and D of the signal-processing circuit 2.
The equivalent circuit 1' of the inductive circuit 1 to be monitored is formed of the series arrangement of an ohmic resistor RS and an inductance LS. A capacitor CS is connected in parallel to this series arrangement. The inductive circuit is, for example, an inductive transducer of a wheel sensor serving to measure the rotations of a wheel. Transducers of this type include coils in which an alternating voltage is induced on rotation of the wheel, the frequency and amplitude of which indicates the rotation. The output signal of the sensor, applied to the terminals A, B, is delivered to the signal-processing circuit 2, where it is processed and evaluated, through the filter circuit 3 which usually is positioned at the end of an electrical line.
The filter circuit 3 in FIG. 1 is arranged symmetrically. One series resistor R1, R2 is inserted in each of the two supply lines, which is high-ohmic as compared to the internal resistor RS of the sensor. A capacitor C1 interconnects the two outputs C, D of the filter circuit 3. Two further capacitors C2, C3, connected to ground, are provided on the side of the filter circuit 3 connected to the sensor. The capacitors C1, C2, C3, along with the ohmic resistors of the filter circuit and the internal resistor of the inductive circuit, form a low-pass filter.
Further, the filter circuit 3 according to FIG. 1 includes a voltage divider with the resistors R3, R4. The voltage divider is connected to the positive pole of the supply voltage source V CC , on the one hand, and to ground GND, on the other hand.
The ohmic resistors R1, R2 are at least roughly identical. In the inactive condition, where no voltage is induced in the sensor 1, almost the same potential is applied to the terminals A, B, C, D, because the input terminal C, D of the signal-processing circuit 2 is high-ohmic. A line interruption in the sensor 1, or in the connecting line or in the input circuit 3 may be detected by means of the signal-processing circuit 2.
FIG. 2 serves to explain the mode of operation of the circuitry according to the present invention, illustrating the circuit in FIG. 1, in a slightly modified representation, and in which, additionally, three transistor stages 5, 6, 7 or semiconductor switches are illustrated for an understanding of the function of the test cycles. Switches 5, 6, 7 are included in the monitoring circuit 4 of FIG. 1. In the illustration of the embodiment of FIG. 2, the monitoring circuit 4 is quasi split up into an evaluating and control circuit 4' and the semiconductor switches 5, 6, 7. The outputs of the evaluating and control circuit 4' leading to the control inputs of the switches 5, 6, 7 also are shown in FIG. 2 and and are identified by CB, CC, CD. Further, identical reference numerals have been assigned to like parts and like terminals in FIGS. 1 and 2.
The mode of operation of an embodiment of the circuitry according to the present invention is explained hereinbelow with reference to FIG. 2 in conjunction with the waveform diagrams in FIG. 3.
Monitoring operations are performed whenever the ignition of the vehicle is switched on, for example. No voltage is induced in the inductive transducer, the equivalent circuit 1' of which is shown, at this point in time because the wheels are not yet moving. Practically nothing changes in this condition when the vehicle rolls slowly.
The test cycle is now started by an output signal CD of the monitoring and control circuit 4'. By means of the transistor 5, the signal CD connects the terminal D of the signal-processing circuit 2 of FIG. 1 or the filter circuit 3 to ground GND at the point in time t 0 . After a short transient time, a determined d.c. voltage potential is developed at the second terminal of the signal-processing circuit 2, i.e. at the terminal C, the magnitude of which potential is predetermined by the supply voltage V CC and by the voltage dividers R3, R4. At the point in time t 1 , a signal CB, which drives the transistor 6 and results in closing of the semiconductor switch, causes the potential at terminal C to rise to the level of the energy supply of source V CC .
The actual measuring operation, which is appropriate to determine the inductance and to detect short circuits, starts at the point in time t 2 which marks the termination of the actuating signal CB and, thus, the disconnection of the current source V CC from terminal C. The energy stored in the inductance LS in the presence of the signal CB, i.e. between the points in time t 1 and t 2 , after the switch 6 is opened, results in the current IL being continued and, thus, in influencing the potential variation at the terminal or input C. The current IL flowing through the inductive circuit may be calculated from the ohmic resistors R1, R2, RS, R3 and R4 in the static condition, that means after the switch 6 (signal CB) has been actuated and the transient processes have faded.
A preferred feature in the present embodiment of the invention is that the input C is grounded for a very short interval dt 3 after the connection between the input C and the voltage source V CC has been interrupted by way of the semiconductor switch 6. This is done by actuating the switch 7 by means of a signal CC. By this provision, the capacitor C1 is discharged very quickly to full extent. The current IL through the inductance LS remains practically constant during this short interval.
The charging of C1 dictates the potential variation at terminal C after the short interval dt 3 . Because a still higher potential is applied to point B than to point A, C2 discharges through the resistor RS of the inductive circuit as long as the potential is equal at points A and B. This discharging operation is assisted by the continuously flowing current IL, produced by the inductance LS, and by the now commencing charging current of capacitor C1. The result is that the potential at point B very quickly becomes less than the potential at point A, the charging of C1 being thereby delayed. After current IL has faded, which is produced by the energy stored in the inductance, an identical potential finally results at terminals A and B.
However, the previously described operations occur only when sensor 1 is intact. In the presence of a short circuit or a line interruption, the capacitor C1 is charged much quicker. This can be seen by observing and evaluating the potential variation at terminal C. The waveform diagrams in FIG. 3 illustrate this condition. The three top waveform diagrams show the course of the signals at the terminals CD, CB and CC. The switches, i.e. transistors 5, 6 and 7, are closed when an actuating signal "1" is applied.
The potential variation at terminal C is also shown in FIG. 3. The potential V Cstat develops after actuation of the transistor 5 or grounding of terminal D of the signal-processing circuit 2. V Ct4 refers to the potential which develops at the point in time of measurement t 4 when the sensor and the sensor connection are intact in the absence of an error. The interval T is so selected, in conformity with the inductance LS of sensor 1, that the transient process is not yet terminated upon expiry of interval T with respect to pulse dt 3 , that means at the point of time t 4 , and roughly the maximum discrepancy V of the potential at terminal C from the static potential V Cstat occurs, with the sensor intact, that means in the absence of short circuits and line interruptions. If there is a defect, charging of the capacitor C1 terminates long before at the point of time t 4 , and the potential at terminal C has risen to the value V Cstat . The dashed line of the potential variation V C in FIG. 3 illustrates the conditions in the presence of a short circuit or a line interruption.
It should be noted for the sake of completeness that a time difference (t 0 -t 1 ) between the initiation of the signals CD and CB is unnecessary, if subsequently, that means prior to the termination of the signal CB and the almost instantaneous application of the short-time signal CC, the transient process and, thus, the occurrence of static conditions is awaited.
Modifications of the described circuitry and the actuation, as compared to the embodiments shown in FIGS. 2 and 3, are possible. It is in any case essential that the energy stored in the inductance of the sensor 1 has an effect on the potential variation at an output of the filter circuit 3 or at a terminal of the signal-processing circuit 2 and is evaluated for the monitoring operation.
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A circuit to monitor a short circuit (or a line interruption) in an inductive circuit which is connected to a signal-processing circuit through a high-ohmic filter circuit. The monitoring circuit is formed as a component part of or as an additional element to the signal-processing circuit and initiates a test cycle to determine the inductance of the circuit to be monitored when, for example, the ignition of an automotive vehicle is turned on when the inductive circuit is used in the circuitry for sensing wheel rotation behavior of an automotive vehicle.
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TECHNICAL FIELD
This invention relates to a tool which defines a basket cavity for removing a discrete object from the body of a human or animal patient, said tool having an elongate shaft having a tool head at a distal end thereof, said tool head having a radially compact disposition and a radially spread disposition for embracing said object.
BACKGROUND ART
The present applicant manufactures a device for catching, fixing and removing foreign objects form the body of a human patient. These foreign objects can include stones, fragments and concrements in the medical fields of urology and gastro-enterology. In the present device, both ends of a number of individual wires are held together by a ring. Normally, the wires have a circular cross-section. One of these rings forms the distal end of a shaft and the other ring is spaced distally axially from the first ring. When the individual wires are all bowed radially outwardly and are distributed at regular intervals around the circumference of the axis, then these wires form longitudinal strands of an envelope defining a cavity centered on the long axis of the shaft. The wires are resilient and are given an outwardly bowed symmetrically or helically twisted shape so as to define a basket cavity radially inwardly of the envelope defined by the wires. The number of wires is usually in a range of from two to six. The entire device is placed within a sheath. For catching the foreign object, the distal end of the shaft and basket assembly is advanced out of the distal end of the sheath, allowing the resilience of the wires to form the basket by outward bowing. Once the foreign object is fished into the basket, then the shaft can be withdrawn proximally, to a greater or lesser extent, in order that the distal end of the sheath should squeeze down the diameter of the basket so that the basket wires grip the foreign object in the reduced diameter basket cavity immediately adjacent the distal end of the sleeve. Then the shaft and sleeve can together be withdrawn in the proximal direction to carry the foreign object in the basket out of the body.
In endoscopic surgery, a small diameter of the sheath is desirable. Currently the devices on the market have a sheath diameter falling within a range of outside diameters from 0.63 to 1.83 mm, which corresponds to a range of 1.9 to 5.5 French (1 French=⅓ mm).
One disadvantage of the presently marketed devices is that soldered, welded or glued joints are used to fix the individual wires to the rings and to the shaft. These connections represent a potential failure risk and, in any event, their ultimate strength has to be ascertained by extensive examination and testing.
Apart from this, the jointing of the wires at the rings defines the greatest outer diameter of the shaft element of the device, which therefore determines the inner diameter of the sheath and therefore indirectly determines the outer diameter of the sheath, setting a limit on the minimization of the outer sheath diameter.
Furthermore, the envelope of wires determines a characteristic mesh size of the basket and this mesh size has to be suitable both for fishing an object into the basket and then for retaining it within the basket until it has been removed from the body. Whereas a small mesh helps retention and removal, it does not help in the process of fishing the foreign object into the basket. A compromise mesh size has to be adopted.
EP-A-818 180 discloses an endoscope accessory in the form of a tube with a slitted distal end portion. The slits can be deformed radially outwardly to define a plurality of openings, by pulling from the proximal end of the tube on a pull wire 13 connected at its distal end to the distal end of the slitted portion. The disclosure of EP-A-737 450 is, in these respects, similar and U.S. Pat. No. 4,807,627.
EP-A-512 729 discloses an endoscopic surgical instrument which includes a tube having a slitted portion at its distal end. In a relaxed disposition of the wall portions between the slits, they are spaced apart from one another to form a basket. The slitted tube is itself co-axially within an outer tube having a distal end, and the basket can be closed down by drawing the basket, beginning at its proximal end, proximally into the outer tube, past the distal end of the outer tube. The slitted tube is made of a polyurethane material and the basket is formed by the application of steam heating to the slitted end.
DE-A-197 22 429 discloses a Nitinol tube, slitted at its distal end, for use as a basket to gather stones from bodily cavities. It is said to differ from previous such baskets in that the strands of the basket are unitary with the tube.
WO 94/18888 is another disclosure of a stone-gathering basket made from a plurality of Nitinol wires. The wires are arranged around the circumference of the basket in pairs and given a helical twist, which is said to increase the number of points of contact between the basket and entrapped calculi and to require of the physician no more dexterity than the prior art baskets, having a smaller number of contact points, required.
WO 96/23446 discloses a stone-gathering basket in which a distal half of the basket envelope exhibits a greater number of basket strands than the proximal half of the basket envelope. Each lengthwise strand in the proximal half of the baskets splits at half distance over the basket envelope into a plurality of strands which help to define the proximal half of the basket envelope. At the distal end of the basket is a cap to which all of the filaments defining the basket envelope are welded.
WO 99/16365 discloses a stone-gathering basket defined by a plurality of legs and with discussion what cross-sectional shapes of the legs are useful, and what surface topography on the inward facing surface of each leg.
WO 99/48429 is another disclosure of a stone gathering basket made unitary from a tube with longitudinal slits at its distal end, the basket being relaxed in its expanded configuration and of a material which can be a nickel titanium shape memory alloy such as Nitinol.
SUMMARY OF THE INVENTION
The present invention aims to mitigate some or all of the above-mentioned difficulties and, in any event, aims to improve present technology.
According to one aspect of the present invention, there is provided a medical device as described above, for removing a foreign object from the body of a human or an animal patient, which is characterized in that:
1. the shaft and tool head are formed from a single length of a tubing; 2. said tubing is slit lengthwise within a length contained within said tool head and stopping short of a distal end surface of said tube, thereby to form at least three parallel first strands which together define an envelope of said basket cavity; and 3. the tool is provided with a set of second strands, each formed by slitting one of the first strands over a distal portion of said first strand, which distal portion is less than the full length of the first strand.
In this way, it can be arranged that the mesh size of the basket structure, of the distal end of the basket, is provided as smaller apertures than are present at the proximal end of the basket. In this way, foreign objects can be fished into the basket at its proximal end, after which they can be retained in the smaller aperture mesh at the distal end of the basket. In one preferred embodiment, the second strands have a length in a range of from 45% to 80% of the length of the first strands.
It will be appreciated that, in the tool of the present invention, no joints are required. The basket is instead made from the base tubing of the shaft of the tool.
Further, it will be appreciated that the largest diameter of the tool is represented by the basic tubing itself, there being no larger diameter of rings at each end of the basket.
Conceivably, a basket could be constructed by slitting each of the second strands over a portion of its length which is less than the full length of the second strand, thereby to define a set of third strands over part of the length of the basket, setting a aperture size in that zone of the length of the basket smaller than would otherwise be the case in the absence of the third strands. For example, the zone of the third strands could be in a “belly portion” of the basket where its diameter is close to its maximum, thereby to achieve an aperture size in this belly portion smaller than an aperture size in a proximal half of the basket envelope, thereby better to retain an object captured in the proximal half of the basket in the smaller mesh size of the distal half of the basket.
Conveniently, the tubing is made from nickel titanium shape memory alloy and the strands are formed by a narrow diameter laser beam which cuts through the wall of the tubing.
It will be appreciated that, the device being based on a tube, there is the possibility to provide a guide wire or other core wire during use of the tool. For example, one could advance the tool into position along a previously placed guide wire. For laser cutting, one could set within the tubing work piece a core, so that the incident laser beam passes through one wall thickness and into the core, but not beyond the core into the wall thickness of the tubing on the opposite side of the core. In this way, one could slit the tube at 120° intervals around its circumference in order to create three first strands, and then the laser could be used to slit each of the three first strands, along a distal portion of its length, into two second strands, making a total of six second strands distributed at sixty degree intervals around the circumference of the tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the present invention, and to show more clearly how the same are recurred into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 is a longitudinal diagrammatic section of a prior art tool for removing a foreign object from the body of a patient;
FIG. 2 is a similar section through a first embodiment of a tool in accordance with the present invention, in its compact disposition;
FIG. 3 is a section corresponding to FIG. 2 , and showing the FIG. 2 tool in spread disposition;
FIG. 4 shows a transverse section through line IV-IV in FIG. 2 ;
FIG. 5 is a transverse section through line V-V of FIG. 2 ;
FIG. 6 is a longitudinal diagrammatic section of another embodiment of a tool in accordance with the present invention, in its compact disposition;
FIG. 7 is a section corresponding to FIG. 6 , and showing the FIG. 6 tool in spread disposition.
FIG. 8 is a longitudinal diagrammatic section of yet another embodiment of a tool in accordance with the present invention, in its compact disposition; and
FIG. 9 is a section corresponding to FIG. 8 , and showing the FIG. 8 tool in spread disposition.
DETAILED DESCRIPTION
Referring to FIG. 1 , a conventional tool has a shaft 12 with a distal end 14 on which is mounted a first ring 16 . Welded within the open distal end of the ring 16 , side by side, are four nickel titanium shape memory alloys circular section wires 18 . All four distal ends of the wire 18 are welded within an end ring 20 spaced from the distal end 14 to the shaft 12 and itself representing a distal end of the device 10 . Each of the wires 18 is given a bowed shape, as shown in the figure, by thermal treatment as is understood by those skilled in this art. The entire device is telescoped within a sleeve (not shown) having an inner diameter big enough to accommodate the rings 16 and 20 .
For catching and removing foreign objects, the distal end of the sleeve is advanced to a desired location within the body and then the shaft 12 is advanced until the basket 18 opens just distally beyond the distal end of the sleeve. Moving the sleeve, the medical practitioner fishes the target object into the cavity 22 within the basket defined by the wires 18 , and the shaft 12 is withdrawn proximally by a distance sufficient for the distal end of the sheath to squeeze the wires 18 onto the foreign object, thereby retaining it within the basket cavity 20 . Then the sheath and shaft are together withdrawn proximally, carrying the object out of the body.
The method of use of a tool in accordance with the present invention is similar. However, the manufacture of the tool is quite different, as can be seen from FIG. 2 .
FIG. 2 shows a tool 40 based on a single length of tubing 42 having a lumen 44 which runs its full length. The tube is of Nitinol shape memory alloy. Near the distal end of the tube 42 is provided a plurality of slits, comprising a set of four first slits 46 arranged at ninety degree intervals around the circumference of the tube 42 . Evenly spaced between each pair of first slits 46 are the slits of a set of four second slits 48 , again made by laser. FIG. 2 shows a core wire 49 which can be placed within the lumen 44 , at the distal zone of the tubing 42 , if it is desired for the incident laser beam to penetrate only one wall thickness of the tubing 42 , and not go beyond the lumen 44 (as would be appropriate if, for example, an arrangement of three first slits 46 , at 120 degree intervals around the circumference of the tubing 42 , were to be specified). The length of the set of first slits 46 corresponds to the desired length of the object-catching basket of the tool 40 .
Now referring to FIG. 3 , the basket of the FIG. 2 tool can be seen in its spread disposition. Just as Nitinol stents are given a remembered dimension by heat treatment, so the tool of FIG. 2 is given by heat treatment the basket shape illustrated in FIG. 3 . Thus, when the tubing 42 is advanced into a surrounding sheath, the strands 50 between adjacent first slits 46 , and the strands 52 , between adjacent first and second slits 46 , 48 , are squeezed down from the spread disposition of FIG. 3 into the compact disposition shown in FIG. 2 . Then, when the distal end of the tubing 42 is advanced distally out of the distal end of the sleeve, the strands 50 and 52 can take up the remembered deployed disposition of FIG. 3 .
FIGS. 3 , 4 and 5 reveal a valuable technical effect of the present invention, namely, that the mesh size of the basket can be varied, from one end of the basket to the other, allowing foreign objects to be introduced into the basket envelope through the relatively wide aperture zone of the proximal end of the basket, but then more securely retained within the basket at the relatively smaller diameter aperture portions at the distal end of the basket. Note also in FIG. 3 the presence of a guide wire 54 . The tool could be advanced on such a guide wire, into a desired location, then the guide wire 54 could be withdrawn proximally, to leave the basket cavity empty, and then the foreign object could be fished into the basket.
FIG. 6 shows a tool 40 ′ based on a single length of tubing 42 ′ having a lumen 44 ′ that runs its full length. Near the distal end of the tube 42 ′ is provided a plurality of slits, comprising a set of four first slits 46 ′ arranged at ninety degree intervals around the circumference of the tube 42 ′. At a distal end of the first slits 46 ′ and evenly spaced between each pair of first slits 46 ′ are the slits of a set of four second slits 48 ′, again made by laser. At a distal end of the second slits 48 ′ and evenly spaced between each pair of second slits 48 ′ are the slits of a set of eight third slits 58 ′, again made by laser. Other slit affangements are contemplated, such as, for example, three first slits 46 ′ at 120 degree intervals around the circumference of the tubing 42 ′. The length of the set of first slits 46 ′ corresponds to the desired length of the object-catching basket of the tool 40 ′.
Refeffing to FIG. 7 , the basket of the FIG. 6 tool can be seen in its spread disposition. The basket may be constructed by slitting each of the first strands 50 ′ over a distal portion of its length, which is less than the full length of the first strand, thereby defining a set of second strands 52 ′. These second strands 52 ′ may be further slit over a distal portion of its length which is less than the full length of the second strand, thereby defining a set of third strands 60 ′ over a distal part of the length of the basket, setting an aperture size in that zone of the length of the basket smaller than would otherwise be the case in the absence of the third strands 60 ′. The resulting strands achieve an aperture size smaller at the distal end than at the proximal end of the basket envelope, thereby better to retain an object in the smaller mesh size of the distal half of the basket, yet captured in the larger mesh size of the proximal half of the basket.
FIG. 8 shows a tool 40 ″ based on a single length of tubing 42 ″ having a lumen 44 ″ which runs its full length. Near the distal end of the tube 42 ″ is provided a plurality of slits, comprising a set of four first slits 46 ″ affanged at ninety degree intervals around the circumference of the tube 42 ″. Evenly spaced between each pair of first slits 46 ″ are the slits of a set of four second slits 48 ″, again made by laser. Evenly spaced between each pair of second slits 48 ″ are the slits of a set of eight third slits 58 ″, again made by laser. Other slit arrangements are contemplated, such as, for example, three first slits 46 ″ at 120 degree intervals around the circumference of the tubing 42 ″. The length of the set of first slits 46 ″ corresponds to the desired length of the object-catching basket of the tool 40 ″.
Referring to FIG. 9 , the basket of the FIG. 6 tool can be seen in its spread disposition. In this embodiment, the first strands 50 ″ extend along the a distal region of the tool head, stopping short of a distal end surface of the tubing. Second strands 52 ″ are within a distal portion of the first strand 50 ″, where the length of the second strand 52 ″ is less than a length of the first strand 50 ″. In a spread disposition, the second strand 52 ″ extends from a side of the first strand 50 ″ and is directed distally along its length toward the distal end of the tubing 42 ″. Third strand 60 ″ is within a portion of the second strand 52 ″, where the length of the third strand 60 ″ is less than the length of the second strand 52 ″. In the spread disposition, the third strand 60 ″ extends from a side of the second strand 52 ″ and is directed distally along its length toward the distal end of the tubing 42 ″. The distalmost ends of the first strands 50 ″ and second strands 52 ″ may be secured together at the tip 56 ″. In one embodiment, the zone of the third strands could be in a “belly portion” of the basket where its diameter is close to its maximum, thereby to achieve an aperture size in this belly portion smaller than an aperture size in a proximal half of the basket envelope, thereby better to retain an object captured in the proximal half of the basket in the smaller mesh size of the distal half of the basket.
Not immediately evident from the drawings is a further useful technical effect of the present invention. Whereas the distal ring 20 of the prior art device has a relatively significant length, the unslitted distal tip 56 of a device in accordance with present invention could be made relatively much shorter in length. This could improve the performance of the device when it is desired to fish into the basket an object which lies rather close to a tissue wall surface within a cavity or lumen of a body.
The cutting by laser of slits within the cylindrical wall surface of a tube of Nitinol shape memory alloy is a technology which is by now relatively well understood by those companies which specialize in the manufacture of self-expanding stents. For such companies, it will be apparent from the above description that the accompanying drawings and specific description given above represents only one example of how the concept of the present invention can be realized. The concept of the invention permits a new combination of stone destruction insitu by lithotripsy. The technique of lithotripsy involves hitting a stone with a probe which is itself struck by a projectile at the proximal end of the lithotripsy probe, to provide a kinetic energy ballistic impact on the stone to fragment the stone. It is envisaged that the device of the present invention would trap the stone and then a lithotripsy probe would be introduced into the proximal end of the tubular shaft and advanced into the basket at the distal end, to attack the stone trapped therein. A suitable probe can be obtained from EMS Electromedical Systems SA, CH-1347, Le Sentier, Switzerland.
To such readers, variations and modifications of these specific description above will be evident. The scope of the claims which follow is not to be taken as limited to the specific details of the description given above.
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Disclosed is a device for removing a foreign object from the body of a human or animal patient, the device being formed from a single length of tubing, slit lengthwise at its distal end to define an envelope of a basket cavity, the envelope featuring a set of second strands, each formed by slitting one of the first strands over a distal portion of the first strand, which distal portion is less than the full length of the first strand.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent document claims priority to earlier filed U.S. Provisional Patent Application Ser. Nos. 61/223,914, filed on Jul. 8, 2009, and 61/348,413, filed on May 26, 2010, and is a continuation in part of U.S. Design Patent Application Ser. No. 29/362812, filed on June. 1, 2010, the entire contents of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present patent document relates generally to window treatments and more specifically to an interchangeable window treatment for a Roman-style shade.
[0004] 2. Background of the Related Art
[0005] Roman-style shades are well known in the art. However, one disadvantage with Roman-style shades is that they do not easily permit the window treatment to be removed and replaced. In fact, the window treatment is often not removable at all from the head rail. Therefore, there is a perceived need for a window treatment for a Roman-style shade that permits the window treatment to be easily removed and replaced.
SUMMARY OF THE INVENTION
[0006] The present invention solves the problems of the prior art by providing a window treatment that can be easily removed and attached to a shade. In particular the window treatment includes a front portion and rear portion with a top, left, right and bottom edges. A number of fasteners are located on the top edge of the rear portion window treatment and near the bottom edge of the rear portion of the window treatment. The fasteners at the top edge are configured to attach to a head rail of a shade assembly and the fasteners near the bottom edge are configured to attach to a lifting mechanism of the shade assembly. The window treatment further includes a number of guides on the rear portion of the window treatment that guide the lifting mechanism in order to form decorative pleats in the window treatment as it is raised by the lifting mechanism of the shade assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:
[0008] FIG. 1 is a front view of a preferred embodiment of the window treatment of the present invention;
[0009] FIG. 2 is a rear view of a preferred embodiment of the window treatment of the present invention;
[0010] FIG. 3 is a rear view of a lifting mechanism and head rail assembly of a shade;
[0011] FIG. 4 is a front view of a user separating the fasteners at the top edge of the window treatment from the reciprocal fastener on the head rail of the shade assembly;
[0012] FIG. 5 is a rear view of a user separating the fasteners near the bottom edge of the window treatment from the reciprocal fastener on the lifting mechanism of the shade assembly;
[0013] FIG. 6 is a rear view of the preferred embodiment of the window treatment of the present invention attached to a shade assembly;
[0014] FIG. 7 a is a close up view of a guide engaged with a pocket on the window treatment and the lifting mechanism of the shade assembly;
[0015] FIG. 7 b is a close up view of a user partially removing a guide from the pocket on the window treatment and the lifting mechanism of the shade assembly;
[0016] FIG. 7 c is a close up view of a user partially removing a guide from the pocket on the window treatment and wholly separating the guide from the lifting mechanism of the shade assembly;
[0017] FIG. 8 a is a perspective view of a clip used as a guide on the window treatment of the present invention;
[0018] FIG. 8 b is a side view of a clip used as a guide on the window treatment of the present invention;
[0019] FIG. 9 a is a front view of the preferred embodiment of the window treatment of the present invention being partially lifted by the lifting mechanism of the shade assembly;
[0020] FIG. 9 b is a front perspective view of the preferred embodiment of the window treatment of the present invention being partially lifted by the lifting mechanism of the shade assembly;
[0021] FIG. 10 a is a rear view of the preferred embodiment of the window treatment of the present invention being partially lifted by the lifting mechanism of the shade assembly;
[0022] FIG. 10 b is a rear perspective view of the preferred embodiment of the window treatment of the present invention being partially lifted by the lifting mechanism of the shade assembly;
[0023] FIG. 11 a is a rear view of a alternative window treatment of the present invention showing the use of a unitary wire loop as guides;
[0024] FIG. 11 b is a rear view of a alternative window treatment of the present invention showing the use of wire hooks as guides;
[0025] FIG. 11 c is a rear view of a alternative window treatment of the present invention showing the use of a unitary rod as guides; and
[0026] FIG. 11 d is a rear view of a alternative window treatment of the present invention showing the use of a cloth pocket as guides.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring now to the FIGS. 1 and 2 , the window treatment of the present invention is shown generally at 10 . The window treatment 10 has a decorative front portion 12 and a rear portion 14 . The window treatment 10 may include multiple panels 16 or be a single large panel. The window treatment 10 further includes a top edge 18 , a left side edge 20 , a right side edge 22 and a bottom edge 24 . The window treatment 26 may further include an optional valance portion 28 depending from the top edge 18 of the window treatment 10 .
[0028] Referring now to FIG. 3 , an exemplary shade assembly is shown generally at 30 . The shade assembly 30 includes a support assembly 31 , a head rail 32 and a lifting mechanism 34 . The head rail 32 supports the window treatment 10 as further described below. The support assembly 31 supports the head rail 32 and lifting mechanism 34 . The lifting mechanism 34 is configured to raise and lower the window treatment 10 , which is further described below.
[0029] The lifting mechanism 34 includes a take up member 33 rotatably attached to the support assembly 31 . A lifting member 37 is attached to the take up member 33 . The take up member 33 is configured and arranged to gather and release the lifting member 37 .
[0030] The support assembly 31 may include one or more brackets 35 . The brackets 35 are configured to be mounted to a wall opening, such as a doorway, window opening or casement with fasteners, such as screws, nails or bolts. The brackets 35 may be configured to mount horizontally, vertically or at another angle to the wall or window opening. Additional spacers and braces may be used to support the brackets 35 against the wall opening. The head rail 32 may be connected to the brackets 35 of the support assembly 31 .
[0031] Referring now to FIG. 4 , one or more fasteners 36 a are provided at the top edge 18 of the window treatment 10 , which are configured to attach to a head rail 32 of a shade assembly 30 . The fasteners 36 a may be hook-and-loop fasteners, eyes to be fitted over hooks or buttons, snaps, zippers, and the like. The head rail 32 has the mating half 36 b of the fasteners 36 a to allow the window treatment 10 to be secured thereto.
[0032] Referring now to FIG. 5 , one or more fasteners 38 a are provided near the bottom edge 24 of the window treatment 10 , which are configured to attach to the lifting mechanism 34 of the shade assembly 30 . The fasteners 38 a may be hook-and-loop fasteners, eyes to be fitted over hooks or buttons, snaps, zippers, and the like. The lifting mechanism 34 on the shade assembly 30 has the mating half 38 b of the fasteners 38 a to allow the window treatment 10 to be secured thereto. Operation of the lifting mechanism 34 of the shade assembly 30 raises the window treatment 10 as further described below.
[0033] Because fasteners 36 a , 36 b , 38 a , 38 b are used, the window treatment 10 may be removed from the shade assembly 30 . This feature permits the user replace the window treatment 10 with another window treatment, e.g. a light summer window treatment may be replaced with a heavier winter window treatment, or a holiday patterned decorative window treatment, such as a pumpkin-themed pattern for Halloween for instance, may be hung to celebrate a particular holiday. This feature also permits the window treatment 10 to be easily cleaned because the user can take down and wash or clean the window treatment 10 .
[0034] Referring now to FIGS. 6 , 7 a - 7 c , 8 a and 8 b , further included on the rear portion 14 of the window treatment 10 are a number of spaced-apart guides. The guides may be formed as a pair of opposing clips 40 retained in a pocket 42 formed on the rear portion 14 of the window treatment 10 . The clips 40 include a first guide element 44 and a second guide element 46 spaced apart from the first guide element 44 . A slot is formed between the first guide element 44 and the second guide element 46 . The clip 40 further includes a toothed retaining element 48 spaced apart from the second guide element 46 that is received in the pocket 42 on the rear portion 14 of the window treatment 10 . The second guide element 46 may also include reciprocal teeth facing the retaining element 48 . The teeth on the retaining element 48 and the second guide element 46 prevent the clip 40 from being accidentally dislodged from the pocket 42 on the window treatment 10 .
[0035] Referring now to FIGS. 11 a - 11 d , instead of a clip 40 , a unitary wire loop 48 , wire hooks 50 , unitary rod 52 , or a cloth loop 54 may also be used. The critical factor is that the guides must allow the lifting member 37 to travel freely through the guide without undue snagging or resistance.
[0036] Referring to FIGS. 9 a , 9 b , 10 a and 10 b , the clips 40 guide the lifting member 37 as the take up member 33 gathers the lifting member 37 when the take up member 33 is rotated thereby causing the window treatment 10 to fold upon itself as the clips 40 are drawn together, forming decorative pleats 50 in the window treatment 10 . When the take member 33 is rotated in the opposite direction the take up member 33 releases the lifting member 37 causing the window treatment 10 to close. The lifting mechanism 34 is configured to gather and release the lifting member 37 .
[0037] Therefore, it can be seen that the present invention provides a unique solution to the problem of providing an interchangeably window treatment for a Roman-style shade that permits the user to easily remove, clean and replace the window treatment, or interchange a window treatment for another more desirable window treatment.
[0038] It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be within the scope of the present invention except insofar as limited by the appended claims.
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A window treatment is disclosed. The window treatment includes a panel having a front portion, a rear portion, a top edge and a bottom edge. A plurality of guides extends from the rear portion of the panel. The guides are configured and arranged to allow a lifting mechanism to slide therethrough. The guides may further include a clip portion configured and arranged to attached to a window treatment and a guide portion extending from the clip portion that is configured and arranged to slidably receive an edge of a lifting mechanism therein
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FIELD OF THE INVENTION
This invention relates to cellular compositions useful in medical treatments, processes for their preparation and their uses in medical treatments. More specifically, it relates to cellular compositions useful in alleviation of complications following allogeneic bone marrow transplantation, namely graft versus host disease in mammalian patients, especially in human patients, and to processes for preparation of such compositions of matter.
BACKGROUND OF THE INVENTION
Bone marrow transplantation, BMT, is indicated following a process which destroys bone marrow. For example, following intensive systemic radiation or chemotherapy, bone marrow is the first target to fail. Metastatic cancers are commonly treated with very intensive chemotherapy, which is intended to destroy the cancer, but also effectively destroys the bone marrow. This induces a need for BMT. Leukemia is a bone marrow malignancy, which is often treated with BMT after chemotherapy and/or radiation has been utilized to eradicate malignant cells. BMT is currently used for treatment of leukemias which are life-threatening. Some autoimmune diseases may be severe enough to require obliteration of their native immune systems which includes concomitant bone marrow obliteration and requires subsequent bone marrow transplantation. Alleviation of any but the most acute life-threatening conditions involving bone marrow disorders with BMT is, however, generally regarded as too risky, because of the likelihood of the onset of graft versus host disease.
Graft-versus-host disease, GVHD, is an immunological disorder that is the major factor that limits the success and availability of allogeneic bone marrow or stem cell transplantation (collective referred to herein as allo-BMT) for treating some forms of otherwise incurable hematological malignancies, such as leukemia. GVHD is a systemic inflammatory reaction which causes chronic illness and may lead to death of the host mammal. At present, allogeneic transplants invariably run a severe risk of associated GVHD, even where the donor has a high degree of histocompatibility with the host.
GVHD is caused by donor T-cells reacting against systemically distributed incompatible host antigens, causing powerful inflammation. In GVHD, mature donor T-cells that recognize differences between donor and host become systemically activated. Current methods to prevent and treat GVHD involve administration of drugs such as cyclosporin-A and corticosteroids. These have serious side effects, must be given for prolonged periods of time, and are expensive to administer and to monitor. Attempts have also been made to use T-cell depletion to prevent GVHD, but this requires sophisticated and expensive facilities and expertise. Too great a degree of T-cell depletion leads to serious problems of failure of engraftment of bone marrow stem cells, failure of hematopoietic reconstitution, infections, or relapse. More limited T-cell depletion leaves behind cells that are still competent to initiate GVHD. As a result, current methods of treating GVHD are only successful in limited donor and host combinations, so that many patients cannot be offered potentially life-saving treatment.
BRIEF REFERENCE TO THE PRIOR ART
International Patent Application No. PCT/CA97/00564 Bolton describes an autovaccine for alleviating the symptoms of an autoimmune disease in a mammalian patient, comprising an aliquot of modified blood obtained from the same patient and treated extracorporeally with ultraviolet radiation and an oxygen/ozone gas mixture bubbled therethrough, at an elevated temperature (42.5° C.), the autovaccine being re-administered to the same patient after having been so treated.
It is an object of the present invention to provide a process of alleviating the development of GVHD complications in a mammalian patient undergoing allo-BMT procedures.
SUMMARY OF THE INVENTION
According to the present invention, a patient being treated by allo-BMT is administered a composition containing T-cells obtained from an allogeneic donor, said T-cells having been subjected in vitro to oxidative stress to induce therein decreased inflammatory cytokine production coupled with reduced proliferative response. It appears that such oxidatively stressed allogeneic T-cells when injected into a mammalian patient, have a down-regulated immune response and a down-regulated destructive allogeneic response against the recipient, so that engraftment of the hematopoietic stem cells, administered along with or separately from the stressed T-cells, can take effect with significantly reduced risk of development of GVHD. The population of stressed T-cells nevertheless appears to be able to exert a sufficient protective effect on the mammalian system to guard against failure of engraftment and against infection, whilst the hematopoietic system is undergoing reconstitution, at least in part, by proliferation and differentiation of the allogeneic stem cells.
One aspect of the present invention provides, accordingly, a process of treating a mammalian patient for alleviation of a bone marrow mediated disease, with alleviation of consequently developed graft versus host disease (GVHD), which comprises administering to the patient allogeneic hematopoietic stem cells and allogeneic T-cells, at least a portion of said T-cells having been subjected to oxidative stress in vitro, prior to administration to the patient, so as to induce an altered cytokine production profile and a reduced proliferative response therein.
Another aspect of the present invention provides a population of mammalian T-cells, essentially free of stem cells, said T-cells having been subjected in vitro to oxidative stress so as to induce in said cells an altered cytokine production profile and a reduced proliferative response.
A further aspect of the present invention provides a process for preparing an allogeneic cell population for administration to a human patient suffering from a bone marrow mediated disease, which comprises subjecting, in vitro, a population of donor cells enriched in T-cells to oxidative stress to induce in said T-cells an altered cytokine production profile and a reduced proliferative response.
BRIEF REFERENCE TO THE DRAWINGS
FIGS. 1 and 2 of the accompanying drawings are graphical presentations of results obtained according to Example 3 below.
FIG. 3 is a depiction of the results obtained from Example 4 below.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process of the present invention involves an initial collection of hematopoietic stem cells and T-cells from a donor. The preferred source of such cells is mobilized stem cells and T-cells from the peripheral blood of the donor. Stem cells are present in very small quantities in peripheral blood, and one preferred way of operating in accordance with the invention is to enrich the stem cell population of the donor's peripheral blood, and then to extract the donor's peripheral blood for use as a source of stem cells and T-cells for treatment as described and subsequent injection into the patient. Enrichment may be achieved by giving the donor a course of injections of appropriate growth factors, over several days e.g. five days prior to extracting peripheral blood from the donor. Appropriate cell fractions can be collected from the blood by leukopheresis, a known procedure, as it is extracted, with the plasma and red cells being returned to the donor, in a closed flow system. The white cell collection, which contains the stem cells (about 3%) and T-cells (about 40%) along with B-cells, neutrophils and other white cells, may be treated to alter their cytokine production profiles and to reduce the proliferative response of the T-cells therein, and then administered to the host patient, in accordance with the invention, as a whole collection of cells (peripheral blood mononuclear cells). Preferably, however, the donor T-cells are separated from the other cells, so that only the T-cells are subjected to oxidative stress and then administered to the patient, with the stem cells for engraftment being administered to the patient separately from the treated T-cells. For practical purposes, however, subjection of the collection of peripheral blood mononuclear cells to the stressors is satisfactory, without further fractionation to isolate the T-cells, which is a difficult and expensive procedure. Separate administration of stem cells is strongly preferred.
If for some reason it is desired to subject the entire white cell collection to oxidative stress to induce the aforementioned changes in the T-cell portion thereof, and then administer the entire collection to the patient, it is preferred to protect the stem cells from any damaging effects of the oxidative stress in a manner described below.
In an alternative, but less preferred, procedure, whole bone marrow of the donor can be used as the source of T-cells and stem cells for the process of the invention. Whole bone marrow has in the past been the usual source of cells for allogeneic cell transplantation procedures, and can indeed be used in the present process. It is however an inconvenient and uncomfortable procedure for the donor, requiring anaesthetic and lengthy extraction procedures. Any source of T-cells and stem cells from the donor can be used in principle, but peripheral blood enriched in stem cells and T-cells is the most clinically convenient.
The alteration in cytokine production profile induced in the T-cells in the process of the invention is preferably a reduction in production of inflammatory cytokines, such as interferon-γ and tissue necrosis factor-α.
The oxidative stress may be applied to the T-cells by subjecting them to an oxidative environment such as the addition of a gaseous, liquid or solid chemical oxidizing agent (ozone, molecular oxygen, ozone/oxygen gas mixtures, permanganates, periodates, peroxides, drugs acting on biological systems through an oxidative mechanism such as adriamycin, and the like). In one preferred method according to the invention, the T-cells are subjected, in suspension, to a gaseous oxidizing agent, such as an ozone/oxygen gas mixture bubbled through the suspension of cells, optionally in combination with the simultaneous subjection of the cells to ultraviolet radiation, in appropriate doses.
One method according to the present invention subjects the allogeneic white cells from the donor, including both the stem cells and the T-cells, to oxidative stress. This eliminates the need to include a complicated and costly step of separating the T-cells from the other cellular components of the white cells composition. In such case, however, it is strongly preferred to protect the stem cells in the composition from deleterious effects of the stress. This can be accomplished by including one or more stem cell growth factors in the cell composition at the time of subjecting it to the stress. Protection of the stem cells from the deleterious effects of the oxidative stress is achieved by the presence of growth factors, and so, prior to subjecting the stem cell-T-cell composition to oxidative stress, one or more stem cell growth factors are added to the composition. Stem cell growth factors useful in the process are cytokines which promote survival of stem cells (but not T-cells) during this stressing. They are cytokines which interact with growth receptors on stem cells. They are believed to activate the MAP-kinase pathway of the cell, resulting in the activation of erk. Examples of suitable such growth factors, include stem cell specific growth factors, kit-ligand, IL-3, GM-CSF and FLT 3 ligand, all of which are known. It is preferred to add precise amounts of extracted, purified growth factors or, especially, recombinant growth factors available on the market, or combinations thereof, suitably dissolved or suspended in appropriate, biologically acceptable fluids.
One preferred method of subjecting the allogeneic T-cells to oxidative stress according to the invention involves exposing a suspension of the cells to a mixture of medical grade oxygen and ozone gas, for example by bubbling through the suspension a stream of medical grade oxygen gas having ozone as a minor component therein. The suspending medium may be any of the commonly used biologically acceptable media which maintains cells in viable condition. The ozone gas may be provided by any conventional source known in the art. Suitably the gas stream has an ozone content of from about 1.0-100 μg/ml, preferably 3-70 μg/ml and most preferably from about 5-50 μg/ml. The gas stream is supplied to the aliquot at a rate of from about 0.01-2 liters per minute, preferably 0.05-1.0 liters per minute, and most preferably at about 0.06-0.30 liters per minute (STP).
Another method of subjecting the T-cells to oxidative stress to render them suitable for use in the present invention is to add to a suspension of the cells a chemical oxidant of appropriate biological acceptability, and in biologically acceptable amounts. Permanganates, periodates and peroxides are suitable, when used in appropriate quantities. Hydrogen peroxide is useful in demonstrating the effectiveness of the process of the invention and in giving guidance on the appropriate quantity of oxidizing agent to be used, although it is not an agent of first choice for the present invention, for practical reasons. Thus, a suitable amount of oxidizing agent is hydrogen peroxide in a concentration of from 1 micromolar-2 millimolar, contacting a 10 ml suspension containing from 10- 6 to 10- 8 cells per ml, for 20 minutes, or equivalent oxidative stress derived from a different oxidizing agent. Optimum is about 1 millimolar hydrogen peroxide in such a suspension for about 20 minutes, or the equivalent of another oxidizing agent calculated to give a corresponding degree of oxidative stress to the cells.
The size of the cell suspension to be subjected to oxidative stress is generally from about 0.1 ml to about 1000 ml, preferably from about 1-500, and containing appropriate numbers of T-cells for subsequent administration to a patient undergoing allo-BMT. These numbers generally correspond to those used in prior methods of allogeneic T-cell administration in connection with allo-BMT, and are familiar to those skilled in the art.
One specific process according to the invention is to subject the cell suspension simultaneously to oxygen/ozone bubbled through the suspension and ultraviolet radiation. This also effects the appropriate changes in the nature of the T-cells. Care must be taken not to utilize an excessive dosage of oxygen/ozone or UV, to the extent that the cell membranes are caused to be disrupted, or other irreversible damage is caused to an excessive number of the cells.
The temperature at which the T-cell suspension is subjected to the oxidative stress does not appear to be critical, provided that it keeps the suspension in the liquid phase and is not so high that it causes cell membrane disruption. The temperature should not be higher than about 45° C.
When ultraviolet radiation is used in conjunction with the oxygen/ozone oxidative stressor, it is suitably applied by irradiating the suspension under treatment from an appropriate source of UV radiation, while the aliquot is maintained at the aforementioned temperature and while the oxygen/ozone gaseous mixture is being bubbled through the aliquot. The ultraviolet radiation may be provided by any conventional source known in the art, for example by a plurality of low-pressure ultraviolet lamps. There is preferably used a standard UV-C source of ultraviolet radiation, namely UV lamps emitting primarily in the C-band wavelengths, i.e. at wavelengths shorter than about 280 nm. Ultraviolet radiation corresponding to standard UV-A and UV-B sources can also be used. Preferably employed are low-pressure ultraviolet lamps that generate a line spectrum wherein at least 90% of the radiation has a wavelength of about 254 nm. An appropriate dosage of such UV radiation, applied simultaneously with the aforementioned temperature and oxidative environment stressors, is obtained from lamps with a power output of from about 5 to about 25 watts, preferably about 5 to about 10 watts, at the chosen UV wavelength, arranged to surround the sample container holding the aliquot. Each such lamp provides an intensity, at a distance of 1 meter, of from about 40-80 micro watts per square centimeter. Several such samples surrounding the sample container, with a combined output at about 254 nm of 15-40 watts, preferably 20-40 watts, operated at maximum intensity may advantageously be used. At the incident surface of the aliquot, the UV energy supplied may be from about 0.25-4.5 j/cm 2 during a 3-minute exposure, preferably 0.9-1.8 j/cm 2 . Such a treatment provides a suspension aliquot which is appropriately modified according to the invention ready for injection into the patient.
The time for which the aliquot is subjected to the stressors can be from a few seconds to about 60 minutes. It is normally within the time range of from about 0.5-60 minutes. This depends to some extent upon the chosen intensity of the UV irradiation, the temperature and the concentration of and rate at which the oxidizing agent is supplied to the aliquot. Some experimentation to establish optimum times and dosages may be necessary on the part of the operator, once the other stressor levels have been set. Under most stressor conditions, preferred times will be in the approximate range of about 0.5-10 minutes, most preferably 2-5 minutes, and normally around 3 minutes.
In the practice of one preferred process of the present invention, the suspension of cells may be treated with oxygen/ozone gas mixture and optionally also with UV radiation using an apparatus of the type described in U.S. Pat. No. 4,968,483 Mueller. The suspension is placed in a suitable, sterile, UV-radiation-transmissive container, which is then fitted into the machine. The temperature of the aliquot is adjusted to the predetermined value, e.g. 42.5±1° C., by the use of a suitable heat source such as an IR lamp, and the UV lamps are switched on for a fixed period before the gas flow is applied to the aliquot providing the oxidative stress, to allow the output of the UV lamps to stabilize. The oxygen/ozone gas mixture, of known composition and control flow rate, is applied to the aliquot, for the predetermined duration of 0.5-60 minutes, preferably 1-5 minutes and most preferably about 3 minutes as discussed above. In this way, the suspension is appropriately modified according to the present invention sufficient to achieve the desired effects of alleviation or prevention of GVHD.
From another aspect, the preferred embodiment of the present invention may be viewed as a process of treating allogeneic T-cells prior to their introduction into a patient, by extracorporeally stressing the T-cells, which comprises subjecting the T-cells to oxidative stress such as exposure to ozone or ozone/oxygen. The treated allogeneic T-cells from the process of the invention have a direct effect on the development and progression of GVHD. The donor T-cells pretreated according to the process of the invention prior to introduction into the host patient, have been modified, so that they no longer mount a deleterious response. Their ability to mount an inflammatory cytokine response has been decreased. For example their ability to secrete IFNγ, TNFα and IL-2, and their proliferative response to standard mitogens has been reduced. Accordingly they no longer react against incompatible systemically distributed host histocompatibility antigens to cause inflammation to any great extent. The allogeneic stem cells administered to the patient can proceed with engraftment with improved chance of success. After a period of time, the treated T-cells largely recover their proliferative ability and immune response functions, but remain relatively unresponsive (tolerant) to differing host histocompatibility antigens.
The invention is further described, for illustrative purposes, in the following specific examples.
SPECIFIC DESCRIPTION OF THE MOST PREFERRED EMBODIMENTS
The spleen of a mammal offers a convenient, accessible source of cells, especially T-cells but also including small quantities of stem cells and is particularly useful in connection with animal models for experimental purposes.
Experimental testing to obtain indication of the utility of the process of the present invention was conducted using a model of acute GVHD in SCID mice. T-cells from C57B1/6J (B6) mice were intravenously injected into sub-lethally irradiated CB-17 SCID mice. The latter are congenitally lymphopenic and provide a strong stimulus for donor cells due to their complete disparity at the major histocompatibility locus (MHC). The mean survival time of host mice in this model is 14 days. GVHD is characterized by suppression of host hematopoietic recovery from irradiation; expansion of T-cells that use Vβ3 chain to form their T-cell receptor complexes (TCR's); spontaneous secretion of interferon-γ and TNF-α, by donor T-cells, and aberrant localization of donor T-cells to the red pulp areas of the spleen. If donor marrow is co-injected with T-cells, a chronic form of GVHD results.
EXAMPLE 1
Mouse spleen cells from C57B1/6J (B6) mice were suspended to a density of 10 7 /ml in α-MEM, 2ME and 10% fetal calf serum (FCS). The FCS contains cytokines and growth factors. The cell suspension was subjected simultaneously to ultraviolet radiation from UV-C lamps, wavelength 253.7 nm, whilst bubbling through the suspension a gas mixture of 14-15 mcg/ml ozone/medical grade oxygen, at 42.5° C. The treatment took place for 3 minutes.
Immediately after the treatment, the cells had a viability of only about 10%.
EXAMPLE 2
The experiment of Example 1 was essentially repeated except that the cells were suspended in 100% FCS. The immediate survival of the cells in this case was 50-60%, indicating that factors present in the FCS have exerted a protective effect on at least some of the cells.
EXAMPLE 3
Murine B6 spleen cells suspended in 100% FCS were subjected to UV-oxidation-heat treatment. The cell suspension was subjected simultaneously to ultraviolet radiation from UV-C lamps, wavelength 253.7 nm, whilst bubbling through the suspension a gas mixture of 14-15 mcg/ml ozone/medical grade oxygen, at 42.5° C. The treatment took place for 3 minutes. Varying numbers were injected into sub-lethally irradiated CB-17 SCID mice. Their subsequent behaviour was compared with similar numbers of B6 spleen cells, not subjected to the treatment.
FIG. 1 is a graphical presentation of the results of these experiments, where the % survival of the animals in each group is plotted as ordinate against days following injection of the treated or untreated cells. At all dosage levels, there is a marked improvement of survival when the treated cells are used as opposed to the untreated cells, demonstrating potential for the process of the invention in alleviating GVHD.
FIG. 2 of the accompanying drawings is a plot of the number of donor T-cells per spleen against days after GVHD induction, in these same experiments. This shows that the treated donor T-cells survive and expand in number in the host mice, although to a more limited degree than control, untreated B6 T-cells.
EXAMPLE 4
Six days after initiation of GVHD in the mice by injection of the donor cells (treated and untreated), donor T-cells were separated from SCID spleen cells by density gradient centrifugation. Intracellular cytokine staining was performed according to the method of Ferrick, D. A. et. al., NATURE 373 225, 257, 1995. The staining was performed on spleen cell suspensions on day 8 after injection of B6 spleen cells. Cytokine production was determined 4 hours after stimulation in vitro with PHA and ionomycin in the presence of brefeldin-A and after gating on CD4 + and CD8 + . The results were assessed by intracellular flow cytometry, and the results thereof are depicted in FIG. 3 of the accompanying drawings. The percentage of each cells in each quadrant is recorded. The drawing shows significantly reduced levels of the inflammatory cytokines interferon-γ (INF) and tissue necrosis factor-α (TNF), lower right quadrants, from the T-cells which had been stressed as described in Example 1, as compared with untreated cells and controls.
EXAMPLE 5
Inversion of the normal ratio of CD4+ to CD8+ T-cells (usually approximately 2:1) is known to accompany GVHD. By intracellular cytokine staining techniques following the method of Ferrick et.al., Nature 373: 255-257, 1995 and using anti-CD4 and CD8-tricolor antibodies, CD4/CD8 ratios were determined. In the untreated donor spleen cells after injection into sub-lethally irradiated mice, the inversion of the normal ratio was confirmed. The initial CD4/CD8 ratios of 1.3±0.2 and 2.2±0.3 decreased to 0.33±0.05 and 0.9±0.1 by day 13 for unstressed B6 and C3H donor T cells, respectively, at a time when many animals were succumbing to GVHD. In contrast, the ratios remained greater than 1 at all times and correlated with the lack of clinical evidence of GVHD when donor cells had been pretreated with the stressors as described in Example 1.
EXAMPLE 6
This example demonstrates the principle of the invention, using oxidative stress alone, provided by hydrogen peroxide, an effective chemical oxidizing agent and representative of many other, perhaps more biologically suitable, chemical oxidizing agents.
Peripheral human blood mononuclear cells PBMCs, which is a collection of white blood cells comprising about 40% T-cells, were stressed by contact with aqueous solutions of hydrogen peroxide, of various concentrations, for 20 minutes. Their immediate survival was measured, along with their immediate phytohaemagglutinin (PHA) response. Then their survival after 24 hours was measured, followed by their PHA response (tritiated thymidine uptake following mitogenic stimulation with PHA) and cytokine profile after 7 days. The results are given in the following table.
TABLE
Immediate
PHA
Conc.
Immediate
24 hr
PHA
response
Cytokine
H 2 O 2
survival %
survival %
response
7-day
Profile
100 μmole/L
80-90
100
2000
+
IFN↓
300 μmole/L
80-90
50
2000
+
IFN↓
1 mmole/L
80-90
40
400
+
IFN↓
3 mmole/L
80-90
40
400
+
IFN↓
Control
95
95
8575
+
IFN↑
These results indicate that T-cells subjected to oxidative stress alone achieve a decreased proliferative response and decreased inflammatory cytokine production, suitable for use in the present invention.
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The development of graft versus host disease in a mammalian patient undergoing cell transplantation therapy for treatment of a bone marrow mediated disease, is prevented or alleviated by subjecting at least the T-cells of the allogeneic cell transplantation composition, extracorporeally, to oxidative stress, in appropriate dosage amounts, such as bubbling a gaseous mixture of ozone and oxygen through a suspension of the T-cells. The process may also include irradiation of the cells with UV light, simultaneously with the application of the oxidative stress. The oxidative stress induces reduced inflammatory cytokine production and a reduced proliferative response in the T-cells.
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This is a Continuation of International Application PCT/DE96/01705, with an international filing date of Sep. 11, 1996 the disclosure of which is incorporated into this application by reference.
FIELD OF AND BACKGROUND OF THE INVENTION
The invention relates to new and useful improvements in electromotive actuators. More particularly, the invention relates to an electromotive actuator for a part which opens and closes (hereinafter termed a closing part), such as a window or a sliding roof in a motor vehicle.
German Utility Model 92 17 563 discloses an electromotive actuator for a closing part, for example for a motor vehicle window or a motor vehicle sliding roof, in which the position of the closing part is recorded electromotively and stored. When a specific distance from one end position of the closing part is reached, the motor power is reduced, whereby the speed of movement is reduced to a minimum value. This ensures a smooth and reliable run into the end position. Moreover, for protection against jamming, the power consumption of the electric motor is monitored against a previously stored power consumption.
European Patent 0,261,525 discloses a geared motor actuator for a motor vehicle window drive having a worm gear. The worm shaft is provided on an extended motor shaft end and drives a worm wheel. The worm wheel is axially plug-connected to an output driver plate by means of a fitting engagement. This driver plate drives the remaining window lifting mechanism. The worm gear arrangement uses the electric motor to drive the window pane with full torque into its end position, i.e., either the "window closed" or "window opened" position, until a limit stop is reached.
In order to dampen the impact stresses which otherwise would act on the motor and the other parts of the gear assembly, an elastic damping element is provided between the worm wheel and the driver plate mounted axially in front of the worm wheel. The worm wheel is driven by the motor shaft via the worm shaft and the driver plate is driven positively by means of the aforementioned plug connection. Consequently, when the window drive reaches one of the two end positions described above, the stop impact is reduced and absorbed radially and tangentially. It is also possible, instead of having a separate damping element, to design the components themselves to dampen impact stresses. This is done, for example, by placing elastic spokes along the transmission path between the worm shaft and the driver plate output.
German Laid-Open Publication 44 32 955 discloses an electromotive drive for a motor vehicle window. Its control device is provided with an excess force limitation function, such that the raising/lowering movement is terminated when the window reaches one of the two end positions provided with a corresponding limit stop. In addition, the excess force limitation is cut off automatically before the window reaches the upper seal. This prevents the increased drive forces which occur when the window enters the seal from triggering the excess force limitation. For this purpose, the window height corresponding to this distance is stored by assigning a fixed reference position to the window when it is in its closed position, with its top edge bearing on the upper limit stop. A position or movement counter can then sense from this reference position when the defined distance is reached as the pane moves upward. The excess force limitation can consequently be cut off automatically.
OBJECTS OF THE INVENTION
It is a first object of the invention to provide sufficient protection against damage due to mechanical impact stresses by means of an electromotive actuator, in particular for a window or sliding roof in a motor vehicle. It is a further object to provide an electromotive actuator for a closing part, in particular for a window or sliding roof in a motor vehicle, which is simplified in construction. According to another object of the invention, the design and therefore the manufacture and assembly of a geared motor actuator is to be simplified.
SUMMARY OF THE INVENTION
These and other objects are achieved by the teachings recited in the independent claims. Particularly advantageous refinements of the invention are the subject matter of the dependent claims.
According to one formulation of the invention, an electromotive actuator is provided for moving a part, e.g., a window of a motor vehicle, through a range of available travel extending between a first end position and a second end position. The actuator includes an electric motor for moving the part selectively between the first end position and the second end position as well as a control device for electronically recording both the current position and current speed of the part. The control device is capable of interrupting power to the electric motor when the part reaches a coasting position, at which the part has substantially sufficient kinetic energy to move to the end position without further kinetic energy being imparted from the electric motor. The coasting position is calculated based on, e.g., the recorded current position and current speed of the part.
Fully utilizing the motor drive power for as rapid an opening or closing movement of the closing part as possible, the present invention makes it unnecessary to use separate intermediate damping parts or to design the intermediate transmission means to be elastic. In particular it is unnecessary to provide elastic spokes for the worm wheel or driver plate of the worm gear following the driving electric motor, for dampening impact stress. According to one preferred embodiment of the invention, the worm wheel and driver plate are combined into a solid, in particular injection-molded, component which is simple to produce. The component has the additional benefit of facilitating manufacture and assembly of the geared motor actuator.
The control device used in conjunction with the invention is, advantageously, generally similar to known devices, and is for example similar to that described in German Laid-Open Publication 44 32 955 mentioned above. All that is needed is a slight modification of the electric control of this device.
By once-only standardization, which only needs to be repeated after a power failure or the like, one of the two end positions is initialized by moving the window to that position. This end position is then stored. In a window drive or sliding roof drive, despite the fact that the invention requires no gear-side damping element, the end position selected is advantageously that into which the closing part can run with sufficient impact damping because of the seal present there. The other end position, in particular the closed position, is then established by the range of travel of the window or sliding roof, e.g., by means of an incremental sensor. The control device can then be set to switch off the electric motor driving the closing part shortly before the other end position is reached, such that the closing part is brought into its ultimate end position, without any impact stress, by means of simply its kinetic energy.
The position of the closing part, its range of travel and/or its instantaneous speed can be determined in a simple way by means of at least one sensor, for example a Hall sensor, assigned to the drive motor, by recording sensor pulse counts or pulse intervals.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and further advantageous refinements thereof according to the features of the dependent claims are explained in more detail below with the aid of diagrammatic, exemplary embodiments in the drawing, in which:
FIGS. 1A-1B show radial sections through the gear cases of two embodiments of a motor-operated automotive vehicle window drive;
FIG. 2 shows a block diagram illustrating the components of an actuator for executing the raising/lowering movement and for recording the range of travel of the window; and
FIG. 3 shows a block diagram illustrating the components of a control device governing the raising/ lowering movement and the recording of the range of travel for the actuator according to FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A shows a radial section through a gear of a motor vehicle window drive, with a cup-shaped gear case 2. The gear case 2 is covered by a gear case cover 3 so as to provide a moistureproof seal. A commutator motor rotor shaft extending as a worm shaft 1 projects into the gear case 2,3, which is flanged to the commutator motor housing, and drives a worm wheel 4 which meshes with the worm shaft 1. The commutator motor can be of a type, e.g., as disclosed in German Utility Model 89 03 714. The worm wheel 4 is rotatably mounted on a bearing neck of the gear case cover 3 and is sealed off from the cover by a dynamic seal 5.
Advantageously, the worm wheel 4, being a solid integral component, in particular a plastic injection molding, is designed to include an integrated output driver 4.0. Thus, the worm wheel 4 projects outward through a central orifice of the gear case cover 3 and has a drive pinion 4.1, to which a lifter mechanism H (see FIG. 2) can be coupled for raising or lowering a window S. Alternatively, the worm wheel and the output driver can be designed as separate components, such that the worm wheel 4 and the output driver 6, with pinion 6.1, mesh via a fitted plug-in connection, as shown by way of example in FIG. 1B.
An electric motor MO, preferably a commutator motor, which drives the lifter mechanism H via the gear G, is switched to righthand rotation, lefthand rotation or stop by a control device ST via a power switch LS. The power switch LS used may be, e.g., two changeover relays or one double relay or else a semiconductor switch, in particular in an H-bridge connection. The control device ST controlling the power switch LS and consequently the electric motor MO is dependent on an output signal S-SE from a sensor SE which supplies signals from the electric motor MO to the input of the control unit ST. These signals are proportional to the direction of rotation or to the rotational speed of the motor MO.
The sensor SE, known per se, is advantageously provided for recording both the direction of rotation and the rotational speed of the electric motor MO on the basis of signals which occur at specific, defined intervals. Two Hall probes, which are spaced at a circumferential angle of 90° and are preferably integrated into the brush system of the permanent magnet excitation electric motor MO are normally provided for this purpose. These Hall probes are assigned to a bipolar magnetic wheel on the rotor shaft of the electric motor MO.
This results in two phase shifted, preferably rectangular signals from the sensor. The phase differences of the signals determine the direction of rotation of the electric motor MO and consequently the direction of the raising/lowering movement of the window S. For example, righthand rotation of the motor MO corresponds to the window S being raised and lefthand rotation to the window S being lowered. The travel range of the window S can be determined by counting the flanks of the signals. The speed of the electric motor MO and, given the fixed gear ratio to the lifter mechanism H, also the speed of the window S being moved are inversely proportional to the time intervals of the signal flanks recorded by the sensor SE.
The signal S-SE coming from the sensor SE is supplied to two processing units, namely an up/down counter Z and a pulse time recorder PZ. The pulse time recorder PZ generates a speed-proportional signal from the time intervals of the flanks recorded by the sensor SE. This signal is fed to a threshold switch SS. The up/down counter Z evaluates the information of the signal S-SE from the sensor SE by means of a signal from an end position recorder EP, which produces a signal that is proportional to the absolute position and therefore to the current range of travel. This signal is fed to the threshold switch SS as well. More specifically, the end position recorder EP provides a signal which enables an absolute position to be generated from the relative position. The relative position is generated by counting the flanks of the signals from the sensor SE according to direction.
When the window S first reaches an end position, the end position recorder sets the up/down counter Z to an initial value, i.e. initializes it. If the upper position corresponds to the number 0, the lower position then gives a value which is proportional to the length of the window S. Initialization by the end position recorder EP need be repeated only when the system cannot recognize its absolute position from the stored data. This may occur, for example, after a voltage drop caused by disconnection of the vehicle battery.
The output signal from the threshold switch SS activates the power switch LS via a decision logic unit LO. The latter is designed so that the signal coming from the threshold switch SS takes effect only when there is an adjustment command A-HE for "raise" or "close", i.e., only in the direction of raising/closing. The threshold switch SS is dependent on the speed-proportional output signal from the pulse time recorder PZ in such a way that the kinetic energy of the window S becomes zero when or shortly before the end position of the pane S is reached.
Alternatively, to simplify matters, this decision logic unit LO may be dispensed with in connection with a "lower" or "open" adjustment command, generally for the following reasons:
When the lower end position "open" is reached, it is relatively unimportant whether the window S runs into the lower seal a few millimeters more or less. The only important factor is that the electric motor MO is switched off early enough to ensure that the window S never moves up against the lower limit stop with undue impact stress. There is therefore no need for a switch-off time which is calculated individually in each case according to speed. This time is only fixed during initialization over the entire travel of the window S.
By contrast, it is necessary for the window to move to the upper end position "close" exactly, so as to ensure equally good sealing in a consistent, reliable manner. For this purpose, the device uses a speed-dependent switch-off which can be calculated individually in each case. It is then possible for the window S to move as smoothly as possible until shortly before it reaches the upper end position, that is the closing position. Ideally, after the electric motor MO has been switched off, the window S comes to a stop at the closing and sealing upper end position, without any undue impact stress, due to the dynamic energy previously imparted to it.
Due to tolerances in the system as a whole, the window S will not, or at least not always, come to a stop exactly at the upper end position, even when the system is adjusted as accurately as possible. Since the position of the window S is measured, e.g., by the method of incremental sensors and initialization described above, if the end position is not yet reached completely, the distance between the upper end position and the point at which the window S came to a stop is known. This short distance can be overcome by switching the electric motor MO on once again, so that the window S then runs into the end position with very little kinetic energy. While this is happening, the moving parts of the system cannot reach appreciable speed over the short distance and therefore also do not absorb any appreciable kinetic energy that would result in impact stresses.
The subject of the invention has been explained with reference to a window drive for a motor vehicle. However, the scope of the present invention also embraces use of the invention in similar drives for other types of closing parts capable of being driven between an opening position and a closing position by an actuator. One example is a drive for a sliding roof of a motor vehicle.
The above description of the preferred embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and its attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof.
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A geared motor actuator having a simplified mechanical structure for driving a closing part, such as a vehicle window, moved as far as at least one end position by an electric motor (MO) via a gear (G), preferably a worm gear. Shortly before the end position is reached, switch-off of the electric motor (MO) is performed in accordance with a control device (ST). The gear (G) is drive-connected to an output driver of the closing part without any damping means. The worm wheel (4) of the worm gear, being a solid, integral component that is preferably injection-molded from plastic, is preferably designed to include the output driver as part of the integral component, and provided with a drive pinion (4.1).
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This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/249,145, filed Nov. 16, 2000, entitled CONTROL SYSTEM METHODS AND APPARATUS FOR INDUCTIVE COMMUNICATION ACROSS AN ISOLATION BARRIER.
BACKGROUND OF THE INVENTION
The invention relates to control systems and, more particularly, to methods and apparatus for transferring information across an isolation barrier between control devices such as, by way of non-limiting example, field devices and the systems that monitor and/or control them. The invention has application in the exchange of data/control signals in process, industrial, environmental and other control systems.
The terms “control” and “control systems” refer to the control of a device or system by monitoring one or more of its characteristics. This is used to insure that output, processing, quality and/or efficiency remain within desired parameters over the course of time. In many control systems, digital data processing or other automated apparatus monitor a device, process or system and automatically adjust its operational parameters. In other control systems, such apparatus monitor the device, process or system and display alarms or other indicia of its characteristics, leaving responsibility for adjustment to the operator.
Control is used in a number of fields. Process control, for example, is typically employed in the manufacturing sector for process, repetitive and discrete manufactures, though, it also has wide application in utility and other service industries. Environmental control finds application in residential, commercial, institutional and industrial settings, where temperature and other environmental factors must be properly maintained. Control is also used in articles of manufacture, from toasters to aircraft, to monitor and control device operation.
Modern day control systems typically include a combination of field devices, control devices, workstations and, sometimes, more powerful digital data processors. Field devices are the “eyes, ears and hands” of the control system. They include the temperature, flow and other sensors that are installed on or in the process equipment to measure its characteristics. They also include positioners and other actuators that move or adjust the equipment settings to effect control.
Controllers generate settings for the control devices based on measurements from sensor type field devices. Controller operation is typically based on a “control algorithm” that maintains a controlled system at a desired level, or drives it to that level, by minimizing differences between the values measured by the sensors and, for example, a setpoint defined by the operator.
Workstations, control stations and the like are typically used to configure and monitor the process as a whole. They are often also used to execute higher-levels of process control, e.g., coordinating groups of control devices and responding to alarm conditions occurring within them.
In an electric power plant, for example, a workstation coordinates control devices that actuate conveyors, valves, and the like, to move coal or other fuels to a combustion chamber. The workstation also configures and monitors the control devices that maintain the dampers to control the level of combustion. The latter operate, for example, by comparing in the temperature of the combustion chamber with a desired setpoint. If the chamber temperature is too low, the control algorithm may call for incrementally opening the dampers, thereby, increasing combustion activity and diving the temperature upwards. As the temperature approaches the desired setpoint, the algorithm incrementally levels the dampers to maintain the combustion level.
The field devices, control devices, workstations and other control-related that make up a process control system are typically connected by a hierarchy of communications lines. Ever increasingly, these are Ethernet or other IP network connections, though various buses are still in use, especially linking field devices to their control devices.
Regardless, the field devices are typically electrically isolated from the rest of the control system. In the case of the electric power plant, for example, this is necessary to prevent harm to the control devices, workstations and other plant equipment—not to mention the plant personnel—from the high voltages and currents existing where the power is actually generated. The reverse is likewise true: static discharges or standard line voltages present in the plant control room could knock out field devices, or worse, if circuited back to the power-generating equipment.
The art suggests a number of mechanisms for transferring control and data signals between control systems and field devices across an electrical isolation barrier. These include optical and capacitance-based mechanisms, though, the most popular form of isolation relies on inductance, typically, as embodied in transformers.
Transformer-based isolation has several advantages over competing mechanisms. Among these are lower cost, durability and reliability. However, when utilizing conventional circuits such as shown in FIG. 1 , the bandwidth of the data transfers is limited—unless resort is had to unduly large transformers. This can be problematic in applications where power or physical space are limited.
An object of this invention is to provide improved methods and apparatus for communication across an isolation barrier. A more particular object is to provide such methods and apparatus as are based on inductive transfer across the barrier and are suitable for use with process, industrial, environmental and other control systems.
Another object of the invention is to provide such methods and apparatus as are suited for use in transferring information between control devices that normally rely on analog signaling, such as the industry standard FoxComm™ and HART™ protocols, to communicate control, data and other information signals.
A further object of the invention is to provide such methods and apparatus as can be implemented with minimum consumption of power and minimum use of physical space. A related object is to provide such methods and apparatus as do not generate undue heat.
Still yet a further object is to provide such methods as can be implemented at low cost, using existing off-the-shelf technologies.
SUMMARY OF THE INVENTION
The foregoing are among the objects achieved by the invention, one aspect of which provides improved apparatus for transferring information between control devices over a galvanic or other isolation barrier. The apparatus has a modulator that generates a pulse width modulated (PWM) signal from a frequency shift keying (FSK), or other frequency modulated (FM) signal, containing information being transferred by a first control device, e.g., a controller. A transformer or other such circuit element inductively transfers the PWM signal across the isolation barrier, where it is demodulated to analog form for application to a second control device, e.g., a field device (or controller)
Further aspects of the invention provide apparatus as described above in which the PWM signal is generated from an FSK signal output by a modem, e.g., that is coupled to a control device (such as a controller) generating information to be transferred. Such an FSK signal can be compatible with a FoxComm™, HART™ or other industry standard or proprietary FSK or FM protocol.
Still further aspects of the invention provide apparatus as described above in which the PWM signal is demodulated by a low pass filter. Such a filter can be constructed, for example, using an resistor capacitor (RC) circuit. A buffer is utilized, according to related aspects of the invention, to modify the impedance of the RC circuit for output to the field device.
By way of example of the foregoing, digital signals representing command and data output by a controller are converted to analog FSK form by a modem. The analog signal is applied to a pulse width modulator that generates a fixed-frequency PWM signal having pulses whose widths vary in accord with the amplitude of the FSK signal and, therefore, in accord with the controller output. The PWM signal is carried over the isolation barrier by a transformer and routed to a low pass filter that demodulates it back into analog FSK form. The FSK signal can be routed to a field device, e.g., via an intelligent transmitter.
Further aspects of the invention provide apparatus as described above equipped for transferring information from the second control device (e.g., the field device) to the first control device (e.g., the controller). A modulator generates an amplitude modulated (AM) signal from an FSK signal embodying the information generated by the second device for transfer. That AM signal utilizes a carrier component that is based on a fixed duty cycle output of the pulse width modulator used to transfer information in the reverse direction. That AM signal is transferred over the isolation barrier by the transformer, where it is demodulated to FSK form for application, e.g., to a modem and, then, to the controller.
By way of example, an FSK data signal received from a field device is multiplied by an AND gate with the output of the pulse width modulator, which is set at a fixed width duty cycle when the controller is not transmitting. The resulting AM signal is transmitted over the transformer to the control side, where an envelop detector demodulates it back to FSK form for further demodulation to digital, by the controller's modem, and processing by the controller.
Further aspects of the invention provide individual control system devices constructed and operated in accord with the foregoing.
Apparatus configured and operating as described above have the advantage of permitting information encoded in analog FSK signals (and, in turn, encoded in PWM and AM signals) to be transmitted between electrically isolated components of a control system over small, low power transformers.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be attained by reference to the drawings, in which
FIG. 1 depicts a prior art configuration for transmitting information over an isolation barrier between a control device and a field device;
FIG. 2 depicts a system according to the invention for transmitting frequency shift keying (FSK) signals that are, in turn, encoded in PWM signals over an isolation barrier from control device to field device;
FIG. 3 depicts the system of FIG. 2 , additionally showing the transmission of FSK signals that are, in turn, encoded in AM signals over the isolation barrier from the field device to the control device;
FIGS. 4A-4C depicts the architecture of an application specific integrated circuit (ASIC) embodying a communications system according to the invention;
FIG. 5 depicts a dual tone asynchronous block of the ASIC of FIGS. 4A-4C ;
FIG. 6 depicts an asynchronous frame supported by the dual tone asynchronous block of FIG. 5 ;
FIG. 7 depicts a relationship between NRZ and dual tone FSK as supported by the dual tone asynchronous block of FIG. 5 ;
FIG. 8 depicts a Hart dual tone signal of the type generated by a dual tone asynchronous block of FIG. 5 ;
FIG. 9 depicts a channel block diagram for the dual tone asynchronous block of FIG. 5 ;
FIG. 10 shows universal serial transmitter and receiver block level diagrams for the dual tone asynchronous block of FIG. 5 ;
FIG. 11 illustrates the duration of signal peaks and valleys in a dual tone signal of the type generated by an FSK modulator of the dual tone asynchronous block of FIG. 5 ;
FIG. 12 depicts re-evaluation of a dual tone signal in a dual tone asynchronous block of FIG. 5 ;
FIG. 13 depicts a dual tone generation circuit in a dual tone asynchronous block of FIG. 5 ;
FIG. 14 is a block diagram of the continuous autocorrelation method in a dual tone asynchronous block of FIG. 5 ;
FIG. 15 illustrates the relation between the dual tone input tone, its 28-bit delayed signal tone, their XOR comparison for a HART signal of the type generated by dual tone asynchronous block of FIG. 5 ;
FIG. 16 depicts counter ranges and continuous autocorrelation during generation of a HART signal of the type generated by dual tone asynchronous block of FIG. 5 ;
FIG. 17 depicts integrate and dump circuitry of a dual tone asynchronous block of FIG. 5 ;
FIG. 18 depicts a FSK dual tone signal suffering from low frequency loss and then from high frequency loss of carrier;
FIG. 19 depicts a count waveform at the integrate and dump circuit of FIG. 19 resulting from the losses depicted in FIG. 18 ;
FIG. 20 is a block diagram of the PWM circuit in a dual tone asynchronous block of FIG. 5 ;
FIG. 21 depicts a PWM waveform generated by a dual tone asynchronous block of FIG. 5 ;
FIG. 22 depicts a FIR filter algorithm in a dual tone asynchronous block of FIG. 5 ;
FIG. 23 depicts trapezoidal waveform that emerges from the FIR filter of FIG. 22 ;
FIG. 24 depicts a loopback configuration in a dual tone asynchronous block of FIG. 5 ;
FIG. 25 is a block diagram of a pin controller of a dual tone asynchronous block of FIG. 5 ;
FIG. 26 depicts a mapping of the I/O bit, Inversion bit and I/O mux control bits for a pin controller for FIG. 25 ; and
FIG. 27 depicts IO pin control registers in dual tone asynchronous block of FIG. 5 .
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
FIG. 1 illustrates a prior art system for galvanic isolation of the components of a process control system. Here, a control device 12 (e.g., a controller) generates a digital signal for controlling a field device 14 . Those signals are transmitted to a modem (which may be integral to the control device or, more typically, coupled to it via a serial port) and modulated to analog form, more specifically, an frequency shift keying form, which can be a “tone” signal in the range of 1-5 kHz. A transformer 18 is used to pass the FSK signal across an isolation barrier 20 from the “control side” of the system to the “field side,” where it can be applied to the field device directly, via a modem, or otherwise. By a similar mechanism, data (or other control) signals generated by the field device 14 are passed back over the transformer in FSK form, demodulated to digital form and routed to the control device 12 for processing. A drawback of systems of the type illustrated in FIG. 1 is the cost, large size and high power requirements of the transformers required to transfer the FSK signals across the isolation barrier.
FIG. 2 illustrates a system according to the invention for transmitting control, data and other information across an isolation barrier from a control device 12 to a field device 14 . The illustrated embodiment is described in the context of process control, though those skilled in the art will appreciate that the invention has application in industrial, environmental and other control systems as well.
Like numbered elements in FIGS. 1 and 2 pertain to like devices that perform like functions. Thus, the system of FIG. 2 includes a first control device, such as controller 12 , that generates a signal embodying command, data or other information (hereinafter, a “control” signal) for transfer to a second control device, such as field device 14 . By way of non-limiting example, in the illustrated embodiment, controller 12 can be any type of control device, such as a controller, workstation, or the like. By way of further ion-limiting example, field device 14 can be any of an actuator-type or sensor-type field device, of the “smart” variety or otherwise, available from the assignee hereof, or otherwise.
Of course, those it will be appreciated that the invention has application in the transfer of information between any variety of control devices. Thus, in further embodiments of the invention, the first and second control devices can be any of workstations, field controllers, field devices, smart field devices, or other device for any of industrial, manufacturing, service, environmental, or process control. Moreover, though the illustrated devices 12 , 14 are in a control relationship, those skilled in the art will appreciate that the isolation mechanisms described herein can be utilized for communications between any devices in a control environment, regardless of whether those devices control one another, are controlled by one another, are peers or otherwise.
In the illustrated embodiment, the control signal generated by device 12 is in digital form (as graphically depicted by square wave 12 a ). This can be any proprietary or industry standard digital signal embodying desired command, data or other information generated by the device 12 . The control signal is modulated to analog form (as graphically depicted by sine wave 16 a ) by modem 16 ′ in any manner, proprietary or otherwise, known in the art. By way of non-limiting example, in the illustrated embodiment, the analog form is a frequency shift keying (FSK) signal defined by “tones” in the range of 1-5 kHz range that are superimposed on a 4-20 mA current signal, in the manner of industry standard FoxComm™ and HART™ protocols. Of course, those skilled in the art will appreciate that the invention has application in the transfer of other FSK and/or other frequency modulated signals, as well. This FSK (or tone) signal is superimposed on a 40
Pulse width modulator 22 converts the FSK control signal to a pulse width modulated (PWM) form, as graphically depicted by wave 22 a . Such conversion can be accomplished using any proprietary or industry standard PWM circuitry and techniques known in the art and, preferably, is accomplished as described below. The modulator 22 can operate at any frequency suitable for the purposes hereof and, by way of non-limiting example, in the illustrated embodiment operates at 1 MHZ.
With further reference to FIG. 2 , the PWM-encoded control signal is applied to transformer 18 ′ for transfer across the isolation barrier. The isolation barrier constitutes any physical barrier across which isolation is desired. This can be a physical barrier, such as a quartz, glass, ceramic or other separation medium. It can also be a “virtual” barrier, such as an equipment boundary, plant boundary, and/or geographic point across which galvanic or other electrical (and physical) protection is desired. Regardless, the barrier 20 need only permit the inductive transfer of electromagnetic waves, e.g., of the type generated between the primary and secondary coils of a transformer 18 ′ or other inductive circuit elements.
Transformer 18 ′ comprises any transformer or other combination of devices suitable for inductive transfer over the isolation barrier. This can be a transformer of the type conventionally used in the process and other control arts for such purpose. Preferably, however, it is a smaller, less costly and uses less power than traditional transformers that are used to transfer FSK signals directly (i.e., without encoding in PWM form). By way of non-limiting example, transformers suitable for the inductive transfer of PWM signals encoding control, data and other information in embodiments of the type shown in FIG. 2 have inductance in the range of 600 μH-700 μH and, more preferably, 750 μH-900 μH and, still more preferably, 1000 μH-1500 μH. Suitable such transformers 18 ′ of the type available, by way of non-limiting example, from Pulse Engineering, Inc., are suitable for this purpose.
PWM-encoded control signals inductively transferred by the transformer 18 ′ across the isolation barrier are graphically depicted by wave 22 b in the drawing. These signals are demodulated back into analog form and, particularly, into FSK form, in any manner, proprietary or otherwise, known in the art. In the illustrated embodiment, by way of non-limiting example, this is accomplished through use of a low pass filter comprising a combination of resistor 24 and capacitor 26 . In the illustrated embodiment these are arranged to pass the low frequency components in the range of 0-10 kHz and, preferably, 1 kHz-5 kHz, though, those skilled in the art will appreciate that other ranges and/or combinations of components can be used to provide the desired demodulation.
The demodulated signal is graphically depicted by sine wave 26 a . The impedance of the analog signal is adjusted, in the illustrated embodiment, by buffer 28 of the type conventionally used in the art for this purpose. A Transmit Enable signal is applied to the buffer 28 during periods when information is being transmitted from the control device 12 to the field device 14 .
The impedance-adjusted signal is applied to the field device 14 directly, via a modem, or otherwise, over a conventional transmit/receive loop. In the illustrated embodiment, by way of non-limiting example, this loop comprises capacitor 30 , resistor 32 and power source 34 , which are arranged in the manner shown and whose respective values are selected in the conventional manner in the art to effect transfer of the analog control signal to the field device 14 and receipt of data generated by it.
The illustrated embodiment demodulates the PWM-encoded control signals into an analog form substantially the same as the format output by modem 16 . Thus, for example, where analog control signal 16 a is in a FoxComm™ format, signal 26 a is demodulated into that format, as well. Alternate embodiments of the invention demodulate the PWM-encoded control signals into alternate analog formats (e.g., a HART format) or into digital formats, e.g., as determined by the needs of the field device to which the demodulated signal is to be applied.
FIG. 3 illustrates circuitry utilized in accord with the apparatus of FIG. 2 for transmitting data and other information across the isolation barrier 20 from field device 14 to control device 12 . Analog FSK signals containing that data and other information (hereinafter, device signals) generated by the field device in the conventional manner are received in the aforementioned loop, e.g., via direct application by the field device 14 , via modem or otherwise. In a preferred embodiment, these signals originate in digital form at the field device 14 and are modulated to analog by a modem, not shown, to analog. As above, the analog signals can be in the range of 1 kHz-5 kHz and can encode the data and other information in accord with proprietary or industry standards. In the illustrated embodiment, by way of non-limiting example, the analog signals are FSK signals in accord with the standard FoxComm™ or HART™ protocols.
The analog signals received from the field device 14 are graphically depicted by waveform 14 a . These signals are passed through a band pass filter 36 when the control device 12 is not generating and transmitting control signals and, thus, when the illustrated Transmit Enable signal is not asserted. The band pass filter 36 removes frequency components of the analog device signals outside the range 1 kHz-15 kHz and, preferably, outside the range 3 kHz-12 kHz. This has the effect of removing noise from the signal.
The filtered analog device signals are subsequently used to modulate the amplitude of a carrier signal. Any carrier signal can be used for this purpose. However, in the illustrated embodiment, by way of non-limiting example, the output of the modulator 22 is used. To this end, the modulator 22 is set to a fixed duty cycle during periods when the control device 12 is not generating and transmitting control signals across the isolation barrier 20 . Any duty cycle can be used, though, in the illustrated embodiment, a duty cycle of 20%-80% and, preferably, approximately 50% is used. At this latter value, by way of example, the modulator 22 generates a 1 MHZ signal whose pulses have a width equal to 50% of the pulse period. This signal is, of course, inductively transferred over the barrier 20 by the transformer 18 ′, thereby, permitting its use as a carrier, when the control device 12 is not generating and transmitting control signals.
Modulation of the carrier amplitude to encode the field device's (or transmitter's) FSK signal can be achieved in any manner known in the art. In a preferred embodiment, by way of non-limiting example, it is accomplished by multiplying or logically AND'ing the FSK device signal with the carrier, i.e., the modulator output, using AND gate 38 . The resulting amplitude modulated signal, which is graphically represented by waveform 38 a , is applied to the transformer 18 ″ for inductive transfer over the barrier 20 to the control side.
Like transform 18 ′, transformer 18 ″ comprises any transformer or other combination of devices suitable for inductive transfer over the isolation barrier. This can be a transformer of the type conventionally used in the process and other control arts for such purpose, again, however, smaller, less expensive and using less power than transformers traditionally used to carry FSK signals across an isolation barrier. By way of non-limiting example, transformers suitable for the inductive transfer of the amplitude modulated device signals have inductance in the range of 600 μH-700 μH and, more preferably, 750 μH-900 μH and, still more preferably, 1000 μH-1500 μH. Suitable such transformers 18 ″ of the type available, by way of non-limiting example, from the same sources as transformer 18 ′
Amplitude modulated device signals inductively transferred by the transformer 18 ″ across the isolation barrier 20 are graphically depicted by wave 38 b in the drawing. This signal is demodulated back into analog FSK form in any manner, proprietary or otherwise, known in the art. In the illustrated embodiment, by way of non-limiting example, this is accomplished through use of an envelope detector 40 with a time constant of between 1 μS and 2.5 μS and, preferably 1.5 μS. A preferred envelope detector comprises an capacitor of 220 pf and a resistor 6.81 kΩ configured as shown. Those skilled in the art will appreciate that capacitors and resistors of other values may be utilized to achieve the desired time constants.
The resulting analog signal, encoding the data and other information from the original device signal, is depicted by waveform 40 a . This can be applied directly to the control device 12 , via modem or otherwise.
In the illustrated embodiment, modems 16 ′, 16 ″, pulse width modulator 22 are embodied in a communications controller applications specific integrated circuit 42 , which includes circuitry for performing other communications functions as well. That element 42 is referred to, alternatively, as the “ASIC” or “CommControl ASIC” in the text below. Those skilled in the art will, of course, appreciate that the invention can be implemented in other form factors, whether hardware or software, and with circuit element different than those shown in the drawing and described below.
The CommControl ASIC, as well as one or more other components illustrated in FIGS. 2 and 3 (apart from controller 12 and field device 14 ) can be embodied in any variety of input/output circuits utilized to communicate between process, environmental or other control devices. Such circuits can be integral with any such a control device (e.g., a controller) or embodied in a separate communication device. In the illustrated embodiment the ASIC and aforementioned components are embodied in an input/output module that is electrically coupled to, but physically separate from, the control devices 12 and 14 . Such module is designated by the grayed regions of FIGS. 2 and 3 .
The illustrated input/output module includes, in addition to the circuitry discussed above, circuitry that transfers power across the isolation barrier to drive the field side of the input/output module as well as to drive the field device 14 (and associated transmitter) itself Such power circuitry is illustrated in the drawing as including a DC/DC converter, a transformer and a rectifier, all coupled in the manner shown and configured and operated in the manner conventional to the art. It will, of course, be appreciated that any other power transfer circuitry known in the art may be used for this purpose.
The illustrated input/output module includes additional circuitry that converts and transfers to the controller 12 a digital signal generated from the 4-20 mA current signal communicated between the input/output module and the field device 14 . That current signal is traditionally referred to as the “analog” Component of a FoxComm™ or HART™ signal, but shall be referred to a “current signal” to avoid confusion with the FSK component (which is traditionally but somewhat erroneously referred to as a “digital” signal, but which shall continue to be referred to as an analog signal elsewhere herein). The additional circuitry includes an A/D converter, which converts the current signal to digital for transfer across the isolation barrier via the optical isolator (comprising a photo diode and transistor opposed across the barrier). The digital signal is routed to a processor local to the input/output module, which can format the signal for transfer to the controller 12 . In addition to providing the aforementioned function, the processor coordinates and control operations of the other components of the input/output module, all in the manner traditional in the art.
While the circuitry described immediately above converts and transfers to the controller 12 a digital signal generated based on the milliamp current signal from the field device 14 , those skilled in the art will appreciate that corresponding circuitry (not shown) can be provided to transfer a milliamp current to the field device from controller. Such corresponding circuitry utilizes a digital to analog converter and a voltage to current converter in place of the A/D converter of the illustrated circuit, all in the conventional manner.
Modem 16 and pulse width modulator 22 are discussed below in connection with the DUAL TONE feature of the ASIC. In the illustrated embodiment, this provides asynchronous FoxComm™ and HART™ communications through eight independent channels. High frequency pulse width modulation encoded transmission supports RF transformer galvanic isolation with minimal external circuit support and cost. In addition, ASIC 42 includes
An 80186-compatible stored program microprocessor controller, which may be switched into slave mode to accommodate an external master controller and for external emulation during software development and debugging. High speed synchronous serial communications capability through two independent HDLC channels. Asynchronous serial communications capability through three UART devices (one is a standard console, and two are highly buffered “fastports”). Field Analog Digital Input and Output Controller (FIOC) interacts with intelligent external analog and digital circuits for measurement and control. The FIOC supports state-machine controlled SPI interfaces that need minimal microprocessor intervention. External I/O pin programmability enables one same CommControl ASIC to be used in connection with interface devices for a diversity of different hardware product types. Support for additional external peripheral, such as an Ethernet controller. Scan test capability for high fault coverage and reliability.
FIGS. 4A-4C illustrates the blocks that provide each of the foregoing functions. The HDLC, UART, DUAL TONE and FIOC blocks are peripherals in the IO space of the v186 microprocessor. Flash and SRAM memories are external to the ASIC. Building a process field bus module out of the ASIC requires external RS-244 drivers to connect to the HDLC wire, as well as appropriate external A/D and D/A converters for analog FBMs. External support circuitry is also required to handle the galvanic isolation and conversion between dual tone and pulse width modulated data in FoxComm and HART applications.
Building a basic hardware system with the CommControl ASIC 42 requires only two external memory blocks, one flash and the other one SRAM (the latter typically implemented in two ICs). The illustrated ASIC 42 is preferably used in connection with interface devices known as “Field Bus Modules” or “FBM”s (both, tradenames of the Assignee hereof), available from the Assignee hereof, though the ASIC 42 can be used with a variety of other process control devices and, more generally, control devices.
The two independent HDLC serial communication controllers (HSSC) provide high speed synchronous serial communications capability to the CommControl ASIC. They are referred as HDLC 0 and HDLC 1 . Messages of arbitrary length (preferably in bytes) may be exchanged with a remote host. HDLC transfers typically occur under DMA control, leaving the microprocessor free to attend other tasks. Outgoing HDLC messages must be assembled first in external SRAM. For transmission, the HDLC controller makes DMA requests to the processor in order to fetch the message from memory. The controller interrupts the processor when the message transmission has been completed. For reception, the HDLC controller also makes DMA requests to the processor, in order to store the incoming message in external SRAM. The controller interrupts the processor when the message reception has been completed. DMA transfers support only half duplex operation. Other full duplex non-DMA transmission and reception modes are also available.
Each one of the three UARTs is a standard PC serial port peripheral. They are referred as UART0 (console), UART1 and UART2 (“fastports”). Of these, only the console is equipped with a full set of modem signals. The fastports are designed for maximum software efficiency, while retaining compatibility with the industry standard PC serial port specifications. Each UART may assert an independent interrupt signal. In the console UART, both transmitter and receiver have a sixteen position FIFO for data buffering. The fastports have a sixty four position FIFO in both transmitter and receiver. The UARTs are general purpose devices, and UART1 and UART2 are intended for fast local inter-board communication in double and triple redundant modules.
There are eight independent DUAL TONE FoxComm/HART asynchronous communication controllers. They are referred as ASYN 0 , ASYN 1 , . . . ASYN 7 . Their inputs and outputs are routed through any of the 32 general purpose IO_SIG pins, as configured in the IO PIN Control Register. Each controller consists of a transmitter and a receiver. The transmitter consists of an asynchronous device with a sixteen position FIFO to store data bytes that are converted into serial frames flanked by a start and a stop bit. The frames are fed to a dual tone modulator. The resulting dual tone FSK signal is fed to a Pulse Width Modulator (PWM. Either the serial frames, the FSK or the PWM signals may be transmitted out. The receiver consists of an FSK dual tone demodulator, which converts FSK into asynchronous serial bit frames. The asynchronous serial frame is fed to a serial receiver that stores the received bytes in a 32 position FIFO. In both cases, the dual FSK tone may be programmed to conform to either the FoxComm I (IT1), the Fox-Comm II (IT2) or the HART protocol. The controllers may be selected to receive either FSK dual tone, or asynchronous serial frames (the latter is equivalent to a UART). The PWM option is intended to support small size high frequency external electromagnetic transformers for galvanic isolation.
The FIOC is a programmable peripheral capable of handling digital and analog input and output for process control. It is fully configurable, and interacts with external devices through a set of 32 programmable IO pins. The FIOC communicates with external devices using an SPI protocol. The SPI transactions may be placed under the control of dedicated state machines thus leaving the internal microprocessor free for other tasks. In addition, it offers status LED control, watchdog timeout and fail-safe protection.
The 80186 compatible microprocessor (B186) is a stored-program 16-bit microprocessor, with two DMA and six interrupt channels, three programmable timers, SRAM and PROM select decoding, and up to seven peripheral chip select decoding. The microprocessor is fully integrated inside of the ASIC. The V186 interacts with external SRAM and PROM for instruction fetching and storage. A more complete understanding of the V186 maybe attained by reference to “Microsystem Components Handbook”, Intel Corporation, Santa Clara, Calif. 1985, chapter 3. Also “V186 Synthesizable HDL Core Specification and Data Sheet”, Rev 1.6 VAutomation Inc., Nashua, N.H., 1988. Also “V8086 Synthesizable HDL Core Specification and Data Sheet”, Rev 1.8 VAutomation Inc., Nashua N.H., 1988, the teachings of all of which are incorporated herein by reference.
The ASIC may be operated in two different processor modes. In the normal (master) mode, the internal v186 is in control of the HDLC, UARTs, DUAL TONE and FIOC peripherals, and the bus signals are brought out for memory transactions and also for visibility. In the alternate (slave) mode, the internal v186 is turned off line (by asserting the HOLD pin high), and the HDLC, UARTs, DUAL TONE and FIOC peripherals are under the control of an external bus master for emulation, debugging and diagnostics.
The operation mode is selected with the HOLD input pin. For normal (internal master) mode, the HOLD pin must be either low or open. For external v186 (slave) mode, the HOLD pin must be high.
The ASIC may be operated in two different processor modes. In the normal (master) mode, the internal v186 is in control of the HDLC, UARTs, DUAL TONE and FIOC peripherals, and the bus signals are brought out for memory transactions and also for visibility. In the alternate (slave) mode, the internal v186 is turned off line (by asserting the HOLD pin high), and the HDLC, UARTs, DUAL TONE and FIOC peripherals are under the control of an external bus master for emulation, debugging and diagnostics. The operation mode is selected with the HOLD input pin. For normal (internal master) mode, the HOLD pin must be either low or open. For external v186 (slave) mode, the HOLD pin must be high.
Characteristics of the ASIC 42 are overviewed in the table below:
CONCEPT
CHARACTERISTIC
COMMENTS
CLOCK RATES
Microprocessor:
The U_CLK pin drives the internal
Nominally 20 MHz
microprocessor clock. Its minimum frequency is
16 MHz. May be run at higher frequency.
HDLC 2 MHz
The C_CLK pin drives the HDLC controller,
and DUAL TONE logic. Its nominal frequency
is 16 MHz, which is divided internally by 8 to
achieve 2 Mbit/sec. An 8.6 MHz clock may be
used instead for 268.75 Kbit/second HDLC
(divide by 32).
INTERNAL
Compatible with
Internal processor may be disabled to allow use
PROCESSOR
INTEL 80186.
of an external processor for emulation, debug-
ging, test, or even normal operation. Address-
ing capability is up to 20 bits (up to 1 Mbytes of
SRAM and 1 Mbytes of ROM).
DIGITAL/ANA-
Fully configurable.
Software-programmable as inputs/outputs,
LOG IO PINS
with or without logic inversion. Pins have full
matrix connectivity to select any internal digi-
tal/analog blocks, as well as DUAL TONE blocks.
WATCHDOG
Bit must be toggled at
If processor fails to toggle watchdog keep alive
TIMEOUT
least every 60 msec.
bit, it will be reset.
FAIL SAFE
If enabled, analog and
Caused by watchdog timeout or by control
PROTECTION
digital outputs go to
processor command.
a predefined condition.
STATUS AND
“Red and green” LED
CHANNEL LED
signals to indicate the opera-
INDICATOR
tional status of the module.
SIGNALS
LEDsignals to indicate
channel on-off status.
HDLC
Two independent HDLC
Point to point only. No SDLC loop mode. The
controllers,
speed is nominally 2 Mbit/sec, with other
options possible. Supports block DMA
communications.
PROCESSOR
(INT)4-0 used by internal
Interrupt lines support the DMA transmission
INTERRUPTS
peripherals in fully nested
and reception of HDLC messages. The interupts
interrupt mode. INT 5
occur upon the reception of a whole message
available for extemal
into memory, or after the transmission of a
device.
whole message out from memory. Also UARTs
may interrupt processor.
PROCESSOR
DREQ0 and DREQ1
DMA request signals support DMA block
DMA
transmission and reception of HDLC frames.
The processor is not burdened during the
HDLC transfers.
CONSOLE
Three independent
One industry standard PC serial port UART
SERIAL PORTS
UARTs.
with full set of modem signals, to be used as a
console, or to support an infrared port. Two
other “fastport” UARTs without modem signals,
designed for compatibility plus software
efficiency for inter-board communication.
FOXCOMM/
Eight independent
Inputs and outputs fully configurable. Supports
HART
channels
high frequency PWM to drive small external
RF transformers. May be operated as simple
UART.
Pinouts of the table are presented in the table below:
INT(1)
NAME
IO
RES
DESCRIPTION
(ADDR) 19-0
IO
Address. Memory and IO address for an address space of 1M
bytes. It is an output for normal (internal v186) mode, and its
(least significant eight bits (ADDR)7-0() are an input for
external) v186 mode.
ALE
IO
Address Latch Enable. When asserted high, the contents of the
DABUS are latched into the internal address latch. It is an output
for normal (internal v186) mode, and an input for external 186 mode.
(ARX) 2-0
I
UP
Asynchronous Receive. Pins with subindex 0, 1 and 2 are the
serial data inputs for UART0 (console), UART1 and UART2,
respectively.
(ATX) 2-0
O
Asynchronous Transmit. Pins with subindex 0, 1 and 2 are the
serial data outputs for UART0 (console), UART1 and UART2,
respectively.
BHE_N
IO
Byte High Enable. Asserted low for byte bus transactions in the
high byte of a 16-word (odd byte address). It is an output for
normal (internal v186) mode, and an input for external v186 mode.
C_CLK
I
Communications Clock. This is the clock that drives the HDLC
channels and DUAL TONE block. It is nominally 16 MHz.
(CHAN_IND) 15-0
O
Channel Status Indicators. Used to control external channel
LEDs. See Table VII.3 on page107.
CLK_OK_N
I
Clock OK. Normally low. When high it forces LED_G low
(green LED turns off) and LED_R high (red LED turns on), even
if the master clock U_CLK has stopped.
CTS_N
I
UP
Clear To Send. Modern input to console UART. Asserted low.
(DABUS) 15-0
IO
UP
Data-Address Bus. Bidirectional multiplexed address and data
bus. The LSB corresponds to the LSB of internal registers.
DCD_N
I
UP
Data Carrier Detect. Modem input to console UART. Asserted
low.
(DIAG_SIG) 7-0
IO
DOWN
Input/Output Signals. These signals are used for discrete input
and output diagnostics.
(DMAREQ) 1-0
O
DMA Request. A high in either of these signals indicates a DMA
request posted by their corresponding HDLC. In normal (internal
v186) mode, these signals echo internal activity and may therefore
be used for testing. In external v186 mode, these signals
must be connected to the corresponding external microprocessor
inputs.
DSR_N
I
UP
Data Set Ready. Modem input to console UART. Asserted low.
DTR_N
O
Data Terminal Ready. Modem output from console UART.
Asserted low.
GCLKOUT
O
General Clock Out. The output signal on this pin is program
selected from several internal sources in the SYSTEM REGISTER
(see Table 1.5). The sources are the console and UART1
UART2 baud clocks, or the HDLC DPLL clocks.
HBYTES
O
High Bytes. Used to select the high byte external SRAM.
Asserted high.
HOLD
I
DOWN
Hold. When asserted high, the internal v186 is forced into hold
(slave) mode, stopping the program execution. All the relevant
v186 microprocessor pins change direction, allowing an external
microprocessor to become bus master. This signal has an internal
pulldown, and must be held low (or left open) during normal
operation.
HOLDA
O
Hold Acknowledge. Asserted high when internal v186 acknowledges
the HOLD pin request, and relinquishes the bus to an external master.
(INT)4-0
O
Interrupt Request. A high in either of these signals indicates an
interrupt request by their corresponding HDLC or UART blocks
(see Table I.4). In normal (internal v186) mode, these signals
echo internal activity and may be therefore used for testing. In
external 186 mode, these signals must be connected to the corre-
sponding external microprocessor inputs.
INTERRIN
I
DOWN
Interrupt Input. This input drives the internal v186 INTER-
RUPT 5 input. May be used by any peripheral exernal to the
ASIC (such as an Ethernet controller) to interrupt the internal
processor.
(IO_SIG) 31-0
IO
DOWN
Input/Output Signals. These are the signals used to talk and
listen to external digital and analog input and output devices. They
are also used for FoxComm and HART. These signals are soft-
ware-configurable, and maybe routed to any of the internal digital
and analog blocks in the ASIC.
See “PIN MULTIPLEX CONTROLLER” on page103.
LBYTES
O
Low Bytes. Used to select the low byte external SRAM. Asserted
high.
LCS_N
OZ
Low Chip Select. This signal is asserted low whenever a mem-
ory reference is made to the lower memory portion of the address
space. Drives the external SRAM chip select. High impedance in
external 186 mode.
LED_G
O
Green LED. This signal is asserted high to turn on the external
green LED.
LED_R
O
Red LED. This signal is asserted high to turn on the external red
LED.
MCS_N
OZ
Memory Chip Select. This signal is asserted low to select an
external memory device (such as an Ethernet controller). It is
driven by the internal v186 MCS0_N output. This pin is at high
impedance in external 186 mode.
NMI
I
DOWN
Non Maskable Interrupt. This signal is asserted high to make a
non-maskable interrupt request to the internal v186. Must be held
low (or left open) during normal operation.
(PCS_N) 6-0
IO
Peripheral Chip Select. These signals are asserted low to select
the internal peripherals. pcs0 selects HDLC0, HDLC1, the system
register, console, UART1 and UART2. pcs1 selects the DUAL
TONE block. pcs2 selects AIOCB0, pcs3 selects AIOCB1, pcs4
selects the pin configuration and discrete I/O registers. pcs5
selects the pulse counter circuit logic. Pin pcs6 does not select
any internal peripherals, and is intended for selecting any future
(external peripherals. Pins pcs)5-0 are outputs for normal master
(internal v186) mode, and inputs for external 186 (slave) mode,
since they must be driven by the equivalent pins in the external
microprocessor. Pin pcs6 is a tristate output.
PS_CLK
O
Power Safe Clock. A constant frequency (400 KHz nominal) is
always present on this pin while the chip is powered up. Other-
wise, power has been removed from the chip, or a chip failure has
occurred. Derived from U_CLK by a programmable divide
constant (see Controls Power supply clock rate Table VII.3).
RD_N
IO
Read. Asserted low during a read cycle. It is an output for normal
(internal v186) mode, and an input for external 186 mode.
RESET_N
I
Master Reset. Assert this signal low to initialize the chip into a
known state. The pin must be held asserted at least four U_CLK
cycles for proper initialization of the v186 microprocessor.
RES186OUT
O
Reset Out. This signal becomes asserted high during any internal
v186 reset (this may be due to a watchdog timeout). This signal
also echoes assertions of the reset_n input. Alternatively, if
TREE_EN is high, this becomes the output pin for the NAND
tree test circuit.
RI_N
I
UP
Ring Indicator. Modem input to console UART. Asserted low.
RTS_N
O
Request To Send. Modem output from console UART. Asserted
low.
(RX)1-0
I
Receive. Pins with subindex 0 and 1 are the serial data inputs for
HDLC0 and HDLC1 respectively.
(RX_DIS)1-0
O
Receiver Disable. Pins with subindex 0 and 1 are asserted high to
turn off the external receive buffer corresponding to HDLC0 and
HDLC1 respectively.
SCAN_ENABLE
I
DOWN
Scan Enable. Must be tied low (or left open) during normal oper-
ation. This pin is only driven high during scan test, in order to
enable the flip flop scan chain, and to shift in serially a set of flip
flop states. A one clock evaluation is performed with this pin low.
This is followed by forcing this pin high again, to shift out the
resulting states for test analysis.
SCAN_TEST
I
DOWN
Scan Test. This pin must be tied low (or left open) during normal
system operation. This pin is set high during scan test of the
ASIC. This forces the internal flip flops to be driven by their
respective scan domain clock (C_CLK or U_CLK). It also forces
all bidirectional pins as outputs, eliminates all internal loops, and
removes the effect of internal signals on flip flop direct set and
clear.
(SLOT_ID) 4-0
I
UP
Slot Identification. Intended for hard-wiring a 5-bit code that
(low Ù)
identifies the printed circuit board environment and intended use
of the ASIC. This code may be read by the microprocessor. See
TableVII.3 on page107, Config/Status.
SRDYIN
I
UP
Synchronous Data Ready Input. When this input is deasserted
low, it causes the internal 186 to extend its memory cycle. In
addition, the SRDYOUT pin is also deasserted low. This pin must
be kept high or left open for normal operation. To be used by an
external peripheral that requires extended memory cycles.
SRDYOUT
O
Synchronous Data Ready Output. This output is deasserted low
for as long as an internal peripheral requires the microprocessor
to extend its memory cycle. It is also deasserted low if the
SRDYIN input is deaaserted low. Connect this pin to the SRDY
pin of an external 186 whenever the ASIC is used in external 186
mode.
(STATUS) 3-0
OZ
Microprocessor Status. Indicates the state of the internal v186
microprocessor. The code is detailed in Table I.3. High impedance
in external 186 mode.
TREE_EN
I
DOWN
Tree Scan Enable. Must be tied low (or left open) during normal
operation. Assert this pin high to observe NAND tree test output
in RES186OUT.
(TX) 1-0
O
Transmit. Pins with subindex 0 and 1 are the serial data outputs
for HDLC0 and HDLC1 respectively.
(TX_EN) 1-0
O
Transmit Enable. Pins with subindex 0 and 1 are asserted high to
turn on the external transmitter driver corresponding to HDLC0
and HDLC1 respectively.
U_CLK
I
Microprocessor Clock. This is the master clock. It drives the
internal v186 microprocessor, as well as other IO components. It
is nominally 20 MHz. This clock's frequency must be greater or
equal than the frequency at the C_CLK pin.
UCS_N
OZ
High Chip Select. This signal is asserted low whenever a memory
reference is made to the upper memory portion of the address
space. Drives the external FLASH chip select. High impedance in
external 186 mode.
WR_N
IO
Write. Asserted low during a write cycle. It is an output for
normal (internal v186) mode, and an input for external 186 mode.
1. Internal pullup or pulldown resistor.
S3
S2
S1
S0
CODE
X
0
0
0
Interrupt Acknowledge
X
0
0
1
Read I/O
X
0
1
0
Write I/O
X
0
1
1
Halt
X
1
0
0
Instruction Fetch
X
1
0
1
Memory Read
X
1
1
0
Memory Write
X
1
1
1
Idle
0
X
X
X
Processor Cycle
1
X
X
X
DMA Cycle
INTERRUPT
DEVICE
INT 5
Available for external device.
INT 4
UART2
INT 3
UART1
INT 2
UART0 (Console)
INT 1
HDLC1
INT 0
HDLC0
The Dual Tone Asynchronous Serial Communication block (DTASC) of FIG. 4A is a computer peripheral capable of transmitting and receiving data bytes asynchronously as a serial-bit message. The message may be encoded in either of three signal encoding formats: NRZ bit frames, dual tone frequency shift keying (which may be used for example with the well-known Fox-CommI,™ FoxCommII™ or HART protocols), and high frequency pulse width modulated (PWM) signal (transmission only). The block contains eight identical channels, as illustrated in FIG. 5 , each of which may be independently programmed to operate in any of the aforementioned signal formats. The block contains a register set similar to a UART, but with no interrupt or modem handshake signal support.
The DTASC block contains eight identical and independent Dual Tone channels. Each channel may be programmed independently for FoxComm™ (IT1-IT2) or HART communications. 1 MHz Pulse Width Modulation (PWM) transmission supports external high frequency transformer isolation circuitry for both transmission and reception. The block has trapezoidal dual tone smoothing effect built into PWM transmission which adheres to HART specifications. Data may be transmitted as either asynchronous serial frame NRZ, dual tone, or modulated pulse width. Data may be received as dual tone, or serial frame NRZ. The transmitter is buffered with a 8 byte deep FIFO. Receiver is buffered with 16 byte deep FIFO. The block provides polled-based communication, with no interrupt support. A programmable baud generator divides input clock frequency for baud rates between 1/16 and 212. The block is fully programmable: 5-8 bit characters; even, odd or no parity; and, one or two stop bits. The block permits break generation and detection. The transmitter automatically adds and receiver automatically removes start, parity and stop bits. The block supports full duplex NRZ communications, as well as half duplex dual tone and PWM communications. System loopback mode is available for testing all eight channels, each channel transmitting to another channel and receiving from another channel.
Frame Format
Referring to FIG. 6 , for each of the three formats supported by the DTASC, the message unit is the bit-serial frame, which conveys from five to eight bits of information, plus optional parity bit. The frame consists of a start bit. The start bit (MARK) is immediately followed by the data bits (between five to eight) LSB first. These are followed by an optional parity bit (either even, odd or stick parity). The frame ends with a stop bit (SPACE).
Signal Format
Nrz Format
In this format a zero bit is represented by a low (SPACE) signal, and a one bit is represented by a high (MARK). Thus the signal is merely an unencoded frame, as shown in FIG. 6 .
Dual Tone Fsk Signal Encoding
The block supports three dual tone FSK formats: FoxCommI™, FoxCommII™ and HART. A dual tone FSK signal represents a zero or one bit with either a low or a high frequency tone (digital square wave). The bit data rate and tone frequencies are listed in the table below:
BAUD
NOMINAL MARK
NOMINAL SPACE
RATE
FREQUENCY - NRZ
FREQUENCY - NRZ
MODE
(Hz)
ONE (Hz)
ZERO (Hz)
FoxComm I
600
5,208
3,125
(IT1)
FoxComm II
4800
10,417
6,250
(IT2)
HART
1200
1,200
2,200
Effective peak to peak rise and fall time: 133 μsec
The relationship between NRZ and dual tone FSK is illustrated in FIG. 7 .
Pulse Width Modulated Signal Encoding
The PWM signal encoding is supported only for transmission. The intention of this format is to provide a high frequency encoded signal to drive external transformers for galvanic signal isolation. The high frequency reduces the size of the transformers, and results in more efficient external support circuitry. The dual tone FSK itself modulates the PWM, so that the FSK will be available after demodulating the signal in the secondary of the external transformer for remote transmission.
The PWM has a basic 1MHz frequency (1 μs period). The signal “on time” during this period is modulated within the range of
( 1 2 ± 3 16 ) u s = [ 5 16 , 11 16 ] u s in 1 16 u s
increments to encode the FSK. This results in a duty cycle of 50%±6.25% increments. Dual tone valleys are encoded with a lower “on time”, and dual tone peaks are encoded with a higher “on time”. In IT1 and IT2 modes, the PWM transitions vary abruptly from 31.25% to 68.75% duty cycle. In HART mode, the PWM transitions are encoded with a “staircase” trapezoidal dual tone signal, so that the “on time” changes in three discrete steps either above or three discrete steps below the “unmodulated” 50% duty cycle signal. See FIG. 8 .
Block Pinout
The DTASC block pinout is detailed in the table below:
NAME
I/O
DESCRIPTION
(ADDR) 2-0
I
Address. Used to encode the address of the
internal control, status or data registers.
CLK4MHZ
I
Clock 4 MHz. This is the primary clock from
which the baudrate is derived, as well as all
other clocks that generate the dual tone.
CLK16MHZ
I
Clock 16 MHz. This clock is used to generate the
PWM signal.
CS_N
I
Chip Select. Assert low to read or write the
internal registers and data FIFOs. The block is not
selected when deasserted high.
(DIN) 15-0
I
Input Data Bus. Contains the 8-bit data to be
written into the internal registers or transmit
FIFO (bits D)7(-D)0(). Bit 0 is the LSB, and
corresponds to the internal registers' LSB. The
width is sixteen bits to accomodate the Channel
Select Register, whose byte data is at an odd
address (the high byte of the corresponding 16-bit
word).
(DOUT) 15-0
O
Output Data Bus. Contains the 8-bit data read
from the internal registers or receive FIFO. Bit 0
is the LSB, and corresponds to the internal
register's LSB. The width is sixteen bits for a
reason similar to DIN.
HBYTE
I
High byte. Asserted high if a write transaction
occurs in the high byte.
LBYTE
I
Low byte. Asserted high if a write transaction
occurs in the low byte.
RD_N
I
Read. Must be asserted low to read out the
contents of internal registers or the receive FIFO
onto the output data bus DOUT.
READENABLE
0
Read Enable. Indicates to external drivers that the
HSSC is driving the bus on a register or receive
FIFO read.
RESET
I
Reset. Assert high to reset the internal logic to a
known state.
(RXSD) 7-0
I
Receiver Serial In. This is the block receiver
serial input.
SYSLOOP
I
System Loop. Places all eight channels inside the
block in loopback mode.
(TXON) 7-0
0
Transmitter On.This pin is high if the transmitter
is transmitting, low otherwise. This signal is low
during system loopback.
(TXQ) 7-0
0
Transmitter Serial Out. This is the block's
transmitter serial output
UCLK
I
Microprocessor Clock. This clock is typically
equal or faster than 16 MHz, to interface the
internal data FIFOs with a processor.
WR_N
I
Write. Must be asserted low to write the contents
of the DIN bus into the internal registers or the
transmit FIFO.
Register Address Map
The register map of the DTASC is detailed in the table below. All register bits are cleared during reset, unless specified otherwise. Registers are sixteen bits wide, and are either byte or word addressable. The CHANNEL SELECT REGISTER and the RECEIVER AND TRANSMITTER DATA BUFFER REGISTER are typically regarded as two separate byte addressable registers. Data in the RECEIVER AND TRANSMITTER DATA BUFFER REGISTER is mapped to the high byte at DIN 15 - 8 and DOUT 15 - 8 . Data in all other register's LSB is associated with the LSB of the I/O signals DIN 7 - 0 and DOUT 7 - 0 .
The contents of the CHANNEL SELECT REGISTER determine the particular channel that is addressed when writing or reading any other registers. Therefore, in order to write or read a particular channel, its channel number must be first written into the CHANNEL SELECT REGISTER.
HEX ADDRESS NAME RW BIT DESCRIPTION 0 CHANNEL SELECT RW D 7 -D 0 Write here a binary number to select the REGISTER corresponding channel. Any subsequent write or read references to registers in the address range 1-6 refer to the selected channel. Note: This is a byte wide register 1 RECEIVER AND RW D 7 -D 0 Write at this location the data to be TRANSMITTER DATA transmitted (LSB is first bit out). Read BUFFER REGISTER from this location the received data (First bit in is in LSB). Note: This is a byte wide register 2 LINE CONTROL REGISTER W D 15-13 Reserved for Test. (LCR) D 12 Loopback. D 11 Hysteresis. Set high to maximize hysteresis to recover the bit serial data from the continuous autocorrelator output. It is recommended to keep this bit high. D 10 Reserved. D 9-8 11 Reserved 10 HART. Set high for HART communications - 1200 baud 01 FoxII. IT2 mode communications - 4800 baud. 00 FoxI. IT1 mode communications - 600 baud. D 7 Integrate Dump. Set high to use integrate and dump circuit in the demodulator, instead of the continuous autocorrelation circuit. It is recommended to keep this bit low. D 6 Set Break. Set this bit high to send a break (continuous mark). D 5 Stick Parity. If 1, stick parity is enabled. With stick parity, frame parity bit is the logic complement of D 4 . D 4 Even Parity Select. If 0, odd parity, if 1 even parity. D 3 Parity Enable. If 0, no parity bit in frame, if 1, parity bit in frame. The parity bit is determined from the settings of D 5 -D 4 . D 2 Stop bits. If 0, one stop bit, if 1, two stop bits. D 1 -D 0 11 Character size 8 bits 10 Character size 7 bits 1 Character size 6 bits 0 Character size 5-bits 2 LINE STATUS REGISTER R D 10 Frame In Progress. (LSR) D 9 Tone Detect. D 8 Transmitter FIFO Full. D 7 Error in Receiver FIFO. D 6 Transmitter Empty. D 5 Transmitter FIFO Empty. D 4 Break Detect D 3 Framing Error D 2 Parity Error D 1 Overrun Error. D 0 Data Ready 4 BAUD DIVISOR LATCH RW D 15-0 16-bit word for baud rate selection. 6 MASTER CONTROL W D 15-11 Reserved REGISTER (MCR) D 10 Force pwm on transmitter idle. Set this bit high to force a 50% duty cycle PWM on transmitter idle. Set this bit low to passivate the PWM on transmitter idle. D 9-8 11 Reserved. 10 NRZ. Input and output are not encoded (not return to zero). 1 Tone. Input and output are encoded as dual frequency tone. 0 PWM. Output is modulated-width pulses. Input is dual frequency. D 7-6 Reserved D 5 Transmit Enable. Set this bit high to enable transmitter. D 4 FIFO Enable. D 3 Reset Transmitter - includes FIFO. D 2 Reset Receiver - includes FIFO. D 1 Transmitter FIFO Reset. D 0 Receiver FIFO Reset. 1. This symbol indicates that the bit is “push-button”. Writing the bit high initiates an action, and the bit is self-clearing.
Channel Select Register (Address 0 )
This is an 8-bit register, that points to the currently selected channel. It acts as an index for all read or write access to any other registers in the DTASC. This register is typically written first for channel selection.
Receiver And Transmitter Buffer Register (Address 1 )
The RECEIVER BUFFER REGISTER is a readonly byte register located at address 1 . The TRANSMITTER BUFFER REGISTER is a writeonly byte register located also at address 1 . Data bytes written into the TRANSMITTER BUFFER REGISTER are stored in a 8-level deep transmit FIFO of the selected channel, ready for transmission. However, transmission itself does not start until the Transmit Enable Bit in the MASTER CONTROL REGISTER is set high. Data received by the receiver is stored in a 16-level deep receive FIFO. The data is read out the FIFO through this RECEIVER BUFFER REGISTER.
Line Control Register (Address 2 )
This write-only 16-bit register determines the data frame format, in number of bits and parity. It also contains the bit used to send out a break character.
Loopback (D 12 )
Set this bit high to enable local loopback mode in the selected channel. In loopback mode, the transmitter dual tone FSK output is fed back to the receiver dual tone FSK input, and the TXON output is forced low.
Hysteresis (D 11 )
This bit affects the dual tone FSK receiver of the selected channel only. This bit should be normally high, so the continuous autocorrelator circuit output is evaluated with maximum hysteresis, which is the preferred configuration (see Section IV.7.6.1). If this bit is set low, hysterehysteresissis is considerably reduced. This bit is overriden by the Integrate Dump bit (D 7 ).
FoxComm/HART Protocol Selection (D 9 -D 8 )
These two bits determine the type of dual tone signal in the selected channel, whether FoxCommI, FoxCom-mII or HART. In addition to setting these bits properly, the appropriate baud rate has to be programmed into the BAUD DIVISOR LATCH.
Integrate Dump (D 7 )
This bit affects the dual tone FSK receiver of the selected channel only. This bit should be normally low, so the demodulator output is driven by the internal continous autocorrelator circuit, which is the preferred configuration. If set high, the demodulator output is instead driven by the internal integrate and dump circuit, which is normally used only for carrier detection. This bit overrides the Hysterisis bit (D 11 ).
Set Break (D 6 )
Set this bit high to force a low (mark) at the TXQ NRZ transmitter serial output. A continuous mark on the line with a duration equivalent to one full frame is considered a break character. The usage of this bit to send out a break character is as follows: Write an arbitrary byte to the TRANSMITTER BUFFER REGISTER Follow this immediately by setting the Set Break bit high, which forces the line low. Now poll the Transmitter FIFO Empty bit in the LINE STATUS REGISTER, until his bit is cleared low. When this occurs, clear the Set Break bit. This will send a break character with the desired duration.
Stick Parity (D 5 )
Set this bit high to enable stick parity in both transmitter and receiver. With stick parity enabled, the frame has a parity bit which is forced to be the logic complement of bit D 4 . The name of bit D 4 is Even Parity Select, even though there is no relation with even parity when used for stick parity. This mechanism allows to force the parity bit to any value, regardless of the data. Write this bit low to disable stick parity, which is the desired setting when normal even or odd parity is desired.
Even Parity Select (D 4 )
Write this bit high for even parity in both transmitter and receiver. In even parity, the number of high bits in the frame is even, including the parity bit Write this bit low for odd parity in both transmitter and receiver. In odd parity, the number of high bits in the frame is odd, including the parity bit This even/odd parity scheme applies when the Stick Parity bit D 5 is low. However, if the Stick Parity bit D 5 is high, D 4 is no longer an even parity bit. Instead, the parity bit in the frame is forced to be the logic complement of this bit D 4 .
Parity Enable (D 3 )
Write this bit high to enable parity in both transmitter and receiver. Parity may be odd/even parity, or stick parity. If this bit is low, parity is disabled, and the transmitter does not send a parity bit as part of the frame, and the receiver does not expect a parity bit as part of the frame.
Stop Bits (D 2 )
Writing this bit high forces the transmitter to send two contiguous stop bits. Writing this bit low causes the transmitter to send only one stop bit to end the frame.
Word Length (D 1 -D 0 )
This field determines the number of data bits in both the transmitter and the receiver, according to the table below:
Number of Bits D 1 -D 0 NUMBER OF BITS 11 8 10 7 01 6 00 5
Line Status Register (Address 2 )
This read-only register returns the status of the transmit and receive FIFO, as well as the indication of any possible receiver errors. A readout of this register indicates the receiver status pertinent to the data while it is still stored in the last position of the receiver FIFO (or receiver buffer). The last FIFO position is the one that stores the character to be read out next on the RECEIVER BUFFER register. Therefore, for valid receiver status information, this LINE STATUS REGISTER must be read before reading the RECEIVER BUFFER register. Reading this register clears the error conditions reported in bits (D 4 -D 1 ).
Frame In Progress (D 10 )
This bit is set high when the NRZ serial receiver detects a start bit and stays high for the duration of the valid frame. The bit is cleared when the stop bit is expected. This bit is valid in both NRZ and dual tone modes.
Tone Detect (D 9 )
This bit is set high when the demodulator in the receiver detects a legal tone. It is zero otherwise. To be legal, the tone must be in the vecinity of either one of the valid frequencies that represent one and zero, as determined by the integrate-and-dump circuit at the receiver. This bit is meaningless when the DTASC is used in NRZ signal encoding mode.
Transmitter FIFO Full (D 8 )
This bit is high if the transmit FIFO is full, and is low otherwise.
Error In Receiver FIFO (D 7 )
This bit is high if one or more byte characters still stored in the receive FIFO have been received either as a break frame, or with a framing error, or with a parity error. The bit is low if no FIFO position contains data received under any of these conditions.
Transmitter Empty (D 6 )
This bit is high if the transmit FIFO is empty and the transmitter is currently idle and not transmitting any frame. The bit is low otherwise. Alternatively, when the FIFOs are disabled, this bit is high if the transmit holding buffer is empty and the transmitter is currently idle.
Transmitter FIFO Empty (D 5 )
This bit is high if the transmit FIFO is empty, and is low otherwise. Alternatively, when the FIFOs are disabled, this bit is high if the transmit holding buffer is empty. Note that this bit may be high, while the Transmitter Empty bit (D 6 ) is low. This occurs when the transmitter is still in the process of sending out a frame, which was the last character read out of the FIFO (or transmit holding buffer if FIFO is disabled).
Break Interrupt (D 4 )
This bit is high if the data stored in the last position of the FIFO (or receiver buffer if FIFOs disabled) was received as a break character. A break character occurs if the receiver data input remains low during the equivalent duration of a frame. y
Framing Error (D 3 )
This bit is high if the data stored in the last position of the FIFO (or receiver buffer if FIFOs disabled) was received with a framing error. A framing error occurs when the frame is not terminated by at least one stop bit. This bit is low when no framing error has been detected.
It is a low (space) in the receiver frame that causes a framing error (when a high was expected). The receiver resynchronizes itself, treating this low in the frame as a start bit of a new frame.
Parity Error (D 2 )
This bit is high if the data stored in the last position of the FIFO (or receiver buffer if FIFOs disabled) was received with a parity error. This bit is low when no parity error has been detected.
Overrun Error (D 1 )
This bit is high if an attempt was made to overwrite the data that is now stored in the last position of the FIFO (or receiver buffer). This attempt occurs when a frame's reception is completed at a time that the receive FIFO (or data buffer if FIFOs disabled) is full. The data already stored is not overwritten, but the data that has been just received gets lost. This bit is low when no attempt to overwrite data occurred during the last frame reception.
Data Ready (D 0 )
This bit is high when the receive FIFO (or data buffer if FIFOs disabled) is not empty. This indicates that at least one received character may be read out. This bit is low when the FIFO (or data buffer) is empty, and there is no data to read.
Baud Divisor Latch (Address 4 )
This register determines the baud rate according to the following rule. The raw transmitter and receiver clock frequency is the ratio of the C_CLK clock input frequency divided by four and divided by the numeric equivalent of the binary number stored in the DIVISOR LATCH REGISTER The data (baud) rate of both transmitter and receiver is 1/16th of the raw clock frequency. Clearing this register causes the transmitter and receiver clock frequency to be equal to the C_CLK pin divided by four. The proper programming values for the three supported protocols are displayed in the table below, assuming a nominal C_CLK frequency of 16 MHz.
PROGRAMMED BAUD RATES FOR IT1, IT2 AND HART (C_CLK 16 MHZ) BAUD DIVISOR LATCH PROGRAM- BAUD MING PROTOCOL RATE FORMULA VALUE (HEX) IT1 600 16 MHz/(600 × 16 × 4) = 417 1AI IT2 4800 16 MHz/(4800 × 16 × 4) = 52 34 HART 1200 16 MHz/(1200 × 16 × 4) = 208 D0
Master Control Register (Address 6 )
This register controls various parameters.
Force PWM On Transmitter Idle (D 10 )
This bit is valid only when the signal encoding is PWM. Set this bit high to force a 50% duty cycle on the PWM serial output when the transmitter is idle. Set this bit low to passivate the transmitter serial output when the transmitter is idle. When this bit is set high, the resulting 50% duty cycle signal may be used by external circuits as a carrier to modulate the received dual tone, and pass the high frequency modulated signal through a galvanic isolation transformer.
Signal Encoding (D 9 -D 8 )
These two bits determine the signal encoding expected at the receiver serial input, and also the signal encoding provided at the transmitter serial output. The NRZ encoding bypasses the modem and PWM circuits, and the expected input is non-return to zero (NZR) frames flanked with start and stop bits. Selecting this mode is equivalent to using the DTASC as a simple UART. The Tone encoding bypasses the PWM circuit, and the data at the serial input and serial output is dual tone. The PWM enconding forces high frequency pulse-width-modulated data to be transmitted at the serial output, and expects to receive dual tone data at the serial input.
Transmit Enable (D 5 )
Setting this bit high forces the data stored in the transmit FIFO (or holding register when FIFOs are not enabled) to be transmitted out. Keeping this bit low allows data to be written to the transmit FIFO without starting transmission. This feature is not usually found in standard UARTs, which instead respond to FIFO writes by automatically initiating transmission. Use of this bit facilitates maximum FIFO utilization, so that the FIFO may first be filled, and the transmission may then be commenced by setting this bit high with a full FIFO. Clearing this bit somewhere in the middle of a frame during a transmission does not stop the transmission. Rather, the current frame transmission is carried out to completion, and only then the transmitter stops.
FIFO Enable (D 4 )
Write this bit high to enable the transmit and receive FIFOs. Write this bit low to disable the FIFOs. The transmit FIFO is eight bytes deep, the receive FIFO is sixteen bytes deep. When the FIFOS are disabled, the transmitter operates with a transmit holding buffer, and the receiver operates with a receiver buffer. FIFOs increase the data throughput, and ease the processor's service of the DTASC.
Reset Transmitter (D 3 )
Write this bit to reset the transmitter. The bit is “push-button”. Writing the bit high initiates the reset, and the bit is self-clearing.
Reset Receiver (D 2 )
Write this bit to reset the receiver. The bit is “push-button”. Writing the bit high initiates the reset, and the bit is self-clearing.
Transmitter FIFO reset (D 1 )
Write this bit high to reset the transmit FIFO. The bit is “push-button”. Writing the bit high initiates the FIFO reset, and the bit is self-clearing.
Receiver FIFO reset (D 0 )
Write this bit high to reset the receive FIFO. The bit is “push-button”. Writing the bit high initiates the FIFO reset, and the bit is self-clearing.
Structural and Functional Description
As shown in FIG. 5 , the DTASC is made of eight communication channels, each consisting of a transmitter and a receiver. The DTASC transmitter is made of a Universal Serial Transmitter, an FSK Modulator and a PWM circuit. The Universal Serial Transmitter converts parallel bytes into NRZ equivalent serial frames (LSB is transmitted first), with start, data, optional parity and stop bits. The Modulator converts the resulting NRZ serial bit frame into equivalent dual tone FSK. The PWM circuit has the width of its high frequency pulse modulated by the dual tone FSK. The actual transmitted signal may be chosen among any one of the Universal Serial Transmitter, the Modulator or the PWM circuit modules.
The DTASC receiver is made of an FSK Demodulator and a Universal Serial Receiver. The Demodulator takes in FSK dual tone signal and recovers the equivalent NRZ serial data bits (including start, parity and stop bits). The Universal Serial Receiver strips the start, parity and stop bits, and converts the NZR serial frame into parallel bytes of data. The incoming signal may be either FSK or NRZ, and it may be routed to the appropriate module. See FIG. 9 .
Local loopback is routed from the FSK Modulator output to the FSK Demodulator input. The local loopback may be used to test the integrity of all the block's internal modules, except for the PWM circuit.
The Universal Serial Transmitter and Universal Serial Receiver may be operated in full duplex mode. The FSM Modulator and Demodulator can be only used in half duplex mode.
Universal Serial Transmitter and Receiver (UART)
As shown in FIG. 10 , the UART consists of a transmitter and receiver (with their FIFOs), a baud generator, and a microprocessor interface. The transmit and receive FIFOs are both 8-bit wide. The transmitter FIFO is 8 levels deep, and the receiver FIFO is 16 levels deep.
Transmitter
Description
The transmitter is organized around a 13-bit parallel to serial shift register. The start and stop bits are loaded in parallel, besides the data bits (up to eight) and parity bit. Data is loaded from the transmit holding register, or from the FIFO if enabled. The bits are shifted out serially at a rate dictated by the number programmed into the divisor latch. The data LSB is shifted out right after the start bit. The shifting occurs under the control of a logic state machine that sequences through idle, load, shift, and stopbit states.
Using the Transmitter
The transmitter controls are in the LINE CONTROL REGISTER. This is where the makeup of the frame is determined, namely, the number of data and stop bits, whether there is parity and the type of parity. To start transmitting, data must be written first into the TRANSMIT BUFFER REGISTER The Transmit Enable bit in the MASTER CONTROL REGISTER must then be set high. The data written in the FIFO is then transferred to the transmitter holding register, or to the FIFO if enabled. Any data stored in the holding register (or the FIFO) is scheduled for transmission, and is transmitted out as soon as the transmitter becomes idle. The transmitter first sends out the start bit, immediately followed by the LSB. Once it starts sending data, the transmitter will continue transmitting frames as long as it finds data in the transmit FIFO, and as long as the Transmit Enable bit is high.
The transmitter may be serviced by polling. When polling, read the Transmitter FTFO Empty Bit in the LINE STATUS REGISTER. Enabling the FIFOs relieves the burden of servicing the UART, since up to sixteen characters may be stored in the FIFO by writing them all sequentially and without interruption into the TRANSMITTER BUFFER REGISTER.
Receiver
Description
The receiver is organized around a serial to parallel converter. After detecting a start bit, the frame bits are shifted serially into the converter, including up to the first stop bit. The stored frame is examined for possible parity errors, framing errors, and also for the possibility of being a break character. This error/status condition is stored together with the data into an 11-bit (three bits for error, plus eight data bits) receiver holding register, or into the 16-deep receiver FIFO if enabled. The errors affect the readout of the LINE STATUS REGISTER when the data gets to the read end of the FIFO.
Detection of the start bit is done with the help of a simple transition filter, in order to ignore any possible spurious low noise pulses in the receive line. Data is first clocked by the raw receiver clock into an eight-register transition filter. The transition filter declares a start bit only if four consecutive samples are low after four consecutive high samples. Once a start bit is detected, the rest of the frame is sampled at the estimated half point of each bit, based on the given baud rate. The raw receiver clock (obtained from the master clock input CLK after division by the divisor latch) is 16 times faster than the data (baud) rate.
FSK Modulator
The FSK modulator accepts as input a simple non-return to zero data bit stream and encodes it as a dual tone signal. The resulting dual tone is characterized by only two possible discrete periods, depending on the data to be encoded. The duration of the signal “peaks” and “valleys” is itself quantized to two possible discrete time constants, as illustrated in FIG. 11 .
On a first instance, the dual tone generation algorithm samples the bit to be encoded at the onset of a signal swing, and thereby determines the duration of the starting “peak” or “valley”. This would be sufficient if dual tone signal swings were aligned with bit boundaries. However, bit boundaries are not normally coincident with dual tone signal periods. Therefore, the original estimation of “peak” or “valley” signal duration must be reevaluated again at the bit boundary. This may or may not result in a duration update, as illustrated in FIG. 12 .
The complete dual tone generation algorithm implementation is illustrated in FIG. 13 . The circuit is centered around an 11-bit loadable down counter. Whenever the counter counts down to zero, the dual tone signal swings. The counter is preloaded with either a HIGH or LOW constant, depending on the encoding bit.
The choice of constant determines the short and long duration of the dual tone “peaks” and “valleys”. On a bit boundary, if a bit change occurs, the current value Q of the counter is conditionally adjusted by an amount equal to the difference of HIGH and LOW, resulting in a potential duration update. The modulator circuit clock frequency is different for each protocol, as depicted in the table below. The table also lists the values of the HIGH and LOW constants for each protocol, as well as the resulting mark and space tone frequencies.
FSK MODULATOR CIRCUIT PARAMETERS MAX TONE CLOCK MARK TONE SPACE TONE FREQUENCY FREQUENCY FREQUENCY FREQUENCY ERROR PROTOCOL (MHz) HIGH LOW (Hz) (Hz) (%) IT1 0.5 79 47 5,208.33 3,125.00 0.010 IT2 1.0 79 47 10,416.67 6,250.00 0.003 HART 4.0 908 1666 1,199.76 2,200.22 0.020
FSK Demodulator
The FSK demodulator accepts as input a digital dual tone signal and recovers the equivalent NRZ data bit stream. The user has a choice of two different algorithms to decode the dual tone, one is discrete digital continuous autocorrelation and the other one is integrate and dump. Both algorithms are described below.
Discrete Digital Continuous Autocorrelation
Discrete digital continuous autocorrelation compares the original dual tone signal with its own time-delayed version, using an XOR logic gate. The XOR gate output is either mostly high or mostly low, depending on the frequency of the input tone, and this signal is accumulated by virtue of controlling the up/down control of a 6-bit digital counter. The counter saturates when the count reaches a lower or an upper bound. The original ones and zeroes encoded in the FSK input may be decoded from the accumulated count, as it reaches its upper or lower saturation limits. A block diagram of the continuous autocorrelation method is provided in FIG. 14 . The NRZ decode logic is implemented with a JK flip flop, whose J input is set high if the counter saturates at one end, and whose K input is set high if the counter saturates at the other end. This method provides maximum hysteresis and noise immunity. Alternatively, the J and K inputs may be forced high if the counter reaches a given limit away from its neutral center count, but well before saturation ( 30 and 34 respectively in this design). This last method provides minimum hysteresis and faster response.
Each protocol has its own parameters of circuit sampling clock frequency, number of bit delays, and saturate bounds, as summarized in the table below.
CONTINUOUS AUTOCORRELATION PARAMETERS
SAMPLES
SAMPLING
PER FSK
CLOCK
UPPER
LOWER
PERIOD
FREQUENCY
DELAY
SATURATION
SATURATION
(high tone/
SAMPLES
PROTOCOL
(KHz)
(bits)
LIMIT
LIMIT
low tone)
PER BIT
IT1
125.0
22
57
7
24/40
208
IT2
250.0
23
41
22
24/40
52
HART
62.5
28
44
20
28/52
52
FIG. 15 illustrates the relation between the dual tone input tone, its 28-bit delayed signal dtone, their XOR comparison xor for HART, plus a bit boundary. The XOR signal is mostly low for a low frequency tone input, which drives the counter down towards an NRZ zero resolution. Conversely, the XOR signal is mostly high for a high frequency tone input, which drives the counter up towards an NRZ one resolution.
FIG. 16 illustrates the counter's permitted and out of bound ranges for HART, as well as the time value of the counter, as it swings towards its saturation high and low. The JK trigger points for minimum hysteresis are shown within the counter valid range.
Integrate And Dump
Referring to FIG. 17 , the integrate and dump method accumulates (integrate) a count until a transition is detected in the FSK dual tone input, at which point the counter is initialized to one (dump). If the count is plotted with respect to time, the resulting sawtooth waveform has maximum peaks which are smaller for high frequency tone, and greater for low frequency tone. The essence of the integrate and dump method is to compare these maximum peaks with respect to two discrete legal bands (defined by min, med and max constants). If the peaks are within these bands, the dual tone is legal, and the equivalent NRZ bit is simply decoded from the particular band where the peak lies. The counter saturates when it reaches the upper limit to avoid overruns.
The integrate and dump circuit is very effective for carrier detection. It can easily detect if the tone is outside the frequency bounds of the protocol. The validity of the tone may be read from the LSR register.
The integrate and dump circuit is also used to reset the continous autocorrelation receiver when no tone is present. Each protocol has its own parameters for circuit sampling clock frequency, as well as bounds for the decoding bands, as summarized in the table below.
INTEGRATE AND DUMP PARAMETERS
SAMPLING CLOCK
PROTOCOL
FREQUENCY (KHz)
MIN
MED
MAX
IT1
125.0
9
15
26
IT2
250.0
9
15
26
HART
62.5
11
20
33
FIG. 18 illustrates an example of an FSK dual tone signal suffering first from low frequency and then from high frequency loss of carrier. The resulting count waveform at the integrate and dump circuit is illustrated in FIG. 19 .
Half Duplex Arbitration
Any dual tone channel may be independently operated in full duplex as a standard serial port (NRZ mode), and it may therefore transmit and receive simultaneously. However, when operated in either tone or PWM mode, the channel is forced to half duplex, and it is only capable of either transmitting or receiving at any given time. In half duplex, the transmit mode is dominant, and the channel will transmit if the transmit FIFO contains any data and the transmit enable bit is set. The receiver is disabled from the time the transmission starts until the time the last piece of data available in the transmit FIFO has been fully transmitted. The hardware enforces fill termination of the last transmitted tone, so the line wiggles a whole period, and comes to a full rest before turning off. The receiver becomes enabled whenever the transmitter is idle.
PWM Circuit
The PWM circuit encodes the dual tone FSK into a 1 MHz pulse width modulated signal, and provides trapezoidal transition approximation for the encoded HART mode, but not for IT1 nor IT2.
FIG. 20 is a block diagram of the PWM circuit The input to the block is a single bit FSK signal, which goes into an FIR filter. The output of the FIR filter is a 3-bit binary-encoded and trapezoidally approximated dual tone signal, whose range is between 1 and 7. This trapezoidal signal goes into a conditional saturation block, which forces the signal to maximum and minimum values to eliminate trapezoidal approximation for IT1 and IT2. The resulting signal is extended to four bits and subtracted from a fixed value of 12 10 . The result is compared with a fast 4-bit counter, clearing the PWM output signal when equal, and setting it when zero. The resulting PWM waveform is shown in FIG. 21 for the minimum, median (50%) and maximum pulse widths, corresponding to an FIR output of 1, 4 and 7 respectively.
The FIR filter is a 7-tap FIR filter with unit coefficients, clocked at 1/76 the transmitter rate. The FSK data is first converted from 1-bit [0,1] to 2-bit two's complement sequence with range [−1,+1]. The filter equation is
y ( n ) ∑ k = 0 o x ( n - k )
The resulting sequence grows to 4-bit, with a range in [−7,+7]. The sequence is finally reduced to three bits in the range [1,7] as illustrated in FIG. 22 .
The trapezoidal waveform that emerges from the FIR filter is designed to fit within the minimum and maximum boundariy specifications for the HART signal, as illustrated in FIG. 23 .
System Loopback
Besides the internal loopback provided within each individual channel, the DTASC can be tested in a system loopback mode, in which each channel receives data transmitted by a near neighbor. The receiver input in each chanel is thus effectively disconnected from its external pin. The connection topology is illustrated in FIG. 24 . This loopback configuration is programmed in the GENERAL TEST REGISTER of the SYSTEM REGISTER block writing the Internal Dual Tone System Loopback bit high.
All eight TXON output signals from the DTASC are deasserted low during system loopback, turning off the external line driver. This allows online system loopback testing.
The Dual Tone Block and the Commcontrol Asic
The CommControl ASIC does not have dedicated package pins connecting to the dual tone block. Instead, the general purpose IO_SIG 31-0 pins must be appropriately programmed to route inputs and outputs to and from the block. Internal tone input RXSD 7-0 , tone output TXQ 7-0 and transmit enable TXON 7-0 signals in all eight dual tone channels may be routed to any external IO_SIG 31-0 pins.
More on Continuous Autocorrelation
The discrete digital continuous autocorrelation algorith described is an equivalent implementation of the following analog mathematical relation
f ( T ) = sat ( ∫ ( t = 0 ) T x ( t ) · x ( t - τ ) ⅆ t )
where x(t) is the dual tone input, τ is an appropriate delay parameter. In the analog case, x(t) is ±1, whereas in the discrete digital case, the FSK consists of ones and zeroes. Multiplication in the domain of ±1 is equivalent to the XOR logic operation in the domain of ones and zeroes.
Pin Multiplex controller
Introduction
The Pin Multiplexer Controller consists of 32 registers. Each register controls the function of one of the 32 I/O pins of the ASIC. It controls whether the pin is an input or an output and which internal function block is connected to the pin. A bit in the register can be set to invert the signal to or from the I/O pin. A block diagram of one pin controllers is shown in FIG. 25 .
In FIG. 25 , Din, Dout, Sclk refer to SPI functions. The first selection block controls which function is connected to the second mux. The second mux controls which channel's function is connected to the physical I/O Pin. In this diagram, Din, Sclk, Dout, DACs, ADCsel are driven by state machines, not by the processor. Pulse In is read by the pulse counter/period measurement section. Discrete input and Discrete output are read and written to respectively by the processor. The mapping of the I/O bit, inversion bit and I/O mux control bits for each pin to registers is shown in FIG. 26 . A memory map of these registers is shown in the table below:
PIN MULTIPLEXER REGISTERS
HEX
ADDR
ESS
NAME
RW
BIT
DESCRIPTION
236
IO Pin register 28
RW
(D)7-0
238
IO Pin register 29
RW
(D)7-0
23A
IO Pin register 30
RW
(D)7-0
23C
IO Pin register 31
RW
(D)7-0
23E
IO Pin register 32
RW
(D)7-0
Each physical IO_SIG 31 - 0 pin of the CommControl ASIC package can be routed to any one of several SPI channel functions, discrete input or output bit, or pulse input channel. In the case of the SPI channel, the pin may be routed to either the SPI clock, data in, or data out. Furthermore, in the case of the analog outputs with readback, the physical pin may be routed to any one of four ADC select lines or any one of four DAC select lines. In the case of the group isolated analog inputs, the physical pin may also be routed to ADCsel. This is illustrated in FIG. 27 .
Described above are methods and apparatus for communication across an isolation barrier meeting the objects set forth above, among others. It will be appreciated that the illustrated embodiment is merely an example of the invention and that other embodiments, incorporating changes therein, also fall within the scope of the invention. Thus, by way of example, it will be appreciated that inductive elements other than transformers may be used to carry the pulse width modulated and amplitude modulated signals between the control devices. By way of further example, it will be appreciated that the illustrated methods and apparatus can be used in control applications other than process control, e.g., industrial, environmental and other control applications. By way of still further example, it will be appreciated that PWM signals can be used to transfer information in both directions between the control devices. By way of still further example, it will be appreciated that the methods and apparatus discussed herein may be utilized for communications between any variety of control devices, not just controllers and field devices.
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Improved control apparatus and methods transfer information between devices, such as controllers and field devices, utilizing a modulator that generates a pulse width modulated (PWM) signal containing information to be transferred by a first of the devices, e.g., the controller, to the second device. A transformer or other inductive device transfers the PWM signal across the isolation barrier, where it is demodulated to analog form for application to the second device, e.g., the field device. Information transferred from the second device to the first device can be transferred in an amplitude modulated (AM) signal that utilizes, as its carrier, a fixed duty cycle output of the modulator that generates the PWM signal.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for making a colored multilayer composite by laminating to each other, and curing, two or more radiation-curable layers, one of these layers being a clear outer layer and the other layers being equipped with color pigments, and also to a colored multilayer composite of this type, produced by the method.
BACKGROUND OF THE INVENTION
[0002] WO 94/09983 has disclosed that colored vehicle parts can be produced with at least two different shades by transfer onto the vehicle parts of colored acrylic layers which have been applied to casting films. A laminate of this type is composed of a first polyester supporting layer, of a clear layer made from an optically clear polymer which comprises fluorinated hydrocarbon resin and acrylic resin, the clear layer having been applied on the surface of the supporting layer, and also of a binder layer and of a color layer made from chlorinated polymer with dispersed color pigments. Laminated onto the color layer is a second polyester supporting layer with an adhesive layer. This laminate takes the form of a multilayer composite and is applied to vehicle parts using techniques associated with pressure-sensitive self-adhesives, followed by removal of the first supporting layer abutting the clear layer, so that the clear layer forms a weather-resistant outer layer of the laminate. The PVC-containing color layer is flexible at room temperature and permits dimensional change within the laminate, which can therefore be laminated onto vehicle parts of three-dimensional shape. For durable and firm adhesive anchoring of the color layers, this laminate requires intermediate layers made from specific adhesives which have to fulfill certain preconditions.
[0003] EP 0535504 B1 discloses a process for image transfer to coated surfaces, in particular those of timber-based materials, the surface being coated with a polymeric layer made from low-molecular-weight polymers and requiring curing by irradiation with electrons. The polymeric layer is brought into contact with a transfer medium bearing color pigment, with exposure to heat. There is diffusion of the color pigments into the polymeric layer. The irradiation with electrons cures the polymeric layer, crosslinking being undertaken with a radiation dose of from 40 to 80 kGray.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide a method which produces an at least two-coloured multilayer composite, can be carried out cost-effectively on an industrial scale and which moreover manufactures the multilayer composite without adhesive layers and produces a multilayer composite whose decorative properties are durably resistant to the effects of weathering.
[0005] According to the invention, the manner of achieving this object comprises, in a first step, partially curing the radiation-curable layers applied to supporting layers, and in a second step, completely curing the radiation-curable layers.
[0006] The features of the method of the invention are that in the first step, the first radiation-curable layer, equipped with color pigments, is applied to a first supporting layer, that the second radiation-curable layer, equipped with color pigments, is applied to a second supporting layer, where the color pigments of the first layer differ from those of the second layer, that the two supporting layers are laminated, with the radiation-curable layers facing toward one another, to give a multilayer composite, and the radiation-curable layers are partially cured, and that in the second step, the multilayer composite is laminated with a plastic film to which a radiation-curable clear outer layer is applied, which faces toward the multilayer composite, and that the mutually abutting layers are completely cured.
[0007] In executing the method, the partial curing and the complete curing of the layers is undertaken with the aid of actinic radiation. The actinic radiation used here comprises accelerated electrons, UV radiation in the wavelength region from 50 to 480 nm or X-ray radiation in the wavelength region from 0.05 to 8.0 nm.
[0008] In another embodiment of the method, use is made of radiation-curable layers based on C1l-C6-alkyl acrylates and/or methacrylates, in particular those based on methyl acrylates or on ethyl acrylates and/or methacrylates.
[0009] In one embodiment of the method, the dose of actinic radiation in the steps is adjusted so that the amount of radiation required for the complete curing of the radiation-curable layers is not applied until the final irradiation stage.
[0010] If the amount of radiation theoretically needed for complete curing has been reached prior to the final irradiation stage, the bond strength of the clear outer layer can be adversely affected.
[0011] Further embodiments of the method arise from the measures described in claims 7 to 15 .
[0012] The invention uses the method to produce a two- or multicolored multilayer composite which is composed of a supporting layer with a smooth regular surface, which is a plastic film or is a phenolic-resin-impregnated paper web, and of two or three acrylic-based layers laminated to one another and radiation-cured and comprising different color pigments, and of an acrylic-based clear outer layer, and also of a peelable plastic film as protective layer.
[0013] A multilayer composite of this type may be a decorative coating bonded to plates or panels made from layers of paper saturated with phenolic resins and/or with melamine resins, or made from cardboard packaging, from wood, from plastics, from resin-saturated compacted wood chips or the like, to give weather-resistant panels for outdoor use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 shows a process diagram for the production of a single-coloured multilayer composite from a paper support, a curable color layer, a clear outer layer and a plastic film as in the prior art,
[0015] [0015]FIG. 2 a shows a diagram of the first step in the production of an at least two-coloured multilayer composite according to the invention,
[0016] [0016]FIG. 2 b shows a diagram of the second step in the production of an at least two-coloured multilayer composite,
[0017] [0017]FIG. 2 c shows a diagram of a second step modified from FIG. 2 b for the production of a three-coloured multilayer composite according to the invention,
[0018] [0018]FIG. 3 a shows a diagram of a first step modified from FIG. 2 a for the production of a metallic-effect multilayer composite according to the invention, and
[0019] [0019]FIG. 3 b shows a diagram of a second step modified from FIG. 2 b for the production of a metallic-effect multilayer composite.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In FIG. 1, a phenolic-resin-saturated or phenolic-resin-impregnated paper substrate 31 has been wound up on a feed roll 20 . The web of paper substrate 31 is unwound from the feed roll 20 and passes through a printing unit 21 where screen printing or stencil printing is used to apply a color layer 151 . This color layer 151 is an acrylic layer which comprises color pigments.
[0021] Furthermore, a plastics film 71 which has been wound onto a plastics film feed roll 51 is unwound and passed through another printing unit 61 . In this printing unit 61 , screen printing or stencil printing is used to apply a colorless protective layer to the plastic film 71 , examples of which are a polyolefin, such as polyethylene or polypropylene, a polyester or the like. The colorless protective layer 171 is also acrylic-based. The paper substrate 31 with the color layer 151 and the plastics film 71 with the colorless protective layer 171 are brought together in a laminating unit 41 and laminated to each other with the aid of heat and/or pressure, to give a multilayer composite 91 . After leaving the laminating unit 41 , the multilayer composite 91 passes through a curing unit 81 , in which accelerated electrons are used for complete curing of the two mutually abutting layers, namely the color layer 151 and the protective layer 171 , thus forming a solid composite. The multilayer composite 91 is a single-coloured laminate with an optically clear outer layer or protective layer 171 , and is wound up onto a multilayer composite feed roll 101 .
[0022] This known process does not permit production of a two- or multicolored multilayer composite comprising curable layers without the use of adhesive layers, since complete curing of the layers takes place immediately after lamination of the layers to give the multilayer composite. This means that bonding between further layers is not possible without resorting to the use of adhesive layers.
[0023] The curing of the layers may be undertaken with actinic radiation quite generally, but specifically for the purposes of this invention the radiation is preferably highly accelerated electrons, as preferably used in the curing unit 81 , and UV radiation in the wavelength region from 50 to 480 nm or X-ray radiation in the wavelength region from 0.05 to 8.0 nm.
[0024] For the curing by irradiation with accelerated electrons, a maximum dose of up to 60 kGray is generally sufficient. After curing with a dose of this type, the majority of the reactive acrylic groups have reacted, and the cured layers are completely dry and solid. If the curable layers are irradiated with a dose lower than that given above the curing achieved is only partial, meaning that there are still sufficient residual reactive acrylic groups which can react with another acrylic layer. This is the inventive concept on which the method of the invention is based, as is described in more detail with reference to FIGS. 2 a to 3 b.
[0025] In a first step, as shown in FIG. 2 a, a first supporting layer 3 , for example a film web or a phenolic-resin-saturated paper web, is equipped with a first radiation-curable layer 15 . This first curable layer is an acrylic-based layer and comprises color pigments of a particular color. The supporting layer 3 has been wound up on a first feed roll 1 and, after unwinding, is passed through a first printing unit 2 , in which screen printing or stencil printing is used to apply the first curable layer 15 . A second supporting layer 7 , for example a plastics film, has been wound up as a web on a second feed roll 5 . This second supporting layer 7 is unwound from the second feed roll 5 and passes through a second printing unit 6 , in which screen printing or stencil printing is used to apply a second radiation-curable layer 16 which comprises color pigments of a particular color. These color pigments differ from the color pigments in the first curable layer 15 . The two supporting layers 3 and 7 are brought together with the layers 15 , 16 facing toward one another immediately prior to a first laminating unit 4 , in which they are pressed together with exposure to heat and/or pressure to give a multilayer composite 9 , a section of which is shown in detail at A. After leaving the laminating unit 4 , the multilayer composite 9 passes through a first curing unit 8 , in which accelerated electrons partially cure the two layers 15 , 16 . The electron radiation dose is in the range from 0.5 to 30 kGray and is insufficient for complete curing of the two layers. The curing may also be carried out using UV radiation in the wavelength region from 50 to 480 nm or X-ray radiation in the wavelength region from 0.05 to 8.0 nm, instead of accelerated electrons. The partial curing of the layers 15 , 16 takes place in the first step using not more than 30% of the maximum radiation dose required for complete curing of the layers. This gives a two-coloured multilayer composite 9 , which is wound up onto a multilayer composite feed roll 10 . There then follows the second step, as shown in FIG. 2 b, in which the two-coloured multilayer composite 9 passes through the existing system for a second time. To this end, the multilayer composite feed roll 10 replaces the first feed roll 1 in the first step, and the multilayer composite 9 is unwound from the feed roll 10 . Prior to the second step it is useful for the second supporting layer 7 to be removed from the multilayer composite 9 . A section of the multilayer composite 9 , without the supporting layer 7 which has been removed, is shown in detail at B. The composite 9 passes through the first printing unit 2 which has been taken out of operation in the present instance, since there is no further color layer to be applied.
[0026] A web-shaped plastics film 12 is unwound from a third feed roll 11 , and passes through the second printing unit 6 , in which screen printing or stencil printing is used to apply an optically clear layer, namely what is known as the clear outer layer 17 . Although no color pigments are present in this layer, it is similar to the layers 15 and 16 in being an acrylic layer curable by actinic radiation. The multilayer composite 9 and the plastics film 12 which acts as a protective film, with the clear outer layer 17 which has been applied, are brought together prior to or in the laminating unit 4 , and laminated to each other in this laminating unit by means of heat and/or pressure. After leaving the laminating unit 4 , the laminate made from two-colored multilayer composite 9 and from the clear outer layer 17 together with the plastics film 12 passes through the curing unit 8 , which in the second step uses the accelerated electrons at full power, i.e. a dose of from 1.65 to 100 kGray, to bond the clear outer layer 17 with the two layers 15 and 16 which have previously been partially cured. The full radiative power of the curing unit 8 completely cures the curable layers 15 , 16 , 17 , and these form a dry and firmly bonded ply within the two-colored multilayer composite 13 . This multilayer composite 13 is wound up onto a multilayer composite feed roll 14 . A section of the multilayer composite 13 is shown in detail and at C on an enlarged scale.
[0027] It is also possible to apply a still further color layer in the second step, thus obtaining a three-colored multilayer composite. The only requirement for this is that, in what is known as the modified second step shown in FIG. 2 c, during passage of the two-colored multilayer composite 9 through the first printing unit 2 screen printing or stencil printing is used to apply a radiation-curable layer 18 which has been equipped with color pigments. A section of the multilayer composite with the curable layers 15 , 16 and 18 , and also with the first supporting layer 3 , is shown in detail at D. In other respects the procedure is unchanged from the second step as shown in FIG. 2 b. A section of the resultant multilayer composite 19 made from a first supporting layer 3 , the curable layers 15 , 16 and 18 with color pigments, the clear outer layer 17 and the protective film 12 is shown in detail at E.
[0028] Examples of the curable layers 15 , 16 , 17 and 18 used are those based on C1-C6-alkyl acrylates and/or methacrylates, in particular based on methyl acrylates or on ethyl acrylates and/or methacrylates. Alongside these, use may also be made of comonomer units, in particular acrylonitrile or alkyl vinyl ethers.
[0029] A very general rule for the method is that the dose of actinic radiation which is applied in the curing unit 8 has been adjusted so that the amount of radiation required for complete curing of the curable layers is not applied until the final irradiation stage. In the first step, therefore, the curable layers 15 , 16 are brought into contact with not more than 30% of the maximum dose of actinic radiation required for full curing. In the second step, the two partially cured layers 15 , 16 and the clear outer layer 17 are brought into contact with a dose of from 30% to 100% of the actinic radiation for full curing. This again applies to the case where another curable layer 18 with color pigments is additionally applied to the multilayer composite 9 in the modified second step. The color of these color pigments differs from that of the color pigments of the curable layers 15 and 16 . It is preferable for the color pigments of the layers 15 , 16 and 18 to be selected from the group consisting of metal oxides, metal hydroxides and metal oxide hydrates, sulfur-containing silicates, metal sulfides, metal selenides, complex metal cyanides, metal sulfates, metal chromates, metal molybdates, azo pigments, indigoids, dioxazine pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, perylene pigments, perinone pigments, metal complex pigments, alkali blue pigments and diketopyrrolopyrrole (DPP) pigments.
[0030] In another embodiment of the method, the curable layers 15 to 18 may be applied to the associated supporting layers by casting or by printing rollers, instead of by screen printing or stencil printing.
[0031] The plastics of the web-shaped plastics films are particularly selected from the group consisting of polyolefins, such as polyethylene and polypropylene, and polyesters, or from the group consisting of polyamides.
[0032] The two- or multicolored multilayer composite 13 obtained by the method is therefore composed of a supporting layer, which is a film or a phenolic-resin-impregnated paper web 3 , of two or three acrylic-based, cured layers 15 , 16 , 18 laminated to one another and each comprising a different color pigment, of an acrylic-based clear outer layer 17 , and also of a peelable plastics film 12 as protective layer. This multilayer composite 13 is preferably used as a decorative coating bonded to sheets made from layers of paper saturated with phenolic resins and/or with melamine resins, or made from cardboard packaging, from wood, from plastic, from resin-saturated compacted wood chips or the like. Applying this multilayer composite 13 to sheets of this type gives weather-resistant panels or decorative plates for outdoor use on buildings, for example as cladding, or in indoor areas subject to moisture.
[0033] In the modified first step as described in FIG. 3 a, a third web of supporting layer 24 has been wound up on a fourth feed roll 22 . An example of the supporting layer 24 is a plastics film, preferably a polypropylene film with a very uniform, smooth surface. The supporting layer 24 is drawn off from the feed roll 22 , and a metallic coating 23 is applied to the supporting layer 24 . The metallic coating 23 is composed of an acrylate-based layer in which color pigments have been dispersed. The color pigments are preferably metal oxide pigments, in particular aluminum oxide pigments which give the metallic coating 23 a metallic color.
[0034] A fourth supporting layer 25 has been wound up on a sixth feed roll 36 , and after this layer has been unwound from the feed roll 36 it receives an application of a radiation-curable clear layer 26 . The supporting layer 25 is again a plastics film with a smooth uniform surface. With the metallic coating 23 and clear layer 26 facing toward one another, the two supporting layers 24 , 25 are brought together in a second laminating unit 27 , where they are laminated by means of pressure and/or heat, to give a multilayer composite 28 , which immediately after emerging from the laminating unit 27 passes through a second curing unit 29 . In this curing unit 29 , the clear layer 26 and the metallic coating 23 are partially cured by an electron beam with a dose of from 2 to 30 kGray, followed by winding-up onto a multilayer composite feed roll 30 . A section of the multilayer composite 28 is shown in detail at F.
[0035] In the modified second step shown in FIG. 3 b, the multilayer composite feed roll 30 is on the right-hand side, and when the multilayer composite 28 is unwound from the feed roll 30 the supporting layer 24 is simultaneously removed from the metallic coating 23 . A section of the multilayer composite 28 , without the supporting layer 24 , is shown in detail at G.
[0036] On the left-hand side of FIG. 3 b a fifth supporting layer 33 wound up on a fifth feed roll 32 has a highly non-uniform surface, on which, after unwinding from the feed roll 32 , a primer layer and/or adhesion-promoter layer 34 made from a radiation-curable primer and/or from a radiation-curable adhesion promoter is applied. A section through the supporting layer 33 and the primer layer and/or adhesion-promoter layer 34 is shown in detail at H. An example of the supporting layer 33 is a phenolic-resin-impregnated paper web, or what is known as a kraft paper.
[0037] The multilayer composite 28 , without the supporting layer 24 , and the supporting layer 33 with the primer layer and/or adhesion-promoter layer 34 applied are brought together in the second laminating unit 27 , where they are pressed together using heat and/or pressure, to give a multilayer composite 35 . The multilayer composite 35 then passes through the second curing unit 29 , in which accelerated electrons are used for complete curing of the layers 23 , 26 and 34 in the multilayer composite 35 , using a dose of from 6.7 to 100 kGray from the electron beam. A section of the structure of the multilayer composite 35 is shown in detail at I. The multilayer composite 35 is wound up onto a multilayer composite feed roll 37 and used for further processing as a decorative coating for plates or panels.
[0038] The curing unit 29 may also be a UV or X-ray unit, in which case the curing of the layers takes place with the aid of UV radiation in the wavelength region from 50 to 480 nm or X-ray radiation in the wavelength region from 0.05 to 8 nm.
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The method for making a multilayer composite having one or more colors brings together a number of acrylic layers, which are partially cured in a first step and completely cured in a second step. The curing takes place with actinic radiation, such as accelerated electrons, UV radiation or X-ray radiation, the curing unit operating with different dosage rates during the two steps. The curable acrylic layers are applied to the respective supporting layers by screen printing or stencil printing, or else may be applied to the supporting layers by casting or with the aid of printing rollers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to exercise devices. More particularly, this invention pertains to exercise equipment contemplated for cooperative use by two people.
2. Description of the Prior Art
In the past, exercise equipment was generally designed for use by a single individual or occasionally requiring use by a spotter. Many types of equipment were difficult or time consuming to set up for use by a single individual. A certain degree of human motivation is necessary to encourage regular exercise and that which has a tendency to reduce human inertia is likely to increase regular usage of the equipment. Thus, it would be desirable to have exercise equipment that would increase motivation to help develop and maintain human physical fitness.
SUMMARY OF THE INVENTION
An exercising device generally includes upper and lower supports for supporting a pulley arrangement. The pulley arrangement receives and supports the weight of a partner and transmits a force related to the partner's weight to an exercising means, such as a bar, which is grasped and pulled by the exercising individual. Means are provided for adjusting the partner related force by the partner. Thus the partner maintains control over the resistive force supplied to the exercising individual thus cooperatively participating in the exercising activity.
In a more specific example, the upper and lower supports are configured in a collapsable frame. An upper pulley group supports a harness or swing which supports the weight of the partner. A friction block, coupled to a line supporting the partner is adjustable to variably increase the force transmitted through the pulley arrangement. A lower pulley group, having multiple pulley passes, provides an advantage for reducing by a multiple the resistive force transmitted to the exercising device required to complete the exercising task. In addition, the lower pulley group comprises a pair of spaced apart pulley groups disposed in parallel for allowing exercising from either side of the exercising device, either simultaneously or independently.
Additional features in accordance with this invention include a third pulley group including a line couplable to the line extending to the exercising bar, and then extending downward from the upper support, to allow pull down exercises. The friction block includes a force sensitive transducer coupled to a display for providing an indication related to the force supplied by the exercising partner to the exercising individual. A futon extendable in a variety of different positions allows the exercising individual to engage in different types of exercises from various positions. Cables are disposed in a triangular relationship to the collapsable frame to keep the frame in a rigid relationship when in use, yet allow for the collapsing. Sliders, nominally fixed, are movable along upright portions of the frame to allow the device to be collapsed and folded when not in use.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature of the invention described herein may be best understood and appreciated by the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of an exercising device in accordance with this invention;
FIG. 2 is an elevational view of a portion of the invention depicted in FIG. 1;
FIG. 3 is an elevational view of a portion of the invention depicted in FIG. 1 taken along lines 3--3 of FIG. 2;
FIG. 4 is an elevational view of a portion of the invention depicted in FIG. 2 in which the device is coupled for pull down exercises in accordance with the invention;
FIG. 5 is a detail perspective view of a track and rail arrangement depicted in FIG. 1 in accordance with the invention;
FIG. 6 is a diagrammatic perspective view of a portion of the invention depicted in FIG. 1;
FIG. 7 is a diagrammatic perspective view of the portion of the invention as depicted in FIG. 6 showing how the device may be collapsed;
FIG. 8 is a diagrammatic perspective view of the portion of the invention as depicted in FIG. 6 further showing how the device may be collapsed;
FIG. 9 is a diagrammatic perspective view of the portion of the invention as depicted in FIG. 6 in a collapsed configuration;
FIG. 10 is a detail cross-sectional view of a friction block in accordance with the invention taken along lines 10--10 of FIG. 1; and
FIG. 11 is a detail perspective view of a portion of the invention depicted in FIG. 1.
DETAILED DESCRIPTION
With particular reference to FIGS. 1, 2 and 3, an example of an exercising device in accordance with this invention generally comprises a frame 10 having an upper support or track 12, a floor or lower support means or lower track arrangement 14 having a pair of spaced apart lower tracks 16 and a pulley arrangement 18 coupled to the upper and lower tracks 12, 16. The upper track 12 has an "H" beam cross section, as best viewed in FIG. 5, which defines a pair of lateral outwardly extending longitudinal flanges 20 disposed longitudinally along the track upper track 12.
The frame further comprises first and second spaced apart upright risers 22, 24 for coupling the lower track arrangement to the upper track 12 and supporting the upper track 12. Crossbars 26 are disposed normal to and centrally about a nominal plane of the frame 10. A structural cable arrangement 28 is used to provide rigidity to the frame and is coupled to the crossbars 26. One upper crossbar 26 is joined at the top of riser 22 adjacent the upper track 12. Another upper crossbar 26 is joined to the upper track 12, A hinge 25 joins the riser 24 to the upper track 12.
An outwardly extending member 30 disposed centrally along the lower tracks 16 extends normally outward from each of the lower tracks 16. The outwardly extending members 30 space the cable arrangement 28 sufficiently apart to avoid interfering with the exercising activity of the individuals using the apparatus. Typically, the outwardly extending members 30 space the cable arrangement 28 approximately 3 feet (1 meter) apart.
The exercising device has a front end 32 adjacent the partners region and a back end 34 adjacent the exercising region. The lower track arrangement 14 further comprises a front bar 36, supported by a pair of spaced apart short upright elements 38 are disposed adjacent the front end 32 of the exercising device. A horizontal bar 40 joined beneath the upright elements 38 supports the upright elements 38. The horizontal bar 40 is disposed normal to and joined to the lower tracks 16. The upright elements are coupled to hinged sliders 54 movable along the lower tracks 16, and thus enables the frame 10 to be collapsed as shown in FIGS. 7 and 8. The tracks 16 have plural segmented portions 43 and have hinges 45 for folding.
The structural cabling arrangement 28 generally contributes to maintain upright and stabilizes the risers 22, 24. The cabling arrangement 28 comprises twisted steel cable having a coating, such as polyurethane for ease of handling. The cabling arrangement 28 comprises a pair of end cables 42 arranged in an inverted "V" formation tranverse to a nominal plane of the frame 10 and are coupled from the opposing spaced apart ends 44 of a lower cross bar 15 to an upper end 46 of the vertical riser 22 at the rear end of the frame 10. At the front end 32 of the frame 10, a pair of end cables 48 arranged in an inverted "V" formation transverse to a nominal plane of the frame 10 are coupled from the opposing spaced apart ends 44 of the bar 36 to the upper end of the vertical riser 24 at the front end of the frame 10.
A second cabling arrangement 50 comprises a pair of cables arranged in a spaced apart and parallel "V" formation each of which are disposed in a plane nominally parallel to the plane of the frame 10. The cabling arrangement 50 comprises two sets of cables 52, on each side of the plane defined by the risers 22, 24, each separate cable 52 extending from one end of the upper cross bars 26, to the outermost ends of the protruding members 30. The second cabling arrangement 50 along with the upper crossbars 26 generally rigidly maintains the outwardly extending square relationship of the frame 10.
The tracks 12, 16 and the risers 22, 24 preferably have an H-beam cross-section as depicted in FIG. 5. In addition to providing strength to the frame 10, the H-beam cross sections define outwardly extending longitudinal flanges 20 which generally extend the length of the tracks 12, 16 and the risers 22, 24. Sliders 54 comprises front plates 55 and inwardly directed longitudinal flanges 56 extending from and folded inward from the front plates 55. The longitudinal flanges 56 engage in movable relationship the outwardly extending longitudinal flanges 20 of the H-beams. Means such as thumbscrews 53 extending through apertures in the risers, generally normal to the plane of the longitidal flanges 20, are provided for nominally fixing the positioning of the sliders 54 with respect to the tracks 12, 16 and the risers 22, 24. Bearings 58 may be used facilitate the movement of the sliders 54 along the risers 22, 24 and the tracks 12, 16.
A hinge 57 couples a slider 54 disposed on the riser 22 to the upper track 12. A thumbscrew 53 coupled to the slider 54 fixes the upper track 12 in a position normal to the riser 22, thereby maintaining the frame 10 in a square configuration. The slider 54, being movable along the riser 22, however, allows the frame to be folded, as indicated in FIGS. 6, 7, 8 and 9.
The pulley arrangement 18 comprises an upper pulley group comprising a partner supporting pulley block 60 and an offset fiddle block 62 having upper and lower pulleys 59, 61 disposed adjacent the front end 32. The fiddle block 62 is affixed to one of the sliders 54 and thus is adjustably movable along the upper track 12. The partner supporting pulley block 60 is disposed directly above a harness 63 for receiving the partner, and is coupled to the friction block 64 for enhancing the effective resistive force exerted by the weight of the partner. An upper line 66, extending from the friction block 64 passes through the pulley 60 and then through the pulley 59 of the offset fiddle pulley block 62 where the force is downwardly transmitted through a coupling 68. The upper line 66 then extends upwardly from the coupling 68 through the lower pulley 61 of the fiddle pulley block 62, and out through a cam clete 82. Once the line 66 is fixed by the cam clete 82, the effective length of the upper line 66 is no longer adjustable. Thus, a movement of the upper line 66 causes a corresponding movement of the lower line 102, though reduced by a multiple as a result of the multiple pulleys 76 extending from the coupling 68.
Similarly, a slider 54 coupled to the upper track 12 has a pulley block 67 nominally disposed above the region of an exercising individual and another pulley block 67 spaced apart from the first pulley block 67 and adjacent the riser 22 at the back end 34 of the frame 10. The pulley blocks 67 are staggered to prevent intereference with exercising. A line 69 extends through both the pulley blocks 67, the line 69 extending downwardly from the innermost pulley block 67 being couplable to exercise means such as a bar 71 or exercise handles 73, here used generally for pull down exercises such as lateral pull down or tricep pushdown exercises. The line 69 also has a U-bar 111 supporting shackles 112 for receiving clips 114 coupled to the lower line 102. Adjacent the pulley block 67 closest to the riser 22 is disposed an additional slider 54 having longitudinal flanges 56 engaging and movable along the riser 22, yet remains fixed by the tightening of the thumbscrew 53. A hinged portion 72 coupled to this slider 54 is coupled to the upper track 12 for generally maintaining the track 12 normal to the riser 22, yet allows folding and collapsing of the frame when the thumbscrew 53 is loosened, as shown in FIGS. 6, 7, 8 and 9. The coupling 68 is joined to a slider 54 coupled to the flanges 20 of the upright riser 24, thus, movable along a vertical axis. The coupling 68 has a pulley 74 for receiving the line 66. Beneath the pulley 74, the coupling 68 has bar 75 which suppports two groups of pulleys 76 in parallel spaced apart relationship about an axis normal to the plane of the frame 10 on opposing sides of the coupling 68. The two groups of pulleys 76 divide the effect of the resistive force transmitted by the exercising partner.
The harness 63 for supporting a second person or partner is disposed beneath and coupled to the friction block 64. The friction block 64 is a coupled to the upper line 66 which comprises 5/8" dacron cord and is theaded through the friction block 64 and under the partner supporting pulley 60. Dacron is preferably as it resists stretching, is stong and durable. The friction block 64 allows a resistive force to be adjusted and which is ultimately transmitted to an exercise bar 71 or handlebars 73, The friction block 64 has a dial 80 for force adjustment. The upper line 66 provides variable length adjustment for force up exercises. The upper line 66 extends from the friction block 64 which supports the harness 63 and couples the partner to the movement of the exercising individual using the system. The line 66 is further threaded through a cam clete 82 for adjusting the length of the upper and lower lines 66. A cam clete 82 extends from the partner to the exercise bar 7I or handlebars 73 to allow variations in position for different exercises and for the comfort of the individual doing the exercising and the partner.
The cam clete 82, best depicted in FIG. 11 (prior art) has an arm 84 extending to the offset pulley block 62. On the end of the arm are a pair of spaced apart spurs 86 movable about spaced apart parallel axes, and a bridge retainer element 88 joining the spurs 86 for retaining the upper line 66 when released from the spurs 86. The spurs 86 allow the release of the upper line 66 as the upper line 66 is loosely released into the region of the bridge retainer element 88, while grasping the upper line 66 when rapidly released. The pulley block 62 is positioned so that the upper line runs through the wheel of the pulley block 62 and through the spurs 86. When the pulley is released between the spurs 86, they are gripped by the spurs 86 and prevent further travel of the upper line 66. As an alternative to the cam clete 82, the pulley 74 may be replaced by a shackle to which the line 66 is affixed.
It should be appreciated that the exercising device in accordance with this invention is therefore adjustable, both in force exerted or resisted, depending on the exercising setup, and is further adjustable in height or length of the upper line 66, both to the individuals using the equipment and for the particular type of exercise to be performed.
A futon 90 comprises three dense foam sections 92, each having a fabric covering 94 and each hinged to each other by a fabric hinge 96. The futon 90 allows exercising to occur either in a sitting, standing or lying position, and further allows the exercising apparatus to be conveniently folded up after exercising is over, to become an attractive and functional piece of furniture. The foam sections 92 preferably have a high density, similar that of commonly used exercising mats.
The lower tracks 16 have parallel pulley blocks 100, as best viewed in FIGS. 1 and 3. A lower line arrangement comprising a pair of spaced apart lower lines 102, each lower line 102 extending from beckets 104 disposed in the central region of the coupling 68 and then extend over and about the pulley groups 76 to obtain a mechanical advantage from the multiple pulleys of each group 76. The lower lines 102 extend over the outermost pulleys of the pulley groups 76 and under an adjacent pulley 106 disposed on the front bar 36. Outermost pulleys 108 are disposed on the front bar 36 adjacent the short upright elements 38. The lower lines 102 extend downward over the pulleys 108 and under and through the pulley blocks 100 where they travel to pulley blocks 110.
It should be recognized that the pulley blocks 100 and 110 are coupled to sliders 54, thereby allowing the position of the blocks 100, 110 to be adjusted as needed.
The lower lines 102 transmit the length adjustment by the partner from the upper line 66 and further, in this particular example, provide an eight to one advantage in the effective transmitted force, for force up and force down exercises, simultaneously. A coupling arrangement 68 interconnects the short line 102 with the upper line 66.
The lower lines 102 are extended about and through the pulleys 110, and then to the handlebars 73 or to the exercise bar 71. It should be recognized that the handlebars 73 may be interchanged with the exercise bar 71, depending on the type of exercising activity to be conducted. Thus, the exercise bar may be joined above the pulleys 110 to the lines 102.
The exercise bar 71 is preferably covered with 1 cm. molded high density foam 77 for comfort. The exercise bar 71 comprises a transverse portion 79, a pair of angled end portions 81 having first and second apertures or loops 83 on each angled end portion 81 for attachment to the lower lines 102.
With particular reference to FIGS. 1, 2 and 10, the frictional block 64 generally comprises front and back plates 120, 122 to retain the block 64. Top and bottom spreaders 124, 126 maintain the front and back plates 120, 122 in parallel spaced apart relationship. A square aperture 128 passing through the front plate 120 and a square aperture 130 passing through the back plate 132 receives a threaded center post 134. The center post 134 couples the block 64 and allows tightening of the friction dial 80. Disposed about the center post 134 are sheave adaptors 133 having an inner cross sectional aperture 135 mating with that of the post 134 and an outer circular surface 137. Disposed on the outer circular surfaces 137 of the sheave adaptors 133 are roller bearings 139.
A pair of spaced apart serrated sheaves 136 having rough concave annular surfaces 138, disposed normal to the post 134 betweeen the front and back plates 120, 122 allow rope to spin through the block 38 without slipping. The roller bearings 139 allow the sheaves 136 to rotate freely about the post 134. Friction disks 141 of material such as leather impregnated with graphite, are disposed on opposite sides of each of the sheaves 136 for engaging the sheaves 136 and exerting resistive forces tending to prevent the sheaves from rotating. Circular clutch plates 142 are disposed between the back plate 122 and one of the sheaves 136. The clutch plates 142 allows smooth spinning of the sheaves 136, when not tightly compressed against the friction disks 141, yet provide a smooth uniform pressure when force is applied. The frictional force applied from the friction disks 141 to the sheaves 136 thereby exerts a resistive force on the line 66. Adjacent and parallel to and engaging the back plate 122, a compression spring 149 allows smooth application of force, distributing a force gradient within the friction block 64.
A transducer 150 is disposed between the friction plate 142 and the dial 180. The pressure transducer 150 has an inductance which is altered by the force exerted on it and bears a relationship to the frictional resistive force which is exerted by the second partner in the harness 63. This force exerted is the gravitational force of the partner, which is then enhanced by the frictional resistance of the frictional block 64. It is a force related to this enhanced force that is applied to the transducer 150. The transducer 150 is coupled to an analog to digital converter, the resulting signal is processed by providing a digital indication relating to the resistive force of the block exerted on the upper line 66. A digital signal relating to the resistive force, responsive to the transducer is then available and applied to a digital readout, such as a liquid crystal display 156.
The harness 63 comprises a webbing as in a swing. The harness 63, however, could be of a form that would fully surround the partner. A support bar 158 is suspended from the friction block 64. The support bar 158 has opposing ends having lines 160 extending to ends of the webbing.
In some situations, it may be preferable to have the upper track 12 joined directly to the ceiling of a home. A rigid coupling to a ceiling beam, then can eliminate the need for the structure of the risers 22, 24 and the cabling arrangements 28, 50. It is preferably then to have the track 12 have on the outwardly extending flanges 20, apertures for receiving lag screws and joining the track to a ceiling beam or stud.
In use, either the handlebars 73 or the exercise bar 71 is affixed to the lower lines 102 above the pulleys 110. The individual doing the exercises can then engage the exercise bar 71, for example. Depending on the particular exercise, the individual will either be in a sitting, standing or lying position and the futon 90 will be positioned accordingly. The exercising partner or spotter will engage the harness 63 and adjust the dial 80 of the frictional pulley block 38 for an appropriate weight will be shown on the display 82 of the friction block 64.
The length of the upper line 66, which controls the starting postion of the exercise bar 71 is determined in part by the position of the line 66 extending through the cam clete 82, which is adjusted by the individual in the harness 63 by pulling on the cam clete 82 and allowing the proper amount of rope to be taken up or let out, and then by having the cam spurs 84 of the cam clete engage the line 66. At this point, exercises may begin.
The individual doing the exercises, for example, in doing curls, pulls up on a weight which is reflected on the dial 80 of the friction block 64. The weight of the second individual thus controls the upward force exerted by the person engaging in the exercising activity. Should the individual then stand up or be released from the harness, the added weight of the exercuse bar 71 is essentially eliminated, except for the actual weight of the exercise bar 71 and certain other minor weight factors.
The futon 90 can then be moved to a chair or extended position for exercising different sets of muscles utilizing the same exercise bar 71.
The device is collapsable and may be folded for compact storage prior to purchase, when not in use, or if it is desired to have the equipment moved or removed yet extends to take advantage of available space. This is best shown diagrammatically in FIGS. 6, 7, 8 and 9. In FIG. 6, the frame 10 is shown having a square configuration, maintained by the structural cable arrangements 28, 50. The upper track 12 is coupled to a slider 54 as shown in FIG. 5 with a thumbscrew which allows the upper track 12 to be moved, adjacent the back end, downwardly to the posiiton as shown in FIG. 7. Similarly, sliders 54 coupled to the short upright elements 38 may be loosened by thumbscrews 53 and then moved laterally from the front end 32 to the back end 34 of the lower tracks 16 as shown in FIG. 8. The segments 43 of the lower tracks 16 are hinged and may then be folded toward the back end for compact storage.
Thus, an exercising device has been described which generally utilizes the active involvement of a second person. No additional weights are necessary since the exercising weight is supplied by the partner and moderated by the multiple pulley banks and the adjustable friction block. The advantages of this involvement are likely to create a motivation to engage in exercising and thus encourage physical fitness.
While the invention has been particularly shown and described with reference to particular examples thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
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Exercising apparatus includes a collapsible frame having upper and lower tracks supporting upper and lower groups of pulleys and moveable upright track supporting risers. The upper pulleys support an adjustable friction block partner supporting harness adjacent the frames front end, and a line extending from the friction block over upper pulleys to a coupling transmits a friction block enhanced force related to the partners weight. A multiple path pulley arrangement joined to the coupling provides a mechanical advantage, reducing by a multiple the effective force delivered adjacent the frame's back end to an exercising bar spaced apart from the exercising partner through lower track coupled pulley blocks. A separate line from the upper track passing through an offset pulley, is extendable to the lower lines to allow for pull down exercises. In use, a partner sits on the harness transmitting a force to the adjustable friction block which is enhanced and transmitted though the multiple pulley paths, thereby reducing the effective resistive force. That force is transmitted to exercising bars lifted or pulled by the exercising individual.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/210,868, filed Mar. 23, 2009, which is incorporated, in its entirety, by this reference.
STATEMENT REGARDING FEDERAL FUNDING
[0002] The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of (contract No. or Grant No.) awarded by (Agency).
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates generally to improvements in seed and seed-related products, processes for making such products, and processes for establishing and improving seed beds. This invention is also directed at improving seed establishment on post-fire water-repellent soil.
[0005] 2. Background Art
[0006] Effective reseeding efforts are important for establishing desirable plant species on agricultural, rangeland, forested land, urbanized areas (i.e. turf), and dry spots. However, these efforts are often encountered with specific problems that include the development of hydrophobic soil layers that prevent effective seed germination and plant establishment. For example, in the western United States, the widespread expansion and stand infilling by pifion ( Pinus ) and juniper ( Juniperus ) (P-J) species into grassland and sagebrush communities constitutes one of the greatest modern-day afforestations. Since European settlement of the Western U.S., P-J species have expanded their range to more than 40 million hectares (Romme, W. H., C. D. Allen, J. D. Bailey, W. L. Baker, B. T. Bestelmeyer, P. M. Brown, K. S. Eisenhart, M. L. Floyd, D. W. Huffman, B. F. Jacobs, R. F. Miller, E. H. Muldavin. T. W. Swetnam, R. J. Tausch, and P. J. Weisberg. 2009. Historical and modern disturbance regimes, stand structures, and landscape dynamics in pinon-juniper vegetation of the Western United States. Rangeland Ecology and Management 62:203-222). This ecosystem shift has resulted in negative impacts to soil resources, plant community structure and composition, forage quality and quantity, water and nutrient cycles, wildlife habitat, and ecological biodiversity. As P-J woodlands mature, increased fuel loads and canopy cover can lead to large-scale, high intensity crown-fires (Miller, R. F., R. J. Tausch, D. Macarthur, D. D. Johnson, S. C. Sanderson. 2008. Development of post settlement pifion-juniper woodlands in the Intermountain West: a regional perspective. USDA Forest Service, Research Paper Report RMRS-Rp-69). After a fire, the ability of desirable plant communities to recover depends on the extent to which physical and biological processes controlling ecosystem function have been altered, both prior to and as result of the fire (Briske, D. D., S. D. Fuhlendorf, and F. E. Smeins. 2005. A unified framework for assessment and application of ecological thresholds. Rangeland Ecology and Management 59:225-236).
[0007] Like P-J woodlands, these cultivated and wildlands may experience similar alterations to both physical and biological structure and process. Reseeding techniques are needed that increase plant establishment, in particular when associated with altered soil properties such as hydrophobic layers. In the case of P-J forests, low seed establishment in hydrophobic soils can lead to undesirable ecological thresholds. When this threshold is crossed, the recovery of desirable species may not be possible without direct human intervention. If sites remain disturbed and unvegetation for a year or more, sites can transition into a secondary state of weed dominance, which then promotes more frequent fire return intervals and decreased native plant establishment, further impairing vital ecosystem function (Young, J. A., and R. A. Evans. 1978. Population dynamics after wildfires in sagebrush grasslands. Journal of Range Management 31:283-289).
[0008] Restoring desired species, recovering natural processes, and preventing movement toward undesirable thresholds is accomplished with the successful establishment of desirable vegetation. In the past, land managers have typically selected introduced species such as crested wheatgrass ( Agropyron cristatum (L.) Gaertn.) and forage kochia ( Bassia prostrata (L.) A. J. Scott). These species often have more consistent establishment, lower costs, better weed competition, and improved livestock forage quality. Currently, many federal and state organizations are increasing the use of native plant materials in place of introduced species in an effort to reinstate ecosystem processes and improve species diversity (Thompson, T. W., B. A. Roundy, E. D. McArthur, B. D. Jessop, B. Waldron, J. N. Davis. 2006. Fire rehabilitation using native and introduced species: A Landscape Trial. Rangeland Ecology and Management 59:237-248), however, these species are costly and establishment success is typically less than desirable. Therefore, the use of native species in reseeding efforts typically increases project costs while decreasing the likelihood of successfully-establishing a functional community. These issues reduce the desire of land managers to include native plant materials in rehabilitation projects.
[0009] To improve the success of reseeding efforts, several mechanical and non-mechanical treatments have been proposed with varying degrees of effectiveness. For example, aerial reseeding followed by anchor chaining is commonly practiced for post-fire rehabilitation of P-J woodlands. Although this form of mechanical treatment has been shown to be successful in many situations, the additional disturbance may increase risk of soil erosion by wind and water. Furthermore, economic, cultural, and topographic constraints (i.e. soils are too rocky or steep) prevent the use of this mechanical treatment on a significant portion of the landscape.
[0010] When restoration practices fail, ecological resilience is compromised, and soil loss, weed invasion, and other factors act as triggers that initiate feedback shifts that carry a site across ecological thresholds to undesirable alternate stable states. Land managers throughout the Intermountain West are calling for new techniques that improve establishment of native plant materials to restore habitats and to prevent subsequent weed dominance.
[0011] In order to develop successful restoration approaches, it is critical that the mechanisms which impair vegetation establishment or recovery and the conditions that develop prior to disturbance which lead to crossing ecological thresholds are understood. If the state of an individual site is known in relation to ecological thresholds and possible transitions to other states, capital can be correctly allocated to sites in transition, in order to promote the system's natural ability to recover. Furthermore, an understanding of the mechanisms that prevent recovery will allow the development of resilience-based approaches that promote recovery of ecosystem process and function (Briske, D. D., S. D. Fuhlendorf, and F. E. Smeins. 2005. A unified framework for assessment and application of ecological thresholds. Rangeland Ecology and Management 59:225-236).
[0012] Hydrophobicity, or soil water repellency, is one factor that may significantly limit recovery of plant communities and enhance weed dominance within P-J dominated systems after fire. Soil water repellency is commonly found in arid and semi-arid ecosystems. Post-fire patterns of soil water repellency have been shown to be highly correlated with decreased soil water content, infiltration, and revegetation success (Madsen, M. D. 2010. Influence of soil water repellency on post-fire revegetation success and management techniques to improve establishment of desired species. Dissertation, Brigham Young University, Provo, Utah). We hypothesize that post-fire WR acts as a temporal ecological threshold by impairing establishment of desired species within the first few years after a fire, which then leaves resources available for weed invasion after WR has diminished. Better knowledge of WR in P-J ecosystems is necessary to guide management actions as these woodlands continue to encroach, infill, and mature throughout their adaptable range (Miller et al. 2008).
[0013] Restoration approaches which focus on ameliorating WR could potentially improve the success of native plant materials following reseeding efforts while simultaneously decreasing runoff and soil erosion, and preventing weed domination. Use of commercially available surface active agents (wetting-agents or surfactants) may provide an alternative restoration approach where WR inhibits site recovery. A wide variety of ionic and nonionic wetting-agents are produced commercially, ranging from simple dish soaps to sophisticated polymers chemically engineered to overcome WR. Wetting-agents are generally organic molecules that are amphiphilic (hydrophobic tails and hydrophilic heads). While wetting agents have different modes of action, in the case of soil applications the hydrophobic tail of the wetting-agent chemically bonds to the non-polar water repellent coating on the soil particle, while the hydrophilic head of the molecule attracts water molecules, thus rendering the soil wettable.
[0014] Small plot, post-fire research projects, located in the mountains of southern California, have shown that the application of wetting-agents after a fire can reduce soil erosion and improve vegetation establishment (Osborn, J. F., R. E. Pelishek, J. S. Krammes, and J. Letey. Soil wettability as a factor in erodibility. Soil Science Society of America Proceedings 28:294-295). These studies suggest that wetting-agent applications can be a successful post-fire treatment. While wetting-agents have not been used in wildland systems since the 1970's, they have been extensively used and further developed within various aspects of the agricultural industry, with most applications in turf grass systems (Kostka, S. J. 2000. Amelioration of water repellency in highly managed soils and the enhancement of turfgrass performance through the systematic application of surfactants. Journal of Hydrology 231-232:359-368). Subsequently, the effectiveness of these chemicals in overcoming soil WR has been improved. The development of these wetting-agents may provide an innovative approach for alleviating the effects of WR on germination and establishment of native vegetation species, thus allowing them to better compete with invasive annual weed species such as cheatgrass ( Bromus tectorum L.).
[0015] The primary objectives of this research were to quantify within a glasshouse setting: 1) the extent that soil water repellency influences emergence and growth of the non-native bunchgrass crested wheatgrass ( Agropyron cristatum (L.) Gaertn., and native bunchgrass, bluebunch wheatgrass ( Pseudoroegneria spicata (Pursh) A. Löve), both of which are commonly seeded for fire rehabilitation, in the Intermountain West, USA; and 2) determine the effects of the newly developed non-ionic wetting-agent “Soil Penetrant” (Aquatrols Inc., Paulsboro, N.J.) on WR and seedling growth to assess its potential use in wildfire rehabilitation of P-J ecosystems.
[0016] Water repellence in relation to fire. After a fire, the ability of ecosystem to recover is dependent on the extent to which ecological processes have been altered. Modification of the soil through the development of a hydrophobic layer is one alteration which can significantly limit site recovery. Wildland vegetation can create a hydrophobic layer in the first few centimeters of the soil profile.
[0017] During a fire, heat can volatilize organic substances within the litter and upper hydrophobic soil layers. These volatilized compounds then move downward into the soil, condensing within the cool underlying soil layers. This results in a wettable layer at the soil surface and an intensified hydrophobic zone a few centimeters below the soil surface. The development or enhancement of this hydrophobic layer has severe implications for revegetation success, runoff, and soil erosion. Seeds which germinate within the soils upper wettable layer typically desiccate, as a result of the water repellent layer disconnecting the seedling from the underlying soil moisture reserves ( FIGS. 2A and 8A ). The lack of seedling establishment allows for continued soil erosion and provides the opportunity for invasion of annual weeds in subsequent years, when sown seeds are no longer viable.
[0018] The arrangement of a wettable soil layer overlying a water repellent layer also has severe implications for water runoff and soil stability. During a rainfall event the upper wettable layer is quickly saturated due to the underlying water repellent layer impeding infiltration. On steep slopes, when this wettable layer becomes saturated from high intensity rainfall events, water, soil, and debris can quickly flow down slope, which causes site degradation and property damage if it is within the wildland urban interface.
[0019] Large amounts of public funds are spent each year on postfire rehabilitation treatments. Currently, post-fire rehabilitation treatments include providing immediately surface cover by straw mulching, hydromulching and other methods. However, these methods are expensive; for example straw mulching has been shown to range between $1000 per hectacre and $3000 per hectacre and hydromulching can range between $2350 per hectacre to $4700 per hectacre. Consequently, applying such strategies can be almost impractical at large scales. Thus, there is currently a need for effective postfire rehabilitation treatments which can be applied at the landscape scale which ameliorate the influence of hydrophobic soil and establish desirable plants back into the system.
[0020] Use of commercially available soil surfactants may provide an alternative postfire restoration approach where hydrophobicity and limited soil moisture availability are preventing site recovery. Soil surfactant molecules are hydrophobic on one end and hydrophilic on the other end. Upon entering the soil the hydrophobic end of the soil surfactant chemically attaches to the non-'polar water repellent coating on the soil particle; while the hydrophilic end of the agent is able to attract water molecules allowing soil moisture to be absorbed in the upper hydrophobic soil layers.
[0021] Various small plot postfire research projects located in the chaparral mountains of southern California have shown that the application of soil surfactants after a fire can reduce soil erosion and improve vegetation establishment. These studies suggest that the application of soil surfactants can be a successful postfire treatment. While soil surfactants have not been used in wildland systems since the 1970's, they have been extensively used and further developed in various aspects of the agricultural industry, with particular use in turf production. Subsequently, the effectiveness of these chemicals in diminishing soil hydrophobicity has been improved. The development of these soil surfactant products may provide an innovative approach for alleviating the effects of hydrophobicity on runoff and soil erosion, and allow native vegetation species, the ability to better compete with invasive annual weed species such as cheatgrass ( Bromus tectorum ). While these results are promising, application of soil amendments is typically not practical for the revegetation of wildland systems, due to the large areas and low economic value of the land to be treated. Commercially available soil surfactant products are particularly costly. Furthermore, the application of these chemicals to a wildland landscape is difficult at best.
SUMMARY OF THE INVENTION
[0022] Preferred embodiments include compositions with at least one seed and at least one coating, which is a wetting agent. Other coatings can be added as other embodiments. Various wetting agents can be used to treat hydrophobic soil (or even increase moisture in nonhydrophobic soils). In a preferred embodiment of the invention, wetting agents are attached or coated to a seed and then the coated seed is delivered to the hydrophobic patch of soil. Once the wetting agents are released, then the wetting agents can treat the area of hydrophobic soil that is surrounding the seed. Alternatively, the hydrophobic layer can be penetrated by the wetting agents, and the seeds that have been delivered to that spot can then germinate and penetrate. The invention also contemplates agglomerates, which are two or more seeds that have been coated into a single agglomerate. Some advantages of using an agglomerate include: multiple seeds are delivered to a site, and the agglomerate also carries wetting agents and other amendments (plant or soil amendments) so that land with a hydrophobic layer can be treated. In one aspect and embodiment of the invention, the wetting agents are amphipilic and contain hydrophobe portions and hydrophile portions. The hydrophobe portions of the wetting agent allow the wetting agent to be attracted to the hydrophobic soil, and the hydrophile portions of the wetting agent facilitate the accumulation of water around the wetting agent.
[0023] In some embodiments, the wetting agent is one or more one nonionic surfactants; in other embodiments the invention has at least one nonionic surfactant is selected from the group consisting of copolymers, block copolymers, alcohol ethoxylates, nonylphenol ethoxylates, ethylene oxide/propylene oxide block copolymers, and alkylpolyglycosides.
[0024] Other embodiments comprise a soil amendment or plant amendment selected from the group consisting of 2-butoxyethanol, alkylpolyglycosideamino acids, ammonium laureth sulfate, bio-stimulants, block co-polymers, blended non-ionic, ionic surfactants, enzymes, ethylene oxide/propylene oxide, fermentation products, fulvic acid, granular soil surfactants, hormones, humic acid, liquid soil surfactants, microorganisms, nonylphenolpolyethoxylate, nontoxic ingredients, non-ionic surfactants, nutrients, oleic acid, surfactants, soil conditioners, soil microbes, microbial innoculants, stimulants that are beneficial to microbial growth, soil surfactants, super-hydrating soil surfactants, tackifiers, turf soil surfactants, penetrants, poloxanlene, re-soil surfactants, root stimulants, spreaders, vitamins, agrichemical seed treatments, fungicide, insecticides, plant protectants, and absorbent polymers.
[0025] Other embodiments have at least one carrier is selected from the group consisting of transition powders, blends of montmorillonite, oil absorbents, a blend containing about 65% of −325 RVM (or, alternatively, sorbent mineral powders such as montmorillonite, attapulgite or diatomite) and about 35% powdered limestone or other powder carrier by volume, montmorillonite clay, potato starch, molecular sieves, diatomaceous earth, talc, mica, lime, and bentonite.
[0026] Other preferred embodiments have an agglomerate of more than one seed, wherein said at least one wetting agent is at least one ingredient that is selected from the group consisting of ionic surfactants, nonionic surfactants, amphiphilic surfactants, and surfactants with an hydrophilic-lipophilic balance (HLB) value greater than 2 and less than 18.
[0027] Other preferred embodiments have at least one of the following coatings selected from the group consisting of tackifiers, slurry tackifiers, and psyllium tackifier.
[0028] Other preferred embodiments have less than fifty seeds, and wherein said at least one tackifier is selected from the group consisting of mulch tackifiers, tackifier slurries, and psyllium tackifier.
[0029] A preferred embodiment contains a method for preparing a composition, comprising:
providing at least one seed, providing at least one wetting agent, and coating said at least one seed with said at least one wetting agent.
[0033] Other embodiments of the method also have steps for forming an agglomerate of more than one seed by coating said at least one seed with a hydrophilic powder, coating said at least one seed with an adhesive while simultaneously witholding said hydrophilic powder from said seed, aggregating at least one developing agglomerate of more than one seed, and adding said hydrophilic powder to said developing agglomerate wherein a completed agglomerate of more than one seed is formed.
[0034] Other embodiments of the method include said at least one seed is greater than one seed and less than fifty seeds, and wherein an amount of said wetting agent is greater than 3% w/w but less than 2500% w/w.
[0035] Other embodiments of the method include the steps of coating said composition with at least one the following coatings selected from the group consisting of at least one seed protectant layer, at least one binder, at least one carrier, at least one tackifier, at least one outer coating, at least one hydrophobic coating, at least one nutrient, at least one soil stimulant, at least one seed stimulant, at least one plant stimulant, at least one bio-stimulant, and at least one microorganism.
[0036] A preferred embodiment of the invention is a method for ameliorating water repellent soil and increasing water availability in wettable soil, comprising the steps of providing at least oneseed, wherein said at least one seed comprises at least one seed and at least one wetting agent, said at least one wetting agent comprising at least one hydrophobic group and at least one hydrophilic group.
[0037] Another embodiment of the invention includes allowing said at least one seed to lay in said soil, exposing said seed capsule to water, releasing said wetting agent from said seed capsule, and improving moisture availability to the area surrounding the at least one seed.
[0038] In another embodiment of the invention, the said capsule is an agglomerate of more than one seed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIGS. 1A , 1 B, 1 C, 1 D, 1 D, 1 E, 1 F, 1 G, AND 1 H show cross sections of some preferred embodiments of the invention. FIG. 1A depicts a seed that has been coated with a wetting agent. The invention contemplates the coating of a single seed and also the coating of multiple seeds, which is herein called an agglomerate. In FIGS. 1C and 1D , there is shown a single seed with four coatings. The depiction of two seeds is to show that there are many ways that a seed could be coated with multiple coats. Tackifiers are generally found on the outside coat, however it is not required by the invention that tackifiers be on the outside coat. Also, the invention is not limited to only four coats but encompasses a large amount of coatings.
[0040] FIG. 2A shows a cross-section of a seed 1 capsule and a soil profile. FIG. 2A shows a cross-section of a seed that is coated with soil surfactant particles and a soil profile. FIG. 2C shows a cross-section of a seed from a single capsule that has germinated and a soil profile. 1 Also could be a conglomerate
[0041] FIG. 3A shows a soil profile without germinated seeds and FIG. 3B . shows a soil profile with seeds from embodiments of the invention that have germinated and penetrated the water-repellent layer.
[0042] FIG. 2A shows a capsule that is coated with super-hydrating polymers and a wetting agent. The seed capsule is located above a water-repellent layer of soil. FIG. 2B shows a seed capsule that has released soil surfactants into the soil after precipitation has occurred. The soil surfactants have formed a hydrophilic conduit. FIG. 2C shows a seedling that has emerged from the seed of the seed capsule after the seed has germinated. The roots have penetrated the water-repellent layer. The super-hydrating polymers, which are optionally found in embodiments of the invention, have retained water from previous precipitation events for seed germination and seedling growth.
[0043] FIG. 3A shows a water-repellent layer that has impeded infiltration of precipitation. The upper wettable soil layer is now saturated.
[0044] FIG. 3B shows soil that has been treated with seed capsules and/or conglomerate seed capsules. The soil surfactants in the seed capsules and/or the conglomerate seed capsules have created a hydrophilic conduit around the roots and the roots have penetrated through the water-repellent layer.
[0045] FIG. 4A 2 shows some cotyledons that have penetrated the soil crust layer to a limited degree and the seeds have died. FIG. 4B shows cotyledons from multiple seeds that have conglomerated into a single pellet, and the single pellet of multiple seeds collectively generates sufficient force to penetrate through the soil crust layer. FIG. 4C shows non-coated seeds which have germinated at or near the soil surface. The radicals have not fully-penetrated the soil crust layer. The non-coated seeds are elevated and have been pushed along the soil surface as the radical grows. Without radical penetration into the soil the seedlings have quickly desiccated. FIG. 4D shows a conglomerate seed capsule that has greater mass then a non-conglomerate seed capsule and tackifiers that are present as a layer in the conglomerate seed capsule anchors or glues the seed to the soil surface once the soil surface has become wet. By attaching the seed to the soil necessary leverage is provided for the radical to penetrate into the soil, thus increasing seedling survival.
[0046] FIG. 5 shows on the left side some upright seedlings that germinated from the seeds that were in a conglomerate seed capsule and on the right side a fallen seedling that germinated from a single seed that was in a seed capsule.
[0047] FIG. 6 shows a schematic representative flow diagram illustrating multiple manufacturing processes for producing seed capsules and conglomerate seed capsules.
EXPLANATION OF THE NUMBERING IN THE FIGURES
[0000]
100 : the water repellent layer (also known as a hydrophobic layer)
110 : the upper wettable layer also known as topsoil
120 : lower wettable layer
130 : wetting agents, also known as soil surfactants
150 : hydrophilic conduit
DETAILED DESCRIPTION OF THE INVENTION
[0053] Preferred embodiments of the invention encompass a method for making a composition which can be utilized for treating seed, the composition, and methods for using the composition. For purposes of the present description the term “seed” is not limited to a particular type of seed and can refer to seed from a single plant species, a mixture of seed from multiple plant species, or a seed blend from various strains within a plant species. The described compositions can be utilized to treat gymnosperm seed, dicotyledonous angiosperm seed and monocotyledonous angiosperm seed. Compositions according to the present invention can be particularly useful for treatment of seed and seeds which will be utilized in applications including but not limited to home gardening, crop production, forestry applications, turf, golf courses, and government rehabilitation programs.
[0054] Units, prefixes, and symbols may be denoted in their SI accepted form. Numeric ranges recited herein are inclusive of the numbers defining the range and include and are supportive of each integer within the defined range. Unless otherwise noted, the terms “a” or “an” are to be construed as meaning “at least one of”. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including but not limited to patents, patent applications, articles, books, and treatises, are herein expressly incorporated by reference in their entirety for any purpose.
[0055] The foregoing techniques and procedures are generally performed according to conventional methods well known in the arts of botany and forestry.
[0056] The following definitions are given by way of example and not as limitations. As utilized in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings:
DEFINITIONS
[0057] Binder: Binders are also known as adhesives. Some nonlimiting examples of binders include: adhesive polymers that may be natural or synthetic and preferably do not phytotoxically effect the seed to be coated. In one embodiment, the binder may be a molasses, granulated sugar, alginates, karaya gum, jaguar gum, tragacanth gum, polysaccharide gum, mucilage or combination thereof. In another embodiment, the binder may be selected from polyvinyl acetates, polyvinyl acetate copolymers, polyvinyl alcohols, polyvinyl alcohol copolymers, celluloses, including ethylcelluloses and methylcelluloses, hydroxymethyl celluloses, hydroxypropylcelluloses, hydroxymethylpropyl-celluloses, polyvinylpyrolidones, dextrins, malto-dextrins, polysaccharides, fats, oils, proteins, gum arabics, shellacs, vinylidene chloride, vinylidene chloride copolymers, calcium lignosulfonates, acrylic copolymers, starches, polyvinylacrylates, zeins, gelatin, carboxymethylcellulose, chitosan, polyethylene oxide, acrylimide polymers and copolymers, polyhydroxyethyl acrylate, methylacrylimide monomers, alginate, ethylcellulose, polychloroprene and syrups or mixtures thereof; polymers and copolymers of vinyl acetate, methyl cellulose, vinylidene chloride, acrylic, cellulose, polyvinylpyrrolidone and polysaccharide; polymers and copolymers of vinylidene chloride and vinyl acetate-ethylene copolymers; combinations of polyvinyl alcohol and sucrose; plasticizers such as glycerol, propylene glycol, polyglycols. The plasticizer, when added, comprises from about 0.5% to 10% w/w of the binder. Binders also known as adhesive
[0058] Soil Surfactants: Soil surfactants are also known as wetting agents; some examples of soil surfactants are: 2-butoxyethanol, alkylpolyglycosideamino acids, ammonium laureth sulfate, B-complex vitamins, bio-catalysts, bio-stimulants, block co-polymers, blended non-ionic, ionic surfactants, enzymes, ethylene oxide/propylene oxide, fermentation products, fulvic acid, granular soil surfactants, hormones, humic acid, liquid soil surfactants, microorganisms, nonylphenolpolyethoxylate, nontoxic ingredients, non-ionic surfactants, nutrients, oleic acid, surfactants, soil conditioners, soil surfactants, super-hydrating soil surfactants, turf soil surfactants, penetrants, poloxanlene, re-soil surfactants, root stimulants, spreaders, and vitamins.
[0059] Compositions according to the present invention can comprise one or more macronutrients. For purposes of the present description, the term “macronutrient” can refer to an element for plant growth which is utilized by plants in proportionally larger amounts relative to micronutrients. For most plant species and for purposes of the present description, macronutrients include nitrogen, potassium, phosphorus, calcium, magnesium and sulfur. Compositions of the present invention can include various combinations and relative amounts of individual macronutrients. Preferably, compositions include both phosphorous and potassium. In particular embodiments, compositions of the present invention include each of the listed macronutrients.
[0060] An aspect of the invention include agglomerates: We have started developing a new coating technique which groups multiple seeds together into a conglomerate (pellets with 3-5 seeds). This of course helps concentrate a large amount of surfactant within a small area to ameliorate the hydrophobic layer, but we are also finding that it helps glue/anchor the seed to the soil surface once it gets wet. A limiting factor for rangeland areal reseeding efforts is that the seeds which germinate at or near the soil surface have poor radical penetration, with the seeds being elevated or pushed along the soil surface as the radical grows. Without radical penetration into the soil the seedlings quickly desiccate. A major benefit to anchoring the seed to the soil is that it provides the leverage necessary for the radical to penetrate into the soil, thus increasing seedling survival . . . . Clumping/pelting seeds together may also promote seedling survival where seeds that are buried below the soil surface (such as through drill seeding) are limited by a physical crust. By clumping multiple seeds together the cotyledons collectively generate sufficient force to penetrate through the physical crust.
[0061] A variety of materials are available to provide macronutrients to the composition. Exemplary substances which may be utilized to provide nitrogen include ammonium sulfate, ammonium nitrate, fish protein digest, ammonium phosphate sulfate, phosphate nitrate, diammonium phosphate, ammoniated single superphosphate, ammoniated triple superphosphate, nitric phosphates, ammonium chloride, calcium nitrate, calcium cyanamide, sodium nitrate, urea, urea-ammonium nitrate solution, nitrate of soda potash, potassium nitrate, amino acids, proteins, nucleic acids and combinations thereof. Commercially available fish protein digests that can be utilized in compositions of the invention include, for example, SEA-PROD™ (Soil Spray Aid, Inc., Moses Lake, Wash.); MERMAID™ (Integrated Fertility Management (IFM), Wenatchee, Wash.); and OCEAN HARVEST™ (Algro Farms, Selah, Wash.).
[0062] Exemplary phosphate materials that can be utilized include mono-potassium phosphate, superphosphate (single/double or triple), phosphoric acid, ammonium phosphate sulfate, ammonium phosphate nitrate, diammonium phosphate, ammoniated superphosphate (single, double or triple), nitric phosphates, potassium pyrophosphates, sodium pyrophosphate, nucleic acid phosphates, and combinations thereof.
[0063] Exemplary potassium materials which can be utilized include mono-potassium phosphate, potassium chloride, potassium sulfate, potassium gluconate, sulfate of potash magnesia, potassium carbonate, potassium acetate, potassium citrate, potassium hydroxide, potassium manganate, potassium molybdate, potassium thiosulfate, potassium zinc sulfate, and combinations thereof.
[0064] Calcium containing materials that can be utilized in compositions of the invention include, but are not limited to, powdered milk, calcium ammonium nitrate, calcium nitrate, calcium cyanamide, calcium acetate, calcium acetylsalicylate, calcium borate, calcium borogluconate, calcium carbonate, calcium chloride, calcium citrate, calcium ferrous citrate, calcium glycerophosphate, calcium lactate, calcium oxide, calcium pantothenate, calcium propionate, calcium saccharate, calcium sulfate, calcium tartrate, and mixtures thereof.
[0065] Exemplary magnesium materials for utilization in compositions of the present invention include magnesium sulfate, magnesium oxide, dolomite, magnesium acetate, magnesium benzoate, magnesium bisulfate, magnesium borate, magnesium chloride, magnesium citrate, magnesium nitrate, magnesium phosphate, magnesium salicylate, and combinations thereof.
[0066] Exemplary sulfur containing materials for utilization in the compositions include magnesium sulfate, ammonium phosphate sulfate; calcium sulfate, potassium sulfate, sulfuric acid, cobalt sulfate, copper sulfate, ferric sulfate, ferrous sulfate, sulfur, cysteine, methionine, and combinations thereof.
[0067] Compositions of the present invention can comprise one or more micronutrients. For purposes of the present invention the term “micronutrients” refers to an element utilized by plants during growth which are used in smaller amounts relative to macronutrients. Typically, and for purposes of the present description, plant micronutrients include iron, manganese, zinc, copper, boron, molybdenum and cobalt. Numerous compounds and substances are available to provide micronutrients to compositions of the present invention. Exemplary zinc containing compounds include chelated zinc, zinc sulfate, zinc oxide, zinc acetate, zinc benzoate, zinc chloride, zinc bis(dimethyldithiocarbamate), zinc citrate, zinc nitrate, zinc salicylate, and combinations thereof.
[0068] Exemplary iron containing materials which can be utilized in compositions of the present invention include chelated iron, ferric chloride, ferric citrate, ferric fructose, ferric glycerophosphate, ferric nitrate, ferric oxide, ferrous chloride, ferrous citrate, ferrous fumarate, ferrous gluconate, and ferrous succinate, and combinations thereof.
[0069] Exemplary manganese containing materials which can be utilized include manganese sulfate, manganese acetate, manganese chloride, manganese nitrate, manganese phosphate, and combinations thereof.
[0070] Exemplary cobalt materials which can be utilized in compositions of the present invention include cyanocobalamin, cobaltic acetate, cobaltous chloride, cobaltous oxalate, cobaltous potassium sulfate, cobaltous sulfate, and combinations thereof.
[0071] Various combinations and relative amounts of micronutrients can be utilized in the compositions of the present invention. Preferably, compositions include at least zinc, iron and manganese, and in particular embodiments the compositions comprises at least zinc, iron, manganese and cobalt.
[0072] The presence and amounts of individual macronutrients and micronutrients in a particular composition can vary depending on factors such as the condition of the soil from which the seed was produced and the soil conditions existing where the seed will be planted. For example, if a seed is to be planted in an area that is known to be deficient in one or more macronutrients or micronutrients, the corresponding macronutrients and micronutrients can be provided in the composition in amounts sufficient to partially or completely compensate for such deficiency. A deficiency in one or more nutrients can also occur within a seed when such seed has been produced under conditions where the soil is deficient in those nutrients. When such intra-seed deficiency exists, the corresponding macronutrients and micronutrients in which the seed is deficient can be provided within compositions of the invention, in amounts sufficient to partially or completely compensate for such deficiency.
[0073] It is not unusual for the soil conditions from whence seed originated to be unknown. Additionally, a seed supply can contain seed originating from numerous locations. Further, it may be unknown at the time of treating seed where the particular seed will be planted. Accordingly, it can be advantageous to provide individual macronutrients and micronutrients to the composition in an amount sufficient to alleviate potential deficiencies. It can be most preferred to provide all the listed micronutrients and macronutrients in the composition with each present in an amount sufficient to at least partially compensate for any deficiency in the corresponding nutrient, whether the deficiency occurs in the soil from whence the seed originated or in the soil into which the seed will be planted. Conversely, if soil conditions are known to be such that any individual nutrient is present in abundance, and that supplemental amounts will not further benefit the seed, such nutrient can be omitted from the composition.
[0074] Compositions of the present invention can further contain any of a number of vitamins and cofactors important for plant germination and growth. For purposes of the present description the term “cofactor” can be referred to as a metal ion cofactor, a coenzyme or a coenzyme precursor. Exemplary vitamins and cofactors for utilization in compositions of the present invention include thiamine, riboflavin, niacin (nicotinic acid and/or niacinamide), pyridoxine, panthenol, cyanocobalamin, citric acid, folic acid, biotin and combinations thereof. Preferably, compositions of the present invention comprise each of folic acid, biotin, panthenol (and/or panthothenic acid), riboflavin and thiamine. More preferably, the composition can comprise some form of each of the listed vitamins and cofactors.
[0075] The listed vitamins and cofactors can be provided in the composition in any form including vitamin derivatives and provitamin forms. Optionally, one or more alcohols can be utilized in the composition to enhance the activity and aid in the preservation of one or more vitamins. An exemplary alcohol which may be utilized is benzyl alcohol.
[0076] Exemplary forms of thiamine which can be utilized in compositions of the present invention include thiamine hydrochloride, thiamine pyrophosphate, thiamine monophosphate, thiamine disulfide, thiamine mononitrate, thiamine phosphoric acid ester chloride, thiamine phosphoric acid ester phosphate salt, thiamine 1,5 salt, thiamine triphosphoric acid ester, thiamine triphosphoric acid salt, yeast, yeast extract, and various combinations thereof.
[0077] Exemplary forms of riboflavin for utilization in compositions of the present invention include riboflavin, riboflavin acetyl phosphate, flavin adenine dinucleotide, flavin adenine mononucleotide, riboflavin phosphate, yeast, yeast extract and combinations thereof.
[0078] Niacin materials which can be comprised by compositions of the present invention include but are not limited to niacinamide, nicotinic acid, nicotinic acid adenine dinucleotide, nicotinic acid amide, nicotinic acid benzyl ester, nicotinic acid monoethanolamine salt, yeast, yeast extract, nicotinic acid hydrazide, nicotinic acid hydroxyamate, nicotinic acid-N-(hydroxymethyl)amide, nicotinic acid methyl ester, nicotinic acid mononucleotide, nicotinic acid nitrite and combinations thereof.
[0079] Pyridoxine and substances which can be utilized in compositions of the invention include pyridoxine hydrochloride, pyridoxal phosphate, yeast and yeast extract. Folic acid materials that can be utilized for compositions of the present invention include but are not limited to folic acid, yeast, yeast extract and folinic acid.
[0080] Biotin compounds and materials which can be utilized in compositions of the present invention include biotin, biotin sulfoxide, yeast, yeast extract, biotin 4-amidobenzoic acid, biotin amidocaproate N-hydroxysuccinimide ester, biotinyl 6-aminoquinoline, biotin hydrazide, biotin methyl ester, d-biotin-N-hydroxysuccinimide ester, biotin-maleimide, d-biotin p-nitrophenyl ester, biotin propranolol, 5-(N-biotinyl)-3-aminoallyl)-uridine 5′-triphosphate, biotinylated urdidine 5′-triphosphate, N-e-biotinyl-lysine, and combinations thereof.
[0081] Panthothenic acid materials for utilization in the compositions can include yeast, yeast extract and coenzyme A. Exemplary cyanocobalamin materials include but are not limited to yeast and yeast extract.
[0082] Compositions of the present invention can comprise seaweed extract to provide one or more growth regulators and various amino acids, to the composition. Growth regulators provided by the seaweed extract can include cytokinins, auxins, and gibberellins. It can be advantageous to provide seaweed extract to the composition to supply growth regulators and amino acids in a single source. It is to be understood however that the invention contemplates utilization of multiple sources to provide the various growth regulators and amino acids. Individual amino acids which can be added independently or in combination include alanine, arginine, aspartic acid, cysteine, glycine, glutamic acid, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, tryptophan, tyrosine and valine.
[0083] Various seaweed extracts are commercially available which can be utilized in compositions of the present invention. Either cold or hot processed seaweed extract can be utilized. Exemplary commercially available seaweed extracts which can be utilized in compositions of the present invention include ACADIAN™, produced by Acadian Sea Plants Limited, Dartmouth, Nova Scotia, Canada; MAXICROP®, produced by Maxicrop International Limited, Corby Northamptonshire, UK; and ALGEA®. produced by Algea A.S., Oslo, Norway.
[0084] Formulations encompassed by the present invention can comprise a variety of plant extracts. Exemplary extracts include cayenne pepper, lemon extract, garlic extract and peppermint oil. Alternatively, these ingredients can be included in the composition in powdered form. The addition of one or a combination of the listed plant extracts can advantageously inhibit various pests such as birds, rodents and insects without detrimental effects on the seed. The inclusion of one or more of these pest inhibitors can be particularly advantageous when techniques such as aerial planting are utilized where seed is distributed without drilling the soil or covering the seed. Additionally, plant extracts such as garlic extract can inhibit molding. Extracts such as lemon extract and citric acid can function as penetrants, and peppermint and lemon can confer a more pleasant odor to the resulting formulation.
[0085] A water absorbant can be included in compositions of the present invention. Numerous absorbants are available for utilization in compositions of the present invention. Exemplary absorbants include various starches and starch copolymers. Particular compositions can comprise a starch-acrylate copolymer, such as starch potassium acrylate copolymer.
[0086] A penetrant can be included in compositions of the present invention. Numerous penetrants are available for utilization including, but not limited to, dimethylsulfoxide (DMSO). Because of their ability to act as penetrants, lemon extract and citric acid can be utilized as penetrants in the composition, and can optionally be utilized in combination with one or more additional penetrants.
[0087] Compositions of the present invention can optionally comprise one or more mold inhibitors. Numerous mold inhibitors are available for utilization in compositions of the present invention. Preferably, a mold inhibitor can comprise one or more of a dimethylhydantoin derivative and nipicide (o-benzyl-p-chlorophenol). It can be advantageous to utilize dimethylhydantoin, nipicide or mixtures thereof due to the relatively low toxicity of these compounds as compared to alternative mold inhibitors. In particular embodiments, it can be preferable to utilize dimethylhydantoin in an absence of nipicide due to nipicide's unpleasant odor.
[0088] Compositions of the present invention can additionally comprise various carbohydrates. Exemplary carbohydrates include algin acid, mannitol and laminarin, each of which is present in seaweed extract. It is to be understood that the compositions of the present invention encompass utilization of other carbohydrates which can be present independently or in combination with the carbohydrates provided by the seaweed extract.
[0089] Compositions of the present invention can further comprise at least one of humic acid and fulvic acid. In particular compositions, humic acid can preferably be included to chelate trace elements and thereby inhibit formation of complexes between the trace elements and other components such as, for example, sulfates. Humic acid can additionally be utilized as a source of carbon during seed germination and plant growth.
[0090] Fulvic acid can be utilized to achieve a desired pH of the composition. Compositions according to the present invention are not limited to a particular pH, can preferably comprise an acidic pH, and more preferably have a pH between about 5.3 and about 6.8. A pH in the range of from about 5.3 to about 6.8 can be beneficial since this pH range can inhibit complex formation between trace elements and other components such as sulfates. It can be advantageous to utilize fulvic acid to adjust the pH since fulvic acid can additionally be utilized as a carbon source. It is to be understood, however, that the invention contemplates utilization of alternative or additional agents for adjusting pH of the composition.
[0091] Compositions of the present invention are preferably formulated in the form of an aqueous solution. The amount of added water utilized in composition formation will depend upon the particular components and whether the components are in a dry form, in a liquid form or in solution when added to the formulation.
[0092] It is to be understood that the specific amount of each component indicated in the table is within a preferred range for the specific material utilized in the embodiment. When the sources listed are utilized for producing the composition, the amount indicated is the amount most preferred and is within a preferred range that includes a deviation of up to about +/−25% from the specified amount.
[0093] Preparation of Compositions According to the Present Invention is not Limited to any specific order of addition of components. In particular aspects it can be preferable to form an initial mixture. Preferably, micronutrients are added individually, however, the order of their addition can be arbitrary. After formation of the initial mixture, the remaining components can be added. Mixing is preferably continued throughout the addition of components.
[0094] For example, current methods of treating seeds include encapsulating seeds with a coating to form a seed “capsule”. The seed capsule can be formed primarily to provide a uniform seed size, shape or both. Encapsulation can be advantageous to produce a smoother and or rounder shape which can assist in the passing of the seed through various seed processing and planting equipment. Compositions of the present invention can be added to materials used for encapsulation and the combined mixture can be used for simultaneous treatment and encapsulation of seeds. Alternatively, seed treatment of the present invention can be applied to seed independently of the encapsulation material, preferably prior to encapsulation.
[0095] Optionally, a storage step can be included whereby the treated seed is stored prior to planting. In particular instances it can be advantageous to store treated seed prior to planting. Germination rates of seed can vary depending upon the length of time a seed has been stored between harvesting of the seed and subsequent planting of the seed. For purposes of the present description the term “germination rate” refers to the percent of a seed population that germinates. Various types of seed can have different optimal storage periods for maximization of the germination rate of the seed. As an example, seed such as wheat achieves an optimal germination rate about two growth seasons after seed harvest. In other words, if the wheat is harvested in the fall of year one and the harvested seed is planted in the fall of year two or spring of year three, the germination rate will be higher than if the seed was planted earlier. Additionally, the planting period to achieve optimal germination rates are often brief, with germination rates declining with increased storage time beyond the optimal year. Therefore, it can be beneficial to store the seed and plant the seed within the optimal period to maximize germination rates.
[0096] Optimal planting time for maximization of seed germination rate will vary based upon specific seed type. Additionally, certain seeds such as cereal grains have intrinsically high germination rates relative to other seed types. Accordingly, for some seed types it can be preferable to store the seed through one or more growing seasons prior to planting based on the optimal planting period for the particular seed.
DEFINITIONS
Coaters
[0097] According to the present invention, the seeds are substantially uniformly coated with one or more of the aforementioned layers of compositions using conventional methods of mixing, spraying or a combination thereof. Various coating machines are available which may utilize various coating technology through the use of rotary coaters, drum coaters, fluidized bed techniques, spoutedbeds or a combination thereof.
[0098] The seeds may be coated via a batch or continuous coating process. In one embodiment, uncoated seeds enter the coating machine in a steady stream to replace coated product that has exited the machine. Additionally, a computer system may monitor the seed input to the coating machine, thereby maintaining a constant flow of the appropriate amount of seed. In an alternative embodiment, the seed coating machinery can optionally be operated by a programmable logic controller that allows various equipment to be started and stopped without employee intervention. The components of this system are commercially available through several sources.
[0099] In one embodiment, seeds are first separated by mechanical means such as a sieve. The separated small seeds are then introduced into a coating machine via an infeed chute that allows for precision metering of incoming seeds. After passing through the infeed chute, the seed enters a mixing bowl. In one embodiment, the mixing bowl is one or more cylinders with a rotating base. One or more coating compositions are then introduced to the mixing bowl via a powder feeder and/or solution pumps. In one embodiment, the powder feeder applies the one or more coating compositions to the seeds as the seed mass rotates in the mixing bowl. In a preferred embodiment, the seeds are combined with one or more of the coating compositions and adhered with the binder within a mixing bowl. Either the operator or a computer system may verify and coordinate any batching, mixing, and pumping of the solutions containing one or more of the coating layer compositions.
[0100] In one embodiment of the process, all three layer compositions are sequentially added. Preferably, the base layer comprising a polyvinyl alcohol and sucrose binder as well as a pumice are added to the mixing bowl containing one or more seeds. The intermediate and outer compositions are then introduced sequentially to the rotating drum. The intermediate composition preferably comprises talc or mica while the outer layer preferably comprises graphite alone or in combination with a magnesium silicate such as talc. In one embodiment, the seeds are polished by retaining the seeds in the mixing bowl for an extended period of time resulting in an improved appearance.
[0101] After application of one or more of the layers described herein, the seed exits the mixing bowl and is moved to a drying apparatus where the seed is dried. In one embodiment, the dried seeds are transferred back to the infeed chute for subsequent coating. Preferably, the size variation among seeds presented to the purchaser is less than about 15% and more preferably less than about 5%.
METHODS
Wetting Agent Coatings
[0102] Seed coating or pelleting methods within the present invention involve the use of a rotary seed coater; however, other seed coating devices such as coating pans or tumbling drums, fluidized bed techniques, and agglomerators may also be used. Coating is performed within the rotary coater by placing seeds within a coating chamber (mixing bowl), of which the bottom rotates creating centrifugal forces and therefore pushing the seed upward and outward against the inside wall of the chamber. Centrifugal forces and mixing bars placed inside the coater cause the seed to rotate and mix. Adhesive (binder) or other liquid seed coating materials are pumped into the center of the coater onto an atomizer disk that rotates in the opposite direction of the bottom of the coating chamber. Upon hitting the atomizer disk, liquid adhesive is then directed outward in small drops onto the seed. A feeder then applies powder onto the seed to prevent seeds from attaching to one another and allowing for increased buildup of the coating material.
[0103] Methods for applying nonionic wetting agent to the seed comprise first coating seed with a plant protectant consisting of a powder coating attached to the seed with adhesive (binder), to physically separate the active ingredient (i.e. wetting agent) from contact with the seed surface until germination. There may also be several powders adequate for use as a seed protectant, such as diatomaceous earth, gypsum, chalk, clays, perlite, talc, quartz or a combination of powders. There are several binders that may be utilized for this invention. This technique of applying a seed protectant is typically known as pellet loading. While it is not necessary that this step be performed, application can help prevent germination delay and increase seed storage life by improving seed respiration.
[0104] To further increase seed moisture availability super hydrating polymers (SHP's) can be added to the powder used for the seed protectant. SHP's can be added at commercial supplier recommended rates and several times higher due the synergistic effects with soil wetting agent which is applied latter in the coating process.
[0105] It is the primary intention of this invention to provide methods for coating nonionic soil wetting agents; however, methods also can be applied for other wetting agent types such as ionic wetting agents, and amphiphilic wetting agents.
[0106] Prior to coating wetting agent onto the seed a powder and binder are lightly coated over the outside of the seed protectant coat. This step is noted in the flow diagram as “transition powder” which consists of a blend containing the oil absorbent material such as powdered (Oil-Dri Corporation of America, Alpharetta, Ga.) and powdered limestone or other powder carrier. The oil absorbent −325 RVM (or, alternatively, sorbent mineral powders such as montmorillonite, attapulgite or diatomite) is used in this invention because of its high absorbent properties for soil wetting agent; however, other powders could be used in place of −325 RVM (or, alternatively, sorbent mineral powders such as montmorillonite, attapulgite or diatomite). By attaching the high absorbent powder to the seed the ability of the wetting agent to adhere to the seed is improved.
[0107] Wetting agent is delivered to the seed through direct injection onto the atomizer disk, while the same mix used for the transition powder is applied to the seed. wetting agentPrior to application, the liquid wetting agent is heated and maintained around 55 C. By heating the wetting agent the viscosity of the liquid is lowered which improves seed coatability, minimizes clumping, and decreases the formation of “dead balls” (i.e. pellets formed during the coating process that do not contain seed). Amount of wetting agent seed coating will depend on the severity of soil water repellency within the soil.
[0108] Powder used to coat soil wetting agent onto the seed is the same as that used in the transition powder, previously explained above. Due to the tackiness of the soil wetting agent, adhesive binders are not required in this part of the coating process. During the coating process it is important that moisture of the seed coat be maintained at optimal rates; if the seed coating becomes too saturated with wetting agent, seeds will begin to clump together and or the seed coating will fall off of the seed. If denser coated seeds are desired the ratio of lime or other powder to oil absorbent can be increased. The density of the seed coating is increased because; 1) more powder is required to absorb the same amount of soil wetting agent, and 2) increased use of powders such as lime that are significantly denser than oil absorbent will increase coat density.
[0109] While not necessary to the invention, upon completion of the pellet a film coat can be added to enhance pellet structure and minimize “dusting off” issues through the loss of coating material during transportation and delivery. After final seed treatment application, the coated seed can be placed on a drying rack, and dried with or without heat.
[0110] Tackifiers
[0111] Mulch tackifiers can also be incorporated into seed coatings to increase seed retention through anchoring the seeds to the soil, and when applied in combination with wetting agents, to further enhance moisture availability and duration. When applied without wetting agent, a slurry of a psyllium tackifier is applied to seed within the coating machine by direct injection onto the atomizing disk while tackifier powder or other carrier (such as powdered limestone) is added on top of the seed to aid in solidification of the coating. To further increase structure of the seed coat, upon addition of the tackifier amendments, the seed is left spinning without addition of amendments for an additional 1.5 min to compact amendments around the seed.
[0112] When applied with wetting agent, psyllium tackifier is applied in powder form on top of the seeds as liquid wetting agent is added as described above. Mixing psyllium tackifier powder with an oil absorbent can increase the ratio of wetting agent to powder where higher rates of wetting agent application are desired. Use of a psyllium tackifier powder in combination with an oil absorbent to apply wetting agent can result in a less dense seed coating than when wetting agent is applied with oil absorbent and other powders (such as powdered limestone). This can be advantageous where end weight of the coated seed may influence its utility, as in aerial seeding efforts.
[0113] Agglomeration
[0114] Seed coating treatments previously explained can also be applied to agglomerations of seeds (i.e. multiple seeds grouped together within the same pellet). Prior to agglomeration a seed protectant is applied as explained previously. To group the seeds together an adhesive is applied to the seed via injection onto the atomizing disk. During the period in which adhesive is applied, powder is withheld, resulting in the grouping of the seeds, with agglomeration size primarily dependent upon adhesive rate and period of time powder is withheld. Once the desired agglomeration size has been reached binder is withheld and a burst of hydrophilic powder (such as limestone) is applied, thus stopping the seeds from further agglomerating, resulting in seed batches containing similarly sized pellets comprised of multiple seeds. Target agglomerate pellet size should depend on application. For example if soil physical crust was limiting seedling emergence, agglomerate pellet size should contain enough seeds to facilitate seedling emergence, but be small enough to facilitate planting. Based off of the research conducted with grass seed, we recommend agglomerates containing around 10 or fewer seeds per pellet. Beyond this rate pellet sizes would be difficult to plant with conventional seeding equipment, or, if aerially seeded, large pellet sizes will result in a significant portion of the seeds being elevated above the soil surface, resulting in decreased moisture resources for those seeds at the top of the pellet.
[0115] Once seeds have been agglomerated together, the desired amendments such as soil wetting agents and tackifiers can be applied by the same processes described previously. If such amendments are not desired, seed weight/coating thickness can be increased around the agglomerates by applying binder and coating powders.
Example 1
Wetting Agent Seed Coating
[0116] The grass species evaluated included bottlebrush squirreltail ( Elymus elymoides (Raf.) Swezey) and crested wheatgrass ( Agropyron cristatum L. Gaertn.). Seeds were coated using a RP14MAN seed coater (BraceWorks Automation and Electric, Lloydminster, SK Canada). Seeds were coated first with a plant protectant, which consisted of 88% weight of seed to weight of product ratio (w/w) crushed limestone (size less than 200 mesh, with the bulk smaller than 300 mesh) attached to the seed with 21% w/w binder consisting of 3 parts water and 1 part polymer 100© (Germains Technology Group (Gilroy, Calif.).
[0117] To aid in the attachment of soil wetting agent, transition powder consisting of a blend containing about 5.1% w/w oil absorbent −325 RVM (Oil-Dri Corporation of America, Alpharetta, Ga.) (or, alternatively, sorbent mineral powders such as montmorillonite, attapulgite or diatomite) and 2.8% w/w powdered limestone, was attached with the above binder at 1.9% w/w for a total of 9.8% w/w increase. Soil wetting agent used was a concentrated nonionic blend comprised of a of alkylpolyglycoside (APG) and ethylene oxide/propylene oxide (EO/PO) block copolymers, developed by Aquatrols Corp. Prior to application, wetting agent was heated and maintained at 55 degrees C. during the coating process. Wetting agent was applied at 240% w/w, through injection onto the rotary coater's atomizer disk. During the application of wetting agent, the same powder mixture applied above in the transition powder was added at 485% w/w, through a powder feeder. After final wetting agent application, the coated seeds were placed on a drying rack, and allowed to air dry over night.
[0118] Soil was collected from the subcanopy of burned juniper trees ( Juniperus osteosperma (Torr.) Little). Average water drop penetration time (WDPT) under the subcanopy of burned P-J trees was 1.36±0.19 hrs. The mean depth to the water repellent zone from the soil surface was 1.40±0.12 cm, with a water repellent layer extending beyond this point 4.80±0.51 cm on average. Coated seeds were evaluated against uncoated seeds (control) that were planted in soil cores (20.32 cm diameter by 25.4 cm deep), with 12 seeds per pot, and 3 replicates per treatment. Because the number of germinable seeds was different between species tested, plant density results are presented after normalizing for germination.
[0119] Results of this study indicate that the invention improved ecohydrologic properties required for seed germination and plant survival. In this study the effect of proposed seed coating invention was explicit, with plant density of bottlebrush squirreltail and crested wheatgrass 343% and 733% higher than the control, respectively (Table 1).
[0000]
TABLE 1
Survival of germinable
Species
Treatment
seeds (%)
E. elymoides
Control
19.4
E. elymoides
240% w/w wetting
85.8
agent
A. cristatum
Control
7.9
A. cristatum
240% w/w wetting
66.1
agent
Example 2
Rate Analysis and Agglomeration Evaluation
[0120] Conglomerate evaluations were performed using crested wheatgrass ( Agropyron cristatum ). Single seed coatings were applied using the same methods previously explained in example 1, with seeds coated with either 96% w/w or 240% w/w wetting agent.
[0121] Agglomerations of seeds were formed after application of the plant protectant. Seeds were grouped together using 22% w/w binder consisting of 1 part water and 1 part polymer 300© (Germains Technology Group (Gilroy, Calif.). During the period adhesive was applied, powder was withheld. After application of binder 20% w/w limestone was rapidly added, thus stopping the seeds from further agglomerating together, resulting in seed batches containing pellets around 3-4 seeds. At this point methods used for applying wetting agent to a single seed were employed for application to the agglomerates.
[0122] Results indicated that seeds coated with 96% w/w wetting agent showed a 348% increase in seedling density over the control. Seeds coated with 240% w/w wetting agent were 33% higher than the seeds treated with 96% w/w wetting agent. Interestingly seeds agglomerated together showed a 75% increase over single seeds, which we attribute to improved plant growth of seedling radical and cotyledons. Treatment of agglomerated seeds with wetting agent showed the greatest increase in seedling survival with a 87% over non-coated single seeds. We speculate that the results between treated seeds and uncoated seeds are not as dramatic as Example 1 because of differences in the length of the study. Data for example 1 shows seedling density 6 weeks after planting, while example 2 is only 2.5 weeks after planting. Based off of previous studies on water repellent soil we speculate that the differences between the wetting agent treated and uncoated seeds will increase.
[0000]
TABLE 2
Survival of germinable seeds (%)
Treatment
single seeds
Agglomerates
control
6.2
24.7
96% w/w wetting agent
27.8
not tested
240% w/w wetting agent
37.0
46.3
Example 3
Mulch Tackifiers and Agglomeration
[0123] Conglomerate evaluations were performed using crested wheatgrass ( Agropyron cristatum ). Agglomerations were formed using 35% w/w polymer 300© (Germains Technology Group (Gilroy, Calif.) at a ratio of 1 part polymer 300 to 1 part water. A psyllium tackifier, Ecology Controls M-Binder (S&S Seeds, Inc. Carpinteria, Calif.) was coated onto seed agglomerations in slurry form consisting of 10.8% w/w Ecology Controls M-Binder powder and 90.2% w/w water. Powdered limestone was added simultaneously with the slurry to provide a surface for the slurry to adhere to and facilitate coating of a greater amount of the tackifier. Approximately 1.83 g of lime was added per gram of slurry (62% w/w slurry, 114% w/w lime).
[0000]
TABLE 3
Survival of germinable
Treatment
seeds (%)
control
27.8
psyllium tackifier
111.1
conglomerate
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The present invention provides innovative methods and techniques for improving seedling germination and plant establishment within wildland and forested ecosystems, cultivated systems, urbanized areas, and areas impacted by wildfire. The invention comprises novel seed coating methods for applying wetting agents (or surfactants), tackifiers, and other beneficial soil and plant amendments, to single seeds or agglomerates composed of pellets containing multiple seeds. The invention can be used to: 1) ameliorate soil water repellency for increasing soil moisture availability; 2) bind seeds to the soil surface in order to prevent loss from wind and water erosion; 3) provide seedlings necessary leverage required for root penetration; 4) improve seedling emergence, by having several cotyledons associated with an agglomerate collectively generate sufficient force to penetrate the soil surface, with particular utility for seedlings impaired by a soil physical crust; and 5) minimize impacts from disturbance by increasing seedling stability.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to radar detection circuits and more particularly to RF pulse detection circuits. The invention can be used to detect interferometric RF signals for high resolution holographic radar, rangefinding radar, motion sensing radar, and reflectometer radar.
2. Description of Related Art
High bandwidth sample-hold circuits can be used to receive radar signals for high resolution imaging, ranging and motion sensing applications. Optimally, the sample aperture is set to match the width of the pulse being sampled. When the RF signal is a short burst of sinusoids, the sample aperture is set to one-half of an RF cycle. Ultra-wideband (UWB) emissions are defined by the FCC as having greater than 500 MHz bandwidth.
A stringent requirement for UWB radar sampling is sample timing must coincide with the expected temporal location of an echo, otherwise the sampler would miss the echo. A timing error corresponding to ½ of an RF cycle could result in no reception. Low timing jitter is also extremely important. Excessive timing jitter in pulse-averaging UWB radar can have significantly reduced sensitivity, while a non-averaging radar can exhibit a significant number of misses. UWB samplers and mixer-integrators (i.e., correlators) are phase and frequency sensitive.
Most UWB radar signals contain multiple RF lobes due to differentiation in the antenna and pulse circuitry, or due to emissions produced by short burst transmit oscillators, generally with bursts of less than 2 ns wide. At least one full RF cycle is almost always involved in UWB reception. If the sampling aperture were set to one full RF cycle, a sampler or a correlator would integrate the RF signal across the sampling aperture and produce zero output. Clearly, it is necessary to sample a half cycle in these UWB applications. In burst mode, successive repetitions of ½ cycle sampling can occur across the burst
When RF sinusoids are sampled using a UWB sampler, the sampled output is mixed-down, aliased or down-converted. In tank-level radar, a 6 GHz RF burst signal is can be down-converted to a 6 kHz expanded time burst signal by the sampler in concert with a stroboscopic timing system. Down-conversion allows signal processing to occur at greatly reduced bandwidth for reduced cost, reduced power consumption and improved accuracy.
In 1993, an averaging UWB sampler was disclosed in U.S. Patent, “Ultra-wideband Receiver,” by Thomas McEwan, the present inventor. A capacitor is connected to an RF input, e.g., an antenna, and to one end of a diode. The other end of the diode is connected to a narrow gate pulse source. The combination of the gate pulse and RF signal produces conduction in the diode and the capacitor is charged in proportion to the RF signal during the gate pulse. By using a large capacitor, a large number of conduction cycles are required to produce a quiescent voltage on the capacitor. A large number of pulses are thereby integrated on the capacitor and UWB detection and down-conversion occurs at the capacitor connected directly to the antenna. This UWB sampler is extremely simple and highly sensitive. It is directed to the reception of wideband and UWB RF signals using narrow aperture gate pulses that are matched to the UWB input signal. Gate pulse width is generally set to ½ of an RF cycle in width. Gate pulse width cannot be set to one RF cycle or to a large number of RF cycles since the integrated, sampled average would be zero, or near zero, due to the fact that a received RF cycle must have a zero average in order to propagate through free space.
While aliasing can be advantageous, limitations occur in systems where timing jitter or RF oscillator phase noise is excessive. In these cases, it would be preferable to have a phase-independent sampler. Aliasing can also be a severe detriment in range-gated interferometric radar, e.g., holographic radar where a reference wave is employed. Undesired aliasing and desired interferometric patterns can be of the same order and thus indistinguishable. A non-aliasing magnitude-only sampler is needed. A range-gated interferometric radar is disclosed in copending U.S. patent application Ser. No. 12/380,324, “Range Gated Holographic Radar,” by the present inventor, Thomas E. McEwan.
SUMMARY OF THE INVENTION
The invention includes a method of sampling the magnitude of an RF signal by producing a unipolar gate pulse at least two RF cycles in duration and coupling the unipolar gate pulse and the RF signal to a diode to produce diode conduction pulses during the unipolar gate pulse duration and during a portion of each RF cycle. At least two conduction pulses are integrated to produce a sample. The unipolar gate pulse can be less than 10 ns in duration to provide high temporal resolution sampling of the narrowband RF signal.
The invention is an RF magnitude sampler based on a diode for providing a conduction element, an RF port coupled to the diode for coupling a narrowband RF signal to the diode, a gate port coupled to the diode for coupling a unipolar gate pulse to the diode, wherein the gate pulse drives the diode into conduction during a portion of at least two RF signal cycles to produce conduction pulses; and an integrating capacitor coupled to the diode for integrating at least two conduction pulses to produce a sample. The invention can also include a bandpass filter coupled to the integrating capacitor for producing an intermediate frequency output responsive to an amplitude modulated narrowband RF signal. The invention can operate with a narrowband RF reference signal and RF radar echoes that form an interferometric pattern at the RF port.
Another embodiment of the invention forms a quadrature RF magnitude sampler that includes a first diode for providing a first conduction element, a second diode for providing a second conduction element, a first RF port coupled to a transmission line and coupled to the first diode for coupling an RF signal to the first diode, a second RF port coupled to a transmission line and coupled to the second diode for coupling the RF signal to the second diode, wherein the second port is physically spaced apart from the first port by a fraction of a wavelength along the transmission line, a gate port coupled to the first and second diodes for coupling a unipolar gate pulse to the diodes, wherein the gate pulse drives the diodes into conduction during the gate pulse duration and during a portion of at least two RF signal cycles to produce conduction pulses in the first and second diodes, a first integrating capacitor coupled to the first diode for integrating at least two conduction pulses and for producing in-phase samples, and a second integrating capacitor coupled to the second diode for integrating at least two conduction pulses and for producing quadrature-phase samples. The transmission line propagates an RF interference pattern formed by a reference wave and radar echoes.
Objects of the present invention are: (1) to provide a simple and low-cost gated, linear RF magnitude detector; (2) to provide a phase-independent gated RF detector; and (3) to provide an RF sampler that does not exhibit aliasing, down-converting or mixing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a sampler of the present invention.
FIG. 2 is a schematic diagram of the sampler.
FIG. 3 a is a waveform diagram of the sampler with an RF signal.
FIG. 3 b is a waveform diagram of the sampler with an interferometric RF signal.
FIG. 4 is a block diagram of the sampler with an IF output.
FIG. 5 is a block diagram of a quadrature configuration of the sampler.
DETAILED DESCRIPTION OF THE INVENTION
A detailed description of the present invention is provided below with reference to the figures. While illustrative component values and circuit parameters are given, other embodiments can be constructed with other component values and circuit parameters.
General Description
The present invention overcomes the limitations of the various prior sampling receivers by employing a gated peak detector to produce phase-independent magnitude samples of an RF signal. The sampler operates by peak detecting RF signals with a time-gated peak detector and by integrating the peak detector output to provide an output sample. In one embodiment, an RF signal is summed with a gate pulse and applied to a Schottky diode, where the RF peaks in the combined waveform drive the diode into conduction and produce diode conduction current pulses only during the gate pulse duration. The diode conduction pulses are coupled to a capacitor or lowpass filter and integrated. When the gate pulse spans at least two RF cycles, two RF peaks will always occur within the duration of the gate pulse. Voltage on the capacitor will charge to maximum output within two RF cycles, or within a larger number of cycles depending on design parameters. Once the charge reaches maximum, no further change in sampled output will occur for continuing RF input signals of the same of lower amplitude. The sample amplitude is unaffected by the phase of the RF signal as long as two peaks occur within the gate duration.
Peak detected samples do not depend on the RF signal frequency or phase. Only the amplitude of the RF signal affects the output samples. As a consequence of phase/frequency independence, the sampler does not produce aliased or down-mixed signals. This is of critical importance in radar systems with noisy RF oscillators or timing jitter, and in holographic radars. Unlike prior samplers, the present sampler can sample and integrate across an arbitrary number of RF cycles and produce output samples that are substantially independent of RF phase and frequency. Thus, higher S/N can be achieved in situations where frequency or phase noise is high.
The present invention can exhibit limited sensitivity in certain circumstances, particularly in radars that do not employ a reference RF wave, e.g., in non-holographic radars. Without a reference RF wave, sensitivity can be limited to perhaps −50 dBm, on the order of 1 mV of RF. In this situation, the sampler is best suited for short range radar, perhaps less than several meters range, or for applications which employ preamplifiers. Nonetheless, the extreme simplicity and phase/frequency independence of the sampler makes it well suited to a broad class of short range radar applications.
In prior art sampling-type radars, including rangefinders and range gated Doppler sensors, the temporal jitter between the gate pulse and the echoed microwave sinusoids must often be on the order of 10 ps or less. This is a very stringent requirement, particularly when the gate pulse is delayed 100 ns or more. A delay of 100 ns corresponds to a range gate of 15 meters.
Also in prior art sampling-type radars, the sampling gate pulse is often set to ½ of an RF cycle in width. It cannot be set to one RF cycle since it would average the sample to zero due to the fact that a received RF cycle must have a zero average in order to propagate through free space. In contrast, the gate duration in the present invention can be two full RF cycles or more. It would seem that the present invention reduces spatial resolution compared to prior art samplers. However, most practical radars, such as tank level gauging radars, operate with an RF burst of perhaps 10 cycles or more. This is due to a combination of antenna and hardware bandwidth limitations, and to regulatory (e.g., FCC) limitations. Thus, extending the detection width from ½ to 2-cycles has virtually no effect on spatial resolution of practical radar sensors.
The sensitivity of the sampler is very high when a reference RF signal is combined with echoes to form an interferometric pattern and then input to the sampler. In this case, the reference RF wave can be large, on the order of +10 dBm. Diode threshold and low conduction effects are minimal under this RF condition, and sensitivity can be excellent. This mode is employed in copending U.S. patent application Ser. No. 12/380,324, “Range Gated Holographic Radar,” by the present inventor. In this mode, the sampler produces short aperture, signed-magnitude samples of a holographic interference pattern produced by the addition of reference RF pulses and RF echoes.
In holographic radar, a reference RF signal and echo RF signals in combination can be propagated along a transmission line. Interference patterns form as a distributed pattern along the transmission line. Two samplers of the present invention can be located at taps on the transmission line with a spacing that corresponds to ¼ wavelength to produce quadrature samples. Since the interference pattern is formed by constructive and destructive combinations of the reference and echo RF signals, the combined magnitude can either increase or decrease along the line, relative to the reference pulse alone. The output samples can increase or decrease according to the interference pattern, i.e., signed magnitude samples are produced. The combination of signed magnitude samples and ¼ wavelength spacing produce samples that represent all four phase quadrants. Thus, phase quadrature I and Q samples of the interference pattern can be obtained using magnitude-only samplers of the present invention.
Output samples from the present invention can be passed though a bandpass filter with center frequency below a radar's PRF, where the bandpass filter passes an intermediate frequency IF. Radar transmit pulses can be amplitude modulated at the IF and consequently, samples of echoes will be modulated at the IF. The use of an IF provides benefits associated with classic superheterodyne receiver architectures, such as freedom from power supply and low frequency noise, the ability to use an AGC, and compact, convenient selectivity, noise filtering and amplification.
Two samplers of the present invention can be configured in a differential configuration to reject common gate pulse noise and to allow for balanced RF input without the need for a balun. Well-balanced RF baluns can be very difficult to fabricate and integrate. In the differential sampler configuration, one sampler forms a plus input and a second sampler forms a minus input. The sampler outputs can be summed with one output being inverted prior to summing. A common gate pulse can drive both samplers.
Specific Description
Turning now to the drawings, FIG. 1 is a block diagram of an exemplary high resolution sampler for radar signals, generally 10 . A gated peak detector 12 has an RF port, labeled port 1 , a gate port labeled port 2 and a peak detector output line 14 . Line 14 is connected to lowpass filter 16 . The integrator produces a sample output signal at port 3 . Lowpass filter 16 can also be an integrator. Gate pulses depicted by waveform 40 are applied to the gate port and bias-on the peak detector, causing it to peak detect for the duration of the of the gate pulse, e.g., during the negative portion of gate waveform 40 . Gate waveform 40 can be derived from a radar range gate generator. The gate pulse need not have any particular phase relation to the RF signal applied to port 1 . However, it must be sufficiently wide to include at least two RF input cycles, which would inherently include two lobes having two associated peaks. The peak detector charges to a peak voltage determined in part by the RF signal at port 1 . Gate pulse 40 can be on the order of 1 ns wide, which spans 10 cycles of a 10 GHz RF signal, for example.
Gate pulse 40 is derived from a clock signal or a pulse repetition frequency (PRF) oscillator. The gate pulse is often the result of trigging on an edge of a clock waveform, where the clock could be a transmit or receive timing clock with a fixed or adjustable delay, or a swept delay between them.
In a radar receiver application, the gate pulse need not be tightly phase locked to the RF phase at port 1 , as would be the case in stroboscopic, or down-converting, sampling type radars. This independence from RF phase is due to the fact that peak detector 12 will ideally detect the peak amplitude of the RF signal within two RF cycles, independent of the phase of the RF cycles relative to the gate pulse. It is only necessary that the gate pulse span at least two RF cycle to ensure at the peak detector settles to a maximum within the gate pulse duration.
Gate pulse 40 can span many RF cycles, e.g., an aggregate of 10 or more cycles in a narrowband RF packet or burst, and peak detector 12 can incrementally charge to a peak value across the aggregate, where each increment corresponds to an RF peak. Integration is thereby is performed during the peak detection process and peak detector hardware bandwidth requirements are minimized. As a further enhancement in some applications, peak detector 12 can hold its peak value with a small voltage droop across one or more pulse repetition intervals (PRI) to allow integration across multiple PRI's. Peak detector 12 , in combination with lowpass filter 16 can integrate across a number of PRI's to reduce noise and interference levels.
FIG. 2 is a schematic diagram of an exemplary sampler, generally 10 . Diode 22 performs a peak detection function. It has an anode and cathode, and current (conventional current) primarily flows in one direction, from the anode to the cathode. In many applications, it is a Schottky diode. It can also be a diode formed by a transistor junction or by other diodes known in the art. Capacitor 24 is connected between the diode and gate port 2 . It serves as a peak hold capacitor. Resistor 26 bleeds off the peak-held voltage at a rate determined by the application, and generally it must bleed off charge at a rate that can follow RF signal modulation. Resistor 28 , in combination with capacitor 30 , form a lowpass filter or an integrator. The lowpass filter provides RF isolation between diode 22 and output port 3 ; it blocks RF signals and gate pulses from coupling to output port 3 . A time constant is formed by the product of resistor 28 and capacitor 30 , which can be an integration time constant if set sufficiently large. Alternatively, if the time constant is short, the function of resistor 28 and capacitor 30 is mainly to block microwave frequencies and nanosecond speed gate pulses from appearing at port 3 . Additional integration (i.e., time running averaging), or lowpass filtering, can occur downstream from port 3 .
RF signals that are input to port 1 and gate pulses that are input to port 2 effectively add to the net voltage across diode 22 . Diode 22 is driven into forward conduction when the net voltage exceeds its intrinsic threshold voltage, generally about 0.4V. Gate pulse 40 can have a voltage swing of 3V, while RF input signals are generally on the order of 1-100 mV. The upper level of gate pulse 40 is set to hold diode 22 biased OFF regardless of RF signal amplitude. When the gate pulse swings low, the combined RF and gate voltage bias-ON diode 22 during positive lobes of the RF signal. When the diode is biased-ON, diode conduction current pulses flow from the anode to the cathode of the diode. The diode conduction pulses flow into capacitor 24 and charge it to a maximum voltage that corresponds to the sum of the RF positive lobe peaks and the gate pulse. Substantial DC offsets exist due to the diode threshold and the gate pulse voltage. When no RF is present, capacitor 24 charges to a quiescent voltage due to repetitive gate pulses. RF signals produce incremental changes from the quiescent voltage on capacitor 24 . Generally, DC offsets are of little concern since the sampled output at port 3 is generally amplified by an AC coupled amplifier or a bandpass filter. The location of diode 22 can be interchanged with capacitor 24 and resistor 26 with no change in operation, in principle. Diode 22 can be reversed, with a corresponding inversion of gate pulse 40 .
FIG. 3 a is a waveform diagram of an exemplary sampler. An RF burst 42 is shown in the upper trace. One burst consists of about 15 cycles in this example; often it can consist of hundreds of cycles. Each individual RF cycle has a positive and negative peak. The present invention detects such peaks, often of one polarity only. Balanced, two polarity detectors can be configured by reversing the polarity of the diode and gate pulse in a second detector.
Dashed zig-zag line 44 denotes a cut-out portion of the trace. Line 44 was added for clarity of explanation; without line 44 the line connecting burst 42 to burst 46 could be very long. Burst 46 is a repetition of burst 42 . The occurrence interval between the starts of burst 42 and burst 46 is the pulse repetition interval or PRI. The PRI can be staggered or otherwise modulated.
The lower waveform in FIG. 3 a shows a solid trace labeled “cathode” and a dashed trace labeled “output.” The cathode trace represents the voltage at the cathode of diode 22 . It consists of gate pulse 40 that is coupled to the cathode, and positive RF signal peaks 52 and 56 from bursts 42 and 46 that couple from the anode to the cathode via diode conduction. Conduction occurs on at least a portion of the RF cycles that occur within the gate pulse duration, as indicated by the output trace.
The dashed trace is the voltage measured across peak hold capacitor 24 . This is a differential voltage, i.e., the difference between the two plates of the capacitor. Gate pulse 40 appears on both plates equally and does not affect the exemplary differential trace. Diode conduction current pulses charge capacitor 24 . Incremental charge voltages ΔV 1 and ΔV 2 indicate small increments in the capacitor voltage as a result of peak conduction pulses associated with peak voltages 52 and 56 .
Voltage on capacitor 24 is coupled to output port 3 via a lowpass filter, e.g., resistor 28 and capacitor 30 . This filter blocks pulses 52 and 56 from appearing at the output port. Resistor 28 allows for RF and gate pulse voltage swings at the cathode without introducing a shunting effect by capacitor 30 or by a load at port 3 . Voltages appearing at the output port can be smoothed versions of ΔV 1 and ΔV 2 . Either or both capacitors 24 and 30 can be sufficiently large as to integrate individual pulses 52 , 56 across two or more PRI's. The amount of integration is a design choice.
FIG. 3 b depicts the further inclusion of echo pulses 62 , 66 . Depending on the exact phase of the echoes, they could add or subtract from RF bursts 42 , 46 . As shown, the echoes in this example add to form bursts 72 , 76 . Bursts 72 , 76 are interferometric RF signals. Echo 66 is shown to be larger than echo 62 for illustrative purposes. Both echoes can be from the same target but the transmit amplitude can be modulated for the purpose of producing a modulated detected voltage, as seen by the differences ΔV 1 and ΔV 2 amplitudes in FIG. 3 b.
FIG. 4 depicts sampler 10 additionally including a bandpass filter 82 . Radar transmitters can amplitude modulate transmit RF pulses with each successive PRI or group of PRI's, to produce amplitude modulation of detected voltages ΔV 1 and ΔV 2 . The modulation frequency must be lower than the inverse of the PRI, i.e., lower than the radar PRF. This frequency can be an intermediate frequency designated IF. Accordingly, bandpass filter 82 can be an IF filter and may include amplification. IF output from filter 82 can be coupled on line 84 to a mixer 86 . Element 86 can also be analog switches or gates and may form a synchronous demodulation when switched, or mixed, with an IF local oscillator signal (IF LO). Element 86 can also be a simple diode-capacitor without an IF LO to simply envelop detect the IF signal on line 84 . A lowpass filter 88 can be included to remove IF components and to pass detected baseband signals from element 86 , and to provide a sample output signal at port 3 . A dashed line and another port 3 are shown to indicate that sampler 10 can output both IF and “direct output” signals simultaneously for various radar purposes.
FIG. 5 shows a quadrature version of exemplary sampler 10 . A transmission line 122 propagates transmit radar pulses from end 124 to end 126 for transmission via an antenna or TDR line. Echoes return to line end 126 . Transmit pulses are narrowband RF bursts such as bursts 42 , 46 of FIG. 3 a and are of sufficient duration as to extend beyond the time of occurrence of echoes. Echoes vector-sum with the transmit bursts to form interferometric patterns along line 122 , similar to pulses 72 , 76 of FIG. 3 b . Two samplers 10 are coupled to taps at locations 128 , 130 . In this example, the samplers are gated by a common gate pulse applied to port 2 ; separate gate pulses can be applied for various purposes. Examples of transmission line 122 can include a microstrip, a coax, a waveguide or a lumped element structure. A quadrature network or various microwave phase splitters can be employed. In the event that line 122 is a waveguide, the taps can be waveguide current or voltage probes or ¼ wave monopole antennas inside the waveguide.
If taps 128 , 130 , i.e., coupling points, are spaced apart by ⅛ wavelength of the RF frequency, magnitude samples will be taken that represent in-phase I and quadrature phase Q components of the echoes. It is as though samples were taken ¼ wave apart by conventional phase-sensitive mixers. It should be noted that ⅛ wave spacing is used to achieve ¼ wave sampling due to 2-way travel on the line.
Magnitude samples of interferometric patterns produce signed magnitude samples, since echoes 62 , 66 can have a phases that either add or subtract from transmit bursts 42 , 46 . In holographic terms, bursts 42 , 46 are repetitive reference waves. The combination of signed magnitude samples and ⅛ wave taps produce output samples at ports labeled I and Q that fully represent the RF interference pattern in all four phase quadrants.
An RF signal is considered to include one or more cycles, each cycle having a positive and negative lobe, and each lobe having a peak. The use of the term “narrowband” herein refers to RF signals with a bandwidth that can fit in designated regulatory frequency bands, such as the ISM bands and other bands that are generally regarded as narrow plots of spectrum. Further, it can refer to amplitude modulated ON-OFF RF pulses with a number N of RF cycles in a burst, where N=2 and often 10 or greater. Since ultra-wideband signals have greater than 500 MHz bandwidth, narrow-band can be defined as having less than 500 MHz bandwidth. One example of a narrowband radar RF signal is a 1 MHz squarewave modulated 10.525 GHz RF carrier. Measurements indicate that such a carrier has less than 40 MHz occupied bandwidth (OBW, containing 99% of total power). Pulse holographic radar developed by the present inventor can exhibit spatial resolution normally associated with radar having 100 times more bandwidth.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.
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A gated peak detector produces phase-independent, magnitude-only samples of an RF signal. Gate duration can span as few as two RF cycles or thousands of RF cycles. Response is linearly proportional to RF amplitude while being independent of RF phase and frequency. A quadrature implementation is disclosed. The RF magnitude sampler can finely resolve interferometric patterns produced by narrowband holographic pulse radar.
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BACKGROUND OF THE INVENTION
Most of the commercially available exercisers for jogging are of resistance-driven type, that is, a user must heavily tread a conveyor of the exerciser on tiptop to drive the same to move. Then, the user has to increase the exerciser's momentum by accelerating the movement of his or her tiptoes and thereby gets his or her legs exercised. Following disadvantages are found in the conventional jogger exercises:
1. The conventional jogger exercisers are usually unfoldable in their structure and therefore occupy considerably large room that adversely affects the convenient storage and transport of the exercisers.
2. To use the resistance-driven jogger exerciser, the user must drive the exerciser to move by heavily treading on tiptoe on the conveyor of the exerciser and must tread the conveyor at an increasing speed to keep the exerciser moving. This is obviously an energy-consuming operation not easily performed by those younger or older users.
3. The conventional jogger exerciser is designed for training the muscles of legs and can not be used to get the whole body exercised.
4. Only the legs are moving when using such conventional jogger exerciser. The movement of treading is monotonous without enjoyment.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a jogger exerciser which may get the user's whole body exercised.
Another object of the present invention is to provide a knockdown type jogger exerciser which is foldable and can be disassembled when necessary to reduce the space it occupies for convenient storage and transport.
A further object of the present invention is to provide a jogger exerciser which can be operated in an alternately swinging manner to provide more enjoyment.
To achieve the above objects, the jogger exerciser of the present invention mainly includes two swing members rotatably associated with two support frames and a hand grip detachably connected to a top portion of the support frames. To use the jogger exerciser, firmly hold the hand grip, stably stand on the two swing members, and then relaxedly stretch the whole body and alternately swing the swing members with feets back and forth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an assembled perspective of the jogger exerciser according to the present invention;
FIG. 2 is a fragmentary, enlarged, disassembled perspective of the jogger exerciser;
FIG. 3 is a fragmentary, enlarged, disassembled perspective showing the structure of the lower portion of the swing member;
FIG. 4 illustrates the jogger exerciser of the present invention with the swing members in a initial position;
FIG. 5 illustrates the jogger exerciser of the present invention with the swing members in a widely swung position; and
FIG. 6 illustrates the jogger exerciser of the present invention in a folded state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Please refer to FIGS. 1 and 2. The present invention relates to a jogger exerciser which mainly includes a first support frame 1, a second support frame 2, a hand grip 3, a first swing member 4, a second swing member 5, and unions 6.
The first support frame 1 is a U-shaped frame formed from a hollow pipe. A transverse lower portion of the first support frame 1 is directly disposed on the ground or the floor as a base. Two upward extended vertical portions of the frame 1 space from each other at a top part at a distance smaller than that at a bottom part thereof. As shown in FIG. 2, each vertical portion of the frame 1 is provided near a top end with a pair of first holes 11 and a pair of second holes 11A below the first holes 11, near a middle outside with a third hole 118, and at a position slightly lower than the top end with a first knuckle member 13 having a first transversely extended central hole 14.
The second support frame 2 is also a U-shaped frame formed from a hollow pipe similar to the first support frame 1. A transverse lower portion of the second support frame 2 is directly disposed on the ground or the floor as a base. Two upward extended vertical portions of the frame 2 space from each other at a top part at a distance smaller than that at a bottom part thereof. As shown in FIG. 2, each vertical portion of the frame 2 is provided at a top end with a connecting head 22 having a third transversely extended central hole 221, at a position slightly lower than the connecting head 22 with a second knuckle member 31 having a second transversely extended central hole 311, and near a middle outside with a fourth hole 21.
The union 6 is a substantially U-shaped member having two substantially triangular side walls parallelly extended from two sides of a rounded middle connecting part to contain a space 64 between them. The space 64 is large enough to fitly clamp the hand grip 3 when the same is connected to the frame 1 and to fitly clamp the connecting head 22 of the frame 2. Three pairs of fifth, sixth, and seventh holes 61, 62, 63 are formed on two side walls of the union 6 at an upper, a lower, and a pointed middle parts thereof, respectively.
The first swing member 4 includes a first tread 40, a first link 401 connected to a first end of the first tread 40, and a second link 402 connected to a second end of the first tread 40. The first tread 40 is formed at two longitudinal sides near the first end with a first pair of bottom curved notches 403, at two longitudinal sides near the second end with a second pair of bottom curved notches, at a top surface near the first end just above and between the first pair of notches 403 with an eighth pair of holes 404, 405, and at the top surface near the second end just above and between the second pair of curved notches with a first pair of holding members 406. The first link 401 is formed at a top end with a first inserting stem portion 4011, an outer part of the first inserting stem portion 4011 is formed with a fourth central hole (not shown). As shwon in FIG. 3, the first link 401 is further formed at a bottom end with a first sleeve portion. The second link 402 has a structure similar to that of the first link 401 and is formed at a top end thereof with a second inserting stem portion 4021, an outer part of the second inserting stem portion 4021 is formed with a fifth central hole (not shown). The second link 402 is further formed at a bottom end with a second sleeve portion 4023 (as shown in FIG. 6).
The second swing member 5 is a counterpart of the first swing member 4 and therefore has a second tread 50, a third link 501 connected to a first end of the second tread 50, and a fourth link 502 connected to a second end of the second tread 50. The second tread 50 is formed at two longitudinal sides near the first end with a third pair of bottom curved notches (not shown), at two longitudinal sides near the second end with a fourth pair of bottom curved notches, at a top surface near the first end just above and between the third pair of notches with an pair of eleventh holes (not shown), and at the top surface near the second end just above and between the fourth pair of curved notches with a second pair of holding members 406, as can be seen from FIG. 6. The third link 501 is formed at a top end with a third inserting stem portion 5011, an outer part of the third inserting stem portion 5011 is formed with a sixth central hole (not shown). The third link 501 is further formed at a bottom end with a third sleeve portion (not shown). The fourth link 502 has a structure similar to that of the third link 501 and is formed at a top end thereof with a fourth inserting stem portion 5021, an outer part of the fourth inserting stem portion 5021 is formed with a seventh central hole (not shown). The fourth link 502 is further formed at a bottom end with a fourth sleeve portion 5023 (as shown in FIG. 6).
Two struts 7 are separately extended and interconnected between the third and the fourth holes 118, 21 respectively on the vertical portions of the first and the second frames 1, 2 so as to firmly connect and keep the frames 1, 2 in a widely and stably extended position as shown in FIG. 1.
The hand grip 3 is a reverse U-shaped hollow pipe having a top transverse portion and two downward extended vertical portions. The vertical portions bend slightly at a lower part thereof and each is formed near the lower part with a pair of ninth holes 11B and a pair of tenth holes 11C below the ninth holes 11B. The hand grip 3 has an inner diameter just big enough for the lower part of its vertical portions to mount around an outside diameter of the top part of the vertical portion of the frame 1.
A first screw 12 is used to thread through the respective pairs of fifth, ninth, and first holes 61, 11B, 11, and a second screw 12 is used to thread through the respective pairs of sixth, tenth, and second holes 62, 11C, 11A on the union 6 and each vertical portion of the hand grip 3 and the frame 1, so as to firmly connect the hand grip 3 with the frame 1 with the help of the union 6. A third screw 210 is used to thread through the pair of seventh holes 63 of each union 6 and the third central hole 221 of the connecting head 22 of each vertical portion of the frame 2 clamped in the space 64 between the two side walls of the union 6, so as to indirectly and firmly connect the frame 2 to the frame 1 and the hand grip 3 via the unions 6 to form a stable support stand of the jogger exerciser.
A fourth screw 15 is used to sequentially thread through washers 18, 17, each knuckle 13 on the vertical portions of the frame 1, another washer 16, and into the fourth or the sixth central holes on the first or the third inserting stem 4011 or 5011 of the first link 401 or the third link 501, respectively, to pivotally connect the first and the third links 401, 501 to the first support frame 1.
A fifth screw 150 is used to sequentially thread through washers 180, 170, each knuckle 31 on the vertical portions of the frame 2, another washer 160, and into the fifth or the seventh central holes on the second or the fourth inserting stem 4021 or 5021 of the second link 402 or the fourth link 502, respectively, to pivotally connect the second and the fourth links 402, 502 to the second support frame 2.
Please refer to FIG. 3. The first sleeve portion 4013 of the first link 401 of the first swing member 4 has a long stem screw 195 connected thereto for a sleeve 191, washers 193, 192 and a first nut 194 to sequentially mount therearound, so as to form a sleeve assembly for extending through the first pair of curved notches 403 beneath the first tread 40. Sixth screws are used to thread through the pair of eighth holes 404, 405 and into two threaded holes 1911 on the sleeve 191 so as to fix the first tread 40 to the first link 401 of the first swing member 4.
Similarly, the third sleeve portion of the third link 501 of the second swing member 5 also has a long stem screw 195 connected thereto for a sleeve 191, washers 193, 192 and a first nut 194 to sequentially mount therearound, so as to form a sleeve assembly for extending through the third pair of curved notches beneath the second tread 50. Sixth screws are used to thread through the pair of eleventh holes on the second tread 50 and into two threaded holes 1911 on the sleeve 191 so as to fix the second tread 50 to the third link 501 of the second swing member 5.
The second sleeve portion 4023 and the fourth sleeve portion 5023 also have a long stem screw 195 connected thereto and a second nut 196 mounted around the long stem screw 195, so that the long stem screws 195 may be threaded into the second and the fourth pairs of notches to engage with the first and the second pairs of holding members 406 and be fixedly lock thereto by means of the second nuts 196, and thereby firmly fix the first and the second treads 40, 50 to the second and the fourth link 402, 502, of the swing members 4, 5, respectively.
To use the jogger exerciser of the present invention, simply stand on the first and the second treads 40, 50 and firmly hold the hand grip 3. Then, exert a minor force to move two feet in different directions so that the first and the second swing members 4, 5 are alternately swung back and forth as shown in FIG. 4. When a heavier force is exerted by the user on the first and the second treads 40, 50, the first and the second swing members 4, 5 shall be swung to a larger span, as shown in FIG. 5, which causes the user to exert force with the whole body. The jogger exerciser of the present invention can be operated in a safe and exciting manner while the whole body of the user can be exercised.
Moreover, the jogger exerciser of the present invention is of a knockdown type and can therefore be disassembled or collapsed or folded at any time to a position as shown in FIG. 6 with reduced volume, occupying less space and to be conveniently stored or transported.
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Disclosed is a jogger exerciser which can be folded to a collapsed position to occupy a minimum space for convenient storage and transport. The jogger exerciser can be safely and easily operated by all ages to provide whole body exercise in a relaxed manner while enjoy exciting swing movements.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention generally relates to image processing, and particularly to a method and an apparatus for image compression and decompression.
[0003] 2. Description of Related Art
[0004] Various kinds of image formats such as bitmap (BMP), joint photographic experts group (JPEG), graphics interchange format (GIF), and so on are used for representing images. Particularly, the bitmap is a widely used image format that is generally represented with a two dimensional array of pixels. The bitmap is characterized by a number of bits per pixel (a color depth, which determines the number of colors it can represent).
[0005] Generally, each pixel of the bitmap has three individually defined color data: red, green, and blue. The amount of color information in each pixel determines the quality of the bitmap. Typically, each pixel of an uncompressed bitmap stores forty-eight bits digital data (sixteen bits corresponding to each color data) or twenty-four bits digital data (eight bits corresponding to each color data). A picture quality of the bitmap with forty-eight bits digital data is smoother than that with twenty-four bits digital data.
[0006] High-quality bitmap often takes up large amount of disk space, so some image compressing techniques sacrifice image quality to achieve a smaller file size. For example, one image compressing technique always drops lower three data bits of each color data that may be defined by eight bits, thereby a pixel is compressed from twenty-four bits to fifteen bits. However, this image compressing technique does not consider the color intensity factor of the bitmap during compressing. When the color intensity of the bitmap is relative low, the image quality may deteriorate and digital data for representing the color intensity of each pixel are mainly stored in the lower bits. If the lower data bits are dropped for compression, the image is greatly distorted after decompression.
[0007] Therefore, what is desired is to provide a method that is capable of compressing and decompressing images such as bitmap images considering color intensity factor and an apparatus for image compression and decompression is also desired.
SUMMARY
[0008] Accordingly, a method for compressing image is provided. During compressing, color intensity factor of the image is considered. When the image has a higher intensity, lower data bits of each color data are dropped. When the image has a lower intensity, upper data bits of each color data are dropped. Therefore, the images with different intensities are compressed dynamically. Correspondingly, a method for decompressing image is provided. Moreover, a compressing apparatus and a decompressing apparatus are also provided.
[0009] Other advantages and novel features of the present invention will become more apparent from the following detailed description of exemplary embodiment when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a functional block diagram of a compressing apparatus for compressing image according to an exemplary embodiment.
[0011] FIG. 2 is a detailed diagram of the image compressing apparatus of FIG. 1 .
[0012] FIG. 3 is a flowchart of image compressing.
[0013] FIG. 4 is a functional block diagram of a decompressing apparatus for decompressing image according to an exemplary embodiment.
[0014] FIG. 5 is a detailed diagram of the image compressing apparatus of FIG. 3 .
[0015] FIG. 6 is a flowchart of image decompressing.
DETAILED DESCRIPTION
[0016] Referring to FIG. 1 , a functional block diagram of a compressing apparatus 20 in accordance with an exemplary embodiment is illustrated. The compressing apparatus 20 is used for dynamically compressing digital images such as a bitmap image based on color intensity of the bitmap image. The compressing apparatus 20 includes a data buffer module 21 , a control module 23 , a bit selecting module 25 , and a formatting module 27 . It should be noted that the compressing apparatus 20 may further include other functional blocks such as a display module for displaying images and a storage module for storing compressed image files.
[0017] The data buffer module 21 is configured to couple to data image generating devices, for example, charge coupled device (CCD) image sensors, for receiving and storing temporarily pixel data.
[0018] The control module 23 is connected to the data buffer module 21 , the bit selecting module 25 , and the formatting module 27 . The control module 23 is configured for analyzing color intensity of the pixel data and outputting a data line select signal corresponding to the analyzed color intensity to the bit selecting module 25 . The data line select signal reflects the color intensity that should be reserved in compressed image data for decompressing, so that the data line select signal is outputted to the formatting module 27 .
[0019] The bit selecting module 25 is connected to the data buffer module 21 , the control module 23 , and the formatting module 27 . The bit selecting module 25 is configured for selectively obtaining data bits of the pixel data transmitted from the data buffer module 21 according to the data line select signal transmitted from the control module 23 . If the color intensity of a particular pixel is higher than a predetermined value, upper data bits of the particular pixel are selected, whereas lower data bits of the particular pixel are dropped by the bit selecting module 25 . If the color intensity of the particular pixel is lower than the predetermined value, lower data bits of the particular pixel are selected, whereas upper data bits of the particular pixel are dropped by the bit selecting module 25 . As a result, the pixel data are compressed according to the color intensity.
[0020] The formatting module 27 is connected to the control module 23 and the bit selecting module 25 . The formatting module 27 is configured for receiving selected data bits transmitted from the bit selecting module 25 , and data line select signal from the control module 23 . The data line select signal and the selected data bits are combined by the formatting module 27 to yield formatted pixel data.
[0021] Referring to FIG. 2 , a detailed diagram of the compressing apparatus 20 of FIG. 1 is illustrated. A particular pixel includes three color data: red color data, green color data, and blue color data. Each of the color data are represented with eight bits, thus each of the particular pixel is represented with twenty-four bits totally.
[0022] The data buffer module 21 is connected to the control module 23 and the bit selecting module 25 by a data bus 12 . For exemplary purpose, the data bus 12 includes labeled data lines 10 ˜ 17 , 20 ˜ 27 , and 30 ˜ 37 to more clearly describe the embodiment.
[0023] The data buffer module 21 receives pixel data inputted from input line 11 . The pixel data include eight bits of the red color data, eight bits of the green color data, and eight bits of the blue color data. The eight bits of the red color data are transmitted to the data lines 10 ˜ 17 . The eight bits of the green color data are transmitted to the data lines 20 ˜ 27 . The eight bits of the blue color data are transmitted to the data lines 30 ˜ 37 .
[0024] The control module 23 is connected to the data lines 15 ˜ 17 , the data lines 25 ˜ 27 , and the data lines 35 ˜ 37 . The control module 23 includes an OR gate logic circuit for receiving the upper three bits of the red color data, the green color data, and the blue color data. The control module 23 outputs a logical “0” as the data line select signal if all the bits received are logical “0”, otherwise, the control module 23 outputs a logical “1” as the data line select signal. A Logical “1” outputted from the control module 23 as the data line select signal indicates that the color intensity of the particular pixel is relatively high. Conversely, a Logical “0” outputted from the control module 23 indicates that the color intensity of the particular pixel is relatively low.
[0025] The bit selecting module 25 includes a first input port 252 , a second input port 254 , and an output port 256 . The first input port 252 is connected to the data lines 10 ˜ 14 , the data lines 20 ˜ 24 , and the data lines 30 ˜ 34 of the data bus 12 . The second input port 254 is connected to the data lines 13 ˜ 17 , the data lines 23 ˜ 27 , and the data lines 33 ˜ 37 of the data bus 12 .
[0026] The bit selecting module 25 is configured for selectively receiving data bits from the first input port 252 or the second input port 254 according to the data line select signal. When the data line select signal is logical “0”, the first input port 252 is enabled to receive data bits from the data lines 10 ˜ 14 , the data lines 20 ˜ 24 , and the data lines 30 ˜ 34 . When the data line select signal is logical “1”, the second input port 254 is enabled to receive data bits from the data lines 13 ˜ 17 , the data lines 23 ˜ 27 , and the data lines 33 ˜ 37 .
[0027] The formatting module 27 is connected to the control module 23 and the output port 256 of the bit selecting module 25 . The formatting module 27 is configured for receiving data line select signal of logical “0” or “1” outputted from the control module 23 and the selected data bits either from the first input port 252 or from the second input port 254 . The formatting module 27 combines the selected data bits with the data line select signal, and yields formatted pixel data. The formatted pixel data is outputted from output line 13 . A data size of a particular formatted pixel is sixteen bits, that is, the particular pixel is compressed from twenty-four bits to sixteen bits.
[0028] As described above, the pixel data inputted from the line 11 are compressed in view of color intensity of the bitmap image. When the color intensity of the pixel data is relatively high, several lower bits of a particular pixel are dropped from each color data. When the color intensity of the particular pixel is relatively low, several upper bits of the particular pixel are dropped from each color data. Therefore, a dynamic compression to the bitmap image considering the color intensity of the bitmap is achieved.
[0029] Referring to FIG. 3 , a method 700 for compressing bitmap image in accordance with an exemplary embodiment is illustrated. In some embodiments, the method 700 , or portions thereof, may be performed by the compressing apparatus 20 as described above. The various actions in the method 700 may be performed in the order presented, or may be performed in a different order. Further, in some embodiments, some actions listed in FIG. 3 may be omitted from the method 700 .
[0030] At block 701 , receiving pixel data is performed. The pixel data includes individual color data: red color data, green color data, and blue color data. Each color data is represented with eight bits, and one pixel is represented with twenty-four bits totally. The received pixel data may be temporarily stored in a data buffer module 21 of the compressing apparatus 20 .
[0031] At block 703 , analyzing color intensity of the pixel data and outputting data line select signals corresponding to the color intensity are performed. For example, the control module 23 outputs a logical “0” as the data line select signal if all the bits received are logical “0”, otherwise, the control module 23 outputs a logical “1” as the data line select signal. Logical “1” indicates the color intensity is relatively high. Logical “0” indicates the color intensity is relatively low.
[0032] At block 705 , identifying the data line select signal is performed. For example, the bit selecting module 25 of the compressing apparatus 20 identifies if the data line select signal is logical “0” or logical “1”.
[0033] At block 707 , upon determination that the data line select signal is logical “0”, selecting several lower bits of each color data of the particular pixel is performed. For example, if the data line select signal is logical “0”, the bit selecting module 25 selects and receives lower five bits ( 0 ˜ 4 ) of each color data from the data buffer module 21 .
[0034] At block 709 , upon determination that the data line select signal is logical “1”, selecting upper bits of each color data of the particular pixel is performed. For example, if the data line select signal is logical “1”, the bit selecting module 25 selects and receives upper five bits ( 3 ˜ 7 ) of each color data from the data buffer module 21 .
[0035] At block 711 , formatting the data line select signal and the selected data bits is performed. For example, the data line select signal is combined with five bits red color data, five bits green color data, and five bits blue color data, thereby yielding formatted pixel data. Therefore, the formatted pixel data is represented with sixteen bits.
[0036] As described above, the method 700 for image compression is performed by compressing the pixel data from twenty-four bits to sixteen bits. As color intensity of the image is considered during compression, so the method for compressing bitmap image is dynamic.
[0037] Referring to FIG. 4 , a decompressing apparatus 30 for decompressing a compressed image in accordance with an exemplary embodiment is illustrated. The decompressing apparatus 30 is used for decompressing the compressed image considering color intensity of the compressed image. The decompressing apparatus 30 includes a data buffer module 31 , a control module 33 , and a restoring module 35 .
[0038] The data buffer module 31 is connected to the control module 33 and the restoring module 35 . The data buffer module 31 is configured for receiving compressed pixel data. The compressed pixel data may be from a file stored in a storage medium such as an optical disc. The compressed image includes data line select signal and compressed pixel data. The data line select signal is used for indicating color intensity of the compressed pixel data. The compressed pixel data are used for constructing an image with the data line select signal.
[0039] The control module 33 is connected to the data buffer module 31 and the restoring module 35 . The control module 33 is configured for receiving the data line select signal transmitted from the data buffer module 31 , and outputting the data line select signal to the restoring module 35 .
[0040] The restoring module 35 is connected to the data buffer module 31 and the control module 33 . The restoring module 35 is configured for receiving the data line select signal from the control module 33 , and decompressing the compressed pixel data based on the data line select signal. If the data line select signal indicates that the color intensity of the compressed pixel data is relatively high, the restoring module 35 inserts several “0” bits to lower bits of each color data of the compressed pixel data. If the data line select signal indicates that the intensity of the compressed pixel data is relatively low, the restoring module 35 inserts several “0” bits to upper bits of each color data of the compressed pixel data.
[0041] Referring to FIG. 5 , a detailed diagram of the decompressing apparatus 30 in accordance with an exemplary embodiment is illustrated.
[0042] The data buffer module 31 receives compressed pixel data from line 15 . The compressed pixel data is represented with sixteen bits stored in the data buffer module 31 . Each color data of the compressed pixel data are represented with 5 bits. One flag bit “F” is used for indicating the color intensity of the compressed pixel data.
[0043] The control module 33 retrieves the flag bit “F” from the data buffer module 31 . If the flag bit “F” is logical “1”, the color intensity of the compressed pixel data is relatively high. If the flag bit “F” is logical “0”, the color intensity of the compressed pixel data is relatively low. The control module 33 outputs data line select signal corresponding to the color intensity to the restoring module 35 for decompressing the compressed pixel data.
[0044] The restoring module 35 is connected to the data buffer module 31 by a data bus 32 . The data bus 32 includes, and labeled data lines 10 ˜ 14 , 20 ˜ 24 , and 30 ˜ 34 . The restoring module 35 receives compressed red color data, green color data, and blue color data from data lines 10 ˜ 14 , 20 ˜ 24 , and 30 ˜ 34 respectively.
[0045] The restoring module 35 receives data line select signal corresponding to the color intensity of the compressed pixel data. If the data line select signal is logical “1”, the restoring module 35 inserts three bits “0” after 5 bits red color data “RRRRRR”, 5 bits green color data “GGGGG”, and 5 bits blue color data “BBBBB”. If the data line select signal is logical “0”, the restoring module 35 inserts three bits “0” before the 5 bits red color data “RRRRRR”, the 5 bits green color data “GGGGG”, and the 5 bits blue color data “BBBBB”. The restoring module 35 then outputs decompressed pixel data that is represented with twenty-four bits. Therefore, an image can be constructed by the decompressed pixel data.
[0046] Referring to FIG. 6 , a method 800 for image decompression in accordance with an exemplary embodiment is illustrated. In some embodiments, the method 800 , or portions thereof, may be performed by the decompressing apparatus 30 illustrated in FIG. 4 and FIG. 5 . The various actions in the method 800 may be performed in the order presented, or may be performed in a different order. Further, in some embodiments, some actions listed in FIG. 6 may be omitted from the method 800 .
[0047] At block 801 , receiving compressed pixel data is performed.
[0048] At block 803 , identifying color intensity from data line select signal contained in the compressed pixel data is performed.
[0049] At block 805 , upon determination that the color intensity is identified to be relatively high, inserting several “0” bits after each color data is performed.
[0050] At block 807 , upon determination that the color intensity is identified to be relatively low, inserting several “0” bits before each color data is performed.
[0051] As described above, the decompressing apparatus 30 and the decompressing method 800 are used for decompressing from sixteen bits to twenty-four bits in view of color intensity of the compressed pixel data. When the color intensity of the compressed pixel data is relatively high, several “0” bits are inserted after each color data. When the color intensity of the compressed pixel data is relatively low, several “0” bits are inserted before each color data. Therefore, a dynamic image decompression process is achieved.
[0052] Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope.
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A method of image compressing is provided. During compressing, color intensity of the image is considered. When the color intensity of the image is relatively high, lower bits used for representing the image are dropped. When the color intensity of the image is relatively low, upper bits used for representing the image are dropped. By this, the image is compressed according to color intensity of the image. Therefore, the images with different color intensities are compressed dynamically. Correspondingly, a method of image decompressing is provided. Moreover, a compressing apparatus and a decompressing apparatus are also provided.
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BACKGROUND OF THE INVENTION
[0001] Most cars and trucks have the passenger side rear view mirror mounted directly on the passenger door. On certain types of vehicles, such as, but not limited to the Chrysler Jeep®, (Chrysler and Jeep are a registered trademarks of the Chrysler Corporation, Detroit Mich.), the doors may be removable completely, or have a clear plastic element zippered thereto. Certain classes of vehicles, mostly classified as off-road or expeditionary, such as the Land Rover® or Range Rover® (Land Rover and Range Rover are registered trademarks of LandRover located in the United Kingdom) may also have a removable passenger side door. Japanese or Korean made vehicles may also have a removable side door capability. Certain military vehicles, such as the American/NATO Humvee, (Humvee is a registered trademark of AM General located in Indianna) as well as Russian/Eastern Block or Chinese Communist military vehicles may also have a passenger door removal capability. As such the passenger side view mirror cannot be mounted to a non-existing door, and a plastic door cannot take the weight of such a rear view mirror. Therefore, a need exists for a mirror mounting bracket which is not attached to the passenger side door to permit the mounting of a passenger side view mirror to permit the driver to see what is behind and aside the vehicle to the right. The embodiment shown and described herein is intended for the line of Chrysler® Jeeps®.
[0002] It has also been considered that some nations such as the United Kingdom have the steering wheel on the right side of the vehicle as opposed to the left side of the vehicle as in the United States. In this case the passenger side would be on the left as opposed to the right. The mounting bracket of the invention can easily be adapted to be mounted on the left side of the vehicle. Thus the present invention would apply for left-hand drive vehicles as generally described herein as well as right-hand drive vehicles.
[0003] The mounting bracket may be employed with any other vehicle where the passenger door could be removed. This includes, but is not limited to the Jeep® family of vehicles. Further there may exist other circumstances where it would be desirable to place the mirror in such a position achieved through the use of the mounting bracket.
BRIEF SUMMARY OF THE INVENTION
[0004] The invention solves the above problems by providing a passenger side mirror mounting bracket which permits the driver of the vehicle to be able to view the mirror through the front windshield of the vehicle as opposed to the passenger window of the vehicle. The mounting bracket includes three basic portions. The first portion of the mounting bracket is generally rectangular and has the mirror attached to the distal portion of the first portion of the bracket. A second portion of the mounting bracket is angled and is secured to the right front fascia of the vehicle and to the proximal side of the first portion of the mounting bracket. A third portion of the mounting bracket is attached on it's first side to the passenger side pillar which is intermediate the passenger side door and the front windshield. The second side of the third portion of the bracket is also attached to the right side of the first portion of the mounting bracket. The attachments of each of the portions of the mounting bracket may include, but is not limited to, mechanical fasteners. The mounting bracket may be easily retrofit on appropriate vehicles and allows the driver to observe behind and aside the right side of the vehicle whilst looking through the front windshield of the vehicle.
[0005] In the United Kingdom vehicles which have the steering wheel on the right and the passenger side on the left. In this case the mounting bracket would be mounted identically as above with the exception that the second portion of the mounting bracket is secured to the left front fascia of the vehicle. Additionally, the second side of the third portion of the bracket would be attached to the left side of the first portion of the mounting bracket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a perspective view of a portion of the vehicle including a portion of the passenger door, the front pillar, the front windshield and the hood; and the mounting bracket with the passenger side mirror attached thereto.
[0007] FIG. 2 shows an exploded view of the mounting bracket for the passenger side mirror and the passenger side mirror.
[0008] FIG. 3 shows a partial side view of a first portion, partially in section view, of the mounting bracket with the passenger side mirror attached thereto.
[0009] FIG. 4 shows a top view of the first portion of the mounting bracket designed to receive the passenger side mirror thereon.
[0010] FIG. 5 shows a side view of the first portion of the mounting bracket.
[0011] FIG. 6 shows a top view of a second portion of the mounting bracket designed to connect the first portion of the mounting bracket to the right front fascia of the vehicle.
[0012] FIG. 7 shows a side view of the second portion of the mounting bracket designed to connect the first portion of the mounting bracket to the front fascia of the vehicle.
[0013] FIG. 8 shows an end view of the second portion of the mounting bracket designed to connect the first portion of the mounting bracket to the front fascia of the vehicle.
[0014] FIG. 9 shows a side view of one of many possible passenger side view mirrors which may be employed with the mounting bracket for such a passenger side mirror.
[0015] FIG. 10 shows a bottom view of one of many possible passenger side view mirrors which may be employed with the mounting bracket for such a passenger side mirror.
[0016] FIG. 11 shows front view of one of many possible passenger side view mirrors which may be employed with the mounting bracket for such a passenger side mirror.
[0017] FIG. 12 is a partial cutaway view of an embodiment of the mounting bracket including a light mounted thereon.
[0018] FIG. 13 . is an alternate embodiment of the bracket of the present invention for supporting a mirror on the driver side of the vehicle showing in a perspective view a portion of the vehicle including a portion of the driver door, the front pillar, the front windshield and the hood; and the mounting bracket with the side view mirror attached thereto.
[0019] The features of the invention will be best understood from the following description when read in connection with the following drawing figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] FIG. 1 , shows a perspective view of the mounting bracket 10 with the passenger side rear view mirror 14 attached thereto. For the rest of this discussion the passenger side rear view mirror 14 will be referred simply as the mirror 14 . For complete accuracy mirror 14 is an assembly which includes a housing 70 holding the mirror, a stem 75 and a tapered post 48 . The mirror 14 , per se, does not form part of the invention, the invention is directed to the mounting bracket 10 which receives the mirror assembly thereon. The mirror 14 and related elements are shown to more clearly show the apparatus and function of the mounting bracket 10 . FIG. 1 also shows the pivotable hood 12 , the non-movable rear hood element 110 , the gap 115 to allow the hood 12 to open, the passenger door 50 , the dashboard 18 , the front window 15 , the passenger side window 55 , a front fender 52 and the passenger side pillar 37 . The passenger side pillar 37 is intermediate the front window 15 and the passenger side window 55 . The passenger side pillar 37 includes a plurality of tapped holes 32 .
[0021] As shown in FIGS. 1 and 2 the mounting bracket 10 includes three major elements. The first element is the main support bracket 20 . The second element is an angled bracket connector 22 . The third element is a stabilizing bracket 24 . By interconnecting the main support bracket 20 , the angled bracket 22 and the stabilizing bracket 24 one can see the dashed line of sight 16 from the driver 100 with eye 101 through the front window 15 to the mirror 14 . This is how the mounting bracket 10 allows the driver 100 to see what is behind and aside the vehicle on the right side by not looking through the passenger side window 55 .
[0022] FIG. 2 shows an exploded view of the mounting bracket 10 and the relationship of the main support bracket 20 , the angled bracket connector 22 and the stabilizing bracket 24 to the fasteners which connect each bracket portion to one another.
[0023] The main support bracket 20 has a distal end 80 and a proximal end 82 . The distal end 82 includes a vertical aperture 40 and a horizontal aperture 26 . The vertical aperture 40 and the fastener 34 and washer 36 are described in FIG. 3 .
[0024] The main support bracket 20 at proximal end 80 , has a plurality of apertures 44 (best seen in FIG. 4 ).
[0025] The angled bracket connector 22 has a first side 84 and a second side 86 . The first side 84 and the second side 86 are generally about the same length and are bent at point 88 causing an angular separation 50 . The angular separation 51 may be between 20 and 70 degrees. The angular separation 51 shown here is about 45 degrees. On the first side 84 are a plurality of apertures 42 (best seen in FIG. 6 ). The number of apertures on the main support bracket 20 distal end 80 are equal and are in alignment with the plurality of apertures 42 on the first side 84 of the angled bracket connector 22 . As shown in FIG. 4 and FIG. 6 . There are three apertures on both the main support bracket 20 and the angled bracket connector 22 . Returning to FIG. 2 , 3 bolts 38 and 3 washers 36 secure the proximal end 82 of the main support bracket 20 to the first side 84 of the angled bracket connector 22 . In FIG. 2 only 2 bolts 38 and 3 washers 36 are visible, the third bolt 38 and third washer 36 is obscured by being directly in line with one of the other fastener combinations.
[0026] On the second side 86 of the angled bracket connector 22 are a pair of apertures 46 . A pair of bolts 30 secure the angled bracket connector 22 and the attached main support bracket bracket 20 to the right front fascia 17 of the vehicle.
[0027] The stabilizing bracket 24 is connected to the passenger side pillar 37 by bolt 30 ′. The stabilizing bracket 24 is further connected to the main support bracket 20 horizontal aperture 26 by bolt 28 .
[0028] FIG. 3 shows a partial side view in section of a first portion 20 of the mounting bracket 10 with the passenger side mirror 14 attached thereto. A mechanical fastener 34 and washer 36 are shown attached to the tapered post 48 which is received in the vertical aperture 40 on the distal end 80 of the main support bracket 20 .
[0029] FIGS. 4 and 5 focus on the main support bracket 20 . The main support bracket has a distal end 80 and a proximal end 82 . The distal end 80 of the main support bracket 20 is designed to receive the mirror 14 . The distal end 80 is thicker than the proximal end 82 , and includes an aperture 40 to allow the mirror 14 to be interfit and then secured by fastener 34 coming upwards through aperture 40 . The proximal end 82 includes a plurality of apertures 44 (best seen in FIG. 4 ). The number of apertures 44 may be chosen to be three. The length of the main support bracket 20 is such that it does not interfere with the opening of the hood 12 .
[0030] FIGS. 6 to 8 focus on the angled bracket connector 22 . The angled bracket connector 22 has a first side 84 and a second side 86 . The angled bracket connector 22 is bent at point 88 forming an angle 51 (best shown in FIG. 7 ) which is in the range of 20 to 70 degrees and may be chosen to be somewhere about 45 degrees.
[0031] The first side 84 of the angled bracket connector 22 includes a plurality of apertures 42 . The number of apertures 42 on the first side 84 of the angled bracket connector 22 is chosen to be the same as the plurality of apertures 44 on the proximal end 82 of the main support bracket 20 .
[0032] FIGS. 9 to 11 show an embodiment of a mirror 14 which may be adapted to be employed with the mounting bracket 10 . FIG. 9 shows a side view mirror 14 with a tapered post 48 designed to interfit into tapered bore 40 (best seen in FIG. 4 ) and secured therein by nut 34 (best seen in FIG. 2 ). FIG. 10 shows the bottom view of the mirror 14 . Aperture 40 is provided to receive the nut 34 therein after it passes through aperture 40 attaching the mirror 14 to the main support bracket 20 . Although not shown it has been contemplated that the mirror 14 may include warming elements to prevent frost of moisture build-up. In addition, mirror 14 may include a small motor or other system to allow it to be adjusted from the interior of the vehicle allowing the mirror 14 to move to the right, left or up and down. FIG. 11 is a front view of the mirror 14 , what driver 100 would view and see the side of the vehicle through mirror portion 65 and a magnified portion 65 ′ of what is to the rear right side of the vehicle.
[0033] FIG. 12 is a partial cutaway view of an embodiment of the mounting bracket 10 including an accessory element such as a light assembly 90 mounted thereon. The light assembly 90 would be powered by the vehicle through a pair of electrical wires 91 . An additional aperture 95 would be located at the distal end 80 ′ of the main support bracket 20 ′. A nut 93 would secure the light assembly 90 . The light assembly 90 may include a stem 92 and includes a bulb 94 . The light assembly 90 may be rotatable. The light assembly 90 may also be combined with a mirror 14 ′ as previously described. Other accessory elements may be mounted on the main support bracket 20 ′ in combination with assembly 90 or separately, such as an antenna (not shown) to permit one or two way radio or other band communication.
[0034] In an alternate mounting arrangement, as seen in FIG. 13 , the mounting bracket 10 ″ is mounted for the driver to view the driver's side view mirror 14 ″ through the windshield 15 . For example, when the driver's door 50 ″ is removed, the driver's side view mirror 14 ″ can be viewed through the windshield 15 or alternatively it may be desirable to locate the driver's side view mirror 14 ″ to be seen through the windshield 15 . In this alternate embodiment, the main support bracket 20 ″ would be mounted on bracket connector 22 ″ and connector 22 ″ would be attached to the fascia 17 of the vehicle in front of the driver 100 so the driver's line of site 16 ″ is through the windshield 15 to mirror 14 ″ and to the driver's side of the vehicle as shown in FIG. 13 . Connector 22 ″ is connected to fascia 17 with bolts 30 ″. Likewise stabilizing bracket 24 ″ provides a support between bracket 20 ″ and pillar 37 ″ and is connected to same with bolt 30 ″. Parts designated and shown in FIG. 13 with a double prime (″) indication are the same or similar to similar parts in FIG. 1 , but the double prime indicates the part is for the driver's side of the vehicle. It is further contemplated that a vehicle can have two mirrors of the present invention mounted on separate brackets on the fascia 17 of the vehicle in order that the driver 100 can be able to view and see both mirrors 14 and 14 ″ as shown individually in FIG. 1 and FIG. 13 through the windshield 15 .
[0035] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention.
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A mounting bracket is disclosed for mounting a mirror on the passenger side of a vehicle in a manner such that the driver of the vehicle will be able to directly view the mirror through the front windshield of the vehicle as opposed to the passenger window of the vehicle and accordingly view the space on the side of the vehicle. The mounting bracket supports the mirror and is secured to the right front fascia of the vehicle. An additional side connector connects the bracket portion near the mirror to the pillar of the right side of the vehicle. The pillar is intermediate the front windshield and the passenger side window. Additionally, the mounting bracket may be adapted to vehicles which have their steering wheel on the right side and the mounting bracket may be used on the driver side for the driver to view the side view mirror through the windshield.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a microscope objective, and more particularly, to a microscope objective suitable for ultra-violet radiation with a wavelength of about 250 nm.
2. Discussion of the Related Art
One example of microscope objective usable for ultra-violet radiation of about 250 nm wavelength is disclosed in Japanese Laid-Open Patent Publication 5-72482. This objective is composed of a first lens group including meniscus lenses and concave-convex cemented lenses (achromatic doublet or the like), a second lens group containing at least two three-piece cemented lenses (lens triplet or the like), and a third lens group containing concave-convex cemented lenses.
Fluorite (CaF 2 ), quartz, and "Ultran 30" (Trademark of Schott Co.) are optical materials that are considered to have sufficient transmission rates in the neighborhood of the 250 nm wavelength. However, since these optical materials do not have large differences in the Abbe number, the conventional microscope objective must use many three-piece cemented lenses (lens triplet) to achieve achromatism.
At present, only silicon type adhesives are available as the adhesive that has a sufficient transmission rate in the neighborhood of 250 nm wavelength. However, the bonding power of the silicon type adhesive is weak, and thus, it is difficult to produce a highly precise three-piece cemented lens. Therefore, even though such a lens may be designed, the actual production is extremely difficult.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a microscope objective that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a microscope objective usable in the ultra-violet range without using a three-piece cemented lens.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention provides a microscope objective including a plurality of meniscus lenses disposed along a predetermined optical axis; a plurality of first doublets aligned along the optical axis and disposed behind the plurality of meniscus lenses; and a plurality of second doublets aligned along the optical axis and disposed behind the plurality of first doublets, wherein a distance between a rearmost one of the first doublets and a front one of the second doublets is larger than a distance between any two adjacent ones of the first doublets and a distance between any two adjacent ones of the second doublets.
In another aspect, the present invention provides a microscope objective including two meniscus lenses disposed along an optical axis adjacent the object, the two meniscus lenses each having concave surfaces on front sides; seven first doublets aligned along the optical axis and disposed behind the meniscus lenses, wherein each of the seven first doublets includes a positive lens and a negative lens aligned along the optical axis; and two second doublets aligned along the optical axis and disposed behind the first doublets, wherein each of the two second doublets includes a positive lens and a negative lens aligned along the optical axis, wherein in each of four front ones of the first doublets, the negative lens is located on the front side, and in each of three rear first doublets, the positive lens is located on the front side, and wherein in a front one of the second doublets, the positive lens is located on the front side, and in a rear one of the second doublets, the negative lens is located on the front side.
In another aspect, the present invention provides a microscope objective including two meniscus lenses disposed along an optical axis adjacent the object, the two meniscus lenses each having concave surfaces on front sides; seven first doublets aligned along the optical axis and disposed behind the meniscus lenses, wherein each of the seven first doublets includes a positive lens and a negative lens aligned along the optical axis; and two second doublets aligned along the optical axis and disposed behind the first doublets, wherein each of the two second doublets includes a positive lens and a negative lens aligned along the optical axis, wherein in each of four front ones of the first doublets, the negative lens is located on the front side, and in each of three rear first doublets, the positive lens is located on the front side, wherein in a front one of the second doublets, the positive lens is located on the front side, and in a rear one of the second doublets, the negative lens is located on the front side, and wherein a distance between a rearmost one of the first doublets and a front one of the second doublets is larger than a distance between any two adjacent ones of the first doublets and a distance between any two adjacent ones of the second doublets.
In another aspect, the present invention provides a microscope objective including, in the following order from an object side, a front lens group; and a rear lens group aligned with the front lens group, wherein the front lens group includes two meniscus lenses having concave surfaces facing the object side, and seven doublets, each of the seven doublets being formed by cementing a positive lens and a negative lens, and the rear lens group includes two doublets, each of the two doublets being formed by cementing a positive lens and a negative lens.
In a further aspect, the present invention provides a microscope objective including, in the following order from the object side, a front lens group and a rear lens group, wherein the front lens group contains two meniscus lenses having concave surfaces facing the object side, and seven doublets, each of which is formed by cementing a positive lens and a negative lens, and the rear lens group contains two doublets which are formed by cementing a positive lens and a negative lens.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a cross-sectional view of a microscope objective according to a first preferred embodiment;
FIG. 2 is various aberration diagrams of a microscope objective according to the first preferred embodiment;
FIG. 3 is a cross-sectional view of a microscope objective according to a second preferred embodiments;
FIG. 4 is various aberration diagrams of a microscope objective according to the second embodiment; and
FIG. 5 is a cross-sectional view of an imaging lens.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
FIGS. 1 and 3 illustrate the first and second preferred embodiments according to the present invention, respectively. The objectives of these embodiments each have a front lens group G F on the object side and a rear lens group G R on the other side. From the object side, the front lens group G F includes two meniscus lenses L 1 and L 2 , each having its concave surface facing toward the object. After the two meniscus lenses and seven doublets D 1 to D 7 , each of which is formed by cementing a positive lens and a negative lens. The rear lens group G R includes two doublets D 8 , D 9 , formed by cementing a positive lens and a negative lens.
The dimensions and composition of the first and second embodiments are listed in Table 1 and Table 2, respectively. At the top of each Table, f represents the focal length, D 0 represents the object point distance, and N.A. represents the numerical aperture of the objective as a whole. In each Table, the first column represents the number of lens surfaces from the object side, the second column r represents the radius of curvature of each lens surface, the third column d represents the distance between two adjacent lens surfaces, and the fourth column shows the material of each lens. The fifth, sixth, and seventh columns represent indices of refraction, n 246 , n 242 , and n 250 for the wavelengths λ=246 nm, 242 nm, and 250 nm, respectively, for each lens. The eighth column v represents the Abbe number based on indices of refraction for these lenses at a wavelength centered at λ=246 nm. The material U30 denotes "Ultran 30".
TABLE 1______________________________________f = 2.0 D.sub.0 = 0.34 N.A. = 0.900r d Material n.sub.246 n.sub.242 n.sub.250 ν______________________________________1 -1.68 1.64 quartz 1.50952 1.51189 1.50729 110.82 -1.59 0.053 -5.28 1.60 fluorite 1.46863 1.47021 1.46714 153.14 -3.82 0.055 -11.04 0.80 quartz 1.50952 1.51189 1.50729 110.86 10.23 5.00 fluorite 1.46863 1.47021 1.46714 153.17 -5.77 0.108 300.00 1.00 quartz 1.50952 1.51189 1.50729 110.89 7.86 5.00 fluorite 1.46863 1.47021 1.46714 153.110 -14.32 0.1011 90.00 1.00 quartz 1.50952 1.51189 1.50729 110.812 7.72 5.00 fluorite 1.46863 1.47021 1.46714 153.113 -18.00 0.1014 250.00 1.00 quartz 1.50952 1.51189 1.50729 110.815 7.51 3.50 fluorite 1.46863 1.47021 1.46714 153.116 -45.09 1.0017 200.00 3.00 fluorite 1.46863 1.47021 1.46714 153.118 -8.59 1.00 quartz 1.50952 1.51189 1.50729 110.819 -216.34 1.0020 200.00 2.50 fluorite 1.46863 1.47021 1.46714 153.121 -7.87 1.00 quartz 1.50952 1.51189 1.50729 110.822 -1680.00 1.0023 200.00 2.50 fluorite 1.46863 1.47021 1.46714 153.124 -6.85 1.00 quartz 1.50952 1.51189 1.50729 110.825 26.08 14.0026 6.32 4.00 quartz 1.50952 1.51189 1.50729 110.827 -6.00 1.00 fluorite 1.46863 1.47021 1.46714 153.128 5.15 1.5029 -3.66 1.00 fluorite 1.46863 1.47021 1.46714 153.130 3.99 3.00 quartz 1.50952 1.51189 1.50729 110.831 -13.00______________________________________
TABLE 2______________________________________f = 2.0 D.sub.0 = 0.34 N.A. = 0.900r d Material n.sub.246 n.sub.242 n.sub.250 ν______________________________________1 -1.72 1.64 U30 1.60649 1.60929 1.60387 112.12 -1.66 0.053 -5.08 1.60 fluorite 1.46863 1.47021 1.46714 153.14 -3.95 0.055 -9.95 0.80 quartz 1.50952 1.51189 1.50729 110.86 9.73 5.00 fluorite 1.46863 1.47021 1.46714 153.17 -5.66 0.108 300.00 1.00 quartz 1.50952 1.51189 1.50729 110.89 7.54 5.00 fluorite 1.46863 1.47021 1.46714 153.110 -14.27 0.1011 90.00 1.00 quartz 1.50952 1.51189 1.50729 110.812 7.49 5.00 fluorite 1.46863 1.47021 1.46714 153.113 -18.00 0.1014 250.00 1.00 quartz 1.50952 1.51189 1.50729 110.815 7.78 3.50 fluorite 1.46863 1.47021 1.46714 153.116 -48.96 1.0017 200.00 3.00 fluorite 1.46863 1.47021 1.46714 153.118 -8.91 1.00 quartz 1.50952 1.51189 1.50729 110.819 -127.26 1.0020 200.00 2.50 fluorite 1.46863 1.47021 1.46714 153.121 -8.00 1.00 quartz 1.50952 1.51189 1.50729 110.822 -1220.00 1.0023 200.00 2.50 fluorite 1.46863 1.47021 1.46714 153.124 -6.81 1.00 quartz 1.50952 1.51189 1.50729 110.825 23.91 14.0026 6.18 4.00 quartz 1.50952 1.51189 1.50729 110.827 -6.00 1.00 fluorite 1.46863 1.47021 1.46714 153.128 5.22 1.5029 -3.60 1.00 fluorite 1.46863 1.47021 1.46714 153.130 3.91 3.00 quartz 1.50952 1.51189 1.50729 110.831 -13.00______________________________________
As shown in Tables 1 and 2, in both embodiments, a distance between a rearmost one of the first doublets and a front one of the second doublets (see the 25th row in the tables) is larger than a distance between any two adjacent ones of the first doublets and a distance between any two adjacent ones of the second doublets.
FIGS. 2 and 4 each show the spherical aberration, astigmatism, chromatic aberration of magnification, coma, and distortion of the objectives of the first and second embodiments, respectively. In the diagrams for the spherical aberration, chromatic aberration of magnification, and coma, solid lines represent wavelength λ=246 nm; dotted lines represent wavelength λ=242 nm; and one-dot-chain lines represent wavelength λ=250 nm. In the astigmatism diagram, solid lines represents the sagittal image plane and the dotted lines represent the meridional image plane. N.A. represents the numeral aperture and Y represents the image height.
The aberration diagram in both embodiments shown in FIGS. 2 and 4 indicate that the aberrations are favorably corrected at 246±4 nm with the field number (field of view) of 20.
Both the first and second embodiments have been discussed herein with respect to the application of ultra violet radiation. However, the present invention can be applied equally well for visible light.
The objective in each embodiment is of infinite correction type and each aberration diagram above is imaged using an imaging lens L IM , as shown in FIG. 5. The dimensions and composition of the imaging lens L IM are listed in Table 3 below.
TABLE 3______________________________________r d Material n.sub.246 n.sub.242 n.sub.250 ν______________________________________1 -30.63 2.00 quartz 1.50952 1.51189 1.50729 110.82 2406.00 5.00 fluorite 1.46863 1.47021 1.46714 153.13 -39.10 1.004 -417.40 5.00 fluorite 1.46863 1.47021 1.46714 153.15 -51.84______________________________________
With the structure described above, a microscope objective with sufficient achromatism may be obtained without using a three-piece cemented lens.
In order to eliminate both the on-axis chromatic aberration and the chromatic aberration of magnification by a single objective, it is preferable to make the seven doublets in the front lens group achromatic and the two doublets in the rear lens group dispersive (generating chromatic abberation on purpose). Hence, for each doublet in the front lens group, the Abbe number of the positive lens is preferably larger than the Abbe number of the negative lens, while for each doublet in the rear lens group, the Abbe number of the positive lens is preferably smaller than the Abbe number of the negative lens.
Moreover, as shown in FIGS. 2 and 4, in order to effectively perform achromatism in the front lens group G F , the cemented surfaces in the four doublets D 1 , to D 4 on the object side are preferably made into convex shapes facing the object, while the cemented surfaces in the three doublets D 5 to D 7 arranged on the image side are preferably made into concave shapes with respect to the object.
The present invention realizes a microscope objective with favorable achromatism without using a three-piece cemented lens (triplet).
It will be apparent to those skilled in the art that various modifications and variations can be made in the microscope objective of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Provided is a microscope objective including a plurality of meniscus lenses disposed along a predetermined optical axis; a plurality of first doublets aligned along the optical axis and disposed behind the plurality of meniscus lenses; and a plurality of second doublets aligned along the optical axis and disposed behind the plurality of first doublets, wherein a distance between a rearmost one of the first doublets and a front one of the second doublets is larger than a distance between any two adjacent ones of the first doublets and a distance between any two adjacent ones of the second doublets.
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This is a divisional of application Ser. No. 08/068,513, filed on May 27, 1993, now U.S. Pat. No. 5,435,390, issued Jul. 25, 1995.
FIELD OF THE INVENTION
The field of this invention relates to methods and devices usable in the field of oil and gas exploration and production, more specifically devices and methods related to cementing operations involving the cementing of a liner by dropping or by pumping down a plug.
BACKGROUND OF THE INVENTION
Cementing operations have involved the use of plugs as a way of correctly positioning the cement when setting a liner. Some mechanisms have employed the use of pressure or vacuum to initiate plug movement downhole for proper displacement of the cement to its appropriate location for securing the liner properly. The early designs were manual operations so that when it was time to release a plug for the cementing operation, a lever was manually operated to accomplish the dropping of the plug. This created several problems because the plug-dropping head would not always be within easy access of the rig floor. Frequently, depending upon the configuration of the particular well being drilled, the dropping head could be as much as 100 ft. or more in the derrick. In order to properly actuate the plug to drop, rig personnel would have to go up on some lift mechanism to reach the manual handle. This process would have to be repeated if the plug-dropping head had facilities for dropping more than one plug. In those instances, each time another plug was to be dropped, the operator of the handle would have to be hoisted to the proper elevation for the operation. In situations involving foul weather, such as high winds or low visibility, the manual operation had numerous safety risks. Manual operations used in the past are illustrated in U.S. Pat. No. 4,854,383. In that patent, a manual valve realignment redirected the flow from bypassing the plug to directly above it so that it could be driven downhole.
Hydraulic systems involving a stationary control panel mounted on the rig floor, with the ability to remotely operate valves in conjunction with cementing plugs, have also been used in the past. Typical of such applications is U.S. Pat. No. 4,782,894. Some of the drawbacks of such systems are that for unusual applications where the plug-dropping head turned out to be a substantial distance from the rig floor, the hoses provided with the hydraulic system would not be long enough to reach the control panel meant to be mounted on the rig floor. Instead, in order to make the hoses deal with these unusual placement situations, the actual control panel itself had to be hoisted off the rig floor. This, of course, defeated the whole purpose of remote operation. Additionally, the portions of the dropping head to which the hydraulic lines were connected would necessarily have to remain stationary. This proved somewhat undesirable to operators who wanted the flexibility to continue rotation as well as up or down movements during the cementing operation. Similar such remote-control hydraulic systems are illustrated in U.S. Pat. Nos. 4,427,065; 4,671,353.
Yet other systems involve the pumping of cement on the rig floor to launch a ball or similar object, the seating of which would urge the cementing plug to drop. Typical of such a system is U.S. Pat. No. 5,095,988. U.S. Pat. No. 4,040,603 shows the general concept of a plug-release mechanism using a hydraulic circuit mounted on the rig floor. U.S. Pat. No. 5,033,113 shows generally the concept of using an infrared receiver to trigger the operation of a device such as an electric fan.
One type of previously used plug-dropping head is the model TD put out by Baker Oil Tools. This device has a plug stop to retain the plug, with a shifting sleeve which in a first position allows the flow to bypass around the plug being retained by the plug stop. Upon manual turning of a set screw, the sleeve shifts, allowing the plug stop to pivot so that the plug is released. The shifting of the sleeve also closes the bypass around the sleeve and forces pressure on top of the plug so that it is driven down into the wellbore in the cementing operation.
The apparatus of the present invention has been designed to achieve several objectives. By putting together an assembly that can be actuated by remote control from a safe location on the rig floor, the safety aspects of plug dropping have been improved. No longer will an operator be required to go up in the derrick to actuate a single or multiple levers in the context of liner cementing. Use of the apparatus and method of the present invention also eliminates numerous hydraulic hoses that need to be extended from a control panel to the final element necessary to be operated to allow the plug to drop. The plug can be dropped while the rotary table is in operation such that not only rotation but movement into and out of the wellbore is possible as the plug is being released to drop. The equipment is designed to be intrinsically safe to avoid any possibility of creation of a spark which could trigger an explosion. The equipment is compact and economically accomplishes the plug-dropping maneuver while the operator stands in a safe location on the rig floor. The actuation to drop can be accomplished on the fly while the plug-dropping head is being rotated or being moved longitudinally. Plug-dropping heads can be used in tandem and be made to respond to discrete signals. This ensures that the plugs are released in the proper order from a safe location on the rig.
SUMMARY OF THE INVENTION
An apparatus and method of dropping a pumpdown plug or ball is revealed. The assembly can be integrally formed with a plug-dropping head or can be an auxiliary feature that is mounted to a plug-dropping head. The release mechanism is actuated by remote control, employing intrinsically safe circuitry. The circuitry, along with its self-contained power source, actuates a primary control member responsive to an input signal so as to allow component shifting for release of the pumpdown plug or ball. Multiple plug-dropping heads can be stacked, each responsive to a discrete release signal. Actuation to drop the pumpdown ball or plug is accomplished even while the components are rotating or are moving longitudinally. Using the apparatus and method of the present invention, personnel do not need to climb up in the derrick to actuate manual valves. There is additionally no need for a rig floor-mounted control panel with hydraulic lines extending from the control panel to remotely located valves for plug or ball release.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an existing prior art plug-dropping head for which a preferred embodiment has been developed.
FIGS. 2A and 2B illustrate the plug-dropping head of FIG. 1, with a few parts removed for clarity, illustrated with the release mechanism of the apparatus and method of the present invention installed and ready to release.
FIG. 3 illustrates the piston/cylinder combination in the initial position before release of the plug.
FIG. 4 is the same piston/cylinder combination of FIG. 3 in the unlocked position after plug release.
FIG. 5 is an end view of the view shown in FIG. 2, illustrating the spring action feature.
FIG. 6 is a detail of FIG. 1, showing the existing pin which is changed to accept the invention.
FIG. 7 is a sectional elevational part exploded view of the apparatus.
FIG. 8 is a sectional view of the apparatus showing the rack.
FIG. 9 is an electrical schematic representation of the transmitter used in the invention.
FIGS. 10 and 11 represent the electrical schematic layout of the components to receive the signal from the transmitter and to operate a valve to initiate release of a ball or plug.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a prior art plug-dropping head available from Baker Oil Tools. The preferred embodiment of the apparatus and invention has been configured to be mountable to the plug-dropping head illustrated in FIG. 1 as an addon attachment. However, those skilled in the art will appreciate that an integral plug-dropping head, with the remote-release mechanism which will be described, can be provided without departing from the spirit of the invention.
In the prior design shown in FIG. 1, a top connection 1 is supported from the derrick in the customary manner. Top connection 1 is connected to a mandrel 9, which is in turn connected to a bottom connection 12. Inside mandrel 9 is sleeve 8. At the bottom of sleeve 8 is plug stop 10, which is connected by roll pin 11 to sleeve 8. In the position shown in FIG. 1, plug stop 10 would retain a ball or plug above it since it extends transversely into the central flowpath. With the sleeve 8 shown in the position in FIG. 1, flow bypasses a plug (not shown) which is disposed atop plug stop 10. Flow which comes in through top connection 1 circulates through a bypass passage 13 until it is time to drop the ball or plug. At that time, set screw 3 is operated and turned 180° manually. The turning of set screw 3 releases its hold on sleeve 8 and allows sleeve 8 to drop down. As a result of sleeve 8 dropping down, plug stop 10 can pivot around roll pin 11 and the plug or ball is released. Additionally, sleeve 8 comes in contact with bottom connection 12, thereby sealing off bypass passage 13. Thereafter, circulation into top connection 1 can no longer go through bypass passage 13 and must necessarily bear down on the ball or plug in the central port or passage 15, which results in a pressure being applied above the plug or ball to drive it through bottom connection 12 and into the liner being cemented in the well.
As previously stated, the operation described in the previous paragraph, with regard to the prior art tool of FIG. 1, at times necessitated sending personnel significant distances above the rig floor for manual operation of set screw 3. Of course, rotation and longitudinal movement of the tool shown in FIG. 1 had to stop in order for set screw 3 to be operated to release sleeve 8.
Referring now to FIG. 2, the tool in FIG. 1 is shown with many of the component omitted for clarity. At the top, again, is top connection 1, which is connected to mandrel 9, which is in turn connected to bottom connection 12. Sleeve 8 sits within mandrel 9, and pin 11 secures the plug stop (not shown) in the position to retain a ball or plug in the position shown in FIG. 2. It should be noted that the tool shown in FIG. 1 is in the same position when shown in FIG. 2. That is, the plug stop 10 retains the plug while the flow goes around the sleeve 8, through the passage 13. Ultimately, when sleeve 8 shifts, tapered surface 16 contacts tapered surface 18 on bottom connection 12 to seal off passage 13 and to direct flow coming into top connection 1 through the central passage 15 to drive down the ball or plug into the wellbore.
However, there is a difference between the assembly shown in FIG. 2 and the assembly shown in FIG. 1. Set screw 3 of FIGS. 1 and 6 has been replaced by a totally different assembly which eliminates the manual operation with respect to the embodiment shown in the prior art of FIG. 1. Instead, a housing 20 has been developed to fit over top connection 1 until it comes to rest on tapered surface 22. The housing 20 has a mating tapered surface 24 which, when it contacts tapered surface 22, longitudinally orients housing 20 with respect to top connection 1.
Rotational orientation is still properly required. To accomplish this, at least one orienting groove or cutout 26 has been machined into top connection 1. For each cutout 26 there is an alignment bore 28 in housing 20. A bolt 30 is advanced through threaded bore 28 until it sticks into and firmly engages cutout 26. Once at least one bolt 30 is inserted into a cutout 26, the radial orientation between housing 20 and top connection 1 is obtained. That orientation can be secured with set screws (not shown) inserted through threaded bores 32 and 34. At that point, not only is housing 20 properly oriented, but its orientation is properly secure. As a result of such orientation, bore 36 in top connection 1 is aligned with bore 38 in housing 20. Bores 36 and 38 are disposed at an angle with respect to the longitudinal axis of top connection 1. A preferably square thread 40 is located in bore 36. Instead of set screw 3 (see FIG. 6), a pin 42 (see FIG. 7) is installed through aligned bores 36 and 38. Threads 44 on pin 42 engage thread 40 in bore 36.
FIG. 7 outlines the assembly procedures for the installation of pin 42. After aligning housing 20, as previously described, the cover 46 (see FIG. 2) is removed, allowing access to bore 38 for installation of pin 42. Pin 42 is advanced and rotated into threads 40 until tapered surface 48 is in an orientation about 180° opposed from that shown in FIG. 7. The orientation of surface 48 is determined by the orientation of bore 50, which does not extend all the way through pin 42. Bore 50 is designed to accept a handle 52 (see FIG. 2). The orientation of tapered surface 48 is known by the orientation of bore 50. Having aligned tapered surface 48 in a position about 180° opposed from that shown in FIG. 7, the gear 54 is fitted over pin 42 and handle 52 is extended into bore 50. By extending handle 52 through catch 56 on gear 54, the longitudinal positioning of gear 54 with respect to pin 42 is accomplished. Additionally, the orientation of catch 56 allows initial rotation of both pin 42 and gear 54 to get them into the set position shown in FIG. 2.
Prior to securing the gear 54 onto pin 42, a pair of split sleeves 58 are fitted to housing 20 and secured to each other by fasteners 60. A rack 62 (see FIG. 8) is secured to sleeves 58 via fasteners 64 (see FIG. 7).
As shown in FIG. 8, gear 54 meshes with rack 62 such that rotation of pin 42 will rotate sleeves 58. Also connected to sleeves 58, as shown in FIG. 8, are lug or lugs 66. In the preferred embodiment there are two lugs 66 secured to sleeves 58 (see FIG. 5). Typically for each one, a bolt 68 extends through a piston 70 to secure the piston 70 to lug 66 (see FIGS. 5 and 8). The piston 70 is an elongated member that extends through a cylinder 72 and is sealed thereto by O-ring seal 74. Disposed between piston 70 and cylinder 72 is floating piston 76, which is sealed against cylinder 72 by seal 78 and it is further sealed against piston 70 by seal 80. A first port 82 allows fluid communication into cavity 84, which is formed between cylinder 72 and piston 70 and between seal 74 on piston 70 and seal 80 on floating piston 76. A second port 86 is also disposed in cylinder 72 and communicates with cavity 88. Cavity 88 is disposed between piston 70 and cylinder 72 on the other side of seal 74.
Cylinder 72 has a mounting lug 90. Bolt 92 secures cylinder 72 in a pivotally mounted orientation to housing 20.
Referring back to lugs 66, each has a bracket 94 (see FIG. 5) to secure an end of spring 96. A lug 98 is rigidly mounted to housing 20 (see FIG. 8) and secures the opposite end of spring 96. Spring 96 extends spirally around sleeves 58.
It should be noted that while one particular piston cylinder assembly has been described, a plurality of such identical assemblies or similar assemblies can be used without departing from the spirit of the invention. There are two in the preferred embodiment. In essence, the preferred embodiment illustrates the preferred way to accomplish a desired movement which is responsive to a particular signal for remote release of the ball or plug.
The first port 82 has a line 100 leading to a check valve 102 and a commercially available, intrinsically safe solenoid valve 104 mounted in parallel (see FIG. 3). The use of check valve 102 is optional. Coming out of solenoid valve 104 is line 106 which leads back to second port 86. Cavities 84 and 88, as well as lines 100 and 106 are filled with an incompressible fluid. Solenoid valve 104 is electrically operated and is of the type well-known in the art to be intrinsically safe. This means that it operates on such low voltage or current that it will not induce any sparks which could cause a fire or explosion. The electrical components for the apparatus A of the present invention are located in compartment 108 of housing 20 (see FIG. 8). A sensor 110 (see FIGS. 3 and 8) is mounted in each of bores 112 in housing 20. Each of the sensors 110 is connected to the electronic control system 114. The power for the electronic control system 114 comes from a battery 116. Sensor 110 receives over the air a signal 118 from a control 120. In the preferred embodiment, the drilling rig operator holds the control 120 in his hand and points it in the direction of sensors 110, which are distributed around the periphery of housing 20 and oriented in a downward direction. The preferred embodiment has six sensors 110. The rig operator points the control 120, which is itself an intrinsically safe device, which emits a signal 118 that ultimately makes contact over the air with one of sensors 110. The signal can be infrared or laser or any other type of signal that goes over the air and does not create any explosive fire or other hazards on the rig. The effect of a signal 118 received at a sensor 110 is to actuate the control system 114 to open solenoid valve 104.
However, prior to explaining the actuation of the release, the initial set-up of the apparatus A needs to be further explained. As previously stated, pin 42 is installed in a position which is the fully released position. That position is, in effect, about 180° different from the orientation shown in FIG. 2. With that initial installation, gear 54 is secured to rack 62. At that point in time, the cylinder 72 is disposed in the position shown in FIG. 4, with the spring 96 fully relaxed except for any preload, if built in. When handle 52 is given a 180° rotation, it moves rack 62, which is connected to sleeves 58 as are lugs 66. Accordingly, 180° rotation of handle 52 has the net effect of rotating lugs 66 away from bracket or brackets 98 about 30°-45°. The difference in position of lugs 66 with respect to bracket 98 is seen by comparing FIGS. 3 and 4.
As a result of the 180° rotation of handle 52, pin 42 is now in the position shown in FIG. 2. By moving lugs 66 away from bracket 98, spring 96 has been stretched. In order to accommodate the rotational movement induced by handle 52, piston 70 must move to a position where it is more extended out of cylinder 72. In making this movement, cavity 88 must grow in volume while cavity 84 shrinks in volume. As a result, there is a net transfer of fluid, which could be oil or some other hydraulic fluid, through conduit 100 as cavity 84 is reduced in volume, through check valve 102, if used, and back into conduit 106 to flow into cavity 88 which is increasing in volume. During this time, of course, floating piston 76 experiences insignificant net differential pressure and merely moves to accommodate the change in volume of cavity 84. It should be noted that if check valve 102 is not used, the operator must use control 120 to trigger valve 104 to open prior to rotating handle 52. This is because without check valve 102, if valve 104 remains closed, it will not be possible to turn handle 52 because the rack 62 will not be free to move because piston 70 will be fluid-locked against movement into or out of cylinder 72. Therefore, if an assembly is used without check valve 102, the operator must ensure that valve 104 stays open as the orientation is changed from that shown in FIG. 4 to that shown in FIG. 3. In the preferred embodiment, a timer can be placed on valve 104 so that when it is triggered to open by control 120, it stays open for a predetermined time (about 4 minutes), thus giving the components time to make their required movements, both in the set-up and the release modes.
The result of the initial rotation of handle 52 about 180° in the preferred embodiment is that pin 42 suspends sleeve 8, which keeps plug stop 10 supporting the ball or plug 122 (see FIG. 7).
When it is time to release the ball or plug 122, the operator, standing in a safe location on the rig floor, aims the control 120 toward sensors 110. Having made contact over the air with a signal 118 transmitted from control 120 to one of the sensors 110, the control system 114 is actuated to open valve 104. When valve 104 is opened, the force in expanded spring 96 draws lugs 66 rotationally toward bracket 98. This is allowed to happen as fluid is displaced from cavity 84 through line 100 through valve 104 back through line 106 to cavity 88. As lug 66 rotates due to the spring force which is now no longer opposed by the hydraulic lock provided by having valve 104 in the closed position, the rotation of sleeve 58 rotates rack 62, which in turn rotates gear 54, which in turn rotates pin 42 from the position shown in FIG. 2 approximately 180° . This results in the release of sleeve 8 so that it can shift downwardly as previously explained. The downward shifting of sleeve 8 allows plug stop 10 to pivot on roll pin 11, thus removing the support for the ball or plug 122. The ball or plug 122 can drop. Its downward progress toward the liner being cemented can also be assisted by pumping down on top of the plug due to passage 13 being cut off upon shifting of sleeve 8, as in the original design shown in FIG. 1.
It should be noted that the housings 20 can be stacked in series, each equipped with sensors 110 that respond to different signals so that if there is a stack of housings 20 in use for a particular application requiring several plugs to be dropped, the sensitivity of sensors 110 on different housings 20 to different signals ensures that the plugs are dropped in the proper order. Accordingly, a separate controller 120 is provided for each apparatus A to be used in series, and aiming one controller with a discrete signal to a sensor 110 will not actuate the apparatus A unless the specific signal that sensor 110 is looking for is received. Alternatively, a single controller 120 can be programmed to give different signals 118 in series to accomplish release in the proper sequence.
The control 120 is further illustrated in FIG. 9. Control 120 comprises a hand-held transmitter having several components. The transmitter includes a tone generator 101, which generates a multiplicity of frequencies. In the preferred embodiment, the tone generator 101 generates 5 frequencies comprising 150 Hz, 300 Hz, 600 Hz, 1200 Hz, and 2400 Hz. Additionally, the tone generator 101 creates a carrier frequency of 38 kHz. The frequencies generated by the tone generator 101, except for the carrier frequency, are passed through a microsequencer 103, and ultimately to a mixer 105 where the carrier signal is mixed with the other frequencies generated. The mixed signal is then passed to an amplifier or power driver 107 for ultimate reception at sensors 110 (see FIG. 10). As can be seen from the table which is part of FIG. 9, a four-button selector is provided on the transmitter control 120. The first frequency sent, regardless of the combination selected, is 150 Hz, and the last signal sent is 2400 Hz. It should be noted that selecting different signal combinations on the control 120 will result in actuation of a different ball or plug 122 in an assembly involving a stack of units.
Referring now to FIG. 10, any one of the sensors 110 can pick up the transmitted signal and deliver it to the pre-amp and demodulator 109. The carrier frequency of 38 kHz is eliminated in the pre-amp and demodulator, and the individual frequency signals sent are sensed by the various tone decoders 111. Each of the tone decoders 111 are sensitive to a different frequency. When the tone decoder for the 150 Hz detects that frequency, it resets all of the latches 113. The latches 113 emit a binary output dependent upon the input from the tone decoders 113. When the last frequency is detected, that being the 2400 Hz frequency at the decoder 111, the latch 113 associated with the decoder for the 2400 Hz frequency enables the decoder 115 to accept the input from the remaining latches 113 to generate a suitable output which will ultimately trigger valve 104 to open. Again, depending on the binary input to the decoder 115, discrete signals result as the output from decoder 115, which result in a signal transmitted to one shot 117, shown in FIG. 11. The one shot 117 triggers a timer 119, which in the preferred embodiment is set for keeping the valve 104 in the open position for 4 minutes. The signal to timer 119 also passes to solenoid driver 121, which is a switch that enables the solenoid 123 to ultimately open valve 104. As a safety precaution to avoid release of any ball or plug 122 if the power supply becomes weak or is otherwise interrupted, there is a power on/off detector 125, which is coupled to a delay 127. If the available power goes below a predetermined point, the solenoid 123 is disabled from opening. Thereafter, if the power returns above a preset value, the requirements of time in delay 127 must be met, coupled with a subsequent signal to actuate solenoid 123, before it can be operated. The power supply to the control circuits is provided by a plurality of batteries that are hooked up in parallel. These batteries are rechargeable and are generally recharged prior to use of the assembly on each job. The batteries singly are expected to have sufficient power to conclude the desired operations.
In another safety feature of the apparatus, in making the initial rotation of handle 52 to set the apparatus A up for release, if for any time during the rotation of handle 52 it is released, check valve 102 will prevent its slamming back to its original position due to spring 96, which could cause injury to personnel. By use of check valve 102, the initial movement of handle 52 is ensured to be unidirectional so that it holds its ultimate position when released simply because the fluid in the circuit in lines 100 and 106 cannot flow from conduit 106 back to conduit 100 with check valve 102 installed and solenoid valve 104 closed.
It should be noted that the preferred embodiment having been illustrated, the scope of the invention is broad enough to encompass alternative mechanisms for creating the necessary motion to release a ball or plug 122 by virtue of a remote, over-the-air signal.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.
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An apparatus and method of dropping a pumpdown plug or ball is revealed. The assembly can be integrally formed with a plug-dropping head or can be an auxiliary feature that is mounted to a plug-dropping head. The release mechanism is actuated by remote control, employing intrinsically safe circuitry. The circuitry, along with its self-contained power source, actuates a primary control member responsive to an input signal so as to allow component shifting for release of the pumpdown plug or ball. Multiple plug-dropping heads can be stacked, each responsive to a discrete release signal. Actuation to drop the pumpdown ball or plug is accomplished even while the components are rotating or are moving longitudinally. Using the apparatus and method of the present invention, personnel do not need to climb up in the derrick to actuate manual valves. There is additionally no need for a rig floor-mounted control panel with hydraulic lines extending from the control panel to remotely located valves for plug or ball release.
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RELATED APPLICATION
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/637,541, filed Apr. 24, 2012, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed toward an energy transfer device that is configured to transmit energy released from the output of a first pyrotechnic device to a second pyrotechnic device in order to initiate firing of the second pyrotechnic device. The energy transfer device absorbs energy released by the output charge of the first pyrotechnic device, such as a time delay fuse, and directs at least a portion of the energy toward the second pyrotechnic device in a controlled manner so as to efficiently and reliably facilitate firing of the second pyrotechnic device.
[0004] 2. Description of the Prior Art
[0005] Pyrotechnic devices are commonly employed to ignite or detonate explosive charges in a variety of industrial applications such as oil well completion operations. Time delay fuses are exemplary pyrotechnic devices that can be used to initiate detonation of the explosive material used in the blasting operation. Time delay fuses are generally available in predetermined delay time increments. However, in certain applications, longer time delays are desired beyond what a single time delay fuse is configured to supply. In such instances, blasting operators may stack a plurality of fuses in series with the expectation that the output charge from one fuse will ignite the primer or ignition charge of the next fuse.
[0006] Time delay fuses generally are not designed or configured for use in this manner. Thus, in certain circumstances, the output charge from the time delay fuse can fail to ignite the adjacent fuse, thereby resulting in failure to detonate the primary explosive used in the blasting operation. In the context of downhole operations, failure to detonate the primary explosive may require that the tool including the primary explosive be run back up the hole and a new string of time delay fuses be installed. Pulling pipe string is an expensive and time-consuming operation. The presence of explosive devices further complicates this operation due to their inherently dangerous nature.
[0007] Therefore, there exists a need in the art for reliably effecting transfer of the output energy from one time delay fuse to another ensuring that the subsequent fuse in the chain ignites.
SUMMARY OF THE INVENTION
[0008] The present invention provides a solution to this problem by providing an energy transfer device configured to transfer the energy output from a first pyrotechnic device to a second pyrotechnic device for initiating firing of the second pyrotechnic device. In one embodiment, the energy transfer device comprises a metallic body having a forward section configured to be placed adjacent the first pyrotechnic device and an aft section configured to be placed adjacent the second pyrotechnic device. The metallic body further includes an axial passageway extending therethrough. The passageway includes a first segment extending through the body forward section and a second segment extending through the body aft section. The body forward section is deformable by the energy output from the first pyrotechnic device such that the diameter of the passageway first segment is narrowed thereby forming a constriction in the passageway.
[0009] According to another embodiment of the present invention, there is provided an energy transfer device configured to transfer the energy output from a first pyrotechnic device to a second pyrotechnic device for initiating firing of the second pyrotechnic device. The energy transfer device comprises a device housing including a central bore extending therethrough, and a device insert carried by the housing within the bore. The housing includes a housing forward section and a housing aft section. The insert comprises an insert forward section and an insert aft section and an axial passageway extending therethrough. The housing forward section and the insert forward section are configured for placement adjacent the first pyrotechnic device, and the housing aft section and the insert aft section are configured for placement adjacent the second pyrotechnic device. The insert forward section is deformable by the energy output from the first pyrotechnic device such that a constriction is formed in the passageway.
[0010] According to yet another embodiment of the present invention, there is provided a tool for delivering a pyrotechnic charge downhole in a well. The tool comprises a time delay fuse and an energy transfer device. The energy transfer device comprises a device housing including a central bore extending therethrough, and a device insert including an axial passageway extending therethrough. The device housing includes a housing forward section and a housing aft section. Likewise, the device insert also includes an insert forward section and an insert aft section. The device insert is configured to be positioned within the housing bore. The insert forward section is deformable by the energy output from a first pyrotechnic device such that a constriction is formed in the passageway.
[0011] In still another embodiment according to the present invention, there is provided a method of igniting a pyrotechnic charge downhole in a well. A first pyrotechnic device, an energy transfer device, and a second pyrotechnic device are provided. The energy transfer device comprises a metallic body having a forward section, an aft section, and an axial passageway extending therethrough. The first pyrotechnic device is ignited to detonate an output charge. At least a portion of the energy from the output charge is directed through the axial passageway toward the second pyrotechnic device thereby igniting the second pyrotechnic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an energy transfer device according to one embodiment of the present invention;
[0013] FIG. 2 is an exploded, perspective view of the energy transfer device of FIG. 1 illustrating the two-part construction thereof;
[0014] FIG. 3 is a schematic view of the energy transfer device utilized in a downhole tool in conjunction with time delay fuses;
[0015] FIG. 4 is a cross-sectional view of the energy transfer device insert in its pre-firing configuration; and
[0016] FIG. 5 is a cross-sectional view of the energy transfer device insert post-firing showing deformation of the insert and the formation of a passageway constriction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Turning now to the Figures, and in particular FIGS. 1 and 2 , an energy transfer device 10 according to one embodiment of the present invention is shown. Device 10 is a dynamic device that is configured to limit and convert a detonating output of a time delay fuse or similar device so that the output is suitable to ignite another time delay fuse or similar device without damaging the input and resulting in a failure to ignite. Device 10 is of two-piece construction comprising a device housing 12 and a device insert 14 . Housing 12 comprises a metallic body 13 that includes a generally cylindrical forward section 16 configured to be placed adjacent to and facing the pyrotechnic device that is supplying the energy to be transferred to another pyrotechnic device and a generally cylindrical aft section 18 configured to be placed adjacent to and facing the pyrotechnic device receiving the transferred energy. In certain embodiments, forward section 16 may have a larger outer diameter than aft section 18 . The outer surface of forward section 16 comprises threads 20 that permit housing 12 to be secured within a tool, such as might be used in downhole blasting operations. Body 13 comprises an axial bore 22 extending therethrough that is sized to receive device insert 14 . Bore 22 includes a forward segment 24 and an aft segment 26 , with said forward segment 24 generally having a greater diameter than aft segment 26 , although this need not always be the case.
[0018] Device insert 14 comprises a metallic member 28 including a forward section 30 and an aft section 32 . Forward section 30 is configured to be received within forward segment 24 of bore 22 , and aft section 32 is configured to be received within aft segment 24 of bore 22 . As best shown in FIG. 4 , insert 14 further comprises a central, axial passageway 34 extending therethrough comprising respective forward and aft segments 35 , 37 . In certain embodiments, forward segment 35 may present a length that is less than the length of segment 37 . Moreover, the diameter of segment 35 is less than the diameter of segment 37 .
[0019] As discussed in greater detail below, passageway 34 operates as a conduit directing the output energy from one pyrotechnic device located adjacent forward sections 16 and 30 toward the second pyrotechnic device located adjacent aft sections 18 and 32 . The forward section 30 of device insert 14 comprises a circumscribing channel 36 that is configured to receive an O-ring 38 . O-ring 38 provides a seal between insert 14 and housing 12 , and also assists in maintaining insert 14 within bore 22 upon assembly of device 10 .
[0020] Forward section 30 of insert 14 generally is of greater diameter than aft section 32 , thus corresponding with the general configuration of bore 22 . The junction between forward section 30 and aft section 32 comprises a shoulder 40 that abuts a similarly configured shoulder 42 defining the junction between forward section 16 and aft section 18 of housing 12 . The contacting engagement of both shoulders 40 , 42 ensures proper mating of insert 14 and housing 12 .
[0021] In certain embodiments, housing 12 and insert 14 can be manufactured from a variety of metals, including stainless steel, although different stainless steel alloys may be selected individually for each piece. In one particular embodiment, housing 12 may comprise 17-4 (AMS 5643) stainless steel, whereas insert 14 may comprise 304 or 304L stainless steel. In preferred embodiments, insert 14 comprises a metal having hardness and tensile strength values lower than the metal from which housing 12 is formed. As explained in greater detail below, manufacturing housing 12 and insert 14 from different materials permits insert 14 to undergo deformation upon firing of the first pyrotechnic device, while housing 12 resists deformation thereby permitting its reuse. It is notable, too, that device 10 does not itself comprise any pyrotechnic material.
[0022] While the embodiments of device 10 illustrated and described herein are of two-piece construction, it is within the scope of the present invention for device 10 to be of single-piece construction comprising a unitary body and a central, axial passageway. Such a single-piece device would retain the external configuration of housing 12 and the internal configuration of insert 14 , namely passageway 34 , described above.
[0023] As shown in FIG. 3 , energy transfer device 10 can be installed within a tool 44 , such as a firing head, for use in downhole blasting operations. Accordingly, tool 44 may be configured for attachment to a downhole pipe string or other downhole tool. Tool 44 generally comprises a firing section 46 that includes a firing head 48 equipped with a firing pin 50 . Firing section 46 further comprises a first time delay fuse 52 disposed within a bore 54 formed in the firing section. Fuse 52 generally comprises a primer 56 , one or more time delays 58 , and an output charge 60 . In certain embodiments, output charge 60 may comprise 2,2′,4,4′,6,6′-hexanitrostilbene (HNS-II). Other components that may be present within fuse 52 include one or more sections of ignition composition 62 , an ignition charge 64 , and a transfer charge 66 . Firing section 46 also includes an internally threaded end region 68 configured for attachment to an externally threaded region 70 of a tool transfer section 72 .
[0024] Energy transfer device 10 is received in region 70 . Threads 20 of device 10 are configured to mate with corresponding threads 74 of region 70 to secure device 10 therein. Device housing 12 may further include a pair of slots 76 formed in the face of forward section 16 that are configured to receive a tool used in the installation of device 10 within section 70 . A second time delay fuse 78 is received within a bore 80 formed in transfer section 72 and positioned adjacent the aft section 18 of device housing 12 . Fuse 78 may be constructed identically to fuse 52 , or it may be configured differently, such as possessing greater or fewer time delays 58 . At the end opposite from energy transfer device 10 , transfer section 72 comprises an internally threaded end region 82 that is similar in configuration to end region 68 . End region 82 is configured for attachment to an additional transfer section 72 if further overall time delay is required. Alternatively, another type of pyrotechnic charge may be coupled with end region 82 , such as the working explosive for the blasting operation.
[0025] During operation of tool 44 , firing head 48 is actuated according to any means known to those of skill in the art and results in driving firing pin 50 toward time delay fuse 52 Firing pin 50 strikes primer 56 thereby igniting fuse 52 . Combustion of the pyrotechnic material of which fuse 52 is comprised continues through output charge 60 . The detonation of output charge 60 releases heat, gas, and/or solid particulates that are directed toward the energy transfer device, and specifically the respective faces of forward sections 16 and 30 . The hot gasses generated by output charge 60 are directed through passageway forward segment 35 and exit device 10 via passageway aft segment 37 . As noted above, device insert 14 may be constructed from material that is subject to deformation by the heat and gasses released by output charge 60 , whereas housing 12 may be constructed from a material that is more resistant to being deformed by the output of fuse 52 . Accordingly, upon detonation of output charge 60 the energy, hot gas and/or solids directed toward insert 14 cause the insert forward section 30 to deform. This deformation is shown in FIG. 5 .
[0026] Particularly, the face 84 of forward section 30 , which is initially planar, deforms thereby narrowing the diameter of passageway forward segment 35 and creating a constriction 86 therein. In one exemplary embodiment, passageway forward segment 35 has an initial diameter of 0.094 inch. A typical ambient temperature time delay fuse detonating output deforms the insert material to decrease the passageway forward segment diameter to between about 0.040-0.050 inch. The output of a time delay fuse at elevated temperature produces a 25% deeper dent in a steel test dent block and also decreases the insert port diameter to 0.030-0.039 inch. The decrease in passageway open area with a time delay fuse output is between 3.5 to 9.8 times depending on the strength of the detonation. When in use and acted on by the donor detonating device (e.g., fuse 52 ), deformation/denting of insert 14 absorbs a portion of the detonation energy. The geometry and material characteristics of insert 14 cause partial closing of the passageway forward segment 35 when used in close proximity to a detonating output that is capable of denting steel. It has been discovered that strong detonations cause more deformation thereby closing the passageway forward segment 35 to a smaller diameter and further limiting the detonation impact while still allowing sufficient ignition gasses and particles to pass through. Hence this action is self-regulating pending the power output level of the donor detonating device.
[0027] The constriction 86 in passageway forward segment 35 allows pressure from output charge 60 (e.g., a combination of the detonation pressure and heat from the HNS-II, the azide output energy and the output initiator energy, hot metal fragments, molten metal and slag) to be released over a longer time. Deformation from the HNS-II creates a conical impression, which is often covered with a slag after the deformation of face 84 . Detonation of HNS-II usually only leaves black soot, thus, in certain embodiments, the observed slag on and in insert 14 indicates a flow of gasses and solids though the passageway 34 after the initial impact from detonation.
[0028] The two-part construction of device 10 permits housing 12 to be reused by simply replacing insert 14 . Passageway aft segment 37 can have a larger initial diameter than passageway forward segment 35 . The larger-diameter segment 37 functions as a renewable passage to ensure tool wear does not affect performance and to ensure the diameter and concentricity are controlled. It is noted that the area nearest to the input of the next delay usually expands also and would be a wear point if it were part of the re-useable tooling.
[0029] The energy, gas and/or solid products generated by combustion of output charge 60 are then carried through passageway 34 toward fuse 78 . Upon reacting aft face 88 of insert 14 , the hot gas and/or solids are focused directly on the primer 56 of fuse 78 and ensure ignition thereof Thus, device 10 effectively and reliably transfers the output of fuse 52 to fuse 78 and ensures that the firing sequence, which began with firing head 48 , continues. The output charge 60 of fuse 78 may then be transferred to another fuse through attachment of another transfer section 72 to end region 82 , or to another type of pyrotechnic device such as another firing head or an explosive charge that might be used in the blasting operation.
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A energy transfer device ( 10 ) is provided that is capable of transferring the energy output from one pyrotechnic device ( 52 ) to another device ( 78 ) for initiating firing thereof. Device ( 10 ) comprises a device housing ( 12 ) in which a deformable device insert ( 14 ) is received. Device insert ( 14 ) comprises a central passageway ( 34 ) for transmitting the output from a pyrotechnic device ( 52 ), including energy, gasses, and/or solids, to another pyrotechnic device ( 78 ). The passageway ( 34 ) conducts the pyrotechnic device output to a precise location on the second pyrotechnic device ( 78 ) where firing is most effectively initiated. The energy transfer device ( 10 ) may be employed as a part of a tool ( 44 ) used in well completion operations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stitch pattern sewing machine and, more specifically, to a stitch pattern sewing machine capable of sewing original patterns in different sizes.
2. Description of the Related Art
Some conventional stitch pattern sewing machines capable of sewing a plurality of patterns including characters and symbols allow the selection of a desired pattern through the operation of numeric keys and the optional selection of a pattern size for the selected pattern. Generally, each pattern has a predetermined standard size which can be changed within a predetermined range by manually operating a switch or the like. The conventional stitch pattern sewing machine of the type described stores data of a plurality of needle locations to control the needle for pattern sewing. In sewing a selected pattern in a selected pattern size, the distance between the adjacent needle locations is increased or decreased according to the selected pattern size. Some conventional sewing machines store pattern data for a multiple overlap stitch, namely, data for forming multiple stitches between two needle locations.
However, a problem arises in enlarging or reducing the original pattern; that is, since the original pattern is designed with reference to a standard pattern size, the image of an enlarged or reduced stitch pattern differs from that of the corresponding original pattern. This is because the apparent thickness of lines delineating the stitch pattern relative to the pattern size decreases and hence the stitch pattern looks lean when the original pattern is enlarged. On the other hand, the apparent thickness of lines delineating the stitch pattern relative to the pattern size increases and details of the pattern cannot be expressed clearly when the original pattern is reduced. Furthermore, when the original pattern is reduced, stitches are liable to interfere with each other because the distance between the adjacent needle locations is decreased.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a stitch pattern sewing machine capable of sewing attractive stitch patterns regardless of the sizes of the patterns.
The above object can be achieved, according to the present invention, by a stitch pattern sewing machine comprising:
pattern storage means for storing patterns to be formed on a workpiece;
pattern selecting means for selecting a pattern stored in the pattern storage means;
size setting means for setting a size of the pattern selected by the pattern selecting means;
multiple overlap stitch setting means for setting the number of overlap stitches based on the size of the pattern set by the size setting means; and
stitch forming means for forming a stitch pattern corresponding to the pattern selected by the pattern selecting means based on the size of the pattern set by the size setting means and the number of overlap stitches set by the multiple overlap stitch setting means.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of a stitch pattern sewing machine in a preferred embodiment according to the present invention;
FIG. 2 is a block diagram of an electrical system included in the stitch pattern sewing machine of FIG. 1; and
FIGS. 3(a) and 3(b) are flow charts of a stitch mode selecting routine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A stitch pattern sewing machine embodying the present invention has a main frame 70 provided with a start-stop switch 21, a pattern selecting unit 22 comprising numeric keys, an enlargement switch 23 for setting a desired enlargement ratio at which a selected pattern is enlarged, a reduction switch 24 for setting a desired reduction ratio at which a selected pattern is reduced, and a display 51 for displaying the type and size of a selected pattern. A needle bar 61 fixedly holding a needle at its lower end is supported for vertical movement on the head section 71 of the frame 70. The needle bar 61 is driven for vertical reciprocation through a needle bar driving mechanism by a main motor 31 and is driven for swing motion through a needle bar swinging mechanism by a swing motor 35, which will be described afterward. A feed dog 62 is supported for vertical and lengthwise movement on a bed 72. The feed dog 62 is driven for vertical movement through a feed lifting rock mechanism by the main motor 31, and is driven for lengthwise movement through a lengthwise feed mechanism by a feed motor 33. The respective mechanical constructions of the main motor 31, the feed motor 33, the swing motor 35, the needle bar driving mechanism, the needle bar swinging mechanism, the feed lifting rock mechanism and the lengthwise feed mechanism may be of the types disclosed in U.S. Pat. No. 4,823,715.
The electrical configuration of the stitch pattern sewing machine will be described hereinafter. Referring to FIG. 2, the stitch pattern sewing machine is provided with an electronic controller 10 which controls the general sewing operation, a sewing condition setting unit 20, a driving unit 30 which drives the sewing mechanism, a timing pulse generator 40 which generates a timing signal according to the operation of the sewing mechanism, and a display unit 50 which displays sewing information including a pattern selected by operating the switch unit 20 and a selected pattern size.
The electronic controller 10 comprises a known CPU 11, a ROM 12, a RAM 13, an I/0 interface 14 which converts input signals given from external devices to the CPU 11 into signals for processing by the CPU 11, and a bus 15 interconnecting the CPU 11, the ROM 12 and the RAM 13.
The ROM 12 stores a plurality of pattern data specifying needle positions (positions of the needle on a workpiece) for characters, symbols and patterns, a control program for controlling the driving unit 30 according to commands given by operating the switch unit 20, a control program for controlling the display unit 50 and a control program for controlling the stitch mode selecting operation. Each of the plurality of pattern data includes two stitch data respectively for a single stitch mode and a triple stitch mode. In the triple stitch mode, three stitches are formed between two adjacent needle positions.
The RAM 13 includes an address pointer for specifying the respective addresses of pattern data, a memory for storing pattern data specified by the address pointer, flags, a stitching cycle counter, and a buffer memory for temporarily storing the results of operation of the CPU 11.
The switch unit 20 which gives signals to the I/0 interface 14 of the electronic controller 10 comprises the start-stop switch 21, the pattern selecting unit 22 comprising the numeric keys which are operated to enter a number of two figures representing a pattern to select a desired pattern, the enlargement switch 23, and the reduction switch 24. The standard pattern size, i.e., the default pattern size stored in the ROM 12, of a pattern is enlarged or reduced by one degree every time the pushbutton of the enlargement switch 23 or the pushbutton of the reduction switch 24 is pushed. Thus, a desired pattern size is determined by pushing the pushbutton of the enlargement switch 23 or that of the reduction switch 24 a corresponding number of times. In this embodiment, the pattern width can be changed stepwise in the range of 3 mm to 9 mm in a 0.5 mm step.
The driving unit 30 comprises the main motor 31, a sewing motor driving circuit 32 for driving the main motor 31, the feed motor 33, a feed motor driving circuit 34 for driving the feed motor 33, the swing motor 35 for swinging the needle bar 61 in directions perpendicular to the feed direction in which the workpiece is fed, and a swing motor driving circuit 36 for driving the swing motor 35. The driving circuits 32, 34 and 36 are connected to the I/0 interface 14 of the electronic controller 10 to drive the motors 31, 33 and 35, respectively, according to control signals given thereto by the electronic controller 10.
The timing pulse generator 40 comprises a disk attached to the main shaft of the stitch pattern sewing machine, and a photointerrupter. The timing pulse generator 40 generates a timing pulse signal synchronously with the rotation of the main shaft every turn of the main shaft through a predetermined angle, and gives the timing pulse signal to the electronic controller 10. The driving circuits 34 and 36 control the feed motor 33 and the swing motor 35, respectively, on the basis of the timing pulse signal.
The display unit 50 comprises the display 51 which displays pattern information including the type and size of a selected pattern in a liquid crystal dot matrix, and a display driving circuit 52 for driving the display 51 according to signals provided by the electronic controller 10.
A stitch mode selecting operation to be executed by the electronic controller 10 will be described with reference to a flow chart of a stitch mode selecting routine shown in FIGS. 3(a) and 3(b). The stitch mode selecting routine is repeated at predetermined time intervals.
In step 100, a query is made to see if a pattern is selected. A pattern is selected by entering a pattern number of two figures specifying the pattern by operating the pattern selecting switch unit 22. When the response in step 100 is affirmative, namely, when a pattern number is entered, the pattern number is stored in the register A of the RAM 13 in step 110. Subsequently, the default pattern size of the pattern stored previously in the ROM 12 is transferred to the register B of the RAM 13 in step 120, and the stitching cycle counter of the RAM 13 for counting the number of stitching cycles of the needle is cleared in step 130 before starting the sewing operation.
After steps 100 to 130 have been executed, a query is made in step 140 to see if the enlargement switch 23 is operated. When the response in step 140 is affirmative, the enlarged pattern size indicated by operation of switch 23 is stored in register B in step 145. Next, a query is made in step 150 to see if the pattern size specified by operating the enlargement switch 23 and stored in register B is within a predetermined range, for example, the range of 3 mm to 9 mm. When the response in step 150 is affirmative, the stitching cycle counter of the RAM 13 is cleared in step 170. If the response in step 150 is negative, e.g., due to excessive operation of switch 23, a maximum pattern size is stored in register B in place of the previously stored out of range value in step 160 and processing proceeds to step 170.
After steps 140 to 170 have been executed, steps 180 to 210 are executed. Steps 180 to 210 are similar to steps 140 to 170, except that the condition of the reduction switch 24 is examined instead of that of the enlargement switch 23. When a reduced pattern size specified by operating the reduction switch 24 in step 180 and stored in register B in step 185 is within the predetermined range (step 190), the the stitching cycle counter is cleared in step 210. When the specified pattern size is outside the predetermined range, a minimum pattern size is stored in register B in place of the out of range value in step 200 and processing proceeds to step 210.
Subsequently, a query is made in step 220 to see if the specified pattern size is greater than a reference pattern size stored previously in the ROM 12. The triple stitch data stored in the ROM 12 is set in step 230 when the response in step 220 is affirmative or the single stitch data stored in the ROM 12 is set when the response in step 220 is negative, and then routine goes to RETURN to end the routine. The pattern data is set by transferring the top address in the ROM 12 where the pattern data is stored to the register C of the RAM 13. In this embodiment, the default pattern size, i.e., the default pattern width, is 6 mm. The triple stitch data is set when the pattern size specified by operating the enlargement switch 23 or the reduction switch 24 is in the range of 6 mm to 9 mm or the single stitch data is set when the specified pattern size is in the range of 3 mm To 5.5 mm. Therefore the reference pattern size is 5.5 mm.
Thus, the foregoing stitch mode selecting procedure stores a default pattern size in the register B of the RAM 13, and a pattern size specified by operating the enlargement switch 23 or the reduction switch 24 is stored in the register B of the RAM 13 when the enlargement switch 23 or the reduction switch 24 is operated. In case the pushbutton of the enlargement switch 23 or the reduction switch 24 is pushed an excessive number of times, the maximum pattern size (9 mm) or the minimum pattern size (3 mm) is selected.
After the stitch mode, i.e., the single stitch mode or the triple stitch mode, has been specified, the start-stop switch 21 is operated to provide a start signal for starting a sewing operation control routine (not shown). Then, pattern data is outputted from the ROM 12 based on the contents of registers A, C. The pattern data outputted from the ROM 12 is adjusted by being multiplied by a ratio of the specified pattern size stored in the register B to the default pattern size. The pattern is formed based on the adjusted pattern data in the enlarged or reduced size. A display control routine, not shown, controls the display driving circuit 52 of the display unit 50 on the basis of data stored in the registers A, B and C of the RAM 13 to display the selected pattern and its specified pattern size on the display 51.
Thus, the stitch pattern sewing machine sets the triple stitch mode when the specified pattern size is greater than a given reference pattern size or the single stitch mode when the specified pattern size is equal to or smaller than the given reference pattern size. Accordingly, the thickness of stitch lines forming the pattern is agreeable to the pattern size, so that the stitch pattern is very attractive and stitches are not crowded excessively even in sewing a pattern in a reduced pattern size.
The following is a description of modified embodiments of the present invention.
The stitch modes may include, in addition to the foregoing single stitch mode and the triple stitch mode, a five-fold overlap stitch mode and a seven-fold overlap stitch mode.
Even if the triple stitch mode is selected initially, all the portions of the pattern need not be sewn in the triple stitch mode; the stitch mode may be changed for a portion of the pattern to the single stitch mode, a double stitch mode and/or a quadruple stitch mode if desired. Pattern data may be provided in ROM 12 providing different stitch modes for different portions of the pattern based on the selected pattern size. For example, upon enlargement of a pattern, multiple stitch pattern data comprising data for producing both multiple overlap stitches and single stitches within a pattern may be selected.
Although the stitch pattern sewing machine in the foregoing embodiment is provided with individual pattern data respectively for the single stitch mode and the triple stitch mode, the stitch pattern sewing machine may be provided with only the pattern data for the single stitch mode to reduce the quantity of data to be stored in the ROM 12, and pattern data for a multiple overlap stitch mode may be produced by processing the pattern data for the single stitch mode.
Furthermore, although the stitch pattern sewing machine in the foregoing embodiment forms a pattern by a combined effect of feeding the workpiece in the lengthwise directions and swinging the needle bar in directions perpendicular to the lengthwise directions, a stitch pattern sewing machine in accordance with the present invention may employ a pattern forming system which drives the feed dog for movement in both lengthwise and lateral directions or a pattern forming system which moves an embroidery frame holding a workpiece in lengthwise and lateral directions.
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A stitch pattern sewing machine includes a ROM for storing triple stitch pattern data for a large size pattern and single stitch pattern data for a small size pattern for each pattern of a plurality of patterns, a pattern selecting unit for selecting one of the patterns, an enlargement switch for enlarging a size of the pattern selected by the pattern selecting unit, a reduction switch for reducing the size of the pattern selected by the pattern selecting unit, a CPU, and a driving unit for forming a stitch. The CPU selects one of the triple stitch pattern data and the single stitch data based on size of the pattern. The CPU controls the driving unit based on the selected pattern data and size of the pattern. As a result, stitch thickness can be varied with pattern size to maintain a desired appearance.
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TECHNICAL FIELD
[0001] The invention herein resides in the art of decorating accessories of the type that may be placed on a table, hung on a wall, displayed on an easel and the like. Particularly, the invention relates to decorative plaques of the type that may contain photographs, illustrations, motivational or inspirational messages, scripture and the like. Specifically, the invention relates to a decorative plaque assembled from a plurality of interconnected tiles, the tiles and connective devices employed allowing for the configuration of the plaque in any of various geometries, while further accommodating the disassembly and reconfiguration of the plaque in a different geometry.
BACKGROUND ART
[0002] The use of decorative plaques to accessorize a room setting has become commonplace. Such plaques often provide a means for displaying pictures or photographs, decorative illustrations, motivational or inspirational sayings, scriptures, and the like. Presently known plaques are of a fixed configuration and structure. Typically, the plaques are of a unitary and integral one-piece construction, being inflexible as to the specific nature of the display offered by the plaque. Such plaques are not given to accommodating the rearrangement of a room with regard to furniture placement, wall-hanging placement, and the like. Moreover, such plaques, being of a fixed nature, take on a familiar or “old” appearance over time. Additionally, such known plaques are not given to personalization of expression. The purchaser must necessarily find a plaque to his or her liking, or as near thereto as possible, while such do not accommodate the construction of a plaque by the end user in order to satisfy his or her specific needs and desires.
[0003] There is a need in the art for decorative plaques that are configurable and reconfigurable by the end user.
SUMMARY OF THE INVENTION
[0004] In light of the foregoing, it is a first aspect of the invention to provide reconfigurable decorative plaques that allow the end user to significantly impact the final appearance of the plaques.
[0005] A further aspect of the invention is the provision of reconfigurable decorative plaques that allow the user to change the appearance of the plaques with or without additional purchases.
[0006] Still another aspect of the invention is the provision of reconfigurable decorative plaques that allow the interchanging of plaque portions among different plaques.
[0007] Yet another aspect of the invention is the provision of reconfigurable decorative plaques that are of structural integrity once assembled, and yet readily disassembled for purposes of reconfiguration.
[0008] Still a further aspect of the invention is the provision of reconfigurable decorative plaques that accommodate various geometric configurations of the plaque, such as accommodating horizontal or vertical display with the same constituent elements.
[0009] Still another aspect of the invention is the provision of reconfigurable decorative plaques that are easy to use, manipulate, interconnect and change in a cost-effective manner.
[0010] The foregoing and other aspects of the invention that will become apparent as the detailed description proceeds are achieved by a decorative plaque, comprising: a plurality of tiles releasably, selectively, and interchangeably interconnectable with each other; and at least one removable and replaceable connector interconnecting adjacent tiles and thereby forming the plaque.
DESCRIPTION OF DRAWINGS
[0011] For a complete understanding of the various objects, techniques and structures of the invention, reference should be made to the following detailed description and accompanying drawings wherein:
[0012] FIG. 1 is a front plan view of a decorative plaque made in accordance with the invention in a first arrangement;
[0013] FIG. 2 is a back plan view of the decorative plaque of FIG. 1 ;
[0014] FIG. 3 is a front plan view of a decorative plaque using the constituent elements of that of FIG. 1 , but in a different arrangement; and
[0015] FIG. 4 is a back plan view of the decorative plaque of FIG. 3 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] Referring now to the drawings and more particularly FIG. 1 , it can be seen that a first embodiment of a plaque made in accordance with the invention is designated generally by the numeral 10 . The plaque 10 of this arrangement consists of square tiles 12 , 14 interconnected with each other and with a rectangular tile 16 . The tiles 12 , 14 , 16 may be made of any suitable material, such as wood, plastic, fiberboard, mica board, or the like. As shown, the tile 12 has a picture aperture 18 therein, providing a picture frame for receipt of a photograph or the like. The face A of the tile 12 may contain decorative material such as illustrations, sayings, quotations, scriptures, and the like. Similar decorative-type materials can appear on the face B of the tile 14 and the face C of the tile 16 .
[0017] It will be appreciated that the plaque 10 may be of any of various geometric configurations as can the individual tiles 12 , 14 , 16 . In the embodiment of FIG. 1 , the tiles 12 , 14 are square, having a side dimension that is one-half the length of the rectangular tile 16 , and with the width of the tile 16 being the same dimension as a side of the square tiles 12 , 14 . The resultant assembly of the plaque 10 is that of a square plaque having four times the area and double the perimeter of one of the tiles 12 , 14 .
[0018] With reference now to FIG. 2 , an appreciation can be obtained of the structure and methodology employed for interconnecting the tiles 12 , 14 , 16 . As shown, the backs of the tiles contain recessed regions 20 uniformly spaced about the peripheries of the tiles 12 , 14 , 16 . These recessed regions are, in a preferred embodiment, of a truncated triangular shape, as shown. The narrow portions 22 of the recessed regions 20 are positioned at the edges of the associated tiles. The larger portion 24 of the recessed regions 20 is distal from the edge toward the interior of the tile, as shown. It will be appreciated that the recessed regions 20 are characterized by rounded corners 26 to accommodate the removal of connectors 28 received in paired recessed regions 20 . As shown, the connectors 28 are configured as the aligned recessed regions 20 in abutting tiles 10 , 12 , 14 . The connectors extend from a center necked-down region to expanded ends corresponding to the cavity defined by paired and opposed recessed regions 20 . The connectors 28 are generally of a “butterfly” configuration.
[0019] The connectors 28 have sharp corners 30 , leaving space in the recessed rounded corners 26 of the recessed regions 20 . In FIG. 2 , the connectors 28 are shown as received within the cavities defined by the paired and opposed recessed regions 20 . The connectors 28 have a thickness that corresponds to the depth of the receiving cavity, and the perimeter of the connector 28 is slightly larger than the perimeter of the cavity defined by mating recesses 20 , such that the connectors 28 are received therein by a press, interference, or friction fit. To accommodate the insertion of the connectors 28 , the bottom peripheral edges (not shown) of the connectors 28 may have a slight bevel to facilitate placement. It will be appreciated that the connectors 28 may have a perimeter that is slightly greater than that of the recess 20 about the entirety thereof, or just at selected areas to accommodate the friction fit.
[0020] No glue or adhesive is used between the connector 28 and its receiving cavity. Accordingly, the connector 28 may be removed for purposes of reconfiguration of the resultant plaque. Once reconfigured, the connectors 28 may be placed in the corresponding aligned recessed regions 20 , forming appropriate cavities. The area between the sharp corners 30 of the connectors 28 and the rounded corners 26 thereof, allows for the insertion of a tool, such as a small screwdriver blade, knifepoint, or the like to pry or otherwise urge the connector 28 from the cavity of the recesses 20 .
[0021] With continued reference to FIG. 2 , it can be seen that a clamp 32 is provided to be received by peripheral recess 34 defined about the picture aperture 18 . Again, the clamp 32 is received in the peripheral recess by an appropriate press, interference, or friction fit, and rounded corners 36 are again provided to accommodate access to the corners of the clamp 32 for removal thereof. The clamp 32 provides a means for holding a picture, illustration, or the like in the aperture 18 .
[0022] As further shown in FIG. 2 , hanger slots 38 are centrally positioned toward an edge of the associated tiles to accommodate hanging on a nail, screw head, or the like. In that regard, hanger slots 38 are preferably of a key slot configuration and are undercut for the purpose of receiving the hanger head.
[0023] With reference now to FIG. 3 , it can be seen that a plaque 40 of alternate configuration from the plaque 10 may be made using the same tiles 12 , 14 , 16 as were used for forming the plaque 10 . The back of the plaque 10 is shown in FIG. 4 , where it can be appreciated that the connectors 28 are now used to interconnect the various tiles in an aligned rectangular configuration with the hanger slot 38 of the tile 14 providing for vertical hanging. In this arrangement, the plaque 40 again has 4 times the area of a single square tile 12 , 14 , and a perimeter 2.5 times thereof.
[0024] By uniformly positioning the recessed regions 20 about the perimeters of the various tiles and the positioning of appropriate hanger slots 38 centrally of intended “top” edges of the tiles, and by employing a press fit rather than a glued or permanent joint, the reconfiguration demonstrated above can be achieved. Not only can the same tiles be used, but other tiles can be interjected in various combinations and permutations in order to achieve any of numerous geometric configurations for the resulting plaque.
[0025] Thus, it can be seen that the various aspects of the invention have been achieved by the structures and techniques presented above. While in accordance with the patent statutes, only the best mode and preferred embodiments of the invention have been presented and described in detail, the invention is not limited thereto or thereby. Accordingly, for an appreciation of the true scope and breadth of the invention, reference should be made to the following claims.
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Decorative plaques are achieved by various interconnections of independent tiles. The tiles are configured with connector regions uniformly spaced about the peripheries thereof such that they align with the joint regions of other tiles in various end configurations. A friction-fit connector is used to interconnect the tiles at the paired recessed regions. No glue or permanent interconnection media is used, such that the connectors can be removed and the uniformity of the tiles accommodates repositioning and reorientation to achieve a plaque of a new or different configuration, as desired.
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FIELD OF THE INVENTION
The present invention relates to apparatus for removing bubbles of a gas and/or dissolved gas from a liquid. Such apparatus is herein referred to as "debubbling apparatus".
BACKGROUND OF THE INVENTION
Such debubbling apparatus finds application, for example, in the manufacture of photographic materials, for removing bubbles from liquid photographic emulsion prior to application of such emulsion to a supporting substrate such as paper or plastics film and drying of the emulsion. The invention may also have utility in the food processing industries or in confectionery manufacture, where air bubbles are undesirable because they may harbour germs, or in blood transfusion apparatus, where air bubbles present a potentially lethal hazard.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved debubbling apparatus.
According to one aspect of the present invention, there is provided debubbling apparatus comprising a vessel having an inlet and an outlet spaced apart longitudinally of the vessel, and means for transmitting a beam of ultrasound along a longitudinal axis of the vessel in a direction away from said outlet end and towards the opposite end, and means for maintaining said vessel under positive pressure.
According to another aspect of the present invention, there is provided a method of debubbling a liquid comprising passing the liquid through a vessel from an inlet to an outlet spaced apart longitudinally of the vessel, transmitting a beam of ultrasound along a longitudinal axis of the vessel in a direction away from said outlet and towards said inlet and thereby propelling longitudinally through the vessel, by means of the ultrasonic wind effect, bubbles present in said liquid.
In a preferred embodiment, the debubbling apparatus comprises a vessel having substantial rotational symmetry about a vertical axis, an inlet conduit providing an inlet passage communicating with the interior of said vessel adjacent an upper end thereof and aligned along an axis extending transversely with respect to said vertical axis of the vessel and passing on one side of said vertical axis, whereby the supply of liquid to said vessel via said inlet at a substantial velocity will induce spin of the liquid in the vessel in a predetermined rotational sense about said vertical axis, an outlet for liquid from said vessel communicating with the interior of said vessel via an outlet port in the wall of said vessel adjacent a lower end thereof, a further outlet from said vessel at or adjacent the upper end of the vessel to receive gas, or liquid containing gas bubbles, discharged upwardly through the liquid in said vessel along or close to said vertical axis, and an ultrasonic transmitter mounted in the lower end of said vessel and adapted to transmit ultrasonic energy axially upwardly in said vessel, through liquid in said vessel, towards said further outlet.
The apparatus of the invention makes use of the "ultrasonic wind" effect, a known effect in accordance with which bubbles in a liquid are propelled along an ultrasonic beam in a liquid, away from the source of such beam. The swirl imparted to the liquid within the vessel by the offsetting of the inlet tends to displace any bubbles within the vessel towards the axis of the vessel where they are rapidly conveyed, by the "ultrasonic wind" towards said further outlet. In operation of the apparatus, liquid containing any such bubbles conveyed to said further outlet by the "ultrasonic wind" is withdrawn from the vessel via said further outlet and the liquid withdrawn from the vessel via the outlet at the bottom of the vessel is substantially bubble-free.
The "ultrasonic wind" effect is not dependent on gravity and experiments have established that the apparatus of the invention, once operation has been established, will continue to operate with quite radical departures of the axis of rotational symmetry of the vessel from verticality, and even with such axis horizontal or with the apparatus inverted. However, because the most convenient starting conditions can generally only conveniently be obtained with said axis of rotational symmetry at least approximately vertical, the term "vertical" is used herein but it should be appreciated that it is not used in any strict sense.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference will now be made, by way of example only, to the accompanying drawings in which:
FIG. 1 is a schematic view partly in side elevation and partly in axial section of an apparatus embodying the invention;
FIG. 2 is a schematic plan view of the apparatus of FIG. 1;
FIG. 3 is a graph of electrical power supplied against maximum working liquid flow rate for an embodiment of the invention;
FIG. 4 is a graph of electrical power supplied against air entrainment for satisfactory operation of the same embodiment; and
FIG. 5 is a graph of maximum working flow rate against viscosity for the same embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, the apparatus comprises a generally cylindrical vessel 10 arranged with its longitudinal axis vertical, the vessel being closed at the top and bottom by respective upper and lower end walls 12, 14. A horizontal inlet pipe or conduit 16 extends chordally and, in the arrangement shown in FIG. 2, substantially tangentially with respect to the cylindrical wall of the vessel and meets that wall in an inlet port. Thus, the longitudinal axis of the inlet conduit 16 is substantially offset laterally with respect to the vertical central axis of the vessel 10. A horizontal outlet conduit 18 extends from an outlet port at the bottom of the cylindrical wall of the vessel, the outlet conduit being likewise disposed chordally or tangentially with respect to the cylindrical vessel 10. It will be appreciated that, with the arrangement illustrated in FIG. 2, the supply of liquid to the vessel 10 via the inlet conduit 16 at any appreciable rate, will result in the liquid within the vessel having a spin imparted thereto which is clockwise about the vertical axis as viewed in FIG. 2. That is to say, given a net flow from the inlet 16 to outlet 18 through the vessel, the liquid proceeds in a spiralling movement from the upper to the lower end of the vessel. As illustrated, the disposition of the outlet conduit 18 with respect to the spin induced by the supply of liquid via the inlet conduit 16 is such that the liquid in the vessel in the region of the outlet port has a substantial component of motion along the axis of the outlet conduit in the direction of the discharge through the outlet conduit and thus tends to maintain the spin of liquid within the vessel. However, the orientation of outlet 18 is not of great importance and it may extend radially or in any other direction.
A device 19 is provided for propagating an ultrasonic beam axially within the vessel 10. The device comprises a transducer portion, indicated generally at 20, outside the vessel 10, below end wall 14 and an ultrasound-conducting and propagating member 22 of solid cylindrical form in the present embodiment but referred to herein, for convenience, as a "horn", extending axially within the vessel from the bottom end wall 14.
The horn may, for example, comprise a cylindrical metal bar of predetermined length having a flat upper end face perpendicular to the common axis of horn 22 and vessel 10. The horn 22 has a screw-threaded axial passage (not shown) extending from its lower end and receiving a securing bolt 24 (the head of which is visible in FIG. 1), passed through a central hole in the lower end wall, and passing through an axial passage provided in the stack of components forming the transducer portion 20. The bottom end wall 14 is thus clamped, by the bolt 24, between the lower end face of the horn 22 and the transducer portion 20, whereby the aperture in the end wall 14 is sealed against passage of liquid or air and the device 19 is mechanically secured to the end wall 14.
The transducer 20 is based upon the Langevin sandwich, known per se and comprises a first annular end mass 26 below the lower end wall 14, a first annular piezo-electric crystal 28 below end mass 26, an annular contact plate 32 disposed between the crystal 28 and a second annular piezo electric crystal 30 matched with crystal 28 and a second annular end mass 34 disposed below crystal 30 and above the head of the bolt 24. The contact plate 32 is electrically connected with an ultrasonic signal generator (not shown) providing an a.c. electrical signal (e.g. of 40 kHz).
The horn 22 and the components of the transducer portion 20 are selected and dimensioned, in manner known per se, to afford efficient conversion of electrical energy supplied to the transducer portion 20 to ultrasonic energy propagated upwardly, axially in the vessel 10 from the flat upper end face of the horn 22, at the selected ultrasonic operating frequency of the device (preferably, as noted above, around 40 kHz). The end wall 14 is constructed as a flexible metal diaphragm to accommodate ultrasonic vibrations in the vertical sense imparted to the lower face of horn 22, and thus to the central portion of wall 14, by the transducer portion 20. A vent conduit 44 extends axially from a vent outlet located centrally in the top end wall 12 of the vessel.
In operation of the apparatus, liquid to be debubbled is supplied to the vessel via the inlet conduit 16 from a supply vessel (not shown) and liquid containing entrained air bubbles is drawn from the vessel via the vent conduit 44 and returned (recycled) to the supply vessel, whilst debubbled liquid is discharged from the outlet conduit 18.
In one embodiment of the invention, designed to operate at a frequency of 40 kHz, the vessel 10 may have an internal diameter of 7.5 cm and an axial length of 42.5 cm with a horn 22 of stainless steel of an axial length of 19 cm and diameter of 4 cm. The length of the vessel 10 is not critical, provided it is at least the length of the horn plus several wavelengths of the ultrasound in the liquid concerned.
The device is operated with a minimum pressure of 20.7 kPa (3 psi) in the vessel 10, but it has been found that the performance of the device, in terms of its capacity to debubble liquid with large amounts of entrained air at large liquid flow rates, improves with increased pressurisation, and pressures as high as 0.31 MPa (45 psi) have been employed successfully. The action of the ultrasonic energy propagated through the vessel above the upper end face of horn 22 is to break up any larger bubbles which may enter via inlet 16 and to propel the resulting smaller bubbles upwardly by virtue of the "ultrasonic wind" effect noted above.
The spiral movement of the liquid within the vessel 10 is all-important because it disciplines the bubble path. Experiments have established that without such spiral movement, (engendered in the preferred embodiment by the tangential entry of liquid into and exit of liquid from the vessel), a cloud of bubbles forms right across the cross section of the vessel and prevents the "wind" bubbles from the horn from escaping freely up and out of the vent 44. If this happens the device very quickly fails catastrophically because ultrasound will not transmit through a blanket of air bubbles.
The flow rate from the vessel 10 through the vent conduit 44 need simply be enough to carry away all the bubbles. With a device of the dimension exemplified above, a flow rate of 0.21/min to 11/min has been found to be more than adequate. The applicants have found that, for proper operation, the vessel 10 must, at start-up, be completely free of bubbles below the level of the upper end of the horn 22. Thus, start procedure is important. Where, as indicated above, the liquid with entrained bubbles extracted from the vessel 10 is recycled to the supply vessel, provision must be made for the removal of such bubbles before the liquid is returned to the vessel 10, for example by allowing time for such bubbles to separate from the liquid. In the absence of such provision the bubbles will return to the vessel 10 and eventually choke the system.
The apparatus described makes use of the so-called "wind", which is created by an ultrasonic transducer cavitating in a liquid, to propel bubbles to the top of the vessel 10, where the vent pipe 44 allows bubbles to be continuously removed. For the purpose required, the apparatus with its cylindrical vessel 10 and coaxial transducer, with a distance of several wavelengths (at 40 kHz in liquid) in front of the face of the "horn", appears to be the ideal design.
When operated correctly and within its limits, the apparatus described will let no bubbles at all pass downwardly past the upper end of the horn 22. Experiments have confirmed that the limiting factor in performance of the apparatus is when the liquid flow rate through it causes a linear downward liquid velocity which overpowers the upward velocity of the bubbles due to the ultrasonic "wind", so that bubbles reach the region between the wall of vessel 10 and the side of horn 22, below the upper end face of the horn. In practice, it has been found that the apparatus can handle surprisingly high flow rates (via inlet 16 and outlet 18) before this limiting condition is reached. It is believed that this is, at least in part, because higher flow rates produce faster swirl within the vessel and thus increased centrifugal force so that bubbles entering with the liquid via inlet 16 are more rapidly delivered to the region adjacent the axis of the vessel 10 where the effect of the "ultrasonic wind" and of the removal of liquid via outlet 44 are greatest and where any downward component of liquid velocity is least.
Besides its effectiveness in eliminating bubbles, the apparatus described has been found to be capable of debubbling liquid at flow rates which are substantially higher, in relation to the volume of the vessel 10, than known debubbling apparatus and yet with a power expenditure substantially less than known apparatus of comparable capacity. The low volume of the vessel is advantageous in photographic emulsion coating systems in particular, because such coating is carried out on a batch basis and it is necessary to wash out and purge such systems between batches and also when faults occur. The volume of any debubbling apparatus must be included in the volume of emulsion lost (i.e. rendered unusable without further processing or recycling) so that the small volume of the debubbling apparatus of the invention allows substantial savings to be effected.
The three graphs of FIG. 3, FIG. 4 and FIG. 5 are a selection from a whole family of curves and show the working limit of the apparatus in each case. FIG. 3 shows how at a fixed viscosity and vessel pressure and air entrainment rate (air injection rate), the maximum working flow rate possible is virtually independent of power supplied to the transducer. FIG. 4 shows how for a given viscosity, flow rate and operating pressure, a certain minimum power is required for the apparatus to work and that more power is required with an increasing percentage of air entrainment. The minimum power required in FIG. 4 is the level at which cavitation starts in the solution of viscosity 318 centipoise being used in the test. For a viscosity of 10 centipoise, this minimum level drops to around 10 W. FIG. 5 shows how the maximum working flow rate varies only slightly with viscosity.
Whilst, in the preferred embodiment described with reference to the drawings, a further outlet 44 is provided at the upper end of the vessel, centred on the vertical longitudinal axis of the vessel, in some embodiments no such further outlet may be provided, the air in the bubbles propelled upwardly by the ultrasonic wind merely being allowed to accumulate in the upper end of the vessel. Such an arrangement is practicable in short batch production runs where the amount of air so accumulating in a single run will not be sufficient to reduce to dangerously low levels the depth of liquid above the horn 22. At the end of the production run, the accumulated air may be removed by reverse flow of liquid through the vessel and the connected parts of the system.
Likewise a further outlet for air need not be disposed on the axis of the vessel if some air space above the liquid in the vessel can be tolerated, but such further outlet, for removal of air without liquid, may extend from the peripheral wall of the vessel adjacent the upper end of the vessel.
Furthermore, it is not essential, in every case, to impart spin or a spiralling motion to liquid within the vessel, particularly if liquid flow rate and the amount of entrained air are small, since in such a case there may not be enough bubbles at any time to form a dense cloud which would impede transmission of the ultrasound.
As noted above, the longitudinal axis of the vessel need not be strictly vertical and, indeed, the starting and running requirement that there should be no bubbles in the region between the side of the horn and the side of the vessel can be met by an arrangement in which the axis of the vessel is inclined only slightly upwardly from the outlet end to the inlet end although in such an arrangement it is preferred that the inlet port should be lowermost.
The vessel 10 need not be in the form of a straight cylinder but may, for example, diverge conically from its upper end or may comprise an upper cylindrical section of smaller diameter, an intermediate downwardly diverging section and a lower cylindrical section of greater diameter, for example extending over the length of the horn. The last noted arrangement may be useful in counteracting the restriction of the flow cross-section of the vessel caused by the presence of the horn, and which, by reducing pressure, may tend to produce bubbles in the region between the side of the horn and the wall of the vessel by bringing air out of solution.
In general, the flow capacity of the apparatus may be increased by increasing the diameter, but such increase, which may also necessitate an increase in height in order to ensure that the ultrasonic beam fills the cross-section of the vessel over an adequate column of the liquid so that there is a liquid wastage penalty attached to such increase in flow capacity, at least where the apparatus is used for de-bubbling photographic emulsion.
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Debubbling apparatus may have many uses, for example, in the manufacture of photographic materials where bubbles are to be removed from liquid photographic emulsion prior to application of such emulsion to a supporting substrate, in the food processing industries or in confectionery manufacture where air bubbles are undesirable because they may harbour germs, or in blood transfusion apparatus where air bubbles present a potentially lethal hazard. Described herein is a debubbling apparatus which comprises a vessel having an outlet and an inlet spaced from one another longitudinally of the vessel, means for imparting rotational movement, about a longitudinal axis of the vessel to liquid passed through said vessel from said inlet to said outlet, and means for transmitting a beam of ultrasound along the axis of said vessel in the direction towards said inlet, from a location closer to said outlet than to said inlet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for forming a semiconductor light-emitting device, in particular, the method relates to a method to form a semiconductor laser diode with a mesa structure buried with a semi-insulating semiconductor layer doped with iron (Fe).
2. Related Prior Art
One type of a semiconductor laser diode (hereafter denoted as LD) has been well known where a mesa structure including an active layer formed on an InP substrate is buried by a burying layer. A Japanese Patent Application published as JP-H06-085390A has disclosed an LD with such an arrangement where the LD includes the mesa structure containing an n-type lower cladding layer, an active layer, a p-type upper cladding layer and a p-type contact layer, each sequentially grown on the n-type InP substrate, and a semi-insulating burying layer made of InP doped with iron (Fe) formed so as to bury the mesa structure.
Because irons in the burying layer behaves as an electron trap to show the semi-insulating characteristic, when it is in contact with a p-type layer, electrons trapped by iron atoms in the burying layer may recombine with holes injected from the p-type contact layer, which causes a current leaking path from the contact layer to the burying layer; accordingly, the efficiency to inject carriers within the active layer is reduced.
One solution to reduce such a leak current has been proposed, where an additional current blocking layer made of n-type InP is formed on the semi-insulating burying layer to electrically isolate the p-type contact layer from the semi-insulating burying layer. However, the path from the p-type cladding layer to the semi-insulating burying layer still exists and the current injection efficiency has a scope to be further enhanced.
SUMMARY OF THE INVENTION
A semiconductor light-emitting device according to the present invention has a feature that provides a p-type InP substrate; a mesa structure including a p-type buffer layer, an active layer, and an n-type cladding layer; an n-type blocking layer; and a semi-insulating burying layer. The n-type blocking layer covers the p-type InP substrate and at least the p-type buffer layer within the mesa structure to isolate the semi-insulating burying layer from the substrate and the p-type buffer layer.
The invention further provides a feature in a method to form the semiconductor light-emitting device, comprising steps of: (a) growing semiconductor layers including the p-type buffer layer, the active layer and the n-type cladding layer on the p-type semiconductor substrate in this order; (b) forming the mesa structure; (c) growing the n-type blocking layer on the p-type substrate, this blocking layer including a plane portion deposited on the p-type substrate and a wall portion deposited on both side surfaces of the mesa structure; (d) selectively etching the wall portion of the n-type blocking layer; and (e) growing the semi-insulating burying layer doped with iron so as to bury the mesa structure.
The light-emitting device of the invention may further provide an un-doped layer between the active layer and the p-type buffer layer. This un-doped layer may relax the condition required in the n-type blocking layer, in particular, a thickness of the layer. The n-type blocking layer may cover at least a portion of the un-doped layer within the mesa structure to isolate the p-type buffer layer from the semi-insulating burying layer.
According to the method of the invention, the n-type blocking layer may isolate the burying layer from the p-type substrate so as to prevent the inter-diffusion of dopants in the p-type substrate and in the burying layer, which may reduce the leak current. Because the selective etching forms the n-type blocking layer, the dimensions of the n-type blocking layer becomes optional; accordingly, the n-type cladding layer in the mesa structure may be reliably isolated from the n-type blocking layer.
Moreover, the process may further include the etching of the p-type substrate after the formation of the mesa structure. This additional etching may expose the surface of the p-type substrate with the (111) and its equivalent orientations. Because of the crystallographic characteristic of the semiconductor material, the surface with the (100) or its equivalent orientations is hard to be etched compared to surfaces with the (011) or (111) and their equivalent orientations, which enhances the selectiveness of the etching of the n-type blocking layer.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A to 1C illustrate processes to grow semiconductor layers on the p-type semiconductor substrate and to form the mesa structure including grown layers;
FIG. 2A illustrates a process to etch the p-type substrate to appear the surface with the (111) orientation, and FIG. 2B illustrates a process to grow the n-type blocking layer on the p-type substrate and the side of the mesa structure;
FIG. 3A illustrates a process to etch the wall portion of the n-type blocking layer deposited on the side of the mesa structure, and FIG. 3B illustrates a process to bury the mesa structure by growing the burying layer;
FIG. 4A illustrates a process to remove the cap layer, and FIG. 4B illustrates a process to form the passivation layer on the mesa structure and on the burying layer;
FIG. 5A illustrates a process to form the opening in the passivation layer, and FIG. 5B illustrates a process to form the n-type electrode in the opening and the p-type electrode in the back surface of the p-type substrate; and
FIG. 6 illustrates a cross section of a modified light-emitting device that includes an un-doped layer between the p-type buffer layer and the active layer.
DESCRIPTION OF PREFERRED EMBODIMENTS
Next, preferred embodiments of the present invention will be described as referring to accompanying drawings.
FIGS. 1A to 1C show processes to form the mesa structure M. First, a series of semiconductor layers, 12 a , 14 a , 16 a and 18 a , is grown on the primary surface 10 with the (001) surface orientation of a p-type InP substrate 10 by the conventional Organo-Metallic Vapor Phase Epitaxy (OMVPE) method.
The substrate is a p-type InP doped with zinc (Zn) by a concentration of about 1×10 18 cm −3 and with a thickness of about 350 μm. The layer 12 a becomes the p-type buffer layer 12 , which is a p-type InP doped with Zn by a concentration of about 1×10 18 cm −3 and with a thickness of about 550 nm.
The layer 14 a becomes the active layer 14 . The layer 14 a may include a plurality of well layers and a plurality of barrier layers alternately stacked with each other, which constitutes the multiple quantum well (MQW) structure. The well layer may be InGaAsP with a band gap wavelength of 1.6 μm and a thickness of one layer of about 5 nm, while the barrier layer may be also InGaAsP but with a composition different from the well layer. The band gap wavelength of the barrier layer is about 1.25 μm and a thickness of one layer is about 10 nm, then a total thickness of the active layer becomes 224 nm. This active layer with the MQW structure may emit light with a wavelength of about 1.55 μm.
The layer 16 a becomes the n-type cladding layer 16 . The layer 16 a may be an n-type InP doped with silicon (Si) by a concentration of about 1×10 18 cm −3 and with a thickness of about 2000 nm. The layer 18 a becomes a cap layer 18 in the mesa structure M. The layer 18 a may be an n-type InGaAs doped with Si by a concentration of about 1×10 19 cm −3 and with a thickness of about 200 nm.
Next, as shown in FIG. 1B , the process forms a mask layer 20 with a striped pattern on the layer 18 a , a position of the mask layer 20 is aligned with the mesa structure M. The mask layer 20 may be made of silicon oxide (SiO 2 ) and with a thickness of about 2 μm. The striped pattern of this mask layer 20 may be formed by the ordinary photolithography with a subsequent etching process.
The process etches a portion of the semiconductor layers, 12 a to 18 a not covered by the mask layer 20 to form the mesa structure M. The conventional reactive ion etching (RIE) may carry out this etching process by a mixed reactive gas of methane (CH 4 ) and hydrogen (H 2 ). One exemplary composition of the reactive gas may be obtained by the flow rate of respective gasses of 25 sccm, which realizes an etching rate of about 1.8 μm an hour. However, the etching rate of the semiconductor layer strongly depends on various process conditions, such as the electrical power of the RF source, the pressure within the etching apparatus, and so on. The present rate described above enables the deep etching of about 3.6 to 3.7 μm to form, what is called as the high-mesa structure M shown in FIG. 1C .
After carrying out the dry etching using the RIE technique, the process etches a portion of the substrate 10 . Specifically, the process first removes the residual carbons accumulated around the mesa structure M due to methane (CH 4 ) in the etching gas by an etchant containing sulfuric acid for 2 minutes. Subsequently, the process etches a portion of the p-type InP substrate 10 with a mixed solution of hydrochloric acid (HCl) 150 cc, acetic acid (CH 3 COOH) 150 cc, hydrogen peroxide (H 2 O 2 ) 60 cc, and water 150 cc for 30 seconds to remove the surface layer damaged by the foregoing RIE process. This second wet-etching exposes the InP surface 10 b with the (111) orientation adjacent to the mesa structure M by removing the surface of the substrate 10 by about 100 nm as shown in FIG. 2A .
Next, the n-type blocking layer 26 is grown on the substrate 10 . FIG. 2B illustrates the process to grow the n-type blocking layer 26 on the surface 10 b of the substrate 10 and the side surfaces of the mesa structure M. This n-type blocking layer 26 is an n-type InP doped with silicon (Si) by a concentration of about 1×10 19 cm −3 and having a thickness of 1.2 to 1.3 μm grown by the OMVPE technique. Exemplary growth conditions are that a mixture of tri-methyle-indium (TMIn) and phosphine (PH 3 ) with mono-silane (SiH 4 ) for a dopant as the sources, a growth temperature of 620° C., and a reaction period of 35 to 40 minutes. The growth rate of about 2 μm an hour may be obtained under the conditions above.
The n-type blocking layer 26 includes a plane portion 26 a deposited on the surface 10 b of the substrate 10 and a wall portion 26 b deposited on the side surfaces of the mesa structure M. The plane portion 26 a may isolate the substrate 10 from the burying layer 32 and is preferable to have a thickness thereof smaller than a distance from the bottom 14 b of the active layer 14 to the top 10 b of the substrate 10 in the mesa structure, which is equivalent to a thickness of the p-type buffer layer 12 . Specifically, the thickness of the plane portion 26 a of the n-type blocking layer 26 is preferably 0.2 to 0.3 μm. This is due to the reason that the subsequent etching described below does not cause the current leaking path from the n-type cladding layer 16 to the n-type blocking layer 26 . When the n-type blocking layer 26 has such a thickness, the burying layer 32 , which has a semi-insulating characteristic primarily for electrons, may come in contact with the p-type buffer layer 12 . However, because of its high resistivity of the semi-insulating burying layer 32 , the contact between the p-type buffer layer 12 and the burying layer 32 is not significant.
More preferably, the thickness of the plane portion 26 a of the blocking layer 26 is substantially equal to a thickness of the p-type buffer layer 12 added with the depth of the substrate etched in the foregoing process to level the bottom 14 b of the active layer 14 with the top 26 c of the blocking layer 26 . The thickness of the blocking layer 26 may be adjustable by changing the growth time by the OMVPE technique.
Next, the process selectively etches the blocking layer 26 as shown in FIG. 3A . The wet-etching carried out in this step using a solution containing hydrochloric acid (HCl) 60 cc, acetic acid (CH 3 COOH) 300 cc and water 60 cc for 45 seconds selectively removes the wall portion 26 b of the blocking layer 26 . The etchant above mentioned selectively etches the surface of the n-type InP layer 26 with the (011) and (111) orientations but hardly etches the surface with the (100) and its equivalent orientations. Accordingly, this etchant may selectively remove the wall portion 26 b deposited on the side surfaces of the mesa structure M because the plane portion 26 a of the layer 26 reflects the (100) orientation of the substrate 10 , while, the wall portion 26 b shows the (011) and (111) surface orientations.
Next, the mesa structure M is buried with the semi-insulating burying layer 32 as illustrated in FIG. 3B . This burying layer 32 is an InP doped with iron (Fe) by a concentration of about 1.5×10 18 cm −3 with the OMVPE technique using tri-methyle-indium (TMIn) and phosphine (PH 3 ) as the source materials and ferocene (C 10 H 10 Fe) as the dopant material. Exemplary growth conditions are that the growth temperature of 620° C. and the growth rate of 2 μm an hour, where it is necessary to take one hour and fifteen to twenty minutes to obtain a thickness of 2.5 μm enough to bury the mesa structure M.
After the growth of the burying layer 32 , the mask 20 to form and to bury the mesa structure M is removed as shown in FIG. 4A . This mask 20 may be removed by, for instance, fluoric acid.
Next, the process forms the passivation layer 38 made of silicon oxide SiO 2 to cover the top of the mesa structure M and the burying layer 32 , as illustrated in FIG. 4B . Subsequently, this passivation layer 38 is processed so as to form an opening 38 a to expose a portion above the mesa structure M ( FIG. 5A ). The upper electrode 42 fills the opening 38 a of the passivation layer 38 and is put on the layer 38 . This upper electrode 42 corresponds to the n-type electrode made of AuGe eutectic metal. On the other hand, another electrode 44 is processed on the back surface of the substrate 10 ( FIG. 5B ). This electrode 44 corresponds to the p-type electrode and is made of AuZn eutectic metal. Thus, the light-emitting device of the present invention is completed.
According to the method of the present invention thus explained, the n-type blocking layer 26 may prevent the inter-diffusion between dopants in the p-type substrate 10 and those in the semi-insulating burying layer 32 . Moreover, because the n-type blocking layer 26 is formed by the OMVPE technique and the subsequent selective etching, the physical shape of the blocking layer 26 , especially the thickness of the plane portion 26 b may be optionally controlled and the blocking layer 26 may be escaped from being in contact with the n-type cladding layer 16 in the mesa structure M, which effectively prevents the current leaking path from causing.
The present invention has various modifications not restricted to those embodiments described above. It would be possible for an ordinal artisan in the fields to vary semiconductor materials of respective layers, their physical dimensions and conditions to process the semiconductor layers depending on requests.
For instance, it is possible to put separate confinement hetero-structure (SCH) layers between the MQW active layer 14 and the p-type buffer layer 12 and between the MQW active layer 14 and the n-type cladding layer 16 . These SCH layers may separately confine the carries within the MQW active layer 14 and the light within the MQW active layer 14 and these SCH layers. These SCH layers may have a thickness of about 50 nm and may be made of un-doped GaInAsP when the MQW active layer 14 is made of GaInAsP. These SCH layers, in particular, the layer between the MQW active layer 14 and the p-type buffer layer 12 may relax the condition of the thickness of the n-type blocking layer 26 , that is, the top level of the plane portion 26 b of the blocking layer 26 may be within the range of the thickness of this SCH layer.
Moreover, the mesa structure M may further include an un-doped semiconductor layer 50 between the lower SCH layer above mentioned and the p-type buffer layer 12 as illustrated in FIG. 6 . This additional layer 50 may be made of un-doped InP and have a thickness of about 100 nm, and may further relax the thickness condition of the n-type blocking layer 26 . The present invention, therefore, is limited only as claimed below and the equivalents thereof.
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A semiconductor light-emitting device with a new layer structure is disclosed, where the current leaking path is not caused to enhance the current injection efficiency within the active layer. The device provides a mesa structure containing active layer and a p-type lower cladding layer on a p-type substrate and a burying layer doped with iron (Fe) to bury the mesa structure, where the burying layer shows a semi-insulating characteristic. The device also provides an n-type blocking layer arranged so as to cover at least a portion of the p-type buffer lower within the mesa structure. The n-type blocking layer prevents the current leaking from the burying layer to the p-type buffer layer, and the semi-insulating burying layer that covers the rest portion of the mesa structure not covered by the n-type blocking layer prevents the current leaking from the n-type blocking layer to the n-type cladding layer within the mesa structure.
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[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/037,012, filed Mar. 17, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to compositions or combinations of compounds that mitigate coke formation in thermal cracking furnaces.
BACKGROUND OF THE INVENTION
[0003] In the production of olefins, ethylene in particular, a typical hydrocarbon stream like ethane, propane, butane, naphtha and gas oil, is pyrolyzed at high temperatures in a thermal furnace. The product is a mixture of olefins which are separated downstream. In the production of ethylene, typically water is co-injected with the hydrocarbon feed to act as a heat transfer medium and as a promoter of coke gasification. Typically, a minor but technologically important byproduct of hydrocarbon steam cracking is coke. Steam from the water co-injected reacts with the coke to convert it partially to carbon monoxide and hydrogen. Because of the accumulative nature, coke deposits build up on the reactor walls thus increasing both the tube temperatures and the pressure drop across the tube. This requires shutting down the process for decoking. This periodic shutdown results in an estimated $2 billion in lost ethylene production per year. In addition there is a direct relationship between the amount of coking and the yield of the olefin, indicating that the coke is formed at the expense of product olefin.
[0004] It is common practice in commercial ethylene production to co-inject along with the hydrocarbons, small amounts of sulfur containing compounds such as hydrogen sulfide (H 2 S), dimethyl sulfide (DMS) or dimethyl disulfide (DMDS) to minimize coke formation. It has been proposed that the sulfur passivates the active metal surface known to be a catalyst for coke formation. In addition, the sulfur compounds are known to reduce the formation of carbon monoxide (CO), formed by the reaction of hydrocarbons or coke with steam, again by passivating the catalytic action of the metal surface and by catalyzing the water gas shift reaction which converts the CO to carbon dioxide (CO 2 ). Minimizing the amount of CO formed is essential for the proper functioning of downstream reduction operations.
[0005] U.S. Pat. No. 4,404,087 discloses that pretreating cracking tubes with compositions containing tin (Sn) compounds, antimony (Sb) and germanium (Ge) reduces the rate of coke formation, during the thermal cracking of hydrocarbons.
[0006] Combinations of Sn, Sb and Si are disclosed to do the same in U.S. Pat. No. 4,692,234.
[0007] Mixtures of chromium and antimony compounds, chromium and tin compositions, and antimony and chromium compositions have also been claimed to reduce coke formation, as measured by a time weighted CO selectivity index (U.S. Pat. No. 4,507,196).
[0008] Several phosphorous and sulfur compound combinations are disclosed (U.S. Pat. No. 5,954,943) with Sn and Sb compounds (U.S. Pats. Nos. 4,551,227; 5,565,087 and 5,616,236), for decreasing the coke formed in hydrocarbon pyrolysis furnaces.
[0009] In general, U.S. Pats. Nos. 4,507,196; 4,511,405; 4,552,643; 4,613,372; 4,666,583; 4,686,201; 4,687,567; 4,804,487; and 5,015,358, teach that the metals Sn, Ti, Sb, Ga, Ge, Si, In, Al, Cu, P, and Cr, their inorganic and organic derivatives, individually or as mixtures will function as antifoulants for the reduction of coke during hydrocarbon pyrolysis.
[0010] Phosphoric acid and phosphorous acid mono and di-esters or their amine salts, when mixed with the feed to be cracked, for example, ethane, showed a significant increase in run lengths compared to an operation performed without the additives (U.S. Pat. No. 4,105,540).
[0011] Pretreating furnace tubes at high temperature with aromatic compounds such as substituted benzenes, naphthalenes and phenanthrenes, prior to introduction of the cracking feed has been shown to reduce catalytic coke formation (U.S. Pat. No. 5,733,438). Cracking a heavy hydrocarbon, preferably a higher olefin stream prior to bringing on the lower hydrocarbons, has been shown to reduce coking (U.S. Pat. No. 4,599,480). In both cases, a thin layer of catalytically inactive coke formed on the tube surface is claimed to inhibit the propagation of coke formation.
[0012] Several patents disclose the use of various Si compounds to lay down a ceramic layer on metal tubes and thus reduce the coke formed in pyrolysis. Compounds such as siloxanes, silanes and silazanes have been used to deposit a silica layer on the metal alloy tubes (U.S. Pats. Nos. 5,424,095; 5,413,813; and 5,208,069). Silicates have been independently claimed to do the same in patent GB 1552284. In almost all of the examples the coke minimization is of catalytic coke, formed mainly during the early stages of pyrolysis. A patent (U.S. Pat. No. 5,922,192), teaches the use of a silicon compound and a sulfur compound as a mixture that contains Si/S ratio of 1/1 to 5/1 to mitigate coke formation.
[0013] Another approach to reduce coking is to passivate the active metal surface of pyrolysis tubes by forming a surface alloy, comprising metals/oxides of metals that are known to not catalyze coke formation. High Temperature Alloys (HTA) are a group of austenitic stainless steels used in industrial processes operating at elevated temperatures above 650° C. These typically contain 118-38% Cr, 18-48% Ni, with the balance being Fe and alloying additives. Iron and nickel are known catalysts for the formation of filamentous carbon during ethylene production and hydrocarbon pyrolysis in general. An oxide layer of chromium or aluminum on the other hand are known to be inhibitors of catalytic coke formation and thus are used to protect these alloys. Protection using these oxides have to be carefully engineered so that physical characteristics and properties of the HTA, such as creep resistance, are not compromised and the oxide layer is stable to harsh conditions typically encountered in hydrocarbon pyrolysis. CoatAlloy™ is a surface coating technology for the inside of HTA tubes for use in an ethylene furnace. Cr—Ti—Si and Al—Ti—Si formulated products are coated on a base alloy surface and heat treated to form either a diffusion protective layer only or a diffusion layer and a enrichment pool layer next to it. In both cases, oxidizing gases are passed to activate the layers by formation of alumina and/or chromia along with titania and silica. The treated tubes have been claimed to significantly reduce catalytic coke formation, minimize carburization of the base alloy tubes, exhibit improved erosion resistance and thermal shock resistance (U.S. Pat. No. 6,093,260). The ethane gas stream used to test the effectiveness of the coating contained 25-30 PPM of sulfur. A combination of sulfur containing compounds such as an alkyl mercaptan- or alkyl disulfide and a nitrogen containing compound such as hydroxylamine, hydrazine or amine oxide are disclosed as useful in pretreating or minimizing coke formation in thermal furnaces (U.S. Pat. No. 6,673,232).
[0014] Reduction of coking rates on both quartz and Incoloy surfaces by the use of low concentrations of hexachloroplatinic acid (H 2 PtCl 6 ) in the steam used for ethane cracking, have been reported (Industrial & Engineering Chemistry Research, Vol: 37, 3, 901, 1998). Coke formation rates were reduced although the apparent activation energies increased. The reduced effectiveness of the additive at higher temperatures suggests that the primary impact of the additive was on the surface coke formation process.
[0015] The typical previous approaches have involved either metal passivation techniques with various additives like sulfur, silicon, phosphorous, etc., or the use of special alloys which reduce coking. These are surface treatments. The use of phosphorus containing compounds has become problematic due to adverse affects on downstream operations. Similarly, the use of amines and derivatives thereof has become problematic due to the formation of NOx and its impact on downstream operations.
[0016] The objective of the present invention was to develop improved technology for reducing the formation of coke in commercial thermal cracking furnaces. Reduced coke levels will translate into higher ethylene yields, longer radiant furnace tube life and reduced downtime for decoking of the unit which allows increased total production.
SUMMARY OF THE INVENTION
[0017] The invention is a combination useful for reducing or preventing coke formation in thermal cracking furnaces such as ethylene steam crackers. The compounds in the combination of the present invention decompose into compounds such as H 2 S which are easily removed in downstream operations. The present invention is directed to a combination including hydrocarbons containing no heteroatoms and hydrocarbons containing sulfur as a heteroatom. The combinations of the present invention comprise
[0000] (A) one Or more compounds of the formula:
[0000] R—S x —R′
[0018] wherein R and R′ are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl and x=1 to 5; and
[0000] (B) one or more compounds selected from the following group:
[0000] R 1 R 2 CS 3
[0000] wherein R 1 and R 2 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl (e.g., alkylaryl trithiocarbonates);
[0000] R 1 R 2 C═CR 3 R 4
[0000] wherein R 1 , R 2 , R 3 and R 4 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl (e.g., alkyl/aryl ethylenes);
[0000] RSH
[0000] wherein R is alkyl of 1 to 24 carbons straight chain or branched (e.g. alkyl/aryl mercaptans);
[0000] R 1 S x R 2
[0000] wherein R 1 and R 2 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl and x=2 to 5 (e.g. alkyl/aryl polysulfides);
[0000] R 1 R 2 CH 2
[0000] wherein R 1 and R 2 are independently aryl or alkyl substituted aryl with the alkyl group being h or alkyl with 1 to 24 carbons (e.g. diphenylmethane);
[0000] R 1 R 2 R 3 CH 2
[0000] wherein R 1 , R 2 , R 3 and R 4 are independently h, alkyl with 1 to 24 carbons straight or branched, aryl (e.g. thiophene or substituted thiopenes); and
[0000] R 1 R 2 R 3 R 4 R 5 R 6 Si 2 O
[0000] Wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently h, alkyl with 1 to 24 carbons straight or branched, aryl (e.g. substituted disiloxanes).
[0019] The invention is also directed towards an improved process for producing olefinic materials like ethylene or propylene by the introduction of the above mixture to the hydrocarbon feed stream to be cracked or to another feed stream such as water/steam prior to either of the streams entering the thermal cracking furnace.
DETAILED DESCRIPTION OF THE INVENTION
[0020] There are two basic mechanisms for the formation of coke in ethylene furnaces, catalytic, and non-catalytic. In catalytic coke formation, hydrocarbon is adsorbed on a metal site. As the metal catalyzes the decomposition of the hydrocarbon to elemental carbon, the carbon diffuses through the metal particle. Precipitation of the carbon vapor occurs beneath the surface and the metal particle is actually lifted off from the surface. This process of carbon diffusion and precipitation occurs over and over with the result that filaments (each tipped with a metal particle) of carbon are formed on the inside surface of the cracking tubes. Sulfur and phosphorous derivatives have been used to reduce the amount of catalytic coke formation presumably by passivating the metal surface to reduce or eliminate the phenomena that results in the formation of the carbon filaments.
[0021] In non-catalytic coke formation, hydrocarbons decompose in the gas phase thermally via free-radical reactions. Many of these reactions result in the formation of useful compounds like ethylene, propylene, etc. However, various recombination reactions can result in the formation of longer-chain species that can be trapped in the surface carbon filaments. As time goes on, these coke precursors grow and become full-fledged coke. Other long-chain species can exit the reactor and condense in the cooling section. The end result of these non-catalytic reactions is the formation of additional coke and/or heavy condensates, both of which act to reduce ethylene formation.
[0022] The majority of the prior art has only addressed preventing the formation of catalytic coke by passivation of the metal surface. The present invention addresses both the formation of catalytic and non-catalytic coke. This approach will lead to lower levels of total coke formation than those previously described and will result in decreased downtime for the commercial units.
[0023] In the broadest sense, the present invention combines surface treatment to passivate the metal to reduce catalytic coke formation with the reduction of gas-phase coke formation. Thus, any compound known to passivate metal surfaces in conjunction with compounds known to scavenge free radicals like phenol derivatives, mercaptans, hydrazines, phosphines, etc., are within the scope of the present invention.
[0024] The present invention is also an improved process for producing olefinic materials like ethylene or propylene by the introduction of the above components to the hydrocarbon feed stream to be cracked or to another feed stream such as water/steam prior to either of the streams entering the thermal cracking furnace.
[0025] The sulfur-containing compounds useful in the present invention have the formula
[0000] R—S x —R′
[0000] wherein R and R′ are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl and x=1 to 5
[0026] Examples of such compounds include H 2 S, methyl-, ethyl-, propyl-, butyl- and higher mercaptans, aryl mercaptans, dimethyl sulfide, diethyl sulfide, unsymmetrical sulfides such as methylethyl sulfide, dimethyl disulfide, diethyl disulfide, methylethyl disulfide, higher disulfides, mixtures of disulfides like merox, sulfur compounds naturally occurring in hydrocarbon streams such as thiophene, alkylthiophenes, benzothiophene, dibenzothiophene, polysulfides such as t-nonyl polysulfide, t-butyl polysulfide, phenols and phosphines. Preferred are alkyl disulfides such as dimethyldisulfide and most preferred is dimethyl sulfide. Preferred treatment ranges of material are from 10 ppm to 1000 ppm relative to the hydrocarbon feed stream. More preferred is 50 to 500 ppm, and most preferred is 100 to 400 ppm. Ratios of the sulfur-containing material to the tree-radical-scavenging component range from 1-0.1 to 1-100 (weight-to-weight).
[0027] Component B compounds are selected from the group having the following formulas:
[0000] R 1 R 2 CS 3
[0000] wherein R 1 and R 2 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl (e.g., alkyl/aryl trithiocarbonates);
[0000] R 1 R 2 C═CR 3 R 4
[0000] wherein R 1 , R 2 , R 3 and R 4 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl (e.g., alkyl/ethylenes);
[0000] RSH
[0000] wherein R is alkyl of 1 to 24 carbons straight chain or branched (e.g. alkyl/aryl mercaptans);
[0000] R 1 S x R 2
[0000] wherein R 1 and R 2 are independently H, alkyl with 1 to 24 carbons straight chain or branched, aryl and x=2 to 5 (e.g. alkyl/aryl polysulfide);
[0000] R 1 R 2 CH 2
[0000] wherein R 1 and R 2 are independently aryl or alkyl substituted aryl with the alkyl group being h or alkyl with 1 to 24 carbons (e.g. diphenylmethane);
[0000] R 1 R 2 R 3 R 4 (C 4 S)
[0000] wherein R 1 , R 2 , R 3 and R 4 are independently h, alkyl with 1 to 24 carbons straight or branched, aryl (e.g. thiophene or substituted thiopenes; and
[0000] R 1 R 2 R 3 R 4 R 5 R 6 Si 2 O Wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently h, alkyl with 1 to 24 carbons straight or branched, aryl (e.g. substituted disiloxanes).
[0029] Examples of such compounds include 2,4-diphenyl-4-methyl-1-pentene (an alpha-methyl-styrene dimer), triphenylmethane, terpilolenie, decalin and thiophene. Preferred ranges of material are from 10 ppm to 1000 ppm relative to the hydrocarbon feed stream. More preferred is 50 to 500 ppm, and most preferred is 100 to 400 ppm. Ratios of the material to the sulfur-containing component range from 1-0.1 to 1-100 (weight-to-weight).
[0030] This combination is useful for reducing or preventing coke formation in thermal cracking furnaces such as ethylene steam crackers.
[0031] Also, the use of the combinations described above with various surface treatments, pretreatments, special alloys, and special tube coatings described in the prior art is within the scope of this invention.
[0032] The present invention discloses a synergy between sulfur chemicals like DMS or DMDS (which passivate the metal surface) and free-radical scavengers, such as an alpha-methyl-styrene dimmer and terpinolene or thiophene which inhibit coke formation in the gas phase by scavenging newly forming coke precursors. Independent of the mechanism, the synergy exhibited between the abovementioned compounds which results in lower levels of total coke formation than either of the components used alone is surprising and unexpected.
[0033] A preferred method to practice this invention is to co-inject either separately or together a mixture of DMS or DMDS, and a free-radical scavenger, such as an alpha-methyl-styrene dimmer and terpinolene or thiophene into the hydrocarbon feed stream just prior to its introduction to the furnace. Optimal treatment levels will depend on the operational variables of individual commercial furnaces, but levels between 10 ppm and 1000 ppm of each component should cover the majority of commercial situations.
[0034] An advantage of the present invention is that the treatment levels of each component can be tailored and optimized for each commercial unit depending on its operational variables.
[0035] In theory, it is desirable that minimal decomposition of the disclosed materials occurs prior to its introduction to the cracking tubes of the furnace. Thus, the method of injection into the furnace is likely to have a major impact oil this. Systems which allow rapid injection with little preheating should give better results.
[0036] This invention could also have utility in conjunction with the development of new alloys or tube coatings being developed to reduce or eliminate the formation of catalytic coke.
[0037] Many hydrocarbon feed streams contain naturally occurring sulfur compounds like thiophenes, benzothiophenes, dibenzothiophenes, sulfides, and disulfides. The use of the naturally occurring sulfur compounds with the abovementioned free-radical scavengers is within the scope of this invention.
[0038] The following Example is offered to illustrate this invention and the modes of carrying out this invention.
EXAMPLES
Example 1
[0039] A coupon of HP-40 was made via wire erosion and cleaned with acetone in an ultrasonic bath. The cleaned coupon was hung in a thermo balance and exposed, at 800° C., to the cracking products of the pyrolysis of the feedstock (n-heptane) with and without additives being tested for one hour. The coupon was initially prepared by repeated cycles of coking/decoking. The coupons were pretreated with DMDS, argon, nitrogen and water for 30 minutes to one hour to pre-sulfide the coupon surface. Thereafter, the liquid feedstocks were dosed into the apparatus by means of a micro pump. The feedstock stream was vaporized prior to entering the apparatus. The dilution gases, argon and nitrogen, were introduced as was air during decoking cycles. The cracked products formed during the reaction were cooled to room temperature. Thereafter, a cracked gas sample was analyzed via gas chromatograph and the n-heptane conversion, composition of the cracked products and the cracking severity were determined. Hydrogen and carbon monoxide content in the product gas stream were determine in a second gas chromatograph. The amount of coke formed and the rate of formation were measured and plotted verses time. The coupon was decoked between each experiment. The test conditions are summarized in Table 1 and the results are summarized in Table 2.
[0000]
TABLE 1
Feedstock
n-heptane
Furnace Temp. (° C.)
800
Run Tim (min)
60
Feedstock (g/hr)
55
Diluent water (ml/h)
13
Diluent argon (1/hr)
7
Dilution Ration (g/)
0.45
DMDS (ppmw)
200
Additives (ppmw)
200
Cracking severity
21.-2.2
(m C 2 H 4 /m C 3 H 6 )
Residence time t (sec)
About 0.6
[0000]
TABLE 2
Additive
Coke (mg)
%
Coke Rate
%
N-heptane +200 ppm DMDS
36.30
407
N-heptane +200 ppm DMDS +
44.72
87
544
85
200 ppm additive
N-heptane +200 ppm DMDS
66.50
869
N-heptane +200 ppm DMDS +
61.75
84
811
87
200 ppm additive
N-heptane +200 ppm DMDS
80.52
994
N-heptane +200 ppm DMDS
58.75
624
N-heptane +200 ppm DMDS +
70.03
79
714
82
300 ppm additive
N-heptane +200 ppm DMDS
117.62
1124
N-heptane +200 ppm DMDS +
99.83
80
999
82
300 ppm additive
N-heptane +200 ppm DMDS
131.35
1293
[0040] The data in Table 2 shows that the use of the additives at a level of 200 ppm resulted in approximately a 15% reduction in coke formation and when the additives treatment levels were increased to 300 ppm, the coke formation levels decreased by about 20%.
[0041] While the present invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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The invention relates to a combination of compounds and a process using such combination useful for reducing or preventing coke formation in thermal cracking furnaces such as ethylene steam crackers. The combination is comprised of one or more compound of the formula R—S x —R′ and one or more compound selected from the following group: R 1 R 2 CS 3 ; R 1 R 2 C═CR 3 R 4 ; RSH; R 1 S x R 2 ; R 1 R 2 CH 2 ; R 1 R 2 R 3 R 4 (C 4 S); and R 1 R 2 R 3 R 4 R 5 R 6 Si 2 O.
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RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. 119 (e) of U.S. Provisional Patent Application Ser. No. 61/102,830, filed on Oct. 4, 2008, which is incorporated herein by reference in it entirety.
BACKGROUND
[0002] Using a charge transfer capacitive measurement approach, such as that described in U.S. Pat. No. 6,452,514, it is possible to create touch sensing regions that can detect human touch through several millimeters of a plastic or glass front panel. In prior devices, the electrodes are formed on a separate substrate that is glued or held in contact with the front panel, and this panel is then electrically interconnected to a main printed circuit board (PCB) using wires in the form of a connector, or wiring loom. The interconnect can also be somewhat problematic because it can move, causing changes in capacitance and it also introduces some fixed amount of stray capacitance that acts to desensitize the touch control.
[0003] In the above charge transfer capacitive measurement approach, a transmit-receive process is used to induce charge across the gap between an emitting electrode and a collecting electrode (the transmitter and the receiver respectively, also referred to as X and Y). As a finger touch interacts with the resulting electric field between the transmitter and receiver electrodes, the amount of charge coupled from transmitter to receiver is changed. A particular feature of the above approach is that most of the electric charge tends to concentrate near sharp corners and edges (a well known effect in electrostatics). The fringing fields between transmitter and receiver electrodes dominate the charge coupling. Compatible electrode design therefore tends to focus on the edges and the gaps between neighboring transmitter and receiver electrodes in order to maximize coupling and also to maximize the ability of a touch to interrupt the electric field between the two, hence giving the biggest relative change in measured charge. Large changes are desirable as they equate to higher resolution and equally to better signal to noise ratio.
[0004] A specially designed control chip can detect these changes in charge. It is convenient to think of these changes in charge as changes in measured coupling capacitance between transmitter and receiver electrodes (charge is rather harder to visualize). The chip processes the relative amounts of capacitive change from various places around the sensor and uses this to detect the presence of a touch on a touch button. Commonly, these electrodes are required to be transparent so that light can pass through the touch sensor to provide aesthetic and/or functional illumination effects.
[0005] An advantage of the charge transfer capacitive measurement approach is that many touch sensors can be formed at a lower “cost per sensor” than other techniques. This is because the intersection between every X and Y electrode can form a touch sensor. For example, a system that has 10 X electrodes and 8 Y electrodes can be used to form 80 touch sensors. This requires only 18 pins on a control chip, whereas an equivalent open-circuit sensing scheme would need 80.
[0006] The charge transfer capacitive measurement approach is a transmit-receive architecture that uses a two-part electrode design. A typical prior-art electrode design is show in FIG. 1 . Here a transmit 100 and receive 101 element are shown that serve to couple an electric field 102 between the two.
[0007] In FIG. 2 , the prior art electrode design is shown in cross section with the transmit 200 and receive 201 elements bonded or pushed against an insulating front panel 202 . The electric field 203 coupled between the two elements can be disrupted 204 by the presence of a finger or other touching object 205 . This serves to decrease the mutual capacitance from transmit to receive element, this change being sensed by a control circuit 206 to register an output 207 to indicate the presence (or not) of the touch 205 .
SUMMARY
[0008] A touch sensitive device includes transmit and receive electrodes separating a substrate and a touch panel. Selected electrodes may be formed of conductive compressible material compressed between the substrate and the touch panel. Some electrodes are supported by the substrate and are arranged to form an electrical field coupling with the conductive compressible electrodes. The electrical field coupling is configured to change in response to a touch event of the touch panel near a conductive compressible electrode. In some embodiments, electrodes may be transparent to allow illumination through the electrode. In some embodiments, electrodes may include holes to allow illumination through the touch panel from light sources supported by the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a top view of a prior art layout of electrodes for a capacitive based touch sensor.
[0010] FIG. 2 is cross section of the prior art layout of FIG. 1 .
[0011] FIG. 3 is a cross section of an electrode configuration using springs between the electrodes and a front panel according to an example embodiment.
[0012] FIG. 4 is a cross section of an example electrode configuration using springs between the electrodes and a front panel according to an example embodiment.
[0013] FIG. 5A is a cross section of an electrode configuration using springs between electrodes and a front panel according to an example embodiment.
[0014] FIG. 5B is a cross section of an electrode pair with a spring showing a touch according to an example embodiment.
[0015] FIG. 6A is cross section of a further electrode configuration using springs between electrodes and a front panel according to an example embodiment.
[0016] FIG. 6B is a perspective representation of a spring with electrodes according to an example embodiment.
[0017] FIG. 7A is a cross section of an electrode configuration using springs between electrodes and a front panel according to an example embodiment.
[0018] FIG. 7B is a cross section of an electrode pair with a spring showing a touch and electric field fringe lines according to an example embodiment.
[0019] FIG. 8 is a cross section of an electrode configuration having a hole and spring according to an example embodiment.
[0020] FIG. 9 is a cross section of an electrode configuration having electroluminescent light generation and a spring according to an example embodiment.
[0021] FIG. 10 is a perspective representation of an electrode configuration having a light diffuser and a spring according to an example embodiment.
[0022] FIG. 11 is a cross section representation of an electrode configuration with a light emitting diode and spring according to an example embodiment.
DETAILED DESCRIPTION
[0023] A structure for a touch control uses a compressible conductive material to form a touch sensitive region at some distance from a control circuit. Using traditional capacitive sensing methods that rely on an open-circuit electrode arrangement, it is easy to use a conductive spring or other compressible material to transfer the touch sensitive region from a substrate, such as a control printed circuit board (PCB) up to a front panel. In some embodiments, no special interconnection is required at the front panel; the “spring” simply pushes up against the front panel and has sufficient surface area when compressed to form a touch control. As a result, significant cost savings can be realized during assembly because the whole sensor PCB becomes self contained with the “springs” installed onto conductive traces on the PCB. The PCB itself is then fixed in place relative to the front panel with the “springs” held in compression to ensure a mechanically stable system (import for capacitive touch controls as any movement can cause fluctuations in the signals measured from the sensor).
[0024] A charge transfer capacitive measurement approach, such as described in U.S. Pat. No. 6,452,514, (or other transmit receive method) may be used with a touch sensitive device having a mechanical “spring” arrangement between a control printed circuit board (PCB) and a front panel. It should be understood that any compressible conductive material could be used to form this “spring”. So long as the electrical resistivity of the spring is moderately low, such as for example, below 100K ohms in one embodiment, then any compressible conductive material, such as metal or plastic springs, open or closed cell foam or further such materials may be used. In some embodiments, the resistivity may be 10K ohms, or 1K ohms or less.
[0025] It should be noted that the examples cited place the transmit and receive elements on the same plane and hence require only one layer to implement on a substrate. It is equally possible to form a charge transfer capacitive measurement touch sensor across two layers i.e. with X below Y.
[0026] One way to use springs to transfer the “intersection” of X and Y up to a front panel includes the use of two concentric or side-by-side springs on a substrate such as the control board, or any other type of substrate, such as a piece of plastic sheet such as PET or polycarbonate, a glass layer, or other material suitable for supporting electrodes. The substrate may provide a mechanical support with electrical connections to the electrodes by use of discrete wiring. This example embodiment is shown in FIG. 3 . Here a first X spring 300 and a first Y spring 301 are placed next to each other and pressed in contact with a front panel 302 . A second X/Y pair is shown alongside the arrangement, using the same X line interconnected by a wire or track 303 connected to a second X spring 304 and a second Y spring 305 . In this embodiment, the electric field 306 coupling from the first X spring 300 to the first Y spring 301 also tends to couple 307 to the second Y spring 305 . This may result in touch sensitivity of the second spring pair when touching over the first spring pair. This embodiment uses two springs per touch key.
[0027] In a further embodiment as shown in FIG. 4 , a common Y spring 400 is shared by two X springs 401 and 402 . Two touch keys are placed physically next to each other for this to function. The use of more than one Y line may result in some lack of key discrimination.
[0028] A further embodiment is shown in FIG. 5A . A substrate such as control PCB 500 is used to form all the X and Y electrode wiring 501 . A control chip 502 may or may not be present on this control board, but is used to measure capacitive changes in the touch keys. The Y electrodes shown, Y 1 503 and Y 2 504 are connected to a set of Y electrode springs 505 , 506 , 507 , and 508 , and 509 , 510 , 511 , and 512 , the first group being electrically connected to Y 1 and the second group to Y 2 , using traces on the PCB 500 to affect this interconnection. On the PCB 500 are formed a series of emitter X electrodes called X 1 to X 4 513 , 514 , 515 , 516 , 517 , 518 , 519 and 520 . These electrodes are formed purely as conductive shapes on the surface of the PCB 500 . In one embodiment, the X electrodes may be designed to substantially or completely surround the base of the Y springs 505 , 506 , 507 , 508 , 509 , 510 , 511 , and 512 . As can be seen, eight logical touch keys are so formed 532 , 533 , 534 , 355 , 536 , 537 , 528 and 539 ; X 1 Y 1 , X 2 Y 1 , X 3 Y 1 , X 4 Y 1 and X 1 Y 2 , X 2 Y 2 , X 3 Y 2 , X 4 Y 2 . Hence a total of eight springs are used ( 505 , 506 , 507 , 508 , 509 , 510 , 511 and 512 . The X electrodes, in one embodiment, have sufficient proximity to their neighboring Y spring to keep the electric fields well coupled locally. In FIG. 5B , a touching object 528 onto the front panel 529 now influences the coupled local X to Y field for predominantly the touch-adjacent touch key. Hence the key discrimination is good. The electric field for a single touch key is shown as 530 and its interaction with the touching object 528 is also shown at 531 .
[0029] An alternative scheme is shown in FIG. 6A where the springs 601 , 602 , 603 , 604 , 605 , 606 , 607 , and 608 are now connected to X 1 to X 4 emitters and the PCB 600 electrodes 609 , 610 , 611 , 612 , 613 , 614 , 615 and 616 are connected to Y. FIG. 6B illustrates a perspective view of spring 601 coupled to an X emitter electrode 621 . This alternate scheme may have an advantage in some applications where an improvement in key discrimination can be affected by virtue of the fact that the Y lines are rather more shielded by the X springs. Another potential advantage is that the Y electrode area can be reduced and hence help minimize noise injected into the Y line during touch. Attaining maximal signal to noise ratio in capacitive sensing systems helps to ensure reliable operation under electrically noisy conditions.
[0030] In some embodiments shown, the springs compress in such a way that the top of the spring forms a flat “spiral” disc. This lends itself well to coupling with the touching object and allowing an interaction with the electric field below the spiral.
[0031] In FIG. 6B , the X and Y electrodes 621 and 609 are shown as a disk 621 and concentric ring 609 physically separated from each other. Many other configurations of electrodes may be used in further embodiments. Further embodiments may feature increased shared electrode edges where field lines concentrate.
[0032] An alternative arrangement uses a substantially coaxial arrangement, where the springs are connected to X and surround simple Y receiver electrodes on the PCB. This is shown in FIGS. 7A and 7B for a pair of touch keys. The PCB 700 uses conductive electrodes for the two Y 1 receivers 701 and 702 . The X 1 emitter is formed from two springs 703 and 704 . The front panel 705 and touching object 706 are shown together with an approximate field distribution 707 and touch interaction 708 . As can be seen, the field is displaced away from the Y receiver in favor of the touching object 706 . This causes a drop in capacitance between X and Y as with the other embodiments. This method has a distinct advantage that the springs can be very simple in design, with no special flat-top arrangement. The touching object 706 effectively touches “inside” the coils of the spring influencing the field 707 and 708 . The spring can be driven from the PCB connection 700 using a contact formed by any conductive means e.g. solder, mechanical clip, glue or simple restraint against a conductive opposing pad on the PCB. Other methods will be obvious to those of normal skill in the art. This embodiment shares the advantage of FIGS. 6A and 6B in that the X spring acts to partly shield the Y receiver and the area of the Y receiver can be made relatively small to aid noise immunity.
[0033] Not shown is another embodiment, similar to FIGS. 7A and 7B where the springs are connected to Y and the PCB electrodes to X. In a similar way as described in the previous examples, this is equally valid but may show degraded key discrimination and noise immunity in some applications.
[0034] In FIGS. 7A and 7B it should be understood that the Y electrode shape can take various forms. Importantly, as shown in FIG. 8 , this can include a hole 801 in the electrode 802 formed on the PCB 800 . This is very useful to facilitate the placement of a light emitting device, shown in two alternative positions 803 and 804 . There are many configurations of electrode and hole that can be devised. It is also possible to form the PCB electrode from a conductive material that is substantially transparent to allow light to shine through from below. It is also possible to combine the electrode with some form electroluminescent light generation local to the centre of each spring. This is shown in FIG. 9 . The PCB 900 and spring 901 are shown, and in the middle of the spring 901 is shown an electrode structure where a transparent Y electrode 902 is formed on top of a phosphor 903 layer and a second electrode 904 that may be either grounded or actively driven. A control chip 905 time multiplexes capacitive measurements with electroluminescent high voltage drive 906 periods. This arrangement permits the light emitting layer to be created directly beneath the touch key active area with a very low profile and uniform illumination.
[0035] A similar light emission method can also be conceived where rather than an electroluminescent layer being used, instead a light diffuser sheet is placed below the PCB electrodes (again, being of substantially transparent material to allow the light to pass upwards towards the panel). The light diffuser sheet is well known in the art and typically is illuminated from the edges, uses total-internal-reflection (TIR) to guide the light to chosen areas where is then allowed to escape using a variety of techniques to disrupt the TIR process (mechanical stress, small ridges on the surfaces, refractive index mismatches etc).
[0036] Another illumination method is shown in FIG. 11 . Here, a coaxially mounted light emitting device 1100 in the centre of the spring 1101 , uses a reflective sleeve 1102 running up the inside of the spring 1101 and stopping just before the inner surface 1103 of the front panel 1104 . The sleeve may be made of any reflective material.
[0037] The spring used in FIG. 7 can also utilize an inward compressible spiral that flattens on compression. This is shown in FIG. 10 . An advantage of this method is that it helps to even more completely shield the electrode below 1001 . This may provide noise suppression advantages. The coil of the spring that spirals inwards 1005 may have a moderately open structure to allow the touching object 1002 to interact with the electric field 1003 formed between the spring 1004 and the electrode 1001 on the PCB 1000 .
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A device includes a substrate, a top touch panel, and an electrode supported by the substrate including a conductive compressible material extending from the substrate to the top touch panel. Another electrode is supported by the substrate and arranged to form an electric field coupling with the electrode including the compressible material. A touch sensitive region is transferred from the substrate to the top touch panel by the compressible material.
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This Nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 2003-346023 filed in Japan on Oct. 3, 2003, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheath flow forming device and sample analyzer provided with same.
2. Background
A particle analyzer (refer to Japanese Laid-Open Patent Publication No. 9-288053) is a known prior art related to the present invention and includes a container for accumulating a sample liquid containing particles to be analyzed and having a nozzle extending downward from the bottom part, a flow cell into which the tip of the nozzle is inserted, a first pump for injecting into the flow cell a first flow quantity Q1 of a sheath fluid which encapsulates a sample fluid flow injected from the nozzle, and an imaging means for imaging particles in the sample fluid encapsulated in the sheath fluid flowing through a transparent container formed on the downstream side of the flow cell, wherein the top part of the sample fluid container is open to the air, and a second pump is provided for suctioning fluid in the flow cell downstream from the transparent tube path of the flow cell, such that the sample fluid flow quantity Qs is determined by (Q2−Q1) when the injection quantity of the first pump is designated Q1 and the suction quantity of the second pump is designated Q2.
In this conventional device, the sample fluid flow quantity Qs is determined by the difference in the flow quantities of the pumps (Q2−Q1). When one flow quantity changes due to a change in the drive sources of the first and second pumps, the flow quantity Qs fluctuates greatly since the flow quantity Qs is quite small (for example, 1/100) compared to the flow quantities Q1 and Q2. Accordingly, problems arise when this occurs inasmuch as the particle flow in the sample fluid becomes unstable, the measurement accuracy is reduced, and at times measurement becomes impossible.
SUMMARY OF THE INVENTION
In view of these problems, the present invention provides a sheath flow forming device and sample analyzer provided with same, which are capable of normally maintaining a constant flow quantity Qs even when the flow quantities Q1 and Q2 change due to the influence of the drive source of the pumps.
The sheath flow forming device embodying features of the present invention includes: (a) a container for storing sample fluid and having a supply port for supplying the sample fluid; (b) a second container for storing sheath fluid and having a supply port for supplying the sheath fluid; (c) a flow cell having a sample fluid inlet for receiving sample fluid supplied from the supply port of the first container, a sheath fluid inlet for receiving the sheath fluid from the supply port of the second container, and an outlet for discharging the mixture of the sheath fluid and the sample fluid; (d) a first pump for supplying a sheath fluid to the sheath fluid inlet; (e) a second pump for suctioning fluid within the flow cell through the outlet of the flow cell; and (f) a first drive source for driving the first pump and second pump.
The sample analyzer embodying features of the present invention includes: (a) a first container for storing sample fluid and having a supply port for supplying the sample fluid; (b) a second container for storing sheath fluid and having a supply port for supplying the sheath fluid; (c) a flow cell having a sample fluid inlet for receiving sample fluid supplied from the supply port of the first container, a sheath fluid inlet for receiving the sheath fluid from the supply port of the second container, and an outlet for discharging the mixture of the sheath fluid and the sample fluid; (d) a first pump for supplying a sheath fluid to the sheath fluid inlet; (e) a second pump for suctioning fluid within the flow cell through the outlet of the flow cell; (f) a first drive source for driving the first pump and second pump; (g) a light source for irradiating with light the sample fluid in the flow cell; (h) detection unit for detecting optical information from the sample fluid; and (i) analysis unit for analyzing the detected optical information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the flow system and optical system of an embodiment of the sample analyzer;
FIG. 2 shows the essential structure of the embodiment of the sample analyzer;
FIG. 3 is a block diagram of the control system of the embodiment of the sample analyzer;
FIG. 4 is a timing chart showing the test result of the embodiment of the sample analyzer;
FIG. 5 is a timing chart showing the test results of the embodiment of the sample analyzer; and
FIG. 6 shows the flow system of a modification of the embodiment of the sample analyzer.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the sample analyzer of the present invention are described hereinafter based on the drawings. In the following embodiments, a particle image analyzer is described as an example of the sample analyzer of the present invention. The present invention is not limited to the given examples.
Flow System and Optical System of the Particle Image Analyzer
FIG. 1 shows the flow system and optical system of an embodiment of the sample analyzer of the present invention.
As shown in FIG. 1 , a sheath flow cell FC is provided with a sheath fluid inlet 1 , sample fluid inlet 2 , and outlet 3 for discharging the mixture of the sheath fluid and sample fluid. A sample container C 1 stores sample fluid through an open top, and an outlet provided in the bottom part is connected to a sample fluid inlet 2 through a flow path. An electromagnetic valve (hereinafter referred to as “valve”) SV 1 is provided in the flow path between the outlet of the sample container C 1 and the sample fluid inlet 2 . Furthermore, a mixing device 12 is provided for mixing the sample fluid within the sample fluid container C 1 .
A syringe pump CL 1 has a discharge port 4 , and a sheath fluid supply port 5 . The discharge port 4 is connected to the sheath fluid inlet 1 of the sheath flow cell EC through a flow path. A valve SV 4 is provided in the flow path between the discharge port 4 and the sheath fluid inlet 1 . A sheath fluid container C 2 stores sheath fluid in its interior, an outlet provided in the bottom part of the container is connected to a sheath supply port 5 through a flow path. A valve SV 6 is provided in the flow path between the outlet of the sheath fluid container C 2 and the sheath fluid supply port 5 .
A syringe pump CL 2 is provided with a suction port 5 a , and a syringe pump CL 3 is provided with two suction ports 6 , and a sheath fluid supply port 7 . The discharge port 4 a of the syringe pump CL 2 is connected to the suction port 6 of the syringe pump CL 3 .
The outlet 3 of the sheath flow cell FC is connected to the suction port 5 a of the syringe pump CL 2 through a flow path, and is connected to the opening on the open top part of the discharge fluid container C 3 . Valves SV 2 and SV 5 are provided in the flow path between the outlet 3 and the suction port 5 a . Valves SV 2 and SV 3 are provided in the flow path between the outlet 3 and the opening of the discharge fluid container C 3 .
The sheath fluid supply port 7 of the syringe pump CL 3 is connected to the outlet of the sheath fluid container C 2 . A valve SV 7 is provided in the flow path between the sheath fluid supply port 7 and the outlet of the sheath fluid container C 2 .
The syringe pumps CL 1 and CL 2 are driven in linkage with a single first drive source 8 , and the syringe pump CL 3 is driven by a second drive source 9 . The first drive source 8 is provided with a stepping motor SM 1 , and a transmission mechanism 10 for converting the rotational movement of the motor SM 1 to linear movement and transmitting the linear movement to the syringe pumps CL 1 and CL 2 . The transmission mechanism 10 includes a drive pulley attached to the drive shaft of the stepping motor SM 1 , and a driven pulley about which is reeved a timing belt, and converts the rotational movement of the stepping motor SM 1 to linear movement.
The second drive source 9 is provided with a stepping motor SM 2 , and a transmission device 11 for converting the rotational movement of the stepping motor 2 to linear movement and transmitting the linear movement to the syringe pump CL 3 . The transmission mechanism 11 includes a drive pulley attached to the drive shaft of the stepping motor SM 2 , and a driven pulley about which is reeved a timing belt, and converts the rotational movement of the stepping motor SM 2 to linear movement.
Furthermore, A light source LS for irradiating with light the sample fluid flow which is severely constricted as it is surrounded in the sheath fluid, and an objective lens OL and CCD camber VC for imaging the particles in the sample fluid flow are provided in the sheath flow cell FC. The light source LS is a strobe lamp.
Syringe Pump and Drive Source Structures
FIG. 2 shows details of the structure of the first drive source 8 shown in FIG. 1 . As shown in the drawing, the syringe pumps CL 1 and CL 2 have the same structure and dimensions, and are fixedly attached to the surface of a support plate 13 in series and in mutually opposing directions. The syringe pump CL 1 is provided with a cylinder 14 , piston 15 the tip of which is inserted into the cylinder 14 , packing 16 for providing an airtight seal of the gap between the cylinder 14 and piston 15 , discharge port 4 , and nipples 17 and 18 respectively provided at the sheath fluid supply ports 5 .
Furthermore, the syringe pump CL 2 is provided with a cylinder 14 a , piston 15 a the tip of which is inserted into the cylinder 14 a , packing 16 a for providing an airtight seal of the gap between the cylinder 14 a and piston 15 a , discharge port 4 a , and nipples 17 a and 18 a respectively provided at the suction ports 5 a . The pistons 15 and 15 a have mutually identical diameters.
The respective back ends of the pistons 15 and 15 a are linked by a linkage 19 such that both have the same axis. The stepping motor SM 1 is fixedly attached to the back surface of the support plate 13 such that the output shaft of the motor extends from the surface of the support plate 13 , and an output shaft drive pulley PL 1 is provided.
Furthermore, a corresponding driven pulley PL 2 is provided on the front surface of the support plate 13 , and a timing belt TB is reeved between the drive pulley PL 1 and the driven pulley PL 2 so as to be tensioned parallel to the pistons 15 and 15 a . The timing belt TB and linkage 19 are connected by a connecting member CM.
When the stepping motor SM 1 rotates, the connecting member CM moves linearly in the axial direction (arrow A or arrow B direction) of the pistons 15 and 15 a by the timing belt TB. That is, the drive force and driven pulley PL 1 , PL 2 , and the timing belt TB from a transmission mechanism for converting the rotational movement of the stepping motor SM 1 to linear movement in the arrow A or arrow B direction, and transmit the this linear movement to the syringe pumps CL 1 and CL 2 at the same time.
When the pistons 15 and 15 a move in the arrow A direction, the syringe pump CL 1 performs a discharge operation, and the syringe pump CL 2 performs a suction operation. When the pistons 15 and 15 a move in the arrow B direction, the syringe pumps CL 1 and CL 2 performs the respectively opposite operations.
Control System
FIG. 3 is a block diagram of the control system of the sample analyzer shown in FIG. 1 . A personal computer 20 is provided with an image processing unit 21 for acquiring image signals from a CCD camera VC and performing image processing to generate particle image data, analysis unit 22 for recognizing the particles from the particle shape and coloration, counting the particles and statistically analyzing the particles, and control unit 23 for controlling a driver circuit unit 24 . The analysis result of the analysis unit 22 is output from an output unit 25 . The driver circuit unit 24 , which is controlled by the control unit 23 , is provided with driver circuits for the valves SV 1 through SV 7 , stepping motors SM 1 and SM 2 , and light source LS, respectively. The output unit 25 is a CRT. The driver circuit which drives the light source LS is controlled such that the light source LS emits light at predetermined periods.
Analysis Operation
The analysis operation of the sample analyzer having the previously described structure is described below.
In FIG. 1 , the syringe pump CL 1 is set in the state in which the piston 15 is drawn from the cylinder 14 (discharge operation enabled state), and the syringe pump CL 2 is set in the state in which the piston 15 a is pushed into the cylinder 14 a (suction operation enabled state). Furthermore, the syringe pump CL 3 is also set in the state in which the suction operation is enabled.
Then, the valves SV 2 , SV 3 , SV 4 , and SV 6 are opened.
Since a positive pressure is applied beforehand to the sheath fluid container C 2 , the sheath fluid is discharged from the container C 2 to the discharge fluid container C 2 through the valve SV 6 , syringe pump CL 1 , valve SV 4 , sheath flow cell FC, and valves SV 2 and SV 3 .
Then, the valves SV 2 , SV 3 , SV 4 , and SV 6 are closed.
In this way the sheath fluid is loaded into the syringe pump CL 1 .
Then, the valves SV 3 , SV 5 , and SV 7 are opened.
The sheath fluid is discharged from the container C 2 to the discharge container C 3 through the valve SV 7 , syringe pump CL 3 , syringe pump CL 2 , and valves SV 5 and SV 3 .
Then, the valves SV 3 , SV 5 , and SV 7 are closed.
In this way the sheath fluid is loaded into the syringe pumps CL 2 and CL 3 .
Then, the valves SV 1 , SV 2 , SV 4 , and SV 5 are opened, the stepping motors SM 1 and SM 2 are driven, and the syringe pump CL 1 performs an operation of discharging a flow quantity Q, the syringe pump CL 2 performs an operation of suctioning a flow quantity Q, and the syringe pump CL 3 performs an operation of suctioning a flow quantity Qs.
In this way a flow quantity Q of sheath fluid flows from the syringe pump CL 1 to the sheath flow cell FC, and a flow quantity Qs of sample fluid also flows from the sample container C 1 into the sheath flow cell FC. After the sample fluid is converted to a narrow sample fluid flow surrounded in a sheath fluid flow in the sheath flow cell FC, the mixed fluid of the flow quantity (Q+Qs) mixed with the sheath fluid is discharged from the sheath flow cell FC.
Within the discharged mixed fluid, a mixed fluid of flow quantity Q is suctioned by the syringe pump CL 2 , and a mixed fluid of flow quantity Qs is suctioned by the syringe pump CL 3 .
At this time, the sample fluid flow formed in the sheath flow cell FC is irradiated by light emitted from the light source LS, and the particles contained in the sample fluid are imaged by the CCD camera VC.
The personal computer 20 shown in FIG. 3 receives the imaging signals from the CCD camera VC and subjects the signals to image processing, recognizes the type and number of particles based on the obtained particle image and performs statistical analysis, and outputs the analysis result to the output unit 25 .
Sample Fluid Flow and Stability
The following tests were conducted to confirm the stability of the sample flow quantity relative to changes in the flow quantity of the sheath flow in the particle image analyzer of the present embodiment.
In FIG. 1 , with the valves SV 1 , SV 2 , SV 4 , and SV 5 in the open state, the syringe pump CL 1 was driven by the first drive source 8 , and the second syringe pump CL 2 was independently drive by the third drive source which is independent from the first drive source 8 , and the flow quantity of the syringe pump CL 1 was periodically changed by the first drive source 8 .
In FIG. 1 , at this time the change over time of the flow quantity Q at point P 1 in the flow path between valve SV 4 and the discharge port of the syringe pump CL 1 is shown in part (a) of FIG. 4 .
Furthermore, the change over time of the flow quantity Q at point P 2 in the flow path between valve SV 5 and the suction port 5 a of the syringe pump CL 2 is shown in part (b) of FIG. 4 . Finally, the change over time of the flow quantity Q at point P 3 in the flow path between valve SV 1 and the sample fluid inlet 2 is shown in part (c) of FIG. 4 .
As shown in part (a) of FIG. 4 , the flow quantity Q at point P 1 changed about a center of 100 mL/sec with an amplitude of 1 mL/sec and a period of 4 sec.
The flow quantity at point P 2 held constant at 100 mL/sec, as shown in part (b) of FIG. 4 .
The flow quantity Q at point P 3 changed about a center of 100 mL/sec with an amplitude of 1 mL/sec and a period of 4 sec, as shown in part (c) of FIG. 4 .
That is, when the flow quantity of either of the syringe pumps CL 1 or CL 2 changes, the flow quantity Q of the sample fluid is changed only by the amount of the change in the flow quantity. Thus, it can be understood that when the flow quantity of the sheath fluid changes by 0.5%, the flow quantity of the sample fluid changes by ±50%.
In contrast, the syringe pumps CL 1 and CL 2 were driven by the same drive source 8 , and the flow quantities of the syringe pumps CL 1 and CL 2 changed simultaneously via the drive source 8 , as in the specification of the present invention. In this case, the results corresponding to parts (a), (b), and (c) of FIG. 4 are shown in parts (a), (b), and (c) of FIG. 5 .
The flow quantity Q at points P 1 and P 2 changed about a center of 100 mL/sec with an amplitude of 1 mL/sec and a period of 4 sec, as shown in parts (a) and (b) of FIG. 5 .
In this case, the flow quantity Q at point P 3 held constant at 100 mL/sec, as shown in part (c) of FIG. 5 .
That is, since the syringe pumps CL 1 and CL 2 are driven by a single drive source 8 in the present invention, even if the flow quantities of the syringe pumps CL 1 and CL 2 change via a change by the drive source, the change is mutually equal for both, such that the flow quantity of the sample fluid flow remains constant.
Furthermore, since the open topped sample fluid container can be connected to the sample fluid inlet of the sheath flow cell, a mixing device can be inserted so as to easily perform the mixing and dispersion operation of the sample even when the specific gravity of the particles is large and the particles readily precipitate in the sample fluid.
In the above embodiment, analysate particles include tangible components such as are contained in body fluids of humans and lactating animals, organic powders such as food additives, and inorganic powders such as toner and pigments.
Although the rotational movement of the stepping motors is converted to linear movement by a timing belt in the above embodiment, the rotational movement of the stepping motor also may be converted to linear movement by a ball screw or wire.
Although the light source in the above embodiment is a strobe lamp, a white light source, laser light source or the like also may be used. Furthermore, although the strobe lamp is controlled by a driver circuit so as to emit light at a predetermined period, the strobe lamp also may be controlled for continuous light emission via the driver circuit.
A CCD camera is used in the above embodiment imaging particles to detect particles in the sample fluid, however, a camera such as a video camera, or light sensor such as a photodiode, phototransistor, photomultiplier tube and the like also may be used.
The present invention has been described using an example when applied to a particle image analyzer in the above embodiment, however, the present invention is not limited to this example, inasmuch as the present invention also may be applied to flow cytometers which optically or electrically measure various types of particles having diameters from the submicron level to several hundred micron level.
A modification of the above embodiment is described below in an example using a syringe pump CL 4 which has a diameter larger than the syringe pump CL 1 , and which replaces the syringe pump CL 2 and syringe pump CL 3 , as shown in FIG. 6 . In FIG. 6 , the piston of the syringe pump CL 4 has a diameter which is larger than the diameter of the piston of the syringe pump CL 1 , and the syringe pumps CL 1 and CL 4 are driven in linkage by a single drive source 8 . In other aspects the construction is identical to that of FIG. 1 . In this modification, the stepping motor SM 1 is driven, and the syringe pump CL 1 performs an operation to discharge a flow quantity Q and the syringe pump CL 4 performs an operation to suction a flow quantity (Q+Qs), such that the difference in the flow quantities of the syringe pump CL 1 and the syringe pump CL 4 is the constant suction quantity Qs.
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The sheath flow forming device includes: a container for storing sample fluid and having a supply port for supplying the sample fluid; a second container for storing sheath fluid and having a supply port for supplying the sheath fluid; a flow cell having a sample fluid inlet for receiving sample fluid supplied from the supply port of the first container, a sheath fluid inlet for receiving the sheath fluid from the supply port of the second container, and an outlet for discharging the mixture of the sheath fluid and the sample fluid; a first pump for supplying a sheath fluid to the sheath fluid inlet; a second pump for suctioning fluid within the flow cell through the outlet of the flow cell; and a first drive source for driving the first pump and second pump.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention consists of a visual testing method for observing chromatic aberration between two optical devices. This testing method provides the tester of the optical devices with a noticeable and easily perceivable result that clearly distinguishes an optical device with lower chromatic aberration from that of an optical device with higher chromatic aberration. Furthermore, the test has been designed to allow the tester to distinguish the chromatic aberration properties of two optical devices that have only fine differences in chromatic aberration, such as the differences between ED (extra-low dispersion) and non-ED glass, which may not be visually noticeable in practice except for those highly trained and experienced in the optics field.
[0003] 2. Description of Related Art
[0004] Many optical devices that we use frequently involve the viewing of color: binoculars can be used for enjoyment when users look out over beautiful vistas, for education when bird watchers observe details of a bird's nesting habits, or for utility when hunters track their prey. In all these situations, many colors are input into the optical system, and the optical system has slightly different properties for each color, corresponding to a specific wavelength of light. The term for the variation of the properties of a lens when analyzing over different wavelengths or colors is known as chromatic aberration. Chromatic aberration results in a distortion of the image produced when viewing multi-colored objects through an optical lens, because the lens is unable to focus all colors to the same point. This difference in focal lengths is due to the variation of the index of refraction according to wavelength. As a result of the optical properties varying according to wavelength, red objects focus at different distances than blue objects.
[0005] There are numerous examples of complex optical systems or methods that are all aimed at the goal of reducing chromatic aberration, especially computerized systems or specific instrumentation that can measure the chromatic aberration in a system. The data measured is then either used to make corrections in the digital information or to specify how well a new design minimizes chromatic aberration. These methods involve complex and expensive instrumentation to determine chromatic aberration properties, especially aberrations that are not visually observable.
[0006] The computerized methods often use either a black circle or another dark shape on a white background. Chromatic aberration is shown in this case as a halo of color around the dark object, with different colors showing at different places around the circle corresponding to the different focal lengths of each wavelength. The computer can then extract the data through computation or the data can be received from the camera in an RBG or equivalent format, where the result is several circles of various colors each at a different offset location than the original black circle. Another method is to highlight a shape or pattern with different colored lights, one at a time, and then compare the recorded information. In regards to visual testing for chromatic aberration, current methods may include looking at objects around the tester, for example, a dark colored boat in the distance on a bright day. The problem is that all these types of testing methods become highly subjective when used as a visual testing method, so that the testing method becomes very inaccurate and useless in systems with low chromatic aberration or small differences in chromatic aberration. For example, in the case of a fairly well chromatically corrected optical system, a test such as the black circle will only produce an extremely thin color halo. The tester then would have to observe the difference in thickness of the halo compared to another device with another very thin border of color, which introduces too much human error. Clearly there is a need for the invention of a new testing method to provide a clear visual result to the tester without the need for computers or instrumentation, which can provide a more quantifiable result.
[0007] In regards to visual testing methods in general, there are examples of visual testing methods to measure other optical performance properties such as resolution or contrast, but no current visual testing method exists for chromatic aberration, which doesn't utilizing other equipment or instrumentation. Also, there has been use of visual charts that involve chromatic aberration but are based upon the exploitation of the existence of chromatic aberration, not the measuring or quantifying of the aberration. For example, one application is for use for optometrists or other health professionals, wherein colored charts or letters are presented to the individual who is being tested, as a means of gauging whether their eyeglasses or other lens correction has been adjusted accordingly. When the individual being testing sees a certain color focused more than another, it indicates to the optometrist that their prescription is either over-corrected or under-corrected. The chromatic aberration of the eyeglass is not being tested, just merely used as an indication if there is a need to adjust the focal length of the corrective device.
SUMMARY OF THE INVENTION
[0008] In accordance with a first embodiment of the invention, a method for visually testing the chromatic aberration in an optical device is provided. In this embodiment, the method utilizes a testing apparatus that has a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination thereof, and further wherein a tester is positioned at a distance away from the testing apparatus that is the same or greater than the minimum focal distance of the optical device being tested, wherein the method compromises the steps of viewing the testing apparatus through at least the optical device being tested, and visual observing the resulting image, either directly or indirectly by means of an imaging or projecting device; determining the degree of chromatic aberration based upon the number of distinctive objects viewed in a single test iteration, where two or more distinctive objects or features viewed corresponds to an optical device with low chromatic aberration, a partially merged object viewed corresponds to an optical device with medium chromatic aberration, and whereas only a single or merged object or feature viewed corresponds to an optical device with high chromatic aberration; and providing an assessment of the chromatic aberration based upon the determining step.
[0009] In another preferred embodiment of the invention, an apparatus for visually testing the chromatic aberration of an optical device is provided, which presents to the tester, a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination of those, on a background different from any of the two or more colors.
[0010] In yet another preferred embodiment of the invention, a testing chart is provided, which is a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination of those, on a background different from any of the featured colors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0012] FIG. 1 is an example of a test image illustrating a preferred embodiment of the testing method using strips of two colors. Upon viewing with an optical device that has high chromatic aberration, the strips appear to blend together, now perceived as a single strip of another color (in this example, purple). However, when viewed with an optical device with low chromatic aberration, each strip is distinguishable and distinct, compromised of one strip of the first color and one strip of the second color.
[0013] FIG. 2 demonstrates the use of the above embodiment in an array format, to allow for the tester to identify the specific point at which an optical device's chromatic aberration properties affect the image they are viewing. In this example, the tester will be able to identify certain strips whose colors remain distinct, whereas thinner strips will begin to merge in color as the device's chromatic aberration affects their view. The labeling of the array can be done in number units to provide a rating of chromatic aberration, or if calibrated for given set of testing parameters, the chart could be labeled with the Abbe number (or another preferred quantity) range for each iteration.
[0014] FIG. 3 is another example of a test image utilizing a shape made from two colors
[0015] FIG. 4 is similar to the previous embodiment but utilizing a color background
[0016] FIG. 5 shows the embodiment from FIG. 4 but in an array format as in FIG. 2 .
[0017] FIG. 6 depicts one example where a pattern may be hidden or distinguishable based upon the chromatic aberration of the optical device.
[0018] FIG. 7 depicts another example where a pattern may be hidden or distinguishable based upon the chromatic aberration of the optical device.
[0019] FIG. 8 shows an optical schematic displaying how the testing method in the above embodiments alters the testing object based on the chromatic aberration of the optical system into the testing image that is viewed by the tester.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The visual testing method outlined is for the measurement of chromatic aberration in a range of optical devices. A specific application of such a visual testing method is for use in binoculars and other optical systems, where chromatic aberration can be minimized through the use of lower dispersion optical materials such as, ED (Extra-low Dispersion) glass in the objective lens of a binocular. The indicator of chromatic aberration is measured by the Abbe number, where a higher value corresponds to lower dispersion so that the focal lengths for all colors are close together as opposed to far apart. ED glass has a higher Abbe number than non-ED glass, which indicates a lower level of dispersion. No visual testing method currently exists that can distinguish the two since their difference is so small that it is almost completely unperceivable to all but the highly trained eye. A typical consumer may not be able to notice any difference between the two types in a binocular. Since there is a significant price differential and a difference in value, it is apparent that a test to display the ability of ED glass to reduce chromatic aberration would make it easier for a customer to decide between two products.
[0021] This visual testing method for chromatic aberration is based upon two concepts. First, chromatic aberration in an optical device bends the higher wavelengths of light farther away from the optical axis while lower wavelengths of light stay closer to the optical axis. This is a result of the different focal lengths of the optical elements according to wavelength. Furthermore, if you take two differently colored objects at different heights from the optical axis—for example, a red object close to the optical axis and a blue object slightly more offset from the optical axis, the image of the red object will be higher from the optical axis than expected based upon commonly used geometrical optics theory which does not account for chromatic aberration. Additionally, the blue object will now be closer to the optical axis, thereby bringing the composite image of each object closer to each other than the original image as demonstrated by FIG.
[0022] The second concept is based on the human perception of colors. In the human eye there are rods and cones, and cones are primarily responsible for color vision. There are three types of cones that respond to different wavelengths of light with a peak sensitivity in the blue, green and red ranges. The brain takes this data and interprets the color based upon the relative strength of the input received from these three cones. In the example of a red object overlaid with a blue object, primarily only two of the three cones would be active, and the subject would perceive the result as a magenta or purple color.
[0023] Exploiting these two concepts simultaneously, the invention results in a more binary, more easily distinguishable testing method such that the tester can view a distinctly different result directly correlated to the chromatic aberration of the optical device. For example, when testing an optical device with low chromatic aberration, the tester would see two distinct objects, a blue and a red image, but when testing an optical device higher with a higher chromatic aberration, the two colors would appear as a single, merged colored image. The example is only indicative of a single application of the testing method, however many versions can be conceived using various colors, patterns and combinations thereof based upon these two key concepts that were uniquely combined and utilized in this visual testing method.
[0024] Combination of the two key concepts depends on the proper selection of the testing parameters based upon several variables depending on the optical device tested and the testing environment. The size of each feature must be in a certain range dependant on several factors, the distance the tester is away from the testing apparatus, the aperture or lens size, the magnifying power of the optical device, the ambient lighting conditions, etc. As the user's distance from the test apparatus decreases, the size of the strips must decreases. As the magnification of the device increases, the size of the strips must also decrease. Depending on the approximate level of chromatic aberration in the optical devices, the size of the features also has to be selected to have a range such that some are merged and some remain distinct. For example, for testing an ED and non-ED 8×42 roof binocular in typical indoor lighting conditions, at a preferred distance of 70 feet, the testing feature size should range from at least 0.07 inches to 0.1 inches in width.
[0025] One of the benefits of this visual testing method is that even an untrained tester can detect small differences in chromatic aberration between optical devices, as well as see some chromatic aberration visually in optical systems that can otherwise be difficult to detect. Another significant benefit of this technique is its ability for the tester to visually distinguish the difference in chromatic aberration, when comparing ED and non-ED glass. In the field, the lower chromatic aberration in ED glass may be the difference between accurately viewing a colored stripe on the wing of a bird and therefore accurately identifying it, and seeing an incorrect color and therefore misidentifying.
[0026] The preferred embodiment of this test is a white background with a strip or an array of strips divided vertically, half red and half blue. The strips increase in width in each iteration. When viewed through an optical product with low chromatic aberration such as ED glass, the strips of color remain distinct, down to the thinnest strips. When viewed through an optical product with higher chromatic aberration such as non-ED glass, the strips of color begin to merge as the strips decrease in width. This clearly displays the higher tendency toward chromatic aberration present in non-ED glass.
[0027] Another preferred embodiment is strips of color that comprise red and yellow or blue and yellow.
[0028] Another preferred embodiment places these strips on a background that is gray or black in color.
[0029] Another preferred embodiment instead utilizes shapes, with two colors filling in the shape in a pattern.
[0030] Another preferred embodiment utilizes a letter, such as the letter C, comprised of two strips of color, decreasing in size and placed in a line.
[0031] Another preferred embodiment shows a distinguishable image utilizing two or more colors, where in the low chromatic aberration case the image is distinguishable, but in the high chromatic aberration case, the image is lost or hidden.
[0032] Therefore, in accordance with a preferred embodiment of the invention, a method for visually testing the chromatic aberration in an optical device is provided. In this preferred embodiment, the method utilizes a testing apparatus that has a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination thereof, and further wherein a tester is positioned at a distance away from the testing apparatus that is the same or greater than the minimum focal distance of the optical device being tested, and the method comprises the steps of: viewing the testing apparatus through at least the optical device being tested, and visual observing the resulting image, either directly or indirectly by means of an imaging or projecting device; determining the degree of chromatic aberration based upon the number of distinctive objects viewed in a single test iteration, where two or more distinctive objects or features viewed corresponds to an optical device with low chromatic aberration, a partially merged object viewed corresponds to an optical device with medium chromatic aberration, and whereas only a single or merged object or feature viewed corresponds to an optical device with high chromatic aberration; and providing an assessment of the chromatic aberration based upon the determining step.
[0033] In some specific embodiments, the method may include the steps of repeating the viewing, determining and providing steps for comparing the relative chromatic aberration in two or more optical devices. In another embodiment, the providing step results in a rating for the optical device based upon the results of the determining step.
[0034] Additionally and/or alternatively, the optical device is provided that was designed to incorporate optical elements with different chromatic aberration, so that the user can compare the chromatic aberration between different optical materials. Moreover, the optical products compared are preferably but not necessarily binoculars with the same size objective lenses and the same overall magnification.
[0035] In accordance with preferred embodiments, the testing device preferably uses color pairings are separated by more than 150 nanometers, in preferred embodiments, such as red and blue, yellow and violet, or red and yellow. The testing device also preferably utilizes colors that are beside one another in close proximity in strips of equal length and width. Preferably, the testing device utilizes color strips arranged in an array with each iteration increasing in thickness. The testing device could also preferably utilize color strips set on a white or other color contrasting background (black, grayscale, or a color different from the color of the strips). The testing device's colors are also preferably utilized so that a pattern, such as a letter, number, or shape, is clearly distinguishable using a optical device with a low chromatic aberration, and undistinguishable in an optical device with a high chromatic aberration.
[0036] In another preferred embodiment, an apparatus for visually testing the chromatic aberration of an optical device is provided. In this preferred embodiment, the apparatus presents to the tester a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination of those, on a background different from any of the two or more colors.
[0037] In specific embodiments, the optical products compared are preferably but not necessarily binoculars with the same size objective lenses and the same overall magnification. Similarly, the testing device preferably uses color pairings are separated by more than 150 nanometers, in preferred embodiments, such as red and blue, yellow and violet, or red and yellow. The testing device may also preferably utilize colors that are beside one another in close proximity in strips of equal length and width. Alternatively, the testing device may utilize color strips arranged in an array with each iteration increasing in thickness. Moreover, the testing device may utilize color strips set on a white or other color contrasting background (black, grayscale, or a color different from the color of the strips). Preferably, the testing device's colors are utilized so that a pattern, such as a letter, number, or shape, is clearly distinguishable using a optical device with a low chromatic aberration, and undistinguishable in an optical device with a high chromatic aberration
[0038] In yet another preferred embodiment, a testing chart is provided, which is a representation of at least two or more colors denoted by their wavelength, such that each color utilized is separated by no less than 75 nanometers in wavelength, and where each color is set beside another in close proximity, in a pattern, shape, or letter, or any combination of those, on a background different from any of the featured colors. In a preferred embodiment, the testing chart uses color pairings are separated by more than 150 nanometers, in preferred embodiments, such as red and blue, yellow and violet, or red and yellow. The testing device may utilize colors that are beside one another in close proximity in strips of equal length and width. The testing device may utilize color strips arranged in an array with each iteration increasing in thickness. Moreover, the testing device preferably utilizes color strips set on a white or other color contrasting background (black, grayscale, or a color different from the color of the strips). The testing device's colors may also be utilized so that a pattern, such as a letter, number, or shape, is clearly distinguishable using a optical device with a low chromatic aberration, and undistinguishable in an optical device with a high chromatic aberration.
[0039] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions and methodologies without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. It should also be understood that the following claims are intended to cover all of the generic and specific features of the invention described herein and all statements of the scope of the invention that as a matter of language might fall therebetween.
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This invention comprises a method of visually comparing the chromatic aberration in two or more optical devices. The test reveals differences in the ability of an optical product to minimize chromatic aberration, so that ideally, various colors (corresponding to specific wavelengths) will have a sharp focus at almost the same distance away from the last optical element. The method provides a consistent way to test the chromatic aberration in various optical products that is more visually observable than the process of noting the halo of colors that appears along the edge of a dark object on a light background. The test is especially geared toward comparing binoculars with different optical material composition such as ED glass (Extra-low Dispersion) or FL (Fluorite) glass to those with conventional types of glass.
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TECHNICAL FIELD
[0001] This invention relates to arrangements for controlling telecommunications calls from customer premises equipment.
BACKGROUND OF THE INVENTION
[0002] In the telecommunications field, there are many arrangements available for directing calls to an appropriate destination within a group of associated destinations. In most cases, a computer is used to direct incoming calls, received with an identity of a caller, to the most appropriate destination. One such system is described in Gechter et al.: U.S. Pat. No. 5,036,535, issued Jul. 30, 1991.
[0003] A problem with such systems is their high expense. In many cases, a digital connection is required between the system and a serving central office switch; this limits the distance between the system and a serving central office.
SUMMARY OF THE INVENTION
[0004] The above problem is alleviated in accordance with this invention wherein the customer premises equipment comprises a single data line for transmitting either analog data or voice and one or more conventional (Plain Old Telephone Services (POTS)) lines. Calls may be received in either the data/voice station or one of the POTS stations depending on the number called by the caller. If the call is for the number associated with one of the POTS stations, the call is not completed until a query has been made by the serving switch to the control station and the data station has generated a response for completing the call to the initial station, completing the call to another telephone number, or rejecting the call. The service is used in conjunction with incoming caller line identification so that the data station can use the identity of the caller to decide whether to accept the call at the dialed station, redirect the call to another station, or reject the call. Advantageously, only the control station connected to the data line needs to have an intelligent station. Advantageously, inexpensive voice band analog signaling arrangements can be used between the control station and the switch, e.g., dual tone multifrequency (DTMF) or frequency shift keying (FSK).
[0005] In accordance with one preferred embodiment, the data line and therefore the control intelligent station is informed whenever one of the other stations makes a call. For outgoing calls the intelligent station can block the calls, redirect the outgoing call to another telephone number, disconnect a call if a time threshold is exceeded, and, if desired, notify the caller. On these outgoing calls and incoming calls, the station associated with the data line can accumulate usage statistics and statistics concerning calling and called numbers for each of the POTS stations. Advantageously, this arrangement allows for monitoring and control of the POTS lines at very low cost.
[0006] In one embodiment, responsive to receipt of a call for the control station connected to the data line, the call can be redirected to one of the other stations. For such calls, the control station can request that the switch apply a distinctive ring. The call to the control station can also be automatically forwarded to another station if the call is not answered before the lapse of a predetermined interval. The control station's telephone number is, preferably, unpublished.
[0007] In accordance with one preferred embodiment of Applicants' invention, each of the POTS lines has a pointer to the data line and the data line has a linked list of the POTS lines which it controls. The data station keeps track of which POTS stations are connected to which telephone numbers both in order to maintain traffic statistics and in order to route incoming calls to an alternate station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram illustrating the operation of Applicants' invention;
[0009] FIG. 2 is a flow diagram illustrating the process of handling an outgoing call from one of the POTS stations;
[0010] FIG. 3 is a flow diagram illustrating the process of handling an incoming call to one of the POTS lines; and
[0011] FIG. 4 is a flow diagram illustrating the process of handling an incoming call for the number of the data line.
DETAILED DESCRIPTION
[0012] FIG. 1 is a block diagram illustrating the operation of Applicants' invention. A control station 1 comprises means for transmitting and receiving data messages 6 and a computer 5 , such as a personal computer (PC), for interpreting incoming messages and generating outgoing messages. One or more POTS can exist, limited only by the messaging bandwidth of the control station. In FIG. 1 , two POTS stations ( 2 and 3 ) are shown. The control station and the POTS stations are connected to a switch 30 . The control station is connected to a control port 11 and POTS station 2 is connected to POTS port 12 . The switch includes a switching network 31 and a control processor system 32 . The control processor system controls processes 21 and 22 which are associated with control ports 11 and 12 , respectively. The switching network 31 is also connected to the public switched telephone network 33 which is connected to caller station 41 and called station 42 .
[0013] The control station uses voice band analog signaling (frequency shift keying (FSK) or dual tone multifrequency (DTMF)) to communicate with switch 30 .
[0014] FIG. 2 is a flow diagram illustrating the processing of an outgoing call from one of the POTS stations. The POTS station 2 sends dialing information to POTS port 12 (action block 201 ). POTS port 12 is associated with an enhanced POTS process 22 , which process sends a query message via control process 21 and control port 11 to control station 1 (action block 203 ). The query includes the identity of POTS station 2 and the dialed information. Control station 1 examines the contents of the query and generates a response message which is transmitted via control port 11 and control process 21 to POTS process 22 (action block 205 ). POTS process 22 examines the contents of the response message and performs one of a number of actions such as:
[0015] 1. completing the call as dialed from POTS port 12 to a called station 42 ;
[0016] 2. reroute the call to an alternative number;
[0017] 3. block further action on the call (action block 207 ).
[0018] If the call is completed, then POTS process 22 notifies control station 1 of the completion of the call of the time that the called station answers and of the disconnect time of the call. This information is used by control station 1 to route calls only to an available POTS station and to accumulate statistics about call usage by POTS station 2 (action block 209 ). If POTS station 2 is allowed to complete the call but is not allowed to call the called station for more than a predetermined length of time, then the control station transmits messages to cause a tone to be applied to POTS station 2 some time, such as 15 seconds, before the limit is reached; if POTS station 2 has not yet disconnected when the time limit is reached, the control station sends another message to cause a disconnect when the maximum time is reached.
[0019] All control messages are sent by switch under a guard timer. If there is no reply (e.g., control station down) then the switch proceeds to complete the call in a default manner by ringing the dialed number if idle.
[0020] For reliability, the switch periodically sends a timed busy/idle status refresh of all POTS stations to the control station in the event the control station was offline for some time (e.g., computer malfunction). Control station could also request this by dialing a special reserved control DN on the switch.
[0021] For calls with no caller identification or suppressed caller identification, special treatment such as an announcement can be provided.
[0022] The call treatment can be made a function of the time of day and/or day of the week, so that, for example, calls outside business hours can be routed to voice mail.
[0023] For calls to a busy POTS station which has call waiting service, a distinct call waiting tone can be provided under the control of the control station. Alternatively or in addition, all calls to the busy station except priority calls can be sent to busy tone.
[0024] For calls for which no further control messages are received by the switch, the switch can itself provide default treatment such as routing to voice mail after a timeout in ringing.
[0025] FIG. 3 is a flow diagram illustrating the processing of an incoming call to a POTS line. A call, including an incoming caller line identifier, is accepted in switch 30 (action block 301 ) and if the called station 2 is idle, a process 22 is created (action block 303 ). A query is sent (action block 305 ) from POTS process 22 to control process 21 to control port 11 and thence to control station 1 . The control station responds with a message which is sent via control port 11 and control process 21 to the POTS process 22 (action block 307 ). The message calls for one of a number of actions:
[0026] 1. attempt to complete as dialed by attempting to complete the call from POTS port 12 to POTS station 2 ;
[0027] 2. redirect the call to an alternative station identified by an alternative telephone number; or
[0028] 3. block the call and send busy tone or an announcement to the caller.
[0029] The attempted call completion may be done with distinctive ringing applied from the serving switch in response to a message from the control station. If the attempted call is not completed within x seconds, then another query is sent to the control station 1 , which may provide a new call routing, may simply allow the call not to be completed, or route the call to a voice mail number stored in the switch.
[0030] FIG. 4 is a flow diagram illustrating the processing of an incoming call to the control station. The call is received in the serving switch (action block 401 ) and switched through switching network 31 to control port 11 (action block 403 ) and a query is sent from control port 11 to control station 1 (action block 405 ). Based on the response to that query which is sent to the control port 11 (action block 407 ) and thence to the control process 21 , the call may be redirected to one of the POTS phones or may simply be completed via the data line to control station 1 (action block 409 ).
[0031] The database 23 of the control processor system 32 contains the data which allows the control process 21 to identify the control port 12 and vice versa. The data for control port 11 includes a linked list of the identities of all the POTS ports associated with control port 11 and the data for POTS port 12 includes the identity of the control port 11 . This allows the control process 22 to respond to an incoming call by identifying the control port 11 and its associated control process 21 . If the control station wishes to reroute an incoming call to another POTS port, the identities of all the POTS ports are stored in a linked list in the database 23 .
[0032] An arrangement wherein one control station serves a single POTS station is desirable when the control station is used primarily for computer access (e.g., ISP). If V.92 is used between the computer and ISP, the busy call can be given call waiting treatment; the control station can then send a brief set of call completion instructions. This can be useful at night to screen all but a selected group of priority business callers, while sending other callers to voice mail. It can also be useful for applying distinctive ringing signals, selected by the control station, to alert a user of the POTS station as to the type of caller.
[0033] The control station 1 can update the database 23 , for example, to change routing among the POTS stations. For example, if POTS station 3 is not to receive any calls not dialed directly to the number of that POTS station, the database 23 can be modified by a message from control station 1 to eliminate alternate routing to that station. This would be done in response to an FSK or DTMF message sent from control station 1 to switch 30 .
[0034] The control station 1 can keep call logs for all of the POTS stations and for itself. This allows system administrators to monitor the performance of agents staffing the individual POTS lines.
[0035] When the control station sends an incoming call to a voice messaging system (not shown), it can send a request to the control processor system 32 to send a message to the appropriate POTS station to turn on a message waiting lamp.
[0036] The above description is of one preferred embodiment of Applicants' invention. Other embodiments will be apparent to those of ordinary skill in the art without departing from the scope of the invention. The invention is limited only by the attached claims.
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A method and apparatus for providing control and monitoring of a group of plain old telephone service (POTS) stations from one control station. Incoming calls to the POTS stations are intercepted and the data describing the call is sent to the control station. The control station then provides directions for blocking the call, completing the call to the original POTS destination, or completing the call to another POTS destination. Outgoing calls are also monitored so that the control station maintains an up to date record of which stations are busy and which stations are idle. Advantageously, the control station communicates with the switch serving these POTS stations by analog signals (FSK) and/or DTMF thus overcoming the limitations on distance requirements for digital signaling.
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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for monitoring, preferably arrival monitoring, of the weft, e.g. the weft thread, in a loom of substantially the type in which the weft is driven through the shed with the aid of a jet, preferably a gas jet, e.g. an air jet, and which has a reed which is constructed from a number of lamellae disposed vertically with spacing, and which is pivotal between a first position and a second position and has a longitudinal channel for the weft.
Prior art arrival indicators suffer from an unreliable function which manifests itself primarily in many error signals and in many missed actual error trigger situations. These problems are accentuated particularly in air powered looms, so-called jet looms, which are extraordinarily quick and operate at high speeds such as 20 picks per second, in which event the arrival sensing must be executed during approximately 10-15 per cent of a complete machine cycle (5 per cent of the revolution). This naturally places extreme demands on the indicator itself and the associated electronics, in particular as regards sensitivity and speed. A major inconvenience in prior art arrival indicators is a very high degree of wear, which necessitates replacement of the indicator after short operational lives such as one month.
SUMMARY OF THE INVENTION
The task forming the basis of the present invention is to obviate the drawbacks inherent in prior art arrival indicators to as high a degree as possible.
The present invention realizes an arrival indicator which, with great reliability, may be employed in the most rapid jet looms or air powered looms in that the weft thread is sensed not only during a single instant of time but during a given period of time. This affords: in addition, an effective possibility to distinguish between the passage of some other foreign matter than a weft thread and the presence of the weft thread proper, whereby the risk of confusion is precluded. The apparatus according to the present invention further makes possible monitoring of whether an excessively long weft thread has been blown through the woven fabric and the end has become more or less jumbled at the edge of the fabric. Moreover, the apparatus according to the present invention permits sensing of such threads as have hitherto not been possible to sense in prior art optical indicators, e.g. non-reflective threads. An apparatus according to the present invention will not be subjected to any major degree of wear, whereby the service life of an apparatus according to the present invention has been greatly extended. It is also possible to employ the apparatus according to the present invention for controlling the air emission in the loom, since the indicator or the apparatus according to the present invention sees the entire channel or homogeneously into the entire channel and it thereby becomes possible to establish the exact arrival time of the thread with a very high degree of accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described in greater detail hereinbelow, with particular reference to the accompanying Drawings. FIG. 1 schematically illustrates a vector diagram of a machine cycle. FIG. 2 is a side elevation of a reed with an apparatus according to the present invention in different positions during a machine cycle. FIG. 3 is a side elevation of a part of an apparatus according to the present invention. FIG. 4 shows a section taken along the line A--A in FIG. 3. FIG. 5 shows a section taken along the line B--B in FIG. 3. FIG. 6 shows a section taken along the line C--C in FIG. 3. FIG. 7 is a side elevation of the part illustrated in FIG. 3 seen from the opposite side. FIG. 8 is a front elevation of the part of an apparatus according to the present invention illustrated in FIG. 3. FIG. 9 is a schematic diagram of a part of the electronic circuitry in which an apparatus according to the present invention is included. FIG. 10 is a side elevation of a reed with an apparatus according to another embodiment of the present invention. FIG. 11 is a view from the left in FIG. 10 of a part of the apparatus according to the present invention. FIG. 12 shows a section taken along the line XII--XII in FIG. 11. FIG. 13 shows a section taken along the line XIII--XIII in FIG. 11.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of an apparatus according to the present invention will be described more closely hereinbelow in connection with a jet loom or air powered loom. Such looms are well known in the art and will not, therefore, be described in-depth here, but only those parts which are directly related to the apparatus according to the present invention will be described in detail. These parts are shown in greater detail in FIG. 2 and consist of a reed which includes a relatively large number of lamellae 1 which are disposed upstanding and with spacing on a beam 2. The upper ends of the lamellae 1 are secured in a U-shaped rail 3 and the lower ends of the lamellae 1 are secured in a U-shaped rail 4. The pack consisting of the lamellae 1 and the rails 3 and 4 is positioned with the U-shaped rail 4 in a groove 5 in the beam 2 and is clamped in the groove 5 with the aid of one or more keys or wedges 6. Warp threads (not shown) extend in the space between the lamellae 1 and together with a plurality of weft threads (not shown) form a woven fabric (not shown).
FIGS. 1 and 2 illustrate more closely a machine cycle or a machine revolution and the movements of the parts in question during one such machine cycle or one such machine revolution. From the start of a machine cycle at "A" or 0°, the reed moves as illustrated in FIG. 2 slowly to position I or "B". The degree division of a machine cycle described herein is merely by way of exemplification and other degree divisions can be applied in different types of machines. On inserting the weft thread with the aid of an air jet, it will be located in the channel 7 formed in the lamellae 1 at least at the end of its path of movement or at the fabric edge where it is desirable to establish the presence or arrival of the weft thread, for which reason an apparatus according to the present invention is placed at this point, as is apparent in FIG. 2.
That point in time at which the weft thread occurs in the channel 7 behind the free end of an arm 8 is not predeterminable to 100 per cent but should occur between the positions "B" and "C" in FIGS. 1 and 2. These positions may vary from loom to loom and are dependent upon manufacture and settings, for which reason no determined degree figure therefore is given here. During the period of time from position "B" to "C", the reed is in motion from position I to II (FIG. 2). After position "C", it is considered to be too late for a normal arrival of the weft thread, since the reed in this position has approached too close to the fabric edge. The apparatus according to the present invention is to monitor or check that the weft thread is located in the channel 7 and thereby between the free end of the arm 8 and the rear edge or bottom of the channel 7 in the period of time between positions "B" and "C".
The machine cycle naturally controls the apparatus according to the present invention and is synchronized with some type of sensor, for example an inductive or optical sensor which is coupled to the loom in such a manner that a "flag signal" (logic signal) is established at position "A" and cancelled at position "C". This arrangement is well known in the art and will not be described in greater detail here.
The arm 8 in the illustrated embodiment of an apparatus according to the present invention is mounted on the beam 2 with the aid of mounting fittings 9 and an Allen bolt 10. The mounting fittings 9 and the bolt 10 permit orientation positioning of the arm 8 so that the free end of the arm 8 will be placed in a suitable manner ahead of the longitudinal channel 7 in the reed, as illustrated in FIG. 2. FIG. 2 also intimates with solid lines three optical axes 11, 12 and 13 as well as that angle which each respective optical axis makes with the longitudinal axis of the arm 8 seen from the side or the projection illustrated in FIG. 2. These angles are, moreover, shown in greater detail in FIG. 3.
The arm 8 is shown in greater detail in FIGS. 3-8, FIGS. 4, 5 and 6 showing respectively sections A--A, B--B and C--C in FIG. 1 on a larger scale. The above-mentioned optical axes 11, 12 and 13 are shown in the sections. In FIG. 3, it is more clearly apparent that the optical axis 11 makes an angle of 50°-60°, preferably 56°, with the longitudinal axis of the arm 8, while the optical axis 12 makes an angle with the longitudinal axis of the arm 8 of 60°-70°, preferably 65°, and the optical axis 13 makes an angle with the longitudinal axis of the arm 8 of 40°-50°, preferably 44°. The arm 8 displays, at its free end, a planar surface 14 which makes an angle of 40°-45°, preferably 42°, with the longitudinal axis of the arm 8. The free end of the arm 8 is terminated by a further planar surface 15 which makes an angle of 60°-70° , preferably 65°, with the longitudinal axis of the arm 8. The above-mentioned angles can, naturally, vary from design to design, depending upon the appearance and dimensions of the longitudinal channel 7 in the reed, which may vary from machine design to machine design.
In the free end of the arm 8, there is provided a recess 16 which discharges in the surface 14 and is intended for a light source in the form of a suitable LED. The recess 16 is oriented such that the optical axis, of the LED placed therein coincides with the optical axis 11 which is shown by ghosted lines. In the free end of the arm 8, there is further provided a recess 17 which discharges in the planar surface 14 and is intended for a light-sensitive element in the form of a suitable phototransistor TR1. The recess 17 is oriented such that the optical axis of the phototransistor TR1 placed therein coincides with the optical axis 12 which is shown by ghosted lines. In the free end of the arm 8, there is further provided a recess 18 which discharges in the planar surface 14 and is intended for yet a further light-sensitive element in the form of a phototransistor TR2 and which is aligned such that the optical axis of the phototransistor TR2 coincides with the intimated optical axis 13 which is shown by ghosted lines. As reference line, the longitudinal axis of the arm 8 is shown in the various Drawing FIGS. 4, 5, 6 and 8 in the form of a ghosted line 19. In FIGS. 4, 5 and 6, it is shown that the optical axes 11, 12 and 13 intersect one another at a point 20 which is also designated the focal point for the light source and the light-sensitive elements.
Through the focal point 20, there extends a normal 21 to the planar surface 14 and, in FIG. 4, it is shown that the optical axis 13 makes an angle with the normal 21 of 12°-16°, preferably 14°. In FIG. 5 it is shown that the optical axis 11 makes an angle of 5°-10°, preferably 7°, with the normal 21, and in FIG. 6 it is apparent that the optical axis 12 makes an angle of 20°-25°, preferably 22°, with the normal 21. The arm 8 is oriented such that the focal point 20 is located approx. 1 mm ahead of the distal edge in the channel 7.
FIG. 7 shows the arm 8 from the opposite side relative to FIG. 3, while FIG. 8 shows the arm 8 from the front. In the arm 8, there are further accommodated holes 22 and 23, recesses 24 and 25 and a milling 26 for mounting and placing of, for example, electronic components.
As is particularly apparent from FIG. 2, the light source will, with its optical axis 11, illuminate the rear edge or bottom in the longitudinal channel 7 in the reed. The light source or LED must be of the wide radiating type for relatively uniform illumination of the bottom or the rear edge in the channel 7. It is further apparent from FIG. 2 that the optical axis 12 of the light-sensitive element or phototransistor TR1 is directed towards the lower corner in the longitudinal channel 7 or the lower edge of the bottom in the longitudinal channel 7. The optical axis 13 of the light-sensitive element or phototransistor TR2 is directed towards the upper corner in the longitudinal channel 7 or the upper edge of the bottom in the longitudinal channel 7. The light-sensitive elements or phototransistors TR1 and TR2 should advantageously have narrow sensitivity lobes. The optical axis 11 of the light source or LED impinges as well centrally on the bottom of the longitudinal channel 7 or centrally on the rear edge in the longitudinal channel 7 between the upper corner and the lower corner. Hereby, the entire bottom or rear edge in the longitudinal channel 7 will be illuminated and there will be obtained a reflection from the entire rear edge or bottom in the longitudinal channel 7.
The electronic elements in the form of the LED and the phototransistors TR1 and TR2 are coupled into a suitable electronic circuit for driving the light source with a carrier wave signal of a frequency of a few kHz, while the phototransistors are coupled into a circuit of, for example, the type illustrated in FIG. 9 which is a per se known signal charging circuit. The phototransistor TR1 is coupled to the negative input of an operational amplifier OP via a potentiometer P1 and a capacitor C1, and the phototransistor TR2 is coupled to the negative input of the operational amplifier OP via a potentiometer P2 and a capacitor C2. The potentiometers P1 and P2 serve for suitable adjustment of the amplitude of the signal obtained on the output from the operational amplifier OP. The amplitude of the signal will reflect changes in the light reflection on the two phototransistors TR1 and TR2 because of the presence of a thread or a weft in the channel 7, whereafter the amplitude change in the signal can be evaluated with the aid of a suitable electronic circuit which is included in a central unit for the loom. If the signal from the operational amplifier OP does not satisfy the criteria set by the electronic circuitry, an error function will be triggered, and this can entail knock-off or arrest of the loom.
In that case where it is desirable to operate at higher frequencies than a few kHz, it may be appropriate to replace the phototransistors by photodiodes which are more rapid than the phototransistors. In certain cases, it may be appropriate to replace the two potentiometers by a single potentiometer which is coupled in between the phototransistors and whose slider is connected to earth.
The embodiment of the present invention illustrated in FIGS. 10-13 corresponds in principle to the above-described embodiment and differs substantially from the above-described embodiment in that the recesses 17' and 18' for the phototransistors TR1 and TR2 are located substantially straight above one another, and in that the optical axes 11', 12' and 13' make other angles with the longitudinal axis 19' of the arm 8' than in the above-described embodiment.
In this new embodiment, the optical axis 11' for the recess 16' makes an angle of 45°-55°, preferably 48°, with the longitudinal axis 19 of the arm 8', which is located in the surface of the arm 8' facing towards the reed, as is apparent in FIG. 12. The recess 16' is intended for an LED, as in the above-described embodiment. Seen in the projection shown in FIG. 11, the optical axes 11', 12' and 13' make an angle of 10°-15°, preferably 13°, with the longitudinal axis 19 of the arm 8'. The point of intersection between the axes 11', 12' and 13' forms the focal point 20'.
FIG. 10 shows, in addition to the parts illustrated in FIG. 2, also a temple 27 which does not constitute any part of the invention proper according to this disclosure.
The major advantage of the present invention is that the phototransistors TR1 and TR2 are located in substantially the same plane, whereby scanning of the channel 7 will be considerably more exact. Furthermore, the arm 8' can be given a somewhat more slender and above all more compact design and construction.
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An apparatus for the arrival monitoring of a weft in a jet loom with a reed pivotal between a first position and a second position. The reed has a longitudinal channel for the weft. An arm is mounted on the reed with the free end of the arm in the proximity of the longitudinal channel. The free end supports a light source and two light-sensitive elements. The light source is directed towards a central part of the channel for illuminating the rear portion of the channel. One light-sensitive element is directed towards the upper corner of the channel, while the other light-sensitive element is directed towards the lower corner of the channel.
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FIELD OF THE INVENTION
This invention relates to packing material for steam service and more particularly to a method and apparatus for minimizing steam leakage and extending packing life by providing a wire-reinforced packing material which results in minimum valve-stem wear, and a convenient orientation-independent installation.
BACKGROUND OF THE INVENTION
In the past there have been many attempts to provide packing materials for steam service. Because of the high pressure, high temperature superheated steam involved, ordinary packing materials cannot be utilized. Rather wire-reinforced asbestos-jacketed packings have been commonly utilized in steam valves. In automatic control steam valves, not only is steam integrity important due to 2000 psi and higher steam, but also valve stem erosion causes failure due to constant cycling, with the erosion being primarily due to wear produced by over use of reinforcing wire.
In general, prior steam service packings have been made on round braiders. Typically they use a resilient or pliable core material completely surrounded by a braided material in which the braid contains wire, usually Inconnel. Thus the packing is surrounded with reinforcing wire, which under pressure slices through the braid, contacts the valve stem and scores it because the Inconnel wire is harder than the commonly used steel or stainless steel valve stems. This causes leakage and subsequent catastrophic failure if the packing is not replaced frequently. Note the abraided particles from the valve stem also can cause packing failure, which with high pressure steam presents a very serious hazard, especially to those employed to repair a leak. As will be appreciated, when automatic steam control valves are used in electric power generation plants, oftentimes the turbines cannot be shut down, which necessitates repair in the presence of live steam presenting a hazardous leak stopping operation. It is thus necessary that the packing cause as little damage as possible to the valve stems while at the same time preventing steam leakage so that long packing life is assured.
Prior steam service packings include Crane style 187-I or Chesterton style 1500 which utilize a so-called "plastic" or flexible core of high purity asbestos, graphite flake, rubber, zinc and oil surrounded by wire-reinforced asbestos which is braided around the plastic core. The circumferential wire reinforcement of these packings and packing of similar construction present an overly abundant amount of wire to the valve stem, and with constant cycling of the valve stem requires repacking and valve reconstruction as early as three months due to valve stem wear.
Moreover, because these packings contain asbestos there is a problem when temperatures exceed 700° F. in which the water of hydration in the asbestos is driven away. This results in the production of ovine powder. When this occurs the entire packing looses water and shrinks. Also the packing hardens which prevents adjustment of the packing by tightening the gland bolts. Moreover, there are removal problems due to the virtual disintegration of the packing with exposure to the high temperature steam.
Thus, aside from wire abrasion problems, at temperatures above 600-700° F. in superheated steam the asbestos fibers begin to loose their water of hydration, forming ovine powder as has been noted in the EPRI valve system packing report by Stone & Webster Engineering Corporation, 1982. This results in shrinkage of the packing in the stuffing box, allowing leakage of steam, and requiring adjustment of the packing to stop the leakage. As noted in the report, the rubber and other binders in the packing harden, making adjustment difficult, if not impossible. As a result of the steam leakage, some of the asbestos fibers from the packing are carried into the air. Tests have found that some of these asbestos fibers carried into the air may be small enough to be respirable. These are the friable asbestos "fly", which has been named a carcinogen in 29 CFR 1910 and 1926 and for which specific standards have been set. As a result of these standards, and the hazards presented by handling asbestos packings, their use has been discouraged.
Regardless of the problems with asbestos, all these packings use an excessive amount of reinforcing wire, because all the yarn woven around the core is provided with wire. This results in excessive abrasion to the valve stems because all braiding in contact with the valve stem surface contains the reinforcing wire.
In an effort to solve all but the excessive wire problem, fiberglass reinforced with wire has been utilized, with the fiberglass provided in the core material to replace the asbestos and also as the woven material around the core for the same purpose.
The problem with fiberglass is that its relative long fibers break under changing pressures and temperatures and vibration, conditions which exist in the high temperature steam generating systems in which these packings are used. This again results in shrinkage. Moreover, the packing loses strength and suffers both the above removal problems and the utilization of an over amount of wire reinforcing because each overbraided yarn in these so called asbestos replacement packings contain reinforcing wire.
In order to solve the problem of packings using the pure fiberglass construction to replace asbestos, plastic cores with carbon fibers added to fiberglass, rubber, oil and zinc have been utilized for the core, and the over-braided structure contains some carbon fiber along with the wire and fiberglass.
Again the problem with such a packing is that it becomes extremely hard in service. Also shrinkage due to oil evaporation occurs and the oil also carbonizes which contributes to the hardening, a lack of adjustability and a shorter life span vis-a-vis the aforementioned asbestos braids based upon the experience of power generating plants. Here there are also removal problems and the problem of an overage of wire reinforcing material which causes abrasion on valve stems.
As another attempt to solve the problems with fiberglass, Chesterton style 1000 packing goes back to the use of asbestos, but uses a plaited or braided core of high purity asbestos instead of a plastic core. Again the core is provided with an outer braid of wire-reinforced asbestos. Here the plated core contains no oil or rubber which eliminates the hardening problems. However, an overage of wire is still in evidence. Moreover, there is shrinkage due to the drive off of the water hydration in the asbestos. The solution by Garlock style 1298 packing is the introduction of PBI (polybenzimidazole), in which PBI is substituted for asbestos and is braided about a carbon or graphite core. Additionally carbon fiber is utilized in the outer braid, along with wire and the PBI. The problems with this type of packing is that again too much wire is utilized. Shrinkage is also a problem which occurs with PBI above 700° F.
By way of further background, non-wire reinforced packings are used for low pressure applications in which a sturdier secondary yarn is braided on diagonal tracks to give packings strength, especially at their edges. Such diagonally-reinforced packings are described in U.S. Pat. Application Ser. No. 943,950, filed Dec. 18, 1986 and now U.S. Pat. No. 4,802,398 assigned to the assignee hereof. Whether single or double diagonals are reinforced, none of the packings described in this Patent Application are used for steam service. Nor are they wire-reinforced.
By way of additional background as to braiding techniques, it should be noted that the Parker Company produces a packing style in which carriers on the diagonal tracks carry a differently-colored yarn. This braid differs from conventional braid in that only every other carrier on a given track is provided with the differently-colored yarn. The result of this braiding technique is mostly decorative so as to provide a braid which has alternating light and dark areas.
Were one to provide the Parker braid with wire-reinforced yarn on the carriers utilized in a 3 track braider for the differently colored yarn, one might produce a reinforced packing. However, there would be a foot print on the valve stem which would permit steam passage through the non-reinforced braided portions. In other words, were the Parker braid provided with wire-reinforced yarn for the carriers involved in producing their braid, the resulting braid might not be of any use in steam service because non-reinforced channels or voids might be left running down the valve stem, thus permitting massive steam leakage.
SUMMARY OF THE INVENTION
In contradistinction to all of the above packings, the Subject System involves a reinforced non-asbestos packing in which the wire utilized is provided only on packing edges. This eliminates the use of wire between the inner edges, which reduces the amount of wire contacting the valve stem by as much as 80%. It has been found that edge reinforcing is all that is necessary for preventing steam leakage. By using a interlocking braider and a double diagonal wire-reinforced braid all edges are reinforced so that there can be no problem with backward or upside down installation of the packing. A single diagonal can be reinforced with wire, as long as there are markings on the packing so that it can be installed with the reinforced edge properly presented to the steam at the stem surface.
In a preferred embodiment, an alternating double diagonal braid is used to reduce the amount of wire which contacts the valve stem to only 18% of the braid touching the valve stem, thus minimizing abrasion. To effectuate this braid, alternating carriers on both diagonal tracks carry the wire-reinforced secondary yarn. As opposed to the Parker braid, here there is an offset in the wire-reinforced braid which results in complete circumferential sealing. This is produced by selecting which of the alternating carriers on each diagonal track carry the wire-reinforced yarn, such that the offset occurs. Should there be insufficient offset to provide a completely circumferential reinforced barrier to the steam due to an incomplete overlap of offset wire-reinforced yarns, this deficiency can be overcome using the keystone-resisting techniques of U.S. Pat. No. 4,550,639 issued to George B. Champlin on Nov. 5, 1985, incorporated herein by reference, which involves heavier or more warp yarns at the outer edges of the packing. The insufficient overlap is in part due to keystoning of the square packing when the packing is wrapped around a shaft. The above keystone-resisting configuration in effect cancels out the keystoning effect.
Assuming adequate overlap of the offset wire-reinforced yarns on the inside leading and trailing edges of the packing, the result is that wire reinforcing when viewed in the axial direction of the valve stem provides complete circumferential blockage, with the foot print being such that there are no unreinforced channels along the length of the valve stem which would permit steam leakage. Thus viewed end-on, for each packing ring, there is a circumferential barrier of reinforced packing presented to the steam which provides a continuous reinforced seal completely all around the valve stem.
The utilization of the alternating braid cuts the amount of metal contacting a valve stem to approximately 9% of that associated with other steam service packings. Were all carriers on each of the diagonals provided with wire reinforcement, there would still be a substantial reduction in the amount of wire reinforcement over the complete circumferential braiding associated with prior steam service packings. However, by utilizing the alternating braid of the Subject Invention an absolute minimum amount of wire reinforcing provides for complete reliable, long-life packing for steam valves and other steam service applications.
In order to eliminate the problems of asbestos, in a preferred embodiment all core and braid yarns are made of graphite or carbon. This eliminates, shrinkage, hardening or disintegration associated with asbestos packing previously used. The use of carbon or graphite also eliminates the problems of using fiberglass in high temperature, high pressure service.
As mentioned, it has been a practice in low pressure, low temperature applications to use packings reinforced with strong yarns, primarily aramid, on the corners to prevent extrusion. These packings have no metal reinforcement and are not suitable for high pressure steam service. It will be noted that these packings are made with the secondary yarn on all carriers of each diagonal track of the braiding machine. While an advantage for steam service is obtained if one were to provide reinforcing wire along with secondary yarn on all diagonal track carriers, this does not achieve a minimum amount of wire reinforcing. However, as compared to prior packings completely surrounded with wire-reinforced braids, wire reinforcing at interior corners reduces the wire contacting a valve stem by as much as 78%. A double diagonally-reinforced packing does eliminate the problem of backwards mounting of packing in a stuffing box adjacent a valve stem because there is no preferential direction. It will of course be appreciated that since the aforementioned prior double diagonal braid contained no metal reinforcement and has been made from materials which have thermal limitations of 600° F., such braid was not heretofore considered for utilization in high temperature steam applications.
In summary, edge-reinforced packing is provided for steam service, with wire-reinforced secondary yarns at one or more pairs of diagonally opposed corners of the packing to provide the edge-reinforcing which reduces valve stem abrasion while providing sufficient resistance to high pressure, high temperature steam leakage. Wire-reinforcing only the edges of the packing minimizes the amount of reinforcing wire necessary to counteract high pressure steam and thus minimizes valve stem wear. An offset, alternating braid embodiment further reduces wire usage at the packing edges, while at the same time providing complete circumferential reinforced sealing around the valve stem. In this embodiment selected alternating yarn carriers along a diagonal track are provided with secondary yarn reinforced with wire. The relationship of the carriers provided with reinforcing wire is such as to provide an offset, alternating braid in which the foot print along the surface of a valve stem is such as to provide a continuous reinforced barrier to steam pressure. In cases where the braiding results in voids in the steam barrier produced by the reinforced braid, keystone-resisting technology corrects this problem. In one embodiment, the packing is a non-asbestos packing which eliminates both hardening and packing disintegration. In a further embodiment with reinforcing wire on both diagonals, the diagonal symmetry alleviates problems associated with installing the packing backwards.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the Subject Invention will be better understood in connection with the detailed description taken in conjunction with the drawings of which:
FIG. 1A is a sectional and diagrammatic illustration of an automatic control valve for use in steam service, illustrating the utilization of the subject packing to prevent steam leakage around the valve stem;
FIG. 1B is a diagrammatic and sectional illustration of a manual steam valve utilizing the Subject packing;
FIG. 2A is a diagrammatic illustration of a number of rings of packing having a plastic core made on a typical round braider, in which the inside surfaces of the rings are illustrated as carrying an overage of wire which contacts the surface of a valve stem shown here in dotted outline;
FIG. 2B is a diagrammatic illustration of edge reinforcement for a packing made in accordance with the Subject Invention on a four track braider, illustrating the inside surfaces of a pair of rings and a reduction of exposed wire;
FIG. 2C is a diagrammatic illustration of the four track braided packing of FIG. 2B in which an offset alternating braid configuration is shown in which alternating edge yarns carry reinforcing wire;
FIG. 2D is a diagrammatic illustration of an edge-reinforced packing made in accordance with the Subject Invention on a three track braider;
FIG. 2E is a diagrammatic illustration of an edge-reinforced packing made in accordance with the Subject Invention that can be installed with either reinforced inside edge toward the bottom of the stuffing box, in which alternating edge yarns carry reinforcing wire which presents a minimum of wire to the valve stem;
FIG. 3 is a diagrammatic illustration of a diagonally-reinforced packing which is directionally dependent in installation in which wire is utilized along with the secondary yarn to provide diagonal edge reinforcement and which presents a minimum of wire to the valve stem;
FIG. 4 is a diagrammatic illustration of the carriers on a single diagonal which are provided with yarn having embedded reinforcing wire for a three track interlocking braider;
FIG. 5 is a diagrammatic illustration of a double-diagonal reinforced wire packing in which all carriers on each diagonal track are provided with yarn having embedded reinforcing wire for a three track interlocking braider;
FIG. 6 is a diagrammatic illustration of the alternating braid embodiment in which alternating carriers are provided with yarn having embedded reinforcing wire for a three track interlocking braider;
FIG. 7A is a diagrammatic illustration of the inside surface of a prior art packing illustrating the utilization of reinforcing wires embedded in all exterior braided yarn;
FIG. 7B is a diagrammatic illustration of the Subject Invention in which only corner yarns are provided with wire reinforcement;
FIG. 7C is a diagrammatic illustration of an offset braid on a three track machine, illustrating the overlapping of the bottom wire-reinforced yarn with respect to the opposed top wire-reinforced yarns;
FIG. 7D is a diagrammatic illustration of the packing of FIG. 7C illustrating longitudinal gaps which can be caused by keystoning when the braid of FIG. 7C is wrapped around a valve stem or shaft;
FIG. 8A is a diagrammatic illustration of the effect of keystoning on the footprint of the wire-reinforced yarns on the surface of the valve stem, illustrating longitudinally running channels down the valve stem;
FIG. 8B is an end view of the footprint pattern associated with the keystoned packing, illustrating the void channels in cross-section;
FIG. 8C is a diagrammatic illustration of the packing of FIG. 8A in which keystoning is eliminated by a keystone-resisting original configuration, illustrating the overlapping of the alternating braids, thereby to provide a complete barrier to steam pressure;
FIG. 8D is a diagrammatic illustration of complete circumferential protection provided by an alternating braid in which overlapping is achieved;
FIG. 8E is a diagrammatic illustration of a keystone-resisting packing for use in steam service such as illustrated in FIG. 8C;
FIG. 9A is a diagrammatic illustration of edge reinforced packing produced on four track machine;
FIG. 9B is diagrammatic illustration of edge reinforced packing utilizing an alternating offset braid in which the bottom wire-reinforced yarn overlaps the adjacent top reinforced yarns.
DETAILED DESCRIPTION
Referring to FIG. lA, the Subject packing 10 may be utilized with a poppet control valve generally indicated by reference character 12 which includes a valve body 14 having a valve seat 16. Here a conical seal 20 is located at one end of a valve stem 22 which at its opposite end has a control rack 24 associated with a pinion 26 driven by worm gear 28. The worm gear is powered by motor 30 under control of a control unit 32 having as an input thereto the output of sensor 34 which, inter alia, senses either steam pressure or temperature.
Poppet valve 12 is controlled on a continuous basis which causes the valve stem and control rack to move up and down as indicated by double ended arrow 36 in response to the rotation of pinion 26 as illustrated by double ended arrow 38.
Valve stem 22 projects through a yoke nut 40 threaded into a yoke 42 and through a two part gland 44 and 46 in which the gland is tightened down over packing 10 via gland nuts 48 on studs 50, with the gland being secured to the stuffing box 52 that includes a flanged portion 54 through which studs 50 project. The packing is placed between the bottom surface 56 of gland 46 and a guide bushing 58 through which the valve stem projects and which is held in place by a set screw 60.
What will be appreciated is that this type of control valve and in fact any type of automatic control valve used in steam service reciprocates constantly under control of a sensed parameter. The result, as mentioned hereinbefore, is that with prior art packings the valve stem becomes scored, resulting in steam leakage and ultimate failure.
Because of the extensive amount of reinforcing wire utilized in prior art packings, the packing and indeed the entire assembly may need replacing as often as every year. The reinforcing wires are necessary in the presence of high pressure, high temperature steam, in which pressures exceed 2,000 lbs. per square inch and in which the temperatures exceed 700° F. While sealing against such high quality steam is essential in automatic control valves, the same situation exists with respect to manual control valves such as that pictured in FIG. lB, in which like reference characters refer to like elements. Here the upper portion of valve stem 22 is threaded as can be seen at 62, with the threaded portion extending up through a yoke nut 40 to a conventional wheel 64. Here the stuffing box is integrally formed in a valve bonnet 68. Again, in steam service such a valve requires metal reinforcing wires embedded within the packing material, with the reinforcing wire typically being Inconnel wire.
Referring now to FIG. 2A, typically a prior art packing ring, here illustrated at 70, is produced on a two track braider. The packing includes a central core 72 of resilient or plastic material completely surrounded by wire-reinforced braid consisting of yarns 72, each of which have reinforcing wire 74 embedded therein.
The resulting braided structure is as illustrated, in which the inside surface of the packing ring is a braided structure in which wires are exposed across the entire inside surface of the packing. The exposed wire is illustrated by reference character 76 to present itself to the surface of a valve stem here diagrammatically illustrated at 82, in which the entire inner surface 80 of packing has wire protruding therefrom. What is pictured in FIG. 2A is the situation in which the packing material is placed under compression by the gland of the valve such that the Inconnel wire slices through the yarn in which it is embedded and is therefore in contact with the surface of the valve stem.
Regardless of the way in which the prior art packings are made, it will be appreciated that whether the packing is asbestos, or graphite, has a resilient core, or has a woven core, the result is the same. This result is that there is an overage of wire presented at the inside surface of the packing which serves to score the valve stem. The aforementioned attempts at preventing hardening and preventing disintegration of the packing while useful in extending packing life, do not address the issue of the large amount of bare wire exposed to the valve stem. Thus, regardless of whether the core of the packing is made of a pliable material or whether the packing is indeed made of asbestos or fiberglass, the result is the same in that regardless of the amount of times that the packing is changed, the scoring of the valve stem continues. In the past further leakage due to the scoring of the valve stem is prevented through the tightening of the packing around the valve stem. This however merely intensifies the scoring of the valve stem and while temporarily solving a leakage problem, ultimately results in the necessity of replacing the valve stem as well as the packing.
In order to reduce the amount of wire necessary for providing a secure barrier against the high pressure, high temperature steam, while at the same time minimizing the extent of the wire used, and referring now to FIG. 2B a packing 90 made on a four track interlocking braider shows reinforcing wire 92 embedded only in yarns at the corners 94 and 96 of the packing. This is accomplished as diagrammatically illustrated by providing the bobbins on carriers running along the diagonal tracks 98 and 100 with yarns with embedded Inconnel wire. The resulting pattern illustrates that there is a central region 102 on the inside surface 104 of packing 90 which is completely devoid of wire. Because the reinforcing wire exists only at the edges of the packing, close to 80% of the wire previously thought necessary is removed. It has been demonstrated that adequate resistance to high temperature, high pressure steam is afforded by this reinforcing method.
In one embodiment the packing is made of non-asbestos materials such as pure graphite filament and wire reinforced carbon fiber, with the primary yarns on a double diamond track being of pure graphite filament and with the secondary yarns used on the diagonal tracks being of carbon fiber, which yarn is available with embedded Inconnel wire. It will be noted that in FIGS. 2B and 2C the double diamond primary braid tracks are not shown for convenience.
Referring now to FIG. 2C, the amount of wire that is used can be reduced in half over that of FIG. 2B packing through an offset alternating braid so as to produce the packing illustrated at 110. Here sets of offset wires 112 and 114 create an effective reinforced barrier completely around the valve stem while at the same time using only half the wire. What this means is that with alternating yarns which are offset and overlapped in the longitudinal direction carrying the reinforcing wire, the wire content can be cut by as much as 80% over that associated with prior steam service packings. The method of producing such a braid will be discussed hereinafter. However, as illustrated by open track 116 and closed track 118, assuming that every other bobbin on each track is provided with reinforced yarn, the resulting pattern will be the offset overlapping structure pictured.
The braid shown in FIG. 2C is that produced by a four track interlocking braider, whereas the corresponding three track interlocking braid is shown by packing 120 in FIG. 2D and packing 130 in FIG. 2E.
Referring to FIG. 2D, those yarns carrying the reinforcing wire are illustrated at 122 to be at opposed corners of the packing. What this means is that each bobbin on each carrier running on each diagonal track 124 and 126 is provided with a secondary yarn having embedded reinforcing wire. In this diagram the single diamond track is illustrated at 128.
Referring to FIG. 2E, again the amount of wire utilized can be reduced if the exposed wire at the edges is in an offset overlapping configuration as illustrated by wires 132 and wires 134. Here the overlapping and alternation is formed in the same manner as described in connection with FIG. 2C. As before, and as illustrated by tracks 136 and 138, the alternating braid is produced by virtue of having alternating bobbins carrying the wire-reinforced yarn. Again the single diamond track is illustrated by track 140.
Referring now to FIG. 3, a diagonally reinforced packing 140 provides opposed corners or edges 142 and 144 with a wire-reinforced yarn, in which the packing is made similar to that associated with the aforementioned Patent Application, with the exception that the bobbins on diagonal track 146 carry wire-reinforced yarn as a secondary yarn, as opposed to the non-wire-reinforced secondary yarn described in the Patent Application. It is important however with respect to this embodiment, especially with respect to steam service, that the orientation of the braid be clearly marked. If the packing is put in backwards there will be immediate steam leakage because the reinforced corner adjacent surface 148 of valve stem 150 will be the trailing edge and merely flip up in the presence of steam pressure impinging on the packing from the direction indicated by arrow 152. However with appropriate marking on the packing, one can ascertain that edge 142 is adjacent surface 148, i.e. that the wire-reinforced edge 142 is presented to the steam as the leading edge of the packing.
Referring to FIG. 4, in this diagram the diagonally reinforced braid of FIG. 3 is achieved through the utilization of bobbins 152 carrying the wire reinforced secondary yarn, in one embodiment a yarn made of carbon fiber, whereas carriers 154 on an opposed diagonal track carry only non-reinforced yarn.
Referring to FIG. 5, for a three track or four track interlocking braider, the packing shown in FIGS. 2B and 2D can be achieved by providing bobbins 160 on all diagonal tracks with wire-reinforced yarn.
Referring now to FIG. 6, the alternating braid providing the offset wire configurations of FIGS. 2C and 2E can be produced by providing alternate bobbins on a given diagonal with the wire-reinforced yarn. Here one diagonal track is illustrated by reference character 170, whereas the other diagonal track is indicated by reference character 172. The bobbins which carry the wire-reinforced yarn are represented by the blackened "A" circles on track 170, whereas those bobbins which Carry only the secondary yarn are illustrated by the open "A" circles on this track. Likewise for the opposed diagonal track 172, bobbins "B" which carry the wire-reinforced yarn are the blackened circles, whereas those carrying no reinforcing yarn are indicated by the open circles. The direction of movement of the respective bobbins on the track is indicated by arrows 174 and 176. It will be appreciated that there is a certain phasing of the carriers which produces the desired offset result, which in one embodiment involves the bobbins of track 170, the "A" bobbins, leading the "B" bobbins of track 172.
Those experienced in the art of braiding will be able to load the secondary yarn on alternating carriers of track "B", such that "B" carriers lead or follow the carriers of track "A" so that of the resulting braid achieves the desired offset on the side of the packing intended to be placed in contact with the valve stem, as opposed to generating the undesired pattern on this surface as illustrated in FIG. 7D. The above-mentioned overlap will be graphically illustrated in connection with FIGS. 7B and 7C.
Referring however now to FIG. 7A, in the prior art it will be appreciated that the interior face 180 of the prior art braid includes woven yarns 182, with the shading indicating that each of the yarns carries a reinforcing wire. This is in contradistinction to the braid shown in FIG. 7B in which the central yarns 184 are devoid of reinforcing wire. This, at least diagrammatically illustrates a reduction of the wire which contacts the valve stem surface. It will be appreciated that the braid shown in FIGS. 7A, 7B, 7C and 7D are those available from a 3 track interlocking braider.
Referring now to FIG. 7C, the alternatinq braid pattern is shown in which the shaded yarns 186 are those carrying the reinforcing wire, whereas the remainder of the yarns 188 do not carry reinforcing wire.
More importantly with respect to this Figure, it will be appreciated that from one edge to the other of the inner surface of the packing, there is a channel illustrated by dotted lines 190 which do not present a reinforced edge to incoming steam, at least as far as the leading edge 192 of the packing is concerned. However, due to the overlap of the corresponding offset wire-reinforced yarn 188, there is essentially a reinforced packing portion which compensates for the initial void or gap.
It is however possible that longitudinal channels 190' can be left in a packing which does not have the appropriate offset of reinforced yarns 186 with respect to yarns 188. In this case there would be longitudinal channels down the valve stem which would not be reinforced and therefore subject to obstruction by the oncoming high power steam. This lack of overlap can be due to keystoning, when a square cross-section packing is wrapped around a cylindrical shaft. As will be seen in FIGS. 8C, 8D and 8E this problem of non-overlap of the alternating yarns can be solved through the utilization of the aforementioned keystone-resisting configuration, which in effect moves one set of wire-reinforced yarns with respect to the other, when the braiding is in place around the valve stem, so that the required overlap occurs to provide a complete circumferential reinforced barrier to the steam.
More specifically, and referring now to FIG. 8A, it can be seen that a valve stem 200 is provided with a conventional woven packing 202 which, when wrapped around the valve stem, assumes a keystone-type trapezoidal shape illustrated by keystoning 204. This in turn provides a footprint 206 of protection which leaves channels 208 devoid of the required reinforced packing material. This results in the formation of longitudinal channels 208 of FIG. 8B, down the length of the valve stem 200. The result of the introduction of such channels is that steam leakage is virtually assured as well as eventual destruction of the packing itself. As illustrated, and as described in the aforementioned patent, axial warps or warp yarns 210 conventionally used in all packings have the same density or same number, such that there is no protection against a square braid keystoning when wrapped around a cylindrical valve stem.
A method of preventing keystoning is illustrated in FIG. 8C. This method is described in the aforementioned patent and includes providing a packing ring 220 with a greater density of warp yarns 210 at the outer corners 212 of packing 220, whereas less dense or fewer numbers of warp yarns are used at positions 214 at the inner corners 216 of the packing. The resultant foot print, rather than being one involving no overlap, now has the required overlap as illustrated by the relative position of leading edge reinforced yarns 220 as opposed to the corresponding trailing edge yarns 222. Here the channel 224 while existing at the leading edge, is blocked by the overlapping yarn 222 at the trailing edge.
As illustrated in FIG. 8D, a complete circumferential protection is provided by virtue of the projection of the positions of the reinforced yarns onto a single plane as illustrated at 230.
The keystone-resisting packing described in the aforementioned patent is illustrated in FIG. 8E, in which the original keystone-resisting shape of the packing is illustrated by the solid line 232 which provides the packing 220 with a trapezoidal cross section equal to and opposite that which would be expected when a straight walled packing is wrapped around a cylindrical surface. By virtue of providing the keystone-resisting configuration, it is possible to control the overlap in the alternating braid configuration of the Subject Invention, so that an appropriate offset and coverage can be obtained.
Referring to FIG. 9A, packing 138 with the subject wire-reinforced edge is shown made on a four track interlocking braider in which all edge yarns 240 are wire-reinforced, whereas all intermediate yarns 242 carry only the secondary yarns without wire reinforcement. Referring to FIG. 9B a packing 139 is shown with the subject offset braid, in which yarns 244 are wire-reinforced at the leading edge 246 of the packing, whereas an overlapping yarn 248 is wire-reinforced on the trailing edge of the packing. It will be noted as indicated by dotted lines 250 that there are no longitudinal voids in the packing such as indicated in FIG. 7D by dotted lines 190'.
While keystoning is sometimes a problem with respect to a non-overlapped coverage of the offset yarns, in the four track braider such voids do not generally exist. Thus while keystone-resisting technology may be utilized in producing the four track packings illustrated in FIGS. 9A and 9B, such keystone-resisting technology may not be necessary to provide for the required overlap.
Note the offset alternating braid is applicable to two track plait braiders which can produce the alternating weave, with four, eight or twelve carriers.
Note also that while the subject packing has been described for use in steam service, it may be used in other hostile environments such as for valves which must handle chemical under high pressure; or for handling hazardous materials where packing integrity is important.
Having above indicated a preferred embodiment of the present invention, it will occur to those skilled in the art that modifications and alternatives can be practiced within the spirit of the invention. It is accordingly intended to define the scope of the invention only as indicated in the following claims:
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Edge-reinforced packing is provided for steam service, with wire-reinforced secondary yarns on carriers driven along one or more diagonal tracks of a braiding machine to provide edge-reinforcing which reduces valve stem abrasion while providing sufficient resistance to high pressure, high temperature steam leakage. Wire-reinforcing only the edges of the packing minimizes the amount of reinforcing wire necessary to counteract high pressure steam and thus minimizes valve stem wear. An offset, alternating braid embodiment further reduces wire usage at the packing edges, while at the same time providing complete circumferential reinforced sealing around the valve stem. In cases where the offset braiding results in voids in the steam barrier produced by the reinforced braid, keystone-resisting technology corrects this problem. In one embodiment, the packing is a non-asbestos packing which eliminates both hardening and packing disintegration normally associated with so called "plastic-core" packings. In a further embodiment with reinforcing wire on both diagonals, the diagonal symmetry alleviates problems associated with installing the packing upside down in the stuffing box.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 198 55 571.7 filed Dec. 2, 1998, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a feeding device for advancing fiber material to a textile fiber processing machine, such as a carding machine or a fiber cleaner. The fiber feeding device includes a slowly rotating feed roll cooperating with a feed tray assembly formed of individual feed tray segments. Further, a rapidly rotating opening roll is provided which is arranged immediately downstream of the feed tray assembly as viewed in the direction of fiber advance. One end of each feed tray segment is mounted on a fixed supporting element.
German Offenlegungsschrift (application published without examination) No. 34 13 595 discloses a feeder which is disposed upstream of a carding machine. The apparatus has a feed chute in the upper part of which an opening roll is provided and thereabove a feed roll is positioned to which fiber tufts are advanced via a feed tray assembly composed of closely side-by-side arranged individual feed tray segments. Each feed tray segment is pivotal about an axis oriented parallel to the feed roll axis. The feed tray segments are caused by the fiber tufts to undergo excursions which represent the mass of the fiber tufts contacting the respective feed tray segment. The feed tray assembly is positioned at the outlet of a reserve chute which is situated above the feed chute. The shaft to which the feed tray segments are secured projects beyond the two outermost feed tray segments and is situated adjacent the impervious lateral walls of the reserve chute. It is a disadvantage of such an arrangement that the shaft which extends over the entire width of the machine sags and therefore it cannot be used for roller card units having a substantial width of, for example, 3 m or more. Further, deformations may adversely affect an easy rotatability of the feed tray segments. Also, the distance between the feed tray segments, on the one hand, and the feed roll, on the other hand, disadvantageously changes and further, the pressing forces are not uniform between the feed tray segments, on the one hand, and the feed roll, on the other hand. Also, the clearance between adjoining feed tray segments may change or be distorted which may lead to operational disturbances. It is yet another drawback of the conventional arrangements that an adaptation of the feeding device to various types of fiber material, particularly various fiber lengths, is not feasible.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved feeding device of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, is structurally simple and operationally reliable and makes possible a precise clamping of the fiber material between the feed tray segments and the feed roll.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the feeding device for advancing fiber material includes a driven feed roll; a support member immovably held during operation and extending spaced from and generally parallel to the feed roll; and a feed tray assembly composed of a plurality of side-by-side positioned feed tray segments. Each feed tray segment is of a resilient material and has a first portion (end portion) immovably affixed to the support member and a movable, second portion having a surface oriented toward the feed roll and cooperating therewith for advancing the fiber material passing through a nip defined between the feed roll and each feed tray segment. The second portion of each feed tray segment is displaceable toward and away from the feed roll.
By affixing, according to the invention, one end of the feed tray segments to a common, stable and immovable supporting element, a linear orientation of the feed tray segments is ensured in a simple manner, and between the feed tray segments and the feed roll in all regions the same pressing forces related to the unit length of the feed roll is maintained. At the same time undesired deformations between adjoining feed tray segments is avoided, whereby the operational reliability and uniformity of the advanced fiber material are improved. It is a particular advantage of the invention that stationary, immovable machine components, including, for example, the machine frame, the machine stand, walls and connecting elements may be used to support the feed tray segments. The supporting element which is, for, example, affixed to the machine frame is compact and rigid. Thus, by firmly affixing the feed tray segments at an end thereof which is immovable, the feed tray segments are integrated into the machine structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a card feeder incorporating the invention.
FIG. 2 is a schematic side elevational view of a fiber cleaner incorporating the invention.
FIG. 3 is a schematic side elevational view of a preferred embodiment of the invention installed in the reserve chute of a roller card feeder.
FIG. 4 is a side elevational view of a feed tray segment according to the invention, associated with an inductive path sensor.
FIG. 5 is a side elevational view of a feed tray segment and its attachment to a carrier.
FIG. 6 is a schematic side elevational view showing a spring support for a feed tray segment according to the invention.
FIG. 7 is a schematic side elevational view, similar to FIG. 6, showing a pressing spring in alignment with the location of the maximum pressure forces between a feed tray segment and a feed roll.
FIG. 7a is a graph illustrating the pressure/displacement curve.
FIG. 8 is a schematic side elevational view showing the accommodation of a pressing spring in the feed tray segment and a spring support.
FIG. 9 is a schematic side elevational view showing a feed tray segment and an elastomer spring rod disposed between the feed tray segment and a counter support.
FIG. 10 is a schematic side elevational view showing a feed tray segment and a metal/rubber buffer disposed between the feed tray segment and a counter support.
FIG. 11 is a view similar to FIG. 9, showing a hollow elastomer spring rod.
FIG. 12 is a schematic perspective view showing part of a feed tray assembly and a single rubber bar biasing the feed tray segments.
FIG. 13 is a schematic perspective view of a fragment of a single-piece feed tray assembly.
FIG. 14a is a schematic side elevational view of a feed tray assembly according to the invention.
FIG. 14b is a schematic front elevational view of the construction shown in FIG. 14a.
FIG. 15 is a fragmentary side elevational view of a feed tray segment plated with high grade steel.
FIG. 16 is a side elevational view of a feed tray segment including a sheet metal covering.
FIG. 17 is a fragmentary side elevational view of a feed tray segment showing a spring biased support for a rubber pressing spring.
FIG. 18 is a fragmentary schematic side elevational view of a feed tray segment and an abutment limiting the excursion of the feed tray segment.
FIG. 19 is a block diagram of an electronic control and regulating device to which the inductive path sensors associated with the respective feed tray segments as shown in FIG. 4 as well as an rpm-regulated drive motor for the feed roll are connected.
FIG. 20a is a side elevational view of a feed tray assembly partially in section, according to a further embodiment of the invention.
FIG. 20b is a front elevational view of the construction shown in FIG. 20a.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, upstream of a non-illustrated carding machine a card feeder CF is disposed which may be, for example, a DIRECTFEED model manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The card feeder CF is provided with a vertically oriented reserve chute 2 charged from the top with a mixture I composed of air and finely opened fiber material. Such a feed may be effected by a condenser via a supply and distributor duct 3. In the upper region of the reserve chute 2 air outlet openings 4 are provided through which the transporting air II passes into a suction device 5 after being separated from the fiber tufts III. The lower end of the reserve chute 2 is closed off by a feed roll 6 which cooperates with a feed tray assembly 7 composed of a plurality of serially arranged feed tray segments 7a, as shown, for example, in FIG. 14b. The slowly rotating feed roll 6 draws the fiber material III from the reserve chute 2 and advances it to a rapidly rotating opening roll 8 which may be provided with pins or may have a sawtooth clothing. The feed roll rotates clockwise as indicated by the arrow 6a whereas the opening roll 8 rotates counterclockwise so that oppositely oriented rotations of the two rolls are obtained.
One part of the circumference of the opening roll 8 projects into a feed chute 9 which adjoins the reserve chute 2. The opening roll 8, as it rotates in the direction of the arrow 8a, advances the fiber material IV to the feed chute 9 which, at its lower end, has a rotary pull-off roll 10. The pull-off roll 10, in turn, advances the fiber material (fiber lap) to the non-illustrated carding machine.
The walls of the feed chute 9 are provided in the lower part thereof with air outlet openings 11', 11". The upper portion of the feed chute 9 is in communication with a space 12 with which the pressure outlet of a fan 13 communicates. By means of the rotating feed roll 6 and the opening roll 8 a predetermined quantity of fiber material III is continuously supplied to the feed chute 9 and an equal quantity of fiber material (fiber lap) is withdrawn by the withdrawing roll 10. The latter cooperates with a feed tray assembly 14 composed of a plurality of serially arranged feed tray segments. The feeding (fiber lap withdrawing) arrangement 10, 14 introduces the fiber lap to the non-illustrated carding machine. To uniformly densify and maintain constant the fiber quantities, in the feed chute 9 the fiber material is exposed to an air stream from the space 12, driven by the fan 13. The air is drawn into the fan 13 and driven through the fiber mass dwelling in the feed chute 9 and, thereafter, the air exits through the air outlet openings 11', 11" at the lower end portion of the feed chute 9.
The opening roll 8 is surrounded by a wall of a housing 15, while the feed roll 6 is surrounded by a wall of a housing 16; the walls are adapted to the circular configuration of the rolls 6 and 8. As viewed in the rotary direction 8a of the opening roll 8, the housing 15 is interrupted by a separating opening for the fiber material III. The separating opening is adjoined by the wall face which reaches to the feed roll 6. The feed tray assembly 7 is arranged at the lower end of the wall face situated opposite the feed roll 6. The edge of the feed tray assembly 7 is oriented in the direction of rotation 8a of the opening roll 8. The plane which contains the rotary axis of the feed roll 6 and the opening roll 8 is arranged at an oblique angle to the vertical plane containing the rotary axis of the opening roll 8 and is inclined in the rotary direction of the opening roll 8. The wall face 2a of the reserve chute 2 forms a stationary support element 17 of the machine frame 18. The feed tray segments 7a of the feed tray assembly (feed tray bodies)7 2 are in the region of one of their ends 7 1 mounted on the stationary support element 17 whereas their respective other ends (feed tray bodies) 7 2 are freely movable. The ends 7 1 are immovably secured to the support element 17 of the machine frame 18. The feed tray assembly 7 is made of an elastic material, whereby the free ends 7 2 of the individual feed tray elements 7a are freely movable in the direction of the arrows A and B.
FIG. 2 illustrates a fiber cleaning device which is accommodated in a closed housing 26 and which may be a CVT cleaner manufactured by Trutzschler GmbH & Co. KG. The fiber material to be cleaned, particularly cotton, is supplied to the cleaner in fiber tuft form. This is effected, for example, by a non-illustrated feed chute, by a feed belt or the like. The fiber lap is advanced to a rapidly rotating pin roll 23 (having pins 23a and a diameter, for example, of 250 mm) by a withdrawing roll (feed roll) 21 and a feed tray assembly 22 cooperating therewith to effect clamping of the fiber lap. The pin roll 23 is rotatably supported in the housing and rotates in the direction of the arrow 23b. The pin roll 23 is followed by clothed rolls 24 and 25 rotating in respective directions 24b and 25b. The clothed roll 24 is provided with a sawtooth clothing and has a diameter of, for example, 250 mm. The pin roll 23 has a circumferential speed of, for example, 15 m/sec while the roll 24 has a circumferential of, for example 20 m/sec. The circumferential speed of the roll 25 is greater than that of the roll 24; the diameter of the roll 24 is, for example, 250 mm. The pin roll 23 is closely surrounded by the housing 26 and cooperates with a separating opening 29 for the exit of fiber impurities. The size of the opening 29 may be adapted to the degree of dirt of the cotton. The separating opening 29 is bordered by a severing edge, for example, a mote knife.
The feeding device is formed of the slowly rotating feed roll 21 which rotates in the direction of the arrow 21a and the feed tray assembly 22 which is disposed above the feed roll 21. The feed tray assembly 22 is, at one end 22a, supported on an immovable support element 27 of the stationary housing 26. A spring 28 engages the outer upper face 22' of the feed tray assembly 22 for resiliently urging the feed tray assembly 22 toward the feed roll 21 which is rotatably but radially immovably supported. The feed tray 22 is composed of a plurality of feed tray elements whose free ends are movable in the direction of the arrows A and B. The feed tray assembly 22 is structured similarly to the earlier described feed tray assembly 7.
The above-described cleaner operates as follows:
The fiber lap composed of fiber tufts is advanced by the feed roll 21 in cooperation with the feed tray assembly 22 under the clamping effect of the pin roll 23 which combs the fiber material III and entrains fiber clumps on its pins. As the circumferential surface portions of the roll 23 pass by the separating opening 29 and the mote knife 30, short fibers and coarse impurities are thrown out by centrifugal force from the fiber material through the separating opening 29 as a function of the circumferential speed and curvature of the roll 23 as well as a function of the size of the separating opening 29 adapted to the first separating stage. The thus pre-cleaned fiber material is taken over by the clothing points 24a of the clothed roll 24 from the first roll (pin roll) 23, as a result of which the fiber material is further opened. Thereafter, the fiber material is taken over by the clothing points 25a of the roll 25 which is situated downstream of the roll 24 as viewed in the working direction C and as a result, the fiber material is still further opened and eventually is transported to a non-illustrated further processing machine by a pneumatic removal apparatus 31.
The apparatus illustrated in FIG. 3a is a feeder for a roller card unit and corresponds essentially to the card feeder of FIG. 1. While the working width in a card feeder is approximately 1-1.5 m, this dimension is 3 m or more in a roller card feeder. The feeder includes a hollow, cross-sectionally rectangular carrier beam 35 which may be made of structural steel. The carrier beam 35 is stable and resists bending and has a length of about 5 m. Between the carrier beam 35 and the feed roll 6 a feed tray assembly 7 is provided which is composed, as described before, of a plurality of feed tray segments 7a secured to a support element 17. The feed tray segments are resiliently supported by a rubber spring rod 36 which is counter supported on the throughgoing, fixedly held carrier beam (counter support 35). Further, for each feed tray segment 7a an abutment element 37 is provided which limits the excursion of the feed tray elements 7a in the direction A, B. The feed tray assembly is an integral, one-piece component composed of a throughgoing securing region 7 1 extending over the width of the machine and of the individual feed tray segments 7a. Each feed tray segment 7a is formed of a feed tray body 7 2 and a narrow connecting region 7 3 which functions as an elastic connection and is structured essentially as a leaf spring. The connecting region 7 3 couples the feed tray body 7 2 with the securing region 7 1 . The securing region 7 1 has a perpendicularly oriented projection 7 4 which extends into a recess 17' of the support element 17 and is immobilized by a securing screw-and-nut assembly 38, 39. The support element 17 with the feed tray segments 7a, on the one hand, and the carrier beam 35, on the other hand, are secured independently from one another on the rigid lateral walls of the machine. The support element 17 together with the feed tray segments 7a and the carrier beam 35 may be adjustable when not in operation so that for different types of fiber material the distance and thus the intake gap between the feed tray segments 7a and the feed roll 6 may be suitably varied. It is, however, in the alternative, also feasible to provide a stationary and immovable securement of the support element 17 and the carrier beam 35.
Turning to FIG. 4, with the feed tray body 7 2 of each feed tray segment 7a an inductive path sensor 39 is associated which is composed of a plunger armature and a plunger coil and is connected to an electronic control and regulating device as shown in FIG. 19. In this manner, upon oscillation of the feed tray segments 7a electric pulses are generated which represent the tray segment excursions in response to thickness variations of the fibers which pass through the intake gap between the feed tray assembly 7 and the feed roll 6. The feed tray segments 7a are provided with a wear-resistance layer, for example, a high grade steel plating 41 on the side which contacts the fiber material.
According to FIG. 5, each feed tray segment 7a has a connecting part 7 3 which couples the tray segment body 7 2 with the support element 17 to which it is secured at 7 1 . The resiliency of each feed tray segment 7a is ensured by the weakening notches 7 5 provided in the connecting part 7 3 in the vicinity of its securement 7 1 .
Turning to FIG. 6, the required clamping forces for holding the fiber material against the opening forces of the after-connected opening roll 8 are applied--in addition to the inherent resiliency of the feed tray segments--by a respective further spring 28 (such as a compression spring) which is positioned between a rearward face 7" of each feed tray segment 7a and the carrier beam 35. The inherent resiliency of the feed tray elements is obtained by the particular configuration of their elastic material such as steel, aluminum, synthetic material or wood.
In FIG. 7, the pressing spring 28 of each feed tray element 7a is positioned as close as possible to the maximum pressure location in the pressing zone for the fiber material. The graph of FIG. 7a shows the pressure/displacement (P/S) curve.
As shown in FIG. 8, in the feed tray body 7 2 of the individual feed tray elements 7a and in the carrier beam 35 respective recesses 7 6 and 35 1 are provided for receiving the respective ends of elastic elements, such as springs 28.
According to FIG. 9, the elastomer spring, for example, the rubber spring rod 36 which extends over the width of the machine, is glued to the feed tray segments 7a.
In FIG. 10, as an elastic element a composite component is used which is formed of a rubber spring 36 bonded to a metal element 40 which, in turn, is attached to the carrier beam 35.
As shown in FIG. 11, the elastic element may be a hollow rubber bar 36.
FIG. 12 shows how all the feed tray elements 7a are biased by a round rubber bar which extends over the entire width of the machine.
FIG. 13 illustrates that the entire feed tray assembly 7 is made as a one-piece, integral component. The yielding properties of each feed tray segment 7a are ensured by parallel spaced cuts which have a width f and between which the feed tray segments are defined.
Turning to FIGS. 14a and 20a, the thickness (depth) of the feed tray body 7 2 is designated at d and may be, for example, 40-80 mm whereas its height is designated at e and may be, for example 200-300 mm. The overall dimension in the working direction is designated at c. A T-shaped recess 7 7 is provided in the feed tray body 7 2 to receive the end of an abutment member 46 held on the carrier beam 35. The abutment member 46 limits the excursions of the feed tray segments 7a in both directions. The projection 7 4 has a throughgoing bore to receive the screw-and-nut assembly 38, 39 as also shown in FIG. 3. The width of each feed tray segment 7a is designated at a in FIG. 14b and may amount to approximately 80-120 mm. The feed tray segments 7a are made of an elastic material whose surface oriented toward the fiber material is provided with a respective high grade steel plating 41.
Turning to FIG. 15, after plating, for example, with a high grade steel plate 41, a weakening notch 7 5 is provided to increase the resiliency of the feed tray segments 7a relative to their common support element 17. The steel plating is divided over the entire working width of the feed tray assembly 7 by the separating cuts and the plating sheet material is removed from the zones 7 1 and 7 3 .
In accordance with FIG. 16, in addition to the steel plating 41 for the individual segments 7a, over the entire width of the machine a sheet metal cover member 42 is installed which extends from the securing zone at the support element 17 down to the upper part of the segment body 7 2 of the feed tray segments 7a. The cover plate 42 may also serve as an abutment.
As shown in FIG. 17, a holding element 44 is provided which counter supports the spring rod 36 and which is movable by two links 43a and 43b connected with the machine frame. A spring 45 urges the holding element against the spring rod 36.
According to FIG. 18, on the carrier beam 35 an abutting element 46 is provided which is connected with a projection 47 (such as a screw or the like) mounted on the tray segment body 7 2 in such a manner that the excursion in the direction B is limited. In this manner, a contacting between the tray segment body 7 2 and the feed roll 6 is prevented. The length of the projection 47 may be adjusted and thus the gap width may be set.
Turning to FIG. 19, the inductive path sensors 39 are connected with an electronic control and regulating device 49, for example, a microcomputer to which there are also connected an rpm-regulated motor 50 for the feed roll 6. The setting signals emitted by the control and regulating device 49 may be also used for a plurality of setting members distributed along the width b of the machine, for example, for setting the depth of a chute.
According to FIG. 20b, the elongated support element 17 is, at its frontal face, mounted on the inner walls of the stationary machine walls 48a and 48b. The inner machine width b is approximately 1,000-1,400 mm.
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.
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A feeding device for advancing fiber material includes a driven feed roll; a support element immovably held during operation and extending spaced from and generally parallel to the feed roll; and a feed tray assembly composed of a plurality of side-by-side positioned feed tray segments. Each feed tray segment is of a resilient material and has a first portion (end portion) immovably affixed to the support element and a movable, second portion having a surface oriented toward the feed roll and cooperating therewith for advancing the fiber material passing through a nip defined between the feed roll and each feed tray segment. The second portion of each feed tray segment is displaceable toward and away from the feed roll.
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[0001] This application is a division of and claims priority to U.S. patent application Ser. No. 13/485,776 filed May 31, 2012, and titled “METHODS AND APPARATUS FOR REDUCING CELLULAR TELEPHONE RADIATION EXPOSURE” (Attorney Docket No. BMD013), which claims priority to U.S. Provisional Patent Application No. 61/491,890, filed May 31, 2011 and titled “METHODS AND APPARATUS FOR REDUCING CELLULAR TELEPHONE RADIATION EXPOSURE” (Attorney Docket No. BMD013/L), and U.S. Provisional Patent Application No. 61/492,349, filed Jun. 1, 2011, and titled “METHODS AND APPARATUS FOR REDUCING CELLULAR TELEPHONE RADIATION EXPOSURE” (Attorney Docket No. BMD013-02/L). Each of the above applications is hereby incorporated herein by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to cellular telephones, and more particularly to reducing exposure to radiation from cellular telephones.
BACKGROUND
[0003] Cellular telephones are very convenient and have become important to modern society. Cellular telephones allow people to be in constant contact, access voice and data virtually anywhere, etc. However, some recent studies have shown a potential increased risk of cancer associated with use of cellular telephones. Accordingly, a need exists for methods and apparatus for reducing cellular telephone radiation exposure.
SUMMARY
[0004] In some aspects, a system is provided that includes (1) a low radiation handset; and (2) a cellular unit separate from the low radiation handset and adapted to communicate with the low radiation handset and to allow the low radiation handset to communicate over a cellular network.
[0005] In some aspects, a cellular telephone includes (1) a user interface portion having a communications circuit; and (2) a cellular portion having a first communications circuit adapted to communicate with the communications circuit of the user interface portion and a second communications circuit adapted to communicate with a cellular network. The cellular portion is removably coupled to the user interface portion so as to allow a user of the cellular telephone to communicate over a cellular network by using the user interface portion while the cellular portion is separated from the user interface portion.
[0006] In some aspects, a method is provided that includes providing a cellular telephone having (1) a user interface portion having a communications circuit; and (2) a cellular portion having a first communications circuit adapted to communicate with the communications circuit of the user interface portion and a second communications circuit adapted to communicate with a cellular network. The method includes detaching the cellular portion from the user interface portion; and using the user interface portion to place a cellular telephone call when the cellular portion is detached from the user interface portion.
[0007] Numerous other aspects are provided, as are various methods, apparatus and computer program products for carrying out these and other aspects of the invention. Each computer program product may be carried by a medium readable by a computer (e.g., a carrier wave signal, a floppy disc, a hard drive, a random access memory, etc.).
[0008] Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 is a side schematic diagram of a cellular telephone provided in accordance with the present invention;
[0010] FIG. 2A is a side schematic diagram of the cellular telephone of FIG. 1 with a cellular portion removed in accordance with the present invention;
[0011] FIG. 2B is a side schematic diagram of the cellular telephone of FIG. 1 with a cellular portion being plugged into an outlet in accordance with the present invention; and
[0012] FIG. 3 is a schematic diagram of a cellular unit provided in accordance with the present invention.
DETAILED DESCRIPTION
[0013] Cellular telephones emit electromagnetic radiation when communicating over a cellular network. The amount of radiation emitted varies, with larger amounts of radiation typically being emitted when a cellular telephone is indoors, further away from a cellular tower or otherwise located in a poor signal strength area in relation to a cellular network.
[0014] In one or more embodiments of the invention, methods and apparatus are provided for reducing exposure of a person to radiation from a cellular telephone while still allowing the user to communicate via the cellular network. For example, in some embodiments, a low radiation (LR) handset is provided that is similar to a regular cellular telephone in layout and/or function. “Low radiation” refers to a radiation level below that typically used by a cellular telephone communicating with a cellular tower and/or cellular network (particularly when the cellular telephone is indoors or far from a cellular tower). For example, in some embodiments, low radiation may be less than about 0.2 SAR, in other embodiments less than about 0.1 SAR and in other embodiments less than about 0.05 SAR (1.6 Watts/kilogram standard). Larger or smaller radiation levels may be used.
[0015] In one or more embodiments, the LR handset communicates through a cellular telephone a short distance from the LR handset (e.g., in the same room, building, office, apartment or house). For example, a user may use the LR handset to place calls, receive calls, send text messages, surf the WEB or perform any traditional cellular telephone activities by tethering to, piggy-backing off of or otherwise employing the cellular telephone to communicate with a cellular network. The LR handset only requires enough signal strength to communicate with the cellular telephone (or a portion of the cellular telephone as described below) which may be placed a short distance from the user (e.g., in the same room, office, house, across a yard or sports field, etc.). In this manner, the user is not directly exposed to the cellular telephone's more powerful radiation because the cellular telephone is not in direct contact with the user (e.g., in the user's hand, next to the user's head, against the user's waist, in the user's pocket, etc.). Rather, the cellular telephone may be remote from the user. In some embodiments, multiple LR handsets may communicate across a cellular network via a single cellular telephone.
[0016] As stated, in some embodiments, the LR handset may be similar (or nearly identical) to a traditional cellular telephone in look, size, functionality, or the like.
[0017] In some embodiments, a transmitter/receiver unit capable of communicating over a cellular network may be provided in place of a cellular telephone. An LR handset may then communicate through a cellular network via the transmitter/receiver unit (e.g., in place of or in addition to a cellular telephone). The transmitter/receiver unit may be located a distance from the user so that the user is not directly exposed to the transmitter/receiver unit's more powerful radiation. For example, the transmitter/receiver unit may be located outside of a user's home, office, car, in the same room, office, house, etc.
[0018] Use of a separate “cellular” unit (e.g., a portion of a cellular telephone, a transmitter/receiver unit, etc.) to communicate via the cellular network allows the LR handset to use less radiation, be smaller, lighter and cheaper, and to consume significantly less battery power. For example, the separate cellular unit may be plugged into an electrical outlet or otherwise receive line voltage. Furthermore, the cellular unit may employ larger or otherwise more effective antennas or even higher transmission power levels to improve cellular coverage. In some embodiments, the LR handset may employ WiFi, Bluetooth or a similar communications protocol to communicate with the separate “cellular” unit (e.g., allowing for easy use of multiple LR handsets, creating a cellular “hot spot”, or the like).
[0019] In some embodiments, a cellular telephone may be provided in which a portion of the cellular telephone that communicates with a cellular network such as the antenna and/or transmitter/receiver circuitry, referred to herein as “cellular portion”, is detachable yet still operable with the remainder of the cellular telephone (e.g., an LR handset or “user interface portion” when the cellular portion is removed). For example, the cellular portion may be detached from the cellular telephone and placed a short distance from the remainder of the cellular telephone such as at the edge of a desk, in the same room, in a different room, across an office, or the like, and the remaining LR handset (and/or user interface portion) may communicate with the cellular portion to access a cellular network.
[0020] In some embodiments, the cellular portion may be attached to a separate power supply (e.g., another battery, line voltage, etc.) than is used by the LR handset. The cellular portion may communicate with the LR handset wirelessly or via one or more wires. For example, the LR handset may communicate with the cellular portion via Bluetooth, WiFi, or the like.
[0021] FIG. 1 illustrates an exemplary cellular telephone 100 provided in accordance with an embodiment of the present invention. The cellular telephone 100 includes a display 102 which in some embodiments may also serve as a keyboard. In other embodiments, a separate keyboard may be provided. A first battery 104 is provided for powering a first local transceiver circuit and/or antenna 106 and a second battery 108 is provided for powering a second local transceiver circuit and/or antenna 110 , as well as a cellular transceiver circuit and/or antenna 112 . As will be described further below, the first and second local transceiver circuits and/or antennas 106 and 110 , or similar communications circuitry, may function as “low radiation level” communications circuitry emitting lower levels of radiation than the portion of the cellular telephone 100 that communicates with a cellular network (e.g., cellular transceiver circuit/antenna 112 or another higher radiation level communications circuit). Additional circuitry (not shown) may be provided such as microprocessors, microcontrollers, memory, input/output circuitry, display driver circuitry, and/or any other similar circuitry suitable for use with a cellular telephone. Fewer or more batteries and/or other power sources may be employed.
[0022] With reference to FIG. 2A , when desired, the second battery 108 , second local transceiver circuit/antenna 110 , and the cellular transceiver circuit/antenna 112 may be removed (e.g., as a “cellular” unit 114 ) from the cellular telephone 100 and remain in communication with the cellular telephone 100 (e.g., via communication between the first and second local transceiver circuits 106 and 110 or similar circuitry). The remainder of the cellular telephone 100 without the cellular unit 114 may function as a user interface portion 115 . The first and second local transceiver circuits 106 and 110 may communicate via a wireless or wired channel. In some embodiments, a wireless protocol such as Bluetooth, WiFi, or any other suitable protocol may be used for communication between the first and second local transceiver circuits 106 and 110 . The cellular transceiver circuit/antenna 112 (or similar circuitry) may remain in communication with a cellular network, such as via a cell tower 116 in FIG. 2A .
[0023] In some embodiments, the power level used for communication between the local transceiver circuit/antennas 106 and 110 may be significantly less than the power level used for communication between the cellular transceiver circuit/antenna 112 and the cell tower 116 . For example, in some embodiments, the power levels used by cellular transceiver circuit/antenna 112 may be up to 1.6 SAR or higher, whereas the power levels used by the local transceiver circuit/antenna 106 and/or 110 may be less than about 0.2 SAR, in other embodiments less than about 0.1 SAR and in other embodiments less than about 0.05 SAR (1.6 Watts/kilogram standard). Other power levels may be used for any of these circuits. In some embodiments, different communication frequencies also may be used.
[0024] In operation, a user of the cellular telephone 100 may detach the cellular unit 114 from the cellular telephone 100 and place the cellular unit 114 a distance from the user so as to limit exposure of the user to radiation from the cellular transceiver circuit/antenna 112 during use of the cellular telephone 100 . In some embodiments, the cellular unit 114 may be connected to a supplemental power source such as an additional battery or line voltage. In this manner, battery life of the cellular telephone 100 may be extended and exposure of the user to radiation from the cellular transceiver circuit/antenna 112 may be reduced. For example, FIG. 2B illustrates a cellular unit 114 detached from user interface portion 115 . The cellular portion 114 may include a foldable plug for connecting cellular unit 114 to an electrical outlet 118 . In some embodiments, the cellular unit 114 may be attached to the user, such as at the user's waist if desired.
[0025] In some embodiments, the signal strength output by the cellular unit 114 may be increased when the cellular unit 114 is detached from the remainder of the cellular telephone 100 . For instance, a switch, electrical contact or the like (not shown) may be provided that senses when the cellular unit 114 and interface portion 115 are not in contact. Thereafter the maximum power level of the electromagnetic radiation emitted from cellular unit 114 may be increased.
[0026] FIG. 3 illustrates an alternative embodiment of the present invention in which a cellular telephone 300 may automatically enter a low radiation mode to reduce exposure of a user 301 to radiation. With reference to FIG. 3 , a cellular unit 302 is provided that may communicate with both the cellular telephone 300 via a low radiation (LR) communication device 304 and a cellular network (not separately shown) via a cell tower 306 . In some embodiments, the LR communication device 304 may be a wireless router that employs WiFi or a similar wireless protocol, although other LR communication devices may be used (e.g., a communication device that uses Bluetooth or another wireless protocol). For example, the cellular unit 302 may plug into the LR communication device 304 via a CAT5 or similar cable, or communicate wirelessly with the LR communication device 304 .
[0027] The cellular telephone 300 may include a mobile application or be otherwise configured to detect the presence of the cellular unit 302 when the cellular telephone 300 is within range of the LR communication device 304 . In such instances, the cellular telephone 300 may enter a low radiation mode, such as an airplane mode, and stop communicating directly with the cell tower 306 . For instance, the circuitry used to communicate with cellular towers may be disabled within the cellular telephone 300 while low radiation emitting communications circuitry such as WiFi, Bluetooth, or similar circuitry may remain active. The cellular telephone 300 may communicate with the cell tower 306 indirectly by communicating with the cellular unit 302 through the LR communication device 304 . The higher radiation levels used to communicate with the cell tower 306 thereby may be remote from the user 301 and radiation exposure of the user 301 may be reduced relative to communications that occur directly between the cellular telephone 300 and the cell tower 306 (e.g., when the cell phone 300 is in contact or proximate the user 301 as shown).
[0028] In some embodiments, cellular units 302 may communicate directly with the cellular telephone 300 and cell tower 306 without use of the LR communication device 304 (e.g., via WiFi or a similar protocol). Cellular units 302 may be located wherever the user communicates on his/her cell phone often (e.g., at home, at an apartment, at an office, in a car, etc.). In each case, the cellular unit 302 may be located a distance from the user to reduce close range exposure of the user to radiation associated with communicating over a cellular network. In some embodiments, the cellular telephone 300 may automatically detect the presence of a cellular unit 302 and seamlessly switch to a low radiation mode (e.g., reducing radiation exposure of the user and extending battery life of the cellular telephone). In some embodiments, multiple cellular telephones may communicate over a cellular network via a cellular unit 302 . For example, a cellular network may allow a multi-line or multi-party license or access to a cellular network via a cellular unit 302 .
[0029] In one or more embodiments, the cellular unit 302 may employ a higher power level, larger antenna and/or better location for communicating with the cell tower 306 than would be possible for the cellular telephone 300 , improving cellular reception.
[0030] Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.
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In some aspects, a cellular telephone includes (1) a user interface portion having a communications circuit; and (2) a cellular portion having a first communications circuit adapted to communicate with the communications circuit of the user interface portion and a second communications circuit adapted to communicate with a cellular network. The cellular portion is removably coupled to the user interface portion so as to allow a user of the cellular telephone to communicate over a cellular network by using the user interface portion while the cellular portion is separated from the user interface portion. Numerous other aspects are provided.
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BACKGROUND OF THE INVENTION
This invention relates to a method for forming a thin film by means of a sputtering technique and more particularly to a method suitably used to form an alloy thin film, compound thin film or multi-layer thin film. This invention also relates to a sputtering device for forming such a thin film.
When forming an alloy thin film, compound thin film or laminated or multi-layer thin film by means of a sputtering technique, sputtering is generally carried out using an alloy target, compound target or laminated target. However, in the case where the alloy thin film is formed, some combinations of components of the alloy do not provide an alloy target of a uniform composition so that sputtering using this alloy target in turn does not provide an alloy thin film of a uniform composition. Further, in the case of the laminated target, some combinations of components do not permit a laminated structure to be formed or laminated structures made of some combinations of components can not be machined into a target. For example, it is very difficult to form a laminated structure target consisting of ceramics and metals.
There has been proposed in Japanese Patent Unexamined Publication No. 60-13,068 a method for forming a composite thin film such as a compound thin film, laminated thin film, etc. using plural targets in such a manner that sputtering is always carried out from one of the plural target with the other remaining targets interrupted by a shutter. This method, however, is not suitable to provide an alloy thin film of a uniform composition since vaporized particles produced from the respective targets are laminarly deposited on a substrate or wafer. The resultant film has a disadvantage that it provides a weak adhesion between the adjacent layers of the laminated film.
SUMMARY OF THE INVENTION
One object of this invention is to solve the problems as mentioned above and to provide a thin film forming method which can provide a composite thin film, e.g. an alloy thin film, compound thin film, laminated thin film and the like of any composition and enhance adhesion among the particles or between the adjacent layers.
Another object of this invention is to provide a sputtering device suitably used for performing the above thin film forming method.
A feature of the thin forming method according to one aspect of this invention resides in that plural targets of different materials are sputtered by freely switching electric powers to be supplied to them, and vaporized particles produced through the sputtering are ionized to be deposited on a substrate. By ionizing the vaporized particles produced through the sputtering, adhesion among the deposited particles is enhanced. In this case, by switching the electric powers to be supplied to the respective targets in such a manner that the electric power is supplied to only one target at any time, plasma discharge interference among the targets can be prevented. Further, by accelerating the ionized particles, diffusion of atoms or molecules among the deposited particles is facilitated, thereby further enhancing the adhesion thereamong.
Even when a thin laminated film is to be formed by shortening the switching time of the electric powers to be supplied to plural targets, if the ionized particles are accelerated, by diffusing atoms or molecules among the layers of the film, an alloy thin film is formed.
As a sputter power source, the power source having the function of controlling a pulse discharge time or peak electric power in each target is preferably used. Each target is provided with a switching element which can be individually turned on or off, and the switching element sequentially changes at high speeds the pulse discharge time or peak electric power of the corresponding target in accordance with the composition of the alloyed or composite film.
A predetermined composite thin film can be formed by ionizing the particles produced through the sputtering using thermoelectrons or high frequency, and accelerating the ionized particles using an accelerating voltage with its peak voltage or pulse width changed in synchronizm with the switching frequency of the targets so as to individually control the kinetic energy of the particles evaporated from each target and ionized in accordance with each of the components contained in the film. A composite film comprised of a metal and insulator can be formed by supplying a D.C. pulse current to a metallic target while supplying a high frequency current to an insulator target. The high frequency current can conduct through the insulator. Repetition of alternate sputtering of the metallic target and insulator with a shortened sputtering time therefor can provide a thin compound film. Repetition of alternate sputtering of the metallic target and insulator target with a lengthened sputtering time therefor can provide a multi-layer thin film with alternately stacked metallic layers and insulator layers. In the case where a composite thin film comprised of different kinds of insulator is to be formed, the compound thin film or multi-layer thin film can be formed by supplying a high frequency current to each target and adjusting the sputtering time for each target.
The above mentioned thin film forming method according to this invention can be performed using such a sputtering device as mentioned below. This sputtering device comprises at least two kinds of target, a sputtering power source having means for freely changing the pulse width and peak value of the pulse electric power supplied to each target, and means for ionizing the particles produced from the respective targets through the sputtering.
This sputtering device is preferably provided with an ion accelerating means. By providing this ion accelerating means with a power source which is capable of freely changing the pulse width and peak value of the ion accelerating voltage in synchronism with the switching frequency of the targets, an optimum ion accelerating condition in accordance with the kinds of particles produced through the sputtering and the composition of the thin film to be formed can be determined.
As a means for ionizing the particles produced from the target through the sputtering, thermoelectrons of high frequency can be used. The particles produced through the sputtering bear no charge so that they provide a weak adhesion to each other, but the ionized particles provide a strong adhesion to each other.
As a method for ionizing the vaporized particles and depositing them on a substrate so as to form a thin film, an ion-plating technique is known. This technique vaporizes a vaporizing metal by means of resistive heating, electron beams, etc. and deposites a part of metallic vapor with ⊕ ions on the substrate. This technique, however, has a disadvantage that when the alloy is fused and vaporized for forming a composite thin film, the thin film thus formed cannot provide a desired composition because of different vapor pressures of the components of the alloy.
On the other hand, this invention carries out sputtering using plural targets of different materials so that the alloy thin film formed in accordance with this invention can provide a desired composition regardless of different vapor pressures of the components.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a composite film forming device in accordance with this invention; and
FIGS. 2, 3 and 4 are waveform charts of a sputtering voltage and ion accelerating voltage in this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically shows a composite thin film forming device in accordance with this invention. In the figure, 1 denotes a D.C. pulse power source for supplying pulse electric powers to targets 4 and 5. 6 and 7 denote switching elements for alternately switching the D.C. pulses and supplying the power to target 4 or 5, e.g., switching transistors. The particles 3 produced from the targets alternately switched are ionized by an ionizing device comprising a filament heating power source 13, filament 16 and thermoelectron accelerating power source 19.
This device is provided with a D.C. pulse power source 17 for depositing the ionized particles on a substrate 2 with an accelerating voltage with its peak value or pulse width freely changed in synchronizm with the switching frequency of the targets; a differential exhausting device 20 for adjusting the ambient pressures of a sputtering chamber 21 and ion accelerating chamber 22; and a control device 18 for synchronizing the switching of switching transistors 6 and 7, and the ion accelerating condition with the sputtering condition.
D.C. pulse power source 1 sets the peak values and pulse widths of the powers supplied to targets 4 and 5.
The sputtering device according to this invention is also provided with magnets 14 at targets 4 and 5 for increasing the respective sputtering rates therefor.
The ionizing device accelerates the thermoelectrons from filament 16 towards a plate 15 and ionizes the particles produced from the targets into ionized particles 3.
FIG. 2 schematically illustrates the waveforms of the sputtering voltage and ion accelerating voltage in the sputtering device shown in FIG. 1. In the case of forming a composite thin film using targets 4 and 5, particles having a required composition are produced by changing a conducting ratio t 1 /(t 1 +t 2 ). The particle thus produced are neutral particles and can be regarded as providing a compound composition on the average, but in reality, they alternately emanate from targets 4 and 5 when observed microscopically. These neutral vaporized particles are hit by electrons produced from filament 16 so as to be ionized.
In accordance with this invention, the kinetic energies of the ionized particles from targets 4 and 5 can be individually changed as required in such a way that the ⊕ ionized particles are controlled in their ion energy by varying the ion accelerating voltage in synchronizm with the switching frequency of targets 4 and 5. Thus, the adhesion, density and alloying of the resultant composite thin film can be improved. For example, when the ionized particles from targets 4 and 5 are alternately deposited on substrate 2 with the shortened sputtering times of the targets, they are seldom deposited laminarly but likely to be diffused since they have kinetic energies through the ionization and acceleration, thereby facilitating the alloying and combination.
Moreover, in accordance with this invention, by controlling the ion accelerating voltages matched with the masses of the respective ionized particles, a compound composition consisting of an alloy and a laminated compound can be obtained, and accordingly, this invention can also be applied to the research of new functional materials or the like.
Since thin films formed through sputtering or vacuum evaporation technique are often amorphous, they are generally subjected to heat treatment after the evaporation so as to be crystalized and hence stabilized. On the other hand, in this invention, ionized particles are accelerated and deposited on the substrate through their bombardment so that their crystal nuclei are likely to be produced and grown, and the alloying can be also advanced at the same time with the crystallization. The crystallization can be controlled by varying the peak value and pulse width of each of the ion accelerating voltages in synchronizm with the switching frequency of the targets so that the resultant composite thin film can provide a desired property. The adhesion and density of the thin film can also be adjusted in the same manner.
An example when this invention has been applied to the fabrication of a Cr-Ni thin film resistor body will be explained below. Targets of chromium (Cr) and nickel (Ni) are prepared. The peak voltage to be supplied to the respective targets is fixed at 500 V. The average voltages are set at 200 V for the Ni target and at 300 V for the Cr target. The switching frequency is set at 60 Hz; the ion accelerating voltages are set at 1 KV for the Ni ions and at 1.5 KV for the CR ions; the sputtering chamber ambient pressure (argon: Ar) is set at 2×10 -3 Torr and the ion accelerating chamber is set at 8×10 -5 Torr. For comparison, there has been practiced a method in which the Cr and Ni targets prepared are alternately sputtered and deposited on a substrate without being ionized, and a method in which a Cr-Ni alloy is heated for its vaporization and the ionized vapor is deposited on a substrate.
As a result of X-ray diffraction analysis and electron-microscope observation of the Cr-Ni composite films formed, it has been found that the thin film of this invention is a completely alloyed and good thin film which is crystallized, dense and free from any pinholes. This film indicated a 1.6 times larger strength than the films in the prior arts in a peel test of films. On the other hand, the films in accordance with the prior arts, formed for comparison, were deposited in a mesh-like shape and poorly densified, and showed an amorphous property since their alloying was incomplete.
In the above explanation, a method for forming a composite film consisting of one metal and another metal has been described, but a composite film consisting of a metal and insulator can be formed by applying a high frequency voltage to the insulator target, as shown in FIG. 3. Further, a composite film consisting of one insulator and another insulator can be formed by applying a high frequency voltage to both insulator targets, as shown in FIG. 4.
As apparent from the above explanation, in accordance with this invention, a composite thin film, e.g. an alloyed thin film, compound thin film, etc., having any composition can be formed. Further, in accordance with this invention, the crystallization can be controlled without heat treatment to the film deposited on a substrate and also the density and adhesion in the film can be improved so that an ideal composite thin film can be formed.
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A method for forming a thin film wherein plural targets of different materials are alternately sputtered througth the switching of the electric powers supplied thereto, the particles produced from the sputtering are ionized and thereafter deposited on a substrate. This method provides an alloy thin film, compound thin film or multi-layer thin film of any composition and enhances adhesion among the particles. A sputtering device for practicing this method is also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the continuous casting of steel and more particularly to the use of a sealed tundish in the continuous casting of steel, and to an improved tundish seal for such use.
2. Description of the Prior Art
The adverse effects of atmospheric oxygen and nitrogen contacting molten steel in a pouring or casting operation are well known, and numerous patents have issued on apparatus and devices for shielding the molten metal from the atmosphere to prevent oxidation and nitrogen pickup during such operations. In a continuous casting operation, it is conventional for the molten steel to be transported from the convertor to the caster in a ladle where it is supported on a turret for movement into position above a tundish having its pouring outlet, or outlets, directly above the open top of the caster mold, or molds.
Molten steel in the ladle is covered with a layer of slag, and is dispensed through an outlet in the ladle bottom under control of a slide valve. A refractory shroud tube attached to the slide valve extends through an opening in the tundish cover to a point beneath the surface of the pool of metal in the tundish during casting. From the tundish, the metal flows through one or more bottom outlets under control of stopper valves, again through a refractory tube or tubes extending below the level of the molten metal in the caster mold. Thus, the molten steel is shielded from the atmosphere in its flow path from the ladle into the tundish, and from the tundish into the mold. In the tundish, however, and particularly during the initial filling of a newly lined tundish, contact with the atmosphere can result in substantial nitrogen pickup and oxidation of the molten steel. Indeed, in casting of high purity prime priced steels suitable for forming exposed automobile body components or for tinplate, it has in the past been generally necessary to downgrade or even scrap up to 5 or 6 slabs, each weighing up to 30,000 pounds or more, cut from the leading end of a continuous strand cast using a newly lined tundish.
Attempts have been made to purge atmosphere containing free oxygen and nitrogen from the interior of a tundish by injecting an inert gas into the tundish, one such continuous casting system being illustrated in U.S. Pat. No. 3,558,256; however, because of the size of the tundish used in modern casters, and the number and size of openings required in the conventional tundish cover, such attempts to purge the tundish generally have required an excessive amount of inert gas and have not been entirely successful. Further, in many tundishes in use today, particularly for multi-strand casters, the cover itself is formed in a number of sections having openings therethrough as for the pouring of steel from the ladle or to accommodate the insertion and manipulation of the stopper rods employed to control the flow rate from the tundish.
Dimensional tolerances in commercial continuous casting machines are such that openings in the tundish cover are necessarily substantially larger than the shroud tube or stopper rod to be inserted therethrough. Unavoidable spacing or cracks between adjacent tundish cover sections and between the cover sections and the top of the tundish, and the opening in the sidewall for a dumping spout provide additional openings to the interior of the tundish. Attempts to purge such prior art covered tundishes have therefore been only marginally effective.
U.S. Pat. No. 5,368,208 discloses a further attempt to shield air from molten metal in a continuous casting facility and illustrates, in the drawings, a large opening into the tundish in the form of a pouring or dumping spout. No attempt is made to seal the top of the tundish beneath the cover.
U.S. Pat. No. 3,459,346 discloses a molten metal pouring spout employed between a ladle and a tundish and illustrates the pouring spout projecting downwardly through the cover on the tundish. FIG. 1 illustrates the spout extending through the opening in the tundish cover with substantial clearance as is considered necessary in such operations.
It is, accordingly, a primary object of the present invention is to provide an improved seal between the open top of the tundish and the rigid tundish cover to substantially eliminate the ingress of atmospheric air into the tundish by maintaining a positive purging gas pressure in the tundish during the casting operation.
Another object is to provide such a tundish seal which enables efficient and economical purging and pressurizing of the tundish space with an inert gas to effectively eliminate free oxygen and nitrogen from the tundish prior to and during the casting operation.
Another object is to provide a lightweight, economical and efficient, disposable seal which may be quickly and easily positioned over the open top of the tundish before placing the cover thereon, with the seal material extending over the openings provided in the tundish cover and being penetrable in the areas of such openings by the ladle shroud tube and tundish flow control stopper rods.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages are achieved in accordance with the present invention by providing a temperature resistant tundish seal in the form of a plurality of generally rectangular, dimensionally stable and self-supporting sealing boards formed from a refractory ceramic fiber. The boards are placed in side-by-side overlapping configuration to completely cover the open top of a newly lined tundish to be used in a continuous casting operation. The conventional tundish cover consisting of a plurality of cast refractory slabs is then placed onto the tundish on top of the sealing boards. The boards are rabbeted along their opposed side edges to provide a shiplap joint between adjacent boards to thereby form an effective seal beneath the tundish cover. The cover slabs compress the refractory fiber boards between their bottom surface and the upwardly directed peripheral edge of the refractory sidewalls of the tundish to provide a gasket-type seal.
The sealing boards not only provide an effective seal for the top of the tundish but also serve as an effective thermal insulation limiting the transfer of heat from the interior of the tundish to the cover both during preheating of a newly lined tundish and during casting. Prior to or after installation of the tundish cover, the sealing boards may be scored in the area of the shroud tube opening and the stopper rod opening(s) to enable these elements to readily penetrate the boards without producing an excessive opening at the beginning of the casting operation.
A newly lined, sealed tundish is preheated in the conventional manner. During preheating, the sealing boards act as a thermal blanket reducing the heat absorption by the tundish cover and thereby accelerating the heating of the body of the tundish. By substantially reducing the effective opening area of the closed tundish, the inflow of diluting cooling air is reduced and preheating efficiency is correspondingly increased.
Prior to commencing casting, and during preheating of the tundish tubes from the floor, an inert gas, preferably argon, is discharged into the tundish to purge the interior of free oxygen and nitrogen containing air. Oxygen levels, typically around 15% during this operation, is reduced to approximately 1% by use of the improved tundish seal. During purging, the inert gas forms a positive pressure which prevents ambient air from being drawn through unsealed openings such as the dumping spout. Upon commencing the pouring of molten steel into the tundish at the start of a casting run, visible emissions (smoke) escaping through any unsealed openings provides a positive indication of the tundish pressurization.
DESCRIPTION OF THE DRAWINGS
The foregoing and other features and advantages of the invention will be apparent from the detailed description contained hereinbelow, taken in conjunction with the drawings, in which:
FIG. 1 is a schematic view, in section, of a continuous caster employing an improved seal tundish in accordance with the present invention;
FIG. 2 is a top plan view of the tundish, taken along 2--2 of FIG. 1;
FIG. 3 is an enlarged, fragmentary sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is an isometric view schematically illustrating a sealing board being scored to facilitate penetration thereof by a ladle shroud tube or the like; and
FIG. 5 is a graphic illustration of the nitrogen content of steel produced on a continuous caster in accordance with the prior art and by use of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, a tundish 10 sealed in accordance with the present invention, is illustrated schematically as being used in a continuous steel casting operation with molten steel 12 being supplied from a ladle 14 through a conventional slide valve 16 and shroud tube 18 into the sealed inner chamber 20 of the tundish. It is understood that the ladle 14 is supported on the conventional carrousel, not shown, for movement into position above the tundish 10 and then lowered to project the shroud tube 18 into the tundish interior prior to opening of valve 16.
The tundish 10 is of conventional construction, consisting of a rigid outer metal vessel 22 having a poured or cast refractory lining 24. The tundish shown is intended for use in a dual strand caster capable of simultaneously casting two strands of steel. Thus, the tundish 10 has a pair of outlets 26, 28 in its bottom wall 30, with the outlets being located near the opposed end walls of the tundish. A pair of pouring tubes 32 supported in the end walls 30 and projecting downwardly therefrom provides a sealed flow passage for molten steel from the interior of the tundish from outlets 26, 28 into caster molds 34, 36, respectively. Flow through the outlets 26, 28 into the pouring tubes 32 may be controlled by suitable means such as stopper rods 38, 40 manipulated by conventional means, not shown, from outside the tundish.
The tundish 10 includes a removable top wall, or cover, in the form of a plurality of generally rectangular cast refractory plates or slabs 42, 44, 46 supported on the upwardly directed top edge 47 of the refractory lining 24 of sidewalls 48. In addition, a pair of interior skimmer, or splash walls 50, are provided within the tundish, with a plurality of openings or orifices 52 provided in the walls 50 to permit molten steel flowing from the shroud tube 18 into the central portion of the tundish 20 to flow laterally to the end portions for discharge through the outlets 26, 28.
Cover plates 42 and 46 are provided with central openings 54, 56, to permit the insertion of slag removal rods or gas lances, for receiving the stopper rods 38, 40, respectively, and cover plate 44 has a central opening 58 for receiving the shroud tube 18. As seen in FIG. 1, the openings 54, 56 and 58 are substantially larger than the diameter of the elements projecting therethrough during the casting operation to avoid interference with the insertion and/or manipulation of the respective elements as required during casting.
It is pointed out that, while the tundish 10 is shown with two outlets, a single strand caster will only have a single pouring outlet. Also, while a cover in the form of three slabs is illustrated, any number of slab elements may be utilized as is conventional in the continuous casting art.
Referring now to FIGS. 2 and 3, in accordance with the present invention, a newly relined tundish is prepared for use in the continuous casting operation by initialling providing a seal indicated generally at 60 in FIG. 3 for the open top of the tundish. The seal is in the form of a plurality of generally rectangular, dimensionally stable and self-supporting flat refractory ceramic fiber boards 62 placed in side-by-side, overlapping configuration on the upwardly directed top edge surface 47 of the tundish sidewall 48. Also as seen in FIG. 3, the tundish comprises a rigid metal outer shell 22 which projects upwardly above the top edge surface 47 and cooperates therewith to provide a recessed ledge positioning and retaining the ceramic boards 62 and the cast refractory top panels 42, 44 and 46 in position on the open top of the tundish.
As best seen in FIGS. 3 and 4, the refractory ceramic fiber sealing boards 62 are provided with a rabbet 64 along their longitudinal side edges to provide an overlap, or shiplap-type joint between adjacent boards to form a more effective seal between adjacent boards. The boards 62 preferably are formed from a vitreous alumina silicate fiber consisting of 43% to 95% alumina fiber and about 5% to about 56% silica, with about 5% binder. The boards preferably have a density of about 0.18 to about 0.20 grams per cubic centimeter. Boards formed of this material having a thickness within the range of about 13 to about 38 millimeters have been found to be satisfactory.
Once the sealing boards are in place on top of the tundish, the heavy refractory cover panels 42, 44, 46 are placed on the tundish and compress the overlapping portion of the respective boards onto the upwardly directed surface 47 to firmly clamp and retain the sealing boards against movement. As seen in FIG. 3, the sealing boards provide a continuous seal not only between the cover panels and the surface 47, but also to extend over and seal the joints between adjacent cover panels and any openings in the cover panels. It is understood, of course, that the sealing boards do not provide a seal for the conventional tundish pouring spout, and during the tundish preheat as well as during the casting operations, other openings or unsealed areas may provide fluid communication between the interior of the tundish and the surrounding ambient atmosphere. During preheating, the ceramic fiber sealing boards provide an effective thermal insulation for the cover panels and substantially reduce the escape of heat through openings in and around the cover panels, enabling more heat to be absorbed by the bottom and sidewalls of the tundish and a consequent substantial savings in time and energy for preheating.
As illustrated in FIG. 4, the sealing boards 62 which will be penetrated by the stopper rods 38, 40 and by the shroud tube 18 are preferably scored with a suitable blade 68 as indicated schematically by the lines 70. This scoring operation may be accomplished either prior to or after the cover panels are placed on the tundish and preferably the scoring only serves to weaken the panel so that, as the panel is penetrated by the stopper rods or shroud tube, the area surrounding the respective elements will be deflected inwardly but not broken free of the board to thereby minimize the open area in the seal caused by the insertion of these or other elements.
Prior to commencement of use of the heated tundish in a casting operation, and during preheating of the tundish tube(s) or pour tube(s), argon or other suitable inert gas is admitted, for example through inlet pipes indicated schematically at 72, to purge oxygen-containing atmosphere from the interior of the tundish. During this operation, the oxygen level in the tundish without the use of the sealing boards is typically about 15% but with use of the sealing boards, this oxygen level is quickly reduced to about 1%. This reduction in oxygen is accompanied by a corresponding reduction in free nitrogen, with the result that nitrogen pickup in steel cast at the beginning of a run with a newly lined tundish is greatly reduced, and the steel quality is correspondingly increased.
FIG. 5 graphically illustrates the reduction in nitrogen pickup in steel by use of the sealed tundish according to the present invention. This illustration compares the nitrogen content of steel cast on an unsealed tundish in accordance with conventional practice with that using a sealed tundish, with tests in both instances taken at about 20% into the first ladle cast on a new tundish. Comparisons are shown both on an average basis and utilizing a standard deviation computation. These tests have shown that the nitrogen, which is considered a negative factor for most high grade steels, is consistently reduced from about 8 parts per million to about 3 parts per million at this early stage in a cast using a new tundish.
From a quality aspect, use of a sealed tundish has allowed an upgrading of steel from the initial slab cast on a continuous caster utilizing a new tundish. For example, for high grade steel such as utilized by the automotive industry or for tinplate, use of the sealed tundish according to the present invention enables an upgrading of the first slab cast on each strand from "limited warranty" to "prime unexposed" and, with limited scarfing of the slab, from "no tinplate" application to regular tinplate application. The second slabs can be upgraded from "prime exposed" with scarfing of the slab to "prime exposed" without scarfing, and from tinplate application with scarfing of the slab to tinplate without scarfing. The third and fourth slabs on a tundish may be upgraded from draw-redraw and drawn-and-iron tinplate applications with scarfing of the slabs to these same applications without scarfing. It is thus apparent that the upgrading of 4 to 5 slabs on each strand of a two strand caster, with the consequent increase in market value of these heavy slabs, produces a substantial increase in revenue to the steel producer. In addition, the ceramics fiber sealing boards act as an insulation and enables an increase in the tundish temperature on the order of 200° F. This has the additional benefit of reducing the temperature loss, particularly at the start of use of a new tundish which permits use of less superheat in the liquid steel and/or an increased casting rate at steady state conditions.
While the preferred embodiment of the invention has been disclosed and described in detail, it should be apparent that the invention is not specifically limited thereto, but rather that it is intended to include all embodiments of the invention which would be apparent to one skilled in the art and which come within the spirit and scope of the invention.
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A tundish used in a continuous steel casting operation is sealed to permit effective purging of the tundish to eliminate free oxygen and nitrogen by providing a plurality of generally rectangular planar sealing boards of refractory fiber material having sufficient density to be self-supporting and placing the boards in side-by-side relation on the open top of the tundish prior to installation of the refractory cover whereby the sealing boards form a gasket between the cover and tundish top wall, and form a continuous panel underlying the cover. The refractory fiber material may be penetrated by the ladle shroud tube and/or the tundish stopper rod(s).
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BACKGROUND OF THE INVENTION
[0001] The invention relates to method and apparatus for converting a computer-dependent data format (that is, computer-specific data format) when data is communicated among a plurality of computers. More particularly, the invention relates to a method of converting a program language-dependent data format (that is, program language-specific data format) which is used for communication among distributed objects on a plurality of computers for performing a distributed computing and is used in each computer into a stream data format which is used for communication among the computers. The invention also relates to method and apparatus for converting a stream data format which is used in communication among the computers into a program language-specific data format which is used in each computer.
[0002] Generally, when calling from a certain program to another program, a transmission and a reception of data are performed on the same computer by using an interface which depends on a specific operating system and a specific program language. On the other hand, in a distributed computing environment, a plurality of programs (distributed objects) can exist over a plurality of computers and can transmit and receive data. A distributed object which requests a process is called a client object. A distributed object which processes the request from the client object is called a server object. A function for accepting the request from the client object, retrieving a proper server object to process the request, communicating with the computer in which the server object exists, and calling the server object is called an object request broker (ORB). In the case where the client object and the server object communicate among a plurality of computers, the ORB performs a data exchange by using data of a neutral stream format which is not specific to the architecture of a particular computer, a particular operating system, and a particular program language. Therefore, in order to incorporate an ORB, it is necessary to provide a process (marshalling) for converting from a format which is specific to the architecture of particular computer, particular operating system, and particular program language into a neutral data stream and a reverse process (unmarshalling).
SUMMARY OF THE INVENTION
[0003] Generally, the server object residentially or persistently exists on a certain computer and processes requests from many and unspecified client objects a plural number of times. Each time the request from the client object comes, the unmarshalling process occurs. Each time a reply to the request is returned, the marshalling process occurs.
[0004] An example of the unmarshalling process and marshalling process will be described with reference to FIG. 7.
[0005] In FIG. 7, in the unmarshalling process, stream data is divided from an identifier 10 describing a marshalling method written in the head of stream data 8 and an IDL (Interface Definition Language) 12 describing a structure of the stream data and is converted into the data which is specific to a particular program language while discriminating attributes of each of the divided data elements from the IDL. The IDL 12 includes, for example, information indicating such that the first data of the stream data is an integer type and the next data is a character type. In the marshalling process, first, a marshalling method is determined from the architecture of the computer which executes the marshalling process and the version of the ORB and the identifier 10 of the marshalling method is stored in the header of the stream. Subsequently, the attributes of the data are discriminated with respect to each of the program language-specific data and the program language-specific data is converted into the stream data. In those processes, it is necessary to understand the meaning of each of the inputted data in order to convert each inputted data. In the case where data of a complicated format such as data of a user definition type or the like is exchanged between the client and the server, a load of computing resources (CPU, main memory or other resources) which are required for the marshalling and unmarshalling is large.
[0006] It is an object of the invention to provide high-speed marshalling and unmarshalling processing methods and apparatus in the case where a transmission and a reception of data between a client and a server occur a plural number of times.
[0007] To accomplish the above object, according to one aspect of the invention, there is provided an apparatus for converting a data format which is specific to a particular program language on a particular computer into stream data which is not specific to, i.e., is common to particular computers, comprising: a caching part or component for storing a correspondence between a program language-specific data format and stream data; a marshalling part or component for retrieving whether all or a part of the data of the program language-specific format has been stored in the cache or not, for performing a conversion by using the data on the cache when the data exists on the cache, and for converting the data of the program language-specific format into the stream data without using the cache when the data does not exist on the cache; and a cache registering part or component for registering a result into the cache at the time of the conversion from the data of the program language-specific format into the stream data or the conversion from the stream data into the data of the program language-specific format.
[0008] In such a construction, when the data is transmitted, the marshalling part retrieves or discriminates whether the received data exists on the cache or not, converts the data at a high speed by referring to the cache when the data exists, and converts the data at a low speed by the foregoing method or another known method without using the cache when the data does not exist. When the data is converted by the method which does not use the cache, the conversion result is registered into the cache by using the cache registering part.
[0009] According to another aspect of the invention, there is provided an apparatus for converting stream data which is not specific to or is common to particular computers into the data of a format which is specific to a particular program language on a particular computer, comprising: a caching part or component for storing a correspondence between stream data and data of a program language-specific format; an unmarshalling part or component for discriminating whether all or a part of the stream data has been stored in the cache or not, for performing a conversion by using the data on the cache when the stream data exists on the cache, and for converting the stream data into the data of the program language-specific format without using the cache when the data does not exist on the cache; and a cache registering part or component for registering a result into the cache at the time of the conversion from the stream data into the data of the program language-specific format or the conversion from the data of the program language-specific format into the stream data. In such a construction, when the data is received, the unmarshalling part discriminates whether the received data exists on the cache or not, converts the data at a high speed by using the cache when the data exists, and converts the data at a low speed by the foregoing method or another known method without using the cache when the data does not exist on the cache. When the data is converted without using the cache, the conversion result is registered into the cache by using the cache registering part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a diagram showing a constructional example of a distributed computing environment to which the invention is applied;
[0011] [0011]FIG. 2 is a diagram showing an ORB (object request broker) according to an embodiment of the invention;
[0012] [0012]FIG. 3 is a diagram showing a flow of data at the time of marshalling and a structure of a cache in the embodiment of FIG. 2;
[0013] [0013]FIG. 4 is a flowchart showing a flow of processes at the time of marshalling in the embodiment of FIG. 2;
[0014] [0014]FIG. 5 is a diagram showing a flow of data at the time of unmarshalling and a structure of a cache in the embodiment of FIG. 2;
[0015] [0015]FIG. 6 is a flowchart showing a flow of processes at the time of unmarshalling in the embodiment of FIG. 2; and
[0016] [0016]FIG. 7 is a diagram that is useful for explaining an example of a marshalling process which does not use a cache and an unmarshalling process.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] An embodiment of the invention will now be described hereinbelow with reference to the drawings. Similar component elements in the diagrams are designated by the same reference numerals.
[0018] [0018]FIG. 1 is a diagram showing a construction of a distributed computing environment according to an embodiment of the invention.
[0019] In the diagram, a client program 602 on a small computer 1 requests a processing work to a server program 601 on a large computer 2 existing at a remote place and having a plenty of computing resources via a network 3 . By receiving this request, the server program 601 processes the processing job or task and returns a result of the processing to the client program 602 . FIG. 2 is a diagram showing a flow of data in such a construction.
[0020] In FIG. 2, a client program 111 has therein: program data 113 and 122 which is specific to a computer and a described program language; an ORB 141 which is used by the client program; and the like. A server program 112 has therein: program data 117 and 118 which is specific to the computer and the described program language; an ORB 142 which is used by the server program; and the like.
[0021] How to exchange the data between the client program 111 and server program 112 in FIG. 2 will now be described with respect to a flow of data. In the client program 111 , to transmit the program data 113 of a data format specific to the computer on which the client program operates and the described program to the server program 112 , a marshalling part 114 of the ORB 141 converts from the program data 113 to request communication data 115 which is not specific to particular computers or program languages. In this instance, if all or a part of the program data 113 exists in a cache 131 of the client program by referring to the cache 131 , the data is converted into the request communication data 115 by using the cache data. After completion of the conversion, the data 115 is transmitted to the server program 112 .
[0022] In the server program 112 , an unmarshalling part 116 of the ORB 142 converts the received request communication data 115 into the program data 117 of a format which is specific to the computer on which the server program operates or to the described program language. In this instance, if all or a part of the request communication data 115 exists in a cache 132 of the server program by referring to the cache 132 , the data is converted into the program data 117 by using the cache data.
[0023] After the server program processed the request from the client, to return the program data 118 as a processing result to the client program, the data is converted into response communication data 120 by a marshalling part 119 of the ORB 142 . At this time, if all or a part of the program data 118 exists in the cache 132 of the server program with reference to the cache 132 , the data is converted into the response communication data 120 by using the cache data. The response communication data 120 is transmitted to the client program.
[0024] In the client program 111 , the received data is converted into the program data 122 of the client program language-specific format by an unmarshalling part 121 of the ORB 141 . At this time, if all or a part of the response communication data 120 exists in a cache 131 of the client program with reference to the cache 131 , the data is converted into the program data 122 by using the cache data. In this manner, the data transmission and reception can be performed between the distributed client and server programs at a high speed.
[0025] An embodiment of processes in the marshalling part 114 and 119 in FIG. 2 will now be described with reference to FIG. 3. Although the marshalling part 114 in FIG. 2 is used as an example in the description, a similar embodiment is also possible in the marshalling part 119 .
[0026] [0026]FIG. 3 is a diagram showing a structure of the cache at the time of marshalling and a flow of data of the marshalling process. First, the structure of the cache will be explained. A pair of contents of the program data and contents of the communication data corresponding thereto have been stored in the cache every type of program data (in the example of FIG. 3, a pair of a program data cache 211 and a communication data cache 212 for an “aTable” struct). When the program data is based on the user definition type, every element (user definition type or basic type) of the user definition type data, an offset from the header of the communication data corresponding thereto is stored in the cache. In the example of FIG. 3, a system having the cache corresponding to every user definition type and basic type is shown. Although the case where the correspondence of the pair of communication data and program data is stored on the cache is shown in the diagram, a correspondence of a plurality of pairs of communication data and program data can be also provided on the cache. The “basic type” indicates data such as numeral, a single character, a character string, or the like. The “user definition type” indicates a set of basic type data and other user definition type data, which is generally complicated data. For example, a plurality of attributes of a particular employee such as name, age and employee identification number, can be represented by single user definition type data.
[0027] A flow of data of the marshalling process and a flow of control will now be described with reference to FIGS. 3 and 4. In the marshalling part, first, the program data 113 to be transmitted and the program data 211 on the cache corresponding to its type are compared (S 311 ) and whether their contents are matched with each other or not is discriminated (S 312 ). Even in the case where the data to be checked is the user definition type such as struct, union, or the like, it is not decomposed to respective elemental types constituting the user definition type, but the user definition type is compared, as is, on the memory. If it is determined that the contents match as a comparison result, the next data is checked. When there is a difference or unmatch between the contents, the communication data 212 on the cache corresponding to the program data which was identical or matched until the difference is detected is copied into the request communication data 115 (S 313 ). Whether the program data with the difference or unmatch is the basic type or the user definition type is discriminated (S 314 ). In case of the basic type, since it does not take a long time for the converting process, a process to convert the program data into the communication data is performed (S 315 ). In case of the user definition type, the data is long in many cases and there is a possibility that the user definition type data has been registered in another cache. Therefore, the marshalling process is recursively called (S 316 ). (In the example of FIG. 3, the marshalling process is recursively called by using the struct “aStr” in which the output program data 113 does not coincide or match as an argument.) A conversion result in step S 315 or S 316 is registered into the cache (S 317 ). The processes in steps S 311 to S 317 are executed to all of the data. When there is no data to be processed (S 310 ), the communication data remaining on the cache at this time point is copied (S 318 ).
[0028] An embodiment of the processes in the unmarshalling parts 116 and 121 in FIG. 2 will now be described. Although the unmarshalling part 116 in FIG. 2 will be explained as an example, a similar embodiment is also possible even in the unmarshalling part 121 .
[0029] [0029]FIG. 5 is a diagram showing a structure of the cache at the time of unmarshalling and a flow of data in the unmarshalling process. First, the structure of the cache will be explained. A pair of contents of the program data and contents of the communication data corresponding thereto have been stored in the cache every type of program data (in the example of FIG. 5, a pair of a communication data cache 411 for an “aTable” struct and a program data cache 412 ). When the program data is the user definition type, every element (user definition type or basic type) of the program data of the user definition type, an offset from the header of the communication data corresponding thereto is stored in the cache. By using this correlation, to which element in the program data an arbitrary offset of the communication data corresponds will be understood. In the example of FIG. 5, a system having the cache every user definition type and basic type is shown. Although the case where the correspondence of the pair of communication data and program data has been stored on the cache every type is shown in the diagram, a correspondence of a plurality of pairs of communication data and program data can be also provided on the cache.
[0030] A flow of data in the unmarshalling process and a flow of control will now be described with reference to FIGS. 5 and 6. In the unmarshalling part, the received request communication data 115 and the communication data 411 on the cache are compared on an octet unit basis as a unit of the communication data (S 511 ). Whether they have the same value or not is discriminated (S 512 ). Thus, if they have the same value, the next octet is checked. If they do not have the same value and there is a difference or unmatch, the program data 412 on the cache corresponding to the communication data which was identical or showed match until the difference or unmatch is detected is copied into the output program data 117 (S 513 ). Whether the program data having the difference or unmatch is the basic type or user definition type is discriminated by looking at the program data or IDL 12 (S 514 ). In case of the basic type, since it does not take a long time for the converting process, a process to convert the communication data into the program data is performed (S 515 ). In case of the user definition type, the data is long in many cases and there is a possibility that the data of the user definition type has been registered in another cache (not shown). Therefore, the unmarshalling process is recursively called (S 516 ). A conversion result in step S 515 or S 516 is registered into the cache (S 517 ). The processes in steps S 511 to S 517 are executed to all of the octets of the communication data. When there is no data to be processed (S 510 ), the program data remaining on the cache at this time point is copied (S 518 ).
[0031] Generally, the server object residentially or persistently exists on a certain computer and processes similar requests from many and unspecified client objects a plural number of times. Hitherto, to independently execute the marshalling and unmarshalling processes in response to those similar processing requests of a plural number of times, in the case where a complicated data format is exchanged between the client and the server, a load of computing resources (CPU, main memory) which are required for the marshalling and unmarshalling is large. In the embodiment, the converting process which was once performed is stored into the cache and it is used from the next time, so that the computing resources which are required for the marshalling and unmarshalling can be reduced.
[0032] The procedures shown in FIGS. 4 and 6 and other procedures described herein can be stored into an ROM or a disk in each of the small computer 1 and large computer 2 or into another memory means.
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In an object request broker (ORB) for processing requests or responses among distributed objects, a method and an apparatus for realizing a high processing speed of a process to convert from data (communication data) which is used in communication among the ORBs and is not specific to particular computers into a data format (program data) which is specific to a program language. A correspondence between the communication data which was transmitted and received by the ORB and the conversion into the program data corresponding thereto is stored in a cache which can be called at a high speed. When a receiving process of the same communication data cached at the second and subsequent times or a transmitting process of the program data occurs, the cached conversion result is used.
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